powerpc/pseries/mobility: Extend start/stop topology update scope
authorMichael Bringmann <mwb@linux.vnet.ibm.com>
Tue, 9 Oct 2018 20:12:14 +0000 (15:12 -0500)
committerMichael Ellerman <mpe@ellerman.id.au>
Sat, 13 Oct 2018 11:21:25 +0000 (22:21 +1100)
commit65b9fdadfc4d87e2577b791fb3495cd39c93d8c0
treee12ee844c47f127a9271e356a95b2de7725ca99d
parent960e30029863db95ec79a71009272d4661db5991
powerpc/pseries/mobility: Extend start/stop topology update scope

The powerpc mobility code may receive RTAS requests to perform PRRN
(Platform Resource Reassignment Notification) 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outdated information prior to the complete update of the device-tree.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 <mwb@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/kernel/rtas.c
arch/powerpc/mm/numa.c
arch/powerpc/platforms/pseries/mobility.c