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(vb, op, 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(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(vb, op, args...)					\
148 	((vb)->vb2_queue->mem_ops->op ?					\
149 		(vb)->vb2_queue->mem_ops->op(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(vb, alloc,
234 				q->alloc_devs[plane] ? : q->dev,
235 				q->dma_attrs, size, q->dma_dir, q->gfp_flags);
236 		if (IS_ERR_OR_NULL(mem_priv)) {
237 			if (mem_priv)
238 				ret = PTR_ERR(mem_priv);
239 			goto free;
240 		}
241 
242 		/* Associate allocator private data with this plane */
243 		vb->planes[plane].mem_priv = mem_priv;
244 	}
245 
246 	return 0;
247 free:
248 	/* Free already allocated memory if one of the allocations failed */
249 	for (; plane > 0; --plane) {
250 		call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
251 		vb->planes[plane - 1].mem_priv = NULL;
252 	}
253 
254 	return ret;
255 }
256 
257 /*
258  * __vb2_buf_mem_free() - free memory of the given buffer
259  */
260 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
261 {
262 	unsigned int plane;
263 
264 	for (plane = 0; plane < vb->num_planes; ++plane) {
265 		call_void_memop(vb, put, vb->planes[plane].mem_priv);
266 		vb->planes[plane].mem_priv = NULL;
267 		dprintk(vb->vb2_queue, 3, "freed plane %d of buffer %d\n",
268 			plane, vb->index);
269 	}
270 }
271 
272 /*
273  * __vb2_buf_userptr_put() - release userspace memory associated with
274  * a USERPTR buffer
275  */
276 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
277 {
278 	unsigned int plane;
279 
280 	for (plane = 0; plane < vb->num_planes; ++plane) {
281 		if (vb->planes[plane].mem_priv)
282 			call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
283 		vb->planes[plane].mem_priv = NULL;
284 	}
285 }
286 
287 /*
288  * __vb2_plane_dmabuf_put() - release memory associated with
289  * a DMABUF shared plane
290  */
291 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
292 {
293 	if (!p->mem_priv)
294 		return;
295 
296 	if (p->dbuf_mapped)
297 		call_void_memop(vb, unmap_dmabuf, p->mem_priv);
298 
299 	call_void_memop(vb, detach_dmabuf, p->mem_priv);
300 	dma_buf_put(p->dbuf);
301 	p->mem_priv = NULL;
302 	p->dbuf = NULL;
303 	p->dbuf_mapped = 0;
304 }
305 
306 /*
307  * __vb2_buf_dmabuf_put() - release memory associated with
308  * a DMABUF shared buffer
309  */
310 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
311 {
312 	unsigned int plane;
313 
314 	for (plane = 0; plane < vb->num_planes; ++plane)
315 		__vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
316 }
317 
318 /*
319  * __vb2_buf_mem_prepare() - call ->prepare() on buffer's private memory
320  * to sync caches
321  */
322 static void __vb2_buf_mem_prepare(struct vb2_buffer *vb)
323 {
324 	unsigned int plane;
325 
326 	if (vb->synced)
327 		return;
328 
329 	if (vb->need_cache_sync_on_prepare) {
330 		for (plane = 0; plane < vb->num_planes; ++plane)
331 			call_void_memop(vb, prepare,
332 					vb->planes[plane].mem_priv);
333 	}
334 	vb->synced = 1;
335 }
336 
337 /*
338  * __vb2_buf_mem_finish() - call ->finish on buffer's private memory
339  * to sync caches
340  */
341 static void __vb2_buf_mem_finish(struct vb2_buffer *vb)
342 {
343 	unsigned int plane;
344 
345 	if (!vb->synced)
346 		return;
347 
348 	if (vb->need_cache_sync_on_finish) {
349 		for (plane = 0; plane < vb->num_planes; ++plane)
350 			call_void_memop(vb, finish,
351 					vb->planes[plane].mem_priv);
352 	}
353 	vb->synced = 0;
354 }
355 
356 /*
357  * __setup_offsets() - setup unique offsets ("cookies") for every plane in
358  * the buffer.
359  */
360 static void __setup_offsets(struct vb2_buffer *vb)
361 {
362 	struct vb2_queue *q = vb->vb2_queue;
363 	unsigned int plane;
364 	unsigned long off = 0;
365 
366 	if (vb->index) {
367 		struct vb2_buffer *prev = q->bufs[vb->index - 1];
368 		struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
369 
370 		off = PAGE_ALIGN(p->m.offset + p->length);
371 	}
372 
373 	for (plane = 0; plane < vb->num_planes; ++plane) {
374 		vb->planes[plane].m.offset = off;
375 
376 		dprintk(q, 3, "buffer %d, plane %d offset 0x%08lx\n",
377 				vb->index, plane, off);
378 
379 		off += vb->planes[plane].length;
380 		off = PAGE_ALIGN(off);
381 	}
382 }
383 
384 /*
385  * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
386  * video buffer memory for all buffers/planes on the queue and initializes the
387  * queue
388  *
389  * Returns the number of buffers successfully allocated.
390  */
391 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
392 			     unsigned int num_buffers, unsigned int num_planes,
393 			     const unsigned plane_sizes[VB2_MAX_PLANES])
394 {
395 	unsigned int buffer, plane;
396 	struct vb2_buffer *vb;
397 	int ret;
398 
399 	/* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
400 	num_buffers = min_t(unsigned int, num_buffers,
401 			    VB2_MAX_FRAME - q->num_buffers);
402 
403 	for (buffer = 0; buffer < num_buffers; ++buffer) {
404 		/* Allocate videobuf buffer structures */
405 		vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
406 		if (!vb) {
407 			dprintk(q, 1, "memory alloc for buffer struct failed\n");
408 			break;
409 		}
410 
411 		vb->state = VB2_BUF_STATE_DEQUEUED;
412 		vb->vb2_queue = q;
413 		vb->num_planes = num_planes;
414 		vb->index = q->num_buffers + buffer;
415 		vb->type = q->type;
416 		vb->memory = memory;
417 		/*
418 		 * We need to set these flags here so that the videobuf2 core
419 		 * will call ->prepare()/->finish() cache sync/flush on vb2
420 		 * buffers when appropriate. However, we can avoid explicit
421 		 * ->prepare() and ->finish() cache sync for DMABUF buffers,
422 		 * because DMA exporter takes care of it.
423 		 */
424 		if (q->memory != VB2_MEMORY_DMABUF) {
425 			vb->need_cache_sync_on_prepare = 1;
426 			vb->need_cache_sync_on_finish = 1;
427 		}
428 		for (plane = 0; plane < num_planes; ++plane) {
429 			vb->planes[plane].length = plane_sizes[plane];
430 			vb->planes[plane].min_length = plane_sizes[plane];
431 		}
432 		call_void_bufop(q, init_buffer, vb);
433 
434 		q->bufs[vb->index] = vb;
435 
436 		/* Allocate video buffer memory for the MMAP type */
437 		if (memory == VB2_MEMORY_MMAP) {
438 			ret = __vb2_buf_mem_alloc(vb);
439 			if (ret) {
440 				dprintk(q, 1, "failed allocating memory for buffer %d\n",
441 					buffer);
442 				q->bufs[vb->index] = NULL;
443 				kfree(vb);
444 				break;
445 			}
446 			__setup_offsets(vb);
447 			/*
448 			 * Call the driver-provided buffer initialization
449 			 * callback, if given. An error in initialization
450 			 * results in queue setup failure.
451 			 */
452 			ret = call_vb_qop(vb, buf_init, vb);
453 			if (ret) {
454 				dprintk(q, 1, "buffer %d %p initialization failed\n",
455 					buffer, vb);
456 				__vb2_buf_mem_free(vb);
457 				q->bufs[vb->index] = NULL;
458 				kfree(vb);
459 				break;
460 			}
461 		}
462 	}
463 
464 	dprintk(q, 3, "allocated %d buffers, %d plane(s) each\n",
465 		buffer, num_planes);
466 
467 	return buffer;
468 }
469 
470 /*
471  * __vb2_free_mem() - release all video buffer memory for a given queue
472  */
473 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
474 {
475 	unsigned int buffer;
476 	struct vb2_buffer *vb;
477 
478 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
479 	     ++buffer) {
480 		vb = q->bufs[buffer];
481 		if (!vb)
482 			continue;
483 
484 		/* Free MMAP buffers or release USERPTR buffers */
485 		if (q->memory == VB2_MEMORY_MMAP)
486 			__vb2_buf_mem_free(vb);
487 		else if (q->memory == VB2_MEMORY_DMABUF)
488 			__vb2_buf_dmabuf_put(vb);
489 		else
490 			__vb2_buf_userptr_put(vb);
491 	}
492 }
493 
494 /*
495  * __vb2_queue_free() - free buffers at the end of the queue - video memory and
496  * related information, if no buffers are left return the queue to an
497  * uninitialized state. Might be called even if the queue has already been freed.
498  */
499 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
500 {
501 	unsigned int buffer;
502 
503 	/*
504 	 * Sanity check: when preparing a buffer the queue lock is released for
505 	 * a short while (see __buf_prepare for the details), which would allow
506 	 * a race with a reqbufs which can call this function. Removing the
507 	 * buffers from underneath __buf_prepare is obviously a bad idea, so we
508 	 * check if any of the buffers is in the state PREPARING, and if so we
509 	 * just return -EAGAIN.
510 	 */
511 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
512 	     ++buffer) {
513 		if (q->bufs[buffer] == NULL)
514 			continue;
515 		if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
516 			dprintk(q, 1, "preparing buffers, cannot free\n");
517 			return -EAGAIN;
518 		}
519 	}
520 
521 	/* Call driver-provided cleanup function for each buffer, if provided */
522 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
523 	     ++buffer) {
524 		struct vb2_buffer *vb = q->bufs[buffer];
525 
526 		if (vb && vb->planes[0].mem_priv)
527 			call_void_vb_qop(vb, buf_cleanup, vb);
528 	}
529 
530 	/* Release video buffer memory */
531 	__vb2_free_mem(q, buffers);
532 
533 #ifdef CONFIG_VIDEO_ADV_DEBUG
534 	/*
535 	 * Check that all the calls were balances during the life-time of this
536 	 * queue. If not (or if the debug level is 1 or up), then dump the
537 	 * counters to the kernel log.
538 	 */
539 	if (q->num_buffers) {
540 		bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
541 				  q->cnt_wait_prepare != q->cnt_wait_finish;
542 
543 		if (unbalanced || debug) {
544 			pr_info("counters for queue %p:%s\n", q,
545 				unbalanced ? " UNBALANCED!" : "");
546 			pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
547 				q->cnt_queue_setup, q->cnt_start_streaming,
548 				q->cnt_stop_streaming);
549 			pr_info("     wait_prepare: %u wait_finish: %u\n",
550 				q->cnt_wait_prepare, q->cnt_wait_finish);
551 		}
552 		q->cnt_queue_setup = 0;
553 		q->cnt_wait_prepare = 0;
554 		q->cnt_wait_finish = 0;
555 		q->cnt_start_streaming = 0;
556 		q->cnt_stop_streaming = 0;
557 	}
558 	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
559 		struct vb2_buffer *vb = q->bufs[buffer];
560 		bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
561 				  vb->cnt_mem_prepare != vb->cnt_mem_finish ||
562 				  vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
563 				  vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
564 				  vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
565 				  vb->cnt_buf_queue != vb->cnt_buf_done ||
566 				  vb->cnt_buf_prepare != vb->cnt_buf_finish ||
567 				  vb->cnt_buf_init != vb->cnt_buf_cleanup;
568 
569 		if (unbalanced || debug) {
570 			pr_info("   counters for queue %p, buffer %d:%s\n",
571 				q, buffer, unbalanced ? " UNBALANCED!" : "");
572 			pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
573 				vb->cnt_buf_init, vb->cnt_buf_cleanup,
574 				vb->cnt_buf_prepare, vb->cnt_buf_finish);
575 			pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
576 				vb->cnt_buf_out_validate, vb->cnt_buf_queue,
577 				vb->cnt_buf_done, vb->cnt_buf_request_complete);
578 			pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
579 				vb->cnt_mem_alloc, vb->cnt_mem_put,
580 				vb->cnt_mem_prepare, vb->cnt_mem_finish,
581 				vb->cnt_mem_mmap);
582 			pr_info("     get_userptr: %u put_userptr: %u\n",
583 				vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
584 			pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
585 				vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
586 				vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
587 			pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
588 				vb->cnt_mem_get_dmabuf,
589 				vb->cnt_mem_num_users,
590 				vb->cnt_mem_vaddr,
591 				vb->cnt_mem_cookie);
592 		}
593 	}
594 #endif
595 
596 	/* Free videobuf buffers */
597 	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
598 	     ++buffer) {
599 		kfree(q->bufs[buffer]);
600 		q->bufs[buffer] = NULL;
601 	}
602 
603 	q->num_buffers -= buffers;
604 	if (!q->num_buffers) {
605 		q->memory = VB2_MEMORY_UNKNOWN;
606 		INIT_LIST_HEAD(&q->queued_list);
607 	}
608 	return 0;
609 }
610 
611 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
612 {
613 	unsigned int plane;
614 	for (plane = 0; plane < vb->num_planes; ++plane) {
615 		void *mem_priv = vb->planes[plane].mem_priv;
616 		/*
617 		 * If num_users() has not been provided, call_memop
618 		 * will return 0, apparently nobody cares about this
619 		 * case anyway. If num_users() returns more than 1,
620 		 * we are not the only user of the plane's memory.
621 		 */
622 		if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
623 			return true;
624 	}
625 	return false;
626 }
627 EXPORT_SYMBOL(vb2_buffer_in_use);
628 
629 /*
630  * __buffers_in_use() - return true if any buffers on the queue are in use and
631  * the queue cannot be freed (by the means of REQBUFS(0)) call
632  */
633 static bool __buffers_in_use(struct vb2_queue *q)
634 {
635 	unsigned int buffer;
636 	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
637 		if (vb2_buffer_in_use(q, q->bufs[buffer]))
638 			return true;
639 	}
640 	return false;
641 }
642 
643 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
644 {
645 	call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
646 }
647 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
648 
649 /*
650  * __verify_userptr_ops() - verify that all memory operations required for
651  * USERPTR queue type have been provided
652  */
653 static int __verify_userptr_ops(struct vb2_queue *q)
654 {
655 	if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
656 	    !q->mem_ops->put_userptr)
657 		return -EINVAL;
658 
659 	return 0;
660 }
661 
662 /*
663  * __verify_mmap_ops() - verify that all memory operations required for
664  * MMAP queue type have been provided
665  */
666 static int __verify_mmap_ops(struct vb2_queue *q)
667 {
668 	if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
669 	    !q->mem_ops->put || !q->mem_ops->mmap)
670 		return -EINVAL;
671 
672 	return 0;
673 }
674 
675 /*
676  * __verify_dmabuf_ops() - verify that all memory operations required for
677  * DMABUF queue type have been provided
678  */
679 static int __verify_dmabuf_ops(struct vb2_queue *q)
680 {
681 	if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
682 	    !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
683 	    !q->mem_ops->unmap_dmabuf)
684 		return -EINVAL;
685 
686 	return 0;
687 }
688 
689 int vb2_verify_memory_type(struct vb2_queue *q,
690 		enum vb2_memory memory, unsigned int type)
691 {
692 	if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
693 	    memory != VB2_MEMORY_DMABUF) {
694 		dprintk(q, 1, "unsupported memory type\n");
695 		return -EINVAL;
696 	}
697 
698 	if (type != q->type) {
699 		dprintk(q, 1, "requested type is incorrect\n");
700 		return -EINVAL;
701 	}
702 
703 	/*
704 	 * Make sure all the required memory ops for given memory type
705 	 * are available.
706 	 */
707 	if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
708 		dprintk(q, 1, "MMAP for current setup unsupported\n");
709 		return -EINVAL;
710 	}
711 
712 	if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
713 		dprintk(q, 1, "USERPTR for current setup unsupported\n");
714 		return -EINVAL;
715 	}
716 
717 	if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
718 		dprintk(q, 1, "DMABUF for current setup unsupported\n");
719 		return -EINVAL;
720 	}
721 
722 	/*
723 	 * Place the busy tests at the end: -EBUSY can be ignored when
724 	 * create_bufs is called with count == 0, but count == 0 should still
725 	 * do the memory and type validation.
726 	 */
727 	if (vb2_fileio_is_active(q)) {
728 		dprintk(q, 1, "file io in progress\n");
729 		return -EBUSY;
730 	}
731 	return 0;
732 }
733 EXPORT_SYMBOL(vb2_verify_memory_type);
734 
735 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
736 		     unsigned int *count)
737 {
738 	unsigned int num_buffers, allocated_buffers, num_planes = 0;
739 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
740 	unsigned int i;
741 	int ret;
742 
743 	if (q->streaming) {
744 		dprintk(q, 1, "streaming active\n");
745 		return -EBUSY;
746 	}
747 
748 	if (q->waiting_in_dqbuf && *count) {
749 		dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
750 		return -EBUSY;
751 	}
752 
753 	if (*count == 0 || q->num_buffers != 0 ||
754 	    (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory)) {
755 		/*
756 		 * We already have buffers allocated, so first check if they
757 		 * are not in use and can be freed.
758 		 */
759 		mutex_lock(&q->mmap_lock);
760 		if (debug && q->memory == VB2_MEMORY_MMAP &&
761 		    __buffers_in_use(q))
762 			dprintk(q, 1, "memory in use, orphaning buffers\n");
763 
764 		/*
765 		 * Call queue_cancel to clean up any buffers in the
766 		 * QUEUED state which is possible if buffers were prepared or
767 		 * queued without ever calling STREAMON.
768 		 */
769 		__vb2_queue_cancel(q);
770 		ret = __vb2_queue_free(q, q->num_buffers);
771 		mutex_unlock(&q->mmap_lock);
772 		if (ret)
773 			return ret;
774 
775 		/*
776 		 * In case of REQBUFS(0) return immediately without calling
777 		 * driver's queue_setup() callback and allocating resources.
778 		 */
779 		if (*count == 0)
780 			return 0;
781 	}
782 
783 	/*
784 	 * Make sure the requested values and current defaults are sane.
785 	 */
786 	WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
787 	num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
788 	num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
789 	memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
790 	q->memory = memory;
791 
792 	/*
793 	 * Ask the driver how many buffers and planes per buffer it requires.
794 	 * Driver also sets the size and allocator context for each plane.
795 	 */
796 	ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
797 		       plane_sizes, q->alloc_devs);
798 	if (ret)
799 		return ret;
800 
801 	/* Check that driver has set sane values */
802 	if (WARN_ON(!num_planes))
803 		return -EINVAL;
804 
805 	for (i = 0; i < num_planes; i++)
806 		if (WARN_ON(!plane_sizes[i]))
807 			return -EINVAL;
808 
809 	/* Finally, allocate buffers and video memory */
810 	allocated_buffers =
811 		__vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
812 	if (allocated_buffers == 0) {
813 		dprintk(q, 1, "memory allocation failed\n");
814 		return -ENOMEM;
815 	}
816 
817 	/*
818 	 * There is no point in continuing if we can't allocate the minimum
819 	 * number of buffers needed by this vb2_queue.
820 	 */
821 	if (allocated_buffers < q->min_buffers_needed)
822 		ret = -ENOMEM;
823 
824 	/*
825 	 * Check if driver can handle the allocated number of buffers.
826 	 */
827 	if (!ret && allocated_buffers < num_buffers) {
828 		num_buffers = allocated_buffers;
829 		/*
830 		 * num_planes is set by the previous queue_setup(), but since it
831 		 * signals to queue_setup() whether it is called from create_bufs()
832 		 * vs reqbufs() we zero it here to signal that queue_setup() is
833 		 * called for the reqbufs() case.
834 		 */
835 		num_planes = 0;
836 
837 		ret = call_qop(q, queue_setup, q, &num_buffers,
838 			       &num_planes, plane_sizes, q->alloc_devs);
839 
840 		if (!ret && allocated_buffers < num_buffers)
841 			ret = -ENOMEM;
842 
843 		/*
844 		 * Either the driver has accepted a smaller number of buffers,
845 		 * or .queue_setup() returned an error
846 		 */
847 	}
848 
849 	mutex_lock(&q->mmap_lock);
850 	q->num_buffers = allocated_buffers;
851 
852 	if (ret < 0) {
853 		/*
854 		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
855 		 * from q->num_buffers.
856 		 */
857 		__vb2_queue_free(q, allocated_buffers);
858 		mutex_unlock(&q->mmap_lock);
859 		return ret;
860 	}
861 	mutex_unlock(&q->mmap_lock);
862 
863 	/*
864 	 * Return the number of successfully allocated buffers
865 	 * to the userspace.
866 	 */
867 	*count = allocated_buffers;
868 	q->waiting_for_buffers = !q->is_output;
869 
870 	return 0;
871 }
872 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
873 
874 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
875 			 unsigned int *count,
876 			 unsigned int requested_planes,
877 			 const unsigned int requested_sizes[])
878 {
879 	unsigned int num_planes = 0, num_buffers, allocated_buffers;
880 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
881 	int ret;
882 
883 	if (q->num_buffers == VB2_MAX_FRAME) {
884 		dprintk(q, 1, "maximum number of buffers already allocated\n");
885 		return -ENOBUFS;
886 	}
887 
888 	if (!q->num_buffers) {
889 		if (q->waiting_in_dqbuf && *count) {
890 			dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
891 			return -EBUSY;
892 		}
893 		memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
894 		q->memory = memory;
895 		q->waiting_for_buffers = !q->is_output;
896 	} else {
897 		if (q->memory != memory) {
898 			dprintk(q, 1, "memory model mismatch\n");
899 			return -EINVAL;
900 		}
901 	}
902 
903 	num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
904 
905 	if (requested_planes && requested_sizes) {
906 		num_planes = requested_planes;
907 		memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
908 	}
909 
910 	/*
911 	 * Ask the driver, whether the requested number of buffers, planes per
912 	 * buffer and their sizes are acceptable
913 	 */
914 	ret = call_qop(q, queue_setup, q, &num_buffers,
915 		       &num_planes, plane_sizes, q->alloc_devs);
916 	if (ret)
917 		return ret;
918 
919 	/* Finally, allocate buffers and video memory */
920 	allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
921 				num_planes, plane_sizes);
922 	if (allocated_buffers == 0) {
923 		dprintk(q, 1, "memory allocation failed\n");
924 		return -ENOMEM;
925 	}
926 
927 	/*
928 	 * Check if driver can handle the so far allocated number of buffers.
929 	 */
930 	if (allocated_buffers < num_buffers) {
931 		num_buffers = allocated_buffers;
932 
933 		/*
934 		 * q->num_buffers contains the total number of buffers, that the
935 		 * queue driver has set up
936 		 */
937 		ret = call_qop(q, queue_setup, q, &num_buffers,
938 			       &num_planes, plane_sizes, q->alloc_devs);
939 
940 		if (!ret && allocated_buffers < num_buffers)
941 			ret = -ENOMEM;
942 
943 		/*
944 		 * Either the driver has accepted a smaller number of buffers,
945 		 * or .queue_setup() returned an error
946 		 */
947 	}
948 
949 	mutex_lock(&q->mmap_lock);
950 	q->num_buffers += allocated_buffers;
951 
952 	if (ret < 0) {
953 		/*
954 		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
955 		 * from q->num_buffers.
956 		 */
957 		__vb2_queue_free(q, allocated_buffers);
958 		mutex_unlock(&q->mmap_lock);
959 		return -ENOMEM;
960 	}
961 	mutex_unlock(&q->mmap_lock);
962 
963 	/*
964 	 * Return the number of successfully allocated buffers
965 	 * to the userspace.
966 	 */
967 	*count = allocated_buffers;
968 
969 	return 0;
970 }
971 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
972 
973 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
974 {
975 	if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
976 		return NULL;
977 
978 	return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
979 
980 }
981 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
982 
983 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
984 {
985 	if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
986 		return NULL;
987 
988 	return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
989 }
990 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
991 
992 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
993 {
994 	struct vb2_queue *q = vb->vb2_queue;
995 	unsigned long flags;
996 
997 	if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
998 		return;
999 
1000 	if (WARN_ON(state != VB2_BUF_STATE_DONE &&
1001 		    state != VB2_BUF_STATE_ERROR &&
1002 		    state != VB2_BUF_STATE_QUEUED))
1003 		state = VB2_BUF_STATE_ERROR;
1004 
1005 #ifdef CONFIG_VIDEO_ADV_DEBUG
1006 	/*
1007 	 * Although this is not a callback, it still does have to balance
1008 	 * with the buf_queue op. So update this counter manually.
1009 	 */
1010 	vb->cnt_buf_done++;
1011 #endif
1012 	dprintk(q, 4, "done processing on buffer %d, state: %s\n",
1013 		vb->index, vb2_state_name(state));
1014 
1015 	if (state != VB2_BUF_STATE_QUEUED)
1016 		__vb2_buf_mem_finish(vb);
1017 
1018 	spin_lock_irqsave(&q->done_lock, flags);
1019 	if (state == VB2_BUF_STATE_QUEUED) {
1020 		vb->state = VB2_BUF_STATE_QUEUED;
1021 	} else {
1022 		/* Add the buffer to the done buffers list */
1023 		list_add_tail(&vb->done_entry, &q->done_list);
1024 		vb->state = state;
1025 	}
1026 	atomic_dec(&q->owned_by_drv_count);
1027 
1028 	if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
1029 		media_request_object_unbind(&vb->req_obj);
1030 		media_request_object_put(&vb->req_obj);
1031 	}
1032 
1033 	spin_unlock_irqrestore(&q->done_lock, flags);
1034 
1035 	trace_vb2_buf_done(q, vb);
1036 
1037 	switch (state) {
1038 	case VB2_BUF_STATE_QUEUED:
1039 		return;
1040 	default:
1041 		/* Inform any processes that may be waiting for buffers */
1042 		wake_up(&q->done_wq);
1043 		break;
1044 	}
1045 }
1046 EXPORT_SYMBOL_GPL(vb2_buffer_done);
1047 
1048 void vb2_discard_done(struct vb2_queue *q)
1049 {
1050 	struct vb2_buffer *vb;
1051 	unsigned long flags;
1052 
1053 	spin_lock_irqsave(&q->done_lock, flags);
1054 	list_for_each_entry(vb, &q->done_list, done_entry)
1055 		vb->state = VB2_BUF_STATE_ERROR;
1056 	spin_unlock_irqrestore(&q->done_lock, flags);
1057 }
1058 EXPORT_SYMBOL_GPL(vb2_discard_done);
1059 
1060 /*
1061  * __prepare_mmap() - prepare an MMAP buffer
1062  */
1063 static int __prepare_mmap(struct vb2_buffer *vb)
1064 {
1065 	int ret = 0;
1066 
1067 	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1068 			 vb, vb->planes);
1069 	return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
1070 }
1071 
1072 /*
1073  * __prepare_userptr() - prepare a USERPTR buffer
1074  */
1075 static int __prepare_userptr(struct vb2_buffer *vb)
1076 {
1077 	struct vb2_plane planes[VB2_MAX_PLANES];
1078 	struct vb2_queue *q = vb->vb2_queue;
1079 	void *mem_priv;
1080 	unsigned int plane;
1081 	int ret = 0;
1082 	bool reacquired = vb->planes[0].mem_priv == NULL;
1083 
1084 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1085 	/* Copy relevant information provided by the userspace */
1086 	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1087 			 vb, planes);
1088 	if (ret)
1089 		return ret;
1090 
1091 	for (plane = 0; plane < vb->num_planes; ++plane) {
1092 		/* Skip the plane if already verified */
1093 		if (vb->planes[plane].m.userptr &&
1094 			vb->planes[plane].m.userptr == planes[plane].m.userptr
1095 			&& vb->planes[plane].length == planes[plane].length)
1096 			continue;
1097 
1098 		dprintk(q, 3, "userspace address for plane %d changed, reacquiring memory\n",
1099 			plane);
1100 
1101 		/* Check if the provided plane buffer is large enough */
1102 		if (planes[plane].length < vb->planes[plane].min_length) {
1103 			dprintk(q, 1, "provided buffer size %u is less than setup size %u for plane %d\n",
1104 						planes[plane].length,
1105 						vb->planes[plane].min_length,
1106 						plane);
1107 			ret = -EINVAL;
1108 			goto err;
1109 		}
1110 
1111 		/* Release previously acquired memory if present */
1112 		if (vb->planes[plane].mem_priv) {
1113 			if (!reacquired) {
1114 				reacquired = true;
1115 				vb->copied_timestamp = 0;
1116 				call_void_vb_qop(vb, buf_cleanup, vb);
1117 			}
1118 			call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1119 		}
1120 
1121 		vb->planes[plane].mem_priv = NULL;
1122 		vb->planes[plane].bytesused = 0;
1123 		vb->planes[plane].length = 0;
1124 		vb->planes[plane].m.userptr = 0;
1125 		vb->planes[plane].data_offset = 0;
1126 
1127 		/* Acquire each plane's memory */
1128 		mem_priv = call_ptr_memop(vb, get_userptr,
1129 				q->alloc_devs[plane] ? : q->dev,
1130 				planes[plane].m.userptr,
1131 				planes[plane].length, q->dma_dir);
1132 		if (IS_ERR(mem_priv)) {
1133 			dprintk(q, 1, "failed acquiring userspace memory for plane %d\n",
1134 				plane);
1135 			ret = PTR_ERR(mem_priv);
1136 			goto err;
1137 		}
1138 		vb->planes[plane].mem_priv = mem_priv;
1139 	}
1140 
1141 	/*
1142 	 * Now that everything is in order, copy relevant information
1143 	 * provided by userspace.
1144 	 */
1145 	for (plane = 0; plane < vb->num_planes; ++plane) {
1146 		vb->planes[plane].bytesused = planes[plane].bytesused;
1147 		vb->planes[plane].length = planes[plane].length;
1148 		vb->planes[plane].m.userptr = planes[plane].m.userptr;
1149 		vb->planes[plane].data_offset = planes[plane].data_offset;
1150 	}
1151 
1152 	if (reacquired) {
1153 		/*
1154 		 * One or more planes changed, so we must call buf_init to do
1155 		 * the driver-specific initialization on the newly acquired
1156 		 * buffer, if provided.
1157 		 */
1158 		ret = call_vb_qop(vb, buf_init, vb);
1159 		if (ret) {
1160 			dprintk(q, 1, "buffer initialization failed\n");
1161 			goto err;
1162 		}
1163 	}
1164 
1165 	ret = call_vb_qop(vb, buf_prepare, vb);
1166 	if (ret) {
1167 		dprintk(q, 1, "buffer preparation failed\n");
1168 		call_void_vb_qop(vb, buf_cleanup, vb);
1169 		goto err;
1170 	}
1171 
1172 	return 0;
1173 err:
1174 	/* In case of errors, release planes that were already acquired */
1175 	for (plane = 0; plane < vb->num_planes; ++plane) {
1176 		if (vb->planes[plane].mem_priv)
1177 			call_void_memop(vb, put_userptr,
1178 				vb->planes[plane].mem_priv);
1179 		vb->planes[plane].mem_priv = NULL;
1180 		vb->planes[plane].m.userptr = 0;
1181 		vb->planes[plane].length = 0;
1182 	}
1183 
1184 	return ret;
1185 }
1186 
1187 /*
1188  * __prepare_dmabuf() - prepare a DMABUF buffer
1189  */
1190 static int __prepare_dmabuf(struct vb2_buffer *vb)
1191 {
1192 	struct vb2_plane planes[VB2_MAX_PLANES];
1193 	struct vb2_queue *q = vb->vb2_queue;
1194 	void *mem_priv;
1195 	unsigned int plane;
1196 	int ret = 0;
1197 	bool reacquired = vb->planes[0].mem_priv == NULL;
1198 
1199 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1200 	/* Copy relevant information provided by the userspace */
1201 	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1202 			 vb, planes);
1203 	if (ret)
1204 		return ret;
1205 
1206 	for (plane = 0; plane < vb->num_planes; ++plane) {
1207 		struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1208 
1209 		if (IS_ERR_OR_NULL(dbuf)) {
1210 			dprintk(q, 1, "invalid dmabuf fd for plane %d\n",
1211 				plane);
1212 			ret = -EINVAL;
1213 			goto err;
1214 		}
1215 
1216 		/* use DMABUF size if length is not provided */
1217 		if (planes[plane].length == 0)
1218 			planes[plane].length = dbuf->size;
1219 
1220 		if (planes[plane].length < vb->planes[plane].min_length) {
1221 			dprintk(q, 1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1222 				planes[plane].length, plane,
1223 				vb->planes[plane].min_length);
1224 			dma_buf_put(dbuf);
1225 			ret = -EINVAL;
1226 			goto err;
1227 		}
1228 
1229 		/* Skip the plane if already verified */
1230 		if (dbuf == vb->planes[plane].dbuf &&
1231 			vb->planes[plane].length == planes[plane].length) {
1232 			dma_buf_put(dbuf);
1233 			continue;
1234 		}
1235 
1236 		dprintk(q, 3, "buffer for plane %d changed\n", plane);
1237 
1238 		if (!reacquired) {
1239 			reacquired = true;
1240 			vb->copied_timestamp = 0;
1241 			call_void_vb_qop(vb, buf_cleanup, vb);
1242 		}
1243 
1244 		/* Release previously acquired memory if present */
1245 		__vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1246 		vb->planes[plane].bytesused = 0;
1247 		vb->planes[plane].length = 0;
1248 		vb->planes[plane].m.fd = 0;
1249 		vb->planes[plane].data_offset = 0;
1250 
1251 		/* Acquire each plane's memory */
1252 		mem_priv = call_ptr_memop(vb, attach_dmabuf,
1253 				q->alloc_devs[plane] ? : q->dev,
1254 				dbuf, planes[plane].length, q->dma_dir);
1255 		if (IS_ERR(mem_priv)) {
1256 			dprintk(q, 1, "failed to attach dmabuf\n");
1257 			ret = PTR_ERR(mem_priv);
1258 			dma_buf_put(dbuf);
1259 			goto err;
1260 		}
1261 
1262 		vb->planes[plane].dbuf = dbuf;
1263 		vb->planes[plane].mem_priv = mem_priv;
1264 	}
1265 
1266 	/*
1267 	 * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1268 	 * here instead just before the DMA, while queueing the buffer(s) so
1269 	 * userspace knows sooner rather than later if the dma-buf map fails.
1270 	 */
1271 	for (plane = 0; plane < vb->num_planes; ++plane) {
1272 		if (vb->planes[plane].dbuf_mapped)
1273 			continue;
1274 
1275 		ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1276 		if (ret) {
1277 			dprintk(q, 1, "failed to map dmabuf for plane %d\n",
1278 				plane);
1279 			goto err;
1280 		}
1281 		vb->planes[plane].dbuf_mapped = 1;
1282 	}
1283 
1284 	/*
1285 	 * Now that everything is in order, copy relevant information
1286 	 * provided by userspace.
1287 	 */
1288 	for (plane = 0; plane < vb->num_planes; ++plane) {
1289 		vb->planes[plane].bytesused = planes[plane].bytesused;
1290 		vb->planes[plane].length = planes[plane].length;
1291 		vb->planes[plane].m.fd = planes[plane].m.fd;
1292 		vb->planes[plane].data_offset = planes[plane].data_offset;
1293 	}
1294 
1295 	if (reacquired) {
1296 		/*
1297 		 * Call driver-specific initialization on the newly acquired buffer,
1298 		 * if provided.
1299 		 */
1300 		ret = call_vb_qop(vb, buf_init, vb);
1301 		if (ret) {
1302 			dprintk(q, 1, "buffer initialization failed\n");
1303 			goto err;
1304 		}
1305 	}
1306 
1307 	ret = call_vb_qop(vb, buf_prepare, vb);
1308 	if (ret) {
1309 		dprintk(q, 1, "buffer preparation failed\n");
1310 		call_void_vb_qop(vb, buf_cleanup, vb);
1311 		goto err;
1312 	}
1313 
1314 	return 0;
1315 err:
1316 	/* In case of errors, release planes that were already acquired */
1317 	__vb2_buf_dmabuf_put(vb);
1318 
1319 	return ret;
1320 }
1321 
1322 /*
1323  * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1324  */
1325 static void __enqueue_in_driver(struct vb2_buffer *vb)
1326 {
1327 	struct vb2_queue *q = vb->vb2_queue;
1328 
1329 	vb->state = VB2_BUF_STATE_ACTIVE;
1330 	atomic_inc(&q->owned_by_drv_count);
1331 
1332 	trace_vb2_buf_queue(q, vb);
1333 
1334 	call_void_vb_qop(vb, buf_queue, vb);
1335 }
1336 
1337 static int __buf_prepare(struct vb2_buffer *vb)
1338 {
1339 	struct vb2_queue *q = vb->vb2_queue;
1340 	enum vb2_buffer_state orig_state = vb->state;
1341 	int ret;
1342 
1343 	if (q->error) {
1344 		dprintk(q, 1, "fatal error occurred on queue\n");
1345 		return -EIO;
1346 	}
1347 
1348 	if (vb->prepared)
1349 		return 0;
1350 	WARN_ON(vb->synced);
1351 
1352 	if (q->is_output) {
1353 		ret = call_vb_qop(vb, buf_out_validate, vb);
1354 		if (ret) {
1355 			dprintk(q, 1, "buffer validation failed\n");
1356 			return ret;
1357 		}
1358 	}
1359 
1360 	vb->state = VB2_BUF_STATE_PREPARING;
1361 
1362 	switch (q->memory) {
1363 	case VB2_MEMORY_MMAP:
1364 		ret = __prepare_mmap(vb);
1365 		break;
1366 	case VB2_MEMORY_USERPTR:
1367 		ret = __prepare_userptr(vb);
1368 		break;
1369 	case VB2_MEMORY_DMABUF:
1370 		ret = __prepare_dmabuf(vb);
1371 		break;
1372 	default:
1373 		WARN(1, "Invalid queue type\n");
1374 		ret = -EINVAL;
1375 		break;
1376 	}
1377 
1378 	if (ret) {
1379 		dprintk(q, 1, "buffer preparation failed: %d\n", ret);
1380 		vb->state = orig_state;
1381 		return ret;
1382 	}
1383 
1384 	__vb2_buf_mem_prepare(vb);
1385 	vb->prepared = 1;
1386 	vb->state = orig_state;
1387 
1388 	return 0;
1389 }
1390 
1391 static int vb2_req_prepare(struct media_request_object *obj)
1392 {
1393 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1394 	int ret;
1395 
1396 	if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
1397 		return -EINVAL;
1398 
1399 	mutex_lock(vb->vb2_queue->lock);
1400 	ret = __buf_prepare(vb);
1401 	mutex_unlock(vb->vb2_queue->lock);
1402 	return ret;
1403 }
1404 
1405 static void __vb2_dqbuf(struct vb2_buffer *vb);
1406 
1407 static void vb2_req_unprepare(struct media_request_object *obj)
1408 {
1409 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1410 
1411 	mutex_lock(vb->vb2_queue->lock);
1412 	__vb2_dqbuf(vb);
1413 	vb->state = VB2_BUF_STATE_IN_REQUEST;
1414 	mutex_unlock(vb->vb2_queue->lock);
1415 	WARN_ON(!vb->req_obj.req);
1416 }
1417 
1418 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1419 		  struct media_request *req);
1420 
1421 static void vb2_req_queue(struct media_request_object *obj)
1422 {
1423 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1424 
1425 	mutex_lock(vb->vb2_queue->lock);
1426 	vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
1427 	mutex_unlock(vb->vb2_queue->lock);
1428 }
1429 
1430 static void vb2_req_unbind(struct media_request_object *obj)
1431 {
1432 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1433 
1434 	if (vb->state == VB2_BUF_STATE_IN_REQUEST)
1435 		call_void_bufop(vb->vb2_queue, init_buffer, vb);
1436 }
1437 
1438 static void vb2_req_release(struct media_request_object *obj)
1439 {
1440 	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
1441 
1442 	if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
1443 		vb->state = VB2_BUF_STATE_DEQUEUED;
1444 		if (vb->request)
1445 			media_request_put(vb->request);
1446 		vb->request = NULL;
1447 	}
1448 }
1449 
1450 static const struct media_request_object_ops vb2_core_req_ops = {
1451 	.prepare = vb2_req_prepare,
1452 	.unprepare = vb2_req_unprepare,
1453 	.queue = vb2_req_queue,
1454 	.unbind = vb2_req_unbind,
1455 	.release = vb2_req_release,
1456 };
1457 
1458 bool vb2_request_object_is_buffer(struct media_request_object *obj)
1459 {
1460 	return obj->ops == &vb2_core_req_ops;
1461 }
1462 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
1463 
1464 unsigned int vb2_request_buffer_cnt(struct media_request *req)
1465 {
1466 	struct media_request_object *obj;
1467 	unsigned long flags;
1468 	unsigned int buffer_cnt = 0;
1469 
1470 	spin_lock_irqsave(&req->lock, flags);
1471 	list_for_each_entry(obj, &req->objects, list)
1472 		if (vb2_request_object_is_buffer(obj))
1473 			buffer_cnt++;
1474 	spin_unlock_irqrestore(&req->lock, flags);
1475 
1476 	return buffer_cnt;
1477 }
1478 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
1479 
1480 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1481 {
1482 	struct vb2_buffer *vb;
1483 	int ret;
1484 
1485 	vb = q->bufs[index];
1486 	if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1487 		dprintk(q, 1, "invalid buffer state %s\n",
1488 			vb2_state_name(vb->state));
1489 		return -EINVAL;
1490 	}
1491 	if (vb->prepared) {
1492 		dprintk(q, 1, "buffer already prepared\n");
1493 		return -EINVAL;
1494 	}
1495 
1496 	ret = __buf_prepare(vb);
1497 	if (ret)
1498 		return ret;
1499 
1500 	/* Fill buffer information for the userspace */
1501 	call_void_bufop(q, fill_user_buffer, vb, pb);
1502 
1503 	dprintk(q, 2, "prepare of buffer %d succeeded\n", vb->index);
1504 
1505 	return 0;
1506 }
1507 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1508 
1509 /*
1510  * vb2_start_streaming() - Attempt to start streaming.
1511  * @q:		videobuf2 queue
1512  *
1513  * Attempt to start streaming. When this function is called there must be
1514  * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1515  * number of buffers required for the DMA engine to function). If the
1516  * @start_streaming op fails it is supposed to return all the driver-owned
1517  * buffers back to vb2 in state QUEUED. Check if that happened and if
1518  * not warn and reclaim them forcefully.
1519  */
1520 static int vb2_start_streaming(struct vb2_queue *q)
1521 {
1522 	struct vb2_buffer *vb;
1523 	int ret;
1524 
1525 	/*
1526 	 * If any buffers were queued before streamon,
1527 	 * we can now pass them to driver for processing.
1528 	 */
1529 	list_for_each_entry(vb, &q->queued_list, queued_entry)
1530 		__enqueue_in_driver(vb);
1531 
1532 	/* Tell the driver to start streaming */
1533 	q->start_streaming_called = 1;
1534 	ret = call_qop(q, start_streaming, q,
1535 		       atomic_read(&q->owned_by_drv_count));
1536 	if (!ret)
1537 		return 0;
1538 
1539 	q->start_streaming_called = 0;
1540 
1541 	dprintk(q, 1, "driver refused to start streaming\n");
1542 	/*
1543 	 * If you see this warning, then the driver isn't cleaning up properly
1544 	 * after a failed start_streaming(). See the start_streaming()
1545 	 * documentation in videobuf2-core.h for more information how buffers
1546 	 * should be returned to vb2 in start_streaming().
1547 	 */
1548 	if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1549 		unsigned i;
1550 
1551 		/*
1552 		 * Forcefully reclaim buffers if the driver did not
1553 		 * correctly return them to vb2.
1554 		 */
1555 		for (i = 0; i < q->num_buffers; ++i) {
1556 			vb = q->bufs[i];
1557 			if (vb->state == VB2_BUF_STATE_ACTIVE)
1558 				vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1559 		}
1560 		/* Must be zero now */
1561 		WARN_ON(atomic_read(&q->owned_by_drv_count));
1562 	}
1563 	/*
1564 	 * If done_list is not empty, then start_streaming() didn't call
1565 	 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1566 	 * STATE_DONE.
1567 	 */
1568 	WARN_ON(!list_empty(&q->done_list));
1569 	return ret;
1570 }
1571 
1572 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
1573 		  struct media_request *req)
1574 {
1575 	struct vb2_buffer *vb;
1576 	int ret;
1577 
1578 	if (q->error) {
1579 		dprintk(q, 1, "fatal error occurred on queue\n");
1580 		return -EIO;
1581 	}
1582 
1583 	vb = q->bufs[index];
1584 
1585 	if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1586 	    q->requires_requests) {
1587 		dprintk(q, 1, "qbuf requires a request\n");
1588 		return -EBADR;
1589 	}
1590 
1591 	if ((req && q->uses_qbuf) ||
1592 	    (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
1593 	     q->uses_requests)) {
1594 		dprintk(q, 1, "queue in wrong mode (qbuf vs requests)\n");
1595 		return -EBUSY;
1596 	}
1597 
1598 	if (req) {
1599 		int ret;
1600 
1601 		q->uses_requests = 1;
1602 		if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1603 			dprintk(q, 1, "buffer %d not in dequeued state\n",
1604 				vb->index);
1605 			return -EINVAL;
1606 		}
1607 
1608 		if (q->is_output && !vb->prepared) {
1609 			ret = call_vb_qop(vb, buf_out_validate, vb);
1610 			if (ret) {
1611 				dprintk(q, 1, "buffer validation failed\n");
1612 				return ret;
1613 			}
1614 		}
1615 
1616 		media_request_object_init(&vb->req_obj);
1617 
1618 		/* Make sure the request is in a safe state for updating. */
1619 		ret = media_request_lock_for_update(req);
1620 		if (ret)
1621 			return ret;
1622 		ret = media_request_object_bind(req, &vb2_core_req_ops,
1623 						q, true, &vb->req_obj);
1624 		media_request_unlock_for_update(req);
1625 		if (ret)
1626 			return ret;
1627 
1628 		vb->state = VB2_BUF_STATE_IN_REQUEST;
1629 
1630 		/*
1631 		 * Increment the refcount and store the request.
1632 		 * The request refcount is decremented again when the
1633 		 * buffer is dequeued. This is to prevent vb2_buffer_done()
1634 		 * from freeing the request from interrupt context, which can
1635 		 * happen if the application closed the request fd after
1636 		 * queueing the request.
1637 		 */
1638 		media_request_get(req);
1639 		vb->request = req;
1640 
1641 		/* Fill buffer information for the userspace */
1642 		if (pb) {
1643 			call_void_bufop(q, copy_timestamp, vb, pb);
1644 			call_void_bufop(q, fill_user_buffer, vb, pb);
1645 		}
1646 
1647 		dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1648 		return 0;
1649 	}
1650 
1651 	if (vb->state != VB2_BUF_STATE_IN_REQUEST)
1652 		q->uses_qbuf = 1;
1653 
1654 	switch (vb->state) {
1655 	case VB2_BUF_STATE_DEQUEUED:
1656 	case VB2_BUF_STATE_IN_REQUEST:
1657 		if (!vb->prepared) {
1658 			ret = __buf_prepare(vb);
1659 			if (ret)
1660 				return ret;
1661 		}
1662 		break;
1663 	case VB2_BUF_STATE_PREPARING:
1664 		dprintk(q, 1, "buffer still being prepared\n");
1665 		return -EINVAL;
1666 	default:
1667 		dprintk(q, 1, "invalid buffer state %s\n",
1668 			vb2_state_name(vb->state));
1669 		return -EINVAL;
1670 	}
1671 
1672 	/*
1673 	 * Add to the queued buffers list, a buffer will stay on it until
1674 	 * dequeued in dqbuf.
1675 	 */
1676 	list_add_tail(&vb->queued_entry, &q->queued_list);
1677 	q->queued_count++;
1678 	q->waiting_for_buffers = false;
1679 	vb->state = VB2_BUF_STATE_QUEUED;
1680 
1681 	if (pb)
1682 		call_void_bufop(q, copy_timestamp, vb, pb);
1683 
1684 	trace_vb2_qbuf(q, vb);
1685 
1686 	/*
1687 	 * If already streaming, give the buffer to driver for processing.
1688 	 * If not, the buffer will be given to driver on next streamon.
1689 	 */
1690 	if (q->start_streaming_called)
1691 		__enqueue_in_driver(vb);
1692 
1693 	/* Fill buffer information for the userspace */
1694 	if (pb)
1695 		call_void_bufop(q, fill_user_buffer, vb, pb);
1696 
1697 	/*
1698 	 * If streamon has been called, and we haven't yet called
1699 	 * start_streaming() since not enough buffers were queued, and
1700 	 * we now have reached the minimum number of queued buffers,
1701 	 * then we can finally call start_streaming().
1702 	 */
1703 	if (q->streaming && !q->start_streaming_called &&
1704 	    q->queued_count >= q->min_buffers_needed) {
1705 		ret = vb2_start_streaming(q);
1706 		if (ret)
1707 			return ret;
1708 	}
1709 
1710 	dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
1711 	return 0;
1712 }
1713 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1714 
1715 /*
1716  * __vb2_wait_for_done_vb() - wait for a buffer to become available
1717  * for dequeuing
1718  *
1719  * Will sleep if required for nonblocking == false.
1720  */
1721 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1722 {
1723 	/*
1724 	 * All operations on vb_done_list are performed under done_lock
1725 	 * spinlock protection. However, buffers may be removed from
1726 	 * it and returned to userspace only while holding both driver's
1727 	 * lock and the done_lock spinlock. Thus we can be sure that as
1728 	 * long as we hold the driver's lock, the list will remain not
1729 	 * empty if list_empty() check succeeds.
1730 	 */
1731 
1732 	for (;;) {
1733 		int ret;
1734 
1735 		if (q->waiting_in_dqbuf) {
1736 			dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
1737 			return -EBUSY;
1738 		}
1739 
1740 		if (!q->streaming) {
1741 			dprintk(q, 1, "streaming off, will not wait for buffers\n");
1742 			return -EINVAL;
1743 		}
1744 
1745 		if (q->error) {
1746 			dprintk(q, 1, "Queue in error state, will not wait for buffers\n");
1747 			return -EIO;
1748 		}
1749 
1750 		if (q->last_buffer_dequeued) {
1751 			dprintk(q, 3, "last buffer dequeued already, will not wait for buffers\n");
1752 			return -EPIPE;
1753 		}
1754 
1755 		if (!list_empty(&q->done_list)) {
1756 			/*
1757 			 * Found a buffer that we were waiting for.
1758 			 */
1759 			break;
1760 		}
1761 
1762 		if (nonblocking) {
1763 			dprintk(q, 3, "nonblocking and no buffers to dequeue, will not wait\n");
1764 			return -EAGAIN;
1765 		}
1766 
1767 		q->waiting_in_dqbuf = 1;
1768 		/*
1769 		 * We are streaming and blocking, wait for another buffer to
1770 		 * become ready or for streamoff. Driver's lock is released to
1771 		 * allow streamoff or qbuf to be called while waiting.
1772 		 */
1773 		call_void_qop(q, wait_prepare, q);
1774 
1775 		/*
1776 		 * All locks have been released, it is safe to sleep now.
1777 		 */
1778 		dprintk(q, 3, "will sleep waiting for buffers\n");
1779 		ret = wait_event_interruptible(q->done_wq,
1780 				!list_empty(&q->done_list) || !q->streaming ||
1781 				q->error);
1782 
1783 		/*
1784 		 * We need to reevaluate both conditions again after reacquiring
1785 		 * the locks or return an error if one occurred.
1786 		 */
1787 		call_void_qop(q, wait_finish, q);
1788 		q->waiting_in_dqbuf = 0;
1789 		if (ret) {
1790 			dprintk(q, 1, "sleep was interrupted\n");
1791 			return ret;
1792 		}
1793 	}
1794 	return 0;
1795 }
1796 
1797 /*
1798  * __vb2_get_done_vb() - get a buffer ready for dequeuing
1799  *
1800  * Will sleep if required for nonblocking == false.
1801  */
1802 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1803 			     void *pb, int nonblocking)
1804 {
1805 	unsigned long flags;
1806 	int ret = 0;
1807 
1808 	/*
1809 	 * Wait for at least one buffer to become available on the done_list.
1810 	 */
1811 	ret = __vb2_wait_for_done_vb(q, nonblocking);
1812 	if (ret)
1813 		return ret;
1814 
1815 	/*
1816 	 * Driver's lock has been held since we last verified that done_list
1817 	 * is not empty, so no need for another list_empty(done_list) check.
1818 	 */
1819 	spin_lock_irqsave(&q->done_lock, flags);
1820 	*vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1821 	/*
1822 	 * Only remove the buffer from done_list if all planes can be
1823 	 * handled. Some cases such as V4L2 file I/O and DVB have pb
1824 	 * == NULL; skip the check then as there's nothing to verify.
1825 	 */
1826 	if (pb)
1827 		ret = call_bufop(q, verify_planes_array, *vb, pb);
1828 	if (!ret)
1829 		list_del(&(*vb)->done_entry);
1830 	spin_unlock_irqrestore(&q->done_lock, flags);
1831 
1832 	return ret;
1833 }
1834 
1835 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1836 {
1837 	if (!q->streaming) {
1838 		dprintk(q, 1, "streaming off, will not wait for buffers\n");
1839 		return -EINVAL;
1840 	}
1841 
1842 	if (q->start_streaming_called)
1843 		wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1844 	return 0;
1845 }
1846 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1847 
1848 /*
1849  * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1850  */
1851 static void __vb2_dqbuf(struct vb2_buffer *vb)
1852 {
1853 	struct vb2_queue *q = vb->vb2_queue;
1854 
1855 	/* nothing to do if the buffer is already dequeued */
1856 	if (vb->state == VB2_BUF_STATE_DEQUEUED)
1857 		return;
1858 
1859 	vb->state = VB2_BUF_STATE_DEQUEUED;
1860 
1861 	call_void_bufop(q, init_buffer, vb);
1862 }
1863 
1864 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1865 		   bool nonblocking)
1866 {
1867 	struct vb2_buffer *vb = NULL;
1868 	int ret;
1869 
1870 	ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1871 	if (ret < 0)
1872 		return ret;
1873 
1874 	switch (vb->state) {
1875 	case VB2_BUF_STATE_DONE:
1876 		dprintk(q, 3, "returning done buffer\n");
1877 		break;
1878 	case VB2_BUF_STATE_ERROR:
1879 		dprintk(q, 3, "returning done buffer with errors\n");
1880 		break;
1881 	default:
1882 		dprintk(q, 1, "invalid buffer state %s\n",
1883 			vb2_state_name(vb->state));
1884 		return -EINVAL;
1885 	}
1886 
1887 	call_void_vb_qop(vb, buf_finish, vb);
1888 	vb->prepared = 0;
1889 
1890 	if (pindex)
1891 		*pindex = vb->index;
1892 
1893 	/* Fill buffer information for the userspace */
1894 	if (pb)
1895 		call_void_bufop(q, fill_user_buffer, vb, pb);
1896 
1897 	/* Remove from videobuf queue */
1898 	list_del(&vb->queued_entry);
1899 	q->queued_count--;
1900 
1901 	trace_vb2_dqbuf(q, vb);
1902 
1903 	/* go back to dequeued state */
1904 	__vb2_dqbuf(vb);
1905 
1906 	if (WARN_ON(vb->req_obj.req)) {
1907 		media_request_object_unbind(&vb->req_obj);
1908 		media_request_object_put(&vb->req_obj);
1909 	}
1910 	if (vb->request)
1911 		media_request_put(vb->request);
1912 	vb->request = NULL;
1913 
1914 	dprintk(q, 2, "dqbuf of buffer %d, state: %s\n",
1915 		vb->index, vb2_state_name(vb->state));
1916 
1917 	return 0;
1918 
1919 }
1920 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1921 
1922 /*
1923  * __vb2_queue_cancel() - cancel and stop (pause) streaming
1924  *
1925  * Removes all queued buffers from driver's queue and all buffers queued by
1926  * userspace from videobuf's queue. Returns to state after reqbufs.
1927  */
1928 static void __vb2_queue_cancel(struct vb2_queue *q)
1929 {
1930 	unsigned int i;
1931 
1932 	/*
1933 	 * Tell driver to stop all transactions and release all queued
1934 	 * buffers.
1935 	 */
1936 	if (q->start_streaming_called)
1937 		call_void_qop(q, stop_streaming, q);
1938 
1939 	/*
1940 	 * If you see this warning, then the driver isn't cleaning up properly
1941 	 * in stop_streaming(). See the stop_streaming() documentation in
1942 	 * videobuf2-core.h for more information how buffers should be returned
1943 	 * to vb2 in stop_streaming().
1944 	 */
1945 	if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1946 		for (i = 0; i < q->num_buffers; ++i)
1947 			if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
1948 				pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
1949 					q->bufs[i]);
1950 				vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1951 			}
1952 		/* Must be zero now */
1953 		WARN_ON(atomic_read(&q->owned_by_drv_count));
1954 	}
1955 
1956 	q->streaming = 0;
1957 	q->start_streaming_called = 0;
1958 	q->queued_count = 0;
1959 	q->error = 0;
1960 	q->uses_requests = 0;
1961 	q->uses_qbuf = 0;
1962 
1963 	/*
1964 	 * Remove all buffers from videobuf's list...
1965 	 */
1966 	INIT_LIST_HEAD(&q->queued_list);
1967 	/*
1968 	 * ...and done list; userspace will not receive any buffers it
1969 	 * has not already dequeued before initiating cancel.
1970 	 */
1971 	INIT_LIST_HEAD(&q->done_list);
1972 	atomic_set(&q->owned_by_drv_count, 0);
1973 	wake_up_all(&q->done_wq);
1974 
1975 	/*
1976 	 * Reinitialize all buffers for next use.
1977 	 * Make sure to call buf_finish for any queued buffers. Normally
1978 	 * that's done in dqbuf, but that's not going to happen when we
1979 	 * cancel the whole queue. Note: this code belongs here, not in
1980 	 * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1981 	 * call to __fill_user_buffer() after buf_finish(). That order can't
1982 	 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1983 	 */
1984 	for (i = 0; i < q->num_buffers; ++i) {
1985 		struct vb2_buffer *vb = q->bufs[i];
1986 		struct media_request *req = vb->req_obj.req;
1987 
1988 		/*
1989 		 * If a request is associated with this buffer, then
1990 		 * call buf_request_cancel() to give the driver to complete()
1991 		 * related request objects. Otherwise those objects would
1992 		 * never complete.
1993 		 */
1994 		if (req) {
1995 			enum media_request_state state;
1996 			unsigned long flags;
1997 
1998 			spin_lock_irqsave(&req->lock, flags);
1999 			state = req->state;
2000 			spin_unlock_irqrestore(&req->lock, flags);
2001 
2002 			if (state == MEDIA_REQUEST_STATE_QUEUED)
2003 				call_void_vb_qop(vb, buf_request_complete, vb);
2004 		}
2005 
2006 		__vb2_buf_mem_finish(vb);
2007 
2008 		if (vb->prepared) {
2009 			call_void_vb_qop(vb, buf_finish, vb);
2010 			vb->prepared = 0;
2011 		}
2012 		__vb2_dqbuf(vb);
2013 
2014 		if (vb->req_obj.req) {
2015 			media_request_object_unbind(&vb->req_obj);
2016 			media_request_object_put(&vb->req_obj);
2017 		}
2018 		if (vb->request)
2019 			media_request_put(vb->request);
2020 		vb->request = NULL;
2021 		vb->copied_timestamp = 0;
2022 	}
2023 }
2024 
2025 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
2026 {
2027 	int ret;
2028 
2029 	if (type != q->type) {
2030 		dprintk(q, 1, "invalid stream type\n");
2031 		return -EINVAL;
2032 	}
2033 
2034 	if (q->streaming) {
2035 		dprintk(q, 3, "already streaming\n");
2036 		return 0;
2037 	}
2038 
2039 	if (!q->num_buffers) {
2040 		dprintk(q, 1, "no buffers have been allocated\n");
2041 		return -EINVAL;
2042 	}
2043 
2044 	if (q->num_buffers < q->min_buffers_needed) {
2045 		dprintk(q, 1, "need at least %u allocated buffers\n",
2046 				q->min_buffers_needed);
2047 		return -EINVAL;
2048 	}
2049 
2050 	/*
2051 	 * Tell driver to start streaming provided sufficient buffers
2052 	 * are available.
2053 	 */
2054 	if (q->queued_count >= q->min_buffers_needed) {
2055 		ret = v4l_vb2q_enable_media_source(q);
2056 		if (ret)
2057 			return ret;
2058 		ret = vb2_start_streaming(q);
2059 		if (ret)
2060 			return ret;
2061 	}
2062 
2063 	q->streaming = 1;
2064 
2065 	dprintk(q, 3, "successful\n");
2066 	return 0;
2067 }
2068 EXPORT_SYMBOL_GPL(vb2_core_streamon);
2069 
2070 void vb2_queue_error(struct vb2_queue *q)
2071 {
2072 	q->error = 1;
2073 
2074 	wake_up_all(&q->done_wq);
2075 }
2076 EXPORT_SYMBOL_GPL(vb2_queue_error);
2077 
2078 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
2079 {
2080 	if (type != q->type) {
2081 		dprintk(q, 1, "invalid stream type\n");
2082 		return -EINVAL;
2083 	}
2084 
2085 	/*
2086 	 * Cancel will pause streaming and remove all buffers from the driver
2087 	 * and videobuf, effectively returning control over them to userspace.
2088 	 *
2089 	 * Note that we do this even if q->streaming == 0: if you prepare or
2090 	 * queue buffers, and then call streamoff without ever having called
2091 	 * streamon, you would still expect those buffers to be returned to
2092 	 * their normal dequeued state.
2093 	 */
2094 	__vb2_queue_cancel(q);
2095 	q->waiting_for_buffers = !q->is_output;
2096 	q->last_buffer_dequeued = false;
2097 
2098 	dprintk(q, 3, "successful\n");
2099 	return 0;
2100 }
2101 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
2102 
2103 /*
2104  * __find_plane_by_offset() - find plane associated with the given offset off
2105  */
2106 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
2107 			unsigned int *_buffer, unsigned int *_plane)
2108 {
2109 	struct vb2_buffer *vb;
2110 	unsigned int buffer, plane;
2111 
2112 	/*
2113 	 * Go over all buffers and their planes, comparing the given offset
2114 	 * with an offset assigned to each plane. If a match is found,
2115 	 * return its buffer and plane numbers.
2116 	 */
2117 	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
2118 		vb = q->bufs[buffer];
2119 
2120 		for (plane = 0; plane < vb->num_planes; ++plane) {
2121 			if (vb->planes[plane].m.offset == off) {
2122 				*_buffer = buffer;
2123 				*_plane = plane;
2124 				return 0;
2125 			}
2126 		}
2127 	}
2128 
2129 	return -EINVAL;
2130 }
2131 
2132 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
2133 		unsigned int index, unsigned int plane, unsigned int flags)
2134 {
2135 	struct vb2_buffer *vb = NULL;
2136 	struct vb2_plane *vb_plane;
2137 	int ret;
2138 	struct dma_buf *dbuf;
2139 
2140 	if (q->memory != VB2_MEMORY_MMAP) {
2141 		dprintk(q, 1, "queue is not currently set up for mmap\n");
2142 		return -EINVAL;
2143 	}
2144 
2145 	if (!q->mem_ops->get_dmabuf) {
2146 		dprintk(q, 1, "queue does not support DMA buffer exporting\n");
2147 		return -EINVAL;
2148 	}
2149 
2150 	if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
2151 		dprintk(q, 1, "queue does support only O_CLOEXEC and access mode flags\n");
2152 		return -EINVAL;
2153 	}
2154 
2155 	if (type != q->type) {
2156 		dprintk(q, 1, "invalid buffer type\n");
2157 		return -EINVAL;
2158 	}
2159 
2160 	if (index >= q->num_buffers) {
2161 		dprintk(q, 1, "buffer index out of range\n");
2162 		return -EINVAL;
2163 	}
2164 
2165 	vb = q->bufs[index];
2166 
2167 	if (plane >= vb->num_planes) {
2168 		dprintk(q, 1, "buffer plane out of range\n");
2169 		return -EINVAL;
2170 	}
2171 
2172 	if (vb2_fileio_is_active(q)) {
2173 		dprintk(q, 1, "expbuf: file io in progress\n");
2174 		return -EBUSY;
2175 	}
2176 
2177 	vb_plane = &vb->planes[plane];
2178 
2179 	dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
2180 				flags & O_ACCMODE);
2181 	if (IS_ERR_OR_NULL(dbuf)) {
2182 		dprintk(q, 1, "failed to export buffer %d, plane %d\n",
2183 			index, plane);
2184 		return -EINVAL;
2185 	}
2186 
2187 	ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
2188 	if (ret < 0) {
2189 		dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",
2190 			index, plane, ret);
2191 		dma_buf_put(dbuf);
2192 		return ret;
2193 	}
2194 
2195 	dprintk(q, 3, "buffer %d, plane %d exported as %d descriptor\n",
2196 		index, plane, ret);
2197 	*fd = ret;
2198 
2199 	return 0;
2200 }
2201 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
2202 
2203 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
2204 {
2205 	unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
2206 	struct vb2_buffer *vb;
2207 	unsigned int buffer = 0, plane = 0;
2208 	int ret;
2209 	unsigned long length;
2210 
2211 	if (q->memory != VB2_MEMORY_MMAP) {
2212 		dprintk(q, 1, "queue is not currently set up for mmap\n");
2213 		return -EINVAL;
2214 	}
2215 
2216 	/*
2217 	 * Check memory area access mode.
2218 	 */
2219 	if (!(vma->vm_flags & VM_SHARED)) {
2220 		dprintk(q, 1, "invalid vma flags, VM_SHARED needed\n");
2221 		return -EINVAL;
2222 	}
2223 	if (q->is_output) {
2224 		if (!(vma->vm_flags & VM_WRITE)) {
2225 			dprintk(q, 1, "invalid vma flags, VM_WRITE needed\n");
2226 			return -EINVAL;
2227 		}
2228 	} else {
2229 		if (!(vma->vm_flags & VM_READ)) {
2230 			dprintk(q, 1, "invalid vma flags, VM_READ needed\n");
2231 			return -EINVAL;
2232 		}
2233 	}
2234 
2235 	mutex_lock(&q->mmap_lock);
2236 
2237 	if (vb2_fileio_is_active(q)) {
2238 		dprintk(q, 1, "mmap: file io in progress\n");
2239 		ret = -EBUSY;
2240 		goto unlock;
2241 	}
2242 
2243 	/*
2244 	 * Find the plane corresponding to the offset passed by userspace.
2245 	 */
2246 	ret = __find_plane_by_offset(q, off, &buffer, &plane);
2247 	if (ret)
2248 		goto unlock;
2249 
2250 	vb = q->bufs[buffer];
2251 
2252 	/*
2253 	 * MMAP requires page_aligned buffers.
2254 	 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2255 	 * so, we need to do the same here.
2256 	 */
2257 	length = PAGE_ALIGN(vb->planes[plane].length);
2258 	if (length < (vma->vm_end - vma->vm_start)) {
2259 		dprintk(q, 1,
2260 			"MMAP invalid, as it would overflow buffer length\n");
2261 		ret = -EINVAL;
2262 		goto unlock;
2263 	}
2264 
2265 	/*
2266 	 * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
2267 	 * not as a in-buffer offset. We always want to mmap a whole buffer
2268 	 * from its beginning.
2269 	 */
2270 	vma->vm_pgoff = 0;
2271 
2272 	ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
2273 
2274 unlock:
2275 	mutex_unlock(&q->mmap_lock);
2276 	if (ret)
2277 		return ret;
2278 
2279 	dprintk(q, 3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
2280 	return 0;
2281 }
2282 EXPORT_SYMBOL_GPL(vb2_mmap);
2283 
2284 #ifndef CONFIG_MMU
2285 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
2286 				    unsigned long addr,
2287 				    unsigned long len,
2288 				    unsigned long pgoff,
2289 				    unsigned long flags)
2290 {
2291 	unsigned long off = pgoff << PAGE_SHIFT;
2292 	struct vb2_buffer *vb;
2293 	unsigned int buffer, plane;
2294 	void *vaddr;
2295 	int ret;
2296 
2297 	if (q->memory != VB2_MEMORY_MMAP) {
2298 		dprintk(q, 1, "queue is not currently set up for mmap\n");
2299 		return -EINVAL;
2300 	}
2301 
2302 	/*
2303 	 * Find the plane corresponding to the offset passed by userspace.
2304 	 */
2305 	ret = __find_plane_by_offset(q, off, &buffer, &plane);
2306 	if (ret)
2307 		return ret;
2308 
2309 	vb = q->bufs[buffer];
2310 
2311 	vaddr = vb2_plane_vaddr(vb, plane);
2312 	return vaddr ? (unsigned long)vaddr : -EINVAL;
2313 }
2314 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2315 #endif
2316 
2317 int vb2_core_queue_init(struct vb2_queue *q)
2318 {
2319 	/*
2320 	 * Sanity check
2321 	 */
2322 	if (WARN_ON(!q)			  ||
2323 	    WARN_ON(!q->ops)		  ||
2324 	    WARN_ON(!q->mem_ops)	  ||
2325 	    WARN_ON(!q->type)		  ||
2326 	    WARN_ON(!q->io_modes)	  ||
2327 	    WARN_ON(!q->ops->queue_setup) ||
2328 	    WARN_ON(!q->ops->buf_queue))
2329 		return -EINVAL;
2330 
2331 	if (WARN_ON(q->requires_requests && !q->supports_requests))
2332 		return -EINVAL;
2333 
2334 	INIT_LIST_HEAD(&q->queued_list);
2335 	INIT_LIST_HEAD(&q->done_list);
2336 	spin_lock_init(&q->done_lock);
2337 	mutex_init(&q->mmap_lock);
2338 	init_waitqueue_head(&q->done_wq);
2339 
2340 	q->memory = VB2_MEMORY_UNKNOWN;
2341 
2342 	if (q->buf_struct_size == 0)
2343 		q->buf_struct_size = sizeof(struct vb2_buffer);
2344 
2345 	if (q->bidirectional)
2346 		q->dma_dir = DMA_BIDIRECTIONAL;
2347 	else
2348 		q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2349 
2350 	if (q->name[0] == '\0')
2351 		snprintf(q->name, sizeof(q->name), "%s-%p",
2352 			 q->is_output ? "out" : "cap", q);
2353 
2354 	return 0;
2355 }
2356 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2357 
2358 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2359 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2360 void vb2_core_queue_release(struct vb2_queue *q)
2361 {
2362 	__vb2_cleanup_fileio(q);
2363 	__vb2_queue_cancel(q);
2364 	mutex_lock(&q->mmap_lock);
2365 	__vb2_queue_free(q, q->num_buffers);
2366 	mutex_unlock(&q->mmap_lock);
2367 }
2368 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2369 
2370 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2371 		poll_table *wait)
2372 {
2373 	__poll_t req_events = poll_requested_events(wait);
2374 	struct vb2_buffer *vb = NULL;
2375 	unsigned long flags;
2376 
2377 	/*
2378 	 * poll_wait() MUST be called on the first invocation on all the
2379 	 * potential queues of interest, even if we are not interested in their
2380 	 * events during this first call. Failure to do so will result in
2381 	 * queue's events to be ignored because the poll_table won't be capable
2382 	 * of adding new wait queues thereafter.
2383 	 */
2384 	poll_wait(file, &q->done_wq, wait);
2385 
2386 	if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
2387 		return 0;
2388 	if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
2389 		return 0;
2390 
2391 	/*
2392 	 * Start file I/O emulator only if streaming API has not been used yet.
2393 	 */
2394 	if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2395 		if (!q->is_output && (q->io_modes & VB2_READ) &&
2396 				(req_events & (EPOLLIN | EPOLLRDNORM))) {
2397 			if (__vb2_init_fileio(q, 1))
2398 				return EPOLLERR;
2399 		}
2400 		if (q->is_output && (q->io_modes & VB2_WRITE) &&
2401 				(req_events & (EPOLLOUT | EPOLLWRNORM))) {
2402 			if (__vb2_init_fileio(q, 0))
2403 				return EPOLLERR;
2404 			/*
2405 			 * Write to OUTPUT queue can be done immediately.
2406 			 */
2407 			return EPOLLOUT | EPOLLWRNORM;
2408 		}
2409 	}
2410 
2411 	/*
2412 	 * There is nothing to wait for if the queue isn't streaming, or if the
2413 	 * error flag is set.
2414 	 */
2415 	if (!vb2_is_streaming(q) || q->error)
2416 		return EPOLLERR;
2417 
2418 	/*
2419 	 * If this quirk is set and QBUF hasn't been called yet then
2420 	 * return EPOLLERR as well. This only affects capture queues, output
2421 	 * queues will always initialize waiting_for_buffers to false.
2422 	 * This quirk is set by V4L2 for backwards compatibility reasons.
2423 	 */
2424 	if (q->quirk_poll_must_check_waiting_for_buffers &&
2425 	    q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
2426 		return EPOLLERR;
2427 
2428 	/*
2429 	 * For output streams you can call write() as long as there are fewer
2430 	 * buffers queued than there are buffers available.
2431 	 */
2432 	if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2433 		return EPOLLOUT | EPOLLWRNORM;
2434 
2435 	if (list_empty(&q->done_list)) {
2436 		/*
2437 		 * If the last buffer was dequeued from a capture queue,
2438 		 * return immediately. DQBUF will return -EPIPE.
2439 		 */
2440 		if (q->last_buffer_dequeued)
2441 			return EPOLLIN | EPOLLRDNORM;
2442 	}
2443 
2444 	/*
2445 	 * Take first buffer available for dequeuing.
2446 	 */
2447 	spin_lock_irqsave(&q->done_lock, flags);
2448 	if (!list_empty(&q->done_list))
2449 		vb = list_first_entry(&q->done_list, struct vb2_buffer,
2450 					done_entry);
2451 	spin_unlock_irqrestore(&q->done_lock, flags);
2452 
2453 	if (vb && (vb->state == VB2_BUF_STATE_DONE
2454 			|| vb->state == VB2_BUF_STATE_ERROR)) {
2455 		return (q->is_output) ?
2456 				EPOLLOUT | EPOLLWRNORM :
2457 				EPOLLIN | EPOLLRDNORM;
2458 	}
2459 	return 0;
2460 }
2461 EXPORT_SYMBOL_GPL(vb2_core_poll);
2462 
2463 /*
2464  * struct vb2_fileio_buf - buffer context used by file io emulator
2465  *
2466  * vb2 provides a compatibility layer and emulator of file io (read and
2467  * write) calls on top of streaming API. This structure is used for
2468  * tracking context related to the buffers.
2469  */
2470 struct vb2_fileio_buf {
2471 	void *vaddr;
2472 	unsigned int size;
2473 	unsigned int pos;
2474 	unsigned int queued:1;
2475 };
2476 
2477 /*
2478  * struct vb2_fileio_data - queue context used by file io emulator
2479  *
2480  * @cur_index:	the index of the buffer currently being read from or
2481  *		written to. If equal to q->num_buffers then a new buffer
2482  *		must be dequeued.
2483  * @initial_index: in the read() case all buffers are queued up immediately
2484  *		in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2485  *		buffers. However, in the write() case no buffers are initially
2486  *		queued, instead whenever a buffer is full it is queued up by
2487  *		__vb2_perform_fileio(). Only once all available buffers have
2488  *		been queued up will __vb2_perform_fileio() start to dequeue
2489  *		buffers. This means that initially __vb2_perform_fileio()
2490  *		needs to know what buffer index to use when it is queuing up
2491  *		the buffers for the first time. That initial index is stored
2492  *		in this field. Once it is equal to q->num_buffers all
2493  *		available buffers have been queued and __vb2_perform_fileio()
2494  *		should start the normal dequeue/queue cycle.
2495  *
2496  * vb2 provides a compatibility layer and emulator of file io (read and
2497  * write) calls on top of streaming API. For proper operation it required
2498  * this structure to save the driver state between each call of the read
2499  * or write function.
2500  */
2501 struct vb2_fileio_data {
2502 	unsigned int count;
2503 	unsigned int type;
2504 	unsigned int memory;
2505 	struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2506 	unsigned int cur_index;
2507 	unsigned int initial_index;
2508 	unsigned int q_count;
2509 	unsigned int dq_count;
2510 	unsigned read_once:1;
2511 	unsigned write_immediately:1;
2512 };
2513 
2514 /*
2515  * __vb2_init_fileio() - initialize file io emulator
2516  * @q:		videobuf2 queue
2517  * @read:	mode selector (1 means read, 0 means write)
2518  */
2519 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2520 {
2521 	struct vb2_fileio_data *fileio;
2522 	int i, ret;
2523 	unsigned int count = 0;
2524 
2525 	/*
2526 	 * Sanity check
2527 	 */
2528 	if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2529 		    (!read && !(q->io_modes & VB2_WRITE))))
2530 		return -EINVAL;
2531 
2532 	/*
2533 	 * Check if device supports mapping buffers to kernel virtual space.
2534 	 */
2535 	if (!q->mem_ops->vaddr)
2536 		return -EBUSY;
2537 
2538 	/*
2539 	 * Check if streaming api has not been already activated.
2540 	 */
2541 	if (q->streaming || q->num_buffers > 0)
2542 		return -EBUSY;
2543 
2544 	/*
2545 	 * Start with count 1, driver can increase it in queue_setup()
2546 	 */
2547 	count = 1;
2548 
2549 	dprintk(q, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2550 		(read) ? "read" : "write", count, q->fileio_read_once,
2551 		q->fileio_write_immediately);
2552 
2553 	fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2554 	if (fileio == NULL)
2555 		return -ENOMEM;
2556 
2557 	fileio->read_once = q->fileio_read_once;
2558 	fileio->write_immediately = q->fileio_write_immediately;
2559 
2560 	/*
2561 	 * Request buffers and use MMAP type to force driver
2562 	 * to allocate buffers by itself.
2563 	 */
2564 	fileio->count = count;
2565 	fileio->memory = VB2_MEMORY_MMAP;
2566 	fileio->type = q->type;
2567 	q->fileio = fileio;
2568 	ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2569 	if (ret)
2570 		goto err_kfree;
2571 
2572 	/*
2573 	 * Check if plane_count is correct
2574 	 * (multiplane buffers are not supported).
2575 	 */
2576 	if (q->bufs[0]->num_planes != 1) {
2577 		ret = -EBUSY;
2578 		goto err_reqbufs;
2579 	}
2580 
2581 	/*
2582 	 * Get kernel address of each buffer.
2583 	 */
2584 	for (i = 0; i < q->num_buffers; i++) {
2585 		fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2586 		if (fileio->bufs[i].vaddr == NULL) {
2587 			ret = -EINVAL;
2588 			goto err_reqbufs;
2589 		}
2590 		fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2591 	}
2592 
2593 	/*
2594 	 * Read mode requires pre queuing of all buffers.
2595 	 */
2596 	if (read) {
2597 		/*
2598 		 * Queue all buffers.
2599 		 */
2600 		for (i = 0; i < q->num_buffers; i++) {
2601 			ret = vb2_core_qbuf(q, i, NULL, NULL);
2602 			if (ret)
2603 				goto err_reqbufs;
2604 			fileio->bufs[i].queued = 1;
2605 		}
2606 		/*
2607 		 * All buffers have been queued, so mark that by setting
2608 		 * initial_index to q->num_buffers
2609 		 */
2610 		fileio->initial_index = q->num_buffers;
2611 		fileio->cur_index = q->num_buffers;
2612 	}
2613 
2614 	/*
2615 	 * Start streaming.
2616 	 */
2617 	ret = vb2_core_streamon(q, q->type);
2618 	if (ret)
2619 		goto err_reqbufs;
2620 
2621 	return ret;
2622 
2623 err_reqbufs:
2624 	fileio->count = 0;
2625 	vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2626 
2627 err_kfree:
2628 	q->fileio = NULL;
2629 	kfree(fileio);
2630 	return ret;
2631 }
2632 
2633 /*
2634  * __vb2_cleanup_fileio() - free resourced used by file io emulator
2635  * @q:		videobuf2 queue
2636  */
2637 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2638 {
2639 	struct vb2_fileio_data *fileio = q->fileio;
2640 
2641 	if (fileio) {
2642 		vb2_core_streamoff(q, q->type);
2643 		q->fileio = NULL;
2644 		fileio->count = 0;
2645 		vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2646 		kfree(fileio);
2647 		dprintk(q, 3, "file io emulator closed\n");
2648 	}
2649 	return 0;
2650 }
2651 
2652 /*
2653  * __vb2_perform_fileio() - perform a single file io (read or write) operation
2654  * @q:		videobuf2 queue
2655  * @data:	pointed to target userspace buffer
2656  * @count:	number of bytes to read or write
2657  * @ppos:	file handle position tracking pointer
2658  * @nonblock:	mode selector (1 means blocking calls, 0 means nonblocking)
2659  * @read:	access mode selector (1 means read, 0 means write)
2660  */
2661 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2662 		loff_t *ppos, int nonblock, int read)
2663 {
2664 	struct vb2_fileio_data *fileio;
2665 	struct vb2_fileio_buf *buf;
2666 	bool is_multiplanar = q->is_multiplanar;
2667 	/*
2668 	 * When using write() to write data to an output video node the vb2 core
2669 	 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2670 	 * else is able to provide this information with the write() operation.
2671 	 */
2672 	bool copy_timestamp = !read && q->copy_timestamp;
2673 	unsigned index;
2674 	int ret;
2675 
2676 	dprintk(q, 3, "mode %s, offset %ld, count %zd, %sblocking\n",
2677 		read ? "read" : "write", (long)*ppos, count,
2678 		nonblock ? "non" : "");
2679 
2680 	if (!data)
2681 		return -EINVAL;
2682 
2683 	if (q->waiting_in_dqbuf) {
2684 		dprintk(q, 3, "another dup()ped fd is %s\n",
2685 			read ? "reading" : "writing");
2686 		return -EBUSY;
2687 	}
2688 
2689 	/*
2690 	 * Initialize emulator on first call.
2691 	 */
2692 	if (!vb2_fileio_is_active(q)) {
2693 		ret = __vb2_init_fileio(q, read);
2694 		dprintk(q, 3, "vb2_init_fileio result: %d\n", ret);
2695 		if (ret)
2696 			return ret;
2697 	}
2698 	fileio = q->fileio;
2699 
2700 	/*
2701 	 * Check if we need to dequeue the buffer.
2702 	 */
2703 	index = fileio->cur_index;
2704 	if (index >= q->num_buffers) {
2705 		struct vb2_buffer *b;
2706 
2707 		/*
2708 		 * Call vb2_dqbuf to get buffer back.
2709 		 */
2710 		ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2711 		dprintk(q, 5, "vb2_dqbuf result: %d\n", ret);
2712 		if (ret)
2713 			return ret;
2714 		fileio->dq_count += 1;
2715 
2716 		fileio->cur_index = index;
2717 		buf = &fileio->bufs[index];
2718 		b = q->bufs[index];
2719 
2720 		/*
2721 		 * Get number of bytes filled by the driver
2722 		 */
2723 		buf->pos = 0;
2724 		buf->queued = 0;
2725 		buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2726 				 : vb2_plane_size(q->bufs[index], 0);
2727 		/* Compensate for data_offset on read in the multiplanar case. */
2728 		if (is_multiplanar && read &&
2729 				b->planes[0].data_offset < buf->size) {
2730 			buf->pos = b->planes[0].data_offset;
2731 			buf->size -= buf->pos;
2732 		}
2733 	} else {
2734 		buf = &fileio->bufs[index];
2735 	}
2736 
2737 	/*
2738 	 * Limit count on last few bytes of the buffer.
2739 	 */
2740 	if (buf->pos + count > buf->size) {
2741 		count = buf->size - buf->pos;
2742 		dprintk(q, 5, "reducing read count: %zd\n", count);
2743 	}
2744 
2745 	/*
2746 	 * Transfer data to userspace.
2747 	 */
2748 	dprintk(q, 3, "copying %zd bytes - buffer %d, offset %u\n",
2749 		count, index, buf->pos);
2750 	if (read)
2751 		ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2752 	else
2753 		ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2754 	if (ret) {
2755 		dprintk(q, 3, "error copying data\n");
2756 		return -EFAULT;
2757 	}
2758 
2759 	/*
2760 	 * Update counters.
2761 	 */
2762 	buf->pos += count;
2763 	*ppos += count;
2764 
2765 	/*
2766 	 * Queue next buffer if required.
2767 	 */
2768 	if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2769 		struct vb2_buffer *b = q->bufs[index];
2770 
2771 		/*
2772 		 * Check if this is the last buffer to read.
2773 		 */
2774 		if (read && fileio->read_once && fileio->dq_count == 1) {
2775 			dprintk(q, 3, "read limit reached\n");
2776 			return __vb2_cleanup_fileio(q);
2777 		}
2778 
2779 		/*
2780 		 * Call vb2_qbuf and give buffer to the driver.
2781 		 */
2782 		b->planes[0].bytesused = buf->pos;
2783 
2784 		if (copy_timestamp)
2785 			b->timestamp = ktime_get_ns();
2786 		ret = vb2_core_qbuf(q, index, NULL, NULL);
2787 		dprintk(q, 5, "vb2_dbuf result: %d\n", ret);
2788 		if (ret)
2789 			return ret;
2790 
2791 		/*
2792 		 * Buffer has been queued, update the status
2793 		 */
2794 		buf->pos = 0;
2795 		buf->queued = 1;
2796 		buf->size = vb2_plane_size(q->bufs[index], 0);
2797 		fileio->q_count += 1;
2798 		/*
2799 		 * If we are queuing up buffers for the first time, then
2800 		 * increase initial_index by one.
2801 		 */
2802 		if (fileio->initial_index < q->num_buffers)
2803 			fileio->initial_index++;
2804 		/*
2805 		 * The next buffer to use is either a buffer that's going to be
2806 		 * queued for the first time (initial_index < q->num_buffers)
2807 		 * or it is equal to q->num_buffers, meaning that the next
2808 		 * time we need to dequeue a buffer since we've now queued up
2809 		 * all the 'first time' buffers.
2810 		 */
2811 		fileio->cur_index = fileio->initial_index;
2812 	}
2813 
2814 	/*
2815 	 * Return proper number of bytes processed.
2816 	 */
2817 	if (ret == 0)
2818 		ret = count;
2819 	return ret;
2820 }
2821 
2822 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2823 		loff_t *ppos, int nonblocking)
2824 {
2825 	return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2826 }
2827 EXPORT_SYMBOL_GPL(vb2_read);
2828 
2829 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2830 		loff_t *ppos, int nonblocking)
2831 {
2832 	return __vb2_perform_fileio(q, (char __user *) data, count,
2833 							ppos, nonblocking, 0);
2834 }
2835 EXPORT_SYMBOL_GPL(vb2_write);
2836 
2837 struct vb2_threadio_data {
2838 	struct task_struct *thread;
2839 	vb2_thread_fnc fnc;
2840 	void *priv;
2841 	bool stop;
2842 };
2843 
2844 static int vb2_thread(void *data)
2845 {
2846 	struct vb2_queue *q = data;
2847 	struct vb2_threadio_data *threadio = q->threadio;
2848 	bool copy_timestamp = false;
2849 	unsigned prequeue = 0;
2850 	unsigned index = 0;
2851 	int ret = 0;
2852 
2853 	if (q->is_output) {
2854 		prequeue = q->num_buffers;
2855 		copy_timestamp = q->copy_timestamp;
2856 	}
2857 
2858 	set_freezable();
2859 
2860 	for (;;) {
2861 		struct vb2_buffer *vb;
2862 
2863 		/*
2864 		 * Call vb2_dqbuf to get buffer back.
2865 		 */
2866 		if (prequeue) {
2867 			vb = q->bufs[index++];
2868 			prequeue--;
2869 		} else {
2870 			call_void_qop(q, wait_finish, q);
2871 			if (!threadio->stop)
2872 				ret = vb2_core_dqbuf(q, &index, NULL, 0);
2873 			call_void_qop(q, wait_prepare, q);
2874 			dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
2875 			if (!ret)
2876 				vb = q->bufs[index];
2877 		}
2878 		if (ret || threadio->stop)
2879 			break;
2880 		try_to_freeze();
2881 
2882 		if (vb->state != VB2_BUF_STATE_ERROR)
2883 			if (threadio->fnc(vb, threadio->priv))
2884 				break;
2885 		call_void_qop(q, wait_finish, q);
2886 		if (copy_timestamp)
2887 			vb->timestamp = ktime_get_ns();
2888 		if (!threadio->stop)
2889 			ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
2890 		call_void_qop(q, wait_prepare, q);
2891 		if (ret || threadio->stop)
2892 			break;
2893 	}
2894 
2895 	/* Hmm, linux becomes *very* unhappy without this ... */
2896 	while (!kthread_should_stop()) {
2897 		set_current_state(TASK_INTERRUPTIBLE);
2898 		schedule();
2899 	}
2900 	return 0;
2901 }
2902 
2903 /*
2904  * This function should not be used for anything else but the videobuf2-dvb
2905  * support. If you think you have another good use-case for this, then please
2906  * contact the linux-media mailinglist first.
2907  */
2908 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2909 		     const char *thread_name)
2910 {
2911 	struct vb2_threadio_data *threadio;
2912 	int ret = 0;
2913 
2914 	if (q->threadio)
2915 		return -EBUSY;
2916 	if (vb2_is_busy(q))
2917 		return -EBUSY;
2918 	if (WARN_ON(q->fileio))
2919 		return -EBUSY;
2920 
2921 	threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2922 	if (threadio == NULL)
2923 		return -ENOMEM;
2924 	threadio->fnc = fnc;
2925 	threadio->priv = priv;
2926 
2927 	ret = __vb2_init_fileio(q, !q->is_output);
2928 	dprintk(q, 3, "file io: vb2_init_fileio result: %d\n", ret);
2929 	if (ret)
2930 		goto nomem;
2931 	q->threadio = threadio;
2932 	threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2933 	if (IS_ERR(threadio->thread)) {
2934 		ret = PTR_ERR(threadio->thread);
2935 		threadio->thread = NULL;
2936 		goto nothread;
2937 	}
2938 	return 0;
2939 
2940 nothread:
2941 	__vb2_cleanup_fileio(q);
2942 nomem:
2943 	kfree(threadio);
2944 	return ret;
2945 }
2946 EXPORT_SYMBOL_GPL(vb2_thread_start);
2947 
2948 int vb2_thread_stop(struct vb2_queue *q)
2949 {
2950 	struct vb2_threadio_data *threadio = q->threadio;
2951 	int err;
2952 
2953 	if (threadio == NULL)
2954 		return 0;
2955 	threadio->stop = true;
2956 	/* Wake up all pending sleeps in the thread */
2957 	vb2_queue_error(q);
2958 	err = kthread_stop(threadio->thread);
2959 	__vb2_cleanup_fileio(q);
2960 	threadio->thread = NULL;
2961 	kfree(threadio);
2962 	q->threadio = NULL;
2963 	return err;
2964 }
2965 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2966 
2967 MODULE_DESCRIPTION("Media buffer core framework");
2968 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2969 MODULE_LICENSE("GPL");
2970