mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Lukasz Luba](/assets/img/avatar_default.png)
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/20210422153624.6074-4-lukasz.luba@arm.com
752 lines
21 KiB
C
752 lines
21 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* A power allocator to manage temperature
|
|
*
|
|
* Copyright (C) 2014 ARM Ltd.
|
|
*
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "Power allocator: " fmt
|
|
|
|
#include <linux/rculist.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/thermal.h>
|
|
|
|
#define CREATE_TRACE_POINTS
|
|
#include <trace/events/thermal_power_allocator.h>
|
|
|
|
#include "thermal_core.h"
|
|
|
|
#define INVALID_TRIP -1
|
|
|
|
#define FRAC_BITS 10
|
|
#define int_to_frac(x) ((x) << FRAC_BITS)
|
|
#define frac_to_int(x) ((x) >> FRAC_BITS)
|
|
|
|
/**
|
|
* mul_frac() - multiply two fixed-point numbers
|
|
* @x: first multiplicand
|
|
* @y: second multiplicand
|
|
*
|
|
* Return: the result of multiplying two fixed-point numbers. The
|
|
* result is also a fixed-point number.
|
|
*/
|
|
static inline s64 mul_frac(s64 x, s64 y)
|
|
{
|
|
return (x * y) >> FRAC_BITS;
|
|
}
|
|
|
|
/**
|
|
* div_frac() - divide two fixed-point numbers
|
|
* @x: the dividend
|
|
* @y: the divisor
|
|
*
|
|
* Return: the result of dividing two fixed-point numbers. The
|
|
* result is also a fixed-point number.
|
|
*/
|
|
static inline s64 div_frac(s64 x, s64 y)
|
|
{
|
|
return div_s64(x << FRAC_BITS, y);
|
|
}
|
|
|
|
/**
|
|
* struct power_allocator_params - parameters for the power allocator governor
|
|
* @allocated_tzp: whether we have allocated tzp for this thermal zone and
|
|
* it needs to be freed on unbind
|
|
* @err_integral: accumulated error in the PID controller.
|
|
* @prev_err: error in the previous iteration of the PID controller.
|
|
* Used to calculate the derivative term.
|
|
* @trip_switch_on: first passive trip point of the thermal zone. The
|
|
* governor switches on when this trip point is crossed.
|
|
* If the thermal zone only has one passive trip point,
|
|
* @trip_switch_on should be INVALID_TRIP.
|
|
* @trip_max_desired_temperature: last passive trip point of the thermal
|
|
* zone. The temperature we are
|
|
* controlling for.
|
|
* @sustainable_power: Sustainable power (heat) that this thermal zone can
|
|
* dissipate
|
|
*/
|
|
struct power_allocator_params {
|
|
bool allocated_tzp;
|
|
s64 err_integral;
|
|
s32 prev_err;
|
|
int trip_switch_on;
|
|
int trip_max_desired_temperature;
|
|
u32 sustainable_power;
|
|
};
|
|
|
|
/**
|
|
* estimate_sustainable_power() - Estimate the sustainable power of a thermal zone
|
|
* @tz: thermal zone we are operating in
|
|
*
|
|
* For thermal zones that don't provide a sustainable_power in their
|
|
* thermal_zone_params, estimate one. Calculate it using the minimum
|
|
* power of all the cooling devices as that gives a valid value that
|
|
* can give some degree of functionality. For optimal performance of
|
|
* this governor, provide a sustainable_power in the thermal zone's
|
|
* thermal_zone_params.
|
|
*/
|
|
static u32 estimate_sustainable_power(struct thermal_zone_device *tz)
|
|
{
|
|
u32 sustainable_power = 0;
|
|
struct thermal_instance *instance;
|
|
struct power_allocator_params *params = tz->governor_data;
|
|
|
|
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
|
|
struct thermal_cooling_device *cdev = instance->cdev;
|
|
u32 min_power;
|
|
|
|
if (instance->trip != params->trip_max_desired_temperature)
|
|
continue;
|
|
|
|
if (!cdev_is_power_actor(cdev))
|
|
continue;
|
|
|
|
if (cdev->ops->state2power(cdev, instance->upper, &min_power))
|
|
continue;
|
|
|
|
sustainable_power += min_power;
|
|
}
|
|
|
|
return sustainable_power;
|
|
}
|
|
|
|
/**
|
|
* estimate_pid_constants() - Estimate the constants for the PID controller
|
|
* @tz: thermal zone for which to estimate the constants
|
|
* @sustainable_power: sustainable power for the thermal zone
|
|
* @trip_switch_on: trip point number for the switch on temperature
|
|
* @control_temp: target temperature for the power allocator governor
|
|
*
|
|
* This function is used to update the estimation of the PID
|
|
* controller constants in struct thermal_zone_parameters.
|
|
*/
|
|
static void estimate_pid_constants(struct thermal_zone_device *tz,
|
|
u32 sustainable_power, int trip_switch_on,
|
|
int control_temp)
|
|
{
|
|
int ret;
|
|
int switch_on_temp;
|
|
u32 temperature_threshold;
|
|
s32 k_i;
|
|
|
|
ret = tz->ops->get_trip_temp(tz, trip_switch_on, &switch_on_temp);
|
|
if (ret)
|
|
switch_on_temp = 0;
|
|
|
|
temperature_threshold = control_temp - switch_on_temp;
|
|
/*
|
|
* estimate_pid_constants() tries to find appropriate default
|
|
* values for thermal zones that don't provide them. If a
|
|
* system integrator has configured a thermal zone with two
|
|
* passive trip points at the same temperature, that person
|
|
* hasn't put any effort to set up the thermal zone properly
|
|
* so just give up.
|
|
*/
|
|
if (!temperature_threshold)
|
|
return;
|
|
|
|
tz->tzp->k_po = int_to_frac(sustainable_power) /
|
|
temperature_threshold;
|
|
|
|
tz->tzp->k_pu = int_to_frac(2 * sustainable_power) /
|
|
temperature_threshold;
|
|
|
|
k_i = tz->tzp->k_pu / 10;
|
|
tz->tzp->k_i = k_i > 0 ? k_i : 1;
|
|
|
|
/*
|
|
* The default for k_d and integral_cutoff is 0, so we can
|
|
* leave them as they are.
|
|
*/
|
|
}
|
|
|
|
/**
|
|
* get_sustainable_power() - Get the right sustainable power
|
|
* @tz: thermal zone for which to estimate the constants
|
|
* @params: parameters for the power allocator governor
|
|
* @control_temp: target temperature for the power allocator governor
|
|
*
|
|
* This function is used for getting the proper sustainable power value based
|
|
* on variables which might be updated by the user sysfs interface. If that
|
|
* happen the new value is going to be estimated and updated. It is also used
|
|
* after thermal zone binding, where the initial values where set to 0.
|
|
*/
|
|
static u32 get_sustainable_power(struct thermal_zone_device *tz,
|
|
struct power_allocator_params *params,
|
|
int control_temp)
|
|
{
|
|
u32 sustainable_power;
|
|
|
|
if (!tz->tzp->sustainable_power)
|
|
sustainable_power = estimate_sustainable_power(tz);
|
|
else
|
|
sustainable_power = tz->tzp->sustainable_power;
|
|
|
|
/* Check if it's init value 0 or there was update via sysfs */
|
|
if (sustainable_power != params->sustainable_power) {
|
|
estimate_pid_constants(tz, sustainable_power,
|
|
params->trip_switch_on, control_temp);
|
|
|
|
/* Do the estimation only once and make available in sysfs */
|
|
tz->tzp->sustainable_power = sustainable_power;
|
|
params->sustainable_power = sustainable_power;
|
|
}
|
|
|
|
return sustainable_power;
|
|
}
|
|
|
|
/**
|
|
* pid_controller() - PID controller
|
|
* @tz: thermal zone we are operating in
|
|
* @control_temp: the target temperature in millicelsius
|
|
* @max_allocatable_power: maximum allocatable power for this thermal zone
|
|
*
|
|
* This PID controller increases the available power budget so that the
|
|
* temperature of the thermal zone gets as close as possible to
|
|
* @control_temp and limits the power if it exceeds it. k_po is the
|
|
* proportional term when we are overshooting, k_pu is the
|
|
* proportional term when we are undershooting. integral_cutoff is a
|
|
* threshold below which we stop accumulating the error. The
|
|
* accumulated error is only valid if the requested power will make
|
|
* the system warmer. If the system is mostly idle, there's no point
|
|
* in accumulating positive error.
|
|
*
|
|
* Return: The power budget for the next period.
|
|
*/
|
|
static u32 pid_controller(struct thermal_zone_device *tz,
|
|
int control_temp,
|
|
u32 max_allocatable_power)
|
|
{
|
|
s64 p, i, d, power_range;
|
|
s32 err, max_power_frac;
|
|
u32 sustainable_power;
|
|
struct power_allocator_params *params = tz->governor_data;
|
|
|
|
max_power_frac = int_to_frac(max_allocatable_power);
|
|
|
|
sustainable_power = get_sustainable_power(tz, params, control_temp);
|
|
|
|
err = control_temp - tz->temperature;
|
|
err = int_to_frac(err);
|
|
|
|
/* Calculate the proportional term */
|
|
p = mul_frac(err < 0 ? tz->tzp->k_po : tz->tzp->k_pu, err);
|
|
|
|
/*
|
|
* Calculate the integral term
|
|
*
|
|
* if the error is less than cut off allow integration (but
|
|
* the integral is limited to max power)
|
|
*/
|
|
i = mul_frac(tz->tzp->k_i, params->err_integral);
|
|
|
|
if (err < int_to_frac(tz->tzp->integral_cutoff)) {
|
|
s64 i_next = i + mul_frac(tz->tzp->k_i, err);
|
|
|
|
if (abs(i_next) < max_power_frac) {
|
|
i = i_next;
|
|
params->err_integral += err;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Calculate the derivative term
|
|
*
|
|
* We do err - prev_err, so with a positive k_d, a decreasing
|
|
* error (i.e. driving closer to the line) results in less
|
|
* power being applied, slowing down the controller)
|
|
*/
|
|
d = mul_frac(tz->tzp->k_d, err - params->prev_err);
|
|
d = div_frac(d, jiffies_to_msecs(tz->passive_delay_jiffies));
|
|
params->prev_err = err;
|
|
|
|
power_range = p + i + d;
|
|
|
|
/* feed-forward the known sustainable dissipatable power */
|
|
power_range = sustainable_power + frac_to_int(power_range);
|
|
|
|
power_range = clamp(power_range, (s64)0, (s64)max_allocatable_power);
|
|
|
|
trace_thermal_power_allocator_pid(tz, frac_to_int(err),
|
|
frac_to_int(params->err_integral),
|
|
frac_to_int(p), frac_to_int(i),
|
|
frac_to_int(d), power_range);
|
|
|
|
return power_range;
|
|
}
|
|
|
|
/**
|
|
* power_actor_set_power() - limit the maximum power a cooling device consumes
|
|
* @cdev: pointer to &thermal_cooling_device
|
|
* @instance: thermal instance to update
|
|
* @power: the power in milliwatts
|
|
*
|
|
* Set the cooling device to consume at most @power milliwatts. The limit is
|
|
* expected to be a cap at the maximum power consumption.
|
|
*
|
|
* Return: 0 on success, -EINVAL if the cooling device does not
|
|
* implement the power actor API or -E* for other failures.
|
|
*/
|
|
static int
|
|
power_actor_set_power(struct thermal_cooling_device *cdev,
|
|
struct thermal_instance *instance, u32 power)
|
|
{
|
|
unsigned long state;
|
|
int ret;
|
|
|
|
ret = cdev->ops->power2state(cdev, power, &state);
|
|
if (ret)
|
|
return ret;
|
|
|
|
instance->target = clamp_val(state, instance->lower, instance->upper);
|
|
mutex_lock(&cdev->lock);
|
|
__thermal_cdev_update(cdev);
|
|
mutex_unlock(&cdev->lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* divvy_up_power() - divvy the allocated power between the actors
|
|
* @req_power: each actor's requested power
|
|
* @max_power: each actor's maximum available power
|
|
* @num_actors: size of the @req_power, @max_power and @granted_power's array
|
|
* @total_req_power: sum of @req_power
|
|
* @power_range: total allocated power
|
|
* @granted_power: output array: each actor's granted power
|
|
* @extra_actor_power: an appropriately sized array to be used in the
|
|
* function as temporary storage of the extra power given
|
|
* to the actors
|
|
*
|
|
* This function divides the total allocated power (@power_range)
|
|
* fairly between the actors. It first tries to give each actor a
|
|
* share of the @power_range according to how much power it requested
|
|
* compared to the rest of the actors. For example, if only one actor
|
|
* requests power, then it receives all the @power_range. If
|
|
* three actors each requests 1mW, each receives a third of the
|
|
* @power_range.
|
|
*
|
|
* If any actor received more than their maximum power, then that
|
|
* surplus is re-divvied among the actors based on how far they are
|
|
* from their respective maximums.
|
|
*
|
|
* Granted power for each actor is written to @granted_power, which
|
|
* should've been allocated by the calling function.
|
|
*/
|
|
static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors,
|
|
u32 total_req_power, u32 power_range,
|
|
u32 *granted_power, u32 *extra_actor_power)
|
|
{
|
|
u32 extra_power, capped_extra_power;
|
|
int i;
|
|
|
|
/*
|
|
* Prevent division by 0 if none of the actors request power.
|
|
*/
|
|
if (!total_req_power)
|
|
total_req_power = 1;
|
|
|
|
capped_extra_power = 0;
|
|
extra_power = 0;
|
|
for (i = 0; i < num_actors; i++) {
|
|
u64 req_range = (u64)req_power[i] * power_range;
|
|
|
|
granted_power[i] = DIV_ROUND_CLOSEST_ULL(req_range,
|
|
total_req_power);
|
|
|
|
if (granted_power[i] > max_power[i]) {
|
|
extra_power += granted_power[i] - max_power[i];
|
|
granted_power[i] = max_power[i];
|
|
}
|
|
|
|
extra_actor_power[i] = max_power[i] - granted_power[i];
|
|
capped_extra_power += extra_actor_power[i];
|
|
}
|
|
|
|
if (!extra_power)
|
|
return;
|
|
|
|
/*
|
|
* Re-divvy the reclaimed extra among actors based on
|
|
* how far they are from the max
|
|
*/
|
|
extra_power = min(extra_power, capped_extra_power);
|
|
if (capped_extra_power > 0)
|
|
for (i = 0; i < num_actors; i++) {
|
|
u64 extra_range = (u64)extra_actor_power[i] * extra_power;
|
|
granted_power[i] += DIV_ROUND_CLOSEST_ULL(extra_range,
|
|
capped_extra_power);
|
|
}
|
|
}
|
|
|
|
static int allocate_power(struct thermal_zone_device *tz,
|
|
int control_temp)
|
|
{
|
|
struct thermal_instance *instance;
|
|
struct power_allocator_params *params = tz->governor_data;
|
|
u32 *req_power, *max_power, *granted_power, *extra_actor_power;
|
|
u32 *weighted_req_power;
|
|
u32 total_req_power, max_allocatable_power, total_weighted_req_power;
|
|
u32 total_granted_power, power_range;
|
|
int i, num_actors, total_weight, ret = 0;
|
|
int trip_max_desired_temperature = params->trip_max_desired_temperature;
|
|
|
|
mutex_lock(&tz->lock);
|
|
|
|
num_actors = 0;
|
|
total_weight = 0;
|
|
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
|
|
if ((instance->trip == trip_max_desired_temperature) &&
|
|
cdev_is_power_actor(instance->cdev)) {
|
|
num_actors++;
|
|
total_weight += instance->weight;
|
|
}
|
|
}
|
|
|
|
if (!num_actors) {
|
|
ret = -ENODEV;
|
|
goto unlock;
|
|
}
|
|
|
|
/*
|
|
* We need to allocate five arrays of the same size:
|
|
* req_power, max_power, granted_power, extra_actor_power and
|
|
* weighted_req_power. They are going to be needed until this
|
|
* function returns. Allocate them all in one go to simplify
|
|
* the allocation and deallocation logic.
|
|
*/
|
|
BUILD_BUG_ON(sizeof(*req_power) != sizeof(*max_power));
|
|
BUILD_BUG_ON(sizeof(*req_power) != sizeof(*granted_power));
|
|
BUILD_BUG_ON(sizeof(*req_power) != sizeof(*extra_actor_power));
|
|
BUILD_BUG_ON(sizeof(*req_power) != sizeof(*weighted_req_power));
|
|
req_power = kcalloc(num_actors * 5, sizeof(*req_power), GFP_KERNEL);
|
|
if (!req_power) {
|
|
ret = -ENOMEM;
|
|
goto unlock;
|
|
}
|
|
|
|
max_power = &req_power[num_actors];
|
|
granted_power = &req_power[2 * num_actors];
|
|
extra_actor_power = &req_power[3 * num_actors];
|
|
weighted_req_power = &req_power[4 * num_actors];
|
|
|
|
i = 0;
|
|
total_weighted_req_power = 0;
|
|
total_req_power = 0;
|
|
max_allocatable_power = 0;
|
|
|
|
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
|
|
int weight;
|
|
struct thermal_cooling_device *cdev = instance->cdev;
|
|
|
|
if (instance->trip != trip_max_desired_temperature)
|
|
continue;
|
|
|
|
if (!cdev_is_power_actor(cdev))
|
|
continue;
|
|
|
|
if (cdev->ops->get_requested_power(cdev, &req_power[i]))
|
|
continue;
|
|
|
|
if (!total_weight)
|
|
weight = 1 << FRAC_BITS;
|
|
else
|
|
weight = instance->weight;
|
|
|
|
weighted_req_power[i] = frac_to_int(weight * req_power[i]);
|
|
|
|
if (cdev->ops->state2power(cdev, instance->lower,
|
|
&max_power[i]))
|
|
continue;
|
|
|
|
total_req_power += req_power[i];
|
|
max_allocatable_power += max_power[i];
|
|
total_weighted_req_power += weighted_req_power[i];
|
|
|
|
i++;
|
|
}
|
|
|
|
power_range = pid_controller(tz, control_temp, max_allocatable_power);
|
|
|
|
divvy_up_power(weighted_req_power, max_power, num_actors,
|
|
total_weighted_req_power, power_range, granted_power,
|
|
extra_actor_power);
|
|
|
|
total_granted_power = 0;
|
|
i = 0;
|
|
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
|
|
if (instance->trip != trip_max_desired_temperature)
|
|
continue;
|
|
|
|
if (!cdev_is_power_actor(instance->cdev))
|
|
continue;
|
|
|
|
power_actor_set_power(instance->cdev, instance,
|
|
granted_power[i]);
|
|
total_granted_power += granted_power[i];
|
|
|
|
i++;
|
|
}
|
|
|
|
trace_thermal_power_allocator(tz, req_power, total_req_power,
|
|
granted_power, total_granted_power,
|
|
num_actors, power_range,
|
|
max_allocatable_power, tz->temperature,
|
|
control_temp - tz->temperature);
|
|
|
|
kfree(req_power);
|
|
unlock:
|
|
mutex_unlock(&tz->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* get_governor_trips() - get the number of the two trip points that are key for this governor
|
|
* @tz: thermal zone to operate on
|
|
* @params: pointer to private data for this governor
|
|
*
|
|
* The power allocator governor works optimally with two trips points:
|
|
* a "switch on" trip point and a "maximum desired temperature". These
|
|
* are defined as the first and last passive trip points.
|
|
*
|
|
* If there is only one trip point, then that's considered to be the
|
|
* "maximum desired temperature" trip point and the governor is always
|
|
* on. If there are no passive or active trip points, then the
|
|
* governor won't do anything. In fact, its throttle function
|
|
* won't be called at all.
|
|
*/
|
|
static void get_governor_trips(struct thermal_zone_device *tz,
|
|
struct power_allocator_params *params)
|
|
{
|
|
int i, last_active, last_passive;
|
|
bool found_first_passive;
|
|
|
|
found_first_passive = false;
|
|
last_active = INVALID_TRIP;
|
|
last_passive = INVALID_TRIP;
|
|
|
|
for (i = 0; i < tz->trips; i++) {
|
|
enum thermal_trip_type type;
|
|
int ret;
|
|
|
|
ret = tz->ops->get_trip_type(tz, i, &type);
|
|
if (ret) {
|
|
dev_warn(&tz->device,
|
|
"Failed to get trip point %d type: %d\n", i,
|
|
ret);
|
|
continue;
|
|
}
|
|
|
|
if (type == THERMAL_TRIP_PASSIVE) {
|
|
if (!found_first_passive) {
|
|
params->trip_switch_on = i;
|
|
found_first_passive = true;
|
|
} else {
|
|
last_passive = i;
|
|
}
|
|
} else if (type == THERMAL_TRIP_ACTIVE) {
|
|
last_active = i;
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (last_passive != INVALID_TRIP) {
|
|
params->trip_max_desired_temperature = last_passive;
|
|
} else if (found_first_passive) {
|
|
params->trip_max_desired_temperature = params->trip_switch_on;
|
|
params->trip_switch_on = INVALID_TRIP;
|
|
} else {
|
|
params->trip_switch_on = INVALID_TRIP;
|
|
params->trip_max_desired_temperature = last_active;
|
|
}
|
|
}
|
|
|
|
static void reset_pid_controller(struct power_allocator_params *params)
|
|
{
|
|
params->err_integral = 0;
|
|
params->prev_err = 0;
|
|
}
|
|
|
|
static void allow_maximum_power(struct thermal_zone_device *tz, bool update)
|
|
{
|
|
struct thermal_instance *instance;
|
|
struct power_allocator_params *params = tz->governor_data;
|
|
u32 req_power;
|
|
|
|
mutex_lock(&tz->lock);
|
|
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
|
|
struct thermal_cooling_device *cdev = instance->cdev;
|
|
|
|
if ((instance->trip != params->trip_max_desired_temperature) ||
|
|
(!cdev_is_power_actor(instance->cdev)))
|
|
continue;
|
|
|
|
instance->target = 0;
|
|
mutex_lock(&instance->cdev->lock);
|
|
/*
|
|
* Call for updating the cooling devices local stats and avoid
|
|
* periods of dozen of seconds when those have not been
|
|
* maintained.
|
|
*/
|
|
cdev->ops->get_requested_power(cdev, &req_power);
|
|
|
|
if (update)
|
|
__thermal_cdev_update(instance->cdev);
|
|
|
|
mutex_unlock(&instance->cdev->lock);
|
|
}
|
|
mutex_unlock(&tz->lock);
|
|
}
|
|
|
|
/**
|
|
* check_power_actors() - Check all cooling devices and warn when they are
|
|
* not power actors
|
|
* @tz: thermal zone to operate on
|
|
*
|
|
* Check all cooling devices in the @tz and warn every time they are missing
|
|
* power actor API. The warning should help to investigate the issue, which
|
|
* could be e.g. lack of Energy Model for a given device.
|
|
*
|
|
* Return: 0 on success, -EINVAL if any cooling device does not implement
|
|
* the power actor API.
|
|
*/
|
|
static int check_power_actors(struct thermal_zone_device *tz)
|
|
{
|
|
struct thermal_instance *instance;
|
|
int ret = 0;
|
|
|
|
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
|
|
if (!cdev_is_power_actor(instance->cdev)) {
|
|
dev_warn(&tz->device, "power_allocator: %s is not a power actor\n",
|
|
instance->cdev->type);
|
|
ret = -EINVAL;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* power_allocator_bind() - bind the power_allocator governor to a thermal zone
|
|
* @tz: thermal zone to bind it to
|
|
*
|
|
* Initialize the PID controller parameters and bind it to the thermal
|
|
* zone.
|
|
*
|
|
* Return: 0 on success, or -ENOMEM if we ran out of memory, or -EINVAL
|
|
* when there are unsupported cooling devices in the @tz.
|
|
*/
|
|
static int power_allocator_bind(struct thermal_zone_device *tz)
|
|
{
|
|
int ret;
|
|
struct power_allocator_params *params;
|
|
int control_temp;
|
|
|
|
ret = check_power_actors(tz);
|
|
if (ret)
|
|
return ret;
|
|
|
|
params = kzalloc(sizeof(*params), GFP_KERNEL);
|
|
if (!params)
|
|
return -ENOMEM;
|
|
|
|
if (!tz->tzp) {
|
|
tz->tzp = kzalloc(sizeof(*tz->tzp), GFP_KERNEL);
|
|
if (!tz->tzp) {
|
|
ret = -ENOMEM;
|
|
goto free_params;
|
|
}
|
|
|
|
params->allocated_tzp = true;
|
|
}
|
|
|
|
if (!tz->tzp->sustainable_power)
|
|
dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n");
|
|
|
|
get_governor_trips(tz, params);
|
|
|
|
if (tz->trips > 0) {
|
|
ret = tz->ops->get_trip_temp(tz,
|
|
params->trip_max_desired_temperature,
|
|
&control_temp);
|
|
if (!ret)
|
|
estimate_pid_constants(tz, tz->tzp->sustainable_power,
|
|
params->trip_switch_on,
|
|
control_temp);
|
|
}
|
|
|
|
reset_pid_controller(params);
|
|
|
|
tz->governor_data = params;
|
|
|
|
return 0;
|
|
|
|
free_params:
|
|
kfree(params);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void power_allocator_unbind(struct thermal_zone_device *tz)
|
|
{
|
|
struct power_allocator_params *params = tz->governor_data;
|
|
|
|
dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id);
|
|
|
|
if (params->allocated_tzp) {
|
|
kfree(tz->tzp);
|
|
tz->tzp = NULL;
|
|
}
|
|
|
|
kfree(tz->governor_data);
|
|
tz->governor_data = NULL;
|
|
}
|
|
|
|
static int power_allocator_throttle(struct thermal_zone_device *tz, int trip)
|
|
{
|
|
int ret;
|
|
int switch_on_temp, control_temp;
|
|
struct power_allocator_params *params = tz->governor_data;
|
|
bool update;
|
|
|
|
/*
|
|
* We get called for every trip point but we only need to do
|
|
* our calculations once
|
|
*/
|
|
if (trip != params->trip_max_desired_temperature)
|
|
return 0;
|
|
|
|
ret = tz->ops->get_trip_temp(tz, params->trip_switch_on,
|
|
&switch_on_temp);
|
|
if (!ret && (tz->temperature < switch_on_temp)) {
|
|
update = (tz->last_temperature >= switch_on_temp);
|
|
tz->passive = 0;
|
|
reset_pid_controller(params);
|
|
allow_maximum_power(tz, update);
|
|
return 0;
|
|
}
|
|
|
|
tz->passive = 1;
|
|
|
|
ret = tz->ops->get_trip_temp(tz, params->trip_max_desired_temperature,
|
|
&control_temp);
|
|
if (ret) {
|
|
dev_warn(&tz->device,
|
|
"Failed to get the maximum desired temperature: %d\n",
|
|
ret);
|
|
return ret;
|
|
}
|
|
|
|
return allocate_power(tz, control_temp);
|
|
}
|
|
|
|
static struct thermal_governor thermal_gov_power_allocator = {
|
|
.name = "power_allocator",
|
|
.bind_to_tz = power_allocator_bind,
|
|
.unbind_from_tz = power_allocator_unbind,
|
|
.throttle = power_allocator_throttle,
|
|
};
|
|
THERMAL_GOVERNOR_DECLARE(thermal_gov_power_allocator);
|