2 * videobuf2-core.c - video buffer 2 core framework
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
7 * Marek Szyprowski <m.szyprowski@samsung.com>
9 * The vb2_thread implementation was based on code from videobuf-dvb.c:
10 * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation.
17 #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/videobuf2-core.h>
29 #include <trace/events/vb2.h>
32 module_param(debug
, int, 0644);
34 #define dprintk(level, fmt, arg...) \
37 pr_info("vb2-core: %s: " fmt, __func__, ## arg); \
40 #ifdef CONFIG_VIDEO_ADV_DEBUG
43 * If advanced debugging is on, then count how often each op is called
44 * successfully, which can either be per-buffer or per-queue.
46 * This makes it easy to check that the 'init' and 'cleanup'
47 * (and variations thereof) stay balanced.
50 #define log_memop(vb, op) \
51 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
52 (vb)->vb2_queue, (vb)->index, #op, \
53 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
55 #define call_memop(vb, op, args...) \
57 struct vb2_queue *_q = (vb)->vb2_queue; \
61 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
63 (vb)->cnt_mem_ ## op++; \
67 #define call_ptr_memop(vb, op, args...) \
69 struct vb2_queue *_q = (vb)->vb2_queue; \
73 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
74 if (!IS_ERR_OR_NULL(ptr)) \
75 (vb)->cnt_mem_ ## op++; \
79 #define call_void_memop(vb, op, args...) \
81 struct vb2_queue *_q = (vb)->vb2_queue; \
84 if (_q->mem_ops->op) \
85 _q->mem_ops->op(args); \
86 (vb)->cnt_mem_ ## op++; \
89 #define log_qop(q, op) \
90 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
91 (q)->ops->op ? "" : " (nop)")
93 #define call_qop(q, op, args...) \
98 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
104 #define call_void_qop(q, op, args...) \
108 (q)->ops->op(args); \
112 #define log_vb_qop(vb, op, args...) \
113 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
114 (vb)->vb2_queue, (vb)->index, #op, \
115 (vb)->vb2_queue->ops->op ? "" : " (nop)")
117 #define call_vb_qop(vb, op, args...) \
121 log_vb_qop(vb, op); \
122 err = (vb)->vb2_queue->ops->op ? \
123 (vb)->vb2_queue->ops->op(args) : 0; \
125 (vb)->cnt_ ## op++; \
129 #define call_void_vb_qop(vb, op, args...) \
131 log_vb_qop(vb, op); \
132 if ((vb)->vb2_queue->ops->op) \
133 (vb)->vb2_queue->ops->op(args); \
134 (vb)->cnt_ ## op++; \
139 #define call_memop(vb, op, args...) \
140 ((vb)->vb2_queue->mem_ops->op ? \
141 (vb)->vb2_queue->mem_ops->op(args) : 0)
143 #define call_ptr_memop(vb, op, args...) \
144 ((vb)->vb2_queue->mem_ops->op ? \
145 (vb)->vb2_queue->mem_ops->op(args) : NULL)
147 #define call_void_memop(vb, op, args...) \
149 if ((vb)->vb2_queue->mem_ops->op) \
150 (vb)->vb2_queue->mem_ops->op(args); \
153 #define call_qop(q, op, args...) \
154 ((q)->ops->op ? (q)->ops->op(args) : 0)
156 #define call_void_qop(q, op, args...) \
159 (q)->ops->op(args); \
162 #define call_vb_qop(vb, op, args...) \
163 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
165 #define call_void_vb_qop(vb, op, args...) \
167 if ((vb)->vb2_queue->ops->op) \
168 (vb)->vb2_queue->ops->op(args); \
173 #define call_bufop(q, op, args...) \
176 if (q && q->buf_ops && q->buf_ops->op) \
177 ret = q->buf_ops->op(args); \
181 #define call_void_bufop(q, op, args...) \
183 if (q && q->buf_ops && q->buf_ops->op) \
184 q->buf_ops->op(args); \
187 static void __vb2_queue_cancel(struct vb2_queue
*q
);
188 static void __enqueue_in_driver(struct vb2_buffer
*vb
);
191 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
193 static int __vb2_buf_mem_alloc(struct vb2_buffer
*vb
)
195 struct vb2_queue
*q
= vb
->vb2_queue
;
196 enum dma_data_direction dma_dir
=
197 q
->is_output
? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
202 * Allocate memory for all planes in this buffer
203 * NOTE: mmapped areas should be page aligned
205 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
206 unsigned long size
= PAGE_ALIGN(vb
->planes
[plane
].length
);
208 mem_priv
= call_ptr_memop(vb
, alloc
, q
->alloc_ctx
[plane
],
209 size
, dma_dir
, q
->gfp_flags
);
210 if (IS_ERR_OR_NULL(mem_priv
))
213 /* Associate allocator private data with this plane */
214 vb
->planes
[plane
].mem_priv
= mem_priv
;
219 /* Free already allocated memory if one of the allocations failed */
220 for (; plane
> 0; --plane
) {
221 call_void_memop(vb
, put
, vb
->planes
[plane
- 1].mem_priv
);
222 vb
->planes
[plane
- 1].mem_priv
= NULL
;
229 * __vb2_buf_mem_free() - free memory of the given buffer
231 static void __vb2_buf_mem_free(struct vb2_buffer
*vb
)
235 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
236 call_void_memop(vb
, put
, vb
->planes
[plane
].mem_priv
);
237 vb
->planes
[plane
].mem_priv
= NULL
;
238 dprintk(3, "freed plane %d of buffer %d\n", plane
, vb
->index
);
243 * __vb2_buf_userptr_put() - release userspace memory associated with
246 static void __vb2_buf_userptr_put(struct vb2_buffer
*vb
)
250 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
251 if (vb
->planes
[plane
].mem_priv
)
252 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
253 vb
->planes
[plane
].mem_priv
= NULL
;
258 * __vb2_plane_dmabuf_put() - release memory associated with
259 * a DMABUF shared plane
261 static void __vb2_plane_dmabuf_put(struct vb2_buffer
*vb
, struct vb2_plane
*p
)
267 call_void_memop(vb
, unmap_dmabuf
, p
->mem_priv
);
269 call_void_memop(vb
, detach_dmabuf
, p
->mem_priv
);
270 dma_buf_put(p
->dbuf
);
277 * __vb2_buf_dmabuf_put() - release memory associated with
278 * a DMABUF shared buffer
280 static void __vb2_buf_dmabuf_put(struct vb2_buffer
*vb
)
284 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
285 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
289 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
292 static void __setup_offsets(struct vb2_buffer
*vb
)
294 struct vb2_queue
*q
= vb
->vb2_queue
;
296 unsigned long off
= 0;
299 struct vb2_buffer
*prev
= q
->bufs
[vb
->index
- 1];
300 struct vb2_plane
*p
= &prev
->planes
[prev
->num_planes
- 1];
302 off
= PAGE_ALIGN(p
->m
.offset
+ p
->length
);
305 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
306 vb
->planes
[plane
].m
.offset
= off
;
308 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
309 vb
->index
, plane
, off
);
311 off
+= vb
->planes
[plane
].length
;
312 off
= PAGE_ALIGN(off
);
317 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
318 * video buffer memory for all buffers/planes on the queue and initializes the
321 * Returns the number of buffers successfully allocated.
323 static int __vb2_queue_alloc(struct vb2_queue
*q
, enum vb2_memory memory
,
324 unsigned int num_buffers
, unsigned int num_planes
,
325 const unsigned plane_sizes
[VB2_MAX_PLANES
])
327 unsigned int buffer
, plane
;
328 struct vb2_buffer
*vb
;
331 for (buffer
= 0; buffer
< num_buffers
; ++buffer
) {
332 /* Allocate videobuf buffer structures */
333 vb
= kzalloc(q
->buf_struct_size
, GFP_KERNEL
);
335 dprintk(1, "memory alloc for buffer struct failed\n");
339 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
341 vb
->num_planes
= num_planes
;
342 vb
->index
= q
->num_buffers
+ buffer
;
345 for (plane
= 0; plane
< num_planes
; ++plane
) {
346 vb
->planes
[plane
].length
= plane_sizes
[plane
];
347 vb
->planes
[plane
].min_length
= plane_sizes
[plane
];
349 q
->bufs
[vb
->index
] = vb
;
351 /* Allocate video buffer memory for the MMAP type */
352 if (memory
== VB2_MEMORY_MMAP
) {
353 ret
= __vb2_buf_mem_alloc(vb
);
355 dprintk(1, "failed allocating memory for "
356 "buffer %d\n", buffer
);
357 q
->bufs
[vb
->index
] = NULL
;
363 * Call the driver-provided buffer initialization
364 * callback, if given. An error in initialization
365 * results in queue setup failure.
367 ret
= call_vb_qop(vb
, buf_init
, vb
);
369 dprintk(1, "buffer %d %p initialization"
370 " failed\n", buffer
, vb
);
371 __vb2_buf_mem_free(vb
);
372 q
->bufs
[vb
->index
] = NULL
;
379 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
386 * __vb2_free_mem() - release all video buffer memory for a given queue
388 static void __vb2_free_mem(struct vb2_queue
*q
, unsigned int buffers
)
391 struct vb2_buffer
*vb
;
393 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
395 vb
= q
->bufs
[buffer
];
399 /* Free MMAP buffers or release USERPTR buffers */
400 if (q
->memory
== VB2_MEMORY_MMAP
)
401 __vb2_buf_mem_free(vb
);
402 else if (q
->memory
== VB2_MEMORY_DMABUF
)
403 __vb2_buf_dmabuf_put(vb
);
405 __vb2_buf_userptr_put(vb
);
410 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
411 * related information, if no buffers are left return the queue to an
412 * uninitialized state. Might be called even if the queue has already been freed.
414 static int __vb2_queue_free(struct vb2_queue
*q
, unsigned int buffers
)
419 * Sanity check: when preparing a buffer the queue lock is released for
420 * a short while (see __buf_prepare for the details), which would allow
421 * a race with a reqbufs which can call this function. Removing the
422 * buffers from underneath __buf_prepare is obviously a bad idea, so we
423 * check if any of the buffers is in the state PREPARING, and if so we
424 * just return -EAGAIN.
426 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
428 if (q
->bufs
[buffer
] == NULL
)
430 if (q
->bufs
[buffer
]->state
== VB2_BUF_STATE_PREPARING
) {
431 dprintk(1, "preparing buffers, cannot free\n");
436 /* Call driver-provided cleanup function for each buffer, if provided */
437 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
439 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
441 if (vb
&& vb
->planes
[0].mem_priv
)
442 call_void_vb_qop(vb
, buf_cleanup
, vb
);
445 /* Release video buffer memory */
446 __vb2_free_mem(q
, buffers
);
448 #ifdef CONFIG_VIDEO_ADV_DEBUG
450 * Check that all the calls were balances during the life-time of this
451 * queue. If not (or if the debug level is 1 or up), then dump the
452 * counters to the kernel log.
454 if (q
->num_buffers
) {
455 bool unbalanced
= q
->cnt_start_streaming
!= q
->cnt_stop_streaming
||
456 q
->cnt_wait_prepare
!= q
->cnt_wait_finish
;
458 if (unbalanced
|| debug
) {
459 pr_info("vb2: counters for queue %p:%s\n", q
,
460 unbalanced
? " UNBALANCED!" : "");
461 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
462 q
->cnt_queue_setup
, q
->cnt_start_streaming
,
463 q
->cnt_stop_streaming
);
464 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
465 q
->cnt_wait_prepare
, q
->cnt_wait_finish
);
467 q
->cnt_queue_setup
= 0;
468 q
->cnt_wait_prepare
= 0;
469 q
->cnt_wait_finish
= 0;
470 q
->cnt_start_streaming
= 0;
471 q
->cnt_stop_streaming
= 0;
473 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
474 struct vb2_buffer
*vb
= q
->bufs
[buffer
];
475 bool unbalanced
= vb
->cnt_mem_alloc
!= vb
->cnt_mem_put
||
476 vb
->cnt_mem_prepare
!= vb
->cnt_mem_finish
||
477 vb
->cnt_mem_get_userptr
!= vb
->cnt_mem_put_userptr
||
478 vb
->cnt_mem_attach_dmabuf
!= vb
->cnt_mem_detach_dmabuf
||
479 vb
->cnt_mem_map_dmabuf
!= vb
->cnt_mem_unmap_dmabuf
||
480 vb
->cnt_buf_queue
!= vb
->cnt_buf_done
||
481 vb
->cnt_buf_prepare
!= vb
->cnt_buf_finish
||
482 vb
->cnt_buf_init
!= vb
->cnt_buf_cleanup
;
484 if (unbalanced
|| debug
) {
485 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
486 q
, buffer
, unbalanced
? " UNBALANCED!" : "");
487 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
488 vb
->cnt_buf_init
, vb
->cnt_buf_cleanup
,
489 vb
->cnt_buf_prepare
, vb
->cnt_buf_finish
);
490 pr_info("vb2: buf_queue: %u buf_done: %u\n",
491 vb
->cnt_buf_queue
, vb
->cnt_buf_done
);
492 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
493 vb
->cnt_mem_alloc
, vb
->cnt_mem_put
,
494 vb
->cnt_mem_prepare
, vb
->cnt_mem_finish
,
496 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
497 vb
->cnt_mem_get_userptr
, vb
->cnt_mem_put_userptr
);
498 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
499 vb
->cnt_mem_attach_dmabuf
, vb
->cnt_mem_detach_dmabuf
,
500 vb
->cnt_mem_map_dmabuf
, vb
->cnt_mem_unmap_dmabuf
);
501 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
502 vb
->cnt_mem_get_dmabuf
,
503 vb
->cnt_mem_num_users
,
510 /* Free videobuf buffers */
511 for (buffer
= q
->num_buffers
- buffers
; buffer
< q
->num_buffers
;
513 kfree(q
->bufs
[buffer
]);
514 q
->bufs
[buffer
] = NULL
;
517 q
->num_buffers
-= buffers
;
518 if (!q
->num_buffers
) {
520 INIT_LIST_HEAD(&q
->queued_list
);
526 * vb2_buffer_in_use() - return true if the buffer is in use and
527 * the queue cannot be freed (by the means of REQBUFS(0)) call
529 bool vb2_buffer_in_use(struct vb2_queue
*q
, struct vb2_buffer
*vb
)
532 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
533 void *mem_priv
= vb
->planes
[plane
].mem_priv
;
535 * If num_users() has not been provided, call_memop
536 * will return 0, apparently nobody cares about this
537 * case anyway. If num_users() returns more than 1,
538 * we are not the only user of the plane's memory.
540 if (mem_priv
&& call_memop(vb
, num_users
, mem_priv
) > 1)
545 EXPORT_SYMBOL(vb2_buffer_in_use
);
548 * __buffers_in_use() - return true if any buffers on the queue are in use and
549 * the queue cannot be freed (by the means of REQBUFS(0)) call
551 static bool __buffers_in_use(struct vb2_queue
*q
)
554 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
555 if (vb2_buffer_in_use(q
, q
->bufs
[buffer
]))
562 * vb2_core_querybuf() - query video buffer information
564 * @index: id number of the buffer
565 * @pb: buffer struct passed from userspace
567 * Should be called from vidioc_querybuf ioctl handler in driver.
568 * The passed buffer should have been verified.
569 * This function fills the relevant information for the userspace.
571 void vb2_core_querybuf(struct vb2_queue
*q
, unsigned int index
, void *pb
)
573 call_void_bufop(q
, fill_user_buffer
, q
->bufs
[index
], pb
);
575 EXPORT_SYMBOL_GPL(vb2_core_querybuf
);
578 * __verify_userptr_ops() - verify that all memory operations required for
579 * USERPTR queue type have been provided
581 static int __verify_userptr_ops(struct vb2_queue
*q
)
583 if (!(q
->io_modes
& VB2_USERPTR
) || !q
->mem_ops
->get_userptr
||
584 !q
->mem_ops
->put_userptr
)
591 * __verify_mmap_ops() - verify that all memory operations required for
592 * MMAP queue type have been provided
594 static int __verify_mmap_ops(struct vb2_queue
*q
)
596 if (!(q
->io_modes
& VB2_MMAP
) || !q
->mem_ops
->alloc
||
597 !q
->mem_ops
->put
|| !q
->mem_ops
->mmap
)
604 * __verify_dmabuf_ops() - verify that all memory operations required for
605 * DMABUF queue type have been provided
607 static int __verify_dmabuf_ops(struct vb2_queue
*q
)
609 if (!(q
->io_modes
& VB2_DMABUF
) || !q
->mem_ops
->attach_dmabuf
||
610 !q
->mem_ops
->detach_dmabuf
|| !q
->mem_ops
->map_dmabuf
||
611 !q
->mem_ops
->unmap_dmabuf
)
618 * vb2_verify_memory_type() - Check whether the memory type and buffer type
619 * passed to a buffer operation are compatible with the queue.
621 int vb2_verify_memory_type(struct vb2_queue
*q
,
622 enum vb2_memory memory
, unsigned int type
)
624 if (memory
!= VB2_MEMORY_MMAP
&& memory
!= VB2_MEMORY_USERPTR
&&
625 memory
!= VB2_MEMORY_DMABUF
) {
626 dprintk(1, "unsupported memory type\n");
630 if (type
!= q
->type
) {
631 dprintk(1, "requested type is incorrect\n");
636 * Make sure all the required memory ops for given memory type
639 if (memory
== VB2_MEMORY_MMAP
&& __verify_mmap_ops(q
)) {
640 dprintk(1, "MMAP for current setup unsupported\n");
644 if (memory
== VB2_MEMORY_USERPTR
&& __verify_userptr_ops(q
)) {
645 dprintk(1, "USERPTR for current setup unsupported\n");
649 if (memory
== VB2_MEMORY_DMABUF
&& __verify_dmabuf_ops(q
)) {
650 dprintk(1, "DMABUF for current setup unsupported\n");
655 * Place the busy tests at the end: -EBUSY can be ignored when
656 * create_bufs is called with count == 0, but count == 0 should still
657 * do the memory and type validation.
659 if (vb2_fileio_is_active(q
)) {
660 dprintk(1, "file io in progress\n");
665 EXPORT_SYMBOL(vb2_verify_memory_type
);
668 * vb2_core_reqbufs() - Initiate streaming
669 * @q: videobuf2 queue
670 * @memory: memory type
671 * @count: requested buffer count
673 * Should be called from vidioc_reqbufs ioctl handler of a driver.
675 * 1) verifies streaming parameters passed from the userspace,
676 * 2) sets up the queue,
677 * 3) negotiates number of buffers and planes per buffer with the driver
678 * to be used during streaming,
679 * 4) allocates internal buffer structures (struct vb2_buffer), according to
680 * the agreed parameters,
681 * 5) for MMAP memory type, allocates actual video memory, using the
682 * memory handling/allocation routines provided during queue initialization
684 * If req->count is 0, all the memory will be freed instead.
685 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
686 * and the queue is not busy, memory will be reallocated.
688 * The return values from this function are intended to be directly returned
689 * from vidioc_reqbufs handler in driver.
691 int vb2_core_reqbufs(struct vb2_queue
*q
, enum vb2_memory memory
,
694 unsigned int num_buffers
, allocated_buffers
, num_planes
= 0;
695 unsigned plane_sizes
[VB2_MAX_PLANES
] = { };
699 dprintk(1, "streaming active\n");
703 if (*count
== 0 || q
->num_buffers
!= 0 || q
->memory
!= memory
) {
705 * We already have buffers allocated, so first check if they
706 * are not in use and can be freed.
708 mutex_lock(&q
->mmap_lock
);
709 if (q
->memory
== VB2_MEMORY_MMAP
&& __buffers_in_use(q
)) {
710 mutex_unlock(&q
->mmap_lock
);
711 dprintk(1, "memory in use, cannot free\n");
716 * Call queue_cancel to clean up any buffers in the PREPARED or
717 * QUEUED state which is possible if buffers were prepared or
718 * queued without ever calling STREAMON.
720 __vb2_queue_cancel(q
);
721 ret
= __vb2_queue_free(q
, q
->num_buffers
);
722 mutex_unlock(&q
->mmap_lock
);
727 * In case of REQBUFS(0) return immediately without calling
728 * driver's queue_setup() callback and allocating resources.
735 * Make sure the requested values and current defaults are sane.
737 num_buffers
= min_t(unsigned int, *count
, VB2_MAX_FRAME
);
738 num_buffers
= max_t(unsigned int, num_buffers
, q
->min_buffers_needed
);
739 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
743 * Ask the driver how many buffers and planes per buffer it requires.
744 * Driver also sets the size and allocator context for each plane.
746 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
, &num_planes
,
747 plane_sizes
, q
->alloc_ctx
);
751 /* Finally, allocate buffers and video memory */
753 __vb2_queue_alloc(q
, memory
, num_buffers
, num_planes
, plane_sizes
);
754 if (allocated_buffers
== 0) {
755 dprintk(1, "memory allocation failed\n");
760 * There is no point in continuing if we can't allocate the minimum
761 * number of buffers needed by this vb2_queue.
763 if (allocated_buffers
< q
->min_buffers_needed
)
767 * Check if driver can handle the allocated number of buffers.
769 if (!ret
&& allocated_buffers
< num_buffers
) {
770 num_buffers
= allocated_buffers
;
772 * num_planes is set by the previous queue_setup(), but since it
773 * signals to queue_setup() whether it is called from create_bufs()
774 * vs reqbufs() we zero it here to signal that queue_setup() is
775 * called for the reqbufs() case.
779 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
,
780 &num_planes
, plane_sizes
, q
->alloc_ctx
);
782 if (!ret
&& allocated_buffers
< num_buffers
)
786 * Either the driver has accepted a smaller number of buffers,
787 * or .queue_setup() returned an error
791 mutex_lock(&q
->mmap_lock
);
792 q
->num_buffers
= allocated_buffers
;
796 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
797 * from q->num_buffers.
799 __vb2_queue_free(q
, allocated_buffers
);
800 mutex_unlock(&q
->mmap_lock
);
803 mutex_unlock(&q
->mmap_lock
);
806 * Return the number of successfully allocated buffers
809 *count
= allocated_buffers
;
810 q
->waiting_for_buffers
= !q
->is_output
;
814 EXPORT_SYMBOL_GPL(vb2_core_reqbufs
);
817 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
818 * @q: videobuf2 queue
819 * @memory: memory type
820 * @count: requested buffer count
821 * @parg: parameter passed to device driver
823 * Should be called from vidioc_create_bufs ioctl handler of a driver.
825 * 1) verifies parameter sanity
826 * 2) calls the .queue_setup() queue operation
827 * 3) performs any necessary memory allocations
829 * The return values from this function are intended to be directly returned
830 * from vidioc_create_bufs handler in driver.
832 int vb2_core_create_bufs(struct vb2_queue
*q
, enum vb2_memory memory
,
833 unsigned int *count
, unsigned requested_planes
,
834 const unsigned requested_sizes
[])
836 unsigned int num_planes
= 0, num_buffers
, allocated_buffers
;
837 unsigned plane_sizes
[VB2_MAX_PLANES
] = { };
840 if (q
->num_buffers
== VB2_MAX_FRAME
) {
841 dprintk(1, "maximum number of buffers already allocated\n");
845 if (!q
->num_buffers
) {
846 memset(q
->alloc_ctx
, 0, sizeof(q
->alloc_ctx
));
848 q
->waiting_for_buffers
= !q
->is_output
;
851 num_buffers
= min(*count
, VB2_MAX_FRAME
- q
->num_buffers
);
853 if (requested_planes
&& requested_sizes
) {
854 num_planes
= requested_planes
;
855 memcpy(plane_sizes
, requested_sizes
, sizeof(plane_sizes
));
859 * Ask the driver, whether the requested number of buffers, planes per
860 * buffer and their sizes are acceptable
862 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
,
863 &num_planes
, plane_sizes
, q
->alloc_ctx
);
867 /* Finally, allocate buffers and video memory */
868 allocated_buffers
= __vb2_queue_alloc(q
, memory
, num_buffers
,
869 num_planes
, plane_sizes
);
870 if (allocated_buffers
== 0) {
871 dprintk(1, "memory allocation failed\n");
876 * Check if driver can handle the so far allocated number of buffers.
878 if (allocated_buffers
< num_buffers
) {
879 num_buffers
= allocated_buffers
;
882 * q->num_buffers contains the total number of buffers, that the
883 * queue driver has set up
885 ret
= call_qop(q
, queue_setup
, q
, &num_buffers
,
886 &num_planes
, plane_sizes
, q
->alloc_ctx
);
888 if (!ret
&& allocated_buffers
< num_buffers
)
892 * Either the driver has accepted a smaller number of buffers,
893 * or .queue_setup() returned an error
897 mutex_lock(&q
->mmap_lock
);
898 q
->num_buffers
+= allocated_buffers
;
902 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
903 * from q->num_buffers.
905 __vb2_queue_free(q
, allocated_buffers
);
906 mutex_unlock(&q
->mmap_lock
);
909 mutex_unlock(&q
->mmap_lock
);
912 * Return the number of successfully allocated buffers
915 *count
= allocated_buffers
;
919 EXPORT_SYMBOL_GPL(vb2_core_create_bufs
);
922 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
923 * @vb: vb2_buffer to which the plane in question belongs to
924 * @plane_no: plane number for which the address is to be returned
926 * This function returns a kernel virtual address of a given plane if
927 * such a mapping exist, NULL otherwise.
929 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
)
931 if (plane_no
> vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
934 return call_ptr_memop(vb
, vaddr
, vb
->planes
[plane_no
].mem_priv
);
937 EXPORT_SYMBOL_GPL(vb2_plane_vaddr
);
940 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
941 * @vb: vb2_buffer to which the plane in question belongs to
942 * @plane_no: plane number for which the cookie is to be returned
944 * This function returns an allocator specific cookie for a given plane if
945 * available, NULL otherwise. The allocator should provide some simple static
946 * inline function, which would convert this cookie to the allocator specific
947 * type that can be used directly by the driver to access the buffer. This can
948 * be for example physical address, pointer to scatter list or IOMMU mapping.
950 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
)
952 if (plane_no
>= vb
->num_planes
|| !vb
->planes
[plane_no
].mem_priv
)
955 return call_ptr_memop(vb
, cookie
, vb
->planes
[plane_no
].mem_priv
);
957 EXPORT_SYMBOL_GPL(vb2_plane_cookie
);
960 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
961 * @vb: vb2_buffer returned from the driver
962 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully,
963 * VB2_BUF_STATE_ERROR if the operation finished with an error or
964 * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers.
965 * If start_streaming fails then it should return buffers with state
966 * VB2_BUF_STATE_QUEUED to put them back into the queue.
968 * This function should be called by the driver after a hardware operation on
969 * a buffer is finished and the buffer may be returned to userspace. The driver
970 * cannot use this buffer anymore until it is queued back to it by videobuf
971 * by the means of buf_queue callback. Only buffers previously queued to the
972 * driver by buf_queue can be passed to this function.
974 * While streaming a buffer can only be returned in state DONE or ERROR.
975 * The start_streaming op can also return them in case the DMA engine cannot
976 * be started for some reason. In that case the buffers should be returned with
979 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
)
981 struct vb2_queue
*q
= vb
->vb2_queue
;
985 if (WARN_ON(vb
->state
!= VB2_BUF_STATE_ACTIVE
))
988 if (WARN_ON(state
!= VB2_BUF_STATE_DONE
&&
989 state
!= VB2_BUF_STATE_ERROR
&&
990 state
!= VB2_BUF_STATE_QUEUED
&&
991 state
!= VB2_BUF_STATE_REQUEUEING
))
992 state
= VB2_BUF_STATE_ERROR
;
994 #ifdef CONFIG_VIDEO_ADV_DEBUG
996 * Although this is not a callback, it still does have to balance
997 * with the buf_queue op. So update this counter manually.
1001 dprintk(4, "done processing on buffer %d, state: %d\n",
1005 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1006 call_void_memop(vb
, finish
, vb
->planes
[plane
].mem_priv
);
1008 spin_lock_irqsave(&q
->done_lock
, flags
);
1009 if (state
== VB2_BUF_STATE_QUEUED
||
1010 state
== VB2_BUF_STATE_REQUEUEING
) {
1011 vb
->state
= VB2_BUF_STATE_QUEUED
;
1013 /* Add the buffer to the done buffers list */
1014 list_add_tail(&vb
->done_entry
, &q
->done_list
);
1017 atomic_dec(&q
->owned_by_drv_count
);
1018 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1020 trace_vb2_buf_done(q
, vb
);
1023 case VB2_BUF_STATE_QUEUED
:
1025 case VB2_BUF_STATE_REQUEUEING
:
1026 if (q
->start_streaming_called
)
1027 __enqueue_in_driver(vb
);
1030 /* Inform any processes that may be waiting for buffers */
1031 wake_up(&q
->done_wq
);
1035 EXPORT_SYMBOL_GPL(vb2_buffer_done
);
1038 * vb2_discard_done() - discard all buffers marked as DONE
1039 * @q: videobuf2 queue
1041 * This function is intended to be used with suspend/resume operations. It
1042 * discards all 'done' buffers as they would be too old to be requested after
1045 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
1046 * delayed works before calling this function to make sure no buffer will be
1047 * touched by the driver and/or hardware.
1049 void vb2_discard_done(struct vb2_queue
*q
)
1051 struct vb2_buffer
*vb
;
1052 unsigned long flags
;
1054 spin_lock_irqsave(&q
->done_lock
, flags
);
1055 list_for_each_entry(vb
, &q
->done_list
, done_entry
)
1056 vb
->state
= VB2_BUF_STATE_ERROR
;
1057 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1059 EXPORT_SYMBOL_GPL(vb2_discard_done
);
1062 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1064 static int __qbuf_mmap(struct vb2_buffer
*vb
, const void *pb
)
1066 int ret
= call_bufop(vb
->vb2_queue
, fill_vb2_buffer
,
1067 vb
, pb
, vb
->planes
);
1068 return ret
? ret
: call_vb_qop(vb
, buf_prepare
, vb
);
1072 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1074 static int __qbuf_userptr(struct vb2_buffer
*vb
, const void *pb
)
1076 struct vb2_plane planes
[VB2_MAX_PLANES
];
1077 struct vb2_queue
*q
= vb
->vb2_queue
;
1081 enum dma_data_direction dma_dir
=
1082 q
->is_output
? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1083 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1085 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1086 /* Copy relevant information provided by the userspace */
1087 ret
= call_bufop(vb
->vb2_queue
, fill_vb2_buffer
, vb
, pb
, planes
);
1091 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1092 /* Skip the plane if already verified */
1093 if (vb
->planes
[plane
].m
.userptr
&&
1094 vb
->planes
[plane
].m
.userptr
== planes
[plane
].m
.userptr
1095 && vb
->planes
[plane
].length
== planes
[plane
].length
)
1098 dprintk(3, "userspace address for plane %d changed, "
1099 "reacquiring memory\n", plane
);
1101 /* Check if the provided plane buffer is large enough */
1102 if (planes
[plane
].length
< vb
->planes
[plane
].min_length
) {
1103 dprintk(1, "provided buffer size %u is less than "
1104 "setup size %u for plane %d\n",
1105 planes
[plane
].length
,
1106 vb
->planes
[plane
].min_length
,
1112 /* Release previously acquired memory if present */
1113 if (vb
->planes
[plane
].mem_priv
) {
1116 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1118 call_void_memop(vb
, put_userptr
, vb
->planes
[plane
].mem_priv
);
1121 vb
->planes
[plane
].mem_priv
= NULL
;
1122 vb
->planes
[plane
].bytesused
= 0;
1123 vb
->planes
[plane
].length
= 0;
1124 vb
->planes
[plane
].m
.userptr
= 0;
1125 vb
->planes
[plane
].data_offset
= 0;
1127 /* Acquire each plane's memory */
1128 mem_priv
= call_ptr_memop(vb
, get_userptr
, q
->alloc_ctx
[plane
],
1129 planes
[plane
].m
.userptr
,
1130 planes
[plane
].length
, dma_dir
);
1131 if (IS_ERR_OR_NULL(mem_priv
)) {
1132 dprintk(1, "failed acquiring userspace "
1133 "memory for plane %d\n", plane
);
1134 ret
= mem_priv
? PTR_ERR(mem_priv
) : -EINVAL
;
1137 vb
->planes
[plane
].mem_priv
= mem_priv
;
1141 * Now that everything is in order, copy relevant information
1142 * provided by userspace.
1144 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1145 vb
->planes
[plane
].bytesused
= planes
[plane
].bytesused
;
1146 vb
->planes
[plane
].length
= planes
[plane
].length
;
1147 vb
->planes
[plane
].m
.userptr
= planes
[plane
].m
.userptr
;
1148 vb
->planes
[plane
].data_offset
= planes
[plane
].data_offset
;
1153 * One or more planes changed, so we must call buf_init to do
1154 * the driver-specific initialization on the newly acquired
1155 * buffer, if provided.
1157 ret
= call_vb_qop(vb
, buf_init
, vb
);
1159 dprintk(1, "buffer initialization failed\n");
1164 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1166 dprintk(1, "buffer preparation failed\n");
1167 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1173 /* In case of errors, release planes that were already acquired */
1174 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1175 if (vb
->planes
[plane
].mem_priv
)
1176 call_void_memop(vb
, put_userptr
,
1177 vb
->planes
[plane
].mem_priv
);
1178 vb
->planes
[plane
].mem_priv
= NULL
;
1179 vb
->planes
[plane
].m
.userptr
= 0;
1180 vb
->planes
[plane
].length
= 0;
1187 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1189 static int __qbuf_dmabuf(struct vb2_buffer
*vb
, const void *pb
)
1191 struct vb2_plane planes
[VB2_MAX_PLANES
];
1192 struct vb2_queue
*q
= vb
->vb2_queue
;
1196 enum dma_data_direction dma_dir
=
1197 q
->is_output
? DMA_TO_DEVICE
: DMA_FROM_DEVICE
;
1198 bool reacquired
= vb
->planes
[0].mem_priv
== NULL
;
1200 memset(planes
, 0, sizeof(planes
[0]) * vb
->num_planes
);
1201 /* Copy relevant information provided by the userspace */
1202 ret
= call_bufop(vb
->vb2_queue
, fill_vb2_buffer
, vb
, pb
, planes
);
1206 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1207 struct dma_buf
*dbuf
= dma_buf_get(planes
[plane
].m
.fd
);
1209 if (IS_ERR_OR_NULL(dbuf
)) {
1210 dprintk(1, "invalid dmabuf fd for plane %d\n",
1216 /* use DMABUF size if length is not provided */
1217 if (planes
[plane
].length
== 0)
1218 planes
[plane
].length
= dbuf
->size
;
1220 if (planes
[plane
].length
< vb
->planes
[plane
].min_length
) {
1221 dprintk(1, "invalid dmabuf length for plane %d\n",
1227 /* Skip the plane if already verified */
1228 if (dbuf
== vb
->planes
[plane
].dbuf
&&
1229 vb
->planes
[plane
].length
== planes
[plane
].length
) {
1234 dprintk(1, "buffer for plane %d changed\n", plane
);
1238 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1241 /* Release previously acquired memory if present */
1242 __vb2_plane_dmabuf_put(vb
, &vb
->planes
[plane
]);
1243 vb
->planes
[plane
].bytesused
= 0;
1244 vb
->planes
[plane
].length
= 0;
1245 vb
->planes
[plane
].m
.fd
= 0;
1246 vb
->planes
[plane
].data_offset
= 0;
1248 /* Acquire each plane's memory */
1249 mem_priv
= call_ptr_memop(vb
, attach_dmabuf
,
1250 q
->alloc_ctx
[plane
], dbuf
, planes
[plane
].length
,
1252 if (IS_ERR(mem_priv
)) {
1253 dprintk(1, "failed to attach dmabuf\n");
1254 ret
= PTR_ERR(mem_priv
);
1259 vb
->planes
[plane
].dbuf
= dbuf
;
1260 vb
->planes
[plane
].mem_priv
= mem_priv
;
1263 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1264 * really we want to do this just before the DMA, not while queueing
1267 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1268 ret
= call_memop(vb
, map_dmabuf
, vb
->planes
[plane
].mem_priv
);
1270 dprintk(1, "failed to map dmabuf for plane %d\n",
1274 vb
->planes
[plane
].dbuf_mapped
= 1;
1278 * Now that everything is in order, copy relevant information
1279 * provided by userspace.
1281 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1282 vb
->planes
[plane
].bytesused
= planes
[plane
].bytesused
;
1283 vb
->planes
[plane
].length
= planes
[plane
].length
;
1284 vb
->planes
[plane
].m
.fd
= planes
[plane
].m
.fd
;
1285 vb
->planes
[plane
].data_offset
= planes
[plane
].data_offset
;
1290 * Call driver-specific initialization on the newly acquired buffer,
1293 ret
= call_vb_qop(vb
, buf_init
, vb
);
1295 dprintk(1, "buffer initialization failed\n");
1300 ret
= call_vb_qop(vb
, buf_prepare
, vb
);
1302 dprintk(1, "buffer preparation failed\n");
1303 call_void_vb_qop(vb
, buf_cleanup
, vb
);
1309 /* In case of errors, release planes that were already acquired */
1310 __vb2_buf_dmabuf_put(vb
);
1316 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1318 static void __enqueue_in_driver(struct vb2_buffer
*vb
)
1320 struct vb2_queue
*q
= vb
->vb2_queue
;
1323 vb
->state
= VB2_BUF_STATE_ACTIVE
;
1324 atomic_inc(&q
->owned_by_drv_count
);
1326 trace_vb2_buf_queue(q
, vb
);
1329 for (plane
= 0; plane
< vb
->num_planes
; ++plane
)
1330 call_void_memop(vb
, prepare
, vb
->planes
[plane
].mem_priv
);
1332 call_void_vb_qop(vb
, buf_queue
, vb
);
1335 static int __buf_prepare(struct vb2_buffer
*vb
, const void *pb
)
1337 struct vb2_queue
*q
= vb
->vb2_queue
;
1341 dprintk(1, "fatal error occurred on queue\n");
1345 vb
->state
= VB2_BUF_STATE_PREPARING
;
1347 switch (q
->memory
) {
1348 case VB2_MEMORY_MMAP
:
1349 ret
= __qbuf_mmap(vb
, pb
);
1351 case VB2_MEMORY_USERPTR
:
1352 ret
= __qbuf_userptr(vb
, pb
);
1354 case VB2_MEMORY_DMABUF
:
1355 ret
= __qbuf_dmabuf(vb
, pb
);
1358 WARN(1, "Invalid queue type\n");
1363 dprintk(1, "buffer preparation failed: %d\n", ret
);
1364 vb
->state
= ret
? VB2_BUF_STATE_DEQUEUED
: VB2_BUF_STATE_PREPARED
;
1370 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
1372 * @q: videobuf2 queue
1373 * @index: id number of the buffer
1374 * @pb: buffer structure passed from userspace to vidioc_prepare_buf
1377 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1378 * The passed buffer should have been verified.
1379 * This function calls buf_prepare callback in the driver (if provided),
1380 * in which driver-specific buffer initialization can be performed,
1382 * The return values from this function are intended to be directly returned
1383 * from vidioc_prepare_buf handler in driver.
1385 int vb2_core_prepare_buf(struct vb2_queue
*q
, unsigned int index
, void *pb
)
1387 struct vb2_buffer
*vb
;
1390 vb
= q
->bufs
[index
];
1391 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1392 dprintk(1, "invalid buffer state %d\n",
1397 ret
= __buf_prepare(vb
, pb
);
1401 /* Fill buffer information for the userspace */
1402 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1404 dprintk(1, "prepare of buffer %d succeeded\n", vb
->index
);
1408 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf
);
1411 * vb2_start_streaming() - Attempt to start streaming.
1412 * @q: videobuf2 queue
1414 * Attempt to start streaming. When this function is called there must be
1415 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1416 * number of buffers required for the DMA engine to function). If the
1417 * @start_streaming op fails it is supposed to return all the driver-owned
1418 * buffers back to vb2 in state QUEUED. Check if that happened and if
1419 * not warn and reclaim them forcefully.
1421 static int vb2_start_streaming(struct vb2_queue
*q
)
1423 struct vb2_buffer
*vb
;
1427 * If any buffers were queued before streamon,
1428 * we can now pass them to driver for processing.
1430 list_for_each_entry(vb
, &q
->queued_list
, queued_entry
)
1431 __enqueue_in_driver(vb
);
1433 /* Tell the driver to start streaming */
1434 q
->start_streaming_called
= 1;
1435 ret
= call_qop(q
, start_streaming
, q
,
1436 atomic_read(&q
->owned_by_drv_count
));
1440 q
->start_streaming_called
= 0;
1442 dprintk(1, "driver refused to start streaming\n");
1444 * If you see this warning, then the driver isn't cleaning up properly
1445 * after a failed start_streaming(). See the start_streaming()
1446 * documentation in videobuf2-core.h for more information how buffers
1447 * should be returned to vb2 in start_streaming().
1449 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1453 * Forcefully reclaim buffers if the driver did not
1454 * correctly return them to vb2.
1456 for (i
= 0; i
< q
->num_buffers
; ++i
) {
1458 if (vb
->state
== VB2_BUF_STATE_ACTIVE
)
1459 vb2_buffer_done(vb
, VB2_BUF_STATE_QUEUED
);
1461 /* Must be zero now */
1462 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1465 * If done_list is not empty, then start_streaming() didn't call
1466 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1469 WARN_ON(!list_empty(&q
->done_list
));
1474 * vb2_core_qbuf() - Queue a buffer from userspace
1475 * @q: videobuf2 queue
1476 * @index: id number of the buffer
1477 * @pb: buffer structure passed from userspace to vidioc_qbuf handler
1480 * Should be called from vidioc_qbuf ioctl handler of a driver.
1481 * The passed buffer should have been verified.
1483 * 1) if necessary, calls buf_prepare callback in the driver (if provided), in
1484 * which driver-specific buffer initialization can be performed,
1485 * 2) if streaming is on, queues the buffer in driver by the means of buf_queue
1486 * callback for processing.
1488 * The return values from this function are intended to be directly returned
1489 * from vidioc_qbuf handler in driver.
1491 int vb2_core_qbuf(struct vb2_queue
*q
, unsigned int index
, void *pb
)
1493 struct vb2_buffer
*vb
;
1496 vb
= q
->bufs
[index
];
1498 switch (vb
->state
) {
1499 case VB2_BUF_STATE_DEQUEUED
:
1500 ret
= __buf_prepare(vb
, pb
);
1504 case VB2_BUF_STATE_PREPARED
:
1506 case VB2_BUF_STATE_PREPARING
:
1507 dprintk(1, "buffer still being prepared\n");
1510 dprintk(1, "invalid buffer state %d\n", vb
->state
);
1515 * Add to the queued buffers list, a buffer will stay on it until
1516 * dequeued in dqbuf.
1518 list_add_tail(&vb
->queued_entry
, &q
->queued_list
);
1520 q
->waiting_for_buffers
= false;
1521 vb
->state
= VB2_BUF_STATE_QUEUED
;
1523 call_void_bufop(q
, copy_timestamp
, vb
, pb
);
1525 trace_vb2_qbuf(q
, vb
);
1528 * If already streaming, give the buffer to driver for processing.
1529 * If not, the buffer will be given to driver on next streamon.
1531 if (q
->start_streaming_called
)
1532 __enqueue_in_driver(vb
);
1534 /* Fill buffer information for the userspace */
1535 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1538 * If streamon has been called, and we haven't yet called
1539 * start_streaming() since not enough buffers were queued, and
1540 * we now have reached the minimum number of queued buffers,
1541 * then we can finally call start_streaming().
1543 if (q
->streaming
&& !q
->start_streaming_called
&&
1544 q
->queued_count
>= q
->min_buffers_needed
) {
1545 ret
= vb2_start_streaming(q
);
1550 dprintk(1, "qbuf of buffer %d succeeded\n", vb
->index
);
1553 EXPORT_SYMBOL_GPL(vb2_core_qbuf
);
1556 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1559 * Will sleep if required for nonblocking == false.
1561 static int __vb2_wait_for_done_vb(struct vb2_queue
*q
, int nonblocking
)
1564 * All operations on vb_done_list are performed under done_lock
1565 * spinlock protection. However, buffers may be removed from
1566 * it and returned to userspace only while holding both driver's
1567 * lock and the done_lock spinlock. Thus we can be sure that as
1568 * long as we hold the driver's lock, the list will remain not
1569 * empty if list_empty() check succeeds.
1575 if (!q
->streaming
) {
1576 dprintk(1, "streaming off, will not wait for buffers\n");
1581 dprintk(1, "Queue in error state, will not wait for buffers\n");
1585 if (q
->last_buffer_dequeued
) {
1586 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1590 if (!list_empty(&q
->done_list
)) {
1592 * Found a buffer that we were waiting for.
1598 dprintk(1, "nonblocking and no buffers to dequeue, "
1604 * We are streaming and blocking, wait for another buffer to
1605 * become ready or for streamoff. Driver's lock is released to
1606 * allow streamoff or qbuf to be called while waiting.
1608 call_void_qop(q
, wait_prepare
, q
);
1611 * All locks have been released, it is safe to sleep now.
1613 dprintk(3, "will sleep waiting for buffers\n");
1614 ret
= wait_event_interruptible(q
->done_wq
,
1615 !list_empty(&q
->done_list
) || !q
->streaming
||
1619 * We need to reevaluate both conditions again after reacquiring
1620 * the locks or return an error if one occurred.
1622 call_void_qop(q
, wait_finish
, q
);
1624 dprintk(1, "sleep was interrupted\n");
1632 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1634 * Will sleep if required for nonblocking == false.
1636 static int __vb2_get_done_vb(struct vb2_queue
*q
, struct vb2_buffer
**vb
,
1639 unsigned long flags
;
1643 * Wait for at least one buffer to become available on the done_list.
1645 ret
= __vb2_wait_for_done_vb(q
, nonblocking
);
1650 * Driver's lock has been held since we last verified that done_list
1651 * is not empty, so no need for another list_empty(done_list) check.
1653 spin_lock_irqsave(&q
->done_lock
, flags
);
1654 *vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
, done_entry
);
1656 * Only remove the buffer from done_list if v4l2_buffer can handle all
1658 * Verifying planes is NOT necessary since it already has been checked
1659 * before the buffer is queued/prepared. So it can never fail.
1661 list_del(&(*vb
)->done_entry
);
1662 spin_unlock_irqrestore(&q
->done_lock
, flags
);
1668 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1669 * @q: videobuf2 queue
1671 * This function will wait until all buffers that have been given to the driver
1672 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1673 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1674 * taken, for example from stop_streaming() callback.
1676 int vb2_wait_for_all_buffers(struct vb2_queue
*q
)
1678 if (!q
->streaming
) {
1679 dprintk(1, "streaming off, will not wait for buffers\n");
1683 if (q
->start_streaming_called
)
1684 wait_event(q
->done_wq
, !atomic_read(&q
->owned_by_drv_count
));
1687 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers
);
1690 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1692 static void __vb2_dqbuf(struct vb2_buffer
*vb
)
1694 struct vb2_queue
*q
= vb
->vb2_queue
;
1697 /* nothing to do if the buffer is already dequeued */
1698 if (vb
->state
== VB2_BUF_STATE_DEQUEUED
)
1701 vb
->state
= VB2_BUF_STATE_DEQUEUED
;
1703 /* unmap DMABUF buffer */
1704 if (q
->memory
== VB2_MEMORY_DMABUF
)
1705 for (i
= 0; i
< vb
->num_planes
; ++i
) {
1706 if (!vb
->planes
[i
].dbuf_mapped
)
1708 call_void_memop(vb
, unmap_dmabuf
, vb
->planes
[i
].mem_priv
);
1709 vb
->planes
[i
].dbuf_mapped
= 0;
1714 * vb2_dqbuf() - Dequeue a buffer to the userspace
1715 * @q: videobuf2 queue
1716 * @pb: buffer structure passed from userspace to vidioc_dqbuf handler
1718 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
1719 * buffers ready for dequeuing are present. Normally the driver
1720 * would be passing (file->f_flags & O_NONBLOCK) here
1722 * Should be called from vidioc_dqbuf ioctl handler of a driver.
1723 * The passed buffer should have been verified.
1725 * 1) calls buf_finish callback in the driver (if provided), in which
1726 * driver can perform any additional operations that may be required before
1727 * returning the buffer to userspace, such as cache sync,
1728 * 2) the buffer struct members are filled with relevant information for
1731 * The return values from this function are intended to be directly returned
1732 * from vidioc_dqbuf handler in driver.
1734 int vb2_core_dqbuf(struct vb2_queue
*q
, void *pb
, bool nonblocking
)
1736 struct vb2_buffer
*vb
= NULL
;
1739 ret
= __vb2_get_done_vb(q
, &vb
, nonblocking
);
1743 switch (vb
->state
) {
1744 case VB2_BUF_STATE_DONE
:
1745 dprintk(3, "returning done buffer\n");
1747 case VB2_BUF_STATE_ERROR
:
1748 dprintk(3, "returning done buffer with errors\n");
1751 dprintk(1, "invalid buffer state\n");
1755 call_void_vb_qop(vb
, buf_finish
, vb
);
1757 /* Fill buffer information for the userspace */
1758 call_void_bufop(q
, fill_user_buffer
, vb
, pb
);
1760 /* Remove from videobuf queue */
1761 list_del(&vb
->queued_entry
);
1764 trace_vb2_dqbuf(q
, vb
);
1766 /* go back to dequeued state */
1769 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1770 vb
->index
, vb
->state
);
1775 EXPORT_SYMBOL_GPL(vb2_core_dqbuf
);
1778 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1780 * Removes all queued buffers from driver's queue and all buffers queued by
1781 * userspace from videobuf's queue. Returns to state after reqbufs.
1783 static void __vb2_queue_cancel(struct vb2_queue
*q
)
1788 * Tell driver to stop all transactions and release all queued
1791 if (q
->start_streaming_called
)
1792 call_void_qop(q
, stop_streaming
, q
);
1795 * If you see this warning, then the driver isn't cleaning up properly
1796 * in stop_streaming(). See the stop_streaming() documentation in
1797 * videobuf2-core.h for more information how buffers should be returned
1798 * to vb2 in stop_streaming().
1800 if (WARN_ON(atomic_read(&q
->owned_by_drv_count
))) {
1801 for (i
= 0; i
< q
->num_buffers
; ++i
)
1802 if (q
->bufs
[i
]->state
== VB2_BUF_STATE_ACTIVE
)
1803 vb2_buffer_done(q
->bufs
[i
], VB2_BUF_STATE_ERROR
);
1804 /* Must be zero now */
1805 WARN_ON(atomic_read(&q
->owned_by_drv_count
));
1809 q
->start_streaming_called
= 0;
1810 q
->queued_count
= 0;
1814 * Remove all buffers from videobuf's list...
1816 INIT_LIST_HEAD(&q
->queued_list
);
1818 * ...and done list; userspace will not receive any buffers it
1819 * has not already dequeued before initiating cancel.
1821 INIT_LIST_HEAD(&q
->done_list
);
1822 atomic_set(&q
->owned_by_drv_count
, 0);
1823 wake_up_all(&q
->done_wq
);
1826 * Reinitialize all buffers for next use.
1827 * Make sure to call buf_finish for any queued buffers. Normally
1828 * that's done in dqbuf, but that's not going to happen when we
1829 * cancel the whole queue. Note: this code belongs here, not in
1830 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
1831 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
1832 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1834 for (i
= 0; i
< q
->num_buffers
; ++i
) {
1835 struct vb2_buffer
*vb
= q
->bufs
[i
];
1837 if (vb
->state
!= VB2_BUF_STATE_DEQUEUED
) {
1838 vb
->state
= VB2_BUF_STATE_PREPARED
;
1839 call_void_vb_qop(vb
, buf_finish
, vb
);
1845 int vb2_core_streamon(struct vb2_queue
*q
, unsigned int type
)
1849 if (type
!= q
->type
) {
1850 dprintk(1, "invalid stream type\n");
1855 dprintk(3, "already streaming\n");
1859 if (!q
->num_buffers
) {
1860 dprintk(1, "no buffers have been allocated\n");
1864 if (q
->num_buffers
< q
->min_buffers_needed
) {
1865 dprintk(1, "need at least %u allocated buffers\n",
1866 q
->min_buffers_needed
);
1871 * Tell driver to start streaming provided sufficient buffers
1874 if (q
->queued_count
>= q
->min_buffers_needed
) {
1875 ret
= vb2_start_streaming(q
);
1877 __vb2_queue_cancel(q
);
1884 dprintk(3, "successful\n");
1887 EXPORT_SYMBOL_GPL(vb2_core_streamon
);
1890 * vb2_queue_error() - signal a fatal error on the queue
1891 * @q: videobuf2 queue
1893 * Flag that a fatal unrecoverable error has occurred and wake up all processes
1894 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
1895 * buffers will return -EIO.
1897 * The error flag will be cleared when cancelling the queue, either from
1898 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
1899 * function before starting the stream, otherwise the error flag will remain set
1900 * until the queue is released when closing the device node.
1902 void vb2_queue_error(struct vb2_queue
*q
)
1906 wake_up_all(&q
->done_wq
);
1908 EXPORT_SYMBOL_GPL(vb2_queue_error
);
1910 int vb2_core_streamoff(struct vb2_queue
*q
, unsigned int type
)
1912 if (type
!= q
->type
) {
1913 dprintk(1, "invalid stream type\n");
1918 * Cancel will pause streaming and remove all buffers from the driver
1919 * and videobuf, effectively returning control over them to userspace.
1921 * Note that we do this even if q->streaming == 0: if you prepare or
1922 * queue buffers, and then call streamoff without ever having called
1923 * streamon, you would still expect those buffers to be returned to
1924 * their normal dequeued state.
1926 __vb2_queue_cancel(q
);
1927 q
->waiting_for_buffers
= !q
->is_output
;
1928 q
->last_buffer_dequeued
= false;
1930 dprintk(3, "successful\n");
1933 EXPORT_SYMBOL_GPL(vb2_core_streamoff
);
1936 * __find_plane_by_offset() - find plane associated with the given offset off
1938 static int __find_plane_by_offset(struct vb2_queue
*q
, unsigned long off
,
1939 unsigned int *_buffer
, unsigned int *_plane
)
1941 struct vb2_buffer
*vb
;
1942 unsigned int buffer
, plane
;
1945 * Go over all buffers and their planes, comparing the given offset
1946 * with an offset assigned to each plane. If a match is found,
1947 * return its buffer and plane numbers.
1949 for (buffer
= 0; buffer
< q
->num_buffers
; ++buffer
) {
1950 vb
= q
->bufs
[buffer
];
1952 for (plane
= 0; plane
< vb
->num_planes
; ++plane
) {
1953 if (vb
->planes
[plane
].m
.offset
== off
) {
1965 * vb2_core_expbuf() - Export a buffer as a file descriptor
1966 * @q: videobuf2 queue
1967 * @fd: file descriptor associated with DMABUF (set by driver) *
1968 * @type: buffer type
1969 * @index: id number of the buffer
1970 * @plane: index of the plane to be exported, 0 for single plane queues
1971 * @flags: flags for newly created file, currently only O_CLOEXEC is
1972 * supported, refer to manual of open syscall for more details
1974 * The return values from this function are intended to be directly returned
1975 * from vidioc_expbuf handler in driver.
1977 int vb2_core_expbuf(struct vb2_queue
*q
, int *fd
, unsigned int type
,
1978 unsigned int index
, unsigned int plane
, unsigned int flags
)
1980 struct vb2_buffer
*vb
= NULL
;
1981 struct vb2_plane
*vb_plane
;
1983 struct dma_buf
*dbuf
;
1985 if (q
->memory
!= VB2_MEMORY_MMAP
) {
1986 dprintk(1, "queue is not currently set up for mmap\n");
1990 if (!q
->mem_ops
->get_dmabuf
) {
1991 dprintk(1, "queue does not support DMA buffer exporting\n");
1995 if (flags
& ~(O_CLOEXEC
| O_ACCMODE
)) {
1996 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
2000 if (type
!= q
->type
) {
2001 dprintk(1, "invalid buffer type\n");
2005 if (index
>= q
->num_buffers
) {
2006 dprintk(1, "buffer index out of range\n");
2010 vb
= q
->bufs
[index
];
2012 if (plane
>= vb
->num_planes
) {
2013 dprintk(1, "buffer plane out of range\n");
2017 if (vb2_fileio_is_active(q
)) {
2018 dprintk(1, "expbuf: file io in progress\n");
2022 vb_plane
= &vb
->planes
[plane
];
2024 dbuf
= call_ptr_memop(vb
, get_dmabuf
, vb_plane
->mem_priv
,
2026 if (IS_ERR_OR_NULL(dbuf
)) {
2027 dprintk(1, "failed to export buffer %d, plane %d\n",
2032 ret
= dma_buf_fd(dbuf
, flags
& ~O_ACCMODE
);
2034 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
2040 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
2046 EXPORT_SYMBOL_GPL(vb2_core_expbuf
);
2049 * vb2_mmap() - map video buffers into application address space
2050 * @q: videobuf2 queue
2051 * @vma: vma passed to the mmap file operation handler in the driver
2053 * Should be called from mmap file operation handler of a driver.
2054 * This function maps one plane of one of the available video buffers to
2055 * userspace. To map whole video memory allocated on reqbufs, this function
2056 * has to be called once per each plane per each buffer previously allocated.
2058 * When the userspace application calls mmap, it passes to it an offset returned
2059 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
2060 * a "cookie", which is then used to identify the plane to be mapped.
2061 * This function finds a plane with a matching offset and a mapping is performed
2062 * by the means of a provided memory operation.
2064 * The return values from this function are intended to be directly returned
2065 * from the mmap handler in driver.
2067 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
)
2069 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
2070 struct vb2_buffer
*vb
;
2071 unsigned int buffer
= 0, plane
= 0;
2073 unsigned long length
;
2075 if (q
->memory
!= VB2_MEMORY_MMAP
) {
2076 dprintk(1, "queue is not currently set up for mmap\n");
2081 * Check memory area access mode.
2083 if (!(vma
->vm_flags
& VM_SHARED
)) {
2084 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
2088 if (!(vma
->vm_flags
& VM_WRITE
)) {
2089 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
2093 if (!(vma
->vm_flags
& VM_READ
)) {
2094 dprintk(1, "invalid vma flags, VM_READ needed\n");
2098 if (vb2_fileio_is_active(q
)) {
2099 dprintk(1, "mmap: file io in progress\n");
2104 * Find the plane corresponding to the offset passed by userspace.
2106 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2110 vb
= q
->bufs
[buffer
];
2113 * MMAP requires page_aligned buffers.
2114 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
2115 * so, we need to do the same here.
2117 length
= PAGE_ALIGN(vb
->planes
[plane
].length
);
2118 if (length
< (vma
->vm_end
- vma
->vm_start
)) {
2120 "MMAP invalid, as it would overflow buffer length\n");
2124 mutex_lock(&q
->mmap_lock
);
2125 ret
= call_memop(vb
, mmap
, vb
->planes
[plane
].mem_priv
, vma
);
2126 mutex_unlock(&q
->mmap_lock
);
2130 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer
, plane
);
2133 EXPORT_SYMBOL_GPL(vb2_mmap
);
2136 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
2139 unsigned long pgoff
,
2140 unsigned long flags
)
2142 unsigned long off
= pgoff
<< PAGE_SHIFT
;
2143 struct vb2_buffer
*vb
;
2144 unsigned int buffer
, plane
;
2148 if (q
->memory
!= VB2_MEMORY_MMAP
) {
2149 dprintk(1, "queue is not currently set up for mmap\n");
2154 * Find the plane corresponding to the offset passed by userspace.
2156 ret
= __find_plane_by_offset(q
, off
, &buffer
, &plane
);
2160 vb
= q
->bufs
[buffer
];
2162 vaddr
= vb2_plane_vaddr(vb
, plane
);
2163 return vaddr
? (unsigned long)vaddr
: -EINVAL
;
2165 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area
);
2169 * vb2_core_queue_init() - initialize a videobuf2 queue
2170 * @q: videobuf2 queue; this structure should be allocated in driver
2172 * The vb2_queue structure should be allocated by the driver. The driver is
2173 * responsible of clearing it's content and setting initial values for some
2174 * required entries before calling this function.
2175 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2176 * to the struct vb2_queue description in include/media/videobuf2-core.h
2177 * for more information.
2179 int vb2_core_queue_init(struct vb2_queue
*q
)
2186 WARN_ON(!q
->mem_ops
) ||
2187 WARN_ON(!q
->type
) ||
2188 WARN_ON(!q
->io_modes
) ||
2189 WARN_ON(!q
->ops
->queue_setup
) ||
2190 WARN_ON(!q
->ops
->buf_queue
))
2193 INIT_LIST_HEAD(&q
->queued_list
);
2194 INIT_LIST_HEAD(&q
->done_list
);
2195 spin_lock_init(&q
->done_lock
);
2196 mutex_init(&q
->mmap_lock
);
2197 init_waitqueue_head(&q
->done_wq
);
2199 if (q
->buf_struct_size
== 0)
2200 q
->buf_struct_size
= sizeof(struct vb2_buffer
);
2204 EXPORT_SYMBOL_GPL(vb2_core_queue_init
);
2206 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
);
2207 static int __vb2_cleanup_fileio(struct vb2_queue
*q
);
2209 * vb2_core_queue_release() - stop streaming, release the queue and free memory
2210 * @q: videobuf2 queue
2212 * This function stops streaming and performs necessary clean ups, including
2213 * freeing video buffer memory. The driver is responsible for freeing
2214 * the vb2_queue structure itself.
2216 void vb2_core_queue_release(struct vb2_queue
*q
)
2218 __vb2_cleanup_fileio(q
);
2219 __vb2_queue_cancel(q
);
2220 mutex_lock(&q
->mmap_lock
);
2221 __vb2_queue_free(q
, q
->num_buffers
);
2222 mutex_unlock(&q
->mmap_lock
);
2224 EXPORT_SYMBOL_GPL(vb2_core_queue_release
);
2227 * vb2_core_poll() - implements poll userspace operation
2228 * @q: videobuf2 queue
2229 * @file: file argument passed to the poll file operation handler
2230 * @wait: wait argument passed to the poll file operation handler
2232 * This function implements poll file operation handler for a driver.
2233 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2234 * be informed that the file descriptor of a video device is available for
2236 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2237 * will be reported as available for writing.
2239 * The return values from this function are intended to be directly returned
2240 * from poll handler in driver.
2242 unsigned int vb2_core_poll(struct vb2_queue
*q
, struct file
*file
,
2245 unsigned long req_events
= poll_requested_events(wait
);
2246 struct vb2_buffer
*vb
= NULL
;
2247 unsigned long flags
;
2249 if (!q
->is_output
&& !(req_events
& (POLLIN
| POLLRDNORM
)))
2251 if (q
->is_output
&& !(req_events
& (POLLOUT
| POLLWRNORM
)))
2255 * Start file I/O emulator only if streaming API has not been used yet.
2257 if (q
->num_buffers
== 0 && !vb2_fileio_is_active(q
)) {
2258 if (!q
->is_output
&& (q
->io_modes
& VB2_READ
) &&
2259 (req_events
& (POLLIN
| POLLRDNORM
))) {
2260 if (__vb2_init_fileio(q
, 1))
2263 if (q
->is_output
&& (q
->io_modes
& VB2_WRITE
) &&
2264 (req_events
& (POLLOUT
| POLLWRNORM
))) {
2265 if (__vb2_init_fileio(q
, 0))
2268 * Write to OUTPUT queue can be done immediately.
2270 return POLLOUT
| POLLWRNORM
;
2275 * There is nothing to wait for if the queue isn't streaming, or if the
2276 * error flag is set.
2278 if (!vb2_is_streaming(q
) || q
->error
)
2282 * For output streams you can call write() as long as there are fewer
2283 * buffers queued than there are buffers available.
2285 if (q
->is_output
&& q
->fileio
&& q
->queued_count
< q
->num_buffers
)
2286 return POLLOUT
| POLLWRNORM
;
2288 if (list_empty(&q
->done_list
)) {
2290 * If the last buffer was dequeued from a capture queue,
2291 * return immediately. DQBUF will return -EPIPE.
2293 if (q
->last_buffer_dequeued
)
2294 return POLLIN
| POLLRDNORM
;
2296 poll_wait(file
, &q
->done_wq
, wait
);
2300 * Take first buffer available for dequeuing.
2302 spin_lock_irqsave(&q
->done_lock
, flags
);
2303 if (!list_empty(&q
->done_list
))
2304 vb
= list_first_entry(&q
->done_list
, struct vb2_buffer
,
2306 spin_unlock_irqrestore(&q
->done_lock
, flags
);
2308 if (vb
&& (vb
->state
== VB2_BUF_STATE_DONE
2309 || vb
->state
== VB2_BUF_STATE_ERROR
)) {
2310 return (q
->is_output
) ?
2311 POLLOUT
| POLLWRNORM
:
2312 POLLIN
| POLLRDNORM
;
2316 EXPORT_SYMBOL_GPL(vb2_core_poll
);
2319 * struct vb2_fileio_buf - buffer context used by file io emulator
2321 * vb2 provides a compatibility layer and emulator of file io (read and
2322 * write) calls on top of streaming API. This structure is used for
2323 * tracking context related to the buffers.
2325 struct vb2_fileio_buf
{
2329 unsigned int queued
:1;
2333 * struct vb2_fileio_data - queue context used by file io emulator
2335 * @cur_index: the index of the buffer currently being read from or
2336 * written to. If equal to q->num_buffers then a new buffer
2338 * @initial_index: in the read() case all buffers are queued up immediately
2339 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2340 * buffers. However, in the write() case no buffers are initially
2341 * queued, instead whenever a buffer is full it is queued up by
2342 * __vb2_perform_fileio(). Only once all available buffers have
2343 * been queued up will __vb2_perform_fileio() start to dequeue
2344 * buffers. This means that initially __vb2_perform_fileio()
2345 * needs to know what buffer index to use when it is queuing up
2346 * the buffers for the first time. That initial index is stored
2347 * in this field. Once it is equal to q->num_buffers all
2348 * available buffers have been queued and __vb2_perform_fileio()
2349 * should start the normal dequeue/queue cycle.
2351 * vb2 provides a compatibility layer and emulator of file io (read and
2352 * write) calls on top of streaming API. For proper operation it required
2353 * this structure to save the driver state between each call of the read
2354 * or write function.
2356 struct vb2_fileio_data
{
2359 unsigned int memory
;
2360 struct vb2_buffer
*b
;
2361 struct vb2_fileio_buf bufs
[VB2_MAX_FRAME
];
2362 unsigned int cur_index
;
2363 unsigned int initial_index
;
2364 unsigned int q_count
;
2365 unsigned int dq_count
;
2366 unsigned read_once
:1;
2367 unsigned write_immediately
:1;
2371 * __vb2_init_fileio() - initialize file io emulator
2372 * @q: videobuf2 queue
2373 * @read: mode selector (1 means read, 0 means write)
2375 static int __vb2_init_fileio(struct vb2_queue
*q
, int read
)
2377 struct vb2_fileio_data
*fileio
;
2379 unsigned int count
= 0;
2384 if (WARN_ON((read
&& !(q
->io_modes
& VB2_READ
)) ||
2385 (!read
&& !(q
->io_modes
& VB2_WRITE
))))
2389 * Check if device supports mapping buffers to kernel virtual space.
2391 if (!q
->mem_ops
->vaddr
)
2395 * Check if streaming api has not been already activated.
2397 if (q
->streaming
|| q
->num_buffers
> 0)
2401 * Start with count 1, driver can increase it in queue_setup()
2405 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2406 (read
) ? "read" : "write", count
, q
->fileio_read_once
,
2407 q
->fileio_write_immediately
);
2409 fileio
= kzalloc(sizeof(*fileio
), GFP_KERNEL
);
2413 fileio
->b
= kzalloc(q
->buf_struct_size
, GFP_KERNEL
);
2414 if (fileio
->b
== NULL
) {
2419 fileio
->read_once
= q
->fileio_read_once
;
2420 fileio
->write_immediately
= q
->fileio_write_immediately
;
2423 * Request buffers and use MMAP type to force driver
2424 * to allocate buffers by itself.
2426 fileio
->count
= count
;
2427 fileio
->memory
= VB2_MEMORY_MMAP
;
2428 fileio
->type
= q
->type
;
2430 ret
= vb2_core_reqbufs(q
, fileio
->memory
, &fileio
->count
);
2435 * Check if plane_count is correct
2436 * (multiplane buffers are not supported).
2438 if (q
->bufs
[0]->num_planes
!= 1) {
2444 * Get kernel address of each buffer.
2446 for (i
= 0; i
< q
->num_buffers
; i
++) {
2447 fileio
->bufs
[i
].vaddr
= vb2_plane_vaddr(q
->bufs
[i
], 0);
2448 if (fileio
->bufs
[i
].vaddr
== NULL
) {
2452 fileio
->bufs
[i
].size
= vb2_plane_size(q
->bufs
[i
], 0);
2456 * Read mode requires pre queuing of all buffers.
2460 * Queue all buffers.
2462 for (i
= 0; i
< q
->num_buffers
; i
++) {
2463 struct vb2_buffer
*b
= fileio
->b
;
2465 memset(b
, 0, q
->buf_struct_size
);
2467 b
->memory
= q
->memory
;
2469 ret
= vb2_core_qbuf(q
, i
, b
);
2472 fileio
->bufs
[i
].queued
= 1;
2475 * All buffers have been queued, so mark that by setting
2476 * initial_index to q->num_buffers
2478 fileio
->initial_index
= q
->num_buffers
;
2479 fileio
->cur_index
= q
->num_buffers
;
2485 ret
= vb2_core_streamon(q
, q
->type
);
2493 vb2_core_reqbufs(q
, fileio
->memory
, &fileio
->count
);
2502 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2503 * @q: videobuf2 queue
2505 static int __vb2_cleanup_fileio(struct vb2_queue
*q
)
2507 struct vb2_fileio_data
*fileio
= q
->fileio
;
2510 vb2_core_streamoff(q
, q
->type
);
2513 vb2_core_reqbufs(q
, fileio
->memory
, &fileio
->count
);
2516 dprintk(3, "file io emulator closed\n");
2522 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2523 * @q: videobuf2 queue
2524 * @data: pointed to target userspace buffer
2525 * @count: number of bytes to read or write
2526 * @ppos: file handle position tracking pointer
2527 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2528 * @read: access mode selector (1 means read, 0 means write)
2530 static size_t __vb2_perform_fileio(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2531 loff_t
*ppos
, int nonblock
, int read
)
2533 struct vb2_fileio_data
*fileio
;
2534 struct vb2_fileio_buf
*buf
;
2535 bool is_multiplanar
= q
->is_multiplanar
;
2537 * When using write() to write data to an output video node the vb2 core
2538 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2539 * else is able to provide this information with the write() operation.
2541 bool copy_timestamp
= !read
&& q
->copy_timestamp
;
2544 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2545 read
? "read" : "write", (long)*ppos
, count
,
2546 nonblock
? "non" : "");
2552 * Initialize emulator on first call.
2554 if (!vb2_fileio_is_active(q
)) {
2555 ret
= __vb2_init_fileio(q
, read
);
2556 dprintk(3, "vb2_init_fileio result: %d\n", ret
);
2563 * Check if we need to dequeue the buffer.
2565 index
= fileio
->cur_index
;
2566 if (index
>= q
->num_buffers
) {
2567 struct vb2_buffer
*b
= fileio
->b
;
2570 * Call vb2_dqbuf to get buffer back.
2572 memset(b
, 0, q
->buf_struct_size
);
2574 b
->memory
= q
->memory
;
2575 ret
= vb2_core_dqbuf(q
, b
, nonblock
);
2576 dprintk(5, "vb2_dqbuf result: %d\n", ret
);
2579 fileio
->dq_count
+= 1;
2581 fileio
->cur_index
= index
= b
->index
;
2582 buf
= &fileio
->bufs
[index
];
2585 * Get number of bytes filled by the driver
2589 buf
->size
= read
? vb2_get_plane_payload(q
->bufs
[index
], 0)
2590 : vb2_plane_size(q
->bufs
[index
], 0);
2591 /* Compensate for data_offset on read in the multiplanar case. */
2592 if (is_multiplanar
&& read
&&
2593 b
->planes
[0].data_offset
< buf
->size
) {
2594 buf
->pos
= b
->planes
[0].data_offset
;
2595 buf
->size
-= buf
->pos
;
2598 buf
= &fileio
->bufs
[index
];
2602 * Limit count on last few bytes of the buffer.
2604 if (buf
->pos
+ count
> buf
->size
) {
2605 count
= buf
->size
- buf
->pos
;
2606 dprintk(5, "reducing read count: %zd\n", count
);
2610 * Transfer data to userspace.
2612 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2613 count
, index
, buf
->pos
);
2615 ret
= copy_to_user(data
, buf
->vaddr
+ buf
->pos
, count
);
2617 ret
= copy_from_user(buf
->vaddr
+ buf
->pos
, data
, count
);
2619 dprintk(3, "error copying data\n");
2630 * Queue next buffer if required.
2632 if (buf
->pos
== buf
->size
|| (!read
&& fileio
->write_immediately
)) {
2633 struct vb2_buffer
*b
= fileio
->b
;
2636 * Check if this is the last buffer to read.
2638 if (read
&& fileio
->read_once
&& fileio
->dq_count
== 1) {
2639 dprintk(3, "read limit reached\n");
2640 return __vb2_cleanup_fileio(q
);
2644 * Call vb2_qbuf and give buffer to the driver.
2646 memset(b
, 0, q
->buf_struct_size
);
2648 b
->memory
= q
->memory
;
2650 b
->planes
[0].bytesused
= buf
->pos
;
2653 b
->timestamp
= ktime_get_ns();
2654 ret
= vb2_core_qbuf(q
, index
, b
);
2655 dprintk(5, "vb2_dbuf result: %d\n", ret
);
2660 * Buffer has been queued, update the status
2664 buf
->size
= vb2_plane_size(q
->bufs
[index
], 0);
2665 fileio
->q_count
+= 1;
2667 * If we are queuing up buffers for the first time, then
2668 * increase initial_index by one.
2670 if (fileio
->initial_index
< q
->num_buffers
)
2671 fileio
->initial_index
++;
2673 * The next buffer to use is either a buffer that's going to be
2674 * queued for the first time (initial_index < q->num_buffers)
2675 * or it is equal to q->num_buffers, meaning that the next
2676 * time we need to dequeue a buffer since we've now queued up
2677 * all the 'first time' buffers.
2679 fileio
->cur_index
= fileio
->initial_index
;
2683 * Return proper number of bytes processed.
2690 size_t vb2_read(struct vb2_queue
*q
, char __user
*data
, size_t count
,
2691 loff_t
*ppos
, int nonblocking
)
2693 return __vb2_perform_fileio(q
, data
, count
, ppos
, nonblocking
, 1);
2695 EXPORT_SYMBOL_GPL(vb2_read
);
2697 size_t vb2_write(struct vb2_queue
*q
, const char __user
*data
, size_t count
,
2698 loff_t
*ppos
, int nonblocking
)
2700 return __vb2_perform_fileio(q
, (char __user
*) data
, count
,
2701 ppos
, nonblocking
, 0);
2703 EXPORT_SYMBOL_GPL(vb2_write
);
2705 struct vb2_threadio_data
{
2706 struct task_struct
*thread
;
2712 static int vb2_thread(void *data
)
2714 struct vb2_queue
*q
= data
;
2715 struct vb2_threadio_data
*threadio
= q
->threadio
;
2716 struct vb2_fileio_data
*fileio
= q
->fileio
;
2717 bool copy_timestamp
= false;
2723 prequeue
= q
->num_buffers
;
2724 copy_timestamp
= q
->copy_timestamp
;
2730 struct vb2_buffer
*vb
;
2731 struct vb2_buffer
*b
= fileio
->b
;
2734 * Call vb2_dqbuf to get buffer back.
2736 memset(b
, 0, q
->buf_struct_size
);
2738 b
->memory
= q
->memory
;
2743 call_void_qop(q
, wait_finish
, q
);
2744 if (!threadio
->stop
)
2745 ret
= vb2_core_dqbuf(q
, b
, 0);
2746 call_void_qop(q
, wait_prepare
, q
);
2747 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret
);
2749 if (ret
|| threadio
->stop
)
2753 vb
= q
->bufs
[b
->index
];
2754 if (b
->state
== VB2_BUF_STATE_DONE
)
2755 if (threadio
->fnc(vb
, threadio
->priv
))
2757 call_void_qop(q
, wait_finish
, q
);
2759 b
->timestamp
= ktime_get_ns();;
2760 if (!threadio
->stop
)
2761 ret
= vb2_core_qbuf(q
, b
->index
, b
);
2762 call_void_qop(q
, wait_prepare
, q
);
2763 if (ret
|| threadio
->stop
)
2767 /* Hmm, linux becomes *very* unhappy without this ... */
2768 while (!kthread_should_stop()) {
2769 set_current_state(TASK_INTERRUPTIBLE
);
2776 * This function should not be used for anything else but the videobuf2-dvb
2777 * support. If you think you have another good use-case for this, then please
2778 * contact the linux-media mailinglist first.
2780 int vb2_thread_start(struct vb2_queue
*q
, vb2_thread_fnc fnc
, void *priv
,
2781 const char *thread_name
)
2783 struct vb2_threadio_data
*threadio
;
2790 if (WARN_ON(q
->fileio
))
2793 threadio
= kzalloc(sizeof(*threadio
), GFP_KERNEL
);
2794 if (threadio
== NULL
)
2796 threadio
->fnc
= fnc
;
2797 threadio
->priv
= priv
;
2799 ret
= __vb2_init_fileio(q
, !q
->is_output
);
2800 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret
);
2803 q
->threadio
= threadio
;
2804 threadio
->thread
= kthread_run(vb2_thread
, q
, "vb2-%s", thread_name
);
2805 if (IS_ERR(threadio
->thread
)) {
2806 ret
= PTR_ERR(threadio
->thread
);
2807 threadio
->thread
= NULL
;
2813 __vb2_cleanup_fileio(q
);
2818 EXPORT_SYMBOL_GPL(vb2_thread_start
);
2820 int vb2_thread_stop(struct vb2_queue
*q
)
2822 struct vb2_threadio_data
*threadio
= q
->threadio
;
2825 if (threadio
== NULL
)
2827 threadio
->stop
= true;
2828 /* Wake up all pending sleeps in the thread */
2830 err
= kthread_stop(threadio
->thread
);
2831 __vb2_cleanup_fileio(q
);
2832 threadio
->thread
= NULL
;
2837 EXPORT_SYMBOL_GPL(vb2_thread_stop
);
2839 MODULE_DESCRIPTION("Media buffer core framework");
2840 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2841 MODULE_LICENSE("GPL");