lib/raid6/s390vx.uc

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * raid6_vx$#.c
   4  *
   5  * $#-way unrolled RAID6 gen/xor functions for s390
   6  * based on the vector facility
   7  *
   8  * Copyright IBM Corp. 2016
   9  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  10  *
  11  * This file is postprocessed using unroll.awk.
  12  */
  13
  14 #include <linux/raid/pq.h>
  15 #include <asm/fpu/api.h>
  16
  17 asm(".include \"asm/vx-insn.h\"\n");
  18
  19 #define NSIZE 16
  20
  21 static inline void LOAD_CONST(void)
  22 {
  23         asm volatile("VREPIB %v24,7");
  24         asm volatile("VREPIB %v25,0x1d");
  25 }
  26
  27 /*
  28  * The SHLBYTE() operation shifts each of the 16 bytes in
  29  * vector register y left by 1 bit and stores the result in
  30  * vector register x.
  31  */
  32 static inline void SHLBYTE(int x, int y)
  33 {
  34         asm volatile ("VAB %0,%1,%1" : : "i" (x), "i" (y));
  35 }
  36
  37 /*
  38  * For each of the 16 bytes in the vector register y the MASK()
  39  * operation returns 0xFF if the high bit of the byte is 1,
  40  * or 0x00 if the high bit is 0. The result is stored in vector
  41  * register x.
  42  */
  43 static inline void MASK(int x, int y)
  44 {
  45         asm volatile ("VESRAVB  %0,%1,24" : : "i" (x), "i" (y));
  46 }
  47
  48 static inline void AND(int x, int y, int z)
  49 {
  50         asm volatile ("VN %0,%1,%2" : : "i" (x), "i" (y), "i" (z));
  51 }
  52
  53 static inline void XOR(int x, int y, int z)
  54 {
  55         asm volatile ("VX %0,%1,%2" : : "i" (x), "i" (y), "i" (z));
  56 }
  57
  58 static inline void LOAD_DATA(int x, u8 *ptr)
  59 {
  60         typedef struct { u8 _[16 * $#]; } addrtype;
  61         register addrtype *__ptr asm("1") = (addrtype *) ptr;
  62
  63         asm volatile ("VLM %2,%3,0,%1"
  64                       : : "m" (*__ptr), "a" (__ptr), "i" (x),
  65                           "i" (x + $# - 1));
  66 }
  67
  68 static inline void STORE_DATA(int x, u8 *ptr)
  69 {
  70         typedef struct { u8 _[16 * $#]; } addrtype;
  71         register addrtype *__ptr asm("1") = (addrtype *) ptr;
  72
  73         asm volatile ("VSTM %2,%3,0,1"
  74                       : "=m" (*__ptr) : "a" (__ptr), "i" (x),
  75                         "i" (x + $# - 1));
  76 }
  77
  78 static inline void COPY_VEC(int x, int y)
  79 {
  80         asm volatile ("VLR %0,%1" : : "i" (x), "i" (y));
  81 }
  82
  83 static void raid6_s390vx$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
  84 {
  85         struct kernel_fpu vxstate;
  86         u8 **dptr, *p, *q;
  87         int d, z, z0;
  88
  89         kernel_fpu_begin(&vxstate, KERNEL_VXR);
  90         LOAD_CONST();
  91
  92         dptr = (u8 **) ptrs;
  93         z0 = disks - 3;         /* Highest data disk */
  94         p = dptr[z0 + 1];       /* XOR parity */
  95         q = dptr[z0 + 2];       /* RS syndrome */
  96
  97         for (d = 0; d < bytes; d += $#*NSIZE) {
  98                 LOAD_DATA(0,&dptr[z0][d]);
  99                 COPY_VEC(8+$$,0+$$);
 100                 for (z = z0 - 1; z >= 0; z--) {
 101                         MASK(16+$$,8+$$);
 102                         AND(16+$$,16+$$,25);
 103                         SHLBYTE(8+$$,8+$$);
 104                         XOR(8+$$,8+$$,16+$$);
 105                         LOAD_DATA(16,&dptr[z][d]);
 106                         XOR(0+$$,0+$$,16+$$);
 107                         XOR(8+$$,8+$$,16+$$);
 108                 }
 109                 STORE_DATA(0,&p[d]);
 110                 STORE_DATA(8,&q[d]);
 111         }
 112         kernel_fpu_end(&vxstate, KERNEL_VXR);
 113 }
 114
 115 static void raid6_s390vx$#_xor_syndrome(int disks, int start, int stop,
 116                                         size_t bytes, void **ptrs)
 117 {
 118         struct kernel_fpu vxstate;
 119         u8 **dptr, *p, *q;
 120         int d, z, z0;
 121
 122         dptr = (u8 **) ptrs;
 123         z0 = stop;              /* P/Q right side optimization */
 124         p = dptr[disks - 2];    /* XOR parity */
 125         q = dptr[disks - 1];    /* RS syndrome */
 126
 127         kernel_fpu_begin(&vxstate, KERNEL_VXR);
 128         LOAD_CONST();
 129
 130         for (d = 0; d < bytes; d += $#*NSIZE) {
 131                 /* P/Q data pages */
 132                 LOAD_DATA(0,&dptr[z0][d]);
 133                 COPY_VEC(8+$$,0+$$);
 134                 for (z = z0 - 1; z >= start; z--) {
 135                         MASK(16+$$,8+$$);
 136                         AND(16+$$,16+$$,25);
 137                         SHLBYTE(8+$$,8+$$);
 138                         XOR(8+$$,8+$$,16+$$);
 139                         LOAD_DATA(16,&dptr[z][d]);
 140                         XOR(0+$$,0+$$,16+$$);
 141                         XOR(8+$$,8+$$,16+$$);
 142                 }
 143                 /* P/Q left side optimization */
 144                 for (z = start - 1; z >= 0; z--) {
 145                         MASK(16+$$,8+$$);
 146                         AND(16+$$,16+$$,25);
 147                         SHLBYTE(8+$$,8+$$);
 148                         XOR(8+$$,8+$$,16+$$);
 149                 }
 150                 LOAD_DATA(16,&p[d]);
 151                 XOR(16+$$,16+$$,0+$$);
 152                 STORE_DATA(16,&p[d]);
 153                 LOAD_DATA(16,&q[d]);
 154                 XOR(16+$$,16+$$,8+$$);
 155                 STORE_DATA(16,&q[d]);
 156         }
 157         kernel_fpu_end(&vxstate, KERNEL_VXR);
 158 }
 159
 160 static int raid6_s390vx$#_valid(void)
 161 {
 162         return MACHINE_HAS_VX;
 163 }
 164
 165 const struct raid6_calls raid6_s390vx$# = {
 166         raid6_s390vx$#_gen_syndrome,
 167         raid6_s390vx$#_xor_syndrome,
 168         raid6_s390vx$#_valid,
 169         "vx128x$#",
 170         1
 171 };