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