93 lines
2.5 KiB
C
93 lines
2.5 KiB
C
/* Machine-specific definition for spin locks. MIPS version.
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Copyright (C) 1996, 1997 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, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#ifndef _MACHINE_LOCK_H
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#define _MACHINE_LOCK_H
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/* To get the TAS pseudo-instruction. */
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#include <mach/mips/mips_instruction.h>
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/* The type of a spin lock variable. */
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typedef __volatile int __spin_lock_t;
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/* Value to initialize `__spin_lock_t' variables to. */
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#define __SPIN_LOCK_INITIALIZER 0
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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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*__lock = 0;
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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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#if (__mips >= 2)
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int __rtn;
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__asm__ __volatile (".set noreorder");
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#if (__mips64)
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__asm__ __volatile ("lld %0,0(%1)" : "=r" (__rtn) : "r" (__lock));
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#else
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__asm__ __volatile ("ll %0,0(%1)" : "=r" (__rtn) : "r" (__lock));
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#endif
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if (__rtn)
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return 0;
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__asm__ __volatile ("move %0,%1" : "=r" (__rtn) : "r" (__lock));
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#if (__mips64)
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__asm__ __volatile ("scd %0,0(%1)" : "=r" (__rtn) : "r" (__lock));
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#else
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__asm__ __volatile ("sc %0,0(%1)" : "=r" (__rtn) : "r" (__lock));
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#endif
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__asm__ __volatile (".set reorder");
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return __rtn;
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#else
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register int __rtn __asm__ ("a0");
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/* Use the Mach microkernel's emulated TAS pseudo-instruction. */
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__asm__ __volatile (".set noreorder");
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__asm__ __volatile (".word %1" : "=r" (__rtn) : "i" (op_tas), "0" (__lock));
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__asm__ __volatile ("nop");
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__asm__ __volatile (".set reorder");
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return __rtn ^ (int) __lock;
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#endif
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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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return *__lock != 0;
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}
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#endif /* machine-lock.h */
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