1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
4 *
5 * This file contains power management functions related to interrupts.
6 */
7
8#include <linux/irq.h>
9#include <linux/module.h>
10#include <linux/interrupt.h>
11#include <linux/suspend.h>
12#include <linux/syscore_ops.h>
13
14#include "internals.h"
15
16bool irq_pm_check_wakeup(struct irq_desc *desc)
17{
18	if (irqd_is_wakeup_armed(&desc->irq_data)) {
19		irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
20		desc->istate |= IRQS_SUSPENDED | IRQS_PENDING;
21		desc->depth++;
22		irq_disable(desc);
23		pm_system_irq_wakeup(irq_desc_get_irq(desc));
24		return true;
25	}
26	return false;
27}
28
29/*
30 * Called from __setup_irq() with desc->lock held after @action has
31 * been installed in the action chain.
32 */
33void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action)
34{
35	desc->nr_actions++;
36
37	if (action->flags & IRQF_FORCE_RESUME)
38		desc->force_resume_depth++;
39
40	WARN_ON_ONCE(desc->force_resume_depth &&
41		     desc->force_resume_depth != desc->nr_actions);
42
43	if (action->flags & IRQF_NO_SUSPEND)
44		desc->no_suspend_depth++;
45	else if (action->flags & IRQF_COND_SUSPEND)
46		desc->cond_suspend_depth++;
47
48	WARN_ON_ONCE(desc->no_suspend_depth &&
49		     (desc->no_suspend_depth +
50			desc->cond_suspend_depth) != desc->nr_actions);
51}
52
53/*
54 * Called from __free_irq() with desc->lock held after @action has
55 * been removed from the action chain.
56 */
57void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
58{
59	desc->nr_actions--;
60
61	if (action->flags & IRQF_FORCE_RESUME)
62		desc->force_resume_depth--;
63
64	if (action->flags & IRQF_NO_SUSPEND)
65		desc->no_suspend_depth--;
66	else if (action->flags & IRQF_COND_SUSPEND)
67		desc->cond_suspend_depth--;
68}
69
70static bool suspend_device_irq(struct irq_desc *desc)
71{
72	unsigned long chipflags = irq_desc_get_chip(desc)->flags;
73	struct irq_data *irqd = &desc->irq_data;
74
75	if (!desc->action || irq_desc_is_chained(desc) ||
76	    desc->no_suspend_depth)
77		return false;
78
79	if (irqd_is_wakeup_set(irqd)) {
80		irqd_set(irqd, IRQD_WAKEUP_ARMED);
81
82		if ((chipflags & IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND) &&
83		     irqd_irq_disabled(irqd)) {
84			/*
85			 * Interrupt marked for wakeup is in disabled state.
86			 * Enable interrupt here to unmask/enable in irqchip
87			 * to be able to resume with such interrupts.
88			 */
89			__enable_irq(desc);
90			irqd_set(irqd, IRQD_IRQ_ENABLED_ON_SUSPEND);
91		}
92		/*
93		 * We return true here to force the caller to issue
94		 * synchronize_irq(). We need to make sure that the
95		 * IRQD_WAKEUP_ARMED is visible before we return from
96		 * suspend_device_irqs().
97		 */
98		return true;
99	}
100
101	desc->istate |= IRQS_SUSPENDED;
102	__disable_irq(desc);
103
104	/*
105	 * Hardware which has no wakeup source configuration facility
106	 * requires that the non wakeup interrupts are masked at the
107	 * chip level. The chip implementation indicates that with
108	 * IRQCHIP_MASK_ON_SUSPEND.
109	 */
110	if (chipflags & IRQCHIP_MASK_ON_SUSPEND)
111		mask_irq(desc);
112	return true;
113}
114
115/**
116 * suspend_device_irqs - disable all currently enabled interrupt lines
117 *
118 * During system-wide suspend or hibernation device drivers need to be
119 * prevented from receiving interrupts and this function is provided
120 * for this purpose.
121 *
122 * So we disable all interrupts and mark them IRQS_SUSPENDED except
123 * for those which are unused, those which are marked as not
124 * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND
125 * set and those which are marked as active wakeup sources.
126 *
127 * The active wakeup sources are handled by the flow handler entry
128 * code which checks for the IRQD_WAKEUP_ARMED flag, suspends the
129 * interrupt and notifies the pm core about the wakeup.
130 */
131void suspend_device_irqs(void)
132{
133	struct irq_desc *desc;
134	int irq;
135
136	for_each_irq_desc(irq, desc) {
137		unsigned long flags;
138		bool sync;
139
140		if (irq_settings_is_nested_thread(desc))
141			continue;
142		raw_spin_lock_irqsave(&desc->lock, flags);
143		sync = suspend_device_irq(desc);
144		raw_spin_unlock_irqrestore(&desc->lock, flags);
145
146		if (sync)
147			synchronize_irq(irq);
148	}
149}
150
151static void resume_irq(struct irq_desc *desc)
152{
153	struct irq_data *irqd = &desc->irq_data;
154
155	irqd_clear(irqd, IRQD_WAKEUP_ARMED);
156
157	if (irqd_is_enabled_on_suspend(irqd)) {
158		/*
159		 * Interrupt marked for wakeup was enabled during suspend
160		 * entry. Disable such interrupts to restore them back to
161		 * original state.
162		 */
163		__disable_irq(desc);
164		irqd_clear(irqd, IRQD_IRQ_ENABLED_ON_SUSPEND);
165	}
166
167	if (desc->istate & IRQS_SUSPENDED)
168		goto resume;
169
170	/* Force resume the interrupt? */
171	if (!desc->force_resume_depth)
172		return;
173
174	/* Pretend that it got disabled ! */
175	desc->depth++;
176	irq_state_set_disabled(desc);
177	irq_state_set_masked(desc);
178resume:
179	desc->istate &= ~IRQS_SUSPENDED;
180	__enable_irq(desc);
181}
182
183static void resume_irqs(bool want_early)
184{
185	struct irq_desc *desc;
186	int irq;
187
188	for_each_irq_desc(irq, desc) {
189		unsigned long flags;
190		bool is_early = desc->action &&
191			desc->action->flags & IRQF_EARLY_RESUME;
192
193		if (!is_early && want_early)
194			continue;
195		if (irq_settings_is_nested_thread(desc))
196			continue;
197
198		raw_spin_lock_irqsave(&desc->lock, flags);
199		resume_irq(desc);
200		raw_spin_unlock_irqrestore(&desc->lock, flags);
201	}
202}
203
204/**
205 * rearm_wake_irq - rearm a wakeup interrupt line after signaling wakeup
206 * @irq: Interrupt to rearm
207 */
208void rearm_wake_irq(unsigned int irq)
209{
210	unsigned long flags;
211	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
212
213	if (!desc)
214		return;
215
216	if (!(desc->istate & IRQS_SUSPENDED) ||
217	    !irqd_is_wakeup_set(&desc->irq_data))
218		goto unlock;
219
220	desc->istate &= ~IRQS_SUSPENDED;
221	irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
222	__enable_irq(desc);
223
224unlock:
225	irq_put_desc_busunlock(desc, flags);
226}
227
228/**
229 * irq_pm_syscore_resume - enable interrupt lines early
230 *
231 * Enable all interrupt lines with %IRQF_EARLY_RESUME set.
232 */
233static void irq_pm_syscore_resume(void)
234{
235	resume_irqs(true);
236}
237
238static struct syscore_ops irq_pm_syscore_ops = {
239	.resume		= irq_pm_syscore_resume,
240};
241
242static int __init irq_pm_init_ops(void)
243{
244	register_syscore_ops(&irq_pm_syscore_ops);
245	return 0;
246}
247
248device_initcall(irq_pm_init_ops);
249
250/**
251 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()
252 *
253 * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously
254 * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag
255 * set as well as those with %IRQF_FORCE_RESUME.
256 */
257void resume_device_irqs(void)
258{
259	resume_irqs(false);
260}
261