中断一

struct irq_desc {
        unsigned int            irq;
        struct timer_rand_state *timer_rand_state;
        unsigned int            *kstat_irqs;
#ifdef CONFIG_INTR_REMAP
        struct irq_2_iommu      *irq_2_iommu;
#endif
        irq_flow_handler_t      handle_irq;
        struct irq_chip         *chip;
        struct msi_desc         *msi_desc;
        void                    *handler_data;
        void                    *chip_data;
        struct irqaction        *action;        /* IRQ action list */
        unsigned int            status;         /* IRQ status */

        unsigned int            depth;          /* nested irq disables */
        unsigned int            wake_depth;     /* nested wake enables */
        unsigned int            irq_count;      /* For detecting broken IRQs */
        unsigned long           last_unhandled; /* Aging timer for unhandled count */
        unsigned int            irqs_unhandled;
        spinlock_t              lock;
#ifdef CONFIG_SMP

        cpumask_var_t           affinity;
        unsigned int            node;
#ifdef CONFIG_GENERIC_PENDING_IRQ
        cpumask_var_t           pending_mask;
#endif
#endif
        atomic_t                threads_active;
        wait_queue_head_t       wait_for_threads;
#ifdef CONFIG_PROC_FS
        struct proc_dir_entry   *dir;
#endif
        const char              *name;
} ____cacheline_internodealigned_in_smp;

 

/kernel/irq/manage.c

int setup_irq(unsigned int irq, struct irqaction *act)
{
        struct irq_desc *desc = irq_to_desc(irq);

        return __setup_irq(irq, desc, act);
}