[PATCH v2 3/3] scsi: ufs: core: Add OP-TEE based RPMB driver for UFS devices

Bean Huo posted 3 patches 15 hours ago
[PATCH v2 3/3] scsi: ufs: core: Add OP-TEE based RPMB driver for UFS devices
Posted by Bean Huo 15 hours ago
From: Bean Huo <beanhuo@micron.com>

This patch adds OP-TEE based RPMB support for UFS devices. This enables secure RPMB operations on
UFS devices through OP-TEE, providing the same functionality available for eMMC devices and
extending kernel-based secure storage support to UFS-based systems.

Benefits of OP-TEE based RPMB implementation:
- Eliminates dependency on userspace supplicant for RPMB access
- Enables early boot secure storage access (e.g., fTPM, secure UEFI variables)
- Provides kernel-level RPMB access as soon as UFS driver is initialized
- Removes complex initramfs dependencies and boot ordering requirements
- Ensures reliable and deterministic secure storage operations
- Supports both built-in and modular fTPM configurations

Co-developed-by: Can Guo <can.guo@oss.qualcomm.com>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
Signed-off-by: Bean Huo <beanhuo@micron.com>
---
 drivers/misc/Kconfig           |   2 +-
 drivers/ufs/core/Makefile      |   1 +
 drivers/ufs/core/ufs-rpmb.c    | 253 +++++++++++++++++++++++++++++++++
 drivers/ufs/core/ufshcd-priv.h |  13 ++
 drivers/ufs/core/ufshcd.c      |  30 +++-
 include/ufs/ufs.h              |   4 +
 include/ufs/ufshcd.h           |   3 +
 7 files changed, 301 insertions(+), 5 deletions(-)
 create mode 100644 drivers/ufs/core/ufs-rpmb.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index b9ca56930003..46ffa62eac6e 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -106,7 +106,7 @@ config PHANTOM
 
 config RPMB
 	tristate "RPMB partition interface"
-	depends on MMC
+	depends on MMC || SCSI_UFSHCD
 	help
 	  Unified RPMB unit interface for RPMB capable devices such as eMMC and
 	  UFS. Provides interface for in-kernel security controllers to access
diff --git a/drivers/ufs/core/Makefile b/drivers/ufs/core/Makefile
index cf820fa09a04..51e1867e524e 100644
--- a/drivers/ufs/core/Makefile
+++ b/drivers/ufs/core/Makefile
@@ -2,6 +2,7 @@
 
 obj-$(CONFIG_SCSI_UFSHCD)		+= ufshcd-core.o
 ufshcd-core-y				+= ufshcd.o ufs-sysfs.o ufs-mcq.o
+ufshcd-core-$(CONFIG_RPMB)		+= ufs-rpmb.o
 ufshcd-core-$(CONFIG_DEBUG_FS)		+= ufs-debugfs.o
 ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
 ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO)	+= ufshcd-crypto.o
diff --git a/drivers/ufs/core/ufs-rpmb.c b/drivers/ufs/core/ufs-rpmb.c
new file mode 100644
index 000000000000..84cdcf8efeb3
--- /dev/null
+++ b/drivers/ufs/core/ufs-rpmb.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * UFS OP-TEE based RPMB Driver
+ *
+ * Copyright (C) 2025 Micron Technology, Inc.
+ * Copyright (C) 2025 Qualcomm Technologies, Inc.
+ *
+ * Authors:
+ *	Bean Huo <beanhuo@micron.com>
+ *	Can Guo <can.guo@oss.qualcomm.com>
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/rpmb.h>
+#include <linux/string.h>
+#include <linux/list.h>
+#include <ufs/ufshcd.h>
+#include <linux/unaligned.h>
+#include "ufshcd-priv.h"
+
+#define UFS_RPMB_SEC_PROTOCOL		0xEC	/* JEDEC UFS application */
+#define UFS_RPMB_SEC_PROTOCOL_ID	0x01	/* JEDEC UFS RPMB protocol ID, CDB byte3 */
+
+static const struct bus_type ufs_rpmb_bus_type = {
+	.name = "ufs_rpmb",
+};
+
+/* UFS RPMB device structure */
+struct ufs_rpmb_dev {
+	u8 region_id;
+	struct device dev;
+	struct rpmb_dev *rdev;
+	struct ufs_hba *hba;
+	struct list_head node;
+};
+
+static int ufs_sec_submit(struct ufs_hba *hba, u16 spsp, void *buffer, size_t len, bool send)
+{
+	struct scsi_device *sdev = hba->ufs_rpmb_wlun;
+	u8 cdb[12] = { };
+
+	cdb[0] = send ? SECURITY_PROTOCOL_OUT : SECURITY_PROTOCOL_IN;
+	cdb[1] = UFS_RPMB_SEC_PROTOCOL;
+	put_unaligned_be16(spsp, &cdb[2]);
+	put_unaligned_be32(len, &cdb[6]);
+
+	return scsi_execute_cmd(sdev, cdb, send ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
+				buffer, len, /*timeout=*/30 * HZ, 0, NULL);
+}
+
+/* UFS RPMB route frames implementation */
+static int ufs_rpmb_route_frames(struct device *dev, u8 *req, unsigned int req_len, u8 *resp,
+					unsigned int resp_len)
+{
+	struct ufs_rpmb_dev *ufs_rpmb = dev_get_drvdata(dev);
+	struct rpmb_frame *frm_out = (struct rpmb_frame *)req;
+	bool need_result_read = true;
+	u16 req_type, protocol_id;
+	struct ufs_hba *hba;
+	int ret;
+
+	if (!ufs_rpmb) {
+		dev_err(dev, "Missing driver data\n");
+		return -ENODEV;
+	}
+
+	if (!req || !req_len || !resp || !resp_len)
+		return -EINVAL;
+
+	hba = ufs_rpmb->hba;
+
+	req_type = be16_to_cpu(frm_out->req_resp);
+
+	switch (req_type) {
+	case RPMB_PROGRAM_KEY:
+		if (req_len != sizeof(struct rpmb_frame) || resp_len != sizeof(struct rpmb_frame))
+			return -EINVAL;
+		break;
+	case RPMB_GET_WRITE_COUNTER:
+		if (req_len != sizeof(struct rpmb_frame) || resp_len != sizeof(struct rpmb_frame))
+			return -EINVAL;
+		need_result_read = false;
+		break;
+	case RPMB_WRITE_DATA:
+		if (req_len % sizeof(struct rpmb_frame) || resp_len != sizeof(struct rpmb_frame))
+			return -EINVAL;
+		break;
+	case RPMB_READ_DATA:
+		if (req_len != sizeof(struct rpmb_frame) || resp_len % sizeof(struct rpmb_frame))
+			return -EINVAL;
+		need_result_read = false;
+		break;
+	default:
+		dev_err(dev, "Unknown request type=0x%04x\n", req_type);
+		return -EINVAL;
+	}
+
+	protocol_id = ufs_rpmb->region_id << 8 | UFS_RPMB_SEC_PROTOCOL_ID;
+
+	ret = ufs_sec_submit(hba, protocol_id, req, req_len, true);
+	if (ret) {
+		dev_err(dev, "Command failed with ret=%d\n", ret);
+		return ret;
+	}
+
+	if (need_result_read) {
+		struct rpmb_frame *frm_resp = (struct rpmb_frame *)resp;
+
+		memset(frm_resp, 0, sizeof(*frm_resp));
+		frm_resp->req_resp = cpu_to_be16(RPMB_RESULT_READ);
+		ret = ufs_sec_submit(hba, protocol_id, resp, resp_len, true);
+		if (ret) {
+			dev_err(dev, "Result read request failed with ret=%d\n", ret);
+			return ret;
+		}
+	}
+
+	if (!ret) {
+		ret = ufs_sec_submit(hba, protocol_id, resp, resp_len, false);
+		if (ret)
+			dev_err(dev, "Response read failed with ret=%d\n", ret);
+	}
+
+	return ret;
+}
+
+static void ufs_rpmb_device_release(struct device *dev)
+{
+	struct ufs_rpmb_dev *ufs_rpmb = dev_get_drvdata(dev);
+
+	if (ufs_rpmb->rdev)
+		rpmb_dev_unregister(ufs_rpmb->rdev);
+}
+
+/* UFS RPMB device registration */
+int ufs_rpmb_probe(struct ufs_hba *hba)
+{
+	struct ufs_rpmb_dev *ufs_rpmb, *it, *tmp;
+	struct rpmb_dev *rdev;
+	u8 cid[16] = { };
+	int region;
+	u8 *sn;
+	u32 cap;
+	int ret;
+
+	if (!hba->ufs_rpmb_wlun) {
+		dev_info(hba->dev, "No RPMB LUN, skip RPMB registration\n");
+		return -ENODEV;
+	}
+
+	/* Get the UNICODE serial number data */
+	sn = hba->dev_info.serial_number;
+	if (!sn) {
+		dev_err(hba->dev, "Serial number not available\n");
+		return -EINVAL;
+	}
+
+	INIT_LIST_HEAD(&hba->rpmbs);
+
+	/* Copy serial number into device ID (max 15 chars + NUL). */
+	strscpy(cid, sn, sizeof(cid));
+
+	struct rpmb_descr descr = {
+		.type = RPMB_TYPE_UFS,
+		.route_frames = ufs_rpmb_route_frames,
+		.dev_id_len = sizeof(cid),
+		.reliable_wr_count = hba->dev_info.rpmb_io_size,
+	};
+
+	for (region = 0; region < 4; region++) {
+		cap = hba->dev_info.rpmb_region_size[region];
+		if (!cap)
+			continue;
+
+		ufs_rpmb = devm_kzalloc(hba->dev, sizeof(*ufs_rpmb), GFP_KERNEL);
+		if (!ufs_rpmb) {
+			ret = -ENOMEM;
+			goto err_out;
+		}
+
+		ufs_rpmb->hba = hba;
+		ufs_rpmb->dev.parent = &hba->ufs_rpmb_wlun->sdev_gendev;
+		ufs_rpmb->dev.bus = &ufs_rpmb_bus_type;
+		ufs_rpmb->dev.release = ufs_rpmb_device_release;
+		dev_set_name(&ufs_rpmb->dev, "ufs_rpmb%d", region);
+
+		/* Set driver data BEFORE device_register */
+		dev_set_drvdata(&ufs_rpmb->dev, ufs_rpmb);
+
+		ret = device_register(&ufs_rpmb->dev);
+		if (ret) {
+			dev_err(hba->dev, "Failed to register UFS RPMB device %d\n", region);
+			put_device(&ufs_rpmb->dev);
+			goto err_out;
+		}
+
+		/* Make CID unique for this region by appending region numbe */
+		cid[sizeof(cid) - 1] = region;
+		descr.dev_id = (void *)cid;
+		descr.capacity = cap;
+
+		/* Register RPMB device */
+		rdev = rpmb_dev_register(&ufs_rpmb->dev, &descr);
+		if (IS_ERR(rdev)) {
+			dev_err(hba->dev, "Failed to register UFS RPMB device.\n");
+			device_unregister(&ufs_rpmb->dev);
+			ret = PTR_ERR(rdev);
+			goto err_out;
+		}
+
+		ufs_rpmb->rdev = rdev;
+		ufs_rpmb->region_id = region;
+
+		list_add_tail(&ufs_rpmb->node, &hba->rpmbs);
+
+		dev_info(hba->dev, "UFS RPMB region %d registered (capacity=%u)\n", region, cap);
+	}
+
+	return 0;
+err_out:
+	list_for_each_entry_safe(it, tmp, &hba->rpmbs, node) {
+		list_del(&it->node);
+		device_unregister(&it->dev);
+	}
+
+	return ret;
+}
+
+/* UFS RPMB remove handler */
+void ufs_rpmb_remove(struct ufs_hba *hba)
+{
+	struct ufs_rpmb_dev *ufs_rpmb, *tmp;
+
+	if (list_empty(&hba->rpmbs))
+		return;
+
+	/* Remove all registered RPMB devices */
+	list_for_each_entry_safe(ufs_rpmb, tmp, &hba->rpmbs, node) {
+		dev_info(hba->dev, "Removing UFS RPMB region %d\n", ufs_rpmb->region_id);
+		/* Remove from list first */
+		list_del(&ufs_rpmb->node);
+		/* Unregister device */
+		device_unregister(&ufs_rpmb->dev);
+	}
+
+	dev_info(hba->dev, "All UFS RPMB devices unregistered\n");
+}
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("OP-TEE RPMB subsystem based UFS RPMB driver");
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index d0a2c963a27d..523828d6b1d5 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -411,4 +411,17 @@ static inline u32 ufshcd_mcq_get_sq_head_slot(struct ufs_hw_queue *q)
 	return val / sizeof(struct utp_transfer_req_desc);
 }
 
+#ifdef CONFIG_RPMB
+int ufs_rpmb_probe(struct ufs_hba *hba);
+void ufs_rpmb_remove(struct ufs_hba *hba);
+#else
+static inline int ufs_rpmb_probe(struct ufs_hba *hba)
+{
+	return 0;
+}
+static inline void ufs_rpmb_remove(struct ufs_hba *hba)
+{
+}
+#endif
+
 #endif /* _UFSHCD_PRIV_H_ */
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 79c7588be28a..ec1670d94946 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5240,10 +5240,15 @@ static void ufshcd_lu_init(struct ufs_hba *hba, struct scsi_device *sdev)
 	    desc_buf[UNIT_DESC_PARAM_LU_WR_PROTECT] == UFS_LU_POWER_ON_WP)
 		hba->dev_info.is_lu_power_on_wp = true;
 
-	/* In case of RPMB LU, check if advanced RPMB mode is enabled */
-	if (desc_buf[UNIT_DESC_PARAM_UNIT_INDEX] == UFS_UPIU_RPMB_WLUN &&
-	    desc_buf[RPMB_UNIT_DESC_PARAM_REGION_EN] & BIT(4))
-		hba->dev_info.b_advanced_rpmb_en = true;
+	/* In case of RPMB LU, check if advanced RPMB mode is enabled, and get region size */
+	if (desc_buf[UNIT_DESC_PARAM_UNIT_INDEX] == UFS_UPIU_RPMB_WLUN) {
+		if (desc_buf[RPMB_UNIT_DESC_PARAM_REGION_EN] & BIT(4))
+			hba->dev_info.b_advanced_rpmb_en = true;
+		hba->dev_info.rpmb_region_size[0] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION0_SIZE];
+		hba->dev_info.rpmb_region_size[1] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION1_SIZE];
+		hba->dev_info.rpmb_region_size[2] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION2_SIZE];
+		hba->dev_info.rpmb_region_size[3] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION3_SIZE];
+	}
 
 
 	kfree(desc_buf);
@@ -8151,8 +8156,11 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
 		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN), NULL);
 	if (IS_ERR(sdev_rpmb)) {
 		ret = PTR_ERR(sdev_rpmb);
+		hba->ufs_rpmb_wlun = NULL;
+		dev_err(hba->dev, "%s: RPMB WLUN not found\n", __func__);
 		goto remove_ufs_device_wlun;
 	}
+	hba->ufs_rpmb_wlun = sdev_rpmb;
 	ufshcd_blk_pm_runtime_init(sdev_rpmb);
 	scsi_device_put(sdev_rpmb);
 
@@ -8425,6 +8433,7 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 	int err;
 	u8 model_index;
 	u8 *desc_buf;
+	u8 serial_index;
 	struct ufs_dev_info *dev_info = &hba->dev_info;
 
 	desc_buf = kzalloc(QUERY_DESC_MAX_SIZE, GFP_KERNEL);
@@ -8460,6 +8469,7 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 				UFS_DEV_HID_SUPPORT;
 
 	model_index = desc_buf[DEVICE_DESC_PARAM_PRDCT_NAME];
+	serial_index = desc_buf[DEVICE_DESC_PARAM_SN];
 
 	err = ufshcd_read_string_desc(hba, model_index,
 				      &dev_info->model, SD_ASCII_STD);
@@ -8469,6 +8479,12 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 		goto out;
 	}
 
+	err = ufshcd_read_string_desc(hba, serial_index, &dev_info->serial_number, SD_RAW);
+	if (err < 0) {
+		dev_err(hba->dev, "%s: Failed reading Serial Number. err = %d\n", __func__, err);
+		goto out;
+	}
+
 	hba->luns_avail = desc_buf[DEVICE_DESC_PARAM_NUM_LU] +
 		desc_buf[DEVICE_DESC_PARAM_NUM_WLU];
 
@@ -8504,6 +8520,8 @@ static void ufs_put_device_desc(struct ufs_hba *hba)
 
 	kfree(dev_info->model);
 	dev_info->model = NULL;
+	kfree(dev_info->serial_number);
+	dev_info->serial_number = NULL;
 }
 
 /**
@@ -8647,6 +8665,8 @@ static int ufshcd_device_geo_params_init(struct ufs_hba *hba)
 	else if (desc_buf[GEOMETRY_DESC_PARAM_MAX_NUM_LUN] == 0)
 		hba->dev_info.max_lu_supported = 8;
 
+	hba->dev_info.rpmb_io_size = desc_buf[GEOMETRY_DESC_PARAM_RPMB_RW_SIZE];
+
 out:
 	kfree(desc_buf);
 	return err;
@@ -8832,6 +8852,7 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
 
 	ufs_bsg_probe(hba);
 	scsi_scan_host(hba->host);
+	ufs_rpmb_probe(hba);
 
 out:
 	return ret;
@@ -10391,6 +10412,7 @@ void ufshcd_remove(struct ufs_hba *hba)
 		ufshcd_rpm_get_sync(hba);
 	ufs_hwmon_remove(hba);
 	ufs_bsg_remove(hba);
+	ufs_rpmb_remove(hba);
 	ufs_sysfs_remove_nodes(hba->dev);
 	cancel_delayed_work_sync(&hba->ufs_rtc_update_work);
 	blk_mq_destroy_queue(hba->tmf_queue);
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index 72fd385037a6..1d44e2b32253 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -651,6 +651,10 @@ struct ufs_dev_info {
 	u8 rtt_cap; /* bDeviceRTTCap */
 
 	bool hid_sup;
+
+	u8 *serial_number;
+	u8 rpmb_io_size;
+	u8 rpmb_region_size[4];
 };
 
 /*
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 1d3943777584..17e97a45ef71 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -984,6 +984,7 @@ struct ufs_hba {
 	struct Scsi_Host *host;
 	struct device *dev;
 	struct scsi_device *ufs_device_wlun;
+	struct scsi_device *ufs_rpmb_wlun;
 
 #ifdef CONFIG_SCSI_UFS_HWMON
 	struct device *hwmon_device;
@@ -1140,6 +1141,8 @@ struct ufs_hba {
 	int critical_health_count;
 	atomic_t dev_lvl_exception_count;
 	u64 dev_lvl_exception_id;
+
+	struct list_head rpmbs;
 };
 
 /**
-- 
2.34.1
Re: [PATCH v2 3/3] scsi: ufs: core: Add OP-TEE based RPMB driver for UFS devices
Posted by Bart Van Assche an hour ago
On 9/30/25 11:08 PM, Bean Huo wrote:
> +MODULE_DESCRIPTION("OP-TEE RPMB subsystem based UFS RPMB driver");

Hmm ... "OP-TEE UFS RPMB driver" is probably more clear and still
unambiguous. Anyway:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Re: [PATCH v2 3/3] scsi: ufs: core: Add OP-TEE based RPMB driver for UFS devices
Posted by Jens Wiklander 13 hours ago
Hi Bean,

On Wed, Oct 1, 2025 at 8:08 AM Bean Huo <beanhuo@iokpp.de> wrote:
>
> From: Bean Huo <beanhuo@micron.com>
>
> This patch adds OP-TEE based RPMB support for UFS devices. This enables secure RPMB operations on
> UFS devices through OP-TEE, providing the same functionality available for eMMC devices and
> extending kernel-based secure storage support to UFS-based systems.
>
> Benefits of OP-TEE based RPMB implementation:
> - Eliminates dependency on userspace supplicant for RPMB access
> - Enables early boot secure storage access (e.g., fTPM, secure UEFI variables)
> - Provides kernel-level RPMB access as soon as UFS driver is initialized
> - Removes complex initramfs dependencies and boot ordering requirements
> - Ensures reliable and deterministic secure storage operations
> - Supports both built-in and modular fTPM configurations
>
> Co-developed-by: Can Guo <can.guo@oss.qualcomm.com>
> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
> Signed-off-by: Bean Huo <beanhuo@micron.com>
> ---
>  drivers/misc/Kconfig           |   2 +-
>  drivers/ufs/core/Makefile      |   1 +
>  drivers/ufs/core/ufs-rpmb.c    | 253 +++++++++++++++++++++++++++++++++
>  drivers/ufs/core/ufshcd-priv.h |  13 ++
>  drivers/ufs/core/ufshcd.c      |  30 +++-
>  include/ufs/ufs.h              |   4 +
>  include/ufs/ufshcd.h           |   3 +
>  7 files changed, 301 insertions(+), 5 deletions(-)
>  create mode 100644 drivers/ufs/core/ufs-rpmb.c
>
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index b9ca56930003..46ffa62eac6e 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -106,7 +106,7 @@ config PHANTOM
>
>  config RPMB
>         tristate "RPMB partition interface"
> -       depends on MMC
> +       depends on MMC || SCSI_UFSHCD
>         help
>           Unified RPMB unit interface for RPMB capable devices such as eMMC and
>           UFS. Provides interface for in-kernel security controllers to access
> diff --git a/drivers/ufs/core/Makefile b/drivers/ufs/core/Makefile
> index cf820fa09a04..51e1867e524e 100644
> --- a/drivers/ufs/core/Makefile
> +++ b/drivers/ufs/core/Makefile
> @@ -2,6 +2,7 @@
>
>  obj-$(CONFIG_SCSI_UFSHCD)              += ufshcd-core.o
>  ufshcd-core-y                          += ufshcd.o ufs-sysfs.o ufs-mcq.o
> +ufshcd-core-$(CONFIG_RPMB)             += ufs-rpmb.o

SCSI_UFSHCD might need the same trick ("depends on RPMB || !RPMB") in
Kconfig as we have for MMC_BLOCK.

>  ufshcd-core-$(CONFIG_DEBUG_FS)         += ufs-debugfs.o
>  ufshcd-core-$(CONFIG_SCSI_UFS_BSG)     += ufs_bsg.o
>  ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO)  += ufshcd-crypto.o
> diff --git a/drivers/ufs/core/ufs-rpmb.c b/drivers/ufs/core/ufs-rpmb.c
> new file mode 100644
> index 000000000000..84cdcf8efeb3
> --- /dev/null
> +++ b/drivers/ufs/core/ufs-rpmb.c
> @@ -0,0 +1,253 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * UFS OP-TEE based RPMB Driver
> + *
> + * Copyright (C) 2025 Micron Technology, Inc.
> + * Copyright (C) 2025 Qualcomm Technologies, Inc.
> + *
> + * Authors:
> + *     Bean Huo <beanhuo@micron.com>
> + *     Can Guo <can.guo@oss.qualcomm.com>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/types.h>
> +#include <linux/rpmb.h>
> +#include <linux/string.h>
> +#include <linux/list.h>
> +#include <ufs/ufshcd.h>
> +#include <linux/unaligned.h>
> +#include "ufshcd-priv.h"
> +
> +#define UFS_RPMB_SEC_PROTOCOL          0xEC    /* JEDEC UFS application */
> +#define UFS_RPMB_SEC_PROTOCOL_ID       0x01    /* JEDEC UFS RPMB protocol ID, CDB byte3 */
> +
> +static const struct bus_type ufs_rpmb_bus_type = {
> +       .name = "ufs_rpmb",
> +};
> +
> +/* UFS RPMB device structure */
> +struct ufs_rpmb_dev {
> +       u8 region_id;
> +       struct device dev;
> +       struct rpmb_dev *rdev;
> +       struct ufs_hba *hba;
> +       struct list_head node;
> +};
> +
> +static int ufs_sec_submit(struct ufs_hba *hba, u16 spsp, void *buffer, size_t len, bool send)
> +{
> +       struct scsi_device *sdev = hba->ufs_rpmb_wlun;
> +       u8 cdb[12] = { };
> +
> +       cdb[0] = send ? SECURITY_PROTOCOL_OUT : SECURITY_PROTOCOL_IN;
> +       cdb[1] = UFS_RPMB_SEC_PROTOCOL;
> +       put_unaligned_be16(spsp, &cdb[2]);
> +       put_unaligned_be32(len, &cdb[6]);
> +
> +       return scsi_execute_cmd(sdev, cdb, send ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
> +                               buffer, len, /*timeout=*/30 * HZ, 0, NULL);
> +}
> +
> +/* UFS RPMB route frames implementation */
> +static int ufs_rpmb_route_frames(struct device *dev, u8 *req, unsigned int req_len, u8 *resp,
> +                                       unsigned int resp_len)
> +{
> +       struct ufs_rpmb_dev *ufs_rpmb = dev_get_drvdata(dev);
> +       struct rpmb_frame *frm_out = (struct rpmb_frame *)req;
> +       bool need_result_read = true;
> +       u16 req_type, protocol_id;
> +       struct ufs_hba *hba;
> +       int ret;
> +
> +       if (!ufs_rpmb) {
> +               dev_err(dev, "Missing driver data\n");
> +               return -ENODEV;
> +       }
> +
> +       if (!req || !req_len || !resp || !resp_len)
> +               return -EINVAL;

This function is only called indirectly from rpmb_route_frames(),
where this is already checked.

> +
> +       hba = ufs_rpmb->hba;
> +
> +       req_type = be16_to_cpu(frm_out->req_resp);
> +
> +       switch (req_type) {
> +       case RPMB_PROGRAM_KEY:
> +               if (req_len != sizeof(struct rpmb_frame) || resp_len != sizeof(struct rpmb_frame))
> +                       return -EINVAL;
> +               break;
> +       case RPMB_GET_WRITE_COUNTER:
> +               if (req_len != sizeof(struct rpmb_frame) || resp_len != sizeof(struct rpmb_frame))
> +                       return -EINVAL;
> +               need_result_read = false;
> +               break;
> +       case RPMB_WRITE_DATA:
> +               if (req_len % sizeof(struct rpmb_frame) || resp_len != sizeof(struct rpmb_frame))
> +                       return -EINVAL;
> +               break;
> +       case RPMB_READ_DATA:
> +               if (req_len != sizeof(struct rpmb_frame) || resp_len % sizeof(struct rpmb_frame))
> +                       return -EINVAL;
> +               need_result_read = false;
> +               break;
> +       default:
> +               dev_err(dev, "Unknown request type=0x%04x\n", req_type);
> +               return -EINVAL;
> +       }
> +
> +       protocol_id = ufs_rpmb->region_id << 8 | UFS_RPMB_SEC_PROTOCOL_ID;
> +
> +       ret = ufs_sec_submit(hba, protocol_id, req, req_len, true);
> +       if (ret) {
> +               dev_err(dev, "Command failed with ret=%d\n", ret);
> +               return ret;
> +       }
> +
> +       if (need_result_read) {
> +               struct rpmb_frame *frm_resp = (struct rpmb_frame *)resp;
> +
> +               memset(frm_resp, 0, sizeof(*frm_resp));
> +               frm_resp->req_resp = cpu_to_be16(RPMB_RESULT_READ);
> +               ret = ufs_sec_submit(hba, protocol_id, resp, resp_len, true);
> +               if (ret) {
> +                       dev_err(dev, "Result read request failed with ret=%d\n", ret);
> +                       return ret;
> +               }
> +       }
> +
> +       if (!ret) {
> +               ret = ufs_sec_submit(hba, protocol_id, resp, resp_len, false);
> +               if (ret)
> +                       dev_err(dev, "Response read failed with ret=%d\n", ret);
> +       }
> +
> +       return ret;
> +}
> +
> +static void ufs_rpmb_device_release(struct device *dev)
> +{
> +       struct ufs_rpmb_dev *ufs_rpmb = dev_get_drvdata(dev);
> +
> +       if (ufs_rpmb->rdev)

rpmb_dev_unregister() already checks rdev for NULL.

> +               rpmb_dev_unregister(ufs_rpmb->rdev);
> +}
> +
> +/* UFS RPMB device registration */
> +int ufs_rpmb_probe(struct ufs_hba *hba)
> +{
> +       struct ufs_rpmb_dev *ufs_rpmb, *it, *tmp;
> +       struct rpmb_dev *rdev;
> +       u8 cid[16] = { };
> +       int region;
> +       u8 *sn;
> +       u32 cap;
> +       int ret;
> +
> +       if (!hba->ufs_rpmb_wlun) {
> +               dev_info(hba->dev, "No RPMB LUN, skip RPMB registration\n");
> +               return -ENODEV;
> +       }
> +
> +       /* Get the UNICODE serial number data */
> +       sn = hba->dev_info.serial_number;
> +       if (!sn) {
> +               dev_err(hba->dev, "Serial number not available\n");
> +               return -EINVAL;
> +       }
> +
> +       INIT_LIST_HEAD(&hba->rpmbs);
> +
> +       /* Copy serial number into device ID (max 15 chars + NUL). */
> +       strscpy(cid, sn, sizeof(cid));

strscpy(cid, sn) is enough; strscpy() can determine the size itself
since cid is an array.

> +
> +       struct rpmb_descr descr = {
> +               .type = RPMB_TYPE_UFS,

We'll need another type if the device uses the extended RPMB frame
format. How about you clarify this, where RPMB_TYPE_UFS is defined to
avoid confusion?

> +               .route_frames = ufs_rpmb_route_frames,
> +               .dev_id_len = sizeof(cid),
> +               .reliable_wr_count = hba->dev_info.rpmb_io_size,
> +       };
> +
> +       for (region = 0; region < 4; region++) {

Would it make sense to use ARRAY_SIZE(hba->dev_info.rpmb_region_size)
to avoid another magic number?

> +               cap = hba->dev_info.rpmb_region_size[region];
> +               if (!cap)
> +                       continue;
> +
> +               ufs_rpmb = devm_kzalloc(hba->dev, sizeof(*ufs_rpmb), GFP_KERNEL);
> +               if (!ufs_rpmb) {
> +                       ret = -ENOMEM;
> +                       goto err_out;
> +               }
> +
> +               ufs_rpmb->hba = hba;
> +               ufs_rpmb->dev.parent = &hba->ufs_rpmb_wlun->sdev_gendev;
> +               ufs_rpmb->dev.bus = &ufs_rpmb_bus_type;
> +               ufs_rpmb->dev.release = ufs_rpmb_device_release;
> +               dev_set_name(&ufs_rpmb->dev, "ufs_rpmb%d", region);
> +
> +               /* Set driver data BEFORE device_register */
> +               dev_set_drvdata(&ufs_rpmb->dev, ufs_rpmb);
> +
> +               ret = device_register(&ufs_rpmb->dev);
> +               if (ret) {
> +                       dev_err(hba->dev, "Failed to register UFS RPMB device %d\n", region);
> +                       put_device(&ufs_rpmb->dev);
> +                       goto err_out;
> +               }
> +
> +               /* Make CID unique for this region by appending region numbe */
> +               cid[sizeof(cid) - 1] = region;
> +               descr.dev_id = (void *)cid;

Casting isn't needed; descr.dev_id has the same type as cid.

Cheers,
Jens

> +               descr.capacity = cap;
> +
> +               /* Register RPMB device */
> +               rdev = rpmb_dev_register(&ufs_rpmb->dev, &descr);
> +               if (IS_ERR(rdev)) {
> +                       dev_err(hba->dev, "Failed to register UFS RPMB device.\n");
> +                       device_unregister(&ufs_rpmb->dev);
> +                       ret = PTR_ERR(rdev);
> +                       goto err_out;
> +               }
> +
> +               ufs_rpmb->rdev = rdev;
> +               ufs_rpmb->region_id = region;
> +
> +               list_add_tail(&ufs_rpmb->node, &hba->rpmbs);
> +
> +               dev_info(hba->dev, "UFS RPMB region %d registered (capacity=%u)\n", region, cap);
> +       }
> +
> +       return 0;
> +err_out:
> +       list_for_each_entry_safe(it, tmp, &hba->rpmbs, node) {
> +               list_del(&it->node);
> +               device_unregister(&it->dev);
> +       }
> +
> +       return ret;
> +}
> +
> +/* UFS RPMB remove handler */
> +void ufs_rpmb_remove(struct ufs_hba *hba)
> +{
> +       struct ufs_rpmb_dev *ufs_rpmb, *tmp;
> +
> +       if (list_empty(&hba->rpmbs))
> +               return;
> +
> +       /* Remove all registered RPMB devices */
> +       list_for_each_entry_safe(ufs_rpmb, tmp, &hba->rpmbs, node) {
> +               dev_info(hba->dev, "Removing UFS RPMB region %d\n", ufs_rpmb->region_id);
> +               /* Remove from list first */
> +               list_del(&ufs_rpmb->node);
> +               /* Unregister device */
> +               device_unregister(&ufs_rpmb->dev);
> +       }
> +
> +       dev_info(hba->dev, "All UFS RPMB devices unregistered\n");
> +}
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("OP-TEE RPMB subsystem based UFS RPMB driver");
> diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
> index d0a2c963a27d..523828d6b1d5 100644
> --- a/drivers/ufs/core/ufshcd-priv.h
> +++ b/drivers/ufs/core/ufshcd-priv.h
> @@ -411,4 +411,17 @@ static inline u32 ufshcd_mcq_get_sq_head_slot(struct ufs_hw_queue *q)
>         return val / sizeof(struct utp_transfer_req_desc);
>  }
>
> +#ifdef CONFIG_RPMB
> +int ufs_rpmb_probe(struct ufs_hba *hba);
> +void ufs_rpmb_remove(struct ufs_hba *hba);
> +#else
> +static inline int ufs_rpmb_probe(struct ufs_hba *hba)
> +{
> +       return 0;
> +}
> +static inline void ufs_rpmb_remove(struct ufs_hba *hba)
> +{
> +}
> +#endif
> +
>  #endif /* _UFSHCD_PRIV_H_ */
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 79c7588be28a..ec1670d94946 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -5240,10 +5240,15 @@ static void ufshcd_lu_init(struct ufs_hba *hba, struct scsi_device *sdev)
>             desc_buf[UNIT_DESC_PARAM_LU_WR_PROTECT] == UFS_LU_POWER_ON_WP)
>                 hba->dev_info.is_lu_power_on_wp = true;
>
> -       /* In case of RPMB LU, check if advanced RPMB mode is enabled */
> -       if (desc_buf[UNIT_DESC_PARAM_UNIT_INDEX] == UFS_UPIU_RPMB_WLUN &&
> -           desc_buf[RPMB_UNIT_DESC_PARAM_REGION_EN] & BIT(4))
> -               hba->dev_info.b_advanced_rpmb_en = true;
> +       /* In case of RPMB LU, check if advanced RPMB mode is enabled, and get region size */
> +       if (desc_buf[UNIT_DESC_PARAM_UNIT_INDEX] == UFS_UPIU_RPMB_WLUN) {
> +               if (desc_buf[RPMB_UNIT_DESC_PARAM_REGION_EN] & BIT(4))
> +                       hba->dev_info.b_advanced_rpmb_en = true;

Does this indicate that the other RPMB frame format is used?

> +               hba->dev_info.rpmb_region_size[0] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION0_SIZE];
> +               hba->dev_info.rpmb_region_size[1] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION1_SIZE];
> +               hba->dev_info.rpmb_region_size[2] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION2_SIZE];
> +               hba->dev_info.rpmb_region_size[3] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION3_SIZE];
> +       }
>
>
>         kfree(desc_buf);
> @@ -8151,8 +8156,11 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
>                 ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN), NULL);
>         if (IS_ERR(sdev_rpmb)) {
>                 ret = PTR_ERR(sdev_rpmb);
> +               hba->ufs_rpmb_wlun = NULL;
> +               dev_err(hba->dev, "%s: RPMB WLUN not found\n", __func__);
>                 goto remove_ufs_device_wlun;
>         }
> +       hba->ufs_rpmb_wlun = sdev_rpmb;
>         ufshcd_blk_pm_runtime_init(sdev_rpmb);
>         scsi_device_put(sdev_rpmb);
>
> @@ -8425,6 +8433,7 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
>         int err;
>         u8 model_index;
>         u8 *desc_buf;
> +       u8 serial_index;
>         struct ufs_dev_info *dev_info = &hba->dev_info;
>
>         desc_buf = kzalloc(QUERY_DESC_MAX_SIZE, GFP_KERNEL);
> @@ -8460,6 +8469,7 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
>                                 UFS_DEV_HID_SUPPORT;
>
>         model_index = desc_buf[DEVICE_DESC_PARAM_PRDCT_NAME];
> +       serial_index = desc_buf[DEVICE_DESC_PARAM_SN];
>
>         err = ufshcd_read_string_desc(hba, model_index,
>                                       &dev_info->model, SD_ASCII_STD);
> @@ -8469,6 +8479,12 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
>                 goto out;
>         }
>
> +       err = ufshcd_read_string_desc(hba, serial_index, &dev_info->serial_number, SD_RAW);
> +       if (err < 0) {
> +               dev_err(hba->dev, "%s: Failed reading Serial Number. err = %d\n", __func__, err);
> +               goto out;
> +       }
> +
>         hba->luns_avail = desc_buf[DEVICE_DESC_PARAM_NUM_LU] +
>                 desc_buf[DEVICE_DESC_PARAM_NUM_WLU];
>
> @@ -8504,6 +8520,8 @@ static void ufs_put_device_desc(struct ufs_hba *hba)
>
>         kfree(dev_info->model);
>         dev_info->model = NULL;
> +       kfree(dev_info->serial_number);
> +       dev_info->serial_number = NULL;
>  }
>
>  /**
> @@ -8647,6 +8665,8 @@ static int ufshcd_device_geo_params_init(struct ufs_hba *hba)
>         else if (desc_buf[GEOMETRY_DESC_PARAM_MAX_NUM_LUN] == 0)
>                 hba->dev_info.max_lu_supported = 8;
>
> +       hba->dev_info.rpmb_io_size = desc_buf[GEOMETRY_DESC_PARAM_RPMB_RW_SIZE];
> +
>  out:
>         kfree(desc_buf);
>         return err;
> @@ -8832,6 +8852,7 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
>
>         ufs_bsg_probe(hba);
>         scsi_scan_host(hba->host);
> +       ufs_rpmb_probe(hba);
>
>  out:
>         return ret;
> @@ -10391,6 +10412,7 @@ void ufshcd_remove(struct ufs_hba *hba)
>                 ufshcd_rpm_get_sync(hba);
>         ufs_hwmon_remove(hba);
>         ufs_bsg_remove(hba);
> +       ufs_rpmb_remove(hba);
>         ufs_sysfs_remove_nodes(hba->dev);
>         cancel_delayed_work_sync(&hba->ufs_rtc_update_work);
>         blk_mq_destroy_queue(hba->tmf_queue);
> diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
> index 72fd385037a6..1d44e2b32253 100644
> --- a/include/ufs/ufs.h
> +++ b/include/ufs/ufs.h
> @@ -651,6 +651,10 @@ struct ufs_dev_info {
>         u8 rtt_cap; /* bDeviceRTTCap */
>
>         bool hid_sup;
> +
> +       u8 *serial_number;
> +       u8 rpmb_io_size;
> +       u8 rpmb_region_size[4];
>  };
>
>  /*
> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> index 1d3943777584..17e97a45ef71 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -984,6 +984,7 @@ struct ufs_hba {
>         struct Scsi_Host *host;
>         struct device *dev;
>         struct scsi_device *ufs_device_wlun;
> +       struct scsi_device *ufs_rpmb_wlun;
>
>  #ifdef CONFIG_SCSI_UFS_HWMON
>         struct device *hwmon_device;
> @@ -1140,6 +1141,8 @@ struct ufs_hba {
>         int critical_health_count;
>         atomic_t dev_lvl_exception_count;
>         u64 dev_lvl_exception_id;
> +
> +       struct list_head rpmbs;
>  };
>
>  /**
> --
> 2.34.1
>