xen/linux-2.4-xen-sparse/include/linux/irq.h

#ifndef __irq_h
#define __irq_h

/*
 * Please do not include this file in generic code.  There is currently
 * no requirement for any architecture to implement anything held
 * within this file.
 *
 * Thanks. --rmk
 */

#include <linux/config.h>

#if !defined(CONFIG_ARCH_S390)

#include <linux/cache.h>
#include <linux/spinlock.h>

#include <asm/irq.h>
#include <asm/ptrace.h>

/*
 * IRQ line status.
 */
#define IRQ_INPROGRESS	1	/* IRQ handler active - do not enter! */
#define IRQ_DISABLED	2	/* IRQ disabled - do not enter! */
#define IRQ_PENDING	4	/* IRQ pending - replay on enable */
#define IRQ_REPLAY	8	/* IRQ has been replayed but not acked yet */
#define IRQ_AUTODETECT	16	/* IRQ is being autodetected */
#define IRQ_WAITING	32	/* IRQ not yet seen - for autodetection */
#define IRQ_LEVEL	64	/* IRQ level triggered */
#define IRQ_MASKED	128	/* IRQ masked - shouldn't be seen again */
#define IRQ_PER_CPU	256	/* IRQ is per CPU */

/*
 * Interrupt controller descriptor. This is all we need
 * to describe about the low-level hardware. 
 */
struct hw_interrupt_type {
	const char * typename;
	unsigned int (*startup)(unsigned int irq);
	void (*shutdown)(unsigned int irq);
	void (*enable)(unsigned int irq);
	void (*disable)(unsigned int irq);
	void (*ack)(unsigned int irq);
	void (*end)(unsigned int irq);
	void (*set_affinity)(unsigned int irq, unsigned long mask);
};

typedef struct hw_interrupt_type  hw_irq_controller;

/*
 * This is the "IRQ descriptor", which contains various information
 * about the irq, including what kind of hardware handling it has,
 * whether it is disabled etc etc.
 *
 * Pad this out to 32 bytes for cache and indexing reasons.
 */
typedef struct {
	unsigned int status;		/* IRQ status */
	hw_irq_controller *handler;
	struct irqaction *action;	/* IRQ action list */
	unsigned int depth;		/* nested irq disables */
	spinlock_t lock;
} ____cacheline_aligned irq_desc_t;

extern irq_desc_t irq_desc [NR_IRQS];

#include <asm/hw_irq.h> /* the arch dependent stuff */

extern int handle_IRQ_event(unsigned int, struct pt_regs *, struct irqaction *);
extern int setup_irq(unsigned int , struct irqaction * );
extern int teardown_irq(unsigned int , struct irqaction * );

extern hw_irq_controller no_irq_type;  /* needed in every arch ? */
extern void no_action(int cpl, void *dev_id, struct pt_regs *regs);

#endif

#endif /* __irq_h */