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 static unsigned long irq_map[NR_IRQS / BITS_PER_LONG];
  30
  31 int allocate_irqno(void)
  32 {
  33         int irq;
  34
  35 again:
  36         irq = find_first_zero_bit(irq_map, NR_IRQS);
  37
  38         if (irq >= NR_IRQS)
  39                 return -ENOSPC;
  40
  41         if (test_and_set_bit(irq, irq_map))
  42                 goto again;
  43
  44         return irq;
  45 }
  46
  47 /*
  48  * Allocate the 16 legacy interrupts for i8259 devices.  This happens early
  49  * in the kernel initialization so treating allocation failure as BUG() is
  50  * ok.
  51  */
  52 void __init alloc_legacy_irqno(void)
  53 {
  54         int i;
  55
  56         for (i = 0; i <= 16; i++)
  57                 BUG_ON(test_and_set_bit(i, irq_map));
  58 }
  59
  60 void free_irqno(unsigned int irq)
  61 {
  62         smp_mb__before_clear_bit();
  63         clear_bit(irq, irq_map);
  64         smp_mb__after_clear_bit();
  65 }
  66
  67 /*
  68  * 'what should we do if we get a hw irq event on an illegal vector'.
  69  * each architecture has to answer this themselves.
  70  */
  71 void ack_bad_irq(unsigned int irq)
  72 {
  73         smtc_im_ack_irq(irq);
  74         printk("unexpected IRQ # %d\n", irq);
  75 }
  76
  77 atomic_t irq_err_count;
  78
  79 /*
  80  * Generic, controller-independent functions:
  81  */
  82
  83 int show_interrupts(struct seq_file *p, void *v)
  84 {
  85         int i = *(loff_t *) v, j;
  86         struct irqaction * action;
  87         unsigned long flags;
  88
  89         if (i == 0) {
  90                 seq_printf(p, "           ");
  91                 for_each_online_cpu(j)
  92                         seq_printf(p, "CPU%d       ", j);
  93                 seq_putc(p, '\n');
  94         }
  95
  96         if (i < NR_IRQS) {
  97                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  98                 action = irq_desc[i].action;
  99                 if (!action)
 100                         goto skip;
 101                 seq_printf(p, "%3d: ", i);
 102 #ifndef CONFIG_SMP
 103                 seq_printf(p, "%10u ", kstat_irqs(i));
 104 #else
 105                 for_each_online_cpu(j)
 106                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 107 #endif
 108                 seq_printf(p, " %14s", irq_desc[i].chip->name);
 109                 seq_printf(p, "  %s", action->name);
 110
 111                 for (action=action->next; action; action = action->next)
 112                         seq_printf(p, ", %s", action->name);
 113
 114                 seq_putc(p, '\n');
 115 skip:
 116                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
 117         } else if (i == NR_IRQS) {
 118                 seq_putc(p, '\n');
 119                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 120         }
 121         return 0;
 122 }
 123
 124 asmlinkage void spurious_interrupt(void)
 125 {
 126         atomic_inc(&irq_err_count);
 127 }
 128
 129 #ifdef CONFIG_KGDB
 130 extern void breakpoint(void);
 131 extern void set_debug_traps(void);
 132
 133 static int kgdb_flag = 1;
 134 static int __init nokgdb(char *str)
 135 {
 136         kgdb_flag = 0;
 137         return 1;
 138 }
 139 __setup("nokgdb", nokgdb);
 140 #endif
 141
 142 void __init init_IRQ(void)
 143 {
 144         int i;
 145
 146         for (i = 0; i < NR_IRQS; i++)
 147                 set_irq_noprobe(i);
 148
 149         arch_init_irq();
 150
 151 #ifdef CONFIG_KGDB
 152         if (kgdb_flag) {
 153                 printk("Wait for gdb client connection ...\n");
 154                 set_debug_traps();
 155                 breakpoint();
 156         }
 157 #endif
 158 }