126 lines
2.8 KiB
C
126 lines
2.8 KiB
C
#ident "$Id: mktables.c,v 1.2 2002/12/12 22:41:27 hpa Exp $"
|
|
/* ----------------------------------------------------------------------- *
|
|
*
|
|
* Copyright 2002 H. Peter Anvin - All Rights Reserved
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, Inc., 53 Temple Place Ste 330,
|
|
* Bostom MA 02111-1307, USA; either version 2 of the License, 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 \"raid6.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, ", gfmul(i,j+k));
|
|
}
|
|
printf("\n");
|
|
}
|
|
printf("\t},\n");
|
|
}
|
|
printf("};\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, ", v);
|
|
v = gfmul(v,2);
|
|
if ( v == 1 ) v = 0; /* For entry 255, not a real entry */
|
|
}
|
|
printf("\n");
|
|
}
|
|
printf("};\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, ", v);
|
|
}
|
|
printf("\n");
|
|
}
|
|
printf("};\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, ", invtbl[exptbl[i+j]^1]);
|
|
}
|
|
printf("\n");
|
|
}
|
|
printf("};\n\n");
|
|
|
|
return 0;
|
|
}
|