On Tue, Aug 03, 2021 at 02:10:24PM +0100, Cristian Marussi wrote: > From: Igor Skalkin <[email protected]> > > This transport enables communications with an SCMI platform through virtio; > the SCMI platform will be represented by 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. > > The number of messages which can be pending simultaneously is restricted > according to the virtqueue capacity negotiated at probing time. > > As soon as Rx channel message buffers are allocated or have been read > out by the arm-scmi driver, feed them back 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. > > SCMI polling mode is not supported by this virtio transport since deemed > meaningless: polling mode operation is offered by the SCMI core to those > transports that could not provide a completion interrupt on the TX path, > which is never the case for virtio whose core callbacks can easily call > into core scmi_rx_callback upon messages reception. > > [1] https://github.com/oasis-tcs/virtio-spec/blob/master/virtio-scmi.tex > [2] https://www.oasis-open.org/committees/ballot.php?id=3496 > > Cc: "Michael S. Tsirkin" <[email protected]> > Cc: Jason Wang <[email protected]> > Signed-off-by: Igor Skalkin <[email protected]> > [ Peter: Adapted patch for submission to upstream. ] > Co-developed-by: Peter Hilber <[email protected]> > Signed-off-by: Peter Hilber <[email protected]> > [ Cristian: simplified driver logic, changed link_supplier and channel > available/setup logic, removed dummy callbacks ] > Co-developed-by: Cristian Marussi <[email protected]> > Signed-off-by: Cristian Marussi <[email protected]> > --- > NOTE THAT VIRTIO TRANSPORT IS ADDED AS default=n > > V6 --> V7 > - renamed desc init/exit to transport_init/exit > - reviewed Kconfig option to fit V7 ARM_SCMI Kconfig > > V5 --> V6 > - removed usage of delegated xfers > - using new scmi_rx_callback with priv argument > - removed .dummy clear_channel/.poll_done callbacks > - added missing spinlock comments > - updated Copyrights > > V4 --> V5 > - adapted Virtio transport config to new SCMI Kconfig layout > - removed support for polling > - added validate virtio method support > - removed usage of raw_payload helpers > - removed dynamic search of matching devices > - added one single statically configured device > > V3 --> V4 > - using delegated xfers > - using raw_payload msg helpers > --- > MAINTAINERS | 1 + > drivers/firmware/arm_scmi/Kconfig | 11 + > 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 | 491 +++++++++++++++++++++++++++++ > include/uapi/linux/virtio_ids.h | 1 + > include/uapi/linux/virtio_scmi.h | 24 ++ > 8 files changed, 535 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 a61f4f3b78a9..db1c7b74642e 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -17940,6 +17940,7 @@ 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
For all virtio bits please include L: [email protected] as well. Thanks! > > SYSTEM RESET/SHUTDOWN DRIVERS > M: Sebastian Reichel <[email protected]> > diff --git a/drivers/firmware/arm_scmi/Kconfig > b/drivers/firmware/arm_scmi/Kconfig > index 24fed705b02c..7f4d2435503b 100644 > --- a/drivers/firmware/arm_scmi/Kconfig > +++ b/drivers/firmware/arm_scmi/Kconfig > @@ -66,6 +66,17 @@ config ARM_SCMI_TRANSPORT_SMC > If you want the ARM SCMI PROTOCOL stack to include support for a > transport based on SMC, answer Y. > > +config ARM_SCMI_TRANSPORT_VIRTIO > + bool "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. > + > endif #ARM_SCMI_PROTOCOL > > config ARM_SCMI_POWER_DOMAIN > diff --git a/drivers/firmware/arm_scmi/Makefile > b/drivers/firmware/arm_scmi/Makefile > index aaad9f6589aa..1dcf123d64ab 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_ARM_SCMI_TRANSPORT_MAILBOX) += mailbox.o > scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) += smc.o > scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) += msg.o > +scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO) += 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 7864c21269b0..dea1bfbe1052 100644 > --- a/drivers/firmware/arm_scmi/common.h > +++ b/drivers/firmware/arm_scmi/common.h > @@ -418,6 +418,9 @@ extern const struct scmi_desc scmi_mailbox_desc; > #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC > extern const struct scmi_desc scmi_smc_desc; > #endif > +#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO > +extern const struct scmi_desc scmi_virtio_desc; > +#endif > > void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv); > void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int > id); > diff --git a/drivers/firmware/arm_scmi/driver.c > b/drivers/firmware/arm_scmi/driver.c > index aaca01a4d752..00fcacd06562 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -1983,6 +1983,9 @@ static const struct of_device_id scmi_of_match[] = { > #endif > #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC > { .compatible = "arm,scmi-smc", .data = &scmi_smc_desc}, > +#endif > +#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO > + { .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..3dacf794b177 > --- /dev/null > +++ b/drivers/firmware/arm_scmi/virtio.c > @@ -0,0 +1,491 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Virtio Transport driver for Arm System Control and Management Interface > + * (SCMI). > + * > + * Copyright (C) 2020-2021 OpenSynergy. > + * Copyright (C) 2021 ARM Ltd. > + */ > + > +/** > + * 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/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 > + * > + * @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 > + * @max_msg: Maximum number of pending messages for this channel. > + * @lock: Protects access to all members except ready. > + * @ready_lock: Protects access to ready. If required, it must be taken > before > + * lock. > + */ > +struct scmi_vio_channel { > + struct virtqueue *vqueue; > + struct scmi_chan_info *cinfo; > + struct list_head free_list; > + bool is_rx; > + bool ready; > + unsigned int max_msg; > + /* lock to protect access to all members except ready. */ > + spinlock_t lock; > + /* lock to rotects access to ready flag. */ > + spinlock_t ready_lock; > +}; > + > +/** > + * 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; > +}; > + > +/* Only one SCMI VirtIO device can possibly exist */ > +static struct virtio_device *scmi_vdev; > + > +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, > + "failed to add to virtqueue (%d)\n", rc); > + else > + virtqueue_kick(vioch->vqueue); > + > + spin_unlock_irqrestore(&vioch->lock, flags); > + > + return rc; > +} > + > +static void scmi_finalize_message(struct scmi_vio_channel *vioch, > + struct scmi_vio_msg *msg) > +{ > + if (vioch->is_rx) { > + scmi_vio_feed_vq_rx(vioch, msg); > + } else { > + unsigned long flags; > + > + spin_lock_irqsave(&vioch->lock, flags); > + list_add(&msg->list, &vioch->free_list); > + spin_unlock_irqrestore(&vioch->lock, flags); > + } > +} > + > +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); maybe take the lock out of the loop for speed? > + > + if (!vioch->ready) { > + if (!cb_enabled) > + (void)virtqueue_enable_cb(vqueue); > + goto unlock_ready_out; > + } > + > + spin_lock_irqsave(&vioch->lock, flags); no reason to re-save interrupts here - saved already ... > + 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; > + cb_enabled = true; > + } > + spin_unlock_irqrestore(&vioch->lock, flags); > + > + if (msg) { > + msg->rx_len = length; > + scmi_rx_callback(vioch->cinfo, > + msg_read_header(msg->input), msg); > + > + scmi_finalize_message(vioch, 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(struct scmi_chan_info *base_cinfo) > +{ > + struct scmi_vio_channel *vioch = base_cinfo->transport_info; > + > + return vioch->max_msg; > +} > + > +static int virtio_link_supplier(struct device *dev) > +{ > + if (!scmi_vdev) { > + dev_notice_once(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 *dev, int idx) > +{ > + struct scmi_vio_channel *channels, *vioch = NULL; > + > + if (WARN_ON_ONCE(!scmi_vdev)) > + return false; > + > + channels = (struct scmi_vio_channel *)scmi_vdev->priv; > + > + switch (idx) { > + case VIRTIO_SCMI_VQ_TX: > + vioch = &channels[VIRTIO_SCMI_VQ_TX]; > + break; > + case VIRTIO_SCMI_VQ_RX: > + if (scmi_vio_have_vq_rx(scmi_vdev)) > + vioch = &channels[VIRTIO_SCMI_VQ_RX]; > + break; > + default: > + return false; > + } > + > + return vioch && !vioch->cinfo ? true : false; > +} > + > +static int virtio_chan_setup(struct scmi_chan_info *cinfo, struct device > *dev, > + bool tx) > +{ > + unsigned long flags; > + struct scmi_vio_channel *vioch; > + int index = tx ? VIRTIO_SCMI_VQ_TX : VIRTIO_SCMI_VQ_RX; > + int i; > + > + if (!scmi_vdev) > + return -EPROBE_DEFER; > + > + vioch = &((struct scmi_vio_channel *)scmi_vdev->priv)[index]; > + > + for (i = 0; i < vioch->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->lock, flags); > + cinfo->transport_info = vioch; > + /* Indirectly setting channel not available any more */ > + vioch->cinfo = cinfo; > + spin_unlock_irqrestore(&vioch->lock, flags); > + > + 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); > + > + spin_lock_irqsave(&vioch->lock, flags); > + vioch->cinfo = NULL; > + spin_unlock_irqrestore(&vioch->lock, flags); > + > + 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; > + > + 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, why are all of these warnings once? There'll never be too many of these and it can make debugging harder. > + "%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) > +{ > + struct scmi_vio_msg *msg = xfer->priv; > + > + if (msg) { > + msg_fetch_response(msg->input, msg->rx_len, xfer); > + xfer->priv = NULL; > + } > +} > + > +static void virtio_fetch_notification(struct scmi_chan_info *cinfo, > + size_t max_len, struct scmi_xfer *xfer) > +{ > + struct scmi_vio_msg *msg = xfer->priv; > + > + if (msg) { > + msg_fetch_notification(msg->input, msg->rx_len, max_len, xfer); > + xfer->priv = NULL; > + } > +} > + > +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, > +}; > + > +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]; > + > + /* Only one SCMI VirtiO device allowed */ > + if (scmi_vdev) > + return -EINVAL; Or EBUSY maybe? And print an error message pls so users can figure out what is going on. > + > + 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); And free allocated memory here? > + return ret; > + } > + > + for (i = 0; i < vq_cnt; i++) { > + unsigned int sz; > + > + 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]; > + > + sz = virtqueue_get_vring_size(channels[i].vqueue); > + /* Tx messages need multiple descriptors. */ > + if (!channels[i].is_rx) > + sz /= DESCRIPTORS_PER_TX_MSG; > + > + if (sz > MSG_TOKEN_MAX) { > + dev_info_once(dev, > + "%s virtqueue could hold %d messages. > Only %ld allowed to be pending.\n", > + channels[i].is_rx ? "rx" : "tx", > + sz, MSG_TOKEN_MAX); > + sz = MSG_TOKEN_MAX; > + } > + channels[i].max_msg = sz; What happens if sz is too small here? E.g. 0? Should we fail probe? > + } > + > + vdev->priv = channels; > + scmi_vdev = vdev; So this is read in parallel, unless there's a lock I think you need an smp_wmb here and WRITE_ONCE. Or maybe add locking instead so we do not worry about ordering ... > + > + return 0; > +} > + > +static void scmi_vio_remove(struct virtio_device *vdev) > +{ > + vdev->config->reset(vdev); This will stop processing buffers immediately. You generally need to do something about outstanding buffers though. > + vdev->config->del_vqs(vdev); > + scmi_vdev = NULL; Well doing this here does not prevent some users being outstanding. I.e. I see device_link_add above but we should do device_link_del somewhere ... > +} > + > +static int scmi_vio_validate(struct virtio_device *vdev) > +{ > + if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { > + dev_err(&vdev->dev, > + "device does not comply with spec version 1.x\n"); > + return -EINVAL; > + } > + > + 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, > + .remove = scmi_vio_remove, > + .validate = scmi_vio_validate, > +}; > + > +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 = { > + .transport_init = virtio_scmi_init, > + .transport_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 70a8057ad4bb..f74155f6882d 100644 > --- a/include/uapi/linux/virtio_ids.h > +++ b/include/uapi/linux/virtio_ids.h > @@ -55,6 +55,7 @@ > #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 */ > #define VIRTIO_ID_BT 40 /* virtio bluetooth */ > > /* > diff --git a/include/uapi/linux/virtio_scmi.h > b/include/uapi/linux/virtio_scmi.h > new file mode 100644 > index 000000000000..f8ddd04a3ace > --- /dev/null > +++ b/include/uapi/linux/virtio_scmi.h > @@ -0,0 +1,24 @@ > +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR > BSD-3-Clause) */ > +/* > + * Copyright (C) 2020-2021 OpenSynergy GmbH > + * Copyright (C) 2021 ARM Ltd. > + */ > + > +#ifndef _UAPI_LINUX_VIRTIO_SCMI_H > +#define _UAPI_LINUX_VIRTIO_SCMI_H > + > +#include <linux/virtio_types.h> > + > +/* 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 */ > -- > 2.17.1 > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
