1 files changed, 262 insertions, 0 deletions
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
new file mode 100644
index 000000000..ce0adb22e
--- /dev/null
+++ b/kernel/irq/pm.c
@@ -0,0 +1,262 @@
+// 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)
+{
+	unsigned long chipflags = irq_desc_get_chip(desc)->flags;
+	struct irq_data *irqd = &desc->irq_data;
+
+	if (!desc->action || irq_desc_is_chained(desc) ||
+	    desc->no_suspend_depth)
+		return false;
+
+	if (irqd_is_wakeup_set(irqd)) {
+		irqd_set(irqd, IRQD_WAKEUP_ARMED);
+
+		if ((chipflags & IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND) &&
+		     irqd_irq_disabled(irqd)) {
+			/*
+			 * Interrupt marked for wakeup is in disabled state.
+			 * Enable interrupt here to unmask/enable in irqchip
+			 * to be able to resume with such interrupts.
+			 */
+			__enable_irq(desc);
+			irqd_set(irqd, IRQD_IRQ_ENABLED_ON_SUSPEND);
+		}
+		/*
+		 * 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 (chipflags & 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)
+{
+	struct irq_data *irqd = &desc->irq_data;
+
+	irqd_clear(irqd, IRQD_WAKEUP_ARMED);
+
+	if (irqd_is_enabled_on_suspend(irqd)) {
+		/*
+		 * Interrupt marked for wakeup was enabled during suspend
+		 * entry. Disable such interrupts to restore them back to
+		 * original state.
+		 */
+		__disable_irq(desc);
+		irqd_clear(irqd, IRQD_IRQ_ENABLED_ON_SUSPEND);
+	}
+
+	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)
+		return;
+
+	if (!(desc->istate & IRQS_SUSPENDED) ||
+	    !irqd_is_wakeup_set(&desc->irq_data))
+		goto unlock;
+
+	desc->istate &= ~IRQS_SUSPENDED;
+	irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
+	__enable_irq(desc);
+
+unlock:
+	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);