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

source code of linux/kernel/irq/pm.c