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
  25 #include <linux/atomic.h>
  26 #include <linux/uaccess.h>
  27
  28 /*
  29  * 'what should we do if we get a hw irq event on an illegal vector'.
  30  * each architecture has to answer this themselves.
  31  */
  32 void ack_bad_irq(unsigned int irq)
  33 {
  34         printk("unexpected IRQ # %d\n", irq);
  35 }
  36
  37 atomic_t irq_err_count;
  38
  39 int arch_show_interrupts(struct seq_file *p, int prec)
  40 {
  41         seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
  42         return 0;
  43 }
  44
  45 asmlinkage void spurious_interrupt(void)
  46 {
  47         atomic_inc(&irq_err_count);
  48 }
  49
  50 void __init init_IRQ(void)
  51 {
  52         int i;
  53
  54         for (i = 0; i < NR_IRQS; i++)
  55                 irq_set_noprobe(i);
  56
  57         if (cpu_has_veic)
  58                 clear_c0_status(ST0_IM);
  59
  60         arch_init_irq();
  61 }
  62
  63 #ifdef CONFIG_DEBUG_STACKOVERFLOW
  64 static inline void check_stack_overflow(void)
  65 {
  66         unsigned long sp;
  67
  68         __asm__ __volatile__("move %0, $sp" : "=r" (sp));
  69         sp &= THREAD_MASK;
  70
  71         /*
  72          * Check for stack overflow: is there less than STACK_WARN free?
  73          * STACK_WARN is defined as 1/8 of THREAD_SIZE by default.
  74          */
  75         if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
  76                 printk("do_IRQ: stack overflow: %ld\n",
  77                        sp - sizeof(struct thread_info));
  78                 dump_stack();
  79         }
  80 }
  81 #else
  82 static inline void check_stack_overflow(void) {}
  83 #endif
  84
  85
  86 /*
  87  * do_IRQ handles all normal device IRQ's (the special
  88  * SMP cross-CPU interrupts have their own specific
  89  * handlers).
  90  */
  91 void __irq_entry do_IRQ(unsigned int irq)
  92 {
  93         irq_enter();
  94         check_stack_overflow();
  95         generic_handle_irq(irq);
  96         irq_exit();
  97 }
  98