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   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
  21 atomic_t irq_err_count;
  22 #ifdef CONFIG_X86_IO_APIC
  23 #ifdef APIC_MISMATCH_DEBUG
  24 atomic_t irq_mis_count;
  25 #endif
  26 #endif
  27
  28 /*
  29  * Generic, controller-independent functions:
  30  */
  31
  32 int show_interrupts(struct seq_file *p, void *v)
  33 {
  34         int i = *(loff_t *) v, j;
  35         struct irqaction * action;
  36         unsigned long flags;
  37
  38         if (i == 0) {
  39                 seq_printf(p, "           ");
  40                 for (j=0; j<NR_CPUS; j++)
  41                         if (cpu_online(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 (j=0; j<NR_CPUS; j++)
  56                         if (cpu_online(j))
  57                         seq_printf(p, "%10u ",
  58                                 kstat_cpu(j).irqs[i]);
  59 #endif
  60                 seq_printf(p, " %14s", irq_desc[i].handler->typename);
  61
  62                 seq_printf(p, "  %s", action->name);
  63                 for (action=action->next; action; action = action->next)
  64                         seq_printf(p, ", %s", action->name);
  65                 seq_putc(p, '\n');
  66 skip:
  67                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  68         } else if (i == NR_IRQS) {
  69                 seq_printf(p, "NMI: ");
  70                 for (j = 0; j < NR_CPUS; j++)
  71                         if (cpu_online(j))
  72                                 seq_printf(p, "%10u ", cpu_pda[j].__nmi_count);
  73                 seq_putc(p, '\n');
  74 #ifdef CONFIG_X86_LOCAL_APIC
  75                 seq_printf(p, "LOC: ");
  76                 for (j = 0; j < NR_CPUS; j++)
  77                         if (cpu_online(j))
  78                                 seq_printf(p, "%10u ", cpu_pda[j].apic_timer_irqs);
  79                 seq_putc(p, '\n');
  80 #endif
  81                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
  82 #ifdef CONFIG_X86_IO_APIC
  83 #ifdef APIC_MISMATCH_DEBUG
  84                 seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
  85 #endif
  86 #endif
  87         }
  88         return 0;
  89 }
  90
  91 /*
  92  * do_IRQ handles all normal device IRQ's (the special
  93  * SMP cross-CPU interrupts have their own specific
  94  * handlers).
  95  */
  96 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
  97 {
  98         /* high bits used in ret_from_ code  */
  99         unsigned irq = regs->orig_rax & 0xff;
 100
 101         irq_enter();
 102         BUG_ON(irq > 256);
 103
 104         __do_IRQ(irq, regs);
 105         irq_exit();
 106
 107         return 1;
 108 }
 109
 110 #ifdef CONFIG_HOTPLUG_CPU
 111 void fixup_irqs(cpumask_t map)
 112 {
 113         unsigned int irq;
 114         static int warned;
 115
 116         for (irq = 0; irq < NR_IRQS; irq++) {
 117                 cpumask_t mask;
 118                 if (irq == 2)
 119                         continue;
 120
 121                 cpus_and(mask, irq_affinity[irq], map);
 122                 if (any_online_cpu(mask) == NR_CPUS) {
 123                         printk("Breaking affinity for irq %i\n", irq);
 124                         mask = map;
 125                 }
 126                 if (irq_desc[irq].handler->set_affinity)
 127                         irq_desc[irq].handler->set_affinity(irq, mask);
 128                 else if (irq_desc[irq].action && !(warned++))
 129                         printk("Cannot set affinity for irq %i\n", irq);
 130         }
 131
 132         /* That doesn't seem sufficient.  Give it 1ms. */
 133         local_irq_enable();
 134         mdelay(1);
 135         local_irq_disable();
 136 }
 137 #endif
 138
 139 extern void call_softirq(void);
 140
 141 asmlinkage void do_softirq(void)
 142 {
 143         __u32 pending;
 144         unsigned long flags;
 145
 146         if (in_interrupt())
 147                 return;
 148
 149         local_irq_save(flags);
 150         pending = local_softirq_pending();
 151         /* Switch to interrupt stack */
 152         if (pending)
 153                 call_softirq();
 154         local_irq_restore(flags);
 155 }
 156 EXPORT_SYMBOL(do_softirq);