]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - drivers/media/v4l2-core/videobuf-core.c
projects / mirror_ubuntu-jammy-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
treewide: Use fallthrough pseudo-keyword
[mirror_ubuntu-jammy-kernel.git] / drivers / media / v4l2-core / videobuf-core.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * generic helper functions for handling video4linux capture buffers
4 *
5 * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org>
6 *
7 * Highly based on video-buf written originally by:
8 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
9 * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org>
10 * (c) 2006 Ted Walther and John Sokol
11 */
12
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/moduleparam.h>
16 #include <linux/mm.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/interrupt.h>
20
21 #include <media/videobuf-core.h>
22 #include <media/v4l2-common.h>
23
24 #define MAGIC_BUFFER 0x20070728
25 #define MAGIC_CHECK(is, should) \
26 do { \
27 if (unlikely((is) != (should))) { \
28 printk(KERN_ERR \
29 "magic mismatch: %x (expected %x)\n", \
30 is, should); \
31 BUG(); \
32 } \
33 } while (0)
34
35 static int debug;
36 module_param(debug, int, 0644);
37
38 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
39 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@kernel.org>");
40 MODULE_LICENSE("GPL");
41
42 #define dprintk(level, fmt, arg...) \
43 do { \
44 if (debug >= level) \
45 printk(KERN_DEBUG "vbuf: " fmt, ## arg); \
46 } while (0)
47
48 /* --------------------------------------------------------------------- */
49
50 #define CALL(q, f, arg...) \
51 ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
52 #define CALLPTR(q, f, arg...) \
53 ((q->int_ops->f) ? q->int_ops->f(arg) : NULL)
54
55 struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q)
56 {
57 struct videobuf_buffer *vb;
58
59 BUG_ON(q->msize < sizeof(*vb));
60
61 if (!q->int_ops || !q->int_ops->alloc_vb) {
62 printk(KERN_ERR "No specific ops defined!\n");
63 BUG();
64 }
65
66 vb = q->int_ops->alloc_vb(q->msize);
67 if (NULL != vb) {
68 init_waitqueue_head(&vb->done);
69 vb->magic = MAGIC_BUFFER;
70 }
71
72 return vb;
73 }
74 EXPORT_SYMBOL_GPL(videobuf_alloc_vb);
75
76 static int state_neither_active_nor_queued(struct videobuf_queue *q,
77 struct videobuf_buffer *vb)
78 {
79 unsigned long flags;
80 bool rc;
81
82 spin_lock_irqsave(q->irqlock, flags);
83 rc = vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED;
84 spin_unlock_irqrestore(q->irqlock, flags);
85 return rc;
86 };
87
88 int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
89 int non_blocking, int intr)
90 {
91 bool is_ext_locked;
92 int ret = 0;
93
94 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
95
96 if (non_blocking) {
97 if (state_neither_active_nor_queued(q, vb))
98 return 0;
99 return -EAGAIN;
100 }
101
102 is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock);
103
104 /* Release vdev lock to prevent this wait from blocking outside access to
105 the device. */
106 if (is_ext_locked)
107 mutex_unlock(q->ext_lock);
108 if (intr)
109 ret = wait_event_interruptible(vb->done,
110 state_neither_active_nor_queued(q, vb));
111 else
112 wait_event(vb->done, state_neither_active_nor_queued(q, vb));
113 /* Relock */
114 if (is_ext_locked)
115 mutex_lock(q->ext_lock);
116
117 return ret;
118 }
119 EXPORT_SYMBOL_GPL(videobuf_waiton);
120
121 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
122 struct v4l2_framebuffer *fbuf)
123 {
124 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
125 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
126
127 return CALL(q, iolock, q, vb, fbuf);
128 }
129 EXPORT_SYMBOL_GPL(videobuf_iolock);
130
131 void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
132 struct videobuf_buffer *buf)
133 {
134 if (q->int_ops->vaddr)
135 return q->int_ops->vaddr(buf);
136 return NULL;
137 }
138 EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr);
139
140 /* --------------------------------------------------------------------- */
141
142
143 void videobuf_queue_core_init(struct videobuf_queue *q,
144 const struct videobuf_queue_ops *ops,
145 struct device *dev,
146 spinlock_t *irqlock,
147 enum v4l2_buf_type type,
148 enum v4l2_field field,
149 unsigned int msize,
150 void *priv,
151 struct videobuf_qtype_ops *int_ops,
152 struct mutex *ext_lock)
153 {
154 BUG_ON(!q);
155 memset(q, 0, sizeof(*q));
156 q->irqlock = irqlock;
157 q->ext_lock = ext_lock;
158 q->dev = dev;
159 q->type = type;
160 q->field = field;
161 q->msize = msize;
162 q->ops = ops;
163 q->priv_data = priv;
164 q->int_ops = int_ops;
165
166 /* All buffer operations are mandatory */
167 BUG_ON(!q->ops->buf_setup);
168 BUG_ON(!q->ops->buf_prepare);
169 BUG_ON(!q->ops->buf_queue);
170 BUG_ON(!q->ops->buf_release);
171
172 /* Lock is mandatory for queue_cancel to work */
173 BUG_ON(!irqlock);
174
175 /* Having implementations for abstract methods are mandatory */
176 BUG_ON(!q->int_ops);
177
178 mutex_init(&q->vb_lock);
179 init_waitqueue_head(&q->wait);
180 INIT_LIST_HEAD(&q->stream);
181 }
182 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
183
184 /* Locking: Only usage in bttv unsafe find way to remove */
185 int videobuf_queue_is_busy(struct videobuf_queue *q)
186 {
187 int i;
188
189 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
190
191 if (q->streaming) {
192 dprintk(1, "busy: streaming active\n");
193 return 1;
194 }
195 if (q->reading) {
196 dprintk(1, "busy: pending read #1\n");
197 return 1;
198 }
199 if (q->read_buf) {
200 dprintk(1, "busy: pending read #2\n");
201 return 1;
202 }
203 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
204 if (NULL == q->bufs[i])
205 continue;
206 if (q->bufs[i]->map) {
207 dprintk(1, "busy: buffer #%d mapped\n", i);
208 return 1;
209 }
210 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
211 dprintk(1, "busy: buffer #%d queued\n", i);
212 return 1;
213 }
214 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
215 dprintk(1, "busy: buffer #%d active\n", i);
216 return 1;
217 }
218 }
219 return 0;
220 }
221 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
222
223 /*
224 * __videobuf_free() - free all the buffers and their control structures
225 *
226 * This function can only be called if streaming/reading is off, i.e. no buffers
227 * are under control of the driver.
228 */
229 /* Locking: Caller holds q->vb_lock */
230 static int __videobuf_free(struct videobuf_queue *q)
231 {
232 int i;
233
234 dprintk(1, "%s\n", __func__);
235 if (!q)
236 return 0;
237
238 if (q->streaming || q->reading) {
239 dprintk(1, "Cannot free buffers when streaming or reading\n");
240 return -EBUSY;
241 }
242
243 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
244
245 for (i = 0; i < VIDEO_MAX_FRAME; i++)
246 if (q->bufs[i] && q->bufs[i]->map) {
247 dprintk(1, "Cannot free mmapped buffers\n");
248 return -EBUSY;
249 }
250
251 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
252 if (NULL == q->bufs[i])
253 continue;
254 q->ops->buf_release(q, q->bufs[i]);
255 kfree(q->bufs[i]);
256 q->bufs[i] = NULL;
257 }
258
259 return 0;
260 }
261
262 /* Locking: Caller holds q->vb_lock */
263 void videobuf_queue_cancel(struct videobuf_queue *q)
264 {
265 unsigned long flags = 0;
266 int i;
267
268 q->streaming = 0;
269 q->reading = 0;
270 wake_up_interruptible_sync(&q->wait);
271
272 /* remove queued buffers from list */
273 spin_lock_irqsave(q->irqlock, flags);
274 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
275 if (NULL == q->bufs[i])
276 continue;
277 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
278 list_del(&q->bufs[i]->queue);
279 q->bufs[i]->state = VIDEOBUF_ERROR;
280 wake_up_all(&q->bufs[i]->done);
281 }
282 }
283 spin_unlock_irqrestore(q->irqlock, flags);
284
285 /* free all buffers + clear queue */
286 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
287 if (NULL == q->bufs[i])
288 continue;
289 q->ops->buf_release(q, q->bufs[i]);
290 }
291 INIT_LIST_HEAD(&q->stream);
292 }
293 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
294
295 /* --------------------------------------------------------------------- */
296
297 /* Locking: Caller holds q->vb_lock */
298 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
299 {
300 enum v4l2_field field = q->field;
301
302 BUG_ON(V4L2_FIELD_ANY == field);
303
304 if (V4L2_FIELD_ALTERNATE == field) {
305 if (V4L2_FIELD_TOP == q->last) {
306 field = V4L2_FIELD_BOTTOM;
307 q->last = V4L2_FIELD_BOTTOM;
308 } else {
309 field = V4L2_FIELD_TOP;
310 q->last = V4L2_FIELD_TOP;
311 }
312 }
313 return field;
314 }
315 EXPORT_SYMBOL_GPL(videobuf_next_field);
316
317 /* Locking: Caller holds q->vb_lock */
318 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
319 struct videobuf_buffer *vb, enum v4l2_buf_type type)
320 {
321 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
322 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
323
324 b->index = vb->i;
325 b->type = type;
326
327 b->memory = vb->memory;
328 switch (b->memory) {
329 case V4L2_MEMORY_MMAP:
330 b->m.offset = vb->boff;
331 b->length = vb->bsize;
332 break;
333 case V4L2_MEMORY_USERPTR:
334 b->m.userptr = vb->baddr;
335 b->length = vb->bsize;
336 break;
337 case V4L2_MEMORY_OVERLAY:
338 b->m.offset = vb->boff;
339 break;
340 case V4L2_MEMORY_DMABUF:
341 /* DMABUF is not handled in videobuf framework */
342 break;
343 }
344
345 b->flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
346 if (vb->map)
347 b->flags |= V4L2_BUF_FLAG_MAPPED;
348
349 switch (vb->state) {
350 case VIDEOBUF_PREPARED:
351 case VIDEOBUF_QUEUED:
352 case VIDEOBUF_ACTIVE:
353 b->flags |= V4L2_BUF_FLAG_QUEUED;
354 break;
355 case VIDEOBUF_ERROR:
356 b->flags |= V4L2_BUF_FLAG_ERROR;
357 fallthrough;
358 case VIDEOBUF_DONE:
359 b->flags |= V4L2_BUF_FLAG_DONE;
360 break;
361 case VIDEOBUF_NEEDS_INIT:
362 case VIDEOBUF_IDLE:
363 /* nothing */
364 break;
365 }
366
367 b->field = vb->field;
368 v4l2_buffer_set_timestamp(b, vb->ts);
369 b->bytesused = vb->size;
370 b->sequence = vb->field_count >> 1;
371 }
372
373 int videobuf_mmap_free(struct videobuf_queue *q)
374 {
375 int ret;
376 videobuf_queue_lock(q);
377 ret = __videobuf_free(q);
378 videobuf_queue_unlock(q);
379 return ret;
380 }
381 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
382
383 /* Locking: Caller holds q->vb_lock */
384 int __videobuf_mmap_setup(struct videobuf_queue *q,
385 unsigned int bcount, unsigned int bsize,
386 enum v4l2_memory memory)
387 {
388 unsigned int i;
389 int err;
390
391 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
392
393 err = __videobuf_free(q);
394 if (0 != err)
395 return err;
396
397 /* Allocate and initialize buffers */
398 for (i = 0; i < bcount; i++) {
399 q->bufs[i] = videobuf_alloc_vb(q);
400
401 if (NULL == q->bufs[i])
402 break;
403
404 q->bufs[i]->i = i;
405 q->bufs[i]->memory = memory;
406 q->bufs[i]->bsize = bsize;
407 switch (memory) {
408 case V4L2_MEMORY_MMAP:
409 q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
410 break;
411 case V4L2_MEMORY_USERPTR:
412 case V4L2_MEMORY_OVERLAY:
413 case V4L2_MEMORY_DMABUF:
414 /* nothing */
415 break;
416 }
417 }
418
419 if (!i)
420 return -ENOMEM;
421
422 dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
423
424 return i;
425 }
426 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
427
428 int videobuf_mmap_setup(struct videobuf_queue *q,
429 unsigned int bcount, unsigned int bsize,
430 enum v4l2_memory memory)
431 {
432 int ret;
433 videobuf_queue_lock(q);
434 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
435 videobuf_queue_unlock(q);
436 return ret;
437 }
438 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
439
440 int videobuf_reqbufs(struct videobuf_queue *q,
441 struct v4l2_requestbuffers *req)
442 {
443 unsigned int size, count;
444 int retval;
445
446 if (req->memory != V4L2_MEMORY_MMAP &&
447 req->memory != V4L2_MEMORY_USERPTR &&
448 req->memory != V4L2_MEMORY_OVERLAY) {
449 dprintk(1, "reqbufs: memory type invalid\n");
450 return -EINVAL;
451 }
452
453 videobuf_queue_lock(q);
454 if (req->type != q->type) {
455 dprintk(1, "reqbufs: queue type invalid\n");
456 retval = -EINVAL;
457 goto done;
458 }
459
460 if (q->streaming) {
461 dprintk(1, "reqbufs: streaming already exists\n");
462 retval = -EBUSY;
463 goto done;
464 }
465 if (!list_empty(&q->stream)) {
466 dprintk(1, "reqbufs: stream running\n");
467 retval = -EBUSY;
468 goto done;
469 }
470
471 if (req->count == 0) {
472 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
473 retval = __videobuf_free(q);
474 goto done;
475 }
476
477 count = req->count;
478 if (count > VIDEO_MAX_FRAME)
479 count = VIDEO_MAX_FRAME;
480 size = 0;
481 q->ops->buf_setup(q, &count, &size);
482 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
483 count, size,
484 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
485
486 retval = __videobuf_mmap_setup(q, count, size, req->memory);
487 if (retval < 0) {
488 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
489 goto done;
490 }
491
492 req->count = retval;
493 retval = 0;
494
495 done:
496 videobuf_queue_unlock(q);
497 return retval;
498 }
499 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
500
501 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
502 {
503 int ret = -EINVAL;
504
505 videobuf_queue_lock(q);
506 if (unlikely(b->type != q->type)) {
507 dprintk(1, "querybuf: Wrong type.\n");
508 goto done;
509 }
510 if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
511 dprintk(1, "querybuf: index out of range.\n");
512 goto done;
513 }
514 if (unlikely(NULL == q->bufs[b->index])) {
515 dprintk(1, "querybuf: buffer is null.\n");
516 goto done;
517 }
518
519 videobuf_status(q, b, q->bufs[b->index], q->type);
520
521 ret = 0;
522 done:
523 videobuf_queue_unlock(q);
524 return ret;
525 }
526 EXPORT_SYMBOL_GPL(videobuf_querybuf);
527
528 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
529 {
530 struct videobuf_buffer *buf;
531 enum v4l2_field field;
532 unsigned long flags = 0;
533 int retval;
534
535 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
536
537 if (b->memory == V4L2_MEMORY_MMAP)
538 mmap_read_lock(current->mm);
539
540 videobuf_queue_lock(q);
541 retval = -EBUSY;
542 if (q->reading) {
543 dprintk(1, "qbuf: Reading running...\n");
544 goto done;
545 }
546 retval = -EINVAL;
547 if (b->type != q->type) {
548 dprintk(1, "qbuf: Wrong type.\n");
549 goto done;
550 }
551 if (b->index >= VIDEO_MAX_FRAME) {
552 dprintk(1, "qbuf: index out of range.\n");
553 goto done;
554 }
555 buf = q->bufs[b->index];
556 if (NULL == buf) {
557 dprintk(1, "qbuf: buffer is null.\n");
558 goto done;
559 }
560 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
561 if (buf->memory != b->memory) {
562 dprintk(1, "qbuf: memory type is wrong.\n");
563 goto done;
564 }
565 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
566 dprintk(1, "qbuf: buffer is already queued or active.\n");
567 goto done;
568 }
569
570 switch (b->memory) {
571 case V4L2_MEMORY_MMAP:
572 if (0 == buf->baddr) {
573 dprintk(1, "qbuf: mmap requested but buffer addr is zero!\n");
574 goto done;
575 }
576 if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
577 || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
578 || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT
579 || q->type == V4L2_BUF_TYPE_SDR_OUTPUT) {
580 buf->size = b->bytesused;
581 buf->field = b->field;
582 buf->ts = v4l2_buffer_get_timestamp(b);
583 }
584 break;
585 case V4L2_MEMORY_USERPTR:
586 if (b->length < buf->bsize) {
587 dprintk(1, "qbuf: buffer length is not enough\n");
588 goto done;
589 }
590 if (VIDEOBUF_NEEDS_INIT != buf->state &&
591 buf->baddr != b->m.userptr)
592 q->ops->buf_release(q, buf);
593 buf->baddr = b->m.userptr;
594 break;
595 case V4L2_MEMORY_OVERLAY:
596 buf->boff = b->m.offset;
597 break;
598 default:
599 dprintk(1, "qbuf: wrong memory type\n");
600 goto done;
601 }
602
603 dprintk(1, "qbuf: requesting next field\n");
604 field = videobuf_next_field(q);
605 retval = q->ops->buf_prepare(q, buf, field);
606 if (0 != retval) {
607 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
608 goto done;
609 }
610
611 list_add_tail(&buf->stream, &q->stream);
612 if (q->streaming) {
613 spin_lock_irqsave(q->irqlock, flags);
614 q->ops->buf_queue(q, buf);
615 spin_unlock_irqrestore(q->irqlock, flags);
616 }
617 dprintk(1, "qbuf: succeeded\n");
618 retval = 0;
619 wake_up_interruptible_sync(&q->wait);
620
621 done:
622 videobuf_queue_unlock(q);
623
624 if (b->memory == V4L2_MEMORY_MMAP)
625 mmap_read_unlock(current->mm);
626
627 return retval;
628 }
629 EXPORT_SYMBOL_GPL(videobuf_qbuf);
630
631 /* Locking: Caller holds q->vb_lock */
632 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
633 {
634 int retval;
635
636 checks:
637 if (!q->streaming) {
638 dprintk(1, "next_buffer: Not streaming\n");
639 retval = -EINVAL;
640 goto done;
641 }
642
643 if (list_empty(&q->stream)) {
644 if (noblock) {
645 retval = -EAGAIN;
646 dprintk(2, "next_buffer: no buffers to dequeue\n");
647 goto done;
648 } else {
649 dprintk(2, "next_buffer: waiting on buffer\n");
650
651 /* Drop lock to avoid deadlock with qbuf */
652 videobuf_queue_unlock(q);
653
654 /* Checking list_empty and streaming is safe without
655 * locks because we goto checks to validate while
656 * holding locks before proceeding */
657 retval = wait_event_interruptible(q->wait,
658 !list_empty(&q->stream) || !q->streaming);
659 videobuf_queue_lock(q);
660
661 if (retval)
662 goto done;
663
664 goto checks;
665 }
666 }
667
668 retval = 0;
669
670 done:
671 return retval;
672 }
673
674 /* Locking: Caller holds q->vb_lock */
675 static int stream_next_buffer(struct videobuf_queue *q,
676 struct videobuf_buffer **vb, int nonblocking)
677 {
678 int retval;
679 struct videobuf_buffer *buf = NULL;
680
681 retval = stream_next_buffer_check_queue(q, nonblocking);
682 if (retval)
683 goto done;
684
685 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
686 retval = videobuf_waiton(q, buf, nonblocking, 1);
687 if (retval < 0)
688 goto done;
689
690 *vb = buf;
691 done:
692 return retval;
693 }
694
695 int videobuf_dqbuf(struct videobuf_queue *q,
696 struct v4l2_buffer *b, int nonblocking)
697 {
698 struct videobuf_buffer *buf = NULL;
699 int retval;
700
701 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
702
703 memset(b, 0, sizeof(*b));
704 videobuf_queue_lock(q);
705
706 retval = stream_next_buffer(q, &buf, nonblocking);
707 if (retval < 0) {
708 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
709 goto done;
710 }
711
712 switch (buf->state) {
713 case VIDEOBUF_ERROR:
714 dprintk(1, "dqbuf: state is error\n");
715 break;
716 case VIDEOBUF_DONE:
717 dprintk(1, "dqbuf: state is done\n");
718 break;
719 default:
720 dprintk(1, "dqbuf: state invalid\n");
721 retval = -EINVAL;
722 goto done;
723 }
724 CALL(q, sync, q, buf);
725 videobuf_status(q, b, buf, q->type);
726 list_del(&buf->stream);
727 buf->state = VIDEOBUF_IDLE;
728 b->flags &= ~V4L2_BUF_FLAG_DONE;
729 done:
730 videobuf_queue_unlock(q);
731 return retval;
732 }
733 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
734
735 int videobuf_streamon(struct videobuf_queue *q)
736 {
737 struct videobuf_buffer *buf;
738 unsigned long flags = 0;
739 int retval;
740
741 videobuf_queue_lock(q);
742 retval = -EBUSY;
743 if (q->reading)
744 goto done;
745 retval = 0;
746 if (q->streaming)
747 goto done;
748 q->streaming = 1;
749 spin_lock_irqsave(q->irqlock, flags);
750 list_for_each_entry(buf, &q->stream, stream)
751 if (buf->state == VIDEOBUF_PREPARED)
752 q->ops->buf_queue(q, buf);
753 spin_unlock_irqrestore(q->irqlock, flags);
754
755 wake_up_interruptible_sync(&q->wait);
756 done:
757 videobuf_queue_unlock(q);
758 return retval;
759 }
760 EXPORT_SYMBOL_GPL(videobuf_streamon);
761
762 /* Locking: Caller holds q->vb_lock */
763 static int __videobuf_streamoff(struct videobuf_queue *q)
764 {
765 if (!q->streaming)
766 return -EINVAL;
767
768 videobuf_queue_cancel(q);
769
770 return 0;
771 }
772
773 int videobuf_streamoff(struct videobuf_queue *q)
774 {
775 int retval;
776
777 videobuf_queue_lock(q);
778 retval = __videobuf_streamoff(q);
779 videobuf_queue_unlock(q);
780
781 return retval;
782 }
783 EXPORT_SYMBOL_GPL(videobuf_streamoff);
784
785 /* Locking: Caller holds q->vb_lock */
786 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
787 char __user *data,
788 size_t count, loff_t *ppos)
789 {
790 enum v4l2_field field;
791 unsigned long flags = 0;
792 int retval;
793
794 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
795
796 /* setup stuff */
797 q->read_buf = videobuf_alloc_vb(q);
798 if (NULL == q->read_buf)
799 return -ENOMEM;
800
801 q->read_buf->memory = V4L2_MEMORY_USERPTR;
802 q->read_buf->baddr = (unsigned long)data;
803 q->read_buf->bsize = count;
804
805 field = videobuf_next_field(q);
806 retval = q->ops->buf_prepare(q, q->read_buf, field);
807 if (0 != retval)
808 goto done;
809
810 /* start capture & wait */
811 spin_lock_irqsave(q->irqlock, flags);
812 q->ops->buf_queue(q, q->read_buf);
813 spin_unlock_irqrestore(q->irqlock, flags);
814 retval = videobuf_waiton(q, q->read_buf, 0, 0);
815 if (0 == retval) {
816 CALL(q, sync, q, q->read_buf);
817 if (VIDEOBUF_ERROR == q->read_buf->state)
818 retval = -EIO;
819 else
820 retval = q->read_buf->size;
821 }
822
823 done:
824 /* cleanup */
825 q->ops->buf_release(q, q->read_buf);
826 kfree(q->read_buf);
827 q->read_buf = NULL;
828 return retval;
829 }
830
831 static int __videobuf_copy_to_user(struct videobuf_queue *q,
832 struct videobuf_buffer *buf,
833 char __user *data, size_t count,
834 int nonblocking)
835 {
836 void *vaddr = CALLPTR(q, vaddr, buf);
837
838 /* copy to userspace */
839 if (count > buf->size - q->read_off)
840 count = buf->size - q->read_off;
841
842 if (copy_to_user(data, vaddr + q->read_off, count))
843 return -EFAULT;
844
845 return count;
846 }
847
848 static int __videobuf_copy_stream(struct videobuf_queue *q,
849 struct videobuf_buffer *buf,
850 char __user *data, size_t count, size_t pos,
851 int vbihack, int nonblocking)
852 {
853 unsigned int *fc = CALLPTR(q, vaddr, buf);
854
855 if (vbihack) {
856 /* dirty, undocumented hack -- pass the frame counter
857 * within the last four bytes of each vbi data block.
858 * We need that one to maintain backward compatibility
859 * to all vbi decoding software out there ... */
860 fc += (buf->size >> 2) - 1;
861 *fc = buf->field_count >> 1;
862 dprintk(1, "vbihack: %d\n", *fc);
863 }
864
865 /* copy stuff using the common method */
866 count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
867
868 if ((count == -EFAULT) && (pos == 0))
869 return -EFAULT;
870
871 return count;
872 }
873
874 ssize_t videobuf_read_one(struct videobuf_queue *q,
875 char __user *data, size_t count, loff_t *ppos,
876 int nonblocking)
877 {
878 enum v4l2_field field;
879 unsigned long flags = 0;
880 unsigned size = 0, nbufs = 1;
881 int retval;
882
883 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
884
885 videobuf_queue_lock(q);
886
887 q->ops->buf_setup(q, &nbufs, &size);
888
889 if (NULL == q->read_buf &&
890 count >= size &&
891 !nonblocking) {
892 retval = videobuf_read_zerocopy(q, data, count, ppos);
893 if (retval >= 0 || retval == -EIO)
894 /* ok, all done */
895 goto done;
896 /* fallback to kernel bounce buffer on failures */
897 }
898
899 if (NULL == q->read_buf) {
900 /* need to capture a new frame */
901 retval = -ENOMEM;
902 q->read_buf = videobuf_alloc_vb(q);
903
904 dprintk(1, "video alloc=0x%p\n", q->read_buf);
905 if (NULL == q->read_buf)
906 goto done;
907 q->read_buf->memory = V4L2_MEMORY_USERPTR;
908 q->read_buf->bsize = count; /* preferred size */
909 field = videobuf_next_field(q);
910 retval = q->ops->buf_prepare(q, q->read_buf, field);
911
912 if (0 != retval) {
913 kfree(q->read_buf);
914 q->read_buf = NULL;
915 goto done;
916 }
917
918 spin_lock_irqsave(q->irqlock, flags);
919 q->ops->buf_queue(q, q->read_buf);
920 spin_unlock_irqrestore(q->irqlock, flags);
921
922 q->read_off = 0;
923 }
924
925 /* wait until capture is done */
926 retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
927 if (0 != retval)
928 goto done;
929
930 CALL(q, sync, q, q->read_buf);
931
932 if (VIDEOBUF_ERROR == q->read_buf->state) {
933 /* catch I/O errors */
934 q->ops->buf_release(q, q->read_buf);
935 kfree(q->read_buf);
936 q->read_buf = NULL;
937 retval = -EIO;
938 goto done;
939 }
940
941 /* Copy to userspace */
942 retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
943 if (retval < 0)
944 goto done;
945
946 q->read_off += retval;
947 if (q->read_off == q->read_buf->size) {
948 /* all data copied, cleanup */
949 q->ops->buf_release(q, q->read_buf);
950 kfree(q->read_buf);
951 q->read_buf = NULL;
952 }
953
954 done:
955 videobuf_queue_unlock(q);
956 return retval;
957 }
958 EXPORT_SYMBOL_GPL(videobuf_read_one);
959
960 /* Locking: Caller holds q->vb_lock */
961 static int __videobuf_read_start(struct videobuf_queue *q)
962 {
963 enum v4l2_field field;
964 unsigned long flags = 0;
965 unsigned int count = 0, size = 0;
966 int err, i;
967
968 q->ops->buf_setup(q, &count, &size);
969 if (count < 2)
970 count = 2;
971 if (count > VIDEO_MAX_FRAME)
972 count = VIDEO_MAX_FRAME;
973 size = PAGE_ALIGN(size);
974
975 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
976 if (err < 0)
977 return err;
978
979 count = err;
980
981 for (i = 0; i < count; i++) {
982 field = videobuf_next_field(q);
983 err = q->ops->buf_prepare(q, q->bufs[i], field);
984 if (err)
985 return err;
986 list_add_tail(&q->bufs[i]->stream, &q->stream);
987 }
988 spin_lock_irqsave(q->irqlock, flags);
989 for (i = 0; i < count; i++)
990 q->ops->buf_queue(q, q->bufs[i]);
991 spin_unlock_irqrestore(q->irqlock, flags);
992 q->reading = 1;
993 return 0;
994 }
995
996 static void __videobuf_read_stop(struct videobuf_queue *q)
997 {
998 int i;
999
1000 videobuf_queue_cancel(q);
1001 __videobuf_free(q);
1002 INIT_LIST_HEAD(&q->stream);
1003 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1004 if (NULL == q->bufs[i])
1005 continue;
1006 kfree(q->bufs[i]);
1007 q->bufs[i] = NULL;
1008 }
1009 q->read_buf = NULL;
1010 }
1011
1012 int videobuf_read_start(struct videobuf_queue *q)
1013 {
1014 int rc;
1015
1016 videobuf_queue_lock(q);
1017 rc = __videobuf_read_start(q);
1018 videobuf_queue_unlock(q);
1019
1020 return rc;
1021 }
1022 EXPORT_SYMBOL_GPL(videobuf_read_start);
1023
1024 void videobuf_read_stop(struct videobuf_queue *q)
1025 {
1026 videobuf_queue_lock(q);
1027 __videobuf_read_stop(q);
1028 videobuf_queue_unlock(q);
1029 }
1030 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1031
1032 void videobuf_stop(struct videobuf_queue *q)
1033 {
1034 videobuf_queue_lock(q);
1035
1036 if (q->streaming)
1037 __videobuf_streamoff(q);
1038
1039 if (q->reading)
1040 __videobuf_read_stop(q);
1041
1042 videobuf_queue_unlock(q);
1043 }
1044 EXPORT_SYMBOL_GPL(videobuf_stop);
1045
1046 ssize_t videobuf_read_stream(struct videobuf_queue *q,
1047 char __user *data, size_t count, loff_t *ppos,
1048 int vbihack, int nonblocking)
1049 {
1050 int rc, retval;
1051 unsigned long flags = 0;
1052
1053 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1054
1055 dprintk(2, "%s\n", __func__);
1056 videobuf_queue_lock(q);
1057 retval = -EBUSY;
1058 if (q->streaming)
1059 goto done;
1060 if (!q->reading) {
1061 retval = __videobuf_read_start(q);
1062 if (retval < 0)
1063 goto done;
1064 }
1065
1066 retval = 0;
1067 while (count > 0) {
1068 /* get / wait for data */
1069 if (NULL == q->read_buf) {
1070 q->read_buf = list_entry(q->stream.next,
1071 struct videobuf_buffer,
1072 stream);
1073 list_del(&q->read_buf->stream);
1074 q->read_off = 0;
1075 }
1076 rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
1077 if (rc < 0) {
1078 if (0 == retval)
1079 retval = rc;
1080 break;
1081 }
1082
1083 if (q->read_buf->state == VIDEOBUF_DONE) {
1084 rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
1085 retval, vbihack, nonblocking);
1086 if (rc < 0) {
1087 retval = rc;
1088 break;
1089 }
1090 retval += rc;
1091 count -= rc;
1092 q->read_off += rc;
1093 } else {
1094 /* some error */
1095 q->read_off = q->read_buf->size;
1096 if (0 == retval)
1097 retval = -EIO;
1098 }
1099
1100 /* requeue buffer when done with copying */
1101 if (q->read_off == q->read_buf->size) {
1102 list_add_tail(&q->read_buf->stream,
1103 &q->stream);
1104 spin_lock_irqsave(q->irqlock, flags);
1105 q->ops->buf_queue(q, q->read_buf);
1106 spin_unlock_irqrestore(q->irqlock, flags);
1107 q->read_buf = NULL;
1108 }
1109 if (retval < 0)
1110 break;
1111 }
1112
1113 done:
1114 videobuf_queue_unlock(q);
1115 return retval;
1116 }
1117 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1118
1119 __poll_t videobuf_poll_stream(struct file *file,
1120 struct videobuf_queue *q,
1121 poll_table *wait)
1122 {
1123 __poll_t req_events = poll_requested_events(wait);
1124 struct videobuf_buffer *buf = NULL;
1125 __poll_t rc = 0;
1126
1127 videobuf_queue_lock(q);
1128 if (q->streaming) {
1129 if (!list_empty(&q->stream))
1130 buf = list_entry(q->stream.next,
1131 struct videobuf_buffer, stream);
1132 } else if (req_events & (EPOLLIN | EPOLLRDNORM)) {
1133 if (!q->reading)
1134 __videobuf_read_start(q);
1135 if (!q->reading) {
1136 rc = EPOLLERR;
1137 } else if (NULL == q->read_buf) {
1138 q->read_buf = list_entry(q->stream.next,
1139 struct videobuf_buffer,
1140 stream);
1141 list_del(&q->read_buf->stream);
1142 q->read_off = 0;
1143 }
1144 buf = q->read_buf;
1145 }
1146 if (buf)
1147 poll_wait(file, &buf->done, wait);
1148 else
1149 rc = EPOLLERR;
1150
1151 if (0 == rc) {
1152 if (buf->state == VIDEOBUF_DONE ||
1153 buf->state == VIDEOBUF_ERROR) {
1154 switch (q->type) {
1155 case V4L2_BUF_TYPE_VIDEO_OUTPUT:
1156 case V4L2_BUF_TYPE_VBI_OUTPUT:
1157 case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
1158 case V4L2_BUF_TYPE_SDR_OUTPUT:
1159 rc = EPOLLOUT | EPOLLWRNORM;
1160 break;
1161 default:
1162 rc = EPOLLIN | EPOLLRDNORM;
1163 break;
1164 }
1165 }
1166 }
1167 videobuf_queue_unlock(q);
1168 return rc;
1169 }
1170 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1171
1172 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1173 {
1174 int rc = -EINVAL;
1175 int i;
1176
1177 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1178
1179 if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
1180 dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
1181 return -EINVAL;
1182 }
1183
1184 videobuf_queue_lock(q);
1185 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1186 struct videobuf_buffer *buf = q->bufs[i];
1187
1188 if (buf && buf->memory == V4L2_MEMORY_MMAP &&
1189 buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
1190 rc = CALL(q, mmap_mapper, q, buf, vma);
1191 break;
1192 }
1193 }
1194 videobuf_queue_unlock(q);
1195
1196 return rc;
1197 }
1198 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
Ubuntu Jammy Linux kernel mirror