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Fix a deadlock in the bttv driver
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / media / video / videobuf-core.c
blob0a88c44ace00b20199e8606cef813234d39e5c74
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 #define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
68 vb->state != VIDEOBUF_QUEUED)
69 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
70 {
71 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
72
73 if (non_blocking) {
74 if (WAITON_CONDITION)
75 return 0;
76 else
77 return -EAGAIN;
78 }
79
80 if (intr)
81 return wait_event_interruptible(vb->done, WAITON_CONDITION);
82 else
83 wait_event(vb->done, WAITON_CONDITION);
84
85 return 0;
86 }
87
88 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
89 struct v4l2_framebuffer *fbuf)
90 {
91 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
92 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
93
94 return CALL(q, iolock, q, vb, fbuf);
95 }
96
97 void *videobuf_queue_to_vmalloc (struct videobuf_queue *q,
98 struct videobuf_buffer *buf)
99 {
100 if (q->int_ops->vmalloc)
101 return q->int_ops->vmalloc(buf);
102 else
103 return NULL;
104 }
105 EXPORT_SYMBOL_GPL(videobuf_queue_to_vmalloc);
106
107 /* --------------------------------------------------------------------- */
108
109
110 void videobuf_queue_core_init(struct videobuf_queue *q,
111 struct videobuf_queue_ops *ops,
112 struct device *dev,
113 spinlock_t *irqlock,
114 enum v4l2_buf_type type,
115 enum v4l2_field field,
116 unsigned int msize,
117 void *priv,
118 struct videobuf_qtype_ops *int_ops)
119 {
120 memset(q, 0, sizeof(*q));
121 q->irqlock = irqlock;
122 q->dev = dev;
123 q->type = type;
124 q->field = field;
125 q->msize = msize;
126 q->ops = ops;
127 q->priv_data = priv;
128 q->int_ops = int_ops;
129
130 /* All buffer operations are mandatory */
131 BUG_ON(!q->ops->buf_setup);
132 BUG_ON(!q->ops->buf_prepare);
133 BUG_ON(!q->ops->buf_queue);
134 BUG_ON(!q->ops->buf_release);
135
136 /* Lock is mandatory for queue_cancel to work */
137 BUG_ON(!irqlock);
138
139 /* Having implementations for abstract methods are mandatory */
140 BUG_ON(!q->int_ops);
141
142 mutex_init(&q->vb_lock);
143 init_waitqueue_head(&q->wait);
144 INIT_LIST_HEAD(&q->stream);
145 }
146
147 /* Locking: Only usage in bttv unsafe find way to remove */
148 int videobuf_queue_is_busy(struct videobuf_queue *q)
149 {
150 int i;
151
152 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
153
154 if (q->streaming) {
155 dprintk(1, "busy: streaming active\n");
156 return 1;
157 }
158 if (q->reading) {
159 dprintk(1, "busy: pending read #1\n");
160 return 1;
161 }
162 if (q->read_buf) {
163 dprintk(1, "busy: pending read #2\n");
164 return 1;
165 }
166 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
167 if (NULL == q->bufs[i])
168 continue;
169 if (q->bufs[i]->map) {
170 dprintk(1, "busy: buffer #%d mapped\n", i);
171 return 1;
172 }
173 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
174 dprintk(1, "busy: buffer #%d queued\n", i);
175 return 1;
176 }
177 if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
178 dprintk(1, "busy: buffer #%d avtive\n", i);
179 return 1;
180 }
181 }
182 return 0;
183 }
184
185 /* Locking: Caller holds q->vb_lock */
186 void videobuf_queue_cancel(struct videobuf_queue *q)
187 {
188 unsigned long flags = 0;
189 int i;
190
191 q->streaming = 0;
192 q->reading = 0;
193 wake_up_interruptible_sync(&q->wait);
194
195 /* remove queued buffers from list */
196 spin_lock_irqsave(q->irqlock, flags);
197 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
198 if (NULL == q->bufs[i])
199 continue;
200 if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
201 list_del(&q->bufs[i]->queue);
202 q->bufs[i]->state = VIDEOBUF_ERROR;
203 wake_up_all(&q->bufs[i]->done);
204 }
205 }
206 spin_unlock_irqrestore(q->irqlock, flags);
207
208 /* free all buffers + clear queue */
209 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
210 if (NULL == q->bufs[i])
211 continue;
212 q->ops->buf_release(q, q->bufs[i]);
213 }
214 INIT_LIST_HEAD(&q->stream);
215 }
216
217 /* --------------------------------------------------------------------- */
218
219 /* Locking: Caller holds q->vb_lock */
220 enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
221 {
222 enum v4l2_field field = q->field;
223
224 BUG_ON(V4L2_FIELD_ANY == field);
225
226 if (V4L2_FIELD_ALTERNATE == field) {
227 if (V4L2_FIELD_TOP == q->last) {
228 field = V4L2_FIELD_BOTTOM;
229 q->last = V4L2_FIELD_BOTTOM;
230 } else {
231 field = V4L2_FIELD_TOP;
232 q->last = V4L2_FIELD_TOP;
233 }
234 }
235 return field;
236 }
237
238 /* Locking: Caller holds q->vb_lock */
239 static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
240 struct videobuf_buffer *vb, enum v4l2_buf_type type)
241 {
242 MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
243 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
244
245 b->index = vb->i;
246 b->type = type;
247
248 b->memory = vb->memory;
249 switch (b->memory) {
250 case V4L2_MEMORY_MMAP:
251 b->m.offset = vb->boff;
252 b->length = vb->bsize;
253 break;
254 case V4L2_MEMORY_USERPTR:
255 b->m.userptr = vb->baddr;
256 b->length = vb->bsize;
257 break;
258 case V4L2_MEMORY_OVERLAY:
259 b->m.offset = vb->boff;
260 break;
261 }
262
263 b->flags = 0;
264 if (vb->map)
265 b->flags |= V4L2_BUF_FLAG_MAPPED;
266
267 switch (vb->state) {
268 case VIDEOBUF_PREPARED:
269 case VIDEOBUF_QUEUED:
270 case VIDEOBUF_ACTIVE:
271 b->flags |= V4L2_BUF_FLAG_QUEUED;
272 break;
273 case VIDEOBUF_DONE:
274 case VIDEOBUF_ERROR:
275 b->flags |= V4L2_BUF_FLAG_DONE;
276 break;
277 case VIDEOBUF_NEEDS_INIT:
278 case VIDEOBUF_IDLE:
279 /* nothing */
280 break;
281 }
282
283 if (vb->input != UNSET) {
284 b->flags |= V4L2_BUF_FLAG_INPUT;
285 b->input = vb->input;
286 }
287
288 b->field = vb->field;
289 b->timestamp = vb->ts;
290 b->bytesused = vb->size;
291 b->sequence = vb->field_count >> 1;
292 }
293
294 /* Locking: Caller holds q->vb_lock */
295 static int __videobuf_mmap_free(struct videobuf_queue *q)
296 {
297 int i;
298 int rc;
299
300 if (!q)
301 return 0;
302
303 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
304
305
306 rc = CALL(q, mmap_free, q);
307
308 q->is_mmapped = 0;
309
310 if (rc < 0)
311 return rc;
312
313 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
314 if (NULL == q->bufs[i])
315 continue;
316 q->ops->buf_release(q, q->bufs[i]);
317 kfree(q->bufs[i]);
318 q->bufs[i] = NULL;
319 }
320
321 return rc;
322 }
323
324 int videobuf_mmap_free(struct videobuf_queue *q)
325 {
326 int ret;
327 mutex_lock(&q->vb_lock);
328 ret = __videobuf_mmap_free(q);
329 mutex_unlock(&q->vb_lock);
330 return ret;
331 }
332
333 /* Locking: Caller holds q->vb_lock */
334 int __videobuf_mmap_setup(struct videobuf_queue *q,
335 unsigned int bcount, unsigned int bsize,
336 enum v4l2_memory memory)
337 {
338 unsigned int i;
339 int err;
340
341 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
342
343 err = __videobuf_mmap_free(q);
344 if (0 != err)
345 return err;
346
347 /* Allocate and initialize buffers */
348 for (i = 0; i < bcount; i++) {
349 q->bufs[i] = videobuf_alloc(q);
350
351 if (q->bufs[i] == NULL)
352 break;
353
354 q->bufs[i]->i = i;
355 q->bufs[i]->input = UNSET;
356 q->bufs[i]->memory = memory;
357 q->bufs[i]->bsize = bsize;
358 switch (memory) {
359 case V4L2_MEMORY_MMAP:
360 q->bufs[i]->boff = bsize * i;
361 break;
362 case V4L2_MEMORY_USERPTR:
363 case V4L2_MEMORY_OVERLAY:
364 /* nothing */
365 break;
366 }
367 }
368
369 if (!i)
370 return -ENOMEM;
371
372 dprintk(1, "mmap setup: %d buffers, %d bytes each\n",
373 i, bsize);
374
375 return i;
376 }
377
378 int videobuf_mmap_setup(struct videobuf_queue *q,
379 unsigned int bcount, unsigned int bsize,
380 enum v4l2_memory memory)
381 {
382 int ret;
383 mutex_lock(&q->vb_lock);
384 ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
385 mutex_unlock(&q->vb_lock);
386 return ret;
387 }
388
389 int videobuf_reqbufs(struct videobuf_queue *q,
390 struct v4l2_requestbuffers *req)
391 {
392 unsigned int size, count;
393 int retval;
394
395 if (req->count < 1) {
396 dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
397 return -EINVAL;
398 }
399
400 if (req->memory != V4L2_MEMORY_MMAP &&
401 req->memory != V4L2_MEMORY_USERPTR &&
402 req->memory != V4L2_MEMORY_OVERLAY) {
403 dprintk(1, "reqbufs: memory type invalid\n");
404 return -EINVAL;
405 }
406
407 mutex_lock(&q->vb_lock);
408 if (req->type != q->type) {
409 dprintk(1, "reqbufs: queue type invalid\n");
410 retval = -EINVAL;
411 goto done;
412 }
413
414 if (q->streaming) {
415 dprintk(1, "reqbufs: streaming already exists\n");
416 retval = -EBUSY;
417 goto done;
418 }
419 if (!list_empty(&q->stream)) {
420 dprintk(1, "reqbufs: stream running\n");
421 retval = -EBUSY;
422 goto done;
423 }
424
425 count = req->count;
426 if (count > VIDEO_MAX_FRAME)
427 count = VIDEO_MAX_FRAME;
428 size = 0;
429 q->ops->buf_setup(q, &count, &size);
430 size = PAGE_ALIGN(size);
431 dprintk(1, "reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
432 count, size, (count*size)>>PAGE_SHIFT);
433
434 retval = __videobuf_mmap_setup(q, count, size, req->memory);
435 if (retval < 0) {
436 dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
437 goto done;
438 }
439
440 req->count = retval;
441
442 done:
443 mutex_unlock(&q->vb_lock);
444 return retval;
445 }
446
447 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
448 {
449 int ret = -EINVAL;
450
451 mutex_lock(&q->vb_lock);
452 if (unlikely(b->type != q->type)) {
453 dprintk(1, "querybuf: Wrong type.\n");
454 goto done;
455 }
456 if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
457 dprintk(1, "querybuf: index out of range.\n");
458 goto done;
459 }
460 if (unlikely(NULL == q->bufs[b->index])) {
461 dprintk(1, "querybuf: buffer is null.\n");
462 goto done;
463 }
464
465 videobuf_status(q, b, q->bufs[b->index], q->type);
466
467 ret = 0;
468 done:
469 mutex_unlock(&q->vb_lock);
470 return ret;
471 }
472
473 int videobuf_qbuf(struct videobuf_queue *q,
474 struct v4l2_buffer *b)
475 {
476 struct videobuf_buffer *buf;
477 enum v4l2_field field;
478 unsigned long flags = 0;
479 int retval;
480
481 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
482
483 if (b->memory == V4L2_MEMORY_MMAP)
484 down_read(&current->mm->mmap_sem);
485
486 mutex_lock(&q->vb_lock);
487 retval = -EBUSY;
488 if (q->reading) {
489 dprintk(1, "qbuf: Reading running...\n");
490 goto done;
491 }
492 retval = -EINVAL;
493 if (b->type != q->type) {
494 dprintk(1, "qbuf: Wrong type.\n");
495 goto done;
496 }
497 if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
498 dprintk(1, "qbuf: index out of range.\n");
499 goto done;
500 }
501 buf = q->bufs[b->index];
502 if (NULL == buf) {
503 dprintk(1, "qbuf: buffer is null.\n");
504 goto done;
505 }
506 MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
507 if (buf->memory != b->memory) {
508 dprintk(1, "qbuf: memory type is wrong.\n");
509 goto done;
510 }
511 if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
512 dprintk(1, "qbuf: buffer is already queued or active.\n");
513 goto done;
514 }
515
516 if (b->flags & V4L2_BUF_FLAG_INPUT) {
517 if (b->input >= q->inputs) {
518 dprintk(1, "qbuf: wrong input.\n");
519 goto done;
520 }
521 buf->input = b->input;
522 } else {
523 buf->input = UNSET;
524 }
525
526 switch (b->memory) {
527 case V4L2_MEMORY_MMAP:
528 if (0 == buf->baddr) {
529 dprintk(1, "qbuf: mmap requested "
530 "but buffer addr is zero!\n");
531 goto done;
532 }
533 break;
534 case V4L2_MEMORY_USERPTR:
535 if (b->length < buf->bsize) {
536 dprintk(1, "qbuf: buffer length is not enough\n");
537 goto done;
538 }
539 if (VIDEOBUF_NEEDS_INIT != buf->state &&
540 buf->baddr != b->m.userptr)
541 q->ops->buf_release(q, buf);
542 buf->baddr = b->m.userptr;
543 break;
544 case V4L2_MEMORY_OVERLAY:
545 buf->boff = b->m.offset;
546 break;
547 default:
548 dprintk(1, "qbuf: wrong memory type\n");
549 goto done;
550 }
551
552 dprintk(1, "qbuf: requesting next field\n");
553 field = videobuf_next_field(q);
554 retval = q->ops->buf_prepare(q, buf, field);
555 if (0 != retval) {
556 dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
557 goto done;
558 }
559
560 list_add_tail(&buf->stream, &q->stream);
561 if (q->streaming) {
562 spin_lock_irqsave(q->irqlock, flags);
563 q->ops->buf_queue(q, buf);
564 spin_unlock_irqrestore(q->irqlock, flags);
565 }
566 dprintk(1, "qbuf: succeded\n");
567 retval = 0;
568 wake_up_interruptible_sync(&q->wait);
569
570 done:
571 mutex_unlock(&q->vb_lock);
572
573 if (b->memory == V4L2_MEMORY_MMAP)
574 up_read(&current->mm->mmap_sem);
575
576 return retval;
577 }
578
579
580 /* Locking: Caller holds q->vb_lock */
581 static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
582 {
583 int retval;
584
585 checks:
586 if (!q->streaming) {
587 dprintk(1, "next_buffer: Not streaming\n");
588 retval = -EINVAL;
589 goto done;
590 }
591
592 if (list_empty(&q->stream)) {
593 if (noblock) {
594 retval = -EAGAIN;
595 dprintk(2, "next_buffer: no buffers to dequeue\n");
596 goto done;
597 } else {
598 dprintk(2, "next_buffer: waiting on buffer\n");
599
600 /* Drop lock to avoid deadlock with qbuf */
601 mutex_unlock(&q->vb_lock);
602
603 /* Checking list_empty and streaming is safe without
604 * locks because we goto checks to validate while
605 * holding locks before proceeding */
606 retval = wait_event_interruptible(q->wait,
607 !list_empty(&q->stream) || !q->streaming);
608 mutex_lock(&q->vb_lock);
609
610 if (retval)
611 goto done;
612
613 goto checks;
614 }
615 }
616
617 retval = 0;
618
619 done:
620 return retval;
621 }
622
623
624 /* Locking: Caller holds q->vb_lock */
625 static int stream_next_buffer(struct videobuf_queue *q,
626 struct videobuf_buffer **vb, int nonblocking)
627 {
628 int retval;
629 struct videobuf_buffer *buf = NULL;
630
631 retval = stream_next_buffer_check_queue(q, nonblocking);
632 if (retval)
633 goto done;
634
635 buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
636 retval = videobuf_waiton(buf, nonblocking, 1);
637 if (retval < 0)
638 goto done;
639
640 *vb = buf;
641 done:
642 return retval;
643 }
644
645 int videobuf_dqbuf(struct videobuf_queue *q,
646 struct v4l2_buffer *b, int nonblocking)
647 {
648 struct videobuf_buffer *buf = NULL;
649 int retval;
650
651 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
652
653 mutex_lock(&q->vb_lock);
654
655 retval = stream_next_buffer(q, &buf, nonblocking);
656 if (retval < 0) {
657 dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
658 goto done;
659 }
660
661 switch (buf->state) {
662 case VIDEOBUF_ERROR:
663 dprintk(1, "dqbuf: state is error\n");
664 retval = -EIO;
665 CALL(q, sync, q, buf);
666 buf->state = VIDEOBUF_IDLE;
667 break;
668 case VIDEOBUF_DONE:
669 dprintk(1, "dqbuf: state is done\n");
670 CALL(q, sync, q, buf);
671 buf->state = VIDEOBUF_IDLE;
672 break;
673 default:
674 dprintk(1, "dqbuf: state invalid\n");
675 retval = -EINVAL;
676 goto done;
677 }
678 list_del(&buf->stream);
679 memset(b, 0, sizeof(*b));
680 videobuf_status(q, b, buf, q->type);
681
682 done:
683 mutex_unlock(&q->vb_lock);
684 return retval;
685 }
686
687 int videobuf_streamon(struct videobuf_queue *q)
688 {
689 struct videobuf_buffer *buf;
690 unsigned long flags = 0;
691 int retval;
692
693 mutex_lock(&q->vb_lock);
694 retval = -EBUSY;
695 if (q->reading)
696 goto done;
697 retval = 0;
698 if (q->streaming)
699 goto done;
700 q->streaming = 1;
701 spin_lock_irqsave(q->irqlock, flags);
702 list_for_each_entry(buf, &q->stream, stream)
703 if (buf->state == VIDEOBUF_PREPARED)
704 q->ops->buf_queue(q, buf);
705 spin_unlock_irqrestore(q->irqlock, flags);
706
707 wake_up_interruptible_sync(&q->wait);
708 done:
709 mutex_unlock(&q->vb_lock);
710 return retval;
711 }
712
713 /* Locking: Caller holds q->vb_lock */
714 static int __videobuf_streamoff(struct videobuf_queue *q)
715 {
716 if (!q->streaming)
717 return -EINVAL;
718
719 videobuf_queue_cancel(q);
720
721 return 0;
722 }
723
724 int videobuf_streamoff(struct videobuf_queue *q)
725 {
726 int retval;
727
728 mutex_lock(&q->vb_lock);
729 retval = __videobuf_streamoff(q);
730 mutex_unlock(&q->vb_lock);
731
732 return retval;
733 }
734
735 /* Locking: Caller holds q->vb_lock */
736 static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
737 char __user *data,
738 size_t count, loff_t *ppos)
739 {
740 enum v4l2_field field;
741 unsigned long flags = 0;
742 int retval;
743
744 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
745
746 /* setup stuff */
747 q->read_buf = videobuf_alloc(q);
748 if (NULL == q->read_buf)
749 return -ENOMEM;
750
751 q->read_buf->memory = V4L2_MEMORY_USERPTR;
752 q->read_buf->baddr = (unsigned long)data;
753 q->read_buf->bsize = count;
754
755 field = videobuf_next_field(q);
756 retval = q->ops->buf_prepare(q, q->read_buf, field);
757 if (0 != retval)
758 goto done;
759
760 /* start capture & wait */
761 spin_lock_irqsave(q->irqlock, flags);
762 q->ops->buf_queue(q, q->read_buf);
763 spin_unlock_irqrestore(q->irqlock, flags);
764 retval = videobuf_waiton(q->read_buf, 0, 0);
765 if (0 == retval) {
766 CALL(q, sync, q, q->read_buf);
767 if (VIDEOBUF_ERROR == q->read_buf->state)
768 retval = -EIO;
769 else
770 retval = q->read_buf->size;
771 }
772
773 done:
774 /* cleanup */
775 q->ops->buf_release(q, q->read_buf);
776 kfree(q->read_buf);
777 q->read_buf = NULL;
778 return retval;
779 }
780
781 ssize_t videobuf_read_one(struct videobuf_queue *q,
782 char __user *data, size_t count, loff_t *ppos,
783 int nonblocking)
784 {
785 enum v4l2_field field;
786 unsigned long flags = 0;
787 unsigned size = 0, nbufs = 1;
788 int retval;
789
790 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
791
792 mutex_lock(&q->vb_lock);
793
794 q->ops->buf_setup(q, &nbufs, &size);
795
796 if (NULL == q->read_buf &&
797 count >= size &&
798 !nonblocking) {
799 retval = videobuf_read_zerocopy(q, data, count, ppos);
800 if (retval >= 0 || retval == -EIO)
801 /* ok, all done */
802 goto done;
803 /* fallback to kernel bounce buffer on failures */
804 }
805
806 if (NULL == q->read_buf) {
807 /* need to capture a new frame */
808 retval = -ENOMEM;
809 q->read_buf = videobuf_alloc(q);
810
811 dprintk(1, "video alloc=0x%p\n", q->read_buf);
812 if (NULL == q->read_buf)
813 goto done;
814 q->read_buf->memory = V4L2_MEMORY_USERPTR;
815 q->read_buf->bsize = count; /* preferred size */
816 field = videobuf_next_field(q);
817 retval = q->ops->buf_prepare(q, q->read_buf, field);
818
819 if (0 != retval) {
820 kfree(q->read_buf);
821 q->read_buf = NULL;
822 goto done;
823 }
824
825 spin_lock_irqsave(q->irqlock, flags);
826 q->ops->buf_queue(q, q->read_buf);
827 spin_unlock_irqrestore(q->irqlock, flags);
828
829 q->read_off = 0;
830 }
831
832 /* wait until capture is done */
833 retval = videobuf_waiton(q->read_buf, nonblocking, 1);
834 if (0 != retval)
835 goto done;
836
837 CALL(q, sync, q, q->read_buf);
838
839 if (VIDEOBUF_ERROR == q->read_buf->state) {
840 /* catch I/O errors */
841 q->ops->buf_release(q, q->read_buf);
842 kfree(q->read_buf);
843 q->read_buf = NULL;
844 retval = -EIO;
845 goto done;
846 }
847
848 /* Copy to userspace */
849 retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
850 if (retval < 0)
851 goto done;
852
853 q->read_off += retval;
854 if (q->read_off == q->read_buf->size) {
855 /* all data copied, cleanup */
856 q->ops->buf_release(q, q->read_buf);
857 kfree(q->read_buf);
858 q->read_buf = NULL;
859 }
860
861 done:
862 mutex_unlock(&q->vb_lock);
863 return retval;
864 }
865
866 /* Locking: Caller holds q->vb_lock */
867 static int __videobuf_read_start(struct videobuf_queue *q)
868 {
869 enum v4l2_field field;
870 unsigned long flags = 0;
871 unsigned int count = 0, size = 0;
872 int err, i;
873
874 q->ops->buf_setup(q, &count, &size);
875 if (count < 2)
876 count = 2;
877 if (count > VIDEO_MAX_FRAME)
878 count = VIDEO_MAX_FRAME;
879 size = PAGE_ALIGN(size);
880
881 err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
882 if (err < 0)
883 return err;
884
885 count = err;
886
887 for (i = 0; i < count; i++) {
888 field = videobuf_next_field(q);
889 err = q->ops->buf_prepare(q, q->bufs[i], field);
890 if (err)
891 return err;
892 list_add_tail(&q->bufs[i]->stream, &q->stream);
893 }
894 spin_lock_irqsave(q->irqlock, flags);
895 for (i = 0; i < count; i++)
896 q->ops->buf_queue(q, q->bufs[i]);
897 spin_unlock_irqrestore(q->irqlock, flags);
898 q->reading = 1;
899 return 0;
900 }
901
902 static void __videobuf_read_stop(struct videobuf_queue *q)
903 {
904 int i;
905
906 videobuf_queue_cancel(q);
907 __videobuf_mmap_free(q);
908 INIT_LIST_HEAD(&q->stream);
909 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
910 if (NULL == q->bufs[i])
911 continue;
912 kfree(q->bufs[i]);
913 q->bufs[i] = NULL;
914 }
915 q->read_buf = NULL;
916
917 }
918
919 int videobuf_read_start(struct videobuf_queue *q)
920 {
921 int rc;
922
923 mutex_lock(&q->vb_lock);
924 rc = __videobuf_read_start(q);
925 mutex_unlock(&q->vb_lock);
926
927 return rc;
928 }
929
930 void videobuf_read_stop(struct videobuf_queue *q)
931 {
932 mutex_lock(&q->vb_lock);
933 __videobuf_read_stop(q);
934 mutex_unlock(&q->vb_lock);
935 }
936
937 void videobuf_stop(struct videobuf_queue *q)
938 {
939 mutex_lock(&q->vb_lock);
940
941 if (q->streaming)
942 __videobuf_streamoff(q);
943
944 if (q->reading)
945 __videobuf_read_stop(q);
946
947 mutex_unlock(&q->vb_lock);
948 }
949
950
951 ssize_t videobuf_read_stream(struct videobuf_queue *q,
952 char __user *data, size_t count, loff_t *ppos,
953 int vbihack, int nonblocking)
954 {
955 int rc, retval;
956 unsigned long flags = 0;
957
958 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
959
960 dprintk(2, "%s\n", __func__);
961 mutex_lock(&q->vb_lock);
962 retval = -EBUSY;
963 if (q->streaming)
964 goto done;
965 if (!q->reading) {
966 retval = __videobuf_read_start(q);
967 if (retval < 0)
968 goto done;
969 }
970
971 retval = 0;
972 while (count > 0) {
973 /* get / wait for data */
974 if (NULL == q->read_buf) {
975 q->read_buf = list_entry(q->stream.next,
976 struct videobuf_buffer,
977 stream);
978 list_del(&q->read_buf->stream);
979 q->read_off = 0;
980 }
981 rc = videobuf_waiton(q->read_buf, nonblocking, 1);
982 if (rc < 0) {
983 if (0 == retval)
984 retval = rc;
985 break;
986 }
987
988 if (q->read_buf->state == VIDEOBUF_DONE) {
989 rc = CALL(q, copy_stream, q, data + retval, count,
990 retval, vbihack, nonblocking);
991 if (rc < 0) {
992 retval = rc;
993 break;
994 }
995 retval += rc;
996 count -= rc;
997 q->read_off += rc;
998 } else {
999 /* some error */
1000 q->read_off = q->read_buf->size;
1001 if (0 == retval)
1002 retval = -EIO;
1003 }
1004
1005 /* requeue buffer when done with copying */
1006 if (q->read_off == q->read_buf->size) {
1007 list_add_tail(&q->read_buf->stream,
1008 &q->stream);
1009 spin_lock_irqsave(q->irqlock, flags);
1010 q->ops->buf_queue(q, q->read_buf);
1011 spin_unlock_irqrestore(q->irqlock, flags);
1012 q->read_buf = NULL;
1013 }
1014 if (retval < 0)
1015 break;
1016 }
1017
1018 done:
1019 mutex_unlock(&q->vb_lock);
1020 return retval;
1021 }
1022
1023 unsigned int videobuf_poll_stream(struct file *file,
1024 struct videobuf_queue *q,
1025 poll_table *wait)
1026 {
1027 struct videobuf_buffer *buf = NULL;
1028 unsigned int rc = 0;
1029
1030 mutex_lock(&q->vb_lock);
1031 if (q->streaming) {
1032 if (!list_empty(&q->stream))
1033 buf = list_entry(q->stream.next,
1034 struct videobuf_buffer, stream);
1035 } else {
1036 if (!q->reading)
1037 __videobuf_read_start(q);
1038 if (!q->reading) {
1039 rc = POLLERR;
1040 } else if (NULL == q->read_buf) {
1041 q->read_buf = list_entry(q->stream.next,
1042 struct videobuf_buffer,
1043 stream);
1044 list_del(&q->read_buf->stream);
1045 q->read_off = 0;
1046 }
1047 buf = q->read_buf;
1048 }
1049 if (!buf)
1050 rc = POLLERR;
1051
1052 if (0 == rc) {
1053 poll_wait(file, &buf->done, wait);
1054 if (buf->state == VIDEOBUF_DONE ||
1055 buf->state == VIDEOBUF_ERROR)
1056 rc = POLLIN|POLLRDNORM;
1057 }
1058 mutex_unlock(&q->vb_lock);
1059 return rc;
1060 }
1061
1062 int videobuf_mmap_mapper(struct videobuf_queue *q,
1063 struct vm_area_struct *vma)
1064 {
1065 int retval;
1066
1067 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1068
1069 mutex_lock(&q->vb_lock);
1070 retval = CALL(q, mmap_mapper, q, vma);
1071 q->is_mmapped = 1;
1072 mutex_unlock(&q->vb_lock);
1073
1074 return retval;
1075 }
1076
1077 #ifdef CONFIG_VIDEO_V4L1_COMPAT
1078 int videobuf_cgmbuf(struct videobuf_queue *q,
1079 struct video_mbuf *mbuf, int count)
1080 {
1081 struct v4l2_requestbuffers req;
1082 int rc, i;
1083
1084 MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
1085
1086 memset(&req, 0, sizeof(req));
1087 req.type = q->type;
1088 req.count = count;
1089 req.memory = V4L2_MEMORY_MMAP;
1090 rc = videobuf_reqbufs(q, &req);
1091 if (rc < 0)
1092 return rc;
1093
1094 mbuf->frames = req.count;
1095 mbuf->size = 0;
1096 for (i = 0; i < mbuf->frames; i++) {
1097 mbuf->offsets[i] = q->bufs[i]->boff;
1098 mbuf->size += q->bufs[i]->bsize;
1099 }
1100
1101 return 0;
1102 }
1103 EXPORT_SYMBOL_GPL(videobuf_cgmbuf);
1104 #endif
1105
1106 /* --------------------------------------------------------------------- */
1107
1108 EXPORT_SYMBOL_GPL(videobuf_waiton);
1109 EXPORT_SYMBOL_GPL(videobuf_iolock);
1110
1111 EXPORT_SYMBOL_GPL(videobuf_alloc);
1112
1113 EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
1114 EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
1115 EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
1116
1117 EXPORT_SYMBOL_GPL(videobuf_next_field);
1118 EXPORT_SYMBOL_GPL(videobuf_reqbufs);
1119 EXPORT_SYMBOL_GPL(videobuf_querybuf);
1120 EXPORT_SYMBOL_GPL(videobuf_qbuf);
1121 EXPORT_SYMBOL_GPL(videobuf_dqbuf);
1122 EXPORT_SYMBOL_GPL(videobuf_streamon);
1123 EXPORT_SYMBOL_GPL(videobuf_streamoff);
1124
1125 EXPORT_SYMBOL_GPL(videobuf_read_start);
1126 EXPORT_SYMBOL_GPL(videobuf_read_stop);
1127 EXPORT_SYMBOL_GPL(videobuf_stop);
1128 EXPORT_SYMBOL_GPL(videobuf_read_stream);
1129 EXPORT_SYMBOL_GPL(videobuf_read_one);
1130 EXPORT_SYMBOL_GPL(videobuf_poll_stream);
1131
1132 EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
1133 EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
1134 EXPORT_SYMBOL_GPL(videobuf_mmap_free);
1135 EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree