-extern irqreturn_t (*(*mach_default_handler)[]) (int, void *, struct pt_regs *);
-extern int (*mach_request_irq) (unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_regs *),
- unsigned long flags, const char *devname, void *dev_id);
-extern void (*mach_free_irq) (unsigned int irq, void *dev_id);