From 85f08c17de26f117be6ca7aa260d2ec02a2248ba Mon Sep 17 00:00:00 2001
From: Jiang Liu <jiang.liu@linux.intel.com>
Date: Thu, 6 Nov 2014 22:20:16 +0800
Subject: [PATCH] genirq: Introduce helper functions to support stacked
 irq_chip

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

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 include/linux/irq.h |  5 +++++
 kernel/irq/chip.c   | 28 ++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 13ba412ce3a0..0adcbbbf2e87 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -443,6 +443,11 @@ 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 72a93086216b..dd1d3c4c93a2 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -850,3 +850,31 @@ void irq_cpu_offline(void)
 		raw_spin_unlock_irqrestore(&desc->lock, flags);
 	}
 }
+
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+/**
+ * irq_chip_ack_parent - Acknowledge the parent interrupt
+ * @data:	Pointer to interrupt specific data
+ */
+void irq_chip_ack_parent(struct irq_data *data)
+{
+	data = data->parent_data;
+	data->chip->irq_ack(data);
+}
+
+/**
+ * irq_chip_retrigger_hierarchy - Retrigger an interrupt in hardware
+ * @data:	Pointer to interrupt specific data
+ *
+ * Iterate through the domain hierarchy of the interrupt and check
+ * whether a hw retrigger function exists. If yes, invoke it.
+ */
+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