Merge branch 'pm-domains'

* pm-domains:
  PM: Convert dev_pm_put_subsys_data() into a void function
  PM: Update function header for dev_pm_get_subsys_data()
  PM / Domains: Handle errors from genpd's ->attach_dev() callback
  PM / Domains: Re-order initialization of generic_pm_domain_data
  PM / Domains: Free pm_subsys_data in error path in __pm_genpd_add_device()
  PM / Domains: Eliminate the mutex for the generic_pm_domain_data
  PM / Domains: Don't check for an existing device when adding a new
  PM / Domains: Don't allow an existing generic_pm_domain_data
  PM / Domains: Remove reference counting for the generic_pm_domain_data
  PM / Domains: Rename __pm_genpd_alloc|free_dev_data()
  PM / Domains: Remove pm_genpd_dev_need_restore() API

2 files changed, 71 insertions, 104 deletions

diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
index b0f138806bbc..f32b802b98f4 100644
--- a/drivers/base/power/common.c
+++ b/drivers/base/power/common.c
@@ -19,8 +19,8 @@
  * @dev: Device to handle.
  *
  * If power.subsys_data is NULL, point it to a new object, otherwise increment
- * its reference counter.  Return 1 if a new object has been created, otherwise
- * return 0 or error code.
+ * its reference counter.  Return 0 if new object has been created or refcount
+ * increased, otherwise negative error code.
  */
 int dev_pm_get_subsys_data(struct device *dev)
 {
@@ -56,13 +56,11 @@ EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
  * @dev: Device to handle.
  *
  * If the reference counter of power.subsys_data is zero after dropping the
- * reference, power.subsys_data is removed.  Return 1 if that happens or 0
- * otherwise.
+ * reference, power.subsys_data is removed.
  */
-int dev_pm_put_subsys_data(struct device *dev)
+void dev_pm_put_subsys_data(struct device *dev)
 {
         struct pm_subsys_data *psd;
-        int ret = 1;
 
         spin_lock_irq(&dev->power.lock);
 
@@ -70,18 +68,14 @@ int dev_pm_put_subsys_data(struct device *dev)
         if (!psd)
                 goto out;
 
-        if (--psd->refcount == 0) {
+        if (--psd->refcount == 0)
                 dev->power.subsys_data = NULL;
-        } else {
+        else
                 psd = NULL;
-                ret = 0;
-        }
 
  out:
         spin_unlock_irq(&dev->power.lock);
         kfree(psd);
-
-        return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
 
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 0d8780c04a5e..ba4abbe4693c 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -344,14 +344,7 @@ static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
         struct device *dev;
 
         gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
-
-        mutex_lock(&gpd_data->lock);
         dev = gpd_data->base.dev;
-        if (!dev) {
-                mutex_unlock(&gpd_data->lock);
-                return NOTIFY_DONE;
-        }
-        mutex_unlock(&gpd_data->lock);
 
         for (;;) {
                 struct generic_pm_domain *genpd;
@@ -1384,25 +1377,66 @@ EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron);
 
 #endif /* CONFIG_PM_SLEEP */
 
-static struct generic_pm_domain_data *__pm_genpd_alloc_dev_data(struct device *dev)
+static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
+                                        struct generic_pm_domain *genpd,
+                                        struct gpd_timing_data *td)
 {
         struct generic_pm_domain_data *gpd_data;
+        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)
-                return NULL;
+        if (!gpd_data) {
+                ret = -ENOMEM;
+                goto err_put;
+        }
+
+        if (td)
+                gpd_data->td = *td;
 
-        mutex_init(&gpd_data->lock);
+        gpd_data->base.dev = dev;
+        gpd_data->need_restore = -1;
+        gpd_data->td.constraint_changed = true;
+        gpd_data->td.effective_constraint_ns = -1;
         gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
-        dev_pm_qos_add_notifier(dev, &gpd_data->nb);
+
+        spin_lock_irq(&dev->power.lock);
+
+        if (dev->power.subsys_data->domain_data) {
+                ret = -EINVAL;
+                goto err_free;
+        }
+
+        dev->power.subsys_data->domain_data = &gpd_data->base;
+        dev->pm_domain = &genpd->domain;
+
+        spin_unlock_irq(&dev->power.lock);
+
         return gpd_data;
+
+ err_free:
+        spin_unlock_irq(&dev->power.lock);
+        kfree(gpd_data);
+ err_put:
+        dev_pm_put_subsys_data(dev);
+        return ERR_PTR(ret);
 }
 
-static void __pm_genpd_free_dev_data(struct device *dev,
-                                     struct generic_pm_domain_data *gpd_data)
+static void genpd_free_dev_data(struct device *dev,
+                                struct generic_pm_domain_data *gpd_data)
 {
-        dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
+        spin_lock_irq(&dev->power.lock);
+
+        dev->pm_domain = NULL;
+        dev->power.subsys_data->domain_data = NULL;
+
+        spin_unlock_irq(&dev->power.lock);
+
         kfree(gpd_data);
+        dev_pm_put_subsys_data(dev);
 }
 
 /**
@@ -1414,8 +1448,7 @@ static void __pm_genpd_free_dev_data(struct device *dev,
 int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
                           struct gpd_timing_data *td)
 {
-        struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL;
-        struct pm_domain_data *pdd;
+        struct generic_pm_domain_data *gpd_data;
         int ret = 0;
 
         dev_dbg(dev, "%s()\n", __func__);
@@ -1423,9 +1456,9 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
                 return -EINVAL;
 
-        gpd_data_new = __pm_genpd_alloc_dev_data(dev);
-        if (!gpd_data_new)
-                return -ENOMEM;
+        gpd_data = genpd_alloc_dev_data(dev, genpd, td);
+        if (IS_ERR(gpd_data))
+                return PTR_ERR(gpd_data);
 
         genpd_acquire_lock(genpd);
 
@@ -1434,50 +1467,22 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
                 goto out;
         }
 
-        list_for_each_entry(pdd, &genpd->dev_list, list_node)
-                if (pdd->dev == dev) {
-                        ret = -EINVAL;
-                        goto out;
-                }
-
-        ret = dev_pm_get_subsys_data(dev);
+        ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0;
         if (ret)
                 goto out;
 
         genpd->device_count++;
         genpd->max_off_time_changed = true;
 
-        spin_lock_irq(&dev->power.lock);
-
-        dev->pm_domain = &genpd->domain;
-        if (dev->power.subsys_data->domain_data) {
-                gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
-        } else {
-                gpd_data = gpd_data_new;
-                dev->power.subsys_data->domain_data = &gpd_data->base;
-        }
-        gpd_data->refcount++;
-        if (td)
-                gpd_data->td = *td;
-
-        spin_unlock_irq(&dev->power.lock);
-
-        if (genpd->attach_dev)
-                genpd->attach_dev(genpd, dev);
-
-        mutex_lock(&gpd_data->lock);
-        gpd_data->base.dev = dev;
         list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
-        gpd_data->need_restore = -1;
-        gpd_data->td.constraint_changed = true;
-        gpd_data->td.effective_constraint_ns = -1;
-        mutex_unlock(&gpd_data->lock);
 
  out:
         genpd_release_lock(genpd);
 
-        if (gpd_data != gpd_data_new)
-                __pm_genpd_free_dev_data(dev, gpd_data_new);
+        if (ret)
+                genpd_free_dev_data(dev, gpd_data);
+        else
+                dev_pm_qos_add_notifier(dev, &gpd_data->nb);
 
         return ret;
 }
@@ -1504,7 +1509,6 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 {
         struct generic_pm_domain_data *gpd_data;
         struct pm_domain_data *pdd;
-        bool remove = false;
         int ret = 0;
 
         dev_dbg(dev, "%s()\n", __func__);
@@ -1514,6 +1518,11 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
             ||  pd_to_genpd(dev->pm_domain) != genpd)
                 return -EINVAL;
 
+        /* The above validation also means we have existing domain_data. */
+        pdd = dev->power.subsys_data->domain_data;
+        gpd_data = to_gpd_data(pdd);
+        dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
+
         genpd_acquire_lock(genpd);
 
         if (genpd->prepared_count > 0) {
@@ -1527,58 +1536,22 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
         if (genpd->detach_dev)
                 genpd->detach_dev(genpd, dev);
 
-        spin_lock_irq(&dev->power.lock);
-
-        dev->pm_domain = NULL;
-        pdd = dev->power.subsys_data->domain_data;
         list_del_init(&pdd->list_node);
-        gpd_data = to_gpd_data(pdd);
-        if (--gpd_data->refcount == 0) {
-                dev->power.subsys_data->domain_data = NULL;
-                remove = true;
-        }
-
-        spin_unlock_irq(&dev->power.lock);
-
-        mutex_lock(&gpd_data->lock);
-        pdd->dev = NULL;
-        mutex_unlock(&gpd_data->lock);
 
         genpd_release_lock(genpd);
 
-        dev_pm_put_subsys_data(dev);
-        if (remove)
-                __pm_genpd_free_dev_data(dev, gpd_data);
+        genpd_free_dev_data(dev, gpd_data);
 
         return 0;
 
  out:
         genpd_release_lock(genpd);
+        dev_pm_qos_add_notifier(dev, &gpd_data->nb);
 
         return ret;
 }
 
 /**
- * pm_genpd_dev_need_restore - Set/unset the device's "need restore" flag.
- * @dev: Device to set/unset the flag for.
- * @val: The new value of the device's "need restore" flag.
- */
-void pm_genpd_dev_need_restore(struct device *dev, bool val)
-{
-        struct pm_subsys_data *psd;
-        unsigned long flags;
-
-        spin_lock_irqsave(&dev->power.lock, flags);
-
-        psd = dev_to_psd(dev);
-        if (psd && psd->domain_data)
-                to_gpd_data(psd->domain_data)->need_restore = val ? 1 : 0;
-
-        spin_unlock_irqrestore(&dev->power.lock, flags);
-}
-EXPORT_SYMBOL_GPL(pm_genpd_dev_need_restore);
-
-/**
  * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
  * @genpd: Master PM domain to add the subdomain to.
  * @subdomain: Subdomain to be added.