// 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 #include #include #include #include #include #include #include #include #include #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_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 (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) { 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 */ 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);