From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
This prepares struct video_device for easier integration with vb2.
It also introduces a new lock that protects the vb2_queue. It is up
to the driver to use it or not. And the driver can associate an owner
filehandle with the queue to check whether queuing requests are
permitted for the calling filehandle.
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
drivers/media/video/v4l2-dev.c | 16 +++++-----------
drivers/media/video/v4l2-ioctl.c | 31 +++++++++++++++++++++++--------
include/media/v4l2-dev.h | 3 +++
include/media/v4l2-ioctl.h | 5 +++++
include/media/videobuf2-core.h | 13 +++++++++++++
5 files changed, 49 insertions(+), 19 deletions(-)
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 5c0bb18..1b34360 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -348,20 +348,14 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
int ret = -ENODEV;
if (vdev->fops->unlocked_ioctl) {
- bool locked = false;
+ struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
- if (vdev->lock) {
- /* always lock unless the cmd is marked as "don't use lock" */
- locked = !v4l2_is_known_ioctl(cmd) ||
- !test_bit(_IOC_NR(cmd), vdev->disable_locking);
-
- if (locked && mutex_lock_interruptible(vdev->lock))
- return -ERESTARTSYS;
- }
+ if (lock && mutex_lock_interruptible(lock))
+ return -ERESTARTSYS;
if (video_is_registered(vdev))
ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
- if (locked)
- mutex_unlock(vdev->lock);
+ if (lock)
+ mutex_unlock(lock);
} else if (vdev->fops->ioctl) {
/* This code path is a replacement for the BKL. It is a major
* hack but it will have to do for those drivers that are not
diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index efbb3db..95c9df0 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -27,6 +27,7 @@
#include <media/v4l2-event.h>
#include <media/v4l2-device.h>
#include <media/v4l2-chip-ident.h>
+#include <media/videobuf2-core.h>
/* Zero out the end of the struct pointed to by p. Everything after, but
* not including, the specified field is cleared. */
@@ -1816,6 +1817,8 @@ struct v4l2_ioctl_info {
#define INFO_FL_STD (1 << 2)
/* This is ioctl has its own function */
#define INFO_FL_FUNC (1 << 3)
+/* Queuing ioctl */
+#define INFO_FL_QUEUE (1 << 4)
/* Zero struct from after the field to the end */
#define INFO_FL_CLEAR(v4l2_struct, field) \
((offsetof(struct v4l2_struct, field) + \
@@ -1845,15 +1848,15 @@ static struct v4l2_ioctl_info v4l2_ioctls[] = {
IOCTL_INFO_FNC(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, INFO_FL_CLEAR(v4l2_fmtdesc, type)),
IOCTL_INFO_FNC(VIDIOC_G_FMT, v4l_g_fmt, v4l_print_format, INFO_FL_CLEAR(v4l2_format, type)),
IOCTL_INFO_FNC(VIDIOC_S_FMT, v4l_s_fmt, v4l_print_format, INFO_FL_PRIO),
- IOCTL_INFO_FNC(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO),
- IOCTL_INFO_FNC(VIDIOC_QUERYBUF, v4l_querybuf, v4l_print_buffer, INFO_FL_CLEAR(v4l2_buffer, length)),
+ IOCTL_INFO_FNC(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO | INFO_FL_QUEUE),
+ IOCTL_INFO_FNC(VIDIOC_QUERYBUF, v4l_querybuf, v4l_print_buffer, INFO_FL_QUEUE | INFO_FL_CLEAR(v4l2_buffer, length)),
IOCTL_INFO_STD(VIDIOC_G_FBUF, vidioc_g_fbuf, v4l_print_framebuffer, 0),
IOCTL_INFO_STD(VIDIOC_S_FBUF, vidioc_s_fbuf, v4l_print_framebuffer, INFO_FL_PRIO),
IOCTL_INFO_STD(VIDIOC_OVERLAY, vidioc_overlay, v4l_print_u32, INFO_FL_PRIO),
- IOCTL_INFO_FNC(VIDIOC_QBUF, v4l_qbuf, v4l_print_buffer, 0),
- IOCTL_INFO_FNC(VIDIOC_DQBUF, v4l_dqbuf, v4l_print_buffer, 0),
- IOCTL_INFO_FNC(VIDIOC_STREAMON, v4l_streamon, v4l_print_buftype, INFO_FL_PRIO),
- IOCTL_INFO_FNC(VIDIOC_STREAMOFF, v4l_streamoff, v4l_print_buftype, INFO_FL_PRIO),
+ IOCTL_INFO_FNC(VIDIOC_QBUF, v4l_qbuf, v4l_print_buffer, INFO_FL_QUEUE),
+ IOCTL_INFO_FNC(VIDIOC_DQBUF, v4l_dqbuf, v4l_print_buffer, INFO_FL_QUEUE),
+ IOCTL_INFO_FNC(VIDIOC_STREAMON, v4l_streamon, v4l_print_buftype, INFO_FL_PRIO | INFO_FL_QUEUE),
+ IOCTL_INFO_FNC(VIDIOC_STREAMOFF, v4l_streamoff, v4l_print_buftype, INFO_FL_PRIO | INFO_FL_QUEUE),
IOCTL_INFO_FNC(VIDIOC_G_PARM, v4l_g_parm, v4l_print_streamparm, INFO_FL_CLEAR(v4l2_streamparm, type)),
IOCTL_INFO_FNC(VIDIOC_S_PARM, v4l_s_parm, v4l_print_streamparm, INFO_FL_PRIO),
IOCTL_INFO_FNC(VIDIOC_G_STD, v4l_g_std, v4l_print_std, 0),
@@ -1917,8 +1920,8 @@ static struct v4l2_ioctl_info v4l2_ioctls[] = {
IOCTL_INFO_FNC(VIDIOC_DQEVENT, v4l_dqevent, v4l_print_event, 0),
IOCTL_INFO_FNC(VIDIOC_SUBSCRIBE_EVENT, v4l_subscribe_event, v4l_print_event_subscription, 0),
IOCTL_INFO_FNC(VIDIOC_UNSUBSCRIBE_EVENT, v4l_unsubscribe_event, v4l_print_event_subscription, 0),
- IOCTL_INFO_FNC(VIDIOC_CREATE_BUFS, v4l_create_bufs, v4l_print_create_buffers, INFO_FL_PRIO),
- IOCTL_INFO_FNC(VIDIOC_PREPARE_BUF, v4l_prepare_buf, v4l_print_buffer, 0),
+ IOCTL_INFO_FNC(VIDIOC_CREATE_BUFS, v4l_create_bufs, v4l_print_create_buffers, INFO_FL_PRIO | INFO_FL_QUEUE),
+ IOCTL_INFO_FNC(VIDIOC_PREPARE_BUF, v4l_prepare_buf, v4l_print_buffer, INFO_FL_QUEUE),
IOCTL_INFO_STD(VIDIOC_ENUM_DV_TIMINGS, vidioc_enum_dv_timings, v4l_print_enum_dv_timings, 0),
IOCTL_INFO_STD(VIDIOC_QUERY_DV_TIMINGS, vidioc_query_dv_timings, v4l_print_dv_timings, 0),
IOCTL_INFO_STD(VIDIOC_DV_TIMINGS_CAP, vidioc_dv_timings_cap, v4l_print_dv_timings_cap, 0),
@@ -1932,6 +1935,18 @@ bool v4l2_is_known_ioctl(unsigned int cmd)
return v4l2_ioctls[_IOC_NR(cmd)].ioctl == cmd;
}
+struct mutex *v4l2_ioctl_get_lock(struct video_device *vdev, unsigned cmd)
+{
+ if (_IOC_NR(cmd) >= V4L2_IOCTLS)
+ return vdev->lock;
+ if (test_bit(_IOC_NR(cmd), vdev->disable_locking))
+ return NULL;
+ if (vdev->queue && vdev->queue->lock &&
+ (v4l2_ioctls[_IOC_NR(cmd)].flags & INFO_FL_QUEUE))
+ return vdev->queue->lock;
+ return vdev->lock;
+}
+
/* Common ioctl debug function. This function can be used by
external ioctl messages as well as internal V4L ioctl */
void v4l_printk_ioctl(const char *prefix, unsigned int cmd)
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index a056e6e..5c416cd 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -100,6 +100,9 @@ struct video_device
/* Control handler associated with this device node. May be NULL. */
struct v4l2_ctrl_handler *ctrl_handler;
+ /* vb2_queue associated with this device node. May be NULL. */
+ struct vb2_queue *queue;
+
/* Priority state. If NULL, then v4l2_dev->prio will be used. */
struct v4l2_prio_state *prio;
diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index dfd984f..19e9352 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -304,6 +304,11 @@ extern int v4l2_video_std_construct(struct v4l2_standard *vs,
then do printk(KERN_DEBUG "%s: ", prefix) first. */
extern void v4l_printk_ioctl(const char *prefix, unsigned int cmd);
+/* Internal use only: get the mutex (if any) that we need to lock for the
+ given command. */
+struct video_device;
+extern struct mutex *v4l2_ioctl_get_lock(struct video_device *vdev, unsigned cmd);
+
/* names for fancy debug output */
extern const char *v4l2_field_names[];
extern const char *v4l2_type_names[];
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index a15d1f1..924e95e 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -244,12 +244,23 @@ struct vb2_ops {
void (*buf_queue)(struct vb2_buffer *vb);
};
+struct v4l2_fh;
+
/**
* struct vb2_queue - a videobuf queue
*
* @type: queue type (see V4L2_BUF_TYPE_* in linux/videodev2.h
* @io_modes: supported io methods (see vb2_io_modes enum)
* @io_flags: additional io flags (see vb2_fileio_flags enum)
+ * @lock: pointer to a mutex that protects the vb2_queue struct. The
+ * driver can set this to a mutex to let the v4l2 core serialize
+ * the queuing ioctls. If the driver wants to handle locking
+ * itself, then this should be set to NULL. This lock is not used
+ * by the videobuf2 core API.
+ * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
+ * that called reqbufs, create_buffers or started fileio.
+ * This field is not used by the videobuf2 core API, but it allows
+ * drivers to easily associate an owner filehandle with the queue.
* @ops: driver-specific callbacks
* @mem_ops: memory allocator specific callbacks
* @drv_priv: driver private data
@@ -273,6 +284,8 @@ struct vb2_queue {
enum v4l2_buf_type type;
unsigned int io_modes;
unsigned int io_flags;
+ struct mutex *lock;
+ struct v4l2_fh *owner;
const struct vb2_ops *ops;
const struct vb2_mem_ops *mem_ops;
--
1.7.10
--
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