From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Provide begin_cpu_access() and end_cpu_access() callbacks for
cache synchronisation on exported buffers.
The patch also adds a new helper function - vb2_dc_buffer_consistent(),
which returns true is if the buffer is consistent (DMA_ATTR_NON_CONSISTENT
bit cleared), so then we don't need to sync anything.
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
.../common/videobuf2/videobuf2-dma-contig.c | 35 +++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index d3a3ee5b597b..6787e2cb905e 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -42,6 +42,11 @@ struct vb2_dc_buf {
struct dma_buf_attachment *db_attach;
};
+static inline bool vb2_dc_buffer_consistent(unsigned long attr)
+{
+ return !(attr & DMA_ATTR_NON_CONSISTENT);
+}
+
/*********************************************/
/* scatterlist table functions */
/*********************************************/
@@ -335,6 +340,34 @@ static void vb2_dc_dmabuf_ops_release(struct dma_buf *dbuf)
vb2_dc_put(dbuf->priv);
}
+static int
+vb2_dc_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,
+ enum dma_data_direction direction)
+{
+ struct vb2_dc_buf *buf = dbuf->priv;
+ struct sg_table *sgt = buf->dma_sgt;
+
+ if (vb2_dc_buffer_consistent(buf->attrs))
+ return 0;
+
+ dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+ return 0;
+}
+
+static int
+vb2_dc_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,
+ enum dma_data_direction direction)
+{
+ struct vb2_dc_buf *buf = dbuf->priv;
+ struct sg_table *sgt = buf->dma_sgt;
+
+ if (vb2_dc_buffer_consistent(buf->attrs))
+ return 0;
+
+ dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+ return 0;
+}
+
static void *vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf)
{
struct vb2_dc_buf *buf = dbuf->priv;
@@ -353,6 +386,8 @@ static const struct dma_buf_ops vb2_dc_dmabuf_ops = {
.detach = vb2_dc_dmabuf_ops_detach,
.map_dma_buf = vb2_dc_dmabuf_ops_map,
.unmap_dma_buf = vb2_dc_dmabuf_ops_unmap,
+ .begin_cpu_access = vb2_dc_dmabuf_ops_begin_cpu_access,
+ .end_cpu_access = vb2_dc_dmabuf_ops_end_cpu_access,
.vmap = vb2_dc_dmabuf_ops_vmap,
.mmap = vb2_dc_dmabuf_ops_mmap,
.release = vb2_dc_dmabuf_ops_release,
--
2.26.2
