This patch adds extension to videobuf2-core. It allow to export a mmap buffer
as a file descriptor.
Signed-off-by: Tomasz Stanislawski <t.stanislaws@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-mem2mem.c | 13 +++++
drivers/media/v4l2-core/videobuf2-core.c | 83 ++++++++++++++++++++++++++++++
include/media/v4l2-mem2mem.h | 3 ++
include/media/videobuf2-core.h | 4 ++
4 files changed, 103 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 3ac8358..9aa7cc7 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -369,6 +369,19 @@ 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
*/
int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
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 @@ 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;
+ 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 @@ 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)
diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h
index 131cc4a..7e82d2b 100644
--- a/include/media/v4l2-mem2mem.h
+++ b/include/media/v4l2-mem2mem.h
@@ -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,
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 24b9c90..9cfd4ee 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 __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 */
--
1.7.9.5
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