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
120
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