path: root/drivers/acpi/sleep.c

/*
 * sleep.c - ACPI sleep support.
 *
 * Copyright (c) 2005 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
 * Copyright (c) 2004 David Shaohua Li <shaohua.li@intel.com>
 * Copyright (c) 2000-2003 Patrick Mochel
 * Copyright (c) 2003 Open Source Development Lab
 *
 * This file is released under the GPLv2.
 *
 */

#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/dmi.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/reboot.h>
#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/syscore_ops.h>
#include <asm/io.h>
#include <trace/events/power.h>

#include "internal.h"
#include "sleep.h"

/*
 * Some HW-full platforms do not have _S5, so they may need
 * to leverage efi power off for a shutdown.
 */
bool acpi_no_s5;
static u8 sleep_states[ACPI_S_STATE_COUNT];

static void acpi_sleep_tts_switch(u32 acpi_state)
{
	acpi_status status;

	status = acpi_execute_simple_method(NULL, "\\_TTS", acpi_state);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		/*
		 * OS can't evaluate the _TTS object correctly. Some warning
		 * message will be printed. But it won't break anything.
		 */
		printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
	}
}

static int tts_notify_reboot(struct notifier_block *this,
			unsigned long code, void *x)
{
	acpi_sleep_tts_switch(ACPI_STATE_S5);
	return NOTIFY_DONE;
}

static struct notifier_block tts_notifier = {
	.notifier_call	= tts_notify_reboot,
	.next		= NULL,
	.priority	= 0,
};

static int acpi_sleep_prepare(u32 acpi_state)
{
#ifdef CONFIG_ACPI_SLEEP
	/* do we have a wakeup address for S2 and S3? */
	if (acpi_state == ACPI_STATE_S3) {
		if (!acpi_wakeup_address)
			return -EFAULT;
		acpi_set_waking_vector(acpi_wakeup_address);

	}
	ACPI_FLUSH_CPU_CACHE();
#endif
	printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
		acpi_state);
	acpi_enable_wakeup_devices(acpi_state);
	acpi_enter_sleep_state_prep(acpi_state);
	return 0;
}

static bool acpi_sleep_state_supported(u8 sleep_state)
{
	acpi_status status;
	u8 type_a, type_b;

	status = acpi_get_sleep_type_data(sleep_state, &type_a, &type_b);
	return ACPI_SUCCESS(status) && (!acpi_gbl_reduced_hardware
		|| (acpi_gbl_FADT.sleep_control.address
			&& acpi_gbl_FADT.sleep_status.address));
}

#ifdef CONFIG_ACPI_SLEEP
static u32 acpi_target_sleep_state = ACPI_STATE_S0;

u32 acpi_target_system_state(void)
{
	return acpi_target_sleep_state;
}
EXPORT_SYMBOL_GPL(acpi_target_system_state);

static bool pwr_btn_event_pending;

/*
 * The ACPI specification wants us to save NVS memory regions during hibernation
 * and to restore them during the subsequent resume.  Windows does that also for
 * suspend to RAM.  However, it is known that this mechanism does not work on
 * all machines, so we allow the user to disable it with the help of the
 * 'acpi_sleep=nonvs' kernel command line option.
 */
static bool nvs_nosave;

void __init acpi_nvs_nosave(void)
{
	nvs_nosave = true;
}

/*
 * The ACPI specification wants us to save NVS memory regions during hibernation
 * but says nothing about saving NVS during S3.  Not all versions of Windows
 * save NVS on S3 suspend either, and it is clear that not all systems need
 * NVS to be saved at S3 time.  To improve suspend/resume time, allow the
 * user to disable saving NVS on S3 if their system does not require it, but
 * continue to save/restore NVS for S4 as specified.
 */
static bool nvs_nosave_s3;

void __init acpi_nvs_nosave_s3(void)
{
	nvs_nosave_s3 = true;
}

static int __init init_nvs_save_s3(const struct dmi_system_id *d)
{
	nvs_nosave_s3 = false;
	return 0;
}

/*
 * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
 * user to request that behavior by using the 'acpi_old_suspend_ordering'
 * kernel command line option that causes the following variable to be set.
 */
static bool old_suspend_ordering;

void __init acpi_old_suspend_ordering(void)
{
	old_suspend_ordering = true;
}

static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
{
	acpi_old_suspend_ordering();
	return 0;
}

static