of: add __of_add_property() without lock operations

There two places will use the same code for adding one new property to
the DT node. Adding __of_add_property() and prepare for fixing
of_update_property()'s bug.
Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

drivers/of/base.c

@@ -1492,12 +1492,32 @@ static int of_property_notify(int action, struct device_node *np,
 }
 #endif
 
+/**
+ * __of_add_property - Add a property to a node without lock operations
+ */
+static int __of_add_property(struct device_node *np, struct property *prop)
+{
+	struct property **next;
+
+	prop->next = NULL;
+	next = &np->properties;
+	while (*next) {
+		if (strcmp(prop->name, (*next)->name) == 0)
+			/* duplicate ! don't insert it */
+			return -EEXIST;
+
+		next = &(*next)->next;
+	}
+	*next = prop;
+
+	return 0;
+}
+
 /**
  * of_add_property - Add a property to a node
  */
 int of_add_property(struct device_node *np, struct property *prop)
 {
-	struct property **next;
 	unsigned long flags;
 	int rc;
 
@@ -1505,27 +1525,17 @@ int of_add_property(struct device_node *np, struct property *prop)
 	if (rc)
 		return rc;
 
-	prop->next = NULL;
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	next = &np->properties;
-	while (*next) {
-		if (strcmp(prop->name, (*next)->name) == 0) {
-			/* duplicate ! don't insert it */
-			raw_spin_unlock_irqrestore(&devtree_lock, flags);
-			return -1;
-		}
-		next = &(*next)->next;
-	}
-	*next = prop;
+	rc = __of_add_property(np, prop);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
 #ifdef CONFIG_PROC_DEVICETREE
 	/* try to add to proc as well if it was initialized */
-	if (np->pde)
+	if (!rc && np->pde)
 		proc_device_tree_add_prop(np->pde, prop);
 #endif /* CONFIG_PROC_DEVICETREE */
 
-	return 0;
+	return rc;
 }
 
 /**