[PATCH V5 0/2] powerpc/dlpar: Correct display of hot-add/hot-remove CPUs and memory

@@ -60,10 +60,27 @@
 static int n_mem_addr_cells, n_mem_size_cells;
 static int form1_affinity;
 
+#define TOPOLOGY_DEF_NUM_NODES	0
 #define MAX_DISTANCE_REF_POINTS 4
 static int distance_ref_points_depth;
 static const __be32 *distance_ref_points;
 static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
+static int topology_num_nodes = TOPOLOGY_DEF_NUM_NODES;
+
+/*
+ * Topology-related early parameters
+ */
+static int __init early_num_nodes(char *p)
+{
+	if (!p)
+		return 1;
+
+	topology_num_nodes = memparse(p, &p);
+	dbg("topology num nodes = 0x%d\n", topology_num_nodes);
+
+	return 0;
+}
+early_param("numnodes", early_num_nodes);
 
 /*
  * Allocate node_to_cpumask_map based on number of available nodes

@@ -892,6 +909,18 @@ static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
 	NODE_DATA(nid)->node_spanned_pages = spanned_pages;
 }
 
+static void __init setup_min_nodes(void)
+{
+	int i, l = topology_num_nodes;
+
+	for (i = 0; i < l; i++) {
+		if (!node_possible(i)) {
+			setup_node_data(i, 0, 0);
+			node_set(i, node_possible_map);
+		}
+	}
+}
+
 void __init initmem_init(void)
 {
 	int nid, cpu;

@@ -911,6 +940,8 @@ void __init initmem_init(void)
 	 */
 	nodes_and(node_possible_map, node_possible_map, node_online_map);
 
+	setup_min_nodes();
+
 	for_each_online_node(nid) {
 		unsigned long start_pfn, end_pfn;
 

@@ -62,6 +62,7 @@ static inline void sysfs_remove_device_from_node(struct device *dev,
 #if defined(CONFIG_NUMA) && defined(CONFIG_PPC_SPLPAR)
 extern int start_topology_update(void);
 extern int stop_topology_update(void);
+extern int timed_topology_update(int nsecs);
 extern int prrn_is_enabled(void);
 #else
 static inline int start_topology_update(void)

@@ -72,12 +73,22 @@ static inline int stop_topology_update(void)
 {
 	return 0;
 }
+static int timed_topology_update(int nsecs)
+{
+	return 0;
+}
 static inline int prrn_is_enabled(void)
 {
 	return 0;
 }
 #endif /* CONFIG_NUMA && CONFIG_PPC_SPLPAR */
 
+#if defined(CONFIG_PPC_SPLPAR)
+extern void shared_topology_update(void);
+#else
+#define	shared_topology_update()	0
+#endif /* CONFIG_PPC_SPLPAR */
+
 #include <asm-generic/topology.h>
 
 #ifdef CONFIG_SMP

@@ -29,6 +29,7 @@
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
+#include <linux/sched.h>
 #include <asm/cputhreads.h>
 #include <asm/sparsemem.h>
 #include <asm/prom.h>

@@ -935,7 +936,7 @@ void __init initmem_init(void)
 
 	/*
 	 * Reduce the possible NUMA nodes to the online NUMA nodes,
-	 * since we do not support node hotplug. This ensures that  we
+	 * since we do not support node hotplug. This ensures that we
 	 * lower the maximum NUMA node ID to what is actually present.
 	 */
 	nodes_and(node_possible_map, node_possible_map, node_online_map);

@@ -1179,11 +1180,16 @@ struct topology_update_data {
 	int new_nid;
 };
 
+#define	TOPOLOGY_DEF_TIMER_SECS		60
+
 static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];
 static cpumask_t cpu_associativity_changes_mask;
 static int vphn_enabled;
 static int prrn_enabled;
 static void reset_topology_timer(void);
+static int topology_timer_secs = TOPOLOGY_DEF_TIMER_SECS;
+static int topology_inited;
+static int topology_update_needed;
 
 /*
  * Store the current values of the associativity change counters in the

@@ -1277,6 +1283,12 @@ static long vphn_get_associativity(unsigned long cpu,
 			"hcall_vphn() experienced a hardware fault "
 			"preventing VPHN. Disabling polling...\n");
 		stop_topology_update();
+		break;
+	case H_SUCCESS:
+		printk(KERN_INFO
+			"VPHN hcall succeeded. Reset polling...\n");
+		timed_topology_update(0);
+		break;
 	}
 
 	return rc;

@@ -1352,8 +1364,11 @@ int arch_update_cpu_topology(void)
 	struct device *dev;
 	int weight, new_nid, i = 0;
 
-	if (!prrn_enabled && !vphn_enabled)
+	if (!prrn_enabled && !vphn_enabled) {
+		if (!topology_inited)
+			topology_update_needed = 1;
 		return 0;
+	}
 
 	weight = cpumask_weight(&cpu_associativity_changes_mask);
 	if (!weight)

@@ -1392,6 +1407,8 @@ int arch_update_cpu_topology(void)
 			cpumask_andnot(&cpu_associativity_changes_mask,
 					&cpu_associativity_changes_mask,
 					cpu_sibling_mask(cpu));
+			pr_info("Assoc chg gives same node %d for cpu%d\n",
+					new_nid, cpu);
 			cpu = cpu_last_thread_sibling(cpu);
 			continue;
 		}

@@ -1408,6 +1425,9 @@ int arch_update_cpu_topology(void)
 		cpu = cpu_last_thread_sibling(cpu);
 	}
 
+	if (i)
+		updates[i-1].next = NULL;
+
 	pr_debug("Topology update for the following CPUs:\n");
 	if (cpumask_weight(&updated_cpus)) {
 		for (ud = &updates[0]; ud; ud = ud->next) {

@@ -1454,6 +1474,7 @@ int arch_update_cpu_topology(void)
 
 out:
 	kfree(updates);
+	topology_update_needed = 0;
 	return changed;
 }
 

@@ -1468,6 +1489,14 @@ static void topology_schedule_update(void)
 	schedule_work(&topology_work);
 }
 
+void shared_topology_update(void)
+{
+	if (firmware_has_feature(FW_FEATURE_VPHN) &&
+		   lppaca_shared_proc(get_lppaca()))
+		topology_schedule_update();
+}
+EXPORT_SYMBOL(shared_topology_update);
+
 static void topology_timer_fn(unsigned long ignored)
 {
 	if (prrn_enabled && cpumask_weight(&cpu_associativity_changes_mask))

@@ -1484,7 +1513,7 @@ static void topology_timer_fn(unsigned long ignored)
 static void reset_topology_timer(void)
 {
 	topology_timer.data = 0;
-	topology_timer.expires = jiffies + 60 * HZ;
+	topology_timer.expires = jiffies + topology_timer_secs * HZ;
 	mod_timer(&topology_timer, topology_timer.expires);
 }
 

@@ -1534,15 +1563,14 @@ int start_topology_update(void)
 	if (firmware_has_feature(FW_FEATURE_PRRN)) {
 		if (!prrn_enabled) {
 			prrn_enabled = 1;
-			vphn_enabled = 0;
 #ifdef CONFIG_SMP
 			rc = of_reconfig_notifier_register(&dt_update_nb);
 #endif
 		}
-	} else if (firmware_has_feature(FW_FEATURE_VPHN) &&
+	}
+	if (firmware_has_feature(FW_FEATURE_VPHN) &&
 		   lppaca_shared_proc(get_lppaca())) {
 		if (!vphn_enabled) {
-			prrn_enabled = 0;
 			vphn_enabled = 1;
 			setup_cpu_associativity_change_counters();
 			init_timer_deferrable(&topology_timer);

@@ -1565,7 +1593,8 @@ int stop_topology_update(void)
 #ifdef CONFIG_SMP
 		rc = of_reconfig_notifier_unregister(&dt_update_nb);
 #endif
-	} else if (vphn_enabled) {
+	}
+	if (vphn_enabled) {
 		vphn_enabled = 0;
 		rc = del_timer_sync(&topology_timer);
 	}

@@ -1573,6 +1602,22 @@ int stop_topology_update(void)
 	return rc;
 }
 
+/*
+ * Change polling interval for associativity changes.
+ */
+int timed_topology_update(int nsecs)
+{
+	if (nsecs > 0)
+		topology_timer_secs = nsecs;
+	else
+		topology_timer_secs = TOPOLOGY_DEF_TIMER_SECS;
+
+	if (vphn_enabled)
+		reset_topology_timer();
+
+	return 0;
+}
+
 int prrn_is_enabled(void)
 {
 	return prrn_enabled;

@@ -1631,6 +1676,11 @@ static int topology_update_init(void)
 	if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_ops))
 		return -ENOMEM;
 
+	topology_inited = 1;
+	if (topology_update_needed)
+		bitmap_fill(cpumask_bits(&cpu_associativity_changes_mask),
+					nr_cpumask_bits);
+
 	return 0;
 }
 device_initcall(topology_update_init);

@@ -592,6 +592,8 @@ static ssize_t dlpar_show(struct class *class, struct class_attribute *attr,
 
 static int __init pseries_dlpar_init(void)
 {
+	shared_topology_update();
+
 	pseries_hp_wq = alloc_workqueue("pseries hotplug workqueue",
 					WQ_UNBOUND, 1);
 	return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr);

@@ -356,6 +356,7 @@ static int dlpar_online_cpu(struct device_node *dn)
 			BUG_ON(get_cpu_current_state(cpu)
 					!= CPU_STATE_OFFLINE);
 			cpu_maps_update_done();
+			timed_topology_update(1);
 			rc = device_online(get_cpu_device(cpu));
 			if (rc)
 				goto out;

@@ -522,6 +523,7 @@ static int dlpar_offline_cpu(struct device_node *dn)
 				set_preferred_offline_state(cpu,
 							    CPU_STATE_OFFLINE);
 				cpu_maps_update_done();
+				timed_topology_update(1);
 				rc = device_offline(get_cpu_device(cpu));
 				if (rc)
 					goto out;