Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/irq/handle.c | |
3 | * | |
a34db9b2 IM |
4 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
5 | * Copyright (C) 2005-2006, Thomas Gleixner, Russell King | |
1da177e4 LT |
6 | * |
7 | * This file contains the core interrupt handling code. | |
a34db9b2 IM |
8 | * |
9 | * Detailed information is available in Documentation/DocBook/genericirq | |
10 | * | |
1da177e4 LT |
11 | */ |
12 | ||
13 | #include <linux/irq.h> | |
1da177e4 | 14 | #include <linux/random.h> |
3795de23 | 15 | #include <linux/sched.h> |
1da177e4 LT |
16 | #include <linux/interrupt.h> |
17 | #include <linux/kernel_stat.h> | |
3795de23 | 18 | |
ad8d75ff | 19 | #include <trace/events/irq.h> |
1da177e4 LT |
20 | |
21 | #include "internals.h" | |
22 | ||
6a6de9ef TG |
23 | /** |
24 | * handle_bad_irq - handle spurious and unhandled irqs | |
43a1dd50 HK |
25 | * @irq: the interrupt number |
26 | * @desc: description of the interrupt | |
43a1dd50 HK |
27 | * |
28 | * Handles spurious and unhandled IRQ's. It also prints a debugmessage. | |
6a6de9ef | 29 | */ |
d6c88a50 | 30 | void handle_bad_irq(unsigned int irq, struct irq_desc *desc) |
6a6de9ef | 31 | { |
43f77759 | 32 | print_irq_desc(irq, desc); |
d6c88a50 | 33 | kstat_incr_irqs_this_cpu(irq, desc); |
6a6de9ef TG |
34 | ack_bad_irq(irq); |
35 | } | |
36 | ||
1da177e4 LT |
37 | /* |
38 | * Special, empty irq handler: | |
39 | */ | |
7d12e780 | 40 | irqreturn_t no_action(int cpl, void *dev_id) |
1da177e4 LT |
41 | { |
42 | return IRQ_NONE; | |
43 | } | |
44 | ||
f48fe81e TG |
45 | static void warn_no_thread(unsigned int irq, struct irqaction *action) |
46 | { | |
47 | if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags)) | |
48 | return; | |
49 | ||
50 | printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD " | |
51 | "but no thread function available.", irq, action->name); | |
52 | } | |
53 | ||
1277a532 TG |
54 | irqreturn_t |
55 | handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action) | |
1da177e4 | 56 | { |
908dcecd | 57 | irqreturn_t ret, retval = IRQ_NONE; |
f9e4989e | 58 | unsigned int random = 0, irq = desc->irq_data.irq; |
1da177e4 | 59 | |
1da177e4 | 60 | do { |
af39241b | 61 | trace_irq_handler_entry(irq, action); |
7d12e780 | 62 | ret = action->handler(irq, action->dev_id); |
af39241b | 63 | trace_irq_handler_exit(irq, action, ret); |
3aa551c9 | 64 | |
b738a50a TG |
65 | if (WARN_ON_ONCE(!irqs_disabled())) |
66 | local_irq_disable(); | |
67 | ||
3aa551c9 TG |
68 | switch (ret) { |
69 | case IRQ_WAKE_THREAD: | |
f48fe81e TG |
70 | /* |
71 | * Set result to handled so the spurious check | |
72 | * does not trigger. | |
73 | */ | |
74 | ret = IRQ_HANDLED; | |
75 | ||
76 | /* | |
77 | * Catch drivers which return WAKE_THREAD but | |
78 | * did not set up a thread function | |
79 | */ | |
80 | if (unlikely(!action->thread_fn)) { | |
81 | warn_no_thread(irq, action); | |
82 | break; | |
83 | } | |
84 | ||
3aa551c9 TG |
85 | /* |
86 | * Wake up the handler thread for this | |
87 | * action. In case the thread crashed and was | |
88 | * killed we just pretend that we handled the | |
89 | * interrupt. The hardirq handler above has | |
90 | * disabled the device interrupt, so no irq | |
91 | * storm is lurking. | |
92 | */ | |
93 | if (likely(!test_bit(IRQTF_DIED, | |
94 | &action->thread_flags))) { | |
95 | set_bit(IRQTF_RUNTHREAD, &action->thread_flags); | |
96 | wake_up_process(action->thread); | |
97 | } | |
98 | ||
3aa551c9 TG |
99 | /* Fall through to add to randomness */ |
100 | case IRQ_HANDLED: | |
f9e4989e | 101 | random |= action->flags; |
3aa551c9 TG |
102 | break; |
103 | ||
104 | default: | |
105 | break; | |
106 | } | |
107 | ||
1da177e4 LT |
108 | retval |= ret; |
109 | action = action->next; | |
110 | } while (action); | |
111 | ||
f9e4989e | 112 | if (random & IRQF_SAMPLE_RANDOM) |
1da177e4 | 113 | add_interrupt_randomness(irq); |
1da177e4 | 114 | |
4912609f | 115 | if (!noirqdebug) |
1277a532 TG |
116 | note_interrupt(irq, desc, ret); |
117 | return retval; | |
4912609f TG |
118 | } |
119 | ||
120 | irqreturn_t handle_irq_event(struct irq_desc *desc) | |
121 | { | |
122 | struct irqaction *action = desc->action; | |
123 | irqreturn_t ret; | |
124 | ||
2a0d6fb3 TG |
125 | irq_compat_clr_pending(desc); |
126 | desc->istate &= ~IRQS_PENDING; | |
009b4c3b TG |
127 | irq_compat_set_progress(desc); |
128 | desc->istate |= IRQS_INPROGRESS; | |
4912609f TG |
129 | raw_spin_unlock(&desc->lock); |
130 | ||
131 | ret = handle_irq_event_percpu(desc, action); | |
132 | ||
133 | raw_spin_lock(&desc->lock); | |
009b4c3b TG |
134 | desc->istate &= ~IRQS_INPROGRESS; |
135 | irq_compat_clr_progress(desc); | |
4912609f TG |
136 | return ret; |
137 | } | |
138 | ||
139 | /** | |
140 | * handle_IRQ_event - irq action chain handler | |
141 | * @irq: the interrupt number | |
142 | * @action: the interrupt action chain for this irq | |
143 | * | |
144 | * Handles the action chain of an irq event | |
145 | */ | |
146 | irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action) | |
147 | { | |
1277a532 | 148 | return handle_irq_event_percpu(irq_to_desc(irq), action); |
4912609f | 149 | } |