nptl/sysdeps/sh/pthread_spin_lock.c

   1 /* Copyright (C) 2003-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include "pthreadP.h"
  19
  20 int
  21 pthread_spin_lock (lock)
  22      pthread_spinlock_t *lock;
  23 {
  24   unsigned int val;
  25
  26   do
  27     asm volatile ("tas.b @%1; movt %0"
  28                   : "=&r" (val)
  29                   : "r" (lock)
  30                   : "memory");
  31   while (val == 0);
  32
  33   return 0;
  34 }