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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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#include <linux/mm.h>
18#include <asm/scatterlist.h>
19
20struct scatter_walk {
21 struct scatterlist *sg;
22 struct page *page;
23 void *data;
24 unsigned int len_this_page;
25 unsigned int len_this_segment;
26 unsigned int offset;
27};
28
29/* Define sg_next is an inline routine now in case we want to change
30 scatterlist to a linked list later. */
31static inline struct scatterlist *sg_next(struct scatterlist *sg)
32{
33 return sg + 1;
34}
35
36static inline int scatterwalk_samebuf(struct scatter_walk *walk_in,
37 struct scatter_walk *walk_out)
38{
39 return walk_in->page == walk_out->page &&
40 walk_in->offset == walk_out->offset;
41}
42
43static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
44 unsigned int nbytes)
45{
46 return nbytes > walk->len_this_page ? walk->len_this_page : nbytes;
47}
48
49static inline void scatterwalk_advance(struct scatter_walk *walk,
50 unsigned int nbytes)
51{
52 walk->data += nbytes;
53 walk->offset += nbytes;
54 walk->len_this_page -= nbytes;
55 walk->len_this_segment -= nbytes;
56}
57
58static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
59 unsigned int alignmask)
60{
61 return !(walk->offset & alignmask);
62}
63
64void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
65int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out);
66void scatterwalk_map(struct scatter_walk *walk, int out);
67void scatterwalk_done(struct scatter_walk *walk, int out, int more);
68
69#endif /* _CRYPTO_SCATTERWALK_H */