Subject: [PATCH] powerpc/pseries: avoid harmless preempt warning

From: Nicholas Piggin <[email-masked]>
Date: Sat, 21 Mar 2020 01:24:36 +1000

Signed-off-by: Nicholas Piggin <[email-masked]>
---
 arch/powerpc/platforms/pseries/lpar.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 3c3da25b445c..e4ed5317f117 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -636,8 +636,16 @@ static const struct proc_ops vcpudispatch_stats_freq_proc_ops = {
 
 static int __init vcpudispatch_stats_procfs_init(void)
 {
-	if (!lppaca_shared_proc(get_lppaca()))
+	/*
+	 * Avoid smp_processor_id while preemptible. All CPUs should have
+	 * the same value for lppaca_shared_proc.
+	 */
+	preempt_disable();
+	if (!lppaca_shared_proc(get_lppaca())) {
+		preempt_enable();
 		return 0;
+	}
+	preempt_enable();
 
 	if (!proc_create("powerpc/vcpudispatch_stats", 0600, NULL,
 					&vcpudispatch_stats_proc_ops))
-- 
2.23.0