[PATCHv3 2/8] videobuf2: inverse buffer cache_hints flags

Sergey Senozhatsky
2021-07-09T09:20:43Z

It would be less error prone if the default cache hints value
(we kzalloc() structs, so it's zeroed out by default) would be
to "always sync/flush" caches. Inverse and rename cache hints
flags.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
.../media/common/videobuf2/videobuf2-core.c | 31 ++++++-------------
.../media/common/videobuf2/videobuf2-v4l2.c | 17 +++-------
include/media/videobuf2-core.h | 12 +++----
3 files changed, 21 insertions(+), 39 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 9a5cc3e63439..23e41fec9880 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -327,12 +327,12 @@ static void __vb2_buf_mem_prepare(struct vb2_buffer *vb)
if (vb->synced)
return;

- if (vb->need_cache_sync_on_prepare) {
- for (plane = 0; plane < vb->num_planes; ++plane)
- call_void_memop(vb, prepare,
- vb->planes[plane].mem_priv);
- }
vb->synced = 1;
+ if (vb->skip_cache_sync_on_prepare)
+ return;
+
+ for (plane = 0; plane < vb->num_planes; ++plane)
+ call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
}

/*
@@ -346,12 +346,12 @@ static void __vb2_buf_mem_finish(struct vb2_buffer *vb)
if (!vb->synced)
return;

- if (vb->need_cache_sync_on_finish) {
- for (plane = 0; plane < vb->num_planes; ++plane)
- call_void_memop(vb, finish,
- vb->planes[plane].mem_priv);
- }
vb->synced = 0;
+ if (vb->skip_cache_sync_on_finish)
+ return;
+
+ for (plane = 0; plane < vb->num_planes; ++plane)
+ call_void_memop(vb, finish, vb->planes[plane].mem_priv);
}

/*
@@ -415,17 +415,6 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
vb->index = q->num_buffers + buffer;
vb->type = q->type;
vb->memory = memory;
- /*
- * We need to set these flags here so that the videobuf2 core
- * will call ->prepare()/->finish() cache sync/flush on vb2
- * buffers when appropriate. However, we can avoid explicit
- * ->prepare() and ->finish() cache sync for DMABUF buffers,
- * because DMA exporter takes care of it.
- */
- if (q->memory != VB2_MEMORY_DMABUF) {
- vb->need_cache_sync_on_prepare = 1;
- vb->need_cache_sync_on_finish = 1;
- }
for (plane = 0; plane < num_planes; ++plane) {
vb->planes[plane].length = plane_sizes[plane];
vb->planes[plane].min_length = plane_sizes[plane];
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 2988bb38ceb1..454d58268602 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -351,18 +351,11 @@ static void set_buffer_cache_hints(struct vb2_queue *q,
* 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;
+ vb->skip_cache_sync_on_finish = 1;
+ vb->skip_cache_sync_on_prepare = 1;
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
@@ -379,13 +372,13 @@ static void set_buffer_cache_hints(struct vb2_queue *q,
* TO_DEVICE.
*/
if (q->dma_dir == DMA_TO_DEVICE)
- vb->need_cache_sync_on_finish = 0;
+ vb->skip_cache_sync_on_finish = 1;

if (b->flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE)
- vb->need_cache_sync_on_finish = 0;
+ vb->skip_cache_sync_on_finish = 1;

if (b->flags & V4L2_BUF_FLAG_NO_CACHE_CLEAN)
- vb->need_cache_sync_on_prepare = 0;
+ vb->skip_cache_sync_on_prepare = 1;
}

static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 3b5986cee073..66e548268242 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -267,10 +267,10 @@ struct vb2_buffer {
* after the 'buf_finish' op is called.
* copied_timestamp: the timestamp of this capture buffer was copied
* from an output buffer.
- * need_cache_sync_on_prepare: when set buffer's ->prepare() function
- * performs cache sync/invalidation.
- * need_cache_sync_on_finish: when set buffer's ->finish() function
- * performs cache sync/invalidation.
+ * skip_cache_sync_on_prepare: when set buffer's ->prepare() function
+ * skips cache sync/invalidation.
+ * skip_cache_sync_on_finish: when set buffer's ->finish() function
+ * skips cache sync/invalidation.
* queued_entry: entry on the queued buffers list, which holds
* all buffers queued from userspace
* done_entry: entry on the list that stores all buffers ready
@@ -281,8 +281,8 @@ struct vb2_buffer {
unsigned int synced:1;
unsigned int prepared:1;
unsigned int copied_timestamp:1;
- unsigned int need_cache_sync_on_prepare:1;
- unsigned int need_cache_sync_on_finish:1;
+ unsigned int skip_cache_sync_on_prepare:1;
+ unsigned int skip_cache_sync_on_finish:1;

struct vb2_plane planes[VB2_MAX_PLANES];
struct list_head queued_entry;
--
2.32.0.93.g670b81a890-goog