2 files changed, 51 insertions, 20 deletions

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 12d5f972f23f..cba442ec3c66 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -9,6 +9,7 @@
 
 
 extern void synchronize_irq(unsigned int irq);
+extern void synchronize_hardirq(unsigned int irq);
 
 #if defined(CONFIG_TINY_RCU)
 
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 481a13c43b17..274ba9238fb7 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -32,24 +32,10 @@ static int __init setup_forced_irqthreads(char *arg)
 early_param("threadirqs", setup_forced_irqthreads);
 #endif
 
-/**
- *	synchronize_irq - wait for pending IRQ handlers (on other CPUs)
- *	@irq: interrupt number to wait for
- *
- *	This function waits for any pending IRQ handlers for this interrupt
- *	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.
- */
-void synchronize_irq(unsigned int irq)
+static void __synchronize_hardirq(struct irq_desc *desc)
 {
-	struct irq_desc *desc = irq_to_desc(irq);
 	bool inprogress;
 
-	if (!desc)
-		return;
-
 	do {
 		unsigned long flags;
 
@@ -67,12 +53,56 @@ void synchronize_irq(unsigned int irq)
 
 		/* Oops, that failed? */
 	} while (inprogress);
+}
 
-	/*
-	 * We made sure that no hardirq handler is running. Now verify
-	 * that no threaded handlers are active.
-	 */
-	wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
+/**
+ *	synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
+ *	@irq: interrupt number to wait for
+ *
+ *	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 IRQ handler may need you
+ *	will deadlock. It does not take associated threaded handlers
+ *	into account.
+ *
+ *	Do not use this for shutdown scenarios where you must be sure
+ *	that all parts (hardirq and threaded handler) have completed.
+ *
+ *	This function may be called - with care - from IRQ context.
+ */
+void synchronize_hardirq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (desc)
+		__synchronize_hardirq(desc);
+}
+EXPORT_SYMBOL(synchronize_hardirq);
+
+/**
+ *	synchronize_irq - wait for pending IRQ handlers (on other CPUs)
+ *	@irq: interrupt number to wait for
+ *
+ *	This function waits for any pending IRQ handlers for this interrupt
+ *	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.
+ */
+void synchronize_irq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (desc) {
+		__synchronize_hardirq(desc);
+		/*
+		 * We made sure that no hardirq handler is
+		 * running. Now verify that no threaded handlers are
+		 * active.
+		 */
+		wait_event(desc->wait_for_threads,
+			   !atomic_read(&desc->threads_active));
+	}
 }
 EXPORT_SYMBOL(synchronize_irq);