Commit | Line | Data |
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1da177e4 LT |
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 | */ | |
1da177e4 LT |
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> | |
1da177e4 | 16 | #include <linux/proc_fs.h> |
1da177e4 LT |
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> | |
88547001 | 22 | #include <linux/kgdb.h> |
8f99a162 | 23 | #include <linux/ftrace.h> |
1da177e4 | 24 | |
60063497 | 25 | #include <linux/atomic.h> |
1da177e4 LT |
26 | #include <asm/uaccess.h> |
27 | ||
884e7e5e | 28 | static DECLARE_BITMAP(irq_map, NR_IRQS); |
4a4cf779 | 29 | |
f543110d | 30 | int allocate_irqno(void) |
4a4cf779 RB |
31 | { |
32 | int irq; | |
33 | ||
34 | again: | |
35 | irq = find_first_zero_bit(irq_map, NR_IRQS); | |
36 | ||
37 | if (irq >= NR_IRQS) | |
38 | return -ENOSPC; | |
39 | ||
40 | if (test_and_set_bit(irq, irq_map)) | |
41 | goto again; | |
42 | ||
43 | return irq; | |
44 | } | |
45 | ||
4a4cf779 | 46 | /* |
70342287 | 47 | * Allocate the 16 legacy interrupts for i8259 devices. This happens early |
4a4cf779 RB |
48 | * in the kernel initialization so treating allocation failure as BUG() is |
49 | * ok. | |
50 | */ | |
51 | void __init alloc_legacy_irqno(void) | |
52 | { | |
53 | int i; | |
54 | ||
55 | for (i = 0; i <= 16; i++) | |
56 | BUG_ON(test_and_set_bit(i, irq_map)); | |
57 | } | |
58 | ||
f543110d | 59 | void free_irqno(unsigned int irq) |
4a4cf779 | 60 | { |
91bbefe6 | 61 | smp_mb__before_atomic(); |
4a4cf779 | 62 | clear_bit(irq, irq_map); |
91bbefe6 | 63 | smp_mb__after_atomic(); |
4a4cf779 RB |
64 | } |
65 | ||
1da177e4 LT |
66 | /* |
67 | * 'what should we do if we get a hw irq event on an illegal vector'. | |
68 | * each architecture has to answer this themselves. | |
69 | */ | |
70 | void ack_bad_irq(unsigned int irq) | |
71 | { | |
72 | printk("unexpected IRQ # %d\n", irq); | |
73 | } | |
74 | ||
75 | atomic_t irq_err_count; | |
76 | ||
f8396c17 | 77 | int arch_show_interrupts(struct seq_file *p, int prec) |
1da177e4 | 78 | { |
f8396c17 | 79 | seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); |
1da177e4 LT |
80 | return 0; |
81 | } | |
82 | ||
937a8015 | 83 | asmlinkage void spurious_interrupt(void) |
93373ed4 RB |
84 | { |
85 | atomic_inc(&irq_err_count); | |
86 | } | |
87 | ||
1da177e4 LT |
88 | void __init init_IRQ(void) |
89 | { | |
24649c00 RB |
90 | int i; |
91 | ||
92 | for (i = 0; i < NR_IRQS; i++) | |
e4ec7989 | 93 | irq_set_noprobe(i); |
24649c00 | 94 | |
1da177e4 | 95 | arch_init_irq(); |
1da177e4 | 96 | } |
8f99a162 | 97 | |
5f35b9cd | 98 | #ifdef CONFIG_DEBUG_STACKOVERFLOW |
334c86c4 F |
99 | static inline void check_stack_overflow(void) |
100 | { | |
101 | unsigned long sp; | |
102 | ||
103 | __asm__ __volatile__("move %0, $sp" : "=r" (sp)); | |
104 | sp &= THREAD_MASK; | |
105 | ||
106 | /* | |
107 | * Check for stack overflow: is there less than STACK_WARN free? | |
108 | * STACK_WARN is defined as 1/8 of THREAD_SIZE by default. | |
109 | */ | |
110 | if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { | |
111 | printk("do_IRQ: stack overflow: %ld\n", | |
112 | sp - sizeof(struct thread_info)); | |
113 | dump_stack(); | |
114 | } | |
115 | } | |
116 | #else | |
117 | static inline void check_stack_overflow(void) {} | |
118 | #endif | |
119 | ||
120 | ||
8f99a162 WZ |
121 | /* |
122 | * do_IRQ handles all normal device IRQ's (the special | |
123 | * SMP cross-CPU interrupts have their own specific | |
124 | * handlers). | |
125 | */ | |
126 | void __irq_entry do_IRQ(unsigned int irq) | |
127 | { | |
128 | irq_enter(); | |
334c86c4 | 129 | check_stack_overflow(); |
8f99a162 WZ |
130 | generic_handle_irq(irq); |
131 | irq_exit(); | |
132 | } | |
133 |