forked from mirrors/linux
5e3c1c48fa
Now that we've standardized on the byte-by-byte implementation of CRC32 as the only generic implementation (see previous commit for the rationale), remove the code for the other implementations. Tested with crc_kunit. Link: https://lore.kernel.org/r/20250123212904.118683-3-ebiggers@kernel.org Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
89 lines
2 KiB
C
89 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <stdio.h>
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#include "../include/linux/crc32poly.h"
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#include "../include/generated/autoconf.h"
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#include <inttypes.h>
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static uint32_t crc32table_le[256];
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static uint32_t crc32table_be[256];
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static uint32_t crc32ctable_le[256];
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/**
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* crc32init_le() - allocate and initialize LE table data
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*
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* crc is the crc of the byte i; other entries are filled in based on the
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* fact that crctable[i^j] = crctable[i] ^ crctable[j].
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*
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*/
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static void crc32init_le_generic(const uint32_t polynomial, uint32_t tab[256])
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{
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unsigned i, j;
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uint32_t crc = 1;
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tab[0] = 0;
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for (i = 128; i; i >>= 1) {
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crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0);
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for (j = 0; j < 256; j += 2 * i)
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tab[i + j] = crc ^ tab[j];
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}
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}
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static void crc32init_le(void)
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{
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crc32init_le_generic(CRC32_POLY_LE, crc32table_le);
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}
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static void crc32cinit_le(void)
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{
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crc32init_le_generic(CRC32C_POLY_LE, crc32ctable_le);
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}
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/**
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* crc32init_be() - allocate and initialize BE table data
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*/
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static void crc32init_be(void)
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{
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unsigned i, j;
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uint32_t crc = 0x80000000;
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crc32table_be[0] = 0;
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for (i = 1; i < 256; i <<= 1) {
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crc = (crc << 1) ^ ((crc & 0x80000000) ? CRC32_POLY_BE : 0);
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for (j = 0; j < i; j++)
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crc32table_be[i + j] = crc ^ crc32table_be[j];
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}
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}
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static void output_table(const uint32_t table[256])
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{
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int i;
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for (i = 0; i < 256; i += 4) {
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printf("\t0x%08x, 0x%08x, 0x%08x, 0x%08x,\n",
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table[i], table[i + 1], table[i + 2], table[i + 3]);
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}
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}
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int main(int argc, char** argv)
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{
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printf("/* this file is generated - do not edit */\n\n");
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crc32init_le();
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printf("static const u32 ____cacheline_aligned crc32table_le[256] = {\n");
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output_table(crc32table_le);
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printf("};\n");
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crc32init_be();
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printf("static const u32 ____cacheline_aligned crc32table_be[256] = {\n");
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output_table(crc32table_be);
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printf("};\n");
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crc32cinit_le();
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printf("static const u32 ____cacheline_aligned crc32ctable_le[256] = {\n");
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output_table(crc32ctable_le);
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printf("};\n");
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return 0;
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}
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