Messages in this thread | | | Date | Wed, 9 May 2018 11:37:56 +0100 | From | Brian Starkey <> | Subject | Re: [PATCH v9 12/15] vb2: add out-fence support to QBUF |
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Hi,
On Fri, May 04, 2018 at 05:06:09PM -0300, Ezequiel Garcia wrote: >From: Gustavo Padovan <gustavo.padovan@collabora.com> > >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. > >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@collabora.com> >Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com> >--- > drivers/media/common/videobuf2/videobuf2-core.c | 95 +++++++++++++++++++++++-- > drivers/media/common/videobuf2/videobuf2-v4l2.c | 22 +++++- > drivers/media/dvb-core/dvb_vb2.c | 2 +- > include/media/videobuf2-core.h | 16 ++++- > 4 files changed, 127 insertions(+), 8 deletions(-) > >diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c >index 996b99497a98..0f7306a04db7 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-mc.h> >@@ -357,6 +358,7 @@ 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 */ >@@ -948,10 +950,22 @@ 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; >@@ -1367,6 +1381,68 @@ 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; >+} >+ >+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; >+ int ret; >+ >+ vb->out_fence_fd = get_unused_fd_flags(O_CLOEXEC);
I think you should check the return value here. fd_install() doesn't seem to do any validation. Best case you hit a BUG_ON(), worst case you trash something random :-(
>+ >+ /* >+ * 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 (q->unordered || !q->queueing_started) >+ q->out_fence_context = dma_fence_context_alloc(1);
Isn't queueing_started always true here? Seems to be set in vb2_core_qbuf() unconditionally, before vb2_setup_out_fence() is called.
>+ >+ 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, 1);
If the context is shared, we should increment the seqno for every fence.
Cheers, -Brian
>+ >+ sync_file = sync_file_create(vb->out_fence); >+ if (!sync_file) { >+ ret = -ENOMEM; >+ goto err_free_fence; >+ } >+ fd_install(vb->out_fence_fd, sync_file->file); >+ 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 >@@ -1463,7 +1539,7 @@ 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, bool out_fence) > { > struct vb2_buffer *vb; > unsigned long flags; >@@ -1496,6 +1572,7 @@ 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; > vb->in_fence = in_fence; > >@@ -1555,6 +1632,14 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb, > > spin_unlock_irqrestore(&vb->fence_cb_lock, flags); > >+ if (out_fence) { >+ ret = vb2_setup_out_fence(q, vb); >+ if (ret) { >+ dprintk(1, "failed to set up out-fence\n"); >+ goto err; >+ } >+ } >+ > /* Fill buffer information for the userspace */ > if (pb) > call_void_bufop(q, fill_user_buffer, vb, pb); >@@ -1818,6 +1903,7 @@ 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; > > list_for_each_entry(vb, &q->queued_list, queued_entry) { > spin_lock_irqsave(&vb->fence_cb_lock, flags); >@@ -2170,6 +2256,7 @@ 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); > > q->memory = VB2_MEMORY_UNKNOWN; > >@@ -2421,7 +2508,7 @@ 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, false); > if (ret) > goto err_reqbufs; > fileio->bufs[i].queued = 1; >@@ -2600,7 +2687,7 @@ 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, false); > dprintk(5, "vb2_dbuf result: %d\n", ret); > if (ret) > return ret; >@@ -2703,7 +2790,7 @@ 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, false); > 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 74d7062e5285..41a88839683e 100644 >--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c >+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c >@@ -217,7 +217,11 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb) > b->sequence = vbuf->sequence; > b->reserved = 0; > >- b->fence_fd = 0; >+ if (b->flags & V4L2_BUF_FLAG_OUT_FENCE) >+ b->fence_fd = vb->out_fence_fd; >+ else >+ b->fence_fd = 0; >+ > if (vb->in_fence) > b->flags |= V4L2_BUF_FLAG_IN_FENCE; > else >@@ -496,6 +500,13 @@ int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b) > ret = __verify_planes_array(vb, b); > if (!ret) > vb2_core_querybuf(q, b->index, b); >+ >+ /* >+ * Can't return a fence fd, because it only >+ * makes sense on the process that queued the buffer. >+ */ >+ if (b->flags & (V4L2_BUF_FLAG_IN_FENCE | V4L2_BUF_FLAG_OUT_FENCE)) >+ b->fence_fd = -1; > return ret; > } > EXPORT_SYMBOL(vb2_querybuf); >@@ -600,7 +611,8 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b) > } > } > >- return vb2_core_qbuf(q, b->index, b, in_fence); >+ return vb2_core_qbuf(q, b->index, b, in_fence, >+ b->flags & V4L2_BUF_FLAG_OUT_FENCE); > } > EXPORT_SYMBOL_GPL(vb2_qbuf); > >@@ -626,6 +638,12 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking) > */ > b->flags &= ~V4L2_BUF_FLAG_DONE; > >+ /* >+ * Can't return a fence fd, because it only >+ * makes sense on the process that queued the buffer. >+ */ >+ if (b->flags & (V4L2_BUF_FLAG_IN_FENCE | V4L2_BUF_FLAG_OUT_FENCE)) >+ b->fence_fd = -1; > return ret; > } > EXPORT_SYMBOL_GPL(vb2_dqbuf); >diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c >index 7da53f10db1a..053803c9ff45 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, false); > 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 28ce8f66882e..794140fcb5cf 100644 >--- a/include/media/videobuf2-core.h >+++ b/include/media/videobuf2-core.h >@@ -260,6 +260,9 @@ struct vb2_buffer { > * using the buffer (queueing to the driver) > * fence_cb: fence callback information > * fence_cb_lock: protect callback signal/remove >+ * 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. > */ > enum vb2_buffer_state state; > >@@ -271,6 +274,9 @@ struct vb2_buffer { > struct dma_fence_cb fence_cb; > spinlock_t fence_cb_lock; > >+ int out_fence_fd; >+ struct dma_fence *out_fence; >+ > #ifdef CONFIG_VIDEO_ADV_DEBUG > /* > * Counters for how often these buffer-related ops are >@@ -533,6 +539,9 @@ 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 > * @fileio: file io emulator internal data, used only if emulator is active > * @threadio: thread io internal data, used only if thread is active > */ >@@ -586,6 +595,10 @@ 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; >+ spinlock_t out_fence_lock; > > struct vb2_fileio_data *fileio; > struct vb2_threadio_data *threadio; >@@ -784,6 +797,7 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); > * @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 >+ * @out_fence: create an out-fence as a part of the queue operation > * > * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called > * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. >@@ -799,7 +813,7 @@ 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, bool out_fence); > > /** > * vb2_core_dqbuf() - Dequeue a buffer to the userspace >-- >2.16.3 >
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