powerpc: Add VMX optimised xor for RAID5

Add a VMX optimised xor, used primarily for RAID5. On a POWER7 blade
this is a decent win:

   32regs    : 17932.800 MB/sec
   altivec   : 19724.800 MB/sec

The bigger gain is when the same test is run in SMT4 mode, as it
would if there was a lot of work going on:

   8regs     :  8377.600 MB/sec
   altivec   : 15801.600 MB/sec

I tested this against an array created without the patch, and also
verified it worked as expected on a little endian kernel.

[ Fix !CONFIG_ALTIVEC build -- BenH ]

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Anton Blanchard 2013-10-14 21:03:58 +11:00 committed by Benjamin Herrenschmidt
parent 07fb41a752
commit ef1313deaf
3 changed files with 247 additions and 0 deletions

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@ -1 +1,68 @@
/*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2012
*
* Author: Anton Blanchard <anton@au.ibm.com>
*/
#ifndef _ASM_POWERPC_XOR_H
#define _ASM_POWERPC_XOR_H
#ifdef CONFIG_ALTIVEC
#include <asm/cputable.h>
void xor_altivec_2(unsigned long bytes, unsigned long *v1_in,
unsigned long *v2_in);
void xor_altivec_3(unsigned long bytes, unsigned long *v1_in,
unsigned long *v2_in, unsigned long *v3_in);
void xor_altivec_4(unsigned long bytes, unsigned long *v1_in,
unsigned long *v2_in, unsigned long *v3_in,
unsigned long *v4_in);
void xor_altivec_5(unsigned long bytes, unsigned long *v1_in,
unsigned long *v2_in, unsigned long *v3_in,
unsigned long *v4_in, unsigned long *v5_in);
static struct xor_block_template xor_block_altivec = {
.name = "altivec",
.do_2 = xor_altivec_2,
.do_3 = xor_altivec_3,
.do_4 = xor_altivec_4,
.do_5 = xor_altivec_5,
};
#define XOR_SPEED_ALTIVEC() \
do { \
if (cpu_has_feature(CPU_FTR_ALTIVEC)) \
xor_speed(&xor_block_altivec); \
} while (0)
#else
#define XOR_SPEED_ALTIVEC()
#endif
/* Also try the generic routines. */
#include <asm-generic/xor.h>
#undef XOR_TRY_TEMPLATES
#define XOR_TRY_TEMPLATES \
do { \
xor_speed(&xor_block_8regs); \
xor_speed(&xor_block_8regs_p); \
xor_speed(&xor_block_32regs); \
xor_speed(&xor_block_32regs_p); \
XOR_SPEED_ALTIVEC(); \
} while (0)
#endif /* _ASM_POWERPC_XOR_H */

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@ -39,3 +39,6 @@ obj-$(CONFIG_PPC_LIB_RHEAP) += rheap.o
obj-y += code-patching.o
obj-y += feature-fixups.o
obj-$(CONFIG_FTR_FIXUP_SELFTEST) += feature-fixups-test.o
obj-$(CONFIG_ALTIVEC) += xor_vmx.o
CFLAGS_xor_vmx.o += -maltivec -mabi=altivec

177
arch/powerpc/lib/xor_vmx.c Normal file
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@ -0,0 +1,177 @@
/*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2012
*
* Author: Anton Blanchard <anton@au.ibm.com>
*/
#include <altivec.h>
#include <linux/preempt.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <asm/switch_to.h>
typedef vector signed char unative_t;
#define DEFINE(V) \
unative_t *V = (unative_t *)V##_in; \
unative_t V##_0, V##_1, V##_2, V##_3
#define LOAD(V) \
do { \
V##_0 = V[0]; \
V##_1 = V[1]; \
V##_2 = V[2]; \
V##_3 = V[3]; \
} while (0)
#define STORE(V) \
do { \
V[0] = V##_0; \
V[1] = V##_1; \
V[2] = V##_2; \
V[3] = V##_3; \
} while (0)
#define XOR(V1, V2) \
do { \
V1##_0 = vec_xor(V1##_0, V2##_0); \
V1##_1 = vec_xor(V1##_1, V2##_1); \
V1##_2 = vec_xor(V1##_2, V2##_2); \
V1##_3 = vec_xor(V1##_3, V2##_3); \
} while (0)
void xor_altivec_2(unsigned long bytes, unsigned long *v1_in,
unsigned long *v2_in)
{
DEFINE(v1);
DEFINE(v2);
unsigned long lines = bytes / (sizeof(unative_t)) / 4;
preempt_disable();
enable_kernel_altivec();
do {
LOAD(v1);
LOAD(v2);
XOR(v1, v2);
STORE(v1);
v1 += 4;
v2 += 4;
} while (--lines > 0);
preempt_enable();
}
EXPORT_SYMBOL(xor_altivec_2);
void xor_altivec_3(unsigned long bytes, unsigned long *v1_in,
unsigned long *v2_in, unsigned long *v3_in)
{
DEFINE(v1);
DEFINE(v2);
DEFINE(v3);
unsigned long lines = bytes / (sizeof(unative_t)) / 4;
preempt_disable();
enable_kernel_altivec();
do {
LOAD(v1);
LOAD(v2);
LOAD(v3);
XOR(v1, v2);
XOR(v1, v3);
STORE(v1);
v1 += 4;
v2 += 4;
v3 += 4;
} while (--lines > 0);
preempt_enable();
}
EXPORT_SYMBOL(xor_altivec_3);
void xor_altivec_4(unsigned long bytes, unsigned long *v1_in,
unsigned long *v2_in, unsigned long *v3_in,
unsigned long *v4_in)
{
DEFINE(v1);
DEFINE(v2);
DEFINE(v3);
DEFINE(v4);
unsigned long lines = bytes / (sizeof(unative_t)) / 4;
preempt_disable();
enable_kernel_altivec();
do {
LOAD(v1);
LOAD(v2);
LOAD(v3);
LOAD(v4);
XOR(v1, v2);
XOR(v3, v4);
XOR(v1, v3);
STORE(v1);
v1 += 4;
v2 += 4;
v3 += 4;
v4 += 4;
} while (--lines > 0);
preempt_enable();
}
EXPORT_SYMBOL(xor_altivec_4);
void xor_altivec_5(unsigned long bytes, unsigned long *v1_in,
unsigned long *v2_in, unsigned long *v3_in,
unsigned long *v4_in, unsigned long *v5_in)
{
DEFINE(v1);
DEFINE(v2);
DEFINE(v3);
DEFINE(v4);
DEFINE(v5);
unsigned long lines = bytes / (sizeof(unative_t)) / 4;
preempt_disable();
enable_kernel_altivec();
do {
LOAD(v1);
LOAD(v2);
LOAD(v3);
LOAD(v4);
LOAD(v5);
XOR(v1, v2);
XOR(v3, v4);
XOR(v1, v5);
XOR(v1, v3);
STORE(v1);
v1 += 4;
v2 += 4;
v3 += 4;
v4 += 4;
v5 += 4;
} while (--lines > 0);
preempt_enable();
}
EXPORT_SYMBOL(xor_altivec_5);