2 * videobuf2-core.c - V4L2 driver helper 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 #include <linux/err.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
21 #include <linux/poll.h>
22 #include <linux/slab.h>
23 #include <linux/sched.h>
24 #include <linux/freezer.h>
25 #include <linux/kthread.h>
27 #include <media/v4l2-dev.h>
28 #include <media/v4l2-fh.h>
29 #include <media/v4l2-event.h>
30 #include <media/v4l2-common.h>
31 #include <media/videobuf2-core.h>
34 module_param(debug
, int, 0644);
36 #define dprintk(level, fmt, arg...) \
39 pr_debug("vb2: %s: " fmt, __func__, ## arg); \
42 #ifdef CONFIG_VIDEO_ADV_DEBUG
45 * If advanced debugging is on, then count how often each op is called
46 * successfully, which can either be per-buffer or per-queue.
48 * This makes it easy to check that the 'init' and 'cleanup'
49 * (and variations thereof) stay balanced.
52 #define log_memop(vb, op) \
53 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
54 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
55 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
57 #define call_memop(vb, op, args...) \
59 struct vb2_queue *_q = (vb)->vb2_queue; \
63 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
65 (vb)->cnt_mem_ ## op++; \
69 #define call_ptr_memop(vb, op, args...) \
71 struct vb2_queue *_q = (vb)->vb2_queue; \
75 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
76 if (!IS_ERR_OR_NULL(ptr)) \
77 (vb)->cnt_mem_ ## op++; \
81 #define call_void_memop(vb, op, args...) \
83 struct vb2_queue *_q = (vb)->vb2_queue; \
86 if (_q->mem_ops->op) \
87 _q->mem_ops->op(args); \
88 (vb)->cnt_mem_ ## op++; \
91 #define log_qop(q, op) \
92 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
93 (q)->ops->op ? "" : " (nop)")
95 #define call_qop(q, op, args...) \
100 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
106 #define call_void_qop(q, op, args...) \
110 (q)->ops->op(args); \
114 #define log_vb_qop(vb, op, args...) \
115 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
116 (vb)->vb2_queue, (vb)->v4l2_buf.index, #op, \
117 (vb)->vb2_queue->ops->op ? "" : " (nop)")
119 #define call_vb_qop(vb, op, args...) \
123 log_vb_qop(vb, op); \
124 err = (vb)->vb2_queue->ops->op ? \
125 (vb)->vb2_queue->ops->op(args) : 0; \
127 (vb)->cnt_ ## op++; \
131 #define call_void_vb_qop(vb, op, args...) \
133 log_vb_qop(vb, op); \
134 if ((vb)->vb2_queue->ops->op) \
135 (vb)->vb2_queue->ops->op(args); \
136 (vb)->cnt_ ## op++; \
141 #define call_memop(vb, op, args...) \
142 ((vb)->vb2_queue->mem_ops->op ? \
143 (vb)->vb2_queue->mem_ops->op(args) : 0)
145 #define call_ptr_memop(vb, op, args...) \
146 ((vb)->vb2_queue->mem_ops->op ? \
147 (vb)->vb2_queue->mem_ops->op(args) : NULL)
149 #define call_void_memop(vb, op, args...) \
151 if ((vb)->vb2_queue->mem_ops->op) \
152 (vb)->vb2_queue->mem_ops->op(args); \
155 #define call_qop(q, op, args...) \
156 ((q)->ops->op ? (q)->ops->op(args) : 0)
158 #define call_void_qop(q, op, args...) \
161 (q)->ops->op(args); \
164 #define call_vb_qop(vb, op, args...) \
165 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
167 #define call_void_vb_qop(vb, op, args...) \
169 if ((vb)->vb2_queue->ops->op) \
170 (vb)->vb2_queue->ops->op(args); \
175 /* Flags that are set by the vb2 core */
176 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
177 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
178 V4L2_BUF_FLAG_PREPARED | \
179 V4L2_BUF_FLAG_TIMESTAMP_MASK)
180 /* Output buffer flags that should be passed on to the driver */
181 #define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
182 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
184 static void __vb2_queue_cancel(struct vb2_queue
*q
);
187 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
189 static int __vb2_buf_mem_alloc(struct vb2_buffer
*vb
)
191 struct vb2_queue
*q
= vb
->vb2_queue
;
196 * Allocate memory for all planes in this buffer
197 * NOTE: mmapped areas should be page aligned
199 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
200 unsigned long size
= PAGE_ALIGN(q
->plane_sizes
[plane
]);
202 mem_priv
= call_ptr_memop(vb
, alloc
, q
->alloc_ctx
[plane
],
204 if (IS_ERR_OR_NULL(mem_priv
))
207 /* Associate allocator private data with this plane */
208 vb
->planes
[plane
].mem_priv
= mem_priv
;
209 vb
->v4l2_planes
[plane
].length
= q
->plane_sizes
[plane
];
214 /* Free already allocated memory if one of the allocations failed */
215 for (; plane
> 0; --plane
) {
216 call_void_memop(vb
, put
, vb
->planes
[plane
- 1].mem_priv
);
217 vb
->planes
[plane
- 1].mem_priv
= NULL
;
224 * __vb2_buf_mem_free() - free memory of the given buffer
226 static void __vb2_buf_mem_free(struct vb2_buffer
*vb
)
230 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
231 call_void_memop(vb
, put
, vb
->planes
[plane
].mem_priv
);
232 vb
->planes
[plane
].mem_priv
= NULL
;
233 dprintk(3, "freed plane %d of buffer %d\n", plane
,
239 * __vb2_buf_userptr_put() - release userspace memory associated with
242 static void __vb2_buf_userptr_put(struct vb2_buffer
*vb
)
246 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
247 if (vb
->planes
[plane
].mem_priv
)
248 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
249 vb
->planes
[plane
].mem_priv
= NULL
;
254 * __vb2_plane_dmabuf_put() - release memory associated with
255 * a DMABUF shared plane
257 static void __vb2_plane_dmabuf_put(struct vb2_buffer
*vb
, struct vb2_plane
*p
)
263 call_void_memop(vb
, unmap_dmabuf
, p
->mem_priv
);
265 call_void_memop(vb
, detach_dmabuf
, p
->mem_priv
);
266 dma_buf_put(p
->dbuf
);
267 memset(p
, 0, sizeof(*p
));
271 * __vb2_buf_dmabuf_put() - release memory associated with
272 * a DMABUF shared buffer
274 static void __vb2_buf_dmabuf_put(struct vb2_buffer
*vb
)
278 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
279 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
283 * __setup_lengths() - setup initial lengths for every plane in
284 * every buffer on the queue
286 static void __setup_lengths(struct vb2_queue
*q
, unsigned int n
)
288 unsigned int buffer
, plane
;
289 struct vb2_buffer
*vb
;
291 for (buffer
= q
->num_buffers
; buffer
< q
->num_buffers
+ n
; ++buffer
) {
292 vb
= q
->bufs
[buffer
];
296 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
297 vb
->v4l2_planes
[plane
].length
= q
->plane_sizes
[plane
];
302 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
303 * every buffer on the queue
305 static void __setup_offsets(struct vb2_queue
*q
, unsigned int n
)
307 unsigned int buffer
, plane
;
308 struct vb2_buffer
*vb
;
311 if (q
->num_buffers
) {
312 struct v4l2_plane
*p
;
313 vb
= q
->bufs
[q
->num_buffers
- 1];
314 p
= &vb
->v4l2_planes
[vb
->num_planes
- 1];
315 off
= PAGE_ALIGN(p
->m
.mem_offset
+ p
->length
);
320 for (buffer
= q
->num_buffers
; buffer
< q
->num_buffers
+ n
; ++buffer
) {
321 vb
= q
->bufs
[buffer
];
325 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
326 vb
->v4l2_planes
[plane
].m
.mem_offset
= off
;
328 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
331 off
+= vb
->v4l2_planes
[plane
].length
;
332 off
= PAGE_ALIGN(off
);
338 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
339 * video buffer memory for all buffers/planes on the queue and initializes the
342 * Returns the number of buffers successfully allocated.
344 static int __vb2_queue_alloc(struct vb2_queue
*q
, enum v4l2_memory memory
,
345 unsigned int num_buffers
, unsigned int num_planes
)
348 struct vb2_buffer
*vb
;
351 for (buffer
= 0; buffer
< num_buffers
; ++buffer
) {
352 /* Allocate videobuf buffer structures */
353 vb
= kzalloc(q
->buf_struct_size
, GFP_KERNEL
);
355 dprintk(1, "memory alloc for buffer struct failed\n");
359 /* Length stores number of planes for multiplanar buffers */
360 if (V4L2_TYPE_IS_MULTIPLANAR(q
->type
))
361 vb
->v4l2_buf
.length
= num_planes
;
363 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
365 vb
->num_planes
= num_planes
;
366 vb
->v4l2_buf
.index
= q
->num_buffers
+ buffer
;
367 vb
->v4l2_buf
.type
= q
->type
;
368 vb
->v4l2_buf
.memory
= memory
;
370 /* Allocate video buffer memory for the MMAP type */
371 if (memory
== V4L2_MEMORY_MMAP
) {
372 ret
= __vb2_buf_mem_alloc(vb
);
374 dprintk(1, "failed allocating memory for "
375 "buffer %d\n", buffer
);
380 * Call the driver-provided buffer initialization
381 * callback, if given. An error in initialization
382 * results in queue setup failure.
384 ret
= call_vb_qop(vb
, buf_init
, vb
);
386 dprintk(1, "buffer %d %p initialization"
387 " failed\n", buffer
, vb
);
388 __vb2_buf_mem_free(vb
);
394 q
->bufs
[q
->num_buffers
+ buffer
] = vb
;
397 __setup_lengths(q
, buffer
);
398 if (memory
== V4L2_MEMORY_MMAP
)
399 __setup_offsets(q
, buffer
);
401 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
408 * __vb2_free_mem() - release all video buffer memory for a given queue
410 static void __vb2_free_mem(struct vb2_queue
*q
, unsigned int buffers
)
413 struct vb2_buffer
*vb
;
415 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
417 vb
= q
->bufs
[buffer
];
421 /* Free MMAP buffers or release USERPTR buffers */
422 if (q
->memory
== V4L2_MEMORY_MMAP
)
423 __vb2_buf_mem_free(vb
);
424 else if (q
->memory
== V4L2_MEMORY_DMABUF
)
425 __vb2_buf_dmabuf_put(vb
);
427 __vb2_buf_userptr_put(vb
);
432 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
433 * related information, if no buffers are left return the queue to an
434 * uninitialized state. Might be called even if the queue has already been freed.
436 static int __vb2_queue_free(struct vb2_queue
*q
, unsigned int buffers
)
441 * Sanity check: when preparing a buffer the queue lock is released for
442 * a short while (see __buf_prepare for the details), which would allow
443 * a race with a reqbufs which can call this function. Removing the
444 * buffers from underneath __buf_prepare is obviously a bad idea, so we
445 * check if any of the buffers is in the state PREPARING, and if so we
446 * just return -EAGAIN.
448 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
450 if (q
->bufs
[buffer
] == NULL
)
452 if (q
->bufs
[buffer
]->state
== VB2_BUF_STATE_PREPARING
) {
453 dprintk(1, "preparing buffers, cannot free\n");
458 /* Call driver-provided cleanup function for each buffer, if provided */
459 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
461 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
463 if (vb
&& vb
->planes
[0].mem_priv
)
464 call_void_vb_qop(vb
, buf_cleanup
, vb
);
467 /* Release video buffer memory */
468 __vb2_free_mem(q
, buffers
);
470 #ifdef CONFIG_VIDEO_ADV_DEBUG
472 * Check that all the calls were balances during the life-time of this
473 * queue. If not (or if the debug level is 1 or up), then dump the
474 * counters to the kernel log.
476 if (q
->num_buffers
) {
477 bool unbalanced
= q
->cnt_start_streaming
!= q
->cnt_stop_streaming
||
478 q
->cnt_wait_prepare
!= q
->cnt_wait_finish
;
480 if (unbalanced
|| debug
) {
481 pr_info("vb2: counters for queue %p:%s\n", q
,
482 unbalanced
? " UNBALANCED!" : "");
483 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
484 q
->cnt_queue_setup
, q
->cnt_start_streaming
,
485 q
->cnt_stop_streaming
);
486 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
487 q
->cnt_wait_prepare
, q
->cnt_wait_finish
);
489 q
->cnt_queue_setup
= 0;
490 q
->cnt_wait_prepare
= 0;
491 q
->cnt_wait_finish
= 0;
492 q
->cnt_start_streaming
= 0;
493 q
->cnt_stop_streaming
= 0;
495 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
496 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
497 bool unbalanced
= vb
->cnt_mem_alloc
!= vb
->cnt_mem_put
||
498 vb
->cnt_mem_prepare
!= vb
->cnt_mem_finish
||
499 vb
->cnt_mem_get_userptr
!= vb
->cnt_mem_put_userptr
||
500 vb
->cnt_mem_attach_dmabuf
!= vb
->cnt_mem_detach_dmabuf
||
501 vb
->cnt_mem_map_dmabuf
!= vb
->cnt_mem_unmap_dmabuf
||
502 vb
->cnt_buf_queue
!= vb
->cnt_buf_done
||
503 vb
->cnt_buf_prepare
!= vb
->cnt_buf_finish
||
504 vb
->cnt_buf_init
!= vb
->cnt_buf_cleanup
;
506 if (unbalanced
|| debug
) {
507 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
508 q
, buffer
, unbalanced
? " UNBALANCED!" : "");
509 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
510 vb
->cnt_buf_init
, vb
->cnt_buf_cleanup
,
511 vb
->cnt_buf_prepare
, vb
->cnt_buf_finish
);
512 pr_info("vb2: buf_queue: %u buf_done: %u\n",
513 vb
->cnt_buf_queue
, vb
->cnt_buf_done
);
514 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
515 vb
->cnt_mem_alloc
, vb
->cnt_mem_put
,
516 vb
->cnt_mem_prepare
, vb
->cnt_mem_finish
,
518 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
519 vb
->cnt_mem_get_userptr
, vb
->cnt_mem_put_userptr
);
520 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
521 vb
->cnt_mem_attach_dmabuf
, vb
->cnt_mem_detach_dmabuf
,
522 vb
->cnt_mem_map_dmabuf
, vb
->cnt_mem_unmap_dmabuf
);
523 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
524 vb
->cnt_mem_get_dmabuf
,
525 vb
->cnt_mem_num_users
,
532 /* Free videobuf buffers */
533 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
535 kfree(q
->bufs
[buffer
]);
536 q
->bufs
[buffer
] = NULL
;
539 q
->num_buffers
-= buffers
;
540 if (!q
->num_buffers
) {
542 INIT_LIST_HEAD(&q
->queued_list
);
548 * __verify_planes_array() - verify that the planes array passed in struct
549 * v4l2_buffer from userspace can be safely used
551 static int __verify_planes_array(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
553 if (!V4L2_TYPE_IS_MULTIPLANAR(b
->type
))
556 /* Is memory for copying plane information present? */
557 if (NULL
== b
->m
.planes
) {
558 dprintk(1, "multi-planar buffer passed but "
559 "planes array not provided\n");
563 if (b
->length
< vb
->num_planes
|| b
->length
> VIDEO_MAX_PLANES
) {
564 dprintk(1, "incorrect planes array length, "
565 "expected %d, got %d\n", vb
->num_planes
, b
->length
);
573 * __verify_length() - Verify that the bytesused value for each plane fits in
574 * the plane length and that the data offset doesn't exceed the bytesused value.
576 static int __verify_length(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
581 if (!V4L2_TYPE_IS_OUTPUT(b
->type
))
584 if (V4L2_TYPE_IS_MULTIPLANAR(b
->type
)) {
585 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
586 length
= (b
->memory
== V4L2_MEMORY_USERPTR
)
587 ? b
->m
.planes
[plane
].length
588 : vb
->v4l2_planes
[plane
].length
;
590 if (b
->m
.planes
[plane
].bytesused
> length
)
593 if (b
->m
.planes
[plane
].data_offset
> 0 &&
594 b
->m
.planes
[plane
].data_offset
>=
595 b
->m
.planes
[plane
].bytesused
)
599 length
= (b
->memory
== V4L2_MEMORY_USERPTR
)
600 ? b
->length
: vb
->v4l2_planes
[0].length
;
602 if (b
->bytesused
> length
)
610 * __buffer_in_use() - return true if the buffer is in use and
611 * the queue cannot be freed (by the means of REQBUFS(0)) call
613 static bool __buffer_in_use(struct vb2_queue
*q
, struct vb2_buffer
*vb
)
616 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
617 void *mem_priv
= vb
->planes
[plane
].mem_priv
;
619 * If num_users() has not been provided, call_memop
620 * will return 0, apparently nobody cares about this
621 * case anyway. If num_users() returns more than 1,
622 * we are not the only user of the plane's memory.
624 if (mem_priv
&& call_memop(vb
, num_users
, mem_priv
) > 1)
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 (__buffer_in_use(q
, q
->bufs
[buffer
]))
645 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
646 * returned to userspace
648 static void __fill_v4l2_buffer(struct vb2_buffer
*vb
, struct v4l2_buffer
*b
)
650 struct vb2_queue
*q
= vb
->vb2_queue
;
652 /* Copy back data such as timestamp, flags, etc. */
653 memcpy(b
, &vb
->v4l2_buf
, offsetof(struct v4l2_buffer
, m
));
654 b
->reserved2
= vb
->v4l2_buf
.reserved2
;
655 b
->reserved
= vb
->v4l2_buf
.reserved
;
657 if (V4L2_TYPE_IS_MULTIPLANAR(q
->type
)) {
659 * Fill in plane-related data if userspace provided an array
660 * for it. The caller has already verified memory and size.
662 b
->length
= vb
->num_planes
;
663 memcpy(b
->m
.planes
, vb
->v4l2_planes
,
664 b
->length
* sizeof(struct v4l2_plane
));
667 * We use length and offset in v4l2_planes array even for
668 * single-planar buffers, but userspace does not.
670 b
->length
= vb
->v4l2_planes
[0].length
;
671 b
->bytesused
= vb
->v4l2_planes
[0].bytesused
;
672 if (q
->memory
== V4L2_MEMORY_MMAP
)
673 b
->m
.offset
= vb
->v4l2_planes
[0].m
.mem_offset
;
674 else if (q
->memory
== V4L2_MEMORY_USERPTR
)
675 b
->m
.userptr
= vb
->v4l2_planes
[0].m
.userptr
;
676 else if (q
->memory
== V4L2_MEMORY_DMABUF
)
677 b
->m
.fd
= vb
->v4l2_planes
[0].m
.fd
;
681 * Clear any buffer state related flags.
683 b
->flags
&= ~V4L2_BUFFER_MASK_FLAGS
;
684 b
->flags
|= q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
;
685 if ((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) !=
686 V4L2_BUF_FLAG_TIMESTAMP_COPY
) {
688 * For non-COPY timestamps, drop timestamp source bits
689 * and obtain the timestamp source from the queue.
691 b
->flags
&= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
692 b
->flags
|= q
->timestamp_flags
& V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
696 case VB2_BUF_STATE_QUEUED
:
697 case VB2_BUF_STATE_ACTIVE
:
698 b
->flags
|= V4L2_BUF_FLAG_QUEUED
;
700 case VB2_BUF_STATE_ERROR
:
701 b
->flags
|= V4L2_BUF_FLAG_ERROR
;
703 case VB2_BUF_STATE_DONE
:
704 b
->flags
|= V4L2_BUF_FLAG_DONE
;
706 case VB2_BUF_STATE_PREPARED
:
707 b
->flags
|= V4L2_BUF_FLAG_PREPARED
;
709 case VB2_BUF_STATE_PREPARING
:
710 case VB2_BUF_STATE_DEQUEUED
:
715 if (__buffer_in_use(q
, vb
))
716 b
->flags
|= V4L2_BUF_FLAG_MAPPED
;
720 * vb2_querybuf() - query video buffer information
722 * @b: buffer struct passed from userspace to vidioc_querybuf handler
725 * Should be called from vidioc_querybuf ioctl handler in driver.
726 * This function will verify the passed v4l2_buffer structure and fill the
727 * relevant information for the userspace.
729 * The return values from this function are intended to be directly returned
730 * from vidioc_querybuf handler in driver.
732 int vb2_querybuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
734 struct vb2_buffer
*vb
;
737 if (b
->type
!= q
->type
) {
738 dprintk(1, "wrong buffer type\n");
742 if (b
->index
>= q
->num_buffers
) {
743 dprintk(1, "buffer index out of range\n");
746 vb
= q
->bufs
[b
->index
];
747 ret
= __verify_planes_array(vb
, b
);
749 __fill_v4l2_buffer(vb
, b
);
752 EXPORT_SYMBOL(vb2_querybuf
);
755 * __verify_userptr_ops() - verify that all memory operations required for
756 * USERPTR queue type have been provided
758 static int __verify_userptr_ops(struct vb2_queue
*q
)
760 if (!(q
->io_modes
& VB2_USERPTR
) || !q
->mem_ops
->get_userptr
||
761 !q
->mem_ops
->put_userptr
)
768 * __verify_mmap_ops() - verify that all memory operations required for
769 * MMAP queue type have been provided
771 static int __verify_mmap_ops(struct vb2_queue
*q
)
773 if (!(q
->io_modes
& VB2_MMAP
) || !q
->mem_ops
->alloc
||
774 !q
->mem_ops
->put
|| !q
->mem_ops
->mmap
)
781 * __verify_dmabuf_ops() - verify that all memory operations required for
782 * DMABUF queue type have been provided
784 static int __verify_dmabuf_ops(struct vb2_queue
*q
)
786 if (!(q
->io_modes
& VB2_DMABUF
) || !q
->mem_ops
->attach_dmabuf
||
787 !q
->mem_ops
->detach_dmabuf
|| !q
->mem_ops
->map_dmabuf
||
788 !q
->mem_ops
->unmap_dmabuf
)
795 * __verify_memory_type() - Check whether the memory type and buffer type
796 * passed to a buffer operation are compatible with the queue.
798 static int __verify_memory_type(struct vb2_queue
*q
,
799 enum v4l2_memory memory
, enum v4l2_buf_type type
)
801 if (memory
!= V4L2_MEMORY_MMAP
&& memory
!= V4L2_MEMORY_USERPTR
&&
802 memory
!= V4L2_MEMORY_DMABUF
) {
803 dprintk(1, "unsupported memory type\n");
807 if (type
!= q
->type
) {
808 dprintk(1, "requested type is incorrect\n");
813 * Make sure all the required memory ops for given memory type
816 if (memory
== V4L2_MEMORY_MMAP
&& __verify_mmap_ops(q
)) {
817 dprintk(1, "MMAP for current setup unsupported\n");
821 if (memory
== V4L2_MEMORY_USERPTR
&& __verify_userptr_ops(q
)) {
822 dprintk(1, "USERPTR for current setup unsupported\n");
826 if (memory
== V4L2_MEMORY_DMABUF
&& __verify_dmabuf_ops(q
)) {
827 dprintk(1, "DMABUF for current setup unsupported\n");
832 * Place the busy tests at the end: -EBUSY can be ignored when
833 * create_bufs is called with count == 0, but count == 0 should still
834 * do the memory and type validation.
836 if (vb2_fileio_is_active(q
)) {
837 dprintk(1, "file io in progress\n");
844 * __reqbufs() - Initiate streaming
845 * @q: videobuf2 queue
846 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
848 * Should be called from vidioc_reqbufs ioctl handler of a driver.
850 * 1) verifies streaming parameters passed from the userspace,
851 * 2) sets up the queue,
852 * 3) negotiates number of buffers and planes per buffer with the driver
853 * to be used during streaming,
854 * 4) allocates internal buffer structures (struct vb2_buffer), according to
855 * the agreed parameters,
856 * 5) for MMAP memory type, allocates actual video memory, using the
857 * memory handling/allocation routines provided during queue initialization
859 * If req->count is 0, all the memory will be freed instead.
860 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
861 * and the queue is not busy, memory will be reallocated.
863 * The return values from this function are intended to be directly returned
864 * from vidioc_reqbufs handler in driver.
866 static int __reqbufs(struct vb2_queue
*q
, struct v4l2_requestbuffers
*req
)
868 unsigned int num_buffers
, allocated_buffers
, num_planes
= 0;
872 dprintk(1, "streaming active\n");
876 if (req
->count
== 0 || q
->num_buffers
!= 0 || q
->memory
!= req
->memory
) {
878 * We already have buffers allocated, so first check if they
879 * are not in use and can be freed.
881 if (q
->memory
== V4L2_MEMORY_MMAP
&& __buffers_in_use(q
)) {
882 dprintk(1, "memory in use, cannot free\n");
887 * Call queue_cancel to clean up any buffers in the PREPARED or
888 * QUEUED state which is possible if buffers were prepared or
889 * queued without ever calling STREAMON.
891 __vb2_queue_cancel(q
);
892 ret
= __vb2_queue_free(q
, q
->num_buffers
);
897 * In case of REQBUFS(0) return immediately without calling
898 * driver's queue_setup() callback and allocating resources.
905 * Make sure the requested values and current defaults are sane.
907 num_buffers
= min_t(unsigned int, req
->count
, VIDEO_MAX_FRAME
);
908 num_buffers
= max_t(unsigned int, num_buffers
, q
->min_buffers_needed
);
909 memset(q
->plane_sizes
, 0, sizeof(q
->plane_sizes
));
910 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
911 q
->memory
= req
->memory
;
914 * Ask the driver how many buffers and planes per buffer it requires.
915 * Driver also sets the size and allocator context for each plane.
917 ret
= call_qop(q
, queue_setup
, q
, NULL
, &num_buffers
, &num_planes
,
918 q
->plane_sizes
, q
->alloc_ctx
);
922 /* Finally, allocate buffers and video memory */
923 allocated_buffers
= __vb2_queue_alloc(q
, req
->memory
, num_buffers
, num_planes
);
924 if (allocated_buffers
== 0) {
925 dprintk(1, "memory allocation failed\n");
930 * There is no point in continuing if we can't allocate the minimum
931 * number of buffers needed by this vb2_queue.
933 if (allocated_buffers
< q
->min_buffers_needed
)
937 * Check if driver can handle the allocated number of buffers.
939 if (!ret
&& allocated_buffers
< num_buffers
) {
940 num_buffers
= allocated_buffers
;
942 ret
= call_qop(q
, queue_setup
, q
, NULL
, &num_buffers
,
943 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
945 if (!ret
&& allocated_buffers
< num_buffers
)
949 * Either the driver has accepted a smaller number of buffers,
950 * or .queue_setup() returned an error
954 q
->num_buffers
= allocated_buffers
;
958 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
959 * from q->num_buffers.
961 __vb2_queue_free(q
, allocated_buffers
);
966 * Return the number of successfully allocated buffers
969 req
->count
= allocated_buffers
;
975 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
977 * @q: videobuf2 queue
978 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
980 int vb2_reqbufs(struct vb2_queue
*q
, struct v4l2_requestbuffers
*req
)
982 int ret
= __verify_memory_type(q
, req
->memory
, req
->type
);
984 return ret
? ret
: __reqbufs(q
, req
);
986 EXPORT_SYMBOL_GPL(vb2_reqbufs
);
989 * __create_bufs() - Allocate buffers and any required auxiliary structs
990 * @q: videobuf2 queue
991 * @create: creation parameters, passed from userspace to vidioc_create_bufs
994 * Should be called from vidioc_create_bufs ioctl handler of a driver.
996 * 1) verifies parameter sanity
997 * 2) calls the .queue_setup() queue operation
998 * 3) performs any necessary memory allocations
1000 * The return values from this function are intended to be directly returned
1001 * from vidioc_create_bufs handler in driver.
1003 static int __create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
1005 unsigned int num_planes
= 0, num_buffers
, allocated_buffers
;
1008 if (q
->num_buffers
== VIDEO_MAX_FRAME
) {
1009 dprintk(1, "maximum number of buffers already allocated\n");
1013 if (!q
->num_buffers
) {
1014 memset(q
->plane_sizes
, 0, sizeof(q
->plane_sizes
));
1015 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
1016 q
->memory
= create
->memory
;
1019 num_buffers
= min(create
->count
, VIDEO_MAX_FRAME
- q
->num_buffers
);
1022 * Ask the driver, whether the requested number of buffers, planes per
1023 * buffer and their sizes are acceptable
1025 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
1026 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
1030 /* Finally, allocate buffers and video memory */
1031 allocated_buffers
= __vb2_queue_alloc(q
, create
->memory
, num_buffers
,
1033 if (allocated_buffers
== 0) {
1034 dprintk(1, "memory allocation failed\n");
1039 * Check if driver can handle the so far allocated number of buffers.
1041 if (allocated_buffers
< num_buffers
) {
1042 num_buffers
= allocated_buffers
;
1045 * q->num_buffers contains the total number of buffers, that the
1046 * queue driver has set up
1048 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
1049 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
1051 if (!ret
&& allocated_buffers
< num_buffers
)
1055 * Either the driver has accepted a smaller number of buffers,
1056 * or .queue_setup() returned an error
1060 q
->num_buffers
+= allocated_buffers
;
1064 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1065 * from q->num_buffers.
1067 __vb2_queue_free(q
, allocated_buffers
);
1072 * Return the number of successfully allocated buffers
1075 create
->count
= allocated_buffers
;
1081 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1082 * memory and type values.
1083 * @q: videobuf2 queue
1084 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1087 int vb2_create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
1089 int ret
= __verify_memory_type(q
, create
->memory
, create
->format
.type
);
1091 create
->index
= q
->num_buffers
;
1092 if (create
->count
== 0)
1093 return ret
!= -EBUSY
? ret
: 0;
1094 return ret
? ret
: __create_bufs(q
, create
);
1096 EXPORT_SYMBOL_GPL(vb2_create_bufs
);
1099 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1100 * @vb: vb2_buffer to which the plane in question belongs to
1101 * @plane_no: plane number for which the address is to be returned
1103 * This function returns a kernel virtual address of a given plane if
1104 * such a mapping exist, NULL otherwise.
1106 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
)
1108 if (plane_no
> vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
1111 return call_ptr_memop(vb
, vaddr
, vb
->planes
[plane_no
].mem_priv
);
1114 EXPORT_SYMBOL_GPL(vb2_plane_vaddr
);
1117 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1118 * @vb: vb2_buffer to which the plane in question belongs to
1119 * @plane_no: plane number for which the cookie is to be returned
1121 * This function returns an allocator specific cookie for a given plane if
1122 * available, NULL otherwise. The allocator should provide some simple static
1123 * inline function, which would convert this cookie to the allocator specific
1124 * type that can be used directly by the driver to access the buffer. This can
1125 * be for example physical address, pointer to scatter list or IOMMU mapping.
1127 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
)
1129 if (plane_no
> vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
1132 return call_ptr_memop(vb
, cookie
, vb
->planes
[plane_no
].mem_priv
);
1134 EXPORT_SYMBOL_GPL(vb2_plane_cookie
);
1137 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1138 * @vb: vb2_buffer returned from the driver
1139 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
1140 * or VB2_BUF_STATE_ERROR if the operation finished with an error.
1141 * If start_streaming fails then it should return buffers with state
1142 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1144 * This function should be called by the driver after a hardware operation on
1145 * a buffer is finished and the buffer may be returned to userspace. The driver
1146 * cannot use this buffer anymore until it is queued back to it by videobuf
1147 * by the means of buf_queue callback. Only buffers previously queued to the
1148 * driver by buf_queue can be passed to this function.
1150 * While streaming a buffer can only be returned in state DONE or ERROR.
1151 * The start_streaming op can also return them in case the DMA engine cannot
1152 * be started for some reason. In that case the buffers should be returned with
1155 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
)
1157 struct vb2_queue
*q
= vb
->vb2_queue
;
1158 unsigned long flags
;
1161 if (WARN_ON(vb
->state
!= VB2_BUF_STATE_ACTIVE
))
1164 if (!q
->start_streaming_called
) {
1165 if (WARN_ON(state
!= VB2_BUF_STATE_QUEUED
))
1166 state
= VB2_BUF_STATE_QUEUED
;
1167 } else if (WARN_ON(state
!= VB2_BUF_STATE_DONE
&&
1168 state
!= VB2_BUF_STATE_ERROR
)) {
1169 state
= VB2_BUF_STATE_ERROR
;
1172 #ifdef CONFIG_VIDEO_ADV_DEBUG
1174 * Although this is not a callback, it still does have to balance
1175 * with the buf_queue op. So update this counter manually.
1179 dprintk(4, "done processing on buffer %d, state: %d\n",
1180 vb
->v4l2_buf
.index
, state
);
1183 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1184 call_void_memop(vb
, finish
, vb
->planes
[plane
].mem_priv
);
1186 /* Add the buffer to the done buffers list */
1187 spin_lock_irqsave(&q
->done_lock
, flags
);
1189 if (state
!= VB2_BUF_STATE_QUEUED
)
1190 list_add_tail(&vb
->done_entry
, &q
->done_list
);
1191 atomic_dec(&q
->owned_by_drv_count
);
1192 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1194 if (state
== VB2_BUF_STATE_QUEUED
)
1197 /* Inform any processes that may be waiting for buffers */
1198 wake_up(&q
->done_wq
);
1200 EXPORT_SYMBOL_GPL(vb2_buffer_done
);
1203 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1204 * v4l2_buffer by the userspace. The caller has already verified that struct
1205 * v4l2_buffer has a valid number of planes.
1207 static void __fill_vb2_buffer(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
,
1208 struct v4l2_plane
*v4l2_planes
)
1212 if (V4L2_TYPE_IS_MULTIPLANAR(b
->type
)) {
1213 /* Fill in driver-provided information for OUTPUT types */
1214 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1215 bool bytesused_is_used
;
1217 /* Check if bytesused == 0 for all planes */
1218 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1219 if (b
->m
.planes
[plane
].bytesused
)
1221 bytesused_is_used
= plane
< vb
->num_planes
;
1224 * Will have to go up to b->length when API starts
1225 * accepting variable number of planes.
1227 * If bytesused_is_used is false, then fall back to the
1228 * full buffer size. In that case userspace clearly
1229 * never bothered to set it and it's a safe assumption
1230 * that they really meant to use the full plane sizes.
1232 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1233 struct v4l2_plane
*pdst
= &v4l2_planes
[plane
];
1234 struct v4l2_plane
*psrc
= &b
->m
.planes
[plane
];
1236 pdst
->bytesused
= bytesused_is_used
?
1237 psrc
->bytesused
: psrc
->length
;
1238 pdst
->data_offset
= psrc
->data_offset
;
1242 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
1243 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1244 v4l2_planes
[plane
].m
.userptr
=
1245 b
->m
.planes
[plane
].m
.userptr
;
1246 v4l2_planes
[plane
].length
=
1247 b
->m
.planes
[plane
].length
;
1250 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
1251 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1252 v4l2_planes
[plane
].m
.fd
=
1253 b
->m
.planes
[plane
].m
.fd
;
1254 v4l2_planes
[plane
].length
=
1255 b
->m
.planes
[plane
].length
;
1260 * Single-planar buffers do not use planes array,
1261 * so fill in relevant v4l2_buffer struct fields instead.
1262 * In videobuf we use our internal V4l2_planes struct for
1263 * single-planar buffers as well, for simplicity.
1265 * If bytesused == 0, then fall back to the full buffer size
1266 * as that's a sensible default.
1268 if (V4L2_TYPE_IS_OUTPUT(b
->type
))
1269 v4l2_planes
[0].bytesused
=
1270 b
->bytesused
? b
->bytesused
: b
->length
;
1272 v4l2_planes
[0].bytesused
= 0;
1274 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
1275 v4l2_planes
[0].m
.userptr
= b
->m
.userptr
;
1276 v4l2_planes
[0].length
= b
->length
;
1279 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
1280 v4l2_planes
[0].m
.fd
= b
->m
.fd
;
1281 v4l2_planes
[0].length
= b
->length
;
1285 /* Zero flags that the vb2 core handles */
1286 vb
->v4l2_buf
.flags
= b
->flags
& ~V4L2_BUFFER_MASK_FLAGS
;
1287 if ((vb
->vb2_queue
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) !=
1288 V4L2_BUF_FLAG_TIMESTAMP_COPY
|| !V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1290 * Non-COPY timestamps and non-OUTPUT queues will get
1291 * their timestamp and timestamp source flags from the
1294 vb
->v4l2_buf
.flags
&= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
1297 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1299 * For output buffers mask out the timecode flag:
1300 * this will be handled later in vb2_internal_qbuf().
1301 * The 'field' is valid metadata for this output buffer
1302 * and so that needs to be copied here.
1304 vb
->v4l2_buf
.flags
&= ~V4L2_BUF_FLAG_TIMECODE
;
1305 vb
->v4l2_buf
.field
= b
->field
;
1307 /* Zero any output buffer flags as this is a capture buffer */
1308 vb
->v4l2_buf
.flags
&= ~V4L2_BUFFER_OUT_FLAGS
;
1313 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1315 static int __qbuf_mmap(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1317 __fill_vb2_buffer(vb
, b
, vb
->v4l2_planes
);
1318 return call_vb_qop(vb
, buf_prepare
, vb
);
1322 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1324 static int __qbuf_userptr(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1326 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1327 struct vb2_queue
*q
= vb
->vb2_queue
;
1331 int write
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
1332 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1334 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1335 /* Copy relevant information provided by the userspace */
1336 __fill_vb2_buffer(vb
, b
, planes
);
1338 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1339 /* Skip the plane if already verified */
1340 if (vb
->v4l2_planes
[plane
].m
.userptr
&&
1341 vb
->v4l2_planes
[plane
].m
.userptr
== planes
[plane
].m
.userptr
1342 && vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
)
1345 dprintk(3, "userspace address for plane %d changed, "
1346 "reacquiring memory\n", plane
);
1348 /* Check if the provided plane buffer is large enough */
1349 if (planes
[plane
].length
< q
->plane_sizes
[plane
]) {
1350 dprintk(1, "provided buffer size %u is less than "
1351 "setup size %u for plane %d\n",
1352 planes
[plane
].length
,
1353 q
->plane_sizes
[plane
], plane
);
1358 /* Release previously acquired memory if present */
1359 if (vb
->planes
[plane
].mem_priv
) {
1362 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1364 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1367 vb
->planes
[plane
].mem_priv
= NULL
;
1368 memset(&vb
->v4l2_planes
[plane
], 0, sizeof(struct v4l2_plane
));
1370 /* Acquire each plane's memory */
1371 mem_priv
= call_ptr_memop(vb
, get_userptr
, q
->alloc_ctx
[plane
],
1372 planes
[plane
].m
.userptr
,
1373 planes
[plane
].length
, write
);
1374 if (IS_ERR_OR_NULL(mem_priv
)) {
1375 dprintk(1, "failed acquiring userspace "
1376 "memory for plane %d\n", plane
);
1377 ret
= mem_priv
? PTR_ERR(mem_priv
) : -EINVAL
;
1380 vb
->planes
[plane
].mem_priv
= mem_priv
;
1384 * Now that everything is in order, copy relevant information
1385 * provided by userspace.
1387 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1388 vb
->v4l2_planes
[plane
] = planes
[plane
];
1392 * One or more planes changed, so we must call buf_init to do
1393 * the driver-specific initialization on the newly acquired
1394 * buffer, if provided.
1396 ret
= call_vb_qop(vb
, buf_init
, vb
);
1398 dprintk(1, "buffer initialization failed\n");
1403 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1405 dprintk(1, "buffer preparation failed\n");
1406 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1412 /* In case of errors, release planes that were already acquired */
1413 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1414 if (vb
->planes
[plane
].mem_priv
)
1415 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1416 vb
->planes
[plane
].mem_priv
= NULL
;
1417 vb
->v4l2_planes
[plane
].m
.userptr
= 0;
1418 vb
->v4l2_planes
[plane
].length
= 0;
1425 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1427 static int __qbuf_dmabuf(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1429 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1430 struct vb2_queue
*q
= vb
->vb2_queue
;
1434 int write
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
1435 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1437 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1438 /* Copy relevant information provided by the userspace */
1439 __fill_vb2_buffer(vb
, b
, planes
);
1441 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1442 struct dma_buf
*dbuf
= dma_buf_get(planes
[plane
].m
.fd
);
1444 if (IS_ERR_OR_NULL(dbuf
)) {
1445 dprintk(1, "invalid dmabuf fd for plane %d\n",
1451 /* use DMABUF size if length is not provided */
1452 if (planes
[plane
].length
== 0)
1453 planes
[plane
].length
= dbuf
->size
;
1455 if (planes
[plane
].length
< q
->plane_sizes
[plane
]) {
1456 dprintk(1, "invalid dmabuf length for plane %d\n",
1462 /* Skip the plane if already verified */
1463 if (dbuf
== vb
->planes
[plane
].dbuf
&&
1464 vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
) {
1469 dprintk(1, "buffer for plane %d changed\n", plane
);
1473 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1476 /* Release previously acquired memory if present */
1477 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
1478 memset(&vb
->v4l2_planes
[plane
], 0, sizeof(struct v4l2_plane
));
1480 /* Acquire each plane's memory */
1481 mem_priv
= call_ptr_memop(vb
, attach_dmabuf
, q
->alloc_ctx
[plane
],
1482 dbuf
, planes
[plane
].length
, write
);
1483 if (IS_ERR(mem_priv
)) {
1484 dprintk(1, "failed to attach dmabuf\n");
1485 ret
= PTR_ERR(mem_priv
);
1490 vb
->planes
[plane
].dbuf
= dbuf
;
1491 vb
->planes
[plane
].mem_priv
= mem_priv
;
1494 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1495 * really we want to do this just before the DMA, not while queueing
1498 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1499 ret
= call_memop(vb
, map_dmabuf
, vb
->planes
[plane
].mem_priv
);
1501 dprintk(1, "failed to map dmabuf for plane %d\n",
1505 vb
->planes
[plane
].dbuf_mapped
= 1;
1509 * Now that everything is in order, copy relevant information
1510 * provided by userspace.
1512 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1513 vb
->v4l2_planes
[plane
] = planes
[plane
];
1517 * Call driver-specific initialization on the newly acquired buffer,
1520 ret
= call_vb_qop(vb
, buf_init
, vb
);
1522 dprintk(1, "buffer initialization failed\n");
1527 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1529 dprintk(1, "buffer preparation failed\n");
1530 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1536 /* In case of errors, release planes that were already acquired */
1537 __vb2_buf_dmabuf_put(vb
);
1543 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1545 static void __enqueue_in_driver(struct vb2_buffer
*vb
)
1547 struct vb2_queue
*q
= vb
->vb2_queue
;
1550 vb
->state
= VB2_BUF_STATE_ACTIVE
;
1551 atomic_inc(&q
->owned_by_drv_count
);
1554 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1555 call_void_memop(vb
, prepare
, vb
->planes
[plane
].mem_priv
);
1557 call_void_vb_qop(vb
, buf_queue
, vb
);
1560 static int __buf_prepare(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1562 struct vb2_queue
*q
= vb
->vb2_queue
;
1563 struct rw_semaphore
*mmap_sem
;
1566 ret
= __verify_length(vb
, b
);
1568 dprintk(1, "plane parameters verification failed: %d\n", ret
);
1571 if (b
->field
== V4L2_FIELD_ALTERNATE
&& V4L2_TYPE_IS_OUTPUT(q
->type
)) {
1573 * If the format's field is ALTERNATE, then the buffer's field
1574 * should be either TOP or BOTTOM, not ALTERNATE since that
1575 * makes no sense. The driver has to know whether the
1576 * buffer represents a top or a bottom field in order to
1577 * program any DMA correctly. Using ALTERNATE is wrong, since
1578 * that just says that it is either a top or a bottom field,
1579 * but not which of the two it is.
1581 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1585 vb
->state
= VB2_BUF_STATE_PREPARING
;
1586 vb
->v4l2_buf
.timestamp
.tv_sec
= 0;
1587 vb
->v4l2_buf
.timestamp
.tv_usec
= 0;
1588 vb
->v4l2_buf
.sequence
= 0;
1590 switch (q
->memory
) {
1591 case V4L2_MEMORY_MMAP
:
1592 ret
= __qbuf_mmap(vb
, b
);
1594 case V4L2_MEMORY_USERPTR
:
1596 * In case of user pointer buffers vb2 allocators need to get
1597 * direct access to userspace pages. This requires getting
1598 * the mmap semaphore for read access in the current process
1599 * structure. The same semaphore is taken before calling mmap
1600 * operation, while both qbuf/prepare_buf and mmap are called
1601 * by the driver or v4l2 core with the driver's lock held.
1602 * To avoid an AB-BA deadlock (mmap_sem then driver's lock in
1603 * mmap and driver's lock then mmap_sem in qbuf/prepare_buf),
1604 * the videobuf2 core releases the driver's lock, takes
1605 * mmap_sem and then takes the driver's lock again.
1607 mmap_sem
= ¤t
->mm
->mmap_sem
;
1608 call_void_qop(q
, wait_prepare
, q
);
1609 down_read(mmap_sem
);
1610 call_void_qop(q
, wait_finish
, q
);
1612 ret
= __qbuf_userptr(vb
, b
);
1616 case V4L2_MEMORY_DMABUF
:
1617 ret
= __qbuf_dmabuf(vb
, b
);
1620 WARN(1, "Invalid queue type\n");
1625 dprintk(1, "buffer preparation failed: %d\n", ret
);
1626 vb
->state
= ret
? VB2_BUF_STATE_DEQUEUED
: VB2_BUF_STATE_PREPARED
;
1631 static int vb2_queue_or_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
,
1634 if (b
->type
!= q
->type
) {
1635 dprintk(1, "%s: invalid buffer type\n", opname
);
1639 if (b
->index
>= q
->num_buffers
) {
1640 dprintk(1, "%s: buffer index out of range\n", opname
);
1644 if (q
->bufs
[b
->index
] == NULL
) {
1645 /* Should never happen */
1646 dprintk(1, "%s: buffer is NULL\n", opname
);
1650 if (b
->memory
!= q
->memory
) {
1651 dprintk(1, "%s: invalid memory type\n", opname
);
1655 return __verify_planes_array(q
->bufs
[b
->index
], b
);
1659 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1660 * @q: videobuf2 queue
1661 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1664 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1666 * 1) verifies the passed buffer,
1667 * 2) calls buf_prepare callback in the driver (if provided), in which
1668 * driver-specific buffer initialization can be performed,
1670 * The return values from this function are intended to be directly returned
1671 * from vidioc_prepare_buf handler in driver.
1673 int vb2_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1675 struct vb2_buffer
*vb
;
1678 if (vb2_fileio_is_active(q
)) {
1679 dprintk(1, "file io in progress\n");
1683 ret
= vb2_queue_or_prepare_buf(q
, b
, "prepare_buf");
1687 vb
= q
->bufs
[b
->index
];
1688 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1689 dprintk(1, "invalid buffer state %d\n",
1694 ret
= __buf_prepare(vb
, b
);
1696 /* Fill buffer information for the userspace */
1697 __fill_v4l2_buffer(vb
, b
);
1699 dprintk(1, "prepare of buffer %d succeeded\n", vb
->v4l2_buf
.index
);
1703 EXPORT_SYMBOL_GPL(vb2_prepare_buf
);
1706 * vb2_start_streaming() - Attempt to start streaming.
1707 * @q: videobuf2 queue
1709 * Attempt to start streaming. When this function is called there must be
1710 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1711 * number of buffers required for the DMA engine to function). If the
1712 * @start_streaming op fails it is supposed to return all the driver-owned
1713 * buffers back to vb2 in state QUEUED. Check if that happened and if
1714 * not warn and reclaim them forcefully.
1716 static int vb2_start_streaming(struct vb2_queue
*q
)
1718 struct vb2_buffer
*vb
;
1722 * If any buffers were queued before streamon,
1723 * we can now pass them to driver for processing.
1725 list_for_each_entry(vb
, &q
->queued_list
, queued_entry
)
1726 __enqueue_in_driver(vb
);
1728 /* Tell the driver to start streaming */
1729 ret
= call_qop(q
, start_streaming
, q
,
1730 atomic_read(&q
->owned_by_drv_count
));
1731 q
->start_streaming_called
= ret
== 0;
1735 dprintk(1, "driver refused to start streaming\n");
1736 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1740 * Forcefully reclaim buffers if the driver did not
1741 * correctly return them to vb2.
1743 for (i
= 0; i
< q
->num_buffers
; ++i
) {
1745 if (vb
->state
== VB2_BUF_STATE_ACTIVE
)
1746 vb2_buffer_done(vb
, VB2_BUF_STATE_QUEUED
);
1748 /* Must be zero now */
1749 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1754 static int vb2_internal_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1756 int ret
= vb2_queue_or_prepare_buf(q
, b
, "qbuf");
1757 struct vb2_buffer
*vb
;
1762 vb
= q
->bufs
[b
->index
];
1764 switch (vb
->state
) {
1765 case VB2_BUF_STATE_DEQUEUED
:
1766 ret
= __buf_prepare(vb
, b
);
1770 case VB2_BUF_STATE_PREPARED
:
1772 case VB2_BUF_STATE_PREPARING
:
1773 dprintk(1, "buffer still being prepared\n");
1776 dprintk(1, "invalid buffer state %d\n", vb
->state
);
1781 * Add to the queued buffers list, a buffer will stay on it until
1782 * dequeued in dqbuf.
1784 list_add_tail(&vb
->queued_entry
, &q
->queued_list
);
1786 vb
->state
= VB2_BUF_STATE_QUEUED
;
1787 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
1789 * For output buffers copy the timestamp if needed,
1790 * and the timecode field and flag if needed.
1792 if ((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
1793 V4L2_BUF_FLAG_TIMESTAMP_COPY
)
1794 vb
->v4l2_buf
.timestamp
= b
->timestamp
;
1795 vb
->v4l2_buf
.flags
|= b
->flags
& V4L2_BUF_FLAG_TIMECODE
;
1796 if (b
->flags
& V4L2_BUF_FLAG_TIMECODE
)
1797 vb
->v4l2_buf
.timecode
= b
->timecode
;
1801 * If already streaming, give the buffer to driver for processing.
1802 * If not, the buffer will be given to driver on next streamon.
1804 if (q
->start_streaming_called
)
1805 __enqueue_in_driver(vb
);
1807 /* Fill buffer information for the userspace */
1808 __fill_v4l2_buffer(vb
, b
);
1811 * If streamon has been called, and we haven't yet called
1812 * start_streaming() since not enough buffers were queued, and
1813 * we now have reached the minimum number of queued buffers,
1814 * then we can finally call start_streaming().
1816 if (q
->streaming
&& !q
->start_streaming_called
&&
1817 q
->queued_count
>= q
->min_buffers_needed
) {
1818 ret
= vb2_start_streaming(q
);
1823 dprintk(1, "qbuf of buffer %d succeeded\n", vb
->v4l2_buf
.index
);
1828 * vb2_qbuf() - Queue a buffer from userspace
1829 * @q: videobuf2 queue
1830 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1833 * Should be called from vidioc_qbuf ioctl handler of a driver.
1835 * 1) verifies the passed buffer,
1836 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1837 * which driver-specific buffer initialization can be performed,
1838 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1839 * callback for processing.
1841 * The return values from this function are intended to be directly returned
1842 * from vidioc_qbuf handler in driver.
1844 int vb2_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1846 if (vb2_fileio_is_active(q
)) {
1847 dprintk(1, "file io in progress\n");
1851 return vb2_internal_qbuf(q
, b
);
1853 EXPORT_SYMBOL_GPL(vb2_qbuf
);
1856 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1859 * Will sleep if required for nonblocking == false.
1861 static int __vb2_wait_for_done_vb(struct vb2_queue
*q
, int nonblocking
)
1864 * All operations on vb_done_list are performed under done_lock
1865 * spinlock protection. However, buffers may be removed from
1866 * it and returned to userspace only while holding both driver's
1867 * lock and the done_lock spinlock. Thus we can be sure that as
1868 * long as we hold the driver's lock, the list will remain not
1869 * empty if list_empty() check succeeds.
1875 if (!q
->streaming
) {
1876 dprintk(1, "streaming off, will not wait for buffers\n");
1880 if (!list_empty(&q
->done_list
)) {
1882 * Found a buffer that we were waiting for.
1888 dprintk(1, "nonblocking and no buffers to dequeue, "
1894 * We are streaming and blocking, wait for another buffer to
1895 * become ready or for streamoff. Driver's lock is released to
1896 * allow streamoff or qbuf to be called while waiting.
1898 call_void_qop(q
, wait_prepare
, q
);
1901 * All locks have been released, it is safe to sleep now.
1903 dprintk(3, "will sleep waiting for buffers\n");
1904 ret
= wait_event_interruptible(q
->done_wq
,
1905 !list_empty(&q
->done_list
) || !q
->streaming
);
1908 * We need to reevaluate both conditions again after reacquiring
1909 * the locks or return an error if one occurred.
1911 call_void_qop(q
, wait_finish
, q
);
1913 dprintk(1, "sleep was interrupted\n");
1921 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1923 * Will sleep if required for nonblocking == false.
1925 static int __vb2_get_done_vb(struct vb2_queue
*q
, struct vb2_buffer
**vb
,
1926 struct v4l2_buffer
*b
, int nonblocking
)
1928 unsigned long flags
;
1932 * Wait for at least one buffer to become available on the done_list.
1934 ret
= __vb2_wait_for_done_vb(q
, nonblocking
);
1939 * Driver's lock has been held since we last verified that done_list
1940 * is not empty, so no need for another list_empty(done_list) check.
1942 spin_lock_irqsave(&q
->done_lock
, flags
);
1943 *vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
, done_entry
);
1945 * Only remove the buffer from done_list if v4l2_buffer can handle all
1948 ret
= __verify_planes_array(*vb
, b
);
1950 list_del(&(*vb
)->done_entry
);
1951 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1957 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1958 * @q: videobuf2 queue
1960 * This function will wait until all buffers that have been given to the driver
1961 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1962 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1963 * taken, for example from stop_streaming() callback.
1965 int vb2_wait_for_all_buffers(struct vb2_queue
*q
)
1967 if (!q
->streaming
) {
1968 dprintk(1, "streaming off, will not wait for buffers\n");
1972 if (q
->start_streaming_called
)
1973 wait_event(q
->done_wq
, !atomic_read(&q
->owned_by_drv_count
));
1976 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers
);
1979 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1981 static void __vb2_dqbuf(struct vb2_buffer
*vb
)
1983 struct vb2_queue
*q
= vb
->vb2_queue
;
1986 /* nothing to do if the buffer is already dequeued */
1987 if (vb
->state
== VB2_BUF_STATE_DEQUEUED
)
1990 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
1992 /* unmap DMABUF buffer */
1993 if (q
->memory
== V4L2_MEMORY_DMABUF
)
1994 for (i
= 0; i
< vb
->num_planes
; ++i
) {
1995 if (!vb
->planes
[i
].dbuf_mapped
)
1997 call_void_memop(vb
, unmap_dmabuf
, vb
->planes
[i
].mem_priv
);
1998 vb
->planes
[i
].dbuf_mapped
= 0;
2002 static int vb2_internal_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
2004 struct vb2_buffer
*vb
= NULL
;
2007 if (b
->type
!= q
->type
) {
2008 dprintk(1, "invalid buffer type\n");
2011 ret
= __vb2_get_done_vb(q
, &vb
, b
, nonblocking
);
2015 switch (vb
->state
) {
2016 case VB2_BUF_STATE_DONE
:
2017 dprintk(3, "returning done buffer\n");
2019 case VB2_BUF_STATE_ERROR
:
2020 dprintk(3, "returning done buffer with errors\n");
2023 dprintk(1, "invalid buffer state\n");
2027 call_void_vb_qop(vb
, buf_finish
, vb
);
2029 /* Fill buffer information for the userspace */
2030 __fill_v4l2_buffer(vb
, b
);
2031 /* Remove from videobuf queue */
2032 list_del(&vb
->queued_entry
);
2034 /* go back to dequeued state */
2037 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2038 vb
->v4l2_buf
.index
, vb
->state
);
2044 * vb2_dqbuf() - Dequeue a buffer to the userspace
2045 * @q: videobuf2 queue
2046 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2048 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2049 * buffers ready for dequeuing are present. Normally the driver
2050 * would be passing (file->f_flags & O_NONBLOCK) here
2052 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2054 * 1) verifies the passed buffer,
2055 * 2) calls buf_finish callback in the driver (if provided), in which
2056 * driver can perform any additional operations that may be required before
2057 * returning the buffer to userspace, such as cache sync,
2058 * 3) the buffer struct members are filled with relevant information for
2061 * The return values from this function are intended to be directly returned
2062 * from vidioc_dqbuf handler in driver.
2064 int vb2_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
2066 if (vb2_fileio_is_active(q
)) {
2067 dprintk(1, "file io in progress\n");
2070 return vb2_internal_dqbuf(q
, b
, nonblocking
);
2072 EXPORT_SYMBOL_GPL(vb2_dqbuf
);
2075 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2077 * Removes all queued buffers from driver's queue and all buffers queued by
2078 * userspace from videobuf's queue. Returns to state after reqbufs.
2080 static void __vb2_queue_cancel(struct vb2_queue
*q
)
2085 * Tell driver to stop all transactions and release all queued
2088 if (q
->start_streaming_called
)
2089 call_void_qop(q
, stop_streaming
, q
);
2091 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
2092 for (i
= 0; i
< q
->num_buffers
; ++i
)
2093 if (q
->bufs
[i
]->state
== VB2_BUF_STATE_ACTIVE
)
2094 vb2_buffer_done(q
->bufs
[i
], VB2_BUF_STATE_ERROR
);
2095 /* Must be zero now */
2096 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
2100 q
->start_streaming_called
= 0;
2101 q
->queued_count
= 0;
2104 * Remove all buffers from videobuf's list...
2106 INIT_LIST_HEAD(&q
->queued_list
);
2108 * ...and done list; userspace will not receive any buffers it
2109 * has not already dequeued before initiating cancel.
2111 INIT_LIST_HEAD(&q
->done_list
);
2112 atomic_set(&q
->owned_by_drv_count
, 0);
2113 wake_up_all(&q
->done_wq
);
2116 * Reinitialize all buffers for next use.
2117 * Make sure to call buf_finish for any queued buffers. Normally
2118 * that's done in dqbuf, but that's not going to happen when we
2119 * cancel the whole queue. Note: this code belongs here, not in
2120 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2121 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2122 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2124 for (i
= 0; i
< q
->num_buffers
; ++i
) {
2125 struct vb2_buffer
*vb
= q
->bufs
[i
];
2127 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
2128 vb
->state
= VB2_BUF_STATE_PREPARED
;
2129 call_void_vb_qop(vb
, buf_finish
, vb
);
2135 static int vb2_internal_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2139 if (type
!= q
->type
) {
2140 dprintk(1, "invalid stream type\n");
2145 dprintk(3, "already streaming\n");
2149 if (!q
->num_buffers
) {
2150 dprintk(1, "no buffers have been allocated\n");
2154 if (q
->num_buffers
< q
->min_buffers_needed
) {
2155 dprintk(1, "need at least %u allocated buffers\n",
2156 q
->min_buffers_needed
);
2161 * Tell driver to start streaming provided sufficient buffers
2164 if (q
->queued_count
>= q
->min_buffers_needed
) {
2165 ret
= vb2_start_streaming(q
);
2167 __vb2_queue_cancel(q
);
2174 dprintk(3, "successful\n");
2179 * vb2_streamon - start streaming
2180 * @q: videobuf2 queue
2181 * @type: type argument passed from userspace to vidioc_streamon handler
2183 * Should be called from vidioc_streamon handler of a driver.
2185 * 1) verifies current state
2186 * 2) passes any previously queued buffers to the driver and starts streaming
2188 * The return values from this function are intended to be directly returned
2189 * from vidioc_streamon handler in the driver.
2191 int vb2_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2193 if (vb2_fileio_is_active(q
)) {
2194 dprintk(1, "file io in progress\n");
2197 return vb2_internal_streamon(q
, type
);
2199 EXPORT_SYMBOL_GPL(vb2_streamon
);
2201 static int vb2_internal_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2203 if (type
!= q
->type
) {
2204 dprintk(1, "invalid stream type\n");
2209 * Cancel will pause streaming and remove all buffers from the driver
2210 * and videobuf, effectively returning control over them to userspace.
2212 * Note that we do this even if q->streaming == 0: if you prepare or
2213 * queue buffers, and then call streamoff without ever having called
2214 * streamon, you would still expect those buffers to be returned to
2215 * their normal dequeued state.
2217 __vb2_queue_cancel(q
);
2219 dprintk(3, "successful\n");
2224 * vb2_streamoff - stop streaming
2225 * @q: videobuf2 queue
2226 * @type: type argument passed from userspace to vidioc_streamoff handler
2228 * Should be called from vidioc_streamoff handler of a driver.
2230 * 1) verifies current state,
2231 * 2) stop streaming and dequeues any queued buffers, including those previously
2232 * passed to the driver (after waiting for the driver to finish).
2234 * This call can be used for pausing playback.
2235 * The return values from this function are intended to be directly returned
2236 * from vidioc_streamoff handler in the driver
2238 int vb2_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2240 if (vb2_fileio_is_active(q
)) {
2241 dprintk(1, "file io in progress\n");
2244 return vb2_internal_streamoff(q
, type
);
2246 EXPORT_SYMBOL_GPL(vb2_streamoff
);
2249 * __find_plane_by_offset() - find plane associated with the given offset off
2251 static int __find_plane_by_offset(struct vb2_queue
*q
, unsigned long off
,
2252 unsigned int *_buffer
, unsigned int *_plane
)
2254 struct vb2_buffer
*vb
;
2255 unsigned int buffer
, plane
;
2258 * Go over all buffers and their planes, comparing the given offset
2259 * with an offset assigned to each plane. If a match is found,
2260 * return its buffer and plane numbers.
2262 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
2263 vb
= q
->bufs
[buffer
];
2265 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
2266 if (vb
->v4l2_planes
[plane
].m
.mem_offset
== off
) {
2278 * vb2_expbuf() - Export a buffer as a file descriptor
2279 * @q: videobuf2 queue
2280 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2283 * The return values from this function are intended to be directly returned
2284 * from vidioc_expbuf handler in driver.
2286 int vb2_expbuf(struct vb2_queue
*q
, struct v4l2_exportbuffer
*eb
)
2288 struct vb2_buffer
*vb
= NULL
;
2289 struct vb2_plane
*vb_plane
;
2291 struct dma_buf
*dbuf
;
2293 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2294 dprintk(1, "queue is not currently set up for mmap\n");
2298 if (!q
->mem_ops
->get_dmabuf
) {
2299 dprintk(1, "queue does not support DMA buffer exporting\n");
2303 if (eb
->flags
& ~(O_CLOEXEC
| O_ACCMODE
)) {
2304 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2308 if (eb
->type
!= q
->type
) {
2309 dprintk(1, "invalid buffer type\n");
2313 if (eb
->index
>= q
->num_buffers
) {
2314 dprintk(1, "buffer index out of range\n");
2318 vb
= q
->bufs
[eb
->index
];
2320 if (eb
->plane
>= vb
->num_planes
) {
2321 dprintk(1, "buffer plane out of range\n");
2325 if (vb2_fileio_is_active(q
)) {
2326 dprintk(1, "expbuf: file io in progress\n");
2330 vb_plane
= &vb
->planes
[eb
->plane
];
2332 dbuf
= call_ptr_memop(vb
, get_dmabuf
, vb_plane
->mem_priv
, eb
->flags
& O_ACCMODE
);
2333 if (IS_ERR_OR_NULL(dbuf
)) {
2334 dprintk(1, "failed to export buffer %d, plane %d\n",
2335 eb
->index
, eb
->plane
);
2339 ret
= dma_buf_fd(dbuf
, eb
->flags
& ~O_ACCMODE
);
2341 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2342 eb
->index
, eb
->plane
, ret
);
2347 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2348 eb
->index
, eb
->plane
, ret
);
2353 EXPORT_SYMBOL_GPL(vb2_expbuf
);
2356 * vb2_mmap() - map video buffers into application address space
2357 * @q: videobuf2 queue
2358 * @vma: vma passed to the mmap file operation handler in the driver
2360 * Should be called from mmap file operation handler of a driver.
2361 * This function maps one plane of one of the available video buffers to
2362 * userspace. To map whole video memory allocated on reqbufs, this function
2363 * has to be called once per each plane per each buffer previously allocated.
2365 * When the userspace application calls mmap, it passes to it an offset returned
2366 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2367 * a "cookie", which is then used to identify the plane to be mapped.
2368 * This function finds a plane with a matching offset and a mapping is performed
2369 * by the means of a provided memory operation.
2371 * The return values from this function are intended to be directly returned
2372 * from the mmap handler in driver.
2374 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
)
2376 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
2377 struct vb2_buffer
*vb
;
2378 unsigned int buffer
= 0, plane
= 0;
2380 unsigned long length
;
2382 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2383 dprintk(1, "queue is not currently set up for mmap\n");
2388 * Check memory area access mode.
2390 if (!(vma
->vm_flags
& VM_SHARED
)) {
2391 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2394 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
2395 if (!(vma
->vm_flags
& VM_WRITE
)) {
2396 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2400 if (!(vma
->vm_flags
& VM_READ
)) {
2401 dprintk(1, "invalid vma flags, VM_READ needed\n");
2405 if (vb2_fileio_is_active(q
)) {
2406 dprintk(1, "mmap: file io in progress\n");
2411 * Find the plane corresponding to the offset passed by userspace.
2413 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2417 vb
= q
->bufs
[buffer
];
2420 * MMAP requires page_aligned buffers.
2421 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2422 * so, we need to do the same here.
2424 length
= PAGE_ALIGN(vb
->v4l2_planes
[plane
].length
);
2425 if (length
< (vma
->vm_end
- vma
->vm_start
)) {
2427 "MMAP invalid, as it would overflow buffer length\n");
2431 ret
= call_memop(vb
, mmap
, vb
->planes
[plane
].mem_priv
, vma
);
2435 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer
, plane
);
2438 EXPORT_SYMBOL_GPL(vb2_mmap
);
2441 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
2444 unsigned long pgoff
,
2445 unsigned long flags
)
2447 unsigned long off
= pgoff
<< PAGE_SHIFT
;
2448 struct vb2_buffer
*vb
;
2449 unsigned int buffer
, plane
;
2452 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2453 dprintk(1, "queue is not currently set up for mmap\n");
2458 * Find the plane corresponding to the offset passed by userspace.
2460 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2464 vb
= q
->bufs
[buffer
];
2466 return (unsigned long)vb2_plane_vaddr(vb
, plane
);
2468 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area
);
2471 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
);
2472 static int __vb2_cleanup_fileio(struct vb2_queue
*q
);
2475 * vb2_poll() - implements poll userspace operation
2476 * @q: videobuf2 queue
2477 * @file: file argument passed to the poll file operation handler
2478 * @wait: wait argument passed to the poll file operation handler
2480 * This function implements poll file operation handler for a driver.
2481 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2482 * be informed that the file descriptor of a video device is available for
2484 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2485 * will be reported as available for writing.
2487 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2490 * The return values from this function are intended to be directly returned
2491 * from poll handler in driver.
2493 unsigned int vb2_poll(struct vb2_queue
*q
, struct file
*file
, poll_table
*wait
)
2495 struct video_device
*vfd
= video_devdata(file
);
2496 unsigned long req_events
= poll_requested_events(wait
);
2497 struct vb2_buffer
*vb
= NULL
;
2498 unsigned int res
= 0;
2499 unsigned long flags
;
2501 if (test_bit(V4L2_FL_USES_V4L2_FH
, &vfd
->flags
)) {
2502 struct v4l2_fh
*fh
= file
->private_data
;
2504 if (v4l2_event_pending(fh
))
2506 else if (req_events
& POLLPRI
)
2507 poll_wait(file
, &fh
->wait
, wait
);
2510 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLIN
| POLLRDNORM
)))
2512 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLOUT
| POLLWRNORM
)))
2516 * Start file I/O emulator only if streaming API has not been used yet.
2518 if (q
->num_buffers
== 0 && !vb2_fileio_is_active(q
)) {
2519 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_READ
) &&
2520 (req_events
& (POLLIN
| POLLRDNORM
))) {
2521 if (__vb2_init_fileio(q
, 1))
2522 return res
| POLLERR
;
2524 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_WRITE
) &&
2525 (req_events
& (POLLOUT
| POLLWRNORM
))) {
2526 if (__vb2_init_fileio(q
, 0))
2527 return res
| POLLERR
;
2529 * Write to OUTPUT queue can be done immediately.
2531 return res
| POLLOUT
| POLLWRNORM
;
2536 * There is nothing to wait for if no buffers have already been queued.
2538 if (list_empty(&q
->queued_list
))
2539 return res
| POLLERR
;
2541 if (list_empty(&q
->done_list
))
2542 poll_wait(file
, &q
->done_wq
, wait
);
2545 * Take first buffer available for dequeuing.
2547 spin_lock_irqsave(&q
->done_lock
, flags
);
2548 if (!list_empty(&q
->done_list
))
2549 vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
,
2551 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2553 if (vb
&& (vb
->state
== VB2_BUF_STATE_DONE
2554 || vb
->state
== VB2_BUF_STATE_ERROR
)) {
2555 return (V4L2_TYPE_IS_OUTPUT(q
->type
)) ?
2556 res
| POLLOUT
| POLLWRNORM
:
2557 res
| POLLIN
| POLLRDNORM
;
2561 EXPORT_SYMBOL_GPL(vb2_poll
);
2564 * vb2_queue_init() - initialize a videobuf2 queue
2565 * @q: videobuf2 queue; this structure should be allocated in driver
2567 * The vb2_queue structure should be allocated by the driver. The driver is
2568 * responsible of clearing it's content and setting initial values for some
2569 * required entries before calling this function.
2570 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2571 * to the struct vb2_queue description in include/media/videobuf2-core.h
2572 * for more information.
2574 int vb2_queue_init(struct vb2_queue
*q
)
2581 WARN_ON(!q
->mem_ops
) ||
2582 WARN_ON(!q
->type
) ||
2583 WARN_ON(!q
->io_modes
) ||
2584 WARN_ON(!q
->ops
->queue_setup
) ||
2585 WARN_ON(!q
->ops
->buf_queue
) ||
2586 WARN_ON(q
->timestamp_flags
&
2587 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK
|
2588 V4L2_BUF_FLAG_TSTAMP_SRC_MASK
)))
2591 /* Warn that the driver should choose an appropriate timestamp type */
2592 WARN_ON((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
2593 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN
);
2595 INIT_LIST_HEAD(&q
->queued_list
);
2596 INIT_LIST_HEAD(&q
->done_list
);
2597 spin_lock_init(&q
->done_lock
);
2598 init_waitqueue_head(&q
->done_wq
);
2600 if (q
->buf_struct_size
== 0)
2601 q
->buf_struct_size
= sizeof(struct vb2_buffer
);
2605 EXPORT_SYMBOL_GPL(vb2_queue_init
);
2608 * vb2_queue_release() - stop streaming, release the queue and free memory
2609 * @q: videobuf2 queue
2611 * This function stops streaming and performs necessary clean ups, including
2612 * freeing video buffer memory. The driver is responsible for freeing
2613 * the vb2_queue structure itself.
2615 void vb2_queue_release(struct vb2_queue
*q
)
2617 __vb2_cleanup_fileio(q
);
2618 __vb2_queue_cancel(q
);
2619 __vb2_queue_free(q
, q
->num_buffers
);
2621 EXPORT_SYMBOL_GPL(vb2_queue_release
);
2624 * struct vb2_fileio_buf - buffer context used by file io emulator
2626 * vb2 provides a compatibility layer and emulator of file io (read and
2627 * write) calls on top of streaming API. This structure is used for
2628 * tracking context related to the buffers.
2630 struct vb2_fileio_buf
{
2634 unsigned int queued
:1;
2638 * struct vb2_fileio_data - queue context used by file io emulator
2640 * @cur_index: the index of the buffer currently being read from or
2641 * written to. If equal to q->num_buffers then a new buffer
2643 * @initial_index: in the read() case all buffers are queued up immediately
2644 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2645 * buffers. However, in the write() case no buffers are initially
2646 * queued, instead whenever a buffer is full it is queued up by
2647 * __vb2_perform_fileio(). Only once all available buffers have
2648 * been queued up will __vb2_perform_fileio() start to dequeue
2649 * buffers. This means that initially __vb2_perform_fileio()
2650 * needs to know what buffer index to use when it is queuing up
2651 * the buffers for the first time. That initial index is stored
2652 * in this field. Once it is equal to q->num_buffers all
2653 * available buffers have been queued and __vb2_perform_fileio()
2654 * should start the normal dequeue/queue cycle.
2656 * vb2 provides a compatibility layer and emulator of file io (read and
2657 * write) calls on top of streaming API. For proper operation it required
2658 * this structure to save the driver state between each call of the read
2659 * or write function.
2661 struct vb2_fileio_data
{
2662 struct v4l2_requestbuffers req
;
2663 struct v4l2_plane p
;
2664 struct v4l2_buffer b
;
2665 struct vb2_fileio_buf bufs
[VIDEO_MAX_FRAME
];
2666 unsigned int cur_index
;
2667 unsigned int initial_index
;
2668 unsigned int q_count
;
2669 unsigned int dq_count
;
2674 * __vb2_init_fileio() - initialize file io emulator
2675 * @q: videobuf2 queue
2676 * @read: mode selector (1 means read, 0 means write)
2678 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
)
2680 struct vb2_fileio_data
*fileio
;
2682 unsigned int count
= 0;
2687 if (WARN_ON((read
&& !(q
->io_modes
& VB2_READ
)) ||
2688 (!read
&& !(q
->io_modes
& VB2_WRITE
))))
2692 * Check if device supports mapping buffers to kernel virtual space.
2694 if (!q
->mem_ops
->vaddr
)
2698 * Check if streaming api has not been already activated.
2700 if (q
->streaming
|| q
->num_buffers
> 0)
2704 * Start with count 1, driver can increase it in queue_setup()
2708 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2709 (read
) ? "read" : "write", count
, q
->io_flags
);
2711 fileio
= kzalloc(sizeof(struct vb2_fileio_data
), GFP_KERNEL
);
2715 fileio
->flags
= q
->io_flags
;
2718 * Request buffers and use MMAP type to force driver
2719 * to allocate buffers by itself.
2721 fileio
->req
.count
= count
;
2722 fileio
->req
.memory
= V4L2_MEMORY_MMAP
;
2723 fileio
->req
.type
= q
->type
;
2725 ret
= __reqbufs(q
, &fileio
->req
);
2730 * Check if plane_count is correct
2731 * (multiplane buffers are not supported).
2733 if (q
->bufs
[0]->num_planes
!= 1) {
2739 * Get kernel address of each buffer.
2741 for (i
= 0; i
< q
->num_buffers
; i
++) {
2742 fileio
->bufs
[i
].vaddr
= vb2_plane_vaddr(q
->bufs
[i
], 0);
2743 if (fileio
->bufs
[i
].vaddr
== NULL
) {
2747 fileio
->bufs
[i
].size
= vb2_plane_size(q
->bufs
[i
], 0);
2751 * Read mode requires pre queuing of all buffers.
2754 bool is_multiplanar
= V4L2_TYPE_IS_MULTIPLANAR(q
->type
);
2757 * Queue all buffers.
2759 for (i
= 0; i
< q
->num_buffers
; i
++) {
2760 struct v4l2_buffer
*b
= &fileio
->b
;
2762 memset(b
, 0, sizeof(*b
));
2764 if (is_multiplanar
) {
2765 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
2766 b
->m
.planes
= &fileio
->p
;
2769 b
->memory
= q
->memory
;
2771 ret
= vb2_internal_qbuf(q
, b
);
2774 fileio
->bufs
[i
].queued
= 1;
2777 * All buffers have been queued, so mark that by setting
2778 * initial_index to q->num_buffers
2780 fileio
->initial_index
= q
->num_buffers
;
2781 fileio
->cur_index
= q
->num_buffers
;
2787 ret
= vb2_internal_streamon(q
, q
->type
);
2794 fileio
->req
.count
= 0;
2795 __reqbufs(q
, &fileio
->req
);
2804 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2805 * @q: videobuf2 queue
2807 static int __vb2_cleanup_fileio(struct vb2_queue
*q
)
2809 struct vb2_fileio_data
*fileio
= q
->fileio
;
2812 vb2_internal_streamoff(q
, q
->type
);
2814 fileio
->req
.count
= 0;
2815 vb2_reqbufs(q
, &fileio
->req
);
2817 dprintk(3, "file io emulator closed\n");
2823 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2824 * @q: videobuf2 queue
2825 * @data: pointed to target userspace buffer
2826 * @count: number of bytes to read or write
2827 * @ppos: file handle position tracking pointer
2828 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2829 * @read: access mode selector (1 means read, 0 means write)
2831 static size_t __vb2_perform_fileio(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2832 loff_t
*ppos
, int nonblock
, int read
)
2834 struct vb2_fileio_data
*fileio
;
2835 struct vb2_fileio_buf
*buf
;
2836 bool is_multiplanar
= V4L2_TYPE_IS_MULTIPLANAR(q
->type
);
2838 * When using write() to write data to an output video node the vb2 core
2839 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2840 * else is able to provide this information with the write() operation.
2842 bool set_timestamp
= !read
&&
2843 (q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
2844 V4L2_BUF_FLAG_TIMESTAMP_COPY
;
2847 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2848 read
? "read" : "write", (long)*ppos
, count
,
2849 nonblock
? "non" : "");
2855 * Initialize emulator on first call.
2857 if (!vb2_fileio_is_active(q
)) {
2858 ret
= __vb2_init_fileio(q
, read
);
2859 dprintk(3, "vb2_init_fileio result: %d\n", ret
);
2866 * Check if we need to dequeue the buffer.
2868 index
= fileio
->cur_index
;
2869 if (index
>= q
->num_buffers
) {
2871 * Call vb2_dqbuf to get buffer back.
2873 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
2874 fileio
->b
.type
= q
->type
;
2875 fileio
->b
.memory
= q
->memory
;
2876 if (is_multiplanar
) {
2877 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
2878 fileio
->b
.m
.planes
= &fileio
->p
;
2879 fileio
->b
.length
= 1;
2881 ret
= vb2_internal_dqbuf(q
, &fileio
->b
, nonblock
);
2882 dprintk(5, "vb2_dqbuf result: %d\n", ret
);
2885 fileio
->dq_count
+= 1;
2887 fileio
->cur_index
= index
= fileio
->b
.index
;
2888 buf
= &fileio
->bufs
[index
];
2891 * Get number of bytes filled by the driver
2895 buf
->size
= read
? vb2_get_plane_payload(q
->bufs
[index
], 0)
2896 : vb2_plane_size(q
->bufs
[index
], 0);
2898 buf
= &fileio
->bufs
[index
];
2902 * Limit count on last few bytes of the buffer.
2904 if (buf
->pos
+ count
> buf
->size
) {
2905 count
= buf
->size
- buf
->pos
;
2906 dprintk(5, "reducing read count: %zd\n", count
);
2910 * Transfer data to userspace.
2912 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2913 count
, index
, buf
->pos
);
2915 ret
= copy_to_user(data
, buf
->vaddr
+ buf
->pos
, count
);
2917 ret
= copy_from_user(buf
->vaddr
+ buf
->pos
, data
, count
);
2919 dprintk(3, "error copying data\n");
2930 * Queue next buffer if required.
2932 if (buf
->pos
== buf
->size
||
2933 (!read
&& (fileio
->flags
& VB2_FILEIO_WRITE_IMMEDIATELY
))) {
2935 * Check if this is the last buffer to read.
2937 if (read
&& (fileio
->flags
& VB2_FILEIO_READ_ONCE
) &&
2938 fileio
->dq_count
== 1) {
2939 dprintk(3, "read limit reached\n");
2940 return __vb2_cleanup_fileio(q
);
2944 * Call vb2_qbuf and give buffer to the driver.
2946 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
2947 fileio
->b
.type
= q
->type
;
2948 fileio
->b
.memory
= q
->memory
;
2949 fileio
->b
.index
= index
;
2950 fileio
->b
.bytesused
= buf
->pos
;
2951 if (is_multiplanar
) {
2952 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
2953 fileio
->p
.bytesused
= buf
->pos
;
2954 fileio
->b
.m
.planes
= &fileio
->p
;
2955 fileio
->b
.length
= 1;
2958 v4l2_get_timestamp(&fileio
->b
.timestamp
);
2959 ret
= vb2_internal_qbuf(q
, &fileio
->b
);
2960 dprintk(5, "vb2_dbuf result: %d\n", ret
);
2965 * Buffer has been queued, update the status
2969 buf
->size
= vb2_plane_size(q
->bufs
[index
], 0);
2970 fileio
->q_count
+= 1;
2972 * If we are queuing up buffers for the first time, then
2973 * increase initial_index by one.
2975 if (fileio
->initial_index
< q
->num_buffers
)
2976 fileio
->initial_index
++;
2978 * The next buffer to use is either a buffer that's going to be
2979 * queued for the first time (initial_index < q->num_buffers)
2980 * or it is equal to q->num_buffers, meaning that the next
2981 * time we need to dequeue a buffer since we've now queued up
2982 * all the 'first time' buffers.
2984 fileio
->cur_index
= fileio
->initial_index
;
2988 * Return proper number of bytes processed.
2995 size_t vb2_read(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2996 loff_t
*ppos
, int nonblocking
)
2998 return __vb2_perform_fileio(q
, data
, count
, ppos
, nonblocking
, 1);
3000 EXPORT_SYMBOL_GPL(vb2_read
);
3002 size_t vb2_write(struct vb2_queue
*q
, const char __user
*data
, size_t count
,
3003 loff_t
*ppos
, int nonblocking
)
3005 return __vb2_perform_fileio(q
, (char __user
*) data
, count
,
3006 ppos
, nonblocking
, 0);
3008 EXPORT_SYMBOL_GPL(vb2_write
);
3010 struct vb2_threadio_data
{
3011 struct task_struct
*thread
;
3017 static int vb2_thread(void *data
)
3019 struct vb2_queue
*q
= data
;
3020 struct vb2_threadio_data
*threadio
= q
->threadio
;
3021 struct vb2_fileio_data
*fileio
= q
->fileio
;
3022 bool set_timestamp
= false;
3027 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
3028 prequeue
= q
->num_buffers
;
3030 (q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
3031 V4L2_BUF_FLAG_TIMESTAMP_COPY
;
3037 struct vb2_buffer
*vb
;
3040 * Call vb2_dqbuf to get buffer back.
3042 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3043 fileio
->b
.type
= q
->type
;
3044 fileio
->b
.memory
= q
->memory
;
3046 fileio
->b
.index
= index
++;
3049 call_void_qop(q
, wait_finish
, q
);
3050 ret
= vb2_internal_dqbuf(q
, &fileio
->b
, 0);
3051 call_void_qop(q
, wait_prepare
, q
);
3052 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret
);
3060 vb
= q
->bufs
[fileio
->b
.index
];
3061 if (!(fileio
->b
.flags
& V4L2_BUF_FLAG_ERROR
))
3062 ret
= threadio
->fnc(vb
, threadio
->priv
);
3065 call_void_qop(q
, wait_finish
, q
);
3067 v4l2_get_timestamp(&fileio
->b
.timestamp
);
3068 ret
= vb2_internal_qbuf(q
, &fileio
->b
);
3069 call_void_qop(q
, wait_prepare
, q
);
3074 /* Hmm, linux becomes *very* unhappy without this ... */
3075 while (!kthread_should_stop()) {
3076 set_current_state(TASK_INTERRUPTIBLE
);
3083 * This function should not be used for anything else but the videobuf2-dvb
3084 * support. If you think you have another good use-case for this, then please
3085 * contact the linux-media mailinglist first.
3087 int vb2_thread_start(struct vb2_queue
*q
, vb2_thread_fnc fnc
, void *priv
,
3088 const char *thread_name
)
3090 struct vb2_threadio_data
*threadio
;
3097 if (WARN_ON(q
->fileio
))
3100 threadio
= kzalloc(sizeof(*threadio
), GFP_KERNEL
);
3101 if (threadio
== NULL
)
3103 threadio
->fnc
= fnc
;
3104 threadio
->priv
= priv
;
3106 ret
= __vb2_init_fileio(q
, !V4L2_TYPE_IS_OUTPUT(q
->type
));
3107 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret
);
3110 q
->threadio
= threadio
;
3111 threadio
->thread
= kthread_run(vb2_thread
, q
, "vb2-%s", thread_name
);
3112 if (IS_ERR(threadio
->thread
)) {
3113 ret
= PTR_ERR(threadio
->thread
);
3114 threadio
->thread
= NULL
;
3120 __vb2_cleanup_fileio(q
);
3125 EXPORT_SYMBOL_GPL(vb2_thread_start
);
3127 int vb2_thread_stop(struct vb2_queue
*q
)
3129 struct vb2_threadio_data
*threadio
= q
->threadio
;
3130 struct vb2_fileio_data
*fileio
= q
->fileio
;
3133 if (threadio
== NULL
)
3135 call_void_qop(q
, wait_finish
, q
);
3136 threadio
->stop
= true;
3137 vb2_internal_streamoff(q
, q
->type
);
3138 call_void_qop(q
, wait_prepare
, q
);
3140 fileio
->req
.count
= 0;
3141 vb2_reqbufs(q
, &fileio
->req
);
3143 err
= kthread_stop(threadio
->thread
);
3144 threadio
->thread
= NULL
;
3150 EXPORT_SYMBOL_GPL(vb2_thread_stop
);
3153 * The following functions are not part of the vb2 core API, but are helper
3154 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3155 * and struct vb2_ops.
3156 * They contain boilerplate code that most if not all drivers have to do
3157 * and so they simplify the driver code.
3160 /* The queue is busy if there is a owner and you are not that owner. */
3161 static inline bool vb2_queue_is_busy(struct video_device
*vdev
, struct file
*file
)
3163 return vdev
->queue
->owner
&& vdev
->queue
->owner
!= file
->private_data
;
3166 /* vb2 ioctl helpers */
3168 int vb2_ioctl_reqbufs(struct file
*file
, void *priv
,
3169 struct v4l2_requestbuffers
*p
)
3171 struct video_device
*vdev
= video_devdata(file
);
3172 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->type
);
3176 if (vb2_queue_is_busy(vdev
, file
))
3178 res
= __reqbufs(vdev
->queue
, p
);
3179 /* If count == 0, then the owner has released all buffers and he
3180 is no longer owner of the queue. Otherwise we have a new owner. */
3182 vdev
->queue
->owner
= p
->count
? file
->private_data
: NULL
;
3185 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs
);
3187 int vb2_ioctl_create_bufs(struct file
*file
, void *priv
,
3188 struct v4l2_create_buffers
*p
)
3190 struct video_device
*vdev
= video_devdata(file
);
3191 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->format
.type
);
3193 p
->index
= vdev
->queue
->num_buffers
;
3194 /* If count == 0, then just check if memory and type are valid.
3195 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3197 return res
!= -EBUSY
? res
: 0;
3200 if (vb2_queue_is_busy(vdev
, file
))
3202 res
= __create_bufs(vdev
->queue
, p
);
3204 vdev
->queue
->owner
= file
->private_data
;
3207 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs
);
3209 int vb2_ioctl_prepare_buf(struct file
*file
, void *priv
,
3210 struct v4l2_buffer
*p
)
3212 struct video_device
*vdev
= video_devdata(file
);
3214 if (vb2_queue_is_busy(vdev
, file
))
3216 return vb2_prepare_buf(vdev
->queue
, p
);
3218 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf
);
3220 int vb2_ioctl_querybuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3222 struct video_device
*vdev
= video_devdata(file
);
3224 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3225 return vb2_querybuf(vdev
->queue
, p
);
3227 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf
);
3229 int vb2_ioctl_qbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3231 struct video_device
*vdev
= video_devdata(file
);
3233 if (vb2_queue_is_busy(vdev
, file
))
3235 return vb2_qbuf(vdev
->queue
, p
);
3237 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf
);
3239 int vb2_ioctl_dqbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3241 struct video_device
*vdev
= video_devdata(file
);
3243 if (vb2_queue_is_busy(vdev
, file
))
3245 return vb2_dqbuf(vdev
->queue
, p
, file
->f_flags
& O_NONBLOCK
);
3247 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf
);
3249 int vb2_ioctl_streamon(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
3251 struct video_device
*vdev
= video_devdata(file
);
3253 if (vb2_queue_is_busy(vdev
, file
))
3255 return vb2_streamon(vdev
->queue
, i
);
3257 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon
);
3259 int vb2_ioctl_streamoff(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
3261 struct video_device
*vdev
= video_devdata(file
);
3263 if (vb2_queue_is_busy(vdev
, file
))
3265 return vb2_streamoff(vdev
->queue
, i
);
3267 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff
);
3269 int vb2_ioctl_expbuf(struct file
*file
, void *priv
, struct v4l2_exportbuffer
*p
)
3271 struct video_device
*vdev
= video_devdata(file
);
3273 if (vb2_queue_is_busy(vdev
, file
))
3275 return vb2_expbuf(vdev
->queue
, p
);
3277 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf
);
3279 /* v4l2_file_operations helpers */
3281 int vb2_fop_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3283 struct video_device
*vdev
= video_devdata(file
);
3284 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3287 if (lock
&& mutex_lock_interruptible(lock
))
3288 return -ERESTARTSYS
;
3289 err
= vb2_mmap(vdev
->queue
, vma
);
3294 EXPORT_SYMBOL_GPL(vb2_fop_mmap
);
3296 int _vb2_fop_release(struct file
*file
, struct mutex
*lock
)
3298 struct video_device
*vdev
= video_devdata(file
);
3300 if (file
->private_data
== vdev
->queue
->owner
) {
3303 vb2_queue_release(vdev
->queue
);
3304 vdev
->queue
->owner
= NULL
;
3308 return v4l2_fh_release(file
);
3310 EXPORT_SYMBOL_GPL(_vb2_fop_release
);
3312 int vb2_fop_release(struct file
*file
)
3314 struct video_device
*vdev
= video_devdata(file
);
3315 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3317 return _vb2_fop_release(file
, lock
);
3319 EXPORT_SYMBOL_GPL(vb2_fop_release
);
3321 ssize_t
vb2_fop_write(struct file
*file
, const char __user
*buf
,
3322 size_t count
, loff_t
*ppos
)
3324 struct video_device
*vdev
= video_devdata(file
);
3325 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3328 if (lock
&& mutex_lock_interruptible(lock
))
3329 return -ERESTARTSYS
;
3330 if (vb2_queue_is_busy(vdev
, file
))
3332 err
= vb2_write(vdev
->queue
, buf
, count
, ppos
,
3333 file
->f_flags
& O_NONBLOCK
);
3334 if (vdev
->queue
->fileio
)
3335 vdev
->queue
->owner
= file
->private_data
;
3341 EXPORT_SYMBOL_GPL(vb2_fop_write
);
3343 ssize_t
vb2_fop_read(struct file
*file
, char __user
*buf
,
3344 size_t count
, loff_t
*ppos
)
3346 struct video_device
*vdev
= video_devdata(file
);
3347 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3350 if (lock
&& mutex_lock_interruptible(lock
))
3351 return -ERESTARTSYS
;
3352 if (vb2_queue_is_busy(vdev
, file
))
3354 err
= vb2_read(vdev
->queue
, buf
, count
, ppos
,
3355 file
->f_flags
& O_NONBLOCK
);
3356 if (vdev
->queue
->fileio
)
3357 vdev
->queue
->owner
= file
->private_data
;
3363 EXPORT_SYMBOL_GPL(vb2_fop_read
);
3365 unsigned int vb2_fop_poll(struct file
*file
, poll_table
*wait
)
3367 struct video_device
*vdev
= video_devdata(file
);
3368 struct vb2_queue
*q
= vdev
->queue
;
3369 struct mutex
*lock
= q
->lock
? q
->lock
: vdev
->lock
;
3370 unsigned long req_events
= poll_requested_events(wait
);
3373 bool must_lock
= false;
3375 /* Try to be smart: only lock if polling might start fileio,
3376 otherwise locking will only introduce unwanted delays. */
3377 if (q
->num_buffers
== 0 && !vb2_fileio_is_active(q
)) {
3378 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_READ
) &&
3379 (req_events
& (POLLIN
| POLLRDNORM
)))
3381 else if (V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_WRITE
) &&
3382 (req_events
& (POLLOUT
| POLLWRNORM
)))
3386 /* If locking is needed, but this helper doesn't know how, then you
3387 shouldn't be using this helper but you should write your own. */
3388 WARN_ON(must_lock
&& !lock
);
3390 if (must_lock
&& lock
&& mutex_lock_interruptible(lock
))
3395 res
= vb2_poll(vdev
->queue
, file
, wait
);
3397 /* If fileio was started, then we have a new queue owner. */
3398 if (must_lock
&& !fileio
&& q
->fileio
)
3399 q
->owner
= file
->private_data
;
3400 if (must_lock
&& lock
)
3404 EXPORT_SYMBOL_GPL(vb2_fop_poll
);
3407 unsigned long vb2_fop_get_unmapped_area(struct file
*file
, unsigned long addr
,
3408 unsigned long len
, unsigned long pgoff
, unsigned long flags
)
3410 struct video_device
*vdev
= video_devdata(file
);
3411 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3414 if (lock
&& mutex_lock_interruptible(lock
))
3415 return -ERESTARTSYS
;
3416 ret
= vb2_get_unmapped_area(vdev
->queue
, addr
, len
, pgoff
, flags
);
3421 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area
);
3424 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3426 void vb2_ops_wait_prepare(struct vb2_queue
*vq
)
3428 mutex_unlock(vq
->lock
);
3430 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare
);
3432 void vb2_ops_wait_finish(struct vb2_queue
*vq
)
3434 mutex_lock(vq
->lock
);
3436 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish
);
3438 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3439 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3440 MODULE_LICENSE("GPL");