1. 根目录:
2. arch
3. powerpc
4. include
5. asm
6. irq.h

#ifdef __KERNEL__
#ifndef _ASM_POWERPC_IRQ_H
#define _ASM_POWERPC_IRQ_H

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/irqdomain.h>
#include <linux/threads.h>
#include <linux/list.h>
#include <linux/radix-tree.h>

#include <asm/types.h>
#include <linux/atomic.h>


extern atomic_t ppc_n_lost_interrupts;

/* This number is used when no interrupt has been assigned */
#define NO_IRQ			(0)

/* Total number of virq in the platform */
#define NR_IRQS		CONFIG_NR_IRQS

/* Same thing, used by the generic IRQ code */
#define NR_IRQS_LEGACY		NUM_ISA_INTERRUPTS

extern irq_hw_number_t virq_to_hw(unsigned int virq);

static __inline__ int irq_canonicalize(int irq)
{
	return irq;
}

extern int distribute_irqs;

struct irqaction;
struct pt_regs;

#define __ARCH_HAS_DO_SOFTIRQ

#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
/*
 * Per-cpu stacks for handling critical, debug and machine check
 * level interrupts.
 */
extern struct thread_info *critirq_ctx[NR_CPUS];
extern struct thread_info *dbgirq_ctx[NR_CPUS];
extern struct thread_info *mcheckirq_ctx[NR_CPUS];
extern void exc_lvl_ctx_init(void);
#else
#define exc_lvl_ctx_init()
#endif

/*
 * Per-cpu stacks for handling hard and soft interrupts.
 */
extern struct thread_info *hardirq_ctx[NR_CPUS];
extern struct thread_info *softirq_ctx[NR_CPUS];

extern void irq_ctx_init(void);
extern void call_do_softirq(struct thread_info *tp);
extern void call_do_irq(struct pt_regs *regs, struct thread_info *tp);
extern void do_IRQ(struct pt_regs *regs);
extern void __do_irq(struct pt_regs *regs);

int irq_choose_cpu(const struct cpumask *mask);

#endif /* _ASM_IRQ_H */
#endif /* __KERNEL__ */