path: root/drivers/cpufreq/acpi-cpufreq.c

/*
 * acpi-cpufreq.c - ACPI Processor P-States Driver
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
 *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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/smp.h>
#include <linux/sched.h>
#include <linux/cpufreq.h>
#include <linux/compiler.h>
#include <linux/dmi.h>
#include <linux/slab.h>

#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/uaccess.h>

#include <acpi/processor.h>

#include <asm/msr.h>
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include "mperf.h"

MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
MODULE_DESCRIPTION("ACPI Processor P-States Driver");
MODULE_LICENSE("GPL");

#define PFX "acpi-cpufreq: "

enum {
	UNDEFINED_CAPABLE = 0,
	SYSTEM_INTEL_MSR_CAPABLE,
	SYSTEM_AMD_MSR_CAPABLE,
	SYSTEM_IO_CAPABLE,
};

#define INTEL_MSR_RANGE		(0xffff)
#define AMD_MSR_RANGE		(0x7)

#define MSR_K7_HWCR_CPB_DIS	(1ULL << 25)

struct acpi_cpufreq_data {
	struct acpi_processor_performance *acpi_data;
	struct cpufreq_frequency_table *freq_table;
	unsigned int resume;
	unsigned int cpu_feature;
};

static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);

/* acpi_perf_data is a pointer to percpu data. */
static struct acpi_processor_performance __percpu *acpi_perf_data;

static struct cpufreq_driver acpi_cpufreq_driver;

static unsigned int acpi_pstate_strict;
static bool boost_enabled, boost_supported;
static struct msr __percpu *msrs;

static bool boost_state(unsigned int cpu)
{
	u32 lo, hi;
	u64 msr;

	switch (boot_cpu_data.x86_vendor) {
	case X86_VENDOR_INTEL:
		rdmsr_on_cpu(cpu, MSR_IA32_MISC_ENABLE, &lo, &hi);
		msr = lo | ((u64)hi << 32);
		return !(msr & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
	case X86_VENDOR_AMD:
		rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
		msr = lo | ((u64)hi << 32);
		return !(msr & MSR_K7_HWCR_CPB_DIS);
	}
	return false;
}

static void boost_set_msrs(bool enable, const struct cpumask *cpumask)
{
	u32 cpu;
	u32 msr_addr;
	u64 msr_mask;

	switch (boot_cpu_data.x86_vendor) {
	case X86_VENDOR_INTEL:
		msr_addr = MSR_IA32_MISC_ENABLE;
		msr_mask = MSR_IA32_MISC_ENABLE_TURBO_DISABLE;
		break;
	case X86_VENDOR_AMD:
		msr_addr = MSR_K7_HWCR;
		msr_mask = MSR_K7_HWCR_CPB_DIS;
		break;
	default:
		return;
	}

	rdmsr_on_cpus(cpumask, msr_addr, msrs);

	for_each_cpu(cpu, cpumask) {
		struct msr *reg = per_cpu_ptr(msrs, cpu);
		if (enable)
			reg->q &= ~msr_mask;
		else
			reg->q |= msr_mask;
	}

	wrmsr_on_cpus(cpumask, msr_addr, msrs);
}

static ssize_t _store_boost(const char *buf, size_t count)
{
	int ret;
	unsigned long val = 0;

	if (!boost_supported)
		return -EINVAL;

	ret = kstrtoul(buf, 10, &val);
	if (ret || (val > 1))
		return -EINVAL;

	if ((val && boost_enabled) || (!val && !boost_enabled))
		return count;

	get_online_cpus();

	boost_set_msrs(val, cpu_online_mask);

	put_online_cpus();

	boost_enabled = val;
	pr_debug("Core Boosting %sabled.\n", val ? "en" : "dis");

	return count;
}

static ssize_t store_global_boost(struct kobject *kobj, struct attribute *attr,
				  const char *buf, size_t count)
{
	return _store_boost(buf, count);
}

static ssize_t show_global_boost(struct kobject *kobj,
				 struct attribute *</