linux-kernel - [PATCH 3/8] videobuf2: split buffer cache

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Date:   Tue,  2 Mar 2021 09:46:19 +0900
From:   Sergey Senozhatsky <senozhatsky@...omium.org>
To:     Tomasz Figa <tfiga@...omium.org>,
        Hans Verkuil <hverkuil-cisco@...all.nl>
Cc:     Christoph Hellwig <hch@....de>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
        Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: [PATCH 3/8] videobuf2: split buffer cache_hints initialisation

V4L2 is not the perfect place to manage vb2 buffer cache hints.
It works for V4L2 users, but there are backends that use vb2 core
and don't use V4L2. Factor buffer cache hints init and call it
when we allocate vb2 buffer.

Signed-off-by: Sergey Senozhatsky <senozhatsky@...omium.org>
---
 .../media/common/videobuf2/videobuf2-core.c   | 22 +++++++++++++++++++
 .../media/common/videobuf2/videobuf2-v4l2.c   | 18 ---------------
 2 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 23e41fec9880..76210c006958 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -382,6 +382,27 @@ static void __setup_offsets(struct vb2_buffer *vb)
 	}
 }
 
+static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
+{
+	/*
+	 * 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->skip_cache_sync_on_finish = 1;
+		vb->skip_cache_sync_on_prepare = 1;
+		return;
+	}
+
+	/*
+	 * ->finish() cache sync can be avoided when queue direction is
+	 * TO_DEVICE.
+	 */
+	if (q->dma_dir == DMA_TO_DEVICE)
+		vb->skip_cache_sync_on_finish = 1;
+}
+
 /*
  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
  * video buffer memory for all buffers/planes on the queue and initializes the
@@ -415,6 +436,7 @@ 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;
+		init_buffer_cache_hints(q, vb);
 		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 db93678860bd..a02f365bbe60 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -345,17 +345,6 @@ 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->skip_cache_sync_on_finish = 1;
-		vb->skip_cache_sync_on_prepare = 1;
-		return;
-	}
-
 	if (!vb2_queue_allows_cache_hints(q)) {
 		/*
 		 * Clear buffer cache flags if queue does not support user
@@ -367,13 +356,6 @@ static void set_buffer_cache_hints(struct vb2_queue *q,
 		return;
 	}
 
-	/*
-	 * ->finish() cache sync can be avoided when queue direction is
-	 * TO_DEVICE.
-	 */
-	if (q->dma_dir == DMA_TO_DEVICE)
-		vb->skip_cache_sync_on_finish = 1;
-
 	if (b->flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE)
 		vb->skip_cache_sync_on_finish = 1;
 
-- 
2.30.1.766.gb4fecdf3b7-goog