[patch 2/2] cpu topology: various fixes/cleanups

[Heiko Carstens <heiko.carstens@de.ibm.com>]

From: Heiko Carstens <heiko.carstens@de.ibm.com>

- take return valie sysfs_create_group into account.
- don't call code that might fail on CPU_ONLINE notification. Instead call
  it on CPU_UP_PREPARE and check it's return value.
- since CPU_UP_PREPARE might fail add a CPU_UP_CANCELED handling as well.
- use hotcpu_notifier instead of register_hotcpu_notifier
- #ifdef code that isn't needed in the !CONFIG_HOTPLUG_CPU case.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---

Could be split up into a bunch of several patches if really needed.

 drivers/base/topology.c |   33 +++++++++++++++++----------------
 1 files changed, 17 insertions(+), 16 deletions(-)

Index: linux-2.6/drivers/base/topology.c
===================================================================
--- linux-2.6.orig/drivers/base/topology.c	2006-10-09 09:15:27.000000000 +0200
+++ linux-2.6/drivers/base/topology.c	2006-10-09 09:25:05.000000000 +0200
@@ -97,10 +97,10 @@
 /* Add/Remove cpu_topology interface for CPU device */
 static int __cpuinit topology_add_dev(struct sys_device * sys_dev)
 {
-	sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
-	return 0;
+	return sysfs_create_group(&sys_dev->kobj, &topology_attr_group);
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
 static int __cpuinit topology_remove_dev(struct sys_device * sys_dev)
 {
 	sysfs_remove_group(&sys_dev->kobj, &topology_attr_group);
@@ -112,34 +112,35 @@
 {
 	unsigned int cpu = (unsigned long)hcpu;
 	struct sys_device *sys_dev;
+	int rc = 0;
 
 	sys_dev = get_cpu_sysdev(cpu);
 	switch (action) {
-	case CPU_ONLINE:
-		topology_add_dev(sys_dev);
+	case CPU_UP_PREPARE:
+		rc = topology_add_dev(sys_dev);
 		break;
+	case CPU_UP_CANCELED:
 	case CPU_DEAD:
 		topology_remove_dev(sys_dev);
 		break;
 	}
-	return NOTIFY_OK;
+	return rc ? NOTIFY_BAD : NOTIFY_OK;
 }
-
-static struct notifier_block __cpuinitdata topology_cpu_notifier =
-{
-	.notifier_call = topology_cpu_callback,
-};
+#endif
 
 static int __cpuinit topology_sysfs_init(void)
 {
-	int i;
+	struct sys_device *sys_dev;
+	int cpu;
+	int rc;
 
-	for_each_online_cpu(i) {
-		topology_cpu_callback(&topology_cpu_notifier, CPU_ONLINE,
-				(void *)(long)i);
+	for_each_online_cpu(cpu) {
+		sys_dev = get_cpu_sysdev(cpu);
+		rc = topology_add_dev(sys_dev);
+		if (rc)
+			return rc;
 	}
-
-	register_hotcpu_notifier(&topology_cpu_notifier);
+	hotcpu_notifier(topology_cpu_callback, 0);
 
 	return 0;
 }