xref: /spdk/lib/util/crc32.c (revision 22898a91b9b6f289933db19b0175821cfb7e7820)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (C) 2008-2012 Daisuke Aoyama <aoyama@peach.ne.jp>.
5  *   Copyright (c) Intel Corporation.
6  *   All rights reserved.
7  *
8  *   Redistribution and use in source and binary forms, with or without
9  *   modification, are permitted provided that the following conditions
10  *   are met:
11  *
12  *     * Redistributions of source code must retain the above copyright
13  *       notice, this list of conditions and the following disclaimer.
14  *     * Redistributions in binary form must reproduce the above copyright
15  *       notice, this list of conditions and the following disclaimer in
16  *       the documentation and/or other materials provided with the
17  *       distribution.
18  *     * Neither the name of Intel Corporation nor the names of its
19  *       contributors may be used to endorse or promote products derived
20  *       from this software without specific prior written permission.
21  *
22  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include "spdk/crc32.h"
36 
37 void
38 spdk_crc32_table_init(struct spdk_crc32_table *table, uint32_t polynomial_reflect)
39 {
40 	int i, j;
41 	uint32_t val;
42 
43 	for (i = 0; i < 256; i++) {
44 		val = i;
45 		for (j = 0; j < 8; j++) {
46 			if (val & 1) {
47 				val = (val >> 1) ^ polynomial_reflect;
48 			} else {
49 				val = (val >> 1);
50 			}
51 		}
52 		table->table[i] = val;
53 	}
54 }
55 
56 uint32_t
57 spdk_crc32_update(const struct spdk_crc32_table *table, const void *buf, size_t len, uint32_t crc)
58 {
59 	const uint8_t *buf_u8 = buf;
60 	size_t i;
61 
62 	for (i = 0; i < len; i++) {
63 		crc = (crc >> 8) ^ table->table[(crc ^ buf_u8[i]) & 0xff];
64 	}
65 
66 	return crc;
67 }
68