[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"
#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(!dev_pm_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 = dev_pm_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(int cpu)
{
	struct acpi_processor *pr = per_cpu(processors, cpu);
	int ret;

	ret = dev_pm_qos_add_request(get_cpu_device(cpu),
				     &pr->thermal_req, DEV_PM_QOS_MAX_FREQUENCY,
				     INT_MAX);
	if (ret < 0) {
		pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu,
		       ret);
		return;
	}
}

void acpi_thermal_cpufreq_exit(int cpu)
{
	struct acpi_processor *pr = per_cpu(processors, cpu);

	dev_pm_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
	108	if (unlikely(!dev_pm_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 = dev_pm_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	}
2815ab92	124	}
d9460fd2 ZR	125	return 0;
	126	}
	127
d15ce412	128	void acpi_thermal_cpufreq_init(int cpu)
4be44fcd	129	{
d15ce412 VK	130	struct acpi_processor *pr = per_cpu(processors, cpu);
	131	int ret;
	132
	133	ret = dev_pm_qos_add_request(get_cpu_device(cpu),
	134	&pr->thermal_req, DEV_PM_QOS_MAX_FREQUENCY,
	135	INT_MAX);
	136	if (ret < 0) {
	137	pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu,
	138	ret);
	139	return;
	140	}
1da177e4 LT	141	}
1da177e4 LT	142
d15ce412	143	void acpi_thermal_cpufreq_exit(int cpu)
4be44fcd	144	{
d15ce412	145	struct acpi_processor *pr = per_cpu(processors, cpu);
1da177e4	146
d15ce412	147	dev_pm_qos_remove_request(&pr->thermal_req);
1da177e4	148	}
4be44fcd	149	#else /* ! CONFIG_CPU_FREQ */
d9460fd2 ZR	150	static int cpufreq_get_max_state(unsigned int cpu)
	151	{
	152	return 0;
	153	}
	154
	155	static int cpufreq_get_cur_state(unsigned int cpu)
	156	{
	157	return 0;
	158	}
	159
	160	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	161	{
	162	return 0;
	163	}
1da177e4	164
1da177e4 LT	165	#endif
1da177e4 LT	166
6dd7aca8	167	/* thermal cooling device callbacks */
d9460fd2 ZR	168	static int acpi_processor_max_state(struct acpi_processor *pr)
	169	{
	170	int max_state = 0;
	171
	172	/*
	173	* There exists four states according to
6dd7aca8	174	* cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
d9460fd2 ZR	175	*/
	176	max_state += cpufreq_get_max_state(pr->id);
	177	if (pr->flags.throttling)
	178	max_state += (pr->throttling.state_count -1);
	179
	180	return max_state;
	181	}
	182	static int
6503e5df MG	183	processor_get_max_state(struct thermal_cooling_device *cdev,
6503e5df MG	184	unsigned long *state)
d9460fd2 ZR	185	{
d9460fd2 ZR	186	struct acpi_device *device = cdev->devdata;
99aa3638	187	struct acpi_processor *pr;
d9460fd2	188
99aa3638 CIK	189	if (!device)
	190	return -EINVAL;
	191
	192	pr = acpi_driver_data(device);
	193	if (!pr)
d9460fd2 ZR	194	return -EINVAL;
d9460fd2 ZR	195
6503e5df MG	196	*state = acpi_processor_max_state(pr);
6503e5df MG	197	return 0;
d9460fd2 ZR	198	}
	199
	200	static int
6503e5df MG	201	processor_get_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	202	unsigned long *cur_state)
d9460fd2 ZR	203	{
d9460fd2 ZR	204	struct acpi_device *device = cdev->devdata;
99aa3638	205	struct acpi_processor *pr;
d9460fd2	206
99aa3638 CIK	207	if (!device)
	208	return -EINVAL;
	209
	210	pr = acpi_driver_data(device);
	211	if (!pr)
d9460fd2 ZR	212	return -EINVAL;
d9460fd2 ZR	213
6503e5df	214	*cur_state = cpufreq_get_cur_state(pr->id);
d9460fd2	215	if (pr->flags.throttling)
6503e5df MG	216	*cur_state += pr->throttling.state;
6503e5df MG	217	return 0;
d9460fd2 ZR	218	}
	219
	220	static int
6503e5df MG	221	processor_set_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	222	unsigned long state)
d9460fd2 ZR	223	{
d9460fd2 ZR	224	struct acpi_device *device = cdev->devdata;
99aa3638	225	struct acpi_processor *pr;
d9460fd2 ZR	226	int result = 0;
	227	int max_pstate;
	228
99aa3638 CIK	229	if (!device)
	230	return -EINVAL;
	231
	232	pr = acpi_driver_data(device);
	233	if (!pr)
d9460fd2 ZR	234	return -EINVAL;
	235
	236	max_pstate = cpufreq_get_max_state(pr->id);
	237
	238	if (state > acpi_processor_max_state(pr))
	239	return -EINVAL;
	240
	241	if (state <= max_pstate) {
	242	if (pr->flags.throttling && pr->throttling.state)
2a908002	243	result = acpi_processor_set_throttling(pr, 0, false);
d9460fd2 ZR	244	cpufreq_set_cur_state(pr->id, state);
	245	} else {
	246	cpufreq_set_cur_state(pr->id, max_pstate);
	247	result = acpi_processor_set_throttling(pr,
2a908002	248	state - max_pstate, false);
d9460fd2 ZR	249	}
	250	return result;
	251	}
	252
9c8b04be	253	const struct thermal_cooling_device_ops processor_cooling_ops = {
d9460fd2 ZR	254	.get_max_state = processor_get_max_state,
	255	.get_cur_state = processor_get_cur_state,
	256	.set_cur_state = processor_set_cur_state,
	257	};