arch/mips/kernel/irq.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Code to handle x86 style IRQs plus some generic interrupt stuff.
   7  *
   8  * Copyright (C) 1992 Linus Torvalds
   9  * Copyright (C) 1994 - 2000 Ralf Baechle
  10  */
  11 #include <linux/config.h>
  12 #include <linux/kernel.h>
  13 #include <linux/delay.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/kernel_stat.h>
  17 #include <linux/module.h>
  18 #include <linux/proc_fs.h>
  19 #include <linux/slab.h>
  20 #include <linux/mm.h>
  21 #include <linux/random.h>
  22 #include <linux/sched.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/kallsyms.h>
  25
  26 #include <asm/atomic.h>
  27 #include <asm/system.h>
  28 #include <asm/uaccess.h>
  29
  30 /*
  31  * 'what should we do if we get a hw irq event on an illegal vector'.
  32  * each architecture has to answer this themselves.
  33  */
  34 void ack_bad_irq(unsigned int irq)
  35 {
  36         printk("unexpected IRQ # %d\n", irq);
  37 }
  38
  39 atomic_t irq_err_count;
  40
  41 #undef do_IRQ
  42
  43 /*
  44  * do_IRQ handles all normal device IRQ's (the special
  45  * SMP cross-CPU interrupts have their own specific
  46  * handlers).
  47  */
  48 asmlinkage unsigned int do_IRQ(unsigned int irq, struct pt_regs *regs)
  49 {
  50         irq_enter();
  51
  52         __do_IRQ(irq, regs);
  53
  54         irq_exit();
  55
  56         return 1;
  57 }
  58
  59 /*
  60  * Generic, controller-independent functions:
  61  */
  62
  63 int show_interrupts(struct seq_file *p, void *v)
  64 {
  65         int i = *(loff_t *) v, j;
  66         struct irqaction * action;
  67         unsigned long flags;
  68
  69         if (i == 0) {
  70                 seq_printf(p, "           ");
  71                 for_each_online_cpu(j)
  72                         seq_printf(p, "CPU%d       ",j);
  73                 seq_putc(p, '\n');
  74         }
  75
  76         if (i < NR_IRQS) {
  77                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  78                 action = irq_desc[i].action;
  79                 if (!action)
  80                         goto skip;
  81                 seq_printf(p, "%3d: ",i);
  82 #ifndef CONFIG_SMP
  83                 seq_printf(p, "%10u ", kstat_irqs(i));
  84 #else
  85                 for_each_online_cpu(j)
  86                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  87 #endif
  88                 seq_printf(p, " %14s", irq_desc[i].handler->typename);
  89                 seq_printf(p, "  %s", action->name);
  90
  91                 for (action=action->next; action; action = action->next)
  92                         seq_printf(p, ", %s", action->name);
  93
  94                 seq_putc(p, '\n');
  95 skip:
  96                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  97         } else if (i == NR_IRQS) {
  98                 seq_putc(p, '\n');
  99                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 100         }
 101         return 0;
 102 }
 103
 104 asmlinkage void spurious_interrupt(struct pt_regs *regs)
 105 {
 106         atomic_inc(&irq_err_count);
 107 }
 108
 109 #ifdef CONFIG_KGDB
 110 extern void breakpoint(void);
 111 extern void set_debug_traps(void);
 112
 113 static int kgdb_flag = 1;
 114 static int __init nokgdb(char *str)
 115 {
 116         kgdb_flag = 0;
 117         return 1;
 118 }
 119 __setup("nokgdb", nokgdb);
 120 #endif
 121
 122 void __init init_IRQ(void)
 123 {
 124         int i;
 125
 126         for (i = 0; i < NR_IRQS; i++) {
 127                 irq_desc[i].status  = IRQ_DISABLED;
 128                 irq_desc[i].action  = NULL;
 129                 irq_desc[i].depth   = 1;
 130                 irq_desc[i].handler = &no_irq_type;
 131                 spin_lock_init(&irq_desc[i].lock);
 132         }
 133
 134         arch_init_irq();
 135
 136 #ifdef CONFIG_KGDB
 137         if (kgdb_flag) {
 138                 printk("Wait for gdb client connection ...\n");
 139                 set_debug_traps();
 140                 breakpoint();
 141         }
 142 #endif
 143 }