The power allocator governor uses ftrace to output a bunch of internal
data for debugging and tuning.  Currently, the requested power it
outputs is the "weighted" requested power, that is, what each cooling
device has requested multiplied by the cooling device weight.  It is
more useful to trace the real request, without any weight being
applied.

This commit only affects the data traced, there is no functional change.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: NJavi Merino <javi.merino@arm.com>
Signed-off-by: NEduardo Valentin <edubezval@gmail.com>

In situations where there is an uneven number of cooling devices, the
division of power among them can lead to a milliwatt being dropped on
the floor due to rounding errors.  This doesn't sound like a lot, but
some devices only grant the lowest cooling device state for their
maximum power.  So for instance, if the granted_power is the maximum
power and all devices are getting their maximum power, one would get
max_power - 1, making it choose cooling device state 1, instead of 0.

Round the division to make the calculation more accurate.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: NJavi Merino <javi.merino@arm.com>
Signed-off-by: NEduardo Valentin <edubezval@gmail.com>

Add trace events for the power allocator governor and the power actor
interface of the cpu cooling device.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NJavi Merino <javi.merino@arm.com>
Signed-off-by: NEduardo Valentin <edubezval@gmail.com>

The power allocator governor is a thermal governor that controls system
and device power allocation to control temperature.  Conceptually, the
implementation divides the sustainable power of a thermal zone among
all the heat sources in that zone.

This governor relies on "power actors", entities that represent heat
sources.  They can report current and maximum power consumption and
can set a given maximum power consumption, usually via a cooling
device.

The governor uses a Proportional Integral Derivative (PID) controller
driven by the temperature of the thermal zone.  The output of the
controller is a power budget that is then allocated to each power
actor that can have bearing on the temperature we are trying to
control.  It decides how much power to give each cooling device based
on the performance they are requesting.  The PID controller ensures
that the total power budget does not exceed the control temperature.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Signed-off-by: NJavi Merino <javi.merino@arm.com>
Signed-off-by: NEduardo Valentin <edubezval@gmail.com>