1/* -*- linux-c -*- ------------------------------------------------------- * 2 * 3 * Copyright 2002-2004 H. Peter Anvin - All Rights Reserved 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation, Inc., 53 Temple Place Ste 330, 8 * Boston MA 02111-1307, USA; either version 2 of the License, or 9 * (at your option) any later version; incorporated herein by reference. 10 * 11 * ----------------------------------------------------------------------- */ 12 13/* 14 * raid6altivec$#.c 15 * 16 * $#-way unrolled portable integer math RAID-6 instruction set 17 * 18 * This file is postprocessed using unroll.awk 19 * 20 * <benh> hpa: in process, 21 * you can just "steal" the vec unit with enable_kernel_altivec() (but 22 * bracked this with preempt_disable/enable or in a lock) 23 */ 24 25#include "algos.h" 26 27#include <altivec.h> 28#include <asm/cputable.h> 29#include <asm/switch_to.h> 30 31/* 32 * This is the C data type to use. We use a vector of 33 * signed char so vec_cmpgt() will generate the right 34 * instruction. 35 */ 36 37typedef vector signed char unative_t; 38 39#define NBYTES(x) ((vector signed char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x}) 40#define NSIZE sizeof(unative_t) 41 42/* 43 * The SHLBYTE() operation shifts each byte left by 1, *not* 44 * rolling over into the next byte 45 */ 46static inline __attribute_const__ unative_t SHLBYTE(unative_t v) 47{ 48 return vec_add(v,v); 49} 50 51/* 52 * The MASK() operation returns 0xFF in any byte for which the high 53 * bit is 1, 0x00 for any byte for which the high bit is 0. 54 */ 55static inline __attribute_const__ unative_t MASK(unative_t v) 56{ 57 unative_t zv = NBYTES(0); 58 59 /* vec_cmpgt returns a vector bool char; thus the need for the cast */ 60 return (unative_t)vec_cmpgt(zv, v); 61} 62 63 64/* This is noinline to make damned sure that gcc doesn't move any of the 65 Altivec code around the enable/disable code */ 66static void noinline 67raid6_altivec$#_gen_syndrome_real(int disks, size_t bytes, void **ptrs) 68{ 69 u8 **dptr = (u8 **)ptrs; 70 u8 *p, *q; 71 int d, z, z0; 72 73 unative_t wd$$, wq$$, wp$$, w1$$, w2$$; 74 unative_t x1d = NBYTES(0x1d); 75 76 z0 = disks - 3; /* Highest data disk */ 77 p = dptr[z0+1]; /* XOR parity */ 78 q = dptr[z0+2]; /* RS syndrome */ 79 80 for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { 81 wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; 82 for ( z = z0-1 ; z >= 0 ; z-- ) { 83 wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; 84 wp$$ = vec_xor(wp$$, wd$$); 85 w2$$ = MASK(wq$$); 86 w1$$ = SHLBYTE(wq$$); 87 w2$$ = vec_and(w2$$, x1d); 88 w1$$ = vec_xor(w1$$, w2$$); 89 wq$$ = vec_xor(w1$$, wd$$); 90 } 91 *(unative_t *)&p[d+NSIZE*$$] = wp$$; 92 *(unative_t *)&q[d+NSIZE*$$] = wq$$; 93 } 94} 95 96static void raid6_altivec$#_gen_syndrome(int disks, size_t bytes, void **ptrs) 97{ 98 preempt_disable(); 99 enable_kernel_altivec(); 100 101 raid6_altivec$#_gen_syndrome_real(disks, bytes, ptrs); 102 103 disable_kernel_altivec(); 104 preempt_enable(); 105} 106 107int raid6_have_altivec(void); 108#if $# == 1 109int raid6_have_altivec(void) 110{ 111 /* This assumes either all CPUs have Altivec or none does */ 112 return cpu_has_feature(CPU_FTR_ALTIVEC); 113} 114#endif 115 116const struct raid6_calls raid6_altivec$# = { 117 .gen_syndrome = raid6_altivec$#_gen_syndrome, 118 .valid = raid6_have_altivec, 119 .name = "altivecx$#", 120}; 121