On Tue August 14 2012 17:34:49 Tomasz Stanislawski wrote:
> This patch adds extension to videobuf2-core. It allow to export a mmap buffer
> as a file descriptor.
>
> Signed-off-by: Tomasz Stanislawski <t.stanisl...@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.p...@samsung.com>
> Acked-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> ---
> drivers/media/video/videobuf2-core.c | 67
> ++++++++++++++++++++++++++++++++++
> include/media/videobuf2-core.h | 2 +
> 2 files changed, 69 insertions(+)
>
> diff --git a/drivers/media/video/videobuf2-core.c
> b/drivers/media/video/videobuf2-core.c
> index aed21e4..61354ec 100644
> --- a/drivers/media/video/videobuf2-core.c
> +++ b/drivers/media/video/videobuf2-core.c
> @@ -1743,6 +1743,73 @@ static int __find_plane_by_offset(struct vb2_queue *q,
> unsigned long off,
> }
>
> /**
> + * vb2_expbuf() - Export a buffer as a file descriptor
> + * @q: videobuf2 queue
> + * @eb: export buffer structure passed from userspace to
> vidioc_expbuf
> + * handler in driver
> + *
> + * The return values from this function are intended to be directly returned
> + * from vidioc_expbuf handler in driver.
> + */
> +int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
> +{
> + struct vb2_buffer *vb = NULL;
> + struct vb2_plane *vb_plane;
> + unsigned int buffer, plane;
> + int ret;
> + struct dma_buf *dbuf;
> +
> + if (q->memory != V4L2_MEMORY_MMAP) {
> + dprintk(1, "Queue is not currently set up for mmap\n");
> + return -EINVAL;
> + }
> +
> + if (!q->mem_ops->get_dmabuf) {
> + dprintk(1, "Queue does not support DMA buffer exporting\n");
> + return -EINVAL;
> + }
> +
> + if (eb->flags & ~O_CLOEXEC) {
> + dprintk(1, "Queue does support only O_CLOEXEC flag\n");
> + return -EINVAL;
> + }
> +
> + /*
> + * Find the plane corresponding to the offset passed by userspace.
> + */
> + ret = __find_plane_by_offset(q, eb->mem_offset, &buffer, &plane);
> + if (ret) {
> + dprintk(1, "invalid offset %u\n", eb->mem_offset);
> + return ret;
> + }
> +
> + vb = q->bufs[buffer];
> + vb_plane = &vb->planes[plane];
> +
> + dbuf = call_memop(q, get_dmabuf, vb_plane->mem_priv);
> + if (IS_ERR_OR_NULL(dbuf)) {
> + dprintk(1, "Failed to export buffer %d, plane %d\n",
> + buffer, plane);
> + return -EINVAL;
> + }
> +
> + ret = dma_buf_fd(dbuf, eb->flags);
> + if (ret < 0) {
> + dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
> + buffer, plane, ret);
> + dma_buf_put(dbuf);
> + return ret;
> + }
> +
> + dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
> + buffer, plane, ret);
> + eb->fd = ret;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(vb2_expbuf);
> +
> +/**
> * vb2_mmap() - map video buffers into application address space
> * @q: videobuf2 queue
> * @vma: vma passed to the mmap file operation handler in the driver
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index c306fec..b034424 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -81,6 +81,7 @@ struct vb2_fileio_data;
> struct vb2_mem_ops {
> void *(*alloc)(void *alloc_ctx, unsigned long size);
> void (*put)(void *buf_priv);
> + struct dma_buf *(*get_dmabuf)(void *buf_priv);
>
> void *(*get_userptr)(void *alloc_ctx, unsigned long vaddr,
> unsigned long size, int write);
> @@ -363,6 +364,7 @@ int vb2_queue_init(struct vb2_queue *q);
> void vb2_queue_release(struct vb2_queue *q);
>
> int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b);
> +int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb);
> int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);
>
> int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
>
Please add a vb2_ioctl_expbuf helper function as well!
Regards,
Hans
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