Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3082 insertions, 0 deletions

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
new file mode 100644
index 000000000..92efc4676
--- /dev/null
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -0,0 +1,3082 @@
+/*
+ * videobuf2-core.c - video buffer 2 core framework
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <pawel@osciak.com>
+ *	   Marek Szyprowski <m.szyprowski@samsung.com>
+ *
+ * The vb2_thread implementation was based on code from videobuf-dvb.c:
+ *	(c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+
+#include <media/videobuf2-core.h>
+#include <media/v4l2-mc.h>
+
+#include <trace/events/vb2.h>
+
+static int debug;
+module_param(debug, int, 0644);
+
+#define dprintk(q, level, fmt, arg...)					\
+	do {								\
+		if (debug >= level)					\
+			pr_info("[%s] %s: " fmt, (q)->name, __func__,	\
+				## arg);				\
+	} while (0)
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+
+/*
+ * If advanced debugging is on, then count how often each op is called
+ * successfully, which can either be per-buffer or per-queue.
+ *
+ * This makes it easy to check that the 'init' and 'cleanup'
+ * (and variations thereof) stay balanced.
+ */
+
+#define log_memop(vb, op)						\
+	dprintk((vb)->vb2_queue, 2, "call_memop(%d, %s)%s\n",		\
+		(vb)->index, #op,					\
+		(vb)->vb2_queue->mem_ops->op ? "" : " (nop)")
+
+#define call_memop(vb, op, args...)					\
+({									\
+	struct vb2_queue *_q = (vb)->vb2_queue;				\
+	int err;							\
+									\
+	log_memop(vb, op);						\
+	err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0;		\
+	if (!err)							\
+		(vb)->cnt_mem_ ## op++;					\
+	err;								\
+})
+
+#define call_ptr_memop(op, vb, args...)					\
+({									\
+	struct vb2_queue *_q = (vb)->vb2_queue;				\
+	void *ptr;							\
+									\
+	log_memop(vb, op);						\
+	ptr = _q->mem_ops->op ? _q->mem_ops->op(vb, args) : NULL;	\
+	if (!IS_ERR_OR_NULL(ptr))					\
+		(vb)->cnt_mem_ ## op++;					\
+	ptr;								\
+})
+
+#define call_void_memop(vb, op, args...)				\
+({									\
+	struct vb2_queue *_q = (vb)->vb2_queue;				\
+									\
+	log_memop(vb, op);						\
+	if (_q->mem_ops->op)						\
+		_q->mem_ops->op(args);					\
+	(vb)->cnt_mem_ ## op++;						\
+})
+
+#define log_qop(q, op)							\
+	dprintk(q, 2, "call_qop(%s)%s\n", #op,				\
+		(q)->ops->op ? "" : " (nop)")
+
+#define call_qop(q, op, args...)					\
+({									\
+	int err;							\
+									\
+	log_qop(q, op);							\
+	err = (q)->ops->op ? (q)->ops->op(args) : 0;			\
+	if (!err)							\
+		(q)->cnt_ ## op++;					\
+	err;								\
+})
+
+#define call_void_qop(q, op, args...)					\
+({									\
+	log_qop(q, op);							\
+	if ((q)->ops->op)						\
+		(q)->ops->op(args);					\
+	(q)->cnt_ ## op++;						\
+})
+
+#define log_vb_qop(vb, op, args...)					\
+	dprintk((vb)->vb2_queue, 2, "call_vb_qop(%d, %s)%s\n",		\
+		(vb)->index, #op,					\
+		(vb)->vb2_queue->ops->op ? "" : " (nop)")
+
+#define call_vb_qop(vb, op, args...)					\
+({									\
+	int err;							\
+									\
+	log_vb_qop(vb, op);						\
+	err = (vb)->vb2_queue->ops->op ?				\
+		(vb)->vb2_queue->ops->op(args) : 0;			\
+	if (!err)							\
+		(vb)->cnt_ ## op++;					\
+	err;								\
+})
+
+#define call_void_vb_qop(vb, op, args...)				\
+({									\
+	log_vb_qop(vb, op);						\
+	if ((vb)->vb2_queue->ops->op)					\
+		(vb)->vb2_queue->ops->op(args);				\
+	(vb)->cnt_ ## op++;						\
+})
+
+#else
+
+#define call_memop(vb, op, args...)					\
+	((vb)->vb2_queue->mem_ops->op ?					\
+		(vb)->vb2_queue->mem_ops->op(args) : 0)
+
+#define call_ptr_memop(op, vb, args...)					\
+	((vb)->vb2_queue->mem_ops->op ?					\
+		(vb)->vb2_queue->mem_ops->op(vb, args) : NULL)
+
+#define call_void_memop(vb, op, args...)				\
+	do {								\
+		if ((vb)->vb2_queue->mem_ops->op)			\
+			(vb)->vb2_queue->mem_ops->op(args);		\
+	} while (0)
+
+#define call_qop(q, op, args...)					\
+	((q)->ops->op ? (q)->ops->op(args) : 0)
+
+#define call_void_qop(q, op, args...)					\
+	do {								\
+		if ((q)->ops->op)					\
+			(q)->ops->op(args);				\
+	} while (0)
+
+#define call_vb_qop(vb, op, args...)					\
+	((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0)
+
+#define call_void_vb_qop(vb, op, args...)				\
+	do {								\
+		if ((vb)->vb2_queue->ops->op)				\
+			(vb)->vb2_queue->ops->op(args);			\
+	} while (0)
+
+#endif
+
+#define call_bufop(q, op, args...)					\
+({									\
+	int ret = 0;							\
+	if (q && q->buf_ops && q->buf_ops->op)				\
+		ret = q->buf_ops->op(args);				\
+	ret;								\
+})
+
+#define call_void_bufop(q, op, args...)					\
+({									\
+	if (q && q->buf_ops && q->buf_ops->op)				\
+		q->buf_ops->op(args);					\
+})
+
+static void __vb2_queue_cancel(struct vb2_queue *q);
+static void __enqueue_in_driver(struct vb2_buffer *vb);
+
+static const char *vb2_state_name(enum vb2_buffer_state s)
+{
+	static const char * const state_names[] = {
+		[VB2_BUF_STATE_DEQUEUED] = "dequeued",
+		[VB2_BUF_STATE_IN_REQUEST] = "in request",
+		[VB2_BUF_STATE_PREPARING] = "preparing",
+		[VB2_BUF_STATE_QUEUED] = "queued",
+		[VB2_BUF_STATE_ACTIVE] = "active",
+		[VB2_BUF_STATE_DONE] = "done",
+		[VB2_BUF_STATE_ERROR] = "error",
+	};
+
+	if ((unsigned int)(s) < ARRAY_SIZE(state_names))
+		return state_names[s];
+	return "unknown";
+}
+
+/*
+ * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
+ */
+static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
+{
+	struct vb2_queue *q = vb->vb2_queue;
+	void *mem_priv;
+	int plane;
+	int ret = -ENOMEM;
+
+	/*
+	 * Allocate memory for all planes in this buffer
+	 * NOTE: mmapped areas should be page aligned
+	 */
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		/* Memops alloc requires size to be page aligned. */
+		unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
+
+		/* Did it wrap around? */
+		if (size < vb->planes[plane].length)
+			goto free;
+
+		mem_priv = call_ptr_memop(alloc,
+					  vb,
+					  q->alloc_devs[plane] ? : q->dev,
+					  size);
+		if (IS_ERR_OR_NULL(mem_priv)) {
+			if (mem_priv)
+				ret = PTR_ERR(mem_priv);
+			goto free;
+		}
+
+		/* Associate allocator private data with this plane */
+		vb->planes[plane].mem_priv = mem_priv;
+	}
+
+	return 0;
+free:
+	/* Free already allocated memory if one of the allocations failed */
+	for (; plane > 0; --plane) {
+		call_void_memop(vb, put, vb->planes[plane - 1].mem_priv);
+		vb->planes[plane - 1].mem_priv = NULL;
+	}
+
+	return ret;
+}
+
+/*
+ * __vb2_buf_mem_free() - free memory of the given buffer
+ */
+static void __vb2_buf_mem_free(struct vb2_buffer *vb)
+{
+	unsigned int plane;
+
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		call_void_memop(vb, put, vb->planes[plane].mem_priv);
+		vb->planes[plane].mem_priv = NULL;
+		dprintk(vb->vb2_queue, 3, "freed plane %d of buffer %d\n",
+			plane, vb->index);
+	}
+}
+
+/*
+ * __vb2_buf_userptr_put() - release userspace memory associated with
+ * a USERPTR buffer
+ */
+static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
+{
+	unsigned int plane;
+
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		if (vb->planes[plane].mem_priv)
+			call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
+		vb->planes[plane].mem_priv = NULL;
+	}
+}
+
+/*
+ * __vb2_plane_dmabuf_put() - release memory associated with
+ * a DMABUF shared plane
+ */
+static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
+{
+	if (!p->mem_priv)
+		return;
+
+	if (p->dbuf_mapped)
+		call_void_memop(vb, unmap_dmabuf, p->mem_priv);
+
+	call_void_memop(vb, detach_dmabuf, p->mem_priv);
+	dma_buf_put(p->dbuf);
+	p->mem_priv = NULL;
+	p->dbuf = NULL;
+	p->dbuf_mapped = 0;
+}
+
+/*
+ * __vb2_buf_dmabuf_put() - release memory associated with
+ * a DMABUF shared buffer
+ */
+static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
+{
+	unsigned int plane;
+
+	for (plane = 0; plane < vb->num_planes; ++plane)
+		__vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
+}
+
+/*
+ * __vb2_buf_mem_prepare() - call ->prepare() on buffer's private memory
+ * to sync caches
+ */
+static void __vb2_buf_mem_prepare(struct vb2_buffer *vb)
+{
+	unsigned int plane;
+
+	if (vb->synced)
+		return;
+
+	vb->synced = 1;
+	for (plane = 0; plane < vb->num_planes; ++plane)
+		call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
+}
+
+/*
+ * __vb2_buf_mem_finish() - call ->finish on buffer's private memory
+ * to sync caches
+ */
+static void __vb2_buf_mem_finish(struct vb2_buffer *vb)
+{
+	unsigned int plane;
+
+	if (!vb->synced)
+		return;
+
+	vb->synced = 0;
+	for (plane = 0; plane < vb->num_planes; ++plane)
+		call_void_memop(vb, finish, vb->planes[plane].mem_priv);
+}
+
+/*
+ * __setup_offsets() - setup unique offsets ("cookies") for every plane in
+ * the buffer.
+ */
+static void __setup_offsets(struct vb2_buffer *vb)
+{
+	struct vb2_queue *q = vb->vb2_queue;
+	unsigned int plane;
+	unsigned long off = 0;
+
+	if (vb->index) {
+		struct vb2_buffer *prev = q->bufs[vb->index - 1];
+		struct vb2_plane *p = &prev->planes[prev->num_planes - 1];
+
+		off = PAGE_ALIGN(p->m.offset + p->length);
+	}
+
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		vb->planes[plane].m.offset = off;
+
+		dprintk(q, 3, "buffer %d, plane %d offset 0x%08lx\n",
+				vb->index, plane, off);
+
+		off += vb->planes[plane].length;
+		off = PAGE_ALIGN(off);
+	}
+}
+
+static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
+{
+	/*
+	 * DMA exporter should take care of cache syncs, so we can avoid
+	 * explicit ->prepare()/->finish() syncs. For other ->memory types
+	 * we always need ->prepare() or/and ->finish() cache sync.
+	 */
+	if (q->memory == VB2_MEMORY_DMABUF) {
+		vb->skip_cache_sync_on_finish = 1;
+		vb->skip_cache_sync_on_prepare = 1;
+		return;
+	}
+
+	/*
+	 * ->finish() cache sync can be avoided when queue direction is
+	 * TO_DEVICE.
+	 */
+	if (q->dma_dir == DMA_TO_DEVICE)
+		vb->skip_cache_sync_on_finish = 1;
+}
+
+/*
+ * __vb2_queue_alloc() - allocate vb2 buffer structures and (for MMAP type)
+ * video buffer memory for all buffers/planes on the queue and initializes the
+ * queue
+ *
+ * Returns the number of buffers successfully allocated.
+ */
+static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
+			     unsigned int num_buffers, unsigned int num_planes,
+			     const unsigned plane_sizes[VB2_MAX_PLANES])
+{
+	unsigned int buffer, plane;
+	struct vb2_buffer *vb;
+	int ret;
+
+	/* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
+	num_buffers = min_t(unsigned int, num_buffers,
+			    VB2_MAX_FRAME - q->num_buffers);
+
+	for (buffer = 0; buffer < num_buffers; ++buffer) {
+		/* Allocate vb2 buffer structures */
+		vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
+		if (!vb) {
+			dprintk(q, 1, "memory alloc for buffer struct failed\n");
+			break;
+		}
+
+		vb->state = VB2_BUF_STATE_DEQUEUED;
+		vb->vb2_queue = q;
+		vb->num_planes = num_planes;
+		vb->index = q->num_buffers + buffer;
+		vb->type = q->type;
+		vb->memory = memory;
+		init_buffer_cache_hints(q, vb);
+		for (plane = 0; plane < num_planes; ++plane) {
+			vb->planes[plane].length = plane_sizes[plane];
+			vb->planes[plane].min_length = plane_sizes[plane];
+		}
+		call_void_bufop(q, init_buffer, vb);
+
+		q->bufs[vb->index] = vb;
+
+		/* Allocate video buffer memory for the MMAP type */
+		if (memory == VB2_MEMORY_MMAP) {
+			ret = __vb2_buf_mem_alloc(vb);
+			if (ret) {
+				dprintk(q, 1, "failed allocating memory for buffer %d\n",
+					buffer);
+				q->bufs[vb->index] = NULL;
+				kfree(vb);
+				break;
+			}
+			__setup_offsets(vb);
+			/*
+			 * Call the driver-provided buffer initialization
+			 * callback, if given. An error in initialization
+			 * results in queue setup failure.
+			 */
+			ret = call_vb_qop(vb, buf_init, vb);
+			if (ret) {
+				dprintk(q, 1, "buffer %d %p initialization failed\n",
+					buffer, vb);
+				__vb2_buf_mem_free(vb);
+				q->bufs[vb->index] = NULL;
+				kfree(vb);
+				break;
+			}
+		}
+	}
+
+	dprintk(q, 3, "allocated %d buffers, %d plane(s) each\n",
+		buffer, num_planes);
+
+	return buffer;
+}
+
+/*
+ * __vb2_free_mem() - release all video buffer memory for a given queue
+ */
+static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
+{
+	unsigned int buffer;
+	struct vb2_buffer *vb;
+
+	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+	     ++buffer) {
+		vb = q->bufs[buffer];
+		if (!vb)
+			continue;
+
+		/* Free MMAP buffers or release USERPTR buffers */
+		if (q->memory == VB2_MEMORY_MMAP)
+			__vb2_buf_mem_free(vb);
+		else if (q->memory == VB2_MEMORY_DMABUF)
+			__vb2_buf_dmabuf_put(vb);
+		else
+			__vb2_buf_userptr_put(vb);
+	}
+}
+
+/*
+ * __vb2_queue_free() - free buffers at the end of the queue - video memory and
+ * related information, if no buffers are left return the queue to an
+ * uninitialized state. Might be called even if the queue has already been freed.
+ */
+static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
+{
+	unsigned int buffer;
+
+	/*
+	 * Sanity check: when preparing a buffer the queue lock is released for
+	 * a short while (see __buf_prepare for the details), which would allow
+	 * a race with a reqbufs which can call this function. Removing the
+	 * buffers from underneath __buf_prepare is obviously a bad idea, so we
+	 * check if any of the buffers is in the state PREPARING, and if so we
+	 * just return -EAGAIN.
+	 */
+	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+	     ++buffer) {
+		if (q->bufs[buffer] == NULL)
+			continue;
+		if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
+			dprintk(q, 1, "preparing buffers, cannot free\n");
+			return -EAGAIN;
+		}
+	}
+
+	/* Call driver-provided cleanup function for each buffer, if provided */
+	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+	     ++buffer) {
+		struct vb2_buffer *vb = q->bufs[buffer];
+
+		if (vb && vb->planes[0].mem_priv)
+			call_void_vb_qop(vb, buf_cleanup, vb);
+	}
+
+	/* Release video buffer memory */
+	__vb2_free_mem(q, buffers);
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	/*
+	 * Check that all the calls were balances during the life-time of this
+	 * queue. If not (or if the debug level is 1 or up), then dump the
+	 * counters to the kernel log.
+	 */
+	if (q->num_buffers) {
+		bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming ||
+				  q->cnt_wait_prepare != q->cnt_wait_finish;
+
+		if (unbalanced || debug) {
+			pr_info("counters for queue %p:%s\n", q,
+				unbalanced ? " UNBALANCED!" : "");
+			pr_info("     setup: %u start_streaming: %u stop_streaming: %u\n",
+				q->cnt_queue_setup, q->cnt_start_streaming,
+				q->cnt_stop_streaming);
+			pr_info("     wait_prepare: %u wait_finish: %u\n",
+				q->cnt_wait_prepare, q->cnt_wait_finish);
+		}
+		q->cnt_queue_setup = 0;
+		q->cnt_wait_prepare = 0;
+		q->cnt_wait_finish = 0;
+		q->cnt_start_streaming = 0;
+		q->cnt_stop_streaming = 0;
+	}
+	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+		struct vb2_buffer *vb = q->bufs[buffer];
+		bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
+				  vb->cnt_mem_prepare != vb->cnt_mem_finish ||
+				  vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
+				  vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
+				  vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
+				  vb->cnt_buf_queue != vb->cnt_buf_done ||
+				  vb->cnt_buf_prepare != vb->cnt_buf_finish ||
+				  vb->cnt_buf_init != vb->cnt_buf_cleanup;
+
+		if (unbalanced || debug) {
+			pr_info("   counters for queue %p, buffer %d:%s\n",
+				q, buffer, unbalanced ? " UNBALANCED!" : "");
+			pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
+				vb->cnt_buf_init, vb->cnt_buf_cleanup,
+				vb->cnt_buf_prepare, vb->cnt_buf_finish);
+			pr_info("     buf_out_validate: %u buf_queue: %u buf_done: %u buf_request_complete: %u\n",
+				vb->cnt_buf_out_validate, vb->cnt_buf_queue,
+				vb->cnt_buf_done, vb->cnt_buf_request_complete);
+			pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
+				vb->cnt_mem_alloc, vb->cnt_mem_put,
+				vb->cnt_mem_prepare, vb->cnt_mem_finish,
+				vb->cnt_mem_mmap);
+			pr_info("     get_userptr: %u put_userptr: %u\n",
+				vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr);
+			pr_info("     attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n",
+				vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf,
+				vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf);
+			pr_info("     get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n",
+				vb->cnt_mem_get_dmabuf,
+				vb->cnt_mem_num_users,
+				vb->cnt_mem_vaddr,
+				vb->cnt_mem_cookie);
+		}
+	}
+#endif
+
+	/* Free vb2 buffers */
+	for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+	     ++buffer) {
+		kfree(q->bufs[buffer]);
+		q->bufs[buffer] = NULL;
+	}
+
+	q->num_buffers -= buffers;
+	if (!q->num_buffers) {
+		q->memory = VB2_MEMORY_UNKNOWN;
+		INIT_LIST_HEAD(&q->queued_list);
+	}
+	return 0;
+}
+
+bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
+{
+	unsigned int plane;
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		void *mem_priv = vb->planes[plane].mem_priv;
+		/*
+		 * If num_users() has not been provided, call_memop
+		 * will return 0, apparently nobody cares about this
+		 * case anyway. If num_users() returns more than 1,
+		 * we are not the only user of the plane's memory.
+		 */
+		if (mem_priv && call_memop(vb, num_users, mem_priv) > 1)
+			return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL(vb2_buffer_in_use);
+
+/*
+ * __buffers_in_use() - return true if any buffers on the queue are in use and
+ * the queue cannot be freed (by the means of REQBUFS(0)) call
+ */
+static bool __buffers_in_use(struct vb2_queue *q)
+{
+	unsigned int buffer;
+	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+		if (vb2_buffer_in_use(q, q->bufs[buffer]))
+			return true;
+	}
+	return false;
+}
+
+void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
+{
+	call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
+}
+EXPORT_SYMBOL_GPL(vb2_core_querybuf);
+
+/*
+ * __verify_userptr_ops() - verify that all memory operations required for
+ * USERPTR queue type have been provided
+ */
+static int __verify_userptr_ops(struct vb2_queue *q)
+{
+	if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
+	    !q->mem_ops->put_userptr)
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * __verify_mmap_ops() - verify that all memory operations required for
+ * MMAP queue type have been provided
+ */
+static int __verify_mmap_ops(struct vb2_queue *q)
+{
+	if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
+	    !q->mem_ops->put || !q->mem_ops->mmap)
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * __verify_dmabuf_ops() - verify that all memory operations required for
+ * DMABUF queue type have been provided
+ */
+static int __verify_dmabuf_ops(struct vb2_queue *q)
+{
+	if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
+	    !q->mem_ops->detach_dmabuf  || !q->mem_ops->map_dmabuf ||
+	    !q->mem_ops->unmap_dmabuf)
+		return -EINVAL;
+
+	return 0;
+}
+
+int vb2_verify_memory_type(struct vb2_queue *q,
+		enum vb2_memory memory, unsigned int type)
+{
+	if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR &&
+	    memory != VB2_MEMORY_DMABUF) {
+		dprintk(q, 1, "unsupported memory type\n");
+		return -EINVAL;
+	}
+
+	if (type != q->type) {
+		dprintk(q, 1, "requested type is incorrect\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Make sure all the required memory ops for given memory type
+	 * are available.
+	 */
+	if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) {
+		dprintk(q, 1, "MMAP for current setup unsupported\n");
+		return -EINVAL;
+	}
+
+	if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
+		dprintk(q, 1, "USERPTR for current setup unsupported\n");
+		return -EINVAL;
+	}
+
+	if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
+		dprintk(q, 1, "DMABUF for current setup unsupported\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Place the busy tests at the end: -EBUSY can be ignored when
+	 * create_bufs is called with count == 0, but count == 0 should still
+	 * do the memory and type validation.
+	 */
+	if (vb2_fileio_is_active(q)) {
+		dprintk(q, 1, "file io in progress\n");
+		return -EBUSY;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(vb2_verify_memory_type);
+
+static void set_queue_coherency(struct vb2_queue *q, bool non_coherent_mem)
+{
+	q->non_coherent_mem = 0;
+
+	if (!vb2_queue_allows_cache_hints(q))
+		return;
+	q->non_coherent_mem = non_coherent_mem;
+}
+
+static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
+{
+	if (non_coherent_mem != q->non_coherent_mem) {
+		dprintk(q, 1, "memory coherency model mismatch\n");
+		return false;
+	}
+	return true;
+}
+
+int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
+		     unsigned int flags, unsigned int *count)
+{
+	unsigned int num_buffers, allocated_buffers, num_planes = 0;
+	unsigned plane_sizes[VB2_MAX_PLANES] = { };
+	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
+	unsigned int i;
+	int ret;
+
+	if (q->streaming) {
+		dprintk(q, 1, "streaming active\n");
+		return -EBUSY;
+	}
+
+	if (q->waiting_in_dqbuf && *count) {
+		dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
+		return -EBUSY;
+	}
+
+	if (*count == 0 || q->num_buffers != 0 ||
+	    (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) ||
+	    !verify_coherency_flags(q, non_coherent_mem)) {
+		/*
+		 * We already have buffers allocated, so first check if they
+		 * are not in use and can be freed.
+		 */
+		mutex_lock(&q->mmap_lock);
+		if (debug && q->memory == VB2_MEMORY_MMAP &&
+		    __buffers_in_use(q))
+			dprintk(q, 1, "memory in use, orphaning buffers\n");
+
+		/*
+		 * Call queue_cancel to clean up any buffers in the
+		 * QUEUED state which is possible if buffers were prepared or
+		 * queued without ever calling STREAMON.
+		 */
+		__vb2_queue_cancel(q);
+		ret = __vb2_queue_free(q, q->num_buffers);
+		mutex_unlock(&q->mmap_lock);
+		if (ret)
+			return ret;
+
+		/*
+		 * In case of REQBUFS(0) return immediately without calling
+		 * driver's queue_setup() callback and allocating resources.
+		 */
+		if (*count == 0)
+			return 0;
+	}
+
+	/*
+	 * Make sure the requested values and current defaults are sane.
+	 */
+	WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
+	num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
+	num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
+	memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
+	/*
+	 * Set this now to ensure that drivers see the correct q->memory value
+	 * in the queue_setup op.
+	 */
+	mutex_lock(&q->mmap_lock);
+	q->memory = memory;
+	mutex_unlock(&q->mmap_lock);
+	set_queue_coherency(q, non_coherent_mem);
+
+	/*
+	 * Ask the driver how many buffers and planes per buffer it requires.
+	 * Driver also sets the size and allocator context for each plane.
+	 */
+	ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
+		       plane_sizes, q->alloc_devs);
+	if (ret)
+		goto error;
+
+	/* Check that driver has set sane values */
+	if (WARN_ON(!num_planes)) {
+		ret = -EINVAL;
+		goto error;
+	}
+
+	for (i = 0; i < num_planes; i++)
+		if (WARN_ON(!plane_sizes[i])) {
+			ret = -EINVAL;
+			goto error;
+		}
+
+	/* Finally, allocate buffers and video memory */
+	allocated_buffers =
+		__vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);
+	if (allocated_buffers == 0) {
+		dprintk(q, 1, "memory allocation failed\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/*
+	 * There is no point in continuing if we can't allocate the minimum
+	 * number of buffers needed by this vb2_queue.
+	 */
+	if (allocated_buffers < q->min_buffers_needed)
+		ret = -ENOMEM;
+
+	/*
+	 * Check if driver can handle the allocated number of buffers.
+	 */
+	if (!ret && allocated_buffers < num_buffers) {
+		num_buffers = allocated_buffers;
+		/*
+		 * num_planes is set by the previous queue_setup(), but since it
+		 * signals to queue_setup() whether it is called from create_bufs()
+		 * vs reqbufs() we zero it here to signal that queue_setup() is
+		 * called for the reqbufs() case.
+		 */
+		num_planes = 0;
+
+		ret = call_qop(q, queue_setup, q, &num_buffers,
+			       &num_planes, plane_sizes, q->alloc_devs);
+
+		if (!ret && allocated_buffers < num_buffers)
+			ret = -ENOMEM;
+
+		/*
+		 * Either the driver has accepted a smaller number of buffers,
+		 * or .queue_setup() returned an error
+		 */
+	}
+
+	mutex_lock(&q->mmap_lock);
+	q->num_buffers = allocated_buffers;
+
+	if (ret < 0) {
+		/*
+		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
+		 * from q->num_buffers and it will reset q->memory to
+		 * VB2_MEMORY_UNKNOWN.
+		 */
+		__vb2_queue_free(q, allocated_buffers);
+		mutex_unlock(&q->mmap_lock);
+		return ret;
+	}
+	mutex_unlock(&q->mmap_lock);
+
+	/*
+	 * Return the number of successfully allocated buffers
+	 * to the userspace.
+	 */
+	*count = allocated_buffers;
+	q->waiting_for_buffers = !q->is_output;
+
+	return 0;
+
+error:
+	mutex_lock(&q->mmap_lock);
+	q->memory = VB2_MEMORY_UNKNOWN;
+	mutex_unlock(&q->mmap_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
+
+int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
+			 unsigned int flags, unsigned int *count,
+			 unsigned int requested_planes,
+			 const unsigned int requested_sizes[])
+{
+	unsigned int num_planes = 0, num_buffers, allocated_buffers;
+	unsigned plane_sizes[VB2_MAX_PLANES] = { };
+	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
+	bool no_previous_buffers = !q->num_buffers;
+	int ret;
+
+	if (q->num_buffers == VB2_MAX_FRAME) {
+		dprintk(q, 1, "maximum number of buffers already allocated\n");
+		return -ENOBUFS;
+	}
+
+	if (no_previous_buffers) {
+		if (q->waiting_in_dqbuf && *count) {
+			dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
+			return -EBUSY;
+		}
+		memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
+		/*
+		 * Set this now to ensure that drivers see the correct q->memory
+		 * value in the queue_setup op.
+		 */
+		mutex_lock(&q->mmap_lock);
+		q->memory = memory;
+		mutex_unlock(&q->mmap_lock);
+		q->waiting_for_buffers = !q->is_output;
+		set_queue_coherency(q, non_coherent_mem);
+	} else {
+		if (q->memory != memory) {
+			dprintk(q, 1, "memory model mismatch\n");
+			return -EINVAL;
+		}
+		if (!verify_coherency_flags(q, non_coherent_mem))
+			return -EINVAL;
+	}
+
+	num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
+
+	if (requested_planes && requested_sizes) {
+		num_planes = requested_planes;
+		memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes));
+	}
+
+	/*
+	 * Ask the driver, whether the requested number of buffers, planes per
+	 * buffer and their sizes are acceptable
+	 */
+	ret = call_qop(q, queue_setup, q, &num_buffers,
+		       &num_planes, plane_sizes, q->alloc_devs);
+	if (ret)
+		goto error;
+
+	/* Finally, allocate buffers and video memory */
+	allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
+				num_planes, plane_sizes);
+	if (allocated_buffers == 0) {
+		dprintk(q, 1, "memory allocation failed\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/*
+	 * Check if driver can handle the so far allocated number of buffers.
+	 */
+	if (allocated_buffers < num_buffers) {
+		num_buffers = allocated_buffers;
+
+		/*
+		 * q->num_buffers contains the total number of buffers, that the
+		 * queue driver has set up
+		 */
+		ret = call_qop(q, queue_setup, q, &num_buffers,
+			       &num_planes, plane_sizes, q->alloc_devs);
+
+		if (!ret && allocated_buffers < num_buffers)
+			ret = -ENOMEM;
+
+		/*
+		 * Either the driver has accepted a smaller number of buffers,
+		 * or .queue_setup() returned an error
+		 */
+	}
+
+	mutex_lock(&q->mmap_lock);
+	q->num_buffers += allocated_buffers;
+
+	if (ret < 0) {
+		/*
+		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'
+		 * from q->num_buffers and it will reset q->memory to
+		 * VB2_MEMORY_UNKNOWN.
+		 */
+		__vb2_queue_free(q, allocated_buffers);
+		mutex_unlock(&q->mmap_lock);
+		return -ENOMEM;
+	}
+	mutex_unlock(&q->mmap_lock);
+
+	/*
+	 * Return the number of successfully allocated buffers
+	 * to the userspace.
+	 */
+	*count = allocated_buffers;
+
+	return 0;
+
+error:
+	if (no_previous_buffers) {
+		mutex_lock(&q->mmap_lock);
+		q->memory = VB2_MEMORY_UNKNOWN;
+		mutex_unlock(&q->mmap_lock);
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
+
+void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
+{
+	if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
+		return NULL;
+
+	return call_ptr_memop(vaddr, vb, vb->planes[plane_no].mem_priv);
+
+}
+EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
+
+void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
+{
+	if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv)
+		return NULL;
+
+	return call_ptr_memop(cookie, vb, vb->planes[plane_no].mem_priv);
+}
+EXPORT_SYMBOL_GPL(vb2_plane_cookie);
+
+void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
+{
+	struct vb2_queue *q = vb->vb2_queue;
+	unsigned long flags;
+
+	if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
+		return;
+
+	if (WARN_ON(state != VB2_BUF_STATE_DONE &&
+		    state != VB2_BUF_STATE_ERROR &&
+		    state != VB2_BUF_STATE_QUEUED))
+		state = VB2_BUF_STATE_ERROR;
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	/*
+	 * Although this is not a callback, it still does have to balance
+	 * with the buf_queue op. So update this counter manually.
+	 */
+	vb->cnt_buf_done++;
+#endif
+	dprintk(q, 4, "done processing on buffer %d, state: %s\n",
+		vb->index, vb2_state_name(state));
+
+	if (state != VB2_BUF_STATE_QUEUED)
+		__vb2_buf_mem_finish(vb);
+
+	spin_lock_irqsave(&q->done_lock, flags);
+	if (state == VB2_BUF_STATE_QUEUED) {
+		vb->state = VB2_BUF_STATE_QUEUED;
+	} else {
+		/* Add the buffer to the done buffers list */
+		list_add_tail(&vb->done_entry, &q->done_list);
+		vb->state = state;
+	}
+	atomic_dec(&q->owned_by_drv_count);
+
+	if (state != VB2_BUF_STATE_QUEUED && vb->req_obj.req) {
+		media_request_object_unbind(&vb->req_obj);
+		media_request_object_put(&vb->req_obj);
+	}
+
+	spin_unlock_irqrestore(&q->done_lock, flags);
+
+	trace_vb2_buf_done(q, vb);
+
+	switch (state) {
+	case VB2_BUF_STATE_QUEUED:
+		return;
+	default:
+		/* Inform any processes that may be waiting for buffers */
+		wake_up(&q->done_wq);
+		break;
+	}
+}
+EXPORT_SYMBOL_GPL(vb2_buffer_done);
+
+void vb2_discard_done(struct vb2_queue *q)
+{
+	struct vb2_buffer *vb;
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->done_lock, flags);
+	list_for_each_entry(vb, &q->done_list, done_entry)
+		vb->state = VB2_BUF_STATE_ERROR;
+	spin_unlock_irqrestore(&q->done_lock, flags);
+}
+EXPORT_SYMBOL_GPL(vb2_discard_done);
+
+/*
+ * __prepare_mmap() - prepare an MMAP buffer
+ */
+static int __prepare_mmap(struct vb2_buffer *vb)
+{
+	int ret = 0;
+
+	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
+			 vb, vb->planes);
+	return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
+}
+
+/*
+ * __prepare_userptr() - prepare a USERPTR buffer
+ */
+static int __prepare_userptr(struct vb2_buffer *vb)
+{
+	struct vb2_plane planes[VB2_MAX_PLANES];
+	struct vb2_queue *q = vb->vb2_queue;
+	void *mem_priv;
+	unsigned int plane;
+	int ret = 0;
+	bool reacquired = vb->planes[0].mem_priv == NULL;
+
+	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
+	/* Copy relevant information provided by the userspace */
+	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
+			 vb, planes);
+	if (ret)
+		return ret;
+
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		/* Skip the plane if already verified */
+		if (vb->planes[plane].m.userptr &&
+			vb->planes[plane].m.userptr == planes[plane].m.userptr
+			&& vb->planes[plane].length == planes[plane].length)
+			continue;
+
+		dprintk(q, 3, "userspace address for plane %d changed, reacquiring memory\n",
+			plane);
+
+		/* Check if the provided plane buffer is large enough */
+		if (planes[plane].length < vb->planes[plane].min_length) {
+			dprintk(q, 1, "provided buffer size %u is less than setup size %u for plane %d\n",
+						planes[plane].length,
+						vb->planes[plane].min_length,
+						plane);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		/* Release previously acquired memory if present */
+		if (vb->planes[plane].mem_priv) {
+			if (!reacquired) {
+				reacquired = true;
+				vb->copied_timestamp = 0;
+				call_void_vb_qop(vb, buf_cleanup, vb);
+			}
+			call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv);
+		}
+
+		vb->planes[plane].mem_priv = NULL;
+		vb->planes[plane].bytesused = 0;
+		vb->planes[plane].length = 0;
+		vb->planes[plane].m.userptr = 0;
+		vb->planes[plane].data_offset = 0;
+
+		/* Acquire each plane's memory */
+		mem_priv = call_ptr_memop(get_userptr,
+					  vb,
+					  q->alloc_devs[plane] ? : q->dev,
+					  planes[plane].m.userptr,
+					  planes[plane].length);
+		if (IS_ERR(mem_priv)) {
+			dprintk(q, 1, "failed acquiring userspace memory for plane %d\n",
+				plane);
+			ret = PTR_ERR(mem_priv);
+			goto err;
+		}
+		vb->planes[plane].mem_priv = mem_priv;
+	}
+
+	/*
+	 * Now that everything is in order, copy relevant information
+	 * provided by userspace.
+	 */
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		vb->planes[plane].bytesused = planes[plane].bytesused;
+		vb->planes[plane].length = planes[plane].length;
+		vb->planes[plane].m.userptr = planes[plane].m.userptr;
+		vb->planes[plane].data_offset = planes[plane].data_offset;
+	}
+
+	if (reacquired) {
+		/*
+		 * One or more planes changed, so we must call buf_init to do
+		 * the driver-specific initialization on the newly acquired
+		 * buffer, if provided.
+		 */
+		ret = call_vb_qop(vb, buf_init, vb);
+		if (ret) {
+			dprintk(q, 1, "buffer initialization failed\n");
+			goto err;
+		}
+	}
+
+	ret = call_vb_qop(vb, buf_prepare, vb);
+	if (ret) {
+		dprintk(q, 1, "buffer preparation failed\n");
+		call_void_vb_qop(vb, buf_cleanup, vb);
+		goto err;
+	}
+
+	return 0;
+err:
+	/* In case of errors, release planes that were already acquired */
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		if (vb->planes[plane].mem_priv)
+			call_void_memop(vb, put_userptr,
+				vb->planes[plane].mem_priv);
+		vb->planes[plane].mem_priv = NULL;
+		vb->planes[plane].m.userptr = 0;
+		vb->planes[plane].length = 0;
+	}
+
+	return ret;
+}
+
+/*
+ * __prepare_dmabuf() - prepare a DMABUF buffer
+ */
+static int __prepare_dmabuf(struct vb2_buffer *vb)
+{
+	struct vb2_plane planes[VB2_MAX_PLANES];
+	struct vb2_queue *q = vb->vb2_queue;
+	void *mem_priv;
+	unsigned int plane;
+	int ret = 0;
+	bool reacquired = vb->planes[0].mem_priv == NULL;
+
+	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
+	/* Copy relevant information provided by the userspace */
+	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
+			 vb, planes);
+	if (ret)
+		return ret;
+
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
+
+		if (IS_ERR_OR_NULL(dbuf)) {
+			dprintk(q, 1, "invalid dmabuf fd for plane %d\n",
+				plane);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		/* use DMABUF size if length is not provided */
+		if (planes[plane].length == 0)
+			planes[plane].length = dbuf->size;
+
+		if (planes[plane].length < vb->planes[plane].min_length) {
+			dprintk(q, 1, "invalid dmabuf length %u for plane %d, minimum length %u\n",
+				planes[plane].length, plane,
+				vb->planes[plane].min_length);
+			dma_buf_put(dbuf);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		/* Skip the plane if already verified */
+		if (dbuf == vb->planes[plane].dbuf &&
+			vb->planes[plane].length == planes[plane].length) {
+			dma_buf_put(dbuf);
+			continue;
+		}
+
+		dprintk(q, 3, "buffer for plane %d changed\n", plane);
+
+		if (!reacquired) {
+			reacquired = true;
+			vb->copied_timestamp = 0;
+			call_void_vb_qop(vb, buf_cleanup, vb);
+		}
+
+		/* Release previously acquired memory if present */
+		__vb2_plane_dmabuf_put(vb, &vb->planes[plane]);
+		vb->planes[plane].bytesused = 0;
+		vb->planes[plane].length = 0;
+		vb->planes[plane].m.fd = 0;
+		vb->planes[plane].data_offset = 0;
+
+		/* Acquire each plane's memory */
+		mem_priv = call_ptr_memop(attach_dmabuf,
+					  vb,
+					  q->alloc_devs[plane] ? : q->dev,
+					  dbuf,
+					  planes[plane].length);
+		if (IS_ERR(mem_priv)) {
+			dprintk(q, 1, "failed to attach dmabuf\n");
+			ret = PTR_ERR(mem_priv);
+			dma_buf_put(dbuf);
+			goto err;
+		}
+
+		vb->planes[plane].dbuf = dbuf;
+		vb->planes[plane].mem_priv = mem_priv;
+	}
+
+	/*
+	 * This pins the buffer(s) with dma_buf_map_attachment()). It's done
+	 * here instead just before the DMA, while queueing the buffer(s) so
+	 * userspace knows sooner rather than later if the dma-buf map fails.
+	 */
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		if (vb->planes[plane].dbuf_mapped)
+			continue;
+
+		ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
+		if (ret) {
+			dprintk(q, 1, "failed to map dmabuf for plane %d\n",
+				plane);
+			goto err;
+		}
+		vb->planes[plane].dbuf_mapped = 1;
+	}
+
+	/*
+	 * Now that everything is in order, copy relevant information
+	 * provided by userspace.
+	 */
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		vb->planes[plane].bytesused = planes[plane].bytesused;
+		vb->planes[plane].length = planes[plane].length;
+		vb->planes[plane].m.fd = planes[plane].m.fd;
+		vb->planes[plane].data_offset = planes[plane].data_offset;
+	}
+
+	if (reacquired) {
+		/*
+		 * Call driver-specific initialization on the newly acquired buffer,
+		 * if provided.
+		 */
+		ret = call_vb_qop(vb, buf_init, vb);
+		if (ret) {
+			dprintk(q, 1, "buffer initialization failed\n");
+			goto err;
+		}
+	}
+
+	ret = call_vb_qop(vb, buf_prepare, vb);
+	if (ret) {
+		dprintk(q, 1, "buffer preparation failed\n");
+		call_void_vb_qop(vb, buf_cleanup, vb);
+		goto err;
+	}
+
+	return 0;
+err:
+	/* In case of errors, release planes that were already acquired */
+	__vb2_buf_dmabuf_put(vb);
+
+	return ret;
+}
+
+/*
+ * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
+ */
+static void __enqueue_in_driver(struct vb2_buffer *vb)
+{
+	struct vb2_queue *q = vb->vb2_queue;
+
+	vb->state = VB2_BUF_STATE_ACTIVE;
+	atomic_inc(&q->owned_by_drv_count);
+
+	trace_vb2_buf_queue(q, vb);
+
+	call_void_vb_qop(vb, buf_queue, vb);
+}
+
+static int __buf_prepare(struct vb2_buffer *vb)
+{
+	struct vb2_queue *q = vb->vb2_queue;
+	enum vb2_buffer_state orig_state = vb->state;
+	int ret;
+
+	if (q->error) {
+		dprintk(q, 1, "fatal error occurred on queue\n");
+		return -EIO;
+	}
+
+	if (vb->prepared)
+		return 0;
+	WARN_ON(vb->synced);
+
+	if (q->is_output) {
+		ret = call_vb_qop(vb, buf_out_validate, vb);
+		if (ret) {
+			dprintk(q, 1, "buffer validation failed\n");
+			return ret;
+		}
+	}
+
+	vb->state = VB2_BUF_STATE_PREPARING;
+
+	switch (q->memory) {
+	case VB2_MEMORY_MMAP:
+		ret = __prepare_mmap(vb);
+		break;
+	case VB2_MEMORY_USERPTR:
+		ret = __prepare_userptr(vb);
+		break;
+	case VB2_MEMORY_DMABUF:
+		ret = __prepare_dmabuf(vb);
+		break;
+	default:
+		WARN(1, "Invalid queue type\n");
+		ret = -EINVAL;
+		break;
+	}
+
+	if (ret) {
+		dprintk(q, 1, "buffer preparation failed: %d\n", ret);
+		vb->state = orig_state;
+		return ret;
+	}
+
+	__vb2_buf_mem_prepare(vb);
+	vb->prepared = 1;
+	vb->state = orig_state;
+
+	return 0;
+}
+
+static int vb2_req_prepare(struct media_request_object *obj)
+{
+	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
+	int ret;
+
+	if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
+		return -EINVAL;
+
+	mutex_lock(vb->vb2_queue->lock);
+	ret = __buf_prepare(vb);
+	mutex_unlock(vb->vb2_queue->lock);
+	return ret;
+}
+
+static void __vb2_dqbuf(struct vb2_buffer *vb);
+
+static void vb2_req_unprepare(struct media_request_object *obj)
+{
+	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
+
+	mutex_lock(vb->vb2_queue->lock);
+	__vb2_dqbuf(vb);
+	vb->state = VB2_BUF_STATE_IN_REQUEST;
+	mutex_unlock(vb->vb2_queue->lock);
+	WARN_ON(!vb->req_obj.req);
+}
+
+int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
+		  struct media_request *req);
+
+static void vb2_req_queue(struct media_request_object *obj)
+{
+	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
+	int err;
+
+	mutex_lock(vb->vb2_queue->lock);
+	/*
+	 * There is no method to propagate an error from vb2_core_qbuf(),
+	 * so if this returns a non-0 value, then WARN.
+	 *
+	 * The only exception is -EIO which is returned if q->error is
+	 * set. We just ignore that, and expect this will be caught the
+	 * next time vb2_req_prepare() is called.
+	 */
+	err = vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
+	WARN_ON_ONCE(err && err != -EIO);
+	mutex_unlock(vb->vb2_queue->lock);
+}
+
+static void vb2_req_unbind(struct media_request_object *obj)
+{
+	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
+
+	if (vb->state == VB2_BUF_STATE_IN_REQUEST)
+		call_void_bufop(vb->vb2_queue, init_buffer, vb);
+}
+
+static void vb2_req_release(struct media_request_object *obj)
+{
+	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
+
+	if (vb->state == VB2_BUF_STATE_IN_REQUEST) {
+		vb->state = VB2_BUF_STATE_DEQUEUED;
+		if (vb->request)
+			media_request_put(vb->request);
+		vb->request = NULL;
+	}
+}
+
+static const struct media_request_object_ops vb2_core_req_ops = {
+	.prepare = vb2_req_prepare,
+	.unprepare = vb2_req_unprepare,
+	.queue = vb2_req_queue,
+	.unbind = vb2_req_unbind,
+	.release = vb2_req_release,
+};
+
+bool vb2_request_object_is_buffer(struct media_request_object *obj)
+{
+	return obj->ops == &vb2_core_req_ops;
+}
+EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
+
+unsigned int vb2_request_buffer_cnt(struct media_request *req)
+{
+	struct media_request_object *obj;
+	unsigned long flags;
+	unsigned int buffer_cnt = 0;
+
+	spin_lock_irqsave(&req->lock, flags);
+	list_for_each_entry(obj, &req->objects, list)
+		if (vb2_request_object_is_buffer(obj))
+			buffer_cnt++;
+	spin_unlock_irqrestore(&req->lock, flags);
+
+	return buffer_cnt;
+}
+EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
+
+int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
+{
+	struct vb2_buffer *vb;
+	int ret;
+
+	vb = q->bufs[index];
+	if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+		dprintk(q, 1, "invalid buffer state %s\n",
+			vb2_state_name(vb->state));
+		return -EINVAL;
+	}
+	if (vb->prepared) {
+		dprintk(q, 1, "buffer already prepared\n");
+		return -EINVAL;
+	}
+
+	ret = __buf_prepare(vb);
+	if (ret)
+		return ret;
+
+	/* Fill buffer information for the userspace */
+	call_void_bufop(q, fill_user_buffer, vb, pb);
+
+	dprintk(q, 2, "prepare of buffer %d succeeded\n", vb->index);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
+
+/*
+ * vb2_start_streaming() - Attempt to start streaming.
+ * @q:		videobuf2 queue
+ *
+ * Attempt to start streaming. When this function is called there must be
+ * at least q->min_buffers_needed buffers queued up (i.e. the minimum
+ * number of buffers required for the DMA engine to function). If the
+ * @start_streaming op fails it is supposed to return all the driver-owned
+ * buffers back to vb2 in state QUEUED. Check if that happened and if
+ * not warn and reclaim them forcefully.
+ */
+static int vb2_start_streaming(struct vb2_queue *q)
+{
+	struct vb2_buffer *vb;
+	int ret;
+
+	/*
+	 * If any buffers were queued before streamon,
+	 * we can now pass them to driver for processing.
+	 */
+	list_for_each_entry(vb, &q->queued_list, queued_entry)
+		__enqueue_in_driver(vb);
+
+	/* Tell the driver to start streaming */
+	q->start_streaming_called = 1;
+	ret = call_qop(q, start_streaming, q,
+		       atomic_read(&q->owned_by_drv_count));
+	if (!ret)
+		return 0;
+
+	q->start_streaming_called = 0;
+
+	dprintk(q, 1, "driver refused to start streaming\n");
+	/*
+	 * If you see this warning, then the driver isn't cleaning up properly
+	 * after a failed start_streaming(). See the start_streaming()
+	 * documentation in videobuf2-core.h for more information how buffers
+	 * should be returned to vb2 in start_streaming().
+	 */
+	if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
+		unsigned i;
+
+		/*
+		 * Forcefully reclaim buffers if the driver did not
+		 * correctly return them to vb2.
+		 */
+		for (i = 0; i < q->num_buffers; ++i) {
+			vb = q->bufs[i];
+			if (vb->state == VB2_BUF_STATE_ACTIVE)
+				vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
+		}
+		/* Must be zero now */
+		WARN_ON(atomic_read(&q->owned_by_drv_count));
+	}
+	/*
+	 * If done_list is not empty, then start_streaming() didn't call
+	 * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
+	 * STATE_DONE.
+	 */
+	WARN_ON(!list_empty(&q->done_list));
+	return ret;
+}
+
+int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
+		  struct media_request *req)
+{
+	struct vb2_buffer *vb;
+	enum vb2_buffer_state orig_state;
+	int ret;
+
+	if (q->error) {
+		dprintk(q, 1, "fatal error occurred on queue\n");
+		return -EIO;
+	}
+
+	vb = q->bufs[index];
+
+	if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
+	    q->requires_requests) {
+		dprintk(q, 1, "qbuf requires a request\n");
+		return -EBADR;
+	}
+
+	if ((req && q->uses_qbuf) ||
+	    (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
+	     q->uses_requests)) {
+		dprintk(q, 1, "queue in wrong mode (qbuf vs requests)\n");
+		return -EBUSY;
+	}
+
+	if (req) {
+		int ret;
+
+		q->uses_requests = 1;
+		if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+			dprintk(q, 1, "buffer %d not in dequeued state\n",
+				vb->index);
+			return -EINVAL;
+		}
+
+		if (q->is_output && !vb->prepared) {
+			ret = call_vb_qop(vb, buf_out_validate, vb);
+			if (ret) {
+				dprintk(q, 1, "buffer validation failed\n");
+				return ret;
+			}
+		}
+
+		media_request_object_init(&vb->req_obj);
+
+		/* Make sure the request is in a safe state for updating. */
+		ret = media_request_lock_for_update(req);
+		if (ret)
+			return ret;
+		ret = media_request_object_bind(req, &vb2_core_req_ops,
+						q, true, &vb->req_obj);
+		media_request_unlock_for_update(req);
+		if (ret)
+			return ret;
+
+		vb->state = VB2_BUF_STATE_IN_REQUEST;
+
+		/*
+		 * Increment the refcount and store the request.
+		 * The request refcount is decremented again when the
+		 * buffer is dequeued. This is to prevent vb2_buffer_done()
+		 * from freeing the request from interrupt context, which can
+		 * happen if the application closed the request fd after
+		 * queueing the request.
+		 */
+		media_request_get(req);
+		vb->request = req;
+
+		/* Fill buffer information for the userspace */
+		if (pb) {
+			call_void_bufop(q, copy_timestamp, vb, pb);
+			call_void_bufop(q, fill_user_buffer, vb, pb);
+		}
+
+		dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
+		return 0;
+	}
+
+	if (vb->state != VB2_BUF_STATE_IN_REQUEST)
+		q->uses_qbuf = 1;
+
+	switch (vb->state) {
+	case VB2_BUF_STATE_DEQUEUED:
+	case VB2_BUF_STATE_IN_REQUEST:
+		if (!vb->prepared) {
+			ret = __buf_prepare(vb);
+			if (ret)
+				return ret;
+		}
+		break;
+	case VB2_BUF_STATE_PREPARING:
+		dprintk(q, 1, "buffer still being prepared\n");
+		return -EINVAL;
+	default:
+		dprintk(q, 1, "invalid buffer state %s\n",
+			vb2_state_name(vb->state));
+		return -EINVAL;
+	}
+
+	/*
+	 * Add to the queued buffers list, a buffer will stay on it until
+	 * dequeued in dqbuf.
+	 */
+	orig_state = vb->state;
+	list_add_tail(&vb->queued_entry, &q->queued_list);
+	q->queued_count++;
+	q->waiting_for_buffers = false;
+	vb->state = VB2_BUF_STATE_QUEUED;
+
+	if (pb)
+		call_void_bufop(q, copy_timestamp, vb, pb);
+
+	trace_vb2_qbuf(q, vb);
+
+	/*
+	 * If already streaming, give the buffer to driver for processing.
+	 * If not, the buffer will be given to driver on next streamon.
+	 */
+	if (q->start_streaming_called)
+		__enqueue_in_driver(vb);
+
+	/* Fill buffer information for the userspace */
+	if (pb)
+		call_void_bufop(q, fill_user_buffer, vb, pb);
+
+	/*
+	 * If streamon has been called, and we haven't yet called
+	 * start_streaming() since not enough buffers were queued, and
+	 * we now have reached the minimum number of queued buffers,
+	 * then we can finally call start_streaming().
+	 */
+	if (q->streaming && !q->start_streaming_called &&
+	    q->queued_count >= q->min_buffers_needed) {
+		ret = vb2_start_streaming(q);
+		if (ret) {
+			/*
+			 * Since vb2_core_qbuf will return with an error,
+			 * we should return it to state DEQUEUED since
+			 * the error indicates that the buffer wasn't queued.
+			 */
+			list_del(&vb->queued_entry);
+			q->queued_count--;
+			vb->state = orig_state;
+			return ret;
+		}
+	}
+
+	dprintk(q, 2, "qbuf of buffer %d succeeded\n", vb->index);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_core_qbuf);
+
+/*
+ * __vb2_wait_for_done_vb() - wait for a buffer to become available
+ * for dequeuing
+ *
+ * Will sleep if required for nonblocking == false.
+ */
+static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
+{
+	/*
+	 * All operations on vb_done_list are performed under done_lock
+	 * spinlock protection. However, buffers may be removed from
+	 * it and returned to userspace only while holding both driver's
+	 * lock and the done_lock spinlock. Thus we can be sure that as
+	 * long as we hold the driver's lock, the list will remain not
+	 * empty if list_empty() check succeeds.
+	 */
+
+	for (;;) {
+		int ret;
+
+		if (q->waiting_in_dqbuf) {
+			dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
+			return -EBUSY;
+		}
+
+		if (!q->streaming) {
+			dprintk(q, 1, "streaming off, will not wait for buffers\n");
+			return -EINVAL;
+		}
+
+		if (q->error) {
+			dprintk(q, 1, "Queue in error state, will not wait for buffers\n");
+			return -EIO;
+		}
+
+		if (q->last_buffer_dequeued) {
+			dprintk(q, 3, "last buffer dequeued already, will not wait for buffers\n");
+			return -EPIPE;
+		}
+
+		if (!list_empty(&q->done_list)) {
+			/*
+			 * Found a buffer that we were waiting for.
+			 */
+			break;
+		}
+
+		if (nonblocking) {
+			dprintk(q, 3, "nonblocking and no buffers to dequeue, will not wait\n");
+			return -EAGAIN;
+		}
+
+		q->waiting_in_dqbuf = 1;
+		/*
+		 * We are streaming and blocking, wait for another buffer to
+		 * become ready or for streamoff. Driver's lock is released to
+		 * allow streamoff or qbuf to be called while waiting.
+		 */
+		call_void_qop(q, wait_prepare, q);
+
+		/*
+		 * All locks have been released, it is safe to sleep now.
+		 */
+		dprintk(q, 3, "will sleep waiting for buffers\n");
+		ret = wait_event_interruptible(q->done_wq,
+				!list_empty(&q->done_list) || !q->streaming ||
+				q->error);
+
+		/*
+		 * We need to reevaluate both conditions again after reacquiring
+		 * the locks or return an error if one occurred.
+		 */
+		call_void_qop(q, wait_finish, q);
+		q->waiting_in_dqbuf = 0;
+		if (ret) {
+			dprintk(q, 1, "sleep was interrupted\n");
+			return ret;
+		}
+	}
+	return 0;
+}
+
+/*
+ * __vb2_get_done_vb() - get a buffer ready for dequeuing
+ *
+ * Will sleep if required for nonblocking == false.
+ */
+static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
+			     void *pb, int nonblocking)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	/*
+	 * Wait for at least one buffer to become available on the done_list.
+	 */
+	ret = __vb2_wait_for_done_vb(q, nonblocking);
+	if (ret)
+		return ret;
+
+	/*
+	 * Driver's lock has been held since we last verified that done_list
+	 * is not empty, so no need for another list_empty(done_list) check.
+	 */
+	spin_lock_irqsave(&q->done_lock, flags);
+	*vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
+	/*
+	 * Only remove the buffer from done_list if all planes can be
+	 * handled. Some cases such as V4L2 file I/O and DVB have pb
+	 * == NULL; skip the check then as there's nothing to verify.
+	 */
+	if (pb)
+		ret = call_bufop(q, verify_planes_array, *vb, pb);
+	if (!ret)
+		list_del(&(*vb)->done_entry);
+	spin_unlock_irqrestore(&q->done_lock, flags);
+
+	return ret;
+}
+
+int vb2_wait_for_all_buffers(struct vb2_queue *q)
+{
+	if (!q->streaming) {
+		dprintk(q, 1, "streaming off, will not wait for buffers\n");
+		return -EINVAL;
+	}
+
+	if (q->start_streaming_called)
+		wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count));
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
+
+/*
+ * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
+ */
+static void __vb2_dqbuf(struct vb2_buffer *vb)
+{
+	struct vb2_queue *q = vb->vb2_queue;
+
+	/* nothing to do if the buffer is already dequeued */
+	if (vb->state == VB2_BUF_STATE_DEQUEUED)
+		return;
+
+	vb->state = VB2_BUF_STATE_DEQUEUED;
+
+	call_void_bufop(q, init_buffer, vb);
+}
+
+int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
+		   bool nonblocking)
+{
+	struct vb2_buffer *vb = NULL;
+	int ret;
+
+	ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
+	if (ret < 0)
+		return ret;
+
+	switch (vb->state) {
+	case VB2_BUF_STATE_DONE:
+		dprintk(q, 3, "returning done buffer\n");
+		break;
+	case VB2_BUF_STATE_ERROR:
+		dprintk(q, 3, "returning done buffer with errors\n");
+		break;
+	default:
+		dprintk(q, 1, "invalid buffer state %s\n",
+			vb2_state_name(vb->state));
+		return -EINVAL;
+	}
+
+	call_void_vb_qop(vb, buf_finish, vb);
+	vb->prepared = 0;
+
+	if (pindex)
+		*pindex = vb->index;
+
+	/* Fill buffer information for the userspace */
+	if (pb)
+		call_void_bufop(q, fill_user_buffer, vb, pb);
+
+	/* Remove from vb2 queue */
+	list_del(&vb->queued_entry);
+	q->queued_count--;
+
+	trace_vb2_dqbuf(q, vb);
+
+	/* go back to dequeued state */
+	__vb2_dqbuf(vb);
+
+	if (WARN_ON(vb->req_obj.req)) {
+		media_request_object_unbind(&vb->req_obj);
+		media_request_object_put(&vb->req_obj);
+	}
+	if (vb->request)
+		media_request_put(vb->request);
+	vb->request = NULL;
+
+	dprintk(q, 2, "dqbuf of buffer %d, state: %s\n",
+		vb->index, vb2_state_name(vb->state));
+
+	return 0;
+
+}
+EXPORT_SYMBOL_GPL(vb2_core_dqbuf);
+
+/*
+ * __vb2_queue_cancel() - cancel and stop (pause) streaming
+ *
+ * Removes all queued buffers from driver's queue and all buffers queued by
+ * userspace from vb2's queue. Returns to state after reqbufs.
+ */
+static void __vb2_queue_cancel(struct vb2_queue *q)
+{
+	unsigned int i;
+
+	/*
+	 * Tell driver to stop all transactions and release all queued
+	 * buffers.
+	 */
+	if (q->start_streaming_called)
+		call_void_qop(q, stop_streaming, q);
+
+	/*
+	 * If you see this warning, then the driver isn't cleaning up properly
+	 * in stop_streaming(). See the stop_streaming() documentation in
+	 * videobuf2-core.h for more information how buffers should be returned
+	 * to vb2 in stop_streaming().
+	 */
+	if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
+		for (i = 0; i < q->num_buffers; ++i)
+			if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
+				pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
+					q->bufs[i]);
+				vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
+			}
+		/* Must be zero now */
+		WARN_ON(atomic_read(&q->owned_by_drv_count));
+	}
+
+	q->streaming = 0;
+	q->start_streaming_called = 0;
+	q->queued_count = 0;
+	q->error = 0;
+	q->uses_requests = 0;
+	q->uses_qbuf = 0;
+
+	/*
+	 * Remove all buffers from vb2's list...
+	 */
+	INIT_LIST_HEAD(&q->queued_list);
+	/*
+	 * ...and done list; userspace will not receive any buffers it
+	 * has not already dequeued before initiating cancel.
+	 */
+	INIT_LIST_HEAD(&q->done_list);
+	atomic_set(&q->owned_by_drv_count, 0);
+	wake_up_all(&q->done_wq);
+
+	/*
+	 * Reinitialize all buffers for next use.
+	 * Make sure to call buf_finish for any queued buffers. Normally
+	 * that's done in dqbuf, but that's not going to happen when we
+	 * cancel the whole queue. Note: this code belongs here, not in
+	 * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical
+	 * call to __fill_user_buffer() after buf_finish(). That order can't
+	 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
+	 */
+	for (i = 0; i < q->num_buffers; ++i) {
+		struct vb2_buffer *vb = q->bufs[i];
+		struct media_request *req = vb->req_obj.req;
+
+		/*
+		 * If a request is associated with this buffer, then
+		 * call buf_request_cancel() to give the driver to complete()
+		 * related request objects. Otherwise those objects would
+		 * never complete.
+		 */
+		if (req) {
+			enum media_request_state state;
+			unsigned long flags;
+
+			spin_lock_irqsave(&req->lock, flags);
+			state = req->state;
+			spin_unlock_irqrestore(&req->lock, flags);
+
+			if (state == MEDIA_REQUEST_STATE_QUEUED)
+				call_void_vb_qop(vb, buf_request_complete, vb);
+		}
+
+		__vb2_buf_mem_finish(vb);
+
+		if (vb->prepared) {
+			call_void_vb_qop(vb, buf_finish, vb);
+			vb->prepared = 0;
+		}
+		__vb2_dqbuf(vb);
+
+		if (vb->req_obj.req) {
+			media_request_object_unbind(&vb->req_obj);
+			media_request_object_put(&vb->req_obj);
+		}
+		if (vb->request)
+			media_request_put(vb->request);
+		vb->request = NULL;
+		vb->copied_timestamp = 0;
+	}
+}
+
+int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
+{
+	int ret;
+
+	if (type != q->type) {
+		dprintk(q, 1, "invalid stream type\n");
+		return -EINVAL;
+	}
+
+	if (q->streaming) {
+		dprintk(q, 3, "already streaming\n");
+		return 0;
+	}
+
+	if (!q->num_buffers) {
+		dprintk(q, 1, "no buffers have been allocated\n");
+		return -EINVAL;
+	}
+
+	if (q->num_buffers < q->min_buffers_needed) {
+		dprintk(q, 1, "need at least %u allocated buffers\n",
+				q->min_buffers_needed);
+		return -EINVAL;
+	}
+
+	/*
+	 * Tell driver to start streaming provided sufficient buffers
+	 * are available.
+	 */
+	if (q->queued_count >= q->min_buffers_needed) {
+		ret = v4l_vb2q_enable_media_source(q);
+		if (ret)
+			return ret;
+		ret = vb2_start_streaming(q);
+		if (ret)
+			return ret;
+	}
+
+	q->streaming = 1;
+
+	dprintk(q, 3, "successful\n");
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_core_streamon);
+
+void vb2_queue_error(struct vb2_queue *q)
+{
+	q->error = 1;
+
+	wake_up_all(&q->done_wq);
+}
+EXPORT_SYMBOL_GPL(vb2_queue_error);
+
+int vb2_core_streamoff(struct vb2_queue *q, unsigned int type)
+{
+	if (type != q->type) {
+		dprintk(q, 1, "invalid stream type\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Cancel will pause streaming and remove all buffers from the driver
+	 * and vb2, effectively returning control over them to userspace.
+	 *
+	 * Note that we do this even if q->streaming == 0: if you prepare or
+	 * queue buffers, and then call streamoff without ever having called
+	 * streamon, you would still expect those buffers to be returned to
+	 * their normal dequeued state.
+	 */
+	__vb2_queue_cancel(q);
+	q->waiting_for_buffers = !q->is_output;
+	q->last_buffer_dequeued = false;
+
+	dprintk(q, 3, "successful\n");
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_core_streamoff);
+
+/*
+ * __find_plane_by_offset() - find plane associated with the given offset off
+ */
+static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
+			unsigned int *_buffer, unsigned int *_plane)
+{
+	struct vb2_buffer *vb;
+	unsigned int buffer, plane;
+
+	/*
+	 * Sanity checks to ensure the lock is held, MEMORY_MMAP is
+	 * used and fileio isn't active.
+	 */
+	lockdep_assert_held(&q->mmap_lock);
+
+	if (q->memory != VB2_MEMORY_MMAP) {
+		dprintk(q, 1, "queue is not currently set up for mmap\n");
+		return -EINVAL;
+	}
+
+	if (vb2_fileio_is_active(q)) {
+		dprintk(q, 1, "file io in progress\n");
+		return -EBUSY;
+	}
+
+	/*
+	 * Go over all buffers and their planes, comparing the given offset
+	 * with an offset assigned to each plane. If a match is found,
+	 * return its buffer and plane numbers.
+	 */
+	for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+		vb = q->bufs[buffer];
+
+		for (plane = 0; plane < vb->num_planes; ++plane) {
+			if (vb->planes[plane].m.offset == off) {
+				*_buffer = buffer;
+				*_plane = plane;
+				return 0;
+			}
+		}
+	}
+
+	return -EINVAL;
+}
+
+int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
+		unsigned int index, unsigned int plane, unsigned int flags)
+{
+	struct vb2_buffer *vb = NULL;
+	struct vb2_plane *vb_plane;
+	int ret;
+	struct dma_buf *dbuf;
+
+	if (q->memory != VB2_MEMORY_MMAP) {
+		dprintk(q, 1, "queue is not currently set up for mmap\n");
+		return -EINVAL;
+	}
+
+	if (!q->mem_ops->get_dmabuf) {
+		dprintk(q, 1, "queue does not support DMA buffer exporting\n");
+		return -EINVAL;
+	}
+
+	if (flags & ~(O_CLOEXEC | O_ACCMODE)) {
+		dprintk(q, 1, "queue does support only O_CLOEXEC and access mode flags\n");
+		return -EINVAL;
+	}
+
+	if (type != q->type) {
+		dprintk(q, 1, "invalid buffer type\n");
+		return -EINVAL;
+	}
+
+	if (index >= q->num_buffers) {
+		dprintk(q, 1, "buffer index out of range\n");
+		return -EINVAL;
+	}
+
+	vb = q->bufs[index];
+
+	if (plane >= vb->num_planes) {
+		dprintk(q, 1, "buffer plane out of range\n");
+		return -EINVAL;
+	}
+
+	if (vb2_fileio_is_active(q)) {
+		dprintk(q, 1, "expbuf: file io in progress\n");
+		return -EBUSY;
+	}
+
+	vb_plane = &vb->planes[plane];
+
+	dbuf = call_ptr_memop(get_dmabuf,
+			      vb,
+			      vb_plane->mem_priv,
+			      flags & O_ACCMODE);
+	if (IS_ERR_OR_NULL(dbuf)) {
+		dprintk(q, 1, "failed to export buffer %d, plane %d\n",
+			index, plane);
+		return -EINVAL;
+	}
+
+	ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
+	if (ret < 0) {
+		dprintk(q, 3, "buffer %d, plane %d failed to export (%d)\n",
+			index, plane, ret);
+		dma_buf_put(dbuf);
+		return ret;
+	}
+
+	dprintk(q, 3, "buffer %d, plane %d exported as %d descriptor\n",
+		index, plane, ret);
+	*fd = ret;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_core_expbuf);
+
+int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
+{
+	unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
+	struct vb2_buffer *vb;
+	unsigned int buffer = 0, plane = 0;
+	int ret;
+	unsigned long length;
+
+	/*
+	 * Check memory area access mode.
+	 */
+	if (!(vma->vm_flags & VM_SHARED)) {
+		dprintk(q, 1, "invalid vma flags, VM_SHARED needed\n");
+		return -EINVAL;
+	}
+	if (q->is_output) {
+		if (!(vma->vm_flags & VM_WRITE)) {
+			dprintk(q, 1, "invalid vma flags, VM_WRITE needed\n");
+			return -EINVAL;
+		}
+	} else {
+		if (!(vma->vm_flags & VM_READ)) {
+			dprintk(q, 1, "invalid vma flags, VM_READ needed\n");
+			return -EINVAL;
+		}
+	}
+
+	mutex_lock(&q->mmap_lock);
+
+	/*
+	 * Find the plane corresponding to the offset passed by userspace. This
+	 * will return an error if not MEMORY_MMAP or file I/O is in progress.
+	 */
+	ret = __find_plane_by_offset(q, off, &buffer, &plane);
+	if (ret)
+		goto unlock;
+
+	vb = q->bufs[buffer];
+
+	/*
+	 * MMAP requires page_aligned buffers.
+	 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
+	 * so, we need to do the same here.
+	 */
+	length = PAGE_ALIGN(vb->planes[plane].length);
+	if (length < (vma->vm_end - vma->vm_start)) {
+		dprintk(q, 1,
+			"MMAP invalid, as it would overflow buffer length\n");
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	/*
+	 * vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer,
+	 * not as a in-buffer offset. We always want to mmap a whole buffer
+	 * from its beginning.
+	 */
+	vma->vm_pgoff = 0;
+
+	ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma);
+
+unlock:
+	mutex_unlock(&q->mmap_lock);
+	if (ret)
+		return ret;
+
+	dprintk(q, 3, "buffer %d, plane %d successfully mapped\n", buffer, plane);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_mmap);
+
+#ifndef CONFIG_MMU
+unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
+				    unsigned long addr,
+				    unsigned long len,
+				    unsigned long pgoff,
+				    unsigned long flags)
+{
+	unsigned long off = pgoff << PAGE_SHIFT;
+	struct vb2_buffer *vb;
+	unsigned int buffer, plane;
+	void *vaddr;
+	int ret;
+
+	mutex_lock(&q->mmap_lock);
+
+	/*
+	 * Find the plane corresponding to the offset passed by userspace. This
+	 * will return an error if not MEMORY_MMAP or file I/O is in progress.
+	 */
+	ret = __find_plane_by_offset(q, off, &buffer, &plane);
+	if (ret)
+		goto unlock;
+
+	vb = q->bufs[buffer];
+
+	vaddr = vb2_plane_vaddr(vb, plane);
+	mutex_unlock(&q->mmap_lock);
+	return vaddr ? (unsigned long)vaddr : -EINVAL;
+
+unlock:
+	mutex_unlock(&q->mmap_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
+#endif
+
+int vb2_core_queue_init(struct vb2_queue *q)
+{
+	/*
+	 * Sanity check
+	 */
+	if (WARN_ON(!q)			  ||
+	    WARN_ON(!q->ops)		  ||
+	    WARN_ON(!q->mem_ops)	  ||
+	    WARN_ON(!q->type)		  ||
+	    WARN_ON(!q->io_modes)	  ||
+	    WARN_ON(!q->ops->queue_setup) ||
+	    WARN_ON(!q->ops->buf_queue))
+		return -EINVAL;
+
+	if (WARN_ON(q->requires_requests && !q->supports_requests))
+		return -EINVAL;
+
+	/*
+	 * This combination is not allowed since a non-zero value of
+	 * q->min_buffers_needed can cause vb2_core_qbuf() to fail if
+	 * it has to call start_streaming(), and the Request API expects
+	 * that queueing a request (and thus queueing a buffer contained
+	 * in that request) will always succeed. There is no method of
+	 * propagating an error back to userspace.
+	 */
+	if (WARN_ON(q->supports_requests && q->min_buffers_needed))
+		return -EINVAL;
+
+	INIT_LIST_HEAD(&q->queued_list);
+	INIT_LIST_HEAD(&q->done_list);
+	spin_lock_init(&q->done_lock);
+	mutex_init(&q->mmap_lock);
+	init_waitqueue_head(&q->done_wq);
+
+	q->memory = VB2_MEMORY_UNKNOWN;
+
+	if (q->buf_struct_size == 0)
+		q->buf_struct_size = sizeof(struct vb2_buffer);
+
+	if (q->bidirectional)
+		q->dma_dir = DMA_BIDIRECTIONAL;
+	else
+		q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+	if (q->name[0] == '\0')
+		snprintf(q->name, sizeof(q->name), "%s-%p",
+			 q->is_output ? "out" : "cap", q);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_core_queue_init);
+
+static int __vb2_init_fileio(struct vb2_queue *q, int read);
+static int __vb2_cleanup_fileio(struct vb2_queue *q);
+void vb2_core_queue_release(struct vb2_queue *q)
+{
+	__vb2_cleanup_fileio(q);
+	__vb2_queue_cancel(q);
+	mutex_lock(&q->mmap_lock);
+	__vb2_queue_free(q, q->num_buffers);
+	mutex_unlock(&q->mmap_lock);
+}
+EXPORT_SYMBOL_GPL(vb2_core_queue_release);
+
+__poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
+		poll_table *wait)
+{
+	__poll_t req_events = poll_requested_events(wait);
+	struct vb2_buffer *vb = NULL;
+	unsigned long flags;
+
+	/*
+	 * poll_wait() MUST be called on the first invocation on all the
+	 * potential queues of interest, even if we are not interested in their
+	 * events during this first call. Failure to do so will result in
+	 * queue's events to be ignored because the poll_table won't be capable
+	 * of adding new wait queues thereafter.
+	 */
+	poll_wait(file, &q->done_wq, wait);
+
+	if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
+		return 0;
+	if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
+		return 0;
+
+	/*
+	 * Start file I/O emulator only if streaming API has not been used yet.
+	 */
+	if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
+		if (!q->is_output && (q->io_modes & VB2_READ) &&
+				(req_events & (EPOLLIN | EPOLLRDNORM))) {
+			if (__vb2_init_fileio(q, 1))
+				return EPOLLERR;
+		}
+		if (q->is_output && (q->io_modes & VB2_WRITE) &&
+				(req_events & (EPOLLOUT | EPOLLWRNORM))) {
+			if (__vb2_init_fileio(q, 0))
+				return EPOLLERR;
+			/*
+			 * Write to OUTPUT queue can be done immediately.
+			 */
+			return EPOLLOUT | EPOLLWRNORM;
+		}
+	}
+
+	/*
+	 * There is nothing to wait for if the queue isn't streaming, or if the
+	 * error flag is set.
+	 */
+	if (!vb2_is_streaming(q) || q->error)
+		return EPOLLERR;
+
+	/*
+	 * If this quirk is set and QBUF hasn't been called yet then
+	 * return EPOLLERR as well. This only affects capture queues, output
+	 * queues will always initialize waiting_for_buffers to false.
+	 * This quirk is set by V4L2 for backwards compatibility reasons.
+	 */
+	if (q->quirk_poll_must_check_waiting_for_buffers &&
+	    q->waiting_for_buffers && (req_events & (EPOLLIN | EPOLLRDNORM)))
+		return EPOLLERR;
+
+	/*
+	 * For output streams you can call write() as long as there are fewer
+	 * buffers queued than there are buffers available.
+	 */
+	if (q->is_output && q->fileio && q->queued_count < q->num_buffers)
+		return EPOLLOUT | EPOLLWRNORM;
+
+	if (list_empty(&q->done_list)) {
+		/*
+		 * If the last buffer was dequeued from a capture queue,
+		 * return immediately. DQBUF will return -EPIPE.
+		 */
+		if (q->last_buffer_dequeued)
+			return EPOLLIN | EPOLLRDNORM;
+	}
+
+	/*
+	 * Take first buffer available for dequeuing.
+	 */
+	spin_lock_irqsave(&q->done_lock, flags);
+	if (!list_empty(&q->done_list))
+		vb = list_first_entry(&q->done_list, struct vb2_buffer,
+					done_entry);
+	spin_unlock_irqrestore(&q->done_lock, flags);
+
+	if (vb && (vb->state == VB2_BUF_STATE_DONE
+			|| vb->state == VB2_BUF_STATE_ERROR)) {
+		return (q->is_output) ?
+				EPOLLOUT | EPOLLWRNORM :
+				EPOLLIN | EPOLLRDNORM;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_core_poll);
+
+/*
+ * struct vb2_fileio_buf - buffer context used by file io emulator
+ *
+ * vb2 provides a compatibility layer and emulator of file io (read and
+ * write) calls on top of streaming API. This structure is used for
+ * tracking context related to the buffers.
+ */
+struct vb2_fileio_buf {
+	void *vaddr;
+	unsigned int size;
+	unsigned int pos;
+	unsigned int queued:1;
+};
+
+/*
+ * struct vb2_fileio_data - queue context used by file io emulator
+ *
+ * @cur_index:	the index of the buffer currently being read from or
+ *		written to. If equal to q->num_buffers then a new buffer
+ *		must be dequeued.
+ * @initial_index: in the read() case all buffers are queued up immediately
+ *		in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
+ *		buffers. However, in the write() case no buffers are initially
+ *		queued, instead whenever a buffer is full it is queued up by
+ *		__vb2_perform_fileio(). Only once all available buffers have
+ *		been queued up will __vb2_perform_fileio() start to dequeue
+ *		buffers. This means that initially __vb2_perform_fileio()
+ *		needs to know what buffer index to use when it is queuing up
+ *		the buffers for the first time. That initial index is stored
+ *		in this field. Once it is equal to q->num_buffers all
+ *		available buffers have been queued and __vb2_perform_fileio()
+ *		should start the normal dequeue/queue cycle.
+ *
+ * vb2 provides a compatibility layer and emulator of file io (read and
+ * write) calls on top of streaming API. For proper operation it required
+ * this structure to save the driver state between each call of the read
+ * or write function.
+ */
+struct vb2_fileio_data {
+	unsigned int count;
+	unsigned int type;
+	unsigned int memory;
+	struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
+	unsigned int cur_index;
+	unsigned int initial_index;
+	unsigned int q_count;
+	unsigned int dq_count;
+	unsigned read_once:1;
+	unsigned write_immediately:1;
+};
+
+/*
+ * __vb2_init_fileio() - initialize file io emulator
+ * @q:		videobuf2 queue
+ * @read:	mode selector (1 means read, 0 means write)
+ */
+static int __vb2_init_fileio(struct vb2_queue *q, int read)
+{
+	struct vb2_fileio_data *fileio;
+	int i, ret;
+	unsigned int count = 0;
+
+	/*
+	 * Sanity check
+	 */
+	if (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
+		    (!read && !(q->io_modes & VB2_WRITE))))
+		return -EINVAL;
+
+	/*
+	 * Check if device supports mapping buffers to kernel virtual space.
+	 */
+	if (!q->mem_ops->vaddr)
+		return -EBUSY;
+
+	/*
+	 * Check if streaming api has not been already activated.
+	 */
+	if (q->streaming || q->num_buffers > 0)
+		return -EBUSY;
+
+	/*
+	 * Start with count 1, driver can increase it in queue_setup()
+	 */
+	count = 1;
+
+	dprintk(q, 3, "setting up file io: mode %s, count %d, read_once %d, write_immediately %d\n",
+		(read) ? "read" : "write", count, q->fileio_read_once,
+		q->fileio_write_immediately);
+
+	fileio = kzalloc(sizeof(*fileio), GFP_KERNEL);
+	if (fileio == NULL)
+		return -ENOMEM;
+
+	fileio->read_once = q->fileio_read_once;
+	fileio->write_immediately = q->fileio_write_immediately;
+
+	/*
+	 * Request buffers and use MMAP type to force driver
+	 * to allocate buffers by itself.
+	 */
+	fileio->count = count;
+	fileio->memory = VB2_MEMORY_MMAP;
+	fileio->type = q->type;
+	q->fileio = fileio;
+	ret = vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
+	if (ret)
+		goto err_kfree;
+
+	/*
+	 * Check if plane_count is correct
+	 * (multiplane buffers are not supported).
+	 */
+	if (q->bufs[0]->num_planes != 1) {
+		ret = -EBUSY;
+		goto err_reqbufs;
+	}
+
+	/*
+	 * Get kernel address of each buffer.
+	 */
+	for (i = 0; i < q->num_buffers; i++) {
+		fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
+		if (fileio->bufs[i].vaddr == NULL) {
+			ret = -EINVAL;
+			goto err_reqbufs;
+		}
+		fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
+	}
+
+	/*
+	 * Read mode requires pre queuing of all buffers.
+	 */
+	if (read) {
+		/*
+		 * Queue all buffers.
+		 */
+		for (i = 0; i < q->num_buffers; i++) {
+			ret = vb2_core_qbuf(q, i, NULL, NULL);
+			if (ret)
+				goto err_reqbufs;
+			fileio->bufs[i].queued = 1;
+		}
+		/*
+		 * All buffers have been queued, so mark that by setting
+		 * initial_index to q->num_buffers
+		 */
+		fileio->initial_index = q->num_buffers;
+		fileio->cur_index = q->num_buffers;
+	}
+
+	/*
+	 * Start streaming.
+	 */
+	ret = vb2_core_streamon(q, q->type);
+	if (ret)
+		goto err_reqbufs;
+
+	return ret;
+
+err_reqbufs:
+	fileio->count = 0;
+	vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
+
+err_kfree:
+	q->fileio = NULL;
+	kfree(fileio);
+	return ret;
+}
+
+/*
+ * __vb2_cleanup_fileio() - free resourced used by file io emulator
+ * @q:		videobuf2 queue
+ */
+static int __vb2_cleanup_fileio(struct vb2_queue *q)
+{
+	struct vb2_fileio_data *fileio = q->fileio;
+
+	if (fileio) {
+		vb2_core_streamoff(q, q->type);
+		q->fileio = NULL;
+		fileio->count = 0;
+		vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
+		kfree(fileio);
+		dprintk(q, 3, "file io emulator closed\n");
+	}
+	return 0;
+}
+
+/*
+ * __vb2_perform_fileio() - perform a single file io (read or write) operation
+ * @q:		videobuf2 queue
+ * @data:	pointed to target userspace buffer
+ * @count:	number of bytes to read or write
+ * @ppos:	file handle position tracking pointer
+ * @nonblock:	mode selector (1 means blocking calls, 0 means nonblocking)
+ * @read:	access mode selector (1 means read, 0 means write)
+ */
+static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
+		loff_t *ppos, int nonblock, int read)
+{
+	struct vb2_fileio_data *fileio;
+	struct vb2_fileio_buf *buf;
+	bool is_multiplanar = q->is_multiplanar;
+	/*
+	 * When using write() to write data to an output video node the vb2 core
+	 * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
+	 * else is able to provide this information with the write() operation.
+	 */
+	bool copy_timestamp = !read && q->copy_timestamp;
+	unsigned index;
+	int ret;
+
+	dprintk(q, 3, "mode %s, offset %ld, count %zd, %sblocking\n",
+		read ? "read" : "write", (long)*ppos, count,
+		nonblock ? "non" : "");
+
+	if (!data)
+		return -EINVAL;
+
+	if (q->waiting_in_dqbuf) {
+		dprintk(q, 3, "another dup()ped fd is %s\n",
+			read ? "reading" : "writing");
+		return -EBUSY;
+	}
+
+	/*
+	 * Initialize emulator on first call.
+	 */
+	if (!vb2_fileio_is_active(q)) {
+		ret = __vb2_init_fileio(q, read);
+		dprintk(q, 3, "vb2_init_fileio result: %d\n", ret);
+		if (ret)
+			return ret;
+	}
+	fileio = q->fileio;
+
+	/*
+	 * Check if we need to dequeue the buffer.
+	 */
+	index = fileio->cur_index;
+	if (index >= q->num_buffers) {
+		struct vb2_buffer *b;
+
+		/*
+		 * Call vb2_dqbuf to get buffer back.
+		 */
+		ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
+		dprintk(q, 5, "vb2_dqbuf result: %d\n", ret);
+		if (ret)
+			return ret;
+		fileio->dq_count += 1;
+
+		fileio->cur_index = index;
+		buf = &fileio->bufs[index];
+		b = q->bufs[index];
+
+		/*
+		 * Get number of bytes filled by the driver
+		 */
+		buf->pos = 0;
+		buf->queued = 0;
+		buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
+				 : vb2_plane_size(q->bufs[index], 0);
+		/* Compensate for data_offset on read in the multiplanar case. */
+		if (is_multiplanar && read &&
+				b->planes[0].data_offset < buf->size) {
+			buf->pos = b->planes[0].data_offset;
+			buf->size -= buf->pos;
+		}
+	} else {
+		buf = &fileio->bufs[index];
+	}
+
+	/*
+	 * Limit count on last few bytes of the buffer.
+	 */
+	if (buf->pos + count > buf->size) {
+		count = buf->size - buf->pos;
+		dprintk(q, 5, "reducing read count: %zd\n", count);
+	}
+
+	/*
+	 * Transfer data to userspace.
+	 */
+	dprintk(q, 3, "copying %zd bytes - buffer %d, offset %u\n",
+		count, index, buf->pos);
+	if (read)
+		ret = copy_to_user(data, buf->vaddr + buf->pos, count);
+	else
+		ret = copy_from_user(buf->vaddr + buf->pos, data, count);
+	if (ret) {
+		dprintk(q, 3, "error copying data\n");
+		return -EFAULT;
+	}
+
+	/*
+	 * Update counters.
+	 */
+	buf->pos += count;
+	*ppos += count;
+
+	/*
+	 * Queue next buffer if required.
+	 */
+	if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
+		struct vb2_buffer *b = q->bufs[index];
+
+		/*
+		 * Check if this is the last buffer to read.
+		 */
+		if (read && fileio->read_once && fileio->dq_count == 1) {
+			dprintk(q, 3, "read limit reached\n");
+			return __vb2_cleanup_fileio(q);
+		}
+
+		/*
+		 * Call vb2_qbuf and give buffer to the driver.
+		 */
+		b->planes[0].bytesused = buf->pos;
+
+		if (copy_timestamp)
+			b->timestamp = ktime_get_ns();
+		ret = vb2_core_qbuf(q, index, NULL, NULL);
+		dprintk(q, 5, "vb2_dbuf result: %d\n", ret);
+		if (ret)
+			return ret;
+
+		/*
+		 * Buffer has been queued, update the status
+		 */
+		buf->pos = 0;
+		buf->queued = 1;
+		buf->size = vb2_plane_size(q->bufs[index], 0);
+		fileio->q_count += 1;
+		/*
+		 * If we are queuing up buffers for the first time, then
+		 * increase initial_index by one.
+		 */
+		if (fileio->initial_index < q->num_buffers)
+			fileio->initial_index++;
+		/*
+		 * The next buffer to use is either a buffer that's going to be
+		 * queued for the first time (initial_index < q->num_buffers)
+		 * or it is equal to q->num_buffers, meaning that the next
+		 * time we need to dequeue a buffer since we've now queued up
+		 * all the 'first time' buffers.
+		 */
+		fileio->cur_index = fileio->initial_index;
+	}
+
+	/*
+	 * Return proper number of bytes processed.
+	 */
+	if (ret == 0)
+		ret = count;
+	return ret;
+}
+
+size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
+		loff_t *ppos, int nonblocking)
+{
+	return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
+}
+EXPORT_SYMBOL_GPL(vb2_read);
+
+size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
+		loff_t *ppos, int nonblocking)
+{
+	return __vb2_perform_fileio(q, (char __user *) data, count,
+							ppos, nonblocking, 0);
+}
+EXPORT_SYMBOL_GPL(vb2_write);
+
+struct vb2_threadio_data {
+	struct task_struct *thread;
+	vb2_thread_fnc fnc;
+	void *priv;
+	bool stop;
+};
+
+static int vb2_thread(void *data)
+{
+	struct vb2_queue *q = data;
+	struct vb2_threadio_data *threadio = q->threadio;
+	bool copy_timestamp = false;
+	unsigned prequeue = 0;
+	unsigned index = 0;
+	int ret = 0;
+
+	if (q->is_output) {
+		prequeue = q->num_buffers;
+		copy_timestamp = q->copy_timestamp;
+	}
+
+	set_freezable();
+
+	for (;;) {
+		struct vb2_buffer *vb;
+
+		/*
+		 * Call vb2_dqbuf to get buffer back.
+		 */
+		if (prequeue) {
+			vb = q->bufs[index++];
+			prequeue--;
+		} else {
+			call_void_qop(q, wait_finish, q);
+			if (!threadio->stop)
+				ret = vb2_core_dqbuf(q, &index, NULL, 0);
+			call_void_qop(q, wait_prepare, q);
+			dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
+			if (!ret)
+				vb = q->bufs[index];
+		}
+		if (ret || threadio->stop)
+			break;
+		try_to_freeze();
+
+		if (vb->state != VB2_BUF_STATE_ERROR)
+			if (threadio->fnc(vb, threadio->priv))
+				break;
+		call_void_qop(q, wait_finish, q);
+		if (copy_timestamp)
+			vb->timestamp = ktime_get_ns();
+		if (!threadio->stop)
+			ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
+		call_void_qop(q, wait_prepare, q);
+		if (ret || threadio->stop)
+			break;
+	}
+
+	/* Hmm, linux becomes *very* unhappy without this ... */
+	while (!kthread_should_stop()) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule();
+	}
+	return 0;
+}
+
+/*
+ * This function should not be used for anything else but the videobuf2-dvb
+ * support. If you think you have another good use-case for this, then please
+ * contact the linux-media mailinglist first.
+ */
+int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
+		     const char *thread_name)
+{
+	struct vb2_threadio_data *threadio;
+	int ret = 0;
+
+	if (q->threadio)
+		return -EBUSY;
+	if (vb2_is_busy(q))
+		return -EBUSY;
+	if (WARN_ON(q->fileio))
+		return -EBUSY;
+
+	threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
+	if (threadio == NULL)
+		return -ENOMEM;
+	threadio->fnc = fnc;
+	threadio->priv = priv;
+
+	ret = __vb2_init_fileio(q, !q->is_output);
+	dprintk(q, 3, "file io: vb2_init_fileio result: %d\n", ret);
+	if (ret)
+		goto nomem;
+	q->threadio = threadio;
+	threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
+	if (IS_ERR(threadio->thread)) {
+		ret = PTR_ERR(threadio->thread);
+		threadio->thread = NULL;
+		goto nothread;
+	}
+	return 0;
+
+nothread:
+	__vb2_cleanup_fileio(q);
+nomem:
+	kfree(threadio);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vb2_thread_start);
+
+int vb2_thread_stop(struct vb2_queue *q)
+{
+	struct vb2_threadio_data *threadio = q->threadio;
+	int err;
+
+	if (threadio == NULL)
+		return 0;
+	threadio->stop = true;
+	/* Wake up all pending sleeps in the thread */
+	vb2_queue_error(q);
+	err = kthread_stop(threadio->thread);
+	__vb2_cleanup_fileio(q);
+	threadio->thread = NULL;
+	kfree(threadio);
+	q->threadio = NULL;
+	return err;
+}
+EXPORT_SYMBOL_GPL(vb2_thread_stop);
+
+MODULE_DESCRIPTION("Media buffer core framework");
+MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(DMA_BUF);