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 <linux/delay.h>
  18 #include <asm/uaccess.h>
  19 #include <asm/io_apic.h>
  20 #include <asm/idle.h>
  21
  22 atomic_t irq_err_count;
  23 #ifdef CONFIG_X86_IO_APIC
  24 #ifdef APIC_MISMATCH_DEBUG
  25 atomic_t irq_mis_count;
  26 #endif
  27 #endif
  28
  29 /*
  30  * Generic, controller-independent functions:
  31  */
  32
  33 int show_interrupts(struct seq_file *p, void *v)
  34 {
  35         int i = *(loff_t *) v, j;
  36         struct irqaction * action;
  37         unsigned long flags;
  38
  39         if (i == 0) {
  40                 seq_printf(p, "           ");
  41                 for_each_online_cpu(j)
  42                         seq_printf(p, "CPU%d       ",j);
  43                 seq_putc(p, '\n');
  44         }
  45
  46         if (i < NR_IRQS) {
  47                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  48                 action = irq_desc[i].action;
  49                 if (!action)
  50                         goto skip;
  51                 seq_printf(p, "%3d: ",i);
  52 #ifndef CONFIG_SMP
  53                 seq_printf(p, "%10u ", kstat_irqs(i));
  54 #else
  55                 for_each_online_cpu(j)
  56                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  57 #endif
  58                 seq_printf(p, " %14s", irq_desc[i].handler->typename);
  59
  60                 seq_printf(p, "  %s", action->name);
  61                 for (action=action->next; action; action = action->next)
  62                         seq_printf(p, ", %s", action->name);
  63                 seq_putc(p, '\n');
  64 skip:
  65                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  66         } else if (i == NR_IRQS) {
  67                 seq_printf(p, "NMI: ");
  68                 for_each_online_cpu(j)
  69                         seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
  70                 seq_putc(p, '\n');
  71 #ifdef CONFIG_X86_LOCAL_APIC
  72                 seq_printf(p, "LOC: ");
  73                 for_each_online_cpu(j)
  74                         seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
  75                 seq_putc(p, '\n');
  76 #endif
  77                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
  78 #ifdef CONFIG_X86_IO_APIC
  79 #ifdef APIC_MISMATCH_DEBUG
  80                 seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
  81 #endif
  82 #endif
  83         }
  84         return 0;
  85 }
  86
  87 /*
  88  * do_IRQ handles all normal device IRQ's (the special
  89  * SMP cross-CPU interrupts have their own specific
  90  * handlers).
  91  */
  92 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
  93 {
  94         /* high bits used in ret_from_ code  */
  95         unsigned irq = regs->orig_rax & 0xff;
  96
  97         exit_idle();
  98         irq_enter();
  99
 100         __do_IRQ(irq, regs);
 101         irq_exit();
 102
 103         return 1;
 104 }
 105
 106 #ifdef CONFIG_HOTPLUG_CPU
 107 void fixup_irqs(cpumask_t map)
 108 {
 109         unsigned int irq;
 110         static int warned;
 111
 112         for (irq = 0; irq < NR_IRQS; irq++) {
 113                 cpumask_t mask;
 114                 if (irq == 2)
 115                         continue;
 116
 117                 cpus_and(mask, irq_affinity[irq], map);
 118                 if (any_online_cpu(mask) == NR_CPUS) {
 119                         printk("Breaking affinity for irq %i\n", irq);
 120                         mask = map;
 121                 }
 122                 if (irq_desc[irq].handler->set_affinity)
 123                         irq_desc[irq].handler->set_affinity(irq, mask);
 124                 else if (irq_desc[irq].action && !(warned++))
 125                         printk("Cannot set affinity for irq %i\n", irq);
 126         }
 127
 128         /* That doesn't seem sufficient.  Give it 1ms. */
 129         local_irq_enable();
 130         mdelay(1);
 131         local_irq_disable();
 132 }
 133 #endif
 134
 135 extern void call_softirq(void);
 136
 137 asmlinkage void do_softirq(void)
 138 {
 139         __u32 pending;
 140         unsigned long flags;
 141
 142         if (in_interrupt())
 143                 return;
 144
 145         local_irq_save(flags);
 146         pending = local_softirq_pending();
 147         /* Switch to interrupt stack */
 148         if (pending)
 149                 call_softirq();
 150         local_irq_restore(flags);
 151 }
 152 EXPORT_SYMBOL(do_softirq);