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path: root/drivers/thermal/gov_fair_share.c
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2024-10-23thermal: core: Introduce thermal_cdev_update_nocheck()Rafael J. Wysocki
Three thermal governors call __thermal_cdev_update() under the cdev lock without doing any checks, so in order to reduce the related code duplication, introduce a new helper function called thermal_cdev_update_nocheck() for them and make them use it. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/1835097.VLH7GnMWUR@rjwysocki.net Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-10-22thermal: core: Move lists of thermal instances to trip descriptorsRafael J. Wysocki
In almost all places where a thermal zone's list of thermal instances is walked, there is a check to match a specific trip point and it is walked in vain whenever there are no cooling devices associated with the given trip. To address this, store the lists of thermal instances in trip point descriptors instead of storing them in thermal zones and adjust all code using those lists accordingly. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/5522726.Sb9uPGUboI@rjwysocki.net Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-24thermal: gov_fair_share: Eliminate unnecessary integer divisionsRafael J. Wysocki
The computations carried out by fair_share_throttle() for each trip point include at least one redundant integer division which introduces superfluous rounding errors. Also the multiplications by 100 in it are not really necessary and can be eliminated. Rearrange fair_share_throttle() to carry out only one integer division per trip and only as many integer multiplications as necessary and rename one variable in it (while at it). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-24thermal: gov_fair_share: Use trip thresholds instead of trip temperaturesRafael J. Wysocki
In principle, the Fair Share governor should take trip hysteresis into account. After all, once a trip has been crossed on the way up, mitigation is still needed until it is crossed on the way down. For this reason, make it use trip thresholds that are computed by the core when trips are crossed, so as to apply mitigations if the zone temperature is in a hysteresis rage of one or more trips that were crossed on the way up, but have not been crossed on the way down yet. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-24thermal: gov_fair_share: Use .manage() callback instead of .throttle()Rafael J. Wysocki
The Fair Share governor tries very hard to be stateless and so it calls get_trip_level() from fair_share_throttle() every time, even though the number produced by this function for all of the trips during a given thermal zone update is actually the same. Since get_trip_level() walks all of the trips in the thermal zone every time it is called, doing this may generate quite a bit of completely useless overhead. For this reason, make the governor use the new .manage() callback instead of .throttle() which allows it to call get_trip_level() just once and use the value computed by it to handle all of the trips. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-08thermal: core: Move threshold out of struct thermal_tripRafael J. Wysocki
The threshold field in struct thermal_trip is only used internally by the thermal core and it is better to prevent drivers from misusing it. It also takes some space unnecessarily in the trip tables passed by drivers to the core during thermal zone registration. For this reason, introduce struct thermal_trip_desc as a wrapper around struct thermal_trip, move the threshold field directly into it and make the thermal core store struct thermal_trip_desc objects in the internal thermal zone trip tables. Adjust all of the code using trip tables in the thermal core accordingly. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-01-29thermal: gov_fair_share: Fix dependency on trip points orderingRafael J. Wysocki
The computation in the fair share governor's get_trip_level() function currently works under the assumption that the temperature ordering of trips[] in a thermal zone is ascending, which need not be the case. However, get_trip_level() can be made work regardless of whether or not the trips table is ordered by temperature in any way, so change it accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-10-20thermal: core: Pass trip pointer to governor throttle callbackRafael J. Wysocki
Modify the governor .throttle() callback definition so that it takes a trip pointer instead of a trip index as its second argument, adjust the governors accordingly and update the core code invoking .throttle(). This causes the governors to become independent of the representation of the list of trips in the thermal zone structure. This change is not expected to alter the general functionality. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2023-10-20thermal: gov_fair_share: Rearrange get_trip_level()Rafael J. Wysocki
Make get_trip_level() use for_each_trip() to iterate over trip points and make it call thermal_zone_trip_id() to obtain the integer ID of a given trip point so as to avoid relying on the knowledge of struct thermal_zone_device internals. The general functionality is not expected to be changed. This change causes the governor to use trip pointers instead of trip indices everywhere except for the fair_share_throttle() second argument that will be modified subsequently along with the definition of the governor .throttle() callback. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2023-09-28thermal: core: Store trip pointer in struct thermal_instanceRafael J. Wysocki
Replace the integer trip number stored in struct thermal_instance with a pointer to the relevant trip and adjust the code using the structure in question accordingly. The main reason for making this change is to allow the trip point to cooling device binding code more straightforward, as illustrated by subsequent modifications of the ACPI thermal driver, but it also helps to clarify the overall design and allows the governor code overhead to be reduced (through subsequent modifications). The only case in which it adds complexity is trip_point_show() that needs to walk the trips[] table to find the index of the given trip point, but this is not a critical path and the interface that trip_point_show() belongs to is problematic anyway (for instance, it doesn't cover the case when the same cooling devices is associated with multiple trip points). This is a preliminary change and the affected code will be refined by a series of subsequent modifications of thermal governors, the core and the ACPI thermal driver. The general functionality is not expected to be affected by this change. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2023-04-01thermal/core: Relocate the traces definition in thermal directoryDaniel Lezcano
The traces are exported but only local to the thermal core code. On the other side, the traces take the thermal zone device structure as argument, thus they have to rely on the exported thermal.h header file. As we want to move the structure to the private thermal core header, first we have to relocate those traces to the same place as many drivers do. Cc: Steven Rostedt <rostedt@goodmis.org> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20230307133735.90772-2-daniel.lezcano@linaro.org
2023-01-06thermal/core/governors: Use thermal_zone_get_trip() instead of ops functionsDaniel Lezcano
The governors are using the ops->get_trip_* functions, Replace these calls with thermal_zone_get_trip(). Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> # IPA Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20221003092602.1323944-5-daniel.lezcano@linaro.org
2022-10-25thermal: Validate new state in cur_state_store()Viresh Kumar
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>
2022-08-17thermal/core: Move the thermal zone lock out of the governorsDaniel Lezcano
All the governors throttling ops are taking/releasing the lock at the beginning and the end of the function. We can move the mutex to the throttling call site instead. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20220805153834.2510142-4-daniel.lezcano@linaro.org
2022-08-17thermal/governors: Group the thermal zone lock inside the throttle functionDaniel Lezcano
The thermal zone lock is taken in the different places in the throttling path. At the first glance it does not hurt to move them at the beginning and the end of the 'throttle' function. That will allow a consolidation of the lock in the next following changes. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20220805153834.2510142-3-daniel.lezcano@linaro.org
2022-07-28thermal/core: Rename 'trips' to 'num_trips'Daniel Lezcano
In order to use thermal trips defined in the thermal structure, rename the 'trips' field to 'num_trips' to have the 'trips' field containing the thermal trip points. Cc: Alexandre Bailon <abailon@baylibre.com> Cc: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linexp.org> Link: https://lore.kernel.org/r/20220722200007.1839356-8-daniel.lezcano@linexp.org Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2021-04-22thermal/core/fair share: Use the lockless __thermal_cdev_update() functionLukasz Luba
Use the new helper function and avoid unnecessery second lock/unlock, which was present in old approach with thermal_cdev_update(). Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210422153624.6074-3-lukasz.luba@arm.com
2021-04-22thermal/core/fair share: Lock the thermal zone while looping over instancesLukasz Luba
The tz->lock must be hold during the looping over the instances in that thermal zone. This lock was missing in the governor code since the beginning, so it's hard to point into a particular commit. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210422153624.6074-2-lukasz.luba@arm.com
2020-05-22thermal/governors: Prefix all source files with gov_Amit Kucheria
Bang-bang governor source file is prefixed with gov_. Do the same for other governors for consistency so they're easy to find in the sources. Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/b9a85d3204712f14e320504948c12712dc0b291b.1589199124.git.amit.kucheria@linaro.org