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
  29 void *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  */
  35 void ack_bad_irq(unsigned int irq)
  36 {
  37         printk("unexpected IRQ # %d\n", irq);
  38 }
  39
  40 atomic_t irq_err_count;
  41
  42 int 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
  48 asmlinkage void spurious_interrupt(void)
  49 {
  50         atomic_inc(&irq_err_count);
  51 }
  52
  53 void __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
  76 static 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
  94 static 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  */
 103 void __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
 112 void __irq_entry do_domain_IRQ(struct irq_domain *domain, unsigned int hwirq)
 113 {
 114         irq_enter();
 115         check_stack_overflow();
 116         generic_handle_domain_irq(domain, hwirq);
 117         irq_exit();
 118 }
 119 #endif