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/*

 *  include/asm-s390/hardirq.h

 *

 *  S390 version

 *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation

 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),

 *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)

 *

 *  Derived from "include/asm-i386/hardirq.h"

 */

#ifndef __ASM_HARDIRQ_H

#define __ASM_HARDIRQ_H

#include <linux/config.h>

#include <linux/threads.h>

#include <asm/lowcore.h>

#include <linux/sched.h>

/* entry.S is sensitive to the offsets of these fields */

typedef struct {

        unsigned int __softirq_pending;

        unsigned int __local_irq_count;

        unsigned int __local_bh_count;

        unsigned int __syscall_count;

        struct task_struct * __ksoftirqd_task; /* waitqueue is too large */

} ____cacheline_aligned irq_cpustat_t;

#include <linux/irq_cpustat.h>  /* Standard mappings for irq_cpustat_t above */

/*

 * Are we in an interrupt context? Either doing bottom half

 * or hardware interrupt processing?

 */

#define in_interrupt() ({ int __cpu = smp_processor_id(); \

        (local_irq_count(__cpu) + local_bh_count(__cpu) != 0); })

#define in_irq() (local_irq_count(smp_processor_id()) != 0)

#ifndef CONFIG_SMP

#define hardirq_trylock(cpu)    (local_irq_count(cpu) == 0)

#define hardirq_endlock(cpu)    do { } while (0)

#define hardirq_enter(cpu)      (local_irq_count(cpu)++)

#define hardirq_exit(cpu)       (local_irq_count(cpu)--)

#define synchronize_irq()       do { } while (0)

#else   /* CONFIG_SMP */

#include <asm/atomic.h>

#include <asm/smp.h>

extern atomic_t global_irq_holder;

extern atomic_t global_irq_lock;

extern atomic_t global_irq_count;

static inline void release_irqlock(int cpu)

{

        /* if we didn't own the irq lock, just ignore.. */

        if (atomic_read(&global_irq_holder) ==  cpu) {

                atomic_set(&global_irq_holder,NO_PROC_ID);

                atomic_set(&global_irq_lock,0);

        }

}

static inline void hardirq_enter(int cpu)

{

        ++local_irq_count(cpu);

        atomic_inc(&global_irq_count);

}

static inline void hardirq_exit(int cpu)

{

        atomic_dec(&global_irq_count);

        --local_irq_count(cpu);

}

static inline int hardirq_trylock(int cpu)

{

        return !atomic_read(&global_irq_count) &&

               !atomic_read(&global_irq_lock);

}

#define hardirq_endlock(cpu)    do { } while (0)

extern void synchronize_irq(void);

#endif  /* CONFIG_SMP */

#endif /* __ASM_HARDIRQ_H */