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>

1 files changed, 17 insertions, 5 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 63ae00ec72ff..9df50c74162c 100644
--- 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;
 }