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>

1 files changed, 28 insertions, 0 deletions

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