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
26static uint32_t crc32table_le[LE_TABLE_ROWS][256];
27static uint32_t crc32table_be[BE_TABLE_ROWS][256];
28static 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 */
37static 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
59static void crc32init_le(void)
60{
61	crc32init_le_generic(CRC32_POLY_LE, crc32table_le);
62}
63
64static 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 */
72static 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
93static 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
108int 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