/* * processor_thermal.c - Passive cooling submodule of the ACPI processor driver * *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de> *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> *  			- Added processor hotplug support * * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * *  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; either version 2 of the License, or (at *  your option) any later version. * *  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/kernel.h>#include <linux/module.h>#include <linux/init.h>#include <linux/cpufreq.h> #include <asm/uaccess.h> #include <acpi/acpi_bus.h>#include <acpi/processor.h>#include <acpi/acpi_drivers.h> #define PREFIX "ACPI: " #define ACPI_PROCESSOR_CLASS            "processor"#define _COMPONENT              ACPI_PROCESSOR_COMPONENTACPI_MODULE_NAME("processor_thermal"); #ifdef CONFIG_CPU_FREQ /* If a passive cooling situation is detected, primarily CPUfreq is used, as it * offers (in most cases) voltage scaling in addition to frequency scaling, and * thus a cubic (instead of linear) reduction of energy. Also, we allow for * _any_ cpufreq driver and not only the acpi-cpufreq driver. */ #define CPUFREQ_THERMAL_MIN_STEP 0#define CPUFREQ_THERMAL_MAX_STEP 3 static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);static unsigned int acpi_thermal_cpufreq_is_init = 0; #define reduction_pctg(cpu) \	per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu)) /* * Emulate "per package data" using per cpu data (which should really be * provided elsewhere) * * Note we can lose a CPU on cpu hotunplug, in this case we forget the state * temporarily. Fortunately that's not a big issue here (I hope) */static int phys_package_first_cpu(int cpu){	int i;	int id = topology_physical_package_id(cpu); 	for_each_online_cpu(i)		if (topology_physical_package_id(i) == id)			return i;	return 0;} static int cpu_has_cpufreq(unsigned int cpu){	struct cpufreq_policy policy;	if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))		return 0;	return 1;} static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,					 unsigned long event, void *data){	struct cpufreq_policy *policy = data;	unsigned long max_freq = 0; 	if (event != CPUFREQ_ADJUST)		goto out; 	max_freq = (	    policy->cpuinfo.max_freq *	    (100 - reduction_pctg(policy->cpu) * 20)	) / 100; 	cpufreq_verify_within_limits(policy, 0, max_freq);       out:	return 0;} static struct notifier_block acpi_thermal_cpufreq_notifier_block = {	.notifier_call = acpi_thermal_cpufreq_notifier,}; static int cpufreq_get_max_state(unsigned int cpu){	if (!cpu_has_cpufreq(cpu))		return 0; 	return CPUFREQ_THERMAL_MAX_STEP;} static int cpufreq_get_cur_state(unsigned int cpu){	if (!cpu_has_cpufreq(cpu))		return 0; 	return reduction_pctg(cpu);} static int cpufreq_set_cur_state(unsigned int cpu, int state){	int i; 	if (!cpu_has_cpufreq(cpu))		return 0; 	reduction_pctg(cpu) = state; 	/*	 * Update all the CPUs in the same package because they all	 * contribute to the temperature and often share the same	 * frequency.	 */	for_each_online_cpu(i) {		if (topology_physical_package_id(i) ==		    topology_physical_package_id(cpu))			cpufreq_update_policy(i);	}	return 0;} void acpi_thermal_cpufreq_init(void){	int i; 	i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,				      CPUFREQ_POLICY_NOTIFIER);	if (!i)		acpi_thermal_cpufreq_is_init = 1;} void acpi_thermal_cpufreq_exit(void){	if (acpi_thermal_cpufreq_is_init)		cpufreq_unregister_notifier		    (&acpi_thermal_cpufreq_notifier_block,		     CPUFREQ_POLICY_NOTIFIER); 	acpi_thermal_cpufreq_is_init = 0;} #else				/* ! CONFIG_CPU_FREQ */static int cpufreq_get_max_state(unsigned int cpu){	return 0;} static int cpufreq_get_cur_state(unsigned int cpu){	return 0;} static int cpufreq_set_cur_state(unsigned int cpu, int state){	return 0;} #endif int acpi_processor_get_limit_info(struct acpi_processor *pr){ 	if (!pr)		return -EINVAL; 	if (pr->flags.throttling)		pr->flags.limit = 1; 	return 0;} /* thermal coolign device callbacks */static int acpi_processor_max_state(struct acpi_processor *pr){	int max_state = 0; 	/*	 * There exists four states according to	 * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3	 */	max_state += cpufreq_get_max_state(pr->id);	if (pr->flags.throttling)		max_state += (pr->throttling.state_count -1); 	return max_state;}static intprocessor_get_max_state(struct thermal_cooling_device *cdev,			unsigned long *state){	struct acpi_device *device = cdev->devdata;	struct acpi_processor *pr = acpi_driver_data(device); 	if (!device || !pr)		return -EINVAL; 	*state = acpi_processor_max_state(pr);	return 0;} static intprocessor_get_cur_state(struct thermal_cooling_device *cdev,			unsigned long *cur_state){	struct acpi_device *device = cdev->devdata;	struct acpi_processor *pr = acpi_driver_data(device); 	if (!device || !pr)		return -EINVAL; 	*cur_state = cpufreq_get_cur_state(pr->id);	if (pr->flags.throttling)		*cur_state += pr->throttling.state;	return 0;} static intprocessor_set_cur_state(struct thermal_cooling_device *cdev,			unsigned long state){	struct acpi_device *device = cdev->devdata;	struct acpi_processor *pr = acpi_driver_data(device);	int result = 0;	int max_pstate; 	if (!device || !pr)		return -EINVAL; 	max_pstate = cpufreq_get_max_state(pr->id); 	if (state > acpi_processor_max_state(pr))		return -EINVAL; 	if (state <= max_pstate) {		if (pr->flags.throttling && pr->throttling.state)			result = acpi_processor_set_throttling(pr, 0, false);		cpufreq_set_cur_state(pr->id, state);	} else {		cpufreq_set_cur_state(pr->id, max_pstate);		result = acpi_processor_set_throttling(pr,				state - max_pstate, false);	}	return result;} const struct thermal_cooling_device_ops processor_cooling_ops = {	.get_max_state = processor_get_max_state,	.get_cur_state = processor_get_cur_state,	.set_cur_state = processor_set_cur_state,};