[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 <linux/proc_fs.h>
#include <linux/seq_file.h>

#include <asm/uaccess.h>

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

#define ACPI_PROCESSOR_COMPONENT        0x01000000
#define ACPI_PROCESSOR_CLASS            "processor"
#define ACPI_PROCESSOR_DRIVER_NAME      "ACPI Processor Driver"
#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("acpi_processor")

/* --------------------------------------------------------------------------
                                 Limit Interface
   -------------------------------------------------------------------------- */
static int acpi_processor_apply_limit(struct acpi_processor *pr)
{
	int result = 0;
	u16 px = 0;
	u16 tx = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_apply_limit");

	if (!pr)
		return_VALUE(-EINVAL);

	if (!pr->flags.limit)
		return_VALUE(-ENODEV);

	if (pr->flags.throttling) {
		if (pr->limit.user.tx > tx)
			tx = pr->limit.user.tx;
		if (pr->limit.thermal.tx > tx)
			tx = pr->limit.thermal.tx;

		result = acpi_processor_set_throttling(pr, tx);
		if (result)
			goto end;
	}

	pr->limit.state.px = px;
	pr->limit.state.tx = tx;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "Processor [%d] limit set to (P%d:T%d)\n", pr->id,
			  pr->limit.state.px, pr->limit.state.tx));

      end:
	if (result)
		ACPI_ERROR((AE_INFO, "Unable to set limit"));

	return_VALUE(result);
}

#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.
 */

static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS];
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_increase(unsigned int cpu)
{
	if (!cpu_has_cpufreq(cpu))
		return -ENODEV;

	if (cpufreq_thermal_reduction_pctg[cpu] < 60) {
		cpufreq_thermal_reduction_pctg[cpu] += 20;
		cpufreq_update_policy(cpu);
		return 0;
	}

	return -ERANGE;
}

static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
{
	if (!cpu_has_cpufreq(cpu))
		return -ENODEV;

	if (cpufreq_thermal_reduction_pctg[cpu] > 20)
		cpufreq_thermal_reduction_pctg[cpu] -= 20;
	else
		cpufreq_thermal_reduction_pctg[cpu] = 0;
	cpufreq_update_policy(cpu);
	/* We reached max freq again and can leave passive mode */
	return !cpufreq_thermal_reduction_pctg[cpu];
}

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 - cpufreq_thermal_reduction_pctg[policy->cpu])) / 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,
};

void acpi_thermal_cpufreq_init(void)
{
	int i;

	for (i = 0; i < NR_CPUS; i++)
		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 acpi_thermal_cpufreq_increase(unsigned int cpu)
{
	return -ENODEV;
}
static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
{
	return -ENODEV;
}

#endif

int acpi_processor_set_thermal_limit(acpi_handle handle, int type)
{
	int result = 0;
	struct acpi_processor *pr = NULL;
	struct acpi_device *device = NULL;
	int tx = 0, max_tx_px = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_set_thermal_limit");

	if ((type < ACPI_PROCESSOR_LIMIT_NONE)
	    || (type > ACPI_PROCESSOR_LIMIT_DECREMENT))
		return_VALUE(-EINVAL);

	result = acpi_bus_get_device(handle, &device);
	if (result)
		return_VALUE(result);

	pr = (struct acpi_processor *)acpi_driver_data(device);
	if (!pr)
		return_VALUE(-ENODEV);

	/* Thermal limits are always relative to the current Px/Tx state. */
	if (pr->flags.throttling)
		pr->limit.thermal.tx = pr->throttling.state;

	/*
	 * Our default policy is to only use throttling at the lowest
	 * performance state.
	 */

	tx = pr->limit.thermal.tx;

	switch (type) {

	case ACPI_PROCESSOR_LIMIT_NONE:
		do {
			result = acpi_thermal_cpufreq_decrease(pr->id);
		} while (!result);
		tx = 0;
		break;

	case ACPI_PROCESSOR_LIMIT_INCREMENT:
		/* if going up: P-states first, T-states later */

		result = acpi_thermal_cpufreq_increase(pr->id);
		if (!result)
			goto end;
		else if (result == -ERANGE)
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					  "At maximum performance state\n"));

		if (pr->flags.throttling) {
			if (tx == (pr->throttling.state_count - 1))
				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
						  "At maximum throttling state\n"));
			else
				tx++;
		}
		break;

	case ACPI_PROCESSOR_LIMIT_DECREMENT:
		/* if going down: T-states first, P-states later */

		if (pr->flags.throttling) {
			if (tx == 0) {
				max_tx_px = 1;
				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
						  "At minimum throttling state\n"));
			} else {
				tx--;
				goto end;
			}
		}

		result = acpi_thermal_cpufreq_decrease(pr->id);
		if (result) {
			/*
			 * We only could get -ERANGE, 1 or 0.
			 * In the first two cases we reached max freq again.
			 */
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					  "At minimum performance state\n"));
			max_tx_px = 1;
		} else
			max_tx_px = 0;

		break;
	}

      end:
	if (pr->flags.throttling) {
		pr->limit.thermal.px = 0;
		pr->limit.thermal.tx = tx;

		result = acpi_processor_apply_limit(pr);
		if (result)
			ACPI_ERROR((AE_INFO, "Unable to set thermal limit"));

		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Thermal limit now (P%d:T%d)\n",
				  pr->limit.thermal.px, pr->limit.thermal.tx));
	} else
		result = 0;
	if (max_tx_px)
		return_VALUE(1);
	else
		return_VALUE(result);
}

int acpi_processor_get_limit_info(struct acpi_processor *pr)
{
	ACPI_FUNCTION_TRACE("acpi_processor_get_limit_info");

	if (!pr)
		return_VALUE(-EINVAL);

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

	return_VALUE(0);
}

/* /proc interface */

static int acpi_processor_limit_seq_show(struct seq_file *seq, void *offset)
{
	struct acpi_processor *pr = (struct acpi_processor *)seq->private;

	ACPI_FUNCTION_TRACE("acpi_processor_limit_seq_show");

	if (!pr)
		goto end;

	if (!pr->flags.limit) {
		seq_puts(seq, "<not supported>\n");
		goto end;
	}

	seq_printf(seq, "active limit:            P%d:T%d\n"
		   "user limit:              P%d:T%d\n"
		   "thermal limit:           P%d:T%d\n",
		   pr->limit.state.px, pr->limit.state.tx,
		   pr->limit.user.px, pr->limit.user.tx,
		   pr->limit.thermal.px, pr->limit.thermal.tx);

      end:
	return_VALUE(0);
}

static int acpi_processor_limit_open_fs(struct inode *inode, struct file *file)
{
	return single_open(file, acpi_processor_limit_seq_show,
			   PDE(inode)->data);
}

static ssize_t acpi_processor_write_limit(struct file * file,
					  const char __user * buffer,
					  size_t count, loff_t * data)
{
	int result = 0;
	struct seq_file *m = (struct seq_file *)file->private_data;
	struct acpi_processor *pr = (struct acpi_processor *)m->private;
	char limit_string[25] = { '\0' };
	int px = 0;
	int tx = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_write_limit");

	if (!pr || (count > sizeof(limit_string) - 1)) {
		return_VALUE(-EINVAL);
	}

	if (copy_from_user(limit_string, buffer, count)) {
		return_VALUE(-EFAULT);
	}

	limit_string[count] = '\0';

	if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) {
		ACPI_ERROR((AE_INFO, "Invalid data format"));
		return_VALUE(-EINVAL);
	}

	if (pr->flags.throttling) {
		if ((tx < 0) || (tx > (pr->throttling.state_count - 1))) {
			ACPI_ERROR((AE_INFO, "Invalid tx"));
			return_VALUE(-EINVAL);
		}
		pr->limit.user.tx = tx;
	}

	result = acpi_processor_apply_limit(pr);

	return_VALUE(count);
}

struct file_operations acpi_processor_limit_fops = {
	.open = acpi_processor_limit_open_fs,
	.read = seq_read,
	.write = acpi_processor_write_limit,
	.llseek = seq_lseek,
	.release = single_release,
};
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>
	33	#include <linux/proc_fs.h>
	34	#include <linux/seq_file.h>
	35
	36	#include <asm/uaccess.h>
	37
	38	#include <acpi/acpi_bus.h>
	39	#include <acpi/processor.h>
	40	#include <acpi/acpi_drivers.h>
	41
	42	#define ACPI_PROCESSOR_COMPONENT 0x01000000
	43	#define ACPI_PROCESSOR_CLASS "processor"
	44	#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
	45	#define _COMPONENT ACPI_PROCESSOR_COMPONENT
4be44fcd	46	ACPI_MODULE_NAME("acpi_processor")
1da177e4 LT	47
	48	/* --------------------------------------------------------------------------
	49	Limit Interface
	50	-------------------------------------------------------------------------- */
4be44fcd	51	static int acpi_processor_apply_limit(struct acpi_processor *pr)
1da177e4	52	{
4be44fcd LB	53	int result = 0;
	54	u16 px = 0;
	55	u16 tx = 0;
1da177e4 LT	56
	57	ACPI_FUNCTION_TRACE("acpi_processor_apply_limit");
	58
	59	if (!pr)
	60	return_VALUE(-EINVAL);
	61
	62	if (!pr->flags.limit)
	63	return_VALUE(-ENODEV);
	64
	65	if (pr->flags.throttling) {
	66	if (pr->limit.user.tx > tx)
	67	tx = pr->limit.user.tx;
	68	if (pr->limit.thermal.tx > tx)
	69	tx = pr->limit.thermal.tx;
	70
	71	result = acpi_processor_set_throttling(pr, tx);
	72	if (result)
	73	goto end;
	74	}
	75
	76	pr->limit.state.px = px;
	77	pr->limit.state.tx = tx;
	78
4be44fcd LB	79	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
	80	"Processor [%d] limit set to (P%d:T%d)\n", pr->id,
	81	pr->limit.state.px, pr->limit.state.tx));
1da177e4	82
4be44fcd	83	end:
1da177e4	84	if (result)
a6fc6720	85	ACPI_ERROR((AE_INFO, "Unable to set limit"));
1da177e4 LT	86
	87	return_VALUE(result);
	88	}
	89
1da177e4 LT	90	#ifdef CONFIG_CPU_FREQ
	91
	92	/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
	93	* offers (in most cases) voltage scaling in addition to frequency scaling, and
	94	* thus a cubic (instead of linear) reduction of energy. Also, we allow for
	95	* _any_ cpufreq driver and not only the acpi-cpufreq driver.
	96	*/
	97
	98	static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS];
	99	static unsigned int acpi_thermal_cpufreq_is_init = 0;
	100
1da177e4 LT	101	static int cpu_has_cpufreq(unsigned int cpu)
	102	{
	103	struct cpufreq_policy policy;
1cbf4c56	104	if (!acpi_thermal_cpufreq_is_init \|\| cpufreq_get_policy(&policy, cpu))
75b245b3 TR	105	return 0;
75b245b3 TR	106	return 1;
1da177e4 LT	107	}
1da177e4 LT	108
1da177e4 LT	109	static int acpi_thermal_cpufreq_increase(unsigned int cpu)
	110	{
	111	if (!cpu_has_cpufreq(cpu))
	112	return -ENODEV;
	113
	114	if (cpufreq_thermal_reduction_pctg[cpu] < 60) {
	115	cpufreq_thermal_reduction_pctg[cpu] += 20;
	116	cpufreq_update_policy(cpu);
	117	return 0;
	118	}
	119
	120	return -ERANGE;
	121	}
	122
1da177e4 LT	123	static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
	124	{
	125	if (!cpu_has_cpufreq(cpu))
	126	return -ENODEV;
	127
1cbf4c56	128	if (cpufreq_thermal_reduction_pctg[cpu] > 20)
1da177e4	129	cpufreq_thermal_reduction_pctg[cpu] -= 20;
1cbf4c56 TR	130	else
	131	cpufreq_thermal_reduction_pctg[cpu] = 0;
	132	cpufreq_update_policy(cpu);
	133	/* We reached max freq again and can leave passive mode */
	134	return !cpufreq_thermal_reduction_pctg[cpu];
1da177e4 LT	135	}
1da177e4 LT	136
4be44fcd LB	137	static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
4be44fcd LB	138	unsigned long event, void *data)
1da177e4 LT	139	{
	140	struct cpufreq_policy *policy = data;
	141	unsigned long max_freq = 0;
	142
	143	if (event != CPUFREQ_ADJUST)
	144	goto out;
	145
4be44fcd LB	146	max_freq =
	147	(policy->cpuinfo.max_freq *
	148	(100 - cpufreq_thermal_reduction_pctg[policy->cpu])) / 100;
1da177e4 LT	149
	150	cpufreq_verify_within_limits(policy, 0, max_freq);
	151
4be44fcd	152	out:
1da177e4 LT	153	return 0;
	154	}
	155
1da177e4 LT	156	static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
	157	.notifier_call = acpi_thermal_cpufreq_notifier,
	158	};
	159
4be44fcd LB	160	void acpi_thermal_cpufreq_init(void)
4be44fcd LB	161	{
1da177e4 LT	162	int i;
1da177e4 LT	163
4be44fcd	164	for (i = 0; i < NR_CPUS; i++)
1da177e4 LT	165	cpufreq_thermal_reduction_pctg[i] = 0;
1da177e4 LT	166
4be44fcd LB	167	i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
4be44fcd LB	168	CPUFREQ_POLICY_NOTIFIER);
1da177e4 LT	169	if (!i)
	170	acpi_thermal_cpufreq_is_init = 1;
	171	}
	172
4be44fcd LB	173	void acpi_thermal_cpufreq_exit(void)
4be44fcd LB	174	{
1da177e4	175	if (acpi_thermal_cpufreq_is_init)
4be44fcd LB	176	cpufreq_unregister_notifier
	177	(&acpi_thermal_cpufreq_notifier_block,
	178	CPUFREQ_POLICY_NOTIFIER);
1da177e4 LT	179
	180	acpi_thermal_cpufreq_is_init = 0;
	181	}
	182
4be44fcd	183	#else /* ! CONFIG_CPU_FREQ */
1da177e4	184
4be44fcd LB	185	static int acpi_thermal_cpufreq_increase(unsigned int cpu)
	186	{
	187	return -ENODEV;
	188	}
	189	static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
	190	{
	191	return -ENODEV;
	192	}
1da177e4 LT	193
	194	#endif
	195
4be44fcd	196	int acpi_processor_set_thermal_limit(acpi_handle handle, int type)
1da177e4	197	{
4be44fcd LB	198	int result = 0;
	199	struct acpi_processor *pr = NULL;
	200	struct acpi_device *device = NULL;
1cbf4c56	201	int tx = 0, max_tx_px = 0;
1da177e4 LT	202
	203	ACPI_FUNCTION_TRACE("acpi_processor_set_thermal_limit");
	204
	205	if ((type < ACPI_PROCESSOR_LIMIT_NONE)
4be44fcd	206	\|\| (type > ACPI_PROCESSOR_LIMIT_DECREMENT))
1da177e4 LT	207	return_VALUE(-EINVAL);
	208
	209	result = acpi_bus_get_device(handle, &device);
	210	if (result)
	211	return_VALUE(result);
	212
4be44fcd	213	pr = (struct acpi_processor *)acpi_driver_data(device);
1da177e4 LT	214	if (!pr)
	215	return_VALUE(-ENODEV);
	216
	217	/* Thermal limits are always relative to the current Px/Tx state. */
	218	if (pr->flags.throttling)
	219	pr->limit.thermal.tx = pr->throttling.state;
	220
	221	/*
	222	* Our default policy is to only use throttling at the lowest
	223	* performance state.
	224	*/
	225
	226	tx = pr->limit.thermal.tx;
	227
	228	switch (type) {
	229
	230	case ACPI_PROCESSOR_LIMIT_NONE:
	231	do {
	232	result = acpi_thermal_cpufreq_decrease(pr->id);
	233	} while (!result);
	234	tx = 0;
	235	break;
	236
	237	case ACPI_PROCESSOR_LIMIT_INCREMENT:
	238	/* if going up: P-states first, T-states later */
	239
	240	result = acpi_thermal_cpufreq_increase(pr->id);
	241	if (!result)
	242	goto end;
	243	else if (result == -ERANGE)
	244	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	245	"At maximum performance state\n"));
1da177e4 LT	246
	247	if (pr->flags.throttling) {
	248	if (tx == (pr->throttling.state_count - 1))
	249	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	250	"At maximum throttling state\n"));
1da177e4 LT	251	else
	252	tx++;
	253	}
	254	break;
	255
	256	case ACPI_PROCESSOR_LIMIT_DECREMENT:
	257	/* if going down: T-states first, P-states later */
	258
	259	if (pr->flags.throttling) {
1cbf4c56 TR	260	if (tx == 0) {
1cbf4c56 TR	261	max_tx_px = 1;
1da177e4	262	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	263	"At minimum throttling state\n"));
1cbf4c56	264	} else {
1da177e4 LT	265	tx--;
	266	goto end;
	267	}
	268	}
	269
	270	result = acpi_thermal_cpufreq_decrease(pr->id);
1cbf4c56 TR	271	if (result) {
	272	/*
	273	* We only could get -ERANGE, 1 or 0.
	274	* In the first two cases we reached max freq again.
	275	*/
1da177e4	276	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	277	"At minimum performance state\n"));
1cbf4c56 TR	278	max_tx_px = 1;
	279	} else
	280	max_tx_px = 0;
1da177e4 LT	281
	282	break;
	283	}
	284
4be44fcd	285	end:
1da177e4 LT	286	if (pr->flags.throttling) {
	287	pr->limit.thermal.px = 0;
	288	pr->limit.thermal.tx = tx;
	289
	290	result = acpi_processor_apply_limit(pr);
	291	if (result)
a6fc6720	292	ACPI_ERROR((AE_INFO, "Unable to set thermal limit"));
1da177e4 LT	293
1da177e4 LT	294	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Thermal limit now (P%d:T%d)\n",
4be44fcd	295	pr->limit.thermal.px, pr->limit.thermal.tx));
1da177e4 LT	296	} else
1da177e4 LT	297	result = 0;
1cbf4c56 TR	298	if (max_tx_px)
	299	return_VALUE(1);
	300	else
	301	return_VALUE(result);
1da177e4 LT	302	}
1da177e4 LT	303
4be44fcd	304	int acpi_processor_get_limit_info(struct acpi_processor *pr)
1da177e4 LT	305	{
	306	ACPI_FUNCTION_TRACE("acpi_processor_get_limit_info");
	307
	308	if (!pr)
	309	return_VALUE(-EINVAL);
	310
	311	if (pr->flags.throttling)
	312	pr->flags.limit = 1;
	313
	314	return_VALUE(0);
	315	}
	316
1da177e4 LT	317	/* /proc interface */
	318
	319	static int acpi_processor_limit_seq_show(struct seq_file seq, void offset)
	320	{
4be44fcd	321	struct acpi_processor pr = (struct acpi_processor )seq->private;
1da177e4 LT	322
	323	ACPI_FUNCTION_TRACE("acpi_processor_limit_seq_show");
	324
	325	if (!pr)
	326	goto end;
	327
	328	if (!pr->flags.limit) {
	329	seq_puts(seq, "<not supported>\n");
	330	goto end;
	331	}
	332
	333	seq_printf(seq, "active limit: P%d:T%d\n"
4be44fcd LB	334	"user limit: P%d:T%d\n"
	335	"thermal limit: P%d:T%d\n",
	336	pr->limit.state.px, pr->limit.state.tx,
	337	pr->limit.user.px, pr->limit.user.tx,
	338	pr->limit.thermal.px, pr->limit.thermal.tx);
1da177e4	339
4be44fcd	340	end:
1da177e4 LT	341	return_VALUE(0);
	342	}
	343
	344	static int acpi_processor_limit_open_fs(struct inode inode, struct file file)
	345	{
	346	return single_open(file, acpi_processor_limit_seq_show,
4be44fcd	347	PDE(inode)->data);
1da177e4 LT	348	}
1da177e4 LT	349
757b1866 AB	350	static ssize_t acpi_processor_write_limit(struct file * file,
	351	const char __user * buffer,
	352	size_t count, loff_t * data)
1da177e4	353	{
4be44fcd LB	354	int result = 0;
	355	struct seq_file m = (struct seq_file )file->private_data;
	356	struct acpi_processor pr = (struct acpi_processor )m->private;
	357	char limit_string[25] = { '\0' };
	358	int px = 0;
	359	int tx = 0;
1da177e4 LT	360
	361	ACPI_FUNCTION_TRACE("acpi_processor_write_limit");
	362
	363	if (!pr \|\| (count > sizeof(limit_string) - 1)) {
1da177e4 LT	364	return_VALUE(-EINVAL);
	365	}
	366
	367	if (copy_from_user(limit_string, buffer, count)) {
1da177e4 LT	368	return_VALUE(-EFAULT);
	369	}
	370
	371	limit_string[count] = '\0';
	372
	373	if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) {
a6fc6720	374	ACPI_ERROR((AE_INFO, "Invalid data format"));
1da177e4 LT	375	return_VALUE(-EINVAL);
	376	}
	377
	378	if (pr->flags.throttling) {
	379	if ((tx < 0) \|\| (tx > (pr->throttling.state_count - 1))) {
a6fc6720	380	ACPI_ERROR((AE_INFO, "Invalid tx"));
1da177e4 LT	381	return_VALUE(-EINVAL);
	382	}
	383	pr->limit.user.tx = tx;
	384	}
	385
	386	result = acpi_processor_apply_limit(pr);
	387
	388	return_VALUE(count);
	389	}
	390
1da177e4	391	struct file_operations acpi_processor_limit_fops = {
4be44fcd LB	392	.open = acpi_processor_limit_open_fs,
4be44fcd LB	393	.read = seq_read,
d479e908	394	.write = acpi_processor_write_limit,
4be44fcd LB	395	.llseek = seq_lseek,
4be44fcd LB	396	.release = single_release,
1da177e4	397	};