urcu/arch_uatomic_s390.h

   1 #ifndef _URCU_ARCH_ATOMIC_S390_H
   2 #define _URCU_ARCH_ATOMIC_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  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a copy
  13  * of this software and associated documentation files (the "Software"), to
  14  * deal in the Software without restriction, including without limitation the
  15  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  16  * sell copies of the Software, and to permit persons to whom the Software is
  17  * furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included in
  20  * all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  25  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  27  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  28  * IN THE SOFTWARE.
  29  */
  30
  31 #ifndef __SIZEOF_LONG__
  32 #ifdef __s390x__
  33 #define __SIZEOF_LONG__ 8
  34 #else
  35 #define __SIZEOF_LONG__ 4
  36 #endif
  37 #endif
  38
  39 #ifndef BITS_PER_LONG
  40 #define BITS_PER_LONG   (__SIZEOF_LONG__ * 8)
  41 #endif
  42
  43 static inline __attribute__((always_inline))
  44 unsigned int uatomic_exchange_32(volatile unsigned int *addr, unsigned int val)
  45 {
  46         unsigned int result;
  47
  48         __asm__ __volatile__(
  49                 "0:     cs %0,%2,%1\n"
  50                 "       brc 4,0b\n"
  51                 : "=&r"(result), "=m" (*addr)
  52                 : "r"(val), "m" (*addr)
  53                 : "memory", "cc");
  54
  55         return result;
  56 }
  57
  58 #if (BITS_PER_LONG == 64)
  59
  60 static inline __attribute__((always_inline))
  61 unsigned long uatomic_exchange_64(volatile unsigned long *addr,
  62                                  unsigned long val)
  63 {
  64         unsigned long result;
  65
  66         __asm__ __volatile__(
  67                 "0:     csg %0,%2,%1\n"
  68                 "       brc 4,0b\n"
  69                 : "=&r"(result), "=m" (*addr)
  70                 : "r"(val), "m" (*addr)
  71                 : "memory", "cc");
  72
  73         return result;
  74 }
  75
  76 #endif
  77
  78 static inline __attribute__((always_inline))
  79 unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len)
  80 {
  81         switch (len) {
  82         case 4:
  83                 return uatomic_exchange_32(addr, val);
  84 #if (BITS_PER_LONG == 64)
  85         case 8:
  86                 return uatomic_exchange_64(addr, val);
  87 #endif
  88         default:
  89                 __asm__ __volatile__(".long     0xd00d00");
  90         }
  91
  92         return 0;
  93 }
  94
  95 #define uatomic_xchg(addr, v)                                           \
  96         (__typeof__(*(addr))) _uatomic_exchange((addr), (unsigned long)(v), \
  97                                                sizeof(*(addr)))
  98
  99 #endif /* _URCU_ARCH_ATOMIC_S390_H */