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
23 #define MAGIC_BUFFER 0x20070728
24 #define MAGIC_CHECK(is, should) \
25 do { \
26 if (unlikely((is) != (should))) { \
27 printk(KERN_ERR \
28 "magic mismatch: %x (expected %x)\n", \
29 is, should); \
30 BUG(); \
31 } \
32 } while (0)
33
34 static int debug;
35 module_param(debug, int, 0644);
36
37 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
38 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@kernel.org>");
39 MODULE_LICENSE("GPL");
40
41 #define dprintk(level, fmt, arg...) \
42 do { \
43 if (debug >= level) \
44 printk(KERN_DEBUG "vbuf: " fmt, ## arg); \
45 } while (0)
46
47 /* --------------------------------------------------------------------- */
48
49 #define CALL(q, f, arg...) \
50 ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
51 #define CALLPTR(q, f, arg...) \
52 ((q->int_ops->f) ? q->int_ops->f(arg) : NULL)
53
videobuf_alloc_vb(struct videobuf_queue * q)54 struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q)
55 {
56 struct videobuf_buffer *vb;
57
58 BUG_ON(q->msize < sizeof(*vb));
59
60 if (!q->int_ops || !q->int_ops->alloc_vb) {
61 printk(KERN_ERR "No specific ops defined!\n");
62 BUG();
63 }
64
65 vb = q->int_ops->alloc_vb(q->msize);
66 if (NULL != vb) {
67 init_waitqueue_head(&vb->done);
68 vb->magic = MAGIC_BUFFER;
69 }
70
71 return vb;
72 }
73 EXPORT_SYMBOL_GPL(videobuf_alloc_vb);
74
state_neither_active_nor_queued(struct videobuf_queue * q,struct videobuf_buffer * vb)75 static int state_neither_active_nor_queued(struct videobuf_queue *q,
76 struct videobuf_buffer *vb)
77 {
78 unsigned long flags;
79 bool rc;
80
81 spin_lock_irqsave(q->irqlock, flags);
82 rc = vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED;
83 spin_unlock_irqrestore(q->irqlock, flags);
84 return rc;
85 };
86
videobuf_waiton(struct videobuf_queue * q,struct videobuf_buffer * vb,int non_blocking,int intr)87 int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
88 int non_blocking, int intr)
89 {
90 bool is_ext_locked;
91 int ret = 0;
92
93 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
94
95 if (non_blocking) {
96 if (state_neither_active_nor_queued(q, vb))
97 return 0;
98 return -EAGAIN;
99 }
100
101 is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock);
102
103 /* Release vdev lock to prevent this wait from blocking outside access to
104 the device. */
105 if (is_ext_locked)
106 mutex_unlock(q->ext_lock);
107 if (intr)
108 ret = wait_event_interruptible(vb->done,
109 state_neither_active_nor_queued(q, vb));
110 else
111 wait_event(vb->done, state_neither_active_nor_queued(q, vb));
112 /* Relock */
113 if (is_ext_locked)
114 mutex_lock(q->ext_lock);
115
116 return ret;
117 }
118 EXPORT_SYMBOL_GPL(videobuf_waiton);
119
videobuf_iolock(struct videobuf_queue * q,struct videobuf_buffer * vb,struct v4l2_framebuffer * fbuf)120 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
121 struct v4l2_framebuffer *fbuf)
122 {
123 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
124 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
125
126 return CALL(q, iolock, q, vb, fbuf);
127 }
128 EXPORT_SYMBOL_GPL(videobuf_iolock);
129
videobuf_queue_to_vaddr(struct videobuf_queue * q,struct videobuf_buffer * buf)130 void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
131 struct videobuf_buffer *buf)
132 {
133 if (q->int_ops->vaddr)
134 return q->int_ops->vaddr(buf);
135 return NULL;
136 }
137 EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr);
138
139 /* --------------------------------------------------------------------- */
140
141
videobuf_queue_core_init(struct videobuf_queue * q,const struct videobuf_queue_ops * ops,struct device * dev,spinlock_t * irqlock,enum v4l2_buf_type type,enum v4l2_field field,unsigned int msize,void * priv,struct videobuf_qtype_ops * int_ops,struct mutex * ext_lock)142 void videobuf_queue_core_init(struct videobuf_queue *q,
143 const struct videobuf_queue_ops *ops,
144 struct device *dev,
145 spinlock_t *irqlock,
146 enum v4l2_buf_type type,
147 enum v4l2_field field,
148 unsigned int msize,
149 void *priv,
150 struct videobuf_qtype_ops *int_ops,
151 struct mutex *ext_lock)
152 {
153 BUG_ON(!q);
154 memset(q, 0, sizeof(*q));
155 q->irqlock = irqlock;
156 q->ext_lock = ext_lock;
157 q->dev = dev;
158 q->type = type;
159 q->field = field;
160 q->msize = msize;
161 q->ops = ops;
162 q->priv_data = priv;
163 q->int_ops = int_ops;
164
165 /* All buffer operations are mandatory */
166 BUG_ON(!q->ops->buf_setup);
167 BUG_ON(!q->ops->buf_prepare);
168 BUG_ON(!q->ops->buf_queue);
169 BUG_ON(!q->ops->buf_release);
170
171 /* Lock is mandatory for queue_cancel to work */
172 BUG_ON(!irqlock);
173
174 /* Having implementations for abstract methods are mandatory */
175 BUG_ON(!q->int_ops);
176
177 mutex_init(&q->vb_lock);
178 init_waitqueue_head(&q->wait);
179 INIT_LIST_HEAD(&q->stream);
180 }
181 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
182
183 /* Locking: Only usage in bttv unsafe find way to remove */
videobuf_queue_is_busy(struct videobuf_queue * q)184 int videobuf_queue_is_busy(struct videobuf_queue *q)
185 {
186 int i;
187
188 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
189
190 if (q->streaming) {
191 dprintk(1, "busy: streaming active\n");
192 return 1;
193 }
194 if (q->reading) {
195 dprintk(1, "busy: pending read #1\n");
196 return 1;
197 }
198 if (q->read_buf) {
199 dprintk(1, "busy: pending read #2\n");
200 return 1;
201 }
202 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
203 if (NULL == q->bufs[i])
204 continue;
205 if (q->bufs[i]->map) {
206 dprintk(1, "busy: buffer #%d mapped\n", i);
207 return 1;
208 }
209 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
210 dprintk(1, "busy: buffer #%d queued\n", i);
211 return 1;
212 }
213 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
214 dprintk(1, "busy: buffer #%d active\n", i);
215 return 1;
216 }
217 }
218 return 0;
219 }
220 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
221
222 /*
223 * __videobuf_free() - free all the buffers and their control structures
224 *
225 * This function can only be called if streaming/reading is off, i.e. no buffers
226 * are under control of the driver.
227 */
228 /* Locking: Caller holds q->vb_lock */
__videobuf_free(struct videobuf_queue * q)229 static int __videobuf_free(struct videobuf_queue *q)
230 {
231 int i;
232
233 dprintk(1, "%s\n", __func__);
234 if (!q)
235 return 0;
236
237 if (q->streaming || q->reading) {
238 dprintk(1, "Cannot free buffers when streaming or reading\n");
239 return -EBUSY;
240 }
241
242 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
243
244 for (i = 0; i < VIDEO_MAX_FRAME; i++)
245 if (q->bufs[i] && q->bufs[i]->map) {
246 dprintk(1, "Cannot free mmapped buffers\n");
247 return -EBUSY;
248 }
249
250 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
251 if (NULL == q->bufs[i])
252 continue;
253 q->ops->buf_release(q, q->bufs[i]);
254 kfree(q->bufs[i]);
255 q->bufs[i] = NULL;
256 }
257
258 return 0;
259 }
260
261 /* Locking: Caller holds q->vb_lock */
videobuf_queue_cancel(struct videobuf_queue * q)262 void videobuf_queue_cancel(struct videobuf_queue *q)
263 {
264 unsigned long flags = 0;
265 int i;
266
267 q->streaming = 0;
268 q->reading = 0;
269 wake_up_interruptible_sync(&q->wait);
270
271 /* remove queued buffers from list */
272 spin_lock_irqsave(q->irqlock, flags);
273 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
274 if (NULL == q->bufs[i])
275 continue;
276 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
277 list_del(&q->bufs[i]->queue);
278 q->bufs[i]->state = VIDEOBUF_ERROR;
279 wake_up_all(&q->bufs[i]->done);
280 }
281 }
282 spin_unlock_irqrestore(q->irqlock, flags);
283
284 /* free all buffers + clear queue */
285 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
286 if (NULL == q->bufs[i])
287 continue;
288 q->ops->buf_release(q, q->bufs[i]);
289 }
290 INIT_LIST_HEAD(&q->stream);
291 }
292 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
293
294 /* --------------------------------------------------------------------- */
295
296 /* Locking: Caller holds q->vb_lock */
videobuf_next_field(struct videobuf_queue * q)297 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
298 {
299 enum v4l2_field field = q->field;
300
301 BUG_ON(V4L2_FIELD_ANY == field);
302
303 if (V4L2_FIELD_ALTERNATE == field) {
304 if (V4L2_FIELD_TOP == q->last) {
305 field = V4L2_FIELD_BOTTOM;
306 q->last = V4L2_FIELD_BOTTOM;
307 } else {
308 field = V4L2_FIELD_TOP;
309 q->last = V4L2_FIELD_TOP;
310 }
311 }
312 return field;
313 }
314 EXPORT_SYMBOL_GPL(videobuf_next_field);
315
316 /* Locking: Caller holds q->vb_lock */
videobuf_status(struct videobuf_queue * q,struct v4l2_buffer * b,struct videobuf_buffer * vb,enum v4l2_buf_type type)317 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
318 struct videobuf_buffer *vb, enum v4l2_buf_type type)
319 {
320 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
321 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
322
323 b->index = vb->i;
324 b->type = type;
325
326 b->memory = vb->memory;
327 switch (b->memory) {
328 case V4L2_MEMORY_MMAP:
329 b->m.offset = vb->boff;
330 b->length = vb->bsize;
331 break;
332 case V4L2_MEMORY_USERPTR:
333 b->m.userptr = vb->baddr;
334 b->length = vb->bsize;
335 break;
336 case V4L2_MEMORY_OVERLAY:
337 b->m.offset = vb->boff;
338 break;
339 case V4L2_MEMORY_DMABUF:
340 /* DMABUF is not handled in videobuf framework */
341 break;
342 }
343
344 b->flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
345 if (vb->map)
346 b->flags |= V4L2_BUF_FLAG_MAPPED;
347
348 switch (vb->state) {
349 case VIDEOBUF_PREPARED:
350 case VIDEOBUF_QUEUED:
351 case VIDEOBUF_ACTIVE:
352 b->flags |= V4L2_BUF_FLAG_QUEUED;
353 break;
354 case VIDEOBUF_ERROR:
355 b->flags |= V4L2_BUF_FLAG_ERROR;
356 /* fall through */
357 case VIDEOBUF_DONE:
358 b->flags |= V4L2_BUF_FLAG_DONE;
359 break;
360 case VIDEOBUF_NEEDS_INIT:
361 case VIDEOBUF_IDLE:
362 /* nothing */
363 break;
364 }
365
366 b->field = vb->field;
367 b->timestamp = ns_to_timeval(vb->ts);
368 b->bytesused = vb->size;
369 b->sequence = vb->field_count >> 1;
370 }
371
videobuf_mmap_free(struct videobuf_queue * q)372 int videobuf_mmap_free(struct videobuf_queue *q)
373 {
374 int ret;
375 videobuf_queue_lock(q);
376 ret = __videobuf_free(q);
377 videobuf_queue_unlock(q);
378 return ret;
379 }
380 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
381
382 /* Locking: Caller holds q->vb_lock */
__videobuf_mmap_setup(struct videobuf_queue * q,unsigned int bcount,unsigned int bsize,enum v4l2_memory memory)383 int __videobuf_mmap_setup(struct videobuf_queue *q,
384 unsigned int bcount, unsigned int bsize,
385 enum v4l2_memory memory)
386 {
387 unsigned int i;
388 int err;
389
390 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
391
392 err = __videobuf_free(q);
393 if (0 != err)
394 return err;
395
396 /* Allocate and initialize buffers */
397 for (i = 0; i < bcount; i++) {
398 q->bufs[i] = videobuf_alloc_vb(q);
399
400 if (NULL == q->bufs[i])
401 break;
402
403 q->bufs[i]->i = i;
404 q->bufs[i]->memory = memory;
405 q->bufs[i]->bsize = bsize;
406 switch (memory) {
407 case V4L2_MEMORY_MMAP:
408 q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
409 break;
410 case V4L2_MEMORY_USERPTR:
411 case V4L2_MEMORY_OVERLAY:
412 case V4L2_MEMORY_DMABUF:
413 /* nothing */
414 break;
415 }
416 }
417
418 if (!i)
419 return -ENOMEM;
420
421 dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
422
423 return i;
424 }
425 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
426
videobuf_mmap_setup(struct videobuf_queue * q,unsigned int bcount,unsigned int bsize,enum v4l2_memory memory)427 int videobuf_mmap_setup(struct videobuf_queue *q,
428 unsigned int bcount, unsigned int bsize,
429 enum v4l2_memory memory)
430 {
431 int ret;
432 videobuf_queue_lock(q);
433 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
434 videobuf_queue_unlock(q);
435 return ret;
436 }
437 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
438
videobuf_reqbufs(struct videobuf_queue * q,struct v4l2_requestbuffers * req)439 int videobuf_reqbufs(struct videobuf_queue *q,
440 struct v4l2_requestbuffers *req)
441 {
442 unsigned int size, count;
443 int retval;
444
445 if (req->memory != V4L2_MEMORY_MMAP &&
446 req->memory != V4L2_MEMORY_USERPTR &&
447 req->memory != V4L2_MEMORY_OVERLAY) {
448 dprintk(1, "reqbufs: memory type invalid\n");
449 return -EINVAL;
450 }
451
452 videobuf_queue_lock(q);
453 if (req->type != q->type) {
454 dprintk(1, "reqbufs: queue type invalid\n");
455 retval = -EINVAL;
456 goto done;
457 }
458
459 if (q->streaming) {
460 dprintk(1, "reqbufs: streaming already exists\n");
461 retval = -EBUSY;
462 goto done;
463 }
464 if (!list_empty(&q->stream)) {
465 dprintk(1, "reqbufs: stream running\n");
466 retval = -EBUSY;
467 goto done;
468 }
469
470 if (req->count == 0) {
471 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
472 retval = __videobuf_free(q);
473 goto done;
474 }
475
476 count = req->count;
477 if (count > VIDEO_MAX_FRAME)
478 count = VIDEO_MAX_FRAME;
479 size = 0;
480 q->ops->buf_setup(q, &count, &size);
481 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
482 count, size,
483 (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
484
485 retval = __videobuf_mmap_setup(q, count, size, req->memory);
486 if (retval < 0) {
487 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
488 goto done;
489 }
490
491 req->count = retval;
492 retval = 0;
493
494 done:
495 videobuf_queue_unlock(q);
496 return retval;
497 }
498 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
499
videobuf_querybuf(struct videobuf_queue * q,struct v4l2_buffer * b)500 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
501 {
502 int ret = -EINVAL;
503
504 videobuf_queue_lock(q);
505 if (unlikely(b->type != q->type)) {
506 dprintk(1, "querybuf: Wrong type.\n");
507 goto done;
508 }
509 if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
510 dprintk(1, "querybuf: index out of range.\n");
511 goto done;
512 }
513 if (unlikely(NULL == q->bufs[b->index])) {
514 dprintk(1, "querybuf: buffer is null.\n");
515 goto done;
516 }
517
518 videobuf_status(q, b, q->bufs[b->index], q->type);
519
520 ret = 0;
521 done:
522 videobuf_queue_unlock(q);
523 return ret;
524 }
525 EXPORT_SYMBOL_GPL(videobuf_querybuf);
526
videobuf_qbuf(struct videobuf_queue * q,struct v4l2_buffer * b)527 int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
528 {
529 struct videobuf_buffer *buf;
530 enum v4l2_field field;
531 unsigned long flags = 0;
532 int retval;
533
534 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
535
536 if (b->memory == V4L2_MEMORY_MMAP)
537 down_read(¤t->mm->mmap_sem);
538
539 videobuf_queue_lock(q);
540 retval = -EBUSY;
541 if (q->reading) {
542 dprintk(1, "qbuf: Reading running...\n");
543 goto done;
544 }
545 retval = -EINVAL;
546 if (b->type != q->type) {
547 dprintk(1, "qbuf: Wrong type.\n");
548 goto done;
549 }
550 if (b->index >= VIDEO_MAX_FRAME) {
551 dprintk(1, "qbuf: index out of range.\n");
552 goto done;
553 }
554 buf = q->bufs[b->index];
555 if (NULL == buf) {
556 dprintk(1, "qbuf: buffer is null.\n");
557 goto done;
558 }
559 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
560 if (buf->memory != b->memory) {
561 dprintk(1, "qbuf: memory type is wrong.\n");
562 goto done;
563 }
564 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
565 dprintk(1, "qbuf: buffer is already queued or active.\n");
566 goto done;
567 }
568
569 switch (b->memory) {
570 case V4L2_MEMORY_MMAP:
571 if (0 == buf->baddr) {
572 dprintk(1, "qbuf: mmap requested but buffer addr is zero!\n");
573 goto done;
574 }
575 if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
576 || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
577 || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT
578 || q->type == V4L2_BUF_TYPE_SDR_OUTPUT) {
579 buf->size = b->bytesused;
580 buf->field = b->field;
581 buf->ts = v4l2_timeval_to_ns(&b->timestamp);
582 }
583 break;
584 case V4L2_MEMORY_USERPTR:
585 if (b->length < buf->bsize) {
586 dprintk(1, "qbuf: buffer length is not enough\n");
587 goto done;
588 }
589 if (VIDEOBUF_NEEDS_INIT != buf->state &&
590 buf->baddr != b->m.userptr)
591 q->ops->buf_release(q, buf);
592 buf->baddr = b->m.userptr;
593 break;
594 case V4L2_MEMORY_OVERLAY:
595 buf->boff = b->m.offset;
596 break;
597 default:
598 dprintk(1, "qbuf: wrong memory type\n");
599 goto done;
600 }
601
602 dprintk(1, "qbuf: requesting next field\n");
603 field = videobuf_next_field(q);
604 retval = q->ops->buf_prepare(q, buf, field);
605 if (0 != retval) {
606 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
607 goto done;
608 }
609
610 list_add_tail(&buf->stream, &q->stream);
611 if (q->streaming) {
612 spin_lock_irqsave(q->irqlock, flags);
613 q->ops->buf_queue(q, buf);
614 spin_unlock_irqrestore(q->irqlock, flags);
615 }
616 dprintk(1, "qbuf: succeeded\n");
617 retval = 0;
618 wake_up_interruptible_sync(&q->wait);
619
620 done:
621 videobuf_queue_unlock(q);
622
623 if (b->memory == V4L2_MEMORY_MMAP)
624 up_read(¤t->mm->mmap_sem);
625
626 return retval;
627 }
628 EXPORT_SYMBOL_GPL(videobuf_qbuf);
629
630 /* Locking: Caller holds q->vb_lock */
stream_next_buffer_check_queue(struct videobuf_queue * q,int noblock)631 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
632 {
633 int retval;
634
635 checks:
636 if (!q->streaming) {
637 dprintk(1, "next_buffer: Not streaming\n");
638 retval = -EINVAL;
639 goto done;
640 }
641
642 if (list_empty(&q->stream)) {
643 if (noblock) {
644 retval = -EAGAIN;
645 dprintk(2, "next_buffer: no buffers to dequeue\n");
646 goto done;
647 } else {
648 dprintk(2, "next_buffer: waiting on buffer\n");
649
650 /* Drop lock to avoid deadlock with qbuf */
651 videobuf_queue_unlock(q);
652
653 /* Checking list_empty and streaming is safe without
654 * locks because we goto checks to validate while
655 * holding locks before proceeding */
656 retval = wait_event_interruptible(q->wait,
657 !list_empty(&q->stream) || !q->streaming);
658 videobuf_queue_lock(q);
659
660 if (retval)
661 goto done;
662
663 goto checks;
664 }
665 }
666
667 retval = 0;
668
669 done:
670 return retval;
671 }
672
673 /* Locking: Caller holds q->vb_lock */
stream_next_buffer(struct videobuf_queue * q,struct videobuf_buffer ** vb,int nonblocking)674 static int stream_next_buffer(struct videobuf_queue *q,
675 struct videobuf_buffer **vb, int nonblocking)
676 {
677 int retval;
678 struct videobuf_buffer *buf = NULL;
679
680 retval = stream_next_buffer_check_queue(q, nonblocking);
681 if (retval)
682 goto done;
683
684 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
685 retval = videobuf_waiton(q, buf, nonblocking, 1);
686 if (retval < 0)
687 goto done;
688
689 *vb = buf;
690 done:
691 return retval;
692 }
693
videobuf_dqbuf(struct videobuf_queue * q,struct v4l2_buffer * b,int nonblocking)694 int videobuf_dqbuf(struct videobuf_queue *q,
695 struct v4l2_buffer *b, int nonblocking)
696 {
697 struct videobuf_buffer *buf = NULL;
698 int retval;
699
700 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
701
702 memset(b, 0, sizeof(*b));
703 videobuf_queue_lock(q);
704
705 retval = stream_next_buffer(q, &buf, nonblocking);
706 if (retval < 0) {
707 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
708 goto done;
709 }
710
711 switch (buf->state) {
712 case VIDEOBUF_ERROR:
713 dprintk(1, "dqbuf: state is error\n");
714 break;
715 case VIDEOBUF_DONE:
716 dprintk(1, "dqbuf: state is done\n");
717 break;
718 default:
719 dprintk(1, "dqbuf: state invalid\n");
720 retval = -EINVAL;
721 goto done;
722 }
723 CALL(q, sync, q, buf);
724 videobuf_status(q, b, buf, q->type);
725 list_del(&buf->stream);
726 buf->state = VIDEOBUF_IDLE;
727 b->flags &= ~V4L2_BUF_FLAG_DONE;
728 done:
729 videobuf_queue_unlock(q);
730 return retval;
731 }
732 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
733
videobuf_streamon(struct videobuf_queue * q)734 int videobuf_streamon(struct videobuf_queue *q)
735 {
736 struct videobuf_buffer *buf;
737 unsigned long flags = 0;
738 int retval;
739
740 videobuf_queue_lock(q);
741 retval = -EBUSY;
742 if (q->reading)
743 goto done;
744 retval = 0;
745 if (q->streaming)
746 goto done;
747 q->streaming = 1;
748 spin_lock_irqsave(q->irqlock, flags);
749 list_for_each_entry(buf, &q->stream, stream)
750 if (buf->state == VIDEOBUF_PREPARED)
751 q->ops->buf_queue(q, buf);
752 spin_unlock_irqrestore(q->irqlock, flags);
753
754 wake_up_interruptible_sync(&q->wait);
755 done:
756 videobuf_queue_unlock(q);
757 return retval;
758 }
759 EXPORT_SYMBOL_GPL(videobuf_streamon);
760
761 /* Locking: Caller holds q->vb_lock */
__videobuf_streamoff(struct videobuf_queue * q)762 static int __videobuf_streamoff(struct videobuf_queue *q)
763 {
764 if (!q->streaming)
765 return -EINVAL;
766
767 videobuf_queue_cancel(q);
768
769 return 0;
770 }
771
videobuf_streamoff(struct videobuf_queue * q)772 int videobuf_streamoff(struct videobuf_queue *q)
773 {
774 int retval;
775
776 videobuf_queue_lock(q);
777 retval = __videobuf_streamoff(q);
778 videobuf_queue_unlock(q);
779
780 return retval;
781 }
782 EXPORT_SYMBOL_GPL(videobuf_streamoff);
783
784 /* Locking: Caller holds q->vb_lock */
videobuf_read_zerocopy(struct videobuf_queue * q,char __user * data,size_t count,loff_t * ppos)785 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
786 char __user *data,
787 size_t count, loff_t *ppos)
788 {
789 enum v4l2_field field;
790 unsigned long flags = 0;
791 int retval;
792
793 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
794
795 /* setup stuff */
796 q->read_buf = videobuf_alloc_vb(q);
797 if (NULL == q->read_buf)
798 return -ENOMEM;
799
800 q->read_buf->memory = V4L2_MEMORY_USERPTR;
801 q->read_buf->baddr = (unsigned long)data;
802 q->read_buf->bsize = count;
803
804 field = videobuf_next_field(q);
805 retval = q->ops->buf_prepare(q, q->read_buf, field);
806 if (0 != retval)
807 goto done;
808
809 /* start capture & wait */
810 spin_lock_irqsave(q->irqlock, flags);
811 q->ops->buf_queue(q, q->read_buf);
812 spin_unlock_irqrestore(q->irqlock, flags);
813 retval = videobuf_waiton(q, q->read_buf, 0, 0);
814 if (0 == retval) {
815 CALL(q, sync, q, q->read_buf);
816 if (VIDEOBUF_ERROR == q->read_buf->state)
817 retval = -EIO;
818 else
819 retval = q->read_buf->size;
820 }
821
822 done:
823 /* cleanup */
824 q->ops->buf_release(q, q->read_buf);
825 kfree(q->read_buf);
826 q->read_buf = NULL;
827 return retval;
828 }
829
__videobuf_copy_to_user(struct videobuf_queue * q,struct videobuf_buffer * buf,char __user * data,size_t count,int nonblocking)830 static int __videobuf_copy_to_user(struct videobuf_queue *q,
831 struct videobuf_buffer *buf,
832 char __user *data, size_t count,
833 int nonblocking)
834 {
835 void *vaddr = CALLPTR(q, vaddr, buf);
836
837 /* copy to userspace */
838 if (count > buf->size - q->read_off)
839 count = buf->size - q->read_off;
840
841 if (copy_to_user(data, vaddr + q->read_off, count))
842 return -EFAULT;
843
844 return count;
845 }
846
__videobuf_copy_stream(struct videobuf_queue * q,struct videobuf_buffer * buf,char __user * data,size_t count,size_t pos,int vbihack,int nonblocking)847 static int __videobuf_copy_stream(struct videobuf_queue *q,
848 struct videobuf_buffer *buf,
849 char __user *data, size_t count, size_t pos,
850 int vbihack, int nonblocking)
851 {
852 unsigned int *fc = CALLPTR(q, vaddr, buf);
853
854 if (vbihack) {
855 /* dirty, undocumented hack -- pass the frame counter
856 * within the last four bytes of each vbi data block.
857 * We need that one to maintain backward compatibility
858 * to all vbi decoding software out there ... */
859 fc += (buf->size >> 2) - 1;
860 *fc = buf->field_count >> 1;
861 dprintk(1, "vbihack: %d\n", *fc);
862 }
863
864 /* copy stuff using the common method */
865 count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
866
867 if ((count == -EFAULT) && (pos == 0))
868 return -EFAULT;
869
870 return count;
871 }
872
videobuf_read_one(struct videobuf_queue * q,char __user * data,size_t count,loff_t * ppos,int nonblocking)873 ssize_t videobuf_read_one(struct videobuf_queue *q,
874 char __user *data, size_t count, loff_t *ppos,
875 int nonblocking)
876 {
877 enum v4l2_field field;
878 unsigned long flags = 0;
879 unsigned size = 0, nbufs = 1;
880 int retval;
881
882 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
883
884 videobuf_queue_lock(q);
885
886 q->ops->buf_setup(q, &nbufs, &size);
887
888 if (NULL == q->read_buf &&
889 count >= size &&
890 !nonblocking) {
891 retval = videobuf_read_zerocopy(q, data, count, ppos);
892 if (retval >= 0 || retval == -EIO)
893 /* ok, all done */
894 goto done;
895 /* fallback to kernel bounce buffer on failures */
896 }
897
898 if (NULL == q->read_buf) {
899 /* need to capture a new frame */
900 retval = -ENOMEM;
901 q->read_buf = videobuf_alloc_vb(q);
902
903 dprintk(1, "video alloc=0x%p\n", q->read_buf);
904 if (NULL == q->read_buf)
905 goto done;
906 q->read_buf->memory = V4L2_MEMORY_USERPTR;
907 q->read_buf->bsize = count; /* preferred size */
908 field = videobuf_next_field(q);
909 retval = q->ops->buf_prepare(q, q->read_buf, field);
910
911 if (0 != retval) {
912 kfree(q->read_buf);
913 q->read_buf = NULL;
914 goto done;
915 }
916
917 spin_lock_irqsave(q->irqlock, flags);
918 q->ops->buf_queue(q, q->read_buf);
919 spin_unlock_irqrestore(q->irqlock, flags);
920
921 q->read_off = 0;
922 }
923
924 /* wait until capture is done */
925 retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
926 if (0 != retval)
927 goto done;
928
929 CALL(q, sync, q, q->read_buf);
930
931 if (VIDEOBUF_ERROR == q->read_buf->state) {
932 /* catch I/O errors */
933 q->ops->buf_release(q, q->read_buf);
934 kfree(q->read_buf);
935 q->read_buf = NULL;
936 retval = -EIO;
937 goto done;
938 }
939
940 /* Copy to userspace */
941 retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
942 if (retval < 0)
943 goto done;
944
945 q->read_off += retval;
946 if (q->read_off == q->read_buf->size) {
947 /* all data copied, cleanup */
948 q->ops->buf_release(q, q->read_buf);
949 kfree(q->read_buf);
950 q->read_buf = NULL;
951 }
952
953 done:
954 videobuf_queue_unlock(q);
955 return retval;
956 }
957 EXPORT_SYMBOL_GPL(videobuf_read_one);
958
959 /* Locking: Caller holds q->vb_lock */
__videobuf_read_start(struct videobuf_queue * q)960 static int __videobuf_read_start(struct videobuf_queue *q)
961 {
962 enum v4l2_field field;
963 unsigned long flags = 0;
964 unsigned int count = 0, size = 0;
965 int err, i;
966
967 q->ops->buf_setup(q, &count, &size);
968 if (count < 2)
969 count = 2;
970 if (count > VIDEO_MAX_FRAME)
971 count = VIDEO_MAX_FRAME;
972 size = PAGE_ALIGN(size);
973
974 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
975 if (err < 0)
976 return err;
977
978 count = err;
979
980 for (i = 0; i < count; i++) {
981 field = videobuf_next_field(q);
982 err = q->ops->buf_prepare(q, q->bufs[i], field);
983 if (err)
984 return err;
985 list_add_tail(&q->bufs[i]->stream, &q->stream);
986 }
987 spin_lock_irqsave(q->irqlock, flags);
988 for (i = 0; i < count; i++)
989 q->ops->buf_queue(q, q->bufs[i]);
990 spin_unlock_irqrestore(q->irqlock, flags);
991 q->reading = 1;
992 return 0;
993 }
994
__videobuf_read_stop(struct videobuf_queue * q)995 static void __videobuf_read_stop(struct videobuf_queue *q)
996 {
997 int i;
998
999 videobuf_queue_cancel(q);
1000 __videobuf_free(q);
1001 INIT_LIST_HEAD(&q->stream);
1002 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1003 if (NULL == q->bufs[i])
1004 continue;
1005 kfree(q->bufs[i]);
1006 q->bufs[i] = NULL;
1007 }
1008 q->read_buf = NULL;
1009 }
1010
videobuf_read_start(struct videobuf_queue * q)1011 int videobuf_read_start(struct videobuf_queue *q)
1012 {
1013 int rc;
1014
1015 videobuf_queue_lock(q);
1016 rc = __videobuf_read_start(q);
1017 videobuf_queue_unlock(q);
1018
1019 return rc;
1020 }
1021 EXPORT_SYMBOL_GPL(videobuf_read_start);
1022
videobuf_read_stop(struct videobuf_queue * q)1023 void videobuf_read_stop(struct videobuf_queue *q)
1024 {
1025 videobuf_queue_lock(q);
1026 __videobuf_read_stop(q);
1027 videobuf_queue_unlock(q);
1028 }
1029 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1030
videobuf_stop(struct videobuf_queue * q)1031 void videobuf_stop(struct videobuf_queue *q)
1032 {
1033 videobuf_queue_lock(q);
1034
1035 if (q->streaming)
1036 __videobuf_streamoff(q);
1037
1038 if (q->reading)
1039 __videobuf_read_stop(q);
1040
1041 videobuf_queue_unlock(q);
1042 }
1043 EXPORT_SYMBOL_GPL(videobuf_stop);
1044
videobuf_read_stream(struct videobuf_queue * q,char __user * data,size_t count,loff_t * ppos,int vbihack,int nonblocking)1045 ssize_t videobuf_read_stream(struct videobuf_queue *q,
1046 char __user *data, size_t count, loff_t *ppos,
1047 int vbihack, int nonblocking)
1048 {
1049 int rc, retval;
1050 unsigned long flags = 0;
1051
1052 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1053
1054 dprintk(2, "%s\n", __func__);
1055 videobuf_queue_lock(q);
1056 retval = -EBUSY;
1057 if (q->streaming)
1058 goto done;
1059 if (!q->reading) {
1060 retval = __videobuf_read_start(q);
1061 if (retval < 0)
1062 goto done;
1063 }
1064
1065 retval = 0;
1066 while (count > 0) {
1067 /* get / wait for data */
1068 if (NULL == q->read_buf) {
1069 q->read_buf = list_entry(q->stream.next,
1070 struct videobuf_buffer,
1071 stream);
1072 list_del(&q->read_buf->stream);
1073 q->read_off = 0;
1074 }
1075 rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
1076 if (rc < 0) {
1077 if (0 == retval)
1078 retval = rc;
1079 break;
1080 }
1081
1082 if (q->read_buf->state == VIDEOBUF_DONE) {
1083 rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
1084 retval, vbihack, nonblocking);
1085 if (rc < 0) {
1086 retval = rc;
1087 break;
1088 }
1089 retval += rc;
1090 count -= rc;
1091 q->read_off += rc;
1092 } else {
1093 /* some error */
1094 q->read_off = q->read_buf->size;
1095 if (0 == retval)
1096 retval = -EIO;
1097 }
1098
1099 /* requeue buffer when done with copying */
1100 if (q->read_off == q->read_buf->size) {
1101 list_add_tail(&q->read_buf->stream,
1102 &q->stream);
1103 spin_lock_irqsave(q->irqlock, flags);
1104 q->ops->buf_queue(q, q->read_buf);
1105 spin_unlock_irqrestore(q->irqlock, flags);
1106 q->read_buf = NULL;
1107 }
1108 if (retval < 0)
1109 break;
1110 }
1111
1112 done:
1113 videobuf_queue_unlock(q);
1114 return retval;
1115 }
1116 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1117
videobuf_poll_stream(struct file * file,struct videobuf_queue * q,poll_table * wait)1118 __poll_t videobuf_poll_stream(struct file *file,
1119 struct videobuf_queue *q,
1120 poll_table *wait)
1121 {
1122 __poll_t req_events = poll_requested_events(wait);
1123 struct videobuf_buffer *buf = NULL;
1124 __poll_t rc = 0;
1125
1126 videobuf_queue_lock(q);
1127 if (q->streaming) {
1128 if (!list_empty(&q->stream))
1129 buf = list_entry(q->stream.next,
1130 struct videobuf_buffer, stream);
1131 } else if (req_events & (EPOLLIN | EPOLLRDNORM)) {
1132 if (!q->reading)
1133 __videobuf_read_start(q);
1134 if (!q->reading) {
1135 rc = EPOLLERR;
1136 } else if (NULL == q->read_buf) {
1137 q->read_buf = list_entry(q->stream.next,
1138 struct videobuf_buffer,
1139 stream);
1140 list_del(&q->read_buf->stream);
1141 q->read_off = 0;
1142 }
1143 buf = q->read_buf;
1144 }
1145 if (buf)
1146 poll_wait(file, &buf->done, wait);
1147 else
1148 rc = EPOLLERR;
1149
1150 if (0 == rc) {
1151 if (buf->state == VIDEOBUF_DONE ||
1152 buf->state == VIDEOBUF_ERROR) {
1153 switch (q->type) {
1154 case V4L2_BUF_TYPE_VIDEO_OUTPUT:
1155 case V4L2_BUF_TYPE_VBI_OUTPUT:
1156 case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
1157 case V4L2_BUF_TYPE_SDR_OUTPUT:
1158 rc = EPOLLOUT | EPOLLWRNORM;
1159 break;
1160 default:
1161 rc = EPOLLIN | EPOLLRDNORM;
1162 break;
1163 }
1164 }
1165 }
1166 videobuf_queue_unlock(q);
1167 return rc;
1168 }
1169 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1170
videobuf_mmap_mapper(struct videobuf_queue * q,struct vm_area_struct * vma)1171 int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
1172 {
1173 int rc = -EINVAL;
1174 int i;
1175
1176 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1177
1178 if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
1179 dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
1180 return -EINVAL;
1181 }
1182
1183 videobuf_queue_lock(q);
1184 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
1185 struct videobuf_buffer *buf = q->bufs[i];
1186
1187 if (buf && buf->memory == V4L2_MEMORY_MMAP &&
1188 buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
1189 rc = CALL(q, mmap_mapper, q, buf, vma);
1190 break;
1191 }
1192 }
1193 videobuf_queue_unlock(q);
1194
1195 return rc;
1196 }
1197 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
1198