[linux-2.6-block.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 enum km_type crypto_kmap_type(int out)
{
	enum km_type type;

	if (in_softirq())
		type = out * (KM_SOFTIRQ1 - KM_SOFTIRQ0) + KM_SOFTIRQ0;
	else
		type = out * (KM_USER1 - KM_USER0) + KM_USER0;

	return type;
}

static inline void *crypto_kmap(struct page *page, int out)
{
	return kmap_atomic(page, crypto_kmap_type(out));
}

static inline void crypto_kunmap(void *vaddr, int out)
{
	kunmap_atomic(vaddr, crypto_kmap_type(out));
}

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;
}

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

	return (++sg)->length ? sg : (void *)sg_page(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, int out)
{
	crypto_kunmap(vaddr, out);
}

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, int out);
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);

#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 enum km_type crypto_kmap_type(int out)
	29	{
	30	enum km_type type;
	31
	32	if (in_softirq())
	33	type = out * (KM_SOFTIRQ1 - KM_SOFTIRQ0) + KM_SOFTIRQ0;
	34	else
	35	type = out * (KM_USER1 - KM_USER0) + KM_USER0;
	36
	37	return type;
	38	}
	39
	40	static inline void crypto_kmap(struct page page, int out)
	41	{
	42	return kmap_atomic(page, crypto_kmap_type(out));
	43	}
	44
	45	static inline void crypto_kunmap(void *vaddr, int out)
	46	{
	47	kunmap_atomic(vaddr, crypto_kmap_type(out));
	48	}
	49
	50	static inline void crypto_yield(u32 flags)
	51	{
	52	if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
	53	cond_resched();
	54	}
1da177e4	55
b2ab4a57 HX	56	static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num,
	57	struct scatterlist *sg2)
	58	{
	59	sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0);
8ec970d8	60	sg1[num - 1].page_link &= ~0x02;
b2ab4a57 HX	61	}
	62
	63	static inline struct scatterlist scatterwalk_sg_next(struct scatterlist sg)
	64	{
8ec970d8 HX	65	if (sg_is_last(sg))
	66	return NULL;
	67
b2ab4a57 HX	68	return (++sg)->length ? sg : (void *)sg_page(sg);
	69	}
	70
079f2f74 SK	71	static inline void scatterwalk_crypto_chain(struct scatterlist *head,
	72	struct scatterlist *sg,
	73	int chain, int num)
	74	{
	75	if (chain) {
	76	head->length += sg->length;
	77	sg = scatterwalk_sg_next(sg);
	78	}
	79
	80	if (sg)
	81	scatterwalk_sg_chain(head, num, sg);
	82	else
	83	sg_mark_end(head);
	84	}
	85
5c64097a HX	86	static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
5c64097a HX	87	struct scatter_walk *walk_out)
1da177e4	88	{
78c2f0b8	89	return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
5c64097a HX	90	(int)(walk_in->offset - walk_out->offset));
	91	}
	92
	93	static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
	94	{
	95	unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
	96	unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
	97	return len_this_page > len ? len : len_this_page;
1da177e4 LT	98	}
1da177e4 LT	99
c774e93e HX	100	static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
c774e93e HX	101	unsigned int nbytes)
1da177e4	102	{
5c64097a HX	103	unsigned int len_this_page = scatterwalk_pagelen(walk);
5c64097a HX	104	return nbytes > len_this_page ? len_this_page : nbytes;
1da177e4 LT	105	}
	106
	107	static inline void scatterwalk_advance(struct scatter_walk *walk,
	108	unsigned int nbytes)
	109	{
1da177e4	110	walk->offset += nbytes;
1da177e4 LT	111	}
1da177e4 LT	112
95477377 HX	113	static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
	114	unsigned int alignmask)
	115	{
	116	return !(walk->offset & alignmask);
	117	}
	118
5c64097a HX	119	static inline struct page scatterwalk_page(struct scatter_walk walk)
5c64097a HX	120	{
78c2f0b8	121	return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
5c64097a HX	122	}
	123
	124	static inline void scatterwalk_unmap(void *vaddr, int out)
	125	{
	126	crypto_kunmap(vaddr, out);
	127	}
	128
1da177e4	129	void scatterwalk_start(struct scatter_walk walk, struct scatterlist sg);
5c64097a HX	130	void scatterwalk_copychunks(void buf, struct scatter_walk walk,
	131	size_t nbytes, int out);
	132	void scatterwalk_map(struct scatter_walk walk, int out);
1da177e4 LT	133	void scatterwalk_done(struct scatter_walk *walk, int out, int more);
1da177e4 LT	134
5fa0fea2 HX	135	void scatterwalk_map_and_copy(void buf, struct scatterlist sg,
	136	unsigned int start, unsigned int nbytes, int out);
	137
1da177e4	138	#endif /* _CRYPTO_SCATTERWALK_H */