diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 223 |
1 files changed, 163 insertions, 60 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 2d53f47d1747..6a015ada5285 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -3,6 +3,7 @@ * * Copyright (C) 2001 Russell King * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> + * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> * * Oct 2005 - Ashok Raj <ashok.raj@intel.com> * Added handling for CPU hotplug @@ -12,12 +13,13 @@ * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. - * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <asm/cputime.h> #include <linux/kernel.h> +#include <linux/kernel_stat.h> #include <linux/module.h> #include <linux/init.h> #include <linux/notifier.h> @@ -25,6 +27,7 @@ #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/spinlock.h> +#include <linux/tick.h> #include <linux/device.h> #include <linux/slab.h> #include <linux/cpu.h> @@ -41,11 +44,13 @@ */ static struct cpufreq_driver *cpufreq_driver; static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); +static DEFINE_RWLOCK(cpufreq_driver_lock); +static DEFINE_MUTEX(cpufreq_governor_lock); + #ifdef CONFIG_HOTPLUG_CPU /* This one keeps track of the previously set governor of a removed CPU */ static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); #endif -static DEFINE_RWLOCK(cpufreq_driver_lock); /* * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure @@ -132,6 +137,51 @@ bool have_governor_per_policy(void) { return cpufreq_driver->have_governor_per_policy; } +EXPORT_SYMBOL_GPL(have_governor_per_policy); + +struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) +{ + if (have_governor_per_policy()) + return &policy->kobj; + else + return cpufreq_global_kobject; +} +EXPORT_SYMBOL_GPL(get_governor_parent_kobj); + +static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) +{ + u64 idle_time; + u64 cur_wall_time; + u64 busy_time; + + cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); + + busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; + + idle_time = cur_wall_time - busy_time; + if (wall) + *wall = cputime_to_usecs(cur_wall_time); + + return cputime_to_usecs(idle_time); +} + +u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) +{ + u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); + + if (idle_time == -1ULL) + return get_cpu_idle_time_jiffy(cpu, wall); + else if (!io_busy) + idle_time += get_cpu_iowait_time_us(cpu, wall); + + return idle_time; +} +EXPORT_SYMBOL_GPL(get_cpu_idle_time); static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) { @@ -150,7 +200,6 @@ static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) if (!try_module_get(cpufreq_driver->owner)) goto err_out_unlock; - /* get the CPU */ data = per_cpu(cpufreq_cpu_data, cpu); @@ -220,7 +269,7 @@ static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) */ #ifndef CONFIG_SMP static unsigned long l_p_j_ref; -static unsigned int l_p_j_ref_freq; +static unsigned int l_p_j_ref_freq; static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) { @@ -233,7 +282,7 @@ static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) 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) || + 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); @@ -248,8 +297,7 @@ static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) } #endif - -void __cpufreq_notify_transition(struct cpufreq_policy *policy, +static void __cpufreq_notify_transition(struct cpufreq_policy *policy, struct cpufreq_freqs *freqs, unsigned int state) { BUG_ON(irqs_disabled()); @@ -264,6 +312,12 @@ void __cpufreq_notify_transition(struct cpufreq_policy *policy, switch (state) { case CPUFREQ_PRECHANGE: + if (WARN(policy->transition_ongoing, + "In middle of another frequency transition\n")) + return; + + policy->transition_ongoing = true; + /* detect if the driver reported a value as "old frequency" * which is not equal to what the cpufreq core thinks is * "old frequency". @@ -283,6 +337,12 @@ void __cpufreq_notify_transition(struct cpufreq_policy *policy, break; case CPUFREQ_POSTCHANGE: + if (WARN(!policy->transition_ongoing, + "No frequency transition in progress\n")) + return; + + policy->transition_ongoing = false; + adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, (unsigned long)freqs->cpu); @@ -294,6 +354,7 @@ void __cpufreq_notify_transition(struct cpufreq_policy *policy, break; } } + /** * cpufreq_notify_transition - call notifier chain and adjust_jiffies * on frequency transition. @@ -311,7 +372,6 @@ void cpufreq_notify_transition(struct cpufreq_policy *policy, EXPORT_SYMBOL_GPL(cpufreq_notify_transition); - /********************************************************************* * SYSFS INTERFACE * *********************************************************************/ @@ -376,7 +436,6 @@ out: return err; } - /** * cpufreq_per_cpu_attr_read() / show_##file_name() - * print out cpufreq information @@ -441,7 +500,6 @@ static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, return sprintf(buf, "%u\n", cur_freq); } - /** * show_scaling_governor - show the current policy for the specified CPU */ @@ -457,7 +515,6 @@ static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) return -EINVAL; } - /** * store_scaling_governor - store policy for the specified CPU */ @@ -480,8 +537,10 @@ static ssize_t store_scaling_governor(struct cpufreq_policy *policy, &new_policy.governor)) return -EINVAL; - /* Do not use cpufreq_set_policy here or the user_policy.max - will be wrongly overridden */ + /* + * 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; @@ -526,7 +585,7 @@ out: return i; } -static ssize_t show_cpus(const struct cpumask *mask, char *buf) +ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) { ssize_t i = 0; unsigned int cpu; @@ -541,6 +600,7 @@ static ssize_t show_cpus(const struct cpumask *mask, char *buf) i += sprintf(&buf[i], "\n"); return i; } +EXPORT_SYMBOL_GPL(cpufreq_show_cpus); /** * show_related_cpus - show the CPUs affected by each transition even if @@ -548,7 +608,7 @@ static ssize_t show_cpus(const struct cpumask *mask, char *buf) */ static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) { - return show_cpus(policy->related_cpus, buf); + return cpufreq_show_cpus(policy->related_cpus, buf); } /** @@ -556,7 +616,7 @@ static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) */ static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) { - return show_cpus(policy->cpus, buf); + return cpufreq_show_cpus(policy->cpus, buf); } static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, @@ -630,9 +690,6 @@ static struct attribute *default_attrs[] = { 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) @@ -703,6 +760,49 @@ static struct kobj_type ktype_cpufreq = { .release = cpufreq_sysfs_release, }; +struct kobject *cpufreq_global_kobject; +EXPORT_SYMBOL(cpufreq_global_kobject); + +static int cpufreq_global_kobject_usage; + +int cpufreq_get_global_kobject(void) +{ + if (!cpufreq_global_kobject_usage++) + return kobject_add(cpufreq_global_kobject, + &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); + + return 0; +} +EXPORT_SYMBOL(cpufreq_get_global_kobject); + +void cpufreq_put_global_kobject(void) +{ + if (!--cpufreq_global_kobject_usage) + kobject_del(cpufreq_global_kobject); +} +EXPORT_SYMBOL(cpufreq_put_global_kobject); + +int cpufreq_sysfs_create_file(const struct attribute *attr) +{ + int ret = cpufreq_get_global_kobject(); + + if (!ret) { + ret = sysfs_create_file(cpufreq_global_kobject, attr); + if (ret) + cpufreq_put_global_kobject(); + } + + return ret; +} +EXPORT_SYMBOL(cpufreq_sysfs_create_file); + +void cpufreq_sysfs_remove_file(const struct attribute *attr) +{ + sysfs_remove_file(cpufreq_global_kobject, attr); + cpufreq_put_global_kobject(); +} +EXPORT_SYMBOL(cpufreq_sysfs_remove_file); + /* symlink affected CPUs */ static int cpufreq_add_dev_symlink(unsigned int cpu, struct cpufreq_policy *policy) @@ -1005,7 +1105,8 @@ static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) * 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) +static int __cpufreq_remove_dev(struct device *dev, + struct subsys_interface *sif) { unsigned int cpu = dev->id, ret, cpus; unsigned long flags; @@ -1112,7 +1213,6 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif return 0; } - static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) { unsigned int cpu = dev->id; @@ -1125,7 +1225,6 @@ static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) return retval; } - static void handle_update(struct work_struct *work) { struct cpufreq_policy *policy = @@ -1136,7 +1235,8 @@ static void handle_update(struct work_struct *work) } /** - * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. + * 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 @@ -1151,7 +1251,6 @@ static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, struct cpufreq_freqs freqs; unsigned long flags; - pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " "core thinks of %u, is %u kHz.\n", old_freq, new_freq); @@ -1166,7 +1265,6 @@ static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); } - /** * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur * @cpu: CPU number @@ -1212,7 +1310,6 @@ unsigned int cpufreq_quick_get_max(unsigned int cpu) } EXPORT_SYMBOL(cpufreq_quick_get_max); - static unsigned int __cpufreq_get(unsigned int cpu) { struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); @@ -1271,7 +1368,6 @@ static struct subsys_interface cpufreq_interface = { .remove_dev = cpufreq_remove_dev, }; - /** * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. * @@ -1408,11 +1504,10 @@ int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) } 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 + * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER * * Remove a driver from the CPU frequency notifier list. * @@ -1448,7 +1543,6 @@ EXPORT_SYMBOL(cpufreq_unregister_notifier); * GOVERNORS * *********************************************************************/ - int __cpufreq_driver_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) @@ -1458,6 +1552,8 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy, if (cpufreq_disabled()) return -ENODEV; + if (policy->transition_ongoing) + return -EBUSY; /* Make sure that target_freq is within supported range */ if (target_freq > policy->max) @@ -1484,10 +1580,6 @@ int cpufreq_driver_target(struct cpufreq_policy *policy, { int ret = -EINVAL; - policy = cpufreq_cpu_get(policy->cpu); - if (!policy) - goto no_policy; - if (unlikely(lock_policy_rwsem_write(policy->cpu))) goto fail; @@ -1496,30 +1588,19 @@ int cpufreq_driver_target(struct cpufreq_policy *policy, unlock_policy_rwsem_write(policy->cpu); fail: - cpufreq_cpu_put(policy); -no_policy: return ret; } EXPORT_SYMBOL_GPL(cpufreq_driver_target); int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) { - int ret = 0; - if (cpufreq_disabled()) - return ret; + return 0; if (!cpufreq_driver->getavg) return 0; - policy = cpufreq_cpu_get(policy->cpu); - if (!policy) - return -EINVAL; - - ret = cpufreq_driver->getavg(policy, cpu); - - cpufreq_cpu_put(policy); - return ret; + return cpufreq_driver->getavg(policy, cpu); } EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); @@ -1562,6 +1643,21 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, pr_debug("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event); + + mutex_lock(&cpufreq_governor_lock); + if ((!policy->governor_enabled && (event == CPUFREQ_GOV_STOP)) || + (policy->governor_enabled && (event == CPUFREQ_GOV_START))) { + mutex_unlock(&cpufreq_governor_lock); + return -EBUSY; + } + + if (event == CPUFREQ_GOV_STOP) + policy->governor_enabled = false; + else if (event == CPUFREQ_GOV_START) + policy->governor_enabled = true; + + mutex_unlock(&cpufreq_governor_lock); + ret = policy->governor->governor(policy, event); if (!ret) { @@ -1569,6 +1665,14 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, policy->governor->initialized++; else if (event == CPUFREQ_GOV_POLICY_EXIT) policy->governor->initialized--; + } else { + /* Restore original values */ + mutex_lock(&cpufreq_governor_lock); + if (event == CPUFREQ_GOV_STOP) + policy->governor_enabled = true; + else if (event == CPUFREQ_GOV_START) + policy->governor_enabled = false; + mutex_unlock(&cpufreq_governor_lock); } /* we keep one module reference alive for @@ -1581,7 +1685,6 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, return ret; } - int cpufreq_register_governor(struct cpufreq_governor *governor) { int err; @@ -1606,7 +1709,6 @@ int cpufreq_register_governor(struct cpufreq_governor *governor) } EXPORT_SYMBOL_GPL(cpufreq_register_governor); - void cpufreq_unregister_governor(struct cpufreq_governor *governor) { #ifdef CONFIG_HOTPLUG_CPU @@ -1636,7 +1738,6 @@ void cpufreq_unregister_governor(struct cpufreq_governor *governor) EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); - /********************************************************************* * POLICY INTERFACE * *********************************************************************/ @@ -1665,7 +1766,6 @@ int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) } EXPORT_SYMBOL(cpufreq_get_policy); - /* * data : current policy. * policy : policy to be set. @@ -1699,8 +1799,10 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data, 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 */ + /* + * 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; @@ -1802,8 +1904,10 @@ int cpufreq_update_policy(unsigned int cpu) 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 */ + /* + * 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) { @@ -1852,7 +1956,7 @@ static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, } static struct notifier_block __refdata cpufreq_cpu_notifier = { - .notifier_call = cpufreq_cpu_callback, + .notifier_call = cpufreq_cpu_callback, }; /********************************************************************* @@ -1864,7 +1968,7 @@ static struct notifier_block __refdata cpufreq_cpu_notifier = { * @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 + * 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). * @@ -1931,11 +2035,10 @@ err_null_driver: } 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 + * 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. @@ -1972,7 +2075,7 @@ static int __init cpufreq_core_init(void) init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); } - cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); + cpufreq_global_kobject = kobject_create(); BUG_ON(!cpufreq_global_kobject); register_syscore_ops(&cpufreq_syscore_ops); |