media: v4l2-core: push taking ioctl mutex down to ioctl handler

The ioctl serialization mutex (vdev->lock or q->lock for vb2 queues)
was taken at the highest level in v4l2-dev.c. This prevents more
fine-grained locking since at that level we cannot examine the ioctl
arguments, we can only do that after video_usercopy is called.

So push the locking down to __video_do_ioctl() and subdev_do_ioctl_lock().

This also allows us to make a few functions in v4l2-ioctl.c static and
video_usercopy() is no longer exported.

The locking scheme is not changed by this patch, just pushed down.

Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 0 insertions, 12 deletions

diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index a7b3f7c75d62..a8dbf5b54b5c 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -658,18 +658,6 @@ void v4l_printk_ioctl(const char *prefix, unsigned int cmd);
 
 struct video_device;
 
-
-/**
- * v4l2_ioctl_get_lock - get the mutex (if any) that it is need to lock for
- *	a given command.
- *
- * @vdev: Pointer to struct &video_device.
- * @cmd: Ioctl name.
- *
- * .. note:: Internal use only. Should not be used outside V4L2 core.
- */
-struct mutex *v4l2_ioctl_get_lock(struct video_device *vdev, unsigned int cmd);
-
 /* names for fancy debug output */
 extern const char *v4l2_field_names[];
 extern const char *v4l2_type_names[];