linuxthreads/sysdeps/m68k/pt-machine.h

   1 /* Machine-dependent pthreads configuration and inline functions.
   2    m68k version.
   3    Copyright (C) 1996, 1998, 2000, 2002, 2003 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5    Contributed by Richard Henderson <rth@tamu.edu>.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public License as
   9    published by the Free Software Foundation; either version 2.1 of the
  10    License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; see the file COPYING.LIB.  If
  19    not, write to the Free Software Foundation, Inc.,
  20    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef _PT_MACHINE_H
  23 #define _PT_MACHINE_H   1
  24
  25 #ifndef PT_EI
  26 # define PT_EI extern inline __attribute__ ((always_inline))
  27 #endif
  28
  29 extern long int testandset (int *spinlock);
  30 extern int __compare_and_swap (long int *p, long int oldval, long int newval);
  31
  32 /* Spinlock implementation; required.  */
  33 PT_EI long int
  34 testandset (int *spinlock)
  35 {
  36   char ret;
  37
  38   __asm__ __volatile__("tas %1; sne %0"
  39        : "=dm"(ret), "=m"(*spinlock)
  40        : "m"(*spinlock)
  41        : "cc");
  42
  43   return ret;
  44 }
  45
  46
  47 /* Get some notion of the current stack.  Need not be exactly the top
  48    of the stack, just something somewhere in the current frame.  */
  49 #define CURRENT_STACK_FRAME  stack_pointer
  50 register char * stack_pointer __asm__ ("%sp");
  51
  52
  53 /* Compare-and-swap for semaphores. */
  54
  55 #define HAS_COMPARE_AND_SWAP
  56 PT_EI int
  57 __compare_and_swap (long int *p, long int oldval, long int newval)
  58 {
  59   char ret;
  60   long int readval;
  61
  62   __asm__ __volatile__ ("casl %2, %3, %1; seq %0"
  63                         : "=dm" (ret), "=m" (*p), "=d" (readval)
  64                         : "d" (newval), "m" (*p), "2" (oldval));
  65
  66   return ret;
  67 }
  68
  69 #endif /* pt-machine.h */