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
);
185 static void __enqueue_in_driver(struct vb2_buffer
*vb
);
188 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
190 static int __vb2_buf_mem_alloc(struct vb2_buffer
*vb
)
192 struct vb2_queue
*q
= vb
->vb2_queue
;
193 enum dma_data_direction dma_dir
=
194 V4L2_TYPE_IS_OUTPUT(q
->type
) ? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
199 * Allocate memory for all planes in this buffer
200 * NOTE: mmapped areas should be page aligned
202 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
203 unsigned long size
= PAGE_ALIGN(q
->plane_sizes
[plane
]);
205 mem_priv
= call_ptr_memop(vb
, alloc
, q
->alloc_ctx
[plane
],
206 size
, dma_dir
, q
->gfp_flags
);
207 if (IS_ERR_OR_NULL(mem_priv
))
210 /* Associate allocator private data with this plane */
211 vb
->planes
[plane
].mem_priv
= mem_priv
;
212 vb
->v4l2_planes
[plane
].length
= q
->plane_sizes
[plane
];
217 /* Free already allocated memory if one of the allocations failed */
218 for (; plane
> 0; --plane
) {
219 call_void_memop(vb
, put
, vb
->planes
[plane
- 1].mem_priv
);
220 vb
->planes
[plane
- 1].mem_priv
= NULL
;
227 * __vb2_buf_mem_free() - free memory of the given buffer
229 static void __vb2_buf_mem_free(struct vb2_buffer
*vb
)
233 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
234 call_void_memop(vb
, put
, vb
->planes
[plane
].mem_priv
);
235 vb
->planes
[plane
].mem_priv
= NULL
;
236 dprintk(3, "freed plane %d of buffer %d\n", plane
,
242 * __vb2_buf_userptr_put() - release userspace memory associated with
245 static void __vb2_buf_userptr_put(struct vb2_buffer
*vb
)
249 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
250 if (vb
->planes
[plane
].mem_priv
)
251 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
252 vb
->planes
[plane
].mem_priv
= NULL
;
257 * __vb2_plane_dmabuf_put() - release memory associated with
258 * a DMABUF shared plane
260 static void __vb2_plane_dmabuf_put(struct vb2_buffer
*vb
, struct vb2_plane
*p
)
266 call_void_memop(vb
, unmap_dmabuf
, p
->mem_priv
);
268 call_void_memop(vb
, detach_dmabuf
, p
->mem_priv
);
269 dma_buf_put(p
->dbuf
);
270 memset(p
, 0, sizeof(*p
));
274 * __vb2_buf_dmabuf_put() - release memory associated with
275 * a DMABUF shared buffer
277 static void __vb2_buf_dmabuf_put(struct vb2_buffer
*vb
)
281 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
282 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
286 * __setup_lengths() - setup initial lengths for every plane in
287 * every buffer on the queue
289 static void __setup_lengths(struct vb2_queue
*q
, unsigned int n
)
291 unsigned int buffer
, plane
;
292 struct vb2_buffer
*vb
;
294 for (buffer
= q
->num_buffers
; buffer
< q
->num_buffers
+ n
; ++buffer
) {
295 vb
= q
->bufs
[buffer
];
299 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
300 vb
->v4l2_planes
[plane
].length
= q
->plane_sizes
[plane
];
305 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
306 * every buffer on the queue
308 static void __setup_offsets(struct vb2_queue
*q
, unsigned int n
)
310 unsigned int buffer
, plane
;
311 struct vb2_buffer
*vb
;
314 if (q
->num_buffers
) {
315 struct v4l2_plane
*p
;
316 vb
= q
->bufs
[q
->num_buffers
- 1];
317 p
= &vb
->v4l2_planes
[vb
->num_planes
- 1];
318 off
= PAGE_ALIGN(p
->m
.mem_offset
+ p
->length
);
323 for (buffer
= q
->num_buffers
; buffer
< q
->num_buffers
+ n
; ++buffer
) {
324 vb
= q
->bufs
[buffer
];
328 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
329 vb
->v4l2_planes
[plane
].m
.mem_offset
= off
;
331 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
334 off
+= vb
->v4l2_planes
[plane
].length
;
335 off
= PAGE_ALIGN(off
);
341 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
342 * video buffer memory for all buffers/planes on the queue and initializes the
345 * Returns the number of buffers successfully allocated.
347 static int __vb2_queue_alloc(struct vb2_queue
*q
, enum v4l2_memory memory
,
348 unsigned int num_buffers
, unsigned int num_planes
)
351 struct vb2_buffer
*vb
;
354 for (buffer
= 0; buffer
< num_buffers
; ++buffer
) {
355 /* Allocate videobuf buffer structures */
356 vb
= kzalloc(q
->buf_struct_size
, GFP_KERNEL
);
358 dprintk(1, "memory alloc for buffer struct failed\n");
362 /* Length stores number of planes for multiplanar buffers */
363 if (V4L2_TYPE_IS_MULTIPLANAR(q
->type
))
364 vb
->v4l2_buf
.length
= num_planes
;
366 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
368 vb
->num_planes
= num_planes
;
369 vb
->v4l2_buf
.index
= q
->num_buffers
+ buffer
;
370 vb
->v4l2_buf
.type
= q
->type
;
371 vb
->v4l2_buf
.memory
= memory
;
373 /* Allocate video buffer memory for the MMAP type */
374 if (memory
== V4L2_MEMORY_MMAP
) {
375 ret
= __vb2_buf_mem_alloc(vb
);
377 dprintk(1, "failed allocating memory for "
378 "buffer %d\n", buffer
);
383 * Call the driver-provided buffer initialization
384 * callback, if given. An error in initialization
385 * results in queue setup failure.
387 ret
= call_vb_qop(vb
, buf_init
, vb
);
389 dprintk(1, "buffer %d %p initialization"
390 " failed\n", buffer
, vb
);
391 __vb2_buf_mem_free(vb
);
397 q
->bufs
[q
->num_buffers
+ buffer
] = vb
;
400 __setup_lengths(q
, buffer
);
401 if (memory
== V4L2_MEMORY_MMAP
)
402 __setup_offsets(q
, buffer
);
404 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
411 * __vb2_free_mem() - release all video buffer memory for a given queue
413 static void __vb2_free_mem(struct vb2_queue
*q
, unsigned int buffers
)
416 struct vb2_buffer
*vb
;
418 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
420 vb
= q
->bufs
[buffer
];
424 /* Free MMAP buffers or release USERPTR buffers */
425 if (q
->memory
== V4L2_MEMORY_MMAP
)
426 __vb2_buf_mem_free(vb
);
427 else if (q
->memory
== V4L2_MEMORY_DMABUF
)
428 __vb2_buf_dmabuf_put(vb
);
430 __vb2_buf_userptr_put(vb
);
435 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
436 * related information, if no buffers are left return the queue to an
437 * uninitialized state. Might be called even if the queue has already been freed.
439 static int __vb2_queue_free(struct vb2_queue
*q
, unsigned int buffers
)
444 * Sanity check: when preparing a buffer the queue lock is released for
445 * a short while (see __buf_prepare for the details), which would allow
446 * a race with a reqbufs which can call this function. Removing the
447 * buffers from underneath __buf_prepare is obviously a bad idea, so we
448 * check if any of the buffers is in the state PREPARING, and if so we
449 * just return -EAGAIN.
451 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
453 if (q
->bufs
[buffer
] == NULL
)
455 if (q
->bufs
[buffer
]->state
== VB2_BUF_STATE_PREPARING
) {
456 dprintk(1, "preparing buffers, cannot free\n");
461 /* Call driver-provided cleanup function for each buffer, if provided */
462 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
464 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
466 if (vb
&& vb
->planes
[0].mem_priv
)
467 call_void_vb_qop(vb
, buf_cleanup
, vb
);
470 /* Release video buffer memory */
471 __vb2_free_mem(q
, buffers
);
473 #ifdef CONFIG_VIDEO_ADV_DEBUG
475 * Check that all the calls were balances during the life-time of this
476 * queue. If not (or if the debug level is 1 or up), then dump the
477 * counters to the kernel log.
479 if (q
->num_buffers
) {
480 bool unbalanced
= q
->cnt_start_streaming
!= q
->cnt_stop_streaming
||
481 q
->cnt_wait_prepare
!= q
->cnt_wait_finish
;
483 if (unbalanced
|| debug
) {
484 pr_info("vb2: counters for queue %p:%s\n", q
,
485 unbalanced
? " UNBALANCED!" : "");
486 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
487 q
->cnt_queue_setup
, q
->cnt_start_streaming
,
488 q
->cnt_stop_streaming
);
489 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
490 q
->cnt_wait_prepare
, q
->cnt_wait_finish
);
492 q
->cnt_queue_setup
= 0;
493 q
->cnt_wait_prepare
= 0;
494 q
->cnt_wait_finish
= 0;
495 q
->cnt_start_streaming
= 0;
496 q
->cnt_stop_streaming
= 0;
498 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
499 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
500 bool unbalanced
= vb
->cnt_mem_alloc
!= vb
->cnt_mem_put
||
501 vb
->cnt_mem_prepare
!= vb
->cnt_mem_finish
||
502 vb
->cnt_mem_get_userptr
!= vb
->cnt_mem_put_userptr
||
503 vb
->cnt_mem_attach_dmabuf
!= vb
->cnt_mem_detach_dmabuf
||
504 vb
->cnt_mem_map_dmabuf
!= vb
->cnt_mem_unmap_dmabuf
||
505 vb
->cnt_buf_queue
!= vb
->cnt_buf_done
||
506 vb
->cnt_buf_prepare
!= vb
->cnt_buf_finish
||
507 vb
->cnt_buf_init
!= vb
->cnt_buf_cleanup
;
509 if (unbalanced
|| debug
) {
510 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
511 q
, buffer
, unbalanced
? " UNBALANCED!" : "");
512 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
513 vb
->cnt_buf_init
, vb
->cnt_buf_cleanup
,
514 vb
->cnt_buf_prepare
, vb
->cnt_buf_finish
);
515 pr_info("vb2: buf_queue: %u buf_done: %u\n",
516 vb
->cnt_buf_queue
, vb
->cnt_buf_done
);
517 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
518 vb
->cnt_mem_alloc
, vb
->cnt_mem_put
,
519 vb
->cnt_mem_prepare
, vb
->cnt_mem_finish
,
521 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
522 vb
->cnt_mem_get_userptr
, vb
->cnt_mem_put_userptr
);
523 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
524 vb
->cnt_mem_attach_dmabuf
, vb
->cnt_mem_detach_dmabuf
,
525 vb
->cnt_mem_map_dmabuf
, vb
->cnt_mem_unmap_dmabuf
);
526 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
527 vb
->cnt_mem_get_dmabuf
,
528 vb
->cnt_mem_num_users
,
535 /* Free videobuf buffers */
536 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
538 kfree(q
->bufs
[buffer
]);
539 q
->bufs
[buffer
] = NULL
;
542 q
->num_buffers
-= buffers
;
543 if (!q
->num_buffers
) {
545 INIT_LIST_HEAD(&q
->queued_list
);
551 * __verify_planes_array() - verify that the planes array passed in struct
552 * v4l2_buffer from userspace can be safely used
554 static int __verify_planes_array(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
556 if (!V4L2_TYPE_IS_MULTIPLANAR(b
->type
))
559 /* Is memory for copying plane information present? */
560 if (NULL
== b
->m
.planes
) {
561 dprintk(1, "multi-planar buffer passed but "
562 "planes array not provided\n");
566 if (b
->length
< vb
->num_planes
|| b
->length
> VIDEO_MAX_PLANES
) {
567 dprintk(1, "incorrect planes array length, "
568 "expected %d, got %d\n", vb
->num_planes
, b
->length
);
576 * __verify_length() - Verify that the bytesused value for each plane fits in
577 * the plane length and that the data offset doesn't exceed the bytesused value.
579 static int __verify_length(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
582 unsigned int bytesused
;
585 if (!V4L2_TYPE_IS_OUTPUT(b
->type
))
588 if (V4L2_TYPE_IS_MULTIPLANAR(b
->type
)) {
589 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
590 length
= (b
->memory
== V4L2_MEMORY_USERPTR
||
591 b
->memory
== V4L2_MEMORY_DMABUF
)
592 ? b
->m
.planes
[plane
].length
593 : vb
->v4l2_planes
[plane
].length
;
594 bytesused
= b
->m
.planes
[plane
].bytesused
595 ? b
->m
.planes
[plane
].bytesused
: length
;
597 if (b
->m
.planes
[plane
].bytesused
> length
)
600 if (b
->m
.planes
[plane
].data_offset
> 0 &&
601 b
->m
.planes
[plane
].data_offset
>= bytesused
)
605 length
= (b
->memory
== V4L2_MEMORY_USERPTR
)
606 ? b
->length
: vb
->v4l2_planes
[0].length
;
607 bytesused
= b
->bytesused
? b
->bytesused
: length
;
609 if (b
->bytesused
> length
)
617 * __buffer_in_use() - return true if the buffer is in use and
618 * the queue cannot be freed (by the means of REQBUFS(0)) call
620 static bool __buffer_in_use(struct vb2_queue
*q
, struct vb2_buffer
*vb
)
623 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
624 void *mem_priv
= vb
->planes
[plane
].mem_priv
;
626 * If num_users() has not been provided, call_memop
627 * will return 0, apparently nobody cares about this
628 * case anyway. If num_users() returns more than 1,
629 * we are not the only user of the plane's memory.
631 if (mem_priv
&& call_memop(vb
, num_users
, mem_priv
) > 1)
638 * __buffers_in_use() - return true if any buffers on the queue are in use and
639 * the queue cannot be freed (by the means of REQBUFS(0)) call
641 static bool __buffers_in_use(struct vb2_queue
*q
)
644 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
645 if (__buffer_in_use(q
, q
->bufs
[buffer
]))
652 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
653 * returned to userspace
655 static void __fill_v4l2_buffer(struct vb2_buffer
*vb
, struct v4l2_buffer
*b
)
657 struct vb2_queue
*q
= vb
->vb2_queue
;
659 /* Copy back data such as timestamp, flags, etc. */
660 memcpy(b
, &vb
->v4l2_buf
, offsetof(struct v4l2_buffer
, m
));
661 b
->reserved2
= vb
->v4l2_buf
.reserved2
;
662 b
->reserved
= vb
->v4l2_buf
.reserved
;
664 if (V4L2_TYPE_IS_MULTIPLANAR(q
->type
)) {
666 * Fill in plane-related data if userspace provided an array
667 * for it. The caller has already verified memory and size.
669 b
->length
= vb
->num_planes
;
670 memcpy(b
->m
.planes
, vb
->v4l2_planes
,
671 b
->length
* sizeof(struct v4l2_plane
));
674 * We use length and offset in v4l2_planes array even for
675 * single-planar buffers, but userspace does not.
677 b
->length
= vb
->v4l2_planes
[0].length
;
678 b
->bytesused
= vb
->v4l2_planes
[0].bytesused
;
679 if (q
->memory
== V4L2_MEMORY_MMAP
)
680 b
->m
.offset
= vb
->v4l2_planes
[0].m
.mem_offset
;
681 else if (q
->memory
== V4L2_MEMORY_USERPTR
)
682 b
->m
.userptr
= vb
->v4l2_planes
[0].m
.userptr
;
683 else if (q
->memory
== V4L2_MEMORY_DMABUF
)
684 b
->m
.fd
= vb
->v4l2_planes
[0].m
.fd
;
688 * Clear any buffer state related flags.
690 b
->flags
&= ~V4L2_BUFFER_MASK_FLAGS
;
691 b
->flags
|= q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
;
692 if ((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) !=
693 V4L2_BUF_FLAG_TIMESTAMP_COPY
) {
695 * For non-COPY timestamps, drop timestamp source bits
696 * and obtain the timestamp source from the queue.
698 b
->flags
&= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
699 b
->flags
|= q
->timestamp_flags
& V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
703 case VB2_BUF_STATE_QUEUED
:
704 case VB2_BUF_STATE_ACTIVE
:
705 b
->flags
|= V4L2_BUF_FLAG_QUEUED
;
707 case VB2_BUF_STATE_ERROR
:
708 b
->flags
|= V4L2_BUF_FLAG_ERROR
;
710 case VB2_BUF_STATE_DONE
:
711 b
->flags
|= V4L2_BUF_FLAG_DONE
;
713 case VB2_BUF_STATE_PREPARED
:
714 b
->flags
|= V4L2_BUF_FLAG_PREPARED
;
716 case VB2_BUF_STATE_PREPARING
:
717 case VB2_BUF_STATE_DEQUEUED
:
722 if (__buffer_in_use(q
, vb
))
723 b
->flags
|= V4L2_BUF_FLAG_MAPPED
;
727 * vb2_querybuf() - query video buffer information
729 * @b: buffer struct passed from userspace to vidioc_querybuf handler
732 * Should be called from vidioc_querybuf ioctl handler in driver.
733 * This function will verify the passed v4l2_buffer structure and fill the
734 * relevant information for the userspace.
736 * The return values from this function are intended to be directly returned
737 * from vidioc_querybuf handler in driver.
739 int vb2_querybuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
741 struct vb2_buffer
*vb
;
744 if (b
->type
!= q
->type
) {
745 dprintk(1, "wrong buffer type\n");
749 if (b
->index
>= q
->num_buffers
) {
750 dprintk(1, "buffer index out of range\n");
753 vb
= q
->bufs
[b
->index
];
754 ret
= __verify_planes_array(vb
, b
);
756 __fill_v4l2_buffer(vb
, b
);
759 EXPORT_SYMBOL(vb2_querybuf
);
762 * __verify_userptr_ops() - verify that all memory operations required for
763 * USERPTR queue type have been provided
765 static int __verify_userptr_ops(struct vb2_queue
*q
)
767 if (!(q
->io_modes
& VB2_USERPTR
) || !q
->mem_ops
->get_userptr
||
768 !q
->mem_ops
->put_userptr
)
775 * __verify_mmap_ops() - verify that all memory operations required for
776 * MMAP queue type have been provided
778 static int __verify_mmap_ops(struct vb2_queue
*q
)
780 if (!(q
->io_modes
& VB2_MMAP
) || !q
->mem_ops
->alloc
||
781 !q
->mem_ops
->put
|| !q
->mem_ops
->mmap
)
788 * __verify_dmabuf_ops() - verify that all memory operations required for
789 * DMABUF queue type have been provided
791 static int __verify_dmabuf_ops(struct vb2_queue
*q
)
793 if (!(q
->io_modes
& VB2_DMABUF
) || !q
->mem_ops
->attach_dmabuf
||
794 !q
->mem_ops
->detach_dmabuf
|| !q
->mem_ops
->map_dmabuf
||
795 !q
->mem_ops
->unmap_dmabuf
)
802 * __verify_memory_type() - Check whether the memory type and buffer type
803 * passed to a buffer operation are compatible with the queue.
805 static int __verify_memory_type(struct vb2_queue
*q
,
806 enum v4l2_memory memory
, enum v4l2_buf_type type
)
808 if (memory
!= V4L2_MEMORY_MMAP
&& memory
!= V4L2_MEMORY_USERPTR
&&
809 memory
!= V4L2_MEMORY_DMABUF
) {
810 dprintk(1, "unsupported memory type\n");
814 if (type
!= q
->type
) {
815 dprintk(1, "requested type is incorrect\n");
820 * Make sure all the required memory ops for given memory type
823 if (memory
== V4L2_MEMORY_MMAP
&& __verify_mmap_ops(q
)) {
824 dprintk(1, "MMAP for current setup unsupported\n");
828 if (memory
== V4L2_MEMORY_USERPTR
&& __verify_userptr_ops(q
)) {
829 dprintk(1, "USERPTR for current setup unsupported\n");
833 if (memory
== V4L2_MEMORY_DMABUF
&& __verify_dmabuf_ops(q
)) {
834 dprintk(1, "DMABUF for current setup unsupported\n");
839 * Place the busy tests at the end: -EBUSY can be ignored when
840 * create_bufs is called with count == 0, but count == 0 should still
841 * do the memory and type validation.
843 if (vb2_fileio_is_active(q
)) {
844 dprintk(1, "file io in progress\n");
851 * __reqbufs() - Initiate streaming
852 * @q: videobuf2 queue
853 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
855 * Should be called from vidioc_reqbufs ioctl handler of a driver.
857 * 1) verifies streaming parameters passed from the userspace,
858 * 2) sets up the queue,
859 * 3) negotiates number of buffers and planes per buffer with the driver
860 * to be used during streaming,
861 * 4) allocates internal buffer structures (struct vb2_buffer), according to
862 * the agreed parameters,
863 * 5) for MMAP memory type, allocates actual video memory, using the
864 * memory handling/allocation routines provided during queue initialization
866 * If req->count is 0, all the memory will be freed instead.
867 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
868 * and the queue is not busy, memory will be reallocated.
870 * The return values from this function are intended to be directly returned
871 * from vidioc_reqbufs handler in driver.
873 static int __reqbufs(struct vb2_queue
*q
, struct v4l2_requestbuffers
*req
)
875 unsigned int num_buffers
, allocated_buffers
, num_planes
= 0;
879 dprintk(1, "streaming active\n");
883 if (req
->count
== 0 || q
->num_buffers
!= 0 || q
->memory
!= req
->memory
) {
885 * We already have buffers allocated, so first check if they
886 * are not in use and can be freed.
888 mutex_lock(&q
->mmap_lock
);
889 if (q
->memory
== V4L2_MEMORY_MMAP
&& __buffers_in_use(q
)) {
890 mutex_unlock(&q
->mmap_lock
);
891 dprintk(1, "memory in use, cannot free\n");
896 * Call queue_cancel to clean up any buffers in the PREPARED or
897 * QUEUED state which is possible if buffers were prepared or
898 * queued without ever calling STREAMON.
900 __vb2_queue_cancel(q
);
901 ret
= __vb2_queue_free(q
, q
->num_buffers
);
902 mutex_unlock(&q
->mmap_lock
);
907 * In case of REQBUFS(0) return immediately without calling
908 * driver's queue_setup() callback and allocating resources.
915 * Make sure the requested values and current defaults are sane.
917 num_buffers
= min_t(unsigned int, req
->count
, VIDEO_MAX_FRAME
);
918 num_buffers
= max_t(unsigned int, num_buffers
, q
->min_buffers_needed
);
919 memset(q
->plane_sizes
, 0, sizeof(q
->plane_sizes
));
920 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
921 q
->memory
= req
->memory
;
924 * Ask the driver how many buffers and planes per buffer it requires.
925 * Driver also sets the size and allocator context for each plane.
927 ret
= call_qop(q
, queue_setup
, q
, NULL
, &num_buffers
, &num_planes
,
928 q
->plane_sizes
, q
->alloc_ctx
);
932 /* Finally, allocate buffers and video memory */
933 allocated_buffers
= __vb2_queue_alloc(q
, req
->memory
, num_buffers
, num_planes
);
934 if (allocated_buffers
== 0) {
935 dprintk(1, "memory allocation failed\n");
940 * There is no point in continuing if we can't allocate the minimum
941 * number of buffers needed by this vb2_queue.
943 if (allocated_buffers
< q
->min_buffers_needed
)
947 * Check if driver can handle the allocated number of buffers.
949 if (!ret
&& allocated_buffers
< num_buffers
) {
950 num_buffers
= allocated_buffers
;
952 ret
= call_qop(q
, queue_setup
, q
, NULL
, &num_buffers
,
953 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
955 if (!ret
&& allocated_buffers
< num_buffers
)
959 * Either the driver has accepted a smaller number of buffers,
960 * or .queue_setup() returned an error
964 mutex_lock(&q
->mmap_lock
);
965 q
->num_buffers
= allocated_buffers
;
969 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
970 * from q->num_buffers.
972 __vb2_queue_free(q
, allocated_buffers
);
973 mutex_unlock(&q
->mmap_lock
);
976 mutex_unlock(&q
->mmap_lock
);
979 * Return the number of successfully allocated buffers
982 req
->count
= allocated_buffers
;
983 q
->waiting_for_buffers
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
989 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
991 * @q: videobuf2 queue
992 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
994 int vb2_reqbufs(struct vb2_queue
*q
, struct v4l2_requestbuffers
*req
)
996 int ret
= __verify_memory_type(q
, req
->memory
, req
->type
);
998 return ret
? ret
: __reqbufs(q
, req
);
1000 EXPORT_SYMBOL_GPL(vb2_reqbufs
);
1003 * __create_bufs() - Allocate buffers and any required auxiliary structs
1004 * @q: videobuf2 queue
1005 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1008 * Should be called from vidioc_create_bufs ioctl handler of a driver.
1010 * 1) verifies parameter sanity
1011 * 2) calls the .queue_setup() queue operation
1012 * 3) performs any necessary memory allocations
1014 * The return values from this function are intended to be directly returned
1015 * from vidioc_create_bufs handler in driver.
1017 static int __create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
1019 unsigned int num_planes
= 0, num_buffers
, allocated_buffers
;
1022 if (q
->num_buffers
== VIDEO_MAX_FRAME
) {
1023 dprintk(1, "maximum number of buffers already allocated\n");
1027 if (!q
->num_buffers
) {
1028 memset(q
->plane_sizes
, 0, sizeof(q
->plane_sizes
));
1029 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
1030 q
->memory
= create
->memory
;
1031 q
->waiting_for_buffers
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
1034 num_buffers
= min(create
->count
, VIDEO_MAX_FRAME
- q
->num_buffers
);
1037 * Ask the driver, whether the requested number of buffers, planes per
1038 * buffer and their sizes are acceptable
1040 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
1041 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
1045 /* Finally, allocate buffers and video memory */
1046 allocated_buffers
= __vb2_queue_alloc(q
, create
->memory
, num_buffers
,
1048 if (allocated_buffers
== 0) {
1049 dprintk(1, "memory allocation failed\n");
1054 * Check if driver can handle the so far allocated number of buffers.
1056 if (allocated_buffers
< num_buffers
) {
1057 num_buffers
= allocated_buffers
;
1060 * q->num_buffers contains the total number of buffers, that the
1061 * queue driver has set up
1063 ret
= call_qop(q
, queue_setup
, q
, &create
->format
, &num_buffers
,
1064 &num_planes
, q
->plane_sizes
, q
->alloc_ctx
);
1066 if (!ret
&& allocated_buffers
< num_buffers
)
1070 * Either the driver has accepted a smaller number of buffers,
1071 * or .queue_setup() returned an error
1075 mutex_lock(&q
->mmap_lock
);
1076 q
->num_buffers
+= allocated_buffers
;
1080 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
1081 * from q->num_buffers.
1083 __vb2_queue_free(q
, allocated_buffers
);
1084 mutex_unlock(&q
->mmap_lock
);
1087 mutex_unlock(&q
->mmap_lock
);
1090 * Return the number of successfully allocated buffers
1093 create
->count
= allocated_buffers
;
1099 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
1100 * memory and type values.
1101 * @q: videobuf2 queue
1102 * @create: creation parameters, passed from userspace to vidioc_create_bufs
1105 int vb2_create_bufs(struct vb2_queue
*q
, struct v4l2_create_buffers
*create
)
1107 int ret
= __verify_memory_type(q
, create
->memory
, create
->format
.type
);
1109 create
->index
= q
->num_buffers
;
1110 if (create
->count
== 0)
1111 return ret
!= -EBUSY
? ret
: 0;
1112 return ret
? ret
: __create_bufs(q
, create
);
1114 EXPORT_SYMBOL_GPL(vb2_create_bufs
);
1117 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
1118 * @vb: vb2_buffer to which the plane in question belongs to
1119 * @plane_no: plane number for which the address is to be returned
1121 * This function returns a kernel virtual address of a given plane if
1122 * such a mapping exist, NULL otherwise.
1124 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
)
1126 if (plane_no
> vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
1129 return call_ptr_memop(vb
, vaddr
, vb
->planes
[plane_no
].mem_priv
);
1132 EXPORT_SYMBOL_GPL(vb2_plane_vaddr
);
1135 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
1136 * @vb: vb2_buffer to which the plane in question belongs to
1137 * @plane_no: plane number for which the cookie is to be returned
1139 * This function returns an allocator specific cookie for a given plane if
1140 * available, NULL otherwise. The allocator should provide some simple static
1141 * inline function, which would convert this cookie to the allocator specific
1142 * type that can be used directly by the driver to access the buffer. This can
1143 * be for example physical address, pointer to scatter list or IOMMU mapping.
1145 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
)
1147 if (plane_no
>= vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
1150 return call_ptr_memop(vb
, cookie
, vb
->planes
[plane_no
].mem_priv
);
1152 EXPORT_SYMBOL_GPL(vb2_plane_cookie
);
1155 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
1156 * @vb: vb2_buffer returned from the driver
1157 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
1158 * VB2_BUF_STATE_ERROR if the operation finished with an error or
1159 * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
1160 * If start_streaming fails then it should return buffers with state
1161 * VB2_BUF_STATE_QUEUED to put them back into the queue.
1163 * This function should be called by the driver after a hardware operation on
1164 * a buffer is finished and the buffer may be returned to userspace. The driver
1165 * cannot use this buffer anymore until it is queued back to it by videobuf
1166 * by the means of buf_queue callback. Only buffers previously queued to the
1167 * driver by buf_queue can be passed to this function.
1169 * While streaming a buffer can only be returned in state DONE or ERROR.
1170 * The start_streaming op can also return them in case the DMA engine cannot
1171 * be started for some reason. In that case the buffers should be returned with
1174 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
)
1176 struct vb2_queue
*q
= vb
->vb2_queue
;
1177 unsigned long flags
;
1180 if (WARN_ON(vb
->state
!= VB2_BUF_STATE_ACTIVE
))
1183 if (WARN_ON(state
!= VB2_BUF_STATE_DONE
&&
1184 state
!= VB2_BUF_STATE_ERROR
&&
1185 state
!= VB2_BUF_STATE_QUEUED
))
1186 state
= VB2_BUF_STATE_ERROR
;
1188 #ifdef CONFIG_VIDEO_ADV_DEBUG
1190 * Although this is not a callback, it still does have to balance
1191 * with the buf_queue op. So update this counter manually.
1195 dprintk(4, "done processing on buffer %d, state: %d\n",
1196 vb
->v4l2_buf
.index
, state
);
1199 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1200 call_void_memop(vb
, finish
, vb
->planes
[plane
].mem_priv
);
1202 /* Add the buffer to the done buffers list */
1203 spin_lock_irqsave(&q
->done_lock
, flags
);
1205 if (state
!= VB2_BUF_STATE_QUEUED
)
1206 list_add_tail(&vb
->done_entry
, &q
->done_list
);
1207 atomic_dec(&q
->owned_by_drv_count
);
1208 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1210 if (state
== VB2_BUF_STATE_QUEUED
) {
1211 if (q
->start_streaming_called
)
1212 __enqueue_in_driver(vb
);
1216 /* Inform any processes that may be waiting for buffers */
1217 wake_up(&q
->done_wq
);
1219 EXPORT_SYMBOL_GPL(vb2_buffer_done
);
1222 * vb2_discard_done() - discard all buffers marked as DONE
1223 * @q: videobuf2 queue
1225 * This function is intended to be used with suspend/resume operations. It
1226 * discards all 'done' buffers as they would be too old to be requested after
1229 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1230 * delayed works before calling this function to make sure no buffer will be
1231 * touched by the driver and/or hardware.
1233 void vb2_discard_done(struct vb2_queue
*q
)
1235 struct vb2_buffer
*vb
;
1236 unsigned long flags
;
1238 spin_lock_irqsave(&q
->done_lock
, flags
);
1239 list_for_each_entry(vb
, &q
->done_list
, done_entry
)
1240 vb
->state
= VB2_BUF_STATE_ERROR
;
1241 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1243 EXPORT_SYMBOL_GPL(vb2_discard_done
);
1245 static void vb2_warn_zero_bytesused(struct vb2_buffer
*vb
)
1247 static bool __check_once __read_mostly
;
1252 __check_once
= true;
1255 pr_warn_once("use of bytesused == 0 is deprecated and will be removed in the future,\n");
1256 if (vb
->vb2_queue
->allow_zero_bytesused
)
1257 pr_warn_once("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
1259 pr_warn_once("use the actual size instead.\n");
1263 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
1264 * v4l2_buffer by the userspace. The caller has already verified that struct
1265 * v4l2_buffer has a valid number of planes.
1267 static void __fill_vb2_buffer(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
,
1268 struct v4l2_plane
*v4l2_planes
)
1272 if (V4L2_TYPE_IS_MULTIPLANAR(b
->type
)) {
1273 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
1274 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1275 v4l2_planes
[plane
].m
.userptr
=
1276 b
->m
.planes
[plane
].m
.userptr
;
1277 v4l2_planes
[plane
].length
=
1278 b
->m
.planes
[plane
].length
;
1281 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
1282 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1283 v4l2_planes
[plane
].m
.fd
=
1284 b
->m
.planes
[plane
].m
.fd
;
1285 v4l2_planes
[plane
].length
=
1286 b
->m
.planes
[plane
].length
;
1290 /* Fill in driver-provided information for OUTPUT types */
1291 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1293 * Will have to go up to b->length when API starts
1294 * accepting variable number of planes.
1296 * If bytesused == 0 for the output buffer, then fall
1297 * back to the full buffer size. In that case
1298 * userspace clearly never bothered to set it and
1299 * it's a safe assumption that they really meant to
1300 * use the full plane sizes.
1302 * Some drivers, e.g. old codec drivers, use bytesused == 0
1303 * as a way to indicate that streaming is finished.
1304 * In that case, the driver should use the
1305 * allow_zero_bytesused flag to keep old userspace
1306 * applications working.
1308 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1309 struct v4l2_plane
*pdst
= &v4l2_planes
[plane
];
1310 struct v4l2_plane
*psrc
= &b
->m
.planes
[plane
];
1312 if (psrc
->bytesused
== 0)
1313 vb2_warn_zero_bytesused(vb
);
1315 if (vb
->vb2_queue
->allow_zero_bytesused
)
1316 pdst
->bytesused
= psrc
->bytesused
;
1318 pdst
->bytesused
= psrc
->bytesused
?
1319 psrc
->bytesused
: pdst
->length
;
1320 pdst
->data_offset
= psrc
->data_offset
;
1325 * Single-planar buffers do not use planes array,
1326 * so fill in relevant v4l2_buffer struct fields instead.
1327 * In videobuf we use our internal V4l2_planes struct for
1328 * single-planar buffers as well, for simplicity.
1330 * If bytesused == 0 for the output buffer, then fall back
1331 * to the full buffer size as that's a sensible default.
1333 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
1334 * a way to indicate that streaming is finished. In that case,
1335 * the driver should use the allow_zero_bytesused flag to keep
1336 * old userspace applications working.
1338 if (b
->memory
== V4L2_MEMORY_USERPTR
) {
1339 v4l2_planes
[0].m
.userptr
= b
->m
.userptr
;
1340 v4l2_planes
[0].length
= b
->length
;
1343 if (b
->memory
== V4L2_MEMORY_DMABUF
) {
1344 v4l2_planes
[0].m
.fd
= b
->m
.fd
;
1345 v4l2_planes
[0].length
= b
->length
;
1348 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1349 if (b
->bytesused
== 0)
1350 vb2_warn_zero_bytesused(vb
);
1352 if (vb
->vb2_queue
->allow_zero_bytesused
)
1353 v4l2_planes
[0].bytesused
= b
->bytesused
;
1355 v4l2_planes
[0].bytesused
= b
->bytesused
?
1356 b
->bytesused
: v4l2_planes
[0].length
;
1358 v4l2_planes
[0].bytesused
= 0;
1362 /* Zero flags that the vb2 core handles */
1363 vb
->v4l2_buf
.flags
= b
->flags
& ~V4L2_BUFFER_MASK_FLAGS
;
1364 if ((vb
->vb2_queue
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) !=
1365 V4L2_BUF_FLAG_TIMESTAMP_COPY
|| !V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1367 * Non-COPY timestamps and non-OUTPUT queues will get
1368 * their timestamp and timestamp source flags from the
1371 vb
->v4l2_buf
.flags
&= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK
;
1374 if (V4L2_TYPE_IS_OUTPUT(b
->type
)) {
1376 * For output buffers mask out the timecode flag:
1377 * this will be handled later in vb2_internal_qbuf().
1378 * The 'field' is valid metadata for this output buffer
1379 * and so that needs to be copied here.
1381 vb
->v4l2_buf
.flags
&= ~V4L2_BUF_FLAG_TIMECODE
;
1382 vb
->v4l2_buf
.field
= b
->field
;
1384 /* Zero any output buffer flags as this is a capture buffer */
1385 vb
->v4l2_buf
.flags
&= ~V4L2_BUFFER_OUT_FLAGS
;
1390 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1392 static int __qbuf_mmap(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1394 __fill_vb2_buffer(vb
, b
, vb
->v4l2_planes
);
1395 return call_vb_qop(vb
, buf_prepare
, vb
);
1399 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1401 static int __qbuf_userptr(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1403 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1404 struct vb2_queue
*q
= vb
->vb2_queue
;
1408 enum dma_data_direction dma_dir
=
1409 V4L2_TYPE_IS_OUTPUT(q
->type
) ? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1410 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1412 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1413 /* Copy relevant information provided by the userspace */
1414 __fill_vb2_buffer(vb
, b
, planes
);
1416 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1417 /* Skip the plane if already verified */
1418 if (vb
->v4l2_planes
[plane
].m
.userptr
&&
1419 vb
->v4l2_planes
[plane
].m
.userptr
== planes
[plane
].m
.userptr
1420 && vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
)
1423 dprintk(3, "userspace address for plane %d changed, "
1424 "reacquiring memory\n", plane
);
1426 /* Check if the provided plane buffer is large enough */
1427 if (planes
[plane
].length
< q
->plane_sizes
[plane
]) {
1428 dprintk(1, "provided buffer size %u is less than "
1429 "setup size %u for plane %d\n",
1430 planes
[plane
].length
,
1431 q
->plane_sizes
[plane
], plane
);
1436 /* Release previously acquired memory if present */
1437 if (vb
->planes
[plane
].mem_priv
) {
1440 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1442 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1445 vb
->planes
[plane
].mem_priv
= NULL
;
1446 memset(&vb
->v4l2_planes
[plane
], 0, sizeof(struct v4l2_plane
));
1448 /* Acquire each plane's memory */
1449 mem_priv
= call_ptr_memop(vb
, get_userptr
, q
->alloc_ctx
[plane
],
1450 planes
[plane
].m
.userptr
,
1451 planes
[plane
].length
, dma_dir
);
1452 if (IS_ERR_OR_NULL(mem_priv
)) {
1453 dprintk(1, "failed acquiring userspace "
1454 "memory for plane %d\n", plane
);
1455 ret
= mem_priv
? PTR_ERR(mem_priv
) : -EINVAL
;
1458 vb
->planes
[plane
].mem_priv
= mem_priv
;
1462 * Now that everything is in order, copy relevant information
1463 * provided by userspace.
1465 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1466 vb
->v4l2_planes
[plane
] = planes
[plane
];
1470 * One or more planes changed, so we must call buf_init to do
1471 * the driver-specific initialization on the newly acquired
1472 * buffer, if provided.
1474 ret
= call_vb_qop(vb
, buf_init
, vb
);
1476 dprintk(1, "buffer initialization failed\n");
1481 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1483 dprintk(1, "buffer preparation failed\n");
1484 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1490 /* In case of errors, release planes that were already acquired */
1491 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1492 if (vb
->planes
[plane
].mem_priv
)
1493 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1494 vb
->planes
[plane
].mem_priv
= NULL
;
1495 vb
->v4l2_planes
[plane
].m
.userptr
= 0;
1496 vb
->v4l2_planes
[plane
].length
= 0;
1503 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1505 static int __qbuf_dmabuf(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1507 struct v4l2_plane planes
[VIDEO_MAX_PLANES
];
1508 struct vb2_queue
*q
= vb
->vb2_queue
;
1512 enum dma_data_direction dma_dir
=
1513 V4L2_TYPE_IS_OUTPUT(q
->type
) ? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1514 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1516 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1517 /* Copy relevant information provided by the userspace */
1518 __fill_vb2_buffer(vb
, b
, planes
);
1520 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1521 struct dma_buf
*dbuf
= dma_buf_get(planes
[plane
].m
.fd
);
1523 if (IS_ERR_OR_NULL(dbuf
)) {
1524 dprintk(1, "invalid dmabuf fd for plane %d\n",
1530 /* use DMABUF size if length is not provided */
1531 if (planes
[plane
].length
== 0)
1532 planes
[plane
].length
= dbuf
->size
;
1534 if (planes
[plane
].length
< q
->plane_sizes
[plane
]) {
1535 dprintk(1, "invalid dmabuf length for plane %d\n",
1541 /* Skip the plane if already verified */
1542 if (dbuf
== vb
->planes
[plane
].dbuf
&&
1543 vb
->v4l2_planes
[plane
].length
== planes
[plane
].length
) {
1548 dprintk(1, "buffer for plane %d changed\n", plane
);
1552 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1555 /* Release previously acquired memory if present */
1556 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
1557 memset(&vb
->v4l2_planes
[plane
], 0, sizeof(struct v4l2_plane
));
1559 /* Acquire each plane's memory */
1560 mem_priv
= call_ptr_memop(vb
, attach_dmabuf
, q
->alloc_ctx
[plane
],
1561 dbuf
, planes
[plane
].length
, dma_dir
);
1562 if (IS_ERR(mem_priv
)) {
1563 dprintk(1, "failed to attach dmabuf\n");
1564 ret
= PTR_ERR(mem_priv
);
1569 vb
->planes
[plane
].dbuf
= dbuf
;
1570 vb
->planes
[plane
].mem_priv
= mem_priv
;
1573 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1574 * really we want to do this just before the DMA, not while queueing
1577 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1578 ret
= call_memop(vb
, map_dmabuf
, vb
->planes
[plane
].mem_priv
);
1580 dprintk(1, "failed to map dmabuf for plane %d\n",
1584 vb
->planes
[plane
].dbuf_mapped
= 1;
1588 * Now that everything is in order, copy relevant information
1589 * provided by userspace.
1591 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1592 vb
->v4l2_planes
[plane
] = planes
[plane
];
1596 * Call driver-specific initialization on the newly acquired buffer,
1599 ret
= call_vb_qop(vb
, buf_init
, vb
);
1601 dprintk(1, "buffer initialization failed\n");
1606 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1608 dprintk(1, "buffer preparation failed\n");
1609 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1615 /* In case of errors, release planes that were already acquired */
1616 __vb2_buf_dmabuf_put(vb
);
1622 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1624 static void __enqueue_in_driver(struct vb2_buffer
*vb
)
1626 struct vb2_queue
*q
= vb
->vb2_queue
;
1629 vb
->state
= VB2_BUF_STATE_ACTIVE
;
1630 atomic_inc(&q
->owned_by_drv_count
);
1633 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1634 call_void_memop(vb
, prepare
, vb
->planes
[plane
].mem_priv
);
1636 call_void_vb_qop(vb
, buf_queue
, vb
);
1639 static int __buf_prepare(struct vb2_buffer
*vb
, const struct v4l2_buffer
*b
)
1641 struct vb2_queue
*q
= vb
->vb2_queue
;
1644 ret
= __verify_length(vb
, b
);
1646 dprintk(1, "plane parameters verification failed: %d\n", ret
);
1649 if (b
->field
== V4L2_FIELD_ALTERNATE
&& V4L2_TYPE_IS_OUTPUT(q
->type
)) {
1651 * If the format's field is ALTERNATE, then the buffer's field
1652 * should be either TOP or BOTTOM, not ALTERNATE since that
1653 * makes no sense. The driver has to know whether the
1654 * buffer represents a top or a bottom field in order to
1655 * program any DMA correctly. Using ALTERNATE is wrong, since
1656 * that just says that it is either a top or a bottom field,
1657 * but not which of the two it is.
1659 dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
1664 dprintk(1, "fatal error occurred on queue\n");
1668 vb
->state
= VB2_BUF_STATE_PREPARING
;
1669 vb
->v4l2_buf
.timestamp
.tv_sec
= 0;
1670 vb
->v4l2_buf
.timestamp
.tv_usec
= 0;
1671 vb
->v4l2_buf
.sequence
= 0;
1673 switch (q
->memory
) {
1674 case V4L2_MEMORY_MMAP
:
1675 ret
= __qbuf_mmap(vb
, b
);
1677 case V4L2_MEMORY_USERPTR
:
1678 down_read(¤t
->mm
->mmap_sem
);
1679 ret
= __qbuf_userptr(vb
, b
);
1680 up_read(¤t
->mm
->mmap_sem
);
1682 case V4L2_MEMORY_DMABUF
:
1683 ret
= __qbuf_dmabuf(vb
, b
);
1686 WARN(1, "Invalid queue type\n");
1691 dprintk(1, "buffer preparation failed: %d\n", ret
);
1692 vb
->state
= ret
? VB2_BUF_STATE_DEQUEUED
: VB2_BUF_STATE_PREPARED
;
1697 static int vb2_queue_or_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
,
1700 if (b
->type
!= q
->type
) {
1701 dprintk(1, "%s: invalid buffer type\n", opname
);
1705 if (b
->index
>= q
->num_buffers
) {
1706 dprintk(1, "%s: buffer index out of range\n", opname
);
1710 if (q
->bufs
[b
->index
] == NULL
) {
1711 /* Should never happen */
1712 dprintk(1, "%s: buffer is NULL\n", opname
);
1716 if (b
->memory
!= q
->memory
) {
1717 dprintk(1, "%s: invalid memory type\n", opname
);
1721 return __verify_planes_array(q
->bufs
[b
->index
], b
);
1725 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1726 * @q: videobuf2 queue
1727 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1730 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1732 * 1) verifies the passed buffer,
1733 * 2) calls buf_prepare callback in the driver (if provided), in which
1734 * driver-specific buffer initialization can be performed,
1736 * The return values from this function are intended to be directly returned
1737 * from vidioc_prepare_buf handler in driver.
1739 int vb2_prepare_buf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1741 struct vb2_buffer
*vb
;
1744 if (vb2_fileio_is_active(q
)) {
1745 dprintk(1, "file io in progress\n");
1749 ret
= vb2_queue_or_prepare_buf(q
, b
, "prepare_buf");
1753 vb
= q
->bufs
[b
->index
];
1754 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1755 dprintk(1, "invalid buffer state %d\n",
1760 ret
= __buf_prepare(vb
, b
);
1762 /* Fill buffer information for the userspace */
1763 __fill_v4l2_buffer(vb
, b
);
1765 dprintk(1, "prepare of buffer %d succeeded\n", vb
->v4l2_buf
.index
);
1769 EXPORT_SYMBOL_GPL(vb2_prepare_buf
);
1772 * vb2_start_streaming() - Attempt to start streaming.
1773 * @q: videobuf2 queue
1775 * Attempt to start streaming. When this function is called there must be
1776 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1777 * number of buffers required for the DMA engine to function). If the
1778 * @start_streaming op fails it is supposed to return all the driver-owned
1779 * buffers back to vb2 in state QUEUED. Check if that happened and if
1780 * not warn and reclaim them forcefully.
1782 static int vb2_start_streaming(struct vb2_queue
*q
)
1784 struct vb2_buffer
*vb
;
1788 * If any buffers were queued before streamon,
1789 * we can now pass them to driver for processing.
1791 list_for_each_entry(vb
, &q
->queued_list
, queued_entry
)
1792 __enqueue_in_driver(vb
);
1794 /* Tell the driver to start streaming */
1795 q
->start_streaming_called
= 1;
1796 ret
= call_qop(q
, start_streaming
, q
,
1797 atomic_read(&q
->owned_by_drv_count
));
1801 q
->start_streaming_called
= 0;
1803 dprintk(1, "driver refused to start streaming\n");
1805 * If you see this warning, then the driver isn't cleaning up properly
1806 * after a failed start_streaming(). See the start_streaming()
1807 * documentation in videobuf2-core.h for more information how buffers
1808 * should be returned to vb2 in start_streaming().
1810 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1814 * Forcefully reclaim buffers if the driver did not
1815 * correctly return them to vb2.
1817 for (i
= 0; i
< q
->num_buffers
; ++i
) {
1819 if (vb
->state
== VB2_BUF_STATE_ACTIVE
)
1820 vb2_buffer_done(vb
, VB2_BUF_STATE_QUEUED
);
1822 /* Must be zero now */
1823 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1826 * If done_list is not empty, then start_streaming() didn't call
1827 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1830 WARN_ON(!list_empty(&q
->done_list
));
1834 static int vb2_internal_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1836 int ret
= vb2_queue_or_prepare_buf(q
, b
, "qbuf");
1837 struct vb2_buffer
*vb
;
1842 vb
= q
->bufs
[b
->index
];
1844 switch (vb
->state
) {
1845 case VB2_BUF_STATE_DEQUEUED
:
1846 ret
= __buf_prepare(vb
, b
);
1850 case VB2_BUF_STATE_PREPARED
:
1852 case VB2_BUF_STATE_PREPARING
:
1853 dprintk(1, "buffer still being prepared\n");
1856 dprintk(1, "invalid buffer state %d\n", vb
->state
);
1861 * Add to the queued buffers list, a buffer will stay on it until
1862 * dequeued in dqbuf.
1864 list_add_tail(&vb
->queued_entry
, &q
->queued_list
);
1866 q
->waiting_for_buffers
= false;
1867 vb
->state
= VB2_BUF_STATE_QUEUED
;
1868 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
1870 * For output buffers copy the timestamp if needed,
1871 * and the timecode field and flag if needed.
1873 if ((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
1874 V4L2_BUF_FLAG_TIMESTAMP_COPY
)
1875 vb
->v4l2_buf
.timestamp
= b
->timestamp
;
1876 vb
->v4l2_buf
.flags
|= b
->flags
& V4L2_BUF_FLAG_TIMECODE
;
1877 if (b
->flags
& V4L2_BUF_FLAG_TIMECODE
)
1878 vb
->v4l2_buf
.timecode
= b
->timecode
;
1882 * If already streaming, give the buffer to driver for processing.
1883 * If not, the buffer will be given to driver on next streamon.
1885 if (q
->start_streaming_called
)
1886 __enqueue_in_driver(vb
);
1888 /* Fill buffer information for the userspace */
1889 __fill_v4l2_buffer(vb
, b
);
1892 * If streamon has been called, and we haven't yet called
1893 * start_streaming() since not enough buffers were queued, and
1894 * we now have reached the minimum number of queued buffers,
1895 * then we can finally call start_streaming().
1897 if (q
->streaming
&& !q
->start_streaming_called
&&
1898 q
->queued_count
>= q
->min_buffers_needed
) {
1899 ret
= vb2_start_streaming(q
);
1904 dprintk(1, "qbuf of buffer %d succeeded\n", vb
->v4l2_buf
.index
);
1909 * vb2_qbuf() - Queue a buffer from userspace
1910 * @q: videobuf2 queue
1911 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1914 * Should be called from vidioc_qbuf ioctl handler of a driver.
1916 * 1) verifies the passed buffer,
1917 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1918 * which driver-specific buffer initialization can be performed,
1919 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1920 * callback for processing.
1922 * The return values from this function are intended to be directly returned
1923 * from vidioc_qbuf handler in driver.
1925 int vb2_qbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
)
1927 if (vb2_fileio_is_active(q
)) {
1928 dprintk(1, "file io in progress\n");
1932 return vb2_internal_qbuf(q
, b
);
1934 EXPORT_SYMBOL_GPL(vb2_qbuf
);
1937 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1940 * Will sleep if required for nonblocking == false.
1942 static int __vb2_wait_for_done_vb(struct vb2_queue
*q
, int nonblocking
)
1945 * All operations on vb_done_list are performed under done_lock
1946 * spinlock protection. However, buffers may be removed from
1947 * it and returned to userspace only while holding both driver's
1948 * lock and the done_lock spinlock. Thus we can be sure that as
1949 * long as we hold the driver's lock, the list will remain not
1950 * empty if list_empty() check succeeds.
1956 if (!q
->streaming
) {
1957 dprintk(1, "streaming off, will not wait for buffers\n");
1962 dprintk(1, "Queue in error state, will not wait for buffers\n");
1966 if (q
->last_buffer_dequeued
) {
1967 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1971 if (!list_empty(&q
->done_list
)) {
1973 * Found a buffer that we were waiting for.
1979 dprintk(1, "nonblocking and no buffers to dequeue, "
1985 * We are streaming and blocking, wait for another buffer to
1986 * become ready or for streamoff. Driver's lock is released to
1987 * allow streamoff or qbuf to be called while waiting.
1989 call_void_qop(q
, wait_prepare
, q
);
1992 * All locks have been released, it is safe to sleep now.
1994 dprintk(3, "will sleep waiting for buffers\n");
1995 ret
= wait_event_interruptible(q
->done_wq
,
1996 !list_empty(&q
->done_list
) || !q
->streaming
||
2000 * We need to reevaluate both conditions again after reacquiring
2001 * the locks or return an error if one occurred.
2003 call_void_qop(q
, wait_finish
, q
);
2005 dprintk(1, "sleep was interrupted\n");
2013 * __vb2_get_done_vb() - get a buffer ready for dequeuing
2015 * Will sleep if required for nonblocking == false.
2017 static int __vb2_get_done_vb(struct vb2_queue
*q
, struct vb2_buffer
**vb
,
2018 struct v4l2_buffer
*b
, int nonblocking
)
2020 unsigned long flags
;
2024 * Wait for at least one buffer to become available on the done_list.
2026 ret
= __vb2_wait_for_done_vb(q
, nonblocking
);
2031 * Driver's lock has been held since we last verified that done_list
2032 * is not empty, so no need for another list_empty(done_list) check.
2034 spin_lock_irqsave(&q
->done_lock
, flags
);
2035 *vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
, done_entry
);
2037 * Only remove the buffer from done_list if v4l2_buffer can handle all
2040 ret
= __verify_planes_array(*vb
, b
);
2042 list_del(&(*vb
)->done_entry
);
2043 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2049 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
2050 * @q: videobuf2 queue
2052 * This function will wait until all buffers that have been given to the driver
2053 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
2054 * wait_prepare, wait_finish pair. It is intended to be called with all locks
2055 * taken, for example from stop_streaming() callback.
2057 int vb2_wait_for_all_buffers(struct vb2_queue
*q
)
2059 if (!q
->streaming
) {
2060 dprintk(1, "streaming off, will not wait for buffers\n");
2064 if (q
->start_streaming_called
)
2065 wait_event(q
->done_wq
, !atomic_read(&q
->owned_by_drv_count
));
2068 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers
);
2071 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
2073 static void __vb2_dqbuf(struct vb2_buffer
*vb
)
2075 struct vb2_queue
*q
= vb
->vb2_queue
;
2078 /* nothing to do if the buffer is already dequeued */
2079 if (vb
->state
== VB2_BUF_STATE_DEQUEUED
)
2082 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
2084 /* unmap DMABUF buffer */
2085 if (q
->memory
== V4L2_MEMORY_DMABUF
)
2086 for (i
= 0; i
< vb
->num_planes
; ++i
) {
2087 if (!vb
->planes
[i
].dbuf_mapped
)
2089 call_void_memop(vb
, unmap_dmabuf
, vb
->planes
[i
].mem_priv
);
2090 vb
->planes
[i
].dbuf_mapped
= 0;
2094 static int vb2_internal_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
2096 struct vb2_buffer
*vb
= NULL
;
2099 if (b
->type
!= q
->type
) {
2100 dprintk(1, "invalid buffer type\n");
2103 ret
= __vb2_get_done_vb(q
, &vb
, b
, nonblocking
);
2107 switch (vb
->state
) {
2108 case VB2_BUF_STATE_DONE
:
2109 dprintk(3, "returning done buffer\n");
2111 case VB2_BUF_STATE_ERROR
:
2112 dprintk(3, "returning done buffer with errors\n");
2115 dprintk(1, "invalid buffer state\n");
2119 call_void_vb_qop(vb
, buf_finish
, vb
);
2121 /* Fill buffer information for the userspace */
2122 __fill_v4l2_buffer(vb
, b
);
2123 /* Remove from videobuf queue */
2124 list_del(&vb
->queued_entry
);
2126 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) &&
2127 vb
->v4l2_buf
.flags
& V4L2_BUF_FLAG_LAST
)
2128 q
->last_buffer_dequeued
= true;
2129 /* go back to dequeued state */
2132 dprintk(1, "dqbuf of buffer %d, with state %d\n",
2133 vb
->v4l2_buf
.index
, vb
->state
);
2139 * vb2_dqbuf() - Dequeue a buffer to the userspace
2140 * @q: videobuf2 queue
2141 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
2143 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
2144 * buffers ready for dequeuing are present. Normally the driver
2145 * would be passing (file->f_flags & O_NONBLOCK) here
2147 * Should be called from vidioc_dqbuf ioctl handler of a driver.
2149 * 1) verifies the passed buffer,
2150 * 2) calls buf_finish callback in the driver (if provided), in which
2151 * driver can perform any additional operations that may be required before
2152 * returning the buffer to userspace, such as cache sync,
2153 * 3) the buffer struct members are filled with relevant information for
2156 * The return values from this function are intended to be directly returned
2157 * from vidioc_dqbuf handler in driver.
2159 int vb2_dqbuf(struct vb2_queue
*q
, struct v4l2_buffer
*b
, bool nonblocking
)
2161 if (vb2_fileio_is_active(q
)) {
2162 dprintk(1, "file io in progress\n");
2165 return vb2_internal_dqbuf(q
, b
, nonblocking
);
2167 EXPORT_SYMBOL_GPL(vb2_dqbuf
);
2170 * __vb2_queue_cancel() - cancel and stop (pause) streaming
2172 * Removes all queued buffers from driver's queue and all buffers queued by
2173 * userspace from videobuf's queue. Returns to state after reqbufs.
2175 static void __vb2_queue_cancel(struct vb2_queue
*q
)
2180 * Tell driver to stop all transactions and release all queued
2183 if (q
->start_streaming_called
)
2184 call_void_qop(q
, stop_streaming
, q
);
2187 * If you see this warning, then the driver isn't cleaning up properly
2188 * in stop_streaming(). See the stop_streaming() documentation in
2189 * videobuf2-core.h for more information how buffers should be returned
2190 * to vb2 in stop_streaming().
2192 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
2193 for (i
= 0; i
< q
->num_buffers
; ++i
)
2194 if (q
->bufs
[i
]->state
== VB2_BUF_STATE_ACTIVE
)
2195 vb2_buffer_done(q
->bufs
[i
], VB2_BUF_STATE_ERROR
);
2196 /* Must be zero now */
2197 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
2201 q
->start_streaming_called
= 0;
2202 q
->queued_count
= 0;
2206 * Remove all buffers from videobuf's list...
2208 INIT_LIST_HEAD(&q
->queued_list
);
2210 * ...and done list; userspace will not receive any buffers it
2211 * has not already dequeued before initiating cancel.
2213 INIT_LIST_HEAD(&q
->done_list
);
2214 atomic_set(&q
->owned_by_drv_count
, 0);
2215 wake_up_all(&q
->done_wq
);
2218 * Reinitialize all buffers for next use.
2219 * Make sure to call buf_finish for any queued buffers. Normally
2220 * that's done in dqbuf, but that's not going to happen when we
2221 * cancel the whole queue. Note: this code belongs here, not in
2222 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
2223 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
2224 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
2226 for (i
= 0; i
< q
->num_buffers
; ++i
) {
2227 struct vb2_buffer
*vb
= q
->bufs
[i
];
2229 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
2230 vb
->state
= VB2_BUF_STATE_PREPARED
;
2231 call_void_vb_qop(vb
, buf_finish
, vb
);
2237 static int vb2_internal_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2241 if (type
!= q
->type
) {
2242 dprintk(1, "invalid stream type\n");
2247 dprintk(3, "already streaming\n");
2251 if (!q
->num_buffers
) {
2252 dprintk(1, "no buffers have been allocated\n");
2256 if (q
->num_buffers
< q
->min_buffers_needed
) {
2257 dprintk(1, "need at least %u allocated buffers\n",
2258 q
->min_buffers_needed
);
2263 * Tell driver to start streaming provided sufficient buffers
2266 if (q
->queued_count
>= q
->min_buffers_needed
) {
2267 ret
= vb2_start_streaming(q
);
2269 __vb2_queue_cancel(q
);
2276 dprintk(3, "successful\n");
2281 * vb2_queue_error() - signal a fatal error on the queue
2282 * @q: videobuf2 queue
2284 * Flag that a fatal unrecoverable error has occurred and wake up all processes
2285 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
2286 * buffers will return -EIO.
2288 * The error flag will be cleared when cancelling the queue, either from
2289 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
2290 * function before starting the stream, otherwise the error flag will remain set
2291 * until the queue is released when closing the device node.
2293 void vb2_queue_error(struct vb2_queue
*q
)
2297 wake_up_all(&q
->done_wq
);
2299 EXPORT_SYMBOL_GPL(vb2_queue_error
);
2302 * vb2_streamon - start streaming
2303 * @q: videobuf2 queue
2304 * @type: type argument passed from userspace to vidioc_streamon handler
2306 * Should be called from vidioc_streamon handler of a driver.
2308 * 1) verifies current state
2309 * 2) passes any previously queued buffers to the driver and starts streaming
2311 * The return values from this function are intended to be directly returned
2312 * from vidioc_streamon handler in the driver.
2314 int vb2_streamon(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2316 if (vb2_fileio_is_active(q
)) {
2317 dprintk(1, "file io in progress\n");
2320 return vb2_internal_streamon(q
, type
);
2322 EXPORT_SYMBOL_GPL(vb2_streamon
);
2324 static int vb2_internal_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2326 if (type
!= q
->type
) {
2327 dprintk(1, "invalid stream type\n");
2332 * Cancel will pause streaming and remove all buffers from the driver
2333 * and videobuf, effectively returning control over them to userspace.
2335 * Note that we do this even if q->streaming == 0: if you prepare or
2336 * queue buffers, and then call streamoff without ever having called
2337 * streamon, you would still expect those buffers to be returned to
2338 * their normal dequeued state.
2340 __vb2_queue_cancel(q
);
2341 q
->waiting_for_buffers
= !V4L2_TYPE_IS_OUTPUT(q
->type
);
2342 q
->last_buffer_dequeued
= false;
2344 dprintk(3, "successful\n");
2349 * vb2_streamoff - stop streaming
2350 * @q: videobuf2 queue
2351 * @type: type argument passed from userspace to vidioc_streamoff handler
2353 * Should be called from vidioc_streamoff handler of a driver.
2355 * 1) verifies current state,
2356 * 2) stop streaming and dequeues any queued buffers, including those previously
2357 * passed to the driver (after waiting for the driver to finish).
2359 * This call can be used for pausing playback.
2360 * The return values from this function are intended to be directly returned
2361 * from vidioc_streamoff handler in the driver
2363 int vb2_streamoff(struct vb2_queue
*q
, enum v4l2_buf_type type
)
2365 if (vb2_fileio_is_active(q
)) {
2366 dprintk(1, "file io in progress\n");
2369 return vb2_internal_streamoff(q
, type
);
2371 EXPORT_SYMBOL_GPL(vb2_streamoff
);
2374 * __find_plane_by_offset() - find plane associated with the given offset off
2376 static int __find_plane_by_offset(struct vb2_queue
*q
, unsigned long off
,
2377 unsigned int *_buffer
, unsigned int *_plane
)
2379 struct vb2_buffer
*vb
;
2380 unsigned int buffer
, plane
;
2383 * Go over all buffers and their planes, comparing the given offset
2384 * with an offset assigned to each plane. If a match is found,
2385 * return its buffer and plane numbers.
2387 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
2388 vb
= q
->bufs
[buffer
];
2390 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
2391 if (vb
->v4l2_planes
[plane
].m
.mem_offset
== off
) {
2403 * vb2_expbuf() - Export a buffer as a file descriptor
2404 * @q: videobuf2 queue
2405 * @eb: export buffer structure passed from userspace to vidioc_expbuf
2408 * The return values from this function are intended to be directly returned
2409 * from vidioc_expbuf handler in driver.
2411 int vb2_expbuf(struct vb2_queue
*q
, struct v4l2_exportbuffer
*eb
)
2413 struct vb2_buffer
*vb
= NULL
;
2414 struct vb2_plane
*vb_plane
;
2416 struct dma_buf
*dbuf
;
2418 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2419 dprintk(1, "queue is not currently set up for mmap\n");
2423 if (!q
->mem_ops
->get_dmabuf
) {
2424 dprintk(1, "queue does not support DMA buffer exporting\n");
2428 if (eb
->flags
& ~(O_CLOEXEC
| O_ACCMODE
)) {
2429 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2433 if (eb
->type
!= q
->type
) {
2434 dprintk(1, "invalid buffer type\n");
2438 if (eb
->index
>= q
->num_buffers
) {
2439 dprintk(1, "buffer index out of range\n");
2443 vb
= q
->bufs
[eb
->index
];
2445 if (eb
->plane
>= vb
->num_planes
) {
2446 dprintk(1, "buffer plane out of range\n");
2450 if (vb2_fileio_is_active(q
)) {
2451 dprintk(1, "expbuf: file io in progress\n");
2455 vb_plane
= &vb
->planes
[eb
->plane
];
2457 dbuf
= call_ptr_memop(vb
, get_dmabuf
, vb_plane
->mem_priv
, eb
->flags
& O_ACCMODE
);
2458 if (IS_ERR_OR_NULL(dbuf
)) {
2459 dprintk(1, "failed to export buffer %d, plane %d\n",
2460 eb
->index
, eb
->plane
);
2464 ret
= dma_buf_fd(dbuf
, eb
->flags
& ~O_ACCMODE
);
2466 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2467 eb
->index
, eb
->plane
, ret
);
2472 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2473 eb
->index
, eb
->plane
, ret
);
2478 EXPORT_SYMBOL_GPL(vb2_expbuf
);
2481 * vb2_mmap() - map video buffers into application address space
2482 * @q: videobuf2 queue
2483 * @vma: vma passed to the mmap file operation handler in the driver
2485 * Should be called from mmap file operation handler of a driver.
2486 * This function maps one plane of one of the available video buffers to
2487 * userspace. To map whole video memory allocated on reqbufs, this function
2488 * has to be called once per each plane per each buffer previously allocated.
2490 * When the userspace application calls mmap, it passes to it an offset returned
2491 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2492 * a "cookie", which is then used to identify the plane to be mapped.
2493 * This function finds a plane with a matching offset and a mapping is performed
2494 * by the means of a provided memory operation.
2496 * The return values from this function are intended to be directly returned
2497 * from the mmap handler in driver.
2499 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
)
2501 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
2502 struct vb2_buffer
*vb
;
2503 unsigned int buffer
= 0, plane
= 0;
2505 unsigned long length
;
2507 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2508 dprintk(1, "queue is not currently set up for mmap\n");
2513 * Check memory area access mode.
2515 if (!(vma
->vm_flags
& VM_SHARED
)) {
2516 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2519 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
2520 if (!(vma
->vm_flags
& VM_WRITE
)) {
2521 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2525 if (!(vma
->vm_flags
& VM_READ
)) {
2526 dprintk(1, "invalid vma flags, VM_READ needed\n");
2530 if (vb2_fileio_is_active(q
)) {
2531 dprintk(1, "mmap: file io in progress\n");
2536 * Find the plane corresponding to the offset passed by userspace.
2538 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2542 vb
= q
->bufs
[buffer
];
2545 * MMAP requires page_aligned buffers.
2546 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2547 * so, we need to do the same here.
2549 length
= PAGE_ALIGN(vb
->v4l2_planes
[plane
].length
);
2550 if (length
< (vma
->vm_end
- vma
->vm_start
)) {
2552 "MMAP invalid, as it would overflow buffer length\n");
2556 mutex_lock(&q
->mmap_lock
);
2557 ret
= call_memop(vb
, mmap
, vb
->planes
[plane
].mem_priv
, vma
);
2558 mutex_unlock(&q
->mmap_lock
);
2562 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer
, plane
);
2565 EXPORT_SYMBOL_GPL(vb2_mmap
);
2568 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
2571 unsigned long pgoff
,
2572 unsigned long flags
)
2574 unsigned long off
= pgoff
<< PAGE_SHIFT
;
2575 struct vb2_buffer
*vb
;
2576 unsigned int buffer
, plane
;
2580 if (q
->memory
!= V4L2_MEMORY_MMAP
) {
2581 dprintk(1, "queue is not currently set up for mmap\n");
2586 * Find the plane corresponding to the offset passed by userspace.
2588 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2592 vb
= q
->bufs
[buffer
];
2594 vaddr
= vb2_plane_vaddr(vb
, plane
);
2595 return vaddr
? (unsigned long)vaddr
: -EINVAL
;
2597 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area
);
2600 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
);
2601 static int __vb2_cleanup_fileio(struct vb2_queue
*q
);
2604 * vb2_poll() - implements poll userspace operation
2605 * @q: videobuf2 queue
2606 * @file: file argument passed to the poll file operation handler
2607 * @wait: wait argument passed to the poll file operation handler
2609 * This function implements poll file operation handler for a driver.
2610 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2611 * be informed that the file descriptor of a video device is available for
2613 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2614 * will be reported as available for writing.
2616 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2619 * The return values from this function are intended to be directly returned
2620 * from poll handler in driver.
2622 unsigned int vb2_poll(struct vb2_queue
*q
, struct file
*file
, poll_table
*wait
)
2624 struct video_device
*vfd
= video_devdata(file
);
2625 unsigned long req_events
= poll_requested_events(wait
);
2626 struct vb2_buffer
*vb
= NULL
;
2627 unsigned int res
= 0;
2628 unsigned long flags
;
2630 if (test_bit(V4L2_FL_USES_V4L2_FH
, &vfd
->flags
)) {
2631 struct v4l2_fh
*fh
= file
->private_data
;
2633 if (v4l2_event_pending(fh
))
2635 else if (req_events
& POLLPRI
)
2636 poll_wait(file
, &fh
->wait
, wait
);
2639 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLIN
| POLLRDNORM
)))
2641 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && !(req_events
& (POLLOUT
| POLLWRNORM
)))
2645 * Start file I/O emulator only if streaming API has not been used yet.
2647 if (q
->num_buffers
== 0 && !vb2_fileio_is_active(q
)) {
2648 if (!V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_READ
) &&
2649 (req_events
& (POLLIN
| POLLRDNORM
))) {
2650 if (__vb2_init_fileio(q
, 1))
2651 return res
| POLLERR
;
2653 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && (q
->io_modes
& VB2_WRITE
) &&
2654 (req_events
& (POLLOUT
| POLLWRNORM
))) {
2655 if (__vb2_init_fileio(q
, 0))
2656 return res
| POLLERR
;
2658 * Write to OUTPUT queue can be done immediately.
2660 return res
| POLLOUT
| POLLWRNORM
;
2665 * There is nothing to wait for if the queue isn't streaming, or if the
2666 * error flag is set.
2668 if (!vb2_is_streaming(q
) || q
->error
)
2669 return res
| POLLERR
;
2671 * For compatibility with vb1: if QBUF hasn't been called yet, then
2672 * return POLLERR as well. This only affects capture queues, output
2673 * queues will always initialize waiting_for_buffers to false.
2675 if (q
->waiting_for_buffers
)
2676 return res
| POLLERR
;
2679 * For output streams you can write as long as there are fewer buffers
2680 * queued than there are buffers available.
2682 if (V4L2_TYPE_IS_OUTPUT(q
->type
) && q
->queued_count
< q
->num_buffers
)
2683 return res
| POLLOUT
| POLLWRNORM
;
2685 if (list_empty(&q
->done_list
)) {
2687 * If the last buffer was dequeued from a capture queue,
2688 * return immediately. DQBUF will return -EPIPE.
2690 if (q
->last_buffer_dequeued
)
2691 return res
| POLLIN
| POLLRDNORM
;
2693 poll_wait(file
, &q
->done_wq
, wait
);
2697 * Take first buffer available for dequeuing.
2699 spin_lock_irqsave(&q
->done_lock
, flags
);
2700 if (!list_empty(&q
->done_list
))
2701 vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
,
2703 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2705 if (vb
&& (vb
->state
== VB2_BUF_STATE_DONE
2706 || vb
->state
== VB2_BUF_STATE_ERROR
)) {
2707 return (V4L2_TYPE_IS_OUTPUT(q
->type
)) ?
2708 res
| POLLOUT
| POLLWRNORM
:
2709 res
| POLLIN
| POLLRDNORM
;
2713 EXPORT_SYMBOL_GPL(vb2_poll
);
2716 * vb2_queue_init() - initialize a videobuf2 queue
2717 * @q: videobuf2 queue; this structure should be allocated in driver
2719 * The vb2_queue structure should be allocated by the driver. The driver is
2720 * responsible of clearing it's content and setting initial values for some
2721 * required entries before calling this function.
2722 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2723 * to the struct vb2_queue description in include/media/videobuf2-core.h
2724 * for more information.
2726 int vb2_queue_init(struct vb2_queue
*q
)
2733 WARN_ON(!q
->mem_ops
) ||
2734 WARN_ON(!q
->type
) ||
2735 WARN_ON(!q
->io_modes
) ||
2736 WARN_ON(!q
->ops
->queue_setup
) ||
2737 WARN_ON(!q
->ops
->buf_queue
) ||
2738 WARN_ON(q
->timestamp_flags
&
2739 ~(V4L2_BUF_FLAG_TIMESTAMP_MASK
|
2740 V4L2_BUF_FLAG_TSTAMP_SRC_MASK
)))
2743 /* Warn that the driver should choose an appropriate timestamp type */
2744 WARN_ON((q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
2745 V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN
);
2747 INIT_LIST_HEAD(&q
->queued_list
);
2748 INIT_LIST_HEAD(&q
->done_list
);
2749 spin_lock_init(&q
->done_lock
);
2750 mutex_init(&q
->mmap_lock
);
2751 init_waitqueue_head(&q
->done_wq
);
2753 if (q
->buf_struct_size
== 0)
2754 q
->buf_struct_size
= sizeof(struct vb2_buffer
);
2758 EXPORT_SYMBOL_GPL(vb2_queue_init
);
2761 * vb2_queue_release() - stop streaming, release the queue and free memory
2762 * @q: videobuf2 queue
2764 * This function stops streaming and performs necessary clean ups, including
2765 * freeing video buffer memory. The driver is responsible for freeing
2766 * the vb2_queue structure itself.
2768 void vb2_queue_release(struct vb2_queue
*q
)
2770 __vb2_cleanup_fileio(q
);
2771 __vb2_queue_cancel(q
);
2772 mutex_lock(&q
->mmap_lock
);
2773 __vb2_queue_free(q
, q
->num_buffers
);
2774 mutex_unlock(&q
->mmap_lock
);
2776 EXPORT_SYMBOL_GPL(vb2_queue_release
);
2779 * struct vb2_fileio_buf - buffer context used by file io emulator
2781 * vb2 provides a compatibility layer and emulator of file io (read and
2782 * write) calls on top of streaming API. This structure is used for
2783 * tracking context related to the buffers.
2785 struct vb2_fileio_buf
{
2789 unsigned int queued
:1;
2793 * struct vb2_fileio_data - queue context used by file io emulator
2795 * @cur_index: the index of the buffer currently being read from or
2796 * written to. If equal to q->num_buffers then a new buffer
2798 * @initial_index: in the read() case all buffers are queued up immediately
2799 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2800 * buffers. However, in the write() case no buffers are initially
2801 * queued, instead whenever a buffer is full it is queued up by
2802 * __vb2_perform_fileio(). Only once all available buffers have
2803 * been queued up will __vb2_perform_fileio() start to dequeue
2804 * buffers. This means that initially __vb2_perform_fileio()
2805 * needs to know what buffer index to use when it is queuing up
2806 * the buffers for the first time. That initial index is stored
2807 * in this field. Once it is equal to q->num_buffers all
2808 * available buffers have been queued and __vb2_perform_fileio()
2809 * should start the normal dequeue/queue cycle.
2811 * vb2 provides a compatibility layer and emulator of file io (read and
2812 * write) calls on top of streaming API. For proper operation it required
2813 * this structure to save the driver state between each call of the read
2814 * or write function.
2816 struct vb2_fileio_data
{
2817 struct v4l2_requestbuffers req
;
2818 struct v4l2_plane p
;
2819 struct v4l2_buffer b
;
2820 struct vb2_fileio_buf bufs
[VIDEO_MAX_FRAME
];
2821 unsigned int cur_index
;
2822 unsigned int initial_index
;
2823 unsigned int q_count
;
2824 unsigned int dq_count
;
2825 unsigned read_once
:1;
2826 unsigned write_immediately
:1;
2830 * __vb2_init_fileio() - initialize file io emulator
2831 * @q: videobuf2 queue
2832 * @read: mode selector (1 means read, 0 means write)
2834 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
)
2836 struct vb2_fileio_data
*fileio
;
2838 unsigned int count
= 0;
2843 if (WARN_ON((read
&& !(q
->io_modes
& VB2_READ
)) ||
2844 (!read
&& !(q
->io_modes
& VB2_WRITE
))))
2848 * Check if device supports mapping buffers to kernel virtual space.
2850 if (!q
->mem_ops
->vaddr
)
2854 * Check if streaming api has not been already activated.
2856 if (q
->streaming
|| q
->num_buffers
> 0)
2860 * Start with count 1, driver can increase it in queue_setup()
2864 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2865 (read
) ? "read" : "write", count
, q
->fileio_read_once
,
2866 q
->fileio_write_immediately
);
2868 fileio
= kzalloc(sizeof(struct vb2_fileio_data
), GFP_KERNEL
);
2872 fileio
->read_once
= q
->fileio_read_once
;
2873 fileio
->write_immediately
= q
->fileio_write_immediately
;
2876 * Request buffers and use MMAP type to force driver
2877 * to allocate buffers by itself.
2879 fileio
->req
.count
= count
;
2880 fileio
->req
.memory
= V4L2_MEMORY_MMAP
;
2881 fileio
->req
.type
= q
->type
;
2883 ret
= __reqbufs(q
, &fileio
->req
);
2888 * Check if plane_count is correct
2889 * (multiplane buffers are not supported).
2891 if (q
->bufs
[0]->num_planes
!= 1) {
2897 * Get kernel address of each buffer.
2899 for (i
= 0; i
< q
->num_buffers
; i
++) {
2900 fileio
->bufs
[i
].vaddr
= vb2_plane_vaddr(q
->bufs
[i
], 0);
2901 if (fileio
->bufs
[i
].vaddr
== NULL
) {
2905 fileio
->bufs
[i
].size
= vb2_plane_size(q
->bufs
[i
], 0);
2909 * Read mode requires pre queuing of all buffers.
2912 bool is_multiplanar
= V4L2_TYPE_IS_MULTIPLANAR(q
->type
);
2915 * Queue all buffers.
2917 for (i
= 0; i
< q
->num_buffers
; i
++) {
2918 struct v4l2_buffer
*b
= &fileio
->b
;
2920 memset(b
, 0, sizeof(*b
));
2922 if (is_multiplanar
) {
2923 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
2924 b
->m
.planes
= &fileio
->p
;
2927 b
->memory
= q
->memory
;
2929 ret
= vb2_internal_qbuf(q
, b
);
2932 fileio
->bufs
[i
].queued
= 1;
2935 * All buffers have been queued, so mark that by setting
2936 * initial_index to q->num_buffers
2938 fileio
->initial_index
= q
->num_buffers
;
2939 fileio
->cur_index
= q
->num_buffers
;
2945 ret
= vb2_internal_streamon(q
, q
->type
);
2952 fileio
->req
.count
= 0;
2953 __reqbufs(q
, &fileio
->req
);
2962 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2963 * @q: videobuf2 queue
2965 static int __vb2_cleanup_fileio(struct vb2_queue
*q
)
2967 struct vb2_fileio_data
*fileio
= q
->fileio
;
2970 vb2_internal_streamoff(q
, q
->type
);
2972 fileio
->req
.count
= 0;
2973 vb2_reqbufs(q
, &fileio
->req
);
2975 dprintk(3, "file io emulator closed\n");
2981 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2982 * @q: videobuf2 queue
2983 * @data: pointed to target userspace buffer
2984 * @count: number of bytes to read or write
2985 * @ppos: file handle position tracking pointer
2986 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2987 * @read: access mode selector (1 means read, 0 means write)
2989 static size_t __vb2_perform_fileio(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2990 loff_t
*ppos
, int nonblock
, int read
)
2992 struct vb2_fileio_data
*fileio
;
2993 struct vb2_fileio_buf
*buf
;
2994 bool is_multiplanar
= V4L2_TYPE_IS_MULTIPLANAR(q
->type
);
2996 * When using write() to write data to an output video node the vb2 core
2997 * should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2998 * else is able to provide this information with the write() operation.
3000 bool set_timestamp
= !read
&&
3001 (q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
3002 V4L2_BUF_FLAG_TIMESTAMP_COPY
;
3005 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
3006 read
? "read" : "write", (long)*ppos
, count
,
3007 nonblock
? "non" : "");
3013 * Initialize emulator on first call.
3015 if (!vb2_fileio_is_active(q
)) {
3016 ret
= __vb2_init_fileio(q
, read
);
3017 dprintk(3, "vb2_init_fileio result: %d\n", ret
);
3024 * Check if we need to dequeue the buffer.
3026 index
= fileio
->cur_index
;
3027 if (index
>= q
->num_buffers
) {
3029 * Call vb2_dqbuf to get buffer back.
3031 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3032 fileio
->b
.type
= q
->type
;
3033 fileio
->b
.memory
= q
->memory
;
3034 if (is_multiplanar
) {
3035 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
3036 fileio
->b
.m
.planes
= &fileio
->p
;
3037 fileio
->b
.length
= 1;
3039 ret
= vb2_internal_dqbuf(q
, &fileio
->b
, nonblock
);
3040 dprintk(5, "vb2_dqbuf result: %d\n", ret
);
3043 fileio
->dq_count
+= 1;
3045 fileio
->cur_index
= index
= fileio
->b
.index
;
3046 buf
= &fileio
->bufs
[index
];
3049 * Get number of bytes filled by the driver
3053 buf
->size
= read
? vb2_get_plane_payload(q
->bufs
[index
], 0)
3054 : vb2_plane_size(q
->bufs
[index
], 0);
3055 /* Compensate for data_offset on read in the multiplanar case. */
3056 if (is_multiplanar
&& read
&&
3057 fileio
->b
.m
.planes
[0].data_offset
< buf
->size
) {
3058 buf
->pos
= fileio
->b
.m
.planes
[0].data_offset
;
3059 buf
->size
-= buf
->pos
;
3062 buf
= &fileio
->bufs
[index
];
3066 * Limit count on last few bytes of the buffer.
3068 if (buf
->pos
+ count
> buf
->size
) {
3069 count
= buf
->size
- buf
->pos
;
3070 dprintk(5, "reducing read count: %zd\n", count
);
3074 * Transfer data to userspace.
3076 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
3077 count
, index
, buf
->pos
);
3079 ret
= copy_to_user(data
, buf
->vaddr
+ buf
->pos
, count
);
3081 ret
= copy_from_user(buf
->vaddr
+ buf
->pos
, data
, count
);
3083 dprintk(3, "error copying data\n");
3094 * Queue next buffer if required.
3096 if (buf
->pos
== buf
->size
|| (!read
&& fileio
->write_immediately
)) {
3098 * Check if this is the last buffer to read.
3100 if (read
&& fileio
->read_once
&& fileio
->dq_count
== 1) {
3101 dprintk(3, "read limit reached\n");
3102 return __vb2_cleanup_fileio(q
);
3106 * Call vb2_qbuf and give buffer to the driver.
3108 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3109 fileio
->b
.type
= q
->type
;
3110 fileio
->b
.memory
= q
->memory
;
3111 fileio
->b
.index
= index
;
3112 fileio
->b
.bytesused
= buf
->pos
;
3113 if (is_multiplanar
) {
3114 memset(&fileio
->p
, 0, sizeof(fileio
->p
));
3115 fileio
->p
.bytesused
= buf
->pos
;
3116 fileio
->b
.m
.planes
= &fileio
->p
;
3117 fileio
->b
.length
= 1;
3120 v4l2_get_timestamp(&fileio
->b
.timestamp
);
3121 ret
= vb2_internal_qbuf(q
, &fileio
->b
);
3122 dprintk(5, "vb2_dbuf result: %d\n", ret
);
3127 * Buffer has been queued, update the status
3131 buf
->size
= vb2_plane_size(q
->bufs
[index
], 0);
3132 fileio
->q_count
+= 1;
3134 * If we are queuing up buffers for the first time, then
3135 * increase initial_index by one.
3137 if (fileio
->initial_index
< q
->num_buffers
)
3138 fileio
->initial_index
++;
3140 * The next buffer to use is either a buffer that's going to be
3141 * queued for the first time (initial_index < q->num_buffers)
3142 * or it is equal to q->num_buffers, meaning that the next
3143 * time we need to dequeue a buffer since we've now queued up
3144 * all the 'first time' buffers.
3146 fileio
->cur_index
= fileio
->initial_index
;
3150 * Return proper number of bytes processed.
3157 size_t vb2_read(struct vb2_queue
*q
, char __user
*data
, size_t count
,
3158 loff_t
*ppos
, int nonblocking
)
3160 return __vb2_perform_fileio(q
, data
, count
, ppos
, nonblocking
, 1);
3162 EXPORT_SYMBOL_GPL(vb2_read
);
3164 size_t vb2_write(struct vb2_queue
*q
, const char __user
*data
, size_t count
,
3165 loff_t
*ppos
, int nonblocking
)
3167 return __vb2_perform_fileio(q
, (char __user
*) data
, count
,
3168 ppos
, nonblocking
, 0);
3170 EXPORT_SYMBOL_GPL(vb2_write
);
3172 struct vb2_threadio_data
{
3173 struct task_struct
*thread
;
3179 static int vb2_thread(void *data
)
3181 struct vb2_queue
*q
= data
;
3182 struct vb2_threadio_data
*threadio
= q
->threadio
;
3183 struct vb2_fileio_data
*fileio
= q
->fileio
;
3184 bool set_timestamp
= false;
3189 if (V4L2_TYPE_IS_OUTPUT(q
->type
)) {
3190 prequeue
= q
->num_buffers
;
3192 (q
->timestamp_flags
& V4L2_BUF_FLAG_TIMESTAMP_MASK
) ==
3193 V4L2_BUF_FLAG_TIMESTAMP_COPY
;
3199 struct vb2_buffer
*vb
;
3202 * Call vb2_dqbuf to get buffer back.
3204 memset(&fileio
->b
, 0, sizeof(fileio
->b
));
3205 fileio
->b
.type
= q
->type
;
3206 fileio
->b
.memory
= q
->memory
;
3208 fileio
->b
.index
= index
++;
3211 call_void_qop(q
, wait_finish
, q
);
3212 if (!threadio
->stop
)
3213 ret
= vb2_internal_dqbuf(q
, &fileio
->b
, 0);
3214 call_void_qop(q
, wait_prepare
, q
);
3215 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret
);
3217 if (ret
|| threadio
->stop
)
3221 vb
= q
->bufs
[fileio
->b
.index
];
3222 if (!(fileio
->b
.flags
& V4L2_BUF_FLAG_ERROR
))
3223 if (threadio
->fnc(vb
, threadio
->priv
))
3225 call_void_qop(q
, wait_finish
, q
);
3227 v4l2_get_timestamp(&fileio
->b
.timestamp
);
3228 if (!threadio
->stop
)
3229 ret
= vb2_internal_qbuf(q
, &fileio
->b
);
3230 call_void_qop(q
, wait_prepare
, q
);
3231 if (ret
|| threadio
->stop
)
3235 /* Hmm, linux becomes *very* unhappy without this ... */
3236 while (!kthread_should_stop()) {
3237 set_current_state(TASK_INTERRUPTIBLE
);
3244 * This function should not be used for anything else but the videobuf2-dvb
3245 * support. If you think you have another good use-case for this, then please
3246 * contact the linux-media mailinglist first.
3248 int vb2_thread_start(struct vb2_queue
*q
, vb2_thread_fnc fnc
, void *priv
,
3249 const char *thread_name
)
3251 struct vb2_threadio_data
*threadio
;
3258 if (WARN_ON(q
->fileio
))
3261 threadio
= kzalloc(sizeof(*threadio
), GFP_KERNEL
);
3262 if (threadio
== NULL
)
3264 threadio
->fnc
= fnc
;
3265 threadio
->priv
= priv
;
3267 ret
= __vb2_init_fileio(q
, !V4L2_TYPE_IS_OUTPUT(q
->type
));
3268 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret
);
3271 q
->threadio
= threadio
;
3272 threadio
->thread
= kthread_run(vb2_thread
, q
, "vb2-%s", thread_name
);
3273 if (IS_ERR(threadio
->thread
)) {
3274 ret
= PTR_ERR(threadio
->thread
);
3275 threadio
->thread
= NULL
;
3281 __vb2_cleanup_fileio(q
);
3286 EXPORT_SYMBOL_GPL(vb2_thread_start
);
3288 int vb2_thread_stop(struct vb2_queue
*q
)
3290 struct vb2_threadio_data
*threadio
= q
->threadio
;
3293 if (threadio
== NULL
)
3295 threadio
->stop
= true;
3296 /* Wake up all pending sleeps in the thread */
3298 err
= kthread_stop(threadio
->thread
);
3299 __vb2_cleanup_fileio(q
);
3300 threadio
->thread
= NULL
;
3305 EXPORT_SYMBOL_GPL(vb2_thread_stop
);
3308 * The following functions are not part of the vb2 core API, but are helper
3309 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
3310 * and struct vb2_ops.
3311 * They contain boilerplate code that most if not all drivers have to do
3312 * and so they simplify the driver code.
3315 /* The queue is busy if there is a owner and you are not that owner. */
3316 static inline bool vb2_queue_is_busy(struct video_device
*vdev
, struct file
*file
)
3318 return vdev
->queue
->owner
&& vdev
->queue
->owner
!= file
->private_data
;
3321 /* vb2 ioctl helpers */
3323 int vb2_ioctl_reqbufs(struct file
*file
, void *priv
,
3324 struct v4l2_requestbuffers
*p
)
3326 struct video_device
*vdev
= video_devdata(file
);
3327 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->type
);
3331 if (vb2_queue_is_busy(vdev
, file
))
3333 res
= __reqbufs(vdev
->queue
, p
);
3334 /* If count == 0, then the owner has released all buffers and he
3335 is no longer owner of the queue. Otherwise we have a new owner. */
3337 vdev
->queue
->owner
= p
->count
? file
->private_data
: NULL
;
3340 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs
);
3342 int vb2_ioctl_create_bufs(struct file
*file
, void *priv
,
3343 struct v4l2_create_buffers
*p
)
3345 struct video_device
*vdev
= video_devdata(file
);
3346 int res
= __verify_memory_type(vdev
->queue
, p
->memory
, p
->format
.type
);
3348 p
->index
= vdev
->queue
->num_buffers
;
3349 /* If count == 0, then just check if memory and type are valid.
3350 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
3352 return res
!= -EBUSY
? res
: 0;
3355 if (vb2_queue_is_busy(vdev
, file
))
3357 res
= __create_bufs(vdev
->queue
, p
);
3359 vdev
->queue
->owner
= file
->private_data
;
3362 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs
);
3364 int vb2_ioctl_prepare_buf(struct file
*file
, void *priv
,
3365 struct v4l2_buffer
*p
)
3367 struct video_device
*vdev
= video_devdata(file
);
3369 if (vb2_queue_is_busy(vdev
, file
))
3371 return vb2_prepare_buf(vdev
->queue
, p
);
3373 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf
);
3375 int vb2_ioctl_querybuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3377 struct video_device
*vdev
= video_devdata(file
);
3379 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
3380 return vb2_querybuf(vdev
->queue
, p
);
3382 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf
);
3384 int vb2_ioctl_qbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3386 struct video_device
*vdev
= video_devdata(file
);
3388 if (vb2_queue_is_busy(vdev
, file
))
3390 return vb2_qbuf(vdev
->queue
, p
);
3392 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf
);
3394 int vb2_ioctl_dqbuf(struct file
*file
, void *priv
, struct v4l2_buffer
*p
)
3396 struct video_device
*vdev
= video_devdata(file
);
3398 if (vb2_queue_is_busy(vdev
, file
))
3400 return vb2_dqbuf(vdev
->queue
, p
, file
->f_flags
& O_NONBLOCK
);
3402 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf
);
3404 int vb2_ioctl_streamon(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
3406 struct video_device
*vdev
= video_devdata(file
);
3408 if (vb2_queue_is_busy(vdev
, file
))
3410 return vb2_streamon(vdev
->queue
, i
);
3412 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon
);
3414 int vb2_ioctl_streamoff(struct file
*file
, void *priv
, enum v4l2_buf_type i
)
3416 struct video_device
*vdev
= video_devdata(file
);
3418 if (vb2_queue_is_busy(vdev
, file
))
3420 return vb2_streamoff(vdev
->queue
, i
);
3422 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff
);
3424 int vb2_ioctl_expbuf(struct file
*file
, void *priv
, struct v4l2_exportbuffer
*p
)
3426 struct video_device
*vdev
= video_devdata(file
);
3428 if (vb2_queue_is_busy(vdev
, file
))
3430 return vb2_expbuf(vdev
->queue
, p
);
3432 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf
);
3434 /* v4l2_file_operations helpers */
3436 int vb2_fop_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3438 struct video_device
*vdev
= video_devdata(file
);
3440 return vb2_mmap(vdev
->queue
, vma
);
3442 EXPORT_SYMBOL_GPL(vb2_fop_mmap
);
3444 int _vb2_fop_release(struct file
*file
, struct mutex
*lock
)
3446 struct video_device
*vdev
= video_devdata(file
);
3450 if (file
->private_data
== vdev
->queue
->owner
) {
3451 vb2_queue_release(vdev
->queue
);
3452 vdev
->queue
->owner
= NULL
;
3456 return v4l2_fh_release(file
);
3458 EXPORT_SYMBOL_GPL(_vb2_fop_release
);
3460 int vb2_fop_release(struct file
*file
)
3462 struct video_device
*vdev
= video_devdata(file
);
3463 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3465 return _vb2_fop_release(file
, lock
);
3467 EXPORT_SYMBOL_GPL(vb2_fop_release
);
3469 ssize_t
vb2_fop_write(struct file
*file
, const char __user
*buf
,
3470 size_t count
, loff_t
*ppos
)
3472 struct video_device
*vdev
= video_devdata(file
);
3473 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3476 if (!(vdev
->queue
->io_modes
& VB2_WRITE
))
3478 if (lock
&& mutex_lock_interruptible(lock
))
3479 return -ERESTARTSYS
;
3480 if (vb2_queue_is_busy(vdev
, file
))
3482 err
= vb2_write(vdev
->queue
, buf
, count
, ppos
,
3483 file
->f_flags
& O_NONBLOCK
);
3484 if (vdev
->queue
->fileio
)
3485 vdev
->queue
->owner
= file
->private_data
;
3491 EXPORT_SYMBOL_GPL(vb2_fop_write
);
3493 ssize_t
vb2_fop_read(struct file
*file
, char __user
*buf
,
3494 size_t count
, loff_t
*ppos
)
3496 struct video_device
*vdev
= video_devdata(file
);
3497 struct mutex
*lock
= vdev
->queue
->lock
? vdev
->queue
->lock
: vdev
->lock
;
3500 if (!(vdev
->queue
->io_modes
& VB2_READ
))
3502 if (lock
&& mutex_lock_interruptible(lock
))
3503 return -ERESTARTSYS
;
3504 if (vb2_queue_is_busy(vdev
, file
))
3506 err
= vb2_read(vdev
->queue
, buf
, count
, ppos
,
3507 file
->f_flags
& O_NONBLOCK
);
3508 if (vdev
->queue
->fileio
)
3509 vdev
->queue
->owner
= file
->private_data
;
3515 EXPORT_SYMBOL_GPL(vb2_fop_read
);
3517 unsigned int vb2_fop_poll(struct file
*file
, poll_table
*wait
)
3519 struct video_device
*vdev
= video_devdata(file
);
3520 struct vb2_queue
*q
= vdev
->queue
;
3521 struct mutex
*lock
= q
->lock
? q
->lock
: vdev
->lock
;
3526 * If this helper doesn't know how to lock, then you shouldn't be using
3527 * it but you should write your own.
3531 if (lock
&& mutex_lock_interruptible(lock
))
3536 res
= vb2_poll(vdev
->queue
, file
, wait
);
3538 /* If fileio was started, then we have a new queue owner. */
3539 if (!fileio
&& q
->fileio
)
3540 q
->owner
= file
->private_data
;
3545 EXPORT_SYMBOL_GPL(vb2_fop_poll
);
3548 unsigned long vb2_fop_get_unmapped_area(struct file
*file
, unsigned long addr
,
3549 unsigned long len
, unsigned long pgoff
, unsigned long flags
)
3551 struct video_device
*vdev
= video_devdata(file
);
3553 return vb2_get_unmapped_area(vdev
->queue
, addr
, len
, pgoff
, flags
);
3555 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area
);
3558 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
3560 void vb2_ops_wait_prepare(struct vb2_queue
*vq
)
3562 mutex_unlock(vq
->lock
);
3564 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare
);
3566 void vb2_ops_wait_finish(struct vb2_queue
*vq
)
3568 mutex_lock(vq
->lock
);
3570 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish
);
3572 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
3573 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
3574 MODULE_LICENSE("GPL");