extern int setup_irq(unsigned int irq, struct irqaction *irqaction);
static struct irqaction irq_cascade = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL };
extern int setup_irq(unsigned int irq, struct irqaction *irqaction);
static struct irqaction irq_cascade = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL };