Commit b24e1965 authored by Ulf Hansson's avatar Ulf Hansson Committed by Rafael J. Wysocki
Browse files

PM / Domains: Search for the CPU device outside the genpd lock 



While attaching/detaching a device to a PM domain (genpd) with
GENPD_FLAG_CPU_DOMAIN set, genpd iterates the cpu_possible_mask to
check whether or not the device corresponds to a CPU. This iteration
is done while holding the genpd's lock, which is unnecessary.

Avoid the locking by restructuring the corresponding code a bit.

Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent a174920d

drivers/base/power/domain.c

+27 −25
Original line number Diff line number Diff line
@@ -1450,7 +1450,7 @@ static void genpd_free_dev_data(struct device *dev, 
	dev_pm_put_subsys_data(dev);

}



static void __genpd_update_cpumask(struct generic_pm_domain *genpd,

static void genpd_update_cpumask(struct generic_pm_domain *genpd,

				 int cpu, bool set, unsigned int depth)

{

	struct gpd_link *link;
@@ -1462,7 +1462,7 @@ static void __genpd_update_cpumask(struct generic_pm_domain *genpd, 
		struct generic_pm_domain *master = link->master;



		genpd_lock_nested(master, depth + 1);

		__genpd_update_cpumask(master, cpu, set, depth + 1);

		genpd_update_cpumask(master, cpu, set, depth + 1);

		genpd_unlock(master);

	}
@@ -1472,38 +1472,37 @@ static void __genpd_update_cpumask(struct generic_pm_domain *genpd, 
		cpumask_clear_cpu(cpu, genpd->cpus);

}



static void genpd_update_cpumask(struct generic_pm_domain *genpd,

				 struct device *dev, bool set)

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;

		return -1;



	for_each_possible_cpu(cpu) {

		if (get_cpu_device(cpu) == dev) {

			__genpd_update_cpumask(genpd, cpu, set, 0);

			return;

		}

	}

}



static void genpd_set_cpumask(struct generic_pm_domain *genpd,

			      struct device *dev)

{

	genpd_update_cpumask(genpd, dev, true);

		if (get_cpu_device(cpu) == dev)

			return cpu;

	}



static void genpd_clear_cpumask(struct generic_pm_domain *genpd,

				struct device *dev)

{

	genpd_update_cpumask(genpd, dev, false);

	return -1;

}



static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)

{

	struct generic_pm_domain_data *gpd_data;

	int ret;

	int ret, cpu;



	dev_dbg(dev, "%s()\n", __func__);
@@ -1514,13 +1513,15 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev) 
	if (IS_ERR(gpd_data))

		return PTR_ERR(gpd_data);



	cpu = genpd_get_cpu(genpd, dev);



	ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0;

	if (ret)

		goto out;



	genpd_lock(genpd);



	genpd_set_cpumask(genpd, dev);

	genpd_set_cpumask(genpd, cpu);

	dev_pm_domain_set(dev, &genpd->domain);



	genpd->device_count++;
@@ -1560,13 +1561,14 @@ static int genpd_remove_device(struct generic_pm_domain *genpd, 
{

	struct generic_pm_domain_data *gpd_data;

	struct pm_domain_data *pdd;

	int ret = 0;

	int cpu, 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);

	cpu = genpd_get_cpu(genpd, dev);



	genpd_lock(genpd);
@@ -1578,7 +1580,7 @@ static int genpd_remove_device(struct generic_pm_domain *genpd, 
	genpd->device_count--;

	genpd->max_off_time_changed = true;



	genpd_clear_cpumask(genpd, dev);

	genpd_clear_cpumask(genpd, cpu);

	dev_pm_domain_set(dev, NULL);



	list_del_init(&pdd->list_node);

CRA Git | Maintained and supported by SUSTech CRA and CCSE