1 files changed, 517 insertions, 0 deletions
diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
new file mode 100644
index 000000000..16fa17bbd
--- /dev/null
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -0,0 +1,517 @@
+// 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_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_dbg(uvc_queue_to_stream(queue)->dev, 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;
+}