Commit f4d2776a authored by Dave Stevenson's avatar Dave Stevenson Committed by popcornmix
Browse files

media: videobuf2: Allow exporting of a struct dmabuf 



videobuf2 only allowed exporting a dmabuf as a file descriptor,
but there are instances where having the struct dma_buf is
useful within the kernel.

Split the current implementation into two, one step which
exports a struct dma_buf, and the second which converts that
into an fd.

Signed-off-by: default avatarDave Stevenson <dave.stevenson@raspberrypi.org>
parent 33586072

drivers/media/common/videobuf2/videobuf2-core.c

+18 −3
Original line number Diff line number Diff line
@@ -1831,12 +1831,12 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off, 
	return -EINVAL;

}



int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,

		unsigned int index, unsigned int plane, unsigned int flags)

int vb2_core_expbuf_dmabuf(struct vb2_queue *q, unsigned int type,

			   unsigned int index, unsigned int plane,

			   unsigned int flags, struct dma_buf **dmabuf)

{

	struct vb2_buffer *vb = NULL;

	struct vb2_plane *vb_plane;

	int ret;

	struct dma_buf *dbuf;



	if (q->memory != VB2_MEMORY_MMAP) {
@@ -1886,6 +1886,21 @@ int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, 
		return -EINVAL;

	}



	*dmabuf = dbuf;

	return 0;

}

EXPORT_SYMBOL_GPL(vb2_core_expbuf_dmabuf);



int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,

		    unsigned int index, unsigned int plane, unsigned int flags)

{

	struct dma_buf *dbuf;

	int ret;



	ret = vb2_core_expbuf_dmabuf(q, type, index, plane, flags, &dbuf);

	if (ret)

		return ret;



	ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);

	if (ret < 0) {

		dprintk(3, "buffer %d, plane %d failed to export (%d)\n",

include/media/videobuf2-core.h

+15 −0
Original line number Diff line number Diff line
@@ -823,6 +823,21 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type); 
 */

int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);



/**

 * vb2_core_expbuf_dmabuf() - Export a buffer as a dma_buf structure

 * @q:         videobuf2 queue

 * @type:      buffer type

 * @index:     id number of the buffer

 * @plane:     index of the plane to be exported, 0 for single plane queues

 * @flags:     flags for newly created file, currently only O_CLOEXEC is

 *             supported, refer to manual of open syscall for more details

 * @dmabuf:    Returns the dmabuf pointer

 *

 */

int vb2_core_expbuf_dmabuf(struct vb2_queue *q, unsigned int type,

			   unsigned int index, unsigned int plane,

			   unsigned int flags, struct dma_buf **dmabuf);



/**

 * vb2_core_expbuf() - Export a buffer as a file descriptor.

 * @q:		pointer to &struct vb2_queue with videobuf2 queue.