/* -*- 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 #include #include #include #include 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 \n"); printf("#include \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 vector multiplication table */ printf("\nconst u8 __attribute__((aligned(256)))\n" "raid6_vgfmul[256][32] =\n" "{\n"); for (i = 0; i < 256; i++) { printf("\t{\n"); for (j = 0; j < 16; j += 8) { printf("\t\t"); for (k = 0; k < 8; k++) printf("0x%02x,%c", gfmul(i, j + k), (k == 7) ? '\n' : ' '); } for (j = 0; j < 16; j += 8) { printf("\t\t"); for (k = 0; k < 8; k++) printf("0x%02x,%c", gfmul(i, (j + k) << 4), (k == 7) ? '\n' : ' '); } printf("\t},\n"); } printf("};\n"); printf("#ifdef __KERNEL__\n"); printf("EXPORT_SYMBOL(raid6_vgfmul);\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; } howmsg=1'>Expand)AuthorFilesLines