From: Alexandre Courbot <[email protected]> Add V4L2 buffer queue state tracking, streaming ioctls, asynchronous event virtqueue processing, V4L2 event subscription, and poll support.
Set up the event virtqueue to receive VIRTIO_MEDIA_EVT_DQBUF, VIRTIO_MEDIA_EVT_EVENT, and VIRTIO_MEDIA_EVT_ERROR notifications from the host, dispatching dequeued buffers, V4L2 events, and unrecoverable session errors to their respective sessions. Implement buffer and streaming ioctls (VIDIOC_REQBUFS, VIDIOC_CREATE_BUFS, VIDIOC_QUERYBUF, VIDIOC_PREPARE_BUF, VIDIOC_QBUF, VIDIOC_DQBUF, VIDIOC_STREAMON, VIDIOC_STREAMOFF, and VIDIOC_DECODER_CMD) as well as VIDIOC_SUBSCRIBE_EVENT, VIDIOC_UNSUBSCRIBE_EVENT, and the poll file operation. Signed-off-by: Alexandre Courbot <[email protected]> Assisted-by: LLM Co-developed-by: Brian Daniels <[email protected]> Signed-off-by: Brian Daniels <[email protected]> --- drivers/media/virtio/scatterlist_builder.c | 72 +++ drivers/media/virtio/scatterlist_builder.h | 8 + drivers/media/virtio/session.h | 51 ++ drivers/media/virtio/virtio_media.h | 11 + drivers/media/virtio/virtio_media_driver.c | 376 ++++++++++++- drivers/media/virtio/virtio_media_ioctls.c | 618 ++++++++++++++++++++- include/uapi/linux/virtio_media.h | 68 +++ 7 files changed, 1199 insertions(+), 5 deletions(-) diff --git a/drivers/media/virtio/scatterlist_builder.c b/drivers/media/virtio/scatterlist_builder.c index 3615f45e1..9be968ed8 100644 --- a/drivers/media/virtio/scatterlist_builder.c +++ b/drivers/media/virtio/scatterlist_builder.c @@ -355,6 +355,78 @@ static int scatterlist_builder_add_userptr(struct scatterlist_builder *builder, return 0; } +/** + * scatterlist_builder_add_buffer() - Add a &struct v4l2_buffer and its planes + * to the descriptor chain. + * @builder: builder to use. + * @b: &struct v4l2_buffer to add. + */ +int scatterlist_builder_add_buffer(struct scatterlist_builder *builder, + struct v4l2_buffer *b) +{ + int ret; + + /* v4l2_buffer */ + ret = scatterlist_builder_add_data(builder, b, sizeof(*b)); + if (ret) + return ret; + + if (V4L2_TYPE_IS_MULTIPLANAR(b->type) && b->length > 0) { + /* Array of v4l2_planes */ + ret = scatterlist_builder_add_data(builder, b->m.planes, + sizeof(struct v4l2_plane) * + b->length); + if (ret) + return ret; + } + + return 0; +} + +/** + * scatterlist_builder_retrieve_buffer() - Retrieve a &struct v4l2_buffer + * written by the device on the shadow + * buffer, if needed. + * @builder: builder to use. + * @sg_index: index of the first SG entry of the buffer in the builder's + * descriptor chain. + * @b: &struct v4l2_buffer to copy shadow buffer data into. + * @orig_planes: the original ``planes`` pointer, to be restored if the buffer + * is multi-planar. + * + * If the &struct v4l2_buffer pointed to by @sg_index was copied into the + * shadow buffer, then its updated content is copied back into @b. + * Otherwise nothing is done as the device has written into @b directly. + * + * @orig_planes is used to restore the original ``planes`` pointer in case it + * gets modified by the host. The specification stipulates that the host should + * not modify it, but we enforce this for additional safety. + */ +int scatterlist_builder_retrieve_buffer(struct scatterlist_builder *builder, + size_t sg_index, struct v4l2_buffer *b, + struct v4l2_plane *orig_planes) +{ + int ret; + + ret = scatterlist_builder_retrieve_data(builder, sg_index++, b); + if (ret) + return ret; + + if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { + b->m.planes = orig_planes; + + if (orig_planes) { + ret = scatterlist_builder_retrieve_data(builder, + sg_index++, + b->m.planes); + if (ret) + return ret; + } + } + + return 0; +} + /** * scatterlist_builder_add_ext_ctrls() - Add a &struct v4l2_ext_controls and its * controls to @builder. diff --git a/drivers/media/virtio/scatterlist_builder.h b/drivers/media/virtio/scatterlist_builder.h index 79d53f602..6a3c7ce44 100644 --- a/drivers/media/virtio/scatterlist_builder.h +++ b/drivers/media/virtio/scatterlist_builder.h @@ -91,6 +91,14 @@ int scatterlist_builder_add_ioctl_cmd(struct scatterlist_builder *builder, int scatterlist_builder_add_ioctl_resp(struct scatterlist_builder *builder, struct virtio_media_session *session); +int scatterlist_builder_add_buffer(struct scatterlist_builder *builder, + struct v4l2_buffer *buffer); + +int scatterlist_builder_retrieve_buffer(struct scatterlist_builder *builder, + size_t sg_index, + struct v4l2_buffer *buffer, + struct v4l2_plane *orig_planes); + int scatterlist_builder_add_ext_ctrls(struct scatterlist_builder *builder, struct v4l2_ext_controls *ctrls); diff --git a/drivers/media/virtio/session.h b/drivers/media/virtio/session.h index 6fe7ff5ae..16bb86bf4 100644 --- a/drivers/media/virtio/session.h +++ b/drivers/media/virtio/session.h @@ -14,17 +14,55 @@ #include "uapi/linux/virtio_media.h" +#define VIRTIO_MEDIA_LAST_QUEUE (V4L2_BUF_TYPE_META_OUTPUT) + /* * Size of the per-session virtio shadow and event buffers. 16K should be * enough to contain everything we need. */ #define VIRTIO_SHADOW_BUF_SIZE 0x4000 +/** + * struct virtio_media_buffer - Current state of a buffer. + * @buffer: &struct v4l2_buffer with current information about the buffer. + * @planes: backing planes array for @buffer. + * @list: link into the list of buffers pending dequeue. + */ +struct virtio_media_buffer { + struct v4l2_buffer buffer; + struct v4l2_plane planes[VIDEO_MAX_PLANES]; + struct list_head list; +}; + +/** + * struct virtio_media_queue_state - Represents the state of a V4L2 queue. + * @streaming: Whether the queue is currently streaming. + * @allocated_bufs: How many buffers are currently allocated. + * @is_capture_last: set to true when the last buffer has been received on a + * capture queue, so we can return %-EPIPE on subsequent + * DQBUF requests. + * @buffers: Buffer state array of size @allocated_bufs. + * @queued_bufs: How many buffers are currently queued on the device. + * @pending_dqbufs: Buffers that are available for being dequeued. + */ +struct virtio_media_queue_state { + bool streaming; + size_t allocated_bufs; + bool is_capture_last; + + struct virtio_media_buffer *buffers; + size_t queued_bufs; + struct list_head pending_dqbufs; +}; + /** * struct virtio_media_session - A session on a virtio_media device. * @fh: file handler for the session. * @file: file pointer associated with the session's file handler. * @id: session ID used to communicate with the device. + * @nonblocking_dequeue: whether dequeue should block or not (nonblocking if + * file opened with O_NONBLOCK). + * @uses_mplane: whether the queues for this session use the MPLANE API or not. * @cmd: union of session commands ``close`` and ``ioctl``. A session can have * one command currently running. The rest of the commands are handled by * &struct virtio_media. @@ -35,12 +73,19 @@ * be staged before being sent to the device. * @command_sgs: SG table gathering descriptors for a given command and its * response. + * @queues: state of all the queues for this session. + * @queues_lock: protects all members for the queues for this session. + * @dqbuf_wait: waitqueue for dequeued buffers, if ``VIDIOC_DQBUF`` needs to + * block or when polling. + * @error: true if the session has encountered an unrecoverable session error. * @list: link into the list of sessions for the device. */ struct virtio_media_session { struct v4l2_fh fh; struct file *file; u32 id; + bool nonblocking_dequeue; + bool uses_mplane; __dma_from_device_group_begin(); union { @@ -57,6 +102,12 @@ struct virtio_media_session { struct sg_table command_sgs; + struct virtio_media_queue_state queues[VIRTIO_MEDIA_LAST_QUEUE + 1]; + struct mutex queues_lock; /* protects queues array and states */ + wait_queue_head_t dqbuf_wait; + bool error; + struct mutex error_lock; /* protects error */ + struct list_head list; }; diff --git a/drivers/media/virtio/virtio_media.h b/drivers/media/virtio/virtio_media.h index a120c1014..8b21c1941 100644 --- a/drivers/media/virtio/virtio_media.h +++ b/drivers/media/virtio/virtio_media.h @@ -24,8 +24,12 @@ * @video_dev: video_device for the media device. * @virtio_dev: virtio device for the media device. * @commandq: virtio command queue. + * @eventq: virtio event queue. + * @eventq_work: work to run when events are received on @eventq. + * @event_buffer: buffer for event descriptors. * @sessions: list of active sessions on the device. * @sessions_lock: protects @sessions and &struct virtio_media_session.list. + * @events_lock: prevents concurrent processing of events. * @cmd: union of device-level commands. Session commands are handled by * &struct virtio_media_session. * @resp: union of responses to device-level commands. Session responses are @@ -39,10 +43,16 @@ struct virtio_media { struct virtio_device *virtio_dev; struct virtqueue *commandq; + struct virtqueue *eventq; + struct work_struct eventq_work; + + void *event_buffer; struct list_head sessions; struct mutex sessions_lock; /* protects sessions list */ + struct mutex events_lock; /* prevents concurrent event processing */ + __dma_from_device_group_begin(); union { struct virtio_media_cmd_open open; @@ -68,6 +78,7 @@ to_virtio_media(struct video_device *video_dev) int virtio_media_send_command(struct virtio_media *vv, struct scatterlist **sgs, const size_t out_sgs, const size_t in_sgs, size_t minimum_resp_len, size_t *resp_len); +void virtio_media_process_events(struct virtio_media *vv); /* virtio_media_ioctls.c */ diff --git a/drivers/media/virtio/virtio_media_driver.c b/drivers/media/virtio/virtio_media_driver.c index 2f2e95077..877ac154b 100644 --- a/drivers/media/virtio/virtio_media_driver.c +++ b/drivers/media/virtio/virtio_media_driver.c @@ -16,15 +16,22 @@ #include <linux/virtio_ids.h> #include <linux/slab.h> #include <linux/scatterlist.h> +#include <linux/vmalloc.h> +#include <linux/workqueue.h> +#include <linux/dma-mapping.h> +#include <linux/poll.h> #include <media/v4l2-dev.h> #include <media/v4l2-device.h> #include <media/v4l2-fh.h> +#include <media/v4l2-event.h> #include "uapi/linux/virtio_media.h" #include "session.h" #include "virtio_media.h" +#define VIRTIO_MEDIA_NUM_EVENT_BUFS 16 + /** * virtio_media_session_alloc() - Allocate a new session. * @vv: virtio-media device the session belongs to. @@ -37,6 +44,7 @@ static struct virtio_media_session * virtio_media_session_alloc(struct virtio_media *vv, struct file *file) { struct virtio_media_session *session; + int i; int ret; session = kzalloc_obj(*session, GFP_KERNEL); @@ -54,11 +62,20 @@ virtio_media_session_alloc(struct virtio_media *vv, struct file *file) // The caller is expected to set the ID once the host assigns a value. session->id = 0; + session->nonblocking_dequeue = file->f_flags & O_NONBLOCK; INIT_LIST_HEAD(&session->list); v4l2_fh_init(&session->fh, &vv->video_dev); virtio_media_session_fh_add(session, file); + for (i = 0; i <= VIRTIO_MEDIA_LAST_QUEUE; i++) + INIT_LIST_HEAD(&session->queues[i].pending_dqbufs); + mutex_init(&session->queues_lock); + + init_waitqueue_head(&session->dqbuf_wait); + + mutex_init(&session->error_lock); + return session; err_payload_sgs: @@ -91,11 +108,16 @@ static void virtio_media_session_add(struct virtio_media *vv, */ static void virtio_media_session_free(struct virtio_media_session *session) { + int i; + virtio_media_session_fh_del(session); v4l2_fh_exit(&session->fh); sg_free_table(&session->command_sgs); + for (i = 0; i <= VIRTIO_MEDIA_LAST_QUEUE; i++) + vfree(session->queues[i].buffers); + kfree(session->shadow_buf); kfree(session); } @@ -152,6 +174,31 @@ static int virtio_media_session_close(struct virtio_media *vv, return 0; } +/** + * virtio_media_find_session() - Look up a session with a given ID. + * @vv: virtio-media device to lookup the session from. + * @id: ID of the session to lookup. + */ +static struct virtio_media_session * +virtio_media_find_session(struct virtio_media *vv, u32 id) +{ + struct list_head *p; + struct virtio_media_session *session = NULL; + + mutex_lock(&vv->sessions_lock); + list_for_each(p, &vv->sessions) { + struct virtio_media_session *s = + list_entry(p, struct virtio_media_session, list); + if (s->id == id) { + session = s; + break; + } + } + mutex_unlock(&vv->sessions_lock); + + return session; +} + /** * struct virtio_media_cmd_callback_param - Callback parameters to the virtio * command queue. @@ -290,6 +337,234 @@ int virtio_media_send_command(struct virtio_media *vv, struct scatterlist **sgs, return 0; } +/** + * virtio_media_send_event_buffer() - Sends an event buffer to the host so it + * can return it with an event. + * @vv: virtio-media device in use. + * @event_buffer: pointer to the event buffer to send to the device. + */ +static int virtio_media_send_event_buffer(struct virtio_media *vv, + void *event_buffer) +{ + struct scatterlist *sgs[1], vresp; + int ret; + + sg_init_one(&vresp, event_buffer, VIRTIO_MEDIA_EVENT_MAX_SIZE); + sgs[0] = &vresp; + + ret = virtqueue_add_sgs(vv->eventq, sgs, 0, 1, event_buffer, + GFP_ATOMIC); + if (ret) { + v4l2_err(&vv->v4l2_dev, + "failed to add sgs to event virtqueue\n"); + return ret; + } + + if (!virtqueue_kick(vv->eventq)) { + v4l2_err(&vv->v4l2_dev, "failed to kick event virtqueue\n"); + return -EINVAL; + } + + return 0; +} + +/** + * eventq_callback() - Callback for the event queue. + * @queue: event virtqueue. + * + * This just schedules for event work to be run. + */ +static void eventq_callback(struct virtqueue *queue) +{ + struct virtio_media *vv = queue->vdev->priv; + + schedule_work(&vv->eventq_work); +} + +/** + * virtio_media_process_dqbuf_event() - Process a dequeued event for a session. + * @vv: virtio-media device in use. + * @session: session the event is addressed to. + * @dqbuf_evt: the dequeued event to process. + * + * Invalid events are ignored with an error log. + */ +static void +virtio_media_process_dqbuf_event(struct virtio_media *vv, + struct virtio_media_session *session, + struct virtio_media_event_dqbuf *dqbuf_evt) +{ + struct virtio_media_buffer *dqbuf; + const enum v4l2_buf_type queue_type = dqbuf_evt->buffer.type; + struct virtio_media_queue_state *queue; + typeof(dqbuf->buffer.m) buffer_m; + typeof(dqbuf->buffer.m.planes[0].m) plane_m; + int i; + + if (queue_type >= ARRAY_SIZE(session->queues)) { + v4l2_err(&vv->v4l2_dev, + "unmanaged queue %d passed to dqbuf event", + dqbuf_evt->buffer.type); + return; + } + queue = &session->queues[queue_type]; + + if (dqbuf_evt->buffer.index >= queue->allocated_bufs) { + v4l2_err(&vv->v4l2_dev, + "invalid buffer ID %d for queue %d in dqbuf event", + dqbuf_evt->buffer.index, dqbuf_evt->buffer.type); + return; + } + + dqbuf = &queue->buffers[dqbuf_evt->buffer.index]; + + /* + * Preserve the 'm' union that was passed to us during QBUF so userspace + * gets back the information it submitted. + */ + buffer_m = dqbuf->buffer.m; + memcpy(&dqbuf->buffer, &dqbuf_evt->buffer, sizeof(dqbuf->buffer)); + dqbuf->buffer.m = buffer_m; + if (V4L2_TYPE_IS_MULTIPLANAR(dqbuf->buffer.type)) { + if (dqbuf->buffer.length > VIDEO_MAX_PLANES) { + v4l2_err(&vv->v4l2_dev, + "invalid number of planes received from host for a multiplanar buffer\n"); + return; + } + for (i = 0; i < dqbuf->buffer.length; i++) { + plane_m = dqbuf->planes[i].m; + memcpy(&dqbuf->planes[i], &dqbuf_evt->planes[i], + sizeof(struct v4l2_plane)); + dqbuf->planes[i].m = plane_m; + } + } + + /* Set the DONE flag as the buffer is waiting to be dequeued. */ + dqbuf->buffer.flags |= V4L2_BUF_FLAG_DONE; + + mutex_lock(&session->queues_lock); + list_add_tail(&dqbuf->list, &queue->pending_dqbufs); + queue->queued_bufs -= 1; + mutex_unlock(&session->queues_lock); + + wake_up(&session->dqbuf_wait); +} + +/** + * virtio_media_process_events() - Process all pending events on a device. + * @vv: device whose pending events we want to process. + * + * Retrieves all pending events on @vv's event queue and dispatches them to + * their corresponding session. + * + * Invalid events are ignored with an error log. + */ +void virtio_media_process_events(struct virtio_media *vv) +{ + struct virtio_media_event_error *error_evt; + struct virtio_media_event_dqbuf *dqbuf_evt; + struct virtio_media_event_event *event_evt; + struct virtio_media_session *session; + struct virtio_media_event_header *evt; + unsigned int len; + + mutex_lock(&vv->events_lock); + +process_bufs: + while ((evt = virtqueue_get_buf(vv->eventq, &len))) { + /* Make sure we received enough data */ + if (len < sizeof(*evt)) { + v4l2_err(&vv->v4l2_dev, + "event is too short: got %u, expected at least %zu\n", + len, sizeof(*evt)); + goto end_of_event; + } + + session = virtio_media_find_session(vv, evt->session_id); + if (!session) { + v4l2_err(&vv->v4l2_dev, "cannot find session %d\n", + evt->session_id); + goto end_of_event; + } + + switch (evt->event) { + case VIRTIO_MEDIA_EVT_ERROR: + if (len < sizeof(*error_evt)) { + v4l2_err(&vv->v4l2_dev, + "error event is too short: got %u, expected %zu\n", + len, sizeof(*error_evt)); + break; + } + error_evt = (struct virtio_media_event_error *)evt; + v4l2_err(&vv->v4l2_dev, + "received error %d for session %d", + error_evt->error, error_evt->hdr.session_id); + + mutex_lock(&session->error_lock); + session->error = true; + mutex_unlock(&session->error_lock); + + virtio_media_session_close(vv, session); + + /* Wake up any waiting dqbuf requests */ + wake_up(&session->dqbuf_wait); + + break; + + /* + * Dequeued buffer: put it into the right queue so user-space + * can dequeue it. + */ + case VIRTIO_MEDIA_EVT_DQBUF: + if (len < sizeof(*dqbuf_evt)) { + v4l2_err(&vv->v4l2_dev, + "dqbuf event is too short: got %u, expected %zu\n", + len, sizeof(*dqbuf_evt)); + break; + } + dqbuf_evt = (struct virtio_media_event_dqbuf *)evt; + virtio_media_process_dqbuf_event(vv, session, + dqbuf_evt); + break; + + case VIRTIO_MEDIA_EVT_EVENT: + if (len < sizeof(*event_evt)) { + v4l2_err(&vv->v4l2_dev, + "session event is too short: got %u expected %zu\n", + len, sizeof(*event_evt)); + break; + } + + event_evt = (struct virtio_media_event_event *)evt; + v4l2_event_queue_fh(&session->fh, &event_evt->event); + break; + + default: + v4l2_err(&vv->v4l2_dev, "unknown event type %d\n", + evt->event); + break; + } + +end_of_event: + virtio_media_send_event_buffer(vv, evt); + } + + if (!virtqueue_enable_cb(vv->eventq)) { + virtqueue_disable_cb(vv->eventq); + goto process_bufs; + } + + mutex_unlock(&vv->events_lock); +} + +static void virtio_media_event_work(struct work_struct *work) +{ + struct virtio_media *vv = + container_of(work, struct virtio_media, eventq_work); + + virtio_media_process_events(vv); +} + /** * virtio_media_device_open() - Create a new session from an opened file. * @file: opened file for the session. @@ -358,10 +633,65 @@ static int virtio_media_device_close(struct file *file) return ret; } +/** + * virtio_media_device_poll() - Poll logic for a virtio-media device. + * @file: file of the session to poll. + * @wait: poll table to wait on. + */ +static __poll_t virtio_media_device_poll(struct file *file, poll_table *wait) +{ + struct virtio_media_session *session = + fh_to_session(file->private_data); + enum v4l2_buf_type capture_type = + session->uses_mplane ? V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE : + V4L2_BUF_TYPE_VIDEO_CAPTURE; + enum v4l2_buf_type output_type = + session->uses_mplane ? V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE : + V4L2_BUF_TYPE_VIDEO_OUTPUT; + struct virtio_media_queue_state *capture_queue = + &session->queues[capture_type]; + struct virtio_media_queue_state *output_queue = + &session->queues[output_type]; + __poll_t req_events = poll_requested_events(wait); + __poll_t rc = 0; + + poll_wait(file, &session->dqbuf_wait, wait); + poll_wait(file, &session->fh.wait, wait); + + mutex_lock(&session->error_lock); + if (session->error) + rc |= EPOLLERR; + mutex_unlock(&session->error_lock); + + mutex_lock(&session->queues_lock); + if (req_events & (EPOLLIN | EPOLLRDNORM)) { + if (!capture_queue->streaming || + (capture_queue->queued_bufs == 0 && + list_empty(&capture_queue->pending_dqbufs))) + rc |= EPOLLERR; + else if (!list_empty(&capture_queue->pending_dqbufs)) + rc |= EPOLLIN | EPOLLRDNORM; + } + if (req_events & (EPOLLOUT | EPOLLWRNORM)) { + if (!output_queue->streaming) + rc |= EPOLLERR; + else if (output_queue->queued_bufs < + output_queue->allocated_bufs) + rc |= EPOLLOUT | EPOLLWRNORM; + } + mutex_unlock(&session->queues_lock); + + if (v4l2_event_pending(&session->fh)) + rc |= EPOLLPRI; + + return rc; +} + static const struct v4l2_file_operations virtio_media_fops = { .owner = THIS_MODULE, .open = virtio_media_device_open, .release = virtio_media_device_close, + .poll = virtio_media_device_poll, .unlocked_ioctl = virtio_media_device_ioctl, }; @@ -371,29 +701,47 @@ static void virtio_media_release(struct v4l2_device *v4l2_dev) container_of(v4l2_dev, struct virtio_media, v4l2_dev); v4l2_device_unregister(&vv->v4l2_dev); + kfree(vv->event_buffer); kfree(vv); } static int virtio_media_probe(struct virtio_device *virtio_dev) { struct device *dev = &virtio_dev->dev; - struct virtqueue *vqs[1]; - static struct virtqueue_info vq_info[1] = { + struct virtqueue *vqs[2]; + static struct virtqueue_info vq_info[2] = { { .name = "command", .callback = commandq_callback, }, + { + .name = "event", + .callback = eventq_callback, + }, }; struct virtio_media *vv; struct video_device *vd; + int i; int ret; vv = kzalloc_obj(struct virtio_media); if (!vv) return -ENOMEM; + const size_t virtio_media_event_aligned_size = + ALIGN(VIRTIO_MEDIA_EVENT_MAX_SIZE, dma_get_cache_alignment()); + + vv->event_buffer = kzalloc(virtio_media_event_aligned_size * + VIRTIO_MEDIA_NUM_EVENT_BUFS, + GFP_KERNEL); + if (!vv->event_buffer) { + ret = -ENOMEM; + goto err_free_virtio_media; + } + INIT_LIST_HEAD(&vv->sessions); mutex_init(&vv->sessions_lock); + mutex_init(&vv->events_lock); mutex_init(&vv->vlock); vv->virtio_dev = virtio_dev; @@ -403,15 +751,17 @@ static int virtio_media_probe(struct virtio_device *virtio_dev) ret = v4l2_device_register(dev, &vv->v4l2_dev); if (ret) - goto err_free_virtio_media; + goto err_free_event_buffer; vv->v4l2_dev.release = virtio_media_release; - ret = virtio_find_vqs(virtio_dev, 1, vqs, vq_info, NULL); + ret = virtio_find_vqs(virtio_dev, 2, vqs, vq_info, NULL); if (ret) goto err_v4l2_device_unregister; vv->commandq = vqs[0]; + vv->eventq = vqs[1]; + INIT_WORK(&vv->eventq_work, virtio_media_event_work); vd = &vv->video_dev; vd->v4l2_dev = &vv->v4l2_dev; @@ -449,12 +799,25 @@ static int virtio_media_probe(struct virtio_device *virtio_dev) if (ret) goto err_del_vqs; + for (i = 0; i < VIRTIO_MEDIA_NUM_EVENT_BUFS; i++) { + void *ebuf = vv->event_buffer + + virtio_media_event_aligned_size * i; + + ret = virtio_media_send_event_buffer(vv, ebuf); + if (ret) + goto err_video_unregister_device; + } + return 0; +err_video_unregister_device: + video_unregister_device(&vv->video_dev); err_del_vqs: virtio_dev->config->del_vqs(virtio_dev); err_v4l2_device_unregister: v4l2_device_unregister(&vv->v4l2_dev); +err_free_event_buffer: + kfree(vv->event_buffer); err_free_virtio_media: kfree(vv); return ret; @@ -468,6 +831,9 @@ static void virtio_media_remove(struct virtio_device *virtio_dev) /* Remove the video device to stop accessing the commandq virtqueue */ video_unregister_device(&vv->video_dev); + /* Stop event handling work queue from accessing eventq virtqueue */ + cancel_work_sync(&vv->eventq_work); + /* * Acquire vlock to ensure no concurrent accesses to the commandq * virtqueue @@ -483,6 +849,8 @@ static void virtio_media_remove(struct virtio_device *virtio_dev) */ while (virtqueue_detach_unused_buf(vv->commandq)) ; + while (virtqueue_detach_unused_buf(vv->eventq)) + ; /* Delete the virtqueues */ virtio_dev->config->del_vqs(virtio_dev); diff --git a/drivers/media/virtio/virtio_media_ioctls.c b/drivers/media/virtio/virtio_media_ioctls.c index 51f46b334..9bf283469 100644 --- a/drivers/media/virtio/virtio_media_ioctls.c +++ b/drivers/media/virtio/virtio_media_ioctls.c @@ -9,6 +9,8 @@ #include <linux/mutex.h> #include <linux/videodev2.h> #include <linux/virtio_config.h> +#include <linux/vmalloc.h> +#include <media/v4l2-event.h> #include <media/v4l2-ioctl.h> #include "scatterlist_builder.h" @@ -218,6 +220,101 @@ static int virtio_media_send_wr_ioctl(struct v4l2_fh *fh, u32 ioctl, return 0; } +/** + * virtio_media_send_buffer_ioctl() - Send an ioctl taking a buffer as + * parameter to the device. + * @fh: file handler of the session doing the ioctl. + * @ioctl: ``VIDIOC_*`` ioctl code. + * @b: &struct v4l2_buffer to be sent as the ioctl payload. + * + * Buffers can require an additional descriptor to send their planes array, and + * can have pointers to userspace memory hence this dedicated function. + */ +static int virtio_media_send_buffer_ioctl(struct v4l2_fh *fh, u32 ioctl, + struct v4l2_buffer *b) +{ + struct video_device *video_dev = fh->vdev; + struct virtio_media *vv = to_virtio_media(video_dev); + struct virtio_media_session *session = fh_to_session(fh); + struct v4l2_plane *orig_planes = NULL; + struct scatterlist *sgs[64]; + /* + * End of the device-readable buffer SGs, to reuse in device-writable + * section. + */ + size_t num_cmd_sgs; + size_t end_buf_sg; + struct scatterlist_builder builder = { + .descs = session->command_sgs.sgl, + .num_descs = DESC_CHAIN_MAX_LEN, + .cur_desc = 0, + .shadow_buffer = session->shadow_buf, + .shadow_buffer_size = VIRTIO_SHADOW_BUF_SIZE, + .shadow_buffer_pos = 0, + .sgs = sgs, + .num_sgs = ARRAY_SIZE(sgs), + .cur_sg = 0, + .framevec = NULL, + }; + size_t resp_len; + int ret; + int i; + + if (b->type > VIRTIO_MEDIA_LAST_QUEUE) + return -EINVAL; + + if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) + orig_planes = b->m.planes; + + /* Command descriptor */ + ret = scatterlist_builder_add_ioctl_cmd(&builder, session, ioctl); + if (ret) + return ret; + + /* Command payload (struct v4l2_buffer) */ + ret = scatterlist_builder_add_buffer(&builder, b); + if (ret < 0) + return ret; + + end_buf_sg = builder.cur_sg; + num_cmd_sgs = builder.cur_sg; + + /* Response descriptor */ + ret = scatterlist_builder_add_ioctl_resp(&builder, session); + if (ret) + return ret; + + /* Response payload (same as input, but no userptr mapping) */ + for (i = 1; i < end_buf_sg; i++) { + ret = scatterlist_builder_add_descriptor(&builder, i); + if (ret < 0) + return ret; + } + + ret = virtio_media_send_command(vv, builder.sgs, num_cmd_sgs, + builder.cur_sg - num_cmd_sgs, + sizeof(struct virtio_media_resp_ioctl) + + sizeof(*b), &resp_len); + if (ret < 0) + return ret; + + resp_len -= sizeof(struct virtio_media_resp_ioctl); + + /* Make sure that the reply length covers our v4l2_buffer */ + if (resp_len < sizeof(*b)) + return -EINVAL; + + ret = scatterlist_builder_retrieve_buffer(&builder, num_cmd_sgs + 1, b, + orig_planes); + if (ret) { + v4l2_err(&vv->v4l2_dev, + "failed to retrieve response descriptor chain\n"); + return ret; + } + + return 0; +} + /** * virtio_media_send_ext_controls_ioctl() - Send an ioctl taking extended * controls as parameters to the device. @@ -336,6 +433,41 @@ static int virtio_media_send_ext_controls_ioctl(struct v4l2_fh *fh, u32 ioctl, return 0; } +/** + * virtio_media_clear_queue() - clear all pending buffers on a streamed-off + * queue. + * @session: session which the queue to clear belongs to. + * @queue: state of the queue to clear. + * + * Helper function to clear the list of buffers waiting to be dequeued on a + * queue that has just been streamed off. + */ +static void virtio_media_clear_queue(struct virtio_media_session *session, + struct virtio_media_queue_state *queue) +{ + struct list_head *p, *n; + int i; + + mutex_lock(&session->queues_lock); + + list_for_each_safe(p, n, &queue->pending_dqbufs) { + struct virtio_media_buffer *dqbuf = + list_entry(p, struct virtio_media_buffer, list); + + list_del(&dqbuf->list); + } + + /* All buffers are now dequeued. */ + for (i = 0; i < queue->allocated_bufs; i++) + queue->buffers[i].buffer.flags = 0; + + queue->queued_bufs = 0; + queue->streaming = false; + queue->is_capture_last = false; + + mutex_unlock(&session->queues_lock); +} + /* * Macros suitable for defining ioctls with a constant size payload. */ @@ -479,6 +611,431 @@ static int virtio_media_try_ext_ctrls(struct file *file, void *fh, ctrls); } +/* + * Subscribe/unsubscribe from an event. + */ + +static int +virtio_media_subscribe_event(struct v4l2_fh *fh, + const struct v4l2_event_subscription *sub) +{ + struct video_device *video_dev = fh->vdev; + struct virtio_media *vv = to_virtio_media(video_dev); + int ret; + + /* First subscribe to the event in the guest. */ + switch (sub->type) { + case V4L2_EVENT_SOURCE_CHANGE: + ret = v4l2_src_change_event_subscribe(fh, sub); + break; + default: + ret = v4l2_event_subscribe(fh, sub, 1, NULL); + break; + } + if (ret) + return ret; + + /* Then ask the host to signal us these events. */ + ret = virtio_media_send_w_ioctl(fh, VIDIOC_SUBSCRIBE_EVENT, sub, + sizeof(*sub)); + if (ret < 0) { + v4l2_event_unsubscribe(fh, sub); + return ret; + } + + /* + * Subscribing to an event may result in that event being signaled + * immediately. Process all pending events to make sure we don't + * miss it. + */ + if (sub->flags & V4L2_EVENT_SUB_FL_SEND_INITIAL) + virtio_media_process_events(vv); + + return 0; +} + +static int +virtio_media_unsubscribe_event(struct v4l2_fh *fh, + const struct v4l2_event_subscription *sub) +{ + int ret = virtio_media_send_w_ioctl(fh, VIDIOC_UNSUBSCRIBE_EVENT, sub, + sizeof(*sub)); + if (ret < 0) + return ret; + + ret = v4l2_event_unsubscribe(fh, sub); + if (ret) + return ret; + + return 0; +} + +/* + * Streamon/off affect the local queue state. + */ + +static int virtio_media_streamon(struct file *file, void *fh, + enum v4l2_buf_type i) +{ + struct v4l2_fh *vfh = file_to_v4l2_fh(file); + struct virtio_media_session *session = fh_to_session(vfh); + int ret; + + if (i > VIRTIO_MEDIA_LAST_QUEUE) + return -EINVAL; + + ret = virtio_media_send_w_ioctl(vfh, VIDIOC_STREAMON, &i, sizeof(i)); + if (ret < 0) + return ret; + + session->queues[i].streaming = true; + + return 0; +} + +static int virtio_media_streamoff(struct file *file, void *fh, + enum v4l2_buf_type i) +{ + struct v4l2_fh *vfh = file_to_v4l2_fh(file); + struct virtio_media_session *session = fh_to_session(vfh); + int ret; + + if (i > VIRTIO_MEDIA_LAST_QUEUE) + return -EINVAL; + + ret = virtio_media_send_w_ioctl(vfh, VIDIOC_STREAMOFF, &i, sizeof(i)); + if (ret < 0) + return ret; + + virtio_media_clear_queue(session, &session->queues[i]); + + return 0; +} + +/* + * Buffer creation/queuing functions deal with the local driver state. + */ + +static int virtio_media_reqbufs(struct file *file, void *fh, + struct v4l2_requestbuffers *b) +{ + struct v4l2_fh *vfh = file_to_v4l2_fh(file); + struct virtio_media_session *session = fh_to_session(vfh); + struct virtio_media_buffer *buffers = NULL; + struct virtio_media_queue_state *queue; + int ret; + + if (b->type > VIRTIO_MEDIA_LAST_QUEUE) + return -EINVAL; + + if (b->memory == V4L2_MEMORY_USERPTR) + return -EINVAL; + + if (b->count > 0) { + buffers = + vcalloc(b->count, sizeof(struct virtio_media_buffer)); + if (!buffers) + return -ENOMEM; + } + + ret = virtio_media_send_wr_ioctl(vfh, VIDIOC_REQBUFS, b, sizeof(*b), + sizeof(*b)); + if (ret) { + vfree(buffers); + return ret; + } + + queue = &session->queues[b->type]; + + /* REQBUFS(0) is an implicit STREAMOFF. */ + if (b->count == 0) + virtio_media_clear_queue(session, queue); + + vfree(queue->buffers); + queue->buffers = buffers; + + queue->allocated_bufs = b->count; + + /* + * If a multiplanar queue is successfully used here, this means + * we are using the multiplanar interface. + */ + if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) + session->uses_mplane = true; + + b->capabilities &= ~V4L2_BUF_CAP_SUPPORTS_USERPTR; + + /* We do not support DMABUF yet. */ + b->capabilities &= ~V4L2_BUF_CAP_SUPPORTS_DMABUF; + + return 0; +} + +static int virtio_media_querybuf(struct file *file, void *fh, + struct v4l2_buffer *b) +{ + struct v4l2_fh *vfh = file_to_v4l2_fh(file); + struct virtio_media_session *session = fh_to_session(vfh); + struct virtio_media_queue_state *queue; + struct virtio_media_buffer *buffer; + + int ret = virtio_media_send_buffer_ioctl(vfh, VIDIOC_QUERYBUF, b); + + if (ret) + return ret; + + if (b->type > VIRTIO_MEDIA_LAST_QUEUE) + return -EINVAL; + + queue = &session->queues[b->type]; + if (b->index >= queue->allocated_bufs) + return -EINVAL; + + buffer = &queue->buffers[b->index]; + /* + * Set the DONE flag if the buffer is waiting in our own dequeue + * queue. + */ + b->flags |= (buffer->buffer.flags & V4L2_BUF_FLAG_DONE); + + return 0; +} + +static int virtio_media_create_bufs(struct file *file, void *fh, + struct v4l2_create_buffers *b) +{ + struct v4l2_fh *vfh = file_to_v4l2_fh(file); + struct virtio_media_session *session = fh_to_session(vfh); + struct virtio_media_queue_state *queue; + struct virtio_media_buffer *buffers = NULL; + u32 type = b->format.type; + int ret; + + if (type > VIRTIO_MEDIA_LAST_QUEUE) + return -EINVAL; + + queue = &session->queues[type]; + + if (b->count > 0) { + /* + * This allocates a new buffer large enough for the existing + * buffers (``queue->allocated_bufs``) as well as the newly + * requested buffers (``b->count``). The host may allocate + * fewer buffers than requested, as indicated by the final + * value of ``b->count``. In this case, we do not re-allocate + * to avoid the case where this new allocation fails and the + * host buffers need to be freed. Instead we simply use the + * larger buffer. + */ + buffers = vcalloc(queue->allocated_bufs + b->count, + sizeof(*queue->buffers)); + if (!buffers) + return -ENOMEM; + } + + ret = virtio_media_send_wr_ioctl(vfh, VIDIOC_CREATE_BUFS, b, sizeof(*b), + sizeof(*b)); + if (ret) { + if (buffers) + vfree(buffers); + + return ret; + } + + /* If count is zero, we were just checking for format. */ + if (b->count == 0) + return 0; + + memcpy(buffers, queue->buffers, + sizeof(*queue->buffers) * queue->allocated_bufs); + vfree(queue->buffers); + queue->buffers = buffers; + + queue->allocated_bufs = b->index + b->count; + + return 0; +} + +static int virtio_media_prepare_buf(struct file *file, void *fh, + struct v4l2_buffer *b) +{ + struct v4l2_fh *vfh = file_to_v4l2_fh(file); + struct virtio_media_session *session = fh_to_session(vfh); + struct virtio_media_queue_state *queue; + struct virtio_media_buffer *buffer; + int i, ret; + + if (b->type > VIRTIO_MEDIA_LAST_QUEUE) + return -EINVAL; + queue = &session->queues[b->type]; + if (b->index >= queue->allocated_bufs) + return -EINVAL; + buffer = &queue->buffers[b->index]; + + buffer->buffer.m = b->m; + if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { + if (b->length > VIDEO_MAX_PLANES) + return -EINVAL; + for (i = 0; i < b->length; i++) + buffer->planes[i].m = b->m.planes[i].m; + } + + ret = virtio_media_send_buffer_ioctl(vfh, VIDIOC_PREPARE_BUF, b); + if (ret) + return ret; + + buffer->buffer.flags = V4L2_BUF_FLAG_PREPARED; + + return 0; +} + +static int virtio_media_qbuf(struct file *file, void *fh, struct v4l2_buffer *b) +{ + struct v4l2_fh *vfh = file_to_v4l2_fh(file); + struct virtio_media_session *session = fh_to_session(vfh); + struct virtio_media_queue_state *queue; + struct virtio_media_buffer *buffer; + bool prepared; + u32 old_flags; + int i, ret; + + if (b->type > VIRTIO_MEDIA_LAST_QUEUE) + return -EINVAL; + queue = &session->queues[b->type]; + if (b->index >= queue->allocated_bufs) + return -EINVAL; + buffer = &queue->buffers[b->index]; + prepared = buffer->buffer.flags & V4L2_BUF_FLAG_PREPARED; + + /* + * Store the buffer and plane `m` information so we can retrieve + * it again when DQBUF occurs. + */ + if (!prepared) { + buffer->buffer.m = b->m; + if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { + if (b->length > VIDEO_MAX_PLANES) + return -EINVAL; + for (i = 0; i < b->length; i++) + buffer->planes[i].m = b->m.planes[i].m; + } + } + old_flags = buffer->buffer.flags; + buffer->buffer.flags = V4L2_BUF_FLAG_QUEUED; + + ret = virtio_media_send_buffer_ioctl(vfh, VIDIOC_QBUF, b); + if (ret) { + /* Rollback the previous flags as the buffer is not queued. */ + buffer->buffer.flags = old_flags; + return ret; + } + + queue->queued_bufs += 1; + + return 0; +} + +static int virtio_media_dqbuf(struct file *file, void *fh, + struct v4l2_buffer *b) +{ + struct video_device *video_dev = video_devdata(file); + struct virtio_media *vv = to_virtio_media(video_dev); + struct virtio_media_session *session = + fh_to_session(file_to_v4l2_fh(file)); + struct virtio_media_buffer *dqbuf; + struct virtio_media_queue_state *queue; + struct list_head *buffer_queue; + struct v4l2_plane *planes_backup = NULL; + const bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(b->type); + int ret; + bool error; + + if (b->type > VIRTIO_MEDIA_LAST_QUEUE) + return -EINVAL; + + queue = &session->queues[b->type]; + + /* + * If a buffer with the LAST flag has been returned, subsequent + * calls to DQBUF must return -EPIPE until the queue is cleared. + */ + if (queue->is_capture_last) + return -EPIPE; + + buffer_queue = &queue->pending_dqbufs; + + if (session->nonblocking_dequeue) { + if (list_empty(buffer_queue)) + return -EAGAIN; + } else if (queue->allocated_bufs == 0) { + return -EINVAL; + } else if (!queue->streaming) { + return -EINVAL; + } + + /* + * vv->lock has been acquired by virtio_media_device_ioctl. Release it + * while we wait so that other ioctls for this session can be processed + * and potentially trigger dqbuf_wait. + */ + mutex_unlock(&vv->vlock); + + /* + * It's not possible to acquire ``session->error_lock`` during the + * check, however this shouldn't cause issues because: + * - The lock is acquired when actually checking the value + * - The ``session->error`` flag is never reset once set + */ + ret = wait_event_interruptible(session->dqbuf_wait, + !list_empty(buffer_queue) || + session->error); + mutex_lock(&vv->vlock); + if (ret) + return -EINTR; + + mutex_lock(&session->error_lock); + error = session->error; + mutex_unlock(&session->error_lock); + + if (error) + return -EIO; + + mutex_lock(&session->queues_lock); + dqbuf = list_first_entry_or_null(buffer_queue, + struct virtio_media_buffer, list); + + if (dqbuf) + list_del(&dqbuf->list); + + mutex_unlock(&session->queues_lock); + + if (!dqbuf) { + v4l2_err(&vv->v4l2_dev, "No buffer found when dqbuf event triggered\n"); + return -EIO; + } + + /* Clear the DONE flag as the buffer is now being dequeued. */ + dqbuf->buffer.flags &= ~V4L2_BUF_FLAG_DONE; + + if (is_multiplanar) { + size_t nb_planes = min_t(u32, b->length, VIDEO_MAX_PLANES); + + memcpy(b->m.planes, dqbuf->planes, + nb_planes * sizeof(struct v4l2_plane)); + planes_backup = b->m.planes; + } + + memcpy(b, &dqbuf->buffer, sizeof(*b)); + + if (is_multiplanar) + b->m.planes = planes_backup; + + if (V4L2_TYPE_IS_CAPTURE(b->type) && b->flags & V4L2_BUF_FLAG_LAST) + queue->is_capture_last = true; + + return 0; +} + /* * s/g_input/output work with an unsigned int - recast this to a u32 so the * size is unambiguous. @@ -532,6 +1089,32 @@ static int virtio_media_s_output(struct file *file, void *fh, unsigned int o) sizeof(output), sizeof(output)); } +/* + * decoder_cmd can affect the state of the CAPTURE queue. + */ + +static int virtio_media_decoder_cmd(struct file *file, void *fh, + struct v4l2_decoder_cmd *cmd) +{ + struct v4l2_fh *vfh = file_to_v4l2_fh(file); + struct virtio_media_session *session = fh_to_session(vfh); + + int ret = virtio_media_send_wr_ioctl(vfh, VIDIOC_DECODER_CMD, cmd, + sizeof(*cmd), sizeof(*cmd)); + if (ret) + return ret; + + /* A START command makes the CAPTURE queue able to dequeue again. */ + if (cmd->cmd == V4L2_DEC_CMD_START) { + session->queues[V4L2_BUF_TYPE_VIDEO_CAPTURE].is_capture_last = + false; + session->queues[V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE] + .is_capture_last = false; + } + + return 0; +} + /* * s_std doesn't work with a pointer, so we cannot use SIMPLE_W_IOCTL. */ @@ -607,6 +1190,25 @@ const struct v4l2_ioctl_ops virtio_media_ioctl_ops = { .vidioc_try_fmt_meta_cap = virtio_media_try_fmt, .vidioc_try_fmt_meta_out = virtio_media_try_fmt, + /* Buffer handlers */ + .vidioc_reqbufs = virtio_media_reqbufs, + .vidioc_querybuf = virtio_media_querybuf, + .vidioc_qbuf = virtio_media_qbuf, + .vidioc_expbuf = NULL, + .vidioc_dqbuf = virtio_media_dqbuf, + .vidioc_create_bufs = virtio_media_create_bufs, + .vidioc_prepare_buf = virtio_media_prepare_buf, + /* Overlay interface not supported yet */ + .vidioc_overlay = NULL, + /* Overlay interface not supported yet */ + .vidioc_g_fbuf = NULL, + /* Overlay interface not supported yet */ + .vidioc_s_fbuf = NULL, + + /* Stream on/off */ + .vidioc_streamon = virtio_media_streamon, + .vidioc_streamoff = virtio_media_streamoff, + /* Standard handling */ .vidioc_g_std = virtio_media_g_std, .vidioc_s_std = virtio_media_s_std, @@ -658,6 +1260,7 @@ const struct v4l2_ioctl_ops virtio_media_ioctl_ops = { .vidioc_g_enc_index = virtio_media_g_enc_index, .vidioc_encoder_cmd = virtio_media_encoder_cmd, .vidioc_try_encoder_cmd = virtio_media_try_encoder_cmd, + .vidioc_decoder_cmd = virtio_media_decoder_cmd, .vidioc_try_decoder_cmd = virtio_media_try_decoder_cmd, /* Stream type-dependent parameter ioctls */ @@ -692,6 +1295,9 @@ const struct v4l2_ioctl_ops virtio_media_ioctl_ops = { .vidioc_g_edid = NULL, .vidioc_s_edid = NULL, + .vidioc_subscribe_event = virtio_media_subscribe_event, + .vidioc_unsubscribe_event = virtio_media_unsubscribe_event, + /* For other private ioctls */ .vidioc_default = NULL, }; @@ -705,9 +1311,19 @@ long virtio_media_device_ioctl(struct file *file, unsigned int cmd, struct v4l2_standard standard; v4l2_std_id std_id = 0; int ret; + bool error; - if (test_bit(V4L2_FL_USES_V4L2_FH, &video_dev->flags)) + if (test_bit(V4L2_FL_USES_V4L2_FH, &video_dev->flags)) { vfh = file_to_v4l2_fh(file); + struct virtio_media_session *session = fh_to_session(vfh); + + mutex_lock(&session->error_lock); + error = session->error; + mutex_unlock(&session->error_lock); + + if (error) + return -EIO; + } mutex_lock(&vv->vlock); diff --git a/include/uapi/linux/virtio_media.h b/include/uapi/linux/virtio_media.h index f117b97fc..da5c5baf0 100644 --- a/include/uapi/linux/virtio_media.h +++ b/include/uapi/linux/virtio_media.h @@ -171,4 +171,72 @@ struct virtio_media_sg_entry { __le32 __reserved; }; +/* The values for these events are set by the virtio-media specification. */ +#define VIRTIO_MEDIA_EVT_ERROR 0 +#define VIRTIO_MEDIA_EVT_DQBUF 1 +#define VIRTIO_MEDIA_EVT_EVENT 2 + +/** + * struct virtio_media_event_header - Header for events on the eventq. + * @event: one of VIRTIO_MEDIA_EVT_* + * @session_id: ID of the session the event applies to. + */ +struct virtio_media_event_header { + __le32 event; + __le32 session_id; +}; + +/** + * struct virtio_media_event_error - Unrecoverable device-side error. + * @hdr: header for the event. + * @error: error code describing the kind of error that occurred. + * @__reserved: must be set to zero by the device. + * + * Upon receiving this event, the session mentioned in the header is considered + * corrupted and closed. + */ +struct virtio_media_event_error { + struct virtio_media_event_header hdr; + __le32 error; + __le32 __reserved; +}; + +/* This is set to VIDEO_MAX_PLANES defined in include/uapi/linux/videodev2.h. + * It is renamed here to match the constant that is defined in the virtio-media + * specification. + */ +#define VIRTIO_MEDIA_MAX_PLANES VIDEO_MAX_PLANES + +/** + * struct virtio_media_event_dqbuf - Dequeued buffer event. + * @hdr: header for the event. + * @buffer: &struct v4l2_buffer describing the buffer that has been dequeued. + * @planes: plane information for the dequeued buffer. + * + * This event is used to signal that a buffer is not being used anymore by the + * device and is returned to the driver. + */ +struct virtio_media_event_dqbuf { + struct virtio_media_event_header hdr; + struct v4l2_buffer buffer; + struct v4l2_plane planes[VIRTIO_MEDIA_MAX_PLANES]; +}; + +/** + * struct virtio_media_event_event - V4L2 event. + * @hdr: header for the event. + * @event: description of the event that occurred. + * + * This event signals that a V4L2 event has been emitted for a session. + */ +struct virtio_media_event_event { + struct virtio_media_event_header hdr; + struct v4l2_event event; +}; + +/* Maximum size of an event. We will queue descriptors of this size on the + * eventq. + */ +#define VIRTIO_MEDIA_EVENT_MAX_SIZE sizeof(struct virtio_media_event_dqbuf) + #endif // _UAPI__LINUX_VIRTIO_MEDIA_H -- 2.56.0.317.g454f8302e1-goog
