mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-30 23:54:04 +08:00
cbc0a40e17
The NVM Express specification extended data integrity fields to 64 bits
using the Rocksoft parameters. Add the poly to the crc64 table
generation, and provide a generic library routine implementing the
algorithm.
The Rocksoft 64-bit CRC model parameters are as follows:
Poly: 0xAD93D23594C93659
Initial value: 0xFFFFFFFFFFFFFFFF
Reflected Input: True
Reflected Output: True
Xor Final: 0xFFFFFFFFFFFFFFFF
Since this model used reflected bits, the implementation generates the
reflected table so the result is ordered consistently.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220303201312.3255347-6-kbusch@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
96 lines
2.1 KiB
C
96 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Generate lookup table for the table-driven CRC64 calculation.
|
|
*
|
|
* gen_crc64table is executed in kernel build time and generates
|
|
* lib/crc64table.h. This header is included by lib/crc64.c for
|
|
* the table-driven CRC64 calculation.
|
|
*
|
|
* See lib/crc64.c for more information about which specification
|
|
* and polynomial arithmetic that gen_crc64table.c follows to
|
|
* generate the lookup table.
|
|
*
|
|
* Copyright 2018 SUSE Linux.
|
|
* Author: Coly Li <colyli@suse.de>
|
|
*/
|
|
#include <inttypes.h>
|
|
#include <stdio.h>
|
|
|
|
#define CRC64_ECMA182_POLY 0x42F0E1EBA9EA3693ULL
|
|
#define CRC64_ROCKSOFT_POLY 0x9A6C9329AC4BC9B5ULL
|
|
|
|
static uint64_t crc64_table[256] = {0};
|
|
static uint64_t crc64_rocksoft_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 crc64rocksofttable[256] = {\n");
|
|
output_table(crc64_rocksoft_table);
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
generate_crc64_table(crc64_table, CRC64_ECMA182_POLY);
|
|
generate_reflected_crc64_table(crc64_rocksoft_table, CRC64_ROCKSOFT_POLY);
|
|
print_crc64_tables();
|
|
return 0;
|
|
}
|