[media] media: vb2: Share code between vb2_prepare_buf and vb2_qbuf
The two operations are very similar, refactor most of the code in a
helper function.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index fb6802c..594c75e 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1231,6 +1231,101 @@
return ret;
}
+static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
+ const char *opname,
+ int (*handler)(struct vb2_queue *,
+ struct v4l2_buffer *,
+ struct vb2_buffer *))
+{
+ struct rw_semaphore *mmap_sem = NULL;
+ struct vb2_buffer *vb;
+ int ret;
+
+ /*
+ * In case of user pointer buffers vb2 allocators need to get direct
+ * access to userspace pages. This requires getting the mmap semaphore
+ * for read access in the current process structure. The same semaphore
+ * is taken before calling mmap operation, while both qbuf/prepare_buf
+ * and mmap are called by the driver or v4l2 core with the driver's lock
+ * held. To avoid an AB-BA deadlock (mmap_sem then driver's lock in mmap
+ * and driver's lock then mmap_sem in qbuf/prepare_buf) the videobuf2
+ * core releases the driver's lock, takes mmap_sem and then takes the
+ * driver's lock again.
+ *
+ * To avoid racing with other vb2 calls, which might be called after
+ * releasing the driver's lock, this operation is performed at the
+ * beginning of qbuf/prepare_buf processing. This way the queue status
+ * is consistent after getting the driver's lock back.
+ */
+ if (q->memory == V4L2_MEMORY_USERPTR) {
+ mmap_sem = ¤t->mm->mmap_sem;
+ call_qop(q, wait_prepare, q);
+ down_read(mmap_sem);
+ call_qop(q, wait_finish, q);
+ }
+
+ if (q->fileio) {
+ dprintk(1, "%s(): file io in progress\n", opname);
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ if (b->type != q->type) {
+ dprintk(1, "%s(): invalid buffer type\n", opname);
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ if (b->index >= q->num_buffers) {
+ dprintk(1, "%s(): buffer index out of range\n", opname);
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ vb = q->bufs[b->index];
+ if (NULL == vb) {
+ /* Should never happen */
+ dprintk(1, "%s(): buffer is NULL\n", opname);
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ if (b->memory != q->memory) {
+ dprintk(1, "%s(): invalid memory type\n", opname);
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ ret = __verify_planes_array(vb, b);
+ if (ret)
+ goto unlock;
+
+ ret = handler(q, b, vb);
+ if (ret)
+ goto unlock;
+
+ /* Fill buffer information for the userspace */
+ __fill_v4l2_buffer(vb, b);
+
+ dprintk(1, "%s() of buffer %d succeeded\n", opname, vb->v4l2_buf.index);
+unlock:
+ if (mmap_sem)
+ up_read(mmap_sem);
+ return ret;
+}
+
+static int __vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
+ struct vb2_buffer *vb)
+{
+ if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+ dprintk(1, "%s(): invalid buffer state %d\n", __func__,
+ vb->state);
+ return -EINVAL;
+ }
+
+ return __buf_prepare(vb, b);
+}
+
/**
* vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
* @q: videobuf2 queue
@@ -1248,87 +1343,44 @@
*/
int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
{
- struct rw_semaphore *mmap_sem = NULL;
- struct vb2_buffer *vb;
- int ret;
-
- /*
- * In case of user pointer buffers vb2 allocator needs to get direct
- * access to userspace pages. This requires getting read access on
- * mmap semaphore in the current process structure. The same
- * semaphore is taken before calling mmap operation, while both mmap
- * and prepare_buf are called by the driver or v4l2 core with driver's
- * lock held. To avoid a AB-BA deadlock (mmap_sem then driver's lock in
- * mmap and driver's lock then mmap_sem in prepare_buf) the videobuf2
- * core release driver's lock, takes mmap_sem and then takes again
- * driver's lock.
- *
- * To avoid race with other vb2 calls, which might be called after
- * releasing driver's lock, this operation is performed at the
- * beggining of prepare_buf processing. This way the queue status is
- * consistent after getting driver's lock back.
- */
- if (q->memory == V4L2_MEMORY_USERPTR) {
- mmap_sem = ¤t->mm->mmap_sem;
- call_qop(q, wait_prepare, q);
- down_read(mmap_sem);
- call_qop(q, wait_finish, q);
- }
-
- if (q->fileio) {
- dprintk(1, "%s(): file io in progress\n", __func__);
- ret = -EBUSY;
- goto unlock;
- }
-
- if (b->type != q->type) {
- dprintk(1, "%s(): invalid buffer type\n", __func__);
- ret = -EINVAL;
- goto unlock;
- }
-
- if (b->index >= q->num_buffers) {
- dprintk(1, "%s(): buffer index out of range\n", __func__);
- ret = -EINVAL;
- goto unlock;
- }
-
- vb = q->bufs[b->index];
- if (NULL == vb) {
- /* Should never happen */
- dprintk(1, "%s(): buffer is NULL\n", __func__);
- ret = -EINVAL;
- goto unlock;
- }
-
- if (b->memory != q->memory) {
- dprintk(1, "%s(): invalid memory type\n", __func__);
- ret = -EINVAL;
- goto unlock;
- }
-
- if (vb->state != VB2_BUF_STATE_DEQUEUED) {
- dprintk(1, "%s(): invalid buffer state %d\n", __func__, vb->state);
- ret = -EINVAL;
- goto unlock;
- }
- ret = __verify_planes_array(vb, b);
- if (ret < 0)
- goto unlock;
-
- ret = __buf_prepare(vb, b);
- if (ret < 0)
- goto unlock;
-
- __fill_v4l2_buffer(vb, b);
-
-unlock:
- if (mmap_sem)
- up_read(mmap_sem);
- return ret;
+ return vb2_queue_or_prepare_buf(q, b, "prepare_buf", __vb2_prepare_buf);
}
EXPORT_SYMBOL_GPL(vb2_prepare_buf);
+static int __vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b,
+ struct vb2_buffer *vb)
+{
+ int ret;
+
+ switch (vb->state) {
+ case VB2_BUF_STATE_DEQUEUED:
+ ret = __buf_prepare(vb, b);
+ if (ret)
+ return ret;
+ case VB2_BUF_STATE_PREPARED:
+ break;
+ default:
+ dprintk(1, "qbuf: buffer already in use\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Add to the queued buffers list, a buffer will stay on it until
+ * dequeued in dqbuf.
+ */
+ list_add_tail(&vb->queued_entry, &q->queued_list);
+ vb->state = VB2_BUF_STATE_QUEUED;
+
+ /*
+ * If already streaming, give the buffer to driver for processing.
+ * If not, the buffer will be given to driver on next streamon.
+ */
+ if (q->streaming)
+ __enqueue_in_driver(vb);
+
+ return 0;
+}
+
/**
* vb2_qbuf() - Queue a buffer from userspace
* @q: videobuf2 queue
@@ -1348,103 +1400,7 @@
*/
int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
- struct rw_semaphore *mmap_sem = NULL;
- struct vb2_buffer *vb;
- int ret = 0;
-
- /*
- * In case of user pointer buffers vb2 allocator needs to get direct
- * access to userspace pages. This requires getting read access on
- * mmap semaphore in the current process structure. The same
- * semaphore is taken before calling mmap operation, while both mmap
- * and qbuf are called by the driver or v4l2 core with driver's lock
- * held. To avoid a AB-BA deadlock (mmap_sem then driver's lock in
- * mmap and driver's lock then mmap_sem in qbuf) the videobuf2 core
- * release driver's lock, takes mmap_sem and then takes again driver's
- * lock.
- *
- * To avoid race with other vb2 calls, which might be called after
- * releasing driver's lock, this operation is performed at the
- * beggining of qbuf processing. This way the queue status is
- * consistent after getting driver's lock back.
- */
- if (q->memory == V4L2_MEMORY_USERPTR) {
- mmap_sem = ¤t->mm->mmap_sem;
- call_qop(q, wait_prepare, q);
- down_read(mmap_sem);
- call_qop(q, wait_finish, q);
- }
-
- if (q->fileio) {
- dprintk(1, "qbuf: file io in progress\n");
- ret = -EBUSY;
- goto unlock;
- }
-
- if (b->type != q->type) {
- dprintk(1, "qbuf: invalid buffer type\n");
- ret = -EINVAL;
- goto unlock;
- }
-
- if (b->index >= q->num_buffers) {
- dprintk(1, "qbuf: buffer index out of range\n");
- ret = -EINVAL;
- goto unlock;
- }
-
- vb = q->bufs[b->index];
- if (NULL == vb) {
- /* Should never happen */
- dprintk(1, "qbuf: buffer is NULL\n");
- ret = -EINVAL;
- goto unlock;
- }
-
- if (b->memory != q->memory) {
- dprintk(1, "qbuf: invalid memory type\n");
- ret = -EINVAL;
- goto unlock;
- }
- ret = __verify_planes_array(vb, b);
- if (ret)
- goto unlock;
-
- switch (vb->state) {
- case VB2_BUF_STATE_DEQUEUED:
- ret = __buf_prepare(vb, b);
- if (ret)
- goto unlock;
- case VB2_BUF_STATE_PREPARED:
- break;
- default:
- dprintk(1, "qbuf: buffer already in use\n");
- ret = -EINVAL;
- goto unlock;
- }
-
- /*
- * Add to the queued buffers list, a buffer will stay on it until
- * dequeued in dqbuf.
- */
- list_add_tail(&vb->queued_entry, &q->queued_list);
- vb->state = VB2_BUF_STATE_QUEUED;
-
- /*
- * If already streaming, give the buffer to driver for processing.
- * If not, the buffer will be given to driver on next streamon.
- */
- if (q->streaming)
- __enqueue_in_driver(vb);
-
- /* Fill buffer information for the userspace */
- __fill_v4l2_buffer(vb, b);
-
- dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
-unlock:
- if (mmap_sem)
- up_read(mmap_sem);
- return ret;
+ return vb2_queue_or_prepare_buf(q, b, "qbuf", __vb2_qbuf);
}
EXPORT_SYMBOL_GPL(vb2_qbuf);