Linux 3.2.80

[pandora-kernel.git] / kernel / sys.c

diff --git a/kernel/sys.c b/kernel/sys.c
index f5939c2..9d557df 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -320,7 +320,6 @@ void kernel_restart_prepare(char *cmd)
        system_state = SYSTEM_RESTART;
        usermodehelper_disable();
        device_shutdown();
-       syscore_shutdown();
 }
 
 /**
@@ -354,6 +353,29 @@ int unregister_reboot_notifier(struct notifier_block *nb)
 }
 EXPORT_SYMBOL(unregister_reboot_notifier);
 
+/* Add backwards compatibility for stable trees. */
+#ifndef PF_NO_SETAFFINITY
+#define PF_NO_SETAFFINITY              PF_THREAD_BOUND
+#endif
+
+static void migrate_to_reboot_cpu(void)
+{
+       /* The boot cpu is always logical cpu 0 */
+       int cpu = 0;
+
+       cpu_hotplug_disable();
+
+       /* Make certain the cpu I'm about to reboot on is online */
+       if (!cpu_online(cpu))
+               cpu = cpumask_first(cpu_online_mask);
+
+       /* Prevent races with other tasks migrating this task */
+       current->flags |= PF_NO_SETAFFINITY;
+
+       /* Make certain I only run on the appropriate processor */
+       set_cpus_allowed_ptr(current, cpumask_of(cpu));
+}
+
 /**
  *     kernel_restart - reboot the system
  *     @cmd: pointer to buffer containing command to execute for restart
@@ -365,7 +387,8 @@ EXPORT_SYMBOL(unregister_reboot_notifier);
 void kernel_restart(char *cmd)
 {
        kernel_restart_prepare(cmd);
-       disable_nonboot_cpus();
+       migrate_to_reboot_cpu();
+       syscore_shutdown();
        if (!cmd)
                printk(KERN_EMERG "Restarting system.\n");
        else
@@ -391,6 +414,7 @@ static void kernel_shutdown_prepare(enum system_states state)
 void kernel_halt(void)
 {
        kernel_shutdown_prepare(SYSTEM_HALT);
+       migrate_to_reboot_cpu();
        syscore_shutdown();
        printk(KERN_EMERG "System halted.\n");
        kmsg_dump(KMSG_DUMP_HALT);
@@ -409,7 +433,7 @@ void kernel_power_off(void)
        kernel_shutdown_prepare(SYSTEM_POWER_OFF);
        if (pm_power_off_prepare)
                pm_power_off_prepare();
-       disable_nonboot_cpus();
+       migrate_to_reboot_cpu();
        syscore_shutdown();
        printk(KERN_EMERG "Power down.\n");
        kmsg_dump(KMSG_DUMP_POWEROFF);