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
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 */
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 */
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
70 static 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 */
131 void 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
151 static 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);
178 resume:
179 desc->istate &= ~IRQS_SUSPENDED;
180 __enable_irq(desc);
181 }
182
183 static 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 */
208 void 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
224 unlock:
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 */
233 static void irq_pm_syscore_resume(void)
234 {
235 resume_irqs(true);
236 }
237
238 static struct syscore_ops irq_pm_syscore_ops = {
239 .resume = irq_pm_syscore_resume,
240 };
241
242 static int __init irq_pm_init_ops(void)
243 {
244 register_syscore_ops(&irq_pm_syscore_ops);
245 return 0;
246 }
247
248 device_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 */
257 void resume_device_irqs(void)
258 {
259 resume_irqs(false);
260 }
261
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.