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