Linux中断体系结构

//-----------------------------------------------

/*

NR_IRQS定义in linux/arch/arm/plat-s3c64xx/include/mach/irqs.h

*/

#define NR_IRQS (IRQ_EINT_GROUP9_BASE + IRQ_EINT_GROUP9_NR + 1)

asmlinkage void __init start_kernel(void)

-->early_irq_init();

-->init_IRQ();

-->init_arch_irq();

/*

arch/arm/kernel/irq.c中声明init_arch_irq函数指针

*/

void (*init_arch_irq)(void) __initdata = NULL; /*全局函数指针*/

void __init setup_arch(char **cmdline_p)

-->init_arch_irq = mdesc->init_irq;//s3c6410_init_irq

/*

linux/arch/arm/mach-s3c6410/mach-smdk6410.c中定义machine_desc结构体

*/

MACHINE_START(SMDK6410, 'SMDK6410')

/* Maintainer: Ben Dooks */

.phys_io = S3C_PA_UART & 0xfff00000,

.io_pg_offst = (((u32)S3C_VA_UART) >> 18) & 0xfffc,

.boot_params = S3C64XX_PA_SDRAM + 0x100,

.init_irq = s3c6410_init_irq,

.map_io = smdk6410_map_io,

.init_machine = smdk6410_machine_init,

.timer = &s3c24xx_timer,

MACHINE_END

/*

s3c6410_init_irq in linux/arch/arm/mach-s3c6410/cpu.c

*/

void __init s3c64xx_init_irq(u32 vic0_valid, u32 vic1_valid)

{

int uart, irq;

printk(KERN_DEBUG '%s: initialising interruptsn', __func__);

/* initialise the pair of VICs */

vic_init(S3C_VA_VIC0, S3C_VIC0_BASE, vic0_valid);

vic_init(S3C_VA_VIC1, S3C_VIC1_BASE, vic1_valid);

/* add the timer sub-irqs */

set_irq_chained_handler(IRQ_TIMER0_VIC, s3c_irq_demux_timer0);

set_irq_chained_handler(IRQ_TIMER1_VIC, s3c_irq_demux_timer1);

set_irq_chained_handler(IRQ_TIMER2_VIC, s3c_irq_demux_timer2);

set_irq_chained_handler(IRQ_TIMER3_VIC, s3c_irq_demux_timer3);

set_irq_chained_handler(IRQ_TIMER4_VIC, s3c_irq_demux_timer4);

for (irq = IRQ_TIMER0; irq <= IRQ_TIMER4; irq++) {

set_irq_chip(irq, &s3c_irq_timer);

set_irq_handler(irq, handle_level_irq);

set_irq_flags(irq, IRQF_VALID);

}

for (uart = 0; uart < ARRAY_SIZE(uart_irqs); uart++)

s3c64xx_uart_irq(&uart_irqs[uart]);

}

#define IRQ_EINT_GROUP(group, no) (IRQ_EINT_GROUP##group##_BASE + (no))

/*

IRQ_EINT_GROUP(1, 3)展开为

IRQ_EINT_GROUP1_BASE + 3

*/