diff options
| -rw-r--r-- | drivers/media/video/videobuf2-core.c | 257 | ||||
| -rw-r--r-- | include/media/videobuf2-core.h | 41 |
2 files changed, 298 insertions, 0 deletions
diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c index ed38eb74835..4e0290ab507 100644 --- a/drivers/media/video/videobuf2-core.c +++ b/drivers/media/video/videobuf2-core.c @@ -2125,6 +2125,263 @@ size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count, } EXPORT_SYMBOL_GPL(vb2_write); + +/* + * The following functions are not part of the vb2 core API, but are helper + * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations + * and struct vb2_ops. + * They contain boilerplate code that most if not all drivers have to do + * and so they simplify the driver code. + */ + +/* The queue is busy if there is a owner and you are not that owner. */ +static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file) +{ + return vdev->queue->owner && vdev->queue->owner != file->private_data; +} + +/* vb2 ioctl helpers */ + +int vb2_ioctl_reqbufs(struct file *file, void *priv, + struct v4l2_requestbuffers *p) +{ + struct video_device *vdev = video_devdata(file); + int res = __verify_memory_type(vdev->queue, p->memory, p->type); + + if (res) + return res; + if (vb2_queue_is_busy(vdev, file)) + return -EBUSY; + res = __reqbufs(vdev->queue, p); + /* If count == 0, then the owner has released all buffers and he + is no longer owner of the queue. Otherwise we have a new owner. */ + if (res == 0) + vdev->queue->owner = p->count ? file->private_data : NULL; + return res; +} +EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs); + +int vb2_ioctl_create_bufs(struct file *file, void *priv, + struct v4l2_create_buffers *p) +{ + struct video_device *vdev = video_devdata(file); + int res = __verify_memory_type(vdev->queue, p->memory, p->format.type); + + p->index = vdev->queue->num_buffers; + /* If count == 0, then just check if memory and type are valid. + Any -EBUSY result from __verify_memory_type can be mapped to 0. */ + if (p->count == 0) + return res != -EBUSY ? res : 0; + if (res) + return res; + if (vb2_queue_is_busy(vdev, file)) + return -EBUSY; + res = __create_bufs(vdev->queue, p); + if (res == 0) + vdev->queue->owner = file->private_data; + return res; +} +EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs); + +int vb2_ioctl_prepare_buf(struct file *file, void *priv, + struct v4l2_buffer *p) +{ + struct video_device *vdev = video_devdata(file); + + if (vb2_queue_is_busy(vdev, file)) + return -EBUSY; + return vb2_prepare_buf(vdev->queue, p); +} +EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf); + +int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p) +{ + struct video_device *vdev = video_devdata(file); + + /* No need to call vb2_queue_is_busy(), anyone can query buffers. */ + return vb2_querybuf(vdev->queue, p); +} +EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf); + +int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p) +{ + struct video_device *vdev = video_devdata(file); + + if (vb2_queue_is_busy(vdev, file)) + return -EBUSY; + return vb2_qbuf(vdev->queue, p); +} +EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf); + +int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p) +{ + struct video_device *vdev = video_devdata(file); + + if (vb2_queue_is_busy(vdev, file)) + return -EBUSY; + return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK); +} +EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf); + +int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i) +{ + struct video_device *vdev = video_devdata(file); + + if (vb2_queue_is_busy(vdev, file)) + return -EBUSY; + return vb2_streamon(vdev->queue, i); +} +EXPORT_SYMBOL_GPL(vb2_ioctl_streamon); + +int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) +{ + struct video_device *vdev = video_devdata(file); + + if (vb2_queue_is_busy(vdev, file)) + return -EBUSY; + return vb2_streamoff(vdev->queue, i); +} +EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff); + +/* v4l2_file_operations helpers */ + +int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct video_device *vdev = video_devdata(file); + + return vb2_mmap(vdev->queue, vma); +} +EXPORT_SYMBOL_GPL(vb2_fop_mmap); + +int vb2_fop_release(struct file *file) +{ + struct video_device *vdev = video_devdata(file); + + if (file->private_data == vdev->queue->owner) { + vb2_queue_release(vdev->queue); + vdev->queue->owner = NULL; + } + return v4l2_fh_release(file); +} +EXPORT_SYMBOL_GPL(vb2_fop_release); + +ssize_t vb2_fop_write(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct video_device *vdev = video_devdata(file); + struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; + bool must_lock = !test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags) && lock; + int err = -EBUSY; + + if (must_lock && mutex_lock_interruptible(lock)) + return -ERESTARTSYS; + if (vb2_queue_is_busy(vdev, file)) + goto exit; + err = vb2_write(vdev->queue, buf, count, ppos, + file->f_flags & O_NONBLOCK); + if (err >= 0) + vdev->queue->owner = file->private_data; +exit: + if (must_lock) + mutex_unlock(lock); + return err; +} +EXPORT_SYMBOL_GPL(vb2_fop_write); + +ssize_t vb2_fop_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct video_device *vdev = video_devdata(file); + struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; + bool must_lock = !test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags) && vdev->lock; + int err = -EBUSY; + + if (must_lock && mutex_lock_interruptible(lock)) + return -ERESTARTSYS; + if (vb2_queue_is_busy(vdev, file)) + goto exit; + err = vb2_read(vdev->queue, buf, count, ppos, + file->f_flags & O_NONBLOCK); + if (err >= 0) + vdev->queue->owner = file->private_data; +exit: + if (must_lock) + mutex_unlock(lock); + return err; +} +EXPORT_SYMBOL_GPL(vb2_fop_read); + +unsigned int vb2_fop_poll(struct file *file, poll_table *wait) +{ + struct video_device *vdev = video_devdata(file); + struct vb2_queue *q = vdev->queue; + struct mutex *lock = q->lock ? q->lock : vdev->lock; + unsigned long req_events = poll_requested_events(wait); + unsigned res; + void *fileio; + /* Yuck. We really need to get rid of this flag asap. If it is + set, then the core took the serialization lock before calling + poll(). This is being phased out, but for now we have to handle + this case. */ + bool locked = test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags); + bool must_lock = false; + + /* Try to be smart: only lock if polling might start fileio, + otherwise locking will only introduce unwanted delays. */ + if (q->num_buffers == 0 && q->fileio == NULL) { + if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) && + (req_events & (POLLIN | POLLRDNORM))) + must_lock = true; + else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) && + (req_events & (POLLOUT | POLLWRNORM))) + must_lock = true; + } + + /* If locking is needed, but this helper doesn't know how, then you + shouldn't be using this helper but you should write your own. */ + WARN_ON(must_lock && !locked && !lock); + + if (must_lock && !locked && lock && mutex_lock_interruptible(lock)) + return POLLERR; + + fileio = q->fileio; + + res = vb2_poll(vdev->queue, file, wait); + + /* If fileio was started, then we have a new queue owner. */ + if (must_lock && !fileio && q->fileio) + q->owner = file->private_data; + if (must_lock && !locked && lock) + mutex_unlock(lock); + return res; +} +EXPORT_SYMBOL_GPL(vb2_fop_poll); + +#ifndef CONFIG_MMU +unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr, + unsigned long len, unsigned long pgoff, unsigned long flags) +{ + struct video_device *vdev = video_devdata(file); + + return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags); +} +EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area); +#endif + +/* vb2_ops helpers. Only use if vq->lock is non-NULL. */ + +void vb2_ops_wait_prepare(struct vb2_queue *vq) +{ + mutex_unlock(vq->lock); +} +EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare); + +void vb2_ops_wait_finish(struct vb2_queue *vq) +{ + mutex_lock(vq->lock); +} +EXPORT_SYMBOL_GPL(vb2_ops_wait_finish); + MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2"); MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski"); MODULE_LICENSE("GPL"); diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 924e95e0a0a..8dd9b6cc296 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -417,4 +417,45 @@ vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no) return 0; } +/* + * The following functions are not part of the vb2 core API, but are simple + * helper functions that you can use in your struct v4l2_file_operations, + * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock + * or video_device->lock is set, and they will set and test vb2_queue->owner + * to check if the calling filehandle is permitted to do the queuing operation. + */ + +/* struct v4l2_ioctl_ops helpers */ + +int vb2_ioctl_reqbufs(struct file *file, void *priv, + struct v4l2_requestbuffers *p); +int vb2_ioctl_create_bufs(struct file *file, void *priv, + struct v4l2_create_buffers *p); +int vb2_ioctl_prepare_buf(struct file *file, void *priv, + struct v4l2_buffer *p); +int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p); +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); + +/* struct v4l2_file_operations helpers */ + +int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma); +int vb2_fop_release(struct file *file); +ssize_t vb2_fop_write(struct file *file, char __user *buf, + size_t count, loff_t *ppos); +ssize_t vb2_fop_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos); +unsigned int vb2_fop_poll(struct file *file, poll_table *wait); +#ifndef CONFIG_MMU +unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr, + unsigned long len, unsigned long pgoff, unsigned long flags); +#endif + +/* struct vb2_ops helpers, only use if vq->lock is non-NULL. */ + +void vb2_ops_wait_prepare(struct vb2_queue *vq); +void vb2_ops_wait_finish(struct vb2_queue *vq); + #endif /* _MEDIA_VIDEOBUF2_CORE_H */ |