kernel/irq/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
  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         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  */
 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
 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
 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  */
 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
 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  */
 208 void resume_device_irqs(void)
 209 {
 210         resume_irqs(false);
 211 }
 212 EXPORT_SYMBOL_GPL(resume_device_irqs);