linuxthreads/sysdeps/mips/pt-machine.h

   1 /* Machine-dependent pthreads configuration and inline functions.
   2
   3    Copyright (C) 1996, 1997, 1998, 2000, 2002, 2003, 2004
   4    Free Software Foundation, Inc.
   5    This file is part of the GNU C Library.
   6    Contributed by Ralf Baechle <ralf@gnu.org>.
   7    Based on the Alpha version by Richard Henderson <rth@tamu.edu>.
   8
   9    The GNU C Library is free software; you can redistribute it and/or
  10    modify it under the terms of the GNU Lesser General Public License as
  11    published by the Free Software Foundation; either version 2.1 of the
  12    License, or (at your option) any later version.
  13
  14    The GNU C Library is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17    Lesser General Public License for more details.
  18
  19    You should have received a copy of the GNU Lesser General Public
  20    License along with the GNU C Library; see the file COPYING.LIB.  If
  21    not, write to the Free Software Foundation, Inc.,
  22    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  23
  24 #ifndef _PT_MACHINE_H
  25 #define _PT_MACHINE_H   1
  26
  27 #include <sgidefs.h>
  28 #include <sys/tas.h>
  29
  30 #ifndef PT_EI
  31 # define PT_EI extern inline __attribute__ ((always_inline))
  32 #endif
  33
  34 extern long int testandset (int *spinlock);
  35 extern int __compare_and_swap (long int *p, long int oldval, long int newval);
  36
  37
  38 /* Spinlock implementation; required.  */
  39
  40 PT_EI long int
  41 testandset (int *spinlock)
  42 {
  43   return _test_and_set (spinlock, 1);
  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__ ("$29");
  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   long int ret, temp;
  60
  61   __asm__ __volatile__
  62     ("/* Inline compare & swap */\n"
  63      "1:\n\t"
  64      ".set      push\n\t"
  65 #if _MIPS_SIM == _ABIO32
  66      ".set      mips2\n\t"
  67 #endif
  68 #if _MIPS_SIM == _ABI64
  69      "lld       %1,%5\n\t"
  70 #else
  71      "ll        %1,%5\n\t"
  72 #endif
  73      "move      %0,$0\n\t"
  74      "bne       %1,%3,2f\n\t"
  75      "move      %0,%4\n\t"
  76 #if _MIPS_SIM == _ABI64
  77      "scd       %0,%2\n\t"
  78 #else
  79      "sc        %0,%2\n\t"
  80 #endif
  81      ".set      pop\n\t"
  82      "beqz      %0,1b\n"
  83      "2:\n\t"
  84      "/* End compare & swap */"
  85      : "=&r" (ret), "=&r" (temp), "=m" (*p)
  86      : "r" (oldval), "r" (newval), "m" (*p)
  87      : "memory");
  88
  89   return ret;
  90 }
  91
  92 #endif /* pt-machine.h */