[deliverable/linux.git] / drivers / media / v4l2-core / videobuf2-dma-contig.c

/*
 * videobuf2-dma-contig.c - DMA contig memory allocator for videobuf2
 *
 * Copyright (C) 2010 Samsung Electronics
 *
 * Author: Pawel Osciak <pawel@osciak.com>
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>

#include <media/videobuf2-core.h>
#include <media/videobuf2-dma-contig.h>
#include <media/videobuf2-memops.h>

struct vb2_dc_conf {
	struct device		*dev;
};

struct vb2_dc_buf {
	struct device			*dev;
	void				*vaddr;
	unsigned long			size;
	dma_addr_t			dma_addr;
	enum dma_data_direction		dma_dir;
	struct sg_table			*dma_sgt;

	/* MMAP related */
	struct vb2_vmarea_handler	handler;
	atomic_t			refcount;

	/* USERPTR related */
	struct vm_area_struct		*vma;
};

/*********************************************/
/*        scatterlist table functions        */
/*********************************************/


static void vb2_dc_sgt_foreach_page(struct sg_table *sgt,
	void (*cb)(struct page *pg))
{
	struct scatterlist *s;
	unsigned int i;

	for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
		struct page *page = sg_page(s);
		unsigned int n_pages = PAGE_ALIGN(s->offset + s->length)
			>> PAGE_SHIFT;
		unsigned int j;

		for (j = 0; j < n_pages; ++j, ++page)
			cb(page);
	}
}

static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
{
	struct scatterlist *s;
	dma_addr_t expected = sg_dma_address(sgt->sgl);
	unsigned int i;
	unsigned long size = 0;

	for_each_sg(sgt->sgl, s, sgt->nents, i) {
		if (sg_dma_address(s) != expected)
			break;
		expected = sg_dma_address(s) + sg_dma_len(s);
		size += sg_dma_len(s);
	}
	return size;
}

/*********************************************/
/*         callbacks for all buffers         */
/*********************************************/

static void *vb2_dc_cookie(void *buf_priv)
{
	struct vb2_dc_buf *buf = buf_priv;

	return &buf->dma_addr;
}

static void *vb2_dc_vaddr(void *buf_priv)
{
	struct vb2_dc_buf *buf = buf_priv;

	return buf->vaddr;
}

static unsigned int vb2_dc_num_users(void *buf_priv)
{
	struct vb2_dc_buf *buf = buf_priv;

	return atomic_read(&buf->refcount);
}

static void vb2_dc_prepare(void *buf_priv)
{
	struct vb2_dc_buf *buf = buf_priv;
	struct sg_table *sgt = buf->dma_sgt;

	if (!sgt)
		return;

	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
}

static void vb2_dc_finish(void *buf_priv)
{
	struct vb2_dc_buf *buf = buf_priv;
	struct sg_table *sgt = buf->dma_sgt;

	if (!sgt)
		return;

	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
}

/*********************************************/
/*        callbacks for MMAP buffers         */
/*********************************************/

static void vb2_dc_put(void *buf_priv)
{
	struct vb2_dc_buf *buf = buf_priv;

	if (!atomic_dec_and_test(&buf->refcount))
		return;

	dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr);
	kfree(buf);
}

static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size)
{
	struct vb2_dc_conf *conf = alloc_ctx;
	struct device *dev = conf->dev;
	struct vb2_dc_buf *buf;

	buf = kzalloc(sizeof *buf, GFP_KERNEL);
	if (!buf)
		return ERR_PTR(-ENOMEM);

	buf->vaddr = dma_alloc_coherent(dev, size, &buf->dma_addr, GFP_KERNEL);
	if (!buf->vaddr) {
		dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size);
		kfree(buf);
		return ERR_PTR(-ENOMEM);
	}

	buf->dev = dev;
	buf->size = size;

	buf->handler.refcount = &buf->refcount;
	buf->handler.put = vb2_dc_put;
	buf->handler.arg = buf;

	atomic_inc(&buf->refcount);

	return buf;
}

static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
{
	struct vb2_dc_buf *buf = buf_priv;

	if (!buf) {
		printk(KERN_ERR "No buffer to map\n");
		return -EINVAL;
	}

	return vb2_mmap_pfn_range(vma, buf->dma_addr, buf->size,
				  &vb2_common_vm_ops, &buf->handler);
}

/*********************************************/
/*       callbacks for USERPTR buffers       */
/*********************************************/

static inline int vma_is_io(struct vm_area_struct *vma)
{
	return !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
}

static int vb2_dc_get_user_pages(unsigned long start, struct page **pages,
	int n_pages, struct vm_area_struct *vma, int write)
{
	if (vma_is_io(vma)) {
		unsigned int i;

		for (i = 0; i < n_pages; ++i, start += PAGE_SIZE) {
			unsigned long pfn;
			int ret = follow_pfn(vma, start, &pfn);

			if (ret) {
				pr_err("no page for address %lu\n", start);
				return ret;
			}
			pages[i] = pfn_to_page(pfn);
		}
	} else {
		int n;

		n = get_user_pages(current, current->mm, start & PAGE_MASK,
			n_pages, write, 1, pages, NULL);
		/* negative error means that no page was pinned */
		n = max(n, 0);
		if (n != n_pages) {
			pr_err("got only %d of %d user pages\n", n, n_pages);
			while (n)
				put_page(pages[--n]);
			return -EFAULT;
		}
	}

	return 0;
}

static void vb2_dc_put_dirty_page(struct page *page)
{
	set_page_dirty_lock(page);
	put_page(page);
}

static void vb2_dc_put_userptr(void *buf_priv)
{
	struct vb2_dc_buf *buf = buf_priv;
	struct sg_table *sgt = buf->dma_sgt;

	dma_unmap_sg(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
	if (!vma_is_io(buf->vma))
		vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page);

	sg_free_table(sgt);
	kfree(sgt);
	vb2_put_vma(buf->vma);
	kfree(buf);
}

static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
	unsigned long size, int write)
{
	struct vb2_dc_conf *conf = alloc_ctx;
	struct vb2_dc_buf *buf;
	unsigned long start;
	unsigned long end;
	unsigned long offset;
	struct page **pages;
	int n_pages;
	int ret = 0;
	struct vm_area_struct *vma;
	struct sg_table *sgt;
	unsigned long contig_size;

	buf = kzalloc(sizeof *buf, GFP_KERNEL);
	if (!buf)
		return ERR_PTR(-ENOMEM);

	buf->dev = conf->dev;
	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;

	start = vaddr & PAGE_MASK;
	offset = vaddr & ~PAGE_MASK;
	end = PAGE_ALIGN(vaddr + size);
	n_pages = (end - start) >> PAGE_SHIFT;

	pages = kmalloc(n_pages * sizeof(pages[0]), GFP_KERNEL);
	if (!pages) {
		ret = -ENOMEM;
		pr_err("failed to allocate pages table\n");
		goto fail_buf;
	}

	/* current->mm->mmap_sem is taken by videobuf2 core */
	vma = find_vma(current->mm, vaddr);
	if (!vma) {
		pr_err("no vma for address %lu\n", vaddr);
		ret = -EFAULT;
		goto fail_pages;
	}

	if (vma->vm_end < vaddr + size) {
		pr_err("vma at %lu is too small for %lu bytes\n", vaddr, size);
		ret = -EFAULT;
		goto fail_pages;
	}

	buf->vma = vb2_get_vma(vma);
	if (!buf->vma) {
		pr_err("failed to copy vma\n");
		ret = -ENOMEM;
		goto fail_pages;
	}

	/* extract page list from userspace mapping */
	ret = vb2_dc_get_user_pages(start, pages, n_pages, vma, write);
	if (ret) {
		pr_err("failed to get user pages\n");
		goto fail_vma;
	}

	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
	if (!sgt) {
		pr_err("failed to allocate sg table\n");
		ret = -ENOMEM;
		goto fail_get_user_pages;
	}

	ret = sg_alloc_table_from_pages(sgt, pages, n_pages,
		offset, size, GFP_KERNEL);
	if (ret) {
		pr_err("failed to initialize sg table\n");
		goto fail_sgt;
	}

	/* pages are no longer needed */
	kfree(pages);
	pages = NULL;

	sgt->nents = dma_map_sg(buf->dev, sgt->sgl, sgt->orig_nents,
		buf->dma_dir);
	if (sgt->nents <= 0) {
		pr_err("failed to map scatterlist\n");
		ret = -EIO;
		goto fail_sgt_init;
	}

	contig_size = vb2_dc_get_contiguous_size(sgt);
	if (contig_size < size) {
		pr_err("contiguous mapping is too small %lu/%lu\n",
			contig_size, size);
		ret = -EFAULT;
		goto fail_map_sg;
	}

	buf->dma_addr = sg_dma_address(sgt->sgl);
	buf->size = size;
	buf->dma_sgt = sgt;

	return buf;

fail_map_sg:
	dma_unmap_sg(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);

fail_sgt_init:
	if (!vma_is_io(buf->vma))
		vb2_dc_sgt_foreach_page(sgt, put_page);
	sg_free_table(sgt);

fail_sgt:
	kfree(sgt);

fail_get_user_pages:
	if (pages && !vma_is_io(buf->vma))
		while (n_pages)
			put_page(pages[--n_pages]);

fail_vma:
	vb2_put_vma(buf->vma);

fail_pages:
	kfree(pages); /* kfree is NULL-proof */

fail_buf:
	kfree(buf);

	return ERR_PTR(ret);
}

/*********************************************/
/*       DMA CONTIG exported functions       */
/*********************************************/

const struct vb2_mem_ops vb2_dma_contig_memops = {
	.alloc		= vb2_dc_alloc,
	.put		= vb2_dc_put,
	.cookie		= vb2_dc_cookie,
	.vaddr		= vb2_dc_vaddr,
	.mmap		= vb2_dc_mmap,
	.get_userptr	= vb2_dc_get_userptr,
	.put_userptr	= vb2_dc_put_userptr,
	.prepare	= vb2_dc_prepare,
	.finish		= vb2_dc_finish,
	.num_users	= vb2_dc_num_users,
};
EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);

void *vb2_dma_contig_init_ctx(struct device *dev)
{
	struct vb2_dc_conf *conf;

	conf = kzalloc(sizeof *conf, GFP_KERNEL);
	if (!conf)
		return ERR_PTR(-ENOMEM);

	conf->dev = dev;

	return conf;
}
EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx);

void vb2_dma_contig_cleanup_ctx(void *alloc_ctx)
{
	kfree(alloc_ctx);
}
EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx);

MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2");
MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
MODULE_LICENSE("GPL");
Commit	Line	Data
1a758d4e PO	1	/*
	2	* videobuf2-dma-contig.c - DMA contig memory allocator for videobuf2
	3	*
	4	* Copyright (C) 2010 Samsung Electronics
	5	*
95072084	6	* Author: Pawel Osciak <pawel@osciak.com>
1a758d4e PO	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation.
	11	*/
	12
	13	#include <linux/module.h>
e15dab75 TS	14	#include <linux/scatterlist.h>
e15dab75 TS	15	#include <linux/sched.h>
1a758d4e PO	16	#include <linux/slab.h>
	17	#include <linux/dma-mapping.h>
	18
	19	#include <media/videobuf2-core.h>
d0df3c38	20	#include <media/videobuf2-dma-contig.h>
1a758d4e PO	21	#include <media/videobuf2-memops.h>
	22
	23	struct vb2_dc_conf {
	24	struct device *dev;
	25	};
	26
	27	struct vb2_dc_buf {
72f86bff	28	struct device *dev;
1a758d4e	29	void *vaddr;
1a758d4e	30	unsigned long size;
40d8b766	31	dma_addr_t dma_addr;
e15dab75 TS	32	enum dma_data_direction dma_dir;
e15dab75 TS	33	struct sg_table *dma_sgt;
40d8b766 LP	34
40d8b766 LP	35	/* MMAP related */
1a758d4e	36	struct vb2_vmarea_handler handler;
40d8b766 LP	37	atomic_t refcount;
	38
	39	/* USERPTR related */
	40	struct vm_area_struct *vma;
1a758d4e PO	41	};
1a758d4e PO	42
e15dab75 TS	43	/*********************************************/
	44	/* scatterlist table functions */
	45	/*********************************************/
	46
	47
	48	static void vb2_dc_sgt_foreach_page(struct sg_table *sgt,
	49	void (cb)(struct page pg))
	50	{
	51	struct scatterlist *s;
	52	unsigned int i;
	53
	54	for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
	55	struct page *page = sg_page(s);
	56	unsigned int n_pages = PAGE_ALIGN(s->offset + s->length)
	57	>> PAGE_SHIFT;
	58	unsigned int j;
	59
	60	for (j = 0; j < n_pages; ++j, ++page)
	61	cb(page);
	62	}
	63	}
	64
	65	static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
	66	{
	67	struct scatterlist *s;
	68	dma_addr_t expected = sg_dma_address(sgt->sgl);
	69	unsigned int i;
	70	unsigned long size = 0;
	71
	72	for_each_sg(sgt->sgl, s, sgt->nents, i) {
	73	if (sg_dma_address(s) != expected)
	74	break;
	75	expected = sg_dma_address(s) + sg_dma_len(s);
	76	size += sg_dma_len(s);
	77	}
	78	return size;
	79	}
	80
40d8b766 LP	81	/*********************************************/
	82	/* callbacks for all buffers */
	83	/*********************************************/
	84
	85	static void vb2_dc_cookie(void buf_priv)
	86	{
	87	struct vb2_dc_buf *buf = buf_priv;
	88
	89	return &buf->dma_addr;
	90	}
	91
	92	static void vb2_dc_vaddr(void buf_priv)
	93	{
	94	struct vb2_dc_buf *buf = buf_priv;
	95
	96	return buf->vaddr;
	97	}
	98
	99	static unsigned int vb2_dc_num_users(void *buf_priv)
	100	{
	101	struct vb2_dc_buf *buf = buf_priv;
	102
	103	return atomic_read(&buf->refcount);
	104	}
	105
199d101e MS	106	static void vb2_dc_prepare(void *buf_priv)
	107	{
	108	struct vb2_dc_buf *buf = buf_priv;
	109	struct sg_table *sgt = buf->dma_sgt;
	110
	111	if (!sgt)
	112	return;
	113
	114	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
	115	}
	116
	117	static void vb2_dc_finish(void *buf_priv)
	118	{
	119	struct vb2_dc_buf *buf = buf_priv;
	120	struct sg_table *sgt = buf->dma_sgt;
	121
	122	if (!sgt)
	123	return;
	124
	125	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
	126	}
	127
40d8b766 LP	128	/*********************************************/
	129	/* callbacks for MMAP buffers */
	130	/*********************************************/
	131
	132	static void vb2_dc_put(void *buf_priv)
	133	{
	134	struct vb2_dc_buf *buf = buf_priv;
	135
	136	if (!atomic_dec_and_test(&buf->refcount))
	137	return;
	138
	139	dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr);
	140	kfree(buf);
	141	}
1a758d4e	142
f7f129ce	143	static void vb2_dc_alloc(void alloc_ctx, unsigned long size)
1a758d4e PO	144	{
1a758d4e PO	145	struct vb2_dc_conf *conf = alloc_ctx;
72f86bff	146	struct device *dev = conf->dev;
1a758d4e PO	147	struct vb2_dc_buf *buf;
	148
	149	buf = kzalloc(sizeof *buf, GFP_KERNEL);
	150	if (!buf)
	151	return ERR_PTR(-ENOMEM);
	152
72f86bff	153	buf->vaddr = dma_alloc_coherent(dev, size, &buf->dma_addr, GFP_KERNEL);
1a758d4e	154	if (!buf->vaddr) {
72f86bff	155	dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size);
1a758d4e PO	156	kfree(buf);
	157	return ERR_PTR(-ENOMEM);
	158	}
	159
72f86bff	160	buf->dev = dev;
1a758d4e PO	161	buf->size = size;
	162
	163	buf->handler.refcount = &buf->refcount;
f7f129ce	164	buf->handler.put = vb2_dc_put;
1a758d4e PO	165	buf->handler.arg = buf;
	166
	167	atomic_inc(&buf->refcount);
	168
	169	return buf;
	170	}
	171
f7f129ce	172	static int vb2_dc_mmap(void buf_priv, struct vm_area_struct vma)
1a758d4e PO	173	{
	174	struct vb2_dc_buf *buf = buf_priv;
	175
	176	if (!buf) {
	177	printk(KERN_ERR "No buffer to map\n");
	178	return -EINVAL;
	179	}
	180
ba7fcb0c	181	return vb2_mmap_pfn_range(vma, buf->dma_addr, buf->size,
1a758d4e PO	182	&vb2_common_vm_ops, &buf->handler);
	183	}
	184
40d8b766 LP	185	/*********************************************/
	186	/* callbacks for USERPTR buffers */
	187	/*********************************************/
	188
e15dab75 TS	189	static inline int vma_is_io(struct vm_area_struct *vma)
	190	{
	191	return !!(vma->vm_flags & (VM_IO \| VM_PFNMAP));
	192	}
	193
	194	static int vb2_dc_get_user_pages(unsigned long start, struct page **pages,
	195	int n_pages, struct vm_area_struct *vma, int write)
	196	{
	197	if (vma_is_io(vma)) {
	198	unsigned int i;
	199
	200	for (i = 0; i < n_pages; ++i, start += PAGE_SIZE) {
	201	unsigned long pfn;
	202	int ret = follow_pfn(vma, start, &pfn);
	203
	204	if (ret) {
	205	pr_err("no page for address %lu\n", start);
	206	return ret;
	207	}
	208	pages[i] = pfn_to_page(pfn);
	209	}
	210	} else {
	211	int n;
	212
	213	n = get_user_pages(current, current->mm, start & PAGE_MASK,
	214	n_pages, write, 1, pages, NULL);
	215	/* negative error means that no page was pinned */
	216	n = max(n, 0);
	217	if (n != n_pages) {
	218	pr_err("got only %d of %d user pages\n", n, n_pages);
	219	while (n)
	220	put_page(pages[--n]);
	221	return -EFAULT;
	222	}
	223	}
	224
	225	return 0;
	226	}
	227
	228	static void vb2_dc_put_dirty_page(struct page *page)
	229	{
	230	set_page_dirty_lock(page);
	231	put_page(page);
	232	}
	233
	234	static void vb2_dc_put_userptr(void *buf_priv)
	235	{
	236	struct vb2_dc_buf *buf = buf_priv;
	237	struct sg_table *sgt = buf->dma_sgt;
	238
	239	dma_unmap_sg(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
	240	if (!vma_is_io(buf->vma))
	241	vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page);
	242
	243	sg_free_table(sgt);
	244	kfree(sgt);
	245	vb2_put_vma(buf->vma);
	246	kfree(buf);
	247	}
	248
f7f129ce	249	static void vb2_dc_get_userptr(void alloc_ctx, unsigned long vaddr,
e15dab75	250	unsigned long size, int write)
1a758d4e	251	{
e15dab75	252	struct vb2_dc_conf *conf = alloc_ctx;
1a758d4e	253	struct vb2_dc_buf *buf;
e15dab75 TS	254	unsigned long start;
	255	unsigned long end;
	256	unsigned long offset;
	257	struct page **pages;
	258	int n_pages;
	259	int ret = 0;
1a758d4e	260	struct vm_area_struct *vma;
e15dab75 TS	261	struct sg_table *sgt;
e15dab75 TS	262	unsigned long contig_size;
1a758d4e PO	263
	264	buf = kzalloc(sizeof *buf, GFP_KERNEL);
	265	if (!buf)
	266	return ERR_PTR(-ENOMEM);
	267
e15dab75 TS	268	buf->dev = conf->dev;
	269	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
	270
	271	start = vaddr & PAGE_MASK;
	272	offset = vaddr & ~PAGE_MASK;
	273	end = PAGE_ALIGN(vaddr + size);
	274	n_pages = (end - start) >> PAGE_SHIFT;
	275
	276	pages = kmalloc(n_pages * sizeof(pages[0]), GFP_KERNEL);
	277	if (!pages) {
	278	ret = -ENOMEM;
	279	pr_err("failed to allocate pages table\n");
	280	goto fail_buf;
	281	}
	282
	283	/* current->mm->mmap_sem is taken by videobuf2 core */
	284	vma = find_vma(current->mm, vaddr);
	285	if (!vma) {
	286	pr_err("no vma for address %lu\n", vaddr);
	287	ret = -EFAULT;
	288	goto fail_pages;
	289	}
	290
	291	if (vma->vm_end < vaddr + size) {
	292	pr_err("vma at %lu is too small for %lu bytes\n", vaddr, size);
	293	ret = -EFAULT;
	294	goto fail_pages;
	295	}
	296
	297	buf->vma = vb2_get_vma(vma);
	298	if (!buf->vma) {
	299	pr_err("failed to copy vma\n");
	300	ret = -ENOMEM;
	301	goto fail_pages;
	302	}
	303
	304	/* extract page list from userspace mapping */
	305	ret = vb2_dc_get_user_pages(start, pages, n_pages, vma, write);
1a758d4e	306	if (ret) {
e15dab75 TS	307	pr_err("failed to get user pages\n");
	308	goto fail_vma;
	309	}
	310
	311	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
	312	if (!sgt) {
	313	pr_err("failed to allocate sg table\n");
	314	ret = -ENOMEM;
	315	goto fail_get_user_pages;
	316	}
	317
	318	ret = sg_alloc_table_from_pages(sgt, pages, n_pages,
	319	offset, size, GFP_KERNEL);
	320	if (ret) {
	321	pr_err("failed to initialize sg table\n");
	322	goto fail_sgt;
	323	}
	324
	325	/* pages are no longer needed */
	326	kfree(pages);
	327	pages = NULL;
	328
	329	sgt->nents = dma_map_sg(buf->dev, sgt->sgl, sgt->orig_nents,
	330	buf->dma_dir);
	331	if (sgt->nents <= 0) {
	332	pr_err("failed to map scatterlist\n");
	333	ret = -EIO;
	334	goto fail_sgt_init;
	335	}
	336
	337	contig_size = vb2_dc_get_contiguous_size(sgt);
	338	if (contig_size < size) {
	339	pr_err("contiguous mapping is too small %lu/%lu\n",
	340	contig_size, size);
	341	ret = -EFAULT;
	342	goto fail_map_sg;
1a758d4e PO	343	}
1a758d4e PO	344
e15dab75	345	buf->dma_addr = sg_dma_address(sgt->sgl);
1a758d4e	346	buf->size = size;
e15dab75	347	buf->dma_sgt = sgt;
1a758d4e PO	348
1a758d4e PO	349	return buf;
1a758d4e	350
e15dab75 TS	351	fail_map_sg:
e15dab75 TS	352	dma_unmap_sg(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
1a758d4e	353
e15dab75 TS	354	fail_sgt_init:
	355	if (!vma_is_io(buf->vma))
	356	vb2_dc_sgt_foreach_page(sgt, put_page);
	357	sg_free_table(sgt);
	358
	359	fail_sgt:
	360	kfree(sgt);
1a758d4e	361
e15dab75 TS	362	fail_get_user_pages:
	363	if (pages && !vma_is_io(buf->vma))
	364	while (n_pages)
	365	put_page(pages[--n_pages]);
	366
	367	fail_vma:
1a758d4e	368	vb2_put_vma(buf->vma);
e15dab75 TS	369
	370	fail_pages:
	371	kfree(pages); /* kfree is NULL-proof */
	372
	373	fail_buf:
1a758d4e	374	kfree(buf);
e15dab75 TS	375
e15dab75 TS	376	return ERR_PTR(ret);
1a758d4e PO	377	}
1a758d4e PO	378
40d8b766 LP	379	/*********************************************/
	380	/* DMA CONTIG exported functions */
	381	/*********************************************/
	382
1a758d4e	383	const struct vb2_mem_ops vb2_dma_contig_memops = {
f7f129ce LP	384	.alloc = vb2_dc_alloc,
	385	.put = vb2_dc_put,
	386	.cookie = vb2_dc_cookie,
	387	.vaddr = vb2_dc_vaddr,
	388	.mmap = vb2_dc_mmap,
	389	.get_userptr = vb2_dc_get_userptr,
	390	.put_userptr = vb2_dc_put_userptr,
199d101e MS	391	.prepare = vb2_dc_prepare,
199d101e MS	392	.finish = vb2_dc_finish,
f7f129ce	393	.num_users = vb2_dc_num_users,
1a758d4e PO	394	};
	395	EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
	396
	397	void vb2_dma_contig_init_ctx(struct device dev)
	398	{
	399	struct vb2_dc_conf *conf;
	400
	401	conf = kzalloc(sizeof *conf, GFP_KERNEL);
	402	if (!conf)
	403	return ERR_PTR(-ENOMEM);
	404
	405	conf->dev = dev;
	406
	407	return conf;
	408	}
	409	EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx);
	410
	411	void vb2_dma_contig_cleanup_ctx(void *alloc_ctx)
	412	{
	413	kfree(alloc_ctx);
	414	}
	415	EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx);
	416
	417	MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2");
95072084	418	MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
1a758d4e	419	MODULE_LICENSE("GPL");