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
irq_pm_check_wakeup(struct irq_desc * desc)16 bool 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 */
irq_pm_install_action(struct irq_desc * desc,struct irqaction * action)33 void 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 */
irq_pm_remove_action(struct irq_desc * desc,struct irqaction * action)57 void 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
suspend_device_irq(struct irq_desc * desc)70 static bool suspend_device_irq(struct irq_desc *desc)
71 {
72 if (!desc->action || irq_desc_is_chained(desc) ||
73 desc->no_suspend_depth)
74 return false;
75
76 if (irqd_is_wakeup_set(&desc->irq_data)) {
77 irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
78 /*
79 * We return true here to force the caller to issue
80 * synchronize_irq(). We need to make sure that the
81 * IRQD_WAKEUP_ARMED is visible before we return from
82 * suspend_device_irqs().
83 */
84 return true;
85 }
86
87 desc->istate |= IRQS_SUSPENDED;
88 __disable_irq(desc);
89
90 /*
91 * Hardware which has no wakeup source configuration facility
92 * requires that the non wakeup interrupts are masked at the
93 * chip level. The chip implementation indicates that with
94 * IRQCHIP_MASK_ON_SUSPEND.
95 */
96 if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND)
97 mask_irq(desc);
98 return true;
99 }
100
101 /**
102 * suspend_device_irqs - disable all currently enabled interrupt lines
103 *
104 * During system-wide suspend or hibernation device drivers need to be
105 * prevented from receiving interrupts and this function is provided
106 * for this purpose.
107 *
108 * So we disable all interrupts and mark them IRQS_SUSPENDED except
109 * for those which are unused, those which are marked as not
110 * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND
111 * set and those which are marked as active wakeup sources.
112 *
113 * The active wakeup sources are handled by the flow handler entry
114 * code which checks for the IRQD_WAKEUP_ARMED flag, suspends the
115 * interrupt and notifies the pm core about the wakeup.
116 */
suspend_device_irqs(void)117 void suspend_device_irqs(void)
118 {
119 struct irq_desc *desc;
120 int irq;
121
122 for_each_irq_desc(irq, desc) {
123 unsigned long flags;
124 bool sync;
125
126 if (irq_settings_is_nested_thread(desc))
127 continue;
128 raw_spin_lock_irqsave(&desc->lock, flags);
129 sync = suspend_device_irq(desc);
130 raw_spin_unlock_irqrestore(&desc->lock, flags);
131
132 if (sync)
133 synchronize_irq(irq);
134 }
135 }
136 EXPORT_SYMBOL_GPL(suspend_device_irqs);
137
resume_irq(struct irq_desc * desc)138 static void resume_irq(struct irq_desc *desc)
139 {
140 irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
141
142 if (desc->istate & IRQS_SUSPENDED)
143 goto resume;
144
145 /* Force resume the interrupt? */
146 if (!desc->force_resume_depth)
147 return;
148
149 /* Pretend that it got disabled ! */
150 desc->depth++;
151 irq_state_set_disabled(desc);
152 irq_state_set_masked(desc);
153 resume:
154 desc->istate &= ~IRQS_SUSPENDED;
155 __enable_irq(desc);
156 }
157
resume_irqs(bool want_early)158 static void resume_irqs(bool want_early)
159 {
160 struct irq_desc *desc;
161 int irq;
162
163 for_each_irq_desc(irq, desc) {
164 unsigned long flags;
165 bool is_early = desc->action &&
166 desc->action->flags & IRQF_EARLY_RESUME;
167
168 if (!is_early && want_early)
169 continue;
170 if (irq_settings_is_nested_thread(desc))
171 continue;
172
173 raw_spin_lock_irqsave(&desc->lock, flags);
174 resume_irq(desc);
175 raw_spin_unlock_irqrestore(&desc->lock, flags);
176 }
177 }
178
179 /**
180 * irq_pm_syscore_ops - enable interrupt lines early
181 *
182 * Enable all interrupt lines with %IRQF_EARLY_RESUME set.
183 */
irq_pm_syscore_resume(void)184 static void irq_pm_syscore_resume(void)
185 {
186 resume_irqs(true);
187 }
188
189 static struct syscore_ops irq_pm_syscore_ops = {
190 .resume = irq_pm_syscore_resume,
191 };
192
irq_pm_init_ops(void)193 static int __init irq_pm_init_ops(void)
194 {
195 register_syscore_ops(&irq_pm_syscore_ops);
196 return 0;
197 }
198
199 device_initcall(irq_pm_init_ops);
200
201 /**
202 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()
203 *
204 * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously
205 * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag
206 * set as well as those with %IRQF_FORCE_RESUME.
207 */
resume_device_irqs(void)208 void resume_device_irqs(void)
209 {
210 resume_irqs(false);
211 }
212 EXPORT_SYMBOL_GPL(resume_device_irqs);
213
