From b24e196586fecafed1c3cff9b2f87c1a64138ade Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Thu, 25 Apr 2019 11:04:12 +0200 Subject: [PATCH] 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 Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/base/power/domain.c | 52 +++++++++++++++++++------------------ 1 file changed, 27 insertions(+), 25 deletions(-) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 93298b7db408..da1c99178943 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -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);