linux-imx

/*

 * acpi_pad.c ACPI Processor Aggregator Driver

 *

 * Copyright (c) 2009, Intel Corporation.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope 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.

 *

 */

​

#include <linux/kernel.h>

#include <linux/cpumask.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/types.h>

#include <linux/kthread.h>

#include <uapi/linux/sched/types.h>

#include <linux/freezer.h>

#include <linux/cpu.h>

#include <linux/tick.h>

#include <linux/slab.h>

#include <linux/acpi.h>

#include <asm/mwait.h>

#include <xen/xen.h>

​

#define ACPI_PROCESSOR_AGGREGATOR_CLASS "acpi_pad"

#define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator"

#define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80

static DEFINE_MUTEX(isolated_cpus_lock);

static DEFINE_MUTEX(round_robin_lock);

​

static unsigned long power_saving_mwait_eax;

​

static unsigned char tsc_detected_unstable;

static unsigned char tsc_marked_unstable;

​

static void power_saving_mwait_init(void)

{

    unsigned int eax, ebx, ecx, edx;

    unsigned int highest_cstate = 0;

    unsigned int highest_subcstate = 0;

    int i;

​

    if (!boot_cpu_has(X86_FEATURE_MWAIT))

        return;

    if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)

        return;

​

    cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx);

​

    if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||

        !(ecx & CPUID5_ECX_INTERRUPT_BREAK))

        return;

​

    edx >>= MWAIT_SUBSTATE_SIZE;

    for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {

        if (edx & MWAIT_SUBSTATE_MASK) {