[CRYPTO] scatterwalk: Move scatterwalk.h to linux/crypto
[linux-3.10.git] / include / crypto / scatterwalk.h
1 /*
2  * Cryptographic scatter and gather helpers.
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>
7  * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
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
18
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>
24 #include <linux/mm.h>
25 #include <linux/scatterlist.h>
26
27 static inline enum km_type crypto_kmap_type(int out)
28 {
29         enum km_type type;
30
31         if (in_softirq())
32                 type = out * (KM_SOFTIRQ1 - KM_SOFTIRQ0) + KM_SOFTIRQ0;
33         else
34                 type = out * (KM_USER1 - KM_USER0) + KM_USER0;
35
36         return type;
37 }
38
39 static inline void *crypto_kmap(struct page *page, int out)
40 {
41         return kmap_atomic(page, crypto_kmap_type(out));
42 }
43
44 static inline void crypto_kunmap(void *vaddr, int out)
45 {
46         kunmap_atomic(vaddr, crypto_kmap_type(out));
47 }
48
49 static inline void crypto_yield(u32 flags)
50 {
51         if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
52                 cond_resched();
53 }
54
55 static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
56                                                 struct scatter_walk *walk_out)
57 {
58         return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
59                  (int)(walk_in->offset - walk_out->offset));
60 }
61
62 static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
63 {
64         unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
65         unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
66         return len_this_page > len ? len : len_this_page;
67 }
68
69 static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
70                                              unsigned int nbytes)
71 {
72         unsigned int len_this_page = scatterwalk_pagelen(walk);
73         return nbytes > len_this_page ? len_this_page : nbytes;
74 }
75
76 static inline void scatterwalk_advance(struct scatter_walk *walk,
77                                        unsigned int nbytes)
78 {
79         walk->offset += nbytes;
80 }
81
82 static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
83                                                unsigned int alignmask)
84 {
85         return !(walk->offset & alignmask);
86 }
87
88 static inline struct page *scatterwalk_page(struct scatter_walk *walk)
89 {
90         return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
91 }
92
93 static inline void scatterwalk_unmap(void *vaddr, int out)
94 {
95         crypto_kunmap(vaddr, out);
96 }
97
98 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
99 void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
100                             size_t nbytes, int out);
101 void *scatterwalk_map(struct scatter_walk *walk, int out);
102 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
103
104 void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
105                               unsigned int start, unsigned int nbytes, int out);
106
107 #endif  /* _CRYPTO_SCATTERWALK_H */