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V4L/DVB (7121): Renames videobuf lock to vb_lock
[deliverable/linux.git] / drivers / media / video / videobuf-core.c
1 /*
2 * generic helper functions for handling video4linux capture buffers
3 *
4 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
5 *
6 * Highly based on video-buf written originally by:
7 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
8 * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
9 * (c) 2006 Ted Walther and John Sokol
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2
14 */
15
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
21
22 #include <media/videobuf-core.h>
23
24 #define MAGIC_BUFFER 0x20070728
25 #define MAGIC_CHECK(is, should) do { \
26 if (unlikely((is) != (should))) { \
27 printk(KERN_ERR "magic mismatch: %x (expected %x)\n", is, should); \
28 BUG(); } } while (0)
29
30 static int debug;
31 module_param(debug, int, 0644);
32
33 MODULE_DESCRIPTION("helper module to manage video4linux buffers");
34 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
35 MODULE_LICENSE("GPL");
36
37 #define dprintk(level, fmt, arg...) do { \
38 if (debug >= level) \
39 printk(KERN_DEBUG "vbuf: " fmt , ## arg); } while (0)
40
41 /* --------------------------------------------------------------------- */
42
43 #define CALL(q, f, arg...) \
44 ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
45
46 void *videobuf_alloc(struct videobuf_queue *q)
47 {
48 struct videobuf_buffer *vb;
49
50 BUG_ON(q->msize < sizeof(*vb));
51
52 if (!q->int_ops || !q->int_ops->alloc) {
53 printk(KERN_ERR "No specific ops defined!\n");
54 BUG();
55 }
56
57 vb = q->int_ops->alloc(q->msize);
58
59 if (NULL != vb) {
60 init_waitqueue_head(&vb->done);
61 vb->magic = MAGIC_BUFFER;
62 }
63
64 return vb;
65 }
66
67 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
68 {
69 int retval = 0;
70 DECLARE_WAITQUEUE(wait, current);
71
72 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
73 add_wait_queue(&vb->done, &wait);
74 while (vb->state == VIDEOBUF_ACTIVE || vb->state == VIDEOBUF_QUEUED) {
75 if (non_blocking) {
76 retval = -EAGAIN;
77 break;
78 }
79 set_current_state(intr ? TASK_INTERRUPTIBLE
80 : TASK_UNINTERRUPTIBLE);
81 if (vb->state == VIDEOBUF_ACTIVE ||
82 vb->state == VIDEOBUF_QUEUED)
83 schedule();
84 set_current_state(TASK_RUNNING);
85 if (intr && signal_pending(current)) {
86 dprintk(1, "buffer waiton: -EINTR\n");
87 retval = -EINTR;
88 break;
89 }
90 }
91 remove_wait_queue(&vb->done, &wait);
92 return retval;
93 }
94
95 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
96 struct v4l2_framebuffer *fbuf)
97 {
98 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
99 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
100
101 /* This is required to avoid OOPS on some cases,
102 since mmap_mapper() method should be called before _iolock.
103 On some cases, the mmap_mapper() is called only after scheduling.
104 */
105 if (vb->memory == V4L2_MEMORY_MMAP) {
106 wait_event_timeout(vb->done, q->is_mmapped,
107 msecs_to_jiffies(100));
108 if (!q->is_mmapped) {
109 printk(KERN_ERR
110 "Error: mmap_mapper() never called!\n");
111 return -EINVAL;
112 }
113 }
114
115 return CALL(q, iolock, q, vb, fbuf);
116 }
117
118 /* --------------------------------------------------------------------- */
119
120
121 void videobuf_queue_core_init(struct videobuf_queue *q,
122 struct videobuf_queue_ops *ops,
123 void *dev,
124 spinlock_t *irqlock,
125 enum v4l2_buf_type type,
126 enum v4l2_field field,
127 unsigned int msize,
128 void *priv,
129 struct videobuf_qtype_ops *int_ops)
130 {
131 memset(q, 0, sizeof(*q));
132 q->irqlock = irqlock;
133 q->dev = dev;
134 q->type = type;
135 q->field = field;
136 q->msize = msize;
137 q->ops = ops;
138 q->priv_data = priv;
139 q->int_ops = int_ops;
140
141 /* All buffer operations are mandatory */
142 BUG_ON(!q->ops->buf_setup);
143 BUG_ON(!q->ops->buf_prepare);
144 BUG_ON(!q->ops->buf_queue);
145 BUG_ON(!q->ops->buf_release);
146
147 /* Having implementations for abstract methods are mandatory */
148 BUG_ON(!q->int_ops);
149
150 mutex_init(&q->vb_lock);
151 INIT_LIST_HEAD(&q->stream);
152 }
153
154 /* Locking: Only usage in bttv unsafe find way to remove */
155 int videobuf_queue_is_busy(struct videobuf_queue *q)
156 {
157 int i;
158
159 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
160
161 if (q->streaming) {
162 dprintk(1, "busy: streaming active\n");
163 return 1;
164 }
165 if (q->reading) {
166 dprintk(1, "busy: pending read #1\n");
167 return 1;
168 }
169 if (q->read_buf) {
170 dprintk(1, "busy: pending read #2\n");
171 return 1;
172 }
173 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
174 if (NULL == q->bufs[i])
175 continue;
176 if (q->bufs[i]->map) {
177 dprintk(1, "busy: buffer #%d mapped\n", i);
178 return 1;
179 }
180 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
181 dprintk(1, "busy: buffer #%d queued\n", i);
182 return 1;
183 }
184 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
185 dprintk(1, "busy: buffer #%d avtive\n", i);
186 return 1;
187 }
188 }
189 return 0;
190 }
191
192 /* Locking: Caller holds q->vb_lock */
193 void videobuf_queue_cancel(struct videobuf_queue *q)
194 {
195 unsigned long flags = 0;
196 int i;
197
198 /* remove queued buffers from list */
199 if (q->irqlock)
200 spin_lock_irqsave(q->irqlock, flags);
201 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
202 if (NULL == q->bufs[i])
203 continue;
204 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
205 list_del(&q->bufs[i]->queue);
206 q->bufs[i]->state = VIDEOBUF_ERROR;
207 }
208 }
209 if (q->irqlock)
210 spin_unlock_irqrestore(q->irqlock, flags);
211
212 /* free all buffers + clear queue */
213 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
214 if (NULL == q->bufs[i])
215 continue;
216 q->ops->buf_release(q, q->bufs[i]);
217 }
218 INIT_LIST_HEAD(&q->stream);
219 }
220
221 /* --------------------------------------------------------------------- */
222
223 /* Locking: Caller holds q->vb_lock */
224 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
225 {
226 enum v4l2_field field = q->field;
227
228 BUG_ON(V4L2_FIELD_ANY == field);
229
230 if (V4L2_FIELD_ALTERNATE == field) {
231 if (V4L2_FIELD_TOP == q->last) {
232 field = V4L2_FIELD_BOTTOM;
233 q->last = V4L2_FIELD_BOTTOM;
234 } else {
235 field = V4L2_FIELD_TOP;
236 q->last = V4L2_FIELD_TOP;
237 }
238 }
239 return field;
240 }
241
242 /* Locking: Caller holds q->vb_lock */
243 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
244 struct videobuf_buffer *vb, enum v4l2_buf_type type)
245 {
246 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
247 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
248
249 b->index = vb->i;
250 b->type = type;
251
252 b->memory = vb->memory;
253 switch (b->memory) {
254 case V4L2_MEMORY_MMAP:
255 b->m.offset = vb->boff;
256 b->length = vb->bsize;
257 break;
258 case V4L2_MEMORY_USERPTR:
259 b->m.userptr = vb->baddr;
260 b->length = vb->bsize;
261 break;
262 case V4L2_MEMORY_OVERLAY:
263 b->m.offset = vb->boff;
264 break;
265 }
266
267 b->flags = 0;
268 if (vb->map)
269 b->flags |= V4L2_BUF_FLAG_MAPPED;
270
271 switch (vb->state) {
272 case VIDEOBUF_PREPARED:
273 case VIDEOBUF_QUEUED:
274 case VIDEOBUF_ACTIVE:
275 b->flags |= V4L2_BUF_FLAG_QUEUED;
276 break;
277 case VIDEOBUF_DONE:
278 case VIDEOBUF_ERROR:
279 b->flags |= V4L2_BUF_FLAG_DONE;
280 break;
281 case VIDEOBUF_NEEDS_INIT:
282 case VIDEOBUF_IDLE:
283 /* nothing */
284 break;
285 }
286
287 if (vb->input != UNSET) {
288 b->flags |= V4L2_BUF_FLAG_INPUT;
289 b->input = vb->input;
290 }
291
292 b->field = vb->field;
293 b->timestamp = vb->ts;
294 b->bytesused = vb->size;
295 b->sequence = vb->field_count >> 1;
296 }
297
298 /* Locking: Caller holds q->vb_lock */
299 static int __videobuf_mmap_free(struct videobuf_queue *q)
300 {
301 int i;
302 int rc;
303
304 if (!q)
305 return 0;
306
307 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
308
309
310 rc = CALL(q, mmap_free, q);
311
312 q->is_mmapped = 0;
313
314 if (rc < 0)
315 return rc;
316
317 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
318 if (NULL == q->bufs[i])
319 continue;
320 q->ops->buf_release(q, q->bufs[i]);
321 kfree(q->bufs[i]);
322 q->bufs[i] = NULL;
323 }
324
325 return rc;
326 }
327
328 int videobuf_mmap_free(struct videobuf_queue *q)
329 {
330 int ret;
331 mutex_lock(&q->vb_lock);
332 ret = __videobuf_mmap_free(q);
333 mutex_unlock(&q->vb_lock);
334 return ret;
335 }
336
337 /* Locking: Caller holds q->vb_lock */
338 static int __videobuf_mmap_setup(struct videobuf_queue *q,
339 unsigned int bcount, unsigned int bsize,
340 enum v4l2_memory memory)
341 {
342 unsigned int i;
343 int err;
344
345 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
346
347 err = __videobuf_mmap_free(q);
348 if (0 != err)
349 return err;
350
351 /* Allocate and initialize buffers */
352 for (i = 0; i < bcount; i++) {
353 q->bufs[i] = videobuf_alloc(q);
354
355 if (q->bufs[i] == NULL)
356 break;
357
358 q->bufs[i]->i = i;
359 q->bufs[i]->input = UNSET;
360 q->bufs[i]->memory = memory;
361 q->bufs[i]->bsize = bsize;
362 switch (memory) {
363 case V4L2_MEMORY_MMAP:
364 q->bufs[i]->boff = bsize * i;
365 break;
366 case V4L2_MEMORY_USERPTR:
367 case V4L2_MEMORY_OVERLAY:
368 /* nothing */
369 break;
370 }
371 }
372
373 if (!i)
374 return -ENOMEM;
375
376 dprintk(1, "mmap setup: %d buffers, %d bytes each\n",
377 i, bsize);
378
379 return i;
380 }
381
382 int videobuf_mmap_setup(struct videobuf_queue *q,
383 unsigned int bcount, unsigned int bsize,
384 enum v4l2_memory memory)
385 {
386 int ret;
387 mutex_lock(&q->vb_lock);
388 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
389 mutex_unlock(&q->vb_lock);
390 return ret;
391 }
392
393 int videobuf_reqbufs(struct videobuf_queue *q,
394 struct v4l2_requestbuffers *req)
395 {
396 unsigned int size, count;
397 int retval;
398
399 if (req->count < 1) {
400 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
401 return -EINVAL;
402 }
403
404 if (req->memory != V4L2_MEMORY_MMAP &&
405 req->memory != V4L2_MEMORY_USERPTR &&
406 req->memory != V4L2_MEMORY_OVERLAY) {
407 dprintk(1, "reqbufs: memory type invalid\n");
408 return -EINVAL;
409 }
410
411 mutex_lock(&q->vb_lock);
412 if (req->type != q->type) {
413 dprintk(1, "reqbufs: queue type invalid\n");
414 retval = -EINVAL;
415 goto done;
416 }
417
418 if (q->streaming) {
419 dprintk(1, "reqbufs: streaming already exists\n");
420 retval = -EBUSY;
421 goto done;
422 }
423 if (!list_empty(&q->stream)) {
424 dprintk(1, "reqbufs: stream running\n");
425 retval = -EBUSY;
426 goto done;
427 }
428
429 count = req->count;
430 if (count > VIDEO_MAX_FRAME)
431 count = VIDEO_MAX_FRAME;
432 size = 0;
433 q->ops->buf_setup(q, &count, &size);
434 size = PAGE_ALIGN(size);
435 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
436 count, size, (count*size)>>PAGE_SHIFT);
437
438 retval = __videobuf_mmap_setup(q, count, size, req->memory);
439 if (retval < 0) {
440 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
441 goto done;
442 }
443
444 req->count = retval;
445
446 done:
447 mutex_unlock(&q->vb_lock);
448 return retval;
449 }
450
451 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
452 {
453 int ret = -EINVAL;
454
455 mutex_lock(&q->vb_lock);
456 if (unlikely(b->type != q->type)) {
457 dprintk(1, "querybuf: Wrong type.\n");
458 goto done;
459 }
460 if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
461 dprintk(1, "querybuf: index out of range.\n");
462 goto done;
463 }
464 if (unlikely(NULL == q->bufs[b->index])) {
465 dprintk(1, "querybuf: buffer is null.\n");
466 goto done;
467 }
468
469 videobuf_status(q, b, q->bufs[b->index], q->type);
470
471 ret = 0;
472 done:
473 mutex_unlock(&q->vb_lock);
474 return ret;
475 }
476
477 int videobuf_qbuf(struct videobuf_queue *q,
478 struct v4l2_buffer *b)
479 {
480 struct videobuf_buffer *buf;
481 enum v4l2_field field;
482 unsigned long flags = 0;
483 int retval;
484
485 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
486
487 if (b->memory == V4L2_MEMORY_MMAP)
488 down_read(&current->mm->mmap_sem);
489
490 mutex_lock(&q->vb_lock);
491 retval = -EBUSY;
492 if (q->reading) {
493 dprintk(1, "qbuf: Reading running...\n");
494 goto done;
495 }
496 retval = -EINVAL;
497 if (b->type != q->type) {
498 dprintk(1, "qbuf: Wrong type.\n");
499 goto done;
500 }
501 if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
502 dprintk(1, "qbuf: index out of range.\n");
503 goto done;
504 }
505 buf = q->bufs[b->index];
506 if (NULL == buf) {
507 dprintk(1, "qbuf: buffer is null.\n");
508 goto done;
509 }
510 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
511 if (buf->memory != b->memory) {
512 dprintk(1, "qbuf: memory type is wrong.\n");
513 goto done;
514 }
515 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
516 dprintk(1, "qbuf: buffer is already queued or active.\n");
517 goto done;
518 }
519
520 if (b->flags & V4L2_BUF_FLAG_INPUT) {
521 if (b->input >= q->inputs) {
522 dprintk(1, "qbuf: wrong input.\n");
523 goto done;
524 }
525 buf->input = b->input;
526 } else {
527 buf->input = UNSET;
528 }
529
530 switch (b->memory) {
531 case V4L2_MEMORY_MMAP:
532 if (0 == buf->baddr) {
533 dprintk(1, "qbuf: mmap requested "
534 "but buffer addr is zero!\n");
535 goto done;
536 }
537 break;
538 case V4L2_MEMORY_USERPTR:
539 if (b->length < buf->bsize) {
540 dprintk(1, "qbuf: buffer length is not enough\n");
541 goto done;
542 }
543 if (VIDEOBUF_NEEDS_INIT != buf->state &&
544 buf->baddr != b->m.userptr)
545 q->ops->buf_release(q, buf);
546 buf->baddr = b->m.userptr;
547 break;
548 case V4L2_MEMORY_OVERLAY:
549 buf->boff = b->m.offset;
550 break;
551 default:
552 dprintk(1, "qbuf: wrong memory type\n");
553 goto done;
554 }
555
556 dprintk(1, "qbuf: requesting next field\n");
557 field = videobuf_next_field(q);
558 retval = q->ops->buf_prepare(q, buf, field);
559 if (0 != retval) {
560 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
561 goto done;
562 }
563
564 list_add_tail(&buf->stream, &q->stream);
565 if (q->streaming) {
566 if (q->irqlock)
567 spin_lock_irqsave(q->irqlock, flags);
568 q->ops->buf_queue(q, buf);
569 if (q->irqlock)
570 spin_unlock_irqrestore(q->irqlock, flags);
571 }
572 dprintk(1, "qbuf: succeded\n");
573 retval = 0;
574
575 done:
576 mutex_unlock(&q->vb_lock);
577
578 if (b->memory == V4L2_MEMORY_MMAP)
579 up_read(&current->mm->mmap_sem);
580
581 return retval;
582 }
583
584 int videobuf_dqbuf(struct videobuf_queue *q,
585 struct v4l2_buffer *b, int nonblocking)
586 {
587 struct videobuf_buffer *buf;
588 int retval;
589
590 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
591
592 mutex_lock(&q->vb_lock);
593 retval = -EBUSY;
594 if (q->reading) {
595 dprintk(1, "dqbuf: Reading running...\n");
596 goto done;
597 }
598 retval = -EINVAL;
599 if (b->type != q->type) {
600 dprintk(1, "dqbuf: Wrong type.\n");
601 goto done;
602 }
603 if (list_empty(&q->stream)) {
604 dprintk(1, "dqbuf: stream running\n");
605 goto done;
606 }
607 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
608 retval = videobuf_waiton(buf, nonblocking, 1);
609 if (retval < 0) {
610 dprintk(1, "dqbuf: waiton returned %d\n", retval);
611 goto done;
612 }
613 switch (buf->state) {
614 case VIDEOBUF_ERROR:
615 dprintk(1, "dqbuf: state is error\n");
616 retval = -EIO;
617 CALL(q, sync, q, buf);
618 buf->state = VIDEOBUF_IDLE;
619 break;
620 case VIDEOBUF_DONE:
621 dprintk(1, "dqbuf: state is done\n");
622 CALL(q, sync, q, buf);
623 buf->state = VIDEOBUF_IDLE;
624 break;
625 default:
626 dprintk(1, "dqbuf: state invalid\n");
627 retval = -EINVAL;
628 goto done;
629 }
630 list_del(&buf->stream);
631 memset(b, 0, sizeof(*b));
632 videobuf_status(q, b, buf, q->type);
633
634 done:
635 mutex_unlock(&q->vb_lock);
636 return retval;
637 }
638
639 int videobuf_streamon(struct videobuf_queue *q)
640 {
641 struct videobuf_buffer *buf;
642 unsigned long flags = 0;
643 int retval;
644
645 mutex_lock(&q->vb_lock);
646 retval = -EBUSY;
647 if (q->reading)
648 goto done;
649 retval = 0;
650 if (q->streaming)
651 goto done;
652 q->streaming = 1;
653 if (q->irqlock)
654 spin_lock_irqsave(q->irqlock, flags);
655 list_for_each_entry(buf, &q->stream, stream)
656 if (buf->state == VIDEOBUF_PREPARED)
657 q->ops->buf_queue(q, buf);
658 if (q->irqlock)
659 spin_unlock_irqrestore(q->irqlock, flags);
660
661 done:
662 mutex_unlock(&q->vb_lock);
663 return retval;
664 }
665
666 /* Locking: Caller holds q->vb_lock */
667 static int __videobuf_streamoff(struct videobuf_queue *q)
668 {
669 if (!q->streaming)
670 return -EINVAL;
671
672 videobuf_queue_cancel(q);
673 q->streaming = 0;
674
675 return 0;
676 }
677
678 int videobuf_streamoff(struct videobuf_queue *q)
679 {
680 int retval;
681
682 mutex_lock(&q->vb_lock);
683 retval = __videobuf_streamoff(q);
684 mutex_unlock(&q->vb_lock);
685
686 return retval;
687 }
688
689 /* Locking: Caller holds q->vb_lock */
690 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
691 char __user *data,
692 size_t count, loff_t *ppos)
693 {
694 enum v4l2_field field;
695 unsigned long flags = 0;
696 int retval;
697
698 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
699
700 /* setup stuff */
701 q->read_buf = videobuf_alloc(q);
702 if (NULL == q->read_buf)
703 return -ENOMEM;
704
705 q->read_buf->memory = V4L2_MEMORY_USERPTR;
706 q->read_buf->baddr = (unsigned long)data;
707 q->read_buf->bsize = count;
708
709 field = videobuf_next_field(q);
710 retval = q->ops->buf_prepare(q, q->read_buf, field);
711 if (0 != retval)
712 goto done;
713
714 /* start capture & wait */
715 if (q->irqlock)
716 spin_lock_irqsave(q->irqlock, flags);
717 q->ops->buf_queue(q, q->read_buf);
718 if (q->irqlock)
719 spin_unlock_irqrestore(q->irqlock, flags);
720 retval = videobuf_waiton(q->read_buf, 0, 0);
721 if (0 == retval) {
722 CALL(q, sync, q, q->read_buf);
723 if (VIDEOBUF_ERROR == q->read_buf->state)
724 retval = -EIO;
725 else
726 retval = q->read_buf->size;
727 }
728
729 done:
730 /* cleanup */
731 q->ops->buf_release(q, q->read_buf);
732 kfree(q->read_buf);
733 q->read_buf = NULL;
734 return retval;
735 }
736
737 ssize_t videobuf_read_one(struct videobuf_queue *q,
738 char __user *data, size_t count, loff_t *ppos,
739 int nonblocking)
740 {
741 enum v4l2_field field;
742 unsigned long flags = 0;
743 unsigned size, nbufs;
744 int retval;
745
746 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
747
748 mutex_lock(&q->vb_lock);
749
750 nbufs = 1; size = 0;
751 q->ops->buf_setup(q, &nbufs, &size);
752
753 if (NULL == q->read_buf &&
754 count >= size &&
755 !nonblocking) {
756 retval = videobuf_read_zerocopy(q, data, count, ppos);
757 if (retval >= 0 || retval == -EIO)
758 /* ok, all done */
759 goto done;
760 /* fallback to kernel bounce buffer on failures */
761 }
762
763 if (NULL == q->read_buf) {
764 /* need to capture a new frame */
765 retval = -ENOMEM;
766 q->read_buf = videobuf_alloc(q);
767
768 dprintk(1, "video alloc=0x%p\n", q->read_buf);
769 if (NULL == q->read_buf)
770 goto done;
771 q->read_buf->memory = V4L2_MEMORY_USERPTR;
772 q->read_buf->bsize = count; /* preferred size */
773 field = videobuf_next_field(q);
774 retval = q->ops->buf_prepare(q, q->read_buf, field);
775
776 if (0 != retval) {
777 kfree(q->read_buf);
778 q->read_buf = NULL;
779 goto done;
780 }
781 if (q->irqlock)
782 spin_lock_irqsave(q->irqlock, flags);
783
784 q->ops->buf_queue(q, q->read_buf);
785 if (q->irqlock)
786 spin_unlock_irqrestore(q->irqlock, flags);
787 q->read_off = 0;
788 }
789
790 /* wait until capture is done */
791 retval = videobuf_waiton(q->read_buf, nonblocking, 1);
792 if (0 != retval)
793 goto done;
794
795 CALL(q, sync, q, q->read_buf);
796
797 if (VIDEOBUF_ERROR == q->read_buf->state) {
798 /* catch I/O errors */
799 q->ops->buf_release(q, q->read_buf);
800 kfree(q->read_buf);
801 q->read_buf = NULL;
802 retval = -EIO;
803 goto done;
804 }
805
806 /* Copy to userspace */
807 retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
808 if (retval < 0)
809 goto done;
810
811 q->read_off += retval;
812 if (q->read_off == q->read_buf->size) {
813 /* all data copied, cleanup */
814 q->ops->buf_release(q, q->read_buf);
815 kfree(q->read_buf);
816 q->read_buf = NULL;
817 }
818
819 done:
820 mutex_unlock(&q->vb_lock);
821 return retval;
822 }
823
824 /* Locking: Caller holds q->vb_lock */
825 static int __videobuf_read_start(struct videobuf_queue *q)
826 {
827 enum v4l2_field field;
828 unsigned long flags = 0;
829 unsigned int count = 0, size = 0;
830 int err, i;
831
832 q->ops->buf_setup(q, &count, &size);
833 if (count < 2)
834 count = 2;
835 if (count > VIDEO_MAX_FRAME)
836 count = VIDEO_MAX_FRAME;
837 size = PAGE_ALIGN(size);
838
839 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
840 if (err < 0)
841 return err;
842
843 count = err;
844
845 for (i = 0; i < count; i++) {
846 field = videobuf_next_field(q);
847 err = q->ops->buf_prepare(q, q->bufs[i], field);
848 if (err)
849 return err;
850 list_add_tail(&q->bufs[i]->stream, &q->stream);
851 }
852 if (q->irqlock)
853 spin_lock_irqsave(q->irqlock, flags);
854 for (i = 0; i < count; i++)
855 q->ops->buf_queue(q, q->bufs[i]);
856 if (q->irqlock)
857 spin_unlock_irqrestore(q->irqlock, flags);
858 q->reading = 1;
859 return 0;
860 }
861
862 static void __videobuf_read_stop(struct videobuf_queue *q)
863 {
864 int i;
865
866
867 videobuf_queue_cancel(q);
868 __videobuf_mmap_free(q);
869 INIT_LIST_HEAD(&q->stream);
870 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
871 if (NULL == q->bufs[i])
872 continue;
873 kfree(q->bufs[i]);
874 q->bufs[i] = NULL;
875 }
876 q->read_buf = NULL;
877 q->reading = 0;
878
879 }
880
881 int videobuf_read_start(struct videobuf_queue *q)
882 {
883 int rc;
884
885 mutex_lock(&q->vb_lock);
886 rc = __videobuf_read_start(q);
887 mutex_unlock(&q->vb_lock);
888
889 return rc;
890 }
891
892 void videobuf_read_stop(struct videobuf_queue *q)
893 {
894 mutex_lock(&q->vb_lock);
895 __videobuf_read_stop(q);
896 mutex_unlock(&q->vb_lock);
897 }
898
899 void videobuf_stop(struct videobuf_queue *q)
900 {
901 mutex_lock(&q->vb_lock);
902
903 if (q->streaming)
904 __videobuf_streamoff(q);
905
906 if (q->reading)
907 __videobuf_read_stop(q);
908
909 mutex_unlock(&q->vb_lock);
910 }
911
912
913 ssize_t videobuf_read_stream(struct videobuf_queue *q,
914 char __user *data, size_t count, loff_t *ppos,
915 int vbihack, int nonblocking)
916 {
917 int rc, retval;
918 unsigned long flags = 0;
919
920 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
921
922 dprintk(2, "%s\n", __FUNCTION__);
923 mutex_lock(&q->vb_lock);
924 retval = -EBUSY;
925 if (q->streaming)
926 goto done;
927 if (!q->reading) {
928 retval = __videobuf_read_start(q);
929 if (retval < 0)
930 goto done;
931 }
932
933 retval = 0;
934 while (count > 0) {
935 /* get / wait for data */
936 if (NULL == q->read_buf) {
937 q->read_buf = list_entry(q->stream.next,
938 struct videobuf_buffer,
939 stream);
940 list_del(&q->read_buf->stream);
941 q->read_off = 0;
942 }
943 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
944 if (rc < 0) {
945 if (0 == retval)
946 retval = rc;
947 break;
948 }
949
950 if (q->read_buf->state == VIDEOBUF_DONE) {
951 rc = CALL(q, copy_stream, q, data + retval, count,
952 retval, vbihack, nonblocking);
953 if (rc < 0) {
954 retval = rc;
955 break;
956 }
957 retval += rc;
958 count -= rc;
959 q->read_off += rc;
960 } else {
961 /* some error */
962 q->read_off = q->read_buf->size;
963 if (0 == retval)
964 retval = -EIO;
965 }
966
967 /* requeue buffer when done with copying */
968 if (q->read_off == q->read_buf->size) {
969 list_add_tail(&q->read_buf->stream,
970 &q->stream);
971 if (q->irqlock)
972 spin_lock_irqsave(q->irqlock, flags);
973 q->ops->buf_queue(q, q->read_buf);
974 if (q->irqlock)
975 spin_unlock_irqrestore(q->irqlock, flags);
976 q->read_buf = NULL;
977 }
978 if (retval < 0)
979 break;
980 }
981
982 done:
983 mutex_unlock(&q->vb_lock);
984 return retval;
985 }
986
987 unsigned int videobuf_poll_stream(struct file *file,
988 struct videobuf_queue *q,
989 poll_table *wait)
990 {
991 struct videobuf_buffer *buf = NULL;
992 unsigned int rc = 0;
993
994 mutex_lock(&q->vb_lock);
995 if (q->streaming) {
996 if (!list_empty(&q->stream))
997 buf = list_entry(q->stream.next,
998 struct videobuf_buffer, stream);
999 } else {
1000 if (!q->reading)
1001 __videobuf_read_start(q);
1002 if (!q->reading) {
1003 rc = POLLERR;
1004 } else if (NULL == q->read_buf) {
1005 q->read_buf = list_entry(q->stream.next,
1006 struct videobuf_buffer,
1007 stream);
1008 list_del(&q->read_buf->stream);
1009 q->read_off = 0;
1010 }
1011 buf = q->read_buf;
1012 }
1013 if (!buf)
1014 rc = POLLERR;
1015
1016 if (0 == rc) {
1017 poll_wait(file, &buf->done, wait);
1018 if (buf->state == VIDEOBUF_DONE ||
1019 buf->state == VIDEOBUF_ERROR)
1020 rc = POLLIN|POLLRDNORM;
1021 }
1022 mutex_unlock(&q->vb_lock);
1023 return rc;
1024 }
1025
1026 int videobuf_mmap_mapper(struct videobuf_queue *q,
1027 struct vm_area_struct *vma)
1028 {
1029 int retval;
1030
1031 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1032
1033 mutex_lock(&q->vb_lock);
1034 retval = CALL(q, mmap_mapper, q, vma);
1035 q->is_mmapped = 1;
1036 mutex_unlock(&q->vb_lock);
1037
1038 return retval;
1039 }
1040
1041 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1042 int videobuf_cgmbuf(struct videobuf_queue *q,
1043 struct video_mbuf *mbuf, int count)
1044 {
1045 struct v4l2_requestbuffers req;
1046 int rc, i;
1047
1048 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1049
1050 memset(&req, 0, sizeof(req));
1051 req.type = q->type;
1052 req.count = count;
1053 req.memory = V4L2_MEMORY_MMAP;
1054 rc = videobuf_reqbufs(q, &req);
1055 if (rc < 0)
1056 return rc;
1057
1058 mbuf->frames = req.count;
1059 mbuf->size = 0;
1060 for (i = 0; i < mbuf->frames; i++) {
1061 mbuf->offsets[i] = q->bufs[i]->boff;
1062 mbuf->size += q->bufs[i]->bsize;
1063 }
1064
1065 return 0;
1066 }
1067 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1068 #endif
1069
1070 /* --------------------------------------------------------------------- */
1071
1072 EXPORT_SYMBOL_GPL(videobuf_waiton);
1073 EXPORT_SYMBOL_GPL(videobuf_iolock);
1074
1075 EXPORT_SYMBOL_GPL(videobuf_alloc);
1076
1077 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1078 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1079 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1080
1081 EXPORT_SYMBOL_GPL(videobuf_next_field);
1082 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1083 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1084 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1085 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1086 EXPORT_SYMBOL_GPL(videobuf_streamon);
1087 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1088
1089 EXPORT_SYMBOL_GPL(videobuf_read_start);
1090 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1091 EXPORT_SYMBOL_GPL(videobuf_stop);
1092 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1093 EXPORT_SYMBOL_GPL(videobuf_read_one);
1094 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1095
1096 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1097 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1098 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
Linux kernel - Deliverables
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