diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 3e16fe08150e..e759109abb36 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -462,19 +462,6 @@ void online_page(struct page *page)
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-/*
- * XXX: memory_add_physaddr_to_nid() is to find node id from physical address
- *	via probe interface of sysfs. If acpi notifies hot-add event, then it
- *	can tell node id by searching dsdt. But, probe interface doesn't have
- *	node id. So, return 0 as node id at this time.
- */
-#ifdef CONFIG_NUMA
-int memory_add_physaddr_to_nid(u64 start)
-{
-	return 0;
-}
-#endif
-
 /*
  * Memory is added always to NORMAL zone. This means you will never get
  * additional DMA/DMA32 memory.
@@ -506,6 +493,13 @@ int remove_memory(u64 start, u64 size)
 }
 EXPORT_SYMBOL_GPL(remove_memory);
 
+#ifndef CONFIG_ACPI_NUMA
+int memory_add_physaddr_to_nid(u64 start)
+{
+	return 0;
+}
+#endif
+
 #else /* CONFIG_MEMORY_HOTPLUG */
 /*
  * Memory Hotadd without sparsemem. The mem_maps have been allocated in advance,
diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c
index 19396a261e8d..8491300ef909 100644
--- a/arch/x86_64/mm/srat.c
+++ b/arch/x86_64/mm/srat.c
@@ -27,7 +27,7 @@ static struct acpi_table_slit *acpi_slit;
 
 static nodemask_t nodes_parsed __initdata;
 static struct bootnode nodes[MAX_NUMNODES] __initdata;
-static struct bootnode nodes_add[MAX_NUMNODES] __initdata;
+static struct bootnode nodes_add[MAX_NUMNODES];
 static int found_add_area __initdata;
 int hotadd_percent __initdata = 0;
 
@@ -466,3 +466,14 @@ int __node_distance(int a, int b)
 }
 
 EXPORT_SYMBOL(__node_distance);
+
+int memory_add_physaddr_to_nid(u64 start)
+{
+	int i, ret = 0;
+
+	for_each_node(i)
+		if (nodes_add[i].start <= start && nodes_add[i].end > start)
+			ret = i;
+
+	return ret;
+}