cpufreq / sched: Pass flags to cpufreq_update_util()

It is useful to know the reason why cpufreq_update_util() has just
been called and that can be passed as flags to cpufreq_update_util()
and to the ->func() callback in struct update_util_data.  However,
doing that in addition to passing the util and max arguments they
already take would be clumsy, so avoid it.

Instead, use the observation that the schedutil governor is part
of the scheduler proper, so it can access scheduler data directly.
This allows the util and max arguments of cpufreq_update_util()
and the ->func() callback in struct update_util_data to be replaced
with a flags one, but schedutil has to be modified to follow.

Thus make the schedutil governor obtain the CFS utilization
information from the scheduler and use the "RT" and "DL" flags
instead of the special utilization value of ULONG_MAX to track
updates from the RT and DL sched classes.  Make it non-modular
too to avoid having to export scheduler variables to modules at
large.

Next, update all of the other users of cpufreq_update_util()
and the ->func() callback in struct update_util_data accordingly.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

3 files changed, 3 insertions, 6 deletions

diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 74919aa81dcb..4dc95250cf4e 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -194,7 +194,7 @@ config CPU_FREQ_GOV_CONSERVATIVE
           If in doubt, say N.
 
 config CPU_FREQ_GOV_SCHEDUTIL
-        tristate "'schedutil' cpufreq policy governor"
+        bool "'schedutil' cpufreq policy governor"
         depends on CPU_FREQ && SMP
         select CPU_FREQ_GOV_ATTR_SET
         select IRQ_WORK
@@ -208,9 +208,6 @@ config CPU_FREQ_GOV_SCHEDUTIL
           frequency tipping point is at utilization/capacity equal to 80% in
           both cases.
 
-          To compile this driver as a module, choose M here: the module will
-          be called cpufreq_schedutil.
-
           If in doubt, say N.
 
 comment "CPU frequency scaling drivers"
diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index e415349ab31b..642dd0f183a8 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -260,7 +260,7 @@ static void dbs_irq_work(struct irq_work *irq_work)
 }
 
 static void dbs_update_util_handler(struct update_util_data *data, u64 time,
-                                    unsigned long util, unsigned long max)
+                                    unsigned int flags)
 {
         struct cpu_dbs_info *cdbs = container_of(data, struct cpu_dbs_info, update_util);
         struct policy_dbs_info *policy_dbs = cdbs->policy_dbs;
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index be9eade147f2..bdbe9369146b 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1329,7 +1329,7 @@ static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
 }
 
 static void intel_pstate_update_util(struct update_util_data *data, u64 time,
-                                     unsigned long util, unsigned long max)
+                                     unsigned int flags)
 {
         struct cpudata *cpu = container_of(data, struct cpudata, update_util);
         u64 delta_ns = time - cpu->sample.time;