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7e280e68 DC |
1 | #include <stdio.h> |
2 | #include "crc32defs.h" | |
3 | #include <inttypes.h> | |
4 | ||
5 | #define ENTRIES_PER_LINE 4 | |
6 | ||
7 | #if CRC_LE_BITS > 8 | |
8 | # define LE_TABLE_ROWS (CRC_LE_BITS/8) | |
9 | # define LE_TABLE_SIZE 256 | |
10 | #else | |
11 | # define LE_TABLE_ROWS 1 | |
12 | # define LE_TABLE_SIZE (1 << CRC_LE_BITS) | |
13 | #endif | |
14 | ||
15 | #if CRC_BE_BITS > 8 | |
16 | # define BE_TABLE_ROWS (CRC_BE_BITS/8) | |
17 | # define BE_TABLE_SIZE 256 | |
18 | #else | |
19 | # define BE_TABLE_ROWS 1 | |
20 | # define BE_TABLE_SIZE (1 << CRC_BE_BITS) | |
21 | #endif | |
22 | ||
23 | static uint32_t crc32table_le[LE_TABLE_ROWS][256]; | |
24 | static uint32_t crc32ctable_le[LE_TABLE_ROWS][256]; | |
25 | ||
26 | /* | |
27 | * big endian ordered CRC not used by XFS. | |
28 | static uint32_t crc32table_be[BE_TABLE_ROWS][256]; | |
29 | */ | |
30 | ||
31 | /** | |
32 | * crc32init_le() - allocate and initialize LE table data | |
33 | * | |
34 | * crc is the crc of the byte i; other entries are filled in based on the | |
35 | * fact that crctable[i^j] = crctable[i] ^ crctable[j]. | |
36 | * | |
37 | */ | |
38 | static void crc32init_le_generic(const uint32_t polynomial, | |
39 | uint32_t (*tab)[256]) | |
40 | { | |
41 | unsigned i, j; | |
42 | uint32_t crc = 1; | |
43 | ||
44 | tab[0][0] = 0; | |
45 | ||
46 | for (i = LE_TABLE_SIZE >> 1; i; i >>= 1) { | |
47 | crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0); | |
48 | for (j = 0; j < LE_TABLE_SIZE; j += 2 * i) | |
49 | tab[0][i + j] = crc ^ tab[0][j]; | |
50 | } | |
51 | for (i = 0; i < LE_TABLE_SIZE; i++) { | |
52 | crc = tab[0][i]; | |
53 | for (j = 1; j < LE_TABLE_ROWS; j++) { | |
54 | crc = tab[0][crc & 0xff] ^ (crc >> 8); | |
55 | tab[j][i] = crc; | |
56 | } | |
57 | } | |
58 | } | |
59 | ||
60 | static void crc32init_le(void) | |
61 | { | |
62 | crc32init_le_generic(CRCPOLY_LE, crc32table_le); | |
63 | } | |
64 | ||
65 | static void crc32cinit_le(void) | |
66 | { | |
67 | crc32init_le_generic(CRC32C_POLY_LE, crc32ctable_le); | |
68 | } | |
69 | ||
70 | /** | |
71 | * crc32init_be() - allocate and initialize BE table data | |
72 | */ | |
73 | #if 0 /* not used */ | |
74 | static void crc32init_be(void) | |
75 | { | |
76 | unsigned i, j; | |
77 | uint32_t crc = 0x80000000; | |
78 | ||
79 | crc32table_be[0][0] = 0; | |
80 | ||
81 | for (i = 1; i < BE_TABLE_SIZE; i <<= 1) { | |
82 | crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0); | |
83 | for (j = 0; j < i; j++) | |
84 | crc32table_be[0][i + j] = crc ^ crc32table_be[0][j]; | |
85 | } | |
86 | for (i = 0; i < BE_TABLE_SIZE; i++) { | |
87 | crc = crc32table_be[0][i]; | |
88 | for (j = 1; j < BE_TABLE_ROWS; j++) { | |
89 | crc = crc32table_be[0][(crc >> 24) & 0xff] ^ (crc << 8); | |
90 | crc32table_be[j][i] = crc; | |
91 | } | |
92 | } | |
93 | } | |
94 | #endif | |
95 | ||
96 | static void output_table(uint32_t (*table)[256], int rows, int len, char *trans) | |
97 | { | |
98 | int i, j; | |
99 | ||
100 | for (j = 0 ; j < rows; j++) { | |
101 | printf("{"); | |
102 | for (i = 0; i < len - 1; i++) { | |
103 | if (i % ENTRIES_PER_LINE == 0) | |
104 | printf("\n"); | |
105 | printf("%s(0x%8.8xL), ", trans, table[j][i]); | |
106 | } | |
107 | printf("%s(0x%8.8xL)},\n", trans, table[j][len - 1]); | |
108 | } | |
109 | } | |
110 | ||
111 | int main(int argc, char** argv) | |
112 | { | |
113 | printf("/* this file is generated - do not edit */\n\n"); | |
114 | ||
115 | if (CRC_LE_BITS > 1) { | |
116 | crc32init_le(); | |
117 | printf("static u32 crc32table_le[%d][%d] = {", | |
118 | LE_TABLE_ROWS, LE_TABLE_SIZE); | |
119 | output_table(crc32table_le, LE_TABLE_ROWS, | |
120 | LE_TABLE_SIZE, "tole"); | |
121 | printf("};\n"); | |
122 | } | |
123 | ||
124 | #if 0 /* not used by xfsprogs */ | |
125 | if (CRC_BE_BITS > 1) { | |
126 | crc32init_be(); | |
127 | printf("static u32 crc32table_be[%d][%d] = {", | |
128 | BE_TABLE_ROWS, BE_TABLE_SIZE); | |
129 | output_table(crc32table_be, LE_TABLE_ROWS, | |
130 | BE_TABLE_SIZE, "tobe"); | |
131 | printf("};\n"); | |
132 | } | |
133 | #endif | |
134 | if (CRC_LE_BITS > 1) { | |
135 | crc32cinit_le(); | |
136 | printf("static u32 crc32ctable_le[%d][%d] = {", | |
137 | LE_TABLE_ROWS, LE_TABLE_SIZE); | |
138 | output_table(crc32ctable_le, LE_TABLE_ROWS, | |
139 | LE_TABLE_SIZE, "tole"); | |
140 | printf("};\n"); | |
141 | } | |
142 | ||
143 | return 0; | |
144 | } |