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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * drivers/base/power/domain.c - Common code related to device power domains.
  *
  * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
  */
 #define pr_fmt(fmt) "PM: " fmt
 
 #include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
 #include <linux/pm_opp.h>
 #include <linux/pm_runtime.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_qos.h>
 #include <linux/pm_clock.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/sched.h>
 #include <linux/suspend.h>
 #include <linux/export.h>
 #include <linux/cpu.h>
 #include <linux/debugfs.h>
 
 #include "power.h"
 
 #define GENPD_RETRY_MAX_MS  250     /* Approximate */
 
 #define GENPD_DEV_CALLBACK(genpd, type, callback, dev)      \
 ({                              \
     type (*__routine)(struct device *__d);          \
     type __ret = (type)0;                   \
                                 \
     __routine = genpd->dev_ops.callback;            \
     if (__routine) {                    \
         __ret = __routine(dev);             \
     }                           \
     __ret;                          \
 })
 
 static LIST_HEAD(gpd_list);
 static DEFINE_MUTEX(gpd_list_lock);
 
 struct genpd_lock_ops {
     void (*lock)(struct generic_pm_domain *genpd);
     void (*lock_nested)(struct generic_pm_domain *genpd, int depth);
     int (*lock_interruptible)(struct generic_pm_domain *genpd);
     void (*unlock)(struct generic_pm_domain *genpd);
 };
 
 static void genpd_lock_mtx(struct generic_pm_domain *genpd)
 {
     mutex_lock(&genpd->mlock);
 }
 
 static void genpd_lock_nested_mtx(struct generic_pm_domain *genpd,
                     int depth)
 {
     mutex_lock_nested(&genpd->mlock, depth);
 }
 
 static int genpd_lock_interruptible_mtx(struct generic_pm_domain *genpd)
 {
     return mutex_lock_interruptible(&genpd->mlock);
 }
 
 static void genpd_unlock_mtx(struct generic_pm_domain *genpd)
 {
     return mutex_unlock(&genpd->mlock);
 }
 
 static const struct genpd_lock_ops genpd_mtx_ops = {
     .lock = genpd_lock_mtx,
     .lock_nested = genpd_lock_nested_mtx,
     .lock_interruptible = genpd_lock_interruptible_mtx,
     .unlock = genpd_unlock_mtx,
 };
 
 static void genpd_lock_spin(struct generic_pm_domain *genpd)
     __acquires(&genpd->slock)
 {
     unsigned long flags;
 
     spin_lock_irqsave(&genpd->slock, flags);
     genpd->lock_flags = flags;
 }
 
 static void genpd_lock_nested_spin(struct generic_pm_domain *genpd,
                     int depth)
     __acquires(&genpd->slock)
 {
     unsigned long flags;
 
     spin_lock_irqsave_nested(&genpd->slock, flags, depth);
     genpd->lock_flags = flags;
 }
 
 static int genpd_lock_interruptible_spin(struct generic_pm_domain *genpd)
     __acquires(&genpd->slock)
 {
     unsigned long flags;
 
     spin_lock_irqsave(&genpd->slock, flags);
     genpd->lock_flags = flags;
     return 0;
 }
 
 static void genpd_unlock_spin(struct generic_pm_domain *genpd)
     __releases(&genpd->slock)
 {
     spin_unlock_irqrestore(&genpd->slock, genpd->lock_flags);
 }
 
 static const struct genpd_lock_ops genpd_spin_ops = {
     .lock = genpd_lock_spin,
     .lock_nested = genpd_lock_nested_spin,
     .lock_interruptible = genpd_lock_interruptible_spin,
     .unlock = genpd_unlock_spin,
 };
 
 #define genpd_lock(p)           p->lock_ops->lock(p)
 #define genpd_lock_nested(p, d)     p->lock_ops->lock_nested(p, d)
 #define genpd_lock_interruptible(p) p->lock_ops->lock_interruptible(p)
 #define genpd_unlock(p)         p->lock_ops->unlock(p)
 
 #define genpd_status_on(genpd)      (genpd->status == GENPD_STATE_ON)
 #define genpd_is_irq_safe(genpd)    (genpd->flags & GENPD_FLAG_IRQ_SAFE)
 #define genpd_is_always_on(genpd)   (genpd->flags & GENPD_FLAG_ALWAYS_ON)
 #define genpd_is_active_wakeup(genpd)   (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP)
 #define genpd_is_cpu_domain(genpd)  (genpd->flags & GENPD_FLAG_CPU_DOMAIN)
 #define genpd_is_rpm_always_on(genpd)   (genpd->flags & GENPD_FLAG_RPM_ALWAYS_ON)
 
 static inline bool irq_safe_dev_in_sleep_domain(struct device *dev,
         const struct generic_pm_domain *genpd)
 {
     bool ret;
 
     ret = pm_runtime_is_irq_safe(dev) && !genpd_is_irq_safe(genpd);
 
     /*
      * Warn once if an IRQ safe device is attached to a domain, which
      * callbacks are allowed to sleep. This indicates a suboptimal
      * configuration for PM, but it doesn't matter for an always on domain.
      */
     if (genpd_is_always_on(genpd) || genpd_is_rpm_always_on(genpd))
         return ret;
 
     if (ret)
         dev_warn_once(dev, "PM domain %s will not be powered off\n",
                 genpd->name);
 
     return ret;
 }
 
 static int genpd_runtime_suspend(struct device *dev);
 
 /*
  * Get the generic PM domain for a particular struct device.
  * This validates the struct device pointer, the PM domain pointer,
  * and checks that the PM domain pointer is a real generic PM domain.
  * Any failure results in NULL being returned.
  */
 static struct generic_pm_domain *dev_to_genpd_safe(struct device *dev)
 {
     if (IS_ERR_OR_NULL(dev) || IS_ERR_OR_NULL(dev->pm_domain))
         return NULL;
 
     /* A genpd's always have its ->runtime_suspend() callback assigned. */
     if (dev->pm_domain->ops.runtime_suspend == genpd_runtime_suspend)
         return pd_to_genpd(dev->pm_domain);
 
     return NULL;
 }
 
 /*
  * This should only be used where we are certain that the pm_domain
  * attached to the device is a genpd domain.
  */
 static struct generic_pm_domain *dev_to_genpd(struct device *dev)
 {
     if (IS_ERR_OR_NULL(dev->pm_domain))
         return ERR_PTR(-EINVAL);
 
     return pd_to_genpd(dev->pm_domain);
 }
 
 static int genpd_stop_dev(const struct generic_pm_domain *genpd,
               struct device *dev)
 {
     return GENPD_DEV_CALLBACK(genpd, int, stop, dev);
 }
 
 static int genpd_start_dev(const struct generic_pm_domain *genpd,
                struct device *dev)
 {
     return GENPD_DEV_CALLBACK(genpd, int, start, dev);
 }
 
 static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
 {
     bool ret = false;
 
     if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
         ret = !!atomic_dec_and_test(&genpd->sd_count);
 
     return ret;
 }
 
 static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
 {
     atomic_inc(&genpd->sd_count);
     smp_mb__after_atomic();
 }
 
 #ifdef CONFIG_DEBUG_FS
 static struct dentry *genpd_debugfs_dir;
 
 static void genpd_debug_add(struct generic_pm_domain *genpd);
 
 static void genpd_debug_remove(struct generic_pm_domain *genpd)
 {
     struct dentry *d;
 
     if (!genpd_debugfs_dir)
         return;
 
     d = debugfs_lookup(genpd->name, genpd_debugfs_dir);
     debugfs_remove(d);
 }
 
 static void genpd_update_accounting(struct generic_pm_domain *genpd)
 {
     u64 delta, now;
 
     now = ktime_get_mono_fast_ns();
     if (now <= genpd->accounting_time)
         return;
 
     delta = now - genpd->accounting_time;
 
     /*
      * If genpd->status is active, it means we are just
      * out of off and so update the idle time and vice
      * versa.
      */
     if (genpd->status == GENPD_STATE_ON)
         genpd->states[genpd->state_idx].idle_time += delta;
     else
         genpd->on_time += delta;
 
     genpd->accounting_time = now;
 }
 #else
 static inline void genpd_debug_add(struct generic_pm_domain *genpd) {}
 static inline void genpd_debug_remove(struct generic_pm_domain *genpd) {}
 static inline void genpd_update_accounting(struct generic_pm_domain *genpd) {}
 #endif
 
 static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd,
                        unsigned int state)
 {
     struct generic_pm_domain_data *pd_data;
     struct pm_domain_data *pdd;
     struct gpd_link *link;
 
     /* New requested state is same as Max requested state */
     if (state == genpd->performance_state)
         return state;
 
     /* New requested state is higher than Max requested state */
     if (state > genpd->performance_state)
         return state;
 
     /* Traverse all devices within the domain */
     list_for_each_entry(pdd, &genpd->dev_list, list_node) {
         pd_data = to_gpd_data(pdd);
 
         if (pd_data->performance_state > state)
             state = pd_data->performance_state;
     }
 
     /*
      * Traverse all sub-domains within the domain. This can be
      * done without any additional locking as the link->performance_state
      * field is protected by the parent genpd->lock, which is already taken.
      *
      * Also note that link->performance_state (subdomain's performance state
      * requirement to parent domain) is different from
      * link->child->performance_state (current performance state requirement
      * of the devices/sub-domains of the subdomain) and so can have a
      * different value.
      *
      * Note that we also take vote from powered-off sub-domains into account
      * as the same is done for devices right now.
      */
     list_for_each_entry(link, &genpd->parent_links, parent_node) {
         if (link->performance_state > state)
             state = link->performance_state;
     }
 
     return state;
 }
 
 static int genpd_xlate_performance_state(struct generic_pm_domain *genpd,
                      struct generic_pm_domain *parent,
                      unsigned int pstate)
 {
     if (!parent->set_performance_state)
         return pstate;
 
     return dev_pm_opp_xlate_performance_state(genpd->opp_table,
                           parent->opp_table,
                           pstate);
 }
 
 static int _genpd_set_performance_state(struct generic_pm_domain *genpd,
                     unsigned int state, int depth)
 {
     struct generic_pm_domain *parent;
     struct gpd_link *link;
     int parent_state, ret;
 
     if (state == genpd->performance_state)
         return 0;
 
     /* Propagate to parents of genpd */
     list_for_each_entry(link, &genpd->child_links, child_node) {
         parent = link->parent;
 
         /* Find parent's performance state */
         ret = genpd_xlate_performance_state(genpd, parent, state);
         if (unlikely(ret < 0))
             goto err;
 
         parent_state = ret;
 
         genpd_lock_nested(parent, depth + 1);
 
         link->prev_performance_state = link->performance_state;
         link->performance_state = parent_state;
         parent_state = _genpd_reeval_performance_state(parent,
                         parent_state);
         ret = _genpd_set_performance_state(parent, parent_state, depth + 1);
         if (ret)
             link->performance_state = link->prev_performance_state;
 
         genpd_unlock(parent);
 
         if (ret)
             goto err;
     }
 
     if (genpd->set_performance_state) {
         ret = genpd->set_performance_state(genpd, state);
         if (ret)
             goto err;
     }
 
     genpd->performance_state = state;
     return 0;
 
 err:
     /* Encountered an error, lets rollback */
     list_for_each_entry_continue_reverse(link, &genpd->child_links,
                          child_node) {
         parent = link->parent;
 
         genpd_lock_nested(parent, depth + 1);
 
         parent_state = link->prev_performance_state;
         link->performance_state = parent_state;
 
         parent_state = _genpd_reeval_performance_state(parent,
                         parent_state);
         if (_genpd_set_performance_state(parent, parent_state, depth + 1)) {
             pr_err("%s: Failed to roll back to %d performance state\n",
                    parent->name, parent_state);
         }
 
         genpd_unlock(parent);
     }
 
     return ret;
 }
 
 static int genpd_set_performance_state(struct device *dev, unsigned int state)
 {
     struct generic_pm_domain *genpd = dev_to_genpd(dev);
     struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
     unsigned int prev_state;
     int ret;
 
     prev_state = gpd_data->performance_state;
     if (prev_state == state)
         return 0;
 
     gpd_data->performance_state = state;
     state = _genpd_reeval_performance_state(genpd, state);
 
     ret = _genpd_set_performance_state(genpd, state, 0);
     if (ret)
         gpd_data->performance_state = prev_state;
 
     return ret;
 }
 
 static int genpd_drop_performance_state(struct device *dev)
 {
     unsigned int prev_state = dev_gpd_data(dev)->performance_state;
 
     if (!genpd_set_performance_state(dev, 0))
         return prev_state;
 
     return 0;
 }
 
 static void genpd_restore_performance_state(struct device *dev,
                         unsigned int state)
 {
     if (state)
         genpd_set_performance_state(dev, state);
 }
 
 /**
  * dev_pm_genpd_set_performance_state- Set performance state of device's power
  * domain.
  *
  * @dev: Device for which the performance-state needs to be set.
  * @state: Target performance state of the device. This can be set as 0 when the
  *     device doesn't have any performance state constraints left (And so
  *     the device wouldn't participate anymore to find the target
  *     performance state of the genpd).
  *
  * It is assumed that the users guarantee that the genpd wouldn't be detached
  * while this routine is getting called.
  *
  * Returns 0 on success and negative error values on failures.
  */
 int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
 {
     struct generic_pm_domain *genpd;
     int ret = 0;
 
     genpd = dev_to_genpd_safe(dev);
     if (!genpd)
         return -ENODEV;
 
     if (WARN_ON(!dev->power.subsys_data ||
              !dev->power.subsys_data->domain_data))
         return -EINVAL;
 
     genpd_lock(genpd);
     if (pm_runtime_suspended(dev)) {
         dev_gpd_data(dev)->rpm_pstate = state;
     } else {
         ret = genpd_set_performance_state(dev, state);
         if (!ret)
             dev_gpd_data(dev)->rpm_pstate = 0;
     }
     genpd_unlock(genpd);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_genpd_set_performance_state);
 
 /**
  * dev_pm_genpd_set_next_wakeup - Notify PM framework of an impending wakeup.
  *
  * @dev: Device to handle
  * @next: impending interrupt/wakeup for the device
  *
  *
  * Allow devices to inform of the next wakeup. It's assumed that the users
  * guarantee that the genpd wouldn't be detached while this routine is getting
  * called. Additionally, it's also assumed that @dev isn't runtime suspended
  * (RPM_SUSPENDED)."
  * Although devices are expected to update the next_wakeup after the end of
  * their usecase as well, it is possible the devices themselves may not know
  * about that, so stale @next will be ignored when powering off the domain.
  */
 void dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next)
 {
     struct generic_pm_domain *genpd;
     struct gpd_timing_data *td;
 
     genpd = dev_to_genpd_safe(dev);
     if (!genpd)
         return;
 
     td = to_gpd_data(dev->power.subsys_data->domain_data)->td;
     if (td)
         td->next_wakeup = next;
 }
 EXPORT_SYMBOL_GPL(dev_pm_genpd_set_next_wakeup);
 
 static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
 {
     unsigned int state_idx = genpd->state_idx;
     ktime_t time_start;
     s64 elapsed_ns;
     int ret;
 
     /* Notify consumers that we are about to power on. */
     ret = raw_notifier_call_chain_robust(&genpd->power_notifiers,
                          GENPD_NOTIFY_PRE_ON,
                          GENPD_NOTIFY_OFF, NULL);
     ret = notifier_to_errno(ret);
     if (ret)
         return ret;
 
     if (!genpd->power_on)
         goto out;
 
     timed = timed && genpd->gd && !genpd->states[state_idx].fwnode;
     if (!timed) {
         ret = genpd->power_on(genpd);
         if (ret)
             goto err;
 
         goto out;
     }
 
     time_start = ktime_get();
     ret = genpd->power_on(genpd);
     if (ret)
         goto err;
 
     elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
     if (elapsed_ns <= genpd->states[state_idx].power_on_latency_ns)
         goto out;
 
     genpd->states[state_idx].power_on_latency_ns = elapsed_ns;
     genpd->gd->max_off_time_changed = true;
     pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
          genpd->name, "on", elapsed_ns);
 
 out:
     raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_ON, NULL);
     return 0;
 err:
     raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_OFF,
                 NULL);
     return ret;
 }
 
 static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
 {
     unsigned int state_idx = genpd->state_idx;
     ktime_t time_start;
     s64 elapsed_ns;
     int ret;
 
     /* Notify consumers that we are about to power off. */
     ret = raw_notifier_call_chain_robust(&genpd->power_notifiers,
                          GENPD_NOTIFY_PRE_OFF,
                          GENPD_NOTIFY_ON, NULL);
     ret = notifier_to_errno(ret);
     if (ret)
         return ret;
 
     if (!genpd->power_off)
         goto out;
 
     timed = timed && genpd->gd && !genpd->states[state_idx].fwnode;
     if (!timed) {
         ret = genpd->power_off(genpd);
         if (ret)
             goto busy;
 
         goto out;
     }
 
     time_start = ktime_get();
     ret = genpd->power_off(genpd);
     if (ret)
         goto busy;
 
     elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
     if (elapsed_ns <= genpd->states[state_idx].power_off_latency_ns)
         goto out;
 
     genpd->states[state_idx].power_off_latency_ns = elapsed_ns;
     genpd->gd->max_off_time_changed = true;
     pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
          genpd->name, "off", elapsed_ns);
 
 out:
     raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_OFF,
                 NULL);
     return 0;
 busy:
     raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_ON, NULL);
     return ret;
 }
 
 /**
  * genpd_queue_power_off_work - Queue up the execution of genpd_power_off().
  * @genpd: PM domain to power off.
  *
  * Queue up the execution of genpd_power_off() unless it's already been done
  * before.
  */
 static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
 {
     queue_work(pm_wq, &genpd->power_off_work);
 }
 
 /**
  * genpd_power_off - Remove power from a given PM domain.
  * @genpd: PM domain to power down.
  * @one_dev_on: If invoked from genpd's ->runtime_suspend|resume() callback, the
  * RPM status of the releated device is in an intermediate state, not yet turned
  * into RPM_SUSPENDED. This means genpd_power_off() must allow one device to not
  * be RPM_SUSPENDED, while it tries to power off the PM domain.
  * @depth: nesting count for lockdep.
  *
  * If all of the @genpd's devices have been suspended and all of its subdomains
  * have been powered down, remove power from @genpd.
  */
 static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
                unsigned int depth)
 {
     struct pm_domain_data *pdd;
     struct gpd_link *link;
     unsigned int not_suspended = 0;
     int ret;
 
     /*
      * Do not try to power off the domain in the following situations:
      * (1) The domain is already in the "power off" state.
      * (2) System suspend is in progress.
      */
     if (!genpd_status_on(genpd) || genpd->prepared_count > 0)
         return 0;
 
     /*
      * Abort power off for the PM domain in the following situations:
      * (1) The domain is configured as always on.
      * (2) When the domain has a subdomain being powered on.
      */
     if (genpd_is_always_on(genpd) ||
             genpd_is_rpm_always_on(genpd) ||
             atomic_read(&genpd->sd_count) > 0)
         return -EBUSY;
 
     /*
      * The children must be in their deepest (powered-off) states to allow
      * the parent to be powered off. Note that, there's no need for
      * additional locking, as powering on a child, requires the parent's
      * lock to be acquired first.
      */
     list_for_each_entry(link, &genpd->parent_links, parent_node) {
         struct generic_pm_domain *child = link->child;
         if (child->state_idx < child->state_count - 1)
             return -EBUSY;
     }
 
     list_for_each_entry(pdd, &genpd->dev_list, list_node) {
         /*
          * Do not allow PM domain to be powered off, when an IRQ safe
          * device is part of a non-IRQ safe domain.
          */
         if (!pm_runtime_suspended(pdd->dev) ||
             irq_safe_dev_in_sleep_domain(pdd->dev, genpd))
             not_suspended++;
     }
 
     if (not_suspended > 1 || (not_suspended == 1 && !one_dev_on))
         return -EBUSY;
 
     if (genpd->gov && genpd->gov->power_down_ok) {
         if (!genpd->gov->power_down_ok(&genpd->domain))
             return -EAGAIN;
     }
 
     /* Default to shallowest state. */
     if (!genpd->gov)
         genpd->state_idx = 0;
 
     /* Don't power off, if a child domain is waiting to power on. */
     if (atomic_read(&genpd->sd_count) > 0)
         return -EBUSY;
 
     ret = _genpd_power_off(genpd, true);
     if (ret) {
         genpd->states[genpd->state_idx].rejected++;
         return ret;
     }
 
     genpd->status = GENPD_STATE_OFF;
     genpd_update_accounting(genpd);
     genpd->states[genpd->state_idx].usage++;
 
     list_for_each_entry(link, &genpd->child_links, child_node) {
         genpd_sd_counter_dec(link->parent);
         genpd_lock_nested(link->parent, depth + 1);
         genpd_power_off(link->parent, false, depth + 1);
         genpd_unlock(link->parent);
     }
 
     return 0;
 }
 
 /**
  * genpd_power_on - Restore power to a given PM domain and its parents.
  * @genpd: PM domain to power up.
  * @depth: nesting count for lockdep.
  *
  * Restore power to @genpd and all of its parents so that it is possible to
  * resume a device belonging to it.
  */
 static int genpd_power_on(struct generic_pm_domain *genpd, unsigned int depth)
 {
     struct gpd_link *link;
     int ret = 0;
 
     if (genpd_status_on(genpd))
         return 0;
 
     /*
      * The list is guaranteed not to change while the loop below is being
      * executed, unless one of the parents' .power_on() callbacks fiddles
      * with it.
      */
     list_for_each_entry(link, &genpd->child_links, child_node) {
         struct generic_pm_domain *parent = link->parent;
 
         genpd_sd_counter_inc(parent);
 
         genpd_lock_nested(parent, depth + 1);
         ret = genpd_power_on(parent, depth + 1);
         genpd_unlock(parent);
 
         if (ret) {
             genpd_sd_counter_dec(parent);
             goto err;
         }
     }
 
     ret = _genpd_power_on(genpd, true);
     if (ret)
         goto err;
 
     genpd->status = GENPD_STATE_ON;
     genpd_update_accounting(genpd);
 
     return 0;
 
  err:
     list_for_each_entry_continue_reverse(link,
                     &genpd->child_links,
                     child_node) {
         genpd_sd_counter_dec(link->parent);
         genpd_lock_nested(link->parent, depth + 1);
         genpd_power_off(link->parent, false, depth + 1);
         genpd_unlock(link->parent);
     }
 
     return ret;
 }
 
 static int genpd_dev_pm_start(struct device *dev)
 {
     struct generic_pm_domain *genpd = dev_to_genpd(dev);
 
     return genpd_start_dev(genpd, dev);
 }
 
 static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
                      unsigned long val, void *ptr)
 {
     struct generic_pm_domain_data *gpd_data;
     struct device *dev;
 
     gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
     dev = gpd_data->base.dev;
 
     for (;;) {
         struct generic_pm_domain *genpd = ERR_PTR(-ENODATA);
         struct pm_domain_data *pdd;
         struct gpd_timing_data *td;
 
         spin_lock_irq(&dev->power.lock);
 
         pdd = dev->power.subsys_data ?
                 dev->power.subsys_data->domain_data : NULL;
         if (pdd) {
             td = to_gpd_data(pdd)->td;
             if (td) {
                 td->constraint_changed = true;
                 genpd = dev_to_genpd(dev);
             }
         }
 
         spin_unlock_irq(&dev->power.lock);
 
         if (!IS_ERR(genpd)) {
             genpd_lock(genpd);
             genpd->gd->max_off_time_changed = true;
             genpd_unlock(genpd);
         }
 
         dev = dev->parent;
         if (!dev || dev->power.ignore_children)
             break;
     }
 
     return NOTIFY_DONE;
 }
 
 /**
  * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
  * @work: Work structure used for scheduling the execution of this function.
  */
 static void genpd_power_off_work_fn(struct work_struct *work)
 {
     struct generic_pm_domain *genpd;
 
     genpd = container_of(work, struct generic_pm_domain, power_off_work);
 
     genpd_lock(genpd);
     genpd_power_off(genpd, false, 0);
     genpd_unlock(genpd);
 }
 
 /**
  * __genpd_runtime_suspend - walk the hierarchy of ->runtime_suspend() callbacks
  * @dev: Device to handle.
  */
 static int __genpd_runtime_suspend(struct device *dev)
 {
     int (*cb)(struct device *__dev);
 
     if (dev->type && dev->type->pm)
         cb = dev->type->pm->runtime_suspend;
     else if (dev->class && dev->class->pm)
         cb = dev->class->pm->runtime_suspend;
     else if (dev->bus && dev->bus->pm)
         cb = dev->bus->pm->runtime_suspend;
     else
         cb = NULL;
 
     if (!cb && dev->driver && dev->driver->pm)
         cb = dev->driver->pm->runtime_suspend;
 
     return cb ? cb(dev) : 0;
 }
 
 /**
  * __genpd_runtime_resume - walk the hierarchy of ->runtime_resume() callbacks
  * @dev: Device to handle.
  */
 static int __genpd_runtime_resume(struct device *dev)
 {
     int (*cb)(struct device *__dev);
 
     if (dev->type && dev->type->pm)
         cb = dev->type->pm->runtime_resume;
     else if (dev->class && dev->class->pm)
         cb = dev->class->pm->runtime_resume;
     else if (dev->bus && dev->bus->pm)
         cb = dev->bus->pm->runtime_resume;
     else
         cb = NULL;
 
     if (!cb && dev->driver && dev->driver->pm)
         cb = dev->driver->pm->runtime_resume;
 
     return cb ? cb(dev) : 0;
 }
 
 /**
  * genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
  * @dev: Device to suspend.
  *
  * Carry out a runtime suspend of a device under the assumption that its
  * pm_domain field points to the domain member of an object of type
  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
  */
 static int genpd_runtime_suspend(struct device *dev)
 {
     struct generic_pm_domain *genpd;
     bool (*suspend_ok)(struct device *__dev);
     struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
     struct gpd_timing_data *td = gpd_data->td;
     bool runtime_pm = pm_runtime_enabled(dev);
     ktime_t time_start = 0;
     s64 elapsed_ns;
     int ret;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     genpd = dev_to_genpd(dev);
     if (IS_ERR(genpd))
         return -EINVAL;
 
     /*
      * A runtime PM centric subsystem/driver may re-use the runtime PM
      * callbacks for other purposes than runtime PM. In those scenarios
      * runtime PM is disabled. Under these circumstances, we shall skip
      * validating/measuring the PM QoS latency.
      */
     suspend_ok = genpd->gov ? genpd->gov->suspend_ok : NULL;
     if (runtime_pm && suspend_ok && !suspend_ok(dev))
         return -EBUSY;
 
     /* Measure suspend latency. */
     if (td && runtime_pm)
         time_start = ktime_get();
 
     ret = __genpd_runtime_suspend(dev);
     if (ret)
         return ret;
 
     ret = genpd_stop_dev(genpd, dev);
     if (ret) {
         __genpd_runtime_resume(dev);
         return ret;
     }
 
     /* Update suspend latency value if the measured time exceeds it. */
     if (td && runtime_pm) {
         elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
         if (elapsed_ns > td->suspend_latency_ns) {
             td->suspend_latency_ns = elapsed_ns;
             dev_dbg(dev, "suspend latency exceeded, %lld ns\n",
                 elapsed_ns);
             genpd->gd->max_off_time_changed = true;
             td->constraint_changed = true;
         }
     }
 
     /*
      * If power.irq_safe is set, this routine may be run with
      * IRQs disabled, so suspend only if the PM domain also is irq_safe.
      */
     if (irq_safe_dev_in_sleep_domain(dev, genpd))
         return 0;
 
     genpd_lock(genpd);
     gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
     genpd_power_off(genpd, true, 0);
     genpd_unlock(genpd);
 
     return 0;
 }
 
 /**
  * genpd_runtime_resume - Resume a device belonging to I/O PM domain.
  * @dev: Device to resume.
  *
  * Carry out a runtime resume of a device under the assumption that its
  * pm_domain field points to the domain member of an object of type
  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
  */
 static int genpd_runtime_resume(struct device *dev)
 {
     struct generic_pm_domain *genpd;
     struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
     struct gpd_timing_data *td = gpd_data->td;
     bool timed = td && pm_runtime_enabled(dev);
     ktime_t time_start = 0;
     s64 elapsed_ns;
     int ret;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     genpd = dev_to_genpd(dev);
     if (IS_ERR(genpd))
         return -EINVAL;
 
     /*
      * As we don't power off a non IRQ safe domain, which holds
      * an IRQ safe device, we don't need to restore power to it.
      */
     if (irq_safe_dev_in_sleep_domain(dev, genpd))
         goto out;
 
     genpd_lock(genpd);
     ret = genpd_power_on(genpd, 0);
     if (!ret)
         genpd_restore_performance_state(dev, gpd_data->rpm_pstate);
     genpd_unlock(genpd);
 
     if (ret)
         return ret;
 
  out:
     /* Measure resume latency. */
     if (timed)
         time_start = ktime_get();
 
     ret = genpd_start_dev(genpd, dev);
     if (ret)
         goto err_poweroff;
 
     ret = __genpd_runtime_resume(dev);
     if (ret)
         goto err_stop;
 
     /* Update resume latency value if the measured time exceeds it. */
     if (timed) {
         elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
         if (elapsed_ns > td->resume_latency_ns) {
             td->resume_latency_ns = elapsed_ns;
             dev_dbg(dev, "resume latency exceeded, %lld ns\n",
                 elapsed_ns);
             genpd->gd->max_off_time_changed = true;
             td->constraint_changed = true;
         }
     }
 
     return 0;
 
 err_stop:
     genpd_stop_dev(genpd, dev);
 err_poweroff:
     if (!pm_runtime_is_irq_safe(dev) || genpd_is_irq_safe(genpd)) {
         genpd_lock(genpd);
         gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
         genpd_power_off(genpd, true, 0);
         genpd_unlock(genpd);
     }
 
     return ret;
 }
 
 static bool pd_ignore_unused;
 static int __init pd_ignore_unused_setup(char *__unused)
 {
     pd_ignore_unused = true;
     return 1;
 }
 __setup("pd_ignore_unused", pd_ignore_unused_setup);
 
 /**
  * genpd_power_off_unused - Power off all PM domains with no devices in use.
  */
 static int __init genpd_power_off_unused(void)
 {
     struct generic_pm_domain *genpd;
 
     if (pd_ignore_unused) {
         pr_warn("genpd: Not disabling unused power domains\n");
         return 0;
     }
 
     mutex_lock(&gpd_list_lock);
 
     list_for_each_entry(genpd, &gpd_list, gpd_list_node)
         genpd_queue_power_off_work(genpd);
 
     mutex_unlock(&gpd_list_lock);
 
     return 0;
 }
 late_initcall(genpd_power_off_unused);
 
 #ifdef CONFIG_PM_SLEEP
 
 /**
  * genpd_sync_power_off - Synchronously power off a PM domain and its parents.
  * @genpd: PM domain to power off, if possible.
  * @use_lock: use the lock.
  * @depth: nesting count for lockdep.
  *
  * Check if the given PM domain can be powered off (during system suspend or
  * hibernation) and do that if so.  Also, in that case propagate to its parents.
  *
  * This function is only called in "noirq" and "syscore" stages of system power
  * transitions. The "noirq" callbacks may be executed asynchronously, thus in
  * these cases the lock must be held.
  */
 static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock,
                  unsigned int depth)
 {
     struct gpd_link *link;
 
     if (!genpd_status_on(genpd) || genpd_is_always_on(genpd))
         return;
 
     if (genpd->suspended_count != genpd->device_count
         || atomic_read(&genpd->sd_count) > 0)
         return;
 
     /* Check that the children are in their deepest (powered-off) state. */
     list_for_each_entry(link, &genpd->parent_links, parent_node) {
         struct generic_pm_domain *child = link->child;
         if (child->state_idx < child->state_count - 1)
             return;
     }
 
     /* Choose the deepest state when suspending */
     genpd->state_idx = genpd->state_count - 1;
     if (_genpd_power_off(genpd, false))
         return;
 
     genpd->status = GENPD_STATE_OFF;
 
     list_for_each_entry(link, &genpd->child_links, child_node) {
         genpd_sd_counter_dec(link->parent);
 
         if (use_lock)
             genpd_lock_nested(link->parent, depth + 1);
 
         genpd_sync_power_off(link->parent, use_lock, depth + 1);
 
         if (use_lock)
             genpd_unlock(link->parent);
     }
 }
 
 /**
  * genpd_sync_power_on - Synchronously power on a PM domain and its parents.
  * @genpd: PM domain to power on.
  * @use_lock: use the lock.
  * @depth: nesting count for lockdep.
  *
  * This function is only called in "noirq" and "syscore" stages of system power
  * transitions. The "noirq" callbacks may be executed asynchronously, thus in
  * these cases the lock must be held.
  */
 static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock,
                 unsigned int depth)
 {
     struct gpd_link *link;
 
     if (genpd_status_on(genpd))
         return;
 
     list_for_each_entry(link, &genpd->child_links, child_node) {
         genpd_sd_counter_inc(link->parent);
 
         if (use_lock)
             genpd_lock_nested(link->parent, depth + 1);
 
         genpd_sync_power_on(link->parent, use_lock, depth + 1);
 
         if (use_lock)
             genpd_unlock(link->parent);
     }
 
     _genpd_power_on(genpd, false);
     genpd->status = GENPD_STATE_ON;
 }
 
 /**
  * genpd_prepare - Start power transition of a device in a PM domain.
  * @dev: Device to start the transition of.
  *
  * Start a power transition of a device (during a system-wide power transition)
  * under the assumption that its pm_domain field points to the domain member of
  * an object of type struct generic_pm_domain representing a PM domain
  * consisting of I/O devices.
  */
 static int genpd_prepare(struct device *dev)
 {
     struct generic_pm_domain *genpd;
     int ret;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     genpd = dev_to_genpd(dev);
     if (IS_ERR(genpd))
         return -EINVAL;
 
     genpd_lock(genpd);
 
     if (genpd->prepared_count++ == 0)
         genpd->suspended_count = 0;
 
     genpd_unlock(genpd);
 
     ret = pm_generic_prepare(dev);
     if (ret < 0) {
         genpd_lock(genpd);
 
         genpd->prepared_count--;
 
         genpd_unlock(genpd);
     }
 
     /* Never return 1, as genpd don't cope with the direct_complete path. */
     return ret >= 0 ? 0 : ret;
 }
 
 /**
  * genpd_finish_suspend - Completion of suspend or hibernation of device in an
  *   I/O pm domain.
  * @dev: Device to suspend.
  * @poweroff: Specifies if this is a poweroff_noirq or suspend_noirq callback.
  *
  * Stop the device and remove power from the domain if all devices in it have
  * been stopped.
  */
 static int genpd_finish_suspend(struct device *dev, bool poweroff)
 {
     struct generic_pm_domain *genpd;
     int ret = 0;
 
     genpd = dev_to_genpd(dev);
     if (IS_ERR(genpd))
         return -EINVAL;
 
     if (poweroff)
         ret = pm_generic_poweroff_noirq(dev);
     else
         ret = pm_generic_suspend_noirq(dev);
     if (ret)
         return ret;
 
     if (device_wakeup_path(dev) && genpd_is_active_wakeup(genpd))
         return 0;
 
     if (genpd->dev_ops.stop && genpd->dev_ops.start &&
         !pm_runtime_status_suspended(dev)) {
         ret = genpd_stop_dev(genpd, dev);
         if (ret) {
             if (poweroff)
                 pm_generic_restore_noirq(dev);
             else
                 pm_generic_resume_noirq(dev);
             return ret;
         }
     }
 
     genpd_lock(genpd);
     genpd->suspended_count++;
     genpd_sync_power_off(genpd, true, 0);
     genpd_unlock(genpd);
 
     return 0;
 }
 
 /**
  * genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
  * @dev: Device to suspend.
  *
  * Stop the device and remove power from the domain if all devices in it have
  * been stopped.
  */
 static int genpd_suspend_noirq(struct device *dev)
 {
     dev_dbg(dev, "%s()\n", __func__);
 
     return genpd_finish_suspend(dev, false);
 }
 
 /**
  * genpd_resume_noirq - Start of resume of device in an I/O PM domain.
  * @dev: Device to resume.
  *
  * Restore power to the device's PM domain, if necessary, and start the device.
  */
 static int genpd_resume_noirq(struct device *dev)
 {
     struct generic_pm_domain *genpd;
     int ret;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     genpd = dev_to_genpd(dev);
     if (IS_ERR(genpd))
         return -EINVAL;
 
     if (device_wakeup_path(dev) && genpd_is_active_wakeup(genpd))
         return pm_generic_resume_noirq(dev);
 
     genpd_lock(genpd);
     genpd_sync_power_on(genpd, true, 0);
     genpd->suspended_count--;
     genpd_unlock(genpd);
 
     if (genpd->dev_ops.stop && genpd->dev_ops.start &&
         !pm_runtime_status_suspended(dev)) {
         ret = genpd_start_dev(genpd, dev);
         if (ret)
             return ret;
     }
 
     return pm_generic_resume_noirq(dev);
 }
 
 /**
  * genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
  * @dev: Device to freeze.
  *
  * Carry out a late freeze of a device under the assumption that its
  * pm_domain field points to the domain member of an object of type
  * struct generic_pm_domain representing a power domain consisting of I/O
  * devices.
  */
 static int genpd_freeze_noirq(struct device *dev)
 {
     const struct generic_pm_domain *genpd;
     int ret = 0;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     genpd = dev_to_genpd(dev);
     if (IS_ERR(genpd))
         return -EINVAL;
 
     ret = pm_generic_freeze_noirq(dev);
     if (ret)
         return ret;
 
     if (genpd->dev_ops.stop && genpd->dev_ops.start &&
         !pm_runtime_status_suspended(dev))
         ret = genpd_stop_dev(genpd, dev);
 
     return ret;
 }
 
 /**
  * genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
  * @dev: Device to thaw.
  *
  * Start the device, unless power has been removed from the domain already
  * before the system transition.
  */
 static int genpd_thaw_noirq(struct device *dev)
 {
     const struct generic_pm_domain *genpd;
     int ret = 0;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     genpd = dev_to_genpd(dev);
     if (IS_ERR(genpd))
         return -EINVAL;
 
     if (genpd->dev_ops.stop && genpd->dev_ops.start &&
         !pm_runtime_status_suspended(dev)) {
         ret = genpd_start_dev(genpd, dev);
         if (ret)
             return ret;
     }
 
     return pm_generic_thaw_noirq(dev);
 }
 
 /**
  * genpd_poweroff_noirq - Completion of hibernation of device in an
  *   I/O PM domain.
  * @dev: Device to poweroff.
  *
  * Stop the device and remove power from the domain if all devices in it have
  * been stopped.
  */
 static int genpd_poweroff_noirq(struct device *dev)
 {
     dev_dbg(dev, "%s()\n", __func__);
 
     return genpd_finish_suspend(dev, true);
 }
 
 /**
  * genpd_restore_noirq - Start of restore of device in an I/O PM domain.
  * @dev: Device to resume.
  *
  * Make sure the domain will be in the same power state as before the
  * hibernation the system is resuming from and start the device if necessary.
  */
 static int genpd_restore_noirq(struct device *dev)
 {
     struct generic_pm_domain *genpd;
     int ret = 0;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     genpd = dev_to_genpd(dev);
     if (IS_ERR(genpd))
         return -EINVAL;
 
     /*
      * At this point suspended_count == 0 means we are being run for the
      * first time for the given domain in the present cycle.
      */
     genpd_lock(genpd);
     if (genpd->suspended_count++ == 0) {
         /*
          * The boot kernel might put the domain into arbitrary state,
          * so make it appear as powered off to genpd_sync_power_on(),
          * so that it tries to power it on in case it was really off.
          */
         genpd->status = GENPD_STATE_OFF;
     }
 
     genpd_sync_power_on(genpd, true, 0);
     genpd_unlock(genpd);
 
     if (genpd->dev_ops.stop && genpd->dev_ops.start &&
         !pm_runtime_status_suspended(dev)) {
         ret = genpd_start_dev(genpd, dev);
         if (ret)
             return ret;
     }
 
     return pm_generic_restore_noirq(dev);
 }
 
 /**
  * genpd_complete - Complete power transition of a device in a power domain.
  * @dev: Device to complete the transition of.
  *
  * Complete a power transition of a device (during a system-wide power
  * transition) under the assumption that its pm_domain field points to the
  * domain member of an object of type struct generic_pm_domain representing
  * a power domain consisting of I/O devices.
  */
 static void genpd_complete(struct device *dev)
 {
     struct generic_pm_domain *genpd;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     genpd = dev_to_genpd(dev);
     if (IS_ERR(genpd))
         return;
 
     pm_generic_complete(dev);
 
     genpd_lock(genpd);
 
     genpd->prepared_count--;
     if (!genpd->prepared_count)
         genpd_queue_power_off_work(genpd);
 
     genpd_unlock(genpd);
 }
 
 static void genpd_switch_state(struct device *dev, bool suspend)
 {
     struct generic_pm_domain *genpd;
     bool use_lock;
 
     genpd = dev_to_genpd_safe(dev);
     if (!genpd)
         return;
 
     use_lock = genpd_is_irq_safe(genpd);
 
     if (use_lock)
         genpd_lock(genpd);
 
     if (suspend) {
         genpd->suspended_count++;
         genpd_sync_power_off(genpd, use_lock, 0);
     } else {
         genpd_sync_power_on(genpd, use_lock, 0);
         genpd->suspended_count--;
     }
 
     if (use_lock)
         genpd_unlock(genpd);
 }
 
 /**
  * dev_pm_genpd_suspend - Synchronously try to suspend the genpd for @dev
  * @dev: The device that is attached to the genpd, that can be suspended.
  *
  * This routine should typically be called for a device that needs to be
  * suspended during the syscore suspend phase. It may also be called during
  * suspend-to-idle to suspend a corresponding CPU device that is attached to a
  * genpd.
  */
 void dev_pm_genpd_suspend(struct device *dev)
 {
     genpd_switch_state(dev, true);
 }
 EXPORT_SYMBOL_GPL(dev_pm_genpd_suspend);
 
 /**
  * dev_pm_genpd_resume - Synchronously try to resume the genpd for @dev
  * @dev: The device that is attached to the genpd, which needs to be resumed.
  *
  * This routine should typically be called for a device that needs to be resumed
  * during the syscore resume phase. It may also be called during suspend-to-idle
  * to resume a corresponding CPU device that is attached to a genpd.
  */
 void dev_pm_genpd_resume(struct device *dev)
 {
     genpd_switch_state(dev, false);
 }
 EXPORT_SYMBOL_GPL(dev_pm_genpd_resume);
 
 #else /* !CONFIG_PM_SLEEP */
 
 #define genpd_prepare       NULL
 #define genpd_suspend_noirq NULL
 #define genpd_resume_noirq  NULL
 #define genpd_freeze_noirq  NULL
 #define genpd_thaw_noirq    NULL
 #define genpd_poweroff_noirq    NULL
 #define genpd_restore_noirq NULL
 #define genpd_complete      NULL
 
 #endif /* CONFIG_PM_SLEEP */
 
 static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
                                bool has_governor)
 {
     struct generic_pm_domain_data *gpd_data;
     struct gpd_timing_data *td;
     int ret;
 
     ret = dev_pm_get_subsys_data(dev);
     if (ret)
         return ERR_PTR(ret);
 
     gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
     if (!gpd_data) {
         ret = -ENOMEM;
         goto err_put;
     }
 
     gpd_data->base.dev = dev;
     gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
 
     /* Allocate data used by a governor. */
     if (has_governor) {
         td = kzalloc(sizeof(*td), GFP_KERNEL);
         if (!td) {
             ret = -ENOMEM;
             goto err_free;
         }
 
         td->constraint_changed = true;
         td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS;
         td->next_wakeup = KTIME_MAX;
         gpd_data->td = td;
     }
 
     spin_lock_irq(&dev->power.lock);
 
     if (dev->power.subsys_data->domain_data)
         ret = -EINVAL;
     else
         dev->power.subsys_data->domain_data = &gpd_data->base;
 
     spin_unlock_irq(&dev->power.lock);
 
     if (ret)
         goto err_free;
 
     return gpd_data;
 
  err_free:
     kfree(gpd_data->td);
     kfree(gpd_data);
  err_put:
     dev_pm_put_subsys_data(dev);
     return ERR_PTR(ret);
 }
 
 static void genpd_free_dev_data(struct device *dev,
                 struct generic_pm_domain_data *gpd_data)
 {
     spin_lock_irq(&dev->power.lock);
 
     dev->power.subsys_data->domain_data = NULL;
 
     spin_unlock_irq(&dev->power.lock);
 
     kfree(gpd_data->td);
     kfree(gpd_data);
     dev_pm_put_subsys_data(dev);
 }
 
 static void genpd_update_cpumask(struct generic_pm_domain *genpd,
                  int cpu, bool set, unsigned int depth)
 {
     struct gpd_link *link;
 
     if (!genpd_is_cpu_domain(genpd))
         return;
 
     list_for_each_entry(link, &genpd->child_links, child_node) {
         struct generic_pm_domain *parent = link->parent;
 
         genpd_lock_nested(parent, depth + 1);
         genpd_update_cpumask(parent, cpu, set, depth + 1);
         genpd_unlock(parent);
     }
 
     if (set)
         cpumask_set_cpu(cpu, genpd->cpus);
     else
         cpumask_clear_cpu(cpu, genpd->cpus);
 }
 
 static void genpd_set_cpumask(struct generic_pm_domain *genpd, int cpu)
 {
     if (cpu >= 0)
         genpd_update_cpumask(genpd, cpu, true, 0);
 }
 
 static void genpd_clear_cpumask(struct generic_pm_domain *genpd, int cpu)
 {
     if (cpu >= 0)
         genpd_update_cpumask(genpd, cpu, false, 0);
 }
 
 static int genpd_get_cpu(struct generic_pm_domain *genpd, struct device *dev)
 {
     int cpu;
 
     if (!genpd_is_cpu_domain(genpd))
         return -1;
 
     for_each_possible_cpu(cpu) {
         if (get_cpu_device(cpu) == dev)
             return cpu;
     }
 
     return -1;
 }
 
 static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
                 struct device *base_dev)
 {
     struct genpd_governor_data *gd = genpd->gd;
     struct generic_pm_domain_data *gpd_data;
     int ret;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
         return -EINVAL;
 
     gpd_data = genpd_alloc_dev_data(dev, gd);
     if (IS_ERR(gpd_data))
         return PTR_ERR(gpd_data);
 
     gpd_data->cpu = genpd_get_cpu(genpd, base_dev);
 
     ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0;
     if (ret)
         goto out;
 
     genpd_lock(genpd);
 
     genpd_set_cpumask(genpd, gpd_data->cpu);
     dev_pm_domain_set(dev, &genpd->domain);
 
     genpd->device_count++;
     if (gd)
         gd->max_off_time_changed = true;
 
     list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
 
     genpd_unlock(genpd);
  out:
     if (ret)
         genpd_free_dev_data(dev, gpd_data);
     else
         dev_pm_qos_add_notifier(dev, &gpd_data->nb,
                     DEV_PM_QOS_RESUME_LATENCY);
 
     return ret;
 }
 
 /**
  * pm_genpd_add_device - Add a device to an I/O PM domain.
  * @genpd: PM domain to add the device to.
  * @dev: Device to be added.
  */
 int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
 {
     int ret;
 
     mutex_lock(&gpd_list_lock);
     ret = genpd_add_device(genpd, dev, dev);
     mutex_unlock(&gpd_list_lock);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(pm_genpd_add_device);
 
 static int genpd_remove_device(struct generic_pm_domain *genpd,
                    struct device *dev)
 {
     struct generic_pm_domain_data *gpd_data;
     struct pm_domain_data *pdd;
     int ret = 0;
 
     dev_dbg(dev, "%s()\n", __func__);
 
     pdd = dev->power.subsys_data->domain_data;
     gpd_data = to_gpd_data(pdd);
     dev_pm_qos_remove_notifier(dev, &gpd_data->nb,
                    DEV_PM_QOS_RESUME_LATENCY);
 
     genpd_lock(genpd);
 
     if (genpd->prepared_count > 0) {
         ret = -EAGAIN;
         goto out;
     }
 
     genpd->device_count--;
     if (genpd->gd)
         genpd->gd->max_off_time_changed = true;
 
     genpd_clear_cpumask(genpd, gpd_data->cpu);
     dev_pm_domain_set(dev, NULL);
 
     list_del_init(&pdd->list_node);
 
     genpd_unlock(genpd);
 
     if (genpd->detach_dev)
         genpd->detach_dev(genpd, dev);
 
     genpd_free_dev_data(dev, gpd_data);
 
     return 0;
 
  out:
     genpd_unlock(genpd);
     dev_pm_qos_add_notifier(dev, &gpd_data->nb, DEV_PM_QOS_RESUME_LATENCY);
 
     return ret;
 }
 
 /**
  * pm_genpd_remove_device - Remove a device from an I/O PM domain.
  * @dev: Device to be removed.
  */
 int pm_genpd_remove_device(struct device *dev)
 {
     struct generic_pm_domain *genpd = dev_to_genpd_safe(dev);
 
     if (!genpd)
         return -EINVAL;
 
     return genpd_remove_device(genpd, dev);
 }
 EXPORT_SYMBOL_GPL(pm_genpd_remove_device);
 
 /**
  * dev_pm_genpd_add_notifier - Add a genpd power on/off notifier for @dev
  *
  * @dev: Device that should be associated with the notifier
  * @nb: The notifier block to register
  *
  * Users may call this function to add a genpd power on/off notifier for an
  * attached @dev. Only one notifier per device is allowed. The notifier is
  * sent when genpd is powering on/off the PM domain.
  *
  * It is assumed that the user guarantee that the genpd wouldn't be detached
  * while this routine is getting called.
  *
  * Returns 0 on success and negative error values on failures.
  */
 int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb)
 {
     struct generic_pm_domain *genpd;
     struct generic_pm_domain_data *gpd_data;
     int ret;
 
     genpd = dev_to_genpd_safe(dev);
     if (!genpd)
         return -ENODEV;
 
     if (WARN_ON(!dev->power.subsys_data ||
              !dev->power.subsys_data->domain_data))
         return -EINVAL;
 
     gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
     if (gpd_data->power_nb)
         return -EEXIST;
 
     genpd_lock(genpd);
     ret = raw_notifier_chain_register(&genpd->power_notifiers, nb);
     genpd_unlock(genpd);
 
     if (ret) {
         dev_warn(dev, "failed to add notifier for PM domain %s\n",
              genpd->name);
         return ret;
     }
 
     gpd_data->power_nb = nb;
     return 0;
 }
 EXPORT_SYMBOL_GPL(dev_pm_genpd_add_notifier);
 
 /**
  * dev_pm_genpd_remove_notifier - Remove a genpd power on/off notifier for @dev
  *
  * @dev: Device that is associated with the notifier
  *
  * Users may call this function to remove a genpd power on/off notifier for an
  * attached @dev.
  *
  * It is assumed that the user guarantee that the genpd wouldn't be detached
  * while this routine is getting called.
  *
  * Returns 0 on success and negative error values on failures.
  */
 int dev_pm_genpd_remove_notifier(struct device *dev)
 {
     struct generic_pm_domain *genpd;
     struct generic_pm_domain_data *gpd_data;
     int ret;
 
     genpd = dev_to_genpd_safe(dev);
     if (!genpd)
         return -ENODEV;
 
     if (WARN_ON(!dev->power.subsys_data ||
              !dev->power.subsys_data->domain_data))
         return -EINVAL;
 
     gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
     if (!gpd_data->power_nb)
         return -ENODEV;
 
     genpd_lock(genpd);
     ret = raw_notifier_chain_unregister(&genpd->power_notifiers,
                         gpd_data->power_nb);
     genpd_unlock(genpd);
 
     if (ret) {
         dev_warn(dev, "failed to remove notifier for PM domain %s\n",
              genpd->name);
         return ret;
     }
 
     gpd_data->power_nb = NULL;
     return 0;
 }
 EXPORT_SYMBOL_GPL(dev_pm_genpd_remove_notifier);
 
 static int genpd_add_subdomain(struct generic_pm_domain *genpd,
                    struct generic_pm_domain *subdomain)
 {
     struct gpd_link *link, *itr;
     int ret = 0;
 
     if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
         || genpd == subdomain)
         return -EINVAL;
 
     /*
      * If the domain can be powered on/off in an IRQ safe
      * context, ensure that the subdomain can also be
      * powered on/off in that context.
      */
     if (!genpd_is_irq_safe(genpd) && genpd_is_irq_safe(subdomain)) {
         WARN(1, "Parent %s of subdomain %s must be IRQ safe\n",
                 genpd->name, subdomain->name);
         return -EINVAL;
     }
 
     link = kzalloc(sizeof(*link), GFP_KERNEL);
     if (!link)
         return -ENOMEM;
 
     genpd_lock(subdomain);
     genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING);
 
     if (!genpd_status_on(genpd) && genpd_status_on(subdomain)) {
         ret = -EINVAL;
         goto out;
     }
 
     list_for_each_entry(itr, &genpd->parent_links, parent_node) {
         if (itr->child == subdomain && itr->parent == genpd) {
             ret = -EINVAL;
             goto out;
         }
     }
 
     link->parent = genpd;
     list_add_tail(&link->parent_node, &genpd->parent_links);
     link->child = subdomain;
     list_add_tail(&link->child_node, &subdomain->child_links);
     if (genpd_status_on(subdomain))
         genpd_sd_counter_inc(genpd);
 
  out:
     genpd_unlock(genpd);
     genpd_unlock(subdomain);
     if (ret)
         kfree(link);
     return ret;
 }
 
 /**
  * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
  * @genpd: Leader PM domain to add the subdomain to.
  * @subdomain: Subdomain to be added.
  */
 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
                struct generic_pm_domain *subdomain)
 {
     int ret;
 
     mutex_lock(&gpd_list_lock);
     ret = genpd_add_subdomain(genpd, subdomain);
     mutex_unlock(&gpd_list_lock);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(pm_genpd_add_subdomain);
 
 /**
  * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
  * @genpd: Leader PM domain to remove the subdomain from.
  * @subdomain: Subdomain to be removed.
  */
 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
                   struct generic_pm_domain *subdomain)
 {
     struct gpd_link *l, *link;
     int ret = -EINVAL;
 
     if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
         return -EINVAL;
 
     genpd_lock(subdomain);
     genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING);
 
     if (!list_empty(&subdomain->parent_links) || subdomain->device_count) {
         pr_warn("%s: unable to remove subdomain %s\n",
             genpd->name, subdomain->name);
         ret = -EBUSY;
         goto out;
     }
 
     list_for_each_entry_safe(link, l, &genpd->parent_links, parent_node) {
         if (link->child != subdomain)
             continue;
 
         list_del(&link->parent_node);
         list_del(&link->child_node);
         kfree(link);
         if (genpd_status_on(subdomain))
             genpd_sd_counter_dec(genpd);
 
         ret = 0;
         break;
     }
 
 out:
     genpd_unlock(genpd);
     genpd_unlock(subdomain);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);
 
 static void genpd_free_default_power_state(struct genpd_power_state *states,
                        unsigned int state_count)
 {
     kfree(states);
 }
 
 static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
 {
     struct genpd_power_state *state;
 
     state = kzalloc(sizeof(*state), GFP_KERNEL);
     if (!state)
         return -ENOMEM;
 
     genpd->states = state;
     genpd->state_count = 1;
     genpd->free_states = genpd_free_default_power_state;
 
     return 0;
 }
 
 static int genpd_alloc_data(struct generic_pm_domain *genpd)
 {
     struct genpd_governor_data *gd = NULL;
     int ret;
 
     if (genpd_is_cpu_domain(genpd) &&
         !zalloc_cpumask_var(&genpd->cpus, GFP_KERNEL))
         return -ENOMEM;
 
     if (genpd->gov) {
         gd = kzalloc(sizeof(*gd), GFP_KERNEL);
         if (!gd) {
             ret = -ENOMEM;
             goto free;
         }
 
         gd->max_off_time_ns = -1;
         gd->max_off_time_changed = true;
         gd->next_wakeup = KTIME_MAX;
     }
 
     /* Use only one "off" state if there were no states declared */
     if (genpd->state_count == 0) {
         ret = genpd_set_default_power_state(genpd);
         if (ret)
             goto free;
     }
 
     genpd->gd = gd;
     return 0;
 
 free:
     if (genpd_is_cpu_domain(genpd))
         free_cpumask_var(genpd->cpus);
     kfree(gd);
     return ret;
 }
 
 static void genpd_free_data(struct generic_pm_domain *genpd)
 {
     if (genpd_is_cpu_domain(genpd))
         free_cpumask_var(genpd->cpus);
     if (genpd->free_states)
         genpd->free_states(genpd->states, genpd->state_count);
     kfree(genpd->gd);
 }
 
 static void genpd_lock_init(struct generic_pm_domain *genpd)
 {
     if (genpd->flags & GENPD_FLAG_IRQ_SAFE) {
         spin_lock_init(&genpd->slock);
         genpd->lock_ops = &genpd_spin_ops;
     } else {
         mutex_init(&genpd->mlock);
         genpd->lock_ops = &genpd_mtx_ops;
     }
 }
 
 /**
  * pm_genpd_init - Initialize a generic I/O PM domain object.
  * @genpd: PM domain object to initialize.
  * @gov: PM domain governor to associate with the domain (may be NULL).
  * @is_off: Initial value of the domain's power_is_off field.
  *
  * Returns 0 on successful initialization, else a negative error code.
  */
 int pm_genpd_init(struct generic_pm_domain *genpd,
           struct dev_power_governor *gov, bool is_off)
 {
     int ret;
 
     if (IS_ERR_OR_NULL(genpd))
         return -EINVAL;
 
     INIT_LIST_HEAD(&genpd->parent_links);
     INIT_LIST_HEAD(&genpd->child_links);
     INIT_LIST_HEAD(&genpd->dev_list);
     RAW_INIT_NOTIFIER_HEAD(&genpd->power_notifiers);
     genpd_lock_init(genpd);
     genpd->gov = gov;
     INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
     atomic_set(&genpd->sd_count, 0);
     genpd->status = is_off ? GENPD_STATE_OFF : GENPD_STATE_ON;
     genpd->device_count = 0;
     genpd->provider = NULL;
     genpd->has_provider = false;
     genpd->accounting_time = ktime_get_mono_fast_ns();
     genpd->domain.ops.runtime_suspend = genpd_runtime_suspend;
     genpd->domain.ops.runtime_resume = genpd_runtime_resume;
     genpd->domain.ops.prepare = genpd_prepare;
     genpd->domain.ops.suspend_noirq = genpd_suspend_noirq;
     genpd->domain.ops.resume_noirq = genpd_resume_noirq;
     genpd->domain.ops.freeze_noirq = genpd_freeze_noirq;
     genpd->domain.ops.thaw_noirq = genpd_thaw_noirq;
     genpd->domain.ops.poweroff_noirq = genpd_poweroff_noirq;
     genpd->domain.ops.restore_noirq = genpd_restore_noirq;
     genpd->domain.ops.complete = genpd_complete;
     genpd->domain.start = genpd_dev_pm_start;
 
     if (genpd->flags & GENPD_FLAG_PM_CLK) {
         genpd->dev_ops.stop = pm_clk_suspend;
         genpd->dev_ops.start = pm_clk_resume;
     }
 
     /* The always-on governor works better with the corresponding flag. */
     if (gov == &pm_domain_always_on_gov)
         genpd->flags |= GENPD_FLAG_RPM_ALWAYS_ON;
 
     /* Always-on domains must be powered on at initialization. */
     if ((genpd_is_always_on(genpd) || genpd_is_rpm_always_on(genpd)) &&
             !genpd_status_on(genpd))
         return -EINVAL;
 
     /* Multiple states but no governor doesn't make sense. */
     if (!gov && genpd->state_count > 1)
         pr_warn("%s: no governor for states\n", genpd->name);
 
     ret = genpd_alloc_data(genpd);
     if (ret)
         return ret;
 
     device_initialize(&genpd->dev);
     dev_set_name(&genpd->dev, "%s", genpd->name);
 
     mutex_lock(&gpd_list_lock);
     list_add(&genpd->gpd_list_node, &gpd_list);
     mutex_unlock(&gpd_list_lock);
     genpd_debug_add(genpd);
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(pm_genpd_init);
 
 static int genpd_remove(struct generic_pm_domain *genpd)
 {
     struct gpd_link *l, *link;
 
     if (IS_ERR_OR_NULL(genpd))
         return -EINVAL;
 
     genpd_lock(genpd);
 
     if (genpd->has_provider) {
         genpd_unlock(genpd);
         pr_err("Provider present, unable to remove %s\n", genpd->name);
         return -EBUSY;
     }
 
     if (!list_empty(&genpd->parent_links) || genpd->device_count) {
         genpd_unlock(genpd);
         pr_err("%s: unable to remove %s\n", __func__, genpd->name);
         return -EBUSY;
     }
 
     list_for_each_entry_safe(link, l, &genpd->child_links, child_node) {
         list_del(&link->parent_node);
         list_del(&link->child_node);
         kfree(link);
     }
 
     list_del(&genpd->gpd_list_node);
     genpd_unlock(genpd);
     genpd_debug_remove(genpd);
     cancel_work_sync(&genpd->power_off_work);
     genpd_free_data(genpd);
 
     pr_debug("%s: removed %s\n", __func__, genpd->name);
 
     return 0;
 }
 
 /**
  * pm_genpd_remove - Remove a generic I/O PM domain
  * @genpd: Pointer to PM domain that is to be removed.
  *
  * To remove the PM domain, this function:
  *  - Removes the PM domain as a subdomain to any parent domains,
  *    if it was added.
  *  - Removes the PM domain from the list of registered PM domains.
  *
  * The PM domain will only be removed, if the associated provider has
  * been removed, it is not a parent to any other PM domain and has no
  * devices associated with it.
  */
 int pm_genpd_remove(struct generic_pm_domain *genpd)
 {
     int ret;
 
     mutex_lock(&gpd_list_lock);
     ret = genpd_remove(genpd);
     mutex_unlock(&gpd_list_lock);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(pm_genpd_remove);
 
 #ifdef CONFIG_PM_GENERIC_DOMAINS_OF
 
 /*
  * Device Tree based PM domain providers.
  *
  * The code below implements generic device tree based PM domain providers that
  * bind device tree nodes with generic PM domains registered in the system.
  *
  * Any driver that registers generic PM domains and needs to support binding of
  * devices to these domains is supposed to register a PM domain provider, which
  * maps a PM domain specifier retrieved from the device tree to a PM domain.
  *
  * Two simple mapping functions have been provided for convenience:
  *  - genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
  *  - genpd_xlate_onecell() for mapping of multiple PM domains per node by
  *    index.
  */
 
 /**
  * struct of_genpd_provider - PM domain provider registration structure
  * @link: Entry in global list of PM domain providers
  * @node: Pointer to device tree node of PM domain provider
  * @xlate: Provider-specific xlate callback mapping a set of specifier cells
  *         into a PM domain.
  * @data: context pointer to be passed into @xlate callback
  */
 struct of_genpd_provider {
     struct list_head link;
     struct device_node *node;
     genpd_xlate_t xlate;
     void *data;
 };
 
 /* List of registered PM domain providers. */
 static LIST_HEAD(of_genpd_providers);
 /* Mutex to protect the list above. */
 static DEFINE_MUTEX(of_genpd_mutex);
 
 /**
  * genpd_xlate_simple() - Xlate function for direct node-domain mapping
  * @genpdspec: OF phandle args to map into a PM domain
  * @data: xlate function private data - pointer to struct generic_pm_domain
  *
  * This is a generic xlate function that can be used to model PM domains that
  * have their own device tree nodes. The private data of xlate function needs
  * to be a valid pointer to struct generic_pm_domain.
  */
 static struct generic_pm_domain *genpd_xlate_simple(
                     struct of_phandle_args *genpdspec,
                     void *data)
 {
     return data;
 }
 
 /**
  * genpd_xlate_onecell() - Xlate function using a single index.
  * @genpdspec: OF phandle args to map into a PM domain
  * @data: xlate function private data - pointer to struct genpd_onecell_data
  *
  * This is a generic xlate function that can be used to model simple PM domain
  * controllers that have one device tree node and provide multiple PM domains.
  * A single cell is used as an index into an array of PM domains specified in
  * the genpd_onecell_data struct when registering the provider.
  */
 static struct generic_pm_domain *genpd_xlate_onecell(
                     struct of_phandle_args *genpdspec,
                     void *data)
 {
     struct genpd_onecell_data *genpd_data = data;
     unsigned int idx = genpdspec->args[0];
 
     if (genpdspec->args_count != 1)
         return ERR_PTR(-EINVAL);
 
     if (idx >= genpd_data->num_domains) {
         pr_err("%s: invalid domain index %u\n", __func__, idx);
         return ERR_PTR(-EINVAL);
     }
 
     if (!genpd_data->domains[idx])
         return ERR_PTR(-ENOENT);
 
     return genpd_data->domains[idx];
 }
 
 /**
  * genpd_add_provider() - Register a PM domain provider for a node
  * @np: Device node pointer associated with the PM domain provider.
  * @xlate: Callback for decoding PM domain from phandle arguments.
  * @data: Context pointer for @xlate callback.
  */
 static int genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
                   void *data)
 {
     struct of_genpd_provider *cp;
 
     cp = kzalloc(sizeof(*cp), GFP_KERNEL);
     if (!cp)
         return -ENOMEM;
 
     cp->node = of_node_get(np);
     cp->data = data;
     cp->xlate = xlate;
     fwnode_dev_initialized(&np->fwnode, true);
 
     mutex_lock(&of_genpd_mutex);
     list_add(&cp->link, &of_genpd_providers);
     mutex_unlock(&of_genpd_mutex);
     pr_debug("Added domain provider from %pOF\n", np);
 
     return 0;
 }
 
 static bool genpd_present(const struct generic_pm_domain *genpd)
 {
     bool ret = false;
     const struct generic_pm_domain *gpd;
 
     mutex_lock(&gpd_list_lock);
     list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
         if (gpd == genpd) {
             ret = true;
             break;
         }
     }
     mutex_unlock(&gpd_list_lock);
 
     return ret;
 }
 
 /**
  * of_genpd_add_provider_simple() - Register a simple PM domain provider
  * @np: Device node pointer associated with the PM domain provider.
  * @genpd: Pointer to PM domain associated with the PM domain provider.
  */
 int of_genpd_add_provider_simple(struct device_node *np,
                  struct generic_pm_domain *genpd)
 {
     int ret;
 
     if (!np || !genpd)
         return -EINVAL;
 
     if (!genpd_present(genpd))
         return -EINVAL;
 
     genpd->dev.of_node = np;
 
     /* Parse genpd OPP table */
     if (genpd->set_performance_state) {
         ret = dev_pm_opp_of_add_table(&genpd->dev);
         if (ret)
             return dev_err_probe(&genpd->dev, ret, "Failed to add OPP table\n");
 
         /*
          * Save table for faster processing while setting performance
          * state.
          */
         genpd->opp_table = dev_pm_opp_get_opp_table(&genpd->dev);
         WARN_ON(IS_ERR(genpd->opp_table));
     }
 
     ret = genpd_add_provider(np, genpd_xlate_simple, genpd);
     if (ret) {
         if (genpd->set_performance_state) {
             dev_pm_opp_put_opp_table(genpd->opp_table);
             dev_pm_opp_of_remove_table(&genpd->dev);
         }
 
         return ret;
     }
 
     genpd->provider = &np->fwnode;
     genpd->has_provider = true;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(of_genpd_add_provider_simple);
 
 /**
  * of_genpd_add_provider_onecell() - Register a onecell PM domain provider
  * @np: Device node pointer associated with the PM domain provider.
  * @data: Pointer to the data associated with the PM domain provider.
  */
 int of_genpd_add_provider_onecell(struct device_node *np,
                   struct genpd_onecell_data *data)
 {
     struct generic_pm_domain *genpd;
     unsigned int i;
     int ret = -EINVAL;
 
     if (!np || !data)
         return -EINVAL;
 
     if (!data->xlate)
         data->xlate = genpd_xlate_onecell;
 
     for (i = 0; i < data->num_domains; i++) {
         genpd = data->domains[i];
 
         if (!genpd)
             continue;
         if (!genpd_present(genpd))
             goto error;
 
         genpd->dev.of_node = np;
 
         /* Parse genpd OPP table */
         if (genpd->set_performance_state) {
             ret = dev_pm_opp_of_add_table_indexed(&genpd->dev, i);
             if (ret) {
                 dev_err_probe(&genpd->dev, ret,
                           "Failed to add OPP table for index %d\n", i);
                 goto error;
             }
 
             /*
              * Save table for faster processing while setting
              * performance state.
              */
             genpd->opp_table = dev_pm_opp_get_opp_table(&genpd->dev);
             WARN_ON(IS_ERR(genpd->opp_table));
         }
 
         genpd->provider = &np->fwnode;
         genpd->has_provider = true;
     }
 
     ret = genpd_add_provider(np, data->xlate, data);
     if (ret < 0)
         goto error;
 
     return 0;
 
 error:
     while (i--) {
         genpd = data->domains[i];
 
         if (!genpd)
             continue;
 
         genpd->provider = NULL;
         genpd->has_provider = false;
 
         if (genpd->set_performance_state) {
             dev_pm_opp_put_opp_table(genpd->opp_table);
             dev_pm_opp_of_remove_table(&genpd->dev);
         }
     }
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(of_genpd_add_provider_onecell);
 
 /**
  * of_genpd_del_provider() - Remove a previously registered PM domain provider
  * @np: Device node pointer associated with the PM domain provider
  */
 void of_genpd_del_provider(struct device_node *np)
 {
     struct of_genpd_provider *cp, *tmp;
     struct generic_pm_domain *gpd;
 
     mutex_lock(&gpd_list_lock);
     mutex_lock(&of_genpd_mutex);
     list_for_each_entry_safe(cp, tmp, &of_genpd_providers, link) {
         if (cp->node == np) {
             /*
              * For each PM domain associated with the
              * provider, set the 'has_provider' to false
              * so that the PM domain can be safely removed.
              */
             list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
                 if (gpd->provider == &np->fwnode) {
                     gpd->has_provider = false;
 
                     if (!gpd->set_performance_state)
                         continue;
 
                     dev_pm_opp_put_opp_table(gpd->opp_table);
                     dev_pm_opp_of_remove_table(&gpd->dev);
                 }
             }
 
             fwnode_dev_initialized(&cp->node->fwnode, false);
             list_del(&cp->link);
             of_node_put(cp->node);
             kfree(cp);
             break;
         }
     }
     mutex_unlock(&of_genpd_mutex);
     mutex_unlock(&gpd_list_lock);
 }
 EXPORT_SYMBOL_GPL(of_genpd_del_provider);
 
 /**
  * genpd_get_from_provider() - Look-up PM domain
  * @genpdspec: OF phandle args to use for look-up
  *
  * Looks for a PM domain provider under the node specified by @genpdspec and if
  * found, uses xlate function of the provider to map phandle args to a PM
  * domain.
  *
  * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
  * on failure.
  */
 static struct generic_pm_domain *genpd_get_from_provider(
                     struct of_phandle_args *genpdspec)
 {
     struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
     struct of_genpd_provider *provider;
 
     if (!genpdspec)
         return ERR_PTR(-EINVAL);
 
     mutex_lock(&of_genpd_mutex);
 
     /* Check if we have such a provider in our array */
     list_for_each_entry(provider, &of_genpd_providers, link) {
         if (provider->node == genpdspec->np)
             genpd = provider->xlate(genpdspec, provider->data);
         if (!IS_ERR(genpd))
             break;
     }
 
     mutex_unlock(&of_genpd_mutex);
 
     return genpd;
 }
 
 /**
  * of_genpd_add_device() - Add a device to an I/O PM domain
  * @genpdspec: OF phandle args to use for look-up PM domain
  * @dev: Device to be added.
  *
  * Looks-up an I/O PM domain based upon phandle args provided and adds
  * the device to the PM domain. Returns a negative error code on failure.
  */
 int of_genpd_add_device(struct of_phandle_args *genpdspec, struct device *dev)
 {
     struct generic_pm_domain *genpd;
     int ret;
 
     mutex_lock(&gpd_list_lock);
 
     genpd = genpd_get_from_provider(genpdspec);
     if (IS_ERR(genpd)) {
         ret = PTR_ERR(genpd);
         goto out;
     }
 
     ret = genpd_add_device(genpd, dev, dev);
 
 out:
     mutex_unlock(&gpd_list_lock);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(of_genpd_add_device);
 
 /**
  * of_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
  * @parent_spec: OF phandle args to use for parent PM domain look-up
  * @subdomain_spec: OF phandle args to use for subdomain look-up
  *
  * Looks-up a parent PM domain and subdomain based upon phandle args
  * provided and adds the subdomain to the parent PM domain. Returns a
  * negative error code on failure.
  */
 int of_genpd_add_subdomain(struct of_phandle_args *parent_spec,
                struct of_phandle_args *subdomain_spec)
 {
     struct generic_pm_domain *parent, *subdomain;
     int ret;
 
     mutex_lock(&gpd_list_lock);
 
     parent = genpd_get_from_provider(parent_spec);
     if (IS_ERR(parent)) {
         ret = PTR_ERR(parent);
         goto out;
     }
 
     subdomain = genpd_get_from_provider(subdomain_spec);
     if (IS_ERR(subdomain)) {
         ret = PTR_ERR(subdomain);
         goto out;
     }
 
     ret = genpd_add_subdomain(parent, subdomain);
 
 out:
     mutex_unlock(&gpd_list_lock);
 
     return ret == -ENOENT ? -EPROBE_DEFER : ret;
 }
 EXPORT_SYMBOL_GPL(of_genpd_add_subdomain);
 
 /**
  * of_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
  * @parent_spec: OF phandle args to use for parent PM domain look-up
  * @subdomain_spec: OF phandle args to use for subdomain look-up
  *
  * Looks-up a parent PM domain and subdomain based upon phandle args
  * provided and removes the subdomain from the parent PM domain. Returns a
  * negative error code on failure.
  */
 int of_genpd_remove_subdomain(struct of_phandle_args *parent_spec,
                   struct of_phandle_args *subdomain_spec)
 {
     struct generic_pm_domain *parent, *subdomain;
     int ret;
 
     mutex_lock(&gpd_list_lock);
 
     parent = genpd_get_from_provider(parent_spec);
     if (IS_ERR(parent)) {
         ret = PTR_ERR(parent);
         goto out;
     }
 
     subdomain = genpd_get_from_provider(subdomain_spec);
     if (IS_ERR(subdomain)) {
         ret = PTR_ERR(subdomain);
         goto out;
     }
 
     ret = pm_genpd_remove_subdomain(parent, subdomain);
 
 out:
     mutex_unlock(&gpd_list_lock);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(of_genpd_remove_subdomain);
 
 /**
  * of_genpd_remove_last - Remove the last PM domain registered for a provider
  * @np: Pointer to device node associated with provider
  *
  * Find the last PM domain that was added by a particular provider and
  * remove this PM domain from the list of PM domains. The provider is
  * identified by the 'provider' device structure that is passed. The PM
  * domain will only be removed, if the provider associated with domain
  * has been removed.
  *
  * Returns a valid pointer to struct generic_pm_domain on success or
  * ERR_PTR() on failure.
  */
 struct generic_pm_domain *of_genpd_remove_last(struct device_node *np)
 {
     struct generic_pm_domain *gpd, *tmp, *genpd = ERR_PTR(-ENOENT);
     int ret;
 
     if (IS_ERR_OR_NULL(np))
         return ERR_PTR(-EINVAL);
 
     mutex_lock(&gpd_list_lock);
     list_for_each_entry_safe(gpd, tmp, &gpd_list, gpd_list_node) {
         if (gpd->provider == &np->fwnode) {
             ret = genpd_remove(gpd);
             genpd = ret ? ERR_PTR(ret) : gpd;
             break;
         }
     }
     mutex_unlock(&gpd_list_lock);
 
     return genpd;
 }
 EXPORT_SYMBOL_GPL(of_genpd_remove_last);
 
 static void genpd_release_dev(struct device *dev)
 {
     of_node_put(dev->of_node);
     kfree(dev);
 }
 
 static struct bus_type genpd_bus_type = {
     .name       = "genpd",
 };
 
 /**
  * genpd_dev_pm_detach - Detach a device from its PM domain.
  * @dev: Device to detach.
  * @power_off: Currently not used
  *
  * Try to locate a corresponding generic PM domain, which the device was
  * attached to previously. If such is found, the device is detached from it.
  */
 static void genpd_dev_pm_detach(struct device *dev, bool power_off)
 {
     struct generic_pm_domain *pd;
     unsigned int i;
     int ret = 0;
 
     pd = dev_to_genpd(dev);
     if (IS_ERR(pd))
         return;
 
     dev_dbg(dev, "removing from PM domain %s\n", pd->name);
 
     /* Drop the default performance state */
     if (dev_gpd_data(dev)->default_pstate) {
         dev_pm_genpd_set_performance_state(dev, 0);
         dev_gpd_data(dev)->default_pstate = 0;
     }
 
     for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
         ret = genpd_remove_device(pd, dev);
         if (ret != -EAGAIN)
             break;
 
         mdelay(i);
         cond_resched();
     }
 
     if (ret < 0) {
         dev_err(dev, "failed to remove from PM domain %s: %d",
             pd->name, ret);
         return;
     }
 
     /* Check if PM domain can be powered off after removing this device. */
     genpd_queue_power_off_work(pd);
 
     /* Unregister the device if it was created by genpd. */
     if (dev->bus == &genpd_bus_type)
         device_unregister(dev);
 }
 
 static void genpd_dev_pm_sync(struct device *dev)
 {
     struct generic_pm_domain *pd;
 
     pd = dev_to_genpd(dev);
     if (IS_ERR(pd))
         return;
 
     genpd_queue_power_off_work(pd);
 }
 
 static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
                  unsigned int index, bool power_on)
 {
     struct of_phandle_args pd_args;
     struct generic_pm_domain *pd;
     int pstate;
     int ret;
 
     ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
                 "#power-domain-cells", index, &pd_args);
     if (ret < 0)
         return ret;
 
     mutex_lock(&gpd_list_lock);
     pd = genpd_get_from_provider(&pd_args);
     of_node_put(pd_args.np);
     if (IS_ERR(pd)) {
         mutex_unlock(&gpd_list_lock);
         dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
             __func__, PTR_ERR(pd));
         return driver_deferred_probe_check_state(base_dev);
     }
 
     dev_dbg(dev, "adding to PM domain %s\n", pd->name);
 
     ret = genpd_add_device(pd, dev, base_dev);
     mutex_unlock(&gpd_list_lock);
 
     if (ret < 0)
         return dev_err_probe(dev, ret, "failed to add to PM domain %s\n", pd->name);
 
     dev->pm_domain->detach = genpd_dev_pm_detach;
     dev->pm_domain->sync = genpd_dev_pm_sync;
 
     if (power_on) {
         genpd_lock(pd);
         ret = genpd_power_on(pd, 0);
         genpd_unlock(pd);
     }
 
     if (ret) {
         genpd_remove_device(pd, dev);
         return -EPROBE_DEFER;
     }
 
     /* Set the default performance state */
     pstate = of_get_required_opp_performance_state(dev->of_node, index);
     if (pstate < 0 && pstate != -ENODEV && pstate != -EOPNOTSUPP) {
         ret = pstate;
         goto err;
     } else if (pstate > 0) {
         ret = dev_pm_genpd_set_performance_state(dev, pstate);
         if (ret)
             goto err;
         dev_gpd_data(dev)->default_pstate = pstate;
     }
     return 1;
 
 err:
     dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",
         pd->name, ret);
     genpd_remove_device(pd, dev);
     return ret;
 }
 
 /**
  * genpd_dev_pm_attach - Attach a device to its PM domain using DT.
  * @dev: Device to attach.
  *
  * Parse device's OF node to find a PM domain specifier. If such is found,
  * attaches the device to retrieved pm_domain ops.
  *
  * Returns 1 on successfully attached PM domain, 0 when the device don't need a
  * PM domain or when multiple power-domains exists for it, else a negative error
  * code. Note that if a power-domain exists for the device, but it cannot be
  * found or turned on, then return -EPROBE_DEFER to ensure that the device is
  * not probed and to re-try again later.
  */
 int genpd_dev_pm_attach(struct device *dev)
 {
     if (!dev->of_node)
         return 0;
 
     /*
      * Devices with multiple PM domains must be attached separately, as we
      * can only attach one PM domain per device.
      */
     if (of_count_phandle_with_args(dev->of_node, "power-domains",
                        "#power-domain-cells") != 1)
         return 0;
 
     return __genpd_dev_pm_attach(dev, dev, 0, true);
 }
 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
 
 /**
  * genpd_dev_pm_attach_by_id - Associate a device with one of its PM domains.
  * @dev: The device used to lookup the PM domain.
  * @index: The index of the PM domain.
  *
  * Parse device's OF node to find a PM domain specifier at the provided @index.
  * If such is found, creates a virtual device and attaches it to the retrieved
  * pm_domain ops. To deal with detaching of the virtual device, the ->detach()
  * callback in the struct dev_pm_domain are assigned to genpd_dev_pm_detach().
  *
  * Returns the created virtual device if successfully attached PM domain, NULL
  * when the device don't need a PM domain, else an ERR_PTR() in case of
  * failures. If a power-domain exists for the device, but cannot be found or
  * turned on, then ERR_PTR(-EPROBE_DEFER) is returned to ensure that the device
  * is not probed and to re-try again later.
  */
 struct device *genpd_dev_pm_attach_by_id(struct device *dev,
                      unsigned int index)
 {
     struct device *virt_dev;
     int num_domains;
     int ret;
 
     if (!dev->of_node)
         return NULL;
 
     /* Verify that the index is within a valid range. */
     num_domains = of_count_phandle_with_args(dev->of_node, "power-domains",
                          "#power-domain-cells");
     if (index >= num_domains)
         return NULL;
 
     /* Allocate and register device on the genpd bus. */
     virt_dev = kzalloc(sizeof(*virt_dev), GFP_KERNEL);
     if (!virt_dev)
         return ERR_PTR(-ENOMEM);
 
     dev_set_name(virt_dev, "genpd:%u:%s", index, dev_name(dev));
     virt_dev->bus = &genpd_bus_type;
     virt_dev->release = genpd_release_dev;
     virt_dev->of_node = of_node_get(dev->of_node);
 
     ret = device_register(virt_dev);
     if (ret) {
         put_device(virt_dev);
         return ERR_PTR(ret);
     }
 
     /* Try to attach the device to the PM domain at the specified index. */
     ret = __genpd_dev_pm_attach(virt_dev, dev, index, false);
     if (ret < 1) {
         device_unregister(virt_dev);
         return ret ? ERR_PTR(ret) : NULL;
     }
 
     pm_runtime_enable(virt_dev);
     genpd_queue_power_off_work(dev_to_genpd(virt_dev));
 
     return virt_dev;
 }
 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach_by_id);
 
 /**
  * genpd_dev_pm_attach_by_name - Associate a device with one of its PM domains.
  * @dev: The device used to lookup the PM domain.
  * @name: The name of the PM domain.
  *
  * Parse device's OF node to find a PM domain specifier using the
  * power-domain-names DT property. For further description see
  * genpd_dev_pm_attach_by_id().
  */
 struct device *genpd_dev_pm_attach_by_name(struct device *dev, const char *name)
 {
     int index;
 
     if (!dev->of_node)
         return NULL;
 
     index = of_property_match_string(dev->of_node, "power-domain-names",
                      name);
     if (index < 0)
         return NULL;
 
     return genpd_dev_pm_attach_by_id(dev, index);
 }
 
 static const struct of_device_id idle_state_match[] = {
     { .compatible = "domain-idle-state", },
     { }
 };
 
 static int genpd_parse_state(struct genpd_power_state *genpd_state,
                     struct device_node *state_node)
 {
     int err;
     u32 residency;
     u32 entry_latency, exit_latency;
 
     err = of_property_read_u32(state_node, "entry-latency-us",
                         &entry_latency);
     if (err) {
         pr_debug(" * %pOF missing entry-latency-us property\n",
              state_node);
         return -EINVAL;
     }
 
     err = of_property_read_u32(state_node, "exit-latency-us",
                         &exit_latency);
     if (err) {
         pr_debug(" * %pOF missing exit-latency-us property\n",
              state_node);
         return -EINVAL;
     }
 
     err = of_property_read_u32(state_node, "min-residency-us", &residency);
     if (!err)
         genpd_state->residency_ns = 1000 * residency;
 
     genpd_state->power_on_latency_ns = 1000 * exit_latency;
     genpd_state->power_off_latency_ns = 1000 * entry_latency;
     genpd_state->fwnode = &state_node->fwnode;
 
     return 0;
 }
 
 static int genpd_iterate_idle_states(struct device_node *dn,
                      struct genpd_power_state *states)
 {
     int ret;
     struct of_phandle_iterator it;
     struct device_node *np;
     int i = 0;
 
     ret = of_count_phandle_with_args(dn, "domain-idle-states", NULL);
     if (ret <= 0)
         return ret == -ENOENT ? 0 : ret;
 
     /* Loop over the phandles until all the requested entry is found */
     of_for_each_phandle(&it, ret, dn, "domain-idle-states", NULL, 0) {
         np = it.node;
         if (!of_match_node(idle_state_match, np))
             continue;
         if (states) {
             ret = genpd_parse_state(&states[i], np);
             if (ret) {
                 pr_err("Parsing idle state node %pOF failed with err %d\n",
                        np, ret);
                 of_node_put(np);
                 return ret;
             }
         }
         i++;
     }
 
     return i;
 }
 
 /**
  * of_genpd_parse_idle_states: Return array of idle states for the genpd.
  *
  * @dn: The genpd device node
  * @states: The pointer to which the state array will be saved.
  * @n: The count of elements in the array returned from this function.
  *
  * Returns the device states parsed from the OF node. The memory for the states
  * is allocated by this function and is the responsibility of the caller to
  * free the memory after use. If any or zero compatible domain idle states is
  * found it returns 0 and in case of errors, a negative error code is returned.
  */
 int of_genpd_parse_idle_states(struct device_node *dn,
             struct genpd_power_state **states, int *n)
 {
     struct genpd_power_state *st;
     int ret;
 
     ret = genpd_iterate_idle_states(dn, NULL);
     if (ret < 0)
         return ret;
 
     if (!ret) {
         *states = NULL;
         *n = 0;
         return 0;
     }
 
     st = kcalloc(ret, sizeof(*st), GFP_KERNEL);
     if (!st)
         return -ENOMEM;
 
     ret = genpd_iterate_idle_states(dn, st);
     if (ret <= 0) {
         kfree(st);
         return ret < 0 ? ret : -EINVAL;
     }
 
     *states = st;
     *n = ret;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(of_genpd_parse_idle_states);
 
 /**
  * pm_genpd_opp_to_performance_state - Gets performance state of the genpd from its OPP node.
  *
  * @genpd_dev: Genpd's device for which the performance-state needs to be found.
  * @opp: struct dev_pm_opp of the OPP for which we need to find performance
  *  state.
  *
  * Returns performance state encoded in the OPP of the genpd. This calls
  * platform specific genpd->opp_to_performance_state() callback to translate
  * power domain OPP to performance state.
  *
  * Returns performance state on success and 0 on failure.
  */
 unsigned int pm_genpd_opp_to_performance_state(struct device *genpd_dev,
                            struct dev_pm_opp *opp)
 {
     struct generic_pm_domain *genpd = NULL;
     int state;
 
     genpd = container_of(genpd_dev, struct generic_pm_domain, dev);
 
     if (unlikely(!genpd->opp_to_performance_state))
         return 0;
 
     genpd_lock(genpd);
     state = genpd->opp_to_performance_state(genpd, opp);
     genpd_unlock(genpd);
 
     return state;
 }
 EXPORT_SYMBOL_GPL(pm_genpd_opp_to_performance_state);
 
 static int __init genpd_bus_init(void)
 {
     return bus_register(&genpd_bus_type);
 }
 core_initcall(genpd_bus_init);
 
 #endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
 
 
 /***        debugfs support        ***/
 
 #ifdef CONFIG_DEBUG_FS
 /*
  * TODO: This function is a slightly modified version of rtpm_status_show
  * from sysfs.c, so generalize it.
  */
 static void rtpm_status_str(struct seq_file *s, struct device *dev)
 {
     static const char * const status_lookup[] = {
         [RPM_ACTIVE] = "active",
         [RPM_RESUMING] = "resuming",
         [RPM_SUSPENDED] = "suspended",
         [RPM_SUSPENDING] = "suspending"
     };
     const char *p = "";
 
     if (dev->power.runtime_error)
         p = "error";
     else if (dev->power.disable_depth)
         p = "unsupported";
     else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup))
         p = status_lookup[dev->power.runtime_status];
     else
         WARN_ON(1);
 
     seq_printf(s, "%-25s  ", p);
 }
 
 static void perf_status_str(struct seq_file *s, struct device *dev)
 {
     struct generic_pm_domain_data *gpd_data;
 
     gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
     seq_put_decimal_ull(s, "", gpd_data->performance_state);
 }
 
 static int genpd_summary_one(struct seq_file *s,
             struct generic_pm_domain *genpd)
 {
     static const char * const status_lookup[] = {
         [GENPD_STATE_ON] = "on",
         [GENPD_STATE_OFF] = "off"
     };
     struct pm_domain_data *pm_data;
     const char *kobj_path;
     struct gpd_link *link;
     char state[16];
     int ret;
 
     ret = genpd_lock_interruptible(genpd);
     if (ret)
         return -ERESTARTSYS;
 
     if (WARN_ON(genpd->status >= ARRAY_SIZE(status_lookup)))
         goto exit;
     if (!genpd_status_on(genpd))
         snprintf(state, sizeof(state), "%s-%u",
              status_lookup[genpd->status], genpd->state_idx);
     else
         snprintf(state, sizeof(state), "%s",
              status_lookup[genpd->status]);
     seq_printf(s, "%-30s  %-50s %u", genpd->name, state, genpd->performance_state);
 
     /*
      * Modifications on the list require holding locks on both
      * parent and child, so we are safe.
      * Also genpd->name is immutable.
      */
     list_for_each_entry(link, &genpd->parent_links, parent_node) {
         if (list_is_first(&link->parent_node, &genpd->parent_links))
             seq_printf(s, "\n%48s", " ");
         seq_printf(s, "%s", link->child->name);
         if (!list_is_last(&link->parent_node, &genpd->parent_links))
             seq_puts(s, ", ");
     }
 
     list_for_each_entry(pm_data, &genpd->dev_list, list_node) {
         kobj_path = kobject_get_path(&pm_data->dev->kobj,
                 genpd_is_irq_safe(genpd) ?
                 GFP_ATOMIC : GFP_KERNEL);
         if (kobj_path == NULL)
             continue;
 
         seq_printf(s, "\n    %-50s  ", kobj_path);
         rtpm_status_str(s, pm_data->dev);
         perf_status_str(s, pm_data->dev);
         kfree(kobj_path);
     }
 
     seq_puts(s, "\n");
 exit:
     genpd_unlock(genpd);
 
     return 0;
 }
 
 static int summary_show(struct seq_file *s, void *data)
 {
     struct generic_pm_domain *genpd;
     int ret = 0;
 
     seq_puts(s, "domain                          status          children                           performance\n");
     seq_puts(s, "    /device                                             runtime status\n");
     seq_puts(s, "----------------------------------------------------------------------------------------------\n");
 
     ret = mutex_lock_interruptible(&gpd_list_lock);
     if (ret)
         return -ERESTARTSYS;
 
     list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
         ret = genpd_summary_one(s, genpd);
         if (ret)
             break;
     }
     mutex_unlock(&gpd_list_lock);
 
     return ret;
 }
 
 static int status_show(struct seq_file *s, void *data)
 {
     static const char * const status_lookup[] = {
         [GENPD_STATE_ON] = "on",
         [GENPD_STATE_OFF] = "off"
     };
 
     struct generic_pm_domain *genpd = s->private;
     int ret = 0;
 
     ret = genpd_lock_interruptible(genpd);
     if (ret)
         return -ERESTARTSYS;
 
     if (WARN_ON_ONCE(genpd->status >= ARRAY_SIZE(status_lookup)))
         goto exit;
 
     if (genpd->status == GENPD_STATE_OFF)
         seq_printf(s, "%s-%u\n", status_lookup[genpd->status],
             genpd->state_idx);
     else
         seq_printf(s, "%s\n", status_lookup[genpd->status]);
 exit:
     genpd_unlock(genpd);
     return ret;
 }
 
 static int sub_domains_show(struct seq_file *s, void *data)
 {
     struct generic_pm_domain *genpd = s->private;
     struct gpd_link *link;
     int ret = 0;
 
     ret = genpd_lock_interruptible(genpd);
     if (ret)
         return -ERESTARTSYS;
 
     list_for_each_entry(link, &genpd->parent_links, parent_node)
         seq_printf(s, "%s\n", link->child->name);
 
     genpd_unlock(genpd);
     return ret;
 }
 
 static int idle_states_show(struct seq_file *s, void *data)
 {
     struct generic_pm_domain *genpd = s->private;
     u64 now, delta, idle_time = 0;
     unsigned int i;
     int ret = 0;
 
     ret = genpd_lock_interruptible(genpd);
     if (ret)
         return -ERESTARTSYS;
 
     seq_puts(s, "State          Time Spent(ms) Usage          Rejected\n");
 
     for (i = 0; i < genpd->state_count; i++) {
         idle_time += genpd->states[i].idle_time;
 
         if (genpd->status == GENPD_STATE_OFF && genpd->state_idx == i) {
             now = ktime_get_mono_fast_ns();
             if (now > genpd->accounting_time) {
                 delta = now - genpd->accounting_time;
                 idle_time += delta;
             }
         }
 
         do_div(idle_time, NSEC_PER_MSEC);
         seq_printf(s, "S%-13i %-14llu %-14llu %llu\n", i, idle_time,
                genpd->states[i].usage, genpd->states[i].rejected);
     }
 
     genpd_unlock(genpd);
     return ret;
 }
 
 static int active_time_show(struct seq_file *s, void *data)
 {
     struct generic_pm_domain *genpd = s->private;
     u64 now, on_time, delta = 0;
     int ret = 0;
 
     ret = genpd_lock_interruptible(genpd);
     if (ret)
         return -ERESTARTSYS;
 
     if (genpd->status == GENPD_STATE_ON) {
         now = ktime_get_mono_fast_ns();
         if (now > genpd->accounting_time)
             delta = now - genpd->accounting_time;
     }
 
     on_time = genpd->on_time + delta;
     do_div(on_time, NSEC_PER_MSEC);
     seq_printf(s, "%llu ms\n", on_time);
 
     genpd_unlock(genpd);
     return ret;
 }
 
 static int total_idle_time_show(struct seq_file *s, void *data)
 {
     struct generic_pm_domain *genpd = s->private;
     u64 now, delta, total = 0;
     unsigned int i;
     int ret = 0;
 
     ret = genpd_lock_interruptible(genpd);
     if (ret)
         return -ERESTARTSYS;
 
     for (i = 0; i < genpd->state_count; i++) {
         total += genpd->states[i].idle_time;
 
         if (genpd->status == GENPD_STATE_OFF && genpd->state_idx == i) {
             now = ktime_get_mono_fast_ns();
             if (now > genpd->accounting_time) {
                 delta = now - genpd->accounting_time;
                 total += delta;
             }
         }
     }
 
     do_div(total, NSEC_PER_MSEC);
     seq_printf(s, "%llu ms\n", total);
 
     genpd_unlock(genpd);
     return ret;
 }
 
 
 static int devices_show(struct seq_file *s, void *data)
 {
     struct generic_pm_domain *genpd = s->private;
     struct pm_domain_data *pm_data;
     const char *kobj_path;
     int ret = 0;
 
     ret = genpd_lock_interruptible(genpd);
     if (ret)
         return -ERESTARTSYS;
 
     list_for_each_entry(pm_data, &genpd->dev_list, list_node) {
         kobj_path = kobject_get_path(&pm_data->dev->kobj,
                 genpd_is_irq_safe(genpd) ?
                 GFP_ATOMIC : GFP_KERNEL);
         if (kobj_path == NULL)
             continue;
 
         seq_printf(s, "%s\n", kobj_path);
         kfree(kobj_path);
     }
 
     genpd_unlock(genpd);
     return ret;
 }
 
 static int perf_state_show(struct seq_file *s, void *data)
 {
     struct generic_pm_domain *genpd = s->private;
 
     if (genpd_lock_interruptible(genpd))
         return -ERESTARTSYS;
 
     seq_printf(s, "%u\n", genpd->performance_state);
 
     genpd_unlock(genpd);
     return 0;
 }
 
 DEFINE_SHOW_ATTRIBUTE(summary);
 DEFINE_SHOW_ATTRIBUTE(status);
 DEFINE_SHOW_ATTRIBUTE(sub_domains);
 DEFINE_SHOW_ATTRIBUTE(idle_states);
 DEFINE_SHOW_ATTRIBUTE(active_time);
 DEFINE_SHOW_ATTRIBUTE(total_idle_time);
 DEFINE_SHOW_ATTRIBUTE(devices);
 DEFINE_SHOW_ATTRIBUTE(perf_state);
 
 static void genpd_debug_add(struct generic_pm_domain *genpd)
 {
     struct dentry *d;
 
     if (!genpd_debugfs_dir)
         return;
 
     d = debugfs_create_dir(genpd->name, genpd_debugfs_dir);
 
     debugfs_create_file("current_state", 0444,
                 d, genpd, &status_fops);
     debugfs_create_file("sub_domains", 0444,
                 d, genpd, &sub_domains_fops);
     debugfs_create_file("idle_states", 0444,
                 d, genpd, &idle_states_fops);
     debugfs_create_file("active_time", 0444,
                 d, genpd, &active_time_fops);
     debugfs_create_file("total_idle_time", 0444,
                 d, genpd, &total_idle_time_fops);
     debugfs_create_file("devices", 0444,
                 d, genpd, &devices_fops);
     if (genpd->set_performance_state)
         debugfs_create_file("perf_state", 0444,
                     d, genpd, &perf_state_fops);
 }
 
 static int __init genpd_debug_init(void)
 {
     struct generic_pm_domain *genpd;
 
     genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL);
 
     debugfs_create_file("pm_genpd_summary", S_IRUGO, genpd_debugfs_dir,
                 NULL, &summary_fops);
 
     list_for_each_entry(genpd, &gpd_list, gpd_list_node)
         genpd_debug_add(genpd);
 
     return 0;
 }
 late_initcall(genpd_debug_init);
 
 static void __exit genpd_debug_exit(void)
 {
     debugfs_remove_recursive(genpd_debugfs_dir);
 }
 __exitcall(genpd_debug_exit);
 #endif /* CONFIG_DEBUG_FS */