v4.19.13 snapshot.
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
new file mode 100644
index 0000000..beb85c3
--- /dev/null
+++ b/drivers/base/power/runtime.c
@@ -0,0 +1,1715 @@
+/*
+ * drivers/base/power/runtime.c - Helper functions for device runtime PM
+ *
+ * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/sched/mm.h>
+#include <linux/export.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_wakeirq.h>
+#include <trace/events/rpm.h>
+
+#include "../base.h"
+#include "power.h"
+
+typedef int (*pm_callback_t)(struct device *);
+
+static pm_callback_t __rpm_get_callback(struct device *dev, size_t cb_offset)
+{
+ pm_callback_t cb;
+ const struct dev_pm_ops *ops;
+
+ if (dev->pm_domain)
+ ops = &dev->pm_domain->ops;
+ else if (dev->type && dev->type->pm)
+ ops = dev->type->pm;
+ else if (dev->class && dev->class->pm)
+ ops = dev->class->pm;
+ else if (dev->bus && dev->bus->pm)
+ ops = dev->bus->pm;
+ else
+ ops = NULL;
+
+ if (ops)
+ cb = *(pm_callback_t *)((void *)ops + cb_offset);
+ else
+ cb = NULL;
+
+ if (!cb && dev->driver && dev->driver->pm)
+ cb = *(pm_callback_t *)((void *)dev->driver->pm + cb_offset);
+
+ return cb;
+}
+
+#define RPM_GET_CALLBACK(dev, callback) \
+ __rpm_get_callback(dev, offsetof(struct dev_pm_ops, callback))
+
+static int rpm_resume(struct device *dev, int rpmflags);
+static int rpm_suspend(struct device *dev, int rpmflags);
+
+/**
+ * update_pm_runtime_accounting - Update the time accounting of power states
+ * @dev: Device to update the accounting for
+ *
+ * In order to be able to have time accounting of the various power states
+ * (as used by programs such as PowerTOP to show the effectiveness of runtime
+ * PM), we need to track the time spent in each state.
+ * update_pm_runtime_accounting must be called each time before the
+ * runtime_status field is updated, to account the time in the old state
+ * correctly.
+ */
+void update_pm_runtime_accounting(struct device *dev)
+{
+ unsigned long now = jiffies;
+ unsigned long delta;
+
+ delta = now - dev->power.accounting_timestamp;
+
+ dev->power.accounting_timestamp = now;
+
+ if (dev->power.disable_depth > 0)
+ return;
+
+ if (dev->power.runtime_status == RPM_SUSPENDED)
+ dev->power.suspended_jiffies += delta;
+ else
+ dev->power.active_jiffies += delta;
+}
+
+static void __update_runtime_status(struct device *dev, enum rpm_status status)
+{
+ update_pm_runtime_accounting(dev);
+ dev->power.runtime_status = status;
+}
+
+/**
+ * pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
+ * @dev: Device to handle.
+ */
+static void pm_runtime_deactivate_timer(struct device *dev)
+{
+ if (dev->power.timer_expires > 0) {
+ del_timer(&dev->power.suspend_timer);
+ dev->power.timer_expires = 0;
+ }
+}
+
+/**
+ * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
+ * @dev: Device to handle.
+ */
+static void pm_runtime_cancel_pending(struct device *dev)
+{
+ pm_runtime_deactivate_timer(dev);
+ /*
+ * In case there's a request pending, make sure its work function will
+ * return without doing anything.
+ */
+ dev->power.request = RPM_REQ_NONE;
+}
+
+/*
+ * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time.
+ * @dev: Device to handle.
+ *
+ * Compute the autosuspend-delay expiration time based on the device's
+ * power.last_busy time. If the delay has already expired or is disabled
+ * (negative) or the power.use_autosuspend flag isn't set, return 0.
+ * Otherwise return the expiration time in jiffies (adjusted to be nonzero).
+ *
+ * This function may be called either with or without dev->power.lock held.
+ * Either way it can be racy, since power.last_busy may be updated at any time.
+ */
+unsigned long pm_runtime_autosuspend_expiration(struct device *dev)
+{
+ int autosuspend_delay;
+ long elapsed;
+ unsigned long last_busy;
+ unsigned long expires = 0;
+
+ if (!dev->power.use_autosuspend)
+ goto out;
+
+ autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay);
+ if (autosuspend_delay < 0)
+ goto out;
+
+ last_busy = READ_ONCE(dev->power.last_busy);
+ elapsed = jiffies - last_busy;
+ if (elapsed < 0)
+ goto out; /* jiffies has wrapped around. */
+
+ /*
+ * If the autosuspend_delay is >= 1 second, align the timer by rounding
+ * up to the nearest second.
+ */
+ expires = last_busy + msecs_to_jiffies(autosuspend_delay);
+ if (autosuspend_delay >= 1000)
+ expires = round_jiffies(expires);
+ expires += !expires;
+ if (elapsed >= expires - last_busy)
+ expires = 0; /* Already expired. */
+
+ out:
+ return expires;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
+
+static int dev_memalloc_noio(struct device *dev, void *data)
+{
+ return dev->power.memalloc_noio;
+}
+
+/*
+ * pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag.
+ * @dev: Device to handle.
+ * @enable: True for setting the flag and False for clearing the flag.
+ *
+ * Set the flag for all devices in the path from the device to the
+ * root device in the device tree if @enable is true, otherwise clear
+ * the flag for devices in the path whose siblings don't set the flag.
+ *
+ * The function should only be called by block device, or network
+ * device driver for solving the deadlock problem during runtime
+ * resume/suspend:
+ *
+ * If memory allocation with GFP_KERNEL is called inside runtime
+ * resume/suspend callback of any one of its ancestors(or the
+ * block device itself), the deadlock may be triggered inside the
+ * memory allocation since it might not complete until the block
+ * device becomes active and the involed page I/O finishes. The
+ * situation is pointed out first by Alan Stern. Network device
+ * are involved in iSCSI kind of situation.
+ *
+ * The lock of dev_hotplug_mutex is held in the function for handling
+ * hotplug race because pm_runtime_set_memalloc_noio() may be called
+ * in async probe().
+ *
+ * The function should be called between device_add() and device_del()
+ * on the affected device(block/network device).
+ */
+void pm_runtime_set_memalloc_noio(struct device *dev, bool enable)
+{
+ static DEFINE_MUTEX(dev_hotplug_mutex);
+
+ mutex_lock(&dev_hotplug_mutex);
+ for (;;) {
+ bool enabled;
+
+ /* hold power lock since bitfield is not SMP-safe. */
+ spin_lock_irq(&dev->power.lock);
+ enabled = dev->power.memalloc_noio;
+ dev->power.memalloc_noio = enable;
+ spin_unlock_irq(&dev->power.lock);
+
+ /*
+ * not need to enable ancestors any more if the device
+ * has been enabled.
+ */
+ if (enabled && enable)
+ break;
+
+ dev = dev->parent;
+
+ /*
+ * clear flag of the parent device only if all the
+ * children don't set the flag because ancestor's
+ * flag was set by any one of the descendants.
+ */
+ if (!dev || (!enable &&
+ device_for_each_child(dev, NULL,
+ dev_memalloc_noio)))
+ break;
+ }
+ mutex_unlock(&dev_hotplug_mutex);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio);
+
+/**
+ * rpm_check_suspend_allowed - Test whether a device may be suspended.
+ * @dev: Device to test.
+ */
+static int rpm_check_suspend_allowed(struct device *dev)
+{
+ int retval = 0;
+
+ if (dev->power.runtime_error)
+ retval = -EINVAL;
+ else if (dev->power.disable_depth > 0)
+ retval = -EACCES;
+ else if (atomic_read(&dev->power.usage_count) > 0)
+ retval = -EAGAIN;
+ else if (!dev->power.ignore_children &&
+ atomic_read(&dev->power.child_count))
+ retval = -EBUSY;
+
+ /* Pending resume requests take precedence over suspends. */
+ else if ((dev->power.deferred_resume
+ && dev->power.runtime_status == RPM_SUSPENDING)
+ || (dev->power.request_pending
+ && dev->power.request == RPM_REQ_RESUME))
+ retval = -EAGAIN;
+ else if (__dev_pm_qos_read_value(dev) == 0)
+ retval = -EPERM;
+ else if (dev->power.runtime_status == RPM_SUSPENDED)
+ retval = 1;
+
+ return retval;
+}
+
+static int rpm_get_suppliers(struct device *dev)
+{
+ struct device_link *link;
+
+ list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
+ int retval;
+
+ if (!(link->flags & DL_FLAG_PM_RUNTIME))
+ continue;
+
+ if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND ||
+ link->rpm_active)
+ continue;
+
+ retval = pm_runtime_get_sync(link->supplier);
+ /* Ignore suppliers with disabled runtime PM. */
+ if (retval < 0 && retval != -EACCES) {
+ pm_runtime_put_noidle(link->supplier);
+ return retval;
+ }
+ link->rpm_active = true;
+ }
+ return 0;
+}
+
+static void rpm_put_suppliers(struct device *dev)
+{
+ struct device_link *link;
+
+ list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
+ if (link->rpm_active &&
+ READ_ONCE(link->status) != DL_STATE_SUPPLIER_UNBIND) {
+ pm_runtime_put(link->supplier);
+ link->rpm_active = false;
+ }
+}
+
+/**
+ * __rpm_callback - Run a given runtime PM callback for a given device.
+ * @cb: Runtime PM callback to run.
+ * @dev: Device to run the callback for.
+ */
+static int __rpm_callback(int (*cb)(struct device *), struct device *dev)
+ __releases(&dev->power.lock) __acquires(&dev->power.lock)
+{
+ int retval, idx;
+ bool use_links = dev->power.links_count > 0;
+
+ if (dev->power.irq_safe) {
+ spin_unlock(&dev->power.lock);
+ } else {
+ spin_unlock_irq(&dev->power.lock);
+
+ /*
+ * Resume suppliers if necessary.
+ *
+ * The device's runtime PM status cannot change until this
+ * routine returns, so it is safe to read the status outside of
+ * the lock.
+ */
+ if (use_links && dev->power.runtime_status == RPM_RESUMING) {
+ idx = device_links_read_lock();
+
+ retval = rpm_get_suppliers(dev);
+ if (retval)
+ goto fail;
+
+ device_links_read_unlock(idx);
+ }
+ }
+
+ retval = cb(dev);
+
+ if (dev->power.irq_safe) {
+ spin_lock(&dev->power.lock);
+ } else {
+ /*
+ * If the device is suspending and the callback has returned
+ * success, drop the usage counters of the suppliers that have
+ * been reference counted on its resume.
+ *
+ * Do that if resume fails too.
+ */
+ if (use_links
+ && ((dev->power.runtime_status == RPM_SUSPENDING && !retval)
+ || (dev->power.runtime_status == RPM_RESUMING && retval))) {
+ idx = device_links_read_lock();
+
+ fail:
+ rpm_put_suppliers(dev);
+
+ device_links_read_unlock(idx);
+ }
+
+ spin_lock_irq(&dev->power.lock);
+ }
+
+ return retval;
+}
+
+/**
+ * rpm_idle - Notify device bus type if the device can be suspended.
+ * @dev: Device to notify the bus type about.
+ * @rpmflags: Flag bits.
+ *
+ * Check if the device's runtime PM status allows it to be suspended. If
+ * another idle notification has been started earlier, return immediately. If
+ * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
+ * run the ->runtime_idle() callback directly. If the ->runtime_idle callback
+ * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static int rpm_idle(struct device *dev, int rpmflags)
+{
+ int (*callback)(struct device *);
+ int retval;
+
+ trace_rpm_idle_rcuidle(dev, rpmflags);
+ retval = rpm_check_suspend_allowed(dev);
+ if (retval < 0)
+ ; /* Conditions are wrong. */
+
+ /* Idle notifications are allowed only in the RPM_ACTIVE state. */
+ else if (dev->power.runtime_status != RPM_ACTIVE)
+ retval = -EAGAIN;
+
+ /*
+ * Any pending request other than an idle notification takes
+ * precedence over us, except that the timer may be running.
+ */
+ else if (dev->power.request_pending &&
+ dev->power.request > RPM_REQ_IDLE)
+ retval = -EAGAIN;
+
+ /* Act as though RPM_NOWAIT is always set. */
+ else if (dev->power.idle_notification)
+ retval = -EINPROGRESS;
+ if (retval)
+ goto out;
+
+ /* Pending requests need to be canceled. */
+ dev->power.request = RPM_REQ_NONE;
+
+ if (dev->power.no_callbacks)
+ goto out;
+
+ /* Carry out an asynchronous or a synchronous idle notification. */
+ if (rpmflags & RPM_ASYNC) {
+ dev->power.request = RPM_REQ_IDLE;
+ if (!dev->power.request_pending) {
+ dev->power.request_pending = true;
+ queue_work(pm_wq, &dev->power.work);
+ }
+ trace_rpm_return_int_rcuidle(dev, _THIS_IP_, 0);
+ return 0;
+ }
+
+ dev->power.idle_notification = true;
+
+ callback = RPM_GET_CALLBACK(dev, runtime_idle);
+
+ if (callback)
+ retval = __rpm_callback(callback, dev);
+
+ dev->power.idle_notification = false;
+ wake_up_all(&dev->power.wait_queue);
+
+ out:
+ trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
+ return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO);
+}
+
+/**
+ * rpm_callback - Run a given runtime PM callback for a given device.
+ * @cb: Runtime PM callback to run.
+ * @dev: Device to run the callback for.
+ */
+static int rpm_callback(int (*cb)(struct device *), struct device *dev)
+{
+ int retval;
+
+ if (!cb)
+ return -ENOSYS;
+
+ if (dev->power.memalloc_noio) {
+ unsigned int noio_flag;
+
+ /*
+ * Deadlock might be caused if memory allocation with
+ * GFP_KERNEL happens inside runtime_suspend and
+ * runtime_resume callbacks of one block device's
+ * ancestor or the block device itself. Network
+ * device might be thought as part of iSCSI block
+ * device, so network device and its ancestor should
+ * be marked as memalloc_noio too.
+ */
+ noio_flag = memalloc_noio_save();
+ retval = __rpm_callback(cb, dev);
+ memalloc_noio_restore(noio_flag);
+ } else {
+ retval = __rpm_callback(cb, dev);
+ }
+
+ dev->power.runtime_error = retval;
+ return retval != -EACCES ? retval : -EIO;
+}
+
+/**
+ * rpm_suspend - Carry out runtime suspend of given device.
+ * @dev: Device to suspend.
+ * @rpmflags: Flag bits.
+ *
+ * Check if the device's runtime PM status allows it to be suspended.
+ * Cancel a pending idle notification, autosuspend or suspend. If
+ * another suspend has been started earlier, either return immediately
+ * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC
+ * flags. If the RPM_ASYNC flag is set then queue a suspend request;
+ * otherwise run the ->runtime_suspend() callback directly. When
+ * ->runtime_suspend succeeded, if a deferred resume was requested while
+ * the callback was running then carry it out, otherwise send an idle
+ * notification for its parent (if the suspend succeeded and both
+ * ignore_children of parent->power and irq_safe of dev->power are not set).
+ * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO
+ * flag is set and the next autosuspend-delay expiration time is in the
+ * future, schedule another autosuspend attempt.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static int rpm_suspend(struct device *dev, int rpmflags)
+ __releases(&dev->power.lock) __acquires(&dev->power.lock)
+{
+ int (*callback)(struct device *);
+ struct device *parent = NULL;
+ int retval;
+
+ trace_rpm_suspend_rcuidle(dev, rpmflags);
+
+ repeat:
+ retval = rpm_check_suspend_allowed(dev);
+
+ if (retval < 0)
+ ; /* Conditions are wrong. */
+
+ /* Synchronous suspends are not allowed in the RPM_RESUMING state. */
+ else if (dev->power.runtime_status == RPM_RESUMING &&
+ !(rpmflags & RPM_ASYNC))
+ retval = -EAGAIN;
+ if (retval)
+ goto out;
+
+ /* If the autosuspend_delay time hasn't expired yet, reschedule. */
+ if ((rpmflags & RPM_AUTO)
+ && dev->power.runtime_status != RPM_SUSPENDING) {
+ unsigned long expires = pm_runtime_autosuspend_expiration(dev);
+
+ if (expires != 0) {
+ /* Pending requests need to be canceled. */
+ dev->power.request = RPM_REQ_NONE;
+
+ /*
+ * Optimization: If the timer is already running and is
+ * set to expire at or before the autosuspend delay,
+ * avoid the overhead of resetting it. Just let it
+ * expire; pm_suspend_timer_fn() will take care of the
+ * rest.
+ */
+ if (!(dev->power.timer_expires && time_before_eq(
+ dev->power.timer_expires, expires))) {
+ dev->power.timer_expires = expires;
+ mod_timer(&dev->power.suspend_timer, expires);
+ }
+ dev->power.timer_autosuspends = 1;
+ goto out;
+ }
+ }
+
+ /* Other scheduled or pending requests need to be canceled. */
+ pm_runtime_cancel_pending(dev);
+
+ if (dev->power.runtime_status == RPM_SUSPENDING) {
+ DEFINE_WAIT(wait);
+
+ if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
+ retval = -EINPROGRESS;
+ goto out;
+ }
+
+ if (dev->power.irq_safe) {
+ spin_unlock(&dev->power.lock);
+
+ cpu_relax();
+
+ spin_lock(&dev->power.lock);
+ goto repeat;
+ }
+
+ /* Wait for the other suspend running in parallel with us. */
+ for (;;) {
+ prepare_to_wait(&dev->power.wait_queue, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (dev->power.runtime_status != RPM_SUSPENDING)
+ break;
+
+ spin_unlock_irq(&dev->power.lock);
+
+ schedule();
+
+ spin_lock_irq(&dev->power.lock);
+ }
+ finish_wait(&dev->power.wait_queue, &wait);
+ goto repeat;
+ }
+
+ if (dev->power.no_callbacks)
+ goto no_callback; /* Assume success. */
+
+ /* Carry out an asynchronous or a synchronous suspend. */
+ if (rpmflags & RPM_ASYNC) {
+ dev->power.request = (rpmflags & RPM_AUTO) ?
+ RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
+ if (!dev->power.request_pending) {
+ dev->power.request_pending = true;
+ queue_work(pm_wq, &dev->power.work);
+ }
+ goto out;
+ }
+
+ __update_runtime_status(dev, RPM_SUSPENDING);
+
+ callback = RPM_GET_CALLBACK(dev, runtime_suspend);
+
+ dev_pm_enable_wake_irq_check(dev, true);
+ retval = rpm_callback(callback, dev);
+ if (retval)
+ goto fail;
+
+ no_callback:
+ __update_runtime_status(dev, RPM_SUSPENDED);
+ pm_runtime_deactivate_timer(dev);
+
+ if (dev->parent) {
+ parent = dev->parent;
+ atomic_add_unless(&parent->power.child_count, -1, 0);
+ }
+ wake_up_all(&dev->power.wait_queue);
+
+ if (dev->power.deferred_resume) {
+ dev->power.deferred_resume = false;
+ rpm_resume(dev, 0);
+ retval = -EAGAIN;
+ goto out;
+ }
+
+ /* Maybe the parent is now able to suspend. */
+ if (parent && !parent->power.ignore_children && !dev->power.irq_safe) {
+ spin_unlock(&dev->power.lock);
+
+ spin_lock(&parent->power.lock);
+ rpm_idle(parent, RPM_ASYNC);
+ spin_unlock(&parent->power.lock);
+
+ spin_lock(&dev->power.lock);
+ }
+
+ out:
+ trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
+
+ return retval;
+
+ fail:
+ dev_pm_disable_wake_irq_check(dev);
+ __update_runtime_status(dev, RPM_ACTIVE);
+ dev->power.deferred_resume = false;
+ wake_up_all(&dev->power.wait_queue);
+
+ if (retval == -EAGAIN || retval == -EBUSY) {
+ dev->power.runtime_error = 0;
+
+ /*
+ * If the callback routine failed an autosuspend, and
+ * if the last_busy time has been updated so that there
+ * is a new autosuspend expiration time, automatically
+ * reschedule another autosuspend.
+ */
+ if ((rpmflags & RPM_AUTO) &&
+ pm_runtime_autosuspend_expiration(dev) != 0)
+ goto repeat;
+ } else {
+ pm_runtime_cancel_pending(dev);
+ }
+ goto out;
+}
+
+/**
+ * rpm_resume - Carry out runtime resume of given device.
+ * @dev: Device to resume.
+ * @rpmflags: Flag bits.
+ *
+ * Check if the device's runtime PM status allows it to be resumed. Cancel
+ * any scheduled or pending requests. If another resume has been started
+ * earlier, either return immediately or wait for it to finish, depending on the
+ * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in
+ * parallel with this function, either tell the other process to resume after
+ * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC
+ * flag is set then queue a resume request; otherwise run the
+ * ->runtime_resume() callback directly. Queue an idle notification for the
+ * device if the resume succeeded.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static int rpm_resume(struct device *dev, int rpmflags)
+ __releases(&dev->power.lock) __acquires(&dev->power.lock)
+{
+ int (*callback)(struct device *);
+ struct device *parent = NULL;
+ int retval = 0;
+
+ trace_rpm_resume_rcuidle(dev, rpmflags);
+
+ repeat:
+ if (dev->power.runtime_error)
+ retval = -EINVAL;
+ else if (dev->power.disable_depth == 1 && dev->power.is_suspended
+ && dev->power.runtime_status == RPM_ACTIVE)
+ retval = 1;
+ else if (dev->power.disable_depth > 0)
+ retval = -EACCES;
+ if (retval)
+ goto out;
+
+ /*
+ * Other scheduled or pending requests need to be canceled. Small
+ * optimization: If an autosuspend timer is running, leave it running
+ * rather than cancelling it now only to restart it again in the near
+ * future.
+ */
+ dev->power.request = RPM_REQ_NONE;
+ if (!dev->power.timer_autosuspends)
+ pm_runtime_deactivate_timer(dev);
+
+ if (dev->power.runtime_status == RPM_ACTIVE) {
+ retval = 1;
+ goto out;
+ }
+
+ if (dev->power.runtime_status == RPM_RESUMING
+ || dev->power.runtime_status == RPM_SUSPENDING) {
+ DEFINE_WAIT(wait);
+
+ if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
+ if (dev->power.runtime_status == RPM_SUSPENDING)
+ dev->power.deferred_resume = true;
+ else
+ retval = -EINPROGRESS;
+ goto out;
+ }
+
+ if (dev->power.irq_safe) {
+ spin_unlock(&dev->power.lock);
+
+ cpu_relax();
+
+ spin_lock(&dev->power.lock);
+ goto repeat;
+ }
+
+ /* Wait for the operation carried out in parallel with us. */
+ for (;;) {
+ prepare_to_wait(&dev->power.wait_queue, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (dev->power.runtime_status != RPM_RESUMING
+ && dev->power.runtime_status != RPM_SUSPENDING)
+ break;
+
+ spin_unlock_irq(&dev->power.lock);
+
+ schedule();
+
+ spin_lock_irq(&dev->power.lock);
+ }
+ finish_wait(&dev->power.wait_queue, &wait);
+ goto repeat;
+ }
+
+ /*
+ * See if we can skip waking up the parent. This is safe only if
+ * power.no_callbacks is set, because otherwise we don't know whether
+ * the resume will actually succeed.
+ */
+ if (dev->power.no_callbacks && !parent && dev->parent) {
+ spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING);
+ if (dev->parent->power.disable_depth > 0
+ || dev->parent->power.ignore_children
+ || dev->parent->power.runtime_status == RPM_ACTIVE) {
+ atomic_inc(&dev->parent->power.child_count);
+ spin_unlock(&dev->parent->power.lock);
+ retval = 1;
+ goto no_callback; /* Assume success. */
+ }
+ spin_unlock(&dev->parent->power.lock);
+ }
+
+ /* Carry out an asynchronous or a synchronous resume. */
+ if (rpmflags & RPM_ASYNC) {
+ dev->power.request = RPM_REQ_RESUME;
+ if (!dev->power.request_pending) {
+ dev->power.request_pending = true;
+ queue_work(pm_wq, &dev->power.work);
+ }
+ retval = 0;
+ goto out;
+ }
+
+ if (!parent && dev->parent) {
+ /*
+ * Increment the parent's usage counter and resume it if
+ * necessary. Not needed if dev is irq-safe; then the
+ * parent is permanently resumed.
+ */
+ parent = dev->parent;
+ if (dev->power.irq_safe)
+ goto skip_parent;
+ spin_unlock(&dev->power.lock);
+
+ pm_runtime_get_noresume(parent);
+
+ spin_lock(&parent->power.lock);
+ /*
+ * Resume the parent if it has runtime PM enabled and not been
+ * set to ignore its children.
+ */
+ if (!parent->power.disable_depth
+ && !parent->power.ignore_children) {
+ rpm_resume(parent, 0);
+ if (parent->power.runtime_status != RPM_ACTIVE)
+ retval = -EBUSY;
+ }
+ spin_unlock(&parent->power.lock);
+
+ spin_lock(&dev->power.lock);
+ if (retval)
+ goto out;
+ goto repeat;
+ }
+ skip_parent:
+
+ if (dev->power.no_callbacks)
+ goto no_callback; /* Assume success. */
+
+ __update_runtime_status(dev, RPM_RESUMING);
+
+ callback = RPM_GET_CALLBACK(dev, runtime_resume);
+
+ dev_pm_disable_wake_irq_check(dev);
+ retval = rpm_callback(callback, dev);
+ if (retval) {
+ __update_runtime_status(dev, RPM_SUSPENDED);
+ pm_runtime_cancel_pending(dev);
+ dev_pm_enable_wake_irq_check(dev, false);
+ } else {
+ no_callback:
+ __update_runtime_status(dev, RPM_ACTIVE);
+ pm_runtime_mark_last_busy(dev);
+ if (parent)
+ atomic_inc(&parent->power.child_count);
+ }
+ wake_up_all(&dev->power.wait_queue);
+
+ if (retval >= 0)
+ rpm_idle(dev, RPM_ASYNC);
+
+ out:
+ if (parent && !dev->power.irq_safe) {
+ spin_unlock_irq(&dev->power.lock);
+
+ pm_runtime_put(parent);
+
+ spin_lock_irq(&dev->power.lock);
+ }
+
+ trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);
+
+ return retval;
+}
+
+/**
+ * pm_runtime_work - Universal runtime PM work function.
+ * @work: Work structure used for scheduling the execution of this function.
+ *
+ * Use @work to get the device object the work is to be done for, determine what
+ * is to be done and execute the appropriate runtime PM function.
+ */
+static void pm_runtime_work(struct work_struct *work)
+{
+ struct device *dev = container_of(work, struct device, power.work);
+ enum rpm_request req;
+
+ spin_lock_irq(&dev->power.lock);
+
+ if (!dev->power.request_pending)
+ goto out;
+
+ req = dev->power.request;
+ dev->power.request = RPM_REQ_NONE;
+ dev->power.request_pending = false;
+
+ switch (req) {
+ case RPM_REQ_NONE:
+ break;
+ case RPM_REQ_IDLE:
+ rpm_idle(dev, RPM_NOWAIT);
+ break;
+ case RPM_REQ_SUSPEND:
+ rpm_suspend(dev, RPM_NOWAIT);
+ break;
+ case RPM_REQ_AUTOSUSPEND:
+ rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
+ break;
+ case RPM_REQ_RESUME:
+ rpm_resume(dev, RPM_NOWAIT);
+ break;
+ }
+
+ out:
+ spin_unlock_irq(&dev->power.lock);
+}
+
+/**
+ * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
+ * @data: Device pointer passed by pm_schedule_suspend().
+ *
+ * Check if the time is right and queue a suspend request.
+ */
+static void pm_suspend_timer_fn(struct timer_list *t)
+{
+ struct device *dev = from_timer(dev, t, power.suspend_timer);
+ unsigned long flags;
+ unsigned long expires;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+
+ expires = dev->power.timer_expires;
+ /* If 'expire' is after 'jiffies' we've been called too early. */
+ if (expires > 0 && !time_after(expires, jiffies)) {
+ dev->power.timer_expires = 0;
+ rpm_suspend(dev, dev->power.timer_autosuspends ?
+ (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
+ }
+
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+}
+
+/**
+ * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
+ * @dev: Device to suspend.
+ * @delay: Time to wait before submitting a suspend request, in milliseconds.
+ */
+int pm_schedule_suspend(struct device *dev, unsigned int delay)
+{
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+
+ if (!delay) {
+ retval = rpm_suspend(dev, RPM_ASYNC);
+ goto out;
+ }
+
+ retval = rpm_check_suspend_allowed(dev);
+ if (retval)
+ goto out;
+
+ /* Other scheduled or pending requests need to be canceled. */
+ pm_runtime_cancel_pending(dev);
+
+ dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
+ dev->power.timer_expires += !dev->power.timer_expires;
+ dev->power.timer_autosuspends = 0;
+ mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
+
+ out:
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_schedule_suspend);
+
+/**
+ * __pm_runtime_idle - Entry point for runtime idle operations.
+ * @dev: Device to send idle notification for.
+ * @rpmflags: Flag bits.
+ *
+ * If the RPM_GET_PUT flag is set, decrement the device's usage count and
+ * return immediately if it is larger than zero. Then carry out an idle
+ * notification, either synchronous or asynchronous.
+ *
+ * This routine may be called in atomic context if the RPM_ASYNC flag is set,
+ * or if pm_runtime_irq_safe() has been called.
+ */
+int __pm_runtime_idle(struct device *dev, int rpmflags)
+{
+ unsigned long flags;
+ int retval;
+
+ if (rpmflags & RPM_GET_PUT) {
+ if (!atomic_dec_and_test(&dev->power.usage_count))
+ return 0;
+ }
+
+ might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+ retval = rpm_idle(dev, rpmflags);
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_idle);
+
+/**
+ * __pm_runtime_suspend - Entry point for runtime put/suspend operations.
+ * @dev: Device to suspend.
+ * @rpmflags: Flag bits.
+ *
+ * If the RPM_GET_PUT flag is set, decrement the device's usage count and
+ * return immediately if it is larger than zero. Then carry out a suspend,
+ * either synchronous or asynchronous.
+ *
+ * This routine may be called in atomic context if the RPM_ASYNC flag is set,
+ * or if pm_runtime_irq_safe() has been called.
+ */
+int __pm_runtime_suspend(struct device *dev, int rpmflags)
+{
+ unsigned long flags;
+ int retval;
+
+ if (rpmflags & RPM_GET_PUT) {
+ if (!atomic_dec_and_test(&dev->power.usage_count))
+ return 0;
+ }
+
+ might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe);
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+ retval = rpm_suspend(dev, rpmflags);
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
+
+/**
+ * __pm_runtime_resume - Entry point for runtime resume operations.
+ * @dev: Device to resume.
+ * @rpmflags: Flag bits.
+ *
+ * If the RPM_GET_PUT flag is set, increment the device's usage count. Then
+ * carry out a resume, either synchronous or asynchronous.
+ *
+ * This routine may be called in atomic context if the RPM_ASYNC flag is set,
+ * or if pm_runtime_irq_safe() has been called.
+ */
+int __pm_runtime_resume(struct device *dev, int rpmflags)
+{
+ unsigned long flags;
+ int retval;
+
+ might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe &&
+ dev->power.runtime_status != RPM_ACTIVE);
+
+ if (rpmflags & RPM_GET_PUT)
+ atomic_inc(&dev->power.usage_count);
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+ retval = rpm_resume(dev, rpmflags);
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_resume);
+
+/**
+ * pm_runtime_get_if_in_use - Conditionally bump up the device's usage counter.
+ * @dev: Device to handle.
+ *
+ * Return -EINVAL if runtime PM is disabled for the device.
+ *
+ * If that's not the case and if the device's runtime PM status is RPM_ACTIVE
+ * and the runtime PM usage counter is nonzero, increment the counter and
+ * return 1. Otherwise return 0 without changing the counter.
+ */
+int pm_runtime_get_if_in_use(struct device *dev)
+{
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+ retval = dev->power.disable_depth > 0 ? -EINVAL :
+ dev->power.runtime_status == RPM_ACTIVE
+ && atomic_inc_not_zero(&dev->power.usage_count);
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use);
+
+/**
+ * __pm_runtime_set_status - Set runtime PM status of a device.
+ * @dev: Device to handle.
+ * @status: New runtime PM status of the device.
+ *
+ * If runtime PM of the device is disabled or its power.runtime_error field is
+ * different from zero, the status may be changed either to RPM_ACTIVE, or to
+ * RPM_SUSPENDED, as long as that reflects the actual state of the device.
+ * However, if the device has a parent and the parent is not active, and the
+ * parent's power.ignore_children flag is unset, the device's status cannot be
+ * set to RPM_ACTIVE, so -EBUSY is returned in that case.
+ *
+ * If successful, __pm_runtime_set_status() clears the power.runtime_error field
+ * and the device parent's counter of unsuspended children is modified to
+ * reflect the new status. If the new status is RPM_SUSPENDED, an idle
+ * notification request for the parent is submitted.
+ */
+int __pm_runtime_set_status(struct device *dev, unsigned int status)
+{
+ struct device *parent = dev->parent;
+ unsigned long flags;
+ bool notify_parent = false;
+ int error = 0;
+
+ if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
+ return -EINVAL;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+
+ if (!dev->power.runtime_error && !dev->power.disable_depth) {
+ error = -EAGAIN;
+ goto out;
+ }
+
+ if (dev->power.runtime_status == status || !parent)
+ goto out_set;
+
+ if (status == RPM_SUSPENDED) {
+ atomic_add_unless(&parent->power.child_count, -1, 0);
+ notify_parent = !parent->power.ignore_children;
+ } else {
+ spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
+
+ /*
+ * It is invalid to put an active child under a parent that is
+ * not active, has runtime PM enabled and the
+ * 'power.ignore_children' flag unset.
+ */
+ if (!parent->power.disable_depth
+ && !parent->power.ignore_children
+ && parent->power.runtime_status != RPM_ACTIVE) {
+ dev_err(dev, "runtime PM trying to activate child device %s but parent (%s) is not active\n",
+ dev_name(dev),
+ dev_name(parent));
+ error = -EBUSY;
+ } else if (dev->power.runtime_status == RPM_SUSPENDED) {
+ atomic_inc(&parent->power.child_count);
+ }
+
+ spin_unlock(&parent->power.lock);
+
+ if (error)
+ goto out;
+ }
+
+ out_set:
+ __update_runtime_status(dev, status);
+ dev->power.runtime_error = 0;
+ out:
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+
+ if (notify_parent)
+ pm_request_idle(parent);
+
+ return error;
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
+
+/**
+ * __pm_runtime_barrier - Cancel pending requests and wait for completions.
+ * @dev: Device to handle.
+ *
+ * Flush all pending requests for the device from pm_wq and wait for all
+ * runtime PM operations involving the device in progress to complete.
+ *
+ * Should be called under dev->power.lock with interrupts disabled.
+ */
+static void __pm_runtime_barrier(struct device *dev)
+{
+ pm_runtime_deactivate_timer(dev);
+
+ if (dev->power.request_pending) {
+ dev->power.request = RPM_REQ_NONE;
+ spin_unlock_irq(&dev->power.lock);
+
+ cancel_work_sync(&dev->power.work);
+
+ spin_lock_irq(&dev->power.lock);
+ dev->power.request_pending = false;
+ }
+
+ if (dev->power.runtime_status == RPM_SUSPENDING
+ || dev->power.runtime_status == RPM_RESUMING
+ || dev->power.idle_notification) {
+ DEFINE_WAIT(wait);
+
+ /* Suspend, wake-up or idle notification in progress. */
+ for (;;) {
+ prepare_to_wait(&dev->power.wait_queue, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (dev->power.runtime_status != RPM_SUSPENDING
+ && dev->power.runtime_status != RPM_RESUMING
+ && !dev->power.idle_notification)
+ break;
+ spin_unlock_irq(&dev->power.lock);
+
+ schedule();
+
+ spin_lock_irq(&dev->power.lock);
+ }
+ finish_wait(&dev->power.wait_queue, &wait);
+ }
+}
+
+/**
+ * pm_runtime_barrier - Flush pending requests and wait for completions.
+ * @dev: Device to handle.
+ *
+ * Prevent the device from being suspended by incrementing its usage counter and
+ * if there's a pending resume request for the device, wake the device up.
+ * Next, make sure that all pending requests for the device have been flushed
+ * from pm_wq and wait for all runtime PM operations involving the device in
+ * progress to complete.
+ *
+ * Return value:
+ * 1, if there was a resume request pending and the device had to be woken up,
+ * 0, otherwise
+ */
+int pm_runtime_barrier(struct device *dev)
+{
+ int retval = 0;
+
+ pm_runtime_get_noresume(dev);
+ spin_lock_irq(&dev->power.lock);
+
+ if (dev->power.request_pending
+ && dev->power.request == RPM_REQ_RESUME) {
+ rpm_resume(dev, 0);
+ retval = 1;
+ }
+
+ __pm_runtime_barrier(dev);
+
+ spin_unlock_irq(&dev->power.lock);
+ pm_runtime_put_noidle(dev);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_barrier);
+
+/**
+ * __pm_runtime_disable - Disable runtime PM of a device.
+ * @dev: Device to handle.
+ * @check_resume: If set, check if there's a resume request for the device.
+ *
+ * Increment power.disable_depth for the device and if it was zero previously,
+ * cancel all pending runtime PM requests for the device and wait for all
+ * operations in progress to complete. The device can be either active or
+ * suspended after its runtime PM has been disabled.
+ *
+ * If @check_resume is set and there's a resume request pending when
+ * __pm_runtime_disable() is called and power.disable_depth is zero, the
+ * function will wake up the device before disabling its runtime PM.
+ */
+void __pm_runtime_disable(struct device *dev, bool check_resume)
+{
+ spin_lock_irq(&dev->power.lock);
+
+ if (dev->power.disable_depth > 0) {
+ dev->power.disable_depth++;
+ goto out;
+ }
+
+ /*
+ * Wake up the device if there's a resume request pending, because that
+ * means there probably is some I/O to process and disabling runtime PM
+ * shouldn't prevent the device from processing the I/O.
+ */
+ if (check_resume && dev->power.request_pending
+ && dev->power.request == RPM_REQ_RESUME) {
+ /*
+ * Prevent suspends and idle notifications from being carried
+ * out after we have woken up the device.
+ */
+ pm_runtime_get_noresume(dev);
+
+ rpm_resume(dev, 0);
+
+ pm_runtime_put_noidle(dev);
+ }
+
+ if (!dev->power.disable_depth++)
+ __pm_runtime_barrier(dev);
+
+ out:
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_disable);
+
+/**
+ * pm_runtime_enable - Enable runtime PM of a device.
+ * @dev: Device to handle.
+ */
+void pm_runtime_enable(struct device *dev)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+
+ if (dev->power.disable_depth > 0)
+ dev->power.disable_depth--;
+ else
+ dev_warn(dev, "Unbalanced %s!\n", __func__);
+
+ WARN(!dev->power.disable_depth &&
+ dev->power.runtime_status == RPM_SUSPENDED &&
+ !dev->power.ignore_children &&
+ atomic_read(&dev->power.child_count) > 0,
+ "Enabling runtime PM for inactive device (%s) with active children\n",
+ dev_name(dev));
+
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_enable);
+
+/**
+ * pm_runtime_forbid - Block runtime PM of a device.
+ * @dev: Device to handle.
+ *
+ * Increase the device's usage count and clear its power.runtime_auto flag,
+ * so that it cannot be suspended at run time until pm_runtime_allow() is called
+ * for it.
+ */
+void pm_runtime_forbid(struct device *dev)
+{
+ spin_lock_irq(&dev->power.lock);
+ if (!dev->power.runtime_auto)
+ goto out;
+
+ dev->power.runtime_auto = false;
+ atomic_inc(&dev->power.usage_count);
+ rpm_resume(dev, 0);
+
+ out:
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_forbid);
+
+/**
+ * pm_runtime_allow - Unblock runtime PM of a device.
+ * @dev: Device to handle.
+ *
+ * Decrease the device's usage count and set its power.runtime_auto flag.
+ */
+void pm_runtime_allow(struct device *dev)
+{
+ spin_lock_irq(&dev->power.lock);
+ if (dev->power.runtime_auto)
+ goto out;
+
+ dev->power.runtime_auto = true;
+ if (atomic_dec_and_test(&dev->power.usage_count))
+ rpm_idle(dev, RPM_AUTO | RPM_ASYNC);
+
+ out:
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_allow);
+
+/**
+ * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device.
+ * @dev: Device to handle.
+ *
+ * Set the power.no_callbacks flag, which tells the PM core that this
+ * device is power-managed through its parent and has no runtime PM
+ * callbacks of its own. The runtime sysfs attributes will be removed.
+ */
+void pm_runtime_no_callbacks(struct device *dev)
+{
+ spin_lock_irq(&dev->power.lock);
+ dev->power.no_callbacks = 1;
+ spin_unlock_irq(&dev->power.lock);
+ if (device_is_registered(dev))
+ rpm_sysfs_remove(dev);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
+
+/**
+ * pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
+ * @dev: Device to handle
+ *
+ * Set the power.irq_safe flag, which tells the PM core that the
+ * ->runtime_suspend() and ->runtime_resume() callbacks for this device should
+ * always be invoked with the spinlock held and interrupts disabled. It also
+ * causes the parent's usage counter to be permanently incremented, preventing
+ * the parent from runtime suspending -- otherwise an irq-safe child might have
+ * to wait for a non-irq-safe parent.
+ */
+void pm_runtime_irq_safe(struct device *dev)
+{
+ if (dev->parent)
+ pm_runtime_get_sync(dev->parent);
+ spin_lock_irq(&dev->power.lock);
+ dev->power.irq_safe = 1;
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);
+
+/**
+ * update_autosuspend - Handle a change to a device's autosuspend settings.
+ * @dev: Device to handle.
+ * @old_delay: The former autosuspend_delay value.
+ * @old_use: The former use_autosuspend value.
+ *
+ * Prevent runtime suspend if the new delay is negative and use_autosuspend is
+ * set; otherwise allow it. Send an idle notification if suspends are allowed.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static void update_autosuspend(struct device *dev, int old_delay, int old_use)
+{
+ int delay = dev->power.autosuspend_delay;
+
+ /* Should runtime suspend be prevented now? */
+ if (dev->power.use_autosuspend && delay < 0) {
+
+ /* If it used to be allowed then prevent it. */
+ if (!old_use || old_delay >= 0) {
+ atomic_inc(&dev->power.usage_count);
+ rpm_resume(dev, 0);
+ }
+ }
+
+ /* Runtime suspend should be allowed now. */
+ else {
+
+ /* If it used to be prevented then allow it. */
+ if (old_use && old_delay < 0)
+ atomic_dec(&dev->power.usage_count);
+
+ /* Maybe we can autosuspend now. */
+ rpm_idle(dev, RPM_AUTO);
+ }
+}
+
+/**
+ * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
+ * @dev: Device to handle.
+ * @delay: Value of the new delay in milliseconds.
+ *
+ * Set the device's power.autosuspend_delay value. If it changes to negative
+ * and the power.use_autosuspend flag is set, prevent runtime suspends. If it
+ * changes the other way, allow runtime suspends.
+ */
+void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
+{
+ int old_delay, old_use;
+
+ spin_lock_irq(&dev->power.lock);
+ old_delay = dev->power.autosuspend_delay;
+ old_use = dev->power.use_autosuspend;
+ dev->power.autosuspend_delay = delay;
+ update_autosuspend(dev, old_delay, old_use);
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
+
+/**
+ * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
+ * @dev: Device to handle.
+ * @use: New value for use_autosuspend.
+ *
+ * Set the device's power.use_autosuspend flag, and allow or prevent runtime
+ * suspends as needed.
+ */
+void __pm_runtime_use_autosuspend(struct device *dev, bool use)
+{
+ int old_delay, old_use;
+
+ spin_lock_irq(&dev->power.lock);
+ old_delay = dev->power.autosuspend_delay;
+ old_use = dev->power.use_autosuspend;
+ dev->power.use_autosuspend = use;
+ update_autosuspend(dev, old_delay, old_use);
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
+
+/**
+ * pm_runtime_init - Initialize runtime PM fields in given device object.
+ * @dev: Device object to initialize.
+ */
+void pm_runtime_init(struct device *dev)
+{
+ dev->power.runtime_status = RPM_SUSPENDED;
+ dev->power.idle_notification = false;
+
+ dev->power.disable_depth = 1;
+ atomic_set(&dev->power.usage_count, 0);
+
+ dev->power.runtime_error = 0;
+
+ atomic_set(&dev->power.child_count, 0);
+ pm_suspend_ignore_children(dev, false);
+ dev->power.runtime_auto = true;
+
+ dev->power.request_pending = false;
+ dev->power.request = RPM_REQ_NONE;
+ dev->power.deferred_resume = false;
+ dev->power.accounting_timestamp = jiffies;
+ INIT_WORK(&dev->power.work, pm_runtime_work);
+
+ dev->power.timer_expires = 0;
+ timer_setup(&dev->power.suspend_timer, pm_suspend_timer_fn, 0);
+
+ init_waitqueue_head(&dev->power.wait_queue);
+}
+
+/**
+ * pm_runtime_reinit - Re-initialize runtime PM fields in given device object.
+ * @dev: Device object to re-initialize.
+ */
+void pm_runtime_reinit(struct device *dev)
+{
+ if (!pm_runtime_enabled(dev)) {
+ if (dev->power.runtime_status == RPM_ACTIVE)
+ pm_runtime_set_suspended(dev);
+ if (dev->power.irq_safe) {
+ spin_lock_irq(&dev->power.lock);
+ dev->power.irq_safe = 0;
+ spin_unlock_irq(&dev->power.lock);
+ if (dev->parent)
+ pm_runtime_put(dev->parent);
+ }
+ }
+}
+
+/**
+ * pm_runtime_remove - Prepare for removing a device from device hierarchy.
+ * @dev: Device object being removed from device hierarchy.
+ */
+void pm_runtime_remove(struct device *dev)
+{
+ __pm_runtime_disable(dev, false);
+ pm_runtime_reinit(dev);
+}
+
+/**
+ * pm_runtime_clean_up_links - Prepare links to consumers for driver removal.
+ * @dev: Device whose driver is going to be removed.
+ *
+ * Check links from this device to any consumers and if any of them have active
+ * runtime PM references to the device, drop the usage counter of the device
+ * (once per link).
+ *
+ * Links with the DL_FLAG_STATELESS flag set are ignored.
+ *
+ * Since the device is guaranteed to be runtime-active at the point this is
+ * called, nothing else needs to be done here.
+ *
+ * Moreover, this is called after device_links_busy() has returned 'false', so
+ * the status of each link is guaranteed to be DL_STATE_SUPPLIER_UNBIND and
+ * therefore rpm_active can't be manipulated concurrently.
+ */
+void pm_runtime_clean_up_links(struct device *dev)
+{
+ struct device_link *link;
+ int idx;
+
+ idx = device_links_read_lock();
+
+ list_for_each_entry_rcu(link, &dev->links.consumers, s_node) {
+ if (link->flags & DL_FLAG_STATELESS)
+ continue;
+
+ if (link->rpm_active) {
+ pm_runtime_put_noidle(dev);
+ link->rpm_active = false;
+ }
+ }
+
+ device_links_read_unlock(idx);
+}
+
+/**
+ * pm_runtime_get_suppliers - Resume and reference-count supplier devices.
+ * @dev: Consumer device.
+ */
+void pm_runtime_get_suppliers(struct device *dev)
+{
+ struct device_link *link;
+ int idx;
+
+ idx = device_links_read_lock();
+
+ list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
+ if (link->flags & DL_FLAG_PM_RUNTIME)
+ pm_runtime_get_sync(link->supplier);
+
+ device_links_read_unlock(idx);
+}
+
+/**
+ * pm_runtime_put_suppliers - Drop references to supplier devices.
+ * @dev: Consumer device.
+ */
+void pm_runtime_put_suppliers(struct device *dev)
+{
+ struct device_link *link;
+ int idx;
+
+ idx = device_links_read_lock();
+
+ list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
+ if (link->flags & DL_FLAG_PM_RUNTIME)
+ pm_runtime_put(link->supplier);
+
+ device_links_read_unlock(idx);
+}
+
+void pm_runtime_new_link(struct device *dev)
+{
+ spin_lock_irq(&dev->power.lock);
+ dev->power.links_count++;
+ spin_unlock_irq(&dev->power.lock);
+}
+
+void pm_runtime_drop_link(struct device *dev)
+{
+ rpm_put_suppliers(dev);
+
+ spin_lock_irq(&dev->power.lock);
+ WARN_ON(dev->power.links_count == 0);
+ dev->power.links_count--;
+ spin_unlock_irq(&dev->power.lock);
+}
+
+static bool pm_runtime_need_not_resume(struct device *dev)
+{
+ return atomic_read(&dev->power.usage_count) <= 1 &&
+ (atomic_read(&dev->power.child_count) == 0 ||
+ dev->power.ignore_children);
+}
+
+/**
+ * pm_runtime_force_suspend - Force a device into suspend state if needed.
+ * @dev: Device to suspend.
+ *
+ * Disable runtime PM so we safely can check the device's runtime PM status and
+ * if it is active, invoke its ->runtime_suspend callback to suspend it and
+ * change its runtime PM status field to RPM_SUSPENDED. Also, if the device's
+ * usage and children counters don't indicate that the device was in use before
+ * the system-wide transition under way, decrement its parent's children counter
+ * (if there is a parent). Keep runtime PM disabled to preserve the state
+ * unless we encounter errors.
+ *
+ * Typically this function may be invoked from a system suspend callback to make
+ * sure the device is put into low power state and it should only be used during
+ * system-wide PM transitions to sleep states. It assumes that the analogous
+ * pm_runtime_force_resume() will be used to resume the device.
+ */
+int pm_runtime_force_suspend(struct device *dev)
+{
+ int (*callback)(struct device *);
+ int ret;
+
+ pm_runtime_disable(dev);
+ if (pm_runtime_status_suspended(dev))
+ return 0;
+
+ callback = RPM_GET_CALLBACK(dev, runtime_suspend);
+
+ ret = callback ? callback(dev) : 0;
+ if (ret)
+ goto err;
+
+ /*
+ * If the device can stay in suspend after the system-wide transition
+ * to the working state that will follow, drop the children counter of
+ * its parent, but set its status to RPM_SUSPENDED anyway in case this
+ * function will be called again for it in the meantime.
+ */
+ if (pm_runtime_need_not_resume(dev))
+ pm_runtime_set_suspended(dev);
+ else
+ __update_runtime_status(dev, RPM_SUSPENDED);
+
+ return 0;
+
+err:
+ pm_runtime_enable(dev);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_force_suspend);
+
+/**
+ * pm_runtime_force_resume - Force a device into resume state if needed.
+ * @dev: Device to resume.
+ *
+ * Prior invoking this function we expect the user to have brought the device
+ * into low power state by a call to pm_runtime_force_suspend(). Here we reverse
+ * those actions and bring the device into full power, if it is expected to be
+ * used on system resume. In the other case, we defer the resume to be managed
+ * via runtime PM.
+ *
+ * Typically this function may be invoked from a system resume callback.
+ */
+int pm_runtime_force_resume(struct device *dev)
+{
+ int (*callback)(struct device *);
+ int ret = 0;
+
+ if (!pm_runtime_status_suspended(dev) || pm_runtime_need_not_resume(dev))
+ goto out;
+
+ /*
+ * The value of the parent's children counter is correct already, so
+ * just update the status of the device.
+ */
+ __update_runtime_status(dev, RPM_ACTIVE);
+
+ callback = RPM_GET_CALLBACK(dev, runtime_resume);
+
+ ret = callback ? callback(dev) : 0;
+ if (ret) {
+ pm_runtime_set_suspended(dev);
+ goto out;
+ }
+
+ pm_runtime_mark_last_busy(dev);
+out:
+ pm_runtime_enable(dev);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_force_resume);