crypto: sha512 - Export struct sha512_state
[linux-2.6.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 #include <linux/sched.h>
27
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 }
55
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);
60         sg1[num - 1].page_link &= ~0x02;
61 }
62
63 static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg)
64 {
65         if (sg_is_last(sg))
66                 return NULL;
67
68         return (++sg)->length ? sg : (void *)sg_page(sg);
69 }
70
71 static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
72                                                 struct scatter_walk *walk_out)
73 {
74         return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
75                  (int)(walk_in->offset - walk_out->offset));
76 }
77
78 static 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;
83 }
84
85 static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
86                                              unsigned int nbytes)
87 {
88         unsigned int len_this_page = scatterwalk_pagelen(walk);
89         return nbytes > len_this_page ? len_this_page : nbytes;
90 }
91
92 static inline void scatterwalk_advance(struct scatter_walk *walk,
93                                        unsigned int nbytes)
94 {
95         walk->offset += nbytes;
96 }
97
98 static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
99                                                unsigned int alignmask)
100 {
101         return !(walk->offset & alignmask);
102 }
103
104 static inline struct page *scatterwalk_page(struct scatter_walk *walk)
105 {
106         return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
107 }
108
109 static inline void scatterwalk_unmap(void *vaddr, int out)
110 {
111         crypto_kunmap(vaddr, out);
112 }
113
114 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
115 void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
116                             size_t nbytes, int out);
117 void *scatterwalk_map(struct scatter_walk *walk, int out);
118 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
119
120 void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
121                               unsigned int start, unsigned int nbytes, int out);
122
123 #endif  /* _CRYPTO_SCATTERWALK_H */