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>
28 #include <media/v4l2-mc.h>
30 #include <trace/events/vb2.h>
33 module_param(debug, int, 0644);
35 #define dprintk(level, fmt, arg...) \
38 pr_info("vb2-core: %s: " fmt, __func__, ## arg); \
41 #ifdef CONFIG_VIDEO_ADV_DEBUG
44 * If advanced debugging is on, then count how often each op is called
45 * successfully, which can either be per-buffer or per-queue.
47 * This makes it easy to check that the 'init' and 'cleanup'
48 * (and variations thereof) stay balanced.
51 #define log_memop(vb, op) \
52 dprintk(2, "call_memop(%p, %d, %s)%s\n", \
53 (vb)->vb2_queue, (vb)->index, #op, \
54 (vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
56 #define call_memop(vb, op, args...) \
58 struct vb2_queue *_q = (vb)->vb2_queue; \
62 err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \
64 (vb)->cnt_mem_ ## op++; \
68 #define call_ptr_memop(vb, op, args...) \
70 struct vb2_queue *_q = (vb)->vb2_queue; \
74 ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \
75 if (!IS_ERR_OR_NULL(ptr)) \
76 (vb)->cnt_mem_ ## op++; \
80 #define call_void_memop(vb, op, args...) \
82 struct vb2_queue *_q = (vb)->vb2_queue; \
85 if (_q->mem_ops->op) \
86 _q->mem_ops->op(args); \
87 (vb)->cnt_mem_ ## op++; \
90 #define log_qop(q, op) \
91 dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \
92 (q)->ops->op ? "" : " (nop)")
94 #define call_qop(q, op, args...) \
99 err = (q)->ops->op ? (q)->ops->op(args) : 0; \
105 #define call_void_qop(q, op, args...) \
109 (q)->ops->op(args); \
113 #define log_vb_qop(vb, op, args...) \
114 dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \
115 (vb)->vb2_queue, (vb)->index, #op, \
116 (vb)->vb2_queue->ops->op ? "" : " (nop)")
118 #define call_vb_qop(vb, op, args...) \
122 log_vb_qop(vb, op); \
123 err = (vb)->vb2_queue->ops->op ? \
124 (vb)->vb2_queue->ops->op(args) : 0; \
126 (vb)->cnt_ ## op++; \
130 #define call_void_vb_qop(vb, op, args...) \
132 log_vb_qop(vb, op); \
133 if ((vb)->vb2_queue->ops->op) \
134 (vb)->vb2_queue->ops->op(args); \
135 (vb)->cnt_ ## op++; \
140 #define call_memop(vb, op, args...) \
141 ((vb)->vb2_queue->mem_ops->op ? \
142 (vb)->vb2_queue->mem_ops->op(args) : 0)
144 #define call_ptr_memop(vb, op, args...) \
145 ((vb)->vb2_queue->mem_ops->op ? \
146 (vb)->vb2_queue->mem_ops->op(args) : NULL)
148 #define call_void_memop(vb, op, args...) \
150 if ((vb)->vb2_queue->mem_ops->op) \
151 (vb)->vb2_queue->mem_ops->op(args); \
154 #define call_qop(q, op, args...) \
155 ((q)->ops->op ? (q)->ops->op(args) : 0)
157 #define call_void_qop(q, op, args...) \
160 (q)->ops->op(args); \
163 #define call_vb_qop(vb, op, args...) \
164 ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
166 #define call_void_vb_qop(vb, op, args...) \
168 if ((vb)->vb2_queue->ops->op) \
169 (vb)->vb2_queue->ops->op(args); \
174 #define call_bufop(q, op, args...) \
177 if (q && q->buf_ops && q->buf_ops->op) \
178 ret = q->buf_ops->op(args); \
182 #define call_void_bufop(q, op, args...) \
184 if (q && q->buf_ops && q->buf_ops->op) \
185 q->buf_ops->op(args); \
188 static void __vb2_queue_cancel(struct vb2_queue *q);
189 static void __enqueue_in_driver(struct vb2_buffer *vb);
192 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
194 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
196 struct vb2_queue *q = vb->vb2_queue;
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,
209 q->alloc_devs[plane] ? : q->dev,
210 q->dma_attrs, size, q->dma_dir, q->gfp_flags);
211 if (IS_ERR_OR_NULL(mem_priv)) {
213 ret = PTR_ERR(mem_priv);
217 /* Associate allocator private data with this plane */
218 vb->planes[plane].mem_priv = mem_priv;
223 /* Free already allocated memory if one of the allocations failed */
224 for (; plane > 0; --plane) {
225 call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
226 vb->planes[plane - 1].mem_priv = NULL;
233 * __vb2_buf_mem_free() - free memory of the given buffer
235 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
239 for (plane = 0; plane < vb->num_planes; ++plane) {
240 call_void_memop(vb, put, vb->planes[plane].mem_priv);
241 vb->planes[plane].mem_priv = NULL;
242 dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index);
247 * __vb2_buf_userptr_put() - release userspace memory associated with
250 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
254 for (plane = 0; plane < vb->num_planes; ++plane) {
255 if (vb->planes[plane].mem_priv)
256 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
257 vb->planes[plane].mem_priv = NULL;
262 * __vb2_plane_dmabuf_put() - release memory associated with
263 * a DMABUF shared plane
265 static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
271 call_void_memop(vb, unmap_dmabuf, p->mem_priv);
273 call_void_memop(vb, detach_dmabuf, p->mem_priv);
274 dma_buf_put(p->dbuf);
281 * __vb2_buf_dmabuf_put() - release memory associated with
282 * a DMABUF shared buffer
284 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
288 for (plane = 0; plane < vb->num_planes; ++plane)
289 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
293 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
296 static void __setup_offsets(struct vb2_buffer *vb)
298 struct vb2_queue *q = vb->vb2_queue;
300 unsigned long off = 0;
303 struct vb2_buffer *prev = q->bufs[vb->index - 1];
304 struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
306 off = PAGE_ALIGN(p->m.offset + p->length);
309 for (plane = 0; plane < vb->num_planes; ++plane) {
310 vb->planes[plane].m.offset = off;
312 dprintk(3, "buffer %d, plane %d offset 0x%08lx\n",
313 vb->index, plane, off);
315 off += vb->planes[plane].length;
316 off = PAGE_ALIGN(off);
321 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
322 * video buffer memory for all buffers/planes on the queue and initializes the
325 * Returns the number of buffers successfully allocated.
327 static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
328 unsigned int num_buffers, unsigned int num_planes,
329 const unsigned plane_sizes[VB2_MAX_PLANES])
331 unsigned int buffer, plane;
332 struct vb2_buffer *vb;
335 for (buffer = 0; buffer < num_buffers; ++buffer) {
336 /* Allocate videobuf buffer structures */
337 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
339 dprintk(1, "memory alloc for buffer struct failed\n");
343 vb->state = VB2_BUF_STATE_DEQUEUED;
345 vb->num_planes = num_planes;
346 vb->index = q->num_buffers + buffer;
349 for (plane = 0; plane < num_planes; ++plane) {
350 vb->planes[plane].length = plane_sizes[plane];
351 vb->planes[plane].min_length = plane_sizes[plane];
353 q->bufs[vb->index] = vb;
355 /* Allocate video buffer memory for the MMAP type */
356 if (memory == VB2_MEMORY_MMAP) {
357 ret = __vb2_buf_mem_alloc(vb);
359 dprintk(1, "failed allocating memory for buffer %d\n",
361 q->bufs[vb->index] = NULL;
367 * Call the driver-provided buffer initialization
368 * callback, if given. An error in initialization
369 * results in queue setup failure.
371 ret = call_vb_qop(vb, buf_init, vb);
373 dprintk(1, "buffer %d %p initialization failed\n",
375 __vb2_buf_mem_free(vb);
376 q->bufs[vb->index] = NULL;
383 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
390 * __vb2_free_mem() - release all video buffer memory for a given queue
392 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
395 struct vb2_buffer *vb;
397 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
399 vb = q->bufs[buffer];
403 /* Free MMAP buffers or release USERPTR buffers */
404 if (q->memory == VB2_MEMORY_MMAP)
405 __vb2_buf_mem_free(vb);
406 else if (q->memory == VB2_MEMORY_DMABUF)
407 __vb2_buf_dmabuf_put(vb);
409 __vb2_buf_userptr_put(vb);
414 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
415 * related information, if no buffers are left return the queue to an
416 * uninitialized state. Might be called even if the queue has already been freed.
418 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
423 * Sanity check: when preparing a buffer the queue lock is released for
424 * a short while (see __buf_prepare for the details), which would allow
425 * a race with a reqbufs which can call this function. Removing the
426 * buffers from underneath __buf_prepare is obviously a bad idea, so we
427 * check if any of the buffers is in the state PREPARING, and if so we
428 * just return -EAGAIN.
430 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
432 if (q->bufs[buffer] == NULL)
434 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
435 dprintk(1, "preparing buffers, cannot free\n");
440 /* Call driver-provided cleanup function for each buffer, if provided */
441 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
443 struct vb2_buffer *vb = q->bufs[buffer];
445 if (vb && vb->planes[0].mem_priv)
446 call_void_vb_qop(vb, buf_cleanup, vb);
449 /* Release video buffer memory */
450 __vb2_free_mem(q, buffers);
452 #ifdef CONFIG_VIDEO_ADV_DEBUG
454 * Check that all the calls were balances during the life-time of this
455 * queue. If not (or if the debug level is 1 or up), then dump the
456 * counters to the kernel log.
458 if (q->num_buffers) {
459 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
460 q->cnt_wait_prepare != q->cnt_wait_finish;
462 if (unbalanced || debug) {
463 pr_info("vb2: counters for queue %p:%s\n", q,
464 unbalanced ? " UNBALANCED!" : "");
465 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
466 q->cnt_queue_setup, q->cnt_start_streaming,
467 q->cnt_stop_streaming);
468 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
469 q->cnt_wait_prepare, q->cnt_wait_finish);
471 q->cnt_queue_setup = 0;
472 q->cnt_wait_prepare = 0;
473 q->cnt_wait_finish = 0;
474 q->cnt_start_streaming = 0;
475 q->cnt_stop_streaming = 0;
477 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
478 struct vb2_buffer *vb = q->bufs[buffer];
479 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
480 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
481 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
482 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
483 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
484 vb->cnt_buf_queue != vb->cnt_buf_done ||
485 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
486 vb->cnt_buf_init != vb->cnt_buf_cleanup;
488 if (unbalanced || debug) {
489 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
490 q, buffer, unbalanced ? " UNBALANCED!" : "");
491 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
492 vb->cnt_buf_init, vb->cnt_buf_cleanup,
493 vb->cnt_buf_prepare, vb->cnt_buf_finish);
494 pr_info("vb2: buf_queue: %u buf_done: %u\n",
495 vb->cnt_buf_queue, vb->cnt_buf_done);
496 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
497 vb->cnt_mem_alloc, vb->cnt_mem_put,
498 vb->cnt_mem_prepare, vb->cnt_mem_finish,
500 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
501 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
502 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
503 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
504 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
505 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
506 vb->cnt_mem_get_dmabuf,
507 vb->cnt_mem_num_users,
514 /* Free videobuf buffers */
515 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
517 kfree(q->bufs[buffer]);
518 q->bufs[buffer] = NULL;
521 q->num_buffers -= buffers;
522 if (!q->num_buffers) {
524 INIT_LIST_HEAD(&q->queued_list);
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]))
561 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
563 call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
565 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
568 * __verify_userptr_ops() - verify that all memory operations required for
569 * USERPTR queue type have been provided
571 static int __verify_userptr_ops(struct vb2_queue *q)
573 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
574 !q->mem_ops->put_userptr)
581 * __verify_mmap_ops() - verify that all memory operations required for
582 * MMAP queue type have been provided
584 static int __verify_mmap_ops(struct vb2_queue *q)
586 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
587 !q->mem_ops->put || !q->mem_ops->mmap)
594 * __verify_dmabuf_ops() - verify that all memory operations required for
595 * DMABUF queue type have been provided
597 static int __verify_dmabuf_ops(struct vb2_queue *q)
599 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
600 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
601 !q->mem_ops->unmap_dmabuf)
607 int vb2_verify_memory_type(struct vb2_queue *q,
608 enum vb2_memory memory, unsigned int type)
610 if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
611 memory != VB2_MEMORY_DMABUF) {
612 dprintk(1, "unsupported memory type\n");
616 if (type != q->type) {
617 dprintk(1, "requested type is incorrect\n");
622 * Make sure all the required memory ops for given memory type
625 if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
626 dprintk(1, "MMAP for current setup unsupported\n");
630 if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
631 dprintk(1, "USERPTR for current setup unsupported\n");
635 if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
636 dprintk(1, "DMABUF for current setup unsupported\n");
641 * Place the busy tests at the end: -EBUSY can be ignored when
642 * create_bufs is called with count == 0, but count == 0 should still
643 * do the memory and type validation.
645 if (vb2_fileio_is_active(q)) {
646 dprintk(1, "file io in progress\n");
651 EXPORT_SYMBOL(vb2_verify_memory_type);
653 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
656 unsigned int num_buffers, allocated_buffers, num_planes = 0;
657 unsigned plane_sizes[VB2_MAX_PLANES] = { };
661 dprintk(1, "streaming active\n");
665 if (*count == 0 || q->num_buffers != 0 || q->memory != memory) {
667 * We already have buffers allocated, so first check if they
668 * are not in use and can be freed.
670 mutex_lock(&q->mmap_lock);
671 if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) {
672 mutex_unlock(&q->mmap_lock);
673 dprintk(1, "memory in use, cannot free\n");
678 * Call queue_cancel to clean up any buffers in the PREPARED or
679 * QUEUED state which is possible if buffers were prepared or
680 * queued without ever calling STREAMON.
682 __vb2_queue_cancel(q);
683 ret = __vb2_queue_free(q, q->num_buffers);
684 mutex_unlock(&q->mmap_lock);
689 * In case of REQBUFS(0) return immediately without calling
690 * driver's queue_setup() callback and allocating resources.
697 * Make sure the requested values and current defaults are sane.
699 num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME);
700 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
701 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
705 * Ask the driver how many buffers and planes per buffer it requires.
706 * Driver also sets the size and allocator context for each plane.
708 ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
709 plane_sizes, q->alloc_devs);
713 /* Finally, allocate buffers and video memory */
715 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
716 if (allocated_buffers == 0) {
717 dprintk(1, "memory allocation failed\n");
722 * There is no point in continuing if we can't allocate the minimum
723 * number of buffers needed by this vb2_queue.
725 if (allocated_buffers < q->min_buffers_needed)
729 * Check if driver can handle the allocated number of buffers.
731 if (!ret && allocated_buffers < num_buffers) {
732 num_buffers = allocated_buffers;
734 * num_planes is set by the previous queue_setup(), but since it
735 * signals to queue_setup() whether it is called from create_bufs()
736 * vs reqbufs() we zero it here to signal that queue_setup() is
737 * called for the reqbufs() case.
741 ret = call_qop(q, queue_setup, q, &num_buffers,
742 &num_planes, plane_sizes, q->alloc_devs);
744 if (!ret && allocated_buffers < num_buffers)
748 * Either the driver has accepted a smaller number of buffers,
749 * or .queue_setup() returned an error
753 mutex_lock(&q->mmap_lock);
754 q->num_buffers = allocated_buffers;
758 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
759 * from q->num_buffers.
761 __vb2_queue_free(q, allocated_buffers);
762 mutex_unlock(&q->mmap_lock);
765 mutex_unlock(&q->mmap_lock);
768 * Return the number of successfully allocated buffers
771 *count = allocated_buffers;
772 q->waiting_for_buffers = !q->is_output;
776 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
778 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
779 unsigned int *count, unsigned requested_planes,
780 const unsigned requested_sizes[])
782 unsigned int num_planes = 0, num_buffers, allocated_buffers;
783 unsigned plane_sizes[VB2_MAX_PLANES] = { };
786 if (q->num_buffers == VB2_MAX_FRAME) {
787 dprintk(1, "maximum number of buffers already allocated\n");
791 if (!q->num_buffers) {
792 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
794 q->waiting_for_buffers = !q->is_output;
797 num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
799 if (requested_planes && requested_sizes) {
800 num_planes = requested_planes;
801 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
805 * Ask the driver, whether the requested number of buffers, planes per
806 * buffer and their sizes are acceptable
808 ret = call_qop(q, queue_setup, q, &num_buffers,
809 &num_planes, plane_sizes, q->alloc_devs);
813 /* Finally, allocate buffers and video memory */
814 allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
815 num_planes, plane_sizes);
816 if (allocated_buffers == 0) {
817 dprintk(1, "memory allocation failed\n");
822 * Check if driver can handle the so far allocated number of buffers.
824 if (allocated_buffers < num_buffers) {
825 num_buffers = allocated_buffers;
828 * q->num_buffers contains the total number of buffers, that the
829 * queue driver has set up
831 ret = call_qop(q, queue_setup, q, &num_buffers,
832 &num_planes, plane_sizes, q->alloc_devs);
834 if (!ret && allocated_buffers < num_buffers)
838 * Either the driver has accepted a smaller number of buffers,
839 * or .queue_setup() returned an error
843 mutex_lock(&q->mmap_lock);
844 q->num_buffers += allocated_buffers;
848 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
849 * from q->num_buffers.
851 __vb2_queue_free(q, allocated_buffers);
852 mutex_unlock(&q->mmap_lock);
855 mutex_unlock(&q->mmap_lock);
858 * Return the number of successfully allocated buffers
861 *count = allocated_buffers;
865 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
867 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
869 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
872 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
875 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
877 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
879 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
882 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
884 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
886 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
888 struct vb2_queue *q = vb->vb2_queue;
892 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
895 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
896 state != VB2_BUF_STATE_ERROR &&
897 state != VB2_BUF_STATE_QUEUED &&
898 state != VB2_BUF_STATE_REQUEUEING))
899 state = VB2_BUF_STATE_ERROR;
901 #ifdef CONFIG_VIDEO_ADV_DEBUG
903 * Although this is not a callback, it still does have to balance
904 * with the buf_queue op. So update this counter manually.
908 dprintk(4, "done processing on buffer %d, state: %d\n",
912 for (plane = 0; plane < vb->num_planes; ++plane)
913 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
915 spin_lock_irqsave(&q->done_lock, flags);
916 if (state == VB2_BUF_STATE_QUEUED ||
917 state == VB2_BUF_STATE_REQUEUEING) {
918 vb->state = VB2_BUF_STATE_QUEUED;
920 /* Add the buffer to the done buffers list */
921 list_add_tail(&vb->done_entry, &q->done_list);
924 atomic_dec(&q->owned_by_drv_count);
925 spin_unlock_irqrestore(&q->done_lock, flags);
927 trace_vb2_buf_done(q, vb);
930 case VB2_BUF_STATE_QUEUED:
932 case VB2_BUF_STATE_REQUEUEING:
933 if (q->start_streaming_called)
934 __enqueue_in_driver(vb);
937 /* Inform any processes that may be waiting for buffers */
938 wake_up(&q->done_wq);
942 EXPORT_SYMBOL_GPL(vb2_buffer_done);
944 void vb2_discard_done(struct vb2_queue *q)
946 struct vb2_buffer *vb;
949 spin_lock_irqsave(&q->done_lock, flags);
950 list_for_each_entry(vb, &q->done_list, done_entry)
951 vb->state = VB2_BUF_STATE_ERROR;
952 spin_unlock_irqrestore(&q->done_lock, flags);
954 EXPORT_SYMBOL_GPL(vb2_discard_done);
957 * __prepare_mmap() - prepare an MMAP buffer
959 static int __prepare_mmap(struct vb2_buffer *vb, const void *pb)
964 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
966 return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
970 * __prepare_userptr() - prepare a USERPTR buffer
972 static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
974 struct vb2_plane planes[VB2_MAX_PLANES];
975 struct vb2_queue *q = vb->vb2_queue;
979 bool reacquired = vb->planes[0].mem_priv == NULL;
981 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
982 /* Copy relevant information provided by the userspace */
984 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
990 for (plane = 0; plane < vb->num_planes; ++plane) {
991 /* Skip the plane if already verified */
992 if (vb->planes[plane].m.userptr &&
993 vb->planes[plane].m.userptr == planes[plane].m.userptr
994 && vb->planes[plane].length == planes[plane].length)
997 dprintk(3, "userspace address for plane %d changed, reacquiring memory\n",
1000 /* Check if the provided plane buffer is large enough */
1001 if (planes[plane].length < vb->planes[plane].min_length) {
1002 dprintk(1, "provided buffer size %u is less than setup size %u for plane %d\n",
1003 planes[plane].length,
1004 vb->planes[plane].min_length,
1010 /* Release previously acquired memory if present */
1011 if (vb->planes[plane].mem_priv) {
1014 call_void_vb_qop(vb, buf_cleanup, vb);
1016 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1019 vb->planes[plane].mem_priv = NULL;
1020 vb->planes[plane].bytesused = 0;
1021 vb->planes[plane].length = 0;
1022 vb->planes[plane].m.userptr = 0;
1023 vb->planes[plane].data_offset = 0;
1025 /* Acquire each plane's memory */
1026 mem_priv = call_ptr_memop(vb, get_userptr,
1027 q->alloc_devs[plane] ? : q->dev,
1028 planes[plane].m.userptr,
1029 planes[plane].length, q->dma_dir);
1030 if (IS_ERR(mem_priv)) {
1031 dprintk(1, "failed acquiring userspace memory for plane %d\n",
1033 ret = PTR_ERR(mem_priv);
1036 vb->planes[plane].mem_priv = mem_priv;
1040 * Now that everything is in order, copy relevant information
1041 * provided by userspace.
1043 for (plane = 0; plane < vb->num_planes; ++plane) {
1044 vb->planes[plane].bytesused = planes[plane].bytesused;
1045 vb->planes[plane].length = planes[plane].length;
1046 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1047 vb->planes[plane].data_offset = planes[plane].data_offset;
1052 * One or more planes changed, so we must call buf_init to do
1053 * the driver-specific initialization on the newly acquired
1054 * buffer, if provided.
1056 ret = call_vb_qop(vb, buf_init, vb);
1058 dprintk(1, "buffer initialization failed\n");
1063 ret = call_vb_qop(vb, buf_prepare, vb);
1065 dprintk(1, "buffer preparation failed\n");
1066 call_void_vb_qop(vb, buf_cleanup, vb);
1072 /* In case of errors, release planes that were already acquired */
1073 for (plane = 0; plane < vb->num_planes; ++plane) {
1074 if (vb->planes[plane].mem_priv)
1075 call_void_memop(vb, put_userptr,
1076 vb->planes[plane].mem_priv);
1077 vb->planes[plane].mem_priv = NULL;
1078 vb->planes[plane].m.userptr = 0;
1079 vb->planes[plane].length = 0;
1086 * __prepare_dmabuf() - prepare a DMABUF buffer
1088 static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
1090 struct vb2_plane planes[VB2_MAX_PLANES];
1091 struct vb2_queue *q = vb->vb2_queue;
1095 bool reacquired = vb->planes[0].mem_priv == NULL;
1097 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1098 /* Copy relevant information provided by the userspace */
1100 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1106 for (plane = 0; plane < vb->num_planes; ++plane) {
1107 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1109 if (IS_ERR_OR_NULL(dbuf)) {
1110 dprintk(1, "invalid dmabuf fd for plane %d\n",
1116 /* use DMABUF size if length is not provided */
1117 if (planes[plane].length == 0)
1118 planes[plane].length = dbuf->size;
1120 if (planes[plane].length < vb->planes[plane].min_length) {
1121 dprintk(1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1122 planes[plane].length, plane,
1123 vb->planes[plane].min_length);
1129 /* Skip the plane if already verified */
1130 if (dbuf == vb->planes[plane].dbuf &&
1131 vb->planes[plane].length == planes[plane].length) {
1136 dprintk(3, "buffer for plane %d changed\n", plane);
1140 call_void_vb_qop(vb, buf_cleanup, vb);
1143 /* Release previously acquired memory if present */
1144 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1145 vb->planes[plane].bytesused = 0;
1146 vb->planes[plane].length = 0;
1147 vb->planes[plane].m.fd = 0;
1148 vb->planes[plane].data_offset = 0;
1150 /* Acquire each plane's memory */
1151 mem_priv = call_ptr_memop(vb, attach_dmabuf,
1152 q->alloc_devs[plane] ? : q->dev,
1153 dbuf, planes[plane].length, q->dma_dir);
1154 if (IS_ERR(mem_priv)) {
1155 dprintk(1, "failed to attach dmabuf\n");
1156 ret = PTR_ERR(mem_priv);
1161 vb->planes[plane].dbuf = dbuf;
1162 vb->planes[plane].mem_priv = mem_priv;
1166 * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1167 * here instead just before the DMA, while queueing the buffer(s) so
1168 * userspace knows sooner rather than later if the dma-buf map fails.
1170 for (plane = 0; plane < vb->num_planes; ++plane) {
1171 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1173 dprintk(1, "failed to map dmabuf for plane %d\n",
1177 vb->planes[plane].dbuf_mapped = 1;
1181 * Now that everything is in order, copy relevant information
1182 * provided by userspace.
1184 for (plane = 0; plane < vb->num_planes; ++plane) {
1185 vb->planes[plane].bytesused = planes[plane].bytesused;
1186 vb->planes[plane].length = planes[plane].length;
1187 vb->planes[plane].m.fd = planes[plane].m.fd;
1188 vb->planes[plane].data_offset = planes[plane].data_offset;
1193 * Call driver-specific initialization on the newly acquired buffer,
1196 ret = call_vb_qop(vb, buf_init, vb);
1198 dprintk(1, "buffer initialization failed\n");
1203 ret = call_vb_qop(vb, buf_prepare, vb);
1205 dprintk(1, "buffer preparation failed\n");
1206 call_void_vb_qop(vb, buf_cleanup, vb);
1212 /* In case of errors, release planes that were already acquired */
1213 __vb2_buf_dmabuf_put(vb);
1219 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1221 static void __enqueue_in_driver(struct vb2_buffer *vb)
1223 struct vb2_queue *q = vb->vb2_queue;
1225 vb->state = VB2_BUF_STATE_ACTIVE;
1226 atomic_inc(&q->owned_by_drv_count);
1228 trace_vb2_buf_queue(q, vb);
1230 call_void_vb_qop(vb, buf_queue, vb);
1233 static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
1235 struct vb2_queue *q = vb->vb2_queue;
1240 dprintk(1, "fatal error occurred on queue\n");
1244 vb->state = VB2_BUF_STATE_PREPARING;
1246 switch (q->memory) {
1247 case VB2_MEMORY_MMAP:
1248 ret = __prepare_mmap(vb, pb);
1250 case VB2_MEMORY_USERPTR:
1251 ret = __prepare_userptr(vb, pb);
1253 case VB2_MEMORY_DMABUF:
1254 ret = __prepare_dmabuf(vb, pb);
1257 WARN(1, "Invalid queue type\n");
1262 dprintk(1, "buffer preparation failed: %d\n", ret);
1263 vb->state = VB2_BUF_STATE_DEQUEUED;
1268 for (plane = 0; plane < vb->num_planes; ++plane)
1269 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1271 vb->state = VB2_BUF_STATE_PREPARED;
1276 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1278 struct vb2_buffer *vb;
1281 vb = q->bufs[index];
1282 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1283 dprintk(1, "invalid buffer state %d\n",
1288 ret = __buf_prepare(vb, pb);
1292 /* Fill buffer information for the userspace */
1293 call_void_bufop(q, fill_user_buffer, vb, pb);
1295 dprintk(2, "prepare of buffer %d succeeded\n", vb->index);
1299 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1302 * vb2_start_streaming() - Attempt to start streaming.
1303 * @q: videobuf2 queue
1305 * Attempt to start streaming. When this function is called there must be
1306 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1307 * number of buffers required for the DMA engine to function). If the
1308 * @start_streaming op fails it is supposed to return all the driver-owned
1309 * buffers back to vb2 in state QUEUED. Check if that happened and if
1310 * not warn and reclaim them forcefully.
1312 static int vb2_start_streaming(struct vb2_queue *q)
1314 struct vb2_buffer *vb;
1318 * If any buffers were queued before streamon,
1319 * we can now pass them to driver for processing.
1321 list_for_each_entry(vb, &q->queued_list, queued_entry)
1322 __enqueue_in_driver(vb);
1324 /* Tell the driver to start streaming */
1325 q->start_streaming_called = 1;
1326 ret = call_qop(q, start_streaming, q,
1327 atomic_read(&q->owned_by_drv_count));
1331 q->start_streaming_called = 0;
1333 dprintk(1, "driver refused to start streaming\n");
1335 * If you see this warning, then the driver isn't cleaning up properly
1336 * after a failed start_streaming(). See the start_streaming()
1337 * documentation in videobuf2-core.h for more information how buffers
1338 * should be returned to vb2 in start_streaming().
1340 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1344 * Forcefully reclaim buffers if the driver did not
1345 * correctly return them to vb2.
1347 for (i = 0; i < q->num_buffers; ++i) {
1349 if (vb->state == VB2_BUF_STATE_ACTIVE)
1350 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1352 /* Must be zero now */
1353 WARN_ON(atomic_read(&q->owned_by_drv_count));
1356 * If done_list is not empty, then start_streaming() didn't call
1357 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1360 WARN_ON(!list_empty(&q->done_list));
1364 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
1366 struct vb2_buffer *vb;
1369 vb = q->bufs[index];
1371 switch (vb->state) {
1372 case VB2_BUF_STATE_DEQUEUED:
1373 ret = __buf_prepare(vb, pb);
1377 case VB2_BUF_STATE_PREPARED:
1379 case VB2_BUF_STATE_PREPARING:
1380 dprintk(1, "buffer still being prepared\n");
1383 dprintk(1, "invalid buffer state %d\n", vb->state);
1388 * Add to the queued buffers list, a buffer will stay on it until
1389 * dequeued in dqbuf.
1391 list_add_tail(&vb->queued_entry, &q->queued_list);
1393 q->waiting_for_buffers = false;
1394 vb->state = VB2_BUF_STATE_QUEUED;
1397 call_void_bufop(q, copy_timestamp, vb, pb);
1399 trace_vb2_qbuf(q, vb);
1402 * If already streaming, give the buffer to driver for processing.
1403 * If not, the buffer will be given to driver on next streamon.
1405 if (q->start_streaming_called)
1406 __enqueue_in_driver(vb);
1408 /* Fill buffer information for the userspace */
1410 call_void_bufop(q, fill_user_buffer, vb, pb);
1413 * If streamon has been called, and we haven't yet called
1414 * start_streaming() since not enough buffers were queued, and
1415 * we now have reached the minimum number of queued buffers,
1416 * then we can finally call start_streaming().
1418 if (q->streaming && !q->start_streaming_called &&
1419 q->queued_count >= q->min_buffers_needed) {
1420 ret = vb2_start_streaming(q);
1425 dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
1428 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1431 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1434 * Will sleep if required for nonblocking == false.
1436 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1439 * All operations on vb_done_list are performed under done_lock
1440 * spinlock protection. However, buffers may be removed from
1441 * it and returned to userspace only while holding both driver's
1442 * lock and the done_lock spinlock. Thus we can be sure that as
1443 * long as we hold the driver's lock, the list will remain not
1444 * empty if list_empty() check succeeds.
1450 if (!q->streaming) {
1451 dprintk(1, "streaming off, will not wait for buffers\n");
1456 dprintk(1, "Queue in error state, will not wait for buffers\n");
1460 if (q->last_buffer_dequeued) {
1461 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1465 if (!list_empty(&q->done_list)) {
1467 * Found a buffer that we were waiting for.
1473 dprintk(3, "nonblocking and no buffers to dequeue, will not wait\n");
1478 * We are streaming and blocking, wait for another buffer to
1479 * become ready or for streamoff. Driver's lock is released to
1480 * allow streamoff or qbuf to be called while waiting.
1482 call_void_qop(q, wait_prepare, q);
1485 * All locks have been released, it is safe to sleep now.
1487 dprintk(3, "will sleep waiting for buffers\n");
1488 ret = wait_event_interruptible(q->done_wq,
1489 !list_empty(&q->done_list) || !q->streaming ||
1493 * We need to reevaluate both conditions again after reacquiring
1494 * the locks or return an error if one occurred.
1496 call_void_qop(q, wait_finish, q);
1498 dprintk(1, "sleep was interrupted\n");
1506 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1508 * Will sleep if required for nonblocking == false.
1510 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1511 void *pb, int nonblocking)
1513 unsigned long flags;
1517 * Wait for at least one buffer to become available on the done_list.
1519 ret = __vb2_wait_for_done_vb(q, nonblocking);
1524 * Driver's lock has been held since we last verified that done_list
1525 * is not empty, so no need for another list_empty(done_list) check.
1527 spin_lock_irqsave(&q->done_lock, flags);
1528 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1530 * Only remove the buffer from done_list if all planes can be
1531 * handled. Some cases such as V4L2 file I/O and DVB have pb
1532 * == NULL; skip the check then as there's nothing to verify.
1535 ret = call_bufop(q, verify_planes_array, *vb, pb);
1537 list_del(&(*vb)->done_entry);
1538 spin_unlock_irqrestore(&q->done_lock, flags);
1543 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1545 if (!q->streaming) {
1546 dprintk(1, "streaming off, will not wait for buffers\n");
1550 if (q->start_streaming_called)
1551 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1554 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1557 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1559 static void __vb2_dqbuf(struct vb2_buffer *vb)
1561 struct vb2_queue *q = vb->vb2_queue;
1564 /* nothing to do if the buffer is already dequeued */
1565 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1568 vb->state = VB2_BUF_STATE_DEQUEUED;
1570 /* unmap DMABUF buffer */
1571 if (q->memory == VB2_MEMORY_DMABUF)
1572 for (i = 0; i < vb->num_planes; ++i) {
1573 if (!vb->planes[i].dbuf_mapped)
1575 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1576 vb->planes[i].dbuf_mapped = 0;
1580 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1583 struct vb2_buffer *vb = NULL;
1586 ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1590 switch (vb->state) {
1591 case VB2_BUF_STATE_DONE:
1592 dprintk(3, "returning done buffer\n");
1594 case VB2_BUF_STATE_ERROR:
1595 dprintk(3, "returning done buffer with errors\n");
1598 dprintk(1, "invalid buffer state\n");
1602 call_void_vb_qop(vb, buf_finish, vb);
1605 *pindex = vb->index;
1607 /* Fill buffer information for the userspace */
1609 call_void_bufop(q, fill_user_buffer, vb, pb);
1611 /* Remove from videobuf queue */
1612 list_del(&vb->queued_entry);
1615 trace_vb2_dqbuf(q, vb);
1617 /* go back to dequeued state */
1620 dprintk(2, "dqbuf of buffer %d, with state %d\n",
1621 vb->index, vb->state);
1626 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1629 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1631 * Removes all queued buffers from driver's queue and all buffers queued by
1632 * userspace from videobuf's queue. Returns to state after reqbufs.
1634 static void __vb2_queue_cancel(struct vb2_queue *q)
1639 * Tell driver to stop all transactions and release all queued
1642 if (q->start_streaming_called)
1643 call_void_qop(q, stop_streaming, q);
1646 * If you see this warning, then the driver isn't cleaning up properly
1647 * in stop_streaming(). See the stop_streaming() documentation in
1648 * videobuf2-core.h for more information how buffers should be returned
1649 * to vb2 in stop_streaming().
1651 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1652 for (i = 0; i < q->num_buffers; ++i)
1653 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
1654 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1655 /* Must be zero now */
1656 WARN_ON(atomic_read(&q->owned_by_drv_count));
1660 q->start_streaming_called = 0;
1661 q->queued_count = 0;
1665 * Remove all buffers from videobuf's list...
1667 INIT_LIST_HEAD(&q->queued_list);
1669 * ...and done list; userspace will not receive any buffers it
1670 * has not already dequeued before initiating cancel.
1672 INIT_LIST_HEAD(&q->done_list);
1673 atomic_set(&q->owned_by_drv_count, 0);
1674 wake_up_all(&q->done_wq);
1677 * Reinitialize all buffers for next use.
1678 * Make sure to call buf_finish for any queued buffers. Normally
1679 * that's done in dqbuf, but that's not going to happen when we
1680 * cancel the whole queue. Note: this code belongs here, not in
1681 * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1682 * call to __fill_user_buffer() after buf_finish(). That order can't
1683 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1685 for (i = 0; i < q->num_buffers; ++i) {
1686 struct vb2_buffer *vb = q->bufs[i];
1688 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1689 vb->state = VB2_BUF_STATE_PREPARED;
1690 call_void_vb_qop(vb, buf_finish, vb);
1696 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1700 if (type != q->type) {
1701 dprintk(1, "invalid stream type\n");
1706 dprintk(3, "already streaming\n");
1710 if (!q->num_buffers) {
1711 dprintk(1, "no buffers have been allocated\n");
1715 if (q->num_buffers < q->min_buffers_needed) {
1716 dprintk(1, "need at least %u allocated buffers\n",
1717 q->min_buffers_needed);
1722 * Tell driver to start streaming provided sufficient buffers
1725 if (q->queued_count >= q->min_buffers_needed) {
1726 ret = v4l_vb2q_enable_media_source(q);
1729 ret = vb2_start_streaming(q);
1731 __vb2_queue_cancel(q);
1738 dprintk(3, "successful\n");
1741 EXPORT_SYMBOL_GPL(vb2_core_streamon);
1743 void vb2_queue_error(struct vb2_queue *q)
1747 wake_up_all(&q->done_wq);
1749 EXPORT_SYMBOL_GPL(vb2_queue_error);
1751 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
1753 if (type != q->type) {
1754 dprintk(1, "invalid stream type\n");
1759 * Cancel will pause streaming and remove all buffers from the driver
1760 * and videobuf, effectively returning control over them to userspace.
1762 * Note that we do this even if q->streaming == 0: if you prepare or
1763 * queue buffers, and then call streamoff without ever having called
1764 * streamon, you would still expect those buffers to be returned to
1765 * their normal dequeued state.
1767 __vb2_queue_cancel(q);
1768 q->waiting_for_buffers = !q->is_output;
1769 q->last_buffer_dequeued = false;
1771 dprintk(3, "successful\n");
1774 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
1777 * __find_plane_by_offset() - find plane associated with the given offset off
1779 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1780 unsigned int *_buffer, unsigned int *_plane)
1782 struct vb2_buffer *vb;
1783 unsigned int buffer, plane;
1786 * Go over all buffers and their planes, comparing the given offset
1787 * with an offset assigned to each plane. If a match is found,
1788 * return its buffer and plane numbers.
1790 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1791 vb = q->bufs[buffer];
1793 for (plane = 0; plane < vb->num_planes; ++plane) {
1794 if (vb->planes[plane].m.offset == off) {
1805 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
1806 unsigned int index, unsigned int plane, unsigned int flags)
1808 struct vb2_buffer *vb = NULL;
1809 struct vb2_plane *vb_plane;
1811 struct dma_buf *dbuf;
1813 if (q->memory != VB2_MEMORY_MMAP) {
1814 dprintk(1, "queue is not currently set up for mmap\n");
1818 if (!q->mem_ops->get_dmabuf) {
1819 dprintk(1, "queue does not support DMA buffer exporting\n");
1823 if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
1824 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
1828 if (type != q->type) {
1829 dprintk(1, "invalid buffer type\n");
1833 if (index >= q->num_buffers) {
1834 dprintk(1, "buffer index out of range\n");
1838 vb = q->bufs[index];
1840 if (plane >= vb->num_planes) {
1841 dprintk(1, "buffer plane out of range\n");
1845 if (vb2_fileio_is_active(q)) {
1846 dprintk(1, "expbuf: file io in progress\n");
1850 vb_plane = &vb->planes[plane];
1852 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
1854 if (IS_ERR_OR_NULL(dbuf)) {
1855 dprintk(1, "failed to export buffer %d, plane %d\n",
1860 ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
1862 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1868 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1874 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
1876 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1878 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1879 struct vb2_buffer *vb;
1880 unsigned int buffer = 0, plane = 0;
1882 unsigned long length;
1884 if (q->memory != VB2_MEMORY_MMAP) {
1885 dprintk(1, "queue is not currently set up for mmap\n");
1890 * Check memory area access mode.
1892 if (!(vma->vm_flags & VM_SHARED)) {
1893 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
1897 if (!(vma->vm_flags & VM_WRITE)) {
1898 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
1902 if (!(vma->vm_flags & VM_READ)) {
1903 dprintk(1, "invalid vma flags, VM_READ needed\n");
1907 if (vb2_fileio_is_active(q)) {
1908 dprintk(1, "mmap: file io in progress\n");
1913 * Find the plane corresponding to the offset passed by userspace.
1915 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1919 vb = q->bufs[buffer];
1922 * MMAP requires page_aligned buffers.
1923 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1924 * so, we need to do the same here.
1926 length = PAGE_ALIGN(vb->planes[plane].length);
1927 if (length < (vma->vm_end - vma->vm_start)) {
1929 "MMAP invalid, as it would overflow buffer length\n");
1933 mutex_lock(&q->mmap_lock);
1934 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
1935 mutex_unlock(&q->mmap_lock);
1939 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
1942 EXPORT_SYMBOL_GPL(vb2_mmap);
1945 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1948 unsigned long pgoff,
1949 unsigned long flags)
1951 unsigned long off = pgoff << PAGE_SHIFT;
1952 struct vb2_buffer *vb;
1953 unsigned int buffer, plane;
1957 if (q->memory != VB2_MEMORY_MMAP) {
1958 dprintk(1, "queue is not currently set up for mmap\n");
1963 * Find the plane corresponding to the offset passed by userspace.
1965 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1969 vb = q->bufs[buffer];
1971 vaddr = vb2_plane_vaddr(vb, plane);
1972 return vaddr ? (unsigned long)vaddr : -EINVAL;
1974 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
1977 int vb2_core_queue_init(struct vb2_queue *q)
1984 WARN_ON(!q->mem_ops) ||
1985 WARN_ON(!q->type) ||
1986 WARN_ON(!q->io_modes) ||
1987 WARN_ON(!q->ops->queue_setup) ||
1988 WARN_ON(!q->ops->buf_queue))
1991 INIT_LIST_HEAD(&q->queued_list);
1992 INIT_LIST_HEAD(&q->done_list);
1993 spin_lock_init(&q->done_lock);
1994 mutex_init(&q->mmap_lock);
1995 init_waitqueue_head(&q->done_wq);
1997 if (q->buf_struct_size == 0)
1998 q->buf_struct_size = sizeof(struct vb2_buffer);
2000 if (q->bidirectional)
2001 q->dma_dir = DMA_BIDIRECTIONAL;
2003 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2007 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2009 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2010 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2011 void vb2_core_queue_release(struct vb2_queue *q)
2013 __vb2_cleanup_fileio(q);
2014 __vb2_queue_cancel(q);
2015 mutex_lock(&q->mmap_lock);
2016 __vb2_queue_free(q, q->num_buffers);
2017 mutex_unlock(&q->mmap_lock);
2019 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2021 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
2024 __poll_t req_events = poll_requested_events(wait);
2025 struct vb2_buffer *vb = NULL;
2026 unsigned long flags;
2028 if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
2030 if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
2034 * Start file I/O emulator only if streaming API has not been used yet.
2036 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2037 if (!q->is_output && (q->io_modes & VB2_READ) &&
2038 (req_events & (POLLIN | POLLRDNORM))) {
2039 if (__vb2_init_fileio(q, 1))
2042 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2043 (req_events & (POLLOUT | POLLWRNORM))) {
2044 if (__vb2_init_fileio(q, 0))
2047 * Write to OUTPUT queue can be done immediately.
2049 return POLLOUT | POLLWRNORM;
2054 * There is nothing to wait for if the queue isn't streaming, or if the
2055 * error flag is set.
2057 if (!vb2_is_streaming(q) || q->error)
2061 * If this quirk is set and QBUF hasn't been called yet then
2062 * return POLLERR as well. This only affects capture queues, output
2063 * queues will always initialize waiting_for_buffers to false.
2064 * This quirk is set by V4L2 for backwards compatibility reasons.
2066 if (q->quirk_poll_must_check_waiting_for_buffers &&
2067 q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
2071 * For output streams you can call write() as long as there are fewer
2072 * buffers queued than there are buffers available.
2074 if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2075 return POLLOUT | POLLWRNORM;
2077 if (list_empty(&q->done_list)) {
2079 * If the last buffer was dequeued from a capture queue,
2080 * return immediately. DQBUF will return -EPIPE.
2082 if (q->last_buffer_dequeued)
2083 return POLLIN | POLLRDNORM;
2085 poll_wait(file, &q->done_wq, wait);
2089 * Take first buffer available for dequeuing.
2091 spin_lock_irqsave(&q->done_lock, flags);
2092 if (!list_empty(&q->done_list))
2093 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2095 spin_unlock_irqrestore(&q->done_lock, flags);
2097 if (vb && (vb->state == VB2_BUF_STATE_DONE
2098 || vb->state == VB2_BUF_STATE_ERROR)) {
2099 return (q->is_output) ?
2100 POLLOUT | POLLWRNORM :
2101 POLLIN | POLLRDNORM;
2105 EXPORT_SYMBOL_GPL(vb2_core_poll);
2108 * struct vb2_fileio_buf - buffer context used by file io emulator
2110 * vb2 provides a compatibility layer and emulator of file io (read and
2111 * write) calls on top of streaming API. This structure is used for
2112 * tracking context related to the buffers.
2114 struct vb2_fileio_buf {
2118 unsigned int queued:1;
2122 * struct vb2_fileio_data - queue context used by file io emulator
2124 * @cur_index: the index of the buffer currently being read from or
2125 * written to. If equal to q->num_buffers then a new buffer
2127 * @initial_index: in the read() case all buffers are queued up immediately
2128 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2129 * buffers. However, in the write() case no buffers are initially
2130 * queued, instead whenever a buffer is full it is queued up by
2131 * __vb2_perform_fileio(). Only once all available buffers have
2132 * been queued up will __vb2_perform_fileio() start to dequeue
2133 * buffers. This means that initially __vb2_perform_fileio()
2134 * needs to know what buffer index to use when it is queuing up
2135 * the buffers for the first time. That initial index is stored
2136 * in this field. Once it is equal to q->num_buffers all
2137 * available buffers have been queued and __vb2_perform_fileio()
2138 * should start the normal dequeue/queue cycle.
2140 * vb2 provides a compatibility layer and emulator of file io (read and
2141 * write) calls on top of streaming API. For proper operation it required
2142 * this structure to save the driver state between each call of the read
2143 * or write function.
2145 struct vb2_fileio_data {
2148 unsigned int memory;
2149 struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2150 unsigned int cur_index;
2151 unsigned int initial_index;
2152 unsigned int q_count;
2153 unsigned int dq_count;
2154 unsigned read_once:1;
2155 unsigned write_immediately:1;
2159 * __vb2_init_fileio() - initialize file io emulator
2160 * @q: videobuf2 queue
2161 * @read: mode selector (1 means read, 0 means write)
2163 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2165 struct vb2_fileio_data *fileio;
2167 unsigned int count = 0;
2172 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2173 (!read && !(q->io_modes & VB2_WRITE))))
2177 * Check if device supports mapping buffers to kernel virtual space.
2179 if (!q->mem_ops->vaddr)
2183 * Check if streaming api has not been already activated.
2185 if (q->streaming || q->num_buffers > 0)
2189 * Start with count 1, driver can increase it in queue_setup()
2193 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2194 (read) ? "read" : "write", count, q->fileio_read_once,
2195 q->fileio_write_immediately);
2197 fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2201 fileio->read_once = q->fileio_read_once;
2202 fileio->write_immediately = q->fileio_write_immediately;
2205 * Request buffers and use MMAP type to force driver
2206 * to allocate buffers by itself.
2208 fileio->count = count;
2209 fileio->memory = VB2_MEMORY_MMAP;
2210 fileio->type = q->type;
2212 ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2217 * Check if plane_count is correct
2218 * (multiplane buffers are not supported).
2220 if (q->bufs[0]->num_planes != 1) {
2226 * Get kernel address of each buffer.
2228 for (i = 0; i < q->num_buffers; i++) {
2229 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2230 if (fileio->bufs[i].vaddr == NULL) {
2234 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2238 * Read mode requires pre queuing of all buffers.
2242 * Queue all buffers.
2244 for (i = 0; i < q->num_buffers; i++) {
2245 ret = vb2_core_qbuf(q, i, NULL);
2248 fileio->bufs[i].queued = 1;
2251 * All buffers have been queued, so mark that by setting
2252 * initial_index to q->num_buffers
2254 fileio->initial_index = q->num_buffers;
2255 fileio->cur_index = q->num_buffers;
2261 ret = vb2_core_streamon(q, q->type);
2269 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2278 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2279 * @q: videobuf2 queue
2281 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2283 struct vb2_fileio_data *fileio = q->fileio;
2286 vb2_core_streamoff(q, q->type);
2289 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2291 dprintk(3, "file io emulator closed\n");
2297 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2298 * @q: videobuf2 queue
2299 * @data: pointed to target userspace buffer
2300 * @count: number of bytes to read or write
2301 * @ppos: file handle position tracking pointer
2302 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2303 * @read: access mode selector (1 means read, 0 means write)
2305 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2306 loff_t *ppos, int nonblock, int read)
2308 struct vb2_fileio_data *fileio;
2309 struct vb2_fileio_buf *buf;
2310 bool is_multiplanar = q->is_multiplanar;
2312 * When using write() to write data to an output video node the vb2 core
2313 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2314 * else is able to provide this information with the write() operation.
2316 bool copy_timestamp = !read && q->copy_timestamp;
2320 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2321 read ? "read" : "write", (long)*ppos, count,
2322 nonblock ? "non" : "");
2328 * Initialize emulator on first call.
2330 if (!vb2_fileio_is_active(q)) {
2331 ret = __vb2_init_fileio(q, read);
2332 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2339 * Check if we need to dequeue the buffer.
2341 index = fileio->cur_index;
2342 if (index >= q->num_buffers) {
2343 struct vb2_buffer *b;
2346 * Call vb2_dqbuf to get buffer back.
2348 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2349 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2352 fileio->dq_count += 1;
2354 fileio->cur_index = index;
2355 buf = &fileio->bufs[index];
2359 * Get number of bytes filled by the driver
2363 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2364 : vb2_plane_size(q->bufs[index], 0);
2365 /* Compensate for data_offset on read in the multiplanar case. */
2366 if (is_multiplanar && read &&
2367 b->planes[0].data_offset < buf->size) {
2368 buf->pos = b->planes[0].data_offset;
2369 buf->size -= buf->pos;
2372 buf = &fileio->bufs[index];
2376 * Limit count on last few bytes of the buffer.
2378 if (buf->pos + count > buf->size) {
2379 count = buf->size - buf->pos;
2380 dprintk(5, "reducing read count: %zd\n", count);
2384 * Transfer data to userspace.
2386 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2387 count, index, buf->pos);
2389 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2391 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2393 dprintk(3, "error copying data\n");
2404 * Queue next buffer if required.
2406 if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2407 struct vb2_buffer *b = q->bufs[index];
2410 * Check if this is the last buffer to read.
2412 if (read && fileio->read_once && fileio->dq_count == 1) {
2413 dprintk(3, "read limit reached\n");
2414 return __vb2_cleanup_fileio(q);
2418 * Call vb2_qbuf and give buffer to the driver.
2420 b->planes[0].bytesused = buf->pos;
2423 b->timestamp = ktime_get_ns();
2424 ret = vb2_core_qbuf(q, index, NULL);
2425 dprintk(5, "vb2_dbuf result: %d\n", ret);
2430 * Buffer has been queued, update the status
2434 buf->size = vb2_plane_size(q->bufs[index], 0);
2435 fileio->q_count += 1;
2437 * If we are queuing up buffers for the first time, then
2438 * increase initial_index by one.
2440 if (fileio->initial_index < q->num_buffers)
2441 fileio->initial_index++;
2443 * The next buffer to use is either a buffer that's going to be
2444 * queued for the first time (initial_index < q->num_buffers)
2445 * or it is equal to q->num_buffers, meaning that the next
2446 * time we need to dequeue a buffer since we've now queued up
2447 * all the 'first time' buffers.
2449 fileio->cur_index = fileio->initial_index;
2453 * Return proper number of bytes processed.
2460 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2461 loff_t *ppos, int nonblocking)
2463 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2465 EXPORT_SYMBOL_GPL(vb2_read);
2467 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2468 loff_t *ppos, int nonblocking)
2470 return __vb2_perform_fileio(q, (char __user *) data, count,
2471 ppos, nonblocking, 0);
2473 EXPORT_SYMBOL_GPL(vb2_write);
2475 struct vb2_threadio_data {
2476 struct task_struct *thread;
2482 static int vb2_thread(void *data)
2484 struct vb2_queue *q = data;
2485 struct vb2_threadio_data *threadio = q->threadio;
2486 bool copy_timestamp = false;
2487 unsigned prequeue = 0;
2492 prequeue = q->num_buffers;
2493 copy_timestamp = q->copy_timestamp;
2499 struct vb2_buffer *vb;
2502 * Call vb2_dqbuf to get buffer back.
2505 vb = q->bufs[index++];
2508 call_void_qop(q, wait_finish, q);
2509 if (!threadio->stop)
2510 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2511 call_void_qop(q, wait_prepare, q);
2512 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2514 vb = q->bufs[index];
2516 if (ret || threadio->stop)
2520 if (vb->state != VB2_BUF_STATE_ERROR)
2521 if (threadio->fnc(vb, threadio->priv))
2523 call_void_qop(q, wait_finish, q);
2525 vb->timestamp = ktime_get_ns();;
2526 if (!threadio->stop)
2527 ret = vb2_core_qbuf(q, vb->index, NULL);
2528 call_void_qop(q, wait_prepare, q);
2529 if (ret || threadio->stop)
2533 /* Hmm, linux becomes *very* unhappy without this ... */
2534 while (!kthread_should_stop()) {
2535 set_current_state(TASK_INTERRUPTIBLE);
2542 * This function should not be used for anything else but the videobuf2-dvb
2543 * support. If you think you have another good use-case for this, then please
2544 * contact the linux-media mailinglist first.
2546 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2547 const char *thread_name)
2549 struct vb2_threadio_data *threadio;
2556 if (WARN_ON(q->fileio))
2559 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2560 if (threadio == NULL)
2562 threadio->fnc = fnc;
2563 threadio->priv = priv;
2565 ret = __vb2_init_fileio(q, !q->is_output);
2566 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2569 q->threadio = threadio;
2570 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2571 if (IS_ERR(threadio->thread)) {
2572 ret = PTR_ERR(threadio->thread);
2573 threadio->thread = NULL;
2579 __vb2_cleanup_fileio(q);
2584 EXPORT_SYMBOL_GPL(vb2_thread_start);
2586 int vb2_thread_stop(struct vb2_queue *q)
2588 struct vb2_threadio_data *threadio = q->threadio;
2591 if (threadio == NULL)
2593 threadio->stop = true;
2594 /* Wake up all pending sleeps in the thread */
2596 err = kthread_stop(threadio->thread);
2597 __vb2_cleanup_fileio(q);
2598 threadio->thread = NULL;
2603 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2605 MODULE_DESCRIPTION("Media buffer core framework");
2606 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2607 MODULE_LICENSE("GPL");