Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | #ident "$Id: mktables.c,v 1.2 2002/12/12 22:41:27 hpa Exp $" |
2 | /* ----------------------------------------------------------------------- * | |
3 | * | |
4 | * Copyright 2002 H. Peter Anvin - All Rights Reserved | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation, Inc., 53 Temple Place Ste 330, | |
9 | * Bostom MA 02111-1307, USA; either version 2 of the License, or | |
10 | * (at your option) any later version; incorporated herein by reference. | |
11 | * | |
12 | * ----------------------------------------------------------------------- */ | |
13 | ||
14 | /* | |
15 | * mktables.c | |
16 | * | |
17 | * Make RAID-6 tables. This is a host user space program to be run at | |
18 | * compile time. | |
19 | */ | |
20 | ||
21 | #include <stdio.h> | |
22 | #include <string.h> | |
23 | #include <inttypes.h> | |
24 | #include <stdlib.h> | |
25 | #include <time.h> | |
26 | ||
27 | static uint8_t gfmul(uint8_t a, uint8_t b) | |
28 | { | |
29 | uint8_t v = 0; | |
30 | ||
31 | while ( b ) { | |
32 | if ( b & 1 ) v ^= a; | |
33 | a = (a << 1) ^ (a & 0x80 ? 0x1d : 0); | |
34 | b >>= 1; | |
35 | } | |
36 | return v; | |
37 | } | |
38 | ||
39 | static uint8_t gfpow(uint8_t a, int b) | |
40 | { | |
41 | uint8_t v = 1; | |
42 | ||
43 | b %= 255; | |
44 | if ( b < 0 ) | |
45 | b += 255; | |
46 | ||
47 | while ( b ) { | |
48 | if ( b & 1 ) v = gfmul(v,a); | |
49 | a = gfmul(a,a); | |
50 | b >>= 1; | |
51 | } | |
52 | return v; | |
53 | } | |
54 | ||
55 | int main(int argc, char *argv[]) | |
56 | { | |
57 | int i, j, k; | |
58 | uint8_t v; | |
59 | uint8_t exptbl[256], invtbl[256]; | |
60 | ||
61 | printf("#include \"raid6.h\"\n"); | |
62 | ||
63 | /* Compute multiplication table */ | |
64 | printf("\nconst u8 __attribute__((aligned(256)))\n" | |
65 | "raid6_gfmul[256][256] =\n" | |
66 | "{\n"); | |
67 | for ( i = 0 ; i < 256 ; i++ ) { | |
68 | printf("\t{\n"); | |
69 | for ( j = 0 ; j < 256 ; j += 8 ) { | |
70 | printf("\t\t"); | |
71 | for ( k = 0 ; k < 8 ; k++ ) { | |
72 | printf("0x%02x, ", gfmul(i,j+k)); | |
73 | } | |
74 | printf("\n"); | |
75 | } | |
76 | printf("\t},\n"); | |
77 | } | |
78 | printf("};\n"); | |
79 | ||
80 | /* Compute power-of-2 table (exponent) */ | |
81 | v = 1; | |
82 | printf("\nconst u8 __attribute__((aligned(256)))\n" | |
83 | "raid6_gfexp[256] =\n" | |
84 | "{\n"); | |
85 | for ( i = 0 ; i < 256 ; i += 8 ) { | |
86 | printf("\t"); | |
87 | for ( j = 0 ; j < 8 ; j++ ) { | |
88 | exptbl[i+j] = v; | |
89 | printf("0x%02x, ", v); | |
90 | v = gfmul(v,2); | |
91 | if ( v == 1 ) v = 0; /* For entry 255, not a real entry */ | |
92 | } | |
93 | printf("\n"); | |
94 | } | |
95 | printf("};\n"); | |
96 | ||
97 | /* Compute inverse table x^-1 == x^254 */ | |
98 | printf("\nconst u8 __attribute__((aligned(256)))\n" | |
99 | "raid6_gfinv[256] =\n" | |
100 | "{\n"); | |
101 | for ( i = 0 ; i < 256 ; i += 8 ) { | |
102 | printf("\t"); | |
103 | for ( j = 0 ; j < 8 ; j++ ) { | |
104 | invtbl[i+j] = v = gfpow(i+j,254); | |
105 | printf("0x%02x, ", v); | |
106 | } | |
107 | printf("\n"); | |
108 | } | |
109 | printf("};\n"); | |
110 | ||
111 | /* Compute inv(2^x + 1) (exponent-xor-inverse) table */ | |
112 | printf("\nconst u8 __attribute__((aligned(256)))\n" | |
113 | "raid6_gfexi[256] =\n" | |
114 | "{\n"); | |
115 | for ( i = 0 ; i < 256 ; i += 8 ) { | |
116 | printf("\t"); | |
117 | for ( j = 0 ; j < 8 ; j++ ) { | |
118 | printf("0x%02x, ", invtbl[exptbl[i+j]^1]); | |
119 | } | |
120 | printf("\n"); | |
121 | } | |
122 | printf("};\n\n"); | |
123 | ||
124 | return 0; | |
125 | } |