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[ Upstream commit2c7b4bfade] 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> Stable-dep-of:e95fa74047("thermal: gov_power_allocator: avoid inability to reset a cdev") Signed-off-by: Sasha Levin <sashal@kernel.org>
114 lines
3.1 KiB
C
114 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* fair_share.c - A simple weight based Thermal governor
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*
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* Copyright (C) 2012 Intel Corp
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* Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*/
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#include <linux/thermal.h>
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#include "thermal_trace.h"
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#include "thermal_core.h"
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/**
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* get_trip_level: - obtains the current trip level for a zone
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* @tz: thermal zone device
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*/
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static int get_trip_level(struct thermal_zone_device *tz)
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{
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struct thermal_trip trip;
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int count;
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for (count = 0; count < tz->num_trips; count++) {
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__thermal_zone_get_trip(tz, count, &trip);
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if (tz->temperature < trip.temperature)
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break;
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}
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/*
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* count > 0 only if temperature is greater than first trip
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* point, in which case, trip_point = count - 1
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*/
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if (count > 0)
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trace_thermal_zone_trip(tz, count - 1, trip.type);
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return count;
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}
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static long get_target_state(struct thermal_zone_device *tz,
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struct thermal_cooling_device *cdev, int percentage, int level)
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{
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return (long)(percentage * level * cdev->max_state) / (100 * tz->num_trips);
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}
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/**
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* fair_share_throttle - throttles devices associated with the given zone
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* @tz: thermal_zone_device
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* @trip_index: trip point index
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*
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* Throttling Logic: This uses three parameters to calculate the new
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* throttle state of the cooling devices associated with the given zone.
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*
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* Parameters used for Throttling:
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* P1. max_state: Maximum throttle state exposed by the cooling device.
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* P2. percentage[i]/100:
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* How 'effective' the 'i'th device is, in cooling the given zone.
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* P3. cur_trip_level/max_no_of_trips:
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* This describes the extent to which the devices should be throttled.
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* We do not want to throttle too much when we trip a lower temperature,
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* whereas the throttling is at full swing if we trip critical levels.
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* (Heavily assumes the trip points are in ascending order)
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* new_state of cooling device = P3 * P2 * P1
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*/
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static int fair_share_throttle(struct thermal_zone_device *tz, int trip_index)
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{
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const struct thermal_trip *trip = &tz->trips[trip_index];
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struct thermal_instance *instance;
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int total_weight = 0;
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int total_instance = 0;
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int cur_trip_level = get_trip_level(tz);
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lockdep_assert_held(&tz->lock);
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list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
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if (instance->trip != trip)
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continue;
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total_weight += instance->weight;
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total_instance++;
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}
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list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
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int percentage;
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struct thermal_cooling_device *cdev = instance->cdev;
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if (instance->trip != trip)
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continue;
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if (!total_weight)
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percentage = 100 / total_instance;
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else
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percentage = (instance->weight * 100) / total_weight;
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instance->target = get_target_state(tz, cdev, percentage,
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cur_trip_level);
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mutex_lock(&cdev->lock);
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__thermal_cdev_update(cdev);
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mutex_unlock(&cdev->lock);
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}
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return 0;
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}
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static struct thermal_governor thermal_gov_fair_share = {
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.name = "fair_share",
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.throttle = fair_share_throttle,
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};
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THERMAL_GOVERNOR_DECLARE(thermal_gov_fair_share);
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