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Merge branch 'cpu_cooling-doc-comments-update' of .git into next

This commit is contained in:
Zhang Rui 2013-04-25 00:57:37 +08:00
parent eea2d4812d e44dec77be
commit 07273d25b8
3 changed files with 88 additions and 28 deletions
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5
drivers/thermal/Kconfig
View File

@ -72,10 +72,11 @@ config CPU_THERMAL
select CPU_FREQ_TABLE
help
This implements the generic cpu cooling mechanism through frequency
reduction, cpu hotplug and any other ways of reducing temperature. An
ACPI version of this already exists(drivers/acpi/processor_thermal.c).
reduction. An ACPI version of this already exists
(drivers/acpi/processor_thermal.c).
This will be useful for platforms using the generic thermal interface
and not the ACPI interface.
If you want this support, you should say Y here.
config THERMAL_EMULATION

107
drivers/thermal/cpu_cooling.c
View File

@ -20,10 +20,8 @@
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/thermal.h>
#include <linux/platform_device.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/slab.h>
@ -31,21 +29,19 @@
#include <linux/cpu_cooling.h>
/**
* struct cpufreq_cooling_device
* 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 the
* egistered cooling device.
* @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.
* @cpufreq_val: integer value representing the absolute value of the clipped
* frequency.
* @allowed_cpus: all the cpus involved for this cpufreq_cooling_device.
* @node: list_head to link all cpufreq_cooling_device together.
*
* This structure is required for keeping information of each
* cpufreq_cooling_device registered as a list whose head is represented by
* cooling_cpufreq_list. In order to prevent corruption of this list a
* cpufreq_cooling_device registered. In order to prevent corruption of this a
* mutex lock cooling_cpufreq_lock is used.
*/
struct cpufreq_cooling_device {
@ -54,9 +50,7 @@ struct cpufreq_cooling_device {
unsigned int cpufreq_state;
unsigned int cpufreq_val;
struct cpumask allowed_cpus;
struct list_head node;
};
static LIST_HEAD(cooling_cpufreq_list);
static DEFINE_IDR(cpufreq_idr);
static DEFINE_MUTEX(cooling_cpufreq_lock);
@ -99,8 +93,14 @@ static void release_idr(struct idr *idr, int id)
/* Below code defines functions to be used for cpufreq as cooling device */
/**
* is_cpufreq_valid - function to check if a cpu has frequency transition policy.
* is_cpufreq_valid - function to check frequency transitioning capability.
* @cpu: cpu for which check is needed.
*
* This function will check the current state of the system if
* it is capable of changing the frequency for a given @cpu.
*
* Return: 0 if the system is not currently capable of changing
* the frequency of given cpu. !0 in case the frequency is changeable.
*/
static int is_cpufreq_valid(int cpu)
{
@ -114,8 +114,14 @@ enum cpufreq_cooling_property {
GET_MAXL,
};
/*
* this is the common function to
/**
* get_property - fetch a property of interest for a give cpu.
* @cpu: cpu for which the property is required
* @input: query parameter
* @output: query return
* @property: type of query (frequency, level, max level)
*
* This is the common function to
* 1. get maximum cpu cooling states
* 2. translate frequency to cooling state
* 3. translate cooling state to frequency
@ -124,12 +130,14 @@ enum cpufreq_cooling_property {
* a) reduce duplicate code as most of the code can be shared.
* b) make sure the logic is consistent when translating between
* cooling states and frequencies.
*/
*
* Return: 0 on success, -EINVAL when invalid parameters are passed.
*/
static int get_property(unsigned int cpu, unsigned long input,
unsigned int* output, enum cpufreq_cooling_property property)
{
int i, j;
unsigned long max_level = 0, level;
unsigned long max_level = 0, level = 0;
unsigned int freq = CPUFREQ_ENTRY_INVALID;
int descend = -1;
struct cpufreq_frequency_table *table =
@ -196,6 +204,17 @@ static int get_property(unsigned int cpu, unsigned long input,
return -EINVAL;
}
/**
* cpufreq_cooling_get_level - for a give 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)
{
unsigned int val;
@ -204,14 +223,19 @@ unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
return THERMAL_CSTATE_INVALID;
return (unsigned long)val;
}
EXPORT_SYMBOL(cpufreq_cooling_get_level);
EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);
/**
* get_cpu_frequency - get the absolute value of frequency from level.
* @cpu: cpu for which frequency is fetched.
* @level: level of frequency, equals cooling state of cpu cooling device
* @level: cooling level
*
* This function matches cooling level with frequency. Based on a cooling level
* of frequency, equals cooling state of cpu cooling device, it will return
* the corresponding frequency.
* e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
*
* Return: 0 on error, the corresponding frequency otherwise.
*/
static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level)
{
@ -229,6 +253,12 @@ static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level)
* @cpufreq_device: cpufreq_cooling_device pointer containing frequency
* clipping data.
* @cooling_state: value of the cooling state.
*
* Function used to make sure the cpufreq layer is aware of current thermal
* limits. The limits are applied by updating the cpufreq policy.
*
* Return: 0 on success, an error code otherwise (-EINVAL in case wrong
* cooling state).
*/
static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device,
unsigned long cooling_state)
@ -265,6 +295,12 @@ static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device,
* @nb: struct notifier_block * with callback info.
* @event: value showing cpufreq event for which this function invoked.
* @data: callback-specific data
*
* Callback to highjack 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)
@ -296,6 +332,11 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb,
* 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)
@ -320,6 +361,11 @@ static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
* 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)
@ -334,6 +380,11 @@ static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
* 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)
@ -358,6 +409,13 @@ static struct notifier_block thermal_cpufreq_notifier_block = {
/**
* 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)
@ -396,7 +454,8 @@ struct thermal_cooling_device *cpufreq_cooling_register(
return ERR_PTR(-EINVAL);
}
sprintf(dev_name, "thermal-cpufreq-%d", cpufreq_dev->id);
snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
cpufreq_dev->id);
cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev,
&cpufreq_cooling_ops);
@ -418,11 +477,13 @@ struct thermal_cooling_device *cpufreq_cooling_register(
mutex_unlock(&cooling_cpufreq_lock);
return cool_dev;
}
EXPORT_SYMBOL(cpufreq_cooling_register);
EXPORT_SYMBOL_GPL(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)
{
@ -432,14 +493,14 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
cpufreq_dev_count--;
/* Unregister the notifier for the last cpufreq cooling device */
if (cpufreq_dev_count == 0) {
if (cpufreq_dev_count == 0)
cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
CPUFREQ_POLICY_NOTIFIER);
}
mutex_unlock(&cooling_cpufreq_lock);
thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
release_idr(&cpufreq_idr, cpufreq_dev->id);
kfree(cpufreq_dev);
}
EXPORT_SYMBOL(cpufreq_cooling_unregister);
EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);

4
include/linux/cpu_cooling.h
View File

@ -25,9 +25,7 @@
#define __CPU_COOLING_H__
#include <linux/thermal.h>
#define CPUFREQ_COOLING_START 0
#define CPUFREQ_COOLING_STOP 1
#include <linux/cpumask.h>
#ifdef CONFIG_CPU_THERMAL
/**