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 #include <asm/smp.h>
  22
  23 atomic_t irq_err_count;
  24
  25 #ifdef CONFIG_DEBUG_STACKOVERFLOW
  26 /*
  27  * Probabilistic stack overflow check:
  28  *
  29  * Only check the stack in process context, because everything else
  30  * runs on the big interrupt stacks. Checking reliably is too expensive,
  31  * so we just check from interrupts.
  32  */
  33 static inline void stack_overflow_check(struct pt_regs *regs)
  34 {
  35         u64 curbase = (u64) current->thread_info;
  36         static unsigned long warned = -60*HZ;
  37
  38         if (regs->rsp >= curbase && regs->rsp <= curbase + THREAD_SIZE &&
  39             regs->rsp <  curbase + sizeof(struct thread_info) + 128 &&
  40             time_after(jiffies, warned + 60*HZ)) {
  41                 printk("do_IRQ: %s near stack overflow (cur:%Lx,rsp:%lx)\n",
  42                        current->comm, curbase, regs->rsp);
  43                 show_stack(NULL,NULL);
  44                 warned = jiffies;
  45         }
  46 }
  47 #endif
  48
  49 /*
  50  * Generic, controller-independent functions:
  51  */
  52
  53 int show_interrupts(struct seq_file *p, void *v)
  54 {
  55         int i = *(loff_t *) v, j;
  56         struct irqaction * action;
  57         unsigned long flags;
  58
  59         if (i == 0) {
  60                 seq_printf(p, "           ");
  61                 for_each_online_cpu(j)
  62                         seq_printf(p, "CPU%-8d",j);
  63                 seq_putc(p, '\n');
  64         }
  65
  66         if (i < NR_IRQS) {
  67                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  68                 action = irq_desc[i].action;
  69                 if (!action)
  70                         goto skip;
  71                 seq_printf(p, "%3d: ",i);
  72 #ifndef CONFIG_SMP
  73                 seq_printf(p, "%10u ", kstat_irqs(i));
  74 #else
  75                 for_each_online_cpu(j)
  76                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  77 #endif
  78                 seq_printf(p, " %8s", irq_desc[i].chip->name);
  79                 seq_printf(p, "-%-8s", irq_desc[i].name);
  80
  81                 seq_printf(p, "  %s", action->name);
  82                 for (action=action->next; action; action = action->next)
  83                         seq_printf(p, ", %s", action->name);
  84                 seq_putc(p, '\n');
  85 skip:
  86                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  87         } else if (i == NR_IRQS) {
  88                 seq_printf(p, "NMI: ");
  89                 for_each_online_cpu(j)
  90                         seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
  91                 seq_putc(p, '\n');
  92                 seq_printf(p, "LOC: ");
  93                 for_each_online_cpu(j)
  94                         seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
  95                 seq_putc(p, '\n');
  96                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
  97         }
  98         return 0;
  99 }
 100
 101 /*
 102  * do_IRQ handles all normal device IRQ's (the special
 103  * SMP cross-CPU interrupts have their own specific
 104  * handlers).
 105  */
 106 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 107 {
 108         struct pt_regs *old_regs = set_irq_regs(regs);
 109
 110         /* high bit used in ret_from_ code  */
 111         unsigned vector = ~regs->orig_rax;
 112         unsigned irq;
 113
 114         exit_idle();
 115         irq_enter();
 116         irq = __get_cpu_var(vector_irq)[vector];
 117
 118 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 119         stack_overflow_check(regs);
 120 #endif
 121
 122         if (likely(irq < NR_IRQS))
 123                 generic_handle_irq(irq);
 124         else {
 125                 if (!disable_apic)
 126                         ack_APIC_irq();
 127
 128                 if (printk_ratelimit())
 129                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
 130                                 __func__, smp_processor_id(), vector);
 131         }
 132
 133         irq_exit();
 134
 135         set_irq_regs(old_regs);
 136         return 1;
 137 }
 138
 139 #ifdef CONFIG_HOTPLUG_CPU
 140 void fixup_irqs(cpumask_t map)
 141 {
 142         unsigned int irq;
 143         static int warned;
 144
 145         for (irq = 0; irq < NR_IRQS; irq++) {
 146                 cpumask_t mask;
 147                 if (irq == 2)
 148                         continue;
 149
 150                 cpus_and(mask, irq_desc[irq].affinity, map);
 151                 if (any_online_cpu(mask) == NR_CPUS) {
 152                         printk("Breaking affinity for irq %i\n", irq);
 153                         mask = map;
 154                 }
 155                 if (irq_desc[irq].chip->set_affinity)
 156                         irq_desc[irq].chip->set_affinity(irq, mask);
 157                 else if (irq_desc[irq].action && !(warned++))
 158                         printk("Cannot set affinity for irq %i\n", irq);
 159         }
 160
 161         /* That doesn't seem sufficient.  Give it 1ms. */
 162         local_irq_enable();
 163         mdelay(1);
 164         local_irq_disable();
 165 }
 166 #endif
 167
 168 extern void call_softirq(void);
 169
 170 asmlinkage void do_softirq(void)
 171 {
 172         __u32 pending;
 173         unsigned long flags;
 174
 175         if (in_interrupt())
 176                 return;
 177
 178         local_irq_save(flags);
 179         pending = local_softirq_pending();
 180         /* Switch to interrupt stack */
 181         if (pending) {
 182                 call_softirq();
 183                 WARN_ON_ONCE(softirq_count());
 184         }
 185         local_irq_restore(flags);
 186 }
 187 EXPORT_SYMBOL(do_softirq);