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