idle, x86: Allow off-lined CPU to enter deeper C states

Currently when a CPU is off-lined it enters either MWAIT-based idle or,
if MWAIT is not desired or supported, HLT-based idle (which places the
processor in C1 state). This patch allows processors without MWAIT
support to stay in states deeper than C1.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index f3ebbba368b3..d557bcd0ada7 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -51,6 +51,8 @@ struct cpuidle_state {
         int (*enter)    (struct cpuidle_device *dev,
                         struct cpuidle_driver *drv,
                         int index);
+
+        int (*enter_dead) (struct cpuidle_device *dev, int index);
 };
 
 /* Idle State Flags */
@@ -147,6 +149,8 @@ extern int cpuidle_wrap_enter(struct cpuidle_device *dev,
                                 struct cpuidle_driver *drv, int index,
                                 int (*enter)(struct cpuidle_device *dev,
                                         struct cpuidle_driver *drv, int index));
+extern int cpuidle_play_dead(void);
+
 #else
 static inline void disable_cpuidle(void) { }
 static inline int cpuidle_idle_call(void) { return -ENODEV; }
@@ -168,6 +172,7 @@ static inline int cpuidle_wrap_enter(struct cpuidle_device *dev,
                                 int (*enter)(struct cpuidle_device *dev,
                                         struct cpuidle_driver *drv, int index))
 { return -ENODEV; }
+static inline int cpuidle_play_dead(void) {return -ENODEV; }
 
 #endif