of: merge of_attach_node() & of_detach_node()

Merge common code between PowerPC and Microblaze

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 71 insertions, 0 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index cf89ee6..2ce58be 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -870,3 +870,74 @@ int prom_update_property(struct device_node *np,
 
 	return 0;
 }
+
+#if defined(CONFIG_OF_DYNAMIC)
+/*
+ * Support for dynamic device trees.
+ *
+ * On some platforms, the device tree can be manipulated at runtime.
+ * The routines in this section support adding, removing and changing
+ * device tree nodes.
+ */
+
+/**
+ * of_attach_node - Plug a device node into the tree and global list.
+ */
+void of_attach_node(struct device_node *np)
+{
+	unsigned long flags;
+
+	write_lock_irqsave(&devtree_lock, flags);
+	np->sibling = np->parent->child;
+	np->allnext = allnodes;
+	np->parent->child = np;
+	allnodes = np;
+	write_unlock_irqrestore(&devtree_lock, flags);
+}
+
+/**
+ * of_detach_node - "Unplug" a node from the device tree.
+ *
+ * The caller must hold a reference to the node.  The memory associated with
+ * the node is not freed until its refcount goes to zero.
+ */
+void of_detach_node(struct device_node *np)
+{
+	struct device_node *parent;
+	unsigned long flags;
+
+	write_lock_irqsave(&devtree_lock, flags);
+
+	parent = np->parent;
+	if (!parent)
+		goto out_unlock;
+
+	if (allnodes == np)
+		allnodes = np->allnext;
+	else {
+		struct device_node *prev;
+		for (prev = allnodes;
+		     prev->allnext != np;
+		     prev = prev->allnext)
+			;
+		prev->allnext = np->allnext;
+	}
+
+	if (parent->child == np)
+		parent->child = np->sibling;
+	else {
+		struct device_node *prevsib;
+		for (prevsib = np->parent->child;
+		     prevsib->sibling != np;
+		     prevsib = prevsib->sibling)
+			;
+		prevsib->sibling = np->sibling;
+	}
+
+	of_node_set_flag(np, OF_DETACHED);
+
+out_unlock:
+	write_unlock_irqrestore(&devtree_lock, flags);
+}
+#endif /* defined(CONFIG_OF_DYNAMIC) */
+