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/proc_fs.h>
  17#include <linux/mm.h>
  18#include <linux/random.h>
  19#include <linux/sched.h>
  20#include <linux/seq_file.h>
  21#include <linux/kallsyms.h>
  22#include <linux/kgdb.h>
  23#include <linux/ftrace.h>
  24#include <linux/irqdomain.h>
  25
  26#include <linux/atomic.h>
  27#include <linux/uaccess.h>
  28
  29void *irq_stack[NR_CPUS];
  30
  31/*
  32 * 'what should we do if we get a hw irq event on an illegal vector'.
  33 * each architecture has to answer this themselves.
  34 */
  35void ack_bad_irq(unsigned int irq)
  36{
  37        printk("unexpected IRQ # %d\n", irq);
  38}
  39
  40atomic_t irq_err_count;
  41
  42int arch_show_interrupts(struct seq_file *p, int prec)
  43{
  44        seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
  45        return 0;
  46}
  47
  48asmlinkage void spurious_interrupt(void)
  49{
  50        atomic_inc(&irq_err_count);
  51}
  52
  53void __init init_IRQ(void)
  54{
  55        int i;
  56        unsigned int order = get_order(IRQ_STACK_SIZE);
  57
  58        for (i = 0; i < NR_IRQS; i++)
  59                irq_set_noprobe(i);
  60
  61        if (cpu_has_veic)
  62                clear_c0_status(ST0_IM);
  63
  64        arch_init_irq();
  65
  66        for_each_possible_cpu(i) {
  67                void *s = (void *)__get_free_pages(GFP_KERNEL, order);
  68
  69                irq_stack[i] = s;
  70                pr_debug("CPU%d IRQ stack at 0x%p - 0x%p\n", i,
  71                        irq_stack[i], irq_stack[i] + IRQ_STACK_SIZE);
  72        }
  73}
  74
  75#ifdef CONFIG_DEBUG_STACKOVERFLOW
  76static inline void check_stack_overflow(void)
  77{
  78        unsigned long sp;
  79
  80        __asm__ __volatile__("move %0, $sp" : "=r" (sp));
  81        sp &= THREAD_MASK;
  82
  83        /*
  84         * Check for stack overflow: is there less than STACK_WARN free?
  85         * STACK_WARN is defined as 1/8 of THREAD_SIZE by default.
  86         */
  87        if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
  88                printk("do_IRQ: stack overflow: %ld\n",
  89                       sp - sizeof(struct thread_info));
  90                dump_stack();
  91        }
  92}
  93#else
  94static inline void check_stack_overflow(void) {}
  95#endif
  96
  97
  98/*
  99 * do_IRQ handles all normal device IRQ's (the special
 100 * SMP cross-CPU interrupts have their own specific
 101 * handlers).
 102 */
 103void __irq_entry do_IRQ(unsigned int irq)
 104{
 105        irq_enter();
 106        check_stack_overflow();
 107        generic_handle_irq(irq);
 108        irq_exit();
 109}
 110
 111#ifdef CONFIG_IRQ_DOMAIN
 112void __irq_entry do_domain_IRQ(struct irq_domain *domain, unsigned int hwirq)
 113{
 114        struct irq_desc *desc;
 115
 116        irq_enter();
 117        check_stack_overflow();
 118
 119        desc = irq_resolve_mapping(domain, hwirq);
 120        if (likely(desc))
 121                handle_irq_desc(desc);
 122
 123        irq_exit();
 124}
 125#endif
 126