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);
43 desc->handle_irq(desc);
48 /* Tasklet to handle resend: */
49 static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
56 * Is called with interrupts disabled and desc->lock held.
58 void check_irq_resend(struct irq_desc *desc)
61 * We do not resend level type interrupts. Level type
62 * interrupts are resent by hardware when they are still
63 * active. Clear the pending bit so suspend/resume does not
66 if (irq_settings_is_level(desc)) {
67 desc->istate &= ~IRQS_PENDING;
70 if (desc->istate & IRQS_REPLAY)
72 if (desc->istate & IRQS_PENDING) {
73 desc->istate &= ~IRQS_PENDING;
74 desc->istate |= IRQS_REPLAY;
76 if (!desc->irq_data.chip->irq_retrigger ||
77 !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) {
78 #ifdef CONFIG_HARDIRQS_SW_RESEND
79 unsigned int irq = irq_desc_get_irq(desc);
82 * If the interrupt is running in the thread
83 * context of the parent irq we need to be
84 * careful, because we cannot trigger it
87 if (irq_settings_is_nested_thread(desc)) {
89 * If the parent_irq is valid, we
90 * retrigger the parent, otherwise we
93 if (!desc->parent_irq)
95 irq = desc->parent_irq;
97 /* Set it pending and activate the softirq: */
98 set_bit(irq, irqs_resend);
99 tasklet_schedule(&resend_tasklet);