ANDROID: sched/tune: Move SchedTune cpu API into UtilClamp wrappers

The SchedTune CPU boosting API is currently used from sugov_get_util()
to get the boosted utilization and to pass it into schedutil_cpu_util().

When UtilClamp is in use instead we call schedutil_cpu_util() by
passing in just the CFS utilization and the clamping is done internally
on the aggregated CFS+RT utilization for FREQUENCY_UTIL calls.

This asymmetry is not required moreover, schedutil code is polluted by
non-mainline SchedTune code.

Wrap SchedTune API call related to cpu utilization boosting with a more
generic and mainlinish UtilClamp call:

 - uclamp_rq_util_with(cpu, util, p)  <= boosted_cpu_util(cpu)

This new API is already used in schedutil_cpu_util() to clamp the
aggregated RT+CFS utilization on FREQUENCY_UTIL calls.

Move the cpu boosting into uclamp_rq_util_with() so that we remove any
SchedTune specific bit from kernel/sched/cpufreq_schedutil.c.

Get rid of the no more required boosted_cpu_util(cpu) method and replace
it with a stune_util(cpu, util) which signature is better aligned with
its uclamp_rq_util_with(cpu, util, p) counterpart.

Bug: 120440300
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Change-Id: I45b0f0f54123fe0a2515fa9f1683842e6b99234f
[Removed superfluous __maybe_unused for capacity_orig_of]
Signed-off-by: Quentin Perret <qperret@google.com>

Documentation/scheduler/sched-tune.txt

@@ -233,9 +233,9 @@ Thus, with the sched_cfs_boost enabled we have the following main functions to
 get the current utilization of a CPU:
 
   cpu_util()
-  boosted_cpu_util()
+  stune_util()
 
-The new boosted_cpu_util() is similar to the first but returns a boosted
+The new stune_util() is similar to the first but returns a boosted
 utilization signal which is a function of the sched_cfs_boost value.
 
 This function is used in the CFS scheduler code paths where schedutil needs to

kernel/sched/cpufreq_schedutil.c

@@ -326,13 +326,19 @@ unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
 static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)
 {
 	struct rq *rq = cpu_rq(sg_cpu->cpu);
-	unsigned long util = boosted_cpu_util(sg_cpu->cpu, cpu_util_rt(rq));
+#ifdef CONFIG_SCHED_TUNE
+	unsigned long util = stune_util(sg_cpu->cpu, cpu_util_rt(rq));
+#else
+	unsigned long util = cpu_util_freq(sg_cpu->cpu);
+#endif
+	unsigned long util_cfs = util - cpu_util_rt(rq);
 	unsigned long max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu);
 
 	sg_cpu->max = max;
 	sg_cpu->bw_dl = cpu_bw_dl(rq);
 
-	return schedutil_cpu_util(sg_cpu->cpu, util, max, FREQUENCY_UTIL, NULL);
+	return schedutil_cpu_util(sg_cpu->cpu, util_cfs, max,
+				  FREQUENCY_UTIL, NULL);
 }
 
 /**

kernel/sched/fair.c

@@ -5868,7 +5868,7 @@ schedtune_task_margin(struct task_struct *task)
 }
 
 unsigned long
-boosted_cpu_util(int cpu, unsigned long other_util)
+stune_util(int cpu, unsigned long other_util)
 {
 	unsigned long util = min_t(unsigned long, SCHED_CAPACITY_SCALE,
 				   cpu_util_cfs(cpu_rq(cpu)) + other_util);

kernel/sched/sched.h

@@ -2416,6 +2416,14 @@ static inline unsigned long cpu_util_rt(struct rq *rq)
 {
 	return READ_ONCE(rq->avg_rt.util_avg);
 }
+
+static inline unsigned long cpu_util_freq(int cpu)
+{
+	struct rq *rq = cpu_rq(cpu);
+
+	return min(cpu_util_cfs(rq) + cpu_util_rt(rq), capacity_orig_of(cpu));
+}
+
 #else /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
 static inline unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
 				 unsigned long max, enum schedutil_type type,

kernel/sched/tune.h

@@ -20,7 +20,7 @@ int schedtune_prefer_idle(struct task_struct *tsk);
 void schedtune_enqueue_task(struct task_struct *p, int cpu);
 void schedtune_dequeue_task(struct task_struct *p, int cpu);
 
-unsigned long boosted_cpu_util(int cpu, unsigned long other_util);
+unsigned long stune_util(int cpu, unsigned long other_util);
 
 #else /* CONFIG_SCHED_TUNE */
 
@@ -32,6 +32,4 @@ unsigned long boosted_cpu_util(int cpu, unsigned long other_util);
 #define schedtune_enqueue_task(task, cpu) do { } while (0)
 #define schedtune_dequeue_task(task, cpu) do { } while (0)
 
-#define boosted_cpu_util(cpu, other_util) cpu_util_cfs(cpu_rq(cpu))
-
 #endif /* CONFIG_SCHED_TUNE */