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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Herbert Xu42c271c2007-12-07 18:52:49 +08002 * Cryptographic scatter and gather helpers.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
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>
Herbert Xu42c271c2007-12-07 18:52:49 +08007 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
Herbert Xu42c271c2007-12-07 18:52:49 +080019#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>
Herbert Xu5c640972006-08-12 21:56:17 +100024#include <linux/mm.h>
25#include <linux/scatterlist.h>
Herbert Xu1c5dfe62007-12-24 08:54:24 +080026#include <linux/sched.h>
Herbert Xu5c640972006-08-12 21:56:17 +100027
Herbert Xu42c271c2007-12-07 18:52:49 +080028static 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
40static inline void *crypto_kmap(struct page *page, int out)
41{
42 return kmap_atomic(page, crypto_kmap_type(out));
43}
44
45static inline void crypto_kunmap(void *vaddr, int out)
46{
47 kunmap_atomic(vaddr, crypto_kmap_type(out));
48}
49
50static inline void crypto_yield(u32 flags)
51{
52 if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
53 cond_resched();
54}
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Herbert Xub2ab4a52007-12-05 20:59:25 +110056static 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);
Herbert Xu8ec970d2008-04-29 21:53:52 +080060 sg1[num - 1].page_link &= ~0x02;
Herbert Xub2ab4a52007-12-05 20:59:25 +110061}
62
63static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg)
64{
Herbert Xu8ec970d2008-04-29 21:53:52 +080065 if (sg_is_last(sg))
66 return NULL;
67
Herbert Xub2ab4a52007-12-05 20:59:25 +110068 return (++sg)->length ? sg : (void *)sg_page(sg);
69}
70
Herbert Xu5c640972006-08-12 21:56:17 +100071static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
72 struct scatter_walk *walk_out)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073{
Jens Axboe78c2f0b2007-10-22 19:40:16 +020074 return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
Herbert Xu5c640972006-08-12 21:56:17 +100075 (int)(walk_in->offset - walk_out->offset));
76}
77
78static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
79{
80 unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
81 unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
82 return len_this_page > len ? len : len_this_page;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083}
84
Herbert Xuc774e932005-07-06 13:51:31 -070085static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
86 unsigned int nbytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
Herbert Xu5c640972006-08-12 21:56:17 +100088 unsigned int len_this_page = scatterwalk_pagelen(walk);
89 return nbytes > len_this_page ? len_this_page : nbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090}
91
92static inline void scatterwalk_advance(struct scatter_walk *walk,
93 unsigned int nbytes)
94{
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 walk->offset += nbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096}
97
Herbert Xu95477372005-07-06 13:52:09 -070098static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
99 unsigned int alignmask)
100{
101 return !(walk->offset & alignmask);
102}
103
Herbert Xu5c640972006-08-12 21:56:17 +1000104static inline struct page *scatterwalk_page(struct scatter_walk *walk)
105{
Jens Axboe78c2f0b2007-10-22 19:40:16 +0200106 return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
Herbert Xu5c640972006-08-12 21:56:17 +1000107}
108
109static inline void scatterwalk_unmap(void *vaddr, int out)
110{
111 crypto_kunmap(vaddr, out);
112}
113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
Herbert Xu5c640972006-08-12 21:56:17 +1000115void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
116 size_t nbytes, int out);
117void *scatterwalk_map(struct scatter_walk *walk, int out);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118void scatterwalk_done(struct scatter_walk *walk, int out, int more);
119
Herbert Xu5fa0fea2007-08-29 16:31:34 +0800120void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
121 unsigned int start, unsigned int nbytes, int out);
122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123#endif /* _CRYPTO_SCATTERWALK_H */