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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> | |
16 | #include <linux/module.h> | |
17 | #include <linux/proc_fs.h> | |
1da177e4 LT |
18 | #include <linux/mm.h> |
19 | #include <linux/random.h> | |
20 | #include <linux/sched.h> | |
21 | #include <linux/seq_file.h> | |
22 | #include <linux/kallsyms.h> | |
88547001 | 23 | #include <linux/kgdb.h> |
8f99a162 | 24 | #include <linux/ftrace.h> |
1da177e4 LT |
25 | |
26 | #include <asm/atomic.h> | |
27 | #include <asm/system.h> | |
28 | #include <asm/uaccess.h> | |
29 | ||
88547001 JW |
30 | #ifdef CONFIG_KGDB |
31 | int kgdb_early_setup; | |
32 | #endif | |
33 | ||
4a4cf779 RB |
34 | static unsigned long irq_map[NR_IRQS / BITS_PER_LONG]; |
35 | ||
f543110d | 36 | int allocate_irqno(void) |
4a4cf779 RB |
37 | { |
38 | int irq; | |
39 | ||
40 | again: | |
41 | irq = find_first_zero_bit(irq_map, NR_IRQS); | |
42 | ||
43 | if (irq >= NR_IRQS) | |
44 | return -ENOSPC; | |
45 | ||
46 | if (test_and_set_bit(irq, irq_map)) | |
47 | goto again; | |
48 | ||
49 | return irq; | |
50 | } | |
51 | ||
4a4cf779 RB |
52 | /* |
53 | * Allocate the 16 legacy interrupts for i8259 devices. This happens early | |
54 | * in the kernel initialization so treating allocation failure as BUG() is | |
55 | * ok. | |
56 | */ | |
57 | void __init alloc_legacy_irqno(void) | |
58 | { | |
59 | int i; | |
60 | ||
61 | for (i = 0; i <= 16; i++) | |
62 | BUG_ON(test_and_set_bit(i, irq_map)); | |
63 | } | |
64 | ||
f543110d | 65 | void free_irqno(unsigned int irq) |
4a4cf779 RB |
66 | { |
67 | smp_mb__before_clear_bit(); | |
68 | clear_bit(irq, irq_map); | |
69 | smp_mb__after_clear_bit(); | |
70 | } | |
71 | ||
1da177e4 LT |
72 | /* |
73 | * 'what should we do if we get a hw irq event on an illegal vector'. | |
74 | * each architecture has to answer this themselves. | |
75 | */ | |
76 | void ack_bad_irq(unsigned int irq) | |
77 | { | |
1146fe30 | 78 | smtc_im_ack_irq(irq); |
1da177e4 LT |
79 | printk("unexpected IRQ # %d\n", irq); |
80 | } | |
81 | ||
82 | atomic_t irq_err_count; | |
83 | ||
f8396c17 | 84 | int arch_show_interrupts(struct seq_file *p, int prec) |
1da177e4 | 85 | { |
f8396c17 | 86 | seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); |
1da177e4 LT |
87 | return 0; |
88 | } | |
89 | ||
937a8015 | 90 | asmlinkage void spurious_interrupt(void) |
93373ed4 RB |
91 | { |
92 | atomic_inc(&irq_err_count); | |
93 | } | |
94 | ||
1da177e4 LT |
95 | void __init init_IRQ(void) |
96 | { | |
24649c00 RB |
97 | int i; |
98 | ||
88547001 JW |
99 | #ifdef CONFIG_KGDB |
100 | if (kgdb_early_setup) | |
101 | return; | |
102 | #endif | |
103 | ||
24649c00 | 104 | for (i = 0; i < NR_IRQS; i++) |
e4ec7989 | 105 | irq_set_noprobe(i); |
24649c00 | 106 | |
1da177e4 | 107 | arch_init_irq(); |
88547001 JW |
108 | |
109 | #ifdef CONFIG_KGDB | |
110 | if (!kgdb_early_setup) | |
111 | kgdb_early_setup = 1; | |
112 | #endif | |
1da177e4 | 113 | } |
8f99a162 | 114 | |
334c86c4 F |
115 | #ifdef DEBUG_STACKOVERFLOW |
116 | static inline void check_stack_overflow(void) | |
117 | { | |
118 | unsigned long sp; | |
119 | ||
120 | __asm__ __volatile__("move %0, $sp" : "=r" (sp)); | |
121 | sp &= THREAD_MASK; | |
122 | ||
123 | /* | |
124 | * Check for stack overflow: is there less than STACK_WARN free? | |
125 | * STACK_WARN is defined as 1/8 of THREAD_SIZE by default. | |
126 | */ | |
127 | if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { | |
128 | printk("do_IRQ: stack overflow: %ld\n", | |
129 | sp - sizeof(struct thread_info)); | |
130 | dump_stack(); | |
131 | } | |
132 | } | |
133 | #else | |
134 | static inline void check_stack_overflow(void) {} | |
135 | #endif | |
136 | ||
137 | ||
8f99a162 WZ |
138 | /* |
139 | * do_IRQ handles all normal device IRQ's (the special | |
140 | * SMP cross-CPU interrupts have their own specific | |
141 | * handlers). | |
142 | */ | |
143 | void __irq_entry do_IRQ(unsigned int irq) | |
144 | { | |
145 | irq_enter(); | |
334c86c4 | 146 | check_stack_overflow(); |
930cd54b TG |
147 | if (!smtc_handle_on_other_cpu(irq)) |
148 | generic_handle_irq(irq); | |
8f99a162 WZ |
149 | irq_exit(); |
150 | } | |
151 | ||
152 | #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF | |
153 | /* | |
154 | * To avoid inefficient and in some cases pathological re-checking of | |
155 | * IRQ affinity, we have this variant that skips the affinity check. | |
156 | */ | |
157 | ||
158 | void __irq_entry do_IRQ_no_affinity(unsigned int irq) | |
159 | { | |
160 | irq_enter(); | |
930cd54b | 161 | smtc_im_backstop(irq); |
8f99a162 WZ |
162 | generic_handle_irq(irq); |
163 | irq_exit(); | |
164 | } | |
165 | ||
166 | #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */ |