powerpc/pseries: Add /proc interface to control topology updates

There are instances in which we do not want topology updates to occur.
In order to allow this a /proc interface (/proc/powerpc/topology_updates)
is introduced so that topology updates can be enabled and disabled.

This patch also adds a prrn_is_enabled() call so that PRRN events are
handled in the kernel only if topology updating is enabled.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
index 852ed1b384f6..161ab662843b 100644
--- a/arch/powerpc/include/asm/topology.h
+++ b/arch/powerpc/include/asm/topology.h
@@ -71,6 +71,7 @@ static inline void sysfs_remove_device_from_node(struct device *dev,
 #if defined(CONFIG_NUMA) && defined(CONFIG_PPC_SPLPAR)
 extern int start_topology_update(void);
 extern int stop_topology_update(void);
+extern int prrn_is_enabled(void);
 #else
 static inline int start_topology_update(void)
 {
@@ -80,6 +81,10 @@ static inline int stop_topology_update(void)
 {
         return 0;
 }
+static inline int prrn_is_enabled(void)
+{
+        return 0;
+}
 #endif /* CONFIG_NUMA && CONFIG_PPC_SPLPAR */
 
 #include <asm-generic/topology.h>