--- /dev/null
+/*
+ * kernel/power/suspend.c - Suspend to RAM and standby functionality.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/syscalls.h>
+#include <linux/gfp.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/suspend.h>
+#include <linux/syscore_ops.h>
+#include <linux/ftrace.h>
+#include <trace/events/power.h>
+#include <linux/compiler.h>
+#include <linux/moduleparam.h>
+
+#include "power.h"
+
+const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
+const char *pm_states[PM_SUSPEND_MAX];
+
+static const struct platform_suspend_ops *suspend_ops;
+static const struct platform_freeze_ops *freeze_ops;
+static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
+
+enum freeze_state __read_mostly suspend_freeze_state;
+static DEFINE_SPINLOCK(suspend_freeze_lock);
+
+void freeze_set_ops(const struct platform_freeze_ops *ops)
+{
+ lock_system_sleep();
+ freeze_ops = ops;
+ unlock_system_sleep();
+}
+
+static void freeze_begin(void)
+{
+ suspend_freeze_state = FREEZE_STATE_NONE;
+}
+
+static void freeze_enter(void)
+{
+ spin_lock_irq(&suspend_freeze_lock);
+ if (pm_wakeup_pending())
+ goto out;
+
+ suspend_freeze_state = FREEZE_STATE_ENTER;
+ spin_unlock_irq(&suspend_freeze_lock);
+
+ get_online_cpus();
+ cpuidle_resume();
+
+ /* Push all the CPUs into the idle loop. */
+ wake_up_all_idle_cpus();
+ pr_debug("PM: suspend-to-idle\n");
+ /* Make the current CPU wait so it can enter the idle loop too. */
+ wait_event(suspend_freeze_wait_head,
+ suspend_freeze_state == FREEZE_STATE_WAKE);
+ pr_debug("PM: resume from suspend-to-idle\n");
+
+ cpuidle_pause();
+ put_online_cpus();
+
+ spin_lock_irq(&suspend_freeze_lock);
+
+ out:
+ suspend_freeze_state = FREEZE_STATE_NONE;
+ spin_unlock_irq(&suspend_freeze_lock);
+}
+
+void freeze_wake(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&suspend_freeze_lock, flags);
+ if (suspend_freeze_state > FREEZE_STATE_NONE) {
+ suspend_freeze_state = FREEZE_STATE_WAKE;
+ wake_up(&suspend_freeze_wait_head);
+ }
+ spin_unlock_irqrestore(&suspend_freeze_lock, flags);
+}
+EXPORT_SYMBOL_GPL(freeze_wake);
+
+static bool valid_state(suspend_state_t state)
+{
+ /*
+ * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
+ * support and need to be valid to the low level
+ * implementation, no valid callback implies that none are valid.
+ */
+ return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
+}
+
+/*
+ * If this is set, the "mem" label always corresponds to the deepest sleep state
+ * available, the "standby" label corresponds to the second deepest sleep state
+ * available (if any), and the "freeze" label corresponds to the remaining
+ * available sleep state (if there is one).
+ */
+static bool relative_states;
+
+static int __init sleep_states_setup(char *str)
+{
+ relative_states = !strncmp(str, "1", 1);
+ pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
+ return 1;
+}
+
+__setup("relative_sleep_states=", sleep_states_setup);
+
+/**
+ * suspend_set_ops - Set the global suspend method table.
+ * @ops: Suspend operations to use.
+ */
+void suspend_set_ops(const struct platform_suspend_ops *ops)
+{
+ suspend_state_t i;
+ int j = 0;
+
+ lock_system_sleep();
+
+ suspend_ops = ops;
+ for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
+ if (valid_state(i)) {
+ pm_states[i] = pm_labels[j++];
+ } else if (!relative_states) {
+ pm_states[i] = NULL;
+ j++;
+ }
+
+ pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
+
+ unlock_system_sleep();
+}
+EXPORT_SYMBOL_GPL(suspend_set_ops);
+
+/**
+ * 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;
+}
+EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
+
+static bool sleep_state_supported(suspend_state_t state)
+{
+ return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
+}
+
+static int platform_suspend_prepare(suspend_state_t state)
+{
+ return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
+ suspend_ops->prepare() : 0;
+}
+
+static int platform_suspend_prepare_late(suspend_state_t state)
+{
+ return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
+ freeze_ops->prepare() : 0;
+}
+
+static int platform_suspend_prepare_noirq(suspend_state_t state)
+{
+ return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
+ suspend_ops->prepare_late() : 0;
+}
+
+static void platform_resume_noirq(suspend_state_t state)
+{
+ if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
+ suspend_ops->wake();
+}
+
+static void platform_resume_early(suspend_state_t state)
+{
+ if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
+ freeze_ops->restore();
+}
+
+static void platform_resume_finish(suspend_state_t state)
+{
+ if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
+ suspend_ops->finish();
+}
+
+static int platform_suspend_begin(suspend_state_t state)
+{
+ if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
+ return freeze_ops->begin();
+ else if (suspend_ops->begin)
+ return suspend_ops->begin(state);
+ else
+ return 0;
+}
+
+static void platform_resume_end(suspend_state_t state)
+{
+ if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
+ freeze_ops->end();
+ else if (suspend_ops->end)
+ suspend_ops->end();
+}
+
+static void platform_recover(suspend_state_t state)
+{
+ if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
+ suspend_ops->recover();
+}
+
+static bool platform_suspend_again(suspend_state_t state)
+{
+ return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
+ suspend_ops->suspend_again() : false;
+}
+
+#ifdef CONFIG_PM_DEBUG
+static unsigned int pm_test_delay = 5;
+module_param(pm_test_delay, uint, 0644);
+MODULE_PARM_DESC(pm_test_delay,
+ "Number of seconds to wait before resuming from suspend test");
+#endif
+
+static int suspend_test(int level)
+{
+#ifdef CONFIG_PM_DEBUG
+ if (pm_test_level == level) {
+ printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
+ pm_test_delay);
+ mdelay(pm_test_delay * 1000);
+ return 1;
+ }
+#endif /* !CONFIG_PM_DEBUG */
+ return 0;
+}
+
+/**
+ * suspend_prepare - Prepare for entering system sleep state.
+ *
+ * Common code run for every system sleep state that can be entered (except for
+ * hibernation). Run suspend notifiers, allocate the "suspend" console and
+ * freeze processes.
+ */
+static int suspend_prepare(suspend_state_t state)
+{
+ int error;
+
+ if (!sleep_state_supported(state))
+ return -EPERM;
+
+ pm_prepare_console();
+
+ error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
+ if (error)
+ goto Finish;
+
+ trace_suspend_resume(TPS("freeze_processes"), 0, true);
+ error = suspend_freeze_processes();
+ trace_suspend_resume(TPS("freeze_processes"), 0, false);
+ if (!error)
+ return 0;
+
+ suspend_stats.failed_freeze++;
+ dpm_save_failed_step(SUSPEND_FREEZE);
+ Finish:
+ pm_notifier_call_chain(PM_POST_SUSPEND);
+ pm_restore_console();
+ return error;
+}
+
+/* default implementation */
+void __weak arch_suspend_disable_irqs(void)
+{
+ local_irq_disable();
+}
+
+/* default implementation */
+void __weak arch_suspend_enable_irqs(void)
+{
+ local_irq_enable();
+}
+
+/**
+ * suspend_enter - Make the system enter the given sleep state.
+ * @state: System sleep state to enter.
+ * @wakeup: Returns information that the sleep state should not be re-entered.
+ *
+ * This function should be called after devices have been suspended.
+ */
+static int suspend_enter(suspend_state_t state, bool *wakeup)
+{
+ int error;
+
+ error = platform_suspend_prepare(state);
+ if (error)
+ goto Platform_finish;
+
+ error = dpm_suspend_late(PMSG_SUSPEND);
+ if (error) {
+ printk(KERN_ERR "PM: late suspend of devices failed\n");
+ goto Platform_finish;
+ }
+ error = platform_suspend_prepare_late(state);
+ if (error)
+ goto Devices_early_resume;
+
+ error = dpm_suspend_noirq(PMSG_SUSPEND);
+ if (error) {
+ printk(KERN_ERR "PM: noirq suspend of devices failed\n");
+ goto Platform_early_resume;
+ }
+ error = platform_suspend_prepare_noirq(state);
+ if (error)
+ goto Platform_wake;
+
+ if (suspend_test(TEST_PLATFORM))
+ goto Platform_wake;
+
+ /*
+ * PM_SUSPEND_FREEZE equals
+ * frozen processes + suspended devices + idle processors.
+ * Thus we should invoke freeze_enter() soon after
+ * all the devices are suspended.
+ */
+ if (state == PM_SUSPEND_FREEZE) {
+ trace_suspend_resume(TPS("machine_suspend"), state, true);
+ freeze_enter();
+ trace_suspend_resume(TPS("machine_suspend"), state, false);
+ goto Platform_wake;
+ }
+
+ error = disable_nonboot_cpus();
+ if (error || suspend_test(TEST_CPUS))
+ goto Enable_cpus;
+
+ arch_suspend_disable_irqs();
+ BUG_ON(!irqs_disabled());
+
+ system_state = SYSTEM_SUSPEND;
+
+ error = syscore_suspend();
+ if (!error) {
+ *wakeup = pm_wakeup_pending();
+ if (!(suspend_test(TEST_CORE) || *wakeup)) {
+ trace_suspend_resume(TPS("machine_suspend"),
+ state, true);
+ error = suspend_ops->enter(state);
+ trace_suspend_resume(TPS("machine_suspend"),
+ state, false);
+ events_check_enabled = false;
+ }
+ syscore_resume();
+ }
+
+ system_state = SYSTEM_RUNNING;
+
+ arch_suspend_enable_irqs();
+ BUG_ON(irqs_disabled());
+
+ Enable_cpus:
+ enable_nonboot_cpus();
+
+ Platform_wake:
+ platform_resume_noirq(state);
+ dpm_resume_noirq(PMSG_RESUME);
+
+ Platform_early_resume:
+ platform_resume_early(state);
+
+ Devices_early_resume:
+ dpm_resume_early(PMSG_RESUME);
+
+ Platform_finish:
+ platform_resume_finish(state);
+ return error;
+}
+
+/**
+ * suspend_devices_and_enter - Suspend devices and enter system sleep state.
+ * @state: System sleep state to enter.
+ */
+int suspend_devices_and_enter(suspend_state_t state)
+{
+ int error;
+ bool wakeup = false;
+
+ if (!sleep_state_supported(state))
+ return -ENOSYS;
+
+ error = platform_suspend_begin(state);
+ if (error)
+ goto Close;
+
+ suspend_console();
+ suspend_test_start();
+ error = dpm_suspend_start(PMSG_SUSPEND);
+ if (error) {
+ pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
+ goto Recover_platform;
+ }
+ suspend_test_finish("suspend devices");
+ if (suspend_test(TEST_DEVICES))
+ goto Recover_platform;
+
+ do {
+ error = suspend_enter(state, &wakeup);
+ } while (!error && !wakeup && platform_suspend_again(state));
+
+ Resume_devices:
+ suspend_test_start();
+ dpm_resume_end(PMSG_RESUME);
+ suspend_test_finish("resume devices");
+ trace_suspend_resume(TPS("resume_console"), state, true);
+ resume_console();
+ trace_suspend_resume(TPS("resume_console"), state, false);
+
+ Close:
+ platform_resume_end(state);
+ return error;
+
+ Recover_platform:
+ platform_recover(state);
+ goto Resume_devices;
+}
+
+/**
+ * suspend_finish - Clean up before finishing the suspend sequence.
+ *
+ * Call platform code to clean up, restart processes, and free the console that
+ * we've allocated. This routine is not called for hibernation.
+ */
+static void suspend_finish(void)
+{
+ suspend_thaw_processes();
+ pm_notifier_call_chain(PM_POST_SUSPEND);
+ pm_restore_console();
+}
+
+/**
+ * enter_state - Do common work needed to enter system sleep state.
+ * @state: System sleep state to enter.
+ *
+ * Make sure that no one else is trying to put the system into a sleep state.
+ * Fail if that's not the case. Otherwise, prepare for system suspend, make the
+ * system enter the given sleep state and clean up after wakeup.
+ */
+static int enter_state(suspend_state_t state)
+{
+ int error;
+
+ trace_suspend_resume(TPS("suspend_enter"), state, true);
+ if (state == PM_SUSPEND_FREEZE) {
+#ifdef CONFIG_PM_DEBUG
+ if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
+ pr_warning("PM: Unsupported test mode for freeze state,"
+ "please choose none/freezer/devices/platform.\n");
+ return -EAGAIN;
+ }
+#endif
+ } else if (!valid_state(state)) {
+ return -EINVAL;
+ }
+ if (!mutex_trylock(&pm_mutex))
+ return -EBUSY;
+
+ if (state == PM_SUSPEND_FREEZE)
+ freeze_begin();
+
+ trace_suspend_resume(TPS("sync_filesystems"), 0, true);
+ printk(KERN_INFO "PM: Syncing filesystems ... ");
+ sys_sync();
+ printk("done.\n");
+ trace_suspend_resume(TPS("sync_filesystems"), 0, false);
+
+ pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
+ error = suspend_prepare(state);
+ if (error)
+ goto Unlock;
+
+ if (suspend_test(TEST_FREEZER))
+ goto Finish;
+
+ trace_suspend_resume(TPS("suspend_enter"), state, false);
+ pr_debug("PM: Entering %s sleep\n", pm_states[state]);
+ pm_restrict_gfp_mask();
+ error = suspend_devices_and_enter(state);
+ pm_restore_gfp_mask();
+
+ Finish:
+ pr_debug("PM: Finishing wakeup.\n");
+ suspend_finish();
+ Unlock:
+ mutex_unlock(&pm_mutex);
+ return error;
+}
+
+/**
+ * pm_suspend - Externally visible function for suspending the system.
+ * @state: System sleep state to enter.
+ *
+ * Check if the value of @state represents one of the supported states,
+ * execute enter_state() and update system suspend statistics.
+ */
+int pm_suspend(suspend_state_t state)
+{
+ int error;
+
+ if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
+ return -EINVAL;
+
+ error = enter_state(state);
+ if (error) {
+ suspend_stats.fail++;
+ dpm_save_failed_errno(error);
+ } else {
+ suspend_stats.success++;
+ }
+ return error;
+}
+EXPORT_SYMBOL(pm_suspend);
Code Review / kvmfornfv.git / blobdiff