xref: /linux/kernel/irq/pm.c (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
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 	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  */
suspend_device_irqs(void)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 
resume_irq(struct irq_desc * desc)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 
resume_irqs(bool want_early)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  */
rearm_wake_irq(unsigned int irq)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  */
irq_pm_syscore_resume(void)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 
irq_pm_init_ops(void)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  */
resume_device_irqs(void)257 void resume_device_irqs(void)
258 {
259 	resume_irqs(false);
260 }
261