3 files changed, 150 insertions, 4 deletions

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 6f1c7a566b95..eb9a4ea394ab 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -948,6 +948,22 @@ int irq_chip_retrigger_hierarchy(struct irq_data *data)
 
 	return -ENOSYS;
 }
+
+/**
+ * irq_chip_set_wake_parent - Set/reset wake-up on the parent interrupt
+ * @data:	Pointer to interrupt specific data
+ * @on:		Whether to set or reset the wake-up capability of this irq
+ *
+ * Conditional, as the underlying parent chip might not implement it.
+ */
+int irq_chip_set_wake_parent(struct irq_data *data, unsigned int on)
+{
+	data = data->parent_data;
+	if (data->chip->irq_set_wake)
+		return data->chip->irq_set_wake(data, on);
+
+	return -ENOSYS;
+}
 #endif
 
 /**
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 886d09e691d5..e68932bb308e 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -68,14 +68,20 @@ static void __synchronize_hardirq(struct irq_desc *desc)
  *	Do not use this for shutdown scenarios where you must be sure
  *	that all parts (hardirq and threaded handler) have completed.
  *
+ *	Returns: false if a threaded handler is active.
+ *
  *	This function may be called - with care - from IRQ context.
  */
-void synchronize_hardirq(unsigned int irq)
+bool synchronize_hardirq(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
-	if (desc)
+	if (desc) {
 		__synchronize_hardirq(desc);
+		return !atomic_read(&desc->threads_active);
+	}
+
+	return true;
 }
 EXPORT_SYMBOL(synchronize_hardirq);
 
@@ -440,6 +446,32 @@ void disable_irq(unsigned int irq)
 }
 EXPORT_SYMBOL(disable_irq);
 
+/**
+ *	disable_hardirq - disables an irq and waits for hardirq completion
+ *	@irq: Interrupt to disable
+ *
+ *	Disable the selected interrupt line.  Enables and Disables are
+ *	nested.
+ *	This function waits for any pending hard IRQ handlers for this
+ *	interrupt to complete before returning. If you use this function while
+ *	holding a resource the hard IRQ handler may need you will deadlock.
+ *
+ *	When used to optimistically disable an interrupt from atomic context
+ *	the return value must be checked.
+ *
+ *	Returns: false if a threaded handler is active.
+ *
+ *	This function may be called - with care - from IRQ context.
+ */
+bool disable_hardirq(unsigned int irq)
+{
+	if (!__disable_irq_nosync(irq))
+		return synchronize_hardirq(irq);
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(disable_hardirq);
+
 void __enable_irq(struct irq_desc *desc, unsigned int irq)
 {
 	switch (desc->depth) {
@@ -1766,3 +1798,94 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler,
 
 	return retval;
 }
+
+/**
+ *	irq_get_irqchip_state - returns the irqchip state of a interrupt.
+ *	@irq: Interrupt line that is forwarded to a VM
+ *	@which: One of IRQCHIP_STATE_* the caller wants to know about
+ *	@state: a pointer to a boolean where the state is to be storeed
+ *
+ *	This call snapshots the internal irqchip state of an
+ *	interrupt, returning into @state the bit corresponding to
+ *	stage @which
+ *
+ *	This function should be called with preemption disabled if the
+ *	interrupt controller has per-cpu registers.
+ */
+int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
+			  bool *state)
+{
+	struct irq_desc *desc;
+	struct irq_data *data;
+	struct irq_chip *chip;
+	unsigned long flags;
+	int err = -EINVAL;
+
+	desc = irq_get_desc_buslock(irq, &flags, 0);
+	if (!desc)
+		return err;
+
+	data = irq_desc_get_irq_data(desc);
+
+	do {
+		chip = irq_data_get_irq_chip(data);
+		if (chip->irq_get_irqchip_state)
+			break;
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+		data = data->parent_data;
+#else
+		data = NULL;
+#endif
+	} while (data);
+
+	if (data)
+		err = chip->irq_get_irqchip_state(data, which, state);
+
+	irq_put_desc_busunlock(desc, flags);
+	return err;
+}
+
+/**
+ *	irq_set_irqchip_state - set the state of a forwarded interrupt.
+ *	@irq: Interrupt line that is forwarded to a VM
+ *	@which: State to be restored (one of IRQCHIP_STATE_*)
+ *	@val: Value corresponding to @which
+ *
+ *	This call sets the internal irqchip state of an interrupt,
+ *	depending on the value of @which.
+ *
+ *	This function should be called with preemption disabled if the
+ *	interrupt controller has per-cpu registers.
+ */
+int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
+			  bool val)
+{
+	struct irq_desc *desc;
+	struct irq_data *data;
+	struct irq_chip *chip;
+	unsigned long flags;
+	int err = -EINVAL;
+
+	desc = irq_get_desc_buslock(irq, &flags, 0);
+	if (!desc)
+		return err;
+
+	data = irq_desc_get_irq_data(desc);
+
+	do {
+		chip = irq_data_get_irq_chip(data);
+		if (chip->irq_set_irqchip_state)
+			break;
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+		data = data->parent_data;
+#else
+		data = NULL;
+#endif
+	} while (data);
+
+	if (data)
+		err = chip->irq_set_irqchip_state(data, which, val);
+
+	irq_put_desc_busunlock(desc, flags);
+	return err;
+}
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 3e18163f336f..474de5cb394d 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -310,8 +310,15 @@ void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
 	struct msi_desc *desc;
 
 	for_each_msi_entry(desc, dev) {
-		irq_domain_free_irqs(desc->irq, desc->nvec_used);
-		desc->irq = 0;
+		/*
+		 * We might have failed to allocate an MSI early
+		 * enough that there is no IRQ associated to this
+		 * entry. If that's the case, don't do anything.
+		 */
+		if (desc->irq) {
+			irq_domain_free_irqs(desc->irq, desc->nvec_used);
+			desc->irq = 0;
+		}
 	}
 }