tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
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
18#include <linux/mm.h>
19#include <linux/scatterlist.h>
20
21#include "internal.h"
22
23static inline struct scatterlist *sg_next(struct scatterlist *sg)
24{
25 return (++sg)->length ? sg : (void *)sg->page;
26}
27
28static 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
35static 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
42static 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
49static inline void scatterwalk_advance(struct scatter_walk *walk,
50 unsigned int nbytes)
51{
52 walk->offset += nbytes;
53}
54
55static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
56 unsigned int alignmask)
57{
58 return !(walk->offset & alignmask);
59}
60
61static inline struct page *scatterwalk_page(struct scatter_walk *walk)
62{
63 return walk->sg->page + (walk->offset >> PAGE_SHIFT);
64}
65
66static inline void scatterwalk_unmap(void *vaddr, int out)
67{
68 crypto_kunmap(vaddr, out);
69}
70
71void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
72void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
73 size_t nbytes, int out);
74void *scatterwalk_map(struct scatter_walk *walk, int out);
75void scatterwalk_done(struct scatter_walk *walk, int out, int more);
76
77#endif /* _CRYPTO_SCATTERWALK_H */