linuxthreads/sysdeps/hppa/pt-machine.h

   1 /* Machine-dependent pthreads configuration and inline functions.
   2    hppa version.
   3    Copyright (C) 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 not,
  19    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef _PT_MACHINE_H
  23 #define _PT_MACHINE_H   1
  24
  25 #include <bits/initspin.h>
  26
  27 #ifndef PT_EI
  28 # define PT_EI extern inline __attribute__ ((always_inline))
  29 #endif
  30
  31 extern long int testandset (int *spinlock);
  32 extern int __compare_and_swap (long int *p, long int oldval, long int newval);
  33
  34 /* Get some notion of the current stack.  Need not be exactly the top
  35    of the stack, just something somewhere in the current frame.  */
  36 #define CURRENT_STACK_FRAME  stack_pointer
  37 register char * stack_pointer __asm__ ("%r30");
  38
  39
  40 /* The hppa only has one atomic read and modify memory operation,
  41    load and clear, so hppa spinlocks must use zero to signify that
  42    someone is holding the lock.  */
  43
  44 #define xstr(s) str(s)
  45 #define str(s) #s
  46 /* Spinlock implementation; required.  */
  47 PT_EI long int
  48 testandset (int *spinlock)
  49 {
  50   int ret;
  51
  52   __asm__ __volatile__(
  53        "ldcw 0(%2),%0"
  54        : "=r"(ret), "=m"(*spinlock)
  55        : "r"(spinlock));
  56
  57   return ret == 0;
  58 }
  59 #undef str
  60 #undef xstr
  61
  62 #endif /* pt-machine.h */