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snapraid/raid.c
Andrea Mazzoleni 73a860bec0 Adds prelinary RAID5 unrolled by 8.
2013-06-20 23:59:33 +02:00

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/*
* Copyright (C) 2011 Andrea Mazzoleni
*
* 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, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* -*- linux-c -*- ------------------------------------------------------- *
*
* Copyright 2002-2004 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,
* Boston MA 02111-1307, USA; either version 2 of the License, or
* (at your option) any later version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
#include "portable.h"
#include "raid.h"
#include "cpu.h"
#include "tables.h"
/* internal forwarder */
static void (*raid5_gen)(unsigned char** buffer, unsigned diskmax, unsigned size);
static void (*raid6_gen)(unsigned char** buffer, unsigned diskmax, unsigned size);
/*
* 2-way unrolled portable integer math RAID-5 instruction set
*/
void raid5_int32r2(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
int z, z0;
unsigned d;
uint32_t wp0;
uint32_t wp1;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
for(d=0;d<size;d+=8) {
wp0 = *(uint32_t *)&buffer[z0][d+0*4];
wp1 = *(uint32_t *)&buffer[z0][d+1*4];
for(z=z0-1;z>=0;--z) {
wp0 ^= *(uint32_t *)&buffer[z][d+0*4];
wp1 ^= *(uint32_t *)&buffer[z][d+1*4];
}
*(uint32_t *)&p[d+4*0] = wp0;
*(uint32_t *)&p[d+4*1] = wp1;
}
}
#if defined(__i386__) || defined(__x86_64__)
/*
* Unrolled-by-2 MMX implementation
*/
void raid5_mmxr2(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
int z, z0;
unsigned d;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
for(d=0;d<size;d+=16) {
asm volatile("movq %0,%%mm0" : : "m" (buffer[z0][d]));
asm volatile("movq %0,%%mm1" : : "m" (buffer[z0][d+8]));
for(z=z0-1;z>=0;--z) {
asm volatile("movq %0,%%mm4" : : "m" (buffer[z][d]));
asm volatile("movq %0,%%mm5" : : "m" (buffer[z][d+8]));
asm volatile("pxor %mm4,%mm0");
asm volatile("pxor %mm5,%mm1");
}
asm volatile("movq %%mm0,%0" : "=m" (p[d]));
asm volatile("movq %%mm1,%0" : "=m" (p[d+8]));
}
asm volatile("emms" : : : "memory");
}
/*
* Unrolled-by-4 MMX implementation
*/
void raid5_mmxr4(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
int z, z0;
unsigned d;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
for(d=0;d<size;d+=32) {
asm volatile("movq %0,%%mm0" : : "m" (buffer[z0][d]));
asm volatile("movq %0,%%mm1" : : "m" (buffer[z0][d+8]));
asm volatile("movq %0,%%mm2" : : "m" (buffer[z0][d+16]));
asm volatile("movq %0,%%mm3" : : "m" (buffer[z0][d+24]));
for(z=z0-1;z>=0;--z) {
asm volatile("movq %0,%%mm4" : : "m" (buffer[z][d]));
asm volatile("movq %0,%%mm5" : : "m" (buffer[z][d+8]));
asm volatile("movq %0,%%mm6" : : "m" (buffer[z][d+16]));
asm volatile("movq %0,%%mm7" : : "m" (buffer[z][d+24]));
asm volatile("pxor %mm4,%mm0");
asm volatile("pxor %mm5,%mm1");
asm volatile("pxor %mm6,%mm2");
asm volatile("pxor %mm7,%mm3");
}
asm volatile("movq %%mm0,%0" : "=m" (p[d]));
asm volatile("movq %%mm1,%0" : "=m" (p[d+8]));
asm volatile("movq %%mm2,%0" : "=m" (p[d+16]));
asm volatile("movq %%mm3,%0" : "=m" (p[d+24]));
}
asm volatile("emms" : : : "memory");
}
/*
* Unrolled-by-2 SSE2 implementation
*/
void raid5_sse2r2(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
int z, z0;
unsigned d;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
for(d=0;d<size;d+=32) {
asm volatile("movdqa %0,%%xmm0" : : "m" (buffer[z0][d]));
asm volatile("movdqa %0,%%xmm1" : : "m" (buffer[z0][d+16]));
for(z=z0-1;z>=0;--z) {
asm volatile("movdqa %0,%%xmm4" : : "m" (buffer[z][d]));
asm volatile("movdqa %0,%%xmm5" : : "m" (buffer[z][d+16]));
asm volatile("pxor %xmm4,%xmm0");
asm volatile("pxor %xmm5,%xmm1");
}
asm volatile("movntdq %%xmm0,%0" : "=m" (p[d]));
asm volatile("movntdq %%xmm1,%0" : "=m" (p[d+16]));
}
asm volatile("sfence" : : : "memory");
}
/*
* Unrolled-by-4 SSE2 implementation
*/
void raid5_sse2r4(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
int z, z0;
unsigned d;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
for(d=0;d<size;d+=64) {
asm volatile("movdqa %0,%%xmm0" : : "m" (buffer[z0][d]));
asm volatile("movdqa %0,%%xmm1" : : "m" (buffer[z0][d+16]));
asm volatile("movdqa %0,%%xmm2" : : "m" (buffer[z0][d+32]));
asm volatile("movdqa %0,%%xmm3" : : "m" (buffer[z0][d+48]));
for(z=z0-1;z>=0;--z) {
asm volatile("movdqa %0,%%xmm4" : : "m" (buffer[z][d]));
asm volatile("movdqa %0,%%xmm5" : : "m" (buffer[z][d+16]));
asm volatile("movdqa %0,%%xmm6" : : "m" (buffer[z][d+32]));
asm volatile("movdqa %0,%%xmm7" : : "m" (buffer[z][d+48]));
asm volatile("pxor %xmm4,%xmm0");
asm volatile("pxor %xmm5,%xmm1");
asm volatile("pxor %xmm6,%xmm2");
asm volatile("pxor %xmm7,%xmm3");
}
asm volatile("movntdq %%xmm0,%0" : "=m" (p[d]));
asm volatile("movntdq %%xmm1,%0" : "=m" (p[d+16]));
asm volatile("movntdq %%xmm2,%0" : "=m" (p[d+32]));
asm volatile("movntdq %%xmm3,%0" : "=m" (p[d+48]));
}
asm volatile("sfence" : : : "memory");
}
#endif
#if defined(__x86_64__)
/*
* Unrolled-by-8 SSE2 implementation
* Note that it uses all the 16 registers, meaning that x64 is required.
*/
void raid5_sse2r8(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
int z, z0;
unsigned d;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
for(d=0;d<size;d+=128) {
asm volatile("movdqa %0,%%xmm0" : : "m" (buffer[z0][d]));
asm volatile("movdqa %0,%%xmm1" : : "m" (buffer[z0][d+16]));
asm volatile("movdqa %0,%%xmm2" : : "m" (buffer[z0][d+32]));
asm volatile("movdqa %0,%%xmm3" : : "m" (buffer[z0][d+48]));
asm volatile("movdqa %0,%%xmm4" : : "m" (buffer[z0][d+64]));
asm volatile("movdqa %0,%%xmm5" : : "m" (buffer[z0][d+80]));
asm volatile("movdqa %0,%%xmm6" : : "m" (buffer[z0][d+96]));
asm volatile("movdqa %0,%%xmm7" : : "m" (buffer[z0][d+112]));
for(z=z0-1;z>=0;--z) {
asm volatile("movdqa %0,%%xmm8" : : "m" (buffer[z][d]));
asm volatile("movdqa %0,%%xmm9" : : "m" (buffer[z][d+16]));
asm volatile("movdqa %0,%%xmm10" : : "m" (buffer[z][d+32]));
asm volatile("movdqa %0,%%xmm11" : : "m" (buffer[z][d+48]));
asm volatile("movdqa %0,%%xmm12" : : "m" (buffer[z][d+64]));
asm volatile("movdqa %0,%%xmm13" : : "m" (buffer[z][d+80]));
asm volatile("movdqa %0,%%xmm14" : : "m" (buffer[z][d+96]));
asm volatile("movdqa %0,%%xmm15" : : "m" (buffer[z][d+112]));
asm volatile("pxor %xmm8,%xmm0");
asm volatile("pxor %xmm9,%xmm1");
asm volatile("pxor %xmm10,%xmm2");
asm volatile("pxor %xmm11,%xmm3");
asm volatile("pxor %xmm12,%xmm4");
asm volatile("pxor %xmm13,%xmm5");
asm volatile("pxor %xmm14,%xmm6");
asm volatile("pxor %xmm15,%xmm7");
}
asm volatile("movntdq %%xmm0,%0" : "=m" (p[d]));
asm volatile("movntdq %%xmm1,%0" : "=m" (p[d+16]));
asm volatile("movntdq %%xmm2,%0" : "=m" (p[d+32]));
asm volatile("movntdq %%xmm3,%0" : "=m" (p[d+48]));
asm volatile("movntdq %%xmm4,%0" : "=m" (p[d+64]));
asm volatile("movntdq %%xmm5,%0" : "=m" (p[d+80]));
asm volatile("movntdq %%xmm6,%0" : "=m" (p[d+96]));
asm volatile("movntdq %%xmm7,%0" : "=m" (p[d+112]));
}
asm volatile("sfence" : : : "memory");
}
#endif
/*
* Repeats an 8 bit nibble to a full 32 bits value.
*/
#define NBYTES(x) ((x) * 0x01010101U)
/*
* These sub-operations are separate inlines since they can sometimes be
* specially optimized using architecture-specific hacks.
*/
/*
* The SHLBYTE() operation shifts each byte left by 1, *not*
* rolling over into the next byte.
*/
static inline uint32_t SHLBYTE(uint32_t v)
{
uint32_t vv;
vv = (v << 1) & NBYTES(0xfe);
return vv;
}
/*
* The MASK() operation returns 0xFF in any byte for which the high
* bit is 1, 0x00 for any byte for which the high bit is 0.
*/
static inline uint32_t MASK(uint32_t v)
{
uint32_t vv;
vv = v & NBYTES(0x80);
vv = (vv << 1) - (vv >> 7); /* Overflow on the top bit is OK */
return vv;
}
/*
* 2-way unrolled portable integer math RAID-6 instruction set
*/
void raid6_int32r2(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
unsigned char* q;
int z, z0;
unsigned d;
uint32_t wd0, wq0, wp0, w10, w20;
uint32_t wd1, wq1, wp1, w11, w21;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
q = buffer[z0+2]; /* RS qarity */
for(d=0;d<size;d+=8) {
wq0 = wp0 = *(uint32_t *)&buffer[z0][d+0*4];
wq1 = wp1 = *(uint32_t *)&buffer[z0][d+1*4];
for (z=z0-1;z>= 0;--z) {
wd0 = *(uint32_t *)&buffer[z][d+0*4];
wd1 = *(uint32_t *)&buffer[z][d+1*4];
wp0 ^= wd0;
wp1 ^= wd1;
w20 = MASK(wq0);
w21 = MASK(wq1);
w10 = SHLBYTE(wq0);
w11 = SHLBYTE(wq1);
w20 &= NBYTES(0x1d);
w21 &= NBYTES(0x1d);
w10 ^= w20;
w11 ^= w21;
wq0 = w10 ^ wd0;
wq1 = w11 ^ wd1;
}
*(uint32_t *)&p[d+4*0] = wp0;
*(uint32_t *)&p[d+4*1] = wp1;
*(uint32_t *)&q[d+4*0] = wq0;
*(uint32_t *)&q[d+4*1] = wq1;
}
}
#if defined(__i386__) || defined(__x86_64__)
static const struct raid6_mmx_constants {
uint64_t x1d;
} raid6_mmx_constants = {
0x1d1d1d1d1d1d1d1dULL,
};
/*
* Unrolled-by-2 MMX implementation
*/
void raid6_mmxr2(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
unsigned char* q;
int z, z0;
unsigned d;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
q = buffer[z0+2]; /* RS qarity */
asm volatile("movq %0,%%mm0" : : "m" (raid6_mmx_constants.x1d));
asm volatile("pxor %mm5,%mm5"); /* Zero temp */
asm volatile("pxor %mm7,%mm7"); /* Zero temp */
for(d=0;d<size;d+=16) {
asm volatile("movq %0,%%mm2" : : "m" (buffer[z0][d]));
asm volatile("movq %0,%%mm3" : : "m" (buffer[z0][d+8]));
asm volatile("movq %mm2,%mm4");
asm volatile("movq %mm3,%mm6");
for(z=z0-1;z>=0;--z) {
asm volatile("pcmpgtb %mm4,%mm5");
asm volatile("pcmpgtb %mm6,%mm7");
asm volatile("paddb %mm4,%mm4");
asm volatile("paddb %mm6,%mm6");
asm volatile("pand %mm0,%mm5");
asm volatile("pand %mm0,%mm7");
asm volatile("pxor %mm5,%mm4");
asm volatile("pxor %mm7,%mm6");
asm volatile("movq %0,%%mm5" : : "m" (buffer[z][d]));
asm volatile("movq %0,%%mm7" : : "m" (buffer[z][d+8]));
asm volatile("pxor %mm5,%mm2");
asm volatile("pxor %mm7,%mm3");
asm volatile("pxor %mm5,%mm4");
asm volatile("pxor %mm7,%mm6");
asm volatile("pxor %mm5,%mm5");
asm volatile("pxor %mm7,%mm7");
}
asm volatile("movq %%mm2,%0" : "=m" (p[d]));
asm volatile("movq %%mm3,%0" : "=m" (p[d+8]));
asm volatile("movq %%mm4,%0" : "=m" (q[d]));
asm volatile("movq %%mm6,%0" : "=m" (q[d+8]));
}
asm volatile("emms" : : : "memory");
}
static const struct raid6_sse_constants {
uint64_t x1d[2];
} raid6_sse_constants __attribute__((aligned(16))) = {
{ 0x1d1d1d1d1d1d1d1dULL, 0x1d1d1d1d1d1d1d1dULL },
};
/*
* Unrolled-by-2 SSE2 implementation
*/
void raid6_sse2r2(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
unsigned char* q;
int z, z0;
unsigned d;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
q = buffer[z0+2]; /* RS qarity */
asm volatile("movdqa %0,%%xmm7" : : "m" (raid6_sse_constants.x1d[0]));
asm volatile("pxor %xmm4,%xmm4"); /* Zero temp */
asm volatile("pxor %xmm5,%xmm5"); /* Zero temp */
for(d=0;d<size;d+=32) {
asm volatile("movdqa %0,%%xmm0" : : "m" (buffer[z0][d])); /* P[0] */
asm volatile("movdqa %0,%%xmm1" : : "m" (buffer[z0][d+16])); /* P[1] */
asm volatile("movdqa %xmm0,%xmm2"); /* Q[0] */
asm volatile("movdqa %xmm1,%xmm3"); /* Q[1] */
for(z=z0-1;z>=0;--z) {
asm volatile("pcmpgtb %xmm2,%xmm4");
asm volatile("pcmpgtb %xmm3,%xmm5");
asm volatile("paddb %xmm2,%xmm2");
asm volatile("paddb %xmm3,%xmm3");
asm volatile("pand %xmm7,%xmm4");
asm volatile("pand %xmm7,%xmm5");
asm volatile("pxor %xmm4,%xmm2");
asm volatile("pxor %xmm5,%xmm3");
asm volatile("movdqa %0,%%xmm4" : : "m" (buffer[z][d]));
asm volatile("movdqa %0,%%xmm5" : : "m" (buffer[z][d+16]));
asm volatile("pxor %xmm4,%xmm0");
asm volatile("pxor %xmm5,%xmm1");
asm volatile("pxor %xmm4,%xmm2");
asm volatile("pxor %xmm5,%xmm3");
asm volatile("pxor %xmm4,%xmm4");
asm volatile("pxor %xmm5,%xmm5");
}
asm volatile("movntdq %%xmm0,%0" : "=m" (p[d]));
asm volatile("movntdq %%xmm1,%0" : "=m" (p[d+16]));
asm volatile("movntdq %%xmm2,%0" : "=m" (q[d]));
asm volatile("movntdq %%xmm3,%0" : "=m" (q[d+16]));
}
asm volatile("sfence" : : : "memory");
}
#endif
#if defined(__x86_64__)
/*
* Unrolled-by-4 SSE2 implementation
* Note that it uses all the 16 registers, meaning that x64 is required.
*/
void raid6_sse2r4(unsigned char** buffer, unsigned diskmax, unsigned size)
{
unsigned char* p;
unsigned char* q;
int z, z0;
unsigned d;
z0 = diskmax - 1; /* Highest data disk */
p = buffer[z0+1]; /* XOR parity */
q = buffer[z0+2]; /* RS qarity */
asm volatile("movdqa %0,%%xmm15" : : "m" (raid6_sse_constants.x1d[0]));
asm volatile("pxor %xmm8,%xmm8"); /* Zero temp */
asm volatile("pxor %xmm9,%xmm9"); /* Zero temp */
asm volatile("pxor %xmm10,%xmm10"); /* Zero temp */
asm volatile("pxor %xmm11,%xmm11"); /* Zero temp */
for(d=0;d<size;d+=64) {
asm volatile("movdqa %0,%%xmm0" : : "m" (buffer[z0][d])); /* P[0] */
asm volatile("movdqa %0,%%xmm1" : : "m" (buffer[z0][d+16])); /* P[1] */
asm volatile("movdqa %0,%%xmm2" : : "m" (buffer[z0][d+32])); /* P[2] */
asm volatile("movdqa %0,%%xmm3" : : "m" (buffer[z0][d+48])); /* P[3] */
asm volatile("movdqa %xmm0,%xmm4"); /* Q[0] */
asm volatile("movdqa %xmm1,%xmm5"); /* Q[1] */
asm volatile("movdqa %xmm2,%xmm6"); /* Q[2] */
asm volatile("movdqa %xmm3,%xmm7"); /* Q[3] */
for(z=z0-1;z>=0;--z) {
asm volatile("pcmpgtb %xmm4,%xmm8");
asm volatile("pcmpgtb %xmm5,%xmm9");
asm volatile("pcmpgtb %xmm6,%xmm10");
asm volatile("pcmpgtb %xmm7,%xmm11");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("paddb %xmm5,%xmm5");
asm volatile("paddb %xmm6,%xmm6");
asm volatile("paddb %xmm7,%xmm7");
asm volatile("pand %xmm15,%xmm8");
asm volatile("pand %xmm15,%xmm9");
asm volatile("pand %xmm15,%xmm10");
asm volatile("pand %xmm15,%xmm11");
asm volatile("pxor %xmm8,%xmm4");
asm volatile("pxor %xmm9,%xmm5");
asm volatile("pxor %xmm10,%xmm6");
asm volatile("pxor %xmm11,%xmm7");
asm volatile("movdqa %0,%%xmm8" : : "m" (buffer[z][d]));
asm volatile("movdqa %0,%%xmm9" : : "m" (buffer[z][d+16]));
asm volatile("movdqa %0,%%xmm10" : : "m" (buffer[z][d+32]));
asm volatile("movdqa %0,%%xmm11" : : "m" (buffer[z][d+48]));
asm volatile("pxor %xmm8,%xmm0");
asm volatile("pxor %xmm9,%xmm1");
asm volatile("pxor %xmm10,%xmm2");
asm volatile("pxor %xmm11,%xmm3");
asm volatile("pxor %xmm8,%xmm4");
asm volatile("pxor %xmm9,%xmm5");
asm volatile("pxor %xmm10,%xmm6");
asm volatile("pxor %xmm11,%xmm7");
asm volatile("pxor %xmm8,%xmm8");
asm volatile("pxor %xmm9,%xmm9");
asm volatile("pxor %xmm10,%xmm10");
asm volatile("pxor %xmm11,%xmm11");
}
asm volatile("movntdq %%xmm0,%0" : "=m" (p[d]));
asm volatile("movntdq %%xmm1,%0" : "=m" (p[d+16]));
asm volatile("movntdq %%xmm2,%0" : "=m" (p[d+32]));
asm volatile("movntdq %%xmm3,%0" : "=m" (p[d+48]));
asm volatile("movntdq %%xmm4,%0" : "=m" (q[d]));
asm volatile("movntdq %%xmm5,%0" : "=m" (q[d+16]));
asm volatile("movntdq %%xmm6,%0" : "=m" (q[d+32]));
asm volatile("movntdq %%xmm7,%0" : "=m" (q[d+48]));
}
asm volatile("sfence" : : : "memory");
}
#endif
void raid5_recov_data(unsigned char** dptrs, unsigned diskmax, unsigned size, int faila)
{
unsigned char *p, *d;
d = dptrs[faila];
p = dptrs[diskmax];
/* Compute syndrome using parity for the missing data page. */
dptrs[faila] = p;
dptrs[diskmax] = d;
raid5_gen(dptrs, diskmax, size);
/* Restore pointer table */
dptrs[faila] = d;
dptrs[diskmax] = p;
}
void raid6_recov_2data(unsigned char** dptrs, unsigned diskmax, unsigned size, int faila, int failb, unsigned char* zero)
{
unsigned char *p, *q, *dp, *dq;
unsigned char px, qx, db;
const unsigned char *pbmul; /* P multiplier table for B data */
const unsigned char *qmul; /* Q multiplier table (for both) */
p = dptrs[diskmax];
q = dptrs[diskmax+1];
/* Compute syndrome with zero for the missing data pages. */
/* Use the dead data pages as temporary storage for delta p and delta q. */
dp = dptrs[faila];
dptrs[faila] = zero;
dptrs[diskmax] = dp;
dq = dptrs[failb];
dptrs[failb] = zero;
dptrs[diskmax+1] = dq;
raid6_gen(dptrs, diskmax, size);
/* Restore pointer table */
dptrs[faila] = dp;
dptrs[failb] = dq;
dptrs[diskmax] = p;
dptrs[diskmax+1] = q;
/* Now, pick the proper data tables */
pbmul = raid6_gfmul[raid6_gfexi[failb-faila]];
qmul = raid6_gfmul[raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]];
/* Now do it... */
while (size--) {
px = *p ^ *dp;
qx = qmul[*q ^ *dq];
*dq++ = db = pbmul[px] ^ qx; /* Reconstructed B */
*dp++ = db ^ px; /* Reconstructed A */
p++;
q++;
}
}
void raid6_recov_datap(unsigned char** dptrs, unsigned diskmax, unsigned size, int faila, unsigned char* zero)
{
unsigned char *p, *q, *dq;
const unsigned char* qmul; /* Q multiplier table */
p = dptrs[diskmax];
q = dptrs[diskmax+1];
/* Compute syndrome with zero for the missing data page. */
/* Use the dead data page as temporary storage for delta q. */
dq = dptrs[faila];
dptrs[faila] = zero;
dptrs[diskmax+1] = dq;
raid6_gen(dptrs, diskmax, size);
/* Restore pointer table */
dptrs[faila] = dq;
dptrs[diskmax+1] = q;
/* Now, pick the proper data tables */
qmul = raid6_gfmul[raid6_gfinv[raid6_gfexp[faila]]];
/* Now do it... */
while (size--) {
*p++ ^= *dq = qmul[*q ^ *dq];
q++;
dq++;
}
}
void raid_gen(unsigned level, unsigned char** buffer, unsigned diskmax, unsigned size)
{
if (level == 1) {
raid5_gen(buffer, diskmax, size);
} else {
raid6_gen(buffer, diskmax, size);
}
}
void raid_init(void)
{
raid5_gen = raid5_int32r2;
raid6_gen = raid6_int32r2;
#if defined(__i386__) || defined(__x86_64__)
if (cpu_has_mmx()) {
raid5_gen = raid5_mmxr4;
raid6_gen = raid6_mmxr2;
}
if (cpu_has_sse2()) {
#if defined(__x86_64__)
raid5_gen = raid5_sse2r8;
raid6_gen = raid6_sse2r4;
#else
raid5_gen = raid5_sse2r4;
raid6_gen = raid6_sse2r2;
#endif
}
#endif
}
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