/* * kernel/power/main.c - PM subsystem core functionality. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Open Source Development Lab * * This file is released under the GPLv2 * */ #include <linux/export.h>#include <linux/kobject.h>#include <linux/string.h>#include <linux/resume-trace.h>#include <linux/workqueue.h>#include <linux/debugfs.h>#include <linux/seq_file.h> #include "power.h" DEFINE_MUTEX(pm_mutex); #ifdef CONFIG_PM_SLEEP /* 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 ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL); 	return notifier_to_errno(ret);} /* 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 (strict_strtoul(buf, 10, &val))		return -EINVAL; 	if (val > 1)		return -EINVAL; 	pm_async_enabled = val;	return n;} power_attr(pm_async); #ifdef CONFIG_PM_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_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;} static int suspend_stats_open(struct inode *inode, struct file *file){	return single_open(file, suspend_stats_show, NULL);} static const struct file_operations suspend_stats_operations = {	.open           = suspend_stats_open,	.read           = seq_read,	.llseek         = seq_lseek,	.release        = single_release,}; static int __init pm_debugfs_init(void){	debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,			NULL, NULL, &suspend_stats_operations);	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;}#else /* !CONFIG_PP_SLEEP_DEBUG */static inline void pm_print_times_init(void) {}#endif /* CONFIG_PM_SLEEP_DEBUG */ struct kobject *power_kobj; /** *	state - control system power state. * *	show() returns what states are supported, which is hard-coded to *	'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and *	'disk' (Suspend-to-Disk). * *	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	int i; 	for (i = 0; i < PM_SUSPEND_MAX; i++) {		if (pm_states[i] && valid_state(i))			s += sprintf(s,"%s ", pm_states[i]);	}#endif#ifdef CONFIG_HIBERNATION	s += sprintf(s, "%s\n", "disk");#else	if (s != buf)		/* convert the last space to a newline */		*(s-1) = '\n';#endif	return (s - buf);} static suspend_state_t decode_state(const char *buf, size_t n){#ifdef CONFIG_SUSPEND	suspend_state_t state = PM_SUSPEND_STANDBY;	const char * const *s;#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; #ifdef CONFIG_SUSPEND	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++)		if (*s && len == strlen(*s) && !strncmp(buf, *s, 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)		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;	}  out:	pm_autosleep_unlock();	return error;} power_attr(wakeup_count); #ifdef CONFIG_PM_AUTOSLEEPstatic 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", valid_state(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; 	error = pm_autosleep_set_state(state);	return error ? error : n;} power_attr(autosleep);#endif /* CONFIG_PM_AUTOSLEEP */ #ifdef CONFIG_PM_WAKELOCKSstatic 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);} 

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