1 files changed, 65 insertions, 19 deletions

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 42f50c3..e8d1aeb 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -22,6 +22,7 @@
 #include <linux/pfn.h>
 #include <linux/cpuset.h>
 #include <linux/node.h>
+#include <linux/stop_machine.h>
 #include <asm/sparsemem.h>
 #include <asm/prom.h>
 #include <asm/smp.h>
@@ -1254,6 +1255,13 @@ u64 memory_hotplug_max(void)
 
 /* Virtual Processor Home Node (VPHN) support */
 #ifdef CONFIG_PPC_SPLPAR
+struct topology_update_data {
+	struct topology_update_data *next;
+	unsigned int cpu;
+	int old_nid;
+	int new_nid;
+};
+
 static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];
 static cpumask_t cpu_associativity_changes_mask;
 static int vphn_enabled;
@@ -1405,41 +1413,79 @@ static long vphn_get_associativity(unsigned long cpu,
 }
 
 /*
+ * Update the CPU maps and sysfs entries for a single CPU when its NUMA
+ * characteristics change. This function doesn't perform any locking and is
+ * only safe to call from stop_machine().
+ */
+static int update_cpu_topology(void *data)
+{
+	struct topology_update_data *update;
+	unsigned long cpu;
+
+	if (!data)
+		return -EINVAL;
+
+	cpu = get_cpu();
+
+	for (update = data; update; update = update->next) {
+		if (cpu != update->cpu)
+			continue;
+
+		unregister_cpu_under_node(update->cpu, update->old_nid);
+		unmap_cpu_from_node(update->cpu);
+		map_cpu_to_node(update->cpu, update->new_nid);
+		register_cpu_under_node(update->cpu, update->new_nid);
+	}
+
+	return 0;
+}
+
+/*
  * Update the node maps and sysfs entries for each cpu whose home node
  * has changed. Returns 1 when the topology has changed, and 0 otherwise.
  */
 int arch_update_cpu_topology(void)
 {
-	int cpu, nid, old_nid, changed = 0;
+	unsigned int cpu, changed = 0;
+	struct topology_update_data *updates, *ud;
 	unsigned int associativity[VPHN_ASSOC_BUFSIZE] = {0};
 	struct device *dev;
+	int weight, i = 0;
+
+	weight = cpumask_weight(&cpu_associativity_changes_mask);
+	if (!weight)
+		return 0;
+
+	updates = kzalloc(weight * (sizeof(*updates)), GFP_KERNEL);
+	if (!updates)
+		return 0;
 
 	for_each_cpu(cpu, &cpu_associativity_changes_mask) {
+		ud = &updates[i++];
+		ud->cpu = cpu;
 		vphn_get_associativity(cpu, associativity);
-		nid = associativity_to_nid(associativity);
+		ud->new_nid = associativity_to_nid(associativity);
 
-		if (nid < 0 || !node_online(nid))
-			nid = first_online_node;
+		if (ud->new_nid < 0 || !node_online(ud->new_nid))
+			ud->new_nid = first_online_node;
 
-		old_nid = numa_cpu_lookup_table[cpu];
+		ud->old_nid = numa_cpu_lookup_table[cpu];
 
-		/* Disable hotplug while we update the cpu
-		 * masks and sysfs.
-		 */
-		get_online_cpus();
-		unregister_cpu_under_node(cpu, old_nid);
-		unmap_cpu_from_node(cpu);
-		map_cpu_to_node(cpu, nid);
-		register_cpu_under_node(cpu, nid);
-		put_online_cpus();
-
-		dev = get_cpu_device(cpu);
+		if (i < weight)
+			ud->next = &updates[i];
+	}
+
+	stop_machine(update_cpu_topology, &updates[0], cpu_online_mask);
+
+	for (ud = &updates[0]; ud; ud = ud->next) {
+		dev = get_cpu_device(ud->cpu);
 		if (dev)
 			kobject_uevent(&dev->kobj, KOBJ_CHANGE);
-		cpumask_clear_cpu(cpu, &cpu_associativity_changes_mask);
+		cpumask_clear_cpu(ud->cpu, &cpu_associativity_changes_mask);
 		changed = 1;
 	}
 
+	kfree(updates);
 	return changed;
 }
 
@@ -1488,10 +1534,10 @@ static int dt_update_callback(struct notifier_block *nb,
 	int rc = NOTIFY_DONE;
 
 	switch (action) {
-	case OF_RECONFIG_ADD_PROPERTY:
 	case OF_RECONFIG_UPDATE_PROPERTY:
 		update = (struct of_prop_reconfig *)data;
-		if (!of_prop_cmp(update->dn->type, "cpu")) {
+		if (!of_prop_cmp(update->dn->type, "cpu") &&
+		    !of_prop_cmp(update->prop->name, "ibm,associativity")) {
 			u32 core_id;
 			of_property_read_u32(update->dn, "reg", &core_id);
 			stage_topology_update(core_id);