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