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// 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 "power.h" #ifdef CONFIG_PM_SLEEP void lock_system_sleep(void){	current->flags |= PF_FREEZER_SKIP;	mutex_lock(&system_transition_mutex);}EXPORT_SYMBOL_GPL(lock_system_sleep); void unlock_system_sleep(void){	/*	 * 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.	 */	current->flags &= ~PF_FREEZER_SKIP;	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(unsigned long val, int nr_to_call, int *nr_calls){	int ret; 	ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,						nr_to_call, nr_calls); 	return notifier_to_errno(ret);}int pm_notifier_call_chain(unsigned long val){	return __pm_notifier_call_chain(val, -1, 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_SUSPENDstatic 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 (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);#endif /* CONFIG_SUSPEND */ #ifdef CONFIG_PM_SLEEP_DEBUGint 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){	const char * const *s;	int level;	char *p;	int len;	int error = -EINVAL; 	p = memchr(buf, '\n', n);	len = p ? p - buf : n; 	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(); 	return error ? error : n;} power_attr(pm_test);#endif /* CONFIG_PM_SLEEP_DEBUG */ #ifdef CONFIG_DEBUG_FSstatic 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 "";	}} 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){	return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;} 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); /** * __pm_pr_dbg - Print a suspend debug message to the kernel log. * @defer: Whether or not to use printk_deferred() to print the message. * @fmt: Message format. * * The message will be emitted if enabled through the pm_debug_messages * sysfs attribute. */void __pm_pr_dbg(bool defer, const char *fmt, ...){	struct va_format vaf;	va_list args; 	if (!pm_debug_messages_on)		return; 	va_start(args, fmt); 	vaf.fmt = fmt;	vaf.va = &args; 	if (defer)		printk_deferred(KERN_DEBUG "PM: %pV", &vaf);	else		printk(KERN_DEBUG "PM: %pV", &vaf); 	va_end(args);} #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 && !strncmp(buf, "disk", len))		return PM_SUSPEND_MAX; 

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