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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070017
Herbert Xu5c640972006-08-12 21:56:17 +100018#include <linux/mm.h>
19#include <linux/scatterlist.h>
20
21#include "internal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
Jens Axboeab834072007-05-09 08:58:32 +020023static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070024{
Herbert Xu055bcee2006-08-19 22:24:23 +100025 return (++sg)->length ? sg : (void *)sg->page;
Linus Torvalds1da177e2005-04-16 15:20:36 -070026}
27
Herbert Xu5c640972006-08-12 21:56:17 +100028static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
29 struct scatter_walk *walk_out)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030{
Herbert Xu5c640972006-08-12 21:56:17 +100031 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040}
41
Herbert Xuc774e932005-07-06 13:51:31 -070042static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
43 unsigned int nbytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -070044{
Herbert Xu5c640972006-08-12 21:56:17 +100045 unsigned int len_this_page = scatterwalk_pagelen(walk);
46 return nbytes > len_this_page ? len_this_page : nbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047}
48
49static inline void scatterwalk_advance(struct scatter_walk *walk,
50 unsigned int nbytes)
51{
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 walk->offset += nbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053}
54
Herbert Xu95477372005-07-06 13:52:09 -070055static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
56 unsigned int alignmask)
57{
58 return !(walk->offset & alignmask);
59}
60
Herbert Xu5c640972006-08-12 21:56:17 +100061static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070071void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
Herbert Xu5c640972006-08-12 21:56:17 +100072void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
73 size_t nbytes, int out);
74void *scatterwalk_map(struct scatter_walk *walk, int out);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075void scatterwalk_done(struct scatter_walk *walk, int out, int more);
76
Herbert Xu5fa0fea2007-08-29 16:31:34 +080077void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
78 unsigned int start, unsigned int nbytes, int out);
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080#endif /* _CRYPTO_SCATTERWALK_H */