[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: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@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>
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 613dea1..9f81be2 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1751,6 +1751,79 @@
}
/**
+ * 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
* @vma: vma passed to the mmap file operation handler in the driver
@@ -2456,6 +2529,16 @@
}
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)