urcu/uatomic_arch_s390.h

   1 #ifndef _URCU_UATOMIC_ARCH_S390_H
   2 #define _URCU_UATOMIC_ARCH_S390_H
   3
   4 /*
   5  * Atomic exchange operations for the S390 architecture. Based on information
   6  * taken from the Principles of Operation Appendix A "Conditional Swapping
   7  * Instructions (CS, CDS)".
   8  *
   9  * Copyright (c) 2009 Novell, Inc.
  10  * Author: Jan Blunck <jblunck@suse.de>
  11  * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
  12  *
  13  * Permission is hereby granted, free of charge, to any person obtaining a copy
  14  * of this software and associated documentation files (the "Software"), to
  15  * deal in the Software without restriction, including without limitation the
  16  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  17  * sell copies of the Software, and to permit persons to whom the Software is
  18  * furnished to do so, subject to the following conditions:
  19  *
  20  * The above copyright notice and this permission notice shall be included in
  21  * all copies or substantial portions of the Software.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  24  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  25  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  26  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  27  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  28  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  29  * IN THE SOFTWARE.
  30  */
  31
  32 #include <urcu/compiler.h>
  33 #include <urcu/system.h>
  34
  35 #ifndef __SIZEOF_LONG__
  36 #ifdef __s390x__
  37 #define __SIZEOF_LONG__ 8
  38 #else
  39 #define __SIZEOF_LONG__ 4
  40 #endif
  41 #endif
  42
  43 #ifndef BITS_PER_LONG
  44 #define BITS_PER_LONG   (__SIZEOF_LONG__ * 8)
  45 #endif
  46
  47 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
  48 #define COMPILER_HAVE_SHORT_MEM_OPERAND
  49 #endif
  50
  51 /*
  52  * MEMOP assembler operand rules:
  53  * - op refer to MEMOP_IN operand
  54  * - MEMOP_IN can expand to more than a single operand. Use it at the end of
  55  *   operand list only.
  56  */
  57
  58 #ifdef COMPILER_HAVE_SHORT_MEM_OPERAND
  59
  60 #define MEMOP_OUT(addr) "=Q" (*(addr))
  61 #define MEMOP_IN        "Q" (*(addr))
  62 #define MEMOP_REF(op)   #op             /* op refer to MEMOP_IN operand */
  63
  64 #else /* !COMPILER_HAVE_SHORT_MEM_OPERAND */
  65
  66 #define MEMOP_OUT(addr) "=m" (*(addr))
  67 #define MEMOP_IN        "a" (addr), "m" (*(addr))
  68 #define MEMOP_REF(op)   "0(" #op ")"    /* op refer to MEMOP_IN operand */
  69
  70 #endif /* !COMPILER_HAVE_SHORT_MEM_OPERAND */
  71
  72 #define uatomic_set(addr, v)    STORE_SHARED(*(addr), (v))
  73 #define uatomic_read(addr)      LOAD_SHARED(*(addr))
  74
  75 /* xchg */
  76
  77 static inline __attribute__((always_inline))
  78 unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len)
  79 {
  80         switch (len) {
  81         case 4:
  82         {
  83                 unsigned int old_val;
  84
  85                 __asm__ __volatile__(
  86                         "0:     cs %0,%2," MEMOP_REF(%3) "\n"
  87                         "       brc 4,0b\n"
  88                         : "=&r" (old_val), MEMOP_OUT (addr)
  89                         : "r" (val), MEMOP_IN (addr)
  90                         : "memory", "cc");
  91                 return old_val;
  92         }
  93 #if (BITS_PER_LONG == 64)
  94         case 8:
  95         {
  96                 unsigned long old_val;
  97
  98                 __asm__ __volatile__(
  99                         "0:     csg %0,%2," MEMOP_REF(%3) "\n"
 100                         "       brc 4,0b\n"
 101                         : "=&r" (old_val), MEMOP_OUT (addr)
 102                         : "r" (val), MEMOP_IN (addr)
 103                         : "memory", "cc");
 104                 return old_val;
 105         }
 106 #endif
 107         default:
 108                 __asm__ __volatile__(".long     0xd00d00");
 109         }
 110
 111         return 0;
 112 }
 113
 114 #define uatomic_xchg(addr, v)                                               \
 115         (__typeof__(*(addr))) _uatomic_exchange((addr), (unsigned long)(v), \
 116                                                sizeof(*(addr)))
 117
 118 /* cmpxchg */
 119
 120 static inline __attribute__((always_inline))
 121 unsigned long _uatomic_cmpxchg(void *addr, unsigned long old,
 122                                unsigned long _new, int len)
 123 {
 124         switch (len) {
 125         case 4:
 126         {
 127                 unsigned int old_val = (unsigned int)old;
 128
 129                 __asm__ __volatile__(
 130                         "       cs %0,%2," MEMOP_REF(%3) "\n"
 131                         : "+r" (old_val), MEMOP_OUT (addr)
 132                         : "r" (_new), MEMOP_IN (addr)
 133                         : "memory", "cc");
 134                 return old_val;
 135         }
 136 #if (BITS_PER_LONG == 64)
 137         case 8:
 138         {
 139                 __asm__ __volatile__(
 140                         "       csg %0,%2," MEMOP_REF(%3) "\n"
 141                         : "+r" (old), MEMOP_OUT (addr)
 142                         : "r" (_new), MEMOP_IN (addr)
 143                         : "memory", "cc");
 144                 return old;
 145         }
 146 #endif
 147         default:
 148                 __asm__ __volatile__(".long     0xd00d00");
 149         }
 150
 151         return 0;
 152 }
 153
 154 #define uatomic_cmpxchg(addr, old, _new)                                \
 155         (__typeof__(*(addr))) _uatomic_cmpxchg((addr),                  \
 156                                                (unsigned long)(old),    \
 157                                                (unsigned long)(_new),   \
 158                                                sizeof(*(addr)))
 159
 160 /* uatomic_add_return */
 161
 162 static inline __attribute__((always_inline))
 163 unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
 164 {
 165         switch (len) {
 166         case 4:
 167         {
 168                 unsigned int old, oldt;
 169
 170                 oldt = uatomic_read((unsigned int *)addr);
 171                 do {
 172                         old = oldt;
 173                         oldt = _uatomic_cmpxchg(addr, old, old + val, 4);
 174                 } while (oldt != old);
 175
 176                 return old + val;
 177         }
 178 #if (BITS_PER_LONG == 64)
 179         case 8:
 180         {
 181                 unsigned long old, oldt;
 182
 183                 oldt = uatomic_read((unsigned long *)addr);
 184                 do {
 185                         old = oldt;
 186                         oldt = _uatomic_cmpxchg(addr, old, old + val, 8);
 187                 } while (oldt != old);
 188
 189                 return old + val;
 190         }
 191 #endif
 192         }
 193         __builtin_trap();
 194         return 0;
 195 }
 196
 197 #define uatomic_add_return(addr, v)                                     \
 198         ((__typeof__(*(addr))) _uatomic_add_return((addr),              \
 199                                                   (unsigned long)(v),   \
 200                                                   sizeof(*(addr))))
 201
 202 /* uatomic_sub_return, uatomic_add, uatomic_sub, uatomic_inc, uatomic_dec */
 203
 204 #define uatomic_sub_return(addr, v)     uatomic_add_return((addr), -(v))
 205
 206 #define uatomic_add(addr, v)            (void)uatomic_add_return((addr), (v))
 207 #define uatomic_sub(addr, v)            (void)uatomic_sub_return((addr), (v))
 208
 209 #define uatomic_inc(addr)               uatomic_add((addr), 1)
 210 #define uatomic_dec(addr)               uatomic_add((addr), -1)
 211
 212 #define compat_uatomic_cmpxchg(ptr, old, _new)  uatomic_cmpxchg(ptr, old, _new)
 213
 214 #endif /* _URCU_UATOMIC_ARCH_S390_H */