BACKPORT: media: videobuf2: handle V4L2 buffer cache flags

Set video buffer cache management flags corresponding to V4L2 cache
flags.

Both ->prepare() and ->finish() cache management hints should be
passed during this stage (buffer preparation), because there is
no other way for user-space to tell V4L2 to avoid ->finish() cache
flush.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
(cherry picked from commit f5f5fa73fb)

Conflicts:
	drivers/media/common/videobuf2/videobuf2-v4l2.c

Change-Id: I6d90d080a7468be5e8f96b26dcd36bf583bd5741
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
This commit is contained in:
Sergey Senozhatsky
2020-05-14 18:01:42 +02:00
committed by Tao Huang
parent 8061fe2a75
commit 00d81d9d97
2 changed files with 60 additions and 0 deletions

View File

@@ -153,6 +153,53 @@ static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
pr_warn("use the actual size instead.\n");
}
static void set_buffer_cache_hints(struct vb2_queue *q,
struct vb2_buffer *vb,
struct v4l2_buffer *b)
{
/*
* DMA exporter should take care of cache syncs, so we can avoid
* explicit ->prepare()/->finish() syncs. For other ->memory types
* we always need ->prepare() or/and ->finish() cache sync.
*/
if (q->memory == VB2_MEMORY_DMABUF) {
vb->need_cache_sync_on_finish = 0;
vb->need_cache_sync_on_prepare = 0;
return;
}
/*
* Cache sync/invalidation flags are set by default in order to
* preserve existing behaviour for old apps/drivers.
*/
vb->need_cache_sync_on_prepare = 1;
vb->need_cache_sync_on_finish = 1;
if (!vb2_queue_allows_cache_hints(q)) {
/*
* Clear buffer cache flags if queue does not support user
* space hints. That's to indicate to userspace that these
* flags won't work.
*/
b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_INVALIDATE;
b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_CLEAN;
return;
}
/*
* ->finish() cache sync can be avoided when queue direction is
* TO_DEVICE.
*/
if (q->dma_dir == DMA_TO_DEVICE)
vb->need_cache_sync_on_finish = 0;
if (b->flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE)
vb->need_cache_sync_on_finish = 0;
if (b->flags & V4L2_BUF_FLAG_NO_CACHE_CLEAN)
vb->need_cache_sync_on_prepare = 0;
}
static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
const char *opname)
{
@@ -177,6 +224,8 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
return -EINVAL;
}
set_buffer_cache_hints(q, q->bufs[b->index], b);
return __verify_planes_array(q->bufs[b->index], b);
}

View File

@@ -583,6 +583,17 @@ struct vb2_queue {
#endif
};
/**
* vb2_queue_allows_cache_hints() - Return true if the queue allows cache
* and memory consistency hints.
*
* @q: pointer to &struct vb2_queue with videobuf2 queue
*/
static inline bool vb2_queue_allows_cache_hints(struct vb2_queue *q)
{
return q->allow_cache_hints && q->memory == VB2_MEMORY_MMAP;
}
/**
* vb2_plane_vaddr() - Return a kernel virtual address of a given plane.
* @vb: pointer to &struct vb2_buffer to which the plane in