Re: [PATCH] powerpc/mobility: Extend start/stop topology update scope

The PPC mobility code may receive RTAS requests to perform PRRN
topology changes at any time, including during LPAR migration
operations.  In some configurations where the affinity of CPUs
or memory is being changed on that platform, the PRRN requests
may apply or refer to outdated information prior to the complete
update of the device-tree.  This patch changes the duration for
which topology updates are suppressed during LPAR migrations from
just the rtas_ibm_suspend_me / 'ibm,suspend-me' call(s) to cover
the entire 'migration_store' operation to allow all changes to
the device-tree to be applied prior to accepting and applying any
PRRN requests.

For tracking purposes, pr_info notices are added to the functions
start_topology_update() and stop_topology_update() of 'numa.c'.

Signed-off-by: Michael Bringmann <redacted>
---
 arch/powerpc/kernel/rtas.c                |    4 ----
 arch/powerpc/mm/numa.c                    |    6 ++++++
 arch/powerpc/platforms/pseries/mobility.c |    5 +++++
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 8afd146..28d8b57 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c

@@ -981,8 +981,6 @@ int rtas_ibm_suspend_me(u64 handle)
 		goto out;
 	}
 
-	stop_topology_update();
-
 	/* Call function on all CPUs.  One of us will make the
 	 * rtas call
 	 */