| /* |
| * linux/drivers/cpufreq/cpufreq.c |
| * |
| * Copyright (C) 2001 Russell King |
| * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> |
| * |
| * 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 <asm/cputime.h> |
| #include <linux/kernel.h> |
| #include <linux/kernel_stat.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/notifier.h> |
| #include <linux/cpufreq.h> |
| #include <linux/delay.h> |
| #include <linux/interrupt.h> |
| #include <linux/spinlock.h> |
| #include <linux/tick.h> |
| #include <linux/device.h> |
| #include <linux/slab.h> |
| #include <linux/cpu.h> |
| #include <linux/completion.h> |
| #include <linux/mutex.h> |
| #include <linux/syscore_ops.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); |
| #ifdef CONFIG_HOTPLUG_CPU |
| /* This one keeps track of the previously set governor of a removed CPU */ |
| static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
| #endif |
| static DEFINE_RWLOCK(cpufreq_driver_lock); |
| |
| /* |
| * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure |
| * all cpufreq/hotplug/workqueue/etc related lock issues. |
| * |
| * The rules for this semaphore: |
| * - Any routine that wants to read from the policy structure will |
| * do a down_read on this semaphore. |
| * - Any routine that will write to the policy structure and/or may take away |
| * the policy altogether (eg. CPU hotplug), will hold this lock in write |
| * mode before doing so. |
| * |
| * Additional rules: |
| * - Governor routines that can be called in cpufreq hotplug path should not |
| * take this sem as top level hotplug notifier handler takes this. |
| * - Lock should not be held across |
| * __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
| */ |
| static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
| static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
| |
| #define lock_policy_rwsem(mode, cpu) \ |
| static int lock_policy_rwsem_##mode(int cpu) \ |
| { \ |
| int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
| BUG_ON(policy_cpu == -1); \ |
| down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ |
| \ |
| return 0; \ |
| } |
| |
| lock_policy_rwsem(read, cpu); |
| lock_policy_rwsem(write, cpu); |
| |
| #define unlock_policy_rwsem(mode, cpu) \ |
| static void unlock_policy_rwsem_##mode(int cpu) \ |
| { \ |
| int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
| BUG_ON(policy_cpu == -1); \ |
| up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ |
| } |
| |
| unlock_policy_rwsem(read, cpu); |
| unlock_policy_rwsem(write, cpu); |
| |
| /* internal prototypes */ |
| static int __cpufreq_governor(struct cpufreq_policy *policy, |
| unsigned int event); |
| static unsigned int __cpufreq_get(unsigned int cpu); |
| 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->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); |
| |
| static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
| { |
| struct cpufreq_policy *data; |
| unsigned long flags; |
| |
| if (cpu >= nr_cpu_ids) |
| goto err_out; |
| |
| /* get the cpufreq driver */ |
| read_lock_irqsave(&cpufreq_driver_lock, flags); |
| |
| if (!cpufreq_driver) |
| goto err_out_unlock; |
| |
| if (!try_module_get(cpufreq_driver->owner)) |
| goto err_out_unlock; |
| |
| |
| /* get the CPU */ |
| data = per_cpu(cpufreq_cpu_data, cpu); |
| |
| if (!data) |
| goto err_out_put_module; |
| |
| if (!sysfs && !kobject_get(&data->kobj)) |
| goto err_out_put_module; |
| |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| return data; |
| |
| err_out_put_module: |
| module_put(cpufreq_driver->owner); |
| err_out_unlock: |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| err_out: |
| return NULL; |
| } |
| |
| struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
| { |
| if (cpufreq_disabled()) |
| return NULL; |
| |
| return __cpufreq_cpu_get(cpu, false); |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
| |
| static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
| { |
| return __cpufreq_cpu_get(cpu, true); |
| } |
| |
| static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) |
| { |
| if (!sysfs) |
| kobject_put(&data->kobj); |
| module_put(cpufreq_driver->owner); |
| } |
| |
| void cpufreq_cpu_put(struct cpufreq_policy *data) |
| { |
| if (cpufreq_disabled()) |
| return; |
| |
| __cpufreq_cpu_put(data, false); |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_cpu_put); |
| |
| static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
| { |
| __cpufreq_cpu_put(data, true); |
| } |
| |
| /********************************************************************* |
| * 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. |
| */ |
| #ifndef CONFIG_SMP |
| static unsigned long l_p_j_ref; |
| static unsigned int l_p_j_ref_freq; |
| |
| static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
| { |
| 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) || |
| (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
| 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); |
| } |
| } |
| #else |
| static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
| { |
| return; |
| } |
| #endif |
| |
| |
| 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", (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. |
| */ |
| 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); |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
| |
| |
| |
| /********************************************************************* |
| * SYSFS INTERFACE * |
| *********************************************************************/ |
| |
| 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 (!strnicmp(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 (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
| *policy = CPUFREQ_POLICY_PERFORMANCE; |
| err = 0; |
| } else if (!strnicmp(str_governor, "powersave", |
| CPUFREQ_NAME_LEN)) { |
| *policy = CPUFREQ_POLICY_POWERSAVE; |
| err = 0; |
| } |
| } else if (cpufreq_driver->target) { |
| 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); |
| show_one(scaling_cur_freq, cur); |
| |
| static int __cpufreq_set_policy(struct cpufreq_policy *data, |
| struct cpufreq_policy *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) \ |
| { \ |
| unsigned int ret; \ |
| 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; \ |
| \ |
| ret = __cpufreq_set_policy(policy, &new_policy); \ |
| policy->user_policy.object = policy->object; \ |
| \ |
| 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->cpu); |
| 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) |
| { |
| unsigned 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; |
| |
| /* Do not use cpufreq_set_policy here or the user_policy.max |
| will be wrongly overridden */ |
| 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 (!cpufreq_driver->target) { |
| i += sprintf(buf, "performance powersave"); |
| goto out; |
| } |
| |
| list_for_each_entry(t, &cpufreq_governor_list, governor_list) { |
| if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
| - (CPUFREQ_NAME_LEN + 2))) |
| goto out; |
| i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
| } |
| out: |
| i += sprintf(&buf[i], "\n"); |
| return i; |
| } |
| |
| static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
| { |
| ssize_t i = 0; |
| unsigned int cpu; |
| |
| for_each_cpu(cpu, mask) { |
| if (i) |
| i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); |
| i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); |
| if (i >= (PAGE_SIZE - 5)) |
| break; |
| } |
| i += sprintf(&buf[i], "\n"); |
| return i; |
| } |
| |
| /** |
| * show_related_cpus - show the CPUs affected by each transition even if |
| * hw coordination is in use |
| */ |
| static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) |
| { |
| return show_cpus(policy->related_cpus, buf); |
| } |
| |
| /** |
| * show_affected_cpus - show the CPUs affected by each transition |
| */ |
| static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) |
| { |
| return show_cpus(policy->cpus, buf); |
| } |
| |
| static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
| const char *buf, size_t count) |
| { |
| unsigned int freq = 0; |
| unsigned int ret; |
| |
| if (!policy->governor || !policy->governor->store_setspeed) |
| return -EINVAL; |
| |
| ret = sscanf(buf, "%u", &freq); |
| if (ret != 1) |
| return -EINVAL; |
| |
| policy->governor->store_setspeed(policy, freq); |
| |
| return count; |
| } |
| |
| static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) |
| { |
| if (!policy->governor || !policy->governor->show_setspeed) |
| return sprintf(buf, "<unsupported>\n"); |
| |
| return policy->governor->show_setspeed(policy, buf); |
| } |
| |
| /** |
| * show_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 = -EINVAL; |
| policy = cpufreq_cpu_get_sysfs(policy->cpu); |
| if (!policy) |
| goto no_policy; |
| |
| if (lock_policy_rwsem_read(policy->cpu) < 0) |
| goto fail; |
| |
| if (fattr->show) |
| ret = fattr->show(policy, buf); |
| else |
| ret = -EIO; |
| |
| unlock_policy_rwsem_read(policy->cpu); |
| fail: |
| cpufreq_cpu_put_sysfs(policy); |
| no_policy: |
| return ret; |
| } |
| |
| static ssize_t store(struct kobject *kobj, struct attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct cpufreq_policy *policy = to_policy(kobj); |
| struct freq_attr *fattr = to_attr(attr); |
| ssize_t ret = -EINVAL; |
| policy = cpufreq_cpu_get_sysfs(policy->cpu); |
| if (!policy) |
| goto no_policy; |
| |
| if (lock_policy_rwsem_write(policy->cpu) < 0) |
| goto fail; |
| |
| if (fattr->store) |
| ret = fattr->store(policy, buf, count); |
| else |
| ret = -EIO; |
| |
| unlock_policy_rwsem_write(policy->cpu); |
| fail: |
| cpufreq_cpu_put_sysfs(policy); |
| no_policy: |
| return ret; |
| } |
| |
| static void cpufreq_sysfs_release(struct kobject *kobj) |
| { |
| struct cpufreq_policy *policy = to_policy(kobj); |
| pr_debug("last reference is dropped\n"); |
| complete(&policy->kobj_unregister); |
| } |
| |
| static const struct sysfs_ops sysfs_ops = { |
| .show = show, |
| .store = store, |
| }; |
| |
| static struct kobj_type ktype_cpufreq = { |
| .sysfs_ops = &sysfs_ops, |
| .default_attrs = default_attrs, |
| .release = cpufreq_sysfs_release, |
| }; |
| |
| 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(unsigned int cpu, |
| struct cpufreq_policy *policy) |
| { |
| unsigned int j; |
| int ret = 0; |
| |
| for_each_cpu(j, policy->cpus) { |
| struct cpufreq_policy *managed_policy; |
| struct device *cpu_dev; |
| |
| if (j == cpu) |
| continue; |
| |
| pr_debug("CPU %u already managed, adding link\n", j); |
| managed_policy = cpufreq_cpu_get(cpu); |
| cpu_dev = get_cpu_device(j); |
| ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
| "cpufreq"); |
| if (ret) { |
| cpufreq_cpu_put(managed_policy); |
| return ret; |
| } |
| } |
| return ret; |
| } |
| |
| static int cpufreq_add_dev_interface(unsigned int cpu, |
| struct cpufreq_policy *policy, |
| struct device *dev) |
| { |
| struct cpufreq_policy new_policy; |
| struct freq_attr **drv_attr; |
| unsigned long flags; |
| int ret = 0; |
| unsigned int j; |
| |
| /* prepare interface data */ |
| ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, |
| &dev->kobj, "cpufreq"); |
| if (ret) |
| return ret; |
| |
| /* set up files for this cpu device */ |
| drv_attr = cpufreq_driver->attr; |
| while ((drv_attr) && (*drv_attr)) { |
| ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
| if (ret) |
| goto err_out_kobj_put; |
| drv_attr++; |
| } |
| if (cpufreq_driver->get) { |
| ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
| if (ret) |
| goto err_out_kobj_put; |
| } |
| if (cpufreq_driver->target) { |
| ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
| if (ret) |
| goto err_out_kobj_put; |
| } |
| if (cpufreq_driver->bios_limit) { |
| ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
| if (ret) |
| goto err_out_kobj_put; |
| } |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| for_each_cpu(j, policy->cpus) { |
| per_cpu(cpufreq_cpu_data, j) = policy; |
| per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
| } |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| ret = cpufreq_add_dev_symlink(cpu, policy); |
| if (ret) |
| goto err_out_kobj_put; |
| |
| memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
| /* assure that the starting sequence is run in __cpufreq_set_policy */ |
| policy->governor = NULL; |
| |
| /* set default policy */ |
| ret = __cpufreq_set_policy(policy, &new_policy); |
| policy->user_policy.policy = policy->policy; |
| policy->user_policy.governor = policy->governor; |
| |
| if (ret) { |
| pr_debug("setting policy failed\n"); |
| if (cpufreq_driver->exit) |
| cpufreq_driver->exit(policy); |
| } |
| return ret; |
| |
| err_out_kobj_put: |
| kobject_put(&policy->kobj); |
| wait_for_completion(&policy->kobj_unregister); |
| return ret; |
| } |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, |
| struct device *dev) |
| { |
| struct cpufreq_policy *policy; |
| int ret = 0, has_target = !!cpufreq_driver->target; |
| unsigned long flags; |
| |
| policy = cpufreq_cpu_get(sibling); |
| WARN_ON(!policy); |
| |
| if (has_target) |
| __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
| |
| lock_policy_rwsem_write(sibling); |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| |
| cpumask_set_cpu(cpu, policy->cpus); |
| per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; |
| per_cpu(cpufreq_cpu_data, cpu) = policy; |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| unlock_policy_rwsem_write(sibling); |
| |
| if (has_target) { |
| __cpufreq_governor(policy, CPUFREQ_GOV_START); |
| __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
| } |
| |
| ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
| if (ret) { |
| cpufreq_cpu_put(policy); |
| return ret; |
| } |
| |
| return 0; |
| } |
| #endif |
| |
| /** |
| * cpufreq_add_dev - add a CPU device |
| * |
| * Adds the cpufreq interface for a CPU device. |
| * |
| * The Oracle says: try running cpufreq registration/unregistration concurrently |
| * with with cpu hotplugging and all hell will break loose. Tried to clean this |
| * mess up, but more thorough testing is needed. - Mathieu |
| */ |
| static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
| { |
| unsigned int j, cpu = dev->id; |
| int ret = -ENOMEM; |
| struct cpufreq_policy *policy; |
| unsigned long flags; |
| #ifdef CONFIG_HOTPLUG_CPU |
| struct cpufreq_governor *gov; |
| int sibling; |
| #endif |
| |
| if (cpu_is_offline(cpu)) |
| return 0; |
| |
| pr_debug("adding CPU %u\n", cpu); |
| |
| #ifdef CONFIG_SMP |
| /* check whether a different CPU already registered this |
| * CPU because it is in the same boat. */ |
| policy = cpufreq_cpu_get(cpu); |
| if (unlikely(policy)) { |
| cpufreq_cpu_put(policy); |
| return 0; |
| } |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| /* Check if this cpu was hot-unplugged earlier and has siblings */ |
| read_lock_irqsave(&cpufreq_driver_lock, flags); |
| for_each_online_cpu(sibling) { |
| struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); |
| if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| return cpufreq_add_policy_cpu(cpu, sibling, dev); |
| } |
| } |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| #endif |
| #endif |
| |
| if (!try_module_get(cpufreq_driver->owner)) { |
| ret = -EINVAL; |
| goto module_out; |
| } |
| |
| policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
| if (!policy) |
| goto nomem_out; |
| |
| if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) |
| goto err_free_policy; |
| |
| if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) |
| goto err_free_cpumask; |
| |
| policy->cpu = cpu; |
| policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
| cpumask_copy(policy->cpus, cpumask_of(cpu)); |
| |
| /* Initially set CPU itself as the policy_cpu */ |
| per_cpu(cpufreq_policy_cpu, cpu) = 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; |
| } |
| |
| /* 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); |
| |
| policy->user_policy.min = policy->min; |
| policy->user_policy.max = policy->max; |
| |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_START, policy); |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); |
| if (gov) { |
| policy->governor = gov; |
| pr_debug("Restoring governor %s for cpu %d\n", |
| policy->governor->name, cpu); |
| } |
| #endif |
| |
| ret = cpufreq_add_dev_interface(cpu, policy, dev); |
| if (ret) |
| goto err_out_unregister; |
| |
| kobject_uevent(&policy->kobj, KOBJ_ADD); |
| module_put(cpufreq_driver->owner); |
| pr_debug("initialization complete\n"); |
| |
| return 0; |
| |
| err_out_unregister: |
| 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); |
| |
| kobject_put(&policy->kobj); |
| wait_for_completion(&policy->kobj_unregister); |
| |
| err_set_policy_cpu: |
| per_cpu(cpufreq_policy_cpu, cpu) = -1; |
| free_cpumask_var(policy->related_cpus); |
| err_free_cpumask: |
| free_cpumask_var(policy->cpus); |
| err_free_policy: |
| kfree(policy); |
| nomem_out: |
| module_put(cpufreq_driver->owner); |
| module_out: |
| return ret; |
| } |
| |
| static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
| { |
| int j; |
| |
| policy->last_cpu = policy->cpu; |
| policy->cpu = cpu; |
| |
| for_each_cpu(j, policy->cpus) |
| per_cpu(cpufreq_policy_cpu, j) = cpu; |
| |
| #ifdef CONFIG_CPU_FREQ_TABLE |
| cpufreq_frequency_table_update_policy_cpu(policy); |
| #endif |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_UPDATE_POLICY_CPU, policy); |
| } |
| |
| /** |
| * __cpufreq_remove_dev - remove a CPU device |
| * |
| * Removes the cpufreq interface for a CPU device. |
| * Caller should already have policy_rwsem in write mode for this CPU. |
| * This routine frees the rwsem before returning. |
| */ |
| static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
| { |
| unsigned int cpu = dev->id, ret, cpus; |
| unsigned long flags; |
| struct cpufreq_policy *data; |
| struct kobject *kobj; |
| struct completion *cmp; |
| struct device *cpu_dev; |
| |
| pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| |
| data = per_cpu(cpufreq_cpu_data, cpu); |
| per_cpu(cpufreq_cpu_data, cpu) = NULL; |
| |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| if (!data) { |
| pr_debug("%s: No cpu_data found\n", __func__); |
| return -EINVAL; |
| } |
| |
| if (cpufreq_driver->target) |
| __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| if (!cpufreq_driver->setpolicy) |
| strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
| data->governor->name, CPUFREQ_NAME_LEN); |
| #endif |
| |
| WARN_ON(lock_policy_rwsem_write(cpu)); |
| cpus = cpumask_weight(data->cpus); |
| |
| if (cpus > 1) |
| cpumask_clear_cpu(cpu, data->cpus); |
| unlock_policy_rwsem_write(cpu); |
| |
| if (cpu != data->cpu) { |
| sysfs_remove_link(&dev->kobj, "cpufreq"); |
| } else if (cpus > 1) { |
| /* first sibling now owns the new sysfs dir */ |
| cpu_dev = get_cpu_device(cpumask_first(data->cpus)); |
| sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
| ret = kobject_move(&data->kobj, &cpu_dev->kobj); |
| if (ret) { |
| pr_err("%s: Failed to move kobj: %d", __func__, ret); |
| |
| WARN_ON(lock_policy_rwsem_write(cpu)); |
| cpumask_set_cpu(cpu, data->cpus); |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| per_cpu(cpufreq_cpu_data, cpu) = data; |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| unlock_policy_rwsem_write(cpu); |
| |
| ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, |
| "cpufreq"); |
| return -EINVAL; |
| } |
| |
| WARN_ON(lock_policy_rwsem_write(cpu)); |
| update_policy_cpu(data, cpu_dev->id); |
| unlock_policy_rwsem_write(cpu); |
| pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
| __func__, cpu_dev->id, cpu); |
| } |
| |
| if ((cpus == 1) && (cpufreq_driver->target)) |
| __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); |
| |
| pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); |
| cpufreq_cpu_put(data); |
| |
| /* If cpu is last user of policy, free policy */ |
| if (cpus == 1) { |
| lock_policy_rwsem_read(cpu); |
| kobj = &data->kobj; |
| cmp = &data->kobj_unregister; |
| unlock_policy_rwsem_read(cpu); |
| kobject_put(kobj); |
| |
| /* we need to make sure that the underlying kobj is actually |
| * not referenced anymore by anybody before we proceed with |
| * unloading. |
| */ |
| pr_debug("waiting for dropping of refcount\n"); |
| wait_for_completion(cmp); |
| pr_debug("wait complete\n"); |
| |
| if (cpufreq_driver->exit) |
| cpufreq_driver->exit(data); |
| |
| free_cpumask_var(data->related_cpus); |
| free_cpumask_var(data->cpus); |
| kfree(data); |
| } else if (cpufreq_driver->target) { |
| __cpufreq_governor(data, CPUFREQ_GOV_START); |
| __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
| } |
| |
| per_cpu(cpufreq_policy_cpu, cpu) = -1; |
| return 0; |
| } |
| |
| |
| static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
| { |
| unsigned int cpu = dev->id; |
| int retval; |
| |
| if (cpu_is_offline(cpu)) |
| return 0; |
| |
| retval = __cpufreq_remove_dev(dev, sif); |
| return retval; |
| } |
| |
| |
| static void handle_update(struct work_struct *work) |
| { |
| struct cpufreq_policy *policy = |
| container_of(work, struct cpufreq_policy, update); |
| unsigned int cpu = policy->cpu; |
| pr_debug("handle_update for cpu %u called\n", cpu); |
| cpufreq_update_policy(cpu); |
| } |
| |
| /** |
| * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. |
| * @cpu: cpu number |
| * @old_freq: CPU frequency the kernel thinks the CPU runs at |
| * @new_freq: CPU frequency the CPU actually runs at |
| * |
| * We adjust to current frequency first, and need to clean up later. |
| * So either call to cpufreq_update_policy() or schedule handle_update()). |
| */ |
| static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
| unsigned int new_freq) |
| { |
| struct cpufreq_policy *policy; |
| struct cpufreq_freqs freqs; |
| unsigned long flags; |
| |
| |
| pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
| "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
| |
| freqs.old = old_freq; |
| freqs.new = new_freq; |
| |
| read_lock_irqsave(&cpufreq_driver_lock, flags); |
| policy = per_cpu(cpufreq_cpu_data, cpu); |
| read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); |
| cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); |
| } |
| |
| |
| /** |
| * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
| * @cpu: CPU number |
| * |
| * This is the last known freq, without actually getting it from the driver. |
| * Return value will be same as what is shown in scaling_cur_freq in sysfs. |
| */ |
| unsigned int cpufreq_quick_get(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy; |
| 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(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
| unsigned int ret_freq = 0; |
| |
| if (!cpufreq_driver->get) |
| return ret_freq; |
| |
| ret_freq = cpufreq_driver->get(cpu); |
| |
| if (ret_freq && policy->cur && |
| !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
| /* verify no discrepancy between actual and |
| saved value exists */ |
| if (unlikely(ret_freq != policy->cur)) { |
| cpufreq_out_of_sync(cpu, policy->cur, ret_freq); |
| schedule_work(&policy->update); |
| } |
| } |
| |
| return ret_freq; |
| } |
| |
| /** |
| * cpufreq_get - get the current CPU frequency (in kHz) |
| * @cpu: CPU number |
| * |
| * Get the CPU current (static) CPU frequency |
| */ |
| unsigned int cpufreq_get(unsigned int cpu) |
| { |
| unsigned int ret_freq = 0; |
| struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
| |
| if (!policy) |
| goto out; |
| |
| if (unlikely(lock_policy_rwsem_read(cpu))) |
| goto out_policy; |
| |
| ret_freq = __cpufreq_get(cpu); |
| |
| unlock_policy_rwsem_read(cpu); |
| |
| out_policy: |
| cpufreq_cpu_put(policy); |
| out: |
| return ret_freq; |
| } |
| EXPORT_SYMBOL(cpufreq_get); |
| |
| static struct subsys_interface cpufreq_interface = { |
| .name = "cpufreq", |
| .subsys = &cpu_subsys, |
| .add_dev = cpufreq_add_dev, |
| .remove_dev = cpufreq_remove_dev, |
| }; |
| |
| |
| /** |
| * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
| * |
| * This function is only executed for the boot processor. The other CPUs |
| * have been put offline by means of CPU hotplug. |
| */ |
| static int cpufreq_bp_suspend(void) |
| { |
| int ret = 0; |
| |
| int cpu = smp_processor_id(); |
| struct cpufreq_policy *cpu_policy; |
| |
| pr_debug("suspending cpu %u\n", cpu); |
| |
| /* If there's no policy for the boot CPU, we have nothing to do. */ |
| cpu_policy = cpufreq_cpu_get(cpu); |
| if (!cpu_policy) |
| return 0; |
| |
| if (cpufreq_driver->suspend) { |
| ret = cpufreq_driver->suspend(cpu_policy); |
| if (ret) |
| printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
| "step on CPU %u\n", cpu_policy->cpu); |
| } |
| |
| cpufreq_cpu_put(cpu_policy); |
| return ret; |
| } |
| |
| /** |
| * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
| * |
| * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) |
| * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
| * restored. It will verify that the current freq is in sync with |
| * what we believe it to be. This is a bit later than when it |
| * should be, but nonethteless it's better than calling |
| * cpufreq_driver->get() here which might re-enable interrupts... |
| * |
| * This function is only executed for the boot CPU. The other CPUs have not |
| * been turned on yet. |
| */ |
| static void cpufreq_bp_resume(void) |
| { |
| int ret = 0; |
| |
| int cpu = smp_processor_id(); |
| struct cpufreq_policy *cpu_policy; |
| |
| pr_debug("resuming cpu %u\n", cpu); |
| |
| /* If there's no policy for the boot CPU, we have nothing to do. */ |
| cpu_policy = cpufreq_cpu_get(cpu); |
| if (!cpu_policy) |
| return; |
| |
| if (cpufreq_driver->resume) { |
| ret = cpufreq_driver->resume(cpu_policy); |
| if (ret) { |
| printk(KERN_ERR "cpufreq: resume failed in ->resume " |
| "step on CPU %u\n", cpu_policy->cpu); |
| goto fail; |
| } |
| } |
| |
| schedule_work(&cpu_policy->update); |
| |
| fail: |
| cpufreq_cpu_put(cpu_policy); |
| } |
| |
| static struct syscore_ops cpufreq_syscore_ops = { |
| .suspend = cpufreq_bp_suspend, |
| .resume = cpufreq_bp_resume, |
| }; |
| |
| /** |
| * 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); |
| |
| /********************************************************************* |
| * 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 * |
| *********************************************************************/ |
| |
| |
| int __cpufreq_driver_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| int retval = -EINVAL; |
| unsigned int old_target_freq = target_freq; |
| |
| 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); |
| |
| if (target_freq == policy->cur) |
| return 0; |
| |
| if (cpufreq_driver->target) |
| retval = cpufreq_driver->target(policy, target_freq, relation); |
| |
| return retval; |
| } |
| EXPORT_SYMBOL_GPL(__cpufreq_driver_target); |
| |
| int cpufreq_driver_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| int ret = -EINVAL; |
| |
| policy = cpufreq_cpu_get(policy->cpu); |
| if (!policy) |
| goto no_policy; |
| |
| if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
| goto fail; |
| |
| ret = __cpufreq_driver_target(policy, target_freq, relation); |
| |
| unlock_policy_rwsem_write(policy->cpu); |
| |
| fail: |
| cpufreq_cpu_put(policy); |
| no_policy: |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_driver_target); |
| |
| int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
| { |
| int ret = 0; |
| |
| if (cpufreq_disabled()) |
| return ret; |
| |
| if (!cpufreq_driver->getavg) |
| return 0; |
| |
| policy = cpufreq_cpu_get(policy->cpu); |
| if (!policy) |
| return -EINVAL; |
| |
| ret = cpufreq_driver->getavg(policy, cpu); |
| |
| cpufreq_cpu_put(policy); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
| |
| /* |
| * when "event" is CPUFREQ_GOV_LIMITS |
| */ |
| |
| static int __cpufreq_governor(struct cpufreq_policy *policy, |
| unsigned int event) |
| { |
| int ret; |
| |
| /* Only must be defined when default governor is known to have latency |
| restrictions, like e.g. conservative or ondemand. |
| That this is the case is already ensured in Kconfig |
| */ |
| #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE |
| struct cpufreq_governor *gov = &cpufreq_gov_performance; |
| #else |
| struct cpufreq_governor *gov = NULL; |
| #endif |
| |
| if (policy->governor->max_transition_latency && |
| policy->cpuinfo.transition_latency > |
| policy->governor->max_transition_latency) { |
| if (!gov) |
| return -EINVAL; |
| else { |
| printk(KERN_WARNING "%s governor failed, too long" |
| " transition latency of HW, fallback" |
| " to %s governor\n", |
| policy->governor->name, |
| gov->name); |
| policy->governor = gov; |
| } |
| } |
| |
| if (!try_module_get(policy->governor->owner)) |
| return -EINVAL; |
| |
| pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
| policy->cpu, event); |
| ret = policy->governor->governor(policy, event); |
| |
| if (!ret) { |
| if (event == CPUFREQ_GOV_POLICY_INIT) |
| policy->governor->initialized++; |
| else if (event == CPUFREQ_GOV_POLICY_EXIT) |
| policy->governor->initialized--; |
| } |
| |
| /* we keep one module reference alive for |
| each CPU governed by this CPU */ |
| if ((event != CPUFREQ_GOV_START) || ret) |
| module_put(policy->governor->owner); |
| if ((event == CPUFREQ_GOV_STOP) && !ret) |
| module_put(policy->governor->owner); |
| |
| return ret; |
| } |
| |
| |
| int cpufreq_register_governor(struct cpufreq_governor *governor) |
| { |
| int err; |
| |
| if (!governor) |
| return -EINVAL; |
| |
| if (cpufreq_disabled()) |
| return -ENODEV; |
| |
| mutex_lock(&cpufreq_governor_mutex); |
| |
| governor->initialized = 0; |
| err = -EBUSY; |
| if (__find_governor(governor->name) == NULL) { |
| err = 0; |
| list_add(&governor->governor_list, &cpufreq_governor_list); |
| } |
| |
| mutex_unlock(&cpufreq_governor_mutex); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_register_governor); |
| |
| |
| void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
| { |
| #ifdef CONFIG_HOTPLUG_CPU |
| int cpu; |
| #endif |
| |
| if (!governor) |
| return; |
| |
| if (cpufreq_disabled()) |
| return; |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| for_each_present_cpu(cpu) { |
| if (cpu_online(cpu)) |
| continue; |
| if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) |
| strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); |
| } |
| #endif |
| |
| mutex_lock(&cpufreq_governor_mutex); |
| list_del(&governor->governor_list); |
| mutex_unlock(&cpufreq_governor_mutex); |
| return; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); |
| |
| |
| |
| /********************************************************************* |
| * POLICY INTERFACE * |
| *********************************************************************/ |
| |
| /** |
| * cpufreq_get_policy - get the current cpufreq_policy |
| * @policy: struct cpufreq_policy into which the current cpufreq_policy |
| * is written |
| * |
| * Reads the current cpufreq policy. |
| */ |
| int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) |
| { |
| struct cpufreq_policy *cpu_policy; |
| if (!policy) |
| return -EINVAL; |
| |
| cpu_policy = cpufreq_cpu_get(cpu); |
| if (!cpu_policy) |
| return -EINVAL; |
| |
| memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
| |
| cpufreq_cpu_put(cpu_policy); |
| return 0; |
| } |
| EXPORT_SYMBOL(cpufreq_get_policy); |
| |
| |
| /* |
| * data : current policy. |
| * policy : policy to be set. |
| */ |
| static int __cpufreq_set_policy(struct cpufreq_policy *data, |
| struct cpufreq_policy *policy) |
| { |
| int ret = 0, failed = 1; |
| |
| pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
| policy->min, policy->max); |
| |
| memcpy(&policy->cpuinfo, &data->cpuinfo, |
| sizeof(struct cpufreq_cpuinfo)); |
| |
| if (policy->min > data->max || policy->max < data->min) { |
| ret = -EINVAL; |
| goto error_out; |
| } |
| |
| /* verify the cpu speed can be set within this limit */ |
| ret = cpufreq_driver->verify(policy); |
| if (ret) |
| goto error_out; |
| |
| /* adjust if necessary - all reasons */ |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_ADJUST, policy); |
| |
| /* adjust if necessary - hardware incompatibility*/ |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_INCOMPATIBLE, policy); |
| |
| /* verify the cpu speed can be set within this limit, |
| which might be different to the first one */ |
| ret = cpufreq_driver->verify(policy); |
| if (ret) |
| goto error_out; |
| |
| /* notification of the new policy */ |
| blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
| CPUFREQ_NOTIFY, policy); |
| |
| data->min = policy->min; |
| data->max = policy->max; |
| |
| pr_debug("new min and max freqs are %u - %u kHz\n", |
| data->min, data->max); |
| |
| if (cpufreq_driver->setpolicy) { |
| data->policy = policy->policy; |
| pr_debug("setting range\n"); |
| ret = cpufreq_driver->setpolicy(policy); |
| } else { |
| if (policy->governor != data->governor) { |
| /* save old, working values */ |
| struct cpufreq_governor *old_gov = data->governor; |
| |
| pr_debug("governor switch\n"); |
| |
| /* end old governor */ |
| if (data->governor) { |
| __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
| unlock_policy_rwsem_write(policy->cpu); |
| __cpufreq_governor(data, |
| CPUFREQ_GOV_POLICY_EXIT); |
| lock_policy_rwsem_write(policy->cpu); |
| } |
| |
| /* start new governor */ |
| data->governor = policy->governor; |
| if (!__cpufreq_governor(data, CPUFREQ_GOV_POLICY_INIT)) { |
| if (!__cpufreq_governor(data, CPUFREQ_GOV_START)) { |
| failed = 0; |
| } else { |
| unlock_policy_rwsem_write(policy->cpu); |
| __cpufreq_governor(data, |
| CPUFREQ_GOV_POLICY_EXIT); |
| lock_policy_rwsem_write(policy->cpu); |
| } |
| } |
| |
| if (failed) { |
| /* new governor failed, so re-start old one */ |
| pr_debug("starting governor %s failed\n", |
| data->governor->name); |
| if (old_gov) { |
| data->governor = old_gov; |
| __cpufreq_governor(data, |
| CPUFREQ_GOV_POLICY_INIT); |
| __cpufreq_governor(data, |
| CPUFREQ_GOV_START); |
| } |
| ret = -EINVAL; |
| goto error_out; |
| } |
| /* might be a policy change, too, so fall through */ |
| } |
| pr_debug("governor: change or update limits\n"); |
| __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
| } |
| |
| error_out: |
| return ret; |
| } |
| |
| /** |
| * cpufreq_update_policy - re-evaluate an existing cpufreq policy |
| * @cpu: CPU which shall be re-evaluated |
| * |
| * Useful for policy notifiers which have different necessities |
| * at different times. |
| */ |
| int cpufreq_update_policy(unsigned int cpu) |
| { |
| struct cpufreq_policy *data = cpufreq_cpu_get(cpu); |
| struct cpufreq_policy policy; |
| int ret; |
| |
| if (!data) { |
| ret = -ENODEV; |
| goto no_policy; |
| } |
| |
| if (unlikely(lock_policy_rwsem_write(cpu))) { |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| pr_debug("updating policy for CPU %u\n", cpu); |
| memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
| policy.min = data->user_policy.min; |
| policy.max = data->user_policy.max; |
| policy.policy = data->user_policy.policy; |
| policy.governor = data->user_policy.governor; |
| |
| /* BIOS might change freq behind our back |
| -> ask driver for current freq and notify governors about a change */ |
| if (cpufreq_driver->get) { |
| policy.cur = cpufreq_driver->get(cpu); |
| if (!data->cur) { |
| pr_debug("Driver did not initialize current freq"); |
| data->cur = policy.cur; |
| } else { |
| if (data->cur != policy.cur && cpufreq_driver->target) |
| cpufreq_out_of_sync(cpu, data->cur, |
| policy.cur); |
| } |
| } |
| |
| ret = __cpufreq_set_policy(data, &policy); |
| |
| unlock_policy_rwsem_write(cpu); |
| |
| fail: |
| cpufreq_cpu_put(data); |
| no_policy: |
| return ret; |
| } |
| EXPORT_SYMBOL(cpufreq_update_policy); |
| |
| static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
| unsigned long action, void *hcpu) |
| { |
| unsigned int cpu = (unsigned long)hcpu; |
| struct device *dev; |
| |
| dev = get_cpu_device(cpu); |
| if (dev) { |
| switch (action) { |
| case CPU_ONLINE: |
| cpufreq_add_dev(dev, NULL); |
| break; |
| case CPU_DOWN_PREPARE: |
| case CPU_UP_CANCELED_FROZEN: |
| __cpufreq_remove_dev(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, |
| }; |
| |
| /********************************************************************* |
| * REGISTER / UNREGISTER CPUFREQ DRIVER * |
| *********************************************************************/ |
| |
| /** |
| * cpufreq_register_driver - register a CPU Frequency driver |
| * @driver_data: A struct cpufreq_driver containing the values# |
| * submitted by the CPU Frequency driver. |
| * |
| * Registers a CPU Frequency driver to this core code. This code |
| * returns zero on success, -EBUSY when another driver got here first |
| * (and isn't unregistered in the meantime). |
| * |
| */ |
| int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
| { |
| unsigned long flags; |
| int ret; |
| |
| if (cpufreq_disabled()) |
| return -ENODEV; |
| |
| if (!driver_data || !driver_data->verify || !driver_data->init || |
| ((!driver_data->setpolicy) && (!driver_data->target))) |
| return -EINVAL; |
| |
| pr_debug("trying to register driver %s\n", driver_data->name); |
| |
| if (driver_data->setpolicy) |
| driver_data->flags |= CPUFREQ_CONST_LOOPS; |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| if (cpufreq_driver) { |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| return -EBUSY; |
| } |
| cpufreq_driver = driver_data; |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| ret = subsys_interface_register(&cpufreq_interface); |
| if (ret) |
| goto err_null_driver; |
| |
| if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
| int i; |
| ret = -ENODEV; |
| |
| /* check for at least one working CPU */ |
| for (i = 0; i < nr_cpu_ids; i++) |
| if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { |
| ret = 0; |
| break; |
| } |
| |
| /* if all ->init() calls failed, unregister */ |
| if (ret) { |
| pr_debug("no CPU initialized for driver %s\n", |
| driver_data->name); |
| goto err_if_unreg; |
| } |
| } |
| |
| register_hotcpu_notifier(&cpufreq_cpu_notifier); |
| pr_debug("driver %s up and running\n", driver_data->name); |
| |
| return 0; |
| err_if_unreg: |
| subsys_interface_unregister(&cpufreq_interface); |
| err_null_driver: |
| 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); |
| unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
| |
| write_lock_irqsave(&cpufreq_driver_lock, flags); |
| cpufreq_driver = NULL; |
| write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); |
| |
| static int __init cpufreq_core_init(void) |
| { |
| int cpu; |
| |
| if (cpufreq_disabled()) |
| return -ENODEV; |
| |
| for_each_possible_cpu(cpu) { |
| per_cpu(cpufreq_policy_cpu, cpu) = -1; |
| init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
| } |
| |
| cpufreq_global_kobject = kobject_create(); |
| BUG_ON(!cpufreq_global_kobject); |
| register_syscore_ops(&cpufreq_syscore_ops); |
| |
| return 0; |
| } |
| core_initcall(cpufreq_core_init); |