#ifndef __LINUX_SPINLOCK_UP_H
  #define __LINUX_SPINLOCK_UP_H
  
  #ifndef __LINUX_SPINLOCK_H
  # error "please don't include this file directly"
  #endif

  #include <asm/processor.h>	/* for cpu_relax() */

  /*
   * 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 */