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 27void btrfs_hash_exit(void) 28{ 29 crypto_free_shash(tfm); 30} 31 32u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length) 33{ 34 SHASH_DESC_ON_STACK(shash, tfm); 35 u32 *ctx = (u32 *)shash_desc_ctx(shash); 36 int err; 37 38 shash->tfm = tfm; 39 shash->flags = 0; 40 *ctx = crc; 41 42 err = crypto_shash_update(shash, address, length); 43 BUG_ON(err); 44 45 return *ctx; 46} 47