1 files changed, 58 insertions, 73 deletions

diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index e5a5d0c8d66b..b0a7ad566081 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -19,22 +19,12 @@
 #include <linux/sched/stat.h>
 #include <linux/math64.h>
 
-/*
- * Please note when changing the tuning values:
- * If (MAX_INTERESTING-1) * RESOLUTION > UINT_MAX, the result of
- * a scaling operation multiplication may overflow on 32 bit platforms.
- * In that case, #define RESOLUTION as ULL to get 64 bit result:
- * #define RESOLUTION 1024ULL
- *
- * The default values do not overflow.
- */
 #define BUCKETS 12
 #define INTERVAL_SHIFT 3
 #define INTERVALS (1UL << INTERVAL_SHIFT)
 #define RESOLUTION 1024
 #define DECAY 8
-#define MAX_INTERESTING 50000
-
+#define MAX_INTERESTING (50000 * NSEC_PER_USEC)
 
 /*
  * Concepts and ideas behind the menu governor
@@ -120,14 +110,14 @@ struct menu_device {
 	int             needs_update;
 	int             tick_wakeup;
 
-	unsigned int	next_timer_us;
+	u64		next_timer_ns;
 	unsigned int	bucket;
 	unsigned int	correction_factor[BUCKETS];
 	unsigned int	intervals[INTERVALS];
 	int		interval_ptr;
 };
 
-static inline int which_bucket(unsigned int duration, unsigned long nr_iowaiters)
+static inline int which_bucket(u64 duration_ns, unsigned long nr_iowaiters)
 {
 	int bucket = 0;
 
@@ -140,15 +130,15 @@ static inline int which_bucket(unsigned int duration, unsigned long nr_iowaiters
 	if (nr_iowaiters)
 		bucket = BUCKETS/2;
 
-	if (duration < 10)
+	if (duration_ns < 10ULL * NSEC_PER_USEC)
 		return bucket;
-	if (duration < 100)
+	if (duration_ns < 100ULL * NSEC_PER_USEC)
 		return bucket + 1;
-	if (duration < 1000)
+	if (duration_ns < 1000ULL * NSEC_PER_USEC)
 		return bucket + 2;
-	if (duration < 10000)
+	if (duration_ns < 10000ULL * NSEC_PER_USEC)
 		return bucket + 3;
-	if (duration < 100000)
+	if (duration_ns < 100000ULL * NSEC_PER_USEC)
 		return bucket + 4;
 	return bucket + 5;
 }
@@ -276,13 +266,13 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 		       bool *stop_tick)
 {
 	struct menu_device *data = this_cpu_ptr(&menu_devices);
-	int latency_req = cpuidle_governor_latency_req(dev->cpu);
-	int i;
-	int idx;
-	unsigned int interactivity_req;
+	s64 latency_req = cpuidle_governor_latency_req(dev->cpu);
 	unsigned int predicted_us;
+	u64 predicted_ns;
+	u64 interactivity_req;
 	unsigned long nr_iowaiters;
 	ktime_t delta_next;
+	int i, idx;
 
 	if (data->needs_update) {
 		menu_update(drv, dev);
@@ -290,15 +280,15 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	}
 
 	/* determine the expected residency time, round up */
-	data->next_timer_us = ktime_to_us(tick_nohz_get_sleep_length(&delta_next));
+	data->next_timer_ns = tick_nohz_get_sleep_length(&delta_next);
 
 	nr_iowaiters = nr_iowait_cpu(dev->cpu);
-	data->bucket = which_bucket(data->next_timer_us, nr_iowaiters);
+	data->bucket = which_bucket(data->next_timer_ns, nr_iowaiters);
 
 	if (unlikely(drv->state_count <= 1 || latency_req == 0) ||
-	    ((data->next_timer_us < drv->states[1].target_residency ||
-	      latency_req < drv->states[1].exit_latency) &&
-	     !drv->states[0].disabled && !dev->states_usage[0].disable)) {
+	    ((data->next_timer_ns < drv->states[1].target_residency_ns ||
+	      latency_req < drv->states[1].exit_latency_ns) &&
+	     !dev->states_usage[0].disable)) {
 		/*
 		 * In this case state[0] will be used no matter what, so return
 		 * it right away and keep the tick running if state[0] is a
@@ -308,18 +298,15 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 		return 0;
 	}
 
-	/*
-	 * Force the result of multiplication to be 64 bits even if both
-	 * operands are 32 bits.
-	 * Make sure to round up for half microseconds.
-	 */
-	predicted_us = DIV_ROUND_CLOSEST_ULL((uint64_t)data->next_timer_us *
-					 data->correction_factor[data->bucket],
-					 RESOLUTION * DECAY);
-	/*
-	 * Use the lowest expected idle interval to pick the idle state.
-	 */
-	predicted_us = min(predicted_us, get_typical_interval(data, predicted_us));
+	/* Round up the result for half microseconds. */
+	predicted_us = div_u64(data->next_timer_ns *
+			       data->correction_factor[data->bucket] +
+			       (RESOLUTION * DECAY * NSEC_PER_USEC) / 2,
+			       RESOLUTION * DECAY * NSEC_PER_USEC);
+	/* Use the lowest expected idle interval to pick the idle state. */
+	predicted_ns = (u64)min(predicted_us,
+				get_typical_interval(data, predicted_us)) *
+				NSEC_PER_USEC;
 
 	if (tick_nohz_tick_stopped()) {
 		/*
@@ -330,14 +317,15 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 		 * the known time till the closest timer event for the idle
 		 * state selection.
 		 */
-		if (predicted_us < TICK_USEC)
-			predicted_us = ktime_to_us(delta_next);
+		if (predicted_ns < TICK_NSEC)
+			predicted_ns = delta_next;
 	} else {
 		/*
 		 * Use the performance multiplier and the user-configurable
 		 * latency_req to determine the maximum exit latency.
 		 */
-		interactivity_req = predicted_us / performance_multiplier(nr_iowaiters);
+		interactivity_req = div64_u64(predicted_ns,
+					      performance_multiplier(nr_iowaiters));
 		if (latency_req > interactivity_req)
 			latency_req = interactivity_req;
 	}
@@ -349,27 +337,26 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	idx = -1;
 	for (i = 0; i < drv->state_count; i++) {
 		struct cpuidle_state *s = &drv->states[i];
-		struct cpuidle_state_usage *su = &dev->states_usage[i];
 
-		if (s->disabled || su->disable)
+		if (dev->states_usage[i].disable)
 			continue;
 
 		if (idx == -1)
 			idx = i; /* first enabled state */
 
-		if (s->target_residency > predicted_us) {
+		if (s->target_residency_ns > predicted_ns) {
 			/*
 			 * Use a physical idle state, not busy polling, unless
 			 * a timer is going to trigger soon enough.
 			 */
 			if ((drv->states[idx].flags & CPUIDLE_FLAG_POLLING) &&
-			    s->exit_latency <= latency_req &&
-			    s->target_residency <= data->next_timer_us) {
-				predicted_us = s->target_residency;
+			    s->exit_latency_ns <= latency_req &&
+			    s->target_residency_ns <= data->next_timer_ns) {
+				predicted_ns = s->target_residency_ns;
 				idx = i;
 				break;
 			}
-			if (predicted_us < TICK_USEC)
+			if (predicted_ns < TICK_NSEC)
 				break;
 
 			if (!tick_nohz_tick_stopped()) {
@@ -379,7 +366,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 				 * tick in that case and let the governor run
 				 * again in the next iteration of the loop.
 				 */
-				predicted_us = drv->states[idx].target_residency;
+				predicted_ns = drv->states[idx].target_residency_ns;
 				break;
 			}
 
@@ -389,13 +376,13 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 			 * closest timer event, select this one to avoid getting
 			 * stuck in the shallow one for too long.
 			 */
-			if (drv->states[idx].target_residency < TICK_USEC &&
-			    s->target_residency <= ktime_to_us(delta_next))
+			if (drv->states[idx].target_residency_ns < TICK_NSEC &&
+			    s->target_residency_ns <= delta_next)
 				idx = i;
 
 			return idx;
 		}
-		if (s->exit_latency > latency_req)
+		if (s->exit_latency_ns > latency_req)
 			break;
 
 		idx = i;
@@ -409,12 +396,10 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	 * expected idle duration is shorter than the tick period length.
 	 */
 	if (((drv->states[idx].flags & CPUIDLE_FLAG_POLLING) ||
-	     predicted_us < TICK_USEC) && !tick_nohz_tick_stopped()) {
-		unsigned int delta_next_us = ktime_to_us(delta_next);
-
+	     predicted_ns < TICK_NSEC) && !tick_nohz_tick_stopped()) {
 		*stop_tick = false;
 
-		if (idx > 0 && drv->states[idx].target_residency > delta_next_us) {
+		if (idx > 0 && drv->states[idx].target_residency_ns > delta_next) {
 			/*
 			 * The tick is not going to be stopped and the target
 			 * residency of the state to be returned is not within
@@ -422,12 +407,11 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 			 * tick, so try to correct that.
 			 */
 			for (i = idx - 1; i >= 0; i--) {
-				if (drv->states[i].disabled ||
-				    dev->states_usage[i].disable)
+				if (dev->states_usage[i].disable)
 					continue;
 
 				idx = i;
-				if (drv->states[i].target_residency <= delta_next_us)
+				if (drv->states[i].target_residency_ns <= delta_next)
 					break;
 			}
 		}
@@ -463,7 +447,7 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	struct menu_device *data = this_cpu_ptr(&menu_devices);
 	int last_idx = dev->last_state_idx;
 	struct cpuidle_state *target = &drv->states[last_idx];
-	unsigned int measured_us;
+	u64 measured_ns;
 	unsigned int new_factor;
 
 	/*
@@ -481,7 +465,7 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	 * assume the state was never reached and the exit latency is 0.
 	 */
 
-	if (data->tick_wakeup && data->next_timer_us > TICK_USEC) {
+	if (data->tick_wakeup && data->next_timer_ns > TICK_NSEC) {
 		/*
 		 * The nohz code said that there wouldn't be any events within
 		 * the tick boundary (if the tick was stopped), but the idle
@@ -491,7 +475,7 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 		 * have been idle long (but not forever) to help the idle
 		 * duration predictor do a better job next time.
 		 */
-		measured_us = 9 * MAX_INTERESTING / 10;
+		measured_ns = 9 * MAX_INTERESTING / 10;
 	} else if ((drv->states[last_idx].flags & CPUIDLE_FLAG_POLLING) &&
 		   dev->poll_time_limit) {
 		/*
@@ -501,28 +485,29 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 		 * the CPU might have been woken up from idle by the next timer.
 		 * Assume that to be the case.
 		 */
-		measured_us = data->next_timer_us;
+		measured_ns = data->next_timer_ns;
 	} else {
 		/* measured value */
-		measured_us = dev->last_residency;
+		measured_ns = dev->last_residency_ns;
 
 		/* Deduct exit latency */
-		if (measured_us > 2 * target->exit_latency)
-			measured_us -= target->exit_latency;
+		if (measured_ns > 2 * target->exit_latency_ns)
+			measured_ns -= target->exit_latency_ns;
 		else
-			measured_us /= 2;
+			measured_ns /= 2;
 	}
 
 	/* Make sure our coefficients do not exceed unity */
-	if (measured_us > data->next_timer_us)
-		measured_us = data->next_timer_us;
+	if (measured_ns > data->next_timer_ns)
+		measured_ns = data->next_timer_ns;
 
 	/* Update our correction ratio */
 	new_factor = data->correction_factor[data->bucket];
 	new_factor -= new_factor / DECAY;
 
-	if (data->next_timer_us > 0 && measured_us < MAX_INTERESTING)
-		new_factor += RESOLUTION * measured_us / data->next_timer_us;
+	if (data->next_timer_ns > 0 && measured_ns < MAX_INTERESTING)
+		new_factor += div64_u64(RESOLUTION * measured_ns,
+					data->next_timer_ns);
 	else
 		/*
 		 * we were idle so long that we count it as a perfect
@@ -542,7 +527,7 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	data->correction_factor[data->bucket] = new_factor;
 
 	/* update the repeating-pattern data */
-	data->intervals[data->interval_ptr++] = measured_us;
+	data->intervals[data->interval_ptr++] = ktime_to_us(measured_ns);
 	if (data->interval_ptr >= INTERVALS)
 		data->interval_ptr = 0;
 }