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Commit 1d5fcfec authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

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: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent cbc9ef02

drivers/base/power/domain.c

+57 −26
Original line number Diff line number Diff line
@@ -297,7 +297,7 @@ static int genpd_dev_pm_qos_notifier(struct notifier_block *nb, 


		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 @@ static void pm_genpd_complete(struct device *dev) 


#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 @@ static void pm_genpd_complete(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;

	struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL;

	struct pm_domain_data *pdd;

	int ret = 0;
@@ -1284,14 +1305,10 @@ 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 = 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 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, 
			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;

	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->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->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 @@ 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__);
@@ -1399,22 +1424,28 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd, 
	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);

	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:

include/linux/pm_domain.h

+1 −0
Original line number Diff line number Diff line
@@ -112,6 +112,7 @@ struct generic_pm_domain_data { 
	struct gpd_timing_data td;

	struct notifier_block nb;

	struct mutex lock;

	unsigned int refcount;

	bool need_restore;

	bool always_on;

};