diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/cpufreq/cpufreq.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/cpufreq/cpufreq.c | 1939 |
1 files changed, 0 insertions, 1939 deletions
diff --git a/ANDROID_3.4.5/drivers/cpufreq/cpufreq.c b/ANDROID_3.4.5/drivers/cpufreq/cpufreq.c deleted file mode 100644 index 7f2f149a..00000000 --- a/ANDROID_3.4.5/drivers/cpufreq/cpufreq.c +++ /dev/null @@ -1,1939 +0,0 @@ -/* - * 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. - * - */ - -#include <linux/kernel.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/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_SPINLOCK(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: - * - All holders of the lock should check to make sure that the CPU they - * are concerned with are online after they get the lock. - * - 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)); \ - if (unlikely(!cpu_online(cpu))) { \ - up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ - return -1; \ - } \ - \ - return 0; \ -} - -lock_policy_rwsem(read, cpu); - -lock_policy_rwsem(write, cpu); - -static void unlock_policy_rwsem_read(int cpu) -{ - int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); - BUG_ON(policy_cpu == -1); - up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); -} - -static void unlock_policy_rwsem_write(int cpu) -{ - int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); - BUG_ON(policy_cpu == -1); - up_write(&per_cpu(cpu_policy_rwsem, policy_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; -int cpufreq_disabled(void) -{ - return off; -} -void disable_cpufreq(void) -{ - off = 1; -} -static LIST_HEAD(cpufreq_governor_list); -static DEFINE_MUTEX(cpufreq_governor_mutex); - -struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) -{ - struct cpufreq_policy *data; - unsigned long flags; - - if (cpu >= nr_cpu_ids) - goto err_out; - - /* get the cpufreq driver */ - spin_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 (!kobject_get(&data->kobj)) - goto err_out_put_module; - - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - return data; - -err_out_put_module: - module_put(cpufreq_driver->owner); -err_out_unlock: - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); -err_out: - return NULL; -} -EXPORT_SYMBOL_GPL(cpufreq_cpu_get); - - -void cpufreq_cpu_put(struct cpufreq_policy *data) -{ - kobject_put(&data->kobj); - module_put(cpufreq_driver->owner); -} -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. - */ -#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 - - -/** - * 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_freqs *freqs, unsigned int state) -{ - struct cpufreq_policy *policy; - - BUG_ON(irqs_disabled()); - - freqs->flags = cpufreq_driver->flags; - pr_debug("notification %u of frequency transition to %u kHz\n", - state, freqs->new); - - policy = per_cpu(cpufreq_cpu_data, freqs->cpu); - 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_power_frequency(POWER_PSTATE, freqs->new, 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; - } -} -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 = -EINVAL; \ - 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_LEN, "%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 = -EINVAL; - 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_LEN, "%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_LEN, "%s ", t->name); - } -out: - i += sprintf(&buf[i], "\n"); - return i; -} - -static ssize_t show_cpus(const struct cpumask *mask, char *buf) -{ - ssize_t i = 0; - unsigned int cpu; - - for_each_cpu(cpu, mask) { - if (i) - i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); - i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); - if (i >= (PAGE_SIZE - 5)) - break; - } - i += sprintf(&buf[i], "\n"); - return i; -} - -/** - * show_related_cpus - show the CPUs affected by each transition even if - * hw coordination is in use - */ -static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) -{ - if (cpumask_empty(policy->related_cpus)) - return show_cpus(policy->cpus, buf); - return show_cpus(policy->related_cpus, buf); -} - -/** - * show_affected_cpus - show the CPUs affected by each transition - */ -static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) -{ - return show_cpus(policy->cpus, buf); -} - -static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, - const char *buf, size_t count) -{ - unsigned int freq = 0; - unsigned int ret; - - if (!policy->governor || !policy->governor->store_setspeed) - return -EINVAL; - - ret = sscanf(buf, "%u", &freq); - if (ret != 1) - return -EINVAL; - - policy->governor->store_setspeed(policy, freq); - - return count; -} - -static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) -{ - if (!policy->governor || !policy->governor->show_setspeed) - return sprintf(buf, "<unsupported>\n"); - - return policy->governor->show_setspeed(policy, buf); -} - -/** - * show_scaling_driver - show the current cpufreq HW/BIOS limitation - */ -static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) -{ - unsigned int limit; - int ret; - if (cpufreq_driver->bios_limit) { - ret = cpufreq_driver->bios_limit(policy->cpu, &limit); - if (!ret) - return sprintf(buf, "%u\n", limit); - } - return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); -} - -cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); -cpufreq_freq_attr_ro(cpuinfo_min_freq); -cpufreq_freq_attr_ro(cpuinfo_max_freq); -cpufreq_freq_attr_ro(cpuinfo_transition_latency); -cpufreq_freq_attr_ro(scaling_available_governors); -cpufreq_freq_attr_ro(scaling_driver); -cpufreq_freq_attr_ro(scaling_cur_freq); -cpufreq_freq_attr_ro(bios_limit); -cpufreq_freq_attr_ro(related_cpus); -cpufreq_freq_attr_ro(affected_cpus); -cpufreq_freq_attr_rw(scaling_min_freq); -cpufreq_freq_attr_rw(scaling_max_freq); -cpufreq_freq_attr_rw(scaling_governor); -cpufreq_freq_attr_rw(scaling_setspeed); - -static struct attribute *default_attrs[] = { - &cpuinfo_min_freq.attr, - &cpuinfo_max_freq.attr, - &cpuinfo_transition_latency.attr, - &scaling_min_freq.attr, - &scaling_max_freq.attr, - &affected_cpus.attr, - &related_cpus.attr, - &scaling_governor.attr, - &scaling_driver.attr, - &scaling_available_governors.attr, - &scaling_setspeed.attr, - NULL -}; - -struct kobject *cpufreq_global_kobject; -EXPORT_SYMBOL(cpufreq_global_kobject); - -#define to_policy(k) container_of(k, struct cpufreq_policy, kobj) -#define to_attr(a) container_of(a, struct freq_attr, attr) - -static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) -{ - struct cpufreq_policy *policy = to_policy(kobj); - struct freq_attr *fattr = to_attr(attr); - ssize_t ret = -EINVAL; - policy = cpufreq_cpu_get(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(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(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(policy); -no_policy: - return ret; -} - -static void cpufreq_sysfs_release(struct kobject *kobj) -{ - struct cpufreq_policy *policy = to_policy(kobj); - pr_debug("last reference is dropped\n"); - complete(&policy->kobj_unregister); -} - -static const struct sysfs_ops sysfs_ops = { - .show = show, - .store = store, -}; - -static struct kobj_type ktype_cpufreq = { - .sysfs_ops = &sysfs_ops, - .default_attrs = default_attrs, - .release = cpufreq_sysfs_release, -}; - -/* - * Returns: - * Negative: Failure - * 0: Success - * Positive: When we have a managed CPU and the sysfs got symlinked - */ -static int cpufreq_add_dev_policy(unsigned int cpu, - struct cpufreq_policy *policy, - struct device *dev) -{ - int ret = 0; -#ifdef CONFIG_SMP - unsigned long flags; - unsigned int j; -#ifdef CONFIG_HOTPLUG_CPU - struct cpufreq_governor *gov; - - gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); - if (gov) { - policy->governor = gov; - pr_debug("Restoring governor %s for cpu %d\n", - policy->governor->name, cpu); - } -#endif - - for_each_cpu(j, policy->cpus) { - struct cpufreq_policy *managed_policy; - - if (cpu == j) - continue; - - /* Check for existing affected CPUs. - * They may not be aware of it due to CPU Hotplug. - * cpufreq_cpu_put is called when the device is removed - * in __cpufreq_remove_dev() - */ - managed_policy = cpufreq_cpu_get(j); - if (unlikely(managed_policy)) { - - /* Set proper policy_cpu */ - unlock_policy_rwsem_write(cpu); - per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu; - - if (lock_policy_rwsem_write(cpu) < 0) { - /* Should not go through policy unlock path */ - if (cpufreq_driver->exit) - cpufreq_driver->exit(policy); - cpufreq_cpu_put(managed_policy); - return -EBUSY; - } - - spin_lock_irqsave(&cpufreq_driver_lock, flags); - cpumask_copy(managed_policy->cpus, policy->cpus); - per_cpu(cpufreq_cpu_data, cpu) = managed_policy; - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - - pr_debug("CPU already managed, adding link\n"); - ret = sysfs_create_link(&dev->kobj, - &managed_policy->kobj, - "cpufreq"); - if (ret) - cpufreq_cpu_put(managed_policy); - /* - * Success. We only needed to be added to the mask. - * Call driver->exit() because only the cpu parent of - * the kobj needed to call init(). - */ - if (cpufreq_driver->exit) - cpufreq_driver->exit(policy); - - if (!ret) - return 1; - else - return ret; - } - } -#endif - return ret; -} - - -/* symlink affected CPUs */ -static int cpufreq_add_dev_symlink(unsigned int cpu, - struct cpufreq_policy *policy) -{ - unsigned int j; - int ret = 0; - - for_each_cpu(j, policy->cpus) { - struct cpufreq_policy *managed_policy; - struct device *cpu_dev; - - if (j == cpu) - continue; - if (!cpu_online(j)) - continue; - - pr_debug("CPU %u already managed, adding link\n", j); - managed_policy = cpufreq_cpu_get(cpu); - cpu_dev = get_cpu_device(j); - ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, - "cpufreq"); - if (ret) { - cpufreq_cpu_put(managed_policy); - return ret; - } - } - return ret; -} - -static int cpufreq_add_dev_interface(unsigned int cpu, - struct cpufreq_policy *policy, - struct device *dev) -{ - struct cpufreq_policy new_policy; - struct freq_attr **drv_attr; - unsigned long flags; - int ret = 0; - unsigned int j; - - /* prepare interface data */ - ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, - &dev->kobj, "cpufreq"); - if (ret) - return ret; - - /* set up files for this cpu device */ - drv_attr = cpufreq_driver->attr; - while ((drv_attr) && (*drv_attr)) { - ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); - if (ret) - goto err_out_kobj_put; - drv_attr++; - } - if (cpufreq_driver->get) { - ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); - if (ret) - goto err_out_kobj_put; - } - if (cpufreq_driver->target) { - ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); - if (ret) - goto err_out_kobj_put; - } - if (cpufreq_driver->bios_limit) { - ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); - if (ret) - goto err_out_kobj_put; - } - - spin_lock_irqsave(&cpufreq_driver_lock, flags); - for_each_cpu(j, policy->cpus) { - if (!cpu_online(j)) - continue; - per_cpu(cpufreq_cpu_data, j) = policy; - per_cpu(cpufreq_policy_cpu, j) = policy->cpu; - } - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - - ret = cpufreq_add_dev_symlink(cpu, policy); - if (ret) - goto err_out_kobj_put; - - memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); - /* assure that the starting sequence is run in __cpufreq_set_policy */ - policy->governor = NULL; - - /* set default policy */ - ret = __cpufreq_set_policy(policy, &new_policy); - policy->user_policy.policy = policy->policy; - policy->user_policy.governor = policy->governor; - - if (ret) { - pr_debug("setting policy failed\n"); - if (cpufreq_driver->exit) - cpufreq_driver->exit(policy); - } - return ret; - -err_out_kobj_put: - kobject_put(&policy->kobj); - wait_for_completion(&policy->kobj_unregister); - return ret; -} - - -/** - * cpufreq_add_dev - add a CPU device - * - * Adds the cpufreq interface for a CPU device. - * - * The Oracle says: try running cpufreq registration/unregistration concurrently - * with with cpu hotplugging and all hell will break loose. Tried to clean this - * mess up, but more thorough testing is needed. - Mathieu - */ -static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) -{ - unsigned int cpu = dev->id; - int ret = 0, found = 0; - struct cpufreq_policy *policy; - unsigned long flags; - unsigned int j; -#ifdef CONFIG_HOTPLUG_CPU - int sibling; -#endif - - if (cpu_is_offline(cpu)) - return 0; - - pr_debug("adding CPU %u\n", cpu); - -#ifdef CONFIG_SMP - /* check whether a different CPU already registered this - * CPU because it is in the same boat. */ - policy = cpufreq_cpu_get(cpu); - if (unlikely(policy)) { - cpufreq_cpu_put(policy); - return 0; - } -#endif - - if (!try_module_get(cpufreq_driver->owner)) { - ret = -EINVAL; - goto module_out; - } - - ret = -ENOMEM; - policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); - if (!policy) - goto nomem_out; - - if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) - goto err_free_policy; - - if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) - goto err_free_cpumask; - - policy->cpu = cpu; - cpumask_copy(policy->cpus, cpumask_of(cpu)); - - /* Initially set CPU itself as the policy_cpu */ - per_cpu(cpufreq_policy_cpu, cpu) = cpu; - ret = (lock_policy_rwsem_write(cpu) < 0); - WARN_ON(ret); - - init_completion(&policy->kobj_unregister); - INIT_WORK(&policy->update, handle_update); - - /* Set governor before ->init, so that driver could check it */ -#ifdef CONFIG_HOTPLUG_CPU - for_each_online_cpu(sibling) { - struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); - if (cp && cp->governor && - (cpumask_test_cpu(cpu, cp->related_cpus))) { - policy->governor = cp->governor; - found = 1; - break; - } - } -#endif - if (!found) - policy->governor = CPUFREQ_DEFAULT_GOVERNOR; - /* call driver. From then on the cpufreq must be able - * to accept all calls to ->verify and ->setpolicy for this CPU - */ - ret = cpufreq_driver->init(policy); - if (ret) { - pr_debug("initialization failed\n"); - goto err_unlock_policy; - } - policy->user_policy.min = policy->min; - policy->user_policy.max = policy->max; - - blocking_notifier_call_chain(&cpufreq_policy_notifier_list, - CPUFREQ_START, policy); - - ret = cpufreq_add_dev_policy(cpu, policy, dev); - if (ret) { - if (ret > 0) - /* This is a managed cpu, symlink created, - exit with 0 */ - ret = 0; - goto err_unlock_policy; - } - - ret = cpufreq_add_dev_interface(cpu, policy, dev); - if (ret) - goto err_out_unregister; - - unlock_policy_rwsem_write(cpu); - - kobject_uevent(&policy->kobj, KOBJ_ADD); - module_put(cpufreq_driver->owner); - pr_debug("initialization complete\n"); - - return 0; - - -err_out_unregister: - spin_lock_irqsave(&cpufreq_driver_lock, flags); - for_each_cpu(j, policy->cpus) - per_cpu(cpufreq_cpu_data, j) = NULL; - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - - kobject_put(&policy->kobj); - wait_for_completion(&policy->kobj_unregister); - -err_unlock_policy: - unlock_policy_rwsem_write(cpu); - free_cpumask_var(policy->related_cpus); -err_free_cpumask: - free_cpumask_var(policy->cpus); -err_free_policy: - kfree(policy); -nomem_out: - module_put(cpufreq_driver->owner); -module_out: - return ret; -} - - -/** - * __cpufreq_remove_dev - remove a CPU device - * - * Removes the cpufreq interface for a CPU device. - * Caller should already have policy_rwsem in write mode for this CPU. - * This routine frees the rwsem before returning. - */ -static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) -{ - unsigned int cpu = dev->id; - unsigned long flags; - struct cpufreq_policy *data; - struct kobject *kobj; - struct completion *cmp; -#ifdef CONFIG_SMP - struct device *cpu_dev; - unsigned int j; -#endif - - pr_debug("unregistering CPU %u\n", cpu); - - spin_lock_irqsave(&cpufreq_driver_lock, flags); - data = per_cpu(cpufreq_cpu_data, cpu); - - if (!data) { - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - unlock_policy_rwsem_write(cpu); - return -EINVAL; - } - per_cpu(cpufreq_cpu_data, cpu) = NULL; - - -#ifdef CONFIG_SMP - /* if this isn't the CPU which is the parent of the kobj, we - * only need to unlink, put and exit - */ - if (unlikely(cpu != data->cpu)) { - pr_debug("removing link\n"); - cpumask_clear_cpu(cpu, data->cpus); - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - kobj = &dev->kobj; - cpufreq_cpu_put(data); - unlock_policy_rwsem_write(cpu); - sysfs_remove_link(kobj, "cpufreq"); - return 0; - } -#endif - -#ifdef CONFIG_SMP - -#ifdef CONFIG_HOTPLUG_CPU - strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, - CPUFREQ_NAME_LEN); -#endif - - /* if we have other CPUs still registered, we need to unlink them, - * or else wait_for_completion below will lock up. Clean the - * per_cpu(cpufreq_cpu_data) while holding the lock, and remove - * the sysfs links afterwards. - */ - if (unlikely(cpumask_weight(data->cpus) > 1)) { - for_each_cpu(j, data->cpus) { - if (j == cpu) - continue; - per_cpu(cpufreq_cpu_data, j) = NULL; - } - } - - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - - if (unlikely(cpumask_weight(data->cpus) > 1)) { - for_each_cpu(j, data->cpus) { - if (j == cpu) - continue; - pr_debug("removing link for cpu %u\n", j); -#ifdef CONFIG_HOTPLUG_CPU - strncpy(per_cpu(cpufreq_cpu_governor, j), - data->governor->name, CPUFREQ_NAME_LEN); -#endif - cpu_dev = get_cpu_device(j); - kobj = &cpu_dev->kobj; - unlock_policy_rwsem_write(cpu); - sysfs_remove_link(kobj, "cpufreq"); - lock_policy_rwsem_write(cpu); - cpufreq_cpu_put(data); - } - } -#else - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); -#endif - - if (cpufreq_driver->target) - __cpufreq_governor(data, CPUFREQ_GOV_STOP); - - kobj = &data->kobj; - cmp = &data->kobj_unregister; - unlock_policy_rwsem_write(cpu); - kobject_put(kobj); - - /* we need to make sure that the underlying kobj is actually - * not referenced anymore by anybody before we proceed with - * unloading. - */ - pr_debug("waiting for dropping of refcount\n"); - wait_for_completion(cmp); - pr_debug("wait complete\n"); - - lock_policy_rwsem_write(cpu); - if (cpufreq_driver->exit) - cpufreq_driver->exit(data); - unlock_policy_rwsem_write(cpu); - -#ifdef CONFIG_HOTPLUG_CPU - /* when the CPU which is the parent of the kobj is hotplugged - * offline, check for siblings, and create cpufreq sysfs interface - * and symlinks - */ - if (unlikely(cpumask_weight(data->cpus) > 1)) { - /* first sibling now owns the new sysfs dir */ - cpumask_clear_cpu(cpu, data->cpus); - cpufreq_add_dev(get_cpu_device(cpumask_first(data->cpus)), NULL); - - /* finally remove our own symlink */ - lock_policy_rwsem_write(cpu); - __cpufreq_remove_dev(dev, sif); - } -#endif - - free_cpumask_var(data->related_cpus); - free_cpumask_var(data->cpus); - kfree(data); - - return 0; -} - - -static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) -{ - unsigned int cpu = dev->id; - int retval; - - if (cpu_is_offline(cpu)) - return 0; - - if (unlikely(lock_policy_rwsem_write(cpu))) - BUG(); - - retval = __cpufreq_remove_dev(dev, sif); - return retval; -} - - -static void handle_update(struct work_struct *work) -{ - struct cpufreq_policy *policy = - container_of(work, struct cpufreq_policy, update); - unsigned int cpu = policy->cpu; - pr_debug("handle_update for cpu %u called\n", cpu); - cpufreq_update_policy(cpu); -} - -/** - * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. - * @cpu: cpu number - * @old_freq: CPU frequency the kernel thinks the CPU runs at - * @new_freq: CPU frequency the CPU actually runs at - * - * We adjust to current frequency first, and need to clean up later. - * So either call to cpufreq_update_policy() or schedule handle_update()). - */ -static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, - unsigned int new_freq) -{ - struct cpufreq_freqs freqs; - - pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " - "core thinks of %u, is %u kHz.\n", old_freq, new_freq); - - freqs.cpu = cpu; - freqs.old = old_freq; - freqs.new = new_freq; - cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); - cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); -} - - -/** - * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur - * @cpu: CPU number - * - * This is the last known freq, without actually getting it from the driver. - * Return value will be same as what is shown in scaling_cur_freq in sysfs. - */ -unsigned int cpufreq_quick_get(unsigned int cpu) -{ - struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); - unsigned int ret_freq = 0; - - if (policy) { - ret_freq = policy->cur; - cpufreq_cpu_put(policy); - } - - return ret_freq; -} -EXPORT_SYMBOL(cpufreq_quick_get); - -/** - * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU - * @cpu: CPU number - * - * Just return the max possible frequency for a given CPU. - */ -unsigned int cpufreq_quick_get_max(unsigned int cpu) -{ - struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); - unsigned int ret_freq = 0; - - if (policy) { - ret_freq = policy->max; - cpufreq_cpu_put(policy); - } - - return ret_freq; -} -EXPORT_SYMBOL(cpufreq_quick_get_max); - - -static unsigned int __cpufreq_get(unsigned int cpu) -{ - struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); - unsigned int ret_freq = 0; - - if (!cpufreq_driver->get) - return ret_freq; - - ret_freq = cpufreq_driver->get(cpu); - - if (ret_freq && policy->cur && - !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { - /* verify no discrepancy between actual and - saved value exists */ - if (unlikely(ret_freq != policy->cur)) { - cpufreq_out_of_sync(cpu, policy->cur, ret_freq); - schedule_work(&policy->update); - } - } - - return ret_freq; -} - -/** - * cpufreq_get - get the current CPU frequency (in kHz) - * @cpu: CPU number - * - * Get the CPU current (static) CPU frequency - */ -unsigned int cpufreq_get(unsigned int cpu) -{ - unsigned int ret_freq = 0; - struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); - - if (!policy) - goto out; - - if (unlikely(lock_policy_rwsem_read(cpu))) - goto out_policy; - - ret_freq = __cpufreq_get(cpu); - - unlock_policy_rwsem_read(cpu); - -out_policy: - cpufreq_cpu_put(policy); -out: - return ret_freq; -} -EXPORT_SYMBOL(cpufreq_get); - -static struct subsys_interface cpufreq_interface = { - .name = "cpufreq", - .subsys = &cpu_subsys, - .add_dev = cpufreq_add_dev, - .remove_dev = cpufreq_remove_dev, -}; - - -/** - * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. - * - * This function is only executed for the boot processor. The other CPUs - * have been put offline by means of CPU hotplug. - */ -static int cpufreq_bp_suspend(void) -{ - int ret = 0; - - int cpu = smp_processor_id(); - struct cpufreq_policy *cpu_policy; - - pr_debug("suspending cpu %u\n", cpu); - - /* If there's no policy for the boot CPU, we have nothing to do. */ - cpu_policy = cpufreq_cpu_get(cpu); - if (!cpu_policy) - return 0; - - if (cpufreq_driver->suspend) { - ret = cpufreq_driver->suspend(cpu_policy); - if (ret) - printk(KERN_ERR "cpufreq: suspend failed in ->suspend " - "step on CPU %u\n", cpu_policy->cpu); - } - - cpufreq_cpu_put(cpu_policy); - return ret; -} - -/** - * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. - * - * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) - * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are - * restored. It will verify that the current freq is in sync with - * what we believe it to be. This is a bit later than when it - * should be, but nonethteless it's better than calling - * cpufreq_driver->get() here which might re-enable interrupts... - * - * This function is only executed for the boot CPU. The other CPUs have not - * been turned on yet. - */ -static void cpufreq_bp_resume(void) -{ - int ret = 0; - - int cpu = smp_processor_id(); - struct cpufreq_policy *cpu_policy; - - pr_debug("resuming cpu %u\n", cpu); - - /* If there's no policy for the boot CPU, we have nothing to do. */ - cpu_policy = cpufreq_cpu_get(cpu); - if (!cpu_policy) - return; - - if (cpufreq_driver->resume) { - ret = cpufreq_driver->resume(cpu_policy); - if (ret) { - printk(KERN_ERR "cpufreq: resume failed in ->resume " - "step on CPU %u\n", cpu_policy->cpu); - goto fail; - } - } - - schedule_work(&cpu_policy->update); - -fail: - cpufreq_cpu_put(cpu_policy); -} - -static struct syscore_ops cpufreq_syscore_ops = { - .suspend = cpufreq_bp_suspend, - .resume = cpufreq_bp_resume, -}; - - -/********************************************************************* - * NOTIFIER LISTS INTERFACE * - *********************************************************************/ - -/** - * cpufreq_register_notifier - register a driver with cpufreq - * @nb: notifier function to register - * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER - * - * Add a driver to one of two lists: either a list of drivers that - * are notified about clock rate changes (once before and once after - * the transition), or a list of drivers that are notified about - * changes in cpufreq policy. - * - * This function may sleep, and has the same return conditions as - * blocking_notifier_chain_register. - */ -int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) -{ - int ret; - - WARN_ON(!init_cpufreq_transition_notifier_list_called); - - switch (list) { - case CPUFREQ_TRANSITION_NOTIFIER: - ret = srcu_notifier_chain_register( - &cpufreq_transition_notifier_list, nb); - break; - case CPUFREQ_POLICY_NOTIFIER: - ret = blocking_notifier_chain_register( - &cpufreq_policy_notifier_list, nb); - break; - default: - ret = -EINVAL; - } - - return ret; -} -EXPORT_SYMBOL(cpufreq_register_notifier); - - -/** - * cpufreq_unregister_notifier - unregister a driver with cpufreq - * @nb: notifier block to be unregistered - * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER - * - * Remove a driver from the CPU frequency notifier list. - * - * This function may sleep, and has the same return conditions as - * blocking_notifier_chain_unregister. - */ -int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) -{ - int ret; - - switch (list) { - case CPUFREQ_TRANSITION_NOTIFIER: - ret = srcu_notifier_chain_unregister( - &cpufreq_transition_notifier_list, nb); - break; - case CPUFREQ_POLICY_NOTIFIER: - ret = blocking_notifier_chain_unregister( - &cpufreq_policy_notifier_list, nb); - break; - default: - ret = -EINVAL; - } - - return ret; -} -EXPORT_SYMBOL(cpufreq_unregister_notifier); - - -/********************************************************************* - * GOVERNORS * - *********************************************************************/ - - -int __cpufreq_driver_target(struct cpufreq_policy *policy, - unsigned int target_freq, - unsigned int relation) -{ - int retval = -EINVAL; - - if (cpufreq_disabled()) - return -ENODEV; - - pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu, - target_freq, relation); - if (cpu_online(policy->cpu) && cpufreq_driver->target) - retval = cpufreq_driver->target(policy, target_freq, relation); - - return retval; -} -EXPORT_SYMBOL_GPL(__cpufreq_driver_target); - -int cpufreq_driver_target(struct cpufreq_policy *policy, - unsigned int target_freq, - unsigned int relation) -{ - int ret = -EINVAL; - - policy = cpufreq_cpu_get(policy->cpu); - if (!policy) - goto no_policy; - - if (unlikely(lock_policy_rwsem_write(policy->cpu))) - goto fail; - - ret = __cpufreq_driver_target(policy, target_freq, relation); - - unlock_policy_rwsem_write(policy->cpu); - -fail: - cpufreq_cpu_put(policy); -no_policy: - return ret; -} -EXPORT_SYMBOL_GPL(cpufreq_driver_target); - -int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) -{ - int ret = 0; - - policy = cpufreq_cpu_get(policy->cpu); - if (!policy) - return -EINVAL; - - if (cpu_online(cpu) && cpufreq_driver->getavg) - ret = cpufreq_driver->getavg(policy, cpu); - - cpufreq_cpu_put(policy); - return ret; -} -EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); - -/* - * when "event" is CPUFREQ_GOV_LIMITS - */ - -static int __cpufreq_governor(struct cpufreq_policy *policy, - unsigned int event) -{ - int ret; - - /* Only must be defined when default governor is known to have latency - restrictions, like e.g. conservative or ondemand. - That this is the case is already ensured in Kconfig - */ -#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE - struct cpufreq_governor *gov = &cpufreq_gov_performance; -#else - struct cpufreq_governor *gov = NULL; -#endif - - if (policy->governor->max_transition_latency && - policy->cpuinfo.transition_latency > - policy->governor->max_transition_latency) { - if (!gov) - return -EINVAL; - else { - printk(KERN_WARNING "%s governor failed, too long" - " transition latency of HW, fallback" - " to %s governor\n", - policy->governor->name, - gov->name); - policy->governor = gov; - } - } - - if (!try_module_get(policy->governor->owner)) - return -EINVAL; - - pr_debug("__cpufreq_governor for CPU %u, event %u\n", - policy->cpu, event); - ret = policy->governor->governor(policy, event); - - /* we keep one module reference alive for - each CPU governed by this CPU */ - if ((event != CPUFREQ_GOV_START) || ret) - module_put(policy->governor->owner); - if ((event == CPUFREQ_GOV_STOP) && !ret) - module_put(policy->governor->owner); - - return ret; -} - - -int cpufreq_register_governor(struct cpufreq_governor *governor) -{ - int err; - - if (!governor) - return -EINVAL; - - if (cpufreq_disabled()) - return -ENODEV; - - mutex_lock(&cpufreq_governor_mutex); - - err = -EBUSY; - if (__find_governor(governor->name) == NULL) { - err = 0; - list_add(&governor->governor_list, &cpufreq_governor_list); - } - - mutex_unlock(&cpufreq_governor_mutex); - return err; -} -EXPORT_SYMBOL_GPL(cpufreq_register_governor); - - -void cpufreq_unregister_governor(struct cpufreq_governor *governor) -{ -#ifdef CONFIG_HOTPLUG_CPU - int cpu; -#endif - - if (!governor) - return; - - if (cpufreq_disabled()) - return; - -#ifdef CONFIG_HOTPLUG_CPU - for_each_present_cpu(cpu) { - if (cpu_online(cpu)) - continue; - if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) - strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); - } -#endif - - mutex_lock(&cpufreq_governor_mutex); - list_del(&governor->governor_list); - mutex_unlock(&cpufreq_governor_mutex); - return; -} -EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); - - - -/********************************************************************* - * POLICY INTERFACE * - *********************************************************************/ - -/** - * cpufreq_get_policy - get the current cpufreq_policy - * @policy: struct cpufreq_policy into which the current cpufreq_policy - * is written - * - * Reads the current cpufreq policy. - */ -int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) -{ - struct cpufreq_policy *cpu_policy; - if (!policy) - return -EINVAL; - - cpu_policy = cpufreq_cpu_get(cpu); - if (!cpu_policy) - return -EINVAL; - - memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); - - cpufreq_cpu_put(cpu_policy); - return 0; -} -EXPORT_SYMBOL(cpufreq_get_policy); - - -/* - * data : current policy. - * policy : policy to be set. - */ -static int __cpufreq_set_policy(struct cpufreq_policy *data, - struct cpufreq_policy *policy) -{ - int ret = 0; - - pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, - policy->min, policy->max); - - memcpy(&policy->cpuinfo, &data->cpuinfo, - sizeof(struct cpufreq_cpuinfo)); - - if (policy->min > data->max || policy->max < data->min) { - ret = -EINVAL; - goto error_out; - } - - /* verify the cpu speed can be set within this limit */ - ret = cpufreq_driver->verify(policy); - if (ret) - goto error_out; - - /* adjust if necessary - all reasons */ - blocking_notifier_call_chain(&cpufreq_policy_notifier_list, - CPUFREQ_ADJUST, policy); - - /* adjust if necessary - hardware incompatibility*/ - blocking_notifier_call_chain(&cpufreq_policy_notifier_list, - CPUFREQ_INCOMPATIBLE, policy); - - /* verify the cpu speed can be set within this limit, - which might be different to the first one */ - ret = cpufreq_driver->verify(policy); - if (ret) - goto error_out; - - /* notification of the new policy */ - blocking_notifier_call_chain(&cpufreq_policy_notifier_list, - CPUFREQ_NOTIFY, policy); - - data->min = policy->min; - data->max = policy->max; - - pr_debug("new min and max freqs are %u - %u kHz\n", - data->min, data->max); - - if (cpufreq_driver->setpolicy) { - data->policy = policy->policy; - pr_debug("setting range\n"); - ret = cpufreq_driver->setpolicy(policy); - } else { - if (policy->governor != data->governor) { - /* save old, working values */ - struct cpufreq_governor *old_gov = data->governor; - - pr_debug("governor switch\n"); - - /* end old governor */ - if (data->governor) - __cpufreq_governor(data, CPUFREQ_GOV_STOP); - - /* start new governor */ - data->governor = policy->governor; - if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { - /* new governor failed, so re-start old one */ - pr_debug("starting governor %s failed\n", - data->governor->name); - if (old_gov) { - data->governor = old_gov; - __cpufreq_governor(data, - CPUFREQ_GOV_START); - } - ret = -EINVAL; - goto error_out; - } - /* might be a policy change, too, so fall through */ - } - pr_debug("governor: change or update limits\n"); - __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); - } - -error_out: - return ret; -} - -/** - * cpufreq_update_policy - re-evaluate an existing cpufreq policy - * @cpu: CPU which shall be re-evaluated - * - * Useful for policy notifiers which have different necessities - * at different times. - */ -int cpufreq_update_policy(unsigned int cpu) -{ - struct cpufreq_policy *data = cpufreq_cpu_get(cpu); - struct cpufreq_policy policy; - int ret; - - if (!data) { - ret = -ENODEV; - goto no_policy; - } - - if (unlikely(lock_policy_rwsem_write(cpu))) { - ret = -EINVAL; - goto fail; - } - - pr_debug("updating policy for CPU %u\n", cpu); - memcpy(&policy, data, sizeof(struct cpufreq_policy)); - policy.min = data->user_policy.min; - policy.max = data->user_policy.max; - policy.policy = data->user_policy.policy; - policy.governor = data->user_policy.governor; - - /* BIOS might change freq behind our back - -> ask driver for current freq and notify governors about a change */ - if (cpufreq_driver->get) { - policy.cur = cpufreq_driver->get(cpu); - if (!data->cur) { - pr_debug("Driver did not initialize current freq"); - data->cur = policy.cur; - } else { - if (data->cur != policy.cur) - cpufreq_out_of_sync(cpu, data->cur, - policy.cur); - } - } - - ret = __cpufreq_set_policy(data, &policy); - - unlock_policy_rwsem_write(cpu); - -fail: - cpufreq_cpu_put(data); -no_policy: - return ret; -} -EXPORT_SYMBOL(cpufreq_update_policy); - -static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - unsigned int cpu = (unsigned long)hcpu; - struct device *dev; - - dev = get_cpu_device(cpu); - if (dev) { - switch (action) { - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - cpufreq_add_dev(dev, NULL); - break; - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - if (unlikely(lock_policy_rwsem_write(cpu))) - BUG(); - - __cpufreq_remove_dev(dev, NULL); - break; - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - cpufreq_add_dev(dev, NULL); - break; - } - } - return NOTIFY_OK; -} - -static struct notifier_block __refdata cpufreq_cpu_notifier = { - .notifier_call = cpufreq_cpu_callback, -}; - -/********************************************************************* - * REGISTER / UNREGISTER CPUFREQ DRIVER * - *********************************************************************/ - -/** - * cpufreq_register_driver - register a CPU Frequency driver - * @driver_data: A struct cpufreq_driver containing the values# - * submitted by the CPU Frequency driver. - * - * Registers a CPU Frequency driver to this core code. This code - * returns zero on success, -EBUSY when another driver got here first - * (and isn't unregistered in the meantime). - * - */ -int cpufreq_register_driver(struct cpufreq_driver *driver_data) -{ - unsigned long flags; - int ret; - - if (cpufreq_disabled()) - return -ENODEV; - - if (!driver_data || !driver_data->verify || !driver_data->init || - ((!driver_data->setpolicy) && (!driver_data->target))) - return -EINVAL; - - pr_debug("trying to register driver %s\n", driver_data->name); - - if (driver_data->setpolicy) - driver_data->flags |= CPUFREQ_CONST_LOOPS; - - spin_lock_irqsave(&cpufreq_driver_lock, flags); - if (cpufreq_driver) { - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - return -EBUSY; - } - cpufreq_driver = driver_data; - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - - ret = subsys_interface_register(&cpufreq_interface); - if (ret) - goto err_null_driver; - - if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { - int i; - ret = -ENODEV; - - /* check for at least one working CPU */ - for (i = 0; i < nr_cpu_ids; i++) - if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { - ret = 0; - break; - } - - /* if all ->init() calls failed, unregister */ - if (ret) { - pr_debug("no CPU initialized for driver %s\n", - driver_data->name); - goto err_if_unreg; - } - } - - register_hotcpu_notifier(&cpufreq_cpu_notifier); - pr_debug("driver %s up and running\n", driver_data->name); - - return 0; -err_if_unreg: - subsys_interface_unregister(&cpufreq_interface); -err_null_driver: - spin_lock_irqsave(&cpufreq_driver_lock, flags); - cpufreq_driver = NULL; - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - return ret; -} -EXPORT_SYMBOL_GPL(cpufreq_register_driver); - - -/** - * cpufreq_unregister_driver - unregister the current CPUFreq driver - * - * Unregister the current CPUFreq driver. Only call this if you have - * the right to do so, i.e. if you have succeeded in initialising before! - * Returns zero if successful, and -EINVAL if the cpufreq_driver is - * currently not initialised. - */ -int cpufreq_unregister_driver(struct cpufreq_driver *driver) -{ - unsigned long flags; - - if (!cpufreq_driver || (driver != cpufreq_driver)) - return -EINVAL; - - pr_debug("unregistering driver %s\n", driver->name); - - subsys_interface_unregister(&cpufreq_interface); - unregister_hotcpu_notifier(&cpufreq_cpu_notifier); - - spin_lock_irqsave(&cpufreq_driver_lock, flags); - cpufreq_driver = NULL; - spin_unlock_irqrestore(&cpufreq_driver_lock, flags); - - return 0; -} -EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); - -static int __init cpufreq_core_init(void) -{ - int cpu; - - if (cpufreq_disabled()) - return -ENODEV; - - for_each_possible_cpu(cpu) { - per_cpu(cpufreq_policy_cpu, cpu) = -1; - init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); - } - - cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); - BUG_ON(!cpufreq_global_kobject); - register_syscore_ops(&cpufreq_syscore_ops); - - return 0; -} -core_initcall(cpufreq_core_init); |