libpthread/nptl/sysdeps/pthread_spin_lock.c

   1 /* Copyright (C) 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include "pthreadP.h"
  20
  21 int
  22 pthread_spin_lock (pthread_spinlock_t *lock)
  23 {
  24   __asm__ __volatile__
  25     ("1: ldstub [%0], %%g2\n"
  26      "   orcc   %%g2, 0x0, %%g0\n"
  27      "   bne,a  2f\n"
  28      "   ldub   [%0], %%g2\n"
  29      ".subsection 2\n"
  30      "2: orcc   %%g2, 0x0, %%g0\n"
  31      "   bne,a  2b\n"
  32      "   ldub   [%0], %%g2\n"
  33      "   b,a    1b\n"
  34      ".previous"
  35      : /* no outputs */
  36      : "r" (lock)
  37      : "g2", "memory", "cc");
  38   return 0;
  39 }