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#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