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-rw-r--r--kernel/power/main.c732
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 */
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