mirror of https://gitee.com/openkylin/linux.git
1959 lines
49 KiB
C
1959 lines
49 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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*
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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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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/notifier.h>
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#include <linux/cpufreq.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/spinlock.h>
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#include <linux/device.h>
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#include <linux/slab.h>
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#include <linux/cpu.h>
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#include <linux/completion.h>
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#include <linux/mutex.h>
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#include <linux/syscore_ops.h>
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#include <trace/events/power.h>
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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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#ifdef CONFIG_HOTPLUG_CPU
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/* This one keeps track of the previously set governor of a removed CPU */
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static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
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#endif
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static DEFINE_SPINLOCK(cpufreq_driver_lock);
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/*
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* cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure
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* all cpufreq/hotplug/workqueue/etc related lock issues.
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*
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* The rules for this semaphore:
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* - Any routine that wants to read from the policy structure will
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* do a down_read on this semaphore.
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* - Any routine that will write to the policy structure and/or may take away
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* the policy altogether (eg. CPU hotplug), will hold this lock in write
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* mode before doing so.
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*
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* Additional rules:
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* - All holders of the lock should check to make sure that the CPU they
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* are concerned with are online after they get the lock.
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* - Governor routines that can be called in cpufreq hotplug path should not
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* take this sem as top level hotplug notifier handler takes this.
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* - Lock should not be held across
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* __cpufreq_governor(data, CPUFREQ_GOV_STOP);
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*/
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static DEFINE_PER_CPU(int, cpufreq_policy_cpu);
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static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem);
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#define lock_policy_rwsem(mode, cpu) \
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static int lock_policy_rwsem_##mode \
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(int cpu) \
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{ \
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int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \
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BUG_ON(policy_cpu == -1); \
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down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
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if (unlikely(!cpu_online(cpu))) { \
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up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
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return -1; \
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} \
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\
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return 0; \
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}
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lock_policy_rwsem(read, cpu);
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lock_policy_rwsem(write, cpu);
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static void unlock_policy_rwsem_read(int cpu)
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{
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int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);
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BUG_ON(policy_cpu == -1);
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up_read(&per_cpu(cpu_policy_rwsem, policy_cpu));
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}
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static void unlock_policy_rwsem_write(int cpu)
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{
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int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);
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BUG_ON(policy_cpu == -1);
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up_write(&per_cpu(cpu_policy_rwsem, policy_cpu));
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}
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/* internal prototypes */
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static int __cpufreq_governor(struct cpufreq_policy *policy,
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unsigned int event);
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static unsigned int __cpufreq_get(unsigned int cpu);
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static void handle_update(struct work_struct *work);
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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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static struct srcu_notifier_head cpufreq_transition_notifier_list;
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static bool init_cpufreq_transition_notifier_list_called;
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static int __init init_cpufreq_transition_notifier_list(void)
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{
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srcu_init_notifier_head(&cpufreq_transition_notifier_list);
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init_cpufreq_transition_notifier_list_called = true;
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return 0;
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}
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pure_initcall(init_cpufreq_transition_notifier_list);
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static int off __read_mostly;
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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 LIST_HEAD(cpufreq_governor_list);
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static DEFINE_MUTEX(cpufreq_governor_mutex);
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static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs)
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{
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struct cpufreq_policy *data;
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unsigned long flags;
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if (cpu >= nr_cpu_ids)
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goto err_out;
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/* get the cpufreq driver */
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spin_lock_irqsave(&cpufreq_driver_lock, flags);
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if (!cpufreq_driver)
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goto err_out_unlock;
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if (!try_module_get(cpufreq_driver->owner))
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goto err_out_unlock;
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/* get the CPU */
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data = per_cpu(cpufreq_cpu_data, cpu);
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if (!data)
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goto err_out_put_module;
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if (!sysfs && !kobject_get(&data->kobj))
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goto err_out_put_module;
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spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
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return data;
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err_out_put_module:
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module_put(cpufreq_driver->owner);
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err_out_unlock:
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spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
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err_out:
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return NULL;
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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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return __cpufreq_cpu_get(cpu, false);
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}
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EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
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static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu)
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{
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return __cpufreq_cpu_get(cpu, true);
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}
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static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs)
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{
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if (!sysfs)
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kobject_put(&data->kobj);
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module_put(cpufreq_driver->owner);
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}
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void cpufreq_cpu_put(struct cpufreq_policy *data)
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{
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__cpufreq_cpu_put(data, false);
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}
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EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
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static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data)
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{
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__cpufreq_cpu_put(data, true);
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}
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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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#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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static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
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{
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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; "
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"freq is %u kHz\n", 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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(val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) {
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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 "
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"for frequency %u kHz\n", loops_per_jiffy, ci->new);
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}
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}
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#else
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static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
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{
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return;
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}
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#endif
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/**
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* cpufreq_notify_transition - call notifier chain and adjust_jiffies
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* on frequency transition.
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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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void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
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{
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struct cpufreq_policy *policy;
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BUG_ON(irqs_disabled());
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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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policy = per_cpu(cpufreq_cpu_data, freqs->cpu);
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switch (state) {
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case CPUFREQ_PRECHANGE:
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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) && (policy->cpu == freqs->cpu) &&
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(policy->cur) && (policy->cur != freqs->old)) {
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pr_debug("Warning: CPU frequency is"
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" %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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srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
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CPUFREQ_PRECHANGE, freqs);
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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: %lu - CPU: %lu", (unsigned long)freqs->new,
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(unsigned long)freqs->cpu);
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trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu);
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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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if (likely(policy) && likely(policy->cpu == freqs->cpu))
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policy->cur = freqs->new;
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break;
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}
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}
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EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
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/*********************************************************************
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* SYSFS INTERFACE *
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*********************************************************************/
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static struct cpufreq_governor *__find_governor(const char *str_governor)
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{
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struct cpufreq_governor *t;
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list_for_each_entry(t, &cpufreq_governor_list, governor_list)
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if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN))
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return t;
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return NULL;
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}
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/**
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* cpufreq_parse_governor - parse a governor string
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*/
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static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
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struct cpufreq_governor **governor)
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{
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int err = -EINVAL;
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if (!cpufreq_driver)
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goto out;
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if (cpufreq_driver->setpolicy) {
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if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
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*policy = CPUFREQ_POLICY_PERFORMANCE;
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err = 0;
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} else if (!strnicmp(str_governor, "powersave",
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CPUFREQ_NAME_LEN)) {
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*policy = CPUFREQ_POLICY_POWERSAVE;
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err = 0;
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}
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} else if (cpufreq_driver->target) {
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struct cpufreq_governor *t;
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mutex_lock(&cpufreq_governor_mutex);
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t = __find_governor(str_governor);
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if (t == NULL) {
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int ret;
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mutex_unlock(&cpufreq_governor_mutex);
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ret = request_module("cpufreq_%s", str_governor);
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mutex_lock(&cpufreq_governor_mutex);
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if (ret == 0)
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t = __find_governor(str_governor);
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}
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if (t != NULL) {
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*governor = t;
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err = 0;
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}
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mutex_unlock(&cpufreq_governor_mutex);
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}
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out:
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return err;
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}
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/**
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* cpufreq_per_cpu_attr_read() / show_##file_name() -
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* print out cpufreq information
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*
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* Write out information from cpufreq_driver->policy[cpu]; object must be
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* "unsigned int".
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*/
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#define show_one(file_name, object) \
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static ssize_t show_##file_name \
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(struct cpufreq_policy *policy, char *buf) \
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{ \
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return sprintf(buf, "%u\n", policy->object); \
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}
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show_one(cpuinfo_min_freq, cpuinfo.min_freq);
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show_one(cpuinfo_max_freq, cpuinfo.max_freq);
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show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
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show_one(scaling_min_freq, min);
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show_one(scaling_max_freq, max);
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show_one(scaling_cur_freq, cur);
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static int __cpufreq_set_policy(struct cpufreq_policy *data,
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struct cpufreq_policy *policy);
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/**
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* cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
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*/
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#define store_one(file_name, object) \
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static ssize_t store_##file_name \
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(struct cpufreq_policy *policy, const char *buf, size_t count) \
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{ \
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unsigned int ret = -EINVAL; \
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struct cpufreq_policy new_policy; \
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\
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ret = cpufreq_get_policy(&new_policy, policy->cpu); \
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if (ret) \
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return -EINVAL; \
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\
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ret = sscanf(buf, "%u", &new_policy.object); \
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if (ret != 1) \
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return -EINVAL; \
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\
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ret = __cpufreq_set_policy(policy, &new_policy); \
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policy->user_policy.object = policy->object; \
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\
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return ret ? ret : count; \
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}
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store_one(scaling_min_freq, min);
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store_one(scaling_max_freq, max);
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/**
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* show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
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*/
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static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
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char *buf)
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{
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unsigned int cur_freq = __cpufreq_get(policy->cpu);
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if (!cur_freq)
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return sprintf(buf, "<unknown>");
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return sprintf(buf, "%u\n", cur_freq);
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}
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/**
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* show_scaling_governor - show the current policy for the specified CPU
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*/
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static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
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{
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if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
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return sprintf(buf, "powersave\n");
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else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
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return sprintf(buf, "performance\n");
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else if (policy->governor)
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return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n",
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policy->governor->name);
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return -EINVAL;
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}
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/**
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* store_scaling_governor - store policy for the specified CPU
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*/
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static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
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const char *buf, size_t count)
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{
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unsigned int ret = -EINVAL;
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char str_governor[16];
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struct cpufreq_policy new_policy;
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ret = cpufreq_get_policy(&new_policy, policy->cpu);
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if (ret)
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return ret;
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ret = sscanf(buf, "%15s", str_governor);
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if (ret != 1)
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return -EINVAL;
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if (cpufreq_parse_governor(str_governor, &new_policy.policy,
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&new_policy.governor))
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return -EINVAL;
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/* Do not use cpufreq_set_policy here or the user_policy.max
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will be wrongly overridden */
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ret = __cpufreq_set_policy(policy, &new_policy);
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policy->user_policy.policy = policy->policy;
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policy->user_policy.governor = policy->governor;
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if (ret)
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return ret;
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else
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return count;
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}
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/**
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* show_scaling_driver - show the cpufreq driver currently loaded
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*/
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static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
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{
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return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
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}
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/**
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* show_scaling_available_governors - show the available CPUfreq governors
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*/
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static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
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char *buf)
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{
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ssize_t i = 0;
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struct cpufreq_governor *t;
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if (!cpufreq_driver->target) {
|
|
i += sprintf(buf, "performance powersave");
|
|
goto out;
|
|
}
|
|
|
|
list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
|
|
if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
|
|
- (CPUFREQ_NAME_LEN + 2)))
|
|
goto out;
|
|
i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
|
|
}
|
|
out:
|
|
i += sprintf(&buf[i], "\n");
|
|
return i;
|
|
}
|
|
|
|
static ssize_t 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;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
if (cpumask_empty(policy->related_cpus))
|
|
return show_cpus(policy->cpus, buf);
|
|
return 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 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_scaling_driver - 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
|
|
};
|
|
|
|
struct kobject *cpufreq_global_kobject;
|
|
EXPORT_SYMBOL(cpufreq_global_kobject);
|
|
|
|
#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 = -EINVAL;
|
|
policy = cpufreq_cpu_get_sysfs(policy->cpu);
|
|
if (!policy)
|
|
goto no_policy;
|
|
|
|
if (lock_policy_rwsem_read(policy->cpu) < 0)
|
|
goto fail;
|
|
|
|
if (fattr->show)
|
|
ret = fattr->show(policy, buf);
|
|
else
|
|
ret = -EIO;
|
|
|
|
unlock_policy_rwsem_read(policy->cpu);
|
|
fail:
|
|
cpufreq_cpu_put_sysfs(policy);
|
|
no_policy:
|
|
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;
|
|
policy = cpufreq_cpu_get_sysfs(policy->cpu);
|
|
if (!policy)
|
|
goto no_policy;
|
|
|
|
if (lock_policy_rwsem_write(policy->cpu) < 0)
|
|
goto fail;
|
|
|
|
if (fattr->store)
|
|
ret = fattr->store(policy, buf, count);
|
|
else
|
|
ret = -EIO;
|
|
|
|
unlock_policy_rwsem_write(policy->cpu);
|
|
fail:
|
|
cpufreq_cpu_put_sysfs(policy);
|
|
no_policy:
|
|
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,
|
|
};
|
|
|
|
/*
|
|
* Returns:
|
|
* Negative: Failure
|
|
* 0: Success
|
|
* Positive: When we have a managed CPU and the sysfs got symlinked
|
|
*/
|
|
static int cpufreq_add_dev_policy(unsigned int cpu,
|
|
struct cpufreq_policy *policy,
|
|
struct device *dev)
|
|
{
|
|
int ret = 0;
|
|
#ifdef CONFIG_SMP
|
|
unsigned long flags;
|
|
unsigned int j;
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
struct cpufreq_governor *gov;
|
|
|
|
gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));
|
|
if (gov) {
|
|
policy->governor = gov;
|
|
pr_debug("Restoring governor %s for cpu %d\n",
|
|
policy->governor->name, cpu);
|
|
}
|
|
#endif
|
|
|
|
for_each_cpu(j, policy->cpus) {
|
|
struct cpufreq_policy *managed_policy;
|
|
|
|
if (cpu == j)
|
|
continue;
|
|
|
|
/* Check for existing affected CPUs.
|
|
* They may not be aware of it due to CPU Hotplug.
|
|
* cpufreq_cpu_put is called when the device is removed
|
|
* in __cpufreq_remove_dev()
|
|
*/
|
|
managed_policy = cpufreq_cpu_get(j);
|
|
if (unlikely(managed_policy)) {
|
|
|
|
/* Set proper policy_cpu */
|
|
unlock_policy_rwsem_write(cpu);
|
|
per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu;
|
|
|
|
if (lock_policy_rwsem_write(cpu) < 0) {
|
|
/* Should not go through policy unlock path */
|
|
if (cpufreq_driver->exit)
|
|
cpufreq_driver->exit(policy);
|
|
cpufreq_cpu_put(managed_policy);
|
|
return -EBUSY;
|
|
}
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
cpumask_copy(managed_policy->cpus, policy->cpus);
|
|
per_cpu(cpufreq_cpu_data, cpu) = managed_policy;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
pr_debug("CPU already managed, adding link\n");
|
|
ret = sysfs_create_link(&dev->kobj,
|
|
&managed_policy->kobj,
|
|
"cpufreq");
|
|
if (ret)
|
|
cpufreq_cpu_put(managed_policy);
|
|
/*
|
|
* Success. We only needed to be added to the mask.
|
|
* Call driver->exit() because only the cpu parent of
|
|
* the kobj needed to call init().
|
|
*/
|
|
if (cpufreq_driver->exit)
|
|
cpufreq_driver->exit(policy);
|
|
|
|
if (!ret)
|
|
return 1;
|
|
else
|
|
return ret;
|
|
}
|
|
}
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
|
|
/* symlink affected CPUs */
|
|
static int cpufreq_add_dev_symlink(unsigned int cpu,
|
|
struct cpufreq_policy *policy)
|
|
{
|
|
unsigned int j;
|
|
int ret = 0;
|
|
|
|
for_each_cpu(j, policy->cpus) {
|
|
struct cpufreq_policy *managed_policy;
|
|
struct device *cpu_dev;
|
|
|
|
if (j == cpu)
|
|
continue;
|
|
if (!cpu_online(j))
|
|
continue;
|
|
|
|
pr_debug("CPU %u already managed, adding link\n", j);
|
|
managed_policy = cpufreq_cpu_get(cpu);
|
|
cpu_dev = get_cpu_device(j);
|
|
ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
|
|
"cpufreq");
|
|
if (ret) {
|
|
cpufreq_cpu_put(managed_policy);
|
|
return ret;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int cpufreq_add_dev_interface(unsigned int cpu,
|
|
struct cpufreq_policy *policy,
|
|
struct device *dev)
|
|
{
|
|
struct cpufreq_policy new_policy;
|
|
struct freq_attr **drv_attr;
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
unsigned int j;
|
|
|
|
/* prepare interface data */
|
|
ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
|
|
&dev->kobj, "cpufreq");
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* 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)
|
|
goto err_out_kobj_put;
|
|
drv_attr++;
|
|
}
|
|
if (cpufreq_driver->get) {
|
|
ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
|
|
if (ret)
|
|
goto err_out_kobj_put;
|
|
}
|
|
if (cpufreq_driver->target) {
|
|
ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
|
|
if (ret)
|
|
goto err_out_kobj_put;
|
|
}
|
|
if (cpufreq_driver->bios_limit) {
|
|
ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
|
|
if (ret)
|
|
goto err_out_kobj_put;
|
|
}
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
for_each_cpu(j, policy->cpus) {
|
|
if (!cpu_online(j))
|
|
continue;
|
|
per_cpu(cpufreq_cpu_data, j) = policy;
|
|
per_cpu(cpufreq_policy_cpu, j) = policy->cpu;
|
|
}
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
ret = cpufreq_add_dev_symlink(cpu, policy);
|
|
if (ret)
|
|
goto err_out_kobj_put;
|
|
|
|
memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
|
|
/* assure that the starting sequence is run in __cpufreq_set_policy */
|
|
policy->governor = NULL;
|
|
|
|
/* set default policy */
|
|
ret = __cpufreq_set_policy(policy, &new_policy);
|
|
policy->user_policy.policy = policy->policy;
|
|
policy->user_policy.governor = policy->governor;
|
|
|
|
if (ret) {
|
|
pr_debug("setting policy failed\n");
|
|
if (cpufreq_driver->exit)
|
|
cpufreq_driver->exit(policy);
|
|
}
|
|
return ret;
|
|
|
|
err_out_kobj_put:
|
|
kobject_put(&policy->kobj);
|
|
wait_for_completion(&policy->kobj_unregister);
|
|
return ret;
|
|
}
|
|
|
|
|
|
/**
|
|
* cpufreq_add_dev - add a CPU device
|
|
*
|
|
* Adds the cpufreq interface for a CPU device.
|
|
*
|
|
* The Oracle says: try running cpufreq registration/unregistration concurrently
|
|
* with with cpu hotplugging and all hell will break loose. Tried to clean this
|
|
* mess up, but more thorough testing is needed. - Mathieu
|
|
*/
|
|
static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
|
|
{
|
|
unsigned int cpu = dev->id;
|
|
int ret = 0, found = 0;
|
|
struct cpufreq_policy *policy;
|
|
unsigned long flags;
|
|
unsigned int j;
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
int sibling;
|
|
#endif
|
|
|
|
if (cpu_is_offline(cpu))
|
|
return 0;
|
|
|
|
pr_debug("adding CPU %u\n", cpu);
|
|
|
|
#ifdef CONFIG_SMP
|
|
/* check whether a different CPU already registered this
|
|
* CPU because it is in the same boat. */
|
|
policy = cpufreq_cpu_get(cpu);
|
|
if (unlikely(policy)) {
|
|
cpufreq_cpu_put(policy);
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
if (!try_module_get(cpufreq_driver->owner)) {
|
|
ret = -EINVAL;
|
|
goto module_out;
|
|
}
|
|
|
|
ret = -ENOMEM;
|
|
policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
|
|
if (!policy)
|
|
goto nomem_out;
|
|
|
|
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;
|
|
|
|
policy->cpu = cpu;
|
|
cpumask_copy(policy->cpus, cpumask_of(cpu));
|
|
|
|
/* Initially set CPU itself as the policy_cpu */
|
|
per_cpu(cpufreq_policy_cpu, cpu) = cpu;
|
|
ret = (lock_policy_rwsem_write(cpu) < 0);
|
|
WARN_ON(ret);
|
|
|
|
init_completion(&policy->kobj_unregister);
|
|
INIT_WORK(&policy->update, handle_update);
|
|
|
|
/* Set governor before ->init, so that driver could check it */
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
for_each_online_cpu(sibling) {
|
|
struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling);
|
|
if (cp && cp->governor &&
|
|
(cpumask_test_cpu(cpu, cp->related_cpus))) {
|
|
policy->governor = cp->governor;
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
#endif
|
|
if (!found)
|
|
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
|
|
/* 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 err_unlock_policy;
|
|
}
|
|
policy->user_policy.min = policy->min;
|
|
policy->user_policy.max = policy->max;
|
|
|
|
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
|
|
CPUFREQ_START, policy);
|
|
|
|
ret = cpufreq_add_dev_policy(cpu, policy, dev);
|
|
if (ret) {
|
|
if (ret > 0)
|
|
/* This is a managed cpu, symlink created,
|
|
exit with 0 */
|
|
ret = 0;
|
|
goto err_unlock_policy;
|
|
}
|
|
|
|
ret = cpufreq_add_dev_interface(cpu, policy, dev);
|
|
if (ret)
|
|
goto err_out_unregister;
|
|
|
|
unlock_policy_rwsem_write(cpu);
|
|
|
|
kobject_uevent(&policy->kobj, KOBJ_ADD);
|
|
module_put(cpufreq_driver->owner);
|
|
pr_debug("initialization complete\n");
|
|
|
|
return 0;
|
|
|
|
|
|
err_out_unregister:
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
for_each_cpu(j, policy->cpus)
|
|
per_cpu(cpufreq_cpu_data, j) = NULL;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
kobject_put(&policy->kobj);
|
|
wait_for_completion(&policy->kobj_unregister);
|
|
|
|
err_unlock_policy:
|
|
unlock_policy_rwsem_write(cpu);
|
|
free_cpumask_var(policy->related_cpus);
|
|
err_free_cpumask:
|
|
free_cpumask_var(policy->cpus);
|
|
err_free_policy:
|
|
kfree(policy);
|
|
nomem_out:
|
|
module_put(cpufreq_driver->owner);
|
|
module_out:
|
|
return ret;
|
|
}
|
|
|
|
|
|
/**
|
|
* __cpufreq_remove_dev - remove a CPU device
|
|
*
|
|
* Removes the cpufreq interface for a CPU device.
|
|
* Caller should already have policy_rwsem in write mode for this CPU.
|
|
* This routine frees the rwsem before returning.
|
|
*/
|
|
static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
|
|
{
|
|
unsigned int cpu = dev->id;
|
|
unsigned long flags;
|
|
struct cpufreq_policy *data;
|
|
struct kobject *kobj;
|
|
struct completion *cmp;
|
|
#ifdef CONFIG_SMP
|
|
struct device *cpu_dev;
|
|
unsigned int j;
|
|
#endif
|
|
|
|
pr_debug("unregistering CPU %u\n", cpu);
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
data = per_cpu(cpufreq_cpu_data, cpu);
|
|
|
|
if (!data) {
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
unlock_policy_rwsem_write(cpu);
|
|
return -EINVAL;
|
|
}
|
|
per_cpu(cpufreq_cpu_data, cpu) = NULL;
|
|
|
|
|
|
#ifdef CONFIG_SMP
|
|
/* if this isn't the CPU which is the parent of the kobj, we
|
|
* only need to unlink, put and exit
|
|
*/
|
|
if (unlikely(cpu != data->cpu)) {
|
|
pr_debug("removing link\n");
|
|
cpumask_clear_cpu(cpu, data->cpus);
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
kobj = &dev->kobj;
|
|
cpufreq_cpu_put(data);
|
|
unlock_policy_rwsem_write(cpu);
|
|
sysfs_remove_link(kobj, "cpufreq");
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_SMP
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name,
|
|
CPUFREQ_NAME_LEN);
|
|
#endif
|
|
|
|
/* if we have other CPUs still registered, we need to unlink them,
|
|
* or else wait_for_completion below will lock up. Clean the
|
|
* per_cpu(cpufreq_cpu_data) while holding the lock, and remove
|
|
* the sysfs links afterwards.
|
|
*/
|
|
if (unlikely(cpumask_weight(data->cpus) > 1)) {
|
|
for_each_cpu(j, data->cpus) {
|
|
if (j == cpu)
|
|
continue;
|
|
per_cpu(cpufreq_cpu_data, j) = NULL;
|
|
}
|
|
}
|
|
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
if (unlikely(cpumask_weight(data->cpus) > 1)) {
|
|
for_each_cpu(j, data->cpus) {
|
|
if (j == cpu)
|
|
continue;
|
|
pr_debug("removing link for cpu %u\n", j);
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
strncpy(per_cpu(cpufreq_cpu_governor, j),
|
|
data->governor->name, CPUFREQ_NAME_LEN);
|
|
#endif
|
|
cpu_dev = get_cpu_device(j);
|
|
kobj = &cpu_dev->kobj;
|
|
unlock_policy_rwsem_write(cpu);
|
|
sysfs_remove_link(kobj, "cpufreq");
|
|
lock_policy_rwsem_write(cpu);
|
|
cpufreq_cpu_put(data);
|
|
}
|
|
}
|
|
#else
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
#endif
|
|
|
|
if (cpufreq_driver->target)
|
|
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
|
|
|
|
kobj = &data->kobj;
|
|
cmp = &data->kobj_unregister;
|
|
unlock_policy_rwsem_write(cpu);
|
|
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");
|
|
|
|
lock_policy_rwsem_write(cpu);
|
|
if (cpufreq_driver->exit)
|
|
cpufreq_driver->exit(data);
|
|
unlock_policy_rwsem_write(cpu);
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
/* when the CPU which is the parent of the kobj is hotplugged
|
|
* offline, check for siblings, and create cpufreq sysfs interface
|
|
* and symlinks
|
|
*/
|
|
if (unlikely(cpumask_weight(data->cpus) > 1)) {
|
|
/* first sibling now owns the new sysfs dir */
|
|
cpumask_clear_cpu(cpu, data->cpus);
|
|
cpufreq_add_dev(get_cpu_device(cpumask_first(data->cpus)), NULL);
|
|
|
|
/* finally remove our own symlink */
|
|
lock_policy_rwsem_write(cpu);
|
|
__cpufreq_remove_dev(dev, sif);
|
|
}
|
|
#endif
|
|
|
|
free_cpumask_var(data->related_cpus);
|
|
free_cpumask_var(data->cpus);
|
|
kfree(data);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
|
|
{
|
|
unsigned int cpu = dev->id;
|
|
int retval;
|
|
|
|
if (cpu_is_offline(cpu))
|
|
return 0;
|
|
|
|
if (unlikely(lock_policy_rwsem_write(cpu)))
|
|
BUG();
|
|
|
|
retval = __cpufreq_remove_dev(dev, sif);
|
|
return retval;
|
|
}
|
|
|
|
|
|
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);
|
|
}
|
|
|
|
/**
|
|
* cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble.
|
|
* @cpu: cpu number
|
|
* @old_freq: CPU frequency the kernel thinks the CPU runs at
|
|
* @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(unsigned int cpu, unsigned int old_freq,
|
|
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", old_freq, new_freq);
|
|
|
|
freqs.cpu = cpu;
|
|
freqs.old = old_freq;
|
|
freqs.new = new_freq;
|
|
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
|
|
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
|
|
}
|
|
|
|
|
|
/**
|
|
* 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 = cpufreq_cpu_get(cpu);
|
|
unsigned int ret_freq = 0;
|
|
|
|
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(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
|
|
unsigned int ret_freq = 0;
|
|
|
|
if (!cpufreq_driver->get)
|
|
return ret_freq;
|
|
|
|
ret_freq = cpufreq_driver->get(cpu);
|
|
|
|
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(cpu, policy->cur, 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)
|
|
{
|
|
unsigned int ret_freq = 0;
|
|
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
|
|
|
|
if (!policy)
|
|
goto out;
|
|
|
|
if (unlikely(lock_policy_rwsem_read(cpu)))
|
|
goto out_policy;
|
|
|
|
ret_freq = __cpufreq_get(cpu);
|
|
|
|
unlock_policy_rwsem_read(cpu);
|
|
|
|
out_policy:
|
|
cpufreq_cpu_put(policy);
|
|
out:
|
|
return ret_freq;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_get);
|
|
|
|
static struct subsys_interface cpufreq_interface = {
|
|
.name = "cpufreq",
|
|
.subsys = &cpu_subsys,
|
|
.add_dev = cpufreq_add_dev,
|
|
.remove_dev = cpufreq_remove_dev,
|
|
};
|
|
|
|
|
|
/**
|
|
* cpufreq_bp_suspend - Prepare the boot CPU for system suspend.
|
|
*
|
|
* This function is only executed for the boot processor. The other CPUs
|
|
* have been put offline by means of CPU hotplug.
|
|
*/
|
|
static int cpufreq_bp_suspend(void)
|
|
{
|
|
int ret = 0;
|
|
|
|
int cpu = smp_processor_id();
|
|
struct cpufreq_policy *cpu_policy;
|
|
|
|
pr_debug("suspending cpu %u\n", cpu);
|
|
|
|
/* If there's no policy for the boot CPU, we have nothing to do. */
|
|
cpu_policy = cpufreq_cpu_get(cpu);
|
|
if (!cpu_policy)
|
|
return 0;
|
|
|
|
if (cpufreq_driver->suspend) {
|
|
ret = cpufreq_driver->suspend(cpu_policy);
|
|
if (ret)
|
|
printk(KERN_ERR "cpufreq: suspend failed in ->suspend "
|
|
"step on CPU %u\n", cpu_policy->cpu);
|
|
}
|
|
|
|
cpufreq_cpu_put(cpu_policy);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* cpufreq_bp_resume - Restore proper frequency handling of the boot CPU.
|
|
*
|
|
* 1.) resume CPUfreq hardware support (cpufreq_driver->resume())
|
|
* 2.) schedule call cpufreq_update_policy() ASAP as interrupts are
|
|
* restored. It will verify that the current freq is in sync with
|
|
* what we believe it to be. This is a bit later than when it
|
|
* should be, but nonethteless it's better than calling
|
|
* cpufreq_driver->get() here which might re-enable interrupts...
|
|
*
|
|
* This function is only executed for the boot CPU. The other CPUs have not
|
|
* been turned on yet.
|
|
*/
|
|
static void cpufreq_bp_resume(void)
|
|
{
|
|
int ret = 0;
|
|
|
|
int cpu = smp_processor_id();
|
|
struct cpufreq_policy *cpu_policy;
|
|
|
|
pr_debug("resuming cpu %u\n", cpu);
|
|
|
|
/* If there's no policy for the boot CPU, we have nothing to do. */
|
|
cpu_policy = cpufreq_cpu_get(cpu);
|
|
if (!cpu_policy)
|
|
return;
|
|
|
|
if (cpufreq_driver->resume) {
|
|
ret = cpufreq_driver->resume(cpu_policy);
|
|
if (ret) {
|
|
printk(KERN_ERR "cpufreq: resume failed in ->resume "
|
|
"step on CPU %u\n", cpu_policy->cpu);
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
schedule_work(&cpu_policy->update);
|
|
|
|
fail:
|
|
cpufreq_cpu_put(cpu_policy);
|
|
}
|
|
|
|
static struct syscore_ops cpufreq_syscore_ops = {
|
|
.suspend = cpufreq_bp_suspend,
|
|
.resume = cpufreq_bp_resume,
|
|
};
|
|
|
|
|
|
/*********************************************************************
|
|
* 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;
|
|
|
|
WARN_ON(!init_cpufreq_transition_notifier_list_called);
|
|
|
|
switch (list) {
|
|
case CPUFREQ_TRANSITION_NOTIFIER:
|
|
ret = srcu_notifier_chain_register(
|
|
&cpufreq_transition_notifier_list, nb);
|
|
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;
|
|
|
|
switch (list) {
|
|
case CPUFREQ_TRANSITION_NOTIFIER:
|
|
ret = srcu_notifier_chain_unregister(
|
|
&cpufreq_transition_notifier_list, nb);
|
|
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 *
|
|
*********************************************************************/
|
|
|
|
|
|
int __cpufreq_driver_target(struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
int retval = -EINVAL;
|
|
|
|
if (cpufreq_disabled())
|
|
return -ENODEV;
|
|
|
|
pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
|
|
target_freq, relation);
|
|
if (cpu_online(policy->cpu) && cpufreq_driver->target)
|
|
retval = cpufreq_driver->target(policy, target_freq, relation);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
|
|
|
|
int cpufreq_driver_target(struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
int ret = -EINVAL;
|
|
|
|
policy = cpufreq_cpu_get(policy->cpu);
|
|
if (!policy)
|
|
goto no_policy;
|
|
|
|
if (unlikely(lock_policy_rwsem_write(policy->cpu)))
|
|
goto fail;
|
|
|
|
ret = __cpufreq_driver_target(policy, target_freq, relation);
|
|
|
|
unlock_policy_rwsem_write(policy->cpu);
|
|
|
|
fail:
|
|
cpufreq_cpu_put(policy);
|
|
no_policy:
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_driver_target);
|
|
|
|
int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu)
|
|
{
|
|
int ret = 0;
|
|
|
|
policy = cpufreq_cpu_get(policy->cpu);
|
|
if (!policy)
|
|
return -EINVAL;
|
|
|
|
if (cpu_online(cpu) && cpufreq_driver->getavg)
|
|
ret = cpufreq_driver->getavg(policy, cpu);
|
|
|
|
cpufreq_cpu_put(policy);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg);
|
|
|
|
/*
|
|
* when "event" is CPUFREQ_GOV_LIMITS
|
|
*/
|
|
|
|
static int __cpufreq_governor(struct cpufreq_policy *policy,
|
|
unsigned int event)
|
|
{
|
|
int ret;
|
|
|
|
/* Only must be defined when default governor is known to have latency
|
|
restrictions, like e.g. conservative or ondemand.
|
|
That this is the case is already ensured in Kconfig
|
|
*/
|
|
#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
|
|
struct cpufreq_governor *gov = &cpufreq_gov_performance;
|
|
#else
|
|
struct cpufreq_governor *gov = NULL;
|
|
#endif
|
|
|
|
if (policy->governor->max_transition_latency &&
|
|
policy->cpuinfo.transition_latency >
|
|
policy->governor->max_transition_latency) {
|
|
if (!gov)
|
|
return -EINVAL;
|
|
else {
|
|
printk(KERN_WARNING "%s governor failed, too long"
|
|
" transition latency of HW, fallback"
|
|
" to %s governor\n",
|
|
policy->governor->name,
|
|
gov->name);
|
|
policy->governor = gov;
|
|
}
|
|
}
|
|
|
|
if (!try_module_get(policy->governor->owner))
|
|
return -EINVAL;
|
|
|
|
pr_debug("__cpufreq_governor for CPU %u, event %u\n",
|
|
policy->cpu, event);
|
|
ret = policy->governor->governor(policy, event);
|
|
|
|
/* we keep one module reference alive for
|
|
each CPU governed by this CPU */
|
|
if ((event != CPUFREQ_GOV_START) || ret)
|
|
module_put(policy->governor->owner);
|
|
if ((event == CPUFREQ_GOV_STOP) && !ret)
|
|
module_put(policy->governor->owner);
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
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) == NULL) {
|
|
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)
|
|
{
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
int cpu;
|
|
#endif
|
|
|
|
if (!governor)
|
|
return;
|
|
|
|
if (cpufreq_disabled())
|
|
return;
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
for_each_present_cpu(cpu) {
|
|
if (cpu_online(cpu))
|
|
continue;
|
|
if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name))
|
|
strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0");
|
|
}
|
|
#endif
|
|
|
|
mutex_lock(&cpufreq_governor_mutex);
|
|
list_del(&governor->governor_list);
|
|
mutex_unlock(&cpufreq_governor_mutex);
|
|
return;
|
|
}
|
|
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(struct cpufreq_policy));
|
|
|
|
cpufreq_cpu_put(cpu_policy);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_get_policy);
|
|
|
|
|
|
/*
|
|
* data : current policy.
|
|
* policy : policy to be set.
|
|
*/
|
|
static int __cpufreq_set_policy(struct cpufreq_policy *data,
|
|
struct cpufreq_policy *policy)
|
|
{
|
|
int ret = 0;
|
|
|
|
pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu,
|
|
policy->min, policy->max);
|
|
|
|
memcpy(&policy->cpuinfo, &data->cpuinfo,
|
|
sizeof(struct cpufreq_cpuinfo));
|
|
|
|
if (policy->min > data->max || policy->max < data->min) {
|
|
ret = -EINVAL;
|
|
goto error_out;
|
|
}
|
|
|
|
/* verify the cpu speed can be set within this limit */
|
|
ret = cpufreq_driver->verify(policy);
|
|
if (ret)
|
|
goto error_out;
|
|
|
|
/* adjust if necessary - all reasons */
|
|
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
|
|
CPUFREQ_ADJUST, policy);
|
|
|
|
/* adjust if necessary - hardware incompatibility*/
|
|
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
|
|
CPUFREQ_INCOMPATIBLE, policy);
|
|
|
|
/* verify the cpu speed can be set within this limit,
|
|
which might be different to the first one */
|
|
ret = cpufreq_driver->verify(policy);
|
|
if (ret)
|
|
goto error_out;
|
|
|
|
/* notification of the new policy */
|
|
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
|
|
CPUFREQ_NOTIFY, policy);
|
|
|
|
data->min = policy->min;
|
|
data->max = policy->max;
|
|
|
|
pr_debug("new min and max freqs are %u - %u kHz\n",
|
|
data->min, data->max);
|
|
|
|
if (cpufreq_driver->setpolicy) {
|
|
data->policy = policy->policy;
|
|
pr_debug("setting range\n");
|
|
ret = cpufreq_driver->setpolicy(policy);
|
|
} else {
|
|
if (policy->governor != data->governor) {
|
|
/* save old, working values */
|
|
struct cpufreq_governor *old_gov = data->governor;
|
|
|
|
pr_debug("governor switch\n");
|
|
|
|
/* end old governor */
|
|
if (data->governor)
|
|
__cpufreq_governor(data, CPUFREQ_GOV_STOP);
|
|
|
|
/* start new governor */
|
|
data->governor = policy->governor;
|
|
if (__cpufreq_governor(data, CPUFREQ_GOV_START)) {
|
|
/* new governor failed, so re-start old one */
|
|
pr_debug("starting governor %s failed\n",
|
|
data->governor->name);
|
|
if (old_gov) {
|
|
data->governor = old_gov;
|
|
__cpufreq_governor(data,
|
|
CPUFREQ_GOV_START);
|
|
}
|
|
ret = -EINVAL;
|
|
goto error_out;
|
|
}
|
|
/* might be a policy change, too, so fall through */
|
|
}
|
|
pr_debug("governor: change or update limits\n");
|
|
__cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
|
|
}
|
|
|
|
error_out:
|
|
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.
|
|
*/
|
|
int cpufreq_update_policy(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *data = cpufreq_cpu_get(cpu);
|
|
struct cpufreq_policy policy;
|
|
int ret;
|
|
|
|
if (!data) {
|
|
ret = -ENODEV;
|
|
goto no_policy;
|
|
}
|
|
|
|
if (unlikely(lock_policy_rwsem_write(cpu))) {
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
pr_debug("updating policy for CPU %u\n", cpu);
|
|
memcpy(&policy, data, sizeof(struct cpufreq_policy));
|
|
policy.min = data->user_policy.min;
|
|
policy.max = data->user_policy.max;
|
|
policy.policy = data->user_policy.policy;
|
|
policy.governor = data->user_policy.governor;
|
|
|
|
/* BIOS might change freq behind our back
|
|
-> ask driver for current freq and notify governors about a change */
|
|
if (cpufreq_driver->get) {
|
|
policy.cur = cpufreq_driver->get(cpu);
|
|
if (!data->cur) {
|
|
pr_debug("Driver did not initialize current freq");
|
|
data->cur = policy.cur;
|
|
} else {
|
|
if (data->cur != policy.cur)
|
|
cpufreq_out_of_sync(cpu, data->cur,
|
|
policy.cur);
|
|
}
|
|
}
|
|
|
|
ret = __cpufreq_set_policy(data, &policy);
|
|
|
|
unlock_policy_rwsem_write(cpu);
|
|
|
|
fail:
|
|
cpufreq_cpu_put(data);
|
|
no_policy:
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(cpufreq_update_policy);
|
|
|
|
static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
unsigned int cpu = (unsigned long)hcpu;
|
|
struct device *dev;
|
|
|
|
dev = get_cpu_device(cpu);
|
|
if (dev) {
|
|
switch (action) {
|
|
case CPU_ONLINE:
|
|
case CPU_ONLINE_FROZEN:
|
|
cpufreq_add_dev(dev, NULL);
|
|
break;
|
|
case CPU_DOWN_PREPARE:
|
|
case CPU_DOWN_PREPARE_FROZEN:
|
|
if (unlikely(lock_policy_rwsem_write(cpu)))
|
|
BUG();
|
|
|
|
__cpufreq_remove_dev(dev, NULL);
|
|
break;
|
|
case CPU_DOWN_FAILED:
|
|
case CPU_DOWN_FAILED_FROZEN:
|
|
cpufreq_add_dev(dev, NULL);
|
|
break;
|
|
}
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block __refdata cpufreq_cpu_notifier = {
|
|
.notifier_call = cpufreq_cpu_callback,
|
|
};
|
|
|
|
/*********************************************************************
|
|
* REGISTER / UNREGISTER CPUFREQ DRIVER *
|
|
*********************************************************************/
|
|
|
|
/**
|
|
* 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, -EBUSY 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)))
|
|
return -EINVAL;
|
|
|
|
pr_debug("trying to register driver %s\n", driver_data->name);
|
|
|
|
if (driver_data->setpolicy)
|
|
driver_data->flags |= CPUFREQ_CONST_LOOPS;
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
if (cpufreq_driver) {
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
return -EBUSY;
|
|
}
|
|
cpufreq_driver = driver_data;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
ret = subsys_interface_register(&cpufreq_interface);
|
|
if (ret)
|
|
goto err_null_driver;
|
|
|
|
if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) {
|
|
int i;
|
|
ret = -ENODEV;
|
|
|
|
/* check for at least one working CPU */
|
|
for (i = 0; i < nr_cpu_ids; i++)
|
|
if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
|
|
/* if all ->init() calls failed, unregister */
|
|
if (ret) {
|
|
pr_debug("no CPU initialized for driver %s\n",
|
|
driver_data->name);
|
|
goto err_if_unreg;
|
|
}
|
|
}
|
|
|
|
register_hotcpu_notifier(&cpufreq_cpu_notifier);
|
|
pr_debug("driver %s up and running\n", driver_data->name);
|
|
|
|
return 0;
|
|
err_if_unreg:
|
|
subsys_interface_unregister(&cpufreq_interface);
|
|
err_null_driver:
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
cpufreq_driver = NULL;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
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);
|
|
|
|
subsys_interface_unregister(&cpufreq_interface);
|
|
unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
|
|
|
|
spin_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
cpufreq_driver = NULL;
|
|
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
|
|
|
|
static int __init cpufreq_core_init(void)
|
|
{
|
|
int cpu;
|
|
|
|
if (cpufreq_disabled())
|
|
return -ENODEV;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
per_cpu(cpufreq_policy_cpu, cpu) = -1;
|
|
init_rwsem(&per_cpu(cpu_policy_rwsem, cpu));
|
|
}
|
|
|
|
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;
|
|
}
|
|
core_initcall(cpufreq_core_init);
|