From 588a079ebd6297dc225c8bba717a71a8065e1a4b Mon Sep 17 00:00:00 2001
From: Heiko Carstens <hca@linux.ibm.com>
Date: Wed, 17 Feb 2021 07:10:46 +0100
Subject: [PATCH] s390/smp: consolidate locking for smp_rescan()
Move locking to __smp_rescan() instead of duplicating it to all call sites.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
arch/s390/kernel/smp.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index e299892440b6d..9fa85c927a0ce 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -780,6 +780,8 @@ static int __smp_rescan_cpus(struct sclp_core_info *info, bool early)
u16 core_id;
int nr, i;
+ get_online_cpus();
+ mutex_lock(&smp_cpu_state_mutex);
nr = 0;
cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
/*
@@ -800,6 +802,8 @@ static int __smp_rescan_cpus(struct sclp_core_info *info, bool early)
configured = i < info->configured;
nr += smp_add_core(&info->core[i], &avail, configured, early);
}
+ mutex_unlock(&smp_cpu_state_mutex);
+ put_online_cpus();
return nr;
}
@@ -847,9 +851,7 @@ void __init smp_detect_cpus(void)
pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
/* Add CPUs present at boot */
- get_online_cpus();
__smp_rescan_cpus(info, true);
- put_online_cpus();
memblock_free_early((unsigned long)info, sizeof(*info));
}
@@ -1178,11 +1180,7 @@ int __ref smp_rescan_cpus(void)
if (!info)
return -ENOMEM;
smp_get_core_info(info, 0);
- get_online_cpus();
- mutex_lock(&smp_cpu_state_mutex);
nr = __smp_rescan_cpus(info, false);
- mutex_unlock(&smp_cpu_state_mutex);
- put_online_cpus();
kfree(info);
if (nr)
topology_schedule_update();
--
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