diff options
Diffstat (limited to 'kernel/power/main.c')
-rw-r--r-- | kernel/power/main.c | 824 |
1 files changed, 824 insertions, 0 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c new file mode 100644 index 000000000..35b50823d --- /dev/null +++ b/kernel/power/main.c @@ -0,0 +1,824 @@ +/* + * 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/pm-trace.h> +#include <linux/workqueue.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> +#include <linux/suspend.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); + +/* 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_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 (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_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) +{ + 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_FS +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 ""; + } +} + +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; +} + +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; + +#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, +#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, +}; + +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_group(power_kobj, &attr_group); + if (error) + return error; + pm_print_times_init(); + return pm_autosleep_init(); +} + +core_initcall(pm_init); |