1 files changed, 51 insertions, 16 deletions

diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 6e11701..06dbe7c 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -10,6 +10,7 @@
 
 #include <linux/mutex.h>
 #include <linux/module.h>
+#include <linux/sched.h>
 #include <linux/cpuidle.h>
 #include <linux/cpumask.h>
 #include <linux/clockchips.h>
@@ -56,7 +57,7 @@ static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
 }
 
 /**
- * __cpuidle_set_driver - set per CPU driver variables the the given driver.
+ * __cpuidle_set_driver - set per CPU driver variables for the given driver.
  * @drv: a valid pointer to a struct cpuidle_driver
  *
  * For each CPU in the driver's cpumask, unset the registered driver per CPU
@@ -132,7 +133,7 @@ static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
  * cpuidle_setup_broadcast_timer - enable/disable the broadcast timer
  * @arg: a void pointer used to match the SMP cross call API
  *
- * @arg is used as a value of type 'long' with on of the two values:
+ * @arg is used as a value of type 'long' with one of the two values:
  * - CLOCK_EVT_NOTIFY_BROADCAST_ON
  * - CLOCK_EVT_NOTIFY_BROADCAST_OFF
  *
@@ -149,10 +150,8 @@ static void cpuidle_setup_broadcast_timer(void *arg)
 /**
  * __cpuidle_driver_init - initialize the driver's internal data
  * @drv: a valid pointer to a struct cpuidle_driver
- *
- * Returns 0 on success, a negative error code otherwise.
  */
-static int __cpuidle_driver_init(struct cpuidle_driver *drv)
+static void __cpuidle_driver_init(struct cpuidle_driver *drv)
 {
 	int i;
 
@@ -169,20 +168,55 @@ static int __cpuidle_driver_init(struct cpuidle_driver *drv)
 	/*
 	 * Look for the timer stop flag in the different states, so that we know
 	 * if the broadcast timer has to be set up.  The loop is in the reverse
-	 * order, because usually on of the the deeper states has this flag set.
+	 * order, because usually one of the deeper states have this flag set.
 	 */
 	for (i = drv->state_count - 1; i >= 0 ; i--) {
+		if (drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP) {
+			drv->bctimer = 1;
+			break;
+		}
+	}
+}
 
-		if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP))
-			continue;
+#ifdef CONFIG_ARCH_HAS_CPU_RELAX
+static int poll_idle(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int index)
+{
+	ktime_t	t1, t2;
+	s64 diff;
 
-		drv->bctimer = 1;
-		break;
-	}
+	t1 = ktime_get();
+	local_irq_enable();
+	while (!need_resched())
+		cpu_relax();
 
-	return 0;
+	t2 = ktime_get();
+	diff = ktime_to_us(ktime_sub(t2, t1));
+	if (diff > INT_MAX)
+		diff = INT_MAX;
+
+	dev->last_residency = (int) diff;
+
+	return index;
 }
 
+static void poll_idle_init(struct cpuidle_driver *drv)
+{
+	struct cpuidle_state *state = &drv->states[0];
+
+	snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
+	snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
+	state->exit_latency = 0;
+	state->target_residency = 0;
+	state->power_usage = -1;
+	state->flags = 0;
+	state->enter = poll_idle;
+	state->disabled = false;
+}
+#else
+static void poll_idle_init(struct cpuidle_driver *drv) {}
+#endif /* !CONFIG_ARCH_HAS_CPU_RELAX */
+
 /**
  * __cpuidle_register_driver: register the driver
  * @drv: a valid pointer to a struct cpuidle_driver
@@ -206,9 +240,7 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv)
 	if (cpuidle_disabled())
 		return -ENODEV;
 
-	ret = __cpuidle_driver_init(drv);
-	if (ret)
-		return ret;
+	__cpuidle_driver_init(drv);
 
 	ret = __cpuidle_set_driver(drv);
 	if (ret)
@@ -218,6 +250,8 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv)
 		on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,
 				 (void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1);
 
+	poll_idle_init(drv);
+
 	return 0;
 }
 
@@ -346,10 +380,11 @@ struct cpuidle_driver *cpuidle_driver_ref(void)
  */
 void cpuidle_driver_unref(void)
 {
-	struct cpuidle_driver *drv = cpuidle_get_driver();
+	struct cpuidle_driver *drv;
 
 	spin_lock(&cpuidle_driver_lock);
 
+	drv = cpuidle_get_driver();
 	if (drv && !WARN_ON(drv->refcnt <= 0))
 		drv->refcnt--;