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: Dave Stevenson <dave.stevenson@raspberrypi.org>
This commit is contained in:
Dave Stevenson
2018-10-29 17:57:45 +00:00
committed by Dom Cobley
parent cdec56b424
commit 59e77a0f86
2 changed files with 33 additions and 3 deletions

View File

@@ -2431,11 +2431,11 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long offset,
return 0;
}
int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
struct vb2_buffer *vb, unsigned int plane, unsigned int flags)
int vb2_core_expbuf_dmabuf(struct vb2_queue *q, unsigned int type,
struct vb2_buffer *vb, unsigned int plane,
unsigned int flags, struct dma_buf **dmabuf)
{
struct vb2_plane *vb_plane;
int ret;
struct dma_buf *dbuf;
if (q->memory != VB2_MEMORY_MMAP) {
@@ -2480,6 +2480,21 @@ 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,
struct vb2_buffer *vb, unsigned int plane, unsigned int flags)
{
struct dma_buf *dbuf;
int ret;
ret = vb2_core_expbuf_dmabuf(q, type, vb, plane, flags, &dbuf);
if (ret)
return ret;
ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
if (ret < 0) {
dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",

View File

@@ -967,6 +967,21 @@ 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,
struct vb2_buffer *vb, 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.