V4L/DVB: videobuf: prepare to make locking optional in videobuf
Currently videobuf uses the vb_lock mutex to lock its data structures.
But this locking will (optionally) move into the v4l2 core, which means
that in that case vb_lock shouldn't be used since the external lock is already
held.
Prepare for this by adding a pointer to such an external mutex and
don't lock if that pointer is set.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/v4l2-mem2mem.c b/drivers/media/video/v4l2-mem2mem.c
index f45f940..ac832a2 100644
--- a/drivers/media/video/v4l2-mem2mem.c
+++ b/drivers/media/video/v4l2-mem2mem.c
@@ -421,8 +421,8 @@
src_q = v4l2_m2m_get_src_vq(m2m_ctx);
dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
- mutex_lock(&src_q->vb_lock);
- mutex_lock(&dst_q->vb_lock);
+ videobuf_queue_lock(src_q);
+ videobuf_queue_lock(dst_q);
if (src_q->streaming && !list_empty(&src_q->stream))
src_vb = list_first_entry(&src_q->stream,
@@ -450,8 +450,8 @@
}
end:
- mutex_unlock(&dst_q->vb_lock);
- mutex_unlock(&src_q->vb_lock);
+ videobuf_queue_unlock(dst_q);
+ videobuf_queue_unlock(src_q);
return rc;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index ce1595b..2930665 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -350,9 +350,9 @@
int videobuf_mmap_free(struct videobuf_queue *q)
{
int ret;
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
ret = __videobuf_free(q);
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return ret;
}
EXPORT_SYMBOL_GPL(videobuf_mmap_free);
@@ -407,9 +407,9 @@
enum v4l2_memory memory)
{
int ret;
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return ret;
}
EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
@@ -432,7 +432,7 @@
return -EINVAL;
}
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
if (req->type != q->type) {
dprintk(1, "reqbufs: queue type invalid\n");
retval = -EINVAL;
@@ -469,7 +469,7 @@
retval = 0;
done:
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return retval;
}
EXPORT_SYMBOL_GPL(videobuf_reqbufs);
@@ -478,7 +478,7 @@
{
int ret = -EINVAL;
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
if (unlikely(b->type != q->type)) {
dprintk(1, "querybuf: Wrong type.\n");
goto done;
@@ -496,7 +496,7 @@
ret = 0;
done:
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return ret;
}
EXPORT_SYMBOL_GPL(videobuf_querybuf);
@@ -513,7 +513,7 @@
if (b->memory == V4L2_MEMORY_MMAP)
down_read(¤t->mm->mmap_sem);
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
retval = -EBUSY;
if (q->reading) {
dprintk(1, "qbuf: Reading running...\n");
@@ -605,7 +605,7 @@
wake_up_interruptible_sync(&q->wait);
done:
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
if (b->memory == V4L2_MEMORY_MMAP)
up_read(¤t->mm->mmap_sem);
@@ -635,14 +635,14 @@
dprintk(2, "next_buffer: waiting on buffer\n");
/* Drop lock to avoid deadlock with qbuf */
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
/* Checking list_empty and streaming is safe without
* locks because we goto checks to validate while
* holding locks before proceeding */
retval = wait_event_interruptible(q->wait,
!list_empty(&q->stream) || !q->streaming);
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
if (retval)
goto done;
@@ -687,7 +687,7 @@
MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
memset(b, 0, sizeof(*b));
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
retval = stream_next_buffer(q, &buf, nonblocking);
if (retval < 0) {
@@ -713,7 +713,7 @@
buf->state = VIDEOBUF_IDLE;
b->flags &= ~V4L2_BUF_FLAG_DONE;
done:
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return retval;
}
EXPORT_SYMBOL_GPL(videobuf_dqbuf);
@@ -724,7 +724,7 @@
unsigned long flags = 0;
int retval;
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
retval = -EBUSY;
if (q->reading)
goto done;
@@ -740,7 +740,7 @@
wake_up_interruptible_sync(&q->wait);
done:
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return retval;
}
EXPORT_SYMBOL_GPL(videobuf_streamon);
@@ -760,9 +760,9 @@
{
int retval;
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
retval = __videobuf_streamoff(q);
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return retval;
}
@@ -868,7 +868,7 @@
MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
q->ops->buf_setup(q, &nbufs, &size);
@@ -938,7 +938,7 @@
}
done:
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return retval;
}
EXPORT_SYMBOL_GPL(videobuf_read_one);
@@ -999,9 +999,9 @@
{
int rc;
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
rc = __videobuf_read_start(q);
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return rc;
}
@@ -1009,15 +1009,15 @@
void videobuf_read_stop(struct videobuf_queue *q)
{
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
__videobuf_read_stop(q);
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
}
EXPORT_SYMBOL_GPL(videobuf_read_stop);
void videobuf_stop(struct videobuf_queue *q)
{
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
if (q->streaming)
__videobuf_streamoff(q);
@@ -1025,7 +1025,7 @@
if (q->reading)
__videobuf_read_stop(q);
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
}
EXPORT_SYMBOL_GPL(videobuf_stop);
@@ -1039,7 +1039,7 @@
MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
dprintk(2, "%s\n", __func__);
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
retval = -EBUSY;
if (q->streaming)
goto done;
@@ -1097,7 +1097,7 @@
}
done:
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return retval;
}
EXPORT_SYMBOL_GPL(videobuf_read_stream);
@@ -1109,7 +1109,7 @@
struct videobuf_buffer *buf = NULL;
unsigned int rc = 0;
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
if (q->streaming) {
if (!list_empty(&q->stream))
buf = list_entry(q->stream.next,
@@ -1147,7 +1147,7 @@
}
}
}
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return rc;
}
EXPORT_SYMBOL_GPL(videobuf_poll_stream);
@@ -1164,7 +1164,7 @@
return -EINVAL;
}
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
struct videobuf_buffer *buf = q->bufs[i];
@@ -1174,7 +1174,7 @@
break;
}
}
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
return rc;
}
diff --git a/drivers/media/video/videobuf-dma-contig.c b/drivers/media/video/videobuf-dma-contig.c
index 6ff9e4b..047054f 100644
--- a/drivers/media/video/videobuf-dma-contig.c
+++ b/drivers/media/video/videobuf-dma-contig.c
@@ -63,7 +63,7 @@
struct videobuf_dma_contig_memory *mem;
dev_dbg(q->dev, "munmap %p q=%p\n", map, q);
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
/* We need first to cancel streams, before unmapping */
if (q->streaming)
@@ -103,7 +103,7 @@
kfree(map);
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
}
}
diff --git a/drivers/media/video/videobuf-dma-sg.c b/drivers/media/video/videobuf-dma-sg.c
index 2ad0bc2..515ae88 100644
--- a/drivers/media/video/videobuf-dma-sg.c
+++ b/drivers/media/video/videobuf-dma-sg.c
@@ -358,7 +358,7 @@
map->count--;
if (0 == map->count) {
dprintk(1, "munmap %p q=%p\n", map, q);
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
if (NULL == q->bufs[i])
continue;
@@ -374,7 +374,7 @@
q->bufs[i]->baddr = 0;
q->ops->buf_release(q, q->bufs[i]);
}
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
kfree(map);
}
return;
diff --git a/drivers/media/video/videobuf-vmalloc.c b/drivers/media/video/videobuf-vmalloc.c
index e7fe31d..91348b3 100644
--- a/drivers/media/video/videobuf-vmalloc.c
+++ b/drivers/media/video/videobuf-vmalloc.c
@@ -75,7 +75,7 @@
struct videobuf_vmalloc_memory *mem;
dprintk(1, "munmap %p q=%p\n", map, q);
- mutex_lock(&q->vb_lock);
+ videobuf_queue_lock(q);
/* We need first to cancel streams, before unmapping */
if (q->streaming)
@@ -114,7 +114,7 @@
kfree(map);
- mutex_unlock(&q->vb_lock);
+ videobuf_queue_unlock(q);
}
return;
diff --git a/include/media/videobuf-core.h b/include/media/videobuf-core.h
index f2c41ce..f5eb2cb 100644
--- a/include/media/videobuf-core.h
+++ b/include/media/videobuf-core.h
@@ -139,6 +139,7 @@
struct videobuf_queue {
struct mutex vb_lock;
+ struct mutex *ext_lock;
spinlock_t *irqlock;
struct device *dev;
@@ -167,6 +168,18 @@
void *priv_data;
};
+static inline void videobuf_queue_lock(struct videobuf_queue *q)
+{
+ if (!q->ext_lock)
+ mutex_lock(&q->vb_lock);
+}
+
+static inline void videobuf_queue_unlock(struct videobuf_queue *q)
+{
+ if (!q->ext_lock)
+ mutex_unlock(&q->vb_lock);
+}
+
int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
struct v4l2_framebuffer *fbuf);