// SPDX-License-Identifier: GPL-2.0-or-later/* * 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 */ #include <linux/kernel.h>#include <linux/module.h>#include <linux/init.h>#include <linux/cpufreq.h>#include <linux/acpi.h>#include <acpi/processor.h>#include <linux/uaccess.h> #include "internal.h" #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 static int cpufreq_thermal_max_step __read_mostly = 3; /* * Minimum throttle percentage for processor_thermal cooling device. * The processor_thermal driver uses it to calculate the percentage amount by * which cpu frequency must be reduced for each cooling state. This is also used * to calculate the maximum number of throttling steps or cooling states. */static int cpufreq_thermal_reduction_pctg __read_mostly = 20; static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_step); #define reduction_step(cpu) \	per_cpu(cpufreq_thermal_reduction_step, 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 bool cpu_has_cpufreq(unsigned int cpu){	if (!acpi_processor_cpufreq_init)		return 0; 	struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu); 	return policy != NULL;} 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_step(cpu);} static bool cpufreq_update_thermal_limit(unsigned int cpu, struct acpi_processor *pr){	unsigned long max_freq;	int ret; 	struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu);	if (!policy)		return false; 	max_freq = (policy->cpuinfo.max_freq *		(100 - reduction_step(cpu) * cpufreq_thermal_reduction_pctg)) / 100; 	ret = freq_qos_update_request(&pr->thermal_req, max_freq);	if (ret < 0) {		pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",			pr->id, ret);	} 	return true;} static int cpufreq_set_cur_state(unsigned int cpu, int state){	struct acpi_processor *pr;	int i; 	if (!cpu_has_cpufreq(cpu))		return 0; 	reduction_step(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))			continue; 		pr = per_cpu(processors, i); 		if (unlikely(!freq_qos_request_active(&pr->thermal_req)))			continue; 		if (!cpufreq_update_thermal_limit(i, pr))			return -EINVAL;	}	return 0;} static void acpi_thermal_cpufreq_config(void){	int cpufreq_pctg = acpi_arch_thermal_cpufreq_pctg(); 	if (!cpufreq_pctg)		return; 	cpufreq_thermal_reduction_pctg = cpufreq_pctg; 	/*	 * Derive the MAX_STEP from minimum throttle percentage so that the reduction	 * percentage doesn't end up becoming negative. Also, cap the MAX_STEP so that	 * the CPU performance doesn't become 0.	 */	cpufreq_thermal_max_step = (100 / cpufreq_pctg) - 2;} void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy){	unsigned int cpu; 	acpi_thermal_cpufreq_config(); 	for_each_cpu(cpu, policy->related_cpus) {		struct acpi_processor *pr = per_cpu(processors, cpu);		int ret; 		if (!pr)			continue; 		ret = freq_qos_add_request(&policy->constraints,					   &pr->thermal_req,					   FREQ_QOS_MAX, INT_MAX);		if (ret < 0) {			pr_err("Failed to add freq constraint for CPU%d (%d)\n",			       cpu, ret);			continue;		} 		thermal_cooling_device_update(pr->cdev);	}} void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy){	unsigned int cpu; 	for_each_cpu(cpu, policy->related_cpus) {		struct acpi_processor *pr = per_cpu(processors, cpu); 		if (!pr)			continue; 		freq_qos_remove_request(&pr->thermal_req); 		thermal_cooling_device_update(pr->cdev);	}}#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 /* thermal cooling 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_step. 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; 	if (!device)		return -EINVAL; 	pr = acpi_driver_data(device);	if (!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; 	if (!device)		return -EINVAL; 	pr = acpi_driver_data(device);	if (!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;	int result = 0;	int max_pstate; 	if (!device)		return -EINVAL; 	pr = acpi_driver_data(device);	if (!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,}; int acpi_processor_thermal_init(struct acpi_processor *pr,				struct acpi_device *device){	int result = 0; 	pr->cdev = thermal_cooling_device_register("Processor", device,						   &processor_cooling_ops);	if (IS_ERR(pr->cdev)) {		result = PTR_ERR(pr->cdev);		return result;	} 	dev_dbg(&device->dev, "registered as cooling_device%d\n",		pr->cdev->id); 	result = sysfs_create_link(&device->dev.kobj,				   &pr->cdev->device.kobj,				   "thermal_cooling");	if (result) {		dev_err(&device->dev,			"Failed to create sysfs link 'thermal_cooling'\n");		goto err_thermal_unregister;	} 	result = sysfs_create_link(&pr->cdev->device.kobj,				   &device->dev.kobj,				   "device");	if (result) {		dev_err(&pr->cdev->device,			"Failed to create sysfs link 'device'\n");		goto err_remove_sysfs_thermal;	} 	return 0; err_remove_sysfs_thermal:	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");err_thermal_unregister:	thermal_cooling_device_unregister(pr->cdev); 	return result;} void acpi_processor_thermal_exit(struct acpi_processor *pr,				 struct acpi_device *device){	if (pr->cdev) {		sysfs_remove_link(&device->dev.kobj, "thermal_cooling");		sysfs_remove_link(&pr->cdev->device.kobj, "device");		thermal_cooling_device_unregister(pr->cdev);		pr->cdev = NULL;	}}