1 files changed, 10 insertions, 6 deletions

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 632b13e10053..bf96f1b5c6ec 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -65,18 +65,21 @@ static int machine_has_topology_irq;
 static struct timer_list topology_timer;
 static void set_topology_timer(void);
 static DECLARE_WORK(topology_work, topology_work_fn);
+/* topology_lock protects the core linked list */
+static DEFINE_SPINLOCK(topology_lock);
 
 cpumask_t cpu_core_map[NR_CPUS];
 
 cpumask_t cpu_coregroup_map(unsigned int cpu)
 {
 	struct core_info *core = &core_info;
+	unsigned long flags;
 	cpumask_t mask;
 
 	cpus_clear(mask);
 	if (!machine_has_topology)
 		return cpu_present_map;
-	mutex_lock(&smp_cpu_state_mutex);
+	spin_lock_irqsave(&topology_lock, flags);
 	while (core) {
 		if (cpu_isset(cpu, core->mask)) {
 			mask = core->mask;
@@ -84,7 +87,7 @@ cpumask_t cpu_coregroup_map(unsigned int cpu)
 		}
 		core = core->next;
 	}
-	mutex_unlock(&smp_cpu_state_mutex);
+	spin_unlock_irqrestore(&topology_lock, flags);
 	if (cpus_empty(mask))
 		mask = cpumask_of_cpu(cpu);
 	return mask;
@@ -133,7 +136,7 @@ static void tl_to_cores(struct tl_info *info)
 	union tl_entry *tle, *end;
 	struct core_info *core = &core_info;
 
-	mutex_lock(&smp_cpu_state_mutex);
+	spin_lock_irq(&topology_lock);
 	clear_cores();
 	tle = info->tle;
 	end = (union tl_entry *)((unsigned long)info + info->length);
@@ -157,7 +160,7 @@ static void tl_to_cores(struct tl_info *info)
 		}
 		tle = next_tle(tle);
 	}
-	mutex_unlock(&smp_cpu_state_mutex);
+	spin_unlock_irq(&topology_lock);
 }
 
 static void topology_update_polarization_simple(void)
@@ -209,7 +212,7 @@ static void update_cpu_core_map(void)
 		cpu_core_map[cpu] = cpu_coregroup_map(cpu);
 }
 
-void arch_update_cpu_topology(void)
+int arch_update_cpu_topology(void)
 {
 	struct tl_info *info = tl_info;
 	struct sys_device *sysdev;
@@ -218,7 +221,7 @@ void arch_update_cpu_topology(void)
 	if (!machine_has_topology) {
 		update_cpu_core_map();
 		topology_update_polarization_simple();
-		return;
+		return 0;
 	}
 	stsi(info, 15, 1, 2);
 	tl_to_cores(info);
@@ -227,6 +230,7 @@ void arch_update_cpu_topology(void)
 		sysdev = get_cpu_sysdev(cpu);
 		kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
 	}
+	return 1;
 }
 
 static void topology_work_fn(struct work_struct *work)