sysdeps/s390/s390-64/atomicity.h

   1 /* Low-level functions for atomic operations.  64 bit S/390 version.
   2    Copyright (C) 2001 Free Software Foundation, Inc.
   3    Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _ATOMICITY_H
  22 #define _ATOMICITY_H    1
  23
  24 #include <inttypes.h>
  25
  26 static inline int
  27 __attribute__ ((unused))
  28 exchange_and_add (volatile uint32_t *mem, int val)
  29 {
  30   int result;
  31   __asm__ __volatile__(
  32         "       L     %0,%2\n"
  33         "       LA    2,%1\n"
  34         "0:     LR    0,%0\n"
  35         "       AR    0,%3\n"
  36         "       CS    %0,0,0(2)\n"
  37         "       JL    0b"
  38         : "=&d" (result), "=m" (*mem)
  39         : "1" (*mem), "d" (val) : "0", "1", "2" );
  40   return result;
  41 }
  42
  43 static inline void
  44 __attribute__ ((unused))
  45 atomic_add (volatile uint32_t *mem, int val)
  46 {
  47   __asm__ __volatile__(
  48         "       LA    2,%0\n"
  49         "0:     L     0,%1\n"
  50         "       LR    1,0\n"
  51         "       AR    1,%2\n"
  52         "       CS    0,1,0(2)\n"
  53         "       JL    0b"
  54         : "=m" (*mem) : "0" (*mem), "d" (val) : "0", "1", "2" );
  55 }
  56
  57 static inline int
  58 __attribute__ ((unused))
  59 compare_and_swap (volatile long int *p, long int oldval, long int newval)
  60 {
  61   int retval;
  62
  63   __asm__ __volatile__(
  64         "  la   1,%1\n"
  65         "  lgr  0,%2\n"
  66         "  csg  0,%3,0(1)\n"
  67         "  ipm  %0\n"
  68         "  srl  %0,28\n"
  69         "0:"
  70         : "=&r" (retval), "+m" (*p)
  71         : "d" (oldval) , "d" (newval)
  72         : "memory", "0", "1", "cc");
  73   return !retval;
  74 }
  75
  76 #endif /* atomicity.h */