2 * videobuf2-core.c - video buffer 2 core framework
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
7 * Marek Szyprowski <m.szyprowski@samsung.com>
9 * The vb2_thread implementation was based on code from videobuf-dvb.c:
10 * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
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.
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19 #include <linux/err.h>
20 #include <linux/kernel.h>
21 #include <linux/module.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>
29 #include <media/videobuf2-core.h>
30 #include <media/v4l2-mc.h>
32 #include <trace/events/vb2.h>
35 module_param(debug
, int, 0644);
37 #define dprintk(q, level, fmt, arg...) \
40 pr_info("[%s] %s: " fmt, (q)->name, __func__, \
44 #ifdef CONFIG_VIDEO_ADV_DEBUG
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.
50 * This makes it easy to check that the 'init' and 'cleanup'
51 * (and variations thereof) stay balanced.
54 #define log_memop(vb, op) \
55 dprintk((vb)->vb2_queue, 2, "call_memop(%d, %s)%s\n", \
57 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
59 #define call_memop(vb, op, args...) \
61 struct vb2_queue *_q = (vb)->vb2_queue; \
65 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
67 (vb)->cnt_mem_ ## op++; \
71 #define call_ptr_memop(op, vb, args...) \
73 struct vb2_queue *_q = (vb)->vb2_queue; \
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++; \
83 #define call_void_memop(vb, op, args...) \
85 struct vb2_queue *_q = (vb)->vb2_queue; \
88 if (_q->mem_ops->op) \
89 _q->mem_ops->op(args); \
90 (vb)->cnt_mem_ ## op++; \
93 #define log_qop(q, op) \
94 dprintk(q, 2, "call_qop(%s)%s\n", #op, \
95 (q)->ops->op ? "" : " (nop)")
97 #define call_qop(q, op, args...) \
102 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
108 #define call_void_qop(q, op, args...) \
112 (q)->ops->op(args); \
116 #define log_vb_qop(vb, op, args...) \
117 dprintk((vb)->vb2_queue, 2, "call_vb_qop(%d, %s)%s\n", \
119 (vb)->vb2_queue->ops->op ? "" : " (nop)")
121 #define call_vb_qop(vb, op, args...) \
125 log_vb_qop(vb, op); \
126 err = (vb)->vb2_queue->ops->op ? \
127 (vb)->vb2_queue->ops->op(args) : 0; \
129 (vb)->cnt_ ## op++; \
133 #define call_void_vb_qop(vb, op, args...) \
135 log_vb_qop(vb, op); \
136 if ((vb)->vb2_queue->ops->op) \
137 (vb)->vb2_queue->ops->op(args); \
138 (vb)->cnt_ ## op++; \
143 #define call_memop(vb, op, args...) \
144 ((vb)->vb2_queue->mem_ops->op ? \
145 (vb)->vb2_queue->mem_ops->op(args) : 0)
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)
151 #define call_void_memop(vb, op, args...) \
153 if ((vb)->vb2_queue->mem_ops->op) \
154 (vb)->vb2_queue->mem_ops->op(args); \
157 #define call_qop(q, op, args...) \
158 ((q)->ops->op ? (q)->ops->op(args) : 0)
160 #define call_void_qop(q, op, args...) \
163 (q)->ops->op(args); \
166 #define call_vb_qop(vb, op, args...) \
167 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
169 #define call_void_vb_qop(vb, op, args...) \
171 if ((vb)->vb2_queue->ops->op) \
172 (vb)->vb2_queue->ops->op(args); \
177 #define call_bufop(q, op, args...) \
180 if (q && q->buf_ops && q->buf_ops->op) \
181 ret = q->buf_ops->op(args); \
185 #define call_void_bufop(q, op, args...) \
187 if (q && q->buf_ops && q->buf_ops->op) \
188 q->buf_ops->op(args); \
191 static void __vb2_queue_cancel(struct vb2_queue
*q
);
192 static void __enqueue_in_driver(struct vb2_buffer
*vb
);
194 static const char *vb2_state_name(enum vb2_buffer_state s
)
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",
206 if ((unsigned int)(s
) < ARRAY_SIZE(state_names
))
207 return state_names
[s
];
212 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
214 static int __vb2_buf_mem_alloc(struct vb2_buffer
*vb
)
216 struct vb2_queue
*q
= vb
->vb2_queue
;
222 * Allocate memory for all planes in this buffer
223 * NOTE: mmapped areas should be page aligned
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
);
229 /* Did it wrap around? */
230 if (size
< vb
->planes
[plane
].length
)
233 mem_priv
= call_ptr_memop(alloc
,
235 q
->alloc_devs
[plane
] ? : q
->dev
,
237 if (IS_ERR_OR_NULL(mem_priv
)) {
239 ret
= PTR_ERR(mem_priv
);
243 /* Associate allocator private data with this plane */
244 vb
->planes
[plane
].mem_priv
= mem_priv
;
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
;
259 * __vb2_buf_mem_free() - free memory of the given buffer
261 static void __vb2_buf_mem_free(struct vb2_buffer
*vb
)
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",
274 * __vb2_buf_userptr_put() - release userspace memory associated with
277 static void __vb2_buf_userptr_put(struct vb2_buffer
*vb
)
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
;
289 * __vb2_plane_dmabuf_put() - release memory associated with
290 * a DMABUF shared plane
292 static void __vb2_plane_dmabuf_put(struct vb2_buffer
*vb
, struct vb2_plane
*p
)
298 call_void_memop(vb
, unmap_dmabuf
, p
->mem_priv
);
300 call_void_memop(vb
, detach_dmabuf
, p
->mem_priv
);
301 dma_buf_put(p
->dbuf
);
308 * __vb2_buf_dmabuf_put() - release memory associated with
309 * a DMABUF shared buffer
311 static void __vb2_buf_dmabuf_put(struct vb2_buffer
*vb
)
315 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
316 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
320 * __vb2_buf_mem_prepare() - call ->prepare() on buffer's private memory
323 static void __vb2_buf_mem_prepare(struct vb2_buffer
*vb
)
330 if (vb
->need_cache_sync_on_prepare
) {
331 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
332 call_void_memop(vb
, prepare
,
333 vb
->planes
[plane
].mem_priv
);
339 * __vb2_buf_mem_finish() - call ->finish on buffer's private memory
342 static void __vb2_buf_mem_finish(struct vb2_buffer
*vb
)
349 if (vb
->need_cache_sync_on_finish
) {
350 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
351 call_void_memop(vb
, finish
,
352 vb
->planes
[plane
].mem_priv
);
358 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
361 static void __setup_offsets(struct vb2_buffer
*vb
)
363 struct vb2_queue
*q
= vb
->vb2_queue
;
365 unsigned long off
= 0;
368 struct vb2_buffer
*prev
= q
->bufs
[vb
->index
- 1];
369 struct vb2_plane
*p
= &prev
->planes
[prev
->num_planes
- 1];
371 off
= PAGE_ALIGN(p
->m
.offset
+ p
->length
);
374 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
375 vb
->planes
[plane
].m
.offset
= off
;
377 dprintk(q
, 3, "buffer %d, plane %d offset 0x%08lx\n",
378 vb
->index
, plane
, off
);
380 off
+= vb
->planes
[plane
].length
;
381 off
= PAGE_ALIGN(off
);
386 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
387 * video buffer memory for all buffers/planes on the queue and initializes the
390 * Returns the number of buffers successfully allocated.
392 static int __vb2_queue_alloc(struct vb2_queue
*q
, enum vb2_memory memory
,
393 unsigned int num_buffers
, unsigned int num_planes
,
394 const unsigned plane_sizes
[VB2_MAX_PLANES
])
396 unsigned int buffer
, plane
;
397 struct vb2_buffer
*vb
;
400 /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
401 num_buffers
= min_t(unsigned int, num_buffers
,
402 VB2_MAX_FRAME
- q
->num_buffers
);
404 for (buffer
= 0; buffer
< num_buffers
; ++buffer
) {
405 /* Allocate videobuf buffer structures */
406 vb
= kzalloc(q
->buf_struct_size
, GFP_KERNEL
);
408 dprintk(q
, 1, "memory alloc for buffer struct failed\n");
412 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
414 vb
->num_planes
= num_planes
;
415 vb
->index
= q
->num_buffers
+ buffer
;
419 * We need to set these flags here so that the videobuf2 core
420 * will call ->prepare()/->finish() cache sync/flush on vb2
421 * buffers when appropriate. However, we can avoid explicit
422 * ->prepare() and ->finish() cache sync for DMABUF buffers,
423 * because DMA exporter takes care of it.
425 if (q
->memory
!= VB2_MEMORY_DMABUF
) {
426 vb
->need_cache_sync_on_prepare
= 1;
427 vb
->need_cache_sync_on_finish
= 1;
429 for (plane
= 0; plane
< num_planes
; ++plane
) {
430 vb
->planes
[plane
].length
= plane_sizes
[plane
];
431 vb
->planes
[plane
].min_length
= plane_sizes
[plane
];
433 call_void_bufop(q
, init_buffer
, vb
);
435 q
->bufs
[vb
->index
] = vb
;
437 /* Allocate video buffer memory for the MMAP type */
438 if (memory
== VB2_MEMORY_MMAP
) {
439 ret
= __vb2_buf_mem_alloc(vb
);
441 dprintk(q
, 1, "failed allocating memory for buffer %d\n",
443 q
->bufs
[vb
->index
] = NULL
;
449 * Call the driver-provided buffer initialization
450 * callback, if given. An error in initialization
451 * results in queue setup failure.
453 ret
= call_vb_qop(vb
, buf_init
, vb
);
455 dprintk(q
, 1, "buffer %d %p initialization failed\n",
457 __vb2_buf_mem_free(vb
);
458 q
->bufs
[vb
->index
] = NULL
;
465 dprintk(q
, 3, "allocated %d buffers, %d plane(s) each\n",
472 * __vb2_free_mem() - release all video buffer memory for a given queue
474 static void __vb2_free_mem(struct vb2_queue
*q
, unsigned int buffers
)
477 struct vb2_buffer
*vb
;
479 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
481 vb
= q
->bufs
[buffer
];
485 /* Free MMAP buffers or release USERPTR buffers */
486 if (q
->memory
== VB2_MEMORY_MMAP
)
487 __vb2_buf_mem_free(vb
);
488 else if (q
->memory
== VB2_MEMORY_DMABUF
)
489 __vb2_buf_dmabuf_put(vb
);
491 __vb2_buf_userptr_put(vb
);
496 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
497 * related information, if no buffers are left return the queue to an
498 * uninitialized state. Might be called even if the queue has already been freed.
500 static int __vb2_queue_free(struct vb2_queue
*q
, unsigned int buffers
)
505 * Sanity check: when preparing a buffer the queue lock is released for
506 * a short while (see __buf_prepare for the details), which would allow
507 * a race with a reqbufs which can call this function. Removing the
508 * buffers from underneath __buf_prepare is obviously a bad idea, so we
509 * check if any of the buffers is in the state PREPARING, and if so we
510 * just return -EAGAIN.
512 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
514 if (q
->bufs
[buffer
] == NULL
)
516 if (q
->bufs
[buffer
]->state
== VB2_BUF_STATE_PREPARING
) {
517 dprintk(q
, 1, "preparing buffers, cannot free\n");
522 /* Call driver-provided cleanup function for each buffer, if provided */
523 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
525 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
527 if (vb
&& vb
->planes
[0].mem_priv
)
528 call_void_vb_qop(vb
, buf_cleanup
, vb
);
531 /* Release video buffer memory */
532 __vb2_free_mem(q
, buffers
);
534 #ifdef CONFIG_VIDEO_ADV_DEBUG
536 * Check that all the calls were balances during the life-time of this
537 * queue. If not (or if the debug level is 1 or up), then dump the
538 * counters to the kernel log.
540 if (q
->num_buffers
) {
541 bool unbalanced
= q
->cnt_start_streaming
!= q
->cnt_stop_streaming
||
542 q
->cnt_wait_prepare
!= q
->cnt_wait_finish
;
544 if (unbalanced
|| debug
) {
545 pr_info("counters for queue %p:%s\n", q
,
546 unbalanced
? " UNBALANCED!" : "");
547 pr_info(" setup: %u start_streaming: %u stop_streaming: %u\n",
548 q
->cnt_queue_setup
, q
->cnt_start_streaming
,
549 q
->cnt_stop_streaming
);
550 pr_info(" wait_prepare: %u wait_finish: %u\n",
551 q
->cnt_wait_prepare
, q
->cnt_wait_finish
);
553 q
->cnt_queue_setup
= 0;
554 q
->cnt_wait_prepare
= 0;
555 q
->cnt_wait_finish
= 0;
556 q
->cnt_start_streaming
= 0;
557 q
->cnt_stop_streaming
= 0;
559 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
560 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
561 bool unbalanced
= vb
->cnt_mem_alloc
!= vb
->cnt_mem_put
||
562 vb
->cnt_mem_prepare
!= vb
->cnt_mem_finish
||
563 vb
->cnt_mem_get_userptr
!= vb
->cnt_mem_put_userptr
||
564 vb
->cnt_mem_attach_dmabuf
!= vb
->cnt_mem_detach_dmabuf
||
565 vb
->cnt_mem_map_dmabuf
!= vb
->cnt_mem_unmap_dmabuf
||
566 vb
->cnt_buf_queue
!= vb
->cnt_buf_done
||
567 vb
->cnt_buf_prepare
!= vb
->cnt_buf_finish
||
568 vb
->cnt_buf_init
!= vb
->cnt_buf_cleanup
;
570 if (unbalanced
|| debug
) {
571 pr_info(" counters for queue %p, buffer %d:%s\n",
572 q
, buffer
, unbalanced
? " UNBALANCED!" : "");
573 pr_info(" buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
574 vb
->cnt_buf_init
, vb
->cnt_buf_cleanup
,
575 vb
->cnt_buf_prepare
, vb
->cnt_buf_finish
);
576 pr_info(" buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
577 vb
->cnt_buf_out_validate
, vb
->cnt_buf_queue
,
578 vb
->cnt_buf_done
, vb
->cnt_buf_request_complete
);
579 pr_info(" alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
580 vb
->cnt_mem_alloc
, vb
->cnt_mem_put
,
581 vb
->cnt_mem_prepare
, vb
->cnt_mem_finish
,
583 pr_info(" get_userptr: %u put_userptr: %u\n",
584 vb
->cnt_mem_get_userptr
, vb
->cnt_mem_put_userptr
);
585 pr_info(" attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
586 vb
->cnt_mem_attach_dmabuf
, vb
->cnt_mem_detach_dmabuf
,
587 vb
->cnt_mem_map_dmabuf
, vb
->cnt_mem_unmap_dmabuf
);
588 pr_info(" get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
589 vb
->cnt_mem_get_dmabuf
,
590 vb
->cnt_mem_num_users
,
597 /* Free videobuf buffers */
598 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
600 kfree(q
->bufs
[buffer
]);
601 q
->bufs
[buffer
] = NULL
;
604 q
->num_buffers
-= buffers
;
605 if (!q
->num_buffers
) {
606 q
->memory
= VB2_MEMORY_UNKNOWN
;
607 INIT_LIST_HEAD(&q
->queued_list
);
612 bool vb2_buffer_in_use(struct vb2_queue
*q
, struct vb2_buffer
*vb
)
615 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
616 void *mem_priv
= vb
->planes
[plane
].mem_priv
;
618 * If num_users() has not been provided, call_memop
619 * will return 0, apparently nobody cares about this
620 * case anyway. If num_users() returns more than 1,
621 * we are not the only user of the plane's memory.
623 if (mem_priv
&& call_memop(vb
, num_users
, mem_priv
) > 1)
628 EXPORT_SYMBOL(vb2_buffer_in_use
);
631 * __buffers_in_use() - return true if any buffers on the queue are in use and
632 * the queue cannot be freed (by the means of REQBUFS(0)) call
634 static bool __buffers_in_use(struct vb2_queue
*q
)
637 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
638 if (vb2_buffer_in_use(q
, q
->bufs
[buffer
]))
644 void vb2_core_querybuf(struct vb2_queue
*q
, unsigned int index
, void *pb
)
646 call_void_bufop(q
, fill_user_buffer
, q
->bufs
[index
], pb
);
648 EXPORT_SYMBOL_GPL(vb2_core_querybuf
);
651 * __verify_userptr_ops() - verify that all memory operations required for
652 * USERPTR queue type have been provided
654 static int __verify_userptr_ops(struct vb2_queue
*q
)
656 if (!(q
->io_modes
& VB2_USERPTR
) || !q
->mem_ops
->get_userptr
||
657 !q
->mem_ops
->put_userptr
)
664 * __verify_mmap_ops() - verify that all memory operations required for
665 * MMAP queue type have been provided
667 static int __verify_mmap_ops(struct vb2_queue
*q
)
669 if (!(q
->io_modes
& VB2_MMAP
) || !q
->mem_ops
->alloc
||
670 !q
->mem_ops
->put
|| !q
->mem_ops
->mmap
)
677 * __verify_dmabuf_ops() - verify that all memory operations required for
678 * DMABUF queue type have been provided
680 static int __verify_dmabuf_ops(struct vb2_queue
*q
)
682 if (!(q
->io_modes
& VB2_DMABUF
) || !q
->mem_ops
->attach_dmabuf
||
683 !q
->mem_ops
->detach_dmabuf
|| !q
->mem_ops
->map_dmabuf
||
684 !q
->mem_ops
->unmap_dmabuf
)
690 int vb2_verify_memory_type(struct vb2_queue
*q
,
691 enum vb2_memory memory
, unsigned int type
)
693 if (memory
!= VB2_MEMORY_MMAP
&& memory
!= VB2_MEMORY_USERPTR
&&
694 memory
!= VB2_MEMORY_DMABUF
) {
695 dprintk(q
, 1, "unsupported memory type\n");
699 if (type
!= q
->type
) {
700 dprintk(q
, 1, "requested type is incorrect\n");
705 * Make sure all the required memory ops for given memory type
708 if (memory
== VB2_MEMORY_MMAP
&& __verify_mmap_ops(q
)) {
709 dprintk(q
, 1, "MMAP for current setup unsupported\n");
713 if (memory
== VB2_MEMORY_USERPTR
&& __verify_userptr_ops(q
)) {
714 dprintk(q
, 1, "USERPTR for current setup unsupported\n");
718 if (memory
== VB2_MEMORY_DMABUF
&& __verify_dmabuf_ops(q
)) {
719 dprintk(q
, 1, "DMABUF for current setup unsupported\n");
724 * Place the busy tests at the end: -EBUSY can be ignored when
725 * create_bufs is called with count == 0, but count == 0 should still
726 * do the memory and type validation.
728 if (vb2_fileio_is_active(q
)) {
729 dprintk(q
, 1, "file io in progress\n");
734 EXPORT_SYMBOL(vb2_verify_memory_type
);
736 int vb2_core_reqbufs(struct vb2_queue
*q
, enum vb2_memory memory
,
739 unsigned int num_buffers
, allocated_buffers
, num_planes
= 0;
740 unsigned plane_sizes
[VB2_MAX_PLANES
] = { };
745 dprintk(q
, 1, "streaming active\n");
749 if (q
->waiting_in_dqbuf
&& *count
) {
750 dprintk(q
, 1, "another dup()ped fd is waiting for a buffer\n");
754 if (*count
== 0 || q
->num_buffers
!= 0 ||
755 (q
->memory
!= VB2_MEMORY_UNKNOWN
&& q
->memory
!= memory
)) {
757 * We already have buffers allocated, so first check if they
758 * are not in use and can be freed.
760 mutex_lock(&q
->mmap_lock
);
761 if (debug
&& q
->memory
== VB2_MEMORY_MMAP
&&
763 dprintk(q
, 1, "memory in use, orphaning buffers\n");
766 * Call queue_cancel to clean up any buffers in the
767 * QUEUED state which is possible if buffers were prepared or
768 * queued without ever calling STREAMON.
770 __vb2_queue_cancel(q
);
771 ret
= __vb2_queue_free(q
, q
->num_buffers
);
772 mutex_unlock(&q
->mmap_lock
);
777 * In case of REQBUFS(0) return immediately without calling
778 * driver's queue_setup() callback and allocating resources.
785 * Make sure the requested values and current defaults are sane.
787 WARN_ON(q
->min_buffers_needed
> VB2_MAX_FRAME
);
788 num_buffers
= max_t(unsigned int, *count
, q
->min_buffers_needed
);
789 num_buffers
= min_t(unsigned int, num_buffers
, VB2_MAX_FRAME
);
790 memset(q
->alloc_devs
, 0, sizeof(q
->alloc_devs
));
794 * Ask the driver how many buffers and planes per buffer it requires.
795 * Driver also sets the size and allocator context for each plane.
797 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
, &num_planes
,
798 plane_sizes
, q
->alloc_devs
);
802 /* Check that driver has set sane values */
803 if (WARN_ON(!num_planes
))
806 for (i
= 0; i
< num_planes
; i
++)
807 if (WARN_ON(!plane_sizes
[i
]))
810 /* Finally, allocate buffers and video memory */
812 __vb2_queue_alloc(q
, memory
, num_buffers
, num_planes
, plane_sizes
);
813 if (allocated_buffers
== 0) {
814 dprintk(q
, 1, "memory allocation failed\n");
819 * There is no point in continuing if we can't allocate the minimum
820 * number of buffers needed by this vb2_queue.
822 if (allocated_buffers
< q
->min_buffers_needed
)
826 * Check if driver can handle the allocated number of buffers.
828 if (!ret
&& allocated_buffers
< num_buffers
) {
829 num_buffers
= allocated_buffers
;
831 * num_planes is set by the previous queue_setup(), but since it
832 * signals to queue_setup() whether it is called from create_bufs()
833 * vs reqbufs() we zero it here to signal that queue_setup() is
834 * called for the reqbufs() case.
838 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
,
839 &num_planes
, plane_sizes
, q
->alloc_devs
);
841 if (!ret
&& allocated_buffers
< num_buffers
)
845 * Either the driver has accepted a smaller number of buffers,
846 * or .queue_setup() returned an error
850 mutex_lock(&q
->mmap_lock
);
851 q
->num_buffers
= allocated_buffers
;
855 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
856 * from q->num_buffers.
858 __vb2_queue_free(q
, allocated_buffers
);
859 mutex_unlock(&q
->mmap_lock
);
862 mutex_unlock(&q
->mmap_lock
);
865 * Return the number of successfully allocated buffers
868 *count
= allocated_buffers
;
869 q
->waiting_for_buffers
= !q
->is_output
;
873 EXPORT_SYMBOL_GPL(vb2_core_reqbufs
);
875 int vb2_core_create_bufs(struct vb2_queue
*q
, enum vb2_memory memory
,
877 unsigned int requested_planes
,
878 const unsigned int requested_sizes
[])
880 unsigned int num_planes
= 0, num_buffers
, allocated_buffers
;
881 unsigned plane_sizes
[VB2_MAX_PLANES
] = { };
884 if (q
->num_buffers
== VB2_MAX_FRAME
) {
885 dprintk(q
, 1, "maximum number of buffers already allocated\n");
889 if (!q
->num_buffers
) {
890 if (q
->waiting_in_dqbuf
&& *count
) {
891 dprintk(q
, 1, "another dup()ped fd is waiting for a buffer\n");
894 memset(q
->alloc_devs
, 0, sizeof(q
->alloc_devs
));
896 q
->waiting_for_buffers
= !q
->is_output
;
898 if (q
->memory
!= memory
) {
899 dprintk(q
, 1, "memory model mismatch\n");
904 num_buffers
= min(*count
, VB2_MAX_FRAME
- q
->num_buffers
);
906 if (requested_planes
&& requested_sizes
) {
907 num_planes
= requested_planes
;
908 memcpy(plane_sizes
, requested_sizes
, sizeof(plane_sizes
));
912 * Ask the driver, whether the requested number of buffers, planes per
913 * buffer and their sizes are acceptable
915 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
,
916 &num_planes
, plane_sizes
, q
->alloc_devs
);
920 /* Finally, allocate buffers and video memory */
921 allocated_buffers
= __vb2_queue_alloc(q
, memory
, num_buffers
,
922 num_planes
, plane_sizes
);
923 if (allocated_buffers
== 0) {
924 dprintk(q
, 1, "memory allocation failed\n");
929 * Check if driver can handle the so far allocated number of buffers.
931 if (allocated_buffers
< num_buffers
) {
932 num_buffers
= allocated_buffers
;
935 * q->num_buffers contains the total number of buffers, that the
936 * queue driver has set up
938 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
,
939 &num_planes
, plane_sizes
, q
->alloc_devs
);
941 if (!ret
&& allocated_buffers
< num_buffers
)
945 * Either the driver has accepted a smaller number of buffers,
946 * or .queue_setup() returned an error
950 mutex_lock(&q
->mmap_lock
);
951 q
->num_buffers
+= allocated_buffers
;
955 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
956 * from q->num_buffers.
958 __vb2_queue_free(q
, allocated_buffers
);
959 mutex_unlock(&q
->mmap_lock
);
962 mutex_unlock(&q
->mmap_lock
);
965 * Return the number of successfully allocated buffers
968 *count
= allocated_buffers
;
972 EXPORT_SYMBOL_GPL(vb2_core_create_bufs
);
974 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
)
976 if (plane_no
>= vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
979 return call_ptr_memop(vaddr
, vb
, vb
->planes
[plane_no
].mem_priv
);
982 EXPORT_SYMBOL_GPL(vb2_plane_vaddr
);
984 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
)
986 if (plane_no
>= vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
989 return call_ptr_memop(cookie
, vb
, vb
->planes
[plane_no
].mem_priv
);
991 EXPORT_SYMBOL_GPL(vb2_plane_cookie
);
993 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
)
995 struct vb2_queue
*q
= vb
->vb2_queue
;
998 if (WARN_ON(vb
->state
!= VB2_BUF_STATE_ACTIVE
))
1001 if (WARN_ON(state
!= VB2_BUF_STATE_DONE
&&
1002 state
!= VB2_BUF_STATE_ERROR
&&
1003 state
!= VB2_BUF_STATE_QUEUED
))
1004 state
= VB2_BUF_STATE_ERROR
;
1006 #ifdef CONFIG_VIDEO_ADV_DEBUG
1008 * Although this is not a callback, it still does have to balance
1009 * with the buf_queue op. So update this counter manually.
1013 dprintk(q
, 4, "done processing on buffer %d, state: %s\n",
1014 vb
->index
, vb2_state_name(state
));
1016 if (state
!= VB2_BUF_STATE_QUEUED
)
1017 __vb2_buf_mem_finish(vb
);
1019 spin_lock_irqsave(&q
->done_lock
, flags
);
1020 if (state
== VB2_BUF_STATE_QUEUED
) {
1021 vb
->state
= VB2_BUF_STATE_QUEUED
;
1023 /* Add the buffer to the done buffers list */
1024 list_add_tail(&vb
->done_entry
, &q
->done_list
);
1027 atomic_dec(&q
->owned_by_drv_count
);
1029 if (state
!= VB2_BUF_STATE_QUEUED
&& vb
->req_obj
.req
) {
1030 media_request_object_unbind(&vb
->req_obj
);
1031 media_request_object_put(&vb
->req_obj
);
1034 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1036 trace_vb2_buf_done(q
, vb
);
1039 case VB2_BUF_STATE_QUEUED
:
1042 /* Inform any processes that may be waiting for buffers */
1043 wake_up(&q
->done_wq
);
1047 EXPORT_SYMBOL_GPL(vb2_buffer_done
);
1049 void vb2_discard_done(struct vb2_queue
*q
)
1051 struct vb2_buffer
*vb
;
1052 unsigned long flags
;
1054 spin_lock_irqsave(&q
->done_lock
, flags
);
1055 list_for_each_entry(vb
, &q
->done_list
, done_entry
)
1056 vb
->state
= VB2_BUF_STATE_ERROR
;
1057 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1059 EXPORT_SYMBOL_GPL(vb2_discard_done
);
1062 * __prepare_mmap() - prepare an MMAP buffer
1064 static int __prepare_mmap(struct vb2_buffer
*vb
)
1068 ret
= call_bufop(vb
->vb2_queue
, fill_vb2_buffer
,
1070 return ret
? ret
: call_vb_qop(vb
, buf_prepare
, vb
);
1074 * __prepare_userptr() - prepare a USERPTR buffer
1076 static int __prepare_userptr(struct vb2_buffer
*vb
)
1078 struct vb2_plane planes
[VB2_MAX_PLANES
];
1079 struct vb2_queue
*q
= vb
->vb2_queue
;
1083 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1085 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1086 /* Copy relevant information provided by the userspace */
1087 ret
= call_bufop(vb
->vb2_queue
, fill_vb2_buffer
,
1092 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1093 /* Skip the plane if already verified */
1094 if (vb
->planes
[plane
].m
.userptr
&&
1095 vb
->planes
[plane
].m
.userptr
== planes
[plane
].m
.userptr
1096 && vb
->planes
[plane
].length
== planes
[plane
].length
)
1099 dprintk(q
, 3, "userspace address for plane %d changed, reacquiring memory\n",
1102 /* Check if the provided plane buffer is large enough */
1103 if (planes
[plane
].length
< vb
->planes
[plane
].min_length
) {
1104 dprintk(q
, 1, "provided buffer size %u is less than setup size %u for plane %d\n",
1105 planes
[plane
].length
,
1106 vb
->planes
[plane
].min_length
,
1112 /* Release previously acquired memory if present */
1113 if (vb
->planes
[plane
].mem_priv
) {
1116 vb
->copied_timestamp
= 0;
1117 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1119 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1122 vb
->planes
[plane
].mem_priv
= NULL
;
1123 vb
->planes
[plane
].bytesused
= 0;
1124 vb
->planes
[plane
].length
= 0;
1125 vb
->planes
[plane
].m
.userptr
= 0;
1126 vb
->planes
[plane
].data_offset
= 0;
1128 /* Acquire each plane's memory */
1129 mem_priv
= call_ptr_memop(get_userptr
,
1131 q
->alloc_devs
[plane
] ? : q
->dev
,
1132 planes
[plane
].m
.userptr
,
1133 planes
[plane
].length
);
1134 if (IS_ERR(mem_priv
)) {
1135 dprintk(q
, 1, "failed acquiring userspace memory for plane %d\n",
1137 ret
= PTR_ERR(mem_priv
);
1140 vb
->planes
[plane
].mem_priv
= mem_priv
;
1144 * Now that everything is in order, copy relevant information
1145 * provided by userspace.
1147 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1148 vb
->planes
[plane
].bytesused
= planes
[plane
].bytesused
;
1149 vb
->planes
[plane
].length
= planes
[plane
].length
;
1150 vb
->planes
[plane
].m
.userptr
= planes
[plane
].m
.userptr
;
1151 vb
->planes
[plane
].data_offset
= planes
[plane
].data_offset
;
1156 * One or more planes changed, so we must call buf_init to do
1157 * the driver-specific initialization on the newly acquired
1158 * buffer, if provided.
1160 ret
= call_vb_qop(vb
, buf_init
, vb
);
1162 dprintk(q
, 1, "buffer initialization failed\n");
1167 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1169 dprintk(q
, 1, "buffer preparation failed\n");
1170 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1176 /* In case of errors, release planes that were already acquired */
1177 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1178 if (vb
->planes
[plane
].mem_priv
)
1179 call_void_memop(vb
, put_userptr
,
1180 vb
->planes
[plane
].mem_priv
);
1181 vb
->planes
[plane
].mem_priv
= NULL
;
1182 vb
->planes
[plane
].m
.userptr
= 0;
1183 vb
->planes
[plane
].length
= 0;
1190 * __prepare_dmabuf() - prepare a DMABUF buffer
1192 static int __prepare_dmabuf(struct vb2_buffer
*vb
)
1194 struct vb2_plane planes
[VB2_MAX_PLANES
];
1195 struct vb2_queue
*q
= vb
->vb2_queue
;
1199 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1201 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1202 /* Copy relevant information provided by the userspace */
1203 ret
= call_bufop(vb
->vb2_queue
, fill_vb2_buffer
,
1208 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1209 struct dma_buf
*dbuf
= dma_buf_get(planes
[plane
].m
.fd
);
1211 if (IS_ERR_OR_NULL(dbuf
)) {
1212 dprintk(q
, 1, "invalid dmabuf fd for plane %d\n",
1218 /* use DMABUF size if length is not provided */
1219 if (planes
[plane
].length
== 0)
1220 planes
[plane
].length
= dbuf
->size
;
1222 if (planes
[plane
].length
< vb
->planes
[plane
].min_length
) {
1223 dprintk(q
, 1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1224 planes
[plane
].length
, plane
,
1225 vb
->planes
[plane
].min_length
);
1231 /* Skip the plane if already verified */
1232 if (dbuf
== vb
->planes
[plane
].dbuf
&&
1233 vb
->planes
[plane
].length
== planes
[plane
].length
) {
1238 dprintk(q
, 3, "buffer for plane %d changed\n", plane
);
1242 vb
->copied_timestamp
= 0;
1243 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1246 /* Release previously acquired memory if present */
1247 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
1248 vb
->planes
[plane
].bytesused
= 0;
1249 vb
->planes
[plane
].length
= 0;
1250 vb
->planes
[plane
].m
.fd
= 0;
1251 vb
->planes
[plane
].data_offset
= 0;
1253 /* Acquire each plane's memory */
1254 mem_priv
= call_ptr_memop(attach_dmabuf
,
1256 q
->alloc_devs
[plane
] ? : q
->dev
,
1258 planes
[plane
].length
);
1259 if (IS_ERR(mem_priv
)) {
1260 dprintk(q
, 1, "failed to attach dmabuf\n");
1261 ret
= PTR_ERR(mem_priv
);
1266 vb
->planes
[plane
].dbuf
= dbuf
;
1267 vb
->planes
[plane
].mem_priv
= mem_priv
;
1271 * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1272 * here instead just before the DMA, while queueing the buffer(s) so
1273 * userspace knows sooner rather than later if the dma-buf map fails.
1275 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1276 if (vb
->planes
[plane
].dbuf_mapped
)
1279 ret
= call_memop(vb
, map_dmabuf
, vb
->planes
[plane
].mem_priv
);
1281 dprintk(q
, 1, "failed to map dmabuf for plane %d\n",
1285 vb
->planes
[plane
].dbuf_mapped
= 1;
1289 * Now that everything is in order, copy relevant information
1290 * provided by userspace.
1292 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1293 vb
->planes
[plane
].bytesused
= planes
[plane
].bytesused
;
1294 vb
->planes
[plane
].length
= planes
[plane
].length
;
1295 vb
->planes
[plane
].m
.fd
= planes
[plane
].m
.fd
;
1296 vb
->planes
[plane
].data_offset
= planes
[plane
].data_offset
;
1301 * Call driver-specific initialization on the newly acquired buffer,
1304 ret
= call_vb_qop(vb
, buf_init
, vb
);
1306 dprintk(q
, 1, "buffer initialization failed\n");
1311 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1313 dprintk(q
, 1, "buffer preparation failed\n");
1314 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1320 /* In case of errors, release planes that were already acquired */
1321 __vb2_buf_dmabuf_put(vb
);
1327 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1329 static void __enqueue_in_driver(struct vb2_buffer
*vb
)
1331 struct vb2_queue
*q
= vb
->vb2_queue
;
1333 vb
->state
= VB2_BUF_STATE_ACTIVE
;
1334 atomic_inc(&q
->owned_by_drv_count
);
1336 trace_vb2_buf_queue(q
, vb
);
1338 call_void_vb_qop(vb
, buf_queue
, vb
);
1341 static int __buf_prepare(struct vb2_buffer
*vb
)
1343 struct vb2_queue
*q
= vb
->vb2_queue
;
1344 enum vb2_buffer_state orig_state
= vb
->state
;
1348 dprintk(q
, 1, "fatal error occurred on queue\n");
1354 WARN_ON(vb
->synced
);
1357 ret
= call_vb_qop(vb
, buf_out_validate
, vb
);
1359 dprintk(q
, 1, "buffer validation failed\n");
1364 vb
->state
= VB2_BUF_STATE_PREPARING
;
1366 switch (q
->memory
) {
1367 case VB2_MEMORY_MMAP
:
1368 ret
= __prepare_mmap(vb
);
1370 case VB2_MEMORY_USERPTR
:
1371 ret
= __prepare_userptr(vb
);
1373 case VB2_MEMORY_DMABUF
:
1374 ret
= __prepare_dmabuf(vb
);
1377 WARN(1, "Invalid queue type\n");
1383 dprintk(q
, 1, "buffer preparation failed: %d\n", ret
);
1384 vb
->state
= orig_state
;
1388 __vb2_buf_mem_prepare(vb
);
1390 vb
->state
= orig_state
;
1395 static int vb2_req_prepare(struct media_request_object
*obj
)
1397 struct vb2_buffer
*vb
= container_of(obj
, struct vb2_buffer
, req_obj
);
1400 if (WARN_ON(vb
->state
!= VB2_BUF_STATE_IN_REQUEST
))
1403 mutex_lock(vb
->vb2_queue
->lock
);
1404 ret
= __buf_prepare(vb
);
1405 mutex_unlock(vb
->vb2_queue
->lock
);
1409 static void __vb2_dqbuf(struct vb2_buffer
*vb
);
1411 static void vb2_req_unprepare(struct media_request_object
*obj
)
1413 struct vb2_buffer
*vb
= container_of(obj
, struct vb2_buffer
, req_obj
);
1415 mutex_lock(vb
->vb2_queue
->lock
);
1417 vb
->state
= VB2_BUF_STATE_IN_REQUEST
;
1418 mutex_unlock(vb
->vb2_queue
->lock
);
1419 WARN_ON(!vb
->req_obj
.req
);
1422 int vb2_core_qbuf(struct vb2_queue
*q
, unsigned int index
, void *pb
,
1423 struct media_request
*req
);
1425 static void vb2_req_queue(struct media_request_object
*obj
)
1427 struct vb2_buffer
*vb
= container_of(obj
, struct vb2_buffer
, req_obj
);
1429 mutex_lock(vb
->vb2_queue
->lock
);
1430 vb2_core_qbuf(vb
->vb2_queue
, vb
->index
, NULL
, NULL
);
1431 mutex_unlock(vb
->vb2_queue
->lock
);
1434 static void vb2_req_unbind(struct media_request_object
*obj
)
1436 struct vb2_buffer
*vb
= container_of(obj
, struct vb2_buffer
, req_obj
);
1438 if (vb
->state
== VB2_BUF_STATE_IN_REQUEST
)
1439 call_void_bufop(vb
->vb2_queue
, init_buffer
, vb
);
1442 static void vb2_req_release(struct media_request_object
*obj
)
1444 struct vb2_buffer
*vb
= container_of(obj
, struct vb2_buffer
, req_obj
);
1446 if (vb
->state
== VB2_BUF_STATE_IN_REQUEST
) {
1447 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
1449 media_request_put(vb
->request
);
1454 static const struct media_request_object_ops vb2_core_req_ops
= {
1455 .prepare
= vb2_req_prepare
,
1456 .unprepare
= vb2_req_unprepare
,
1457 .queue
= vb2_req_queue
,
1458 .unbind
= vb2_req_unbind
,
1459 .release
= vb2_req_release
,
1462 bool vb2_request_object_is_buffer(struct media_request_object
*obj
)
1464 return obj
->ops
== &vb2_core_req_ops
;
1466 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer
);
1468 unsigned int vb2_request_buffer_cnt(struct media_request
*req
)
1470 struct media_request_object
*obj
;
1471 unsigned long flags
;
1472 unsigned int buffer_cnt
= 0;
1474 spin_lock_irqsave(&req
->lock
, flags
);
1475 list_for_each_entry(obj
, &req
->objects
, list
)
1476 if (vb2_request_object_is_buffer(obj
))
1478 spin_unlock_irqrestore(&req
->lock
, flags
);
1482 EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt
);
1484 int vb2_core_prepare_buf(struct vb2_queue
*q
, unsigned int index
, void *pb
)
1486 struct vb2_buffer
*vb
;
1489 vb
= q
->bufs
[index
];
1490 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1491 dprintk(q
, 1, "invalid buffer state %s\n",
1492 vb2_state_name(vb
->state
));
1496 dprintk(q
, 1, "buffer already prepared\n");
1500 ret
= __buf_prepare(vb
);
1504 /* Fill buffer information for the userspace */
1505 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1507 dprintk(q
, 2, "prepare of buffer %d succeeded\n", vb
->index
);
1511 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf
);
1514 * vb2_start_streaming() - Attempt to start streaming.
1515 * @q: videobuf2 queue
1517 * Attempt to start streaming. When this function is called there must be
1518 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1519 * number of buffers required for the DMA engine to function). If the
1520 * @start_streaming op fails it is supposed to return all the driver-owned
1521 * buffers back to vb2 in state QUEUED. Check if that happened and if
1522 * not warn and reclaim them forcefully.
1524 static int vb2_start_streaming(struct vb2_queue
*q
)
1526 struct vb2_buffer
*vb
;
1530 * If any buffers were queued before streamon,
1531 * we can now pass them to driver for processing.
1533 list_for_each_entry(vb
, &q
->queued_list
, queued_entry
)
1534 __enqueue_in_driver(vb
);
1536 /* Tell the driver to start streaming */
1537 q
->start_streaming_called
= 1;
1538 ret
= call_qop(q
, start_streaming
, q
,
1539 atomic_read(&q
->owned_by_drv_count
));
1543 q
->start_streaming_called
= 0;
1545 dprintk(q
, 1, "driver refused to start streaming\n");
1547 * If you see this warning, then the driver isn't cleaning up properly
1548 * after a failed start_streaming(). See the start_streaming()
1549 * documentation in videobuf2-core.h for more information how buffers
1550 * should be returned to vb2 in start_streaming().
1552 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1556 * Forcefully reclaim buffers if the driver did not
1557 * correctly return them to vb2.
1559 for (i
= 0; i
< q
->num_buffers
; ++i
) {
1561 if (vb
->state
== VB2_BUF_STATE_ACTIVE
)
1562 vb2_buffer_done(vb
, VB2_BUF_STATE_QUEUED
);
1564 /* Must be zero now */
1565 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1568 * If done_list is not empty, then start_streaming() didn't call
1569 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1572 WARN_ON(!list_empty(&q
->done_list
));
1576 int vb2_core_qbuf(struct vb2_queue
*q
, unsigned int index
, void *pb
,
1577 struct media_request
*req
)
1579 struct vb2_buffer
*vb
;
1580 enum vb2_buffer_state orig_state
;
1584 dprintk(q
, 1, "fatal error occurred on queue\n");
1588 vb
= q
->bufs
[index
];
1590 if (!req
&& vb
->state
!= VB2_BUF_STATE_IN_REQUEST
&&
1591 q
->requires_requests
) {
1592 dprintk(q
, 1, "qbuf requires a request\n");
1596 if ((req
&& q
->uses_qbuf
) ||
1597 (!req
&& vb
->state
!= VB2_BUF_STATE_IN_REQUEST
&&
1598 q
->uses_requests
)) {
1599 dprintk(q
, 1, "queue in wrong mode (qbuf vs requests)\n");
1606 q
->uses_requests
= 1;
1607 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1608 dprintk(q
, 1, "buffer %d not in dequeued state\n",
1613 if (q
->is_output
&& !vb
->prepared
) {
1614 ret
= call_vb_qop(vb
, buf_out_validate
, vb
);
1616 dprintk(q
, 1, "buffer validation failed\n");
1621 media_request_object_init(&vb
->req_obj
);
1623 /* Make sure the request is in a safe state for updating. */
1624 ret
= media_request_lock_for_update(req
);
1627 ret
= media_request_object_bind(req
, &vb2_core_req_ops
,
1628 q
, true, &vb
->req_obj
);
1629 media_request_unlock_for_update(req
);
1633 vb
->state
= VB2_BUF_STATE_IN_REQUEST
;
1636 * Increment the refcount and store the request.
1637 * The request refcount is decremented again when the
1638 * buffer is dequeued. This is to prevent vb2_buffer_done()
1639 * from freeing the request from interrupt context, which can
1640 * happen if the application closed the request fd after
1641 * queueing the request.
1643 media_request_get(req
);
1646 /* Fill buffer information for the userspace */
1648 call_void_bufop(q
, copy_timestamp
, vb
, pb
);
1649 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1652 dprintk(q
, 2, "qbuf of buffer %d succeeded\n", vb
->index
);
1656 if (vb
->state
!= VB2_BUF_STATE_IN_REQUEST
)
1659 switch (vb
->state
) {
1660 case VB2_BUF_STATE_DEQUEUED
:
1661 case VB2_BUF_STATE_IN_REQUEST
:
1662 if (!vb
->prepared
) {
1663 ret
= __buf_prepare(vb
);
1668 case VB2_BUF_STATE_PREPARING
:
1669 dprintk(q
, 1, "buffer still being prepared\n");
1672 dprintk(q
, 1, "invalid buffer state %s\n",
1673 vb2_state_name(vb
->state
));
1678 * Add to the queued buffers list, a buffer will stay on it until
1679 * dequeued in dqbuf.
1681 orig_state
= vb
->state
;
1682 list_add_tail(&vb
->queued_entry
, &q
->queued_list
);
1684 q
->waiting_for_buffers
= false;
1685 vb
->state
= VB2_BUF_STATE_QUEUED
;
1688 call_void_bufop(q
, copy_timestamp
, vb
, pb
);
1690 trace_vb2_qbuf(q
, vb
);
1693 * If already streaming, give the buffer to driver for processing.
1694 * If not, the buffer will be given to driver on next streamon.
1696 if (q
->start_streaming_called
)
1697 __enqueue_in_driver(vb
);
1699 /* Fill buffer information for the userspace */
1701 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1704 * If streamon has been called, and we haven't yet called
1705 * start_streaming() since not enough buffers were queued, and
1706 * we now have reached the minimum number of queued buffers,
1707 * then we can finally call start_streaming().
1709 if (q
->streaming
&& !q
->start_streaming_called
&&
1710 q
->queued_count
>= q
->min_buffers_needed
) {
1711 ret
= vb2_start_streaming(q
);
1714 * Since vb2_core_qbuf will return with an error,
1715 * we should return it to state DEQUEUED since
1716 * the error indicates that the buffer wasn't queued.
1718 list_del(&vb
->queued_entry
);
1720 vb
->state
= orig_state
;
1725 dprintk(q
, 2, "qbuf of buffer %d succeeded\n", vb
->index
);
1728 EXPORT_SYMBOL_GPL(vb2_core_qbuf
);
1731 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1734 * Will sleep if required for nonblocking == false.
1736 static int __vb2_wait_for_done_vb(struct vb2_queue
*q
, int nonblocking
)
1739 * All operations on vb_done_list are performed under done_lock
1740 * spinlock protection. However, buffers may be removed from
1741 * it and returned to userspace only while holding both driver's
1742 * lock and the done_lock spinlock. Thus we can be sure that as
1743 * long as we hold the driver's lock, the list will remain not
1744 * empty if list_empty() check succeeds.
1750 if (q
->waiting_in_dqbuf
) {
1751 dprintk(q
, 1, "another dup()ped fd is waiting for a buffer\n");
1755 if (!q
->streaming
) {
1756 dprintk(q
, 1, "streaming off, will not wait for buffers\n");
1761 dprintk(q
, 1, "Queue in error state, will not wait for buffers\n");
1765 if (q
->last_buffer_dequeued
) {
1766 dprintk(q
, 3, "last buffer dequeued already, will not wait for buffers\n");
1770 if (!list_empty(&q
->done_list
)) {
1772 * Found a buffer that we were waiting for.
1778 dprintk(q
, 3, "nonblocking and no buffers to dequeue, will not wait\n");
1782 q
->waiting_in_dqbuf
= 1;
1784 * We are streaming and blocking, wait for another buffer to
1785 * become ready or for streamoff. Driver's lock is released to
1786 * allow streamoff or qbuf to be called while waiting.
1788 call_void_qop(q
, wait_prepare
, q
);
1791 * All locks have been released, it is safe to sleep now.
1793 dprintk(q
, 3, "will sleep waiting for buffers\n");
1794 ret
= wait_event_interruptible(q
->done_wq
,
1795 !list_empty(&q
->done_list
) || !q
->streaming
||
1799 * We need to reevaluate both conditions again after reacquiring
1800 * the locks or return an error if one occurred.
1802 call_void_qop(q
, wait_finish
, q
);
1803 q
->waiting_in_dqbuf
= 0;
1805 dprintk(q
, 1, "sleep was interrupted\n");
1813 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1815 * Will sleep if required for nonblocking == false.
1817 static int __vb2_get_done_vb(struct vb2_queue
*q
, struct vb2_buffer
**vb
,
1818 void *pb
, int nonblocking
)
1820 unsigned long flags
;
1824 * Wait for at least one buffer to become available on the done_list.
1826 ret
= __vb2_wait_for_done_vb(q
, nonblocking
);
1831 * Driver's lock has been held since we last verified that done_list
1832 * is not empty, so no need for another list_empty(done_list) check.
1834 spin_lock_irqsave(&q
->done_lock
, flags
);
1835 *vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
, done_entry
);
1837 * Only remove the buffer from done_list if all planes can be
1838 * handled. Some cases such as V4L2 file I/O and DVB have pb
1839 * == NULL; skip the check then as there's nothing to verify.
1842 ret
= call_bufop(q
, verify_planes_array
, *vb
, pb
);
1844 list_del(&(*vb
)->done_entry
);
1845 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1850 int vb2_wait_for_all_buffers(struct vb2_queue
*q
)
1852 if (!q
->streaming
) {
1853 dprintk(q
, 1, "streaming off, will not wait for buffers\n");
1857 if (q
->start_streaming_called
)
1858 wait_event(q
->done_wq
, !atomic_read(&q
->owned_by_drv_count
));
1861 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers
);
1864 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1866 static void __vb2_dqbuf(struct vb2_buffer
*vb
)
1868 struct vb2_queue
*q
= vb
->vb2_queue
;
1870 /* nothing to do if the buffer is already dequeued */
1871 if (vb
->state
== VB2_BUF_STATE_DEQUEUED
)
1874 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
1876 call_void_bufop(q
, init_buffer
, vb
);
1879 int vb2_core_dqbuf(struct vb2_queue
*q
, unsigned int *pindex
, void *pb
,
1882 struct vb2_buffer
*vb
= NULL
;
1885 ret
= __vb2_get_done_vb(q
, &vb
, pb
, nonblocking
);
1889 switch (vb
->state
) {
1890 case VB2_BUF_STATE_DONE
:
1891 dprintk(q
, 3, "returning done buffer\n");
1893 case VB2_BUF_STATE_ERROR
:
1894 dprintk(q
, 3, "returning done buffer with errors\n");
1897 dprintk(q
, 1, "invalid buffer state %s\n",
1898 vb2_state_name(vb
->state
));
1902 call_void_vb_qop(vb
, buf_finish
, vb
);
1906 *pindex
= vb
->index
;
1908 /* Fill buffer information for the userspace */
1910 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1912 /* Remove from videobuf queue */
1913 list_del(&vb
->queued_entry
);
1916 trace_vb2_dqbuf(q
, vb
);
1918 /* go back to dequeued state */
1921 if (WARN_ON(vb
->req_obj
.req
)) {
1922 media_request_object_unbind(&vb
->req_obj
);
1923 media_request_object_put(&vb
->req_obj
);
1926 media_request_put(vb
->request
);
1929 dprintk(q
, 2, "dqbuf of buffer %d, state: %s\n",
1930 vb
->index
, vb2_state_name(vb
->state
));
1935 EXPORT_SYMBOL_GPL(vb2_core_dqbuf
);
1938 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1940 * Removes all queued buffers from driver's queue and all buffers queued by
1941 * userspace from videobuf's queue. Returns to state after reqbufs.
1943 static void __vb2_queue_cancel(struct vb2_queue
*q
)
1948 * Tell driver to stop all transactions and release all queued
1951 if (q
->start_streaming_called
)
1952 call_void_qop(q
, stop_streaming
, q
);
1955 * If you see this warning, then the driver isn't cleaning up properly
1956 * in stop_streaming(). See the stop_streaming() documentation in
1957 * videobuf2-core.h for more information how buffers should be returned
1958 * to vb2 in stop_streaming().
1960 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1961 for (i
= 0; i
< q
->num_buffers
; ++i
)
1962 if (q
->bufs
[i
]->state
== VB2_BUF_STATE_ACTIVE
) {
1963 pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
1965 vb2_buffer_done(q
->bufs
[i
], VB2_BUF_STATE_ERROR
);
1967 /* Must be zero now */
1968 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1972 q
->start_streaming_called
= 0;
1973 q
->queued_count
= 0;
1975 q
->uses_requests
= 0;
1979 * Remove all buffers from videobuf's list...
1981 INIT_LIST_HEAD(&q
->queued_list
);
1983 * ...and done list; userspace will not receive any buffers it
1984 * has not already dequeued before initiating cancel.
1986 INIT_LIST_HEAD(&q
->done_list
);
1987 atomic_set(&q
->owned_by_drv_count
, 0);
1988 wake_up_all(&q
->done_wq
);
1991 * Reinitialize all buffers for next use.
1992 * Make sure to call buf_finish for any queued buffers. Normally
1993 * that's done in dqbuf, but that's not going to happen when we
1994 * cancel the whole queue. Note: this code belongs here, not in
1995 * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1996 * call to __fill_user_buffer() after buf_finish(). That order can't
1997 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1999 for (i
= 0; i
< q
->num_buffers
; ++i
) {
2000 struct vb2_buffer
*vb
= q
->bufs
[i
];
2001 struct media_request
*req
= vb
->req_obj
.req
;
2004 * If a request is associated with this buffer, then
2005 * call buf_request_cancel() to give the driver to complete()
2006 * related request objects. Otherwise those objects would
2010 enum media_request_state state
;
2011 unsigned long flags
;
2013 spin_lock_irqsave(&req
->lock
, flags
);
2015 spin_unlock_irqrestore(&req
->lock
, flags
);
2017 if (state
== MEDIA_REQUEST_STATE_QUEUED
)
2018 call_void_vb_qop(vb
, buf_request_complete
, vb
);
2021 __vb2_buf_mem_finish(vb
);
2024 call_void_vb_qop(vb
, buf_finish
, vb
);
2029 if (vb
->req_obj
.req
) {
2030 media_request_object_unbind(&vb
->req_obj
);
2031 media_request_object_put(&vb
->req_obj
);
2034 media_request_put(vb
->request
);
2036 vb
->copied_timestamp
= 0;
2040 int vb2_core_streamon(struct vb2_queue
*q
, unsigned int type
)
2044 if (type
!= q
->type
) {
2045 dprintk(q
, 1, "invalid stream type\n");
2050 dprintk(q
, 3, "already streaming\n");
2054 if (!q
->num_buffers
) {
2055 dprintk(q
, 1, "no buffers have been allocated\n");
2059 if (q
->num_buffers
< q
->min_buffers_needed
) {
2060 dprintk(q
, 1, "need at least %u allocated buffers\n",
2061 q
->min_buffers_needed
);
2066 * Tell driver to start streaming provided sufficient buffers
2069 if (q
->queued_count
>= q
->min_buffers_needed
) {
2070 ret
= v4l_vb2q_enable_media_source(q
);
2073 ret
= vb2_start_streaming(q
);
2080 dprintk(q
, 3, "successful\n");
2083 EXPORT_SYMBOL_GPL(vb2_core_streamon
);
2085 void vb2_queue_error(struct vb2_queue
*q
)
2089 wake_up_all(&q
->done_wq
);
2091 EXPORT_SYMBOL_GPL(vb2_queue_error
);
2093 int vb2_core_streamoff(struct vb2_queue
*q
, unsigned int type
)
2095 if (type
!= q
->type
) {
2096 dprintk(q
, 1, "invalid stream type\n");
2101 * Cancel will pause streaming and remove all buffers from the driver
2102 * and videobuf, effectively returning control over them to userspace.
2104 * Note that we do this even if q->streaming == 0: if you prepare or
2105 * queue buffers, and then call streamoff without ever having called
2106 * streamon, you would still expect those buffers to be returned to
2107 * their normal dequeued state.
2109 __vb2_queue_cancel(q
);
2110 q
->waiting_for_buffers
= !q
->is_output
;
2111 q
->last_buffer_dequeued
= false;
2113 dprintk(q
, 3, "successful\n");
2116 EXPORT_SYMBOL_GPL(vb2_core_streamoff
);
2119 * __find_plane_by_offset() - find plane associated with the given offset off
2121 static int __find_plane_by_offset(struct vb2_queue
*q
, unsigned long off
,
2122 unsigned int *_buffer
, unsigned int *_plane
)
2124 struct vb2_buffer
*vb
;
2125 unsigned int buffer
, plane
;
2128 * Go over all buffers and their planes, comparing the given offset
2129 * with an offset assigned to each plane. If a match is found,
2130 * return its buffer and plane numbers.
2132 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
2133 vb
= q
->bufs
[buffer
];
2135 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
2136 if (vb
->planes
[plane
].m
.offset
== off
) {
2147 int vb2_core_expbuf(struct vb2_queue
*q
, int *fd
, unsigned int type
,
2148 unsigned int index
, unsigned int plane
, unsigned int flags
)
2150 struct vb2_buffer
*vb
= NULL
;
2151 struct vb2_plane
*vb_plane
;
2153 struct dma_buf
*dbuf
;
2155 if (q
->memory
!= VB2_MEMORY_MMAP
) {
2156 dprintk(q
, 1, "queue is not currently set up for mmap\n");
2160 if (!q
->mem_ops
->get_dmabuf
) {
2161 dprintk(q
, 1, "queue does not support DMA buffer exporting\n");
2165 if (flags
& ~(O_CLOEXEC
| O_ACCMODE
)) {
2166 dprintk(q
, 1, "queue does support only O_CLOEXEC and access mode flags\n");
2170 if (type
!= q
->type
) {
2171 dprintk(q
, 1, "invalid buffer type\n");
2175 if (index
>= q
->num_buffers
) {
2176 dprintk(q
, 1, "buffer index out of range\n");
2180 vb
= q
->bufs
[index
];
2182 if (plane
>= vb
->num_planes
) {
2183 dprintk(q
, 1, "buffer plane out of range\n");
2187 if (vb2_fileio_is_active(q
)) {
2188 dprintk(q
, 1, "expbuf: file io in progress\n");
2192 vb_plane
= &vb
->planes
[plane
];
2194 dbuf
= call_ptr_memop(get_dmabuf
,
2198 if (IS_ERR_OR_NULL(dbuf
)) {
2199 dprintk(q
, 1, "failed to export buffer %d, plane %d\n",
2204 ret
= dma_buf_fd(dbuf
, flags
& ~O_ACCMODE
);
2206 dprintk(q
, 3, "buffer %d, plane %d failed to export (%d)\n",
2212 dprintk(q
, 3, "buffer %d, plane %d exported as %d descriptor\n",
2218 EXPORT_SYMBOL_GPL(vb2_core_expbuf
);
2220 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
)
2222 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
2223 struct vb2_buffer
*vb
;
2224 unsigned int buffer
= 0, plane
= 0;
2226 unsigned long length
;
2228 if (q
->memory
!= VB2_MEMORY_MMAP
) {
2229 dprintk(q
, 1, "queue is not currently set up for mmap\n");
2234 * Check memory area access mode.
2236 if (!(vma
->vm_flags
& VM_SHARED
)) {
2237 dprintk(q
, 1, "invalid vma flags, VM_SHARED needed\n");
2241 if (!(vma
->vm_flags
& VM_WRITE
)) {
2242 dprintk(q
, 1, "invalid vma flags, VM_WRITE needed\n");
2246 if (!(vma
->vm_flags
& VM_READ
)) {
2247 dprintk(q
, 1, "invalid vma flags, VM_READ needed\n");
2252 mutex_lock(&q
->mmap_lock
);
2254 if (vb2_fileio_is_active(q
)) {
2255 dprintk(q
, 1, "mmap: file io in progress\n");
2261 * Find the plane corresponding to the offset passed by userspace.
2263 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2267 vb
= q
->bufs
[buffer
];
2270 * MMAP requires page_aligned buffers.
2271 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2272 * so, we need to do the same here.
2274 length
= PAGE_ALIGN(vb
->planes
[plane
].length
);
2275 if (length
< (vma
->vm_end
- vma
->vm_start
)) {
2277 "MMAP invalid, as it would overflow buffer length\n");
2283 * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
2284 * not as a in-buffer offset. We always want to mmap a whole buffer
2285 * from its beginning.
2289 ret
= call_memop(vb
, mmap
, vb
->planes
[plane
].mem_priv
, vma
);
2292 mutex_unlock(&q
->mmap_lock
);
2296 dprintk(q
, 3, "buffer %d, plane %d successfully mapped\n", buffer
, plane
);
2299 EXPORT_SYMBOL_GPL(vb2_mmap
);
2302 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
2305 unsigned long pgoff
,
2306 unsigned long flags
)
2308 unsigned long off
= pgoff
<< PAGE_SHIFT
;
2309 struct vb2_buffer
*vb
;
2310 unsigned int buffer
, plane
;
2314 if (q
->memory
!= VB2_MEMORY_MMAP
) {
2315 dprintk(q
, 1, "queue is not currently set up for mmap\n");
2320 * Find the plane corresponding to the offset passed by userspace.
2322 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2326 vb
= q
->bufs
[buffer
];
2328 vaddr
= vb2_plane_vaddr(vb
, plane
);
2329 return vaddr
? (unsigned long)vaddr
: -EINVAL
;
2331 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area
);
2334 int vb2_core_queue_init(struct vb2_queue
*q
)
2341 WARN_ON(!q
->mem_ops
) ||
2342 WARN_ON(!q
->type
) ||
2343 WARN_ON(!q
->io_modes
) ||
2344 WARN_ON(!q
->ops
->queue_setup
) ||
2345 WARN_ON(!q
->ops
->buf_queue
))
2348 if (WARN_ON(q
->requires_requests
&& !q
->supports_requests
))
2351 INIT_LIST_HEAD(&q
->queued_list
);
2352 INIT_LIST_HEAD(&q
->done_list
);
2353 spin_lock_init(&q
->done_lock
);
2354 mutex_init(&q
->mmap_lock
);
2355 init_waitqueue_head(&q
->done_wq
);
2357 q
->memory
= VB2_MEMORY_UNKNOWN
;
2359 if (q
->buf_struct_size
== 0)
2360 q
->buf_struct_size
= sizeof(struct vb2_buffer
);
2362 if (q
->bidirectional
)
2363 q
->dma_dir
= DMA_BIDIRECTIONAL
;
2365 q
->dma_dir
= q
->is_output
? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
2367 if (q
->name
[0] == '\0')
2368 snprintf(q
->name
, sizeof(q
->name
), "%s-%p",
2369 q
->is_output
? "out" : "cap", q
);
2373 EXPORT_SYMBOL_GPL(vb2_core_queue_init
);
2375 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
);
2376 static int __vb2_cleanup_fileio(struct vb2_queue
*q
);
2377 void vb2_core_queue_release(struct vb2_queue
*q
)
2379 __vb2_cleanup_fileio(q
);
2380 __vb2_queue_cancel(q
);
2381 mutex_lock(&q
->mmap_lock
);
2382 __vb2_queue_free(q
, q
->num_buffers
);
2383 mutex_unlock(&q
->mmap_lock
);
2385 EXPORT_SYMBOL_GPL(vb2_core_queue_release
);
2387 __poll_t
vb2_core_poll(struct vb2_queue
*q
, struct file
*file
,
2390 __poll_t req_events
= poll_requested_events(wait
);
2391 struct vb2_buffer
*vb
= NULL
;
2392 unsigned long flags
;
2395 * poll_wait() MUST be called on the first invocation on all the
2396 * potential queues of interest, even if we are not interested in their
2397 * events during this first call. Failure to do so will result in
2398 * queue's events to be ignored because the poll_table won't be capable
2399 * of adding new wait queues thereafter.
2401 poll_wait(file
, &q
->done_wq
, wait
);
2403 if (!q
->is_output
&& !(req_events
& (EPOLLIN
| EPOLLRDNORM
)))
2405 if (q
->is_output
&& !(req_events
& (EPOLLOUT
| EPOLLWRNORM
)))
2409 * Start file I/O emulator only if streaming API has not been used yet.
2411 if (q
->num_buffers
== 0 && !vb2_fileio_is_active(q
)) {
2412 if (!q
->is_output
&& (q
->io_modes
& VB2_READ
) &&
2413 (req_events
& (EPOLLIN
| EPOLLRDNORM
))) {
2414 if (__vb2_init_fileio(q
, 1))
2417 if (q
->is_output
&& (q
->io_modes
& VB2_WRITE
) &&
2418 (req_events
& (EPOLLOUT
| EPOLLWRNORM
))) {
2419 if (__vb2_init_fileio(q
, 0))
2422 * Write to OUTPUT queue can be done immediately.
2424 return EPOLLOUT
| EPOLLWRNORM
;
2429 * There is nothing to wait for if the queue isn't streaming, or if the
2430 * error flag is set.
2432 if (!vb2_is_streaming(q
) || q
->error
)
2436 * If this quirk is set and QBUF hasn't been called yet then
2437 * return EPOLLERR as well. This only affects capture queues, output
2438 * queues will always initialize waiting_for_buffers to false.
2439 * This quirk is set by V4L2 for backwards compatibility reasons.
2441 if (q
->quirk_poll_must_check_waiting_for_buffers
&&
2442 q
->waiting_for_buffers
&& (req_events
& (EPOLLIN
| EPOLLRDNORM
)))
2446 * For output streams you can call write() as long as there are fewer
2447 * buffers queued than there are buffers available.
2449 if (q
->is_output
&& q
->fileio
&& q
->queued_count
< q
->num_buffers
)
2450 return EPOLLOUT
| EPOLLWRNORM
;
2452 if (list_empty(&q
->done_list
)) {
2454 * If the last buffer was dequeued from a capture queue,
2455 * return immediately. DQBUF will return -EPIPE.
2457 if (q
->last_buffer_dequeued
)
2458 return EPOLLIN
| EPOLLRDNORM
;
2462 * Take first buffer available for dequeuing.
2464 spin_lock_irqsave(&q
->done_lock
, flags
);
2465 if (!list_empty(&q
->done_list
))
2466 vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
,
2468 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2470 if (vb
&& (vb
->state
== VB2_BUF_STATE_DONE
2471 || vb
->state
== VB2_BUF_STATE_ERROR
)) {
2472 return (q
->is_output
) ?
2473 EPOLLOUT
| EPOLLWRNORM
:
2474 EPOLLIN
| EPOLLRDNORM
;
2478 EXPORT_SYMBOL_GPL(vb2_core_poll
);
2481 * struct vb2_fileio_buf - buffer context used by file io emulator
2483 * vb2 provides a compatibility layer and emulator of file io (read and
2484 * write) calls on top of streaming API. This structure is used for
2485 * tracking context related to the buffers.
2487 struct vb2_fileio_buf
{
2491 unsigned int queued
:1;
2495 * struct vb2_fileio_data - queue context used by file io emulator
2497 * @cur_index: the index of the buffer currently being read from or
2498 * written to. If equal to q->num_buffers then a new buffer
2500 * @initial_index: in the read() case all buffers are queued up immediately
2501 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2502 * buffers. However, in the write() case no buffers are initially
2503 * queued, instead whenever a buffer is full it is queued up by
2504 * __vb2_perform_fileio(). Only once all available buffers have
2505 * been queued up will __vb2_perform_fileio() start to dequeue
2506 * buffers. This means that initially __vb2_perform_fileio()
2507 * needs to know what buffer index to use when it is queuing up
2508 * the buffers for the first time. That initial index is stored
2509 * in this field. Once it is equal to q->num_buffers all
2510 * available buffers have been queued and __vb2_perform_fileio()
2511 * should start the normal dequeue/queue cycle.
2513 * vb2 provides a compatibility layer and emulator of file io (read and
2514 * write) calls on top of streaming API. For proper operation it required
2515 * this structure to save the driver state between each call of the read
2516 * or write function.
2518 struct vb2_fileio_data
{
2521 unsigned int memory
;
2522 struct vb2_fileio_buf bufs
[VB2_MAX_FRAME
];
2523 unsigned int cur_index
;
2524 unsigned int initial_index
;
2525 unsigned int q_count
;
2526 unsigned int dq_count
;
2527 unsigned read_once
:1;
2528 unsigned write_immediately
:1;
2532 * __vb2_init_fileio() - initialize file io emulator
2533 * @q: videobuf2 queue
2534 * @read: mode selector (1 means read, 0 means write)
2536 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
)
2538 struct vb2_fileio_data
*fileio
;
2540 unsigned int count
= 0;
2545 if (WARN_ON((read
&& !(q
->io_modes
& VB2_READ
)) ||
2546 (!read
&& !(q
->io_modes
& VB2_WRITE
))))
2550 * Check if device supports mapping buffers to kernel virtual space.
2552 if (!q
->mem_ops
->vaddr
)
2556 * Check if streaming api has not been already activated.
2558 if (q
->streaming
|| q
->num_buffers
> 0)
2562 * Start with count 1, driver can increase it in queue_setup()
2566 dprintk(q
, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2567 (read
) ? "read" : "write", count
, q
->fileio_read_once
,
2568 q
->fileio_write_immediately
);
2570 fileio
= kzalloc(sizeof(*fileio
), GFP_KERNEL
);
2574 fileio
->read_once
= q
->fileio_read_once
;
2575 fileio
->write_immediately
= q
->fileio_write_immediately
;
2578 * Request buffers and use MMAP type to force driver
2579 * to allocate buffers by itself.
2581 fileio
->count
= count
;
2582 fileio
->memory
= VB2_MEMORY_MMAP
;
2583 fileio
->type
= q
->type
;
2585 ret
= vb2_core_reqbufs(q
, fileio
->memory
, &fileio
->count
);
2590 * Check if plane_count is correct
2591 * (multiplane buffers are not supported).
2593 if (q
->bufs
[0]->num_planes
!= 1) {
2599 * Get kernel address of each buffer.
2601 for (i
= 0; i
< q
->num_buffers
; i
++) {
2602 fileio
->bufs
[i
].vaddr
= vb2_plane_vaddr(q
->bufs
[i
], 0);
2603 if (fileio
->bufs
[i
].vaddr
== NULL
) {
2607 fileio
->bufs
[i
].size
= vb2_plane_size(q
->bufs
[i
], 0);
2611 * Read mode requires pre queuing of all buffers.
2615 * Queue all buffers.
2617 for (i
= 0; i
< q
->num_buffers
; i
++) {
2618 ret
= vb2_core_qbuf(q
, i
, NULL
, NULL
);
2621 fileio
->bufs
[i
].queued
= 1;
2624 * All buffers have been queued, so mark that by setting
2625 * initial_index to q->num_buffers
2627 fileio
->initial_index
= q
->num_buffers
;
2628 fileio
->cur_index
= q
->num_buffers
;
2634 ret
= vb2_core_streamon(q
, q
->type
);
2642 vb2_core_reqbufs(q
, fileio
->memory
, &fileio
->count
);
2651 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2652 * @q: videobuf2 queue
2654 static int __vb2_cleanup_fileio(struct vb2_queue
*q
)
2656 struct vb2_fileio_data
*fileio
= q
->fileio
;
2659 vb2_core_streamoff(q
, q
->type
);
2662 vb2_core_reqbufs(q
, fileio
->memory
, &fileio
->count
);
2664 dprintk(q
, 3, "file io emulator closed\n");
2670 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2671 * @q: videobuf2 queue
2672 * @data: pointed to target userspace buffer
2673 * @count: number of bytes to read or write
2674 * @ppos: file handle position tracking pointer
2675 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2676 * @read: access mode selector (1 means read, 0 means write)
2678 static size_t __vb2_perform_fileio(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2679 loff_t
*ppos
, int nonblock
, int read
)
2681 struct vb2_fileio_data
*fileio
;
2682 struct vb2_fileio_buf
*buf
;
2683 bool is_multiplanar
= q
->is_multiplanar
;
2685 * When using write() to write data to an output video node the vb2 core
2686 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2687 * else is able to provide this information with the write() operation.
2689 bool copy_timestamp
= !read
&& q
->copy_timestamp
;
2693 dprintk(q
, 3, "mode %s, offset %ld, count %zd, %sblocking\n",
2694 read
? "read" : "write", (long)*ppos
, count
,
2695 nonblock
? "non" : "");
2700 if (q
->waiting_in_dqbuf
) {
2701 dprintk(q
, 3, "another dup()ped fd is %s\n",
2702 read
? "reading" : "writing");
2707 * Initialize emulator on first call.
2709 if (!vb2_fileio_is_active(q
)) {
2710 ret
= __vb2_init_fileio(q
, read
);
2711 dprintk(q
, 3, "vb2_init_fileio result: %d\n", ret
);
2718 * Check if we need to dequeue the buffer.
2720 index
= fileio
->cur_index
;
2721 if (index
>= q
->num_buffers
) {
2722 struct vb2_buffer
*b
;
2725 * Call vb2_dqbuf to get buffer back.
2727 ret
= vb2_core_dqbuf(q
, &index
, NULL
, nonblock
);
2728 dprintk(q
, 5, "vb2_dqbuf result: %d\n", ret
);
2731 fileio
->dq_count
+= 1;
2733 fileio
->cur_index
= index
;
2734 buf
= &fileio
->bufs
[index
];
2738 * Get number of bytes filled by the driver
2742 buf
->size
= read
? vb2_get_plane_payload(q
->bufs
[index
], 0)
2743 : vb2_plane_size(q
->bufs
[index
], 0);
2744 /* Compensate for data_offset on read in the multiplanar case. */
2745 if (is_multiplanar
&& read
&&
2746 b
->planes
[0].data_offset
< buf
->size
) {
2747 buf
->pos
= b
->planes
[0].data_offset
;
2748 buf
->size
-= buf
->pos
;
2751 buf
= &fileio
->bufs
[index
];
2755 * Limit count on last few bytes of the buffer.
2757 if (buf
->pos
+ count
> buf
->size
) {
2758 count
= buf
->size
- buf
->pos
;
2759 dprintk(q
, 5, "reducing read count: %zd\n", count
);
2763 * Transfer data to userspace.
2765 dprintk(q
, 3, "copying %zd bytes - buffer %d, offset %u\n",
2766 count
, index
, buf
->pos
);
2768 ret
= copy_to_user(data
, buf
->vaddr
+ buf
->pos
, count
);
2770 ret
= copy_from_user(buf
->vaddr
+ buf
->pos
, data
, count
);
2772 dprintk(q
, 3, "error copying data\n");
2783 * Queue next buffer if required.
2785 if (buf
->pos
== buf
->size
|| (!read
&& fileio
->write_immediately
)) {
2786 struct vb2_buffer
*b
= q
->bufs
[index
];
2789 * Check if this is the last buffer to read.
2791 if (read
&& fileio
->read_once
&& fileio
->dq_count
== 1) {
2792 dprintk(q
, 3, "read limit reached\n");
2793 return __vb2_cleanup_fileio(q
);
2797 * Call vb2_qbuf and give buffer to the driver.
2799 b
->planes
[0].bytesused
= buf
->pos
;
2802 b
->timestamp
= ktime_get_ns();
2803 ret
= vb2_core_qbuf(q
, index
, NULL
, NULL
);
2804 dprintk(q
, 5, "vb2_dbuf result: %d\n", ret
);
2809 * Buffer has been queued, update the status
2813 buf
->size
= vb2_plane_size(q
->bufs
[index
], 0);
2814 fileio
->q_count
+= 1;
2816 * If we are queuing up buffers for the first time, then
2817 * increase initial_index by one.
2819 if (fileio
->initial_index
< q
->num_buffers
)
2820 fileio
->initial_index
++;
2822 * The next buffer to use is either a buffer that's going to be
2823 * queued for the first time (initial_index < q->num_buffers)
2824 * or it is equal to q->num_buffers, meaning that the next
2825 * time we need to dequeue a buffer since we've now queued up
2826 * all the 'first time' buffers.
2828 fileio
->cur_index
= fileio
->initial_index
;
2832 * Return proper number of bytes processed.
2839 size_t vb2_read(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2840 loff_t
*ppos
, int nonblocking
)
2842 return __vb2_perform_fileio(q
, data
, count
, ppos
, nonblocking
, 1);
2844 EXPORT_SYMBOL_GPL(vb2_read
);
2846 size_t vb2_write(struct vb2_queue
*q
, const char __user
*data
, size_t count
,
2847 loff_t
*ppos
, int nonblocking
)
2849 return __vb2_perform_fileio(q
, (char __user
*) data
, count
,
2850 ppos
, nonblocking
, 0);
2852 EXPORT_SYMBOL_GPL(vb2_write
);
2854 struct vb2_threadio_data
{
2855 struct task_struct
*thread
;
2861 static int vb2_thread(void *data
)
2863 struct vb2_queue
*q
= data
;
2864 struct vb2_threadio_data
*threadio
= q
->threadio
;
2865 bool copy_timestamp
= false;
2866 unsigned prequeue
= 0;
2871 prequeue
= q
->num_buffers
;
2872 copy_timestamp
= q
->copy_timestamp
;
2878 struct vb2_buffer
*vb
;
2881 * Call vb2_dqbuf to get buffer back.
2884 vb
= q
->bufs
[index
++];
2887 call_void_qop(q
, wait_finish
, q
);
2888 if (!threadio
->stop
)
2889 ret
= vb2_core_dqbuf(q
, &index
, NULL
, 0);
2890 call_void_qop(q
, wait_prepare
, q
);
2891 dprintk(q
, 5, "file io: vb2_dqbuf result: %d\n", ret
);
2893 vb
= q
->bufs
[index
];
2895 if (ret
|| threadio
->stop
)
2899 if (vb
->state
!= VB2_BUF_STATE_ERROR
)
2900 if (threadio
->fnc(vb
, threadio
->priv
))
2902 call_void_qop(q
, wait_finish
, q
);
2904 vb
->timestamp
= ktime_get_ns();
2905 if (!threadio
->stop
)
2906 ret
= vb2_core_qbuf(q
, vb
->index
, NULL
, NULL
);
2907 call_void_qop(q
, wait_prepare
, q
);
2908 if (ret
|| threadio
->stop
)
2912 /* Hmm, linux becomes *very* unhappy without this ... */
2913 while (!kthread_should_stop()) {
2914 set_current_state(TASK_INTERRUPTIBLE
);
2921 * This function should not be used for anything else but the videobuf2-dvb
2922 * support. If you think you have another good use-case for this, then please
2923 * contact the linux-media mailinglist first.
2925 int vb2_thread_start(struct vb2_queue
*q
, vb2_thread_fnc fnc
, void *priv
,
2926 const char *thread_name
)
2928 struct vb2_threadio_data
*threadio
;
2935 if (WARN_ON(q
->fileio
))
2938 threadio
= kzalloc(sizeof(*threadio
), GFP_KERNEL
);
2939 if (threadio
== NULL
)
2941 threadio
->fnc
= fnc
;
2942 threadio
->priv
= priv
;
2944 ret
= __vb2_init_fileio(q
, !q
->is_output
);
2945 dprintk(q
, 3, "file io: vb2_init_fileio result: %d\n", ret
);
2948 q
->threadio
= threadio
;
2949 threadio
->thread
= kthread_run(vb2_thread
, q
, "vb2-%s", thread_name
);
2950 if (IS_ERR(threadio
->thread
)) {
2951 ret
= PTR_ERR(threadio
->thread
);
2952 threadio
->thread
= NULL
;
2958 __vb2_cleanup_fileio(q
);
2963 EXPORT_SYMBOL_GPL(vb2_thread_start
);
2965 int vb2_thread_stop(struct vb2_queue
*q
)
2967 struct vb2_threadio_data
*threadio
= q
->threadio
;
2970 if (threadio
== NULL
)
2972 threadio
->stop
= true;
2973 /* Wake up all pending sleeps in the thread */
2975 err
= kthread_stop(threadio
->thread
);
2976 __vb2_cleanup_fileio(q
);
2977 threadio
->thread
= NULL
;
2982 EXPORT_SYMBOL_GPL(vb2_thread_stop
);
2984 MODULE_DESCRIPTION("Media buffer core framework");
2985 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2986 MODULE_LICENSE("GPL");