/* -*- linux-c -*- ------------------------------------------------------- * * * Copyright 2002-2004 H. Peter Anvin - All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, Inc., 53 Temple Place Ste 330, * Bostom MA 02111-1307, USA; either version 2 of the License, or * (at your option) any later version; incorporated herein by reference. * * ----------------------------------------------------------------------- */ /* * raid6altivec$#.c * * $#-way unrolled portable integer math RAID-6 instruction set * * This file is postprocessed using unroll.pl * * <benh> hpa: in process, * you can just "steal" the vec unit with enable_kernel_altivec() (but * bracked this with preempt_disable/enable or in a lock) */ #include "raid6.h" #ifdef CONFIG_ALTIVEC #include <altivec.h> #ifdef __KERNEL__ # include <asm/system.h> # include <asm/cputable.h> #endif /* * This is the C data type to use. We use a vector of * signed char so vec_cmpgt() will generate the right * instruction. */ typedef vector signed char unative_t; #define NBYTES(x) ((vector signed char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x}) #define NSIZE sizeof(unative_t) /* * The SHLBYTE() operation shifts each byte left by 1, *not* * rolling over into the next byte */ static inline __attribute_const__ unative_t SHLBYTE(unative_t v) { return vec_add(v,v); } /* * The MASK() operation returns 0xFF in any byte for which the high * bit is 1, 0x00 for any byte for which the high bit is 0. */ static inline __attribute_const__ unative_t MASK(unative_t v) { unative_t zv = NBYTES(0); /* vec_cmpgt returns a vector bool char; thus the need for the cast */ return (unative_t)vec_cmpgt(zv, v); } /* This is noinline to make damned sure that gcc doesn't move any of the Altivec code around the enable/disable code */ static void noinline raid6_altivec$#_gen_syndrome_real(int disks, size_t bytes, void **ptrs) { u8 **dptr = (u8 **)ptrs; u8 *p, *q; int d, z, z0; unative_t wd$$, wq$$, wp$$, w1$$, w2$$; unative_t x1d = NBYTES(0x1d); z0 = disks - 3; /* Highest data disk */ p = dptr[z0+1]; /* XOR parity */ q = dptr[z0+2]; /* RS syndrome */ for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; for ( z = z0-1 ; z >= 0 ; z-- ) { wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; wp$$ = vec_xor(wp$$, wd$$); w2$$ = MASK(wq$$); w1$$ = SHLBYTE(wq$$); w2$$ = vec_and(w2$$, x1d); w1$$ = vec_xor(w1$$, w2$$); wq$$ = vec_xor(w1$$, wd$$); } *(unative_t *)&p[d+NSIZE*$$] = wp$$; *(unative_t *)&q[d+NSIZE*$$] = wq$$; } } static void raid6_altivec$#_gen_syndrome(int disks, size_t bytes, void **ptrs) { preempt_disable(); enable_kernel_altivec(); raid6_altivec$#_gen_syndrome_real(disks, bytes, ptrs); preempt_enable(); } int raid6_have_altivec(void); #if $# == 1 int raid6_have_altivec(void) { /* This assumes either all CPUs have Altivec or none does */ # ifdef __KERNEL__ return cpu_has_feature(CPU_FTR_ALTIVEC); # else return 1; # endif } #endif const struct raid6_calls raid6_altivec$# = { raid6_altivec$#_gen_syndrome, raid6_have_altivec, "altivecx$#", 0 }; #endif /* CONFIG_ALTIVEC */