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>
drivers/powercap/dtpm.c:525:22: warning: symbol 'dtpm_node_callback' was not declared. Should it be static?
Fixes: 3759ec678e ("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>
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
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
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
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
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
The dtpm_descr variable in init_dtpm() is not used after commit
f751db8ada ("powercap/drivers/dtpm: Disable DTPM at boot time"),
so drop it.
Fixes: f751db8ada ("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>
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: 7a89d7eacf ("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>
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
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
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
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>
The powercap_register_control_type() function never returns NULL, it
returns error pointers on error so update this check.
Fixes: a20d0ef97a ("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>
We need to unlock on these paths before returning.
Fixes: a20d0ef97a ("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>
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: a20d0ef97a ("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>
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: a20d0ef97a ("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>
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>
Colin Ian King