1// SPDX-License-Identifier: GPL-2.0
  2/*
 
 
  3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
  4 * Copyright (C) 2005-2006, Thomas Gleixner
  5 *
  6 * This file contains the IRQ-resend code
  7 *
  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.
 13 */
 14
 15#include <linux/irq.h>
 16#include <linux/module.h>
 17#include <linux/random.h>
 18#include <linux/interrupt.h>
 19
 20#include "internals.h"
 21
 22#ifdef CONFIG_HARDIRQS_SW_RESEND
 23
 24/* Bitmap to handle software resend of interrupts: */
 25static DECLARE_BITMAP(irqs_resend, IRQ_BITMAP_BITS);
 26
 27/*
 28 * Run software resends of IRQ's
 29 */
 30static void resend_irqs(unsigned long arg)
 31{
 32	struct irq_desc *desc;
 33	int irq;
 34
 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);
 39		if (!desc)
 40			continue;
 41		local_irq_disable();
 42		desc->handle_irq(desc);
 43		local_irq_enable();
 44	}
 45}
 46
 47/* Tasklet to handle resend: */
 48static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
 49
 50#endif
 51
 52/*
 53 * IRQ resend
 54 *
 55 * Is called with interrupts disabled and desc->lock held.
 56 */
 57void check_irq_resend(struct irq_desc *desc)
 58{
 59	/*
 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
 63	 * get confused.
 64	 */
 65	if (irq_settings_is_level(desc)) {
 66		desc->istate &= ~IRQS_PENDING;
 67		return;
 68	}
 69	if (desc->istate & IRQS_REPLAY)
 70		return;
 71	if (desc->istate & IRQS_PENDING) {
 72		desc->istate &= ~IRQS_PENDING;
 73		desc->istate |= IRQS_REPLAY;
 74
 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);
 79
 80			/*
 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
 84			 * directly.
 85			 */
 86			if (irq_settings_is_nested_thread(desc)) {
 87				/*
 88				 * If the parent_irq is valid, we
 89				 * retrigger the parent, otherwise we
 90				 * do nothing.
 91				 */
 92				if (!desc->parent_irq)
 93					return;
 94				irq = desc->parent_irq;
 95			}
 96			/* Set it pending and activate the softirq: */
 97			set_bit(irq, irqs_resend);
 98			tasklet_schedule(&resend_tasklet);
 99#endif
100		}
101	}
102}

 
 1/*
 2 * linux/kernel/irq/resend.c
 3 *
 4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
 5 * Copyright (C) 2005-2006, Thomas Gleixner
 6 *
 7 * This file contains the IRQ-resend code
 8 *
 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.
14 */
15
16#include <linux/irq.h>
17#include <linux/module.h>
18#include <linux/random.h>
19#include <linux/interrupt.h>
20
21#include "internals.h"
22
23#ifdef CONFIG_HARDIRQS_SW_RESEND
24
25/* Bitmap to handle software resend of interrupts: */
26static DECLARE_BITMAP(irqs_resend, IRQ_BITMAP_BITS);
27
28/*
29 * Run software resends of IRQ's
30 */
31static void resend_irqs(unsigned long arg)
32{
33	struct irq_desc *desc;
34	int irq;
35
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);
 
 
40		local_irq_disable();
41		desc->handle_irq(irq, desc);
42		local_irq_enable();
43	}
44}
45
46/* Tasklet to handle resend: */
47static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
48
49#endif
50
51/*
52 * IRQ resend
53 *
54 * Is called with interrupts disabled and desc->lock held.
55 */
56void check_irq_resend(struct irq_desc *desc, unsigned int irq)
57{
58	/*
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
62	 * get confused.
63	 */
64	if (irq_settings_is_level(desc)) {
65		desc->istate &= ~IRQS_PENDING;
66		return;
67	}
68	if (desc->istate & IRQS_REPLAY)
69		return;
70	if (desc->istate & IRQS_PENDING) {
71		desc->istate &= ~IRQS_PENDING;
72		desc->istate |= IRQS_REPLAY;
73
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			/* Set it pending and activate the softirq: */
78			set_bit(irq, irqs_resend);
79			tasklet_schedule(&resend_tasklet);
80#endif
81		}
82	}
83}