alistair23-linux/lib/raid6/sse2.c
Markus Stockhausen a582564b24 md/raid6 algorithms: xor_syndrome() for SSE2
The second and (last) optimized XOR syndrome calculation. This version
supports right and left side optimization. All CPUs with architecture
older than Haswell will benefit from it.

It should be noted that SSE2 movntdq kills performance for memory areas
that are read and written simultaneously in chunks smaller than cache
line size. So use movdqa instead for P/Q writes in sse21 and sse22 XOR
functions.

Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22 08:00:42 +10:00

486 lines
16 KiB
C

/* -*- linux-c -*- ------------------------------------------------------- *
*
* 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,
* Boston MA 02111-1307, USA; either version 2 of the License, or
* (at your option) any later version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
/*
* raid6/sse2.c
*
* SSE-2 implementation of RAID-6 syndrome functions
*
*/
#include <linux/raid/pq.h>
#include "x86.h"
static const struct raid6_sse_constants {
u64 x1d[2];
} raid6_sse_constants __attribute__((aligned(16))) = {
{ 0x1d1d1d1d1d1d1d1dULL, 0x1d1d1d1d1d1d1d1dULL },
};
static int raid6_have_sse2(void)
{
/* Not really boot_cpu but "all_cpus" */
return boot_cpu_has(X86_FEATURE_MMX) &&
boot_cpu_has(X86_FEATURE_FXSR) &&
boot_cpu_has(X86_FEATURE_XMM) &&
boot_cpu_has(X86_FEATURE_XMM2);
}
/*
* Plain SSE2 implementation
*/
static void raid6_sse21_gen_syndrome(int disks, size_t bytes, void **ptrs)
{
u8 **dptr = (u8 **)ptrs;
u8 *p, *q;
int d, z, z0;
z0 = disks - 3; /* Highest data disk */
p = dptr[z0+1]; /* XOR parity */
q = dptr[z0+2]; /* RS syndrome */
kernel_fpu_begin();
asm volatile("movdqa %0,%%xmm0" : : "m" (raid6_sse_constants.x1d[0]));
asm volatile("pxor %xmm5,%xmm5"); /* Zero temp */
for ( d = 0 ; d < bytes ; d += 16 ) {
asm volatile("prefetchnta %0" : : "m" (dptr[z0][d]));
asm volatile("movdqa %0,%%xmm2" : : "m" (dptr[z0][d])); /* P[0] */
asm volatile("prefetchnta %0" : : "m" (dptr[z0-1][d]));
asm volatile("movdqa %xmm2,%xmm4"); /* Q[0] */
asm volatile("movdqa %0,%%xmm6" : : "m" (dptr[z0-1][d]));
for ( z = z0-2 ; z >= 0 ; z-- ) {
asm volatile("prefetchnta %0" : : "m" (dptr[z][d]));
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pxor %xmm6,%xmm2");
asm volatile("pxor %xmm6,%xmm4");
asm volatile("movdqa %0,%%xmm6" : : "m" (dptr[z][d]));
}
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pxor %xmm6,%xmm2");
asm volatile("pxor %xmm6,%xmm4");
asm volatile("movntdq %%xmm2,%0" : "=m" (p[d]));
asm volatile("pxor %xmm2,%xmm2");
asm volatile("movntdq %%xmm4,%0" : "=m" (q[d]));
asm volatile("pxor %xmm4,%xmm4");
}
asm volatile("sfence" : : : "memory");
kernel_fpu_end();
}
static void raid6_sse21_xor_syndrome(int disks, int start, int stop,
size_t bytes, void **ptrs)
{
u8 **dptr = (u8 **)ptrs;
u8 *p, *q;
int d, z, z0;
z0 = stop; /* P/Q right side optimization */
p = dptr[disks-2]; /* XOR parity */
q = dptr[disks-1]; /* RS syndrome */
kernel_fpu_begin();
asm volatile("movdqa %0,%%xmm0" : : "m" (raid6_sse_constants.x1d[0]));
for ( d = 0 ; d < bytes ; d += 16 ) {
asm volatile("movdqa %0,%%xmm4" :: "m" (dptr[z0][d]));
asm volatile("movdqa %0,%%xmm2" : : "m" (p[d]));
asm volatile("pxor %xmm4,%xmm2");
/* P/Q data pages */
for ( z = z0-1 ; z >= start ; z-- ) {
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("movdqa %0,%%xmm5" :: "m" (dptr[z][d]));
asm volatile("pxor %xmm5,%xmm2");
asm volatile("pxor %xmm5,%xmm4");
}
/* P/Q left side optimization */
for ( z = start-1 ; z >= 0 ; z-- ) {
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pxor %xmm5,%xmm4");
}
asm volatile("pxor %0,%%xmm4" : : "m" (q[d]));
/* Don't use movntdq for r/w memory area < cache line */
asm volatile("movdqa %%xmm4,%0" : "=m" (q[d]));
asm volatile("movdqa %%xmm2,%0" : "=m" (p[d]));
}
asm volatile("sfence" : : : "memory");
kernel_fpu_end();
}
const struct raid6_calls raid6_sse2x1 = {
raid6_sse21_gen_syndrome,
raid6_sse21_xor_syndrome,
raid6_have_sse2,
"sse2x1",
1 /* Has cache hints */
};
/*
* Unrolled-by-2 SSE2 implementation
*/
static void raid6_sse22_gen_syndrome(int disks, size_t bytes, void **ptrs)
{
u8 **dptr = (u8 **)ptrs;
u8 *p, *q;
int d, z, z0;
z0 = disks - 3; /* Highest data disk */
p = dptr[z0+1]; /* XOR parity */
q = dptr[z0+2]; /* RS syndrome */
kernel_fpu_begin();
asm volatile("movdqa %0,%%xmm0" : : "m" (raid6_sse_constants.x1d[0]));
asm volatile("pxor %xmm5,%xmm5"); /* Zero temp */
asm volatile("pxor %xmm7,%xmm7"); /* Zero temp */
/* We uniformly assume a single prefetch covers at least 32 bytes */
for ( d = 0 ; d < bytes ; d += 32 ) {
asm volatile("prefetchnta %0" : : "m" (dptr[z0][d]));
asm volatile("movdqa %0,%%xmm2" : : "m" (dptr[z0][d])); /* P[0] */
asm volatile("movdqa %0,%%xmm3" : : "m" (dptr[z0][d+16])); /* P[1] */
asm volatile("movdqa %xmm2,%xmm4"); /* Q[0] */
asm volatile("movdqa %xmm3,%xmm6"); /* Q[1] */
for ( z = z0-1 ; z >= 0 ; z-- ) {
asm volatile("prefetchnta %0" : : "m" (dptr[z][d]));
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("pcmpgtb %xmm6,%xmm7");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("paddb %xmm6,%xmm6");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pand %xmm0,%xmm7");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
asm volatile("movdqa %0,%%xmm5" : : "m" (dptr[z][d]));
asm volatile("movdqa %0,%%xmm7" : : "m" (dptr[z][d+16]));
asm volatile("pxor %xmm5,%xmm2");
asm volatile("pxor %xmm7,%xmm3");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pxor %xmm7,%xmm7");
}
asm volatile("movntdq %%xmm2,%0" : "=m" (p[d]));
asm volatile("movntdq %%xmm3,%0" : "=m" (p[d+16]));
asm volatile("movntdq %%xmm4,%0" : "=m" (q[d]));
asm volatile("movntdq %%xmm6,%0" : "=m" (q[d+16]));
}
asm volatile("sfence" : : : "memory");
kernel_fpu_end();
}
static void raid6_sse22_xor_syndrome(int disks, int start, int stop,
size_t bytes, void **ptrs)
{
u8 **dptr = (u8 **)ptrs;
u8 *p, *q;
int d, z, z0;
z0 = stop; /* P/Q right side optimization */
p = dptr[disks-2]; /* XOR parity */
q = dptr[disks-1]; /* RS syndrome */
kernel_fpu_begin();
asm volatile("movdqa %0,%%xmm0" : : "m" (raid6_sse_constants.x1d[0]));
for ( d = 0 ; d < bytes ; d += 32 ) {
asm volatile("movdqa %0,%%xmm4" :: "m" (dptr[z0][d]));
asm volatile("movdqa %0,%%xmm6" :: "m" (dptr[z0][d+16]));
asm volatile("movdqa %0,%%xmm2" : : "m" (p[d]));
asm volatile("movdqa %0,%%xmm3" : : "m" (p[d+16]));
asm volatile("pxor %xmm4,%xmm2");
asm volatile("pxor %xmm6,%xmm3");
/* P/Q data pages */
for ( z = z0-1 ; z >= start ; z-- ) {
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pxor %xmm7,%xmm7");
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("pcmpgtb %xmm6,%xmm7");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("paddb %xmm6,%xmm6");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pand %xmm0,%xmm7");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
asm volatile("movdqa %0,%%xmm5" :: "m" (dptr[z][d]));
asm volatile("movdqa %0,%%xmm7" :: "m" (dptr[z][d+16]));
asm volatile("pxor %xmm5,%xmm2");
asm volatile("pxor %xmm7,%xmm3");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
}
/* P/Q left side optimization */
for ( z = start-1 ; z >= 0 ; z-- ) {
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pxor %xmm7,%xmm7");
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("pcmpgtb %xmm6,%xmm7");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("paddb %xmm6,%xmm6");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pand %xmm0,%xmm7");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
}
asm volatile("pxor %0,%%xmm4" : : "m" (q[d]));
asm volatile("pxor %0,%%xmm6" : : "m" (q[d+16]));
/* Don't use movntdq for r/w memory area < cache line */
asm volatile("movdqa %%xmm4,%0" : "=m" (q[d]));
asm volatile("movdqa %%xmm6,%0" : "=m" (q[d+16]));
asm volatile("movdqa %%xmm2,%0" : "=m" (p[d]));
asm volatile("movdqa %%xmm3,%0" : "=m" (p[d+16]));
}
asm volatile("sfence" : : : "memory");
kernel_fpu_end();
}
const struct raid6_calls raid6_sse2x2 = {
raid6_sse22_gen_syndrome,
raid6_sse22_xor_syndrome,
raid6_have_sse2,
"sse2x2",
1 /* Has cache hints */
};
#ifdef CONFIG_X86_64
/*
* Unrolled-by-4 SSE2 implementation
*/
static void raid6_sse24_gen_syndrome(int disks, size_t bytes, void **ptrs)
{
u8 **dptr = (u8 **)ptrs;
u8 *p, *q;
int d, z, z0;
z0 = disks - 3; /* Highest data disk */
p = dptr[z0+1]; /* XOR parity */
q = dptr[z0+2]; /* RS syndrome */
kernel_fpu_begin();
asm volatile("movdqa %0,%%xmm0" :: "m" (raid6_sse_constants.x1d[0]));
asm volatile("pxor %xmm2,%xmm2"); /* P[0] */
asm volatile("pxor %xmm3,%xmm3"); /* P[1] */
asm volatile("pxor %xmm4,%xmm4"); /* Q[0] */
asm volatile("pxor %xmm5,%xmm5"); /* Zero temp */
asm volatile("pxor %xmm6,%xmm6"); /* Q[1] */
asm volatile("pxor %xmm7,%xmm7"); /* Zero temp */
asm volatile("pxor %xmm10,%xmm10"); /* P[2] */
asm volatile("pxor %xmm11,%xmm11"); /* P[3] */
asm volatile("pxor %xmm12,%xmm12"); /* Q[2] */
asm volatile("pxor %xmm13,%xmm13"); /* Zero temp */
asm volatile("pxor %xmm14,%xmm14"); /* Q[3] */
asm volatile("pxor %xmm15,%xmm15"); /* Zero temp */
for ( d = 0 ; d < bytes ; d += 64 ) {
for ( z = z0 ; z >= 0 ; z-- ) {
/* The second prefetch seems to improve performance... */
asm volatile("prefetchnta %0" :: "m" (dptr[z][d]));
asm volatile("prefetchnta %0" :: "m" (dptr[z][d+32]));
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("pcmpgtb %xmm6,%xmm7");
asm volatile("pcmpgtb %xmm12,%xmm13");
asm volatile("pcmpgtb %xmm14,%xmm15");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("paddb %xmm6,%xmm6");
asm volatile("paddb %xmm12,%xmm12");
asm volatile("paddb %xmm14,%xmm14");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pand %xmm0,%xmm7");
asm volatile("pand %xmm0,%xmm13");
asm volatile("pand %xmm0,%xmm15");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
asm volatile("pxor %xmm13,%xmm12");
asm volatile("pxor %xmm15,%xmm14");
asm volatile("movdqa %0,%%xmm5" :: "m" (dptr[z][d]));
asm volatile("movdqa %0,%%xmm7" :: "m" (dptr[z][d+16]));
asm volatile("movdqa %0,%%xmm13" :: "m" (dptr[z][d+32]));
asm volatile("movdqa %0,%%xmm15" :: "m" (dptr[z][d+48]));
asm volatile("pxor %xmm5,%xmm2");
asm volatile("pxor %xmm7,%xmm3");
asm volatile("pxor %xmm13,%xmm10");
asm volatile("pxor %xmm15,%xmm11");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
asm volatile("pxor %xmm13,%xmm12");
asm volatile("pxor %xmm15,%xmm14");
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pxor %xmm7,%xmm7");
asm volatile("pxor %xmm13,%xmm13");
asm volatile("pxor %xmm15,%xmm15");
}
asm volatile("movntdq %%xmm2,%0" : "=m" (p[d]));
asm volatile("pxor %xmm2,%xmm2");
asm volatile("movntdq %%xmm3,%0" : "=m" (p[d+16]));
asm volatile("pxor %xmm3,%xmm3");
asm volatile("movntdq %%xmm10,%0" : "=m" (p[d+32]));
asm volatile("pxor %xmm10,%xmm10");
asm volatile("movntdq %%xmm11,%0" : "=m" (p[d+48]));
asm volatile("pxor %xmm11,%xmm11");
asm volatile("movntdq %%xmm4,%0" : "=m" (q[d]));
asm volatile("pxor %xmm4,%xmm4");
asm volatile("movntdq %%xmm6,%0" : "=m" (q[d+16]));
asm volatile("pxor %xmm6,%xmm6");
asm volatile("movntdq %%xmm12,%0" : "=m" (q[d+32]));
asm volatile("pxor %xmm12,%xmm12");
asm volatile("movntdq %%xmm14,%0" : "=m" (q[d+48]));
asm volatile("pxor %xmm14,%xmm14");
}
asm volatile("sfence" : : : "memory");
kernel_fpu_end();
}
static void raid6_sse24_xor_syndrome(int disks, int start, int stop,
size_t bytes, void **ptrs)
{
u8 **dptr = (u8 **)ptrs;
u8 *p, *q;
int d, z, z0;
z0 = stop; /* P/Q right side optimization */
p = dptr[disks-2]; /* XOR parity */
q = dptr[disks-1]; /* RS syndrome */
kernel_fpu_begin();
asm volatile("movdqa %0,%%xmm0" :: "m" (raid6_sse_constants.x1d[0]));
for ( d = 0 ; d < bytes ; d += 64 ) {
asm volatile("movdqa %0,%%xmm4" :: "m" (dptr[z0][d]));
asm volatile("movdqa %0,%%xmm6" :: "m" (dptr[z0][d+16]));
asm volatile("movdqa %0,%%xmm12" :: "m" (dptr[z0][d+32]));
asm volatile("movdqa %0,%%xmm14" :: "m" (dptr[z0][d+48]));
asm volatile("movdqa %0,%%xmm2" : : "m" (p[d]));
asm volatile("movdqa %0,%%xmm3" : : "m" (p[d+16]));
asm volatile("movdqa %0,%%xmm10" : : "m" (p[d+32]));
asm volatile("movdqa %0,%%xmm11" : : "m" (p[d+48]));
asm volatile("pxor %xmm4,%xmm2");
asm volatile("pxor %xmm6,%xmm3");
asm volatile("pxor %xmm12,%xmm10");
asm volatile("pxor %xmm14,%xmm11");
/* P/Q data pages */
for ( z = z0-1 ; z >= start ; z-- ) {
asm volatile("prefetchnta %0" :: "m" (dptr[z][d]));
asm volatile("prefetchnta %0" :: "m" (dptr[z][d+32]));
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pxor %xmm7,%xmm7");
asm volatile("pxor %xmm13,%xmm13");
asm volatile("pxor %xmm15,%xmm15");
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("pcmpgtb %xmm6,%xmm7");
asm volatile("pcmpgtb %xmm12,%xmm13");
asm volatile("pcmpgtb %xmm14,%xmm15");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("paddb %xmm6,%xmm6");
asm volatile("paddb %xmm12,%xmm12");
asm volatile("paddb %xmm14,%xmm14");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pand %xmm0,%xmm7");
asm volatile("pand %xmm0,%xmm13");
asm volatile("pand %xmm0,%xmm15");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
asm volatile("pxor %xmm13,%xmm12");
asm volatile("pxor %xmm15,%xmm14");
asm volatile("movdqa %0,%%xmm5" :: "m" (dptr[z][d]));
asm volatile("movdqa %0,%%xmm7" :: "m" (dptr[z][d+16]));
asm volatile("movdqa %0,%%xmm13" :: "m" (dptr[z][d+32]));
asm volatile("movdqa %0,%%xmm15" :: "m" (dptr[z][d+48]));
asm volatile("pxor %xmm5,%xmm2");
asm volatile("pxor %xmm7,%xmm3");
asm volatile("pxor %xmm13,%xmm10");
asm volatile("pxor %xmm15,%xmm11");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
asm volatile("pxor %xmm13,%xmm12");
asm volatile("pxor %xmm15,%xmm14");
}
asm volatile("prefetchnta %0" :: "m" (q[d]));
asm volatile("prefetchnta %0" :: "m" (q[d+32]));
/* P/Q left side optimization */
for ( z = start-1 ; z >= 0 ; z-- ) {
asm volatile("pxor %xmm5,%xmm5");
asm volatile("pxor %xmm7,%xmm7");
asm volatile("pxor %xmm13,%xmm13");
asm volatile("pxor %xmm15,%xmm15");
asm volatile("pcmpgtb %xmm4,%xmm5");
asm volatile("pcmpgtb %xmm6,%xmm7");
asm volatile("pcmpgtb %xmm12,%xmm13");
asm volatile("pcmpgtb %xmm14,%xmm15");
asm volatile("paddb %xmm4,%xmm4");
asm volatile("paddb %xmm6,%xmm6");
asm volatile("paddb %xmm12,%xmm12");
asm volatile("paddb %xmm14,%xmm14");
asm volatile("pand %xmm0,%xmm5");
asm volatile("pand %xmm0,%xmm7");
asm volatile("pand %xmm0,%xmm13");
asm volatile("pand %xmm0,%xmm15");
asm volatile("pxor %xmm5,%xmm4");
asm volatile("pxor %xmm7,%xmm6");
asm volatile("pxor %xmm13,%xmm12");
asm volatile("pxor %xmm15,%xmm14");
}
asm volatile("movntdq %%xmm2,%0" : "=m" (p[d]));
asm volatile("movntdq %%xmm3,%0" : "=m" (p[d+16]));
asm volatile("movntdq %%xmm10,%0" : "=m" (p[d+32]));
asm volatile("movntdq %%xmm11,%0" : "=m" (p[d+48]));
asm volatile("pxor %0,%%xmm4" : : "m" (q[d]));
asm volatile("pxor %0,%%xmm6" : : "m" (q[d+16]));
asm volatile("pxor %0,%%xmm12" : : "m" (q[d+32]));
asm volatile("pxor %0,%%xmm14" : : "m" (q[d+48]));
asm volatile("movntdq %%xmm4,%0" : "=m" (q[d]));
asm volatile("movntdq %%xmm6,%0" : "=m" (q[d+16]));
asm volatile("movntdq %%xmm12,%0" : "=m" (q[d+32]));
asm volatile("movntdq %%xmm14,%0" : "=m" (q[d+48]));
}
asm volatile("sfence" : : : "memory");
kernel_fpu_end();
}
const struct raid6_calls raid6_sse2x4 = {
raid6_sse24_gen_syndrome,
raid6_sse24_xor_syndrome,
raid6_have_sse2,
"sse2x4",
1 /* Has cache hints */
};
#endif /* CONFIG_X86_64 */