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1// SPDX-License-Identifier: GPL-2.02/*3 * linux/drivers/thermal/cpufreq_cooling.c4 *5 * Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com)6 *7 * Copyright (C) 2012-2018 Linaro Limited.8 *9 * Authors: Amit Daniel <amit.kachhap@linaro.org>10 * Viresh Kumar <viresh.kumar@linaro.org>11 *12 */13#include <linux/cpu.h>14#include <linux/cpufreq.h>15#include <linux/cpu_cooling.h>16#include <linux/device.h>17#include <linux/energy_model.h>18#include <linux/err.h>19#include <linux/export.h>20#include <linux/pm_opp.h>21#include <linux/pm_qos.h>22#include <linux/slab.h>23#include <linux/thermal.h>24#include <linux/units.h>25 26#include "thermal_trace.h"27 28/*29 * Cooling state <-> CPUFreq frequency30 *31 * Cooling states are translated to frequencies throughout this driver and this32 * is the relation between them.33 *34 * Highest cooling state corresponds to lowest possible frequency.35 *36 * i.e.37 * level 0 --> 1st Max Freq38 * level 1 --> 2nd Max Freq39 * ...40 */41 42/**43 * struct time_in_idle - Idle time stats44 * @time: previous reading of the absolute time that this cpu was idle45 * @timestamp: wall time of the last invocation of get_cpu_idle_time_us()46 */47struct time_in_idle {48 u64 time;49 u64 timestamp;50};51 52/**53 * struct cpufreq_cooling_device - data for cooling device with cpufreq54 * @last_load: load measured by the latest call to cpufreq_get_requested_power()55 * @cpufreq_state: integer value representing the current state of cpufreq56 * cooling devices.57 * @max_level: maximum cooling level. One less than total number of valid58 * cpufreq frequencies.59 * @em: Reference on the Energy Model of the device60 * @cdev: thermal_cooling_device pointer to keep track of the61 * registered cooling device.62 * @policy: cpufreq policy.63 * @cooling_ops: cpufreq callbacks to thermal cooling device ops64 * @idle_time: idle time stats65 * @qos_req: PM QoS contraint to apply66 *67 * This structure is required for keeping information of each registered68 * cpufreq_cooling_device.69 */70struct cpufreq_cooling_device {71 u32 last_load;72 unsigned int cpufreq_state;73 unsigned int max_level;74 struct em_perf_domain *em;75 struct cpufreq_policy *policy;76 struct thermal_cooling_device_ops cooling_ops;77#ifndef CONFIG_SMP78 struct time_in_idle *idle_time;79#endif80 struct freq_qos_request qos_req;81};82 83#ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR84/**85 * get_level: Find the level for a particular frequency86 * @cpufreq_cdev: cpufreq_cdev for which the property is required87 * @freq: Frequency88 *89 * Return: level corresponding to the frequency.90 */91static unsigned long get_level(struct cpufreq_cooling_device *cpufreq_cdev,92 unsigned int freq)93{94 struct em_perf_state *table;95 int i;96 97 rcu_read_lock();98 table = em_perf_state_from_pd(cpufreq_cdev->em);99 for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) {100 if (freq > table[i].frequency)101 break;102 }103 rcu_read_unlock();104 105 return cpufreq_cdev->max_level - i - 1;106}107 108static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_cdev,109 u32 freq)110{111 struct em_perf_state *table;112 unsigned long power_mw;113 int i;114 115 rcu_read_lock();116 table = em_perf_state_from_pd(cpufreq_cdev->em);117 for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) {118 if (freq > table[i].frequency)119 break;120 }121 122 power_mw = table[i + 1].power;123 power_mw /= MICROWATT_PER_MILLIWATT;124 rcu_read_unlock();125 126 return power_mw;127}128 129static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev,130 u32 power)131{132 struct em_perf_state *table;133 unsigned long em_power_mw;134 u32 freq;135 int i;136 137 rcu_read_lock();138 table = em_perf_state_from_pd(cpufreq_cdev->em);139 for (i = cpufreq_cdev->max_level; i > 0; i--) {140 /* Convert EM power to milli-Watts to make safe comparison */141 em_power_mw = table[i].power;142 em_power_mw /= MICROWATT_PER_MILLIWATT;143 if (power >= em_power_mw)144 break;145 }146 freq = table[i].frequency;147 rcu_read_unlock();148 149 return freq;150}151 152/**153 * get_load() - get load for a cpu154 * @cpufreq_cdev: struct cpufreq_cooling_device for the cpu155 * @cpu: cpu number156 * @cpu_idx: index of the cpu in time_in_idle array157 *158 * Return: The average load of cpu @cpu in percentage since this159 * function was last called.160 */161#ifdef CONFIG_SMP162static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu,163 int cpu_idx)164{165 unsigned long util = sched_cpu_util(cpu);166 167 return (util * 100) / arch_scale_cpu_capacity(cpu);168}169#else /* !CONFIG_SMP */170static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu,171 int cpu_idx)172{173 u32 load;174 u64 now, now_idle, delta_time, delta_idle;175 struct time_in_idle *idle_time = &cpufreq_cdev->idle_time[cpu_idx];176 177 now_idle = get_cpu_idle_time(cpu, &now, 0);178 delta_idle = now_idle - idle_time->time;179 delta_time = now - idle_time->timestamp;180 181 if (delta_time <= delta_idle)182 load = 0;183 else184 load = div64_u64(100 * (delta_time - delta_idle), delta_time);185 186 idle_time->time = now_idle;187 idle_time->timestamp = now;188 189 return load;190}191#endif /* CONFIG_SMP */192 193/**194 * get_dynamic_power() - calculate the dynamic power195 * @cpufreq_cdev: &cpufreq_cooling_device for this cdev196 * @freq: current frequency197 *198 * Return: the dynamic power consumed by the cpus described by199 * @cpufreq_cdev.200 */201static u32 get_dynamic_power(struct cpufreq_cooling_device *cpufreq_cdev,202 unsigned long freq)203{204 u32 raw_cpu_power;205 206 raw_cpu_power = cpu_freq_to_power(cpufreq_cdev, freq);207 return (raw_cpu_power * cpufreq_cdev->last_load) / 100;208}209 210/**211 * cpufreq_get_requested_power() - get the current power212 * @cdev: &thermal_cooling_device pointer213 * @power: pointer in which to store the resulting power214 *215 * Calculate the current power consumption of the cpus in milliwatts216 * and store it in @power. This function should actually calculate217 * the requested power, but it's hard to get the frequency that218 * cpufreq would have assigned if there were no thermal limits.219 * Instead, we calculate the current power on the assumption that the220 * immediate future will look like the immediate past.221 *222 * We use the current frequency and the average load since this223 * function was last called. In reality, there could have been224 * multiple opps since this function was last called and that affects225 * the load calculation. While it's not perfectly accurate, this226 * simplification is good enough and works. REVISIT this, as more227 * complex code may be needed if experiments show that it's not228 * accurate enough.229 *230 * Return: 0 on success, this function doesn't fail.231 */232static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev,233 u32 *power)234{235 unsigned long freq;236 int i = 0, cpu;237 u32 total_load = 0;238 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;239 struct cpufreq_policy *policy = cpufreq_cdev->policy;240 241 freq = cpufreq_quick_get(policy->cpu);242 243 for_each_cpu(cpu, policy->related_cpus) {244 u32 load;245 246 if (cpu_online(cpu))247 load = get_load(cpufreq_cdev, cpu, i);248 else249 load = 0;250 251 total_load += load;252 }253 254 cpufreq_cdev->last_load = total_load;255 256 *power = get_dynamic_power(cpufreq_cdev, freq);257 258 trace_thermal_power_cpu_get_power_simple(policy->cpu, *power);259 260 return 0;261}262 263/**264 * cpufreq_state2power() - convert a cpu cdev state to power consumed265 * @cdev: &thermal_cooling_device pointer266 * @state: cooling device state to be converted267 * @power: pointer in which to store the resulting power268 *269 * Convert cooling device state @state into power consumption in270 * milliwatts assuming 100% load. Store the calculated power in271 * @power.272 *273 * Return: 0 on success, -EINVAL if the cooling device state is bigger274 * than maximum allowed.275 */276static int cpufreq_state2power(struct thermal_cooling_device *cdev,277 unsigned long state, u32 *power)278{279 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;280 unsigned int freq, num_cpus, idx;281 struct em_perf_state *table;282 283 /* Request state should be less than max_level */284 if (state > cpufreq_cdev->max_level)285 return -EINVAL;286 287 num_cpus = cpumask_weight(cpufreq_cdev->policy->cpus);288 289 idx = cpufreq_cdev->max_level - state;290 291 rcu_read_lock();292 table = em_perf_state_from_pd(cpufreq_cdev->em);293 freq = table[idx].frequency;294 rcu_read_unlock();295 296 *power = cpu_freq_to_power(cpufreq_cdev, freq) * num_cpus;297 298 return 0;299}300 301/**302 * cpufreq_power2state() - convert power to a cooling device state303 * @cdev: &thermal_cooling_device pointer304 * @power: power in milliwatts to be converted305 * @state: pointer in which to store the resulting state306 *307 * Calculate a cooling device state for the cpus described by @cdev308 * that would allow them to consume at most @power mW and store it in309 * @state. Note that this calculation depends on external factors310 * such as the CPUs load. Calling this function with the same power311 * as input can yield different cooling device states depending on those312 * external factors.313 *314 * Return: 0 on success, this function doesn't fail.315 */316static int cpufreq_power2state(struct thermal_cooling_device *cdev,317 u32 power, unsigned long *state)318{319 unsigned int target_freq;320 u32 last_load, normalised_power;321 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;322 struct cpufreq_policy *policy = cpufreq_cdev->policy;323 324 last_load = cpufreq_cdev->last_load ?: 1;325 normalised_power = (power * 100) / last_load;326 target_freq = cpu_power_to_freq(cpufreq_cdev, normalised_power);327 328 *state = get_level(cpufreq_cdev, target_freq);329 trace_thermal_power_cpu_limit(policy->related_cpus, target_freq, *state,330 power);331 return 0;332}333 334static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev,335 struct em_perf_domain *em) {336 struct cpufreq_policy *policy;337 unsigned int nr_levels;338 339 if (!em || em_is_artificial(em))340 return false;341 342 policy = cpufreq_cdev->policy;343 if (!cpumask_equal(policy->related_cpus, em_span_cpus(em))) {344 pr_err("The span of pd %*pbl is misaligned with cpufreq policy %*pbl\n",345 cpumask_pr_args(em_span_cpus(em)),346 cpumask_pr_args(policy->related_cpus));347 return false;348 }349 350 nr_levels = cpufreq_cdev->max_level + 1;351 if (em_pd_nr_perf_states(em) != nr_levels) {352 pr_err("The number of performance states in pd %*pbl (%u) doesn't match the number of cooling levels (%u)\n",353 cpumask_pr_args(em_span_cpus(em)),354 em_pd_nr_perf_states(em), nr_levels);355 return false;356 }357 358 return true;359}360#endif /* CONFIG_THERMAL_GOV_POWER_ALLOCATOR */361 362#ifdef CONFIG_SMP363static inline int allocate_idle_time(struct cpufreq_cooling_device *cpufreq_cdev)364{365 return 0;366}367 368static inline void free_idle_time(struct cpufreq_cooling_device *cpufreq_cdev)369{370}371#else372static int allocate_idle_time(struct cpufreq_cooling_device *cpufreq_cdev)373{374 unsigned int num_cpus = cpumask_weight(cpufreq_cdev->policy->related_cpus);375 376 cpufreq_cdev->idle_time = kcalloc(num_cpus,377 sizeof(*cpufreq_cdev->idle_time),378 GFP_KERNEL);379 if (!cpufreq_cdev->idle_time)380 return -ENOMEM;381 382 return 0;383}384 385static void free_idle_time(struct cpufreq_cooling_device *cpufreq_cdev)386{387 kfree(cpufreq_cdev->idle_time);388 cpufreq_cdev->idle_time = NULL;389}390#endif /* CONFIG_SMP */391 392static unsigned int get_state_freq(struct cpufreq_cooling_device *cpufreq_cdev,393 unsigned long state)394{395 struct cpufreq_policy *policy;396 unsigned long idx;397 398#ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR399 /* Use the Energy Model table if available */400 if (cpufreq_cdev->em) {401 struct em_perf_state *table;402 unsigned int freq;403 404 idx = cpufreq_cdev->max_level - state;405 406 rcu_read_lock();407 table = em_perf_state_from_pd(cpufreq_cdev->em);408 freq = table[idx].frequency;409 rcu_read_unlock();410 411 return freq;412 }413#endif414 415 /* Otherwise, fallback on the CPUFreq table */416 policy = cpufreq_cdev->policy;417 if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING)418 idx = cpufreq_cdev->max_level - state;419 else420 idx = state;421 422 return policy->freq_table[idx].frequency;423}424 425/* cpufreq cooling device callback functions are defined below */426 427/**428 * cpufreq_get_max_state - callback function to get the max cooling state.429 * @cdev: thermal cooling device pointer.430 * @state: fill this variable with the max cooling state.431 *432 * Callback for the thermal cooling device to return the cpufreq433 * max cooling state.434 *435 * Return: 0 on success, this function doesn't fail.436 */437static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,438 unsigned long *state)439{440 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;441 442 *state = cpufreq_cdev->max_level;443 return 0;444}445 446/**447 * cpufreq_get_cur_state - callback function to get the current cooling state.448 * @cdev: thermal cooling device pointer.449 * @state: fill this variable with the current cooling state.450 *451 * Callback for the thermal cooling device to return the cpufreq452 * current cooling state.453 *454 * Return: 0 on success, this function doesn't fail.455 */456static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,457 unsigned long *state)458{459 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;460 461 *state = cpufreq_cdev->cpufreq_state;462 463 return 0;464}465 466/**467 * cpufreq_set_cur_state - callback function to set the current cooling state.468 * @cdev: thermal cooling device pointer.469 * @state: set this variable to the current cooling state.470 *471 * Callback for the thermal cooling device to change the cpufreq472 * current cooling state.473 *474 * Return: 0 on success, an error code otherwise.475 */476static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,477 unsigned long state)478{479 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;480 unsigned int frequency;481 int ret;482 483 /* Request state should be less than max_level */484 if (state > cpufreq_cdev->max_level)485 return -EINVAL;486 487 /* Check if the old cooling action is same as new cooling action */488 if (cpufreq_cdev->cpufreq_state == state)489 return 0;490 491 frequency = get_state_freq(cpufreq_cdev, state);492 493 ret = freq_qos_update_request(&cpufreq_cdev->qos_req, frequency);494 if (ret >= 0) {495 cpufreq_cdev->cpufreq_state = state;496 ret = 0;497 }498 499 return ret;500}501 502/**503 * __cpufreq_cooling_register - helper function to create cpufreq cooling device504 * @np: a valid struct device_node to the cooling device tree node505 * @policy: cpufreq policy506 * Normally this should be same as cpufreq policy->related_cpus.507 * @em: Energy Model of the cpufreq policy508 *509 * This interface function registers the cpufreq cooling device with the name510 * "cpufreq-%s". This API can support multiple instances of cpufreq511 * cooling devices. It also gives the opportunity to link the cooling device512 * with a device tree node, in order to bind it via the thermal DT code.513 *514 * Return: a valid struct thermal_cooling_device pointer on success,515 * on failure, it returns a corresponding ERR_PTR().516 */517static struct thermal_cooling_device *518__cpufreq_cooling_register(struct device_node *np,519 struct cpufreq_policy *policy,520 struct em_perf_domain *em)521{522 struct thermal_cooling_device *cdev;523 struct cpufreq_cooling_device *cpufreq_cdev;524 unsigned int i;525 struct device *dev;526 int ret;527 struct thermal_cooling_device_ops *cooling_ops;528 char *name;529 530 if (IS_ERR_OR_NULL(policy)) {531 pr_err("%s: cpufreq policy isn't valid: %p\n", __func__, policy);532 return ERR_PTR(-EINVAL);533 }534 535 dev = get_cpu_device(policy->cpu);536 if (unlikely(!dev)) {537 pr_warn("No cpu device for cpu %d\n", policy->cpu);538 return ERR_PTR(-ENODEV);539 }540 541 i = cpufreq_table_count_valid_entries(policy);542 if (!i) {543 pr_debug("%s: CPUFreq table not found or has no valid entries\n",544 __func__);545 return ERR_PTR(-ENODEV);546 }547 548 cpufreq_cdev = kzalloc(sizeof(*cpufreq_cdev), GFP_KERNEL);549 if (!cpufreq_cdev)550 return ERR_PTR(-ENOMEM);551 552 cpufreq_cdev->policy = policy;553 554 ret = allocate_idle_time(cpufreq_cdev);555 if (ret) {556 cdev = ERR_PTR(ret);557 goto free_cdev;558 }559 560 /* max_level is an index, not a counter */561 cpufreq_cdev->max_level = i - 1;562 563 cooling_ops = &cpufreq_cdev->cooling_ops;564 cooling_ops->get_max_state = cpufreq_get_max_state;565 cooling_ops->get_cur_state = cpufreq_get_cur_state;566 cooling_ops->set_cur_state = cpufreq_set_cur_state;567 568#ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR569 if (em_is_sane(cpufreq_cdev, em)) {570 cpufreq_cdev->em = em;571 cooling_ops->get_requested_power = cpufreq_get_requested_power;572 cooling_ops->state2power = cpufreq_state2power;573 cooling_ops->power2state = cpufreq_power2state;574 } else575#endif576 if (policy->freq_table_sorted == CPUFREQ_TABLE_UNSORTED) {577 pr_err("%s: unsorted frequency tables are not supported\n",578 __func__);579 cdev = ERR_PTR(-EINVAL);580 goto free_idle_time;581 }582 583 ret = freq_qos_add_request(&policy->constraints,584 &cpufreq_cdev->qos_req, FREQ_QOS_MAX,585 get_state_freq(cpufreq_cdev, 0));586 if (ret < 0) {587 pr_err("%s: Failed to add freq constraint (%d)\n", __func__,588 ret);589 cdev = ERR_PTR(ret);590 goto free_idle_time;591 }592 593 cdev = ERR_PTR(-ENOMEM);594 name = kasprintf(GFP_KERNEL, "cpufreq-%s", dev_name(dev));595 if (!name)596 goto remove_qos_req;597 598 cdev = thermal_of_cooling_device_register(np, name, cpufreq_cdev,599 cooling_ops);600 kfree(name);601 602 if (IS_ERR(cdev))603 goto remove_qos_req;604 605 return cdev;606 607remove_qos_req:608 freq_qos_remove_request(&cpufreq_cdev->qos_req);609free_idle_time:610 free_idle_time(cpufreq_cdev);611free_cdev:612 kfree(cpufreq_cdev);613 return cdev;614}615 616/**617 * cpufreq_cooling_register - function to create cpufreq cooling device.618 * @policy: cpufreq policy619 *620 * This interface function registers the cpufreq cooling device with the name621 * "cpufreq-%s". This API can support multiple instances of cpufreq cooling622 * devices.623 *624 * Return: a valid struct thermal_cooling_device pointer on success,625 * on failure, it returns a corresponding ERR_PTR().626 */627struct thermal_cooling_device *628cpufreq_cooling_register(struct cpufreq_policy *policy)629{630 return __cpufreq_cooling_register(NULL, policy, NULL);631}632EXPORT_SYMBOL_GPL(cpufreq_cooling_register);633 634/**635 * of_cpufreq_cooling_register - function to create cpufreq cooling device.636 * @policy: cpufreq policy637 *638 * This interface function registers the cpufreq cooling device with the name639 * "cpufreq-%s". This API can support multiple instances of cpufreq cooling640 * devices. Using this API, the cpufreq cooling device will be linked to the641 * device tree node provided.642 *643 * Using this function, the cooling device will implement the power644 * extensions by using the Energy Model (if present). The cpus must have645 * registered their OPPs using the OPP library.646 *647 * Return: a valid struct thermal_cooling_device pointer on success,648 * and NULL on failure.649 */650struct thermal_cooling_device *651of_cpufreq_cooling_register(struct cpufreq_policy *policy)652{653 struct device_node *np = of_get_cpu_node(policy->cpu, NULL);654 struct thermal_cooling_device *cdev = NULL;655 656 if (!np) {657 pr_err("cpufreq_cooling: OF node not available for cpu%d\n",658 policy->cpu);659 return NULL;660 }661 662 if (of_property_present(np, "#cooling-cells")) {663 struct em_perf_domain *em = em_cpu_get(policy->cpu);664 665 cdev = __cpufreq_cooling_register(np, policy, em);666 if (IS_ERR(cdev)) {667 pr_err("cpufreq_cooling: cpu%d failed to register as cooling device: %ld\n",668 policy->cpu, PTR_ERR(cdev));669 cdev = NULL;670 }671 }672 673 of_node_put(np);674 return cdev;675}676EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);677 678/**679 * cpufreq_cooling_unregister - function to remove cpufreq cooling device.680 * @cdev: thermal cooling device pointer.681 *682 * This interface function unregisters the "cpufreq-%x" cooling device.683 */684void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)685{686 struct cpufreq_cooling_device *cpufreq_cdev;687 688 if (!cdev)689 return;690 691 cpufreq_cdev = cdev->devdata;692 693 thermal_cooling_device_unregister(cdev);694 freq_qos_remove_request(&cpufreq_cdev->qos_req);695 free_idle_time(cpufreq_cdev);696 kfree(cpufreq_cdev);697}698EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);699