diff options
Diffstat (limited to 'kernel/power/main.c')
-rw-r--r-- | kernel/power/main.c | 732 |
1 files changed, 732 insertions, 0 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c new file mode 100644 index 0000000..b8f7ce9 --- /dev/null +++ b/kernel/power/main.c @@ -0,0 +1,732 @@ +/* + * 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/module.h> +#include <linux/suspend.h> +#include <linux/kobject.h> +#include <linux/string.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/kmod.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/cpu.h> +#include <linux/resume-trace.h> +#include <linux/freezer.h> +#include <linux/vmstat.h> +#include <linux/syscalls.h> +#include <linux/ftrace.h> + +#include "power.h" + +DEFINE_MUTEX(pm_mutex); + +unsigned int pm_flags; +EXPORT_SYMBOL(pm_flags); + +#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) +{ + return (blocking_notifier_call_chain(&pm_chain_head, val, NULL) + == NOTIFY_BAD) ? -EINVAL : 0; +} + +#ifdef CONFIG_PM_DEBUG +int pm_test_level = TEST_NONE; + +static int suspend_test(int level) +{ + if (pm_test_level == level) { + printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); + mdelay(5000); + return 1; + } + return 0; +} + +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); +#else /* !CONFIG_PM_DEBUG */ +static inline int suspend_test(int level) { return 0; } +#endif /* !CONFIG_PM_DEBUG */ + +#endif /* CONFIG_PM_SLEEP */ + +#ifdef CONFIG_SUSPEND + +#ifdef CONFIG_PM_TEST_SUSPEND + +/* + * We test the system suspend code by setting an RTC wakealarm a short + * time in the future, then suspending. Suspending the devices won't + * normally take long ... some systems only need a few milliseconds. + * + * The time it takes is system-specific though, so when we test this + * during system bootup we allow a LOT of time. + */ +#define TEST_SUSPEND_SECONDS 5 + +static unsigned long suspend_test_start_time; + +static void suspend_test_start(void) +{ + /* FIXME Use better timebase than "jiffies", ideally a clocksource. + * What we want is a hardware counter that will work correctly even + * during the irqs-are-off stages of the suspend/resume cycle... + */ + suspend_test_start_time = jiffies; +} + +static void suspend_test_finish(const char *label) +{ + long nj = jiffies - suspend_test_start_time; + unsigned msec; + + msec = jiffies_to_msecs(abs(nj)); + pr_info("PM: %s took %d.%03d seconds\n", label, + msec / 1000, msec % 1000); + + /* Warning on suspend means the RTC alarm period needs to be + * larger -- the system was sooo slooowwww to suspend that the + * alarm (should have) fired before the system went to sleep! + * + * Warning on either suspend or resume also means the system + * has some performance issues. The stack dump of a WARN_ON + * is more likely to get the right attention than a printk... + */ + WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label); +} + +#else + +static void suspend_test_start(void) +{ +} + +static void suspend_test_finish(const char *label) +{ +} + +#endif + +/* This is just an arbitrary number */ +#define FREE_PAGE_NUMBER (100) + +static struct platform_suspend_ops *suspend_ops; + +/** + * suspend_set_ops - Set the global suspend method table. + * @ops: Pointer to ops structure. + */ + +void suspend_set_ops(struct platform_suspend_ops *ops) +{ + mutex_lock(&pm_mutex); + suspend_ops = ops; + mutex_unlock(&pm_mutex); +} + +/** + * suspend_valid_only_mem - generic memory-only valid callback + * + * Platform drivers that implement mem suspend only and only need + * to check for that in their .valid callback can use this instead + * of rolling their own .valid callback. + */ +int suspend_valid_only_mem(suspend_state_t state) +{ + return state == PM_SUSPEND_MEM; +} + +/** + * suspend_prepare - Do prep work before entering low-power state. + * + * This is common code that is called for each state that we're entering. + * Run suspend notifiers, allocate a console and stop all processes. + */ +static int suspend_prepare(void) +{ + int error; + unsigned int free_pages; + + if (!suspend_ops || !suspend_ops->enter) + return -EPERM; + + pm_prepare_console(); + + error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); + if (error) + goto Finish; + + error = usermodehelper_disable(); + if (error) + goto Finish; + + if (suspend_freeze_processes()) { + error = -EAGAIN; + goto Thaw; + } + + free_pages = global_page_state(NR_FREE_PAGES); + if (free_pages < FREE_PAGE_NUMBER) { + pr_debug("PM: free some memory\n"); + shrink_all_memory(FREE_PAGE_NUMBER - free_pages); + if (nr_free_pages() < FREE_PAGE_NUMBER) { + error = -ENOMEM; + printk(KERN_ERR "PM: No enough memory\n"); + } + } + if (!error) + return 0; + + Thaw: + suspend_thaw_processes(); + usermodehelper_enable(); + Finish: + pm_notifier_call_chain(PM_POST_SUSPEND); + pm_restore_console(); + return error; +} + +/* default implementation */ +void __attribute__ ((weak)) arch_suspend_disable_irqs(void) +{ + local_irq_disable(); +} + +/* default implementation */ +void __attribute__ ((weak)) arch_suspend_enable_irqs(void) +{ + local_irq_enable(); +} + +/** + * suspend_enter - enter the desired system sleep state. + * @state: state to enter + * + * This function should be called after devices have been suspended. + */ +static int suspend_enter(suspend_state_t state) +{ + int error = 0; + + device_pm_lock(); + arch_suspend_disable_irqs(); + BUG_ON(!irqs_disabled()); + + if ((error = device_power_down(PMSG_SUSPEND))) { + printk(KERN_ERR "PM: Some devices failed to power down\n"); + goto Done; + } + + if (!suspend_test(TEST_CORE)) + error = suspend_ops->enter(state); + + device_power_up(PMSG_RESUME); + Done: + arch_suspend_enable_irqs(); + BUG_ON(irqs_disabled()); + device_pm_unlock(); + return error; +} + +/** + * suspend_devices_and_enter - suspend devices and enter the desired system + * sleep state. + * @state: state to enter + */ +int suspend_devices_and_enter(suspend_state_t state) +{ + int error, ftrace_save; + + if (!suspend_ops) + return -ENOSYS; + + if (suspend_ops->begin) { + error = suspend_ops->begin(state); + if (error) + goto Close; + } + suspend_console(); + ftrace_save = __ftrace_enabled_save(); + suspend_test_start(); + error = device_suspend(PMSG_SUSPEND); + if (error) { + printk(KERN_ERR "PM: Some devices failed to suspend\n"); + goto Recover_platform; + } + suspend_test_finish("suspend devices"); + if (suspend_test(TEST_DEVICES)) + goto Recover_platform; + + if (suspend_ops->prepare) { + error = suspend_ops->prepare(); + if (error) + goto Resume_devices; + } + + if (suspend_test(TEST_PLATFORM)) + goto Finish; + + error = disable_nonboot_cpus(); + if (!error && !suspend_test(TEST_CPUS)) + suspend_enter(state); + + enable_nonboot_cpus(); + Finish: + if (suspend_ops->finish) + suspend_ops->finish(); + Resume_devices: + suspend_test_start(); + device_resume(PMSG_RESUME); + suspend_test_finish("resume devices"); + __ftrace_enabled_restore(ftrace_save); + resume_console(); + Close: + if (suspend_ops->end) + suspend_ops->end(); + return error; + + Recover_platform: + if (suspend_ops->recover) + suspend_ops->recover(); + goto Resume_devices; +} + +/** + * suspend_finish - Do final work before exiting suspend sequence. + * + * Call platform code to clean up, restart processes, and free the + * console that we've allocated. This is not called for suspend-to-disk. + */ +static void suspend_finish(void) +{ + suspend_thaw_processes(); + usermodehelper_enable(); + pm_notifier_call_chain(PM_POST_SUSPEND); + pm_restore_console(); +} + + + + +static const char * const pm_states[PM_SUSPEND_MAX] = { + [PM_SUSPEND_STANDBY] = "standby", + [PM_SUSPEND_MEM] = "mem", +}; + +static inline int valid_state(suspend_state_t state) +{ + /* All states need lowlevel support and need to be valid + * to the lowlevel implementation, no valid callback + * implies that none are valid. */ + if (!suspend_ops || !suspend_ops->valid || !suspend_ops->valid(state)) + return 0; + return 1; +} + + +/** + * enter_state - Do common work of entering low-power state. + * @state: pm_state structure for state we're entering. + * + * Make sure we're the only ones trying to enter a sleep state. Fail + * if someone has beat us to it, since we don't want anything weird to + * happen when we wake up. + * Then, do the setup for suspend, enter the state, and cleaup (after + * we've woken up). + */ +static int enter_state(suspend_state_t state) +{ + int error; + + if (!valid_state(state)) + return -ENODEV; + + if (!mutex_trylock(&pm_mutex)) + return -EBUSY; + + printk(KERN_INFO "PM: Syncing filesystems ... "); + sys_sync(); + printk("done.\n"); + + pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); + error = suspend_prepare(); + if (error) + goto Unlock; + + if (suspend_test(TEST_FREEZER)) + goto Finish; + + pr_debug("PM: Entering %s sleep\n", pm_states[state]); + error = suspend_devices_and_enter(state); + + Finish: + pr_debug("PM: Finishing wakeup.\n"); + suspend_finish(); + Unlock: + mutex_unlock(&pm_mutex); + return error; +} + + +/** + * pm_suspend - Externally visible function for suspending system. + * @state: Enumerated value of state to enter. + * + * Determine whether or not value is within range, get state + * structure, and enter (above). + */ + +int pm_suspend(suspend_state_t state) +{ + if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) + return enter_state(state); + return -EINVAL; +} + +EXPORT_SYMBOL(pm_suspend); + +#endif /* CONFIG_SUSPEND */ + +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); +#endif + + Exit: + return error ? error : n; +} + +power_attr(state); + +#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; + return n; + } + return -EINVAL; +} + +power_attr(pm_trace); +#endif /* CONFIG_PM_TRACE */ + +static struct attribute * g[] = { + &state_attr.attr, +#ifdef CONFIG_PM_TRACE + &pm_trace_attr.attr, +#endif +#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG) + &pm_test_attr.attr, +#endif + NULL, +}; + +static struct attribute_group attr_group = { + .attrs = g, +}; + + +static int __init pm_init(void) +{ + 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); + + +#ifdef CONFIG_PM_TEST_SUSPEND + +#include <linux/rtc.h> + +/* + * To test system suspend, we need a hands-off mechanism to resume the + * system. RTCs wake alarms are a common self-contained mechanism. + */ + +static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state) +{ + static char err_readtime[] __initdata = + KERN_ERR "PM: can't read %s time, err %d\n"; + static char err_wakealarm [] __initdata = + KERN_ERR "PM: can't set %s wakealarm, err %d\n"; + static char err_suspend[] __initdata = + KERN_ERR "PM: suspend test failed, error %d\n"; + static char info_test[] __initdata = + KERN_INFO "PM: test RTC wakeup from '%s' suspend\n"; + + unsigned long now; + struct rtc_wkalrm alm; + int status; + + /* this may fail if the RTC hasn't been initialized */ + status = rtc_read_time(rtc, &alm.time); + if (status < 0) { + printk(err_readtime, rtc->dev.bus_id, status); + return; + } + rtc_tm_to_time(&alm.time, &now); + + memset(&alm, 0, sizeof alm); + rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time); + alm.enabled = true; + + status = rtc_set_alarm(rtc, &alm); + if (status < 0) { + printk(err_wakealarm, rtc->dev.bus_id, status); + return; + } + + if (state == PM_SUSPEND_MEM) { + printk(info_test, pm_states[state]); + status = pm_suspend(state); + if (status == -ENODEV) + state = PM_SUSPEND_STANDBY; + } + if (state == PM_SUSPEND_STANDBY) { + printk(info_test, pm_states[state]); + status = pm_suspend(state); + } + if (status < 0) + printk(err_suspend, status); + + /* Some platforms can't detect that the alarm triggered the + * wakeup, or (accordingly) disable it after it afterwards. + * It's supposed to give oneshot behavior; cope. + */ + alm.enabled = false; + rtc_set_alarm(rtc, &alm); +} + +static int __init has_wakealarm(struct device *dev, void *name_ptr) +{ + struct rtc_device *candidate = to_rtc_device(dev); + + if (!candidate->ops->set_alarm) + return 0; + if (!device_may_wakeup(candidate->dev.parent)) + return 0; + + *(char **)name_ptr = dev->bus_id; + return 1; +} + +/* + * Kernel options like "test_suspend=mem" force suspend/resume sanity tests + * at startup time. They're normally disabled, for faster boot and because + * we can't know which states really work on this particular system. + */ +static suspend_state_t test_state __initdata = PM_SUSPEND_ON; + +static char warn_bad_state[] __initdata = + KERN_WARNING "PM: can't test '%s' suspend state\n"; + +static int __init setup_test_suspend(char *value) +{ + unsigned i; + + /* "=mem" ==> "mem" */ + value++; + for (i = 0; i < PM_SUSPEND_MAX; i++) { + if (!pm_states[i]) + continue; + if (strcmp(pm_states[i], value) != 0) + continue; + test_state = (__force suspend_state_t) i; + return 0; + } + printk(warn_bad_state, value); + return 0; +} +__setup("test_suspend", setup_test_suspend); + +static int __init test_suspend(void) +{ + static char warn_no_rtc[] __initdata = + KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n"; + + char *pony = NULL; + struct rtc_device *rtc = NULL; + + /* PM is initialized by now; is that state testable? */ + if (test_state == PM_SUSPEND_ON) + goto done; + if (!valid_state(test_state)) { + printk(warn_bad_state, pm_states[test_state]); + goto done; + } + + /* RTCs have initialized by now too ... can we use one? */ + class_find_device(rtc_class, NULL, &pony, has_wakealarm); + if (pony) + rtc = rtc_class_open(pony); + if (!rtc) { + printk(warn_no_rtc); + goto done; + } + + /* go for it */ + test_wakealarm(rtc, test_state); + rtc_class_close(rtc); +done: + return 0; +} +late_initcall(test_suspend); + +#endif /* CONFIG_PM_TEST_SUSPEND */ |