2 files changed, 6 insertions, 7 deletions

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 6fe41742997..e38dfed41d8 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -18,7 +18,7 @@ struct sysdev_class cpu_sysdev_class = {
 };
 EXPORT_SYMBOL(cpu_sysdev_class);
 
-static struct sys_device *cpu_sys_devices[NR_CPUS];
+static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);
 
 #ifdef CONFIG_HOTPLUG_CPU
 static ssize_t show_online(struct sys_device *dev, char *buf)
@@ -68,7 +68,7 @@ void unregister_cpu(struct cpu *cpu)
         sysdev_remove_file(&cpu->sysdev, &attr_online);
 
         sysdev_unregister(&cpu->sysdev);
-        cpu_sys_devices[logical_cpu] = NULL;
+        per_cpu(cpu_sys_devices, logical_cpu) = NULL;
         return;
 }
 #else /* ... !CONFIG_HOTPLUG_CPU */
@@ -167,7 +167,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
         if (!error && cpu->hotpluggable)
                 register_cpu_control(cpu);
         if (!error)
-                cpu_sys_devices[num] = &cpu->sysdev;
+                per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
         if (!error)
                 register_cpu_under_node(num, cpu_to_node(num));
 
@@ -180,8 +180,8 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
 
 struct sys_device *get_cpu_sysdev(unsigned cpu)
 {
-        if (cpu < NR_CPUS)
-                return cpu_sys_devices[cpu];
+        if (cpu < nr_cpu_ids && cpu_possible(cpu))
+                return per_cpu(cpu_sys_devices, cpu);
         else
                 return NULL;
 }
diff --git a/drivers/base/sys.c b/drivers/base/sys.c
index 4fbb56bcb1e..358bb0be3c0 100644
--- a/drivers/base/sys.c
+++ b/drivers/base/sys.c
@@ -175,8 +175,7 @@ int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
         }
 
         /* Check whether this driver has already been added to a class. */
-        if ((drv->entry.next != drv->entry.prev) ||
-            (drv->entry.next != NULL)) {
+        if (drv->entry.next && !list_empty(&drv->entry)) {
                 printk(KERN_WARNING "sysdev: class %s: driver (%p) has already"
                         " been registered to a class, something is wrong, but "
                         "will forge on!\n", cls->name, drv);