中断学习之基本数据结构

CONFIG_IRQTACKS决定中断栈是独立的还是依附于内核栈。

 

irq_desc {

    irq_flow_handler_t handle_irq;;中断处理函数，会调用ISR

    irq_chip;//中断控制器对象，抽象不同种类的PIC，例如8259控制器

    irqaction *action;//共享中断链表，中断例程ISR

}

关系可以通过中断处理程序看出来

desc->handle_irq = handle_level_irq;//Mpc8xx_pic.c (c:\linux\linux-2.6.23\arch\powerpc\sysdev):
	=>desc->chip->ack(irq);/* Start handling the irq */
	=>desc->status |= IRQ_INPROGRESS;/* Mark the IRQ currently in progress.*/
	=>do//可能好几个中断都上报
		desc->status &= ~IRQ_PENDING;
		action_ret = handle_IRQ_event(irq, action);
			=>do//依次查看是否共享中断
				ret = action->handler(irq, action->dev_id);
				retval |= ret;
				action = action->next;
			=>while (action);
	=>while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);