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_info("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
;
192 enum dma_data_direction dma_dir
=
193 V4L2_TYPE_IS_OUTPUT(q
->type
) ? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
198 * Allocate memory for all planes in this buffer
199 * NOTE: mmapped areas should be page aligned
201 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
202 unsigned long size
= PAGE_ALIGN(q
->plane_sizes
[plane
]);
204 mem_priv
= call_ptr_memop(vb
, alloc
, q
->alloc_ctx
[plane
],
205 size
, dma_dir
, q
->gfp_flags
);
206 if (IS_ERR_OR_NULL(mem_priv
))
209 /* Associate allocator private data with this plane */
210 vb
->planes
[plane
].mem_priv
= mem_priv
;
211 vb
->v4l2_planes
[plane
].length
= q
->plane_sizes
[plane
];
216 /* Free already allocated memory if one of the allocations failed */
217 for (; plane
> 0; --plane
) {
218 call_void_memop(vb
, put
, vb
->planes
[plane
- 1].mem_priv
);
219 vb
->planes
[plane
- 1].mem_priv
= NULL
;
226 * __vb2_buf_mem_free() - free memory of the given buffer
228 static void __vb2_buf_mem_free(struct vb2_buffer
*vb
)
232 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
233 call_void_memop(vb
, put
, vb
->planes
[plane
].mem_priv
);
234 vb
->planes
[plane
].mem_priv
= NULL
;
235 dprintk(3, "freed plane %d of buffer %d\n", plane
,
241 * __vb2_buf_userptr_put() - release userspace memory associated with
244 static void __vb2_buf_userptr_put(struct vb2_buffer
*vb
)
248 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
249 if (vb
->planes
[plane
].mem_priv
)
250 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
251 vb
->planes
[plane
].mem_priv
= NULL
;
256 * __vb2_plane_dmabuf_put() - release memory associated with
257 * a DMABUF shared plane
259 static void __vb2_plane_dmabuf_put(struct vb2_buffer
*vb
, struct vb2_plane
*p
)
265 call_void_memop(vb
, unmap_dmabuf
, p
->mem_priv
);
267 call_void_memop(vb
, detach_dmabuf
, p
->mem_priv
);
268 dma_buf_put(p
->dbuf
);
269 memset(p
, 0, sizeof(*p
));
273 * __vb2_buf_dmabuf_put() - release memory associated with
274 * a DMABUF shared buffer
276 static void __vb2_buf_dmabuf_put(struct vb2_buffer
*vb
)
280 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
281 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
285 * __setup_lengths() - setup initial lengths for every plane in
286 * every buffer on the queue
288 static void __setup_lengths(struct vb2_queue
*q
, unsigned int n
)
290 unsigned int buffer
, plane
;
291 struct vb2_buffer
*vb
;
293 for (buffer
= q
->num_buffers
; buffer
< q
->num_buffers
+ n
; ++buffer
) {
294 vb
= q
->bufs
[buffer
];
298 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
299 vb
->v4l2_planes
[plane
].length
= q
->plane_sizes
[plane
];
304 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
305 * every buffer on the queue
307 static void __setup_offsets(struct vb2_queue
*q
, unsigned int n
)
309 unsigned int buffer
, plane
;
310 struct vb2_buffer
*vb
;
313 if (q
->num_buffers
) {
314 struct v4l2_plane
*p
;
315 vb
= q
->bufs
[q
->num_buffers
- 1];
316 p
= &vb
->v4l2_planes
[vb
->num_planes
- 1];
317 off
= PAGE_ALIGN(p
->m
.mem_offset
+ p
->length
);
322 for (buffer
= q
->num_buffers
; buffer
< q
->num_buffers
+ n
; ++buffer
) {
323 vb
= q
->bufs
[buffer
];
327 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
328 vb
->v4l2_planes
[plane
].m
.mem_offset
= off
;
330 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
333 off
+= vb
->v4l2_planes
[plane
].length
;
334 off
= PAGE_ALIGN(off
);
340 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
341 * video buffer memory for all buffers/planes on the queue and initializes the
344 * Returns the number of buffers successfully allocated.
346 static int __vb2_queue_alloc(struct vb2_queue
*q
, enum v4l2_memory memory
,
347 unsigned int num_buffers
, unsigned int num_planes
)
350 struct vb2_buffer
*vb
;
353 for (buffer
= 0; buffer
< num_buffers
; ++buffer
) {
354 /* Allocate videobuf buffer structures */
355 vb
= kzalloc(q
->buf_struct_size
, GFP_KERNEL
);
357 dprintk(1, "memory alloc for buffer struct failed\n");
361 /* Length stores number of planes for multiplanar buffers */
362 if (V4L2_TYPE_IS_MULTIPLANAR(q
->type
))
363 vb
->v4l2_buf
.length
= num_planes
;
365 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
367 vb
->num_planes
= num_planes
;
368 vb
->v4l2_buf
.index
= q
->num_buffers
+ buffer
;
369 vb
->v4l2_buf
.type
= q
->type
;
370 vb
->v4l2_buf
.memory
= memory
;
372 /* Allocate video buffer memory for the MMAP type */
373 if (memory
== V4L2_MEMORY_MMAP
) {
374 ret
= __vb2_buf_mem_alloc(vb
);
376 dprintk(1, "failed allocating memory for "
377 "buffer %d\n", buffer
);
382 * Call the driver-provided buffer initialization
383 * callback, if given. An error in initialization
384 * results in queue setup failure.
386 ret
= call_vb_qop(vb
, buf_init
, vb
);
388 dprintk(1, "buffer %d %p initialization"
389 " failed\n", buffer
, vb
);
390 __vb2_buf_mem_free(vb
);
396 q
->bufs
[q
->num_buffers
+ buffer
] = vb
;
399 __setup_lengths(q
, buffer
);
400 if (memory
== V4L2_MEMORY_MMAP
)
401 __setup_offsets(q
, buffer
);
403 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
410 * __vb2_free_mem() - release all video buffer memory for a given queue
412 static void __vb2_free_mem(struct vb2_queue
*q
, unsigned int buffers
)
415 struct vb2_buffer
*vb
;
417 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
419 vb
= q
->bufs
[buffer
];
423 /* Free MMAP buffers or release USERPTR buffers */
424 if (q
->memory
== V4L2_MEMORY_MMAP
)
425 __vb2_buf_mem_free(vb
);
426 else if (q
->memory
== V4L2_MEMORY_DMABUF
)
427 __vb2_buf_dmabuf_put(vb
);
429 __vb2_buf_userptr_put(vb
);
434 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
435 * related information, if no buffers are left return the queue to an
436 * uninitialized state. Might be called even if the queue has already been freed.
438 static int __vb2_queue_free(struct vb2_queue
*q
, unsigned int buffers
)
443 * Sanity check: when preparing a buffer the queue lock is released for
444 * a short while (see __buf_prepare for the details), which would allow
445 * a race with a reqbufs which can call this function. Removing the
446 * buffers from underneath __buf_prepare is obviously a bad idea, so we
447 * check if any of the buffers is in the state PREPARING, and if so we
448 * just return -EAGAIN.
450 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
452 if (q
->bufs
[buffer
] == NULL
)
454 if (q
->bufs
[buffer
]->state
== VB2_BUF_STATE_PREPARING
) {
455 dprintk(1, "preparing buffers, cannot free\n");
460 /* Call driver-provided cleanup function for each buffer, if provided */
461 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
463 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
465 if (vb
&& vb
->planes
[0].mem_priv
)
466 call_void_vb_qop(vb
, buf_cleanup
, vb
);
469 /* Release video buffer memory */
470 __vb2_free_mem(q
, buffers
);
472 #ifdef CONFIG_VIDEO_ADV_DEBUG
474 * Check that all the calls were balances during the life-time of this
475 * queue. If not (or if the debug level is 1 or up), then dump the
476 * counters to the kernel log.
478 if (q
->num_buffers
) {
479 bool unbalanced
= q
->cnt_start_streaming
!= q
->cnt_stop_streaming
||
480 q
->cnt_wait_prepare
!= q
->cnt_wait_finish
;
482 if (unbalanced
|| debug
) {
483 pr_info("vb2: counters for queue %p:%s\n", q
,
484 unbalanced
? " UNBALANCED!" : "");
485 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
486 q
->cnt_queue_setup
, q
->cnt_start_streaming
,
487 q
->cnt_stop_streaming
);
488 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
489 q
->cnt_wait_prepare
, q
->cnt_wait_finish
);
491 q
->cnt_queue_setup
= 0;
492 q
->cnt_wait_prepare
= 0;
493 q
->cnt_wait_finish
= 0;
494 q
->cnt_start_streaming
= 0;
495 q
->cnt_stop_streaming
= 0;
497 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
498 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
499 bool unbalanced
= vb
->cnt_mem_alloc
!= vb
->cnt_mem_put
||
500 vb
->cnt_mem_prepare
!= vb
->cnt_mem_finish
||
501 vb
->cnt_mem_get_userptr
!= vb
->cnt_mem_put_userptr
||
502 vb
->cnt_mem_attach_dmabuf
!= vb
->cnt_mem_detach_dmabuf
||
503 vb
->cnt_mem_map_dmabuf
!= vb
->cnt_mem_unmap_dmabuf
||
504 vb
->cnt_buf_queue
!= vb
->cnt_buf_done
||
505 vb
->cnt_buf_prepare
!= vb
->cnt_buf_finish
||
506 vb
->cnt_buf_init
!= vb
->cnt_buf_cleanup
;
508 if (unbalanced
|| debug
) {
509 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
510 q
, buffer
, unbalanced
? " UNBALANCED!" : "");
511 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
512 vb
->cnt_buf_init
, vb
->cnt_buf_cleanup
,
513 vb
->cnt_buf_prepare
, vb
->cnt_buf_finish
);
514 pr_info("vb2: buf_queue: %u buf_done: %u\n",
515 vb
->cnt_buf_queue
, vb
->cnt_buf_done
);
516 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
517 vb
->cnt_mem_alloc
, vb
->cnt_mem_put
,
518 vb
->cnt_mem_prepare
, vb
->cnt_mem_finish
,
520 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
521 vb
->cnt_mem_get_userptr
, vb
->cnt_mem_put_userptr
);
522 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
523 vb
->cnt_mem_attach_dmabuf
, vb
->cnt_mem_detach_dmabuf
,
524 vb
->cnt_mem_map_dmabuf
, vb
->cnt_mem_unmap_dmabuf
);
525 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
526 vb
->cnt_mem_get_dmabuf
,
527 vb
->cnt_mem_num_users
,
534 /* Free videobuf buffers */
535 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
537 kfree(q
->bufs
[buffer
]);
538 q
->bufs
[buffer
] = NULL
;
541 q
->num_buffers
-= buffers
;
542 if (!q
->num_buffers
) {
544 INIT_LIST_HEAD(&q
->queued_list
);
550 * __verify_planes_array() - verify that the planes array passed in struct
551 * v4l2_buffer from userspace can be safely used
553 static int __verify_planes_array(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
555 if (!V4L2_TYPE_IS_MULTIPLANAR(b
->type
))
558 /* Is memory for copying plane information present? */
559 if (NULL
== b
->m
.planes
) {
560 dprintk(1, "multi-planar buffer passed but "
561 "planes array not provided\n");
565 if (b
->length
< vb
->num_planes
|| b
->length
> VIDEO_MAX_PLANES
) {
566 dprintk(1, "incorrect planes array length, "
567 "expected %d, got %d\n", vb
->num_planes
, b
->length
);
575 * __verify_length() - Verify that the bytesused value for each plane fits in
576 * the plane length and that the data offset doesn't exceed the bytesused value.
578 static int __verify_length(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
581 unsigned int bytesused
;
584 if (!V4L2_TYPE_IS_OUTPUT(b
->type
))
587 if (V4L2_TYPE_IS_MULTIPLANAR(b
->type
)) {
588 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
589 length
= (b
->memory
== V4L2_MEMORY_USERPTR
||
590 b
->memory
== V4L2_MEMORY_DMABUF
)
591 ? b
->m
.planes
[plane
].length
592 : vb
->v4l2_planes
[plane
].length
;
593 bytesused
= b
->m
.planes
[plane
].bytesused
594 ? b
->m
.planes
[plane
].bytesused
: length
;
596 if (b
->m
.planes
[plane
].bytesused
> length
)
599 if (b
->m
.planes
[plane
].data_offset
> 0 &&
600 b
->m
.planes
[plane
].data_offset
>= bytesused
)
604 length
= (b
->memory
== V4L2_MEMORY_USERPTR
)
605 ? b
->length
: vb
->v4l2_planes
[0].length
;
606 bytesused
= b
->bytesused
? b
->bytesused
: length
;
608 if (b
->bytesused
> length
)
616 * __buffer_in_use() - return true if the buffer is in use and
617 * the queue cannot be freed (by the means of REQBUFS(0)) call
619 static bool __buffer_in_use(struct vb2_queue
*q
, struct vb2_buffer
*vb
)
622 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
623 void *mem_priv
= vb
->planes
[plane
].mem_priv
;
625 * If num_users() has not been provided, call_memop
626 * will return 0, apparently nobody cares about this
627 * case anyway. If num_users() returns more than 1,
628 * we are not the only user of the plane's memory.
630 if (mem_priv
&& call_memop(vb
, num_users
, mem_priv
) > 1)
637 * __buffers_in_use() - return true if any buffers on the queue are in use and
638 * the queue cannot be freed (by the means of REQBUFS(0)) call
640 static bool __buffers_in_use(struct vb2_queue
*q
)
643 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
644 if (__buffer_in_use(q
, q
->bufs
[buffer
]))
651 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
652 * returned to userspace
654 static void __fill_v4l2_buffer(struct vb2_buffer
*vb
, struct v4l2_buffer
*b
)
656 struct vb2_queue
*q
= vb
->vb2_queue
;
658 /* Copy back data such as timestamp, flags, etc. */
659 memcpy(b
, &vb
->v4l2_buf
, offsetof(struct v4l2_buffer
, m
));
660 b
->reserved2
= vb
->v4l2_buf
.reserved2
;
661 b
->reserved
= vb
->v4l2_buf
.reserved
;
663 if (V4L2_TYPE_IS_MULTIPLANAR(q
->type
)) {
665 * Fill in plane-related data if userspace provided an array
666 * for it. The caller has already verified memory and size.
668 b
->length
= vb
->num_planes
;
669 memcpy(b
->m
.planes
, vb
->v4l2_planes
,
670 b
->length
* sizeof(struct v4l2_plane
));
673 * We use length and offset in v4l2_planes array even for
674 * single-planar buffers, but userspace does not.
676 b
->length
= vb
->v4l2_planes
[0].length
;
677 b
->bytesused
= vb
->v4l2_planes
[0].bytesused
;
678 if (q
->memory
== V4L2_MEMORY_MMAP
)
679 b
->m
.offset
= vb
->v4l2_planes
[0].m
.mem_offset
;
680 else if (q
->memory
== V4L2_MEMORY_USERPTR
)
681 b
->m
.userptr
= vb
->v4l2_planes
[0].m
.userptr
;
682 else if (q
->memory
== V4L2_MEMORY_DMABUF
)
683 b
->m
.fd
= vb
->v4l2_planes
[0].m
.fd
;
687 * Clear any buffer state related flags.
689 b
->flags
&= ~V4L2_BUFFER_MASK_FLAGS
;
690 b
->flags
|= q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
;
691 if ((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) !=
692 V4L2_BUF_FLAG_TIMESTAMP_COPY
) {
694 * For non-COPY timestamps, drop timestamp source bits
695 * and obtain the timestamp source from the queue.
697 b
->flags
&= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
698 b
->flags
|= q
->timestamp_flags
& V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
702 case VB2_BUF_STATE_QUEUED
:
703 case VB2_BUF_STATE_ACTIVE
:
704 b
->flags
|= V4L2_BUF_FLAG_QUEUED
;
706 case VB2_BUF_STATE_ERROR
:
707 b
->flags
|= V4L2_BUF_FLAG_ERROR
;
709 case VB2_BUF_STATE_DONE
:
710 b
->flags
|= V4L2_BUF_FLAG_DONE
;
712 case VB2_BUF_STATE_PREPARED
:
713 b
->flags
|= V4L2_BUF_FLAG_PREPARED
;
715 case VB2_BUF_STATE_PREPARING
:
716 case VB2_BUF_STATE_DEQUEUED
:
721 if (__buffer_in_use(q
, vb
))
722 b
->flags
|= V4L2_BUF_FLAG_MAPPED
;
726 * vb2_querybuf() - query video buffer information
728 * @b: buffer struct passed from userspace to vidioc_querybuf handler
731 * Should be called from vidioc_querybuf ioctl handler in driver.
732 * This function will verify the passed v4l2_buffer structure and fill the
733 * relevant information for the userspace.
735 * The return values from this function are intended to be directly returned
736 * from vidioc_querybuf handler in driver.
738 int vb2_querybuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
740 struct vb2_buffer
*vb
;
743 if (b
->type
!= q
->type
) {
744 dprintk(1, "wrong buffer type\n");
748 if (b
->index
>= q
->num_buffers
) {
749 dprintk(1, "buffer index out of range\n");
752 vb
= q
->bufs
[b
->index
];
753 ret
= __verify_planes_array(vb
, b
);
755 __fill_v4l2_buffer(vb
, b
);
758 EXPORT_SYMBOL(vb2_querybuf
);
761 * __verify_userptr_ops() - verify that all memory operations required for
762 * USERPTR queue type have been provided
764 static int __verify_userptr_ops(struct vb2_queue
*q
)
766 if (!(q
->io_modes
& VB2_USERPTR
) || !q
->mem_ops
->get_userptr
||
767 !q
->mem_ops
->put_userptr
)
774 * __verify_mmap_ops() - verify that all memory operations required for
775 * MMAP queue type have been provided
777 static int __verify_mmap_ops(struct vb2_queue
*q
)
779 if (!(q
->io_modes
& VB2_MMAP
) || !q
->mem_ops
->alloc
||
780 !q
->mem_ops
->put
|| !q
->mem_ops
->mmap
)
787 * __verify_dmabuf_ops() - verify that all memory operations required for
788 * DMABUF queue type have been provided
790 static int __verify_dmabuf_ops(struct vb2_queue
*q
)
792 if (!(q
->io_modes
& VB2_DMABUF
) || !q
->mem_ops
->attach_dmabuf
||
793 !q
->mem_ops
->detach_dmabuf
|| !q
->mem_ops
->map_dmabuf
||
794 !q
->mem_ops
->unmap_dmabuf
)
801 * __verify_memory_type() - Check whether the memory type and buffer type
802 * passed to a buffer operation are compatible with the queue.
804 static int __verify_memory_type(struct vb2_queue
*q
,
805 enum v4l2_memory memory
, enum v4l2_buf_type type
)
807 if (memory
!= V4L2_MEMORY_MMAP
&& memory
!= V4L2_MEMORY_USERPTR
&&
808 memory
!= V4L2_MEMORY_DMABUF
) {
809 dprintk(1, "unsupported memory type\n");
813 if (type
!= q
->type
) {
814 dprintk(1, "requested type is incorrect\n");
819 * Make sure all the required memory ops for given memory type
822 if (memory
== V4L2_MEMORY_MMAP
&& __verify_mmap_ops(q
)) {
823 dprintk(1, "MMAP for current setup unsupported\n");
827 if (memory
== V4L2_MEMORY_USERPTR
&& __verify_userptr_ops(q
)) {
828 dprintk(1, "USERPTR for current setup unsupported\n");
832 if (memory
== V4L2_MEMORY_DMABUF
&& __verify_dmabuf_ops(q
)) {
833 dprintk(1, "DMABUF for current setup unsupported\n");
838 * Place the busy tests at the end: -EBUSY can be ignored when
839 * create_bufs is called with count == 0, but count == 0 should still
840 * do the memory and type validation.
842 if (vb2_fileio_is_active(q
)) {
843 dprintk(1, "file io in progress\n");
850 * __reqbufs() - Initiate streaming
851 * @q: videobuf2 queue
852 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
854 * Should be called from vidioc_reqbufs ioctl handler of a driver.
856 * 1) verifies streaming parameters passed from the userspace,
857 * 2) sets up the queue,
858 * 3) negotiates number of buffers and planes per buffer with the driver
859 * to be used during streaming,
860 * 4) allocates internal buffer structures (struct vb2_buffer), according to
861 * the agreed parameters,
862 * 5) for MMAP memory type, allocates actual video memory, using the
863 * memory handling/allocation routines provided during queue initialization
865 * If req->count is 0, all the memory will be freed instead.
866 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
867 * and the queue is not busy, memory will be reallocated.
869 * The return values from this function are intended to be directly returned
870 * from vidioc_reqbufs handler in driver.
872 static int __reqbufs(struct vb2_queue
*q
, struct v4l2_requestbuffers
*req
)
874 unsigned int num_buffers
, allocated_buffers
, num_planes
= 0;
878 dprintk(1, "streaming active\n");
882 if (req
->count
== 0 || q
->num_buffers
!= 0 || q
->memory
!= req
->memory
) {
884 * We already have buffers allocated, so first check if they
885 * are not in use and can be freed.
887 mutex_lock(&q
->mmap_lock
);
888 if (q
->memory
== V4L2_MEMORY_MMAP
&& __buffers_in_use(q
)) {
889 mutex_unlock(&q
->mmap_lock
);
890 dprintk(1, "memory in use, cannot free\n");
895 * Call queue_cancel to clean up any buffers in the PREPARED or
896 * QUEUED state which is possible if buffers were prepared or
897 * queued without ever calling STREAMON.
899 __vb2_queue_cancel(q
);
900 ret
= __vb2_queue_free(q
, q
->num_buffers
);
901 mutex_unlock(&q
->mmap_lock
);
906 * In case of REQBUFS(0) return immediately without calling
907 * driver's queue_setup() callback and allocating resources.
914 * Make sure the requested values and current defaults are sane.
916 num_buffers
= min_t(unsigned int, req
->count
, VIDEO_MAX_FRAME
);
917 num_buffers
= max_t(unsigned int, num_buffers
, q
->min_buffers_needed
);
918 memset(q
->plane_sizes
, 0, sizeof(q
->plane_sizes
));
919 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
920 q
->memory
= req
->memory
;
923 * Ask the driver how many buffers and planes per buffer it requires.
924 * Driver also sets the size and allocator context for each plane.
926 ret
= call_qop(q
, queue_setup
, q
, NULL
, &num_buffers
, &num_planes
,
927 q
->plane_sizes
, q
->alloc_ctx
);
931 /* Finally, allocate buffers and video memory */
932 allocated_buffers
= __vb2_queue_alloc(q
, req
->memory
, num_buffers
, num_planes
);
933 if (allocated_buffers
== 0) {
934 dprintk(1, "memory allocation failed\n");
939 * There is no point in continuing if we can't allocate the minimum
940 * number of buffers needed by this vb2_queue.
942 if (allocated_buffers
< q
->min_buffers_needed
)
946 * Check if driver can handle the allocated number of buffers.
948 if (!ret
&& allocated_buffers
< num_buffers
) {
949 num_buffers
= allocated_buffers
;
951 ret
= call_qop(q
, queue_setup
, q
, NULL
, &num_buffers
,
952 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
954 if (!ret
&& allocated_buffers
< num_buffers
)
958 * Either the driver has accepted a smaller number of buffers,
959 * or .queue_setup() returned an error
963 mutex_lock(&q
->mmap_lock
);
964 q
->num_buffers
= allocated_buffers
;
968 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
969 * from q->num_buffers.
971 __vb2_queue_free(q
, allocated_buffers
);
972 mutex_unlock(&q
->mmap_lock
);
975 mutex_unlock(&q
->mmap_lock
);
978 * Return the number of successfully allocated buffers
981 req
->count
= allocated_buffers
;
982 q
->waiting_for_buffers
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
988 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
990 * @q: videobuf2 queue
991 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
993 int vb2_reqbufs(struct vb2_queue
*q
, struct v4l2_requestbuffers
*req
)
995 int ret
= __verify_memory_type(q
, req
->memory
, req
->type
);
997 return ret
? ret
: __reqbufs(q
, req
);
999 EXPORT_SYMBOL_GPL(vb2_reqbufs
);
1002 * __create_bufs() - Allocate buffers and any required auxiliary structs
1003 * @q: videobuf2 queue
1004 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1007 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1009 * 1) verifies parameter sanity
1010 * 2) calls the .queue_setup() queue operation
1011 * 3) performs any necessary memory allocations
1013 * The return values from this function are intended to be directly returned
1014 * from vidioc_create_bufs handler in driver.
1016 static int __create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
1018 unsigned int num_planes
= 0, num_buffers
, allocated_buffers
;
1021 if (q
->num_buffers
== VIDEO_MAX_FRAME
) {
1022 dprintk(1, "maximum number of buffers already allocated\n");
1026 if (!q
->num_buffers
) {
1027 memset(q
->plane_sizes
, 0, sizeof(q
->plane_sizes
));
1028 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
1029 q
->memory
= create
->memory
;
1030 q
->waiting_for_buffers
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
1033 num_buffers
= min(create
->count
, VIDEO_MAX_FRAME
- q
->num_buffers
);
1036 * Ask the driver, whether the requested number of buffers, planes per
1037 * buffer and their sizes are acceptable
1039 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
1040 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
1044 /* Finally, allocate buffers and video memory */
1045 allocated_buffers
= __vb2_queue_alloc(q
, create
->memory
, num_buffers
,
1047 if (allocated_buffers
== 0) {
1048 dprintk(1, "memory allocation failed\n");
1053 * Check if driver can handle the so far allocated number of buffers.
1055 if (allocated_buffers
< num_buffers
) {
1056 num_buffers
= allocated_buffers
;
1059 * q->num_buffers contains the total number of buffers, that the
1060 * queue driver has set up
1062 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
1063 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
1065 if (!ret
&& allocated_buffers
< num_buffers
)
1069 * Either the driver has accepted a smaller number of buffers,
1070 * or .queue_setup() returned an error
1074 mutex_lock(&q
->mmap_lock
);
1075 q
->num_buffers
+= allocated_buffers
;
1079 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1080 * from q->num_buffers.
1082 __vb2_queue_free(q
, allocated_buffers
);
1083 mutex_unlock(&q
->mmap_lock
);
1086 mutex_unlock(&q
->mmap_lock
);
1089 * Return the number of successfully allocated buffers
1092 create
->count
= allocated_buffers
;
1098 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1099 * memory and type values.
1100 * @q: videobuf2 queue
1101 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1104 int vb2_create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
1106 int ret
= __verify_memory_type(q
, create
->memory
, create
->format
.type
);
1108 create
->index
= q
->num_buffers
;
1109 if (create
->count
== 0)
1110 return ret
!= -EBUSY
? ret
: 0;
1111 return ret
? ret
: __create_bufs(q
, create
);
1113 EXPORT_SYMBOL_GPL(vb2_create_bufs
);
1116 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1117 * @vb: vb2_buffer to which the plane in question belongs to
1118 * @plane_no: plane number for which the address is to be returned
1120 * This function returns a kernel virtual address of a given plane if
1121 * such a mapping exist, NULL otherwise.
1123 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
)
1125 if (plane_no
> vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
1128 return call_ptr_memop(vb
, vaddr
, vb
->planes
[plane_no
].mem_priv
);
1131 EXPORT_SYMBOL_GPL(vb2_plane_vaddr
);
1134 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1135 * @vb: vb2_buffer to which the plane in question belongs to
1136 * @plane_no: plane number for which the cookie is to be returned
1138 * This function returns an allocator specific cookie for a given plane if
1139 * available, NULL otherwise. The allocator should provide some simple static
1140 * inline function, which would convert this cookie to the allocator specific
1141 * type that can be used directly by the driver to access the buffer. This can
1142 * be for example physical address, pointer to scatter list or IOMMU mapping.
1144 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
)
1146 if (plane_no
>= vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
1149 return call_ptr_memop(vb
, cookie
, vb
->planes
[plane_no
].mem_priv
);
1151 EXPORT_SYMBOL_GPL(vb2_plane_cookie
);
1154 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1155 * @vb: vb2_buffer returned from the driver
1156 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
1157 * or VB2_BUF_STATE_ERROR if the operation finished with an error.
1158 * If start_streaming fails then it should return buffers with state
1159 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1161 * This function should be called by the driver after a hardware operation on
1162 * a buffer is finished and the buffer may be returned to userspace. The driver
1163 * cannot use this buffer anymore until it is queued back to it by videobuf
1164 * by the means of buf_queue callback. Only buffers previously queued to the
1165 * driver by buf_queue can be passed to this function.
1167 * While streaming a buffer can only be returned in state DONE or ERROR.
1168 * The start_streaming op can also return them in case the DMA engine cannot
1169 * be started for some reason. In that case the buffers should be returned with
1172 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
)
1174 struct vb2_queue
*q
= vb
->vb2_queue
;
1175 unsigned long flags
;
1178 if (WARN_ON(vb
->state
!= VB2_BUF_STATE_ACTIVE
))
1181 if (WARN_ON(state
!= VB2_BUF_STATE_DONE
&&
1182 state
!= VB2_BUF_STATE_ERROR
&&
1183 state
!= VB2_BUF_STATE_QUEUED
))
1184 state
= VB2_BUF_STATE_ERROR
;
1186 #ifdef CONFIG_VIDEO_ADV_DEBUG
1188 * Although this is not a callback, it still does have to balance
1189 * with the buf_queue op. So update this counter manually.
1193 dprintk(4, "done processing on buffer %d, state: %d\n",
1194 vb
->v4l2_buf
.index
, state
);
1197 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1198 call_void_memop(vb
, finish
, vb
->planes
[plane
].mem_priv
);
1200 /* Add the buffer to the done buffers list */
1201 spin_lock_irqsave(&q
->done_lock
, flags
);
1203 if (state
!= VB2_BUF_STATE_QUEUED
)
1204 list_add_tail(&vb
->done_entry
, &q
->done_list
);
1205 atomic_dec(&q
->owned_by_drv_count
);
1206 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1208 if (state
== VB2_BUF_STATE_QUEUED
)
1211 /* Inform any processes that may be waiting for buffers */
1212 wake_up(&q
->done_wq
);
1214 EXPORT_SYMBOL_GPL(vb2_buffer_done
);
1217 * vb2_discard_done() - discard all buffers marked as DONE
1218 * @q: videobuf2 queue
1220 * This function is intended to be used with suspend/resume operations. It
1221 * discards all 'done' buffers as they would be too old to be requested after
1224 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1225 * delayed works before calling this function to make sure no buffer will be
1226 * touched by the driver and/or hardware.
1228 void vb2_discard_done(struct vb2_queue
*q
)
1230 struct vb2_buffer
*vb
;
1231 unsigned long flags
;
1233 spin_lock_irqsave(&q
->done_lock
, flags
);
1234 list_for_each_entry(vb
, &q
->done_list
, done_entry
)
1235 vb
->state
= VB2_BUF_STATE_ERROR
;
1236 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1238 EXPORT_SYMBOL_GPL(vb2_discard_done
);
1241 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1242 * v4l2_buffer by the userspace. The caller has already verified that struct
1243 * v4l2_buffer has a valid number of planes.
1245 static void __fill_vb2_buffer(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
,
1246 struct v4l2_plane
*v4l2_planes
)
1250 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1251 if (WARN_ON_ONCE(b
->bytesused
== 0)) {
1252 pr_warn_once("use of bytesused == 0 is deprecated and will be removed in the future,\n");
1253 if (vb
->vb2_queue
->allow_zero_bytesused
)
1254 pr_warn_once("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
1256 pr_warn_once("use the actual size instead.\n");
1260 if (V4L2_TYPE_IS_MULTIPLANAR(b
->type
)) {
1261 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
1262 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1263 v4l2_planes
[plane
].m
.userptr
=
1264 b
->m
.planes
[plane
].m
.userptr
;
1265 v4l2_planes
[plane
].length
=
1266 b
->m
.planes
[plane
].length
;
1269 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
1270 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1271 v4l2_planes
[plane
].m
.fd
=
1272 b
->m
.planes
[plane
].m
.fd
;
1273 v4l2_planes
[plane
].length
=
1274 b
->m
.planes
[plane
].length
;
1278 /* Fill in driver-provided information for OUTPUT types */
1279 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1281 * Will have to go up to b->length when API starts
1282 * accepting variable number of planes.
1284 * If bytesused == 0 for the output buffer, then fall
1285 * back to the full buffer size. In that case
1286 * userspace clearly never bothered to set it and
1287 * it's a safe assumption that they really meant to
1288 * use the full plane sizes.
1290 * Some drivers, e.g. old codec drivers, use bytesused == 0
1291 * as a way to indicate that streaming is finished.
1292 * In that case, the driver should use the
1293 * allow_zero_bytesused flag to keep old userspace
1294 * applications working.
1296 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1297 struct v4l2_plane
*pdst
= &v4l2_planes
[plane
];
1298 struct v4l2_plane
*psrc
= &b
->m
.planes
[plane
];
1300 if (vb
->vb2_queue
->allow_zero_bytesused
)
1301 pdst
->bytesused
= psrc
->bytesused
;
1303 pdst
->bytesused
= psrc
->bytesused
?
1304 psrc
->bytesused
: pdst
->length
;
1305 pdst
->data_offset
= psrc
->data_offset
;
1310 * Single-planar buffers do not use planes array,
1311 * so fill in relevant v4l2_buffer struct fields instead.
1312 * In videobuf we use our internal V4l2_planes struct for
1313 * single-planar buffers as well, for simplicity.
1315 * If bytesused == 0 for the output buffer, then fall back
1316 * to the full buffer size as that's a sensible default.
1318 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
1319 * a way to indicate that streaming is finished. In that case,
1320 * the driver should use the allow_zero_bytesused flag to keep
1321 * old userspace applications working.
1323 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
1324 v4l2_planes
[0].m
.userptr
= b
->m
.userptr
;
1325 v4l2_planes
[0].length
= b
->length
;
1328 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
1329 v4l2_planes
[0].m
.fd
= b
->m
.fd
;
1330 v4l2_planes
[0].length
= b
->length
;
1333 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1334 if (vb
->vb2_queue
->allow_zero_bytesused
)
1335 v4l2_planes
[0].bytesused
= b
->bytesused
;
1337 v4l2_planes
[0].bytesused
= b
->bytesused
?
1338 b
->bytesused
: v4l2_planes
[0].length
;
1340 v4l2_planes
[0].bytesused
= 0;
1344 /* Zero flags that the vb2 core handles */
1345 vb
->v4l2_buf
.flags
= b
->flags
& ~V4L2_BUFFER_MASK_FLAGS
;
1346 if ((vb
->vb2_queue
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) !=
1347 V4L2_BUF_FLAG_TIMESTAMP_COPY
|| !V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1349 * Non-COPY timestamps and non-OUTPUT queues will get
1350 * their timestamp and timestamp source flags from the
1353 vb
->v4l2_buf
.flags
&= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
1356 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1358 * For output buffers mask out the timecode flag:
1359 * this will be handled later in vb2_internal_qbuf().
1360 * The 'field' is valid metadata for this output buffer
1361 * and so that needs to be copied here.
1363 vb
->v4l2_buf
.flags
&= ~V4L2_BUF_FLAG_TIMECODE
;
1364 vb
->v4l2_buf
.field
= b
->field
;
1366 /* Zero any output buffer flags as this is a capture buffer */
1367 vb
->v4l2_buf
.flags
&= ~V4L2_BUFFER_OUT_FLAGS
;
1372 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1374 static int __qbuf_mmap(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1376 __fill_vb2_buffer(vb
, b
, vb
->v4l2_planes
);
1377 return call_vb_qop(vb
, buf_prepare
, vb
);
1381 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1383 static int __qbuf_userptr(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1385 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1386 struct vb2_queue
*q
= vb
->vb2_queue
;
1390 enum dma_data_direction dma_dir
=
1391 V4L2_TYPE_IS_OUTPUT(q
->type
) ? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1392 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1394 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1395 /* Copy relevant information provided by the userspace */
1396 __fill_vb2_buffer(vb
, b
, planes
);
1398 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1399 /* Skip the plane if already verified */
1400 if (vb
->v4l2_planes
[plane
].m
.userptr
&&
1401 vb
->v4l2_planes
[plane
].m
.userptr
== planes
[plane
].m
.userptr
1402 && vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
)
1405 dprintk(3, "userspace address for plane %d changed, "
1406 "reacquiring memory\n", plane
);
1408 /* Check if the provided plane buffer is large enough */
1409 if (planes
[plane
].length
< q
->plane_sizes
[plane
]) {
1410 dprintk(1, "provided buffer size %u is less than "
1411 "setup size %u for plane %d\n",
1412 planes
[plane
].length
,
1413 q
->plane_sizes
[plane
], plane
);
1418 /* Release previously acquired memory if present */
1419 if (vb
->planes
[plane
].mem_priv
) {
1422 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1424 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1427 vb
->planes
[plane
].mem_priv
= NULL
;
1428 memset(&vb
->v4l2_planes
[plane
], 0, sizeof(struct v4l2_plane
));
1430 /* Acquire each plane's memory */
1431 mem_priv
= call_ptr_memop(vb
, get_userptr
, q
->alloc_ctx
[plane
],
1432 planes
[plane
].m
.userptr
,
1433 planes
[plane
].length
, dma_dir
);
1434 if (IS_ERR_OR_NULL(mem_priv
)) {
1435 dprintk(1, "failed acquiring userspace "
1436 "memory for plane %d\n", plane
);
1437 ret
= mem_priv
? PTR_ERR(mem_priv
) : -EINVAL
;
1440 vb
->planes
[plane
].mem_priv
= mem_priv
;
1444 * Now that everything is in order, copy relevant information
1445 * provided by userspace.
1447 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1448 vb
->v4l2_planes
[plane
] = planes
[plane
];
1452 * One or more planes changed, so we must call buf_init to do
1453 * the driver-specific initialization on the newly acquired
1454 * buffer, if provided.
1456 ret
= call_vb_qop(vb
, buf_init
, vb
);
1458 dprintk(1, "buffer initialization failed\n");
1463 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1465 dprintk(1, "buffer preparation failed\n");
1466 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1472 /* In case of errors, release planes that were already acquired */
1473 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1474 if (vb
->planes
[plane
].mem_priv
)
1475 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1476 vb
->planes
[plane
].mem_priv
= NULL
;
1477 vb
->v4l2_planes
[plane
].m
.userptr
= 0;
1478 vb
->v4l2_planes
[plane
].length
= 0;
1485 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1487 static int __qbuf_dmabuf(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1489 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1490 struct vb2_queue
*q
= vb
->vb2_queue
;
1494 enum dma_data_direction dma_dir
=
1495 V4L2_TYPE_IS_OUTPUT(q
->type
) ? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1496 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1498 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1499 /* Copy relevant information provided by the userspace */
1500 __fill_vb2_buffer(vb
, b
, planes
);
1502 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1503 struct dma_buf
*dbuf
= dma_buf_get(planes
[plane
].m
.fd
);
1505 if (IS_ERR_OR_NULL(dbuf
)) {
1506 dprintk(1, "invalid dmabuf fd for plane %d\n",
1512 /* use DMABUF size if length is not provided */
1513 if (planes
[plane
].length
== 0)
1514 planes
[plane
].length
= dbuf
->size
;
1516 if (planes
[plane
].length
< q
->plane_sizes
[plane
]) {
1517 dprintk(1, "invalid dmabuf length for plane %d\n",
1523 /* Skip the plane if already verified */
1524 if (dbuf
== vb
->planes
[plane
].dbuf
&&
1525 vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
) {
1530 dprintk(1, "buffer for plane %d changed\n", plane
);
1534 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1537 /* Release previously acquired memory if present */
1538 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
1539 memset(&vb
->v4l2_planes
[plane
], 0, sizeof(struct v4l2_plane
));
1541 /* Acquire each plane's memory */
1542 mem_priv
= call_ptr_memop(vb
, attach_dmabuf
, q
->alloc_ctx
[plane
],
1543 dbuf
, planes
[plane
].length
, dma_dir
);
1544 if (IS_ERR(mem_priv
)) {
1545 dprintk(1, "failed to attach dmabuf\n");
1546 ret
= PTR_ERR(mem_priv
);
1551 vb
->planes
[plane
].dbuf
= dbuf
;
1552 vb
->planes
[plane
].mem_priv
= mem_priv
;
1555 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1556 * really we want to do this just before the DMA, not while queueing
1559 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1560 ret
= call_memop(vb
, map_dmabuf
, vb
->planes
[plane
].mem_priv
);
1562 dprintk(1, "failed to map dmabuf for plane %d\n",
1566 vb
->planes
[plane
].dbuf_mapped
= 1;
1570 * Now that everything is in order, copy relevant information
1571 * provided by userspace.
1573 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1574 vb
->v4l2_planes
[plane
] = planes
[plane
];
1578 * Call driver-specific initialization on the newly acquired buffer,
1581 ret
= call_vb_qop(vb
, buf_init
, vb
);
1583 dprintk(1, "buffer initialization failed\n");
1588 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1590 dprintk(1, "buffer preparation failed\n");
1591 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1597 /* In case of errors, release planes that were already acquired */
1598 __vb2_buf_dmabuf_put(vb
);
1604 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1606 static void __enqueue_in_driver(struct vb2_buffer
*vb
)
1608 struct vb2_queue
*q
= vb
->vb2_queue
;
1611 vb
->state
= VB2_BUF_STATE_ACTIVE
;
1612 atomic_inc(&q
->owned_by_drv_count
);
1615 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1616 call_void_memop(vb
, prepare
, vb
->planes
[plane
].mem_priv
);
1618 call_void_vb_qop(vb
, buf_queue
, vb
);
1621 static int __buf_prepare(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1623 struct vb2_queue
*q
= vb
->vb2_queue
;
1626 ret
= __verify_length(vb
, b
);
1628 dprintk(1, "plane parameters verification failed: %d\n", ret
);
1631 if (b
->field
== V4L2_FIELD_ALTERNATE
&& V4L2_TYPE_IS_OUTPUT(q
->type
)) {
1633 * If the format's field is ALTERNATE, then the buffer's field
1634 * should be either TOP or BOTTOM, not ALTERNATE since that
1635 * makes no sense. The driver has to know whether the
1636 * buffer represents a top or a bottom field in order to
1637 * program any DMA correctly. Using ALTERNATE is wrong, since
1638 * that just says that it is either a top or a bottom field,
1639 * but not which of the two it is.
1641 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1646 dprintk(1, "fatal error occurred on queue\n");
1650 vb
->state
= VB2_BUF_STATE_PREPARING
;
1651 vb
->v4l2_buf
.timestamp
.tv_sec
= 0;
1652 vb
->v4l2_buf
.timestamp
.tv_usec
= 0;
1653 vb
->v4l2_buf
.sequence
= 0;
1655 switch (q
->memory
) {
1656 case V4L2_MEMORY_MMAP
:
1657 ret
= __qbuf_mmap(vb
, b
);
1659 case V4L2_MEMORY_USERPTR
:
1660 ret
= __qbuf_userptr(vb
, b
);
1662 case V4L2_MEMORY_DMABUF
:
1663 ret
= __qbuf_dmabuf(vb
, b
);
1666 WARN(1, "Invalid queue type\n");
1671 dprintk(1, "buffer preparation failed: %d\n", ret
);
1672 vb
->state
= ret
? VB2_BUF_STATE_DEQUEUED
: VB2_BUF_STATE_PREPARED
;
1677 static int vb2_queue_or_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
,
1680 if (b
->type
!= q
->type
) {
1681 dprintk(1, "%s: invalid buffer type\n", opname
);
1685 if (b
->index
>= q
->num_buffers
) {
1686 dprintk(1, "%s: buffer index out of range\n", opname
);
1690 if (q
->bufs
[b
->index
] == NULL
) {
1691 /* Should never happen */
1692 dprintk(1, "%s: buffer is NULL\n", opname
);
1696 if (b
->memory
!= q
->memory
) {
1697 dprintk(1, "%s: invalid memory type\n", opname
);
1701 return __verify_planes_array(q
->bufs
[b
->index
], b
);
1705 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1706 * @q: videobuf2 queue
1707 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1710 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1712 * 1) verifies the passed buffer,
1713 * 2) calls buf_prepare callback in the driver (if provided), in which
1714 * driver-specific buffer initialization can be performed,
1716 * The return values from this function are intended to be directly returned
1717 * from vidioc_prepare_buf handler in driver.
1719 int vb2_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1721 struct vb2_buffer
*vb
;
1724 if (vb2_fileio_is_active(q
)) {
1725 dprintk(1, "file io in progress\n");
1729 ret
= vb2_queue_or_prepare_buf(q
, b
, "prepare_buf");
1733 vb
= q
->bufs
[b
->index
];
1734 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1735 dprintk(1, "invalid buffer state %d\n",
1740 ret
= __buf_prepare(vb
, b
);
1742 /* Fill buffer information for the userspace */
1743 __fill_v4l2_buffer(vb
, b
);
1745 dprintk(1, "prepare of buffer %d succeeded\n", vb
->v4l2_buf
.index
);
1749 EXPORT_SYMBOL_GPL(vb2_prepare_buf
);
1752 * vb2_start_streaming() - Attempt to start streaming.
1753 * @q: videobuf2 queue
1755 * Attempt to start streaming. When this function is called there must be
1756 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1757 * number of buffers required for the DMA engine to function). If the
1758 * @start_streaming op fails it is supposed to return all the driver-owned
1759 * buffers back to vb2 in state QUEUED. Check if that happened and if
1760 * not warn and reclaim them forcefully.
1762 static int vb2_start_streaming(struct vb2_queue
*q
)
1764 struct vb2_buffer
*vb
;
1768 * If any buffers were queued before streamon,
1769 * we can now pass them to driver for processing.
1771 list_for_each_entry(vb
, &q
->queued_list
, queued_entry
)
1772 __enqueue_in_driver(vb
);
1774 /* Tell the driver to start streaming */
1775 q
->start_streaming_called
= 1;
1776 ret
= call_qop(q
, start_streaming
, q
,
1777 atomic_read(&q
->owned_by_drv_count
));
1781 q
->start_streaming_called
= 0;
1783 dprintk(1, "driver refused to start streaming\n");
1785 * If you see this warning, then the driver isn't cleaning up properly
1786 * after a failed start_streaming(). See the start_streaming()
1787 * documentation in videobuf2-core.h for more information how buffers
1788 * should be returned to vb2 in start_streaming().
1790 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1794 * Forcefully reclaim buffers if the driver did not
1795 * correctly return them to vb2.
1797 for (i
= 0; i
< q
->num_buffers
; ++i
) {
1799 if (vb
->state
== VB2_BUF_STATE_ACTIVE
)
1800 vb2_buffer_done(vb
, VB2_BUF_STATE_QUEUED
);
1802 /* Must be zero now */
1803 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1806 * If done_list is not empty, then start_streaming() didn't call
1807 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1810 WARN_ON(!list_empty(&q
->done_list
));
1814 static int vb2_internal_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1816 int ret
= vb2_queue_or_prepare_buf(q
, b
, "qbuf");
1817 struct vb2_buffer
*vb
;
1822 vb
= q
->bufs
[b
->index
];
1824 switch (vb
->state
) {
1825 case VB2_BUF_STATE_DEQUEUED
:
1826 ret
= __buf_prepare(vb
, b
);
1830 case VB2_BUF_STATE_PREPARED
:
1832 case VB2_BUF_STATE_PREPARING
:
1833 dprintk(1, "buffer still being prepared\n");
1836 dprintk(1, "invalid buffer state %d\n", vb
->state
);
1841 * Add to the queued buffers list, a buffer will stay on it until
1842 * dequeued in dqbuf.
1844 list_add_tail(&vb
->queued_entry
, &q
->queued_list
);
1846 q
->waiting_for_buffers
= false;
1847 vb
->state
= VB2_BUF_STATE_QUEUED
;
1848 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
1850 * For output buffers copy the timestamp if needed,
1851 * and the timecode field and flag if needed.
1853 if ((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
1854 V4L2_BUF_FLAG_TIMESTAMP_COPY
)
1855 vb
->v4l2_buf
.timestamp
= b
->timestamp
;
1856 vb
->v4l2_buf
.flags
|= b
->flags
& V4L2_BUF_FLAG_TIMECODE
;
1857 if (b
->flags
& V4L2_BUF_FLAG_TIMECODE
)
1858 vb
->v4l2_buf
.timecode
= b
->timecode
;
1862 * If already streaming, give the buffer to driver for processing.
1863 * If not, the buffer will be given to driver on next streamon.
1865 if (q
->start_streaming_called
)
1866 __enqueue_in_driver(vb
);
1868 /* Fill buffer information for the userspace */
1869 __fill_v4l2_buffer(vb
, b
);
1872 * If streamon has been called, and we haven't yet called
1873 * start_streaming() since not enough buffers were queued, and
1874 * we now have reached the minimum number of queued buffers,
1875 * then we can finally call start_streaming().
1877 if (q
->streaming
&& !q
->start_streaming_called
&&
1878 q
->queued_count
>= q
->min_buffers_needed
) {
1879 ret
= vb2_start_streaming(q
);
1884 dprintk(1, "qbuf of buffer %d succeeded\n", vb
->v4l2_buf
.index
);
1889 * vb2_qbuf() - Queue a buffer from userspace
1890 * @q: videobuf2 queue
1891 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1894 * Should be called from vidioc_qbuf ioctl handler of a driver.
1896 * 1) verifies the passed buffer,
1897 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1898 * which driver-specific buffer initialization can be performed,
1899 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1900 * callback for processing.
1902 * The return values from this function are intended to be directly returned
1903 * from vidioc_qbuf handler in driver.
1905 int vb2_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1907 if (vb2_fileio_is_active(q
)) {
1908 dprintk(1, "file io in progress\n");
1912 return vb2_internal_qbuf(q
, b
);
1914 EXPORT_SYMBOL_GPL(vb2_qbuf
);
1917 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1920 * Will sleep if required for nonblocking == false.
1922 static int __vb2_wait_for_done_vb(struct vb2_queue
*q
, int nonblocking
)
1925 * All operations on vb_done_list are performed under done_lock
1926 * spinlock protection. However, buffers may be removed from
1927 * it and returned to userspace only while holding both driver's
1928 * lock and the done_lock spinlock. Thus we can be sure that as
1929 * long as we hold the driver's lock, the list will remain not
1930 * empty if list_empty() check succeeds.
1936 if (!q
->streaming
) {
1937 dprintk(1, "streaming off, will not wait for buffers\n");
1942 dprintk(1, "Queue in error state, will not wait for buffers\n");
1946 if (q
->last_buffer_dequeued
) {
1947 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1951 if (!list_empty(&q
->done_list
)) {
1953 * Found a buffer that we were waiting for.
1959 dprintk(1, "nonblocking and no buffers to dequeue, "
1965 * We are streaming and blocking, wait for another buffer to
1966 * become ready or for streamoff. Driver's lock is released to
1967 * allow streamoff or qbuf to be called while waiting.
1969 call_void_qop(q
, wait_prepare
, q
);
1972 * All locks have been released, it is safe to sleep now.
1974 dprintk(3, "will sleep waiting for buffers\n");
1975 ret
= wait_event_interruptible(q
->done_wq
,
1976 !list_empty(&q
->done_list
) || !q
->streaming
||
1980 * We need to reevaluate both conditions again after reacquiring
1981 * the locks or return an error if one occurred.
1983 call_void_qop(q
, wait_finish
, q
);
1985 dprintk(1, "sleep was interrupted\n");
1993 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1995 * Will sleep if required for nonblocking == false.
1997 static int __vb2_get_done_vb(struct vb2_queue
*q
, struct vb2_buffer
**vb
,
1998 struct v4l2_buffer
*b
, int nonblocking
)
2000 unsigned long flags
;
2004 * Wait for at least one buffer to become available on the done_list.
2006 ret
= __vb2_wait_for_done_vb(q
, nonblocking
);
2011 * Driver's lock has been held since we last verified that done_list
2012 * is not empty, so no need for another list_empty(done_list) check.
2014 spin_lock_irqsave(&q
->done_lock
, flags
);
2015 *vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
, done_entry
);
2017 * Only remove the buffer from done_list if v4l2_buffer can handle all
2020 ret
= __verify_planes_array(*vb
, b
);
2022 list_del(&(*vb
)->done_entry
);
2023 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2029 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
2030 * @q: videobuf2 queue
2032 * This function will wait until all buffers that have been given to the driver
2033 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
2034 * wait_prepare, wait_finish pair. It is intended to be called with all locks
2035 * taken, for example from stop_streaming() callback.
2037 int vb2_wait_for_all_buffers(struct vb2_queue
*q
)
2039 if (!q
->streaming
) {
2040 dprintk(1, "streaming off, will not wait for buffers\n");
2044 if (q
->start_streaming_called
)
2045 wait_event(q
->done_wq
, !atomic_read(&q
->owned_by_drv_count
));
2048 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers
);
2051 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2053 static void __vb2_dqbuf(struct vb2_buffer
*vb
)
2055 struct vb2_queue
*q
= vb
->vb2_queue
;
2058 /* nothing to do if the buffer is already dequeued */
2059 if (vb
->state
== VB2_BUF_STATE_DEQUEUED
)
2062 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
2064 /* unmap DMABUF buffer */
2065 if (q
->memory
== V4L2_MEMORY_DMABUF
)
2066 for (i
= 0; i
< vb
->num_planes
; ++i
) {
2067 if (!vb
->planes
[i
].dbuf_mapped
)
2069 call_void_memop(vb
, unmap_dmabuf
, vb
->planes
[i
].mem_priv
);
2070 vb
->planes
[i
].dbuf_mapped
= 0;
2074 static int vb2_internal_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
2076 struct vb2_buffer
*vb
= NULL
;
2079 if (b
->type
!= q
->type
) {
2080 dprintk(1, "invalid buffer type\n");
2083 ret
= __vb2_get_done_vb(q
, &vb
, b
, nonblocking
);
2087 switch (vb
->state
) {
2088 case VB2_BUF_STATE_DONE
:
2089 dprintk(3, "returning done buffer\n");
2091 case VB2_BUF_STATE_ERROR
:
2092 dprintk(3, "returning done buffer with errors\n");
2095 dprintk(1, "invalid buffer state\n");
2099 call_void_vb_qop(vb
, buf_finish
, vb
);
2101 /* Fill buffer information for the userspace */
2102 __fill_v4l2_buffer(vb
, b
);
2103 /* Remove from videobuf queue */
2104 list_del(&vb
->queued_entry
);
2106 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) &&
2107 vb
->v4l2_buf
.flags
& V4L2_BUF_FLAG_LAST
)
2108 q
->last_buffer_dequeued
= true;
2109 /* go back to dequeued state */
2112 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2113 vb
->v4l2_buf
.index
, vb
->state
);
2119 * vb2_dqbuf() - Dequeue a buffer to the userspace
2120 * @q: videobuf2 queue
2121 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2123 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2124 * buffers ready for dequeuing are present. Normally the driver
2125 * would be passing (file->f_flags & O_NONBLOCK) here
2127 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2129 * 1) verifies the passed buffer,
2130 * 2) calls buf_finish callback in the driver (if provided), in which
2131 * driver can perform any additional operations that may be required before
2132 * returning the buffer to userspace, such as cache sync,
2133 * 3) the buffer struct members are filled with relevant information for
2136 * The return values from this function are intended to be directly returned
2137 * from vidioc_dqbuf handler in driver.
2139 int vb2_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
2141 if (vb2_fileio_is_active(q
)) {
2142 dprintk(1, "file io in progress\n");
2145 return vb2_internal_dqbuf(q
, b
, nonblocking
);
2147 EXPORT_SYMBOL_GPL(vb2_dqbuf
);
2150 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2152 * Removes all queued buffers from driver's queue and all buffers queued by
2153 * userspace from videobuf's queue. Returns to state after reqbufs.
2155 static void __vb2_queue_cancel(struct vb2_queue
*q
)
2160 * Tell driver to stop all transactions and release all queued
2163 if (q
->start_streaming_called
)
2164 call_void_qop(q
, stop_streaming
, q
);
2167 * If you see this warning, then the driver isn't cleaning up properly
2168 * in stop_streaming(). See the stop_streaming() documentation in
2169 * videobuf2-core.h for more information how buffers should be returned
2170 * to vb2 in stop_streaming().
2172 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
2173 for (i
= 0; i
< q
->num_buffers
; ++i
)
2174 if (q
->bufs
[i
]->state
== VB2_BUF_STATE_ACTIVE
)
2175 vb2_buffer_done(q
->bufs
[i
], VB2_BUF_STATE_ERROR
);
2176 /* Must be zero now */
2177 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
2181 q
->start_streaming_called
= 0;
2182 q
->queued_count
= 0;
2186 * Remove all buffers from videobuf's list...
2188 INIT_LIST_HEAD(&q
->queued_list
);
2190 * ...and done list; userspace will not receive any buffers it
2191 * has not already dequeued before initiating cancel.
2193 INIT_LIST_HEAD(&q
->done_list
);
2194 atomic_set(&q
->owned_by_drv_count
, 0);
2195 wake_up_all(&q
->done_wq
);
2198 * Reinitialize all buffers for next use.
2199 * Make sure to call buf_finish for any queued buffers. Normally
2200 * that's done in dqbuf, but that's not going to happen when we
2201 * cancel the whole queue. Note: this code belongs here, not in
2202 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2203 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2204 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2206 for (i
= 0; i
< q
->num_buffers
; ++i
) {
2207 struct vb2_buffer
*vb
= q
->bufs
[i
];
2209 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
2210 vb
->state
= VB2_BUF_STATE_PREPARED
;
2211 call_void_vb_qop(vb
, buf_finish
, vb
);
2217 static int vb2_internal_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2221 if (type
!= q
->type
) {
2222 dprintk(1, "invalid stream type\n");
2227 dprintk(3, "already streaming\n");
2231 if (!q
->num_buffers
) {
2232 dprintk(1, "no buffers have been allocated\n");
2236 if (q
->num_buffers
< q
->min_buffers_needed
) {
2237 dprintk(1, "need at least %u allocated buffers\n",
2238 q
->min_buffers_needed
);
2243 * Tell driver to start streaming provided sufficient buffers
2246 if (q
->queued_count
>= q
->min_buffers_needed
) {
2247 ret
= vb2_start_streaming(q
);
2249 __vb2_queue_cancel(q
);
2256 dprintk(3, "successful\n");
2261 * vb2_queue_error() - signal a fatal error on the queue
2262 * @q: videobuf2 queue
2264 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2265 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2266 * buffers will return -EIO.
2268 * The error flag will be cleared when cancelling the queue, either from
2269 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2270 * function before starting the stream, otherwise the error flag will remain set
2271 * until the queue is released when closing the device node.
2273 void vb2_queue_error(struct vb2_queue
*q
)
2277 wake_up_all(&q
->done_wq
);
2279 EXPORT_SYMBOL_GPL(vb2_queue_error
);
2282 * vb2_streamon - start streaming
2283 * @q: videobuf2 queue
2284 * @type: type argument passed from userspace to vidioc_streamon handler
2286 * Should be called from vidioc_streamon handler of a driver.
2288 * 1) verifies current state
2289 * 2) passes any previously queued buffers to the driver and starts streaming
2291 * The return values from this function are intended to be directly returned
2292 * from vidioc_streamon handler in the driver.
2294 int vb2_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2296 if (vb2_fileio_is_active(q
)) {
2297 dprintk(1, "file io in progress\n");
2300 return vb2_internal_streamon(q
, type
);
2302 EXPORT_SYMBOL_GPL(vb2_streamon
);
2304 static int vb2_internal_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2306 if (type
!= q
->type
) {
2307 dprintk(1, "invalid stream type\n");
2312 * Cancel will pause streaming and remove all buffers from the driver
2313 * and videobuf, effectively returning control over them to userspace.
2315 * Note that we do this even if q->streaming == 0: if you prepare or
2316 * queue buffers, and then call streamoff without ever having called
2317 * streamon, you would still expect those buffers to be returned to
2318 * their normal dequeued state.
2320 __vb2_queue_cancel(q
);
2321 q
->waiting_for_buffers
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
2322 q
->last_buffer_dequeued
= false;
2324 dprintk(3, "successful\n");
2329 * vb2_streamoff - stop streaming
2330 * @q: videobuf2 queue
2331 * @type: type argument passed from userspace to vidioc_streamoff handler
2333 * Should be called from vidioc_streamoff handler of a driver.
2335 * 1) verifies current state,
2336 * 2) stop streaming and dequeues any queued buffers, including those previously
2337 * passed to the driver (after waiting for the driver to finish).
2339 * This call can be used for pausing playback.
2340 * The return values from this function are intended to be directly returned
2341 * from vidioc_streamoff handler in the driver
2343 int vb2_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2345 if (vb2_fileio_is_active(q
)) {
2346 dprintk(1, "file io in progress\n");
2349 return vb2_internal_streamoff(q
, type
);
2351 EXPORT_SYMBOL_GPL(vb2_streamoff
);
2354 * __find_plane_by_offset() - find plane associated with the given offset off
2356 static int __find_plane_by_offset(struct vb2_queue
*q
, unsigned long off
,
2357 unsigned int *_buffer
, unsigned int *_plane
)
2359 struct vb2_buffer
*vb
;
2360 unsigned int buffer
, plane
;
2363 * Go over all buffers and their planes, comparing the given offset
2364 * with an offset assigned to each plane. If a match is found,
2365 * return its buffer and plane numbers.
2367 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
2368 vb
= q
->bufs
[buffer
];
2370 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
2371 if (vb
->v4l2_planes
[plane
].m
.mem_offset
== off
) {
2383 * vb2_expbuf() - Export a buffer as a file descriptor
2384 * @q: videobuf2 queue
2385 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2388 * The return values from this function are intended to be directly returned
2389 * from vidioc_expbuf handler in driver.
2391 int vb2_expbuf(struct vb2_queue
*q
, struct v4l2_exportbuffer
*eb
)
2393 struct vb2_buffer
*vb
= NULL
;
2394 struct vb2_plane
*vb_plane
;
2396 struct dma_buf
*dbuf
;
2398 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2399 dprintk(1, "queue is not currently set up for mmap\n");
2403 if (!q
->mem_ops
->get_dmabuf
) {
2404 dprintk(1, "queue does not support DMA buffer exporting\n");
2408 if (eb
->flags
& ~(O_CLOEXEC
| O_ACCMODE
)) {
2409 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2413 if (eb
->type
!= q
->type
) {
2414 dprintk(1, "invalid buffer type\n");
2418 if (eb
->index
>= q
->num_buffers
) {
2419 dprintk(1, "buffer index out of range\n");
2423 vb
= q
->bufs
[eb
->index
];
2425 if (eb
->plane
>= vb
->num_planes
) {
2426 dprintk(1, "buffer plane out of range\n");
2430 if (vb2_fileio_is_active(q
)) {
2431 dprintk(1, "expbuf: file io in progress\n");
2435 vb_plane
= &vb
->planes
[eb
->plane
];
2437 dbuf
= call_ptr_memop(vb
, get_dmabuf
, vb_plane
->mem_priv
, eb
->flags
& O_ACCMODE
);
2438 if (IS_ERR_OR_NULL(dbuf
)) {
2439 dprintk(1, "failed to export buffer %d, plane %d\n",
2440 eb
->index
, eb
->plane
);
2444 ret
= dma_buf_fd(dbuf
, eb
->flags
& ~O_ACCMODE
);
2446 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2447 eb
->index
, eb
->plane
, ret
);
2452 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2453 eb
->index
, eb
->plane
, ret
);
2458 EXPORT_SYMBOL_GPL(vb2_expbuf
);
2461 * vb2_mmap() - map video buffers into application address space
2462 * @q: videobuf2 queue
2463 * @vma: vma passed to the mmap file operation handler in the driver
2465 * Should be called from mmap file operation handler of a driver.
2466 * This function maps one plane of one of the available video buffers to
2467 * userspace. To map whole video memory allocated on reqbufs, this function
2468 * has to be called once per each plane per each buffer previously allocated.
2470 * When the userspace application calls mmap, it passes to it an offset returned
2471 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2472 * a "cookie", which is then used to identify the plane to be mapped.
2473 * This function finds a plane with a matching offset and a mapping is performed
2474 * by the means of a provided memory operation.
2476 * The return values from this function are intended to be directly returned
2477 * from the mmap handler in driver.
2479 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
)
2481 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
2482 struct vb2_buffer
*vb
;
2483 unsigned int buffer
= 0, plane
= 0;
2485 unsigned long length
;
2487 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2488 dprintk(1, "queue is not currently set up for mmap\n");
2493 * Check memory area access mode.
2495 if (!(vma
->vm_flags
& VM_SHARED
)) {
2496 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2499 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
2500 if (!(vma
->vm_flags
& VM_WRITE
)) {
2501 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2505 if (!(vma
->vm_flags
& VM_READ
)) {
2506 dprintk(1, "invalid vma flags, VM_READ needed\n");
2510 if (vb2_fileio_is_active(q
)) {
2511 dprintk(1, "mmap: file io in progress\n");
2516 * Find the plane corresponding to the offset passed by userspace.
2518 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2522 vb
= q
->bufs
[buffer
];
2525 * MMAP requires page_aligned buffers.
2526 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2527 * so, we need to do the same here.
2529 length
= PAGE_ALIGN(vb
->v4l2_planes
[plane
].length
);
2530 if (length
< (vma
->vm_end
- vma
->vm_start
)) {
2532 "MMAP invalid, as it would overflow buffer length\n");
2536 mutex_lock(&q
->mmap_lock
);
2537 ret
= call_memop(vb
, mmap
, vb
->planes
[plane
].mem_priv
, vma
);
2538 mutex_unlock(&q
->mmap_lock
);
2542 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer
, plane
);
2545 EXPORT_SYMBOL_GPL(vb2_mmap
);
2548 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
2551 unsigned long pgoff
,
2552 unsigned long flags
)
2554 unsigned long off
= pgoff
<< PAGE_SHIFT
;
2555 struct vb2_buffer
*vb
;
2556 unsigned int buffer
, plane
;
2560 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2561 dprintk(1, "queue is not currently set up for mmap\n");
2566 * Find the plane corresponding to the offset passed by userspace.
2568 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2572 vb
= q
->bufs
[buffer
];
2574 vaddr
= vb2_plane_vaddr(vb
, plane
);
2575 return vaddr
? (unsigned long)vaddr
: -EINVAL
;
2577 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area
);
2580 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
);
2581 static int __vb2_cleanup_fileio(struct vb2_queue
*q
);
2584 * vb2_poll() - implements poll userspace operation
2585 * @q: videobuf2 queue
2586 * @file: file argument passed to the poll file operation handler
2587 * @wait: wait argument passed to the poll file operation handler
2589 * This function implements poll file operation handler for a driver.
2590 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2591 * be informed that the file descriptor of a video device is available for
2593 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2594 * will be reported as available for writing.
2596 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2599 * The return values from this function are intended to be directly returned
2600 * from poll handler in driver.
2602 unsigned int vb2_poll(struct vb2_queue
*q
, struct file
*file
, poll_table
*wait
)
2604 struct video_device
*vfd
= video_devdata(file
);
2605 unsigned long req_events
= poll_requested_events(wait
);
2606 struct vb2_buffer
*vb
= NULL
;
2607 unsigned int res
= 0;
2608 unsigned long flags
;
2610 if (test_bit(V4L2_FL_USES_V4L2_FH
, &vfd
->flags
)) {
2611 struct v4l2_fh
*fh
= file
->private_data
;
2613 if (v4l2_event_pending(fh
))
2615 else if (req_events
& POLLPRI
)
2616 poll_wait(file
, &fh
->wait
, wait
);
2619 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLIN
| POLLRDNORM
)))
2621 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLOUT
| POLLWRNORM
)))
2625 * Start file I/O emulator only if streaming API has not been used yet.
2627 if (q
->num_buffers
== 0 && !vb2_fileio_is_active(q
)) {
2628 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_READ
) &&
2629 (req_events
& (POLLIN
| POLLRDNORM
))) {
2630 if (__vb2_init_fileio(q
, 1))
2631 return res
| POLLERR
;
2633 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_WRITE
) &&
2634 (req_events
& (POLLOUT
| POLLWRNORM
))) {
2635 if (__vb2_init_fileio(q
, 0))
2636 return res
| POLLERR
;
2638 * Write to OUTPUT queue can be done immediately.
2640 return res
| POLLOUT
| POLLWRNORM
;
2645 * There is nothing to wait for if the queue isn't streaming, or if the
2646 * error flag is set.
2648 if (!vb2_is_streaming(q
) || q
->error
)
2649 return res
| POLLERR
;
2651 * For compatibility with vb1: if QBUF hasn't been called yet, then
2652 * return POLLERR as well. This only affects capture queues, output
2653 * queues will always initialize waiting_for_buffers to false.
2655 if (q
->waiting_for_buffers
)
2656 return res
| POLLERR
;
2659 * For output streams you can write as long as there are fewer buffers
2660 * queued than there are buffers available.
2662 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && q
->queued_count
< q
->num_buffers
)
2663 return res
| POLLOUT
| POLLWRNORM
;
2665 if (list_empty(&q
->done_list
)) {
2667 * If the last buffer was dequeued from a capture queue,
2668 * return immediately. DQBUF will return -EPIPE.
2670 if (q
->last_buffer_dequeued
)
2671 return res
| POLLIN
| POLLRDNORM
;
2673 poll_wait(file
, &q
->done_wq
, wait
);
2677 * Take first buffer available for dequeuing.
2679 spin_lock_irqsave(&q
->done_lock
, flags
);
2680 if (!list_empty(&q
->done_list
))
2681 vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
,
2683 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2685 if (vb
&& (vb
->state
== VB2_BUF_STATE_DONE
2686 || vb
->state
== VB2_BUF_STATE_ERROR
)) {
2687 return (V4L2_TYPE_IS_OUTPUT(q
->type
)) ?
2688 res
| POLLOUT
| POLLWRNORM
:
2689 res
| POLLIN
| POLLRDNORM
;
2693 EXPORT_SYMBOL_GPL(vb2_poll
);
2696 * vb2_queue_init() - initialize a videobuf2 queue
2697 * @q: videobuf2 queue; this structure should be allocated in driver
2699 * The vb2_queue structure should be allocated by the driver. The driver is
2700 * responsible of clearing it's content and setting initial values for some
2701 * required entries before calling this function.
2702 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2703 * to the struct vb2_queue description in include/media/videobuf2-core.h
2704 * for more information.
2706 int vb2_queue_init(struct vb2_queue
*q
)
2713 WARN_ON(!q
->mem_ops
) ||
2714 WARN_ON(!q
->type
) ||
2715 WARN_ON(!q
->io_modes
) ||
2716 WARN_ON(!q
->ops
->queue_setup
) ||
2717 WARN_ON(!q
->ops
->buf_queue
) ||
2718 WARN_ON(q
->timestamp_flags
&
2719 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK
|
2720 V4L2_BUF_FLAG_TSTAMP_SRC_MASK
)))
2723 /* Warn that the driver should choose an appropriate timestamp type */
2724 WARN_ON((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
2725 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN
);
2727 INIT_LIST_HEAD(&q
->queued_list
);
2728 INIT_LIST_HEAD(&q
->done_list
);
2729 spin_lock_init(&q
->done_lock
);
2730 mutex_init(&q
->mmap_lock
);
2731 init_waitqueue_head(&q
->done_wq
);
2733 if (q
->buf_struct_size
== 0)
2734 q
->buf_struct_size
= sizeof(struct vb2_buffer
);
2738 EXPORT_SYMBOL_GPL(vb2_queue_init
);
2741 * vb2_queue_release() - stop streaming, release the queue and free memory
2742 * @q: videobuf2 queue
2744 * This function stops streaming and performs necessary clean ups, including
2745 * freeing video buffer memory. The driver is responsible for freeing
2746 * the vb2_queue structure itself.
2748 void vb2_queue_release(struct vb2_queue
*q
)
2750 __vb2_cleanup_fileio(q
);
2751 __vb2_queue_cancel(q
);
2752 mutex_lock(&q
->mmap_lock
);
2753 __vb2_queue_free(q
, q
->num_buffers
);
2754 mutex_unlock(&q
->mmap_lock
);
2756 EXPORT_SYMBOL_GPL(vb2_queue_release
);
2759 * struct vb2_fileio_buf - buffer context used by file io emulator
2761 * vb2 provides a compatibility layer and emulator of file io (read and
2762 * write) calls on top of streaming API. This structure is used for
2763 * tracking context related to the buffers.
2765 struct vb2_fileio_buf
{
2769 unsigned int queued
:1;
2773 * struct vb2_fileio_data - queue context used by file io emulator
2775 * @cur_index: the index of the buffer currently being read from or
2776 * written to. If equal to q->num_buffers then a new buffer
2778 * @initial_index: in the read() case all buffers are queued up immediately
2779 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2780 * buffers. However, in the write() case no buffers are initially
2781 * queued, instead whenever a buffer is full it is queued up by
2782 * __vb2_perform_fileio(). Only once all available buffers have
2783 * been queued up will __vb2_perform_fileio() start to dequeue
2784 * buffers. This means that initially __vb2_perform_fileio()
2785 * needs to know what buffer index to use when it is queuing up
2786 * the buffers for the first time. That initial index is stored
2787 * in this field. Once it is equal to q->num_buffers all
2788 * available buffers have been queued and __vb2_perform_fileio()
2789 * should start the normal dequeue/queue cycle.
2791 * vb2 provides a compatibility layer and emulator of file io (read and
2792 * write) calls on top of streaming API. For proper operation it required
2793 * this structure to save the driver state between each call of the read
2794 * or write function.
2796 struct vb2_fileio_data
{
2797 struct v4l2_requestbuffers req
;
2798 struct v4l2_plane p
;
2799 struct v4l2_buffer b
;
2800 struct vb2_fileio_buf bufs
[VIDEO_MAX_FRAME
];
2801 unsigned int cur_index
;
2802 unsigned int initial_index
;
2803 unsigned int q_count
;
2804 unsigned int dq_count
;
2805 unsigned read_once
:1;
2806 unsigned write_immediately
:1;
2810 * __vb2_init_fileio() - initialize file io emulator
2811 * @q: videobuf2 queue
2812 * @read: mode selector (1 means read, 0 means write)
2814 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
)
2816 struct vb2_fileio_data
*fileio
;
2818 unsigned int count
= 0;
2823 if (WARN_ON((read
&& !(q
->io_modes
& VB2_READ
)) ||
2824 (!read
&& !(q
->io_modes
& VB2_WRITE
))))
2828 * Check if device supports mapping buffers to kernel virtual space.
2830 if (!q
->mem_ops
->vaddr
)
2834 * Check if streaming api has not been already activated.
2836 if (q
->streaming
|| q
->num_buffers
> 0)
2840 * Start with count 1, driver can increase it in queue_setup()
2844 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2845 (read
) ? "read" : "write", count
, q
->fileio_read_once
,
2846 q
->fileio_write_immediately
);
2848 fileio
= kzalloc(sizeof(struct vb2_fileio_data
), GFP_KERNEL
);
2852 fileio
->read_once
= q
->fileio_read_once
;
2853 fileio
->write_immediately
= q
->fileio_write_immediately
;
2856 * Request buffers and use MMAP type to force driver
2857 * to allocate buffers by itself.
2859 fileio
->req
.count
= count
;
2860 fileio
->req
.memory
= V4L2_MEMORY_MMAP
;
2861 fileio
->req
.type
= q
->type
;
2863 ret
= __reqbufs(q
, &fileio
->req
);
2868 * Check if plane_count is correct
2869 * (multiplane buffers are not supported).
2871 if (q
->bufs
[0]->num_planes
!= 1) {
2877 * Get kernel address of each buffer.
2879 for (i
= 0; i
< q
->num_buffers
; i
++) {
2880 fileio
->bufs
[i
].vaddr
= vb2_plane_vaddr(q
->bufs
[i
], 0);
2881 if (fileio
->bufs
[i
].vaddr
== NULL
) {
2885 fileio
->bufs
[i
].size
= vb2_plane_size(q
->bufs
[i
], 0);
2889 * Read mode requires pre queuing of all buffers.
2892 bool is_multiplanar
= V4L2_TYPE_IS_MULTIPLANAR(q
->type
);
2895 * Queue all buffers.
2897 for (i
= 0; i
< q
->num_buffers
; i
++) {
2898 struct v4l2_buffer
*b
= &fileio
->b
;
2900 memset(b
, 0, sizeof(*b
));
2902 if (is_multiplanar
) {
2903 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
2904 b
->m
.planes
= &fileio
->p
;
2907 b
->memory
= q
->memory
;
2909 ret
= vb2_internal_qbuf(q
, b
);
2912 fileio
->bufs
[i
].queued
= 1;
2915 * All buffers have been queued, so mark that by setting
2916 * initial_index to q->num_buffers
2918 fileio
->initial_index
= q
->num_buffers
;
2919 fileio
->cur_index
= q
->num_buffers
;
2925 ret
= vb2_internal_streamon(q
, q
->type
);
2932 fileio
->req
.count
= 0;
2933 __reqbufs(q
, &fileio
->req
);
2942 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2943 * @q: videobuf2 queue
2945 static int __vb2_cleanup_fileio(struct vb2_queue
*q
)
2947 struct vb2_fileio_data
*fileio
= q
->fileio
;
2950 vb2_internal_streamoff(q
, q
->type
);
2952 fileio
->req
.count
= 0;
2953 vb2_reqbufs(q
, &fileio
->req
);
2955 dprintk(3, "file io emulator closed\n");
2961 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2962 * @q: videobuf2 queue
2963 * @data: pointed to target userspace buffer
2964 * @count: number of bytes to read or write
2965 * @ppos: file handle position tracking pointer
2966 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2967 * @read: access mode selector (1 means read, 0 means write)
2969 static size_t __vb2_perform_fileio(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2970 loff_t
*ppos
, int nonblock
, int read
)
2972 struct vb2_fileio_data
*fileio
;
2973 struct vb2_fileio_buf
*buf
;
2974 bool is_multiplanar
= V4L2_TYPE_IS_MULTIPLANAR(q
->type
);
2976 * When using write() to write data to an output video node the vb2 core
2977 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2978 * else is able to provide this information with the write() operation.
2980 bool set_timestamp
= !read
&&
2981 (q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
2982 V4L2_BUF_FLAG_TIMESTAMP_COPY
;
2985 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2986 read
? "read" : "write", (long)*ppos
, count
,
2987 nonblock
? "non" : "");
2993 * Initialize emulator on first call.
2995 if (!vb2_fileio_is_active(q
)) {
2996 ret
= __vb2_init_fileio(q
, read
);
2997 dprintk(3, "vb2_init_fileio result: %d\n", ret
);
3004 * Check if we need to dequeue the buffer.
3006 index
= fileio
->cur_index
;
3007 if (index
>= q
->num_buffers
) {
3009 * Call vb2_dqbuf to get buffer back.
3011 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3012 fileio
->b
.type
= q
->type
;
3013 fileio
->b
.memory
= q
->memory
;
3014 if (is_multiplanar
) {
3015 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
3016 fileio
->b
.m
.planes
= &fileio
->p
;
3017 fileio
->b
.length
= 1;
3019 ret
= vb2_internal_dqbuf(q
, &fileio
->b
, nonblock
);
3020 dprintk(5, "vb2_dqbuf result: %d\n", ret
);
3023 fileio
->dq_count
+= 1;
3025 fileio
->cur_index
= index
= fileio
->b
.index
;
3026 buf
= &fileio
->bufs
[index
];
3029 * Get number of bytes filled by the driver
3033 buf
->size
= read
? vb2_get_plane_payload(q
->bufs
[index
], 0)
3034 : vb2_plane_size(q
->bufs
[index
], 0);
3035 /* Compensate for data_offset on read in the multiplanar case. */
3036 if (is_multiplanar
&& read
&&
3037 fileio
->b
.m
.planes
[0].data_offset
< buf
->size
) {
3038 buf
->pos
= fileio
->b
.m
.planes
[0].data_offset
;
3039 buf
->size
-= buf
->pos
;
3042 buf
= &fileio
->bufs
[index
];
3046 * Limit count on last few bytes of the buffer.
3048 if (buf
->pos
+ count
> buf
->size
) {
3049 count
= buf
->size
- buf
->pos
;
3050 dprintk(5, "reducing read count: %zd\n", count
);
3054 * Transfer data to userspace.
3056 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
3057 count
, index
, buf
->pos
);
3059 ret
= copy_to_user(data
, buf
->vaddr
+ buf
->pos
, count
);
3061 ret
= copy_from_user(buf
->vaddr
+ buf
->pos
, data
, count
);
3063 dprintk(3, "error copying data\n");
3074 * Queue next buffer if required.
3076 if (buf
->pos
== buf
->size
|| (!read
&& fileio
->write_immediately
)) {
3078 * Check if this is the last buffer to read.
3080 if (read
&& fileio
->read_once
&& fileio
->dq_count
== 1) {
3081 dprintk(3, "read limit reached\n");
3082 return __vb2_cleanup_fileio(q
);
3086 * Call vb2_qbuf and give buffer to the driver.
3088 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3089 fileio
->b
.type
= q
->type
;
3090 fileio
->b
.memory
= q
->memory
;
3091 fileio
->b
.index
= index
;
3092 fileio
->b
.bytesused
= buf
->pos
;
3093 if (is_multiplanar
) {
3094 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
3095 fileio
->p
.bytesused
= buf
->pos
;
3096 fileio
->b
.m
.planes
= &fileio
->p
;
3097 fileio
->b
.length
= 1;
3100 v4l2_get_timestamp(&fileio
->b
.timestamp
);
3101 ret
= vb2_internal_qbuf(q
, &fileio
->b
);
3102 dprintk(5, "vb2_dbuf result: %d\n", ret
);
3107 * Buffer has been queued, update the status
3111 buf
->size
= vb2_plane_size(q
->bufs
[index
], 0);
3112 fileio
->q_count
+= 1;
3114 * If we are queuing up buffers for the first time, then
3115 * increase initial_index by one.
3117 if (fileio
->initial_index
< q
->num_buffers
)
3118 fileio
->initial_index
++;
3120 * The next buffer to use is either a buffer that's going to be
3121 * queued for the first time (initial_index < q->num_buffers)
3122 * or it is equal to q->num_buffers, meaning that the next
3123 * time we need to dequeue a buffer since we've now queued up
3124 * all the 'first time' buffers.
3126 fileio
->cur_index
= fileio
->initial_index
;
3130 * Return proper number of bytes processed.
3137 size_t vb2_read(struct vb2_queue
*q
, char __user
*data
, size_t count
,
3138 loff_t
*ppos
, int nonblocking
)
3140 return __vb2_perform_fileio(q
, data
, count
, ppos
, nonblocking
, 1);
3142 EXPORT_SYMBOL_GPL(vb2_read
);
3144 size_t vb2_write(struct vb2_queue
*q
, const char __user
*data
, size_t count
,
3145 loff_t
*ppos
, int nonblocking
)
3147 return __vb2_perform_fileio(q
, (char __user
*) data
, count
,
3148 ppos
, nonblocking
, 0);
3150 EXPORT_SYMBOL_GPL(vb2_write
);
3152 struct vb2_threadio_data
{
3153 struct task_struct
*thread
;
3159 static int vb2_thread(void *data
)
3161 struct vb2_queue
*q
= data
;
3162 struct vb2_threadio_data
*threadio
= q
->threadio
;
3163 struct vb2_fileio_data
*fileio
= q
->fileio
;
3164 bool set_timestamp
= false;
3169 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
3170 prequeue
= q
->num_buffers
;
3172 (q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
3173 V4L2_BUF_FLAG_TIMESTAMP_COPY
;
3179 struct vb2_buffer
*vb
;
3182 * Call vb2_dqbuf to get buffer back.
3184 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3185 fileio
->b
.type
= q
->type
;
3186 fileio
->b
.memory
= q
->memory
;
3188 fileio
->b
.index
= index
++;
3191 call_void_qop(q
, wait_finish
, q
);
3192 if (!threadio
->stop
)
3193 ret
= vb2_internal_dqbuf(q
, &fileio
->b
, 0);
3194 call_void_qop(q
, wait_prepare
, q
);
3195 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret
);
3197 if (ret
|| threadio
->stop
)
3201 vb
= q
->bufs
[fileio
->b
.index
];
3202 if (!(fileio
->b
.flags
& V4L2_BUF_FLAG_ERROR
))
3203 if (threadio
->fnc(vb
, threadio
->priv
))
3205 call_void_qop(q
, wait_finish
, q
);
3207 v4l2_get_timestamp(&fileio
->b
.timestamp
);
3208 if (!threadio
->stop
)
3209 ret
= vb2_internal_qbuf(q
, &fileio
->b
);
3210 call_void_qop(q
, wait_prepare
, q
);
3211 if (ret
|| threadio
->stop
)
3215 /* Hmm, linux becomes *very* unhappy without this ... */
3216 while (!kthread_should_stop()) {
3217 set_current_state(TASK_INTERRUPTIBLE
);
3224 * This function should not be used for anything else but the videobuf2-dvb
3225 * support. If you think you have another good use-case for this, then please
3226 * contact the linux-media mailinglist first.
3228 int vb2_thread_start(struct vb2_queue
*q
, vb2_thread_fnc fnc
, void *priv
,
3229 const char *thread_name
)
3231 struct vb2_threadio_data
*threadio
;
3238 if (WARN_ON(q
->fileio
))
3241 threadio
= kzalloc(sizeof(*threadio
), GFP_KERNEL
);
3242 if (threadio
== NULL
)
3244 threadio
->fnc
= fnc
;
3245 threadio
->priv
= priv
;
3247 ret
= __vb2_init_fileio(q
, !V4L2_TYPE_IS_OUTPUT(q
->type
));
3248 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret
);
3251 q
->threadio
= threadio
;
3252 threadio
->thread
= kthread_run(vb2_thread
, q
, "vb2-%s", thread_name
);
3253 if (IS_ERR(threadio
->thread
)) {
3254 ret
= PTR_ERR(threadio
->thread
);
3255 threadio
->thread
= NULL
;
3261 __vb2_cleanup_fileio(q
);
3266 EXPORT_SYMBOL_GPL(vb2_thread_start
);
3268 int vb2_thread_stop(struct vb2_queue
*q
)
3270 struct vb2_threadio_data
*threadio
= q
->threadio
;
3273 if (threadio
== NULL
)
3275 threadio
->stop
= true;
3276 /* Wake up all pending sleeps in the thread */
3278 err
= kthread_stop(threadio
->thread
);
3279 __vb2_cleanup_fileio(q
);
3280 threadio
->thread
= NULL
;
3285 EXPORT_SYMBOL_GPL(vb2_thread_stop
);
3288 * The following functions are not part of the vb2 core API, but are helper
3289 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3290 * and struct vb2_ops.
3291 * They contain boilerplate code that most if not all drivers have to do
3292 * and so they simplify the driver code.
3295 /* The queue is busy if there is a owner and you are not that owner. */
3296 static inline bool vb2_queue_is_busy(struct video_device
*vdev
, struct file
*file
)
3298 return vdev
->queue
->owner
&& vdev
->queue
->owner
!= file
->private_data
;
3301 /* vb2 ioctl helpers */
3303 int vb2_ioctl_reqbufs(struct file
*file
, void *priv
,
3304 struct v4l2_requestbuffers
*p
)
3306 struct video_device
*vdev
= video_devdata(file
);
3307 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->type
);
3311 if (vb2_queue_is_busy(vdev
, file
))
3313 res
= __reqbufs(vdev
->queue
, p
);
3314 /* If count == 0, then the owner has released all buffers and he
3315 is no longer owner of the queue. Otherwise we have a new owner. */
3317 vdev
->queue
->owner
= p
->count
? file
->private_data
: NULL
;
3320 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs
);
3322 int vb2_ioctl_create_bufs(struct file
*file
, void *priv
,
3323 struct v4l2_create_buffers
*p
)
3325 struct video_device
*vdev
= video_devdata(file
);
3326 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->format
.type
);
3328 p
->index
= vdev
->queue
->num_buffers
;
3329 /* If count == 0, then just check if memory and type are valid.
3330 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3332 return res
!= -EBUSY
? res
: 0;
3335 if (vb2_queue_is_busy(vdev
, file
))
3337 res
= __create_bufs(vdev
->queue
, p
);
3339 vdev
->queue
->owner
= file
->private_data
;
3342 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs
);
3344 int vb2_ioctl_prepare_buf(struct file
*file
, void *priv
,
3345 struct v4l2_buffer
*p
)
3347 struct video_device
*vdev
= video_devdata(file
);
3349 if (vb2_queue_is_busy(vdev
, file
))
3351 return vb2_prepare_buf(vdev
->queue
, p
);
3353 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf
);
3355 int vb2_ioctl_querybuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3357 struct video_device
*vdev
= video_devdata(file
);
3359 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3360 return vb2_querybuf(vdev
->queue
, p
);
3362 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf
);
3364 int vb2_ioctl_qbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3366 struct video_device
*vdev
= video_devdata(file
);
3368 if (vb2_queue_is_busy(vdev
, file
))
3370 return vb2_qbuf(vdev
->queue
, p
);
3372 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf
);
3374 int vb2_ioctl_dqbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3376 struct video_device
*vdev
= video_devdata(file
);
3378 if (vb2_queue_is_busy(vdev
, file
))
3380 return vb2_dqbuf(vdev
->queue
, p
, file
->f_flags
& O_NONBLOCK
);
3382 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf
);
3384 int vb2_ioctl_streamon(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
3386 struct video_device
*vdev
= video_devdata(file
);
3388 if (vb2_queue_is_busy(vdev
, file
))
3390 return vb2_streamon(vdev
->queue
, i
);
3392 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon
);
3394 int vb2_ioctl_streamoff(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
3396 struct video_device
*vdev
= video_devdata(file
);
3398 if (vb2_queue_is_busy(vdev
, file
))
3400 return vb2_streamoff(vdev
->queue
, i
);
3402 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff
);
3404 int vb2_ioctl_expbuf(struct file
*file
, void *priv
, struct v4l2_exportbuffer
*p
)
3406 struct video_device
*vdev
= video_devdata(file
);
3408 if (vb2_queue_is_busy(vdev
, file
))
3410 return vb2_expbuf(vdev
->queue
, p
);
3412 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf
);
3414 /* v4l2_file_operations helpers */
3416 int vb2_fop_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3418 struct video_device
*vdev
= video_devdata(file
);
3420 return vb2_mmap(vdev
->queue
, vma
);
3422 EXPORT_SYMBOL_GPL(vb2_fop_mmap
);
3424 int _vb2_fop_release(struct file
*file
, struct mutex
*lock
)
3426 struct video_device
*vdev
= video_devdata(file
);
3430 if (file
->private_data
== vdev
->queue
->owner
) {
3431 vb2_queue_release(vdev
->queue
);
3432 vdev
->queue
->owner
= NULL
;
3436 return v4l2_fh_release(file
);
3438 EXPORT_SYMBOL_GPL(_vb2_fop_release
);
3440 int vb2_fop_release(struct file
*file
)
3442 struct video_device
*vdev
= video_devdata(file
);
3443 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3445 return _vb2_fop_release(file
, lock
);
3447 EXPORT_SYMBOL_GPL(vb2_fop_release
);
3449 ssize_t
vb2_fop_write(struct file
*file
, const char __user
*buf
,
3450 size_t count
, loff_t
*ppos
)
3452 struct video_device
*vdev
= video_devdata(file
);
3453 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3456 if (!(vdev
->queue
->io_modes
& VB2_WRITE
))
3458 if (lock
&& mutex_lock_interruptible(lock
))
3459 return -ERESTARTSYS
;
3460 if (vb2_queue_is_busy(vdev
, file
))
3462 err
= vb2_write(vdev
->queue
, buf
, count
, ppos
,
3463 file
->f_flags
& O_NONBLOCK
);
3464 if (vdev
->queue
->fileio
)
3465 vdev
->queue
->owner
= file
->private_data
;
3471 EXPORT_SYMBOL_GPL(vb2_fop_write
);
3473 ssize_t
vb2_fop_read(struct file
*file
, char __user
*buf
,
3474 size_t count
, loff_t
*ppos
)
3476 struct video_device
*vdev
= video_devdata(file
);
3477 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3480 if (!(vdev
->queue
->io_modes
& VB2_READ
))
3482 if (lock
&& mutex_lock_interruptible(lock
))
3483 return -ERESTARTSYS
;
3484 if (vb2_queue_is_busy(vdev
, file
))
3486 err
= vb2_read(vdev
->queue
, buf
, count
, ppos
,
3487 file
->f_flags
& O_NONBLOCK
);
3488 if (vdev
->queue
->fileio
)
3489 vdev
->queue
->owner
= file
->private_data
;
3495 EXPORT_SYMBOL_GPL(vb2_fop_read
);
3497 unsigned int vb2_fop_poll(struct file
*file
, poll_table
*wait
)
3499 struct video_device
*vdev
= video_devdata(file
);
3500 struct vb2_queue
*q
= vdev
->queue
;
3501 struct mutex
*lock
= q
->lock
? q
->lock
: vdev
->lock
;
3506 * If this helper doesn't know how to lock, then you shouldn't be using
3507 * it but you should write your own.
3511 if (lock
&& mutex_lock_interruptible(lock
))
3516 res
= vb2_poll(vdev
->queue
, file
, wait
);
3518 /* If fileio was started, then we have a new queue owner. */
3519 if (!fileio
&& q
->fileio
)
3520 q
->owner
= file
->private_data
;
3525 EXPORT_SYMBOL_GPL(vb2_fop_poll
);
3528 unsigned long vb2_fop_get_unmapped_area(struct file
*file
, unsigned long addr
,
3529 unsigned long len
, unsigned long pgoff
, unsigned long flags
)
3531 struct video_device
*vdev
= video_devdata(file
);
3533 return vb2_get_unmapped_area(vdev
->queue
, addr
, len
, pgoff
, flags
);
3535 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area
);
3538 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3540 void vb2_ops_wait_prepare(struct vb2_queue
*vq
)
3542 mutex_unlock(vq
->lock
);
3544 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare
);
3546 void vb2_ops_wait_finish(struct vb2_queue
*vq
)
3548 mutex_lock(vq
->lock
);
3550 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish
);
3552 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3553 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3554 MODULE_LICENSE("GPL");