[PATCH v3 08/11] tee: add Qualcomm TEE driver

Amirreza Zarrabi posted 11 patches 8 months, 3 weeks ago
There is a newer version of this series
[PATCH v3 08/11] tee: add Qualcomm TEE driver
Posted by Amirreza Zarrabi 8 months, 3 weeks ago
Introduce qcomtee_object, which represents an object in both QTEE and
the kernel. QTEE clients can invoke an instance of qcomtee_object to
access QTEE services. If this invocation produces a new object in QTEE,
an instance of qcomtee_object will be returned.

Similarly, QTEE can request services from the kernel by issuing a callback
request, which invokes an instance of qcomtee_object in the kernel.
Any subsystem that exposes a service to QTEE should allocate and initialize
an instance of qcomtee_object with a dispatcher callback that is called
when the object is invoked.

Implement initial support for exporting qcomtee_object to userspace
and QTEE, enabling the invocation of objects hosted in QTEE and userspace
through the TEE subsystem.

Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
---
 drivers/tee/Kconfig                    |   1 +
 drivers/tee/Makefile                   |   1 +
 drivers/tee/qcomtee/Kconfig            |  10 +
 drivers/tee/qcomtee/Makefile           |   9 +
 drivers/tee/qcomtee/async.c            | 160 +++++++
 drivers/tee/qcomtee/call.c             | 753 +++++++++++++++++++++++++++++++
 drivers/tee/qcomtee/core.c             | 801 +++++++++++++++++++++++++++++++++
 drivers/tee/qcomtee/qcom_scm.c         |  38 ++
 drivers/tee/qcomtee/qcomtee_msg.h      | 239 ++++++++++
 drivers/tee/qcomtee/qcomtee_private.h  | 222 +++++++++
 drivers/tee/qcomtee/release.c          |  48 ++
 drivers/tee/qcomtee/shm.c              | 149 ++++++
 drivers/tee/qcomtee/user_obj.c         | 710 +++++++++++++++++++++++++++++
 include/linux/firmware/qcom/qcom_tee.h | 302 +++++++++++++
 include/uapi/linux/tee.h               |   1 +
 15 files changed, 3444 insertions(+)

diff --git a/drivers/tee/Kconfig b/drivers/tee/Kconfig
index 61b507c18780..3a995d7f0d74 100644
--- a/drivers/tee/Kconfig
+++ b/drivers/tee/Kconfig
@@ -16,5 +16,6 @@ if TEE
 source "drivers/tee/optee/Kconfig"
 source "drivers/tee/amdtee/Kconfig"
 source "drivers/tee/tstee/Kconfig"
+source "drivers/tee/qcomtee/Kconfig"
 
 endif
diff --git a/drivers/tee/Makefile b/drivers/tee/Makefile
index 5488cba30bd2..74e987f8f7ea 100644
--- a/drivers/tee/Makefile
+++ b/drivers/tee/Makefile
@@ -6,3 +6,4 @@ tee-objs += tee_shm_pool.o
 obj-$(CONFIG_OPTEE) += optee/
 obj-$(CONFIG_AMDTEE) += amdtee/
 obj-$(CONFIG_ARM_TSTEE) += tstee/
+obj-$(CONFIG_QCOMTEE) += qcomtee/
diff --git a/drivers/tee/qcomtee/Kconfig b/drivers/tee/qcomtee/Kconfig
new file mode 100644
index 000000000000..d180a6d07d33
--- /dev/null
+++ b/drivers/tee/qcomtee/Kconfig
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Qualcomm Trusted Execution Environment Configuration
+config QCOMTEE
+	tristate "Qualcomm TEE Support"
+	select QCOM_SCM
+	help
+	  This option enables the Qualcomm Trusted Execution Environment (QTEE)
+	  driver. It provides an API to access services offered by QTEE and any
+	  loaded Trusted Applications (TAs), as well as exporting kernel
+	  services to QTEE.
diff --git a/drivers/tee/qcomtee/Makefile b/drivers/tee/qcomtee/Makefile
new file mode 100644
index 000000000000..1b14b943e5f5
--- /dev/null
+++ b/drivers/tee/qcomtee/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_QCOMTEE) += qcomtee.o
+qcomtee-objs += async.o
+qcomtee-objs += call.o
+qcomtee-objs += core.o
+qcomtee-objs += qcom_scm.o
+qcomtee-objs += release.o
+qcomtee-objs += shm.o
+qcomtee-objs += user_obj.o
diff --git a/drivers/tee/qcomtee/async.c b/drivers/tee/qcomtee/async.c
new file mode 100644
index 000000000000..4c880c3441a2
--- /dev/null
+++ b/drivers/tee/qcomtee/async.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include "qcomtee_private.h"
+#include "qcomtee_msg.h"
+
+#define QCOMTEE_ASYNC_VERSION_1_0 0x00010000U /* Maj: 0x0001, Min: 0x0000. */
+#define QCOMTEE_ASYNC_VERSION_1_1 0x00010001U /* Maj: 0x0001, Min: 0x0001. */
+#define QCOMTEE_ASYNC_VERSION_1_2 0x00010002U /* Maj: 0x0001, Min: 0x0002. */
+#define QCOMTEE_ASYNC_VERSION QCOMTEE_ASYNC_VERSION_1_2 /* Current Version. */
+
+#define QCOMTEE_ASYNC_VERSION_MAJOR(n) upper_16_bits(n)
+#define QCOMTEE_ASYNC_VERSION_MINOR(n) lower_16_bits(n)
+
+/**
+ * struct qcomtee_async_msg_hdr - Asynchronous message header format.
+ * @version: current async protocol version of the remote endpoint.
+ * @op: async operation.
+ *
+ * @version specifies the endpoint's (QTEE or driver) supported async protocol.
+ * For example, if QTEE sets @version to %QCOMTEE_ASYNC_VERSION_1_1, QTEE
+ * handles operations supported in %QCOMTEE_ASYNC_VERSION_1_1 or
+ * %QCOMTEE_ASYNC_VERSION_1_0. @op determines the message format.
+ */
+struct qcomtee_async_msg_hdr {
+	u32 version;
+	u32 op;
+};
+
+/* Size of an empty async message. */
+#define QCOMTEE_ASYNC_MSG_ZERO sizeof(struct qcomtee_async_msg_hdr)
+
+/**
+ * struct qcomtee_async_release_msg - Release asynchronous message.
+ * @hdr: message header as &struct qcomtee_async_msg_hdr.
+ * @counts: number of objects in @object_ids.
+ * @object_ids: array of object IDs that should be released.
+ *
+ * Available in Maj = 0x0001, Min >= 0x0000.
+ */
+struct qcomtee_async_release_msg {
+	struct qcomtee_async_msg_hdr hdr;
+	u32 counts;
+	u32 object_ids[] __counted_by(counts);
+};
+
+/**
+ * qcomtee_get_async_buffer() - Get the start of the asynchronous message.
+ * @oic: context used for the current invocation.
+ * @async_buffer: return buffer to extract from or fill in async messages.
+ *
+ * If @oic is used for direct object invocation, the whole outbound buffer
+ * is available for the async message. If @oic is used for a callback request,
+ * the tail of the outbound buffer (after the callback request message) is
+ * available for the async message.
+ *
+ * The start of the async buffer is aligned, see qcomtee_msg_offset_align().
+ */
+static void qcomtee_get_async_buffer(struct qcomtee_object_invoke_ctx *oic,
+				     struct qcomtee_buffer *async_buffer)
+{
+	struct qcomtee_msg_callback *msg;
+	unsigned int offset;
+	int i;
+
+	if (!(oic->flags & QCOMTEE_OIC_FLAG_BUSY)) {
+		/* The outbound buffer is empty. Using the whole buffer. */
+		offset = 0;
+	} else {
+		msg = (struct qcomtee_msg_callback *)oic->out_msg.addr;
+
+		/* Start offset in a message for buffer arguments. */
+		offset = qcomtee_msg_buffer_args(struct qcomtee_msg_callback,
+						 qcomtee_msg_args(msg));
+
+		/* Add size of IB arguments. */
+		qcomtee_msg_for_each_input_buffer(i, msg)
+			offset += qcomtee_msg_offset_align(msg->args[i].b.size);
+
+		/* Add size of OB arguments. */
+		qcomtee_msg_for_each_output_buffer(i, msg)
+			offset += qcomtee_msg_offset_align(msg->args[i].b.size);
+	}
+
+	async_buffer->addr = oic->out_msg.addr + offset;
+	async_buffer->size = oic->out_msg.size - offset;
+}
+
+/**
+ * async_release() - Process QTEE async release requests.
+ * @oic: context used for the current invocation.
+ * @msg: async message for object release.
+ * @size: size of the async buffer available.
+ *
+ * Return: Size of the outbound buffer used when processing @msg.
+ */
+static size_t async_release(struct qcomtee_object_invoke_ctx *oic,
+			    struct qcomtee_async_msg_hdr *async_msg,
+			    size_t size)
+{
+	struct qcomtee_async_release_msg *msg;
+	struct qcomtee_object *object;
+	int i;
+
+	msg = (struct qcomtee_async_release_msg *)async_msg;
+
+	for (i = 0; i < msg->counts; i++) {
+		object = qcomtee_idx_erase(msg->object_ids[i]);
+		qcomtee_object_put(object);
+	}
+
+	return struct_size(msg, object_ids, msg->counts);
+}
+
+/**
+ * qcomtee_fetch_async_reqs() - Fetch and process asynchronous messages.
+ * @oic: context used for the current invocation.
+ *
+ * Calls handlers to process the requested operations in the async message.
+ * Currently, only supports async release requests.
+ */
+void qcomtee_fetch_async_reqs(struct qcomtee_object_invoke_ctx *oic)
+{
+	struct qcomtee_async_msg_hdr *async_msg;
+	struct qcomtee_buffer async_buffer;
+	size_t consumed, used = 0;
+
+	qcomtee_get_async_buffer(oic, &async_buffer);
+
+	while (async_buffer.size - used > QCOMTEE_ASYNC_MSG_ZERO) {
+		async_msg = (struct qcomtee_async_msg_hdr *)(async_buffer.addr +
+							     used);
+
+		if (QCOMTEE_ASYNC_VERSION_MAJOR(async_msg->version) !=
+		    QCOMTEE_ASYNC_VERSION_MAJOR(QCOMTEE_ASYNC_VERSION))
+			goto out;
+
+		switch (async_msg->op) {
+		case QCOMTEE_MSG_OBJECT_OP_RELEASE:
+			consumed = async_release(oic, async_msg,
+						 async_buffer.size - used);
+			break;
+		default:
+			goto out;
+		}
+
+		/* Supported operation but unable to parse the message. */
+		if (!consumed)
+			goto out;
+
+		/* Next async message. */
+		used += qcomtee_msg_offset_align(consumed);
+	}
+
+out:
+	/* Reset the async buffer so async requests do not loop to QTEE. */
+	memzero_explicit(async_buffer.addr, async_buffer.size);
+}
diff --git a/drivers/tee/qcomtee/call.c b/drivers/tee/qcomtee/call.c
new file mode 100644
index 000000000000..f7f5c2c0bebb
--- /dev/null
+++ b/drivers/tee/qcomtee/call.c
@@ -0,0 +1,753 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/tee.h>
+#include <linux/platform_device.h>
+
+#include "qcomtee_private.h"
+
+static int find_qtee_object(struct qcomtee_object **object, unsigned long id,
+			    struct qcomtee_context_data *ctxdata)
+{
+	int err = 0;
+
+	guard(rcu)();
+	/* Object release is RCU protected. */
+	*object = idr_find(&ctxdata->qtee_objects_idr, id);
+	if (!qcomtee_object_get(*object))
+		err = -EINVAL;
+
+	return err;
+}
+
+static void del_qtee_object(unsigned long id,
+			    struct qcomtee_context_data *ctxdata)
+{
+	struct qcomtee_object *object;
+
+	scoped_guard(spinlock, &ctxdata->qtee_lock)
+		object = idr_remove(&ctxdata->qtee_objects_idr, id);
+
+	qcomtee_object_put(object);
+}
+
+/**
+ * qcomtee_context_add_qtee_object() - Add a QTEE object to the context.
+ * @param: TEE parameter representing @object.
+ * @object: QTEE object.
+ * @ctx: context to add the object.
+ *
+ * It assumes @object is %QCOMTEE_OBJECT_TYPE_TEE and the caller has already
+ * issued qcomtee_object_get() for @object.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_context_add_qtee_object(struct tee_param *param,
+				    struct qcomtee_object *object,
+				    struct tee_context *ctx)
+{
+	int ret;
+	struct qcomtee_context_data *ctxdata = ctx->data;
+
+	guard(spinlock)(&ctxdata->qtee_lock);
+	ret = idr_alloc(&ctxdata->qtee_objects_idr, object, 0, 0, GFP_KERNEL);
+	if (ret < 0)
+		return ret;
+
+	param->u.objref.id = ret;
+	/* QTEE Object: QCOMTEE_OBJREF_FLAG_TEE set. */
+	param->u.objref.flags = QCOMTEE_OBJREF_FLAG_TEE;
+
+	return 0;
+}
+
+/* Retrieve the QTEE object added with qcomtee_context_add_qtee_object(). */
+int qcomtee_context_find_qtee_object(struct qcomtee_object **object,
+				     struct tee_param *param,
+				     struct tee_context *ctx)
+{
+	struct qcomtee_context_data *ctxdata = ctx->data;
+
+	/* 'qtee_objects_idr' stores QTEE objects only. */
+	if (!(param->u.objref.flags & QCOMTEE_OBJREF_FLAG_TEE))
+		return -EINVAL;
+
+	return find_qtee_object(object, param->u.objref.id, ctxdata);
+}
+
+/**
+ * qcomtee_context_del_qtee_object() - Delete a QTEE object from the context.
+ * @param: TEE parameter representing @object.
+ * @ctx: context for deleting the object.
+ *
+ * The @param has been initialized by qcomtee_context_add_qtee_object().
+ */
+void qcomtee_context_del_qtee_object(struct tee_param *param,
+				     struct tee_context *ctx)
+{
+	struct qcomtee_context_data *ctxdata = ctx->data;
+
+	/* 'qtee_objects_idr' stores QTEE objects only. */
+	if (param->u.objref.flags & QCOMTEE_OBJREF_FLAG_TEE)
+		del_qtee_object(param->u.objref.id, ctxdata);
+}
+
+/**
+ * qcomtee_objref_to_arg() - Convert OBJREF parameter to QTEE argument.
+ * @arg: QTEE argument.
+ * @param: TEE parameter.
+ * @ctx: context in which the conversion should happen.
+ *
+ * It assumes @param is an OBJREF.
+ * It does not set @arg.type; the caller should initialize it to a correct
+ * &enum qcomtee_arg_type value. It gets the object's refcount in @arg;
+ * the caller should manage to put it afterward.
+ *
+ * For objects that are not in QTEE (i.e. !(param->u.objref.flags &
+ * QCOMTEE_OBJREF_FLAG_TEE)), it also calls qcomtee_object_get() to keep a
+ * temporary copy for the driver as the release of them are asynchronous and
+ * may go away even before returning from the invocation.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_objref_to_arg(struct qcomtee_arg *arg, struct tee_param *param,
+			  struct tee_context *ctx)
+{
+	struct qcomtee_object *object;
+	int err;
+
+	/* param is a NULL object: */
+	if (param->u.objref.id == TEE_OBJREF_NULL) {
+		arg->o = NULL_QCOMTEE_OBJECT;
+
+		return 0;
+	}
+
+	/* param is a callback object: */
+	if (param->u.objref.flags & QCOMTEE_OBJREF_FLAG_USER) {
+		err = qcomtee_user_param_to_object(&object, param, ctx);
+		if (!err)
+			qcomtee_object_get(object);
+	/* param is a QTEE object: */
+	} else if (param->u.objref.flags & QCOMTEE_OBJREF_FLAG_TEE) {
+		err = qcomtee_context_find_qtee_object(&object, param, ctx);
+	} else {
+		err = -EINVAL;
+	}
+
+	arg->o = err ? NULL_QCOMTEE_OBJECT : object;
+
+	return err;
+}
+
+/**
+ * qcomtee_objref_from_arg() - Convert QTEE argument to OBJREF param.
+ * @param: TEE parameter.
+ * @arg: QTEE argument.
+ * @ctx: context in which the conversion should happen.
+ *
+ * It assumes @arg is of %QCOMTEE_ARG_TYPE_IO or %QCOMTEE_ARG_TYPE_OO.
+ * It does not set @param.attr; the caller should initialize it to a
+ * correct type.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_objref_from_arg(struct tee_param *param, struct qcomtee_arg *arg,
+			    struct tee_context *ctx)
+{
+	struct qcomtee_object *object;
+	int err;
+
+	/* param should be of OBJREF. */
+	if (param->attr != TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT &&
+	    param->attr != TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT &&
+	    param->attr != TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INOUT)
+		return -EINVAL;
+
+	object = arg->o;
+
+	switch (typeof_qcomtee_object(object)) {
+	case QCOMTEE_OBJECT_TYPE_NULL:
+		param->u.objref.id = TEE_OBJREF_NULL;
+		err = 0;
+
+		break;
+	case QCOMTEE_OBJECT_TYPE_CB:
+		if (is_qcomtee_user_object(object))
+			err = qcomtee_user_param_from_object(param, object,
+							     ctx);
+		else
+			err = -EINVAL;
+
+		break;
+	case QCOMTEE_OBJECT_TYPE_TEE:
+		err = qcomtee_context_add_qtee_object(param, object, ctx);
+
+		break;
+	case QCOMTEE_OBJECT_TYPE_ROOT:
+	default:
+		return -EINVAL;
+	}
+
+	return err;
+}
+
+/**
+ * qcomtee_params_to_args() - Convert TEE parameters to QTEE arguments.
+ * @u: QTEE arguments.
+ * @params: TEE parameters.
+ * @num_params: number of elements in the parameter array.
+ * @ctx: context in which the conversion should happen.
+ *
+ * It assumes @u has at least @num_params + 1 entries and has been initialized
+ * with %QCOMTEE_ARG_TYPE_INV as &struct qcomtee_arg.type.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+static int qcomtee_params_to_args(struct qcomtee_arg *u,
+				  struct tee_param *params, int num_params,
+				  struct tee_context *ctx)
+{
+	int i;
+
+	for (i = 0; i < num_params; i++) {
+		switch (params[i].attr) {
+		case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT:
+		case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
+			u[i].flags = QCOMTEE_ARG_FLAGS_UADDR;
+			u[i].b.uaddr = params[i].u.ubuf.uaddr;
+			u[i].b.size = params[i].u.ubuf.size;
+
+			if (params[i].attr ==
+			    TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT)
+				u[i].type = QCOMTEE_ARG_TYPE_IB;
+			else /* TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT */
+				u[i].type = QCOMTEE_ARG_TYPE_OB;
+
+			break;
+		case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT:
+			u[i].type = QCOMTEE_ARG_TYPE_IO;
+			if (qcomtee_objref_to_arg(&u[i], &params[i], ctx))
+				goto out_failed;
+
+			break;
+		case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT:
+			u[i].type = QCOMTEE_ARG_TYPE_OO;
+			u[i].o = NULL_QCOMTEE_OBJECT;
+			break;
+		default:
+			goto out_failed;
+		}
+	}
+
+	return 0;
+
+out_failed:
+	/* Undo qcomtee_objref_to_arg(). */
+	for (i--; i >= 0; i--) {
+		if (u[i].type != QCOMTEE_ARG_TYPE_IO)
+			continue;
+
+		qcomtee_user_object_set_notify(u[i].o, false);
+		if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)
+			qcomtee_object_put(u[i].o);
+
+		qcomtee_object_put(u[i].o);
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * qcomtee_params_from_args() - Convert QTEE arguments to TEE parameters.
+ * @params: TEE parameters.
+ * @u: QTEE arguments.
+ * @num_params: number of elements in the parameter array.
+ * @ctx: context in which the conversion should happen.
+ *
+ * @u should have already been initialized by qcomtee_params_to_args().
+ * This also represents the end of a QTEE invocation that started with
+ * qcomtee_params_to_args() by releasing %QCOMTEE_ARG_TYPE_IO objects.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+static int qcomtee_params_from_args(struct tee_param *params,
+				    struct qcomtee_arg *u, int num_params,
+				    struct tee_context *ctx)
+{
+	int i, np;
+
+	qcomtee_arg_for_each(np, u) {
+		if (u[np].type == QCOMTEE_ARG_TYPE_OB) {
+			/* TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT */
+			params[np].u.value.b = u[np].b.size;
+
+		} else if (u[np].type == QCOMTEE_ARG_TYPE_IO) {
+			/* IEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT */
+			qcomtee_object_put(u[np].o);
+
+		} else if (u[np].type == QCOMTEE_ARG_TYPE_OO) {
+			/* TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT */
+			if (qcomtee_objref_from_arg(&params[np], &u[np], ctx))
+				goto out_failed;
+		}
+	}
+
+	return 0;
+
+out_failed:
+	/* Undo qcomtee_objref_from_arg(). */
+	for (i = 0; i < np; i++) {
+		if (params[i].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT)
+			qcomtee_context_del_qtee_object(&params[i], ctx);
+	}
+
+	/* Release any IO and OO objects not processed. */
+	for (; u[i].type; i++) {
+		if (u[i].type == QCOMTEE_ARG_TYPE_OO ||
+		    u[i].type == QCOMTEE_ARG_TYPE_IO)
+			qcomtee_object_put(u[i].o);
+	}
+
+	return -EINVAL;
+}
+
+/* TEE Device Ops. */
+
+static int qcomtee_params_check(struct tee_param *params, int num_params)
+{
+	int io = 0, oo = 0, ib = 0, ob = 0;
+	int i;
+
+	/* QTEE accepts 64 arguments. */
+	if (num_params > QCOMTEE_ARGS_MAX)
+		return -EINVAL;
+
+	/* Supported parameter types. */
+	for (i = 0; i < num_params; i++) {
+		switch (params[i].attr) {
+		case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT:
+			ib++;
+			break;
+		case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
+			ob++;
+			break;
+		case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT:
+			io++;
+			break;
+		case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT:
+			oo++;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	/*  QTEE accepts 16 arguments of each supported types. */
+	if (io > QCOMTEE_ARGS_PER_TYPE || oo > QCOMTEE_ARGS_PER_TYPE ||
+	    ib > QCOMTEE_ARGS_PER_TYPE || ob > QCOMTEE_ARGS_PER_TYPE)
+		return -EINVAL;
+
+	return 0;
+}
+
+/* Check if an operation on ROOT_QCOMTEE_OBJECT from userspace is permitted. */
+static int qcomtee_root_object_check(u32 op, struct tee_param *params,
+				     int num_params)
+{
+	/* Some privileged operations recognized by QTEE. */
+	if (op == QCOMTEE_ROOT_OP_NOTIFY_DOMAIN_CHANGE ||
+	    op == QCOMTEE_ROOT_OP_ADCI_ACCEPT ||
+	    op == QCOMTEE_ROOT_OP_ADCI_SHUTDOWN)
+		return -EINVAL;
+
+	/*
+	 * QCOMTEE_ROOT_OP_REGISTER_WITH_CREDENTIALS is to register with QTEE
+	 * by passing a credential object as input OBJREF. TEE_OBJREF_NULL as a
+	 * credential object represents a privileged client for QTEE and
+	 * is used by the kernel only.
+	 */
+	if (op == QCOMTEE_ROOT_OP_REGISTER_WITH_CREDENTIALS &&
+	    num_params == 2) {
+		if (params[0].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT &&
+		    params[1].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT) {
+			if (params[0].u.objref.id == TEE_OBJREF_NULL)
+				return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * qcomtee_object_invoke() - Invoke a QTEE object.
+ * @ctx: TEE context.
+ * @arg: ioctl arguments.
+ * @params: parameters for the object.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+static int qcomtee_object_invoke(struct tee_context *ctx,
+				 struct tee_ioctl_object_invoke_arg *arg,
+				 struct tee_param *params)
+{
+	struct qcomtee_object_invoke_ctx *oic __free(kfree) = NULL;
+	struct qcomtee_context_data *ctxdata = ctx->data;
+	struct qcomtee_arg *u __free(kfree) = NULL;
+	struct qcomtee_object *object;
+	int i, ret, result;
+
+	if (qcomtee_params_check(params, arg->num_params))
+		return -EINVAL;
+
+	/* First, handle reserved operations: */
+	if (arg->op == QCOMTEE_MSG_OBJECT_OP_RELEASE) {
+		del_qtee_object(arg->object, ctxdata);
+
+		return 0;
+	}
+
+	/* Otherwise, invoke a QTEE object: */
+	oic = qcomtee_object_invoke_ctx_alloc(ctx);
+	if (!oic)
+		return -ENOMEM;
+
+	/* +1 for ending QCOMTEE_ARG_TYPE_INV. */
+	u = kcalloc(arg->num_params + 1, sizeof(*u), GFP_KERNEL);
+	if (!u)
+		return -ENOMEM;
+
+	/* Get an object to invoke. */
+	if (arg->object == TEE_OBJREF_NULL) {
+		/* Use ROOT if TEE_OBJREF_NULL is invoked. */
+		if (qcomtee_root_object_check(arg->op, params, arg->num_params))
+			return -EINVAL;
+
+		object = ROOT_QCOMTEE_OBJECT;
+	} else if (find_qtee_object(&object, arg->object, ctxdata)) {
+		return -EINVAL;
+	}
+
+	ret = qcomtee_params_to_args(u, params, arg->num_params, ctx);
+	if (ret)
+		goto out;
+
+	ret = qcomtee_object_do_invoke(oic, object, arg->op, u, &result);
+	if (ret) {
+		qcomtee_arg_for_each_input_object(i, u) {
+			qcomtee_user_object_set_notify(u[i].o, false);
+			qcomtee_object_put(u[i].o);
+		}
+
+		goto out;
+	}
+
+	if (!result) {
+		/* Assume service is UNAVAIL if unable to process the result. */
+		if (qcomtee_params_from_args(params, u, arg->num_params, ctx))
+			result = QCOMTEE_MSG_ERROR_UNAVAIL;
+	} else {
+		/*
+		 * qcomtee_params_to_args() gets a copy of IO for the driver to
+		 * make sure they do not get released while in the middle of
+		 * invocation. On success (!result), qcomtee_params_from_args()
+		 * puts them.
+		 */
+		qcomtee_arg_for_each_input_object(i, u)
+			qcomtee_object_put(u[i].o);
+	}
+
+	arg->ret = result;
+out:
+	qcomtee_object_put(object);
+
+	return ret;
+}
+
+/**
+ * qcomtee_supp_recv() - Wait for a request for the supplicant.
+ * @ctx: TEE context.
+ * @op: requested operation on the object.
+ * @num_params: number of elements in the parameter array.
+ * @params: parameters for @op.
+ *
+ * The first parameter is a meta %TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT.
+ * On input, it provides a user buffer. This buffer is used for parameters of
+ * type %TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT in qcomtee_cb_params_from_args().
+ * On output, the object ID and request ID are stored in the meta parameter.
+ *
+ * @num_params is updated to the number of parameters that actually exist
+ * in @params on return.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+static int qcomtee_supp_recv(struct tee_context *ctx, u32 *op, u32 *num_params,
+			     struct tee_param *params)
+{
+	struct qcomtee_user_object_request_data data;
+	void __user *uaddr;
+	size_t ubuf_size;
+	int i, ret;
+
+	if (!*num_params)
+		return -EINVAL;
+
+	/* We expect the first parameter to be an INOUT + meta parameter. */
+	if (params->attr !=
+	    (TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT | TEE_IOCTL_PARAM_ATTR_META))
+		return -EINVAL;
+
+	/* Other parameters are none. */
+	for (i = 1; i < *num_params; i++)
+		if (params[i].attr)
+			return -EINVAL;
+
+	if (!IS_ALIGNED(params->u.value.a, 8))
+		return -EINVAL;
+
+	/* User buffer and size from meta parameter. */
+	uaddr = u64_to_user_ptr(params->u.value.a);
+	ubuf_size = params->u.value.b;
+	/* Process TEE parameters. +/-1 to ignore the meta parameter. */
+	ret = qcomtee_user_object_select(ctx, params + 1, *num_params - 1,
+					 uaddr, ubuf_size, &data);
+	if (ret)
+		return ret;
+
+	params->u.value.a = data.object_id;
+	params->u.value.b = data.id;
+	params->u.value.c = 0;
+	*op = data.op;
+	*num_params = data.np + 1;
+
+	return 0;
+}
+
+/**
+ * qcomtee_supp_send() - Submit a response for a request.
+ * @ctx: TEE context.
+ * @errno: return value for the request.
+ * @num_params: number of elements in the parameter array.
+ * @params: returned parameters.
+ *
+ * The first parameter is a meta %TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT.
+ * It specifies the request ID this response belongs to.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+static int qcomtee_supp_send(struct tee_context *ctx, u32 errno, u32 num_params,
+			     struct tee_param *params)
+{
+	if (!num_params)
+		return -EINVAL;
+
+	/* We expect the first parameter to be an OUTPUT + meta parameter. */
+	if (params->attr != (TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT |
+			     TEE_IOCTL_PARAM_ATTR_META))
+		return -EINVAL;
+
+	/* Process TEE parameters. +/-1 to ignore the meta parameter. */
+	return qcomtee_user_object_submit(ctx, params + 1, num_params - 1,
+					  params->u.value.a, errno);
+}
+
+static int qcomtee_open(struct tee_context *ctx)
+{
+	struct qcomtee_context_data *ctxdata __free(kfree) = NULL;
+
+	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
+	if (!ctxdata)
+		return -ENOMEM;
+
+	/*
+	 * In the QTEE driver, the same context is used to refcount resources
+	 * shared by QTEE. For example, teedev_ctx_get() is called for any
+	 * instance of callback objects (see qcomtee_user_param_to_object()).
+	 *
+	 * Maintain a copy of teedev for QTEE as it serves as a direct user of
+	 * this context. The teedev will be released in the context's release().
+	 *
+	 * tee_device_unregister() will remain blocked until all contexts
+	 * are released. This includes contexts owned by the user, which are
+	 * closed by teedev_close_context(), as well as those owned by QTEE
+	 * closed by tee_context_put() in object's release().
+	 */
+	if (!tee_device_get(ctx->teedev))
+		return -EINVAL;
+
+	idr_init(&ctxdata->qtee_objects_idr);
+	spin_lock_init(&ctxdata->qtee_lock);
+	idr_init(&ctxdata->reqs_idr);
+	INIT_LIST_HEAD(&ctxdata->reqs_list);
+	mutex_init(&ctxdata->reqs_lock);
+	init_completion(&ctxdata->req_c);
+
+	ctx->data = no_free_ptr(ctxdata);
+
+	return 0;
+}
+
+/* This is called when the user closes the device. */
+static void qcomtee_close_context(struct tee_context *ctx)
+{
+	struct qcomtee_context_data *ctxdata = ctx->data;
+	struct qcomtee_object *object;
+	int id;
+
+	/* Process QUEUED or PROCESSING requests. */
+	qcomtee_requests_destroy(ctxdata);
+	/* Release QTEE objects. */
+	idr_for_each_entry(&ctxdata->qtee_objects_idr, object, id)
+		qcomtee_object_put(object);
+}
+
+/* This is called when the final reference to the context goes away. */
+static void qcomtee_release(struct tee_context *ctx)
+{
+	struct qcomtee_context_data *ctxdata = ctx->data;
+
+	idr_destroy(&ctxdata->qtee_objects_idr);
+	idr_destroy(&ctxdata->reqs_idr);
+	kfree(ctxdata);
+
+	/* There is nothing shared in this context with QTEE. */
+	tee_device_put(ctx->teedev);
+}
+
+static void qcomtee_get_version(struct tee_device *teedev,
+				struct tee_ioctl_version_data *vers)
+{
+	struct tee_ioctl_version_data v = {
+		.impl_id = TEE_IMPL_ID_QTEE,
+		.gen_caps = TEE_GEN_CAP_OBJREF,
+	};
+
+	*vers = v;
+}
+
+static const struct tee_driver_ops qcomtee_ops = {
+	.get_version = qcomtee_get_version,
+	.open = qcomtee_open,
+	.close_context = qcomtee_close_context,
+	.release = qcomtee_release,
+	.object_invoke_func = qcomtee_object_invoke,
+	.supp_recv = qcomtee_supp_recv,
+	.supp_send = qcomtee_supp_send,
+};
+
+static const struct tee_desc qcomtee_desc = {
+	.name = "qcomtee",
+	.ops = &qcomtee_ops,
+	.owner = THIS_MODULE,
+};
+
+static int qcomtee_probe(struct platform_device *pdev)
+{
+	struct workqueue_struct *async_wq;
+	struct tee_device *teedev;
+	struct tee_shm_pool *pool;
+	struct tee_context *ctx;
+	struct qcomtee *qcomtee;
+	int err;
+
+	qcomtee = kzalloc(sizeof(*qcomtee), GFP_KERNEL);
+	if (!qcomtee)
+		return -ENOMEM;
+
+	pool = qcomtee_shm_pool_alloc();
+	if (IS_ERR(pool)) {
+		err = PTR_ERR(pool);
+
+		goto err_free_qcomtee;
+	}
+
+	teedev = tee_device_alloc(&qcomtee_desc, NULL, pool, qcomtee);
+	if (IS_ERR(teedev)) {
+		err = PTR_ERR(teedev);
+
+		goto err_pool_destroy;
+	}
+
+	qcomtee->teedev = teedev;
+	qcomtee->pool = pool;
+	err = tee_device_register(qcomtee->teedev);
+	if (err)
+		goto err_unreg_teedev;
+
+	platform_set_drvdata(pdev, qcomtee);
+	/* Start async wq. */
+	async_wq = alloc_ordered_workqueue("qcomtee_wq", 0);
+	if (!async_wq)
+		goto err_unreg_teedev;
+
+	qcomtee->wq = async_wq;
+	/* Driver context used for async operations of teedev. */
+	ctx = teedev_open(qcomtee->teedev);
+	if (IS_ERR(ctx)) {
+		err = PTR_ERR(ctx);
+
+		goto err_dest_wq;
+	}
+
+	qcomtee->ctx = ctx;
+
+	return 0;
+
+err_dest_wq:
+	destroy_workqueue(qcomtee->wq);
+err_unreg_teedev:
+	tee_device_unregister(qcomtee->teedev);
+err_pool_destroy:
+	tee_shm_pool_free(pool);
+err_free_qcomtee:
+	kfree(qcomtee);
+
+	return err;
+}
+
+/**
+ * qcomtee_remove() - Device Removal Routine.
+ * @pdev: platform device information struct.
+ *
+ * It is called by the platform subsystem to alert the driver that it should
+ * release the device.
+ *
+ * QTEE does not provide an API to inform it about a callback object going away.
+ * However, when releasing QTEE objects, any callback object sent to QTEE
+ * previously would be released by QTEE as part of the object release.
+ */
+static void qcomtee_remove(struct platform_device *pdev)
+{
+	struct qcomtee *qcomtee = platform_get_drvdata(pdev);
+
+	teedev_close_context(qcomtee->ctx);
+	/* Wait for RELEASE operations to be processed for QTEE objects. */
+	tee_device_unregister(qcomtee->teedev);
+	destroy_workqueue(qcomtee->wq);
+	tee_shm_pool_free(qcomtee->pool);
+	kfree(qcomtee);
+}
+
+static const struct platform_device_id qcomtee_ids[] = { { "qcomtee", 0 }, {} };
+MODULE_DEVICE_TABLE(platform, qcomtee_ids);
+
+static struct platform_driver qcomtee_platform_driver = {
+	.probe = qcomtee_probe,
+	.remove = qcomtee_remove,
+	.driver = {
+		.name = "qcomtee",
+	},
+	.id_table = qcomtee_ids,
+};
+
+module_platform_driver(qcomtee_platform_driver);
+
+MODULE_AUTHOR("Qualcomm");
+MODULE_DESCRIPTION("QTEE driver");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tee/qcomtee/core.c b/drivers/tee/qcomtee/core.c
new file mode 100644
index 000000000000..162e32db656a
--- /dev/null
+++ b/drivers/tee/qcomtee/core.c
@@ -0,0 +1,801 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/xarray.h>
+
+#include "qcomtee_msg.h"
+#include "qcomtee_private.h"
+
+/* This is the QTEE root object. */
+struct qcomtee_object qcomtee_object_root = {
+	.name = "root",
+	.object_type = QCOMTEE_OBJECT_TYPE_ROOT,
+	.info.qtee_id = QCOMTEE_MSG_OBJECT_ROOT,
+};
+EXPORT_SYMBOL_GPL(qcomtee_object_root);
+
+/* Next argument of type @type after index @i. */
+int qcomtee_next_arg_type(struct qcomtee_arg *u, int i,
+			  enum qcomtee_arg_type type)
+{
+	while (u[i].type != QCOMTEE_ARG_TYPE_INV && u[i].type != type)
+		i++;
+	return i;
+}
+
+/*
+ * QTEE expects IDs with the QCOMTEE_MSG_OBJECT_NS_BIT set for objects
+ * of the QCOMTEE_OBJECT_TYPE_CB type.
+ */
+#define QCOMTEE_OBJECT_ID_START (QCOMTEE_MSG_OBJECT_NS_BIT + 1)
+#define QCOMTEE_OBJECT_ID_END (UINT_MAX)
+
+#define QCOMTEE_OBJECT_SET(p, type, ...) \
+	__QCOMTEE_OBJECT_SET(p, type, ##__VA_ARGS__, 0UL)
+#define __QCOMTEE_OBJECT_SET(p, type, optr, ...)           \
+	do {                                               \
+		(p)->object_type = (type);                 \
+		(p)->info.qtee_id = (unsigned long)(optr); \
+	} while (0)
+
+static struct qcomtee_object *
+qcomtee_qtee_object_alloc(struct qcomtee_object_invoke_ctx *oic,
+			  unsigned int object_id)
+{
+	struct qcomtee *qcomtee = tee_get_drvdata(oic->ctx->teedev);
+	struct qcomtee_object *object __free(kfree);
+
+	object = kzalloc(sizeof(*object), GFP_KERNEL);
+	if (!object)
+		return NULL_QCOMTEE_OBJECT;
+
+	/* If failed, "no-name". */
+	object->name = kasprintf(GFP_KERNEL, "qcomtee-%u", object_id);
+	QCOMTEE_OBJECT_SET(object, QCOMTEE_OBJECT_TYPE_TEE, object_id);
+	kref_init(&object->refcount);
+	/* A QTEE object requires a context for async operations. */
+	object->info.qcomtee_async_ctx = qcomtee->ctx;
+	teedev_ctx_get(object->info.qcomtee_async_ctx);
+
+	return no_free_ptr(object);
+}
+
+void qcomtee_qtee_object_free(struct qcomtee_object *object)
+{
+	/* See qcomtee_qtee_object_alloc(). */
+	teedev_ctx_put(object->info.qcomtee_async_ctx);
+
+	kfree(object->name);
+	kfree(object);
+}
+
+static void qcomtee_object_release(struct kref *refcount)
+{
+	struct qcomtee_object *object;
+	const char *name;
+
+	object = container_of(refcount, struct qcomtee_object, refcount);
+
+	synchronize_rcu();
+
+	switch (typeof_qcomtee_object(object)) {
+	case QCOMTEE_OBJECT_TYPE_TEE:
+		qcomtee_release_tee_object(object);
+
+		break;
+	case QCOMTEE_OBJECT_TYPE_CB:
+		name = object->name;
+
+		if (object->ops->release)
+			object->ops->release(object);
+
+		kfree_const(name);
+
+		break;
+	case QCOMTEE_OBJECT_TYPE_ROOT:
+	case QCOMTEE_OBJECT_TYPE_NULL:
+	default:
+		break;
+	}
+}
+
+/**
+ * qcomtee_object_get() - Increase the object's reference count.
+ * @object: object to increase the reference count.
+ */
+int qcomtee_object_get(struct qcomtee_object *object)
+{
+	if (object != NULL_QCOMTEE_OBJECT && object != ROOT_QCOMTEE_OBJECT)
+		return kref_get_unless_zero(&object->refcount);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcomtee_object_get);
+
+/**
+ * qcomtee_object_put() - Decrease the object's reference count.
+ * @object: object to decrease the reference count.
+ */
+void qcomtee_object_put(struct qcomtee_object *object)
+{
+	if (object != NULL_QCOMTEE_OBJECT && object != ROOT_QCOMTEE_OBJECT)
+		kref_put(&object->refcount, qcomtee_object_release);
+}
+EXPORT_SYMBOL_GPL(qcomtee_object_put);
+
+/*
+ * ''Local Object Table''.
+ * Objects from the kernel exported to QTEE are assigned an ID and stored
+ * in xa_qcom_local_objects (also known as the kernel object table).
+ * QTEE uses this ID to reference the objects using qcomtee_local_object_get().
+ */
+static DEFINE_XARRAY_ALLOC(xa_qcom_local_objects);
+
+static int qcomtee_idx_alloc(u32 *idx, struct qcomtee_object *object)
+{
+	static u32 xa_last_id = QCOMTEE_OBJECT_ID_START;
+
+	/* Every ID allocated here has QCOMTEE_MSG_OBJECT_NS_BIT set. */
+	return xa_alloc_cyclic(&xa_qcom_local_objects, idx, object,
+			       XA_LIMIT(QCOMTEE_OBJECT_ID_START,
+					QCOMTEE_OBJECT_ID_END),
+			       &xa_last_id, GFP_KERNEL);
+}
+
+struct qcomtee_object *qcomtee_idx_erase(u32 idx)
+{
+	if (idx < QCOMTEE_OBJECT_ID_START || idx > QCOMTEE_OBJECT_ID_END)
+		return NULL_QCOMTEE_OBJECT;
+
+	return xa_erase(&xa_qcom_local_objects, idx);
+}
+
+/**
+ * qcomtee_object_id_get() - Get an ID for an object to send to QTEE.
+ * @object: object to assign an ID.
+ * @object_id: object ID.
+ *
+ * This is called on the path to QTEE to construct the message; see
+ * qcomtee_prepare_msg() and qcomtee_update_msg().
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+static int qcomtee_object_id_get(struct qcomtee_object *object,
+				 unsigned int *object_id)
+{
+	u32 idx;
+
+	switch (typeof_qcomtee_object(object)) {
+	case QCOMTEE_OBJECT_TYPE_CB:
+		if (qcomtee_idx_alloc(&idx, object) < 0)
+			return -ENOSPC;
+
+		*object_id = idx;
+
+		break;
+	case QCOMTEE_OBJECT_TYPE_ROOT:
+	case QCOMTEE_OBJECT_TYPE_TEE:
+		*object_id = object->info.qtee_id;
+
+		break;
+	case QCOMTEE_OBJECT_TYPE_NULL:
+		*object_id = QCOMTEE_MSG_OBJECT_NULL;
+
+		break;
+	}
+
+	return 0;
+}
+
+/* Release object ID assigned in qcomtee_object_id_get. */
+static void qcomtee_object_id_put(unsigned int object_id)
+{
+	qcomtee_idx_erase(object_id);
+}
+
+/**
+ * qcomtee_local_object_get() - Get the object referenced by the ID.
+ * @object_id: object ID.
+ *
+ * It is called on the path from QTEE.
+ * It is called on behalf of QTEE to obtain an instance of an object
+ * for a given ID. It increases the object's reference count on success.
+ *
+ * Return: On error, returns %NULL_QCOMTEE_OBJECT.
+ *         On success, returns the object.
+ */
+static struct qcomtee_object *qcomtee_local_object_get(unsigned int object_id)
+{
+	struct qcomtee_object *object;
+
+	/*
+	 * This is not protected by an RCU read lock because we are
+	 * confident that QTEE does not issue a RELEASE request and
+	 * qcomtee_local_object_get() concurrently.
+	 */
+	object = xa_load(&xa_qcom_local_objects, object_id);
+
+	qcomtee_object_get(object);
+
+	return object;
+}
+
+/**
+ * qcomtee_object_user_init() - Initialize an object for the user.
+ * @object: object to initialize.
+ * @ot: type of object as &enum qcomtee_object_type.
+ * @ops: instance of callbacks.
+ * @fmt: name assigned to the object.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_object_user_init(struct qcomtee_object *object,
+			     enum qcomtee_object_type ot,
+			     struct qcomtee_object_operations *ops,
+			     const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	kref_init(&object->refcount);
+	QCOMTEE_OBJECT_SET(object, QCOMTEE_OBJECT_TYPE_NULL);
+
+	va_start(ap, fmt);
+	switch (ot) {
+	case QCOMTEE_OBJECT_TYPE_NULL:
+		ret = 0;
+
+		break;
+	case QCOMTEE_OBJECT_TYPE_CB:
+		object->ops = ops;
+		if (!object->ops->dispatch)
+			return -EINVAL;
+
+		/* If failed, "no-name". */
+		object->name = kvasprintf_const(GFP_KERNEL, fmt, ap);
+		QCOMTEE_OBJECT_SET(object, QCOMTEE_OBJECT_TYPE_CB);
+
+		ret = 0;
+		break;
+	case QCOMTEE_OBJECT_TYPE_ROOT:
+	case QCOMTEE_OBJECT_TYPE_TEE:
+	default:
+		ret = -EINVAL;
+	}
+	va_end(ap);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(qcomtee_object_user_init);
+
+/**
+ * qcomtee_object_type() - Returns the type of object represented by an ID.
+ * @object_id: object ID for the object.
+ *
+ * This is similar to typeof_qcomtee_object(), but instead of receiving an
+ * object as an argument, it receives an object ID. It is used internally
+ * on the return path from QTEE.
+ *
+ * Return: Returns the type of object referenced by @object_id.
+ */
+static enum qcomtee_object_type qcomtee_object_type(unsigned int object_id)
+{
+	if (object_id == QCOMTEE_MSG_OBJECT_NULL)
+		return QCOMTEE_OBJECT_TYPE_NULL;
+
+	if (object_id & QCOMTEE_MSG_OBJECT_NS_BIT)
+		return QCOMTEE_OBJECT_TYPE_CB;
+
+	return QCOMTEE_OBJECT_TYPE_TEE;
+}
+
+/**
+ * qcomtee_object_qtee_init() - Initialize an object for QTEE.
+ * @object: object returned.
+ * @object_id: object ID received from QTEE.
+ *
+ * Return: On failure, returns < 0 and sets @object to %NULL_QCOMTEE_OBJECT.
+ *         On success, returns 0
+ */
+static int qcomtee_object_qtee_init(struct qcomtee_object_invoke_ctx *oic,
+				    struct qcomtee_object **object,
+				    unsigned int object_id)
+{
+	int ret = 0;
+
+	switch (qcomtee_object_type(object_id)) {
+	case QCOMTEE_OBJECT_TYPE_NULL:
+		*object = NULL_QCOMTEE_OBJECT;
+
+		break;
+	case QCOMTEE_OBJECT_TYPE_CB:
+		*object = qcomtee_local_object_get(object_id);
+		if (*object == NULL_QCOMTEE_OBJECT)
+			ret = -EINVAL;
+
+		break;
+
+	default: /* QCOMTEE_OBJECT_TYPE_TEE */
+		*object = qcomtee_qtee_object_alloc(oic, object_id);
+		if (*object == NULL_QCOMTEE_OBJECT)
+			ret = -ENOMEM;
+
+		break;
+	}
+
+	return ret;
+}
+
+/*
+ * ''Marshaling API''
+ * qcomtee_prepare_msg  - Prepare the inbound buffer for sending to QTEE
+ * qcomtee_update_args  - Parse the QTEE response in the inbound buffer
+ * qcomtee_prepare_args - Parse the QTEE request from the outbound buffer
+ * qcomtee_update_msg   - Update the outbound buffer with the response for QTEE
+ */
+
+static int qcomtee_prepare_msg(struct qcomtee_object_invoke_ctx *oic,
+			       struct qcomtee_object *object, u32 op,
+			       struct qcomtee_arg *u)
+{
+	struct qcomtee_msg_object_invoke *msg;
+	unsigned int object_id;
+	int i, ib, ob, io, oo;
+	size_t off;
+
+	/* Use the input message buffer in 'oic'. */
+	msg = oic->in_msg.addr;
+
+	/* Start offset in a message for buffer arguments. */
+	off = qcomtee_msg_buffer_args(struct qcomtee_msg_object_invoke,
+				      qcomtee_args_len(u));
+
+	/* Get the ID of the object being invoked. */
+	if (qcomtee_object_id_get(object, &object_id))
+		return -ENOSPC;
+
+	ib = 0;
+	qcomtee_arg_for_each_input_buffer(i, u) {
+		void *ptr;
+
+		/* Overflow already checked in qcomtee_msg_buffers_alloc(). */
+		msg->args[ib].b.offset = off;
+		msg->args[ib].b.size = u[i].b.size;
+
+		ptr = qcomtee_msg_offset_to_ptr(msg, off);
+		/* Userspace client or kernel client!? */
+		if (!(u[i].flags & QCOMTEE_ARG_FLAGS_UADDR))
+			memcpy(ptr, u[i].b.addr, u[i].b.size);
+		else if (copy_from_user(ptr, u[i].b.uaddr, u[i].b.size))
+			return -EINVAL;
+
+		off += qcomtee_msg_offset_align(u[i].b.size);
+		ib++;
+	}
+
+	ob = ib;
+	qcomtee_arg_for_each_output_buffer(i, u) {
+		/* Overflow already checked in qcomtee_msg_buffers_alloc(). */
+		msg->args[ob].b.offset = off;
+		msg->args[ob].b.size = u[i].b.size;
+
+		off += qcomtee_msg_offset_align(u[i].b.size);
+		ob++;
+	}
+
+	io = ob;
+	qcomtee_arg_for_each_input_object(i, u) {
+		if (qcomtee_object_id_get(u[i].o, &msg->args[io].o)) {
+			/* Put whatever we got. */
+			qcomtee_object_id_put(object_id);
+			for (io--; io >= ob; io--)
+				qcomtee_object_id_put(msg->args[io].o);
+
+			return -ENOSPC;
+		}
+
+		io++;
+	}
+
+	oo = io;
+	qcomtee_arg_for_each_output_object(i, u)
+		oo++;
+
+	/* Set object, operation, and argument counts. */
+	qcomtee_msg_init(msg, object_id, op, ib, ob, io, oo);
+
+	return 0;
+}
+
+/**
+ * qcomtee_update_args() - Parse the QTEE response in the inbound buffer.
+ * @u: array of arguments for the invocation.
+ * @oic: context to use for the invocation.
+ *
+ * @u must be the same as the one used in qcomtee_prepare_msg() when
+ * initializing the inbound buffer.
+ *
+ * On failure, it continues processing the QTEE message. The caller should
+ * do the necessary cleanup, including calling qcomtee_object_put()
+ * on the output objects.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+static int qcomtee_update_args(struct qcomtee_arg *u,
+			       struct qcomtee_object_invoke_ctx *oic)
+{
+	struct qcomtee_msg_object_invoke *msg;
+	int i, ib, ob, io, oo;
+	int ret = 0;
+
+	/* Use the input message buffer in 'oic'. */
+	msg = oic->in_msg.addr;
+
+	ib = 0;
+	qcomtee_arg_for_each_input_buffer(i, u)
+		ib++;
+
+	ob = ib;
+	qcomtee_arg_for_each_output_buffer(i, u) {
+		void *ptr;
+
+		/* QTEE can override the size to a smaller value. */
+		u[i].b.size = msg->args[ob].b.size;
+
+		ptr = qcomtee_msg_offset_to_ptr(msg, msg->args[ob].b.offset);
+		/* Userspace client or kernel client!? */
+		if (!(u[i].flags & QCOMTEE_ARG_FLAGS_UADDR))
+			memcpy(u[i].b.addr, ptr, u[i].b.size);
+		else if (copy_to_user(u[i].b.uaddr, ptr, u[i].b.size))
+			ret = -EINVAL;
+
+		ob++;
+	}
+
+	io = ob;
+	qcomtee_arg_for_each_input_object(i, u)
+		io++;
+
+	oo = io;
+	qcomtee_arg_for_each_output_object(i, u) {
+		if (qcomtee_object_qtee_init(oic, &u[i].o, msg->args[oo].o))
+			ret = -EINVAL;
+
+		oo++;
+	}
+
+	return ret;
+}
+
+/**
+ * qcomtee_prepare_args() - Parse the QTEE request from the outbound buffer.
+ * @oic: context to use for the invocation.
+ *
+ * It initializes &qcomtee_object_invoke_ctx->u based on the QTEE request in
+ * the outbound buffer. It sets %QCOMTEE_ARG_TYPE_INV at the end of the array.
+ *
+ * On failure, it continues processing the QTEE message. The caller should
+ * do the necessary cleanup, including calling qcomtee_object_put()
+ * on the input objects.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+static int qcomtee_prepare_args(struct qcomtee_object_invoke_ctx *oic)
+{
+	struct qcomtee_msg_callback *msg;
+	union qcomtee_msg_arg *arg;
+	int i, ret = 0;
+
+	/* Use the output message buffer in 'oic'. */
+	msg = oic->out_msg.addr;
+
+	qcomtee_msg_for_each_input_buffer(i, msg) {
+		arg = &msg->args[i];
+		oic->u[i].b.addr =
+			qcomtee_msg_offset_to_ptr(msg, arg->b.offset);
+		oic->u[i].b.size = arg->b.size;
+		oic->u[i].type = QCOMTEE_ARG_TYPE_IB;
+	}
+
+	qcomtee_msg_for_each_output_buffer(i, msg) {
+		arg = &msg->args[i];
+		oic->u[i].b.addr =
+			qcomtee_msg_offset_to_ptr(msg, arg->b.offset);
+		oic->u[i].b.size = arg->b.size;
+		oic->u[i].type = QCOMTEE_ARG_TYPE_OB;
+	}
+
+	qcomtee_msg_for_each_input_object(i, msg) {
+		if (qcomtee_object_qtee_init(oic, &oic->u[i].o, msg->args[i].o))
+			ret = -EINVAL;
+
+		oic->u[i].type = QCOMTEE_ARG_TYPE_IO;
+	}
+
+	qcomtee_msg_for_each_output_object(i, msg)
+		oic->u[i].type = QCOMTEE_ARG_TYPE_OO;
+
+	/* End of Arguments. */
+	oic->u[i].type = QCOMTEE_ARG_TYPE_INV;
+
+	return ret;
+}
+
+static int qcomtee_update_msg(struct qcomtee_object_invoke_ctx *oic)
+{
+	struct qcomtee_msg_callback *msg;
+	int i, ib, ob, io, oo;
+
+	/* Use the output message buffer in 'oic'. */
+	msg = oic->out_msg.addr;
+
+	ib = 0;
+	qcomtee_arg_for_each_input_buffer(i, oic->u)
+		ib++;
+
+	ob = ib;
+	qcomtee_arg_for_each_output_buffer(i, oic->u) {
+		/* Only reduce size; never increase it. */
+		if (msg->args[ob].b.size < oic->u[i].b.size)
+			return -EINVAL;
+
+		msg->args[ob].b.size = oic->u[i].b.size;
+		ob++;
+	}
+
+	io = ob;
+	qcomtee_arg_for_each_input_object(i, oic->u)
+		io++;
+
+	oo = io;
+	qcomtee_arg_for_each_output_object(i, oic->u) {
+		if (qcomtee_object_id_get(oic->u[i].o, &msg->args[oo].o)) {
+			/* Put whatever we got. */
+			for (oo--; oo >= io; oo--)
+				qcomtee_object_id_put(msg->args[oo].o);
+
+			return -ENOSPC;
+		}
+
+		oo++;
+	}
+
+	return 0;
+}
+
+/* Invoke a callback object. */
+static void qcomtee_cb_object_invoke(struct qcomtee_object_invoke_ctx *oic,
+				     struct qcomtee_msg_callback *msg)
+{
+	int i, errno;
+	u32 op;
+
+	/* Get the object being invoked. */
+	unsigned int object_id = msg->cxt;
+	struct qcomtee_object *object;
+
+	/* QTEE cannot invoke a NULL object or objects it hosts. */
+	if (qcomtee_object_type(object_id) == QCOMTEE_OBJECT_TYPE_NULL ||
+	    qcomtee_object_type(object_id) == QCOMTEE_OBJECT_TYPE_TEE) {
+		errno = -EINVAL;
+		goto out;
+	}
+
+	object = qcomtee_local_object_get(object_id);
+	if (object == NULL_QCOMTEE_OBJECT) {
+		errno = -EINVAL;
+		goto out;
+	}
+
+	oic->object = object;
+
+	/* Filter bits used by transport. */
+	op = msg->op & QCOMTEE_MSG_OBJECT_OP_MASK;
+
+	switch (op) {
+	case QCOMTEE_MSG_OBJECT_OP_RELEASE:
+		qcomtee_object_id_put(object_id);
+		qcomtee_object_put(object);
+		errno = 0;
+
+		break;
+	case QCOMTEE_MSG_OBJECT_OP_RETAIN:
+		qcomtee_object_get(object);
+		errno = 0;
+
+		break;
+	default:
+		errno = qcomtee_prepare_args(oic);
+		if (errno) {
+			/* Release any object that arrived as input. */
+			qcomtee_arg_for_each_input_buffer(i, oic->u)
+				qcomtee_object_put(oic->u[i].o);
+
+			break;
+		}
+
+		errno = object->ops->dispatch(oic, object, op, oic->u);
+		if (!errno) {
+			/* On success, notify at the appropriate time. */
+			oic->flags |= QCOMTEE_OIC_FLAG_NOTIFY;
+		}
+	}
+
+out:
+
+	oic->errno = errno;
+}
+
+/**
+ * qcomtee_qtee_objects_put() - Put the callback objects in the argument array.
+ * @u: array of arguments.
+ *
+ * When qcomtee_object_do_invoke_internal() is successfully invoked,
+ * QTEE takes ownership of the callback objects. If the invocation fails,
+ * qcomtee_object_do_invoke_internal() calls qcomtee_qtee_objects_put()
+ * to mimic the release of callback objects by QTEE.
+ */
+static void qcomtee_qtee_objects_put(struct qcomtee_arg *u)
+{
+	int i;
+
+	qcomtee_arg_for_each_input_object(i, u) {
+		if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)
+			qcomtee_object_put(u[i].o);
+	}
+}
+
+/**
+ * qcomtee_object_do_invoke_internal() - Submit an invocation for an object.
+ * @oic: context to use for the current invocation.
+ * @object: object being invoked.
+ * @op: requested operation on the object.
+ * @u: array of arguments for the current invocation.
+ * @result: result returned from QTEE.
+ *
+ * The caller is responsible for keeping track of the refcount for each
+ * object, including @object. On return, the caller loses ownership of all
+ * input objects of type %QCOMTEE_OBJECT_TYPE_CB.
+ *
+ * Return: On success, returns 0. On error, returns -EAGAIN if invocation
+ * failed and the user may retry the invocation, -ENODEV on fatal failure.
+ */
+int qcomtee_object_do_invoke_internal(struct qcomtee_object_invoke_ctx *oic,
+				      struct qcomtee_object *object, u32 op,
+				      struct qcomtee_arg *u, int *result)
+{
+	struct qcomtee_msg_callback *cb_msg;
+	struct qcomtee_object *qto;
+	int i, ret, errno;
+	u64 res_type;
+
+	/* Allocate inbound and outbound buffers. */
+	if (qcomtee_msg_buffers_alloc(oic, u)) {
+		qcomtee_qtee_objects_put(u);
+
+		return -EAGAIN;
+	}
+
+	if (qcomtee_prepare_msg(oic, object, op, u)) {
+		qcomtee_qtee_objects_put(u);
+
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	/* Use input message buffer in 'oic'. */
+	cb_msg = oic->out_msg.addr;
+
+	while (1) {
+		if (oic->flags & QCOMTEE_OIC_FLAG_BUSY) {
+			errno = oic->errno;
+			if (!errno)
+				errno = qcomtee_update_msg(oic);
+			qcomtee_msg_set_result(cb_msg, errno);
+		}
+
+		/* Invoke the remote object. */
+		ret = qcomtee_object_invoke_ctx_invoke(oic, result, &res_type);
+
+		if (oic->flags & QCOMTEE_OIC_FLAG_BUSY) {
+			qto = oic->object;
+			if (qto) {
+				if (oic->flags & QCOMTEE_OIC_FLAG_NOTIFY) {
+					/* Don't care about the exact errno. */
+					if (qto->ops->notify)
+						qto->ops->notify(oic, qto,
+								 errno || ret);
+				}
+
+				/* Get is in qcomtee_cb_object_invoke(). */
+				qcomtee_object_put(qto);
+			}
+
+			oic->object = NULL_QCOMTEE_OBJECT;
+			oic->flags &= ~(QCOMTEE_OIC_FLAG_BUSY |
+					QCOMTEE_OIC_FLAG_NOTIFY);
+		}
+
+		if (ret) {
+			if (!(oic->flags & QCOMTEE_OIC_FLAG_SHARED)) {
+				qcomtee_qtee_objects_put(u);
+
+				ret = -EAGAIN;
+			} else {
+				/*
+				 * On error, there is no clean way to exit.
+				 * For some reason, we cannot communicate with
+				 * QTEE, so we cannot notify QTEE about the
+				 * failure and do further cleanup.
+				 */
+				ret = -ENODEV;
+			}
+
+			goto out;
+
+		} else {
+			/*
+			 * QTEE obtained ownership of QCOMTEE_OBJECT_TYPE_CB
+			 * input objects in 'u'. On further failure, QTEE is
+			 * responsible for releasing them.
+			 */
+			oic->flags |= QCOMTEE_OIC_FLAG_SHARED;
+		}
+
+		/* Is it a callback request? */
+		if (res_type != QCOMTEE_RESULT_INBOUND_REQ_NEEDED) {
+			if (!*result) {
+				ret = qcomtee_update_args(u, oic);
+				if (ret) {
+					/* Put output objects. Retry. */
+					qcomtee_arg_for_each_output_object(i, u)
+						qcomtee_object_put(u[i].o);
+
+					ret = -EAGAIN;
+				}
+			}
+
+			break;
+
+		} else {
+			oic->flags |= QCOMTEE_OIC_FLAG_BUSY;
+
+			qcomtee_fetch_async_reqs(oic);
+			qcomtee_cb_object_invoke(oic, cb_msg);
+		}
+	}
+
+	qcomtee_fetch_async_reqs(oic);
+out:
+	qcomtee_msg_buffers_free(oic);
+
+	return ret;
+}
+
+int qcomtee_object_do_invoke(struct qcomtee_object_invoke_ctx *oic,
+			     struct qcomtee_object *object, u32 op,
+			     struct qcomtee_arg *u, int *result)
+{
+	/* User can not set bits used by transport. */
+	if (op & ~QCOMTEE_MSG_OBJECT_OP_MASK)
+		return -EINVAL;
+
+	/* User can only invoke QTEE hosted objects. */
+	if (typeof_qcomtee_object(object) != QCOMTEE_OBJECT_TYPE_TEE &&
+	    typeof_qcomtee_object(object) != QCOMTEE_OBJECT_TYPE_ROOT)
+		return -EINVAL;
+
+	/* User cannot directly issue these operations to QTEE. */
+	if (op == QCOMTEE_MSG_OBJECT_OP_RELEASE)
+		return -EINVAL;
+
+	return qcomtee_object_do_invoke_internal(oic, object, op, u, result);
+}
+EXPORT_SYMBOL_GPL(qcomtee_object_do_invoke);
diff --git a/drivers/tee/qcomtee/qcom_scm.c b/drivers/tee/qcomtee/qcom_scm.c
new file mode 100644
index 000000000000..38a3d080f86d
--- /dev/null
+++ b/drivers/tee/qcomtee/qcom_scm.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/firmware/qcom/qcom_scm.h>
+
+#include "qcomtee_private.h"
+
+int qcomtee_object_invoke_ctx_invoke(struct qcomtee_object_invoke_ctx *oic,
+				     int *result, u64 *res_type)
+{
+	phys_addr_t out_msg_paddr;
+	phys_addr_t in_msg_paddr;
+	int ret;
+	u64 res;
+
+	tee_shm_get_pa(oic->out_shm, 0, &out_msg_paddr);
+	tee_shm_get_pa(oic->in_shm, 0, &in_msg_paddr);
+	if (!(oic->flags & QCOMTEE_OIC_FLAG_BUSY)) {
+		/* Direct QTEE object invocation. */
+		ret = qcom_scm_qtee_invoke_smc(in_msg_paddr, oic->in_msg.size,
+					       out_msg_paddr, oic->out_msg.size,
+					       &res, res_type);
+	} else {
+		/* Submit callback response. */
+		ret = qcom_scm_qtee_callback_response(out_msg_paddr,
+						      oic->out_msg.size,
+						      &res, res_type);
+	}
+
+	if (ret)
+		pr_err("QTEE returned with %d.\n", ret);
+	else
+		*result = (int)res;
+
+	return ret;
+}
diff --git a/drivers/tee/qcomtee/qcomtee_msg.h b/drivers/tee/qcomtee/qcomtee_msg.h
new file mode 100644
index 000000000000..33a6b426153c
--- /dev/null
+++ b/drivers/tee/qcomtee/qcomtee_msg.h
@@ -0,0 +1,239 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef QCOMTEE_MSG_H
+#define QCOMTEE_MSG_H
+
+#include <linux/firmware/qcom/qcom_tee.h>
+
+/**
+ * DOC: ''Qualcomm TEE'' (QTEE) Transport Message
+ *
+ * There are two buffers shared with QTEE: inbound and outbound buffers.
+ * The inbound buffer is used for direct object invocation, and the outbound
+ * buffer is used to make a request from QTEE to the kernel; i.e., a callback
+ * request.
+ *
+ * The unused tail of the outbound buffer is also used for sending and
+ * receiving asynchronous messages. An asynchronous message is independent of
+ * the current object invocation (i.e., contents of the inbound buffer) or
+ * callback request (i.e., the head of the outbound buffer); see
+ * qcomtee_get_async_buffer(). It is used by endpoints (QTEE or kernel) as an
+ * optimization to reduce the number of context switches between the secure and
+ * non-secure worlds.
+ *
+ * For instance, QTEE never sends an explicit callback request to release an
+ * object in the kernel. Instead, it sends asynchronous release messages in the
+ * outbound buffer when QTEE returns from the previous direct object invocation,
+ * or appends asynchronous release messages after the current callback request.
+ *
+ * QTEE supports two types of arguments in a message: buffer and object
+ * arguments. Depending on the direction of data flow, they could be input
+ * buffer (IO) to QTEE, output buffer (OB) from QTEE, input object (IO) to QTEE,
+ * or output object (OO) from QTEE. Object arguments hold object IDs. Buffer
+ * arguments hold (offset, size) pairs into the inbound or outbound buffers.
+ *
+ * QTEE holds an object table for objects it hosts and exposes to the kernel.
+ * An object ID is an index to the object table in QTEE.
+ *
+ * For the direct object invocation message format in the inbound buffer, see
+ * &struct qcomtee_msg_object_invoke. For the callback request message format
+ * in the outbound buffer, see &struct qcomtee_msg_callback. For the message
+ * format for asynchronous messages in the outbound buffer, see
+ * &struct qcomtee_async_msg_hdr.
+ */
+
+/**
+ * define QCOMTEE_MSG_OBJECT_NS_BIT - Non-secure bit
+ *
+ * Object ID is a globally unique 32-bit number. IDs referencing objects
+ * in the kernel should have %QCOMTEE_MSG_OBJECT_NS_BIT set.
+ */
+#define QCOMTEE_MSG_OBJECT_NS_BIT BIT(31)
+
+/* Static object IDs recognized by QTEE. */
+#define QCOMTEE_MSG_OBJECT_NULL (0U)
+#define QCOMTEE_MSG_OBJECT_ROOT (1U)
+
+/* Definitions from QTEE as part of the transport protocol. */
+
+/* qcomtee_msg_arg is an argument as recognized by QTEE. */
+union qcomtee_msg_arg {
+	struct {
+		u32 offset;
+		u32 size;
+	} b;
+	u32 o;
+};
+
+/* BI and BO payloads in QTEE messages should be at 64-bit boundaries. */
+#define qcomtee_msg_offset_align(o) ALIGN((o), sizeof(u64))
+
+/* Operations for objects are 32-bit. Transport uses the upper 16 bits. */
+#define QCOMTEE_MSG_OBJECT_OP_MASK GENMASK(15, 0)
+
+/* Reserved Operation IDs sent to QTEE: */
+/* QCOMTEE_MSG_OBJECT_OP_RELEASE - Reduces the refcount and releases the object.
+ * QCOMTEE_MSG_OBJECT_OP_RETAIN  - Increases the refcount.
+ *
+ * These operation IDs are valid for all objects.
+ */
+
+#define QCOMTEE_MSG_OBJECT_OP_RELEASE (QCOMTEE_MSG_OBJECT_OP_MASK - 0)
+#define QCOMTEE_MSG_OBJECT_OP_RETAIN  (QCOMTEE_MSG_OBJECT_OP_MASK - 1)
+
+/* Subset of operations supported by QTEE root object. */
+
+#define QCOMTEE_ROOT_OP_REGISTER_WITH_CREDENTIALS 5
+#define QCOMTEE_ROOT_OP_NOTIFY_DOMAIN_CHANGE 4
+#define QCOMTEE_ROOT_OP_ADCI_ACCEPT 8
+#define QCOMTEE_ROOT_OP_ADCI_SHUTDOWN 9
+
+/* Response types as returned from qcomtee_object_invoke_ctx_invoke(). */
+
+/* The message contains a callback request. */
+#define QCOMTEE_RESULT_INBOUND_REQ_NEEDED 3
+
+/**
+ * struct qcomtee_msg_object_invoke - Direct object invocation message.
+ * @ctx: object ID hosted in QTEE.
+ * @op: operation for the object.
+ * @counts: number of different types of arguments in @args.
+ * @args: array of arguments.
+ *
+ * @counts consists of 4 * 4-bit fields. Bits 0 - 3 represent the number of
+ * input buffers, bits 4 - 7 represent the number of output buffers,
+ * bits 8 - 11 represent the number of input objects, and bits 12 - 15
+ * represent the number of output objects. The remaining bits should be zero.
+ *
+ * The maximum number of arguments of each type is defined by
+ * %QCOMTEE_ARGS_PER_TYPE.
+ */
+struct qcomtee_msg_object_invoke {
+	u32 cxt;
+	u32 op;
+	u32 counts;
+	union qcomtee_msg_arg args[];
+};
+
+/**
+ * struct qcomtee_msg_callback - Callback request message.
+ * @result: result of operation @op on the object referenced by @cxt.
+ * @cxt: object ID hosted in the kernel.
+ * @op: operation for the object.
+ * @counts: number of different types of arguments in @args.
+ * @args: array of arguments.
+ *
+ * For details of @counts, see &qcomtee_msg_object_invoke.counts.
+ */
+struct qcomtee_msg_callback {
+	u32 result;
+	u32 cxt;
+	u32 op;
+	u32 counts;
+	union qcomtee_msg_arg args[];
+};
+
+/* Offset in the message for the beginning of the buffer argument's contents. */
+#define qcomtee_msg_buffer_args(t, n) \
+	qcomtee_msg_offset_align(struct_size_t(t, args, n))
+/* Pointer to the beginning of a buffer argument's content at an offset. */
+#define qcomtee_msg_offset_to_ptr(m, off) ((void *)&((char *)(m))[(off)])
+
+/* Some helpers to manage msg.counts. */
+
+#define QCOMTEE_MSG_NUM_IB(x) ((x) & 0xfU)
+#define QCOMTEE_MSG_NUM_OB(x) (((x) >> 4) & 0xfU)
+#define QCOMTEE_MSG_NUM_IO(x) (((x) >> 8) & 0xfU)
+#define QCOMTEE_MSG_NUM_OO(x) (((x) >> 12) & 0xfU)
+
+#define QCOMTEE_MSG_IDX_IB(x) (0U)
+#define QCOMTEE_MSG_IDX_OB(x) (QCOMTEE_MSG_IDX_IB(x) + QCOMTEE_MSG_NUM_IB(x))
+#define QCOMTEE_MSG_IDX_IO(x) (QCOMTEE_MSG_IDX_OB(x) + QCOMTEE_MSG_NUM_OB(x))
+#define QCOMTEE_MSG_IDX_OO(x) (QCOMTEE_MSG_IDX_IO(x) + QCOMTEE_MSG_NUM_IO(x))
+
+#define qcomtee_msg_for_each(i, c, type)    \
+	for (i = QCOMTEE_MSG_IDX_##type(c); \
+	     i < (QCOMTEE_MSG_IDX_##type(c) + QCOMTEE_MSG_NUM_##type(c)); i++)
+
+#define qcomtee_msg_for_each_input_buffer(i, m) \
+	qcomtee_msg_for_each(i, (m)->counts, IB)
+#define qcomtee_msg_for_each_output_buffer(i, m) \
+	qcomtee_msg_for_each(i, (m)->counts, OB)
+#define qcomtee_msg_for_each_input_object(i, m) \
+	qcomtee_msg_for_each(i, (m)->counts, IO)
+#define qcomtee_msg_for_each_output_object(i, m) \
+	qcomtee_msg_for_each(i, (m)->counts, OO)
+
+/* Sum of arguments in a message. */
+#define qcomtee_msg_args(m) \
+	(QCOMTEE_MSG_IDX_OO((m)->counts) + QCOMTEE_MSG_NUM_OO((m)->counts))
+
+static inline void qcomtee_msg_init(struct qcomtee_msg_object_invoke *msg,
+				    u32 cxt, u32 op, int in_buffer,
+				    int out_buffer, int in_object,
+				    int out_object)
+{
+	msg->counts |= (in_buffer & 0xfU);
+	msg->counts |= ((out_buffer - in_buffer) & 0xfU) << 4;
+	msg->counts |= ((in_object - out_buffer) & 0xfU) << 8;
+	msg->counts |= ((out_object - in_object) & 0xfU) << 12;
+	msg->cxt = cxt;
+	msg->op = op;
+}
+
+/* Generic error codes. */
+#define QCOMTEE_MSG_OK			0    /* non-specific success code. */
+#define QCOMTEE_MSG_ERROR		1    /* non-specific error. */
+#define QCOMTEE_MSG_ERROR_INVALID	2    /* unsupported/unrecognized request. */
+#define QCOMTEE_MSG_ERROR_SIZE_IN	3    /* supplied buffer/string too large. */
+#define QCOMTEE_MSG_ERROR_SIZE_OUT	4    /* supplied output buffer too small. */
+#define QCOMTEE_MSG_ERROR_USERBASE	10   /* start of user-defined error range. */
+
+/* Transport layer error codes. */
+#define QCOMTEE_MSG_ERROR_DEFUNCT	-90  /* object no longer exists. */
+#define QCOMTEE_MSG_ERROR_ABORT		-91  /* calling thread must exit. */
+#define QCOMTEE_MSG_ERROR_BADOBJ	-92  /* invalid object context. */
+#define QCOMTEE_MSG_ERROR_NOSLOTS	-93  /* caller's object table full. */
+#define QCOMTEE_MSG_ERROR_MAXARGS	-94  /* too many args. */
+#define QCOMTEE_MSG_ERROR_MAXDATA	-95  /* buffers too large. */
+#define QCOMTEE_MSG_ERROR_UNAVAIL	-96  /* the request could not be processed. */
+#define QCOMTEE_MSG_ERROR_KMEM		-97  /* kernel out of memory. */
+#define QCOMTEE_MSG_ERROR_REMOTE	-98  /* local method sent to remote object. */
+#define QCOMTEE_MSG_ERROR_BUSY		-99  /* Object is busy. */
+#define QCOMTEE_MSG_ERROR_TIMEOUT	-103 /* Call Back Object invocation timed out. */
+
+static inline void qcomtee_msg_set_result(struct qcomtee_msg_callback *cb_msg,
+					  int err)
+{
+	if (!err) {
+		cb_msg->result = QCOMTEE_MSG_OK;
+	} else if (err < 0) {
+		/* If err < 0, then it is a transport error. */
+		switch (err) {
+		case -ENOMEM:
+			cb_msg->result = QCOMTEE_MSG_ERROR_KMEM;
+			break;
+		case -ENODEV:
+			cb_msg->result = QCOMTEE_MSG_ERROR_DEFUNCT;
+			break;
+		case -ENOSPC:
+		case -EBUSY:
+			cb_msg->result = QCOMTEE_MSG_ERROR_BUSY;
+			break;
+		case -EBADF:
+		case -EINVAL:
+			cb_msg->result = QCOMTEE_MSG_ERROR_UNAVAIL;
+			break;
+		default:
+			cb_msg->result = QCOMTEE_MSG_ERROR;
+		}
+	} else {
+		/* If err > 0, then it is user defined error, pass it as is. */
+		cb_msg->result = err;
+	}
+}
+
+#endif /* QCOMTEE_MSG_H */
diff --git a/drivers/tee/qcomtee/qcomtee_private.h b/drivers/tee/qcomtee/qcomtee_private.h
new file mode 100644
index 000000000000..ab3acad40359
--- /dev/null
+++ b/drivers/tee/qcomtee/qcomtee_private.h
@@ -0,0 +1,222 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef QCOMTEE_PRIVATE_H
+#define QCOMTEE_PRIVATE_H
+
+#include <linux/firmware/qcom/qcom_tee.h>
+#include <linux/kobject.h>
+#include <linux/tee_core.h>
+
+#include "qcomtee_msg.h"
+
+/* Flags relating to object reference. */
+#define QCOMTEE_OBJREF_FLAG_TEE BIT(0)
+#define QCOMTEE_OBJREF_FLAG_USER BIT(1)
+
+/**
+ * struct qcomtee - Main service struct.
+ * @teedev: client device.
+ * @pool: shared memory pool.
+ * @ctx: driver private context.
+ * @wq: workqueue for QTEE async operations.
+ */
+struct qcomtee {
+	struct tee_device *teedev;
+	struct tee_shm_pool *pool;
+	struct tee_context *ctx;
+	struct workqueue_struct *wq;
+};
+
+struct qcomtee_object *qcomtee_idx_erase(u32 idx);
+void qcomtee_qtee_object_free(struct qcomtee_object *object);
+void qcomtee_fetch_async_reqs(struct qcomtee_object_invoke_ctx *oic);
+void qcomtee_release_tee_object(struct qcomtee_object *object);
+
+struct tee_shm_pool *qcomtee_shm_pool_alloc(void);
+void qcomtee_msg_buffers_free(struct qcomtee_object_invoke_ctx *oic);
+int qcomtee_msg_buffers_alloc(struct qcomtee_object_invoke_ctx *oic,
+			      struct qcomtee_arg *u);
+
+int qcomtee_object_invoke_ctx_invoke(struct qcomtee_object_invoke_ctx *oic,
+				     int *result, u64 *res_type);
+
+/**
+ * qcomtee_object_do_invoke_internal() - Submit an invocation for an object.
+ * @oic: context to use for the current invocation.
+ * @object: object being invoked.
+ * @op: requested operation on the object.
+ * @u: array of arguments for the current invocation.
+ * @result: result returned from QTEE.
+ *
+ * The caller is responsible for keeping track of the refcount for each
+ * object, including @object. On return, the caller loses ownership of all
+ * input objects of type %QCOMTEE_OBJECT_TYPE_CB.
+ *
+ * Return: On success, returns 0. On error, returns -EAGAIN if invocation
+ * failed and the user may retry the invocation, -ENODEV on fatal failure.
+ */
+int qcomtee_object_do_invoke_internal(struct qcomtee_object_invoke_ctx *oic,
+				      struct qcomtee_object *object, u32 op,
+				      struct qcomtee_arg *u, int *result);
+
+/**
+ * struct qcomtee_context_data - Clients' or supplicants' context.
+ * @qtee_objects_idr: QTEE objects in this context.
+ * @qtee_lock: spinlock for @qtee_objects_idr.
+ * @reqs_idr: requests currently being processed in this context.
+ * @reqs_list: FIFO for requests.
+ * @reqs_lock: mutex for @reqs_idr, @reqs_list and request states.
+ * @req_c: completion used when the supplicant is waiting for requests.
+ * @released: state of this context.
+ */
+struct qcomtee_context_data {
+	struct idr qtee_objects_idr;
+	/* Synchronize access to @qtee_objects_idr. */
+	spinlock_t qtee_lock;
+
+	struct idr reqs_idr;
+	struct list_head reqs_list;
+	/* Synchronize access to @reqs_idr, @reqs_list and updating requests states. */
+	struct mutex reqs_lock;
+
+	struct completion req_c;
+
+	int released;
+};
+
+/**
+ * qcomtee_context_add_qtee_object() - Add a QTEE object to the context.
+ * @param: TEE parameter representing @object.
+ * @object: QTEE object.
+ * @ctx: context to add the object.
+ *
+ * It assumes @object is %QCOMTEE_OBJECT_TYPE_TEE and the caller has already
+ * issued qcomtee_object_get() for @object.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_context_add_qtee_object(struct tee_param *param,
+				    struct qcomtee_object *object,
+				    struct tee_context *ctx);
+
+/* Retrieve the QTEE object added with qcomtee_context_add_qtee_object(). */
+int qcomtee_context_find_qtee_object(struct qcomtee_object **object,
+				     struct tee_param *param,
+				     struct tee_context *ctx);
+
+/**
+ * qcomtee_context_del_qtee_object() - Delete a QTEE object from the context.
+ * @param: TEE parameter representing @object.
+ * @ctx: context for deleting the object.
+ *
+ * The @param has been initialized by qcomtee_context_add_qtee_object().
+ */
+void qcomtee_context_del_qtee_object(struct tee_param *param,
+				     struct tee_context *ctx);
+
+/**
+ * qcomtee_objref_to_arg() - Convert OBJREF parameter to QTEE argument.
+ * @arg: QTEE argument.
+ * @param: TEE parameter.
+ * @ctx: context in which the conversion should happen.
+ *
+ * It assumes @param is an OBJREF.
+ * It does not set @arg.type; the caller should initialize it to a correct
+ * &enum qcomtee_arg_type value. It gets the object's refcount in @arg;
+ * the caller should manage to put it afterward.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_objref_to_arg(struct qcomtee_arg *arg, struct tee_param *param,
+			  struct tee_context *ctx);
+
+/**
+ * qcomtee_objref_from_arg() - Convert QTEE argument to OBJREF param.
+ * @param: TEE parameter.
+ * @arg: QTEE argument.
+ * @ctx: context in which the conversion should happen.
+ *
+ * It assumes @arg is of %QCOMTEE_ARG_TYPE_IO or %QCOMTEE_ARG_TYPE_OO.
+ * It does not set @param.attr; the caller should initialize it to a
+ * correct type.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_objref_from_arg(struct tee_param *param, struct qcomtee_arg *arg,
+			    struct tee_context *ctx);
+
+/* OBJECTS: */
+
+/* (1) User Object API. */
+
+/* Is it a user object? */
+int is_qcomtee_user_object(struct qcomtee_object *object);
+
+/* Set the user object's 'notify on release' flag. */
+void qcomtee_user_object_set_notify(struct qcomtee_object *object, bool notify);
+
+/* This is called when there are no more users for the ctxdata. */
+void qcomtee_requests_destroy(struct qcomtee_context_data *ctxdata);
+
+/**
+ * qcomtee_user_param_to_object() - OBJREF parameter to &struct qcomtee_object.
+ * @object: object returned.
+ * @param: TEE parameter.
+ * @ctx: context in which the conversion should happen.
+ *
+ * @param is an OBJREF with %QCOMTEE_OBJREF_FLAG_USER flags.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_user_param_to_object(struct qcomtee_object **object,
+				 struct tee_param *param,
+				 struct tee_context *ctx);
+
+/* Reverse what qcomtee_user_param_to_object() does. */
+int qcomtee_user_param_from_object(struct tee_param *param,
+				   struct qcomtee_object *object,
+				   struct tee_context *ctx);
+
+struct qcomtee_user_object_request_data {
+	int id; /* ID assigned to the request. */
+	u64 object_id; /* Object ID being invoked by QTEE. */
+	u32 op; /* Requested operation on object. */
+	int np; /* Number of parameters in the request.*/
+};
+
+/**
+ * qcomtee_user_object_select() - Select a request for a user object.
+ * @ctx: context to look for a user object.
+ * @params: parameters for @op.
+ * @num_params: number of elements in the parameter array.
+ * @uaddr: user buffer for output UBUF parameters.
+ * @size: size of user buffer @uaddr.
+ * @data: information for the selected request.
+ *
+ * @params is filled along with @data for the selected request.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_user_object_select(struct tee_context *ctx,
+			       struct tee_param *params, int num_params,
+			       void __user *uaddr, size_t size,
+			       struct qcomtee_user_object_request_data *data);
+
+/**
+ * qcomtee_user_object_submit() - Submit a response for a user object.
+ * @ctx: context to look for a user object.
+ * @params: returned parameters.
+ * @num_params: number of elements in the parameter array.
+ * @req_id: request ID for the response.
+ * @errno: result of user object invocation.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_user_object_submit(struct tee_context *ctx,
+			       struct tee_param *params, int num_params,
+			       int req_id, int errno);
+
+#endif /* QCOMTEE_PRIVATE_H */
diff --git a/drivers/tee/qcomtee/release.c b/drivers/tee/qcomtee/release.c
new file mode 100644
index 000000000000..7d149ef3d26f
--- /dev/null
+++ b/drivers/tee/qcomtee/release.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include "qcomtee_private.h"
+
+static void qcomtee_destroy_user_object(struct work_struct *work)
+{
+	struct qcomtee_object *object;
+	struct qcomtee *qcomtee;
+	int ret, result;
+
+	static struct qcomtee_object_invoke_ctx oic;
+	/* RELEASE does not require any argument. */
+	static struct qcomtee_arg args[] = { { .type = QCOMTEE_ARG_TYPE_INV } };
+
+	object = container_of(work, struct qcomtee_object, work);
+	qcomtee = tee_get_drvdata(object->info.qcomtee_async_ctx->teedev);
+	/* Get the TEE context used for asynchronous operations. */
+	oic.ctx = object->info.qcomtee_async_ctx;
+
+	ret = qcomtee_object_do_invoke_internal(&oic, object,
+						QCOMTEE_MSG_OBJECT_OP_RELEASE,
+						args, &result);
+
+	/* Is it safe to retry the release? */
+	if (ret == -EAGAIN) {
+		queue_work(qcomtee->wq, &object->work);
+	} else {
+		if (ret || result)
+			pr_err("%s: %s release failed, ret = %d (%x).\n",
+			       __func__, qcomtee_object_name(object), ret,
+			       result);
+
+		qcomtee_qtee_object_free(object);
+	}
+}
+
+/* qcomtee_release_tee_object puts object in release work queue. */
+void qcomtee_release_tee_object(struct qcomtee_object *object)
+{
+	struct qcomtee *qcomtee =
+		tee_get_drvdata(object->info.qcomtee_async_ctx->teedev);
+
+	INIT_WORK(&object->work, qcomtee_destroy_user_object);
+	queue_work(qcomtee->wq, &object->work);
+}
diff --git a/drivers/tee/qcomtee/shm.c b/drivers/tee/qcomtee/shm.c
new file mode 100644
index 000000000000..998aabe96434
--- /dev/null
+++ b/drivers/tee/qcomtee/shm.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/firmware/qcom/qcom_tzmem.h>
+#include <linux/mm.h>
+
+#include "qcomtee_msg.h"
+#include "qcomtee_private.h"
+
+/**
+ * define MAX_OUTBOUND_BUFFER_SIZE - Maximum size of outbound buffers.
+ *
+ * The size of outbound buffer depends on QTEE callback requests.
+ * If an invocation requires any size larger than %MAX_OUTBOUND_BUFFER_SIZE,
+ * the user should probably use some other form of shared memory with QTEE.
+ */
+#define MAX_OUTBOUND_BUFFER_SIZE SZ_4K
+
+/* Same as %MAX_OUTBOUND_BUFFER_SIZE but for inbound buffer. */
+#define MAX_INBOUND_BUFFER_SIZE SZ_4M
+
+/**
+ * qcomtee_msg_buffers_alloc() - Allocate inbound and outbound buffers.
+ * @oic: context to use for the current invocation.
+ * @u: array of arguments for the current invocation.
+ *
+ * It calculates the size of inbound and outbound buffers based on the
+ * arguments in @u. It allocates the buffers from the teedev pool.
+ *
+ * Return: On success, returns 0. On error, returns < 0.
+ */
+int qcomtee_msg_buffers_alloc(struct qcomtee_object_invoke_ctx *oic,
+			      struct qcomtee_arg *u)
+{
+	struct tee_context *ctx = oic->ctx;
+	struct tee_shm *shm;
+	size_t size;
+	int i;
+
+	/* Start offset in a message for buffer arguments. */
+	size = qcomtee_msg_buffer_args(struct qcomtee_msg_object_invoke,
+				       qcomtee_args_len(u));
+	if (size > MAX_INBOUND_BUFFER_SIZE)
+		return -EINVAL;
+
+	/* Add size of IB arguments. */
+	qcomtee_arg_for_each_input_buffer(i, u) {
+		size = size_add(size, qcomtee_msg_offset_align(u[i].b.size));
+		if (size > MAX_INBOUND_BUFFER_SIZE)
+			return -EINVAL;
+	}
+
+	/* Add size of OB arguments. */
+	qcomtee_arg_for_each_output_buffer(i, u) {
+		size = size_add(size, qcomtee_msg_offset_align(u[i].b.size));
+		if (size > MAX_INBOUND_BUFFER_SIZE)
+			return -EINVAL;
+	}
+
+	shm = tee_shm_alloc_priv_buf(ctx, size);
+	if (IS_ERR(shm))
+		return PTR_ERR(shm);
+
+	/* Allocate inbound buffer. */
+	oic->in_shm = shm;
+	shm = tee_shm_alloc_priv_buf(ctx, MAX_OUTBOUND_BUFFER_SIZE);
+	if (IS_ERR(shm)) {
+		tee_shm_free(oic->in_shm);
+
+		return PTR_ERR(shm);
+	}
+	/* Allocate outbound buffer. */
+	oic->out_shm = shm;
+
+	oic->in_msg.addr = tee_shm_get_va(oic->in_shm, 0);
+	oic->in_msg.size = tee_shm_get_size(oic->in_shm);
+	oic->out_msg.addr = tee_shm_get_va(oic->out_shm, 0);
+	oic->out_msg.size = tee_shm_get_size(oic->out_shm);
+	/* QTEE assume unused buffers are zeroed. */
+	memzero_explicit(oic->in_msg.addr, oic->in_msg.size);
+	memzero_explicit(oic->out_msg.addr, oic->out_msg.size);
+
+	return 0;
+}
+
+void qcomtee_msg_buffers_free(struct qcomtee_object_invoke_ctx *oic)
+{
+	tee_shm_free(oic->in_shm);
+	tee_shm_free(oic->out_shm);
+}
+
+/* Dynamic shared memory pool based on tee_dyn_shm_alloc_helper(). */
+
+static int qcomtee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
+				struct page **pages, size_t num_pages,
+				unsigned long start)
+{
+	return qcom_tzmem_shm_bridge_create(shm->paddr, shm->size,
+					    &shm->sec_world_id);
+}
+
+static int qcomtee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
+{
+	qcom_tzmem_shm_bridge_delete(shm->sec_world_id);
+
+	return 0;
+}
+
+static int pool_op_alloc(struct tee_shm_pool *pool, struct tee_shm *shm,
+			 size_t size, size_t align)
+{
+	if (!(shm->flags & TEE_SHM_PRIV))
+		return -ENOMEM;
+
+	return tee_dyn_shm_alloc_helper(shm, size, align, qcomtee_shm_register);
+}
+
+static void pool_op_free(struct tee_shm_pool *pool, struct tee_shm *shm)
+{
+	tee_dyn_shm_free_helper(shm, qcomtee_shm_unregister);
+}
+
+static void pool_op_destroy_pool(struct tee_shm_pool *pool)
+{
+	kfree(pool);
+}
+
+static const struct tee_shm_pool_ops pool_ops = {
+	.alloc = pool_op_alloc,
+	.free = pool_op_free,
+	.destroy_pool = pool_op_destroy_pool,
+};
+
+struct tee_shm_pool *qcomtee_shm_pool_alloc(void)
+{
+	struct tee_shm_pool *pool;
+
+	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
+	if (!pool)
+		return ERR_PTR(-ENOMEM);
+
+	pool->ops = &pool_ops;
+
+	return pool;
+}
diff --git a/drivers/tee/qcomtee/user_obj.c b/drivers/tee/qcomtee/user_obj.c
new file mode 100644
index 000000000000..95d22e720de7
--- /dev/null
+++ b/drivers/tee/qcomtee/user_obj.c
@@ -0,0 +1,710 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include "qcomtee_private.h"
+
+/**
+ * DOC: User Objects aka Supplicants
+ *
+ * Any userspace process with access to the TEE device file can behave as a
+ * supplicant by creating a user object. Any TEE parameter of type OBJREF with
+ * %QCOMTEE_OBJREF_FLAG_USER flag set is considered a user object.
+ *
+ * A supplicant uses qcomtee_user_object_select() (i.e. TEE_IOC_SUPPL_RECV) to
+ * receive a QTEE user object request and qcomtee_user_object_submit()
+ * (i.e. TEE_IOC_SUPPL_SEND) to submit a response. QTEE expects to receive the
+ * response, including OB and OO in a specific order in the message; parameters
+ * submitted with qcomtee_user_object_submit() should maintain this order.
+ */
+
+/**
+ * struct qcomtee_user_object - User object.
+ * @object: &struct qcomtee_object representing this user object.
+ * @ctx: context for which the user object is defined.
+ * @object_id: object ID in @ctx.
+ * @nor: notify on release.
+ *
+ * Any object managed in userspace is represented by this struct.
+ * If @nor is set, a notification message is sent back to userspace
+ * upon release.
+ */
+struct qcomtee_user_object {
+	struct qcomtee_object object;
+	struct tee_context *ctx;
+	u64 object_id;
+	bool nor;
+};
+
+#define to_qcomtee_user_object(o) \
+	container_of((o), struct qcomtee_user_object, object)
+
+static struct qcomtee_object_operations qcomtee_user_object_ops;
+
+/* Is it a user object? */
+int is_qcomtee_user_object(struct qcomtee_object *object)
+{
+	return object != NULL_QCOMTEE_OBJECT &&
+	       typeof_qcomtee_object(object) == QCOMTEE_OBJECT_TYPE_CB &&
+	       object->ops == &qcomtee_user_object_ops;
+}
+
+/* Set the user object's 'notify on release' flag. */
+void qcomtee_user_object_set_notify(struct qcomtee_object *object, bool notify)
+{
+	if (is_qcomtee_user_object(object))
+		to_qcomtee_user_object(object)->nor = notify;
+}
+
+/* Supplicant Requests: */
+
+/**
+ * enum qcomtee_req_state - Current state of request.
+ * @QCOMTEE_REQ_QUEUED: Request is waiting for supplicant.
+ * @QCOMTEE_REQ_PROCESSING: Request has been picked by the supplicant.
+ * @QCOMTEE_REQ_PROCESSED: Response has been submitted for the request.
+ */
+enum qcomtee_req_state {
+	QCOMTEE_REQ_QUEUED = 1,
+	QCOMTEE_REQ_PROCESSING,
+	QCOMTEE_REQ_PROCESSED,
+};
+
+/* User requests sent to supplicants. */
+struct qcomtee_ureq {
+	enum qcomtee_req_state state;
+
+	/* User Request: */
+	int req_id;
+	u64 object_id;
+	u32 op;
+	struct qcomtee_arg *args;
+	int errno;
+
+	struct list_head node;
+	struct completion c; /* Completion for whoever wait. */
+};
+
+/*
+ * Placeholder for a PROCESSING request in qcomtee_context.reqs_idr.
+ *
+ * If the thread that calls qcomtee_object_invoke() dies and the supplicant
+ * is processing the request, we replace the entry in qcomtee_context.reqs_idr
+ * with empty_ureq. This ensures that (1) the req_id remains busy and is not
+ * reused, and (2) the supplicant fails to submit the response and performs
+ * the necessary rollback.
+ */
+static struct qcomtee_ureq empty_ureq = { .state = QCOMTEE_REQ_PROCESSING };
+
+/* Enqueue a user request for a context and assign a request ID. */
+static int ureq_enqueue(struct qcomtee_context_data *ctxdata,
+			struct qcomtee_ureq *ureq)
+{
+	int ret;
+
+	guard(mutex)(&ctxdata->reqs_lock);
+	/* Supplicant is dying. */
+	if (ctxdata->released)
+		return -ENODEV;
+
+	/* Allocate an ID and queue the request. */
+	ret = idr_alloc(&ctxdata->reqs_idr, ureq, 0, 0, GFP_KERNEL);
+	if (ret < 0)
+		return ret;
+
+	ureq->req_id = ret;
+	ureq->state = QCOMTEE_REQ_QUEUED;
+	list_add_tail(&ureq->node, &ctxdata->reqs_list);
+
+	return 0;
+}
+
+/**
+ * ureq_dequeue() - Dequeue a user request from a context.
+ * @ctxdata: context data for a context to dequeue the request.
+ * @req_id: ID of the request to be dequeued.
+ *
+ * It dequeues a user request and releases its request ID.
+ *
+ * Context: The caller should hold &qcomtee_context_data->reqs_lock.
+ * Return: Returns the user request associated with this ID; otherwise, NULL.
+ */
+static struct qcomtee_ureq *ureq_dequeue(struct qcomtee_context_data *ctxdata,
+					 int req_id)
+{
+	struct qcomtee_ureq *ureq;
+
+	ureq = idr_remove(&ctxdata->reqs_idr, req_id);
+	if (ureq == &empty_ureq || !ureq)
+		return NULL;
+
+	list_del(&ureq->node);
+
+	return ureq;
+}
+
+/**
+ * ureq_replace() - Replace a user request.
+ * @ctxdata: context data for a context to replace the request.
+ * @ureq: request to be replaced.
+ * @ureq_new: request to replace it with.
+ *
+ * Context: The caller should hold &qcomtee_context_data->reqs_lock.
+ */
+static void ureq_replace(struct qcomtee_context_data *ctxdata,
+			 struct qcomtee_ureq *ureq,
+			 struct qcomtee_ureq *ureq_new)
+{
+	idr_replace(&ctxdata->reqs_idr, ureq_new, ureq->req_id);
+	/* ureq does not have a valid ID anymore; remove it from the queue. */
+	list_del(&ureq->node);
+}
+
+/**
+ * ureq_select() - Select the next request in a context.
+ * @ctxdata: context data for a context to pop a request.
+ * @ubuf_size: size of the available buffer for UBUF parameters.
+ * @num_params: number of entries for the TEE parameter array.
+ *
+ * It checks if @num_params is large enough to fit the next request arguments.
+ * It checks if @ubuf_size is large enough to fit IB buffer arguments.
+ *
+ * Context: The caller should hold &qcomtee_context_data->reqs_lock.
+ * Return: On success, returns a request;
+ *         on failure, returns NULL and ERR_PTR.
+ */
+static struct qcomtee_ureq *ureq_select(struct qcomtee_context_data *ctxdata,
+					size_t ubuf_size, int num_params)
+{
+	struct qcomtee_ureq *req, *ureq = NULL;
+	struct qcomtee_arg *u;
+	int i;
+
+	/* Find the a queued request. */
+	list_for_each_entry(req, &ctxdata->reqs_list, node) {
+		if (req->state == QCOMTEE_REQ_QUEUED) {
+			ureq = req;
+			break;
+		}
+	}
+
+	if (!ureq)
+		return NULL;
+
+	u = ureq->args;
+	/* (1) Is there enough TEE parameters? */
+	if (num_params < qcomtee_args_len(u))
+		return ERR_PTR(-EINVAL);
+	/* (2) Is there enough space to pass input buffers? */
+	qcomtee_arg_for_each_input_buffer(i, u) {
+		ubuf_size = size_sub(ubuf_size, u[i].b.size);
+		if (ubuf_size == SIZE_MAX)
+			return ERR_PTR(-EINVAL);
+
+		ubuf_size = round_down(ubuf_size, 8);
+	}
+
+	return ureq;
+}
+
+/* This is called when there are no more users for the ctxdata. */
+void qcomtee_requests_destroy(struct qcomtee_context_data *ctxdata)
+{
+	struct qcomtee_ureq *req, *ureq;
+
+	guard(mutex)(&ctxdata->reqs_lock);
+	/* So ureq_enqueue() refuses new requests from QTEE. */
+	ctxdata->released = 1;
+
+	list_for_each_entry_safe(ureq, req, &ctxdata->reqs_list, node) {
+		ureq_dequeue(ctxdata, ureq->req_id);
+
+		/*
+		 * Terminate requests.
+		 * Depending on who enqueues the ureq, there may be someone
+		 * waiting for the response or not:
+		 */
+		if (ureq->op != QCOMTEE_MSG_OBJECT_OP_RELEASE) {
+			/* (1) enqueued by qcomtee_user_object_dispatch(). */
+			ureq->state = QCOMTEE_REQ_PROCESSED;
+			ureq->errno = -ENODEV;
+
+			complete(&ureq->c);
+		} else {
+			/* (2) enqueued by qcomtee_user_object_release(). */
+			kfree(ureq);
+		}
+	}
+}
+
+/* User Object API. */
+
+/* User object dispatcher. */
+static int qcomtee_user_object_dispatch(struct qcomtee_object_invoke_ctx *oic,
+					struct qcomtee_object *object, u32 op,
+					struct qcomtee_arg *args)
+{
+	struct qcomtee_user_object *uo = to_qcomtee_user_object(object);
+	struct qcomtee_context_data *ctxdata = uo->ctx->data;
+	struct qcomtee_ureq *ureq __free(kfree) = NULL;
+	int errno;
+
+	ureq = kzalloc(sizeof(*ureq), GFP_KERNEL);
+	if (!ureq)
+		return -ENOMEM;
+
+	init_completion(&ureq->c);
+	ureq->object_id = uo->object_id;
+	ureq->op = op;
+	ureq->args = args;
+
+	/* Queue the request. */
+	if (ureq_enqueue(ctxdata, ureq))
+		return -ENODEV;
+
+	/* Wakeup supplicant to process it. */
+	complete(&ctxdata->req_c);
+
+	/*
+	 * Wait for the supplicant to process the request.
+	 *
+	 * The supplicant is expected to process the request in a timely manner.
+	 * We wait as KILLABLE in case the supplicant and invoke thread are
+	 * both running from the same user process; otherwise, the process
+	 * will be stuck on a fatal signal.
+	 */
+	if (!wait_for_completion_state(&ureq->c,
+				       TASK_KILLABLE | TASK_FREEZABLE)) {
+		errno = ureq->errno;
+		/* On success, notify() frees the request. */
+		if (!errno)
+			oic->data = no_free_ptr(ureq);
+	} else {
+		enum qcomtee_req_state prev_state;
+
+		errno = -ENODEV;
+
+		scoped_guard(mutex, &ctxdata->reqs_lock) {
+			prev_state = ureq->state;
+
+			/* Replace with empty_ureq to keep req_id reserved. */
+			if (prev_state == QCOMTEE_REQ_PROCESSING)
+				ureq_replace(ctxdata, ureq, &empty_ureq);
+
+			/* Remove as supplicant has never seen this request. */
+			else if (prev_state == QCOMTEE_REQ_QUEUED)
+				ureq_dequeue(ctxdata, ureq->req_id);
+		}
+
+		/* Supplicant did some work, we should not discard it. */
+		if (prev_state == QCOMTEE_REQ_PROCESSED) {
+			errno = ureq->errno;
+			/* On success, notify() frees the request. */
+			if (!errno)
+				oic->data = no_free_ptr(ureq);
+		}
+	}
+
+	return errno;
+}
+
+/* This is called after submitting the dispatcher response. */
+static void qcomtee_user_object_notify(struct qcomtee_object_invoke_ctx *oic,
+				       struct qcomtee_object *unused_object,
+				       int err)
+{
+	struct qcomtee_ureq *ureq = oic->data;
+	struct qcomtee_arg *u = ureq->args;
+	int i;
+
+	qcomtee_arg_for_each_output_object(i, u) {
+		/*
+		 * If err, there was a transport issue, and QTEE did not
+		 * receive the response for the dispatcher. Release the callback
+		 * object created for QTEE, in addition to the copies of
+		 * objects kept for the drivers.
+		 */
+		if (err &&
+		    (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB))
+			qcomtee_object_put(u[i].o);
+		qcomtee_object_put(u[i].o);
+	}
+
+	kfree(ureq);
+}
+
+static void qcomtee_user_object_release(struct qcomtee_object *object)
+{
+	struct qcomtee_user_object *uo = to_qcomtee_user_object(object);
+	struct qcomtee_context_data *ctxdata = uo->ctx->data;
+	struct qcomtee_ureq *ureq;
+
+	/* RELEASE does not require any argument. */
+	static struct qcomtee_arg args[] = { { .type = QCOMTEE_ARG_TYPE_INV } };
+
+	if (!uo->nor)
+		goto out_no_notify;
+
+	ureq = kzalloc(sizeof(*ureq), GFP_KERNEL);
+	if (!ureq)
+		goto out_no_notify;
+
+	/* QUEUE a release request: */
+	ureq->object_id = uo->object_id;
+	ureq->op = QCOMTEE_MSG_OBJECT_OP_RELEASE;
+	ureq->args = args;
+	if (ureq_enqueue(ctxdata, ureq)) {
+		kfree(ureq);
+		/* Ignore the notification if it cannot be queued. */
+		goto out_no_notify;
+	}
+
+	complete(&ctxdata->req_c);
+
+out_no_notify:
+	teedev_ctx_put(uo->ctx);
+	kfree(uo);
+}
+
+static struct qcomtee_object_operations qcomtee_user_object_ops = {
+	.release = qcomtee_user_object_release,
+	.notify = qcomtee_user_object_notify,
+	.dispatch = qcomtee_user_object_dispatch,
+};
+
+/**
+ * qcomtee_user_param_to_object() - OBJREF parameter to &struct qcomtee_object.
+ * @object: object returned.
+ * @param: TEE parameter.
+ * @ctx: context in which the conversion should happen.
+ *
+ * @param is an OBJREF with %QCOMTEE_OBJREF_FLAG_USER flags.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_user_param_to_object(struct qcomtee_object **object,
+				 struct tee_param *param,
+				 struct tee_context *ctx)
+{
+	struct qcomtee_user_object *user_object __free(kfree) = NULL;
+	int err;
+
+	user_object = kzalloc(sizeof(*user_object), GFP_KERNEL);
+	if (!user_object)
+		return -ENOMEM;
+
+	user_object->ctx = ctx;
+	user_object->object_id = param->u.objref.id;
+	/* By default, always notify userspace upon release. */
+	user_object->nor = true;
+	err = qcomtee_object_user_init(&user_object->object,
+				       QCOMTEE_OBJECT_TYPE_CB,
+				       &qcomtee_user_object_ops, "uo-%lu",
+				       param->u.objref.id);
+	if (err)
+		return err;
+
+	teedev_ctx_get(ctx);
+
+	*object = &no_free_ptr(user_object)->object;
+
+	return 0;
+}
+
+/* Reverse what qcomtee_user_param_to_object() does. */
+int qcomtee_user_param_from_object(struct tee_param *param,
+				   struct qcomtee_object *object,
+				   struct tee_context *ctx)
+{
+	struct qcomtee_user_object *uo;
+
+	uo = to_qcomtee_user_object(object);
+	/* Ensure the object is in the same context as the caller. */
+	if (uo->ctx != ctx)
+		return -EINVAL;
+
+	param->u.objref.id = uo->object_id;
+	param->u.objref.flags = QCOMTEE_OBJREF_FLAG_USER;
+
+	/* User objects are valid in userspace; do not keep a copy. */
+	qcomtee_object_put(object);
+
+	return 0;
+}
+
+/**
+ * qcomtee_cb_params_from_args() - Convert QTEE arguments to TEE parameters.
+ * @params: TEE parameters.
+ * @u: QTEE arguments.
+ * @num_params: number of elements in the parameter array.
+ * @ubuf_addr: user buffer for arguments of type %QCOMTEE_ARG_TYPE_IB.
+ * @ubuf_size: size of the user buffer.
+ * @ctx: context in which the conversion should happen.
+ *
+ * It expects @params to have enough entries for @u. Entries in @params are of
+ * %TEE_IOCTL_PARAM_ATTR_TYPE_NONE.
+ *
+ * Return: On success, returns the number of input parameters;
+ *         on failure, returns < 0.
+ */
+static int qcomtee_cb_params_from_args(struct tee_param *params,
+				       struct qcomtee_arg *u, int num_params,
+				       void __user *ubuf_addr, size_t ubuf_size,
+				       struct tee_context *ctx)
+{
+	int i, np;
+	void __user *uaddr;
+
+	qcomtee_arg_for_each(i, u) {
+		switch (u[i].type) {
+		case QCOMTEE_ARG_TYPE_IB:
+			params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT;
+
+			/* Underflow already checked in ureq_select(). */
+			ubuf_size = round_down(ubuf_size - u[i].b.size, 8);
+			uaddr = (void *__user)(ubuf_addr + ubuf_size);
+
+			params[i].u.ubuf.uaddr = uaddr;
+			params[i].u.ubuf.size = u[i].b.size;
+			if (copy_to_user(params[i].u.ubuf.uaddr, u[i].b.addr,
+					 u[i].b.size))
+				goto out_failed;
+
+			break;
+		case QCOMTEE_ARG_TYPE_OB:
+			params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT;
+			/* Let the user knows the maximum size we expect. */
+			params[i].u.ubuf.size = u[i].b.size;
+
+			break;
+		case QCOMTEE_ARG_TYPE_IO:
+			params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT;
+			if (qcomtee_objref_from_arg(&params[i], &u[i], ctx))
+				goto out_failed;
+
+			break;
+		case QCOMTEE_ARG_TYPE_OO:
+			params[i].attr =
+				TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT;
+
+			break;
+		default: /* Never get here! */
+			goto out_failed;
+		}
+	}
+
+	return i;
+
+out_failed:
+	/* Undo qcomtee_objref_from_arg(). */
+	for (np = i; np >= 0; np--) {
+		if (params[np].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT)
+			qcomtee_context_del_qtee_object(&params[np], ctx);
+	}
+
+	/* Release any IO objects not processed. */
+	for (; u[i].type; i++) {
+		if (u[i].type == QCOMTEE_ARG_TYPE_IO)
+			qcomtee_object_put(u[i].o);
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * qcomtee_cb_params_to_args() - Convert TEE parameters to QTEE arguments.
+ * @u: QTEE arguments.
+ * @params: TEE parameters.
+ * @num_params: number of elements in the parameter array.
+ * @ctx: context in which the conversion should happen.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+static int qcomtee_cb_params_to_args(struct qcomtee_arg *u,
+				     struct tee_param *params, int num_params,
+				     struct tee_context *ctx)
+{
+	int i;
+
+	qcomtee_arg_for_each(i, u) {
+		switch (u[i].type) {
+		case QCOMTEE_ARG_TYPE_IB:
+			if (params[i].attr !=
+			    TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT)
+				goto out_failed;
+
+			break;
+		case QCOMTEE_ARG_TYPE_OB:
+			if (params[i].attr !=
+			    TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT)
+				goto out_failed;
+
+			/* Client can not send more data than requested. */
+			if (params[i].u.ubuf.size > u[i].b.size)
+				goto out_failed;
+
+			if (copy_from_user(u[i].b.addr, params[i].u.ubuf.uaddr,
+					   params[i].u.ubuf.size))
+				goto out_failed;
+
+			u[i].b.size = params[i].u.ubuf.size;
+
+			break;
+		case QCOMTEE_ARG_TYPE_IO:
+			if (params[i].attr !=
+			    TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT)
+				goto out_failed;
+
+			break;
+		case QCOMTEE_ARG_TYPE_OO:
+			if (params[i].attr !=
+			    TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT)
+				goto out_failed;
+
+			if (qcomtee_objref_to_arg(&u[i], &params[i], ctx))
+				goto out_failed;
+
+			break;
+		default: /* Never get here! */
+			goto out_failed;
+		}
+	}
+
+	return 0;
+
+out_failed:
+	/* Undo qcomtee_objref_to_arg(). */
+	for (i--; i >= 0; i--) {
+		if (u[i].type != QCOMTEE_ARG_TYPE_OO)
+			continue;
+
+		qcomtee_user_object_set_notify(u[i].o, false);
+		if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)
+			qcomtee_object_put(u[i].o);
+
+		qcomtee_object_put(u[i].o);
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * qcomtee_user_object_select() - Select a request for a user object.
+ * @ctx: context to look for a user object.
+ * @params: parameters for @op.
+ * @num_params: number of elements in the parameter array.
+ * @uaddr: user buffer for output UBUF parameters.
+ * @size: size of user buffer @uaddr.
+ * @data: information for the selected request.
+ *
+ * @params is filled along with @data for the selected request.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_user_object_select(struct tee_context *ctx,
+			       struct tee_param *params, int num_params,
+			       void __user *uaddr, size_t size,
+			       struct qcomtee_user_object_request_data *data)
+{
+	struct qcomtee_context_data *ctxdata = ctx->data;
+	struct qcomtee_ureq *ureq;
+	int ret;
+
+	while (1) {
+		scoped_guard(mutex, &ctxdata->reqs_lock) {
+			ureq = ureq_select(ctxdata, size, num_params);
+			if (!ureq)
+				goto wait_for_request;
+
+			if (IS_ERR(ureq))
+				return PTR_ERR(ureq);
+
+			/* Processing the request 'QUEUED -> PROCESSING'. */
+			ureq->state = QCOMTEE_REQ_PROCESSING;
+
+			/* ''Prepare user request:'' */
+			data->id = ureq->req_id;
+			data->object_id = ureq->object_id;
+			data->op = ureq->op;
+			ret = qcomtee_cb_params_from_args(params, ureq->args,
+							  num_params, uaddr,
+							  size, ctx);
+			if (ret >= 0)
+				goto done_request;
+
+			/* Something is wrong with the request. */
+
+			ureq_dequeue(ctxdata, data->id);
+			/* Send error to QTEE. */
+			ureq->state = QCOMTEE_REQ_PROCESSED;
+			ureq->errno = ret;
+
+			complete(&ureq->c);
+		}
+
+		continue;
+wait_for_request:
+		/* Wait for a new QUEUED request. */
+		if (wait_for_completion_interruptible(&ctxdata->req_c))
+			return -ERESTARTSYS;
+	}
+
+done_request:
+	/* No one is waiting for the response. */
+	if (data->op == QCOMTEE_MSG_OBJECT_OP_RELEASE) {
+		scoped_guard(mutex, &ctxdata->reqs_lock)
+			ureq_dequeue(ctxdata, data->id);
+		kfree(ureq);
+	}
+
+	data->np = ret;
+
+	return 0;
+}
+
+/**
+ * qcomtee_user_object_submit() - Submit a response for a user object.
+ * @ctx: context to look for a user object.
+ * @params: returned parameters.
+ * @num_params: number of elements in the parameter array.
+ * @req_id: request ID for the response.
+ * @errno: result of user object invocation.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_user_object_submit(struct tee_context *ctx,
+			       struct tee_param *params, int num_params,
+			       int req_id, int errno)
+{
+	struct qcomtee_context_data *ctxdata = ctx->data;
+	struct qcomtee_ureq *ureq;
+
+	guard(mutex)(&ctxdata->reqs_lock);
+
+	ureq = ureq_dequeue(ctxdata, req_id);
+	if (!ureq)
+		return -EINVAL;
+
+	ureq->state = QCOMTEE_REQ_PROCESSED;
+
+	if (!errno)
+		ureq->errno = qcomtee_cb_params_to_args(ureq->args, params,
+							num_params, ctx);
+	else
+		ureq->errno = errno;
+
+	/* Return errno if qcomtee_cb_params_to_args() failed; otherwise 0. */
+	if (!errno && ureq->errno)
+		errno = ureq->errno;
+	else
+		errno = 0;
+
+	/* Send result to QTEE. */
+	complete(&ureq->c);
+
+	return errno;
+}
diff --git a/include/linux/firmware/qcom/qcom_tee.h b/include/linux/firmware/qcom/qcom_tee.h
new file mode 100644
index 000000000000..1d9f9bc320fe
--- /dev/null
+++ b/include/linux/firmware/qcom/qcom_tee.h
@@ -0,0 +1,302 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef __QCOM_TEE_H
+#define __QCOM_TEE_H
+
+#include <linux/completion.h>
+#include <linux/kref.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+struct qcomtee_object;
+
+/**
+ * DOC: Overview
+ *
+ * qcomtee_object provides object refcounting, ID allocation for objects hosted
+ * in the kernel, and necessary message marshaling for Qualcomm TEE (QTEE).
+ *
+ * To invoke an object in QTEE, the user calls qcomtee_object_do_invoke()
+ * while passing an instance of &struct qcomtee_object and the requested
+ * operation + arguments.
+ *
+ * After boot, QTEE provides a static object %ROOT_QCOMTEE_OBJECT (type of
+ * %QCOMTEE_OBJECT_TYPE_ROOT). The root object is invoked to pass the user's
+ * credentials and obtain other instances of &struct qcomtee_object (type of
+ * %QCOMTEE_OBJECT_TYPE_TEE) that represent services and TAs in QTEE;
+ * see &enum qcomtee_object_type.
+ *
+ * The objects received from QTEE are refcounted. So the owner of these objects
+ * can issue qcomtee_object_get() to increase the refcount and pass objects
+ * to other clients, or issue qcomtee_object_put() to decrease the refcount
+ * and release the resources in QTEE.
+ *
+ * The kernel can host services accessible to QTEE. A driver should embed
+ * an instance of &struct qcomtee_object in the struct it wants to export to
+ * QTEE (this is called a callback object). It issues qcomtee_object_user_init()
+ * to set the dispatch() operation for the callback object and set its type
+ * to %QCOMTEE_OBJECT_TYPE_CB.
+ *
+ * core.c holds an object table for callback objects. An object ID is assigned
+ * to each callback object, which is an index to the object table. QTEE uses
+ * these IDs to reference or invoke callback objects.
+ *
+ * If QTEE invokes a callback object in the kernel, the dispatch() operation is
+ * called in the context of the thread that originally called
+ * qcomtee_object_do_invoke().
+ */
+
+/**
+ * enum qcomtee_object_type - Object types.
+ * @QCOMTEE_OBJECT_TYPE_TEE: object hosted on QTEE.
+ * @QCOMTEE_OBJECT_TYPE_CB: object hosted on kernel.
+ * @QCOMTEE_OBJECT_TYPE_ROOT: 'primordial' object.
+ * @QCOMTEE_OBJECT_TYPE_NULL: NULL object.
+ *
+ * The primordial object is used for bootstrapping the IPC connection between
+ * the kernel and QTEE. It is invoked by the kernel when it wants to get a
+ * 'client env'.
+ */
+enum qcomtee_object_type {
+	QCOMTEE_OBJECT_TYPE_TEE,
+	QCOMTEE_OBJECT_TYPE_CB,
+	QCOMTEE_OBJECT_TYPE_ROOT,
+	QCOMTEE_OBJECT_TYPE_NULL,
+};
+
+/**
+ * enum qcomtee_arg_type - Type of QTEE argument.
+ * @QCOMTEE_ARG_TYPE_INV: invalid type.
+ * @QCOMTEE_ARG_TYPE_OB: output buffer (OB).
+ * @QCOMTEE_ARG_TYPE_OO: output object (OO).
+ * @QCOMTEE_ARG_TYPE_IB: input buffer (IB).
+ * @QCOMTEE_ARG_TYPE_IO: input object (IO).
+ *
+ * Use the invalid type to specify the end of the argument array.
+ */
+enum qcomtee_arg_type {
+	QCOMTEE_ARG_TYPE_INV = 0,
+	QCOMTEE_ARG_TYPE_OB,
+	QCOMTEE_ARG_TYPE_OO,
+	QCOMTEE_ARG_TYPE_IB,
+	QCOMTEE_ARG_TYPE_IO,
+	QCOMTEE_ARG_TYPE_NR,
+};
+
+/**
+ * define QCOMTEE_ARGS_PER_TYPE - Maximum arguments of a specific type.
+ *
+ * The QTEE transport protocol limits the maximum number of arguments of
+ * a specific type (i.e., IB, OB, IO, and OO).
+ */
+#define QCOMTEE_ARGS_PER_TYPE 16
+
+/* Maximum arguments that can fit in a QTEE message, ignoring the type. */
+#define QCOMTEE_ARGS_MAX (QCOMTEE_ARGS_PER_TYPE * (QCOMTEE_ARG_TYPE_NR - 1))
+
+struct qcomtee_buffer {
+	union {
+		void *addr;
+		void __user *uaddr;
+	};
+	size_t size;
+};
+
+/**
+ * struct qcomtee_arg - Argument for QTEE object invocation.
+ * @type: type of argument as &enum qcomtee_arg_type.
+ * @flags: extra flags.
+ * @b: address and size if the type of argument is a buffer.
+ * @o: object instance if the type of argument is an object.
+ *
+ * &qcomtee_arg.flags only accepts %QCOMTEE_ARG_FLAGS_UADDR for now, which
+ * states that &qcomtee_arg.b contains a userspace address in uaddr.
+ */
+struct qcomtee_arg {
+	enum qcomtee_arg_type type;
+/* 'b.uaddr' holds a __user address. */
+#define QCOMTEE_ARG_FLAGS_UADDR BIT(0)
+	unsigned int flags;
+	union {
+		struct qcomtee_buffer b;
+		struct qcomtee_object *o;
+	};
+};
+
+static inline int qcomtee_args_len(struct qcomtee_arg *args)
+{
+	int i = 0;
+
+	while (args[i].type != QCOMTEE_ARG_TYPE_INV)
+		i++;
+	return i;
+}
+
+/* Context is busy (callback is in progress). */
+#define QCOMTEE_OIC_FLAG_BUSY BIT(1)
+/* Context needs to notify the current object. */
+#define QCOMTEE_OIC_FLAG_NOTIFY BIT(2)
+/* Context has shared state with QTEE. */
+#define QCOMTEE_OIC_FLAG_SHARED BIT(3)
+
+struct qcomtee_object_invoke_ctx {
+	/* TEE context for this invocation. */
+	struct tee_context *ctx;
+	unsigned long flags;
+	int errno;
+
+	/* Current object invoked in this callback context. */
+	struct qcomtee_object *object;
+
+	/* Dispatcher argument array (+1 for ending QCOMTEE_ARG_TYPE_INV). */
+	struct qcomtee_arg u[QCOMTEE_ARGS_MAX + 1];
+
+	/* Inbound and Outbound buffers shared with QTEE. */
+	struct qcomtee_buffer in_msg; /* Inbound buffer.  */
+	struct qcomtee_buffer out_msg; /* Outbound buffer. */
+	struct tee_shm *in_shm; /* TEE shm allocated for inbound buffer. */
+	struct tee_shm *out_shm; /* TEE shm allocated for outbound buffer. */
+
+	/* Extra data attached to this context. */
+	void *data;
+};
+
+static inline struct qcomtee_object_invoke_ctx *
+qcomtee_object_invoke_ctx_alloc(struct tee_context *ctx)
+{
+	struct qcomtee_object_invoke_ctx *oic;
+
+	oic = kzalloc(sizeof(*oic), GFP_KERNEL);
+	if (oic)
+		oic->ctx = ctx;
+	return oic;
+}
+
+/**
+ * qcomtee_object_do_invoke() - Submit an invocation for an object.
+ * @oic: context to use for the current invocation.
+ * @object: object being invoked.
+ * @op: requested operation on the object.
+ * @u: array of arguments for the current invocation.
+ * @result: result returned from QTEE.
+ *
+ * The caller is responsible for keeping track of the refcount for each object,
+ * including @object. On return, the caller loses ownership of all input
+ * objects of type %QCOMTEE_OBJECT_TYPE_CB.
+ *
+ * @object can be of %QCOMTEE_OBJECT_TYPE_ROOT or %QCOMTEE_OBJECT_TYPE_TEE.
+ *
+ * Return: On success, returns 0. On error, returns -EAGAIN if invocation
+ * failed and the user may retry the invocation, -ENODEV on fatal failure.
+ */
+int qcomtee_object_do_invoke(struct qcomtee_object_invoke_ctx *oic,
+			     struct qcomtee_object *object, u32 op,
+			     struct qcomtee_arg *u, int *result);
+
+/**
+ * struct qcomtee_object_operations - Callback object operations.
+ * @release: release the object if QTEE is not using it.
+ * @dispatch: dispatch the operation requested by QTEE.
+ * @notify: report the status of any pending response submitted by @dispatch.
+ */
+struct qcomtee_object_operations {
+	void (*release)(struct qcomtee_object *object);
+	int (*dispatch)(struct qcomtee_object_invoke_ctx *oic,
+			struct qcomtee_object *object, u32 op,
+			struct qcomtee_arg *args);
+	void (*notify)(struct qcomtee_object_invoke_ctx *oic,
+		       struct qcomtee_object *object, int err);
+};
+
+/**
+ * struct qcomtee_object - QTEE or kernel object.
+ * @name: object name.
+ * @refcount: reference counter.
+ * @object_type: object type as &enum qcomtee_object_type.
+ * @info: extra information for the object.
+ * @ops: callback operations for objects of type %QCOMTEE_OBJECT_TYPE_CB.
+ * @work: work for async operations on the object.
+ *
+ * @work is used for releasing objects of %QCOMTEE_OBJECT_TYPE_TEE type.
+ */
+struct qcomtee_object {
+	const char *name;
+	struct kref refcount;
+
+	enum qcomtee_object_type object_type;
+	struct object_info {
+		unsigned long qtee_id;
+		/* TEE context for QTEE object async requests. */
+		struct tee_context *qcomtee_async_ctx;
+	} info;
+
+	struct qcomtee_object_operations *ops;
+	struct work_struct work;
+};
+
+/* Static instances of qcomtee_object objects. */
+#define NULL_QCOMTEE_OBJECT ((struct qcomtee_object *)(0))
+extern struct qcomtee_object qcomtee_object_root;
+#define ROOT_QCOMTEE_OBJECT (&qcomtee_object_root)
+
+static inline enum qcomtee_object_type
+typeof_qcomtee_object(struct qcomtee_object *object)
+{
+	if (object == NULL_QCOMTEE_OBJECT)
+		return QCOMTEE_OBJECT_TYPE_NULL;
+	return object->object_type;
+}
+
+static inline const char *qcomtee_object_name(struct qcomtee_object *object)
+{
+	if (object == NULL_QCOMTEE_OBJECT)
+		return "null";
+
+	if (!object->name)
+		return "no-name";
+	return object->name;
+}
+
+/**
+ * qcomtee_object_user_init() - Initialize an object for the user.
+ * @object: object to initialize.
+ * @ot: type of object as &enum qcomtee_object_type.
+ * @ops: instance of callbacks.
+ * @fmt: name assigned to the object.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcomtee_object_user_init(struct qcomtee_object *object,
+			     enum qcomtee_object_type ot,
+			     struct qcomtee_object_operations *ops,
+			     const char *fmt, ...);
+
+/* Object release is RCU protected. */
+int qcomtee_object_get(struct qcomtee_object *object);
+void qcomtee_object_put(struct qcomtee_object *object);
+
+#define qcomtee_arg_for_each(i, args) \
+	for (i = 0; args[i].type != QCOMTEE_ARG_TYPE_INV; i++)
+
+/* Next argument of type @type after index @i. */
+int qcomtee_next_arg_type(struct qcomtee_arg *u, int i,
+			  enum qcomtee_arg_type type);
+
+/* Iterate over argument of given type. */
+#define qcomtee_arg_for_each_type(i, args, at)              \
+	for (i = 0, i = qcomtee_next_arg_type(args, i, at); \
+	     args[i].type != QCOMTEE_ARG_TYPE_INV;          \
+	     i++, i = qcomtee_next_arg_type(args, i, at))
+
+#define qcomtee_arg_for_each_input_buffer(i, args) \
+	qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_IB)
+#define qcomtee_arg_for_each_output_buffer(i, args) \
+	qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_OB)
+#define qcomtee_arg_for_each_input_object(i, args) \
+	qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_IO)
+#define qcomtee_arg_for_each_output_object(i, args) \
+	qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_OO)
+
+#endif /* __QCOM_TEE_H */
diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index 8642ce7e4772..0efb2835d6dc 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -59,6 +59,7 @@
 #define TEE_IMPL_ID_OPTEE	1
 #define TEE_IMPL_ID_AMDTEE	2
 #define TEE_IMPL_ID_TSTEE	3
+#define TEE_IMPL_ID_QTEE	4
 
 /*
  * OP-TEE specific capabilities

-- 
2.34.1
Re: [PATCH v3 08/11] tee: add Qualcomm TEE driver
Posted by Jens Wiklander 8 months, 1 week ago
Hi Amirreza,

On Fri, Mar 28, 2025 at 3:48 AM Amirreza Zarrabi
<amirreza.zarrabi@oss.qualcomm.com> wrote:
>
> Introduce qcomtee_object, which represents an object in both QTEE and
> the kernel. QTEE clients can invoke an instance of qcomtee_object to
> access QTEE services. If this invocation produces a new object in QTEE,
> an instance of qcomtee_object will be returned.
>
> Similarly, QTEE can request services from the kernel by issuing a callback
> request, which invokes an instance of qcomtee_object in the kernel.
> Any subsystem that exposes a service to QTEE should allocate and initialize
> an instance of qcomtee_object with a dispatcher callback that is called
> when the object is invoked.
>
> Implement initial support for exporting qcomtee_object to userspace
> and QTEE, enabling the invocation of objects hosted in QTEE and userspace
> through the TEE subsystem.
>
> Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
> ---
>  drivers/tee/Kconfig                    |   1 +
>  drivers/tee/Makefile                   |   1 +
>  drivers/tee/qcomtee/Kconfig            |  10 +
>  drivers/tee/qcomtee/Makefile           |   9 +
>  drivers/tee/qcomtee/async.c            | 160 +++++++
>  drivers/tee/qcomtee/call.c             | 753 +++++++++++++++++++++++++++++++
>  drivers/tee/qcomtee/core.c             | 801 +++++++++++++++++++++++++++++++++
>  drivers/tee/qcomtee/qcom_scm.c         |  38 ++
>  drivers/tee/qcomtee/qcomtee_msg.h      | 239 ++++++++++
>  drivers/tee/qcomtee/qcomtee_private.h  | 222 +++++++++
>  drivers/tee/qcomtee/release.c          |  48 ++
>  drivers/tee/qcomtee/shm.c              | 149 ++++++
>  drivers/tee/qcomtee/user_obj.c         | 710 +++++++++++++++++++++++++++++
>  include/linux/firmware/qcom/qcom_tee.h | 302 +++++++++++++
>  include/uapi/linux/tee.h               |   1 +
>  15 files changed, 3444 insertions(+)
>
> diff --git a/drivers/tee/Kconfig b/drivers/tee/Kconfig
> index 61b507c18780..3a995d7f0d74 100644
> --- a/drivers/tee/Kconfig
> +++ b/drivers/tee/Kconfig
> @@ -16,5 +16,6 @@ if TEE
>  source "drivers/tee/optee/Kconfig"
>  source "drivers/tee/amdtee/Kconfig"
>  source "drivers/tee/tstee/Kconfig"
> +source "drivers/tee/qcomtee/Kconfig"
>
>  endif
> diff --git a/drivers/tee/Makefile b/drivers/tee/Makefile
> index 5488cba30bd2..74e987f8f7ea 100644
> --- a/drivers/tee/Makefile
> +++ b/drivers/tee/Makefile
> @@ -6,3 +6,4 @@ tee-objs += tee_shm_pool.o
>  obj-$(CONFIG_OPTEE) += optee/
>  obj-$(CONFIG_AMDTEE) += amdtee/
>  obj-$(CONFIG_ARM_TSTEE) += tstee/
> +obj-$(CONFIG_QCOMTEE) += qcomtee/
> diff --git a/drivers/tee/qcomtee/Kconfig b/drivers/tee/qcomtee/Kconfig
> new file mode 100644
> index 000000000000..d180a6d07d33
> --- /dev/null
> +++ b/drivers/tee/qcomtee/Kconfig
> @@ -0,0 +1,10 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +# Qualcomm Trusted Execution Environment Configuration
> +config QCOMTEE
> +       tristate "Qualcomm TEE Support"
> +       select QCOM_SCM
> +       help
> +         This option enables the Qualcomm Trusted Execution Environment (QTEE)
> +         driver. It provides an API to access services offered by QTEE and any
> +         loaded Trusted Applications (TAs), as well as exporting kernel
> +         services to QTEE.
> diff --git a/drivers/tee/qcomtee/Makefile b/drivers/tee/qcomtee/Makefile
> new file mode 100644
> index 000000000000..1b14b943e5f5
> --- /dev/null
> +++ b/drivers/tee/qcomtee/Makefile
> @@ -0,0 +1,9 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +obj-$(CONFIG_QCOMTEE) += qcomtee.o
> +qcomtee-objs += async.o
> +qcomtee-objs += call.o
> +qcomtee-objs += core.o
> +qcomtee-objs += qcom_scm.o
> +qcomtee-objs += release.o
> +qcomtee-objs += shm.o
> +qcomtee-objs += user_obj.o
> diff --git a/drivers/tee/qcomtee/async.c b/drivers/tee/qcomtee/async.c
> new file mode 100644
> index 000000000000..4c880c3441a2
> --- /dev/null
> +++ b/drivers/tee/qcomtee/async.c
> @@ -0,0 +1,160 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include "qcomtee_private.h"
> +#include "qcomtee_msg.h"
> +
> +#define QCOMTEE_ASYNC_VERSION_1_0 0x00010000U /* Maj: 0x0001, Min: 0x0000. */
> +#define QCOMTEE_ASYNC_VERSION_1_1 0x00010001U /* Maj: 0x0001, Min: 0x0001. */
> +#define QCOMTEE_ASYNC_VERSION_1_2 0x00010002U /* Maj: 0x0001, Min: 0x0002. */
> +#define QCOMTEE_ASYNC_VERSION QCOMTEE_ASYNC_VERSION_1_2 /* Current Version. */
> +
> +#define QCOMTEE_ASYNC_VERSION_MAJOR(n) upper_16_bits(n)
> +#define QCOMTEE_ASYNC_VERSION_MINOR(n) lower_16_bits(n)
> +
> +/**
> + * struct qcomtee_async_msg_hdr - Asynchronous message header format.
> + * @version: current async protocol version of the remote endpoint.
> + * @op: async operation.
> + *
> + * @version specifies the endpoint's (QTEE or driver) supported async protocol.
> + * For example, if QTEE sets @version to %QCOMTEE_ASYNC_VERSION_1_1, QTEE
> + * handles operations supported in %QCOMTEE_ASYNC_VERSION_1_1 or
> + * %QCOMTEE_ASYNC_VERSION_1_0. @op determines the message format.
> + */
> +struct qcomtee_async_msg_hdr {
> +       u32 version;
> +       u32 op;
> +};
> +
> +/* Size of an empty async message. */
> +#define QCOMTEE_ASYNC_MSG_ZERO sizeof(struct qcomtee_async_msg_hdr)
> +
> +/**
> + * struct qcomtee_async_release_msg - Release asynchronous message.
> + * @hdr: message header as &struct qcomtee_async_msg_hdr.
> + * @counts: number of objects in @object_ids.
> + * @object_ids: array of object IDs that should be released.
> + *
> + * Available in Maj = 0x0001, Min >= 0x0000.
> + */
> +struct qcomtee_async_release_msg {
> +       struct qcomtee_async_msg_hdr hdr;
> +       u32 counts;
> +       u32 object_ids[] __counted_by(counts);
> +};
> +
> +/**
> + * qcomtee_get_async_buffer() - Get the start of the asynchronous message.
> + * @oic: context used for the current invocation.
> + * @async_buffer: return buffer to extract from or fill in async messages.
> + *
> + * If @oic is used for direct object invocation, the whole outbound buffer
> + * is available for the async message. If @oic is used for a callback request,
> + * the tail of the outbound buffer (after the callback request message) is
> + * available for the async message.
> + *
> + * The start of the async buffer is aligned, see qcomtee_msg_offset_align().
> + */
> +static void qcomtee_get_async_buffer(struct qcomtee_object_invoke_ctx *oic,
> +                                    struct qcomtee_buffer *async_buffer)
> +{
> +       struct qcomtee_msg_callback *msg;
> +       unsigned int offset;
> +       int i;
> +
> +       if (!(oic->flags & QCOMTEE_OIC_FLAG_BUSY)) {
> +               /* The outbound buffer is empty. Using the whole buffer. */
> +               offset = 0;
> +       } else {
> +               msg = (struct qcomtee_msg_callback *)oic->out_msg.addr;
> +
> +               /* Start offset in a message for buffer arguments. */
> +               offset = qcomtee_msg_buffer_args(struct qcomtee_msg_callback,
> +                                                qcomtee_msg_args(msg));
> +
> +               /* Add size of IB arguments. */
> +               qcomtee_msg_for_each_input_buffer(i, msg)
> +                       offset += qcomtee_msg_offset_align(msg->args[i].b.size);
> +
> +               /* Add size of OB arguments. */
> +               qcomtee_msg_for_each_output_buffer(i, msg)
> +                       offset += qcomtee_msg_offset_align(msg->args[i].b.size);
> +       }
> +
> +       async_buffer->addr = oic->out_msg.addr + offset;
> +       async_buffer->size = oic->out_msg.size - offset;
> +}
> +
> +/**
> + * async_release() - Process QTEE async release requests.
> + * @oic: context used for the current invocation.
> + * @msg: async message for object release.
> + * @size: size of the async buffer available.
> + *
> + * Return: Size of the outbound buffer used when processing @msg.
> + */
> +static size_t async_release(struct qcomtee_object_invoke_ctx *oic,
> +                           struct qcomtee_async_msg_hdr *async_msg,
> +                           size_t size)
> +{
> +       struct qcomtee_async_release_msg *msg;
> +       struct qcomtee_object *object;
> +       int i;
> +
> +       msg = (struct qcomtee_async_release_msg *)async_msg;
> +
> +       for (i = 0; i < msg->counts; i++) {
> +               object = qcomtee_idx_erase(msg->object_ids[i]);
> +               qcomtee_object_put(object);
> +       }
> +
> +       return struct_size(msg, object_ids, msg->counts);
> +}
> +
> +/**
> + * qcomtee_fetch_async_reqs() - Fetch and process asynchronous messages.
> + * @oic: context used for the current invocation.
> + *
> + * Calls handlers to process the requested operations in the async message.
> + * Currently, only supports async release requests.
> + */
> +void qcomtee_fetch_async_reqs(struct qcomtee_object_invoke_ctx *oic)
> +{
> +       struct qcomtee_async_msg_hdr *async_msg;
> +       struct qcomtee_buffer async_buffer;
> +       size_t consumed, used = 0;
> +
> +       qcomtee_get_async_buffer(oic, &async_buffer);
> +
> +       while (async_buffer.size - used > QCOMTEE_ASYNC_MSG_ZERO) {
> +               async_msg = (struct qcomtee_async_msg_hdr *)(async_buffer.addr +
> +                                                            used);
> +
> +               if (QCOMTEE_ASYNC_VERSION_MAJOR(async_msg->version) !=
> +                   QCOMTEE_ASYNC_VERSION_MAJOR(QCOMTEE_ASYNC_VERSION))
> +                       goto out;
> +
> +               switch (async_msg->op) {
> +               case QCOMTEE_MSG_OBJECT_OP_RELEASE:
> +                       consumed = async_release(oic, async_msg,
> +                                                async_buffer.size - used);
> +                       break;
> +               default:
> +                       goto out;
> +               }
> +
> +               /* Supported operation but unable to parse the message. */
> +               if (!consumed)
> +                       goto out;
> +
> +               /* Next async message. */
> +               used += qcomtee_msg_offset_align(consumed);
> +       }
> +
> +out:
> +       /* Reset the async buffer so async requests do not loop to QTEE. */
> +       memzero_explicit(async_buffer.addr, async_buffer.size);
> +}
> diff --git a/drivers/tee/qcomtee/call.c b/drivers/tee/qcomtee/call.c
> new file mode 100644
> index 000000000000..f7f5c2c0bebb
> --- /dev/null
> +++ b/drivers/tee/qcomtee/call.c
> @@ -0,0 +1,753 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/slab.h>
> +#include <linux/tee.h>
> +#include <linux/platform_device.h>
> +
> +#include "qcomtee_private.h"
> +
> +static int find_qtee_object(struct qcomtee_object **object, unsigned long id,
> +                           struct qcomtee_context_data *ctxdata)
> +{
> +       int err = 0;
> +
> +       guard(rcu)();

Does the qcomtee_object_get() call need to be RCU protected?

> +       /* Object release is RCU protected. */
> +       *object = idr_find(&ctxdata->qtee_objects_idr, id);
> +       if (!qcomtee_object_get(*object))
> +               err = -EINVAL;
> +
> +       return err;
> +}
> +
> +static void del_qtee_object(unsigned long id,
> +                           struct qcomtee_context_data *ctxdata)
> +{
> +       struct qcomtee_object *object;
> +
> +       scoped_guard(spinlock, &ctxdata->qtee_lock)
> +               object = idr_remove(&ctxdata->qtee_objects_idr, id);
> +
> +       qcomtee_object_put(object);
> +}
> +
> +/**
> + * qcomtee_context_add_qtee_object() - Add a QTEE object to the context.
> + * @param: TEE parameter representing @object.
> + * @object: QTEE object.
> + * @ctx: context to add the object.
> + *
> + * It assumes @object is %QCOMTEE_OBJECT_TYPE_TEE and the caller has already
> + * issued qcomtee_object_get() for @object.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_context_add_qtee_object(struct tee_param *param,
> +                                   struct qcomtee_object *object,
> +                                   struct tee_context *ctx)
> +{
> +       int ret;
> +       struct qcomtee_context_data *ctxdata = ctx->data;
> +
> +       guard(spinlock)(&ctxdata->qtee_lock);
> +       ret = idr_alloc(&ctxdata->qtee_objects_idr, object, 0, 0, GFP_KERNEL);
> +       if (ret < 0)
> +               return ret;
> +

Is the spinlock needed when updating param below?

> +       param->u.objref.id = ret;
> +       /* QTEE Object: QCOMTEE_OBJREF_FLAG_TEE set. */
> +       param->u.objref.flags = QCOMTEE_OBJREF_FLAG_TEE;
> +
> +       return 0;
> +}
> +
> +/* Retrieve the QTEE object added with qcomtee_context_add_qtee_object(). */
> +int qcomtee_context_find_qtee_object(struct qcomtee_object **object,
> +                                    struct tee_param *param,
> +                                    struct tee_context *ctx)
> +{
> +       struct qcomtee_context_data *ctxdata = ctx->data;
> +
> +       /* 'qtee_objects_idr' stores QTEE objects only. */
> +       if (!(param->u.objref.flags & QCOMTEE_OBJREF_FLAG_TEE))
> +               return -EINVAL;
> +
> +       return find_qtee_object(object, param->u.objref.id, ctxdata);
> +}
> +
> +/**
> + * qcomtee_context_del_qtee_object() - Delete a QTEE object from the context.
> + * @param: TEE parameter representing @object.
> + * @ctx: context for deleting the object.
> + *
> + * The @param has been initialized by qcomtee_context_add_qtee_object().
> + */
> +void qcomtee_context_del_qtee_object(struct tee_param *param,
> +                                    struct tee_context *ctx)
> +{
> +       struct qcomtee_context_data *ctxdata = ctx->data;
> +
> +       /* 'qtee_objects_idr' stores QTEE objects only. */
> +       if (param->u.objref.flags & QCOMTEE_OBJREF_FLAG_TEE)
> +               del_qtee_object(param->u.objref.id, ctxdata);
> +}
> +
> +/**
> + * qcomtee_objref_to_arg() - Convert OBJREF parameter to QTEE argument.
> + * @arg: QTEE argument.
> + * @param: TEE parameter.
> + * @ctx: context in which the conversion should happen.
> + *
> + * It assumes @param is an OBJREF.
> + * It does not set @arg.type; the caller should initialize it to a correct
> + * &enum qcomtee_arg_type value. It gets the object's refcount in @arg;
> + * the caller should manage to put it afterward.
> + *
> + * For objects that are not in QTEE (i.e. !(param->u.objref.flags &
> + * QCOMTEE_OBJREF_FLAG_TEE)), it also calls qcomtee_object_get() to keep a
> + * temporary copy for the driver as the release of them are asynchronous and
> + * may go away even before returning from the invocation.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_objref_to_arg(struct qcomtee_arg *arg, struct tee_param *param,
> +                         struct tee_context *ctx)
> +{
> +       struct qcomtee_object *object;
> +       int err;
> +
> +       /* param is a NULL object: */
> +       if (param->u.objref.id == TEE_OBJREF_NULL) {
> +               arg->o = NULL_QCOMTEE_OBJECT;
> +
> +               return 0;
> +       }
> +
> +       /* param is a callback object: */
> +       if (param->u.objref.flags & QCOMTEE_OBJREF_FLAG_USER) {
> +               err = qcomtee_user_param_to_object(&object, param, ctx);

How about a qcomtee_get_object_from_user_param() that already has
increased the refcount? That should balance better with
qcomtee_context_find_qtee_object().

> +               if (!err)
> +                       qcomtee_object_get(object);
> +       /* param is a QTEE object: */
> +       } else if (param->u.objref.flags & QCOMTEE_OBJREF_FLAG_TEE) {
> +               err = qcomtee_context_find_qtee_object(&object, param, ctx);
> +       } else {
> +               err = -EINVAL;
> +       }
> +
> +       arg->o = err ? NULL_QCOMTEE_OBJECT : object;

I prefer an if statement here instead of the ternary operator

> +
> +       return err;
> +}
> +
> +/**
> + * qcomtee_objref_from_arg() - Convert QTEE argument to OBJREF param.
> + * @param: TEE parameter.
> + * @arg: QTEE argument.
> + * @ctx: context in which the conversion should happen.
> + *
> + * It assumes @arg is of %QCOMTEE_ARG_TYPE_IO or %QCOMTEE_ARG_TYPE_OO.
> + * It does not set @param.attr; the caller should initialize it to a
> + * correct type.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_objref_from_arg(struct tee_param *param, struct qcomtee_arg *arg,
> +                           struct tee_context *ctx)
> +{
> +       struct qcomtee_object *object;
> +       int err;
> +
> +       /* param should be of OBJREF. */
> +       if (param->attr != TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT &&
> +           param->attr != TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT &&
> +           param->attr != TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INOUT)
> +               return -EINVAL;
> +
> +       object = arg->o;
> +
> +       switch (typeof_qcomtee_object(object)) {
> +       case QCOMTEE_OBJECT_TYPE_NULL:
> +               param->u.objref.id = TEE_OBJREF_NULL;
> +               err = 0;
> +
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_CB:
> +               if (is_qcomtee_user_object(object))
> +                       err = qcomtee_user_param_from_object(param, object,
> +                                                            ctx);
> +               else
> +                       err = -EINVAL;
> +
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_TEE:
> +               err = qcomtee_context_add_qtee_object(param, object, ctx);
> +
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_ROOT:
> +       default:
> +               return -EINVAL;
> +       }
> +
> +       return err;
> +}
> +
> +/**
> + * qcomtee_params_to_args() - Convert TEE parameters to QTEE arguments.
> + * @u: QTEE arguments.
> + * @params: TEE parameters.
> + * @num_params: number of elements in the parameter array.
> + * @ctx: context in which the conversion should happen.
> + *
> + * It assumes @u has at least @num_params + 1 entries and has been initialized
> + * with %QCOMTEE_ARG_TYPE_INV as &struct qcomtee_arg.type.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +static int qcomtee_params_to_args(struct qcomtee_arg *u,
> +                                 struct tee_param *params, int num_params,
> +                                 struct tee_context *ctx)
> +{
> +       int i;
> +
> +       for (i = 0; i < num_params; i++) {
> +               switch (params[i].attr) {
> +               case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT:
> +               case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
> +                       u[i].flags = QCOMTEE_ARG_FLAGS_UADDR;
> +                       u[i].b.uaddr = params[i].u.ubuf.uaddr;
> +                       u[i].b.size = params[i].u.ubuf.size;
> +
> +                       if (params[i].attr ==
> +                           TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT)
> +                               u[i].type = QCOMTEE_ARG_TYPE_IB;
> +                       else /* TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT */
> +                               u[i].type = QCOMTEE_ARG_TYPE_OB;
> +
> +                       break;
> +               case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT:
> +                       u[i].type = QCOMTEE_ARG_TYPE_IO;
> +                       if (qcomtee_objref_to_arg(&u[i], &params[i], ctx))
> +                               goto out_failed;
> +
> +                       break;
> +               case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT:
> +                       u[i].type = QCOMTEE_ARG_TYPE_OO;
> +                       u[i].o = NULL_QCOMTEE_OBJECT;
> +                       break;
> +               default:
> +                       goto out_failed;
> +               }
> +       }
> +
> +       return 0;
> +
> +out_failed:
> +       /* Undo qcomtee_objref_to_arg(). */
> +       for (i--; i >= 0; i--) {
> +               if (u[i].type != QCOMTEE_ARG_TYPE_IO)
> +                       continue;
> +
> +               qcomtee_user_object_set_notify(u[i].o, false);
> +               if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)
> +                       qcomtee_object_put(u[i].o);
> +
> +               qcomtee_object_put(u[i].o);
> +       }
> +
> +       return -EINVAL;
> +}
> +
> +/**
> + * qcomtee_params_from_args() - Convert QTEE arguments to TEE parameters.
> + * @params: TEE parameters.
> + * @u: QTEE arguments.
> + * @num_params: number of elements in the parameter array.
> + * @ctx: context in which the conversion should happen.
> + *
> + * @u should have already been initialized by qcomtee_params_to_args().
> + * This also represents the end of a QTEE invocation that started with
> + * qcomtee_params_to_args() by releasing %QCOMTEE_ARG_TYPE_IO objects.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +static int qcomtee_params_from_args(struct tee_param *params,
> +                                   struct qcomtee_arg *u, int num_params,
> +                                   struct tee_context *ctx)
> +{
> +       int i, np;
> +
> +       qcomtee_arg_for_each(np, u) {
> +               if (u[np].type == QCOMTEE_ARG_TYPE_OB) {

Can we use switch(u[np].type)?

> +                       /* TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT */
> +                       params[np].u.value.b = u[np].b.size;

Should this be params[np].u.ubuf.size?

> +
> +               } else if (u[np].type == QCOMTEE_ARG_TYPE_IO) {
> +                       /* IEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT */
> +                       qcomtee_object_put(u[np].o);
> +
> +               } else if (u[np].type == QCOMTEE_ARG_TYPE_OO) {
> +                       /* TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT */
> +                       if (qcomtee_objref_from_arg(&params[np], &u[np], ctx))
> +                               goto out_failed;
> +               }
> +       }
> +
> +       return 0;
> +
> +out_failed:
> +       /* Undo qcomtee_objref_from_arg(). */
> +       for (i = 0; i < np; i++) {
> +               if (params[i].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT)
> +                       qcomtee_context_del_qtee_object(&params[i], ctx);
> +       }
> +
> +       /* Release any IO and OO objects not processed. */
> +       for (; u[i].type; i++) {
> +               if (u[i].type == QCOMTEE_ARG_TYPE_OO ||
> +                   u[i].type == QCOMTEE_ARG_TYPE_IO)
> +                       qcomtee_object_put(u[i].o);
> +       }
> +
> +       return -EINVAL;
> +}
> +
> +/* TEE Device Ops. */
> +
> +static int qcomtee_params_check(struct tee_param *params, int num_params)
> +{
> +       int io = 0, oo = 0, ib = 0, ob = 0;
> +       int i;
> +
> +       /* QTEE accepts 64 arguments. */
> +       if (num_params > QCOMTEE_ARGS_MAX)
> +               return -EINVAL;
> +
> +       /* Supported parameter types. */
> +       for (i = 0; i < num_params; i++) {
> +               switch (params[i].attr) {
> +               case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT:
> +                       ib++;
> +                       break;
> +               case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
> +                       ob++;
> +                       break;
> +               case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT:
> +                       io++;
> +                       break;
> +               case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT:
> +                       oo++;
> +                       break;
> +               default:
> +                       return -EINVAL;
> +               }
> +       }
> +
> +       /*  QTEE accepts 16 arguments of each supported types. */
> +       if (io > QCOMTEE_ARGS_PER_TYPE || oo > QCOMTEE_ARGS_PER_TYPE ||
> +           ib > QCOMTEE_ARGS_PER_TYPE || ob > QCOMTEE_ARGS_PER_TYPE)
> +               return -EINVAL;
> +
> +       return 0;
> +}
> +
> +/* Check if an operation on ROOT_QCOMTEE_OBJECT from userspace is permitted. */
> +static int qcomtee_root_object_check(u32 op, struct tee_param *params,
> +                                    int num_params)
> +{
> +       /* Some privileged operations recognized by QTEE. */
> +       if (op == QCOMTEE_ROOT_OP_NOTIFY_DOMAIN_CHANGE ||
> +           op == QCOMTEE_ROOT_OP_ADCI_ACCEPT ||
> +           op == QCOMTEE_ROOT_OP_ADCI_SHUTDOWN)
> +               return -EINVAL;
> +
> +       /*
> +        * QCOMTEE_ROOT_OP_REGISTER_WITH_CREDENTIALS is to register with QTEE
> +        * by passing a credential object as input OBJREF. TEE_OBJREF_NULL as a
> +        * credential object represents a privileged client for QTEE and
> +        * is used by the kernel only.
> +        */
> +       if (op == QCOMTEE_ROOT_OP_REGISTER_WITH_CREDENTIALS &&
> +           num_params == 2) {
> +               if (params[0].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT &&
> +                   params[1].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT) {
> +                       if (params[0].u.objref.id == TEE_OBJREF_NULL)
> +                               return -EINVAL;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +/**
> + * qcomtee_object_invoke() - Invoke a QTEE object.
> + * @ctx: TEE context.
> + * @arg: ioctl arguments.
> + * @params: parameters for the object.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +static int qcomtee_object_invoke(struct tee_context *ctx,
> +                                struct tee_ioctl_object_invoke_arg *arg,
> +                                struct tee_param *params)
> +{
> +       struct qcomtee_object_invoke_ctx *oic __free(kfree) = NULL;
> +       struct qcomtee_context_data *ctxdata = ctx->data;
> +       struct qcomtee_arg *u __free(kfree) = NULL;
> +       struct qcomtee_object *object;
> +       int i, ret, result;
> +
> +       if (qcomtee_params_check(params, arg->num_params))
> +               return -EINVAL;
> +
> +       /* First, handle reserved operations: */
> +       if (arg->op == QCOMTEE_MSG_OBJECT_OP_RELEASE) {
> +               del_qtee_object(arg->object, ctxdata);
> +
> +               return 0;
> +       }
> +
> +       /* Otherwise, invoke a QTEE object: */
> +       oic = qcomtee_object_invoke_ctx_alloc(ctx);
> +       if (!oic)
> +               return -ENOMEM;
> +
> +       /* +1 for ending QCOMTEE_ARG_TYPE_INV. */
> +       u = kcalloc(arg->num_params + 1, sizeof(*u), GFP_KERNEL);
> +       if (!u)
> +               return -ENOMEM;
> +
> +       /* Get an object to invoke. */
> +       if (arg->object == TEE_OBJREF_NULL) {
> +               /* Use ROOT if TEE_OBJREF_NULL is invoked. */
> +               if (qcomtee_root_object_check(arg->op, params, arg->num_params))
> +                       return -EINVAL;
> +
> +               object = ROOT_QCOMTEE_OBJECT;
> +       } else if (find_qtee_object(&object, arg->object, ctxdata)) {
> +               return -EINVAL;
> +       }
> +
> +       ret = qcomtee_params_to_args(u, params, arg->num_params, ctx);
> +       if (ret)
> +               goto out;
> +
> +       ret = qcomtee_object_do_invoke(oic, object, arg->op, u, &result);
> +       if (ret) {
> +               qcomtee_arg_for_each_input_object(i, u) {
> +                       qcomtee_user_object_set_notify(u[i].o, false);
> +                       qcomtee_object_put(u[i].o);
> +               }
> +
> +               goto out;
> +       }
> +
> +       if (!result) {
> +               /* Assume service is UNAVAIL if unable to process the result. */
> +               if (qcomtee_params_from_args(params, u, arg->num_params, ctx))
> +                       result = QCOMTEE_MSG_ERROR_UNAVAIL;
> +       } else {
> +               /*
> +                * qcomtee_params_to_args() gets a copy of IO for the driver to
> +                * make sure they do not get released while in the middle of
> +                * invocation. On success (!result), qcomtee_params_from_args()
> +                * puts them.
> +                */
> +               qcomtee_arg_for_each_input_object(i, u)
> +                       qcomtee_object_put(u[i].o);
> +       }
> +
> +       arg->ret = result;
> +out:
> +       qcomtee_object_put(object);
> +
> +       return ret;
> +}
> +
> +/**
> + * qcomtee_supp_recv() - Wait for a request for the supplicant.
> + * @ctx: TEE context.
> + * @op: requested operation on the object.
> + * @num_params: number of elements in the parameter array.
> + * @params: parameters for @op.
> + *
> + * The first parameter is a meta %TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT.
> + * On input, it provides a user buffer. This buffer is used for parameters of
> + * type %TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT in qcomtee_cb_params_from_args().
> + * On output, the object ID and request ID are stored in the meta parameter.
> + *
> + * @num_params is updated to the number of parameters that actually exist
> + * in @params on return.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +static int qcomtee_supp_recv(struct tee_context *ctx, u32 *op, u32 *num_params,
> +                            struct tee_param *params)
> +{
> +       struct qcomtee_user_object_request_data data;
> +       void __user *uaddr;
> +       size_t ubuf_size;
> +       int i, ret;
> +
> +       if (!*num_params)
> +               return -EINVAL;
> +
> +       /* We expect the first parameter to be an INOUT + meta parameter. */
> +       if (params->attr !=
> +           (TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT | TEE_IOCTL_PARAM_ATTR_META))

Why aren't you using TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_*?

> +               return -EINVAL;
> +
> +       /* Other parameters are none. */
> +       for (i = 1; i < *num_params; i++)
> +               if (params[i].attr)
> +                       return -EINVAL;
> +
> +       if (!IS_ALIGNED(params->u.value.a, 8))
> +               return -EINVAL;
> +
> +       /* User buffer and size from meta parameter. */
> +       uaddr = u64_to_user_ptr(params->u.value.a);
> +       ubuf_size = params->u.value.b;

Please use params->u.ubuf.uaddr and params->u.ubuf.size instead

> +       /* Process TEE parameters. +/-1 to ignore the meta parameter. */
> +       ret = qcomtee_user_object_select(ctx, params + 1, *num_params - 1,
> +                                        uaddr, ubuf_size, &data);
> +       if (ret)
> +               return ret;
> +
> +       params->u.value.a = data.object_id;
> +       params->u.value.b = data.id;

 params->u.objref.{id, flags}?
Should params->attr be updated with TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_*?

> +       params->u.value.c = 0;
> +       *op = data.op;
> +       *num_params = data.np + 1;
> +
> +       return 0;
> +}
> +
> +/**
> + * qcomtee_supp_send() - Submit a response for a request.
> + * @ctx: TEE context.
> + * @errno: return value for the request.
> + * @num_params: number of elements in the parameter array.
> + * @params: returned parameters.
> + *
> + * The first parameter is a meta %TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT.
> + * It specifies the request ID this response belongs to.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +static int qcomtee_supp_send(struct tee_context *ctx, u32 errno, u32 num_params,
> +                            struct tee_param *params)
> +{
> +       if (!num_params)
> +               return -EINVAL;
> +
> +       /* We expect the first parameter to be an OUTPUT + meta parameter. */
> +       if (params->attr != (TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT |
> +                            TEE_IOCTL_PARAM_ATTR_META))
> +               return -EINVAL;

Why is this used if it's to be ignored, making room for forward compatibility?

> +
> +       /* Process TEE parameters. +/-1 to ignore the meta parameter. */
> +       return qcomtee_user_object_submit(ctx, params + 1, num_params - 1,
> +                                         params->u.value.a, errno);
> +}
> +
> +static int qcomtee_open(struct tee_context *ctx)
> +{
> +       struct qcomtee_context_data *ctxdata __free(kfree) = NULL;
> +
> +       ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
> +       if (!ctxdata)
> +               return -ENOMEM;
> +
> +       /*
> +        * In the QTEE driver, the same context is used to refcount resources
> +        * shared by QTEE. For example, teedev_ctx_get() is called for any
> +        * instance of callback objects (see qcomtee_user_param_to_object()).
> +        *
> +        * Maintain a copy of teedev for QTEE as it serves as a direct user of
> +        * this context. The teedev will be released in the context's release().
> +        *
> +        * tee_device_unregister() will remain blocked until all contexts
> +        * are released. This includes contexts owned by the user, which are
> +        * closed by teedev_close_context(), as well as those owned by QTEE
> +        * closed by tee_context_put() in object's release().
> +        */
> +       if (!tee_device_get(ctx->teedev))
> +               return -EINVAL;
> +
> +       idr_init(&ctxdata->qtee_objects_idr);
> +       spin_lock_init(&ctxdata->qtee_lock);
> +       idr_init(&ctxdata->reqs_idr);
> +       INIT_LIST_HEAD(&ctxdata->reqs_list);
> +       mutex_init(&ctxdata->reqs_lock);
> +       init_completion(&ctxdata->req_c);
> +
> +       ctx->data = no_free_ptr(ctxdata);
> +
> +       return 0;
> +}
> +
> +/* This is called when the user closes the device. */
> +static void qcomtee_close_context(struct tee_context *ctx)
> +{
> +       struct qcomtee_context_data *ctxdata = ctx->data;
> +       struct qcomtee_object *object;
> +       int id;
> +
> +       /* Process QUEUED or PROCESSING requests. */
> +       qcomtee_requests_destroy(ctxdata);
> +       /* Release QTEE objects. */
> +       idr_for_each_entry(&ctxdata->qtee_objects_idr, object, id)
> +               qcomtee_object_put(object);
> +}
> +
> +/* This is called when the final reference to the context goes away. */
> +static void qcomtee_release(struct tee_context *ctx)
> +{
> +       struct qcomtee_context_data *ctxdata = ctx->data;
> +
> +       idr_destroy(&ctxdata->qtee_objects_idr);
> +       idr_destroy(&ctxdata->reqs_idr);
> +       kfree(ctxdata);
> +
> +       /* There is nothing shared in this context with QTEE. */
> +       tee_device_put(ctx->teedev);
> +}
> +
> +static void qcomtee_get_version(struct tee_device *teedev,
> +                               struct tee_ioctl_version_data *vers)
> +{
> +       struct tee_ioctl_version_data v = {
> +               .impl_id = TEE_IMPL_ID_QTEE,
> +               .gen_caps = TEE_GEN_CAP_OBJREF,
> +       };
> +
> +       *vers = v;
> +}
> +
> +static const struct tee_driver_ops qcomtee_ops = {
> +       .get_version = qcomtee_get_version,
> +       .open = qcomtee_open,
> +       .close_context = qcomtee_close_context,
> +       .release = qcomtee_release,
> +       .object_invoke_func = qcomtee_object_invoke,
> +       .supp_recv = qcomtee_supp_recv,
> +       .supp_send = qcomtee_supp_send,
> +};
> +
> +static const struct tee_desc qcomtee_desc = {
> +       .name = "qcomtee",
> +       .ops = &qcomtee_ops,
> +       .owner = THIS_MODULE,
> +};
> +
> +static int qcomtee_probe(struct platform_device *pdev)
> +{
> +       struct workqueue_struct *async_wq;
> +       struct tee_device *teedev;
> +       struct tee_shm_pool *pool;
> +       struct tee_context *ctx;
> +       struct qcomtee *qcomtee;
> +       int err;
> +
> +       qcomtee = kzalloc(sizeof(*qcomtee), GFP_KERNEL);
> +       if (!qcomtee)
> +               return -ENOMEM;
> +
> +       pool = qcomtee_shm_pool_alloc();
> +       if (IS_ERR(pool)) {
> +               err = PTR_ERR(pool);
> +
> +               goto err_free_qcomtee;
> +       }
> +
> +       teedev = tee_device_alloc(&qcomtee_desc, NULL, pool, qcomtee);
> +       if (IS_ERR(teedev)) {
> +               err = PTR_ERR(teedev);
> +
> +               goto err_pool_destroy;
> +       }
> +
> +       qcomtee->teedev = teedev;
> +       qcomtee->pool = pool;
> +       err = tee_device_register(qcomtee->teedev);
> +       if (err)
> +               goto err_unreg_teedev;
> +
> +       platform_set_drvdata(pdev, qcomtee);
> +       /* Start async wq. */
> +       async_wq = alloc_ordered_workqueue("qcomtee_wq", 0);
> +       if (!async_wq)
> +               goto err_unreg_teedev;
> +
> +       qcomtee->wq = async_wq;
> +       /* Driver context used for async operations of teedev. */
> +       ctx = teedev_open(qcomtee->teedev);
> +       if (IS_ERR(ctx)) {
> +               err = PTR_ERR(ctx);
> +
> +               goto err_dest_wq;
> +       }
> +
> +       qcomtee->ctx = ctx;
> +
> +       return 0;
> +
> +err_dest_wq:
> +       destroy_workqueue(qcomtee->wq);
> +err_unreg_teedev:
> +       tee_device_unregister(qcomtee->teedev);
> +err_pool_destroy:
> +       tee_shm_pool_free(pool);
> +err_free_qcomtee:
> +       kfree(qcomtee);
> +
> +       return err;
> +}
> +
> +/**
> + * qcomtee_remove() - Device Removal Routine.
> + * @pdev: platform device information struct.
> + *
> + * It is called by the platform subsystem to alert the driver that it should
> + * release the device.
> + *
> + * QTEE does not provide an API to inform it about a callback object going away.
> + * However, when releasing QTEE objects, any callback object sent to QTEE
> + * previously would be released by QTEE as part of the object release.
> + */
> +static void qcomtee_remove(struct platform_device *pdev)
> +{
> +       struct qcomtee *qcomtee = platform_get_drvdata(pdev);
> +
> +       teedev_close_context(qcomtee->ctx);
> +       /* Wait for RELEASE operations to be processed for QTEE objects. */
> +       tee_device_unregister(qcomtee->teedev);
> +       destroy_workqueue(qcomtee->wq);
> +       tee_shm_pool_free(qcomtee->pool);
> +       kfree(qcomtee);
> +}
> +
> +static const struct platform_device_id qcomtee_ids[] = { { "qcomtee", 0 }, {} };
> +MODULE_DEVICE_TABLE(platform, qcomtee_ids);
> +
> +static struct platform_driver qcomtee_platform_driver = {
> +       .probe = qcomtee_probe,
> +       .remove = qcomtee_remove,
> +       .driver = {
> +               .name = "qcomtee",
> +       },
> +       .id_table = qcomtee_ids,
> +};
> +
> +module_platform_driver(qcomtee_platform_driver);
> +
> +MODULE_AUTHOR("Qualcomm");
> +MODULE_DESCRIPTION("QTEE driver");
> +MODULE_VERSION("1.0");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/tee/qcomtee/core.c b/drivers/tee/qcomtee/core.c
> new file mode 100644
> index 000000000000..162e32db656a
> --- /dev/null
> +++ b/drivers/tee/qcomtee/core.c
> @@ -0,0 +1,801 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/xarray.h>
> +
> +#include "qcomtee_msg.h"
> +#include "qcomtee_private.h"
> +
> +/* This is the QTEE root object. */
> +struct qcomtee_object qcomtee_object_root = {
> +       .name = "root",
> +       .object_type = QCOMTEE_OBJECT_TYPE_ROOT,
> +       .info.qtee_id = QCOMTEE_MSG_OBJECT_ROOT,
> +};
> +EXPORT_SYMBOL_GPL(qcomtee_object_root);
> +
> +/* Next argument of type @type after index @i. */
> +int qcomtee_next_arg_type(struct qcomtee_arg *u, int i,
> +                         enum qcomtee_arg_type type)
> +{
> +       while (u[i].type != QCOMTEE_ARG_TYPE_INV && u[i].type != type)
> +               i++;
> +       return i;
> +}
> +
> +/*
> + * QTEE expects IDs with the QCOMTEE_MSG_OBJECT_NS_BIT set for objects
> + * of the QCOMTEE_OBJECT_TYPE_CB type.
> + */
> +#define QCOMTEE_OBJECT_ID_START (QCOMTEE_MSG_OBJECT_NS_BIT + 1)
> +#define QCOMTEE_OBJECT_ID_END (UINT_MAX)

Should this be U32_MAX considering that QCOMTEE_MSG_OBJECT_NS_BIT is
defined as BIT(31)?

> +
> +#define QCOMTEE_OBJECT_SET(p, type, ...) \
> +       __QCOMTEE_OBJECT_SET(p, type, ##__VA_ARGS__, 0UL)
> +#define __QCOMTEE_OBJECT_SET(p, type, optr, ...)           \
> +       do {                                               \
> +               (p)->object_type = (type);                 \
> +               (p)->info.qtee_id = (unsigned long)(optr); \
> +       } while (0)
> +
> +static struct qcomtee_object *
> +qcomtee_qtee_object_alloc(struct qcomtee_object_invoke_ctx *oic,
> +                         unsigned int object_id)
> +{
> +       struct qcomtee *qcomtee = tee_get_drvdata(oic->ctx->teedev);
> +       struct qcomtee_object *object __free(kfree);
> +
> +       object = kzalloc(sizeof(*object), GFP_KERNEL);
> +       if (!object)
> +               return NULL_QCOMTEE_OBJECT;
> +
> +       /* If failed, "no-name". */
> +       object->name = kasprintf(GFP_KERNEL, "qcomtee-%u", object_id);

Where does it become "no-name" if object->name is NULL? Is it worth it
with a special case for the unlikely condition that kasprintf() fails
while no other memory allocations fail?

> +       QCOMTEE_OBJECT_SET(object, QCOMTEE_OBJECT_TYPE_TEE, object_id);
> +       kref_init(&object->refcount);
> +       /* A QTEE object requires a context for async operations. */
> +       object->info.qcomtee_async_ctx = qcomtee->ctx;
> +       teedev_ctx_get(object->info.qcomtee_async_ctx);
> +
> +       return no_free_ptr(object);
> +}
> +
> +void qcomtee_qtee_object_free(struct qcomtee_object *object)
> +{
> +       /* See qcomtee_qtee_object_alloc(). */
> +       teedev_ctx_put(object->info.qcomtee_async_ctx);
> +
> +       kfree(object->name);
> +       kfree(object);
> +}
> +
> +static void qcomtee_object_release(struct kref *refcount)
> +{
> +       struct qcomtee_object *object;
> +       const char *name;
> +
> +       object = container_of(refcount, struct qcomtee_object, refcount);
> +
> +       synchronize_rcu();

Please add a comment in the code explaining why this is needed.

> +
> +       switch (typeof_qcomtee_object(object)) {
> +       case QCOMTEE_OBJECT_TYPE_TEE:
> +               qcomtee_release_tee_object(object);
> +
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_CB:
> +               name = object->name;
> +
> +               if (object->ops->release)
> +                       object->ops->release(object);
> +
> +               kfree_const(name);
> +
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_ROOT:
> +       case QCOMTEE_OBJECT_TYPE_NULL:
> +       default:
> +               break;
> +       }
> +}
> +
> +/**
> + * qcomtee_object_get() - Increase the object's reference count.
> + * @object: object to increase the reference count.
> + */
> +int qcomtee_object_get(struct qcomtee_object *object)
> +{
> +       if (object != NULL_QCOMTEE_OBJECT && object != ROOT_QCOMTEE_OBJECT)
> +               return kref_get_unless_zero(&object->refcount);
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(qcomtee_object_get);
> +
> +/**
> + * qcomtee_object_put() - Decrease the object's reference count.
> + * @object: object to decrease the reference count.
> + */
> +void qcomtee_object_put(struct qcomtee_object *object)
> +{
> +       if (object != NULL_QCOMTEE_OBJECT && object != ROOT_QCOMTEE_OBJECT)
> +               kref_put(&object->refcount, qcomtee_object_release);
> +}
> +EXPORT_SYMBOL_GPL(qcomtee_object_put);
> +
> +/*
> + * ''Local Object Table''.
> + * Objects from the kernel exported to QTEE are assigned an ID and stored
> + * in xa_qcom_local_objects (also known as the kernel object table).
> + * QTEE uses this ID to reference the objects using qcomtee_local_object_get().
> + */
> +static DEFINE_XARRAY_ALLOC(xa_qcom_local_objects);

Please move this to the top of this file where the other global
variables are kept. Do we have/need any checks to see the unrelated
processes doesn't use objects from each other because they manage to
guess an id?

> +
> +static int qcomtee_idx_alloc(u32 *idx, struct qcomtee_object *object)
> +{
> +       static u32 xa_last_id = QCOMTEE_OBJECT_ID_START;
> +
> +       /* Every ID allocated here has QCOMTEE_MSG_OBJECT_NS_BIT set. */
> +       return xa_alloc_cyclic(&xa_qcom_local_objects, idx, object,
> +                              XA_LIMIT(QCOMTEE_OBJECT_ID_START,
> +                                       QCOMTEE_OBJECT_ID_END),
> +                              &xa_last_id, GFP_KERNEL);
> +}
> +
> +struct qcomtee_object *qcomtee_idx_erase(u32 idx)
> +{
> +       if (idx < QCOMTEE_OBJECT_ID_START || idx > QCOMTEE_OBJECT_ID_END)
> +               return NULL_QCOMTEE_OBJECT;
> +
> +       return xa_erase(&xa_qcom_local_objects, idx);
> +}
> +
> +/**
> + * qcomtee_object_id_get() - Get an ID for an object to send to QTEE.
> + * @object: object to assign an ID.
> + * @object_id: object ID.
> + *
> + * This is called on the path to QTEE to construct the message; see
> + * qcomtee_prepare_msg() and qcomtee_update_msg().
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +static int qcomtee_object_id_get(struct qcomtee_object *object,
> +                                unsigned int *object_id)
> +{
> +       u32 idx;
> +
> +       switch (typeof_qcomtee_object(object)) {
> +       case QCOMTEE_OBJECT_TYPE_CB:
> +               if (qcomtee_idx_alloc(&idx, object) < 0)
> +                       return -ENOSPC;
> +
> +               *object_id = idx;
> +
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_ROOT:
> +       case QCOMTEE_OBJECT_TYPE_TEE:
> +               *object_id = object->info.qtee_id;
> +
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_NULL:
> +               *object_id = QCOMTEE_MSG_OBJECT_NULL;
> +
> +               break;
> +       }
> +
> +       return 0;
> +}
> +
> +/* Release object ID assigned in qcomtee_object_id_get. */
> +static void qcomtee_object_id_put(unsigned int object_id)
> +{
> +       qcomtee_idx_erase(object_id);
> +}
> +
> +/**
> + * qcomtee_local_object_get() - Get the object referenced by the ID.
> + * @object_id: object ID.
> + *
> + * It is called on the path from QTEE.
> + * It is called on behalf of QTEE to obtain an instance of an object
> + * for a given ID. It increases the object's reference count on success.
> + *
> + * Return: On error, returns %NULL_QCOMTEE_OBJECT.
> + *         On success, returns the object.
> + */
> +static struct qcomtee_object *qcomtee_local_object_get(unsigned int object_id)
> +{
> +       struct qcomtee_object *object;
> +
> +       /*
> +        * This is not protected by an RCU read lock because we are
> +        * confident that QTEE does not issue a RELEASE request and
> +        * qcomtee_local_object_get() concurrently.
> +        */

I think it would be better to not depend on that. An RCU read lock
must be very cheap compared to what we do in this context.

> +       object = xa_load(&xa_qcom_local_objects, object_id);
> +
> +       qcomtee_object_get(object);
> +
> +       return object;
> +}
> +
> +/**
> + * qcomtee_object_user_init() - Initialize an object for the user.
> + * @object: object to initialize.
> + * @ot: type of object as &enum qcomtee_object_type.
> + * @ops: instance of callbacks.
> + * @fmt: name assigned to the object.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_object_user_init(struct qcomtee_object *object,
> +                            enum qcomtee_object_type ot,
> +                            struct qcomtee_object_operations *ops,
> +                            const char *fmt, ...)
> +{
> +       va_list ap;
> +       int ret;
> +
> +       kref_init(&object->refcount);
> +       QCOMTEE_OBJECT_SET(object, QCOMTEE_OBJECT_TYPE_NULL);
> +
> +       va_start(ap, fmt);
> +       switch (ot) {
> +       case QCOMTEE_OBJECT_TYPE_NULL:
> +               ret = 0;
> +
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_CB:
> +               object->ops = ops;
> +               if (!object->ops->dispatch)
> +                       return -EINVAL;
> +
> +               /* If failed, "no-name". */
> +               object->name = kvasprintf_const(GFP_KERNEL, fmt, ap);
> +               QCOMTEE_OBJECT_SET(object, QCOMTEE_OBJECT_TYPE_CB);
> +
> +               ret = 0;
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_ROOT:
> +       case QCOMTEE_OBJECT_TYPE_TEE:
> +       default:
> +               ret = -EINVAL;
> +       }
> +       va_end(ap);
> +
> +       return ret;
> +}
> +EXPORT_SYMBOL_GPL(qcomtee_object_user_init);
> +
> +/**
> + * qcomtee_object_type() - Returns the type of object represented by an ID.
> + * @object_id: object ID for the object.
> + *
> + * This is similar to typeof_qcomtee_object(), but instead of receiving an
> + * object as an argument, it receives an object ID. It is used internally
> + * on the return path from QTEE.
> + *
> + * Return: Returns the type of object referenced by @object_id.
> + */
> +static enum qcomtee_object_type qcomtee_object_type(unsigned int object_id)
> +{
> +       if (object_id == QCOMTEE_MSG_OBJECT_NULL)
> +               return QCOMTEE_OBJECT_TYPE_NULL;
> +
> +       if (object_id & QCOMTEE_MSG_OBJECT_NS_BIT)
> +               return QCOMTEE_OBJECT_TYPE_CB;
> +
> +       return QCOMTEE_OBJECT_TYPE_TEE;
> +}
> +
> +/**
> + * qcomtee_object_qtee_init() - Initialize an object for QTEE.
> + * @object: object returned.
> + * @object_id: object ID received from QTEE.
> + *
> + * Return: On failure, returns < 0 and sets @object to %NULL_QCOMTEE_OBJECT.
> + *         On success, returns 0
> + */
> +static int qcomtee_object_qtee_init(struct qcomtee_object_invoke_ctx *oic,
> +                                   struct qcomtee_object **object,
> +                                   unsigned int object_id)
> +{
> +       int ret = 0;
> +
> +       switch (qcomtee_object_type(object_id)) {
> +       case QCOMTEE_OBJECT_TYPE_NULL:
> +               *object = NULL_QCOMTEE_OBJECT;
> +
> +               break;
> +       case QCOMTEE_OBJECT_TYPE_CB:
> +               *object = qcomtee_local_object_get(object_id);
> +               if (*object == NULL_QCOMTEE_OBJECT)
> +                       ret = -EINVAL;
> +
> +               break;
> +
> +       default: /* QCOMTEE_OBJECT_TYPE_TEE */
> +               *object = qcomtee_qtee_object_alloc(oic, object_id);
> +               if (*object == NULL_QCOMTEE_OBJECT)
> +                       ret = -ENOMEM;
> +
> +               break;
> +       }
> +
> +       return ret;
> +}
> +
> +/*
> + * ''Marshaling API''
> + * qcomtee_prepare_msg  - Prepare the inbound buffer for sending to QTEE
> + * qcomtee_update_args  - Parse the QTEE response in the inbound buffer
> + * qcomtee_prepare_args - Parse the QTEE request from the outbound buffer
> + * qcomtee_update_msg   - Update the outbound buffer with the response for QTEE
> + */
> +
> +static int qcomtee_prepare_msg(struct qcomtee_object_invoke_ctx *oic,
> +                              struct qcomtee_object *object, u32 op,
> +                              struct qcomtee_arg *u)
> +{
> +       struct qcomtee_msg_object_invoke *msg;
> +       unsigned int object_id;
> +       int i, ib, ob, io, oo;
> +       size_t off;
> +
> +       /* Use the input message buffer in 'oic'. */
> +       msg = oic->in_msg.addr;
> +
> +       /* Start offset in a message for buffer arguments. */
> +       off = qcomtee_msg_buffer_args(struct qcomtee_msg_object_invoke,
> +                                     qcomtee_args_len(u));
> +
> +       /* Get the ID of the object being invoked. */
> +       if (qcomtee_object_id_get(object, &object_id))
> +               return -ENOSPC;
> +
> +       ib = 0;
> +       qcomtee_arg_for_each_input_buffer(i, u) {
> +               void *ptr;
> +
> +               /* Overflow already checked in qcomtee_msg_buffers_alloc(). */
> +               msg->args[ib].b.offset = off;
> +               msg->args[ib].b.size = u[i].b.size;
> +
> +               ptr = qcomtee_msg_offset_to_ptr(msg, off);
> +               /* Userspace client or kernel client!? */
> +               if (!(u[i].flags & QCOMTEE_ARG_FLAGS_UADDR))
> +                       memcpy(ptr, u[i].b.addr, u[i].b.size);
> +               else if (copy_from_user(ptr, u[i].b.uaddr, u[i].b.size))
> +                       return -EINVAL;
> +
> +               off += qcomtee_msg_offset_align(u[i].b.size);
> +               ib++;
> +       }
> +
> +       ob = ib;
> +       qcomtee_arg_for_each_output_buffer(i, u) {
> +               /* Overflow already checked in qcomtee_msg_buffers_alloc(). */
> +               msg->args[ob].b.offset = off;
> +               msg->args[ob].b.size = u[i].b.size;
> +
> +               off += qcomtee_msg_offset_align(u[i].b.size);
> +               ob++;
> +       }
> +
> +       io = ob;
> +       qcomtee_arg_for_each_input_object(i, u) {
> +               if (qcomtee_object_id_get(u[i].o, &msg->args[io].o)) {
> +                       /* Put whatever we got. */
> +                       qcomtee_object_id_put(object_id);
> +                       for (io--; io >= ob; io--)
> +                               qcomtee_object_id_put(msg->args[io].o);
> +
> +                       return -ENOSPC;
> +               }
> +
> +               io++;
> +       }
> +
> +       oo = io;
> +       qcomtee_arg_for_each_output_object(i, u)
> +               oo++;
> +
> +       /* Set object, operation, and argument counts. */
> +       qcomtee_msg_init(msg, object_id, op, ib, ob, io, oo);
> +
> +       return 0;
> +}
> +
> +/**
> + * qcomtee_update_args() - Parse the QTEE response in the inbound buffer.
> + * @u: array of arguments for the invocation.
> + * @oic: context to use for the invocation.
> + *
> + * @u must be the same as the one used in qcomtee_prepare_msg() when
> + * initializing the inbound buffer.
> + *
> + * On failure, it continues processing the QTEE message. The caller should
> + * do the necessary cleanup, including calling qcomtee_object_put()
> + * on the output objects.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +static int qcomtee_update_args(struct qcomtee_arg *u,
> +                              struct qcomtee_object_invoke_ctx *oic)
> +{
> +       struct qcomtee_msg_object_invoke *msg;
> +       int i, ib, ob, io, oo;
> +       int ret = 0;
> +
> +       /* Use the input message buffer in 'oic'. */
> +       msg = oic->in_msg.addr;
> +
> +       ib = 0;
> +       qcomtee_arg_for_each_input_buffer(i, u)
> +               ib++;
> +
> +       ob = ib;
> +       qcomtee_arg_for_each_output_buffer(i, u) {
> +               void *ptr;
> +
> +               /* QTEE can override the size to a smaller value. */
> +               u[i].b.size = msg->args[ob].b.size;
> +
> +               ptr = qcomtee_msg_offset_to_ptr(msg, msg->args[ob].b.offset);
> +               /* Userspace client or kernel client!? */
> +               if (!(u[i].flags & QCOMTEE_ARG_FLAGS_UADDR))
> +                       memcpy(u[i].b.addr, ptr, u[i].b.size);
> +               else if (copy_to_user(u[i].b.uaddr, ptr, u[i].b.size))
> +                       ret = -EINVAL;
> +
> +               ob++;
> +       }
> +
> +       io = ob;
> +       qcomtee_arg_for_each_input_object(i, u)
> +               io++;
> +
> +       oo = io;
> +       qcomtee_arg_for_each_output_object(i, u) {
> +               if (qcomtee_object_qtee_init(oic, &u[i].o, msg->args[oo].o))
> +                       ret = -EINVAL;
> +
> +               oo++;
> +       }
> +
> +       return ret;
> +}
> +
> +/**
> + * qcomtee_prepare_args() - Parse the QTEE request from the outbound buffer.
> + * @oic: context to use for the invocation.
> + *
> + * It initializes &qcomtee_object_invoke_ctx->u based on the QTEE request in
> + * the outbound buffer. It sets %QCOMTEE_ARG_TYPE_INV at the end of the array.
> + *
> + * On failure, it continues processing the QTEE message. The caller should
> + * do the necessary cleanup, including calling qcomtee_object_put()
> + * on the input objects.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +static int qcomtee_prepare_args(struct qcomtee_object_invoke_ctx *oic)
> +{
> +       struct qcomtee_msg_callback *msg;
> +       union qcomtee_msg_arg *arg;
> +       int i, ret = 0;
> +
> +       /* Use the output message buffer in 'oic'. */
> +       msg = oic->out_msg.addr;
> +
> +       qcomtee_msg_for_each_input_buffer(i, msg) {
> +               arg = &msg->args[i];
> +               oic->u[i].b.addr =
> +                       qcomtee_msg_offset_to_ptr(msg, arg->b.offset);
> +               oic->u[i].b.size = arg->b.size;
> +               oic->u[i].type = QCOMTEE_ARG_TYPE_IB;
> +       }
> +
> +       qcomtee_msg_for_each_output_buffer(i, msg) {
> +               arg = &msg->args[i];
> +               oic->u[i].b.addr =
> +                       qcomtee_msg_offset_to_ptr(msg, arg->b.offset);
> +               oic->u[i].b.size = arg->b.size;
> +               oic->u[i].type = QCOMTEE_ARG_TYPE_OB;
> +       }
> +
> +       qcomtee_msg_for_each_input_object(i, msg) {
> +               if (qcomtee_object_qtee_init(oic, &oic->u[i].o, msg->args[i].o))
> +                       ret = -EINVAL;
> +
> +               oic->u[i].type = QCOMTEE_ARG_TYPE_IO;
> +       }
> +
> +       qcomtee_msg_for_each_output_object(i, msg)
> +               oic->u[i].type = QCOMTEE_ARG_TYPE_OO;
> +
> +       /* End of Arguments. */
> +       oic->u[i].type = QCOMTEE_ARG_TYPE_INV;
> +
> +       return ret;
> +}
> +
> +static int qcomtee_update_msg(struct qcomtee_object_invoke_ctx *oic)
> +{
> +       struct qcomtee_msg_callback *msg;
> +       int i, ib, ob, io, oo;
> +
> +       /* Use the output message buffer in 'oic'. */
> +       msg = oic->out_msg.addr;
> +
> +       ib = 0;
> +       qcomtee_arg_for_each_input_buffer(i, oic->u)
> +               ib++;
> +
> +       ob = ib;
> +       qcomtee_arg_for_each_output_buffer(i, oic->u) {
> +               /* Only reduce size; never increase it. */
> +               if (msg->args[ob].b.size < oic->u[i].b.size)
> +                       return -EINVAL;
> +
> +               msg->args[ob].b.size = oic->u[i].b.size;
> +               ob++;
> +       }
> +
> +       io = ob;
> +       qcomtee_arg_for_each_input_object(i, oic->u)
> +               io++;
> +
> +       oo = io;
> +       qcomtee_arg_for_each_output_object(i, oic->u) {
> +               if (qcomtee_object_id_get(oic->u[i].o, &msg->args[oo].o)) {
> +                       /* Put whatever we got. */
> +                       for (oo--; oo >= io; oo--)
> +                               qcomtee_object_id_put(msg->args[oo].o);
> +
> +                       return -ENOSPC;
> +               }
> +
> +               oo++;
> +       }
> +
> +       return 0;
> +}
> +
> +/* Invoke a callback object. */
> +static void qcomtee_cb_object_invoke(struct qcomtee_object_invoke_ctx *oic,
> +                                    struct qcomtee_msg_callback *msg)
> +{
> +       int i, errno;
> +       u32 op;
> +
> +       /* Get the object being invoked. */
> +       unsigned int object_id = msg->cxt;
> +       struct qcomtee_object *object;
> +
> +       /* QTEE cannot invoke a NULL object or objects it hosts. */
> +       if (qcomtee_object_type(object_id) == QCOMTEE_OBJECT_TYPE_NULL ||
> +           qcomtee_object_type(object_id) == QCOMTEE_OBJECT_TYPE_TEE) {
> +               errno = -EINVAL;
> +               goto out;
> +       }
> +
> +       object = qcomtee_local_object_get(object_id);
> +       if (object == NULL_QCOMTEE_OBJECT) {
> +               errno = -EINVAL;
> +               goto out;
> +       }
> +
> +       oic->object = object;
> +
> +       /* Filter bits used by transport. */
> +       op = msg->op & QCOMTEE_MSG_OBJECT_OP_MASK;
> +
> +       switch (op) {
> +       case QCOMTEE_MSG_OBJECT_OP_RELEASE:
> +               qcomtee_object_id_put(object_id);
> +               qcomtee_object_put(object);
> +               errno = 0;
> +
> +               break;
> +       case QCOMTEE_MSG_OBJECT_OP_RETAIN:
> +               qcomtee_object_get(object);
> +               errno = 0;
> +
> +               break;
> +       default:
> +               errno = qcomtee_prepare_args(oic);
> +               if (errno) {
> +                       /* Release any object that arrived as input. */
> +                       qcomtee_arg_for_each_input_buffer(i, oic->u)
> +                               qcomtee_object_put(oic->u[i].o);
> +
> +                       break;
> +               }
> +
> +               errno = object->ops->dispatch(oic, object, op, oic->u);
> +               if (!errno) {
> +                       /* On success, notify at the appropriate time. */
> +                       oic->flags |= QCOMTEE_OIC_FLAG_NOTIFY;
> +               }
> +       }
> +
> +out:
> +
> +       oic->errno = errno;
> +}
> +
> +/**
> + * qcomtee_qtee_objects_put() - Put the callback objects in the argument array.
> + * @u: array of arguments.
> + *
> + * When qcomtee_object_do_invoke_internal() is successfully invoked,
> + * QTEE takes ownership of the callback objects. If the invocation fails,
> + * qcomtee_object_do_invoke_internal() calls qcomtee_qtee_objects_put()
> + * to mimic the release of callback objects by QTEE.
> + */
> +static void qcomtee_qtee_objects_put(struct qcomtee_arg *u)
> +{
> +       int i;
> +
> +       qcomtee_arg_for_each_input_object(i, u) {
> +               if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)
> +                       qcomtee_object_put(u[i].o);
> +       }
> +}
> +
> +/**
> + * qcomtee_object_do_invoke_internal() - Submit an invocation for an object.
> + * @oic: context to use for the current invocation.
> + * @object: object being invoked.
> + * @op: requested operation on the object.
> + * @u: array of arguments for the current invocation.
> + * @result: result returned from QTEE.
> + *
> + * The caller is responsible for keeping track of the refcount for each
> + * object, including @object. On return, the caller loses ownership of all
> + * input objects of type %QCOMTEE_OBJECT_TYPE_CB.
> + *
> + * Return: On success, returns 0. On error, returns -EAGAIN if invocation
> + * failed and the user may retry the invocation, -ENODEV on fatal failure.
> + */
> +int qcomtee_object_do_invoke_internal(struct qcomtee_object_invoke_ctx *oic,
> +                                     struct qcomtee_object *object, u32 op,
> +                                     struct qcomtee_arg *u, int *result)
> +{
> +       struct qcomtee_msg_callback *cb_msg;
> +       struct qcomtee_object *qto;
> +       int i, ret, errno;
> +       u64 res_type;
> +
> +       /* Allocate inbound and outbound buffers. */
> +       if (qcomtee_msg_buffers_alloc(oic, u)) {
> +               qcomtee_qtee_objects_put(u);
> +
> +               return -EAGAIN;
> +       }
> +
> +       if (qcomtee_prepare_msg(oic, object, op, u)) {
> +               qcomtee_qtee_objects_put(u);
> +
> +               ret = -EAGAIN;
> +               goto out;
> +       }
> +
> +       /* Use input message buffer in 'oic'. */
> +       cb_msg = oic->out_msg.addr;
> +
> +       while (1) {
> +               if (oic->flags & QCOMTEE_OIC_FLAG_BUSY) {
> +                       errno = oic->errno;
> +                       if (!errno)
> +                               errno = qcomtee_update_msg(oic);
> +                       qcomtee_msg_set_result(cb_msg, errno);
> +               }
> +
> +               /* Invoke the remote object. */
> +               ret = qcomtee_object_invoke_ctx_invoke(oic, result, &res_type);
> +
> +               if (oic->flags & QCOMTEE_OIC_FLAG_BUSY) {
> +                       qto = oic->object;
> +                       if (qto) {
> +                               if (oic->flags & QCOMTEE_OIC_FLAG_NOTIFY) {
> +                                       /* Don't care about the exact errno. */
> +                                       if (qto->ops->notify)
> +                                               qto->ops->notify(oic, qto,
> +                                                                errno || ret);
> +                               }
> +
> +                               /* Get is in qcomtee_cb_object_invoke(). */
> +                               qcomtee_object_put(qto);
> +                       }
> +
> +                       oic->object = NULL_QCOMTEE_OBJECT;
> +                       oic->flags &= ~(QCOMTEE_OIC_FLAG_BUSY |
> +                                       QCOMTEE_OIC_FLAG_NOTIFY);
> +               }
> +
> +               if (ret) {
> +                       if (!(oic->flags & QCOMTEE_OIC_FLAG_SHARED)) {
> +                               qcomtee_qtee_objects_put(u);
> +
> +                               ret = -EAGAIN;
> +                       } else {
> +                               /*
> +                                * On error, there is no clean way to exit.
> +                                * For some reason, we cannot communicate with
> +                                * QTEE, so we cannot notify QTEE about the
> +                                * failure and do further cleanup.
> +                                */
> +                               ret = -ENODEV;
> +                       }
> +
> +                       goto out;
> +
> +               } else {
> +                       /*
> +                        * QTEE obtained ownership of QCOMTEE_OBJECT_TYPE_CB
> +                        * input objects in 'u'. On further failure, QTEE is
> +                        * responsible for releasing them.
> +                        */
> +                       oic->flags |= QCOMTEE_OIC_FLAG_SHARED;
> +               }
> +
> +               /* Is it a callback request? */
> +               if (res_type != QCOMTEE_RESULT_INBOUND_REQ_NEEDED) {
> +                       if (!*result) {
> +                               ret = qcomtee_update_args(u, oic);
> +                               if (ret) {
> +                                       /* Put output objects. Retry. */
> +                                       qcomtee_arg_for_each_output_object(i, u)
> +                                               qcomtee_object_put(u[i].o);
> +
> +                                       ret = -EAGAIN;
> +                               }
> +                       }
> +
> +                       break;
> +
> +               } else {
> +                       oic->flags |= QCOMTEE_OIC_FLAG_BUSY;
> +
> +                       qcomtee_fetch_async_reqs(oic);
> +                       qcomtee_cb_object_invoke(oic, cb_msg);
> +               }
> +       }
> +
> +       qcomtee_fetch_async_reqs(oic);
> +out:
> +       qcomtee_msg_buffers_free(oic);
> +
> +       return ret;
> +}
> +
> +int qcomtee_object_do_invoke(struct qcomtee_object_invoke_ctx *oic,
> +                            struct qcomtee_object *object, u32 op,
> +                            struct qcomtee_arg *u, int *result)
> +{
> +       /* User can not set bits used by transport. */
> +       if (op & ~QCOMTEE_MSG_OBJECT_OP_MASK)
> +               return -EINVAL;
> +
> +       /* User can only invoke QTEE hosted objects. */
> +       if (typeof_qcomtee_object(object) != QCOMTEE_OBJECT_TYPE_TEE &&
> +           typeof_qcomtee_object(object) != QCOMTEE_OBJECT_TYPE_ROOT)
> +               return -EINVAL;
> +
> +       /* User cannot directly issue these operations to QTEE. */
> +       if (op == QCOMTEE_MSG_OBJECT_OP_RELEASE)
> +               return -EINVAL;
> +
> +       return qcomtee_object_do_invoke_internal(oic, object, op, u, result);
> +}
> +EXPORT_SYMBOL_GPL(qcomtee_object_do_invoke);
> diff --git a/drivers/tee/qcomtee/qcom_scm.c b/drivers/tee/qcomtee/qcom_scm.c
> new file mode 100644
> index 000000000000..38a3d080f86d
> --- /dev/null
> +++ b/drivers/tee/qcomtee/qcom_scm.c
> @@ -0,0 +1,38 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/firmware/qcom/qcom_scm.h>
> +
> +#include "qcomtee_private.h"
> +
> +int qcomtee_object_invoke_ctx_invoke(struct qcomtee_object_invoke_ctx *oic,
> +                                    int *result, u64 *res_type)
> +{
> +       phys_addr_t out_msg_paddr;
> +       phys_addr_t in_msg_paddr;
> +       int ret;
> +       u64 res;
> +
> +       tee_shm_get_pa(oic->out_shm, 0, &out_msg_paddr);
> +       tee_shm_get_pa(oic->in_shm, 0, &in_msg_paddr);
> +       if (!(oic->flags & QCOMTEE_OIC_FLAG_BUSY)) {
> +               /* Direct QTEE object invocation. */
> +               ret = qcom_scm_qtee_invoke_smc(in_msg_paddr, oic->in_msg.size,
> +                                              out_msg_paddr, oic->out_msg.size,
> +                                              &res, res_type);
> +       } else {
> +               /* Submit callback response. */
> +               ret = qcom_scm_qtee_callback_response(out_msg_paddr,
> +                                                     oic->out_msg.size,
> +                                                     &res, res_type);
> +       }
> +
> +       if (ret)
> +               pr_err("QTEE returned with %d.\n", ret);
> +       else
> +               *result = (int)res;
> +
> +       return ret;
> +}
> diff --git a/drivers/tee/qcomtee/qcomtee_msg.h b/drivers/tee/qcomtee/qcomtee_msg.h
> new file mode 100644
> index 000000000000..33a6b426153c
> --- /dev/null
> +++ b/drivers/tee/qcomtee/qcomtee_msg.h
> @@ -0,0 +1,239 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#ifndef QCOMTEE_MSG_H
> +#define QCOMTEE_MSG_H
> +
> +#include <linux/firmware/qcom/qcom_tee.h>
> +
> +/**
> + * DOC: ''Qualcomm TEE'' (QTEE) Transport Message
> + *
> + * There are two buffers shared with QTEE: inbound and outbound buffers.
> + * The inbound buffer is used for direct object invocation, and the outbound
> + * buffer is used to make a request from QTEE to the kernel; i.e., a callback
> + * request.
> + *
> + * The unused tail of the outbound buffer is also used for sending and
> + * receiving asynchronous messages. An asynchronous message is independent of
> + * the current object invocation (i.e., contents of the inbound buffer) or
> + * callback request (i.e., the head of the outbound buffer); see
> + * qcomtee_get_async_buffer(). It is used by endpoints (QTEE or kernel) as an
> + * optimization to reduce the number of context switches between the secure and
> + * non-secure worlds.
> + *
> + * For instance, QTEE never sends an explicit callback request to release an
> + * object in the kernel. Instead, it sends asynchronous release messages in the
> + * outbound buffer when QTEE returns from the previous direct object invocation,
> + * or appends asynchronous release messages after the current callback request.
> + *
> + * QTEE supports two types of arguments in a message: buffer and object
> + * arguments. Depending on the direction of data flow, they could be input
> + * buffer (IO) to QTEE, output buffer (OB) from QTEE, input object (IO) to QTEE,
> + * or output object (OO) from QTEE. Object arguments hold object IDs. Buffer
> + * arguments hold (offset, size) pairs into the inbound or outbound buffers.
> + *
> + * QTEE holds an object table for objects it hosts and exposes to the kernel.
> + * An object ID is an index to the object table in QTEE.
> + *
> + * For the direct object invocation message format in the inbound buffer, see
> + * &struct qcomtee_msg_object_invoke. For the callback request message format
> + * in the outbound buffer, see &struct qcomtee_msg_callback. For the message
> + * format for asynchronous messages in the outbound buffer, see
> + * &struct qcomtee_async_msg_hdr.
> + */
> +
> +/**
> + * define QCOMTEE_MSG_OBJECT_NS_BIT - Non-secure bit
> + *
> + * Object ID is a globally unique 32-bit number. IDs referencing objects
> + * in the kernel should have %QCOMTEE_MSG_OBJECT_NS_BIT set.
> + */
> +#define QCOMTEE_MSG_OBJECT_NS_BIT BIT(31)
> +
> +/* Static object IDs recognized by QTEE. */
> +#define QCOMTEE_MSG_OBJECT_NULL (0U)
> +#define QCOMTEE_MSG_OBJECT_ROOT (1U)
> +
> +/* Definitions from QTEE as part of the transport protocol. */
> +
> +/* qcomtee_msg_arg is an argument as recognized by QTEE. */
> +union qcomtee_msg_arg {
> +       struct {
> +               u32 offset;
> +               u32 size;
> +       } b;
> +       u32 o;
> +};
> +
> +/* BI and BO payloads in QTEE messages should be at 64-bit boundaries. */
> +#define qcomtee_msg_offset_align(o) ALIGN((o), sizeof(u64))
> +
> +/* Operations for objects are 32-bit. Transport uses the upper 16 bits. */
> +#define QCOMTEE_MSG_OBJECT_OP_MASK GENMASK(15, 0)
> +
> +/* Reserved Operation IDs sent to QTEE: */
> +/* QCOMTEE_MSG_OBJECT_OP_RELEASE - Reduces the refcount and releases the object.
> + * QCOMTEE_MSG_OBJECT_OP_RETAIN  - Increases the refcount.
> + *
> + * These operation IDs are valid for all objects.
> + */
> +
> +#define QCOMTEE_MSG_OBJECT_OP_RELEASE (QCOMTEE_MSG_OBJECT_OP_MASK - 0)
> +#define QCOMTEE_MSG_OBJECT_OP_RETAIN  (QCOMTEE_MSG_OBJECT_OP_MASK - 1)
> +
> +/* Subset of operations supported by QTEE root object. */
> +
> +#define QCOMTEE_ROOT_OP_REGISTER_WITH_CREDENTIALS 5
> +#define QCOMTEE_ROOT_OP_NOTIFY_DOMAIN_CHANGE 4
> +#define QCOMTEE_ROOT_OP_ADCI_ACCEPT 8
> +#define QCOMTEE_ROOT_OP_ADCI_SHUTDOWN 9
> +
> +/* Response types as returned from qcomtee_object_invoke_ctx_invoke(). */
> +
> +/* The message contains a callback request. */
> +#define QCOMTEE_RESULT_INBOUND_REQ_NEEDED 3
> +
> +/**
> + * struct qcomtee_msg_object_invoke - Direct object invocation message.
> + * @ctx: object ID hosted in QTEE.
> + * @op: operation for the object.
> + * @counts: number of different types of arguments in @args.
> + * @args: array of arguments.
> + *
> + * @counts consists of 4 * 4-bit fields. Bits 0 - 3 represent the number of
> + * input buffers, bits 4 - 7 represent the number of output buffers,
> + * bits 8 - 11 represent the number of input objects, and bits 12 - 15
> + * represent the number of output objects. The remaining bits should be zero.
> + *
> + * The maximum number of arguments of each type is defined by
> + * %QCOMTEE_ARGS_PER_TYPE.
> + */
> +struct qcomtee_msg_object_invoke {
> +       u32 cxt;
> +       u32 op;
> +       u32 counts;
> +       union qcomtee_msg_arg args[];
> +};
> +
> +/**
> + * struct qcomtee_msg_callback - Callback request message.
> + * @result: result of operation @op on the object referenced by @cxt.
> + * @cxt: object ID hosted in the kernel.
> + * @op: operation for the object.
> + * @counts: number of different types of arguments in @args.
> + * @args: array of arguments.
> + *
> + * For details of @counts, see &qcomtee_msg_object_invoke.counts.
> + */
> +struct qcomtee_msg_callback {
> +       u32 result;
> +       u32 cxt;
> +       u32 op;
> +       u32 counts;
> +       union qcomtee_msg_arg args[];
> +};
> +
> +/* Offset in the message for the beginning of the buffer argument's contents. */
> +#define qcomtee_msg_buffer_args(t, n) \
> +       qcomtee_msg_offset_align(struct_size_t(t, args, n))
> +/* Pointer to the beginning of a buffer argument's content at an offset. */
> +#define qcomtee_msg_offset_to_ptr(m, off) ((void *)&((char *)(m))[(off)])
> +
> +/* Some helpers to manage msg.counts. */
> +
> +#define QCOMTEE_MSG_NUM_IB(x) ((x) & 0xfU)
> +#define QCOMTEE_MSG_NUM_OB(x) (((x) >> 4) & 0xfU)
> +#define QCOMTEE_MSG_NUM_IO(x) (((x) >> 8) & 0xfU)
> +#define QCOMTEE_MSG_NUM_OO(x) (((x) >> 12) & 0xfU)
> +
> +#define QCOMTEE_MSG_IDX_IB(x) (0U)
> +#define QCOMTEE_MSG_IDX_OB(x) (QCOMTEE_MSG_IDX_IB(x) + QCOMTEE_MSG_NUM_IB(x))
> +#define QCOMTEE_MSG_IDX_IO(x) (QCOMTEE_MSG_IDX_OB(x) + QCOMTEE_MSG_NUM_OB(x))
> +#define QCOMTEE_MSG_IDX_OO(x) (QCOMTEE_MSG_IDX_IO(x) + QCOMTEE_MSG_NUM_IO(x))
> +
> +#define qcomtee_msg_for_each(i, c, type)    \
> +       for (i = QCOMTEE_MSG_IDX_##type(c); \
> +            i < (QCOMTEE_MSG_IDX_##type(c) + QCOMTEE_MSG_NUM_##type(c)); i++)
> +
> +#define qcomtee_msg_for_each_input_buffer(i, m) \
> +       qcomtee_msg_for_each(i, (m)->counts, IB)
> +#define qcomtee_msg_for_each_output_buffer(i, m) \
> +       qcomtee_msg_for_each(i, (m)->counts, OB)
> +#define qcomtee_msg_for_each_input_object(i, m) \
> +       qcomtee_msg_for_each(i, (m)->counts, IO)
> +#define qcomtee_msg_for_each_output_object(i, m) \
> +       qcomtee_msg_for_each(i, (m)->counts, OO)
> +
> +/* Sum of arguments in a message. */
> +#define qcomtee_msg_args(m) \
> +       (QCOMTEE_MSG_IDX_OO((m)->counts) + QCOMTEE_MSG_NUM_OO((m)->counts))
> +
> +static inline void qcomtee_msg_init(struct qcomtee_msg_object_invoke *msg,
> +                                   u32 cxt, u32 op, int in_buffer,
> +                                   int out_buffer, int in_object,
> +                                   int out_object)
> +{
> +       msg->counts |= (in_buffer & 0xfU);
> +       msg->counts |= ((out_buffer - in_buffer) & 0xfU) << 4;
> +       msg->counts |= ((in_object - out_buffer) & 0xfU) << 8;
> +       msg->counts |= ((out_object - in_object) & 0xfU) << 12;
> +       msg->cxt = cxt;
> +       msg->op = op;
> +}
> +
> +/* Generic error codes. */
> +#define QCOMTEE_MSG_OK                 0    /* non-specific success code. */
> +#define QCOMTEE_MSG_ERROR              1    /* non-specific error. */
> +#define QCOMTEE_MSG_ERROR_INVALID      2    /* unsupported/unrecognized request. */
> +#define QCOMTEE_MSG_ERROR_SIZE_IN      3    /* supplied buffer/string too large. */
> +#define QCOMTEE_MSG_ERROR_SIZE_OUT     4    /* supplied output buffer too small. */
> +#define QCOMTEE_MSG_ERROR_USERBASE     10   /* start of user-defined error range. */
> +
> +/* Transport layer error codes. */
> +#define QCOMTEE_MSG_ERROR_DEFUNCT      -90  /* object no longer exists. */
> +#define QCOMTEE_MSG_ERROR_ABORT                -91  /* calling thread must exit. */
> +#define QCOMTEE_MSG_ERROR_BADOBJ       -92  /* invalid object context. */
> +#define QCOMTEE_MSG_ERROR_NOSLOTS      -93  /* caller's object table full. */
> +#define QCOMTEE_MSG_ERROR_MAXARGS      -94  /* too many args. */
> +#define QCOMTEE_MSG_ERROR_MAXDATA      -95  /* buffers too large. */
> +#define QCOMTEE_MSG_ERROR_UNAVAIL      -96  /* the request could not be processed. */
> +#define QCOMTEE_MSG_ERROR_KMEM         -97  /* kernel out of memory. */
> +#define QCOMTEE_MSG_ERROR_REMOTE       -98  /* local method sent to remote object. */
> +#define QCOMTEE_MSG_ERROR_BUSY         -99  /* Object is busy. */
> +#define QCOMTEE_MSG_ERROR_TIMEOUT      -103 /* Call Back Object invocation timed out. */
> +
> +static inline void qcomtee_msg_set_result(struct qcomtee_msg_callback *cb_msg,
> +                                         int err)
> +{
> +       if (!err) {
> +               cb_msg->result = QCOMTEE_MSG_OK;
> +       } else if (err < 0) {
> +               /* If err < 0, then it is a transport error. */
> +               switch (err) {
> +               case -ENOMEM:
> +                       cb_msg->result = QCOMTEE_MSG_ERROR_KMEM;
> +                       break;
> +               case -ENODEV:
> +                       cb_msg->result = QCOMTEE_MSG_ERROR_DEFUNCT;
> +                       break;
> +               case -ENOSPC:
> +               case -EBUSY:
> +                       cb_msg->result = QCOMTEE_MSG_ERROR_BUSY;
> +                       break;
> +               case -EBADF:
> +               case -EINVAL:
> +                       cb_msg->result = QCOMTEE_MSG_ERROR_UNAVAIL;
> +                       break;
> +               default:
> +                       cb_msg->result = QCOMTEE_MSG_ERROR;
> +               }
> +       } else {
> +               /* If err > 0, then it is user defined error, pass it as is. */
> +               cb_msg->result = err;
> +       }
> +}
> +
> +#endif /* QCOMTEE_MSG_H */
> diff --git a/drivers/tee/qcomtee/qcomtee_private.h b/drivers/tee/qcomtee/qcomtee_private.h
> new file mode 100644
> index 000000000000..ab3acad40359
> --- /dev/null
> +++ b/drivers/tee/qcomtee/qcomtee_private.h
> @@ -0,0 +1,222 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#ifndef QCOMTEE_PRIVATE_H
> +#define QCOMTEE_PRIVATE_H
> +
> +#include <linux/firmware/qcom/qcom_tee.h>
> +#include <linux/kobject.h>
> +#include <linux/tee_core.h>
> +
> +#include "qcomtee_msg.h"
> +
> +/* Flags relating to object reference. */
> +#define QCOMTEE_OBJREF_FLAG_TEE BIT(0)
> +#define QCOMTEE_OBJREF_FLAG_USER BIT(1)
> +
> +/**
> + * struct qcomtee - Main service struct.
> + * @teedev: client device.
> + * @pool: shared memory pool.
> + * @ctx: driver private context.
> + * @wq: workqueue for QTEE async operations.
> + */
> +struct qcomtee {
> +       struct tee_device *teedev;
> +       struct tee_shm_pool *pool;
> +       struct tee_context *ctx;
> +       struct workqueue_struct *wq;
> +};
> +
> +struct qcomtee_object *qcomtee_idx_erase(u32 idx);
> +void qcomtee_qtee_object_free(struct qcomtee_object *object);
> +void qcomtee_fetch_async_reqs(struct qcomtee_object_invoke_ctx *oic);
> +void qcomtee_release_tee_object(struct qcomtee_object *object);
> +
> +struct tee_shm_pool *qcomtee_shm_pool_alloc(void);
> +void qcomtee_msg_buffers_free(struct qcomtee_object_invoke_ctx *oic);
> +int qcomtee_msg_buffers_alloc(struct qcomtee_object_invoke_ctx *oic,
> +                             struct qcomtee_arg *u);
> +
> +int qcomtee_object_invoke_ctx_invoke(struct qcomtee_object_invoke_ctx *oic,
> +                                    int *result, u64 *res_type);
> +
> +/**
> + * qcomtee_object_do_invoke_internal() - Submit an invocation for an object.
> + * @oic: context to use for the current invocation.
> + * @object: object being invoked.
> + * @op: requested operation on the object.
> + * @u: array of arguments for the current invocation.
> + * @result: result returned from QTEE.
> + *
> + * The caller is responsible for keeping track of the refcount for each
> + * object, including @object. On return, the caller loses ownership of all
> + * input objects of type %QCOMTEE_OBJECT_TYPE_CB.
> + *
> + * Return: On success, returns 0. On error, returns -EAGAIN if invocation
> + * failed and the user may retry the invocation, -ENODEV on fatal failure.
> + */
> +int qcomtee_object_do_invoke_internal(struct qcomtee_object_invoke_ctx *oic,
> +                                     struct qcomtee_object *object, u32 op,
> +                                     struct qcomtee_arg *u, int *result);
> +
> +/**
> + * struct qcomtee_context_data - Clients' or supplicants' context.
> + * @qtee_objects_idr: QTEE objects in this context.
> + * @qtee_lock: spinlock for @qtee_objects_idr.
> + * @reqs_idr: requests currently being processed in this context.
> + * @reqs_list: FIFO for requests.
> + * @reqs_lock: mutex for @reqs_idr, @reqs_list and request states.
> + * @req_c: completion used when the supplicant is waiting for requests.
> + * @released: state of this context.
> + */
> +struct qcomtee_context_data {
> +       struct idr qtee_objects_idr;
> +       /* Synchronize access to @qtee_objects_idr. */
> +       spinlock_t qtee_lock;
> +
> +       struct idr reqs_idr;
> +       struct list_head reqs_list;
> +       /* Synchronize access to @reqs_idr, @reqs_list and updating requests states. */
> +       struct mutex reqs_lock;
> +
> +       struct completion req_c;
> +
> +       int released;

Should this rather be a bool, or an enum depending on how many
different states it's supposed to have?

> +};
> +
> +/**
> + * qcomtee_context_add_qtee_object() - Add a QTEE object to the context.
> + * @param: TEE parameter representing @object.
> + * @object: QTEE object.
> + * @ctx: context to add the object.
> + *
> + * It assumes @object is %QCOMTEE_OBJECT_TYPE_TEE and the caller has already
> + * issued qcomtee_object_get() for @object.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_context_add_qtee_object(struct tee_param *param,
> +                                   struct qcomtee_object *object,
> +                                   struct tee_context *ctx);
> +
> +/* Retrieve the QTEE object added with qcomtee_context_add_qtee_object(). */
> +int qcomtee_context_find_qtee_object(struct qcomtee_object **object,
> +                                    struct tee_param *param,
> +                                    struct tee_context *ctx);
> +
> +/**
> + * qcomtee_context_del_qtee_object() - Delete a QTEE object from the context.
> + * @param: TEE parameter representing @object.
> + * @ctx: context for deleting the object.
> + *
> + * The @param has been initialized by qcomtee_context_add_qtee_object().
> + */
> +void qcomtee_context_del_qtee_object(struct tee_param *param,
> +                                    struct tee_context *ctx);
> +
> +/**
> + * qcomtee_objref_to_arg() - Convert OBJREF parameter to QTEE argument.
> + * @arg: QTEE argument.
> + * @param: TEE parameter.
> + * @ctx: context in which the conversion should happen.
> + *
> + * It assumes @param is an OBJREF.
> + * It does not set @arg.type; the caller should initialize it to a correct
> + * &enum qcomtee_arg_type value. It gets the object's refcount in @arg;
> + * the caller should manage to put it afterward.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_objref_to_arg(struct qcomtee_arg *arg, struct tee_param *param,
> +                         struct tee_context *ctx);
> +
> +/**
> + * qcomtee_objref_from_arg() - Convert QTEE argument to OBJREF param.
> + * @param: TEE parameter.
> + * @arg: QTEE argument.
> + * @ctx: context in which the conversion should happen.
> + *
> + * It assumes @arg is of %QCOMTEE_ARG_TYPE_IO or %QCOMTEE_ARG_TYPE_OO.
> + * It does not set @param.attr; the caller should initialize it to a
> + * correct type.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_objref_from_arg(struct tee_param *param, struct qcomtee_arg *arg,
> +                           struct tee_context *ctx);
> +
> +/* OBJECTS: */
> +
> +/* (1) User Object API. */
> +
> +/* Is it a user object? */
> +int is_qcomtee_user_object(struct qcomtee_object *object);
> +
> +/* Set the user object's 'notify on release' flag. */
> +void qcomtee_user_object_set_notify(struct qcomtee_object *object, bool notify);
> +
> +/* This is called when there are no more users for the ctxdata. */
> +void qcomtee_requests_destroy(struct qcomtee_context_data *ctxdata);
> +
> +/**
> + * qcomtee_user_param_to_object() - OBJREF parameter to &struct qcomtee_object.
> + * @object: object returned.
> + * @param: TEE parameter.
> + * @ctx: context in which the conversion should happen.
> + *
> + * @param is an OBJREF with %QCOMTEE_OBJREF_FLAG_USER flags.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_user_param_to_object(struct qcomtee_object **object,
> +                                struct tee_param *param,
> +                                struct tee_context *ctx);
> +
> +/* Reverse what qcomtee_user_param_to_object() does. */
> +int qcomtee_user_param_from_object(struct tee_param *param,
> +                                  struct qcomtee_object *object,
> +                                  struct tee_context *ctx);
> +
> +struct qcomtee_user_object_request_data {
> +       int id; /* ID assigned to the request. */
> +       u64 object_id; /* Object ID being invoked by QTEE. */
> +       u32 op; /* Requested operation on object. */
> +       int np; /* Number of parameters in the request.*/
> +};
> +
> +/**
> + * qcomtee_user_object_select() - Select a request for a user object.
> + * @ctx: context to look for a user object.
> + * @params: parameters for @op.
> + * @num_params: number of elements in the parameter array.
> + * @uaddr: user buffer for output UBUF parameters.
> + * @size: size of user buffer @uaddr.
> + * @data: information for the selected request.
> + *
> + * @params is filled along with @data for the selected request.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_user_object_select(struct tee_context *ctx,
> +                              struct tee_param *params, int num_params,
> +                              void __user *uaddr, size_t size,
> +                              struct qcomtee_user_object_request_data *data);
> +
> +/**
> + * qcomtee_user_object_submit() - Submit a response for a user object.
> + * @ctx: context to look for a user object.
> + * @params: returned parameters.
> + * @num_params: number of elements in the parameter array.
> + * @req_id: request ID for the response.
> + * @errno: result of user object invocation.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_user_object_submit(struct tee_context *ctx,
> +                              struct tee_param *params, int num_params,
> +                              int req_id, int errno);
> +
> +#endif /* QCOMTEE_PRIVATE_H */
> diff --git a/drivers/tee/qcomtee/release.c b/drivers/tee/qcomtee/release.c
> new file mode 100644
> index 000000000000..7d149ef3d26f
> --- /dev/null
> +++ b/drivers/tee/qcomtee/release.c
> @@ -0,0 +1,48 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include "qcomtee_private.h"
> +
> +static void qcomtee_destroy_user_object(struct work_struct *work)
> +{
> +       struct qcomtee_object *object;
> +       struct qcomtee *qcomtee;
> +       int ret, result;
> +
> +       static struct qcomtee_object_invoke_ctx oic;
> +       /* RELEASE does not require any argument. */
> +       static struct qcomtee_arg args[] = { { .type = QCOMTEE_ARG_TYPE_INV } };
> +
> +       object = container_of(work, struct qcomtee_object, work);
> +       qcomtee = tee_get_drvdata(object->info.qcomtee_async_ctx->teedev);
> +       /* Get the TEE context used for asynchronous operations. */
> +       oic.ctx = object->info.qcomtee_async_ctx;
> +
> +       ret = qcomtee_object_do_invoke_internal(&oic, object,
> +                                               QCOMTEE_MSG_OBJECT_OP_RELEASE,
> +                                               args, &result);
> +
> +       /* Is it safe to retry the release? */
> +       if (ret == -EAGAIN) {
> +               queue_work(qcomtee->wq, &object->work);
> +       } else {
> +               if (ret || result)
> +                       pr_err("%s: %s release failed, ret = %d (%x).\n",
> +                              __func__, qcomtee_object_name(object), ret,
> +                              result);
> +
> +               qcomtee_qtee_object_free(object);
> +       }
> +}
> +
> +/* qcomtee_release_tee_object puts object in release work queue. */
> +void qcomtee_release_tee_object(struct qcomtee_object *object)
> +{
> +       struct qcomtee *qcomtee =
> +               tee_get_drvdata(object->info.qcomtee_async_ctx->teedev);
> +
> +       INIT_WORK(&object->work, qcomtee_destroy_user_object);
> +       queue_work(qcomtee->wq, &object->work);
> +}
> diff --git a/drivers/tee/qcomtee/shm.c b/drivers/tee/qcomtee/shm.c
> new file mode 100644
> index 000000000000..998aabe96434
> --- /dev/null
> +++ b/drivers/tee/qcomtee/shm.c
> @@ -0,0 +1,149 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/firmware/qcom/qcom_tzmem.h>
> +#include <linux/mm.h>
> +
> +#include "qcomtee_msg.h"
> +#include "qcomtee_private.h"
> +
> +/**
> + * define MAX_OUTBOUND_BUFFER_SIZE - Maximum size of outbound buffers.
> + *
> + * The size of outbound buffer depends on QTEE callback requests.
> + * If an invocation requires any size larger than %MAX_OUTBOUND_BUFFER_SIZE,
> + * the user should probably use some other form of shared memory with QTEE.
> + */
> +#define MAX_OUTBOUND_BUFFER_SIZE SZ_4K
> +
> +/* Same as %MAX_OUTBOUND_BUFFER_SIZE but for inbound buffer. */
> +#define MAX_INBOUND_BUFFER_SIZE SZ_4M
> +
> +/**
> + * qcomtee_msg_buffers_alloc() - Allocate inbound and outbound buffers.
> + * @oic: context to use for the current invocation.
> + * @u: array of arguments for the current invocation.
> + *
> + * It calculates the size of inbound and outbound buffers based on the
> + * arguments in @u. It allocates the buffers from the teedev pool.
> + *
> + * Return: On success, returns 0. On error, returns < 0.
> + */
> +int qcomtee_msg_buffers_alloc(struct qcomtee_object_invoke_ctx *oic,
> +                             struct qcomtee_arg *u)
> +{
> +       struct tee_context *ctx = oic->ctx;
> +       struct tee_shm *shm;
> +       size_t size;
> +       int i;
> +
> +       /* Start offset in a message for buffer arguments. */
> +       size = qcomtee_msg_buffer_args(struct qcomtee_msg_object_invoke,
> +                                      qcomtee_args_len(u));
> +       if (size > MAX_INBOUND_BUFFER_SIZE)
> +               return -EINVAL;
> +
> +       /* Add size of IB arguments. */
> +       qcomtee_arg_for_each_input_buffer(i, u) {
> +               size = size_add(size, qcomtee_msg_offset_align(u[i].b.size));
> +               if (size > MAX_INBOUND_BUFFER_SIZE)
> +                       return -EINVAL;
> +       }
> +
> +       /* Add size of OB arguments. */
> +       qcomtee_arg_for_each_output_buffer(i, u) {
> +               size = size_add(size, qcomtee_msg_offset_align(u[i].b.size));
> +               if (size > MAX_INBOUND_BUFFER_SIZE)
> +                       return -EINVAL;
> +       }
> +
> +       shm = tee_shm_alloc_priv_buf(ctx, size);
> +       if (IS_ERR(shm))
> +               return PTR_ERR(shm);
> +
> +       /* Allocate inbound buffer. */
> +       oic->in_shm = shm;
> +       shm = tee_shm_alloc_priv_buf(ctx, MAX_OUTBOUND_BUFFER_SIZE);
> +       if (IS_ERR(shm)) {
> +               tee_shm_free(oic->in_shm);
> +
> +               return PTR_ERR(shm);
> +       }
> +       /* Allocate outbound buffer. */
> +       oic->out_shm = shm;
> +
> +       oic->in_msg.addr = tee_shm_get_va(oic->in_shm, 0);
> +       oic->in_msg.size = tee_shm_get_size(oic->in_shm);
> +       oic->out_msg.addr = tee_shm_get_va(oic->out_shm, 0);
> +       oic->out_msg.size = tee_shm_get_size(oic->out_shm);
> +       /* QTEE assume unused buffers are zeroed. */
> +       memzero_explicit(oic->in_msg.addr, oic->in_msg.size);
> +       memzero_explicit(oic->out_msg.addr, oic->out_msg.size);
> +
> +       return 0;
> +}
> +
> +void qcomtee_msg_buffers_free(struct qcomtee_object_invoke_ctx *oic)
> +{
> +       tee_shm_free(oic->in_shm);
> +       tee_shm_free(oic->out_shm);
> +}
> +
> +/* Dynamic shared memory pool based on tee_dyn_shm_alloc_helper(). */
> +
> +static int qcomtee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
> +                               struct page **pages, size_t num_pages,
> +                               unsigned long start)
> +{
> +       return qcom_tzmem_shm_bridge_create(shm->paddr, shm->size,
> +                                           &shm->sec_world_id);
> +}
> +
> +static int qcomtee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
> +{
> +       qcom_tzmem_shm_bridge_delete(shm->sec_world_id);
> +
> +       return 0;
> +}
> +
> +static int pool_op_alloc(struct tee_shm_pool *pool, struct tee_shm *shm,
> +                        size_t size, size_t align)
> +{
> +       if (!(shm->flags & TEE_SHM_PRIV))
> +               return -ENOMEM;
> +
> +       return tee_dyn_shm_alloc_helper(shm, size, align, qcomtee_shm_register);
> +}
> +
> +static void pool_op_free(struct tee_shm_pool *pool, struct tee_shm *shm)
> +{
> +       tee_dyn_shm_free_helper(shm, qcomtee_shm_unregister);
> +}
> +
> +static void pool_op_destroy_pool(struct tee_shm_pool *pool)
> +{
> +       kfree(pool);
> +}
> +
> +static const struct tee_shm_pool_ops pool_ops = {
> +       .alloc = pool_op_alloc,
> +       .free = pool_op_free,
> +       .destroy_pool = pool_op_destroy_pool,
> +};
> +
> +struct tee_shm_pool *qcomtee_shm_pool_alloc(void)
> +{
> +       struct tee_shm_pool *pool;
> +
> +       pool = kzalloc(sizeof(*pool), GFP_KERNEL);
> +       if (!pool)
> +               return ERR_PTR(-ENOMEM);
> +
> +       pool->ops = &pool_ops;
> +
> +       return pool;
> +}
> diff --git a/drivers/tee/qcomtee/user_obj.c b/drivers/tee/qcomtee/user_obj.c
> new file mode 100644
> index 000000000000..95d22e720de7
> --- /dev/null
> +++ b/drivers/tee/qcomtee/user_obj.c
> @@ -0,0 +1,710 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/slab.h>
> +#include "qcomtee_private.h"
> +
> +/**
> + * DOC: User Objects aka Supplicants
> + *
> + * Any userspace process with access to the TEE device file can behave as a
> + * supplicant by creating a user object. Any TEE parameter of type OBJREF with
> + * %QCOMTEE_OBJREF_FLAG_USER flag set is considered a user object.
> + *
> + * A supplicant uses qcomtee_user_object_select() (i.e. TEE_IOC_SUPPL_RECV) to
> + * receive a QTEE user object request and qcomtee_user_object_submit()
> + * (i.e. TEE_IOC_SUPPL_SEND) to submit a response. QTEE expects to receive the
> + * response, including OB and OO in a specific order in the message; parameters
> + * submitted with qcomtee_user_object_submit() should maintain this order.
> + */
> +
> +/**
> + * struct qcomtee_user_object - User object.
> + * @object: &struct qcomtee_object representing this user object.
> + * @ctx: context for which the user object is defined.
> + * @object_id: object ID in @ctx.
> + * @nor: notify on release.
> + *
> + * Any object managed in userspace is represented by this struct.
> + * If @nor is set, a notification message is sent back to userspace
> + * upon release.
> + */
> +struct qcomtee_user_object {
> +       struct qcomtee_object object;
> +       struct tee_context *ctx;
> +       u64 object_id;
> +       bool nor;
> +};
> +
> +#define to_qcomtee_user_object(o) \
> +       container_of((o), struct qcomtee_user_object, object)
> +
> +static struct qcomtee_object_operations qcomtee_user_object_ops;
> +
> +/* Is it a user object? */
> +int is_qcomtee_user_object(struct qcomtee_object *object)
> +{
> +       return object != NULL_QCOMTEE_OBJECT &&
> +              typeof_qcomtee_object(object) == QCOMTEE_OBJECT_TYPE_CB &&
> +              object->ops == &qcomtee_user_object_ops;
> +}
> +
> +/* Set the user object's 'notify on release' flag. */
> +void qcomtee_user_object_set_notify(struct qcomtee_object *object, bool notify)
> +{
> +       if (is_qcomtee_user_object(object))
> +               to_qcomtee_user_object(object)->nor = notify;
> +}
> +
> +/* Supplicant Requests: */
> +
> +/**
> + * enum qcomtee_req_state - Current state of request.
> + * @QCOMTEE_REQ_QUEUED: Request is waiting for supplicant.
> + * @QCOMTEE_REQ_PROCESSING: Request has been picked by the supplicant.
> + * @QCOMTEE_REQ_PROCESSED: Response has been submitted for the request.
> + */
> +enum qcomtee_req_state {
> +       QCOMTEE_REQ_QUEUED = 1,
> +       QCOMTEE_REQ_PROCESSING,
> +       QCOMTEE_REQ_PROCESSED,
> +};
> +
> +/* User requests sent to supplicants. */
> +struct qcomtee_ureq {
> +       enum qcomtee_req_state state;
> +
> +       /* User Request: */
> +       int req_id;
> +       u64 object_id;
> +       u32 op;
> +       struct qcomtee_arg *args;
> +       int errno;
> +
> +       struct list_head node;
> +       struct completion c; /* Completion for whoever wait. */
> +};
> +
> +/*
> + * Placeholder for a PROCESSING request in qcomtee_context.reqs_idr.
> + *
> + * If the thread that calls qcomtee_object_invoke() dies and the supplicant
> + * is processing the request, we replace the entry in qcomtee_context.reqs_idr
> + * with empty_ureq. This ensures that (1) the req_id remains busy and is not
> + * reused, and (2) the supplicant fails to submit the response and performs
> + * the necessary rollback.
> + */
> +static struct qcomtee_ureq empty_ureq = { .state = QCOMTEE_REQ_PROCESSING };
> +
> +/* Enqueue a user request for a context and assign a request ID. */
> +static int ureq_enqueue(struct qcomtee_context_data *ctxdata,
> +                       struct qcomtee_ureq *ureq)
> +{
> +       int ret;
> +
> +       guard(mutex)(&ctxdata->reqs_lock);
> +       /* Supplicant is dying. */
> +       if (ctxdata->released)
> +               return -ENODEV;
> +
> +       /* Allocate an ID and queue the request. */
> +       ret = idr_alloc(&ctxdata->reqs_idr, ureq, 0, 0, GFP_KERNEL);
> +       if (ret < 0)
> +               return ret;
> +
> +       ureq->req_id = ret;
> +       ureq->state = QCOMTEE_REQ_QUEUED;
> +       list_add_tail(&ureq->node, &ctxdata->reqs_list);
> +
> +       return 0;
> +}
> +
> +/**
> + * ureq_dequeue() - Dequeue a user request from a context.
> + * @ctxdata: context data for a context to dequeue the request.
> + * @req_id: ID of the request to be dequeued.
> + *
> + * It dequeues a user request and releases its request ID.
> + *
> + * Context: The caller should hold &qcomtee_context_data->reqs_lock.
> + * Return: Returns the user request associated with this ID; otherwise, NULL.
> + */
> +static struct qcomtee_ureq *ureq_dequeue(struct qcomtee_context_data *ctxdata,
> +                                        int req_id)
> +{
> +       struct qcomtee_ureq *ureq;
> +
> +       ureq = idr_remove(&ctxdata->reqs_idr, req_id);
> +       if (ureq == &empty_ureq || !ureq)
> +               return NULL;
> +
> +       list_del(&ureq->node);
> +
> +       return ureq;
> +}
> +
> +/**
> + * ureq_replace() - Replace a user request.
> + * @ctxdata: context data for a context to replace the request.
> + * @ureq: request to be replaced.
> + * @ureq_new: request to replace it with.
> + *
> + * Context: The caller should hold &qcomtee_context_data->reqs_lock.
> + */
> +static void ureq_replace(struct qcomtee_context_data *ctxdata,
> +                        struct qcomtee_ureq *ureq,
> +                        struct qcomtee_ureq *ureq_new)
> +{
> +       idr_replace(&ctxdata->reqs_idr, ureq_new, ureq->req_id);
> +       /* ureq does not have a valid ID anymore; remove it from the queue. */
> +       list_del(&ureq->node);
> +}
> +
> +/**
> + * ureq_select() - Select the next request in a context.
> + * @ctxdata: context data for a context to pop a request.
> + * @ubuf_size: size of the available buffer for UBUF parameters.
> + * @num_params: number of entries for the TEE parameter array.
> + *
> + * It checks if @num_params is large enough to fit the next request arguments.
> + * It checks if @ubuf_size is large enough to fit IB buffer arguments.
> + *
> + * Context: The caller should hold &qcomtee_context_data->reqs_lock.
> + * Return: On success, returns a request;
> + *         on failure, returns NULL and ERR_PTR.
> + */
> +static struct qcomtee_ureq *ureq_select(struct qcomtee_context_data *ctxdata,
> +                                       size_t ubuf_size, int num_params)
> +{
> +       struct qcomtee_ureq *req, *ureq = NULL;
> +       struct qcomtee_arg *u;
> +       int i;
> +
> +       /* Find the a queued request. */
> +       list_for_each_entry(req, &ctxdata->reqs_list, node) {
> +               if (req->state == QCOMTEE_REQ_QUEUED) {
> +                       ureq = req;
> +                       break;
> +               }
> +       }
> +
> +       if (!ureq)
> +               return NULL;
> +
> +       u = ureq->args;
> +       /* (1) Is there enough TEE parameters? */
> +       if (num_params < qcomtee_args_len(u))
> +               return ERR_PTR(-EINVAL);
> +       /* (2) Is there enough space to pass input buffers? */
> +       qcomtee_arg_for_each_input_buffer(i, u) {
> +               ubuf_size = size_sub(ubuf_size, u[i].b.size);
> +               if (ubuf_size == SIZE_MAX)
> +                       return ERR_PTR(-EINVAL);
> +
> +               ubuf_size = round_down(ubuf_size, 8);
> +       }
> +
> +       return ureq;
> +}
> +
> +/* This is called when there are no more users for the ctxdata. */
> +void qcomtee_requests_destroy(struct qcomtee_context_data *ctxdata)
> +{
> +       struct qcomtee_ureq *req, *ureq;
> +
> +       guard(mutex)(&ctxdata->reqs_lock);
> +       /* So ureq_enqueue() refuses new requests from QTEE. */
> +       ctxdata->released = 1;

Magic number?

> +
> +       list_for_each_entry_safe(ureq, req, &ctxdata->reqs_list, node) {
> +               ureq_dequeue(ctxdata, ureq->req_id);
> +
> +               /*
> +                * Terminate requests.
> +                * Depending on who enqueues the ureq, there may be someone
> +                * waiting for the response or not:
> +                */
> +               if (ureq->op != QCOMTEE_MSG_OBJECT_OP_RELEASE) {
> +                       /* (1) enqueued by qcomtee_user_object_dispatch(). */
> +                       ureq->state = QCOMTEE_REQ_PROCESSED;
> +                       ureq->errno = -ENODEV;
> +
> +                       complete(&ureq->c);
> +               } else {
> +                       /* (2) enqueued by qcomtee_user_object_release(). */
> +                       kfree(ureq);
> +               }
> +       }
> +}
> +
> +/* User Object API. */
> +
> +/* User object dispatcher. */
> +static int qcomtee_user_object_dispatch(struct qcomtee_object_invoke_ctx *oic,
> +                                       struct qcomtee_object *object, u32 op,
> +                                       struct qcomtee_arg *args)
> +{
> +       struct qcomtee_user_object *uo = to_qcomtee_user_object(object);
> +       struct qcomtee_context_data *ctxdata = uo->ctx->data;
> +       struct qcomtee_ureq *ureq __free(kfree) = NULL;
> +       int errno;
> +
> +       ureq = kzalloc(sizeof(*ureq), GFP_KERNEL);
> +       if (!ureq)
> +               return -ENOMEM;
> +
> +       init_completion(&ureq->c);
> +       ureq->object_id = uo->object_id;
> +       ureq->op = op;
> +       ureq->args = args;
> +
> +       /* Queue the request. */
> +       if (ureq_enqueue(ctxdata, ureq))
> +               return -ENODEV;
> +
> +       /* Wakeup supplicant to process it. */
> +       complete(&ctxdata->req_c);
> +
> +       /*
> +        * Wait for the supplicant to process the request.
> +        *
> +        * The supplicant is expected to process the request in a timely manner.
> +        * We wait as KILLABLE in case the supplicant and invoke thread are
> +        * both running from the same user process; otherwise, the process
> +        * will be stuck on a fatal signal.
> +        */
> +       if (!wait_for_completion_state(&ureq->c,
> +                                      TASK_KILLABLE | TASK_FREEZABLE)) {
> +               errno = ureq->errno;
> +               /* On success, notify() frees the request. */
> +               if (!errno)
> +                       oic->data = no_free_ptr(ureq);
> +       } else {
> +               enum qcomtee_req_state prev_state;
> +
> +               errno = -ENODEV;
> +
> +               scoped_guard(mutex, &ctxdata->reqs_lock) {
> +                       prev_state = ureq->state;
> +
> +                       /* Replace with empty_ureq to keep req_id reserved. */
> +                       if (prev_state == QCOMTEE_REQ_PROCESSING)
> +                               ureq_replace(ctxdata, ureq, &empty_ureq);
> +
> +                       /* Remove as supplicant has never seen this request. */
> +                       else if (prev_state == QCOMTEE_REQ_QUEUED)
> +                               ureq_dequeue(ctxdata, ureq->req_id);
> +               }
> +
> +               /* Supplicant did some work, we should not discard it. */
> +               if (prev_state == QCOMTEE_REQ_PROCESSED) {
> +                       errno = ureq->errno;
> +                       /* On success, notify() frees the request. */
> +                       if (!errno)
> +                               oic->data = no_free_ptr(ureq);
> +               }
> +       }
> +
> +       return errno;
> +}
> +
> +/* This is called after submitting the dispatcher response. */
> +static void qcomtee_user_object_notify(struct qcomtee_object_invoke_ctx *oic,
> +                                      struct qcomtee_object *unused_object,
> +                                      int err)
> +{
> +       struct qcomtee_ureq *ureq = oic->data;
> +       struct qcomtee_arg *u = ureq->args;
> +       int i;
> +
> +       qcomtee_arg_for_each_output_object(i, u) {
> +               /*
> +                * If err, there was a transport issue, and QTEE did not
> +                * receive the response for the dispatcher. Release the callback
> +                * object created for QTEE, in addition to the copies of
> +                * objects kept for the drivers.
> +                */
> +               if (err &&
> +                   (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB))
> +                       qcomtee_object_put(u[i].o);
> +               qcomtee_object_put(u[i].o);
> +       }
> +
> +       kfree(ureq);
> +}
> +
> +static void qcomtee_user_object_release(struct qcomtee_object *object)
> +{
> +       struct qcomtee_user_object *uo = to_qcomtee_user_object(object);
> +       struct qcomtee_context_data *ctxdata = uo->ctx->data;
> +       struct qcomtee_ureq *ureq;
> +
> +       /* RELEASE does not require any argument. */
> +       static struct qcomtee_arg args[] = { { .type = QCOMTEE_ARG_TYPE_INV } };
> +
> +       if (!uo->nor)
> +               goto out_no_notify;
> +
> +       ureq = kzalloc(sizeof(*ureq), GFP_KERNEL);
> +       if (!ureq)
> +               goto out_no_notify;
> +
> +       /* QUEUE a release request: */
> +       ureq->object_id = uo->object_id;
> +       ureq->op = QCOMTEE_MSG_OBJECT_OP_RELEASE;
> +       ureq->args = args;
> +       if (ureq_enqueue(ctxdata, ureq)) {
> +               kfree(ureq);
> +               /* Ignore the notification if it cannot be queued. */
> +               goto out_no_notify;
> +       }
> +
> +       complete(&ctxdata->req_c);
> +
> +out_no_notify:
> +       teedev_ctx_put(uo->ctx);
> +       kfree(uo);
> +}
> +
> +static struct qcomtee_object_operations qcomtee_user_object_ops = {
> +       .release = qcomtee_user_object_release,
> +       .notify = qcomtee_user_object_notify,
> +       .dispatch = qcomtee_user_object_dispatch,
> +};
> +
> +/**
> + * qcomtee_user_param_to_object() - OBJREF parameter to &struct qcomtee_object.
> + * @object: object returned.
> + * @param: TEE parameter.
> + * @ctx: context in which the conversion should happen.
> + *
> + * @param is an OBJREF with %QCOMTEE_OBJREF_FLAG_USER flags.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_user_param_to_object(struct qcomtee_object **object,
> +                                struct tee_param *param,
> +                                struct tee_context *ctx)
> +{
> +       struct qcomtee_user_object *user_object __free(kfree) = NULL;
> +       int err;
> +
> +       user_object = kzalloc(sizeof(*user_object), GFP_KERNEL);
> +       if (!user_object)
> +               return -ENOMEM;
> +
> +       user_object->ctx = ctx;
> +       user_object->object_id = param->u.objref.id;
> +       /* By default, always notify userspace upon release. */
> +       user_object->nor = true;
> +       err = qcomtee_object_user_init(&user_object->object,
> +                                      QCOMTEE_OBJECT_TYPE_CB,
> +                                      &qcomtee_user_object_ops, "uo-%lu",
> +                                      param->u.objref.id);
> +       if (err)
> +               return err;
> +
> +       teedev_ctx_get(ctx);
> +
> +       *object = &no_free_ptr(user_object)->object;
> +
> +       return 0;
> +}
> +
> +/* Reverse what qcomtee_user_param_to_object() does. */
> +int qcomtee_user_param_from_object(struct tee_param *param,
> +                                  struct qcomtee_object *object,
> +                                  struct tee_context *ctx)
> +{
> +       struct qcomtee_user_object *uo;
> +
> +       uo = to_qcomtee_user_object(object);
> +       /* Ensure the object is in the same context as the caller. */
> +       if (uo->ctx != ctx)
> +               return -EINVAL;
> +
> +       param->u.objref.id = uo->object_id;
> +       param->u.objref.flags = QCOMTEE_OBJREF_FLAG_USER;
> +
> +       /* User objects are valid in userspace; do not keep a copy. */
> +       qcomtee_object_put(object);
> +
> +       return 0;
> +}
> +
> +/**
> + * qcomtee_cb_params_from_args() - Convert QTEE arguments to TEE parameters.
> + * @params: TEE parameters.
> + * @u: QTEE arguments.
> + * @num_params: number of elements in the parameter array.
> + * @ubuf_addr: user buffer for arguments of type %QCOMTEE_ARG_TYPE_IB.
> + * @ubuf_size: size of the user buffer.
> + * @ctx: context in which the conversion should happen.
> + *
> + * It expects @params to have enough entries for @u. Entries in @params are of
> + * %TEE_IOCTL_PARAM_ATTR_TYPE_NONE.
> + *
> + * Return: On success, returns the number of input parameters;
> + *         on failure, returns < 0.
> + */
> +static int qcomtee_cb_params_from_args(struct tee_param *params,
> +                                      struct qcomtee_arg *u, int num_params,
> +                                      void __user *ubuf_addr, size_t ubuf_size,
> +                                      struct tee_context *ctx)
> +{
> +       int i, np;
> +       void __user *uaddr;
> +
> +       qcomtee_arg_for_each(i, u) {
> +               switch (u[i].type) {
> +               case QCOMTEE_ARG_TYPE_IB:
> +                       params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT;
> +
> +                       /* Underflow already checked in ureq_select(). */
> +                       ubuf_size = round_down(ubuf_size - u[i].b.size, 8);
> +                       uaddr = (void *__user)(ubuf_addr + ubuf_size);
> +
> +                       params[i].u.ubuf.uaddr = uaddr;
> +                       params[i].u.ubuf.size = u[i].b.size;
> +                       if (copy_to_user(params[i].u.ubuf.uaddr, u[i].b.addr,
> +                                        u[i].b.size))
> +                               goto out_failed;
> +
> +                       break;
> +               case QCOMTEE_ARG_TYPE_OB:
> +                       params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT;
> +                       /* Let the user knows the maximum size we expect. */
> +                       params[i].u.ubuf.size = u[i].b.size;
> +
> +                       break;
> +               case QCOMTEE_ARG_TYPE_IO:
> +                       params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT;
> +                       if (qcomtee_objref_from_arg(&params[i], &u[i], ctx))
> +                               goto out_failed;
> +
> +                       break;
> +               case QCOMTEE_ARG_TYPE_OO:
> +                       params[i].attr =
> +                               TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT;
> +
> +                       break;
> +               default: /* Never get here! */
> +                       goto out_failed;
> +               }
> +       }
> +
> +       return i;
> +
> +out_failed:
> +       /* Undo qcomtee_objref_from_arg(). */
> +       for (np = i; np >= 0; np--) {
> +               if (params[np].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT)
> +                       qcomtee_context_del_qtee_object(&params[np], ctx);
> +       }
> +
> +       /* Release any IO objects not processed. */
> +       for (; u[i].type; i++) {
> +               if (u[i].type == QCOMTEE_ARG_TYPE_IO)
> +                       qcomtee_object_put(u[i].o);
> +       }
> +
> +       return -EINVAL;
> +}
> +
> +/**
> + * qcomtee_cb_params_to_args() - Convert TEE parameters to QTEE arguments.
> + * @u: QTEE arguments.
> + * @params: TEE parameters.
> + * @num_params: number of elements in the parameter array.
> + * @ctx: context in which the conversion should happen.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +static int qcomtee_cb_params_to_args(struct qcomtee_arg *u,
> +                                    struct tee_param *params, int num_params,
> +                                    struct tee_context *ctx)
> +{
> +       int i;
> +
> +       qcomtee_arg_for_each(i, u) {
> +               switch (u[i].type) {
> +               case QCOMTEE_ARG_TYPE_IB:
> +                       if (params[i].attr !=
> +                           TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT)
> +                               goto out_failed;
> +
> +                       break;
> +               case QCOMTEE_ARG_TYPE_OB:
> +                       if (params[i].attr !=
> +                           TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT)
> +                               goto out_failed;
> +
> +                       /* Client can not send more data than requested. */
> +                       if (params[i].u.ubuf.size > u[i].b.size)
> +                               goto out_failed;
> +
> +                       if (copy_from_user(u[i].b.addr, params[i].u.ubuf.uaddr,
> +                                          params[i].u.ubuf.size))
> +                               goto out_failed;
> +
> +                       u[i].b.size = params[i].u.ubuf.size;
> +
> +                       break;
> +               case QCOMTEE_ARG_TYPE_IO:
> +                       if (params[i].attr !=
> +                           TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT)
> +                               goto out_failed;
> +
> +                       break;
> +               case QCOMTEE_ARG_TYPE_OO:
> +                       if (params[i].attr !=
> +                           TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT)
> +                               goto out_failed;
> +
> +                       if (qcomtee_objref_to_arg(&u[i], &params[i], ctx))
> +                               goto out_failed;
> +
> +                       break;
> +               default: /* Never get here! */
> +                       goto out_failed;
> +               }
> +       }
> +
> +       return 0;
> +
> +out_failed:
> +       /* Undo qcomtee_objref_to_arg(). */
> +       for (i--; i >= 0; i--) {
> +               if (u[i].type != QCOMTEE_ARG_TYPE_OO)
> +                       continue;
> +
> +               qcomtee_user_object_set_notify(u[i].o, false);
> +               if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)
> +                       qcomtee_object_put(u[i].o);
> +
> +               qcomtee_object_put(u[i].o);
> +       }
> +
> +       return -EINVAL;
> +}
> +
> +/**
> + * qcomtee_user_object_select() - Select a request for a user object.
> + * @ctx: context to look for a user object.
> + * @params: parameters for @op.
> + * @num_params: number of elements in the parameter array.
> + * @uaddr: user buffer for output UBUF parameters.
> + * @size: size of user buffer @uaddr.
> + * @data: information for the selected request.
> + *
> + * @params is filled along with @data for the selected request.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_user_object_select(struct tee_context *ctx,
> +                              struct tee_param *params, int num_params,
> +                              void __user *uaddr, size_t size,
> +                              struct qcomtee_user_object_request_data *data)
> +{
> +       struct qcomtee_context_data *ctxdata = ctx->data;
> +       struct qcomtee_ureq *ureq;
> +       int ret;
> +
> +       while (1) {
> +               scoped_guard(mutex, &ctxdata->reqs_lock) {
> +                       ureq = ureq_select(ctxdata, size, num_params);
> +                       if (!ureq)
> +                               goto wait_for_request;
> +
> +                       if (IS_ERR(ureq))
> +                               return PTR_ERR(ureq);
> +
> +                       /* Processing the request 'QUEUED -> PROCESSING'. */
> +                       ureq->state = QCOMTEE_REQ_PROCESSING;
> +
> +                       /* ''Prepare user request:'' */
> +                       data->id = ureq->req_id;
> +                       data->object_id = ureq->object_id;
> +                       data->op = ureq->op;
> +                       ret = qcomtee_cb_params_from_args(params, ureq->args,
> +                                                         num_params, uaddr,
> +                                                         size, ctx);
> +                       if (ret >= 0)
> +                               goto done_request;
> +
> +                       /* Something is wrong with the request. */
> +
> +                       ureq_dequeue(ctxdata, data->id);
> +                       /* Send error to QTEE. */
> +                       ureq->state = QCOMTEE_REQ_PROCESSED;
> +                       ureq->errno = ret;
> +
> +                       complete(&ureq->c);
> +               }
> +
> +               continue;
> +wait_for_request:
> +               /* Wait for a new QUEUED request. */
> +               if (wait_for_completion_interruptible(&ctxdata->req_c))
> +                       return -ERESTARTSYS;
> +       }
> +
> +done_request:
> +       /* No one is waiting for the response. */
> +       if (data->op == QCOMTEE_MSG_OBJECT_OP_RELEASE) {
> +               scoped_guard(mutex, &ctxdata->reqs_lock)
> +                       ureq_dequeue(ctxdata, data->id);
> +               kfree(ureq);
> +       }
> +
> +       data->np = ret;
> +
> +       return 0;
> +}
> +
> +/**
> + * qcomtee_user_object_submit() - Submit a response for a user object.
> + * @ctx: context to look for a user object.
> + * @params: returned parameters.
> + * @num_params: number of elements in the parameter array.
> + * @req_id: request ID for the response.
> + * @errno: result of user object invocation.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_user_object_submit(struct tee_context *ctx,
> +                              struct tee_param *params, int num_params,
> +                              int req_id, int errno)
> +{
> +       struct qcomtee_context_data *ctxdata = ctx->data;
> +       struct qcomtee_ureq *ureq;
> +
> +       guard(mutex)(&ctxdata->reqs_lock);
> +
> +       ureq = ureq_dequeue(ctxdata, req_id);
> +       if (!ureq)
> +               return -EINVAL;
> +
> +       ureq->state = QCOMTEE_REQ_PROCESSED;
> +
> +       if (!errno)
> +               ureq->errno = qcomtee_cb_params_to_args(ureq->args, params,
> +                                                       num_params, ctx);
> +       else
> +               ureq->errno = errno;
> +
> +       /* Return errno if qcomtee_cb_params_to_args() failed; otherwise 0. */
> +       if (!errno && ureq->errno)
> +               errno = ureq->errno;
> +       else
> +               errno = 0;
> +
> +       /* Send result to QTEE. */
> +       complete(&ureq->c);
> +
> +       return errno;
> +}
> diff --git a/include/linux/firmware/qcom/qcom_tee.h b/include/linux/firmware/qcom/qcom_tee.h
> new file mode 100644
> index 000000000000..1d9f9bc320fe
> --- /dev/null
> +++ b/include/linux/firmware/qcom/qcom_tee.h
> @@ -0,0 +1,302 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/* Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#ifndef __QCOM_TEE_H
> +#define __QCOM_TEE_H
> +
> +#include <linux/completion.h>
> +#include <linux/kref.h>
> +#include <linux/slab.h>
> +#include <linux/workqueue.h>
> +
> +struct qcomtee_object;
> +
> +/**
> + * DOC: Overview
> + *
> + * qcomtee_object provides object refcounting, ID allocation for objects hosted
> + * in the kernel, and necessary message marshaling for Qualcomm TEE (QTEE).
> + *
> + * To invoke an object in QTEE, the user calls qcomtee_object_do_invoke()
> + * while passing an instance of &struct qcomtee_object and the requested
> + * operation + arguments.
> + *
> + * After boot, QTEE provides a static object %ROOT_QCOMTEE_OBJECT (type of
> + * %QCOMTEE_OBJECT_TYPE_ROOT). The root object is invoked to pass the user's
> + * credentials and obtain other instances of &struct qcomtee_object (type of
> + * %QCOMTEE_OBJECT_TYPE_TEE) that represent services and TAs in QTEE;
> + * see &enum qcomtee_object_type.
> + *
> + * The objects received from QTEE are refcounted. So the owner of these objects
> + * can issue qcomtee_object_get() to increase the refcount and pass objects
> + * to other clients, or issue qcomtee_object_put() to decrease the refcount
> + * and release the resources in QTEE.
> + *
> + * The kernel can host services accessible to QTEE. A driver should embed
> + * an instance of &struct qcomtee_object in the struct it wants to export to
> + * QTEE (this is called a callback object). It issues qcomtee_object_user_init()
> + * to set the dispatch() operation for the callback object and set its type
> + * to %QCOMTEE_OBJECT_TYPE_CB.
> + *
> + * core.c holds an object table for callback objects. An object ID is assigned
> + * to each callback object, which is an index to the object table. QTEE uses
> + * these IDs to reference or invoke callback objects.
> + *
> + * If QTEE invokes a callback object in the kernel, the dispatch() operation is
> + * called in the context of the thread that originally called
> + * qcomtee_object_do_invoke().
> + */
> +
> +/**
> + * enum qcomtee_object_type - Object types.
> + * @QCOMTEE_OBJECT_TYPE_TEE: object hosted on QTEE.
> + * @QCOMTEE_OBJECT_TYPE_CB: object hosted on kernel.
> + * @QCOMTEE_OBJECT_TYPE_ROOT: 'primordial' object.
> + * @QCOMTEE_OBJECT_TYPE_NULL: NULL object.
> + *
> + * The primordial object is used for bootstrapping the IPC connection between
> + * the kernel and QTEE. It is invoked by the kernel when it wants to get a
> + * 'client env'.
> + */
> +enum qcomtee_object_type {
> +       QCOMTEE_OBJECT_TYPE_TEE,
> +       QCOMTEE_OBJECT_TYPE_CB,
> +       QCOMTEE_OBJECT_TYPE_ROOT,
> +       QCOMTEE_OBJECT_TYPE_NULL,
> +};
> +
> +/**
> + * enum qcomtee_arg_type - Type of QTEE argument.
> + * @QCOMTEE_ARG_TYPE_INV: invalid type.
> + * @QCOMTEE_ARG_TYPE_OB: output buffer (OB).
> + * @QCOMTEE_ARG_TYPE_OO: output object (OO).
> + * @QCOMTEE_ARG_TYPE_IB: input buffer (IB).
> + * @QCOMTEE_ARG_TYPE_IO: input object (IO).
> + *
> + * Use the invalid type to specify the end of the argument array.
> + */
> +enum qcomtee_arg_type {
> +       QCOMTEE_ARG_TYPE_INV = 0,
> +       QCOMTEE_ARG_TYPE_OB,
> +       QCOMTEE_ARG_TYPE_OO,
> +       QCOMTEE_ARG_TYPE_IB,
> +       QCOMTEE_ARG_TYPE_IO,
> +       QCOMTEE_ARG_TYPE_NR,
> +};
> +
> +/**
> + * define QCOMTEE_ARGS_PER_TYPE - Maximum arguments of a specific type.
> + *
> + * The QTEE transport protocol limits the maximum number of arguments of
> + * a specific type (i.e., IB, OB, IO, and OO).
> + */
> +#define QCOMTEE_ARGS_PER_TYPE 16
> +
> +/* Maximum arguments that can fit in a QTEE message, ignoring the type. */
> +#define QCOMTEE_ARGS_MAX (QCOMTEE_ARGS_PER_TYPE * (QCOMTEE_ARG_TYPE_NR - 1))
> +
> +struct qcomtee_buffer {
> +       union {
> +               void *addr;
> +               void __user *uaddr;
> +       };
> +       size_t size;
> +};
> +
> +/**
> + * struct qcomtee_arg - Argument for QTEE object invocation.
> + * @type: type of argument as &enum qcomtee_arg_type.
> + * @flags: extra flags.
> + * @b: address and size if the type of argument is a buffer.
> + * @o: object instance if the type of argument is an object.
> + *
> + * &qcomtee_arg.flags only accepts %QCOMTEE_ARG_FLAGS_UADDR for now, which
> + * states that &qcomtee_arg.b contains a userspace address in uaddr.
> + */
> +struct qcomtee_arg {
> +       enum qcomtee_arg_type type;
> +/* 'b.uaddr' holds a __user address. */
> +#define QCOMTEE_ARG_FLAGS_UADDR BIT(0)
> +       unsigned int flags;
> +       union {
> +               struct qcomtee_buffer b;
> +               struct qcomtee_object *o;
> +       };
> +};
> +
> +static inline int qcomtee_args_len(struct qcomtee_arg *args)
> +{
> +       int i = 0;
> +
> +       while (args[i].type != QCOMTEE_ARG_TYPE_INV)
> +               i++;
> +       return i;
> +}
> +
> +/* Context is busy (callback is in progress). */
> +#define QCOMTEE_OIC_FLAG_BUSY BIT(1)
> +/* Context needs to notify the current object. */
> +#define QCOMTEE_OIC_FLAG_NOTIFY BIT(2)
> +/* Context has shared state with QTEE. */
> +#define QCOMTEE_OIC_FLAG_SHARED BIT(3)
> +
> +struct qcomtee_object_invoke_ctx {
> +       /* TEE context for this invocation. */
> +       struct tee_context *ctx;
> +       unsigned long flags;
> +       int errno;
> +
> +       /* Current object invoked in this callback context. */
> +       struct qcomtee_object *object;
> +
> +       /* Dispatcher argument array (+1 for ending QCOMTEE_ARG_TYPE_INV). */
> +       struct qcomtee_arg u[QCOMTEE_ARGS_MAX + 1];
> +
> +       /* Inbound and Outbound buffers shared with QTEE. */
> +       struct qcomtee_buffer in_msg; /* Inbound buffer.  */
> +       struct qcomtee_buffer out_msg; /* Outbound buffer. */
> +       struct tee_shm *in_shm; /* TEE shm allocated for inbound buffer. */
> +       struct tee_shm *out_shm; /* TEE shm allocated for outbound buffer. */
> +
> +       /* Extra data attached to this context. */
> +       void *data;
> +};
> +
> +static inline struct qcomtee_object_invoke_ctx *
> +qcomtee_object_invoke_ctx_alloc(struct tee_context *ctx)
> +{
> +       struct qcomtee_object_invoke_ctx *oic;
> +
> +       oic = kzalloc(sizeof(*oic), GFP_KERNEL);
> +       if (oic)
> +               oic->ctx = ctx;
> +       return oic;
> +}
> +
> +/**
> + * qcomtee_object_do_invoke() - Submit an invocation for an object.
> + * @oic: context to use for the current invocation.
> + * @object: object being invoked.
> + * @op: requested operation on the object.
> + * @u: array of arguments for the current invocation.
> + * @result: result returned from QTEE.
> + *
> + * The caller is responsible for keeping track of the refcount for each object,
> + * including @object. On return, the caller loses ownership of all input
> + * objects of type %QCOMTEE_OBJECT_TYPE_CB.
> + *
> + * @object can be of %QCOMTEE_OBJECT_TYPE_ROOT or %QCOMTEE_OBJECT_TYPE_TEE.
> + *
> + * Return: On success, returns 0. On error, returns -EAGAIN if invocation
> + * failed and the user may retry the invocation, -ENODEV on fatal failure.
> + */
> +int qcomtee_object_do_invoke(struct qcomtee_object_invoke_ctx *oic,
> +                            struct qcomtee_object *object, u32 op,
> +                            struct qcomtee_arg *u, int *result);
> +
> +/**
> + * struct qcomtee_object_operations - Callback object operations.
> + * @release: release the object if QTEE is not using it.
> + * @dispatch: dispatch the operation requested by QTEE.
> + * @notify: report the status of any pending response submitted by @dispatch.
> + */
> +struct qcomtee_object_operations {
> +       void (*release)(struct qcomtee_object *object);
> +       int (*dispatch)(struct qcomtee_object_invoke_ctx *oic,
> +                       struct qcomtee_object *object, u32 op,
> +                       struct qcomtee_arg *args);
> +       void (*notify)(struct qcomtee_object_invoke_ctx *oic,
> +                      struct qcomtee_object *object, int err);
> +};
> +
> +/**
> + * struct qcomtee_object - QTEE or kernel object.
> + * @name: object name.
> + * @refcount: reference counter.
> + * @object_type: object type as &enum qcomtee_object_type.
> + * @info: extra information for the object.
> + * @ops: callback operations for objects of type %QCOMTEE_OBJECT_TYPE_CB.
> + * @work: work for async operations on the object.
> + *
> + * @work is used for releasing objects of %QCOMTEE_OBJECT_TYPE_TEE type.
> + */
> +struct qcomtee_object {
> +       const char *name;
> +       struct kref refcount;
> +
> +       enum qcomtee_object_type object_type;
> +       struct object_info {
> +               unsigned long qtee_id;
> +               /* TEE context for QTEE object async requests. */
> +               struct tee_context *qcomtee_async_ctx;
> +       } info;
> +
> +       struct qcomtee_object_operations *ops;
> +       struct work_struct work;
> +};
> +
> +/* Static instances of qcomtee_object objects. */
> +#define NULL_QCOMTEE_OBJECT ((struct qcomtee_object *)(0))
> +extern struct qcomtee_object qcomtee_object_root;
> +#define ROOT_QCOMTEE_OBJECT (&qcomtee_object_root)
> +
> +static inline enum qcomtee_object_type
> +typeof_qcomtee_object(struct qcomtee_object *object)
> +{
> +       if (object == NULL_QCOMTEE_OBJECT)
> +               return QCOMTEE_OBJECT_TYPE_NULL;
> +       return object->object_type;
> +}
> +
> +static inline const char *qcomtee_object_name(struct qcomtee_object *object)
> +{
> +       if (object == NULL_QCOMTEE_OBJECT)
> +               return "null";
> +
> +       if (!object->name)
> +               return "no-name";
> +       return object->name;
> +}
> +
> +/**
> + * qcomtee_object_user_init() - Initialize an object for the user.
> + * @object: object to initialize.
> + * @ot: type of object as &enum qcomtee_object_type.
> + * @ops: instance of callbacks.
> + * @fmt: name assigned to the object.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcomtee_object_user_init(struct qcomtee_object *object,
> +                            enum qcomtee_object_type ot,
> +                            struct qcomtee_object_operations *ops,
> +                            const char *fmt, ...);
> +
> +/* Object release is RCU protected. */
> +int qcomtee_object_get(struct qcomtee_object *object);
> +void qcomtee_object_put(struct qcomtee_object *object);
> +
> +#define qcomtee_arg_for_each(i, args) \
> +       for (i = 0; args[i].type != QCOMTEE_ARG_TYPE_INV; i++)
> +
> +/* Next argument of type @type after index @i. */
> +int qcomtee_next_arg_type(struct qcomtee_arg *u, int i,
> +                         enum qcomtee_arg_type type);
> +
> +/* Iterate over argument of given type. */
> +#define qcomtee_arg_for_each_type(i, args, at)              \
> +       for (i = 0, i = qcomtee_next_arg_type(args, i, at); \

i = qcomtee_next_arg_type(args, 0, at)

> +            args[i].type != QCOMTEE_ARG_TYPE_INV;          \
> +            i++, i = qcomtee_next_arg_type(args, i, at))

i = qcomtee_next_arg_type(args, i + 1, at)

Cheers,
Jens

> +
> +#define qcomtee_arg_for_each_input_buffer(i, args) \
> +       qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_IB)
> +#define qcomtee_arg_for_each_output_buffer(i, args) \
> +       qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_OB)
> +#define qcomtee_arg_for_each_input_object(i, args) \
> +       qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_IO)
> +#define qcomtee_arg_for_each_output_object(i, args) \
> +       qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_OO)
> +
> +#endif /* __QCOM_TEE_H */
> diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
> index 8642ce7e4772..0efb2835d6dc 100644
> --- a/include/uapi/linux/tee.h
> +++ b/include/uapi/linux/tee.h
> @@ -59,6 +59,7 @@
>  #define TEE_IMPL_ID_OPTEE      1
>  #define TEE_IMPL_ID_AMDTEE     2
>  #define TEE_IMPL_ID_TSTEE      3
> +#define TEE_IMPL_ID_QTEE       4
>
>  /*
>   * OP-TEE specific capabilities
>
> --
> 2.34.1
>
Re: [PATCH v3 08/11] tee: add Qualcomm TEE driver
Posted by Amirreza Zarrabi 8 months, 1 week ago
Hi Jens,

On 4/8/2025 10:47 PM, Jens Wiklander wrote:
> Hi Amirreza,
> 
> On Fri, Mar 28, 2025 at 3:48 AM Amirreza Zarrabi
> <amirreza.zarrabi@oss.qualcomm.com> wrote:
>>
>> Introduce qcomtee_object, which represents an object in both QTEE and
>> the kernel. QTEE clients can invoke an instance of qcomtee_object to
>> access QTEE services. If this invocation produces a new object in QTEE,
>> an instance of qcomtee_object will be returned.
>>
>> Similarly, QTEE can request services from the kernel by issuing a callback
>> request, which invokes an instance of qcomtee_object in the kernel.
>> Any subsystem that exposes a service to QTEE should allocate and initialize
>> an instance of qcomtee_object with a dispatcher callback that is called
>> when the object is invoked.
>>
>> Implement initial support for exporting qcomtee_object to userspace
>> and QTEE, enabling the invocation of objects hosted in QTEE and userspace
>> through the TEE subsystem.
>>
>> Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
>> ---
>>  drivers/tee/Kconfig                    |   1 +
>>  drivers/tee/Makefile                   |   1 +
>>  drivers/tee/qcomtee/Kconfig            |  10 +
>>  drivers/tee/qcomtee/Makefile           |   9 +
>>  drivers/tee/qcomtee/async.c            | 160 +++++++
>>  drivers/tee/qcomtee/call.c             | 753 +++++++++++++++++++++++++++++++
>>  drivers/tee/qcomtee/core.c             | 801 +++++++++++++++++++++++++++++++++
>>  drivers/tee/qcomtee/qcom_scm.c         |  38 ++
>>  drivers/tee/qcomtee/qcomtee_msg.h      | 239 ++++++++++
>>  drivers/tee/qcomtee/qcomtee_private.h  | 222 +++++++++
>>  drivers/tee/qcomtee/release.c          |  48 ++
>>  drivers/tee/qcomtee/shm.c              | 149 ++++++
>>  drivers/tee/qcomtee/user_obj.c         | 710 +++++++++++++++++++++++++++++
>>  include/linux/firmware/qcom/qcom_tee.h | 302 +++++++++++++
>>  include/uapi/linux/tee.h               |   1 +
>>  15 files changed, 3444 insertions(+)
>>
>> diff --git a/drivers/tee/Kconfig b/drivers/tee/Kconfig
>> index 61b507c18780..3a995d7f0d74 100644
>> --- a/drivers/tee/Kconfig
>> +++ b/drivers/tee/Kconfig
>> @@ -16,5 +16,6 @@ if TEE
>>  source "drivers/tee/optee/Kconfig"
>>  source "drivers/tee/amdtee/Kconfig"
>>  source "drivers/tee/tstee/Kconfig"
>> +source "drivers/tee/qcomtee/Kconfig"
>>
>>  endif
>> diff --git a/drivers/tee/Makefile b/drivers/tee/Makefile
>> index 5488cba30bd2..74e987f8f7ea 100644
>> --- a/drivers/tee/Makefile
>> +++ b/drivers/tee/Makefile
>> @@ -6,3 +6,4 @@ tee-objs += tee_shm_pool.o
>>  obj-$(CONFIG_OPTEE) += optee/
>>  obj-$(CONFIG_AMDTEE) += amdtee/
>>  obj-$(CONFIG_ARM_TSTEE) += tstee/
>> +obj-$(CONFIG_QCOMTEE) += qcomtee/
>> diff --git a/drivers/tee/qcomtee/Kconfig b/drivers/tee/qcomtee/Kconfig
>> new file mode 100644
>> index 000000000000..d180a6d07d33
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/Kconfig
>> @@ -0,0 +1,10 @@
>> +# SPDX-License-Identifier: GPL-2.0-only
>> +# Qualcomm Trusted Execution Environment Configuration
>> +config QCOMTEE
>> +       tristate "Qualcomm TEE Support"
>> +       select QCOM_SCM
>> +       help
>> +         This option enables the Qualcomm Trusted Execution Environment (QTEE)
>> +         driver. It provides an API to access services offered by QTEE and any
>> +         loaded Trusted Applications (TAs), as well as exporting kernel
>> +         services to QTEE.
>> diff --git a/drivers/tee/qcomtee/Makefile b/drivers/tee/qcomtee/Makefile
>> new file mode 100644
>> index 000000000000..1b14b943e5f5
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/Makefile
>> @@ -0,0 +1,9 @@
>> +# SPDX-License-Identifier: GPL-2.0-only
>> +obj-$(CONFIG_QCOMTEE) += qcomtee.o
>> +qcomtee-objs += async.o
>> +qcomtee-objs += call.o
>> +qcomtee-objs += core.o
>> +qcomtee-objs += qcom_scm.o
>> +qcomtee-objs += release.o
>> +qcomtee-objs += shm.o
>> +qcomtee-objs += user_obj.o
>> diff --git a/drivers/tee/qcomtee/async.c b/drivers/tee/qcomtee/async.c
>> new file mode 100644
>> index 000000000000..4c880c3441a2
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/async.c
>> @@ -0,0 +1,160 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#include "qcomtee_private.h"
>> +#include "qcomtee_msg.h"
>> +
>> +#define QCOMTEE_ASYNC_VERSION_1_0 0x00010000U /* Maj: 0x0001, Min: 0x0000. */
>> +#define QCOMTEE_ASYNC_VERSION_1_1 0x00010001U /* Maj: 0x0001, Min: 0x0001. */
>> +#define QCOMTEE_ASYNC_VERSION_1_2 0x00010002U /* Maj: 0x0001, Min: 0x0002. */
>> +#define QCOMTEE_ASYNC_VERSION QCOMTEE_ASYNC_VERSION_1_2 /* Current Version. */
>> +
>> +#define QCOMTEE_ASYNC_VERSION_MAJOR(n) upper_16_bits(n)
>> +#define QCOMTEE_ASYNC_VERSION_MINOR(n) lower_16_bits(n)
>> +
>> +/**
>> + * struct qcomtee_async_msg_hdr - Asynchronous message header format.
>> + * @version: current async protocol version of the remote endpoint.
>> + * @op: async operation.
>> + *
>> + * @version specifies the endpoint's (QTEE or driver) supported async protocol.
>> + * For example, if QTEE sets @version to %QCOMTEE_ASYNC_VERSION_1_1, QTEE
>> + * handles operations supported in %QCOMTEE_ASYNC_VERSION_1_1 or
>> + * %QCOMTEE_ASYNC_VERSION_1_0. @op determines the message format.
>> + */
>> +struct qcomtee_async_msg_hdr {
>> +       u32 version;
>> +       u32 op;
>> +};
>> +
>> +/* Size of an empty async message. */
>> +#define QCOMTEE_ASYNC_MSG_ZERO sizeof(struct qcomtee_async_msg_hdr)
>> +
>> +/**
>> + * struct qcomtee_async_release_msg - Release asynchronous message.
>> + * @hdr: message header as &struct qcomtee_async_msg_hdr.
>> + * @counts: number of objects in @object_ids.
>> + * @object_ids: array of object IDs that should be released.
>> + *
>> + * Available in Maj = 0x0001, Min >= 0x0000.
>> + */
>> +struct qcomtee_async_release_msg {
>> +       struct qcomtee_async_msg_hdr hdr;
>> +       u32 counts;
>> +       u32 object_ids[] __counted_by(counts);
>> +};
>> +
>> +/**
>> + * qcomtee_get_async_buffer() - Get the start of the asynchronous message.
>> + * @oic: context used for the current invocation.
>> + * @async_buffer: return buffer to extract from or fill in async messages.
>> + *
>> + * If @oic is used for direct object invocation, the whole outbound buffer
>> + * is available for the async message. If @oic is used for a callback request,
>> + * the tail of the outbound buffer (after the callback request message) is
>> + * available for the async message.
>> + *
>> + * The start of the async buffer is aligned, see qcomtee_msg_offset_align().
>> + */
>> +static void qcomtee_get_async_buffer(struct qcomtee_object_invoke_ctx *oic,
>> +                                    struct qcomtee_buffer *async_buffer)
>> +{
>> +       struct qcomtee_msg_callback *msg;
>> +       unsigned int offset;
>> +       int i;
>> +
>> +       if (!(oic->flags & QCOMTEE_OIC_FLAG_BUSY)) {
>> +               /* The outbound buffer is empty. Using the whole buffer. */
>> +               offset = 0;
>> +       } else {
>> +               msg = (struct qcomtee_msg_callback *)oic->out_msg.addr;
>> +
>> +               /* Start offset in a message for buffer arguments. */
>> +               offset = qcomtee_msg_buffer_args(struct qcomtee_msg_callback,
>> +                                                qcomtee_msg_args(msg));
>> +
>> +               /* Add size of IB arguments. */
>> +               qcomtee_msg_for_each_input_buffer(i, msg)
>> +                       offset += qcomtee_msg_offset_align(msg->args[i].b.size);
>> +
>> +               /* Add size of OB arguments. */
>> +               qcomtee_msg_for_each_output_buffer(i, msg)
>> +                       offset += qcomtee_msg_offset_align(msg->args[i].b.size);
>> +       }
>> +
>> +       async_buffer->addr = oic->out_msg.addr + offset;
>> +       async_buffer->size = oic->out_msg.size - offset;
>> +}
>> +
>> +/**
>> + * async_release() - Process QTEE async release requests.
>> + * @oic: context used for the current invocation.
>> + * @msg: async message for object release.
>> + * @size: size of the async buffer available.
>> + *
>> + * Return: Size of the outbound buffer used when processing @msg.
>> + */
>> +static size_t async_release(struct qcomtee_object_invoke_ctx *oic,
>> +                           struct qcomtee_async_msg_hdr *async_msg,
>> +                           size_t size)
>> +{
>> +       struct qcomtee_async_release_msg *msg;
>> +       struct qcomtee_object *object;
>> +       int i;
>> +
>> +       msg = (struct qcomtee_async_release_msg *)async_msg;
>> +
>> +       for (i = 0; i < msg->counts; i++) {
>> +               object = qcomtee_idx_erase(msg->object_ids[i]);
>> +               qcomtee_object_put(object);
>> +       }
>> +
>> +       return struct_size(msg, object_ids, msg->counts);
>> +}
>> +
>> +/**
>> + * qcomtee_fetch_async_reqs() - Fetch and process asynchronous messages.
>> + * @oic: context used for the current invocation.
>> + *
>> + * Calls handlers to process the requested operations in the async message.
>> + * Currently, only supports async release requests.
>> + */
>> +void qcomtee_fetch_async_reqs(struct qcomtee_object_invoke_ctx *oic)
>> +{
>> +       struct qcomtee_async_msg_hdr *async_msg;
>> +       struct qcomtee_buffer async_buffer;
>> +       size_t consumed, used = 0;
>> +
>> +       qcomtee_get_async_buffer(oic, &async_buffer);
>> +
>> +       while (async_buffer.size - used > QCOMTEE_ASYNC_MSG_ZERO) {
>> +               async_msg = (struct qcomtee_async_msg_hdr *)(async_buffer.addr +
>> +                                                            used);
>> +
>> +               if (QCOMTEE_ASYNC_VERSION_MAJOR(async_msg->version) !=
>> +                   QCOMTEE_ASYNC_VERSION_MAJOR(QCOMTEE_ASYNC_VERSION))
>> +                       goto out;
>> +
>> +               switch (async_msg->op) {
>> +               case QCOMTEE_MSG_OBJECT_OP_RELEASE:
>> +                       consumed = async_release(oic, async_msg,
>> +                                                async_buffer.size - used);
>> +                       break;
>> +               default:
>> +                       goto out;
>> +               }
>> +
>> +               /* Supported operation but unable to parse the message. */
>> +               if (!consumed)
>> +                       goto out;
>> +
>> +               /* Next async message. */
>> +               used += qcomtee_msg_offset_align(consumed);
>> +       }
>> +
>> +out:
>> +       /* Reset the async buffer so async requests do not loop to QTEE. */
>> +       memzero_explicit(async_buffer.addr, async_buffer.size);
>> +}
>> diff --git a/drivers/tee/qcomtee/call.c b/drivers/tee/qcomtee/call.c
>> new file mode 100644
>> index 000000000000..f7f5c2c0bebb
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/call.c
>> @@ -0,0 +1,753 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>> +
>> +#include <linux/slab.h>
>> +#include <linux/tee.h>
>> +#include <linux/platform_device.h>
>> +
>> +#include "qcomtee_private.h"
>> +
>> +static int find_qtee_object(struct qcomtee_object **object, unsigned long id,
>> +                           struct qcomtee_context_data *ctxdata)
>> +{
>> +       int err = 0;
>> +
>> +       guard(rcu)();
> 
> Does the qcomtee_object_get() call need to be RCU protected?
> 

Yes, qcomtee_object_get() should be RCU protected. This ensures safety in
case a userspace client releases a qtee object and tries to access it
concurrently.


>> +       /* Object release is RCU protected. */
>> +       *object = idr_find(&ctxdata->qtee_objects_idr, id);
>> +       if (!qcomtee_object_get(*object))
>> +               err = -EINVAL;
>> +
>> +       return err;
>> +}
>> +
>> +static void del_qtee_object(unsigned long id,
>> +                           struct qcomtee_context_data *ctxdata)
>> +{
>> +       struct qcomtee_object *object;
>> +
>> +       scoped_guard(spinlock, &ctxdata->qtee_lock)
>> +               object = idr_remove(&ctxdata->qtee_objects_idr, id);
>> +
>> +       qcomtee_object_put(object);
>> +}
>> +
>> +/**
>> + * qcomtee_context_add_qtee_object() - Add a QTEE object to the context.
>> + * @param: TEE parameter representing @object.
>> + * @object: QTEE object.
>> + * @ctx: context to add the object.
>> + *
>> + * It assumes @object is %QCOMTEE_OBJECT_TYPE_TEE and the caller has already
>> + * issued qcomtee_object_get() for @object.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_context_add_qtee_object(struct tee_param *param,
>> +                                   struct qcomtee_object *object,
>> +                                   struct tee_context *ctx)
>> +{
>> +       int ret;
>> +       struct qcomtee_context_data *ctxdata = ctx->data;
>> +
>> +       guard(spinlock)(&ctxdata->qtee_lock);
>> +       ret = idr_alloc(&ctxdata->qtee_objects_idr, object, 0, 0, GFP_KERNEL);
>> +       if (ret < 0)
>> +               return ret;
>> +
> 
> Is the spinlock needed when updating param below?

Not really, I'll move them out.
I'll probbaly need to use mutex considering using GFP_KERNEL in idr_alloc() ;).

> 
>> +       param->u.objref.id = ret;
>> +       /* QTEE Object: QCOMTEE_OBJREF_FLAG_TEE set. */
>> +       param->u.objref.flags = QCOMTEE_OBJREF_FLAG_TEE;
>> +
>> +       return 0;
>> +}
>> +
>> +/* Retrieve the QTEE object added with qcomtee_context_add_qtee_object(). */
>> +int qcomtee_context_find_qtee_object(struct qcomtee_object **object,
>> +                                    struct tee_param *param,
>> +                                    struct tee_context *ctx)
>> +{
>> +       struct qcomtee_context_data *ctxdata = ctx->data;
>> +
>> +       /* 'qtee_objects_idr' stores QTEE objects only. */
>> +       if (!(param->u.objref.flags & QCOMTEE_OBJREF_FLAG_TEE))
>> +               return -EINVAL;
>> +
>> +       return find_qtee_object(object, param->u.objref.id, ctxdata);
>> +}
>> +
>> +/**
>> + * qcomtee_context_del_qtee_object() - Delete a QTEE object from the context.
>> + * @param: TEE parameter representing @object.
>> + * @ctx: context for deleting the object.
>> + *
>> + * The @param has been initialized by qcomtee_context_add_qtee_object().
>> + */
>> +void qcomtee_context_del_qtee_object(struct tee_param *param,
>> +                                    struct tee_context *ctx)
>> +{
>> +       struct qcomtee_context_data *ctxdata = ctx->data;
>> +
>> +       /* 'qtee_objects_idr' stores QTEE objects only. */
>> +       if (param->u.objref.flags & QCOMTEE_OBJREF_FLAG_TEE)
>> +               del_qtee_object(param->u.objref.id, ctxdata);
>> +}
>> +
>> +/**
>> + * qcomtee_objref_to_arg() - Convert OBJREF parameter to QTEE argument.
>> + * @arg: QTEE argument.
>> + * @param: TEE parameter.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * It assumes @param is an OBJREF.
>> + * It does not set @arg.type; the caller should initialize it to a correct
>> + * &enum qcomtee_arg_type value. It gets the object's refcount in @arg;
>> + * the caller should manage to put it afterward.
>> + *
>> + * For objects that are not in QTEE (i.e. !(param->u.objref.flags &
>> + * QCOMTEE_OBJREF_FLAG_TEE)), it also calls qcomtee_object_get() to keep a
>> + * temporary copy for the driver as the release of them are asynchronous and
>> + * may go away even before returning from the invocation.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_objref_to_arg(struct qcomtee_arg *arg, struct tee_param *param,
>> +                         struct tee_context *ctx)
>> +{
>> +       struct qcomtee_object *object;
>> +       int err;
>> +
>> +       /* param is a NULL object: */
>> +       if (param->u.objref.id == TEE_OBJREF_NULL) {
>> +               arg->o = NULL_QCOMTEE_OBJECT;
>> +
>> +               return 0;
>> +       }
>> +
>> +       /* param is a callback object: */
>> +       if (param->u.objref.flags & QCOMTEE_OBJREF_FLAG_USER) {
>> +               err = qcomtee_user_param_to_object(&object, param, ctx);
> 
> How about a qcomtee_get_object_from_user_param() that already has
> increased the refcount? That should balance better with
> qcomtee_context_find_qtee_object().
> 

Ack.

>> +               if (!err)
>> +                       qcomtee_object_get(object);
>> +       /* param is a QTEE object: */
>> +       } else if (param->u.objref.flags & QCOMTEE_OBJREF_FLAG_TEE) {
>> +               err = qcomtee_context_find_qtee_object(&object, param, ctx);
>> +       } else {
>> +               err = -EINVAL;
>> +       }
>> +
>> +       arg->o = err ? NULL_QCOMTEE_OBJECT : object;
> 
> I prefer an if statement here instead of the ternary operator
> 

Ack.

>> +
>> +       return err;
>> +}
>> +
>> +/**
>> + * qcomtee_objref_from_arg() - Convert QTEE argument to OBJREF param.
>> + * @param: TEE parameter.
>> + * @arg: QTEE argument.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * It assumes @arg is of %QCOMTEE_ARG_TYPE_IO or %QCOMTEE_ARG_TYPE_OO.
>> + * It does not set @param.attr; the caller should initialize it to a
>> + * correct type.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_objref_from_arg(struct tee_param *param, struct qcomtee_arg *arg,
>> +                           struct tee_context *ctx)
>> +{
>> +       struct qcomtee_object *object;
>> +       int err;
>> +
>> +       /* param should be of OBJREF. */
>> +       if (param->attr != TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT &&
>> +           param->attr != TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT &&
>> +           param->attr != TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INOUT)
>> +               return -EINVAL;
>> +
>> +       object = arg->o;
>> +
>> +       switch (typeof_qcomtee_object(object)) {
>> +       case QCOMTEE_OBJECT_TYPE_NULL:
>> +               param->u.objref.id = TEE_OBJREF_NULL;
>> +               err = 0;
>> +
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_CB:
>> +               if (is_qcomtee_user_object(object))
>> +                       err = qcomtee_user_param_from_object(param, object,
>> +                                                            ctx);
>> +               else
>> +                       err = -EINVAL;
>> +
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_TEE:
>> +               err = qcomtee_context_add_qtee_object(param, object, ctx);
>> +
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_ROOT:
>> +       default:
>> +               return -EINVAL;
>> +       }
>> +
>> +       return err;
>> +}
>> +
>> +/**
>> + * qcomtee_params_to_args() - Convert TEE parameters to QTEE arguments.
>> + * @u: QTEE arguments.
>> + * @params: TEE parameters.
>> + * @num_params: number of elements in the parameter array.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * It assumes @u has at least @num_params + 1 entries and has been initialized
>> + * with %QCOMTEE_ARG_TYPE_INV as &struct qcomtee_arg.type.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +static int qcomtee_params_to_args(struct qcomtee_arg *u,
>> +                                 struct tee_param *params, int num_params,
>> +                                 struct tee_context *ctx)
>> +{
>> +       int i;
>> +
>> +       for (i = 0; i < num_params; i++) {
>> +               switch (params[i].attr) {
>> +               case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT:
>> +               case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
>> +                       u[i].flags = QCOMTEE_ARG_FLAGS_UADDR;
>> +                       u[i].b.uaddr = params[i].u.ubuf.uaddr;
>> +                       u[i].b.size = params[i].u.ubuf.size;
>> +
>> +                       if (params[i].attr ==
>> +                           TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT)
>> +                               u[i].type = QCOMTEE_ARG_TYPE_IB;
>> +                       else /* TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT */
>> +                               u[i].type = QCOMTEE_ARG_TYPE_OB;
>> +
>> +                       break;
>> +               case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT:
>> +                       u[i].type = QCOMTEE_ARG_TYPE_IO;
>> +                       if (qcomtee_objref_to_arg(&u[i], &params[i], ctx))
>> +                               goto out_failed;
>> +
>> +                       break;
>> +               case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT:
>> +                       u[i].type = QCOMTEE_ARG_TYPE_OO;
>> +                       u[i].o = NULL_QCOMTEE_OBJECT;
>> +                       break;
>> +               default:
>> +                       goto out_failed;
>> +               }
>> +       }
>> +
>> +       return 0;
>> +
>> +out_failed:
>> +       /* Undo qcomtee_objref_to_arg(). */
>> +       for (i--; i >= 0; i--) {
>> +               if (u[i].type != QCOMTEE_ARG_TYPE_IO)
>> +                       continue;
>> +
>> +               qcomtee_user_object_set_notify(u[i].o, false);
>> +               if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)
>> +                       qcomtee_object_put(u[i].o);
>> +
>> +               qcomtee_object_put(u[i].o);
>> +       }
>> +
>> +       return -EINVAL;
>> +}
>> +
>> +/**
>> + * qcomtee_params_from_args() - Convert QTEE arguments to TEE parameters.
>> + * @params: TEE parameters.
>> + * @u: QTEE arguments.
>> + * @num_params: number of elements in the parameter array.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * @u should have already been initialized by qcomtee_params_to_args().
>> + * This also represents the end of a QTEE invocation that started with
>> + * qcomtee_params_to_args() by releasing %QCOMTEE_ARG_TYPE_IO objects.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +static int qcomtee_params_from_args(struct tee_param *params,
>> +                                   struct qcomtee_arg *u, int num_params,
>> +                                   struct tee_context *ctx)
>> +{
>> +       int i, np;
>> +
>> +       qcomtee_arg_for_each(np, u) {
>> +               if (u[np].type == QCOMTEE_ARG_TYPE_OB) {
> 
> Can we use switch(u[np].type)?
> 

Ack.

>> +                       /* TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT */
>> +                       params[np].u.value.b = u[np].b.size;
> 
> Should this be params[np].u.ubuf.size?
> 

Ack.

>> +
>> +               } else if (u[np].type == QCOMTEE_ARG_TYPE_IO) {
>> +                       /* IEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT */
>> +                       qcomtee_object_put(u[np].o);
>> +
>> +               } else if (u[np].type == QCOMTEE_ARG_TYPE_OO) {
>> +                       /* TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT */
>> +                       if (qcomtee_objref_from_arg(&params[np], &u[np], ctx))
>> +                               goto out_failed;
>> +               }
>> +       }
>> +
>> +       return 0;
>> +
>> +out_failed:
>> +       /* Undo qcomtee_objref_from_arg(). */
>> +       for (i = 0; i < np; i++) {
>> +               if (params[i].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT)
>> +                       qcomtee_context_del_qtee_object(&params[i], ctx);
>> +       }
>> +
>> +       /* Release any IO and OO objects not processed. */
>> +       for (; u[i].type; i++) {
>> +               if (u[i].type == QCOMTEE_ARG_TYPE_OO ||
>> +                   u[i].type == QCOMTEE_ARG_TYPE_IO)
>> +                       qcomtee_object_put(u[i].o);
>> +       }
>> +
>> +       return -EINVAL;
>> +}
>> +
>> +/* TEE Device Ops. */
>> +
>> +static int qcomtee_params_check(struct tee_param *params, int num_params)
>> +{
>> +       int io = 0, oo = 0, ib = 0, ob = 0;
>> +       int i;
>> +
>> +       /* QTEE accepts 64 arguments. */
>> +       if (num_params > QCOMTEE_ARGS_MAX)
>> +               return -EINVAL;
>> +
>> +       /* Supported parameter types. */
>> +       for (i = 0; i < num_params; i++) {
>> +               switch (params[i].attr) {
>> +               case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT:
>> +                       ib++;
>> +                       break;
>> +               case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
>> +                       ob++;
>> +                       break;
>> +               case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT:
>> +                       io++;
>> +                       break;
>> +               case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT:
>> +                       oo++;
>> +                       break;
>> +               default:
>> +                       return -EINVAL;
>> +               }
>> +       }
>> +
>> +       /*  QTEE accepts 16 arguments of each supported types. */
>> +       if (io > QCOMTEE_ARGS_PER_TYPE || oo > QCOMTEE_ARGS_PER_TYPE ||
>> +           ib > QCOMTEE_ARGS_PER_TYPE || ob > QCOMTEE_ARGS_PER_TYPE)
>> +               return -EINVAL;
>> +
>> +       return 0;
>> +}
>> +
>> +/* Check if an operation on ROOT_QCOMTEE_OBJECT from userspace is permitted. */
>> +static int qcomtee_root_object_check(u32 op, struct tee_param *params,
>> +                                    int num_params)
>> +{
>> +       /* Some privileged operations recognized by QTEE. */
>> +       if (op == QCOMTEE_ROOT_OP_NOTIFY_DOMAIN_CHANGE ||
>> +           op == QCOMTEE_ROOT_OP_ADCI_ACCEPT ||
>> +           op == QCOMTEE_ROOT_OP_ADCI_SHUTDOWN)
>> +               return -EINVAL;
>> +
>> +       /*
>> +        * QCOMTEE_ROOT_OP_REGISTER_WITH_CREDENTIALS is to register with QTEE
>> +        * by passing a credential object as input OBJREF. TEE_OBJREF_NULL as a
>> +        * credential object represents a privileged client for QTEE and
>> +        * is used by the kernel only.
>> +        */
>> +       if (op == QCOMTEE_ROOT_OP_REGISTER_WITH_CREDENTIALS &&
>> +           num_params == 2) {
>> +               if (params[0].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT &&
>> +                   params[1].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT) {
>> +                       if (params[0].u.objref.id == TEE_OBJREF_NULL)
>> +                               return -EINVAL;
>> +               }
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +/**
>> + * qcomtee_object_invoke() - Invoke a QTEE object.
>> + * @ctx: TEE context.
>> + * @arg: ioctl arguments.
>> + * @params: parameters for the object.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +static int qcomtee_object_invoke(struct tee_context *ctx,
>> +                                struct tee_ioctl_object_invoke_arg *arg,
>> +                                struct tee_param *params)
>> +{
>> +       struct qcomtee_object_invoke_ctx *oic __free(kfree) = NULL;
>> +       struct qcomtee_context_data *ctxdata = ctx->data;
>> +       struct qcomtee_arg *u __free(kfree) = NULL;
>> +       struct qcomtee_object *object;
>> +       int i, ret, result;
>> +
>> +       if (qcomtee_params_check(params, arg->num_params))
>> +               return -EINVAL;
>> +
>> +       /* First, handle reserved operations: */
>> +       if (arg->op == QCOMTEE_MSG_OBJECT_OP_RELEASE) {
>> +               del_qtee_object(arg->object, ctxdata);
>> +
>> +               return 0;
>> +       }
>> +
>> +       /* Otherwise, invoke a QTEE object: */
>> +       oic = qcomtee_object_invoke_ctx_alloc(ctx);
>> +       if (!oic)
>> +               return -ENOMEM;
>> +
>> +       /* +1 for ending QCOMTEE_ARG_TYPE_INV. */
>> +       u = kcalloc(arg->num_params + 1, sizeof(*u), GFP_KERNEL);
>> +       if (!u)
>> +               return -ENOMEM;
>> +
>> +       /* Get an object to invoke. */
>> +       if (arg->object == TEE_OBJREF_NULL) {
>> +               /* Use ROOT if TEE_OBJREF_NULL is invoked. */
>> +               if (qcomtee_root_object_check(arg->op, params, arg->num_params))
>> +                       return -EINVAL;
>> +
>> +               object = ROOT_QCOMTEE_OBJECT;
>> +       } else if (find_qtee_object(&object, arg->object, ctxdata)) {
>> +               return -EINVAL;
>> +       }
>> +
>> +       ret = qcomtee_params_to_args(u, params, arg->num_params, ctx);
>> +       if (ret)
>> +               goto out;
>> +
>> +       ret = qcomtee_object_do_invoke(oic, object, arg->op, u, &result);
>> +       if (ret) {
>> +               qcomtee_arg_for_each_input_object(i, u) {
>> +                       qcomtee_user_object_set_notify(u[i].o, false);
>> +                       qcomtee_object_put(u[i].o);
>> +               }
>> +
>> +               goto out;
>> +       }
>> +
>> +       if (!result) {
>> +               /* Assume service is UNAVAIL if unable to process the result. */
>> +               if (qcomtee_params_from_args(params, u, arg->num_params, ctx))
>> +                       result = QCOMTEE_MSG_ERROR_UNAVAIL;
>> +       } else {
>> +               /*
>> +                * qcomtee_params_to_args() gets a copy of IO for the driver to
>> +                * make sure they do not get released while in the middle of
>> +                * invocation. On success (!result), qcomtee_params_from_args()
>> +                * puts them.
>> +                */
>> +               qcomtee_arg_for_each_input_object(i, u)
>> +                       qcomtee_object_put(u[i].o);
>> +       }
>> +
>> +       arg->ret = result;
>> +out:
>> +       qcomtee_object_put(object);
>> +
>> +       return ret;
>> +}
>> +
>> +/**
>> + * qcomtee_supp_recv() - Wait for a request for the supplicant.
>> + * @ctx: TEE context.
>> + * @op: requested operation on the object.
>> + * @num_params: number of elements in the parameter array.
>> + * @params: parameters for @op.
>> + *
>> + * The first parameter is a meta %TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT.
>> + * On input, it provides a user buffer. This buffer is used for parameters of
>> + * type %TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT in qcomtee_cb_params_from_args().
>> + * On output, the object ID and request ID are stored in the meta parameter.
>> + *
>> + * @num_params is updated to the number of parameters that actually exist
>> + * in @params on return.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +static int qcomtee_supp_recv(struct tee_context *ctx, u32 *op, u32 *num_params,
>> +                            struct tee_param *params)
>> +{
>> +       struct qcomtee_user_object_request_data data;
>> +       void __user *uaddr;
>> +       size_t ubuf_size;
>> +       int i, ret;
>> +
>> +       if (!*num_params)
>> +               return -EINVAL;
>> +
>> +       /* We expect the first parameter to be an INOUT + meta parameter. */
>> +       if (params->attr !=
>> +           (TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT | TEE_IOCTL_PARAM_ATTR_META))
> 
> Why aren't you using TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_*?

The mete parameter serves as both INPUT and OUTPUT. While the INPUT is similar
to a UBUF, the OUTPUT is neither UBUF nor OBJREF. Instead, the OUTPUT consists
of an Object ID and a request ID, which do not conform to the OBJREF format.
Therefore, I used the VALUE type to accommodate both.

> 
>> +               return -EINVAL;
>> +
>> +       /* Other parameters are none. */
>> +       for (i = 1; i < *num_params; i++)
>> +               if (params[i].attr)
>> +                       return -EINVAL;
>> +
>> +       if (!IS_ALIGNED(params->u.value.a, 8))
>> +               return -EINVAL;
>> +
>> +       /* User buffer and size from meta parameter. */
>> +       uaddr = u64_to_user_ptr(params->u.value.a);
>> +       ubuf_size = params->u.value.b;
> 
> Please use params->u.ubuf.uaddr and params->u.ubuf.size instead
> 
>> +       /* Process TEE parameters. +/-1 to ignore the meta parameter. */
>> +       ret = qcomtee_user_object_select(ctx, params + 1, *num_params - 1,
>> +                                        uaddr, ubuf_size, &data);
>> +       if (ret)
>> +               return ret;
>> +
>> +       params->u.value.a = data.object_id;
>> +       params->u.value.b = data.id;
> 
>  params->u.objref.{id, flags}?
> Should params->attr be updated with TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_*?
> 
>> +       params->u.value.c = 0;
>> +       *op = data.op;
>> +       *num_params = data.np + 1;
>> +
>> +       return 0;
>> +}
>> +
>> +/**
>> + * qcomtee_supp_send() - Submit a response for a request.
>> + * @ctx: TEE context.
>> + * @errno: return value for the request.
>> + * @num_params: number of elements in the parameter array.
>> + * @params: returned parameters.
>> + *
>> + * The first parameter is a meta %TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT.
>> + * It specifies the request ID this response belongs to.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +static int qcomtee_supp_send(struct tee_context *ctx, u32 errno, u32 num_params,
>> +                            struct tee_param *params)
>> +{
>> +       if (!num_params)
>> +               return -EINVAL;
>> +
>> +       /* We expect the first parameter to be an OUTPUT + meta parameter. */
>> +       if (params->attr != (TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT |
>> +                            TEE_IOCTL_PARAM_ATTR_META))
>> +               return -EINVAL;
> 
> Why is this used if it's to be ignored, making room for forward compatibility?
> 

Well, it has been used below "params->u.value.a". However, I can use a local
variable to emphasize that.

>> +
>> +       /* Process TEE parameters. +/-1 to ignore the meta parameter. */
>> +       return qcomtee_user_object_submit(ctx, params + 1, num_params - 1,
>> +                                         params->u.value.a, errno);
>> +}
>> +
>> +static int qcomtee_open(struct tee_context *ctx)
>> +{
>> +       struct qcomtee_context_data *ctxdata __free(kfree) = NULL;
>> +
>> +       ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
>> +       if (!ctxdata)
>> +               return -ENOMEM;
>> +
>> +       /*
>> +        * In the QTEE driver, the same context is used to refcount resources
>> +        * shared by QTEE. For example, teedev_ctx_get() is called for any
>> +        * instance of callback objects (see qcomtee_user_param_to_object()).
>> +        *
>> +        * Maintain a copy of teedev for QTEE as it serves as a direct user of
>> +        * this context. The teedev will be released in the context's release().
>> +        *
>> +        * tee_device_unregister() will remain blocked until all contexts
>> +        * are released. This includes contexts owned by the user, which are
>> +        * closed by teedev_close_context(), as well as those owned by QTEE
>> +        * closed by tee_context_put() in object's release().
>> +        */
>> +       if (!tee_device_get(ctx->teedev))
>> +               return -EINVAL;
>> +
>> +       idr_init(&ctxdata->qtee_objects_idr);
>> +       spin_lock_init(&ctxdata->qtee_lock);
>> +       idr_init(&ctxdata->reqs_idr);
>> +       INIT_LIST_HEAD(&ctxdata->reqs_list);
>> +       mutex_init(&ctxdata->reqs_lock);
>> +       init_completion(&ctxdata->req_c);
>> +
>> +       ctx->data = no_free_ptr(ctxdata);
>> +
>> +       return 0;
>> +}
>> +
>> +/* This is called when the user closes the device. */
>> +static void qcomtee_close_context(struct tee_context *ctx)
>> +{
>> +       struct qcomtee_context_data *ctxdata = ctx->data;
>> +       struct qcomtee_object *object;
>> +       int id;
>> +
>> +       /* Process QUEUED or PROCESSING requests. */
>> +       qcomtee_requests_destroy(ctxdata);
>> +       /* Release QTEE objects. */
>> +       idr_for_each_entry(&ctxdata->qtee_objects_idr, object, id)
>> +               qcomtee_object_put(object);
>> +}
>> +
>> +/* This is called when the final reference to the context goes away. */
>> +static void qcomtee_release(struct tee_context *ctx)
>> +{
>> +       struct qcomtee_context_data *ctxdata = ctx->data;
>> +
>> +       idr_destroy(&ctxdata->qtee_objects_idr);
>> +       idr_destroy(&ctxdata->reqs_idr);
>> +       kfree(ctxdata);
>> +
>> +       /* There is nothing shared in this context with QTEE. */
>> +       tee_device_put(ctx->teedev);
>> +}
>> +
>> +static void qcomtee_get_version(struct tee_device *teedev,
>> +                               struct tee_ioctl_version_data *vers)
>> +{
>> +       struct tee_ioctl_version_data v = {
>> +               .impl_id = TEE_IMPL_ID_QTEE,
>> +               .gen_caps = TEE_GEN_CAP_OBJREF,
>> +       };
>> +
>> +       *vers = v;
>> +}
>> +
>> +static const struct tee_driver_ops qcomtee_ops = {
>> +       .get_version = qcomtee_get_version,
>> +       .open = qcomtee_open,
>> +       .close_context = qcomtee_close_context,
>> +       .release = qcomtee_release,
>> +       .object_invoke_func = qcomtee_object_invoke,
>> +       .supp_recv = qcomtee_supp_recv,
>> +       .supp_send = qcomtee_supp_send,
>> +};
>> +
>> +static const struct tee_desc qcomtee_desc = {
>> +       .name = "qcomtee",
>> +       .ops = &qcomtee_ops,
>> +       .owner = THIS_MODULE,
>> +};
>> +
>> +static int qcomtee_probe(struct platform_device *pdev)
>> +{
>> +       struct workqueue_struct *async_wq;
>> +       struct tee_device *teedev;
>> +       struct tee_shm_pool *pool;
>> +       struct tee_context *ctx;
>> +       struct qcomtee *qcomtee;
>> +       int err;
>> +
>> +       qcomtee = kzalloc(sizeof(*qcomtee), GFP_KERNEL);
>> +       if (!qcomtee)
>> +               return -ENOMEM;
>> +
>> +       pool = qcomtee_shm_pool_alloc();
>> +       if (IS_ERR(pool)) {
>> +               err = PTR_ERR(pool);
>> +
>> +               goto err_free_qcomtee;
>> +       }
>> +
>> +       teedev = tee_device_alloc(&qcomtee_desc, NULL, pool, qcomtee);
>> +       if (IS_ERR(teedev)) {
>> +               err = PTR_ERR(teedev);
>> +
>> +               goto err_pool_destroy;
>> +       }
>> +
>> +       qcomtee->teedev = teedev;
>> +       qcomtee->pool = pool;
>> +       err = tee_device_register(qcomtee->teedev);
>> +       if (err)
>> +               goto err_unreg_teedev;
>> +
>> +       platform_set_drvdata(pdev, qcomtee);
>> +       /* Start async wq. */
>> +       async_wq = alloc_ordered_workqueue("qcomtee_wq", 0);
>> +       if (!async_wq)
>> +               goto err_unreg_teedev;
>> +
>> +       qcomtee->wq = async_wq;
>> +       /* Driver context used for async operations of teedev. */
>> +       ctx = teedev_open(qcomtee->teedev);
>> +       if (IS_ERR(ctx)) {
>> +               err = PTR_ERR(ctx);
>> +
>> +               goto err_dest_wq;
>> +       }
>> +
>> +       qcomtee->ctx = ctx;
>> +
>> +       return 0;
>> +
>> +err_dest_wq:
>> +       destroy_workqueue(qcomtee->wq);
>> +err_unreg_teedev:
>> +       tee_device_unregister(qcomtee->teedev);
>> +err_pool_destroy:
>> +       tee_shm_pool_free(pool);
>> +err_free_qcomtee:
>> +       kfree(qcomtee);
>> +
>> +       return err;
>> +}
>> +
>> +/**
>> + * qcomtee_remove() - Device Removal Routine.
>> + * @pdev: platform device information struct.
>> + *
>> + * It is called by the platform subsystem to alert the driver that it should
>> + * release the device.
>> + *
>> + * QTEE does not provide an API to inform it about a callback object going away.
>> + * However, when releasing QTEE objects, any callback object sent to QTEE
>> + * previously would be released by QTEE as part of the object release.
>> + */
>> +static void qcomtee_remove(struct platform_device *pdev)
>> +{
>> +       struct qcomtee *qcomtee = platform_get_drvdata(pdev);
>> +
>> +       teedev_close_context(qcomtee->ctx);
>> +       /* Wait for RELEASE operations to be processed for QTEE objects. */
>> +       tee_device_unregister(qcomtee->teedev);
>> +       destroy_workqueue(qcomtee->wq);
>> +       tee_shm_pool_free(qcomtee->pool);
>> +       kfree(qcomtee);
>> +}
>> +
>> +static const struct platform_device_id qcomtee_ids[] = { { "qcomtee", 0 }, {} };
>> +MODULE_DEVICE_TABLE(platform, qcomtee_ids);
>> +
>> +static struct platform_driver qcomtee_platform_driver = {
>> +       .probe = qcomtee_probe,
>> +       .remove = qcomtee_remove,
>> +       .driver = {
>> +               .name = "qcomtee",
>> +       },
>> +       .id_table = qcomtee_ids,
>> +};
>> +
>> +module_platform_driver(qcomtee_platform_driver);
>> +
>> +MODULE_AUTHOR("Qualcomm");
>> +MODULE_DESCRIPTION("QTEE driver");
>> +MODULE_VERSION("1.0");
>> +MODULE_LICENSE("GPL");
>> diff --git a/drivers/tee/qcomtee/core.c b/drivers/tee/qcomtee/core.c
>> new file mode 100644
>> index 000000000000..162e32db656a
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/core.c
>> @@ -0,0 +1,801 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>> +
>> +#include <linux/init.h>
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/xarray.h>
>> +
>> +#include "qcomtee_msg.h"
>> +#include "qcomtee_private.h"
>> +
>> +/* This is the QTEE root object. */
>> +struct qcomtee_object qcomtee_object_root = {
>> +       .name = "root",
>> +       .object_type = QCOMTEE_OBJECT_TYPE_ROOT,
>> +       .info.qtee_id = QCOMTEE_MSG_OBJECT_ROOT,
>> +};
>> +EXPORT_SYMBOL_GPL(qcomtee_object_root);
>> +
>> +/* Next argument of type @type after index @i. */
>> +int qcomtee_next_arg_type(struct qcomtee_arg *u, int i,
>> +                         enum qcomtee_arg_type type)
>> +{
>> +       while (u[i].type != QCOMTEE_ARG_TYPE_INV && u[i].type != type)
>> +               i++;
>> +       return i;
>> +}
>> +
>> +/*
>> + * QTEE expects IDs with the QCOMTEE_MSG_OBJECT_NS_BIT set for objects
>> + * of the QCOMTEE_OBJECT_TYPE_CB type.
>> + */
>> +#define QCOMTEE_OBJECT_ID_START (QCOMTEE_MSG_OBJECT_NS_BIT + 1)
>> +#define QCOMTEE_OBJECT_ID_END (UINT_MAX)
> 
> Should this be U32_MAX considering that QCOMTEE_MSG_OBJECT_NS_BIT is
> defined as BIT(31)?
> 

You are right.

>> +
>> +#define QCOMTEE_OBJECT_SET(p, type, ...) \
>> +       __QCOMTEE_OBJECT_SET(p, type, ##__VA_ARGS__, 0UL)
>> +#define __QCOMTEE_OBJECT_SET(p, type, optr, ...)           \
>> +       do {                                               \
>> +               (p)->object_type = (type);                 \
>> +               (p)->info.qtee_id = (unsigned long)(optr); \
>> +       } while (0)
>> +
>> +static struct qcomtee_object *
>> +qcomtee_qtee_object_alloc(struct qcomtee_object_invoke_ctx *oic,
>> +                         unsigned int object_id)
>> +{
>> +       struct qcomtee *qcomtee = tee_get_drvdata(oic->ctx->teedev);
>> +       struct qcomtee_object *object __free(kfree);
>> +
>> +       object = kzalloc(sizeof(*object), GFP_KERNEL);
>> +       if (!object)
>> +               return NULL_QCOMTEE_OBJECT;
>> +
>> +       /* If failed, "no-name". */
>> +       object->name = kasprintf(GFP_KERNEL, "qcomtee-%u", object_id);
> 
> Where does it become "no-name" if object->name is NULL? Is it worth it
> with a special case for the unlikely condition that kasprintf() fails
> while no other memory allocations fail?
> 

Yes, it is a "no-name" if NULL. Since failure is unlikely, I do not check the
return value. If someone wants to retrieve the name, qcomtee_object_name()
will return "no-name." The only special handling occurs within qcomtee_object_name().

>> +       QCOMTEE_OBJECT_SET(object, QCOMTEE_OBJECT_TYPE_TEE, object_id);
>> +       kref_init(&object->refcount);
>> +       /* A QTEE object requires a context for async operations. */
>> +       object->info.qcomtee_async_ctx = qcomtee->ctx;
>> +       teedev_ctx_get(object->info.qcomtee_async_ctx);
>> +
>> +       return no_free_ptr(object);
>> +}
>> +
>> +void qcomtee_qtee_object_free(struct qcomtee_object *object)
>> +{
>> +       /* See qcomtee_qtee_object_alloc(). */
>> +       teedev_ctx_put(object->info.qcomtee_async_ctx);
>> +
>> +       kfree(object->name);
>> +       kfree(object);
>> +}
>> +
>> +static void qcomtee_object_release(struct kref *refcount)
>> +{
>> +       struct qcomtee_object *object;
>> +       const char *name;
>> +
>> +       object = container_of(refcount, struct qcomtee_object, refcount);
>> +
>> +       synchronize_rcu();
> 
> Please add a comment in the code explaining why this is needed.
> 

Ack.

>> +
>> +       switch (typeof_qcomtee_object(object)) {
>> +       case QCOMTEE_OBJECT_TYPE_TEE:
>> +               qcomtee_release_tee_object(object);
>> +
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_CB:
>> +               name = object->name;
>> +
>> +               if (object->ops->release)
>> +                       object->ops->release(object);
>> +
>> +               kfree_const(name);
>> +
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_ROOT:
>> +       case QCOMTEE_OBJECT_TYPE_NULL:
>> +       default:
>> +               break;
>> +       }
>> +}
>> +
>> +/**
>> + * qcomtee_object_get() - Increase the object's reference count.
>> + * @object: object to increase the reference count.
>> + */
>> +int qcomtee_object_get(struct qcomtee_object *object)
>> +{
>> +       if (object != NULL_QCOMTEE_OBJECT && object != ROOT_QCOMTEE_OBJECT)
>> +               return kref_get_unless_zero(&object->refcount);
>> +
>> +       return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(qcomtee_object_get);
>> +
>> +/**
>> + * qcomtee_object_put() - Decrease the object's reference count.
>> + * @object: object to decrease the reference count.
>> + */
>> +void qcomtee_object_put(struct qcomtee_object *object)
>> +{
>> +       if (object != NULL_QCOMTEE_OBJECT && object != ROOT_QCOMTEE_OBJECT)
>> +               kref_put(&object->refcount, qcomtee_object_release);
>> +}
>> +EXPORT_SYMBOL_GPL(qcomtee_object_put);
>> +
>> +/*
>> + * ''Local Object Table''.
>> + * Objects from the kernel exported to QTEE are assigned an ID and stored
>> + * in xa_qcom_local_objects (also known as the kernel object table).
>> + * QTEE uses this ID to reference the objects using qcomtee_local_object_get().
>> + */
>> +static DEFINE_XARRAY_ALLOC(xa_qcom_local_objects);
> 
> Please move this to the top of this file where the other global
> variables are kept. Do we have/need any checks to see the unrelated
> processes doesn't use objects from each other because they manage to
> guess an id?
> 

I'll move it to the top of the file.

This table contains objects that are exported to the QTEE, allowing it
to invoke them to request a service.

QTEE has the capability to invoke all of these objects. The only
validation we perform is to ensure that, if QTEE decides to return any
objects in this table to a client (e.g., as OBJREF_OUTPUT on return),
the client actually receives an object it owns. For reference, see
qcomtee_user_param_from_object() in user_obj.c or
qcomtee_memobj_param_from_object() in mem_obj.c

>> +
>> +static int qcomtee_idx_alloc(u32 *idx, struct qcomtee_object *object)
>> +{
>> +       static u32 xa_last_id = QCOMTEE_OBJECT_ID_START;
>> +
>> +       /* Every ID allocated here has QCOMTEE_MSG_OBJECT_NS_BIT set. */
>> +       return xa_alloc_cyclic(&xa_qcom_local_objects, idx, object,
>> +                              XA_LIMIT(QCOMTEE_OBJECT_ID_START,
>> +                                       QCOMTEE_OBJECT_ID_END),
>> +                              &xa_last_id, GFP_KERNEL);
>> +}
>> +
>> +struct qcomtee_object *qcomtee_idx_erase(u32 idx)
>> +{
>> +       if (idx < QCOMTEE_OBJECT_ID_START || idx > QCOMTEE_OBJECT_ID_END)
>> +               return NULL_QCOMTEE_OBJECT;
>> +
>> +       return xa_erase(&xa_qcom_local_objects, idx);
>> +}
>> +
>> +/**
>> + * qcomtee_object_id_get() - Get an ID for an object to send to QTEE.
>> + * @object: object to assign an ID.
>> + * @object_id: object ID.
>> + *
>> + * This is called on the path to QTEE to construct the message; see
>> + * qcomtee_prepare_msg() and qcomtee_update_msg().
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +static int qcomtee_object_id_get(struct qcomtee_object *object,
>> +                                unsigned int *object_id)
>> +{
>> +       u32 idx;
>> +
>> +       switch (typeof_qcomtee_object(object)) {
>> +       case QCOMTEE_OBJECT_TYPE_CB:
>> +               if (qcomtee_idx_alloc(&idx, object) < 0)
>> +                       return -ENOSPC;
>> +
>> +               *object_id = idx;
>> +
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_ROOT:
>> +       case QCOMTEE_OBJECT_TYPE_TEE:
>> +               *object_id = object->info.qtee_id;
>> +
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_NULL:
>> +               *object_id = QCOMTEE_MSG_OBJECT_NULL;
>> +
>> +               break;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +/* Release object ID assigned in qcomtee_object_id_get. */
>> +static void qcomtee_object_id_put(unsigned int object_id)
>> +{
>> +       qcomtee_idx_erase(object_id);
>> +}
>> +
>> +/**
>> + * qcomtee_local_object_get() - Get the object referenced by the ID.
>> + * @object_id: object ID.
>> + *
>> + * It is called on the path from QTEE.
>> + * It is called on behalf of QTEE to obtain an instance of an object
>> + * for a given ID. It increases the object's reference count on success.
>> + *
>> + * Return: On error, returns %NULL_QCOMTEE_OBJECT.
>> + *         On success, returns the object.
>> + */
>> +static struct qcomtee_object *qcomtee_local_object_get(unsigned int object_id)
>> +{
>> +       struct qcomtee_object *object;
>> +
>> +       /*
>> +        * This is not protected by an RCU read lock because we are
>> +        * confident that QTEE does not issue a RELEASE request and
>> +        * qcomtee_local_object_get() concurrently.
>> +        */
> 
> I think it would be better to not depend on that. An RCU read lock
> must be very cheap compared to what we do in this context.
> 

Ack.

>> +       object = xa_load(&xa_qcom_local_objects, object_id);
>> +
>> +       qcomtee_object_get(object);
>> +
>> +       return object;
>> +}
>> +
>> +/**
>> + * qcomtee_object_user_init() - Initialize an object for the user.
>> + * @object: object to initialize.
>> + * @ot: type of object as &enum qcomtee_object_type.
>> + * @ops: instance of callbacks.
>> + * @fmt: name assigned to the object.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_object_user_init(struct qcomtee_object *object,
>> +                            enum qcomtee_object_type ot,
>> +                            struct qcomtee_object_operations *ops,
>> +                            const char *fmt, ...)
>> +{
>> +       va_list ap;
>> +       int ret;
>> +
>> +       kref_init(&object->refcount);
>> +       QCOMTEE_OBJECT_SET(object, QCOMTEE_OBJECT_TYPE_NULL);
>> +
>> +       va_start(ap, fmt);
>> +       switch (ot) {
>> +       case QCOMTEE_OBJECT_TYPE_NULL:
>> +               ret = 0;
>> +
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_CB:
>> +               object->ops = ops;
>> +               if (!object->ops->dispatch)
>> +                       return -EINVAL;
>> +
>> +               /* If failed, "no-name". */
>> +               object->name = kvasprintf_const(GFP_KERNEL, fmt, ap);
>> +               QCOMTEE_OBJECT_SET(object, QCOMTEE_OBJECT_TYPE_CB);
>> +
>> +               ret = 0;
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_ROOT:
>> +       case QCOMTEE_OBJECT_TYPE_TEE:
>> +       default:
>> +               ret = -EINVAL;
>> +       }
>> +       va_end(ap);
>> +
>> +       return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(qcomtee_object_user_init);
>> +
>> +/**
>> + * qcomtee_object_type() - Returns the type of object represented by an ID.
>> + * @object_id: object ID for the object.
>> + *
>> + * This is similar to typeof_qcomtee_object(), but instead of receiving an
>> + * object as an argument, it receives an object ID. It is used internally
>> + * on the return path from QTEE.
>> + *
>> + * Return: Returns the type of object referenced by @object_id.
>> + */
>> +static enum qcomtee_object_type qcomtee_object_type(unsigned int object_id)
>> +{
>> +       if (object_id == QCOMTEE_MSG_OBJECT_NULL)
>> +               return QCOMTEE_OBJECT_TYPE_NULL;
>> +
>> +       if (object_id & QCOMTEE_MSG_OBJECT_NS_BIT)
>> +               return QCOMTEE_OBJECT_TYPE_CB;
>> +
>> +       return QCOMTEE_OBJECT_TYPE_TEE;
>> +}
>> +
>> +/**
>> + * qcomtee_object_qtee_init() - Initialize an object for QTEE.
>> + * @object: object returned.
>> + * @object_id: object ID received from QTEE.
>> + *
>> + * Return: On failure, returns < 0 and sets @object to %NULL_QCOMTEE_OBJECT.
>> + *         On success, returns 0
>> + */
>> +static int qcomtee_object_qtee_init(struct qcomtee_object_invoke_ctx *oic,
>> +                                   struct qcomtee_object **object,
>> +                                   unsigned int object_id)
>> +{
>> +       int ret = 0;
>> +
>> +       switch (qcomtee_object_type(object_id)) {
>> +       case QCOMTEE_OBJECT_TYPE_NULL:
>> +               *object = NULL_QCOMTEE_OBJECT;
>> +
>> +               break;
>> +       case QCOMTEE_OBJECT_TYPE_CB:
>> +               *object = qcomtee_local_object_get(object_id);
>> +               if (*object == NULL_QCOMTEE_OBJECT)
>> +                       ret = -EINVAL;
>> +
>> +               break;
>> +
>> +       default: /* QCOMTEE_OBJECT_TYPE_TEE */
>> +               *object = qcomtee_qtee_object_alloc(oic, object_id);
>> +               if (*object == NULL_QCOMTEE_OBJECT)
>> +                       ret = -ENOMEM;
>> +
>> +               break;
>> +       }
>> +
>> +       return ret;
>> +}
>> +
>> +/*
>> + * ''Marshaling API''
>> + * qcomtee_prepare_msg  - Prepare the inbound buffer for sending to QTEE
>> + * qcomtee_update_args  - Parse the QTEE response in the inbound buffer
>> + * qcomtee_prepare_args - Parse the QTEE request from the outbound buffer
>> + * qcomtee_update_msg   - Update the outbound buffer with the response for QTEE
>> + */
>> +
>> +static int qcomtee_prepare_msg(struct qcomtee_object_invoke_ctx *oic,
>> +                              struct qcomtee_object *object, u32 op,
>> +                              struct qcomtee_arg *u)
>> +{
>> +       struct qcomtee_msg_object_invoke *msg;
>> +       unsigned int object_id;
>> +       int i, ib, ob, io, oo;
>> +       size_t off;
>> +
>> +       /* Use the input message buffer in 'oic'. */
>> +       msg = oic->in_msg.addr;
>> +
>> +       /* Start offset in a message for buffer arguments. */
>> +       off = qcomtee_msg_buffer_args(struct qcomtee_msg_object_invoke,
>> +                                     qcomtee_args_len(u));
>> +
>> +       /* Get the ID of the object being invoked. */
>> +       if (qcomtee_object_id_get(object, &object_id))
>> +               return -ENOSPC;
>> +
>> +       ib = 0;
>> +       qcomtee_arg_for_each_input_buffer(i, u) {
>> +               void *ptr;
>> +
>> +               /* Overflow already checked in qcomtee_msg_buffers_alloc(). */
>> +               msg->args[ib].b.offset = off;
>> +               msg->args[ib].b.size = u[i].b.size;
>> +
>> +               ptr = qcomtee_msg_offset_to_ptr(msg, off);
>> +               /* Userspace client or kernel client!? */
>> +               if (!(u[i].flags & QCOMTEE_ARG_FLAGS_UADDR))
>> +                       memcpy(ptr, u[i].b.addr, u[i].b.size);
>> +               else if (copy_from_user(ptr, u[i].b.uaddr, u[i].b.size))
>> +                       return -EINVAL;
>> +
>> +               off += qcomtee_msg_offset_align(u[i].b.size);
>> +               ib++;
>> +       }
>> +
>> +       ob = ib;
>> +       qcomtee_arg_for_each_output_buffer(i, u) {
>> +               /* Overflow already checked in qcomtee_msg_buffers_alloc(). */
>> +               msg->args[ob].b.offset = off;
>> +               msg->args[ob].b.size = u[i].b.size;
>> +
>> +               off += qcomtee_msg_offset_align(u[i].b.size);
>> +               ob++;
>> +       }
>> +
>> +       io = ob;
>> +       qcomtee_arg_for_each_input_object(i, u) {
>> +               if (qcomtee_object_id_get(u[i].o, &msg->args[io].o)) {
>> +                       /* Put whatever we got. */
>> +                       qcomtee_object_id_put(object_id);
>> +                       for (io--; io >= ob; io--)
>> +                               qcomtee_object_id_put(msg->args[io].o);
>> +
>> +                       return -ENOSPC;
>> +               }
>> +
>> +               io++;
>> +       }
>> +
>> +       oo = io;
>> +       qcomtee_arg_for_each_output_object(i, u)
>> +               oo++;
>> +
>> +       /* Set object, operation, and argument counts. */
>> +       qcomtee_msg_init(msg, object_id, op, ib, ob, io, oo);
>> +
>> +       return 0;
>> +}
>> +
>> +/**
>> + * qcomtee_update_args() - Parse the QTEE response in the inbound buffer.
>> + * @u: array of arguments for the invocation.
>> + * @oic: context to use for the invocation.
>> + *
>> + * @u must be the same as the one used in qcomtee_prepare_msg() when
>> + * initializing the inbound buffer.
>> + *
>> + * On failure, it continues processing the QTEE message. The caller should
>> + * do the necessary cleanup, including calling qcomtee_object_put()
>> + * on the output objects.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +static int qcomtee_update_args(struct qcomtee_arg *u,
>> +                              struct qcomtee_object_invoke_ctx *oic)
>> +{
>> +       struct qcomtee_msg_object_invoke *msg;
>> +       int i, ib, ob, io, oo;
>> +       int ret = 0;
>> +
>> +       /* Use the input message buffer in 'oic'. */
>> +       msg = oic->in_msg.addr;
>> +
>> +       ib = 0;
>> +       qcomtee_arg_for_each_input_buffer(i, u)
>> +               ib++;
>> +
>> +       ob = ib;
>> +       qcomtee_arg_for_each_output_buffer(i, u) {
>> +               void *ptr;
>> +
>> +               /* QTEE can override the size to a smaller value. */
>> +               u[i].b.size = msg->args[ob].b.size;
>> +
>> +               ptr = qcomtee_msg_offset_to_ptr(msg, msg->args[ob].b.offset);
>> +               /* Userspace client or kernel client!? */
>> +               if (!(u[i].flags & QCOMTEE_ARG_FLAGS_UADDR))
>> +                       memcpy(u[i].b.addr, ptr, u[i].b.size);
>> +               else if (copy_to_user(u[i].b.uaddr, ptr, u[i].b.size))
>> +                       ret = -EINVAL;
>> +
>> +               ob++;
>> +       }
>> +
>> +       io = ob;
>> +       qcomtee_arg_for_each_input_object(i, u)
>> +               io++;
>> +
>> +       oo = io;
>> +       qcomtee_arg_for_each_output_object(i, u) {
>> +               if (qcomtee_object_qtee_init(oic, &u[i].o, msg->args[oo].o))
>> +                       ret = -EINVAL;
>> +
>> +               oo++;
>> +       }
>> +
>> +       return ret;
>> +}
>> +
>> +/**
>> + * qcomtee_prepare_args() - Parse the QTEE request from the outbound buffer.
>> + * @oic: context to use for the invocation.
>> + *
>> + * It initializes &qcomtee_object_invoke_ctx->u based on the QTEE request in
>> + * the outbound buffer. It sets %QCOMTEE_ARG_TYPE_INV at the end of the array.
>> + *
>> + * On failure, it continues processing the QTEE message. The caller should
>> + * do the necessary cleanup, including calling qcomtee_object_put()
>> + * on the input objects.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +static int qcomtee_prepare_args(struct qcomtee_object_invoke_ctx *oic)
>> +{
>> +       struct qcomtee_msg_callback *msg;
>> +       union qcomtee_msg_arg *arg;
>> +       int i, ret = 0;
>> +
>> +       /* Use the output message buffer in 'oic'. */
>> +       msg = oic->out_msg.addr;
>> +
>> +       qcomtee_msg_for_each_input_buffer(i, msg) {
>> +               arg = &msg->args[i];
>> +               oic->u[i].b.addr =
>> +                       qcomtee_msg_offset_to_ptr(msg, arg->b.offset);
>> +               oic->u[i].b.size = arg->b.size;
>> +               oic->u[i].type = QCOMTEE_ARG_TYPE_IB;
>> +       }
>> +
>> +       qcomtee_msg_for_each_output_buffer(i, msg) {
>> +               arg = &msg->args[i];
>> +               oic->u[i].b.addr =
>> +                       qcomtee_msg_offset_to_ptr(msg, arg->b.offset);
>> +               oic->u[i].b.size = arg->b.size;
>> +               oic->u[i].type = QCOMTEE_ARG_TYPE_OB;
>> +       }
>> +
>> +       qcomtee_msg_for_each_input_object(i, msg) {
>> +               if (qcomtee_object_qtee_init(oic, &oic->u[i].o, msg->args[i].o))
>> +                       ret = -EINVAL;
>> +
>> +               oic->u[i].type = QCOMTEE_ARG_TYPE_IO;
>> +       }
>> +
>> +       qcomtee_msg_for_each_output_object(i, msg)
>> +               oic->u[i].type = QCOMTEE_ARG_TYPE_OO;
>> +
>> +       /* End of Arguments. */
>> +       oic->u[i].type = QCOMTEE_ARG_TYPE_INV;
>> +
>> +       return ret;
>> +}
>> +
>> +static int qcomtee_update_msg(struct qcomtee_object_invoke_ctx *oic)
>> +{
>> +       struct qcomtee_msg_callback *msg;
>> +       int i, ib, ob, io, oo;
>> +
>> +       /* Use the output message buffer in 'oic'. */
>> +       msg = oic->out_msg.addr;
>> +
>> +       ib = 0;
>> +       qcomtee_arg_for_each_input_buffer(i, oic->u)
>> +               ib++;
>> +
>> +       ob = ib;
>> +       qcomtee_arg_for_each_output_buffer(i, oic->u) {
>> +               /* Only reduce size; never increase it. */
>> +               if (msg->args[ob].b.size < oic->u[i].b.size)
>> +                       return -EINVAL;
>> +
>> +               msg->args[ob].b.size = oic->u[i].b.size;
>> +               ob++;
>> +       }
>> +
>> +       io = ob;
>> +       qcomtee_arg_for_each_input_object(i, oic->u)
>> +               io++;
>> +
>> +       oo = io;
>> +       qcomtee_arg_for_each_output_object(i, oic->u) {
>> +               if (qcomtee_object_id_get(oic->u[i].o, &msg->args[oo].o)) {
>> +                       /* Put whatever we got. */
>> +                       for (oo--; oo >= io; oo--)
>> +                               qcomtee_object_id_put(msg->args[oo].o);
>> +
>> +                       return -ENOSPC;
>> +               }
>> +
>> +               oo++;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +/* Invoke a callback object. */
>> +static void qcomtee_cb_object_invoke(struct qcomtee_object_invoke_ctx *oic,
>> +                                    struct qcomtee_msg_callback *msg)
>> +{
>> +       int i, errno;
>> +       u32 op;
>> +
>> +       /* Get the object being invoked. */
>> +       unsigned int object_id = msg->cxt;
>> +       struct qcomtee_object *object;
>> +
>> +       /* QTEE cannot invoke a NULL object or objects it hosts. */
>> +       if (qcomtee_object_type(object_id) == QCOMTEE_OBJECT_TYPE_NULL ||
>> +           qcomtee_object_type(object_id) == QCOMTEE_OBJECT_TYPE_TEE) {
>> +               errno = -EINVAL;
>> +               goto out;
>> +       }
>> +
>> +       object = qcomtee_local_object_get(object_id);
>> +       if (object == NULL_QCOMTEE_OBJECT) {
>> +               errno = -EINVAL;
>> +               goto out;
>> +       }
>> +
>> +       oic->object = object;
>> +
>> +       /* Filter bits used by transport. */
>> +       op = msg->op & QCOMTEE_MSG_OBJECT_OP_MASK;
>> +
>> +       switch (op) {
>> +       case QCOMTEE_MSG_OBJECT_OP_RELEASE:
>> +               qcomtee_object_id_put(object_id);
>> +               qcomtee_object_put(object);
>> +               errno = 0;
>> +
>> +               break;
>> +       case QCOMTEE_MSG_OBJECT_OP_RETAIN:
>> +               qcomtee_object_get(object);
>> +               errno = 0;
>> +
>> +               break;
>> +       default:
>> +               errno = qcomtee_prepare_args(oic);
>> +               if (errno) {
>> +                       /* Release any object that arrived as input. */
>> +                       qcomtee_arg_for_each_input_buffer(i, oic->u)
>> +                               qcomtee_object_put(oic->u[i].o);
>> +
>> +                       break;
>> +               }
>> +
>> +               errno = object->ops->dispatch(oic, object, op, oic->u);
>> +               if (!errno) {
>> +                       /* On success, notify at the appropriate time. */
>> +                       oic->flags |= QCOMTEE_OIC_FLAG_NOTIFY;
>> +               }
>> +       }
>> +
>> +out:
>> +
>> +       oic->errno = errno;
>> +}
>> +
>> +/**
>> + * qcomtee_qtee_objects_put() - Put the callback objects in the argument array.
>> + * @u: array of arguments.
>> + *
>> + * When qcomtee_object_do_invoke_internal() is successfully invoked,
>> + * QTEE takes ownership of the callback objects. If the invocation fails,
>> + * qcomtee_object_do_invoke_internal() calls qcomtee_qtee_objects_put()
>> + * to mimic the release of callback objects by QTEE.
>> + */
>> +static void qcomtee_qtee_objects_put(struct qcomtee_arg *u)
>> +{
>> +       int i;
>> +
>> +       qcomtee_arg_for_each_input_object(i, u) {
>> +               if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)
>> +                       qcomtee_object_put(u[i].o);
>> +       }
>> +}
>> +
>> +/**
>> + * qcomtee_object_do_invoke_internal() - Submit an invocation for an object.
>> + * @oic: context to use for the current invocation.
>> + * @object: object being invoked.
>> + * @op: requested operation on the object.
>> + * @u: array of arguments for the current invocation.
>> + * @result: result returned from QTEE.
>> + *
>> + * The caller is responsible for keeping track of the refcount for each
>> + * object, including @object. On return, the caller loses ownership of all
>> + * input objects of type %QCOMTEE_OBJECT_TYPE_CB.
>> + *
>> + * Return: On success, returns 0. On error, returns -EAGAIN if invocation
>> + * failed and the user may retry the invocation, -ENODEV on fatal failure.
>> + */
>> +int qcomtee_object_do_invoke_internal(struct qcomtee_object_invoke_ctx *oic,
>> +                                     struct qcomtee_object *object, u32 op,
>> +                                     struct qcomtee_arg *u, int *result)
>> +{
>> +       struct qcomtee_msg_callback *cb_msg;
>> +       struct qcomtee_object *qto;
>> +       int i, ret, errno;
>> +       u64 res_type;
>> +
>> +       /* Allocate inbound and outbound buffers. */
>> +       if (qcomtee_msg_buffers_alloc(oic, u)) {
>> +               qcomtee_qtee_objects_put(u);
>> +
>> +               return -EAGAIN;
>> +       }
>> +
>> +       if (qcomtee_prepare_msg(oic, object, op, u)) {
>> +               qcomtee_qtee_objects_put(u);
>> +
>> +               ret = -EAGAIN;
>> +               goto out;
>> +       }
>> +
>> +       /* Use input message buffer in 'oic'. */
>> +       cb_msg = oic->out_msg.addr;
>> +
>> +       while (1) {
>> +               if (oic->flags & QCOMTEE_OIC_FLAG_BUSY) {
>> +                       errno = oic->errno;
>> +                       if (!errno)
>> +                               errno = qcomtee_update_msg(oic);
>> +                       qcomtee_msg_set_result(cb_msg, errno);
>> +               }
>> +
>> +               /* Invoke the remote object. */
>> +               ret = qcomtee_object_invoke_ctx_invoke(oic, result, &res_type);
>> +
>> +               if (oic->flags & QCOMTEE_OIC_FLAG_BUSY) {
>> +                       qto = oic->object;
>> +                       if (qto) {
>> +                               if (oic->flags & QCOMTEE_OIC_FLAG_NOTIFY) {
>> +                                       /* Don't care about the exact errno. */
>> +                                       if (qto->ops->notify)
>> +                                               qto->ops->notify(oic, qto,
>> +                                                                errno || ret);
>> +                               }
>> +
>> +                               /* Get is in qcomtee_cb_object_invoke(). */
>> +                               qcomtee_object_put(qto);
>> +                       }
>> +
>> +                       oic->object = NULL_QCOMTEE_OBJECT;
>> +                       oic->flags &= ~(QCOMTEE_OIC_FLAG_BUSY |
>> +                                       QCOMTEE_OIC_FLAG_NOTIFY);
>> +               }
>> +
>> +               if (ret) {
>> +                       if (!(oic->flags & QCOMTEE_OIC_FLAG_SHARED)) {
>> +                               qcomtee_qtee_objects_put(u);
>> +
>> +                               ret = -EAGAIN;
>> +                       } else {
>> +                               /*
>> +                                * On error, there is no clean way to exit.
>> +                                * For some reason, we cannot communicate with
>> +                                * QTEE, so we cannot notify QTEE about the
>> +                                * failure and do further cleanup.
>> +                                */
>> +                               ret = -ENODEV;
>> +                       }
>> +
>> +                       goto out;
>> +
>> +               } else {
>> +                       /*
>> +                        * QTEE obtained ownership of QCOMTEE_OBJECT_TYPE_CB
>> +                        * input objects in 'u'. On further failure, QTEE is
>> +                        * responsible for releasing them.
>> +                        */
>> +                       oic->flags |= QCOMTEE_OIC_FLAG_SHARED;
>> +               }
>> +
>> +               /* Is it a callback request? */
>> +               if (res_type != QCOMTEE_RESULT_INBOUND_REQ_NEEDED) {
>> +                       if (!*result) {
>> +                               ret = qcomtee_update_args(u, oic);
>> +                               if (ret) {
>> +                                       /* Put output objects. Retry. */
>> +                                       qcomtee_arg_for_each_output_object(i, u)
>> +                                               qcomtee_object_put(u[i].o);
>> +
>> +                                       ret = -EAGAIN;
>> +                               }
>> +                       }
>> +
>> +                       break;
>> +
>> +               } else {
>> +                       oic->flags |= QCOMTEE_OIC_FLAG_BUSY;
>> +
>> +                       qcomtee_fetch_async_reqs(oic);
>> +                       qcomtee_cb_object_invoke(oic, cb_msg);
>> +               }
>> +       }
>> +
>> +       qcomtee_fetch_async_reqs(oic);
>> +out:
>> +       qcomtee_msg_buffers_free(oic);
>> +
>> +       return ret;
>> +}
>> +
>> +int qcomtee_object_do_invoke(struct qcomtee_object_invoke_ctx *oic,
>> +                            struct qcomtee_object *object, u32 op,
>> +                            struct qcomtee_arg *u, int *result)
>> +{
>> +       /* User can not set bits used by transport. */
>> +       if (op & ~QCOMTEE_MSG_OBJECT_OP_MASK)
>> +               return -EINVAL;
>> +
>> +       /* User can only invoke QTEE hosted objects. */
>> +       if (typeof_qcomtee_object(object) != QCOMTEE_OBJECT_TYPE_TEE &&
>> +           typeof_qcomtee_object(object) != QCOMTEE_OBJECT_TYPE_ROOT)
>> +               return -EINVAL;
>> +
>> +       /* User cannot directly issue these operations to QTEE. */
>> +       if (op == QCOMTEE_MSG_OBJECT_OP_RELEASE)
>> +               return -EINVAL;
>> +
>> +       return qcomtee_object_do_invoke_internal(oic, object, op, u, result);
>> +}
>> +EXPORT_SYMBOL_GPL(qcomtee_object_do_invoke);
>> diff --git a/drivers/tee/qcomtee/qcom_scm.c b/drivers/tee/qcomtee/qcom_scm.c
>> new file mode 100644
>> index 000000000000..38a3d080f86d
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/qcom_scm.c
>> @@ -0,0 +1,38 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#include <linux/firmware/qcom/qcom_scm.h>
>> +
>> +#include "qcomtee_private.h"
>> +
>> +int qcomtee_object_invoke_ctx_invoke(struct qcomtee_object_invoke_ctx *oic,
>> +                                    int *result, u64 *res_type)
>> +{
>> +       phys_addr_t out_msg_paddr;
>> +       phys_addr_t in_msg_paddr;
>> +       int ret;
>> +       u64 res;
>> +
>> +       tee_shm_get_pa(oic->out_shm, 0, &out_msg_paddr);
>> +       tee_shm_get_pa(oic->in_shm, 0, &in_msg_paddr);
>> +       if (!(oic->flags & QCOMTEE_OIC_FLAG_BUSY)) {
>> +               /* Direct QTEE object invocation. */
>> +               ret = qcom_scm_qtee_invoke_smc(in_msg_paddr, oic->in_msg.size,
>> +                                              out_msg_paddr, oic->out_msg.size,
>> +                                              &res, res_type);
>> +       } else {
>> +               /* Submit callback response. */
>> +               ret = qcom_scm_qtee_callback_response(out_msg_paddr,
>> +                                                     oic->out_msg.size,
>> +                                                     &res, res_type);
>> +       }
>> +
>> +       if (ret)
>> +               pr_err("QTEE returned with %d.\n", ret);
>> +       else
>> +               *result = (int)res;
>> +
>> +       return ret;
>> +}
>> diff --git a/drivers/tee/qcomtee/qcomtee_msg.h b/drivers/tee/qcomtee/qcomtee_msg.h
>> new file mode 100644
>> index 000000000000..33a6b426153c
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/qcomtee_msg.h
>> @@ -0,0 +1,239 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#ifndef QCOMTEE_MSG_H
>> +#define QCOMTEE_MSG_H
>> +
>> +#include <linux/firmware/qcom/qcom_tee.h>
>> +
>> +/**
>> + * DOC: ''Qualcomm TEE'' (QTEE) Transport Message
>> + *
>> + * There are two buffers shared with QTEE: inbound and outbound buffers.
>> + * The inbound buffer is used for direct object invocation, and the outbound
>> + * buffer is used to make a request from QTEE to the kernel; i.e., a callback
>> + * request.
>> + *
>> + * The unused tail of the outbound buffer is also used for sending and
>> + * receiving asynchronous messages. An asynchronous message is independent of
>> + * the current object invocation (i.e., contents of the inbound buffer) or
>> + * callback request (i.e., the head of the outbound buffer); see
>> + * qcomtee_get_async_buffer(). It is used by endpoints (QTEE or kernel) as an
>> + * optimization to reduce the number of context switches between the secure and
>> + * non-secure worlds.
>> + *
>> + * For instance, QTEE never sends an explicit callback request to release an
>> + * object in the kernel. Instead, it sends asynchronous release messages in the
>> + * outbound buffer when QTEE returns from the previous direct object invocation,
>> + * or appends asynchronous release messages after the current callback request.
>> + *
>> + * QTEE supports two types of arguments in a message: buffer and object
>> + * arguments. Depending on the direction of data flow, they could be input
>> + * buffer (IO) to QTEE, output buffer (OB) from QTEE, input object (IO) to QTEE,
>> + * or output object (OO) from QTEE. Object arguments hold object IDs. Buffer
>> + * arguments hold (offset, size) pairs into the inbound or outbound buffers.
>> + *
>> + * QTEE holds an object table for objects it hosts and exposes to the kernel.
>> + * An object ID is an index to the object table in QTEE.
>> + *
>> + * For the direct object invocation message format in the inbound buffer, see
>> + * &struct qcomtee_msg_object_invoke. For the callback request message format
>> + * in the outbound buffer, see &struct qcomtee_msg_callback. For the message
>> + * format for asynchronous messages in the outbound buffer, see
>> + * &struct qcomtee_async_msg_hdr.
>> + */
>> +
>> +/**
>> + * define QCOMTEE_MSG_OBJECT_NS_BIT - Non-secure bit
>> + *
>> + * Object ID is a globally unique 32-bit number. IDs referencing objects
>> + * in the kernel should have %QCOMTEE_MSG_OBJECT_NS_BIT set.
>> + */
>> +#define QCOMTEE_MSG_OBJECT_NS_BIT BIT(31)
>> +
>> +/* Static object IDs recognized by QTEE. */
>> +#define QCOMTEE_MSG_OBJECT_NULL (0U)
>> +#define QCOMTEE_MSG_OBJECT_ROOT (1U)
>> +
>> +/* Definitions from QTEE as part of the transport protocol. */
>> +
>> +/* qcomtee_msg_arg is an argument as recognized by QTEE. */
>> +union qcomtee_msg_arg {
>> +       struct {
>> +               u32 offset;
>> +               u32 size;
>> +       } b;
>> +       u32 o;
>> +};
>> +
>> +/* BI and BO payloads in QTEE messages should be at 64-bit boundaries. */
>> +#define qcomtee_msg_offset_align(o) ALIGN((o), sizeof(u64))
>> +
>> +/* Operations for objects are 32-bit. Transport uses the upper 16 bits. */
>> +#define QCOMTEE_MSG_OBJECT_OP_MASK GENMASK(15, 0)
>> +
>> +/* Reserved Operation IDs sent to QTEE: */
>> +/* QCOMTEE_MSG_OBJECT_OP_RELEASE - Reduces the refcount and releases the object.
>> + * QCOMTEE_MSG_OBJECT_OP_RETAIN  - Increases the refcount.
>> + *
>> + * These operation IDs are valid for all objects.
>> + */
>> +
>> +#define QCOMTEE_MSG_OBJECT_OP_RELEASE (QCOMTEE_MSG_OBJECT_OP_MASK - 0)
>> +#define QCOMTEE_MSG_OBJECT_OP_RETAIN  (QCOMTEE_MSG_OBJECT_OP_MASK - 1)
>> +
>> +/* Subset of operations supported by QTEE root object. */
>> +
>> +#define QCOMTEE_ROOT_OP_REGISTER_WITH_CREDENTIALS 5
>> +#define QCOMTEE_ROOT_OP_NOTIFY_DOMAIN_CHANGE 4
>> +#define QCOMTEE_ROOT_OP_ADCI_ACCEPT 8
>> +#define QCOMTEE_ROOT_OP_ADCI_SHUTDOWN 9
>> +
>> +/* Response types as returned from qcomtee_object_invoke_ctx_invoke(). */
>> +
>> +/* The message contains a callback request. */
>> +#define QCOMTEE_RESULT_INBOUND_REQ_NEEDED 3
>> +
>> +/**
>> + * struct qcomtee_msg_object_invoke - Direct object invocation message.
>> + * @ctx: object ID hosted in QTEE.
>> + * @op: operation for the object.
>> + * @counts: number of different types of arguments in @args.
>> + * @args: array of arguments.
>> + *
>> + * @counts consists of 4 * 4-bit fields. Bits 0 - 3 represent the number of
>> + * input buffers, bits 4 - 7 represent the number of output buffers,
>> + * bits 8 - 11 represent the number of input objects, and bits 12 - 15
>> + * represent the number of output objects. The remaining bits should be zero.
>> + *
>> + * The maximum number of arguments of each type is defined by
>> + * %QCOMTEE_ARGS_PER_TYPE.
>> + */
>> +struct qcomtee_msg_object_invoke {
>> +       u32 cxt;
>> +       u32 op;
>> +       u32 counts;
>> +       union qcomtee_msg_arg args[];
>> +};
>> +
>> +/**
>> + * struct qcomtee_msg_callback - Callback request message.
>> + * @result: result of operation @op on the object referenced by @cxt.
>> + * @cxt: object ID hosted in the kernel.
>> + * @op: operation for the object.
>> + * @counts: number of different types of arguments in @args.
>> + * @args: array of arguments.
>> + *
>> + * For details of @counts, see &qcomtee_msg_object_invoke.counts.
>> + */
>> +struct qcomtee_msg_callback {
>> +       u32 result;
>> +       u32 cxt;
>> +       u32 op;
>> +       u32 counts;
>> +       union qcomtee_msg_arg args[];
>> +};
>> +
>> +/* Offset in the message for the beginning of the buffer argument's contents. */
>> +#define qcomtee_msg_buffer_args(t, n) \
>> +       qcomtee_msg_offset_align(struct_size_t(t, args, n))
>> +/* Pointer to the beginning of a buffer argument's content at an offset. */
>> +#define qcomtee_msg_offset_to_ptr(m, off) ((void *)&((char *)(m))[(off)])
>> +
>> +/* Some helpers to manage msg.counts. */
>> +
>> +#define QCOMTEE_MSG_NUM_IB(x) ((x) & 0xfU)
>> +#define QCOMTEE_MSG_NUM_OB(x) (((x) >> 4) & 0xfU)
>> +#define QCOMTEE_MSG_NUM_IO(x) (((x) >> 8) & 0xfU)
>> +#define QCOMTEE_MSG_NUM_OO(x) (((x) >> 12) & 0xfU)
>> +
>> +#define QCOMTEE_MSG_IDX_IB(x) (0U)
>> +#define QCOMTEE_MSG_IDX_OB(x) (QCOMTEE_MSG_IDX_IB(x) + QCOMTEE_MSG_NUM_IB(x))
>> +#define QCOMTEE_MSG_IDX_IO(x) (QCOMTEE_MSG_IDX_OB(x) + QCOMTEE_MSG_NUM_OB(x))
>> +#define QCOMTEE_MSG_IDX_OO(x) (QCOMTEE_MSG_IDX_IO(x) + QCOMTEE_MSG_NUM_IO(x))
>> +
>> +#define qcomtee_msg_for_each(i, c, type)    \
>> +       for (i = QCOMTEE_MSG_IDX_##type(c); \
>> +            i < (QCOMTEE_MSG_IDX_##type(c) + QCOMTEE_MSG_NUM_##type(c)); i++)
>> +
>> +#define qcomtee_msg_for_each_input_buffer(i, m) \
>> +       qcomtee_msg_for_each(i, (m)->counts, IB)
>> +#define qcomtee_msg_for_each_output_buffer(i, m) \
>> +       qcomtee_msg_for_each(i, (m)->counts, OB)
>> +#define qcomtee_msg_for_each_input_object(i, m) \
>> +       qcomtee_msg_for_each(i, (m)->counts, IO)
>> +#define qcomtee_msg_for_each_output_object(i, m) \
>> +       qcomtee_msg_for_each(i, (m)->counts, OO)
>> +
>> +/* Sum of arguments in a message. */
>> +#define qcomtee_msg_args(m) \
>> +       (QCOMTEE_MSG_IDX_OO((m)->counts) + QCOMTEE_MSG_NUM_OO((m)->counts))
>> +
>> +static inline void qcomtee_msg_init(struct qcomtee_msg_object_invoke *msg,
>> +                                   u32 cxt, u32 op, int in_buffer,
>> +                                   int out_buffer, int in_object,
>> +                                   int out_object)
>> +{
>> +       msg->counts |= (in_buffer & 0xfU);
>> +       msg->counts |= ((out_buffer - in_buffer) & 0xfU) << 4;
>> +       msg->counts |= ((in_object - out_buffer) & 0xfU) << 8;
>> +       msg->counts |= ((out_object - in_object) & 0xfU) << 12;
>> +       msg->cxt = cxt;
>> +       msg->op = op;
>> +}
>> +
>> +/* Generic error codes. */
>> +#define QCOMTEE_MSG_OK                 0    /* non-specific success code. */
>> +#define QCOMTEE_MSG_ERROR              1    /* non-specific error. */
>> +#define QCOMTEE_MSG_ERROR_INVALID      2    /* unsupported/unrecognized request. */
>> +#define QCOMTEE_MSG_ERROR_SIZE_IN      3    /* supplied buffer/string too large. */
>> +#define QCOMTEE_MSG_ERROR_SIZE_OUT     4    /* supplied output buffer too small. */
>> +#define QCOMTEE_MSG_ERROR_USERBASE     10   /* start of user-defined error range. */
>> +
>> +/* Transport layer error codes. */
>> +#define QCOMTEE_MSG_ERROR_DEFUNCT      -90  /* object no longer exists. */
>> +#define QCOMTEE_MSG_ERROR_ABORT                -91  /* calling thread must exit. */
>> +#define QCOMTEE_MSG_ERROR_BADOBJ       -92  /* invalid object context. */
>> +#define QCOMTEE_MSG_ERROR_NOSLOTS      -93  /* caller's object table full. */
>> +#define QCOMTEE_MSG_ERROR_MAXARGS      -94  /* too many args. */
>> +#define QCOMTEE_MSG_ERROR_MAXDATA      -95  /* buffers too large. */
>> +#define QCOMTEE_MSG_ERROR_UNAVAIL      -96  /* the request could not be processed. */
>> +#define QCOMTEE_MSG_ERROR_KMEM         -97  /* kernel out of memory. */
>> +#define QCOMTEE_MSG_ERROR_REMOTE       -98  /* local method sent to remote object. */
>> +#define QCOMTEE_MSG_ERROR_BUSY         -99  /* Object is busy. */
>> +#define QCOMTEE_MSG_ERROR_TIMEOUT      -103 /* Call Back Object invocation timed out. */
>> +
>> +static inline void qcomtee_msg_set_result(struct qcomtee_msg_callback *cb_msg,
>> +                                         int err)
>> +{
>> +       if (!err) {
>> +               cb_msg->result = QCOMTEE_MSG_OK;
>> +       } else if (err < 0) {
>> +               /* If err < 0, then it is a transport error. */
>> +               switch (err) {
>> +               case -ENOMEM:
>> +                       cb_msg->result = QCOMTEE_MSG_ERROR_KMEM;
>> +                       break;
>> +               case -ENODEV:
>> +                       cb_msg->result = QCOMTEE_MSG_ERROR_DEFUNCT;
>> +                       break;
>> +               case -ENOSPC:
>> +               case -EBUSY:
>> +                       cb_msg->result = QCOMTEE_MSG_ERROR_BUSY;
>> +                       break;
>> +               case -EBADF:
>> +               case -EINVAL:
>> +                       cb_msg->result = QCOMTEE_MSG_ERROR_UNAVAIL;
>> +                       break;
>> +               default:
>> +                       cb_msg->result = QCOMTEE_MSG_ERROR;
>> +               }
>> +       } else {
>> +               /* If err > 0, then it is user defined error, pass it as is. */
>> +               cb_msg->result = err;
>> +       }
>> +}
>> +
>> +#endif /* QCOMTEE_MSG_H */
>> diff --git a/drivers/tee/qcomtee/qcomtee_private.h b/drivers/tee/qcomtee/qcomtee_private.h
>> new file mode 100644
>> index 000000000000..ab3acad40359
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/qcomtee_private.h
>> @@ -0,0 +1,222 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#ifndef QCOMTEE_PRIVATE_H
>> +#define QCOMTEE_PRIVATE_H
>> +
>> +#include <linux/firmware/qcom/qcom_tee.h>
>> +#include <linux/kobject.h>
>> +#include <linux/tee_core.h>
>> +
>> +#include "qcomtee_msg.h"
>> +
>> +/* Flags relating to object reference. */
>> +#define QCOMTEE_OBJREF_FLAG_TEE BIT(0)
>> +#define QCOMTEE_OBJREF_FLAG_USER BIT(1)
>> +
>> +/**
>> + * struct qcomtee - Main service struct.
>> + * @teedev: client device.
>> + * @pool: shared memory pool.
>> + * @ctx: driver private context.
>> + * @wq: workqueue for QTEE async operations.
>> + */
>> +struct qcomtee {
>> +       struct tee_device *teedev;
>> +       struct tee_shm_pool *pool;
>> +       struct tee_context *ctx;
>> +       struct workqueue_struct *wq;
>> +};
>> +
>> +struct qcomtee_object *qcomtee_idx_erase(u32 idx);
>> +void qcomtee_qtee_object_free(struct qcomtee_object *object);
>> +void qcomtee_fetch_async_reqs(struct qcomtee_object_invoke_ctx *oic);
>> +void qcomtee_release_tee_object(struct qcomtee_object *object);
>> +
>> +struct tee_shm_pool *qcomtee_shm_pool_alloc(void);
>> +void qcomtee_msg_buffers_free(struct qcomtee_object_invoke_ctx *oic);
>> +int qcomtee_msg_buffers_alloc(struct qcomtee_object_invoke_ctx *oic,
>> +                             struct qcomtee_arg *u);
>> +
>> +int qcomtee_object_invoke_ctx_invoke(struct qcomtee_object_invoke_ctx *oic,
>> +                                    int *result, u64 *res_type);
>> +
>> +/**
>> + * qcomtee_object_do_invoke_internal() - Submit an invocation for an object.
>> + * @oic: context to use for the current invocation.
>> + * @object: object being invoked.
>> + * @op: requested operation on the object.
>> + * @u: array of arguments for the current invocation.
>> + * @result: result returned from QTEE.
>> + *
>> + * The caller is responsible for keeping track of the refcount for each
>> + * object, including @object. On return, the caller loses ownership of all
>> + * input objects of type %QCOMTEE_OBJECT_TYPE_CB.
>> + *
>> + * Return: On success, returns 0. On error, returns -EAGAIN if invocation
>> + * failed and the user may retry the invocation, -ENODEV on fatal failure.
>> + */
>> +int qcomtee_object_do_invoke_internal(struct qcomtee_object_invoke_ctx *oic,
>> +                                     struct qcomtee_object *object, u32 op,
>> +                                     struct qcomtee_arg *u, int *result);
>> +
>> +/**
>> + * struct qcomtee_context_data - Clients' or supplicants' context.
>> + * @qtee_objects_idr: QTEE objects in this context.
>> + * @qtee_lock: spinlock for @qtee_objects_idr.
>> + * @reqs_idr: requests currently being processed in this context.
>> + * @reqs_list: FIFO for requests.
>> + * @reqs_lock: mutex for @reqs_idr, @reqs_list and request states.
>> + * @req_c: completion used when the supplicant is waiting for requests.
>> + * @released: state of this context.
>> + */
>> +struct qcomtee_context_data {
>> +       struct idr qtee_objects_idr;
>> +       /* Synchronize access to @qtee_objects_idr. */
>> +       spinlock_t qtee_lock;
>> +
>> +       struct idr reqs_idr;
>> +       struct list_head reqs_list;
>> +       /* Synchronize access to @reqs_idr, @reqs_list and updating requests states. */
>> +       struct mutex reqs_lock;
>> +
>> +       struct completion req_c;
>> +
>> +       int released;
> 
> Should this rather be a bool, or an enum depending on how many
> different states it's supposed to have?
> 

Only two state, will make it bool.

>> +};
>> +
>> +/**
>> + * qcomtee_context_add_qtee_object() - Add a QTEE object to the context.
>> + * @param: TEE parameter representing @object.
>> + * @object: QTEE object.
>> + * @ctx: context to add the object.
>> + *
>> + * It assumes @object is %QCOMTEE_OBJECT_TYPE_TEE and the caller has already
>> + * issued qcomtee_object_get() for @object.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_context_add_qtee_object(struct tee_param *param,
>> +                                   struct qcomtee_object *object,
>> +                                   struct tee_context *ctx);
>> +
>> +/* Retrieve the QTEE object added with qcomtee_context_add_qtee_object(). */
>> +int qcomtee_context_find_qtee_object(struct qcomtee_object **object,
>> +                                    struct tee_param *param,
>> +                                    struct tee_context *ctx);
>> +
>> +/**
>> + * qcomtee_context_del_qtee_object() - Delete a QTEE object from the context.
>> + * @param: TEE parameter representing @object.
>> + * @ctx: context for deleting the object.
>> + *
>> + * The @param has been initialized by qcomtee_context_add_qtee_object().
>> + */
>> +void qcomtee_context_del_qtee_object(struct tee_param *param,
>> +                                    struct tee_context *ctx);
>> +
>> +/**
>> + * qcomtee_objref_to_arg() - Convert OBJREF parameter to QTEE argument.
>> + * @arg: QTEE argument.
>> + * @param: TEE parameter.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * It assumes @param is an OBJREF.
>> + * It does not set @arg.type; the caller should initialize it to a correct
>> + * &enum qcomtee_arg_type value. It gets the object's refcount in @arg;
>> + * the caller should manage to put it afterward.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_objref_to_arg(struct qcomtee_arg *arg, struct tee_param *param,
>> +                         struct tee_context *ctx);
>> +
>> +/**
>> + * qcomtee_objref_from_arg() - Convert QTEE argument to OBJREF param.
>> + * @param: TEE parameter.
>> + * @arg: QTEE argument.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * It assumes @arg is of %QCOMTEE_ARG_TYPE_IO or %QCOMTEE_ARG_TYPE_OO.
>> + * It does not set @param.attr; the caller should initialize it to a
>> + * correct type.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_objref_from_arg(struct tee_param *param, struct qcomtee_arg *arg,
>> +                           struct tee_context *ctx);
>> +
>> +/* OBJECTS: */
>> +
>> +/* (1) User Object API. */
>> +
>> +/* Is it a user object? */
>> +int is_qcomtee_user_object(struct qcomtee_object *object);
>> +
>> +/* Set the user object's 'notify on release' flag. */
>> +void qcomtee_user_object_set_notify(struct qcomtee_object *object, bool notify);
>> +
>> +/* This is called when there are no more users for the ctxdata. */
>> +void qcomtee_requests_destroy(struct qcomtee_context_data *ctxdata);
>> +
>> +/**
>> + * qcomtee_user_param_to_object() - OBJREF parameter to &struct qcomtee_object.
>> + * @object: object returned.
>> + * @param: TEE parameter.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * @param is an OBJREF with %QCOMTEE_OBJREF_FLAG_USER flags.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_user_param_to_object(struct qcomtee_object **object,
>> +                                struct tee_param *param,
>> +                                struct tee_context *ctx);
>> +
>> +/* Reverse what qcomtee_user_param_to_object() does. */
>> +int qcomtee_user_param_from_object(struct tee_param *param,
>> +                                  struct qcomtee_object *object,
>> +                                  struct tee_context *ctx);
>> +
>> +struct qcomtee_user_object_request_data {
>> +       int id; /* ID assigned to the request. */
>> +       u64 object_id; /* Object ID being invoked by QTEE. */
>> +       u32 op; /* Requested operation on object. */
>> +       int np; /* Number of parameters in the request.*/
>> +};
>> +
>> +/**
>> + * qcomtee_user_object_select() - Select a request for a user object.
>> + * @ctx: context to look for a user object.
>> + * @params: parameters for @op.
>> + * @num_params: number of elements in the parameter array.
>> + * @uaddr: user buffer for output UBUF parameters.
>> + * @size: size of user buffer @uaddr.
>> + * @data: information for the selected request.
>> + *
>> + * @params is filled along with @data for the selected request.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_user_object_select(struct tee_context *ctx,
>> +                              struct tee_param *params, int num_params,
>> +                              void __user *uaddr, size_t size,
>> +                              struct qcomtee_user_object_request_data *data);
>> +
>> +/**
>> + * qcomtee_user_object_submit() - Submit a response for a user object.
>> + * @ctx: context to look for a user object.
>> + * @params: returned parameters.
>> + * @num_params: number of elements in the parameter array.
>> + * @req_id: request ID for the response.
>> + * @errno: result of user object invocation.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_user_object_submit(struct tee_context *ctx,
>> +                              struct tee_param *params, int num_params,
>> +                              int req_id, int errno);
>> +
>> +#endif /* QCOMTEE_PRIVATE_H */
>> diff --git a/drivers/tee/qcomtee/release.c b/drivers/tee/qcomtee/release.c
>> new file mode 100644
>> index 000000000000..7d149ef3d26f
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/release.c
>> @@ -0,0 +1,48 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#include "qcomtee_private.h"
>> +
>> +static void qcomtee_destroy_user_object(struct work_struct *work)
>> +{
>> +       struct qcomtee_object *object;
>> +       struct qcomtee *qcomtee;
>> +       int ret, result;
>> +
>> +       static struct qcomtee_object_invoke_ctx oic;
>> +       /* RELEASE does not require any argument. */
>> +       static struct qcomtee_arg args[] = { { .type = QCOMTEE_ARG_TYPE_INV } };
>> +
>> +       object = container_of(work, struct qcomtee_object, work);
>> +       qcomtee = tee_get_drvdata(object->info.qcomtee_async_ctx->teedev);
>> +       /* Get the TEE context used for asynchronous operations. */
>> +       oic.ctx = object->info.qcomtee_async_ctx;
>> +
>> +       ret = qcomtee_object_do_invoke_internal(&oic, object,
>> +                                               QCOMTEE_MSG_OBJECT_OP_RELEASE,
>> +                                               args, &result);
>> +
>> +       /* Is it safe to retry the release? */
>> +       if (ret == -EAGAIN) {
>> +               queue_work(qcomtee->wq, &object->work);
>> +       } else {
>> +               if (ret || result)
>> +                       pr_err("%s: %s release failed, ret = %d (%x).\n",
>> +                              __func__, qcomtee_object_name(object), ret,
>> +                              result);
>> +
>> +               qcomtee_qtee_object_free(object);
>> +       }
>> +}
>> +
>> +/* qcomtee_release_tee_object puts object in release work queue. */
>> +void qcomtee_release_tee_object(struct qcomtee_object *object)
>> +{
>> +       struct qcomtee *qcomtee =
>> +               tee_get_drvdata(object->info.qcomtee_async_ctx->teedev);
>> +
>> +       INIT_WORK(&object->work, qcomtee_destroy_user_object);
>> +       queue_work(qcomtee->wq, &object->work);
>> +}
>> diff --git a/drivers/tee/qcomtee/shm.c b/drivers/tee/qcomtee/shm.c
>> new file mode 100644
>> index 000000000000..998aabe96434
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/shm.c
>> @@ -0,0 +1,149 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>> +
>> +#include <linux/firmware/qcom/qcom_tzmem.h>
>> +#include <linux/mm.h>
>> +
>> +#include "qcomtee_msg.h"
>> +#include "qcomtee_private.h"
>> +
>> +/**
>> + * define MAX_OUTBOUND_BUFFER_SIZE - Maximum size of outbound buffers.
>> + *
>> + * The size of outbound buffer depends on QTEE callback requests.
>> + * If an invocation requires any size larger than %MAX_OUTBOUND_BUFFER_SIZE,
>> + * the user should probably use some other form of shared memory with QTEE.
>> + */
>> +#define MAX_OUTBOUND_BUFFER_SIZE SZ_4K
>> +
>> +/* Same as %MAX_OUTBOUND_BUFFER_SIZE but for inbound buffer. */
>> +#define MAX_INBOUND_BUFFER_SIZE SZ_4M
>> +
>> +/**
>> + * qcomtee_msg_buffers_alloc() - Allocate inbound and outbound buffers.
>> + * @oic: context to use for the current invocation.
>> + * @u: array of arguments for the current invocation.
>> + *
>> + * It calculates the size of inbound and outbound buffers based on the
>> + * arguments in @u. It allocates the buffers from the teedev pool.
>> + *
>> + * Return: On success, returns 0. On error, returns < 0.
>> + */
>> +int qcomtee_msg_buffers_alloc(struct qcomtee_object_invoke_ctx *oic,
>> +                             struct qcomtee_arg *u)
>> +{
>> +       struct tee_context *ctx = oic->ctx;
>> +       struct tee_shm *shm;
>> +       size_t size;
>> +       int i;
>> +
>> +       /* Start offset in a message for buffer arguments. */
>> +       size = qcomtee_msg_buffer_args(struct qcomtee_msg_object_invoke,
>> +                                      qcomtee_args_len(u));
>> +       if (size > MAX_INBOUND_BUFFER_SIZE)
>> +               return -EINVAL;
>> +
>> +       /* Add size of IB arguments. */
>> +       qcomtee_arg_for_each_input_buffer(i, u) {
>> +               size = size_add(size, qcomtee_msg_offset_align(u[i].b.size));
>> +               if (size > MAX_INBOUND_BUFFER_SIZE)
>> +                       return -EINVAL;
>> +       }
>> +
>> +       /* Add size of OB arguments. */
>> +       qcomtee_arg_for_each_output_buffer(i, u) {
>> +               size = size_add(size, qcomtee_msg_offset_align(u[i].b.size));
>> +               if (size > MAX_INBOUND_BUFFER_SIZE)
>> +                       return -EINVAL;
>> +       }
>> +
>> +       shm = tee_shm_alloc_priv_buf(ctx, size);
>> +       if (IS_ERR(shm))
>> +               return PTR_ERR(shm);
>> +
>> +       /* Allocate inbound buffer. */
>> +       oic->in_shm = shm;
>> +       shm = tee_shm_alloc_priv_buf(ctx, MAX_OUTBOUND_BUFFER_SIZE);
>> +       if (IS_ERR(shm)) {
>> +               tee_shm_free(oic->in_shm);
>> +
>> +               return PTR_ERR(shm);
>> +       }
>> +       /* Allocate outbound buffer. */
>> +       oic->out_shm = shm;
>> +
>> +       oic->in_msg.addr = tee_shm_get_va(oic->in_shm, 0);
>> +       oic->in_msg.size = tee_shm_get_size(oic->in_shm);
>> +       oic->out_msg.addr = tee_shm_get_va(oic->out_shm, 0);
>> +       oic->out_msg.size = tee_shm_get_size(oic->out_shm);
>> +       /* QTEE assume unused buffers are zeroed. */
>> +       memzero_explicit(oic->in_msg.addr, oic->in_msg.size);
>> +       memzero_explicit(oic->out_msg.addr, oic->out_msg.size);
>> +
>> +       return 0;
>> +}
>> +
>> +void qcomtee_msg_buffers_free(struct qcomtee_object_invoke_ctx *oic)
>> +{
>> +       tee_shm_free(oic->in_shm);
>> +       tee_shm_free(oic->out_shm);
>> +}
>> +
>> +/* Dynamic shared memory pool based on tee_dyn_shm_alloc_helper(). */
>> +
>> +static int qcomtee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
>> +                               struct page **pages, size_t num_pages,
>> +                               unsigned long start)
>> +{
>> +       return qcom_tzmem_shm_bridge_create(shm->paddr, shm->size,
>> +                                           &shm->sec_world_id);
>> +}
>> +
>> +static int qcomtee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
>> +{
>> +       qcom_tzmem_shm_bridge_delete(shm->sec_world_id);
>> +
>> +       return 0;
>> +}
>> +
>> +static int pool_op_alloc(struct tee_shm_pool *pool, struct tee_shm *shm,
>> +                        size_t size, size_t align)
>> +{
>> +       if (!(shm->flags & TEE_SHM_PRIV))
>> +               return -ENOMEM;
>> +
>> +       return tee_dyn_shm_alloc_helper(shm, size, align, qcomtee_shm_register);
>> +}
>> +
>> +static void pool_op_free(struct tee_shm_pool *pool, struct tee_shm *shm)
>> +{
>> +       tee_dyn_shm_free_helper(shm, qcomtee_shm_unregister);
>> +}
>> +
>> +static void pool_op_destroy_pool(struct tee_shm_pool *pool)
>> +{
>> +       kfree(pool);
>> +}
>> +
>> +static const struct tee_shm_pool_ops pool_ops = {
>> +       .alloc = pool_op_alloc,
>> +       .free = pool_op_free,
>> +       .destroy_pool = pool_op_destroy_pool,
>> +};
>> +
>> +struct tee_shm_pool *qcomtee_shm_pool_alloc(void)
>> +{
>> +       struct tee_shm_pool *pool;
>> +
>> +       pool = kzalloc(sizeof(*pool), GFP_KERNEL);
>> +       if (!pool)
>> +               return ERR_PTR(-ENOMEM);
>> +
>> +       pool->ops = &pool_ops;
>> +
>> +       return pool;
>> +}
>> diff --git a/drivers/tee/qcomtee/user_obj.c b/drivers/tee/qcomtee/user_obj.c
>> new file mode 100644
>> index 000000000000..95d22e720de7
>> --- /dev/null
>> +++ b/drivers/tee/qcomtee/user_obj.c
>> @@ -0,0 +1,710 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>> +
>> +#include <linux/slab.h>
>> +#include "qcomtee_private.h"
>> +
>> +/**
>> + * DOC: User Objects aka Supplicants
>> + *
>> + * Any userspace process with access to the TEE device file can behave as a
>> + * supplicant by creating a user object. Any TEE parameter of type OBJREF with
>> + * %QCOMTEE_OBJREF_FLAG_USER flag set is considered a user object.
>> + *
>> + * A supplicant uses qcomtee_user_object_select() (i.e. TEE_IOC_SUPPL_RECV) to
>> + * receive a QTEE user object request and qcomtee_user_object_submit()
>> + * (i.e. TEE_IOC_SUPPL_SEND) to submit a response. QTEE expects to receive the
>> + * response, including OB and OO in a specific order in the message; parameters
>> + * submitted with qcomtee_user_object_submit() should maintain this order.
>> + */
>> +
>> +/**
>> + * struct qcomtee_user_object - User object.
>> + * @object: &struct qcomtee_object representing this user object.
>> + * @ctx: context for which the user object is defined.
>> + * @object_id: object ID in @ctx.
>> + * @nor: notify on release.
>> + *
>> + * Any object managed in userspace is represented by this struct.
>> + * If @nor is set, a notification message is sent back to userspace
>> + * upon release.
>> + */
>> +struct qcomtee_user_object {
>> +       struct qcomtee_object object;
>> +       struct tee_context *ctx;
>> +       u64 object_id;
>> +       bool nor;
>> +};
>> +
>> +#define to_qcomtee_user_object(o) \
>> +       container_of((o), struct qcomtee_user_object, object)
>> +
>> +static struct qcomtee_object_operations qcomtee_user_object_ops;
>> +
>> +/* Is it a user object? */
>> +int is_qcomtee_user_object(struct qcomtee_object *object)
>> +{
>> +       return object != NULL_QCOMTEE_OBJECT &&
>> +              typeof_qcomtee_object(object) == QCOMTEE_OBJECT_TYPE_CB &&
>> +              object->ops == &qcomtee_user_object_ops;
>> +}
>> +
>> +/* Set the user object's 'notify on release' flag. */
>> +void qcomtee_user_object_set_notify(struct qcomtee_object *object, bool notify)
>> +{
>> +       if (is_qcomtee_user_object(object))
>> +               to_qcomtee_user_object(object)->nor = notify;
>> +}
>> +
>> +/* Supplicant Requests: */
>> +
>> +/**
>> + * enum qcomtee_req_state - Current state of request.
>> + * @QCOMTEE_REQ_QUEUED: Request is waiting for supplicant.
>> + * @QCOMTEE_REQ_PROCESSING: Request has been picked by the supplicant.
>> + * @QCOMTEE_REQ_PROCESSED: Response has been submitted for the request.
>> + */
>> +enum qcomtee_req_state {
>> +       QCOMTEE_REQ_QUEUED = 1,
>> +       QCOMTEE_REQ_PROCESSING,
>> +       QCOMTEE_REQ_PROCESSED,
>> +};
>> +
>> +/* User requests sent to supplicants. */
>> +struct qcomtee_ureq {
>> +       enum qcomtee_req_state state;
>> +
>> +       /* User Request: */
>> +       int req_id;
>> +       u64 object_id;
>> +       u32 op;
>> +       struct qcomtee_arg *args;
>> +       int errno;
>> +
>> +       struct list_head node;
>> +       struct completion c; /* Completion for whoever wait. */
>> +};
>> +
>> +/*
>> + * Placeholder for a PROCESSING request in qcomtee_context.reqs_idr.
>> + *
>> + * If the thread that calls qcomtee_object_invoke() dies and the supplicant
>> + * is processing the request, we replace the entry in qcomtee_context.reqs_idr
>> + * with empty_ureq. This ensures that (1) the req_id remains busy and is not
>> + * reused, and (2) the supplicant fails to submit the response and performs
>> + * the necessary rollback.
>> + */
>> +static struct qcomtee_ureq empty_ureq = { .state = QCOMTEE_REQ_PROCESSING };
>> +
>> +/* Enqueue a user request for a context and assign a request ID. */
>> +static int ureq_enqueue(struct qcomtee_context_data *ctxdata,
>> +                       struct qcomtee_ureq *ureq)
>> +{
>> +       int ret;
>> +
>> +       guard(mutex)(&ctxdata->reqs_lock);
>> +       /* Supplicant is dying. */
>> +       if (ctxdata->released)
>> +               return -ENODEV;
>> +
>> +       /* Allocate an ID and queue the request. */
>> +       ret = idr_alloc(&ctxdata->reqs_idr, ureq, 0, 0, GFP_KERNEL);
>> +       if (ret < 0)
>> +               return ret;
>> +
>> +       ureq->req_id = ret;
>> +       ureq->state = QCOMTEE_REQ_QUEUED;
>> +       list_add_tail(&ureq->node, &ctxdata->reqs_list);
>> +
>> +       return 0;
>> +}
>> +
>> +/**
>> + * ureq_dequeue() - Dequeue a user request from a context.
>> + * @ctxdata: context data for a context to dequeue the request.
>> + * @req_id: ID of the request to be dequeued.
>> + *
>> + * It dequeues a user request and releases its request ID.
>> + *
>> + * Context: The caller should hold &qcomtee_context_data->reqs_lock.
>> + * Return: Returns the user request associated with this ID; otherwise, NULL.
>> + */
>> +static struct qcomtee_ureq *ureq_dequeue(struct qcomtee_context_data *ctxdata,
>> +                                        int req_id)
>> +{
>> +       struct qcomtee_ureq *ureq;
>> +
>> +       ureq = idr_remove(&ctxdata->reqs_idr, req_id);
>> +       if (ureq == &empty_ureq || !ureq)
>> +               return NULL;
>> +
>> +       list_del(&ureq->node);
>> +
>> +       return ureq;
>> +}
>> +
>> +/**
>> + * ureq_replace() - Replace a user request.
>> + * @ctxdata: context data for a context to replace the request.
>> + * @ureq: request to be replaced.
>> + * @ureq_new: request to replace it with.
>> + *
>> + * Context: The caller should hold &qcomtee_context_data->reqs_lock.
>> + */
>> +static void ureq_replace(struct qcomtee_context_data *ctxdata,
>> +                        struct qcomtee_ureq *ureq,
>> +                        struct qcomtee_ureq *ureq_new)
>> +{
>> +       idr_replace(&ctxdata->reqs_idr, ureq_new, ureq->req_id);
>> +       /* ureq does not have a valid ID anymore; remove it from the queue. */
>> +       list_del(&ureq->node);
>> +}
>> +
>> +/**
>> + * ureq_select() - Select the next request in a context.
>> + * @ctxdata: context data for a context to pop a request.
>> + * @ubuf_size: size of the available buffer for UBUF parameters.
>> + * @num_params: number of entries for the TEE parameter array.
>> + *
>> + * It checks if @num_params is large enough to fit the next request arguments.
>> + * It checks if @ubuf_size is large enough to fit IB buffer arguments.
>> + *
>> + * Context: The caller should hold &qcomtee_context_data->reqs_lock.
>> + * Return: On success, returns a request;
>> + *         on failure, returns NULL and ERR_PTR.
>> + */
>> +static struct qcomtee_ureq *ureq_select(struct qcomtee_context_data *ctxdata,
>> +                                       size_t ubuf_size, int num_params)
>> +{
>> +       struct qcomtee_ureq *req, *ureq = NULL;
>> +       struct qcomtee_arg *u;
>> +       int i;
>> +
>> +       /* Find the a queued request. */
>> +       list_for_each_entry(req, &ctxdata->reqs_list, node) {
>> +               if (req->state == QCOMTEE_REQ_QUEUED) {
>> +                       ureq = req;
>> +                       break;
>> +               }
>> +       }
>> +
>> +       if (!ureq)
>> +               return NULL;
>> +
>> +       u = ureq->args;
>> +       /* (1) Is there enough TEE parameters? */
>> +       if (num_params < qcomtee_args_len(u))
>> +               return ERR_PTR(-EINVAL);
>> +       /* (2) Is there enough space to pass input buffers? */
>> +       qcomtee_arg_for_each_input_buffer(i, u) {
>> +               ubuf_size = size_sub(ubuf_size, u[i].b.size);
>> +               if (ubuf_size == SIZE_MAX)
>> +                       return ERR_PTR(-EINVAL);
>> +
>> +               ubuf_size = round_down(ubuf_size, 8);
>> +       }
>> +
>> +       return ureq;
>> +}
>> +
>> +/* This is called when there are no more users for the ctxdata. */
>> +void qcomtee_requests_destroy(struct qcomtee_context_data *ctxdata)
>> +{
>> +       struct qcomtee_ureq *req, *ureq;
>> +
>> +       guard(mutex)(&ctxdata->reqs_lock);
>> +       /* So ureq_enqueue() refuses new requests from QTEE. */
>> +       ctxdata->released = 1;
> 
> Magic number?
> 
>> +
>> +       list_for_each_entry_safe(ureq, req, &ctxdata->reqs_list, node) {
>> +               ureq_dequeue(ctxdata, ureq->req_id);
>> +
>> +               /*
>> +                * Terminate requests.
>> +                * Depending on who enqueues the ureq, there may be someone
>> +                * waiting for the response or not:
>> +                */
>> +               if (ureq->op != QCOMTEE_MSG_OBJECT_OP_RELEASE) {
>> +                       /* (1) enqueued by qcomtee_user_object_dispatch(). */
>> +                       ureq->state = QCOMTEE_REQ_PROCESSED;
>> +                       ureq->errno = -ENODEV;
>> +
>> +                       complete(&ureq->c);
>> +               } else {
>> +                       /* (2) enqueued by qcomtee_user_object_release(). */
>> +                       kfree(ureq);
>> +               }
>> +       }
>> +}
>> +
>> +/* User Object API. */
>> +
>> +/* User object dispatcher. */
>> +static int qcomtee_user_object_dispatch(struct qcomtee_object_invoke_ctx *oic,
>> +                                       struct qcomtee_object *object, u32 op,
>> +                                       struct qcomtee_arg *args)
>> +{
>> +       struct qcomtee_user_object *uo = to_qcomtee_user_object(object);
>> +       struct qcomtee_context_data *ctxdata = uo->ctx->data;
>> +       struct qcomtee_ureq *ureq __free(kfree) = NULL;
>> +       int errno;
>> +
>> +       ureq = kzalloc(sizeof(*ureq), GFP_KERNEL);
>> +       if (!ureq)
>> +               return -ENOMEM;
>> +
>> +       init_completion(&ureq->c);
>> +       ureq->object_id = uo->object_id;
>> +       ureq->op = op;
>> +       ureq->args = args;
>> +
>> +       /* Queue the request. */
>> +       if (ureq_enqueue(ctxdata, ureq))
>> +               return -ENODEV;
>> +
>> +       /* Wakeup supplicant to process it. */
>> +       complete(&ctxdata->req_c);
>> +
>> +       /*
>> +        * Wait for the supplicant to process the request.
>> +        *
>> +        * The supplicant is expected to process the request in a timely manner.
>> +        * We wait as KILLABLE in case the supplicant and invoke thread are
>> +        * both running from the same user process; otherwise, the process
>> +        * will be stuck on a fatal signal.
>> +        */
>> +       if (!wait_for_completion_state(&ureq->c,
>> +                                      TASK_KILLABLE | TASK_FREEZABLE)) {
>> +               errno = ureq->errno;
>> +               /* On success, notify() frees the request. */
>> +               if (!errno)
>> +                       oic->data = no_free_ptr(ureq);
>> +       } else {
>> +               enum qcomtee_req_state prev_state;
>> +
>> +               errno = -ENODEV;
>> +
>> +               scoped_guard(mutex, &ctxdata->reqs_lock) {
>> +                       prev_state = ureq->state;
>> +
>> +                       /* Replace with empty_ureq to keep req_id reserved. */
>> +                       if (prev_state == QCOMTEE_REQ_PROCESSING)
>> +                               ureq_replace(ctxdata, ureq, &empty_ureq);
>> +
>> +                       /* Remove as supplicant has never seen this request. */
>> +                       else if (prev_state == QCOMTEE_REQ_QUEUED)
>> +                               ureq_dequeue(ctxdata, ureq->req_id);
>> +               }
>> +
>> +               /* Supplicant did some work, we should not discard it. */
>> +               if (prev_state == QCOMTEE_REQ_PROCESSED) {
>> +                       errno = ureq->errno;
>> +                       /* On success, notify() frees the request. */
>> +                       if (!errno)
>> +                               oic->data = no_free_ptr(ureq);
>> +               }
>> +       }
>> +
>> +       return errno;
>> +}
>> +
>> +/* This is called after submitting the dispatcher response. */
>> +static void qcomtee_user_object_notify(struct qcomtee_object_invoke_ctx *oic,
>> +                                      struct qcomtee_object *unused_object,
>> +                                      int err)
>> +{
>> +       struct qcomtee_ureq *ureq = oic->data;
>> +       struct qcomtee_arg *u = ureq->args;
>> +       int i;
>> +
>> +       qcomtee_arg_for_each_output_object(i, u) {
>> +               /*
>> +                * If err, there was a transport issue, and QTEE did not
>> +                * receive the response for the dispatcher. Release the callback
>> +                * object created for QTEE, in addition to the copies of
>> +                * objects kept for the drivers.
>> +                */
>> +               if (err &&
>> +                   (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB))
>> +                       qcomtee_object_put(u[i].o);
>> +               qcomtee_object_put(u[i].o);
>> +       }
>> +
>> +       kfree(ureq);
>> +}
>> +
>> +static void qcomtee_user_object_release(struct qcomtee_object *object)
>> +{
>> +       struct qcomtee_user_object *uo = to_qcomtee_user_object(object);
>> +       struct qcomtee_context_data *ctxdata = uo->ctx->data;
>> +       struct qcomtee_ureq *ureq;
>> +
>> +       /* RELEASE does not require any argument. */
>> +       static struct qcomtee_arg args[] = { { .type = QCOMTEE_ARG_TYPE_INV } };
>> +
>> +       if (!uo->nor)
>> +               goto out_no_notify;
>> +
>> +       ureq = kzalloc(sizeof(*ureq), GFP_KERNEL);
>> +       if (!ureq)
>> +               goto out_no_notify;
>> +
>> +       /* QUEUE a release request: */
>> +       ureq->object_id = uo->object_id;
>> +       ureq->op = QCOMTEE_MSG_OBJECT_OP_RELEASE;
>> +       ureq->args = args;
>> +       if (ureq_enqueue(ctxdata, ureq)) {
>> +               kfree(ureq);
>> +               /* Ignore the notification if it cannot be queued. */
>> +               goto out_no_notify;
>> +       }
>> +
>> +       complete(&ctxdata->req_c);
>> +
>> +out_no_notify:
>> +       teedev_ctx_put(uo->ctx);
>> +       kfree(uo);
>> +}
>> +
>> +static struct qcomtee_object_operations qcomtee_user_object_ops = {
>> +       .release = qcomtee_user_object_release,
>> +       .notify = qcomtee_user_object_notify,
>> +       .dispatch = qcomtee_user_object_dispatch,
>> +};
>> +
>> +/**
>> + * qcomtee_user_param_to_object() - OBJREF parameter to &struct qcomtee_object.
>> + * @object: object returned.
>> + * @param: TEE parameter.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * @param is an OBJREF with %QCOMTEE_OBJREF_FLAG_USER flags.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_user_param_to_object(struct qcomtee_object **object,
>> +                                struct tee_param *param,
>> +                                struct tee_context *ctx)
>> +{
>> +       struct qcomtee_user_object *user_object __free(kfree) = NULL;
>> +       int err;
>> +
>> +       user_object = kzalloc(sizeof(*user_object), GFP_KERNEL);
>> +       if (!user_object)
>> +               return -ENOMEM;
>> +
>> +       user_object->ctx = ctx;
>> +       user_object->object_id = param->u.objref.id;
>> +       /* By default, always notify userspace upon release. */
>> +       user_object->nor = true;
>> +       err = qcomtee_object_user_init(&user_object->object,
>> +                                      QCOMTEE_OBJECT_TYPE_CB,
>> +                                      &qcomtee_user_object_ops, "uo-%lu",
>> +                                      param->u.objref.id);
>> +       if (err)
>> +               return err;
>> +
>> +       teedev_ctx_get(ctx);
>> +
>> +       *object = &no_free_ptr(user_object)->object;
>> +
>> +       return 0;
>> +}
>> +
>> +/* Reverse what qcomtee_user_param_to_object() does. */
>> +int qcomtee_user_param_from_object(struct tee_param *param,
>> +                                  struct qcomtee_object *object,
>> +                                  struct tee_context *ctx)
>> +{
>> +       struct qcomtee_user_object *uo;
>> +
>> +       uo = to_qcomtee_user_object(object);
>> +       /* Ensure the object is in the same context as the caller. */
>> +       if (uo->ctx != ctx)
>> +               return -EINVAL;
>> +
>> +       param->u.objref.id = uo->object_id;
>> +       param->u.objref.flags = QCOMTEE_OBJREF_FLAG_USER;
>> +
>> +       /* User objects are valid in userspace; do not keep a copy. */
>> +       qcomtee_object_put(object);
>> +
>> +       return 0;
>> +}
>> +
>> +/**
>> + * qcomtee_cb_params_from_args() - Convert QTEE arguments to TEE parameters.
>> + * @params: TEE parameters.
>> + * @u: QTEE arguments.
>> + * @num_params: number of elements in the parameter array.
>> + * @ubuf_addr: user buffer for arguments of type %QCOMTEE_ARG_TYPE_IB.
>> + * @ubuf_size: size of the user buffer.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * It expects @params to have enough entries for @u. Entries in @params are of
>> + * %TEE_IOCTL_PARAM_ATTR_TYPE_NONE.
>> + *
>> + * Return: On success, returns the number of input parameters;
>> + *         on failure, returns < 0.
>> + */
>> +static int qcomtee_cb_params_from_args(struct tee_param *params,
>> +                                      struct qcomtee_arg *u, int num_params,
>> +                                      void __user *ubuf_addr, size_t ubuf_size,
>> +                                      struct tee_context *ctx)
>> +{
>> +       int i, np;
>> +       void __user *uaddr;
>> +
>> +       qcomtee_arg_for_each(i, u) {
>> +               switch (u[i].type) {
>> +               case QCOMTEE_ARG_TYPE_IB:
>> +                       params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT;
>> +
>> +                       /* Underflow already checked in ureq_select(). */
>> +                       ubuf_size = round_down(ubuf_size - u[i].b.size, 8);
>> +                       uaddr = (void *__user)(ubuf_addr + ubuf_size);
>> +
>> +                       params[i].u.ubuf.uaddr = uaddr;
>> +                       params[i].u.ubuf.size = u[i].b.size;
>> +                       if (copy_to_user(params[i].u.ubuf.uaddr, u[i].b.addr,
>> +                                        u[i].b.size))
>> +                               goto out_failed;
>> +
>> +                       break;
>> +               case QCOMTEE_ARG_TYPE_OB:
>> +                       params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT;
>> +                       /* Let the user knows the maximum size we expect. */
>> +                       params[i].u.ubuf.size = u[i].b.size;
>> +
>> +                       break;
>> +               case QCOMTEE_ARG_TYPE_IO:
>> +                       params[i].attr = TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT;
>> +                       if (qcomtee_objref_from_arg(&params[i], &u[i], ctx))
>> +                               goto out_failed;
>> +
>> +                       break;
>> +               case QCOMTEE_ARG_TYPE_OO:
>> +                       params[i].attr =
>> +                               TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT;
>> +
>> +                       break;
>> +               default: /* Never get here! */
>> +                       goto out_failed;
>> +               }
>> +       }
>> +
>> +       return i;
>> +
>> +out_failed:
>> +       /* Undo qcomtee_objref_from_arg(). */
>> +       for (np = i; np >= 0; np--) {
>> +               if (params[np].attr == TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT)
>> +                       qcomtee_context_del_qtee_object(&params[np], ctx);
>> +       }
>> +
>> +       /* Release any IO objects not processed. */
>> +       for (; u[i].type; i++) {
>> +               if (u[i].type == QCOMTEE_ARG_TYPE_IO)
>> +                       qcomtee_object_put(u[i].o);
>> +       }
>> +
>> +       return -EINVAL;
>> +}
>> +
>> +/**
>> + * qcomtee_cb_params_to_args() - Convert TEE parameters to QTEE arguments.
>> + * @u: QTEE arguments.
>> + * @params: TEE parameters.
>> + * @num_params: number of elements in the parameter array.
>> + * @ctx: context in which the conversion should happen.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +static int qcomtee_cb_params_to_args(struct qcomtee_arg *u,
>> +                                    struct tee_param *params, int num_params,
>> +                                    struct tee_context *ctx)
>> +{
>> +       int i;
>> +
>> +       qcomtee_arg_for_each(i, u) {
>> +               switch (u[i].type) {
>> +               case QCOMTEE_ARG_TYPE_IB:
>> +                       if (params[i].attr !=
>> +                           TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT)
>> +                               goto out_failed;
>> +
>> +                       break;
>> +               case QCOMTEE_ARG_TYPE_OB:
>> +                       if (params[i].attr !=
>> +                           TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT)
>> +                               goto out_failed;
>> +
>> +                       /* Client can not send more data than requested. */
>> +                       if (params[i].u.ubuf.size > u[i].b.size)
>> +                               goto out_failed;
>> +
>> +                       if (copy_from_user(u[i].b.addr, params[i].u.ubuf.uaddr,
>> +                                          params[i].u.ubuf.size))
>> +                               goto out_failed;
>> +
>> +                       u[i].b.size = params[i].u.ubuf.size;
>> +
>> +                       break;
>> +               case QCOMTEE_ARG_TYPE_IO:
>> +                       if (params[i].attr !=
>> +                           TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT)
>> +                               goto out_failed;
>> +
>> +                       break;
>> +               case QCOMTEE_ARG_TYPE_OO:
>> +                       if (params[i].attr !=
>> +                           TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT)
>> +                               goto out_failed;
>> +
>> +                       if (qcomtee_objref_to_arg(&u[i], &params[i], ctx))
>> +                               goto out_failed;
>> +
>> +                       break;
>> +               default: /* Never get here! */
>> +                       goto out_failed;
>> +               }
>> +       }
>> +
>> +       return 0;
>> +
>> +out_failed:
>> +       /* Undo qcomtee_objref_to_arg(). */
>> +       for (i--; i >= 0; i--) {
>> +               if (u[i].type != QCOMTEE_ARG_TYPE_OO)
>> +                       continue;
>> +
>> +               qcomtee_user_object_set_notify(u[i].o, false);
>> +               if (typeof_qcomtee_object(u[i].o) == QCOMTEE_OBJECT_TYPE_CB)
>> +                       qcomtee_object_put(u[i].o);
>> +
>> +               qcomtee_object_put(u[i].o);
>> +       }
>> +
>> +       return -EINVAL;
>> +}
>> +
>> +/**
>> + * qcomtee_user_object_select() - Select a request for a user object.
>> + * @ctx: context to look for a user object.
>> + * @params: parameters for @op.
>> + * @num_params: number of elements in the parameter array.
>> + * @uaddr: user buffer for output UBUF parameters.
>> + * @size: size of user buffer @uaddr.
>> + * @data: information for the selected request.
>> + *
>> + * @params is filled along with @data for the selected request.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_user_object_select(struct tee_context *ctx,
>> +                              struct tee_param *params, int num_params,
>> +                              void __user *uaddr, size_t size,
>> +                              struct qcomtee_user_object_request_data *data)
>> +{
>> +       struct qcomtee_context_data *ctxdata = ctx->data;
>> +       struct qcomtee_ureq *ureq;
>> +       int ret;
>> +
>> +       while (1) {
>> +               scoped_guard(mutex, &ctxdata->reqs_lock) {
>> +                       ureq = ureq_select(ctxdata, size, num_params);
>> +                       if (!ureq)
>> +                               goto wait_for_request;
>> +
>> +                       if (IS_ERR(ureq))
>> +                               return PTR_ERR(ureq);
>> +
>> +                       /* Processing the request 'QUEUED -> PROCESSING'. */
>> +                       ureq->state = QCOMTEE_REQ_PROCESSING;
>> +
>> +                       /* ''Prepare user request:'' */
>> +                       data->id = ureq->req_id;
>> +                       data->object_id = ureq->object_id;
>> +                       data->op = ureq->op;
>> +                       ret = qcomtee_cb_params_from_args(params, ureq->args,
>> +                                                         num_params, uaddr,
>> +                                                         size, ctx);
>> +                       if (ret >= 0)
>> +                               goto done_request;
>> +
>> +                       /* Something is wrong with the request. */
>> +
>> +                       ureq_dequeue(ctxdata, data->id);
>> +                       /* Send error to QTEE. */
>> +                       ureq->state = QCOMTEE_REQ_PROCESSED;
>> +                       ureq->errno = ret;
>> +
>> +                       complete(&ureq->c);
>> +               }
>> +
>> +               continue;
>> +wait_for_request:
>> +               /* Wait for a new QUEUED request. */
>> +               if (wait_for_completion_interruptible(&ctxdata->req_c))
>> +                       return -ERESTARTSYS;
>> +       }
>> +
>> +done_request:
>> +       /* No one is waiting for the response. */
>> +       if (data->op == QCOMTEE_MSG_OBJECT_OP_RELEASE) {
>> +               scoped_guard(mutex, &ctxdata->reqs_lock)
>> +                       ureq_dequeue(ctxdata, data->id);
>> +               kfree(ureq);
>> +       }
>> +
>> +       data->np = ret;
>> +
>> +       return 0;
>> +}
>> +
>> +/**
>> + * qcomtee_user_object_submit() - Submit a response for a user object.
>> + * @ctx: context to look for a user object.
>> + * @params: returned parameters.
>> + * @num_params: number of elements in the parameter array.
>> + * @req_id: request ID for the response.
>> + * @errno: result of user object invocation.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_user_object_submit(struct tee_context *ctx,
>> +                              struct tee_param *params, int num_params,
>> +                              int req_id, int errno)
>> +{
>> +       struct qcomtee_context_data *ctxdata = ctx->data;
>> +       struct qcomtee_ureq *ureq;
>> +
>> +       guard(mutex)(&ctxdata->reqs_lock);
>> +
>> +       ureq = ureq_dequeue(ctxdata, req_id);
>> +       if (!ureq)
>> +               return -EINVAL;
>> +
>> +       ureq->state = QCOMTEE_REQ_PROCESSED;
>> +
>> +       if (!errno)
>> +               ureq->errno = qcomtee_cb_params_to_args(ureq->args, params,
>> +                                                       num_params, ctx);
>> +       else
>> +               ureq->errno = errno;
>> +
>> +       /* Return errno if qcomtee_cb_params_to_args() failed; otherwise 0. */
>> +       if (!errno && ureq->errno)
>> +               errno = ureq->errno;
>> +       else
>> +               errno = 0;
>> +
>> +       /* Send result to QTEE. */
>> +       complete(&ureq->c);
>> +
>> +       return errno;
>> +}
>> diff --git a/include/linux/firmware/qcom/qcom_tee.h b/include/linux/firmware/qcom/qcom_tee.h
>> new file mode 100644
>> index 000000000000..1d9f9bc320fe
>> --- /dev/null
>> +++ b/include/linux/firmware/qcom/qcom_tee.h
>> @@ -0,0 +1,302 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/* Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#ifndef __QCOM_TEE_H
>> +#define __QCOM_TEE_H
>> +
>> +#include <linux/completion.h>
>> +#include <linux/kref.h>
>> +#include <linux/slab.h>
>> +#include <linux/workqueue.h>
>> +
>> +struct qcomtee_object;
>> +
>> +/**
>> + * DOC: Overview
>> + *
>> + * qcomtee_object provides object refcounting, ID allocation for objects hosted
>> + * in the kernel, and necessary message marshaling for Qualcomm TEE (QTEE).
>> + *
>> + * To invoke an object in QTEE, the user calls qcomtee_object_do_invoke()
>> + * while passing an instance of &struct qcomtee_object and the requested
>> + * operation + arguments.
>> + *
>> + * After boot, QTEE provides a static object %ROOT_QCOMTEE_OBJECT (type of
>> + * %QCOMTEE_OBJECT_TYPE_ROOT). The root object is invoked to pass the user's
>> + * credentials and obtain other instances of &struct qcomtee_object (type of
>> + * %QCOMTEE_OBJECT_TYPE_TEE) that represent services and TAs in QTEE;
>> + * see &enum qcomtee_object_type.
>> + *
>> + * The objects received from QTEE are refcounted. So the owner of these objects
>> + * can issue qcomtee_object_get() to increase the refcount and pass objects
>> + * to other clients, or issue qcomtee_object_put() to decrease the refcount
>> + * and release the resources in QTEE.
>> + *
>> + * The kernel can host services accessible to QTEE. A driver should embed
>> + * an instance of &struct qcomtee_object in the struct it wants to export to
>> + * QTEE (this is called a callback object). It issues qcomtee_object_user_init()
>> + * to set the dispatch() operation for the callback object and set its type
>> + * to %QCOMTEE_OBJECT_TYPE_CB.
>> + *
>> + * core.c holds an object table for callback objects. An object ID is assigned
>> + * to each callback object, which is an index to the object table. QTEE uses
>> + * these IDs to reference or invoke callback objects.
>> + *
>> + * If QTEE invokes a callback object in the kernel, the dispatch() operation is
>> + * called in the context of the thread that originally called
>> + * qcomtee_object_do_invoke().
>> + */
>> +
>> +/**
>> + * enum qcomtee_object_type - Object types.
>> + * @QCOMTEE_OBJECT_TYPE_TEE: object hosted on QTEE.
>> + * @QCOMTEE_OBJECT_TYPE_CB: object hosted on kernel.
>> + * @QCOMTEE_OBJECT_TYPE_ROOT: 'primordial' object.
>> + * @QCOMTEE_OBJECT_TYPE_NULL: NULL object.
>> + *
>> + * The primordial object is used for bootstrapping the IPC connection between
>> + * the kernel and QTEE. It is invoked by the kernel when it wants to get a
>> + * 'client env'.
>> + */
>> +enum qcomtee_object_type {
>> +       QCOMTEE_OBJECT_TYPE_TEE,
>> +       QCOMTEE_OBJECT_TYPE_CB,
>> +       QCOMTEE_OBJECT_TYPE_ROOT,
>> +       QCOMTEE_OBJECT_TYPE_NULL,
>> +};
>> +
>> +/**
>> + * enum qcomtee_arg_type - Type of QTEE argument.
>> + * @QCOMTEE_ARG_TYPE_INV: invalid type.
>> + * @QCOMTEE_ARG_TYPE_OB: output buffer (OB).
>> + * @QCOMTEE_ARG_TYPE_OO: output object (OO).
>> + * @QCOMTEE_ARG_TYPE_IB: input buffer (IB).
>> + * @QCOMTEE_ARG_TYPE_IO: input object (IO).
>> + *
>> + * Use the invalid type to specify the end of the argument array.
>> + */
>> +enum qcomtee_arg_type {
>> +       QCOMTEE_ARG_TYPE_INV = 0,
>> +       QCOMTEE_ARG_TYPE_OB,
>> +       QCOMTEE_ARG_TYPE_OO,
>> +       QCOMTEE_ARG_TYPE_IB,
>> +       QCOMTEE_ARG_TYPE_IO,
>> +       QCOMTEE_ARG_TYPE_NR,
>> +};
>> +
>> +/**
>> + * define QCOMTEE_ARGS_PER_TYPE - Maximum arguments of a specific type.
>> + *
>> + * The QTEE transport protocol limits the maximum number of arguments of
>> + * a specific type (i.e., IB, OB, IO, and OO).
>> + */
>> +#define QCOMTEE_ARGS_PER_TYPE 16
>> +
>> +/* Maximum arguments that can fit in a QTEE message, ignoring the type. */
>> +#define QCOMTEE_ARGS_MAX (QCOMTEE_ARGS_PER_TYPE * (QCOMTEE_ARG_TYPE_NR - 1))
>> +
>> +struct qcomtee_buffer {
>> +       union {
>> +               void *addr;
>> +               void __user *uaddr;
>> +       };
>> +       size_t size;
>> +};
>> +
>> +/**
>> + * struct qcomtee_arg - Argument for QTEE object invocation.
>> + * @type: type of argument as &enum qcomtee_arg_type.
>> + * @flags: extra flags.
>> + * @b: address and size if the type of argument is a buffer.
>> + * @o: object instance if the type of argument is an object.
>> + *
>> + * &qcomtee_arg.flags only accepts %QCOMTEE_ARG_FLAGS_UADDR for now, which
>> + * states that &qcomtee_arg.b contains a userspace address in uaddr.
>> + */
>> +struct qcomtee_arg {
>> +       enum qcomtee_arg_type type;
>> +/* 'b.uaddr' holds a __user address. */
>> +#define QCOMTEE_ARG_FLAGS_UADDR BIT(0)
>> +       unsigned int flags;
>> +       union {
>> +               struct qcomtee_buffer b;
>> +               struct qcomtee_object *o;
>> +       };
>> +};
>> +
>> +static inline int qcomtee_args_len(struct qcomtee_arg *args)
>> +{
>> +       int i = 0;
>> +
>> +       while (args[i].type != QCOMTEE_ARG_TYPE_INV)
>> +               i++;
>> +       return i;
>> +}
>> +
>> +/* Context is busy (callback is in progress). */
>> +#define QCOMTEE_OIC_FLAG_BUSY BIT(1)
>> +/* Context needs to notify the current object. */
>> +#define QCOMTEE_OIC_FLAG_NOTIFY BIT(2)
>> +/* Context has shared state with QTEE. */
>> +#define QCOMTEE_OIC_FLAG_SHARED BIT(3)
>> +
>> +struct qcomtee_object_invoke_ctx {
>> +       /* TEE context for this invocation. */
>> +       struct tee_context *ctx;
>> +       unsigned long flags;
>> +       int errno;
>> +
>> +       /* Current object invoked in this callback context. */
>> +       struct qcomtee_object *object;
>> +
>> +       /* Dispatcher argument array (+1 for ending QCOMTEE_ARG_TYPE_INV). */
>> +       struct qcomtee_arg u[QCOMTEE_ARGS_MAX + 1];
>> +
>> +       /* Inbound and Outbound buffers shared with QTEE. */
>> +       struct qcomtee_buffer in_msg; /* Inbound buffer.  */
>> +       struct qcomtee_buffer out_msg; /* Outbound buffer. */
>> +       struct tee_shm *in_shm; /* TEE shm allocated for inbound buffer. */
>> +       struct tee_shm *out_shm; /* TEE shm allocated for outbound buffer. */
>> +
>> +       /* Extra data attached to this context. */
>> +       void *data;
>> +};
>> +
>> +static inline struct qcomtee_object_invoke_ctx *
>> +qcomtee_object_invoke_ctx_alloc(struct tee_context *ctx)
>> +{
>> +       struct qcomtee_object_invoke_ctx *oic;
>> +
>> +       oic = kzalloc(sizeof(*oic), GFP_KERNEL);
>> +       if (oic)
>> +               oic->ctx = ctx;
>> +       return oic;
>> +}
>> +
>> +/**
>> + * qcomtee_object_do_invoke() - Submit an invocation for an object.
>> + * @oic: context to use for the current invocation.
>> + * @object: object being invoked.
>> + * @op: requested operation on the object.
>> + * @u: array of arguments for the current invocation.
>> + * @result: result returned from QTEE.
>> + *
>> + * The caller is responsible for keeping track of the refcount for each object,
>> + * including @object. On return, the caller loses ownership of all input
>> + * objects of type %QCOMTEE_OBJECT_TYPE_CB.
>> + *
>> + * @object can be of %QCOMTEE_OBJECT_TYPE_ROOT or %QCOMTEE_OBJECT_TYPE_TEE.
>> + *
>> + * Return: On success, returns 0. On error, returns -EAGAIN if invocation
>> + * failed and the user may retry the invocation, -ENODEV on fatal failure.
>> + */
>> +int qcomtee_object_do_invoke(struct qcomtee_object_invoke_ctx *oic,
>> +                            struct qcomtee_object *object, u32 op,
>> +                            struct qcomtee_arg *u, int *result);
>> +
>> +/**
>> + * struct qcomtee_object_operations - Callback object operations.
>> + * @release: release the object if QTEE is not using it.
>> + * @dispatch: dispatch the operation requested by QTEE.
>> + * @notify: report the status of any pending response submitted by @dispatch.
>> + */
>> +struct qcomtee_object_operations {
>> +       void (*release)(struct qcomtee_object *object);
>> +       int (*dispatch)(struct qcomtee_object_invoke_ctx *oic,
>> +                       struct qcomtee_object *object, u32 op,
>> +                       struct qcomtee_arg *args);
>> +       void (*notify)(struct qcomtee_object_invoke_ctx *oic,
>> +                      struct qcomtee_object *object, int err);
>> +};
>> +
>> +/**
>> + * struct qcomtee_object - QTEE or kernel object.
>> + * @name: object name.
>> + * @refcount: reference counter.
>> + * @object_type: object type as &enum qcomtee_object_type.
>> + * @info: extra information for the object.
>> + * @ops: callback operations for objects of type %QCOMTEE_OBJECT_TYPE_CB.
>> + * @work: work for async operations on the object.
>> + *
>> + * @work is used for releasing objects of %QCOMTEE_OBJECT_TYPE_TEE type.
>> + */
>> +struct qcomtee_object {
>> +       const char *name;
>> +       struct kref refcount;
>> +
>> +       enum qcomtee_object_type object_type;
>> +       struct object_info {
>> +               unsigned long qtee_id;
>> +               /* TEE context for QTEE object async requests. */
>> +               struct tee_context *qcomtee_async_ctx;
>> +       } info;
>> +
>> +       struct qcomtee_object_operations *ops;
>> +       struct work_struct work;
>> +};
>> +
>> +/* Static instances of qcomtee_object objects. */
>> +#define NULL_QCOMTEE_OBJECT ((struct qcomtee_object *)(0))
>> +extern struct qcomtee_object qcomtee_object_root;
>> +#define ROOT_QCOMTEE_OBJECT (&qcomtee_object_root)
>> +
>> +static inline enum qcomtee_object_type
>> +typeof_qcomtee_object(struct qcomtee_object *object)
>> +{
>> +       if (object == NULL_QCOMTEE_OBJECT)
>> +               return QCOMTEE_OBJECT_TYPE_NULL;
>> +       return object->object_type;
>> +}
>> +
>> +static inline const char *qcomtee_object_name(struct qcomtee_object *object)
>> +{
>> +       if (object == NULL_QCOMTEE_OBJECT)
>> +               return "null";
>> +
>> +       if (!object->name)
>> +               return "no-name";
>> +       return object->name;
>> +}
>> +
>> +/**
>> + * qcomtee_object_user_init() - Initialize an object for the user.
>> + * @object: object to initialize.
>> + * @ot: type of object as &enum qcomtee_object_type.
>> + * @ops: instance of callbacks.
>> + * @fmt: name assigned to the object.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcomtee_object_user_init(struct qcomtee_object *object,
>> +                            enum qcomtee_object_type ot,
>> +                            struct qcomtee_object_operations *ops,
>> +                            const char *fmt, ...);
>> +
>> +/* Object release is RCU protected. */
>> +int qcomtee_object_get(struct qcomtee_object *object);
>> +void qcomtee_object_put(struct qcomtee_object *object);
>> +
>> +#define qcomtee_arg_for_each(i, args) \
>> +       for (i = 0; args[i].type != QCOMTEE_ARG_TYPE_INV; i++)
>> +
>> +/* Next argument of type @type after index @i. */
>> +int qcomtee_next_arg_type(struct qcomtee_arg *u, int i,
>> +                         enum qcomtee_arg_type type);
>> +
>> +/* Iterate over argument of given type. */
>> +#define qcomtee_arg_for_each_type(i, args, at)              \
>> +       for (i = 0, i = qcomtee_next_arg_type(args, i, at); \
> 
> i = qcomtee_next_arg_type(args, 0, at)

Ops. HOw I missed it. I'll update.

> 
>> +            args[i].type != QCOMTEE_ARG_TYPE_INV;          \
>> +            i++, i = qcomtee_next_arg_type(args, i, at))
> 
> i = qcomtee_next_arg_type(args, i + 1, at)
> 

Thank you so much Jens for the review.

Best regards,
Amir

> Cheers,
> Jens
> 
>> +
>> +#define qcomtee_arg_for_each_input_buffer(i, args) \
>> +       qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_IB)
>> +#define qcomtee_arg_for_each_output_buffer(i, args) \
>> +       qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_OB)
>> +#define qcomtee_arg_for_each_input_object(i, args) \
>> +       qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_IO)
>> +#define qcomtee_arg_for_each_output_object(i, args) \
>> +       qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_OO)
>> +
>> +#endif /* __QCOM_TEE_H */
>> diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
>> index 8642ce7e4772..0efb2835d6dc 100644
>> --- a/include/uapi/linux/tee.h
>> +++ b/include/uapi/linux/tee.h
>> @@ -59,6 +59,7 @@
>>  #define TEE_IMPL_ID_OPTEE      1
>>  #define TEE_IMPL_ID_AMDTEE     2
>>  #define TEE_IMPL_ID_TSTEE      3
>> +#define TEE_IMPL_ID_QTEE       4
>>
>>  /*
>>   * OP-TEE specific capabilities
>>
>> --
>> 2.34.1
>>

Re: [PATCH v3 08/11] tee: add Qualcomm TEE driver
Posted by kernel test robot 8 months, 3 weeks ago
Hi Amirreza,

kernel test robot noticed the following build warnings:

[auto build test WARNING on db8da9da41bced445077925f8a886c776a47440c]

url:    https://github.com/intel-lab-lkp/linux/commits/Amirreza-Zarrabi/tee-allow-a-driver-to-allocate-a-tee_device-without-a-pool/20250328-104950
base:   db8da9da41bced445077925f8a886c776a47440c
patch link:    https://lore.kernel.org/r/20250327-qcom-tee-using-tee-ss-without-mem-obj-v3-8-7f457073282d%40oss.qualcomm.com
patch subject: [PATCH v3 08/11] tee: add Qualcomm TEE driver
config: s390-allyesconfig (https://download.01.org/0day-ci/archive/20250329/202503290620.2KJEcZM6-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250329/202503290620.2KJEcZM6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503290620.2KJEcZM6-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/tee/qcomtee/core.c:310: warning: Function parameter or struct member 'oic' not described in 'qcomtee_object_qtee_init'


vim +310 drivers/tee/qcomtee/core.c

   298	
   299	/**
   300	 * qcomtee_object_qtee_init() - Initialize an object for QTEE.
   301	 * @object: object returned.
   302	 * @object_id: object ID received from QTEE.
   303	 *
   304	 * Return: On failure, returns < 0 and sets @object to %NULL_QCOMTEE_OBJECT.
   305	 *         On success, returns 0
   306	 */
   307	static int qcomtee_object_qtee_init(struct qcomtee_object_invoke_ctx *oic,
   308					    struct qcomtee_object **object,
   309					    unsigned int object_id)
 > 310	{
   311		int ret = 0;
   312	
   313		switch (qcomtee_object_type(object_id)) {
   314		case QCOMTEE_OBJECT_TYPE_NULL:
   315			*object = NULL_QCOMTEE_OBJECT;
   316	
   317			break;
   318		case QCOMTEE_OBJECT_TYPE_CB:
   319			*object = qcomtee_local_object_get(object_id);
   320			if (*object == NULL_QCOMTEE_OBJECT)
   321				ret = -EINVAL;
   322	
   323			break;
   324	
   325		default: /* QCOMTEE_OBJECT_TYPE_TEE */
   326			*object = qcomtee_qtee_object_alloc(oic, object_id);
   327			if (*object == NULL_QCOMTEE_OBJECT)
   328				ret = -ENOMEM;
   329	
   330			break;
   331		}
   332	
   333		return ret;
   334	}
   335	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki