PM / Domains: Add device domain data reference counter
Add a mechanism for counting references to the
struct generic_pm_domain_data object pointed to by
dev->power.subsys_data->domain_data if the device in question
belongs to a generic PM domain.
This change is necessary for a subsequent patch making it possible to
allocate that object from within pm_genpd_add_callbacks(), so that
drivers can attach their PM domain device callbacks to devices before
those devices are added to PM domains.
This patch has been tested on the SH7372 Mackerel board.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 4b5f090..45eb3b1 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -297,7 +297,7 @@
pdd = dev->power.subsys_data ?
dev->power.subsys_data->domain_data : NULL;
- if (pdd) {
+ if (pdd && pdd->dev) {
to_gpd_data(pdd)->td.constraint_changed = true;
genpd = dev_to_genpd(dev);
} else {
@@ -1266,6 +1266,27 @@
#endif /* CONFIG_PM_SLEEP */
+static struct generic_pm_domain_data *__pm_genpd_alloc_dev_data(struct device *dev)
+{
+ struct generic_pm_domain_data *gpd_data;
+
+ gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
+ if (!gpd_data)
+ return NULL;
+
+ mutex_init(&gpd_data->lock);
+ gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
+ dev_pm_qos_add_notifier(dev, &gpd_data->nb);
+ return gpd_data;
+}
+
+static void __pm_genpd_free_dev_data(struct device *dev,
+ struct generic_pm_domain_data *gpd_data)
+{
+ dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
+ kfree(gpd_data);
+}
+
/**
* __pm_genpd_add_device - Add a device to an I/O PM domain.
* @genpd: PM domain to add the device to.
@@ -1275,7 +1296,7 @@
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;
+ struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL;
struct pm_domain_data *pdd;
int ret = 0;
@@ -1284,14 +1305,10 @@
if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
return -EINVAL;
- gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
- if (!gpd_data)
+ gpd_data_new = __pm_genpd_alloc_dev_data(dev);
+ if (!gpd_data_new)
return -ENOMEM;
- mutex_init(&gpd_data->lock);
- gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
- dev_pm_qos_add_notifier(dev, &gpd_data->nb);
-
genpd_acquire_lock(genpd);
if (genpd->prepared_count > 0) {
@@ -1305,35 +1322,42 @@
goto out;
}
+ ret = dev_pm_get_subsys_data(dev);
+ if (ret)
+ goto out;
+
genpd->device_count++;
genpd->max_off_time_changed = true;
- dev_pm_get_subsys_data(dev);
-
- mutex_lock(&gpd_data->lock);
spin_lock_irq(&dev->power.lock);
+
dev->pm_domain = &genpd->domain;
- dev->power.subsys_data->domain_data = &gpd_data->base;
- gpd_data->base.dev = dev;
- list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
- gpd_data->need_restore = genpd->status == GPD_STATE_POWER_OFF;
+ 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);
+
+ 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 = genpd->status == GPD_STATE_POWER_OFF;
gpd_data->td.constraint_changed = true;
gpd_data->td.effective_constraint_ns = -1;
- spin_unlock_irq(&dev->power.lock);
mutex_unlock(&gpd_data->lock);
- genpd_release_lock(genpd);
-
- return 0;
-
out:
genpd_release_lock(genpd);
- dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
- kfree(gpd_data);
+ if (gpd_data != gpd_data_new)
+ __pm_genpd_free_dev_data(dev, gpd_data_new);
+
return ret;
}
@@ -1379,6 +1403,7 @@
{
struct generic_pm_domain_data *gpd_data;
struct pm_domain_data *pdd;
+ bool remove = false;
int ret = 0;
dev_dbg(dev, "%s()\n", __func__);
@@ -1399,22 +1424,28 @@
genpd->max_off_time_changed = true;
spin_lock_irq(&dev->power.lock);
+
dev->pm_domain = NULL;
pdd = dev->power.subsys_data->domain_data;
list_del_init(&pdd->list_node);
- dev->power.subsys_data->domain_data = NULL;
+ 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);
- gpd_data = to_gpd_data(pdd);
mutex_lock(&gpd_data->lock);
pdd->dev = NULL;
mutex_unlock(&gpd_data->lock);
genpd_release_lock(genpd);
- dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
- kfree(gpd_data);
dev_pm_put_subsys_data(dev);
+ if (remove)
+ __pm_genpd_free_dev_data(dev, gpd_data);
+
return 0;
out:
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 2febe31..a7d6172 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -112,6 +112,7 @@
struct gpd_timing_data td;
struct notifier_block nb;
struct mutex lock;
+ unsigned int refcount;
bool need_restore;
bool always_on;
};