thermal/drivers/cpu_cooling: Rename to cpufreq_cooling

As we introduced the idle injection cooling device called
cpuidle_cooling, let's be consistent and rename the cpu_cooling to
cpufreq_cooling as this one mitigates with OPPs changes.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Link: https://lore.kernel.org/r/20191219225317.17158-3-daniel.lezcano@linaro.org

1 files changed, 670 insertions, 0 deletions

diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
new file mode 100644
index 000000000000..fe83d7a210d4
--- /dev/null
+++ b/drivers/thermal/cpufreq_cooling.c
@@ -0,0 +1,670 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/drivers/thermal/cpufreq_cooling.c
+ *
+ *  Copyright (C) 2012	Samsung Electronics Co., Ltd(http://www.samsung.com)
+ *
+ *  Copyright (C) 2012-2018 Linaro Limited.
+ *
+ *  Authors:	Amit Daniel <amit.kachhap@linaro.org>
+ *		Viresh Kumar <viresh.kumar@linaro.org>
+ *
+ */
+#include <linux/module.h>
+#include <linux/thermal.h>
+#include <linux/cpufreq.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/pm_opp.h>
+#include <linux/pm_qos.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/cpu_cooling.h>
+#include <linux/energy_model.h>
+
+#include <trace/events/thermal.h>
+
+/*
+ * 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
+ * @qos_req: PM QoS contraint to apply
+ *
+ * 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("cpufreq_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("cpufreq_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);