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         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 }