1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * uvc_queue.c -- USB Video Class driver - Buffers management
4 *
5 * Copyright (C) 2005-2010
6 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7 */
8
9 #include <linux/atomic.h>
10 #include <linux/kernel.h>
11 #include <linux/mm.h>
12 #include <linux/list.h>
13 #include <linux/module.h>
14 #include <linux/usb.h>
15 #include <linux/videodev2.h>
16 #include <linux/vmalloc.h>
17 #include <linux/wait.h>
18 #include <media/videobuf2-v4l2.h>
19 #include <media/videobuf2-vmalloc.h>
20
21 #include "uvcvideo.h"
22
23 /* ------------------------------------------------------------------------
24 * Video buffers queue management.
25 *
26 * Video queues is initialized by uvc_queue_init(). The function performs
27 * basic initialization of the uvc_video_queue struct and never fails.
28 *
29 * Video buffers are managed by videobuf2. The driver uses a mutex to protect
30 * the videobuf2 queue operations by serializing calls to videobuf2 and a
31 * spinlock to protect the IRQ queue that holds the buffers to be processed by
32 * the driver.
33 */
34
uvc_vbuf_to_buffer(struct vb2_v4l2_buffer * buf)35 static inline struct uvc_buffer *uvc_vbuf_to_buffer(struct vb2_v4l2_buffer *buf)
36 {
37 return container_of(buf, struct uvc_buffer, buf);
38 }
39
40 /*
41 * Return all queued buffers to videobuf2 in the requested state.
42 *
43 * This function must be called with the queue spinlock held.
44 */
uvc_queue_return_buffers(struct uvc_video_queue * queue,enum uvc_buffer_state state)45 static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
46 enum uvc_buffer_state state)
47 {
48 enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
49 ? VB2_BUF_STATE_ERROR
50 : VB2_BUF_STATE_QUEUED;
51
52 while (!list_empty(&queue->irqqueue)) {
53 struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
54 struct uvc_buffer,
55 queue);
56 list_del(&buf->queue);
57 buf->state = state;
58 vb2_buffer_done(&buf->buf.vb2_buf, vb2_state);
59 }
60 }
61
62 /* -----------------------------------------------------------------------------
63 * videobuf2 queue operations
64 */
65
uvc_queue_setup(struct vb2_queue * vq,unsigned int * nbuffers,unsigned int * nplanes,unsigned int sizes[],struct device * alloc_devs[])66 static int uvc_queue_setup(struct vb2_queue *vq,
67 unsigned int *nbuffers, unsigned int *nplanes,
68 unsigned int sizes[], struct device *alloc_devs[])
69 {
70 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
71 struct uvc_streaming *stream;
72 unsigned int size;
73
74 switch (vq->type) {
75 case V4L2_BUF_TYPE_META_CAPTURE:
76 size = UVC_METADATA_BUF_SIZE;
77 break;
78
79 default:
80 stream = uvc_queue_to_stream(queue);
81 size = stream->ctrl.dwMaxVideoFrameSize;
82 break;
83 }
84
85 /*
86 * When called with plane sizes, validate them. The driver supports
87 * single planar formats only, and requires buffers to be large enough
88 * to store a complete frame.
89 */
90 if (*nplanes)
91 return *nplanes != 1 || sizes[0] < size ? -EINVAL : 0;
92
93 *nplanes = 1;
94 sizes[0] = size;
95 return 0;
96 }
97
uvc_buffer_prepare(struct vb2_buffer * vb)98 static int uvc_buffer_prepare(struct vb2_buffer *vb)
99 {
100 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
101 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
102 struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
103
104 if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
105 vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
106 uvc_dbg(uvc_queue_to_stream(queue)->dev, CAPTURE,
107 "[E] Bytes used out of bounds\n");
108 return -EINVAL;
109 }
110
111 if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
112 return -ENODEV;
113
114 buf->state = UVC_BUF_STATE_QUEUED;
115 buf->error = 0;
116 buf->mem = vb2_plane_vaddr(vb, 0);
117 buf->length = vb2_plane_size(vb, 0);
118 if (vb->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
119 buf->bytesused = 0;
120 else
121 buf->bytesused = vb2_get_plane_payload(vb, 0);
122
123 return 0;
124 }
125
uvc_buffer_queue(struct vb2_buffer * vb)126 static void uvc_buffer_queue(struct vb2_buffer *vb)
127 {
128 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
129 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
130 struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
131 unsigned long flags;
132
133 spin_lock_irqsave(&queue->irqlock, flags);
134 if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
135 kref_init(&buf->ref);
136 list_add_tail(&buf->queue, &queue->irqqueue);
137 } else {
138 /* If the device is disconnected return the buffer to userspace
139 * directly. The next QBUF call will fail with -ENODEV.
140 */
141 buf->state = UVC_BUF_STATE_ERROR;
142 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
143 }
144
145 spin_unlock_irqrestore(&queue->irqlock, flags);
146 }
147
uvc_buffer_finish(struct vb2_buffer * vb)148 static void uvc_buffer_finish(struct vb2_buffer *vb)
149 {
150 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
151 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
152 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
153 struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
154
155 if (vb->state == VB2_BUF_STATE_DONE)
156 uvc_video_clock_update(stream, vbuf, buf);
157 }
158
uvc_start_streaming(struct vb2_queue * vq,unsigned int count)159 static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
160 {
161 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
162 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
163 int ret;
164
165 lockdep_assert_irqs_enabled();
166
167 queue->buf_used = 0;
168
169 ret = uvc_video_start_streaming(stream);
170 if (ret == 0)
171 return 0;
172
173 spin_lock_irq(&queue->irqlock);
174 uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
175 spin_unlock_irq(&queue->irqlock);
176
177 return ret;
178 }
179
uvc_stop_streaming(struct vb2_queue * vq)180 static void uvc_stop_streaming(struct vb2_queue *vq)
181 {
182 struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
183
184 lockdep_assert_irqs_enabled();
185
186 if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
187 uvc_video_stop_streaming(uvc_queue_to_stream(queue));
188
189 spin_lock_irq(&queue->irqlock);
190 uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
191 spin_unlock_irq(&queue->irqlock);
192 }
193
194 static const struct vb2_ops uvc_queue_qops = {
195 .queue_setup = uvc_queue_setup,
196 .buf_prepare = uvc_buffer_prepare,
197 .buf_queue = uvc_buffer_queue,
198 .buf_finish = uvc_buffer_finish,
199 .wait_prepare = vb2_ops_wait_prepare,
200 .wait_finish = vb2_ops_wait_finish,
201 .start_streaming = uvc_start_streaming,
202 .stop_streaming = uvc_stop_streaming,
203 };
204
205 static const struct vb2_ops uvc_meta_queue_qops = {
206 .queue_setup = uvc_queue_setup,
207 .buf_prepare = uvc_buffer_prepare,
208 .buf_queue = uvc_buffer_queue,
209 .wait_prepare = vb2_ops_wait_prepare,
210 .wait_finish = vb2_ops_wait_finish,
211 .stop_streaming = uvc_stop_streaming,
212 };
213
uvc_queue_init(struct uvc_video_queue * queue,enum v4l2_buf_type type,int drop_corrupted)214 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
215 int drop_corrupted)
216 {
217 int ret;
218
219 queue->queue.type = type;
220 queue->queue.io_modes = VB2_MMAP | VB2_USERPTR;
221 queue->queue.drv_priv = queue;
222 queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
223 queue->queue.mem_ops = &vb2_vmalloc_memops;
224 queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
225 | V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
226 queue->queue.lock = &queue->mutex;
227
228 switch (type) {
229 case V4L2_BUF_TYPE_META_CAPTURE:
230 queue->queue.ops = &uvc_meta_queue_qops;
231 break;
232 default:
233 queue->queue.io_modes |= VB2_DMABUF;
234 queue->queue.ops = &uvc_queue_qops;
235 break;
236 }
237
238 ret = vb2_queue_init(&queue->queue);
239 if (ret)
240 return ret;
241
242 mutex_init(&queue->mutex);
243 spin_lock_init(&queue->irqlock);
244 INIT_LIST_HEAD(&queue->irqqueue);
245 queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
246
247 return 0;
248 }
249
uvc_queue_release(struct uvc_video_queue * queue)250 void uvc_queue_release(struct uvc_video_queue *queue)
251 {
252 mutex_lock(&queue->mutex);
253 vb2_queue_release(&queue->queue);
254 mutex_unlock(&queue->mutex);
255 }
256
257 /* -----------------------------------------------------------------------------
258 * V4L2 queue operations
259 */
260
uvc_request_buffers(struct uvc_video_queue * queue,struct v4l2_requestbuffers * rb)261 int uvc_request_buffers(struct uvc_video_queue *queue,
262 struct v4l2_requestbuffers *rb)
263 {
264 int ret;
265
266 mutex_lock(&queue->mutex);
267 ret = vb2_reqbufs(&queue->queue, rb);
268 mutex_unlock(&queue->mutex);
269
270 return ret ? ret : rb->count;
271 }
272
uvc_query_buffer(struct uvc_video_queue * queue,struct v4l2_buffer * buf)273 int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
274 {
275 int ret;
276
277 mutex_lock(&queue->mutex);
278 ret = vb2_querybuf(&queue->queue, buf);
279 mutex_unlock(&queue->mutex);
280
281 return ret;
282 }
283
uvc_create_buffers(struct uvc_video_queue * queue,struct v4l2_create_buffers * cb)284 int uvc_create_buffers(struct uvc_video_queue *queue,
285 struct v4l2_create_buffers *cb)
286 {
287 int ret;
288
289 mutex_lock(&queue->mutex);
290 ret = vb2_create_bufs(&queue->queue, cb);
291 mutex_unlock(&queue->mutex);
292
293 return ret;
294 }
295
uvc_queue_buffer(struct uvc_video_queue * queue,struct media_device * mdev,struct v4l2_buffer * buf)296 int uvc_queue_buffer(struct uvc_video_queue *queue,
297 struct media_device *mdev, struct v4l2_buffer *buf)
298 {
299 int ret;
300
301 mutex_lock(&queue->mutex);
302 ret = vb2_qbuf(&queue->queue, mdev, buf);
303 mutex_unlock(&queue->mutex);
304
305 return ret;
306 }
307
uvc_export_buffer(struct uvc_video_queue * queue,struct v4l2_exportbuffer * exp)308 int uvc_export_buffer(struct uvc_video_queue *queue,
309 struct v4l2_exportbuffer *exp)
310 {
311 int ret;
312
313 mutex_lock(&queue->mutex);
314 ret = vb2_expbuf(&queue->queue, exp);
315 mutex_unlock(&queue->mutex);
316
317 return ret;
318 }
319
uvc_dequeue_buffer(struct uvc_video_queue * queue,struct v4l2_buffer * buf,int nonblocking)320 int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
321 int nonblocking)
322 {
323 int ret;
324
325 mutex_lock(&queue->mutex);
326 ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
327 mutex_unlock(&queue->mutex);
328
329 return ret;
330 }
331
uvc_queue_streamon(struct uvc_video_queue * queue,enum v4l2_buf_type type)332 int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
333 {
334 int ret;
335
336 mutex_lock(&queue->mutex);
337 ret = vb2_streamon(&queue->queue, type);
338 mutex_unlock(&queue->mutex);
339
340 return ret;
341 }
342
uvc_queue_streamoff(struct uvc_video_queue * queue,enum v4l2_buf_type type)343 int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
344 {
345 int ret;
346
347 mutex_lock(&queue->mutex);
348 ret = vb2_streamoff(&queue->queue, type);
349 mutex_unlock(&queue->mutex);
350
351 return ret;
352 }
353
uvc_queue_mmap(struct uvc_video_queue * queue,struct vm_area_struct * vma)354 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
355 {
356 return vb2_mmap(&queue->queue, vma);
357 }
358
359 #ifndef CONFIG_MMU
uvc_queue_get_unmapped_area(struct uvc_video_queue * queue,unsigned long pgoff)360 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
361 unsigned long pgoff)
362 {
363 return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
364 }
365 #endif
366
uvc_queue_poll(struct uvc_video_queue * queue,struct file * file,poll_table * wait)367 __poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
368 poll_table *wait)
369 {
370 __poll_t ret;
371
372 mutex_lock(&queue->mutex);
373 ret = vb2_poll(&queue->queue, file, wait);
374 mutex_unlock(&queue->mutex);
375
376 return ret;
377 }
378
379 /* -----------------------------------------------------------------------------
380 *
381 */
382
383 /*
384 * Check if buffers have been allocated.
385 */
uvc_queue_allocated(struct uvc_video_queue * queue)386 int uvc_queue_allocated(struct uvc_video_queue *queue)
387 {
388 int allocated;
389
390 mutex_lock(&queue->mutex);
391 allocated = vb2_is_busy(&queue->queue);
392 mutex_unlock(&queue->mutex);
393
394 return allocated;
395 }
396
397 /*
398 * Cancel the video buffers queue.
399 *
400 * Cancelling the queue marks all buffers on the irq queue as erroneous,
401 * wakes them up and removes them from the queue.
402 *
403 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
404 * fail with -ENODEV.
405 *
406 * This function acquires the irq spinlock and can be called from interrupt
407 * context.
408 */
uvc_queue_cancel(struct uvc_video_queue * queue,int disconnect)409 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
410 {
411 unsigned long flags;
412
413 spin_lock_irqsave(&queue->irqlock, flags);
414 uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
415 /* This must be protected by the irqlock spinlock to avoid race
416 * conditions between uvc_buffer_queue and the disconnection event that
417 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
418 * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
419 * state outside the queue code.
420 */
421 if (disconnect)
422 queue->flags |= UVC_QUEUE_DISCONNECTED;
423 spin_unlock_irqrestore(&queue->irqlock, flags);
424 }
425
426 /*
427 * uvc_queue_get_current_buffer: Obtain the current working output buffer
428 *
429 * Buffers may span multiple packets, and even URBs, therefore the active buffer
430 * remains on the queue until the EOF marker.
431 */
432 static struct uvc_buffer *
__uvc_queue_get_current_buffer(struct uvc_video_queue * queue)433 __uvc_queue_get_current_buffer(struct uvc_video_queue *queue)
434 {
435 if (list_empty(&queue->irqqueue))
436 return NULL;
437
438 return list_first_entry(&queue->irqqueue, struct uvc_buffer, queue);
439 }
440
uvc_queue_get_current_buffer(struct uvc_video_queue * queue)441 struct uvc_buffer *uvc_queue_get_current_buffer(struct uvc_video_queue *queue)
442 {
443 struct uvc_buffer *nextbuf;
444 unsigned long flags;
445
446 spin_lock_irqsave(&queue->irqlock, flags);
447 nextbuf = __uvc_queue_get_current_buffer(queue);
448 spin_unlock_irqrestore(&queue->irqlock, flags);
449
450 return nextbuf;
451 }
452
453 /*
454 * uvc_queue_buffer_requeue: Requeue a buffer on our internal irqqueue
455 *
456 * Reuse a buffer through our internal queue without the need to 'prepare'.
457 * The buffer will be returned to userspace through the uvc_buffer_queue call if
458 * the device has been disconnected.
459 */
uvc_queue_buffer_requeue(struct uvc_video_queue * queue,struct uvc_buffer * buf)460 static void uvc_queue_buffer_requeue(struct uvc_video_queue *queue,
461 struct uvc_buffer *buf)
462 {
463 buf->error = 0;
464 buf->state = UVC_BUF_STATE_QUEUED;
465 buf->bytesused = 0;
466 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
467
468 uvc_buffer_queue(&buf->buf.vb2_buf);
469 }
470
uvc_queue_buffer_complete(struct kref * ref)471 static void uvc_queue_buffer_complete(struct kref *ref)
472 {
473 struct uvc_buffer *buf = container_of(ref, struct uvc_buffer, ref);
474 struct vb2_buffer *vb = &buf->buf.vb2_buf;
475 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
476
477 if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
478 uvc_queue_buffer_requeue(queue, buf);
479 return;
480 }
481
482 buf->state = buf->error ? UVC_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
483 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
484 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
485 }
486
487 /*
488 * Release a reference on the buffer. Complete the buffer when the last
489 * reference is released.
490 */
uvc_queue_buffer_release(struct uvc_buffer * buf)491 void uvc_queue_buffer_release(struct uvc_buffer *buf)
492 {
493 kref_put(&buf->ref, uvc_queue_buffer_complete);
494 }
495
496 /*
497 * Remove this buffer from the queue. Lifetime will persist while async actions
498 * are still running (if any), and uvc_queue_buffer_release will give the buffer
499 * back to VB2 when all users have completed.
500 */
uvc_queue_next_buffer(struct uvc_video_queue * queue,struct uvc_buffer * buf)501 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
502 struct uvc_buffer *buf)
503 {
504 struct uvc_buffer *nextbuf;
505 unsigned long flags;
506
507 spin_lock_irqsave(&queue->irqlock, flags);
508 list_del(&buf->queue);
509 nextbuf = __uvc_queue_get_current_buffer(queue);
510 spin_unlock_irqrestore(&queue->irqlock, flags);
511
512 uvc_queue_buffer_release(buf);
513
514 return nextbuf;
515 }
516