Merge branch 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

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

diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index 6dae6a3d2d598d2ebdce251bdd1dad4f423b85f5..e1a797e028a320d62c01e77a47f533e0998adaa3 100644 (file)
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -1,14 +1,62 @@
 /*
  * Common SMP CPU bringup/teardown functions
  */
+#include <linux/err.h>
+#include <linux/smp.h>
 #include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/percpu.h>
 
 #include "smpboot.h"
 
+#ifdef CONFIG_GENERIC_SMP_IDLE_THREAD
+/*
+ * For the hotplug case we keep the task structs around and reuse
+ * them.
+ */
+static DEFINE_PER_CPU(struct task_struct *, idle_threads);
+
+struct task_struct * __cpuinit idle_thread_get(unsigned int cpu)
+{
+       struct task_struct *tsk = per_cpu(idle_threads, cpu);
+
+       if (!tsk)
+               return ERR_PTR(-ENOMEM);
+       init_idle(tsk, cpu);
+       return tsk;
+}
+
+void __init idle_thread_set_boot_cpu(void)
+{
+       per_cpu(idle_threads, smp_processor_id()) = current;
+}
+
+static inline void idle_init(unsigned int cpu)
+{
+       struct task_struct *tsk = per_cpu(idle_threads, cpu);
+
+       if (!tsk) {
+               tsk = fork_idle(cpu);
+               if (IS_ERR(tsk))
+                       pr_err("SMP: fork_idle() failed for CPU %u\n", cpu);
+               else
+                       per_cpu(idle_threads, cpu) = tsk;
+       }
+}
+
 /**
- * smpboot_prepare - generic smpboot preparation
+ * idle_thread_init - Initialize the idle thread for a cpu
+ * @cpu:       The cpu for which the idle thread should be initialized
+ *
+ * Creates the thread if it does not exist.
  */
-int __cpuinit smpboot_prepare(unsigned int cpu)
+void __init idle_threads_init(void)
 {
-       return 0;
+       unsigned int cpu;
+
+       for_each_possible_cpu(cpu) {
+               if (cpu != smp_processor_id())
+                       idle_init(cpu);
+       }
 }
+#endif