powerpc: Disable VPHN polling during a suspend operation

Tie the polling mechanism into the ibm,suspend-me rtas call to
stop/restart polling before/after a suspend, hibernate, migrate,
or checkpoint restart operation. This ensures that the system has a
chance to disable the polling if the partition is migrated to a system
that does not support VPHN (and vice versa).

Signed-off-by: Jesse Larrew <jlarrew@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
index afe4aaa..aed188b 100644
--- a/arch/powerpc/include/asm/topology.h
+++ b/arch/powerpc/include/asm/topology.h
@@ -93,6 +93,8 @@
 extern int sysfs_add_device_to_node(struct sys_device *dev, int nid);
 extern void sysfs_remove_device_from_node(struct sys_device *dev, int nid);
 
+extern int start_topology_update(void);
+extern int stop_topology_update(void);
 #else
 
 static inline void dump_numa_cpu_topology(void) {}
@@ -107,6 +109,14 @@
 {
 }
 
+static inline int start_topology_update(void)
+{
+	return 0;
+}
+static inline int stop_topology_update(void)
+{
+	return 0;
+}
 #endif /* CONFIG_NUMA */
 
 #include <asm-generic/topology.h>