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md/raid6: delta syndrome for ARM NEON

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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 <stockhausen@collogia.de>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NeilBrown <neilb@suse.com>
This commit is contained in:
Ard Biesheuvel 2015-07-01 12:19:56 +10:00 committed by NeilBrown
parent 199dc6ed51
commit 0e833e697b
2 changed files with 58 additions and 1 deletions
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13
lib/raid6/neon.c
View file

@ -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 \

46
lib/raid6/neon.uc
View file

@ -3,6 +3,7 @@
* neon.uc - RAID-6 syndrome calculation using ARM NEON instructions
*
* Copyright (C) 2012 Rob Herring
* Copyright (C) 2015 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* 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$$);
}
}