RDMA/cxgb4: "cookie" can stay in host endianness
[linux-2.6-block.git] / lib / libcrc32c.c
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1da177e4
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1/*
2 * CRC32C
3 *@Article{castagnoli-crc,
4 * author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
5 * title = {{Optimization of Cyclic Redundancy-Check Codes with 24
6 * and 32 Parity Bits}},
7 * journal = IEEE Transactions on Communication,
8 * year = {1993},
9 * volume = {41},
10 * number = {6},
11 * pages = {},
12 * month = {June},
13 *}
14 * Used by the iSCSI driver, possibly others, and derived from the
15 * the iscsi-crc.c module of the linux-iscsi driver at
16 * http://linux-iscsi.sourceforge.net.
17 *
18 * Following the example of lib/crc32, this function is intended to be
19 * flexible and useful for all users. Modules that currently have their
20 * own crc32c, but hopefully may be able to use this one are:
21 * net/sctp (please add all your doco to here if you change to
22 * use this one!)
23 * <endoflist>
24 *
25 * Copyright (c) 2004 Cisco Systems, Inc.
26 *
27 * This program is free software; you can redistribute it and/or modify it
28 * under the terms of the GNU General Public License as published by the Free
29 * Software Foundation; either version 2 of the License, or (at your option)
30 * any later version.
31 *
32 */
1da177e4 33
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34#include <crypto/hash.h>
35#include <linux/err.h>
36#include <linux/init.h>
37#include <linux/kernel.h>
38#include <linux/module.h>
1da177e4 39
69c35efc 40static struct crypto_shash *tfm;
1da177e4 41
69c35efc 42u32 crc32c(u32 crc, const void *address, unsigned int length)
1da177e4 43{
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44 struct {
45 struct shash_desc shash;
46 char ctx[crypto_shash_descsize(tfm)];
47 } desc;
48 int err;
1da177e4 49
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50 desc.shash.tfm = tfm;
51 desc.shash.flags = 0;
52 *(u32 *)desc.ctx = crc;
1da177e4 53
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54 err = crypto_shash_update(&desc.shash, address, length);
55 BUG_ON(err);
1da177e4 56
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57 return *(u32 *)desc.ctx;
58}
1da177e4 59
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60EXPORT_SYMBOL(crc32c);
61
69c35efc 62static int __init libcrc32c_mod_init(void)
1da177e4 63{
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64 tfm = crypto_alloc_shash("crc32c", 0, 0);
65 if (IS_ERR(tfm))
66 return PTR_ERR(tfm);
1da177e4 67
69c35efc 68 return 0;
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69}
70
69c35efc 71static void __exit libcrc32c_mod_fini(void)
1da177e4 72{
69c35efc 73 crypto_free_shash(tfm);
1da177e4 74}
1da177e4 75
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76module_init(libcrc32c_mod_init);
77module_exit(libcrc32c_mod_fini);
78
79MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
80MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations");
81MODULE_LICENSE("GPL");