1 /*
2 * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 */
13
14 #include <crypto/hash.h>
15 #include <linux/err.h>
16 #include "hash.h"
17
18 static struct crypto_shash *tfm;
19
btrfs_hash_init(void)20 int __init btrfs_hash_init(void)
21 {
22 tfm = crypto_alloc_shash("crc32c", 0, 0);
23
24 return PTR_ERR_OR_ZERO(tfm);
25 }
26
btrfs_crc32c_impl(void)27 const char* btrfs_crc32c_impl(void)
28 {
29 return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
30 }
31
btrfs_hash_exit(void)32 void btrfs_hash_exit(void)
33 {
34 crypto_free_shash(tfm);
35 }
36
btrfs_crc32c(u32 crc,const void * address,unsigned int length)37 u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
38 {
39 SHASH_DESC_ON_STACK(shash, tfm);
40 u32 *ctx = (u32 *)shash_desc_ctx(shash);
41 u32 retval;
42 int err;
43
44 shash->tfm = tfm;
45 shash->flags = 0;
46 *ctx = crc;
47
48 err = crypto_shash_update(shash, address, length);
49 BUG_ON(err);
50
51 retval = *ctx;
52 barrier_data(ctx);
53 return retval;
54 }
55