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 
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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 
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 videobuf 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  */
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 videobuf 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  */
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  */
505 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
506 {
507 	unsigned int buffer;
508 
509 	/*
510 	 * Sanity check: when preparing a buffer the queue lock is released for
511 	 * a short while (see __buf_prepare for the details), which would allow
512 	 * a race with a reqbufs which can call this function. Removing the
513 	 * buffers from underneath __buf_prepare is obviously a bad idea, so we
514 	 * check if any of the buffers is in the state PREPARING, and if so we
515 	 * just return -EAGAIN.
516 	 */
517 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
518 	     ++buffer) {
519 		if (q->bufs[buffer] == NULL)
520 			continue;
521 		if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
522 			dprintk(q, 1, "preparing buffers, cannot free\n");
523 			return -EAGAIN;
524 		}
525 	}
526 
527 	/* Call driver-provided cleanup function for each buffer, if provided */
528 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
529 	     ++buffer) {
530 		struct vb2_buffer *vb = q->bufs[buffer];
531 
532 		if (vb && vb->planes[0].mem_priv)
533 			call_void_vb_qop(vb, buf_cleanup, vb);
534 	}
535 
536 	/* Release video buffer memory */
537 	__vb2_free_mem(q, buffers);
538 
539 #ifdef CONFIG_VIDEO_ADV_DEBUG
540 	/*
541 	 * Check that all the calls were balances during the life-time of this
542 	 * queue. If not (or if the debug level is 1 or up), then dump the
543 	 * counters to the kernel log.
544 	 */
545 	if (q->num_buffers) {
546 		bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
547 				  q->cnt_wait_prepare != q->cnt_wait_finish;
548 
549 		if (unbalanced || debug) {
550 			pr_info("counters for queue %p:%s\n", q,
551 				unbalanced ? " UNBALANCED!" : "");
552 			pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
553 				q->cnt_queue_setup, q->cnt_start_streaming,
554 				q->cnt_stop_streaming);
555 			pr_info("     wait_prepare: %u wait_finish: %u\n",
556 				q->cnt_wait_prepare, q->cnt_wait_finish);
557 		}
558 		q->cnt_queue_setup = 0;
559 		q->cnt_wait_prepare = 0;
560 		q->cnt_wait_finish = 0;
561 		q->cnt_start_streaming = 0;
562 		q->cnt_stop_streaming = 0;
563 	}
564 	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
565 		struct vb2_buffer *vb = q->bufs[buffer];
566 		bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
567 				  vb->cnt_mem_prepare != vb->cnt_mem_finish ||
568 				  vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
569 				  vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
570 				  vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
571 				  vb->cnt_buf_queue != vb->cnt_buf_done ||
572 				  vb->cnt_buf_prepare != vb->cnt_buf_finish ||
573 				  vb->cnt_buf_init != vb->cnt_buf_cleanup;
574 
575 		if (unbalanced || debug) {
576 			pr_info("   counters for queue %p, buffer %d:%s\n",
577 				q, buffer, unbalanced ? " UNBALANCED!" : "");
578 			pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
579 				vb->cnt_buf_init, vb->cnt_buf_cleanup,
580 				vb->cnt_buf_prepare, vb->cnt_buf_finish);
581 			pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
582 				vb->cnt_buf_out_validate, vb->cnt_buf_queue,
583 				vb->cnt_buf_done, vb->cnt_buf_request_complete);
584 			pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
585 				vb->cnt_mem_alloc, vb->cnt_mem_put,
586 				vb->cnt_mem_prepare, vb->cnt_mem_finish,
587 				vb->cnt_mem_mmap);
588 			pr_info("     get_userptr: %u put_userptr: %u\n",
589 				vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
590 			pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
591 				vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
592 				vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
593 			pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
594 				vb->cnt_mem_get_dmabuf,
595 				vb->cnt_mem_num_users,
596 				vb->cnt_mem_vaddr,
597 				vb->cnt_mem_cookie);
598 		}
599 	}
600 #endif
601 
602 	/* Free videobuf buffers */
603 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
604 	     ++buffer) {
605 		kfree(q->bufs[buffer]);
606 		q->bufs[buffer] = NULL;
607 	}
608 
609 	q->num_buffers -= buffers;
610 	if (!q->num_buffers) {
611 		q->memory = VB2_MEMORY_UNKNOWN;
612 		INIT_LIST_HEAD(&q->queued_list);
613 	}
614 	return 0;
615 }
616 
617 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
618 {
619 	unsigned int plane;
620 	for (plane = 0; plane < vb->num_planes; ++plane) {
621 		void *mem_priv = vb->planes[plane].mem_priv;
622 		/*
623 		 * If num_users() has not been provided, call_memop
624 		 * will return 0, apparently nobody cares about this
625 		 * case anyway. If num_users() returns more than 1,
626 		 * we are not the only user of the plane's memory.
627 		 */
628 		if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
629 			return true;
630 	}
631 	return false;
632 }
633 EXPORT_SYMBOL(vb2_buffer_in_use);
634 
635 /*
636  * __buffers_in_use() - return true if any buffers on the queue are in use and
637  * the queue cannot be freed (by the means of REQBUFS(0)) call
638  */
639 static bool __buffers_in_use(struct vb2_queue *q)
640 {
641 	unsigned int buffer;
642 	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
643 		if (vb2_buffer_in_use(q, q->bufs[buffer]))
644 			return true;
645 	}
646 	return false;
647 }
648 
649 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
650 {
651 	call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
652 }
653 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
654 
655 /*
656  * __verify_userptr_ops() - verify that all memory operations required for
657  * USERPTR queue type have been provided
658  */
659 static int __verify_userptr_ops(struct vb2_queue *q)
660 {
661 	if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
662 	    !q->mem_ops->put_userptr)
663 		return -EINVAL;
664 
665 	return 0;
666 }
667 
668 /*
669  * __verify_mmap_ops() - verify that all memory operations required for
670  * MMAP queue type have been provided
671  */
672 static int __verify_mmap_ops(struct vb2_queue *q)
673 {
674 	if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
675 	    !q->mem_ops->put || !q->mem_ops->mmap)
676 		return -EINVAL;
677 
678 	return 0;
679 }
680 
681 /*
682  * __verify_dmabuf_ops() - verify that all memory operations required for
683  * DMABUF queue type have been provided
684  */
685 static int __verify_dmabuf_ops(struct vb2_queue *q)
686 {
687 	if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
688 	    !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
689 	    !q->mem_ops->unmap_dmabuf)
690 		return -EINVAL;
691 
692 	return 0;
693 }
694 
695 int vb2_verify_memory_type(struct vb2_queue *q,
696 		enum vb2_memory memory, unsigned int type)
697 {
698 	if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
699 	    memory != VB2_MEMORY_DMABUF) {
700 		dprintk(q, 1, "unsupported memory type\n");
701 		return -EINVAL;
702 	}
703 
704 	if (type != q->type) {
705 		dprintk(q, 1, "requested type is incorrect\n");
706 		return -EINVAL;
707 	}
708 
709 	/*
710 	 * Make sure all the required memory ops for given memory type
711 	 * are available.
712 	 */
713 	if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
714 		dprintk(q, 1, "MMAP for current setup unsupported\n");
715 		return -EINVAL;
716 	}
717 
718 	if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
719 		dprintk(q, 1, "USERPTR for current setup unsupported\n");
720 		return -EINVAL;
721 	}
722 
723 	if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
724 		dprintk(q, 1, "DMABUF for current setup unsupported\n");
725 		return -EINVAL;
726 	}
727 
728 	/*
729 	 * Place the busy tests at the end: -EBUSY can be ignored when
730 	 * create_bufs is called with count == 0, but count == 0 should still
731 	 * do the memory and type validation.
732 	 */
733 	if (vb2_fileio_is_active(q)) {
734 		dprintk(q, 1, "file io in progress\n");
735 		return -EBUSY;
736 	}
737 	return 0;
738 }
739 EXPORT_SYMBOL(vb2_verify_memory_type);
740 
741 static void set_queue_coherency(struct vb2_queue *q, bool non_coherent_mem)
742 {
743 	q->non_coherent_mem = 0;
744 
745 	if (!vb2_queue_allows_cache_hints(q))
746 		return;
747 	q->non_coherent_mem = non_coherent_mem;
748 }
749 
750 static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
751 {
752 	if (non_coherent_mem != q->non_coherent_mem) {
753 		dprintk(q, 1, "memory coherency model mismatch\n");
754 		return false;
755 	}
756 	return true;
757 }
758 
759 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
760 		     unsigned int flags, unsigned int *count)
761 {
762 	unsigned int num_buffers, allocated_buffers, num_planes = 0;
763 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
764 	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
765 	unsigned int i;
766 	int ret;
767 
768 	if (q->streaming) {
769 		dprintk(q, 1, "streaming active\n");
770 		return -EBUSY;
771 	}
772 
773 	if (q->waiting_in_dqbuf && *count) {
774 		dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
775 		return -EBUSY;
776 	}
777 
778 	if (*count == 0 || q->num_buffers != 0 ||
779 	    (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) ||
780 	    !verify_coherency_flags(q, non_coherent_mem)) {
781 		/*
782 		 * We already have buffers allocated, so first check if they
783 		 * are not in use and can be freed.
784 		 */
785 		mutex_lock(&q->mmap_lock);
786 		if (debug && q->memory == VB2_MEMORY_MMAP &&
787 		    __buffers_in_use(q))
788 			dprintk(q, 1, "memory in use, orphaning buffers\n");
789 
790 		/*
791 		 * Call queue_cancel to clean up any buffers in the
792 		 * QUEUED state which is possible if buffers were prepared or
793 		 * queued without ever calling STREAMON.
794 		 */
795 		__vb2_queue_cancel(q);
796 		ret = __vb2_queue_free(q, q->num_buffers);
797 		mutex_unlock(&q->mmap_lock);
798 		if (ret)
799 			return ret;
800 
801 		/*
802 		 * In case of REQBUFS(0) return immediately without calling
803 		 * driver's queue_setup() callback and allocating resources.
804 		 */
805 		if (*count == 0)
806 			return 0;
807 	}
808 
809 	/*
810 	 * Make sure the requested values and current defaults are sane.
811 	 */
812 	WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
813 	num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
814 	num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
815 	memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
816 	q->memory = memory;
817 	set_queue_coherency(q, non_coherent_mem);
818 
819 	/*
820 	 * Ask the driver how many buffers and planes per buffer it requires.
821 	 * Driver also sets the size and allocator context for each plane.
822 	 */
823 	ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
824 		       plane_sizes, q->alloc_devs);
825 	if (ret)
826 		return ret;
827 
828 	/* Check that driver has set sane values */
829 	if (WARN_ON(!num_planes))
830 		return -EINVAL;
831 
832 	for (i = 0; i < num_planes; i++)
833 		if (WARN_ON(!plane_sizes[i]))
834 			return -EINVAL;
835 
836 	/* Finally, allocate buffers and video memory */
837 	allocated_buffers =
838 		__vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
839 	if (allocated_buffers == 0) {
840 		dprintk(q, 1, "memory allocation failed\n");
841 		return -ENOMEM;
842 	}
843 
844 	/*
845 	 * There is no point in continuing if we can't allocate the minimum
846 	 * number of buffers needed by this vb2_queue.
847 	 */
848 	if (allocated_buffers < q->min_buffers_needed)
849 		ret = -ENOMEM;
850 
851 	/*
852 	 * Check if driver can handle the allocated number of buffers.
853 	 */
854 	if (!ret && allocated_buffers < num_buffers) {
855 		num_buffers = allocated_buffers;
856 		/*
857 		 * num_planes is set by the previous queue_setup(), but since it
858 		 * signals to queue_setup() whether it is called from create_bufs()
859 		 * vs reqbufs() we zero it here to signal that queue_setup() is
860 		 * called for the reqbufs() case.
861 		 */
862 		num_planes = 0;
863 
864 		ret = call_qop(q, queue_setup, q, &num_buffers,
865 			       &num_planes, plane_sizes, q->alloc_devs);
866 
867 		if (!ret && allocated_buffers < num_buffers)
868 			ret = -ENOMEM;
869 
870 		/*
871 		 * Either the driver has accepted a smaller number of buffers,
872 		 * or .queue_setup() returned an error
873 		 */
874 	}
875 
876 	mutex_lock(&q->mmap_lock);
877 	q->num_buffers = allocated_buffers;
878 
879 	if (ret < 0) {
880 		/*
881 		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
882 		 * from q->num_buffers.
883 		 */
884 		__vb2_queue_free(q, allocated_buffers);
885 		mutex_unlock(&q->mmap_lock);
886 		return ret;
887 	}
888 	mutex_unlock(&q->mmap_lock);
889 
890 	/*
891 	 * Return the number of successfully allocated buffers
892 	 * to the userspace.
893 	 */
894 	*count = allocated_buffers;
895 	q->waiting_for_buffers = !q->is_output;
896 
897 	return 0;
898 }
899 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
900 
901 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
902 			 unsigned int flags, unsigned int *count,
903 			 unsigned int requested_planes,
904 			 const unsigned int requested_sizes[])
905 {
906 	unsigned int num_planes = 0, num_buffers, allocated_buffers;
907 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
908 	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
909 	int ret;
910 
911 	if (q->num_buffers == VB2_MAX_FRAME) {
912 		dprintk(q, 1, "maximum number of buffers already allocated\n");
913 		return -ENOBUFS;
914 	}
915 
916 	if (!q->num_buffers) {
917 		if (q->waiting_in_dqbuf && *count) {
918 			dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
919 			return -EBUSY;
920 		}
921 		memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
922 		q->memory = memory;
923 		q->waiting_for_buffers = !q->is_output;
924 		set_queue_coherency(q, non_coherent_mem);
925 	} else {
926 		if (q->memory != memory) {
927 			dprintk(q, 1, "memory model mismatch\n");
928 			return -EINVAL;
929 		}
930 		if (!verify_coherency_flags(q, non_coherent_mem))
931 			return -EINVAL;
932 	}
933 
934 	num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
935 
936 	if (requested_planes && requested_sizes) {
937 		num_planes = requested_planes;
938 		memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
939 	}
940 
941 	/*
942 	 * Ask the driver, whether the requested number of buffers, planes per
943 	 * buffer and their sizes are acceptable
944 	 */
945 	ret = call_qop(q, queue_setup, q, &num_buffers,
946 		       &num_planes, plane_sizes, q->alloc_devs);
947 	if (ret)
948 		return ret;
949 
950 	/* Finally, allocate buffers and video memory */
951 	allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
952 				num_planes, plane_sizes);
953 	if (allocated_buffers == 0) {
954 		dprintk(q, 1, "memory allocation failed\n");
955 		return -ENOMEM;
956 	}
957 
958 	/*
959 	 * Check if driver can handle the so far allocated number of buffers.
960 	 */
961 	if (allocated_buffers < num_buffers) {
962 		num_buffers = allocated_buffers;
963 
964 		/*
965 		 * q->num_buffers contains the total number of buffers, that the
966 		 * queue driver has set up
967 		 */
968 		ret = call_qop(q, queue_setup, q, &num_buffers,
969 			       &num_planes, plane_sizes, q->alloc_devs);
970 
971 		if (!ret && allocated_buffers < num_buffers)
972 			ret = -ENOMEM;
973 
974 		/*
975 		 * Either the driver has accepted a smaller number of buffers,
976 		 * or .queue_setup() returned an error
977 		 */
978 	}
979 
980 	mutex_lock(&q->mmap_lock);
981 	q->num_buffers += allocated_buffers;
982 
983 	if (ret < 0) {
984 		/*
985 		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
986 		 * from q->num_buffers.
987 		 */
988 		__vb2_queue_free(q, allocated_buffers);
989 		mutex_unlock(&q->mmap_lock);
990 		return -ENOMEM;
991 	}
992 	mutex_unlock(&q->mmap_lock);
993 
994 	/*
995 	 * Return the number of successfully allocated buffers
996 	 * to the userspace.
997 	 */
998 	*count = allocated_buffers;
999 
1000 	return 0;
1001 }
1002 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
1003 
1004 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
1005 {
1006 	if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1007 		return NULL;
1008 
1009 	return call_ptr_memop(vaddr, vb, vb->planes[plane_no].mem_priv);
1010 
1011 }
1012 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
1013 
1014 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
1015 {
1016 	if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
1017 		return NULL;
1018 
1019 	return call_ptr_memop(cookie, vb, vb->planes[plane_no].mem_priv);
1020 }
1021 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
1022 
1023 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
1024 {
1025 	struct vb2_queue *q = vb->vb2_queue;
1026 	unsigned long flags;
1027 
1028 	if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
1029 		return;
1030 
1031 	if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1032 		    state != VB2_BUF_STATE_ERROR &&
1033 		    state != VB2_BUF_STATE_QUEUED))
1034 		state = VB2_BUF_STATE_ERROR;
1035 
1036 #ifdef CONFIG_VIDEO_ADV_DEBUG
1037 	/*
1038 	 * Although this is not a callback, it still does have to balance
1039 	 * with the buf_queue op. So update this counter manually.
1040 	 */
1041 	vb->cnt_buf_done++;
1042 #endif
1043 	dprintk(q, 4, "done processing on buffer %d, state: %s\n",
1044 		vb->index, vb2_state_name(state));
1045 
1046 	if (state != VB2_BUF_STATE_QUEUED)
1047 		__vb2_buf_mem_finish(vb);
1048 
1049 	spin_lock_irqsave(&q->done_lock, flags);
1050 	if (state == VB2_BUF_STATE_QUEUED) {
1051 		vb->state = VB2_BUF_STATE_QUEUED;
1052 	} else {
1053 		/* Add the buffer to the done buffers list */
1054 		list_add_tail(&vb->done_entry, &q->done_list);
1055 		vb->state = state;
1056 	}
1057 	atomic_dec(&q->owned_by_drv_count);
1058 
1059 	if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
1060 		media_request_object_unbind(&vb->req_obj);
1061 		media_request_object_put(&vb->req_obj);
1062 	}
1063 
1064 	spin_unlock_irqrestore(&q->done_lock, flags);
1065 
1066 	trace_vb2_buf_done(q, vb);
1067 
1068 	switch (state) {
1069 	case VB2_BUF_STATE_QUEUED:
1070 		return;
1071 	default:
1072 		/* Inform any processes that may be waiting for buffers */
1073 		wake_up(&q->done_wq);
1074 		break;
1075 	}
1076 }
1077 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1078 
1079 void vb2_discard_done(struct vb2_queue *q)
1080 {
1081 	struct vb2_buffer *vb;
1082 	unsigned long flags;
1083 
1084 	spin_lock_irqsave(&q->done_lock, flags);
1085 	list_for_each_entry(vb, &q->done_list, done_entry)
1086 		vb->state = VB2_BUF_STATE_ERROR;
1087 	spin_unlock_irqrestore(&q->done_lock, flags);
1088 }
1089 EXPORT_SYMBOL_GPL(vb2_discard_done);
1090 
1091 /*
1092  * __prepare_mmap() - prepare an MMAP buffer
1093  */
1094 static int __prepare_mmap(struct vb2_buffer *vb)
1095 {
1096 	int ret = 0;
1097 
1098 	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1099 			 vb, vb->planes);
1100 	return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
1101 }
1102 
1103 /*
1104  * __prepare_userptr() - prepare a USERPTR buffer
1105  */
1106 static int __prepare_userptr(struct vb2_buffer *vb)
1107 {
1108 	struct vb2_plane planes[VB2_MAX_PLANES];
1109 	struct vb2_queue *q = vb->vb2_queue;
1110 	void *mem_priv;
1111 	unsigned int plane;
1112 	int ret = 0;
1113 	bool reacquired = vb->planes[0].mem_priv == NULL;
1114 
1115 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1116 	/* Copy relevant information provided by the userspace */
1117 	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1118 			 vb, planes);
1119 	if (ret)
1120 		return ret;
1121 
1122 	for (plane = 0; plane < vb->num_planes; ++plane) {
1123 		/* Skip the plane if already verified */
1124 		if (vb->planes[plane].m.userptr &&
1125 			vb->planes[plane].m.userptr == planes[plane].m.userptr
1126 			&& vb->planes[plane].length == planes[plane].length)
1127 			continue;
1128 
1129 		dprintk(q, 3, "userspace address for plane %d changed, reacquiring memory\n",
1130 			plane);
1131 
1132 		/* Check if the provided plane buffer is large enough */
1133 		if (planes[plane].length < vb->planes[plane].min_length) {
1134 			dprintk(q, 1, "provided buffer size %u is less than setup size %u for plane %d\n",
1135 						planes[plane].length,
1136 						vb->planes[plane].min_length,
1137 						plane);
1138 			ret = -EINVAL;
1139 			goto err;
1140 		}
1141 
1142 		/* Release previously acquired memory if present */
1143 		if (vb->planes[plane].mem_priv) {
1144 			if (!reacquired) {
1145 				reacquired = true;
1146 				vb->copied_timestamp = 0;
1147 				call_void_vb_qop(vb, buf_cleanup, vb);
1148 			}
1149 			call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1150 		}
1151 
1152 		vb->planes[plane].mem_priv = NULL;
1153 		vb->planes[plane].bytesused = 0;
1154 		vb->planes[plane].length = 0;
1155 		vb->planes[plane].m.userptr = 0;
1156 		vb->planes[plane].data_offset = 0;
1157 
1158 		/* Acquire each plane's memory */
1159 		mem_priv = call_ptr_memop(get_userptr,
1160 					  vb,
1161 					  q->alloc_devs[plane] ? : q->dev,
1162 					  planes[plane].m.userptr,
1163 					  planes[plane].length);
1164 		if (IS_ERR(mem_priv)) {
1165 			dprintk(q, 1, "failed acquiring userspace memory for plane %d\n",
1166 				plane);
1167 			ret = PTR_ERR(mem_priv);
1168 			goto err;
1169 		}
1170 		vb->planes[plane].mem_priv = mem_priv;
1171 	}
1172 
1173 	/*
1174 	 * Now that everything is in order, copy relevant information
1175 	 * provided by userspace.
1176 	 */
1177 	for (plane = 0; plane < vb->num_planes; ++plane) {
1178 		vb->planes[plane].bytesused = planes[plane].bytesused;
1179 		vb->planes[plane].length = planes[plane].length;
1180 		vb->planes[plane].m.userptr = planes[plane].m.userptr;
1181 		vb->planes[plane].data_offset = planes[plane].data_offset;
1182 	}
1183 
1184 	if (reacquired) {
1185 		/*
1186 		 * One or more planes changed, so we must call buf_init to do
1187 		 * the driver-specific initialization on the newly acquired
1188 		 * buffer, if provided.
1189 		 */
1190 		ret = call_vb_qop(vb, buf_init, vb);
1191 		if (ret) {
1192 			dprintk(q, 1, "buffer initialization failed\n");
1193 			goto err;
1194 		}
1195 	}
1196 
1197 	ret = call_vb_qop(vb, buf_prepare, vb);
1198 	if (ret) {
1199 		dprintk(q, 1, "buffer preparation failed\n");
1200 		call_void_vb_qop(vb, buf_cleanup, vb);
1201 		goto err;
1202 	}
1203 
1204 	return 0;
1205 err:
1206 	/* In case of errors, release planes that were already acquired */
1207 	for (plane = 0; plane < vb->num_planes; ++plane) {
1208 		if (vb->planes[plane].mem_priv)
1209 			call_void_memop(vb, put_userptr,
1210 				vb->planes[plane].mem_priv);
1211 		vb->planes[plane].mem_priv = NULL;
1212 		vb->planes[plane].m.userptr = 0;
1213 		vb->planes[plane].length = 0;
1214 	}
1215 
1216 	return ret;
1217 }
1218 
1219 /*
1220  * __prepare_dmabuf() - prepare a DMABUF buffer
1221  */
1222 static int __prepare_dmabuf(struct vb2_buffer *vb)
1223 {
1224 	struct vb2_plane planes[VB2_MAX_PLANES];
1225 	struct vb2_queue *q = vb->vb2_queue;
1226 	void *mem_priv;
1227 	unsigned int plane;
1228 	int ret = 0;
1229 	bool reacquired = vb->planes[0].mem_priv == NULL;
1230 
1231 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1232 	/* Copy relevant information provided by the userspace */
1233 	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1234 			 vb, planes);
1235 	if (ret)
1236 		return ret;
1237 
1238 	for (plane = 0; plane < vb->num_planes; ++plane) {
1239 		struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1240 
1241 		if (IS_ERR_OR_NULL(dbuf)) {
1242 			dprintk(q, 1, "invalid dmabuf fd for plane %d\n",
1243 				plane);
1244 			ret = -EINVAL;
1245 			goto err;
1246 		}
1247 
1248 		/* use DMABUF size if length is not provided */
1249 		if (planes[plane].length == 0)
1250 			planes[plane].length = dbuf->size;
1251 
1252 		if (planes[plane].length < vb->planes[plane].min_length) {
1253 			dprintk(q, 1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1254 				planes[plane].length, plane,
1255 				vb->planes[plane].min_length);
1256 			dma_buf_put(dbuf);
1257 			ret = -EINVAL;
1258 			goto err;
1259 		}
1260 
1261 		/* Skip the plane if already verified */
1262 		if (dbuf == vb->planes[plane].dbuf &&
1263 			vb->planes[plane].length == planes[plane].length) {
1264 			dma_buf_put(dbuf);
1265 			continue;
1266 		}
1267 
1268 		dprintk(q, 3, "buffer for plane %d changed\n", plane);
1269 
1270 		if (!reacquired) {
1271 			reacquired = true;
1272 			vb->copied_timestamp = 0;
1273 			call_void_vb_qop(vb, buf_cleanup, vb);
1274 		}
1275 
1276 		/* Release previously acquired memory if present */
1277 		__vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1278 		vb->planes[plane].bytesused = 0;
1279 		vb->planes[plane].length = 0;
1280 		vb->planes[plane].m.fd = 0;
1281 		vb->planes[plane].data_offset = 0;
1282 
1283 		/* Acquire each plane's memory */
1284 		mem_priv = call_ptr_memop(attach_dmabuf,
1285 					  vb,
1286 					  q->alloc_devs[plane] ? : q->dev,
1287 					  dbuf,
1288 					  planes[plane].length);
1289 		if (IS_ERR(mem_priv)) {
1290 			dprintk(q, 1, "failed to attach dmabuf\n");
1291 			ret = PTR_ERR(mem_priv);
1292 			dma_buf_put(dbuf);
1293 			goto err;
1294 		}
1295 
1296 		vb->planes[plane].dbuf = dbuf;
1297 		vb->planes[plane].mem_priv = mem_priv;
1298 	}
1299 
1300 	/*
1301 	 * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1302 	 * here instead just before the DMA, while queueing the buffer(s) so
1303 	 * userspace knows sooner rather than later if the dma-buf map fails.
1304 	 */
1305 	for (plane = 0; plane < vb->num_planes; ++plane) {
1306 		if (vb->planes[plane].dbuf_mapped)
1307 			continue;
1308 
1309 		ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1310 		if (ret) {
1311 			dprintk(q, 1, "failed to map dmabuf for plane %d\n",
1312 				plane);
1313 			goto err;
1314 		}
1315 		vb->planes[plane].dbuf_mapped = 1;
1316 	}
1317 
1318 	/*
1319 	 * Now that everything is in order, copy relevant information
1320 	 * provided by userspace.
1321 	 */
1322 	for (plane = 0; plane < vb->num_planes; ++plane) {
1323 		vb->planes[plane].bytesused = planes[plane].bytesused;
1324 		vb->planes[plane].length = planes[plane].length;
1325 		vb->planes[plane].m.fd = planes[plane].m.fd;
1326 		vb->planes[plane].data_offset = planes[plane].data_offset;
1327 	}
1328 
1329 	if (reacquired) {
1330 		/*
1331 		 * Call driver-specific initialization on the newly acquired buffer,
1332 		 * if provided.
1333 		 */
1334 		ret = call_vb_qop(vb, buf_init, vb);
1335 		if (ret) {
1336 			dprintk(q, 1, "buffer initialization failed\n");
1337 			goto err;
1338 		}
1339 	}
1340 
1341 	ret = call_vb_qop(vb, buf_prepare, vb);
1342 	if (ret) {
1343 		dprintk(q, 1, "buffer preparation failed\n");
1344 		call_void_vb_qop(vb, buf_cleanup, vb);
1345 		goto err;
1346 	}
1347 
1348 	return 0;
1349 err:
1350 	/* In case of errors, release planes that were already acquired */
1351 	__vb2_buf_dmabuf_put(vb);
1352 
1353 	return ret;
1354 }
1355 
1356 /*
1357  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1358  */
1359 static void __enqueue_in_driver(struct vb2_buffer *vb)
1360 {
1361 	struct vb2_queue *q = vb->vb2_queue;
1362 
1363 	vb->state = VB2_BUF_STATE_ACTIVE;
1364 	atomic_inc(&q->owned_by_drv_count);
1365 
1366 	trace_vb2_buf_queue(q, vb);
1367 
1368 	call_void_vb_qop(vb, buf_queue, vb);
1369 }
1370 
1371 static int __buf_prepare(struct vb2_buffer *vb)
1372 {
1373 	struct vb2_queue *q = vb->vb2_queue;
1374 	enum vb2_buffer_state orig_state = vb->state;
1375 	int ret;
1376 
1377 	if (q->error) {
1378 		dprintk(q, 1, "fatal error occurred on queue\n");
1379 		return -EIO;
1380 	}
1381 
1382 	if (vb->prepared)
1383 		return 0;
1384 	WARN_ON(vb->synced);
1385 
1386 	if (q->is_output) {
1387 		ret = call_vb_qop(vb, buf_out_validate, vb);
1388 		if (ret) {
1389 			dprintk(q, 1, "buffer validation failed\n");
1390 			return ret;
1391 		}
1392 	}
1393 
1394 	vb->state = VB2_BUF_STATE_PREPARING;
1395 
1396 	switch (q->memory) {
1397 	case VB2_MEMORY_MMAP:
1398 		ret = __prepare_mmap(vb);
1399 		break;
1400 	case VB2_MEMORY_USERPTR:
1401 		ret = __prepare_userptr(vb);
1402 		break;
1403 	case VB2_MEMORY_DMABUF:
1404 		ret = __prepare_dmabuf(vb);
1405 		break;
1406 	default:
1407 		WARN(1, "Invalid queue type\n");
1408 		ret = -EINVAL;
1409 		break;
1410 	}
1411 
1412 	if (ret) {
1413 		dprintk(q, 1, "buffer preparation failed: %d\n", ret);
1414 		vb->state = orig_state;
1415 		return ret;
1416 	}
1417 
1418 	__vb2_buf_mem_prepare(vb);
1419 	vb->prepared = 1;
1420 	vb->state = orig_state;
1421 
1422 	return 0;
1423 }
1424 
1425 static int vb2_req_prepare(struct media_request_object *obj)
1426 {
1427 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1428 	int ret;
1429 
1430 	if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
1431 		return -EINVAL;
1432 
1433 	mutex_lock(vb->vb2_queue->lock);
1434 	ret = __buf_prepare(vb);
1435 	mutex_unlock(vb->vb2_queue->lock);
1436 	return ret;
1437 }
1438 
1439 static void __vb2_dqbuf(struct vb2_buffer *vb);
1440 
1441 static void vb2_req_unprepare(struct media_request_object *obj)
1442 {
1443 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1444 
1445 	mutex_lock(vb->vb2_queue->lock);
1446 	__vb2_dqbuf(vb);
1447 	vb->state = VB2_BUF_STATE_IN_REQUEST;
1448 	mutex_unlock(vb->vb2_queue->lock);
1449 	WARN_ON(!vb->req_obj.req);
1450 }
1451 
1452 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1453 		  struct media_request *req);
1454 
1455 static void vb2_req_queue(struct media_request_object *obj)
1456 {
1457 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1458 	int err;
1459 
1460 	mutex_lock(vb->vb2_queue->lock);
1461 	/*
1462 	 * There is no method to propagate an error from vb2_core_qbuf(),
1463 	 * so if this returns a non-0 value, then WARN.
1464 	 *
1465 	 * The only exception is -EIO which is returned if q->error is
1466 	 * set. We just ignore that, and expect this will be caught the
1467 	 * next time vb2_req_prepare() is called.
1468 	 */
1469 	err = vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
1470 	WARN_ON_ONCE(err && err != -EIO);
1471 	mutex_unlock(vb->vb2_queue->lock);
1472 }
1473 
1474 static void vb2_req_unbind(struct media_request_object *obj)
1475 {
1476 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1477 
1478 	if (vb->state == VB2_BUF_STATE_IN_REQUEST)
1479 		call_void_bufop(vb->vb2_queue, init_buffer, vb);
1480 }
1481 
1482 static void vb2_req_release(struct media_request_object *obj)
1483 {
1484 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1485 
1486 	if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
1487 		vb->state = VB2_BUF_STATE_DEQUEUED;
1488 		if (vb->request)
1489 			media_request_put(vb->request);
1490 		vb->request = NULL;
1491 	}
1492 }
1493 
1494 static const struct media_request_object_ops vb2_core_req_ops = {
1495 	.prepare = vb2_req_prepare,
1496 	.unprepare = vb2_req_unprepare,
1497 	.queue = vb2_req_queue,
1498 	.unbind = vb2_req_unbind,
1499 	.release = vb2_req_release,
1500 };
1501 
1502 bool vb2_request_object_is_buffer(struct media_request_object *obj)
1503 {
1504 	return obj->ops == &vb2_core_req_ops;
1505 }
1506 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
1507 
1508 unsigned int vb2_request_buffer_cnt(struct media_request *req)
1509 {
1510 	struct media_request_object *obj;
1511 	unsigned long flags;
1512 	unsigned int buffer_cnt = 0;
1513 
1514 	spin_lock_irqsave(&req->lock, flags);
1515 	list_for_each_entry(obj, &req->objects, list)
1516 		if (vb2_request_object_is_buffer(obj))
1517 			buffer_cnt++;
1518 	spin_unlock_irqrestore(&req->lock, flags);
1519 
1520 	return buffer_cnt;
1521 }
1522 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
1523 
1524 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1525 {
1526 	struct vb2_buffer *vb;
1527 	int ret;
1528 
1529 	vb = q->bufs[index];
1530 	if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1531 		dprintk(q, 1, "invalid buffer state %s\n",
1532 			vb2_state_name(vb->state));
1533 		return -EINVAL;
1534 	}
1535 	if (vb->prepared) {
1536 		dprintk(q, 1, "buffer already prepared\n");
1537 		return -EINVAL;
1538 	}
1539 
1540 	ret = __buf_prepare(vb);
1541 	if (ret)
1542 		return ret;
1543 
1544 	/* Fill buffer information for the userspace */
1545 	call_void_bufop(q, fill_user_buffer, vb, pb);
1546 
1547 	dprintk(q, 2, "prepare of buffer %d succeeded\n", vb->index);
1548 
1549 	return 0;
1550 }
1551 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1552 
1553 /*
1554  * vb2_start_streaming() - Attempt to start streaming.
1555  * @q:		videobuf2 queue
1556  *
1557  * Attempt to start streaming. When this function is called there must be
1558  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1559  * number of buffers required for the DMA engine to function). If the
1560  * @start_streaming op fails it is supposed to return all the driver-owned
1561  * buffers back to vb2 in state QUEUED. Check if that happened and if
1562  * not warn and reclaim them forcefully.
1563  */
1564 static int vb2_start_streaming(struct vb2_queue *q)
1565 {
1566 	struct vb2_buffer *vb;
1567 	int ret;
1568 
1569 	/*
1570 	 * If any buffers were queued before streamon,
1571 	 * we can now pass them to driver for processing.
1572 	 */
1573 	list_for_each_entry(vb, &q->queued_list, queued_entry)
1574 		__enqueue_in_driver(vb);
1575 
1576 	/* Tell the driver to start streaming */
1577 	q->start_streaming_called = 1;
1578 	ret = call_qop(q, start_streaming, q,
1579 		       atomic_read(&q->owned_by_drv_count));
1580 	if (!ret)
1581 		return 0;
1582 
1583 	q->start_streaming_called = 0;
1584 
1585 	dprintk(q, 1, "driver refused to start streaming\n");
1586 	/*
1587 	 * If you see this warning, then the driver isn't cleaning up properly
1588 	 * after a failed start_streaming(). See the start_streaming()
1589 	 * documentation in videobuf2-core.h for more information how buffers
1590 	 * should be returned to vb2 in start_streaming().
1591 	 */
1592 	if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1593 		unsigned i;
1594 
1595 		/*
1596 		 * Forcefully reclaim buffers if the driver did not
1597 		 * correctly return them to vb2.
1598 		 */
1599 		for (i = 0; i < q->num_buffers; ++i) {
1600 			vb = q->bufs[i];
1601 			if (vb->state == VB2_BUF_STATE_ACTIVE)
1602 				vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1603 		}
1604 		/* Must be zero now */
1605 		WARN_ON(atomic_read(&q->owned_by_drv_count));
1606 	}
1607 	/*
1608 	 * If done_list is not empty, then start_streaming() didn't call
1609 	 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1610 	 * STATE_DONE.
1611 	 */
1612 	WARN_ON(!list_empty(&q->done_list));
1613 	return ret;
1614 }
1615 
1616 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1617 		  struct media_request *req)
1618 {
1619 	struct vb2_buffer *vb;
1620 	enum vb2_buffer_state orig_state;
1621 	int ret;
1622 
1623 	if (q->error) {
1624 		dprintk(q, 1, "fatal error occurred on queue\n");
1625 		return -EIO;
1626 	}
1627 
1628 	vb = q->bufs[index];
1629 
1630 	if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1631 	    q->requires_requests) {
1632 		dprintk(q, 1, "qbuf requires a request\n");
1633 		return -EBADR;
1634 	}
1635 
1636 	if ((req && q->uses_qbuf) ||
1637 	    (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1638 	     q->uses_requests)) {
1639 		dprintk(q, 1, "queue in wrong mode (qbuf vs requests)\n");
1640 		return -EBUSY;
1641 	}
1642 
1643 	if (req) {
1644 		int ret;
1645 
1646 		q->uses_requests = 1;
1647 		if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1648 			dprintk(q, 1, "buffer %d not in dequeued state\n",
1649 				vb->index);
1650 			return -EINVAL;
1651 		}
1652 
1653 		if (q->is_output && !vb->prepared) {
1654 			ret = call_vb_qop(vb, buf_out_validate, vb);
1655 			if (ret) {
1656 				dprintk(q, 1, "buffer validation failed\n");
1657 				return ret;
1658 			}
1659 		}
1660 
1661 		media_request_object_init(&vb->req_obj);
1662 
1663 		/* Make sure the request is in a safe state for updating. */
1664 		ret = media_request_lock_for_update(req);
1665 		if (ret)
1666 			return ret;
1667 		ret = media_request_object_bind(req, &vb2_core_req_ops,
1668 						q, true, &vb->req_obj);
1669 		media_request_unlock_for_update(req);
1670 		if (ret)
1671 			return ret;
1672 
1673 		vb->state = VB2_BUF_STATE_IN_REQUEST;
1674 
1675 		/*
1676 		 * Increment the refcount and store the request.
1677 		 * The request refcount is decremented again when the
1678 		 * buffer is dequeued. This is to prevent vb2_buffer_done()
1679 		 * from freeing the request from interrupt context, which can
1680 		 * happen if the application closed the request fd after
1681 		 * queueing the request.
1682 		 */
1683 		media_request_get(req);
1684 		vb->request = req;
1685 
1686 		/* Fill buffer information for the userspace */
1687 		if (pb) {
1688 			call_void_bufop(q, copy_timestamp, vb, pb);
1689 			call_void_bufop(q, fill_user_buffer, vb, pb);
1690 		}
1691 
1692 		dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1693 		return 0;
1694 	}
1695 
1696 	if (vb->state != VB2_BUF_STATE_IN_REQUEST)
1697 		q->uses_qbuf = 1;
1698 
1699 	switch (vb->state) {
1700 	case VB2_BUF_STATE_DEQUEUED:
1701 	case VB2_BUF_STATE_IN_REQUEST:
1702 		if (!vb->prepared) {
1703 			ret = __buf_prepare(vb);
1704 			if (ret)
1705 				return ret;
1706 		}
1707 		break;
1708 	case VB2_BUF_STATE_PREPARING:
1709 		dprintk(q, 1, "buffer still being prepared\n");
1710 		return -EINVAL;
1711 	default:
1712 		dprintk(q, 1, "invalid buffer state %s\n",
1713 			vb2_state_name(vb->state));
1714 		return -EINVAL;
1715 	}
1716 
1717 	/*
1718 	 * Add to the queued buffers list, a buffer will stay on it until
1719 	 * dequeued in dqbuf.
1720 	 */
1721 	orig_state = vb->state;
1722 	list_add_tail(&vb->queued_entry, &q->queued_list);
1723 	q->queued_count++;
1724 	q->waiting_for_buffers = false;
1725 	vb->state = VB2_BUF_STATE_QUEUED;
1726 
1727 	if (pb)
1728 		call_void_bufop(q, copy_timestamp, vb, pb);
1729 
1730 	trace_vb2_qbuf(q, vb);
1731 
1732 	/*
1733 	 * If already streaming, give the buffer to driver for processing.
1734 	 * If not, the buffer will be given to driver on next streamon.
1735 	 */
1736 	if (q->start_streaming_called)
1737 		__enqueue_in_driver(vb);
1738 
1739 	/* Fill buffer information for the userspace */
1740 	if (pb)
1741 		call_void_bufop(q, fill_user_buffer, vb, pb);
1742 
1743 	/*
1744 	 * If streamon has been called, and we haven't yet called
1745 	 * start_streaming() since not enough buffers were queued, and
1746 	 * we now have reached the minimum number of queued buffers,
1747 	 * then we can finally call start_streaming().
1748 	 */
1749 	if (q->streaming && !q->start_streaming_called &&
1750 	    q->queued_count >= q->min_buffers_needed) {
1751 		ret = vb2_start_streaming(q);
1752 		if (ret) {
1753 			/*
1754 			 * Since vb2_core_qbuf will return with an error,
1755 			 * we should return it to state DEQUEUED since
1756 			 * the error indicates that the buffer wasn't queued.
1757 			 */
1758 			list_del(&vb->queued_entry);
1759 			q->queued_count--;
1760 			vb->state = orig_state;
1761 			return ret;
1762 		}
1763 	}
1764 
1765 	dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1766 	return 0;
1767 }
1768 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1769 
1770 /*
1771  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1772  * for dequeuing
1773  *
1774  * Will sleep if required for nonblocking == false.
1775  */
1776 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1777 {
1778 	/*
1779 	 * All operations on vb_done_list are performed under done_lock
1780 	 * spinlock protection. However, buffers may be removed from
1781 	 * it and returned to userspace only while holding both driver's
1782 	 * lock and the done_lock spinlock. Thus we can be sure that as
1783 	 * long as we hold the driver's lock, the list will remain not
1784 	 * empty if list_empty() check succeeds.
1785 	 */
1786 
1787 	for (;;) {
1788 		int ret;
1789 
1790 		if (q->waiting_in_dqbuf) {
1791 			dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
1792 			return -EBUSY;
1793 		}
1794 
1795 		if (!q->streaming) {
1796 			dprintk(q, 1, "streaming off, will not wait for buffers\n");
1797 			return -EINVAL;
1798 		}
1799 
1800 		if (q->error) {
1801 			dprintk(q, 1, "Queue in error state, will not wait for buffers\n");
1802 			return -EIO;
1803 		}
1804 
1805 		if (q->last_buffer_dequeued) {
1806 			dprintk(q, 3, "last buffer dequeued already, will not wait for buffers\n");
1807 			return -EPIPE;
1808 		}
1809 
1810 		if (!list_empty(&q->done_list)) {
1811 			/*
1812 			 * Found a buffer that we were waiting for.
1813 			 */
1814 			break;
1815 		}
1816 
1817 		if (nonblocking) {
1818 			dprintk(q, 3, "nonblocking and no buffers to dequeue, will not wait\n");
1819 			return -EAGAIN;
1820 		}
1821 
1822 		q->waiting_in_dqbuf = 1;
1823 		/*
1824 		 * We are streaming and blocking, wait for another buffer to
1825 		 * become ready or for streamoff. Driver's lock is released to
1826 		 * allow streamoff or qbuf to be called while waiting.
1827 		 */
1828 		call_void_qop(q, wait_prepare, q);
1829 
1830 		/*
1831 		 * All locks have been released, it is safe to sleep now.
1832 		 */
1833 		dprintk(q, 3, "will sleep waiting for buffers\n");
1834 		ret = wait_event_interruptible(q->done_wq,
1835 				!list_empty(&q->done_list) || !q->streaming ||
1836 				q->error);
1837 
1838 		/*
1839 		 * We need to reevaluate both conditions again after reacquiring
1840 		 * the locks or return an error if one occurred.
1841 		 */
1842 		call_void_qop(q, wait_finish, q);
1843 		q->waiting_in_dqbuf = 0;
1844 		if (ret) {
1845 			dprintk(q, 1, "sleep was interrupted\n");
1846 			return ret;
1847 		}
1848 	}
1849 	return 0;
1850 }
1851 
1852 /*
1853  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1854  *
1855  * Will sleep if required for nonblocking == false.
1856  */
1857 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1858 			     void *pb, int nonblocking)
1859 {
1860 	unsigned long flags;
1861 	int ret = 0;
1862 
1863 	/*
1864 	 * Wait for at least one buffer to become available on the done_list.
1865 	 */
1866 	ret = __vb2_wait_for_done_vb(q, nonblocking);
1867 	if (ret)
1868 		return ret;
1869 
1870 	/*
1871 	 * Driver's lock has been held since we last verified that done_list
1872 	 * is not empty, so no need for another list_empty(done_list) check.
1873 	 */
1874 	spin_lock_irqsave(&q->done_lock, flags);
1875 	*vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1876 	/*
1877 	 * Only remove the buffer from done_list if all planes can be
1878 	 * handled. Some cases such as V4L2 file I/O and DVB have pb
1879 	 * == NULL; skip the check then as there's nothing to verify.
1880 	 */
1881 	if (pb)
1882 		ret = call_bufop(q, verify_planes_array, *vb, pb);
1883 	if (!ret)
1884 		list_del(&(*vb)->done_entry);
1885 	spin_unlock_irqrestore(&q->done_lock, flags);
1886 
1887 	return ret;
1888 }
1889 
1890 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1891 {
1892 	if (!q->streaming) {
1893 		dprintk(q, 1, "streaming off, will not wait for buffers\n");
1894 		return -EINVAL;
1895 	}
1896 
1897 	if (q->start_streaming_called)
1898 		wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1899 	return 0;
1900 }
1901 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1902 
1903 /*
1904  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1905  */
1906 static void __vb2_dqbuf(struct vb2_buffer *vb)
1907 {
1908 	struct vb2_queue *q = vb->vb2_queue;
1909 
1910 	/* nothing to do if the buffer is already dequeued */
1911 	if (vb->state == VB2_BUF_STATE_DEQUEUED)
1912 		return;
1913 
1914 	vb->state = VB2_BUF_STATE_DEQUEUED;
1915 
1916 	call_void_bufop(q, init_buffer, vb);
1917 }
1918 
1919 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1920 		   bool nonblocking)
1921 {
1922 	struct vb2_buffer *vb = NULL;
1923 	int ret;
1924 
1925 	ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1926 	if (ret < 0)
1927 		return ret;
1928 
1929 	switch (vb->state) {
1930 	case VB2_BUF_STATE_DONE:
1931 		dprintk(q, 3, "returning done buffer\n");
1932 		break;
1933 	case VB2_BUF_STATE_ERROR:
1934 		dprintk(q, 3, "returning done buffer with errors\n");
1935 		break;
1936 	default:
1937 		dprintk(q, 1, "invalid buffer state %s\n",
1938 			vb2_state_name(vb->state));
1939 		return -EINVAL;
1940 	}
1941 
1942 	call_void_vb_qop(vb, buf_finish, vb);
1943 	vb->prepared = 0;
1944 
1945 	if (pindex)
1946 		*pindex = vb->index;
1947 
1948 	/* Fill buffer information for the userspace */
1949 	if (pb)
1950 		call_void_bufop(q, fill_user_buffer, vb, pb);
1951 
1952 	/* Remove from videobuf queue */
1953 	list_del(&vb->queued_entry);
1954 	q->queued_count--;
1955 
1956 	trace_vb2_dqbuf(q, vb);
1957 
1958 	/* go back to dequeued state */
1959 	__vb2_dqbuf(vb);
1960 
1961 	if (WARN_ON(vb->req_obj.req)) {
1962 		media_request_object_unbind(&vb->req_obj);
1963 		media_request_object_put(&vb->req_obj);
1964 	}
1965 	if (vb->request)
1966 		media_request_put(vb->request);
1967 	vb->request = NULL;
1968 
1969 	dprintk(q, 2, "dqbuf of buffer %d, state: %s\n",
1970 		vb->index, vb2_state_name(vb->state));
1971 
1972 	return 0;
1973 
1974 }
1975 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1976 
1977 /*
1978  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1979  *
1980  * Removes all queued buffers from driver's queue and all buffers queued by
1981  * userspace from videobuf's queue. Returns to state after reqbufs.
1982  */
1983 static void __vb2_queue_cancel(struct vb2_queue *q)
1984 {
1985 	unsigned int i;
1986 
1987 	/*
1988 	 * Tell driver to stop all transactions and release all queued
1989 	 * buffers.
1990 	 */
1991 	if (q->start_streaming_called)
1992 		call_void_qop(q, stop_streaming, q);
1993 
1994 	/*
1995 	 * If you see this warning, then the driver isn't cleaning up properly
1996 	 * in stop_streaming(). See the stop_streaming() documentation in
1997 	 * videobuf2-core.h for more information how buffers should be returned
1998 	 * to vb2 in stop_streaming().
1999 	 */
2000 	if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
2001 		for (i = 0; i < q->num_buffers; ++i)
2002 			if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
2003 				pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
2004 					q->bufs[i]);
2005 				vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
2006 			}
2007 		/* Must be zero now */
2008 		WARN_ON(atomic_read(&q->owned_by_drv_count));
2009 	}
2010 
2011 	q->streaming = 0;
2012 	q->start_streaming_called = 0;
2013 	q->queued_count = 0;
2014 	q->error = 0;
2015 	q->uses_requests = 0;
2016 	q->uses_qbuf = 0;
2017 
2018 	/*
2019 	 * Remove all buffers from videobuf's list...
2020 	 */
2021 	INIT_LIST_HEAD(&q->queued_list);
2022 	/*
2023 	 * ...and done list; userspace will not receive any buffers it
2024 	 * has not already dequeued before initiating cancel.
2025 	 */
2026 	INIT_LIST_HEAD(&q->done_list);
2027 	atomic_set(&q->owned_by_drv_count, 0);
2028 	wake_up_all(&q->done_wq);
2029 
2030 	/*
2031 	 * Reinitialize all buffers for next use.
2032 	 * Make sure to call buf_finish for any queued buffers. Normally
2033 	 * that's done in dqbuf, but that's not going to happen when we
2034 	 * cancel the whole queue. Note: this code belongs here, not in
2035 	 * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
2036 	 * call to __fill_user_buffer() after buf_finish(). That order can't
2037 	 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2038 	 */
2039 	for (i = 0; i < q->num_buffers; ++i) {
2040 		struct vb2_buffer *vb = q->bufs[i];
2041 		struct media_request *req = vb->req_obj.req;
2042 
2043 		/*
2044 		 * If a request is associated with this buffer, then
2045 		 * call buf_request_cancel() to give the driver to complete()
2046 		 * related request objects. Otherwise those objects would
2047 		 * never complete.
2048 		 */
2049 		if (req) {
2050 			enum media_request_state state;
2051 			unsigned long flags;
2052 
2053 			spin_lock_irqsave(&req->lock, flags);
2054 			state = req->state;
2055 			spin_unlock_irqrestore(&req->lock, flags);
2056 
2057 			if (state == MEDIA_REQUEST_STATE_QUEUED)
2058 				call_void_vb_qop(vb, buf_request_complete, vb);
2059 		}
2060 
2061 		__vb2_buf_mem_finish(vb);
2062 
2063 		if (vb->prepared) {
2064 			call_void_vb_qop(vb, buf_finish, vb);
2065 			vb->prepared = 0;
2066 		}
2067 		__vb2_dqbuf(vb);
2068 
2069 		if (vb->req_obj.req) {
2070 			media_request_object_unbind(&vb->req_obj);
2071 			media_request_object_put(&vb->req_obj);
2072 		}
2073 		if (vb->request)
2074 			media_request_put(vb->request);
2075 		vb->request = NULL;
2076 		vb->copied_timestamp = 0;
2077 	}
2078 }
2079 
2080 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
2081 {
2082 	int ret;
2083 
2084 	if (type != q->type) {
2085 		dprintk(q, 1, "invalid stream type\n");
2086 		return -EINVAL;
2087 	}
2088 
2089 	if (q->streaming) {
2090 		dprintk(q, 3, "already streaming\n");
2091 		return 0;
2092 	}
2093 
2094 	if (!q->num_buffers) {
2095 		dprintk(q, 1, "no buffers have been allocated\n");
2096 		return -EINVAL;
2097 	}
2098 
2099 	if (q->num_buffers < q->min_buffers_needed) {
2100 		dprintk(q, 1, "need at least %u allocated buffers\n",
2101 				q->min_buffers_needed);
2102 		return -EINVAL;
2103 	}
2104 
2105 	/*
2106 	 * Tell driver to start streaming provided sufficient buffers
2107 	 * are available.
2108 	 */
2109 	if (q->queued_count >= q->min_buffers_needed) {
2110 		ret = v4l_vb2q_enable_media_source(q);
2111 		if (ret)
2112 			return ret;
2113 		ret = vb2_start_streaming(q);
2114 		if (ret)
2115 			return ret;
2116 	}
2117 
2118 	q->streaming = 1;
2119 
2120 	dprintk(q, 3, "successful\n");
2121 	return 0;
2122 }
2123 EXPORT_SYMBOL_GPL(vb2_core_streamon);
2124 
2125 void vb2_queue_error(struct vb2_queue *q)
2126 {
2127 	q->error = 1;
2128 
2129 	wake_up_all(&q->done_wq);
2130 }
2131 EXPORT_SYMBOL_GPL(vb2_queue_error);
2132 
2133 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
2134 {
2135 	if (type != q->type) {
2136 		dprintk(q, 1, "invalid stream type\n");
2137 		return -EINVAL;
2138 	}
2139 
2140 	/*
2141 	 * Cancel will pause streaming and remove all buffers from the driver
2142 	 * and videobuf, effectively returning control over them to userspace.
2143 	 *
2144 	 * Note that we do this even if q->streaming == 0: if you prepare or
2145 	 * queue buffers, and then call streamoff without ever having called
2146 	 * streamon, you would still expect those buffers to be returned to
2147 	 * their normal dequeued state.
2148 	 */
2149 	__vb2_queue_cancel(q);
2150 	q->waiting_for_buffers = !q->is_output;
2151 	q->last_buffer_dequeued = false;
2152 
2153 	dprintk(q, 3, "successful\n");
2154 	return 0;
2155 }
2156 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
2157 
2158 /*
2159  * __find_plane_by_offset() - find plane associated with the given offset off
2160  */
2161 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2162 			unsigned int *_buffer, unsigned int *_plane)
2163 {
2164 	struct vb2_buffer *vb;
2165 	unsigned int buffer, plane;
2166 
2167 	/*
2168 	 * Go over all buffers and their planes, comparing the given offset
2169 	 * with an offset assigned to each plane. If a match is found,
2170 	 * return its buffer and plane numbers.
2171 	 */
2172 	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2173 		vb = q->bufs[buffer];
2174 
2175 		for (plane = 0; plane < vb->num_planes; ++plane) {
2176 			if (vb->planes[plane].m.offset == off) {
2177 				*_buffer = buffer;
2178 				*_plane = plane;
2179 				return 0;
2180 			}
2181 		}
2182 	}
2183 
2184 	return -EINVAL;
2185 }
2186 
2187 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
2188 		unsigned int index, unsigned int plane, unsigned int flags)
2189 {
2190 	struct vb2_buffer *vb = NULL;
2191 	struct vb2_plane *vb_plane;
2192 	int ret;
2193 	struct dma_buf *dbuf;
2194 
2195 	if (q->memory != VB2_MEMORY_MMAP) {
2196 		dprintk(q, 1, "queue is not currently set up for mmap\n");
2197 		return -EINVAL;
2198 	}
2199 
2200 	if (!q->mem_ops->get_dmabuf) {
2201 		dprintk(q, 1, "queue does not support DMA buffer exporting\n");
2202 		return -EINVAL;
2203 	}
2204 
2205 	if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2206 		dprintk(q, 1, "queue does support only O_CLOEXEC and access mode flags\n");
2207 		return -EINVAL;
2208 	}
2209 
2210 	if (type != q->type) {
2211 		dprintk(q, 1, "invalid buffer type\n");
2212 		return -EINVAL;
2213 	}
2214 
2215 	if (index >= q->num_buffers) {
2216 		dprintk(q, 1, "buffer index out of range\n");
2217 		return -EINVAL;
2218 	}
2219 
2220 	vb = q->bufs[index];
2221 
2222 	if (plane >= vb->num_planes) {
2223 		dprintk(q, 1, "buffer plane out of range\n");
2224 		return -EINVAL;
2225 	}
2226 
2227 	if (vb2_fileio_is_active(q)) {
2228 		dprintk(q, 1, "expbuf: file io in progress\n");
2229 		return -EBUSY;
2230 	}
2231 
2232 	vb_plane = &vb->planes[plane];
2233 
2234 	dbuf = call_ptr_memop(get_dmabuf,
2235 			      vb,
2236 			      vb_plane->mem_priv,
2237 			      flags & O_ACCMODE);
2238 	if (IS_ERR_OR_NULL(dbuf)) {
2239 		dprintk(q, 1, "failed to export buffer %d, plane %d\n",
2240 			index, plane);
2241 		return -EINVAL;
2242 	}
2243 
2244 	ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2245 	if (ret < 0) {
2246 		dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",
2247 			index, plane, ret);
2248 		dma_buf_put(dbuf);
2249 		return ret;
2250 	}
2251 
2252 	dprintk(q, 3, "buffer %d, plane %d exported as %d descriptor\n",
2253 		index, plane, ret);
2254 	*fd = ret;
2255 
2256 	return 0;
2257 }
2258 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2259 
2260 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2261 {
2262 	unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2263 	struct vb2_buffer *vb;
2264 	unsigned int buffer = 0, plane = 0;
2265 	int ret;
2266 	unsigned long length;
2267 
2268 	if (q->memory != VB2_MEMORY_MMAP) {
2269 		dprintk(q, 1, "queue is not currently set up for mmap\n");
2270 		return -EINVAL;
2271 	}
2272 
2273 	/*
2274 	 * Check memory area access mode.
2275 	 */
2276 	if (!(vma->vm_flags & VM_SHARED)) {
2277 		dprintk(q, 1, "invalid vma flags, VM_SHARED needed\n");
2278 		return -EINVAL;
2279 	}
2280 	if (q->is_output) {
2281 		if (!(vma->vm_flags & VM_WRITE)) {
2282 			dprintk(q, 1, "invalid vma flags, VM_WRITE needed\n");
2283 			return -EINVAL;
2284 		}
2285 	} else {
2286 		if (!(vma->vm_flags & VM_READ)) {
2287 			dprintk(q, 1, "invalid vma flags, VM_READ needed\n");
2288 			return -EINVAL;
2289 		}
2290 	}
2291 
2292 	mutex_lock(&q->mmap_lock);
2293 
2294 	if (vb2_fileio_is_active(q)) {
2295 		dprintk(q, 1, "mmap: file io in progress\n");
2296 		ret = -EBUSY;
2297 		goto unlock;
2298 	}
2299 
2300 	/*
2301 	 * Find the plane corresponding to the offset passed by userspace.
2302 	 */
2303 	ret = __find_plane_by_offset(q, off, &buffer, &plane);
2304 	if (ret)
2305 		goto unlock;
2306 
2307 	vb = q->bufs[buffer];
2308 
2309 	/*
2310 	 * MMAP requires page_aligned buffers.
2311 	 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2312 	 * so, we need to do the same here.
2313 	 */
2314 	length = PAGE_ALIGN(vb->planes[plane].length);
2315 	if (length < (vma->vm_end - vma->vm_start)) {
2316 		dprintk(q, 1,
2317 			"MMAP invalid, as it would overflow buffer length\n");
2318 		ret = -EINVAL;
2319 		goto unlock;
2320 	}
2321 
2322 	/*
2323 	 * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
2324 	 * not as a in-buffer offset. We always want to mmap a whole buffer
2325 	 * from its beginning.
2326 	 */
2327 	vma->vm_pgoff = 0;
2328 
2329 	ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2330 
2331 unlock:
2332 	mutex_unlock(&q->mmap_lock);
2333 	if (ret)
2334 		return ret;
2335 
2336 	dprintk(q, 3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2337 	return 0;
2338 }
2339 EXPORT_SYMBOL_GPL(vb2_mmap);
2340 
2341 #ifndef CONFIG_MMU
2342 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2343 				    unsigned long addr,
2344 				    unsigned long len,
2345 				    unsigned long pgoff,
2346 				    unsigned long flags)
2347 {
2348 	unsigned long off = pgoff << PAGE_SHIFT;
2349 	struct vb2_buffer *vb;
2350 	unsigned int buffer, plane;
2351 	void *vaddr;
2352 	int ret;
2353 
2354 	if (q->memory != VB2_MEMORY_MMAP) {
2355 		dprintk(q, 1, "queue is not currently set up for mmap\n");
2356 		return -EINVAL;
2357 	}
2358 
2359 	/*
2360 	 * Find the plane corresponding to the offset passed by userspace.
2361 	 */
2362 	ret = __find_plane_by_offset(q, off, &buffer, &plane);
2363 	if (ret)
2364 		return ret;
2365 
2366 	vb = q->bufs[buffer];
2367 
2368 	vaddr = vb2_plane_vaddr(vb, plane);
2369 	return vaddr ? (unsigned long)vaddr : -EINVAL;
2370 }
2371 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2372 #endif
2373 
2374 int vb2_core_queue_init(struct vb2_queue *q)
2375 {
2376 	/*
2377 	 * Sanity check
2378 	 */
2379 	if (WARN_ON(!q)			  ||
2380 	    WARN_ON(!q->ops)		  ||
2381 	    WARN_ON(!q->mem_ops)	  ||
2382 	    WARN_ON(!q->type)		  ||
2383 	    WARN_ON(!q->io_modes)	  ||
2384 	    WARN_ON(!q->ops->queue_setup) ||
2385 	    WARN_ON(!q->ops->buf_queue))
2386 		return -EINVAL;
2387 
2388 	if (WARN_ON(q->requires_requests && !q->supports_requests))
2389 		return -EINVAL;
2390 
2391 	/*
2392 	 * This combination is not allowed since a non-zero value of
2393 	 * q->min_buffers_needed can cause vb2_core_qbuf() to fail if
2394 	 * it has to call start_streaming(), and the Request API expects
2395 	 * that queueing a request (and thus queueing a buffer contained
2396 	 * in that request) will always succeed. There is no method of
2397 	 * propagating an error back to userspace.
2398 	 */
2399 	if (WARN_ON(q->supports_requests && q->min_buffers_needed))
2400 		return -EINVAL;
2401 
2402 	INIT_LIST_HEAD(&q->queued_list);
2403 	INIT_LIST_HEAD(&q->done_list);
2404 	spin_lock_init(&q->done_lock);
2405 	mutex_init(&q->mmap_lock);
2406 	init_waitqueue_head(&q->done_wq);
2407 
2408 	q->memory = VB2_MEMORY_UNKNOWN;
2409 
2410 	if (q->buf_struct_size == 0)
2411 		q->buf_struct_size = sizeof(struct vb2_buffer);
2412 
2413 	if (q->bidirectional)
2414 		q->dma_dir = DMA_BIDIRECTIONAL;
2415 	else
2416 		q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2417 
2418 	if (q->name[0] == '\0')
2419 		snprintf(q->name, sizeof(q->name), "%s-%p",
2420 			 q->is_output ? "out" : "cap", q);
2421 
2422 	return 0;
2423 }
2424 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2425 
2426 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2427 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2428 void vb2_core_queue_release(struct vb2_queue *q)
2429 {
2430 	__vb2_cleanup_fileio(q);
2431 	__vb2_queue_cancel(q);
2432 	mutex_lock(&q->mmap_lock);
2433 	__vb2_queue_free(q, q->num_buffers);
2434 	mutex_unlock(&q->mmap_lock);
2435 }
2436 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2437 
2438 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2439 		poll_table *wait)
2440 {
2441 	__poll_t req_events = poll_requested_events(wait);
2442 	struct vb2_buffer *vb = NULL;
2443 	unsigned long flags;
2444 
2445 	/*
2446 	 * poll_wait() MUST be called on the first invocation on all the
2447 	 * potential queues of interest, even if we are not interested in their
2448 	 * events during this first call. Failure to do so will result in
2449 	 * queue's events to be ignored because the poll_table won't be capable
2450 	 * of adding new wait queues thereafter.
2451 	 */
2452 	poll_wait(file, &q->done_wq, wait);
2453 
2454 	if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
2455 		return 0;
2456 	if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
2457 		return 0;
2458 
2459 	/*
2460 	 * Start file I/O emulator only if streaming API has not been used yet.
2461 	 */
2462 	if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2463 		if (!q->is_output && (q->io_modes & VB2_READ) &&
2464 				(req_events & (EPOLLIN | EPOLLRDNORM))) {
2465 			if (__vb2_init_fileio(q, 1))
2466 				return EPOLLERR;
2467 		}
2468 		if (q->is_output && (q->io_modes & VB2_WRITE) &&
2469 				(req_events & (EPOLLOUT | EPOLLWRNORM))) {
2470 			if (__vb2_init_fileio(q, 0))
2471 				return EPOLLERR;
2472 			/*
2473 			 * Write to OUTPUT queue can be done immediately.
2474 			 */
2475 			return EPOLLOUT | EPOLLWRNORM;
2476 		}
2477 	}
2478 
2479 	/*
2480 	 * There is nothing to wait for if the queue isn't streaming, or if the
2481 	 * error flag is set.
2482 	 */
2483 	if (!vb2_is_streaming(q) || q->error)
2484 		return EPOLLERR;
2485 
2486 	/*
2487 	 * If this quirk is set and QBUF hasn't been called yet then
2488 	 * return EPOLLERR as well. This only affects capture queues, output
2489 	 * queues will always initialize waiting_for_buffers to false.
2490 	 * This quirk is set by V4L2 for backwards compatibility reasons.
2491 	 */
2492 	if (q->quirk_poll_must_check_waiting_for_buffers &&
2493 	    q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
2494 		return EPOLLERR;
2495 
2496 	/*
2497 	 * For output streams you can call write() as long as there are fewer
2498 	 * buffers queued than there are buffers available.
2499 	 */
2500 	if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2501 		return EPOLLOUT | EPOLLWRNORM;
2502 
2503 	if (list_empty(&q->done_list)) {
2504 		/*
2505 		 * If the last buffer was dequeued from a capture queue,
2506 		 * return immediately. DQBUF will return -EPIPE.
2507 		 */
2508 		if (q->last_buffer_dequeued)
2509 			return EPOLLIN | EPOLLRDNORM;
2510 	}
2511 
2512 	/*
2513 	 * Take first buffer available for dequeuing.
2514 	 */
2515 	spin_lock_irqsave(&q->done_lock, flags);
2516 	if (!list_empty(&q->done_list))
2517 		vb = list_first_entry(&q->done_list, struct vb2_buffer,
2518 					done_entry);
2519 	spin_unlock_irqrestore(&q->done_lock, flags);
2520 
2521 	if (vb && (vb->state == VB2_BUF_STATE_DONE
2522 			|| vb->state == VB2_BUF_STATE_ERROR)) {
2523 		return (q->is_output) ?
2524 				EPOLLOUT | EPOLLWRNORM :
2525 				EPOLLIN | EPOLLRDNORM;
2526 	}
2527 	return 0;
2528 }
2529 EXPORT_SYMBOL_GPL(vb2_core_poll);
2530 
2531 /*
2532  * struct vb2_fileio_buf - buffer context used by file io emulator
2533  *
2534  * vb2 provides a compatibility layer and emulator of file io (read and
2535  * write) calls on top of streaming API. This structure is used for
2536  * tracking context related to the buffers.
2537  */
2538 struct vb2_fileio_buf {
2539 	void *vaddr;
2540 	unsigned int size;
2541 	unsigned int pos;
2542 	unsigned int queued:1;
2543 };
2544 
2545 /*
2546  * struct vb2_fileio_data - queue context used by file io emulator
2547  *
2548  * @cur_index:	the index of the buffer currently being read from or
2549  *		written to. If equal to q->num_buffers then a new buffer
2550  *		must be dequeued.
2551  * @initial_index: in the read() case all buffers are queued up immediately
2552  *		in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2553  *		buffers. However, in the write() case no buffers are initially
2554  *		queued, instead whenever a buffer is full it is queued up by
2555  *		__vb2_perform_fileio(). Only once all available buffers have
2556  *		been queued up will __vb2_perform_fileio() start to dequeue
2557  *		buffers. This means that initially __vb2_perform_fileio()
2558  *		needs to know what buffer index to use when it is queuing up
2559  *		the buffers for the first time. That initial index is stored
2560  *		in this field. Once it is equal to q->num_buffers all
2561  *		available buffers have been queued and __vb2_perform_fileio()
2562  *		should start the normal dequeue/queue cycle.
2563  *
2564  * vb2 provides a compatibility layer and emulator of file io (read and
2565  * write) calls on top of streaming API. For proper operation it required
2566  * this structure to save the driver state between each call of the read
2567  * or write function.
2568  */
2569 struct vb2_fileio_data {
2570 	unsigned int count;
2571 	unsigned int type;
2572 	unsigned int memory;
2573 	struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2574 	unsigned int cur_index;
2575 	unsigned int initial_index;
2576 	unsigned int q_count;
2577 	unsigned int dq_count;
2578 	unsigned read_once:1;
2579 	unsigned write_immediately:1;
2580 };
2581 
2582 /*
2583  * __vb2_init_fileio() - initialize file io emulator
2584  * @q:		videobuf2 queue
2585  * @read:	mode selector (1 means read, 0 means write)
2586  */
2587 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2588 {
2589 	struct vb2_fileio_data *fileio;
2590 	int i, ret;
2591 	unsigned int count = 0;
2592 
2593 	/*
2594 	 * Sanity check
2595 	 */
2596 	if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2597 		    (!read && !(q->io_modes & VB2_WRITE))))
2598 		return -EINVAL;
2599 
2600 	/*
2601 	 * Check if device supports mapping buffers to kernel virtual space.
2602 	 */
2603 	if (!q->mem_ops->vaddr)
2604 		return -EBUSY;
2605 
2606 	/*
2607 	 * Check if streaming api has not been already activated.
2608 	 */
2609 	if (q->streaming || q->num_buffers > 0)
2610 		return -EBUSY;
2611 
2612 	/*
2613 	 * Start with count 1, driver can increase it in queue_setup()
2614 	 */
2615 	count = 1;
2616 
2617 	dprintk(q, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2618 		(read) ? "read" : "write", count, q->fileio_read_once,
2619 		q->fileio_write_immediately);
2620 
2621 	fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2622 	if (fileio == NULL)
2623 		return -ENOMEM;
2624 
2625 	fileio->read_once = q->fileio_read_once;
2626 	fileio->write_immediately = q->fileio_write_immediately;
2627 
2628 	/*
2629 	 * Request buffers and use MMAP type to force driver
2630 	 * to allocate buffers by itself.
2631 	 */
2632 	fileio->count = count;
2633 	fileio->memory = VB2_MEMORY_MMAP;
2634 	fileio->type = q->type;
2635 	q->fileio = fileio;
2636 	ret = vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2637 	if (ret)
2638 		goto err_kfree;
2639 
2640 	/*
2641 	 * Check if plane_count is correct
2642 	 * (multiplane buffers are not supported).
2643 	 */
2644 	if (q->bufs[0]->num_planes != 1) {
2645 		ret = -EBUSY;
2646 		goto err_reqbufs;
2647 	}
2648 
2649 	/*
2650 	 * Get kernel address of each buffer.
2651 	 */
2652 	for (i = 0; i < q->num_buffers; i++) {
2653 		fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2654 		if (fileio->bufs[i].vaddr == NULL) {
2655 			ret = -EINVAL;
2656 			goto err_reqbufs;
2657 		}
2658 		fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2659 	}
2660 
2661 	/*
2662 	 * Read mode requires pre queuing of all buffers.
2663 	 */
2664 	if (read) {
2665 		/*
2666 		 * Queue all buffers.
2667 		 */
2668 		for (i = 0; i < q->num_buffers; i++) {
2669 			ret = vb2_core_qbuf(q, i, NULL, NULL);
2670 			if (ret)
2671 				goto err_reqbufs;
2672 			fileio->bufs[i].queued = 1;
2673 		}
2674 		/*
2675 		 * All buffers have been queued, so mark that by setting
2676 		 * initial_index to q->num_buffers
2677 		 */
2678 		fileio->initial_index = q->num_buffers;
2679 		fileio->cur_index = q->num_buffers;
2680 	}
2681 
2682 	/*
2683 	 * Start streaming.
2684 	 */
2685 	ret = vb2_core_streamon(q, q->type);
2686 	if (ret)
2687 		goto err_reqbufs;
2688 
2689 	return ret;
2690 
2691 err_reqbufs:
2692 	fileio->count = 0;
2693 	vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2694 
2695 err_kfree:
2696 	q->fileio = NULL;
2697 	kfree(fileio);
2698 	return ret;
2699 }
2700 
2701 /*
2702  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2703  * @q:		videobuf2 queue
2704  */
2705 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2706 {
2707 	struct vb2_fileio_data *fileio = q->fileio;
2708 
2709 	if (fileio) {
2710 		vb2_core_streamoff(q, q->type);
2711 		q->fileio = NULL;
2712 		fileio->count = 0;
2713 		vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
2714 		kfree(fileio);
2715 		dprintk(q, 3, "file io emulator closed\n");
2716 	}
2717 	return 0;
2718 }
2719 
2720 /*
2721  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2722  * @q:		videobuf2 queue
2723  * @data:	pointed to target userspace buffer
2724  * @count:	number of bytes to read or write
2725  * @ppos:	file handle position tracking pointer
2726  * @nonblock:	mode selector (1 means blocking calls, 0 means nonblocking)
2727  * @read:	access mode selector (1 means read, 0 means write)
2728  */
2729 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2730 		loff_t *ppos, int nonblock, int read)
2731 {
2732 	struct vb2_fileio_data *fileio;
2733 	struct vb2_fileio_buf *buf;
2734 	bool is_multiplanar = q->is_multiplanar;
2735 	/*
2736 	 * When using write() to write data to an output video node the vb2 core
2737 	 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2738 	 * else is able to provide this information with the write() operation.
2739 	 */
2740 	bool copy_timestamp = !read && q->copy_timestamp;
2741 	unsigned index;
2742 	int ret;
2743 
2744 	dprintk(q, 3, "mode %s, offset %ld, count %zd, %sblocking\n",
2745 		read ? "read" : "write", (long)*ppos, count,
2746 		nonblock ? "non" : "");
2747 
2748 	if (!data)
2749 		return -EINVAL;
2750 
2751 	if (q->waiting_in_dqbuf) {
2752 		dprintk(q, 3, "another dup()ped fd is %s\n",
2753 			read ? "reading" : "writing");
2754 		return -EBUSY;
2755 	}
2756 
2757 	/*
2758 	 * Initialize emulator on first call.
2759 	 */
2760 	if (!vb2_fileio_is_active(q)) {
2761 		ret = __vb2_init_fileio(q, read);
2762 		dprintk(q, 3, "vb2_init_fileio result: %d\n", ret);
2763 		if (ret)
2764 			return ret;
2765 	}
2766 	fileio = q->fileio;
2767 
2768 	/*
2769 	 * Check if we need to dequeue the buffer.
2770 	 */
2771 	index = fileio->cur_index;
2772 	if (index >= q->num_buffers) {
2773 		struct vb2_buffer *b;
2774 
2775 		/*
2776 		 * Call vb2_dqbuf to get buffer back.
2777 		 */
2778 		ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2779 		dprintk(q, 5, "vb2_dqbuf result: %d\n", ret);
2780 		if (ret)
2781 			return ret;
2782 		fileio->dq_count += 1;
2783 
2784 		fileio->cur_index = index;
2785 		buf = &fileio->bufs[index];
2786 		b = q->bufs[index];
2787 
2788 		/*
2789 		 * Get number of bytes filled by the driver
2790 		 */
2791 		buf->pos = 0;
2792 		buf->queued = 0;
2793 		buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2794 				 : vb2_plane_size(q->bufs[index], 0);
2795 		/* Compensate for data_offset on read in the multiplanar case. */
2796 		if (is_multiplanar && read &&
2797 				b->planes[0].data_offset < buf->size) {
2798 			buf->pos = b->planes[0].data_offset;
2799 			buf->size -= buf->pos;
2800 		}
2801 	} else {
2802 		buf = &fileio->bufs[index];
2803 	}
2804 
2805 	/*
2806 	 * Limit count on last few bytes of the buffer.
2807 	 */
2808 	if (buf->pos + count > buf->size) {
2809 		count = buf->size - buf->pos;
2810 		dprintk(q, 5, "reducing read count: %zd\n", count);
2811 	}
2812 
2813 	/*
2814 	 * Transfer data to userspace.
2815 	 */
2816 	dprintk(q, 3, "copying %zd bytes - buffer %d, offset %u\n",
2817 		count, index, buf->pos);
2818 	if (read)
2819 		ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2820 	else
2821 		ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2822 	if (ret) {
2823 		dprintk(q, 3, "error copying data\n");
2824 		return -EFAULT;
2825 	}
2826 
2827 	/*
2828 	 * Update counters.
2829 	 */
2830 	buf->pos += count;
2831 	*ppos += count;
2832 
2833 	/*
2834 	 * Queue next buffer if required.
2835 	 */
2836 	if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2837 		struct vb2_buffer *b = q->bufs[index];
2838 
2839 		/*
2840 		 * Check if this is the last buffer to read.
2841 		 */
2842 		if (read && fileio->read_once && fileio->dq_count == 1) {
2843 			dprintk(q, 3, "read limit reached\n");
2844 			return __vb2_cleanup_fileio(q);
2845 		}
2846 
2847 		/*
2848 		 * Call vb2_qbuf and give buffer to the driver.
2849 		 */
2850 		b->planes[0].bytesused = buf->pos;
2851 
2852 		if (copy_timestamp)
2853 			b->timestamp = ktime_get_ns();
2854 		ret = vb2_core_qbuf(q, index, NULL, NULL);
2855 		dprintk(q, 5, "vb2_dbuf result: %d\n", ret);
2856 		if (ret)
2857 			return ret;
2858 
2859 		/*
2860 		 * Buffer has been queued, update the status
2861 		 */
2862 		buf->pos = 0;
2863 		buf->queued = 1;
2864 		buf->size = vb2_plane_size(q->bufs[index], 0);
2865 		fileio->q_count += 1;
2866 		/*
2867 		 * If we are queuing up buffers for the first time, then
2868 		 * increase initial_index by one.
2869 		 */
2870 		if (fileio->initial_index < q->num_buffers)
2871 			fileio->initial_index++;
2872 		/*
2873 		 * The next buffer to use is either a buffer that's going to be
2874 		 * queued for the first time (initial_index < q->num_buffers)
2875 		 * or it is equal to q->num_buffers, meaning that the next
2876 		 * time we need to dequeue a buffer since we've now queued up
2877 		 * all the 'first time' buffers.
2878 		 */
2879 		fileio->cur_index = fileio->initial_index;
2880 	}
2881 
2882 	/*
2883 	 * Return proper number of bytes processed.
2884 	 */
2885 	if (ret == 0)
2886 		ret = count;
2887 	return ret;
2888 }
2889 
2890 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2891 		loff_t *ppos, int nonblocking)
2892 {
2893 	return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2894 }
2895 EXPORT_SYMBOL_GPL(vb2_read);
2896 
2897 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2898 		loff_t *ppos, int nonblocking)
2899 {
2900 	return __vb2_perform_fileio(q, (char __user *) data, count,
2901 							ppos, nonblocking, 0);
2902 }
2903 EXPORT_SYMBOL_GPL(vb2_write);
2904 
2905 struct vb2_threadio_data {
2906 	struct task_struct *thread;
2907 	vb2_thread_fnc fnc;
2908 	void *priv;
2909 	bool stop;
2910 };
2911 
2912 static int vb2_thread(void *data)
2913 {
2914 	struct vb2_queue *q = data;
2915 	struct vb2_threadio_data *threadio = q->threadio;
2916 	bool copy_timestamp = false;
2917 	unsigned prequeue = 0;
2918 	unsigned index = 0;
2919 	int ret = 0;
2920 
2921 	if (q->is_output) {
2922 		prequeue = q->num_buffers;
2923 		copy_timestamp = q->copy_timestamp;
2924 	}
2925 
2926 	set_freezable();
2927 
2928 	for (;;) {
2929 		struct vb2_buffer *vb;
2930 
2931 		/*
2932 		 * Call vb2_dqbuf to get buffer back.
2933 		 */
2934 		if (prequeue) {
2935 			vb = q->bufs[index++];
2936 			prequeue--;
2937 		} else {
2938 			call_void_qop(q, wait_finish, q);
2939 			if (!threadio->stop)
2940 				ret = vb2_core_dqbuf(q, &index, NULL, 0);
2941 			call_void_qop(q, wait_prepare, q);
2942 			dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
2943 			if (!ret)
2944 				vb = q->bufs[index];
2945 		}
2946 		if (ret || threadio->stop)
2947 			break;
2948 		try_to_freeze();
2949 
2950 		if (vb->state != VB2_BUF_STATE_ERROR)
2951 			if (threadio->fnc(vb, threadio->priv))
2952 				break;
2953 		call_void_qop(q, wait_finish, q);
2954 		if (copy_timestamp)
2955 			vb->timestamp = ktime_get_ns();
2956 		if (!threadio->stop)
2957 			ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
2958 		call_void_qop(q, wait_prepare, q);
2959 		if (ret || threadio->stop)
2960 			break;
2961 	}
2962 
2963 	/* Hmm, linux becomes *very* unhappy without this ... */
2964 	while (!kthread_should_stop()) {
2965 		set_current_state(TASK_INTERRUPTIBLE);
2966 		schedule();
2967 	}
2968 	return 0;
2969 }
2970 
2971 /*
2972  * This function should not be used for anything else but the videobuf2-dvb
2973  * support. If you think you have another good use-case for this, then please
2974  * contact the linux-media mailinglist first.
2975  */
2976 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2977 		     const char *thread_name)
2978 {
2979 	struct vb2_threadio_data *threadio;
2980 	int ret = 0;
2981 
2982 	if (q->threadio)
2983 		return -EBUSY;
2984 	if (vb2_is_busy(q))
2985 		return -EBUSY;
2986 	if (WARN_ON(q->fileio))
2987 		return -EBUSY;
2988 
2989 	threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2990 	if (threadio == NULL)
2991 		return -ENOMEM;
2992 	threadio->fnc = fnc;
2993 	threadio->priv = priv;
2994 
2995 	ret = __vb2_init_fileio(q, !q->is_output);
2996 	dprintk(q, 3, "file io: vb2_init_fileio result: %d\n", ret);
2997 	if (ret)
2998 		goto nomem;
2999 	q->threadio = threadio;
3000 	threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
3001 	if (IS_ERR(threadio->thread)) {
3002 		ret = PTR_ERR(threadio->thread);
3003 		threadio->thread = NULL;
3004 		goto nothread;
3005 	}
3006 	return 0;
3007 
3008 nothread:
3009 	__vb2_cleanup_fileio(q);
3010 nomem:
3011 	kfree(threadio);
3012 	return ret;
3013 }
3014 EXPORT_SYMBOL_GPL(vb2_thread_start);
3015 
3016 int vb2_thread_stop(struct vb2_queue *q)
3017 {
3018 	struct vb2_threadio_data *threadio = q->threadio;
3019 	int err;
3020 
3021 	if (threadio == NULL)
3022 		return 0;
3023 	threadio->stop = true;
3024 	/* Wake up all pending sleeps in the thread */
3025 	vb2_queue_error(q);
3026 	err = kthread_stop(threadio->thread);
3027 	__vb2_cleanup_fileio(q);
3028 	threadio->thread = NULL;
3029 	kfree(threadio);
3030 	q->threadio = NULL;
3031 	return err;
3032 }
3033 EXPORT_SYMBOL_GPL(vb2_thread_stop);
3034 
3035 MODULE_DESCRIPTION("Media buffer core framework");
3036 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3037 MODULE_LICENSE("GPL");
3038 MODULE_IMPORT_NS(DMA_BUF);
3039