1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006, Thomas Gleixner
6 * This file contains the IRQ-resend code
8 * If the interrupt is waiting to be processed, we try to re-run it.
9 * We can't directly run it from here since the caller might be in an
10 * interrupt-protected region. Not all irq controller chips can
11 * retrigger interrupts at the hardware level, so in those cases
12 * we allow the resending of IRQs via a tasklet.
15 #include <linux/irq.h>
16 #include <linux/module.h>
17 #include <linux/random.h>
18 #include <linux/interrupt.h>
20 #include "internals.h"
22 #ifdef CONFIG_HARDIRQS_SW_RESEND
24 /* Bitmap to handle software resend of interrupts: */
25 static DECLARE_BITMAP(irqs_resend, IRQ_BITMAP_BITS);
28 * Run software resends of IRQ's
30 static void resend_irqs(unsigned long arg)
32 struct irq_desc *desc;
35 while (!bitmap_empty(irqs_resend, nr_irqs)) {
36 irq = find_first_bit(irqs_resend, nr_irqs);
37 clear_bit(irq, irqs_resend);
38 desc = irq_to_desc(irq);
42 desc->handle_irq(desc);
47 /* Tasklet to handle resend: */
48 static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
55 * Is called with interrupts disabled and desc->lock held.
57 void check_irq_resend(struct irq_desc *desc)
60 * We do not resend level type interrupts. Level type
61 * interrupts are resent by hardware when they are still
62 * active. Clear the pending bit so suspend/resume does not
65 if (irq_settings_is_level(desc)) {
66 desc->istate &= ~IRQS_PENDING;
69 if (desc->istate & IRQS_REPLAY)
71 if (desc->istate & IRQS_PENDING) {
72 desc->istate &= ~IRQS_PENDING;
73 desc->istate |= IRQS_REPLAY;
75 if (!desc->irq_data.chip->irq_retrigger ||
76 !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) {
77 #ifdef CONFIG_HARDIRQS_SW_RESEND
78 unsigned int irq = irq_desc_get_irq(desc);
81 * If the interrupt is running in the thread
82 * context of the parent irq we need to be
83 * careful, because we cannot trigger it
86 if (irq_settings_is_nested_thread(desc)) {
88 * If the parent_irq is valid, we
89 * retrigger the parent, otherwise we
92 if (!desc->parent_irq)
94 irq = desc->parent_irq;
96 /* Set it pending and activate the softirq: */
97 set_bit(irq, irqs_resend);
98 tasklet_schedule(&resend_tasklet);