1 /*
2 * videobuf2-core.c - video buffer 2 core 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19 #include <linux/err.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/poll.h>
24 #include <linux/slab.h>
25 #include <linux/sched.h>
26 #include <linux/freezer.h>
27 #include <linux/kthread.h>
28
29 #include <media/videobuf2-core.h>
30 #include <media/v4l2-mc.h>
31
32 #include <trace/events/vb2.h>
33
34 static int debug;
35 module_param(debug, int, 0644);
36
37 #define dprintk(q, level, fmt, arg...) \
38 do { \
39 if (debug >= level) \
40 pr_info("[%s] %s: " fmt, (q)->name, __func__, \
41 ## arg); \
42 } while (0)
43
44 #ifdef CONFIG_VIDEO_ADV_DEBUG
45
46 /*
47 * If advanced debugging is on, then count how often each op is called
48 * successfully, which can either be per-buffer or per-queue.
49 *
50 * This makes it easy to check that the 'init' and 'cleanup'
51 * (and variations thereof) stay balanced.
52 */
53
54 #define log_memop(vb, op) \
55 dprintk((vb)->vb2_queue, 2, "call_memop(%d, %s)%s\n", \
56 (vb)->index, #op, \
57 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
58
59 #define call_memop(vb, op, args...) \
60 ({ \
61 struct vb2_queue *_q = (vb)->vb2_queue; \
62 int err; \
63 \
64 log_memop(vb, op); \
65 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
66 if (!err) \
67 (vb)->cnt_mem_ ## op++; \
68 err; \
69 })
70
71 #define call_ptr_memop(op, vb, args...) \
72 ({ \
73 struct vb2_queue *_q = (vb)->vb2_queue; \
74 void *ptr; \
75 \
76 log_memop(vb, op); \
77 ptr = _q->mem_ops->op ? _q->mem_ops->op(vb, args) : NULL; \
78 if (!IS_ERR_OR_NULL(ptr)) \
79 (vb)->cnt_mem_ ## op++; \
80 ptr; \
81 })
82
83 #define call_void_memop(vb, op, args...) \
84 ({ \
85 struct vb2_queue *_q = (vb)->vb2_queue; \
86 \
87 log_memop(vb, op); \
88 if (_q->mem_ops->op) \
89 _q->mem_ops->op(args); \
90 (vb)->cnt_mem_ ## op++; \
91 })
92
93 #define log_qop(q, op) \
94 dprintk(q, 2, "call_qop(%s)%s\n", #op, \
95 (q)->ops->op ? "" : " (nop)")
96
97 #define call_qop(q, op, args...) \
98 ({ \
99 int err; \
100 \
101 log_qop(q, op); \
102 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
103 if (!err) \
104 (q)->cnt_ ## op++; \
105 err; \
106 })
107
108 #define call_void_qop(q, op, args...) \
109 ({ \
110 log_qop(q, op); \
111 if ((q)->ops->op) \
112 (q)->ops->op(args); \
113 (q)->cnt_ ## op++; \
114 })
115
116 #define log_vb_qop(vb, op, args...) \
117 dprintk((vb)->vb2_queue, 2, "call_vb_qop(%d, %s)%s\n", \
118 (vb)->index, #op, \
119 (vb)->vb2_queue->ops->op ? "" : " (nop)")
120
121 #define call_vb_qop(vb, op, args...) \
122 ({ \
123 int err; \
124 \
125 log_vb_qop(vb, op); \
126 err = (vb)->vb2_queue->ops->op ? \
127 (vb)->vb2_queue->ops->op(args) : 0; \
128 if (!err) \
129 (vb)->cnt_ ## op++; \
130 err; \
131 })
132
133 #define call_void_vb_qop(vb, op, args...) \
134 ({ \
135 log_vb_qop(vb, op); \
136 if ((vb)->vb2_queue->ops->op) \
137 (vb)->vb2_queue->ops->op(args); \
138 (vb)->cnt_ ## op++; \
139 })
140
141 #else
142
143 #define call_memop(vb, op, args...) \
144 ((vb)->vb2_queue->mem_ops->op ? \
145 (vb)->vb2_queue->mem_ops->op(args) : 0)
146
147 #define call_ptr_memop(op, vb, args...) \
148 ((vb)->vb2_queue->mem_ops->op ? \
149 (vb)->vb2_queue->mem_ops->op(vb, args) : NULL)
150
151 #define call_void_memop(vb, op, args...) \
152 do { \
153 if ((vb)->vb2_queue->mem_ops->op) \
154 (vb)->vb2_queue->mem_ops->op(args); \
155 } while (0)
156
157 #define call_qop(q, op, args...) \
158 ((q)->ops->op ? (q)->ops->op(args) : 0)
159
160 #define call_void_qop(q, op, args...) \
161 do { \
162 if ((q)->ops->op) \
163 (q)->ops->op(args); \
164 } while (0)
165
166 #define call_vb_qop(vb, op, args...) \
167 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
168
169 #define call_void_vb_qop(vb, op, args...) \
170 do { \
171 if ((vb)->vb2_queue->ops->op) \
172 (vb)->vb2_queue->ops->op(args); \
173 } while (0)
174
175 #endif
176
177 #define call_bufop(q, op, args...) \
178 ({ \
179 int ret = 0; \
180 if (q && q->buf_ops && q->buf_ops->op) \
181 ret = q->buf_ops->op(args); \
182 ret; \
183 })
184
185 #define call_void_bufop(q, op, args...) \
186 ({ \
187 if (q && q->buf_ops && q->buf_ops->op) \
188 q->buf_ops->op(args); \
189 })
190
191 static void __vb2_queue_cancel(struct vb2_queue *q);
192 static void __enqueue_in_driver(struct vb2_buffer *vb);
193
vb2_state_name(enum vb2_buffer_state s)194 static const char *vb2_state_name(enum vb2_buffer_state s)
195 {
196 static const char * const state_names[] = {
197 [VB2_BUF_STATE_DEQUEUED] = "dequeued",
198 [VB2_BUF_STATE_IN_REQUEST] = "in request",
199 [VB2_BUF_STATE_PREPARING] = "preparing",
200 [VB2_BUF_STATE_QUEUED] = "queued",
201 [VB2_BUF_STATE_ACTIVE] = "active",
202 [VB2_BUF_STATE_DONE] = "done",
203 [VB2_BUF_STATE_ERROR] = "error",
204 };
205
206 if ((unsigned int)(s) < ARRAY_SIZE(state_names))
207 return state_names[s];
208 return "unknown";
209 }
210
211 /*
212 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
213 */
__vb2_buf_mem_alloc(struct vb2_buffer * vb)214 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
215 {
216 struct vb2_queue *q = vb->vb2_queue;
217 void *mem_priv;
218 int plane;
219 int ret = -ENOMEM;
220
221 /*
222 * Allocate memory for all planes in this buffer
223 * NOTE: mmapped areas should be page aligned
224 */
225 for (plane = 0; plane < vb->num_planes; ++plane) {
226 /* Memops alloc requires size to be page aligned. */
227 unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
228
229 /* Did it wrap around? */
230 if (size < vb->planes[plane].length)
231 goto free;
232
233 mem_priv = call_ptr_memop(alloc,
234 vb,
235 q->alloc_devs[plane] ? : q->dev,
236 size);
237 if (IS_ERR_OR_NULL(mem_priv)) {
238 if (mem_priv)
239 ret = PTR_ERR(mem_priv);
240 goto free;
241 }
242
243 /* Associate allocator private data with this plane */
244 vb->planes[plane].mem_priv = mem_priv;
245 }
246
247 return 0;
248 free:
249 /* Free already allocated memory if one of the allocations failed */
250 for (; plane > 0; --plane) {
251 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
252 vb->planes[plane - 1].mem_priv = NULL;
253 }
254
255 return ret;
256 }
257
258 /*
259 * __vb2_buf_mem_free() - free memory of the given buffer
260 */
__vb2_buf_mem_free(struct vb2_buffer * vb)261 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
262 {
263 unsigned int plane;
264
265 for (plane = 0; plane < vb->num_planes; ++plane) {
266 call_void_memop(vb, put, vb->planes[plane].mem_priv);
267 vb->planes[plane].mem_priv = NULL;
268 dprintk(vb->vb2_queue, 3, "freed plane %d of buffer %d\n",
269 plane, vb->index);
270 }
271 }
272
273 /*
274 * __vb2_buf_userptr_put() - release userspace memory associated with
275 * a USERPTR buffer
276 */
__vb2_buf_userptr_put(struct vb2_buffer * vb)277 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
278 {
279 unsigned int plane;
280
281 for (plane = 0; plane < vb->num_planes; ++plane) {
282 if (vb->planes[plane].mem_priv)
283 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
284 vb->planes[plane].mem_priv = NULL;
285 }
286 }
287
288 /*
289 * __vb2_plane_dmabuf_put() - release memory associated with
290 * a DMABUF shared plane
291 */
__vb2_plane_dmabuf_put(struct vb2_buffer * vb,struct vb2_plane * p)292 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
293 {
294 if (!p->mem_priv)
295 return;
296
297 if (p->dbuf_mapped)
298 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
299
300 call_void_memop(vb, detach_dmabuf, p->mem_priv);
301 dma_buf_put(p->dbuf);
302 p->mem_priv = NULL;
303 p->dbuf = NULL;
304 p->dbuf_mapped = 0;
305 }
306
307 /*
308 * __vb2_buf_dmabuf_put() - release memory associated with
309 * a DMABUF shared buffer
310 */
__vb2_buf_dmabuf_put(struct vb2_buffer * vb)311 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
312 {
313 unsigned int plane;
314
315 for (plane = 0; plane < vb->num_planes; ++plane)
316 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
317 }
318
319 /*
320 * __vb2_buf_mem_prepare() - call ->prepare() on buffer's private memory
321 * to sync caches
322 */
__vb2_buf_mem_prepare(struct vb2_buffer * vb)323 static void __vb2_buf_mem_prepare(struct vb2_buffer *vb)
324 {
325 unsigned int plane;
326
327 if (vb->synced)
328 return;
329
330 vb->synced = 1;
331 for (plane = 0; plane < vb->num_planes; ++plane)
332 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
333 }
334
335 /*
336 * __vb2_buf_mem_finish() - call ->finish on buffer's private memory
337 * to sync caches
338 */
__vb2_buf_mem_finish(struct vb2_buffer * vb)339 static void __vb2_buf_mem_finish(struct vb2_buffer *vb)
340 {
341 unsigned int plane;
342
343 if (!vb->synced)
344 return;
345
346 vb->synced = 0;
347 for (plane = 0; plane < vb->num_planes; ++plane)
348 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
349 }
350
351 /*
352 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
353 * the buffer.
354 */
__setup_offsets(struct vb2_buffer * vb)355 static void __setup_offsets(struct vb2_buffer *vb)
356 {
357 struct vb2_queue *q = vb->vb2_queue;
358 unsigned int plane;
359 unsigned long off = 0;
360
361 if (vb->index) {
362 struct vb2_buffer *prev = q->bufs[vb->index - 1];
363 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
364
365 off = PAGE_ALIGN(p->m.offset + p->length);
366 }
367
368 for (plane = 0; plane < vb->num_planes; ++plane) {
369 vb->planes[plane].m.offset = off;
370
371 dprintk(q, 3, "buffer %d, plane %d offset 0x%08lx\n",
372 vb->index, plane, off);
373
374 off += vb->planes[plane].length;
375 off = PAGE_ALIGN(off);
376 }
377 }
378
init_buffer_cache_hints(struct vb2_queue * q,struct vb2_buffer * vb)379 static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
380 {
381 /*
382 * DMA exporter should take care of cache syncs, so we can avoid
383 * explicit ->prepare()/->finish() syncs. For other ->memory types
384 * we always need ->prepare() or/and ->finish() cache sync.
385 */
386 if (q->memory == VB2_MEMORY_DMABUF) {
387 vb->skip_cache_sync_on_finish = 1;
388 vb->skip_cache_sync_on_prepare = 1;
389 return;
390 }
391
392 /*
393 * ->finish() cache sync can be avoided when queue direction is
394 * TO_DEVICE.
395 */
396 if (q->dma_dir == DMA_TO_DEVICE)
397 vb->skip_cache_sync_on_finish = 1;
398 }
399
400 /*
401 * __vb2_queue_alloc() - allocate vb2 buffer structures and (for MMAP type)
402 * video buffer memory for all buffers/planes on the queue and initializes the
403 * queue
404 *
405 * Returns the number of buffers successfully allocated.
406 */
__vb2_queue_alloc(struct vb2_queue * q,enum vb2_memory memory,unsigned int num_buffers,unsigned int num_planes,const unsigned plane_sizes[VB2_MAX_PLANES])407 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
408 unsigned int num_buffers, unsigned int num_planes,
409 const unsigned plane_sizes[VB2_MAX_PLANES])
410 {
411 unsigned int buffer, plane;
412 struct vb2_buffer *vb;
413 int ret;
414
415 /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
416 num_buffers = min_t(unsigned int, num_buffers,
417 VB2_MAX_FRAME - q->num_buffers);
418
419 for (buffer = 0; buffer < num_buffers; ++buffer) {
420 /* Allocate vb2 buffer structures */
421 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
422 if (!vb) {
423 dprintk(q, 1, "memory alloc for buffer struct failed\n");
424 break;
425 }
426
427 vb->state = VB2_BUF_STATE_DEQUEUED;
428 vb->vb2_queue = q;
429 vb->num_planes = num_planes;
430 vb->index = q->num_buffers + buffer;
431 vb->type = q->type;
432 vb->memory = memory;
433 init_buffer_cache_hints(q, vb);
434 for (plane = 0; plane < num_planes; ++plane) {
435 vb->planes[plane].length = plane_sizes[plane];
436 vb->planes[plane].min_length = plane_sizes[plane];
437 }
438 call_void_bufop(q, init_buffer, vb);
439
440 q->bufs[vb->index] = vb;
441
442 /* Allocate video buffer memory for the MMAP type */
443 if (memory == VB2_MEMORY_MMAP) {
444 ret = __vb2_buf_mem_alloc(vb);
445 if (ret) {
446 dprintk(q, 1, "failed allocating memory for buffer %d\n",
447 buffer);
448 q->bufs[vb->index] = NULL;
449 kfree(vb);
450 break;
451 }
452 __setup_offsets(vb);
453 /*
454 * Call the driver-provided buffer initialization
455 * callback, if given. An error in initialization
456 * results in queue setup failure.
457 */
458 ret = call_vb_qop(vb, buf_init, vb);
459 if (ret) {
460 dprintk(q, 1, "buffer %d %p initialization failed\n",
461 buffer, vb);
462 __vb2_buf_mem_free(vb);
463 q->bufs[vb->index] = NULL;
464 kfree(vb);
465 break;
466 }
467 }
468 }
469
470 dprintk(q, 3, "allocated %d buffers, %d plane(s) each\n",
471 buffer, num_planes);
472
473 return buffer;
474 }
475
476 /*
477 * __vb2_free_mem() - release all video buffer memory for a given queue
478 */
__vb2_free_mem(struct vb2_queue * q,unsigned int buffers)479 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
480 {
481 unsigned int buffer;
482 struct vb2_buffer *vb;
483
484 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
485 ++buffer) {
486 vb = q->bufs[buffer];
487 if (!vb)
488 continue;
489
490 /* Free MMAP buffers or release USERPTR buffers */
491 if (q->memory == VB2_MEMORY_MMAP)
492 __vb2_buf_mem_free(vb);
493 else if (q->memory == VB2_MEMORY_DMABUF)
494 __vb2_buf_dmabuf_put(vb);
495 else
496 __vb2_buf_userptr_put(vb);
497 }
498 }
499
500 /*
501 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
502 * related information, if no buffers are left return the queue to an
503 * uninitialized state. Might be called even if the queue has already been freed.
504 */
__vb2_queue_free(struct vb2_queue * q,unsigned int buffers)505 static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
506 {
507 unsigned int buffer;
508
509 lockdep_assert_held(&q->mmap_lock);
510
511 /* Call driver-provided cleanup function for each buffer, if provided */
512 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
513 ++buffer) {
514 struct vb2_buffer *vb = q->bufs[buffer];
515
516 if (vb && vb->planes[0].mem_priv)
517 call_void_vb_qop(vb, buf_cleanup, vb);
518 }
519
520 /* Release video buffer memory */
521 __vb2_free_mem(q, buffers);
522
523 #ifdef CONFIG_VIDEO_ADV_DEBUG
524 /*
525 * Check that all the calls were balances during the life-time of this
526 * queue. If not (or if the debug level is 1 or up), then dump the
527 * counters to the kernel log.
528 */
529 if (q->num_buffers) {
530 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
531 q->cnt_prepare_streaming != q->cnt_unprepare_streaming ||
532 q->cnt_wait_prepare != q->cnt_wait_finish;
533
534 if (unbalanced || debug) {
535 pr_info("counters for queue %p:%s\n", q,
536 unbalanced ? " UNBALANCED!" : "");
537 pr_info(" setup: %u start_streaming: %u stop_streaming: %u\n",
538 q->cnt_queue_setup, q->cnt_start_streaming,
539 q->cnt_stop_streaming);
540 pr_info(" prepare_streaming: %u unprepare_streaming: %u\n",
541 q->cnt_prepare_streaming, q->cnt_unprepare_streaming);
542 pr_info(" wait_prepare: %u wait_finish: %u\n",
543 q->cnt_wait_prepare, q->cnt_wait_finish);
544 }
545 q->cnt_queue_setup = 0;
546 q->cnt_wait_prepare = 0;
547 q->cnt_wait_finish = 0;
548 q->cnt_prepare_streaming = 0;
549 q->cnt_start_streaming = 0;
550 q->cnt_stop_streaming = 0;
551 q->cnt_unprepare_streaming = 0;
552 }
553 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
554 struct vb2_buffer *vb = q->bufs[buffer];
555 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
556 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
557 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
558 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
559 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
560 vb->cnt_buf_queue != vb->cnt_buf_done ||
561 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
562 vb->cnt_buf_init != vb->cnt_buf_cleanup;
563
564 if (unbalanced || debug) {
565 pr_info(" counters for queue %p, buffer %d:%s\n",
566 q, buffer, unbalanced ? " UNBALANCED!" : "");
567 pr_info(" buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
568 vb->cnt_buf_init, vb->cnt_buf_cleanup,
569 vb->cnt_buf_prepare, vb->cnt_buf_finish);
570 pr_info(" buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
571 vb->cnt_buf_out_validate, vb->cnt_buf_queue,
572 vb->cnt_buf_done, vb->cnt_buf_request_complete);
573 pr_info(" alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
574 vb->cnt_mem_alloc, vb->cnt_mem_put,
575 vb->cnt_mem_prepare, vb->cnt_mem_finish,
576 vb->cnt_mem_mmap);
577 pr_info(" get_userptr: %u put_userptr: %u\n",
578 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
579 pr_info(" attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
580 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
581 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
582 pr_info(" get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
583 vb->cnt_mem_get_dmabuf,
584 vb->cnt_mem_num_users,
585 vb->cnt_mem_vaddr,
586 vb->cnt_mem_cookie);
587 }
588 }
589 #endif
590
591 /* Free vb2 buffers */
592 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
593 ++buffer) {
594 kfree(q->bufs[buffer]);
595 q->bufs[buffer] = NULL;
596 }
597
598 q->num_buffers -= buffers;
599 if (!q->num_buffers) {
600 q->memory = VB2_MEMORY_UNKNOWN;
601 INIT_LIST_HEAD(&q->queued_list);
602 }
603 }
604
vb2_buffer_in_use(struct vb2_queue * q,struct vb2_buffer * vb)605 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
606 {
607 unsigned int plane;
608 for (plane = 0; plane < vb->num_planes; ++plane) {
609 void *mem_priv = vb->planes[plane].mem_priv;
610 /*
611 * If num_users() has not been provided, call_memop
612 * will return 0, apparently nobody cares about this
613 * case anyway. If num_users() returns more than 1,
614 * we are not the only user of the plane's memory.
615 */
616 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
617 return true;
618 }
619 return false;
620 }
621 EXPORT_SYMBOL(vb2_buffer_in_use);
622
623 /*
624 * __buffers_in_use() - return true if any buffers on the queue are in use and
625 * the queue cannot be freed (by the means of REQBUFS(0)) call
626 */
__buffers_in_use(struct vb2_queue * q)627 static bool __buffers_in_use(struct vb2_queue *q)
628 {
629 unsigned int buffer;
630 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
631 if (vb2_buffer_in_use(q, q->bufs[buffer]))
632 return true;
633 }
634 return false;
635 }
636
vb2_core_querybuf(struct vb2_queue * q,unsigned int index,void * pb)637 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
638 {
639 call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
640 }
641 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
642
643 /*
644 * __verify_userptr_ops() - verify that all memory operations required for
645 * USERPTR queue type have been provided
646 */
__verify_userptr_ops(struct vb2_queue * q)647 static int __verify_userptr_ops(struct vb2_queue *q)
648 {
649 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
650 !q->mem_ops->put_userptr)
651 return -EINVAL;
652
653 return 0;
654 }
655
656 /*
657 * __verify_mmap_ops() - verify that all memory operations required for
658 * MMAP queue type have been provided
659 */
__verify_mmap_ops(struct vb2_queue * q)660 static int __verify_mmap_ops(struct vb2_queue *q)
661 {
662 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
663 !q->mem_ops->put || !q->mem_ops->mmap)
664 return -EINVAL;
665
666 return 0;
667 }
668
669 /*
670 * __verify_dmabuf_ops() - verify that all memory operations required for
671 * DMABUF queue type have been provided
672 */
__verify_dmabuf_ops(struct vb2_queue * q)673 static int __verify_dmabuf_ops(struct vb2_queue *q)
674 {
675 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
676 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
677 !q->mem_ops->unmap_dmabuf)
678 return -EINVAL;
679
680 return 0;
681 }
682
vb2_verify_memory_type(struct vb2_queue * q,enum vb2_memory memory,unsigned int type)683 int vb2_verify_memory_type(struct vb2_queue *q,
684 enum vb2_memory memory, unsigned int type)
685 {
686 if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
687 memory != VB2_MEMORY_DMABUF) {
688 dprintk(q, 1, "unsupported memory type\n");
689 return -EINVAL;
690 }
691
692 if (type != q->type) {
693 dprintk(q, 1, "requested type is incorrect\n");
694 return -EINVAL;
695 }
696
697 /*
698 * Make sure all the required memory ops for given memory type
699 * are available.
700 */
701 if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
702 dprintk(q, 1, "MMAP for current setup unsupported\n");
703 return -EINVAL;
704 }
705
706 if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
707 dprintk(q, 1, "USERPTR for current setup unsupported\n");
708 return -EINVAL;
709 }
710
711 if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
712 dprintk(q, 1, "DMABUF for current setup unsupported\n");
713 return -EINVAL;
714 }
715
716 /*
717 * Place the busy tests at the end: -EBUSY can be ignored when
718 * create_bufs is called with count == 0, but count == 0 should still
719 * do the memory and type validation.
720 */
721 if (vb2_fileio_is_active(q)) {
722 dprintk(q, 1, "file io in progress\n");
723 return -EBUSY;
724 }
725 return 0;
726 }
727 EXPORT_SYMBOL(vb2_verify_memory_type);
728
set_queue_coherency(struct vb2_queue * q,bool non_coherent_mem)729 static void set_queue_coherency(struct vb2_queue *q, bool non_coherent_mem)
730 {
731 q->non_coherent_mem = 0;
732
733 if (!vb2_queue_allows_cache_hints(q))
734 return;
735 q->non_coherent_mem = non_coherent_mem;
736 }
737
verify_coherency_flags(struct vb2_queue * q,bool non_coherent_mem)738 static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
739 {
740 if (non_coherent_mem != q->non_coherent_mem) {
741 dprintk(q, 1, "memory coherency model mismatch\n");
742 return false;
743 }
744 return true;
745 }
746
vb2_core_reqbufs(struct vb2_queue * q,enum vb2_memory memory,unsigned int flags,unsigned int * count)747 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
748 unsigned int flags, unsigned int *count)
749 {
750 unsigned int num_buffers, allocated_buffers, num_planes = 0;
751 unsigned plane_sizes[VB2_MAX_PLANES] = { };
752 bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
753 unsigned int i;
754 int ret;
755
756 if (q->streaming) {
757 dprintk(q, 1, "streaming active\n");
758 return -EBUSY;
759 }
760
761 if (q->waiting_in_dqbuf && *count) {
762 dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
763 return -EBUSY;
764 }
765
766 if (*count == 0 || q->num_buffers != 0 ||
767 (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) ||
768 !verify_coherency_flags(q, non_coherent_mem)) {
769 /*
770 * We already have buffers allocated, so first check if they
771 * are not in use and can be freed.
772 */
773 mutex_lock(&q->mmap_lock);
774 if (debug && q->memory == VB2_MEMORY_MMAP &&
775 __buffers_in_use(q))
776 dprintk(q, 1, "memory in use, orphaning buffers\n");
777
778 /*
779 * Call queue_cancel to clean up any buffers in the
780 * QUEUED state which is possible if buffers were prepared or
781 * queued without ever calling STREAMON.
782 */
783 __vb2_queue_cancel(q);
784 __vb2_queue_free(q, q->num_buffers);
785 mutex_unlock(&q->mmap_lock);
786
787 /*
788 * In case of REQBUFS(0) return immediately without calling
789 * driver's queue_setup() callback and allocating resources.
790 */
791 if (*count == 0)
792 return 0;
793 }
794
795 /*
796 * Make sure the requested values and current defaults are sane.
797 */
798 WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
799 num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
800 num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
801 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
802 /*
803 * Set this now to ensure that drivers see the correct q->memory value
804 * in the queue_setup op.
805 */
806 mutex_lock(&q->mmap_lock);
807 q->memory = memory;
808 mutex_unlock(&q->mmap_lock);
809 set_queue_coherency(q, non_coherent_mem);
810
811 /*
812 * Ask the driver how many buffers and planes per buffer it requires.
813 * Driver also sets the size and allocator context for each plane.
814 */
815 ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
816 plane_sizes, q->alloc_devs);
817 if (ret)
818 goto error;
819
820 /* Check that driver has set sane values */
821 if (WARN_ON(!num_planes)) {
822 ret = -EINVAL;
823 goto error;
824 }
825
826 for (i = 0; i < num_planes; i++)
827 if (WARN_ON(!plane_sizes[i])) {
828 ret = -EINVAL;
829 goto error;
830 }
831
832 /* Finally, allocate buffers and video memory */
833 allocated_buffers =
834 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
835 if (allocated_buffers == 0) {
836 dprintk(q, 1, "memory allocation failed\n");
837 ret = -ENOMEM;
838 goto error;
839 }
840
841 /*
842 * There is no point in continuing if we can't allocate the minimum
843 * number of buffers needed by this vb2_queue.
844 */
845 if (allocated_buffers < q->min_buffers_needed)
846 ret = -ENOMEM;
847
848 /*
849 * Check if driver can handle the allocated number of buffers.
850 */
851 if (!ret && allocated_buffers < num_buffers) {
852 num_buffers = allocated_buffers;
853 /*
854 * num_planes is set by the previous queue_setup(), but since it
855 * signals to queue_setup() whether it is called from create_bufs()
856 * vs reqbufs() we zero it here to signal that queue_setup() is
857 * called for the reqbufs() case.
858 */
859 num_planes = 0;
860
861 ret = call_qop(q, queue_setup, q, &num_buffers,
862 &num_planes, plane_sizes, q->alloc_devs);
863
864 if (!ret && allocated_buffers < num_buffers)
865 ret = -ENOMEM;
866
867 /*
868 * Either the driver has accepted a smaller number of buffers,
869 * or .queue_setup() returned an error
870 */
871 }
872
873 mutex_lock(&q->mmap_lock);
874 q->num_buffers = allocated_buffers;
875
876 if (ret < 0) {
877 /*
878 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
879 * from q->num_buffers and it will reset q->memory to
880 * VB2_MEMORY_UNKNOWN.
881 */
882 __vb2_queue_free(q, allocated_buffers);
883 mutex_unlock(&q->mmap_lock);
884 return ret;
885 }
886 mutex_unlock(&q->mmap_lock);
887
888 /*
889 * Return the number of successfully allocated buffers
890 * to the userspace.
891 */
892 *count = allocated_buffers;
893 q->waiting_for_buffers = !q->is_output;
894
895 return 0;
896
897 error:
898 mutex_lock(&q->mmap_lock);
899 q->memory = VB2_MEMORY_UNKNOWN;
900 mutex_unlock(&q->mmap_lock);
901 return ret;
902 }
903 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
904
vb2_core_create_bufs(struct vb2_queue * q,enum vb2_memory memory,unsigned int flags,unsigned int * count,unsigned int requested_planes,const unsigned int requested_sizes[])905 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
906 unsigned int flags, unsigned int *count,
907 unsigned int requested_planes,
908 const unsigned int requested_sizes[])
909 {
910 unsigned int num_planes = 0, num_buffers, allocated_buffers;
911 unsigned plane_sizes[VB2_MAX_PLANES] = { };
912 bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
913 bool no_previous_buffers = !q->num_buffers;
914 int ret;
915
916 if (q->num_buffers == VB2_MAX_FRAME) {
917 dprintk(q, 1, "maximum number of buffers already allocated\n");
918 return -ENOBUFS;
919 }
920
921 if (no_previous_buffers) {
922 if (q->waiting_in_dqbuf && *count) {
923 dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
924 return -EBUSY;
925 }
926 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
927 /*
928 * Set this now to ensure that drivers see the correct q->memory
929 * value in the queue_setup op.
930 */
931 mutex_lock(&q->mmap_lock);
932 q->memory = memory;
933 mutex_unlock(&q->mmap_lock);
934 q->waiting_for_buffers = !q->is_output;
935 set_queue_coherency(q, non_coherent_mem);
936 } else {
937 if (q->memory != memory) {
938 dprintk(q, 1, "memory model mismatch\n");
939 return -EINVAL;
940 }
941 if (!verify_coherency_flags(q, non_coherent_mem))
942 return -EINVAL;
943 }
944
945 num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
946
947 if (requested_planes && requested_sizes) {
948 num_planes = requested_planes;
949 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
950 }
951
952 /*
953 * Ask the driver, whether the requested number of buffers, planes per
954 * buffer and their sizes are acceptable
955 */
956 ret = call_qop(q, queue_setup, q, &num_buffers,
957 &num_planes, plane_sizes, q->alloc_devs);
958 if (ret)
959 goto error;
960
961 /* Finally, allocate buffers and video memory */
962 allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
963 num_planes, plane_sizes);
964 if (allocated_buffers == 0) {
965 dprintk(q, 1, "memory allocation failed\n");
966 ret = -ENOMEM;
967 goto error;
968 }
969
970 /*
971 * Check if driver can handle the so far allocated number of buffers.
972 */
973 if (allocated_buffers < num_buffers) {
974 num_buffers = allocated_buffers;
975
976 /*
977 * q->num_buffers contains the total number of buffers, that the
978 * queue driver has set up
979 */
980 ret = call_qop(q, queue_setup, q, &num_buffers,
981 &num_planes, plane_sizes, q->alloc_devs);
982
983 if (!ret && allocated_buffers < num_buffers)
984 ret = -ENOMEM;
985
986 /*
987 * Either the driver has accepted a smaller number of buffers,
988 * or .queue_setup() returned an error
989 */
990 }
991
992 mutex_lock(&q->mmap_lock);
993 q->num_buffers += allocated_buffers;
994
995 if (ret < 0) {
996 /*
997 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
998 * from q->num_buffers and it will reset q->memory to
999 * VB2_MEMORY_UNKNOWN.
1000 */
1001 __vb2_queue_free(q, allocated_buffers);
1002 mutex_unlock(&q->mmap_lock);
1003 return -ENOMEM;
1004 }
1005 mutex_unlock(&q->mmap_lock);
1006
1007 /*
1008 * Return the number of successfully allocated buffers
1009 * to the userspace.
1010 */
1011 *count = allocated_buffers;
1012
1013 return 0;
1014
1015 error:
1016 if (no_previous_buffers) {
1017 mutex_lock(&q->mmap_lock);
1018 q->memory = VB2_MEMORY_UNKNOWN;
1019 mutex_unlock(&q->mmap_lock);
1020 }
1021 return ret;
1022 }
1023 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
1024
vb2_plane_vaddr(struct vb2_buffer * vb,unsigned int plane_no)1025 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1026 {
1027 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1028 return NULL;
1029
1030 return call_ptr_memop(vaddr, vb, vb->planes[plane_no].mem_priv);
1031
1032 }
1033 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1034
vb2_plane_cookie(struct vb2_buffer * vb,unsigned int plane_no)1035 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1036 {
1037 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1038 return NULL;
1039
1040 return call_ptr_memop(cookie, vb, vb->planes[plane_no].mem_priv);
1041 }
1042 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1043
vb2_buffer_done(struct vb2_buffer * vb,enum vb2_buffer_state state)1044 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1045 {
1046 struct vb2_queue *q = vb->vb2_queue;
1047 unsigned long flags;
1048
1049 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1050 return;
1051
1052 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1053 state != VB2_BUF_STATE_ERROR &&
1054 state != VB2_BUF_STATE_QUEUED))
1055 state = VB2_BUF_STATE_ERROR;
1056
1057 #ifdef CONFIG_VIDEO_ADV_DEBUG
1058 /*
1059 * Although this is not a callback, it still does have to balance
1060 * with the buf_queue op. So update this counter manually.
1061 */
1062 vb->cnt_buf_done++;
1063 #endif
1064 dprintk(q, 4, "done processing on buffer %d, state: %s\n",
1065 vb->index, vb2_state_name(state));
1066
1067 if (state != VB2_BUF_STATE_QUEUED)
1068 __vb2_buf_mem_finish(vb);
1069
1070 spin_lock_irqsave(&q->done_lock, flags);
1071 if (state == VB2_BUF_STATE_QUEUED) {
1072 vb->state = VB2_BUF_STATE_QUEUED;
1073 } else {
1074 /* Add the buffer to the done buffers list */
1075 list_add_tail(&vb->done_entry, &q->done_list);
1076 vb->state = state;
1077 }
1078 atomic_dec(&q->owned_by_drv_count);
1079
1080 if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
1081 media_request_object_unbind(&vb->req_obj);
1082 media_request_object_put(&vb->req_obj);
1083 }
1084
1085 spin_unlock_irqrestore(&q->done_lock, flags);
1086
1087 trace_vb2_buf_done(q, vb);
1088
1089 switch (state) {
1090 case VB2_BUF_STATE_QUEUED:
1091 return;
1092 default:
1093 /* Inform any processes that may be waiting for buffers */
1094 wake_up(&q->done_wq);
1095 break;
1096 }
1097 }
1098 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1099
vb2_discard_done(struct vb2_queue * q)1100 void vb2_discard_done(struct vb2_queue *q)
1101 {
1102 struct vb2_buffer *vb;
1103 unsigned long flags;
1104
1105 spin_lock_irqsave(&q->done_lock, flags);
1106 list_for_each_entry(vb, &q->done_list, done_entry)
1107 vb->state = VB2_BUF_STATE_ERROR;
1108 spin_unlock_irqrestore(&q->done_lock, flags);
1109 }
1110 EXPORT_SYMBOL_GPL(vb2_discard_done);
1111
1112 /*
1113 * __prepare_mmap() - prepare an MMAP buffer
1114 */
__prepare_mmap(struct vb2_buffer * vb)1115 static int __prepare_mmap(struct vb2_buffer *vb)
1116 {
1117 int ret = 0;
1118
1119 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1120 vb, vb->planes);
1121 return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
1122 }
1123
1124 /*
1125 * __prepare_userptr() - prepare a USERPTR buffer
1126 */
__prepare_userptr(struct vb2_buffer * vb)1127 static int __prepare_userptr(struct vb2_buffer *vb)
1128 {
1129 struct vb2_plane planes[VB2_MAX_PLANES];
1130 struct vb2_queue *q = vb->vb2_queue;
1131 void *mem_priv;
1132 unsigned int plane;
1133 int ret = 0;
1134 bool reacquired = vb->planes[0].mem_priv == NULL;
1135
1136 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1137 /* Copy relevant information provided by the userspace */
1138 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1139 vb, planes);
1140 if (ret)
1141 return ret;
1142
1143 for (plane = 0; plane < vb->num_planes; ++plane) {
1144 /* Skip the plane if already verified */
1145 if (vb->planes[plane].m.userptr &&
1146 vb->planes[plane].m.userptr == planes[plane].m.userptr
1147 && vb->planes[plane].length == planes[plane].length)
1148 continue;
1149
1150 dprintk(q, 3, "userspace address for plane %d changed, reacquiring memory\n",
1151 plane);
1152
1153 /* Check if the provided plane buffer is large enough */
1154 if (planes[plane].length < vb->planes[plane].min_length) {
1155 dprintk(q, 1, "provided buffer size %u is less than setup size %u for plane %d\n",
1156 planes[plane].length,
1157 vb->planes[plane].min_length,
1158 plane);
1159 ret = -EINVAL;
1160 goto err;
1161 }
1162
1163 /* Release previously acquired memory if present */
1164 if (vb->planes[plane].mem_priv) {
1165 if (!reacquired) {
1166 reacquired = true;
1167 vb->copied_timestamp = 0;
1168 call_void_vb_qop(vb, buf_cleanup, vb);
1169 }
1170 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1171 }
1172
1173 vb->planes[plane].mem_priv = NULL;
1174 vb->planes[plane].bytesused = 0;
1175 vb->planes[plane].length = 0;
1176 vb->planes[plane].m.userptr = 0;
1177 vb->planes[plane].data_offset = 0;
1178
1179 /* Acquire each plane's memory */
1180 mem_priv = call_ptr_memop(get_userptr,
1181 vb,
1182 q->alloc_devs[plane] ? : q->dev,
1183 planes[plane].m.userptr,
1184 planes[plane].length);
1185 if (IS_ERR(mem_priv)) {
1186 dprintk(q, 1, "failed acquiring userspace memory for plane %d\n",
1187 plane);
1188 ret = PTR_ERR(mem_priv);
1189 goto err;
1190 }
1191 vb->planes[plane].mem_priv = mem_priv;
1192 }
1193
1194 /*
1195 * Now that everything is in order, copy relevant information
1196 * provided by userspace.
1197 */
1198 for (plane = 0; plane < vb->num_planes; ++plane) {
1199 vb->planes[plane].bytesused = planes[plane].bytesused;
1200 vb->planes[plane].length = planes[plane].length;
1201 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1202 vb->planes[plane].data_offset = planes[plane].data_offset;
1203 }
1204
1205 if (reacquired) {
1206 /*
1207 * One or more planes changed, so we must call buf_init to do
1208 * the driver-specific initialization on the newly acquired
1209 * buffer, if provided.
1210 */
1211 ret = call_vb_qop(vb, buf_init, vb);
1212 if (ret) {
1213 dprintk(q, 1, "buffer initialization failed\n");
1214 goto err;
1215 }
1216 }
1217
1218 ret = call_vb_qop(vb, buf_prepare, vb);
1219 if (ret) {
1220 dprintk(q, 1, "buffer preparation failed\n");
1221 call_void_vb_qop(vb, buf_cleanup, vb);
1222 goto err;
1223 }
1224
1225 return 0;
1226 err:
1227 /* In case of errors, release planes that were already acquired */
1228 for (plane = 0; plane < vb->num_planes; ++plane) {
1229 if (vb->planes[plane].mem_priv)
1230 call_void_memop(vb, put_userptr,
1231 vb->planes[plane].mem_priv);
1232 vb->planes[plane].mem_priv = NULL;
1233 vb->planes[plane].m.userptr = 0;
1234 vb->planes[plane].length = 0;
1235 }
1236
1237 return ret;
1238 }
1239
1240 /*
1241 * __prepare_dmabuf() - prepare a DMABUF buffer
1242 */
__prepare_dmabuf(struct vb2_buffer * vb)1243 static int __prepare_dmabuf(struct vb2_buffer *vb)
1244 {
1245 struct vb2_plane planes[VB2_MAX_PLANES];
1246 struct vb2_queue *q = vb->vb2_queue;
1247 void *mem_priv;
1248 unsigned int plane;
1249 int ret = 0;
1250 bool reacquired = vb->planes[0].mem_priv == NULL;
1251
1252 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1253 /* Copy relevant information provided by the userspace */
1254 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1255 vb, planes);
1256 if (ret)
1257 return ret;
1258
1259 for (plane = 0; plane < vb->num_planes; ++plane) {
1260 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1261
1262 if (IS_ERR_OR_NULL(dbuf)) {
1263 dprintk(q, 1, "invalid dmabuf fd for plane %d\n",
1264 plane);
1265 ret = -EINVAL;
1266 goto err;
1267 }
1268
1269 /* use DMABUF size if length is not provided */
1270 if (planes[plane].length == 0)
1271 planes[plane].length = dbuf->size;
1272
1273 if (planes[plane].length < vb->planes[plane].min_length) {
1274 dprintk(q, 1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1275 planes[plane].length, plane,
1276 vb->planes[plane].min_length);
1277 dma_buf_put(dbuf);
1278 ret = -EINVAL;
1279 goto err;
1280 }
1281
1282 /* Skip the plane if already verified */
1283 if (dbuf == vb->planes[plane].dbuf &&
1284 vb->planes[plane].length == planes[plane].length) {
1285 dma_buf_put(dbuf);
1286 continue;
1287 }
1288
1289 dprintk(q, 3, "buffer for plane %d changed\n", plane);
1290
1291 if (!reacquired) {
1292 reacquired = true;
1293 vb->copied_timestamp = 0;
1294 call_void_vb_qop(vb, buf_cleanup, vb);
1295 }
1296
1297 /* Release previously acquired memory if present */
1298 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1299 vb->planes[plane].bytesused = 0;
1300 vb->planes[plane].length = 0;
1301 vb->planes[plane].m.fd = 0;
1302 vb->planes[plane].data_offset = 0;
1303
1304 /* Acquire each plane's memory */
1305 mem_priv = call_ptr_memop(attach_dmabuf,
1306 vb,
1307 q->alloc_devs[plane] ? : q->dev,
1308 dbuf,
1309 planes[plane].length);
1310 if (IS_ERR(mem_priv)) {
1311 dprintk(q, 1, "failed to attach dmabuf\n");
1312 ret = PTR_ERR(mem_priv);
1313 dma_buf_put(dbuf);
1314 goto err;
1315 }
1316
1317 vb->planes[plane].dbuf = dbuf;
1318 vb->planes[plane].mem_priv = mem_priv;
1319 }
1320
1321 /*
1322 * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1323 * here instead just before the DMA, while queueing the buffer(s) so
1324 * userspace knows sooner rather than later if the dma-buf map fails.
1325 */
1326 for (plane = 0; plane < vb->num_planes; ++plane) {
1327 if (vb->planes[plane].dbuf_mapped)
1328 continue;
1329
1330 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1331 if (ret) {
1332 dprintk(q, 1, "failed to map dmabuf for plane %d\n",
1333 plane);
1334 goto err;
1335 }
1336 vb->planes[plane].dbuf_mapped = 1;
1337 }
1338
1339 /*
1340 * Now that everything is in order, copy relevant information
1341 * provided by userspace.
1342 */
1343 for (plane = 0; plane < vb->num_planes; ++plane) {
1344 vb->planes[plane].bytesused = planes[plane].bytesused;
1345 vb->planes[plane].length = planes[plane].length;
1346 vb->planes[plane].m.fd = planes[plane].m.fd;
1347 vb->planes[plane].data_offset = planes[plane].data_offset;
1348 }
1349
1350 if (reacquired) {
1351 /*
1352 * Call driver-specific initialization on the newly acquired buffer,
1353 * if provided.
1354 */
1355 ret = call_vb_qop(vb, buf_init, vb);
1356 if (ret) {
1357 dprintk(q, 1, "buffer initialization failed\n");
1358 goto err;
1359 }
1360 }
1361
1362 ret = call_vb_qop(vb, buf_prepare, vb);
1363 if (ret) {
1364 dprintk(q, 1, "buffer preparation failed\n");
1365 call_void_vb_qop(vb, buf_cleanup, vb);
1366 goto err;
1367 }
1368
1369 return 0;
1370 err:
1371 /* In case of errors, release planes that were already acquired */
1372 __vb2_buf_dmabuf_put(vb);
1373
1374 return ret;
1375 }
1376
1377 /*
1378 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1379 */
__enqueue_in_driver(struct vb2_buffer * vb)1380 static void __enqueue_in_driver(struct vb2_buffer *vb)
1381 {
1382 struct vb2_queue *q = vb->vb2_queue;
1383
1384 vb->state = VB2_BUF_STATE_ACTIVE;
1385 atomic_inc(&q->owned_by_drv_count);
1386
1387 trace_vb2_buf_queue(q, vb);
1388
1389 call_void_vb_qop(vb, buf_queue, vb);
1390 }
1391
__buf_prepare(struct vb2_buffer * vb)1392 static int __buf_prepare(struct vb2_buffer *vb)
1393 {
1394 struct vb2_queue *q = vb->vb2_queue;
1395 enum vb2_buffer_state orig_state = vb->state;
1396 int ret;
1397
1398 if (q->error) {
1399 dprintk(q, 1, "fatal error occurred on queue\n");
1400 return -EIO;
1401 }
1402
1403 if (vb->prepared)
1404 return 0;
1405 WARN_ON(vb->synced);
1406
1407 if (q->is_output) {
1408 ret = call_vb_qop(vb, buf_out_validate, vb);
1409 if (ret) {
1410 dprintk(q, 1, "buffer validation failed\n");
1411 return ret;
1412 }
1413 }
1414
1415 vb->state = VB2_BUF_STATE_PREPARING;
1416
1417 switch (q->memory) {
1418 case VB2_MEMORY_MMAP:
1419 ret = __prepare_mmap(vb);
1420 break;
1421 case VB2_MEMORY_USERPTR:
1422 ret = __prepare_userptr(vb);
1423 break;
1424 case VB2_MEMORY_DMABUF:
1425 ret = __prepare_dmabuf(vb);
1426 break;
1427 default:
1428 WARN(1, "Invalid queue type\n");
1429 ret = -EINVAL;
1430 break;
1431 }
1432
1433 if (ret) {
1434 dprintk(q, 1, "buffer preparation failed: %d\n", ret);
1435 vb->state = orig_state;
1436 return ret;
1437 }
1438
1439 __vb2_buf_mem_prepare(vb);
1440 vb->prepared = 1;
1441 vb->state = orig_state;
1442
1443 return 0;
1444 }
1445
vb2_req_prepare(struct media_request_object * obj)1446 static int vb2_req_prepare(struct media_request_object *obj)
1447 {
1448 struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1449 int ret;
1450
1451 if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
1452 return -EINVAL;
1453
1454 mutex_lock(vb->vb2_queue->lock);
1455 ret = __buf_prepare(vb);
1456 mutex_unlock(vb->vb2_queue->lock);
1457 return ret;
1458 }
1459
1460 static void __vb2_dqbuf(struct vb2_buffer *vb);
1461
vb2_req_unprepare(struct media_request_object * obj)1462 static void vb2_req_unprepare(struct media_request_object *obj)
1463 {
1464 struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1465
1466 mutex_lock(vb->vb2_queue->lock);
1467 __vb2_dqbuf(vb);
1468 vb->state = VB2_BUF_STATE_IN_REQUEST;
1469 mutex_unlock(vb->vb2_queue->lock);
1470 WARN_ON(!vb->req_obj.req);
1471 }
1472
1473 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1474 struct media_request *req);
1475
vb2_req_queue(struct media_request_object * obj)1476 static void vb2_req_queue(struct media_request_object *obj)
1477 {
1478 struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1479 int err;
1480
1481 mutex_lock(vb->vb2_queue->lock);
1482 /*
1483 * There is no method to propagate an error from vb2_core_qbuf(),
1484 * so if this returns a non-0 value, then WARN.
1485 *
1486 * The only exception is -EIO which is returned if q->error is
1487 * set. We just ignore that, and expect this will be caught the
1488 * next time vb2_req_prepare() is called.
1489 */
1490 err = vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
1491 WARN_ON_ONCE(err && err != -EIO);
1492 mutex_unlock(vb->vb2_queue->lock);
1493 }
1494
vb2_req_unbind(struct media_request_object * obj)1495 static void vb2_req_unbind(struct media_request_object *obj)
1496 {
1497 struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1498
1499 if (vb->state == VB2_BUF_STATE_IN_REQUEST)
1500 call_void_bufop(vb->vb2_queue, init_buffer, vb);
1501 }
1502
vb2_req_release(struct media_request_object * obj)1503 static void vb2_req_release(struct media_request_object *obj)
1504 {
1505 struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1506
1507 if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
1508 vb->state = VB2_BUF_STATE_DEQUEUED;
1509 if (vb->request)
1510 media_request_put(vb->request);
1511 vb->request = NULL;
1512 }
1513 }
1514
1515 static const struct media_request_object_ops vb2_core_req_ops = {
1516 .prepare = vb2_req_prepare,
1517 .unprepare = vb2_req_unprepare,
1518 .queue = vb2_req_queue,
1519 .unbind = vb2_req_unbind,
1520 .release = vb2_req_release,
1521 };
1522
vb2_request_object_is_buffer(struct media_request_object * obj)1523 bool vb2_request_object_is_buffer(struct media_request_object *obj)
1524 {
1525 return obj->ops == &vb2_core_req_ops;
1526 }
1527 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
1528
vb2_request_buffer_cnt(struct media_request * req)1529 unsigned int vb2_request_buffer_cnt(struct media_request *req)
1530 {
1531 struct media_request_object *obj;
1532 unsigned long flags;
1533 unsigned int buffer_cnt = 0;
1534
1535 spin_lock_irqsave(&req->lock, flags);
1536 list_for_each_entry(obj, &req->objects, list)
1537 if (vb2_request_object_is_buffer(obj))
1538 buffer_cnt++;
1539 spin_unlock_irqrestore(&req->lock, flags);
1540
1541 return buffer_cnt;
1542 }
1543 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
1544
vb2_core_prepare_buf(struct vb2_queue * q,unsigned int index,void * pb)1545 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1546 {
1547 struct vb2_buffer *vb;
1548 int ret;
1549
1550 vb = q->bufs[index];
1551 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1552 dprintk(q, 1, "invalid buffer state %s\n",
1553 vb2_state_name(vb->state));
1554 return -EINVAL;
1555 }
1556 if (vb->prepared) {
1557 dprintk(q, 1, "buffer already prepared\n");
1558 return -EINVAL;
1559 }
1560
1561 ret = __buf_prepare(vb);
1562 if (ret)
1563 return ret;
1564
1565 /* Fill buffer information for the userspace */
1566 call_void_bufop(q, fill_user_buffer, vb, pb);
1567
1568 dprintk(q, 2, "prepare of buffer %d succeeded\n", vb->index);
1569
1570 return 0;
1571 }
1572 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1573
1574 /*
1575 * vb2_start_streaming() - Attempt to start streaming.
1576 * @q: videobuf2 queue
1577 *
1578 * Attempt to start streaming. When this function is called there must be
1579 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1580 * number of buffers required for the DMA engine to function). If the
1581 * @start_streaming op fails it is supposed to return all the driver-owned
1582 * buffers back to vb2 in state QUEUED. Check if that happened and if
1583 * not warn and reclaim them forcefully.
1584 */
vb2_start_streaming(struct vb2_queue * q)1585 static int vb2_start_streaming(struct vb2_queue *q)
1586 {
1587 struct vb2_buffer *vb;
1588 int ret;
1589
1590 /*
1591 * If any buffers were queued before streamon,
1592 * we can now pass them to driver for processing.
1593 */
1594 list_for_each_entry(vb, &q->queued_list, queued_entry)
1595 __enqueue_in_driver(vb);
1596
1597 /* Tell the driver to start streaming */
1598 q->start_streaming_called = 1;
1599 ret = call_qop(q, start_streaming, q,
1600 atomic_read(&q->owned_by_drv_count));
1601 if (!ret)
1602 return 0;
1603
1604 q->start_streaming_called = 0;
1605
1606 dprintk(q, 1, "driver refused to start streaming\n");
1607 /*
1608 * If you see this warning, then the driver isn't cleaning up properly
1609 * after a failed start_streaming(). See the start_streaming()
1610 * documentation in videobuf2-core.h for more information how buffers
1611 * should be returned to vb2 in start_streaming().
1612 */
1613 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1614 unsigned i;
1615
1616 /*
1617 * Forcefully reclaim buffers if the driver did not
1618 * correctly return them to vb2.
1619 */
1620 for (i = 0; i < q->num_buffers; ++i) {
1621 vb = q->bufs[i];
1622 if (vb->state == VB2_BUF_STATE_ACTIVE)
1623 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1624 }
1625 /* Must be zero now */
1626 WARN_ON(atomic_read(&q->owned_by_drv_count));
1627 }
1628 /*
1629 * If done_list is not empty, then start_streaming() didn't call
1630 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1631 * STATE_DONE.
1632 */
1633 WARN_ON(!list_empty(&q->done_list));
1634 return ret;
1635 }
1636
vb2_core_qbuf(struct vb2_queue * q,unsigned int index,void * pb,struct media_request * req)1637 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1638 struct media_request *req)
1639 {
1640 struct vb2_buffer *vb;
1641 enum vb2_buffer_state orig_state;
1642 int ret;
1643
1644 if (q->error) {
1645 dprintk(q, 1, "fatal error occurred on queue\n");
1646 return -EIO;
1647 }
1648
1649 vb = q->bufs[index];
1650
1651 if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1652 q->requires_requests) {
1653 dprintk(q, 1, "qbuf requires a request\n");
1654 return -EBADR;
1655 }
1656
1657 if ((req && q->uses_qbuf) ||
1658 (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1659 q->uses_requests)) {
1660 dprintk(q, 1, "queue in wrong mode (qbuf vs requests)\n");
1661 return -EBUSY;
1662 }
1663
1664 if (req) {
1665 int ret;
1666
1667 q->uses_requests = 1;
1668 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1669 dprintk(q, 1, "buffer %d not in dequeued state\n",
1670 vb->index);
1671 return -EINVAL;
1672 }
1673
1674 if (q->is_output && !vb->prepared) {
1675 ret = call_vb_qop(vb, buf_out_validate, vb);
1676 if (ret) {
1677 dprintk(q, 1, "buffer validation failed\n");
1678 return ret;
1679 }
1680 }
1681
1682 media_request_object_init(&vb->req_obj);
1683
1684 /* Make sure the request is in a safe state for updating. */
1685 ret = media_request_lock_for_update(req);
1686 if (ret)
1687 return ret;
1688 ret = media_request_object_bind(req, &vb2_core_req_ops,
1689 q, true, &vb->req_obj);
1690 media_request_unlock_for_update(req);
1691 if (ret)
1692 return ret;
1693
1694 vb->state = VB2_BUF_STATE_IN_REQUEST;
1695
1696 /*
1697 * Increment the refcount and store the request.
1698 * The request refcount is decremented again when the
1699 * buffer is dequeued. This is to prevent vb2_buffer_done()
1700 * from freeing the request from interrupt context, which can
1701 * happen if the application closed the request fd after
1702 * queueing the request.
1703 */
1704 media_request_get(req);
1705 vb->request = req;
1706
1707 /* Fill buffer information for the userspace */
1708 if (pb) {
1709 call_void_bufop(q, copy_timestamp, vb, pb);
1710 call_void_bufop(q, fill_user_buffer, vb, pb);
1711 }
1712
1713 dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1714 return 0;
1715 }
1716
1717 if (vb->state != VB2_BUF_STATE_IN_REQUEST)
1718 q->uses_qbuf = 1;
1719
1720 switch (vb->state) {
1721 case VB2_BUF_STATE_DEQUEUED:
1722 case VB2_BUF_STATE_IN_REQUEST:
1723 if (!vb->prepared) {
1724 ret = __buf_prepare(vb);
1725 if (ret)
1726 return ret;
1727 }
1728 break;
1729 case VB2_BUF_STATE_PREPARING:
1730 dprintk(q, 1, "buffer still being prepared\n");
1731 return -EINVAL;
1732 default:
1733 dprintk(q, 1, "invalid buffer state %s\n",
1734 vb2_state_name(vb->state));
1735 return -EINVAL;
1736 }
1737
1738 /*
1739 * Add to the queued buffers list, a buffer will stay on it until
1740 * dequeued in dqbuf.
1741 */
1742 orig_state = vb->state;
1743 list_add_tail(&vb->queued_entry, &q->queued_list);
1744 q->queued_count++;
1745 q->waiting_for_buffers = false;
1746 vb->state = VB2_BUF_STATE_QUEUED;
1747
1748 if (pb)
1749 call_void_bufop(q, copy_timestamp, vb, pb);
1750
1751 trace_vb2_qbuf(q, vb);
1752
1753 /*
1754 * If already streaming, give the buffer to driver for processing.
1755 * If not, the buffer will be given to driver on next streamon.
1756 */
1757 if (q->start_streaming_called)
1758 __enqueue_in_driver(vb);
1759
1760 /* Fill buffer information for the userspace */
1761 if (pb)
1762 call_void_bufop(q, fill_user_buffer, vb, pb);
1763
1764 /*
1765 * If streamon has been called, and we haven't yet called
1766 * start_streaming() since not enough buffers were queued, and
1767 * we now have reached the minimum number of queued buffers,
1768 * then we can finally call start_streaming().
1769 */
1770 if (q->streaming && !q->start_streaming_called &&
1771 q->queued_count >= q->min_buffers_needed) {
1772 ret = vb2_start_streaming(q);
1773 if (ret) {
1774 /*
1775 * Since vb2_core_qbuf will return with an error,
1776 * we should return it to state DEQUEUED since
1777 * the error indicates that the buffer wasn't queued.
1778 */
1779 list_del(&vb->queued_entry);
1780 q->queued_count--;
1781 vb->state = orig_state;
1782 return ret;
1783 }
1784 }
1785
1786 dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1787 return 0;
1788 }
1789 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1790
1791 /*
1792 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1793 * for dequeuing
1794 *
1795 * Will sleep if required for nonblocking == false.
1796 */
__vb2_wait_for_done_vb(struct vb2_queue * q,int nonblocking)1797 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1798 {
1799 /*
1800 * All operations on vb_done_list are performed under done_lock
1801 * spinlock protection. However, buffers may be removed from
1802 * it and returned to userspace only while holding both driver's
1803 * lock and the done_lock spinlock. Thus we can be sure that as
1804 * long as we hold the driver's lock, the list will remain not
1805 * empty if list_empty() check succeeds.
1806 */
1807
1808 for (;;) {
1809 int ret;
1810
1811 if (q->waiting_in_dqbuf) {
1812 dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
1813 return -EBUSY;
1814 }
1815
1816 if (!q->streaming) {
1817 dprintk(q, 1, "streaming off, will not wait for buffers\n");
1818 return -EINVAL;
1819 }
1820
1821 if (q->error) {
1822 dprintk(q, 1, "Queue in error state, will not wait for buffers\n");
1823 return -EIO;
1824 }
1825
1826 if (q->last_buffer_dequeued) {
1827 dprintk(q, 3, "last buffer dequeued already, will not wait for buffers\n");
1828 return -EPIPE;
1829 }
1830
1831 if (!list_empty(&q->done_list)) {
1832 /*
1833 * Found a buffer that we were waiting for.
1834 */
1835 break;
1836 }
1837
1838 if (nonblocking) {
1839 dprintk(q, 3, "nonblocking and no buffers to dequeue, will not wait\n");
1840 return -EAGAIN;
1841 }
1842
1843 q->waiting_in_dqbuf = 1;
1844 /*
1845 * We are streaming and blocking, wait for another buffer to
1846 * become ready or for streamoff. Driver's lock is released to
1847 * allow streamoff or qbuf to be called while waiting.
1848 */
1849 call_void_qop(q, wait_prepare, q);
1850
1851 /*
1852 * All locks have been released, it is safe to sleep now.
1853 */
1854 dprintk(q, 3, "will sleep waiting for buffers\n");
1855 ret = wait_event_interruptible(q->done_wq,
1856 !list_empty(&q->done_list) || !q->streaming ||
1857 q->error);
1858
1859 /*
1860 * We need to reevaluate both conditions again after reacquiring
1861 * the locks or return an error if one occurred.
1862 */
1863 call_void_qop(q, wait_finish, q);
1864 q->waiting_in_dqbuf = 0;
1865 if (ret) {
1866 dprintk(q, 1, "sleep was interrupted\n");
1867 return ret;
1868 }
1869 }
1870 return 0;
1871 }
1872
1873 /*
1874 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1875 *
1876 * Will sleep if required for nonblocking == false.
1877 */
__vb2_get_done_vb(struct vb2_queue * q,struct vb2_buffer ** vb,void * pb,int nonblocking)1878 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1879 void *pb, int nonblocking)
1880 {
1881 unsigned long flags;
1882 int ret = 0;
1883
1884 /*
1885 * Wait for at least one buffer to become available on the done_list.
1886 */
1887 ret = __vb2_wait_for_done_vb(q, nonblocking);
1888 if (ret)
1889 return ret;
1890
1891 /*
1892 * Driver's lock has been held since we last verified that done_list
1893 * is not empty, so no need for another list_empty(done_list) check.
1894 */
1895 spin_lock_irqsave(&q->done_lock, flags);
1896 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1897 /*
1898 * Only remove the buffer from done_list if all planes can be
1899 * handled. Some cases such as V4L2 file I/O and DVB have pb
1900 * == NULL; skip the check then as there's nothing to verify.
1901 */
1902 if (pb)
1903 ret = call_bufop(q, verify_planes_array, *vb, pb);
1904 if (!ret)
1905 list_del(&(*vb)->done_entry);
1906 spin_unlock_irqrestore(&q->done_lock, flags);
1907
1908 return ret;
1909 }
1910
vb2_wait_for_all_buffers(struct vb2_queue * q)1911 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1912 {
1913 if (!q->streaming) {
1914 dprintk(q, 1, "streaming off, will not wait for buffers\n");
1915 return -EINVAL;
1916 }
1917
1918 if (q->start_streaming_called)
1919 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1920 return 0;
1921 }
1922 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1923
1924 /*
1925 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1926 */
__vb2_dqbuf(struct vb2_buffer * vb)1927 static void __vb2_dqbuf(struct vb2_buffer *vb)
1928 {
1929 struct vb2_queue *q = vb->vb2_queue;
1930
1931 /* nothing to do if the buffer is already dequeued */
1932 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1933 return;
1934
1935 vb->state = VB2_BUF_STATE_DEQUEUED;
1936
1937 call_void_bufop(q, init_buffer, vb);
1938 }
1939
vb2_core_dqbuf(struct vb2_queue * q,unsigned int * pindex,void * pb,bool nonblocking)1940 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1941 bool nonblocking)
1942 {
1943 struct vb2_buffer *vb = NULL;
1944 int ret;
1945
1946 ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1947 if (ret < 0)
1948 return ret;
1949
1950 switch (vb->state) {
1951 case VB2_BUF_STATE_DONE:
1952 dprintk(q, 3, "returning done buffer\n");
1953 break;
1954 case VB2_BUF_STATE_ERROR:
1955 dprintk(q, 3, "returning done buffer with errors\n");
1956 break;
1957 default:
1958 dprintk(q, 1, "invalid buffer state %s\n",
1959 vb2_state_name(vb->state));
1960 return -EINVAL;
1961 }
1962
1963 call_void_vb_qop(vb, buf_finish, vb);
1964 vb->prepared = 0;
1965
1966 if (pindex)
1967 *pindex = vb->index;
1968
1969 /* Fill buffer information for the userspace */
1970 if (pb)
1971 call_void_bufop(q, fill_user_buffer, vb, pb);
1972
1973 /* Remove from vb2 queue */
1974 list_del(&vb->queued_entry);
1975 q->queued_count--;
1976
1977 trace_vb2_dqbuf(q, vb);
1978
1979 /* go back to dequeued state */
1980 __vb2_dqbuf(vb);
1981
1982 if (WARN_ON(vb->req_obj.req)) {
1983 media_request_object_unbind(&vb->req_obj);
1984 media_request_object_put(&vb->req_obj);
1985 }
1986 if (vb->request)
1987 media_request_put(vb->request);
1988 vb->request = NULL;
1989
1990 dprintk(q, 2, "dqbuf of buffer %d, state: %s\n",
1991 vb->index, vb2_state_name(vb->state));
1992
1993 return 0;
1994
1995 }
1996 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1997
1998 /*
1999 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2000 *
2001 * Removes all queued buffers from driver's queue and all buffers queued by
2002 * userspace from vb2's queue. Returns to state after reqbufs.
2003 */
__vb2_queue_cancel(struct vb2_queue * q)2004 static void __vb2_queue_cancel(struct vb2_queue *q)
2005 {
2006 unsigned int i;
2007
2008 /*
2009 * Tell driver to stop all transactions and release all queued
2010 * buffers.
2011 */
2012 if (q->start_streaming_called)
2013 call_void_qop(q, stop_streaming, q);
2014
2015 if (q->streaming)
2016 call_void_qop(q, unprepare_streaming, q);
2017
2018 /*
2019 * If you see this warning, then the driver isn't cleaning up properly
2020 * in stop_streaming(). See the stop_streaming() documentation in
2021 * videobuf2-core.h for more information how buffers should be returned
2022 * to vb2 in stop_streaming().
2023 */
2024 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2025 for (i = 0; i < q->num_buffers; ++i)
2026 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
2027 pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
2028 q->bufs[i]);
2029 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2030 }
2031 /* Must be zero now */
2032 WARN_ON(atomic_read(&q->owned_by_drv_count));
2033 }
2034
2035 q->streaming = 0;
2036 q->start_streaming_called = 0;
2037 q->queued_count = 0;
2038 q->error = 0;
2039 q->uses_requests = 0;
2040 q->uses_qbuf = 0;
2041
2042 /*
2043 * Remove all buffers from vb2's list...
2044 */
2045 INIT_LIST_HEAD(&q->queued_list);
2046 /*
2047 * ...and done list; userspace will not receive any buffers it
2048 * has not already dequeued before initiating cancel.
2049 */
2050 INIT_LIST_HEAD(&q->done_list);
2051 atomic_set(&q->owned_by_drv_count, 0);
2052 wake_up_all(&q->done_wq);
2053
2054 /*
2055 * Reinitialize all buffers for next use.
2056 * Make sure to call buf_finish for any queued buffers. Normally
2057 * that's done in dqbuf, but that's not going to happen when we
2058 * cancel the whole queue. Note: this code belongs here, not in
2059 * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
2060 * call to __fill_user_buffer() after buf_finish(). That order can't
2061 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2062 */
2063 for (i = 0; i < q->num_buffers; ++i) {
2064 struct vb2_buffer *vb = q->bufs[i];
2065 struct media_request *req = vb->req_obj.req;
2066
2067 /*
2068 * If a request is associated with this buffer, then
2069 * call buf_request_cancel() to give the driver to complete()
2070 * related request objects. Otherwise those objects would
2071 * never complete.
2072 */
2073 if (req) {
2074 enum media_request_state state;
2075 unsigned long flags;
2076
2077 spin_lock_irqsave(&req->lock, flags);
2078 state = req->state;
2079 spin_unlock_irqrestore(&req->lock, flags);
2080
2081 if (state == MEDIA_REQUEST_STATE_QUEUED)
2082 call_void_vb_qop(vb, buf_request_complete, vb);
2083 }
2084
2085 __vb2_buf_mem_finish(vb);
2086
2087 if (vb->prepared) {
2088 call_void_vb_qop(vb, buf_finish, vb);
2089 vb->prepared = 0;
2090 }
2091 __vb2_dqbuf(vb);
2092
2093 if (vb->req_obj.req) {
2094 media_request_object_unbind(&vb->req_obj);
2095 media_request_object_put(&vb->req_obj);
2096 }
2097 if (vb->request)
2098 media_request_put(vb->request);
2099 vb->request = NULL;
2100 vb->copied_timestamp = 0;
2101 }
2102 }
2103
vb2_core_streamon(struct vb2_queue * q,unsigned int type)2104 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
2105 {
2106 int ret;
2107
2108 if (type != q->type) {
2109 dprintk(q, 1, "invalid stream type\n");
2110 return -EINVAL;
2111 }
2112
2113 if (q->streaming) {
2114 dprintk(q, 3, "already streaming\n");
2115 return 0;
2116 }
2117
2118 if (!q->num_buffers) {
2119 dprintk(q, 1, "no buffers have been allocated\n");
2120 return -EINVAL;
2121 }
2122
2123 if (q->num_buffers < q->min_buffers_needed) {
2124 dprintk(q, 1, "need at least %u allocated buffers\n",
2125 q->min_buffers_needed);
2126 return -EINVAL;
2127 }
2128
2129 ret = call_qop(q, prepare_streaming, q);
2130 if (ret)
2131 return ret;
2132
2133 /*
2134 * Tell driver to start streaming provided sufficient buffers
2135 * are available.
2136 */
2137 if (q->queued_count >= q->min_buffers_needed) {
2138 ret = vb2_start_streaming(q);
2139 if (ret)
2140 goto unprepare;
2141 }
2142
2143 q->streaming = 1;
2144
2145 dprintk(q, 3, "successful\n");
2146 return 0;
2147
2148 unprepare:
2149 call_void_qop(q, unprepare_streaming, q);
2150 return ret;
2151 }
2152 EXPORT_SYMBOL_GPL(vb2_core_streamon);
2153
vb2_queue_error(struct vb2_queue * q)2154 void vb2_queue_error(struct vb2_queue *q)
2155 {
2156 q->error = 1;
2157
2158 wake_up_all(&q->done_wq);
2159 }
2160 EXPORT_SYMBOL_GPL(vb2_queue_error);
2161
vb2_core_streamoff(struct vb2_queue * q,unsigned int type)2162 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
2163 {
2164 if (type != q->type) {
2165 dprintk(q, 1, "invalid stream type\n");
2166 return -EINVAL;
2167 }
2168
2169 /*
2170 * Cancel will pause streaming and remove all buffers from the driver
2171 * and vb2, effectively returning control over them to userspace.
2172 *
2173 * Note that we do this even if q->streaming == 0: if you prepare or
2174 * queue buffers, and then call streamoff without ever having called
2175 * streamon, you would still expect those buffers to be returned to
2176 * their normal dequeued state.
2177 */
2178 __vb2_queue_cancel(q);
2179 q->waiting_for_buffers = !q->is_output;
2180 q->last_buffer_dequeued = false;
2181
2182 dprintk(q, 3, "successful\n");
2183 return 0;
2184 }
2185 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
2186
2187 /*
2188 * __find_plane_by_offset() - find plane associated with the given offset off
2189 */
__find_plane_by_offset(struct vb2_queue * q,unsigned long off,unsigned int * _buffer,unsigned int * _plane)2190 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2191 unsigned int *_buffer, unsigned int *_plane)
2192 {
2193 struct vb2_buffer *vb;
2194 unsigned int buffer, plane;
2195
2196 /*
2197 * Sanity checks to ensure the lock is held, MEMORY_MMAP is
2198 * used and fileio isn't active.
2199 */
2200 lockdep_assert_held(&q->mmap_lock);
2201
2202 if (q->memory != VB2_MEMORY_MMAP) {
2203 dprintk(q, 1, "queue is not currently set up for mmap\n");
2204 return -EINVAL;
2205 }
2206
2207 if (vb2_fileio_is_active(q)) {
2208 dprintk(q, 1, "file io in progress\n");
2209 return -EBUSY;
2210 }
2211
2212 /*
2213 * Go over all buffers and their planes, comparing the given offset
2214 * with an offset assigned to each plane. If a match is found,
2215 * return its buffer and plane numbers.
2216 */
2217 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2218 vb = q->bufs[buffer];
2219
2220 for (plane = 0; plane < vb->num_planes; ++plane) {
2221 if (vb->planes[plane].m.offset == off) {
2222 *_buffer = buffer;
2223 *_plane = plane;
2224 return 0;
2225 }
2226 }
2227 }
2228
2229 return -EINVAL;
2230 }
2231
vb2_core_expbuf(struct vb2_queue * q,int * fd,unsigned int type,unsigned int index,unsigned int plane,unsigned int flags)2232 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
2233 unsigned int index, unsigned int plane, unsigned int flags)
2234 {
2235 struct vb2_buffer *vb = NULL;
2236 struct vb2_plane *vb_plane;
2237 int ret;
2238 struct dma_buf *dbuf;
2239
2240 if (q->memory != VB2_MEMORY_MMAP) {
2241 dprintk(q, 1, "queue is not currently set up for mmap\n");
2242 return -EINVAL;
2243 }
2244
2245 if (!q->mem_ops->get_dmabuf) {
2246 dprintk(q, 1, "queue does not support DMA buffer exporting\n");
2247 return -EINVAL;
2248 }
2249
2250 if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2251 dprintk(q, 1, "queue does support only O_CLOEXEC and access mode flags\n");
2252 return -EINVAL;
2253 }
2254
2255 if (type != q->type) {
2256 dprintk(q, 1, "invalid buffer type\n");
2257 return -EINVAL;
2258 }
2259
2260 if (index >= q->num_buffers) {
2261 dprintk(q, 1, "buffer index out of range\n");
2262 return -EINVAL;
2263 }
2264
2265 vb = q->bufs[index];
2266
2267 if (plane >= vb->num_planes) {
2268 dprintk(q, 1, "buffer plane out of range\n");
2269 return -EINVAL;
2270 }
2271
2272 if (vb2_fileio_is_active(q)) {
2273 dprintk(q, 1, "expbuf: file io in progress\n");
2274 return -EBUSY;
2275 }
2276
2277 vb_plane = &vb->planes[plane];
2278
2279 dbuf = call_ptr_memop(get_dmabuf,
2280 vb,
2281 vb_plane->mem_priv,
2282 flags & O_ACCMODE);
2283 if (IS_ERR_OR_NULL(dbuf)) {
2284 dprintk(q, 1, "failed to export buffer %d, plane %d\n",
2285 index, plane);
2286 return -EINVAL;
2287 }
2288
2289 ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2290 if (ret < 0) {
2291 dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",
2292 index, plane, ret);
2293 dma_buf_put(dbuf);
2294 return ret;
2295 }
2296
2297 dprintk(q, 3, "buffer %d, plane %d exported as %d descriptor\n",
2298 index, plane, ret);
2299 *fd = ret;
2300
2301 return 0;
2302 }
2303 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2304
vb2_mmap(struct vb2_queue * q,struct vm_area_struct * vma)2305 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2306 {
2307 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2308 struct vb2_buffer *vb;
2309 unsigned int buffer = 0, plane = 0;
2310 int ret;
2311 unsigned long length;
2312
2313 /*
2314 * Check memory area access mode.
2315 */
2316 if (!(vma->vm_flags & VM_SHARED)) {
2317 dprintk(q, 1, "invalid vma flags, VM_SHARED needed\n");
2318 return -EINVAL;
2319 }
2320 if (q->is_output) {
2321 if (!(vma->vm_flags & VM_WRITE)) {
2322 dprintk(q, 1, "invalid vma flags, VM_WRITE needed\n");
2323 return -EINVAL;
2324 }
2325 } else {
2326 if (!(vma->vm_flags & VM_READ)) {
2327 dprintk(q, 1, "invalid vma flags, VM_READ needed\n");
2328 return -EINVAL;
2329 }
2330 }
2331
2332 mutex_lock(&q->mmap_lock);
2333
2334 /*
2335 * Find the plane corresponding to the offset passed by userspace. This
2336 * will return an error if not MEMORY_MMAP or file I/O is in progress.
2337 */
2338 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2339 if (ret)
2340 goto unlock;
2341
2342 vb = q->bufs[buffer];
2343
2344 /*
2345 * MMAP requires page_aligned buffers.
2346 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2347 * so, we need to do the same here.
2348 */
2349 length = PAGE_ALIGN(vb->planes[plane].length);
2350 if (length < (vma->vm_end - vma->vm_start)) {
2351 dprintk(q, 1,
2352 "MMAP invalid, as it would overflow buffer length\n");
2353 ret = -EINVAL;
2354 goto unlock;
2355 }
2356
2357 /*
2358 * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
2359 * not as a in-buffer offset. We always want to mmap a whole buffer
2360 * from its beginning.
2361 */
2362 vma->vm_pgoff = 0;
2363
2364 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2365
2366 unlock:
2367 mutex_unlock(&q->mmap_lock);
2368 if (ret)
2369 return ret;
2370
2371 dprintk(q, 3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2372 return 0;
2373 }
2374 EXPORT_SYMBOL_GPL(vb2_mmap);
2375
2376 #ifndef CONFIG_MMU
vb2_get_unmapped_area(struct vb2_queue * q,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)2377 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2378 unsigned long addr,
2379 unsigned long len,
2380 unsigned long pgoff,
2381 unsigned long flags)
2382 {
2383 unsigned long off = pgoff << PAGE_SHIFT;
2384 struct vb2_buffer *vb;
2385 unsigned int buffer, plane;
2386 void *vaddr;
2387 int ret;
2388
2389 mutex_lock(&q->mmap_lock);
2390
2391 /*
2392 * Find the plane corresponding to the offset passed by userspace. This
2393 * will return an error if not MEMORY_MMAP or file I/O is in progress.
2394 */
2395 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2396 if (ret)
2397 goto unlock;
2398
2399 vb = q->bufs[buffer];
2400
2401 vaddr = vb2_plane_vaddr(vb, plane);
2402 mutex_unlock(&q->mmap_lock);
2403 return vaddr ? (unsigned long)vaddr : -EINVAL;
2404
2405 unlock:
2406 mutex_unlock(&q->mmap_lock);
2407 return ret;
2408 }
2409 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2410 #endif
2411
vb2_core_queue_init(struct vb2_queue * q)2412 int vb2_core_queue_init(struct vb2_queue *q)
2413 {
2414 /*
2415 * Sanity check
2416 */
2417 if (WARN_ON(!q) ||
2418 WARN_ON(!q->ops) ||
2419 WARN_ON(!q->mem_ops) ||
2420 WARN_ON(!q->type) ||
2421 WARN_ON(!q->io_modes) ||
2422 WARN_ON(!q->ops->queue_setup) ||
2423 WARN_ON(!q->ops->buf_queue))
2424 return -EINVAL;
2425
2426 if (WARN_ON(q->requires_requests && !q->supports_requests))
2427 return -EINVAL;
2428
2429 /*
2430 * This combination is not allowed since a non-zero value of
2431 * q->min_buffers_needed can cause vb2_core_qbuf() to fail if
2432 * it has to call start_streaming(), and the Request API expects
2433 * that queueing a request (and thus queueing a buffer contained
2434 * in that request) will always succeed. There is no method of
2435 * propagating an error back to userspace.
2436 */
2437 if (WARN_ON(q->supports_requests && q->min_buffers_needed))
2438 return -EINVAL;
2439
2440 INIT_LIST_HEAD(&q->queued_list);
2441 INIT_LIST_HEAD(&q->done_list);
2442 spin_lock_init(&q->done_lock);
2443 mutex_init(&q->mmap_lock);
2444 init_waitqueue_head(&q->done_wq);
2445
2446 q->memory = VB2_MEMORY_UNKNOWN;
2447
2448 if (q->buf_struct_size == 0)
2449 q->buf_struct_size = sizeof(struct vb2_buffer);
2450
2451 if (q->bidirectional)
2452 q->dma_dir = DMA_BIDIRECTIONAL;
2453 else
2454 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2455
2456 if (q->name[0] == '\0')
2457 snprintf(q->name, sizeof(q->name), "%s-%p",
2458 q->is_output ? "out" : "cap", q);
2459
2460 return 0;
2461 }
2462 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2463
2464 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2465 static int __vb2_cleanup_fileio(struct vb2_queue *q);
vb2_core_queue_release(struct vb2_queue * q)2466 void vb2_core_queue_release(struct vb2_queue *q)
2467 {
2468 __vb2_cleanup_fileio(q);
2469 __vb2_queue_cancel(q);
2470 mutex_lock(&q->mmap_lock);
2471 __vb2_queue_free(q, q->num_buffers);
2472 mutex_unlock(&q->mmap_lock);
2473 }
2474 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2475
vb2_core_poll(struct vb2_queue * q,struct file * file,poll_table * wait)2476 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2477 poll_table *wait)
2478 {
2479 __poll_t req_events = poll_requested_events(wait);
2480 struct vb2_buffer *vb = NULL;
2481 unsigned long flags;
2482
2483 /*
2484 * poll_wait() MUST be called on the first invocation on all the
2485 * potential queues of interest, even if we are not interested in their
2486 * events during this first call. Failure to do so will result in
2487 * queue's events to be ignored because the poll_table won't be capable
2488 * of adding new wait queues thereafter.
2489 */
2490 poll_wait(file, &q->done_wq, wait);
2491
2492 if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
2493 return 0;
2494 if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
2495 return 0;
2496
2497 /*
2498 * Start file I/O emulator only if streaming API has not been used yet.
2499 */
2500 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2501 if (!q->is_output && (q->io_modes & VB2_READ) &&
2502 (req_events & (EPOLLIN | EPOLLRDNORM))) {
2503 if (__vb2_init_fileio(q, 1))
2504 return EPOLLERR;
2505 }
2506 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2507 (req_events & (EPOLLOUT | EPOLLWRNORM))) {
2508 if (__vb2_init_fileio(q, 0))
2509 return EPOLLERR;
2510 /*
2511 * Write to OUTPUT queue can be done immediately.
2512 */
2513 return EPOLLOUT | EPOLLWRNORM;
2514 }
2515 }
2516
2517 /*
2518 * There is nothing to wait for if the queue isn't streaming, or if the
2519 * error flag is set.
2520 */
2521 if (!vb2_is_streaming(q) || q->error)
2522 return EPOLLERR;
2523
2524 /*
2525 * If this quirk is set and QBUF hasn't been called yet then
2526 * return EPOLLERR as well. This only affects capture queues, output
2527 * queues will always initialize waiting_for_buffers to false.
2528 * This quirk is set by V4L2 for backwards compatibility reasons.
2529 */
2530 if (q->quirk_poll_must_check_waiting_for_buffers &&
2531 q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
2532 return EPOLLERR;
2533
2534 /*
2535 * For output streams you can call write() as long as there are fewer
2536 * buffers queued than there are buffers available.
2537 */
2538 if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2539 return EPOLLOUT | EPOLLWRNORM;
2540
2541 if (list_empty(&q->done_list)) {
2542 /*
2543 * If the last buffer was dequeued from a capture queue,
2544 * return immediately. DQBUF will return -EPIPE.
2545 */
2546 if (q->last_buffer_dequeued)
2547 return EPOLLIN | EPOLLRDNORM;
2548 }
2549
2550 /*
2551 * Take first buffer available for dequeuing.
2552 */
2553 spin_lock_irqsave(&q->done_lock, flags);
2554 if (!list_empty(&q->done_list))
2555 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2556 done_entry);
2557 spin_unlock_irqrestore(&q->done_lock, flags);
2558
2559 if (vb && (vb->state == VB2_BUF_STATE_DONE
2560 || vb->state == VB2_BUF_STATE_ERROR)) {
2561 return (q->is_output) ?
2562 EPOLLOUT | EPOLLWRNORM :
2563 EPOLLIN | EPOLLRDNORM;
2564 }
2565 return 0;
2566 }
2567 EXPORT_SYMBOL_GPL(vb2_core_poll);
2568
2569 /*
2570 * struct vb2_fileio_buf - buffer context used by file io emulator
2571 *
2572 * vb2 provides a compatibility layer and emulator of file io (read and
2573 * write) calls on top of streaming API. This structure is used for
2574 * tracking context related to the buffers.
2575 */
2576 struct vb2_fileio_buf {
2577 void *vaddr;
2578 unsigned int size;
2579 unsigned int pos;
2580 unsigned int queued:1;
2581 };
2582
2583 /*
2584 * struct vb2_fileio_data - queue context used by file io emulator
2585 *
2586 * @cur_index: the index of the buffer currently being read from or
2587 * written to. If equal to q->num_buffers then a new buffer
2588 * must be dequeued.
2589 * @initial_index: in the read() case all buffers are queued up immediately
2590 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2591 * buffers. However, in the write() case no buffers are initially
2592 * queued, instead whenever a buffer is full it is queued up by
2593 * __vb2_perform_fileio(). Only once all available buffers have
2594 * been queued up will __vb2_perform_fileio() start to dequeue
2595 * buffers. This means that initially __vb2_perform_fileio()
2596 * needs to know what buffer index to use when it is queuing up
2597 * the buffers for the first time. That initial index is stored
2598 * in this field. Once it is equal to q->num_buffers all
2599 * available buffers have been queued and __vb2_perform_fileio()
2600 * should start the normal dequeue/queue cycle.
2601 *
2602 * vb2 provides a compatibility layer and emulator of file io (read and
2603 * write) calls on top of streaming API. For proper operation it required
2604 * this structure to save the driver state between each call of the read
2605 * or write function.
2606 */
2607 struct vb2_fileio_data {
2608 unsigned int count;
2609 unsigned int type;
2610 unsigned int memory;
2611 struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2612 unsigned int cur_index;
2613 unsigned int initial_index;
2614 unsigned int q_count;
2615 unsigned int dq_count;
2616 unsigned read_once:1;
2617 unsigned write_immediately:1;
2618 };
2619
2620 /*
2621 * __vb2_init_fileio() - initialize file io emulator
2622 * @q: videobuf2 queue
2623 * @read: mode selector (1 means read, 0 means write)
2624 */
__vb2_init_fileio(struct vb2_queue * q,int read)2625 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2626 {
2627 struct vb2_fileio_data *fileio;
2628 int i, ret;
2629 unsigned int count = 0;
2630
2631 /*
2632 * Sanity check
2633 */
2634 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2635 (!read && !(q->io_modes & VB2_WRITE))))
2636 return -EINVAL;
2637
2638 /*
2639 * Check if device supports mapping buffers to kernel virtual space.
2640 */
2641 if (!q->mem_ops->vaddr)
2642 return -EBUSY;
2643
2644 /*
2645 * Check if streaming api has not been already activated.
2646 */
2647 if (q->streaming || q->num_buffers > 0)
2648 return -EBUSY;
2649
2650 /*
2651 * Start with count 1, driver can increase it in queue_setup()
2652 */
2653 count = 1;
2654
2655 dprintk(q, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2656 (read) ? "read" : "write", count, q->fileio_read_once,
2657 q->fileio_write_immediately);
2658
2659 fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2660 if (fileio == NULL)
2661 return -ENOMEM;
2662
2663 fileio->read_once = q->fileio_read_once;
2664 fileio->write_immediately = q->fileio_write_immediately;
2665
2666 /*
2667 * Request buffers and use MMAP type to force driver
2668 * to allocate buffers by itself.
2669 */
2670 fileio->count = count;
2671 fileio->memory = VB2_MEMORY_MMAP;
2672 fileio->type = q->type;
2673 q->fileio = fileio;
2674 ret = vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2675 if (ret)
2676 goto err_kfree;
2677
2678 /*
2679 * Check if plane_count is correct
2680 * (multiplane buffers are not supported).
2681 */
2682 if (q->bufs[0]->num_planes != 1) {
2683 ret = -EBUSY;
2684 goto err_reqbufs;
2685 }
2686
2687 /*
2688 * Get kernel address of each buffer.
2689 */
2690 for (i = 0; i < q->num_buffers; i++) {
2691 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2692 if (fileio->bufs[i].vaddr == NULL) {
2693 ret = -EINVAL;
2694 goto err_reqbufs;
2695 }
2696 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2697 }
2698
2699 /*
2700 * Read mode requires pre queuing of all buffers.
2701 */
2702 if (read) {
2703 /*
2704 * Queue all buffers.
2705 */
2706 for (i = 0; i < q->num_buffers; i++) {
2707 ret = vb2_core_qbuf(q, i, NULL, NULL);
2708 if (ret)
2709 goto err_reqbufs;
2710 fileio->bufs[i].queued = 1;
2711 }
2712 /*
2713 * All buffers have been queued, so mark that by setting
2714 * initial_index to q->num_buffers
2715 */
2716 fileio->initial_index = q->num_buffers;
2717 fileio->cur_index = q->num_buffers;
2718 }
2719
2720 /*
2721 * Start streaming.
2722 */
2723 ret = vb2_core_streamon(q, q->type);
2724 if (ret)
2725 goto err_reqbufs;
2726
2727 return ret;
2728
2729 err_reqbufs:
2730 fileio->count = 0;
2731 vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2732
2733 err_kfree:
2734 q->fileio = NULL;
2735 kfree(fileio);
2736 return ret;
2737 }
2738
2739 /*
2740 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2741 * @q: videobuf2 queue
2742 */
__vb2_cleanup_fileio(struct vb2_queue * q)2743 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2744 {
2745 struct vb2_fileio_data *fileio = q->fileio;
2746
2747 if (fileio) {
2748 vb2_core_streamoff(q, q->type);
2749 q->fileio = NULL;
2750 fileio->count = 0;
2751 vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2752 kfree(fileio);
2753 dprintk(q, 3, "file io emulator closed\n");
2754 }
2755 return 0;
2756 }
2757
2758 /*
2759 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2760 * @q: videobuf2 queue
2761 * @data: pointed to target userspace buffer
2762 * @count: number of bytes to read or write
2763 * @ppos: file handle position tracking pointer
2764 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2765 * @read: access mode selector (1 means read, 0 means write)
2766 */
__vb2_perform_fileio(struct vb2_queue * q,char __user * data,size_t count,loff_t * ppos,int nonblock,int read)2767 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2768 loff_t *ppos, int nonblock, int read)
2769 {
2770 struct vb2_fileio_data *fileio;
2771 struct vb2_fileio_buf *buf;
2772 bool is_multiplanar = q->is_multiplanar;
2773 /*
2774 * When using write() to write data to an output video node the vb2 core
2775 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2776 * else is able to provide this information with the write() operation.
2777 */
2778 bool copy_timestamp = !read && q->copy_timestamp;
2779 unsigned index;
2780 int ret;
2781
2782 dprintk(q, 3, "mode %s, offset %ld, count %zd, %sblocking\n",
2783 read ? "read" : "write", (long)*ppos, count,
2784 nonblock ? "non" : "");
2785
2786 if (!data)
2787 return -EINVAL;
2788
2789 if (q->waiting_in_dqbuf) {
2790 dprintk(q, 3, "another dup()ped fd is %s\n",
2791 read ? "reading" : "writing");
2792 return -EBUSY;
2793 }
2794
2795 /*
2796 * Initialize emulator on first call.
2797 */
2798 if (!vb2_fileio_is_active(q)) {
2799 ret = __vb2_init_fileio(q, read);
2800 dprintk(q, 3, "vb2_init_fileio result: %d\n", ret);
2801 if (ret)
2802 return ret;
2803 }
2804 fileio = q->fileio;
2805
2806 /*
2807 * Check if we need to dequeue the buffer.
2808 */
2809 index = fileio->cur_index;
2810 if (index >= q->num_buffers) {
2811 struct vb2_buffer *b;
2812
2813 /*
2814 * Call vb2_dqbuf to get buffer back.
2815 */
2816 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2817 dprintk(q, 5, "vb2_dqbuf result: %d\n", ret);
2818 if (ret)
2819 return ret;
2820 fileio->dq_count += 1;
2821
2822 fileio->cur_index = index;
2823 buf = &fileio->bufs[index];
2824 b = q->bufs[index];
2825
2826 /*
2827 * Get number of bytes filled by the driver
2828 */
2829 buf->pos = 0;
2830 buf->queued = 0;
2831 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2832 : vb2_plane_size(q->bufs[index], 0);
2833 /* Compensate for data_offset on read in the multiplanar case. */
2834 if (is_multiplanar && read &&
2835 b->planes[0].data_offset < buf->size) {
2836 buf->pos = b->planes[0].data_offset;
2837 buf->size -= buf->pos;
2838 }
2839 } else {
2840 buf = &fileio->bufs[index];
2841 }
2842
2843 /*
2844 * Limit count on last few bytes of the buffer.
2845 */
2846 if (buf->pos + count > buf->size) {
2847 count = buf->size - buf->pos;
2848 dprintk(q, 5, "reducing read count: %zd\n", count);
2849 }
2850
2851 /*
2852 * Transfer data to userspace.
2853 */
2854 dprintk(q, 3, "copying %zd bytes - buffer %d, offset %u\n",
2855 count, index, buf->pos);
2856 if (read)
2857 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2858 else
2859 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2860 if (ret) {
2861 dprintk(q, 3, "error copying data\n");
2862 return -EFAULT;
2863 }
2864
2865 /*
2866 * Update counters.
2867 */
2868 buf->pos += count;
2869 *ppos += count;
2870
2871 /*
2872 * Queue next buffer if required.
2873 */
2874 if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2875 struct vb2_buffer *b = q->bufs[index];
2876
2877 /*
2878 * Check if this is the last buffer to read.
2879 */
2880 if (read && fileio->read_once && fileio->dq_count == 1) {
2881 dprintk(q, 3, "read limit reached\n");
2882 return __vb2_cleanup_fileio(q);
2883 }
2884
2885 /*
2886 * Call vb2_qbuf and give buffer to the driver.
2887 */
2888 b->planes[0].bytesused = buf->pos;
2889
2890 if (copy_timestamp)
2891 b->timestamp = ktime_get_ns();
2892 ret = vb2_core_qbuf(q, index, NULL, NULL);
2893 dprintk(q, 5, "vb2_dbuf result: %d\n", ret);
2894 if (ret)
2895 return ret;
2896
2897 /*
2898 * Buffer has been queued, update the status
2899 */
2900 buf->pos = 0;
2901 buf->queued = 1;
2902 buf->size = vb2_plane_size(q->bufs[index], 0);
2903 fileio->q_count += 1;
2904 /*
2905 * If we are queuing up buffers for the first time, then
2906 * increase initial_index by one.
2907 */
2908 if (fileio->initial_index < q->num_buffers)
2909 fileio->initial_index++;
2910 /*
2911 * The next buffer to use is either a buffer that's going to be
2912 * queued for the first time (initial_index < q->num_buffers)
2913 * or it is equal to q->num_buffers, meaning that the next
2914 * time we need to dequeue a buffer since we've now queued up
2915 * all the 'first time' buffers.
2916 */
2917 fileio->cur_index = fileio->initial_index;
2918 }
2919
2920 /*
2921 * Return proper number of bytes processed.
2922 */
2923 if (ret == 0)
2924 ret = count;
2925 return ret;
2926 }
2927
vb2_read(struct vb2_queue * q,char __user * data,size_t count,loff_t * ppos,int nonblocking)2928 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2929 loff_t *ppos, int nonblocking)
2930 {
2931 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2932 }
2933 EXPORT_SYMBOL_GPL(vb2_read);
2934
vb2_write(struct vb2_queue * q,const char __user * data,size_t count,loff_t * ppos,int nonblocking)2935 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2936 loff_t *ppos, int nonblocking)
2937 {
2938 return __vb2_perform_fileio(q, (char __user *) data, count,
2939 ppos, nonblocking, 0);
2940 }
2941 EXPORT_SYMBOL_GPL(vb2_write);
2942
2943 struct vb2_threadio_data {
2944 struct task_struct *thread;
2945 vb2_thread_fnc fnc;
2946 void *priv;
2947 bool stop;
2948 };
2949
vb2_thread(void * data)2950 static int vb2_thread(void *data)
2951 {
2952 struct vb2_queue *q = data;
2953 struct vb2_threadio_data *threadio = q->threadio;
2954 bool copy_timestamp = false;
2955 unsigned prequeue = 0;
2956 unsigned index = 0;
2957 int ret = 0;
2958
2959 if (q->is_output) {
2960 prequeue = q->num_buffers;
2961 copy_timestamp = q->copy_timestamp;
2962 }
2963
2964 set_freezable();
2965
2966 for (;;) {
2967 struct vb2_buffer *vb;
2968
2969 /*
2970 * Call vb2_dqbuf to get buffer back.
2971 */
2972 if (prequeue) {
2973 vb = q->bufs[index++];
2974 prequeue--;
2975 } else {
2976 call_void_qop(q, wait_finish, q);
2977 if (!threadio->stop)
2978 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2979 call_void_qop(q, wait_prepare, q);
2980 dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
2981 if (!ret)
2982 vb = q->bufs[index];
2983 }
2984 if (ret || threadio->stop)
2985 break;
2986 try_to_freeze();
2987
2988 if (vb->state != VB2_BUF_STATE_ERROR)
2989 if (threadio->fnc(vb, threadio->priv))
2990 break;
2991 call_void_qop(q, wait_finish, q);
2992 if (copy_timestamp)
2993 vb->timestamp = ktime_get_ns();
2994 if (!threadio->stop)
2995 ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
2996 call_void_qop(q, wait_prepare, q);
2997 if (ret || threadio->stop)
2998 break;
2999 }
3000
3001 /* Hmm, linux becomes *very* unhappy without this ... */
3002 while (!kthread_should_stop()) {
3003 set_current_state(TASK_INTERRUPTIBLE);
3004 schedule();
3005 }
3006 return 0;
3007 }
3008
3009 /*
3010 * This function should not be used for anything else but the videobuf2-dvb
3011 * support. If you think you have another good use-case for this, then please
3012 * contact the linux-media mailinglist first.
3013 */
vb2_thread_start(struct vb2_queue * q,vb2_thread_fnc fnc,void * priv,const char * thread_name)3014 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
3015 const char *thread_name)
3016 {
3017 struct vb2_threadio_data *threadio;
3018 int ret = 0;
3019
3020 if (q->threadio)
3021 return -EBUSY;
3022 if (vb2_is_busy(q))
3023 return -EBUSY;
3024 if (WARN_ON(q->fileio))
3025 return -EBUSY;
3026
3027 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
3028 if (threadio == NULL)
3029 return -ENOMEM;
3030 threadio->fnc = fnc;
3031 threadio->priv = priv;
3032
3033 ret = __vb2_init_fileio(q, !q->is_output);
3034 dprintk(q, 3, "file io: vb2_init_fileio result: %d\n", ret);
3035 if (ret)
3036 goto nomem;
3037 q->threadio = threadio;
3038 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3039 if (IS_ERR(threadio->thread)) {
3040 ret = PTR_ERR(threadio->thread);
3041 threadio->thread = NULL;
3042 goto nothread;
3043 }
3044 return 0;
3045
3046 nothread:
3047 __vb2_cleanup_fileio(q);
3048 nomem:
3049 kfree(threadio);
3050 return ret;
3051 }
3052 EXPORT_SYMBOL_GPL(vb2_thread_start);
3053
vb2_thread_stop(struct vb2_queue * q)3054 int vb2_thread_stop(struct vb2_queue *q)
3055 {
3056 struct vb2_threadio_data *threadio = q->threadio;
3057 int err;
3058
3059 if (threadio == NULL)
3060 return 0;
3061 threadio->stop = true;
3062 /* Wake up all pending sleeps in the thread */
3063 vb2_queue_error(q);
3064 err = kthread_stop(threadio->thread);
3065 __vb2_cleanup_fileio(q);
3066 threadio->thread = NULL;
3067 kfree(threadio);
3068 q->threadio = NULL;
3069 return err;
3070 }
3071 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3072
3073 MODULE_DESCRIPTION("Media buffer core framework");
3074 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3075 MODULE_LICENSE("GPL");
3076 MODULE_IMPORT_NS(DMA_BUF);
3077