idle/cpuidle: Split cpuidle_idle_call main function into smaller functions

In order to allow better integration between the cpuidle framework and the
scheduler, reducing the distance between these two sub-components will
facilitate this integration by moving part of the cpuidle code in the idle
task file and, because idle.c is in the sched directory, we have access to
the scheduler's private structures.

This patch splits the cpuidle_idle_call main entry function into 3 calls
to a newly added API:

 1. select the idle state
 2. enter the idle state
 3. reflect the idle state

The cpuidle_idle_call calls these three functions to implement the main
idle entry function.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: rjw@rjwysocki.net
Cc: preeti@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1393832934-11625-1-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 50fcbb0ac4e7..accc2dd72049 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -119,6 +119,15 @@ struct cpuidle_driver {
 
 #ifdef CONFIG_CPU_IDLE
 extern void disable_cpuidle(void);
+
+extern int cpuidle_enabled(struct cpuidle_driver *drv,
+                          struct cpuidle_device *dev);
+extern int cpuidle_select(struct cpuidle_driver *drv,
+                          struct cpuidle_device *dev);
+extern int cpuidle_enter(struct cpuidle_driver *drv,
+                         struct cpuidle_device *dev, int index);
+extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
+
 extern int cpuidle_idle_call(void);
 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 extern struct cpuidle_driver *cpuidle_get_driver(void);
@@ -141,6 +150,16 @@ extern int cpuidle_play_dead(void);
 extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
 #else
 static inline void disable_cpuidle(void) { }
+static inline int cpuidle_enabled(struct cpuidle_driver *drv,
+                                  struct cpuidle_device *dev)
+{return -ENODEV; }
+static inline int cpuidle_select(struct cpuidle_driver *drv,
+                                 struct cpuidle_device *dev)
+{return -ENODEV; }
+static inline int cpuidle_enter(struct cpuidle_driver *drv,
+                                struct cpuidle_device *dev, int index)
+{return -ENODEV; }
+static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
 static inline int cpuidle_idle_call(void) { return -ENODEV; }
 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 {return -ENODEV; }