arch/s390/lib/xor.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Optimized xor_block operation for RAID4/5
   4  *
   5  * Copyright IBM Corp. 2016
   6  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/export.h>
  11 #include <linux/raid/xor.h>
  12
  13 static void xor_xc_2(unsigned long bytes, unsigned long *p1, unsigned long *p2)
  14 {
  15         asm volatile(
  16                 "       larl    1,2f\n"
  17                 "       aghi    %0,-1\n"
  18                 "       jm      3f\n"
  19                 "       srlg    0,%0,8\n"
  20                 "       ltgr    0,0\n"
  21                 "       jz      1f\n"
  22                 "0:     xc      0(256,%1),0(%2)\n"
  23                 "       la      %1,256(%1)\n"
  24                 "       la      %2,256(%2)\n"
  25                 "       brctg   0,0b\n"
  26                 "1:     ex      %0,0(1)\n"
  27                 "       j       3f\n"
  28                 "2:     xc      0(1,%1),0(%2)\n"
  29                 "3:\n"
  30                 : : "d" (bytes), "a" (p1), "a" (p2)
  31                 : "0", "1", "cc", "memory");
  32 }
  33
  34 static void xor_xc_3(unsigned long bytes, unsigned long *p1, unsigned long *p2,
  35                      unsigned long *p3)
  36 {
  37         asm volatile(
  38                 "       larl    1,2f\n"
  39                 "       aghi    %0,-1\n"
  40                 "       jm      3f\n"
  41                 "       srlg    0,%0,8\n"
  42                 "       ltgr    0,0\n"
  43                 "       jz      1f\n"
  44                 "0:     xc      0(256,%1),0(%2)\n"
  45                 "       xc      0(256,%1),0(%3)\n"
  46                 "       la      %1,256(%1)\n"
  47                 "       la      %2,256(%2)\n"
  48                 "       la      %3,256(%3)\n"
  49                 "       brctg   0,0b\n"
  50                 "1:     ex      %0,0(1)\n"
  51                 "       ex      %0,6(1)\n"
  52                 "       j       3f\n"
  53                 "2:     xc      0(1,%1),0(%2)\n"
  54                 "       xc      0(1,%1),0(%3)\n"
  55                 "3:\n"
  56                 : "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3)
  57                 : : "0", "1", "cc", "memory");
  58 }
  59
  60 static void xor_xc_4(unsigned long bytes, unsigned long *p1, unsigned long *p2,
  61                      unsigned long *p3, unsigned long *p4)
  62 {
  63         asm volatile(
  64                 "       larl    1,2f\n"
  65                 "       aghi    %0,-1\n"
  66                 "       jm      3f\n"
  67                 "       srlg    0,%0,8\n"
  68                 "       ltgr    0,0\n"
  69                 "       jz      1f\n"
  70                 "0:     xc      0(256,%1),0(%2)\n"
  71                 "       xc      0(256,%1),0(%3)\n"
  72                 "       xc      0(256,%1),0(%4)\n"
  73                 "       la      %1,256(%1)\n"
  74                 "       la      %2,256(%2)\n"
  75                 "       la      %3,256(%3)\n"
  76                 "       la      %4,256(%4)\n"
  77                 "       brctg   0,0b\n"
  78                 "1:     ex      %0,0(1)\n"
  79                 "       ex      %0,6(1)\n"
  80                 "       ex      %0,12(1)\n"
  81                 "       j       3f\n"
  82                 "2:     xc      0(1,%1),0(%2)\n"
  83                 "       xc      0(1,%1),0(%3)\n"
  84                 "       xc      0(1,%1),0(%4)\n"
  85                 "3:\n"
  86                 : "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3), "+a" (p4)
  87                 : : "0", "1", "cc", "memory");
  88 }
  89
  90 static void xor_xc_5(unsigned long bytes, unsigned long *p1, unsigned long *p2,
  91                      unsigned long *p3, unsigned long *p4, unsigned long *p5)
  92 {
  93         /* Get around a gcc oddity */
  94         register unsigned long *reg7 asm ("7") = p5;
  95
  96         asm volatile(
  97                 "       larl    1,2f\n"
  98                 "       aghi    %0,-1\n"
  99                 "       jm      3f\n"
 100                 "       srlg    0,%0,8\n"
 101                 "       ltgr    0,0\n"
 102                 "       jz      1f\n"
 103                 "0:     xc      0(256,%1),0(%2)\n"
 104                 "       xc      0(256,%1),0(%3)\n"
 105                 "       xc      0(256,%1),0(%4)\n"
 106                 "       xc      0(256,%1),0(%5)\n"
 107                 "       la      %1,256(%1)\n"
 108                 "       la      %2,256(%2)\n"
 109                 "       la      %3,256(%3)\n"
 110                 "       la      %4,256(%4)\n"
 111                 "       la      %5,256(%5)\n"
 112                 "       brctg   0,0b\n"
 113                 "1:     ex      %0,0(1)\n"
 114                 "       ex      %0,6(1)\n"
 115                 "       ex      %0,12(1)\n"
 116                 "       ex      %0,18(1)\n"
 117                 "       j       3f\n"
 118                 "2:     xc      0(1,%1),0(%2)\n"
 119                 "       xc      0(1,%1),0(%3)\n"
 120                 "       xc      0(1,%1),0(%4)\n"
 121                 "       xc      0(1,%1),0(%5)\n"
 122                 "3:\n"
 123                 : "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3), "+a" (p4),
 124                   "+a" (reg7)
 125                 : : "0", "1", "cc", "memory");
 126 }
 127
 128 struct xor_block_template xor_block_xc = {
 129         .name = "xc",
 130         .do_2 = xor_xc_2,
 131         .do_3 = xor_xc_3,
 132         .do_4 = xor_xc_4,
 133         .do_5 = xor_xc_5,
 134 };
 135 EXPORT_SYMBOL(xor_block_xc);