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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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C
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172#ifndef __LINUX_SPINLOCK_UP_H#define __LINUX_SPINLOCK_UP_H
#ifndef __LINUX_INSIDE_SPINLOCK_H# error "Please do not include this file directly."#endif
#include <asm/processor.h> /* for cpu_relax() */#include <asm/barrier.h>
/* * include/linux/spinlock_up.h - UP-debug version of spinlocks. * * portions Copyright 2005, Red Hat, Inc., Ingo Molnar * Released under the General Public License (GPL). * * In the debug case, 1 means unlocked, 0 means locked. (the values * are inverted, to catch initialization bugs) * * No atomicity anywhere, we are on UP. However, we still need * the compiler barriers, because we do not want the compiler to * move potentially faulting instructions (notably user accesses) * into the locked sequence, resulting in non-atomic execution. */
#ifdef CONFIG_DEBUG_SPINLOCK#define arch_spin_is_locked(x) ((x)->slock == 0)
static inline void arch_spin_lock(arch_spinlock_t *lock){ lock->slock = 0; barrier();}
static inline int arch_spin_trylock(arch_spinlock_t *lock){ char oldval = lock->slock;
lock->slock = 0; barrier();
return oldval > 0;}
static inline void arch_spin_unlock(arch_spinlock_t *lock){ barrier(); lock->slock = 1;}
#else /* DEBUG_SPINLOCK */#define arch_spin_is_locked(lock) ((void)(lock), 0)/* for sched/core.c and kernel_lock.c: */# define arch_spin_lock(lock) do { barrier(); (void)(lock); } while (0)# define arch_spin_unlock(lock) do { barrier(); (void)(lock); } while (0)# define arch_spin_trylock(lock) ({ barrier(); (void)(lock); 1; })#endif /* DEBUG_SPINLOCK */
#define arch_spin_is_contended(lock) (((void)(lock), 0))
/* * Read-write spinlocks. No debug version. */#define arch_read_lock(lock) do { barrier(); (void)(lock); } while (0)#define arch_write_lock(lock) do { barrier(); (void)(lock); } while (0)#define arch_read_trylock(lock) ({ barrier(); (void)(lock); 1; })#define arch_write_trylock(lock) ({ barrier(); (void)(lock); 1; })#define arch_read_unlock(lock) do { barrier(); (void)(lock); } while (0)#define arch_write_unlock(lock) do { barrier(); (void)(lock); } while (0)
#endif /* __LINUX_SPINLOCK_UP_H */