From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Wed, 24 Jun 2015 18:43:33 +0200 Subject: [PATCH] md/raid6: delta syndrome for ARM NEON Message-ID: <1435164213-25410-1-git-send-email-ard.biesheuvel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This implements XOR syndrome calculation using NEON intrinsics. As before, the module can be built for ARM and arm64 from the same source. Relative performance on a Cortex-A57 based system: raid6: int64x1 gen() 905 MB/s raid6: int64x1 xor() 881 MB/s raid6: int64x2 gen() 1343 MB/s raid6: int64x2 xor() 1286 MB/s raid6: int64x4 gen() 1896 MB/s raid6: int64x4 xor() 1321 MB/s raid6: int64x8 gen() 1773 MB/s raid6: int64x8 xor() 1165 MB/s raid6: neonx1 gen() 1834 MB/s raid6: neonx1 xor() 1278 MB/s raid6: neonx2 gen() 2528 MB/s raid6: neonx2 xor() 1942 MB/s raid6: neonx4 gen() 2888 MB/s raid6: neonx4 xor() 2334 MB/s raid6: neonx8 gen() 2957 MB/s raid6: neonx8 xor() 2232 MB/s raid6: using algorithm neonx8 gen() 2957 MB/s raid6: .... xor() 2232 MB/s, rmw enabled Cc: Markus Stockhausen Cc: Neil Brown Signed-off-by: Ard Biesheuvel --- lib/raid6/neon.c | 13 ++++++++++++- lib/raid6/neon.uc | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+), 1 deletion(-) diff --git a/lib/raid6/neon.c b/lib/raid6/neon.c index d9ad6ee284f4..7076ef1ba3dd 100644 --- a/lib/raid6/neon.c +++ b/lib/raid6/neon.c @@ -40,9 +40,20 @@ (unsigned long)bytes, ptrs); \ kernel_neon_end(); \ } \ + static void raid6_neon ## _n ## _xor_syndrome(int disks, \ + int start, int stop, \ + size_t bytes, void **ptrs) \ + { \ + void raid6_neon ## _n ## _xor_syndrome_real(int, \ + int, int, unsigned long, void**); \ + kernel_neon_begin(); \ + raid6_neon ## _n ## _xor_syndrome_real(disks, \ + start, stop, (unsigned long)bytes, ptrs); \ + kernel_neon_end(); \ + } \ struct raid6_calls const raid6_neonx ## _n = { \ raid6_neon ## _n ## _gen_syndrome, \ - NULL, /* XOR not yet implemented */ \ + raid6_neon ## _n ## _xor_syndrome, \ raid6_have_neon, \ "neonx" #_n, \ 0 \ diff --git a/lib/raid6/neon.uc b/lib/raid6/neon.uc index 1b9ed793342d..4fa51b761dd0 100644 --- a/lib/raid6/neon.uc +++ b/lib/raid6/neon.uc @@ -3,6 +3,7 @@ * neon.uc - RAID-6 syndrome calculation using ARM NEON instructions * * Copyright (C) 2012 Rob Herring + * Copyright (C) 2015 Linaro Ltd. * * Based on altivec.uc: * Copyright 2002-2004 H. Peter Anvin - All Rights Reserved @@ -78,3 +79,48 @@ void raid6_neon$#_gen_syndrome_real(int disks, unsigned long bytes, void **ptrs) vst1q_u8(&q[d+NSIZE*$$], wq$$); } } + +void raid6_neon$#_xor_syndrome_real(int disks, int start, int stop, + unsigned long bytes, void **ptrs) +{ + uint8_t **dptr = (uint8_t **)ptrs; + uint8_t *p, *q; + int d, z, z0; + + register unative_t wd$$, wq$$, wp$$, w1$$, w2$$; + const unative_t x1d = NBYTES(0x1d); + + z0 = stop; /* P/Q right side optimization */ + p = dptr[disks-2]; /* XOR parity */ + q = dptr[disks-1]; /* RS syndrome */ + + for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { + wq$$ = vld1q_u8(&dptr[z0][d+$$*NSIZE]); + wp$$ = veorq_u8(vld1q_u8(&p[d+$$*NSIZE]), wq$$); + + /* P/Q data pages */ + for ( z = z0-1 ; z >= start ; z-- ) { + wd$$ = vld1q_u8(&dptr[z][d+$$*NSIZE]); + wp$$ = veorq_u8(wp$$, wd$$); + w2$$ = MASK(wq$$); + w1$$ = SHLBYTE(wq$$); + + w2$$ = vandq_u8(w2$$, x1d); + w1$$ = veorq_u8(w1$$, w2$$); + wq$$ = veorq_u8(w1$$, wd$$); + } + /* P/Q left side optimization */ + for ( z = start-1 ; z >= 0 ; z-- ) { + w2$$ = MASK(wq$$); + w1$$ = SHLBYTE(wq$$); + + w2$$ = vandq_u8(w2$$, x1d); + wq$$ = veorq_u8(w1$$, w2$$); + } + w1$$ = vld1q_u8(&q[d+NSIZE*$$]); + wq$$ = veorq_u8(wq$$, w1$$); + + vst1q_u8(&p[d+NSIZE*$$], wp$$); + vst1q_u8(&q[d+NSIZE*$$], wq$$); + } +} -- 1.9.1