1751ba79cSMatt Brown/* 2751ba79cSMatt Brown * Copyright 2017, Matt Brown, IBM Corp. 3751ba79cSMatt Brown * 4751ba79cSMatt Brown * This program is free software; you can redistribute it and/or 5751ba79cSMatt Brown * modify it under the terms of the GNU General Public License 6751ba79cSMatt Brown * as published by the Free Software Foundation; either version 7751ba79cSMatt Brown * 2 of the License, or (at your option) any later version. 8751ba79cSMatt Brown * 9751ba79cSMatt Brown * vpermxor$#.c 10751ba79cSMatt Brown * 11751ba79cSMatt Brown * Based on H. Peter Anvin's paper - The mathematics of RAID-6 12751ba79cSMatt Brown * 13751ba79cSMatt Brown * $#-way unrolled portable integer math RAID-6 instruction set 14751ba79cSMatt Brown * This file is postprocessed using unroll.awk 15751ba79cSMatt Brown * 16751ba79cSMatt Brown * vpermxor$#.c makes use of the vpermxor instruction to optimise the RAID6 Q 17751ba79cSMatt Brown * syndrome calculations. 18751ba79cSMatt Brown * This can be run on systems which have both Altivec and vpermxor instruction. 19751ba79cSMatt Brown * 20751ba79cSMatt Brown * This instruction was introduced in POWER8 - ISA v2.07. 21751ba79cSMatt Brown */ 22751ba79cSMatt Brown 23751ba79cSMatt Brown#include <linux/raid/pq.h> 24751ba79cSMatt Brown#ifdef CONFIG_ALTIVEC 25751ba79cSMatt Brown 26751ba79cSMatt Brown#include <altivec.h> 27*5b401e4eSPaul Menzel#include <asm/ppc-opcode.h> 28751ba79cSMatt Brown#ifdef __KERNEL__ 29751ba79cSMatt Brown#include <asm/cputable.h> 30751ba79cSMatt Brown#include <asm/switch_to.h> 31751ba79cSMatt Brown#endif 32751ba79cSMatt Brown 33751ba79cSMatt Browntypedef vector unsigned char unative_t; 34751ba79cSMatt Brown#define NSIZE sizeof(unative_t) 35751ba79cSMatt Brown 36751ba79cSMatt Brownstatic const vector unsigned char gf_low = {0x1e, 0x1c, 0x1a, 0x18, 0x16, 0x14, 37751ba79cSMatt Brown 0x12, 0x10, 0x0e, 0x0c, 0x0a, 0x08, 38751ba79cSMatt Brown 0x06, 0x04, 0x02,0x00}; 39751ba79cSMatt Brownstatic const vector unsigned char gf_high = {0xfd, 0xdd, 0xbd, 0x9d, 0x7d, 0x5d, 40751ba79cSMatt Brown 0x3d, 0x1d, 0xe0, 0xc0, 0xa0, 0x80, 41751ba79cSMatt Brown 0x60, 0x40, 0x20, 0x00}; 42751ba79cSMatt Brown 43751ba79cSMatt Brownstatic void noinline raid6_vpermxor$#_gen_syndrome_real(int disks, size_t bytes, 44751ba79cSMatt Brown void **ptrs) 45751ba79cSMatt Brown{ 46751ba79cSMatt Brown u8 **dptr = (u8 **)ptrs; 47751ba79cSMatt Brown u8 *p, *q; 48751ba79cSMatt Brown int d, z, z0; 49751ba79cSMatt Brown unative_t wp$$, wq$$, wd$$; 50751ba79cSMatt Brown 51751ba79cSMatt Brown z0 = disks - 3; /* Highest data disk */ 52751ba79cSMatt Brown p = dptr[z0+1]; /* XOR parity */ 53751ba79cSMatt Brown q = dptr[z0+2]; /* RS syndrome */ 54751ba79cSMatt Brown 55751ba79cSMatt Brown for (d = 0; d < bytes; d += NSIZE*$#) { 56751ba79cSMatt Brown wp$$ = wq$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; 57751ba79cSMatt Brown 58751ba79cSMatt Brown for (z = z0-1; z>=0; z--) { 59751ba79cSMatt Brown wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; 60751ba79cSMatt Brown /* P syndrome */ 61751ba79cSMatt Brown wp$$ = vec_xor(wp$$, wd$$); 62751ba79cSMatt Brown 63751ba79cSMatt Brown /* Q syndrome */ 64751ba79cSMatt Brown asm(VPERMXOR(%0,%1,%2,%3):"=v"(wq$$):"v"(gf_high), "v"(gf_low), "v"(wq$$)); 65751ba79cSMatt Brown wq$$ = vec_xor(wq$$, wd$$); 66751ba79cSMatt Brown } 67751ba79cSMatt Brown *(unative_t *)&p[d+NSIZE*$$] = wp$$; 68751ba79cSMatt Brown *(unative_t *)&q[d+NSIZE*$$] = wq$$; 69751ba79cSMatt Brown } 70751ba79cSMatt Brown} 71751ba79cSMatt Brown 72751ba79cSMatt Brownstatic void raid6_vpermxor$#_gen_syndrome(int disks, size_t bytes, void **ptrs) 73751ba79cSMatt Brown{ 74751ba79cSMatt Brown preempt_disable(); 75751ba79cSMatt Brown enable_kernel_altivec(); 76751ba79cSMatt Brown 77751ba79cSMatt Brown raid6_vpermxor$#_gen_syndrome_real(disks, bytes, ptrs); 78751ba79cSMatt Brown 79751ba79cSMatt Brown disable_kernel_altivec(); 80751ba79cSMatt Brown preempt_enable(); 81751ba79cSMatt Brown} 82751ba79cSMatt Brown 83751ba79cSMatt Brownint raid6_have_altivec_vpermxor(void); 84751ba79cSMatt Brown#if $# == 1 85751ba79cSMatt Brownint raid6_have_altivec_vpermxor(void) 86751ba79cSMatt Brown{ 87751ba79cSMatt Brown /* Check if arch has both altivec and the vpermxor instructions */ 88751ba79cSMatt Brown# ifdef __KERNEL__ 89751ba79cSMatt Brown return (cpu_has_feature(CPU_FTR_ALTIVEC_COMP) && 90751ba79cSMatt Brown cpu_has_feature(CPU_FTR_ARCH_207S)); 91751ba79cSMatt Brown# else 92751ba79cSMatt Brown return 1; 93751ba79cSMatt Brown#endif 94751ba79cSMatt Brown 95751ba79cSMatt Brown} 96751ba79cSMatt Brown#endif 97751ba79cSMatt Brown 98751ba79cSMatt Brownconst struct raid6_calls raid6_vpermxor$# = { 99751ba79cSMatt Brown raid6_vpermxor$#_gen_syndrome, 100751ba79cSMatt Brown NULL, 101751ba79cSMatt Brown raid6_have_altivec_vpermxor, 102751ba79cSMatt Brown "vpermxor$#", 103751ba79cSMatt Brown 0 104751ba79cSMatt Brown}; 105751ba79cSMatt Brown#endif 106