arch/x86/kernel/irq_64.c

   1 /*
   2  *      Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
   3  *
   4  * This file contains the lowest level x86_64-specific interrupt
   5  * entry and irq statistics code. All the remaining irq logic is
   6  * done by the generic kernel/irq/ code and in the
   7  * x86_64-specific irq controller code. (e.g. i8259.c and
   8  * io_apic.c.)
   9  */
  10
  11 #include <linux/kernel_stat.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/module.h>
  15 #include <linux/delay.h>
  16 #include <asm/uaccess.h>
  17 #include <asm/io_apic.h>
  18 #include <asm/idle.h>
  19 #include <asm/smp.h>
  20
  21 atomic_t irq_err_count;
  22
  23 #ifdef CONFIG_DEBUG_STACKOVERFLOW
  24 /*
  25  * Probabilistic stack overflow check:
  26  *
  27  * Only check the stack in process context, because everything else
  28  * runs on the big interrupt stacks. Checking reliably is too expensive,
  29  * so we just check from interrupts.
  30  */
  31 static inline void stack_overflow_check(struct pt_regs *regs)
  32 {
  33         u64 curbase = (u64)task_stack_page(current);
  34         static unsigned long warned = -60*HZ;
  35
  36         if (regs->rsp >= curbase && regs->rsp <= curbase + THREAD_SIZE &&
  37             regs->rsp <  curbase + sizeof(struct thread_info) + 128 &&
  38             time_after(jiffies, warned + 60*HZ)) {
  39                 printk("do_IRQ: %s near stack overflow (cur:%Lx,rsp:%lx)\n",
  40                        current->comm, curbase, regs->rsp);
  41                 show_stack(NULL,NULL);
  42                 warned = jiffies;
  43         }
  44 }
  45 #endif
  46
  47 /*
  48  * Generic, controller-independent functions:
  49  */
  50
  51 int show_interrupts(struct seq_file *p, void *v)
  52 {
  53         int i = *(loff_t *) v, j;
  54         struct irqaction * action;
  55         unsigned long flags;
  56
  57         if (i == 0) {
  58                 seq_printf(p, "           ");
  59                 for_each_online_cpu(j)
  60                         seq_printf(p, "CPU%-8d",j);
  61                 seq_putc(p, '\n');
  62         }
  63
  64         if (i < NR_IRQS) {
  65                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  66                 action = irq_desc[i].action;
  67                 if (!action)
  68                         goto skip;
  69                 seq_printf(p, "%3d: ",i);
  70 #ifndef CONFIG_SMP
  71                 seq_printf(p, "%10u ", kstat_irqs(i));
  72 #else
  73                 for_each_online_cpu(j)
  74                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  75 #endif
  76                 seq_printf(p, " %8s", irq_desc[i].chip->name);
  77                 seq_printf(p, "-%-8s", irq_desc[i].name);
  78
  79                 seq_printf(p, "  %s", action->name);
  80                 for (action=action->next; action; action = action->next)
  81                         seq_printf(p, ", %s", action->name);
  82                 seq_putc(p, '\n');
  83 skip:
  84                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  85         } else if (i == NR_IRQS) {
  86                 seq_printf(p, "NMI: ");
  87                 for_each_online_cpu(j)
  88                         seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
  89                 seq_putc(p, '\n');
  90                 seq_printf(p, "LOC: ");
  91                 for_each_online_cpu(j)
  92                         seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
  93                 seq_putc(p, '\n');
  94                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
  95         }
  96         return 0;
  97 }
  98
  99 /*
 100  * do_IRQ handles all normal device IRQ's (the special
 101  * SMP cross-CPU interrupts have their own specific
 102  * handlers).
 103  */
 104 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 105 {
 106         struct pt_regs *old_regs = set_irq_regs(regs);
 107
 108         /* high bit used in ret_from_ code  */
 109         unsigned vector = ~regs->orig_rax;
 110         unsigned irq;
 111
 112         exit_idle();
 113         irq_enter();
 114         irq = __get_cpu_var(vector_irq)[vector];
 115
 116 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 117         stack_overflow_check(regs);
 118 #endif
 119
 120         if (likely(irq < NR_IRQS))
 121                 generic_handle_irq(irq);
 122         else {
 123                 if (!disable_apic)
 124                         ack_APIC_irq();
 125
 126                 if (printk_ratelimit())
 127                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
 128                                 __func__, smp_processor_id(), vector);
 129         }
 130
 131         irq_exit();
 132
 133         set_irq_regs(old_regs);
 134         return 1;
 135 }
 136
 137 #ifdef CONFIG_HOTPLUG_CPU
 138 void fixup_irqs(cpumask_t map)
 139 {
 140         unsigned int irq;
 141         static int warned;
 142
 143         for (irq = 0; irq < NR_IRQS; irq++) {
 144                 cpumask_t mask;
 145                 int break_affinity = 0;
 146                 int set_affinity = 1;
 147
 148                 if (irq == 2)
 149                         continue;
 150
 151                 /* interrupt's are disabled at this point */
 152                 spin_lock(&irq_desc[irq].lock);
 153
 154                 if (!irq_has_action(irq) ||
 155                     cpus_equal(irq_desc[irq].affinity, map)) {
 156                         spin_unlock(&irq_desc[irq].lock);
 157                         continue;
 158                 }
 159
 160                 cpus_and(mask, irq_desc[irq].affinity, map);
 161                 if (cpus_empty(mask)) {
 162                         break_affinity = 1;
 163                         mask = map;
 164                 }
 165
 166                 if (irq_desc[irq].chip->mask)
 167                         irq_desc[irq].chip->mask(irq);
 168
 169                 if (irq_desc[irq].chip->set_affinity)
 170                         irq_desc[irq].chip->set_affinity(irq, mask);
 171                 else if (!(warned++))
 172                         set_affinity = 0;
 173
 174                 if (irq_desc[irq].chip->unmask)
 175                         irq_desc[irq].chip->unmask(irq);
 176
 177                 spin_unlock(&irq_desc[irq].lock);
 178
 179                 if (break_affinity && set_affinity)
 180                         printk("Broke affinity for irq %i\n", irq);
 181                 else if (!set_affinity)
 182                         printk("Cannot set affinity for irq %i\n", irq);
 183         }
 184
 185         /* That doesn't seem sufficient.  Give it 1ms. */
 186         local_irq_enable();
 187         mdelay(1);
 188         local_irq_disable();
 189 }
 190 #endif
 191
 192 extern void call_softirq(void);
 193
 194 asmlinkage void do_softirq(void)
 195 {
 196         __u32 pending;
 197         unsigned long flags;
 198
 199         if (in_interrupt())
 200                 return;
 201
 202         local_irq_save(flags);
 203         pending = local_softirq_pending();
 204         /* Switch to interrupt stack */
 205         if (pending) {
 206                 call_softirq();
 207                 WARN_ON_ONCE(softirq_count());
 208         }
 209         local_irq_restore(flags);
 210 }