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|
/*
* kernel/power/suspend.c - Suspend to RAM and standby functionality.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
* This file is released under the GPLv2.
*/
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/cpuidle.h>
#include <linux/syscalls.h>
#include <linux/gfp.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <linux/ftrace.h>
#include <trace/events/power.h>
#include <linux/compiler.h>
#include <linux/moduleparam.h>
#include "power.h"
const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
const char *pm_states[PM_SUSPEND_MAX];
static const struct platform_suspend_ops *suspend_ops;
static const struct platform_freeze_ops *freeze_ops;
static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
enum freeze_state __read_mostly suspend_freeze_state;
static DEFINE_SPINLOCK(suspend_freeze_lock);
void freeze_set_ops(const struct platform_freeze_ops *ops)
{
lock_system_sleep();
freeze_ops = ops;
unlock_system_sleep();
}
static void freeze_begin(void)
{
suspend_freeze_state = FREEZE_STATE_NONE;
}
static void freeze_enter(void)
{
spin_lock_irq(&suspend_freeze_lock);
if (pm_wakeup_pending())
goto out;
suspend_freeze_state = FREEZE_STATE_ENTER;
spin_unlock_irq(&suspend_freeze_lock);
get_online_cpus();
cpuidle_resume();
/* Push all the CPUs into the idle loop. */
wake_up_all_idle_cpus();
pr_debug("PM: suspend-to-idle\n");
/* Make the current CPU wait so it can enter the idle loop too. */
wait_event(suspend_freeze_wait_head,
suspend_freeze_state == FREEZE_STATE_WAKE);
pr_debug("PM: resume from suspend-to-idle\n");
cpuidle_pause();
put_online_cpus();
spin_lock_irq(&suspend_freeze_lock);
out:
suspend_freeze_state = FREEZE_STATE_NONE;
spin_unlock_irq(&suspend_freeze_lock);
}
void freeze_wake(void)
{
unsigned long flags;
spin_lock_irqsave(&suspend_freeze_lock, flags);
if (suspend_freeze_state > FREEZE_STATE_NONE) {
suspend_freeze_state = FREEZE_STATE_WAKE;
wake_up(&suspend_freeze_wait_head);
}
spin_unlock_irqrestore(&suspend_freeze_lock, flags);
}
EXPORT_SYMBOL_GPL(freeze_wake);
static bool valid_state(suspend_state_t state)
{
/*
* PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
* support and need to be valid to the low level
* implementation, no valid callback implies that none are valid.
*/
return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
}
/*
* If this is set, the "mem" label always corresponds to the deepest sleep state
* available, the "standby" label corresponds to the second deepest sleep state
* available (if any), and the "freeze" label corresponds to the remaining
* available sleep state (if there is one).
*/
static bool relative_states;
static int __init sleep_states_setup(char *str)
{
relative_states = !strncmp(str, "1", 1);
pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
return 1;
}
__setup("relative_sleep_states=", sleep_states_setup);
/**
* suspend_set_ops - Set the global suspend method table.
* @ops: Suspend operations to use.
*/
void suspend_set_ops(const struct platform_suspend_ops *ops)
{
suspend_state_t i;
int j = 0;
lock_system_sleep();
suspend_ops = ops;
for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
if (valid_state(i)) {
pm_states[i] = pm_labels[j++];
} else if (!relative_states) {
pm_states[i] = NULL;
j++;
}
pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
unlock_system_sleep();
}
EXPORT_SYMBOL_GPL(suspend_set_ops);
/**
* suspend_valid_only_mem - Generic memory-only valid callback.
*
* Platform drivers that implement mem suspend only and only need to check for
* that in their .valid() callback can use this instead of rolling their own
* .valid() callback.
*/
int suspend_valid_only_mem(suspend_state_t state)
{
return state == PM_SUSPEND_MEM;
}
EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
static bool sleep_state_supported(suspend_state_t state)
{
return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
}
static int platform_suspend_prepare(suspend_state_t state)
{
return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
suspend_ops->prepare() : 0;
}
static int platform_suspend_prepare_late(suspend_state_t state)
{
return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
freeze_ops->prepare() : 0;
}
static int platform_suspend_prepare_noirq(suspend_state_t state)
{
return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
suspend_ops->prepare_late() : 0;
}
static void platform_resume_noirq(suspend_state_t state)
{
if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
suspend_ops->wake();
}
static void platform_resume_early(suspend_state_t state)
{
if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
freeze_ops->restore();
}
static void platform_resume_finish(suspend_state_t state)
{
if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
suspend_ops->finish();
}
static int platform_suspend_begin(suspend_state_t state)
{
if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
return freeze_ops->begin();
else if (suspend_ops->begin)
return suspend_ops->begin(state);
else
return 0;
}
static void platform_resume_end(suspend_state_t state)
{
if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
freeze_ops->end();
else if (suspend_ops->end)
suspend_ops->end();
}
static void platform_recover(suspend_state_t state)
{
if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
suspend_ops->recover();
}
static bool platform_suspend_again(suspend_state_t state)
{
return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
suspend_ops->suspend_again() : false;
}
#ifdef CONFIG_PM_DEBUG
static unsigned int pm_test_delay = 5;
module_param(pm_test_delay, uint, 0644);
MODULE_PARM_DESC(pm_test_delay,
"Number of seconds to wait before resuming from suspend test");
#endif
static int suspend_test(int level)
{
#ifdef CONFIG_PM_DEBUG
if (pm_test_level == level) {
printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
pm_test_delay);
mdelay(pm_test_delay * 1000);
return 1;
}
#endif /* !CONFIG_PM_DEBUG */
return 0;
}
/**
* suspend_prepare - Prepare for entering system sleep state.
*
* Common code run for every system sleep state that can be entered (except for
* hibernation). Run suspend notifiers, allocate the "suspend" console and
* freeze processes.
*/
static int suspend_prepare(suspend_state_t state)
{
int error;
if (!sleep_state_supported(state))
return -EPERM;
pm_prepare_console();
error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
if (error)
goto Finish;
trace_suspend_resume(TPS("freeze_processes"), 0, true);
error = suspend_freeze_processes();
trace_suspend_resume(TPS("freeze_processes"), 0, false);
if (!error)
return 0;
suspend_stats.failed_freeze++;
dpm_save_failed_step(SUSPEND_FREEZE);
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
return error;
}
/* default implementation */
void __weak arch_suspend_disable_irqs(void)
{
local_irq_disable();
}
/* default implementation */
void __weak <
|