powerpc/numa: Look up device node in of_get_assoc_arrays()

Look up the device node for the associativity array property instead
of having it passed in as a parameter. This changes precedes an update
in which the calling routines for of_get_assoc_arrays() will not have
the device node pointer to pass in.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/numa.c

@@ -466,19 +466,27 @@ struct assoc_arrays {
  * indicating the size of each associativity array, followed by a list
  * of N associativity arrays.
  */
-static int of_get_assoc_arrays(struct device_node *memory,
-			       struct assoc_arrays *aa)
+static int of_get_assoc_arrays(struct assoc_arrays *aa)
 {
+	struct device_node *memory;
 	const __be32 *prop;
 	u32 len;
 
+	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (!memory)
+		return -1;
+
 	prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
-	if (!prop || len < 2 * sizeof(unsigned int))
+	if (!prop || len < 2 * sizeof(unsigned int)) {
+		of_node_put(memory);
 		return -1;
+	}
 
 	aa->n_arrays = of_read_number(prop++, 1);
 	aa->array_sz = of_read_number(prop++, 1);
 
+	of_node_put(memory);
+
 	/* Now that we know the number of arrays and size of each array,
 	 * revalidate the size of the property read in.
 	 */
@@ -661,7 +669,7 @@ static void __init parse_drconf_memory(struct device_node *memory)
 	if (!lmb_size)
 		return;
 
-	rc = of_get_assoc_arrays(memory, &aa);
+	rc = of_get_assoc_arrays(&aa);
 	if (rc)
 		return;
 
@@ -996,7 +1004,7 @@ static int hot_add_drconf_scn_to_nid(struct device_node *memory,
 	if (!lmb_size)
 		return -1;
 
-	rc = of_get_assoc_arrays(memory, &aa);
+	rc = of_get_assoc_arrays(&aa);
 	if (rc)
 		return -1;