// 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> #define PREFIX "ACPI: " #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); #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_processor_cpufreq_init || cpufreq_get_policy(&policy, cpu))		return 0;	return 1;} 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){	struct cpufreq_policy *policy;	struct acpi_processor *pr;	unsigned long max_freq;	int i, ret; 	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))			continue; 		pr = per_cpu(processors, i); 		if (unlikely(!freq_qos_request_active(&pr->thermal_req)))			continue; 		policy = cpufreq_cpu_get(i);		if (!policy)			return -EINVAL; 		max_freq = (policy->cpuinfo.max_freq * (100 - reduction_pctg(i) * 20)) / 100; 		cpufreq_cpu_put(policy); 		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 0;} void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy){	unsigned int cpu; 	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);	}} 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, policy->cpu); 		if (pr)			freq_qos_remove_request(&pr->thermal_req);	}}#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_pctg. 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,};