/* * 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; 	mutex_lock(&pm_mutex); 	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;		} 	mutex_unlock(&pm_mutex); 	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",			"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_noirq",				suspend_stats.failed_suspend_noirq,			"failed_resume", suspend_stats.failed_resume,			"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 */ 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 ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,			   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;	int error = -EINVAL; 	p = memchr(buf, '\n', n);	len = p ? p - buf : n; 	/* First, check if we are requested to hibernate */	if (len == 4 && !strncmp(buf, "disk", len)) {		error = hibernate();  goto Exit;	} #ifdef CONFIG_SUSPEND	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {		if (*s && len == strlen(*s) && !strncmp(buf, *s, len))			break;	}	if (state < PM_SUSPEND_MAX && *s) {		error = enter_state(state);		if (error) {			suspend_stats.fail++;			dpm_save_failed_errno(error);		} else			suspend_stats.success++;	}#endif  Exit:	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) ? 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; 	if (sscanf(buf, "%u", &val) == 1) {		if (pm_save_wakeup_count(val))			return n;	}	return -EINVAL;} power_attr(wakeup_count);#endif /* CONFIG_PM_SLEEP */ #ifdef CONFIG_PM_TRACEint 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_tpm_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;		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);} static ssize_tpm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr,			 const char *buf, size_t n){	return -EINVAL;} power_attr(pm_trace_dev_match); #endif /* CONFIG_PM_TRACE */ 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_PM_DEBUG	&pm_test_attr.attr,#endif#endif	NULL,}; static struct attribute_group attr_group = {	.attrs = g,}; #ifdef CONFIG_PM_RUNTIMEstruct 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;}#elsestatic inline int pm_start_workqueue(void) { return 0; }#endif static int __init pm_init(void){	int error = pm_start_workqueue();	if (error)		return error;	hibernate_image_size_init();	hibernate_reserved_size_init();	power_kobj = kobject_create_and_add("power", NULL);	if (!power_kobj)		return -ENOMEM;	return sysfs_create_group(power_kobj, &attr_group);} core_initcall(pm_init);