Blame view
crypto/scatterwalk.c
2.93 KB
1da177e4c Linux-2.6.12-rc2 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
/* * Cryptographic API. * * Cipher operations. * * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> * 2002 Adam J. Richter <adam@yggdrasil.com> * 2004 Jean-Luc Cooke <jlcooke@certainkey.com> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * */ |
42c271c6c [CRYPTO] scatterw... |
16 17 |
#include <crypto/scatterwalk.h> |
1da177e4c Linux-2.6.12-rc2 |
18 19 |
#include <linux/kernel.h> #include <linux/mm.h> |
5c64097aa [CRYPTO] scatterw... |
20 |
#include <linux/module.h> |
1da177e4c Linux-2.6.12-rc2 |
21 22 |
#include <linux/pagemap.h> #include <linux/highmem.h> |
5c64097aa [CRYPTO] scatterw... |
23 |
#include <linux/scatterlist.h> |
5c64097aa [CRYPTO] scatterw... |
24 |
static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out) |
1da177e4c Linux-2.6.12-rc2 |
25 |
{ |
5c64097aa [CRYPTO] scatterw... |
26 27 28 29 |
void *src = out ? buf : sgdata; void *dst = out ? sgdata : buf; memcpy(dst, src, nbytes); |
1da177e4c Linux-2.6.12-rc2 |
30 31 32 33 |
} void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg) { |
1da177e4c Linux-2.6.12-rc2 |
34 |
walk->sg = sg; |
1da177e4c Linux-2.6.12-rc2 |
35 |
BUG_ON(!sg->length); |
1da177e4c Linux-2.6.12-rc2 |
36 37 |
walk->offset = sg->offset; } |
5c64097aa [CRYPTO] scatterw... |
38 |
EXPORT_SYMBOL_GPL(scatterwalk_start); |
1da177e4c Linux-2.6.12-rc2 |
39 |
|
5c64097aa [CRYPTO] scatterw... |
40 |
void *scatterwalk_map(struct scatter_walk *walk, int out) |
1da177e4c Linux-2.6.12-rc2 |
41 |
{ |
5c64097aa [CRYPTO] scatterw... |
42 43 |
return crypto_kmap(scatterwalk_page(walk), out) + offset_in_page(walk->offset); |
1da177e4c Linux-2.6.12-rc2 |
44 |
} |
5c64097aa [CRYPTO] scatterw... |
45 |
EXPORT_SYMBOL_GPL(scatterwalk_map); |
1da177e4c Linux-2.6.12-rc2 |
46 47 48 49 |
static void scatterwalk_pagedone(struct scatter_walk *walk, int out, unsigned int more) { |
9f1167272 [CRYPTO] api: Flu... |
50 51 |
if (out) { struct page *page; |
78c2f0b8c [SG] Update crypt... |
52 |
page = sg_page(walk->sg) + ((walk->offset - 1) >> PAGE_SHIFT); |
4f3e797ad crypto: scatterwa... |
53 54 |
if (!PageSlab(page)) flush_dcache_page(page); |
9f1167272 [CRYPTO] api: Flu... |
55 |
} |
1da177e4c Linux-2.6.12-rc2 |
56 57 |
if (more) { |
5c64097aa [CRYPTO] scatterw... |
58 59 60 |
walk->offset += PAGE_SIZE - 1; walk->offset &= PAGE_MASK; if (walk->offset >= walk->sg->offset + walk->sg->length) |
b2ab4a57b [CRYPTO] scatterw... |
61 |
scatterwalk_start(walk, scatterwalk_sg_next(walk->sg)); |
1da177e4c Linux-2.6.12-rc2 |
62 63 64 65 66 |
} } void scatterwalk_done(struct scatter_walk *walk, int out, int more) { |
5c64097aa [CRYPTO] scatterw... |
67 |
if (!offset_in_page(walk->offset) || !more) |
1da177e4c Linux-2.6.12-rc2 |
68 69 |
scatterwalk_pagedone(walk, out, more); } |
5c64097aa [CRYPTO] scatterw... |
70 |
EXPORT_SYMBOL_GPL(scatterwalk_done); |
1da177e4c Linux-2.6.12-rc2 |
71 |
|
5c64097aa [CRYPTO] scatterw... |
72 73 |
void scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out) |
1da177e4c Linux-2.6.12-rc2 |
74 |
{ |
5c64097aa [CRYPTO] scatterw... |
75 76 77 78 79 80 81 82 83 84 |
for (;;) { unsigned int len_this_page = scatterwalk_pagelen(walk); u8 *vaddr; if (len_this_page > nbytes) len_this_page = nbytes; vaddr = scatterwalk_map(walk, out); memcpy_dir(buf, vaddr, len_this_page, out); scatterwalk_unmap(vaddr, out); |
4ee531a3e [CRYPTO] api: Use... |
85 |
scatterwalk_advance(walk, len_this_page); |
f70ee5ec8 [CRYPTO] api: sca... |
86 |
|
5c64097aa [CRYPTO] scatterw... |
87 88 89 90 91 |
if (nbytes == len_this_page) break; buf += len_this_page; nbytes -= len_this_page; |
1da177e4c Linux-2.6.12-rc2 |
92 |
|
1da177e4c Linux-2.6.12-rc2 |
93 |
scatterwalk_pagedone(walk, out, 1); |
c774e93e2 [CRYPTO] Add plum... |
94 |
} |
1da177e4c Linux-2.6.12-rc2 |
95 |
} |
5c64097aa [CRYPTO] scatterw... |
96 |
EXPORT_SYMBOL_GPL(scatterwalk_copychunks); |
5fa0fea27 [CRYPTO] scatterw... |
97 98 99 100 101 102 |
void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg, unsigned int start, unsigned int nbytes, int out) { struct scatter_walk walk; unsigned int offset = 0; |
6e050778c [CRYPTO] scatterw... |
103 104 |
if (!nbytes) return; |
5fa0fea27 [CRYPTO] scatterw... |
105 106 107 108 109 110 111 |
for (;;) { scatterwalk_start(&walk, sg); if (start < offset + sg->length) break; offset += sg->length; |
b2ab4a57b [CRYPTO] scatterw... |
112 |
sg = scatterwalk_sg_next(sg); |
5fa0fea27 [CRYPTO] scatterw... |
113 114 115 116 117 118 119 |
} scatterwalk_advance(&walk, start - offset); scatterwalk_copychunks(buf, &walk, nbytes, out); scatterwalk_done(&walk, out, 0); } EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy); |