Commit d4db5eb5 authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Mauro Carvalho Chehab
Browse files

media: videobuf2: add begin/end cpu_access callbacks to dma-sg 



Provide begin_cpu_access() and end_cpu_access() dma_buf_ops
callbacks for cache synchronisation on exported buffers.

V4L2_FLAG_MEMORY_NON_CONSISTENT has no effect on dma-sg buffers.
dma-sg allocates memory using the page allocator directly, so
there is no memory consistency guarantee.

Signed-off-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent d5adf1b0

drivers/media/common/videobuf2/videobuf2-dma-sg.c

+30 −0
Original line number Diff line number Diff line
@@ -120,6 +120,12 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs, 
	buf->num_pages = size >> PAGE_SHIFT;

	buf->dma_sgt = &buf->sg_table;



	/*

	 * NOTE: dma-sg allocates memory using the page allocator directly, so

	 * there is no memory consistency guarantee, hence dma-sg ignores DMA

	 * attributes passed from the upper layer. That means that

	 * V4L2_FLAG_MEMORY_NON_CONSISTENT has no effect on dma-sg buffers.

	 */

	buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),

				    GFP_KERNEL | __GFP_ZERO);

	if (!buf->pages)
@@ -469,6 +475,28 @@ static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf) 
	vb2_dma_sg_put(dbuf->priv);

}



static int

vb2_dma_sg_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,

				       enum dma_data_direction direction)

{

	struct vb2_dma_sg_buf *buf = dbuf->priv;

	struct sg_table *sgt = buf->dma_sgt;



	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);

	return 0;

}



static int

vb2_dma_sg_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,

				     enum dma_data_direction direction)

{

	struct vb2_dma_sg_buf *buf = dbuf->priv;

	struct sg_table *sgt = buf->dma_sgt;



	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);

	return 0;

}



static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf)

{

	struct vb2_dma_sg_buf *buf = dbuf->priv;
@@ -487,6 +515,8 @@ static const struct dma_buf_ops vb2_dma_sg_dmabuf_ops = { 
	.detach = vb2_dma_sg_dmabuf_ops_detach,

	.map_dma_buf = vb2_dma_sg_dmabuf_ops_map,

	.unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap,

	.begin_cpu_access = vb2_dma_sg_dmabuf_ops_begin_cpu_access,

	.end_cpu_access = vb2_dma_sg_dmabuf_ops_end_cpu_access,

	.vmap = vb2_dma_sg_dmabuf_ops_vmap,

	.mmap = vb2_dma_sg_dmabuf_ops_mmap,

	.release = vb2_dma_sg_dmabuf_ops_release,