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[media] Revert "[media] vb2: Push mmap_sem down to memops"
[deliverable/linux.git] / drivers / media / v4l2-core / videobuf2-core.c
1 /*
2 * videobuf2-core.c - V4L2 driver helper framework
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 *
6 * Author: Pawel Osciak <pawel@osciak.com>
7 * Marek Szyprowski <m.szyprowski@samsung.com>
8 *
9 * The vb2_thread implementation was based on code from videobuf-dvb.c:
10 * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation.
15 */
16
17 #include <linux/err.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/mm.h>
21 #include <linux/poll.h>
22 #include <linux/slab.h>
23 #include <linux/sched.h>
24 #include <linux/freezer.h>
25 #include <linux/kthread.h>
26
27 #include <media/v4l2-dev.h>
28 #include <media/v4l2-fh.h>
29 #include <media/v4l2-event.h>
30 #include <media/v4l2-common.h>
31 #include <media/videobuf2-core.h>
32
33 static int debug;
34 module_param(debug, int, 0644);
35
36 #define dprintk(level, fmt, arg...) \
37 do { \
38 if (debug >= level) \
39 pr_info("vb2: %s: " fmt, __func__, ## arg); \
40 } while (0)
41
42 #ifdef CONFIG_VIDEO_ADV_DEBUG
43
44 /*
45 * If advanced debugging is on, then count how often each op is called
46 * successfully, which can either be per-buffer or per-queue.
47 *
48 * This makes it easy to check that the 'init' and 'cleanup'
49 * (and variations thereof) stay balanced.
50 */
51
52 #define log_memop(vb, op) \
53 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
54 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
55 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
56
57 #define call_memop(vb, op, args...) \
58 ({ \
59 struct vb2_queue *_q = (vb)->vb2_queue; \
60 int err; \
61 \
62 log_memop(vb, op); \
63 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
64 if (!err) \
65 (vb)->cnt_mem_ ## op++; \
66 err; \
67 })
68
69 #define call_ptr_memop(vb, op, args...) \
70 ({ \
71 struct vb2_queue *_q = (vb)->vb2_queue; \
72 void *ptr; \
73 \
74 log_memop(vb, op); \
75 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
76 if (!IS_ERR_OR_NULL(ptr)) \
77 (vb)->cnt_mem_ ## op++; \
78 ptr; \
79 })
80
81 #define call_void_memop(vb, op, args...) \
82 ({ \
83 struct vb2_queue *_q = (vb)->vb2_queue; \
84 \
85 log_memop(vb, op); \
86 if (_q->mem_ops->op) \
87 _q->mem_ops->op(args); \
88 (vb)->cnt_mem_ ## op++; \
89 })
90
91 #define log_qop(q, op) \
92 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
93 (q)->ops->op ? "" : " (nop)")
94
95 #define call_qop(q, op, args...) \
96 ({ \
97 int err; \
98 \
99 log_qop(q, op); \
100 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
101 if (!err) \
102 (q)->cnt_ ## op++; \
103 err; \
104 })
105
106 #define call_void_qop(q, op, args...) \
107 ({ \
108 log_qop(q, op); \
109 if ((q)->ops->op) \
110 (q)->ops->op(args); \
111 (q)->cnt_ ## op++; \
112 })
113
114 #define log_vb_qop(vb, op, args...) \
115 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
116 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
117 (vb)->vb2_queue->ops->op ? "" : " (nop)")
118
119 #define call_vb_qop(vb, op, args...) \
120 ({ \
121 int err; \
122 \
123 log_vb_qop(vb, op); \
124 err = (vb)->vb2_queue->ops->op ? \
125 (vb)->vb2_queue->ops->op(args) : 0; \
126 if (!err) \
127 (vb)->cnt_ ## op++; \
128 err; \
129 })
130
131 #define call_void_vb_qop(vb, op, args...) \
132 ({ \
133 log_vb_qop(vb, op); \
134 if ((vb)->vb2_queue->ops->op) \
135 (vb)->vb2_queue->ops->op(args); \
136 (vb)->cnt_ ## op++; \
137 })
138
139 #else
140
141 #define call_memop(vb, op, args...) \
142 ((vb)->vb2_queue->mem_ops->op ? \
143 (vb)->vb2_queue->mem_ops->op(args) : 0)
144
145 #define call_ptr_memop(vb, op, args...) \
146 ((vb)->vb2_queue->mem_ops->op ? \
147 (vb)->vb2_queue->mem_ops->op(args) : NULL)
148
149 #define call_void_memop(vb, op, args...) \
150 do { \
151 if ((vb)->vb2_queue->mem_ops->op) \
152 (vb)->vb2_queue->mem_ops->op(args); \
153 } while (0)
154
155 #define call_qop(q, op, args...) \
156 ((q)->ops->op ? (q)->ops->op(args) : 0)
157
158 #define call_void_qop(q, op, args...) \
159 do { \
160 if ((q)->ops->op) \
161 (q)->ops->op(args); \
162 } while (0)
163
164 #define call_vb_qop(vb, op, args...) \
165 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
166
167 #define call_void_vb_qop(vb, op, args...) \
168 do { \
169 if ((vb)->vb2_queue->ops->op) \
170 (vb)->vb2_queue->ops->op(args); \
171 } while (0)
172
173 #endif
174
175 /* Flags that are set by the vb2 core */
176 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
177 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
178 V4L2_BUF_FLAG_PREPARED | \
179 V4L2_BUF_FLAG_TIMESTAMP_MASK)
180 /* Output buffer flags that should be passed on to the driver */
181 #define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
182 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
183
184 static void __vb2_queue_cancel(struct vb2_queue *q);
185 static void __enqueue_in_driver(struct vb2_buffer *vb);
186
187 /**
188 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
189 */
190 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
191 {
192 struct vb2_queue *q = vb->vb2_queue;
193 enum dma_data_direction dma_dir =
194 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
195 void *mem_priv;
196 int plane;
197
198 /*
199 * Allocate memory for all planes in this buffer
200 * NOTE: mmapped areas should be page aligned
201 */
202 for (plane = 0; plane < vb->num_planes; ++plane) {
203 unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
204
205 mem_priv = call_ptr_memop(vb, alloc, q->alloc_ctx[plane],
206 size, dma_dir, q->gfp_flags);
207 if (IS_ERR_OR_NULL(mem_priv))
208 goto free;
209
210 /* Associate allocator private data with this plane */
211 vb->planes[plane].mem_priv = mem_priv;
212 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
213 }
214
215 return 0;
216 free:
217 /* Free already allocated memory if one of the allocations failed */
218 for (; plane > 0; --plane) {
219 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
220 vb->planes[plane - 1].mem_priv = NULL;
221 }
222
223 return -ENOMEM;
224 }
225
226 /**
227 * __vb2_buf_mem_free() - free memory of the given buffer
228 */
229 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
230 {
231 unsigned int plane;
232
233 for (plane = 0; plane < vb->num_planes; ++plane) {
234 call_void_memop(vb, put, vb->planes[plane].mem_priv);
235 vb->planes[plane].mem_priv = NULL;
236 dprintk(3, "freed plane %d of buffer %d\n", plane,
237 vb->v4l2_buf.index);
238 }
239 }
240
241 /**
242 * __vb2_buf_userptr_put() - release userspace memory associated with
243 * a USERPTR buffer
244 */
245 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
246 {
247 unsigned int plane;
248
249 for (plane = 0; plane < vb->num_planes; ++plane) {
250 if (vb->planes[plane].mem_priv)
251 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
252 vb->planes[plane].mem_priv = NULL;
253 }
254 }
255
256 /**
257 * __vb2_plane_dmabuf_put() - release memory associated with
258 * a DMABUF shared plane
259 */
260 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
261 {
262 if (!p->mem_priv)
263 return;
264
265 if (p->dbuf_mapped)
266 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
267
268 call_void_memop(vb, detach_dmabuf, p->mem_priv);
269 dma_buf_put(p->dbuf);
270 memset(p, 0, sizeof(*p));
271 }
272
273 /**
274 * __vb2_buf_dmabuf_put() - release memory associated with
275 * a DMABUF shared buffer
276 */
277 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
278 {
279 unsigned int plane;
280
281 for (plane = 0; plane < vb->num_planes; ++plane)
282 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
283 }
284
285 /**
286 * __setup_lengths() - setup initial lengths for every plane in
287 * every buffer on the queue
288 */
289 static void __setup_lengths(struct vb2_queue *q, unsigned int n)
290 {
291 unsigned int buffer, plane;
292 struct vb2_buffer *vb;
293
294 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
295 vb = q->bufs[buffer];
296 if (!vb)
297 continue;
298
299 for (plane = 0; plane < vb->num_planes; ++plane)
300 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
301 }
302 }
303
304 /**
305 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
306 * every buffer on the queue
307 */
308 static void __setup_offsets(struct vb2_queue *q, unsigned int n)
309 {
310 unsigned int buffer, plane;
311 struct vb2_buffer *vb;
312 unsigned long off;
313
314 if (q->num_buffers) {
315 struct v4l2_plane *p;
316 vb = q->bufs[q->num_buffers - 1];
317 p = &vb->v4l2_planes[vb->num_planes - 1];
318 off = PAGE_ALIGN(p->m.mem_offset + p->length);
319 } else {
320 off = 0;
321 }
322
323 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
324 vb = q->bufs[buffer];
325 if (!vb)
326 continue;
327
328 for (plane = 0; plane < vb->num_planes; ++plane) {
329 vb->v4l2_planes[plane].m.mem_offset = off;
330
331 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
332 buffer, plane, off);
333
334 off += vb->v4l2_planes[plane].length;
335 off = PAGE_ALIGN(off);
336 }
337 }
338 }
339
340 /**
341 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
342 * video buffer memory for all buffers/planes on the queue and initializes the
343 * queue
344 *
345 * Returns the number of buffers successfully allocated.
346 */
347 static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
348 unsigned int num_buffers, unsigned int num_planes)
349 {
350 unsigned int buffer;
351 struct vb2_buffer *vb;
352 int ret;
353
354 for (buffer = 0; buffer < num_buffers; ++buffer) {
355 /* Allocate videobuf buffer structures */
356 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
357 if (!vb) {
358 dprintk(1, "memory alloc for buffer struct failed\n");
359 break;
360 }
361
362 /* Length stores number of planes for multiplanar buffers */
363 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
364 vb->v4l2_buf.length = num_planes;
365
366 vb->state = VB2_BUF_STATE_DEQUEUED;
367 vb->vb2_queue = q;
368 vb->num_planes = num_planes;
369 vb->v4l2_buf.index = q->num_buffers + buffer;
370 vb->v4l2_buf.type = q->type;
371 vb->v4l2_buf.memory = memory;
372
373 /* Allocate video buffer memory for the MMAP type */
374 if (memory == V4L2_MEMORY_MMAP) {
375 ret = __vb2_buf_mem_alloc(vb);
376 if (ret) {
377 dprintk(1, "failed allocating memory for "
378 "buffer %d\n", buffer);
379 kfree(vb);
380 break;
381 }
382 /*
383 * Call the driver-provided buffer initialization
384 * callback, if given. An error in initialization
385 * results in queue setup failure.
386 */
387 ret = call_vb_qop(vb, buf_init, vb);
388 if (ret) {
389 dprintk(1, "buffer %d %p initialization"
390 " failed\n", buffer, vb);
391 __vb2_buf_mem_free(vb);
392 kfree(vb);
393 break;
394 }
395 }
396
397 q->bufs[q->num_buffers + buffer] = vb;
398 }
399
400 __setup_lengths(q, buffer);
401 if (memory == V4L2_MEMORY_MMAP)
402 __setup_offsets(q, buffer);
403
404 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
405 buffer, num_planes);
406
407 return buffer;
408 }
409
410 /**
411 * __vb2_free_mem() - release all video buffer memory for a given queue
412 */
413 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
414 {
415 unsigned int buffer;
416 struct vb2_buffer *vb;
417
418 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
419 ++buffer) {
420 vb = q->bufs[buffer];
421 if (!vb)
422 continue;
423
424 /* Free MMAP buffers or release USERPTR buffers */
425 if (q->memory == V4L2_MEMORY_MMAP)
426 __vb2_buf_mem_free(vb);
427 else if (q->memory == V4L2_MEMORY_DMABUF)
428 __vb2_buf_dmabuf_put(vb);
429 else
430 __vb2_buf_userptr_put(vb);
431 }
432 }
433
434 /**
435 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
436 * related information, if no buffers are left return the queue to an
437 * uninitialized state. Might be called even if the queue has already been freed.
438 */
439 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
440 {
441 unsigned int buffer;
442
443 /*
444 * Sanity check: when preparing a buffer the queue lock is released for
445 * a short while (see __buf_prepare for the details), which would allow
446 * a race with a reqbufs which can call this function. Removing the
447 * buffers from underneath __buf_prepare is obviously a bad idea, so we
448 * check if any of the buffers is in the state PREPARING, and if so we
449 * just return -EAGAIN.
450 */
451 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
452 ++buffer) {
453 if (q->bufs[buffer] == NULL)
454 continue;
455 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
456 dprintk(1, "preparing buffers, cannot free\n");
457 return -EAGAIN;
458 }
459 }
460
461 /* Call driver-provided cleanup function for each buffer, if provided */
462 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
463 ++buffer) {
464 struct vb2_buffer *vb = q->bufs[buffer];
465
466 if (vb && vb->planes[0].mem_priv)
467 call_void_vb_qop(vb, buf_cleanup, vb);
468 }
469
470 /* Release video buffer memory */
471 __vb2_free_mem(q, buffers);
472
473 #ifdef CONFIG_VIDEO_ADV_DEBUG
474 /*
475 * Check that all the calls were balances during the life-time of this
476 * queue. If not (or if the debug level is 1 or up), then dump the
477 * counters to the kernel log.
478 */
479 if (q->num_buffers) {
480 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
481 q->cnt_wait_prepare != q->cnt_wait_finish;
482
483 if (unbalanced || debug) {
484 pr_info("vb2: counters for queue %p:%s\n", q,
485 unbalanced ? " UNBALANCED!" : "");
486 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
487 q->cnt_queue_setup, q->cnt_start_streaming,
488 q->cnt_stop_streaming);
489 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
490 q->cnt_wait_prepare, q->cnt_wait_finish);
491 }
492 q->cnt_queue_setup = 0;
493 q->cnt_wait_prepare = 0;
494 q->cnt_wait_finish = 0;
495 q->cnt_start_streaming = 0;
496 q->cnt_stop_streaming = 0;
497 }
498 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
499 struct vb2_buffer *vb = q->bufs[buffer];
500 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
501 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
502 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
503 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
504 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
505 vb->cnt_buf_queue != vb->cnt_buf_done ||
506 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
507 vb->cnt_buf_init != vb->cnt_buf_cleanup;
508
509 if (unbalanced || debug) {
510 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
511 q, buffer, unbalanced ? " UNBALANCED!" : "");
512 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
513 vb->cnt_buf_init, vb->cnt_buf_cleanup,
514 vb->cnt_buf_prepare, vb->cnt_buf_finish);
515 pr_info("vb2: buf_queue: %u buf_done: %u\n",
516 vb->cnt_buf_queue, vb->cnt_buf_done);
517 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
518 vb->cnt_mem_alloc, vb->cnt_mem_put,
519 vb->cnt_mem_prepare, vb->cnt_mem_finish,
520 vb->cnt_mem_mmap);
521 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
522 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
523 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
524 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
525 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
526 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
527 vb->cnt_mem_get_dmabuf,
528 vb->cnt_mem_num_users,
529 vb->cnt_mem_vaddr,
530 vb->cnt_mem_cookie);
531 }
532 }
533 #endif
534
535 /* Free videobuf buffers */
536 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
537 ++buffer) {
538 kfree(q->bufs[buffer]);
539 q->bufs[buffer] = NULL;
540 }
541
542 q->num_buffers -= buffers;
543 if (!q->num_buffers) {
544 q->memory = 0;
545 INIT_LIST_HEAD(&q->queued_list);
546 }
547 return 0;
548 }
549
550 /**
551 * __verify_planes_array() - verify that the planes array passed in struct
552 * v4l2_buffer from userspace can be safely used
553 */
554 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
555 {
556 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
557 return 0;
558
559 /* Is memory for copying plane information present? */
560 if (NULL == b->m.planes) {
561 dprintk(1, "multi-planar buffer passed but "
562 "planes array not provided\n");
563 return -EINVAL;
564 }
565
566 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
567 dprintk(1, "incorrect planes array length, "
568 "expected %d, got %d\n", vb->num_planes, b->length);
569 return -EINVAL;
570 }
571
572 return 0;
573 }
574
575 /**
576 * __verify_length() - Verify that the bytesused value for each plane fits in
577 * the plane length and that the data offset doesn't exceed the bytesused value.
578 */
579 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
580 {
581 unsigned int length;
582 unsigned int bytesused;
583 unsigned int plane;
584
585 if (!V4L2_TYPE_IS_OUTPUT(b->type))
586 return 0;
587
588 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
589 for (plane = 0; plane < vb->num_planes; ++plane) {
590 length = (b->memory == V4L2_MEMORY_USERPTR ||
591 b->memory == V4L2_MEMORY_DMABUF)
592 ? b->m.planes[plane].length
593 : vb->v4l2_planes[plane].length;
594 bytesused = b->m.planes[plane].bytesused
595 ? b->m.planes[plane].bytesused : length;
596
597 if (b->m.planes[plane].bytesused > length)
598 return -EINVAL;
599
600 if (b->m.planes[plane].data_offset > 0 &&
601 b->m.planes[plane].data_offset >= bytesused)
602 return -EINVAL;
603 }
604 } else {
605 length = (b->memory == V4L2_MEMORY_USERPTR)
606 ? b->length : vb->v4l2_planes[0].length;
607 bytesused = b->bytesused ? b->bytesused : length;
608
609 if (b->bytesused > length)
610 return -EINVAL;
611 }
612
613 return 0;
614 }
615
616 /**
617 * __buffer_in_use() - return true if the buffer is in use and
618 * the queue cannot be freed (by the means of REQBUFS(0)) call
619 */
620 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
621 {
622 unsigned int plane;
623 for (plane = 0; plane < vb->num_planes; ++plane) {
624 void *mem_priv = vb->planes[plane].mem_priv;
625 /*
626 * If num_users() has not been provided, call_memop
627 * will return 0, apparently nobody cares about this
628 * case anyway. If num_users() returns more than 1,
629 * we are not the only user of the plane's memory.
630 */
631 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
632 return true;
633 }
634 return false;
635 }
636
637 /**
638 * __buffers_in_use() - return true if any buffers on the queue are in use and
639 * the queue cannot be freed (by the means of REQBUFS(0)) call
640 */
641 static bool __buffers_in_use(struct vb2_queue *q)
642 {
643 unsigned int buffer;
644 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
645 if (__buffer_in_use(q, q->bufs[buffer]))
646 return true;
647 }
648 return false;
649 }
650
651 /**
652 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
653 * returned to userspace
654 */
655 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
656 {
657 struct vb2_queue *q = vb->vb2_queue;
658
659 /* Copy back data such as timestamp, flags, etc. */
660 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
661 b->reserved2 = vb->v4l2_buf.reserved2;
662 b->reserved = vb->v4l2_buf.reserved;
663
664 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
665 /*
666 * Fill in plane-related data if userspace provided an array
667 * for it. The caller has already verified memory and size.
668 */
669 b->length = vb->num_planes;
670 memcpy(b->m.planes, vb->v4l2_planes,
671 b->length * sizeof(struct v4l2_plane));
672 } else {
673 /*
674 * We use length and offset in v4l2_planes array even for
675 * single-planar buffers, but userspace does not.
676 */
677 b->length = vb->v4l2_planes[0].length;
678 b->bytesused = vb->v4l2_planes[0].bytesused;
679 if (q->memory == V4L2_MEMORY_MMAP)
680 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
681 else if (q->memory == V4L2_MEMORY_USERPTR)
682 b->m.userptr = vb->v4l2_planes[0].m.userptr;
683 else if (q->memory == V4L2_MEMORY_DMABUF)
684 b->m.fd = vb->v4l2_planes[0].m.fd;
685 }
686
687 /*
688 * Clear any buffer state related flags.
689 */
690 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
691 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
692 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
693 V4L2_BUF_FLAG_TIMESTAMP_COPY) {
694 /*
695 * For non-COPY timestamps, drop timestamp source bits
696 * and obtain the timestamp source from the queue.
697 */
698 b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
699 b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
700 }
701
702 switch (vb->state) {
703 case VB2_BUF_STATE_QUEUED:
704 case VB2_BUF_STATE_ACTIVE:
705 b->flags |= V4L2_BUF_FLAG_QUEUED;
706 break;
707 case VB2_BUF_STATE_ERROR:
708 b->flags |= V4L2_BUF_FLAG_ERROR;
709 /* fall through */
710 case VB2_BUF_STATE_DONE:
711 b->flags |= V4L2_BUF_FLAG_DONE;
712 break;
713 case VB2_BUF_STATE_PREPARED:
714 b->flags |= V4L2_BUF_FLAG_PREPARED;
715 break;
716 case VB2_BUF_STATE_PREPARING:
717 case VB2_BUF_STATE_DEQUEUED:
718 /* nothing */
719 break;
720 }
721
722 if (__buffer_in_use(q, vb))
723 b->flags |= V4L2_BUF_FLAG_MAPPED;
724 }
725
726 /**
727 * vb2_querybuf() - query video buffer information
728 * @q: videobuf queue
729 * @b: buffer struct passed from userspace to vidioc_querybuf handler
730 * in driver
731 *
732 * Should be called from vidioc_querybuf ioctl handler in driver.
733 * This function will verify the passed v4l2_buffer structure and fill the
734 * relevant information for the userspace.
735 *
736 * The return values from this function are intended to be directly returned
737 * from vidioc_querybuf handler in driver.
738 */
739 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
740 {
741 struct vb2_buffer *vb;
742 int ret;
743
744 if (b->type != q->type) {
745 dprintk(1, "wrong buffer type\n");
746 return -EINVAL;
747 }
748
749 if (b->index >= q->num_buffers) {
750 dprintk(1, "buffer index out of range\n");
751 return -EINVAL;
752 }
753 vb = q->bufs[b->index];
754 ret = __verify_planes_array(vb, b);
755 if (!ret)
756 __fill_v4l2_buffer(vb, b);
757 return ret;
758 }
759 EXPORT_SYMBOL(vb2_querybuf);
760
761 /**
762 * __verify_userptr_ops() - verify that all memory operations required for
763 * USERPTR queue type have been provided
764 */
765 static int __verify_userptr_ops(struct vb2_queue *q)
766 {
767 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
768 !q->mem_ops->put_userptr)
769 return -EINVAL;
770
771 return 0;
772 }
773
774 /**
775 * __verify_mmap_ops() - verify that all memory operations required for
776 * MMAP queue type have been provided
777 */
778 static int __verify_mmap_ops(struct vb2_queue *q)
779 {
780 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
781 !q->mem_ops->put || !q->mem_ops->mmap)
782 return -EINVAL;
783
784 return 0;
785 }
786
787 /**
788 * __verify_dmabuf_ops() - verify that all memory operations required for
789 * DMABUF queue type have been provided
790 */
791 static int __verify_dmabuf_ops(struct vb2_queue *q)
792 {
793 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
794 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
795 !q->mem_ops->unmap_dmabuf)
796 return -EINVAL;
797
798 return 0;
799 }
800
801 /**
802 * __verify_memory_type() - Check whether the memory type and buffer type
803 * passed to a buffer operation are compatible with the queue.
804 */
805 static int __verify_memory_type(struct vb2_queue *q,
806 enum v4l2_memory memory, enum v4l2_buf_type type)
807 {
808 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
809 memory != V4L2_MEMORY_DMABUF) {
810 dprintk(1, "unsupported memory type\n");
811 return -EINVAL;
812 }
813
814 if (type != q->type) {
815 dprintk(1, "requested type is incorrect\n");
816 return -EINVAL;
817 }
818
819 /*
820 * Make sure all the required memory ops for given memory type
821 * are available.
822 */
823 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
824 dprintk(1, "MMAP for current setup unsupported\n");
825 return -EINVAL;
826 }
827
828 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
829 dprintk(1, "USERPTR for current setup unsupported\n");
830 return -EINVAL;
831 }
832
833 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
834 dprintk(1, "DMABUF for current setup unsupported\n");
835 return -EINVAL;
836 }
837
838 /*
839 * Place the busy tests at the end: -EBUSY can be ignored when
840 * create_bufs is called with count == 0, but count == 0 should still
841 * do the memory and type validation.
842 */
843 if (vb2_fileio_is_active(q)) {
844 dprintk(1, "file io in progress\n");
845 return -EBUSY;
846 }
847 return 0;
848 }
849
850 /**
851 * __reqbufs() - Initiate streaming
852 * @q: videobuf2 queue
853 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
854 *
855 * Should be called from vidioc_reqbufs ioctl handler of a driver.
856 * This function:
857 * 1) verifies streaming parameters passed from the userspace,
858 * 2) sets up the queue,
859 * 3) negotiates number of buffers and planes per buffer with the driver
860 * to be used during streaming,
861 * 4) allocates internal buffer structures (struct vb2_buffer), according to
862 * the agreed parameters,
863 * 5) for MMAP memory type, allocates actual video memory, using the
864 * memory handling/allocation routines provided during queue initialization
865 *
866 * If req->count is 0, all the memory will be freed instead.
867 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
868 * and the queue is not busy, memory will be reallocated.
869 *
870 * The return values from this function are intended to be directly returned
871 * from vidioc_reqbufs handler in driver.
872 */
873 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
874 {
875 unsigned int num_buffers, allocated_buffers, num_planes = 0;
876 int ret;
877
878 if (q->streaming) {
879 dprintk(1, "streaming active\n");
880 return -EBUSY;
881 }
882
883 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
884 /*
885 * We already have buffers allocated, so first check if they
886 * are not in use and can be freed.
887 */
888 mutex_lock(&q->mmap_lock);
889 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
890 mutex_unlock(&q->mmap_lock);
891 dprintk(1, "memory in use, cannot free\n");
892 return -EBUSY;
893 }
894
895 /*
896 * Call queue_cancel to clean up any buffers in the PREPARED or
897 * QUEUED state which is possible if buffers were prepared or
898 * queued without ever calling STREAMON.
899 */
900 __vb2_queue_cancel(q);
901 ret = __vb2_queue_free(q, q->num_buffers);
902 mutex_unlock(&q->mmap_lock);
903 if (ret)
904 return ret;
905
906 /*
907 * In case of REQBUFS(0) return immediately without calling
908 * driver's queue_setup() callback and allocating resources.
909 */
910 if (req->count == 0)
911 return 0;
912 }
913
914 /*
915 * Make sure the requested values and current defaults are sane.
916 */
917 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
918 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
919 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
920 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
921 q->memory = req->memory;
922
923 /*
924 * Ask the driver how many buffers and planes per buffer it requires.
925 * Driver also sets the size and allocator context for each plane.
926 */
927 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
928 q->plane_sizes, q->alloc_ctx);
929 if (ret)
930 return ret;
931
932 /* Finally, allocate buffers and video memory */
933 allocated_buffers = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
934 if (allocated_buffers == 0) {
935 dprintk(1, "memory allocation failed\n");
936 return -ENOMEM;
937 }
938
939 /*
940 * There is no point in continuing if we can't allocate the minimum
941 * number of buffers needed by this vb2_queue.
942 */
943 if (allocated_buffers < q->min_buffers_needed)
944 ret = -ENOMEM;
945
946 /*
947 * Check if driver can handle the allocated number of buffers.
948 */
949 if (!ret && allocated_buffers < num_buffers) {
950 num_buffers = allocated_buffers;
951
952 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
953 &num_planes, q->plane_sizes, q->alloc_ctx);
954
955 if (!ret && allocated_buffers < num_buffers)
956 ret = -ENOMEM;
957
958 /*
959 * Either the driver has accepted a smaller number of buffers,
960 * or .queue_setup() returned an error
961 */
962 }
963
964 mutex_lock(&q->mmap_lock);
965 q->num_buffers = allocated_buffers;
966
967 if (ret < 0) {
968 /*
969 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
970 * from q->num_buffers.
971 */
972 __vb2_queue_free(q, allocated_buffers);
973 mutex_unlock(&q->mmap_lock);
974 return ret;
975 }
976 mutex_unlock(&q->mmap_lock);
977
978 /*
979 * Return the number of successfully allocated buffers
980 * to the userspace.
981 */
982 req->count = allocated_buffers;
983 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
984
985 return 0;
986 }
987
988 /**
989 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
990 * type values.
991 * @q: videobuf2 queue
992 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
993 */
994 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
995 {
996 int ret = __verify_memory_type(q, req->memory, req->type);
997
998 return ret ? ret : __reqbufs(q, req);
999 }
1000 EXPORT_SYMBOL_GPL(vb2_reqbufs);
1001
1002 /**
1003 * __create_bufs() - Allocate buffers and any required auxiliary structs
1004 * @q: videobuf2 queue
1005 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1006 * handler in driver
1007 *
1008 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1009 * This function:
1010 * 1) verifies parameter sanity
1011 * 2) calls the .queue_setup() queue operation
1012 * 3) performs any necessary memory allocations
1013 *
1014 * The return values from this function are intended to be directly returned
1015 * from vidioc_create_bufs handler in driver.
1016 */
1017 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1018 {
1019 unsigned int num_planes = 0, num_buffers, allocated_buffers;
1020 int ret;
1021
1022 if (q->num_buffers == VIDEO_MAX_FRAME) {
1023 dprintk(1, "maximum number of buffers already allocated\n");
1024 return -ENOBUFS;
1025 }
1026
1027 if (!q->num_buffers) {
1028 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
1029 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
1030 q->memory = create->memory;
1031 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
1032 }
1033
1034 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
1035
1036 /*
1037 * Ask the driver, whether the requested number of buffers, planes per
1038 * buffer and their sizes are acceptable
1039 */
1040 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1041 &num_planes, q->plane_sizes, q->alloc_ctx);
1042 if (ret)
1043 return ret;
1044
1045 /* Finally, allocate buffers and video memory */
1046 allocated_buffers = __vb2_queue_alloc(q, create->memory, num_buffers,
1047 num_planes);
1048 if (allocated_buffers == 0) {
1049 dprintk(1, "memory allocation failed\n");
1050 return -ENOMEM;
1051 }
1052
1053 /*
1054 * Check if driver can handle the so far allocated number of buffers.
1055 */
1056 if (allocated_buffers < num_buffers) {
1057 num_buffers = allocated_buffers;
1058
1059 /*
1060 * q->num_buffers contains the total number of buffers, that the
1061 * queue driver has set up
1062 */
1063 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
1064 &num_planes, q->plane_sizes, q->alloc_ctx);
1065
1066 if (!ret && allocated_buffers < num_buffers)
1067 ret = -ENOMEM;
1068
1069 /*
1070 * Either the driver has accepted a smaller number of buffers,
1071 * or .queue_setup() returned an error
1072 */
1073 }
1074
1075 mutex_lock(&q->mmap_lock);
1076 q->num_buffers += allocated_buffers;
1077
1078 if (ret < 0) {
1079 /*
1080 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1081 * from q->num_buffers.
1082 */
1083 __vb2_queue_free(q, allocated_buffers);
1084 mutex_unlock(&q->mmap_lock);
1085 return -ENOMEM;
1086 }
1087 mutex_unlock(&q->mmap_lock);
1088
1089 /*
1090 * Return the number of successfully allocated buffers
1091 * to the userspace.
1092 */
1093 create->count = allocated_buffers;
1094
1095 return 0;
1096 }
1097
1098 /**
1099 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1100 * memory and type values.
1101 * @q: videobuf2 queue
1102 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1103 * handler in driver
1104 */
1105 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
1106 {
1107 int ret = __verify_memory_type(q, create->memory, create->format.type);
1108
1109 create->index = q->num_buffers;
1110 if (create->count == 0)
1111 return ret != -EBUSY ? ret : 0;
1112 return ret ? ret : __create_bufs(q, create);
1113 }
1114 EXPORT_SYMBOL_GPL(vb2_create_bufs);
1115
1116 /**
1117 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1118 * @vb: vb2_buffer to which the plane in question belongs to
1119 * @plane_no: plane number for which the address is to be returned
1120 *
1121 * This function returns a kernel virtual address of a given plane if
1122 * such a mapping exist, NULL otherwise.
1123 */
1124 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1125 {
1126 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
1127 return NULL;
1128
1129 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
1130
1131 }
1132 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1133
1134 /**
1135 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1136 * @vb: vb2_buffer to which the plane in question belongs to
1137 * @plane_no: plane number for which the cookie is to be returned
1138 *
1139 * This function returns an allocator specific cookie for a given plane if
1140 * available, NULL otherwise. The allocator should provide some simple static
1141 * inline function, which would convert this cookie to the allocator specific
1142 * type that can be used directly by the driver to access the buffer. This can
1143 * be for example physical address, pointer to scatter list or IOMMU mapping.
1144 */
1145 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1146 {
1147 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1148 return NULL;
1149
1150 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
1151 }
1152 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1153
1154 /**
1155 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1156 * @vb: vb2_buffer returned from the driver
1157 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
1158 * VB2_BUF_STATE_ERROR if the operation finished with an error or
1159 * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
1160 * If start_streaming fails then it should return buffers with state
1161 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1162 *
1163 * This function should be called by the driver after a hardware operation on
1164 * a buffer is finished and the buffer may be returned to userspace. The driver
1165 * cannot use this buffer anymore until it is queued back to it by videobuf
1166 * by the means of buf_queue callback. Only buffers previously queued to the
1167 * driver by buf_queue can be passed to this function.
1168 *
1169 * While streaming a buffer can only be returned in state DONE or ERROR.
1170 * The start_streaming op can also return them in case the DMA engine cannot
1171 * be started for some reason. In that case the buffers should be returned with
1172 * state QUEUED.
1173 */
1174 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1175 {
1176 struct vb2_queue *q = vb->vb2_queue;
1177 unsigned long flags;
1178 unsigned int plane;
1179
1180 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1181 return;
1182
1183 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1184 state != VB2_BUF_STATE_ERROR &&
1185 state != VB2_BUF_STATE_QUEUED))
1186 state = VB2_BUF_STATE_ERROR;
1187
1188 #ifdef CONFIG_VIDEO_ADV_DEBUG
1189 /*
1190 * Although this is not a callback, it still does have to balance
1191 * with the buf_queue op. So update this counter manually.
1192 */
1193 vb->cnt_buf_done++;
1194 #endif
1195 dprintk(4, "done processing on buffer %d, state: %d\n",
1196 vb->v4l2_buf.index, state);
1197
1198 /* sync buffers */
1199 for (plane = 0; plane < vb->num_planes; ++plane)
1200 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
1201
1202 /* Add the buffer to the done buffers list */
1203 spin_lock_irqsave(&q->done_lock, flags);
1204 vb->state = state;
1205 if (state != VB2_BUF_STATE_QUEUED)
1206 list_add_tail(&vb->done_entry, &q->done_list);
1207 atomic_dec(&q->owned_by_drv_count);
1208 spin_unlock_irqrestore(&q->done_lock, flags);
1209
1210 if (state == VB2_BUF_STATE_QUEUED) {
1211 if (q->start_streaming_called)
1212 __enqueue_in_driver(vb);
1213 return;
1214 }
1215
1216 /* Inform any processes that may be waiting for buffers */
1217 wake_up(&q->done_wq);
1218 }
1219 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1220
1221 /**
1222 * vb2_discard_done() - discard all buffers marked as DONE
1223 * @q: videobuf2 queue
1224 *
1225 * This function is intended to be used with suspend/resume operations. It
1226 * discards all 'done' buffers as they would be too old to be requested after
1227 * resume.
1228 *
1229 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1230 * delayed works before calling this function to make sure no buffer will be
1231 * touched by the driver and/or hardware.
1232 */
1233 void vb2_discard_done(struct vb2_queue *q)
1234 {
1235 struct vb2_buffer *vb;
1236 unsigned long flags;
1237
1238 spin_lock_irqsave(&q->done_lock, flags);
1239 list_for_each_entry(vb, &q->done_list, done_entry)
1240 vb->state = VB2_BUF_STATE_ERROR;
1241 spin_unlock_irqrestore(&q->done_lock, flags);
1242 }
1243 EXPORT_SYMBOL_GPL(vb2_discard_done);
1244
1245 /**
1246 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1247 * v4l2_buffer by the userspace. The caller has already verified that struct
1248 * v4l2_buffer has a valid number of planes.
1249 */
1250 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
1251 struct v4l2_plane *v4l2_planes)
1252 {
1253 unsigned int plane;
1254
1255 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1256 if (WARN_ON_ONCE(b->bytesused == 0)) {
1257 pr_warn_once("use of bytesused == 0 is deprecated and will be removed in the future,\n");
1258 if (vb->vb2_queue->allow_zero_bytesused)
1259 pr_warn_once("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
1260 else
1261 pr_warn_once("use the actual size instead.\n");
1262 }
1263 }
1264
1265 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
1266 if (b->memory == V4L2_MEMORY_USERPTR) {
1267 for (plane = 0; plane < vb->num_planes; ++plane) {
1268 v4l2_planes[plane].m.userptr =
1269 b->m.planes[plane].m.userptr;
1270 v4l2_planes[plane].length =
1271 b->m.planes[plane].length;
1272 }
1273 }
1274 if (b->memory == V4L2_MEMORY_DMABUF) {
1275 for (plane = 0; plane < vb->num_planes; ++plane) {
1276 v4l2_planes[plane].m.fd =
1277 b->m.planes[plane].m.fd;
1278 v4l2_planes[plane].length =
1279 b->m.planes[plane].length;
1280 }
1281 }
1282
1283 /* Fill in driver-provided information for OUTPUT types */
1284 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1285 /*
1286 * Will have to go up to b->length when API starts
1287 * accepting variable number of planes.
1288 *
1289 * If bytesused == 0 for the output buffer, then fall
1290 * back to the full buffer size. In that case
1291 * userspace clearly never bothered to set it and
1292 * it's a safe assumption that they really meant to
1293 * use the full plane sizes.
1294 *
1295 * Some drivers, e.g. old codec drivers, use bytesused == 0
1296 * as a way to indicate that streaming is finished.
1297 * In that case, the driver should use the
1298 * allow_zero_bytesused flag to keep old userspace
1299 * applications working.
1300 */
1301 for (plane = 0; plane < vb->num_planes; ++plane) {
1302 struct v4l2_plane *pdst = &v4l2_planes[plane];
1303 struct v4l2_plane *psrc = &b->m.planes[plane];
1304
1305 if (vb->vb2_queue->allow_zero_bytesused)
1306 pdst->bytesused = psrc->bytesused;
1307 else
1308 pdst->bytesused = psrc->bytesused ?
1309 psrc->bytesused : pdst->length;
1310 pdst->data_offset = psrc->data_offset;
1311 }
1312 }
1313 } else {
1314 /*
1315 * Single-planar buffers do not use planes array,
1316 * so fill in relevant v4l2_buffer struct fields instead.
1317 * In videobuf we use our internal V4l2_planes struct for
1318 * single-planar buffers as well, for simplicity.
1319 *
1320 * If bytesused == 0 for the output buffer, then fall back
1321 * to the full buffer size as that's a sensible default.
1322 *
1323 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
1324 * a way to indicate that streaming is finished. In that case,
1325 * the driver should use the allow_zero_bytesused flag to keep
1326 * old userspace applications working.
1327 */
1328 if (b->memory == V4L2_MEMORY_USERPTR) {
1329 v4l2_planes[0].m.userptr = b->m.userptr;
1330 v4l2_planes[0].length = b->length;
1331 }
1332
1333 if (b->memory == V4L2_MEMORY_DMABUF) {
1334 v4l2_planes[0].m.fd = b->m.fd;
1335 v4l2_planes[0].length = b->length;
1336 }
1337
1338 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1339 if (vb->vb2_queue->allow_zero_bytesused)
1340 v4l2_planes[0].bytesused = b->bytesused;
1341 else
1342 v4l2_planes[0].bytesused = b->bytesused ?
1343 b->bytesused : v4l2_planes[0].length;
1344 } else
1345 v4l2_planes[0].bytesused = 0;
1346
1347 }
1348
1349 /* Zero flags that the vb2 core handles */
1350 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1351 if ((vb->vb2_queue->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
1352 V4L2_BUF_FLAG_TIMESTAMP_COPY || !V4L2_TYPE_IS_OUTPUT(b->type)) {
1353 /*
1354 * Non-COPY timestamps and non-OUTPUT queues will get
1355 * their timestamp and timestamp source flags from the
1356 * queue.
1357 */
1358 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
1359 }
1360
1361 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1362 /*
1363 * For output buffers mask out the timecode flag:
1364 * this will be handled later in vb2_internal_qbuf().
1365 * The 'field' is valid metadata for this output buffer
1366 * and so that needs to be copied here.
1367 */
1368 vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE;
1369 vb->v4l2_buf.field = b->field;
1370 } else {
1371 /* Zero any output buffer flags as this is a capture buffer */
1372 vb->v4l2_buf.flags &= ~V4L2_BUFFER_OUT_FLAGS;
1373 }
1374 }
1375
1376 /**
1377 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1378 */
1379 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1380 {
1381 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1382 return call_vb_qop(vb, buf_prepare, vb);
1383 }
1384
1385 /**
1386 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1387 */
1388 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1389 {
1390 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1391 struct vb2_queue *q = vb->vb2_queue;
1392 void *mem_priv;
1393 unsigned int plane;
1394 int ret;
1395 enum dma_data_direction dma_dir =
1396 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1397 bool reacquired = vb->planes[0].mem_priv == NULL;
1398
1399 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1400 /* Copy relevant information provided by the userspace */
1401 __fill_vb2_buffer(vb, b, planes);
1402
1403 for (plane = 0; plane < vb->num_planes; ++plane) {
1404 /* Skip the plane if already verified */
1405 if (vb->v4l2_planes[plane].m.userptr &&
1406 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1407 && vb->v4l2_planes[plane].length == planes[plane].length)
1408 continue;
1409
1410 dprintk(3, "userspace address for plane %d changed, "
1411 "reacquiring memory\n", plane);
1412
1413 /* Check if the provided plane buffer is large enough */
1414 if (planes[plane].length < q->plane_sizes[plane]) {
1415 dprintk(1, "provided buffer size %u is less than "
1416 "setup size %u for plane %d\n",
1417 planes[plane].length,
1418 q->plane_sizes[plane], plane);
1419 ret = -EINVAL;
1420 goto err;
1421 }
1422
1423 /* Release previously acquired memory if present */
1424 if (vb->planes[plane].mem_priv) {
1425 if (!reacquired) {
1426 reacquired = true;
1427 call_void_vb_qop(vb, buf_cleanup, vb);
1428 }
1429 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1430 }
1431
1432 vb->planes[plane].mem_priv = NULL;
1433 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1434
1435 /* Acquire each plane's memory */
1436 mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_ctx[plane],
1437 planes[plane].m.userptr,
1438 planes[plane].length, dma_dir);
1439 if (IS_ERR_OR_NULL(mem_priv)) {
1440 dprintk(1, "failed acquiring userspace "
1441 "memory for plane %d\n", plane);
1442 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1443 goto err;
1444 }
1445 vb->planes[plane].mem_priv = mem_priv;
1446 }
1447
1448 /*
1449 * Now that everything is in order, copy relevant information
1450 * provided by userspace.
1451 */
1452 for (plane = 0; plane < vb->num_planes; ++plane)
1453 vb->v4l2_planes[plane] = planes[plane];
1454
1455 if (reacquired) {
1456 /*
1457 * One or more planes changed, so we must call buf_init to do
1458 * the driver-specific initialization on the newly acquired
1459 * buffer, if provided.
1460 */
1461 ret = call_vb_qop(vb, buf_init, vb);
1462 if (ret) {
1463 dprintk(1, "buffer initialization failed\n");
1464 goto err;
1465 }
1466 }
1467
1468 ret = call_vb_qop(vb, buf_prepare, vb);
1469 if (ret) {
1470 dprintk(1, "buffer preparation failed\n");
1471 call_void_vb_qop(vb, buf_cleanup, vb);
1472 goto err;
1473 }
1474
1475 return 0;
1476 err:
1477 /* In case of errors, release planes that were already acquired */
1478 for (plane = 0; plane < vb->num_planes; ++plane) {
1479 if (vb->planes[plane].mem_priv)
1480 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1481 vb->planes[plane].mem_priv = NULL;
1482 vb->v4l2_planes[plane].m.userptr = 0;
1483 vb->v4l2_planes[plane].length = 0;
1484 }
1485
1486 return ret;
1487 }
1488
1489 /**
1490 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1491 */
1492 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1493 {
1494 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1495 struct vb2_queue *q = vb->vb2_queue;
1496 void *mem_priv;
1497 unsigned int plane;
1498 int ret;
1499 enum dma_data_direction dma_dir =
1500 V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
1501 bool reacquired = vb->planes[0].mem_priv == NULL;
1502
1503 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1504 /* Copy relevant information provided by the userspace */
1505 __fill_vb2_buffer(vb, b, planes);
1506
1507 for (plane = 0; plane < vb->num_planes; ++plane) {
1508 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1509
1510 if (IS_ERR_OR_NULL(dbuf)) {
1511 dprintk(1, "invalid dmabuf fd for plane %d\n",
1512 plane);
1513 ret = -EINVAL;
1514 goto err;
1515 }
1516
1517 /* use DMABUF size if length is not provided */
1518 if (planes[plane].length == 0)
1519 planes[plane].length = dbuf->size;
1520
1521 if (planes[plane].length < q->plane_sizes[plane]) {
1522 dprintk(1, "invalid dmabuf length for plane %d\n",
1523 plane);
1524 ret = -EINVAL;
1525 goto err;
1526 }
1527
1528 /* Skip the plane if already verified */
1529 if (dbuf == vb->planes[plane].dbuf &&
1530 vb->v4l2_planes[plane].length == planes[plane].length) {
1531 dma_buf_put(dbuf);
1532 continue;
1533 }
1534
1535 dprintk(1, "buffer for plane %d changed\n", plane);
1536
1537 if (!reacquired) {
1538 reacquired = true;
1539 call_void_vb_qop(vb, buf_cleanup, vb);
1540 }
1541
1542 /* Release previously acquired memory if present */
1543 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1544 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1545
1546 /* Acquire each plane's memory */
1547 mem_priv = call_ptr_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
1548 dbuf, planes[plane].length, dma_dir);
1549 if (IS_ERR(mem_priv)) {
1550 dprintk(1, "failed to attach dmabuf\n");
1551 ret = PTR_ERR(mem_priv);
1552 dma_buf_put(dbuf);
1553 goto err;
1554 }
1555
1556 vb->planes[plane].dbuf = dbuf;
1557 vb->planes[plane].mem_priv = mem_priv;
1558 }
1559
1560 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1561 * really we want to do this just before the DMA, not while queueing
1562 * the buffer(s)..
1563 */
1564 for (plane = 0; plane < vb->num_planes; ++plane) {
1565 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1566 if (ret) {
1567 dprintk(1, "failed to map dmabuf for plane %d\n",
1568 plane);
1569 goto err;
1570 }
1571 vb->planes[plane].dbuf_mapped = 1;
1572 }
1573
1574 /*
1575 * Now that everything is in order, copy relevant information
1576 * provided by userspace.
1577 */
1578 for (plane = 0; plane < vb->num_planes; ++plane)
1579 vb->v4l2_planes[plane] = planes[plane];
1580
1581 if (reacquired) {
1582 /*
1583 * Call driver-specific initialization on the newly acquired buffer,
1584 * if provided.
1585 */
1586 ret = call_vb_qop(vb, buf_init, vb);
1587 if (ret) {
1588 dprintk(1, "buffer initialization failed\n");
1589 goto err;
1590 }
1591 }
1592
1593 ret = call_vb_qop(vb, buf_prepare, vb);
1594 if (ret) {
1595 dprintk(1, "buffer preparation failed\n");
1596 call_void_vb_qop(vb, buf_cleanup, vb);
1597 goto err;
1598 }
1599
1600 return 0;
1601 err:
1602 /* In case of errors, release planes that were already acquired */
1603 __vb2_buf_dmabuf_put(vb);
1604
1605 return ret;
1606 }
1607
1608 /**
1609 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1610 */
1611 static void __enqueue_in_driver(struct vb2_buffer *vb)
1612 {
1613 struct vb2_queue *q = vb->vb2_queue;
1614 unsigned int plane;
1615
1616 vb->state = VB2_BUF_STATE_ACTIVE;
1617 atomic_inc(&q->owned_by_drv_count);
1618
1619 /* sync buffers */
1620 for (plane = 0; plane < vb->num_planes; ++plane)
1621 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1622
1623 call_void_vb_qop(vb, buf_queue, vb);
1624 }
1625
1626 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1627 {
1628 struct vb2_queue *q = vb->vb2_queue;
1629 int ret;
1630
1631 ret = __verify_length(vb, b);
1632 if (ret < 0) {
1633 dprintk(1, "plane parameters verification failed: %d\n", ret);
1634 return ret;
1635 }
1636 if (b->field == V4L2_FIELD_ALTERNATE && V4L2_TYPE_IS_OUTPUT(q->type)) {
1637 /*
1638 * If the format's field is ALTERNATE, then the buffer's field
1639 * should be either TOP or BOTTOM, not ALTERNATE since that
1640 * makes no sense. The driver has to know whether the
1641 * buffer represents a top or a bottom field in order to
1642 * program any DMA correctly. Using ALTERNATE is wrong, since
1643 * that just says that it is either a top or a bottom field,
1644 * but not which of the two it is.
1645 */
1646 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1647 return -EINVAL;
1648 }
1649
1650 if (q->error) {
1651 dprintk(1, "fatal error occurred on queue\n");
1652 return -EIO;
1653 }
1654
1655 vb->state = VB2_BUF_STATE_PREPARING;
1656 vb->v4l2_buf.timestamp.tv_sec = 0;
1657 vb->v4l2_buf.timestamp.tv_usec = 0;
1658 vb->v4l2_buf.sequence = 0;
1659
1660 switch (q->memory) {
1661 case V4L2_MEMORY_MMAP:
1662 ret = __qbuf_mmap(vb, b);
1663 break;
1664 case V4L2_MEMORY_USERPTR:
1665 down_read(&current->mm->mmap_sem);
1666 ret = __qbuf_userptr(vb, b);
1667 up_read(&current->mm->mmap_sem);
1668 break;
1669 case V4L2_MEMORY_DMABUF:
1670 ret = __qbuf_dmabuf(vb, b);
1671 break;
1672 default:
1673 WARN(1, "Invalid queue type\n");
1674 ret = -EINVAL;
1675 }
1676
1677 if (ret)
1678 dprintk(1, "buffer preparation failed: %d\n", ret);
1679 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1680
1681 return ret;
1682 }
1683
1684 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1685 const char *opname)
1686 {
1687 if (b->type != q->type) {
1688 dprintk(1, "%s: invalid buffer type\n", opname);
1689 return -EINVAL;
1690 }
1691
1692 if (b->index >= q->num_buffers) {
1693 dprintk(1, "%s: buffer index out of range\n", opname);
1694 return -EINVAL;
1695 }
1696
1697 if (q->bufs[b->index] == NULL) {
1698 /* Should never happen */
1699 dprintk(1, "%s: buffer is NULL\n", opname);
1700 return -EINVAL;
1701 }
1702
1703 if (b->memory != q->memory) {
1704 dprintk(1, "%s: invalid memory type\n", opname);
1705 return -EINVAL;
1706 }
1707
1708 return __verify_planes_array(q->bufs[b->index], b);
1709 }
1710
1711 /**
1712 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1713 * @q: videobuf2 queue
1714 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1715 * handler in driver
1716 *
1717 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1718 * This function:
1719 * 1) verifies the passed buffer,
1720 * 2) calls buf_prepare callback in the driver (if provided), in which
1721 * driver-specific buffer initialization can be performed,
1722 *
1723 * The return values from this function are intended to be directly returned
1724 * from vidioc_prepare_buf handler in driver.
1725 */
1726 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1727 {
1728 struct vb2_buffer *vb;
1729 int ret;
1730
1731 if (vb2_fileio_is_active(q)) {
1732 dprintk(1, "file io in progress\n");
1733 return -EBUSY;
1734 }
1735
1736 ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1737 if (ret)
1738 return ret;
1739
1740 vb = q->bufs[b->index];
1741 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1742 dprintk(1, "invalid buffer state %d\n",
1743 vb->state);
1744 return -EINVAL;
1745 }
1746
1747 ret = __buf_prepare(vb, b);
1748 if (!ret) {
1749 /* Fill buffer information for the userspace */
1750 __fill_v4l2_buffer(vb, b);
1751
1752 dprintk(1, "prepare of buffer %d succeeded\n", vb->v4l2_buf.index);
1753 }
1754 return ret;
1755 }
1756 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1757
1758 /**
1759 * vb2_start_streaming() - Attempt to start streaming.
1760 * @q: videobuf2 queue
1761 *
1762 * Attempt to start streaming. When this function is called there must be
1763 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1764 * number of buffers required for the DMA engine to function). If the
1765 * @start_streaming op fails it is supposed to return all the driver-owned
1766 * buffers back to vb2 in state QUEUED. Check if that happened and if
1767 * not warn and reclaim them forcefully.
1768 */
1769 static int vb2_start_streaming(struct vb2_queue *q)
1770 {
1771 struct vb2_buffer *vb;
1772 int ret;
1773
1774 /*
1775 * If any buffers were queued before streamon,
1776 * we can now pass them to driver for processing.
1777 */
1778 list_for_each_entry(vb, &q->queued_list, queued_entry)
1779 __enqueue_in_driver(vb);
1780
1781 /* Tell the driver to start streaming */
1782 q->start_streaming_called = 1;
1783 ret = call_qop(q, start_streaming, q,
1784 atomic_read(&q->owned_by_drv_count));
1785 if (!ret)
1786 return 0;
1787
1788 q->start_streaming_called = 0;
1789
1790 dprintk(1, "driver refused to start streaming\n");
1791 /*
1792 * If you see this warning, then the driver isn't cleaning up properly
1793 * after a failed start_streaming(). See the start_streaming()
1794 * documentation in videobuf2-core.h for more information how buffers
1795 * should be returned to vb2 in start_streaming().
1796 */
1797 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1798 unsigned i;
1799
1800 /*
1801 * Forcefully reclaim buffers if the driver did not
1802 * correctly return them to vb2.
1803 */
1804 for (i = 0; i < q->num_buffers; ++i) {
1805 vb = q->bufs[i];
1806 if (vb->state == VB2_BUF_STATE_ACTIVE)
1807 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1808 }
1809 /* Must be zero now */
1810 WARN_ON(atomic_read(&q->owned_by_drv_count));
1811 }
1812 /*
1813 * If done_list is not empty, then start_streaming() didn't call
1814 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1815 * STATE_DONE.
1816 */
1817 WARN_ON(!list_empty(&q->done_list));
1818 return ret;
1819 }
1820
1821 static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1822 {
1823 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1824 struct vb2_buffer *vb;
1825
1826 if (ret)
1827 return ret;
1828
1829 vb = q->bufs[b->index];
1830
1831 switch (vb->state) {
1832 case VB2_BUF_STATE_DEQUEUED:
1833 ret = __buf_prepare(vb, b);
1834 if (ret)
1835 return ret;
1836 break;
1837 case VB2_BUF_STATE_PREPARED:
1838 break;
1839 case VB2_BUF_STATE_PREPARING:
1840 dprintk(1, "buffer still being prepared\n");
1841 return -EINVAL;
1842 default:
1843 dprintk(1, "invalid buffer state %d\n", vb->state);
1844 return -EINVAL;
1845 }
1846
1847 /*
1848 * Add to the queued buffers list, a buffer will stay on it until
1849 * dequeued in dqbuf.
1850 */
1851 list_add_tail(&vb->queued_entry, &q->queued_list);
1852 q->queued_count++;
1853 q->waiting_for_buffers = false;
1854 vb->state = VB2_BUF_STATE_QUEUED;
1855 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1856 /*
1857 * For output buffers copy the timestamp if needed,
1858 * and the timecode field and flag if needed.
1859 */
1860 if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
1861 V4L2_BUF_FLAG_TIMESTAMP_COPY)
1862 vb->v4l2_buf.timestamp = b->timestamp;
1863 vb->v4l2_buf.flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
1864 if (b->flags & V4L2_BUF_FLAG_TIMECODE)
1865 vb->v4l2_buf.timecode = b->timecode;
1866 }
1867
1868 /*
1869 * If already streaming, give the buffer to driver for processing.
1870 * If not, the buffer will be given to driver on next streamon.
1871 */
1872 if (q->start_streaming_called)
1873 __enqueue_in_driver(vb);
1874
1875 /* Fill buffer information for the userspace */
1876 __fill_v4l2_buffer(vb, b);
1877
1878 /*
1879 * If streamon has been called, and we haven't yet called
1880 * start_streaming() since not enough buffers were queued, and
1881 * we now have reached the minimum number of queued buffers,
1882 * then we can finally call start_streaming().
1883 */
1884 if (q->streaming && !q->start_streaming_called &&
1885 q->queued_count >= q->min_buffers_needed) {
1886 ret = vb2_start_streaming(q);
1887 if (ret)
1888 return ret;
1889 }
1890
1891 dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
1892 return 0;
1893 }
1894
1895 /**
1896 * vb2_qbuf() - Queue a buffer from userspace
1897 * @q: videobuf2 queue
1898 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1899 * in driver
1900 *
1901 * Should be called from vidioc_qbuf ioctl handler of a driver.
1902 * This function:
1903 * 1) verifies the passed buffer,
1904 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1905 * which driver-specific buffer initialization can be performed,
1906 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1907 * callback for processing.
1908 *
1909 * The return values from this function are intended to be directly returned
1910 * from vidioc_qbuf handler in driver.
1911 */
1912 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1913 {
1914 if (vb2_fileio_is_active(q)) {
1915 dprintk(1, "file io in progress\n");
1916 return -EBUSY;
1917 }
1918
1919 return vb2_internal_qbuf(q, b);
1920 }
1921 EXPORT_SYMBOL_GPL(vb2_qbuf);
1922
1923 /**
1924 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1925 * for dequeuing
1926 *
1927 * Will sleep if required for nonblocking == false.
1928 */
1929 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1930 {
1931 /*
1932 * All operations on vb_done_list are performed under done_lock
1933 * spinlock protection. However, buffers may be removed from
1934 * it and returned to userspace only while holding both driver's
1935 * lock and the done_lock spinlock. Thus we can be sure that as
1936 * long as we hold the driver's lock, the list will remain not
1937 * empty if list_empty() check succeeds.
1938 */
1939
1940 for (;;) {
1941 int ret;
1942
1943 if (!q->streaming) {
1944 dprintk(1, "streaming off, will not wait for buffers\n");
1945 return -EINVAL;
1946 }
1947
1948 if (q->error) {
1949 dprintk(1, "Queue in error state, will not wait for buffers\n");
1950 return -EIO;
1951 }
1952
1953 if (q->last_buffer_dequeued) {
1954 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1955 return -EPIPE;
1956 }
1957
1958 if (!list_empty(&q->done_list)) {
1959 /*
1960 * Found a buffer that we were waiting for.
1961 */
1962 break;
1963 }
1964
1965 if (nonblocking) {
1966 dprintk(1, "nonblocking and no buffers to dequeue, "
1967 "will not wait\n");
1968 return -EAGAIN;
1969 }
1970
1971 /*
1972 * We are streaming and blocking, wait for another buffer to
1973 * become ready or for streamoff. Driver's lock is released to
1974 * allow streamoff or qbuf to be called while waiting.
1975 */
1976 call_void_qop(q, wait_prepare, q);
1977
1978 /*
1979 * All locks have been released, it is safe to sleep now.
1980 */
1981 dprintk(3, "will sleep waiting for buffers\n");
1982 ret = wait_event_interruptible(q->done_wq,
1983 !list_empty(&q->done_list) || !q->streaming ||
1984 q->error);
1985
1986 /*
1987 * We need to reevaluate both conditions again after reacquiring
1988 * the locks or return an error if one occurred.
1989 */
1990 call_void_qop(q, wait_finish, q);
1991 if (ret) {
1992 dprintk(1, "sleep was interrupted\n");
1993 return ret;
1994 }
1995 }
1996 return 0;
1997 }
1998
1999 /**
2000 * __vb2_get_done_vb() - get a buffer ready for dequeuing
2001 *
2002 * Will sleep if required for nonblocking == false.
2003 */
2004 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
2005 struct v4l2_buffer *b, int nonblocking)
2006 {
2007 unsigned long flags;
2008 int ret;
2009
2010 /*
2011 * Wait for at least one buffer to become available on the done_list.
2012 */
2013 ret = __vb2_wait_for_done_vb(q, nonblocking);
2014 if (ret)
2015 return ret;
2016
2017 /*
2018 * Driver's lock has been held since we last verified that done_list
2019 * is not empty, so no need for another list_empty(done_list) check.
2020 */
2021 spin_lock_irqsave(&q->done_lock, flags);
2022 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
2023 /*
2024 * Only remove the buffer from done_list if v4l2_buffer can handle all
2025 * the planes.
2026 */
2027 ret = __verify_planes_array(*vb, b);
2028 if (!ret)
2029 list_del(&(*vb)->done_entry);
2030 spin_unlock_irqrestore(&q->done_lock, flags);
2031
2032 return ret;
2033 }
2034
2035 /**
2036 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
2037 * @q: videobuf2 queue
2038 *
2039 * This function will wait until all buffers that have been given to the driver
2040 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
2041 * wait_prepare, wait_finish pair. It is intended to be called with all locks
2042 * taken, for example from stop_streaming() callback.
2043 */
2044 int vb2_wait_for_all_buffers(struct vb2_queue *q)
2045 {
2046 if (!q->streaming) {
2047 dprintk(1, "streaming off, will not wait for buffers\n");
2048 return -EINVAL;
2049 }
2050
2051 if (q->start_streaming_called)
2052 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
2053 return 0;
2054 }
2055 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
2056
2057 /**
2058 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2059 */
2060 static void __vb2_dqbuf(struct vb2_buffer *vb)
2061 {
2062 struct vb2_queue *q = vb->vb2_queue;
2063 unsigned int i;
2064
2065 /* nothing to do if the buffer is already dequeued */
2066 if (vb->state == VB2_BUF_STATE_DEQUEUED)
2067 return;
2068
2069 vb->state = VB2_BUF_STATE_DEQUEUED;
2070
2071 /* unmap DMABUF buffer */
2072 if (q->memory == V4L2_MEMORY_DMABUF)
2073 for (i = 0; i < vb->num_planes; ++i) {
2074 if (!vb->planes[i].dbuf_mapped)
2075 continue;
2076 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
2077 vb->planes[i].dbuf_mapped = 0;
2078 }
2079 }
2080
2081 static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2082 {
2083 struct vb2_buffer *vb = NULL;
2084 int ret;
2085
2086 if (b->type != q->type) {
2087 dprintk(1, "invalid buffer type\n");
2088 return -EINVAL;
2089 }
2090 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
2091 if (ret < 0)
2092 return ret;
2093
2094 switch (vb->state) {
2095 case VB2_BUF_STATE_DONE:
2096 dprintk(3, "returning done buffer\n");
2097 break;
2098 case VB2_BUF_STATE_ERROR:
2099 dprintk(3, "returning done buffer with errors\n");
2100 break;
2101 default:
2102 dprintk(1, "invalid buffer state\n");
2103 return -EINVAL;
2104 }
2105
2106 call_void_vb_qop(vb, buf_finish, vb);
2107
2108 /* Fill buffer information for the userspace */
2109 __fill_v4l2_buffer(vb, b);
2110 /* Remove from videobuf queue */
2111 list_del(&vb->queued_entry);
2112 q->queued_count--;
2113 if (!V4L2_TYPE_IS_OUTPUT(q->type) &&
2114 vb->v4l2_buf.flags & V4L2_BUF_FLAG_LAST)
2115 q->last_buffer_dequeued = true;
2116 /* go back to dequeued state */
2117 __vb2_dqbuf(vb);
2118
2119 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2120 vb->v4l2_buf.index, vb->state);
2121
2122 return 0;
2123 }
2124
2125 /**
2126 * vb2_dqbuf() - Dequeue a buffer to the userspace
2127 * @q: videobuf2 queue
2128 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2129 * in driver
2130 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2131 * buffers ready for dequeuing are present. Normally the driver
2132 * would be passing (file->f_flags & O_NONBLOCK) here
2133 *
2134 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2135 * This function:
2136 * 1) verifies the passed buffer,
2137 * 2) calls buf_finish callback in the driver (if provided), in which
2138 * driver can perform any additional operations that may be required before
2139 * returning the buffer to userspace, such as cache sync,
2140 * 3) the buffer struct members are filled with relevant information for
2141 * the userspace.
2142 *
2143 * The return values from this function are intended to be directly returned
2144 * from vidioc_dqbuf handler in driver.
2145 */
2146 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
2147 {
2148 if (vb2_fileio_is_active(q)) {
2149 dprintk(1, "file io in progress\n");
2150 return -EBUSY;
2151 }
2152 return vb2_internal_dqbuf(q, b, nonblocking);
2153 }
2154 EXPORT_SYMBOL_GPL(vb2_dqbuf);
2155
2156 /**
2157 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2158 *
2159 * Removes all queued buffers from driver's queue and all buffers queued by
2160 * userspace from videobuf's queue. Returns to state after reqbufs.
2161 */
2162 static void __vb2_queue_cancel(struct vb2_queue *q)
2163 {
2164 unsigned int i;
2165
2166 /*
2167 * Tell driver to stop all transactions and release all queued
2168 * buffers.
2169 */
2170 if (q->start_streaming_called)
2171 call_void_qop(q, stop_streaming, q);
2172
2173 /*
2174 * If you see this warning, then the driver isn't cleaning up properly
2175 * in stop_streaming(). See the stop_streaming() documentation in
2176 * videobuf2-core.h for more information how buffers should be returned
2177 * to vb2 in stop_streaming().
2178 */
2179 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2180 for (i = 0; i < q->num_buffers; ++i)
2181 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
2182 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2183 /* Must be zero now */
2184 WARN_ON(atomic_read(&q->owned_by_drv_count));
2185 }
2186
2187 q->streaming = 0;
2188 q->start_streaming_called = 0;
2189 q->queued_count = 0;
2190 q->error = 0;
2191
2192 /*
2193 * Remove all buffers from videobuf's list...
2194 */
2195 INIT_LIST_HEAD(&q->queued_list);
2196 /*
2197 * ...and done list; userspace will not receive any buffers it
2198 * has not already dequeued before initiating cancel.
2199 */
2200 INIT_LIST_HEAD(&q->done_list);
2201 atomic_set(&q->owned_by_drv_count, 0);
2202 wake_up_all(&q->done_wq);
2203
2204 /*
2205 * Reinitialize all buffers for next use.
2206 * Make sure to call buf_finish for any queued buffers. Normally
2207 * that's done in dqbuf, but that's not going to happen when we
2208 * cancel the whole queue. Note: this code belongs here, not in
2209 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2210 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2211 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2212 */
2213 for (i = 0; i < q->num_buffers; ++i) {
2214 struct vb2_buffer *vb = q->bufs[i];
2215
2216 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
2217 vb->state = VB2_BUF_STATE_PREPARED;
2218 call_void_vb_qop(vb, buf_finish, vb);
2219 }
2220 __vb2_dqbuf(vb);
2221 }
2222 }
2223
2224 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2225 {
2226 int ret;
2227
2228 if (type != q->type) {
2229 dprintk(1, "invalid stream type\n");
2230 return -EINVAL;
2231 }
2232
2233 if (q->streaming) {
2234 dprintk(3, "already streaming\n");
2235 return 0;
2236 }
2237
2238 if (!q->num_buffers) {
2239 dprintk(1, "no buffers have been allocated\n");
2240 return -EINVAL;
2241 }
2242
2243 if (q->num_buffers < q->min_buffers_needed) {
2244 dprintk(1, "need at least %u allocated buffers\n",
2245 q->min_buffers_needed);
2246 return -EINVAL;
2247 }
2248
2249 /*
2250 * Tell driver to start streaming provided sufficient buffers
2251 * are available.
2252 */
2253 if (q->queued_count >= q->min_buffers_needed) {
2254 ret = vb2_start_streaming(q);
2255 if (ret) {
2256 __vb2_queue_cancel(q);
2257 return ret;
2258 }
2259 }
2260
2261 q->streaming = 1;
2262
2263 dprintk(3, "successful\n");
2264 return 0;
2265 }
2266
2267 /**
2268 * vb2_queue_error() - signal a fatal error on the queue
2269 * @q: videobuf2 queue
2270 *
2271 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2272 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2273 * buffers will return -EIO.
2274 *
2275 * The error flag will be cleared when cancelling the queue, either from
2276 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2277 * function before starting the stream, otherwise the error flag will remain set
2278 * until the queue is released when closing the device node.
2279 */
2280 void vb2_queue_error(struct vb2_queue *q)
2281 {
2282 q->error = 1;
2283
2284 wake_up_all(&q->done_wq);
2285 }
2286 EXPORT_SYMBOL_GPL(vb2_queue_error);
2287
2288 /**
2289 * vb2_streamon - start streaming
2290 * @q: videobuf2 queue
2291 * @type: type argument passed from userspace to vidioc_streamon handler
2292 *
2293 * Should be called from vidioc_streamon handler of a driver.
2294 * This function:
2295 * 1) verifies current state
2296 * 2) passes any previously queued buffers to the driver and starts streaming
2297 *
2298 * The return values from this function are intended to be directly returned
2299 * from vidioc_streamon handler in the driver.
2300 */
2301 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
2302 {
2303 if (vb2_fileio_is_active(q)) {
2304 dprintk(1, "file io in progress\n");
2305 return -EBUSY;
2306 }
2307 return vb2_internal_streamon(q, type);
2308 }
2309 EXPORT_SYMBOL_GPL(vb2_streamon);
2310
2311 static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2312 {
2313 if (type != q->type) {
2314 dprintk(1, "invalid stream type\n");
2315 return -EINVAL;
2316 }
2317
2318 /*
2319 * Cancel will pause streaming and remove all buffers from the driver
2320 * and videobuf, effectively returning control over them to userspace.
2321 *
2322 * Note that we do this even if q->streaming == 0: if you prepare or
2323 * queue buffers, and then call streamoff without ever having called
2324 * streamon, you would still expect those buffers to be returned to
2325 * their normal dequeued state.
2326 */
2327 __vb2_queue_cancel(q);
2328 q->waiting_for_buffers = !V4L2_TYPE_IS_OUTPUT(q->type);
2329 q->last_buffer_dequeued = false;
2330
2331 dprintk(3, "successful\n");
2332 return 0;
2333 }
2334
2335 /**
2336 * vb2_streamoff - stop streaming
2337 * @q: videobuf2 queue
2338 * @type: type argument passed from userspace to vidioc_streamoff handler
2339 *
2340 * Should be called from vidioc_streamoff handler of a driver.
2341 * This function:
2342 * 1) verifies current state,
2343 * 2) stop streaming and dequeues any queued buffers, including those previously
2344 * passed to the driver (after waiting for the driver to finish).
2345 *
2346 * This call can be used for pausing playback.
2347 * The return values from this function are intended to be directly returned
2348 * from vidioc_streamoff handler in the driver
2349 */
2350 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
2351 {
2352 if (vb2_fileio_is_active(q)) {
2353 dprintk(1, "file io in progress\n");
2354 return -EBUSY;
2355 }
2356 return vb2_internal_streamoff(q, type);
2357 }
2358 EXPORT_SYMBOL_GPL(vb2_streamoff);
2359
2360 /**
2361 * __find_plane_by_offset() - find plane associated with the given offset off
2362 */
2363 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2364 unsigned int *_buffer, unsigned int *_plane)
2365 {
2366 struct vb2_buffer *vb;
2367 unsigned int buffer, plane;
2368
2369 /*
2370 * Go over all buffers and their planes, comparing the given offset
2371 * with an offset assigned to each plane. If a match is found,
2372 * return its buffer and plane numbers.
2373 */
2374 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2375 vb = q->bufs[buffer];
2376
2377 for (plane = 0; plane < vb->num_planes; ++plane) {
2378 if (vb->v4l2_planes[plane].m.mem_offset == off) {
2379 *_buffer = buffer;
2380 *_plane = plane;
2381 return 0;
2382 }
2383 }
2384 }
2385
2386 return -EINVAL;
2387 }
2388
2389 /**
2390 * vb2_expbuf() - Export a buffer as a file descriptor
2391 * @q: videobuf2 queue
2392 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2393 * handler in driver
2394 *
2395 * The return values from this function are intended to be directly returned
2396 * from vidioc_expbuf handler in driver.
2397 */
2398 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
2399 {
2400 struct vb2_buffer *vb = NULL;
2401 struct vb2_plane *vb_plane;
2402 int ret;
2403 struct dma_buf *dbuf;
2404
2405 if (q->memory != V4L2_MEMORY_MMAP) {
2406 dprintk(1, "queue is not currently set up for mmap\n");
2407 return -EINVAL;
2408 }
2409
2410 if (!q->mem_ops->get_dmabuf) {
2411 dprintk(1, "queue does not support DMA buffer exporting\n");
2412 return -EINVAL;
2413 }
2414
2415 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
2416 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2417 return -EINVAL;
2418 }
2419
2420 if (eb->type != q->type) {
2421 dprintk(1, "invalid buffer type\n");
2422 return -EINVAL;
2423 }
2424
2425 if (eb->index >= q->num_buffers) {
2426 dprintk(1, "buffer index out of range\n");
2427 return -EINVAL;
2428 }
2429
2430 vb = q->bufs[eb->index];
2431
2432 if (eb->plane >= vb->num_planes) {
2433 dprintk(1, "buffer plane out of range\n");
2434 return -EINVAL;
2435 }
2436
2437 if (vb2_fileio_is_active(q)) {
2438 dprintk(1, "expbuf: file io in progress\n");
2439 return -EBUSY;
2440 }
2441
2442 vb_plane = &vb->planes[eb->plane];
2443
2444 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
2445 if (IS_ERR_OR_NULL(dbuf)) {
2446 dprintk(1, "failed to export buffer %d, plane %d\n",
2447 eb->index, eb->plane);
2448 return -EINVAL;
2449 }
2450
2451 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
2452 if (ret < 0) {
2453 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2454 eb->index, eb->plane, ret);
2455 dma_buf_put(dbuf);
2456 return ret;
2457 }
2458
2459 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2460 eb->index, eb->plane, ret);
2461 eb->fd = ret;
2462
2463 return 0;
2464 }
2465 EXPORT_SYMBOL_GPL(vb2_expbuf);
2466
2467 /**
2468 * vb2_mmap() - map video buffers into application address space
2469 * @q: videobuf2 queue
2470 * @vma: vma passed to the mmap file operation handler in the driver
2471 *
2472 * Should be called from mmap file operation handler of a driver.
2473 * This function maps one plane of one of the available video buffers to
2474 * userspace. To map whole video memory allocated on reqbufs, this function
2475 * has to be called once per each plane per each buffer previously allocated.
2476 *
2477 * When the userspace application calls mmap, it passes to it an offset returned
2478 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2479 * a "cookie", which is then used to identify the plane to be mapped.
2480 * This function finds a plane with a matching offset and a mapping is performed
2481 * by the means of a provided memory operation.
2482 *
2483 * The return values from this function are intended to be directly returned
2484 * from the mmap handler in driver.
2485 */
2486 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2487 {
2488 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2489 struct vb2_buffer *vb;
2490 unsigned int buffer = 0, plane = 0;
2491 int ret;
2492 unsigned long length;
2493
2494 if (q->memory != V4L2_MEMORY_MMAP) {
2495 dprintk(1, "queue is not currently set up for mmap\n");
2496 return -EINVAL;
2497 }
2498
2499 /*
2500 * Check memory area access mode.
2501 */
2502 if (!(vma->vm_flags & VM_SHARED)) {
2503 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2504 return -EINVAL;
2505 }
2506 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
2507 if (!(vma->vm_flags & VM_WRITE)) {
2508 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2509 return -EINVAL;
2510 }
2511 } else {
2512 if (!(vma->vm_flags & VM_READ)) {
2513 dprintk(1, "invalid vma flags, VM_READ needed\n");
2514 return -EINVAL;
2515 }
2516 }
2517 if (vb2_fileio_is_active(q)) {
2518 dprintk(1, "mmap: file io in progress\n");
2519 return -EBUSY;
2520 }
2521
2522 /*
2523 * Find the plane corresponding to the offset passed by userspace.
2524 */
2525 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2526 if (ret)
2527 return ret;
2528
2529 vb = q->bufs[buffer];
2530
2531 /*
2532 * MMAP requires page_aligned buffers.
2533 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2534 * so, we need to do the same here.
2535 */
2536 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
2537 if (length < (vma->vm_end - vma->vm_start)) {
2538 dprintk(1,
2539 "MMAP invalid, as it would overflow buffer length\n");
2540 return -EINVAL;
2541 }
2542
2543 mutex_lock(&q->mmap_lock);
2544 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2545 mutex_unlock(&q->mmap_lock);
2546 if (ret)
2547 return ret;
2548
2549 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2550 return 0;
2551 }
2552 EXPORT_SYMBOL_GPL(vb2_mmap);
2553
2554 #ifndef CONFIG_MMU
2555 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2556 unsigned long addr,
2557 unsigned long len,
2558 unsigned long pgoff,
2559 unsigned long flags)
2560 {
2561 unsigned long off = pgoff << PAGE_SHIFT;
2562 struct vb2_buffer *vb;
2563 unsigned int buffer, plane;
2564 void *vaddr;
2565 int ret;
2566
2567 if (q->memory != V4L2_MEMORY_MMAP) {
2568 dprintk(1, "queue is not currently set up for mmap\n");
2569 return -EINVAL;
2570 }
2571
2572 /*
2573 * Find the plane corresponding to the offset passed by userspace.
2574 */
2575 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2576 if (ret)
2577 return ret;
2578
2579 vb = q->bufs[buffer];
2580
2581 vaddr = vb2_plane_vaddr(vb, plane);
2582 return vaddr ? (unsigned long)vaddr : -EINVAL;
2583 }
2584 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2585 #endif
2586
2587 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2588 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2589
2590 /**
2591 * vb2_poll() - implements poll userspace operation
2592 * @q: videobuf2 queue
2593 * @file: file argument passed to the poll file operation handler
2594 * @wait: wait argument passed to the poll file operation handler
2595 *
2596 * This function implements poll file operation handler for a driver.
2597 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2598 * be informed that the file descriptor of a video device is available for
2599 * reading.
2600 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2601 * will be reported as available for writing.
2602 *
2603 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2604 * pending events.
2605 *
2606 * The return values from this function are intended to be directly returned
2607 * from poll handler in driver.
2608 */
2609 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2610 {
2611 struct video_device *vfd = video_devdata(file);
2612 unsigned long req_events = poll_requested_events(wait);
2613 struct vb2_buffer *vb = NULL;
2614 unsigned int res = 0;
2615 unsigned long flags;
2616
2617 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2618 struct v4l2_fh *fh = file->private_data;
2619
2620 if (v4l2_event_pending(fh))
2621 res = POLLPRI;
2622 else if (req_events & POLLPRI)
2623 poll_wait(file, &fh->wait, wait);
2624 }
2625
2626 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2627 return res;
2628 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2629 return res;
2630
2631 /*
2632 * Start file I/O emulator only if streaming API has not been used yet.
2633 */
2634 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2635 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2636 (req_events & (POLLIN | POLLRDNORM))) {
2637 if (__vb2_init_fileio(q, 1))
2638 return res | POLLERR;
2639 }
2640 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2641 (req_events & (POLLOUT | POLLWRNORM))) {
2642 if (__vb2_init_fileio(q, 0))
2643 return res | POLLERR;
2644 /*
2645 * Write to OUTPUT queue can be done immediately.
2646 */
2647 return res | POLLOUT | POLLWRNORM;
2648 }
2649 }
2650
2651 /*
2652 * There is nothing to wait for if the queue isn't streaming, or if the
2653 * error flag is set.
2654 */
2655 if (!vb2_is_streaming(q) || q->error)
2656 return res | POLLERR;
2657 /*
2658 * For compatibility with vb1: if QBUF hasn't been called yet, then
2659 * return POLLERR as well. This only affects capture queues, output
2660 * queues will always initialize waiting_for_buffers to false.
2661 */
2662 if (q->waiting_for_buffers)
2663 return res | POLLERR;
2664
2665 /*
2666 * For output streams you can write as long as there are fewer buffers
2667 * queued than there are buffers available.
2668 */
2669 if (V4L2_TYPE_IS_OUTPUT(q->type) && q->queued_count < q->num_buffers)
2670 return res | POLLOUT | POLLWRNORM;
2671
2672 if (list_empty(&q->done_list)) {
2673 /*
2674 * If the last buffer was dequeued from a capture queue,
2675 * return immediately. DQBUF will return -EPIPE.
2676 */
2677 if (q->last_buffer_dequeued)
2678 return res | POLLIN | POLLRDNORM;
2679
2680 poll_wait(file, &q->done_wq, wait);
2681 }
2682
2683 /*
2684 * Take first buffer available for dequeuing.
2685 */
2686 spin_lock_irqsave(&q->done_lock, flags);
2687 if (!list_empty(&q->done_list))
2688 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2689 done_entry);
2690 spin_unlock_irqrestore(&q->done_lock, flags);
2691
2692 if (vb && (vb->state == VB2_BUF_STATE_DONE
2693 || vb->state == VB2_BUF_STATE_ERROR)) {
2694 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2695 res | POLLOUT | POLLWRNORM :
2696 res | POLLIN | POLLRDNORM;
2697 }
2698 return res;
2699 }
2700 EXPORT_SYMBOL_GPL(vb2_poll);
2701
2702 /**
2703 * vb2_queue_init() - initialize a videobuf2 queue
2704 * @q: videobuf2 queue; this structure should be allocated in driver
2705 *
2706 * The vb2_queue structure should be allocated by the driver. The driver is
2707 * responsible of clearing it's content and setting initial values for some
2708 * required entries before calling this function.
2709 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2710 * to the struct vb2_queue description in include/media/videobuf2-core.h
2711 * for more information.
2712 */
2713 int vb2_queue_init(struct vb2_queue *q)
2714 {
2715 /*
2716 * Sanity check
2717 */
2718 if (WARN_ON(!q) ||
2719 WARN_ON(!q->ops) ||
2720 WARN_ON(!q->mem_ops) ||
2721 WARN_ON(!q->type) ||
2722 WARN_ON(!q->io_modes) ||
2723 WARN_ON(!q->ops->queue_setup) ||
2724 WARN_ON(!q->ops->buf_queue) ||
2725 WARN_ON(q->timestamp_flags &
2726 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
2727 V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
2728 return -EINVAL;
2729
2730 /* Warn that the driver should choose an appropriate timestamp type */
2731 WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2732 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2733
2734 INIT_LIST_HEAD(&q->queued_list);
2735 INIT_LIST_HEAD(&q->done_list);
2736 spin_lock_init(&q->done_lock);
2737 mutex_init(&q->mmap_lock);
2738 init_waitqueue_head(&q->done_wq);
2739
2740 if (q->buf_struct_size == 0)
2741 q->buf_struct_size = sizeof(struct vb2_buffer);
2742
2743 return 0;
2744 }
2745 EXPORT_SYMBOL_GPL(vb2_queue_init);
2746
2747 /**
2748 * vb2_queue_release() - stop streaming, release the queue and free memory
2749 * @q: videobuf2 queue
2750 *
2751 * This function stops streaming and performs necessary clean ups, including
2752 * freeing video buffer memory. The driver is responsible for freeing
2753 * the vb2_queue structure itself.
2754 */
2755 void vb2_queue_release(struct vb2_queue *q)
2756 {
2757 __vb2_cleanup_fileio(q);
2758 __vb2_queue_cancel(q);
2759 mutex_lock(&q->mmap_lock);
2760 __vb2_queue_free(q, q->num_buffers);
2761 mutex_unlock(&q->mmap_lock);
2762 }
2763 EXPORT_SYMBOL_GPL(vb2_queue_release);
2764
2765 /**
2766 * struct vb2_fileio_buf - buffer context used by file io emulator
2767 *
2768 * vb2 provides a compatibility layer and emulator of file io (read and
2769 * write) calls on top of streaming API. This structure is used for
2770 * tracking context related to the buffers.
2771 */
2772 struct vb2_fileio_buf {
2773 void *vaddr;
2774 unsigned int size;
2775 unsigned int pos;
2776 unsigned int queued:1;
2777 };
2778
2779 /**
2780 * struct vb2_fileio_data - queue context used by file io emulator
2781 *
2782 * @cur_index: the index of the buffer currently being read from or
2783 * written to. If equal to q->num_buffers then a new buffer
2784 * must be dequeued.
2785 * @initial_index: in the read() case all buffers are queued up immediately
2786 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2787 * buffers. However, in the write() case no buffers are initially
2788 * queued, instead whenever a buffer is full it is queued up by
2789 * __vb2_perform_fileio(). Only once all available buffers have
2790 * been queued up will __vb2_perform_fileio() start to dequeue
2791 * buffers. This means that initially __vb2_perform_fileio()
2792 * needs to know what buffer index to use when it is queuing up
2793 * the buffers for the first time. That initial index is stored
2794 * in this field. Once it is equal to q->num_buffers all
2795 * available buffers have been queued and __vb2_perform_fileio()
2796 * should start the normal dequeue/queue cycle.
2797 *
2798 * vb2 provides a compatibility layer and emulator of file io (read and
2799 * write) calls on top of streaming API. For proper operation it required
2800 * this structure to save the driver state between each call of the read
2801 * or write function.
2802 */
2803 struct vb2_fileio_data {
2804 struct v4l2_requestbuffers req;
2805 struct v4l2_plane p;
2806 struct v4l2_buffer b;
2807 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2808 unsigned int cur_index;
2809 unsigned int initial_index;
2810 unsigned int q_count;
2811 unsigned int dq_count;
2812 unsigned read_once:1;
2813 unsigned write_immediately:1;
2814 };
2815
2816 /**
2817 * __vb2_init_fileio() - initialize file io emulator
2818 * @q: videobuf2 queue
2819 * @read: mode selector (1 means read, 0 means write)
2820 */
2821 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2822 {
2823 struct vb2_fileio_data *fileio;
2824 int i, ret;
2825 unsigned int count = 0;
2826
2827 /*
2828 * Sanity check
2829 */
2830 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2831 (!read && !(q->io_modes & VB2_WRITE))))
2832 return -EINVAL;
2833
2834 /*
2835 * Check if device supports mapping buffers to kernel virtual space.
2836 */
2837 if (!q->mem_ops->vaddr)
2838 return -EBUSY;
2839
2840 /*
2841 * Check if streaming api has not been already activated.
2842 */
2843 if (q->streaming || q->num_buffers > 0)
2844 return -EBUSY;
2845
2846 /*
2847 * Start with count 1, driver can increase it in queue_setup()
2848 */
2849 count = 1;
2850
2851 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2852 (read) ? "read" : "write", count, q->fileio_read_once,
2853 q->fileio_write_immediately);
2854
2855 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2856 if (fileio == NULL)
2857 return -ENOMEM;
2858
2859 fileio->read_once = q->fileio_read_once;
2860 fileio->write_immediately = q->fileio_write_immediately;
2861
2862 /*
2863 * Request buffers and use MMAP type to force driver
2864 * to allocate buffers by itself.
2865 */
2866 fileio->req.count = count;
2867 fileio->req.memory = V4L2_MEMORY_MMAP;
2868 fileio->req.type = q->type;
2869 q->fileio = fileio;
2870 ret = __reqbufs(q, &fileio->req);
2871 if (ret)
2872 goto err_kfree;
2873
2874 /*
2875 * Check if plane_count is correct
2876 * (multiplane buffers are not supported).
2877 */
2878 if (q->bufs[0]->num_planes != 1) {
2879 ret = -EBUSY;
2880 goto err_reqbufs;
2881 }
2882
2883 /*
2884 * Get kernel address of each buffer.
2885 */
2886 for (i = 0; i < q->num_buffers; i++) {
2887 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2888 if (fileio->bufs[i].vaddr == NULL) {
2889 ret = -EINVAL;
2890 goto err_reqbufs;
2891 }
2892 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2893 }
2894
2895 /*
2896 * Read mode requires pre queuing of all buffers.
2897 */
2898 if (read) {
2899 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2900
2901 /*
2902 * Queue all buffers.
2903 */
2904 for (i = 0; i < q->num_buffers; i++) {
2905 struct v4l2_buffer *b = &fileio->b;
2906
2907 memset(b, 0, sizeof(*b));
2908 b->type = q->type;
2909 if (is_multiplanar) {
2910 memset(&fileio->p, 0, sizeof(fileio->p));
2911 b->m.planes = &fileio->p;
2912 b->length = 1;
2913 }
2914 b->memory = q->memory;
2915 b->index = i;
2916 ret = vb2_internal_qbuf(q, b);
2917 if (ret)
2918 goto err_reqbufs;
2919 fileio->bufs[i].queued = 1;
2920 }
2921 /*
2922 * All buffers have been queued, so mark that by setting
2923 * initial_index to q->num_buffers
2924 */
2925 fileio->initial_index = q->num_buffers;
2926 fileio->cur_index = q->num_buffers;
2927 }
2928
2929 /*
2930 * Start streaming.
2931 */
2932 ret = vb2_internal_streamon(q, q->type);
2933 if (ret)
2934 goto err_reqbufs;
2935
2936 return ret;
2937
2938 err_reqbufs:
2939 fileio->req.count = 0;
2940 __reqbufs(q, &fileio->req);
2941
2942 err_kfree:
2943 q->fileio = NULL;
2944 kfree(fileio);
2945 return ret;
2946 }
2947
2948 /**
2949 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2950 * @q: videobuf2 queue
2951 */
2952 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2953 {
2954 struct vb2_fileio_data *fileio = q->fileio;
2955
2956 if (fileio) {
2957 vb2_internal_streamoff(q, q->type);
2958 q->fileio = NULL;
2959 fileio->req.count = 0;
2960 vb2_reqbufs(q, &fileio->req);
2961 kfree(fileio);
2962 dprintk(3, "file io emulator closed\n");
2963 }
2964 return 0;
2965 }
2966
2967 /**
2968 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2969 * @q: videobuf2 queue
2970 * @data: pointed to target userspace buffer
2971 * @count: number of bytes to read or write
2972 * @ppos: file handle position tracking pointer
2973 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2974 * @read: access mode selector (1 means read, 0 means write)
2975 */
2976 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2977 loff_t *ppos, int nonblock, int read)
2978 {
2979 struct vb2_fileio_data *fileio;
2980 struct vb2_fileio_buf *buf;
2981 bool is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
2982 /*
2983 * When using write() to write data to an output video node the vb2 core
2984 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2985 * else is able to provide this information with the write() operation.
2986 */
2987 bool set_timestamp = !read &&
2988 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
2989 V4L2_BUF_FLAG_TIMESTAMP_COPY;
2990 int ret, index;
2991
2992 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2993 read ? "read" : "write", (long)*ppos, count,
2994 nonblock ? "non" : "");
2995
2996 if (!data)
2997 return -EINVAL;
2998
2999 /*
3000 * Initialize emulator on first call.
3001 */
3002 if (!vb2_fileio_is_active(q)) {
3003 ret = __vb2_init_fileio(q, read);
3004 dprintk(3, "vb2_init_fileio result: %d\n", ret);
3005 if (ret)
3006 return ret;
3007 }
3008 fileio = q->fileio;
3009
3010 /*
3011 * Check if we need to dequeue the buffer.
3012 */
3013 index = fileio->cur_index;
3014 if (index >= q->num_buffers) {
3015 /*
3016 * Call vb2_dqbuf to get buffer back.
3017 */
3018 memset(&fileio->b, 0, sizeof(fileio->b));
3019 fileio->b.type = q->type;
3020 fileio->b.memory = q->memory;
3021 if (is_multiplanar) {
3022 memset(&fileio->p, 0, sizeof(fileio->p));
3023 fileio->b.m.planes = &fileio->p;
3024 fileio->b.length = 1;
3025 }
3026 ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
3027 dprintk(5, "vb2_dqbuf result: %d\n", ret);
3028 if (ret)
3029 return ret;
3030 fileio->dq_count += 1;
3031
3032 fileio->cur_index = index = fileio->b.index;
3033 buf = &fileio->bufs[index];
3034
3035 /*
3036 * Get number of bytes filled by the driver
3037 */
3038 buf->pos = 0;
3039 buf->queued = 0;
3040 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
3041 : vb2_plane_size(q->bufs[index], 0);
3042 /* Compensate for data_offset on read in the multiplanar case. */
3043 if (is_multiplanar && read &&
3044 fileio->b.m.planes[0].data_offset < buf->size) {
3045 buf->pos = fileio->b.m.planes[0].data_offset;
3046 buf->size -= buf->pos;
3047 }
3048 } else {
3049 buf = &fileio->bufs[index];
3050 }
3051
3052 /*
3053 * Limit count on last few bytes of the buffer.
3054 */
3055 if (buf->pos + count > buf->size) {
3056 count = buf->size - buf->pos;
3057 dprintk(5, "reducing read count: %zd\n", count);
3058 }
3059
3060 /*
3061 * Transfer data to userspace.
3062 */
3063 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
3064 count, index, buf->pos);
3065 if (read)
3066 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
3067 else
3068 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
3069 if (ret) {
3070 dprintk(3, "error copying data\n");
3071 return -EFAULT;
3072 }
3073
3074 /*
3075 * Update counters.
3076 */
3077 buf->pos += count;
3078 *ppos += count;
3079
3080 /*
3081 * Queue next buffer if required.
3082 */
3083 if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
3084 /*
3085 * Check if this is the last buffer to read.
3086 */
3087 if (read && fileio->read_once && fileio->dq_count == 1) {
3088 dprintk(3, "read limit reached\n");
3089 return __vb2_cleanup_fileio(q);
3090 }
3091
3092 /*
3093 * Call vb2_qbuf and give buffer to the driver.
3094 */
3095 memset(&fileio->b, 0, sizeof(fileio->b));
3096 fileio->b.type = q->type;
3097 fileio->b.memory = q->memory;
3098 fileio->b.index = index;
3099 fileio->b.bytesused = buf->pos;
3100 if (is_multiplanar) {
3101 memset(&fileio->p, 0, sizeof(fileio->p));
3102 fileio->p.bytesused = buf->pos;
3103 fileio->b.m.planes = &fileio->p;
3104 fileio->b.length = 1;
3105 }
3106 if (set_timestamp)
3107 v4l2_get_timestamp(&fileio->b.timestamp);
3108 ret = vb2_internal_qbuf(q, &fileio->b);
3109 dprintk(5, "vb2_dbuf result: %d\n", ret);
3110 if (ret)
3111 return ret;
3112
3113 /*
3114 * Buffer has been queued, update the status
3115 */
3116 buf->pos = 0;
3117 buf->queued = 1;
3118 buf->size = vb2_plane_size(q->bufs[index], 0);
3119 fileio->q_count += 1;
3120 /*
3121 * If we are queuing up buffers for the first time, then
3122 * increase initial_index by one.
3123 */
3124 if (fileio->initial_index < q->num_buffers)
3125 fileio->initial_index++;
3126 /*
3127 * The next buffer to use is either a buffer that's going to be
3128 * queued for the first time (initial_index < q->num_buffers)
3129 * or it is equal to q->num_buffers, meaning that the next
3130 * time we need to dequeue a buffer since we've now queued up
3131 * all the 'first time' buffers.
3132 */
3133 fileio->cur_index = fileio->initial_index;
3134 }
3135
3136 /*
3137 * Return proper number of bytes processed.
3138 */
3139 if (ret == 0)
3140 ret = count;
3141 return ret;
3142 }
3143
3144 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
3145 loff_t *ppos, int nonblocking)
3146 {
3147 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
3148 }
3149 EXPORT_SYMBOL_GPL(vb2_read);
3150
3151 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
3152 loff_t *ppos, int nonblocking)
3153 {
3154 return __vb2_perform_fileio(q, (char __user *) data, count,
3155 ppos, nonblocking, 0);
3156 }
3157 EXPORT_SYMBOL_GPL(vb2_write);
3158
3159 struct vb2_threadio_data {
3160 struct task_struct *thread;
3161 vb2_thread_fnc fnc;
3162 void *priv;
3163 bool stop;
3164 };
3165
3166 static int vb2_thread(void *data)
3167 {
3168 struct vb2_queue *q = data;
3169 struct vb2_threadio_data *threadio = q->threadio;
3170 struct vb2_fileio_data *fileio = q->fileio;
3171 bool set_timestamp = false;
3172 int prequeue = 0;
3173 int index = 0;
3174 int ret = 0;
3175
3176 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
3177 prequeue = q->num_buffers;
3178 set_timestamp =
3179 (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
3180 V4L2_BUF_FLAG_TIMESTAMP_COPY;
3181 }
3182
3183 set_freezable();
3184
3185 for (;;) {
3186 struct vb2_buffer *vb;
3187
3188 /*
3189 * Call vb2_dqbuf to get buffer back.
3190 */
3191 memset(&fileio->b, 0, sizeof(fileio->b));
3192 fileio->b.type = q->type;
3193 fileio->b.memory = q->memory;
3194 if (prequeue) {
3195 fileio->b.index = index++;
3196 prequeue--;
3197 } else {
3198 call_void_qop(q, wait_finish, q);
3199 if (!threadio->stop)
3200 ret = vb2_internal_dqbuf(q, &fileio->b, 0);
3201 call_void_qop(q, wait_prepare, q);
3202 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
3203 }
3204 if (ret || threadio->stop)
3205 break;
3206 try_to_freeze();
3207
3208 vb = q->bufs[fileio->b.index];
3209 if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR))
3210 if (threadio->fnc(vb, threadio->priv))
3211 break;
3212 call_void_qop(q, wait_finish, q);
3213 if (set_timestamp)
3214 v4l2_get_timestamp(&fileio->b.timestamp);
3215 if (!threadio->stop)
3216 ret = vb2_internal_qbuf(q, &fileio->b);
3217 call_void_qop(q, wait_prepare, q);
3218 if (ret || threadio->stop)
3219 break;
3220 }
3221
3222 /* Hmm, linux becomes *very* unhappy without this ... */
3223 while (!kthread_should_stop()) {
3224 set_current_state(TASK_INTERRUPTIBLE);
3225 schedule();
3226 }
3227 return 0;
3228 }
3229
3230 /*
3231 * This function should not be used for anything else but the videobuf2-dvb
3232 * support. If you think you have another good use-case for this, then please
3233 * contact the linux-media mailinglist first.
3234 */
3235 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3236 const char *thread_name)
3237 {
3238 struct vb2_threadio_data *threadio;
3239 int ret = 0;
3240
3241 if (q->threadio)
3242 return -EBUSY;
3243 if (vb2_is_busy(q))
3244 return -EBUSY;
3245 if (WARN_ON(q->fileio))
3246 return -EBUSY;
3247
3248 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3249 if (threadio == NULL)
3250 return -ENOMEM;
3251 threadio->fnc = fnc;
3252 threadio->priv = priv;
3253
3254 ret = __vb2_init_fileio(q, !V4L2_TYPE_IS_OUTPUT(q->type));
3255 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
3256 if (ret)
3257 goto nomem;
3258 q->threadio = threadio;
3259 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3260 if (IS_ERR(threadio->thread)) {
3261 ret = PTR_ERR(threadio->thread);
3262 threadio->thread = NULL;
3263 goto nothread;
3264 }
3265 return 0;
3266
3267 nothread:
3268 __vb2_cleanup_fileio(q);
3269 nomem:
3270 kfree(threadio);
3271 return ret;
3272 }
3273 EXPORT_SYMBOL_GPL(vb2_thread_start);
3274
3275 int vb2_thread_stop(struct vb2_queue *q)
3276 {
3277 struct vb2_threadio_data *threadio = q->threadio;
3278 int err;
3279
3280 if (threadio == NULL)
3281 return 0;
3282 threadio->stop = true;
3283 /* Wake up all pending sleeps in the thread */
3284 vb2_queue_error(q);
3285 err = kthread_stop(threadio->thread);
3286 __vb2_cleanup_fileio(q);
3287 threadio->thread = NULL;
3288 kfree(threadio);
3289 q->threadio = NULL;
3290 return err;
3291 }
3292 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3293
3294 /*
3295 * The following functions are not part of the vb2 core API, but are helper
3296 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3297 * and struct vb2_ops.
3298 * They contain boilerplate code that most if not all drivers have to do
3299 * and so they simplify the driver code.
3300 */
3301
3302 /* The queue is busy if there is a owner and you are not that owner. */
3303 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
3304 {
3305 return vdev->queue->owner && vdev->queue->owner != file->private_data;
3306 }
3307
3308 /* vb2 ioctl helpers */
3309
3310 int vb2_ioctl_reqbufs(struct file *file, void *priv,
3311 struct v4l2_requestbuffers *p)
3312 {
3313 struct video_device *vdev = video_devdata(file);
3314 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
3315
3316 if (res)
3317 return res;
3318 if (vb2_queue_is_busy(vdev, file))
3319 return -EBUSY;
3320 res = __reqbufs(vdev->queue, p);
3321 /* If count == 0, then the owner has released all buffers and he
3322 is no longer owner of the queue. Otherwise we have a new owner. */
3323 if (res == 0)
3324 vdev->queue->owner = p->count ? file->private_data : NULL;
3325 return res;
3326 }
3327 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
3328
3329 int vb2_ioctl_create_bufs(struct file *file, void *priv,
3330 struct v4l2_create_buffers *p)
3331 {
3332 struct video_device *vdev = video_devdata(file);
3333 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
3334
3335 p->index = vdev->queue->num_buffers;
3336 /* If count == 0, then just check if memory and type are valid.
3337 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3338 if (p->count == 0)
3339 return res != -EBUSY ? res : 0;
3340 if (res)
3341 return res;
3342 if (vb2_queue_is_busy(vdev, file))
3343 return -EBUSY;
3344 res = __create_bufs(vdev->queue, p);
3345 if (res == 0)
3346 vdev->queue->owner = file->private_data;
3347 return res;
3348 }
3349 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
3350
3351 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
3352 struct v4l2_buffer *p)
3353 {
3354 struct video_device *vdev = video_devdata(file);
3355
3356 if (vb2_queue_is_busy(vdev, file))
3357 return -EBUSY;
3358 return vb2_prepare_buf(vdev->queue, p);
3359 }
3360 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
3361
3362 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
3363 {
3364 struct video_device *vdev = video_devdata(file);
3365
3366 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3367 return vb2_querybuf(vdev->queue, p);
3368 }
3369 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
3370
3371 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3372 {
3373 struct video_device *vdev = video_devdata(file);
3374
3375 if (vb2_queue_is_busy(vdev, file))
3376 return -EBUSY;
3377 return vb2_qbuf(vdev->queue, p);
3378 }
3379 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
3380
3381 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
3382 {
3383 struct video_device *vdev = video_devdata(file);
3384
3385 if (vb2_queue_is_busy(vdev, file))
3386 return -EBUSY;
3387 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
3388 }
3389 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
3390
3391 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
3392 {
3393 struct video_device *vdev = video_devdata(file);
3394
3395 if (vb2_queue_is_busy(vdev, file))
3396 return -EBUSY;
3397 return vb2_streamon(vdev->queue, i);
3398 }
3399 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
3400
3401 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
3402 {
3403 struct video_device *vdev = video_devdata(file);
3404
3405 if (vb2_queue_is_busy(vdev, file))
3406 return -EBUSY;
3407 return vb2_streamoff(vdev->queue, i);
3408 }
3409 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
3410
3411 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
3412 {
3413 struct video_device *vdev = video_devdata(file);
3414
3415 if (vb2_queue_is_busy(vdev, file))
3416 return -EBUSY;
3417 return vb2_expbuf(vdev->queue, p);
3418 }
3419 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
3420
3421 /* v4l2_file_operations helpers */
3422
3423 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
3424 {
3425 struct video_device *vdev = video_devdata(file);
3426
3427 return vb2_mmap(vdev->queue, vma);
3428 }
3429 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
3430
3431 int _vb2_fop_release(struct file *file, struct mutex *lock)
3432 {
3433 struct video_device *vdev = video_devdata(file);
3434
3435 if (lock)
3436 mutex_lock(lock);
3437 if (file->private_data == vdev->queue->owner) {
3438 vb2_queue_release(vdev->queue);
3439 vdev->queue->owner = NULL;
3440 }
3441 if (lock)
3442 mutex_unlock(lock);
3443 return v4l2_fh_release(file);
3444 }
3445 EXPORT_SYMBOL_GPL(_vb2_fop_release);
3446
3447 int vb2_fop_release(struct file *file)
3448 {
3449 struct video_device *vdev = video_devdata(file);
3450 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3451
3452 return _vb2_fop_release(file, lock);
3453 }
3454 EXPORT_SYMBOL_GPL(vb2_fop_release);
3455
3456 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
3457 size_t count, loff_t *ppos)
3458 {
3459 struct video_device *vdev = video_devdata(file);
3460 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3461 int err = -EBUSY;
3462
3463 if (!(vdev->queue->io_modes & VB2_WRITE))
3464 return -EINVAL;
3465 if (lock && mutex_lock_interruptible(lock))
3466 return -ERESTARTSYS;
3467 if (vb2_queue_is_busy(vdev, file))
3468 goto exit;
3469 err = vb2_write(vdev->queue, buf, count, ppos,
3470 file->f_flags & O_NONBLOCK);
3471 if (vdev->queue->fileio)
3472 vdev->queue->owner = file->private_data;
3473 exit:
3474 if (lock)
3475 mutex_unlock(lock);
3476 return err;
3477 }
3478 EXPORT_SYMBOL_GPL(vb2_fop_write);
3479
3480 ssize_t vb2_fop_read(struct file *file, char __user *buf,
3481 size_t count, loff_t *ppos)
3482 {
3483 struct video_device *vdev = video_devdata(file);
3484 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
3485 int err = -EBUSY;
3486
3487 if (!(vdev->queue->io_modes & VB2_READ))
3488 return -EINVAL;
3489 if (lock && mutex_lock_interruptible(lock))
3490 return -ERESTARTSYS;
3491 if (vb2_queue_is_busy(vdev, file))
3492 goto exit;
3493 err = vb2_read(vdev->queue, buf, count, ppos,
3494 file->f_flags & O_NONBLOCK);
3495 if (vdev->queue->fileio)
3496 vdev->queue->owner = file->private_data;
3497 exit:
3498 if (lock)
3499 mutex_unlock(lock);
3500 return err;
3501 }
3502 EXPORT_SYMBOL_GPL(vb2_fop_read);
3503
3504 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
3505 {
3506 struct video_device *vdev = video_devdata(file);
3507 struct vb2_queue *q = vdev->queue;
3508 struct mutex *lock = q->lock ? q->lock : vdev->lock;
3509 unsigned res;
3510 void *fileio;
3511
3512 /*
3513 * If this helper doesn't know how to lock, then you shouldn't be using
3514 * it but you should write your own.
3515 */
3516 WARN_ON(!lock);
3517
3518 if (lock && mutex_lock_interruptible(lock))
3519 return POLLERR;
3520
3521 fileio = q->fileio;
3522
3523 res = vb2_poll(vdev->queue, file, wait);
3524
3525 /* If fileio was started, then we have a new queue owner. */
3526 if (!fileio && q->fileio)
3527 q->owner = file->private_data;
3528 if (lock)
3529 mutex_unlock(lock);
3530 return res;
3531 }
3532 EXPORT_SYMBOL_GPL(vb2_fop_poll);
3533
3534 #ifndef CONFIG_MMU
3535 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
3536 unsigned long len, unsigned long pgoff, unsigned long flags)
3537 {
3538 struct video_device *vdev = video_devdata(file);
3539
3540 return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
3541 }
3542 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
3543 #endif
3544
3545 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3546
3547 void vb2_ops_wait_prepare(struct vb2_queue *vq)
3548 {
3549 mutex_unlock(vq->lock);
3550 }
3551 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
3552
3553 void vb2_ops_wait_finish(struct vb2_queue *vq)
3554 {
3555 mutex_lock(vq->lock);
3556 }
3557 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
3558
3559 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3560 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3561 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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