genirq: Provide forced interrupt threading
[linux-2.6.git] / kernel / irq / pm.c
1 /*
2  * linux/kernel/irq/pm.c
3  *
4  * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
5  *
6  * This file contains power management functions related to interrupts.
7  */
8
9 #include <linux/irq.h>
10 #include <linux/module.h>
11 #include <linux/interrupt.h>
12
13 #include "internals.h"
14
15 /**
16  * suspend_device_irqs - disable all currently enabled interrupt lines
17  *
18  * During system-wide suspend or hibernation device drivers need to be prevented
19  * from receiving interrupts and this function is provided for this purpose.
20  * It marks all interrupt lines in use, except for the timer ones, as disabled
21  * and sets the IRQS_SUSPENDED flag for each of them.
22  */
23 void suspend_device_irqs(void)
24 {
25         struct irq_desc *desc;
26         int irq;
27
28         for_each_irq_desc(irq, desc) {
29                 unsigned long flags;
30
31                 raw_spin_lock_irqsave(&desc->lock, flags);
32                 __disable_irq(desc, irq, true);
33                 raw_spin_unlock_irqrestore(&desc->lock, flags);
34         }
35
36         for_each_irq_desc(irq, desc)
37                 if (desc->istate & IRQS_SUSPENDED)
38                         synchronize_irq(irq);
39 }
40 EXPORT_SYMBOL_GPL(suspend_device_irqs);
41
42 /**
43  * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()
44  *
45  * Enable all interrupt lines previously disabled by suspend_device_irqs() that
46  * have the IRQS_SUSPENDED flag set.
47  */
48 void resume_device_irqs(void)
49 {
50         struct irq_desc *desc;
51         int irq;
52
53         for_each_irq_desc(irq, desc) {
54                 unsigned long flags;
55
56                 raw_spin_lock_irqsave(&desc->lock, flags);
57                 __enable_irq(desc, irq, true);
58                 raw_spin_unlock_irqrestore(&desc->lock, flags);
59         }
60 }
61 EXPORT_SYMBOL_GPL(resume_device_irqs);
62
63 /**
64  * check_wakeup_irqs - check if any wake-up interrupts are pending
65  */
66 int check_wakeup_irqs(void)
67 {
68         struct irq_desc *desc;
69         int irq;
70
71         for_each_irq_desc(irq, desc)
72                 if (irqd_is_wakeup_set(&desc->irq_data) &&
73                     (desc->istate & IRQS_PENDING))
74                         return -EBUSY;
75
76         return 0;
77 }