of: to support binding numa node to specified device in devicetree

For now, in function device_add, the new device will be forced to
inherit the numa node of its parent. But this will override the device's
numa node which configured in devicetree.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/base/core.c

@@ -1066,7 +1066,7 @@ int device_add(struct device *dev)
 		dev->kobj.parent = kobj;
 
 	/* use parent numa_node */
-	if (parent)
+	if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
 		set_dev_node(dev, dev_to_node(parent));
 
 	/* first, register with generic layer. */

drivers/of/device.c

@@ -60,10 +60,11 @@ int of_device_add(struct platform_device *ofdev)
 	ofdev->name = dev_name(&ofdev->dev);
 	ofdev->id = -1;
 
-	/* device_add will assume that this device is on the same node as
-	 * the parent. If there is no parent defined, set the node
-	 * explicitly */
-	if (!ofdev->dev.parent)
+	/*
+	 * If this device has not binding numa node in devicetree, that is
+	 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
+	 * device is on the same node as the parent.
+	 */
 	set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
 
 	return device_add(&ofdev->dev);