Linux kernel stable tree (mirror) https://git.radix-linux.su/kernel/linux.git/atom?h=v6.12.80 2022-03-08T23:20:21+00:00 2022-03-08T23:20:21+00:00 Paul Menzel pmenzel@molgen.mpg.de 2022-02-08T15:21:50+00:00 urn:sha1:5b401e4e9ac4c6a62b9f6562d0250c1a56477ff2 On Ubuntu 21.10 (ppc64le) building raid6test with gcc (Ubuntu 11.2.0-7ubuntu2) 11.2.0 fails with the error below. gcc -I.. -I ../../../include -g -O2 \ -I../../../arch/powerpc/include -DCONFIG_ALTIVEC \ -c -o vpermxor1.o vpermxor1.c vpermxor1.c: In function ‘raid6_vpermxor1_gen_syndrome_real’: vpermxor1.c:64:29: error: expected string literal before ‘VPERMXOR’ 64 | asm(VPERMXOR(%0,%1,%2,%3):"=v"(wq0):"v"(gf_high), "v"(gf_low), "v"(wq0)); | ^~~~~~~~ make: *** [Makefile:58: vpermxor1.o] Error 1 So, include the header asm/ppc-opcode.h defining this macro also when not building the Linux kernel but only this too. Cc: Matt Brown <matthew.brown.dev@gmail.com> Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Song Liu <song@kernel.org> 2018-03-20T05:47:25+00:00 Matt Brown matthew.brown.dev@gmail.com 2017-08-04T03:42:32+00:00 urn:sha1:751ba79cc552c146595cd439b21c4ff8998c3b69 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>