[media] v4l: vb2: add prepare/finish callbacks to allocators

This patch adds support for prepare/finish callbacks in VB2 allocators. These
callback are used for buffer flushing.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 689ae4ac2572..24b9c90194f2 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -56,6 +56,10 @@ struct vb2_fileio_data;
  *              dmabuf
  * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
  *                that this driver is done using the dmabuf for now
+ * @prepare:    called every time the buffer is passed from userspace to the
+ *              driver, useful for cache synchronisation, optional
+ * @finish:     called every time the buffer is passed back from the driver
+ *              to the userspace, also optional
  * @vaddr:      return a kernel virtual address to a given memory buffer
  *              associated with the passed private structure or NULL if no
  *              such mapping exists
@@ -82,6 +86,9 @@ struct vb2_mem_ops {
                                         unsigned long size, int write);
         void            (*put_userptr)(void *buf_priv);
 
+        void            (*prepare)(void *buf_priv);
+        void            (*finish)(void *buf_priv);
+
         void            *(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
                                 unsigned long size, int write);
         void            (*detach_dmabuf)(void *buf_priv);