[mirror_ubuntu-artful-kernel.git] / include / crypto / scatterwalk.h

/*
 * Cryptographic scatter and gather helpers.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 * Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com>
 * Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * 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; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#ifndef _CRYPTO_SCATTERWALK_H
#define _CRYPTO_SCATTERWALK_H

#include <asm/kmap_types.h>
#include <crypto/algapi.h>
#include <linux/hardirq.h>
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>

static inline void crypto_yield(u32 flags)
{
	if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
		cond_resched();
}

static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num,
					struct scatterlist *sg2)
{
	sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0);
	sg1[num - 1].page_link &= ~0x02;
	sg1[num - 1].page_link |= 0x01;
}

static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg)
{
	if (sg_is_last(sg))
		return NULL;

	return (++sg)->length ? sg : sg_chain_ptr(sg);
}

static inline void scatterwalk_crypto_chain(struct scatterlist *head,
					    struct scatterlist *sg,
					    int chain, int num)
{
	if (chain) {
		head->length += sg->length;
		sg = scatterwalk_sg_next(sg);
	}

	if (sg)
		scatterwalk_sg_chain(head, num, sg);
	else
		sg_mark_end(head);
}

static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
						struct scatter_walk *walk_out)
{
	return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
		 (int)(walk_in->offset - walk_out->offset));
}

static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
{
	unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
	unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
	return len_this_page > len ? len : len_this_page;
}

static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
					     unsigned int nbytes)
{
	unsigned int len_this_page = scatterwalk_pagelen(walk);
	return nbytes > len_this_page ? len_this_page : nbytes;
}

static inline void scatterwalk_advance(struct scatter_walk *walk,
				       unsigned int nbytes)
{
	walk->offset += nbytes;
}

static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
					       unsigned int alignmask)
{
	return !(walk->offset & alignmask);
}

static inline struct page *scatterwalk_page(struct scatter_walk *walk)
{
	return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
}

static inline void scatterwalk_unmap(void *vaddr)
{
	kunmap_atomic(vaddr);
}

void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
			    size_t nbytes, int out);
void *scatterwalk_map(struct scatter_walk *walk);
void scatterwalk_done(struct scatter_walk *walk, int out, int more);

void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
			      unsigned int start, unsigned int nbytes, int out);

int scatterwalk_bytes_sglen(struct scatterlist *sg, int num_bytes);

#endif  /* _CRYPTO_SCATTERWALK_H */
Commit	Line	Data
1da177e4	1	/*
42c271c6	2	* Cryptographic scatter and gather helpers.
1da177e4 LT	3	*
	4	* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
	5	* Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com>
	6	* Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
42c271c6	7	* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
1da177e4 LT	8	*
	9	* This program is free software; you can redistribute it and/or modify it
	10	* under the terms of the GNU General Public License as published by the Free
	11	* Software Foundation; either version 2 of the License, or (at your option)
	12	* any later version.
	13	*
	14	*/
	15
	16	#ifndef _CRYPTO_SCATTERWALK_H
	17	#define _CRYPTO_SCATTERWALK_H
5c64097a	18
42c271c6 HX	19	#include <asm/kmap_types.h>
	20	#include <crypto/algapi.h>
	21	#include <linux/hardirq.h>
	22	#include <linux/highmem.h>
	23	#include <linux/kernel.h>
1da177e4	24	#include <linux/mm.h>
5c64097a	25	#include <linux/scatterlist.h>
1c5dfe6a	26	#include <linux/sched.h>
1da177e4	27
42c271c6 HX	28	static inline void crypto_yield(u32 flags)
	29	{
	30	if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
	31	cond_resched();
	32	}
1da177e4	33
b2ab4a57 HX	34	static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num,
	35	struct scatterlist *sg2)
	36	{
	37	sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0);
8ec970d8	38	sg1[num - 1].page_link &= ~0x02;
41da8b5a	39	sg1[num - 1].page_link \|= 0x01;
b2ab4a57 HX	40	}
	41
	42	static inline struct scatterlist scatterwalk_sg_next(struct scatterlist sg)
	43	{
8ec970d8 HX	44	if (sg_is_last(sg))
	45	return NULL;
	46
389a5390	47	return (++sg)->length ? sg : sg_chain_ptr(sg);
b2ab4a57 HX	48	}
b2ab4a57 HX	49
079f2f74 SK	50	static inline void scatterwalk_crypto_chain(struct scatterlist *head,
	51	struct scatterlist *sg,
	52	int chain, int num)
	53	{
	54	if (chain) {
	55	head->length += sg->length;
	56	sg = scatterwalk_sg_next(sg);
	57	}
	58
	59	if (sg)
	60	scatterwalk_sg_chain(head, num, sg);
	61	else
	62	sg_mark_end(head);
	63	}
	64
5c64097a HX	65	static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
5c64097a HX	66	struct scatter_walk *walk_out)
1da177e4	67	{
78c2f0b8	68	return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
5c64097a HX	69	(int)(walk_in->offset - walk_out->offset));
	70	}
	71
	72	static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
	73	{
	74	unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
	75	unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
	76	return len_this_page > len ? len : len_this_page;
1da177e4 LT	77	}
1da177e4 LT	78
c774e93e HX	79	static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
c774e93e HX	80	unsigned int nbytes)
1da177e4	81	{
5c64097a HX	82	unsigned int len_this_page = scatterwalk_pagelen(walk);
5c64097a HX	83	return nbytes > len_this_page ? len_this_page : nbytes;
1da177e4 LT	84	}
	85
	86	static inline void scatterwalk_advance(struct scatter_walk *walk,
	87	unsigned int nbytes)
	88	{
1da177e4	89	walk->offset += nbytes;
1da177e4 LT	90	}
1da177e4 LT	91
95477377 HX	92	static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
	93	unsigned int alignmask)
	94	{
	95	return !(walk->offset & alignmask);
	96	}
	97
5c64097a HX	98	static inline struct page scatterwalk_page(struct scatter_walk walk)
5c64097a HX	99	{
78c2f0b8	100	return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
5c64097a HX	101	}
5c64097a HX	102
f0dfc0b0	103	static inline void scatterwalk_unmap(void *vaddr)
5c64097a	104	{
f0dfc0b0	105	kunmap_atomic(vaddr);
5c64097a HX	106	}
5c64097a HX	107
1da177e4	108	void scatterwalk_start(struct scatter_walk walk, struct scatterlist sg);
5c64097a HX	109	void scatterwalk_copychunks(void buf, struct scatter_walk walk,
5c64097a HX	110	size_t nbytes, int out);
f0dfc0b0	111	void scatterwalk_map(struct scatter_walk walk);
1da177e4 LT	112	void scatterwalk_done(struct scatter_walk *walk, int out, int more);
1da177e4 LT	113
5fa0fea2 HX	114	void scatterwalk_map_and_copy(void buf, struct scatterlist sg,
	115	unsigned int start, unsigned int nbytes, int out);
	116
257aff51 JF	117	int scatterwalk_bytes_sglen(struct scatterlist *sg, int num_bytes);
257aff51 JF	118
1da177e4	119	#endif /* _CRYPTO_SCATTERWALK_H */