[PATCH] hot-add-mem x86_64: memory_add_physaddr_to_nid node fixup

In cases where the acpi memory-add event does not containe the pxm (node)
infomation allow the driver to look up node info based on the address.  The
acpi_get_node call returns -1 if it can't decode the pxm info, this causes
add_memory to panic.  acpi_get_node would have to decode the resource from the
handle (a lenghty proposition).  This seems to be the cleanist point to
interject the hook.

[kamezawa.hiroyu@jp.fujitsu.com: build fixes]
[y-goto@jp.fujitsu.com: build fixes]
Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/ia64/mm/numa.c b/arch/ia64/mm/numa.c
index 64e4c21..7807fc5 100644
--- a/arch/ia64/mm/numa.c
+++ b/arch/ia64/mm/numa.c
@@ -16,6 +16,7 @@
 #include <linux/node.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
+#include <linux/module.h>
 #include <asm/mmzone.h>
 #include <asm/numa.h>
 
@@ -69,4 +70,21 @@
 
 	return 0;
 }
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+/*
+ *  SRAT information is stored in node_memblk[], then we can use SRAT
+ *  information at memory-hot-add if necessary.
+ */
+
+int memory_add_physaddr_to_nid(u64 addr)
+{
+	int nid = paddr_to_nid(addr);
+	if (nid < 0)
+		return 0;
+	return nid;
+}
+
+EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
+#endif
 #endif