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 /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
336 num_buffers = min_t(unsigned int, num_buffers,
337 VB2_MAX_FRAME - q->num_buffers);
339 for (buffer = 0; buffer < num_buffers; ++buffer) {
340 /* Allocate videobuf buffer structures */
341 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
343 dprintk(1, "memory alloc for buffer struct failed\n");
347 vb->state = VB2_BUF_STATE_DEQUEUED;
349 vb->num_planes = num_planes;
350 vb->index = q->num_buffers + buffer;
353 for (plane = 0; plane < num_planes; ++plane) {
354 vb->planes[plane].length = plane_sizes[plane];
355 vb->planes[plane].min_length = plane_sizes[plane];
357 q->bufs[vb->index] = vb;
359 /* Allocate video buffer memory for the MMAP type */
360 if (memory == VB2_MEMORY_MMAP) {
361 ret = __vb2_buf_mem_alloc(vb);
363 dprintk(1, "failed allocating memory for buffer %d\n",
365 q->bufs[vb->index] = NULL;
371 * Call the driver-provided buffer initialization
372 * callback, if given. An error in initialization
373 * results in queue setup failure.
375 ret = call_vb_qop(vb, buf_init, vb);
377 dprintk(1, "buffer %d %p initialization failed\n",
379 __vb2_buf_mem_free(vb);
380 q->bufs[vb->index] = NULL;
387 dprintk(1, "allocated %d buffers, %d plane(s) each\n",
394 * __vb2_free_mem() - release all video buffer memory for a given queue
396 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
399 struct vb2_buffer *vb;
401 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
403 vb = q->bufs[buffer];
407 /* Free MMAP buffers or release USERPTR buffers */
408 if (q->memory == VB2_MEMORY_MMAP)
409 __vb2_buf_mem_free(vb);
410 else if (q->memory == VB2_MEMORY_DMABUF)
411 __vb2_buf_dmabuf_put(vb);
413 __vb2_buf_userptr_put(vb);
418 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
419 * related information, if no buffers are left return the queue to an
420 * uninitialized state. Might be called even if the queue has already been freed.
422 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
427 * Sanity check: when preparing a buffer the queue lock is released for
428 * a short while (see __buf_prepare for the details), which would allow
429 * a race with a reqbufs which can call this function. Removing the
430 * buffers from underneath __buf_prepare is obviously a bad idea, so we
431 * check if any of the buffers is in the state PREPARING, and if so we
432 * just return -EAGAIN.
434 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
436 if (q->bufs[buffer] == NULL)
438 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
439 dprintk(1, "preparing buffers, cannot free\n");
444 /* Call driver-provided cleanup function for each buffer, if provided */
445 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
447 struct vb2_buffer *vb = q->bufs[buffer];
449 if (vb && vb->planes[0].mem_priv)
450 call_void_vb_qop(vb, buf_cleanup, vb);
453 /* Release video buffer memory */
454 __vb2_free_mem(q, buffers);
456 #ifdef CONFIG_VIDEO_ADV_DEBUG
458 * Check that all the calls were balances during the life-time of this
459 * queue. If not (or if the debug level is 1 or up), then dump the
460 * counters to the kernel log.
462 if (q->num_buffers) {
463 bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
464 q->cnt_wait_prepare != q->cnt_wait_finish;
466 if (unbalanced || debug) {
467 pr_info("vb2: counters for queue %p:%s\n", q,
468 unbalanced ? " UNBALANCED!" : "");
469 pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n",
470 q->cnt_queue_setup, q->cnt_start_streaming,
471 q->cnt_stop_streaming);
472 pr_info("vb2: wait_prepare: %u wait_finish: %u\n",
473 q->cnt_wait_prepare, q->cnt_wait_finish);
475 q->cnt_queue_setup = 0;
476 q->cnt_wait_prepare = 0;
477 q->cnt_wait_finish = 0;
478 q->cnt_start_streaming = 0;
479 q->cnt_stop_streaming = 0;
481 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
482 struct vb2_buffer *vb = q->bufs[buffer];
483 bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
484 vb->cnt_mem_prepare != vb->cnt_mem_finish ||
485 vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
486 vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
487 vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
488 vb->cnt_buf_queue != vb->cnt_buf_done ||
489 vb->cnt_buf_prepare != vb->cnt_buf_finish ||
490 vb->cnt_buf_init != vb->cnt_buf_cleanup;
492 if (unbalanced || debug) {
493 pr_info("vb2: counters for queue %p, buffer %d:%s\n",
494 q, buffer, unbalanced ? " UNBALANCED!" : "");
495 pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
496 vb->cnt_buf_init, vb->cnt_buf_cleanup,
497 vb->cnt_buf_prepare, vb->cnt_buf_finish);
498 pr_info("vb2: buf_queue: %u buf_done: %u\n",
499 vb->cnt_buf_queue, vb->cnt_buf_done);
500 pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
501 vb->cnt_mem_alloc, vb->cnt_mem_put,
502 vb->cnt_mem_prepare, vb->cnt_mem_finish,
504 pr_info("vb2: get_userptr: %u put_userptr: %u\n",
505 vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
506 pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
507 vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
508 vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
509 pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
510 vb->cnt_mem_get_dmabuf,
511 vb->cnt_mem_num_users,
518 /* Free videobuf buffers */
519 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
521 kfree(q->bufs[buffer]);
522 q->bufs[buffer] = NULL;
525 q->num_buffers -= buffers;
526 if (!q->num_buffers) {
528 INIT_LIST_HEAD(&q->queued_list);
533 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
536 for (plane = 0; plane < vb->num_planes; ++plane) {
537 void *mem_priv = vb->planes[plane].mem_priv;
539 * If num_users() has not been provided, call_memop
540 * will return 0, apparently nobody cares about this
541 * case anyway. If num_users() returns more than 1,
542 * we are not the only user of the plane's memory.
544 if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
549 EXPORT_SYMBOL(vb2_buffer_in_use);
552 * __buffers_in_use() - return true if any buffers on the queue are in use and
553 * the queue cannot be freed (by the means of REQBUFS(0)) call
555 static bool __buffers_in_use(struct vb2_queue *q)
558 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
559 if (vb2_buffer_in_use(q, q->bufs[buffer]))
565 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
567 call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
569 EXPORT_SYMBOL_GPL(vb2_core_querybuf);
572 * __verify_userptr_ops() - verify that all memory operations required for
573 * USERPTR queue type have been provided
575 static int __verify_userptr_ops(struct vb2_queue *q)
577 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
578 !q->mem_ops->put_userptr)
585 * __verify_mmap_ops() - verify that all memory operations required for
586 * MMAP queue type have been provided
588 static int __verify_mmap_ops(struct vb2_queue *q)
590 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
591 !q->mem_ops->put || !q->mem_ops->mmap)
598 * __verify_dmabuf_ops() - verify that all memory operations required for
599 * DMABUF queue type have been provided
601 static int __verify_dmabuf_ops(struct vb2_queue *q)
603 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
604 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
605 !q->mem_ops->unmap_dmabuf)
611 int vb2_verify_memory_type(struct vb2_queue *q,
612 enum vb2_memory memory, unsigned int type)
614 if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
615 memory != VB2_MEMORY_DMABUF) {
616 dprintk(1, "unsupported memory type\n");
620 if (type != q->type) {
621 dprintk(1, "requested type is incorrect\n");
626 * Make sure all the required memory ops for given memory type
629 if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
630 dprintk(1, "MMAP for current setup unsupported\n");
634 if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
635 dprintk(1, "USERPTR for current setup unsupported\n");
639 if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
640 dprintk(1, "DMABUF for current setup unsupported\n");
645 * Place the busy tests at the end: -EBUSY can be ignored when
646 * create_bufs is called with count == 0, but count == 0 should still
647 * do the memory and type validation.
649 if (vb2_fileio_is_active(q)) {
650 dprintk(1, "file io in progress\n");
655 EXPORT_SYMBOL(vb2_verify_memory_type);
657 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
660 unsigned int num_buffers, allocated_buffers, num_planes = 0;
661 unsigned plane_sizes[VB2_MAX_PLANES] = { };
665 dprintk(1, "streaming active\n");
669 if (*count == 0 || q->num_buffers != 0 || q->memory != memory) {
671 * We already have buffers allocated, so first check if they
672 * are not in use and can be freed.
674 mutex_lock(&q->mmap_lock);
675 if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) {
676 mutex_unlock(&q->mmap_lock);
677 dprintk(1, "memory in use, cannot free\n");
682 * Call queue_cancel to clean up any buffers in the PREPARED or
683 * QUEUED state which is possible if buffers were prepared or
684 * queued without ever calling STREAMON.
686 __vb2_queue_cancel(q);
687 ret = __vb2_queue_free(q, q->num_buffers);
688 mutex_unlock(&q->mmap_lock);
693 * In case of REQBUFS(0) return immediately without calling
694 * driver's queue_setup() callback and allocating resources.
701 * Make sure the requested values and current defaults are sane.
703 num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME);
704 num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed);
705 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
709 * Ask the driver how many buffers and planes per buffer it requires.
710 * Driver also sets the size and allocator context for each plane.
712 ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
713 plane_sizes, q->alloc_devs);
717 /* Finally, allocate buffers and video memory */
719 __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
720 if (allocated_buffers == 0) {
721 dprintk(1, "memory allocation failed\n");
726 * There is no point in continuing if we can't allocate the minimum
727 * number of buffers needed by this vb2_queue.
729 if (allocated_buffers < q->min_buffers_needed)
733 * Check if driver can handle the allocated number of buffers.
735 if (!ret && allocated_buffers < num_buffers) {
736 num_buffers = allocated_buffers;
738 * num_planes is set by the previous queue_setup(), but since it
739 * signals to queue_setup() whether it is called from create_bufs()
740 * vs reqbufs() we zero it here to signal that queue_setup() is
741 * called for the reqbufs() case.
745 ret = call_qop(q, queue_setup, q, &num_buffers,
746 &num_planes, plane_sizes, q->alloc_devs);
748 if (!ret && allocated_buffers < num_buffers)
752 * Either the driver has accepted a smaller number of buffers,
753 * or .queue_setup() returned an error
757 mutex_lock(&q->mmap_lock);
758 q->num_buffers = allocated_buffers;
762 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
763 * from q->num_buffers.
765 __vb2_queue_free(q, allocated_buffers);
766 mutex_unlock(&q->mmap_lock);
769 mutex_unlock(&q->mmap_lock);
772 * Return the number of successfully allocated buffers
775 *count = allocated_buffers;
776 q->waiting_for_buffers = !q->is_output;
780 EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
782 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
783 unsigned int *count, unsigned requested_planes,
784 const unsigned requested_sizes[])
786 unsigned int num_planes = 0, num_buffers, allocated_buffers;
787 unsigned plane_sizes[VB2_MAX_PLANES] = { };
790 if (q->num_buffers == VB2_MAX_FRAME) {
791 dprintk(1, "maximum number of buffers already allocated\n");
795 if (!q->num_buffers) {
796 memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
798 q->waiting_for_buffers = !q->is_output;
801 num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
803 if (requested_planes && requested_sizes) {
804 num_planes = requested_planes;
805 memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
809 * Ask the driver, whether the requested number of buffers, planes per
810 * buffer and their sizes are acceptable
812 ret = call_qop(q, queue_setup, q, &num_buffers,
813 &num_planes, plane_sizes, q->alloc_devs);
817 /* Finally, allocate buffers and video memory */
818 allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
819 num_planes, plane_sizes);
820 if (allocated_buffers == 0) {
821 dprintk(1, "memory allocation failed\n");
826 * Check if driver can handle the so far allocated number of buffers.
828 if (allocated_buffers < num_buffers) {
829 num_buffers = allocated_buffers;
832 * q->num_buffers contains the total number of buffers, that the
833 * queue driver has set up
835 ret = call_qop(q, queue_setup, q, &num_buffers,
836 &num_planes, plane_sizes, q->alloc_devs);
838 if (!ret && allocated_buffers < num_buffers)
842 * Either the driver has accepted a smaller number of buffers,
843 * or .queue_setup() returned an error
847 mutex_lock(&q->mmap_lock);
848 q->num_buffers += allocated_buffers;
852 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
853 * from q->num_buffers.
855 __vb2_queue_free(q, allocated_buffers);
856 mutex_unlock(&q->mmap_lock);
859 mutex_unlock(&q->mmap_lock);
862 * Return the number of successfully allocated buffers
865 *count = allocated_buffers;
869 EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
871 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
873 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
876 return call_ptr_memop(vb, vaddr, vb->planes[plane_no].mem_priv);
879 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
881 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
883 if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
886 return call_ptr_memop(vb, cookie, vb->planes[plane_no].mem_priv);
888 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
890 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
892 struct vb2_queue *q = vb->vb2_queue;
896 if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
899 if (WARN_ON(state != VB2_BUF_STATE_DONE &&
900 state != VB2_BUF_STATE_ERROR &&
901 state != VB2_BUF_STATE_QUEUED &&
902 state != VB2_BUF_STATE_REQUEUEING))
903 state = VB2_BUF_STATE_ERROR;
905 #ifdef CONFIG_VIDEO_ADV_DEBUG
907 * Although this is not a callback, it still does have to balance
908 * with the buf_queue op. So update this counter manually.
912 dprintk(4, "done processing on buffer %d, state: %d\n",
915 if (state != VB2_BUF_STATE_QUEUED &&
916 state != VB2_BUF_STATE_REQUEUEING) {
918 for (plane = 0; plane < vb->num_planes; ++plane)
919 call_void_memop(vb, finish, vb->planes[plane].mem_priv);
922 spin_lock_irqsave(&q->done_lock, flags);
923 if (state == VB2_BUF_STATE_QUEUED ||
924 state == VB2_BUF_STATE_REQUEUEING) {
925 vb->state = VB2_BUF_STATE_QUEUED;
927 /* Add the buffer to the done buffers list */
928 list_add_tail(&vb->done_entry, &q->done_list);
931 atomic_dec(&q->owned_by_drv_count);
932 spin_unlock_irqrestore(&q->done_lock, flags);
934 trace_vb2_buf_done(q, vb);
937 case VB2_BUF_STATE_QUEUED:
939 case VB2_BUF_STATE_REQUEUEING:
940 if (q->start_streaming_called)
941 __enqueue_in_driver(vb);
944 /* Inform any processes that may be waiting for buffers */
945 wake_up(&q->done_wq);
949 EXPORT_SYMBOL_GPL(vb2_buffer_done);
951 void vb2_discard_done(struct vb2_queue *q)
953 struct vb2_buffer *vb;
956 spin_lock_irqsave(&q->done_lock, flags);
957 list_for_each_entry(vb, &q->done_list, done_entry)
958 vb->state = VB2_BUF_STATE_ERROR;
959 spin_unlock_irqrestore(&q->done_lock, flags);
961 EXPORT_SYMBOL_GPL(vb2_discard_done);
964 * __prepare_mmap() - prepare an MMAP buffer
966 static int __prepare_mmap(struct vb2_buffer *vb, const void *pb)
971 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
973 return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
977 * __prepare_userptr() - prepare a USERPTR buffer
979 static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
981 struct vb2_plane planes[VB2_MAX_PLANES];
982 struct vb2_queue *q = vb->vb2_queue;
986 bool reacquired = vb->planes[0].mem_priv == NULL;
988 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
989 /* Copy relevant information provided by the userspace */
991 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
997 for (plane = 0; plane < vb->num_planes; ++plane) {
998 /* Skip the plane if already verified */
999 if (vb->planes[plane].m.userptr &&
1000 vb->planes[plane].m.userptr == planes[plane].m.userptr
1001 && vb->planes[plane].length == planes[plane].length)
1004 dprintk(3, "userspace address for plane %d changed, reacquiring memory\n",
1007 /* Check if the provided plane buffer is large enough */
1008 if (planes[plane].length < vb->planes[plane].min_length) {
1009 dprintk(1, "provided buffer size %u is less than setup size %u for plane %d\n",
1010 planes[plane].length,
1011 vb->planes[plane].min_length,
1017 /* Release previously acquired memory if present */
1018 if (vb->planes[plane].mem_priv) {
1021 call_void_vb_qop(vb, buf_cleanup, vb);
1023 call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
1026 vb->planes[plane].mem_priv = NULL;
1027 vb->planes[plane].bytesused = 0;
1028 vb->planes[plane].length = 0;
1029 vb->planes[plane].m.userptr = 0;
1030 vb->planes[plane].data_offset = 0;
1032 /* Acquire each plane's memory */
1033 mem_priv = call_ptr_memop(vb, get_userptr,
1034 q->alloc_devs[plane] ? : q->dev,
1035 planes[plane].m.userptr,
1036 planes[plane].length, q->dma_dir);
1037 if (IS_ERR(mem_priv)) {
1038 dprintk(1, "failed acquiring userspace memory for plane %d\n",
1040 ret = PTR_ERR(mem_priv);
1043 vb->planes[plane].mem_priv = mem_priv;
1047 * Now that everything is in order, copy relevant information
1048 * provided by userspace.
1050 for (plane = 0; plane < vb->num_planes; ++plane) {
1051 vb->planes[plane].bytesused = planes[plane].bytesused;
1052 vb->planes[plane].length = planes[plane].length;
1053 vb->planes[plane].m.userptr = planes[plane].m.userptr;
1054 vb->planes[plane].data_offset = planes[plane].data_offset;
1059 * One or more planes changed, so we must call buf_init to do
1060 * the driver-specific initialization on the newly acquired
1061 * buffer, if provided.
1063 ret = call_vb_qop(vb, buf_init, vb);
1065 dprintk(1, "buffer initialization failed\n");
1070 ret = call_vb_qop(vb, buf_prepare, vb);
1072 dprintk(1, "buffer preparation failed\n");
1073 call_void_vb_qop(vb, buf_cleanup, vb);
1079 /* In case of errors, release planes that were already acquired */
1080 for (plane = 0; plane < vb->num_planes; ++plane) {
1081 if (vb->planes[plane].mem_priv)
1082 call_void_memop(vb, put_userptr,
1083 vb->planes[plane].mem_priv);
1084 vb->planes[plane].mem_priv = NULL;
1085 vb->planes[plane].m.userptr = 0;
1086 vb->planes[plane].length = 0;
1093 * __prepare_dmabuf() - prepare a DMABUF buffer
1095 static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
1097 struct vb2_plane planes[VB2_MAX_PLANES];
1098 struct vb2_queue *q = vb->vb2_queue;
1102 bool reacquired = vb->planes[0].mem_priv == NULL;
1104 memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
1105 /* Copy relevant information provided by the userspace */
1107 ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
1113 for (plane = 0; plane < vb->num_planes; ++plane) {
1114 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1116 if (IS_ERR_OR_NULL(dbuf)) {
1117 dprintk(1, "invalid dmabuf fd for plane %d\n",
1123 /* use DMABUF size if length is not provided */
1124 if (planes[plane].length == 0)
1125 planes[plane].length = dbuf->size;
1127 if (planes[plane].length < vb->planes[plane].min_length) {
1128 dprintk(1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
1129 planes[plane].length, plane,
1130 vb->planes[plane].min_length);
1136 /* Skip the plane if already verified */
1137 if (dbuf == vb->planes[plane].dbuf &&
1138 vb->planes[plane].length == planes[plane].length) {
1143 dprintk(3, "buffer for plane %d changed\n", plane);
1147 call_void_vb_qop(vb, buf_cleanup, vb);
1150 /* Release previously acquired memory if present */
1151 __vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
1152 vb->planes[plane].bytesused = 0;
1153 vb->planes[plane].length = 0;
1154 vb->planes[plane].m.fd = 0;
1155 vb->planes[plane].data_offset = 0;
1157 /* Acquire each plane's memory */
1158 mem_priv = call_ptr_memop(vb, attach_dmabuf,
1159 q->alloc_devs[plane] ? : q->dev,
1160 dbuf, planes[plane].length, q->dma_dir);
1161 if (IS_ERR(mem_priv)) {
1162 dprintk(1, "failed to attach dmabuf\n");
1163 ret = PTR_ERR(mem_priv);
1168 vb->planes[plane].dbuf = dbuf;
1169 vb->planes[plane].mem_priv = mem_priv;
1173 * This pins the buffer(s) with dma_buf_map_attachment()). It's done
1174 * here instead just before the DMA, while queueing the buffer(s) so
1175 * userspace knows sooner rather than later if the dma-buf map fails.
1177 for (plane = 0; plane < vb->num_planes; ++plane) {
1178 ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
1180 dprintk(1, "failed to map dmabuf for plane %d\n",
1184 vb->planes[plane].dbuf_mapped = 1;
1188 * Now that everything is in order, copy relevant information
1189 * provided by userspace.
1191 for (plane = 0; plane < vb->num_planes; ++plane) {
1192 vb->planes[plane].bytesused = planes[plane].bytesused;
1193 vb->planes[plane].length = planes[plane].length;
1194 vb->planes[plane].m.fd = planes[plane].m.fd;
1195 vb->planes[plane].data_offset = planes[plane].data_offset;
1200 * Call driver-specific initialization on the newly acquired buffer,
1203 ret = call_vb_qop(vb, buf_init, vb);
1205 dprintk(1, "buffer initialization failed\n");
1210 ret = call_vb_qop(vb, buf_prepare, vb);
1212 dprintk(1, "buffer preparation failed\n");
1213 call_void_vb_qop(vb, buf_cleanup, vb);
1219 /* In case of errors, release planes that were already acquired */
1220 __vb2_buf_dmabuf_put(vb);
1226 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1228 static void __enqueue_in_driver(struct vb2_buffer *vb)
1230 struct vb2_queue *q = vb->vb2_queue;
1232 vb->state = VB2_BUF_STATE_ACTIVE;
1233 atomic_inc(&q->owned_by_drv_count);
1235 trace_vb2_buf_queue(q, vb);
1237 call_void_vb_qop(vb, buf_queue, vb);
1240 static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
1242 struct vb2_queue *q = vb->vb2_queue;
1247 dprintk(1, "fatal error occurred on queue\n");
1251 vb->state = VB2_BUF_STATE_PREPARING;
1253 switch (q->memory) {
1254 case VB2_MEMORY_MMAP:
1255 ret = __prepare_mmap(vb, pb);
1257 case VB2_MEMORY_USERPTR:
1258 ret = __prepare_userptr(vb, pb);
1260 case VB2_MEMORY_DMABUF:
1261 ret = __prepare_dmabuf(vb, pb);
1264 WARN(1, "Invalid queue type\n");
1269 dprintk(1, "buffer preparation failed: %d\n", ret);
1270 vb->state = VB2_BUF_STATE_DEQUEUED;
1275 for (plane = 0; plane < vb->num_planes; ++plane)
1276 call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
1278 vb->state = VB2_BUF_STATE_PREPARED;
1283 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
1285 struct vb2_buffer *vb;
1288 vb = q->bufs[index];
1289 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1290 dprintk(1, "invalid buffer state %d\n",
1295 ret = __buf_prepare(vb, pb);
1299 /* Fill buffer information for the userspace */
1300 call_void_bufop(q, fill_user_buffer, vb, pb);
1302 dprintk(2, "prepare of buffer %d succeeded\n", vb->index);
1306 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
1309 * vb2_start_streaming() - Attempt to start streaming.
1310 * @q: videobuf2 queue
1312 * Attempt to start streaming. When this function is called there must be
1313 * at least q->min_buffers_needed buffers queued up (i.e. the minimum
1314 * number of buffers required for the DMA engine to function). If the
1315 * @start_streaming op fails it is supposed to return all the driver-owned
1316 * buffers back to vb2 in state QUEUED. Check if that happened and if
1317 * not warn and reclaim them forcefully.
1319 static int vb2_start_streaming(struct vb2_queue *q)
1321 struct vb2_buffer *vb;
1325 * If any buffers were queued before streamon,
1326 * we can now pass them to driver for processing.
1328 list_for_each_entry(vb, &q->queued_list, queued_entry)
1329 __enqueue_in_driver(vb);
1331 /* Tell the driver to start streaming */
1332 q->start_streaming_called = 1;
1333 ret = call_qop(q, start_streaming, q,
1334 atomic_read(&q->owned_by_drv_count));
1338 q->start_streaming_called = 0;
1340 dprintk(1, "driver refused to start streaming\n");
1342 * If you see this warning, then the driver isn't cleaning up properly
1343 * after a failed start_streaming(). See the start_streaming()
1344 * documentation in videobuf2-core.h for more information how buffers
1345 * should be returned to vb2 in start_streaming().
1347 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1351 * Forcefully reclaim buffers if the driver did not
1352 * correctly return them to vb2.
1354 for (i = 0; i < q->num_buffers; ++i) {
1356 if (vb->state == VB2_BUF_STATE_ACTIVE)
1357 vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
1359 /* Must be zero now */
1360 WARN_ON(atomic_read(&q->owned_by_drv_count));
1363 * If done_list is not empty, then start_streaming() didn't call
1364 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
1367 WARN_ON(!list_empty(&q->done_list));
1371 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
1373 struct vb2_buffer *vb;
1374 enum vb2_buffer_state orig_state;
1378 dprintk(1, "fatal error occurred on queue\n");
1382 vb = q->bufs[index];
1384 switch (vb->state) {
1385 case VB2_BUF_STATE_DEQUEUED:
1386 ret = __buf_prepare(vb, pb);
1390 case VB2_BUF_STATE_PREPARED:
1392 case VB2_BUF_STATE_PREPARING:
1393 dprintk(1, "buffer still being prepared\n");
1396 dprintk(1, "invalid buffer state %d\n", vb->state);
1401 * Add to the queued buffers list, a buffer will stay on it until
1402 * dequeued in dqbuf.
1404 orig_state = vb->state;
1405 list_add_tail(&vb->queued_entry, &q->queued_list);
1407 q->waiting_for_buffers = false;
1408 vb->state = VB2_BUF_STATE_QUEUED;
1411 call_void_bufop(q, copy_timestamp, vb, pb);
1413 trace_vb2_qbuf(q, vb);
1416 * If already streaming, give the buffer to driver for processing.
1417 * If not, the buffer will be given to driver on next streamon.
1419 if (q->start_streaming_called)
1420 __enqueue_in_driver(vb);
1422 /* Fill buffer information for the userspace */
1424 call_void_bufop(q, fill_user_buffer, vb, pb);
1427 * If streamon has been called, and we haven't yet called
1428 * start_streaming() since not enough buffers were queued, and
1429 * we now have reached the minimum number of queued buffers,
1430 * then we can finally call start_streaming().
1432 if (q->streaming && !q->start_streaming_called &&
1433 q->queued_count >= q->min_buffers_needed) {
1434 ret = vb2_start_streaming(q);
1437 * Since vb2_core_qbuf will return with an error,
1438 * we should return it to state DEQUEUED since
1439 * the error indicates that the buffer wasn't queued.
1441 list_del(&vb->queued_entry);
1443 vb->state = orig_state;
1448 dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
1451 EXPORT_SYMBOL_GPL(vb2_core_qbuf);
1454 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1457 * Will sleep if required for nonblocking == false.
1459 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1462 * All operations on vb_done_list are performed under done_lock
1463 * spinlock protection. However, buffers may be removed from
1464 * it and returned to userspace only while holding both driver's
1465 * lock and the done_lock spinlock. Thus we can be sure that as
1466 * long as we hold the driver's lock, the list will remain not
1467 * empty if list_empty() check succeeds.
1473 if (!q->streaming) {
1474 dprintk(1, "streaming off, will not wait for buffers\n");
1479 dprintk(1, "Queue in error state, will not wait for buffers\n");
1483 if (q->last_buffer_dequeued) {
1484 dprintk(3, "last buffer dequeued already, will not wait for buffers\n");
1488 if (!list_empty(&q->done_list)) {
1490 * Found a buffer that we were waiting for.
1496 dprintk(3, "nonblocking and no buffers to dequeue, will not wait\n");
1501 * We are streaming and blocking, wait for another buffer to
1502 * become ready or for streamoff. Driver's lock is released to
1503 * allow streamoff or qbuf to be called while waiting.
1505 call_void_qop(q, wait_prepare, q);
1508 * All locks have been released, it is safe to sleep now.
1510 dprintk(3, "will sleep waiting for buffers\n");
1511 ret = wait_event_interruptible(q->done_wq,
1512 !list_empty(&q->done_list) || !q->streaming ||
1516 * We need to reevaluate both conditions again after reacquiring
1517 * the locks or return an error if one occurred.
1519 call_void_qop(q, wait_finish, q);
1521 dprintk(1, "sleep was interrupted\n");
1529 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1531 * Will sleep if required for nonblocking == false.
1533 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1534 void *pb, int nonblocking)
1536 unsigned long flags;
1540 * Wait for at least one buffer to become available on the done_list.
1542 ret = __vb2_wait_for_done_vb(q, nonblocking);
1547 * Driver's lock has been held since we last verified that done_list
1548 * is not empty, so no need for another list_empty(done_list) check.
1550 spin_lock_irqsave(&q->done_lock, flags);
1551 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1553 * Only remove the buffer from done_list if all planes can be
1554 * handled. Some cases such as V4L2 file I/O and DVB have pb
1555 * == NULL; skip the check then as there's nothing to verify.
1558 ret = call_bufop(q, verify_planes_array, *vb, pb);
1560 list_del(&(*vb)->done_entry);
1561 spin_unlock_irqrestore(&q->done_lock, flags);
1566 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1568 if (!q->streaming) {
1569 dprintk(1, "streaming off, will not wait for buffers\n");
1573 if (q->start_streaming_called)
1574 wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
1577 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1580 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1582 static void __vb2_dqbuf(struct vb2_buffer *vb)
1584 struct vb2_queue *q = vb->vb2_queue;
1587 /* nothing to do if the buffer is already dequeued */
1588 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1591 vb->state = VB2_BUF_STATE_DEQUEUED;
1593 /* unmap DMABUF buffer */
1594 if (q->memory == VB2_MEMORY_DMABUF)
1595 for (i = 0; i < vb->num_planes; ++i) {
1596 if (!vb->planes[i].dbuf_mapped)
1598 call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
1599 vb->planes[i].dbuf_mapped = 0;
1603 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
1606 struct vb2_buffer *vb = NULL;
1609 ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
1613 switch (vb->state) {
1614 case VB2_BUF_STATE_DONE:
1615 dprintk(3, "returning done buffer\n");
1617 case VB2_BUF_STATE_ERROR:
1618 dprintk(3, "returning done buffer with errors\n");
1621 dprintk(1, "invalid buffer state\n");
1625 call_void_vb_qop(vb, buf_finish, vb);
1628 *pindex = vb->index;
1630 /* Fill buffer information for the userspace */
1632 call_void_bufop(q, fill_user_buffer, vb, pb);
1634 /* Remove from videobuf queue */
1635 list_del(&vb->queued_entry);
1638 trace_vb2_dqbuf(q, vb);
1640 /* go back to dequeued state */
1643 dprintk(2, "dqbuf of buffer %d, with state %d\n",
1644 vb->index, vb->state);
1649 EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
1652 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1654 * Removes all queued buffers from driver's queue and all buffers queued by
1655 * userspace from videobuf's queue. Returns to state after reqbufs.
1657 static void __vb2_queue_cancel(struct vb2_queue *q)
1662 * Tell driver to stop all transactions and release all queued
1665 if (q->start_streaming_called)
1666 call_void_qop(q, stop_streaming, q);
1669 * If you see this warning, then the driver isn't cleaning up properly
1670 * in stop_streaming(). See the stop_streaming() documentation in
1671 * videobuf2-core.h for more information how buffers should be returned
1672 * to vb2 in stop_streaming().
1674 if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
1675 for (i = 0; i < q->num_buffers; ++i)
1676 if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE)
1677 vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
1678 /* Must be zero now */
1679 WARN_ON(atomic_read(&q->owned_by_drv_count));
1683 q->start_streaming_called = 0;
1684 q->queued_count = 0;
1688 * Remove all buffers from videobuf's list...
1690 INIT_LIST_HEAD(&q->queued_list);
1692 * ...and done list; userspace will not receive any buffers it
1693 * has not already dequeued before initiating cancel.
1695 INIT_LIST_HEAD(&q->done_list);
1696 atomic_set(&q->owned_by_drv_count, 0);
1697 wake_up_all(&q->done_wq);
1700 * Reinitialize all buffers for next use.
1701 * Make sure to call buf_finish for any queued buffers. Normally
1702 * that's done in dqbuf, but that's not going to happen when we
1703 * cancel the whole queue. Note: this code belongs here, not in
1704 * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
1705 * call to __fill_user_buffer() after buf_finish(). That order can't
1706 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
1708 for (i = 0; i < q->num_buffers; ++i) {
1709 struct vb2_buffer *vb = q->bufs[i];
1711 if (vb->state == VB2_BUF_STATE_PREPARED ||
1712 vb->state == VB2_BUF_STATE_QUEUED) {
1715 for (plane = 0; plane < vb->num_planes; ++plane)
1716 call_void_memop(vb, finish,
1717 vb->planes[plane].mem_priv);
1720 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1721 vb->state = VB2_BUF_STATE_PREPARED;
1722 call_void_vb_qop(vb, buf_finish, vb);
1728 int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
1732 if (type != q->type) {
1733 dprintk(1, "invalid stream type\n");
1738 dprintk(3, "already streaming\n");
1742 if (!q->num_buffers) {
1743 dprintk(1, "no buffers have been allocated\n");
1747 if (q->num_buffers < q->min_buffers_needed) {
1748 dprintk(1, "need at least %u allocated buffers\n",
1749 q->min_buffers_needed);
1754 * Tell driver to start streaming provided sufficient buffers
1757 if (q->queued_count >= q->min_buffers_needed) {
1758 ret = v4l_vb2q_enable_media_source(q);
1761 ret = vb2_start_streaming(q);
1763 __vb2_queue_cancel(q);
1770 dprintk(3, "successful\n");
1773 EXPORT_SYMBOL_GPL(vb2_core_streamon);
1775 void vb2_queue_error(struct vb2_queue *q)
1779 wake_up_all(&q->done_wq);
1781 EXPORT_SYMBOL_GPL(vb2_queue_error);
1783 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
1785 if (type != q->type) {
1786 dprintk(1, "invalid stream type\n");
1791 * Cancel will pause streaming and remove all buffers from the driver
1792 * and videobuf, effectively returning control over them to userspace.
1794 * Note that we do this even if q->streaming == 0: if you prepare or
1795 * queue buffers, and then call streamoff without ever having called
1796 * streamon, you would still expect those buffers to be returned to
1797 * their normal dequeued state.
1799 __vb2_queue_cancel(q);
1800 q->waiting_for_buffers = !q->is_output;
1801 q->last_buffer_dequeued = false;
1803 dprintk(3, "successful\n");
1806 EXPORT_SYMBOL_GPL(vb2_core_streamoff);
1809 * __find_plane_by_offset() - find plane associated with the given offset off
1811 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1812 unsigned int *_buffer, unsigned int *_plane)
1814 struct vb2_buffer *vb;
1815 unsigned int buffer, plane;
1818 * Go over all buffers and their planes, comparing the given offset
1819 * with an offset assigned to each plane. If a match is found,
1820 * return its buffer and plane numbers.
1822 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1823 vb = q->bufs[buffer];
1825 for (plane = 0; plane < vb->num_planes; ++plane) {
1826 if (vb->planes[plane].m.offset == off) {
1837 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
1838 unsigned int index, unsigned int plane, unsigned int flags)
1840 struct vb2_buffer *vb = NULL;
1841 struct vb2_plane *vb_plane;
1843 struct dma_buf *dbuf;
1845 if (q->memory != VB2_MEMORY_MMAP) {
1846 dprintk(1, "queue is not currently set up for mmap\n");
1850 if (!q->mem_ops->get_dmabuf) {
1851 dprintk(1, "queue does not support DMA buffer exporting\n");
1855 if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
1856 dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n");
1860 if (type != q->type) {
1861 dprintk(1, "invalid buffer type\n");
1865 if (index >= q->num_buffers) {
1866 dprintk(1, "buffer index out of range\n");
1870 vb = q->bufs[index];
1872 if (plane >= vb->num_planes) {
1873 dprintk(1, "buffer plane out of range\n");
1877 if (vb2_fileio_is_active(q)) {
1878 dprintk(1, "expbuf: file io in progress\n");
1882 vb_plane = &vb->planes[plane];
1884 dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv,
1886 if (IS_ERR_OR_NULL(dbuf)) {
1887 dprintk(1, "failed to export buffer %d, plane %d\n",
1892 ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
1894 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1900 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1906 EXPORT_SYMBOL_GPL(vb2_core_expbuf);
1908 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1910 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1911 struct vb2_buffer *vb;
1912 unsigned int buffer = 0, plane = 0;
1914 unsigned long length;
1916 if (q->memory != VB2_MEMORY_MMAP) {
1917 dprintk(1, "queue is not currently set up for mmap\n");
1922 * Check memory area access mode.
1924 if (!(vma->vm_flags & VM_SHARED)) {
1925 dprintk(1, "invalid vma flags, VM_SHARED needed\n");
1929 if (!(vma->vm_flags & VM_WRITE)) {
1930 dprintk(1, "invalid vma flags, VM_WRITE needed\n");
1934 if (!(vma->vm_flags & VM_READ)) {
1935 dprintk(1, "invalid vma flags, VM_READ needed\n");
1940 mutex_lock(&q->mmap_lock);
1942 if (vb2_fileio_is_active(q)) {
1943 dprintk(1, "mmap: file io in progress\n");
1949 * Find the plane corresponding to the offset passed by userspace.
1951 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1955 vb = q->bufs[buffer];
1958 * MMAP requires page_aligned buffers.
1959 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1960 * so, we need to do the same here.
1962 length = PAGE_ALIGN(vb->planes[plane].length);
1963 if (length < (vma->vm_end - vma->vm_start)) {
1965 "MMAP invalid, as it would overflow buffer length\n");
1970 ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
1973 mutex_unlock(&q->mmap_lock);
1977 dprintk(3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
1980 EXPORT_SYMBOL_GPL(vb2_mmap);
1983 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1986 unsigned long pgoff,
1987 unsigned long flags)
1989 unsigned long off = pgoff << PAGE_SHIFT;
1990 struct vb2_buffer *vb;
1991 unsigned int buffer, plane;
1995 if (q->memory != VB2_MEMORY_MMAP) {
1996 dprintk(1, "queue is not currently set up for mmap\n");
2001 * Find the plane corresponding to the offset passed by userspace.
2003 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2007 vb = q->bufs[buffer];
2009 vaddr = vb2_plane_vaddr(vb, plane);
2010 return vaddr ? (unsigned long)vaddr : -EINVAL;
2012 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2015 int vb2_core_queue_init(struct vb2_queue *q)
2022 WARN_ON(!q->mem_ops) ||
2023 WARN_ON(!q->type) ||
2024 WARN_ON(!q->io_modes) ||
2025 WARN_ON(!q->ops->queue_setup) ||
2026 WARN_ON(!q->ops->buf_queue))
2029 INIT_LIST_HEAD(&q->queued_list);
2030 INIT_LIST_HEAD(&q->done_list);
2031 spin_lock_init(&q->done_lock);
2032 mutex_init(&q->mmap_lock);
2033 init_waitqueue_head(&q->done_wq);
2035 if (q->buf_struct_size == 0)
2036 q->buf_struct_size = sizeof(struct vb2_buffer);
2038 if (q->bidirectional)
2039 q->dma_dir = DMA_BIDIRECTIONAL;
2041 q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
2045 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
2047 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2048 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2049 void vb2_core_queue_release(struct vb2_queue *q)
2051 __vb2_cleanup_fileio(q);
2052 __vb2_queue_cancel(q);
2053 mutex_lock(&q->mmap_lock);
2054 __vb2_queue_free(q, q->num_buffers);
2055 mutex_unlock(&q->mmap_lock);
2057 EXPORT_SYMBOL_GPL(vb2_core_queue_release);
2059 unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
2062 unsigned long req_events = poll_requested_events(wait);
2063 struct vb2_buffer *vb = NULL;
2064 unsigned long flags;
2066 if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
2068 if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
2072 * Start file I/O emulator only if streaming API has not been used yet.
2074 if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
2075 if (!q->is_output && (q->io_modes & VB2_READ) &&
2076 (req_events & (POLLIN | POLLRDNORM))) {
2077 if (__vb2_init_fileio(q, 1))
2080 if (q->is_output && (q->io_modes & VB2_WRITE) &&
2081 (req_events & (POLLOUT | POLLWRNORM))) {
2082 if (__vb2_init_fileio(q, 0))
2085 * Write to OUTPUT queue can be done immediately.
2087 return POLLOUT | POLLWRNORM;
2092 * There is nothing to wait for if the queue isn't streaming, or if the
2093 * error flag is set.
2095 if (!vb2_is_streaming(q) || q->error)
2099 * If this quirk is set and QBUF hasn't been called yet then
2100 * return POLLERR as well. This only affects capture queues, output
2101 * queues will always initialize waiting_for_buffers to false.
2102 * This quirk is set by V4L2 for backwards compatibility reasons.
2104 if (q->quirk_poll_must_check_waiting_for_buffers &&
2105 q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM)))
2109 * For output streams you can call write() as long as there are fewer
2110 * buffers queued than there are buffers available.
2112 if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
2113 return POLLOUT | POLLWRNORM;
2115 if (list_empty(&q->done_list)) {
2117 * If the last buffer was dequeued from a capture queue,
2118 * return immediately. DQBUF will return -EPIPE.
2120 if (q->last_buffer_dequeued)
2121 return POLLIN | POLLRDNORM;
2123 poll_wait(file, &q->done_wq, wait);
2127 * Take first buffer available for dequeuing.
2129 spin_lock_irqsave(&q->done_lock, flags);
2130 if (!list_empty(&q->done_list))
2131 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2133 spin_unlock_irqrestore(&q->done_lock, flags);
2135 if (vb && (vb->state == VB2_BUF_STATE_DONE
2136 || vb->state == VB2_BUF_STATE_ERROR)) {
2137 return (q->is_output) ?
2138 POLLOUT | POLLWRNORM :
2139 POLLIN | POLLRDNORM;
2143 EXPORT_SYMBOL_GPL(vb2_core_poll);
2146 * struct vb2_fileio_buf - buffer context used by file io emulator
2148 * vb2 provides a compatibility layer and emulator of file io (read and
2149 * write) calls on top of streaming API. This structure is used for
2150 * tracking context related to the buffers.
2152 struct vb2_fileio_buf {
2156 unsigned int queued:1;
2160 * struct vb2_fileio_data - queue context used by file io emulator
2162 * @cur_index: the index of the buffer currently being read from or
2163 * written to. If equal to q->num_buffers then a new buffer
2165 * @initial_index: in the read() case all buffers are queued up immediately
2166 * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
2167 * buffers. However, in the write() case no buffers are initially
2168 * queued, instead whenever a buffer is full it is queued up by
2169 * __vb2_perform_fileio(). Only once all available buffers have
2170 * been queued up will __vb2_perform_fileio() start to dequeue
2171 * buffers. This means that initially __vb2_perform_fileio()
2172 * needs to know what buffer index to use when it is queuing up
2173 * the buffers for the first time. That initial index is stored
2174 * in this field. Once it is equal to q->num_buffers all
2175 * available buffers have been queued and __vb2_perform_fileio()
2176 * should start the normal dequeue/queue cycle.
2178 * vb2 provides a compatibility layer and emulator of file io (read and
2179 * write) calls on top of streaming API. For proper operation it required
2180 * this structure to save the driver state between each call of the read
2181 * or write function.
2183 struct vb2_fileio_data {
2186 unsigned int memory;
2187 struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
2188 unsigned int cur_index;
2189 unsigned int initial_index;
2190 unsigned int q_count;
2191 unsigned int dq_count;
2192 unsigned read_once:1;
2193 unsigned write_immediately:1;
2197 * __vb2_init_fileio() - initialize file io emulator
2198 * @q: videobuf2 queue
2199 * @read: mode selector (1 means read, 0 means write)
2201 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2203 struct vb2_fileio_data *fileio;
2205 unsigned int count = 0;
2210 if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
2211 (!read && !(q->io_modes & VB2_WRITE))))
2215 * Check if device supports mapping buffers to kernel virtual space.
2217 if (!q->mem_ops->vaddr)
2221 * Check if streaming api has not been already activated.
2223 if (q->streaming || q->num_buffers > 0)
2227 * Start with count 1, driver can increase it in queue_setup()
2231 dprintk(3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
2232 (read) ? "read" : "write", count, q->fileio_read_once,
2233 q->fileio_write_immediately);
2235 fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
2239 fileio->read_once = q->fileio_read_once;
2240 fileio->write_immediately = q->fileio_write_immediately;
2243 * Request buffers and use MMAP type to force driver
2244 * to allocate buffers by itself.
2246 fileio->count = count;
2247 fileio->memory = VB2_MEMORY_MMAP;
2248 fileio->type = q->type;
2250 ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2255 * Check if plane_count is correct
2256 * (multiplane buffers are not supported).
2258 if (q->bufs[0]->num_planes != 1) {
2264 * Get kernel address of each buffer.
2266 for (i = 0; i < q->num_buffers; i++) {
2267 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2268 if (fileio->bufs[i].vaddr == NULL) {
2272 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2276 * Read mode requires pre queuing of all buffers.
2280 * Queue all buffers.
2282 for (i = 0; i < q->num_buffers; i++) {
2283 ret = vb2_core_qbuf(q, i, NULL);
2286 fileio->bufs[i].queued = 1;
2289 * All buffers have been queued, so mark that by setting
2290 * initial_index to q->num_buffers
2292 fileio->initial_index = q->num_buffers;
2293 fileio->cur_index = q->num_buffers;
2299 ret = vb2_core_streamon(q, q->type);
2307 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2316 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2317 * @q: videobuf2 queue
2319 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2321 struct vb2_fileio_data *fileio = q->fileio;
2324 vb2_core_streamoff(q, q->type);
2327 vb2_core_reqbufs(q, fileio->memory, &fileio->count);
2329 dprintk(3, "file io emulator closed\n");
2335 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2336 * @q: videobuf2 queue
2337 * @data: pointed to target userspace buffer
2338 * @count: number of bytes to read or write
2339 * @ppos: file handle position tracking pointer
2340 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2341 * @read: access mode selector (1 means read, 0 means write)
2343 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2344 loff_t *ppos, int nonblock, int read)
2346 struct vb2_fileio_data *fileio;
2347 struct vb2_fileio_buf *buf;
2348 bool is_multiplanar = q->is_multiplanar;
2350 * When using write() to write data to an output video node the vb2 core
2351 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
2352 * else is able to provide this information with the write() operation.
2354 bool copy_timestamp = !read && q->copy_timestamp;
2358 dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
2359 read ? "read" : "write", (long)*ppos, count,
2360 nonblock ? "non" : "");
2366 * Initialize emulator on first call.
2368 if (!vb2_fileio_is_active(q)) {
2369 ret = __vb2_init_fileio(q, read);
2370 dprintk(3, "vb2_init_fileio result: %d\n", ret);
2377 * Check if we need to dequeue the buffer.
2379 index = fileio->cur_index;
2380 if (index >= q->num_buffers) {
2381 struct vb2_buffer *b;
2384 * Call vb2_dqbuf to get buffer back.
2386 ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
2387 dprintk(5, "vb2_dqbuf result: %d\n", ret);
2390 fileio->dq_count += 1;
2392 fileio->cur_index = index;
2393 buf = &fileio->bufs[index];
2397 * Get number of bytes filled by the driver
2401 buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
2402 : vb2_plane_size(q->bufs[index], 0);
2403 /* Compensate for data_offset on read in the multiplanar case. */
2404 if (is_multiplanar && read &&
2405 b->planes[0].data_offset < buf->size) {
2406 buf->pos = b->planes[0].data_offset;
2407 buf->size -= buf->pos;
2410 buf = &fileio->bufs[index];
2414 * Limit count on last few bytes of the buffer.
2416 if (buf->pos + count > buf->size) {
2417 count = buf->size - buf->pos;
2418 dprintk(5, "reducing read count: %zd\n", count);
2422 * Transfer data to userspace.
2424 dprintk(3, "copying %zd bytes - buffer %d, offset %u\n",
2425 count, index, buf->pos);
2427 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2429 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2431 dprintk(3, "error copying data\n");
2442 * Queue next buffer if required.
2444 if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
2445 struct vb2_buffer *b = q->bufs[index];
2448 * Check if this is the last buffer to read.
2450 if (read && fileio->read_once && fileio->dq_count == 1) {
2451 dprintk(3, "read limit reached\n");
2452 return __vb2_cleanup_fileio(q);
2456 * Call vb2_qbuf and give buffer to the driver.
2458 b->planes[0].bytesused = buf->pos;
2461 b->timestamp = ktime_get_ns();
2462 ret = vb2_core_qbuf(q, index, NULL);
2463 dprintk(5, "vb2_dbuf result: %d\n", ret);
2468 * Buffer has been queued, update the status
2472 buf->size = vb2_plane_size(q->bufs[index], 0);
2473 fileio->q_count += 1;
2475 * If we are queuing up buffers for the first time, then
2476 * increase initial_index by one.
2478 if (fileio->initial_index < q->num_buffers)
2479 fileio->initial_index++;
2481 * The next buffer to use is either a buffer that's going to be
2482 * queued for the first time (initial_index < q->num_buffers)
2483 * or it is equal to q->num_buffers, meaning that the next
2484 * time we need to dequeue a buffer since we've now queued up
2485 * all the 'first time' buffers.
2487 fileio->cur_index = fileio->initial_index;
2491 * Return proper number of bytes processed.
2498 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2499 loff_t *ppos, int nonblocking)
2501 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2503 EXPORT_SYMBOL_GPL(vb2_read);
2505 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2506 loff_t *ppos, int nonblocking)
2508 return __vb2_perform_fileio(q, (char __user *) data, count,
2509 ppos, nonblocking, 0);
2511 EXPORT_SYMBOL_GPL(vb2_write);
2513 struct vb2_threadio_data {
2514 struct task_struct *thread;
2520 static int vb2_thread(void *data)
2522 struct vb2_queue *q = data;
2523 struct vb2_threadio_data *threadio = q->threadio;
2524 bool copy_timestamp = false;
2525 unsigned prequeue = 0;
2530 prequeue = q->num_buffers;
2531 copy_timestamp = q->copy_timestamp;
2537 struct vb2_buffer *vb;
2540 * Call vb2_dqbuf to get buffer back.
2543 vb = q->bufs[index++];
2546 call_void_qop(q, wait_finish, q);
2547 if (!threadio->stop)
2548 ret = vb2_core_dqbuf(q, &index, NULL, 0);
2549 call_void_qop(q, wait_prepare, q);
2550 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2552 vb = q->bufs[index];
2554 if (ret || threadio->stop)
2558 if (vb->state != VB2_BUF_STATE_ERROR)
2559 if (threadio->fnc(vb, threadio->priv))
2561 call_void_qop(q, wait_finish, q);
2563 vb->timestamp = ktime_get_ns();;
2564 if (!threadio->stop)
2565 ret = vb2_core_qbuf(q, vb->index, NULL);
2566 call_void_qop(q, wait_prepare, q);
2567 if (ret || threadio->stop)
2571 /* Hmm, linux becomes *very* unhappy without this ... */
2572 while (!kthread_should_stop()) {
2573 set_current_state(TASK_INTERRUPTIBLE);
2580 * This function should not be used for anything else but the videobuf2-dvb
2581 * support. If you think you have another good use-case for this, then please
2582 * contact the linux-media mailinglist first.
2584 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
2585 const char *thread_name)
2587 struct vb2_threadio_data *threadio;
2594 if (WARN_ON(q->fileio))
2597 threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
2598 if (threadio == NULL)
2600 threadio->fnc = fnc;
2601 threadio->priv = priv;
2603 ret = __vb2_init_fileio(q, !q->is_output);
2604 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2607 q->threadio = threadio;
2608 threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
2609 if (IS_ERR(threadio->thread)) {
2610 ret = PTR_ERR(threadio->thread);
2611 threadio->thread = NULL;
2617 __vb2_cleanup_fileio(q);
2622 EXPORT_SYMBOL_GPL(vb2_thread_start);
2624 int vb2_thread_stop(struct vb2_queue *q)
2626 struct vb2_threadio_data *threadio = q->threadio;
2629 if (threadio == NULL)
2631 threadio->stop = true;
2632 /* Wake up all pending sleeps in the thread */
2634 err = kthread_stop(threadio->thread);
2635 __vb2_cleanup_fileio(q);
2636 threadio->thread = NULL;
2641 EXPORT_SYMBOL_GPL(vb2_thread_stop);
2643 MODULE_DESCRIPTION("Media buffer core framework");
2644 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2645 MODULE_LICENSE("GPL");