From eb594b7325f61835555140922a4cb715264a325c Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Wed, 27 Mar 2019 15:35:46 +0100 Subject: [PATCH] PM / Domains: Add support for CPU devices to genpd To enable a CPU device to be attached to a PM domain managed by genpd, make a few changes to it for convenience. To be able to quickly find out what CPUs are attached to a genpd, which typically becomes useful from a genpd governor as subsequent changes are about to show, add a cpumask to struct generic_pm_domain to be updated when a CPU device gets attached to the genpd containing that cpumask. Also, propagate the cpumask changes upwards in the domain hierarchy to the master PM domains. This way, the cpumask for a genpd hierarchically reflects all CPUs attached to the topology below it. Finally, make this an opt-in feature, to avoid having to manage CPUs and the cpumask for a genpd that don't need it. To that end, add a new genpd configuration bit, GENPD_FLAG_CPU_DOMAIN. Co-developed-by: Lina Iyer Acked-by: Daniel Lezcano Signed-off-by: Ulf Hansson [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki --- drivers/base/power/domain.c | 65 ++++++++++++++++++++++++++++++++++++++++++++- include/linux/pm_domain.h | 13 +++++++++ 2 files changed, 77 insertions(+), 1 deletion(-) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index ff6f992..ecac03d 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "power.h" @@ -128,6 +129,7 @@ static const struct genpd_lock_ops genpd_spin_ops = { #define genpd_is_irq_safe(genpd) (genpd->flags & GENPD_FLAG_IRQ_SAFE) #define genpd_is_always_on(genpd) (genpd->flags & GENPD_FLAG_ALWAYS_ON) #define genpd_is_active_wakeup(genpd) (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP) +#define genpd_is_cpu_domain(genpd) (genpd->flags & GENPD_FLAG_CPU_DOMAIN) static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev, const struct generic_pm_domain *genpd) @@ -1454,6 +1456,56 @@ 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) +{ + struct gpd_link *link; + + if (!genpd_is_cpu_domain(genpd)) + return; + + list_for_each_entry(link, &genpd->slave_links, slave_node) { + struct generic_pm_domain *master = link->master; + + genpd_lock_nested(master, depth + 1); + __genpd_update_cpumask(master, cpu, set, depth + 1); + genpd_unlock(master); + } + + if (set) + cpumask_set_cpu(cpu, genpd->cpus); + else + cpumask_clear_cpu(cpu, genpd->cpus); +} + +static void genpd_update_cpumask(struct generic_pm_domain *genpd, + struct device *dev, bool set) +{ + int cpu; + + if (!genpd_is_cpu_domain(genpd)) + return; + + 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); +} + +static void genpd_clear_cpumask(struct generic_pm_domain *genpd, + struct device *dev) +{ + genpd_update_cpumask(genpd, dev, false); +} + static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, struct gpd_timing_data *td) { @@ -1475,6 +1527,7 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, genpd_lock(genpd); + genpd_set_cpumask(genpd, dev); dev_pm_domain_set(dev, &genpd->domain); genpd->device_count++; @@ -1532,6 +1585,7 @@ static int genpd_remove_device(struct generic_pm_domain *genpd, genpd->device_count--; genpd->max_off_time_changed = true; + genpd_clear_cpumask(genpd, dev); dev_pm_domain_set(dev, NULL); list_del_init(&pdd->list_node); @@ -1768,11 +1822,18 @@ int pm_genpd_init(struct generic_pm_domain *genpd, if (genpd_is_always_on(genpd) && !genpd_status_on(genpd)) return -EINVAL; + if (genpd_is_cpu_domain(genpd) && + !zalloc_cpumask_var(&genpd->cpus, GFP_KERNEL)) + return -ENOMEM; + /* Use only one "off" state if there were no states declared */ if (genpd->state_count == 0) { ret = genpd_set_default_power_state(genpd); - if (ret) + if (ret) { + if (genpd_is_cpu_domain(genpd)) + free_cpumask_var(genpd->cpus); return ret; + } } else if (!gov && genpd->state_count > 1) { pr_warn("%s: no governor for states\n", genpd->name); } @@ -1818,6 +1879,8 @@ static int genpd_remove(struct generic_pm_domain *genpd) list_del(&genpd->gpd_list_node); genpd_unlock(genpd); cancel_work_sync(&genpd->power_off_work); + if (genpd_is_cpu_domain(genpd)) + free_cpumask_var(genpd->cpus); if (genpd->free_states) genpd->free_states(genpd->states, genpd->state_count); diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 8e13992..a6e251fe 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -16,6 +16,7 @@ #include #include #include +#include /* * Flags to control the behaviour of a genpd. @@ -42,11 +43,22 @@ * GENPD_FLAG_ACTIVE_WAKEUP: Instructs genpd to keep the PM domain powered * on, in case any of its attached devices is used * in the wakeup path to serve system wakeups. + * + * GENPD_FLAG_CPU_DOMAIN: Instructs genpd that it should expect to get + * devices attached, which may belong to CPUs or + * possibly have subdomains with CPUs attached. + * This flag enables the genpd backend driver to + * deploy idle power management support for CPUs + * and groups of CPUs. Note that, the backend + * driver must then comply with the so called, + * last-man-standing algorithm, for the CPUs in the + * PM domain. */ #define GENPD_FLAG_PM_CLK (1U << 0) #define GENPD_FLAG_IRQ_SAFE (1U << 1) #define GENPD_FLAG_ALWAYS_ON (1U << 2) #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) +#define GENPD_FLAG_CPU_DOMAIN (1U << 4) enum gpd_status { GPD_STATE_ACTIVE = 0, /* PM domain is active */ @@ -94,6 +106,7 @@ struct generic_pm_domain { unsigned int suspended_count; /* System suspend device counter */ unsigned int prepared_count; /* Suspend counter of prepared devices */ unsigned int performance_state; /* Aggregated max performance state */ + cpumask_var_t cpus; /* A cpumask of the attached CPUs */ int (*power_off)(struct generic_pm_domain *domain); int (*power_on)(struct generic_pm_domain *domain); struct opp_table *opp_table; /* OPP table of the genpd */ -- 2.7.4