1/* ----------------------------------------------------------------------- 2 * 3 * neon.uc - RAID-6 syndrome calculation using ARM NEON instructions 4 * 5 * Copyright (C) 2012 Rob Herring 6 * 7 * Based on altivec.uc: 8 * Copyright 2002-2004 H. Peter Anvin - All Rights Reserved 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation, Inc., 53 Temple Place Ste 330, 13 * Boston MA 02111-1307, USA; either version 2 of the License, or 14 * (at your option) any later version; incorporated herein by reference. 15 * 16 * ----------------------------------------------------------------------- */ 17 18/* 19 * neon$#.c 20 * 21 * $#-way unrolled NEON intrinsics math RAID-6 instruction set 22 * 23 * This file is postprocessed using unroll.awk 24 */ 25 26#include <arm_neon.h> 27 28typedef uint8x16_t unative_t; 29 30#define NBYTES(x) ((unative_t){x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x}) 31#define NSIZE sizeof(unative_t) 32 33/* 34 * The SHLBYTE() operation shifts each byte left by 1, *not* 35 * rolling over into the next byte 36 */ 37static inline unative_t SHLBYTE(unative_t v) 38{ 39 return vshlq_n_u8(v, 1); 40} 41 42/* 43 * The MASK() operation returns 0xFF in any byte for which the high 44 * bit is 1, 0x00 for any byte for which the high bit is 0. 45 */ 46static inline unative_t MASK(unative_t v) 47{ 48 const uint8x16_t temp = NBYTES(0); 49 return (unative_t)vcltq_s8((int8x16_t)v, (int8x16_t)temp); 50} 51 52void raid6_neon$#_gen_syndrome_real(int disks, unsigned long bytes, void **ptrs) 53{ 54 uint8_t **dptr = (uint8_t **)ptrs; 55 uint8_t *p, *q; 56 int d, z, z0; 57 58 register unative_t wd$$, wq$$, wp$$, w1$$, w2$$; 59 const unative_t x1d = NBYTES(0x1d); 60 61 z0 = disks - 3; /* Highest data disk */ 62 p = dptr[z0+1]; /* XOR parity */ 63 q = dptr[z0+2]; /* RS syndrome */ 64 65 for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { 66 wq$$ = wp$$ = vld1q_u8(&dptr[z0][d+$$*NSIZE]); 67 for ( z = z0-1 ; z >= 0 ; z-- ) { 68 wd$$ = vld1q_u8(&dptr[z][d+$$*NSIZE]); 69 wp$$ = veorq_u8(wp$$, wd$$); 70 w2$$ = MASK(wq$$); 71 w1$$ = SHLBYTE(wq$$); 72 73 w2$$ = vandq_u8(w2$$, x1d); 74 w1$$ = veorq_u8(w1$$, w2$$); 75 wq$$ = veorq_u8(w1$$, wd$$); 76 } 77 vst1q_u8(&p[d+NSIZE*$$], wp$$); 78 vst1q_u8(&q[d+NSIZE*$$], wq$$); 79 } 80} 81