LXR linux/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#include <linux/kgdb.h>
  25
  26#include <asm/atomic.h>
  27#include <asm/system.h>
  28#include <asm/uaccess.h>
  29
  30#ifdef CONFIG_KGDB
  31int kgdb_early_setup;
  32#endif
  33
  34static unsigned long irq_map[NR_IRQS / BITS_PER_LONG];
  35
  36int allocate_irqno(void)
  37{
  38        int irq;
  39
  40again:
  41        irq = find_first_zero_bit(irq_map, NR_IRQS);
  42
  43        if (irq >= NR_IRQS)
  44                return -ENOSPC;
  45
  46        if (test_and_set_bit(irq, irq_map))
  47                goto again;
  48
  49        return irq;
  50}
  51
  52/*
  53 * Allocate the 16 legacy interrupts for i8259 devices.  This happens early
  54 * in the kernel initialization so treating allocation failure as BUG() is
  55 * ok.
  56 */
  57void __init alloc_legacy_irqno(void)
  58{
  59        int i;
  60
  61        for (i = 0; i <= 16; i++)
  62                BUG_ON(test_and_set_bit(i, irq_map));
  63}
  64
  65void free_irqno(unsigned int irq)
  66{
  67        smp_mb__before_clear_bit();
  68        clear_bit(irq, irq_map);
  69        smp_mb__after_clear_bit();
  70}
  71
  72/*
  73 * 'what should we do if we get a hw irq event on an illegal vector'.
  74 * each architecture has to answer this themselves.
  75 */
  76void ack_bad_irq(unsigned int irq)
  77{
  78        smtc_im_ack_irq(irq);
  79        printk("unexpected IRQ # %d\n", irq);
  80}
  81
  82atomic_t irq_err_count;
  83
  84/*
  85 * Generic, controller-independent functions:
  86 */
  87
  88int show_interrupts(struct seq_file *p, void *v)
  89{
  90        int i = *(loff_t *) v, j;
  91        struct irqaction * action;
  92        unsigned long flags;
  93
  94        if (i == 0) {
  95                seq_printf(p, "           ");
  96                for_each_online_cpu(j)
  97                        seq_printf(p, "CPU%d       ", j);
  98                seq_putc(p, '\n');
  99        }
 100
 101        if (i < NR_IRQS) {
 102                spin_lock_irqsave(&irq_desc[i].lock, flags);
 103                action = irq_desc[i].action;
 104                if (!action)
 105                        goto skip;
 106                seq_printf(p, "%3d: ", i);
 107#ifndef CONFIG_SMP
 108                seq_printf(p, "%10u ", kstat_irqs(i));
 109#else
 110                for_each_online_cpu(j)
 111                        seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 112#endif
 113                seq_printf(p, " %14s", irq_desc[i].chip->name);
 114                seq_printf(p, "  %s", action->name);
 115
 116                for (action=action->next; action; action = action->next)
 117                        seq_printf(p, ", %s", action->name);
 118
 119                seq_putc(p, '\n');
 120skip:
 121                spin_unlock_irqrestore(&irq_desc[i].lock, flags);
 122        } else if (i == NR_IRQS) {
 123                seq_putc(p, '\n');
 124                seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 125        }
 126        return 0;
 127}
 128
 129asmlinkage void spurious_interrupt(void)
 130{
 131        atomic_inc(&irq_err_count);
 132}
 133
 134void __init init_IRQ(void)
 135{
 136        int i;
 137
 138#ifdef CONFIG_KGDB
 139        if (kgdb_early_setup)
 140                return;
 141#endif
 142
 143        for (i = 0; i < NR_IRQS; i++)
 144                set_irq_noprobe(i);
 145
 146        arch_init_irq();
 147
 148#ifdef CONFIG_KGDB
 149        if (!kgdb_early_setup)
 150                kgdb_early_setup = 1;
 151#endif
 152}
 153