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 #ifdef CONFIG_MIPS_MT_SMTC
  42 /*
  43  * SMTC Kernel needs to manipulate low-level CPU interrupt mask
  44  * in do_IRQ. These are passed in setup_irq_smtc() and stored
  45  * in this table.
  46  */
  47 unsigned long irq_hwmask[NR_IRQS];
  48 #endif /* CONFIG_MIPS_MT_SMTC */
  49
  50 #undef do_IRQ
  51
  52 /*
  53  * do_IRQ handles all normal device IRQ's (the special
  54  * SMP cross-CPU interrupts have their own specific
  55  * handlers).
  56  */
  57 asmlinkage unsigned int do_IRQ(unsigned int irq, struct pt_regs *regs)
  58 {
  59         irq_enter();
  60
  61         __DO_IRQ_SMTC_HOOK();
  62         __do_IRQ(irq, regs);
  63
  64         irq_exit();
  65
  66         return 1;
  67 }
  68
  69 /*
  70  * Generic, controller-independent functions:
  71  */
  72
  73 int show_interrupts(struct seq_file *p, void *v)
  74 {
  75         int i = *(loff_t *) v, j;
  76         struct irqaction * action;
  77         unsigned long flags;
  78
  79         if (i == 0) {
  80                 seq_printf(p, "           ");
  81                 for_each_online_cpu(j)
  82                         seq_printf(p, "CPU%d       ",j);
  83                 seq_putc(p, '\n');
  84         }
  85
  86         if (i < NR_IRQS) {
  87                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  88                 action = irq_desc[i].action;
  89                 if (!action)
  90                         goto skip;
  91                 seq_printf(p, "%3d: ",i);
  92 #ifndef CONFIG_SMP
  93                 seq_printf(p, "%10u ", kstat_irqs(i));
  94 #else
  95                 for_each_online_cpu(j)
  96                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  97 #endif
  98                 seq_printf(p, " %14s", irq_desc[i].handler->typename);
  99                 seq_printf(p, "  %s", action->name);
 100
 101                 for (action=action->next; action; action = action->next)
 102                         seq_printf(p, ", %s", action->name);
 103
 104                 seq_putc(p, '\n');
 105 skip:
 106                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
 107         } else if (i == NR_IRQS) {
 108                 seq_putc(p, '\n');
 109                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 110         }
 111         return 0;
 112 }
 113
 114 asmlinkage void spurious_interrupt(struct pt_regs *regs)
 115 {
 116         atomic_inc(&irq_err_count);
 117 }
 118
 119 #ifdef CONFIG_KGDB
 120 extern void breakpoint(void);
 121 extern void set_debug_traps(void);
 122
 123 static int kgdb_flag = 1;
 124 static int __init nokgdb(char *str)
 125 {
 126         kgdb_flag = 0;
 127         return 1;
 128 }
 129 __setup("nokgdb", nokgdb);
 130 #endif
 131
 132 void __init init_IRQ(void)
 133 {
 134         int i;
 135
 136         for (i = 0; i < NR_IRQS; i++) {
 137                 irq_desc[i].status  = IRQ_DISABLED;
 138                 irq_desc[i].action  = NULL;
 139                 irq_desc[i].depth   = 1;
 140                 irq_desc[i].handler = &no_irq_type;
 141                 spin_lock_init(&irq_desc[i].lock);
 142 #ifdef CONFIG_MIPS_MT_SMTC
 143                 irq_hwmask[i] = 0;
 144 #endif /* CONFIG_MIPS_MT_SMTC */
 145         }
 146
 147         arch_init_irq();
 148
 149 #ifdef CONFIG_KGDB
 150         if (kgdb_flag) {
 151                 printk("Wait for gdb client connection ...\n");
 152                 set_debug_traps();
 153                 breakpoint();
 154         }
 155 #endif
 156 }