[linux-2.6-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"

#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
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
1da177e4 LT	24	#ifdef CONFIG_CPU_FREQ
	25
	26	/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
	27	* offers (in most cases) voltage scaling in addition to frequency scaling, and
	28	* thus a cubic (instead of linear) reduction of energy. Also, we allow for
	29	* _any_ cpufreq driver and not only the acpi-cpufreq driver.
	30	*/
	31
d9460fd2 ZR	32	#define CPUFREQ_THERMAL_MIN_STEP 0
	33	#define CPUFREQ_THERMAL_MAX_STEP 3
	34
c938ac21	35	static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
1da177e4	36
2815ab92 AK	37	#define reduction_pctg(cpu) \
	38	per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
	39
	40	/*
	41	* Emulate "per package data" using per cpu data (which should really be
	42	* provided elsewhere)
	43	*
	44	* Note we can lose a CPU on cpu hotunplug, in this case we forget the state
	45	* temporarily. Fortunately that's not a big issue here (I hope)
	46	*/
	47	static int phys_package_first_cpu(int cpu)
	48	{
	49	int i;
	50	int id = topology_physical_package_id(cpu);
	51
	52	for_each_online_cpu(i)
	53	if (topology_physical_package_id(i) == id)
	54	return i;
	55	return 0;
	56	}
	57
1da177e4 LT	58	static int cpu_has_cpufreq(unsigned int cpu)
	59	{
	60	struct cpufreq_policy policy;
d15ce412	61	if (!acpi_processor_cpufreq_init \|\| cpufreq_get_policy(&policy, cpu))
75b245b3 TR	62	return 0;
75b245b3 TR	63	return 1;
1da177e4 LT	64	}
1da177e4 LT	65
d9460fd2 ZR	66	static int cpufreq_get_max_state(unsigned int cpu)
	67	{
	68	if (!cpu_has_cpufreq(cpu))
	69	return 0;
	70
	71	return CPUFREQ_THERMAL_MAX_STEP;
	72	}
	73
	74	static int cpufreq_get_cur_state(unsigned int cpu)
	75	{
	76	if (!cpu_has_cpufreq(cpu))
	77	return 0;
	78
2815ab92	79	return reduction_pctg(cpu);
d9460fd2 ZR	80	}
	81
	82	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	83	{
d15ce412 VK	84	struct cpufreq_policy *policy;
	85	struct acpi_processor *pr;
	86	unsigned long max_freq;
	87	int i, ret;
2815ab92	88
d9460fd2 ZR	89	if (!cpu_has_cpufreq(cpu))
	90	return 0;
	91
2815ab92 AK	92	reduction_pctg(cpu) = state;
	93
	94	/*
	95	* Update all the CPUs in the same package because they all
	96	* contribute to the temperature and often share the same
	97	* frequency.
	98	*/
	99	for_each_online_cpu(i) {
d15ce412	100	if (topology_physical_package_id(i) !=
2815ab92	101	topology_physical_package_id(cpu))
d15ce412 VK	102	continue;
	103
	104	pr = per_cpu(processors, i);
	105
3000ce3c	106	if (unlikely(!freq_qos_request_active(&pr->thermal_req)))
d15ce412 VK	107	continue;
	108
	109	policy = cpufreq_cpu_get(i);
	110	if (!policy)
	111	return -EINVAL;
	112
	113	max_freq = (policy->cpuinfo.max_freq * (100 - reduction_pctg(i) * 20)) / 100;
	114
	115	cpufreq_cpu_put(policy);
	116
3000ce3c	117	ret = freq_qos_update_request(&pr->thermal_req, max_freq);
d15ce412 VK	118	if (ret < 0) {
	119	pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
	120	pr->id, ret);
	121	}
2815ab92	122	}
d9460fd2 ZR	123	return 0;
	124	}
	125
3000ce3c	126	void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy)
4be44fcd	127	{
a1bb46c3 RW	128	unsigned int cpu;
	129
	130	for_each_cpu(cpu, policy->related_cpus) {
	131	struct acpi_processor *pr = per_cpu(processors, cpu);
	132	int ret;
	133
	134	if (!pr)
	135	continue;
	136
	137	ret = freq_qos_add_request(&policy->constraints,
	138	&pr->thermal_req,
	139	FREQ_QOS_MAX, INT_MAX);
	140	if (ret < 0)
	141	pr_err("Failed to add freq constraint for CPU%d (%d)\n",
	142	cpu, ret);
	143	}
1da177e4 LT	144	}
1da177e4 LT	145
3000ce3c	146	void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy)
4be44fcd	147	{
a1bb46c3 RW	148	unsigned int cpu;
	149
	150	for_each_cpu(cpu, policy->related_cpus) {
	151	struct acpi_processor *pr = per_cpu(processors, policy->cpu);
1da177e4	152
a1bb46c3 RW	153	if (pr)
	154	freq_qos_remove_request(&pr->thermal_req);
	155	}
1da177e4	156	}
4be44fcd	157	#else /* ! CONFIG_CPU_FREQ */
d9460fd2 ZR	158	static int cpufreq_get_max_state(unsigned int cpu)
	159	{
	160	return 0;
	161	}
	162
	163	static int cpufreq_get_cur_state(unsigned int cpu)
	164	{
	165	return 0;
	166	}
	167
	168	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	169	{
	170	return 0;
	171	}
1da177e4	172
1da177e4 LT	173	#endif
1da177e4 LT	174
6dd7aca8	175	/* thermal cooling device callbacks */
d9460fd2 ZR	176	static int acpi_processor_max_state(struct acpi_processor *pr)
	177	{
	178	int max_state = 0;
	179
	180	/*
	181	* There exists four states according to
6dd7aca8	182	* cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
d9460fd2 ZR	183	*/
	184	max_state += cpufreq_get_max_state(pr->id);
	185	if (pr->flags.throttling)
	186	max_state += (pr->throttling.state_count -1);
	187
	188	return max_state;
	189	}
	190	static int
6503e5df MG	191	processor_get_max_state(struct thermal_cooling_device *cdev,
6503e5df MG	192	unsigned long *state)
d9460fd2 ZR	193	{
d9460fd2 ZR	194	struct acpi_device *device = cdev->devdata;
99aa3638	195	struct acpi_processor *pr;
d9460fd2	196
99aa3638 CIK	197	if (!device)
	198	return -EINVAL;
	199
	200	pr = acpi_driver_data(device);
	201	if (!pr)
d9460fd2 ZR	202	return -EINVAL;
d9460fd2 ZR	203
6503e5df MG	204	*state = acpi_processor_max_state(pr);
6503e5df MG	205	return 0;
d9460fd2 ZR	206	}
	207
	208	static int
6503e5df MG	209	processor_get_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	210	unsigned long *cur_state)
d9460fd2 ZR	211	{
d9460fd2 ZR	212	struct acpi_device *device = cdev->devdata;
99aa3638	213	struct acpi_processor *pr;
d9460fd2	214
99aa3638 CIK	215	if (!device)
	216	return -EINVAL;
	217
	218	pr = acpi_driver_data(device);
	219	if (!pr)
d9460fd2 ZR	220	return -EINVAL;
d9460fd2 ZR	221
6503e5df	222	*cur_state = cpufreq_get_cur_state(pr->id);
d9460fd2	223	if (pr->flags.throttling)
6503e5df MG	224	*cur_state += pr->throttling.state;
6503e5df MG	225	return 0;
d9460fd2 ZR	226	}
	227
	228	static int
6503e5df MG	229	processor_set_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	230	unsigned long state)
d9460fd2 ZR	231	{
d9460fd2 ZR	232	struct acpi_device *device = cdev->devdata;
99aa3638	233	struct acpi_processor *pr;
d9460fd2 ZR	234	int result = 0;
	235	int max_pstate;
	236
99aa3638 CIK	237	if (!device)
	238	return -EINVAL;
	239
	240	pr = acpi_driver_data(device);
	241	if (!pr)
d9460fd2 ZR	242	return -EINVAL;
	243
	244	max_pstate = cpufreq_get_max_state(pr->id);
	245
	246	if (state > acpi_processor_max_state(pr))
	247	return -EINVAL;
	248
	249	if (state <= max_pstate) {
	250	if (pr->flags.throttling && pr->throttling.state)
2a908002	251	result = acpi_processor_set_throttling(pr, 0, false);
d9460fd2 ZR	252	cpufreq_set_cur_state(pr->id, state);
	253	} else {
	254	cpufreq_set_cur_state(pr->id, max_pstate);
	255	result = acpi_processor_set_throttling(pr,
2a908002	256	state - max_pstate, false);
d9460fd2 ZR	257	}
	258	return result;
	259	}
	260
9c8b04be	261	const struct thermal_cooling_device_ops processor_cooling_ops = {
d9460fd2 ZR	262	.get_max_state = processor_get_max_state,
	263	.get_cur_state = processor_get_cur_state,
	264	.set_cur_state = processor_set_cur_state,
	265	};