linux-stable/kernel/irq/pm.c
Rafael J. Wysocki 3a79bc63d9 PCI: irq: Introduce rearm_wake_irq()
Introduce a new function, rearm_wake_irq(), allowing a wakeup IRQ
to be armed for systen wakeup detection again without running any
action handlers associated with it after it has been armed for
wakeup detection and triggered.

That is useful for IRQs, like ACPI SCI, that may deliver wakeup
as well as non-wakeup interrupts when armed for systen wakeup
detection.  In those cases, it may be possible to determine whether
or not the delivered interrupt is a systen wakeup one without
running the entire action handler (or handlers, if the IRQ is
shared) for the IRQ, and if the interrupt turns out to be a
non-wakeup one, the IRQ can be rearmed with the help of the
new function.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2019-07-23 09:37:51 +02:00

232 lines
5.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
* This file contains power management functions related to interrupts.
*/
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include "internals.h"
bool irq_pm_check_wakeup(struct irq_desc *desc)
{
if (irqd_is_wakeup_armed(&desc->irq_data)) {
irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
desc->istate |= IRQS_SUSPENDED | IRQS_PENDING;
desc->depth++;
irq_disable(desc);
pm_system_irq_wakeup(irq_desc_get_irq(desc));
return true;
}
return false;
}
/*
* Called from __setup_irq() with desc->lock held after @action has
* been installed in the action chain.
*/
void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action)
{
desc->nr_actions++;
if (action->flags & IRQF_FORCE_RESUME)
desc->force_resume_depth++;
WARN_ON_ONCE(desc->force_resume_depth &&
desc->force_resume_depth != desc->nr_actions);
if (action->flags & IRQF_NO_SUSPEND)
desc->no_suspend_depth++;
else if (action->flags & IRQF_COND_SUSPEND)
desc->cond_suspend_depth++;
WARN_ON_ONCE(desc->no_suspend_depth &&
(desc->no_suspend_depth +
desc->cond_suspend_depth) != desc->nr_actions);
}
/*
* Called from __free_irq() with desc->lock held after @action has
* been removed from the action chain.
*/
void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
{
desc->nr_actions--;
if (action->flags & IRQF_FORCE_RESUME)
desc->force_resume_depth--;
if (action->flags & IRQF_NO_SUSPEND)
desc->no_suspend_depth--;
else if (action->flags & IRQF_COND_SUSPEND)
desc->cond_suspend_depth--;
}
static bool suspend_device_irq(struct irq_desc *desc)
{
if (!desc->action || irq_desc_is_chained(desc) ||
desc->no_suspend_depth)
return false;
if (irqd_is_wakeup_set(&desc->irq_data)) {
irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
/*
* We return true here to force the caller to issue
* synchronize_irq(). We need to make sure that the
* IRQD_WAKEUP_ARMED is visible before we return from
* suspend_device_irqs().
*/
return true;
}
desc->istate |= IRQS_SUSPENDED;
__disable_irq(desc);
/*
* Hardware which has no wakeup source configuration facility
* requires that the non wakeup interrupts are masked at the
* chip level. The chip implementation indicates that with
* IRQCHIP_MASK_ON_SUSPEND.
*/
if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND)
mask_irq(desc);
return true;
}
/**
* suspend_device_irqs - disable all currently enabled interrupt lines
*
* During system-wide suspend or hibernation device drivers need to be
* prevented from receiving interrupts and this function is provided
* for this purpose.
*
* So we disable all interrupts and mark them IRQS_SUSPENDED except
* for those which are unused, those which are marked as not
* suspendable via an interrupt request with the flag IRQF_NO_SUSPEND
* set and those which are marked as active wakeup sources.
*
* The active wakeup sources are handled by the flow handler entry
* code which checks for the IRQD_WAKEUP_ARMED flag, suspends the
* interrupt and notifies the pm core about the wakeup.
*/
void suspend_device_irqs(void)
{
struct irq_desc *desc;
int irq;
for_each_irq_desc(irq, desc) {
unsigned long flags;
bool sync;
if (irq_settings_is_nested_thread(desc))
continue;
raw_spin_lock_irqsave(&desc->lock, flags);
sync = suspend_device_irq(desc);
raw_spin_unlock_irqrestore(&desc->lock, flags);
if (sync)
synchronize_irq(irq);
}
}
EXPORT_SYMBOL_GPL(suspend_device_irqs);
static void resume_irq(struct irq_desc *desc)
{
irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
if (desc->istate & IRQS_SUSPENDED)
goto resume;
/* Force resume the interrupt? */
if (!desc->force_resume_depth)
return;
/* Pretend that it got disabled ! */
desc->depth++;
irq_state_set_disabled(desc);
irq_state_set_masked(desc);
resume:
desc->istate &= ~IRQS_SUSPENDED;
__enable_irq(desc);
}
static void resume_irqs(bool want_early)
{
struct irq_desc *desc;
int irq;
for_each_irq_desc(irq, desc) {
unsigned long flags;
bool is_early = desc->action &&
desc->action->flags & IRQF_EARLY_RESUME;
if (!is_early && want_early)
continue;
if (irq_settings_is_nested_thread(desc))
continue;
raw_spin_lock_irqsave(&desc->lock, flags);
resume_irq(desc);
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
}
/**
* rearm_wake_irq - rearm a wakeup interrupt line after signaling wakeup
* @irq: Interrupt to rearm
*/
void rearm_wake_irq(unsigned int irq)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
if (!desc || !(desc->istate & IRQS_SUSPENDED) ||
!irqd_is_wakeup_set(&desc->irq_data))
return;
desc->istate &= ~IRQS_SUSPENDED;
irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
__enable_irq(desc);
irq_put_desc_busunlock(desc, flags);
}
/**
* irq_pm_syscore_ops - enable interrupt lines early
*
* Enable all interrupt lines with %IRQF_EARLY_RESUME set.
*/
static void irq_pm_syscore_resume(void)
{
resume_irqs(true);
}
static struct syscore_ops irq_pm_syscore_ops = {
.resume = irq_pm_syscore_resume,
};
static int __init irq_pm_init_ops(void)
{
register_syscore_ops(&irq_pm_syscore_ops);
return 0;
}
device_initcall(irq_pm_init_ops);
/**
* resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()
*
* Enable all non-%IRQF_EARLY_RESUME interrupt lines previously
* disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag
* set as well as those with %IRQF_FORCE_RESUME.
*/
void resume_device_irqs(void)
{
resume_irqs(false);
}
EXPORT_SYMBOL_GPL(resume_device_irqs);