[mirror_ubuntu-bionic-kernel.git] / drivers / acpi / processor_thermal.c

/*
 * 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
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#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 <asm/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);
static unsigned int acpi_thermal_cpufreq_is_init = 0;

#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_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
		return 0;
	return 1;
}

static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
					 unsigned long event, void *data)
{
	struct cpufreq_policy *policy = data;
	unsigned long max_freq = 0;

	if (event != CPUFREQ_ADJUST)
		goto out;

	max_freq = (
	    policy->cpuinfo.max_freq *
	    (100 - reduction_pctg(policy->cpu) * 20)
	) / 100;

	cpufreq_verify_within_limits(policy, 0, max_freq);

      out:
	return 0;
}

static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
	.notifier_call = acpi_thermal_cpufreq_notifier,
};

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)
{
	int i;

	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))
			cpufreq_update_policy(i);
	}
	return 0;
}

void acpi_thermal_cpufreq_init(void)
{
	int i;

	i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
				      CPUFREQ_POLICY_NOTIFIER);
	if (!i)
		acpi_thermal_cpufreq_is_init = 1;
}

void acpi_thermal_cpufreq_exit(void)
{
	if (acpi_thermal_cpufreq_is_init)
		cpufreq_unregister_notifier
		    (&acpi_thermal_cpufreq_notifier_block,
		     CPUFREQ_POLICY_NOTIFIER);

	acpi_thermal_cpufreq_is_init = 0;
}

#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
1da177e4 LT	1	/*
	2	* processor_thermal.c - Passive cooling submodule of the ACPI processor driver
	3	*
	4	* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
	5	* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
	6	* Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
	7	* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
	8	* - Added processor hotplug support
	9	*
	10	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License as published by
	14	* the Free Software Foundation; either version 2 of the License, or (at
	15	* your option) any later version.
	16	*
	17	* This program is distributed in the hope that it will be useful, but
	18	* WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	20	* General Public License for more details.
	21	*
	22	* You should have received a copy of the GNU General Public License along
	23	* with this program; if not, write to the Free Software Foundation, Inc.,
	24	* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
	25	*
	26	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	27	*/
	28
	29	#include <linux/kernel.h>
	30	#include <linux/module.h>
	31	#include <linux/init.h>
	32	#include <linux/cpufreq.h>
8b48463f	33	#include <linux/acpi.h>
1da177e4	34	#include <acpi/processor.h>
8b48463f	35	#include <asm/uaccess.h>
1da177e4	36
a192a958 LB	37	#define PREFIX "ACPI: "
a192a958 LB	38
1da177e4	39	#define ACPI_PROCESSOR_CLASS "processor"
1da177e4	40	#define _COMPONENT ACPI_PROCESSOR_COMPONENT
f52fd66d	41	ACPI_MODULE_NAME("processor_thermal");
1da177e4	42
1da177e4 LT	43	#ifdef CONFIG_CPU_FREQ
	44
	45	/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
	46	* offers (in most cases) voltage scaling in addition to frequency scaling, and
	47	* thus a cubic (instead of linear) reduction of energy. Also, we allow for
	48	* _any_ cpufreq driver and not only the acpi-cpufreq driver.
	49	*/
	50
d9460fd2 ZR	51	#define CPUFREQ_THERMAL_MIN_STEP 0
	52	#define CPUFREQ_THERMAL_MAX_STEP 3
	53
c938ac21	54	static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
1da177e4 LT	55	static unsigned int acpi_thermal_cpufreq_is_init = 0;
1da177e4 LT	56
2815ab92 AK	57	#define reduction_pctg(cpu) \
	58	per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
	59
	60	/*
	61	* Emulate "per package data" using per cpu data (which should really be
	62	* provided elsewhere)
	63	*
	64	* Note we can lose a CPU on cpu hotunplug, in this case we forget the state
	65	* temporarily. Fortunately that's not a big issue here (I hope)
	66	*/
	67	static int phys_package_first_cpu(int cpu)
	68	{
	69	int i;
	70	int id = topology_physical_package_id(cpu);
	71
	72	for_each_online_cpu(i)
	73	if (topology_physical_package_id(i) == id)
	74	return i;
	75	return 0;
	76	}
	77
1da177e4 LT	78	static int cpu_has_cpufreq(unsigned int cpu)
	79	{
	80	struct cpufreq_policy policy;
1cbf4c56	81	if (!acpi_thermal_cpufreq_is_init \|\| cpufreq_get_policy(&policy, cpu))
75b245b3 TR	82	return 0;
75b245b3 TR	83	return 1;
1da177e4 LT	84	}
1da177e4 LT	85
4be44fcd LB	86	static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
4be44fcd LB	87	unsigned long event, void *data)
1da177e4 LT	88	{
	89	struct cpufreq_policy *policy = data;
	90	unsigned long max_freq = 0;
	91
	92	if (event != CPUFREQ_ADJUST)
	93	goto out;
	94
c938ac21 MT	95	max_freq = (
c938ac21 MT	96	policy->cpuinfo.max_freq *
2815ab92	97	(100 - reduction_pctg(policy->cpu) * 20)
c938ac21	98	) / 100;
1da177e4 LT	99
	100	cpufreq_verify_within_limits(policy, 0, max_freq);
	101
4be44fcd	102	out:
1da177e4 LT	103	return 0;
	104	}
	105
1da177e4 LT	106	static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
	107	.notifier_call = acpi_thermal_cpufreq_notifier,
	108	};
	109
d9460fd2 ZR	110	static int cpufreq_get_max_state(unsigned int cpu)
	111	{
	112	if (!cpu_has_cpufreq(cpu))
	113	return 0;
	114
	115	return CPUFREQ_THERMAL_MAX_STEP;
	116	}
	117
	118	static int cpufreq_get_cur_state(unsigned int cpu)
	119	{
	120	if (!cpu_has_cpufreq(cpu))
	121	return 0;
	122
2815ab92	123	return reduction_pctg(cpu);
d9460fd2 ZR	124	}
	125
	126	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	127	{
2815ab92 AK	128	int i;
2815ab92 AK	129
d9460fd2 ZR	130	if (!cpu_has_cpufreq(cpu))
	131	return 0;
	132
2815ab92 AK	133	reduction_pctg(cpu) = state;
	134
	135	/*
	136	* Update all the CPUs in the same package because they all
	137	* contribute to the temperature and often share the same
	138	* frequency.
	139	*/
	140	for_each_online_cpu(i) {
	141	if (topology_physical_package_id(i) ==
	142	topology_physical_package_id(cpu))
	143	cpufreq_update_policy(i);
	144	}
d9460fd2 ZR	145	return 0;
	146	}
	147
4be44fcd LB	148	void acpi_thermal_cpufreq_init(void)
4be44fcd LB	149	{
1da177e4 LT	150	int i;
1da177e4 LT	151
4be44fcd LB	152	i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
4be44fcd LB	153	CPUFREQ_POLICY_NOTIFIER);
1da177e4 LT	154	if (!i)
	155	acpi_thermal_cpufreq_is_init = 1;
	156	}
	157
4be44fcd LB	158	void acpi_thermal_cpufreq_exit(void)
4be44fcd LB	159	{
1da177e4	160	if (acpi_thermal_cpufreq_is_init)
4be44fcd LB	161	cpufreq_unregister_notifier
	162	(&acpi_thermal_cpufreq_notifier_block,
	163	CPUFREQ_POLICY_NOTIFIER);
1da177e4 LT	164
	165	acpi_thermal_cpufreq_is_init = 0;
	166	}
	167
4be44fcd	168	#else /* ! CONFIG_CPU_FREQ */
d9460fd2 ZR	169	static int cpufreq_get_max_state(unsigned int cpu)
	170	{
	171	return 0;
	172	}
	173
	174	static int cpufreq_get_cur_state(unsigned int cpu)
	175	{
	176	return 0;
	177	}
	178
	179	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	180	{
	181	return 0;
	182	}
1da177e4	183
1da177e4 LT	184	#endif
1da177e4 LT	185
6dd7aca8	186	/* thermal cooling device callbacks */
d9460fd2 ZR	187	static int acpi_processor_max_state(struct acpi_processor *pr)
	188	{
	189	int max_state = 0;
	190
	191	/*
	192	* There exists four states according to
6dd7aca8	193	* cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
d9460fd2 ZR	194	*/
	195	max_state += cpufreq_get_max_state(pr->id);
	196	if (pr->flags.throttling)
	197	max_state += (pr->throttling.state_count -1);
	198
	199	return max_state;
	200	}
	201	static int
6503e5df MG	202	processor_get_max_state(struct thermal_cooling_device *cdev,
6503e5df MG	203	unsigned long *state)
d9460fd2 ZR	204	{
d9460fd2 ZR	205	struct acpi_device *device = cdev->devdata;
99aa3638	206	struct acpi_processor *pr;
d9460fd2	207
99aa3638 CIK	208	if (!device)
	209	return -EINVAL;
	210
	211	pr = acpi_driver_data(device);
	212	if (!pr)
d9460fd2 ZR	213	return -EINVAL;
d9460fd2 ZR	214
6503e5df MG	215	*state = acpi_processor_max_state(pr);
6503e5df MG	216	return 0;
d9460fd2 ZR	217	}
	218
	219	static int
6503e5df MG	220	processor_get_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	221	unsigned long *cur_state)
d9460fd2 ZR	222	{
d9460fd2 ZR	223	struct acpi_device *device = cdev->devdata;
99aa3638	224	struct acpi_processor *pr;
d9460fd2	225
99aa3638 CIK	226	if (!device)
	227	return -EINVAL;
	228
	229	pr = acpi_driver_data(device);
	230	if (!pr)
d9460fd2 ZR	231	return -EINVAL;
d9460fd2 ZR	232
6503e5df	233	*cur_state = cpufreq_get_cur_state(pr->id);
d9460fd2	234	if (pr->flags.throttling)
6503e5df MG	235	*cur_state += pr->throttling.state;
6503e5df MG	236	return 0;
d9460fd2 ZR	237	}
	238
	239	static int
6503e5df MG	240	processor_set_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	241	unsigned long state)
d9460fd2 ZR	242	{
d9460fd2 ZR	243	struct acpi_device *device = cdev->devdata;
99aa3638	244	struct acpi_processor *pr;
d9460fd2 ZR	245	int result = 0;
	246	int max_pstate;
	247
99aa3638 CIK	248	if (!device)
	249	return -EINVAL;
	250
	251	pr = acpi_driver_data(device);
	252	if (!pr)
d9460fd2 ZR	253	return -EINVAL;
	254
	255	max_pstate = cpufreq_get_max_state(pr->id);
	256
	257	if (state > acpi_processor_max_state(pr))
	258	return -EINVAL;
	259
	260	if (state <= max_pstate) {
	261	if (pr->flags.throttling && pr->throttling.state)
2a908002	262	result = acpi_processor_set_throttling(pr, 0, false);
d9460fd2 ZR	263	cpufreq_set_cur_state(pr->id, state);
	264	} else {
	265	cpufreq_set_cur_state(pr->id, max_pstate);
	266	result = acpi_processor_set_throttling(pr,
2a908002	267	state - max_pstate, false);
d9460fd2 ZR	268	}
	269	return result;
	270	}
	271
9c8b04be	272	const struct thermal_cooling_device_ops processor_cooling_ops = {
d9460fd2 ZR	273	.get_max_state = processor_get_max_state,
	274	.get_cur_state = processor_get_cur_state,
	275	.set_cur_state = processor_set_cur_state,
	276	};