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![Igor Stoppa](/assets/img/avatar_default.png)
WARN_ON() already contains an unlikely(), so it's not necessary to wrap it into another. Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2608 lines
67 KiB
C
2608 lines
67 KiB
C
/*
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* linux/drivers/cpufreq/cpufreq.c
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*
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* Copyright (C) 2001 Russell King
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* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
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* (C) 2013 Viresh Kumar <viresh.kumar@linaro.org>
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*
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* Oct 2005 - Ashok Raj <ashok.raj@intel.com>
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* Added handling for CPU hotplug
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* Feb 2006 - Jacob Shin <jacob.shin@amd.com>
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* Fix handling for CPU hotplug -- affected CPUs
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/cpu.h>
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#include <linux/cpufreq.h>
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/kernel_stat.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/suspend.h>
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#include <linux/syscore_ops.h>
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#include <linux/tick.h>
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#include <trace/events/power.h>
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static LIST_HEAD(cpufreq_policy_list);
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static inline bool policy_is_inactive(struct cpufreq_policy *policy)
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{
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return cpumask_empty(policy->cpus);
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}
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/* Macros to iterate over CPU policies */
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#define for_each_suitable_policy(__policy, __active) \
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list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
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if ((__active) == !policy_is_inactive(__policy))
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#define for_each_active_policy(__policy) \
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for_each_suitable_policy(__policy, true)
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#define for_each_inactive_policy(__policy) \
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for_each_suitable_policy(__policy, false)
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#define for_each_policy(__policy) \
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list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
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/* Iterate over governors */
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static LIST_HEAD(cpufreq_governor_list);
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#define for_each_governor(__governor) \
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list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
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/**
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* The "cpufreq driver" - the arch- or hardware-dependent low
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* level driver of CPUFreq support, and its spinlock. This lock
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* also protects the cpufreq_cpu_data array.
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*/
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static struct cpufreq_driver *cpufreq_driver;
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static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
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static DEFINE_RWLOCK(cpufreq_driver_lock);
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/* Flag to suspend/resume CPUFreq governors */
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static bool cpufreq_suspended;
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static inline bool has_target(void)
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{
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return cpufreq_driver->target_index || cpufreq_driver->target;
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}
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/* internal prototypes */
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static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
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static int cpufreq_init_governor(struct cpufreq_policy *policy);
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static void cpufreq_exit_governor(struct cpufreq_policy *policy);
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static int cpufreq_start_governor(struct cpufreq_policy *policy);
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static void cpufreq_stop_governor(struct cpufreq_policy *policy);
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static void cpufreq_governor_limits(struct cpufreq_policy *policy);
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/**
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* Two notifier lists: the "policy" list is involved in the
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* validation process for a new CPU frequency policy; the
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* "transition" list for kernel code that needs to handle
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* changes to devices when the CPU clock speed changes.
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* The mutex locks both lists.
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*/
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static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
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SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list);
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static int off __read_mostly;
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static int cpufreq_disabled(void)
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{
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return off;
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}
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void disable_cpufreq(void)
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{
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off = 1;
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}
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static DEFINE_MUTEX(cpufreq_governor_mutex);
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bool have_governor_per_policy(void)
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{
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return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
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}
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EXPORT_SYMBOL_GPL(have_governor_per_policy);
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struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
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{
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if (have_governor_per_policy())
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return &policy->kobj;
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else
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return cpufreq_global_kobject;
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}
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EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
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static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
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{
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u64 idle_time;
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u64 cur_wall_time;
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u64 busy_time;
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cur_wall_time = jiffies64_to_nsecs(get_jiffies_64());
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busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
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busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
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busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
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busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
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busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
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busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
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idle_time = cur_wall_time - busy_time;
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if (wall)
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*wall = div_u64(cur_wall_time, NSEC_PER_USEC);
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return div_u64(idle_time, NSEC_PER_USEC);
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}
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u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
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{
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u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
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if (idle_time == -1ULL)
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return get_cpu_idle_time_jiffy(cpu, wall);
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else if (!io_busy)
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idle_time += get_cpu_iowait_time_us(cpu, wall);
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return idle_time;
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}
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EXPORT_SYMBOL_GPL(get_cpu_idle_time);
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__weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
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unsigned long max_freq)
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{
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}
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EXPORT_SYMBOL_GPL(arch_set_freq_scale);
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/*
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* This is a generic cpufreq init() routine which can be used by cpufreq
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* drivers of SMP systems. It will do following:
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* - validate & show freq table passed
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* - set policies transition latency
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* - policy->cpus with all possible CPUs
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*/
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int cpufreq_generic_init(struct cpufreq_policy *policy,
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struct cpufreq_frequency_table *table,
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unsigned int transition_latency)
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{
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policy->freq_table = table;
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policy->cpuinfo.transition_latency = transition_latency;
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/*
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* The driver only supports the SMP configuration where all processors
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* share the clock and voltage and clock.
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*/
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cpumask_setall(policy->cpus);
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return 0;
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}
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EXPORT_SYMBOL_GPL(cpufreq_generic_init);
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struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
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{
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struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
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return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
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}
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EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
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unsigned int cpufreq_generic_get(unsigned int cpu)
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{
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struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
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if (!policy || IS_ERR(policy->clk)) {
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pr_err("%s: No %s associated to cpu: %d\n",
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__func__, policy ? "clk" : "policy", cpu);
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return 0;
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}
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return clk_get_rate(policy->clk) / 1000;
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}
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EXPORT_SYMBOL_GPL(cpufreq_generic_get);
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/**
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* cpufreq_cpu_get: returns policy for a cpu and marks it busy.
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*
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* @cpu: cpu to find policy for.
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*
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* This returns policy for 'cpu', returns NULL if it doesn't exist.
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* It also increments the kobject reference count to mark it busy and so would
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* require a corresponding call to cpufreq_cpu_put() to decrement it back.
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* If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be
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* freed as that depends on the kobj count.
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*
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* Return: A valid policy on success, otherwise NULL on failure.
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*/
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struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
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{
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struct cpufreq_policy *policy = NULL;
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unsigned long flags;
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if (WARN_ON(cpu >= nr_cpu_ids))
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return NULL;
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/* get the cpufreq driver */
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read_lock_irqsave(&cpufreq_driver_lock, flags);
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if (cpufreq_driver) {
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/* get the CPU */
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policy = cpufreq_cpu_get_raw(cpu);
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if (policy)
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kobject_get(&policy->kobj);
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}
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read_unlock_irqrestore(&cpufreq_driver_lock, flags);
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return policy;
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}
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EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
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/**
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* cpufreq_cpu_put: Decrements the usage count of a policy
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*
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* @policy: policy earlier returned by cpufreq_cpu_get().
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*
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* This decrements the kobject reference count incremented earlier by calling
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* cpufreq_cpu_get().
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*/
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void cpufreq_cpu_put(struct cpufreq_policy *policy)
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{
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kobject_put(&policy->kobj);
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}
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EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
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/*********************************************************************
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* EXTERNALLY AFFECTING FREQUENCY CHANGES *
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*********************************************************************/
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/**
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* adjust_jiffies - adjust the system "loops_per_jiffy"
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*
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* This function alters the system "loops_per_jiffy" for the clock
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* speed change. Note that loops_per_jiffy cannot be updated on SMP
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* systems as each CPU might be scaled differently. So, use the arch
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* per-CPU loops_per_jiffy value wherever possible.
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*/
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static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
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{
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#ifndef CONFIG_SMP
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static unsigned long l_p_j_ref;
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static unsigned int l_p_j_ref_freq;
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if (ci->flags & CPUFREQ_CONST_LOOPS)
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return;
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if (!l_p_j_ref_freq) {
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l_p_j_ref = loops_per_jiffy;
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l_p_j_ref_freq = ci->old;
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pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
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l_p_j_ref, l_p_j_ref_freq);
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}
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if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
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loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
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ci->new);
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pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
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loops_per_jiffy, ci->new);
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}
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#endif
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}
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/**
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* cpufreq_notify_transition - Notify frequency transition and adjust_jiffies.
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* @policy: cpufreq policy to enable fast frequency switching for.
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* @freqs: contain details of the frequency update.
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* @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
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*
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* This function calls the transition notifiers and the "adjust_jiffies"
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* function. It is called twice on all CPU frequency changes that have
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* external effects.
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*/
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static void cpufreq_notify_transition(struct cpufreq_policy *policy,
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struct cpufreq_freqs *freqs,
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unsigned int state)
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{
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BUG_ON(irqs_disabled());
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if (cpufreq_disabled())
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return;
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freqs->flags = cpufreq_driver->flags;
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pr_debug("notification %u of frequency transition to %u kHz\n",
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state, freqs->new);
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switch (state) {
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case CPUFREQ_PRECHANGE:
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/*
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* Detect if the driver reported a value as "old frequency"
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* which is not equal to what the cpufreq core thinks is
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* "old frequency".
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*/
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if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
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if (policy->cur && (policy->cur != freqs->old)) {
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pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
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freqs->old, policy->cur);
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freqs->old = policy->cur;
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}
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}
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for_each_cpu(freqs->cpu, policy->cpus) {
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srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
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CPUFREQ_PRECHANGE, freqs);
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}
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adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
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break;
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case CPUFREQ_POSTCHANGE:
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adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
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pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new,
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cpumask_pr_args(policy->cpus));
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for_each_cpu(freqs->cpu, policy->cpus) {
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trace_cpu_frequency(freqs->new, freqs->cpu);
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srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
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CPUFREQ_POSTCHANGE, freqs);
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}
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cpufreq_stats_record_transition(policy, freqs->new);
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policy->cur = freqs->new;
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}
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}
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/* Do post notifications when there are chances that transition has failed */
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static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
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struct cpufreq_freqs *freqs, int transition_failed)
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{
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cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
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if (!transition_failed)
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return;
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swap(freqs->old, freqs->new);
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cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
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cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
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}
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void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
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struct cpufreq_freqs *freqs)
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{
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/*
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* Catch double invocations of _begin() which lead to self-deadlock.
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* ASYNC_NOTIFICATION drivers are left out because the cpufreq core
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* doesn't invoke _begin() on their behalf, and hence the chances of
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* double invocations are very low. Moreover, there are scenarios
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* where these checks can emit false-positive warnings in these
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* drivers; so we avoid that by skipping them altogether.
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*/
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WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
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&& current == policy->transition_task);
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wait:
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wait_event(policy->transition_wait, !policy->transition_ongoing);
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spin_lock(&policy->transition_lock);
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if (unlikely(policy->transition_ongoing)) {
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spin_unlock(&policy->transition_lock);
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goto wait;
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}
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policy->transition_ongoing = true;
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policy->transition_task = current;
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spin_unlock(&policy->transition_lock);
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cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
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}
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EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
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void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
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struct cpufreq_freqs *freqs, int transition_failed)
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{
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if (WARN_ON(!policy->transition_ongoing))
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return;
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cpufreq_notify_post_transition(policy, freqs, transition_failed);
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policy->transition_ongoing = false;
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policy->transition_task = NULL;
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wake_up(&policy->transition_wait);
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}
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EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
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/*
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* Fast frequency switching status count. Positive means "enabled", negative
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* means "disabled" and 0 means "not decided yet".
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*/
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static int cpufreq_fast_switch_count;
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static DEFINE_MUTEX(cpufreq_fast_switch_lock);
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static void cpufreq_list_transition_notifiers(void)
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{
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struct notifier_block *nb;
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pr_info("Registered transition notifiers:\n");
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mutex_lock(&cpufreq_transition_notifier_list.mutex);
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for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
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pr_info("%pF\n", nb->notifier_call);
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mutex_unlock(&cpufreq_transition_notifier_list.mutex);
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}
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/**
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* cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
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* @policy: cpufreq policy to enable fast frequency switching for.
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*
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* Try to enable fast frequency switching for @policy.
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*
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* The attempt will fail if there is at least one transition notifier registered
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* at this point, as fast frequency switching is quite fundamentally at odds
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* with transition notifiers. Thus if successful, it will make registration of
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* transition notifiers fail going forward.
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*/
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void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
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{
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lockdep_assert_held(&policy->rwsem);
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if (!policy->fast_switch_possible)
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return;
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mutex_lock(&cpufreq_fast_switch_lock);
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if (cpufreq_fast_switch_count >= 0) {
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cpufreq_fast_switch_count++;
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policy->fast_switch_enabled = true;
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} else {
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pr_warn("CPU%u: Fast frequency switching not enabled\n",
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policy->cpu);
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cpufreq_list_transition_notifiers();
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}
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mutex_unlock(&cpufreq_fast_switch_lock);
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}
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EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
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|
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/**
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* cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
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* @policy: cpufreq policy to disable fast frequency switching for.
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*/
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void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
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{
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mutex_lock(&cpufreq_fast_switch_lock);
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if (policy->fast_switch_enabled) {
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policy->fast_switch_enabled = false;
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|
if (!WARN_ON(cpufreq_fast_switch_count <= 0))
|
|
cpufreq_fast_switch_count--;
|
|
}
|
|
mutex_unlock(&cpufreq_fast_switch_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch);
|
|
|
|
/**
|
|
* cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
|
|
* one.
|
|
* @target_freq: target frequency to resolve.
|
|
*
|
|
* The target to driver frequency mapping is cached in the policy.
|
|
*
|
|
* Return: Lowest driver-supported frequency greater than or equal to the
|
|
* given target_freq, subject to policy (min/max) and driver limitations.
|
|
*/
|
|
unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
|
|
unsigned int target_freq)
|
|
{
|
|
target_freq = clamp_val(target_freq, policy->min, policy->max);
|
|
policy->cached_target_freq = target_freq;
|
|
|
|
if (cpufreq_driver->target_index) {
|
|
int idx;
|
|
|
|
idx = cpufreq_frequency_table_target(policy, target_freq,
|
|
CPUFREQ_RELATION_L);
|
|
policy->cached_resolved_idx = idx;
|
|
return policy->freq_table[idx].frequency;
|
|
}
|
|
|
|
if (cpufreq_driver->resolve_freq)
|
|
return cpufreq_driver->resolve_freq(policy, target_freq);
|
|
|
|
return target_freq;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
|
|
|
|
unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
|
|
{
|
|
unsigned int latency;
|
|
|
|
if (policy->transition_delay_us)
|
|
return policy->transition_delay_us;
|
|
|
|
latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
|
|
if (latency) {
|
|
/*
|
|
* For platforms that can change the frequency very fast (< 10
|
|
* us), the above formula gives a decent transition delay. But
|
|
* for platforms where transition_latency is in milliseconds, it
|
|
* ends up giving unrealistic values.
|
|
*
|
|
* Cap the default transition delay to 10 ms, which seems to be
|
|
* a reasonable amount of time after which we should reevaluate
|
|
* the frequency.
|
|
*/
|
|
return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000);
|
|
}
|
|
|
|
return LATENCY_MULTIPLIER;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us);
|
|
|
|
/*********************************************************************
|
|
* SYSFS INTERFACE *
|
|
*********************************************************************/
|
|
static ssize_t show_boost(struct kobject *kobj,
|
|
struct attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
|
|
}
|
|
|
|
static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
int ret, enable;
|
|
|
|
ret = sscanf(buf, "%d", &enable);
|
|
if (ret != 1 || enable < 0 || enable > 1)
|
|
return -EINVAL;
|
|
|
|
if (cpufreq_boost_trigger_state(enable)) {
|
|
pr_err("%s: Cannot %s BOOST!\n",
|
|
__func__, enable ? "enable" : "disable");
|
|
return -EINVAL;
|
|
}
|
|
|
|
pr_debug("%s: cpufreq BOOST %s\n",
|
|
__func__, enable ? "enabled" : "disabled");
|
|
|
|
return count;
|
|
}
|
|
define_one_global_rw(boost);
|
|
|
|
static struct cpufreq_governor *find_governor(const char *str_governor)
|
|
{
|
|
struct cpufreq_governor *t;
|
|
|
|
for_each_governor(t)
|
|
if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
|
|
return t;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_parse_governor - parse a governor string
|
|
*/
|
|
static int cpufreq_parse_governor(char *str_governor,
|
|
struct cpufreq_policy *policy)
|
|
{
|
|
if (cpufreq_driver->setpolicy) {
|
|
if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
|
|
policy->policy = CPUFREQ_POLICY_PERFORMANCE;
|
|
return 0;
|
|
}
|
|
|
|
if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
|
|
policy->policy = CPUFREQ_POLICY_POWERSAVE;
|
|
return 0;
|
|
}
|
|
} else {
|
|
struct cpufreq_governor *t;
|
|
|
|
mutex_lock(&cpufreq_governor_mutex);
|
|
|
|
t = find_governor(str_governor);
|
|
if (!t) {
|
|
int ret;
|
|
|
|
mutex_unlock(&cpufreq_governor_mutex);
|
|
|
|
ret = request_module("cpufreq_%s", str_governor);
|
|
if (ret)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&cpufreq_governor_mutex);
|
|
|
|
t = find_governor(str_governor);
|
|
}
|
|
if (t && !try_module_get(t->owner))
|
|
t = NULL;
|
|
|
|
mutex_unlock(&cpufreq_governor_mutex);
|
|
|
|
if (t) {
|
|
policy->governor = t;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_per_cpu_attr_read() / show_##file_name() -
|
|
* print out cpufreq information
|
|
*
|
|
* Write out information from cpufreq_driver->policy[cpu]; object must be
|
|
* "unsigned int".
|
|
*/
|
|
|
|
#define show_one(file_name, object) \
|
|
static ssize_t show_##file_name \
|
|
(struct cpufreq_policy *policy, char *buf) \
|
|
{ \
|
|
return sprintf(buf, "%u\n", policy->object); \
|
|
}
|
|
|
|
show_one(cpuinfo_min_freq, cpuinfo.min_freq);
|
|
show_one(cpuinfo_max_freq, cpuinfo.max_freq);
|
|
show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
|
|
show_one(scaling_min_freq, min);
|
|
show_one(scaling_max_freq, max);
|
|
|
|
__weak unsigned int arch_freq_get_on_cpu(int cpu)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
|
|
{
|
|
ssize_t ret;
|
|
unsigned int freq;
|
|
|
|
freq = arch_freq_get_on_cpu(policy->cpu);
|
|
if (freq)
|
|
ret = sprintf(buf, "%u\n", freq);
|
|
else if (cpufreq_driver && cpufreq_driver->setpolicy &&
|
|
cpufreq_driver->get)
|
|
ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
|
|
else
|
|
ret = sprintf(buf, "%u\n", policy->cur);
|
|
return ret;
|
|
}
|
|
|
|
static int cpufreq_set_policy(struct cpufreq_policy *policy,
|
|
struct cpufreq_policy *new_policy);
|
|
|
|
/**
|
|
* cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
|
|
*/
|
|
#define store_one(file_name, object) \
|
|
static ssize_t store_##file_name \
|
|
(struct cpufreq_policy *policy, const char *buf, size_t count) \
|
|
{ \
|
|
int ret, temp; \
|
|
struct cpufreq_policy new_policy; \
|
|
\
|
|
memcpy(&new_policy, policy, sizeof(*policy)); \
|
|
new_policy.min = policy->user_policy.min; \
|
|
new_policy.max = policy->user_policy.max; \
|
|
\
|
|
ret = sscanf(buf, "%u", &new_policy.object); \
|
|
if (ret != 1) \
|
|
return -EINVAL; \
|
|
\
|
|
temp = new_policy.object; \
|
|
ret = cpufreq_set_policy(policy, &new_policy); \
|
|
if (!ret) \
|
|
policy->user_policy.object = temp; \
|
|
\
|
|
return ret ? ret : count; \
|
|
}
|
|
|
|
store_one(scaling_min_freq, min);
|
|
store_one(scaling_max_freq, max);
|
|
|
|
/**
|
|
* show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
|
|
*/
|
|
static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
|
|
char *buf)
|
|
{
|
|
unsigned int cur_freq = __cpufreq_get(policy);
|
|
|
|
if (cur_freq)
|
|
return sprintf(buf, "%u\n", cur_freq);
|
|
|
|
return sprintf(buf, "<unknown>\n");
|
|
}
|
|
|
|
/**
|
|
* show_scaling_governor - show the current policy for the specified CPU
|
|
*/
|
|
static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
|
|
{
|
|
if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
|
|
return sprintf(buf, "powersave\n");
|
|
else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
|
|
return sprintf(buf, "performance\n");
|
|
else if (policy->governor)
|
|
return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
|
|
policy->governor->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* store_scaling_governor - store policy for the specified CPU
|
|
*/
|
|
static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
|
|
const char *buf, size_t count)
|
|
{
|
|
int ret;
|
|
char str_governor[16];
|
|
struct cpufreq_policy new_policy;
|
|
|
|
memcpy(&new_policy, policy, sizeof(*policy));
|
|
|
|
ret = sscanf(buf, "%15s", str_governor);
|
|
if (ret != 1)
|
|
return -EINVAL;
|
|
|
|
if (cpufreq_parse_governor(str_governor, &new_policy))
|
|
return -EINVAL;
|
|
|
|
ret = cpufreq_set_policy(policy, &new_policy);
|
|
|
|
if (new_policy.governor)
|
|
module_put(new_policy.governor->owner);
|
|
|
|
return ret ? ret : count;
|
|
}
|
|
|
|
/**
|
|
* show_scaling_driver - show the cpufreq driver currently loaded
|
|
*/
|
|
static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
|
|
{
|
|
return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
|
|
}
|
|
|
|
/**
|
|
* show_scaling_available_governors - show the available CPUfreq governors
|
|
*/
|
|
static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
|
|
char *buf)
|
|
{
|
|
ssize_t i = 0;
|
|
struct cpufreq_governor *t;
|
|
|
|
if (!has_target()) {
|
|
i += sprintf(buf, "performance powersave");
|
|
goto out;
|
|
}
|
|
|
|
for_each_governor(t) {
|
|
if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
|
|
- (CPUFREQ_NAME_LEN + 2)))
|
|
goto out;
|
|
i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
|
|
}
|
|
out:
|
|
i += sprintf(&buf[i], "\n");
|
|
return i;
|
|
}
|
|
|
|
ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
|
|
{
|
|
ssize_t i = 0;
|
|
unsigned int cpu;
|
|
|
|
for_each_cpu(cpu, mask) {
|
|
if (i)
|
|
i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
|
|
i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
|
|
if (i >= (PAGE_SIZE - 5))
|
|
break;
|
|
}
|
|
i += sprintf(&buf[i], "\n");
|
|
return i;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
|
|
|
|
/**
|
|
* show_related_cpus - show the CPUs affected by each transition even if
|
|
* hw coordination is in use
|
|
*/
|
|
static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
|
|
{
|
|
return cpufreq_show_cpus(policy->related_cpus, buf);
|
|
}
|
|
|
|
/**
|
|
* show_affected_cpus - show the CPUs affected by each transition
|
|
*/
|
|
static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
|
|
{
|
|
return cpufreq_show_cpus(policy->cpus, buf);
|
|
}
|
|
|
|
static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
|
|
const char *buf, size_t count)
|
|
{
|
|
unsigned int freq = 0;
|
|
unsigned int ret;
|
|
|
|
if (!policy->governor || !policy->governor->store_setspeed)
|
|
return -EINVAL;
|
|
|
|
ret = sscanf(buf, "%u", &freq);
|
|
if (ret != 1)
|
|
return -EINVAL;
|
|
|
|
policy->governor->store_setspeed(policy, freq);
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
|
|
{
|
|
if (!policy->governor || !policy->governor->show_setspeed)
|
|
return sprintf(buf, "<unsupported>\n");
|
|
|
|
return policy->governor->show_setspeed(policy, buf);
|
|
}
|
|
|
|
/**
|
|
* show_bios_limit - show the current cpufreq HW/BIOS limitation
|
|
*/
|
|
static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
|
|
{
|
|
unsigned int limit;
|
|
int ret;
|
|
if (cpufreq_driver->bios_limit) {
|
|
ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
|
|
if (!ret)
|
|
return sprintf(buf, "%u\n", limit);
|
|
}
|
|
return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
|
|
}
|
|
|
|
cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
|
|
cpufreq_freq_attr_ro(cpuinfo_min_freq);
|
|
cpufreq_freq_attr_ro(cpuinfo_max_freq);
|
|
cpufreq_freq_attr_ro(cpuinfo_transition_latency);
|
|
cpufreq_freq_attr_ro(scaling_available_governors);
|
|
cpufreq_freq_attr_ro(scaling_driver);
|
|
cpufreq_freq_attr_ro(scaling_cur_freq);
|
|
cpufreq_freq_attr_ro(bios_limit);
|
|
cpufreq_freq_attr_ro(related_cpus);
|
|
cpufreq_freq_attr_ro(affected_cpus);
|
|
cpufreq_freq_attr_rw(scaling_min_freq);
|
|
cpufreq_freq_attr_rw(scaling_max_freq);
|
|
cpufreq_freq_attr_rw(scaling_governor);
|
|
cpufreq_freq_attr_rw(scaling_setspeed);
|
|
|
|
static struct attribute *default_attrs[] = {
|
|
&cpuinfo_min_freq.attr,
|
|
&cpuinfo_max_freq.attr,
|
|
&cpuinfo_transition_latency.attr,
|
|
&scaling_min_freq.attr,
|
|
&scaling_max_freq.attr,
|
|
&affected_cpus.attr,
|
|
&related_cpus.attr,
|
|
&scaling_governor.attr,
|
|
&scaling_driver.attr,
|
|
&scaling_available_governors.attr,
|
|
&scaling_setspeed.attr,
|
|
NULL
|
|
};
|
|
|
|
#define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
|
|
#define to_attr(a) container_of(a, struct freq_attr, attr)
|
|
|
|
static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
|
|
{
|
|
struct cpufreq_policy *policy = to_policy(kobj);
|
|
struct freq_attr *fattr = to_attr(attr);
|
|
ssize_t ret;
|
|
|
|
down_read(&policy->rwsem);
|
|
ret = fattr->show(policy, buf);
|
|
up_read(&policy->rwsem);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t store(struct kobject *kobj, struct attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct cpufreq_policy *policy = to_policy(kobj);
|
|
struct freq_attr *fattr = to_attr(attr);
|
|
ssize_t ret = -EINVAL;
|
|
|
|
/*
|
|
* cpus_read_trylock() is used here to work around a circular lock
|
|
* dependency problem with respect to the cpufreq_register_driver().
|
|
*/
|
|
if (!cpus_read_trylock())
|
|
return -EBUSY;
|
|
|
|
if (cpu_online(policy->cpu)) {
|
|
down_write(&policy->rwsem);
|
|
ret = fattr->store(policy, buf, count);
|
|
up_write(&policy->rwsem);
|
|
}
|
|
|
|
cpus_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void cpufreq_sysfs_release(struct kobject *kobj)
|
|
{
|
|
struct cpufreq_policy *policy = to_policy(kobj);
|
|
pr_debug("last reference is dropped\n");
|
|
complete(&policy->kobj_unregister);
|
|
}
|
|
|
|
static const struct sysfs_ops sysfs_ops = {
|
|
.show = show,
|
|
.store = store,
|
|
};
|
|
|
|
static struct kobj_type ktype_cpufreq = {
|
|
.sysfs_ops = &sysfs_ops,
|
|
.default_attrs = default_attrs,
|
|
.release = cpufreq_sysfs_release,
|
|
};
|
|
|
|
static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
|
|
{
|
|
struct device *dev = get_cpu_device(cpu);
|
|
|
|
if (!dev)
|
|
return;
|
|
|
|
if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
|
|
return;
|
|
|
|
dev_dbg(dev, "%s: Adding symlink\n", __func__);
|
|
if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"))
|
|
dev_err(dev, "cpufreq symlink creation failed\n");
|
|
}
|
|
|
|
static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
|
|
struct device *dev)
|
|
{
|
|
dev_dbg(dev, "%s: Removing symlink\n", __func__);
|
|
sysfs_remove_link(&dev->kobj, "cpufreq");
|
|
}
|
|
|
|
static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
|
|
{
|
|
struct freq_attr **drv_attr;
|
|
int ret = 0;
|
|
|
|
/* set up files for this cpu device */
|
|
drv_attr = cpufreq_driver->attr;
|
|
while (drv_attr && *drv_attr) {
|
|
ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
|
|
if (ret)
|
|
return ret;
|
|
drv_attr++;
|
|
}
|
|
if (cpufreq_driver->get) {
|
|
ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (cpufreq_driver->bios_limit) {
|
|
ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
__weak struct cpufreq_governor *cpufreq_default_governor(void)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static int cpufreq_init_policy(struct cpufreq_policy *policy)
|
|
{
|
|
struct cpufreq_governor *gov = NULL;
|
|
struct cpufreq_policy new_policy;
|
|
|
|
memcpy(&new_policy, policy, sizeof(*policy));
|
|
|
|
/* Update governor of new_policy to the governor used before hotplug */
|
|
gov = find_governor(policy->last_governor);
|
|
if (gov) {
|
|
pr_debug("Restoring governor %s for cpu %d\n",
|
|
policy->governor->name, policy->cpu);
|
|
} else {
|
|
gov = cpufreq_default_governor();
|
|
if (!gov)
|
|
return -ENODATA;
|
|
}
|
|
|
|
new_policy.governor = gov;
|
|
|
|
/* Use the default policy if there is no last_policy. */
|
|
if (cpufreq_driver->setpolicy) {
|
|
if (policy->last_policy)
|
|
new_policy.policy = policy->last_policy;
|
|
else
|
|
cpufreq_parse_governor(gov->name, &new_policy);
|
|
}
|
|
/* set default policy */
|
|
return cpufreq_set_policy(policy, &new_policy);
|
|
}
|
|
|
|
static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
|
|
{
|
|
int ret = 0;
|
|
|
|
/* Has this CPU been taken care of already? */
|
|
if (cpumask_test_cpu(cpu, policy->cpus))
|
|
return 0;
|
|
|
|
down_write(&policy->rwsem);
|
|
if (has_target())
|
|
cpufreq_stop_governor(policy);
|
|
|
|
cpumask_set_cpu(cpu, policy->cpus);
|
|
|
|
if (has_target()) {
|
|
ret = cpufreq_start_governor(policy);
|
|
if (ret)
|
|
pr_err("%s: Failed to start governor\n", __func__);
|
|
}
|
|
up_write(&policy->rwsem);
|
|
return ret;
|
|
}
|
|
|
|
static void handle_update(struct work_struct *work)
|
|
{
|
|
struct cpufreq_policy *policy =
|
|
container_of(work, struct cpufreq_policy, update);
|
|
unsigned int cpu = policy->cpu;
|
|
pr_debug("handle_update for cpu %u called\n", cpu);
|
|
cpufreq_update_policy(cpu);
|
|
}
|
|
|
|
static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy;
|
|
int ret;
|
|
|
|
policy = kzalloc(sizeof(*policy), GFP_KERNEL);
|
|
if (!policy)
|
|
return NULL;
|
|
|
|
if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
|
|
goto err_free_policy;
|
|
|
|
if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
|
|
goto err_free_cpumask;
|
|
|
|
if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
|
|
goto err_free_rcpumask;
|
|
|
|
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);
|
|
goto err_free_real_cpus;
|
|
}
|
|
|
|
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);
|
|
|
|
policy->cpu = cpu;
|
|
return policy;
|
|
|
|
err_free_real_cpus:
|
|
free_cpumask_var(policy->real_cpus);
|
|
err_free_rcpumask:
|
|
free_cpumask_var(policy->related_cpus);
|
|
err_free_cpumask:
|
|
free_cpumask_var(policy->cpus);
|
|
err_free_policy:
|
|
kfree(policy);
|
|
|
|
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)
|
|
{
|
|
unsigned long flags;
|
|
int cpu;
|
|
|
|
/* Remove policy from list */
|
|
write_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
list_del(&policy->policy_list);
|
|
|
|
for_each_cpu(cpu, policy->related_cpus)
|
|
per_cpu(cpufreq_cpu_data, cpu) = NULL;
|
|
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
cpufreq_policy_put_kobj(policy);
|
|
free_cpumask_var(policy->real_cpus);
|
|
free_cpumask_var(policy->related_cpus);
|
|
free_cpumask_var(policy->cpus);
|
|
kfree(policy);
|
|
}
|
|
|
|
static int cpufreq_online(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy;
|
|
bool new_policy;
|
|
unsigned long flags;
|
|
unsigned int j;
|
|
int ret;
|
|
|
|
pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
|
|
|
|
/* Check if this CPU already has a policy to manage it */
|
|
policy = per_cpu(cpufreq_cpu_data, cpu);
|
|
if (policy) {
|
|
WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
|
|
if (!policy_is_inactive(policy))
|
|
return cpufreq_add_policy_cpu(policy, cpu);
|
|
|
|
/* This is the only online CPU for the policy. Start over. */
|
|
new_policy = false;
|
|
down_write(&policy->rwsem);
|
|
policy->cpu = cpu;
|
|
policy->governor = NULL;
|
|
up_write(&policy->rwsem);
|
|
} else {
|
|
new_policy = true;
|
|
policy = cpufreq_policy_alloc(cpu);
|
|
if (!policy)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
cpumask_copy(policy->cpus, cpumask_of(cpu));
|
|
|
|
/* call driver. From then on the cpufreq must be able
|
|
* to accept all calls to ->verify and ->setpolicy for this CPU
|
|
*/
|
|
ret = cpufreq_driver->init(policy);
|
|
if (ret) {
|
|
pr_debug("initialization failed\n");
|
|
goto out_free_policy;
|
|
}
|
|
|
|
ret = cpufreq_table_validate_and_sort(policy);
|
|
if (ret)
|
|
goto out_exit_policy;
|
|
|
|
down_write(&policy->rwsem);
|
|
|
|
if (new_policy) {
|
|
/* related_cpus should at least include policy->cpus. */
|
|
cpumask_copy(policy->related_cpus, policy->cpus);
|
|
}
|
|
|
|
/*
|
|
* affected cpus must always be the one, which are online. We aren't
|
|
* managing offline cpus here.
|
|
*/
|
|
cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
|
|
|
|
if (new_policy) {
|
|
policy->user_policy.min = policy->min;
|
|
policy->user_policy.max = policy->max;
|
|
|
|
for_each_cpu(j, policy->related_cpus) {
|
|
per_cpu(cpufreq_cpu_data, j) = policy;
|
|
add_cpu_dev_symlink(policy, j);
|
|
}
|
|
} else {
|
|
policy->min = policy->user_policy.min;
|
|
policy->max = policy->user_policy.max;
|
|
}
|
|
|
|
if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
|
|
policy->cur = cpufreq_driver->get(policy->cpu);
|
|
if (!policy->cur) {
|
|
pr_err("%s: ->get() failed\n", __func__);
|
|
goto out_destroy_policy;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Sometimes boot loaders set CPU frequency to a value outside of
|
|
* frequency table present with cpufreq core. In such cases CPU might be
|
|
* unstable if it has to run on that frequency for long duration of time
|
|
* and so its better to set it to a frequency which is specified in
|
|
* freq-table. This also makes cpufreq stats inconsistent as
|
|
* cpufreq-stats would fail to register because current frequency of CPU
|
|
* isn't found in freq-table.
|
|
*
|
|
* Because we don't want this change to effect boot process badly, we go
|
|
* for the next freq which is >= policy->cur ('cur' must be set by now,
|
|
* otherwise we will end up setting freq to lowest of the table as 'cur'
|
|
* is initialized to zero).
|
|
*
|
|
* We are passing target-freq as "policy->cur - 1" otherwise
|
|
* __cpufreq_driver_target() would simply fail, as policy->cur will be
|
|
* equal to target-freq.
|
|
*/
|
|
if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
|
|
&& has_target()) {
|
|
/* Are we running at unknown frequency ? */
|
|
ret = cpufreq_frequency_table_get_index(policy, policy->cur);
|
|
if (ret == -EINVAL) {
|
|
/* Warn user and fix it */
|
|
pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
|
|
__func__, policy->cpu, policy->cur);
|
|
ret = __cpufreq_driver_target(policy, policy->cur - 1,
|
|
CPUFREQ_RELATION_L);
|
|
|
|
/*
|
|
* Reaching here after boot in a few seconds may not
|
|
* mean that system will remain stable at "unknown"
|
|
* frequency for longer duration. Hence, a BUG_ON().
|
|
*/
|
|
BUG_ON(ret);
|
|
pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
|
|
__func__, policy->cpu, policy->cur);
|
|
}
|
|
}
|
|
|
|
if (new_policy) {
|
|
ret = cpufreq_add_dev_interface(policy);
|
|
if (ret)
|
|
goto out_destroy_policy;
|
|
|
|
cpufreq_stats_create_table(policy);
|
|
|
|
write_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
list_add(&policy->policy_list, &cpufreq_policy_list);
|
|
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
}
|
|
|
|
ret = cpufreq_init_policy(policy);
|
|
if (ret) {
|
|
pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
|
|
__func__, cpu, ret);
|
|
/* cpufreq_policy_free() will notify based on this */
|
|
new_policy = false;
|
|
goto out_destroy_policy;
|
|
}
|
|
|
|
up_write(&policy->rwsem);
|
|
|
|
kobject_uevent(&policy->kobj, KOBJ_ADD);
|
|
|
|
/* Callback for handling stuff after policy is ready */
|
|
if (cpufreq_driver->ready)
|
|
cpufreq_driver->ready(policy);
|
|
|
|
pr_debug("initialization complete\n");
|
|
|
|
return 0;
|
|
|
|
out_destroy_policy:
|
|
for_each_cpu(j, policy->real_cpus)
|
|
remove_cpu_dev_symlink(policy, get_cpu_device(j));
|
|
|
|
up_write(&policy->rwsem);
|
|
|
|
out_exit_policy:
|
|
if (cpufreq_driver->exit)
|
|
cpufreq_driver->exit(policy);
|
|
|
|
out_free_policy:
|
|
cpufreq_policy_free(policy);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_add_dev - the cpufreq interface for a CPU device.
|
|
* @dev: CPU device.
|
|
* @sif: Subsystem interface structure pointer (not used)
|
|
*/
|
|
static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
|
|
{
|
|
struct cpufreq_policy *policy;
|
|
unsigned cpu = dev->id;
|
|
int ret;
|
|
|
|
dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
|
|
|
|
if (cpu_online(cpu)) {
|
|
ret = cpufreq_online(cpu);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
/* Create sysfs link on CPU registration */
|
|
policy = per_cpu(cpufreq_cpu_data, cpu);
|
|
if (policy)
|
|
add_cpu_dev_symlink(policy, cpu);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cpufreq_offline(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy;
|
|
int ret;
|
|
|
|
pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
|
|
|
|
policy = cpufreq_cpu_get_raw(cpu);
|
|
if (!policy) {
|
|
pr_debug("%s: No cpu_data found\n", __func__);
|
|
return 0;
|
|
}
|
|
|
|
down_write(&policy->rwsem);
|
|
if (has_target())
|
|
cpufreq_stop_governor(policy);
|
|
|
|
cpumask_clear_cpu(cpu, policy->cpus);
|
|
|
|
if (policy_is_inactive(policy)) {
|
|
if (has_target())
|
|
strncpy(policy->last_governor, policy->governor->name,
|
|
CPUFREQ_NAME_LEN);
|
|
else
|
|
policy->last_policy = policy->policy;
|
|
} else if (cpu == policy->cpu) {
|
|
/* Nominate new CPU */
|
|
policy->cpu = cpumask_any(policy->cpus);
|
|
}
|
|
|
|
/* Start governor again for active policy */
|
|
if (!policy_is_inactive(policy)) {
|
|
if (has_target()) {
|
|
ret = cpufreq_start_governor(policy);
|
|
if (ret)
|
|
pr_err("%s: Failed to start governor\n", __func__);
|
|
}
|
|
|
|
goto unlock;
|
|
}
|
|
|
|
if (cpufreq_driver->stop_cpu)
|
|
cpufreq_driver->stop_cpu(policy);
|
|
|
|
if (has_target())
|
|
cpufreq_exit_governor(policy);
|
|
|
|
/*
|
|
* Perform the ->exit() even during light-weight tear-down,
|
|
* since this is a core component, and is essential for the
|
|
* subsequent light-weight ->init() to succeed.
|
|
*/
|
|
if (cpufreq_driver->exit) {
|
|
cpufreq_driver->exit(policy);
|
|
policy->freq_table = NULL;
|
|
}
|
|
|
|
unlock:
|
|
up_write(&policy->rwsem);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_remove_dev - remove a CPU device
|
|
*
|
|
* Removes the cpufreq interface for a CPU device.
|
|
*/
|
|
static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
|
|
{
|
|
unsigned int cpu = dev->id;
|
|
struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
|
|
|
|
if (!policy)
|
|
return;
|
|
|
|
if (cpu_online(cpu))
|
|
cpufreq_offline(cpu);
|
|
|
|
cpumask_clear_cpu(cpu, policy->real_cpus);
|
|
remove_cpu_dev_symlink(policy, dev);
|
|
|
|
if (cpumask_empty(policy->real_cpus))
|
|
cpufreq_policy_free(policy);
|
|
}
|
|
|
|
/**
|
|
* cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
|
|
* in deep trouble.
|
|
* @policy: policy managing CPUs
|
|
* @new_freq: CPU frequency the CPU actually runs at
|
|
*
|
|
* We adjust to current frequency first, and need to clean up later.
|
|
* So either call to cpufreq_update_policy() or schedule handle_update()).
|
|
*/
|
|
static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
|
|
unsigned int new_freq)
|
|
{
|
|
struct cpufreq_freqs freqs;
|
|
|
|
pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
|
|
policy->cur, new_freq);
|
|
|
|
freqs.old = policy->cur;
|
|
freqs.new = new_freq;
|
|
|
|
cpufreq_freq_transition_begin(policy, &freqs);
|
|
cpufreq_freq_transition_end(policy, &freqs, 0);
|
|
}
|
|
|
|
/**
|
|
* cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
|
|
* @cpu: CPU number
|
|
*
|
|
* This is the last known freq, without actually getting it from the driver.
|
|
* Return value will be same as what is shown in scaling_cur_freq in sysfs.
|
|
*/
|
|
unsigned int cpufreq_quick_get(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy;
|
|
unsigned int ret_freq = 0;
|
|
unsigned long flags;
|
|
|
|
read_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
|
|
if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
|
|
ret_freq = cpufreq_driver->get(cpu);
|
|
read_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
return ret_freq;
|
|
}
|
|
|
|
read_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
policy = cpufreq_cpu_get(cpu);
|
|
if (policy) {
|
|
ret_freq = policy->cur;
|
|
cpufreq_cpu_put(policy);
|
|
}
|
|
|
|
return ret_freq;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_quick_get);
|
|
|
|
/**
|
|
* cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
|
|
* @cpu: CPU number
|
|
*
|
|
* Just return the max possible frequency for a given CPU.
|
|
*/
|
|
unsigned int cpufreq_quick_get_max(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
|
|
unsigned int ret_freq = 0;
|
|
|
|
if (policy) {
|
|
ret_freq = policy->max;
|
|
cpufreq_cpu_put(policy);
|
|
}
|
|
|
|
return ret_freq;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_quick_get_max);
|
|
|
|
static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
|
|
{
|
|
unsigned int ret_freq = 0;
|
|
|
|
if (!cpufreq_driver->get)
|
|
return ret_freq;
|
|
|
|
ret_freq = cpufreq_driver->get(policy->cpu);
|
|
|
|
/*
|
|
* Updating inactive policies is invalid, so avoid doing that. Also
|
|
* if fast frequency switching is used with the given policy, the check
|
|
* against policy->cur is pointless, so skip it in that case too.
|
|
*/
|
|
if (unlikely(policy_is_inactive(policy)) || policy->fast_switch_enabled)
|
|
return ret_freq;
|
|
|
|
if (ret_freq && policy->cur &&
|
|
!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
|
|
/* verify no discrepancy between actual and
|
|
saved value exists */
|
|
if (unlikely(ret_freq != policy->cur)) {
|
|
cpufreq_out_of_sync(policy, ret_freq);
|
|
schedule_work(&policy->update);
|
|
}
|
|
}
|
|
|
|
return ret_freq;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_get - get the current CPU frequency (in kHz)
|
|
* @cpu: CPU number
|
|
*
|
|
* Get the CPU current (static) CPU frequency
|
|
*/
|
|
unsigned int cpufreq_get(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
|
|
unsigned int ret_freq = 0;
|
|
|
|
if (policy) {
|
|
down_read(&policy->rwsem);
|
|
|
|
if (!policy_is_inactive(policy))
|
|
ret_freq = __cpufreq_get(policy);
|
|
|
|
up_read(&policy->rwsem);
|
|
|
|
cpufreq_cpu_put(policy);
|
|
}
|
|
|
|
return ret_freq;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_get);
|
|
|
|
static unsigned int cpufreq_update_current_freq(struct cpufreq_policy *policy)
|
|
{
|
|
unsigned int new_freq;
|
|
|
|
new_freq = cpufreq_driver->get(policy->cpu);
|
|
if (!new_freq)
|
|
return 0;
|
|
|
|
if (!policy->cur) {
|
|
pr_debug("cpufreq: Driver did not initialize current freq\n");
|
|
policy->cur = new_freq;
|
|
} else if (policy->cur != new_freq && has_target()) {
|
|
cpufreq_out_of_sync(policy, new_freq);
|
|
}
|
|
|
|
return new_freq;
|
|
}
|
|
|
|
static struct subsys_interface cpufreq_interface = {
|
|
.name = "cpufreq",
|
|
.subsys = &cpu_subsys,
|
|
.add_dev = cpufreq_add_dev,
|
|
.remove_dev = cpufreq_remove_dev,
|
|
};
|
|
|
|
/*
|
|
* In case platform wants some specific frequency to be configured
|
|
* during suspend..
|
|
*/
|
|
int cpufreq_generic_suspend(struct cpufreq_policy *policy)
|
|
{
|
|
int ret;
|
|
|
|
if (!policy->suspend_freq) {
|
|
pr_debug("%s: suspend_freq not defined\n", __func__);
|
|
return 0;
|
|
}
|
|
|
|
pr_debug("%s: Setting suspend-freq: %u\n", __func__,
|
|
policy->suspend_freq);
|
|
|
|
ret = __cpufreq_driver_target(policy, policy->suspend_freq,
|
|
CPUFREQ_RELATION_H);
|
|
if (ret)
|
|
pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
|
|
__func__, policy->suspend_freq, ret);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_generic_suspend);
|
|
|
|
/**
|
|
* cpufreq_suspend() - Suspend CPUFreq governors
|
|
*
|
|
* Called during system wide Suspend/Hibernate cycles for suspending governors
|
|
* as some platforms can't change frequency after this point in suspend cycle.
|
|
* Because some of the devices (like: i2c, regulators, etc) they use for
|
|
* changing frequency are suspended quickly after this point.
|
|
*/
|
|
void cpufreq_suspend(void)
|
|
{
|
|
struct cpufreq_policy *policy;
|
|
|
|
if (!cpufreq_driver)
|
|
return;
|
|
|
|
if (!has_target() && !cpufreq_driver->suspend)
|
|
goto suspend;
|
|
|
|
pr_debug("%s: Suspending Governors\n", __func__);
|
|
|
|
for_each_active_policy(policy) {
|
|
if (has_target()) {
|
|
down_write(&policy->rwsem);
|
|
cpufreq_stop_governor(policy);
|
|
up_write(&policy->rwsem);
|
|
}
|
|
|
|
if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
|
|
pr_err("%s: Failed to suspend driver: %p\n", __func__,
|
|
policy);
|
|
}
|
|
|
|
suspend:
|
|
cpufreq_suspended = true;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_resume() - Resume CPUFreq governors
|
|
*
|
|
* Called during system wide Suspend/Hibernate cycle for resuming governors that
|
|
* are suspended with cpufreq_suspend().
|
|
*/
|
|
void cpufreq_resume(void)
|
|
{
|
|
struct cpufreq_policy *policy;
|
|
int ret;
|
|
|
|
if (!cpufreq_driver)
|
|
return;
|
|
|
|
if (unlikely(!cpufreq_suspended))
|
|
return;
|
|
|
|
cpufreq_suspended = false;
|
|
|
|
if (!has_target() && !cpufreq_driver->resume)
|
|
return;
|
|
|
|
pr_debug("%s: Resuming Governors\n", __func__);
|
|
|
|
for_each_active_policy(policy) {
|
|
if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
|
|
pr_err("%s: Failed to resume driver: %p\n", __func__,
|
|
policy);
|
|
} else if (has_target()) {
|
|
down_write(&policy->rwsem);
|
|
ret = cpufreq_start_governor(policy);
|
|
up_write(&policy->rwsem);
|
|
|
|
if (ret)
|
|
pr_err("%s: Failed to start governor for policy: %p\n",
|
|
__func__, policy);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* cpufreq_get_current_driver - return current driver's name
|
|
*
|
|
* Return the name string of the currently loaded cpufreq driver
|
|
* or NULL, if none.
|
|
*/
|
|
const char *cpufreq_get_current_driver(void)
|
|
{
|
|
if (cpufreq_driver)
|
|
return cpufreq_driver->name;
|
|
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
|
|
|
|
/**
|
|
* cpufreq_get_driver_data - return current driver data
|
|
*
|
|
* Return the private data of the currently loaded cpufreq
|
|
* driver, or NULL if no cpufreq driver is loaded.
|
|
*/
|
|
void *cpufreq_get_driver_data(void)
|
|
{
|
|
if (cpufreq_driver)
|
|
return cpufreq_driver->driver_data;
|
|
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
|
|
|
|
/*********************************************************************
|
|
* NOTIFIER LISTS INTERFACE *
|
|
*********************************************************************/
|
|
|
|
/**
|
|
* cpufreq_register_notifier - register a driver with cpufreq
|
|
* @nb: notifier function to register
|
|
* @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
|
|
*
|
|
* Add a driver to one of two lists: either a list of drivers that
|
|
* are notified about clock rate changes (once before and once after
|
|
* the transition), or a list of drivers that are notified about
|
|
* changes in cpufreq policy.
|
|
*
|
|
* This function may sleep, and has the same return conditions as
|
|
* blocking_notifier_chain_register.
|
|
*/
|
|
int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
|
|
{
|
|
int ret;
|
|
|
|
if (cpufreq_disabled())
|
|
return -EINVAL;
|
|
|
|
switch (list) {
|
|
case CPUFREQ_TRANSITION_NOTIFIER:
|
|
mutex_lock(&cpufreq_fast_switch_lock);
|
|
|
|
if (cpufreq_fast_switch_count > 0) {
|
|
mutex_unlock(&cpufreq_fast_switch_lock);
|
|
return -EBUSY;
|
|
}
|
|
ret = srcu_notifier_chain_register(
|
|
&cpufreq_transition_notifier_list, nb);
|
|
if (!ret)
|
|
cpufreq_fast_switch_count--;
|
|
|
|
mutex_unlock(&cpufreq_fast_switch_lock);
|
|
break;
|
|
case CPUFREQ_POLICY_NOTIFIER:
|
|
ret = blocking_notifier_chain_register(
|
|
&cpufreq_policy_notifier_list, nb);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_register_notifier);
|
|
|
|
/**
|
|
* cpufreq_unregister_notifier - unregister a driver with cpufreq
|
|
* @nb: notifier block to be unregistered
|
|
* @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
|
|
*
|
|
* Remove a driver from the CPU frequency notifier list.
|
|
*
|
|
* This function may sleep, and has the same return conditions as
|
|
* blocking_notifier_chain_unregister.
|
|
*/
|
|
int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
|
|
{
|
|
int ret;
|
|
|
|
if (cpufreq_disabled())
|
|
return -EINVAL;
|
|
|
|
switch (list) {
|
|
case CPUFREQ_TRANSITION_NOTIFIER:
|
|
mutex_lock(&cpufreq_fast_switch_lock);
|
|
|
|
ret = srcu_notifier_chain_unregister(
|
|
&cpufreq_transition_notifier_list, nb);
|
|
if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
|
|
cpufreq_fast_switch_count++;
|
|
|
|
mutex_unlock(&cpufreq_fast_switch_lock);
|
|
break;
|
|
case CPUFREQ_POLICY_NOTIFIER:
|
|
ret = blocking_notifier_chain_unregister(
|
|
&cpufreq_policy_notifier_list, nb);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_unregister_notifier);
|
|
|
|
|
|
/*********************************************************************
|
|
* GOVERNORS *
|
|
*********************************************************************/
|
|
|
|
/**
|
|
* cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
|
|
* @policy: cpufreq policy to switch the frequency for.
|
|
* @target_freq: New frequency to set (may be approximate).
|
|
*
|
|
* Carry out a fast frequency switch without sleeping.
|
|
*
|
|
* The driver's ->fast_switch() callback invoked by this function must be
|
|
* suitable for being called from within RCU-sched read-side critical sections
|
|
* and it is expected to select the minimum available frequency greater than or
|
|
* equal to @target_freq (CPUFREQ_RELATION_L).
|
|
*
|
|
* This function must not be called if policy->fast_switch_enabled is unset.
|
|
*
|
|
* Governors calling this function must guarantee that it will never be invoked
|
|
* twice in parallel for the same policy and that it will never be called in
|
|
* parallel with either ->target() or ->target_index() for the same policy.
|
|
*
|
|
* Returns the actual frequency set for the CPU.
|
|
*
|
|
* If 0 is returned by the driver's ->fast_switch() callback to indicate an
|
|
* error condition, the hardware configuration must be preserved.
|
|
*/
|
|
unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
|
|
unsigned int target_freq)
|
|
{
|
|
target_freq = clamp_val(target_freq, policy->min, policy->max);
|
|
|
|
return cpufreq_driver->fast_switch(policy, target_freq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
|
|
|
|
/* Must set freqs->new to intermediate frequency */
|
|
static int __target_intermediate(struct cpufreq_policy *policy,
|
|
struct cpufreq_freqs *freqs, int index)
|
|
{
|
|
int ret;
|
|
|
|
freqs->new = cpufreq_driver->get_intermediate(policy, index);
|
|
|
|
/* We don't need to switch to intermediate freq */
|
|
if (!freqs->new)
|
|
return 0;
|
|
|
|
pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
|
|
__func__, policy->cpu, freqs->old, freqs->new);
|
|
|
|
cpufreq_freq_transition_begin(policy, freqs);
|
|
ret = cpufreq_driver->target_intermediate(policy, index);
|
|
cpufreq_freq_transition_end(policy, freqs, ret);
|
|
|
|
if (ret)
|
|
pr_err("%s: Failed to change to intermediate frequency: %d\n",
|
|
__func__, ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __target_index(struct cpufreq_policy *policy, int index)
|
|
{
|
|
struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
|
|
unsigned int intermediate_freq = 0;
|
|
unsigned int newfreq = policy->freq_table[index].frequency;
|
|
int retval = -EINVAL;
|
|
bool notify;
|
|
|
|
if (newfreq == policy->cur)
|
|
return 0;
|
|
|
|
notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
|
|
if (notify) {
|
|
/* Handle switching to intermediate frequency */
|
|
if (cpufreq_driver->get_intermediate) {
|
|
retval = __target_intermediate(policy, &freqs, index);
|
|
if (retval)
|
|
return retval;
|
|
|
|
intermediate_freq = freqs.new;
|
|
/* Set old freq to intermediate */
|
|
if (intermediate_freq)
|
|
freqs.old = freqs.new;
|
|
}
|
|
|
|
freqs.new = newfreq;
|
|
pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
|
|
__func__, policy->cpu, freqs.old, freqs.new);
|
|
|
|
cpufreq_freq_transition_begin(policy, &freqs);
|
|
}
|
|
|
|
retval = cpufreq_driver->target_index(policy, index);
|
|
if (retval)
|
|
pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
|
|
retval);
|
|
|
|
if (notify) {
|
|
cpufreq_freq_transition_end(policy, &freqs, retval);
|
|
|
|
/*
|
|
* Failed after setting to intermediate freq? Driver should have
|
|
* reverted back to initial frequency and so should we. Check
|
|
* here for intermediate_freq instead of get_intermediate, in
|
|
* case we haven't switched to intermediate freq at all.
|
|
*/
|
|
if (unlikely(retval && intermediate_freq)) {
|
|
freqs.old = intermediate_freq;
|
|
freqs.new = policy->restore_freq;
|
|
cpufreq_freq_transition_begin(policy, &freqs);
|
|
cpufreq_freq_transition_end(policy, &freqs, 0);
|
|
}
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
int __cpufreq_driver_target(struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
unsigned int old_target_freq = target_freq;
|
|
int index;
|
|
|
|
if (cpufreq_disabled())
|
|
return -ENODEV;
|
|
|
|
/* Make sure that target_freq is within supported range */
|
|
target_freq = clamp_val(target_freq, policy->min, policy->max);
|
|
|
|
pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
|
|
policy->cpu, target_freq, relation, old_target_freq);
|
|
|
|
/*
|
|
* This might look like a redundant call as we are checking it again
|
|
* after finding index. But it is left intentionally for cases where
|
|
* exactly same freq is called again and so we can save on few function
|
|
* calls.
|
|
*/
|
|
if (target_freq == policy->cur)
|
|
return 0;
|
|
|
|
/* Save last value to restore later on errors */
|
|
policy->restore_freq = policy->cur;
|
|
|
|
if (cpufreq_driver->target)
|
|
return cpufreq_driver->target(policy, target_freq, relation);
|
|
|
|
if (!cpufreq_driver->target_index)
|
|
return -EINVAL;
|
|
|
|
index = cpufreq_frequency_table_target(policy, target_freq, relation);
|
|
|
|
return __target_index(policy, index);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
|
|
|
|
int cpufreq_driver_target(struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
int ret = -EINVAL;
|
|
|
|
down_write(&policy->rwsem);
|
|
|
|
ret = __cpufreq_driver_target(policy, target_freq, relation);
|
|
|
|
up_write(&policy->rwsem);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_driver_target);
|
|
|
|
__weak struct cpufreq_governor *cpufreq_fallback_governor(void)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static int cpufreq_init_governor(struct cpufreq_policy *policy)
|
|
{
|
|
int ret;
|
|
|
|
/* Don't start any governor operations if we are entering suspend */
|
|
if (cpufreq_suspended)
|
|
return 0;
|
|
/*
|
|
* Governor might not be initiated here if ACPI _PPC changed
|
|
* notification happened, so check it.
|
|
*/
|
|
if (!policy->governor)
|
|
return -EINVAL;
|
|
|
|
/* Platform doesn't want dynamic frequency switching ? */
|
|
if (policy->governor->dynamic_switching &&
|
|
cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
|
|
struct cpufreq_governor *gov = cpufreq_fallback_governor();
|
|
|
|
if (gov) {
|
|
pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
|
|
policy->governor->name, gov->name);
|
|
policy->governor = gov;
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
if (!try_module_get(policy->governor->owner))
|
|
return -EINVAL;
|
|
|
|
pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
|
|
|
|
if (policy->governor->init) {
|
|
ret = policy->governor->init(policy);
|
|
if (ret) {
|
|
module_put(policy->governor->owner);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cpufreq_exit_governor(struct cpufreq_policy *policy)
|
|
{
|
|
if (cpufreq_suspended || !policy->governor)
|
|
return;
|
|
|
|
pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
|
|
|
|
if (policy->governor->exit)
|
|
policy->governor->exit(policy);
|
|
|
|
module_put(policy->governor->owner);
|
|
}
|
|
|
|
static int cpufreq_start_governor(struct cpufreq_policy *policy)
|
|
{
|
|
int ret;
|
|
|
|
if (cpufreq_suspended)
|
|
return 0;
|
|
|
|
if (!policy->governor)
|
|
return -EINVAL;
|
|
|
|
pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
|
|
|
|
if (cpufreq_driver->get && !cpufreq_driver->setpolicy)
|
|
cpufreq_update_current_freq(policy);
|
|
|
|
if (policy->governor->start) {
|
|
ret = policy->governor->start(policy);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
if (policy->governor->limits)
|
|
policy->governor->limits(policy);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cpufreq_stop_governor(struct cpufreq_policy *policy)
|
|
{
|
|
if (cpufreq_suspended || !policy->governor)
|
|
return;
|
|
|
|
pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
|
|
|
|
if (policy->governor->stop)
|
|
policy->governor->stop(policy);
|
|
}
|
|
|
|
static void cpufreq_governor_limits(struct cpufreq_policy *policy)
|
|
{
|
|
if (cpufreq_suspended || !policy->governor)
|
|
return;
|
|
|
|
pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
|
|
|
|
if (policy->governor->limits)
|
|
policy->governor->limits(policy);
|
|
}
|
|
|
|
int cpufreq_register_governor(struct cpufreq_governor *governor)
|
|
{
|
|
int err;
|
|
|
|
if (!governor)
|
|
return -EINVAL;
|
|
|
|
if (cpufreq_disabled())
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&cpufreq_governor_mutex);
|
|
|
|
err = -EBUSY;
|
|
if (!find_governor(governor->name)) {
|
|
err = 0;
|
|
list_add(&governor->governor_list, &cpufreq_governor_list);
|
|
}
|
|
|
|
mutex_unlock(&cpufreq_governor_mutex);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_register_governor);
|
|
|
|
void cpufreq_unregister_governor(struct cpufreq_governor *governor)
|
|
{
|
|
struct cpufreq_policy *policy;
|
|
unsigned long flags;
|
|
|
|
if (!governor)
|
|
return;
|
|
|
|
if (cpufreq_disabled())
|
|
return;
|
|
|
|
/* clear last_governor for all inactive policies */
|
|
read_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
for_each_inactive_policy(policy) {
|
|
if (!strcmp(policy->last_governor, governor->name)) {
|
|
policy->governor = NULL;
|
|
strcpy(policy->last_governor, "\0");
|
|
}
|
|
}
|
|
read_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
mutex_lock(&cpufreq_governor_mutex);
|
|
list_del(&governor->governor_list);
|
|
mutex_unlock(&cpufreq_governor_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
|
|
|
|
|
|
/*********************************************************************
|
|
* POLICY INTERFACE *
|
|
*********************************************************************/
|
|
|
|
/**
|
|
* cpufreq_get_policy - get the current cpufreq_policy
|
|
* @policy: struct cpufreq_policy into which the current cpufreq_policy
|
|
* is written
|
|
*
|
|
* Reads the current cpufreq policy.
|
|
*/
|
|
int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *cpu_policy;
|
|
if (!policy)
|
|
return -EINVAL;
|
|
|
|
cpu_policy = cpufreq_cpu_get(cpu);
|
|
if (!cpu_policy)
|
|
return -EINVAL;
|
|
|
|
memcpy(policy, cpu_policy, sizeof(*policy));
|
|
|
|
cpufreq_cpu_put(cpu_policy);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_get_policy);
|
|
|
|
/*
|
|
* policy : current policy.
|
|
* new_policy: policy to be set.
|
|
*/
|
|
static int cpufreq_set_policy(struct cpufreq_policy *policy,
|
|
struct cpufreq_policy *new_policy)
|
|
{
|
|
struct cpufreq_governor *old_gov;
|
|
int ret;
|
|
|
|
pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
|
|
new_policy->cpu, new_policy->min, new_policy->max);
|
|
|
|
memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
|
|
|
|
/*
|
|
* This check works well when we store new min/max freq attributes,
|
|
* because new_policy is a copy of policy with one field updated.
|
|
*/
|
|
if (new_policy->min > new_policy->max)
|
|
return -EINVAL;
|
|
|
|
/* verify the cpu speed can be set within this limit */
|
|
ret = cpufreq_driver->verify(new_policy);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* adjust if necessary - all reasons */
|
|
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
|
|
CPUFREQ_ADJUST, new_policy);
|
|
|
|
/*
|
|
* verify the cpu speed can be set within this limit, which might be
|
|
* different to the first one
|
|
*/
|
|
ret = cpufreq_driver->verify(new_policy);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* notification of the new policy */
|
|
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
|
|
CPUFREQ_NOTIFY, new_policy);
|
|
|
|
policy->min = new_policy->min;
|
|
policy->max = new_policy->max;
|
|
trace_cpu_frequency_limits(policy);
|
|
|
|
policy->cached_target_freq = UINT_MAX;
|
|
|
|
pr_debug("new min and max freqs are %u - %u kHz\n",
|
|
policy->min, policy->max);
|
|
|
|
if (cpufreq_driver->setpolicy) {
|
|
policy->policy = new_policy->policy;
|
|
pr_debug("setting range\n");
|
|
return cpufreq_driver->setpolicy(new_policy);
|
|
}
|
|
|
|
if (new_policy->governor == policy->governor) {
|
|
pr_debug("cpufreq: governor limits update\n");
|
|
cpufreq_governor_limits(policy);
|
|
return 0;
|
|
}
|
|
|
|
pr_debug("governor switch\n");
|
|
|
|
/* save old, working values */
|
|
old_gov = policy->governor;
|
|
/* end old governor */
|
|
if (old_gov) {
|
|
cpufreq_stop_governor(policy);
|
|
cpufreq_exit_governor(policy);
|
|
}
|
|
|
|
/* start new governor */
|
|
policy->governor = new_policy->governor;
|
|
ret = cpufreq_init_governor(policy);
|
|
if (!ret) {
|
|
ret = cpufreq_start_governor(policy);
|
|
if (!ret) {
|
|
pr_debug("cpufreq: governor change\n");
|
|
return 0;
|
|
}
|
|
cpufreq_exit_governor(policy);
|
|
}
|
|
|
|
/* new governor failed, so re-start old one */
|
|
pr_debug("starting governor %s failed\n", policy->governor->name);
|
|
if (old_gov) {
|
|
policy->governor = old_gov;
|
|
if (cpufreq_init_governor(policy))
|
|
policy->governor = NULL;
|
|
else
|
|
cpufreq_start_governor(policy);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_update_policy - re-evaluate an existing cpufreq policy
|
|
* @cpu: CPU which shall be re-evaluated
|
|
*
|
|
* Useful for policy notifiers which have different necessities
|
|
* at different times.
|
|
*/
|
|
void cpufreq_update_policy(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
|
|
struct cpufreq_policy new_policy;
|
|
|
|
if (!policy)
|
|
return;
|
|
|
|
down_write(&policy->rwsem);
|
|
|
|
if (policy_is_inactive(policy))
|
|
goto unlock;
|
|
|
|
pr_debug("updating policy for CPU %u\n", cpu);
|
|
memcpy(&new_policy, policy, sizeof(*policy));
|
|
new_policy.min = policy->user_policy.min;
|
|
new_policy.max = policy->user_policy.max;
|
|
|
|
/*
|
|
* BIOS might change freq behind our back
|
|
* -> ask driver for current freq and notify governors about a change
|
|
*/
|
|
if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
|
|
if (cpufreq_suspended)
|
|
goto unlock;
|
|
|
|
new_policy.cur = cpufreq_update_current_freq(policy);
|
|
if (WARN_ON(!new_policy.cur))
|
|
goto unlock;
|
|
}
|
|
|
|
cpufreq_set_policy(policy, &new_policy);
|
|
|
|
unlock:
|
|
up_write(&policy->rwsem);
|
|
|
|
cpufreq_cpu_put(policy);
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_update_policy);
|
|
|
|
/*********************************************************************
|
|
* BOOST *
|
|
*********************************************************************/
|
|
static int cpufreq_boost_set_sw(int state)
|
|
{
|
|
struct cpufreq_policy *policy;
|
|
int ret = -EINVAL;
|
|
|
|
for_each_active_policy(policy) {
|
|
if (!policy->freq_table)
|
|
continue;
|
|
|
|
ret = cpufreq_frequency_table_cpuinfo(policy,
|
|
policy->freq_table);
|
|
if (ret) {
|
|
pr_err("%s: Policy frequency update failed\n",
|
|
__func__);
|
|
break;
|
|
}
|
|
|
|
down_write(&policy->rwsem);
|
|
policy->user_policy.max = policy->max;
|
|
cpufreq_governor_limits(policy);
|
|
up_write(&policy->rwsem);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int cpufreq_boost_trigger_state(int state)
|
|
{
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
|
|
if (cpufreq_driver->boost_enabled == state)
|
|
return 0;
|
|
|
|
write_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
cpufreq_driver->boost_enabled = state;
|
|
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
ret = cpufreq_driver->set_boost(state);
|
|
if (ret) {
|
|
write_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
cpufreq_driver->boost_enabled = !state;
|
|
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
pr_err("%s: Cannot %s BOOST\n",
|
|
__func__, state ? "enable" : "disable");
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool cpufreq_boost_supported(void)
|
|
{
|
|
return likely(cpufreq_driver) && cpufreq_driver->set_boost;
|
|
}
|
|
|
|
static int create_boost_sysfs_file(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
|
|
if (ret)
|
|
pr_err("%s: cannot register global BOOST sysfs file\n",
|
|
__func__);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void remove_boost_sysfs_file(void)
|
|
{
|
|
if (cpufreq_boost_supported())
|
|
sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
|
|
}
|
|
|
|
int cpufreq_enable_boost_support(void)
|
|
{
|
|
if (!cpufreq_driver)
|
|
return -EINVAL;
|
|
|
|
if (cpufreq_boost_supported())
|
|
return 0;
|
|
|
|
cpufreq_driver->set_boost = cpufreq_boost_set_sw;
|
|
|
|
/* This will get removed on driver unregister */
|
|
return create_boost_sysfs_file();
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
|
|
|
|
int cpufreq_boost_enabled(void)
|
|
{
|
|
return cpufreq_driver->boost_enabled;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
|
|
|
|
/*********************************************************************
|
|
* REGISTER / UNREGISTER CPUFREQ DRIVER *
|
|
*********************************************************************/
|
|
static enum cpuhp_state hp_online;
|
|
|
|
static int cpuhp_cpufreq_online(unsigned int cpu)
|
|
{
|
|
cpufreq_online(cpu);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cpuhp_cpufreq_offline(unsigned int cpu)
|
|
{
|
|
cpufreq_offline(cpu);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_register_driver - register a CPU Frequency driver
|
|
* @driver_data: A struct cpufreq_driver containing the values#
|
|
* submitted by the CPU Frequency driver.
|
|
*
|
|
* Registers a CPU Frequency driver to this core code. This code
|
|
* returns zero on success, -EEXIST when another driver got here first
|
|
* (and isn't unregistered in the meantime).
|
|
*
|
|
*/
|
|
int cpufreq_register_driver(struct cpufreq_driver *driver_data)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
if (cpufreq_disabled())
|
|
return -ENODEV;
|
|
|
|
if (!driver_data || !driver_data->verify || !driver_data->init ||
|
|
!(driver_data->setpolicy || driver_data->target_index ||
|
|
driver_data->target) ||
|
|
(driver_data->setpolicy && (driver_data->target_index ||
|
|
driver_data->target)) ||
|
|
(!!driver_data->get_intermediate != !!driver_data->target_intermediate))
|
|
return -EINVAL;
|
|
|
|
pr_debug("trying to register driver %s\n", driver_data->name);
|
|
|
|
/* Protect against concurrent CPU online/offline. */
|
|
cpus_read_lock();
|
|
|
|
write_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
if (cpufreq_driver) {
|
|
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
ret = -EEXIST;
|
|
goto out;
|
|
}
|
|
cpufreq_driver = driver_data;
|
|
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
if (driver_data->setpolicy)
|
|
driver_data->flags |= CPUFREQ_CONST_LOOPS;
|
|
|
|
if (cpufreq_boost_supported()) {
|
|
ret = create_boost_sysfs_file();
|
|
if (ret)
|
|
goto err_null_driver;
|
|
}
|
|
|
|
ret = subsys_interface_register(&cpufreq_interface);
|
|
if (ret)
|
|
goto err_boost_unreg;
|
|
|
|
if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
|
|
list_empty(&cpufreq_policy_list)) {
|
|
/* if all ->init() calls failed, unregister */
|
|
ret = -ENODEV;
|
|
pr_debug("%s: No CPU initialized for driver %s\n", __func__,
|
|
driver_data->name);
|
|
goto err_if_unreg;
|
|
}
|
|
|
|
ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
|
|
"cpufreq:online",
|
|
cpuhp_cpufreq_online,
|
|
cpuhp_cpufreq_offline);
|
|
if (ret < 0)
|
|
goto err_if_unreg;
|
|
hp_online = ret;
|
|
ret = 0;
|
|
|
|
pr_debug("driver %s up and running\n", driver_data->name);
|
|
goto out;
|
|
|
|
err_if_unreg:
|
|
subsys_interface_unregister(&cpufreq_interface);
|
|
err_boost_unreg:
|
|
remove_boost_sysfs_file();
|
|
err_null_driver:
|
|
write_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
cpufreq_driver = NULL;
|
|
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
out:
|
|
cpus_read_unlock();
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_register_driver);
|
|
|
|
/**
|
|
* cpufreq_unregister_driver - unregister the current CPUFreq driver
|
|
*
|
|
* Unregister the current CPUFreq driver. Only call this if you have
|
|
* the right to do so, i.e. if you have succeeded in initialising before!
|
|
* Returns zero if successful, and -EINVAL if the cpufreq_driver is
|
|
* currently not initialised.
|
|
*/
|
|
int cpufreq_unregister_driver(struct cpufreq_driver *driver)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (!cpufreq_driver || (driver != cpufreq_driver))
|
|
return -EINVAL;
|
|
|
|
pr_debug("unregistering driver %s\n", driver->name);
|
|
|
|
/* Protect against concurrent cpu hotplug */
|
|
cpus_read_lock();
|
|
subsys_interface_unregister(&cpufreq_interface);
|
|
remove_boost_sysfs_file();
|
|
cpuhp_remove_state_nocalls_cpuslocked(hp_online);
|
|
|
|
write_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
|
|
cpufreq_driver = NULL;
|
|
|
|
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
cpus_read_unlock();
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
|
|
|
|
/*
|
|
* Stop cpufreq at shutdown to make sure it isn't holding any locks
|
|
* or mutexes when secondary CPUs are halted.
|
|
*/
|
|
static struct syscore_ops cpufreq_syscore_ops = {
|
|
.shutdown = cpufreq_suspend,
|
|
};
|
|
|
|
struct kobject *cpufreq_global_kobject;
|
|
EXPORT_SYMBOL(cpufreq_global_kobject);
|
|
|
|
static int __init cpufreq_core_init(void)
|
|
{
|
|
if (cpufreq_disabled())
|
|
return -ENODEV;
|
|
|
|
cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
|
|
BUG_ON(!cpufreq_global_kobject);
|
|
|
|
register_syscore_ops(&cpufreq_syscore_ops);
|
|
|
|
return 0;
|
|
}
|
|
module_param(off, int, 0444);
|
|
core_initcall(cpufreq_core_init);
|