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>

2 files changed, 13 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
index afe4aaa65c3b..aed188bd70db 100644
--- a/arch/powerpc/include/asm/topology.h
+++ b/arch/powerpc/include/asm/topology.h
@@ -93,6 +93,8 @@ extern void __init dump_numa_cpu_topology(void);
 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 void sysfs_remove_device_from_node(struct sys_device *dev,
 {
 }
 
+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>
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 8fe8bc61c10a..2097f2b3cba8 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -41,6 +41,7 @@
 #include <asm/atomic.h>
 #include <asm/time.h>
 #include <asm/mmu.h>
+#include <asm/topology.h>
 
 struct rtas_t rtas = {
         .lock = __ARCH_SPIN_LOCK_UNLOCKED
@@ -713,6 +714,7 @@ static int __rtas_suspend_last_cpu(struct rtas_suspend_me_data *data, int wake_w
         int cpu;
 
         slb_set_size(SLB_MIN_SIZE);
+        stop_topology_update();
         printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n", smp_processor_id());
 
         while (rc == H_MULTI_THREADS_ACTIVE && !atomic_read(&data->done) &&
@@ -728,6 +730,7 @@ static int __rtas_suspend_last_cpu(struct rtas_suspend_me_data *data, int wake_w
                 rc = atomic_read(&data->error);
 
         atomic_set(&data->error, rc);
+        start_topology_update();
 
         if (wake_when_done) {
                 atomic_set(&data->done, 1);