[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)
{
	int cpu = policy->cpu;
	struct acpi_processor *pr = per_cpu(processors, cpu);
	int ret;

	if (!pr)
		return;

	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)
{
	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
c942fddf	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	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
1da177e4 LT	10	*/
	11
	12	#include <linux/kernel.h>
	13	#include <linux/module.h>
	14	#include <linux/init.h>
	15	#include <linux/cpufreq.h>
8b48463f	16	#include <linux/acpi.h>
1da177e4	17	#include <acpi/processor.h>
7c0f6ba6	18	#include <linux/uaccess.h>
1da177e4	19
a192a958 LB	20	#define PREFIX "ACPI: "
a192a958 LB	21
1da177e4	22	#define ACPI_PROCESSOR_CLASS "processor"
1da177e4	23	#define _COMPONENT ACPI_PROCESSOR_COMPONENT
f52fd66d	24	ACPI_MODULE_NAME("processor_thermal");
1da177e4	25
1da177e4 LT	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
d9460fd2 ZR	34	#define CPUFREQ_THERMAL_MIN_STEP 0
	35	#define CPUFREQ_THERMAL_MAX_STEP 3
	36
c938ac21	37	static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
1da177e4	38
2815ab92 AK	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
1da177e4 LT	60	static int cpu_has_cpufreq(unsigned int cpu)
	61	{
	62	struct cpufreq_policy policy;
d15ce412	63	if (!acpi_processor_cpufreq_init \|\| cpufreq_get_policy(&policy, cpu))
75b245b3 TR	64	return 0;
75b245b3 TR	65	return 1;
1da177e4 LT	66	}
1da177e4 LT	67
d9460fd2 ZR	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
2815ab92	81	return reduction_pctg(cpu);
d9460fd2 ZR	82	}
	83
	84	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	85	{
d15ce412 VK	86	struct cpufreq_policy *policy;
	87	struct acpi_processor *pr;
	88	unsigned long max_freq;
	89	int i, ret;
2815ab92	90
d9460fd2 ZR	91	if (!cpu_has_cpufreq(cpu))
	92	return 0;
	93
2815ab92 AK	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) {
d15ce412	102	if (topology_physical_package_id(i) !=
2815ab92	103	topology_physical_package_id(cpu))
d15ce412 VK	104	continue;
	105
	106	pr = per_cpu(processors, i);
	107
3000ce3c	108	if (unlikely(!freq_qos_request_active(&pr->thermal_req)))
d15ce412 VK	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
3000ce3c	119	ret = freq_qos_update_request(&pr->thermal_req, max_freq);
d15ce412 VK	120	if (ret < 0) {
	121	pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
	122	pr->id, ret);
	123	}
2815ab92	124	}
d9460fd2 ZR	125	return 0;
	126	}
	127
3000ce3c	128	void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy)
4be44fcd	129	{
3000ce3c	130	int cpu = policy->cpu;
d15ce412 VK	131	struct acpi_processor *pr = per_cpu(processors, cpu);
	132	int ret;
	133
2d8b39a6 RW	134	if (!pr)
	135	return;
	136
3000ce3c RW	137	ret = freq_qos_add_request(&policy->constraints, &pr->thermal_req,
3000ce3c RW	138	FREQ_QOS_MAX, INT_MAX);
2d8b39a6	139	if (ret < 0)
d15ce412 VK	140	pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu,
d15ce412 VK	141	ret);
1da177e4 LT	142	}
1da177e4 LT	143
3000ce3c	144	void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy)
4be44fcd	145	{
3000ce3c	146	struct acpi_processor *pr = per_cpu(processors, policy->cpu);
1da177e4	147
2d8b39a6	148	if (pr)
3000ce3c	149	freq_qos_remove_request(&pr->thermal_req);
1da177e4	150	}
4be44fcd	151	#else /* ! CONFIG_CPU_FREQ */
d9460fd2 ZR	152	static int cpufreq_get_max_state(unsigned int cpu)
	153	{
	154	return 0;
	155	}
	156
	157	static int cpufreq_get_cur_state(unsigned int cpu)
	158	{
	159	return 0;
	160	}
	161
	162	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	163	{
	164	return 0;
	165	}
1da177e4	166
1da177e4 LT	167	#endif
1da177e4 LT	168
6dd7aca8	169	/* thermal cooling device callbacks */
d9460fd2 ZR	170	static int acpi_processor_max_state(struct acpi_processor *pr)
	171	{
	172	int max_state = 0;
	173
	174	/*
	175	* There exists four states according to
6dd7aca8	176	* cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
d9460fd2 ZR	177	*/
	178	max_state += cpufreq_get_max_state(pr->id);
	179	if (pr->flags.throttling)
	180	max_state += (pr->throttling.state_count -1);
	181
	182	return max_state;
	183	}
	184	static int
6503e5df MG	185	processor_get_max_state(struct thermal_cooling_device *cdev,
6503e5df MG	186	unsigned long *state)
d9460fd2 ZR	187	{
d9460fd2 ZR	188	struct acpi_device *device = cdev->devdata;
99aa3638	189	struct acpi_processor *pr;
d9460fd2	190
99aa3638 CIK	191	if (!device)
	192	return -EINVAL;
	193
	194	pr = acpi_driver_data(device);
	195	if (!pr)
d9460fd2 ZR	196	return -EINVAL;
d9460fd2 ZR	197
6503e5df MG	198	*state = acpi_processor_max_state(pr);
6503e5df MG	199	return 0;
d9460fd2 ZR	200	}
	201
	202	static int
6503e5df MG	203	processor_get_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	204	unsigned long *cur_state)
d9460fd2 ZR	205	{
d9460fd2 ZR	206	struct acpi_device *device = cdev->devdata;
99aa3638	207	struct acpi_processor *pr;
d9460fd2	208
99aa3638 CIK	209	if (!device)
	210	return -EINVAL;
	211
	212	pr = acpi_driver_data(device);
	213	if (!pr)
d9460fd2 ZR	214	return -EINVAL;
d9460fd2 ZR	215
6503e5df	216	*cur_state = cpufreq_get_cur_state(pr->id);
d9460fd2	217	if (pr->flags.throttling)
6503e5df MG	218	*cur_state += pr->throttling.state;
6503e5df MG	219	return 0;
d9460fd2 ZR	220	}
	221
	222	static int
6503e5df MG	223	processor_set_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	224	unsigned long state)
d9460fd2 ZR	225	{
d9460fd2 ZR	226	struct acpi_device *device = cdev->devdata;
99aa3638	227	struct acpi_processor *pr;
d9460fd2 ZR	228	int result = 0;
	229	int max_pstate;
	230
99aa3638 CIK	231	if (!device)
	232	return -EINVAL;
	233
	234	pr = acpi_driver_data(device);
	235	if (!pr)
d9460fd2 ZR	236	return -EINVAL;
	237
	238	max_pstate = cpufreq_get_max_state(pr->id);
	239
	240	if (state > acpi_processor_max_state(pr))
	241	return -EINVAL;
	242
	243	if (state <= max_pstate) {
	244	if (pr->flags.throttling && pr->throttling.state)
2a908002	245	result = acpi_processor_set_throttling(pr, 0, false);
d9460fd2 ZR	246	cpufreq_set_cur_state(pr->id, state);
	247	} else {
	248	cpufreq_set_cur_state(pr->id, max_pstate);
	249	result = acpi_processor_set_throttling(pr,
2a908002	250	state - max_pstate, false);
d9460fd2 ZR	251	}
	252	return result;
	253	}
	254
9c8b04be	255	const struct thermal_cooling_device_ops processor_cooling_ops = {
d9460fd2 ZR	256	.get_max_state = processor_get_max_state,
	257	.get_cur_state = processor_get_cur_state,
	258	.set_cur_state = processor_set_cur_state,
	259	};