1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdio.h>
3 #include "../include/linux/crc32poly.h"
4 #include "../include/generated/autoconf.h"
5 #include "crc32defs.h"
6 #include <inttypes.h>
7
8 #define ENTRIES_PER_LINE 4
9
10 #if CRC_LE_BITS > 8
11 # define LE_TABLE_ROWS (CRC_LE_BITS/8)
12 # define LE_TABLE_SIZE 256
13 #else
14 # define LE_TABLE_ROWS 1
15 # define LE_TABLE_SIZE (1 << CRC_LE_BITS)
16 #endif
17
18 #if CRC_BE_BITS > 8
19 # define BE_TABLE_ROWS (CRC_BE_BITS/8)
20 # define BE_TABLE_SIZE 256
21 #else
22 # define BE_TABLE_ROWS 1
23 # define BE_TABLE_SIZE (1 << CRC_BE_BITS)
24 #endif
25
26 static uint32_t crc32table_le[LE_TABLE_ROWS][256];
27 static uint32_t crc32table_be[BE_TABLE_ROWS][256];
28 static uint32_t crc32ctable_le[LE_TABLE_ROWS][256];
29
30 /**
31 * crc32init_le() - allocate and initialize LE table data
32 *
33 * crc is the crc of the byte i; other entries are filled in based on the
34 * fact that crctable[i^j] = crctable[i] ^ crctable[j].
35 *
36 */
37 static void crc32init_le_generic(const uint32_t polynomial,
38 uint32_t (*tab)[256])
39 {
40 unsigned i, j;
41 uint32_t crc = 1;
42
43 tab[0][0] = 0;
44
45 for (i = LE_TABLE_SIZE >> 1; i; i >>= 1) {
46 crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0);
47 for (j = 0; j < LE_TABLE_SIZE; j += 2 * i)
48 tab[0][i + j] = crc ^ tab[0][j];
49 }
50 for (i = 0; i < LE_TABLE_SIZE; i++) {
51 crc = tab[0][i];
52 for (j = 1; j < LE_TABLE_ROWS; j++) {
53 crc = tab[0][crc & 0xff] ^ (crc >> 8);
54 tab[j][i] = crc;
55 }
56 }
57 }
58
59 static void crc32init_le(void)
60 {
61 crc32init_le_generic(CRC32_POLY_LE, crc32table_le);
62 }
63
64 static void crc32cinit_le(void)
65 {
66 crc32init_le_generic(CRC32C_POLY_LE, crc32ctable_le);
67 }
68
69 /**
70 * crc32init_be() - allocate and initialize BE table data
71 */
72 static void crc32init_be(void)
73 {
74 unsigned i, j;
75 uint32_t crc = 0x80000000;
76
77 crc32table_be[0][0] = 0;
78
79 for (i = 1; i < BE_TABLE_SIZE; i <<= 1) {
80 crc = (crc << 1) ^ ((crc & 0x80000000) ? CRC32_POLY_BE : 0);
81 for (j = 0; j < i; j++)
82 crc32table_be[0][i + j] = crc ^ crc32table_be[0][j];
83 }
84 for (i = 0; i < BE_TABLE_SIZE; i++) {
85 crc = crc32table_be[0][i];
86 for (j = 1; j < BE_TABLE_ROWS; j++) {
87 crc = crc32table_be[0][(crc >> 24) & 0xff] ^ (crc << 8);
88 crc32table_be[j][i] = crc;
89 }
90 }
91 }
92
93 static void output_table(uint32_t (*table)[256], int rows, int len, char *trans)
94 {
95 int i, j;
96
97 for (j = 0 ; j < rows; j++) {
98 printf("{");
99 for (i = 0; i < len - 1; i++) {
100 if (i % ENTRIES_PER_LINE == 0)
101 printf("\n");
102 printf("%s(0x%8.8xL), ", trans, table[j][i]);
103 }
104 printf("%s(0x%8.8xL)},\n", trans, table[j][len - 1]);
105 }
106 }
107
108 int main(int argc, char** argv)
109 {
110 printf("/* this file is generated - do not edit */\n\n");
111
112 if (CRC_LE_BITS > 1) {
113 crc32init_le();
114 printf("static const u32 ____cacheline_aligned "
115 "crc32table_le[%d][%d] = {",
116 LE_TABLE_ROWS, LE_TABLE_SIZE);
117 output_table(crc32table_le, LE_TABLE_ROWS,
118 LE_TABLE_SIZE, "tole");
119 printf("};\n");
120 }
121
122 if (CRC_BE_BITS > 1) {
123 crc32init_be();
124 printf("static const u32 ____cacheline_aligned "
125 "crc32table_be[%d][%d] = {",
126 BE_TABLE_ROWS, BE_TABLE_SIZE);
127 output_table(crc32table_be, LE_TABLE_ROWS,
128 BE_TABLE_SIZE, "tobe");
129 printf("};\n");
130 }
131 if (CRC_LE_BITS > 1) {
132 crc32cinit_le();
133 printf("static const u32 ____cacheline_aligned "
134 "crc32ctable_le[%d][%d] = {",
135 LE_TABLE_ROWS, LE_TABLE_SIZE);
136 output_table(crc32ctable_le, LE_TABLE_ROWS,
137 LE_TABLE_SIZE, "tole");
138 printf("};\n");
139 }
140
141 return 0;
142 }
143
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