Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszer...

[karo-tx-linux.git] / kernel / cpu.c

diff --git a/kernel/cpu.c b/kernel/cpu.c
index b03a32595cfebc34cf60e353b75028870477c4fe..ab860453841dfd244c141f329fa9cdecc1f9e063 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -271,11 +271,25 @@ void cpu_hotplug_enable(void)
 EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
 #endif /* CONFIG_HOTPLUG_CPU */
 
+static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st);
+
 static int bringup_wait_for_ap(unsigned int cpu)
 {
        struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
 
+       /* Wait for the CPU to reach CPUHP_AP_ONLINE_IDLE */
        wait_for_completion(&st->done);
+       BUG_ON(!cpu_online(cpu));
+
+       /* Unpark the stopper thread and the hotplug thread of the target cpu */
+       stop_machine_unpark(cpu);
+       kthread_unpark(st->thread);
+
+       /* Should we go further up ? */
+       if (st->target > CPUHP_AP_ONLINE_IDLE) {
+               __cpuhp_kick_ap_work(st);
+               wait_for_completion(&st->done);
+       }
        return st->result;
 }
 
@@ -296,9 +310,7 @@ static int bringup_cpu(unsigned int cpu)
        irq_unlock_sparse();
        if (ret)
                return ret;
-       ret = bringup_wait_for_ap(cpu);
-       BUG_ON(!cpu_online(cpu));
-       return ret;
+       return bringup_wait_for_ap(cpu);
 }
 
 /*
@@ -767,31 +779,20 @@ void notify_cpu_starting(unsigned int cpu)
 }
 
 /*
- * Called from the idle task. We need to set active here, so we can kick off
- * the stopper thread and unpark the smpboot threads. If the target state is
- * beyond CPUHP_AP_ONLINE_IDLE we kick cpuhp thread and let it bring up the
- * cpu further.
+ * Called from the idle task. Wake up the controlling task which brings the
+ * stopper and the hotplug thread of the upcoming CPU up and then delegates
+ * the rest of the online bringup to the hotplug thread.
  */
 void cpuhp_online_idle(enum cpuhp_state state)
 {
        struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
-       unsigned int cpu = smp_processor_id();
 
        /* Happens for the boot cpu */
        if (state != CPUHP_AP_ONLINE_IDLE)
                return;
 
        st->state = CPUHP_AP_ONLINE_IDLE;
-
-       /* Unpark the stopper thread and the hotplug thread of this cpu */
-       stop_machine_unpark(cpu);
-       kthread_unpark(st->thread);
-
-       /* Should we go further up ? */
-       if (st->target > CPUHP_AP_ONLINE_IDLE)
-               __cpuhp_kick_ap_work(st);
-       else
-               complete(&st->done);
+       complete(&st->done);
 }
 
 /* Requires cpu_add_remove_lock to be held */