Commit ae606089 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Zhang Rui
Browse files

thermal: convert cpu_cooling to use an IDA 



thermal cpu cooling does not use the ability to look up pointers by ID,
so convert it from using an IDR to the more space-efficient IDA.

The cooling_cpufreq_lock was being used to protect cpufreq_dev_count as
well as the IDR.  Rather than keep the mutex to protect a single integer,
I expanded the scope of cooling_list_lock to also cover cpufreq_dev_count.
We could also convert cpufreq_dev_count into an atomic.

Signed-off-by: default avatarMatthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
parent 7a6639dc

drivers/thermal/cpu_cooling.c

+11 −52
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/thermal.h>

#include <linux/cpufreq.h>

#include <linux/err.h>

#include <linux/idr.h>

#include <linux/pm_opp.h>

#include <linux/slab.h>

#include <linux/cpu.h>
@@ -104,50 +105,13 @@ struct cpufreq_cooling_device { 
	struct device *cpu_dev;

	get_static_t plat_get_static_power;

};

static DEFINE_IDR(cpufreq_idr);

static DEFINE_MUTEX(cooling_cpufreq_lock);

static DEFINE_IDA(cpufreq_ida);



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 */



/**
@@ -874,11 +838,12 @@ __cpufreq_cooling_register(struct device_node *np, 
		cooling_ops = &cpufreq_cooling_ops;

	}



	ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);

	if (ret) {

	ret = ida_simple_get(&cpufreq_ida, 0, 0, GFP_KERNEL);

	if (ret < 0) {

		cool_dev = ERR_PTR(ret);

		goto free_power_table;

	}

	cpufreq_dev->id = ret;



	/* Fill freq-table in descending order of frequencies */

	for (i = 0, freq = -1; i <= cpufreq_dev->max_level; i++) {
@@ -898,27 +863,24 @@ __cpufreq_cooling_register(struct device_node *np, 
	cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev,

						      cooling_ops);

	if (IS_ERR(cool_dev))

		goto remove_idr;

		goto remove_ida;



	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);

	mutex_unlock(&cooling_list_lock);



	goto put_policy;



remove_idr:

	release_idr(&cpufreq_idr, cpufreq_dev->id);

remove_ida:

	ida_simple_remove(&cpufreq_ida, cpufreq_dev->id);

free_power_table:

	kfree(cpufreq_dev->dyn_power_table);

free_table:
@@ -1059,20 +1021,17 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) 


	cpufreq_dev = cdev->devdata;



	mutex_lock(&cooling_list_lock);

	/* 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);

	ida_simple_remove(&cpufreq_ida, cpufreq_dev->id);

	kfree(cpufreq_dev->dyn_power_table);

	kfree(cpufreq_dev->time_in_idle_timestamp);

	kfree(cpufreq_dev->time_in_idle);

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