path: root/drivers/acpi/processor_throttling.c

/*
 * processor_throttling.c - Throttling 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/sched.h>
#include <linux/cpufreq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>

#include <asm/io.h>
#include <asm/uaccess.h>

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

#define ACPI_PROCESSOR_CLASS            "processor"
#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_throttling");

/* ignore_tpc:
 *  0 -> acpi processor driver doesn't ignore _TPC values
 *  1 -> acpi processor driver ignores _TPC values
 */
static int ignore_tpc;
module_param(ignore_tpc, int, 0644);
MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");

struct throttling_tstate {
	unsigned int cpu;		/* cpu nr */
	int target_state;		/* target T-state */
};

#define THROTTLING_PRECHANGE       (1)
#define THROTTLING_POSTCHANGE      (2)

static int acpi_processor_get_throttling(struct acpi_processor *pr);
int acpi_processor_set_throttling(struct acpi_processor *pr, int state);

static int acpi_processor_update_tsd_coord(void)
{
	int count, count_target;
	int retval = 0;
	unsigned int i, j;
	cpumask_var_t covered_cpus;
	struct acpi_processor *pr, *match_pr;
	struct acpi_tsd_package *pdomain, *match_pdomain;
	struct acpi_processor_throttling *pthrottling, *match_pthrottling;

	if (!alloc_cpumask_var(&covered_cpus, GFP_KERNEL))
		return -ENOMEM;

	/*
	 * Now that we have _TSD data from all CPUs, lets setup T-state
	 * coordination between all CPUs.
	 */
	for_each_possible_cpu(i) {
		pr = per_cpu(processors, i);
		if (!pr)
			continue;

		/* Basic validity check for domain info */
		pthrottling = &(pr->throttling);

		/*
		 * If tsd package for one cpu is invalid, the coordination
		 * among all CPUs is thought as invalid.
		 * Maybe it is ugly.
		 */
		if (!pthrottling->tsd_valid_flag) {
			retval = -EINVAL;
			break;
		}
	}
	if (retval