cpuidle: Allow enforcing deepest idle state selection
When idle injection is used to cap power, we need to override the
governor's choice of idle states.
For this reason, make it possible the deepest idle state selection to
be enforced by setting a flag on a given CPU to achieve the maximum
potential power draw reduction.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 15deea4..da346f2 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -74,6 +74,7 @@
struct cpuidle_device {
unsigned int registered:1;
unsigned int enabled:1;
+ unsigned int use_deepest_state:1;
unsigned int cpu;
int last_residency;
@@ -192,11 +193,12 @@
static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
#endif
-#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SUSPEND)
+#ifdef CONFIG_CPU_IDLE
extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
struct cpuidle_device *dev);
extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
struct cpuidle_device *dev);
+extern void cpuidle_use_deepest_state(bool enable);
#else
static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
struct cpuidle_device *dev)
@@ -204,6 +206,9 @@
static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv,
struct cpuidle_device *dev)
{return -ENODEV; }
+static inline void cpuidle_use_deepest_state(bool enable)
+{
+}
#endif
/* kernel/sched/idle.c */