glibc/sysdeps/powerpc/nptl/pthread_spin_lock.c

44 lines
1.3 KiB
C

/* Copyright (C) 2003-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include "pthreadP.h"
int
pthread_spin_lock (pthread_spinlock_t *lock)
{
unsigned int __tmp;
asm volatile (
"1: lwarx %0,0,%1" MUTEX_HINT_ACQ "\n"
" cmpwi 0,%0,0\n"
" bne- 2f\n"
" stwcx. %2,0,%1\n"
" bne- 2f\n"
__ARCH_ACQ_INSTR "\n"
" .subsection 1\n"
"2: lwzx %0,0,%1\n"
" cmpwi 0,%0,0\n"
" bne 2b\n"
" b 1b\n"
" .previous"
: "=&r" (__tmp)
: "r" (lock), "r" (1)
: "cr0", "memory");
return 0;
}