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       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                 :        210 : void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action)
      34                 :            : {
      35                 :        210 :         desc->nr_actions++;
      36                 :            : 
      37         [ -  + ]:        210 :         if (action->flags & IRQF_FORCE_RESUME)
      38                 :          0 :                 desc->force_resume_depth++;
      39                 :            : 
      40   [ -  +  -  -  :        420 :         WARN_ON_ONCE(desc->force_resume_depth &&
                   -  + ]
      41                 :            :                      desc->force_resume_depth != desc->nr_actions);
      42                 :            : 
      43         [ +  + ]:        210 :         if (action->flags & IRQF_NO_SUSPEND)
      44                 :         21 :                 desc->no_suspend_depth++;
      45         [ -  + ]:        189 :         else if (action->flags & IRQF_COND_SUSPEND)
      46                 :          0 :                 desc->cond_suspend_depth++;
      47                 :            : 
      48   [ +  +  +  -  :        420 :         WARN_ON_ONCE(desc->no_suspend_depth &&
                   -  + ]
      49                 :            :                      (desc->no_suspend_depth +
      50                 :            :                         desc->cond_suspend_depth) != desc->nr_actions);
      51                 :        210 : }
      52                 :            : 
      53                 :            : /*
      54                 :            :  * Called from __free_irq() with desc->lock held after @action has
      55                 :            :  * been removed from the action chain.
      56                 :            :  */
      57                 :         21 : void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
      58                 :            : {
      59                 :         21 :         desc->nr_actions--;
      60                 :            : 
      61         [ -  + ]:         21 :         if (action->flags & IRQF_FORCE_RESUME)
      62                 :          0 :                 desc->force_resume_depth--;
      63                 :            : 
      64         [ -  + ]:         21 :         if (action->flags & IRQF_NO_SUSPEND)
      65                 :          0 :                 desc->no_suspend_depth--;
      66         [ -  + ]:         21 :         else if (action->flags & IRQF_COND_SUSPEND)
      67                 :          0 :                 desc->cond_suspend_depth--;
      68                 :         21 : }
      69                 :            : 
      70                 :          0 : static bool suspend_device_irq(struct irq_desc *desc)
      71                 :            : {
      72         [ #  # ]:          0 :         if (!desc->action || irq_desc_is_chained(desc) ||
      73         [ #  # ]:          0 :             desc->no_suspend_depth)
      74                 :            :                 return false;
      75                 :            : 
      76         [ #  # ]:          0 :         if (irqd_is_wakeup_set(&desc->irq_data)) {
      77                 :          0 :                 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                 :          0 :                 return true;
      85                 :            :         }
      86                 :            : 
      87                 :          0 :         desc->istate |= IRQS_SUSPENDED;
      88                 :          0 :         __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         [ #  # ]:          0 :         if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND)
      97                 :          0 :                 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                 :          0 : void suspend_device_irqs(void)
     118                 :            : {
     119                 :          0 :         struct irq_desc *desc;
     120                 :          0 :         int irq;
     121                 :            : 
     122   [ #  #  #  # ]:          0 :         for_each_irq_desc(irq, desc) {
     123                 :          0 :                 unsigned long flags;
     124                 :          0 :                 bool sync;
     125                 :            : 
     126         [ #  # ]:          0 :                 if (irq_settings_is_nested_thread(desc))
     127                 :          0 :                         continue;
     128                 :          0 :                 raw_spin_lock_irqsave(&desc->lock, flags);
     129                 :          0 :                 sync = suspend_device_irq(desc);
     130                 :          0 :                 raw_spin_unlock_irqrestore(&desc->lock, flags);
     131                 :            : 
     132         [ #  # ]:          0 :                 if (sync)
     133                 :          0 :                         synchronize_irq(irq);
     134                 :            :         }
     135                 :          0 : }
     136                 :            : EXPORT_SYMBOL_GPL(suspend_device_irqs);
     137                 :            : 
     138                 :          0 : static void resume_irq(struct irq_desc *desc)
     139                 :            : {
     140         [ #  # ]:          0 :         irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
     141                 :            : 
     142         [ #  # ]:          0 :         if (desc->istate & IRQS_SUSPENDED)
     143                 :          0 :                 goto resume;
     144                 :            : 
     145                 :            :         /* Force resume the interrupt? */
     146         [ #  # ]:          0 :         if (!desc->force_resume_depth)
     147                 :            :                 return;
     148                 :            : 
     149                 :            :         /* Pretend that it got disabled ! */
     150                 :          0 :         desc->depth++;
     151                 :          0 :         irq_state_set_disabled(desc);
     152                 :          0 :         irq_state_set_masked(desc);
     153                 :          0 : resume:
     154                 :          0 :         desc->istate &= ~IRQS_SUSPENDED;
     155                 :          0 :         __enable_irq(desc);
     156                 :            : }
     157                 :            : 
     158                 :          0 : static void resume_irqs(bool want_early)
     159                 :            : {
     160                 :          0 :         struct irq_desc *desc;
     161                 :          0 :         int irq;
     162                 :            : 
     163   [ #  #  #  # ]:          0 :         for_each_irq_desc(irq, desc) {
     164                 :          0 :                 unsigned long flags;
     165         [ #  # ]:          0 :                 bool is_early = desc->action &&
     166         [ #  # ]:          0 :                         desc->action->flags & IRQF_EARLY_RESUME;
     167                 :            : 
     168         [ #  # ]:          0 :                 if (!is_early && want_early)
     169                 :          0 :                         continue;
     170         [ #  # ]:          0 :                 if (irq_settings_is_nested_thread(desc))
     171                 :          0 :                         continue;
     172                 :            : 
     173                 :          0 :                 raw_spin_lock_irqsave(&desc->lock, flags);
     174                 :          0 :                 resume_irq(desc);
     175                 :          0 :                 raw_spin_unlock_irqrestore(&desc->lock, flags);
     176                 :            :         }
     177                 :          0 : }
     178                 :            : 
     179                 :            : /**
     180                 :            :  * rearm_wake_irq - rearm a wakeup interrupt line after signaling wakeup
     181                 :            :  * @irq: Interrupt to rearm
     182                 :            :  */
     183                 :          0 : void rearm_wake_irq(unsigned int irq)
     184                 :            : {
     185                 :          0 :         unsigned long flags;
     186                 :          0 :         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
     187                 :            : 
     188   [ #  #  #  #  :          0 :         if (!desc || !(desc->istate & IRQS_SUSPENDED) ||
                   #  # ]
     189         [ #  # ]:          0 :             !irqd_is_wakeup_set(&desc->irq_data))
     190                 :          0 :                 return;
     191                 :            : 
     192                 :          0 :         desc->istate &= ~IRQS_SUSPENDED;
     193                 :          0 :         irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
     194                 :          0 :         __enable_irq(desc);
     195                 :            : 
     196                 :          0 :         irq_put_desc_busunlock(desc, flags);
     197                 :            : }
     198                 :            : 
     199                 :            : /**
     200                 :            :  * irq_pm_syscore_ops - enable interrupt lines early
     201                 :            :  *
     202                 :            :  * Enable all interrupt lines with %IRQF_EARLY_RESUME set.
     203                 :            :  */
     204                 :          0 : static void irq_pm_syscore_resume(void)
     205                 :            : {
     206                 :          0 :         resume_irqs(true);
     207                 :          0 : }
     208                 :            : 
     209                 :            : static struct syscore_ops irq_pm_syscore_ops = {
     210                 :            :         .resume         = irq_pm_syscore_resume,
     211                 :            : };
     212                 :            : 
     213                 :         21 : static int __init irq_pm_init_ops(void)
     214                 :            : {
     215                 :         21 :         register_syscore_ops(&irq_pm_syscore_ops);
     216                 :         21 :         return 0;
     217                 :            : }
     218                 :            : 
     219                 :            : device_initcall(irq_pm_init_ops);
     220                 :            : 
     221                 :            : /**
     222                 :            :  * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()
     223                 :            :  *
     224                 :            :  * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously
     225                 :            :  * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag
     226                 :            :  * set as well as those with %IRQF_FORCE_RESUME.
     227                 :            :  */
     228                 :          0 : void resume_device_irqs(void)
     229                 :            : {
     230                 :          0 :         resume_irqs(false);
     231                 :          0 : }
     232                 :            : EXPORT_SYMBOL_GPL(resume_device_irqs);