From 751ba79cc552c146595cd439b21c4ff8998c3b69 Mon Sep 17 00:00:00 2001 From: Matt Brown Date: Fri, 4 Aug 2017 13:42:32 +1000 Subject: 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 Reviewed-by: Daniel Axtens [mpe: Add VPERMXOR macro so we can build with old binutils] Signed-off-by: Michael Ellerman --- lib/raid6/algos.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'lib/raid6/algos.c') diff --git a/lib/raid6/algos.c b/lib/raid6/algos.c index 476994723258..b2e681018145 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, -- cgit v1.2.3