arch/x86_64/kernel/irq.c

   1 /*
   2  *      linux/arch/x86_64/kernel/irq.c
   3  *
   4  *      Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
   5  *
   6  * This file contains the lowest level x86_64-specific interrupt
   7  * entry and irq statistics code. All the remaining irq logic is
   8  * done by the generic kernel/irq/ code and in the
   9  * x86_64-specific irq controller code. (e.g. i8259.c and
  10  * io_apic.c.)
  11  */
  12
  13 #include <linux/kernel_stat.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/module.h>
  17 #include <asm/uaccess.h>
  18 #include <asm/io_apic.h>
  19
  20 atomic_t irq_err_count;
  21 #ifdef CONFIG_X86_IO_APIC
  22 #ifdef APIC_MISMATCH_DEBUG
  23 atomic_t irq_mis_count;
  24 #endif
  25 #endif
  26
  27 /*
  28  * Generic, controller-independent functions:
  29  */
  30
  31 int show_interrupts(struct seq_file *p, void *v)
  32 {
  33         int i = *(loff_t *) v, j;
  34         struct irqaction * action;
  35         unsigned long flags;
  36
  37         if (i == 0) {
  38                 seq_printf(p, "           ");
  39                 for (j=0; j<NR_CPUS; j++)
  40                         if (cpu_online(j))
  41                                 seq_printf(p, "CPU%d       ",j);
  42                 seq_putc(p, '\n');
  43         }
  44
  45         if (i < NR_IRQS) {
  46                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  47                 action = irq_desc[i].action;
  48                 if (!action)
  49                         goto skip;
  50                 seq_printf(p, "%3d: ",i);
  51 #ifndef CONFIG_SMP
  52                 seq_printf(p, "%10u ", kstat_irqs(i));
  53 #else
  54                 for (j=0; j<NR_CPUS; j++)
  55                         if (cpu_online(j))
  56                         seq_printf(p, "%10u ",
  57                                 kstat_cpu(j).irqs[i]);
  58 #endif
  59                 seq_printf(p, " %14s", irq_desc[i].handler->typename);
  60
  61                 seq_printf(p, "  %s", action->name);
  62                 for (action=action->next; action; action = action->next)
  63                         seq_printf(p, ", %s", action->name);
  64                 seq_putc(p, '\n');
  65 skip:
  66                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  67         } else if (i == NR_IRQS) {
  68                 seq_printf(p, "NMI: ");
  69                 for (j = 0; j < NR_CPUS; j++)
  70                         if (cpu_online(j))
  71                                 seq_printf(p, "%10u ", cpu_pda[j].__nmi_count);
  72                 seq_putc(p, '\n');
  73 #ifdef CONFIG_X86_LOCAL_APIC
  74                 seq_printf(p, "LOC: ");
  75                 for (j = 0; j < NR_CPUS; j++)
  76                         if (cpu_online(j))
  77                                 seq_printf(p, "%10u ", cpu_pda[j].apic_timer_irqs);
  78                 seq_putc(p, '\n');
  79 #endif
  80                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
  81 #ifdef CONFIG_X86_IO_APIC
  82 #ifdef APIC_MISMATCH_DEBUG
  83                 seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
  84 #endif
  85 #endif
  86         }
  87         return 0;
  88 }
  89
  90 /*
  91  * do_IRQ handles all normal device IRQ's (the special
  92  * SMP cross-CPU interrupts have their own specific
  93  * handlers).
  94  */
  95 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
  96 {
  97         /* high bits used in ret_from_ code  */
  98         unsigned irq = regs->orig_rax & 0xff;
  99
 100         irq_enter();
 101         BUG_ON(irq > 256);
 102
 103         __do_IRQ(irq, regs);
 104         irq_exit();
 105
 106         return 1;
 107 }
 108