1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * This host program runs at kernel build time and generates the lookup tables 4 * used by the generic CRC64 code. 5 * 6 * Copyright 2018 SUSE Linux. 7 * Author: Coly Li <colyli@suse.de> 8 */ 9 #include <inttypes.h> 10 #include <stdio.h> 11 12 #define CRC64_ECMA182_POLY 0x42F0E1EBA9EA3693ULL 13 #define CRC64_NVME_POLY 0x9A6C9329AC4BC9B5ULL 14 15 static uint64_t crc64_table[256] = {0}; 16 static uint64_t crc64_nvme_table[256] = {0}; 17 18 static void generate_reflected_crc64_table(uint64_t table[256], uint64_t poly) 19 { 20 uint64_t i, j, c, crc; 21 22 for (i = 0; i < 256; i++) { 23 crc = 0ULL; 24 c = i; 25 26 for (j = 0; j < 8; j++) { 27 if ((crc ^ (c >> j)) & 1) 28 crc = (crc >> 1) ^ poly; 29 else 30 crc >>= 1; 31 } 32 table[i] = crc; 33 } 34 } 35 36 static void generate_crc64_table(uint64_t table[256], uint64_t poly) 37 { 38 uint64_t i, j, c, crc; 39 40 for (i = 0; i < 256; i++) { 41 crc = 0; 42 c = i << 56; 43 44 for (j = 0; j < 8; j++) { 45 if ((crc ^ c) & 0x8000000000000000ULL) 46 crc = (crc << 1) ^ poly; 47 else 48 crc <<= 1; 49 c <<= 1; 50 } 51 52 table[i] = crc; 53 } 54 } 55 56 static void output_table(uint64_t table[256]) 57 { 58 int i; 59 60 for (i = 0; i < 256; i++) { 61 printf("\t0x%016" PRIx64 "ULL", table[i]); 62 if (i & 0x1) 63 printf(",\n"); 64 else 65 printf(", "); 66 } 67 printf("};\n"); 68 } 69 70 static void print_crc64_tables(void) 71 { 72 printf("/* this file is generated - do not edit */\n\n"); 73 printf("#include <linux/types.h>\n"); 74 printf("#include <linux/cache.h>\n\n"); 75 printf("static const u64 ____cacheline_aligned crc64table[256] = {\n"); 76 output_table(crc64_table); 77 78 printf("\nstatic const u64 ____cacheline_aligned crc64nvmetable[256] = {\n"); 79 output_table(crc64_nvme_table); 80 } 81 82 int main(int argc, char *argv[]) 83 { 84 generate_crc64_table(crc64_table, CRC64_ECMA182_POLY); 85 generate_reflected_crc64_table(crc64_nvme_table, CRC64_NVME_POLY); 86 print_crc64_tables(); 87 return 0; 88 } 89