of: implement of_node_to_nid as a weak function

Implement of_node_to_nid as weak function to remove the dependency on
asm/prom.h. This is in preparation to make prom.h optional.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@linaro.org>

arch/powerpc/include/asm/prom.h

@@ -42,13 +42,6 @@ extern void kdump_move_device_tree(void);
 /* cache lookup */
 struct device_node *of_find_next_cache_node(struct device_node *np);
 
-#ifdef CONFIG_NUMA
-extern int of_node_to_nid(struct device_node *device);
-#else
-static inline int of_node_to_nid(struct device_node *device) { return 0; }
-#endif
-#define of_node_to_nid of_node_to_nid
-
 extern void of_instantiate_rtc(void);
 
 extern int of_get_ibm_chip_id(struct device_node *np);

arch/sparc/include/asm/prom.h

@@ -43,10 +43,6 @@ extern int of_getintprop_default(struct device_node *np,
 				 const char *name,
 				 int def);
 extern int of_find_in_proplist(const char *list, const char *match, int len);
-#ifdef CONFIG_NUMA
-extern int of_node_to_nid(struct device_node *dp);
-#define of_node_to_nid of_node_to_nid
-#endif
 
 extern void prom_build_devicetree(void);
 extern void of_populate_present_mask(void);

drivers/of/base.c

@@ -74,6 +74,13 @@ int of_n_size_cells(struct device_node *np)
 }
 EXPORT_SYMBOL(of_n_size_cells);
 
+#ifdef CONFIG_NUMA
+int __weak of_node_to_nid(struct device_node *np)
+{
+	return numa_node_id();
+}
+#endif
+
 #if defined(CONFIG_OF_DYNAMIC)
 /**
  *	of_node_get - Increment refcount of a node

include/linux/of.h

@@ -534,13 +534,10 @@ static inline const char *of_prop_next_string(struct property *prop,
 #define of_match_node(_matches, _node)	NULL
 #endif /* CONFIG_OF */
 
-#ifndef of_node_to_nid
-static inline int of_node_to_nid(struct device_node *np)
-{
-	return numa_node_id();
-}
-
-#define of_node_to_nid of_node_to_nid
+#if defined(CONFIG_OF) && defined(CONFIG_NUMA)
+extern int of_node_to_nid(struct device_node *np);
+#else
+static inline int of_node_to_nid(struct device_node *device) { return 0; }
 #endif
 
 /**