From 980e51953771401fb3acd739506506a1d8e08384 Mon Sep 17 00:00:00 2001
From: "lakkyung.jung" <lakkyung.jung@samsung.com>
Date: Wed, 14 Mar 2018 13:46:14 +0900
Subject: [PATCH] [COMMON] sched: fair/ehmp: Add to estimate core/cluster power
 down.

after moving task, previous cpu/cluster can be powered down.
so it should be consider it when idle power was calculated.

Change-Id: I13d954a1640940a7be93d0429248be8802fd615c
Signed-off-by: lakkyung.jung <lakkyung.jung@samsung.com>
---
 include/linux/ehmp.h |  4 ++++
 kernel/sched/ehmp.c  | 36 ++++++++++++++++++++++++++++++++++++
 kernel/sched/fair.c  | 12 ++++++++++++
 3 files changed, 52 insertions(+)

diff --git a/include/linux/ehmp.h b/include/linux/ehmp.h
index ac1c09185c8e..6fdf99396efa 100644
--- a/include/linux/ehmp.h
+++ b/include/linux/ehmp.h
@@ -31,6 +31,8 @@ struct gb_qos_request {
 };
 
 #ifdef CONFIG_SCHED_EHMP
+extern int exynos_estimate_idle_state(int cpu_idx, struct cpumask *mask,
+				int state, int cpus);
 extern struct sched_group *exynos_fit_idlest_group(struct sched_domain *sd,
 		struct task_struct *p);
 extern void exynos_init_entity_util_avg(struct sched_entity *se);
@@ -59,6 +61,8 @@ extern void gb_qos_update_request(struct gb_qos_request *req, u32 new_value);
 
 extern void request_kernel_prefer_perf(int grp_idx, int enable);
 #else
+static inline int exynos_estimate_idle_state(int cpu_idx, struct cpumask *mask,
+				int state, int cpus) { return 0; }
 static inline struct sched_group *exynos_fit_idlest_group(struct sched_domain *sd,
 		struct task_struct *p) { return NULL; }
 static inline void exynos_init_entity_util_avg(struct sched_entity *se) { }
diff --git a/kernel/sched/ehmp.c b/kernel/sched/ehmp.c
index ce396851e9b9..18ab92fbb754 100644
--- a/kernel/sched/ehmp.c
+++ b/kernel/sched/ehmp.c
@@ -73,6 +73,42 @@ static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
 
 #define tsk_cpus_allowed(tsk)	(&(tsk)->cpus_allowed)
 
+/**********************************************************************
+ * Energy diff		                                              *
+ **********************************************************************/
+#define EAS_CPU_PRV	0
+#define EAS_CPU_NXT	1
+#define EAS_CPU_BKP	2
+
+int exynos_estimate_idle_state(int cpu_idx, struct cpumask *mask,
+				int state, int cpus)
+{
+	unsigned int deepest_state_residency = 0;
+	unsigned int next_timer_us = 0;
+	int grp_nr_running = 0;
+	int deepest_state = 0;
+	int i;
+	int estimate_state = 0;
+
+	if (cpu_idx == EAS_CPU_PRV)
+		grp_nr_running++;
+
+	for_each_cpu(i, mask) {
+		grp_nr_running += cpu_rq(i)->nr_running;
+
+		next_timer_us = ktime_to_us(tick_nohz_get_sleep_length_cpu(i));
+		deepest_state_residency = cpuidle_get_target_residency(i, state);
+
+		if (next_timer_us > deepest_state_residency)
+			deepest_state++;
+	}
+
+	if (!grp_nr_running && deepest_state == cpus)
+		estimate_state = state + 1;
+
+	return estimate_state;
+}
+
 /**********************************************************************
  * task initialization                                                *
  **********************************************************************/
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 17e9e680e1a6..5605b2ec9e8e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6118,6 +6118,18 @@ static int group_idle_state(struct energy_env *eenv, int cpu_idx)
 	 */
 	max_idle_state_idx = sg->sge->nr_idle_states - 2;
 	new_state = grp_util * max_idle_state_idx;
+
+	/*
+	 * after moving, previous cpu/cluster can be powered down,
+	 * so it should be consider it when idle power was calculated.
+	 */
+	if (sched_feat(EXYNOS_HMP)) {
+		new_state = exynos_estimate_idle_state(cpu_idx, sched_group_span(sg),
+						max_idle_state_idx, sg->group_weight);
+		if (new_state)
+			return new_state;
+	}
+
 	if (grp_util <= 0) {
 		/* group will have no util, use lowest state */
 		new_state = max_idle_state_idx + 1;
-- 
2.20.1