/* -----------------------------------------------------------------------
*
* 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
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, Inc., 53 Temple Place Ste 330,
* Boston MA 02111-1307, USA; either version 2 of the License, or
* (at your option) any later version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
/*
* neon$#.c
*
* $#-way unrolled NEON intrinsics math RAID-6 instruction set
*
* This file is postprocessed using unroll.awk
*/
#include <arm_neon.h>
typedef uint8x16_t unative_t;
#define NSIZE sizeof(unative_t)
/*
* The SHLBYTE() operation shifts each byte left by 1, *not*
* rolling over into the next byte
*/
static inline unative_t SHLBYTE(unative_t v)
{
return vshlq_n_u8(v, 1);
}
/*
* The MASK() operation returns 0xFF in any byte for which the high
* bit is 1, 0x00 for any byte for which the high bit is 0.
*/
static inline unative_t MASK(unative_t v)
{
return (unative_t)vshrq_n_s8((int8x16_t)v, 7);
}
static inline unative_t PMUL(unative_t v, unative_t u)
{
return (unative_t)vmulq_p8((poly8x16_t)v, (poly8x16_t)u);
}
void raid6_neon$#_gen_syndrome_real(int disks, 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$$;
const unative_t x1d = vdupq_n_u8(0x1d);
z0 = disks - 3; /* Highest data disk */
p = dptr[z0+1]; /* XOR parity */
q = dptr[z0+2]; /* RS syndrome */
for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
wq$$ = wp$$ = vld1q_u8(&dptr[z0][d+$$*NSIZE]);
for ( z = z0-1 ; z >= 0 ; 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$$);
}
vst1q_u8(&p[d+NSIZE*$$], wp$$);
vst1q_u8(&q[d+NSIZE*$$], 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 = vdupq_n_u8(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 >= 3 ; z -= 4 ) {
w2$$ = vshrq_n_u8(wq$$, 4);
w1$$ = vshlq_n_u8(wq$$, 4);
w2$$ = PMUL(w2$$, x1d);
wq$$ = veorq_u8(w1$$, w2$$);
}
switch (z) {
case 2:
w2$$ = vshrq_n_u8(wq$$, 5);
w1$$ = vshlq_n_u8(wq$$, 3);
w2$$ = PMUL(w2$$, x1d);
wq$$ = veorq_u8(w1$$, w2$$);
break;
case 1:
w2$$ = vshrq_n_u8(wq$$, 6);
w1$$ = vshlq_n_u8(wq$$, 2);
w2$$ = PMUL(w2$$, x1d);
wq$$ = veorq_u8(w1$$, w2$$);
break;
case 0:
w2$$ = 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$$);
}
}
