[linux-block.git] / drivers / acpi / processor_thermal.c

// 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: "

#define ACPI_PROCESSOR_CLASS            "processor"
#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
ACPI_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);

#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 int
processor_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 int
processor_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 int
processor_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,
};
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* processor_thermal.c - Passive cooling submodule of the ACPI processor driver
	4	*
	5	* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
	6	* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
	7	* Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
	8	* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
	9	* - Added processor hotplug support
	10	*/
	11
	12	#include <linux/kernel.h>
	13	#include <linux/module.h>
	14	#include <linux/init.h>
	15	#include <linux/cpufreq.h>
	16	#include <linux/acpi.h>
	17	#include <acpi/processor.h>
	18	#include <linux/uaccess.h>
	19
	20	#define PREFIX "ACPI: "
	21
	22	#define ACPI_PROCESSOR_CLASS "processor"
	23	#define _COMPONENT ACPI_PROCESSOR_COMPONENT
	24	ACPI_MODULE_NAME("processor_thermal");
	25
	26	#ifdef CONFIG_CPU_FREQ
	27
	28	/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
	29	* offers (in most cases) voltage scaling in addition to frequency scaling, and
	30	* thus a cubic (instead of linear) reduction of energy. Also, we allow for
	31	* _any_ cpufreq driver and not only the acpi-cpufreq driver.
	32	*/
	33
	34	#define CPUFREQ_THERMAL_MIN_STEP 0
	35	#define CPUFREQ_THERMAL_MAX_STEP 3
	36
	37	static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
	38
	39	#define reduction_pctg(cpu) \
	40	per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
	41
	42	/*
	43	* Emulate "per package data" using per cpu data (which should really be
	44	* provided elsewhere)
	45	*
	46	* Note we can lose a CPU on cpu hotunplug, in this case we forget the state
	47	* temporarily. Fortunately that's not a big issue here (I hope)
	48	*/
	49	static int phys_package_first_cpu(int cpu)
	50	{
	51	int i;
	52	int id = topology_physical_package_id(cpu);
	53
	54	for_each_online_cpu(i)
	55	if (topology_physical_package_id(i) == id)
	56	return i;
	57	return 0;
	58	}
	59
	60	static int cpu_has_cpufreq(unsigned int cpu)
	61	{
	62	struct cpufreq_policy policy;
	63	if (!acpi_processor_cpufreq_init \|\| cpufreq_get_policy(&policy, cpu))
	64	return 0;
	65	return 1;
	66	}
	67
	68	static int cpufreq_get_max_state(unsigned int cpu)
	69	{
	70	if (!cpu_has_cpufreq(cpu))
	71	return 0;
	72
	73	return CPUFREQ_THERMAL_MAX_STEP;
	74	}
	75
	76	static int cpufreq_get_cur_state(unsigned int cpu)
	77	{
	78	if (!cpu_has_cpufreq(cpu))
	79	return 0;
	80
	81	return reduction_pctg(cpu);
	82	}
	83
	84	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	85	{
	86	struct cpufreq_policy *policy;
	87	struct acpi_processor *pr;
	88	unsigned long max_freq;
	89	int i, ret;
	90
	91	if (!cpu_has_cpufreq(cpu))
	92	return 0;
	93
	94	reduction_pctg(cpu) = state;
	95
	96	/*
	97	* Update all the CPUs in the same package because they all
	98	* contribute to the temperature and often share the same
	99	* frequency.
	100	*/
	101	for_each_online_cpu(i) {
	102	if (topology_physical_package_id(i) !=
	103	topology_physical_package_id(cpu))
	104	continue;
	105
	106	pr = per_cpu(processors, i);
	107
	108	if (unlikely(!freq_qos_request_active(&pr->thermal_req)))
	109	continue;
	110
	111	policy = cpufreq_cpu_get(i);
	112	if (!policy)
	113	return -EINVAL;
	114
	115	max_freq = (policy->cpuinfo.max_freq * (100 - reduction_pctg(i) * 20)) / 100;
	116
	117	cpufreq_cpu_put(policy);
	118
	119	ret = freq_qos_update_request(&pr->thermal_req, max_freq);
	120	if (ret < 0) {
	121	pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
	122	pr->id, ret);
	123	}
	124	}
	125	return 0;
	126	}
	127
	128	void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy)
	129	{
	130	unsigned int cpu;
	131
	132	for_each_cpu(cpu, policy->related_cpus) {
	133	struct acpi_processor *pr = per_cpu(processors, cpu);
	134	int ret;
	135
	136	if (!pr)
	137	continue;
	138
	139	ret = freq_qos_add_request(&policy->constraints,
	140	&pr->thermal_req,
	141	FREQ_QOS_MAX, INT_MAX);
	142	if (ret < 0)
	143	pr_err("Failed to add freq constraint for CPU%d (%d)\n",
	144	cpu, ret);
	145	}
	146	}
	147
	148	void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy)
	149	{
	150	unsigned int cpu;
	151
	152	for_each_cpu(cpu, policy->related_cpus) {
	153	struct acpi_processor *pr = per_cpu(processors, policy->cpu);
	154
	155	if (pr)
	156	freq_qos_remove_request(&pr->thermal_req);
	157	}
	158	}
	159	#else /* ! CONFIG_CPU_FREQ */
	160	static int cpufreq_get_max_state(unsigned int cpu)
	161	{
	162	return 0;
	163	}
	164
	165	static int cpufreq_get_cur_state(unsigned int cpu)
	166	{
	167	return 0;
	168	}
	169
	170	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	171	{
	172	return 0;
	173	}
	174
	175	#endif
	176
	177	/* thermal cooling device callbacks */
	178	static int acpi_processor_max_state(struct acpi_processor *pr)
	179	{
	180	int max_state = 0;
	181
	182	/*
	183	* There exists four states according to
	184	* cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
	185	*/
	186	max_state += cpufreq_get_max_state(pr->id);
	187	if (pr->flags.throttling)
	188	max_state += (pr->throttling.state_count -1);
	189
	190	return max_state;
	191	}
	192	static int
	193	processor_get_max_state(struct thermal_cooling_device *cdev,
	194	unsigned long *state)
	195	{
	196	struct acpi_device *device = cdev->devdata;
	197	struct acpi_processor *pr;
	198
	199	if (!device)
	200	return -EINVAL;
	201
	202	pr = acpi_driver_data(device);
	203	if (!pr)
	204	return -EINVAL;
	205
	206	*state = acpi_processor_max_state(pr);
	207	return 0;
	208	}
	209
	210	static int
	211	processor_get_cur_state(struct thermal_cooling_device *cdev,
	212	unsigned long *cur_state)
	213	{
	214	struct acpi_device *device = cdev->devdata;
	215	struct acpi_processor *pr;
	216
	217	if (!device)
	218	return -EINVAL;
	219
	220	pr = acpi_driver_data(device);
	221	if (!pr)
	222	return -EINVAL;
	223
	224	*cur_state = cpufreq_get_cur_state(pr->id);
	225	if (pr->flags.throttling)
	226	*cur_state += pr->throttling.state;
	227	return 0;
	228	}
	229
	230	static int
	231	processor_set_cur_state(struct thermal_cooling_device *cdev,
	232	unsigned long state)
	233	{
	234	struct acpi_device *device = cdev->devdata;
	235	struct acpi_processor *pr;
	236	int result = 0;
	237	int max_pstate;
	238
	239	if (!device)
	240	return -EINVAL;
	241
	242	pr = acpi_driver_data(device);
	243	if (!pr)
	244	return -EINVAL;
	245
	246	max_pstate = cpufreq_get_max_state(pr->id);
	247
	248	if (state > acpi_processor_max_state(pr))
	249	return -EINVAL;
	250
	251	if (state <= max_pstate) {
	252	if (pr->flags.throttling && pr->throttling.state)
	253	result = acpi_processor_set_throttling(pr, 0, false);
	254	cpufreq_set_cur_state(pr->id, state);
	255	} else {
	256	cpufreq_set_cur_state(pr->id, max_pstate);
	257	result = acpi_processor_set_throttling(pr,
	258	state - max_pstate, false);
	259	}
	260	return result;
	261	}
	262
	263	const struct thermal_cooling_device_ops processor_cooling_ops = {
	264	.get_max_state = processor_get_max_state,
	265	.get_cur_state = processor_get_cur_state,
	266	.set_cur_state = processor_set_cur_state,
	267	};