[PATCH] cpu state clean after hot remove

Clean CPU states in order to reuse smp boot code for CPU hotplug.

Signed-off-by: Li Shaohua<shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 6ef3069b5710..bdd7e9f55c81 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -16,6 +16,10 @@ struct sysdev_class cpu_sysdev_class = {
 EXPORT_SYMBOL(cpu_sysdev_class);
 
 #ifdef CONFIG_HOTPLUG_CPU
+#ifndef __HAVE_ARCH_SMP_PREPARE_CPU
+#define smp_prepare_cpu(cpu) (0)
+#endif
+
 static ssize_t show_online(struct sys_device *dev, char *buf)
 {
         struct cpu *cpu = container_of(dev, struct cpu, sysdev);
@@ -36,7 +40,9 @@ static ssize_t store_online(struct sys_device *dev, const char *buf,
                         kobject_hotplug(&dev->kobj, KOBJ_OFFLINE);
                 break;
         case '1':
-                ret = cpu_up(cpu->sysdev.id);
+                ret = smp_prepare_cpu(cpu->sysdev.id);
+                if (ret == 0)
+                        ret = cpu_up(cpu->sysdev.id);
                 break;
         default:
                 ret = -EINVAL;