of: Create unlocked version of for_each_child_of_node()

When iterating over nodes, sometimes it needs to be done when the DT
lock is already held. This patch makes an unlocked version of the
for_each_child_of_node() macro.

Signed-off-by: Grant Likely <grant.likely@linaro.org>

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 63ae00ec72ff868e41fde00885bd82cb720d6694..9df50c74162c41869a17320c2fdf03758854d377 100644 (file)
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -695,6 +695,22 @@ struct device_node *of_get_next_parent(struct device_node *node)
 }
 EXPORT_SYMBOL(of_get_next_parent);
 
+static struct device_node *__of_get_next_child(const struct device_node *node,
+                                               struct device_node *prev)
+{
+       struct device_node *next;
+
+       next = prev ? prev->sibling : node->child;
+       for (; next; next = next->sibling)
+               if (of_node_get(next))
+                       break;
+       of_node_put(prev);
+       return next;
+}
+#define __for_each_child_of_node(parent, child) \
+       for (child = __of_get_next_child(parent, NULL); child != NULL; \
+            child = __of_get_next_child(parent, child))
+
 /**
  *     of_get_next_child - Iterate a node childs
  *     @node:  parent node
@@ -710,11 +726,7 @@ struct device_node *of_get_next_child(const struct device_node *node,
        unsigned long flags;
 
        raw_spin_lock_irqsave(&devtree_lock, flags);
-       next = prev ? prev->sibling : node->child;
-       for (; next; next = next->sibling)
-               if (of_node_get(next))
-                       break;
-       of_node_put(prev);
+       next = __of_get_next_child(node, prev);
        raw_spin_unlock_irqrestore(&devtree_lock, flags);
        return next;
 }