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 * $#-way unrolled portable integer math RAID-6 instruction set 17 * 18 * This file is postprocessed using unroll.awk 19 * 20 * <benh> hpa: in process, 21 * you can just "steal" the vec unit with enable_kernel_altivec() (but 22 * bracked this with preempt_disable/enable or in a lock) 23 */ 24 25#include <linux/raid/pq.h> 26 27#ifdef CONFIG_ALTIVEC 28 29#include <altivec.h> 30#ifdef __KERNEL__ 31# include <asm/cputable.h> 32# include <asm/switch_to.h> 33#endif /* __KERNEL__ */ 34 35/* 36 * This is the C data type to use. We use a vector of 37 * signed char so vec_cmpgt() will generate the right 38 * instruction. 39 */ 40 41typedef vector signed char unative_t; 42 43#define NBYTES(x) ((vector signed char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x}) 44#define NSIZE sizeof(unative_t) 45 46/* 47 * The SHLBYTE() operation shifts each byte left by 1, *not* 48 * rolling over into the next byte 49 */ 50static inline __attribute_const__ unative_t SHLBYTE(unative_t v) 51{ 52 return vec_add(v,v); 53} 54 55/* 56 * The MASK() operation returns 0xFF in any byte for which the high 57 * bit is 1, 0x00 for any byte for which the high bit is 0. 58 */ 59static inline __attribute_const__ unative_t MASK(unative_t v) 60{ 61 unative_t zv = NBYTES(0); 62 63 /* vec_cmpgt returns a vector bool char; thus the need for the cast */ 64 return (unative_t)vec_cmpgt(zv, v); 65} 66 67 68/* This is noinline to make damned sure that gcc doesn't move any of the 69 Altivec code around the enable/disable code */ 70static void noinline 71raid6_altivec$#_gen_syndrome_real(int disks, size_t bytes, void **ptrs) 72{ 73 u8 **dptr = (u8 **)ptrs; 74 u8 *p, *q; 75 int d, z, z0; 76 77 unative_t wd$$, wq$$, wp$$, w1$$, w2$$; 78 unative_t x1d = NBYTES(0x1d); 79 80 z0 = disks - 3; /* Highest data disk */ 81 p = dptr[z0+1]; /* XOR parity */ 82 q = dptr[z0+2]; /* RS syndrome */ 83 84 for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { 85 wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; 86 for ( z = z0-1 ; z >= 0 ; z-- ) { 87 wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; 88 wp$$ = vec_xor(wp$$, wd$$); 89 w2$$ = MASK(wq$$); 90 w1$$ = SHLBYTE(wq$$); 91 w2$$ = vec_and(w2$$, x1d); 92 w1$$ = vec_xor(w1$$, w2$$); 93 wq$$ = vec_xor(w1$$, wd$$); 94 } 95 *(unative_t *)&p[d+NSIZE*$$] = wp$$; 96 *(unative_t *)&q[d+NSIZE*$$] = wq$$; 97 } 98} 99 100static void raid6_altivec$#_gen_syndrome(int disks, size_t bytes, void **ptrs) 101{ 102 preempt_disable(); 103 enable_kernel_altivec(); 104 105 raid6_altivec$#_gen_syndrome_real(disks, bytes, ptrs); 106 107 disable_kernel_altivec(); 108 preempt_enable(); 109} 110 111int raid6_have_altivec(void); 112#if $# == 1 113int raid6_have_altivec(void) 114{ 115 /* This assumes either all CPUs have Altivec or none does */ 116# ifdef __KERNEL__ 117 return cpu_has_feature(CPU_FTR_ALTIVEC); 118# else 119 return 1; 120# endif 121} 122#endif 123 124const struct raid6_calls raid6_altivec$# = { 125 raid6_altivec$#_gen_syndrome, 126 NULL, /* XOR not yet implemented */ 127 raid6_have_altivec, 128 "altivecx$#", 129 0 130}; 131 132#endif /* CONFIG_ALTIVEC */ 133