/* * 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 _COMPONENT              ACPI_PROCESSOR_COMPONENTACPI_MODULE_NAME("processor_thermal"); /* --------------------------------------------------------------------------                                 Limit Interface   -------------------------------------------------------------------------- */static int acpi_processor_apply_limit(struct acpi_processor *pr){	int result = 0;	u16 px = 0;	u16 tx = 0;  	if (!pr)		return -EINVAL; 	if (!pr->flags.limit)		return -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)		printk(KERN_ERR PREFIX "Unable to set limit\n"); 	return 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;  	if ((type < ACPI_PROCESSOR_LIMIT_NONE)	    || (type > ACPI_PROCESSOR_LIMIT_DECREMENT))		return -EINVAL; 	result = acpi_bus_get_device(handle, &device);	if (result)		return result; 	pr = acpi_driver_data(device);	if (!pr)		return -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)			printk(KERN_ERR PREFIX "Unable to set thermal limit\n"); 		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 1;	else		return result;} int acpi_processor_get_limit_info(struct acpi_processor *pr){ 	if (!pr)		return -EINVAL; 	if (pr->flags.throttling)		pr->flags.limit = 1; 	return 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;  	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 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 = file->private_data;	struct acpi_processor *pr = m->private;	char limit_string[25] = { '\0' };	int px = 0;	int tx = 0;  	if (!pr || (count > sizeof(limit_string) - 1)) {		return -EINVAL;	} 	if (copy_from_user(limit_string, buffer, count)) {		return -EFAULT;	} 	limit_string[count] = '\0'; 	if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) {		printk(KERN_ERR PREFIX "Invalid data format\n");		return -EINVAL;	} 	if (pr->flags.throttling) {		if ((tx < 0) || (tx > (pr->throttling.state_count - 1))) {			printk(KERN_ERR PREFIX "Invalid tx\n");			return -EINVAL;		}		pr->limit.user.tx = tx;	} 	result = acpi_processor_apply_limit(pr); 	return 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,};