linux/kernel/power/main.c
Peter Zijlstra f5d39b0208 freezer,sched: Rewrite core freezer logic
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

	freezer_do_not_count();
	schedule();
	freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

	TASK_FREEZABLE	-> TASK_FROZEN
	__TASK_STOPPED	-> TASK_FROZEN
	__TASK_TRACED	-> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
2022-09-07 21:53:50 +02:00

941 lines
22 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* kernel/power/main.c - PM subsystem core functionality.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
*/
#include <linux/export.h>
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/pm-trace.h>
#include <linux/workqueue.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/suspend.h>
#include <linux/syscalls.h>
#include <linux/pm_runtime.h>
#include "power.h"
#ifdef CONFIG_PM_SLEEP
unsigned int lock_system_sleep(void)
{
unsigned int flags = current->flags;
current->flags |= PF_NOFREEZE;
mutex_lock(&system_transition_mutex);
return flags;
}
EXPORT_SYMBOL_GPL(lock_system_sleep);
void unlock_system_sleep(unsigned int flags)
{
/*
* Don't use freezer_count() because we don't want the call to
* try_to_freeze() here.
*
* Reason:
* Fundamentally, we just don't need it, because freezing condition
* doesn't come into effect until we release the
* system_transition_mutex lock, since the freezer always works with
* system_transition_mutex held.
*
* More importantly, in the case of hibernation,
* unlock_system_sleep() gets called in snapshot_read() and
* snapshot_write() when the freezing condition is still in effect.
* Which means, if we use try_to_freeze() here, it would make them
* enter the refrigerator, thus causing hibernation to lockup.
*/
if (!(flags & PF_NOFREEZE))
current->flags &= ~PF_NOFREEZE;
mutex_unlock(&system_transition_mutex);
}
EXPORT_SYMBOL_GPL(unlock_system_sleep);
void ksys_sync_helper(void)
{
ktime_t start;
long elapsed_msecs;
start = ktime_get();
ksys_sync();
elapsed_msecs = ktime_to_ms(ktime_sub(ktime_get(), start));
pr_info("Filesystems sync: %ld.%03ld seconds\n",
elapsed_msecs / MSEC_PER_SEC, elapsed_msecs % MSEC_PER_SEC);
}
EXPORT_SYMBOL_GPL(ksys_sync_helper);
/* Routines for PM-transition notifications */
static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
int register_pm_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&pm_chain_head, nb);
}
EXPORT_SYMBOL_GPL(register_pm_notifier);
int unregister_pm_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&pm_chain_head, nb);
}
EXPORT_SYMBOL_GPL(unregister_pm_notifier);
int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long val_down)
{
int ret;
ret = blocking_notifier_call_chain_robust(&pm_chain_head, val_up, val_down, NULL);
return notifier_to_errno(ret);
}
int pm_notifier_call_chain(unsigned long val)
{
return blocking_notifier_call_chain(&pm_chain_head, val, NULL);
}
/* If set, devices may be suspended and resumed asynchronously. */
int pm_async_enabled = 1;
static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", pm_async_enabled);
}
static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long val;
if (kstrtoul(buf, 10, &val))
return -EINVAL;
if (val > 1)
return -EINVAL;
pm_async_enabled = val;
return n;
}
power_attr(pm_async);
#ifdef CONFIG_SUSPEND
static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
char *s = buf;
suspend_state_t i;
for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) {
if (i >= PM_SUSPEND_MEM && cxl_mem_active())
continue;
if (mem_sleep_states[i]) {
const char *label = mem_sleep_states[i];
if (mem_sleep_current == i)
s += sprintf(s, "[%s] ", label);
else
s += sprintf(s, "%s ", label);
}
}
/* Convert the last space to a newline if needed. */
if (s != buf)
*(s-1) = '\n';
return (s - buf);
}
static suspend_state_t decode_suspend_state(const char *buf, size_t n)
{
suspend_state_t state;
char *p;
int len;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
const char *label = mem_sleep_states[state];
if (label && len == strlen(label) && !strncmp(buf, label, len))
return state;
}
return PM_SUSPEND_ON;
}
static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
suspend_state_t state;
int error;
error = pm_autosleep_lock();
if (error)
return error;
if (pm_autosleep_state() > PM_SUSPEND_ON) {
error = -EBUSY;
goto out;
}
state = decode_suspend_state(buf, n);
if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
mem_sleep_current = state;
else
error = -EINVAL;
out:
pm_autosleep_unlock();
return error ? error : n;
}
power_attr(mem_sleep);
/*
* sync_on_suspend: invoke ksys_sync_helper() before suspend.
*
* show() returns whether ksys_sync_helper() is invoked before suspend.
* store() accepts 0 or 1. 0 disables ksys_sync_helper() and 1 enables it.
*/
bool sync_on_suspend_enabled = !IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC);
static ssize_t sync_on_suspend_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", sync_on_suspend_enabled);
}
static ssize_t sync_on_suspend_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long val;
if (kstrtoul(buf, 10, &val))
return -EINVAL;
if (val > 1)
return -EINVAL;
sync_on_suspend_enabled = !!val;
return n;
}
power_attr(sync_on_suspend);
#endif /* CONFIG_SUSPEND */
#ifdef CONFIG_PM_SLEEP_DEBUG
int pm_test_level = TEST_NONE;
static const char * const pm_tests[__TEST_AFTER_LAST] = {
[TEST_NONE] = "none",
[TEST_CORE] = "core",
[TEST_CPUS] = "processors",
[TEST_PLATFORM] = "platform",
[TEST_DEVICES] = "devices",
[TEST_FREEZER] = "freezer",
};
static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
char *s = buf;
int level;
for (level = TEST_FIRST; level <= TEST_MAX; level++)
if (pm_tests[level]) {
if (level == pm_test_level)
s += sprintf(s, "[%s] ", pm_tests[level]);
else
s += sprintf(s, "%s ", pm_tests[level]);
}
if (s != buf)
/* convert the last space to a newline */
*(s-1) = '\n';
return (s - buf);
}
static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned int sleep_flags;
const char * const *s;
int error = -EINVAL;
int level;
char *p;
int len;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
sleep_flags = lock_system_sleep();
level = TEST_FIRST;
for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
pm_test_level = level;
error = 0;
break;
}
unlock_system_sleep(sleep_flags);
return error ? error : n;
}
power_attr(pm_test);
#endif /* CONFIG_PM_SLEEP_DEBUG */
static char *suspend_step_name(enum suspend_stat_step step)
{
switch (step) {
case SUSPEND_FREEZE:
return "freeze";
case SUSPEND_PREPARE:
return "prepare";
case SUSPEND_SUSPEND:
return "suspend";
case SUSPEND_SUSPEND_NOIRQ:
return "suspend_noirq";
case SUSPEND_RESUME_NOIRQ:
return "resume_noirq";
case SUSPEND_RESUME:
return "resume";
default:
return "";
}
}
#define suspend_attr(_name) \
static ssize_t _name##_show(struct kobject *kobj, \
struct kobj_attribute *attr, char *buf) \
{ \
return sprintf(buf, "%d\n", suspend_stats._name); \
} \
static struct kobj_attribute _name = __ATTR_RO(_name)
suspend_attr(success);
suspend_attr(fail);
suspend_attr(failed_freeze);
suspend_attr(failed_prepare);
suspend_attr(failed_suspend);
suspend_attr(failed_suspend_late);
suspend_attr(failed_suspend_noirq);
suspend_attr(failed_resume);
suspend_attr(failed_resume_early);
suspend_attr(failed_resume_noirq);
static ssize_t last_failed_dev_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
int index;
char *last_failed_dev = NULL;
index = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
index %= REC_FAILED_NUM;
last_failed_dev = suspend_stats.failed_devs[index];
return sprintf(buf, "%s\n", last_failed_dev);
}
static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
static ssize_t last_failed_errno_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
int index;
int last_failed_errno;
index = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
index %= REC_FAILED_NUM;
last_failed_errno = suspend_stats.errno[index];
return sprintf(buf, "%d\n", last_failed_errno);
}
static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
static ssize_t last_failed_step_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
int index;
enum suspend_stat_step step;
char *last_failed_step = NULL;
index = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
index %= REC_FAILED_NUM;
step = suspend_stats.failed_steps[index];
last_failed_step = suspend_step_name(step);
return sprintf(buf, "%s\n", last_failed_step);
}
static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
static struct attribute *suspend_attrs[] = {
&success.attr,
&fail.attr,
&failed_freeze.attr,
&failed_prepare.attr,
&failed_suspend.attr,
&failed_suspend_late.attr,
&failed_suspend_noirq.attr,
&failed_resume.attr,
&failed_resume_early.attr,
&failed_resume_noirq.attr,
&last_failed_dev.attr,
&last_failed_errno.attr,
&last_failed_step.attr,
NULL,
};
static const struct attribute_group suspend_attr_group = {
.name = "suspend_stats",
.attrs = suspend_attrs,
};
#ifdef CONFIG_DEBUG_FS
static int suspend_stats_show(struct seq_file *s, void *unused)
{
int i, index, last_dev, last_errno, last_step;
last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
last_dev %= REC_FAILED_NUM;
last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
last_errno %= REC_FAILED_NUM;
last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
last_step %= REC_FAILED_NUM;
seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
"%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
"success", suspend_stats.success,
"fail", suspend_stats.fail,
"failed_freeze", suspend_stats.failed_freeze,
"failed_prepare", suspend_stats.failed_prepare,
"failed_suspend", suspend_stats.failed_suspend,
"failed_suspend_late",
suspend_stats.failed_suspend_late,
"failed_suspend_noirq",
suspend_stats.failed_suspend_noirq,
"failed_resume", suspend_stats.failed_resume,
"failed_resume_early",
suspend_stats.failed_resume_early,
"failed_resume_noirq",
suspend_stats.failed_resume_noirq);
seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
suspend_stats.failed_devs[last_dev]);
for (i = 1; i < REC_FAILED_NUM; i++) {
index = last_dev + REC_FAILED_NUM - i;
index %= REC_FAILED_NUM;
seq_printf(s, "\t\t\t%-s\n",
suspend_stats.failed_devs[index]);
}
seq_printf(s, " last_failed_errno:\t%-d\n",
suspend_stats.errno[last_errno]);
for (i = 1; i < REC_FAILED_NUM; i++) {
index = last_errno + REC_FAILED_NUM - i;
index %= REC_FAILED_NUM;
seq_printf(s, "\t\t\t%-d\n",
suspend_stats.errno[index]);
}
seq_printf(s, " last_failed_step:\t%-s\n",
suspend_step_name(
suspend_stats.failed_steps[last_step]));
for (i = 1; i < REC_FAILED_NUM; i++) {
index = last_step + REC_FAILED_NUM - i;
index %= REC_FAILED_NUM;
seq_printf(s, "\t\t\t%-s\n",
suspend_step_name(
suspend_stats.failed_steps[index]));
}
return 0;
}
DEFINE_SHOW_ATTRIBUTE(suspend_stats);
static int __init pm_debugfs_init(void)
{
debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
NULL, NULL, &suspend_stats_fops);
return 0;
}
late_initcall(pm_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_PM_SLEEP_DEBUG
/*
* pm_print_times: print time taken by devices to suspend and resume.
*
* show() returns whether printing of suspend and resume times is enabled.
* store() accepts 0 or 1. 0 disables printing and 1 enables it.
*/
bool pm_print_times_enabled;
static ssize_t pm_print_times_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", pm_print_times_enabled);
}
static ssize_t pm_print_times_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long val;
if (kstrtoul(buf, 10, &val))
return -EINVAL;
if (val > 1)
return -EINVAL;
pm_print_times_enabled = !!val;
return n;
}
power_attr(pm_print_times);
static inline void pm_print_times_init(void)
{
pm_print_times_enabled = !!initcall_debug;
}
static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
if (!pm_wakeup_irq())
return -ENODATA;
return sprintf(buf, "%u\n", pm_wakeup_irq());
}
power_attr_ro(pm_wakeup_irq);
bool pm_debug_messages_on __read_mostly;
static ssize_t pm_debug_messages_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", pm_debug_messages_on);
}
static ssize_t pm_debug_messages_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long val;
if (kstrtoul(buf, 10, &val))
return -EINVAL;
if (val > 1)
return -EINVAL;
pm_debug_messages_on = !!val;
return n;
}
power_attr(pm_debug_messages);
static int __init pm_debug_messages_setup(char *str)
{
pm_debug_messages_on = true;
return 1;
}
__setup("pm_debug_messages", pm_debug_messages_setup);
#else /* !CONFIG_PM_SLEEP_DEBUG */
static inline void pm_print_times_init(void) {}
#endif /* CONFIG_PM_SLEEP_DEBUG */
struct kobject *power_kobj;
/*
* state - control system sleep states.
*
* show() returns available sleep state labels, which may be "mem", "standby",
* "freeze" and "disk" (hibernation).
* See Documentation/admin-guide/pm/sleep-states.rst for a description of
* what they mean.
*
* store() accepts one of those strings, translates it into the proper
* enumerated value, and initiates a suspend transition.
*/
static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
char *s = buf;
#ifdef CONFIG_SUSPEND
suspend_state_t i;
for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
if (pm_states[i])
s += sprintf(s,"%s ", pm_states[i]);
#endif
if (hibernation_available())
s += sprintf(s, "disk ");
if (s != buf)
/* convert the last space to a newline */
*(s-1) = '\n';
return (s - buf);
}
static suspend_state_t decode_state(const char *buf, size_t n)
{
#ifdef CONFIG_SUSPEND
suspend_state_t state;
#endif
char *p;
int len;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
/* Check hibernation first. */
if (len == 4 && str_has_prefix(buf, "disk"))
return PM_SUSPEND_MAX;
#ifdef CONFIG_SUSPEND
for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
const char *label = pm_states[state];
if (label && len == strlen(label) && !strncmp(buf, label, len))
return state;
}
#endif
return PM_SUSPEND_ON;
}
static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
suspend_state_t state;
int error;
error = pm_autosleep_lock();
if (error)
return error;
if (pm_autosleep_state() > PM_SUSPEND_ON) {
error = -EBUSY;
goto out;
}
state = decode_state(buf, n);
if (state < PM_SUSPEND_MAX) {
if (state == PM_SUSPEND_MEM)
state = mem_sleep_current;
error = pm_suspend(state);
} else if (state == PM_SUSPEND_MAX) {
error = hibernate();
} else {
error = -EINVAL;
}
out:
pm_autosleep_unlock();
return error ? error : n;
}
power_attr(state);
#ifdef CONFIG_PM_SLEEP
/*
* The 'wakeup_count' attribute, along with the functions defined in
* drivers/base/power/wakeup.c, provides a means by which wakeup events can be
* handled in a non-racy way.
*
* If a wakeup event occurs when the system is in a sleep state, it simply is
* woken up. In turn, if an event that would wake the system up from a sleep
* state occurs when it is undergoing a transition to that sleep state, the
* transition should be aborted. Moreover, if such an event occurs when the
* system is in the working state, an attempt to start a transition to the
* given sleep state should fail during certain period after the detection of
* the event. Using the 'state' attribute alone is not sufficient to satisfy
* these requirements, because a wakeup event may occur exactly when 'state'
* is being written to and may be delivered to user space right before it is
* frozen, so the event will remain only partially processed until the system is
* woken up by another event. In particular, it won't cause the transition to
* a sleep state to be aborted.
*
* This difficulty may be overcome if user space uses 'wakeup_count' before
* writing to 'state'. It first should read from 'wakeup_count' and store
* the read value. Then, after carrying out its own preparations for the system
* transition to a sleep state, it should write the stored value to
* 'wakeup_count'. If that fails, at least one wakeup event has occurred since
* 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
* is allowed to write to 'state', but the transition will be aborted if there
* are any wakeup events detected after 'wakeup_count' was written to.
*/
static ssize_t wakeup_count_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
unsigned int val;
return pm_get_wakeup_count(&val, true) ?
sprintf(buf, "%u\n", val) : -EINTR;
}
static ssize_t wakeup_count_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned int val;
int error;
error = pm_autosleep_lock();
if (error)
return error;
if (pm_autosleep_state() > PM_SUSPEND_ON) {
error = -EBUSY;
goto out;
}
error = -EINVAL;
if (sscanf(buf, "%u", &val) == 1) {
if (pm_save_wakeup_count(val))
error = n;
else
pm_print_active_wakeup_sources();
}
out:
pm_autosleep_unlock();
return error;
}
power_attr(wakeup_count);
#ifdef CONFIG_PM_AUTOSLEEP
static ssize_t autosleep_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
suspend_state_t state = pm_autosleep_state();
if (state == PM_SUSPEND_ON)
return sprintf(buf, "off\n");
#ifdef CONFIG_SUSPEND
if (state < PM_SUSPEND_MAX)
return sprintf(buf, "%s\n", pm_states[state] ?
pm_states[state] : "error");
#endif
#ifdef CONFIG_HIBERNATION
return sprintf(buf, "disk\n");
#else
return sprintf(buf, "error");
#endif
}
static ssize_t autosleep_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
suspend_state_t state = decode_state(buf, n);
int error;
if (state == PM_SUSPEND_ON
&& strcmp(buf, "off") && strcmp(buf, "off\n"))
return -EINVAL;
if (state == PM_SUSPEND_MEM)
state = mem_sleep_current;
error = pm_autosleep_set_state(state);
return error ? error : n;
}
power_attr(autosleep);
#endif /* CONFIG_PM_AUTOSLEEP */
#ifdef CONFIG_PM_WAKELOCKS
static ssize_t wake_lock_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
return pm_show_wakelocks(buf, true);
}
static ssize_t wake_lock_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
int error = pm_wake_lock(buf);
return error ? error : n;
}
power_attr(wake_lock);
static ssize_t wake_unlock_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
return pm_show_wakelocks(buf, false);
}
static ssize_t wake_unlock_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
int error = pm_wake_unlock(buf);
return error ? error : n;
}
power_attr(wake_unlock);
#endif /* CONFIG_PM_WAKELOCKS */
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_PM_TRACE
int pm_trace_enabled;
static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", pm_trace_enabled);
}
static ssize_t
pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
int val;
if (sscanf(buf, "%d", &val) == 1) {
pm_trace_enabled = !!val;
if (pm_trace_enabled) {
pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
"PM: Correct system time has to be restored manually after resume.\n");
}
return n;
}
return -EINVAL;
}
power_attr(pm_trace);
static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
return show_trace_dev_match(buf, PAGE_SIZE);
}
power_attr_ro(pm_trace_dev_match);
#endif /* CONFIG_PM_TRACE */
#ifdef CONFIG_FREEZER
static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%u\n", freeze_timeout_msecs);
}
static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long val;
if (kstrtoul(buf, 10, &val))
return -EINVAL;
freeze_timeout_msecs = val;
return n;
}
power_attr(pm_freeze_timeout);
#endif /* CONFIG_FREEZER*/
static struct attribute * g[] = {
&state_attr.attr,
#ifdef CONFIG_PM_TRACE
&pm_trace_attr.attr,
&pm_trace_dev_match_attr.attr,
#endif
#ifdef CONFIG_PM_SLEEP
&pm_async_attr.attr,
&wakeup_count_attr.attr,
#ifdef CONFIG_SUSPEND
&mem_sleep_attr.attr,
&sync_on_suspend_attr.attr,
#endif
#ifdef CONFIG_PM_AUTOSLEEP
&autosleep_attr.attr,
#endif
#ifdef CONFIG_PM_WAKELOCKS
&wake_lock_attr.attr,
&wake_unlock_attr.attr,
#endif
#ifdef CONFIG_PM_SLEEP_DEBUG
&pm_test_attr.attr,
&pm_print_times_attr.attr,
&pm_wakeup_irq_attr.attr,
&pm_debug_messages_attr.attr,
#endif
#endif
#ifdef CONFIG_FREEZER
&pm_freeze_timeout_attr.attr,
#endif
NULL,
};
static const struct attribute_group attr_group = {
.attrs = g,
};
static const struct attribute_group *attr_groups[] = {
&attr_group,
#ifdef CONFIG_PM_SLEEP
&suspend_attr_group,
#endif
NULL,
};
struct workqueue_struct *pm_wq;
EXPORT_SYMBOL_GPL(pm_wq);
static int __init pm_start_workqueue(void)
{
pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
return pm_wq ? 0 : -ENOMEM;
}
static int __init pm_init(void)
{
int error = pm_start_workqueue();
if (error)
return error;
hibernate_image_size_init();
hibernate_reserved_size_init();
pm_states_init();
power_kobj = kobject_create_and_add("power", NULL);
if (!power_kobj)
return -ENOMEM;
error = sysfs_create_groups(power_kobj, attr_groups);
if (error)
return error;
pm_print_times_init();
return pm_autosleep_init();
}
core_initcall(pm_init);