Line data    Source code

       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           0 : bool irq_pm_check_wakeup(struct irq_desc *desc)
      17             : {
      18           0 :         if (irqd_is_wakeup_armed(&desc->irq_data)) {
      19           0 :                 irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
      20           0 :                 desc->istate |= IRQS_SUSPENDED | IRQS_PENDING;
      21           0 :                 desc->depth++;
      22           0 :                 irq_disable(desc);
      23           0 :                 pm_system_irq_wakeup(irq_desc_get_irq(desc));
      24           0 :                 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           2 : void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action)
      34             : {
      35           2 :         desc->nr_actions++;
      36             : 
      37           2 :         if (action->flags & IRQF_FORCE_RESUME)
      38           0 :                 desc->force_resume_depth++;
      39             : 
      40           2 :         WARN_ON_ONCE(desc->force_resume_depth &&
      41             :                      desc->force_resume_depth != desc->nr_actions);
      42             : 
      43           2 :         if (action->flags & IRQF_NO_SUSPEND)
      44           1 :                 desc->no_suspend_depth++;
      45           1 :         else if (action->flags & IRQF_COND_SUSPEND)
      46           0 :                 desc->cond_suspend_depth++;
      47             : 
      48           2 :         WARN_ON_ONCE(desc->no_suspend_depth &&
      49             :                      (desc->no_suspend_depth +
      50             :                         desc->cond_suspend_depth) != desc->nr_actions);
      51           2 : }
      52             : 
      53             : /*
      54             :  * Called from __free_irq() with desc->lock held after @action has
      55             :  * been removed from the action chain.
      56             :  */
      57           0 : void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
      58             : {
      59           0 :         desc->nr_actions--;
      60             : 
      61           0 :         if (action->flags & IRQF_FORCE_RESUME)
      62           0 :                 desc->force_resume_depth--;
      63             : 
      64           0 :         if (action->flags & IRQF_NO_SUSPEND)
      65           0 :                 desc->no_suspend_depth--;
      66           0 :         else if (action->flags & IRQF_COND_SUSPEND)
      67           0 :                 desc->cond_suspend_depth--;
      68           0 : }
      69             : 
      70           0 : static bool suspend_device_irq(struct irq_desc *desc)
      71             : {
      72           0 :         unsigned long chipflags = irq_desc_get_chip(desc)->flags;
      73           0 :         struct irq_data *irqd = &desc->irq_data;
      74             : 
      75           0 :         if (!desc->action || irq_desc_is_chained(desc) ||
      76           0 :             desc->no_suspend_depth)
      77             :                 return false;
      78             : 
      79           0 :         if (irqd_is_wakeup_set(irqd)) {
      80           0 :                 irqd_set(irqd, IRQD_WAKEUP_ARMED);
      81             : 
      82           0 :                 if ((chipflags & IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND) &&
      83           0 :                      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           0 :                         __enable_irq(desc);
      90           0 :                         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           0 :         desc->istate |= IRQS_SUSPENDED;
     102           0 :         __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           0 :         if (chipflags & IRQCHIP_MASK_ON_SUSPEND)
     111           0 :                 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           0 : void suspend_device_irqs(void)
     132             : {
     133             :         struct irq_desc *desc;
     134             :         int irq;
     135             : 
     136           0 :         for_each_irq_desc(irq, desc) {
     137             :                 unsigned long flags;
     138             :                 bool sync;
     139             : 
     140           0 :                 if (irq_settings_is_nested_thread(desc))
     141           0 :                         continue;
     142           0 :                 raw_spin_lock_irqsave(&desc->lock, flags);
     143           0 :                 sync = suspend_device_irq(desc);
     144           0 :                 raw_spin_unlock_irqrestore(&desc->lock, flags);
     145             : 
     146           0 :                 if (sync)
     147           0 :                         synchronize_irq(irq);
     148             :         }
     149           0 : }
     150             : 
     151           0 : static void resume_irq(struct irq_desc *desc)
     152             : {
     153           0 :         struct irq_data *irqd = &desc->irq_data;
     154             : 
     155           0 :         irqd_clear(irqd, IRQD_WAKEUP_ARMED);
     156             : 
     157           0 :         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           0 :                 __disable_irq(desc);
     164           0 :                 irqd_clear(irqd, IRQD_IRQ_ENABLED_ON_SUSPEND);
     165             :         }
     166             : 
     167           0 :         if (desc->istate & IRQS_SUSPENDED)
     168             :                 goto resume;
     169             : 
     170             :         /* Force resume the interrupt? */
     171           0 :         if (!desc->force_resume_depth)
     172             :                 return;
     173             : 
     174             :         /* Pretend that it got disabled ! */
     175           0 :         desc->depth++;
     176           0 :         irq_state_set_disabled(desc);
     177             :         irq_state_set_masked(desc);
     178             : resume:
     179           0 :         desc->istate &= ~IRQS_SUSPENDED;
     180           0 :         __enable_irq(desc);
     181             : }
     182             : 
     183           0 : static void resume_irqs(bool want_early)
     184             : {
     185             :         struct irq_desc *desc;
     186             :         int irq;
     187             : 
     188           0 :         for_each_irq_desc(irq, desc) {
     189             :                 unsigned long flags;
     190           0 :                 bool is_early = desc->action &&
     191           0 :                         desc->action->flags & IRQF_EARLY_RESUME;
     192             : 
     193           0 :                 if (!is_early && want_early)
     194           0 :                         continue;
     195           0 :                 if (irq_settings_is_nested_thread(desc))
     196           0 :                         continue;
     197             : 
     198           0 :                 raw_spin_lock_irqsave(&desc->lock, flags);
     199           0 :                 resume_irq(desc);
     200           0 :                 raw_spin_unlock_irqrestore(&desc->lock, flags);
     201             :         }
     202           0 : }
     203             : 
     204             : /**
     205             :  * rearm_wake_irq - rearm a wakeup interrupt line after signaling wakeup
     206             :  * @irq: Interrupt to rearm
     207             :  */
     208           0 : void rearm_wake_irq(unsigned int irq)
     209             : {
     210             :         unsigned long flags;
     211           0 :         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
     212             : 
     213           0 :         if (!desc)
     214           0 :                 return;
     215             : 
     216           0 :         if (!(desc->istate & IRQS_SUSPENDED) ||
     217           0 :             !irqd_is_wakeup_set(&desc->irq_data))
     218             :                 goto unlock;
     219             : 
     220           0 :         desc->istate &= ~IRQS_SUSPENDED;
     221           0 :         irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
     222           0 :         __enable_irq(desc);
     223             : 
     224             : unlock:
     225           0 :         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           0 : static void irq_pm_syscore_resume(void)
     234             : {
     235           0 :         resume_irqs(true);
     236           0 : }
     237             : 
     238             : static struct syscore_ops irq_pm_syscore_ops = {
     239             :         .resume         = irq_pm_syscore_resume,
     240             : };
     241             : 
     242           1 : static int __init irq_pm_init_ops(void)
     243             : {
     244           1 :         register_syscore_ops(&irq_pm_syscore_ops);
     245           1 :         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           0 : void resume_device_irqs(void)
     258             : {
     259           0 :         resume_irqs(false);
     260           0 : }