From 9cc61906d3ef919a9c72749fe0ca960753b4c6a1 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Tue, 3 Aug 2021 16:16:16 +0200
Subject: [PATCH] smpboot: Replace deprecated CPU-hotplug functions.

References: bsc#1189998 (PREEMPT_RT prerequisite backports)
Patch-mainline: v5.15-rc1
Git-commit: 844d87871b6e0ac3ceb177535dcdf6e6a9f1fd4b

The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210803141621.780504-34-bigeasy@linutronix.de
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 kernel/smpboot.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index cf6acab78538..f6bc0bc8a2aa 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -291,7 +291,7 @@ int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
 	unsigned int cpu;
 	int ret = 0;
 
-	get_online_cpus();
+	cpus_read_lock();
 	mutex_lock(&smpboot_threads_lock);
 	for_each_online_cpu(cpu) {
 		ret = __smpboot_create_thread(plug_thread, cpu);
@@ -304,7 +304,7 @@ int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
 	list_add(&plug_thread->list, &hotplug_threads);
 out:
 	mutex_unlock(&smpboot_threads_lock);
-	put_online_cpus();
+	cpus_read_unlock();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread);
@@ -317,12 +317,12 @@ EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread);
  */
 void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread)
 {
-	get_online_cpus();
+	cpus_read_lock();
 	mutex_lock(&smpboot_threads_lock);
 	list_del(&plug_thread->list);
 	smpboot_destroy_threads(plug_thread);
 	mutex_unlock(&smpboot_threads_lock);
-	put_online_cpus();
+	cpus_read_unlock();
 }
 EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread);