Plug the irq_populate_fwspec_info() helper into the OF layer
to offer an IRQ affinity reporting function.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/of/irq.c       | 20 ++++++++++++++++++++
 include/linux/of_irq.h |  7 +++++++
 2 files changed, 27 insertions(+)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 74aaea61de13c..cb264f44bd6d8 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -479,6 +479,26 @@ int of_irq_get(struct device_node *dev, int index)
 }
 EXPORT_SYMBOL_GPL(of_irq_get);
 
+const struct cpumask *of_irq_get_affinity(struct device_node *dev, int index)
+{
+	int rc;
+	struct of_phandle_args oirq;
+	struct irq_fwspec_info info;
+
+	rc = of_irq_parse_one(dev, index, &oirq);
+	if (rc)
+		return NULL;
+
+	of_phandle_args_to_fwspec(oirq.np, oirq.args, oirq.args_count,
+				  &info.fwspec);
+
+	if (!irq_populate_fwspec_info(&info) &&
+	    info.flags & IRQ_FWSPEC_INFO_AFFINITY_VALID)
+		return info.affinity;
+
+	return NULL;
+}
+
 /**
  * of_irq_get_byname - Decode a node's IRQ and return it as a Linux IRQ number
  * @dev: pointer to device tree node
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index a480063c9cb19..721cbdbc292df 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -43,6 +43,8 @@ extern int of_irq_parse_one(struct device_node *device, int index,
 			  struct of_phandle_args *out_irq);
 extern int of_irq_count(struct device_node *dev);
 extern int of_irq_get(struct device_node *dev, int index);
+extern const struct cpumask *of_irq_get_affinity(struct device_node *dev,
+						      int index);
 extern int of_irq_get_byname(struct device_node *dev, const char *name);
 extern int of_irq_to_resource_table(struct device_node *dev,
 		struct resource *res, int nr_irqs);
@@ -77,6 +79,11 @@ static inline int of_irq_get_byname(struct device_node *dev, const char *name)
 {
 	return 0;
 }
+static inline const struct cpumask *of_irq_get_affinity(struct device_node *dev,
+							int index)
+{
+	return NULL;
+}
 static inline int of_irq_to_resource_table(struct device_node *dev,
 					   struct resource *res, int nr_irqs)
 {
-- 
2.39.2