133 lines
2.9 KiB
C
133 lines
2.9 KiB
C
/* -*- linux-c -*- ------------------------------------------------------- *
|
|
*
|
|
* Copyright 2002-2007 H. Peter Anvin - All Rights Reserved
|
|
*
|
|
* This file is part of the Linux kernel, and is made available under
|
|
* the terms of the GNU General Public License version 2 or (at your
|
|
* option) any later version; incorporated herein by reference.
|
|
*
|
|
* ----------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* mktables.c
|
|
*
|
|
* Make RAID-6 tables. This is a host user space program to be run at
|
|
* compile time.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <inttypes.h>
|
|
#include <stdlib.h>
|
|
#include <time.h>
|
|
|
|
static uint8_t gfmul(uint8_t a, uint8_t b)
|
|
{
|
|
uint8_t v = 0;
|
|
|
|
while (b) {
|
|
if (b & 1)
|
|
v ^= a;
|
|
a = (a << 1) ^ (a & 0x80 ? 0x1d : 0);
|
|
b >>= 1;
|
|
}
|
|
|
|
return v;
|
|
}
|
|
|
|
static uint8_t gfpow(uint8_t a, int b)
|
|
{
|
|
uint8_t v = 1;
|
|
|
|
b %= 255;
|
|
if (b < 0)
|
|
b += 255;
|
|
|
|
while (b) {
|
|
if (b & 1)
|
|
v = gfmul(v, a);
|
|
a = gfmul(a, a);
|
|
b >>= 1;
|
|
}
|
|
|
|
return v;
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
int i, j, k;
|
|
uint8_t v;
|
|
uint8_t exptbl[256], invtbl[256];
|
|
|
|
printf("#include <linux/raid/pq.h>\n");
|
|
|
|
/* Compute multiplication table */
|
|
printf("\nconst u8 __attribute__((aligned(256)))\n"
|
|
"raid6_gfmul[256][256] =\n"
|
|
"{\n");
|
|
for (i = 0; i < 256; i++) {
|
|
printf("\t{\n");
|
|
for (j = 0; j < 256; j += 8) {
|
|
printf("\t\t");
|
|
for (k = 0; k < 8; k++)
|
|
printf("0x%02x,%c", gfmul(i, j + k),
|
|
(k == 7) ? '\n' : ' ');
|
|
}
|
|
printf("\t},\n");
|
|
}
|
|
printf("};\n");
|
|
printf("#ifdef __KERNEL__\n");
|
|
printf("EXPORT_SYMBOL(raid6_gfmul);\n");
|
|
printf("#endif\n");
|
|
|
|
/* Compute power-of-2 table (exponent) */
|
|
v = 1;
|
|
printf("\nconst u8 __attribute__((aligned(256)))\n"
|
|
"raid6_gfexp[256] =\n" "{\n");
|
|
for (i = 0; i < 256; i += 8) {
|
|
printf("\t");
|
|
for (j = 0; j < 8; j++) {
|
|
exptbl[i + j] = v;
|
|
printf("0x%02x,%c", v, (j == 7) ? '\n' : ' ');
|
|
v = gfmul(v, 2);
|
|
if (v == 1)
|
|
v = 0; /* For entry 255, not a real entry */
|
|
}
|
|
}
|
|
printf("};\n");
|
|
printf("#ifdef __KERNEL__\n");
|
|
printf("EXPORT_SYMBOL(raid6_gfexp);\n");
|
|
printf("#endif\n");
|
|
|
|
/* Compute inverse table x^-1 == x^254 */
|
|
printf("\nconst u8 __attribute__((aligned(256)))\n"
|
|
"raid6_gfinv[256] =\n" "{\n");
|
|
for (i = 0; i < 256; i += 8) {
|
|
printf("\t");
|
|
for (j = 0; j < 8; j++) {
|
|
invtbl[i + j] = v = gfpow(i + j, 254);
|
|
printf("0x%02x,%c", v, (j == 7) ? '\n' : ' ');
|
|
}
|
|
}
|
|
printf("};\n");
|
|
printf("#ifdef __KERNEL__\n");
|
|
printf("EXPORT_SYMBOL(raid6_gfinv);\n");
|
|
printf("#endif\n");
|
|
|
|
/* Compute inv(2^x + 1) (exponent-xor-inverse) table */
|
|
printf("\nconst u8 __attribute__((aligned(256)))\n"
|
|
"raid6_gfexi[256] =\n" "{\n");
|
|
for (i = 0; i < 256; i += 8) {
|
|
printf("\t");
|
|
for (j = 0; j < 8; j++)
|
|
printf("0x%02x,%c", invtbl[exptbl[i + j] ^ 1],
|
|
(j == 7) ? '\n' : ' ');
|
|
}
|
|
printf("};\n");
|
|
printf("#ifdef __KERNEL__\n");
|
|
printf("EXPORT_SYMBOL(raid6_gfexi);\n");
|
|
printf("#endif\n");
|
|
|
|
return 0;
|
|
}
|