[deliverable/linux.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 <asm/uaccess.h>

#include <acpi/acpi_bus.h>
#include <acpi/processor.h>
#include <acpi/acpi_drivers.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

int acpi_processor_get_limit_info(struct acpi_processor *pr)
{

	if (!pr)
		return -EINVAL;

	if (pr->flags.throttling)
		pr->flags.limit = 1;

	return 0;
}

/* thermal coolign 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_ptg. 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>
1da177e4 LT	33
	34	#include <asm/uaccess.h>
	35
	36	#include <acpi/acpi_bus.h>
	37	#include <acpi/processor.h>
	38	#include <acpi/acpi_drivers.h>
	39
a192a958 LB	40	#define PREFIX "ACPI: "
a192a958 LB	41
1da177e4	42	#define ACPI_PROCESSOR_CLASS "processor"
1da177e4	43	#define _COMPONENT ACPI_PROCESSOR_COMPONENT
f52fd66d	44	ACPI_MODULE_NAME("processor_thermal");
1da177e4	45
1da177e4 LT	46	#ifdef CONFIG_CPU_FREQ
	47
	48	/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
	49	* offers (in most cases) voltage scaling in addition to frequency scaling, and
	50	* thus a cubic (instead of linear) reduction of energy. Also, we allow for
	51	* _any_ cpufreq driver and not only the acpi-cpufreq driver.
	52	*/
	53
d9460fd2 ZR	54	#define CPUFREQ_THERMAL_MIN_STEP 0
	55	#define CPUFREQ_THERMAL_MAX_STEP 3
	56
c938ac21	57	static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
1da177e4 LT	58	static unsigned int acpi_thermal_cpufreq_is_init = 0;
1da177e4 LT	59
2815ab92 AK	60	#define reduction_pctg(cpu) \
	61	per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
	62
	63	/*
	64	* Emulate "per package data" using per cpu data (which should really be
	65	* provided elsewhere)
	66	*
	67	* Note we can lose a CPU on cpu hotunplug, in this case we forget the state
	68	* temporarily. Fortunately that's not a big issue here (I hope)
	69	*/
	70	static int phys_package_first_cpu(int cpu)
	71	{
	72	int i;
	73	int id = topology_physical_package_id(cpu);
	74
	75	for_each_online_cpu(i)
	76	if (topology_physical_package_id(i) == id)
	77	return i;
	78	return 0;
	79	}
	80
1da177e4 LT	81	static int cpu_has_cpufreq(unsigned int cpu)
	82	{
	83	struct cpufreq_policy policy;
1cbf4c56	84	if (!acpi_thermal_cpufreq_is_init \|\| cpufreq_get_policy(&policy, cpu))
75b245b3 TR	85	return 0;
75b245b3 TR	86	return 1;
1da177e4 LT	87	}
1da177e4 LT	88
4be44fcd LB	89	static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
4be44fcd LB	90	unsigned long event, void *data)
1da177e4 LT	91	{
	92	struct cpufreq_policy *policy = data;
	93	unsigned long max_freq = 0;
	94
	95	if (event != CPUFREQ_ADJUST)
	96	goto out;
	97
c938ac21 MT	98	max_freq = (
c938ac21 MT	99	policy->cpuinfo.max_freq *
2815ab92	100	(100 - reduction_pctg(policy->cpu) * 20)
c938ac21	101	) / 100;
1da177e4 LT	102
	103	cpufreq_verify_within_limits(policy, 0, max_freq);
	104
4be44fcd	105	out:
1da177e4 LT	106	return 0;
	107	}
	108
1da177e4 LT	109	static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
	110	.notifier_call = acpi_thermal_cpufreq_notifier,
	111	};
	112
d9460fd2 ZR	113	static int cpufreq_get_max_state(unsigned int cpu)
	114	{
	115	if (!cpu_has_cpufreq(cpu))
	116	return 0;
	117
	118	return CPUFREQ_THERMAL_MAX_STEP;
	119	}
	120
	121	static int cpufreq_get_cur_state(unsigned int cpu)
	122	{
	123	if (!cpu_has_cpufreq(cpu))
	124	return 0;
	125
2815ab92	126	return reduction_pctg(cpu);
d9460fd2 ZR	127	}
	128
	129	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	130	{
2815ab92 AK	131	int i;
2815ab92 AK	132
d9460fd2 ZR	133	if (!cpu_has_cpufreq(cpu))
	134	return 0;
	135
2815ab92 AK	136	reduction_pctg(cpu) = state;
	137
	138	/*
	139	* Update all the CPUs in the same package because they all
	140	* contribute to the temperature and often share the same
	141	* frequency.
	142	*/
	143	for_each_online_cpu(i) {
	144	if (topology_physical_package_id(i) ==
	145	topology_physical_package_id(cpu))
	146	cpufreq_update_policy(i);
	147	}
d9460fd2 ZR	148	return 0;
	149	}
	150
4be44fcd LB	151	void acpi_thermal_cpufreq_init(void)
4be44fcd LB	152	{
1da177e4 LT	153	int i;
1da177e4 LT	154
4be44fcd LB	155	i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
4be44fcd LB	156	CPUFREQ_POLICY_NOTIFIER);
1da177e4 LT	157	if (!i)
	158	acpi_thermal_cpufreq_is_init = 1;
	159	}
	160
4be44fcd LB	161	void acpi_thermal_cpufreq_exit(void)
4be44fcd LB	162	{
1da177e4	163	if (acpi_thermal_cpufreq_is_init)
4be44fcd LB	164	cpufreq_unregister_notifier
	165	(&acpi_thermal_cpufreq_notifier_block,
	166	CPUFREQ_POLICY_NOTIFIER);
1da177e4 LT	167
	168	acpi_thermal_cpufreq_is_init = 0;
	169	}
	170
4be44fcd	171	#else /* ! CONFIG_CPU_FREQ */
d9460fd2 ZR	172	static int cpufreq_get_max_state(unsigned int cpu)
	173	{
	174	return 0;
	175	}
	176
	177	static int cpufreq_get_cur_state(unsigned int cpu)
	178	{
	179	return 0;
	180	}
	181
	182	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	183	{
	184	return 0;
	185	}
1da177e4	186
1da177e4 LT	187	#endif
1da177e4 LT	188
4be44fcd	189	int acpi_processor_get_limit_info(struct acpi_processor *pr)
1da177e4	190	{
1da177e4 LT	191
1da177e4 LT	192	if (!pr)
d550d98d	193	return -EINVAL;
1da177e4 LT	194
	195	if (pr->flags.throttling)
	196	pr->flags.limit = 1;
	197
d550d98d	198	return 0;
1da177e4 LT	199	}
1da177e4 LT	200
d9460fd2 ZR	201	/* thermal coolign device callbacks */
	202	static int acpi_processor_max_state(struct acpi_processor *pr)
	203	{
	204	int max_state = 0;
	205
	206	/*
	207	* There exists four states according to
	208	* cpufreq_thermal_reduction_ptg. 0, 1, 2, 3
	209	*/
	210	max_state += cpufreq_get_max_state(pr->id);
	211	if (pr->flags.throttling)
	212	max_state += (pr->throttling.state_count -1);
	213
	214	return max_state;
	215	}
	216	static int
6503e5df MG	217	processor_get_max_state(struct thermal_cooling_device *cdev,
6503e5df MG	218	unsigned long *state)
d9460fd2 ZR	219	{
d9460fd2 ZR	220	struct acpi_device *device = cdev->devdata;
99aa3638	221	struct acpi_processor *pr;
d9460fd2	222
99aa3638 CIK	223	if (!device)
	224	return -EINVAL;
	225
	226	pr = acpi_driver_data(device);
	227	if (!pr)
d9460fd2 ZR	228	return -EINVAL;
d9460fd2 ZR	229
6503e5df MG	230	*state = acpi_processor_max_state(pr);
6503e5df MG	231	return 0;
d9460fd2 ZR	232	}
	233
	234	static int
6503e5df MG	235	processor_get_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	236	unsigned long *cur_state)
d9460fd2 ZR	237	{
d9460fd2 ZR	238	struct acpi_device *device = cdev->devdata;
99aa3638	239	struct acpi_processor *pr;
d9460fd2	240
99aa3638 CIK	241	if (!device)
	242	return -EINVAL;
	243
	244	pr = acpi_driver_data(device);
	245	if (!pr)
d9460fd2 ZR	246	return -EINVAL;
d9460fd2 ZR	247
6503e5df	248	*cur_state = cpufreq_get_cur_state(pr->id);
d9460fd2	249	if (pr->flags.throttling)
6503e5df MG	250	*cur_state += pr->throttling.state;
6503e5df MG	251	return 0;
d9460fd2 ZR	252	}
	253
	254	static int
6503e5df MG	255	processor_set_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	256	unsigned long state)
d9460fd2 ZR	257	{
d9460fd2 ZR	258	struct acpi_device *device = cdev->devdata;
99aa3638	259	struct acpi_processor *pr;
d9460fd2 ZR	260	int result = 0;
	261	int max_pstate;
	262
99aa3638 CIK	263	if (!device)
	264	return -EINVAL;
	265
	266	pr = acpi_driver_data(device);
	267	if (!pr)
d9460fd2 ZR	268	return -EINVAL;
	269
	270	max_pstate = cpufreq_get_max_state(pr->id);
	271
	272	if (state > acpi_processor_max_state(pr))
	273	return -EINVAL;
	274
	275	if (state <= max_pstate) {
	276	if (pr->flags.throttling && pr->throttling.state)
2a908002	277	result = acpi_processor_set_throttling(pr, 0, false);
d9460fd2 ZR	278	cpufreq_set_cur_state(pr->id, state);
	279	} else {
	280	cpufreq_set_cur_state(pr->id, max_pstate);
	281	result = acpi_processor_set_throttling(pr,
2a908002	282	state - max_pstate, false);
d9460fd2 ZR	283	}
	284	return result;
	285	}
	286
9c8b04be	287	const struct thermal_cooling_device_ops processor_cooling_ops = {
d9460fd2 ZR	288	.get_max_state = processor_get_max_state,
	289	.get_cur_state = processor_get_cur_state,
	290	.set_cur_state = processor_set_cur_state,
	291	};