[RFC 2/7] cpuidle: Add cpu poke support

Abel Vesa
2019-03-27T13:21:50Z

Having a poke operation per state, allows each cpuidle driver to
implement, for each state, different ways of waking up (poking) cores.

Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
---
drivers/cpuidle/cpuidle.c | 34 ++++++++++++++++++++++++++++++++++
include/linux/cpuidle.h | 6 ++++++
2 files changed, 40 insertions(+)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 7f10830..fca5313 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -297,6 +297,29 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
}

/**
+ * cpuidle_poke_single - poke the specified cpu to wake up from
+ * current idle state
+ *
+ * @dev: cpuidle device for this cpu
+ * @drv: cpuidle driver for this cpu
+ * @cpu: the index of the cpu
+ */
+int cpuidle_poke_single(struct cpuidle_driver *drv, struct cpuidle_device *dev,
+ int cpu)
+{
+ struct cpuidle_state *state;
+
+ if (cpuidle_disabled())
+ return 0;
+
+ state = sched_idle_get_state(cpu);
+ if (state && state->poke)
+ return state->poke(dev, drv, cpu);
+
+ return 0;
+}
+
+/**
* cpuidle_select - ask the cpuidle framework to choose an idle state
*
* @drv: the cpuidle driver
@@ -414,6 +437,17 @@ void cpuidle_resume(void)
mutex_unlock(&cpuidle_lock);
}

+void cpuidle_poke(const struct cpumask *mask)
+{
+ struct cpuidle_device *dev = cpuidle_get_device();
+ struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+ int cpu;
+
+ for_each_cpu(cpu, mask) {
+ WARN_ON(cpuidle_poke_single(drv, dev, cpu));
+ }
+}
+
/**
* cpuidle_enable_device - enables idle PM for a CPU
* @dev: the CPU
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 88a9119..0270771 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -55,6 +55,10 @@ struct cpuidle_state {
struct cpuidle_driver *drv,
int index);

+ int (*poke) (struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int cpu);
+
int (*enter_dead) (struct cpuidle_device *dev, int index);

/*
@@ -145,6 +149,7 @@ extern void cpuidle_unregister(struct cpuidle_driver *drv);
extern void cpuidle_pause_and_lock(void);
extern void cpuidle_resume_and_unlock(void);
extern void cpuidle_pause(void);
+extern void cpuidle_poke(const struct cpumask *mask);
extern void cpuidle_resume(void);
extern int cpuidle_enable_device(struct cpuidle_device *dev);
extern void cpuidle_disable_device(struct cpuidle_device *dev);
@@ -181,6 +186,7 @@ static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
static inline void cpuidle_pause_and_lock(void) { }
static inline void cpuidle_resume_and_unlock(void) { }
static inline void cpuidle_pause(void) { }
+static inline void cpuidle_poke(const struct cpumask *mask) { }
static inline void cpuidle_resume(void) { }
static inline int cpuidle_enable_device(struct cpuidle_device *dev)
{return -ENODEV; }
--
2.7.4