78 lines
2 KiB
C
78 lines
2 KiB
C
/* Machine-specific definition for spin locks. PowerPC version.
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Copyright (C) 1994-2012 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _MACHINE_LOCK_H
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#define _MACHINE_LOCK_H
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/* The type of a spin lock variable. */
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typedef volatile long int __spin_lock_t;
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/* Value to initialize `__spin_lock_t' variables to. */
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#define __SPIN_LOCK_INITIALIZER 0L
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#ifndef _EXTERN_INLINE
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#define _EXTERN_INLINE __extern_inline
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#endif
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/* Unlock LOCK. */
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_EXTERN_INLINE void
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__spin_unlock (__spin_lock_t *__lock)
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{
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long int __locked;
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__asm__ __volatile__ ("\
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0: lwarx %0,0,%1\n\
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stwcx. %2,0,%1\n\
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bne- 0b\n\
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" : "=&r" (__locked) : "r" (__lock), "r" (0) : "cr0");
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}
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/* Try to lock LOCK; return nonzero if we locked it, zero if another has. */
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_EXTERN_INLINE int
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__spin_try_lock (register __spin_lock_t *__lock)
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{
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long int __rtn;
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__asm__ __volatile__ ("\
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0: lwarx %0,0,%1\n\
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stwcx. %2,0,%1\n\
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bne- 0b\n\
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" : "=&r" (__rtn) : "r" (__lock), "r" (1) : "cr0");
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return !__rtn;
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}
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/* Return nonzero if LOCK is locked. */
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_EXTERN_INLINE int
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__spin_lock_locked (__spin_lock_t *__lock)
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{
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long int __rtn;
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__asm__ __volatile__ ("\
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0: lwarx %0,0,%1\n\
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stwcx. %0,0,%1\n\
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bne- 0b\n\
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" : "=&r" (__rtn) : "r" (__lock) : "cr0");
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return __rtn;
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}
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#endif /* machine-lock.h */
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