[ALSA] cmipci: fix version 37 detection
[linux-2.6.git] / crypto / scatterwalk.h
1 /*
2  * Cryptographic API.
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  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the Free
10  * Software Foundation; either version 2 of the License, or (at your option)
11  * any later version.
12  *
13  */
14
15 #ifndef _CRYPTO_SCATTERWALK_H
16 #define _CRYPTO_SCATTERWALK_H
17
18 #include <linux/mm.h>
19 #include <linux/scatterlist.h>
20
21 #include "internal.h"
22
23 static inline struct scatterlist *sg_next(struct scatterlist *sg)
24 {
25         return (++sg)->length ? sg : (void *)sg->page;
26 }
27
28 static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
29                                                 struct scatter_walk *walk_out)
30 {
31         return !(((walk_in->sg->page - walk_out->sg->page) << PAGE_SHIFT) +
32                  (int)(walk_in->offset - walk_out->offset));
33 }
34
35 static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
36 {
37         unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
38         unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
39         return len_this_page > len ? len : len_this_page;
40 }
41
42 static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
43                                              unsigned int nbytes)
44 {
45         unsigned int len_this_page = scatterwalk_pagelen(walk);
46         return nbytes > len_this_page ? len_this_page : nbytes;
47 }
48
49 static inline void scatterwalk_advance(struct scatter_walk *walk,
50                                        unsigned int nbytes)
51 {
52         walk->offset += nbytes;
53 }
54
55 static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
56                                                unsigned int alignmask)
57 {
58         return !(walk->offset & alignmask);
59 }
60
61 static inline struct page *scatterwalk_page(struct scatter_walk *walk)
62 {
63         return walk->sg->page + (walk->offset >> PAGE_SHIFT);
64 }
65
66 static inline void scatterwalk_unmap(void *vaddr, int out)
67 {
68         crypto_kunmap(vaddr, out);
69 }
70
71 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
72 void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
73                             size_t nbytes, int out);
74 void *scatterwalk_map(struct scatter_walk *walk, int out);
75 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
76
77 void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
78                               unsigned int start, unsigned int nbytes, int out);
79
80 #endif  /* _CRYPTO_SCATTERWALK_H */