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
18static struct crypto_shash *tfm;
19
20int __init btrfs_hash_init(void)
21{
22	tfm = crypto_alloc_shash("crc32c", 0, 0);
23
24	return PTR_ERR_OR_ZERO(tfm);
25}
26
27const char* btrfs_crc32c_impl(void)
28{
29	return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
30}
31
32void btrfs_hash_exit(void)
33{
34	crypto_free_shash(tfm);
35}
36
37u32 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	int err;
42
43	shash->tfm = tfm;
44	shash->flags = 0;
45	*ctx = crc;
46
47	err = crypto_shash_update(shash, address, length);
48	BUG_ON(err);
49
50	return *ctx;
51}