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1/*2 * videobuf2-v4l2.c - V4L2 driver helper framework3 *4 * Copyright (C) 2010 Samsung Electronics5 *6 * Author: Pawel Osciak <pawel@osciak.com>7 *	   Marek Szyprowski <m.szyprowski@samsung.com>8 *9 * The vb2_thread implementation was based on code from videobuf-dvb.c:10 *	(c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]11 *12 * This program is free software; you can redistribute it and/or modify13 * it under the terms of the GNU General Public License as published by14 * the Free Software Foundation.15 */16 17#include <linux/device.h>18#include <linux/err.h>19#include <linux/freezer.h>20#include <linux/kernel.h>21#include <linux/kthread.h>22#include <linux/mm.h>23#include <linux/module.h>24#include <linux/poll.h>25#include <linux/sched.h>26#include <linux/slab.h>27 28#include <media/v4l2-common.h>29#include <media/v4l2-dev.h>30#include <media/v4l2-device.h>31#include <media/v4l2-event.h>32#include <media/v4l2-fh.h>33 34#include <media/videobuf2-v4l2.h>35 36static int debug;37module_param(debug, int, 0644);38 39#define dprintk(q, level, fmt, arg...)					      \40	do {								      \41		if (debug >= level)					      \42			pr_info("vb2-v4l2: [%p] %s: " fmt,		      \43				(q)->name, __func__, ## arg);		      \44	} while (0)45 46/* Flags that are set by us */47#define V4L2_BUFFER_MASK_FLAGS	(V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \48				 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \49				 V4L2_BUF_FLAG_PREPARED | \50				 V4L2_BUF_FLAG_IN_REQUEST | \51				 V4L2_BUF_FLAG_REQUEST_FD | \52				 V4L2_BUF_FLAG_TIMESTAMP_MASK)53/* Output buffer flags that should be passed on to the driver */54#define V4L2_BUFFER_OUT_FLAGS	(V4L2_BUF_FLAG_PFRAME | \55				 V4L2_BUF_FLAG_BFRAME | \56				 V4L2_BUF_FLAG_KEYFRAME | \57				 V4L2_BUF_FLAG_TIMECODE | \58				 V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF)59 60/*61 * __verify_planes_array() - verify that the planes array passed in struct62 * v4l2_buffer from userspace can be safely used63 */64static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)65{66	if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))67		return 0;68 69	/* Is memory for copying plane information present? */70	if (b->m.planes == NULL) {71		dprintk(vb->vb2_queue, 1,72			"multi-planar buffer passed but planes array not provided\n");73		return -EINVAL;74	}75 76	if (b->length < vb->num_planes || b->length > VB2_MAX_PLANES) {77		dprintk(vb->vb2_queue, 1,78			"incorrect planes array length, expected %d, got %d\n",79			vb->num_planes, b->length);80		return -EINVAL;81	}82 83	return 0;84}85 86static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb)87{88	return __verify_planes_array(vb, pb);89}90 91/*92 * __verify_length() - Verify that the bytesused value for each plane fits in93 * the plane length and that the data offset doesn't exceed the bytesused value.94 */95static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)96{97	unsigned int length;98	unsigned int bytesused;99	unsigned int plane;100 101	if (V4L2_TYPE_IS_CAPTURE(b->type))102		return 0;103 104	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {105		for (plane = 0; plane < vb->num_planes; ++plane) {106			length = (b->memory == VB2_MEMORY_USERPTR ||107				  b->memory == VB2_MEMORY_DMABUF)108			       ? b->m.planes[plane].length109				: vb->planes[plane].length;110			bytesused = b->m.planes[plane].bytesused111				  ? b->m.planes[plane].bytesused : length;112 113			if (b->m.planes[plane].bytesused > length)114				return -EINVAL;115 116			if (b->m.planes[plane].data_offset > 0 &&117			    b->m.planes[plane].data_offset >= bytesused)118				return -EINVAL;119		}120	} else {121		length = (b->memory == VB2_MEMORY_USERPTR)122			? b->length : vb->planes[0].length;123 124		if (b->bytesused > length)125			return -EINVAL;126	}127 128	return 0;129}130 131/*132 * __init_vb2_v4l2_buffer() - initialize the vb2_v4l2_buffer struct133 */134static void __init_vb2_v4l2_buffer(struct vb2_buffer *vb)135{136	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);137 138	vbuf->request_fd = -1;139}140 141static void __copy_timestamp(struct vb2_buffer *vb, const void *pb)142{143	const struct v4l2_buffer *b = pb;144	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);145	struct vb2_queue *q = vb->vb2_queue;146 147	if (q->is_output) {148		/*149		 * For output buffers copy the timestamp if needed,150		 * and the timecode field and flag if needed.151		 */152		if (q->copy_timestamp)153			vb->timestamp = v4l2_buffer_get_timestamp(b);154		vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;155		if (b->flags & V4L2_BUF_FLAG_TIMECODE)156			vbuf->timecode = b->timecode;157	}158};159 160static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)161{162	static bool check_once;163 164	if (check_once)165		return;166 167	check_once = true;168 169	pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");170	if (vb->vb2_queue->allow_zero_bytesused)171		pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");172	else173		pr_warn("use the actual size instead.\n");174}175 176static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)177{178	struct vb2_queue *q = vb->vb2_queue;179	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);180	struct vb2_plane *planes = vbuf->planes;181	unsigned int plane;182	int ret;183 184	ret = __verify_length(vb, b);185	if (ret < 0) {186		dprintk(q, 1, "plane parameters verification failed: %d\n", ret);187		return ret;188	}189	if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {190		/*191		 * If the format's field is ALTERNATE, then the buffer's field192		 * should be either TOP or BOTTOM, not ALTERNATE since that193		 * makes no sense. The driver has to know whether the194		 * buffer represents a top or a bottom field in order to195		 * program any DMA correctly. Using ALTERNATE is wrong, since196		 * that just says that it is either a top or a bottom field,197		 * but not which of the two it is.198		 */199		dprintk(q, 1, "the field is incorrectly set to ALTERNATE for an output buffer\n");200		return -EINVAL;201	}202	vbuf->sequence = 0;203	vbuf->request_fd = -1;204	vbuf->is_held = false;205 206	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {207		switch (b->memory) {208		case VB2_MEMORY_USERPTR:209			for (plane = 0; plane < vb->num_planes; ++plane) {210				planes[plane].m.userptr =211					b->m.planes[plane].m.userptr;212				planes[plane].length =213					b->m.planes[plane].length;214			}215			break;216		case VB2_MEMORY_DMABUF:217			for (plane = 0; plane < vb->num_planes; ++plane) {218				planes[plane].m.fd =219					b->m.planes[plane].m.fd;220				planes[plane].length =221					b->m.planes[plane].length;222			}223			break;224		default:225			for (plane = 0; plane < vb->num_planes; ++plane) {226				planes[plane].m.offset =227					vb->planes[plane].m.offset;228				planes[plane].length =229					vb->planes[plane].length;230			}231			break;232		}233 234		/* Fill in driver-provided information for OUTPUT types */235		if (V4L2_TYPE_IS_OUTPUT(b->type)) {236			/*237			 * Will have to go up to b->length when API starts238			 * accepting variable number of planes.239			 *240			 * If bytesused == 0 for the output buffer, then fall241			 * back to the full buffer size. In that case242			 * userspace clearly never bothered to set it and243			 * it's a safe assumption that they really meant to244			 * use the full plane sizes.245			 *246			 * Some drivers, e.g. old codec drivers, use bytesused == 0247			 * as a way to indicate that streaming is finished.248			 * In that case, the driver should use the249			 * allow_zero_bytesused flag to keep old userspace250			 * applications working.251			 */252			for (plane = 0; plane < vb->num_planes; ++plane) {253				struct vb2_plane *pdst = &planes[plane];254				struct v4l2_plane *psrc = &b->m.planes[plane];255 256				if (psrc->bytesused == 0)257					vb2_warn_zero_bytesused(vb);258 259				if (vb->vb2_queue->allow_zero_bytesused)260					pdst->bytesused = psrc->bytesused;261				else262					pdst->bytesused = psrc->bytesused ?263						psrc->bytesused : pdst->length;264				pdst->data_offset = psrc->data_offset;265			}266		}267	} else {268		/*269		 * Single-planar buffers do not use planes array,270		 * so fill in relevant v4l2_buffer struct fields instead.271		 * In vb2 we use our internal V4l2_planes struct for272		 * single-planar buffers as well, for simplicity.273		 *274		 * If bytesused == 0 for the output buffer, then fall back275		 * to the full buffer size as that's a sensible default.276		 *277		 * Some drivers, e.g. old codec drivers, use bytesused == 0 as278		 * a way to indicate that streaming is finished. In that case,279		 * the driver should use the allow_zero_bytesused flag to keep280		 * old userspace applications working.281		 */282		switch (b->memory) {283		case VB2_MEMORY_USERPTR:284			planes[0].m.userptr = b->m.userptr;285			planes[0].length = b->length;286			break;287		case VB2_MEMORY_DMABUF:288			planes[0].m.fd = b->m.fd;289			planes[0].length = b->length;290			break;291		default:292			planes[0].m.offset = vb->planes[0].m.offset;293			planes[0].length = vb->planes[0].length;294			break;295		}296 297		planes[0].data_offset = 0;298		if (V4L2_TYPE_IS_OUTPUT(b->type)) {299			if (b->bytesused == 0)300				vb2_warn_zero_bytesused(vb);301 302			if (vb->vb2_queue->allow_zero_bytesused)303				planes[0].bytesused = b->bytesused;304			else305				planes[0].bytesused = b->bytesused ?306					b->bytesused : planes[0].length;307		} else308			planes[0].bytesused = 0;309 310	}311 312	/* Zero flags that we handle */313	vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;314	if (!vb->vb2_queue->copy_timestamp || V4L2_TYPE_IS_CAPTURE(b->type)) {315		/*316		 * Non-COPY timestamps and non-OUTPUT queues will get317		 * their timestamp and timestamp source flags from the318		 * queue.319		 */320		vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;321	}322 323	if (V4L2_TYPE_IS_OUTPUT(b->type)) {324		/*325		 * For output buffers mask out the timecode flag:326		 * this will be handled later in vb2_qbuf().327		 * The 'field' is valid metadata for this output buffer328		 * and so that needs to be copied here.329		 */330		vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;331		vbuf->field = b->field;332		if (!(q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF))333			vbuf->flags &= ~V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF;334	} else {335		/* Zero any output buffer flags as this is a capture buffer */336		vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;337		/* Zero last flag, this is a signal from driver to userspace */338		vbuf->flags &= ~V4L2_BUF_FLAG_LAST;339	}340 341	return 0;342}343 344static void set_buffer_cache_hints(struct vb2_queue *q,345				   struct vb2_buffer *vb,346				   struct v4l2_buffer *b)347{348	if (!vb2_queue_allows_cache_hints(q)) {349		/*350		 * Clear buffer cache flags if queue does not support user351		 * space hints. That's to indicate to userspace that these352		 * flags won't work.353		 */354		b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_INVALIDATE;355		b->flags &= ~V4L2_BUF_FLAG_NO_CACHE_CLEAN;356		return;357	}358 359	if (b->flags & V4L2_BUF_FLAG_NO_CACHE_INVALIDATE)360		vb->skip_cache_sync_on_finish = 1;361 362	if (b->flags & V4L2_BUF_FLAG_NO_CACHE_CLEAN)363		vb->skip_cache_sync_on_prepare = 1;364}365 366static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev,367				    struct vb2_buffer *vb, struct v4l2_buffer *b,368				    bool is_prepare, struct media_request **p_req)369{370	const char *opname = is_prepare ? "prepare_buf" : "qbuf";371	struct media_request *req;372	struct vb2_v4l2_buffer *vbuf;373	int ret;374 375	if (b->type != q->type) {376		dprintk(q, 1, "%s: invalid buffer type\n", opname);377		return -EINVAL;378	}379 380	if (b->memory != q->memory) {381		dprintk(q, 1, "%s: invalid memory type\n", opname);382		return -EINVAL;383	}384 385	vbuf = to_vb2_v4l2_buffer(vb);386	ret = __verify_planes_array(vb, b);387	if (ret)388		return ret;389 390	if (!is_prepare && (b->flags & V4L2_BUF_FLAG_REQUEST_FD) &&391	    vb->state != VB2_BUF_STATE_DEQUEUED) {392		dprintk(q, 1, "%s: buffer is not in dequeued state\n", opname);393		return -EINVAL;394	}395 396	if (!vb->prepared) {397		set_buffer_cache_hints(q, vb, b);398		/* Copy relevant information provided by the userspace */399		memset(vbuf->planes, 0,400		       sizeof(vbuf->planes[0]) * vb->num_planes);401		ret = vb2_fill_vb2_v4l2_buffer(vb, b);402		if (ret)403			return ret;404	}405 406	if (is_prepare)407		return 0;408 409	if (!(b->flags & V4L2_BUF_FLAG_REQUEST_FD)) {410		if (q->requires_requests) {411			dprintk(q, 1, "%s: queue requires requests\n", opname);412			return -EBADR;413		}414		if (q->uses_requests) {415			dprintk(q, 1, "%s: queue uses requests\n", opname);416			return -EBUSY;417		}418		return 0;419	} else if (!q->supports_requests) {420		dprintk(q, 1, "%s: queue does not support requests\n", opname);421		return -EBADR;422	} else if (q->uses_qbuf) {423		dprintk(q, 1, "%s: queue does not use requests\n", opname);424		return -EBUSY;425	}426 427	/*428	 * For proper locking when queueing a request you need to be able429	 * to lock access to the vb2 queue, so check that there is a lock430	 * that we can use. In addition p_req must be non-NULL.431	 */432	if (WARN_ON(!q->lock || !p_req))433		return -EINVAL;434 435	/*436	 * Make sure this op is implemented by the driver. It's easy to forget437	 * this callback, but is it important when canceling a buffer in a438	 * queued request.439	 */440	if (WARN_ON(!q->ops->buf_request_complete))441		return -EINVAL;442	/*443	 * Make sure this op is implemented by the driver for the output queue.444	 * It's easy to forget this callback, but is it important to correctly445	 * validate the 'field' value at QBUF time.446	 */447	if (WARN_ON((q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT ||448		     q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) &&449		    !q->ops->buf_out_validate))450		return -EINVAL;451 452	req = media_request_get_by_fd(mdev, b->request_fd);453	if (IS_ERR(req)) {454		dprintk(q, 1, "%s: invalid request_fd\n", opname);455		return PTR_ERR(req);456	}457 458	/*459	 * Early sanity check. This is checked again when the buffer460	 * is bound to the request in vb2_core_qbuf().461	 */462	if (req->state != MEDIA_REQUEST_STATE_IDLE &&463	    req->state != MEDIA_REQUEST_STATE_UPDATING) {464		dprintk(q, 1, "%s: request is not idle\n", opname);465		media_request_put(req);466		return -EBUSY;467	}468 469	*p_req = req;470	vbuf->request_fd = b->request_fd;471 472	return 0;473}474 475/*476 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be477 * returned to userspace478 */479static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)480{481	struct v4l2_buffer *b = pb;482	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);483	struct vb2_queue *q = vb->vb2_queue;484	unsigned int plane;485 486	/* Copy back data such as timestamp, flags, etc. */487	b->index = vb->index;488	b->type = vb->type;489	b->memory = vb->memory;490	b->bytesused = 0;491 492	b->flags = vbuf->flags;493	b->field = vbuf->field;494	v4l2_buffer_set_timestamp(b, vb->timestamp);495	b->timecode = vbuf->timecode;496	b->sequence = vbuf->sequence;497	b->reserved2 = 0;498	b->request_fd = 0;499 500	if (q->is_multiplanar) {501		/*502		 * Fill in plane-related data if userspace provided an array503		 * for it. The caller has already verified memory and size.504		 */505		b->length = vb->num_planes;506		for (plane = 0; plane < vb->num_planes; ++plane) {507			struct v4l2_plane *pdst = &b->m.planes[plane];508			struct vb2_plane *psrc = &vb->planes[plane];509 510			pdst->bytesused = psrc->bytesused;511			pdst->length = psrc->length;512			if (q->memory == VB2_MEMORY_MMAP)513				pdst->m.mem_offset = psrc->m.offset;514			else if (q->memory == VB2_MEMORY_USERPTR)515				pdst->m.userptr = psrc->m.userptr;516			else if (q->memory == VB2_MEMORY_DMABUF)517				pdst->m.fd = psrc->m.fd;518			pdst->data_offset = psrc->data_offset;519			memset(pdst->reserved, 0, sizeof(pdst->reserved));520		}521	} else {522		/*523		 * We use length and offset in v4l2_planes array even for524		 * single-planar buffers, but userspace does not.525		 */526		b->length = vb->planes[0].length;527		b->bytesused = vb->planes[0].bytesused;528		if (q->memory == VB2_MEMORY_MMAP)529			b->m.offset = vb->planes[0].m.offset;530		else if (q->memory == VB2_MEMORY_USERPTR)531			b->m.userptr = vb->planes[0].m.userptr;532		else if (q->memory == VB2_MEMORY_DMABUF)533			b->m.fd = vb->planes[0].m.fd;534	}535 536	/*537	 * Clear any buffer state related flags.538	 */539	b->flags &= ~V4L2_BUFFER_MASK_FLAGS;540	b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;541	if (!q->copy_timestamp) {542		/*543		 * For non-COPY timestamps, drop timestamp source bits544		 * and obtain the timestamp source from the queue.545		 */546		b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;547		b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;548	}549 550	switch (vb->state) {551	case VB2_BUF_STATE_QUEUED:552	case VB2_BUF_STATE_ACTIVE:553		b->flags |= V4L2_BUF_FLAG_QUEUED;554		break;555	case VB2_BUF_STATE_IN_REQUEST:556		b->flags |= V4L2_BUF_FLAG_IN_REQUEST;557		break;558	case VB2_BUF_STATE_ERROR:559		b->flags |= V4L2_BUF_FLAG_ERROR;560		fallthrough;561	case VB2_BUF_STATE_DONE:562		b->flags |= V4L2_BUF_FLAG_DONE;563		break;564	case VB2_BUF_STATE_PREPARING:565	case VB2_BUF_STATE_DEQUEUED:566		/* nothing */567		break;568	}569 570	if ((vb->state == VB2_BUF_STATE_DEQUEUED ||571	     vb->state == VB2_BUF_STATE_IN_REQUEST) &&572	    vb->synced && vb->prepared)573		b->flags |= V4L2_BUF_FLAG_PREPARED;574 575	if (vb2_buffer_in_use(q, vb))576		b->flags |= V4L2_BUF_FLAG_MAPPED;577	if (vbuf->request_fd >= 0) {578		b->flags |= V4L2_BUF_FLAG_REQUEST_FD;579		b->request_fd = vbuf->request_fd;580	}581}582 583/*584 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a585 * v4l2_buffer by the userspace. It also verifies that struct586 * v4l2_buffer has a valid number of planes.587 */588static int __fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)589{590	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);591	unsigned int plane;592 593	if (!vb->vb2_queue->copy_timestamp)594		vb->timestamp = 0;595 596	for (plane = 0; plane < vb->num_planes; ++plane) {597		if (vb->vb2_queue->memory != VB2_MEMORY_MMAP) {598			planes[plane].m = vbuf->planes[plane].m;599			planes[plane].length = vbuf->planes[plane].length;600		}601		planes[plane].bytesused = vbuf->planes[plane].bytesused;602		planes[plane].data_offset = vbuf->planes[plane].data_offset;603	}604	return 0;605}606 607static const struct vb2_buf_ops v4l2_buf_ops = {608	.verify_planes_array	= __verify_planes_array_core,609	.init_buffer		= __init_vb2_v4l2_buffer,610	.fill_user_buffer	= __fill_v4l2_buffer,611	.fill_vb2_buffer	= __fill_vb2_buffer,612	.copy_timestamp		= __copy_timestamp,613};614 615struct vb2_buffer *vb2_find_buffer(struct vb2_queue *q, u64 timestamp)616{617	unsigned int i;618	struct vb2_buffer *vb2;619 620	/*621	 * This loop doesn't scale if there is a really large number of buffers.622	 * Maybe something more efficient will be needed in this case.623	 */624	for (i = 0; i < q->max_num_buffers; i++) {625		vb2 = vb2_get_buffer(q, i);626 627		if (!vb2)628			continue;629 630		if (vb2->copied_timestamp &&631		    vb2->timestamp == timestamp)632			return vb2;633	}634	return NULL;635}636EXPORT_SYMBOL_GPL(vb2_find_buffer);637 638/*639 * vb2_querybuf() - query video buffer information640 * @q:		vb2 queue641 * @b:		buffer struct passed from userspace to vidioc_querybuf handler642 *		in driver643 *644 * Should be called from vidioc_querybuf ioctl handler in driver.645 * This function will verify the passed v4l2_buffer structure and fill the646 * relevant information for the userspace.647 *648 * The return values from this function are intended to be directly returned649 * from vidioc_querybuf handler in driver.650 */651int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)652{653	struct vb2_buffer *vb;654	int ret;655 656	if (b->type != q->type) {657		dprintk(q, 1, "wrong buffer type\n");658		return -EINVAL;659	}660 661	vb = vb2_get_buffer(q, b->index);662	if (!vb) {663		dprintk(q, 1, "can't find the requested buffer %u\n", b->index);664		return -EINVAL;665	}666 667	ret = __verify_planes_array(vb, b);668	if (!ret)669		vb2_core_querybuf(q, vb, b);670	return ret;671}672EXPORT_SYMBOL(vb2_querybuf);673 674static void vb2_set_flags_and_caps(struct vb2_queue *q, u32 memory,675				   u32 *flags, u32 *caps, u32 *max_num_bufs)676{677	if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP) {678		/*679		 * This needs to clear V4L2_MEMORY_FLAG_NON_COHERENT only,680		 * but in order to avoid bugs we zero out all bits.681		 */682		*flags = 0;683	} else {684		/* Clear all unknown flags. */685		*flags &= V4L2_MEMORY_FLAG_NON_COHERENT;686	}687 688	*caps |= V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS;689	if (q->io_modes & VB2_MMAP)690		*caps |= V4L2_BUF_CAP_SUPPORTS_MMAP;691	if (q->io_modes & VB2_USERPTR)692		*caps |= V4L2_BUF_CAP_SUPPORTS_USERPTR;693	if (q->io_modes & VB2_DMABUF)694		*caps |= V4L2_BUF_CAP_SUPPORTS_DMABUF;695	if (q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF)696		*caps |= V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF;697	if (q->allow_cache_hints && q->io_modes & VB2_MMAP)698		*caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;699	if (q->supports_requests)700		*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;701	if (max_num_bufs) {702		*max_num_bufs = q->max_num_buffers;703		*caps |= V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS;704	}705}706 707int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)708{709	int ret = vb2_verify_memory_type(q, req->memory, req->type);710	u32 flags = req->flags;711 712	vb2_set_flags_and_caps(q, req->memory, &flags,713			       &req->capabilities, NULL);714	req->flags = flags;715	return ret ? ret : vb2_core_reqbufs(q, req->memory,716					    req->flags, &req->count);717}718EXPORT_SYMBOL_GPL(vb2_reqbufs);719 720int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,721		    struct v4l2_buffer *b)722{723	struct vb2_buffer *vb;724	int ret;725 726	if (vb2_fileio_is_active(q)) {727		dprintk(q, 1, "file io in progress\n");728		return -EBUSY;729	}730 731	if (b->flags & V4L2_BUF_FLAG_REQUEST_FD)732		return -EINVAL;733 734	vb = vb2_get_buffer(q, b->index);735	if (!vb) {736		dprintk(q, 1, "can't find the requested buffer %u\n", b->index);737		return -EINVAL;738	}739 740	ret = vb2_queue_or_prepare_buf(q, mdev, vb, b, true, NULL);741 742	return ret ? ret : vb2_core_prepare_buf(q, vb, b);743}744EXPORT_SYMBOL_GPL(vb2_prepare_buf);745 746int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)747{748	unsigned requested_planes = 1;749	unsigned requested_sizes[VIDEO_MAX_PLANES];750	struct v4l2_format *f = &create->format;751	int ret = vb2_verify_memory_type(q, create->memory, f->type);752	unsigned i;753 754	create->index = vb2_get_num_buffers(q);755	vb2_set_flags_and_caps(q, create->memory, &create->flags,756			       &create->capabilities, &create->max_num_buffers);757	if (create->count == 0)758		return ret != -EBUSY ? ret : 0;759 760	switch (f->type) {761	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:762	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:763		requested_planes = f->fmt.pix_mp.num_planes;764		if (requested_planes == 0 ||765		    requested_planes > VIDEO_MAX_PLANES)766			return -EINVAL;767		for (i = 0; i < requested_planes; i++)768			requested_sizes[i] =769				f->fmt.pix_mp.plane_fmt[i].sizeimage;770		break;771	case V4L2_BUF_TYPE_VIDEO_CAPTURE:772	case V4L2_BUF_TYPE_VIDEO_OUTPUT:773		requested_sizes[0] = f->fmt.pix.sizeimage;774		break;775	case V4L2_BUF_TYPE_VBI_CAPTURE:776	case V4L2_BUF_TYPE_VBI_OUTPUT:777		requested_sizes[0] = f->fmt.vbi.samples_per_line *778			(f->fmt.vbi.count[0] + f->fmt.vbi.count[1]);779		break;780	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:781	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:782		requested_sizes[0] = f->fmt.sliced.io_size;783		break;784	case V4L2_BUF_TYPE_SDR_CAPTURE:785	case V4L2_BUF_TYPE_SDR_OUTPUT:786		requested_sizes[0] = f->fmt.sdr.buffersize;787		break;788	case V4L2_BUF_TYPE_META_CAPTURE:789	case V4L2_BUF_TYPE_META_OUTPUT:790		requested_sizes[0] = f->fmt.meta.buffersize;791		break;792	default:793		return -EINVAL;794	}795	for (i = 0; i < requested_planes; i++)796		if (requested_sizes[i] == 0)797			return -EINVAL;798	if (ret)799		return ret;800 801	return vb2_core_create_bufs(q, create->memory,802				    create->flags,803				    &create->count,804				    requested_planes,805				    requested_sizes,806				    &create->index);807}808EXPORT_SYMBOL_GPL(vb2_create_bufs);809 810int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,811	     struct v4l2_buffer *b)812{813	struct media_request *req = NULL;814	struct vb2_buffer *vb;815	int ret;816 817	if (vb2_fileio_is_active(q)) {818		dprintk(q, 1, "file io in progress\n");819		return -EBUSY;820	}821 822	vb = vb2_get_buffer(q, b->index);823	if (!vb) {824		dprintk(q, 1, "can't find the requested buffer %u\n", b->index);825		return -EINVAL;826	}827 828	ret = vb2_queue_or_prepare_buf(q, mdev, vb, b, false, &req);829	if (ret)830		return ret;831	ret = vb2_core_qbuf(q, vb, b, req);832	if (req)833		media_request_put(req);834	return ret;835}836EXPORT_SYMBOL_GPL(vb2_qbuf);837 838int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)839{840	int ret;841 842	if (vb2_fileio_is_active(q)) {843		dprintk(q, 1, "file io in progress\n");844		return -EBUSY;845	}846 847	if (b->type != q->type) {848		dprintk(q, 1, "invalid buffer type\n");849		return -EINVAL;850	}851 852	ret = vb2_core_dqbuf(q, NULL, b, nonblocking);853 854	if (!q->is_output &&855	    b->flags & V4L2_BUF_FLAG_DONE &&856	    b->flags & V4L2_BUF_FLAG_LAST)857		q->last_buffer_dequeued = true;858 859	/*860	 *  After calling the VIDIOC_DQBUF V4L2_BUF_FLAG_DONE must be861	 *  cleared.862	 */863	b->flags &= ~V4L2_BUF_FLAG_DONE;864 865	return ret;866}867EXPORT_SYMBOL_GPL(vb2_dqbuf);868 869int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)870{871	if (vb2_fileio_is_active(q)) {872		dprintk(q, 1, "file io in progress\n");873		return -EBUSY;874	}875	return vb2_core_streamon(q, type);876}877EXPORT_SYMBOL_GPL(vb2_streamon);878 879int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)880{881	if (vb2_fileio_is_active(q)) {882		dprintk(q, 1, "file io in progress\n");883		return -EBUSY;884	}885	return vb2_core_streamoff(q, type);886}887EXPORT_SYMBOL_GPL(vb2_streamoff);888 889int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)890{891	struct vb2_buffer *vb;892 893	vb = vb2_get_buffer(q, eb->index);894	if (!vb) {895		dprintk(q, 1, "can't find the requested buffer %u\n", eb->index);896		return -EINVAL;897	}898 899	return vb2_core_expbuf(q, &eb->fd, eb->type, vb,900				eb->plane, eb->flags);901}902EXPORT_SYMBOL_GPL(vb2_expbuf);903 904int vb2_queue_init_name(struct vb2_queue *q, const char *name)905{906	/*907	 * Sanity check908	 */909	if (WARN_ON(!q)			  ||910	    WARN_ON(q->timestamp_flags &911		    ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |912		      V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))913		return -EINVAL;914 915	/* Warn that the driver should choose an appropriate timestamp type */916	WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==917		V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);918 919	/* Warn that vb2_memory should match with v4l2_memory */920	if (WARN_ON(VB2_MEMORY_MMAP != (int)V4L2_MEMORY_MMAP)921		|| WARN_ON(VB2_MEMORY_USERPTR != (int)V4L2_MEMORY_USERPTR)922		|| WARN_ON(VB2_MEMORY_DMABUF != (int)V4L2_MEMORY_DMABUF))923		return -EINVAL;924 925	if (q->buf_struct_size == 0)926		q->buf_struct_size = sizeof(struct vb2_v4l2_buffer);927 928	q->buf_ops = &v4l2_buf_ops;929	q->is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);930	q->is_output = V4L2_TYPE_IS_OUTPUT(q->type);931	q->copy_timestamp = (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK)932			== V4L2_BUF_FLAG_TIMESTAMP_COPY;933	/*934	 * For compatibility with vb1: if QBUF hasn't been called yet, then935	 * return EPOLLERR as well. This only affects capture queues, output936	 * queues will always initialize waiting_for_buffers to false.937	 */938	q->quirk_poll_must_check_waiting_for_buffers = true;939 940	if (name)941		strscpy(q->name, name, sizeof(q->name));942	else943		q->name[0] = '\0';944 945	return vb2_core_queue_init(q);946}947EXPORT_SYMBOL_GPL(vb2_queue_init_name);948 949int vb2_queue_init(struct vb2_queue *q)950{951	return vb2_queue_init_name(q, NULL);952}953EXPORT_SYMBOL_GPL(vb2_queue_init);954 955void vb2_queue_release(struct vb2_queue *q)956{957	vb2_core_queue_release(q);958}959EXPORT_SYMBOL_GPL(vb2_queue_release);960 961int vb2_queue_change_type(struct vb2_queue *q, unsigned int type)962{963	if (type == q->type)964		return 0;965 966	if (vb2_is_busy(q))967		return -EBUSY;968 969	q->type = type;970 971	return 0;972}973EXPORT_SYMBOL_GPL(vb2_queue_change_type);974 975__poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)976{977	struct video_device *vfd = video_devdata(file);978	__poll_t res;979 980	res = vb2_core_poll(q, file, wait);981 982	if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {983		struct v4l2_fh *fh = file->private_data;984 985		poll_wait(file, &fh->wait, wait);986		if (v4l2_event_pending(fh))987			res |= EPOLLPRI;988	}989 990	return res;991}992EXPORT_SYMBOL_GPL(vb2_poll);993 994/*995 * The following functions are not part of the vb2 core API, but are helper996 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations997 * and struct vb2_ops.998 * They contain boilerplate code that most if not all drivers have to do999 * and so they simplify the driver code.1000 */1001 1002/* vb2 ioctl helpers */1003 1004int vb2_ioctl_remove_bufs(struct file *file, void *priv,1005			  struct v4l2_remove_buffers *d)1006{1007	struct video_device *vdev = video_devdata(file);1008 1009	if (vdev->queue->type != d->type)1010		return -EINVAL;1011 1012	if (d->count == 0)1013		return 0;1014 1015	if (vb2_queue_is_busy(vdev->queue, file))1016		return -EBUSY;1017 1018	return vb2_core_remove_bufs(vdev->queue, d->index, d->count);1019}1020EXPORT_SYMBOL_GPL(vb2_ioctl_remove_bufs);1021 1022int vb2_ioctl_reqbufs(struct file *file, void *priv,1023			  struct v4l2_requestbuffers *p)1024{1025	struct video_device *vdev = video_devdata(file);1026	int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);1027	u32 flags = p->flags;1028 1029	vb2_set_flags_and_caps(vdev->queue, p->memory, &flags,1030			       &p->capabilities, NULL);1031	p->flags = flags;1032	if (res)1033		return res;1034	if (vb2_queue_is_busy(vdev->queue, file))1035		return -EBUSY;1036	res = vb2_core_reqbufs(vdev->queue, p->memory, p->flags, &p->count);1037	/* If count == 0, then the owner has released all buffers and he1038	   is no longer owner of the queue. Otherwise we have a new owner. */1039	if (res == 0)1040		vdev->queue->owner = p->count ? file->private_data : NULL;1041	return res;1042}1043EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);1044 1045int vb2_ioctl_create_bufs(struct file *file, void *priv,1046			  struct v4l2_create_buffers *p)1047{1048	struct video_device *vdev = video_devdata(file);1049	int res = vb2_verify_memory_type(vdev->queue, p->memory, p->format.type);1050 1051	p->index = vb2_get_num_buffers(vdev->queue);1052	vb2_set_flags_and_caps(vdev->queue, p->memory, &p->flags,1053			       &p->capabilities, &p->max_num_buffers);1054	/*1055	 * If count == 0, then just check if memory and type are valid.1056	 * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.1057	 */1058	if (p->count == 0)1059		return res != -EBUSY ? res : 0;1060	if (res)1061		return res;1062	if (vb2_queue_is_busy(vdev->queue, file))1063		return -EBUSY;1064 1065	res = vb2_create_bufs(vdev->queue, p);1066	if (res == 0)1067		vdev->queue->owner = file->private_data;1068	return res;1069}1070EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);1071 1072int vb2_ioctl_prepare_buf(struct file *file, void *priv,1073			  struct v4l2_buffer *p)1074{1075	struct video_device *vdev = video_devdata(file);1076 1077	if (vb2_queue_is_busy(vdev->queue, file))1078		return -EBUSY;1079	return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p);1080}1081EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);1082 1083int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)1084{1085	struct video_device *vdev = video_devdata(file);1086 1087	/* No need to call vb2_queue_is_busy(), anyone can query buffers. */1088	return vb2_querybuf(vdev->queue, p);1089}1090EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);1091 1092int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)1093{1094	struct video_device *vdev = video_devdata(file);1095 1096	if (vb2_queue_is_busy(vdev->queue, file))1097		return -EBUSY;1098	return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p);1099}1100EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);1101 1102int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)1103{1104	struct video_device *vdev = video_devdata(file);1105 1106	if (vb2_queue_is_busy(vdev->queue, file))1107		return -EBUSY;1108	return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);1109}1110EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);1111 1112int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)1113{1114	struct video_device *vdev = video_devdata(file);1115 1116	if (vb2_queue_is_busy(vdev->queue, file))1117		return -EBUSY;1118	return vb2_streamon(vdev->queue, i);1119}1120EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);1121 1122int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)1123{1124	struct video_device *vdev = video_devdata(file);1125 1126	if (vb2_queue_is_busy(vdev->queue, file))1127		return -EBUSY;1128	return vb2_streamoff(vdev->queue, i);1129}1130EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);1131 1132int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)1133{1134	struct video_device *vdev = video_devdata(file);1135 1136	if (vb2_queue_is_busy(vdev->queue, file))1137		return -EBUSY;1138	return vb2_expbuf(vdev->queue, p);1139}1140EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);1141 1142/* v4l2_file_operations helpers */1143 1144int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)1145{1146	struct video_device *vdev = video_devdata(file);1147 1148	return vb2_mmap(vdev->queue, vma);1149}1150EXPORT_SYMBOL_GPL(vb2_fop_mmap);1151 1152int _vb2_fop_release(struct file *file, struct mutex *lock)1153{1154	struct video_device *vdev = video_devdata(file);1155 1156	if (lock)1157		mutex_lock(lock);1158	if (!vdev->queue->owner || file->private_data == vdev->queue->owner) {1159		vb2_queue_release(vdev->queue);1160		vdev->queue->owner = NULL;1161	}1162	if (lock)1163		mutex_unlock(lock);1164	return v4l2_fh_release(file);1165}1166EXPORT_SYMBOL_GPL(_vb2_fop_release);1167 1168int vb2_fop_release(struct file *file)1169{1170	struct video_device *vdev = video_devdata(file);1171	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;1172 1173	return _vb2_fop_release(file, lock);1174}1175EXPORT_SYMBOL_GPL(vb2_fop_release);1176 1177ssize_t vb2_fop_write(struct file *file, const char __user *buf,1178		size_t count, loff_t *ppos)1179{1180	struct video_device *vdev = video_devdata(file);1181	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;1182	int err = -EBUSY;1183 1184	if (!(vdev->queue->io_modes & VB2_WRITE))1185		return -EINVAL;1186	if (lock && mutex_lock_interruptible(lock))1187		return -ERESTARTSYS;1188	if (vb2_queue_is_busy(vdev->queue, file))1189		goto exit;1190	err = vb2_write(vdev->queue, buf, count, ppos,1191		       file->f_flags & O_NONBLOCK);1192	if (vdev->queue->fileio)1193		vdev->queue->owner = file->private_data;1194exit:1195	if (lock)1196		mutex_unlock(lock);1197	return err;1198}1199EXPORT_SYMBOL_GPL(vb2_fop_write);1200 1201ssize_t vb2_fop_read(struct file *file, char __user *buf,1202		size_t count, loff_t *ppos)1203{1204	struct video_device *vdev = video_devdata(file);1205	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;1206	int err = -EBUSY;1207 1208	if (!(vdev->queue->io_modes & VB2_READ))1209		return -EINVAL;1210	if (lock && mutex_lock_interruptible(lock))1211		return -ERESTARTSYS;1212	if (vb2_queue_is_busy(vdev->queue, file))1213		goto exit;1214	vdev->queue->owner = file->private_data;1215	err = vb2_read(vdev->queue, buf, count, ppos,1216		       file->f_flags & O_NONBLOCK);1217	if (!vdev->queue->fileio)1218		vdev->queue->owner = NULL;1219exit:1220	if (lock)1221		mutex_unlock(lock);1222	return err;1223}1224EXPORT_SYMBOL_GPL(vb2_fop_read);1225 1226__poll_t vb2_fop_poll(struct file *file, poll_table *wait)1227{1228	struct video_device *vdev = video_devdata(file);1229	struct vb2_queue *q = vdev->queue;1230	struct mutex *lock = q->lock ? q->lock : vdev->lock;1231	__poll_t res;1232	void *fileio;1233 1234	/*1235	 * If this helper doesn't know how to lock, then you shouldn't be using1236	 * it but you should write your own.1237	 */1238	WARN_ON(!lock);1239 1240	if (lock && mutex_lock_interruptible(lock))1241		return EPOLLERR;1242 1243	fileio = q->fileio;1244 1245	res = vb2_poll(vdev->queue, file, wait);1246 1247	/* If fileio was started, then we have a new queue owner. */1248	if (!fileio && q->fileio)1249		q->owner = file->private_data;1250	if (lock)1251		mutex_unlock(lock);1252	return res;1253}1254EXPORT_SYMBOL_GPL(vb2_fop_poll);1255 1256#ifndef CONFIG_MMU1257unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,1258		unsigned long len, unsigned long pgoff, unsigned long flags)1259{1260	struct video_device *vdev = video_devdata(file);1261 1262	return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);1263}1264EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);1265#endif1266 1267void vb2_video_unregister_device(struct video_device *vdev)1268{1269	/* Check if vdev was ever registered at all */1270	if (!vdev || !video_is_registered(vdev))1271		return;1272 1273	/*1274	 * Calling this function only makes sense if vdev->queue is set.1275	 * If it is NULL, then just call video_unregister_device() instead.1276	 */1277	WARN_ON(!vdev->queue);1278 1279	/*1280	 * Take a reference to the device since video_unregister_device()1281	 * calls device_unregister(), but we don't want that to release1282	 * the device since we want to clean up the queue first.1283	 */1284	get_device(&vdev->dev);1285	video_unregister_device(vdev);1286	if (vdev->queue) {1287		struct mutex *lock = vdev->queue->lock ?1288			vdev->queue->lock : vdev->lock;1289 1290		if (lock)1291			mutex_lock(lock);1292		vb2_queue_release(vdev->queue);1293		vdev->queue->owner = NULL;1294		if (lock)1295			mutex_unlock(lock);1296	}1297	/*1298	 * Now we put the device, and in most cases this will release1299	 * everything.1300	 */1301	put_device(&vdev->dev);1302}1303EXPORT_SYMBOL_GPL(vb2_video_unregister_device);1304 1305/* vb2_ops helpers. Only use if vq->lock is non-NULL. */1306 1307void vb2_ops_wait_prepare(struct vb2_queue *vq)1308{1309	mutex_unlock(vq->lock);1310}1311EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);1312 1313void vb2_ops_wait_finish(struct vb2_queue *vq)1314{1315	mutex_lock(vq->lock);1316}1317EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);1318 1319/*1320 * Note that this function is called during validation time and1321 * thus the req_queue_mutex is held to ensure no request objects1322 * can be added or deleted while validating. So there is no need1323 * to protect the objects list.1324 */1325int vb2_request_validate(struct media_request *req)1326{1327	struct media_request_object *obj;1328	int ret = 0;1329 1330	if (!vb2_request_buffer_cnt(req))1331		return -ENOENT;1332 1333	list_for_each_entry(obj, &req->objects, list) {1334		if (!obj->ops->prepare)1335			continue;1336 1337		ret = obj->ops->prepare(obj);1338		if (ret)1339			break;1340	}1341 1342	if (ret) {1343		list_for_each_entry_continue_reverse(obj, &req->objects, list)1344			if (obj->ops->unprepare)1345				obj->ops->unprepare(obj);1346		return ret;1347	}1348	return 0;1349}1350EXPORT_SYMBOL_GPL(vb2_request_validate);1351 1352void vb2_request_queue(struct media_request *req)1353{1354	struct media_request_object *obj, *obj_safe;1355 1356	/*1357	 * Queue all objects. Note that buffer objects are at the end of the1358	 * objects list, after all other object types. Once buffer objects1359	 * are queued, the driver might delete them immediately (if the driver1360	 * processes the buffer at once), so we have to use1361	 * list_for_each_entry_safe() to handle the case where the object we1362	 * queue is deleted.1363	 */1364	list_for_each_entry_safe(obj, obj_safe, &req->objects, list)1365		if (obj->ops->queue)1366			obj->ops->queue(obj);1367}1368EXPORT_SYMBOL_GPL(vb2_request_queue);1369 1370MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");1371MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");1372MODULE_LICENSE("GPL");1373