diff options
author | Matt Brown <matthew.brown.dev@gmail.com> | 2017-08-04 13:42:32 +1000 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-03-20 16:47:25 +1100 |
commit | 751ba79cc552c146595cd439b21c4ff8998c3b69 (patch) | |
tree | fc7aa71ed1ca788ab3a9c553021f7c876ccd4115 /lib | |
parent | 7004263bd4f4c79da9ca2a1d04d38d4d6ed609ab (diff) | |
download | op-kernel-dev-751ba79cc552c146595cd439b21c4ff8998c3b69.zip op-kernel-dev-751ba79cc552c146595cd439b21c4ff8998c3b69.tar.gz |
lib/raid6/altivec: Add vpermxor implementation for raid6 Q syndrome
This patch uses the vpermxor instruction to optimise the raid6 Q
syndrome. This instruction was made available with POWER8, ISA version
2.07. It allows for both vperm and vxor instructions to be done in a
single instruction. This has been tested for correctness on a ppc64le
vm with a basic RAID6 setup containing 5 drives.
The performance benchmarks are from the raid6test in the
/lib/raid6/test directory. These results are from an IBM Firestone
machine with ppc64le architecture. The benchmark results show a 35%
speed increase over the best existing algorithm for powerpc (altivec).
The raid6test has also been run on a big-endian ppc64 vm to ensure it
also works for big-endian architectures.
Performance benchmarks:
raid6: altivecx4 gen() 18773 MB/s
raid6: altivecx8 gen() 19438 MB/s
raid6: vpermxor4 gen() 25112 MB/s
raid6: vpermxor8 gen() 26279 MB/s
Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
[mpe: Add VPERMXOR macro so we can build with old binutils]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/raid6/.gitignore | 1 | ||||
-rw-r--r-- | lib/raid6/Makefile | 27 | ||||
-rw-r--r-- | lib/raid6/algos.c | 4 | ||||
-rw-r--r-- | lib/raid6/test/Makefile | 17 | ||||
-rw-r--r-- | lib/raid6/vpermxor.uc | 105 |
5 files changed, 151 insertions, 3 deletions
diff --git a/lib/raid6/.gitignore b/lib/raid6/.gitignore index f01b1cb..3de0d89 100644 --- a/lib/raid6/.gitignore +++ b/lib/raid6/.gitignore @@ -4,3 +4,4 @@ int*.c tables.c neon?.c s390vx?.c +vpermxor*.c diff --git a/lib/raid6/Makefile b/lib/raid6/Makefile index 4add700..21f5944 100644 --- a/lib/raid6/Makefile +++ b/lib/raid6/Makefile @@ -5,7 +5,8 @@ raid6_pq-y += algos.o recov.o tables.o int1.o int2.o int4.o \ int8.o int16.o int32.o raid6_pq-$(CONFIG_X86) += recov_ssse3.o recov_avx2.o mmx.o sse1.o sse2.o avx2.o avx512.o recov_avx512.o -raid6_pq-$(CONFIG_ALTIVEC) += altivec1.o altivec2.o altivec4.o altivec8.o +raid6_pq-$(CONFIG_ALTIVEC) += altivec1.o altivec2.o altivec4.o altivec8.o \ + vpermxor1.o vpermxor2.o vpermxor4.o vpermxor8.o raid6_pq-$(CONFIG_KERNEL_MODE_NEON) += neon.o neon1.o neon2.o neon4.o neon8.o recov_neon.o recov_neon_inner.o raid6_pq-$(CONFIG_TILEGX) += tilegx8.o raid6_pq-$(CONFIG_S390) += s390vx8.o recov_s390xc.o @@ -91,6 +92,30 @@ $(obj)/altivec8.c: UNROLL := 8 $(obj)/altivec8.c: $(src)/altivec.uc $(src)/unroll.awk FORCE $(call if_changed,unroll) +CFLAGS_vpermxor1.o += $(altivec_flags) +targets += vpermxor1.c +$(obj)/vpermxor1.c: UNROLL := 1 +$(obj)/vpermxor1.c: $(src)/vpermxor.uc $(src)/unroll.awk FORCE + $(call if_changed,unroll) + +CFLAGS_vpermxor2.o += $(altivec_flags) +targets += vpermxor2.c +$(obj)/vpermxor2.c: UNROLL := 2 +$(obj)/vpermxor2.c: $(src)/vpermxor.uc $(src)/unroll.awk FORCE + $(call if_changed,unroll) + +CFLAGS_vpermxor4.o += $(altivec_flags) +targets += vpermxor4.c +$(obj)/vpermxor4.c: UNROLL := 4 +$(obj)/vpermxor4.c: $(src)/vpermxor.uc $(src)/unroll.awk FORCE + $(call if_changed,unroll) + +CFLAGS_vpermxor8.o += $(altivec_flags) +targets += vpermxor8.c +$(obj)/vpermxor8.c: UNROLL := 8 +$(obj)/vpermxor8.c: $(src)/vpermxor.uc $(src)/unroll.awk FORCE + $(call if_changed,unroll) + CFLAGS_neon1.o += $(NEON_FLAGS) targets += neon1.c $(obj)/neon1.c: UNROLL := 1 diff --git a/lib/raid6/algos.c b/lib/raid6/algos.c index 4769947..b2e6810 100644 --- a/lib/raid6/algos.c +++ b/lib/raid6/algos.c @@ -74,6 +74,10 @@ const struct raid6_calls * const raid6_algos[] = { &raid6_altivec2, &raid6_altivec4, &raid6_altivec8, + &raid6_vpermxor1, + &raid6_vpermxor2, + &raid6_vpermxor4, + &raid6_vpermxor8, #endif #if defined(CONFIG_TILEGX) &raid6_tilegx8, diff --git a/lib/raid6/test/Makefile b/lib/raid6/test/Makefile index be1010b..ef6d0e0 100644 --- a/lib/raid6/test/Makefile +++ b/lib/raid6/test/Makefile @@ -48,7 +48,8 @@ else gcc -c -x c - >&/dev/null && \ rm ./-.o && echo yes) ifeq ($(HAS_ALTIVEC),yes) - OBJS += altivec1.o altivec2.o altivec4.o altivec8.o + OBJS += altivec1.o altivec2.o altivec4.o altivec8.o \ + vpermxor1.o vpermxor2.o vpermxor4.o vpermxor8.o endif endif ifeq ($(ARCH),tilegx) @@ -98,6 +99,18 @@ altivec4.c: altivec.uc ../unroll.awk altivec8.c: altivec.uc ../unroll.awk $(AWK) ../unroll.awk -vN=8 < altivec.uc > $@ +vpermxor1.c: vpermxor.uc ../unroll.awk + $(AWK) ../unroll.awk -vN=1 < vpermxor.uc > $@ + +vpermxor2.c: vpermxor.uc ../unroll.awk + $(AWK) ../unroll.awk -vN=2 < vpermxor.uc > $@ + +vpermxor4.c: vpermxor.uc ../unroll.awk + $(AWK) ../unroll.awk -vN=4 < vpermxor.uc > $@ + +vpermxor8.c: vpermxor.uc ../unroll.awk + $(AWK) ../unroll.awk -vN=8 < vpermxor.uc > $@ + int1.c: int.uc ../unroll.awk $(AWK) ../unroll.awk -vN=1 < int.uc > $@ @@ -123,7 +136,7 @@ tables.c: mktables ./mktables > tables.c clean: - rm -f *.o *.a mktables mktables.c *.uc int*.c altivec*.c neon*.c tables.c raid6test + rm -f *.o *.a mktables mktables.c *.uc int*.c altivec*.c vpermxor*.c neon*.c tables.c raid6test rm -f tilegx*.c spotless: clean diff --git a/lib/raid6/vpermxor.uc b/lib/raid6/vpermxor.uc new file mode 100644 index 0000000..10475dc --- /dev/null +++ b/lib/raid6/vpermxor.uc @@ -0,0 +1,105 @@ +/* + * Copyright 2017, Matt Brown, IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * vpermxor$#.c + * + * Based on H. Peter Anvin's paper - The mathematics of RAID-6 + * + * $#-way unrolled portable integer math RAID-6 instruction set + * This file is postprocessed using unroll.awk + * + * vpermxor$#.c makes use of the vpermxor instruction to optimise the RAID6 Q + * syndrome calculations. + * This can be run on systems which have both Altivec and vpermxor instruction. + * + * This instruction was introduced in POWER8 - ISA v2.07. + */ + +#include <linux/raid/pq.h> +#ifdef CONFIG_ALTIVEC + +#include <altivec.h> +#ifdef __KERNEL__ +#include <asm/cputable.h> +#include <asm/ppc-opcode.h> +#include <asm/switch_to.h> +#endif + +typedef vector unsigned char unative_t; +#define NSIZE sizeof(unative_t) + +static const vector unsigned char gf_low = {0x1e, 0x1c, 0x1a, 0x18, 0x16, 0x14, + 0x12, 0x10, 0x0e, 0x0c, 0x0a, 0x08, + 0x06, 0x04, 0x02,0x00}; +static const vector unsigned char gf_high = {0xfd, 0xdd, 0xbd, 0x9d, 0x7d, 0x5d, + 0x3d, 0x1d, 0xe0, 0xc0, 0xa0, 0x80, + 0x60, 0x40, 0x20, 0x00}; + +static void noinline raid6_vpermxor$#_gen_syndrome_real(int disks, size_t bytes, + void **ptrs) +{ + u8 **dptr = (u8 **)ptrs; + u8 *p, *q; + int d, z, z0; + unative_t wp$$, wq$$, wd$$; + + z0 = disks - 3; /* Highest data disk */ + p = dptr[z0+1]; /* XOR parity */ + q = dptr[z0+2]; /* RS syndrome */ + + for (d = 0; d < bytes; d += NSIZE*$#) { + wp$$ = wq$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; + + for (z = z0-1; z>=0; z--) { + wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; + /* P syndrome */ + wp$$ = vec_xor(wp$$, wd$$); + + /* Q syndrome */ + asm(VPERMXOR(%0,%1,%2,%3):"=v"(wq$$):"v"(gf_high), "v"(gf_low), "v"(wq$$)); + wq$$ = vec_xor(wq$$, wd$$); + } + *(unative_t *)&p[d+NSIZE*$$] = wp$$; + *(unative_t *)&q[d+NSIZE*$$] = wq$$; + } +} + +static void raid6_vpermxor$#_gen_syndrome(int disks, size_t bytes, void **ptrs) +{ + preempt_disable(); + enable_kernel_altivec(); + + raid6_vpermxor$#_gen_syndrome_real(disks, bytes, ptrs); + + disable_kernel_altivec(); + preempt_enable(); +} + +int raid6_have_altivec_vpermxor(void); +#if $# == 1 +int raid6_have_altivec_vpermxor(void) +{ + /* Check if arch has both altivec and the vpermxor instructions */ +# ifdef __KERNEL__ + return (cpu_has_feature(CPU_FTR_ALTIVEC_COMP) && + cpu_has_feature(CPU_FTR_ARCH_207S)); +# else + return 1; +#endif + +} +#endif + +const struct raid6_calls raid6_vpermxor$# = { + raid6_vpermxor$#_gen_syndrome, + NULL, + raid6_have_altivec_vpermxor, + "vpermxor$#", + 0 +}; +#endif |