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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: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Ulf Hansson 2019-04-25 11:04:12 +02:00 committed by Rafael J. Wysocki
parent a174920d69
commit b24e196586
1 changed files with 27 additions and 25 deletions
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52
drivers/base/power/domain.c
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@ -1450,8 +1450,8 @@ 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,
int cpu, bool set, unsigned int depth)
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;
}
if (get_cpu_device(cpu) == dev)
return cpu;
}
}
static void genpd_set_cpumask(struct generic_pm_domain *genpd,
struct device *dev)
{
genpd_update_cpumask(genpd, dev, true);
}
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);