[net-next-2.6.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/sysdev.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;

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 - per_cpu(cpufreq_thermal_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 per_cpu(cpufreq_thermal_reduction_pctg, cpu);
}

static int cpufreq_set_cur_state(unsigned int cpu, int state)
{
	if (!cpu_has_cpufreq(cpu))
		return 0;

	per_cpu(cpufreq_thermal_reduction_pctg, cpu) = state;
	cpufreq_update_policy(cpu);
	return 0;
}

void acpi_thermal_cpufreq_init(void)
{
	int i;

	for (i = 0; i < nr_cpu_ids; i++)
		if (cpu_present(i))
			per_cpu(cpufreq_thermal_reduction_pctg, i) = 0;

	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;
}

static int acpi_thermal_cpufreq_increase(unsigned int cpu)
{
	return -ENODEV;
}
static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
{
	return -ENODEV;
}

#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 = acpi_driver_data(device);

	if (!device || !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 = acpi_driver_data(device);

	if (!device || !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 = acpi_driver_data(device);
	int result = 0;
	int max_pstate;

	if (!device || !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;
}

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