arch/powerpc/platforms/pseries/pseries_energy.c - arm/linux - Git at Google

 /*
  * POWER platform energy management driver
  * Copyright (C) 2010 IBM Corporation
  *
  * 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.
  *
  * This pseries platform device driver provides access to
  * platform energy management capabilities.
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/seq_file.h>
 #include <linux/device.h>
 #include <linux/cpu.h>
 #include <linux/of.h>
 #include <asm/cputhreads.h>
 #include <asm/page.h>
 #include <asm/hvcall.h>
 #include <asm/firmware.h>


 #define MODULE_VERS "1.0"
 #define MODULE_NAME "pseries_energy"

 /* Driver flags */

 static int sysfs_entries;

 /* Helper routines */

 /* Helper Routines to convert between drc_index to cpu numbers */

 static u32 cpu_to_drc_index(int cpu)
 {
 	struct device_node *dn = NULL;
 	const int *indexes;
 	int i;
 	int rc = 1;
 	u32 ret = 0;

 	dn = of_find_node_by_path("/cpus");
 	if (dn == NULL)
 		goto err;
 	indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
 	if (indexes == NULL)
 		goto err_of_node_put;
 	/* Convert logical cpu number to core number */
 	i = cpu_core_index_of_thread(cpu);
 	/*
 	 * The first element indexes[0] is the number of drc_indexes
 	 * returned in the list.  Hence i+1 will get the drc_index
 	 * corresponding to core number i.
 	 */
 	WARN_ON(i > indexes[0]);
 	ret = indexes[i + 1];
 	rc = 0;

 err_of_node_put:
 	of_node_put(dn);
 err:
 	if (rc)
 		printk(KERN_WARNING "cpu_to_drc_index(%d) failed", cpu);
 	return ret;
 }

 static int drc_index_to_cpu(u32 drc_index)
 {
 	struct device_node *dn = NULL;
 	const int *indexes;
 	int i, cpu = 0;
 	int rc = 1;

 	dn = of_find_node_by_path("/cpus");
 	if (dn == NULL)
 		goto err;
 	indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
 	if (indexes == NULL)
 		goto err_of_node_put;
 	/*
 	 * First element in the array is the number of drc_indexes
 	 * returned.  Search through the list to find the matching
 	 * drc_index and get the core number
 	 */
 	for (i = 0; i < indexes[0]; i++) {
 		if (indexes[i + 1] == drc_index)
 			break;
 	}
 	/* Convert core number to logical cpu number */
 	cpu = cpu_first_thread_of_core(i);
 	rc = 0;

 err_of_node_put:
 	of_node_put(dn);
 err:
 	if (rc)
 		printk(KERN_WARNING "drc_index_to_cpu(%d) failed", drc_index);
 	return cpu;
 }

 /*
  * pseries hypervisor call H_BEST_ENERGY provides hints to OS on
  * preferred logical cpus to activate or deactivate for optimized
  * energy consumption.
  */

 #define FLAGS_MODE1	0x004E200000080E01UL
 #define FLAGS_MODE2	0x004E200000080401UL
 #define FLAGS_ACTIVATE  0x100

 static ssize_t get_best_energy_list(char *page, int activate)
 {
 	int rc, cnt, i, cpu;
 	unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
 	unsigned long flags = 0;
 	u32 *buf_page;
 	char *s = page;

 	buf_page = (u32 *) get_zeroed_page(GFP_KERNEL);
 	if (!buf_page)
 		return -ENOMEM;

 	flags = FLAGS_MODE1;
 	if (activate)
 		flags |= FLAGS_ACTIVATE;

 	rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags, 0, __pa(buf_page),
 				0, 0, 0, 0, 0, 0);
 	if (rc != H_SUCCESS) {
 		free_page((unsigned long) buf_page);
 		return -EINVAL;
 	}

 	cnt = retbuf[0];
 	for (i = 0; i < cnt; i++) {
 		cpu = drc_index_to_cpu(buf_page[2*i+1]);
 		if ((cpu_online(cpu) && !activate) ||
 		    (!cpu_online(cpu) && activate))
 			s += sprintf(s, "%d,", cpu);
 	}
 	if (s > page) { /* Something to show */
 		s--; /* Suppress last comma */
 		s += sprintf(s, "\n");
 	}

 	free_page((unsigned long) buf_page);
 	return s-page;
 }

 static ssize_t get_best_energy_data(struct device *dev,
 					char *page, int activate)
 {
 	int rc;
 	unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
 	unsigned long flags = 0;

 	flags = FLAGS_MODE2;
 	if (activate)
 		flags |= FLAGS_ACTIVATE;

 	rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags,
 				cpu_to_drc_index(dev->id),
 				0, 0, 0, 0, 0, 0, 0);

 	if (rc != H_SUCCESS)
 		return -EINVAL;

 	return sprintf(page, "%lu\n", retbuf[1] >> 32);
 }

 /* Wrapper functions */

 static ssize_t cpu_activate_hint_list_show(struct device *dev,
 			struct device_attribute *attr, char *page)
 {
 	return get_best_energy_list(page, 1);
 }

 static ssize_t cpu_deactivate_hint_list_show(struct device *dev,
 			struct device_attribute *attr, char *page)
 {
 	return get_best_energy_list(page, 0);
 }

 static ssize_t percpu_activate_hint_show(struct device *dev,
 			struct device_attribute *attr, char *page)
 {
 	return get_best_energy_data(dev, page, 1);
 }

 static ssize_t percpu_deactivate_hint_show(struct device *dev,
 			struct device_attribute *attr, char *page)
 {
 	return get_best_energy_data(dev, page, 0);
 }

 /*
  * Create sysfs interface:
  * /sys/devices/system/cpu/pseries_activate_hint_list
  * /sys/devices/system/cpu/pseries_deactivate_hint_list
  *	Comma separated list of cpus to activate or deactivate
  * /sys/devices/system/cpu/cpuN/pseries_activate_hint
  * /sys/devices/system/cpu/cpuN/pseries_deactivate_hint
  *	Per-cpu value of the hint
  */

 static struct device_attribute attr_cpu_activate_hint_list =
 		__ATTR(pseries_activate_hint_list, 0444,
 		cpu_activate_hint_list_show, NULL);

 static struct device_attribute attr_cpu_deactivate_hint_list =
 		__ATTR(pseries_deactivate_hint_list, 0444,
 		cpu_deactivate_hint_list_show, NULL);

 static struct device_attribute attr_percpu_activate_hint =
 		__ATTR(pseries_activate_hint, 0444,
 		percpu_activate_hint_show, NULL);

 static struct device_attribute attr_percpu_deactivate_hint =
 		__ATTR(pseries_deactivate_hint, 0444,
 		percpu_deactivate_hint_show, NULL);

 static int __init pseries_energy_init(void)
 {
 	int cpu, err;
 	struct device *cpu_dev;

 	if (!firmware_has_feature(FW_FEATURE_BEST_ENERGY))
 		return 0; /* H_BEST_ENERGY hcall not supported */

 	/* Create the sysfs files */
 	err = device_create_file(cpu_subsys.dev_root,
 				&attr_cpu_activate_hint_list);
 	if (!err)
 		err = device_create_file(cpu_subsys.dev_root,
 				&attr_cpu_deactivate_hint_list);

 	if (err)
 		return err;
 	for_each_possible_cpu(cpu) {
 		cpu_dev = get_cpu_device(cpu);
 		err = device_create_file(cpu_dev,
 				&attr_percpu_activate_hint);
 		if (err)
 			break;
 		err = device_create_file(cpu_dev,
 				&attr_percpu_deactivate_hint);
 		if (err)
 			break;
 	}

 	if (err)
 		return err;

 	sysfs_entries = 1; /* Removed entries on cleanup */
 	return 0;

 }

 static void __exit pseries_energy_cleanup(void)
 {
 	int cpu;
 	struct device *cpu_dev;

 	if (!sysfs_entries)
 		return;

 	/* Remove the sysfs files */
 	device_remove_file(cpu_subsys.dev_root, &attr_cpu_activate_hint_list);
 	device_remove_file(cpu_subsys.dev_root, &attr_cpu_deactivate_hint_list);

 	for_each_possible_cpu(cpu) {
 		cpu_dev = get_cpu_device(cpu);
 		sysfs_remove_file(&cpu_dev->kobj,
 				&attr_percpu_activate_hint.attr);
 		sysfs_remove_file(&cpu_dev->kobj,
 				&attr_percpu_deactivate_hint.attr);
 	}
 }

 module_init(pseries_energy_init);
 module_exit(pseries_energy_cleanup);
 MODULE_DESCRIPTION("Driver for pSeries platform energy management");
 MODULE_AUTHOR("Vaidyanathan Srinivasan");
 MODULE_LICENSE("GPL");
	/*
	* POWER platform energy management driver
	* Copyright (C) 2010 IBM Corporation
	*
	* 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.
	*
	* This pseries platform device driver provides access to
	* platform energy management capabilities.
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/errno.h>
	#include <linux/init.h>
	#include <linux/seq_file.h>
	#include <linux/device.h>
	#include <linux/cpu.h>
	#include <linux/of.h>
	#include <asm/cputhreads.h>
	#include <asm/page.h>
	#include <asm/hvcall.h>
	#include <asm/firmware.h>


	#define MODULE_VERS "1.0"
	#define MODULE_NAME "pseries_energy"

	/* Driver flags */

	static int sysfs_entries;

	/* Helper routines */

	/* Helper Routines to convert between drc_index to cpu numbers */

	static u32 cpu_to_drc_index(int cpu)
	{
	struct device_node *dn = NULL;
	const int *indexes;
	int i;
	int rc = 1;
	u32 ret = 0;

	dn = of_find_node_by_path("/cpus");
	if (dn == NULL)
	goto err;
	indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
	if (indexes == NULL)
	goto err_of_node_put;
	/* Convert logical cpu number to core number */
	i = cpu_core_index_of_thread(cpu);
	/*
	* The first element indexes[0] is the number of drc_indexes
	* returned in the list. Hence i+1 will get the drc_index
	* corresponding to core number i.
	*/
	WARN_ON(i > indexes[0]);
	ret = indexes[i + 1];
	rc = 0;

	err_of_node_put:
	of_node_put(dn);
	err:
	if (rc)
	printk(KERN_WARNING "cpu_to_drc_index(%d) failed", cpu);
	return ret;
	}

	static int drc_index_to_cpu(u32 drc_index)
	{
	struct device_node *dn = NULL;
	const int *indexes;
	int i, cpu = 0;
	int rc = 1;

	dn = of_find_node_by_path("/cpus");
	if (dn == NULL)
	goto err;
	indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
	if (indexes == NULL)
	goto err_of_node_put;
	/*
	* First element in the array is the number of drc_indexes
	* returned. Search through the list to find the matching
	* drc_index and get the core number
	*/
	for (i = 0; i < indexes[0]; i++) {
	if (indexes[i + 1] == drc_index)
	break;
	}
	/* Convert core number to logical cpu number */
	cpu = cpu_first_thread_of_core(i);
	rc = 0;

	err_of_node_put:
	of_node_put(dn);
	err:
	if (rc)
	printk(KERN_WARNING "drc_index_to_cpu(%d) failed", drc_index);
	return cpu;
	}

	/*
	* pseries hypervisor call H_BEST_ENERGY provides hints to OS on
	* preferred logical cpus to activate or deactivate for optimized
	* energy consumption.
	*/

	#define FLAGS_MODE1 0x004E200000080E01UL
	#define FLAGS_MODE2 0x004E200000080401UL
	#define FLAGS_ACTIVATE 0x100

	static ssize_t get_best_energy_list(char *page, int activate)
	{
	int rc, cnt, i, cpu;
	unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
	unsigned long flags = 0;
	u32 *buf_page;
	char *s = page;

	buf_page = (u32 *) get_zeroed_page(GFP_KERNEL);
	if (!buf_page)
	return -ENOMEM;

	flags = FLAGS_MODE1;
	if (activate)
	flags \|= FLAGS_ACTIVATE;

	rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags, 0, __pa(buf_page),
	0, 0, 0, 0, 0, 0);
	if (rc != H_SUCCESS) {
	free_page((unsigned long) buf_page);
	return -EINVAL;
	}

	cnt = retbuf[0];
	for (i = 0; i < cnt; i++) {
	cpu = drc_index_to_cpu(buf_page[2*i+1]);
	if ((cpu_online(cpu) && !activate) \|\|
	(!cpu_online(cpu) && activate))
	s += sprintf(s, "%d,", cpu);
	}
	if (s > page) { /* Something to show */
	s--; /* Suppress last comma */
	s += sprintf(s, "\n");
	}

	free_page((unsigned long) buf_page);
	return s-page;
	}

	static ssize_t get_best_energy_data(struct device *dev,
	char *page, int activate)
	{
	int rc;
	unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
	unsigned long flags = 0;

	flags = FLAGS_MODE2;
	if (activate)
	flags \|= FLAGS_ACTIVATE;

	rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags,
	cpu_to_drc_index(dev->id),
	0, 0, 0, 0, 0, 0, 0);

	if (rc != H_SUCCESS)
	return -EINVAL;

	return sprintf(page, "%lu\n", retbuf[1] >> 32);
	}

	/* Wrapper functions */

	static ssize_t cpu_activate_hint_list_show(struct device *dev,
	struct device_attribute attr, char page)
	{
	return get_best_energy_list(page, 1);
	}

	static ssize_t cpu_deactivate_hint_list_show(struct device *dev,
	struct device_attribute attr, char page)
	{
	return get_best_energy_list(page, 0);
	}

	static ssize_t percpu_activate_hint_show(struct device *dev,
	struct device_attribute attr, char page)
	{
	return get_best_energy_data(dev, page, 1);
	}

	static ssize_t percpu_deactivate_hint_show(struct device *dev,
	struct device_attribute attr, char page)
	{
	return get_best_energy_data(dev, page, 0);
	}

	/*
	* Create sysfs interface:
	* /sys/devices/system/cpu/pseries_activate_hint_list
	* /sys/devices/system/cpu/pseries_deactivate_hint_list
	* Comma separated list of cpus to activate or deactivate
	* /sys/devices/system/cpu/cpuN/pseries_activate_hint
	* /sys/devices/system/cpu/cpuN/pseries_deactivate_hint
	* Per-cpu value of the hint
	*/

	static struct device_attribute attr_cpu_activate_hint_list =
	__ATTR(pseries_activate_hint_list, 0444,
	cpu_activate_hint_list_show, NULL);

	static struct device_attribute attr_cpu_deactivate_hint_list =
	__ATTR(pseries_deactivate_hint_list, 0444,
	cpu_deactivate_hint_list_show, NULL);

	static struct device_attribute attr_percpu_activate_hint =
	__ATTR(pseries_activate_hint, 0444,
	percpu_activate_hint_show, NULL);

	static struct device_attribute attr_percpu_deactivate_hint =
	__ATTR(pseries_deactivate_hint, 0444,
	percpu_deactivate_hint_show, NULL);

	static int __init pseries_energy_init(void)
	{
	int cpu, err;
	struct device *cpu_dev;

	if (!firmware_has_feature(FW_FEATURE_BEST_ENERGY))
	return 0; /* H_BEST_ENERGY hcall not supported */

	/* Create the sysfs files */
	err = device_create_file(cpu_subsys.dev_root,
	&attr_cpu_activate_hint_list);
	if (!err)
	err = device_create_file(cpu_subsys.dev_root,
	&attr_cpu_deactivate_hint_list);

	if (err)
	return err;
	for_each_possible_cpu(cpu) {
	cpu_dev = get_cpu_device(cpu);
	err = device_create_file(cpu_dev,
	&attr_percpu_activate_hint);
	if (err)
	break;
	err = device_create_file(cpu_dev,
	&attr_percpu_deactivate_hint);
	if (err)
	break;
	}

	if (err)
	return err;

	sysfs_entries = 1; /* Removed entries on cleanup */
	return 0;

	}

	static void __exit pseries_energy_cleanup(void)
	{
	int cpu;
	struct device *cpu_dev;

	if (!sysfs_entries)
	return;

	/* Remove the sysfs files */
	device_remove_file(cpu_subsys.dev_root, &attr_cpu_activate_hint_list);
	device_remove_file(cpu_subsys.dev_root, &attr_cpu_deactivate_hint_list);

	for_each_possible_cpu(cpu) {
	cpu_dev = get_cpu_device(cpu);
	sysfs_remove_file(&cpu_dev->kobj,
	&attr_percpu_activate_hint.attr);
	sysfs_remove_file(&cpu_dev->kobj,
	&attr_percpu_deactivate_hint.attr);
	}
	}

	module_init(pseries_energy_init);
	module_exit(pseries_energy_cleanup);
	MODULE_DESCRIPTION("Driver for pSeries platform energy management");
	MODULE_AUTHOR("Vaidyanathan Srinivasan");
	MODULE_LICENSE("GPL");