Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/drivers/md/mktables.c b/drivers/md/mktables.c
new file mode 100644
index 0000000..adef299
--- /dev/null
+++ b/drivers/md/mktables.c
@@ -0,0 +1,125 @@
+#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;
+}