swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
Tip revision: e8a7e48bb248a1196484d3f8afa53bded2b24e71 authored by Linus Torvalds on 30 November 2010, 04:42:04 UTC
Linux 2.6.37-rc4
Linux 2.6.37-rc4
Tip revision: e8a7e48
spinlock_up.h
#ifndef __LINUX_SPINLOCK_UP_H
#define __LINUX_SPINLOCK_UP_H
#ifndef __LINUX_SPINLOCK_H
# error "please don't include this file directly"
#endif
/*
* 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.
*/
#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;
}
static inline void
arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
{
local_irq_save(flags);
lock->slock = 0;
}
static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
char oldval = lock->slock;
lock->slock = 0;
return oldval > 0;
}
static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
lock->slock = 1;
}
/*
* Read-write spinlocks. No debug version.
*/
#define arch_read_lock(lock) do { (void)(lock); } while (0)
#define arch_write_lock(lock) do { (void)(lock); } while (0)
#define arch_read_trylock(lock) ({ (void)(lock); 1; })
#define arch_write_trylock(lock) ({ (void)(lock); 1; })
#define arch_read_unlock(lock) do { (void)(lock); } while (0)
#define arch_write_unlock(lock) do { (void)(lock); } while (0)
#else /* DEBUG_SPINLOCK */
#define arch_spin_is_locked(lock) ((void)(lock), 0)
/* for sched.c and kernel_lock.c: */
# define arch_spin_lock(lock) do { (void)(lock); } while (0)
# define arch_spin_lock_flags(lock, flags) do { (void)(lock); } while (0)
# define arch_spin_unlock(lock) do { (void)(lock); } while (0)
# define arch_spin_trylock(lock) ({ (void)(lock); 1; })
#endif /* DEBUG_SPINLOCK */
#define arch_spin_is_contended(lock) (((void)(lock), 0))
#define arch_read_can_lock(lock) (((void)(lock), 1))
#define arch_write_can_lock(lock) (((void)(lock), 1))
#define arch_spin_unlock_wait(lock) \
do { cpu_relax(); } while (arch_spin_is_locked(lock))
#endif /* __LINUX_SPINLOCK_UP_H */