298 lines
6.8 KiB
C
298 lines
6.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2020 Linaro Limited
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*
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* Author: Daniel Lezcano <daniel.lezcano@linaro.org>
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*
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* The DTPM CPU is based on the energy model. It hooks the CPU in the
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* DTPM tree which in turns update the power number by propagating the
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* power number from the CPU energy model information to the parents.
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*
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* The association between the power and the performance state, allows
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* to set the power of the CPU at the OPP granularity.
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*
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* The CPU hotplug is supported and the power numbers will be updated
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* if a CPU is hot plugged / unplugged.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/cpumask.h>
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#include <linux/cpufreq.h>
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#include <linux/cpuhotplug.h>
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#include <linux/dtpm.h>
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#include <linux/energy_model.h>
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#include <linux/of.h>
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#include <linux/pm_qos.h>
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#include <linux/slab.h>
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#include <linux/units.h>
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struct dtpm_cpu {
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struct dtpm dtpm;
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struct freq_qos_request qos_req;
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int cpu;
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};
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static DEFINE_PER_CPU(struct dtpm_cpu *, dtpm_per_cpu);
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static struct dtpm_cpu *to_dtpm_cpu(struct dtpm *dtpm)
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{
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return container_of(dtpm, struct dtpm_cpu, dtpm);
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}
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static u64 set_pd_power_limit(struct dtpm *dtpm, u64 power_limit)
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{
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struct dtpm_cpu *dtpm_cpu = to_dtpm_cpu(dtpm);
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struct em_perf_domain *pd = em_cpu_get(dtpm_cpu->cpu);
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struct cpumask cpus;
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unsigned long freq;
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u64 power;
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int i, nr_cpus;
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cpumask_and(&cpus, cpu_online_mask, to_cpumask(pd->cpus));
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nr_cpus = cpumask_weight(&cpus);
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for (i = 0; i < pd->nr_perf_states; i++) {
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power = pd->table[i].power * nr_cpus;
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if (power > power_limit)
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break;
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}
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freq = pd->table[i - 1].frequency;
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freq_qos_update_request(&dtpm_cpu->qos_req, freq);
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power_limit = pd->table[i - 1].power * nr_cpus;
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return power_limit;
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}
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static u64 scale_pd_power_uw(struct cpumask *pd_mask, u64 power)
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{
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unsigned long max, sum_util = 0;
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int cpu;
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/*
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* The capacity is the same for all CPUs belonging to
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* the same perf domain.
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*/
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max = arch_scale_cpu_capacity(cpumask_first(pd_mask));
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for_each_cpu_and(cpu, pd_mask, cpu_online_mask)
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sum_util += sched_cpu_util(cpu);
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return (power * ((sum_util << 10) / max)) >> 10;
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}
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static u64 get_pd_power_uw(struct dtpm *dtpm)
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{
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struct dtpm_cpu *dtpm_cpu = to_dtpm_cpu(dtpm);
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struct em_perf_domain *pd;
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struct cpumask *pd_mask;
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unsigned long freq;
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int i;
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pd = em_cpu_get(dtpm_cpu->cpu);
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pd_mask = em_span_cpus(pd);
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freq = cpufreq_quick_get(dtpm_cpu->cpu);
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for (i = 0; i < pd->nr_perf_states; i++) {
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if (pd->table[i].frequency < freq)
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continue;
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return scale_pd_power_uw(pd_mask, pd->table[i].power *
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MICROWATT_PER_MILLIWATT);
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}
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return 0;
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}
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static int update_pd_power_uw(struct dtpm *dtpm)
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{
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struct dtpm_cpu *dtpm_cpu = to_dtpm_cpu(dtpm);
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struct em_perf_domain *em = em_cpu_get(dtpm_cpu->cpu);
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struct cpumask cpus;
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int nr_cpus;
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cpumask_and(&cpus, cpu_online_mask, to_cpumask(em->cpus));
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nr_cpus = cpumask_weight(&cpus);
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dtpm->power_min = em->table[0].power;
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dtpm->power_min *= MICROWATT_PER_MILLIWATT;
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dtpm->power_min *= nr_cpus;
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dtpm->power_max = em->table[em->nr_perf_states - 1].power;
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dtpm->power_max *= MICROWATT_PER_MILLIWATT;
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dtpm->power_max *= nr_cpus;
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return 0;
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}
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static void pd_release(struct dtpm *dtpm)
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{
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struct dtpm_cpu *dtpm_cpu = to_dtpm_cpu(dtpm);
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struct cpufreq_policy *policy;
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if (freq_qos_request_active(&dtpm_cpu->qos_req))
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freq_qos_remove_request(&dtpm_cpu->qos_req);
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policy = cpufreq_cpu_get(dtpm_cpu->cpu);
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if (policy) {
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for_each_cpu(dtpm_cpu->cpu, policy->related_cpus)
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per_cpu(dtpm_per_cpu, dtpm_cpu->cpu) = NULL;
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}
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kfree(dtpm_cpu);
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}
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static struct dtpm_ops dtpm_ops = {
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.set_power_uw = set_pd_power_limit,
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.get_power_uw = get_pd_power_uw,
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.update_power_uw = update_pd_power_uw,
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.release = pd_release,
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};
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static int cpuhp_dtpm_cpu_offline(unsigned int cpu)
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{
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struct dtpm_cpu *dtpm_cpu;
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dtpm_cpu = per_cpu(dtpm_per_cpu, cpu);
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if (dtpm_cpu)
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dtpm_update_power(&dtpm_cpu->dtpm);
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return 0;
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}
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static int cpuhp_dtpm_cpu_online(unsigned int cpu)
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{
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struct dtpm_cpu *dtpm_cpu;
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dtpm_cpu = per_cpu(dtpm_per_cpu, cpu);
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if (dtpm_cpu)
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return dtpm_update_power(&dtpm_cpu->dtpm);
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return 0;
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}
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static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
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{
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struct dtpm_cpu *dtpm_cpu;
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struct cpufreq_policy *policy;
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struct em_perf_domain *pd;
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char name[CPUFREQ_NAME_LEN];
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int ret = -ENOMEM;
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dtpm_cpu = per_cpu(dtpm_per_cpu, cpu);
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if (dtpm_cpu)
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return 0;
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policy = cpufreq_cpu_get(cpu);
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if (!policy)
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return 0;
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pd = em_cpu_get(cpu);
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if (!pd || em_is_artificial(pd))
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return -EINVAL;
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dtpm_cpu = kzalloc(sizeof(*dtpm_cpu), GFP_KERNEL);
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if (!dtpm_cpu)
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return -ENOMEM;
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dtpm_init(&dtpm_cpu->dtpm, &dtpm_ops);
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dtpm_cpu->cpu = cpu;
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for_each_cpu(cpu, policy->related_cpus)
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per_cpu(dtpm_per_cpu, cpu) = dtpm_cpu;
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snprintf(name, sizeof(name), "cpu%d-cpufreq", dtpm_cpu->cpu);
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ret = dtpm_register(name, &dtpm_cpu->dtpm, parent);
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if (ret)
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goto out_kfree_dtpm_cpu;
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ret = freq_qos_add_request(&policy->constraints,
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&dtpm_cpu->qos_req, FREQ_QOS_MAX,
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pd->table[pd->nr_perf_states - 1].frequency);
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if (ret)
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goto out_dtpm_unregister;
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return 0;
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out_dtpm_unregister:
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dtpm_unregister(&dtpm_cpu->dtpm);
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dtpm_cpu = NULL;
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out_kfree_dtpm_cpu:
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for_each_cpu(cpu, policy->related_cpus)
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per_cpu(dtpm_per_cpu, cpu) = NULL;
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kfree(dtpm_cpu);
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return ret;
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}
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static int dtpm_cpu_setup(struct dtpm *dtpm, struct device_node *np)
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{
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int cpu;
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cpu = of_cpu_node_to_id(np);
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if (cpu < 0)
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return 0;
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return __dtpm_cpu_setup(cpu, dtpm);
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}
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static int dtpm_cpu_init(void)
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{
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int ret;
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/*
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* The callbacks at CPU hotplug time are calling
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* dtpm_update_power() which in turns calls update_pd_power().
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*
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* The function update_pd_power() uses the online mask to
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* figure out the power consumption limits.
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*
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* At CPUHP_AP_ONLINE_DYN, the CPU is present in the CPU
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* online mask when the cpuhp_dtpm_cpu_online function is
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* called, but the CPU is still in the online mask for the
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* tear down callback. So the power can not be updated when
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* the CPU is unplugged.
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*
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* At CPUHP_AP_DTPM_CPU_DEAD, the situation is the opposite as
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* above. The CPU online mask is not up to date when the CPU
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* is plugged in.
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*
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* For this reason, we need to call the online and offline
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* callbacks at different moments when the CPU online mask is
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* consistent with the power numbers we want to update.
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*/
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ret = cpuhp_setup_state(CPUHP_AP_DTPM_CPU_DEAD, "dtpm_cpu:offline",
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NULL, cpuhp_dtpm_cpu_offline);
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if (ret < 0)
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return ret;
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ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "dtpm_cpu:online",
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cpuhp_dtpm_cpu_online, NULL);
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if (ret < 0)
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return ret;
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return 0;
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}
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static void dtpm_cpu_exit(void)
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{
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cpuhp_remove_state_nocalls(CPUHP_AP_ONLINE_DYN);
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cpuhp_remove_state_nocalls(CPUHP_AP_DTPM_CPU_DEAD);
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}
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struct dtpm_subsys_ops dtpm_cpu_ops = {
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.name = KBUILD_MODNAME,
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.init = dtpm_cpu_init,
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.exit = dtpm_cpu_exit,
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.setup = dtpm_cpu_setup,
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};
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