drivers/base/power/opp/cpu.c - kernel/bruno - Git at Google

 /*
  * Generic OPP helper interface for CPU device
  *
  * Copyright (C) 2009-2014 Texas Instruments Incorporated.
  *	Nishanth Menon
  *	Romit Dasgupta
  *	Kevin Hilman
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/export.h>
 #include <linux/of.h>
 #include <linux/slab.h>

 #include "opp.h"

 #ifdef CONFIG_CPU_FREQ

 /**
  * dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device
  * @dev:	device for which we do this operation
  * @table:	Cpufreq table returned back to caller
  *
  * Generate a cpufreq table for a provided device- this assumes that the
  * opp list is already initialized and ready for usage.
  *
  * This function allocates required memory for the cpufreq table. It is
  * expected that the caller does the required maintenance such as freeing
  * the table as required.
  *
  * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM
  * if no memory available for the operation (table is not populated), returns 0
  * if successful and table is populated.
  *
  * WARNING: It is  important for the callers to ensure refreshing their copy of
  * the table if any of the mentioned functions have been invoked in the interim.
  *
  * Locking: The internal device_opp and opp structures are RCU protected.
  * Since we just use the regular accessor functions to access the internal data
  * structures, we use RCU read lock inside this function. As a result, users of
  * this function DONOT need to use explicit locks for invoking.
  */
 int dev_pm_opp_init_cpufreq_table(struct device *dev,
 				  struct cpufreq_frequency_table **table)
 {
 	struct dev_pm_opp *opp;
 	struct cpufreq_frequency_table *freq_table = NULL;
 	int i, max_opps, ret = 0;
 	unsigned long rate;

 	rcu_read_lock();

 	max_opps = dev_pm_opp_get_opp_count(dev);
 	if (max_opps <= 0) {
 		ret = max_opps ? max_opps : -ENODATA;
 		goto out;
 	}

 	freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_ATOMIC);
 	if (!freq_table) {
 		ret = -ENOMEM;
 		goto out;
 	}

 	for (i = 0, rate = 0; i < max_opps; i++, rate++) {
 		/* find next rate */
 		opp = dev_pm_opp_find_freq_ceil(dev, &rate);
 		if (IS_ERR(opp)) {
 			ret = PTR_ERR(opp);
 			goto out;
 		}
 		freq_table[i].driver_data = i;
 		freq_table[i].frequency = rate / 1000;

 		/* Is Boost/turbo opp ? */
 		if (dev_pm_opp_is_turbo(opp))
 			freq_table[i].flags = CPUFREQ_BOOST_FREQ;
 	}

 	freq_table[i].driver_data = i;
 	freq_table[i].frequency = CPUFREQ_TABLE_END;

 	*table = &freq_table[0];

 out:
 	rcu_read_unlock();
 	if (ret)
 		kfree(freq_table);

 	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table);

 /**
  * dev_pm_opp_free_cpufreq_table() - free the cpufreq table
  * @dev:	device for which we do this operation
  * @table:	table to free
  *
  * Free up the table allocated by dev_pm_opp_init_cpufreq_table
  */
 void dev_pm_opp_free_cpufreq_table(struct device *dev,
 				   struct cpufreq_frequency_table **table)
 {
 	if (!table)
 		return;

 	kfree(*table);
 	*table = NULL;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
 #endif	/* CONFIG_CPU_FREQ */

 /* Required only for V1 bindings, as v2 can manage it from DT itself */
 int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
 {
 	struct device_list_opp *list_dev;
 	struct device_opp *dev_opp;
 	struct device *dev;
 	int cpu, ret = 0;

 	mutex_lock(&dev_opp_list_lock);

 	dev_opp = _find_device_opp(cpu_dev);
 	if (IS_ERR(dev_opp)) {
 		ret = -EINVAL;
 		goto unlock;
 	}

 	for_each_cpu(cpu, cpumask) {
 		if (cpu == cpu_dev->id)
 			continue;

 		dev = get_cpu_device(cpu);
 		if (!dev) {
 			dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
 				__func__, cpu);
 			continue;
 		}

 		list_dev = _add_list_dev(dev, dev_opp);
 		if (!list_dev) {
 			dev_err(dev, "%s: failed to add list-dev for cpu%d device\n",
 				__func__, cpu);
 			continue;
 		}
 	}
 unlock:
 	mutex_unlock(&dev_opp_list_lock);

 	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);

 #ifdef CONFIG_OF
 void dev_pm_opp_of_cpumask_remove_table(cpumask_var_t cpumask)
 {
 	struct device *cpu_dev;
 	int cpu;

 	WARN_ON(cpumask_empty(cpumask));

 	for_each_cpu(cpu, cpumask) {
 		cpu_dev = get_cpu_device(cpu);
 		if (!cpu_dev) {
 			pr_err("%s: failed to get cpu%d device\n", __func__,
 			       cpu);
 			continue;
 		}

 		dev_pm_opp_of_remove_table(cpu_dev);
 	}
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);

 int dev_pm_opp_of_cpumask_add_table(cpumask_var_t cpumask)
 {
 	struct device *cpu_dev;
 	int cpu, ret = 0;

 	WARN_ON(cpumask_empty(cpumask));

 	for_each_cpu(cpu, cpumask) {
 		cpu_dev = get_cpu_device(cpu);
 		if (!cpu_dev) {
 			pr_err("%s: failed to get cpu%d device\n", __func__,
 			       cpu);
 			continue;
 		}

 		ret = dev_pm_opp_of_add_table(cpu_dev);
 		if (ret) {
 			pr_err("%s: couldn't find opp table for cpu:%d, %d\n",
 			       __func__, cpu, ret);

 			/* Free all other OPPs */
 			dev_pm_opp_of_cpumask_remove_table(cpumask);
 			break;
 		}
 	}

 	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);

 /*
  * Works only for OPP v2 bindings.
  *
  * cpumask should be already set to mask of cpu_dev->id.
  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
  */
 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
 {
 	struct device_node *np, *tmp_np;
 	struct device *tcpu_dev;
 	int cpu, ret = 0;

 	/* Get OPP descriptor node */
 	np = _of_get_opp_desc_node(cpu_dev);
 	if (!np) {
 		dev_dbg(cpu_dev, "%s: Couldn't find cpu_dev node.\n", __func__);
 		return -ENOENT;
 	}

 	/* OPPs are shared ? */
 	if (!of_property_read_bool(np, "opp-shared"))
 		goto put_cpu_node;

 	for_each_possible_cpu(cpu) {
 		if (cpu == cpu_dev->id)
 			continue;

 		tcpu_dev = get_cpu_device(cpu);
 		if (!tcpu_dev) {
 			dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
 				__func__, cpu);
 			ret = -ENODEV;
 			goto put_cpu_node;
 		}

 		/* Get OPP descriptor node */
 		tmp_np = _of_get_opp_desc_node(tcpu_dev);
 		if (!tmp_np) {
 			dev_err(tcpu_dev, "%s: Couldn't find tcpu_dev node.\n",
 				__func__);
 			ret = -ENOENT;
 			goto put_cpu_node;
 		}

 		/* CPUs are sharing opp node */
 		if (np == tmp_np)
 			cpumask_set_cpu(cpu, cpumask);

 		of_node_put(tmp_np);
 	}

 put_cpu_node:
 	of_node_put(np);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
 #endif
	/*
	* Generic OPP helper interface for CPU device
	*
	* Copyright (C) 2009-2014 Texas Instruments Incorporated.
	* Nishanth Menon
	* Romit Dasgupta
	* Kevin Hilman
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/cpu.h>
	#include <linux/cpufreq.h>
	#include <linux/err.h>
	#include <linux/errno.h>
	#include <linux/export.h>
	#include <linux/of.h>
	#include <linux/slab.h>

	#include "opp.h"

	#ifdef CONFIG_CPU_FREQ

	/**
	* dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device
	* @dev: device for which we do this operation
	* @table: Cpufreq table returned back to caller
	*
	* Generate a cpufreq table for a provided device- this assumes that the
	* opp list is already initialized and ready for usage.
	*
	* This function allocates required memory for the cpufreq table. It is
	* expected that the caller does the required maintenance such as freeing
	* the table as required.
	*
	* Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM
	* if no memory available for the operation (table is not populated), returns 0
	* if successful and table is populated.
	*
	* WARNING: It is important for the callers to ensure refreshing their copy of
	* the table if any of the mentioned functions have been invoked in the interim.
	*
	* Locking: The internal device_opp and opp structures are RCU protected.
	* Since we just use the regular accessor functions to access the internal data
	* structures, we use RCU read lock inside this function. As a result, users of
	* this function DONOT need to use explicit locks for invoking.
	*/
	int dev_pm_opp_init_cpufreq_table(struct device *dev,
	struct cpufreq_frequency_table **table)
	{
	struct dev_pm_opp *opp;
	struct cpufreq_frequency_table *freq_table = NULL;
	int i, max_opps, ret = 0;
	unsigned long rate;

	rcu_read_lock();

	max_opps = dev_pm_opp_get_opp_count(dev);
	if (max_opps <= 0) {
	ret = max_opps ? max_opps : -ENODATA;
	goto out;
	}

	freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_ATOMIC);
	if (!freq_table) {
	ret = -ENOMEM;
	goto out;
	}

	for (i = 0, rate = 0; i < max_opps; i++, rate++) {
	/* find next rate */
	opp = dev_pm_opp_find_freq_ceil(dev, &rate);
	if (IS_ERR(opp)) {
	ret = PTR_ERR(opp);
	goto out;
	}
	freq_table[i].driver_data = i;
	freq_table[i].frequency = rate / 1000;

	/* Is Boost/turbo opp ? */
	if (dev_pm_opp_is_turbo(opp))
	freq_table[i].flags = CPUFREQ_BOOST_FREQ;
	}

	freq_table[i].driver_data = i;
	freq_table[i].frequency = CPUFREQ_TABLE_END;

	*table = &freq_table[0];

	out:
	rcu_read_unlock();
	if (ret)
	kfree(freq_table);

	return ret;
	}
	EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table);

	/**
	* dev_pm_opp_free_cpufreq_table() - free the cpufreq table
	* @dev: device for which we do this operation
	* @table: table to free
	*
	* Free up the table allocated by dev_pm_opp_init_cpufreq_table
	*/
	void dev_pm_opp_free_cpufreq_table(struct device *dev,
	struct cpufreq_frequency_table **table)
	{
	if (!table)
	return;

	kfree(*table);
	*table = NULL;
	}
	EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
	#endif /* CONFIG_CPU_FREQ */

	/* Required only for V1 bindings, as v2 can manage it from DT itself */
	int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
	{
	struct device_list_opp *list_dev;
	struct device_opp *dev_opp;
	struct device *dev;
	int cpu, ret = 0;

	mutex_lock(&dev_opp_list_lock);

	dev_opp = _find_device_opp(cpu_dev);
	if (IS_ERR(dev_opp)) {
	ret = -EINVAL;
	goto unlock;
	}

	for_each_cpu(cpu, cpumask) {
	if (cpu == cpu_dev->id)
	continue;

	dev = get_cpu_device(cpu);
	if (!dev) {
	dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
	__func__, cpu);
	continue;
	}

	list_dev = _add_list_dev(dev, dev_opp);
	if (!list_dev) {
	dev_err(dev, "%s: failed to add list-dev for cpu%d device\n",
	__func__, cpu);
	continue;
	}
	}
	unlock:
	mutex_unlock(&dev_opp_list_lock);

	return ret;
	}
	EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);

	#ifdef CONFIG_OF
	void dev_pm_opp_of_cpumask_remove_table(cpumask_var_t cpumask)
	{
	struct device *cpu_dev;
	int cpu;

	WARN_ON(cpumask_empty(cpumask));

	for_each_cpu(cpu, cpumask) {
	cpu_dev = get_cpu_device(cpu);
	if (!cpu_dev) {
	pr_err("%s: failed to get cpu%d device\n", __func__,
	cpu);
	continue;
	}

	dev_pm_opp_of_remove_table(cpu_dev);
	}
	}
	EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);

	int dev_pm_opp_of_cpumask_add_table(cpumask_var_t cpumask)
	{
	struct device *cpu_dev;
	int cpu, ret = 0;

	WARN_ON(cpumask_empty(cpumask));

	for_each_cpu(cpu, cpumask) {
	cpu_dev = get_cpu_device(cpu);
	if (!cpu_dev) {
	pr_err("%s: failed to get cpu%d device\n", __func__,
	cpu);
	continue;
	}

	ret = dev_pm_opp_of_add_table(cpu_dev);
	if (ret) {
	pr_err("%s: couldn't find opp table for cpu:%d, %d\n",
	__func__, cpu, ret);

	/* Free all other OPPs */
	dev_pm_opp_of_cpumask_remove_table(cpumask);
	break;
	}
	}

	return ret;
	}
	EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);

	/*
	* Works only for OPP v2 bindings.
	*
	* cpumask should be already set to mask of cpu_dev->id.
	* Returns -ENOENT if operating-points-v2 bindings aren't supported.
	*/
	int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
	{
	struct device_node np, tmp_np;
	struct device *tcpu_dev;
	int cpu, ret = 0;

	/* Get OPP descriptor node */
	np = _of_get_opp_desc_node(cpu_dev);
	if (!np) {
	dev_dbg(cpu_dev, "%s: Couldn't find cpu_dev node.\n", __func__);
	return -ENOENT;
	}

	/* OPPs are shared ? */
	if (!of_property_read_bool(np, "opp-shared"))
	goto put_cpu_node;

	for_each_possible_cpu(cpu) {
	if (cpu == cpu_dev->id)
	continue;

	tcpu_dev = get_cpu_device(cpu);
	if (!tcpu_dev) {
	dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
	__func__, cpu);
	ret = -ENODEV;
	goto put_cpu_node;
	}

	/* Get OPP descriptor node */
	tmp_np = _of_get_opp_desc_node(tcpu_dev);
	if (!tmp_np) {
	dev_err(tcpu_dev, "%s: Couldn't find tcpu_dev node.\n",
	__func__);
	ret = -ENOENT;
	goto put_cpu_node;
	}

	/* CPUs are sharing opp node */
	if (np == tmp_np)
	cpumask_set_cpu(cpu, cpumask);

	of_node_put(tmp_np);
	}

	put_cpu_node:
	of_node_put(np);
	return ret;
	}
	EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
	#endif