| 1 | |
| 2 | |
| 3 | * A power allocator to manage temperature
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| 4 | *
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| 5 | * Copyright (C) 2014 ARM Ltd.
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| 6 | *
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| 7 |
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| 8 |
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| 9 | #define pr_fmt(fmt) "Power allocator: " fmt
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| 10 |
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| 11 | #include <linux/slab.h>
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| 12 | #include <linux/thermal.h>
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| 13 |
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| 14 | #define CREATE_TRACE_POINTS
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| 15 | #include "thermal_trace_ipa.h"
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| 16 |
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| 17 | #include "thermal_core.h"
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| 18 |
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| 19 | #define FRAC_BITS 10
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| 20 | #define int_to_frac(x) ((x) << FRAC_BITS)
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| 21 | #define frac_to_int(x) ((x) >> FRAC_BITS)
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| 22 |
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| 23 | |
| 24 | * mul_frac() - multiply two fixed-point numbers
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| 25 | * @x: first multiplicand
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| 26 | * @y: second multiplicand
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| 27 | *
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| 28 | * Return: the result of multiplying two fixed-point numbers. The
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| 29 | * result is also a fixed-point number.
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| 30 |
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| 31 | static inline s64 mul_frac(s64 x, s64 y)
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| 32 | {
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| 33 | return (x * y) >> FRAC_BITS;
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| 34 | }
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| 35 |
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| 36 | |
| 37 | * div_frac() - divide two fixed-point numbers
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| 38 | * @x: the dividend
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| 39 | * @y: the divisor
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| 40 | *
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| 41 | * Return: the result of dividing two fixed-point numbers. The
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| 42 | * result is also a fixed-point number.
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| 43 |
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| 44 | static inline s64 div_frac(s64 x, s64 y)
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| 45 | {
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| 46 | return div_s64(x << FRAC_BITS, y);
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| 47 | }
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| 48 |
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| 49 | |
| 50 | * struct power_actor - internal power information for power actor
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| 51 | * @req_power: requested power value (not weighted)
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| 52 | * @max_power: max allocatable power for this actor
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| 53 | * @granted_power: granted power for this actor
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| 54 | * @extra_actor_power: extra power that this actor can receive
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| 55 | * @weighted_req_power: weighted requested power as input to IPA
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| 56 |
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| 57 | struct power_actor {
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| 58 | u32 req_power;
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| 59 | u32 max_power;
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| 60 | u32 granted_power;
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| 61 | u32 extra_actor_power;
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| 62 | u32 weighted_req_power;
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| 63 | };
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| 64 |
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| 65 | |
| 66 | * struct power_allocator_params - parameters for the power allocator governor
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| 67 | * @allocated_tzp: whether we have allocated tzp for this thermal zone and
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| 68 | * it needs to be freed on unbind
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| 69 | * @update_cdevs: whether or not update cdevs on the next run
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| 70 | * @err_integral: accumulated error in the PID controller.
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| 71 | * @prev_err: error in the previous iteration of the PID controller.
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| 72 | * Used to calculate the derivative term.
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| 73 | * @sustainable_power: Sustainable power (heat) that this thermal zone can
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| 74 | * dissipate
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| 75 | * @trip_switch_on: first passive trip point of the thermal zone. The
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| 76 | * governor switches on when this trip point is crossed.
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| 77 | * If the thermal zone only has one passive trip point,
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| 78 | * @trip_switch_on should be NULL.
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| 79 | * @trip_max: last passive trip point of the thermal zone. The
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| 80 | * temperature we are controlling for.
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| 81 | * @total_weight: Sum of all thermal instances weights
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| 82 | * @num_actors: number of cooling devices supporting IPA callbacks
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| 83 | * @buffer_size: internal buffer size, to avoid runtime re-calculation
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| 84 | * @power: buffer for all power actors internal power information
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| 85 |
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| 86 | struct power_allocator_params {
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| 87 | bool allocated_tzp;
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| 88 | bool update_cdevs;
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| 89 | s64 err_integral;
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| 90 | s32 prev_err;
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| 91 | u32 sustainable_power;
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| 92 | const struct thermal_trip *trip_switch_on;
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| 93 | const struct thermal_trip *trip_max;
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| 94 | int total_weight;
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| 95 | unsigned int num_actors;
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| 96 | unsigned int buffer_size;
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| 97 | struct power_actor *power;
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| 98 | };
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| 99 |
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| 100 | static bool power_actor_is_valid(struct thermal_instance *instance)
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| 101 | {
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| 102 | return cdev_is_power_actor(instance->cdev);
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| 103 | }
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| 104 |
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| 105 | |
| 106 | * estimate_sustainable_power() - Estimate the sustainable power of a thermal zone
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| 107 | * @tz: thermal zone we are operating in
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| 108 | *
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| 109 | * For thermal zones that don't provide a sustainable_power in their
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| 110 | * thermal_zone_params, estimate one. Calculate it using the minimum
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| 111 | * power of all the cooling devices as that gives a valid value that
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| 112 | * can give some degree of functionality. For optimal performance of
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| 113 | * this governor, provide a sustainable_power in the thermal zone's
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| 114 | * thermal_zone_params.
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| 115 |
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| 116 | static u32 estimate_sustainable_power(struct thermal_zone_device *tz)
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| 117 | {
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| 118 | struct power_allocator_params *params = tz->governor_data;
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| 119 | const struct thermal_trip_desc *td = trip_to_trip_desc(params->trip_max);
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| 120 | struct thermal_cooling_device *cdev;
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| 121 | struct thermal_instance *instance;
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| 122 | u32 sustainable_power = 0;
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| 123 | u32 min_power;
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| 124 |
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| 125 | list_for_each_entry(instance, &td->thermal_instances, trip_node) {
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| 126 | if (!power_actor_is_valid(instance))
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| 127 | continue;
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| 128 |
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| 129 | cdev = instance->cdev;
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| 130 | if (cdev->ops->state2power(cdev, instance->upper, &min_power))
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| 131 | continue;
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| 132 |
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| 133 | sustainable_power += min_power;
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| 134 | }
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| 135 |
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| 136 | return sustainable_power;
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| 137 | }
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| 138 |
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| 139 | |
| 140 | * estimate_pid_constants() - Estimate the constants for the PID controller
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| 141 | * @tz: thermal zone for which to estimate the constants
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| 142 | * @sustainable_power: sustainable power for the thermal zone
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| 143 | * @trip_switch_on: trip point for the switch on temperature
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| 144 | * @control_temp: target temperature for the power allocator governor
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| 145 | *
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| 146 | * This function is used to update the estimation of the PID
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| 147 | * controller constants in struct thermal_zone_parameters.
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| 148 |
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| 149 | static void estimate_pid_constants(struct thermal_zone_device *tz,
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| 150 | u32 sustainable_power,
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| 151 | const struct thermal_trip *trip_switch_on,
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| 152 | int control_temp)
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| 153 | {
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| 154 | u32 temperature_threshold = control_temp;
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| 155 | s32 k_i;
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| 156 |
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| 157 | if (trip_switch_on)
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| 158 | temperature_threshold -= trip_switch_on->temperature;
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| 159 |
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| 160 | |
| 161 | * estimate_pid_constants() tries to find appropriate default
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| 162 | * values for thermal zones that don't provide them. If a
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| 163 | * system integrator has configured a thermal zone with two
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| 164 | * passive trip points at the same temperature, that person
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| 165 | * hasn't put any effort to set up the thermal zone properly
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| 166 | * so just give up.
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| 167 |
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| 168 | if (!temperature_threshold)
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| 169 | return;
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| 170 |
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| 171 | tz->tzp->k_po = int_to_frac(sustainable_power) /
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| 172 | temperature_threshold;
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| 173 |
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| 174 | tz->tzp->k_pu = int_to_frac(2 * sustainable_power) /
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| 175 | temperature_threshold;
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| 176 |
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| 177 | k_i = tz->tzp->k_pu / 10;
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| 178 | tz->tzp->k_i = k_i > 0 ? k_i : 1;
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| 179 |
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| 180 | |
| 181 | * The default for k_d and integral_cutoff is 0, so we can
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| 182 | * leave them as they are.
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| 183 |
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| 184 | }
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| 185 |
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| 186 | |
| 187 | * get_sustainable_power() - Get the right sustainable power
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| 188 | * @tz: thermal zone for which to estimate the constants
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| 189 | * @params: parameters for the power allocator governor
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| 190 | * @control_temp: target temperature for the power allocator governor
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| 191 | *
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| 192 | * This function is used for getting the proper sustainable power value based
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| 193 | * on variables which might be updated by the user sysfs interface. If that
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| 194 | * happen the new value is going to be estimated and updated. It is also used
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| 195 | * after thermal zone binding, where the initial values where set to 0.
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| 196 |
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| 197 | static u32 get_sustainable_power(struct thermal_zone_device *tz,
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| 198 | struct power_allocator_params *params,
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| 199 | int control_temp)
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| 200 | {
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| 201 | u32 sustainable_power;
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| 202 |
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| 203 | if (!tz->tzp->sustainable_power)
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| 204 | sustainable_power = estimate_sustainable_power(tz);
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| 205 | else
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| 206 | sustainable_power = tz->tzp->sustainable_power;
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| 207 |
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| 208 |
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| 209 | if (sustainable_power != params->sustainable_power) {
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| 210 | estimate_pid_constants(tz, sustainable_power,
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| 211 | params->trip_switch_on, control_temp);
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| 212 |
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| 213 |
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| 214 | tz->tzp->sustainable_power = sustainable_power;
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| 215 | params->sustainable_power = sustainable_power;
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| 216 | }
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| 217 |
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| 218 | return sustainable_power;
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| 219 | }
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| 220 |
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| 221 | |
| 222 | * pid_controller() - PID controller
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| 223 | * @tz: thermal zone we are operating in
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| 224 | * @control_temp: the target temperature in millicelsius
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| 225 | * @max_allocatable_power: maximum allocatable power for this thermal zone
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| 226 | *
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| 227 | * This PID controller increases the available power budget so that the
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| 228 | * temperature of the thermal zone gets as close as possible to
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| 229 | * @control_temp and limits the power if it exceeds it. k_po is the
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| 230 | * proportional term when we are overshooting, k_pu is the
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| 231 | * proportional term when we are undershooting. integral_cutoff is a
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| 232 | * threshold below which we stop accumulating the error. The
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| 233 | * accumulated error is only valid if the requested power will make
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| 234 | * the system warmer. If the system is mostly idle, there's no point
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| 235 | * in accumulating positive error.
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| 236 | *
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| 237 | * Return: The power budget for the next period.
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| 238 |
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| 239 | static u32 pid_controller(struct thermal_zone_device *tz,
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| 240 | int control_temp,
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| 241 | u32 max_allocatable_power)
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| 242 | {
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| 243 | struct power_allocator_params *params = tz->governor_data;
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| 244 | s64 p, i, d, power_range;
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| 245 | s32 err, max_power_frac;
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| 246 | u32 sustainable_power;
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| 247 |
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| 248 | max_power_frac = int_to_frac(max_allocatable_power);
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| 249 |
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| 250 | sustainable_power = get_sustainable_power(tz, params, control_temp);
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| 251 |
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| 252 | err = control_temp - tz->temperature;
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| 253 | err = int_to_frac(err);
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| 254 |
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| 255 |
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| 256 | p = mul_frac(err < 0 ? tz->tzp->k_po : tz->tzp->k_pu, err);
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| 257 |
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| 258 | |
| 259 | * Calculate the integral term
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| 260 | *
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| 261 | * if the error is less than cut off allow integration (but
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| 262 | * the integral is limited to max power)
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| 263 |
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| 264 | i = mul_frac(tz->tzp->k_i, params->err_integral);
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| 265 |
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| 266 | if (err < int_to_frac(tz->tzp->integral_cutoff)) {
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| 267 | s64 i_next = i + mul_frac(tz->tzp->k_i, err);
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| 268 |
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| 269 | if (abs(i_next) < max_power_frac) {
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| 270 | i = i_next;
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| 271 | params->err_integral += err;
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| 272 | }
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| 273 | }
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| 274 |
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| 275 | |
| 276 | * Calculate the derivative term
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| 277 | *
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| 278 | * We do err - prev_err, so with a positive k_d, a decreasing
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| 279 | * error (i.e. driving closer to the line) results in less
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| 280 | * power being applied, slowing down the controller)
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| 281 |
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| 282 | d = mul_frac(tz->tzp->k_d, err - params->prev_err);
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| 283 | d = div_frac(d, jiffies_to_msecs(tz->passive_delay_jiffies));
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| 284 | params->prev_err = err;
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| 285 |
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| 286 | power_range = p + i + d;
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| 287 |
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| 288 |
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| 289 | power_range = sustainable_power + frac_to_int(power_range);
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| 290 |
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| 291 | power_range = clamp(power_range, (s64)0, (s64)max_allocatable_power);
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| 292 |
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| 293 | trace_thermal_power_allocator_pid(tz, frac_to_int(err),
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| 294 | frac_to_int(params->err_integral),
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| 295 | frac_to_int(p), frac_to_int(i),
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| 296 | frac_to_int(d), power_range);
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| 297 |
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| 298 | return power_range;
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| 299 | }
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| 300 |
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| 301 | |
| 302 | * power_actor_set_power() - limit the maximum power a cooling device consumes
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| 303 | * @cdev: pointer to &thermal_cooling_device
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| 304 | * @instance: thermal instance to update
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| 305 | * @power: the power in milliwatts
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| 306 | *
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| 307 | * Set the cooling device to consume at most @power milliwatts. The limit is
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| 308 | * expected to be a cap at the maximum power consumption.
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| 309 | *
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| 310 | * Return: 0 on success, -EINVAL if the cooling device does not
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| 311 | * implement the power actor API or -E* for other failures.
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| 312 |
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| 313 | static int
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| 314 | power_actor_set_power(struct thermal_cooling_device *cdev,
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| 315 | struct thermal_instance *instance, u32 power)
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| 316 | {
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| 317 | unsigned long state;
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| 318 | int ret;
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| 319 |
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| 320 | ret = cdev->ops->power2state(cdev, power, &state);
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| 321 | if (ret)
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| 322 | return ret;
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| 323 |
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| 324 | instance->target = clamp_val(state, instance->lower, instance->upper);
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| 325 |
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| 326 | thermal_cdev_update_nocheck(cdev);
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| 327 |
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| 328 | return 0;
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| 329 | }
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| 330 |
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| 331 | |
| 332 | * divvy_up_power() - divvy the allocated power between the actors
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| 333 | * @power: buffer for all power actors internal power information
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| 334 | * @num_actors: number of power actors in this thermal zone
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| 335 | * @total_req_power: sum of all weighted requested power for all actors
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| 336 | * @power_range: total allocated power
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| 337 | *
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| 338 | * This function divides the total allocated power (@power_range)
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| 339 | * fairly between the actors. It first tries to give each actor a
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| 340 | * share of the @power_range according to how much power it requested
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| 341 | * compared to the rest of the actors. For example, if only one actor
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| 342 | * requests power, then it receives all the @power_range. If
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| 343 | * three actors each requests 1mW, each receives a third of the
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| 344 | * @power_range.
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| 345 | *
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| 346 | * If any actor received more than their maximum power, then that
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| 347 | * surplus is re-divvied among the actors based on how far they are
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| 348 | * from their respective maximums.
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| 349 |
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| 350 | static void divvy_up_power(struct power_actor *power, int num_actors,
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| 351 | u32 total_req_power, u32 power_range)
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| 352 | {
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| 353 | u32 capped_extra_power = 0;
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| 354 | u32 extra_power = 0;
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| 355 | int i;
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| 356 |
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| 357 | if (!total_req_power) {
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| 358 | |
| 359 | * Nobody requested anything, just give everybody
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| 360 | * the maximum power
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| 361 |
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| 362 | for (i = 0; i < num_actors; i++) {
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| 363 | struct power_actor *pa = &power[i];
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| 364 |
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| 365 | pa->granted_power = pa->max_power;
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| 366 | }
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| 367 |
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| 368 | return;
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| 369 | }
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| 370 |
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| 371 | for (i = 0; i < num_actors; i++) {
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| 372 | struct power_actor *pa = &power[i];
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| 373 | u64 req_range = (u64)pa->weighted_req_power * power_range;
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| 374 |
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| 375 | pa->granted_power = DIV_ROUND_CLOSEST_ULL(req_range,
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| 376 | total_req_power);
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| 377 |
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| 378 | if (pa->granted_power > pa->max_power) {
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| 379 | extra_power += pa->granted_power - pa->max_power;
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| 380 | pa->granted_power = pa->max_power;
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| 381 | }
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| 382 |
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| 383 | pa->extra_actor_power = pa->max_power - pa->granted_power;
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| 384 | capped_extra_power += pa->extra_actor_power;
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| 385 | }
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| 386 |
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| 387 | if (!extra_power || !capped_extra_power)
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| 388 | return;
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| 389 |
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| 390 | |
| 391 | * Re-divvy the reclaimed extra among actors based on
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| 392 | * how far they are from the max
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| 393 |
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| 394 | extra_power = min(extra_power, capped_extra_power);
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| 395 |
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| 396 | for (i = 0; i < num_actors; i++) {
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| 397 | struct power_actor *pa = &power[i];
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| 398 | u64 extra_range = pa->extra_actor_power;
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| 399 |
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| 400 | extra_range *= extra_power;
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| 401 | pa->granted_power += DIV_ROUND_CLOSEST_ULL(extra_range,
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| 402 | capped_extra_power);
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| 403 | }
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| 404 | }
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| 405 |
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| 406 | static void allocate_power(struct thermal_zone_device *tz, int control_temp)
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| 407 | {
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| 408 | struct power_allocator_params *params = tz->governor_data;
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| 409 | const struct thermal_trip_desc *td = trip_to_trip_desc(params->trip_max);
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| 410 | unsigned int num_actors = params->num_actors;
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| 411 | struct power_actor *power = params->power;
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| 412 | struct thermal_cooling_device *cdev;
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| 413 | struct thermal_instance *instance;
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| 414 | u32 total_weighted_req_power = 0;
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| 415 | u32 max_allocatable_power = 0;
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| 416 | u32 total_granted_power = 0;
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| 417 | u32 total_req_power = 0;
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| 418 | u32 power_range, weight;
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| 419 | int i = 0, ret;
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| 420 |
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| 421 | if (!num_actors)
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| 422 | return;
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| 423 |
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| 424 |
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| 425 | memset(power, 0, params->buffer_size);
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| 426 |
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| 427 | list_for_each_entry(instance, &td->thermal_instances, trip_node) {
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| 428 | struct power_actor *pa = &power[i];
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| 429 |
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| 430 | if (!power_actor_is_valid(instance))
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| 431 | continue;
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| 432 |
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| 433 | cdev = instance->cdev;
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| 434 |
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| 435 | ret = cdev->ops->get_requested_power(cdev, &pa->req_power);
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| 436 | if (ret)
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| 437 | continue;
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| 438 |
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| 439 | if (!params->total_weight)
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| 440 | weight = 1 << FRAC_BITS;
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| 441 | else
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| 442 | weight = instance->weight;
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| 443 |
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| 444 | pa->weighted_req_power = frac_to_int(weight * pa->req_power);
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| 445 |
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| 446 | ret = cdev->ops->state2power(cdev, instance->lower,
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| 447 | &pa->max_power);
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| 448 | if (ret)
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| 449 | continue;
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| 450 |
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| 451 | total_req_power += pa->req_power;
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| 452 | max_allocatable_power += pa->max_power;
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| 453 | total_weighted_req_power += pa->weighted_req_power;
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| 454 |
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| 455 | i++;
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| 456 | }
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| 457 |
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| 458 | power_range = pid_controller(tz, control_temp, max_allocatable_power);
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| 459 |
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| 460 | divvy_up_power(power, num_actors, total_weighted_req_power,
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| 461 | power_range);
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| 462 |
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| 463 | i = 0;
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| 464 | list_for_each_entry(instance, &td->thermal_instances, trip_node) {
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| 465 | struct power_actor *pa = &power[i];
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| 466 |
|
| 467 | if (!power_actor_is_valid(instance))
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| 468 | continue;
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| 469 |
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| 470 | power_actor_set_power(instance->cdev, instance,
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| 471 | pa->granted_power);
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| 472 | total_granted_power += pa->granted_power;
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| 473 |
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| 474 | trace_thermal_power_actor(tz, i, pa->req_power,
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| 475 | pa->granted_power);
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| 476 | i++;
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| 477 | }
|
| 478 |
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| 479 | trace_thermal_power_allocator(tz, total_req_power, total_granted_power,
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| 480 | num_actors, power_range,
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| 481 | max_allocatable_power, tz->temperature,
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| 482 | control_temp - tz->temperature);
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| 483 | }
|
| 484 |
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| 485 | |
| 486 | * get_governor_trips() - get the two trip points that are key for this governor
|
| 487 | * @tz: thermal zone to operate on
|
| 488 | * @params: pointer to private data for this governor
|
| 489 | *
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| 490 | * The power allocator governor works optimally with two trips points:
|
| 491 | * a "switch on" trip point and a "maximum desired temperature". These
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| 492 | * are defined as the first and last passive trip points.
|
| 493 | *
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| 494 | * If there is only one trip point, then that's considered to be the
|
| 495 | * "maximum desired temperature" trip point and the governor is always
|
| 496 | * on. If there are no passive or active trip points, then the
|
| 497 | * governor won't do anything. In fact, its throttle function
|
| 498 | * won't be called at all.
|
| 499 |
|
| 500 | static void get_governor_trips(struct thermal_zone_device *tz,
|
| 501 | struct power_allocator_params *params)
|
| 502 | {
|
| 503 | const struct thermal_trip *first_passive = NULL;
|
| 504 | const struct thermal_trip *last_passive = NULL;
|
| 505 | const struct thermal_trip *last_active = NULL;
|
| 506 | const struct thermal_trip_desc *td;
|
| 507 |
|
| 508 | for_each_trip_desc(tz, td) {
|
| 509 | const struct thermal_trip *trip = &td->trip;
|
| 510 |
|
| 511 | switch (trip->type) {
|
| 512 | case THERMAL_TRIP_PASSIVE:
|
| 513 | if (!first_passive) {
|
| 514 | first_passive = trip;
|
| 515 | break;
|
| 516 | }
|
| 517 | last_passive = trip;
|
| 518 | break;
|
| 519 | case THERMAL_TRIP_ACTIVE:
|
| 520 | last_active = trip;
|
| 521 | break;
|
| 522 | default:
|
| 523 | break;
|
| 524 | }
|
| 525 | }
|
| 526 |
|
| 527 | if (last_passive) {
|
| 528 | params->trip_switch_on = first_passive;
|
| 529 | params->trip_max = last_passive;
|
| 530 | } else if (first_passive) {
|
| 531 | params->trip_switch_on = NULL;
|
| 532 | params->trip_max = first_passive;
|
| 533 | } else {
|
| 534 | params->trip_switch_on = NULL;
|
| 535 | params->trip_max = last_active;
|
| 536 | }
|
| 537 | }
|
| 538 |
|
| 539 | static void reset_pid_controller(struct power_allocator_params *params)
|
| 540 | {
|
| 541 | params->err_integral = 0;
|
| 542 | params->prev_err = 0;
|
| 543 | }
|
| 544 |
|
| 545 | static void allow_maximum_power(struct thermal_zone_device *tz)
|
| 546 | {
|
| 547 | struct power_allocator_params *params = tz->governor_data;
|
| 548 | const struct thermal_trip_desc *td = trip_to_trip_desc(params->trip_max);
|
| 549 | struct thermal_cooling_device *cdev;
|
| 550 | struct thermal_instance *instance;
|
| 551 | u32 req_power;
|
| 552 |
|
| 553 | list_for_each_entry(instance, &td->thermal_instances, trip_node) {
|
| 554 | if (!power_actor_is_valid(instance))
|
| 555 | continue;
|
| 556 |
|
| 557 | cdev = instance->cdev;
|
| 558 |
|
| 559 | instance->target = 0;
|
| 560 | scoped_guard(cooling_dev, cdev) {
|
| 561 | |
| 562 | * Call for updating the cooling devices local stats and
|
| 563 | * avoid periods of dozen of seconds when those have not
|
| 564 | * been maintained.
|
| 565 |
|
| 566 | cdev->ops->get_requested_power(cdev, &req_power);
|
| 567 |
|
| 568 | if (params->update_cdevs)
|
| 569 | __thermal_cdev_update(cdev);
|
| 570 | }
|
| 571 | }
|
| 572 | }
|
| 573 |
|
| 574 | |
| 575 | * check_power_actors() - Check all cooling devices and warn when they are
|
| 576 | * not power actors
|
| 577 | * @tz: thermal zone to operate on
|
| 578 | * @params: power allocator private data
|
| 579 | *
|
| 580 | * Check all cooling devices in the @tz and warn every time they are missing
|
| 581 | * power actor API. The warning should help to investigate the issue, which
|
| 582 | * could be e.g. lack of Energy Model for a given device.
|
| 583 | *
|
| 584 | * If all of the cooling devices currently attached to @tz implement the power
|
| 585 | * actor API, return the number of them (which may be 0, because some cooling
|
| 586 | * devices may be attached later). Otherwise, return -EINVAL.
|
| 587 |
|
| 588 | static int check_power_actors(struct thermal_zone_device *tz,
|
| 589 | struct power_allocator_params *params)
|
| 590 | {
|
| 591 | const struct thermal_trip_desc *td;
|
| 592 | struct thermal_instance *instance;
|
| 593 | int ret = 0;
|
| 594 |
|
| 595 | if (!params->trip_max)
|
| 596 | return 0;
|
| 597 |
|
| 598 | td = trip_to_trip_desc(params->trip_max);
|
| 599 |
|
| 600 | list_for_each_entry(instance, &td->thermal_instances, trip_node) {
|
| 601 | if (!cdev_is_power_actor(instance->cdev)) {
|
| 602 | dev_warn(&tz->device, "power_allocator: %s is not a power actor\n",
|
| 603 | instance->cdev->type);
|
| 604 | return -EINVAL;
|
| 605 | }
|
| 606 | ret++;
|
| 607 | }
|
| 608 |
|
| 609 | return ret;
|
| 610 | }
|
| 611 |
|
| 612 | static int allocate_actors_buffer(struct power_allocator_params *params,
|
| 613 | int num_actors)
|
| 614 | {
|
| 615 | int ret;
|
| 616 |
|
| 617 | kfree(params->power);
|
| 618 |
|
| 619 |
|
| 620 | if (!num_actors) {
|
| 621 | ret = 0;
|
| 622 | goto clean_state;
|
| 623 | }
|
| 624 |
|
| 625 | params->power = kzalloc_objs(struct power_actor, num_actors);
|
| 626 | if (!params->power) {
|
| 627 | ret = -ENOMEM;
|
| 628 | goto clean_state;
|
| 629 | }
|
| 630 |
|
| 631 | params->num_actors = num_actors;
|
| 632 | params->buffer_size = num_actors * sizeof(struct power_actor);
|
| 633 |
|
| 634 | return 0;
|
| 635 |
|
| 636 | clean_state:
|
| 637 | params->num_actors = 0;
|
| 638 | params->buffer_size = 0;
|
| 639 | params->power = NULL;
|
| 640 | return ret;
|
| 641 | }
|
| 642 |
|
| 643 | static void power_allocator_update_weight(struct power_allocator_params *params)
|
| 644 | {
|
| 645 | const struct thermal_trip_desc *td;
|
| 646 | struct thermal_instance *instance;
|
| 647 |
|
| 648 | if (!params->trip_max)
|
| 649 | return;
|
| 650 |
|
| 651 | td = trip_to_trip_desc(params->trip_max);
|
| 652 |
|
| 653 | params->total_weight = 0;
|
| 654 | list_for_each_entry(instance, &td->thermal_instances, trip_node)
|
| 655 | if (power_actor_is_valid(instance))
|
| 656 | params->total_weight += instance->weight;
|
| 657 | }
|
| 658 |
|
| 659 | static void power_allocator_update_tz(struct thermal_zone_device *tz,
|
| 660 | enum thermal_notify_event reason)
|
| 661 | {
|
| 662 | struct power_allocator_params *params = tz->governor_data;
|
| 663 | const struct thermal_trip_desc *td = trip_to_trip_desc(params->trip_max);
|
| 664 | struct thermal_instance *instance;
|
| 665 | int num_actors = 0;
|
| 666 |
|
| 667 | switch (reason) {
|
| 668 | case THERMAL_TZ_BIND_CDEV:
|
| 669 | case THERMAL_TZ_UNBIND_CDEV:
|
| 670 | list_for_each_entry(instance, &td->thermal_instances, trip_node)
|
| 671 | if (power_actor_is_valid(instance))
|
| 672 | num_actors++;
|
| 673 |
|
| 674 | if (num_actors != params->num_actors)
|
| 675 | allocate_actors_buffer(params, num_actors);
|
| 676 |
|
| 677 | fallthrough;
|
| 678 | case THERMAL_INSTANCE_WEIGHT_CHANGED:
|
| 679 | power_allocator_update_weight(params);
|
| 680 | break;
|
| 681 | default:
|
| 682 | break;
|
| 683 | }
|
| 684 | }
|
| 685 |
|
| 686 | |
| 687 | * power_allocator_bind() - bind the power_allocator governor to a thermal zone
|
| 688 | * @tz: thermal zone to bind it to
|
| 689 | *
|
| 690 | * Initialize the PID controller parameters and bind it to the thermal
|
| 691 | * zone.
|
| 692 | *
|
| 693 | * Return: 0 on success, or -ENOMEM if we ran out of memory, or -EINVAL
|
| 694 | * when there are unsupported cooling devices in the @tz.
|
| 695 |
|
| 696 | static int power_allocator_bind(struct thermal_zone_device *tz)
|
| 697 | {
|
| 698 | struct power_allocator_params *params;
|
| 699 | int ret;
|
| 700 |
|
| 701 | params = kzalloc_obj(*params);
|
| 702 | if (!params)
|
| 703 | return -ENOMEM;
|
| 704 |
|
| 705 | get_governor_trips(tz, params);
|
| 706 |
|
| 707 | ret = check_power_actors(tz, params);
|
| 708 | if (ret < 0) {
|
| 709 | dev_warn(&tz->device, "power_allocator: binding failed\n");
|
| 710 | kfree(params);
|
| 711 | return ret;
|
| 712 | }
|
| 713 |
|
| 714 | ret = allocate_actors_buffer(params, ret);
|
| 715 | if (ret) {
|
| 716 | dev_warn(&tz->device, "power_allocator: allocation failed\n");
|
| 717 | kfree(params);
|
| 718 | return ret;
|
| 719 | }
|
| 720 |
|
| 721 | if (!tz->tzp) {
|
| 722 | tz->tzp = kzalloc_obj(*tz->tzp);
|
| 723 | if (!tz->tzp) {
|
| 724 | ret = -ENOMEM;
|
| 725 | goto free_params;
|
| 726 | }
|
| 727 |
|
| 728 | params->allocated_tzp = true;
|
| 729 | }
|
| 730 |
|
| 731 | if (!tz->tzp->sustainable_power)
|
| 732 | dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n");
|
| 733 | else
|
| 734 | params->sustainable_power = tz->tzp->sustainable_power;
|
| 735 |
|
| 736 | if (params->trip_max)
|
| 737 | estimate_pid_constants(tz, tz->tzp->sustainable_power,
|
| 738 | params->trip_switch_on,
|
| 739 | params->trip_max->temperature);
|
| 740 |
|
| 741 | reset_pid_controller(params);
|
| 742 |
|
| 743 | tz->governor_data = params;
|
| 744 |
|
| 745 | power_allocator_update_weight(params);
|
| 746 |
|
| 747 | return 0;
|
| 748 |
|
| 749 | free_params:
|
| 750 | kfree(params->power);
|
| 751 | kfree(params);
|
| 752 |
|
| 753 | return ret;
|
| 754 | }
|
| 755 |
|
| 756 | static void power_allocator_unbind(struct thermal_zone_device *tz)
|
| 757 | {
|
| 758 | struct power_allocator_params *params = tz->governor_data;
|
| 759 |
|
| 760 | dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id);
|
| 761 |
|
| 762 | if (params->allocated_tzp) {
|
| 763 | kfree(tz->tzp);
|
| 764 | tz->tzp = NULL;
|
| 765 | }
|
| 766 |
|
| 767 | kfree(params->power);
|
| 768 | kfree(tz->governor_data);
|
| 769 | tz->governor_data = NULL;
|
| 770 | }
|
| 771 |
|
| 772 | static void power_allocator_manage(struct thermal_zone_device *tz)
|
| 773 | {
|
| 774 | struct power_allocator_params *params = tz->governor_data;
|
| 775 | const struct thermal_trip *trip = params->trip_switch_on;
|
| 776 |
|
| 777 | lockdep_assert_held(&tz->lock);
|
| 778 |
|
| 779 | if (trip && tz->temperature < trip->temperature) {
|
| 780 | reset_pid_controller(params);
|
| 781 | allow_maximum_power(tz);
|
| 782 | params->update_cdevs = false;
|
| 783 | return;
|
| 784 | }
|
| 785 |
|
| 786 | if (!params->trip_max)
|
| 787 | return;
|
| 788 |
|
| 789 | allocate_power(tz, params->trip_max->temperature);
|
| 790 | params->update_cdevs = true;
|
| 791 | }
|
| 792 |
|
| 793 | static struct thermal_governor thermal_gov_power_allocator = {
|
| 794 | .name = "power_allocator",
|
| 795 | .bind_to_tz = power_allocator_bind,
|
| 796 | .unbind_from_tz = power_allocator_unbind,
|
| 797 | .manage = power_allocator_manage,
|
| 798 | .update_tz = power_allocator_update_tz,
|
| 799 | };
|
| 800 | THERMAL_GOVERNOR_DECLARE(thermal_gov_power_allocator);
|