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/random.h>
  33 #include <linux/init.h>
  34 #include <linux/seq_file.h>
  35 #include <linux/errno.h>
  36 #include <linux/spinlock.h>
  37
  38 #include <asm/io.h>
  39
  40 int show_interrupts(struct seq_file *p, void *v)
  41 {
  42         int i = *(loff_t *) v, j;
  43         struct irqaction * action;
  44         unsigned long flags;
  45
  46         if (i == 0) {
  47                 seq_printf(p, "           ");
  48                 for_each_online_cpu(j)
  49                         seq_printf(p, "CPU%d       ",j);
  50                 seq_putc(p, '\n');
  51         }
  52
  53         if (i < NR_IRQS) {
  54                 raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
  55                 action = irq_desc[i].action;
  56                 if (!action)
  57                         goto skip;
  58                 seq_printf(p, "%3d: ",i);
  59 #ifndef CONFIG_SMP
  60                 seq_printf(p, "%10u ", kstat_irqs(i));
  61 #else
  62                 for_each_online_cpu(j)
  63                         seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
  64 #endif
  65                 seq_printf(p, " %14s", irq_desc[i].chip->name);
  66                 seq_printf(p, "  %s", action->name);
  67
  68                 for (action=action->next; action; action = action->next)
  69                         seq_printf(p, ", %s", action->name);
  70
  71                 seq_putc(p, '\n');
  72 skip:
  73                 raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  74         }
  75         return 0;
  76 }
  77
  78
  79 /* called by the assembler IRQ entry functions defined in irq.h
  80  * to dispatch the interrupts to registered handlers
  81  * interrupts are disabled upon entry - depending on if the
  82  * interrupt was registered with IRQF_DISABLED or not, interrupts
  83  * are re-enabled or not.
  84  */
  85
  86 asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
  87 {
  88         unsigned long sp;
  89         struct pt_regs *old_regs = set_irq_regs(regs);
  90         irq_enter();
  91         sp = rdsp();
  92         if (unlikely((sp & (PAGE_SIZE - 1)) < (PAGE_SIZE/8))) {
  93                 printk("do_IRQ: stack overflow: %lX\n", sp);
  94                 show_stack(NULL, (unsigned long *)sp);
  95         }
  96         __do_IRQ(irq);
  97         irq_exit();
  98         set_irq_regs(old_regs);
  99 }
 100
 101 void weird_irq(void)
 102 {
 103         local_irq_disable();
 104         printk("weird irq\n");
 105         while(1);
 106 }
 107