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Diffstat (limited to 'meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0010-firmware-arm_scmi-Add-virtio-transport.patch')
-rw-r--r--meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0010-firmware-arm_scmi-Add-virtio-transport.patch756
1 files changed, 0 insertions, 756 deletions
diff --git a/meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0010-firmware-arm_scmi-Add-virtio-transport.patch b/meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0010-firmware-arm_scmi-Add-virtio-transport.patch
deleted file mode 100644
index 35ea04f8..00000000
--- a/meta-egvirt/recipes-kernel/linux/linux-yocto/virtio-scmi/0010-firmware-arm_scmi-Add-virtio-transport.patch
+++ /dev/null
@@ -1,756 +0,0 @@
-From 7b9f3fe0766d6d36ca7465e54754df51ca175079 Mon Sep 17 00:00:00 2001
-From: Igor Skalkin <igor.skalkin@opensynergy.com>
-Date: Thu, 5 Nov 2020 22:21:16 +0100
-Subject: [PATCH] firmware: arm_scmi: Add virtio transport
-
-This transport enables accessing an SCMI platform as a virtio device.
-
-Implement an SCMI virtio driver according to the virtio SCMI device spec
-patch v5 [1]. Virtio device id 32 has been reserved for the SCMI device
-[2].
-
-The virtio transport has one tx channel (virtio cmdq, A2P channel) and
-at most one rx channel (virtio eventq, P2A channel).
-
-The following feature bit defined in [1] is not implemented:
-VIRTIO_SCMI_F_SHARED_MEMORY.
-
-After the preparatory patches, implement the virtio transport as
-paraphrased:
-
-Only support a single arm-scmi device (which is consistent with the SCMI
-spec). Call scmi-virtio init from arm-scmi module init. During the
-arm-scmi probing, link to the first probed scmi-virtio device. Defer
-arm-scmi probing if no scmi-virtio device is bound yet.
-
-Use the scmi_xfer tx/rx buffers for data exchange with the virtio device
-in order to avoid redundant maintenance of additional buffers. Allocate
-the buffers in the SCMI transport, and prepend room for a small header
-used by the virtio transport to the tx/rx buffers.
-
-For simplicity, restrict the number of messages which can be pending
-simultaneously according to the virtqueue capacity. (The virtqueue sizes
-are negotiated with the virtio device.)
-
-As soon as rx channel message buffers are allocated or have been read
-out by the arm-scmi driver, feed them to the virtio device.
-
-Since some virtio devices may not have the short response time exhibited
-by SCMI platforms using other transports, set a generous response
-timeout.
-
-Limitations:
-
-Do not adjust the other SCMI timeouts for delayed response and polling
-for now, since these timeouts are only relevant in special cases which
-are not yet deemed relevant for this transport.
-
-To do (as discussed in the cover letter):
-
-- Avoid re-use of buffers still being used by the virtio device on
- timeouts.
-
-- Avoid race conditions on receiving messages during/after channel free
- on driver probe failure or remove.
-
-[1] https://lists.oasis-open.org/archives/virtio-comment/202005/msg00096.html
-[2] https://www.oasis-open.org/committees/ballot.php?id=3496
-
-Co-developed-by: Peter Hilber <peter.hilber@opensynergy.com>
-Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
-Signed-off-by: Igor Skalkin <igor.skalkin@opensynergy.com>
-Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
----
- MAINTAINERS | 1 +
- drivers/firmware/Kconfig | 12 +-
- drivers/firmware/arm_scmi/Makefile | 1 +
- drivers/firmware/arm_scmi/common.h | 14 +
- drivers/firmware/arm_scmi/driver.c | 11 +
- drivers/firmware/arm_scmi/virtio.c | 493 +++++++++++++++++++++++++++++
- include/uapi/linux/virtio_ids.h | 1 +
- include/uapi/linux/virtio_scmi.h | 41 +++
- 8 files changed, 573 insertions(+), 1 deletion(-)
- create mode 100644 drivers/firmware/arm_scmi/virtio.c
- create mode 100644 include/uapi/linux/virtio_scmi.h
-
-diff --git a/MAINTAINERS b/MAINTAINERS
-index 49772b741967..d223a5c3f465 100644
---- a/MAINTAINERS
-+++ b/MAINTAINERS
-@@ -16973,6 +16973,7 @@ F: drivers/firmware/arm_scpi.c
- F: drivers/reset/reset-scmi.c
- F: include/linux/sc[mp]i_protocol.h
- F: include/trace/events/scmi.h
-+F: include/uapi/linux/virtio_scmi.h
-
- SYSTEM RESET/SHUTDOWN DRIVERS
- M: Sebastian Reichel <sre@kernel.org>
-diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
-index 30a85d38d0c0..82e97904bcae 100644
---- a/drivers/firmware/Kconfig
-+++ b/drivers/firmware/Kconfig
-@@ -9,7 +9,7 @@ menu "Firmware Drivers"
- config ARM_SCMI_PROTOCOL
- tristate "ARM System Control and Management Interface (SCMI) Message Protocol"
- depends on ARM || ARM64 || COMPILE_TEST
-- depends on ARM_SCMI_HAVE_SHMEM
-+ depends on ARM_SCMI_HAVE_SHMEM || VIRTIO_SCMI
- help
- ARM System Control and Management Interface (SCMI) protocol is a
- set of operating system-independent software interfaces that are
-@@ -34,6 +34,16 @@ config ARM_SCMI_HAVE_SHMEM
- This declares whether a shared memory based transport for SCMI is
- available.
-
-+config VIRTIO_SCMI
-+ bool "Virtio transport for SCMI"
-+ default n
-+ depends on VIRTIO
-+ help
-+ This enables the virtio based transport for SCMI.
-+
-+ If you want to use the ARM SCMI protocol between the virtio guest and
-+ a host providing a virtio SCMI device, answer Y.
-+
- config ARM_SCMI_POWER_DOMAIN
- tristate "SCMI power domain driver"
- depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
-diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
-index 3cc7fa40a464..25caea5e1969 100644
---- a/drivers/firmware/arm_scmi/Makefile
-+++ b/drivers/firmware/arm_scmi/Makefile
-@@ -4,6 +4,7 @@ scmi-driver-y = driver.o notify.o
- scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o
- scmi-transport-$(CONFIG_MAILBOX) += mailbox.o
- scmi-transport-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smc.o
-+scmi-transport-$(CONFIG_VIRTIO_SCMI) += virtio.o
- scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o
- scmi-module-objs := $(scmi-bus-y) $(scmi-driver-y) $(scmi-protocols-y) \
- $(scmi-transport-y)
-diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
-index 13c9ac176b23..b46dfe84e78b 100644
---- a/drivers/firmware/arm_scmi/common.h
-+++ b/drivers/firmware/arm_scmi/common.h
-@@ -165,6 +165,17 @@ int scmi_base_protocol_init(struct scmi_handle *h);
- int __init scmi_bus_init(void);
- void __exit scmi_bus_exit(void);
-
-+#ifdef CONFIG_VIRTIO_SCMI
-+int __init virtio_scmi_init(void);
-+void __exit virtio_scmi_exit(void);
-+#else
-+static inline int __init virtio_scmi_init(void)
-+{
-+ return 0;
-+}
-+#define virtio_scmi_exit() do { } while (0)
-+#endif
-+
- #define DECLARE_SCMI_REGISTER_UNREGISTER(func) \
- int __init scmi_##func##_register(void); \
- void __exit scmi_##func##_unregister(void)
-@@ -263,6 +274,9 @@ extern const struct scmi_desc scmi_mailbox_desc;
- #ifdef CONFIG_HAVE_ARM_SMCCC
- extern const struct scmi_desc scmi_smc_desc;
- #endif
-+#ifdef CONFIG_VIRTIO_SCMI
-+extern const struct scmi_desc scmi_virtio_desc;
-+#endif
-
- int scmi_set_transport_info(struct device *dev, void *transport_info);
- void *scmi_get_transport_info(struct device *dev);
-diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
-index 93ce17bb4079..540a55285349 100644
---- a/drivers/firmware/arm_scmi/driver.c
-+++ b/drivers/firmware/arm_scmi/driver.c
-@@ -996,6 +996,9 @@ static const struct of_device_id scmi_of_match[] = {
- #endif
- #ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
- { .compatible = "arm,scmi-smc", .data = &scmi_smc_desc},
-+#endif
-+#ifdef CONFIG_VIRTIO_SCMI
-+ { .compatible = "arm,scmi-virtio", .data = &scmi_virtio_desc},
- #endif
- { /* Sentinel */ },
- };
-@@ -1014,8 +1017,14 @@ static struct platform_driver scmi_driver = {
-
- static int __init scmi_driver_init(void)
- {
-+ int ret;
-+
- scmi_bus_init();
-
-+ ret = virtio_scmi_init();
-+ if (ret)
-+ return ret;
-+
- scmi_clock_register();
- scmi_perf_register();
- scmi_power_register();
-@@ -1038,6 +1047,8 @@ static void __exit scmi_driver_exit(void)
- scmi_sensors_unregister();
- scmi_system_unregister();
-
-+ virtio_scmi_exit();
-+
- platform_driver_unregister(&scmi_driver);
- }
- module_exit(scmi_driver_exit);
-diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c
-new file mode 100644
-index 000000000000..f70aa72f34f1
---- /dev/null
-+++ b/drivers/firmware/arm_scmi/virtio.c
-@@ -0,0 +1,493 @@
-+// SPDX-License-Identifier: GPL-2.0
-+/*
-+ * Virtio Transport driver for Arm System Control and Management Interface
-+ * (SCMI).
-+ *
-+ * Copyright (C) 2020 OpenSynergy.
-+ */
-+
-+/**
-+ * DOC: Theory of Operation
-+ *
-+ * The scmi-virtio transport implements a driver for the virtio SCMI device
-+ * proposed in virtio spec patch v5[1].
-+ *
-+ * There is one tx channel (virtio cmdq, A2P channel) and at most one rx
-+ * channel (virtio eventq, P2A channel). Each channel is implemented through a
-+ * virtqueue. Access to each virtqueue is protected by a spinlock.
-+ *
-+ * This SCMI transport uses the scmi_xfer tx/rx buffers for data exchange with
-+ * the virtio device to avoid maintenance of additional buffers.
-+ *
-+ * [1] https://lists.oasis-open.org/archives/virtio-comment/202005/msg00096.html
-+ */
-+
-+#include <linux/errno.h>
-+#include <linux/of.h>
-+#include <linux/of_platform.h>
-+#include <linux/platform_device.h>
-+#include <linux/module.h>
-+#include <linux/slab.h>
-+#include <linux/virtio.h>
-+#include <linux/virtio_config.h>
-+#include <uapi/linux/virtio_ids.h>
-+#include <uapi/linux/virtio_scmi.h>
-+
-+#include "common.h"
-+
-+#define VIRTIO_SCMI_MAX_MSG_SIZE 128 /* Value may be increased. */
-+#define DESCR_PER_TX_MSG 2
-+
-+struct scmi_vio_channel {
-+ spinlock_t lock;
-+ struct virtqueue *vqueue;
-+ struct scmi_chan_info *cinfo;
-+ u8 is_rx;
-+};
-+
-+union virtio_scmi_input {
-+ __virtio32 hdr;
-+ struct virtio_scmi_response response;
-+ struct virtio_scmi_notification notification;
-+};
-+
-+struct scmi_vio_msg {
-+ struct virtio_scmi_request *request;
-+ union virtio_scmi_input *input;
-+ u8 completed;
-+};
-+
-+static int scmi_vio_populate_vq_rx(struct scmi_vio_channel *vioch,
-+ struct scmi_xfer *xfer)
-+{
-+ struct scatterlist sg_in;
-+ struct scmi_vio_msg *msg = xfer->extra_data;
-+ int rc;
-+
-+ msg->completed = false;
-+
-+ sg_init_one(&sg_in, msg->input,
-+ sizeof(*msg->input) + VIRTIO_SCMI_MAX_MSG_SIZE);
-+
-+ rc = virtqueue_add_inbuf(vioch->vqueue, &sg_in, 1, xfer, GFP_ATOMIC);
-+ if (rc)
-+ dev_err(vioch->cinfo->dev, "%s() rc=%d\n", __func__, rc);
-+ else
-+ virtqueue_kick(vioch->vqueue);
-+
-+ return rc;
-+}
-+
-+static void scmi_vio_complete_cb(struct virtqueue *vqueue)
-+{
-+ struct scmi_vio_channel *vioch = vqueue->priv;
-+ unsigned long iflags;
-+ unsigned int length;
-+
-+ spin_lock_irqsave(&vioch->lock, iflags);
-+
-+ do {
-+ struct scmi_xfer *xfer;
-+
-+ virtqueue_disable_cb(vqueue);
-+
-+ while ((xfer = virtqueue_get_buf(vqueue, &length))) {
-+ struct scmi_vio_msg *msg = xfer->extra_data;
-+ u32 msg_hdr =
-+ virtio32_to_cpu(vqueue->vdev, msg->input->hdr);
-+ u8 msg_type = MSG_XTRACT_TYPE(msg_hdr);
-+
-+ if (!vioch->is_rx) { /* tx queue response */
-+ msg->completed = true;
-+ xfer->rx.len =
-+ length - sizeof(msg->input->response);
-+ if (!xfer->hdr.poll_completion)
-+ scmi_rx_callback(vioch->cinfo, msg_hdr);
-+ continue;
-+ }
-+
-+ /* rx queue - notification or delayed response */
-+ switch (msg_type) {
-+ case MSG_TYPE_NOTIFICATION:
-+ xfer->rx.len = length -
-+ sizeof(msg->input->notification);
-+ xfer->rx.buf = msg->input->notification.data;
-+ break;
-+ case MSG_TYPE_DELAYED_RESP:
-+ xfer->rx.len =
-+ length - sizeof(msg->input->response);
-+ xfer->rx.buf = msg->input->response.data;
-+ break;
-+ default:
-+ dev_warn_once(vioch->cinfo->dev,
-+ "rx: unknown message_type %d\n",
-+ msg_type);
-+ scmi_vio_populate_vq_rx(vioch, xfer);
-+ continue;
-+ }
-+
-+ scmi_rx_callback(vioch->cinfo, msg_hdr);
-+ scmi_vio_populate_vq_rx(vioch, xfer);
-+ }
-+
-+ if (unlikely(virtqueue_is_broken(vqueue)))
-+ break;
-+ } while (!virtqueue_enable_cb(vqueue));
-+
-+ spin_unlock_irqrestore(&vioch->lock, iflags);
-+}
-+
-+static const char *const scmi_vio_vqueue_names[] = { "tx", "rx" };
-+
-+static vq_callback_t *scmi_vio_complete_callbacks[] = {
-+ scmi_vio_complete_cb,
-+ scmi_vio_complete_cb
-+};
-+
-+static int scmi_vio_match_any_dev(struct device *dev, const void *data)
-+{
-+ (void)dev;
-+ (void)data;
-+
-+ return 1;
-+}
-+
-+static struct virtio_driver virtio_scmi_driver; /* Forward declaration */
-+
-+static int virtio_link_supplier(struct device *dev)
-+{
-+ struct device *vdev = driver_find_device(
-+ &virtio_scmi_driver.driver, NULL, NULL, scmi_vio_match_any_dev);
-+
-+ if (!vdev) {
-+ dev_notice_once(
-+ dev,
-+ "Deferring probe after not finding a bound scmi-virtio device\n");
-+ return -EPROBE_DEFER;
-+ }
-+
-+ /*
-+ * Add plain device link for completeness. It might have no effect
-+ * beyond sysfs.
-+ */
-+ if (!device_link_add(dev, vdev, DL_FLAG_AUTOREMOVE_CONSUMER)) {
-+ put_device(vdev);
-+ dev_err(dev, "Adding link to supplier virtio device failed\n");
-+ return -ECANCELED;
-+ }
-+
-+ put_device(vdev);
-+ return scmi_set_transport_info(dev, dev_to_virtio(vdev));
-+}
-+
-+static bool virtio_chan_available(struct device *dev, int idx)
-+{
-+ struct virtio_device *vdev;
-+ struct scmi_vio_channel **vioch;
-+
-+ /* scmi-virtio doesn't support per-protocol channels */
-+ if (is_scmi_protocol_device(dev))
-+ return false;
-+
-+ vdev = scmi_get_transport_info(dev);
-+ if (!vdev)
-+ return false;
-+
-+ vioch = vdev->priv;
-+ if (!vioch)
-+ return false;
-+
-+ return vioch[idx] && vioch[idx]->vqueue;
-+}
-+
-+static int virtio_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
-+ bool tx)
-+{
-+ struct virtio_device *vdev;
-+ struct scmi_vio_channel **vioch;
-+ int vioch_index = tx ? VIRTIO_SCMI_VQ_TX : VIRTIO_SCMI_VQ_RX;
-+
-+ /* scmi-virtio doesn't support per-protocol channels */
-+ if (is_scmi_protocol_device(dev))
-+ return -1;
-+
-+ vdev = scmi_get_transport_info(dev);
-+ if (!vdev)
-+ return -1;
-+
-+ vioch = vdev->priv;
-+ if (!vioch) {
-+ dev_err(dev, "Data from scmi-virtio probe not found\n");
-+ return -1;
-+ }
-+ cinfo->transport_info = vioch[vioch_index];
-+ vioch[vioch_index]->cinfo = cinfo;
-+
-+ return 0;
-+}
-+
-+static int virtio_chan_free(int id, void *p, void *data)
-+{
-+ struct scmi_chan_info *cinfo = p;
-+ struct scmi_vio_channel *vioch = cinfo->transport_info;
-+
-+ if (vioch) {
-+ cinfo->transport_info = NULL;
-+ kfree(vioch);
-+ }
-+
-+ scmi_free_channel(cinfo, data, id);
-+ return 0;
-+}
-+
-+static int virtio_get_max_msg(bool tx, struct scmi_chan_info *base_cinfo,
-+ int *max_msg)
-+{
-+ struct scmi_vio_channel *vioch = base_cinfo->transport_info;
-+
-+ *max_msg = virtqueue_get_vring_size(vioch->vqueue);
-+
-+ /* Tx messages need multiple descriptors. */
-+ if (tx)
-+ *max_msg /= DESCR_PER_TX_MSG;
-+
-+ if (*max_msg > MSG_TOKEN_MAX) {
-+ dev_notice(
-+ base_cinfo->dev,
-+ "Only %ld messages can be pending simultaneously, while the virtqueue could hold %d\n",
-+ MSG_TOKEN_MAX, *max_msg);
-+ *max_msg = MSG_TOKEN_MAX;
-+ }
-+
-+ return 0;
-+}
-+
-+static int virtio_xfer_init_buffers(struct scmi_chan_info *cinfo,
-+ struct scmi_xfer *xfer, int max_msg_size)
-+{
-+ struct scmi_vio_channel *vioch = cinfo->transport_info;
-+ struct scmi_vio_msg *msg;
-+
-+ msg = devm_kzalloc(cinfo->dev, sizeof(*msg), GFP_KERNEL);
-+ if (!msg)
-+ return -ENOMEM;
-+
-+ xfer->extra_data = msg;
-+
-+ if (vioch->is_rx) {
-+ int rc;
-+ unsigned long iflags;
-+
-+ msg->input = devm_kzalloc(cinfo->dev,
-+ sizeof(*msg->input) + max_msg_size,
-+ GFP_KERNEL);
-+ if (!msg->input)
-+ return -ENOMEM;
-+
-+ /*
-+ * xfer->rx.buf will be set to notification or delayed response
-+ * specific values in the receive callback, according to the
-+ * type of the received message.
-+ */
-+
-+ spin_lock_irqsave(&vioch->lock, iflags);
-+ rc = scmi_vio_populate_vq_rx(vioch, xfer);
-+ spin_unlock_irqrestore(&vioch->lock, iflags);
-+ if (rc)
-+ return rc;
-+ } else {
-+ msg->request =
-+ devm_kzalloc(cinfo->dev,
-+ sizeof(*msg->request) + max_msg_size,
-+ GFP_KERNEL);
-+ if (!msg->request)
-+ return -ENOMEM;
-+
-+ xfer->tx.buf = msg->request->data;
-+
-+ msg->input = devm_kzalloc(
-+ cinfo->dev, sizeof(msg->input->response) + max_msg_size,
-+ GFP_KERNEL);
-+ if (!msg->input)
-+ return -ENOMEM;
-+
-+ xfer->rx.buf = msg->input->response.data;
-+ }
-+
-+ return 0;
-+}
-+
-+static int scmi_vio_send(struct scmi_vio_channel *vioch, struct scmi_xfer *xfer)
-+{
-+ struct scatterlist sg_out;
-+ struct scatterlist sg_in;
-+ struct scatterlist *sgs[DESCR_PER_TX_MSG] = { &sg_out, &sg_in };
-+ struct scmi_vio_msg *msg = xfer->extra_data;
-+ unsigned long iflags;
-+ int rc;
-+
-+ msg->completed = false;
-+
-+ sg_init_one(&sg_out, msg->request,
-+ sizeof(*msg->request) + xfer->tx.len);
-+ sg_init_one(&sg_in, &msg->input->response,
-+ sizeof(msg->input->response) + xfer->rx.len);
-+
-+ spin_lock_irqsave(&vioch->lock, iflags);
-+ rc = virtqueue_add_sgs(vioch->vqueue, sgs, 1, 1, xfer, GFP_ATOMIC);
-+ if (rc)
-+ dev_err(vioch->cinfo->dev, "%s() rc=%d\n", __func__, rc);
-+ else
-+ virtqueue_kick(vioch->vqueue);
-+ spin_unlock_irqrestore(&vioch->lock, iflags);
-+
-+ return rc;
-+}
-+
-+static int virtio_send_message(struct scmi_chan_info *cinfo,
-+ struct scmi_xfer *xfer)
-+{
-+ uint32_t hdr;
-+ struct scmi_vio_channel *vioch = cinfo->transport_info;
-+ struct virtio_device *vdev = vioch->vqueue->vdev;
-+ struct scmi_vio_msg *msg = xfer->extra_data;
-+
-+ hdr = pack_scmi_header(&xfer->hdr);
-+
-+ msg->request->hdr = cpu_to_virtio32(vdev, hdr);
-+
-+ return scmi_vio_send(vioch, xfer);
-+}
-+
-+static void virtio_fetch_response(struct scmi_chan_info *cinfo,
-+ struct scmi_xfer *xfer)
-+{
-+ struct scmi_vio_channel *vioch = cinfo->transport_info;
-+ struct scmi_vio_msg *msg = xfer->extra_data;
-+
-+ xfer->hdr.status = virtio32_to_cpu(vioch->vqueue->vdev,
-+ msg->input->response.status);
-+}
-+
-+static void dummy_fetch_notification(struct scmi_chan_info *cinfo,
-+ size_t max_len, struct scmi_xfer *xfer)
-+{
-+ (void)cinfo;
-+ (void)max_len;
-+ (void)xfer;
-+}
-+
-+static void dummy_clear_channel(struct scmi_chan_info *cinfo)
-+{
-+ (void)cinfo;
-+}
-+
-+static bool virtio_poll_done(struct scmi_chan_info *cinfo,
-+ struct scmi_xfer *xfer)
-+{
-+ struct scmi_vio_channel *vioch = cinfo->transport_info;
-+ struct scmi_vio_msg *msg = xfer->extra_data;
-+ unsigned long iflags;
-+ bool completed;
-+
-+ spin_lock_irqsave(&vioch->lock, iflags);
-+ completed = msg->completed;
-+ spin_unlock_irqrestore(&vioch->lock, iflags);
-+
-+ return completed;
-+}
-+
-+static const struct scmi_transport_ops scmi_virtio_ops = {
-+ .link_supplier = virtio_link_supplier,
-+ .chan_available = virtio_chan_available,
-+ .chan_setup = virtio_chan_setup,
-+ .chan_free = virtio_chan_free,
-+ .get_max_msg = virtio_get_max_msg,
-+ .send_message = virtio_send_message,
-+ .fetch_response = virtio_fetch_response,
-+ .fetch_notification = dummy_fetch_notification,
-+ .clear_channel = dummy_clear_channel,
-+ .poll_done = virtio_poll_done,
-+ .xfer_init_buffers = virtio_xfer_init_buffers,
-+};
-+
-+const struct scmi_desc scmi_virtio_desc = {
-+ .ops = &scmi_virtio_ops,
-+ .max_rx_timeout_ms = 60000, /* for non-realtime virtio devices */
-+ .max_msg = 0, /* overridden by virtio_get_max_msg() */
-+ .max_msg_size = VIRTIO_SCMI_MAX_MSG_SIZE,
-+};
-+
-+static int scmi_vio_probe(struct virtio_device *vdev)
-+{
-+ struct device *dev = &vdev->dev;
-+ struct scmi_vio_channel **vioch;
-+ bool have_vq_rx;
-+ int vq_cnt;
-+ int i;
-+ struct virtqueue *vqs[VIRTIO_SCMI_VQ_MAX_CNT];
-+
-+ vioch = devm_kcalloc(dev, VIRTIO_SCMI_VQ_MAX_CNT, sizeof(*vioch),
-+ GFP_KERNEL);
-+ if (!vioch)
-+ return -ENOMEM;
-+
-+ have_vq_rx = virtio_has_feature(vdev, VIRTIO_SCMI_F_P2A_CHANNELS);
-+ vq_cnt = have_vq_rx ? VIRTIO_SCMI_VQ_MAX_CNT : 1;
-+
-+ for (i = 0; i < vq_cnt; i++) {
-+ vioch[i] = devm_kzalloc(dev, sizeof(**vioch), GFP_KERNEL);
-+ if (!vioch[i])
-+ return -ENOMEM;
-+ }
-+
-+ if (have_vq_rx)
-+ vioch[VIRTIO_SCMI_VQ_RX]->is_rx = true;
-+
-+ if (virtio_find_vqs(vdev, vq_cnt, vqs, scmi_vio_complete_callbacks,
-+ scmi_vio_vqueue_names, NULL)) {
-+ dev_err(dev, "Failed to get %d virtqueue(s)\n", vq_cnt);
-+ return -1;
-+ }
-+ dev_info(dev, "Found %d virtqueue(s)\n", vq_cnt);
-+
-+ for (i = 0; i < vq_cnt; i++) {
-+ spin_lock_init(&vioch[i]->lock);
-+ vioch[i]->vqueue = vqs[i];
-+ vioch[i]->vqueue->priv = vioch[i];
-+ }
-+
-+ vdev->priv = vioch;
-+
-+ virtio_device_ready(vdev);
-+
-+ return 0;
-+}
-+
-+static unsigned int features[] = {
-+ VIRTIO_SCMI_F_P2A_CHANNELS,
-+};
-+
-+static const struct virtio_device_id id_table[] = {
-+ { VIRTIO_ID_SCMI, VIRTIO_DEV_ANY_ID },
-+ { 0 }
-+};
-+
-+static struct virtio_driver virtio_scmi_driver = {
-+ .driver.name = "scmi-virtio",
-+ .driver.owner = THIS_MODULE,
-+ .feature_table = features,
-+ .feature_table_size = ARRAY_SIZE(features),
-+ .id_table = id_table,
-+ .probe = scmi_vio_probe,
-+};
-+
-+int __init virtio_scmi_init(void)
-+{
-+ return register_virtio_driver(&virtio_scmi_driver);
-+}
-+
-+void __exit virtio_scmi_exit(void)
-+{
-+ unregister_virtio_driver(&virtio_scmi_driver);
-+}
-diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h
-index bc740d6d2259..287daba2abdb 100644
---- a/include/uapi/linux/virtio_ids.h
-+++ b/include/uapi/linux/virtio_ids.h
-@@ -49,5 +49,6 @@
- #define VIRTIO_ID_FS 26 /* virtio filesystem */
- #define VIRTIO_ID_PMEM 27 /* virtio pmem */
- #define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */
-+#define VIRTIO_ID_SCMI 32 /* virtio SCMI */
-
- #endif /* _LINUX_VIRTIO_IDS_H */
-diff --git a/include/uapi/linux/virtio_scmi.h b/include/uapi/linux/virtio_scmi.h
-new file mode 100644
-index 000000000000..9f21b3dbbfe2
---- /dev/null
-+++ b/include/uapi/linux/virtio_scmi.h
-@@ -0,0 +1,41 @@
-+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
-+/*
-+ * Copyright (C) 2020 OpenSynergy GmbH
-+ */
-+
-+#ifndef _UAPI_LINUX_VIRTIO_SCMI_H
-+#define _UAPI_LINUX_VIRTIO_SCMI_H
-+
-+#include <linux/virtio_types.h>
-+
-+/* Feature bits */
-+
-+/* Device implements some SCMI notifications, or delayed responses. */
-+#define VIRTIO_SCMI_F_P2A_CHANNELS 0
-+
-+/* Device implements any SCMI statistics shared memory region */
-+#define VIRTIO_SCMI_F_SHARED_MEMORY 1
-+
-+/* Virtqueues */
-+
-+#define VIRTIO_SCMI_VQ_TX 0 /* cmdq */
-+#define VIRTIO_SCMI_VQ_RX 1 /* eventq */
-+#define VIRTIO_SCMI_VQ_MAX_CNT 2
-+
-+struct virtio_scmi_request {
-+ __virtio32 hdr;
-+ __u8 data[];
-+};
-+
-+struct virtio_scmi_response {
-+ __virtio32 hdr;
-+ __virtio32 status;
-+ __u8 data[];
-+};
-+
-+struct virtio_scmi_notification {
-+ __virtio32 hdr;
-+ __u8 data[];
-+};
-+
-+#endif /* _UAPI_LINUX_VIRTIO_SCMI_H */