genirq: Add irq_chip_(enable/disable)_parent

Add helper irq_chip_enable_parent and irq_chip_disable_parent. The
helper implement the default behavior in case irq_enable or irq_disable
is not implemented for the parent interrupt chip, which is calling the
irq_mask or irq_unmask respectively.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Cc: marc.zyngier@arm.com
Cc: linux@arm.linux.org.uk
Cc: u.kleine-koenig@pengutronix.de
Cc: olof@lixom.net
Cc: arnd@arndb.de
Cc: daniel.lezcano@linaro.org
Cc: mark.rutland@arm.com
Cc: pawel.moll@arm.com
Cc: robh+dt@kernel.org
Cc: ijc+devicetree@hellion.org.uk
Cc: galak@codeaurora.org
Cc: mcoquelin.stm32@gmail.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: shawn.guo@linaro.org
Cc: kernel@pengutronix.de
Cc: jason@lakedaemon.net
Link: http://lkml.kernel.org/r/1431769465-26867-3-git-send-email-stefan@agner.ch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/irq.h

@@ -458,6 +458,8 @@ extern void handle_nested_irq(unsigned int irq);
 
 extern int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg);
 #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+extern void irq_chip_enable_parent(struct irq_data *data);
+extern void irq_chip_disable_parent(struct irq_data *data);
 extern void irq_chip_ack_parent(struct irq_data *data);
 extern int irq_chip_retrigger_hierarchy(struct irq_data *data);
 extern void irq_chip_mask_parent(struct irq_data *data);

kernel/irq/chip.c

@@ -875,6 +875,34 @@ void irq_cpu_offline(void)
 }
 
 #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+/**
+ * irq_chip_enable_parent - Enable the parent interrupt (defaults to unmask if
+ * NULL)
+ * @data:	Pointer to interrupt specific data
+ */
+void irq_chip_enable_parent(struct irq_data *data)
+{
+	data = data->parent_data;
+	if (data->chip->irq_enable)
+		data->chip->irq_enable(data);
+	else
+		data->chip->irq_unmask(data);
+}
+
+/**
+ * irq_chip_disable_parent - Disable the parent interrupt (defaults to mask if
+ * NULL)
+ * @data:	Pointer to interrupt specific data
+ */
+void irq_chip_disable_parent(struct irq_data *data)
+{
+	data = data->parent_data;
+	if (data->chip->irq_disable)
+		data->chip->irq_disable(data);
+	else
+		data->chip->irq_mask(data);
+}
+
 /**
  * irq_chip_ack_parent - Acknowledge the parent interrupt
  * @data:	Pointer to interrupt specific data