On 21/05/18 18:59, Ezequiel Garcia wrote:
> From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
>
> If V4L2_BUF_FLAG_OUT_FENCE flag is present on the QBUF call we create
> an out_fence and send its fd to userspace in the fence_fd field as a
> return arg for the QBUF call.
>
> The fence is signaled on buffer_done(), when the job on the buffer is
> finished.
>
> v12: - Pass the fence_fd in vb2_qbuf for clarity.
> - Increase fence seqno if fence context if shared
> - Check get_unused_fd return
v12 while this this PATCH v10? That's a bit confusing.
>
> v11: - Return fence_fd to userpace only in the QBUF ioctl.
> - Rework implementation to avoid storing the sync_file
> as state, which is not really needed.
>
> v10: - use -EIO for fence error (Hans Verkuil)
> - add comment around fence context creation (Hans Verkuil)
>
> v9: - remove in-fences changes from this patch (Alex Courbot)
> - improve fence context creation (Hans Verkuil)
> - clean up out fences if vb2_core_qbuf() fails (Hans Verkuil)
>
> v8: - return 0 as fence_fd if OUT_FENCE flag not used (Mauro)
> - fix crash when checking not using fences in vb2_buffer_done()
>
> v7: - merge patch that add the infrastructure to out-fences into
> this one (Alex Courbot)
> - Do not install the fd if there is no fence. (Alex Courbot)
> - do not report error on requeueing, just WARN_ON_ONCE() (Hans)
>
> v6: - get rid of the V4L2_EVENT_OUT_FENCE event. We always keep the
> ordering in vb2 for queueing in the driver, so the event is not
> necessary anymore and the out_fence_fd is sent back to userspace
> on QBUF call return arg
> - do not allow requeueing with out-fences, instead mark the buffer
> with an error and wake up to userspace.
> - send the out_fence_fd back to userspace on the fence_fd field
>
> v5: - delay fd_install to DQ_EVENT (Hans)
> - if queue is fully ordered send OUT_FENCE event right away
> (Brian)
> - rename 'q->ordered' to 'q->ordered_in_driver'
> - merge change to implement OUT_FENCE event here
>
> v4: - return the out_fence_fd in the BUF_QUEUED event(Hans)
>
> v3: - add WARN_ON_ONCE(q->ordered) on requeueing (Hans)
> - set the OUT_FENCE flag if there is a fence pending (Hans)
> - call fd_install() after vb2_core_qbuf() (Hans)
> - clean up fence if vb2_core_qbuf() fails (Hans)
> - add list to store sync_file and fence for the next queued buffer
>
> v2: check if the queue is ordered.
>
> Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
> ---
> drivers/media/common/videobuf2/videobuf2-core.c | 113 +++++++++++++++++++++++-
> drivers/media/common/videobuf2/videobuf2-v4l2.c | 10 ++-
> drivers/media/dvb-core/dvb_vb2.c | 2 +-
> include/media/videobuf2-core.h | 20 ++++-
> 4 files changed, 136 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index 86b5ebe25263..edc2fdaf56de 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -25,6 +25,7 @@
> #include <linux/sched.h>
> #include <linux/freezer.h>
> #include <linux/kthread.h>
> +#include <linux/sync_file.h>
>
> #include <media/videobuf2-core.h>
> #include <media/v4l2-ioctl.h>
> @@ -380,6 +381,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> vb->planes[plane].length = plane_sizes[plane];
> vb->planes[plane].min_length = plane_sizes[plane];
> }
> + vb->out_fence_fd = -1;
> q->bufs[vb->index] = vb;
>
> /* Allocate video buffer memory for the MMAP type */
> @@ -976,10 +978,22 @@ static void vb2_process_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state
> case VB2_BUF_STATE_QUEUED:
> return;
> case VB2_BUF_STATE_REQUEUEING:
> + /* Requeuing with explicit synchronization, spit warning */
> + WARN_ON_ONCE(vb->out_fence);
> +
> if (q->start_streaming_called)
> __enqueue_in_driver(vb);
> return;
> default:
> + if (vb->out_fence) {
> + if (state == VB2_BUF_STATE_ERROR)
> + dma_fence_set_error(vb->out_fence, -EIO);
> + dma_fence_signal(vb->out_fence);
> + dma_fence_put(vb->out_fence);
> + vb->out_fence = NULL;
> + vb->out_fence_fd = -1;
> + }
> +
> /* Inform any processes that may be waiting for buffers */
> wake_up(&q->done_wq);
> break;
> @@ -1406,6 +1420,76 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
> }
> EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
>
> +static inline const char *vb2_fence_get_driver_name(struct dma_fence *fence)
> +{
> + return "vb2_fence";
> +}
> +
> +static inline const char *vb2_fence_get_timeline_name(struct dma_fence *fence)
> +{
> + return "vb2_fence_timeline";
> +}
> +
> +static inline bool vb2_fence_enable_signaling(struct dma_fence *fence)
> +{
> + return true;
> +}
Does inline make sense since this functions are used as ops below?
I think that can be dropped.
Regards,
Hans
> +
> +static const struct dma_fence_ops vb2_fence_ops = {
> + .get_driver_name = vb2_fence_get_driver_name,
> + .get_timeline_name = vb2_fence_get_timeline_name,
> + .enable_signaling = vb2_fence_enable_signaling,
> + .wait = dma_fence_default_wait,
> +};
> +
> +static int vb2_setup_out_fence(struct vb2_queue *q, struct vb2_buffer *vb)
> +{
> + struct sync_file *sync_file;
> + unsigned int seqno;
> + int ret, fd;
> +
> + fd = get_unused_fd_flags(O_CLOEXEC);
> + if (fd < 0)
> + return fd;
> +
> + /*
> + * The same context can be used only if the queue is ordered,
> + * so if the queue is ordered create one when the queueing start,
> + * otherwise create one for every buffer
> + */
> + if (call_qop(q, is_unordered, q)) {
> + q->out_fence_context = dma_fence_context_alloc(1);
> + seqno = 1;
> + } else {
> + seqno = q->out_fence_seqno++;
> + }
> +
> + vb->out_fence = kzalloc(sizeof(*vb->out_fence), GFP_KERNEL);
> + if (!vb->out_fence) {
> + ret = -ENOMEM;
> + goto err_put_fd;
> + }
> + dma_fence_init(vb->out_fence, &vb2_fence_ops, &q->out_fence_lock,
> + q->out_fence_context, seqno);
> +
> + sync_file = sync_file_create(vb->out_fence);
> + if (!sync_file) {
> + ret = -ENOMEM;
> + goto err_free_fence;
> + }
> + fd_install(fd, sync_file->file);
> + vb->out_fence_fd = fd;
> + return 0;
> +
> +err_free_fence:
> + dma_fence_put(vb->out_fence);
> + vb->out_fence = NULL;
> +err_put_fd:
> + put_unused_fd(vb->out_fence_fd);
> + vb->out_fence_fd = -1;
> + return ret;
> +}
> +
> /*
> * vb2_start_streaming() - Attempt to start streaming.
> * @q: videobuf2 queue
> @@ -1508,7 +1592,7 @@ static void vb2_qbuf_fence_cb(struct dma_fence *f, struct dma_fence_cb *cb)
> }
>
> int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
> - struct dma_fence *in_fence)
> + struct dma_fence *in_fence, int *out_fence_fd)
> {
> struct vb2_buffer *vb;
> int ret;
> @@ -1540,6 +1624,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
> list_add_tail(&vb->queued_entry, &q->queued_list);
> q->queued_count++;
> q->waiting_for_buffers = false;
> + q->queueing_started = 1;
> vb->state = VB2_BUF_STATE_QUEUED;
>
> if (pb)
> @@ -1600,6 +1685,20 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
> goto err_release;
> }
>
> + if (out_fence_fd) {
> + *out_fence_fd = -1;
> + ret = vb2_setup_out_fence(q, vb);
> + if (ret) {
> + dprintk(1, "failed to set up out-fence\n");
> + goto err_release;
> + }
> +
> + /* If we have successfully created an out-fence,
> + * return its fd.
> + */
> + *out_fence_fd = vb->out_fence_fd;
> + }
> +
> /* Fill buffer information for userspace */
> if (pb)
> call_void_bufop(q, fill_user_buffer, vb, pb);
> @@ -1864,6 +1963,7 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
> q->start_streaming_called = 0;
> q->queued_count = 0;
> q->error = 0;
> + q->queueing_started = 0;
>
> /*
> * Remove all buffers from videobuf's list...
> @@ -2206,7 +2306,12 @@ int vb2_core_queue_init(struct vb2_queue *q)
> spin_lock_init(&q->done_lock);
> mutex_init(&q->mmap_lock);
> init_waitqueue_head(&q->done_wq);
> + spin_lock_init(&q->out_fence_lock);
>
> + if (!call_qop(q, is_unordered, q)) {
> + q->out_fence_context = dma_fence_context_alloc(1);
> + q->out_fence_seqno = 1;
> + }
> q->memory = VB2_MEMORY_UNKNOWN;
>
> if (q->buf_struct_size == 0)
> @@ -2457,7 +2562,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
> * Queue all buffers.
> */
> for (i = 0; i < q->num_buffers; i++) {
> - ret = vb2_core_qbuf(q, i, NULL, NULL);
> + ret = vb2_core_qbuf(q, i, NULL, NULL, NULL);
> if (ret)
> goto err_reqbufs;
> fileio->bufs[i].queued = 1;
> @@ -2636,7 +2741,7 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
>
> if (copy_timestamp)
> b->timestamp = ktime_get_ns();
> - ret = vb2_core_qbuf(q, index, NULL, NULL);
> + ret = vb2_core_qbuf(q, index, NULL, NULL, NULL);
> dprintk(5, "vb2_dbuf result: %d\n", ret);
> if (ret)
> return ret;
> @@ -2739,7 +2844,7 @@ static int vb2_thread(void *data)
> if (copy_timestamp)
> vb->timestamp = ktime_get_ns();
> if (!threadio->stop)
> - ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
> + ret = vb2_core_qbuf(q, vb->index, NULL, NULL, NULL);
> call_void_qop(q, wait_prepare, q);
> if (ret || threadio->stop)
> break;
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index ac14cc8ab1c5..b4908d0432c6 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -588,8 +588,9 @@ EXPORT_SYMBOL_GPL(vb2_create_bufs);
>
> int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
> {
> + bool get_out_fence = b->flags & V4L2_BUF_FLAG_OUT_FENCE;
> struct dma_fence *in_fence = NULL;
> - int ret;
> + int ret, fence_fd;
>
> if (vb2_fileio_is_active(q)) {
> dprintk(1, "file io in progress\n");
> @@ -609,7 +610,12 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
> }
> }
>
> - return vb2_core_qbuf(q, b->index, b, in_fence);
> + ret = vb2_core_qbuf(q, b->index, b, in_fence,
> + get_out_fence ? &fence_fd : NULL);
> + if (ret)
> + return ret;
> + b->fence_fd = fence_fd;
> + return 0;
> }
> EXPORT_SYMBOL_GPL(vb2_qbuf);
>
> diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c
> index 7da53f10db1a..5c1523a8accc 100644
> --- a/drivers/media/dvb-core/dvb_vb2.c
> +++ b/drivers/media/dvb-core/dvb_vb2.c
> @@ -385,7 +385,7 @@ int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b)
> {
> int ret;
>
> - ret = vb2_core_qbuf(&ctx->vb_q, b->index, b, NULL);
> + ret = vb2_core_qbuf(&ctx->vb_q, b->index, b, NULL, NULL);
> if (ret) {
> dprintk(1, "[%s] index=%d errno=%d\n", ctx->name,
> b->index, ret);
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index ddd555f59dbf..6abe133d1c9a 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -262,6 +262,9 @@ struct vb2_buffer {
> * using the buffer (queueing to the driver)
> * fence_cb: fence callback information
> * qbuf_work: work for deferred qbuf operation
> + * out_fence_fd: the out_fence_fd to be shared with userspace.
> + * out_fence: the out-fence associated with the buffer once
> + * it is queued to the driver.
> */
> struct kref refcount;
> enum vb2_buffer_state state;
> @@ -274,6 +277,9 @@ struct vb2_buffer {
> struct dma_fence_cb fence_cb;
> struct work_struct qbuf_work;
>
> + int out_fence_fd;
> + struct dma_fence *out_fence;
> +
> #ifdef CONFIG_VIDEO_ADV_DEBUG
> /*
> * Counters for how often these buffer-related ops are
> @@ -550,6 +556,10 @@ struct vb2_buf_ops {
> * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
> * last decoded buffer was already dequeued. Set for capture queues
> * when a buffer with the %V4L2_BUF_FLAG_LAST is dequeued.
> + * @queueing_started: if queueing has started. Currently used to determine
> + * if an out_fence_context is needed.
> + * @out_fence_context: the fence context for the out fences
> + * @out_fence_seqno: the fence seqno to use, if the context is shared
> * @fileio: file io emulator internal data, used only if emulator is active
> * @threadio: thread io internal data, used only if thread is active
> */
> @@ -602,6 +612,11 @@ struct vb2_queue {
> unsigned int is_output:1;
> unsigned int copy_timestamp:1;
> unsigned int last_buffer_dequeued:1;
> + unsigned int queueing_started:1;
> +
> + u64 out_fence_context;
> + unsigned int out_fence_seqno;
> + spinlock_t out_fence_lock;
>
> struct vb2_fileio_data *fileio;
> struct vb2_threadio_data *threadio;
> @@ -800,7 +815,8 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
> * @index: id number of the buffer
> * @pb: buffer structure passed from userspace to
> * v4l2_ioctl_ops->vidioc_qbuf handler in driver
> - * @in_fence: in-fence to wait on before queueing the buffer
> + * @in_fence: optioanl in-fence to wait on before queueing the buffer
> + * @out_fence_fd: optional pointer to store a newly created out-fence fd
> *
> * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called
> * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
> @@ -816,7 +832,7 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
> * Return: returns zero on success; an error code otherwise.
> */
> int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
> - struct dma_fence *in_fence);
> + struct dma_fence *in_fence, int *out_fence_fd);
>
> /**
> * vb2_core_dqbuf() - Dequeue a buffer to the userspace
>
