Merge tag 'devicetree-fixes-for-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull devicetree fixes from Rob Herring:

 - Fix handling of GICv5 ITS MSI properties on platforms with
   'msi-parent' as well as a of_node refcounting fix.

   This is also preparation for further refactoring in 6.19 to use
   common DT parsing of MSI properties.

* tag 'devicetree-fixes-for-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of/irq: Export of_msi_xlate() for module usage
  of/irq: Fix OF node refcount in of_msi_get_domain()
  of/irq: Add msi-parent check to of_msi_xlate()

Author: torvalds

drivers/of/irq.c

@@ -671,14 +671,44 @@ void __init of_irq_init(const struct of_device_id *matches)
 	}
 }
 
+static int of_check_msi_parent(struct device_node *dev_node, struct device_node **msi_node)
+{
+	struct of_phandle_args msi_spec;
+	int ret;
+
+	/*
+	 * An msi-parent phandle with a missing or == 0 #msi-cells
+	 * property identifies a 1:1 ID translation mapping.
+	 *
+	 * Set the msi controller node if the firmware matches this
+	 * condition.
+	 */
+	ret = of_parse_phandle_with_optional_args(dev_node, "msi-parent", "#msi-cells",
+						  0, &msi_spec);
+	if (ret)
+		return ret;
+
+	if ((*msi_node && *msi_node != msi_spec.np) || msi_spec.args_count != 0)
+		ret = -EINVAL;
+
+	if (!ret) {
+		/* Return with a node reference held */
+		*msi_node = msi_spec.np;
+		return 0;
+	}
+	of_node_put(msi_spec.np);
+
+	return ret;
+}
+
 /**
  * of_msi_xlate - map a MSI ID and find relevant MSI controller node
  * @dev: device for which the mapping is to be done.
  * @msi_np: Pointer to target MSI controller node
  * @id_in: Device ID.
  *
  * Walk up the device hierarchy looking for devices with a "msi-map"
- * property. If found, apply the mapping to @id_in.
+ * or "msi-parent" property. If found, apply the mapping to @id_in.
  * If @msi_np points to a non-NULL device node pointer, only entries targeting
  * that node will be matched; if it points to a NULL value, it will receive the
  * device node of the first matching target phandle, with a reference held.
@@ -692,14 +722,18 @@ u32 of_msi_xlate(struct device *dev, struct device_node **msi_np, u32 id_in)
 
 	/*
 	 * Walk up the device parent links looking for one with a
-	 * "msi-map" property.
+	 * "msi-map" or an "msi-parent" property.
 	 */
-	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent)
+	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
 		if (!of_map_id(parent_dev->of_node, id_in, "msi-map",
 				"msi-map-mask", msi_np, &id_out))
 			break;
+		if (!of_check_msi_parent(parent_dev->of_node, msi_np))
+			break;
+	}
 	return id_out;
 }
+EXPORT_SYMBOL_GPL(of_msi_xlate);
 
 /**
  * of_msi_map_get_device_domain - Use msi-map to find the relevant MSI domain
@@ -741,8 +775,10 @@ struct irq_domain *of_msi_get_domain(struct device *dev,
 
 	of_for_each_phandle(&it, err, np, "msi-parent", "#msi-cells", 0) {
 		d = irq_find_matching_host(it.node, token);
-		if (d)
+		if (d) {
+			of_node_put(it.node);
 			return d;
+		}
 	}
 
 	return NULL;