Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * taken from cris port.

 *

 * SMP- and interrupt-safe semaphores helper functions. Generic versions, no

 * optimizations whatsoever...

 *

 */

#ifndef _OR32_SEMAPHORE_HELPER_H

#define _OR32_SEMAPHORE_HELPER_H

#include <asm/atomic.h>

#include <linux/errno.h>

#define read(a) ((a)->counter)

#define inc(a) (((a)->counter)++)

#define dec(a) (((a)->counter)--)

#define count_inc(a) ((*(a))++)

/*

 * These two _must_ execute atomically wrt each other.

 */

static inline void wake_one_more(struct semaphore * sem)

{

        atomic_inc(&sem->waking);

}

static inline int waking_non_zero(struct semaphore *sem)

{

        unsigned long flags;

        int ret = 0;

        local_irq_save(flags);

        if (read(&sem->waking) > 0) {

                dec(&sem->waking);

                ret = 1;

        }

        local_irq_restore(flags);

        return ret;

}

static inline int waking_non_zero_interruptible(struct semaphore *sem,

                                                struct task_struct *tsk)

{

        int ret = 0;

        unsigned long flags;

        local_irq_save(flags);

        if (read(&sem->waking) > 0) {

                dec(&sem->waking);

                ret = 1;

        } else if (signal_pending(tsk)) {

                inc(&sem->count);

                ret = -EINTR;

        }

        local_irq_restore(flags);

        return ret;

}

static inline int waking_non_zero_trylock(struct semaphore *sem)

{

        int ret = 1;

        unsigned long flags;

        local_irq_save(flags);

        if (read(&sem->waking) <= 0)

                inc(&sem->count);

        else {

                dec(&sem->waking);

                ret = 0;

        }

        local_irq_restore(flags);

        return ret;

}

#endif