From 49a27e279052cf71ba931a26b00194ff46510480 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Wed, 27 Mar 2019 15:35:45 +0100 Subject: PM / Domains: Add generic data pointer to struct genpd_power_state Add a data pointer to the genpd_power_state struct, to allow a genpd backend driver to store per-state specific data. To introduce the pointer, change the way genpd deals with freeing of the corresponding allocated data. More precisely, clarify the responsibility of whom that shall free the data, by adding a ->free_states() callback to the generic_pm_domain structure. The one allocating the data will be expected to set the callback, to allow genpd to invoke it from genpd_remove(). Co-developed-by: Lina Iyer Acked-by: Daniel Lezcano Signed-off-by: Ulf Hansson [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki --- drivers/base/power/domain.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'drivers/base/power') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 96a6dc9d305c..ff6f992f7a1d 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -1686,6 +1686,12 @@ out: } EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain); +static void genpd_free_default_power_state(struct genpd_power_state *states, + unsigned int state_count) +{ + kfree(states); +} + static int genpd_set_default_power_state(struct generic_pm_domain *genpd) { struct genpd_power_state *state; @@ -1696,7 +1702,7 @@ static int genpd_set_default_power_state(struct generic_pm_domain *genpd) genpd->states = state; genpd->state_count = 1; - genpd->free = state; + genpd->free_states = genpd_free_default_power_state; return 0; } @@ -1812,7 +1818,9 @@ 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); - kfree(genpd->free); + if (genpd->free_states) + genpd->free_states(genpd->states, genpd->state_count); + pr_debug("%s: removed %s\n", __func__, genpd->name); return 0; -- cgit v1.2.3 From eb594b7325f61835555140922a4cb715264a325c Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Wed, 27 Mar 2019 15:35:46 +0100 Subject: 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(-) (limited to 'drivers/base/power') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index ff6f992f7a1d..ecac03dcc9b2 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 8e1399231753..a6e251fe9deb 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 */ -- cgit v1.2.3 From e94999688e3aa3c0a8ad5a60352cdc3ca3030434 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Thu, 11 Apr 2019 20:17:33 +0200 Subject: PM / Domains: Add genpd governor for CPUs After some preceding changes, PM domains managed by genpd may contain CPU devices, so idle state residency values should be taken into account during the state selection process. [The residency value is the minimum amount of time to be spent by a CPU (or a group of CPUs) in an idle state in order to save more energy than could be saved by picking up a shallower idle state.] For this purpose, add a new genpd governor, pm_domain_cpu_gov, to be used for selecting idle states of PM domains with CPU devices attached either directly or through subdomains. The new governor computes the minimum expected idle duration for all online CPUs attached to a PM domain and its subdomains. Next, it finds the deepest idle state whose target residency is within the expected idle duration and selects it as the target idle state of the domain. It should be noted that the minimum expected idle duration computation is based on the closest timer event information stored in the per-CPU variables cpuidle_devices for all of the CPUs in the domain. That needs to be revisited in future, as obviously there are other reasons why a CPU may be woken up from idle. 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_governor.c | 67 +++++++++++++++++++++++++++++++++++- include/linux/pm_domain.h | 4 +++ 2 files changed, 70 insertions(+), 1 deletion(-) (limited to 'drivers/base/power') diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index 4d07e38a8247..7912bc957244 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -10,6 +10,9 @@ #include #include #include +#include +#include +#include static int dev_update_qos_constraint(struct device *dev, void *data) { @@ -210,8 +213,10 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) struct generic_pm_domain *genpd = pd_to_genpd(pd); struct gpd_link *link; - if (!genpd->max_off_time_changed) + if (!genpd->max_off_time_changed) { + genpd->state_idx = genpd->cached_power_down_state_idx; return genpd->cached_power_down_ok; + } /* * We have to invalidate the cached results for the masters, so @@ -236,6 +241,7 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) genpd->state_idx--; } + genpd->cached_power_down_state_idx = genpd->state_idx; return genpd->cached_power_down_ok; } @@ -244,6 +250,65 @@ static bool always_on_power_down_ok(struct dev_pm_domain *domain) return false; } +#ifdef CONFIG_CPU_IDLE +static bool cpu_power_down_ok(struct dev_pm_domain *pd) +{ + struct generic_pm_domain *genpd = pd_to_genpd(pd); + struct cpuidle_device *dev; + ktime_t domain_wakeup, next_hrtimer; + s64 idle_duration_ns; + int cpu, i; + + /* Validate dev PM QoS constraints. */ + if (!default_power_down_ok(pd)) + return false; + + if (!(genpd->flags & GENPD_FLAG_CPU_DOMAIN)) + return true; + + /* + * Find the next wakeup for any of the online CPUs within the PM domain + * and its subdomains. Note, we only need the genpd->cpus, as it already + * contains a mask of all CPUs from subdomains. + */ + domain_wakeup = ktime_set(KTIME_SEC_MAX, 0); + for_each_cpu_and(cpu, genpd->cpus, cpu_online_mask) { + dev = per_cpu(cpuidle_devices, cpu); + if (dev) { + next_hrtimer = READ_ONCE(dev->next_hrtimer); + if (ktime_before(next_hrtimer, domain_wakeup)) + domain_wakeup = next_hrtimer; + } + } + + /* The minimum idle duration is from now - until the next wakeup. */ + idle_duration_ns = ktime_to_ns(ktime_sub(domain_wakeup, ktime_get())); + if (idle_duration_ns <= 0) + return false; + + /* + * Find the deepest idle state that has its residency value satisfied + * and by also taking into account the power off latency for the state. + * Start at the state picked by the dev PM QoS constraint validation. + */ + i = genpd->state_idx; + do { + if (idle_duration_ns >= (genpd->states[i].residency_ns + + genpd->states[i].power_off_latency_ns)) { + genpd->state_idx = i; + return true; + } + } while (--i >= 0); + + return false; +} + +struct dev_power_governor pm_domain_cpu_gov = { + .suspend_ok = default_suspend_ok, + .power_down_ok = cpu_power_down_ok, +}; +#endif + struct dev_power_governor simple_qos_governor = { .suspend_ok = default_suspend_ok, .power_down_ok = default_power_down_ok, diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index a6e251fe9deb..bc82e74560ee 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -118,6 +118,7 @@ struct generic_pm_domain { s64 max_off_time_ns; /* Maximum allowed "suspended" time. */ bool max_off_time_changed; bool cached_power_down_ok; + bool cached_power_down_state_idx; int (*attach_dev)(struct generic_pm_domain *domain, struct device *dev); void (*detach_dev)(struct generic_pm_domain *domain, @@ -202,6 +203,9 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state); extern struct dev_power_governor simple_qos_governor; extern struct dev_power_governor pm_domain_always_on_gov; +#ifdef CONFIG_CPU_IDLE +extern struct dev_power_governor pm_domain_cpu_gov; +#endif #else static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev) -- cgit v1.2.3