[RFC Part2 v1 02/21] genirq: Introduce helper functions to support stacked irq_chip

[Jiang Liu <jiang.liu@linux.intel.com>]

Now we already support hierarchy irq_datas, so introduce several helpers
to support stacked irq_chips.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
 include/linux/irq.h |    5 +++++
 kernel/irq/chip.c   |   18 ++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 4b74565690ce..bfa027f6814a 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -433,6 +433,11 @@ extern void handle_percpu_devid_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_bad_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_nested_irq(unsigned int irq);
 
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+extern void irq_chip_ack_parent(struct irq_data *data);
+extern int irq_chip_retrigger_hierarchy(struct irq_data *data);
+#endif
+
 /* Handling of unhandled and spurious interrupts: */
 extern void note_interrupt(unsigned int irq, struct irq_desc *desc,
 			   irqreturn_t action_ret);
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 46bd5e2190c3..b8ee27efde73 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -821,3 +821,21 @@ void irq_cpu_offline(void)
 		raw_spin_unlock_irqrestore(&desc->lock, flags);
 	}
 }
+
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+void irq_chip_ack_parent(struct irq_data *data)
+{
+	data = data->parent_data;
+	if (data && data->chip && data->chip->irq_ack)
+		data->chip->irq_ack(data);
+}
+
+int irq_chip_retrigger_hierarchy(struct irq_data *data)
+{
+	for (data = data->parent_data; data; data = data->parent_data)
+		if (data->chip && data->chip->irq_retrigger)
+			return data->chip->irq_retrigger(data);
+
+	return -ENOSYS;
+}
+#endif
-- 
1.7.10.4