#ifndef ASMARM_SEMAPHORE_HELPER_H
  #define ASMARM_SEMAPHORE_HELPER_H
  
  /*
   * These two _must_ execute atomically wrt each other.
   */
  static inline void wake_one_more(struct semaphore * sem)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&semaphore_wake_lock, flags);
  	if (atomic_read(&sem->count) <= 0)
  		sem->waking++;
  	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
  }
  
  static inline int waking_non_zero(struct semaphore *sem)
  {
  	unsigned long flags;
  	int ret = 0;
  
  	spin_lock_irqsave(&semaphore_wake_lock, flags);
  	if (sem->waking > 0) {
  		sem->waking--;
  		ret = 1;
  	}
  	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
  	return ret;
  }
  
  /*
   * waking non zero interruptible
   *	1	got the lock
   *	0	go to sleep
   *	-EINTR	interrupted
   *
   * We must undo the sem->count down_interruptible() increment while we are
   * protected by the spinlock in order to make this atomic_inc() with the
   * atomic_read() in wake_one_more(), otherwise we can race. -arca
   */
  static inline int waking_non_zero_interruptible(struct semaphore *sem,
  						struct task_struct *tsk)
  {
  	unsigned long flags;
  	int ret = 0;
  
  	spin_lock_irqsave(&semaphore_wake_lock, flags);
  	if (sem->waking > 0) {
  		sem->waking--;
  		ret = 1;
  	} else if (signal_pending(tsk)) {
  		atomic_inc(&sem->count);
  		ret = -EINTR;
  	}
  	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
  	return ret;	
  }
  
  /*
   * waking_non_zero_try_lock:
   *	1	failed to lock
   *	0	got the lock
   *
   * We must undo the sem->count down_interruptible() increment while we are
   * protected by the spinlock in order to make this atomic_inc() with the
   * atomic_read() in wake_one_more(), otherwise we can race. -arca
   */
  static inline int waking_non_zero_trylock(struct semaphore *sem)
  {
  	unsigned long flags;
  	int ret = 1;
  
  	spin_lock_irqsave(&semaphore_wake_lock, flags);
  	if (sem->waking <= 0)
  		atomic_inc(&sem->count);
  	else {
  		sem->waking--;
  		ret = 0;
  	}
  	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
  	return ret;
  }
  
  #endif