2 * linux/kernel/irq/resend.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006, Thomas Gleixner
7 * This file contains the IRQ-resend code
9 * If the interrupt is waiting to be processed, we try to re-run it.
10 * We can't directly run it from here since the caller might be in an
11 * interrupt-protected region. Not all irq controller chips can
12 * retrigger interrupts at the hardware level, so in those cases
13 * we allow the resending of IRQs via a tasklet.
16 #include <linux/irq.h>
17 #include <linux/module.h>
18 #include <linux/random.h>
19 #include <linux/interrupt.h>
21 #include "internals.h"
23 #ifdef CONFIG_HARDIRQS_SW_RESEND
25 /* Bitmap to handle software resend of interrupts: */
26 static DECLARE_BITMAP(irqs_resend
, IRQ_BITMAP_BITS
);
29 * Run software resends of IRQ's
31 static void resend_irqs(unsigned long arg
)
33 struct irq_desc
*desc
;
36 while (!bitmap_empty(irqs_resend
, nr_irqs
)) {
37 irq
= find_first_bit(irqs_resend
, nr_irqs
);
38 clear_bit(irq
, irqs_resend
);
39 desc
= irq_to_desc(irq
);
41 desc
->handle_irq(desc
);
46 /* Tasklet to handle resend: */
47 static DECLARE_TASKLET(resend_tasklet
, resend_irqs
, 0);
54 * Is called with interrupts disabled and desc->lock held.
56 void check_irq_resend(struct irq_desc
*desc
)
59 * We do not resend level type interrupts. Level type
60 * interrupts are resent by hardware when they are still
61 * active. Clear the pending bit so suspend/resume does not
64 if (irq_settings_is_level(desc
)) {
65 desc
->istate
&= ~IRQS_PENDING
;
68 if (desc
->istate
& IRQS_REPLAY
)
70 if (desc
->istate
& IRQS_PENDING
) {
71 desc
->istate
&= ~IRQS_PENDING
;
72 desc
->istate
|= IRQS_REPLAY
;
74 if (!desc
->irq_data
.chip
->irq_retrigger
||
75 !desc
->irq_data
.chip
->irq_retrigger(&desc
->irq_data
)) {
76 #ifdef CONFIG_HARDIRQS_SW_RESEND
77 unsigned int irq
= irq_desc_get_irq(desc
);
80 * If the interrupt is running in the thread
81 * context of the parent irq we need to be
82 * careful, because we cannot trigger it
85 if (irq_settings_is_nested_thread(desc
)) {
87 * If the parent_irq is valid, we
88 * retrigger the parent, otherwise we
91 if (!desc
->parent_irq
)
93 irq
= desc
->parent_irq
;
95 /* Set it pending and activate the softirq: */
96 set_bit(irq
, irqs_resend
);
97 tasklet_schedule(&resend_tasklet
);
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