linux/lib/raid6/mmx.c
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   1/* -*- linux-c -*- ------------------------------------------------------- *
   2 *
   3 *   Copyright 2002 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 * raid6/mmx.c
  15 *
  16 * MMX implementation of RAID-6 syndrome functions
  17 */
  18
  19#if defined(__i386__) && !defined(__arch_um__)
  20
  21#include <linux/raid/pq.h>
  22#include "x86.h"
  23
  24/* Shared with raid6/sse1.c */
  25const struct raid6_mmx_constants {
  26        u64 x1d;
  27} raid6_mmx_constants = {
  28        0x1d1d1d1d1d1d1d1dULL,
  29};
  30
  31static int raid6_have_mmx(void)
  32{
  33        /* Not really "boot_cpu" but "all_cpus" */
  34        return boot_cpu_has(X86_FEATURE_MMX);
  35}
  36
  37/*
  38 * Plain MMX implementation
  39 */
  40static void raid6_mmx1_gen_syndrome(int disks, size_t bytes, void **ptrs)
  41{
  42        u8 **dptr = (u8 **)ptrs;
  43        u8 *p, *q;
  44        int d, z, z0;
  45
  46        z0 = disks - 3;         /* Highest data disk */
  47        p = dptr[z0+1];         /* XOR parity */
  48        q = dptr[z0+2];         /* RS syndrome */
  49
  50        kernel_fpu_begin();
  51
  52        asm volatile("movq %0,%%mm0" : : "m" (raid6_mmx_constants.x1d));
  53        asm volatile("pxor %mm5,%mm5"); /* Zero temp */
  54
  55        for ( d = 0 ; d < bytes ; d += 8 ) {
  56                asm volatile("movq %0,%%mm2" : : "m" (dptr[z0][d])); /* P[0] */
  57                asm volatile("movq %mm2,%mm4"); /* Q[0] */
  58                for ( z = z0-1 ; z >= 0 ; z-- ) {
  59                        asm volatile("movq %0,%%mm6" : : "m" (dptr[z][d]));
  60                        asm volatile("pcmpgtb %mm4,%mm5");
  61                        asm volatile("paddb %mm4,%mm4");
  62                        asm volatile("pand %mm0,%mm5");
  63                        asm volatile("pxor %mm5,%mm4");
  64                        asm volatile("pxor %mm5,%mm5");
  65                        asm volatile("pxor %mm6,%mm2");
  66                        asm volatile("pxor %mm6,%mm4");
  67                }
  68                asm volatile("movq %%mm2,%0" : "=m" (p[d]));
  69                asm volatile("pxor %mm2,%mm2");
  70                asm volatile("movq %%mm4,%0" : "=m" (q[d]));
  71                asm volatile("pxor %mm4,%mm4");
  72        }
  73
  74        kernel_fpu_end();
  75}
  76
  77const struct raid6_calls raid6_mmxx1 = {
  78        raid6_mmx1_gen_syndrome,
  79        raid6_have_mmx,
  80        "mmxx1",
  81        0
  82};
  83
  84/*
  85 * Unrolled-by-2 MMX implementation
  86 */
  87static void raid6_mmx2_gen_syndrome(int disks, size_t bytes, void **ptrs)
  88{
  89        u8 **dptr = (u8 **)ptrs;
  90        u8 *p, *q;
  91        int d, z, z0;
  92
  93        z0 = disks - 3;         /* Highest data disk */
  94        p = dptr[z0+1];         /* XOR parity */
  95        q = dptr[z0+2];         /* RS syndrome */
  96
  97        kernel_fpu_begin();
  98
  99        asm volatile("movq %0,%%mm0" : : "m" (raid6_mmx_constants.x1d));
 100        asm volatile("pxor %mm5,%mm5"); /* Zero temp */
 101        asm volatile("pxor %mm7,%mm7"); /* Zero temp */
 102
 103        for ( d = 0 ; d < bytes ; d += 16 ) {
 104                asm volatile("movq %0,%%mm2" : : "m" (dptr[z0][d])); /* P[0] */
 105                asm volatile("movq %0,%%mm3" : : "m" (dptr[z0][d+8]));
 106                asm volatile("movq %mm2,%mm4"); /* Q[0] */
 107                asm volatile("movq %mm3,%mm6"); /* Q[1] */
 108                for ( z = z0-1 ; z >= 0 ; z-- ) {
 109                        asm volatile("pcmpgtb %mm4,%mm5");
 110                        asm volatile("pcmpgtb %mm6,%mm7");
 111                        asm volatile("paddb %mm4,%mm4");
 112                        asm volatile("paddb %mm6,%mm6");
 113                        asm volatile("pand %mm0,%mm5");
 114                        asm volatile("pand %mm0,%mm7");
 115                        asm volatile("pxor %mm5,%mm4");
 116                        asm volatile("pxor %mm7,%mm6");
 117                        asm volatile("movq %0,%%mm5" : : "m" (dptr[z][d]));
 118                        asm volatile("movq %0,%%mm7" : : "m" (dptr[z][d+8]));
 119                        asm volatile("pxor %mm5,%mm2");
 120                        asm volatile("pxor %mm7,%mm3");
 121                        asm volatile("pxor %mm5,%mm4");
 122                        asm volatile("pxor %mm7,%mm6");
 123                        asm volatile("pxor %mm5,%mm5");
 124                        asm volatile("pxor %mm7,%mm7");
 125                }
 126                asm volatile("movq %%mm2,%0" : "=m" (p[d]));
 127                asm volatile("movq %%mm3,%0" : "=m" (p[d+8]));
 128                asm volatile("movq %%mm4,%0" : "=m" (q[d]));
 129                asm volatile("movq %%mm6,%0" : "=m" (q[d+8]));
 130        }
 131
 132        kernel_fpu_end();
 133}
 134
 135const struct raid6_calls raid6_mmxx2 = {
 136        raid6_mmx2_gen_syndrome,
 137        raid6_have_mmx,
 138        "mmxx2",
 139        0
 140};
 141
 142#endif
 143
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