arch/cris/kernel/irq.c

   1 /*
   2  *
   3  *      linux/arch/cris/kernel/irq.c
   4  *
   5  *      Copyright (c) 2000,2007 Axis Communications AB
   6  *
   7  *      Authors: Bjorn Wesen (bjornw@axis.com)
   8  *
   9  * This file contains the code used by various IRQ handling routines:
  10  * asking for different IRQs should be done through these routines
  11  * instead of just grabbing them. Thus setups with different IRQ numbers
  12  * shouldn't result in any weird surprises, and installing new handlers
  13  * should be easier.
  14  *
  15  */
  16
  17 /*
  18  * IRQs are in fact implemented a bit like signal handlers for the kernel.
  19  * Naturally it's not a 1:1 relation, but there are similarities.
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/ptrace.h>
  24 #include <linux/irq.h>
  25
  26 #include <linux/kernel_stat.h>
  27 #include <linux/signal.h>
  28 #include <linux/sched.h>
  29 #include <linux/ioport.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/timex.h>
  32 #include <linux/slab.h>
  33 #include <linux/random.h>
  34 #include <linux/init.h>
  35 #include <linux/seq_file.h>
  36 #include <linux/errno.h>
  37 #include <linux/spinlock.h>
  38
  39 #include <asm/io.h>
  40
  41 int show_interrupts(struct seq_file *p, void *v)
  42 {
  43         int i = *(loff_t *) v, j;
  44         struct irqaction * action;
  45         unsigned long flags;
  46
  47         if (i == 0) {
  48                 seq_printf(p, "           ");
  49                 for_each_online_cpu(j)
  50                         seq_printf(p, "CPU%d       ",j);
  51                 seq_putc(p, '\n');
  52         }
  53
  54         if (i < NR_IRQS) {
  55                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  56                 action = irq_desc[i].action;
  57                 if (!action)
  58                         goto skip;
  59                 seq_printf(p, "%3d: ",i);
  60 #ifndef CONFIG_SMP
  61                 seq_printf(p, "%10u ", kstat_irqs(i));
  62 #else
  63                 for_each_online_cpu(j)
  64                         seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
  65 #endif
  66                 seq_printf(p, " %14s", irq_desc[i].chip->typename);
  67                 seq_printf(p, "  %s", action->name);
  68
  69                 for (action=action->next; action; action = action->next)
  70                         seq_printf(p, ", %s", action->name);
  71
  72                 seq_putc(p, '\n');
  73 skip:
  74                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  75         }
  76         return 0;
  77 }
  78
  79
  80 /* called by the assembler IRQ entry functions defined in irq.h
  81  * to dispatch the interrupts to registered handlers
  82  * interrupts are disabled upon entry - depending on if the
  83  * interrupt was registered with IRQF_DISABLED or not, interrupts
  84  * are re-enabled or not.
  85  */
  86
  87 asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
  88 {
  89         unsigned long sp;
  90         struct pt_regs *old_regs = set_irq_regs(regs);
  91         irq_enter();
  92         sp = rdsp();
  93         if (unlikely((sp & (PAGE_SIZE - 1)) < (PAGE_SIZE/8))) {
  94                 printk("do_IRQ: stack overflow: %lX\n", sp);
  95                 show_stack(NULL, (unsigned long *)sp);
  96         }
  97         __do_IRQ(irq);
  98         irq_exit();
  99         set_irq_regs(old_regs);
 100 }
 101
 102 void weird_irq(void)
 103 {
 104         local_irq_disable();
 105         printk("weird irq\n");
 106         while(1);
 107 }
 108