From nobody Wed Dec 17 12:29:00 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BF554189530; Mon, 12 Aug 2024 17:34:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723484077; cv=none; b=XdHDv4MgpXqi/YcZhpW57Kk2eUmycappYNYax7rAY9hJnTxgpizKPH37DqLgDFjkOo3Cv8xddvhh2zR9t1LUsBb2YAnkXtdjQmOA0QHlC8mswGaK8XIHLuZ5dbGHZCdkSEyeX3w5IMJVaVf3vFnBm8XKWWzT70CiSTh1qiqons0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723484077; c=relaxed/simple; bh=1s+3uBeaykMLzUQUbJ0e98eyEEAzvL6rq41OTgXKFBE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=meOUMwhvW6fxneQ+IVgVsOtgp+IGfS7Y17gRDs9PhWIhr2r1Sf1PfgUj65sV/+Dk4JyDwH3EM5dP9P1QSdYEkYnVJNHxQrQ5Z8Kx1Bhjjn8uq4JTkfFmML62zM7sk3Pv/7cjz9UySy3+enSRnw9WXa9YMHXH7/A/r4buMVc/Sr4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1AB53FEC; Mon, 12 Aug 2024 10:35:01 -0700 (PDT) Received: from pluto.guestnet.cambridge.arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 30CC03F40C; Mon, 12 Aug 2024 10:34:32 -0700 (PDT) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, arm-scmi@vger.kernel.org Cc: sudeep.holla@arm.com, james.quinlan@broadcom.com, f.fainelli@gmail.com, vincent.guittot@linaro.org, etienne.carriere@st.com, peng.fan@oss.nxp.com, michal.simek@amd.com, quic_sibis@quicinc.com, quic_nkela@quicinc.com, ptosi@google.com, dan.carpenter@linaro.org, souvik.chakravarty@arm.com, Cristian Marussi , "Michael S . Tsirkin" , Igor Skalkin , Peter Hilber Subject: [PATCH v4 8/9] firmware: arm_scmi: Make VirtIO transport a standalone driver Date: Mon, 12 Aug 2024 18:33:39 +0100 Message-ID: <20240812173340.3912830-9-cristian.marussi@arm.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240812173340.3912830-1-cristian.marussi@arm.com> References: <20240812173340.3912830-1-cristian.marussi@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Make SCMI VirtIO transport a standalone driver that can be optionally loaded as a module. CC: Michael S. Tsirkin CC: Igor Skalkin CC: Peter Hilber Signed-off-by: Cristian Marussi --- v3 --> v4 - dropped MODULE_ALIAS - moved VIRTIO transport to its own subdir and submenu v2 --> v3 - fixed spacing in Kconfig and Copyright - use new params in DEFINE_SCMI_TRANSPORT_DRIVER v1 --> v2 - handle platform_driver_register() failures - make scmi_virtio_desc static | Reported-by: kernel test robot | Closes: https://lore.kernel.org/oe-kbuild-all/202407081344.9OceqFie-lkp@intel.com/ --- drivers/firmware/arm_scmi/Kconfig | 41 ------- drivers/firmware/arm_scmi/Makefile | 1 - drivers/firmware/arm_scmi/common.h | 3 - drivers/firmware/arm_scmi/driver.c | 3 - drivers/firmware/arm_scmi/transports/Kconfig | 43 ++++++++ drivers/firmware/arm_scmi/transports/Makefile | 2 + .../arm_scmi/{ =3D> transports}/virtio.c | 103 +++++++++--------- 7 files changed, 99 insertions(+), 97 deletions(-) rename drivers/firmware/arm_scmi/{ =3D> transports}/virtio.c (94%) diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/= Kconfig index b5e3634a8399..67053c1862d1 100644 --- a/drivers/firmware/arm_scmi/Kconfig +++ b/drivers/firmware/arm_scmi/Kconfig @@ -71,47 +71,6 @@ config ARM_SCMI_DEBUG_COUNTERS =20 source "drivers/firmware/arm_scmi/transports/Kconfig" =20 -config ARM_SCMI_TRANSPORT_VIRTIO - bool "SCMI transport based on VirtIO" - depends on VIRTIO=3Dy || VIRTIO=3DARM_SCMI_PROTOCOL - select ARM_SCMI_HAVE_TRANSPORT - select ARM_SCMI_HAVE_MSG - help - This enables the virtio based transport for SCMI. - - If you want the ARM SCMI PROTOCOL stack to include support for a - transport based on VirtIO, answer Y. - -config ARM_SCMI_TRANSPORT_VIRTIO_VERSION1_COMPLIANCE - bool "SCMI VirtIO transport Version 1 compliance" - depends on ARM_SCMI_TRANSPORT_VIRTIO - default y - help - This enforces strict compliance with VirtIO Version 1 specification. - - If you want the ARM SCMI VirtIO transport layer to refuse to work - with Legacy VirtIO backends and instead support only VirtIO Version 1 - devices (or above), answer Y. - - If you want instead to support also old Legacy VirtIO backends (like - the ones implemented by kvmtool) and let the core Kernel VirtIO layer - take care of the needed conversions, say N. - -config ARM_SCMI_TRANSPORT_VIRTIO_ATOMIC_ENABLE - bool "Enable atomic mode for SCMI VirtIO transport" - depends on ARM_SCMI_TRANSPORT_VIRTIO - help - Enable support of atomic operation for SCMI VirtIO based transport. - - If you want the SCMI VirtIO based transport to operate in atomic - mode, avoiding any kind of sleeping behaviour for selected - transactions on the TX path, answer Y. - - Enabling atomic mode operations allows any SCMI driver using this - transport to optionally ask for atomic SCMI transactions and operate - in atomic context too, at the price of using a number of busy-waiting - primitives all over instead. If unsure say N. - endif #ARM_SCMI_PROTOCOL =20 config ARM_SCMI_POWER_CONTROL diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi= /Makefile index b80b302186da..dc786f8215b6 100644 --- a/drivers/firmware/arm_scmi/Makefile +++ b/drivers/firmware/arm_scmi/Makefile @@ -6,7 +6,6 @@ scmi-driver-y =3D driver.o notify.o scmi-driver-$(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) +=3D raw_mode.o scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) =3D shmem.o scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) +=3D msg.o -scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO) +=3D virtio.o scmi-protocols-y :=3D base.o clock.o perf.o power.o reset.o sensors.o syst= em.o voltage.o powercap.o scmi-protocols-y +=3D pinctrl.o scmi-module-objs :=3D $(scmi-driver-y) $(scmi-protocols-y) $(scmi-transpor= t-y) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi= /common.h index 18026d446b59..7a53412fc41c 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -286,9 +286,6 @@ int scmi_xfer_raw_inflight_register(const struct scmi_h= andle *handle, int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer, unsigned int timeout_ms); -#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO -extern const struct scmi_desc scmi_virtio_desc; -#endif =20 void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *pri= v); =20 diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi= /driver.c index 084936e9575d..12643b4c0db3 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -3318,9 +3318,6 @@ ATTRIBUTE_GROUPS(versions); =20 /* Each compatible listed below must have descriptor associated with it */ static const struct of_device_id scmi_of_match[] =3D { -#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO - { .compatible =3D "arm,scmi-virtio", .data =3D &scmi_virtio_desc}, -#endif { /* Sentinel */ }, }; =20 diff --git a/drivers/firmware/arm_scmi/transports/Kconfig b/drivers/firmwar= e/arm_scmi/transports/Kconfig index 7d478a4f69df..57eccf316e26 100644 --- a/drivers/firmware/arm_scmi/transports/Kconfig +++ b/drivers/firmware/arm_scmi/transports/Kconfig @@ -77,4 +77,47 @@ config ARM_SCMI_TRANSPORT_OPTEE This driver can also be built as a module. If so, the module will be called scmi_transport_optee. =20 +config ARM_SCMI_TRANSPORT_VIRTIO + tristate "SCMI transport based on VirtIO" + depends on VIRTIO + select ARM_SCMI_HAVE_TRANSPORT + select ARM_SCMI_HAVE_MSG + help + This enables the virtio based transport for SCMI. + + If you want the ARM SCMI PROTOCOL stack to include support for a + transport based on VirtIO, answer Y. + This driver can also be built as a module. If so, the module + will be called scmi_transport_virtio. + +config ARM_SCMI_TRANSPORT_VIRTIO_VERSION1_COMPLIANCE + bool "SCMI VirtIO transport Version 1 compliance" + depends on ARM_SCMI_TRANSPORT_VIRTIO + default y + help + This enforces strict compliance with VirtIO Version 1 specification. + + If you want the ARM SCMI VirtIO transport layer to refuse to work + with Legacy VirtIO backends and instead support only VirtIO Version 1 + devices (or above), answer Y. + + If you want instead to support also old Legacy VirtIO backends (like + the ones implemented by kvmtool) and let the core Kernel VirtIO layer + take care of the needed conversions, say N. + +config ARM_SCMI_TRANSPORT_VIRTIO_ATOMIC_ENABLE + bool "Enable atomic mode for SCMI VirtIO transport" + depends on ARM_SCMI_TRANSPORT_VIRTIO + help + Enable support of atomic operation for SCMI VirtIO based transport. + + If you want the SCMI VirtIO based transport to operate in atomic + mode, avoiding any kind of sleeping behaviour for selected + transactions on the TX path, answer Y. + + Enabling atomic mode operations allows any SCMI driver using this + transport to optionally ask for atomic SCMI transactions and operate + in atomic context too, at the price of using a number of busy-waiting + primitives all over instead. If unsure say N. + endmenu diff --git a/drivers/firmware/arm_scmi/transports/Makefile b/drivers/firmwa= re/arm_scmi/transports/Makefile index 7c06d36a38fb..b08686571712 100644 --- a/drivers/firmware/arm_scmi/transports/Makefile +++ b/drivers/firmware/arm_scmi/transports/Makefile @@ -5,3 +5,5 @@ scmi_transport_smc-objs :=3D smc.o obj-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) +=3D scmi_transport_smc.o scmi_transport_optee-objs :=3D optee.o obj-$(CONFIG_ARM_SCMI_TRANSPORT_OPTEE) +=3D scmi_transport_optee.o +scmi_transport_virtio-objs :=3D virtio.o +obj-$(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO) +=3D scmi_transport_virtio.o diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi= /transports/virtio.c similarity index 94% rename from drivers/firmware/arm_scmi/virtio.c rename to drivers/firmware/arm_scmi/transports/virtio.c index e8d38e822c7e..c107579e7fe7 100644 --- a/drivers/firmware/arm_scmi/virtio.c +++ b/drivers/firmware/arm_scmi/transports/virtio.c @@ -4,7 +4,7 @@ * (SCMI). * * Copyright (C) 2020-2022 OpenSynergy. - * Copyright (C) 2021-2022 ARM Ltd. + * Copyright (C) 2021-2024 ARM Ltd. */ =20 /** @@ -19,6 +19,7 @@ =20 #include #include +#include #include #include #include @@ -27,7 +28,7 @@ #include #include =20 -#include "common.h" +#include "../common.h" =20 #define VIRTIO_MAX_RX_TIMEOUT_MS 60000 #define VIRTIO_SCMI_MAX_MSG_SIZE 128 /* Value may be increased. */ @@ -108,6 +109,8 @@ struct scmi_vio_msg { refcount_t users; }; =20 +static struct scmi_transport_core_operations *core; + /* Only one SCMI VirtIO device can possibly exist */ static struct virtio_device *scmi_vdev; =20 @@ -294,8 +297,9 @@ static void scmi_vio_complete_cb(struct virtqueue *vque= ue) =20 if (msg) { msg->rx_len =3D length; - scmi_rx_callback(vioch->cinfo, - scmi_msg_ops.read_header(msg->input), msg); + core->rx_callback(vioch->cinfo, + core->msg->read_header(msg->input), + msg); =20 scmi_finalize_message(vioch, msg); } @@ -339,8 +343,9 @@ static void scmi_vio_deferred_tx_worker(struct work_str= uct *work) * is no more processed elsewhere so no poll_lock needed. */ if (msg->poll_status =3D=3D VIO_MSG_NOT_POLLED) - scmi_rx_callback(vioch->cinfo, - scmi_msg_ops.read_header(msg->input), msg); + core->rx_callback(vioch->cinfo, + core->msg->read_header(msg->input), + msg); =20 /* Free the processed message once done */ scmi_vio_msg_release(vioch, msg); @@ -366,23 +371,6 @@ static unsigned int virtio_get_max_msg(struct scmi_cha= n_info *base_cinfo) return vioch->max_msg; } =20 -static int virtio_link_supplier(struct device *dev) -{ - if (!scmi_vdev) { - dev_notice(dev, - "Deferring probe after not finding a bound scmi-virtio device\n"); - return -EPROBE_DEFER; - } - - if (!device_link_add(dev, &scmi_vdev->dev, - DL_FLAG_AUTOREMOVE_CONSUMER)) { - dev_err(dev, "Adding link to supplier virtio device failed\n"); - return -ECANCELED; - } - - return 0; -} - static bool virtio_chan_available(struct device_node *of_node, int idx) { struct scmi_vio_channel *channels, *vioch =3D NULL; @@ -510,10 +498,10 @@ static int virtio_send_message(struct scmi_chan_info = *cinfo, return -EBUSY; } =20 - scmi_msg_ops.tx_prepare(msg->request, xfer); + core->msg->tx_prepare(msg->request, xfer); =20 - sg_init_one(&sg_out, msg->request, scmi_msg_ops.command_size(xfer)); - sg_init_one(&sg_in, msg->input, scmi_msg_ops.response_size(xfer)); + sg_init_one(&sg_out, msg->request, core->msg->command_size(xfer)); + sg_init_one(&sg_in, msg->input, core->msg->response_size(xfer)); =20 spin_lock_irqsave(&vioch->lock, flags); =20 @@ -560,7 +548,7 @@ static void virtio_fetch_response(struct scmi_chan_info= *cinfo, struct scmi_vio_msg *msg =3D xfer->priv; =20 if (msg) - scmi_msg_ops.fetch_response(msg->input, msg->rx_len, xfer); + core->msg->fetch_response(msg->input, msg->rx_len, xfer); } =20 static void virtio_fetch_notification(struct scmi_chan_info *cinfo, @@ -569,7 +557,8 @@ static void virtio_fetch_notification(struct scmi_chan_= info *cinfo, struct scmi_vio_msg *msg =3D xfer->priv; =20 if (msg) - scmi_msg_ops.fetch_notification(msg->input, msg->rx_len, max_len, xfer); + core->msg->fetch_notification(msg->input, msg->rx_len, + max_len, xfer); } =20 /** @@ -669,7 +658,7 @@ static void virtio_mark_txdone(struct scmi_chan_info *c= info, int ret, * the message we are polling for could be alternatively delivered via usu= al * IRQs callbacks on another core which happened to have IRQs enabled whil= e we * are actively polling for it here: in such a case it will be handled as = such - * by scmi_rx_callback() and the polling loop in the SCMI Core TX path wil= l be + * by rx_callback() and the polling loop in the SCMI Core TX path will be * transparently terminated anyway. * * Return: True once polling has successfully completed. @@ -790,7 +779,6 @@ static bool virtio_poll_done(struct scmi_chan_info *cin= fo, } =20 static const struct scmi_transport_ops scmi_virtio_ops =3D { - .link_supplier =3D virtio_link_supplier, .chan_available =3D virtio_chan_available, .chan_setup =3D virtio_chan_setup, .chan_free =3D virtio_chan_free, @@ -802,6 +790,23 @@ static const struct scmi_transport_ops scmi_virtio_ops= =3D { .poll_done =3D virtio_poll_done, }; =20 +static const struct scmi_desc scmi_virtio_desc =3D { + .ops =3D &scmi_virtio_ops, + /* for non-realtime virtio devices */ + .max_rx_timeout_ms =3D VIRTIO_MAX_RX_TIMEOUT_MS, + .max_msg =3D 0, /* overridden by virtio_get_max_msg() */ + .max_msg_size =3D VIRTIO_SCMI_MAX_MSG_SIZE, + .atomic_enabled =3D IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO_ATOMIC_EN= ABLE), +}; + +static const struct of_device_id scmi_of_match[] =3D { + { .compatible =3D "arm,scmi-virtio" }, + { /* Sentinel */ }, +}; + +DEFINE_SCMI_TRANSPORT_DRIVER(scmi_virtio, scmi_virtio_driver, scmi_virtio_= desc, + scmi_of_match, core); + static int scmi_vio_probe(struct virtio_device *vdev) { struct device *dev =3D &vdev->dev; @@ -861,14 +866,27 @@ static int scmi_vio_probe(struct virtio_device *vdev) } =20 vdev->priv =3D channels; + /* Ensure initialized scmi_vdev is visible */ smp_store_mb(scmi_vdev, vdev); =20 + ret =3D platform_driver_register(&scmi_virtio_driver); + if (ret) { + vdev->priv =3D NULL; + vdev->config->del_vqs(vdev); + /* Ensure NULLified scmi_vdev is visible */ + smp_store_mb(scmi_vdev, NULL); + + return ret; + } + return 0; } =20 static void scmi_vio_remove(struct virtio_device *vdev) { + platform_driver_unregister(&scmi_virtio_driver); + /* * Once we get here, virtio_chan_free() will have already been called by * the SCMI core for any existing channel and, as a consequence, all the @@ -913,23 +931,10 @@ static struct virtio_driver virtio_scmi_driver =3D { .validate =3D scmi_vio_validate, }; =20 -static int __init virtio_scmi_init(void) -{ - return register_virtio_driver(&virtio_scmi_driver); -} - -static void virtio_scmi_exit(void) -{ - unregister_virtio_driver(&virtio_scmi_driver); -} +module_virtio_driver(virtio_scmi_driver); =20 -const struct scmi_desc scmi_virtio_desc =3D { - .transport_init =3D virtio_scmi_init, - .transport_exit =3D virtio_scmi_exit, - .ops =3D &scmi_virtio_ops, - /* for non-realtime virtio devices */ - .max_rx_timeout_ms =3D VIRTIO_MAX_RX_TIMEOUT_MS, - .max_msg =3D 0, /* overridden by virtio_get_max_msg() */ - .max_msg_size =3D VIRTIO_SCMI_MAX_MSG_SIZE, - .atomic_enabled =3D IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO_ATOMIC_EN= ABLE), -}; +MODULE_AUTHOR("Igor Skalkin "); +MODULE_AUTHOR("Peter Hilber "); +MODULE_AUTHOR("Cristian Marussi "); +MODULE_DESCRIPTION("SCMI VirtIO Transport driver"); +MODULE_LICENSE("GPL"); --=20 2.45.2