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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* uvc_queue.c -- USB Video Class driver - Buffers management
*
* Copyright (C) 2005-2010
* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
*/
#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-vmalloc.h>
#include "uvcvideo.h"
/* ------------------------------------------------------------------------
* Video buffers queue management.
*
* Video queues is initialized by uvc_queue_init(). The function performs
* basic initialization of the uvc_video_queue struct and never fails.
*
* Video buffers are managed by videobuf2. The driver uses a mutex to protect
* the videobuf2 queue operations by serializing calls to videobuf2 and a
* spinlock to protect the IRQ queue that holds the buffers to be processed by
* the driver.
*/
static inline struct uvc_streaming *
uvc_queue_to_stream(struct uvc_video_queue *queue)
{
return container_of(queue, struct uvc_streaming, queue);
}
static inline struct uvc_buffer *uvc_vbuf_to_buffer(struct vb2_v4l2_buffer *buf)
{
return container_of(buf, struct uvc_buffer, buf);
}
/*
* Return all queued buffers to videobuf2 in the requested state.
*
* This function must be called with the queue spinlock held.
*/
static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
enum uvc_buffer_state state)
{
enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
? VB2_BUF_STATE_ERROR
: VB2_BUF_STATE_QUEUED;
while (!list_empty(&queue->irqqueue)) {
struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
struct uvc_buffer,
queue);
list_del(&buf->queue);
buf->state = state;
vb2_buffer_done(&buf->buf.vb2_buf, vb2_state);
}
}
/* -----------------------------------------------------------------------------
* videobuf2 queue operations
*/
static int uvc_queue_setup(struct vb2_queue *vq,
unsigned int *nbuffers, unsigned int *nplanes,
unsigned int sizes[], struct device *alloc_devs[])
{
struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
struct uvc_streaming *stream;
unsigned int size;
switch (vq->type) {
case V4L2_BUF_TYPE_META_CAPTURE:
size = UVC_METADATA_BUF_SIZE;
break;
default:
stream = uvc_queue_to_stream(queue);
size = stream->ctrl.dwMaxVideoFrameSize;
break;
}
/*
* When called with plane sizes, validate them. The driver supports
* single planar formats only, and requires buffers to be large enough
* to store a complete frame.
*/
if (*nplanes)
return *nplanes != 1 || sizes[0] < size ? -EINVAL : 0;
*nplanes = 1;
sizes[0] = size;
return 0;
}
static int uvc_buffer_prepare(struct vb2_buffer *vb)
{
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
return -EINVAL;
}
if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
return -ENODEV;
buf->state = UVC_BUF_STATE_QUEUED;
buf->error = 0;
buf->mem = vb2_plane_vaddr(vb, 0);
buf->length = vb2_plane_size(vb, 0);
if (vb->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
buf->bytesused = 0;
else
buf->bytesused = vb2_get_plane_payload(vb, 0);
return 0;
}
static void uvc_buffer_queue(struct vb2_buffer *vb)
{
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
unsigned long flags;
spin_lock_irqsave(&queue->irqlock, flags);
if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
kref_init(&buf->ref);
list_add_tail(&buf->queue, &queue->irqqueue);
} else {
/* If the device is disconnected return the buffer to userspace
* directly. The next QBUF call will fail with -ENODEV.
*/
buf->state = UVC_BUF_STATE_ERROR;
vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
}
spin_unlock_irqrestore(&queue->irqlock, flags);
}
static void uvc_buffer_finish(struct vb2_buffer *vb)
{
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
struct uvc_streaming *stream = uvc_queue_to_stream(queue);
struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
if (vb->state == VB2_BUF_STATE_DONE)
uvc_video_clock_update(stream, vbuf, buf);
}
static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
{
struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
struct uvc_streaming *stream = uvc_queue_to_stream(queue);
int ret;
lockdep_assert_irqs_enabled();
queue->buf_used = 0;
ret = uvc_video_start_streaming(stream);
if (ret == 0)
return 0;
spin_lock_irq(&queue->irqlock);
uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
spin_unlock_irq(&queue->irqlock);
return ret;
}
static void uvc_stop_streaming(struct vb2_queue *vq)
{
struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
lockdep_assert_irqs_enabled();
if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
uvc_video_stop_streaming(uvc_queue_to_stream(queue));
spin_lock_irq(&queue->irqlock);
uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
spin_unlock_irq(&queue->irqlock);
}
static const struct vb2_ops uvc_queue_qops = {
.queue_setup = uvc_queue_setup,
.buf_prepare = uvc_buffer_prepare,
.buf_queue = uvc_buffer_queue,
.buf_finish = uvc_buffer_finish,
.wait_prepare = vb2_ops_wait_prepare,
.wait_finish = vb2_ops_wait_finish,
.start_streaming = uvc_start_streaming,
.stop_streaming = uvc_stop_streaming,
};
static const struct vb2_ops uvc_meta_queue_qops = {
.queue_setup = uvc_queue_setup,
.buf_prepare = uvc_buffer_prepare,
.buf_queue = uvc_buffer_queue,
.wait_prepare = vb2_ops_wait_prepare,
.wait_finish = vb2_ops_wait_finish,
.stop_streaming = uvc_stop_streaming,
};
int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
int drop_corrupted)
{
int ret;
queue->queue.type = type;
queue->queue.io_modes = VB2_MMAP | VB2_USERPTR;
queue->queue.drv_priv = queue;
queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
queue->queue.mem_ops = &vb2_vmalloc_memops;
queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
| V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
queue->queue.lock = &queue->mutex;
switch (type) {
case V4L2_BUF_TYPE_META_CAPTURE:
queue->queue.ops = &uvc_meta_queue_qops;
break;
default:
queue->queue.io_modes |= VB2_DMABUF;
queue->queue.ops = &uvc_queue_qops;
break;
}
ret = vb2_queue_init(&queue->queue);
if (ret)
return ret;
mutex_init(&queue->mutex);
spin_lock_init(&queue->irqlock);
INIT_LIST_HEAD(&queue->irqqueue);
queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
return 0;
}
void uvc_queue_release(struct uvc_video_queue *queue)
{
mutex_lock(&queue->mutex);
vb2_queue_release(&queue->queue);
mutex_unlock(&queue->mutex);
}
/* -----------------------------------------------------------------------------
* V4L2 queue operations
*/
int uvc_request_buffers(struct uvc_video_queue *queue,
struct v4l2_requestbuffers *rb)
{
int ret;
mutex_lock(&queue->mutex);
ret = vb2_reqbufs(&queue->queue, rb);
mutex_unlock(&queue->mutex);
return ret ? ret : rb->count;
}
int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
{
int ret;
mutex_lock(&queue->mutex);
ret = vb2_querybuf(&queue->queue, buf);
mutex_unlock(&queue->mutex);
return ret;
}
int uvc_create_buffers(struct uvc_video_queue *queue,
struct v4l2_create_buffers *cb)
{
int ret;
mutex_lock(&queue->mutex);
ret = vb2_create_bufs(&queue->queue, cb);
mutex_unlock(&queue->mutex);
return ret;
}
int uvc_queue_buffer(struct uvc_video_queue *queue,
struct media_device *mdev, struct v4l2_buffer *buf)
{
int ret;
mutex_lock(&queue->mutex);
ret = vb2_qbuf(&queue->queue, mdev, buf);
mutex_unlock(&queue->mutex);
return ret;
}
int uvc_export_buffer(struct uvc_video_queue *queue,
struct v4l2_exportbuffer *exp)
{
int ret;
mutex_lock(&queue->mutex);
ret = vb2_expbuf(&queue->queue, exp);
mutex_unlock(&queue->mutex);
return ret;
}
int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
int nonblocking)
{
int ret;
mutex_lock(&queue->mutex);
ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
mutex_unlock(&queue->mutex);
return ret;
}
int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
{
int ret;
mutex_lock(&queue->mutex);
ret = vb2_streamon(&queue->queue, type);
mutex_unlock(&queue->mutex);
return ret;
}
int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
{
int ret;
mutex_lock(&queue->mutex);
ret = vb2_streamoff(&queue->queue, type);
mutex_unlock(&queue->mutex);
return ret;
}
int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
{
return vb2_mmap(&queue->queue, vma);
}
#ifndef CONFIG_MMU
unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
unsigned long pgoff)
{
return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
}
#endif
__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
poll_table *wait)
{
__poll_t ret;
mutex_lock(&queue->mutex);
ret = vb2_poll(&queue->queue, file, wait);
mutex_unlock(&queue->mutex);
return ret;
}
/* -----------------------------------------------------------------------------
*
*/
/*
* Check if buffers have been allocated.
*/
int uvc_queue_allocated(struct uvc_video_queue *queue)
{
int allocated;
mutex_lock(&queue->mutex);
allocated = vb2_is_busy(&queue->queue);
mutex_unlock(&queue->mutex);
return allocated;
}
/*
* Cancel the video buffers queue.
*
* Cancelling the queue marks all buffers on the irq queue as erroneous,
* wakes them up and removes them from the queue.
*
* If the disconnect parameter is set, further calls to uvc_queue_buffer will
* fail with -ENODEV.
*
* This function acquires the irq spinlock and can be called from interrupt
* context.
*/
void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
{
unsigned long flags;
spin_lock_irqsave(&queue->irqlock, flags);
uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
/* This must be protected by the irqlock spinlock to avoid race
* conditions between uvc_buffer_queue and the disconnection event that
* could result in an interruptible wait in uvc_dequeue_buffer. Do not
* blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
* state outside the queue code.
*/
if (disconnect)
queue->flags |= UVC_QUEUE_DISCONNECTED;
spin_unlock_irqrestore(&queue->irqlock, flags);
}
/*
* uvc_queue_get_current_buffer: Obtain the current working output buffer
*
* Buffers may span multiple packets, and even URBs, therefore the active buffer
* remains on the queue until the EOF marker.
*/
static struct uvc_buffer *
__uvc_queue_get_current_buffer(struct uvc_video_queue *queue)
{
if (list_empty(&queue->irqqueue))
return NULL;
return list_first_entry(&queue->irqqueue, struct uvc_buffer, queue);
}
struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue)
{
struct uvc_buffer *nextbuf;
unsigned long flags;
spin_lock_irqsave(&queue->irqlock, flags);
nextbuf = __uvc_queue_get_current_buffer(queue);
spin_unlock_irqrestore(&queue->irqlock, flags);
return nextbuf;
}
/*
* uvc_queue_buffer_requeue: Requeue a buffer on our internal irqqueue
*
* Reuse a buffer through our internal queue without the need to 'prepare'.
* The buffer will be returned to userspace through the uvc_buffer_queue call if
* the device has been disconnected.
*/
static void uvc_queue_buffer_requeue(struct uvc_video_queue *queue,
struct uvc_buffer *buf)
{
buf->error = 0;
buf->state = UVC_BUF_STATE_QUEUED;
buf->bytesused = 0;
vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
uvc_buffer_queue(&buf->buf.vb2_buf);
}
static void uvc_queue_buffer_complete(struct kref *ref)
{
struct uvc_buffer *buf = container_of(ref, struct uvc_buffer, ref);
struct vb2_buffer *vb = &buf->buf.vb2_buf;
struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
uvc_queue_buffer_requeue(queue, buf);
return;
}
buf->state = buf->error ? UVC_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
}
/*
* Release a reference on the buffer. Complete the buffer when the last
* reference is released.
*/
void uvc_queue_buffer_release(struct uvc_buffer *buf)
{
kref_put(&buf->ref, uvc_queue_buffer_complete);
}
/*
* Remove this buffer from the queue. Lifetime will persist while async actions
* are still running (if any), and uvc_queue_buffer_release will give the buffer
* back to VB2 when all users have completed.
*/
struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
struct uvc_buffer *buf)
{
struct uvc_buffer *nextbuf;
unsigned long flags;
spin_lock_irqsave(&queue->irqlock, flags);
list_del(&buf->queue);
nextbuf = __uvc_queue_get_current_buffer(queue);
spin_unlock_irqrestore(&queue->irqlock, flags);
uvc_queue_buffer_release(buf);
return nextbuf;
}