linux/lib/raid6/recov_neon_inner.c
Ard Biesheuvel 6ec4e2514d md/raid6: implement recovery using ARM NEON intrinsics
Provide a NEON accelerated implementation of the recovery algorithm,
which supersedes the default byte-by-byte one.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-09 18:52:07 +01:00

118 lines
2.6 KiB
C

/*
* Copyright (C) 2012 Intel Corporation
* Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* 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; version 2
* of the License.
*/
#include <arm_neon.h>
static const uint8x16_t x0f = {
0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f,
0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f,
};
#ifdef CONFIG_ARM
/*
* AArch32 does not provide this intrinsic natively because it does not
* implement the underlying instruction. AArch32 only provides a 64-bit
* wide vtbl.8 instruction, so use that instead.
*/
static uint8x16_t vqtbl1q_u8(uint8x16_t a, uint8x16_t b)
{
union {
uint8x16_t val;
uint8x8x2_t pair;
} __a = { a };
return vcombine_u8(vtbl2_u8(__a.pair, vget_low_u8(b)),
vtbl2_u8(__a.pair, vget_high_u8(b)));
}
#endif
void __raid6_2data_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dp,
uint8_t *dq, const uint8_t *pbmul,
const uint8_t *qmul)
{
uint8x16_t pm0 = vld1q_u8(pbmul);
uint8x16_t pm1 = vld1q_u8(pbmul + 16);
uint8x16_t qm0 = vld1q_u8(qmul);
uint8x16_t qm1 = vld1q_u8(qmul + 16);
/*
* while ( bytes-- ) {
* uint8_t px, qx, db;
*
* px = *p ^ *dp;
* qx = qmul[*q ^ *dq];
* *dq++ = db = pbmul[px] ^ qx;
* *dp++ = db ^ px;
* p++; q++;
* }
*/
while (bytes) {
uint8x16_t vx, vy, px, qx, db;
px = veorq_u8(vld1q_u8(p), vld1q_u8(dp));
vx = veorq_u8(vld1q_u8(q), vld1q_u8(dq));
vy = (uint8x16_t)vshrq_n_s16((int16x8_t)vx, 4);
vx = vqtbl1q_u8(qm0, vandq_u8(vx, x0f));
vy = vqtbl1q_u8(qm1, vandq_u8(vy, x0f));
qx = veorq_u8(vx, vy);
vy = (uint8x16_t)vshrq_n_s16((int16x8_t)px, 4);
vx = vqtbl1q_u8(pm0, vandq_u8(px, x0f));
vy = vqtbl1q_u8(pm1, vandq_u8(vy, x0f));
vx = veorq_u8(vx, vy);
db = veorq_u8(vx, qx);
vst1q_u8(dq, db);
vst1q_u8(dp, veorq_u8(db, px));
bytes -= 16;
p += 16;
q += 16;
dp += 16;
dq += 16;
}
}
void __raid6_datap_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dq,
const uint8_t *qmul)
{
uint8x16_t qm0 = vld1q_u8(qmul);
uint8x16_t qm1 = vld1q_u8(qmul + 16);
/*
* while (bytes--) {
* *p++ ^= *dq = qmul[*q ^ *dq];
* q++; dq++;
* }
*/
while (bytes) {
uint8x16_t vx, vy;
vx = veorq_u8(vld1q_u8(q), vld1q_u8(dq));
vy = (uint8x16_t)vshrq_n_s16((int16x8_t)vx, 4);
vx = vqtbl1q_u8(qm0, vandq_u8(vx, x0f));
vy = vqtbl1q_u8(qm1, vandq_u8(vy, x0f));
vx = veorq_u8(vx, vy);
vy = veorq_u8(vx, vld1q_u8(p));
vst1q_u8(dq, vx);
vst1q_u8(p, vy);
bytes -= 16;
p += 16;
q += 16;
dq += 16;
}
}