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