vh: sched: Avoid cluster in CPD for RT placement

If a cluster is in CPD, it will have longer wake-up latency. This is
bad for latency sensitive tasks like RT, so avoid this kind of cpu.

Bug: 309620400
Change-Id: I5f96f8f1fd63cc96e67f88bb4045d6beee7238e1
Signed-off-by: Rick Yiu <rickyiu@google.com>

5 files changed, 51 insertions, 6 deletions

diff --git a/drivers/soc/google/cal-if/cal-if.c b/drivers/soc/google/cal-if/cal-if.c
index 832113cc0..f616cc95d 100644
--- a/drivers/soc/google/cal-if/cal-if.c
+++ b/drivers/soc/google/cal-if/cal-if.c
@@ -34,6 +34,9 @@
 
 extern s32 gs_chipid_get_dvfs_version(void);
 
+// The first parameter is cluster id, the second parameter is enable/disable.
+void (*set_cluster_enabled_cb)(int, int) = NULL;
+
 static int (*exynos_cal_pd_bcm_sync)(unsigned int id, bool on);
 static DEFINE_MUTEX(cal_pd_bcm_sync_mutex);
 
@@ -356,6 +359,14 @@ int cal_cpu_status(unsigned int cpu)
 }
 EXPORT_SYMBOL_GPL(cal_cpu_status);
 
+void register_set_cluster_enabled_cb(void (*func)(int, int))
+{
+	// This function could only be registered once.
+	BUG_ON(set_cluster_enabled_cb);
+	set_cluster_enabled_cb = func;
+}
+EXPORT_SYMBOL_GPL(register_set_cluster_enabled_cb);
+
 int cal_cluster_enable(unsigned int cluster)
 {
 	int ret;
@@ -365,6 +376,9 @@ int cal_cluster_enable(unsigned int cluster)
 	ret = pmucal_cpu_cluster_enable(cluster);
 	spin_unlock(&pmucal_cpu_lock);
 
+	if (likely(ret == 0 && set_cluster_enabled_cb))
+		set_cluster_enabled_cb(cluster, 1);
+
 	scnprintf(clock_name, 32, "CAL_CLUSTER_ENABLE_%u", cluster);
 	trace_clock_set_rate(clock_name, 1, raw_smp_processor_id());
 
@@ -381,6 +395,8 @@ int cal_cluster_disable(unsigned int cluster)
 	ret = pmucal_cpu_cluster_disable(cluster);
 	spin_unlock(&pmucal_cpu_lock);
 
+	if (likely(ret == 0 && set_cluster_enabled_cb))
+		set_cluster_enabled_cb(cluster, 0);
 
 	scnprintf(clock_name, 32, "CAL_CLUSTER_ENABLE_%u", cluster);
 	trace_clock_set_rate(clock_name, 0, raw_smp_processor_id());
diff --git a/drivers/soc/google/vh/kernel/sched/core.c b/drivers/soc/google/vh/kernel/sched/core.c
index 4fc93affc..f0ac00a29 100644
--- a/drivers/soc/google/vh/kernel/sched/core.c
+++ b/drivers/soc/google/vh/kernel/sched/core.c
@@ -272,3 +272,13 @@ void rvh_rtmutex_prepare_setprio_pixel_mod(void *data, struct task_struct *p,
 	vp->uclamp_pi[UCLAMP_MIN] = uclamp_none(UCLAMP_MIN);
 	vp->uclamp_pi[UCLAMP_MAX] = uclamp_none(UCLAMP_MAX);
 }
+
+void set_cluster_enabled_cb(int cluster, int enabled)
+{
+	pixel_cluster_enabled[cluster] = enabled;
+}
+
+int get_cluster_enabled(int cluster)
+{
+	return pixel_cluster_enabled[cluster];
+}
diff --git a/drivers/soc/google/vh/kernel/sched/init.c b/drivers/soc/google/vh/kernel/sched/init.c
index eb1d2109c..6ac72e9b9 100644
--- a/drivers/soc/google/vh/kernel/sched/init.c
+++ b/drivers/soc/google/vh/kernel/sched/init.c
@@ -103,13 +103,15 @@ extern void rvh_setscheduler_pixel_mod(void *data, struct task_struct *p);
 extern void rvh_find_lowest_rq_pixel_mod(void *data, struct task_struct *p,
 					 struct cpumask *lowest_mask,
 					 int ret, int *cpu);
-extern void rvh_update_misfit_status_pixel_mod(void *data, struct task_struct *p,
-			struct rq *rq, bool *need_update);
+extern void rvh_update_misfit_status_pixel_mod(void *data, struct task_struct *p, struct rq *rq,
+					       bool *need_update);
 
-extern struct cpufreq_governor sched_pixel_gov;
 
 extern int pmu_poll_init(void);
+extern void set_cluster_enabled_cb(int cluster, int enabled);
+extern void register_set_cluster_enabled_cb(void (*func)(int, int));
 
+extern struct cpufreq_governor sched_pixel_gov;
 extern bool wait_for_init;
 
 int pixel_cpu_num;
@@ -118,6 +120,7 @@ int *pixel_cluster_start_cpu;
 int *pixel_cluster_start_cpu;
 int *pixel_cluster_cpu_num;
 int *pixel_cpu_to_cluster;
+int *pixel_cluster_enabled;
 bool pixel_cpu_init = false;
 
 EXPORT_SYMBOL_GPL(pixel_cpu_num);
@@ -235,6 +238,11 @@ static int init_pixel_cpu(void)
 	if (!pixel_cluster_cpu_num)
 		goto out_no_pixel_cluster_cpu_num;
 
+	pixel_cluster_enabled = kmalloc_array(pixel_cluster_num, sizeof(int), GFP_KERNEL);
+	if (!pixel_cluster_cpu_num)
+		goto out_no_pixel_cluster_enabled;
+	memset(pixel_cluster_enabled, 1, pixel_cluster_num * sizeof(int));
+
 	cur_capacity = 0;
 	for_each_possible_cpu(i) {
 		if (arch_scale_cpu_capacity(i) > cur_capacity) {
@@ -247,11 +255,15 @@ static int init_pixel_cpu(void)
 	}
 
 	pixel_cpu_init = true;
+
+	register_set_cluster_enabled_cb(set_cluster_enabled_cb);
+
 	return 0;
 
+out_no_pixel_cluster_enabled:
+	kfree(pixel_cluster_cpu_num);
 out_no_pixel_cluster_cpu_num:
 	kfree(pixel_cluster_start_cpu);
-
 out_no_pixel_cluster_start_cpu:
 	kfree(pixel_cpu_to_cluster);
 
diff --git a/drivers/soc/google/vh/kernel/sched/rt.c b/drivers/soc/google/vh/kernel/sched/rt.c
index cba70b981..33eb24c92 100644
--- a/drivers/soc/google/vh/kernel/sched/rt.c
+++ b/drivers/soc/google/vh/kernel/sched/rt.c
@@ -18,9 +18,10 @@ extern int cpu_is_idle(int cpu);
 extern int sched_cpu_idle(int cpu);
 extern bool get_prefer_high_cap(struct task_struct *p);
 
-extern int ___update_load_sum(u64 now, struct sched_avg *sa,
-			  unsigned long load, unsigned long runnable, int running);
+extern int ___update_load_sum(u64 now, struct sched_avg *sa, unsigned long load,
+			      unsigned long runnable, int running);
 extern void ___update_load_avg(struct sched_avg *sa, unsigned long load);
+extern int get_cluster_enabled(int cluster);
 
 /*****************************************************************************/
 /*                       Upstream Code Section                               */
@@ -188,6 +189,11 @@ static int find_least_loaded_cpu(struct task_struct *p, struct cpumask *lowest_m
 		if (is_idle)
 			util[cpu] = 0;
 
+		// Avoid single core cluster in CPD state
+		if (is_idle && 1 == pixel_cluster_cpu_num[pixel_cpu_to_cluster[cpu]] &&
+			!get_cluster_enabled(pixel_cpu_to_cluster[cpu]))
+			cpu_importance[cpu] = UINT_MAX;
+
 		if (task_fits[cpu]) {
 			fit_and_non_overutilized_found |= !overutilize[cpu];
 			fit_and_overutilized_found |= overutilize[cpu];
diff --git a/drivers/soc/google/vh/kernel/sched/sched_priv.h b/drivers/soc/google/vh/kernel/sched/sched_priv.h
index 66c4c682a..d10611cab 100644
--- a/drivers/soc/google/vh/kernel/sched/sched_priv.h
+++ b/drivers/soc/google/vh/kernel/sched/sched_priv.h
@@ -49,6 +49,7 @@ extern int pixel_cluster_num;
 extern int *pixel_cluster_start_cpu;
 extern int *pixel_cluster_cpu_num;
 extern int *pixel_cpu_to_cluster;
+extern int *pixel_cluster_enabled;
 
 #define cpu_overutilized(cap, max, cpu)	\
 		((cap) * sched_capacity_margin[cpu] > (max) << SCHED_CAPACITY_SHIFT)