| /* |
| * 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> |
| |
| /** |
| * 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_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback); |
| static DEFINE_RWLOCK(cpufreq_driver_lock); |
| DEFINE_MUTEX(cpufreq_governor_lock); |
| static LIST_HEAD(cpufreq_policy_list); |
| |
| /* This one keeps track of the previously set governor of a removed CPU */ |
| static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
| |
| /* Flag to suspend/resume CPUFreq governors */ |
| static bool cpufreq_suspended; |
| |
| static inline bool has_target(void) |
| { |
| return cpufreq_driver->target_index || cpufreq_driver->target; |
| } |
| |
| /* |
| * rwsem to guarantee that cpufreq driver module doesn't unload during critical |
| * sections |
| */ |
| static DECLARE_RWSEM(cpufreq_rwsem); |
| |
| /* internal prototypes */ |
| static int __cpufreq_governor(struct cpufreq_policy *policy, |
| unsigned int event); |
| static unsigned int __cpufreq_get(struct cpufreq_policy *policy); |
| static void handle_update(struct work_struct *work); |
| |
| /** |
| * 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 LIST_HEAD(cpufreq_governor_list); |
| 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_cputime64(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 = cputime_to_usecs(cur_wall_time); |
| |
| return cputime_to_usecs(idle_time); |
| } |
| |
| 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 |
| */ |
| 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 configuartion where all processors |
| * share the clock and voltage and clock. |
| */ |
| cpumask_setall(policy->cpus); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_generic_init); |
| |
| unsigned int cpufreq_generic_get(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, 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); |
| |
| /* Only for cpufreq core internal use */ |
| struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) |
| { |
| return per_cpu(cpufreq_cpu_data, cpu); |
| } |
| |
| struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy = NULL; |
| unsigned long flags; |
| |
| if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) |
| return NULL; |
| |
| if (!down_read_trylock(&cpufreq_rwsem)) |
| return NULL; |
| |
| /* get the cpufreq driver */ |
| read_lock_irqsave(&cpufreq_driver_lock, flags); |
| |
| if (cpufreq_driver) { |
| /* get the CPU */ |
| policy = per_cpu(cpufreq_cpu_data, cpu); |
| if (policy) |
| kobject_get(&policy->kobj); |
| } |
| |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| if (!policy) |
| up_read(&cpufreq_rwsem); |
| |
| return policy; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
| |
| void cpufreq_cpu_put(struct cpufreq_policy *policy) |
| { |
| if (cpufreq_disabled()) |
| return; |
| |
| kobject_put(&policy->kobj); |
| up_read(&cpufreq_rwsem); |
| } |
| 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); |
| 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); |
| |
| |
| /********************************************************************* |
| * 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; |
| |
| list_for_each_entry(t, &cpufreq_governor_list, governor_list) |
| 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) |
| goto out; |
| |
| 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); |
| } |
| out: |
| 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); |
| |
| static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) |
| { |
| ssize_t ret; |
| |
| 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; \ |
| \ |
| ret = cpufreq_get_policy(&new_policy, policy->cpu); \ |
| if (ret) \ |
| return -EINVAL; \ |
| \ |
| 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, "<unknown>"); |
| return sprintf(buf, "%u\n", cur_freq); |
| } |
| |
| /** |
| * 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; |
| |
| ret = cpufreq_get_policy(&new_policy, policy->cpu); |
| if (ret) |
| return ret; |
| |
| 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); |
| |
| policy->user_policy.policy = policy->policy; |
| policy->user_policy.governor = policy->governor; |
| |
| if (ret) |
| return ret; |
| else |
| return 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; |
| } |
| |
| list_for_each_entry(t, &cpufreq_governor_list, governor_list) { |
| if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
| - (CPUFREQ_NAME_LEN + 2))) |
| goto out; |
| i += scnprintf(&buf[i], CPUFREQ_NAME_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; |
| |
| if (!down_read_trylock(&cpufreq_rwsem)) |
| return -EINVAL; |
| |
| down_read(&policy->rwsem); |
| |
| if (fattr->show) |
| ret = fattr->show(policy, buf); |
| else |
| ret = -EIO; |
| |
| up_read(&policy->rwsem); |
| up_read(&cpufreq_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; |
| |
| get_online_cpus(); |
| |
| if (!cpu_online(policy->cpu)) |
| goto unlock; |
| |
| if (!down_read_trylock(&cpufreq_rwsem)) |
| goto unlock; |
| |
| down_write(&policy->rwsem); |
| |
| if (fattr->store) |
| ret = fattr->store(policy, buf, count); |
| else |
| ret = -EIO; |
| |
| up_write(&policy->rwsem); |
| |
| up_read(&cpufreq_rwsem); |
| unlock: |
| put_online_cpus(); |
| |
| 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, |
| }; |
| |
| struct kobject *cpufreq_global_kobject; |
| EXPORT_SYMBOL(cpufreq_global_kobject); |
| |
| static int cpufreq_global_kobject_usage; |
| |
| int cpufreq_get_global_kobject(void) |
| { |
| if (!cpufreq_global_kobject_usage++) |
| return kobject_add(cpufreq_global_kobject, |
| &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(cpufreq_get_global_kobject); |
| |
| void cpufreq_put_global_kobject(void) |
| { |
| if (!--cpufreq_global_kobject_usage) |
| kobject_del(cpufreq_global_kobject); |
| } |
| EXPORT_SYMBOL(cpufreq_put_global_kobject); |
| |
| int cpufreq_sysfs_create_file(const struct attribute *attr) |
| { |
| int ret = cpufreq_get_global_kobject(); |
| |
| if (!ret) { |
| ret = sysfs_create_file(cpufreq_global_kobject, attr); |
| if (ret) |
| cpufreq_put_global_kobject(); |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(cpufreq_sysfs_create_file); |
| |
| void cpufreq_sysfs_remove_file(const struct attribute *attr) |
| { |
| sysfs_remove_file(cpufreq_global_kobject, attr); |
| cpufreq_put_global_kobject(); |
| } |
| EXPORT_SYMBOL(cpufreq_sysfs_remove_file); |
| |
| /* symlink affected CPUs */ |
| static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
| { |
| unsigned int j; |
| int ret = 0; |
| |
| for_each_cpu(j, policy->cpus) { |
| struct device *cpu_dev; |
| |
| if (j == policy->cpu) |
| continue; |
| |
| pr_debug("Adding link for CPU: %u\n", j); |
| cpu_dev = get_cpu_device(j); |
| ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
| "cpufreq"); |
| if (ret) |
| break; |
| } |
| return ret; |
| } |
| |
| static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
| struct device *dev) |
| { |
| 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 cpufreq_add_dev_symlink(policy); |
| } |
| |
| static void cpufreq_init_policy(struct cpufreq_policy *policy) |
| { |
| struct cpufreq_governor *gov = NULL; |
| struct cpufreq_policy new_policy; |
| int ret = 0; |
| |
| memcpy(&new_policy, policy, sizeof(*policy)); |
| |
| /* Update governor of new_policy to the governor used before hotplug */ |
| gov = find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu)); |
| if (gov) |
| pr_debug("Restoring governor %s for cpu %d\n", |
| policy->governor->name, policy->cpu); |
| else |
| gov = CPUFREQ_DEFAULT_GOVERNOR; |
| |
| new_policy.governor = gov; |
| |
| /* Use the default policy if its valid. */ |
| if (cpufreq_driver->setpolicy) |
| cpufreq_parse_governor(gov->name, &new_policy.policy, NULL); |
| |
| /* set default policy */ |
| ret = cpufreq_set_policy(policy, &new_policy); |
| if (ret) { |
| pr_debug("setting policy failed\n"); |
| if (cpufreq_driver->exit) |
| cpufreq_driver->exit(policy); |
| } |
| } |
| |
| static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
| unsigned int cpu, struct device *dev) |
| { |
| int ret = 0; |
| unsigned long flags; |
| |
| if (has_target()) { |
| ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
| if (ret) { |
| pr_err("%s: Failed to stop governor\n", __func__); |
| return ret; |
| } |
| } |
| |
| down_write(&policy->rwsem); |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| |
| cpumask_set_cpu(cpu, policy->cpus); |
| per_cpu(cpufreq_cpu_data, cpu) = policy; |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| up_write(&policy->rwsem); |
| |
| if (has_target()) { |
| ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); |
| if (!ret) |
| ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
| |
| if (ret) { |
| pr_err("%s: Failed to start governor\n", __func__); |
| return ret; |
| } |
| } |
| |
| return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
| } |
| |
| static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy; |
| unsigned long flags; |
| |
| read_lock_irqsave(&cpufreq_driver_lock, flags); |
| |
| policy = per_cpu(cpufreq_cpu_data_fallback, cpu); |
| |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| if (policy) |
| policy->governor = NULL; |
| |
| return policy; |
| } |
| |
| static struct cpufreq_policy *cpufreq_policy_alloc(void) |
| { |
| struct cpufreq_policy *policy; |
| |
| 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; |
| |
| INIT_LIST_HEAD(&policy->policy_list); |
| init_rwsem(&policy->rwsem); |
| spin_lock_init(&policy->transition_lock); |
| init_waitqueue_head(&policy->transition_wait); |
| |
| return policy; |
| |
| 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; |
| |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_REMOVE_POLICY, policy); |
| |
| down_read(&policy->rwsem); |
| kobj = &policy->kobj; |
| cmp = &policy->kobj_unregister; |
| up_read(&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) |
| { |
| free_cpumask_var(policy->related_cpus); |
| free_cpumask_var(policy->cpus); |
| kfree(policy); |
| } |
| |
| static int update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu, |
| struct device *cpu_dev) |
| { |
| int ret; |
| |
| if (WARN_ON(cpu == policy->cpu)) |
| return 0; |
| |
| /* Move kobject to the new policy->cpu */ |
| ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
| if (ret) { |
| pr_err("%s: Failed to move kobj: %d\n", __func__, ret); |
| return ret; |
| } |
| |
| down_write(&policy->rwsem); |
| |
| policy->last_cpu = policy->cpu; |
| policy->cpu = cpu; |
| |
| up_write(&policy->rwsem); |
| |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_UPDATE_POLICY_CPU, policy); |
| |
| return 0; |
| } |
| |
| static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
| { |
| unsigned int j, cpu = dev->id; |
| int ret = -ENOMEM; |
| struct cpufreq_policy *policy; |
| unsigned long flags; |
| bool recover_policy = cpufreq_suspended; |
| |
| if (cpu_is_offline(cpu)) |
| return 0; |
| |
| pr_debug("adding CPU %u\n", cpu); |
| |
| /* check whether a different CPU already registered this |
| * CPU because it is in the same boat. */ |
| policy = cpufreq_cpu_get_raw(cpu); |
| if (unlikely(policy)) |
| return 0; |
| |
| if (!down_read_trylock(&cpufreq_rwsem)) |
| return 0; |
| |
| /* Check if this cpu was hot-unplugged earlier and has siblings */ |
| read_lock_irqsave(&cpufreq_driver_lock, flags); |
| list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { |
| if (cpumask_test_cpu(cpu, policy->related_cpus)) { |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| ret = cpufreq_add_policy_cpu(policy, cpu, dev); |
| up_read(&cpufreq_rwsem); |
| return ret; |
| } |
| } |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| /* |
| * Restore the saved policy when doing light-weight init and fall back |
| * to the full init if that fails. |
| */ |
| policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL; |
| if (!policy) { |
| recover_policy = false; |
| policy = cpufreq_policy_alloc(); |
| if (!policy) |
| goto nomem_out; |
| } |
| |
| /* |
| * In the resume path, since we restore a saved policy, the assignment |
| * to policy->cpu is like an update of the existing policy, rather than |
| * the creation of a brand new one. So we need to perform this update |
| * by invoking update_policy_cpu(). |
| */ |
| if (recover_policy && cpu != policy->cpu) |
| WARN_ON(update_policy_cpu(policy, cpu, dev)); |
| else |
| policy->cpu = cpu; |
| |
| cpumask_copy(policy->cpus, cpumask_of(cpu)); |
| |
| init_completion(&policy->kobj_unregister); |
| INIT_WORK(&policy->update, handle_update); |
| |
| /* call driver. From then on the cpufreq must be able |
| * to accept all calls to ->verify and ->setpolicy for this CPU |
| */ |
| ret = cpufreq_driver->init(policy); |
| if (ret) { |
| pr_debug("initialization failed\n"); |
| goto err_set_policy_cpu; |
| } |
| |
| down_write(&policy->rwsem); |
| |
| /* related cpus should atleast have policy->cpus */ |
| cpumask_or(policy->related_cpus, 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 (!recover_policy) { |
| policy->user_policy.min = policy->min; |
| policy->user_policy.max = policy->max; |
| |
| /* prepare interface data */ |
| ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, |
| &dev->kobj, "cpufreq"); |
| if (ret) { |
| pr_err("%s: failed to init policy->kobj: %d\n", |
| __func__, ret); |
| goto err_init_policy_kobj; |
| } |
| } |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| for_each_cpu(j, policy->cpus) |
| per_cpu(cpufreq_cpu_data, j) = policy; |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| 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 err_get_freq; |
| } |
| } |
| |
| /* |
| * 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); |
| } |
| } |
| |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_START, policy); |
| |
| if (!recover_policy) { |
| ret = cpufreq_add_dev_interface(policy, dev); |
| if (ret) |
| goto err_out_unregister; |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_CREATE_POLICY, policy); |
| } |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| list_add(&policy->policy_list, &cpufreq_policy_list); |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| cpufreq_init_policy(policy); |
| |
| if (!recover_policy) { |
| policy->user_policy.policy = policy->policy; |
| policy->user_policy.governor = policy->governor; |
| } |
| up_write(&policy->rwsem); |
| |
| kobject_uevent(&policy->kobj, KOBJ_ADD); |
| |
| up_read(&cpufreq_rwsem); |
| |
| /* Callback for handling stuff after policy is ready */ |
| if (cpufreq_driver->ready) |
| cpufreq_driver->ready(policy); |
| |
| pr_debug("initialization complete\n"); |
| |
| return 0; |
| |
| err_out_unregister: |
| err_get_freq: |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| for_each_cpu(j, policy->cpus) |
| per_cpu(cpufreq_cpu_data, j) = NULL; |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| if (!recover_policy) { |
| kobject_put(&policy->kobj); |
| wait_for_completion(&policy->kobj_unregister); |
| } |
| err_init_policy_kobj: |
| up_write(&policy->rwsem); |
| |
| if (cpufreq_driver->exit) |
| cpufreq_driver->exit(policy); |
| err_set_policy_cpu: |
| if (recover_policy) { |
| /* Do not leave stale fallback data behind. */ |
| per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL; |
| cpufreq_policy_put_kobj(policy); |
| } |
| cpufreq_policy_free(policy); |
| |
| nomem_out: |
| up_read(&cpufreq_rwsem); |
| |
| return ret; |
| } |
| |
| /** |
| * cpufreq_add_dev - add a CPU device |
| * |
| * Adds the cpufreq interface for a CPU device. |
| * |
| * The Oracle says: try running cpufreq registration/unregistration concurrently |
| * with with cpu hotplugging and all hell will break loose. Tried to clean this |
| * mess up, but more thorough testing is needed. - Mathieu |
| */ |
| static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
| { |
| return __cpufreq_add_dev(dev, sif); |
| } |
| |
| static int __cpufreq_remove_dev_prepare(struct device *dev, |
| struct subsys_interface *sif) |
| { |
| unsigned int cpu = dev->id, cpus; |
| int ret; |
| unsigned long flags; |
| struct cpufreq_policy *policy; |
| |
| pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| |
| policy = per_cpu(cpufreq_cpu_data, cpu); |
| |
| /* Save the policy somewhere when doing a light-weight tear-down */ |
| if (cpufreq_suspended) |
| per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
| |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| if (!policy) { |
| pr_debug("%s: No cpu_data found\n", __func__); |
| return -EINVAL; |
| } |
| |
| if (has_target()) { |
| ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
| if (ret) { |
| pr_err("%s: Failed to stop governor\n", __func__); |
| return ret; |
| } |
| |
| strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
| policy->governor->name, CPUFREQ_NAME_LEN); |
| } |
| |
| down_read(&policy->rwsem); |
| cpus = cpumask_weight(policy->cpus); |
| up_read(&policy->rwsem); |
| |
| if (cpu != policy->cpu) { |
| sysfs_remove_link(&dev->kobj, "cpufreq"); |
| } else if (cpus > 1) { |
| /* Nominate new CPU */ |
| int new_cpu = cpumask_any_but(policy->cpus, cpu); |
| struct device *cpu_dev = get_cpu_device(new_cpu); |
| |
| sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
| ret = update_policy_cpu(policy, new_cpu, cpu_dev); |
| if (ret) { |
| if (sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
| "cpufreq")) |
| pr_err("%s: Failed to restore kobj link to cpu:%d\n", |
| __func__, cpu_dev->id); |
| return ret; |
| } |
| |
| if (!cpufreq_suspended) |
| pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
| __func__, new_cpu, cpu); |
| } else if (cpufreq_driver->stop_cpu) { |
| cpufreq_driver->stop_cpu(policy); |
| } |
| |
| return 0; |
| } |
| |
| static int __cpufreq_remove_dev_finish(struct device *dev, |
| struct subsys_interface *sif) |
| { |
| unsigned int cpu = dev->id, cpus; |
| int ret; |
| unsigned long flags; |
| struct cpufreq_policy *policy; |
| |
| read_lock_irqsave(&cpufreq_driver_lock, flags); |
| policy = per_cpu(cpufreq_cpu_data, cpu); |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| if (!policy) { |
| pr_debug("%s: No cpu_data found\n", __func__); |
| return -EINVAL; |
| } |
| |
| down_write(&policy->rwsem); |
| cpus = cpumask_weight(policy->cpus); |
| |
| if (cpus > 1) |
| cpumask_clear_cpu(cpu, policy->cpus); |
| up_write(&policy->rwsem); |
| |
| /* If cpu is last user of policy, free policy */ |
| if (cpus == 1) { |
| if (has_target()) { |
| ret = __cpufreq_governor(policy, |
| CPUFREQ_GOV_POLICY_EXIT); |
| if (ret) { |
| pr_err("%s: Failed to exit governor\n", |
| __func__); |
| return ret; |
| } |
| } |
| |
| if (!cpufreq_suspended) |
| cpufreq_policy_put_kobj(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); |
| |
| /* Remove policy from list of active policies */ |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| list_del(&policy->policy_list); |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| if (!cpufreq_suspended) |
| cpufreq_policy_free(policy); |
| } else if (has_target()) { |
| ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); |
| if (!ret) |
| ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
| |
| if (ret) { |
| pr_err("%s: Failed to start governor\n", __func__); |
| return ret; |
| } |
| } |
| |
| per_cpu(cpufreq_cpu_data, cpu) = NULL; |
| return 0; |
| } |
| |
| /** |
| * cpufreq_remove_dev - remove a CPU device |
| * |
| * Removes the cpufreq interface for a CPU device. |
| */ |
| static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
| { |
| unsigned int cpu = dev->id; |
| int ret; |
| |
| if (cpu_is_offline(cpu)) |
| return 0; |
| |
| ret = __cpufreq_remove_dev_prepare(dev, sif); |
| |
| if (!ret) |
| ret = __cpufreq_remove_dev_finish(dev, sif); |
| |
| 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); |
| } |
| |
| /** |
| * 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; |
| |
| if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
| return cpufreq_driver->get(cpu); |
| |
| 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); |
| |
| 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); |
| 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_err("%s: suspend_freq can't be zero\n", __func__); |
| return -EINVAL; |
| } |
| |
| 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()) |
| goto suspend; |
| |
| pr_debug("%s: Suspending Governors\n", __func__); |
| |
| list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { |
| if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP)) |
| pr_err("%s: Failed to stop governor for policy: %p\n", |
| __func__, policy); |
| else 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; |
| |
| if (!cpufreq_driver) |
| return; |
| |
| cpufreq_suspended = false; |
| |
| if (!has_target()) |
| return; |
| |
| pr_debug("%s: Resuming Governors\n", __func__); |
| |
| list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { |
| if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) |
| pr_err("%s: Failed to resume driver: %p\n", __func__, |
| policy); |
| else if (__cpufreq_governor(policy, CPUFREQ_GOV_START) |
| || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS)) |
| pr_err("%s: Failed to start governor for policy: %p\n", |
| __func__, policy); |
| |
| /* |
| * schedule call cpufreq_update_policy() for boot CPU, i.e. last |
| * policy in list. It will verify that the current freq is in |
| * sync with what we believe it to be. |
| */ |
| if (list_is_last(&policy->policy_list, &cpufreq_policy_list)) |
| schedule_work(&policy->update); |
| } |
| } |
| |
| /** |
| * 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: |
| ret = srcu_notifier_chain_register( |
| &cpufreq_transition_notifier_list, nb); |
| break; |
| case CPUFREQ_POLICY_NOTIFIER: |
| ret = blocking_notifier_chain_register( |
| &cpufreq_policy_notifier_list, nb); |
| break; |
| default: |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(cpufreq_register_notifier); |
| |
| /** |
| * cpufreq_unregister_notifier - unregister a driver with cpufreq |
| * @nb: notifier block to be unregistered |
| * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
| * |
| * Remove a driver from the CPU frequency notifier list. |
| * |
| * This function may sleep, and has the same return conditions as |
| * blocking_notifier_chain_unregister. |
| */ |
| int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) |
| { |
| int ret; |
| |
| if (cpufreq_disabled()) |
| return -EINVAL; |
| |
| switch (list) { |
| case CPUFREQ_TRANSITION_NOTIFIER: |
| ret = srcu_notifier_chain_unregister( |
| &cpufreq_transition_notifier_list, nb); |
| break; |
| case CPUFREQ_POLICY_NOTIFIER: |
| ret = blocking_notifier_chain_unregister( |
| &cpufreq_policy_notifier_list, nb); |
| break; |
| default: |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(cpufreq_unregister_notifier); |
| |
| |
| /********************************************************************* |
| * GOVERNORS * |
| *********************************************************************/ |
| |
| /* 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, |
| struct cpufreq_frequency_table *freq_table, int index) |
| { |
| struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; |
| unsigned int intermediate_freq = 0; |
| int retval = -EINVAL; |
| bool notify; |
| |
| 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 = freq_table[index].frequency; |
| 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 have'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 retval = -EINVAL; |
| |
| if (cpufreq_disabled()) |
| return -ENODEV; |
| |
| /* Make sure that target_freq is within supported range */ |
| if (target_freq > policy->max) |
| target_freq = policy->max; |
| if (target_freq < policy->min) |
| target_freq = policy->min; |
| |
| 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) |
| retval = cpufreq_driver->target(policy, target_freq, relation); |
| else if (cpufreq_driver->target_index) { |
| struct cpufreq_frequency_table *freq_table; |
| int index; |
| |
| freq_table = cpufreq_frequency_get_table(policy->cpu); |
| if (unlikely(!freq_table)) { |
| pr_err("%s: Unable to find freq_table\n", __func__); |
| goto out; |
| } |
| |
| retval = cpufreq_frequency_table_target(policy, freq_table, |
| target_freq, relation, &index); |
| if (unlikely(retval)) { |
| pr_err("%s: Unable to find matching freq\n", __func__); |
| goto out; |
| } |
| |
| if (freq_table[index].frequency == policy->cur) { |
| retval = 0; |
| goto out; |
| } |
| |
| retval = __target_index(policy, freq_table, index); |
| } |
| |
| out: |
| return retval; |
| } |
| EXPORT_SYMBOL_GPL(__cpufreq_driver_target); |
| |
| int cpufreq_driver_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| int ret = -EINVAL; |
| |
| down_write(&policy->rwsem); |
| |
| ret = __cpufreq_driver_target(policy, target_freq, relation); |
| |
| up_write(&policy->rwsem); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_driver_target); |
| |
| static int __cpufreq_governor(struct cpufreq_policy *policy, |
| unsigned int event) |
| { |
| int ret; |
| |
| /* Only must be defined when default governor is known to have latency |
| restrictions, like e.g. conservative or ondemand. |
| That this is the case is already ensured in Kconfig |
| */ |
| #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE |
| struct cpufreq_governor *gov = &cpufreq_gov_performance; |
| #else |
| struct cpufreq_governor *gov = NULL; |
| #endif |
| |
| /* 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; |
| |
| if (policy->governor->max_transition_latency && |
| policy->cpuinfo.transition_latency > |
| policy->governor->max_transition_latency) { |
| if (!gov) |
| return -EINVAL; |
| else { |
| pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n", |
| policy->governor->name, gov->name); |
| policy->governor = gov; |
| } |
| } |
| |
| if (event == CPUFREQ_GOV_POLICY_INIT) |
| if (!try_module_get(policy->governor->owner)) |
| return -EINVAL; |
| |
| pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
| policy->cpu, event); |
| |
| mutex_lock(&cpufreq_governor_lock); |
| if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
| || (!policy->governor_enabled |
| && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { |
| mutex_unlock(&cpufreq_governor_lock); |
| return -EBUSY; |
| } |
| |
| if (event == CPUFREQ_GOV_STOP) |
| policy->governor_enabled = false; |
| else if (event == CPUFREQ_GOV_START) |
| policy->governor_enabled = true; |
| |
| mutex_unlock(&cpufreq_governor_lock); |
| |
| ret = policy->governor->governor(policy, event); |
| |
| if (!ret) { |
| if (event == CPUFREQ_GOV_POLICY_INIT) |
| policy->governor->initialized++; |
| else if (event == CPUFREQ_GOV_POLICY_EXIT) |
| policy->governor->initialized--; |
| } else { |
| /* Restore original values */ |
| mutex_lock(&cpufreq_governor_lock); |
| if (event == CPUFREQ_GOV_STOP) |
| policy->governor_enabled = true; |
| else if (event == CPUFREQ_GOV_START) |
| policy->governor_enabled = false; |
| mutex_unlock(&cpufreq_governor_lock); |
| } |
| |
| if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
| ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) |
| module_put(policy->governor->owner); |
| |
| return ret; |
| } |
| |
| int cpufreq_register_governor(struct cpufreq_governor *governor) |
| { |
| int err; |
| |
| if (!governor) |
| return -EINVAL; |
| |
| if (cpufreq_disabled()) |
| return -ENODEV; |
| |
| mutex_lock(&cpufreq_governor_mutex); |
| |
| governor->initialized = 0; |
| 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) |
| { |
| int cpu; |
| |
| if (!governor) |
| return; |
| |
| if (cpufreq_disabled()) |
| return; |
| |
| for_each_present_cpu(cpu) { |
| if (cpu_online(cpu)) |
| continue; |
| if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) |
| strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); |
| } |
| |
| 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)); |
| |
| if (new_policy->min > policy->max || new_policy->max < policy->min) |
| 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); |
| |
| /* adjust if necessary - hardware incompatibility*/ |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_INCOMPATIBLE, 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; |
| |
| 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) |
| goto out; |
| |
| pr_debug("governor switch\n"); |
| |
| /* save old, working values */ |
| old_gov = policy->governor; |
| /* end old governor */ |
| if (old_gov) { |
| __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
| up_write(&policy->rwsem); |
| __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); |
| down_write(&policy->rwsem); |
| } |
| |
| /* start new governor */ |
| policy->governor = new_policy->governor; |
| if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { |
| if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) |
| goto out; |
| |
| up_write(&policy->rwsem); |
| __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); |
| down_write(&policy->rwsem); |
| } |
| |
| /* 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; |
| __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT); |
| __cpufreq_governor(policy, CPUFREQ_GOV_START); |
| } |
| |
| return -EINVAL; |
| |
| out: |
| pr_debug("governor: change or update limits\n"); |
| return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
| } |
| |
| /** |
| * cpufreq_update_policy - re-evaluate an existing cpufreq policy |
| * @cpu: CPU which shall be re-evaluated |
| * |
| * Useful for policy notifiers which have different necessities |
| * at different times. |
| */ |
| int cpufreq_update_policy(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
| struct cpufreq_policy new_policy; |
| int ret; |
| |
| if (!policy) |
| return -ENODEV; |
| |
| down_write(&policy->rwsem); |
| |
| 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; |
| new_policy.policy = policy->user_policy.policy; |
| new_policy.governor = policy->user_policy.governor; |
| |
| /* |
| * BIOS might change freq behind our back |
| * -> ask driver for current freq and notify governors about a change |
| */ |
| if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
| new_policy.cur = cpufreq_driver->get(cpu); |
| if (WARN_ON(!new_policy.cur)) { |
| ret = -EIO; |
| goto unlock; |
| } |
| |
| if (!policy->cur) { |
| pr_debug("Driver did not initialize current freq\n"); |
| policy->cur = new_policy.cur; |
| } else { |
| if (policy->cur != new_policy.cur && has_target()) |
| cpufreq_out_of_sync(policy, new_policy.cur); |
| } |
| } |
| |
| ret = cpufreq_set_policy(policy, &new_policy); |
| |
| unlock: |
| up_write(&policy->rwsem); |
| |
| cpufreq_cpu_put(policy); |
| return ret; |
| } |
| EXPORT_SYMBOL(cpufreq_update_policy); |
| |
| static int cpufreq_cpu_callback(struct notifier_block *nfb, |
| unsigned long action, void *hcpu) |
| { |
| unsigned int cpu = (unsigned long)hcpu; |
| struct device *dev; |
| |
| dev = get_cpu_device(cpu); |
| if (dev) { |
| switch (action & ~CPU_TASKS_FROZEN) { |
| case CPU_ONLINE: |
| __cpufreq_add_dev(dev, NULL); |
| break; |
| |
| case CPU_DOWN_PREPARE: |
| __cpufreq_remove_dev_prepare(dev, NULL); |
| break; |
| |
| case CPU_POST_DEAD: |
| __cpufreq_remove_dev_finish(dev, NULL); |
| break; |
| |
| case CPU_DOWN_FAILED: |
| __cpufreq_add_dev(dev, NULL); |
| break; |
| } |
| } |
| return NOTIFY_OK; |
| } |
| |
| static struct notifier_block __refdata cpufreq_cpu_notifier = { |
| .notifier_call = cpufreq_cpu_callback, |
| }; |
| |
| /********************************************************************* |
| * BOOST * |
| *********************************************************************/ |
| static int cpufreq_boost_set_sw(int state) |
| { |
| struct cpufreq_frequency_table *freq_table; |
| struct cpufreq_policy *policy; |
| int ret = -EINVAL; |
| |
| list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { |
| freq_table = cpufreq_frequency_get_table(policy->cpu); |
| if (freq_table) { |
| ret = cpufreq_frequency_table_cpuinfo(policy, |
| freq_table); |
| if (ret) { |
| pr_err("%s: Policy frequency update failed\n", |
| __func__); |
| break; |
| } |
| policy->user_policy.max = policy->max; |
| __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
| } |
| } |
| |
| 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; |
| } |
| |
| int cpufreq_boost_supported(void) |
| { |
| if (likely(cpufreq_driver)) |
| return cpufreq_driver->boost_supported; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_boost_supported); |
| |
| int cpufreq_boost_enabled(void) |
| { |
| return cpufreq_driver->boost_enabled; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); |
| |
| /********************************************************************* |
| * REGISTER / UNREGISTER CPUFREQ DRIVER * |
| *********************************************************************/ |
| |
| /** |
| * cpufreq_register_driver - register a CPU Frequency driver |
| * @driver_data: A struct cpufreq_driver containing the values# |
| * submitted by the CPU Frequency driver. |
| * |
| * Registers a CPU Frequency driver to this core code. This code |
| * returns zero on success, -EBUSY when another driver got here first |
| * (and isn't unregistered in the meantime). |
| * |
| */ |
| int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
| { |
| unsigned long flags; |
| int ret; |
| |
| if (cpufreq_disabled()) |
| return -ENODEV; |
| |
| if (!driver_data || !driver_data->verify || !driver_data->init || |
| !(driver_data->setpolicy || driver_data->target_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); |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| if (cpufreq_driver) { |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| return -EEXIST; |
| } |
| 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()) { |
| /* |
| * Check if driver provides function to enable boost - |
| * if not, use cpufreq_boost_set_sw as default |
| */ |
| if (!cpufreq_driver->set_boost) |
| cpufreq_driver->set_boost = cpufreq_boost_set_sw; |
| |
| ret = cpufreq_sysfs_create_file(&boost.attr); |
| if (ret) { |
| pr_err("%s: cannot register global BOOST sysfs file\n", |
| __func__); |
| 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 */ |
| pr_debug("%s: No CPU initialized for driver %s\n", __func__, |
| driver_data->name); |
| goto err_if_unreg; |
| } |
| |
| register_hotcpu_notifier(&cpufreq_cpu_notifier); |
| pr_debug("driver %s up and running\n", driver_data->name); |
| |
| return 0; |
| err_if_unreg: |
| subsys_interface_unregister(&cpufreq_interface); |
| err_boost_unreg: |
| if (cpufreq_boost_supported()) |
| cpufreq_sysfs_remove_file(&boost.attr); |
| err_null_driver: |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| cpufreq_driver = NULL; |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_register_driver); |
| |
| /** |
| * cpufreq_unregister_driver - unregister the current CPUFreq driver |
| * |
| * Unregister the current CPUFreq driver. Only call this if you have |
| * the right to do so, i.e. if you have succeeded in initialising before! |
| * Returns zero if successful, and -EINVAL if the cpufreq_driver is |
| * currently not initialised. |
| */ |
| int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
| { |
| unsigned long flags; |
| |
| if (!cpufreq_driver || (driver != cpufreq_driver)) |
| return -EINVAL; |
| |
| pr_debug("unregistering driver %s\n", driver->name); |
| |
| subsys_interface_unregister(&cpufreq_interface); |
| if (cpufreq_boost_supported()) |
| cpufreq_sysfs_remove_file(&boost.attr); |
| |
| unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
| |
| down_write(&cpufreq_rwsem); |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| |
| cpufreq_driver = NULL; |
| |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| up_write(&cpufreq_rwsem); |
| |
| 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, |
| }; |
| |
| static int __init cpufreq_core_init(void) |
| { |
| if (cpufreq_disabled()) |
| return -ENODEV; |
| |
| cpufreq_global_kobject = kobject_create(); |
| BUG_ON(!cpufreq_global_kobject); |
| |
| register_syscore_ops(&cpufreq_syscore_ops); |
| |
| return 0; |
| } |
| core_initcall(cpufreq_core_init); |