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/kernel.h>
  12 #include <linux/delay.h>
  13 #include <linux/init.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/kernel_stat.h>
  16 #include <linux/module.h>
  17 #include <linux/proc_fs.h>
  18 #include <linux/slab.h>
  19 #include <linux/mm.h>
  20 #include <linux/random.h>
  21 #include <linux/sched.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/kallsyms.h>
  24
  25 #include <asm/atomic.h>
  26 #include <asm/system.h>
  27 #include <asm/uaccess.h>
  28
  29 /*
  30  * 'what should we do if we get a hw irq event on an illegal vector'.
  31  * each architecture has to answer this themselves.
  32  */
  33 void ack_bad_irq(unsigned int irq)
  34 {
  35         printk("unexpected IRQ # %d\n", irq);
  36 }
  37
  38 atomic_t irq_err_count;
  39
  40 #ifdef CONFIG_MIPS_MT_SMTC
  41 /*
  42  * SMTC Kernel needs to manipulate low-level CPU interrupt mask
  43  * in do_IRQ. These are passed in setup_irq_smtc() and stored
  44  * in this table.
  45  */
  46 unsigned long irq_hwmask[NR_IRQS];
  47 #endif /* CONFIG_MIPS_MT_SMTC */
  48
  49 #undef do_IRQ
  50
  51 /*
  52  * do_IRQ handles all normal device IRQ's (the special
  53  * SMP cross-CPU interrupts have their own specific
  54  * handlers).
  55  */
  56 asmlinkage unsigned int do_IRQ(unsigned int irq, struct pt_regs *regs)
  57 {
  58         irq_enter();
  59
  60         __DO_IRQ_SMTC_HOOK();
  61         __do_IRQ(irq, regs);
  62
  63         irq_exit();
  64
  65         return 1;
  66 }
  67
  68 /*
  69  * Generic, controller-independent functions:
  70  */
  71
  72 int show_interrupts(struct seq_file *p, void *v)
  73 {
  74         int i = *(loff_t *) v, j;
  75         struct irqaction * action;
  76         unsigned long flags;
  77
  78         if (i == 0) {
  79                 seq_printf(p, "           ");
  80                 for_each_online_cpu(j)
  81                         seq_printf(p, "CPU%d       ",j);
  82                 seq_putc(p, '\n');
  83         }
  84
  85         if (i < NR_IRQS) {
  86                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  87                 action = irq_desc[i].action;
  88                 if (!action)
  89                         goto skip;
  90                 seq_printf(p, "%3d: ",i);
  91 #ifndef CONFIG_SMP
  92                 seq_printf(p, "%10u ", kstat_irqs(i));
  93 #else
  94                 for_each_online_cpu(j)
  95                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  96 #endif
  97                 seq_printf(p, " %14s", irq_desc[i].chip->typename);
  98                 seq_printf(p, "  %s", action->name);
  99
 100                 for (action=action->next; action; action = action->next)
 101                         seq_printf(p, ", %s", action->name);
 102
 103                 seq_putc(p, '\n');
 104 skip:
 105                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
 106         } else if (i == NR_IRQS) {
 107                 seq_putc(p, '\n');
 108                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 109         }
 110         return 0;
 111 }
 112
 113 asmlinkage void spurious_interrupt(struct pt_regs *regs)
 114 {
 115         atomic_inc(&irq_err_count);
 116 }
 117
 118 #ifdef CONFIG_KGDB
 119 extern void breakpoint(void);
 120 extern void set_debug_traps(void);
 121
 122 static int kgdb_flag = 1;
 123 static int __init nokgdb(char *str)
 124 {
 125         kgdb_flag = 0;
 126         return 1;
 127 }
 128 __setup("nokgdb", nokgdb);
 129 #endif
 130
 131 void __init init_IRQ(void)
 132 {
 133         int i;
 134
 135         for (i = 0; i < NR_IRQS; i++) {
 136                 irq_desc[i].status  = IRQ_DISABLED;
 137                 irq_desc[i].action  = NULL;
 138                 irq_desc[i].depth   = 1;
 139                 irq_desc[i].chip = &no_irq_chip;
 140                 spin_lock_init(&irq_desc[i].lock);
 141 #ifdef CONFIG_MIPS_MT_SMTC
 142                 irq_hwmask[i] = 0;
 143 #endif /* CONFIG_MIPS_MT_SMTC */
 144         }
 145
 146         arch_init_irq();
 147
 148 #ifdef CONFIG_KGDB
 149         if (kgdb_flag) {
 150                 printk("Wait for gdb client connection ...\n");
 151                 set_debug_traps();
 152                 breakpoint();
 153         }
 154 #endif
 155 }