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author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-12 14:08:35 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-12 14:08:35 +0300 |
commit | 4a12f38e23d10a5dbad6cce0abaadd10e5a1aa68 (patch) | |
tree | 533208f5479c17b9a7c162a425a967c7a7edf46b /lib/crc/gen_crc64table.c | |
parent | 0d2f2f4f27694a2214701e7482ab7599ce4e5e77 (diff) | |
parent | 449d48b1b99fdaa076166e200132705ac2bee711 (diff) | |
download | linux-rolling-stable.tar.xz |
Merge v6.17.2linux-rolling-stable
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib/crc/gen_crc64table.c')
-rw-r--r-- | lib/crc/gen_crc64table.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/lib/crc/gen_crc64table.c b/lib/crc/gen_crc64table.c new file mode 100644 index 000000000000..f2be9f62bab7 --- /dev/null +++ b/lib/crc/gen_crc64table.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This host program runs at kernel build time and generates the lookup tables + * used by the generic CRC64 code. + * + * Copyright 2018 SUSE Linux. + * Author: Coly Li <colyli@suse.de> + */ +#include <inttypes.h> +#include <stdio.h> + +#define CRC64_ECMA182_POLY 0x42F0E1EBA9EA3693ULL +#define CRC64_NVME_POLY 0x9A6C9329AC4BC9B5ULL + +static uint64_t crc64_table[256] = {0}; +static uint64_t crc64_nvme_table[256] = {0}; + +static void generate_reflected_crc64_table(uint64_t table[256], uint64_t poly) +{ + uint64_t i, j, c, crc; + + for (i = 0; i < 256; i++) { + crc = 0ULL; + c = i; + + for (j = 0; j < 8; j++) { + if ((crc ^ (c >> j)) & 1) + crc = (crc >> 1) ^ poly; + else + crc >>= 1; + } + table[i] = crc; + } +} + +static void generate_crc64_table(uint64_t table[256], uint64_t poly) +{ + uint64_t i, j, c, crc; + + for (i = 0; i < 256; i++) { + crc = 0; + c = i << 56; + + for (j = 0; j < 8; j++) { + if ((crc ^ c) & 0x8000000000000000ULL) + crc = (crc << 1) ^ poly; + else + crc <<= 1; + c <<= 1; + } + + table[i] = crc; + } +} + +static void output_table(uint64_t table[256]) +{ + int i; + + for (i = 0; i < 256; i++) { + printf("\t0x%016" PRIx64 "ULL", table[i]); + if (i & 0x1) + printf(",\n"); + else + printf(", "); + } + printf("};\n"); +} + +static void print_crc64_tables(void) +{ + printf("/* this file is generated - do not edit */\n\n"); + printf("#include <linux/types.h>\n"); + printf("#include <linux/cache.h>\n\n"); + printf("static const u64 ____cacheline_aligned crc64table[256] = {\n"); + output_table(crc64_table); + + printf("\nstatic const u64 ____cacheline_aligned crc64nvmetable[256] = {\n"); + output_table(crc64_nvme_table); +} + +int main(int argc, char *argv[]) +{ + generate_crc64_table(crc64_table, CRC64_ECMA182_POLY); + generate_reflected_crc64_table(crc64_nvme_table, CRC64_NVME_POLY); + print_crc64_tables(); + return 0; +} |