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Commit 83ae7c5a authored by Tomasz Stanislawski's avatar Tomasz Stanislawski Committed by Mauro Carvalho Chehab
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[media] v4l: vb2: add buffer exporting via dmabuf 



This patch adds extension to videobuf2-core. It allow to export an mmap buffer
as a DMABUF file descriptor.

Signed-off-by: default avatarTomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Tested-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 19b6ef51

drivers/media/v4l2-core/v4l2-mem2mem.c

+13 −0
Original line number Diff line number Diff line
@@ -368,6 +368,19 @@ int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 
}

EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);



/**

 * v4l2_m2m_expbuf() - export a source or destination buffer, depending on

 * the type

 */

int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,

		  struct v4l2_exportbuffer *eb)

{

	struct vb2_queue *vq;



	vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);

	return vb2_expbuf(vq, eb);

}

EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);

/**

 * v4l2_m2m_streamon() - turn on streaming for a video queue

 */

drivers/media/v4l2-core/videobuf2-core.c

+83 −0
Original line number Diff line number Diff line
@@ -1750,6 +1750,79 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off, 
	return -EINVAL;

}



/**

 * 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;

	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;

	}



	if (eb->type != q->type) {

		dprintk(1, "qbuf: invalid buffer type\n");

		return -EINVAL;

	}



	if (eb->index >= q->num_buffers) {

		dprintk(1, "buffer index out of range\n");

		return -EINVAL;

	}



	vb = q->bufs[eb->index];



	if (eb->plane >= vb->num_planes) {

		dprintk(1, "buffer plane out of range\n");

		return -EINVAL;

	}



	vb_plane = &vb->planes[eb->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",

			eb->index, eb->plane);

		return -EINVAL;

	}



	ret = dma_buf_fd(dbuf, eb->flags);

	if (ret < 0) {

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

			eb->index, eb->plane, ret);

		dma_buf_put(dbuf);

		return ret;

	}



	dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",

		eb->index, eb->plane, ret);

	eb->fd = ret;



	return 0;

}

EXPORT_SYMBOL_GPL(vb2_expbuf);



/**

 * vb2_mmap() - map video buffers into application address space

 * @q:		videobuf2 queue
@@ -2456,6 +2529,16 @@ int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) 
}

EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);



int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)

{

	struct video_device *vdev = video_devdata(file);



	if (vb2_queue_is_busy(vdev, file))

		return -EBUSY;

	return vb2_expbuf(vdev->queue, p);

}

EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);



/* v4l2_file_operations helpers */



int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)

include/media/v4l2-mem2mem.h

+3 −0
Original line number Diff line number Diff line
@@ -111,6 +111,9 @@ int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, 
int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,

		   struct v4l2_buffer *buf);



int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,

		   struct v4l2_exportbuffer *eb);



int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,

		      enum v4l2_buf_type type);

int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,

include/media/videobuf2-core.h

+4 −0
Original line number Diff line number Diff line
@@ -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 __must_check 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);
@@ -472,6 +474,8 @@ int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p); 
int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p);

int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i);

int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i);

int vb2_ioctl_expbuf(struct file *file, void *priv,

	struct v4l2_exportbuffer *p);



/* struct v4l2_file_operations helpers */