// SPDX-License-Identifier: GPL-2.0 /* * linux/drivers/thermal/cpu_cooling.c * * Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) * * Copyright (C) 2012-2018 Linaro Limited. * * Authors: Amit Daniel * Viresh Kumar * */ #include #include #include #include #include #include #include #include #include #include #include #include /* * Cooling state <-> CPUFreq frequency * * Cooling states are translated to frequencies throughout this driver and this * is the relation between them. * * Highest cooling state corresponds to lowest possible frequency. * * i.e. * level 0 --> 1st Max Freq * level 1 --> 2nd Max Freq * ... */ /** * struct time_in_idle - Idle time stats * @time: previous reading of the absolute time that this cpu was idle * @timestamp: wall time of the last invocation of get_cpu_idle_time_us() */ struct time_in_idle { u64 time; u64 timestamp; }; /** * struct cpufreq_cooling_device - data for cooling device with cpufreq * @id: unique integer value corresponding to each cpufreq_cooling_device * registered. * @last_load: load measured by the latest call to cpufreq_get_requested_power() * @cpufreq_state: integer value representing the current state of cpufreq * cooling devices. * @max_level: maximum cooling level. One less than total number of valid * cpufreq frequencies. * @em: Reference on the Energy Model of the device * @cdev: thermal_cooling_device pointer to keep track of the * registered cooling device. * @policy: cpufreq policy. * @node: list_head to link all cpufreq_cooling_device together. * @idle_time: idle time stats * * This structure is required for keeping information of each registered * cpufreq_cooling_device. */ struct cpufreq_cooling_device { int id; u32 last_load; unsigned int cpufreq_state; unsigned int max_level; struct em_perf_domain *em; struct cpufreq_policy *policy; struct list_head node; struct time_in_idle *idle_time; struct freq_qos_request qos_req; }; static DEFINE_IDA(cpufreq_ida); static DEFINE_MUTEX(cooling_list_lock); static LIST_HEAD(cpufreq_cdev_list); #ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR /** * get_level: Find the level for a particular frequency * @cpufreq_cdev: cpufreq_cdev for which the property is required * @freq: Frequency * * Return: level corresponding to the frequency. */ static unsigned long get_level(struct cpufreq_cooling_device *cpufreq_cdev, unsigned int freq) { int i; for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { if (freq > cpufreq_cdev->em->table[i].frequency) break; } return cpufreq_cdev->max_level - i - 1; } static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_cdev, u32 freq) { int i; for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { if (freq > cpufreq_cdev->em->table[i].frequency) break; } return cpufreq_cdev->em->table[i + 1].power; } static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev, u32 power) { int i; for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { if (power > cpufreq_cdev->em->table[i].power) break; } return cpufreq_cdev->em->table[i + 1].frequency; } /** * get_load() - get load for a cpu since last updated * @cpufreq_cdev: &struct cpufreq_cooling_device for this cpu * @cpu: cpu number * @cpu_idx: index of the cpu in time_in_idle* * * Return: The average load of cpu @cpu in percentage since this * function was last called. */ static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu, int cpu_idx) { u32 load; u64 now, now_idle, delta_time, delta_idle; struct time_in_idle *idle_time = &cpufreq_cdev->idle_time[cpu_idx]; now_idle = get_cpu_idle_time(cpu, &now, 0); delta_idle = now_idle - idle_time->time; delta_time = now - idle_time->timestamp; if (delta_time <= delta_idle) load = 0; else load = div64_u64(100 * (delta_time - delta_idle), delta_time); idle_time->time = now_idle; idle_time->timestamp = now; return load; } /** * get_dynamic_power() - calculate the dynamic power * @cpufreq_cdev: &cpufreq_cooling_device for this cdev * @freq: current frequency * * Return: the dynamic power consumed by the cpus described by * @cpufreq_cdev. */ static u32 get_dynamic_power(struct cpufreq_cooling_device *cpufreq_cdev, unsigned long freq) { u32 raw_cpu_power; raw_cpu_power = cpu_freq_to_power(cpufreq_cdev, freq); return (raw_cpu_power * cpufreq_cdev->last_load) / 100; } /** * cpufreq_get_requested_power() - get the current power * @cdev: &thermal_cooling_device pointer * @tz: a valid thermal zone device pointer * @power: pointer in which to store the resulting power * * Calculate the current power consumption of the cpus in milliwatts * and store it in @power. This function should actually calculate * the requested power, but it's hard to get the frequency that * cpufreq would have assigned if there were no thermal limits. * Instead, we calculate the current power on the assumption that the * immediate future will look like the immediate past. * * We use the current frequency and the average load since this * function was last called. In reality, there could have been * multiple opps since this function was last called and that affects * the load calculation. While it's not perfectly accurate, this * simplification is good enough and works. REVISIT this, as more * complex code may be needed if experiments show that it's not * accurate enough. * * Return: 0 on success, -E* if getting the static power failed. */ static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev, struct thermal_zone_device *tz, u32 *power) { unsigned long freq; int i = 0, cpu; u32 total_load = 0; struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; struct cpufreq_policy *policy = cpufreq_cdev->policy; u32 *load_cpu = NULL; freq = cpufreq_quick_get(policy->cpu); if (trace_thermal_power_cpu_get_power_enabled()) { u32 ncpus = cpumask_weight(policy->related_cpus); load_cpu = kcalloc(ncpus, sizeof(*load_cpu), GFP_KERNEL); } for_each_cpu(cpu, policy->related_cpus) { u32 load; if (cpu_online(cpu)) load = get_load(cpufreq_cdev, cpu, i); else load = 0; total_load += load; if (load_cpu) load_cpu[i] = load; i++; } cpufreq_cdev->last_load = total_load; *power = get_dynamic_power(cpufreq_cdev, freq); if (load_cpu) { trace_thermal_power_cpu_get_power(policy->related_cpus, freq, load_cpu, i, *power); kfree(load_cpu); } return 0; } /** * cpufreq_state2power() - convert a cpu cdev state to power consumed * @cdev: &thermal_cooling_device pointer * @tz: a valid thermal zone device pointer * @state: cooling device state to be converted * @power: pointer in which to store the resulting power * * Convert cooling device state @state into power consumption in * milliwatts assuming 100% load. Store the calculated power in * @power. * * Return: 0 on success, -EINVAL if the cooling device state could not * be converted into a frequency or other -E* if there was an error * when calculating the static power. */ static int cpufreq_state2power(struct thermal_cooling_device *cdev, struct thermal_zone_device *tz, unsigned long state, u32 *power) { unsigned int freq, num_cpus, idx; struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; /* Request state should be less than max_level */ if (WARN_ON(state > cpufreq_cdev->max_level)) return -EINVAL; num_cpus = cpumask_weight(cpufreq_cdev->policy->cpus); idx = cpufreq_cdev->max_level - state; freq = cpufreq_cdev->em->table[idx].frequency; *power = cpu_freq_to_power(cpufreq_cdev, freq) * num_cpus; return 0; } /** * cpufreq_power2state() - convert power to a cooling device state * @cdev: &thermal_cooling_device pointer * @tz: a valid thermal zone device pointer * @power: power in milliwatts to be converted * @state: pointer in which to store the resulting state * * Calculate a cooling device state for the cpus described by @cdev * that would allow them to consume at most @power mW and store it in * @state. Note that this calculation depends on external factors * such as the cpu load or the current static power. Calling this * function with the same power as input can yield different cooling * device states depending on those external factors. * * Return: 0 on success, -ENODEV if no cpus are online or -EINVAL if * the calculated frequency could not be converted to a valid state. * The latter should not happen unless the frequencies available to * cpufreq have changed since the initialization of the cpu cooling * device. */ static int cpufreq_power2state(struct thermal_cooling_device *cdev, struct thermal_zone_device *tz, u32 power, unsigned long *state) { unsigned int target_freq; u32 last_load, normalised_power; struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; struct cpufreq_policy *policy = cpufreq_cdev->policy; last_load = cpufreq_cdev->last_load ?: 1; normalised_power = (power * 100) / last_load; target_freq = cpu_power_to_freq(cpufreq_cdev, normalised_power); *state = get_level(cpufreq_cdev, target_freq); trace_thermal_power_cpu_limit(policy->related_cpus, target_freq, *state, power); return 0; } static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev, struct em_perf_domain *em) { struct cpufreq_policy *policy; unsigned int nr_levels; if (!em) return false; policy = cpufreq_cdev->policy; if (!cpumask_equal(policy->related_cpus, to_cpumask(em->cpus))) { pr_err("The span of pd %*pbl is misaligned with cpufreq policy %*pbl\n", cpumask_pr_args(to_cpumask(em->cpus)), cpumask_pr_args(policy->related_cpus)); return false; } nr_levels = cpufreq_cdev->max_level + 1; if (em->nr_cap_states != nr_levels) { pr_err("The number of cap states in pd %*pbl (%u) doesn't match the number of cooling levels (%u)\n", cpumask_pr_args(to_cpumask(em->cpus)), em->nr_cap_states, nr_levels); return false; } return true; } #endif /* CONFIG_THERMAL_GOV_POWER_ALLOCATOR */ static unsigned int get_state_freq(struct cpufreq_cooling_device *cpufreq_cdev, unsigned long state) { struct cpufreq_policy *policy; unsigned long idx; #ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR /* Use the Energy Model table if available */ if (cpufreq_cdev->em) { idx = cpufreq_cdev->max_level - state; return cpufreq_cdev->em->table[idx].frequency; } #endif /* Otherwise, fallback on the CPUFreq table */ policy = cpufreq_cdev->policy; if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING) idx = cpufreq_cdev->max_level - state; else idx = state; return policy->freq_table[idx].frequency; } /* cpufreq cooling device callback functions are defined below */ /** * cpufreq_get_max_state - callback function to get the max cooling state. * @cdev: thermal cooling device pointer. * @state: fill this variable with the max cooling state. * * Callback for the thermal cooling device to return the cpufreq * max cooling state. * * Return: 0 on success, an error code otherwise. */ static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state) { struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; *state = cpufreq_cdev->max_level; return 0; } /** * cpufreq_get_cur_state - callback function to get the current cooling state. * @cdev: thermal cooling device pointer. * @state: fill this variable with the current cooling state. * * Callback for the thermal cooling device to return the cpufreq * current cooling state. * * Return: 0 on success, an error code otherwise. */ static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state) { struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; *state = cpufreq_cdev->cpufreq_state; return 0; } /** * cpufreq_set_cur_state - callback function to set the current cooling state. * @cdev: thermal cooling device pointer. * @state: set this variable to the current cooling state. * * Callback for the thermal cooling device to change the cpufreq * current cooling state. * * Return: 0 on success, an error code otherwise. */ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state) { struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; /* Request state should be less than max_level */ if (WARN_ON(state > cpufreq_cdev->max_level)) return -EINVAL; /* Check if the old cooling action is same as new cooling action */ if (cpufreq_cdev->cpufreq_state == state) return 0; cpufreq_cdev->cpufreq_state = state; return freq_qos_update_request(&cpufreq_cdev->qos_req, get_state_freq(cpufreq_cdev, state)); } /* Bind cpufreq callbacks to thermal cooling device ops */ static struct thermal_cooling_device_ops cpufreq_cooling_ops = { .get_max_state = cpufreq_get_max_state, .get_cur_state = cpufreq_get_cur_state, .set_cur_state = cpufreq_set_cur_state, }; /** * __cpufreq_cooling_register - helper function to create cpufreq cooling device * @np: a valid struct device_node to the cooling device device tree node * @policy: cpufreq policy * Normally this should be same as cpufreq policy->related_cpus. * @em: Energy Model of the cpufreq policy * * This interface function registers the cpufreq cooling device with the name * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq * cooling devices. It also gives the opportunity to link the cooling device * with a device tree node, in order to bind it via the thermal DT code. * * Return: a valid struct thermal_cooling_device pointer on success, * on failure, it returns a corresponding ERR_PTR(). */ static struct thermal_cooling_device * __cpufreq_cooling_register(struct device_node *np, struct cpufreq_policy *policy, struct em_perf_domain *em) { struct thermal_cooling_device *cdev; struct cpufreq_cooling_device *cpufreq_cdev; char dev_name[THERMAL_NAME_LENGTH]; unsigned int i, num_cpus; struct device *dev; int ret; struct thermal_cooling_device_ops *cooling_ops; dev = get_cpu_device(policy->cpu); if (unlikely(!dev)) { pr_warn("No cpu device for cpu %d\n", policy->cpu); return ERR_PTR(-ENODEV); } if (IS_ERR_OR_NULL(policy)) { pr_err("%s: cpufreq policy isn't valid: %p\n", __func__, policy); return ERR_PTR(-EINVAL); } i = cpufreq_table_count_valid_entries(policy); if (!i) { pr_debug("%s: CPUFreq table not found or has no valid entries\n", __func__); return ERR_PTR(-ENODEV); } cpufreq_cdev = kzalloc(sizeof(*cpufreq_cdev), GFP_KERNEL); if (!cpufreq_cdev) return ERR_PTR(-ENOMEM); cpufreq_cdev->policy = policy; num_cpus = cpumask_weight(policy->related_cpus); cpufreq_cdev->idle_time = kcalloc(num_cpus, sizeof(*cpufreq_cdev->idle_time), GFP_KERNEL); if (!cpufreq_cdev->idle_time) { cdev = ERR_PTR(-ENOMEM); goto free_cdev; } /* max_level is an index, not a counter */ cpufreq_cdev->max_level = i - 1; ret = ida_simple_get(&cpufreq_ida, 0, 0, GFP_KERNEL); if (ret < 0) { cdev = ERR_PTR(ret); goto free_idle_time; } cpufreq_cdev->id = ret; snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d", cpufreq_cdev->id); cooling_ops = &cpufreq_cooling_ops; #ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR if (em_is_sane(cpufreq_cdev, em)) { cpufreq_cdev->em = em; cooling_ops->get_requested_power = cpufreq_get_requested_power; cooling_ops->state2power = cpufreq_state2power; cooling_ops->power2state = cpufreq_power2state; } else #endif if (policy->freq_table_sorted == CPUFREQ_TABLE_UNSORTED) { pr_err("%s: unsorted frequency tables are not supported\n", __func__); cdev = ERR_PTR(-EINVAL); goto remove_ida; } ret = freq_qos_add_request(&policy->constraints, &cpufreq_cdev->qos_req, FREQ_QOS_MAX, get_state_freq(cpufreq_cdev, 0)); if (ret < 0) { pr_err("%s: Failed to add freq constraint (%d)\n", __func__, ret); cdev = ERR_PTR(ret); goto remove_ida; } cdev = thermal_of_cooling_device_register(np, dev_name, cpufreq_cdev, cooling_ops); if (IS_ERR(cdev)) goto remove_qos_req; mutex_lock(&cooling_list_lock); list_add(&cpufreq_cdev->node, &cpufreq_cdev_list); mutex_unlock(&cooling_list_lock); return cdev; remove_qos_req: freq_qos_remove_request(&cpufreq_cdev->qos_req); remove_ida: ida_simple_remove(&cpufreq_ida, cpufreq_cdev->id); free_idle_time: kfree(cpufreq_cdev->idle_time); free_cdev: kfree(cpufreq_cdev); return cdev; } /** * cpufreq_cooling_register - function to create cpufreq cooling device. * @policy: cpufreq policy * * This interface function registers the cpufreq cooling device with the name * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq * cooling devices. * * Return: a valid struct thermal_cooling_device pointer on success, * on failure, it returns a corresponding ERR_PTR(). */ struct thermal_cooling_device * cpufreq_cooling_register(struct cpufreq_policy *policy) { return __cpufreq_cooling_register(NULL, policy, NULL); } EXPORT_SYMBOL_GPL(cpufreq_cooling_register); /** * of_cpufreq_cooling_register - function to create cpufreq cooling device. * @policy: cpufreq policy * * This interface function registers the cpufreq cooling device with the name * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq * cooling devices. Using this API, the cpufreq cooling device will be * linked to the device tree node provided. * * Using this function, the cooling device will implement the power * extensions by using a simple cpu power model. The cpus must have * registered their OPPs using the OPP library. * * It also takes into account, if property present in policy CPU node, the * static power consumed by the cpu. * * Return: a valid struct thermal_cooling_device pointer on success, * and NULL on failure. */ struct thermal_cooling_device * of_cpufreq_cooling_register(struct cpufreq_policy *policy) { struct device_node *np = of_get_cpu_node(policy->cpu, NULL); struct thermal_cooling_device *cdev = NULL; if (!np) { pr_err("cpu_cooling: OF node not available for cpu%d\n", policy->cpu); return NULL; } if (of_find_property(np, "#cooling-cells", NULL)) { struct em_perf_domain *em = em_cpu_get(policy->cpu); cdev = __cpufreq_cooling_register(np, policy, em); if (IS_ERR(cdev)) { pr_err("cpu_cooling: cpu%d failed to register as cooling device: %ld\n", policy->cpu, PTR_ERR(cdev)); cdev = NULL; } } of_node_put(np); return cdev; } EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register); /** * cpufreq_cooling_unregister - function to remove cpufreq cooling device. * @cdev: thermal cooling device pointer. * * This interface function unregisters the "thermal-cpufreq-%x" cooling device. */ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) { struct cpufreq_cooling_device *cpufreq_cdev; if (!cdev) return; cpufreq_cdev = cdev->devdata; mutex_lock(&cooling_list_lock); list_del(&cpufreq_cdev->node); mutex_unlock(&cooling_list_lock); thermal_cooling_device_unregister(cdev); freq_qos_remove_request(&cpufreq_cdev->qos_req); ida_simple_remove(&cpufreq_ida, cpufreq_cdev->id); kfree(cpufreq_cdev->idle_time); kfree(cpufreq_cdev); } EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);