From 29156a065c885d17273cc7bef133f92f663fe7ad Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Fri, 14 Nov 2008 18:18:07 +0100
Subject: [PATCH] --- yaml --- r: 119016 b: refs/heads/master c:
 74af283102b358b0da545460d0d176f473e110f6 h: refs/heads/master v: v3

---
 [refs]                            |  2 +-
 trunk/arch/s390/kernel/topology.c | 11 +++++++----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 73e9001096f9..dd7e1b0d445b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 85acc407bf1c49fb40b8f461c2c7526af736d87e
+refs/heads/master: 74af283102b358b0da545460d0d176f473e110f6
diff --git a/trunk/arch/s390/kernel/topology.c b/trunk/arch/s390/kernel/topology.c
index 632b13e10053..a947899dcba1 100644
--- a/trunk/arch/s390/kernel/topology.c
+++ b/trunk/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)