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linux/drivers/thermal/cpu_cooling.c

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/*
* linux/drivers/thermal/cpu_cooling.c
*
* Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com)
* Copyright (C) 2012 Amit Daniel <amit.kachhap@linaro.org>
*
* Copyright (C) 2014 Viresh Kumar <viresh.kumar@linaro.org>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/module.h>
#include <linux/thermal.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/cpu_cooling.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 power_table - frequency to power conversion
* @frequency: frequency in KHz
* @power: power in mW
*
* This structure is built when the cooling device registers and helps
* in translating frequency to power and viceversa.
*/
struct power_table {
u32 frequency;
u32 power;
};
/**
* struct cpufreq_cooling_device - data for cooling device with cpufreq
* @id: unique integer value corresponding to each cpufreq_cooling_device
* registered.
* @cool_dev: thermal_cooling_device pointer to keep track of the
* registered cooling device.
* @cpufreq_state: integer value representing the current state of cpufreq
* cooling devices.
* @clipped_freq: integer value representing the absolute value of the clipped
* frequency.
* @max_level: maximum cooling level. One less than total number of valid
* cpufreq frequencies.
* @allowed_cpus: all the cpus involved for this cpufreq_cooling_device.
* @node: list_head to link all cpufreq_cooling_device together.
* @last_load: load measured by the latest call to cpufreq_get_actual_power()
* @time_in_idle: previous reading of the absolute time that this cpu was idle
* @time_in_idle_timestamp: wall time of the last invocation of
* get_cpu_idle_time_us()
* @dyn_power_table: array of struct power_table for frequency to power
* conversion, sorted in ascending order.
* @dyn_power_table_entries: number of entries in the @dyn_power_table array
* @cpu_dev: the first cpu_device from @allowed_cpus that has OPPs registered
* @plat_get_static_power: callback to calculate the static power
*
* This structure is required for keeping information of each registered
* cpufreq_cooling_device.
*/
struct cpufreq_cooling_device {
int id;
struct thermal_cooling_device *cool_dev;
unsigned int cpufreq_state;
unsigned int clipped_freq;
unsigned int max_level;
unsigned int *freq_table; /* In descending order */
struct cpumask allowed_cpus;
struct list_head node;
u32 last_load;
u64 *time_in_idle;
u64 *time_in_idle_timestamp;
struct power_table *dyn_power_table;
int dyn_power_table_entries;
struct device *cpu_dev;
get_static_t plat_get_static_power;
};
static DEFINE_IDR(cpufreq_idr);
static DEFINE_MUTEX(cooling_cpufreq_lock);
static unsigned int cpufreq_dev_count;
static DEFINE_MUTEX(cooling_list_lock);
static LIST_HEAD(cpufreq_dev_list);
/**
* get_idr - function to get a unique id.
* @idr: struct idr * handle used to create a id.
* @id: int * value generated by this function.
*
* This function will populate @id with an unique
* id, using the idr API.
*
* Return: 0 on success, an error code on failure.
*/
static int get_idr(struct idr *idr, int *id)
{
int ret;
mutex_lock(&cooling_cpufreq_lock);
ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL);
mutex_unlock(&cooling_cpufreq_lock);
if (unlikely(ret < 0))
return ret;
*id = ret;
return 0;
}
/**
* release_idr - function to free the unique id.
* @idr: struct idr * handle used for creating the id.
* @id: int value representing the unique id.
*/
static void release_idr(struct idr *idr, int id)
{
mutex_lock(&cooling_cpufreq_lock);
idr_remove(idr, id);
mutex_unlock(&cooling_cpufreq_lock);
}
/* Below code defines functions to be used for cpufreq as cooling device */
/**
* get_level: Find the level for a particular frequency
* @cpufreq_dev: cpufreq_dev for which the property is required
* @freq: Frequency
*
* Return: level on success, THERMAL_CSTATE_INVALID on error.
*/
static unsigned long get_level(struct cpufreq_cooling_device *cpufreq_dev,
unsigned int freq)
{
unsigned long level;
for (level = 0; level <= cpufreq_dev->max_level; level++) {
if (freq == cpufreq_dev->freq_table[level])
return level;
if (freq > cpufreq_dev->freq_table[level])
break;
}
return THERMAL_CSTATE_INVALID;
}
/**
* cpufreq_cooling_get_level - for a given cpu, return the cooling level.
* @cpu: cpu for which the level is required
* @freq: the frequency of interest
*
* This function will match the cooling level corresponding to the
* requested @freq and return it.
*
* Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
* otherwise.
*/
unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
{
struct cpufreq_cooling_device *cpufreq_dev;
mutex_lock(&cooling_list_lock);
list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {
if (cpumask_test_cpu(cpu, &cpufreq_dev->allowed_cpus)) {
mutex_unlock(&cooling_list_lock);
return get_level(cpufreq_dev, freq);
}
}
mutex_unlock(&cooling_list_lock);
pr_err("%s: cpu:%d not part of any cooling device\n", __func__, cpu);
return THERMAL_CSTATE_INVALID;
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);
/**
* cpufreq_thermal_notifier - notifier callback for cpufreq policy change.
* @nb: struct notifier_block * with callback info.
* @event: value showing cpufreq event for which this function invoked.
* @data: callback-specific data
*
* Callback to hijack the notification on cpufreq policy transition.
* Every time there is a change in policy, we will intercept and
* update the cpufreq policy with thermal constraints.
*
* Return: 0 (success)
*/
static int cpufreq_thermal_notifier(struct notifier_block *nb,
unsigned long event, void *data)
{
struct cpufreq_policy *policy = data;
unsigned long clipped_freq;
struct cpufreq_cooling_device *cpufreq_dev;
if (event != CPUFREQ_ADJUST)
return NOTIFY_DONE;
mutex_lock(&cooling_list_lock);
list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {
if (!cpumask_test_cpu(policy->cpu, &cpufreq_dev->allowed_cpus))
continue;
/*
* policy->max is the maximum allowed frequency defined by user
* and clipped_freq is the maximum that thermal constraints
* allow.
*
* If clipped_freq is lower than policy->max, then we need to
* readjust policy->max.
*
* But, if clipped_freq is greater than policy->max, we don't
* need to do anything.
*/
clipped_freq = cpufreq_dev->clipped_freq;
if (policy->max > clipped_freq)
cpufreq_verify_within_limits(policy, 0, clipped_freq);
break;
}
mutex_unlock(&cooling_list_lock);
return NOTIFY_OK;
}
/**
* build_dyn_power_table() - create a dynamic power to frequency table
* @cpufreq_device: the cpufreq cooling device in which to store the table
* @capacitance: dynamic power coefficient for these cpus
*
* Build a dynamic power to frequency table for this cpu and store it
* in @cpufreq_device. This table will be used in cpu_power_to_freq() and
* cpu_freq_to_power() to convert between power and frequency
* efficiently. Power is stored in mW, frequency in KHz. The
* resulting table is in ascending order.
*
* Return: 0 on success, -EINVAL if there are no OPPs for any CPUs,
* -ENOMEM if we run out of memory or -EAGAIN if an OPP was
* added/enabled while the function was executing.
*/
static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
u32 capacitance)
{
struct power_table *power_table;
struct dev_pm_opp *opp;
struct device *dev = NULL;
int num_opps = 0, cpu, i, ret = 0;
unsigned long freq;
for_each_cpu(cpu, &cpufreq_device->allowed_cpus) {
dev = get_cpu_device(cpu);
if (!dev) {
dev_warn(&cpufreq_device->cool_dev->device,
"No cpu device for cpu %d\n", cpu);
continue;
}
num_opps = dev_pm_opp_get_opp_count(dev);
if (num_opps > 0)
break;
else if (num_opps < 0)
return num_opps;
}
if (num_opps == 0)
return -EINVAL;
power_table = kcalloc(num_opps, sizeof(*power_table), GFP_KERNEL);
if (!power_table)
return -ENOMEM;
rcu_read_lock();
for (freq = 0, i = 0;
opp = dev_pm_opp_find_freq_ceil(dev, &freq), !IS_ERR(opp);
freq++, i++) {
u32 freq_mhz, voltage_mv;
u64 power;
if (i >= num_opps) {
rcu_read_unlock();
ret = -EAGAIN;
goto free_power_table;
}
freq_mhz = freq / 1000000;
voltage_mv = dev_pm_opp_get_voltage(opp) / 1000;
/*
* Do the multiplication with MHz and millivolt so as
* to not overflow.
*/
power = (u64)capacitance * freq_mhz * voltage_mv * voltage_mv;
do_div(power, 1000000000);
/* frequency is stored in power_table in KHz */
power_table[i].frequency = freq / 1000;
/* power is stored in mW */
power_table[i].power = power;
}
rcu_read_unlock();
if (i != num_opps) {
ret = PTR_ERR(opp);
goto free_power_table;
}
cpufreq_device->cpu_dev = dev;
cpufreq_device->dyn_power_table = power_table;
cpufreq_device->dyn_power_table_entries = i;
return 0;
free_power_table:
kfree(power_table);
return ret;
}
static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_device,
u32 freq)
{
int i;
struct power_table *pt = cpufreq_device->dyn_power_table;
for (i = 1; i < cpufreq_device->dyn_power_table_entries; i++)
if (freq < pt[i].frequency)
break;
return pt[i - 1].power;
}
static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_device,
u32 power)
{
int i;
struct power_table *pt = cpufreq_device->dyn_power_table;
for (i = 1; i < cpufreq_device->dyn_power_table_entries; i++)
if (power < pt[i].power)
break;
return pt[i - 1].frequency;
}
/**
* get_load() - get load for a cpu since last updated
* @cpufreq_device: &struct cpufreq_cooling_device for this cpu
* @cpu: cpu number
* @cpu_idx: index of the cpu in cpufreq_device->allowed_cpus
*
* Return: The average load of cpu @cpu in percentage since this
* function was last called.
*/
static u32 get_load(struct cpufreq_cooling_device *cpufreq_device, int cpu,
int cpu_idx)
{
u32 load;
u64 now, now_idle, delta_time, delta_idle;
now_idle = get_cpu_idle_time(cpu, &now, 0);
delta_idle = now_idle - cpufreq_device->time_in_idle[cpu_idx];
delta_time = now - cpufreq_device->time_in_idle_timestamp[cpu_idx];
if (delta_time <= delta_idle)
load = 0;
else
load = div64_u64(100 * (delta_time - delta_idle), delta_time);
cpufreq_device->time_in_idle[cpu_idx] = now_idle;
cpufreq_device->time_in_idle_timestamp[cpu_idx] = now;
return load;
}
/**
* get_static_power() - calculate the static power consumed by the cpus
* @cpufreq_device: struct &cpufreq_cooling_device for this cpu cdev
* @tz: thermal zone device in which we're operating
* @freq: frequency in KHz
* @power: pointer in which to store the calculated static power
*
* Calculate the static power consumed by the cpus described by
* @cpu_actor running at frequency @freq. This function relies on a
* platform specific function that should have been provided when the
* actor was registered. If it wasn't, the static power is assumed to
* be negligible. The calculated static power is stored in @power.
*
* Return: 0 on success, -E* on failure.
*/
static int get_static_power(struct cpufreq_cooling_device *cpufreq_device,
struct thermal_zone_device *tz, unsigned long freq,
u32 *power)
{
struct dev_pm_opp *opp;
unsigned long voltage;
struct cpumask *cpumask = &cpufreq_device->allowed_cpus;
unsigned long freq_hz = freq * 1000;
if (!cpufreq_device->plat_get_static_power ||
!cpufreq_device->cpu_dev) {
*power = 0;
return 0;
}
rcu_read_lock();
opp = dev_pm_opp_find_freq_exact(cpufreq_device->cpu_dev, freq_hz,
true);
voltage = dev_pm_opp_get_voltage(opp);
rcu_read_unlock();
if (voltage == 0) {
dev_warn_ratelimited(cpufreq_device->cpu_dev,
"Failed to get voltage for frequency %lu: %ld\n",
freq_hz, IS_ERR(opp) ? PTR_ERR(opp) : 0);
return -EINVAL;
}
return cpufreq_device->plat_get_static_power(cpumask, tz->passive_delay,
voltage, power);
}
/**
* get_dynamic_power() - calculate the dynamic power
* @cpufreq_device: &cpufreq_cooling_device for this cdev
* @freq: current frequency
*
* Return: the dynamic power consumed by the cpus described by
* @cpufreq_device.
*/
static u32 get_dynamic_power(struct cpufreq_cooling_device *cpufreq_device,
unsigned long freq)
{
u32 raw_cpu_power;
raw_cpu_power = cpu_freq_to_power(cpufreq_device, freq);
return (raw_cpu_power * cpufreq_device->last_load) / 100;
}
/* 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_device = cdev->devdata;
*state = cpufreq_device->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_device = cdev->devdata;
*state = cpufreq_device->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_device = cdev->devdata;
unsigned int cpu = cpumask_any(&cpufreq_device->allowed_cpus);
unsigned int clip_freq;
/* Request state should be less than max_level */
if (WARN_ON(state > cpufreq_device->max_level))
return -EINVAL;
/* Check if the old cooling action is same as new cooling action */
if (cpufreq_device->cpufreq_state == state)
return 0;
clip_freq = cpufreq_device->freq_table[state];
cpufreq_device->cpufreq_state = state;
cpufreq_device->clipped_freq = clip_freq;
cpufreq_update_policy(cpu);
return 0;
}
/**
* 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, ret;
u32 static_power, dynamic_power, total_load = 0;
struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
u32 *load_cpu = NULL;
cpu = cpumask_any_and(&cpufreq_device->allowed_cpus, cpu_online_mask);
/*
* All the CPUs are offline, thus the requested power by
* the cdev is 0
*/
if (cpu >= nr_cpu_ids) {
*power = 0;
return 0;
}
freq = cpufreq_quick_get(cpu);
if (trace_thermal_power_cpu_get_power_enabled()) {
u32 ncpus = cpumask_weight(&cpufreq_device->allowed_cpus);
load_cpu = kcalloc(ncpus, sizeof(*load_cpu), GFP_KERNEL);
}
for_each_cpu(cpu, &cpufreq_device->allowed_cpus) {
u32 load;
if (cpu_online(cpu))
load = get_load(cpufreq_device, cpu, i);
else
load = 0;
total_load += load;
if (trace_thermal_power_cpu_limit_enabled() && load_cpu)
load_cpu[i] = load;
i++;
}
cpufreq_device->last_load = total_load;
dynamic_power = get_dynamic_power(cpufreq_device, freq);
ret = get_static_power(cpufreq_device, tz, freq, &static_power);
if (ret) {
kfree(load_cpu);
return ret;
}
if (load_cpu) {
trace_thermal_power_cpu_get_power(
&cpufreq_device->allowed_cpus,
freq, load_cpu, i, dynamic_power, static_power);
kfree(load_cpu);
}
*power = static_power + dynamic_power;
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;
cpumask_t cpumask;
u32 static_power, dynamic_power;
int ret;
struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
cpumask_and(&cpumask, &cpufreq_device->allowed_cpus, cpu_online_mask);
num_cpus = cpumask_weight(&cpumask);
/* None of our cpus are online, so no power */
if (num_cpus == 0) {
*power = 0;
return 0;
}
freq = cpufreq_device->freq_table[state];
if (!freq)
return -EINVAL;
dynamic_power = cpu_freq_to_power(cpufreq_device, freq) * num_cpus;
ret = get_static_power(cpufreq_device, tz, freq, &static_power);
if (ret)
return ret;
*power = static_power + dynamic_power;
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 cpu, cur_freq, target_freq;
int ret;
s32 dyn_power;
u32 last_load, normalised_power, static_power;
struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
cpu = cpumask_any_and(&cpufreq_device->allowed_cpus, cpu_online_mask);
/* None of our cpus are online */
if (cpu >= nr_cpu_ids)
return -ENODEV;
cur_freq = cpufreq_quick_get(cpu);
ret = get_static_power(cpufreq_device, tz, cur_freq, &static_power);
if (ret)
return ret;
dyn_power = power - static_power;
dyn_power = dyn_power > 0 ? dyn_power : 0;
last_load = cpufreq_device->last_load ?: 1;
normalised_power = (dyn_power * 100) / last_load;
target_freq = cpu_power_to_freq(cpufreq_device, normalised_power);
*state = cpufreq_cooling_get_level(cpu, target_freq);
if (*state == THERMAL_CSTATE_INVALID) {
dev_warn_ratelimited(&cdev->device,
"Failed to convert %dKHz for cpu %d into a cdev state\n",
target_freq, cpu);
return -EINVAL;
}
trace_thermal_power_cpu_limit(&cpufreq_device->allowed_cpus,
target_freq, *state, power);
return 0;
}
/* 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,
};
/* Notifier for cpufreq policy change */
static struct notifier_block thermal_cpufreq_notifier_block = {
.notifier_call = cpufreq_thermal_notifier,
};
static unsigned int find_next_max(struct cpufreq_frequency_table *table,
unsigned int prev_max)
{
struct cpufreq_frequency_table *pos;
unsigned int max = 0;
cpufreq_for_each_valid_entry(pos, table) {
if (pos->frequency > max && pos->frequency < prev_max)
max = pos->frequency;
}
return max;
}
/**
* __cpufreq_cooling_register - helper function to create cpufreq cooling device
* @np: a valid struct device_node to the cooling device device tree node
* @clip_cpus: cpumask of cpus where the frequency constraints will happen.
* Normally this should be same as cpufreq policy->related_cpus.
* @capacitance: dynamic power coefficient for these cpus
* @plat_static_func: function to calculate the static power consumed by these
* cpus (optional)
*
* 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,
const struct cpumask *clip_cpus, u32 capacitance,
get_static_t plat_static_func)
{
struct thermal_cooling_device *cool_dev;
struct cpufreq_cooling_device *cpufreq_dev;
char dev_name[THERMAL_NAME_LENGTH];
struct cpufreq_frequency_table *pos, *table;
unsigned int freq, i, num_cpus;
int ret;
table = cpufreq_frequency_get_table(cpumask_first(clip_cpus));
if (!table) {
pr_debug("%s: CPUFreq table not found\n", __func__);
return ERR_PTR(-EPROBE_DEFER);
}
cpufreq_dev = kzalloc(sizeof(*cpufreq_dev), GFP_KERNEL);
if (!cpufreq_dev)
return ERR_PTR(-ENOMEM);
num_cpus = cpumask_weight(clip_cpus);
cpufreq_dev->time_in_idle = kcalloc(num_cpus,
sizeof(*cpufreq_dev->time_in_idle),
GFP_KERNEL);
if (!cpufreq_dev->time_in_idle) {
cool_dev = ERR_PTR(-ENOMEM);
goto free_cdev;
}
cpufreq_dev->time_in_idle_timestamp =
kcalloc(num_cpus, sizeof(*cpufreq_dev->time_in_idle_timestamp),
GFP_KERNEL);
if (!cpufreq_dev->time_in_idle_timestamp) {
cool_dev = ERR_PTR(-ENOMEM);
goto free_time_in_idle;
}
/* Find max levels */
cpufreq_for_each_valid_entry(pos, table)
cpufreq_dev->max_level++;
cpufreq_dev->freq_table = kmalloc(sizeof(*cpufreq_dev->freq_table) *
cpufreq_dev->max_level, GFP_KERNEL);
if (!cpufreq_dev->freq_table) {
cool_dev = ERR_PTR(-ENOMEM);
goto free_time_in_idle_timestamp;
}
/* max_level is an index, not a counter */
cpufreq_dev->max_level--;
cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus);
if (capacitance) {
cpufreq_cooling_ops.get_requested_power =
cpufreq_get_requested_power;
cpufreq_cooling_ops.state2power = cpufreq_state2power;
cpufreq_cooling_ops.power2state = cpufreq_power2state;
cpufreq_dev->plat_get_static_power = plat_static_func;
ret = build_dyn_power_table(cpufreq_dev, capacitance);
if (ret) {
cool_dev = ERR_PTR(ret);
goto free_table;
}
}
ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
if (ret) {
cool_dev = ERR_PTR(ret);
goto free_power_table;
}
/* Fill freq-table in descending order of frequencies */
for (i = 0, freq = -1; i <= cpufreq_dev->max_level; i++) {
freq = find_next_max(table, freq);
cpufreq_dev->freq_table[i] = freq;
/* Warn for duplicate entries */
if (!freq)
pr_warn("%s: table has duplicate entries\n", __func__);
else
pr_debug("%s: freq:%u KHz\n", __func__, freq);
}
snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
cpufreq_dev->id);
cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev,
&cpufreq_cooling_ops);
if (IS_ERR(cool_dev))
goto remove_idr;
cpufreq_dev->clipped_freq = cpufreq_dev->freq_table[0];
cpufreq_dev->cool_dev = cool_dev;
mutex_lock(&cooling_cpufreq_lock);
mutex_lock(&cooling_list_lock);
list_add(&cpufreq_dev->node, &cpufreq_dev_list);
mutex_unlock(&cooling_list_lock);
/* Register the notifier for first cpufreq cooling device */
if (!cpufreq_dev_count++)
cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
CPUFREQ_POLICY_NOTIFIER);
mutex_unlock(&cooling_cpufreq_lock);
return cool_dev;
remove_idr:
release_idr(&cpufreq_idr, cpufreq_dev->id);
free_power_table:
kfree(cpufreq_dev->dyn_power_table);
free_table:
kfree(cpufreq_dev->freq_table);
free_time_in_idle_timestamp:
kfree(cpufreq_dev->time_in_idle_timestamp);
free_time_in_idle:
kfree(cpufreq_dev->time_in_idle);
free_cdev:
kfree(cpufreq_dev);
return cool_dev;
}
/**
* cpufreq_cooling_register - function to create cpufreq cooling device.
* @clip_cpus: cpumask of cpus where the frequency constraints will happen.
*
* 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(const struct cpumask *clip_cpus)
{
return __cpufreq_cooling_register(NULL, clip_cpus, 0, NULL);
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
/**
* of_cpufreq_cooling_register - function to create cpufreq cooling device.
* @np: a valid struct device_node to the cooling device device tree node
* @clip_cpus: cpumask of cpus where the frequency constraints will happen.
*
* 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.
*
* Return: a valid struct thermal_cooling_device pointer on success,
* on failure, it returns a corresponding ERR_PTR().
*/
struct thermal_cooling_device *
of_cpufreq_cooling_register(struct device_node *np,
const struct cpumask *clip_cpus)
{
if (!np)
return ERR_PTR(-EINVAL);
return __cpufreq_cooling_register(np, clip_cpus, 0, NULL);
}
EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);
/**
* cpufreq_power_cooling_register() - create cpufreq cooling device with power extensions
* @clip_cpus: cpumask of cpus where the frequency constraints will happen
* @capacitance: dynamic power coefficient for these cpus
* @plat_static_func: function to calculate the static power consumed by these
* cpus (optional)
*
* 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 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.
*
* An optional @plat_static_func may be provided to calculate the
* static power consumed by these cpus. If the platform's static
* power consumption is unknown or negligible, make it NULL.
*
* Return: a valid struct thermal_cooling_device pointer on success,
* on failure, it returns a corresponding ERR_PTR().
*/
struct thermal_cooling_device *
cpufreq_power_cooling_register(const struct cpumask *clip_cpus, u32 capacitance,
get_static_t plat_static_func)
{
return __cpufreq_cooling_register(NULL, clip_cpus, capacitance,
plat_static_func);
}
EXPORT_SYMBOL(cpufreq_power_cooling_register);
/**
* of_cpufreq_power_cooling_register() - create cpufreq cooling device with power extensions
* @np: a valid struct device_node to the cooling device device tree node
* @clip_cpus: cpumask of cpus where the frequency constraints will happen
* @capacitance: dynamic power coefficient for these cpus
* @plat_static_func: function to calculate the static power consumed by these
* cpus (optional)
*
* 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.
*
* An optional @plat_static_func may be provided to calculate the
* static power consumed by these cpus. If the platform's static
* power consumption is unknown or negligible, make it NULL.
*
* Return: a valid struct thermal_cooling_device pointer on success,
* on failure, it returns a corresponding ERR_PTR().
*/
struct thermal_cooling_device *
of_cpufreq_power_cooling_register(struct device_node *np,
const struct cpumask *clip_cpus,
u32 capacitance,
get_static_t plat_static_func)
{
if (!np)
return ERR_PTR(-EINVAL);
return __cpufreq_cooling_register(np, clip_cpus, capacitance,
plat_static_func);
}
EXPORT_SYMBOL(of_cpufreq_power_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_dev;
if (!cdev)
return;
cpufreq_dev = cdev->devdata;
/* Unregister the notifier for the last cpufreq cooling device */
mutex_lock(&cooling_cpufreq_lock);
if (!--cpufreq_dev_count)
cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
CPUFREQ_POLICY_NOTIFIER);
mutex_lock(&cooling_list_lock);
list_del(&cpufreq_dev->node);
mutex_unlock(&cooling_list_lock);
mutex_unlock(&cooling_cpufreq_lock);
thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
release_idr(&cpufreq_idr, cpufreq_dev->id);
kfree(cpufreq_dev->dyn_power_table);
kfree(cpufreq_dev->time_in_idle_timestamp);
kfree(cpufreq_dev->time_in_idle);
kfree(cpufreq_dev->freq_table);
kfree(cpufreq_dev);
}
EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);
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