| /* |
| * 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> |
| |
| #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "cpufreq-core", msg) |
| |
| /** |
| * 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 struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS]; |
| static DEFINE_SPINLOCK(cpufreq_driver_lock); |
| |
| /* internal prototypes */ |
| static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); |
| static void handle_update(void *data); |
| |
| /** |
| * 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 int __init init_cpufreq_transition_notifier_list(void) |
| { |
| srcu_init_notifier_head(&cpufreq_transition_notifier_list); |
| return 0; |
| } |
| core_initcall(init_cpufreq_transition_notifier_list); |
| |
| 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_CPUS) |
| 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 = 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); |
| |
| |
| /********************************************************************* |
| * UNIFIED DEBUG HELPERS * |
| *********************************************************************/ |
| #ifdef CONFIG_CPU_FREQ_DEBUG |
| |
| /* what part(s) of the CPUfreq subsystem are debugged? */ |
| static unsigned int debug; |
| |
| /* is the debug output ratelimit'ed using printk_ratelimit? User can |
| * set or modify this value. |
| */ |
| static unsigned int debug_ratelimit = 1; |
| |
| /* is the printk_ratelimit'ing enabled? It's enabled after a successful |
| * loading of a cpufreq driver, temporarily disabled when a new policy |
| * is set, and disabled upon cpufreq driver removal |
| */ |
| static unsigned int disable_ratelimit = 1; |
| static DEFINE_SPINLOCK(disable_ratelimit_lock); |
| |
| static void cpufreq_debug_enable_ratelimit(void) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&disable_ratelimit_lock, flags); |
| if (disable_ratelimit) |
| disable_ratelimit--; |
| spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
| } |
| |
| static void cpufreq_debug_disable_ratelimit(void) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&disable_ratelimit_lock, flags); |
| disable_ratelimit++; |
| spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
| } |
| |
| void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt, ...) |
| { |
| char s[256]; |
| va_list args; |
| unsigned int len; |
| unsigned long flags; |
| |
| WARN_ON(!prefix); |
| if (type & debug) { |
| spin_lock_irqsave(&disable_ratelimit_lock, flags); |
| if (!disable_ratelimit && debug_ratelimit && !printk_ratelimit()) { |
| spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
| return; |
| } |
| spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
| |
| len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); |
| |
| va_start(args, fmt); |
| len += vsnprintf(&s[len], (256 - len), fmt, args); |
| va_end(args); |
| |
| printk(s); |
| |
| WARN_ON(len < 5); |
| } |
| } |
| EXPORT_SYMBOL(cpufreq_debug_printk); |
| |
| |
| module_param(debug, uint, 0644); |
| MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core, 2 to debug drivers, and 4 to debug governors."); |
| |
| module_param(debug_ratelimit, uint, 0644); |
| MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting."); |
| |
| #else /* !CONFIG_CPU_FREQ_DEBUG */ |
| |
| static inline void cpufreq_debug_enable_ratelimit(void) { return; } |
| static inline void cpufreq_debug_disable_ratelimit(void) { return; } |
| |
| #endif /* CONFIG_CPU_FREQ_DEBUG */ |
| |
| |
| /********************************************************************* |
| * 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; |
| dprintk("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_PRECHANGE && ci->old < ci->new) || |
| (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); |
| dprintk("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; |
| dprintk("notification %u of frequency transition to %u kHz\n", |
| state, freqs->new); |
| |
| policy = 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)) { |
| dprintk("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); |
| 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) { |
| char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", str_governor); |
| |
| if (name) { |
| int ret; |
| |
| mutex_unlock(&cpufreq_governor_mutex); |
| ret = request_module(name); |
| mutex_lock(&cpufreq_governor_mutex); |
| |
| if (ret == 0) |
| t = __find_governor(str_governor); |
| } |
| |
| kfree(name); |
| } |
| |
| if (t != NULL) { |
| *governor = t; |
| err = 0; |
| } |
| |
| mutex_unlock(&cpufreq_governor_mutex); |
| } |
| out: |
| return err; |
| } |
| |
| |
| /* drivers/base/cpu.c */ |
| extern struct sysdev_class cpu_sysdev_class; |
| |
| |
| /** |
| * 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(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; \ |
| \ |
| lock_cpu_hotplug(); \ |
| mutex_lock(&policy->lock); \ |
| ret = __cpufreq_set_policy(policy, &new_policy); \ |
| policy->user_policy.object = policy->object; \ |
| mutex_unlock(&policy->lock); \ |
| unlock_cpu_hotplug(); \ |
| \ |
| 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; |
| |
| lock_cpu_hotplug(); |
| |
| /* Do not use cpufreq_set_policy here or the user_policy.max |
| will be wrongly overridden */ |
| mutex_lock(&policy->lock); |
| ret = __cpufreq_set_policy(policy, &new_policy); |
| |
| policy->user_policy.policy = policy->policy; |
| policy->user_policy.governor = policy->governor; |
| mutex_unlock(&policy->lock); |
| |
| unlock_cpu_hotplug(); |
| |
| return ret ? ret : count; |
| } |
| |
| /** |
| * show_scaling_driver - show the cpufreq driver currently loaded |
| */ |
| static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf) |
| { |
| return scnprintf(buf, CPUFREQ_NAME_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; |
| } |
| /** |
| * show_affected_cpus - show the CPUs affected by each transition |
| */ |
| static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf) |
| { |
| ssize_t i = 0; |
| unsigned int cpu; |
| |
| for_each_cpu_mask(cpu, policy->cpus) { |
| 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; |
| } |
| |
| |
| #define define_one_ro(_name) \ |
| static struct freq_attr _name = \ |
| __ATTR(_name, 0444, show_##_name, NULL) |
| |
| #define define_one_ro0400(_name) \ |
| static struct freq_attr _name = \ |
| __ATTR(_name, 0400, show_##_name, NULL) |
| |
| #define define_one_rw(_name) \ |
| static struct freq_attr _name = \ |
| __ATTR(_name, 0644, show_##_name, store_##_name) |
| |
| define_one_ro0400(cpuinfo_cur_freq); |
| define_one_ro(cpuinfo_min_freq); |
| define_one_ro(cpuinfo_max_freq); |
| define_one_ro(scaling_available_governors); |
| define_one_ro(scaling_driver); |
| define_one_ro(scaling_cur_freq); |
| define_one_ro(affected_cpus); |
| define_one_rw(scaling_min_freq); |
| define_one_rw(scaling_max_freq); |
| define_one_rw(scaling_governor); |
| |
| static struct attribute * default_attrs[] = { |
| &cpuinfo_min_freq.attr, |
| &cpuinfo_max_freq.attr, |
| &scaling_min_freq.attr, |
| &scaling_max_freq.attr, |
| &affected_cpus.attr, |
| &scaling_governor.attr, |
| &scaling_driver.attr, |
| &scaling_available_governors.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; |
| policy = cpufreq_cpu_get(policy->cpu); |
| if (!policy) |
| return -EINVAL; |
| ret = fattr->show ? fattr->show(policy,buf) : -EIO; |
| cpufreq_cpu_put(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; |
| policy = cpufreq_cpu_get(policy->cpu); |
| if (!policy) |
| return -EINVAL; |
| ret = fattr->store ? fattr->store(policy,buf,count) : -EIO; |
| cpufreq_cpu_put(policy); |
| return ret; |
| } |
| |
| static void cpufreq_sysfs_release(struct kobject * kobj) |
| { |
| struct cpufreq_policy * policy = to_policy(kobj); |
| dprintk("last reference is dropped\n"); |
| complete(&policy->kobj_unregister); |
| } |
| |
| static 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, |
| }; |
| |
| |
| /** |
| * cpufreq_add_dev - add a CPU device |
| * |
| * Adds the cpufreq interface for a CPU device. |
| */ |
| static int cpufreq_add_dev (struct sys_device * sys_dev) |
| { |
| unsigned int cpu = sys_dev->id; |
| int ret = 0; |
| struct cpufreq_policy new_policy; |
| struct cpufreq_policy *policy; |
| struct freq_attr **drv_attr; |
| struct sys_device *cpu_sys_dev; |
| unsigned long flags; |
| unsigned int j; |
| #ifdef CONFIG_SMP |
| struct cpufreq_policy *managed_policy; |
| #endif |
| |
| if (cpu_is_offline(cpu)) |
| return 0; |
| |
| cpufreq_debug_disable_ratelimit(); |
| dprintk("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); |
| cpufreq_debug_enable_ratelimit(); |
| return 0; |
| } |
| #endif |
| |
| if (!try_module_get(cpufreq_driver->owner)) { |
| ret = -EINVAL; |
| goto module_out; |
| } |
| |
| policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
| if (!policy) { |
| ret = -ENOMEM; |
| goto nomem_out; |
| } |
| |
| policy->cpu = cpu; |
| policy->cpus = cpumask_of_cpu(cpu); |
| |
| mutex_init(&policy->lock); |
| mutex_lock(&policy->lock); |
| init_completion(&policy->kobj_unregister); |
| INIT_WORK(&policy->update, handle_update, (void *)(long)cpu); |
| |
| /* call driver. From then on the cpufreq must be able |
| * to accept all calls to ->verify and ->setpolicy for this CPU |
| */ |
| ret = cpufreq_driver->init(policy); |
| if (ret) { |
| dprintk("initialization failed\n"); |
| mutex_unlock(&policy->lock); |
| goto err_out; |
| } |
| |
| #ifdef CONFIG_SMP |
| for_each_cpu_mask(j, policy->cpus) { |
| if (cpu == j) |
| continue; |
| |
| /* check for existing affected CPUs. They may not be aware |
| * of it due to CPU Hotplug. |
| */ |
| managed_policy = cpufreq_cpu_get(j); |
| if (unlikely(managed_policy)) { |
| spin_lock_irqsave(&cpufreq_driver_lock, flags); |
| managed_policy->cpus = policy->cpus; |
| cpufreq_cpu_data[cpu] = managed_policy; |
| spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| dprintk("CPU already managed, adding link\n"); |
| sysfs_create_link(&sys_dev->kobj, |
| &managed_policy->kobj, "cpufreq"); |
| |
| cpufreq_debug_enable_ratelimit(); |
| mutex_unlock(&policy->lock); |
| ret = 0; |
| goto err_out_driver_exit; /* call driver->exit() */ |
| } |
| } |
| #endif |
| memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
| |
| /* prepare interface data */ |
| policy->kobj.parent = &sys_dev->kobj; |
| policy->kobj.ktype = &ktype_cpufreq; |
| strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN); |
| |
| ret = kobject_register(&policy->kobj); |
| if (ret) { |
| mutex_unlock(&policy->lock); |
| goto err_out_driver_exit; |
| } |
| /* set up files for this cpu device */ |
| drv_attr = cpufreq_driver->attr; |
| while ((drv_attr) && (*drv_attr)) { |
| sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
| drv_attr++; |
| } |
| if (cpufreq_driver->get) |
| sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
| if (cpufreq_driver->target) |
| sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
| |
| spin_lock_irqsave(&cpufreq_driver_lock, flags); |
| for_each_cpu_mask(j, policy->cpus) |
| cpufreq_cpu_data[j] = policy; |
| spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| /* symlink affected CPUs */ |
| for_each_cpu_mask(j, policy->cpus) { |
| if (j == cpu) |
| continue; |
| if (!cpu_online(j)) |
| continue; |
| |
| dprintk("CPU %u already managed, adding link\n", j); |
| cpufreq_cpu_get(cpu); |
| cpu_sys_dev = get_cpu_sysdev(j); |
| sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, |
| "cpufreq"); |
| } |
| |
| policy->governor = NULL; /* to assure that the starting sequence is |
| * run in cpufreq_set_policy */ |
| mutex_unlock(&policy->lock); |
| |
| /* set default policy */ |
| ret = cpufreq_set_policy(&new_policy); |
| if (ret) { |
| dprintk("setting policy failed\n"); |
| goto err_out_unregister; |
| } |
| |
| module_put(cpufreq_driver->owner); |
| dprintk("initialization complete\n"); |
| cpufreq_debug_enable_ratelimit(); |
| |
| return 0; |
| |
| |
| err_out_unregister: |
| spin_lock_irqsave(&cpufreq_driver_lock, flags); |
| for_each_cpu_mask(j, policy->cpus) |
| cpufreq_cpu_data[j] = NULL; |
| spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| kobject_unregister(&policy->kobj); |
| wait_for_completion(&policy->kobj_unregister); |
| |
| err_out_driver_exit: |
| if (cpufreq_driver->exit) |
| cpufreq_driver->exit(policy); |
| |
| err_out: |
| kfree(policy); |
| |
| nomem_out: |
| module_put(cpufreq_driver->owner); |
| module_out: |
| cpufreq_debug_enable_ratelimit(); |
| return ret; |
| } |
| |
| |
| /** |
| * cpufreq_remove_dev - remove a CPU device |
| * |
| * Removes the cpufreq interface for a CPU device. |
| */ |
| static int cpufreq_remove_dev (struct sys_device * sys_dev) |
| { |
| unsigned int cpu = sys_dev->id; |
| unsigned long flags; |
| struct cpufreq_policy *data; |
| #ifdef CONFIG_SMP |
| struct sys_device *cpu_sys_dev; |
| unsigned int j; |
| #endif |
| |
| cpufreq_debug_disable_ratelimit(); |
| dprintk("unregistering CPU %u\n", cpu); |
| |
| spin_lock_irqsave(&cpufreq_driver_lock, flags); |
| data = cpufreq_cpu_data[cpu]; |
| |
| if (!data) { |
| spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| cpufreq_debug_enable_ratelimit(); |
| return -EINVAL; |
| } |
| 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)) { |
| dprintk("removing link\n"); |
| cpu_clear(cpu, data->cpus); |
| spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| sysfs_remove_link(&sys_dev->kobj, "cpufreq"); |
| cpufreq_cpu_put(data); |
| cpufreq_debug_enable_ratelimit(); |
| return 0; |
| } |
| #endif |
| |
| |
| if (!kobject_get(&data->kobj)) { |
| spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| cpufreq_debug_enable_ratelimit(); |
| return -EFAULT; |
| } |
| |
| #ifdef CONFIG_SMP |
| /* if we have other CPUs still registered, we need to unlink them, |
| * or else wait_for_completion below will lock up. Clean the |
| * cpufreq_cpu_data[] while holding the lock, and remove the sysfs |
| * links afterwards. |
| */ |
| if (unlikely(cpus_weight(data->cpus) > 1)) { |
| for_each_cpu_mask(j, data->cpus) { |
| if (j == cpu) |
| continue; |
| cpufreq_cpu_data[j] = NULL; |
| } |
| } |
| |
| spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| |
| if (unlikely(cpus_weight(data->cpus) > 1)) { |
| for_each_cpu_mask(j, data->cpus) { |
| if (j == cpu) |
| continue; |
| dprintk("removing link for cpu %u\n", j); |
| cpu_sys_dev = get_cpu_sysdev(j); |
| sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); |
| cpufreq_cpu_put(data); |
| } |
| } |
| #else |
| spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| #endif |
| |
| mutex_lock(&data->lock); |
| if (cpufreq_driver->target) |
| __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
| mutex_unlock(&data->lock); |
| |
| kobject_unregister(&data->kobj); |
| |
| kobject_put(&data->kobj); |
| |
| /* we need to make sure that the underlying kobj is actually |
| * not referenced anymore by anybody before we proceed with |
| * unloading. |
| */ |
| dprintk("waiting for dropping of refcount\n"); |
| wait_for_completion(&data->kobj_unregister); |
| dprintk("wait complete\n"); |
| |
| if (cpufreq_driver->exit) |
| cpufreq_driver->exit(data); |
| |
| kfree(data); |
| |
| cpufreq_debug_enable_ratelimit(); |
| return 0; |
| } |
| |
| |
| static void handle_update(void *data) |
| { |
| unsigned int cpu = (unsigned int)(long)data; |
| dprintk("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; |
| |
| dprintk("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) frpm 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 = 0; |
| |
| if (policy) { |
| mutex_lock(&policy->lock); |
| ret = policy->cur; |
| mutex_unlock(&policy->lock); |
| cpufreq_cpu_put(policy); |
| } |
| |
| return (ret); |
| } |
| EXPORT_SYMBOL(cpufreq_quick_get); |
| |
| |
| /** |
| * cpufreq_get - get the current CPU frequency (in kHz) |
| * @cpu: CPU number |
| * |
| * Get the CPU current (static) CPU frequency |
| */ |
| unsigned int cpufreq_get(unsigned int cpu) |
| { |
| struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
| unsigned int ret = 0; |
| |
| if (!policy) |
| return 0; |
| |
| if (!cpufreq_driver->get) |
| goto out; |
| |
| mutex_lock(&policy->lock); |
| |
| ret = cpufreq_driver->get(cpu); |
| |
| if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
| /* verify no discrepancy between actual and saved value exists */ |
| if (unlikely(ret != policy->cur)) { |
| cpufreq_out_of_sync(cpu, policy->cur, ret); |
| schedule_work(&policy->update); |
| } |
| } |
| |
| mutex_unlock(&policy->lock); |
| |
| out: |
| cpufreq_cpu_put(policy); |
| |
| return (ret); |
| } |
| EXPORT_SYMBOL(cpufreq_get); |
| |
| |
| /** |
| * cpufreq_suspend - let the low level driver prepare for suspend |
| */ |
| |
| static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) |
| { |
| int cpu = sysdev->id; |
| unsigned int ret = 0; |
| unsigned int cur_freq = 0; |
| struct cpufreq_policy *cpu_policy; |
| |
| dprintk("suspending cpu %u\n", cpu); |
| |
| if (!cpu_online(cpu)) |
| return 0; |
| |
| /* we may be lax here as interrupts are off. Nonetheless |
| * we need to grab the correct cpu policy, as to check |
| * whether we really run on this CPU. |
| */ |
| |
| cpu_policy = cpufreq_cpu_get(cpu); |
| if (!cpu_policy) |
| return -EINVAL; |
| |
| /* only handle each CPU group once */ |
| if (unlikely(cpu_policy->cpu != cpu)) { |
| cpufreq_cpu_put(cpu_policy); |
| return 0; |
| } |
| |
| if (cpufreq_driver->suspend) { |
| ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
| 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; |
| } |
| } |
| |
| |
| if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) |
| goto out; |
| |
| if (cpufreq_driver->get) |
| cur_freq = cpufreq_driver->get(cpu_policy->cpu); |
| |
| if (!cur_freq || !cpu_policy->cur) { |
| printk(KERN_ERR "cpufreq: suspend failed to assert current " |
| "frequency is what timing core thinks it is.\n"); |
| goto out; |
| } |
| |
| if (unlikely(cur_freq != cpu_policy->cur)) { |
| struct cpufreq_freqs freqs; |
| |
| if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
| dprintk("Warning: CPU frequency is %u, " |
| "cpufreq assumed %u kHz.\n", |
| cur_freq, cpu_policy->cur); |
| |
| freqs.cpu = cpu; |
| freqs.old = cpu_policy->cur; |
| freqs.new = cur_freq; |
| |
| srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
| CPUFREQ_SUSPENDCHANGE, &freqs); |
| adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); |
| |
| cpu_policy->cur = cur_freq; |
| } |
| |
| out: |
| cpufreq_cpu_put(cpu_policy); |
| return 0; |
| } |
| |
| /** |
| * cpufreq_resume - restore proper CPU frequency handling after resume |
| * |
| * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) |
| * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync |
| * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
| * restored. |
| */ |
| static int cpufreq_resume(struct sys_device * sysdev) |
| { |
| int cpu = sysdev->id; |
| unsigned int ret = 0; |
| struct cpufreq_policy *cpu_policy; |
| |
| dprintk("resuming cpu %u\n", cpu); |
| |
| if (!cpu_online(cpu)) |
| return 0; |
| |
| /* we may be lax here as interrupts are off. Nonetheless |
| * we need to grab the correct cpu policy, as to check |
| * whether we really run on this CPU. |
| */ |
| |
| cpu_policy = cpufreq_cpu_get(cpu); |
| if (!cpu_policy) |
| return -EINVAL; |
| |
| /* only handle each CPU group once */ |
| if (unlikely(cpu_policy->cpu != cpu)) { |
| cpufreq_cpu_put(cpu_policy); |
| return 0; |
| } |
| |
| 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); |
| cpufreq_cpu_put(cpu_policy); |
| return ret; |
| } |
| } |
| |
| if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
| unsigned int cur_freq = 0; |
| |
| if (cpufreq_driver->get) |
| cur_freq = cpufreq_driver->get(cpu_policy->cpu); |
| |
| if (!cur_freq || !cpu_policy->cur) { |
| printk(KERN_ERR "cpufreq: resume failed to assert " |
| "current frequency is what timing core " |
| "thinks it is.\n"); |
| goto out; |
| } |
| |
| if (unlikely(cur_freq != cpu_policy->cur)) { |
| struct cpufreq_freqs freqs; |
| |
| if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
| dprintk("Warning: CPU frequency" |
| "is %u, cpufreq assumed %u kHz.\n", |
| cur_freq, cpu_policy->cur); |
| |
| freqs.cpu = cpu; |
| freqs.old = cpu_policy->cur; |
| freqs.new = cur_freq; |
| |
| srcu_notifier_call_chain( |
| &cpufreq_transition_notifier_list, |
| CPUFREQ_RESUMECHANGE, &freqs); |
| adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
| |
| cpu_policy->cur = cur_freq; |
| } |
| } |
| |
| out: |
| schedule_work(&cpu_policy->update); |
| cpufreq_cpu_put(cpu_policy); |
| return ret; |
| } |
| |
| static struct sysdev_driver cpufreq_sysdev_driver = { |
| .add = cpufreq_add_dev, |
| .remove = cpufreq_remove_dev, |
| .suspend = cpufreq_suspend, |
| .resume = cpufreq_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; |
| |
| 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 * |
| *********************************************************************/ |
| |
| |
| /* Must be called with lock_cpu_hotplug held */ |
| int __cpufreq_driver_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| int retval = -EINVAL; |
| |
| dprintk("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; |
| |
| policy = cpufreq_cpu_get(policy->cpu); |
| if (!policy) |
| return -EINVAL; |
| |
| lock_cpu_hotplug(); |
| mutex_lock(&policy->lock); |
| |
| ret = __cpufreq_driver_target(policy, target_freq, relation); |
| |
| mutex_unlock(&policy->lock); |
| unlock_cpu_hotplug(); |
| |
| cpufreq_cpu_put(policy); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_driver_target); |
| |
| int cpufreq_driver_getavg(struct cpufreq_policy *policy) |
| { |
| int ret = 0; |
| |
| policy = cpufreq_cpu_get(policy->cpu); |
| if (!policy) |
| return -EINVAL; |
| |
| mutex_lock(&policy->lock); |
| |
| if (cpu_online(policy->cpu) && cpufreq_driver->getavg) |
| ret = cpufreq_driver->getavg(policy->cpu); |
| |
| mutex_unlock(&policy->lock); |
| |
| cpufreq_cpu_put(policy); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_driver_getavg); |
| |
| /* |
| * Locking: Must be called with the lock_cpu_hotplug() lock held |
| * when "event" is CPUFREQ_GOV_LIMITS |
| */ |
| |
| static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event) |
| { |
| int ret; |
| |
| if (!try_module_get(policy->governor->owner)) |
| return -EINVAL; |
| |
| dprintk("__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; |
| |
| 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) |
| { |
| if (!governor) |
| return; |
| |
| 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; |
| |
| mutex_lock(&cpu_policy->lock); |
| memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
| mutex_unlock(&cpu_policy->lock); |
| |
| cpufreq_cpu_put(cpu_policy); |
| return 0; |
| } |
| EXPORT_SYMBOL(cpufreq_get_policy); |
| |
| |
| /* |
| * Locking: Must be called with the lock_cpu_hotplug() lock held |
| */ |
| static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy) |
| { |
| int ret = 0; |
| |
| cpufreq_debug_disable_ratelimit(); |
| dprintk("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->min && policy->min > policy->max) { |
| 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; |
| |
| dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max); |
| |
| if (cpufreq_driver->setpolicy) { |
| data->policy = policy->policy; |
| dprintk("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; |
| |
| dprintk("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 */ |
| dprintk("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 */ |
| } |
| dprintk("governor: change or update limits\n"); |
| __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
| } |
| |
| error_out: |
| cpufreq_debug_enable_ratelimit(); |
| return ret; |
| } |
| |
| /** |
| * cpufreq_set_policy - set a new CPUFreq policy |
| * @policy: policy to be set. |
| * |
| * Sets a new CPU frequency and voltage scaling policy. |
| */ |
| int cpufreq_set_policy(struct cpufreq_policy *policy) |
| { |
| int ret = 0; |
| struct cpufreq_policy *data; |
| |
| if (!policy) |
| return -EINVAL; |
| |
| data = cpufreq_cpu_get(policy->cpu); |
| if (!data) |
| return -EINVAL; |
| |
| lock_cpu_hotplug(); |
| |
| /* lock this CPU */ |
| mutex_lock(&data->lock); |
| |
| ret = __cpufreq_set_policy(data, policy); |
| data->user_policy.min = data->min; |
| data->user_policy.max = data->max; |
| data->user_policy.policy = data->policy; |
| data->user_policy.governor = data->governor; |
| |
| mutex_unlock(&data->lock); |
| |
| unlock_cpu_hotplug(); |
| cpufreq_cpu_put(data); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(cpufreq_set_policy); |
| |
| |
| /** |
| * cpufreq_update_policy - re-evaluate an existing cpufreq policy |
| * @cpu: CPU which shall be re-evaluated |
| * |
| * Usefull 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 = 0; |
| |
| if (!data) |
| return -ENODEV; |
| |
| lock_cpu_hotplug(); |
| mutex_lock(&data->lock); |
| |
| dprintk("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) { |
| dprintk("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); |
| |
| mutex_unlock(&data->lock); |
| unlock_cpu_hotplug(); |
| cpufreq_cpu_put(data); |
| return ret; |
| } |
| EXPORT_SYMBOL(cpufreq_update_policy); |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| static int cpufreq_cpu_callback(struct notifier_block *nfb, |
| unsigned long action, void *hcpu) |
| { |
| unsigned int cpu = (unsigned long)hcpu; |
| struct cpufreq_policy *policy; |
| struct sys_device *sys_dev; |
| |
| sys_dev = get_cpu_sysdev(cpu); |
| |
| if (sys_dev) { |
| switch (action) { |
| case CPU_ONLINE: |
| cpufreq_add_dev(sys_dev); |
| break; |
| case CPU_DOWN_PREPARE: |
| /* |
| * We attempt to put this cpu in lowest frequency |
| * possible before going down. This will permit |
| * hardware-managed P-State to switch other related |
| * threads to min or higher speeds if possible. |
| */ |
| policy = cpufreq_cpu_data[cpu]; |
| if (policy) { |
| cpufreq_driver_target(policy, policy->min, |
| CPUFREQ_RELATION_H); |
| } |
| break; |
| case CPU_DEAD: |
| cpufreq_remove_dev(sys_dev); |
| break; |
| } |
| } |
| return NOTIFY_OK; |
| } |
| |
| static struct notifier_block __cpuinitdata cpufreq_cpu_notifier = |
| { |
| .notifier_call = cpufreq_cpu_callback, |
| }; |
| #endif /* CONFIG_HOTPLUG_CPU */ |
| |
| /********************************************************************* |
| * 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 (!driver_data || !driver_data->verify || !driver_data->init || |
| ((!driver_data->setpolicy) && (!driver_data->target))) |
| return -EINVAL; |
| |
| dprintk("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 = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); |
| |
| if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
| int i; |
| ret = -ENODEV; |
| |
| /* check for at least one working CPU */ |
| for (i=0; i<NR_CPUS; i++) |
| if (cpufreq_cpu_data[i]) |
| ret = 0; |
| |
| /* if all ->init() calls failed, unregister */ |
| if (ret) { |
| dprintk("no CPU initialized for driver %s\n", driver_data->name); |
| sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); |
| |
| spin_lock_irqsave(&cpufreq_driver_lock, flags); |
| cpufreq_driver = NULL; |
| spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
| } |
| } |
| |
| if (!ret) { |
| register_hotcpu_notifier(&cpufreq_cpu_notifier); |
| dprintk("driver %s up and running\n", driver_data->name); |
| cpufreq_debug_enable_ratelimit(); |
| } |
| |
| 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; |
| |
| cpufreq_debug_disable_ratelimit(); |
| |
| if (!cpufreq_driver || (driver != cpufreq_driver)) { |
| cpufreq_debug_enable_ratelimit(); |
| return -EINVAL; |
| } |
| |
| dprintk("unregistering driver %s\n", driver->name); |
| |
| sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); |
| 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); |