linuxthreads/sysdeps/cris/pt-machine.h

   1 /* Machine-dependent pthreads configuration and inline functions.
   2    CRIS version.
   3    Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
   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 License as
   8    published by the Free Software Foundation; either version 2.1 of the
   9    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; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #ifndef _PT_MACHINE_H
  22 #define _PT_MACHINE_H   1
  23
  24 #ifndef PT_EI
  25 # define PT_EI extern inline __attribute__ ((always_inline))
  26 #endif
  27
  28 extern long int testandset (int *spinlock);
  29 extern int __compare_and_swap (long int *p, long int oldval, long int newval);
  30
  31 PT_EI long int
  32 testandset (int *spinlock)
  33 {
  34   register unsigned long int ret;
  35
  36   /* Note the use of a dummy output of *spinlock to expose the write.  The
  37      memory barrier is to stop *other* writes being moved past this code.  */
  38   __asm__ __volatile__("clearf\n"
  39                        "0:\n\t"
  40                        "movu.b [%2],%0\n\t"
  41                        "ax\n\t"
  42                        "move.b %3,[%2]\n\t"
  43                        "bwf 0b\n\t"
  44                        "clearf"
  45                        : "=&r" (ret), "=m" (*spinlock)
  46                        : "r" (spinlock), "r" ((int) 1)
  47                        : "memory");
  48   return ret;
  49 }
  50
  51
  52 /* Get some notion of the current stack.  Need not be exactly the top
  53    of the stack, just something somewhere in the current frame.
  54    I don't trust register variables, so let's do this the safe way.  */
  55 #define CURRENT_STACK_FRAME \
  56  ({ char *sp; __asm__ ("move.d $sp,%0" : "=rm" (sp)); sp; })
  57
  58 #endif /* pt-machine.h */