thermal: core: Fix thermal zone suspend-resume synchronization

[ Upstream commit 4e814173a8c4f432fd068b1c796f0416328c9d99 ]

There are 3 synchronization issues with thermal zone suspend-resume
durin

thermal: core: Fix thermal zone suspend-resume synchronization

[ Upstream commit 4e814173a8c4f432fd068b1c796f0416328c9d99 ]

There are 3 synchronization issues with thermal zone suspend-resume
during system-wide transitions:

1. The resume code runs in a PM notifier which is invoked after user
space has been thawed, so it can run concurrently with user space
which can trigger a thermal zone device removal. If that happens,
the thermal zone resume code may use a stale pointer to the next
list element and crash, because it does not hold thermal_list_lock
while walking thermal_tz_list.

2. The thermal zone resume code calls thermal_zone_device_init()
outside the zone lock, so user space or an update triggered by
the platform firmware may see an inconsistent state of a
thermal zone leading to unexpected behavior.

3. Clearing the in_suspend global variable in thermal_pm_notify()
allows __thermal_zone_device_update() to continue for all thermal
zones and it may as well run before the thermal_tz_list walk (or
at any point during the list walk for that matter) and attempt to
operate on a thermal zone that has not been resumed yet. It may
also race destructively with thermal_zone_device_init().

To address these issues, add thermal_list_lock locking to
thermal_pm_notify(), especially arount the thermal_tz_list,
make it call thermal_zone_device_init() back-to-back with
__thermal_zone_device_update() under the zone lock and replace
in_suspend with per-zone bool "suspend" indicators set and unset
under the given zone's lock.

Link: https://lore.kernel.org/linux-pm/20231218162348.69101-1-bo.ye@mediatek.com/
Reported-by: Bo Ye <bo.ye@mediatek.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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thermal: Constify the trip argument of the .get_trend() zone callback

Add 'const' to the definition of the 'trip' argument of the
.get_trend() thermal zone callback to indicate that the trip point
p

thermal: Constify the trip argument of the .get_trend() zone callback

Add 'const' to the definition of the 'trip' argument of the
.get_trend() thermal zone callback to indicate that the trip point
passed to it should not be modified by it and adjust the
callback functions implementing it, thermal_get_trend() in the
ACPI thermal driver and __ti_thermal_get_trend(), accordingly.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Michal Wilczynski <michal.wilczynski@intel.com>

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thermal: core: Drop thermal_zone_device_register()

There are no more users of thermal_zone_device_register(), so drop it
from the core.

Note that thermal_zone_device_register_with_trips() may be re

thermal: core: Drop thermal_zone_device_register()

There are no more users of thermal_zone_device_register(), so drop it
from the core.

Note that thermal_zone_device_register_with_trips() may be renamed to
thermal_zone_device_register() in the future, but only after a grace
period allowing all of the possible work in progress that may be using
the latter to adjust.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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thermal: core: Add function for registering tripless thermal zones

Multiple callers of thermal_zone_device_register() don't pass any trips
to it and they might use a shortened argument list for that

thermal: core: Add function for registering tripless thermal zones

Multiple callers of thermal_zone_device_register() don't pass any trips
to it and they might use a shortened argument list for that, so add
a special function with fewer arguments for this purpose.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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thermal: core: Clean up headers of thermal zone registration functions

For consistency, add a missing thermal_zone_device_register_with_trips()
stub for the CONFIG_THERMAL unset case, specify argume

thermal: core: Clean up headers of thermal zone registration functions

For consistency, add a missing thermal_zone_device_register_with_trips()
stub for the CONFIG_THERMAL unset case, specify argument names in all of
the thermal zone registration and unregistration function headers and
make all of them use white space consistently.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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thermal: core: Rework .get_trend() thermal zone callback

Passing a struct thermal_trip pointer instead of a trip index to the
.get_trend() thermal zone callback allows one of its 2 implementations,

thermal: core: Rework .get_trend() thermal zone callback

Passing a struct thermal_trip pointer instead of a trip index to the
.get_trend() thermal zone callback allows one of its 2 implementations,
the thermal_get_trend() function in the ACPI thermal driver, to be
simplified quite a bit, and the other implementation of it in the
ti-soc-thermal driver does not even use the relevant callback argument.

For this reason, change the .get_trend() thermal zone callback
definition and adjust the related code accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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thermal: core: Drop unused .get_trip_*() callbacks

After recent changes in the ACPI thermal driver and in the Intel DTS
IOSF thermal driver, all thermal zone drivers are expected to use trip
tables

thermal: core: Drop unused .get_trip_*() callbacks

After recent changes in the ACPI thermal driver and in the Intel DTS
IOSF thermal driver, all thermal zone drivers are expected to use trip
tables for initialization and none of them should implement
.get_trip_type(), .get_trip_temp() or .get_trip_hyst() callbacks, so
drop these callbacks entirely from the core.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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thermal: core: Rework and rename __for_each_thermal_trip()

Rework the currently unused __for_each_thermal_trip() to pass original
pointers to struct thermal_trip objects to the callback, so it can b

thermal: core: Rework and rename __for_each_thermal_trip()

Rework the currently unused __for_each_thermal_trip() to pass original
pointers to struct thermal_trip objects to the callback, so it can be
used for updating trip data (e.g. temperatures), rename it to
for_each_thermal_trip() and make it available to modular drivers.

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

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thermal: core: Add priv pointer to struct thermal_trip

Add a new field called priv to struct thermal_trip to allow thermal
drivers to store pointers to their local data associated with trip
points.

thermal: core: Add priv pointer to struct thermal_trip

Add a new field called priv to struct thermal_trip to allow thermal
drivers to store pointers to their local data associated with trip
points.

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

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thermal: core: Introduce thermal_zone_device_exec()

Introduce a new helper function, thermal_zone_device_exec(), that can
be used by drivers to run a given callback routine under the zone lock.

Sig

thermal: core: Introduce thermal_zone_device_exec()

Introduce a new helper function, thermal_zone_device_exec(), that can
be used by drivers to run a given callback routine under the zone lock.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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thermal: core: constify params in thermal_zone_device_register

Since commit 3d439b1a2ad3 ("thermal/core: Alloc-copy-free the thermal zone
parameters structure"), thermal_zone_device_register() alloc

thermal: core: constify params in thermal_zone_device_register

Since commit 3d439b1a2ad3 ("thermal/core: Alloc-copy-free the thermal zone
parameters structure"), thermal_zone_device_register() allocates a copy
of the tzp argument and callers need not explicitly manage its lifetime.

This means the function no longer cares about the parameter being
mutable, so constify it.

No functional change.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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thermal: core: Encapsulate tz->device field

There are still some drivers needing to play with the thermal zone
device internals. That is not the best but until we can figure out if
the information i

thermal: core: Encapsulate tz->device field

There are still some drivers needing to play with the thermal zone
device internals. That is not the best but until we can figure out if
the information is really needed, let's encapsulate the field used in
the thermal zone device structure, so we can move forward relocating
the thermal zone device structure definition in the thermal framework
private headers.

Some drivers are accessing tz->device, that implies they need to have
the knowledge of the thermal_zone_device structure but we want to
self-encapsulate this structure and reduce the scope of the structure
to the thermal core only.

By adding this wrapper, these drivers won't need the thermal zone
device structure definition and are no longer an obstacle to its
relocation to the private thermal core headers.

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

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thermal/of: Unexport unused OF functions

The functions thermal_of_zone_register() and
thermal_of_zone_unregister() are no longer needed from the drivers as
the devm_ variant is always used.

Make th

thermal/of: Unexport unused OF functions

The functions thermal_of_zone_register() and
thermal_of_zone_unregister() are no longer needed from the drivers as
the devm_ variant is always used.

Make them static in the C file and remove their declaration from thermal.h

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230404075138.2914680-2-daniel.lezcano@linaro.org

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thermal/core: Remove thermal_bind_params structure

Remove struct thermal_bind_params because no one is using it for thermal
binding now.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by

thermal/core: Remove thermal_bind_params structure

Remove struct thermal_bind_params because no one is using it for thermal
binding now.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230330104526.3196-1-rui.zhang@intel.com

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thermal: core: Introduce thermal_cooling_device_update()

Introduce a core thermal API function, thermal_cooling_device_update(),
for updating the max_state value for a cooling device and rearranging

thermal: core: Introduce thermal_cooling_device_update()

Introduce a core thermal API function, thermal_cooling_device_update(),
for updating the max_state value for a cooling device and rearranging
its statistics in sysfs after a possible change of its ->get_max_state()
callback return value.

That callback is now invoked only once, during cooling device
registration, to populate the max_state field in the cooling device
object, so if its return value changes, it needs to be invoked again
and the new return value needs to be stored as max_state. Moreover,
the statistics presented in sysfs need to be rearranged in general,
because there may not be enough room in them to store data for all
of the possible states (in the case when max_state grows).

The new function takes care of that (and some other minor things
related to it), but some extra locking and lockdep annotations are
added in several places too to protect against crashes in the cases
when the statistics are not present or when a stale max_state value
might be used by sysfs attributes.

Note that the actual user of the new function will be added separately.

Link: https://lore.kernel.org/linux-pm/53ec1f06f61c984100868926f282647e57ecfb2d.camel@intel.com/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>

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thermal: Add a thermal zone id accessor

In order to get the thermal zone id but without directly accessing the
thermal zone device structure, add an accessor.

Use the accessor in the hwmon_scmi and

thermal: Add a thermal zone id accessor

In order to get the thermal zone id but without directly accessing the
thermal zone device structure, add an accessor.

Use the accessor in the hwmon_scmi and acpi_thermal.

No functional change intented.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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thermal/core: Add thermal_zone_device structure 'type' accessor

The thermal zone device structure is exposed via the exported
thermal.h header. This structure should stay private the thermal core
co

thermal/core: Add thermal_zone_device structure 'type' accessor

The thermal zone device structure is exposed via the exported
thermal.h header. This structure should stay private the thermal core
code. In order to encapsulate the structure, let's add an accessor to
get the 'type' of the thermal zone.

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

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thermal/core: Add a thermal zone 'devdata' accessor

The thermal zone device structure is exposed to the different drivers
and obviously they access the internals while that should be
restricted to t

thermal/core: Add a thermal zone 'devdata' accessor

The thermal zone device structure is exposed to the different drivers
and obviously they access the internals while that should be
restricted to the core thermal code.

In order to self-encapsulate the thermal core code, we need to prevent
the drivers accessing directly the thermal zone structure and provide
accessor functions to deal with.

Provide an accessor to the 'devdata' structure and make use of it in
the different drivers.

No functional changes intended.

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

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thermal: ACPI: Make helpers retrieve temperature only

It is slightly better to make the ACPI thermal helper functions retrieve
the trip point temperature only instead of doing the full trip point
in

thermal: ACPI: Make helpers retrieve temperature only

It is slightly better to make the ACPI thermal helper functions retrieve
the trip point temperature only instead of doing the full trip point
initialization, because they are also used for updating some already
registered trip points, in which case initializing a new trip just
in order to update the temperature of an existing one is somewhat
wasteful.

Modify the ACPI thermal helpers accordingly and update their users.

No intentional functional impact.

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

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thermal: ACPI: Add ACPI trip point routines

Add library routines to populate a generic thermal trip point
structure with data obtained by evaluating a specific object in the
ACPI Namespace.

Signed-

thermal: ACPI: Add ACPI trip point routines

Add library routines to populate a generic thermal trip point
structure with data obtained by evaluating a specific object in the
ACPI Namespace.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Co-developed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

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thermal/drivers/qcom: Fix set_trip_temp() deadlock

The set_trip_temp() callback is used when changing the trip temperature
through sysfs. As it is called with the thermal-zone-device lock held
it mu

thermal/drivers/qcom: Fix set_trip_temp() deadlock

The set_trip_temp() callback is used when changing the trip temperature
through sysfs. As it is called with the thermal-zone-device lock held
it must not use thermal_zone_get_trip() directly or it will deadlock.

Fixes: 78c3e2429be8 ("thermal/drivers/qcom: Use generic thermal_zone_get_trip() function")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20221214131617.2447-2-johan+linaro@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>

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thermal/core: Add a generic thermal_zone_set_trip() function

The thermal zone ops defines a set_trip callback where we can invoke
the backend driver to set an interrupt for the next trip point
tempe

thermal/core: Add a generic thermal_zone_set_trip() function

The thermal zone ops defines a set_trip callback where we can invoke
the backend driver to set an interrupt for the next trip point
temperature being crossed the way up or down, or setting the low level
with the hysteresis.

The ops is only called from the thermal sysfs code where the userspace
has the ability to modify a trip point characteristic.

With the effort of encapsulating the thermal framework core code,
let's create a thermal_zone_set_trip() which is the writable side of
the thermal_zone_get_trip() and put there all the ops encapsulation.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20221003092602.1323944-4-daniel.lezcano@linaro.org

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thermal/core: Add a generic thermal_zone_get_trip() function

The thermal_zone_device_ops structure defines a set of ops family,
get_trip_temp(), get_trip_hyst(), get_trip_type(). Each of them is
ret

thermal/core: Add a generic thermal_zone_get_trip() function

The thermal_zone_device_ops structure defines a set of ops family,
get_trip_temp(), get_trip_hyst(), get_trip_type(). Each of them is
returning a property of a trip point.

The result is the code is calling the ops everywhere to get a trip
point which is supposed to be defined in the backend driver. It is a
non-sense as a thermal trip can be generic and used by the backend
driver to declare its trip points.

Part of the thermal framework has been changed and all the OF thermal
drivers are using the same definition for the trip point and use a
thermal zone registration variant to pass those trip points which are
part of the thermal zone device structure.

Consequently, we can use a generic function to get the trip points
when they are stored in the thermal zone device structure.

This approach can be generalized to all the drivers and we can get rid
of the ops->get_trip_*. That will result to a much more simpler code
and make possible to rework how the thermal trip are handled in the
thermal core framework as discussed previously.

This change adds a function thermal_zone_get_trip() where we get the
thermal trip point structure which contains all the properties (type,
temp, hyst) instead of doing multiple calls to ops->get_trip_*.

That opens the door for trip point extension with more attributes. For
instance, replacing the trip points disabled bitmask with a 'disabled'
field in the structure.

Here we replace all the calls to ops->get_trip_* in the thermal core
code with a call to the thermal_zone_get_trip() function.

The thermal zone ops defines a callback to retrieve the critical
temperature. As the trip handling is being reworked, all the trip
points will be the same whatever the driver and consequently finding
the critical trip temperature will be just a loop to search for a
critical trip point type.

Provide such a generic function, so we encapsulate the ops
get_crit_temp() which can be removed when all the backend drivers are
using the generic trip points handling.

While at it, add the thermal_zone_get_num_trips() to encapsulate the
code more and reduce the grip with the thermal framework internals.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20221003092602.1323944-2-daniel.lezcano@linaro.org

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thermal: Validate new state in cur_state_store()

In cur_state_store(), the new state of the cooling device is received
from user-space and is not validated by the thermal core but the same is
left f

thermal: Validate new state in cur_state_store()

In cur_state_store(), the new state of the cooling device is received
from user-space and is not validated by the thermal core but the same is
left for the individual drivers to take care of. Apart from duplicating
the code it leaves possibility for introducing bugs where a driver may
not do it right.

Lets make the thermal core check the new state itself and store the max
value in the cooling device structure.

Link: https://lore.kernel.org/all/Y0ltRJRjO7AkawvE@kili/
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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thermal/of: Remove the thermal_zone_of_get_sensor_id() function

The function thermal_zone_of_get_sensor_id() is no longer used
anywhere, remove it.

Signed-off-by: Daniel Lezcano <daniel.lezcano@lin

thermal/of: Remove the thermal_zone_of_get_sensor_id() function

The function thermal_zone_of_get_sensor_id() is no longer used
anywhere, remove it.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20220818082316.2717095-2-daniel.lezcano@linaro.org

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