[linux-2.6-block.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;

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;
}

#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;
}

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
1da177e4 LT	60	static int cpu_has_cpufreq(unsigned int cpu)
	61	{
	62	struct cpufreq_policy policy;
1cbf4c56	63	if (!acpi_thermal_cpufreq_is_init \|\| cpufreq_get_policy(&policy, cpu))
75b245b3 TR	64	return 0;
75b245b3 TR	65	return 1;
1da177e4 LT	66	}
1da177e4 LT	67
4be44fcd LB	68	static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
4be44fcd LB	69	unsigned long event, void *data)
1da177e4 LT	70	{
	71	struct cpufreq_policy *policy = data;
	72	unsigned long max_freq = 0;
	73
	74	if (event != CPUFREQ_ADJUST)
	75	goto out;
	76
c938ac21 MT	77	max_freq = (
	78	policy->cpuinfo.max_freq *
	79	(100 - per_cpu(cpufreq_thermal_reduction_pctg, policy->cpu) * 20)
	80	) / 100;
1da177e4 LT	81
	82	cpufreq_verify_within_limits(policy, 0, max_freq);
	83
4be44fcd	84	out:
1da177e4 LT	85	return 0;
	86	}
	87
1da177e4 LT	88	static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
	89	.notifier_call = acpi_thermal_cpufreq_notifier,
	90	};
	91
d9460fd2 ZR	92	static int cpufreq_get_max_state(unsigned int cpu)
	93	{
	94	if (!cpu_has_cpufreq(cpu))
	95	return 0;
	96
	97	return CPUFREQ_THERMAL_MAX_STEP;
	98	}
	99
	100	static int cpufreq_get_cur_state(unsigned int cpu)
	101	{
	102	if (!cpu_has_cpufreq(cpu))
	103	return 0;
	104
c938ac21	105	return per_cpu(cpufreq_thermal_reduction_pctg, cpu);
d9460fd2 ZR	106	}
	107
	108	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	109	{
	110	if (!cpu_has_cpufreq(cpu))
	111	return 0;
	112
c938ac21	113	per_cpu(cpufreq_thermal_reduction_pctg, cpu) = state;
d9460fd2 ZR	114	cpufreq_update_policy(cpu);
	115	return 0;
	116	}
	117
4be44fcd LB	118	void acpi_thermal_cpufreq_init(void)
4be44fcd LB	119	{
1da177e4 LT	120	int i;
1da177e4 LT	121
c938ac21 MT	122	for (i = 0; i < nr_cpu_ids; i++)
	123	if (cpu_present(i))
	124	per_cpu(cpufreq_thermal_reduction_pctg, i) = 0;
1da177e4	125
4be44fcd LB	126	i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
4be44fcd LB	127	CPUFREQ_POLICY_NOTIFIER);
1da177e4 LT	128	if (!i)
	129	acpi_thermal_cpufreq_is_init = 1;
	130	}
	131
4be44fcd LB	132	void acpi_thermal_cpufreq_exit(void)
4be44fcd LB	133	{
1da177e4	134	if (acpi_thermal_cpufreq_is_init)
4be44fcd LB	135	cpufreq_unregister_notifier
	136	(&acpi_thermal_cpufreq_notifier_block,
	137	CPUFREQ_POLICY_NOTIFIER);
1da177e4 LT	138
	139	acpi_thermal_cpufreq_is_init = 0;
	140	}
	141
4be44fcd	142	#else /* ! CONFIG_CPU_FREQ */
d9460fd2 ZR	143	static int cpufreq_get_max_state(unsigned int cpu)
	144	{
	145	return 0;
	146	}
	147
	148	static int cpufreq_get_cur_state(unsigned int cpu)
	149	{
	150	return 0;
	151	}
	152
	153	static int cpufreq_set_cur_state(unsigned int cpu, int state)
	154	{
	155	return 0;
	156	}
1da177e4	157
1da177e4 LT	158	#endif
1da177e4 LT	159
4be44fcd	160	int acpi_processor_get_limit_info(struct acpi_processor *pr)
1da177e4	161	{
1da177e4 LT	162
1da177e4 LT	163	if (!pr)
d550d98d	164	return -EINVAL;
1da177e4 LT	165
	166	if (pr->flags.throttling)
	167	pr->flags.limit = 1;
	168
d550d98d	169	return 0;
1da177e4 LT	170	}
1da177e4 LT	171
d9460fd2 ZR	172	/* thermal coolign device callbacks */
	173	static int acpi_processor_max_state(struct acpi_processor *pr)
	174	{
	175	int max_state = 0;
	176
	177	/*
	178	* There exists four states according to
	179	* cpufreq_thermal_reduction_ptg. 0, 1, 2, 3
	180	*/
	181	max_state += cpufreq_get_max_state(pr->id);
	182	if (pr->flags.throttling)
	183	max_state += (pr->throttling.state_count -1);
	184
	185	return max_state;
	186	}
	187	static int
6503e5df MG	188	processor_get_max_state(struct thermal_cooling_device *cdev,
6503e5df MG	189	unsigned long *state)
d9460fd2 ZR	190	{
	191	struct acpi_device *device = cdev->devdata;
	192	struct acpi_processor *pr = acpi_driver_data(device);
	193
	194	if (!device \|\| !pr)
	195	return -EINVAL;
	196
6503e5df MG	197	*state = acpi_processor_max_state(pr);
6503e5df MG	198	return 0;
d9460fd2 ZR	199	}
	200
	201	static int
6503e5df MG	202	processor_get_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	203	unsigned long *cur_state)
d9460fd2 ZR	204	{
	205	struct acpi_device *device = cdev->devdata;
	206	struct acpi_processor *pr = acpi_driver_data(device);
d9460fd2 ZR	207
	208	if (!device \|\| !pr)
	209	return -EINVAL;
	210
6503e5df	211	*cur_state = cpufreq_get_cur_state(pr->id);
d9460fd2	212	if (pr->flags.throttling)
6503e5df MG	213	*cur_state += pr->throttling.state;
6503e5df MG	214	return 0;
d9460fd2 ZR	215	}
	216
	217	static int
6503e5df MG	218	processor_set_cur_state(struct thermal_cooling_device *cdev,
6503e5df MG	219	unsigned long state)
d9460fd2 ZR	220	{
	221	struct acpi_device *device = cdev->devdata;
	222	struct acpi_processor *pr = acpi_driver_data(device);
	223	int result = 0;
	224	int max_pstate;
	225
	226	if (!device \|\| !pr)
	227	return -EINVAL;
	228
	229	max_pstate = cpufreq_get_max_state(pr->id);
	230
	231	if (state > acpi_processor_max_state(pr))
	232	return -EINVAL;
	233
	234	if (state <= max_pstate) {
	235	if (pr->flags.throttling && pr->throttling.state)
2a908002	236	result = acpi_processor_set_throttling(pr, 0, false);
d9460fd2 ZR	237	cpufreq_set_cur_state(pr->id, state);
	238	} else {
	239	cpufreq_set_cur_state(pr->id, max_pstate);
	240	result = acpi_processor_set_throttling(pr,
2a908002	241	state - max_pstate, false);
d9460fd2 ZR	242	}
	243	return result;
	244	}
	245
9c8b04be	246	const struct thermal_cooling_device_ops processor_cooling_ops = {
d9460fd2 ZR	247	.get_max_state = processor_get_max_state,
	248	.get_cur_state = processor_get_cur_state,
	249	.set_cur_state = processor_set_cur_state,
	250	};