1 files changed, 69 insertions, 21 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 78f3ddeb7fe4..e8f7f179bf77 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/random.h>
 #include <linux/interrupt.h>
+#include <linux/irqdomain.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/sched/rt.h>
@@ -34,8 +35,9 @@ static int __init setup_forced_irqthreads(char *arg)
 early_param("threadirqs", setup_forced_irqthreads);
 #endif
 
-static void __synchronize_hardirq(struct irq_desc *desc)
+static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
 {
+	struct irq_data *irqd = irq_desc_get_irq_data(desc);
 	bool inprogress;
 
 	do {
@@ -51,6 +53,20 @@ static void __synchronize_hardirq(struct irq_desc *desc)
 		/* Ok, that indicated we're done: double-check carefully. */
 		raw_spin_lock_irqsave(&desc->lock, flags);
 		inprogress = irqd_irq_inprogress(&desc->irq_data);
+
+		/*
+		 * If requested and supported, check at the chip whether it
+		 * is in flight at the hardware level, i.e. already pending
+		 * in a CPU and waiting for service and acknowledge.
+		 */
+		if (!inprogress && sync_chip) {
+			/*
+			 * Ignore the return code. inprogress is only updated
+			 * when the chip supports it.
+			 */
+			__irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
+						&inprogress);
+		}
 		raw_spin_unlock_irqrestore(&desc->lock, flags);
 
 		/* Oops, that failed? */
@@ -73,13 +89,18 @@ static void __synchronize_hardirq(struct irq_desc *desc)
  *	Returns: false if a threaded handler is active.
  *
  *	This function may be called - with care - from IRQ context.
+ *
+ *	It does not check whether there is an interrupt in flight at the
+ *	hardware level, but not serviced yet, as this might deadlock when
+ *	called with interrupts disabled and the target CPU of the interrupt
+ *	is the current CPU.
  */
 bool synchronize_hardirq(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
 	if (desc) {
-		__synchronize_hardirq(desc);
+		__synchronize_hardirq(desc, false);
 		return !atomic_read(&desc->threads_active);
 	}
 
@@ -95,14 +116,19 @@ EXPORT_SYMBOL(synchronize_hardirq);
  *	to complete before returning. If you use this function while
  *	holding a resource the IRQ handler may need you will deadlock.
  *
- *	This function may be called - with care - from IRQ context.
+ *	Can only be called from preemptible code as it might sleep when
+ *	an interrupt thread is associated to @irq.
+ *
+ *	It optionally makes sure (when the irq chip supports that method)
+ *	that the interrupt is not pending in any CPU and waiting for
+ *	service.
  */
 void synchronize_irq(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
 	if (desc) {
-		__synchronize_hardirq(desc);
+		__synchronize_hardirq(desc, true);
 		/*
 		 * We made sure that no hardirq handler is
 		 * running. Now verify that no threaded handlers are
@@ -1699,6 +1725,7 @@ static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
 	/* If this was the last handler, shut down the IRQ line: */
 	if (!desc->action) {
 		irq_settings_clr_disable_unlazy(desc);
+		/* Only shutdown. Deactivate after synchronize_hardirq() */
 		irq_shutdown(desc);
 	}
 
@@ -1727,8 +1754,12 @@ static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
 
 	unregister_handler_proc(irq, action);
 
-	/* Make sure it's not being used on another CPU: */
-	synchronize_hardirq(irq);
+	/*
+	 * Make sure it's not being used on another CPU and if the chip
+	 * supports it also make sure that there is no (not yet serviced)
+	 * interrupt in flight at the hardware level.
+	 */
+	__synchronize_hardirq(desc, true);
 
 #ifdef CONFIG_DEBUG_SHIRQ
 	/*
@@ -1768,6 +1799,14 @@ static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
 		 * require it to deallocate resources over the slow bus.
 		 */
 		chip_bus_lock(desc);
+		/*
+		 * There is no interrupt on the fly anymore. Deactivate it
+		 * completely.
+		 */
+		raw_spin_lock_irqsave(&desc->lock, flags);
+		irq_domain_deactivate_irq(&desc->irq_data);
+		raw_spin_unlock_irqrestore(&desc->lock, flags);
+
 		irq_release_resources(desc);
 		chip_bus_sync_unlock(desc);
 		irq_remove_timings(desc);
@@ -1855,7 +1894,7 @@ static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
 	}
 
 	irq_settings_clr_disable_unlazy(desc);
-	irq_shutdown(desc);
+	irq_shutdown_and_deactivate(desc);
 
 	irq_release_resources(desc);
 
@@ -2578,6 +2617,28 @@ out:
 	irq_put_desc_unlock(desc, flags);
 }
 
+int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
+			    bool *state)
+{
+	struct irq_chip *chip;
+	int err = -EINVAL;
+
+	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);
+	return err;
+}
+
 /**
  *	irq_get_irqchip_state - returns the irqchip state of a interrupt.
  *	@irq: Interrupt line that is forwarded to a VM
@@ -2596,7 +2657,6 @@ int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
 {
 	struct irq_desc *desc;
 	struct irq_data *data;
-	struct irq_chip *chip;
 	unsigned long flags;
 	int err = -EINVAL;
 
@@ -2606,19 +2666,7 @@ int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
 
 	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);
+	err = __irq_get_irqchip_state(data, which, state);
 
 	irq_put_desc_busunlock(desc, flags);
 	return err;