From 0e833e697bcf4c2f3f7fb9fce39d08cd4439e5d7 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 1 Jul 2015 12:19:56 +1000 Subject: [PATCH] md/raid6: delta syndrome for ARM NEON 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 Signed-off-by: NeilBrown --- 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 d9ad6ee..7076ef1 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 1b9ed79..4fa51b7 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$$); + } +} -- 2.7.4