Linux kernel 中断之proc接口之interrupts

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用于对中断观察的主要有两个文件，一个是proc/irq，另一个是proc/interrupts。

需要配置CONFIG_GENERIC_IRQ_SHOW宏

在proc目录下实现interrupts文件，用于获取中断发生次数统计：

fs/proc/interrupts.c

static const struct seq_operations int_seq_ops = {.start = int_seq_start,.next  = int_seq_next,.stop  = int_seq_stop,.show  = show_interrupts
};
static int interrupts_open(struct inode *inode, struct file *filp)
{return seq_open(filp, &int_seq_ops);
}
static const struct file_operations proc_interrupts_operations = {.open  = interrupts_open,.read  = seq_read,.llseek  = seq_lseek,.release = seq_release,
};
static int __init proc_interrupts_init(void)
{proc_create("interrupts", 0, NULL, &proc_interrupts_operations);return 0;
}
fs_initcall(proc_interrupts_init);
#ifdef CONFIG_GENERIC_IRQ_SHOW
int __weak arch_show_interrupts(struct seq_file *p, int prec)
{return 0;
}
int show_interrupts(struct seq_file *p, void *v)
{static int prec;
 unsigned long flags, any_count = 0;int i = *(loff_t *) v, j;struct irqaction *action;struct irq_desc *desc;
 if (i > ACTUAL_NR_IRQS)return 0;
 if (i == ACTUAL_NR_IRQS)return arch_show_interrupts(p, prec);
 /* print header and calculate the width of the first column */if (i == 0) {for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)j *= 10;
  seq_printf(p, "%*s", prec + 8, "");for_each_online_cpu(j)seq_printf(p, "CPU%-8d", j);seq_putc(p, '\n');}
 irq_lock_sparse();desc = irq_to_desc(i);if (!desc)goto outsparse;
 raw_spin_lock_irqsave(&desc->lock, flags);for_each_online_cpu(j)any_count |= kstat_irqs_cpu(i, j);action = desc->action;if ((!action || irq_desc_is_chained(desc)) && !any_count)goto out;
 seq_printf(p, "%*d: ", prec, i);for_each_online_cpu(j)seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 if (desc->irq_data.chip) {if (desc->irq_data.chip->irq_print_chip)desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);else if (desc->irq_data.chip->name)seq_printf(p, " %8s", desc->irq_data.chip->name);elseseq_printf(p, " %8s", "-");} else {seq_printf(p, " %8s", "None");}if (desc->irq_data.domain)seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
#ifdef CONFIG_GENERIC_IRQ_SHOW_LEVELseq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
#endifif (desc->name)seq_printf(p, "-%-8s", desc->name);
 if (action) {seq_printf(p, "  %s", action->name);while ((action = action->next) != NULL)seq_printf(p, ", %s", action->name);}
 seq_putc(p, '\n');
out:raw_spin_unlock_irqrestore(&desc->lock, flags);
outsparse:irq_unlock_sparse();return 0;
}
#endif
/proc # cat interrupts
cat interruptsCPU0       CPU1  29:       0          0          GIC  arch_timer30:    1923       1077          GIC  arch_timer34:       0          0          GIC  fa608000.ap_dmas38:       0          0          GIC  MIPI irq43:       0          0          GIC  fa100000.gpu44:       0          0          GIC  fa100000.gpu45:       1          0          GIC  fa100000.gpu49:     279          0          GIC  dwc351:    2856          0          GIC  malidp-de52:       0          0          GIC  malidp-se53:     392          0          GIC  isp_irq