pm.c

  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(&desc->irq_data, IRQD_WAKEUP_ARMED);
 19	desc->istate |= IRQS_SUSPENDED | IRQS_PENDING;
 20	desc->depth++;
 21	irq_disable(desc);
 22	pm_system_irq_wakeup(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(irqd)) {
 75		irqd_set(irqd, IRQD_WAKEUP_ARMED);
 76
 77		if ((chipflags & IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND) &&
 78		     irqd_irq_disabled(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(irqd, 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(irqd, IRQD_WAKEUP_ARMED);
149
150	if (irqd_is_enabled_on_suspend(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(irqd, 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)(&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(&desc->irq_data))
204			return;
205
206		desc->istate &= ~IRQS_SUSPENDED;
207		irqd_set(&desc->irq_data, 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(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(&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(false);
249}