xref: /spdk/lib/util/crc32.c (revision 552e21cce6cccbf833ed9109827e08337377d7ce)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
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11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
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21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/crc32.h"
35 
36 void
37 spdk_crc32_table_init(struct spdk_crc32_table *table, uint32_t polynomial_reflect)
38 {
39 	int i, j;
40 	uint32_t val;
41 
42 	for (i = 0; i < 256; i++) {
43 		val = i;
44 		for (j = 0; j < 8; j++) {
45 			if (val & 1) {
46 				val = (val >> 1) ^ polynomial_reflect;
47 			} else {
48 				val = (val >> 1);
49 			}
50 		}
51 		table->table[i] = val;
52 	}
53 }
54 
55 uint32_t
56 spdk_crc32_update(const struct spdk_crc32_table *table, const void *buf, size_t len, uint32_t crc)
57 {
58 	const uint8_t *buf_u8 = buf;
59 	size_t i;
60 
61 	for (i = 0; i < len; i++) {
62 		crc = (crc >> 8) ^ table->table[(crc ^ buf_u8[i]) & 0xff];
63 	}
64 
65 	return crc;
66 }
67