| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * 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 |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/cpu.h> |
| #include <linux/cpufreq.h> |
| #include <linux/cpu_cooling.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/pm_qos.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); |
| |
| /* 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) |
| |
| static char default_governor[CPUFREQ_NAME_LEN]; |
| |
| /* |
| * 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); |
| |
| static DEFINE_STATIC_KEY_FALSE(cpufreq_freq_invariance); |
| bool cpufreq_supports_freq_invariance(void) |
| { |
| return static_branch_likely(&cpufreq_freq_invariance); |
| } |
| |
| /* 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 void cpufreq_governor_limits(struct cpufreq_policy *policy); |
| static int cpufreq_set_policy(struct cpufreq_policy *policy, |
| struct cpufreq_governor *new_gov, |
| unsigned int new_pol); |
| |
| /* |
| * 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); |
| SRCU_NOTIFIER_HEAD_STATIC(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); |
| |
| static struct kobject *cpufreq_global_kobject; |
| |
| 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) |
| { |
| struct kernel_cpustat kcpustat; |
| u64 cur_wall_time; |
| u64 idle_time; |
| u64 busy_time; |
| |
| cur_wall_time = jiffies64_to_nsecs(get_jiffies_64()); |
| |
| kcpustat_cpu_fetch(&kcpustat, cpu); |
| |
| busy_time = kcpustat.cpustat[CPUTIME_USER]; |
| busy_time += kcpustat.cpustat[CPUTIME_SYSTEM]; |
| busy_time += kcpustat.cpustat[CPUTIME_IRQ]; |
| busy_time += kcpustat.cpustat[CPUTIME_SOFTIRQ]; |
| busy_time += kcpustat.cpustat[CPUTIME_STEAL]; |
| busy_time += kcpustat.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); |
| |
| /* |
| * 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 |
| */ |
| void cpufreq_generic_init(struct cpufreq_policy *policy, |
| struct cpufreq_frequency_table *table, |
| unsigned int transition_latency) |
| { |
| policy->freq_table = table; |
| 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); |
| } |
| 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 - Return policy for a CPU and mark it as busy. |
| * @cpu: CPU to find the policy for. |
| * |
| * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment |
| * the kobject reference counter of that policy. Return a valid policy on |
| * success or NULL on failure. |
| * |
| * The policy returned by this function has to be released with the help of |
| * cpufreq_cpu_put() to balance its kobject reference counter properly. |
| */ |
| 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 - Decrement kobject usage counter for cpufreq policy. |
| * @policy: cpufreq policy returned by cpufreq_cpu_get(). |
| */ |
| void cpufreq_cpu_put(struct cpufreq_policy *policy) |
| { |
| kobject_put(&policy->kobj); |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_cpu_put); |
| |
| /** |
| * cpufreq_cpu_release - Unlock a policy and decrement its usage counter. |
| * @policy: cpufreq policy returned by cpufreq_cpu_acquire(). |
| */ |
| void cpufreq_cpu_release(struct cpufreq_policy *policy) |
| { |
| if (WARN_ON(!policy)) |
| return; |
| |
| lockdep_assert_held(&policy->rwsem); |
| |
| up_write(&policy->rwsem); |
| |
| cpufreq_cpu_put(policy); |
| } |
| |
| /** |
| * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it. |
| * @cpu: CPU to find the policy for. |
| * |
| * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and |
| * if the policy returned by it is not NULL, acquire its rwsem for writing. |
| * Return the policy if it is active or release it and return NULL otherwise. |
| * |
| * The policy returned by this function has to be released with the help of |
| * cpufreq_cpu_release() in order to release its rwsem and balance its usage |
| * counter properly. |
| */ |
| struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
| |
| if (!policy) |
| return NULL; |
| |
| down_write(&policy->rwsem); |
| |
| if (policy_is_inactive(policy)) { |
| cpufreq_cpu_release(policy); |
| return NULL; |
| } |
| |
| return policy; |
| } |
| |
| /********************************************************************* |
| * EXTERNALLY AFFECTING FREQUENCY CHANGES * |
| *********************************************************************/ |
| |
| /** |
| * adjust_jiffies - Adjust the system "loops_per_jiffy". |
| * @val: CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE. |
| * @ci: Frequency change information. |
| * |
| * 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 |
| } |
| |
| /** |
| * cpufreq_notify_transition - Notify frequency transition and adjust jiffies. |
| * @policy: cpufreq policy to enable fast frequency switching for. |
| * @freqs: contain details of the frequency update. |
| * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE. |
| * |
| * This function calls the transition notifiers and adjust_jiffies(). |
| * |
| * 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) |
| { |
| int cpu; |
| |
| BUG_ON(irqs_disabled()); |
| |
| if (cpufreq_disabled()) |
| return; |
| |
| freqs->policy = policy; |
| 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 (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: %u - CPUs: %*pbl\n", freqs->new, |
| cpumask_pr_args(policy->cpus)); |
| |
| for_each_cpu(cpu, policy->cpus) |
| trace_cpu_frequency(freqs->new, cpu); |
| |
| srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
| CPUFREQ_POSTCHANGE, freqs); |
| |
| cpufreq_stats_record_transition(policy, freqs->new); |
| policy->cur = freqs->new; |
| } |
| } |
| |
| /* 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 (WARN_ON(!policy->transition_ongoing)) |
| return; |
| |
| cpufreq_notify_post_transition(policy, freqs, transition_failed); |
| |
| arch_set_freq_scale(policy->related_cpus, |
| policy->cur, |
| policy->cpuinfo.max_freq); |
| |
| 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("%pS\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. |
| * @policy: associated policy to interrogate |
| * @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) { |
| unsigned 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 kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); |
| } |
| |
| static ssize_t store_boost(struct kobject *kobj, struct kobj_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; |
| } |
| |
| static struct cpufreq_governor *get_governor(const char *str_governor) |
| { |
| struct cpufreq_governor *t; |
| |
| mutex_lock(&cpufreq_governor_mutex); |
| t = find_governor(str_governor); |
| if (!t) |
| goto unlock; |
| |
| if (!try_module_get(t->owner)) |
| t = NULL; |
| |
| unlock: |
| mutex_unlock(&cpufreq_governor_mutex); |
| |
| return t; |
| } |
| |
| static unsigned int cpufreq_parse_policy(char *str_governor) |
| { |
| if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) |
| return CPUFREQ_POLICY_PERFORMANCE; |
| |
| if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) |
| return CPUFREQ_POLICY_POWERSAVE; |
| |
| return CPUFREQ_POLICY_UNKNOWN; |
| } |
| |
| /** |
| * cpufreq_parse_governor - parse a governor string only for has_target() |
| * @str_governor: Governor name. |
| */ |
| static struct cpufreq_governor *cpufreq_parse_governor(char *str_governor) |
| { |
| struct cpufreq_governor *t; |
| |
| t = get_governor(str_governor); |
| if (t) |
| return t; |
| |
| if (request_module("cpufreq_%s", str_governor)) |
| return NULL; |
| |
| return get_governor(str_governor); |
| } |
| |
| /* |
| * 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->setpolicy && cpufreq_driver->get) |
| ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu)); |
| else |
| ret = sprintf(buf, "%u\n", policy->cur); |
| return ret; |
| } |
| |
| /* |
| * 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) \ |
| { \ |
| unsigned long val; \ |
| int ret; \ |
| \ |
| ret = sscanf(buf, "%lu", &val); \ |
| if (ret != 1) \ |
| return -EINVAL; \ |
| \ |
| ret = freq_qos_update_request(policy->object##_freq_req, val);\ |
| return ret >= 0 ? count : ret; \ |
| } |
| |
| 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) |
| { |
| char str_governor[16]; |
| int ret; |
| |
| ret = sscanf(buf, "%15s", str_governor); |
| if (ret != 1) |
| return -EINVAL; |
| |
| if (cpufreq_driver->setpolicy) { |
| unsigned int new_pol; |
| |
| new_pol = cpufreq_parse_policy(str_governor); |
| if (!new_pol) |
| return -EINVAL; |
| |
| ret = cpufreq_set_policy(policy, NULL, new_pol); |
| } else { |
| struct cpufreq_governor *new_gov; |
| |
| new_gov = cpufreq_parse_governor(str_governor); |
| if (!new_gov) |
| return -EINVAL; |
| |
| ret = cpufreq_set_policy(policy, new_gov, |
| CPUFREQ_POLICY_UNKNOWN); |
| |
| module_put(new_gov->owner); |
| } |
| |
| return ret ? ret : count; |
| } |
| |
| /* |
| * show_scaling_driver - show the cpufreq driver currently loaded |
| */ |
| static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
| { |
| return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
| } |
| |
| /* |
| * show_scaling_available_governors - show the available CPUfreq governors |
| */ |
| static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
| char *buf) |
| { |
| ssize_t i = 0; |
| struct cpufreq_governor *t; |
| |
| if (!has_target()) { |
| i += sprintf(buf, "performance powersave"); |
| goto out; |
| } |
| |
| mutex_lock(&cpufreq_governor_mutex); |
| for_each_governor(t) { |
| if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
| - (CPUFREQ_NAME_LEN + 2))) |
| break; |
| i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
| } |
| mutex_unlock(&cpufreq_governor_mutex); |
| 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; |
| 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; |
| |
| if (!fattr->show) |
| return -EIO; |
| |
| 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; |
| |
| if (!fattr->store) |
| return -EIO; |
| |
| /* |
| * cpus_read_trylock() is used here to work around a circular lock |
| * dependency problem with respect to the cpufreq_register_driver(). |
| */ |
| if (!cpus_read_trylock()) |
| return -EBUSY; |
| |
| if (cpu_online(policy->cpu)) { |
| down_write(&policy->rwsem); |
| ret = fattr->store(policy, buf, count); |
| up_write(&policy->rwsem); |
| } |
| |
| cpus_read_unlock(); |
| |
| return ret; |
| } |
| |
| static void cpufreq_sysfs_release(struct kobject *kobj) |
| { |
| struct cpufreq_policy *policy = to_policy(kobj); |
| pr_debug("last reference is dropped\n"); |
| complete(&policy->kobj_unregister); |
| } |
| |
| static const struct sysfs_ops sysfs_ops = { |
| .show = show, |
| .store = store, |
| }; |
| |
| static struct kobj_type ktype_cpufreq = { |
| .sysfs_ops = &sysfs_ops, |
| .default_attrs = default_attrs, |
| .release = cpufreq_sysfs_release, |
| }; |
| |
| static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu) |
| { |
| struct device *dev = get_cpu_device(cpu); |
| |
| if (unlikely(!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; |
| } |
| |
| static int cpufreq_init_policy(struct cpufreq_policy *policy) |
| { |
| struct cpufreq_governor *gov = NULL; |
| unsigned int pol = CPUFREQ_POLICY_UNKNOWN; |
| int ret; |
| |
| if (has_target()) { |
| /* Update policy governor to the one used before hotplug. */ |
| gov = get_governor(policy->last_governor); |
| if (gov) { |
| pr_debug("Restoring governor %s for cpu %d\n", |
| gov->name, policy->cpu); |
| } else { |
| gov = get_governor(default_governor); |
| } |
| |
| if (!gov) { |
| gov = cpufreq_default_governor(); |
| __module_get(gov->owner); |
| } |
| |
| } else { |
| |
| /* Use the default policy if there is no last_policy. */ |
| if (policy->last_policy) { |
| pol = policy->last_policy; |
| } else { |
| pol = cpufreq_parse_policy(default_governor); |
| /* |
| * In case the default governor is neither "performance" |
| * nor "powersave", fall back to the initial policy |
| * value set by the driver. |
| */ |
| if (pol == CPUFREQ_POLICY_UNKNOWN) |
| pol = policy->policy; |
| } |
| if (pol != CPUFREQ_POLICY_PERFORMANCE && |
| pol != CPUFREQ_POLICY_POWERSAVE) |
| return -ENODATA; |
| } |
| |
| ret = cpufreq_set_policy(policy, gov, pol); |
| if (gov) |
| module_put(gov->owner); |
| |
| return ret; |
| } |
| |
| 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; |
| } |
| |
| void refresh_frequency_limits(struct cpufreq_policy *policy) |
| { |
| if (!policy_is_inactive(policy)) { |
| pr_debug("updating policy for CPU %u\n", policy->cpu); |
| |
| cpufreq_set_policy(policy, policy->governor, policy->policy); |
| } |
| } |
| EXPORT_SYMBOL(refresh_frequency_limits); |
| |
| static void handle_update(struct work_struct *work) |
| { |
| struct cpufreq_policy *policy = |
| container_of(work, struct cpufreq_policy, update); |
| |
| pr_debug("handle_update for cpu %u called\n", policy->cpu); |
| down_write(&policy->rwsem); |
| refresh_frequency_limits(policy); |
| up_write(&policy->rwsem); |
| } |
| |
| static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq, |
| void *data) |
| { |
| struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min); |
| |
| schedule_work(&policy->update); |
| return 0; |
| } |
| |
| static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq, |
| void *data) |
| { |
| struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max); |
| |
| schedule_work(&policy->update); |
| return 0; |
| } |
| |
| static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
| { |
| struct kobject *kobj; |
| struct completion *cmp; |
| |
| down_write(&policy->rwsem); |
| cpufreq_stats_free_table(policy); |
| kobj = &policy->kobj; |
| cmp = &policy->kobj_unregister; |
| up_write(&policy->rwsem); |
| kobject_put(kobj); |
| |
| /* |
| * We need to make sure that the underlying kobj is |
| * actually not referenced anymore by anybody before we |
| * proceed with unloading. |
| */ |
| pr_debug("waiting for dropping of refcount\n"); |
| wait_for_completion(cmp); |
| pr_debug("wait complete\n"); |
| } |
| |
| static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy; |
| struct device *dev = get_cpu_device(cpu); |
| int ret; |
| |
| if (!dev) |
| return NULL; |
| |
| policy = kzalloc(sizeof(*policy), GFP_KERNEL); |
| if (!policy) |
| return NULL; |
| |
| 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) { |
| dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret); |
| /* |
| * The entire policy object will be freed below, but the extra |
| * memory allocated for the kobject name needs to be freed by |
| * releasing the kobject. |
| */ |
| kobject_put(&policy->kobj); |
| goto err_free_real_cpus; |
| } |
| |
| freq_constraints_init(&policy->constraints); |
| |
| policy->nb_min.notifier_call = cpufreq_notifier_min; |
| policy->nb_max.notifier_call = cpufreq_notifier_max; |
| |
| ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MIN, |
| &policy->nb_min); |
| if (ret) { |
| dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n", |
| ret, cpumask_pr_args(policy->cpus)); |
| goto err_kobj_remove; |
| } |
| |
| ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MAX, |
| &policy->nb_max); |
| if (ret) { |
| dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n", |
| ret, cpumask_pr_args(policy->cpus)); |
| goto err_min_qos_notifier; |
| } |
| |
| INIT_LIST_HEAD(&policy->policy_list); |
| init_rwsem(&policy->rwsem); |
| spin_lock_init(&policy->transition_lock); |
| init_waitqueue_head(&policy->transition_wait); |
| init_completion(&policy->kobj_unregister); |
| INIT_WORK(&policy->update, handle_update); |
| |
| policy->cpu = cpu; |
| return policy; |
| |
| err_min_qos_notifier: |
| freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN, |
| &policy->nb_min); |
| err_kobj_remove: |
| cpufreq_policy_put_kobj(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_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); |
| |
| freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MAX, |
| &policy->nb_max); |
| freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN, |
| &policy->nb_min); |
| |
| /* Cancel any pending policy->update work before freeing the policy. */ |
| cancel_work_sync(&policy->update); |
| |
| if (policy->max_freq_req) { |
| /* |
| * CPUFREQ_CREATE_POLICY notification is sent only after |
| * successfully adding max_freq_req request. |
| */ |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_REMOVE_POLICY, policy); |
| freq_qos_remove_request(policy->max_freq_req); |
| } |
| |
| freq_qos_remove_request(policy->min_freq_req); |
| kfree(policy->min_freq_req); |
| |
| 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; |
| } |
| |
| if (!new_policy && cpufreq_driver->online) { |
| ret = cpufreq_driver->online(policy); |
| if (ret) { |
| pr_debug("%s: %d: initialization failed\n", __func__, |
| __LINE__); |
| goto out_exit_policy; |
| } |
| |
| /* Recover policy->cpus using related_cpus */ |
| cpumask_copy(policy->cpus, policy->related_cpus); |
| } else { |
| 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("%s: %d: initialization failed\n", __func__, |
| __LINE__); |
| goto out_free_policy; |
| } |
| |
| ret = cpufreq_table_validate_and_sort(policy); |
| if (ret) |
| goto out_exit_policy; |
| |
| /* related_cpus should at least include policy->cpus. */ |
| cpumask_copy(policy->related_cpus, policy->cpus); |
| } |
| |
| down_write(&policy->rwsem); |
| /* |
| * 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) { |
| for_each_cpu(j, policy->related_cpus) { |
| per_cpu(cpufreq_cpu_data, j) = policy; |
| add_cpu_dev_symlink(policy, j); |
| } |
| |
| policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req), |
| GFP_KERNEL); |
| if (!policy->min_freq_req) { |
| ret = -ENOMEM; |
| goto out_destroy_policy; |
| } |
| |
| ret = freq_qos_add_request(&policy->constraints, |
| policy->min_freq_req, FREQ_QOS_MIN, |
| policy->min); |
| if (ret < 0) { |
| /* |
| * So we don't call freq_qos_remove_request() for an |
| * uninitialized request. |
| */ |
| kfree(policy->min_freq_req); |
| policy->min_freq_req = NULL; |
| goto out_destroy_policy; |
| } |
| |
| /* |
| * This must be initialized right here to avoid calling |
| * freq_qos_remove_request() on uninitialized request in case |
| * of errors. |
| */ |
| policy->max_freq_req = policy->min_freq_req + 1; |
| |
| ret = freq_qos_add_request(&policy->constraints, |
| policy->max_freq_req, FREQ_QOS_MAX, |
| policy->max); |
| if (ret < 0) { |
| policy->max_freq_req = NULL; |
| goto out_destroy_policy; |
| } |
| |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_CREATE_POLICY, policy); |
| } |
| |
| if (cpufreq_driver->get && has_target()) { |
| policy->cur = cpufreq_driver->get(policy->cpu); |
| if (!policy->cur) { |
| ret = -EIO; |
| pr_err("%s: ->get() failed\n", __func__); |
| goto out_destroy_policy; |
| } |
| } |
| |
| /* |
| * Sometimes boot loaders set CPU frequency to a value outside of |
| * frequency table present with cpufreq core. In such cases CPU might be |
| * unstable if it has to run on that frequency for long duration of time |
| * and so its better to set it to a frequency which is specified in |
| * freq-table. This also makes cpufreq stats inconsistent as |
| * cpufreq-stats would fail to register because current frequency of CPU |
| * isn't found in freq-table. |
| * |
| * Because we don't want this change to effect boot process badly, we go |
| * for the next freq which is >= policy->cur ('cur' must be set by now, |
| * otherwise we will end up setting freq to lowest of the table as 'cur' |
| * is initialized to zero). |
| * |
| * We are passing target-freq as "policy->cur - 1" otherwise |
| * __cpufreq_driver_target() would simply fail, as policy->cur will be |
| * equal to target-freq. |
| */ |
| if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) |
| && has_target()) { |
| unsigned int old_freq = policy->cur; |
| |
| /* Are we running at unknown frequency ? */ |
| ret = cpufreq_frequency_table_get_index(policy, old_freq); |
| if (ret == -EINVAL) { |
| ret = __cpufreq_driver_target(policy, old_freq - 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_info("%s: CPU%d: Running at unlisted initial frequency: %u KHz, changing to: %u KHz\n", |
| __func__, policy->cpu, old_freq, policy->cur); |
| } |
| } |
| |
| if (new_policy) { |
| ret = cpufreq_add_dev_interface(policy); |
| if (ret) |
| goto out_destroy_policy; |
| |
| cpufreq_stats_create_table(policy); |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| list_add(&policy->policy_list, &cpufreq_policy_list); |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| } |
| |
| ret = cpufreq_init_policy(policy); |
| if (ret) { |
| pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n", |
| __func__, cpu, ret); |
| goto out_destroy_policy; |
| } |
| |
| up_write(&policy->rwsem); |
| |
| kobject_uevent(&policy->kobj, KOBJ_ADD); |
| |
| /* Callback for handling stuff after policy is ready */ |
| if (cpufreq_driver->ready) |
| cpufreq_driver->ready(policy); |
| |
| if (cpufreq_thermal_control_enabled(cpufreq_driver)) |
| policy->cdev = of_cpufreq_cooling_register(policy); |
| |
| pr_debug("initialization complete\n"); |
| |
| return 0; |
| |
| out_destroy_policy: |
| for_each_cpu(j, policy->real_cpus) |
| remove_cpu_dev_symlink(policy, get_cpu_device(j)); |
| |
| up_write(&policy->rwsem); |
| |
| out_exit_policy: |
| if (cpufreq_driver->exit) |
| cpufreq_driver->exit(policy); |
| |
| out_free_policy: |
| cpufreq_policy_free(policy); |
| return ret; |
| } |
| |
| /** |
| * cpufreq_add_dev - the cpufreq interface for a CPU device. |
| * @dev: CPU device. |
| * @sif: Subsystem interface structure pointer (not used) |
| */ |
| static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
| { |
| struct cpufreq_policy *policy; |
| unsigned cpu = dev->id; |
| int ret; |
| |
| dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu); |
| |
| if (cpu_online(cpu)) { |
| ret = cpufreq_online(cpu); |
| if (ret) |
| return ret; |
| } |
| |
| /* Create sysfs link on CPU registration */ |
| policy = per_cpu(cpufreq_cpu_data, cpu); |
| if (policy) |
| add_cpu_dev_symlink(policy, cpu); |
| |
| return 0; |
| } |
| |
| static int cpufreq_offline(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy; |
| int ret; |
| |
| pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
| |
| policy = cpufreq_cpu_get_raw(cpu); |
| if (!policy) { |
| pr_debug("%s: No cpu_data found\n", __func__); |
| return 0; |
| } |
| |
| down_write(&policy->rwsem); |
| if (has_target()) |
| cpufreq_stop_governor(policy); |
| |
| cpumask_clear_cpu(cpu, policy->cpus); |
| |
| if (policy_is_inactive(policy)) { |
| if (has_target()) |
| strncpy(policy->last_governor, policy->governor->name, |
| CPUFREQ_NAME_LEN); |
| else |
| policy->last_policy = policy->policy; |
| } else if (cpu == policy->cpu) { |
| /* Nominate new CPU */ |
| policy->cpu = cpumask_any(policy->cpus); |
| } |
| |
| /* Start governor again for active policy */ |
| if (!policy_is_inactive(policy)) { |
| if (has_target()) { |
| ret = cpufreq_start_governor(policy); |
| if (ret) |
| pr_err("%s: Failed to start governor\n", __func__); |
| } |
| |
| goto unlock; |
| } |
| |
| if (cpufreq_thermal_control_enabled(cpufreq_driver)) { |
| cpufreq_cooling_unregister(policy->cdev); |
| policy->cdev = NULL; |
| } |
| |
| if (cpufreq_driver->stop_cpu) |
| cpufreq_driver->stop_cpu(policy); |
| |
| if (has_target()) |
| cpufreq_exit_governor(policy); |
| |
| /* |
| * Perform the ->offline() during light-weight tear-down, as |
| * that allows fast recovery when the CPU comes back. |
| */ |
| if (cpufreq_driver->offline) { |
| cpufreq_driver->offline(policy); |
| } else 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)) { |
| /* We did light-weight exit earlier, do full tear down now */ |
| if (cpufreq_driver->offline) |
| cpufreq_driver->exit(policy); |
| |
| cpufreq_policy_free(policy); |
| } |
| } |
| |
| /** |
| * cpufreq_out_of_sync - Fix up actual and saved CPU frequency difference. |
| * @policy: Policy managing CPUs. |
| * @new_freq: New CPU frequency. |
| * |
| * Adjust to the current frequency first and clean up later by either calling |
| * cpufreq_update_policy(), or scheduling 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); |
| } |
| |
| static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update) |
| { |
| unsigned int new_freq; |
| |
| new_freq = cpufreq_driver->get(policy->cpu); |
| if (!new_freq) |
| return 0; |
| |
| /* |
| * If fast frequency switching is used with the given policy, the check |
| * against policy->cur is pointless, so skip it in that case. |
| */ |
| if (policy->fast_switch_enabled || !has_target()) |
| return new_freq; |
| |
| if (policy->cur != new_freq) { |
| cpufreq_out_of_sync(policy, new_freq); |
| if (update) |
| schedule_work(&policy->update); |
| } |
| |
| return new_freq; |
| } |
| |
| /** |
| * 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); |
| |
| /** |
| * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU |
| * @cpu: CPU number |
| * |
| * The default return value is the max_freq field of cpuinfo. |
| */ |
| __weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
| unsigned int ret_freq = 0; |
| |
| if (policy) { |
| ret_freq = policy->cpuinfo.max_freq; |
| cpufreq_cpu_put(policy); |
| } |
| |
| return ret_freq; |
| } |
| EXPORT_SYMBOL(cpufreq_get_hw_max_freq); |
| |
| static unsigned int __cpufreq_get(struct cpufreq_policy *policy) |
| { |
| if (unlikely(policy_is_inactive(policy))) |
| return 0; |
| |
| return cpufreq_verify_current_freq(policy, true); |
| } |
| |
| /** |
| * 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 (cpufreq_driver->get) |
| ret_freq = __cpufreq_get(policy); |
| up_read(&policy->rwsem); |
| |
| cpufreq_cpu_put(policy); |
| } |
| |
| 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, |
| }; |
| |
| /* |
| * 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: %s\n", __func__, |
| cpufreq_driver->name); |
| } |
| |
| suspend: |
| cpufreq_suspended = true; |
| } |
| |
| /** |
| * cpufreq_resume() - Resume CPUFreq governors. |
| * |
| * Called during system wide Suspend/Hibernate cycle for resuming governors that |
| * are suspended with cpufreq_suspend(). |
| */ |
| void cpufreq_resume(void) |
| { |
| struct cpufreq_policy *policy; |
| int ret; |
| |
| if (!cpufreq_driver) |
| return; |
| |
| if (unlikely(!cpufreq_suspended)) |
| return; |
| |
| cpufreq_suspended = false; |
| |
| if (!has_target() && !cpufreq_driver->resume) |
| return; |
| |
| pr_debug("%s: Resuming Governors\n", __func__); |
| |
| for_each_active_policy(policy) { |
| if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) { |
| pr_err("%s: Failed to resume driver: %p\n", __func__, |
| policy); |
| } else if (has_target()) { |
| down_write(&policy->rwsem); |
| ret = cpufreq_start_governor(policy); |
| up_write(&policy->rwsem); |
| |
| if (ret) |
| pr_err("%s: Failed to start governor for policy: %p\n", |
| __func__, policy); |
| } |
| } |
| } |
| |
| /** |
| * cpufreq_driver_test_flags - Test cpufreq driver's flags against given ones. |
| * @flags: Flags to test against the current cpufreq driver's flags. |
| * |
| * Assumes that the driver is there, so callers must ensure that this is the |
| * case. |
| */ |
| bool cpufreq_driver_test_flags(u16 flags) |
| { |
| return !!(cpufreq_driver->flags & flags); |
| } |
| |
| /** |
| * cpufreq_get_current_driver - Return the current driver's name. |
| * |
| * Return the name string of the currently registered 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 registered cpufreq driver, or NULL |
| * if no cpufreq driver has been registered. |
| */ |
| 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 notifier with cpufreq. |
| * @nb: notifier function to register. |
| * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER. |
| * |
| * Add a notifier to one of two lists: either a list of notifiers that run on |
| * clock rate changes (once before and once after every transition), or a list |
| * of notifiers that ron on cpufreq policy changes. |
| * |
| * This function may sleep and it has the same return values as |
| * blocking_notifier_chain_register(). |
| */ |
| int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) |
| { |
| int ret; |
| |
| if (cpufreq_disabled()) |
| return -EINVAL; |
| |
| switch (list) { |
| case CPUFREQ_TRANSITION_NOTIFIER: |
| mutex_lock(&cpufreq_fast_switch_lock); |
| |
| if (cpufreq_fast_switch_count > 0) { |
| mutex_unlock(&cpufreq_fast_switch_lock); |
| return -EBUSY; |
| } |
| ret = srcu_notifier_chain_register( |
| &cpufreq_transition_notifier_list, nb); |
| if (!ret) |
| cpufreq_fast_switch_count--; |
| |
| mutex_unlock(&cpufreq_fast_switch_lock); |
| break; |
| case CPUFREQ_POLICY_NOTIFIER: |
| ret = blocking_notifier_chain_register( |
| &cpufreq_policy_notifier_list, nb); |
| break; |
| default: |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(cpufreq_register_notifier); |
| |
| /** |
| * cpufreq_unregister_notifier - Unregister a notifier from cpufreq. |
| * @nb: notifier block to be unregistered. |
| * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER. |
| * |
| * Remove a notifier from one of the cpufreq notifier lists. |
| * |
| * This function may sleep and it has the same return values 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) |
| { |
| unsigned int freq; |
| int cpu; |
| |
| target_freq = clamp_val(target_freq, policy->min, policy->max); |
| freq = cpufreq_driver->fast_switch(policy, target_freq); |
| |
| if (!freq) |
| return 0; |
| |
| policy->cur = freq; |
| arch_set_freq_scale(policy->related_cpus, freq, |
| policy->cpuinfo.max_freq); |
| cpufreq_stats_record_transition(policy, freq); |
| |
| if (trace_cpu_frequency_enabled()) { |
| for_each_cpu(cpu, policy->cpus) |
| trace_cpu_frequency(freq, cpu); |
| } |
| |
| return freq; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); |
| |
| /** |
| * cpufreq_driver_adjust_perf - Adjust CPU performance level in one go. |
| * @cpu: Target CPU. |
| * @min_perf: Minimum (required) performance level (units of @capacity). |
| * @target_perf: Target (desired) performance level (units of @capacity). |
| * @capacity: Capacity of the target CPU. |
| * |
| * Carry out a fast performance level switch of @cpu without sleeping. |
| * |
| * The driver's ->adjust_perf() 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 a suitable performance level equal to or above |
| * @min_perf and preferably equal to or below @target_perf. |
| * |
| * 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 CPU and that it will never be called in |
| * parallel with either ->target() or ->target_index() or ->fast_switch() for |
| * the same CPU. |
| */ |
| void cpufreq_driver_adjust_perf(unsigned int cpu, |
| unsigned long min_perf, |
| unsigned long target_perf, |
| unsigned long capacity) |
| { |
| cpufreq_driver->adjust_perf(cpu, min_perf, target_perf, capacity); |
| } |
| |
| /** |
| * cpufreq_driver_has_adjust_perf - Check "direct fast switch" callback. |
| * |
| * Return 'true' if the ->adjust_perf callback is present for the |
| * current driver or 'false' otherwise. |
| */ |
| bool cpufreq_driver_has_adjust_perf(void) |
| { |
| return !!cpufreq_driver->adjust_perf; |
| } |
| |
| /* 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 restore_freq, intermediate_freq = 0; |
| unsigned int newfreq = policy->freq_table[index].frequency; |
| int retval = -EINVAL; |
| bool notify; |
| |
| if (newfreq == policy->cur) |
| return 0; |
| |
| /* Save last value to restore later on errors */ |
| restore_freq = policy->cur; |
| |
| 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 = 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 && |
| !(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS)) |
| return 0; |
| |
| 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; |
| |
| 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->flags & CPUFREQ_GOV_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; |
| } |
| } |
| |
| policy->strict_target = !!(policy->governor->flags & CPUFREQ_GOV_STRICT_TARGET); |
| |
| 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); |
| } |
| |
| 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_verify_current_freq(policy, false); |
| |
| if (policy->governor->start) { |
| ret = policy->governor->start(policy); |
| if (ret) |
| return ret; |
| } |
| |
| if (policy->governor->limits) |
| policy->governor->limits(policy); |
| |
| return 0; |
| } |
| |
| void cpufreq_stop_governor(struct cpufreq_policy *policy) |
| { |
| if (cpufreq_suspended || !policy->governor) |
| return; |
| |
| pr_debug("%s: for CPU %u\n", __func__, policy->cpu); |
| |
| if (policy->governor->stop) |
| policy->governor->stop(policy); |
| } |
| |
| static void cpufreq_governor_limits(struct cpufreq_policy *policy) |
| { |
| if (cpufreq_suspended || !policy->governor) |
| return; |
| |
| pr_debug("%s: for CPU %u\n", __func__, policy->cpu); |
| |
| if (policy->governor->limits) |
| policy->governor->limits(policy); |
| } |
| |
| int cpufreq_register_governor(struct cpufreq_governor *governor) |
| { |
| int err; |
| |
| if (!governor) |
| return -EINVAL; |
| |
| if (cpufreq_disabled()) |
| return -ENODEV; |
| |
| mutex_lock(&cpufreq_governor_mutex); |
| |
| err = -EBUSY; |
| if (!find_governor(governor->name)) { |
| err = 0; |
| list_add(&governor->governor_list, &cpufreq_governor_list); |
| } |
| |
| mutex_unlock(&cpufreq_governor_mutex); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_register_governor); |
| |
| void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
| { |
| struct cpufreq_policy *policy; |
| unsigned long flags; |
| |
| if (!governor) |
| return; |
| |
| if (cpufreq_disabled()) |
| return; |
| |
| /* clear last_governor for all inactive policies */ |
| read_lock_irqsave(&cpufreq_driver_lock, flags); |
| for_each_inactive_policy(policy) { |
| if (!strcmp(policy->last_governor, governor->name)) { |
| policy->governor = NULL; |
| strcpy(policy->last_governor, "\0"); |
| } |
| } |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| mutex_lock(&cpufreq_governor_mutex); |
| list_del(&governor->governor_list); |
| mutex_unlock(&cpufreq_governor_mutex); |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); |
| |
| |
| /********************************************************************* |
| * POLICY INTERFACE * |
| *********************************************************************/ |
| |
| /** |
| * cpufreq_get_policy - get the current cpufreq_policy |
| * @policy: struct cpufreq_policy into which the current cpufreq_policy |
| * is written |
| * @cpu: CPU to find the policy for |
| * |
| * 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); |
| |
| /** |
| * cpufreq_set_policy - Modify cpufreq policy parameters. |
| * @policy: Policy object to modify. |
| * @new_gov: Policy governor pointer. |
| * @new_pol: Policy value (for drivers with built-in governors). |
| * |
| * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency |
| * limits to be set for the policy, update @policy with the verified limits |
| * values and either invoke the driver's ->setpolicy() callback (if present) or |
| * carry out a governor update for @policy. That is, run the current governor's |
| * ->limits() callback (if @new_gov points to the same object as the one in |
| * @policy) or replace the governor for @policy with @new_gov. |
| * |
| * The cpuinfo part of @policy is not updated by this function. |
| */ |
| static int cpufreq_set_policy(struct cpufreq_policy *policy, |
| struct cpufreq_governor *new_gov, |
| unsigned int new_pol) |
| { |
| struct cpufreq_policy_data new_data; |
| struct cpufreq_governor *old_gov; |
| int ret; |
| |
| memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
| new_data.freq_table = policy->freq_table; |
| new_data.cpu = policy->cpu; |
| /* |
| * PM QoS framework collects all the requests from users and provide us |
| * the final aggregated value here. |
| */ |
| new_data.min = freq_qos_read_value(&policy->constraints, FREQ_QOS_MIN); |
| new_data.max = freq_qos_read_value(&policy->constraints, FREQ_QOS_MAX); |
| |
| pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
| new_data.cpu, new_data.min, new_data.max); |
| |
| /* |
| * Verify that the CPU speed can be set within these limits and make sure |
| * that min <= max. |
| */ |
| ret = cpufreq_driver->verify(&new_data); |
| if (ret) |
| return ret; |
| |
| policy->min = new_data.min; |
| policy->max = new_data.max; |
| trace_cpu_frequency_limits(policy); |
| |
| policy->cached_target_freq = UINT_MAX; |
| |
| pr_debug("new min and max freqs are %u - %u kHz\n", |
| policy->min, policy->max); |
| |
| if (cpufreq_driver->setpolicy) { |
| policy->policy = new_pol; |
| pr_debug("setting range\n"); |
| return cpufreq_driver->setpolicy(policy); |
| } |
| |
| if (new_gov == policy->governor) { |
| pr_debug("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_gov; |
| ret = cpufreq_init_governor(policy); |
| if (!ret) { |
| ret = cpufreq_start_governor(policy); |
| if (!ret) { |
| pr_debug("governor change\n"); |
| sched_cpufreq_governor_change(policy, old_gov); |
| 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 to re-evaluate the policy for. |
| * |
| * Update the current frequency for the cpufreq policy of @cpu and use |
| * cpufreq_set_policy() to re-apply the min and max limits, which triggers the |
| * evaluation of policy notifiers and the cpufreq driver's ->verify() callback |
| * for the policy in question, among other things. |
| */ |
| void cpufreq_update_policy(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu); |
| |
| if (!policy) |
| return; |
| |
| /* |
| * BIOS might change freq behind our back |
| * -> ask driver for current freq and notify governors about a change |
| */ |
| if (cpufreq_driver->get && has_target() && |
| (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false)))) |
| goto unlock; |
| |
| refresh_frequency_limits(policy); |
| |
| unlock: |
| cpufreq_cpu_release(policy); |
| } |
| EXPORT_SYMBOL(cpufreq_update_policy); |
| |
| /** |
| * cpufreq_update_limits - Update policy limits for a given CPU. |
| * @cpu: CPU to update the policy limits for. |
| * |
| * Invoke the driver's ->update_limits callback if present or call |
| * cpufreq_update_policy() for @cpu. |
| */ |
| void cpufreq_update_limits(unsigned int cpu) |
| { |
| if (cpufreq_driver->update_limits) |
| cpufreq_driver->update_limits(cpu); |
| else |
| cpufreq_update_policy(cpu); |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_update_limits); |
| |
| /********************************************************************* |
| * BOOST * |
| *********************************************************************/ |
| static int cpufreq_boost_set_sw(struct cpufreq_policy *policy, int state) |
| { |
| int ret; |
| |
| if (!policy->freq_table) |
| return -ENXIO; |
| |
| ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table); |
| if (ret) { |
| pr_err("%s: Policy frequency update failed\n", __func__); |
| return ret; |
| } |
| |
| ret = freq_qos_update_request(policy->max_freq_req, policy->max); |
| if (ret < 0) |
| return ret; |
| |
| return 0; |
| } |
| |
| int cpufreq_boost_trigger_state(int state) |
| { |
| struct cpufreq_policy *policy; |
| 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); |
| |
| get_online_cpus(); |
| for_each_active_policy(policy) { |
| ret = cpufreq_driver->set_boost(policy, state); |
| if (ret) |
| goto err_reset_state; |
| } |
| put_online_cpus(); |
| |
| return 0; |
| |
| err_reset_state: |
| put_online_cpus(); |
| |
| 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 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; |
| |
| /* |
| * The cpufreq core depends heavily on the availability of device |
| * structure, make sure they are available before proceeding further. |
| */ |
| if (!get_cpu_device(0)) |
| return -EPROBE_DEFER; |
| |
| 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) || |
| (!driver_data->online != !driver_data->offline)) |
| 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); |
| |
| /* |
| * Mark support for the scheduler's frequency invariance engine for |
| * drivers that implement target(), target_index() or fast_switch(). |
| */ |
| if (!cpufreq_driver->setpolicy) { |
| static_branch_enable_cpuslocked(&cpufreq_freq_invariance); |
| pr_debug("supports frequency invariance"); |
| } |
| |
| 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 (unlikely(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(); |
| static_branch_disable_cpuslocked(&cpufreq_freq_invariance); |
| 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); |
| |
| static int __init cpufreq_core_init(void) |
| { |
| struct cpufreq_governor *gov = cpufreq_default_governor(); |
| |
| if (cpufreq_disabled()) |
| return -ENODEV; |
| |
| cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
| BUG_ON(!cpufreq_global_kobject); |
| |
| if (!strlen(default_governor)) |
| strncpy(default_governor, gov->name, CPUFREQ_NAME_LEN); |
| |
| return 0; |
| } |
| module_param(off, int, 0444); |
| module_param_string(default_governor, default_governor, CPUFREQ_NAME_LEN, 0444); |
| core_initcall(cpufreq_core_init); |