powercap: DTPM: Fix spelling mistake "initialze" -> "initialize"

There is a spelling mistake in a pr_info() message. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Ra

powercap: DTPM: Fix spelling mistake "initialze" -> "initialize"

There is a spelling mistake in a pr_info() message. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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powercap: DTPM: dtpm_node_callback[] can be static

drivers/powercap/dtpm.c:525:22: warning: symbol 'dtpm_node_callback' was not declared. Should it be static?

Fixes: 3759ec678e89 ("powercap/drivers

powercap: DTPM: dtpm_node_callback[] can be static

drivers/powercap/dtpm.c:525:22: warning: symbol 'dtpm_node_callback' was not declared. Should it be static?

Fixes: 3759ec678e89 ("powercap/drivers/dtpm: Add hierarchy creation")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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powercap/dtpm: Move the 'root' reset place

The 'root' node is checked everytime a dtpm node is destroyed.

When we reach the end of the hierarchy destruction function, we can
unconditionnaly set the

powercap/dtpm: Move the 'root' reset place

The 'root' node is checked everytime a dtpm node is destroyed.

When we reach the end of the hierarchy destruction function, we can
unconditionnaly set the 'root' node to NULL again.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20220130210210.549877-5-daniel.lezcano@linaro.org

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powercap/dtpm: Destroy hierarchy function

The hierarchy creation function exits but without a destroy hierarchy
function. Due to that, the modules creating the hierarchy can not be
unloaded properly

powercap/dtpm: Destroy hierarchy function

The hierarchy creation function exits but without a destroy hierarchy
function. Due to that, the modules creating the hierarchy can not be
unloaded properly because they don't have an exit callback.

Provide the dtpm_destroy_hierarchy() function to remove the previously
created hierarchy.

The function relies on all the release mechanisms implemented by the
underlying powercap framework.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20220130210210.549877-4-daniel.lezcano@linaro.org

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powercap/dtpm: Fixup kfree for virtual node

When the node is virtual there is no release function associated which
can free the memory.

Free the memory when no 'ops' exists.

Signed-off-by: Daniel

powercap/dtpm: Fixup kfree for virtual node

When the node is virtual there is no release function associated which
can free the memory.

Free the memory when no 'ops' exists.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20220130210210.549877-3-daniel.lezcano@linaro.org

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powercap/dtpm: Change locking scheme

The different functions are all called through the
dtpm_create_hierarchy() which handle the mutex. The different
functions are used in this context, consequently

powercap/dtpm: Change locking scheme

The different functions are all called through the
dtpm_create_hierarchy() which handle the mutex. The different
functions are used in this context, consequently with the lock always
held.

Remove all locks taken in the function and add the lock in the
hierarchy creation function.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20220130210210.549877-1-daniel.lezcano@linaro.org

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powercap/drivers/dtpm: Add hierarchy creation

The DTPM framework is available but without a way to configure it.

This change provides a way to create a hierarchy of DTPM node where
the power consum

powercap/drivers/dtpm: Add hierarchy creation

The DTPM framework is available but without a way to configure it.

This change provides a way to create a hierarchy of DTPM node where
the power consumption reflects the sum of the children's power
consumption.

It is up to the platform to specify an array of dtpm nodes where each
element has a pointer to its parent, except the top most one. The type
of the node gives the indication of which initialization callback to
call. At this time, we can create a virtual node, where its purpose is
to be a parent in the hierarchy, and a DT node where the name
describes its path.

In order to ensure a nice self-encapsulation, the DTPM subsys array
contains a couple of initialization functions, one to setup the DTPM
backend and one to initialize it up. With this approach, the DTPM
framework has a very few material to export.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20220128163537.212248-3-daniel.lezcano@linaro.org

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powercap/drivers/dtpm: Convert the init table section to a simple array

The init table section is freed after the system booted. However the
next changes will make per module the DTPM description, s

powercap/drivers/dtpm: Convert the init table section to a simple array

The init table section is freed after the system booted. However the
next changes will make per module the DTPM description, so the table
won't be accessible when the module is loaded.

In order to fix that, we should move the table to the data section
where there are very few entries and that makes strange to add it
there.

The main goal of the table was to keep self-encapsulated code and we
can keep it almost as it by using an array instead.

Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20220128163537.212248-2-daniel.lezcano@linaro.org

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powercap/drivers/dtpm: Reduce trace verbosity

The traces when registering a powerzone is at the pr_info level and
should be changed to pr_debug as requested by Greg-KH.

Cc: Greg KH <gregkh@linuxfou

powercap/drivers/dtpm: Reduce trace verbosity

The traces when registering a powerzone is at the pr_info level and
should be changed to pr_debug as requested by Greg-KH.

Cc: Greg KH <gregkh@linuxfoundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lkml.kernel.org/r/YGAnRx8SiZHFPpY6@kroah.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20211123101601.2433340-2-daniel.lezcano@linaro.org

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powercap: DTPM: Drop unused local variable from init_dtpm()

The dtpm_descr variable in init_dtpm() is not used after commit
f751db8adaea ("powercap/drivers/dtpm: Disable DTPM at boot time"),
so drop

powercap: DTPM: Drop unused local variable from init_dtpm()

The dtpm_descr variable in init_dtpm() is not used after commit
f751db8adaea ("powercap/drivers/dtpm: Disable DTPM at boot time"),
so drop it.

Fixes: f751db8adaea ("powercap/drivers/dtpm: Disable DTPM at boot time")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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powercap/drivers/dtpm: Disable DTPM at boot time

The DTPM framework misses a mechanism to set it up. That is currently
under review but will come after the next cycle.

As the distro are enabling al

powercap/drivers/dtpm: Disable DTPM at boot time

The DTPM framework misses a mechanism to set it up. That is currently
under review but will come after the next cycle.

As the distro are enabling all the kernel options, the DTPM framework
is enabled on platforms where the energy model is not implemented,
thus making the framework inconsistent and disrupting the CPU
frequency scaling service.

Remove the initialization at boot time as a hot fix.

Fixes: 7a89d7eacf8e ("powercap/drivers/dtpm: Simplify the dtpm table")
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reported-By: Doug Smythies <dsmythies@telus.net>
Tested-By: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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powercap/drivers/dtpm: Fix power limit initialization

When a DTPM node is registered its power limit must be initialized to
the power max.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

powercap/drivers/dtpm: Fix power limit initialization

When a DTPM node is registered its power limit must be initialized to
the power max.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210318205238.21937-1-daniel.lezcano@linaro.org

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powercap/drivers/dtpm: Use container_of instead of a private data field

The dtpm framework provides an API to allocate a dtpm node. However
when a backend dtpm driver needs to allocate a dtpm node i

powercap/drivers/dtpm: Use container_of instead of a private data field

The dtpm framework provides an API to allocate a dtpm node. However
when a backend dtpm driver needs to allocate a dtpm node it must
define its own structure and store the pointer of this structure in
the private field of the dtpm structure.

It is more elegant to use the container_of macro and add the dtpm
structure inside the dtpm backend specific structure. The code will be
able to deal properly with the dtpm structure as a generic entity,
making all this even more self-encapsulated.

The dtpm_alloc() function does no longer make sense as the dtpm
structure will be allocated when allocating the device specific dtpm
structure. The dtpm_init() is provided instead.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20210312130411.29833-4-daniel.lezcano@linaro.org

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powercap/drivers/dtpm: Simplify the dtpm table

The dtpm table is an array of pointers, that forces the user of the
table to define initdata along with the declaration of the table
entry. It is more

powercap/drivers/dtpm: Simplify the dtpm table

The dtpm table is an array of pointers, that forces the user of the
table to define initdata along with the declaration of the table
entry. It is more efficient to create an array of dtpm structure, so
the declaration of the table entry can be done by initializing the
different fields.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20210312130411.29833-3-daniel.lezcano@linaro.org

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powercap/drivers/dtpm: Encapsulate even more the code

In order to increase the self-encapsulation of the dtpm generic code,
the following changes are adding a power update ops to the dtpm
ops. That

powercap/drivers/dtpm: Encapsulate even more the code

In order to increase the self-encapsulation of the dtpm generic code,
the following changes are adding a power update ops to the dtpm
ops. That allows the generic code to call directly the dtpm backend
function to update the power values.

The power update function does compute the power characteristics when
the function is invoked. In the case of the CPUs, the power
consumption depends on the number of online CPUs. The online CPUs mask
is not up to date at CPUHP_AP_ONLINE_DYN state in the tear down
callback. That is the reason why the online / offline are at separate
state. As there is already an existing state for DTPM, this one is
only moved to the DEAD state, so there is no addition of new state
with these changes. The dtpm node is not removed when the cpu is
unplugged.

That simplifies the code for the next changes and results in a more
self-encapsulated code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20210312130411.29833-1-daniel.lezcano@linaro.org

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powercap/drivers/dtpm: Fix root node initialization

The root node is not set to NULL when the dtpm root node is
removed. Consequently, it is not possible to create a new root
as it is already set.

powercap/drivers/dtpm: Fix root node initialization

The root node is not set to NULL when the dtpm root node is
removed. Consequently, it is not possible to create a new root
as it is already set.

Set the root node to NULL when the last node is removed.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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powercap/drivers/dtpm: Fix an IS_ERR() vs NULL check

The powercap_register_control_type() function never returns NULL, it
returns error pointers on error so update this check.

Fixes: a20d0ef97abf (

powercap/drivers/dtpm: Fix an IS_ERR() vs NULL check

The powercap_register_control_type() function never returns NULL, it
returns error pointers on error so update this check.

Fixes: a20d0ef97abf ("powercap/drivers/dtpm: Add API for dynamic thermal power management")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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powercap/drivers/dtpm: Fix some missing unlock bugs

We need to unlock on these paths before returning.

Fixes: a20d0ef97abf ("powercap/drivers/dtpm: Add API for dynamic thermal power management")
Si

powercap/drivers/dtpm: Fix some missing unlock bugs

We need to unlock on these paths before returning.

Fixes: a20d0ef97abf ("powercap/drivers/dtpm: Add API for dynamic thermal power management")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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powercap/drivers/dtpm: Fix a double shift bug

The DTPM_POWER_LIMIT_FLAG is used for test_bit() etc which take a bit
number so it should be bit 0. But currently it's set to BIT(0) then
that is doubl

powercap/drivers/dtpm: Fix a double shift bug

The DTPM_POWER_LIMIT_FLAG is used for test_bit() etc which take a bit
number so it should be bit 0. But currently it's set to BIT(0) then
that is double shifted equivalent to BIT(BIT(0)). This doesn't cause a
run time problem because it's done consistently.

Fixes: a20d0ef97abf ("powercap/drivers/dtpm: Add API for dynamic thermal power management")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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powercap/drivers/dtpm: Fix __udivdi3 and __aeabi_uldivmod unresolved symbols

32-bit architectures do not support u64 divisions, so the macro
DIV_ROUND_CLOSEST is not adequate as the compiler will re

powercap/drivers/dtpm: Fix __udivdi3 and __aeabi_uldivmod unresolved symbols

32-bit architectures do not support u64 divisions, so the macro
DIV_ROUND_CLOSEST is not adequate as the compiler will replace the
call to an unexisting function for the platform, leading to
unresolved references to symbols.

Fix this by using the compatible macros:

DIV64_U64_ROUND_CLOSEST and DIV_ROUND_CLOSEST_ULL.

Fixes: a20d0ef97abf ("powercap/drivers/dtpm: Add API for dynamic thermal power management")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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powercap/drivers/dtpm: Add API for dynamic thermal power management

On the embedded world, the complexity of the SoC leads to an
increasing number of hotspots which need to be monitored and mitigate

powercap/drivers/dtpm: Add API for dynamic thermal power management

On the embedded world, the complexity of the SoC leads to an
increasing number of hotspots which need to be monitored and mitigated
as a whole in order to prevent the temperature to go above the
normative and legally stated 'skin temperature'.

Another aspect is to sustain the performance for a given power budget,
for example virtual reality where the user can feel dizziness if the
GPU performance is capped while a big CPU is processing something
else. Or reduce the battery charging because the dissipated power is
too high compared with the power consumed by other devices.

The userspace is the most adequate place to dynamically act on the
different devices by limiting their power given an application
profile: it has the knowledge of the platform.

These userspace daemons are in charge of the Dynamic Thermal Power
Management (DTPM).

Nowadays, the dtpm daemons are abusing the thermal framework as they
act on the cooling device state to force a specific and arbitrary
state without taking care of the governor decisions. Given the closed
loop of some governors that can confuse the logic or directly enter in
a decision conflict.

As the number of cooling device support is limited today to the CPU
and the GPU, the dtpm daemons have little control on the power
dissipation of the system. The out of tree solutions are hacking
around here and there in the drivers, in the frameworks to have
control on the devices. The common solution is to declare them as
cooling devices.

There is no unification of the power limitation unit, opaque states
are used.

This patch provides a way to create a hierarchy of constraints using
the powercap framework. The devices which are registered as power
limit-able devices are represented in this hierarchy as a tree. They
are linked together with intermediate nodes which are just there to
propagate the constraint to the children.

The leaves of the tree are the real devices, the intermediate nodes
are virtual, aggregating the children constraints and power
characteristics.

Each node have a weight on a 2^10 basis, in order to reflect the
percentage of power distribution of the children's node. This
percentage is used to dispatch the power limit to the children.

The weight is computed against the max power of the siblings.

This simple approach allows to do a fair distribution of the power
limit.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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