sysdeps/unix/sysv/linux/mips/sys/tas.h

   1 /* Copyright (C) 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Maciej W. Rozycki <macro@ds2.pg.gda.pl>, 2000.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #ifndef _SYS_TAS_H
  21 #define _SYS_TAS_H 1
  22
  23 #include <features.h>
  24 #include <sgidefs.h>
  25 #include <sys/sysmips.h>
  26
  27 __BEGIN_DECLS
  28
  29 extern int _test_and_set (int *p, int v) __THROW;
  30
  31 #ifdef __USE_EXTERN_INLINES
  32
  33 # ifndef _EXTERN_INLINE
  34 #  define _EXTERN_INLINE extern __inline
  35 # endif
  36
  37 # if (_MIPS_ISA >= _MIPS_ISA_MIPS2)
  38
  39 _EXTERN_INLINE int
  40 _test_and_set (int *p, int v) __THROW
  41 {
  42   int r, t;
  43
  44   __asm__ __volatile__
  45     ("1:\n\t"
  46      "ll        %0,%3\n\t"
  47      ".set      push\n\t"
  48      ".set      noreorder\n\t"
  49      "beq       %0,%4,2f\n\t"
  50      " move     %1,%4\n\t"
  51      ".set      pop\n\t"
  52      "sc        %1,%2\n\t"
  53      "beqz      %1,1b\n"
  54      "2:\n"
  55      : "=&r" (r), "=&r" (t), "=m" (*p)
  56      : "m" (*p), "r" (v)
  57      : "memory");
  58
  59   return r;
  60 }
  61
  62 # else /* !(_MIPS_ISA >= _MIPS_ISA_MIPS2) */
  63
  64 _EXTERN_INLINE int
  65 _test_and_set (int *p, int v) __THROW
  66 {
  67   return sysmips (MIPS_ATOMIC_SET, (int) p, v, 0);
  68 }
  69
  70 # endif /* !(_MIPS_ISA >= _MIPS_ISA_MIPS2) */
  71
  72 #endif /* __USE_EXTERN_INLINES */
  73
  74 __END_DECLS
  75
  76 #endif /* sys/tas.h */