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89a5159140
Move all CRC files in lib/ into a subdirectory lib/crc/ to keep them from cluttering up the main lib/ directory. Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20250607200454.73587-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
88 lines
1.8 KiB
C
88 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* This host program runs at kernel build time and generates the lookup tables
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* used by the generic CRC64 code.
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*
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* Copyright 2018 SUSE Linux.
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* Author: Coly Li <colyli@suse.de>
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*/
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#include <inttypes.h>
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#include <stdio.h>
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#define CRC64_ECMA182_POLY 0x42F0E1EBA9EA3693ULL
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#define CRC64_NVME_POLY 0x9A6C9329AC4BC9B5ULL
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static uint64_t crc64_table[256] = {0};
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static uint64_t crc64_nvme_table[256] = {0};
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static void generate_reflected_crc64_table(uint64_t table[256], uint64_t poly)
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{
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uint64_t i, j, c, crc;
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for (i = 0; i < 256; i++) {
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crc = 0ULL;
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c = i;
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for (j = 0; j < 8; j++) {
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if ((crc ^ (c >> j)) & 1)
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crc = (crc >> 1) ^ poly;
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else
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crc >>= 1;
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}
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table[i] = crc;
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}
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}
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static void generate_crc64_table(uint64_t table[256], uint64_t poly)
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{
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uint64_t i, j, c, crc;
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for (i = 0; i < 256; i++) {
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crc = 0;
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c = i << 56;
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for (j = 0; j < 8; j++) {
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if ((crc ^ c) & 0x8000000000000000ULL)
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crc = (crc << 1) ^ poly;
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else
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crc <<= 1;
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c <<= 1;
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}
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table[i] = crc;
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}
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}
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static void output_table(uint64_t table[256])
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{
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int i;
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for (i = 0; i < 256; i++) {
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printf("\t0x%016" PRIx64 "ULL", table[i]);
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if (i & 0x1)
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printf(",\n");
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else
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printf(", ");
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}
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printf("};\n");
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}
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static void print_crc64_tables(void)
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{
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printf("/* this file is generated - do not edit */\n\n");
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printf("#include <linux/types.h>\n");
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printf("#include <linux/cache.h>\n\n");
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printf("static const u64 ____cacheline_aligned crc64table[256] = {\n");
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output_table(crc64_table);
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printf("\nstatic const u64 ____cacheline_aligned crc64nvmetable[256] = {\n");
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output_table(crc64_nvme_table);
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}
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int main(int argc, char *argv[])
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{
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generate_crc64_table(crc64_table, CRC64_ECMA182_POLY);
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generate_reflected_crc64_table(crc64_nvme_table, CRC64_NVME_POLY);
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print_crc64_tables();
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return 0;
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}
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