Linux中断初始化

start_kernel()->

    init_IRQ()->

        irqchip_init()->

            of_irq_init(__irqchip_of_table) ## 扫描和初始化设备树中的中断控制器("interrupt-controller")

IRQCHIP_DECLARE(gic_v3, "arm,gic-v3", gic_of_init);

gic_of_init()->

    gic_init_bases()->

        set_handle_irq(gic_handle_irq) ## 设置handle_arch_irq = gic_handle_irq，中断触发时调用

## 1.宏用法

IRQCHIP_DECLARE(gic_v3, "arm,gic-v3", gic_of_init);

## 2.宏定义

#define IRQCHIP_DECLARE(name, compat, fn) OF_DECLARE_2(irqchip, name, compat, fn)

#define OF_DECLARE_2(table, name, compat, fn) \

        _OF_DECLARE(table, name, compat, fn, of_init_fn_2)

#define _OF_DECLARE(table, name, compat, fn, fn_type)           \

    static const struct of_device_id __of_table_##name      \

        __used __section(__##table##_of_table)          \

         = { .compatible = compat,              \

             .data = (fn == (fn_type)NULL) ? fn : fn  }

## 3.宏展开

    static const struct of_device_id __of_table_gic_v3  \

        __used __section(__irqchip_of_table)            \ 

         = { .compatible = "arm,gic-v3",                \

             .data = (gic_of_init == (fn_type)NULL) ? gic_of_init : gic_of_init  }

static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)

{

    ...

    do {

        irqnr = gic_read_iar();

        if (likely(irqnr > 15 && irqnr < 1020) || irqnr >= 8192) { ## 1.1 PPI和SPI中断

            ...

            err = handle_domain_irq(gic_data.domain, irqnr, regs); ## 1.2 中断处理

            ...

        }

        if (irqnr < 16) { ## 2.1 SGI中断

            ...

            handle_IPI(irqnr, regs); ## 2.2 中断处理

            ...

        }

    } while (irqnr != ICC_IAR1_EL1_SPURIOUS);

}