From d1099e2276df1d8dd4037552c2f34eb4c4df4a75 Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Wed, 5 Jul 2023 16:51:43 +0200
Subject: [PATCH 10/10] powerpc/pseries: Honour current SMT state when DLPAR
onlining CPUs
References: bsc#1214285 bsc#1205462 ltc#200161 ltc#200588
Patch-mainline: v6.6-rc1
Git-commit: d1099e2276df1d8dd4037552c2f34eb4c4df4a75
Integrate with the generic SMT support, so that when a CPU is DLPAR
onlined it is brought up with the correct SMT mode.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230705145143.40545-11-ldufour@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/platforms/pseries/hotplug-cpu.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -398,6 +398,14 @@ static int dlpar_online_cpu(struct device_node *dn)
for_each_present_cpu(cpu) {
if (get_hard_smp_processor_id(cpu) != thread)
continue;
+
+ if (!topology_is_primary_thread(cpu)) {
+ if (cpu_smt_control != CPU_SMT_ENABLED)
+ break;
+ if (!topology_smt_thread_allowed(cpu))
+ break;
+ }
+
cpu_maps_update_done();
find_and_online_cpu_nid(cpu);
rc = device_online(get_cpu_device(cpu));
--
2.41.0