On Tue, 11 May 2021 at 02:28, Peter Hilber <peter.hilber@xxxxxxxxxxxxxxx> wrote: > > From: Igor Skalkin <igor.skalkin@xxxxxxxxxxxxxxx> > > This transport enables accessing an SCMI platform as a virtio device. > > Implement an SCMI virtio driver according to the virtio SCMI device spec > [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, this implements the virtio transport as > paraphrased: > > Only support a single arm-scmi device (which is consistent with the SCMI > spec). scmi-virtio init is called 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. > > 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: > > - Polling is not supported. > > - The timeout for delayed responses has not been adjusted. > > [1] https://github.com/oasis-tcs/virtio-spec/blob/master/virtio-scmi.tex > [2] https://www.oasis-open.org/committees/ballot.php?id=3496 > > Signed-off-by: Igor Skalkin <igor.skalkin@xxxxxxxxxxxxxxx> > [ Peter: Adapted patch for submission to upstream. ] > Co-developed-by: Peter Hilber <peter.hilber@xxxxxxxxxxxxxxx> > Signed-off-by: Peter Hilber <peter.hilber@xxxxxxxxxxxxxxx> > --- > MAINTAINERS | 1 + > drivers/firmware/Kconfig | 12 + > drivers/firmware/arm_scmi/Makefile | 1 + > drivers/firmware/arm_scmi/common.h | 3 + > drivers/firmware/arm_scmi/driver.c | 3 + > drivers/firmware/arm_scmi/virtio.c | 523 +++++++++++++++++++++++++++++ > include/uapi/linux/virtio_ids.h | 1 + > include/uapi/linux/virtio_scmi.h | 25 ++ > 8 files changed, 569 insertions(+) > 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 bd7aff0c120f..449c336872f3 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -17705,6 +17705,7 @@ F: drivers/regulator/scmi-regulator.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@xxxxxxxxxx> > diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig > index e8377b12e4d0..7e9eafdd9b63 100644 > --- a/drivers/firmware/Kconfig > +++ b/drivers/firmware/Kconfig > @@ -39,6 +39,18 @@ config ARM_SCMI_HAVE_MSG > This declares whether a message passing based transport for SCMI is > available. > > +# This config option includes the dependencies of ARM_SCMI_PROTOCOL so that > +# this config doesn't show up when SCMI wouldn't be available. > +config VIRTIO_SCMI > + bool "Virtio transport for SCMI" > + select ARM_SCMI_HAVE_MSG > + depends on VIRTIO && (ARM || ARM64 || COMPILE_TEST) > + 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 f6b4acb8abdb..db1787606fb2 100644 > --- a/drivers/firmware/arm_scmi/Makefile > +++ b/drivers/firmware/arm_scmi/Makefile > @@ -5,6 +5,7 @@ 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_ARM_SCMI_HAVE_MSG) += msg.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 voltage.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 4cb6571c7aaf..bada06cfd33d 100644 > --- a/drivers/firmware/arm_scmi/common.h > +++ b/drivers/firmware/arm_scmi/common.h > @@ -349,6 +349,9 @@ 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 e04e7c8e6928..a31187385470 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -1637,6 +1637,9 @@ 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 */ }, > }; > diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c > new file mode 100644 > index 000000000000..20972adf6dc7 > --- /dev/null > +++ b/drivers/firmware/arm_scmi/virtio.c > @@ -0,0 +1,523 @@ > +// 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. > + * > + * 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 spinlocks. > + */ > + > +#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 VIRTIO_SCMI_MAX_PDU_SIZE \ > + (VIRTIO_SCMI_MAX_MSG_SIZE + SCMI_MSG_MAX_PROT_OVERHEAD) > +#define DESCRIPTORS_PER_TX_MSG 2 > + > +/** > + * struct scmi_vio_channel - Transport channel information > + * > + * @lock: Protects access to all members except ready. > + * @ready_lock: Protects access to ready. If required, it must be taken before > + * lock. > + * @vqueue: Associated virtqueue > + * @cinfo: SCMI Tx or Rx channel > + * @free_list: List of unused scmi_vio_msg, maintained for Tx channels only > + * @is_rx: Whether channel is an Rx channel > + * @ready: Whether transport user is ready to hear about channel > + */ > +struct scmi_vio_channel { > + spinlock_t lock; > + spinlock_t ready_lock; > + struct virtqueue *vqueue; > + struct scmi_chan_info *cinfo; > + struct list_head free_list; > + u8 is_rx; > + u8 ready; > +}; > + > +/** > + * struct scmi_vio_msg - Transport PDU information > + * > + * @request: SDU used for commands > + * @input: SDU used for (delayed) responses and notifications > + * @list: List which scmi_vio_msg may be part of > + * @rx_len: Input SDU size in bytes, once input has been received > + */ > +struct scmi_vio_msg { > + struct scmi_msg_payld *request; > + struct scmi_msg_payld *input; > + struct list_head list; > + unsigned int rx_len; > +}; > + > +static bool scmi_vio_have_vq_rx(struct virtio_device *vdev) > +{ > + return virtio_has_feature(vdev, VIRTIO_SCMI_F_P2A_CHANNELS); > +} > + > +static int scmi_vio_feed_vq_rx(struct scmi_vio_channel *vioch, > + struct scmi_vio_msg *msg) > +{ > + struct scatterlist sg_in; > + int rc; > + unsigned long flags; > + > + sg_init_one(&sg_in, msg->input, VIRTIO_SCMI_MAX_PDU_SIZE); > + > + spin_lock_irqsave(&vioch->lock, flags); > + > + rc = virtqueue_add_inbuf(vioch->vqueue, &sg_in, 1, msg, GFP_ATOMIC); > + if (rc) > + dev_err_once(vioch->cinfo->dev, > + "%s() failed to add to virtqueue (%d)\n", __func__, > + rc); > + else > + virtqueue_kick(vioch->vqueue); > + > + spin_unlock_irqrestore(&vioch->lock, flags); > + > + return rc; > +} > + > +static void scmi_vio_complete_cb(struct virtqueue *vqueue) > +{ > + unsigned long ready_flags; > + unsigned long flags; > + unsigned int length; > + struct scmi_vio_channel *vioch; > + struct scmi_vio_msg *msg; > + bool cb_enabled = true; > + > + if (WARN_ON_ONCE(!vqueue->vdev->priv)) > + return; > + vioch = &((struct scmi_vio_channel *)vqueue->vdev->priv)[vqueue->index]; > + > + for (;;) { > + spin_lock_irqsave(&vioch->ready_lock, ready_flags); > + > + if (!vioch->ready) { > + if (!cb_enabled) > + (void)virtqueue_enable_cb(vqueue); > + goto unlock_ready_out; > + } > + > + spin_lock_irqsave(&vioch->lock, flags); > + if (cb_enabled) { > + virtqueue_disable_cb(vqueue); > + cb_enabled = false; > + } > + msg = virtqueue_get_buf(vqueue, &length); > + if (!msg) { > + if (virtqueue_enable_cb(vqueue)) > + goto unlock_out; > + else > + cb_enabled = true; > + } > + spin_unlock_irqrestore(&vioch->lock, flags); > + > + if (msg) { > + msg->rx_len = length; > + > + /* > + * Hold the ready_lock during the callback to avoid > + * races when the arm-scmi driver is unbinding while > + * the virtio device is not quiesced yet. > + */ > + scmi_rx_callback(vioch->cinfo, > + msg_read_header(msg->input), msg); > + } > + spin_unlock_irqrestore(&vioch->ready_lock, ready_flags); > + } > + > +unlock_out: > + spin_unlock_irqrestore(&vioch->lock, flags); > +unlock_ready_out: > + spin_unlock_irqrestore(&vioch->ready_lock, ready_flags); > +} > + > +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 unsigned int virtio_get_max_msg(bool tx, > + struct scmi_chan_info *base_cinfo) > +{ > + struct scmi_vio_channel *vioch = base_cinfo->transport_info; > + unsigned int ret; > + > + ret = virtqueue_get_vring_size(vioch->vqueue); > + > + /* Tx messages need multiple descriptors. */() > + if (tx) > + ret /= DESCRIPTORS_PER_TX_MSG; > + > + if (ret > MSG_TOKEN_MAX) { __scmi_xfer_info_init() returns error for info->max_msg >= MSG_TOKEN_MAX so it should be (ret >= MSG_TOKEN_MAX > + dev_info_once( > + base_cinfo->dev, > + "Only %ld messages can be pending simultaneously, while the %s virtqueue could hold %d\n", > + MSG_TOKEN_MAX, tx ? "tx" : "rx", ret); > + ret = MSG_TOKEN_MAX; should be ret = MSG_TOKEN_MAX-1; > + } > + > + return ret; > +} > + > +static int scmi_vio_match_any_dev(struct device *dev, const 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 device link for remove order and sysfs link. */ > + 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; > + > + /* 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; > + > + switch (idx) { > + case VIRTIO_SCMI_VQ_TX: > + return true; > + case VIRTIO_SCMI_VQ_RX: > + return scmi_vio_have_vq_rx(vdev); > + default: > + return false; > + } > +} > + > +static int virtio_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, > + bool tx) > +{ > + unsigned long flags; > + struct virtio_device *vdev; > + struct scmi_vio_channel *vioch; > + int index = tx ? VIRTIO_SCMI_VQ_TX : VIRTIO_SCMI_VQ_RX; > + int max_msg; > + int i; > + > + if (!virtio_chan_available(dev, index)) > + return -ENODEV; > + > + vdev = scmi_get_transport_info(dev); > + vioch = &((struct scmi_vio_channel *)vdev->priv)[index]; > + > + spin_lock_irqsave(&vioch->lock, flags); > + cinfo->transport_info = vioch; > + vioch->cinfo = cinfo; > + spin_unlock_irqrestore(&vioch->lock, flags); > + > + max_msg = virtio_get_max_msg(tx, cinfo); > + > + for (i = 0; i < max_msg; i++) { > + struct scmi_vio_msg *msg; > + > + msg = devm_kzalloc(cinfo->dev, sizeof(*msg), GFP_KERNEL); > + if (!msg) > + return -ENOMEM; > + > + if (tx) { > + msg->request = devm_kzalloc(cinfo->dev, > + VIRTIO_SCMI_MAX_PDU_SIZE, > + GFP_KERNEL); > + if (!msg->request) > + return -ENOMEM; > + } > + > + msg->input = devm_kzalloc(cinfo->dev, VIRTIO_SCMI_MAX_PDU_SIZE, > + GFP_KERNEL); > + if (!msg->input) > + return -ENOMEM; > + > + if (tx) { > + spin_lock_irqsave(&vioch->lock, flags); > + list_add_tail(&msg->list, &vioch->free_list); > + spin_unlock_irqrestore(&vioch->lock, flags); > + } else { > + scmi_vio_feed_vq_rx(vioch, msg); > + } > + } > + > + spin_lock_irqsave(&vioch->ready_lock, flags); > + vioch->ready = true; > + spin_unlock_irqrestore(&vioch->ready_lock, flags); > + > + return 0; > +} > + > +static int virtio_chan_free(int id, void *p, void *data) > +{ > + unsigned long flags; > + struct scmi_chan_info *cinfo = p; > + struct scmi_vio_channel *vioch = cinfo->transport_info; > + > + spin_lock_irqsave(&vioch->ready_lock, flags); > + vioch->ready = false; > + spin_unlock_irqrestore(&vioch->ready_lock, flags); > + > + scmi_free_channel(cinfo, data, id); > + return 0; > +} > + > +static int virtio_send_message(struct scmi_chan_info *cinfo, > + struct scmi_xfer *xfer) > +{ > + struct scmi_vio_channel *vioch = cinfo->transport_info; > + struct scatterlist sg_out; > + struct scatterlist sg_in; > + struct scatterlist *sgs[DESCRIPTORS_PER_TX_MSG] = { &sg_out, &sg_in }; > + unsigned long flags; > + int rc; > + struct scmi_vio_msg *msg; > + > + /* > + * TODO: For now, we don't support polling. But it should not be > + * difficult to add support. > + */ > + if (xfer->hdr.poll_completion) > + return -EINVAL; > + > + spin_lock_irqsave(&vioch->lock, flags); > + > + if (list_empty(&vioch->free_list)) { > + spin_unlock_irqrestore(&vioch->lock, flags); > + return -EBUSY; > + } > + > + msg = list_first_entry(&vioch->free_list, typeof(*msg), list); > + list_del(&msg->list); > + > + msg_tx_prepare(msg->request, xfer); > + > + sg_init_one(&sg_out, msg->request, msg_command_size(xfer)); > + sg_init_one(&sg_in, msg->input, msg_response_size(xfer)); > + > + rc = virtqueue_add_sgs(vioch->vqueue, sgs, 1, 1, msg, GFP_ATOMIC); > + if (rc) { > + list_add(&msg->list, &vioch->free_list); > + dev_err_once(vioch->cinfo->dev, > + "%s() failed to add to virtqueue (%d)\n", __func__, > + rc); > + } else { > + virtqueue_kick(vioch->vqueue); > + } > + > + spin_unlock_irqrestore(&vioch->lock, flags); > + > + return rc; > +} > + > +static void virtio_fetch_response(struct scmi_chan_info *cinfo, > + struct scmi_xfer *xfer, void *msg_handle) > +{ > + struct scmi_vio_msg *msg = msg_handle; > + struct scmi_vio_channel *vioch = cinfo->transport_info; > + > + if (!msg) { > + dev_dbg_once(&vioch->vqueue->vdev->dev, > + "Ignoring %s() call with NULL msg_handle\n", > + __func__); > + return; > + } > + > + msg_fetch_response(msg->input, msg->rx_len, xfer); > +} > + > +static void virtio_fetch_notification(struct scmi_chan_info *cinfo, > + size_t max_len, struct scmi_xfer *xfer, > + void *msg_handle) > +{ > + struct scmi_vio_msg *msg = msg_handle; > + struct scmi_vio_channel *vioch = cinfo->transport_info; > + > + if (!msg) { > + dev_dbg_once(&vioch->vqueue->vdev->dev, > + "Ignoring %s() call with NULL msg_handle\n", > + __func__); > + return; > + } > + > + msg_fetch_notification(msg->input, msg->rx_len, max_len, xfer); > +} > + > +static void dummy_clear_channel(struct scmi_chan_info *cinfo) > +{ > +} > + > +static bool dummy_poll_done(struct scmi_chan_info *cinfo, > + struct scmi_xfer *xfer) > +{ > + return false; > +} > + > +static void virtio_drop_message(struct scmi_chan_info *cinfo, void *msg_handle) > +{ > + unsigned long flags; > + struct scmi_vio_channel *vioch = cinfo->transport_info; > + struct scmi_vio_msg *msg = msg_handle; > + > + if (!msg) { > + dev_dbg_once(&vioch->vqueue->vdev->dev, > + "Ignoring %s() call with NULL msg_handle\n", > + __func__); > + return; > + } > + > + if (vioch->is_rx) { > + scmi_vio_feed_vq_rx(vioch, msg); > + } else { > + spin_lock_irqsave(&vioch->lock, flags); > + list_add(&msg->list, &vioch->free_list); > + spin_unlock_irqrestore(&vioch->lock, flags); > + } > +} > + > +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 = virtio_fetch_notification, > + .clear_channel = dummy_clear_channel, > + .poll_done = dummy_poll_done, > + .drop_message = virtio_drop_message, > +}; > + > +static int scmi_vio_probe(struct virtio_device *vdev) > +{ > + struct device *dev = &vdev->dev; > + struct scmi_vio_channel *channels; > + bool have_vq_rx; > + int vq_cnt; > + int i; > + int ret; > + struct virtqueue *vqs[VIRTIO_SCMI_VQ_MAX_CNT]; > + > + have_vq_rx = scmi_vio_have_vq_rx(vdev); > + vq_cnt = have_vq_rx ? VIRTIO_SCMI_VQ_MAX_CNT : 1; > + > + channels = devm_kcalloc(dev, vq_cnt, sizeof(*channels), GFP_KERNEL); > + if (!channels) > + return -ENOMEM; > + > + if (have_vq_rx) > + channels[VIRTIO_SCMI_VQ_RX].is_rx = true; > + > + ret = virtio_find_vqs(vdev, vq_cnt, vqs, scmi_vio_complete_callbacks, > + scmi_vio_vqueue_names, NULL); > + if (ret) { > + dev_err(dev, "Failed to get %d virtqueue(s)\n", vq_cnt); > + return ret; > + } > + dev_info(dev, "Found %d virtqueue(s)\n", vq_cnt); > + > + for (i = 0; i < vq_cnt; i++) { > + spin_lock_init(&channels[i].lock); > + spin_lock_init(&channels[i].ready_lock); > + INIT_LIST_HEAD(&channels[i].free_list); > + channels[i].vqueue = vqs[i]; > + } > + > + vdev->priv = channels; > + > + return 0; > +} > + > +static void scmi_vio_remove(struct virtio_device *vdev) > +{ > + vdev->config->reset(vdev); > + vdev->config->del_vqs(vdev); > +} > + > +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, > + .remove = scmi_vio_remove, > +}; > + > +static int __init virtio_scmi_init(void) > +{ > + return register_virtio_driver(&virtio_scmi_driver); > +} > + > +static void __exit virtio_scmi_exit(void) > +{ > + unregister_virtio_driver(&virtio_scmi_driver); > +} > + > +const struct scmi_desc scmi_virtio_desc = { > + .init = virtio_scmi_init, > + .exit = virtio_scmi_exit, > + .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, > +}; > diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h > index f0c35ce8628c..c146fe30e589 100644 > --- a/include/uapi/linux/virtio_ids.h > +++ b/include/uapi/linux/virtio_ids.h > @@ -56,5 +56,6 @@ > #define VIRTIO_ID_PMEM 27 /* virtio pmem */ > #define VIRTIO_ID_BT 28 /* virtio bluetooth */ > #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..732b01504c35 > --- /dev/null > +++ b/include/uapi/linux/virtio_scmi.h > @@ -0,0 +1,25 @@ > +/* 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 > + > +#endif /* _UAPI_LINUX_VIRTIO_SCMI_H */ > -- > 2.25.1 > >
