mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 02:39:48 +00:00
![Dietmar Eggemann](/assets/img/avatar_default.png)
Frequency-invariant accounting support based on the ratio of current frequency and maximum supported frequency is an optional feature an arch can implement. Since there are cpufreq drivers (e.g. cpufreq-dt) which can be build for different arch's a default implementation of the frequency-invariance setter function arch_set_freq_scale() is needed. This default implementation is an empty weak function which will be overwritten by a strong function in case the arch provides one. The setter function passes the cpumask of related (to the frequency change) cpus (online and offline cpus), the (new) current frequency and the maximum supported frequency. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2604 lines
67 KiB
C
2604 lines
67 KiB
C
/*
|
|
* linux/drivers/cpufreq/cpufreq.c
|
|
*
|
|
* Copyright (C) 2001 Russell King
|
|
* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
|
|
* (C) 2013 Viresh Kumar <viresh.kumar@linaro.org>
|
|
*
|
|
* Oct 2005 - Ashok Raj <ashok.raj@intel.com>
|
|
* Added handling for CPU hotplug
|
|
* Feb 2006 - Jacob Shin <jacob.shin@amd.com>
|
|
* Fix handling for CPU hotplug -- affected CPUs
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/cpu.h>
|
|
#include <linux/cpufreq.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/device.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/suspend.h>
|
|
#include <linux/syscore_ops.h>
|
|
#include <linux/tick.h>
|
|
#include <trace/events/power.h>
|
|
|
|
static LIST_HEAD(cpufreq_policy_list);
|
|
|
|
static inline bool policy_is_inactive(struct cpufreq_policy *policy)
|
|
{
|
|
return cpumask_empty(policy->cpus);
|
|
}
|
|
|
|
/* Macros to iterate over CPU policies */
|
|
#define for_each_suitable_policy(__policy, __active) \
|
|
list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
|
|
if ((__active) == !policy_is_inactive(__policy))
|
|
|
|
#define for_each_active_policy(__policy) \
|
|
for_each_suitable_policy(__policy, true)
|
|
#define for_each_inactive_policy(__policy) \
|
|
for_each_suitable_policy(__policy, false)
|
|
|
|
#define for_each_policy(__policy) \
|
|
list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
|
|
|
|
/* Iterate over governors */
|
|
static LIST_HEAD(cpufreq_governor_list);
|
|
#define for_each_governor(__governor) \
|
|
list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
|
|
|
|
/**
|
|
* The "cpufreq driver" - the arch- or hardware-dependent low
|
|
* level driver of CPUFreq support, and its spinlock. This lock
|
|
* also protects the cpufreq_cpu_data array.
|
|
*/
|
|
static struct cpufreq_driver *cpufreq_driver;
|
|
static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
|
|
static DEFINE_RWLOCK(cpufreq_driver_lock);
|
|
|
|
/* Flag to suspend/resume CPUFreq governors */
|
|
static bool cpufreq_suspended;
|
|
|
|
static inline bool has_target(void)
|
|
{
|
|
return cpufreq_driver->target_index || cpufreq_driver->target;
|
|
}
|
|
|
|
/* internal prototypes */
|
|
static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
|
|
static int cpufreq_init_governor(struct cpufreq_policy *policy);
|
|
static void cpufreq_exit_governor(struct cpufreq_policy *policy);
|
|
static int cpufreq_start_governor(struct cpufreq_policy *policy);
|
|
static void cpufreq_stop_governor(struct cpufreq_policy *policy);
|
|
static void cpufreq_governor_limits(struct cpufreq_policy *policy);
|
|
|
|
/**
|
|
* Two notifier lists: the "policy" list is involved in the
|
|
* validation process for a new CPU frequency policy; the
|
|
* "transition" list for kernel code that needs to handle
|
|
* changes to devices when the CPU clock speed changes.
|
|
* The mutex locks both lists.
|
|
*/
|
|
static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
|
|
static struct srcu_notifier_head cpufreq_transition_notifier_list;
|
|
|
|
static bool init_cpufreq_transition_notifier_list_called;
|
|
static int __init init_cpufreq_transition_notifier_list(void)
|
|
{
|
|
srcu_init_notifier_head(&cpufreq_transition_notifier_list);
|
|
init_cpufreq_transition_notifier_list_called = true;
|
|
return 0;
|
|
}
|
|
pure_initcall(init_cpufreq_transition_notifier_list);
|
|
|
|
static int off __read_mostly;
|
|
static int cpufreq_disabled(void)
|
|
{
|
|
return off;
|
|
}
|
|
void disable_cpufreq(void)
|
|
{
|
|
off = 1;
|
|
}
|
|
static DEFINE_MUTEX(cpufreq_governor_mutex);
|
|
|
|
bool have_governor_per_policy(void)
|
|
{
|
|
return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
|
|
}
|
|
EXPORT_SYMBOL_GPL(have_governor_per_policy);
|
|
|
|
struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
|
|
{
|
|
if (have_governor_per_policy())
|
|
return &policy->kobj;
|
|
else
|
|
return cpufreq_global_kobject;
|
|
}
|
|
EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
|
|
|
|
static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
|
|
{
|
|
u64 idle_time;
|
|
u64 cur_wall_time;
|
|
u64 busy_time;
|
|
|
|
cur_wall_time = jiffies64_to_nsecs(get_jiffies_64());
|
|
|
|
busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
|
|
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
|
|
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
|
|
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
|
|
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
|
|
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
|
|
|
|
idle_time = cur_wall_time - busy_time;
|
|
if (wall)
|
|
*wall = div_u64(cur_wall_time, NSEC_PER_USEC);
|
|
|
|
return div_u64(idle_time, NSEC_PER_USEC);
|
|
}
|
|
|
|
u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
|
|
{
|
|
u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
|
|
|
|
if (idle_time == -1ULL)
|
|
return get_cpu_idle_time_jiffy(cpu, wall);
|
|
else if (!io_busy)
|
|
idle_time += get_cpu_iowait_time_us(cpu, wall);
|
|
|
|
return idle_time;
|
|
}
|
|
EXPORT_SYMBOL_GPL(get_cpu_idle_time);
|
|
|
|
__weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
|
|
unsigned long max_freq)
|
|
{
|
|
}
|
|
EXPORT_SYMBOL_GPL(arch_set_freq_scale);
|
|
|
|
/*
|
|
* This is a generic cpufreq init() routine which can be used by cpufreq
|
|
* drivers of SMP systems. It will do following:
|
|
* - validate & show freq table passed
|
|
* - set policies transition latency
|
|
* - policy->cpus with all possible CPUs
|
|
*/
|
|
int cpufreq_generic_init(struct cpufreq_policy *policy,
|
|
struct cpufreq_frequency_table *table,
|
|
unsigned int transition_latency)
|
|
{
|
|
int ret;
|
|
|
|
ret = cpufreq_table_validate_and_show(policy, table);
|
|
if (ret) {
|
|
pr_err("%s: invalid frequency table: %d\n", __func__, ret);
|
|
return ret;
|
|
}
|
|
|
|
policy->cpuinfo.transition_latency = transition_latency;
|
|
|
|
/*
|
|
* The driver only supports the SMP configuration where all processors
|
|
* share the clock and voltage and clock.
|
|
*/
|
|
cpumask_setall(policy->cpus);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_generic_init);
|
|
|
|
struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
|
|
|
|
return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
|
|
|
|
unsigned int cpufreq_generic_get(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
|
|
|
|
if (!policy || IS_ERR(policy->clk)) {
|
|
pr_err("%s: No %s associated to cpu: %d\n",
|
|
__func__, policy ? "clk" : "policy", cpu);
|
|
return 0;
|
|
}
|
|
|
|
return clk_get_rate(policy->clk) / 1000;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_generic_get);
|
|
|
|
/**
|
|
* cpufreq_cpu_get: returns policy for a cpu and marks it busy.
|
|
*
|
|
* @cpu: cpu to find policy for.
|
|
*
|
|
* This returns policy for 'cpu', returns NULL if it doesn't exist.
|
|
* It also increments the kobject reference count to mark it busy and so would
|
|
* require a corresponding call to cpufreq_cpu_put() to decrement it back.
|
|
* If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be
|
|
* freed as that depends on the kobj count.
|
|
*
|
|
* Return: A valid policy on success, otherwise NULL on failure.
|
|
*/
|
|
struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
|
|
{
|
|
struct cpufreq_policy *policy = NULL;
|
|
unsigned long flags;
|
|
|
|
if (WARN_ON(cpu >= nr_cpu_ids))
|
|
return NULL;
|
|
|
|
/* get the cpufreq driver */
|
|
read_lock_irqsave(&cpufreq_driver_lock, flags);
|
|
|
|
if (cpufreq_driver) {
|
|
/* get the CPU */
|
|
policy = cpufreq_cpu_get_raw(cpu);
|
|
if (policy)
|
|
kobject_get(&policy->kobj);
|
|
}
|
|
|
|
read_unlock_irqrestore(&cpufreq_driver_lock, flags);
|
|
|
|
return policy;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
|
|
|
|
/**
|
|
* cpufreq_cpu_put: Decrements the usage count of a policy
|
|
*
|
|
* @policy: policy earlier returned by cpufreq_cpu_get().
|
|
*
|
|
* This decrements the kobject reference count incremented earlier by calling
|
|
* cpufreq_cpu_get().
|
|
*/
|
|
void cpufreq_cpu_put(struct cpufreq_policy *policy)
|
|
{
|
|
kobject_put(&policy->kobj);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
|
|
|
|
/*********************************************************************
|
|
* EXTERNALLY AFFECTING FREQUENCY CHANGES *
|
|
*********************************************************************/
|
|
|
|
/**
|
|
* adjust_jiffies - adjust the system "loops_per_jiffy"
|
|
*
|
|
* This function alters the system "loops_per_jiffy" for the clock
|
|
* speed change. Note that loops_per_jiffy cannot be updated on SMP
|
|
* systems as each CPU might be scaled differently. So, use the arch
|
|
* per-CPU loops_per_jiffy value wherever possible.
|
|
*/
|
|
static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
|
|
{
|
|
#ifndef CONFIG_SMP
|
|
static unsigned long l_p_j_ref;
|
|
static unsigned int l_p_j_ref_freq;
|
|
|
|
if (ci->flags & CPUFREQ_CONST_LOOPS)
|
|
return;
|
|
|
|
if (!l_p_j_ref_freq) {
|
|
l_p_j_ref = loops_per_jiffy;
|
|
l_p_j_ref_freq = ci->old;
|
|
pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
|
|
l_p_j_ref, l_p_j_ref_freq);
|
|
}
|
|
if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
|
|
loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
|
|
ci->new);
|
|
pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
|
|
loops_per_jiffy, ci->new);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
|
|
struct cpufreq_freqs *freqs, unsigned int state)
|
|
{
|
|
BUG_ON(irqs_disabled());
|
|
|
|
if (cpufreq_disabled())
|
|
return;
|
|
|
|
freqs->flags = cpufreq_driver->flags;
|
|
pr_debug("notification %u of frequency transition to %u kHz\n",
|
|
state, freqs->new);
|
|
|
|
switch (state) {
|
|
|
|
case CPUFREQ_PRECHANGE:
|
|
/* detect if the driver reported a value as "old frequency"
|
|
* which is not equal to what the cpufreq core thinks is
|
|
* "old frequency".
|
|
*/
|
|
if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
|
|
if ((policy) && (policy->cpu == freqs->cpu) &&
|
|
(policy->cur) && (policy->cur != freqs->old)) {
|
|
pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
|
|
freqs->old, policy->cur);
|
|
freqs->old = policy->cur;
|
|
}
|
|
}
|
|
srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
|
|
CPUFREQ_PRECHANGE, freqs);
|
|
adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
|
|
break;
|
|
|
|
case CPUFREQ_POSTCHANGE:
|
|
adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
|
|
pr_debug("FREQ: %lu - CPU: %lu\n",
|
|
(unsigned long)freqs->new, (unsigned long)freqs->cpu);
|
|
trace_cpu_frequency(freqs->new, freqs->cpu);
|
|
cpufreq_stats_record_transition(policy, freqs->new);
|
|
srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
|
|
CPUFREQ_POSTCHANGE, freqs);
|
|
if (likely(policy) && likely(policy->cpu == freqs->cpu))
|
|
policy->cur = freqs->new;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* cpufreq_notify_transition - call notifier chain and adjust_jiffies
|
|
* on frequency transition.
|
|
*
|
|
* This function calls the transition notifiers and the "adjust_jiffies"
|
|
* function. It is called twice on all CPU frequency changes that have
|
|
* external effects.
|
|
*/
|
|
static void cpufreq_notify_transition(struct cpufreq_policy *policy,
|
|
struct cpufreq_freqs *freqs, unsigned int state)
|
|
{
|
|
for_each_cpu(freqs->cpu, policy->cpus)
|
|
__cpufreq_notify_transition(policy, freqs, state);
|
|
}
|
|
|
|
/* Do post notifications when there are chances that transition has failed */
|
|
static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
|
|
struct cpufreq_freqs *freqs, int transition_failed)
|
|
{
|
|
cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
|
|
if (!transition_failed)
|
|
return;
|
|
|
|
swap(freqs->old, freqs->new);
|
|
cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
|
|
cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
|
|
}
|
|
|
|
void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
|
|
struct cpufreq_freqs *freqs)
|
|
{
|
|
|
|
/*
|
|
* Catch double invocations of _begin() which lead to self-deadlock.
|
|
* ASYNC_NOTIFICATION drivers are left out because the cpufreq core
|
|
* doesn't invoke _begin() on their behalf, and hence the chances of
|
|
* double invocations are very low. Moreover, there are scenarios
|
|
* where these checks can emit false-positive warnings in these
|
|
* drivers; so we avoid that by skipping them altogether.
|
|
*/
|
|
WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
|
|
&& current == policy->transition_task);
|
|
|
|
wait:
|
|
wait_event(policy->transition_wait, !policy->transition_ongoing);
|
|
|
|
spin_lock(&policy->transition_lock);
|
|
|
|
if (unlikely(policy->transition_ongoing)) {
|
|
spin_unlock(&policy->transition_lock);
|
|
goto wait;
|
|
}
|
|
|
|
policy->transition_ongoing = true;
|
|
policy->transition_task = current;
|
|
|
|
spin_unlock(&policy->transition_lock);
|
|
|
|
cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
|
|
|
|
void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
|
|
struct cpufreq_freqs *freqs, int transition_failed)
|
|
{
|
|
if (unlikely(WARN_ON(!policy->transition_ongoing)))
|
|
return;
|
|
|
|
cpufreq_notify_post_transition(policy, freqs, transition_failed);
|
|
|
|
policy->transition_ongoing = false;
|
|
policy->transition_task = NULL;
|
|
|
|
wake_up(&policy->transition_wait);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
|
|
|
|
/*
|
|
* Fast frequency switching status count. Positive means "enabled", negative
|
|
* means "disabled" and 0 means "not decided yet".
|
|
*/
|
|
static int cpufreq_fast_switch_count;
|
|
static DEFINE_MUTEX(cpufreq_fast_switch_lock);
|
|
|
|
static void cpufreq_list_transition_notifiers(void)
|
|
{
|
|
struct notifier_block *nb;
|
|
|
|
pr_info("Registered transition notifiers:\n");
|
|
|
|
mutex_lock(&cpufreq_transition_notifier_list.mutex);
|
|
|
|
for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
|
|
pr_info("%pF\n", nb->notifier_call);
|
|
|
|
mutex_unlock(&cpufreq_transition_notifier_list.mutex);
|
|
}
|
|
|
|
/**
|
|
* cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
|
|
* @policy: cpufreq policy to enable fast frequency switching for.
|
|
*
|
|
* Try to enable fast frequency switching for @policy.
|
|
*
|
|
* The attempt will fail if there is at least one transition notifier registered
|
|
* at this point, as fast frequency switching is quite fundamentally at odds
|
|
* with transition notifiers. Thus if successful, it will make registration of
|
|
* transition notifiers fail going forward.
|
|
*/
|
|
void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
|
|
{
|
|
lockdep_assert_held(&policy->rwsem);
|
|
|
|
if (!policy->fast_switch_possible)
|
|
return;
|
|
|
|
mutex_lock(&cpufreq_fast_switch_lock);
|
|
if (cpufreq_fast_switch_count >= 0) {
|
|
cpufreq_fast_switch_count++;
|
|
policy->fast_switch_enabled = true;
|
|
} else {
|
|
pr_warn("CPU%u: Fast frequency switching not enabled\n",
|
|
policy->cpu);
|
|
cpufreq_list_transition_notifiers();
|
|
}
|
|
mutex_unlock(&cpufreq_fast_switch_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
|
|
|
|
/**
|
|
* cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
|
|
* @policy: cpufreq policy to disable fast frequency switching for.
|
|
*/
|
|
void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
|
|
{
|
|
mutex_lock(&cpufreq_fast_switch_lock);
|
|
if (policy->fast_switch_enabled) {
|
|
policy->fast_switch_enabled = false;
|
|
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, unsigned int *policy,
|
|
struct cpufreq_governor **governor)
|
|
{
|
|
int err = -EINVAL;
|
|
|
|
if (cpufreq_driver->setpolicy) {
|
|
if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
|
|
*policy = CPUFREQ_POLICY_PERFORMANCE;
|
|
err = 0;
|
|
} else if (!strncasecmp(str_governor, "powersave",
|
|
CPUFREQ_NAME_LEN)) {
|
|
*policy = CPUFREQ_POLICY_POWERSAVE;
|
|
err = 0;
|
|
}
|
|
} else {
|
|
struct cpufreq_governor *t;
|
|
|
|
mutex_lock(&cpufreq_governor_mutex);
|
|
|
|
t = find_governor(str_governor);
|
|
|
|
if (t == NULL) {
|
|
int ret;
|
|
|
|
mutex_unlock(&cpufreq_governor_mutex);
|
|
ret = request_module("cpufreq_%s", str_governor);
|
|
mutex_lock(&cpufreq_governor_mutex);
|
|
|
|
if (ret == 0)
|
|
t = find_governor(str_governor);
|
|
}
|
|
|
|
if (t != NULL) {
|
|
*governor = t;
|
|
err = 0;
|
|
}
|
|
|
|
mutex_unlock(&cpufreq_governor_mutex);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* 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)); \
|
|
\
|
|
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.policy,
|
|
&new_policy.governor))
|
|
return -EINVAL;
|
|
|
|
ret = cpufreq_set_policy(policy, &new_policy);
|
|
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_lock();
|
|
|
|
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.policy,
|
|
NULL);
|
|
}
|
|
/* 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;
|
|
}
|
|
|
|
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_exit_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_exit_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_exit_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_exit_policy:
|
|
up_write(&policy->rwsem);
|
|
|
|
if (cpufreq_driver->exit)
|
|
cpufreq_driver->exit(policy);
|
|
|
|
for_each_cpu(j, policy->real_cpus)
|
|
remove_cpu_dev_symlink(policy, get_cpu_device(j));
|
|
|
|
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;
|
|
|
|
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;
|
|
|
|
WARN_ON(!init_cpufreq_transition_notifier_list_called);
|
|
|
|
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);
|
|
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(*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;
|
|
|
|
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);
|