// SPDX-License-Identifier: GPL-2.0-or-later
/*
* processor_idle - idle state submodule to 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, 2005 Dominik Brodowski <linux@brodo.de>
* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
* - Added processor hotplug support
* Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
* - Added support for C3 on SMP
*/
#define pr_fmt(fmt) "ACPI: " fmt
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/sched.h> /* need_resched() */
#include <linux/tick.h>
#include <linux/cpuidle.h>
#include <linux/cpu.h>
#include <acpi/processor.h>
/*
* Include the apic definitions for x86 to have the APIC timer related defines
* available also for UP (on SMP it gets magically included via linux/smp.h).
* asm/acpi.h is not an option, as it would require more include magic. Also
* creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
*/
#ifdef CONFIG_X86
#include <asm/apic.h>
#endif
#define ACPI_PROCESSOR_CLASS "processor"
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_idle");
#define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
module_param(max_cstate, uint, 0000);
static unsigned int nocst __read_mostly;
module_param(nocst, uint, 0000);
static int bm_check_disable __read_mostly;
module_param(bm_check_disable, uint, 0000);
static unsigned int latency_factor __read_mostly = 2;
module_param(latency_factor, uint, 0644);
static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
struct cpuidle_driver acpi_idle_driver = {
.name = "acpi_idle",
.owner = THIS_MODULE,
};
#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
static
DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
static int disabled_by_idle_boot_param(void)
{
return boot_option_idle_override == IDLE_POLL ||
boot_option_idle_override == IDLE_HALT;
}
/*
* IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
* For now disable this. Probably a bug somewhere else.
*
* To skip this limit, boot/load with a large max_cstate limit.
*/
static int set_max_cstate(const struct dmi_system_id *id)
{
if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
return 0;
pr_notice("%s detected - limiting to C%ld max_cstate."
" Override with \"processor.max_cstate=%d\"\n", id->ident,
(long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
max_cstate = (long)id->driver_data;
return 0;
}
static const struct