This registers the notifiers for min/max frequency constraints with the PM QoS framework. The constraints are also taken into consideration in cpufreq_set_policy().
This also relocates cpufreq_policy_put_kobj() as it is required to be called from cpufreq_policy_alloc() now. No constraints are added until now though. Signed-off-by: Viresh Kumar <[email protected]> --- drivers/cpufreq/cpufreq.c | 135 +++++++++++++++++++++++++++++++------- include/linux/cpufreq.h | 4 ++ 2 files changed, 116 insertions(+), 23 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 0e626b00053b..d615bf35ac00 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -26,6 +26,7 @@ #include <linux/kernel_stat.h> #include <linux/module.h> #include <linux/mutex.h> +#include <linux/pm_qos.h> #include <linux/slab.h> #include <linux/suspend.h> #include <linux/syscore_ops.h> @@ -1082,11 +1083,77 @@ static void handle_update(struct work_struct *work) cpufreq_update_policy(cpu); } +static void cpufreq_update_freq_work(struct work_struct *work) +{ + struct cpufreq_policy *policy = + container_of(work, struct cpufreq_policy, req_work); + struct cpufreq_policy new_policy = *policy; + + /* We should read constraint values from QoS layer */ + new_policy.min = 0; + new_policy.max = UINT_MAX; + + down_write(&policy->rwsem); + + if (!policy_is_inactive(policy)) + cpufreq_set_policy(policy, &new_policy); + + up_write(&policy->rwsem); +} + +static int cpufreq_update_freq(struct cpufreq_policy *policy) +{ + schedule_work(&policy->req_work); + return 0; +} + +static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq, + void *data) +{ + struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min); + + return cpufreq_update_freq(policy); +} + +static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq, + void *data) +{ + struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max); + + return cpufreq_update_freq(policy); +} + +static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) +{ + struct kobject *kobj; + struct completion *cmp; + + down_write(&policy->rwsem); + cpufreq_stats_free_table(policy); + kobj = &policy->kobj; + cmp = &policy->kobj_unregister; + up_write(&policy->rwsem); + kobject_put(kobj); + + /* + * We need to make sure that the underlying kobj is + * actually not referenced anymore by anybody before we + * proceed with unloading. + */ + pr_debug("waiting for dropping of refcount\n"); + wait_for_completion(cmp); + pr_debug("wait complete\n"); +} + static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) { struct cpufreq_policy *policy; + struct device *dev = get_cpu_device(cpu); int ret; + if (!dev) + return NULL; + policy = kzalloc(sizeof(*policy), GFP_KERNEL); if (!policy) return NULL; @@ -1103,20 +1170,45 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, cpufreq_global_kobject, "policy%u", cpu); if (ret) { - pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret); + dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret); goto err_free_real_cpus; } + policy->nb_min.notifier_call = cpufreq_notifier_min; + policy->nb_max.notifier_call = cpufreq_notifier_max; + + ret = dev_pm_qos_add_notifier(dev, &policy->nb_min, + DEV_PM_QOS_MIN_FREQUENCY); + if (ret) { + dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n", + ret, cpumask_pr_args(policy->cpus)); + goto err_kobj_remove; + } + + ret = dev_pm_qos_add_notifier(dev, &policy->nb_max, + DEV_PM_QOS_MAX_FREQUENCY); + if (ret) { + dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n", + ret, cpumask_pr_args(policy->cpus)); + goto err_min_qos_notifier; + } + INIT_LIST_HEAD(&policy->policy_list); init_rwsem(&policy->rwsem); spin_lock_init(&policy->transition_lock); init_waitqueue_head(&policy->transition_wait); init_completion(&policy->kobj_unregister); INIT_WORK(&policy->update, handle_update); + INIT_WORK(&policy->req_work, cpufreq_update_freq_work); policy->cpu = cpu; return policy; +err_min_qos_notifier: + dev_pm_qos_remove_notifier(dev, &policy->nb_min, + DEV_PM_QOS_MIN_FREQUENCY); +err_kobj_remove: + cpufreq_policy_put_kobj(policy); err_free_real_cpus: free_cpumask_var(policy->real_cpus); err_free_rcpumask: @@ -1129,30 +1221,9 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) return NULL; } -static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) -{ - struct kobject *kobj; - struct completion *cmp; - - down_write(&policy->rwsem); - cpufreq_stats_free_table(policy); - kobj = &policy->kobj; - cmp = &policy->kobj_unregister; - up_write(&policy->rwsem); - kobject_put(kobj); - - /* - * We need to make sure that the underlying kobj is - * actually not referenced anymore by anybody before we - * proceed with unloading. - */ - pr_debug("waiting for dropping of refcount\n"); - wait_for_completion(cmp); - pr_debug("wait complete\n"); -} - static void cpufreq_policy_free(struct cpufreq_policy *policy) { + struct device *dev = get_cpu_device(policy->cpu); unsigned long flags; int cpu; @@ -1164,6 +1235,10 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy) per_cpu(cpufreq_cpu_data, cpu) = NULL; write_unlock_irqrestore(&cpufreq_driver_lock, flags); + dev_pm_qos_remove_notifier(dev, &policy->nb_max, + DEV_PM_QOS_MAX_FREQUENCY); + dev_pm_qos_remove_notifier(dev, &policy->nb_min, + DEV_PM_QOS_MIN_FREQUENCY); cpufreq_policy_put_kobj(policy); free_cpumask_var(policy->real_cpus); free_cpumask_var(policy->related_cpus); @@ -2239,6 +2314,8 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, struct cpufreq_policy *new_policy) { struct cpufreq_governor *old_gov; + struct device *cpu_dev = get_cpu_device(policy->cpu); + unsigned long min, max; int ret; pr_debug("setting new policy for CPU %u: %u - %u kHz\n", @@ -2253,11 +2330,23 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, if (new_policy->min > new_policy->max) return -EINVAL; + min = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MIN_FREQUENCY); + max = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MAX_FREQUENCY); + + if (min > new_policy->min) + new_policy->min = min; + if (max < new_policy->max) + new_policy->max = max; + /* verify the cpu speed can be set within this limit */ ret = cpufreq_driver->verify(new_policy); if (ret) return ret; + /* + * The notifier-chain shall be removed once all the users of + * CPUFREQ_ADJUST are moved to use the QoS framework. + */ /* adjust if necessary - all reasons */ blocking_notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST, new_policy); diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index b160e98076e3..f8f48d8a9b52 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -90,6 +90,7 @@ struct cpufreq_policy { struct work_struct update; /* if update_policy() needs to be * called, but you're in IRQ context */ + struct work_struct req_work; struct cpufreq_user_policy user_policy; struct cpufreq_frequency_table *freq_table; @@ -154,6 +155,9 @@ struct cpufreq_policy { /* Pointer to the cooling device if used for thermal mitigation */ struct thermal_cooling_device *cdev; + + struct notifier_block nb_min; + struct notifier_block nb_max; }; /* Only for ACPI */ -- 2.21.0.rc0.269.g1a574e7a288b
