/* hardirq.h: 32-bit Sparc hard IRQ support.
 *
 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
 */

#ifndef __SPARC_HARDIRQ_H
#define __SPARC_HARDIRQ_H

#include <linux/tasks.h>

extern unsigned int local_irq_count[NR_CPUS];
#define in_interrupt()	(local_irq_count[smp_processor_id()] != 0)

#ifndef __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()	barrier()

#else /* __SMP__ */

#include <asm/atomic.h>
#include <asm/spinlock.h>
#include <asm/system.h>
#include <asm/smp.h>

extern unsigned char global_irq_holder;
extern spinlock_t global_irq_lock;
extern atomic_t global_irq_count;

#define release_irqlock(cpu)				\
do {	if(global_irq_holder == (unsigned char) cpu) {	\
		global_irq_holder = NO_PROC_ID;		\
		spin_unlock(&global_irq_lock);		\
	}						\
} while(0)

/* Ordering of the counter bumps is _deadly_ important. */
#define hardirq_enter(cpu) \
	do { ++local_irq_count[cpu]; atomic_inc(&global_irq_count); } while(0)

#define hardirq_exit(cpu) \
	do { atomic_dec(&global_irq_count); --local_irq_count[cpu]; } while(0)

#define hardirq_trylock(cpu)					\
({	unsigned long flags; int ret = 1;			\
	__save_flags(flags);					\
	__cli();						\
	if(atomic_add_return(1, &global_irq_count) != 1 ||	\
	   *(((unsigned char *)(&global_irq_lock)))) {		\
		atomic_dec(&global_irq_count);			\
		__restore_flags(flags);				\
		ret = 0;					\
	} else {						\
		++local_irq_count[cpu];				\
		__sti();					\
	}							\
	ret;							\
})

#define hardirq_endlock(cpu) do { __cli(); hardirq_exit(cpu); __sti(); } while(0)

extern void synchronize_irq(void);

#endif /* __SMP__ */

#endif /* __SPARC_HARDIRQ_H */
