diff options
author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/cpufreq/cpufreq.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/cpufreq/cpufreq.c')
-rw-r--r-- | kernel/drivers/cpufreq/cpufreq.c | 2511 |
1 files changed, 2511 insertions, 0 deletions
diff --git a/kernel/drivers/cpufreq/cpufreq.c b/kernel/drivers/cpufreq/cpufreq.c new file mode 100644 index 000000000..ce1d93e93 --- /dev/null +++ b/kernel/drivers/cpufreq/cpufreq.c @@ -0,0 +1,2511 @@ +/* + * linux/drivers/cpufreq/cpufreq.c + * + * Copyright (C) 2001 Russell King + * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> + * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> + * + * Oct 2005 - Ashok Raj <ashok.raj@intel.com> + * Added handling for CPU hotplug + * Feb 2006 - Jacob Shin <jacob.shin@amd.com> + * Fix handling for CPU hotplug -- affected CPUs + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cpu.h> +#include <linux/cpufreq.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/kernel_stat.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/suspend.h> +#include <linux/syscore_ops.h> +#include <linux/tick.h> +#include <trace/events/power.h> + +/* Macros to iterate over lists */ +/* Iterate over online CPUs policies */ +static LIST_HEAD(cpufreq_policy_list); +#define for_each_policy(__policy) \ + list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) + +/* Iterate over governors */ +static LIST_HEAD(cpufreq_governor_list); +#define for_each_governor(__governor) \ + list_for_each_entry(__governor, &cpufreq_governor_list, governor_list) + +/** + * The "cpufreq driver" - the arch- or hardware-dependent low + * level driver of CPUFreq support, and its spinlock. This lock + * also protects the cpufreq_cpu_data array. + */ +static struct cpufreq_driver *cpufreq_driver; +static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); +static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback); +static DEFINE_RWLOCK(cpufreq_driver_lock); +DEFINE_MUTEX(cpufreq_governor_lock); + +/* This one keeps track of the previously set governor of a removed CPU */ +static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); + +/* Flag to suspend/resume CPUFreq governors */ +static bool cpufreq_suspended; + +static inline bool has_target(void) +{ + return cpufreq_driver->target_index || cpufreq_driver->target; +} + +/* internal prototypes */ +static int __cpufreq_governor(struct cpufreq_policy *policy, + unsigned int event); +static unsigned int __cpufreq_get(struct cpufreq_policy *policy); +static void handle_update(struct work_struct *work); + +/** + * Two notifier lists: the "policy" list is involved in the + * validation process for a new CPU frequency policy; the + * "transition" list for kernel code that needs to handle + * changes to devices when the CPU clock speed changes. + * The mutex locks both lists. + */ +static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); +static struct srcu_notifier_head cpufreq_transition_notifier_list; + +static bool init_cpufreq_transition_notifier_list_called; +static int __init init_cpufreq_transition_notifier_list(void) +{ + srcu_init_notifier_head(&cpufreq_transition_notifier_list); + init_cpufreq_transition_notifier_list_called = true; + return 0; +} +pure_initcall(init_cpufreq_transition_notifier_list); + +static int off __read_mostly; +static int cpufreq_disabled(void) +{ + return off; +} +void disable_cpufreq(void) +{ + off = 1; +} +static DEFINE_MUTEX(cpufreq_governor_mutex); + +bool have_governor_per_policy(void) +{ + return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); +} +EXPORT_SYMBOL_GPL(have_governor_per_policy); + +struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) +{ + if (have_governor_per_policy()) + return &policy->kobj; + else + return cpufreq_global_kobject; +} +EXPORT_SYMBOL_GPL(get_governor_parent_kobj); + +static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) +{ + u64 idle_time; + u64 cur_wall_time; + u64 busy_time; + + cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); + + busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; + busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; + + idle_time = cur_wall_time - busy_time; + if (wall) + *wall = cputime_to_usecs(cur_wall_time); + + return cputime_to_usecs(idle_time); +} + +u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) +{ + u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); + + if (idle_time == -1ULL) + return get_cpu_idle_time_jiffy(cpu, wall); + else if (!io_busy) + idle_time += get_cpu_iowait_time_us(cpu, wall); + + return idle_time; +} +EXPORT_SYMBOL_GPL(get_cpu_idle_time); + +/* + * This is a generic cpufreq init() routine which can be used by cpufreq + * drivers of SMP systems. It will do following: + * - validate & show freq table passed + * - set policies transition latency + * - policy->cpus with all possible CPUs + */ +int cpufreq_generic_init(struct cpufreq_policy *policy, + struct cpufreq_frequency_table *table, + unsigned int transition_latency) +{ + int ret; + + ret = cpufreq_table_validate_and_show(policy, table); + if (ret) { + pr_err("%s: invalid frequency table: %d\n", __func__, ret); + return ret; + } + + policy->cpuinfo.transition_latency = transition_latency; + + /* + * The driver only supports the SMP configuartion where all processors + * share the clock and voltage and clock. + */ + cpumask_setall(policy->cpus); + + return 0; +} +EXPORT_SYMBOL_GPL(cpufreq_generic_init); + +unsigned int cpufreq_generic_get(unsigned int cpu) +{ + struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); + + if (!policy || IS_ERR(policy->clk)) { + pr_err("%s: No %s associated to cpu: %d\n", + __func__, policy ? "clk" : "policy", cpu); + return 0; + } + + return clk_get_rate(policy->clk) / 1000; +} +EXPORT_SYMBOL_GPL(cpufreq_generic_get); + +/* Only for cpufreq core internal use */ +struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) +{ + return per_cpu(cpufreq_cpu_data, cpu); +} + +struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) +{ + struct cpufreq_policy *policy = NULL; + unsigned long flags; + + if (cpu >= nr_cpu_ids) + return NULL; + + /* get the cpufreq driver */ + read_lock_irqsave(&cpufreq_driver_lock, flags); + + if (cpufreq_driver) { + /* get the CPU */ + policy = per_cpu(cpufreq_cpu_data, cpu); + if (policy) + kobject_get(&policy->kobj); + } + + read_unlock_irqrestore(&cpufreq_driver_lock, flags); + + return policy; +} +EXPORT_SYMBOL_GPL(cpufreq_cpu_get); + +void cpufreq_cpu_put(struct cpufreq_policy *policy) +{ + kobject_put(&policy->kobj); +} +EXPORT_SYMBOL_GPL(cpufreq_cpu_put); + +/********************************************************************* + * EXTERNALLY AFFECTING FREQUENCY CHANGES * + *********************************************************************/ + +/** + * adjust_jiffies - adjust the system "loops_per_jiffy" + * + * This function alters the system "loops_per_jiffy" for the clock + * speed change. Note that loops_per_jiffy cannot be updated on SMP + * systems as each CPU might be scaled differently. So, use the arch + * per-CPU loops_per_jiffy value wherever possible. + */ +static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) +{ +#ifndef CONFIG_SMP + static unsigned long l_p_j_ref; + static unsigned int l_p_j_ref_freq; + + if (ci->flags & CPUFREQ_CONST_LOOPS) + return; + + if (!l_p_j_ref_freq) { + l_p_j_ref = loops_per_jiffy; + l_p_j_ref_freq = ci->old; + pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", + l_p_j_ref, l_p_j_ref_freq); + } + if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) { + loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, + ci->new); + pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n", + loops_per_jiffy, ci->new); + } +#endif +} + +static void __cpufreq_notify_transition(struct cpufreq_policy *policy, + struct cpufreq_freqs *freqs, unsigned int state) +{ + BUG_ON(irqs_disabled()); + + if (cpufreq_disabled()) + return; + + freqs->flags = cpufreq_driver->flags; + pr_debug("notification %u of frequency transition to %u kHz\n", + state, freqs->new); + + switch (state) { + + case CPUFREQ_PRECHANGE: + /* detect if the driver reported a value as "old frequency" + * which is not equal to what the cpufreq core thinks is + * "old frequency". + */ + if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { + if ((policy) && (policy->cpu == freqs->cpu) && + (policy->cur) && (policy->cur != freqs->old)) { + pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", + freqs->old, policy->cur); + freqs->old = policy->cur; + } + } + srcu_notifier_call_chain(&cpufreq_transition_notifier_list, + CPUFREQ_PRECHANGE, freqs); + adjust_jiffies(CPUFREQ_PRECHANGE, freqs); + break; + + case CPUFREQ_POSTCHANGE: + adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); + pr_debug("FREQ: %lu - CPU: %lu\n", + (unsigned long)freqs->new, (unsigned long)freqs->cpu); + trace_cpu_frequency(freqs->new, freqs->cpu); + srcu_notifier_call_chain(&cpufreq_transition_notifier_list, + CPUFREQ_POSTCHANGE, freqs); + if (likely(policy) && likely(policy->cpu == freqs->cpu)) + policy->cur = freqs->new; + break; + } +} + +/** + * cpufreq_notify_transition - call notifier chain and adjust_jiffies + * on frequency transition. + * + * This function calls the transition notifiers and the "adjust_jiffies" + * function. It is called twice on all CPU frequency changes that have + * external effects. + */ +static void cpufreq_notify_transition(struct cpufreq_policy *policy, + struct cpufreq_freqs *freqs, unsigned int state) +{ + for_each_cpu(freqs->cpu, policy->cpus) + __cpufreq_notify_transition(policy, freqs, state); +} + +/* Do post notifications when there are chances that transition has failed */ +static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, + struct cpufreq_freqs *freqs, int transition_failed) +{ + cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); + if (!transition_failed) + return; + + swap(freqs->old, freqs->new); + cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); + cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); +} + +void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, + struct cpufreq_freqs *freqs) +{ + + /* + * Catch double invocations of _begin() which lead to self-deadlock. + * ASYNC_NOTIFICATION drivers are left out because the cpufreq core + * doesn't invoke _begin() on their behalf, and hence the chances of + * double invocations are very low. Moreover, there are scenarios + * where these checks can emit false-positive warnings in these + * drivers; so we avoid that by skipping them altogether. + */ + WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) + && current == policy->transition_task); + +wait: + wait_event(policy->transition_wait, !policy->transition_ongoing); + + spin_lock(&policy->transition_lock); + + if (unlikely(policy->transition_ongoing)) { + spin_unlock(&policy->transition_lock); + goto wait; + } + + policy->transition_ongoing = true; + policy->transition_task = current; + + spin_unlock(&policy->transition_lock); + + cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); +} +EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); + +void cpufreq_freq_transition_end(struct cpufreq_policy *policy, + struct cpufreq_freqs *freqs, int transition_failed) +{ + if (unlikely(WARN_ON(!policy->transition_ongoing))) + return; + + cpufreq_notify_post_transition(policy, freqs, transition_failed); + + policy->transition_ongoing = false; + policy->transition_task = NULL; + + wake_up(&policy->transition_wait); +} +EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); + + +/********************************************************************* + * SYSFS INTERFACE * + *********************************************************************/ +static ssize_t show_boost(struct kobject *kobj, + struct attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); +} + +static ssize_t store_boost(struct kobject *kobj, struct attribute *attr, + const char *buf, size_t count) +{ + int ret, enable; + + ret = sscanf(buf, "%d", &enable); + if (ret != 1 || enable < 0 || enable > 1) + return -EINVAL; + + if (cpufreq_boost_trigger_state(enable)) { + pr_err("%s: Cannot %s BOOST!\n", + __func__, enable ? "enable" : "disable"); + return -EINVAL; + } + + pr_debug("%s: cpufreq BOOST %s\n", + __func__, enable ? "enabled" : "disabled"); + + return count; +} +define_one_global_rw(boost); + +static struct cpufreq_governor *find_governor(const char *str_governor) +{ + struct cpufreq_governor *t; + + for_each_governor(t) + if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN)) + return t; + + return NULL; +} + +/** + * cpufreq_parse_governor - parse a governor string + */ +static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, + struct cpufreq_governor **governor) +{ + int err = -EINVAL; + + if (!cpufreq_driver) + goto out; + + if (cpufreq_driver->setpolicy) { + if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { + *policy = CPUFREQ_POLICY_PERFORMANCE; + err = 0; + } else if (!strncasecmp(str_governor, "powersave", + CPUFREQ_NAME_LEN)) { + *policy = CPUFREQ_POLICY_POWERSAVE; + err = 0; + } + } else { + struct cpufreq_governor *t; + + mutex_lock(&cpufreq_governor_mutex); + + t = find_governor(str_governor); + + if (t == NULL) { + int ret; + + mutex_unlock(&cpufreq_governor_mutex); + ret = request_module("cpufreq_%s", str_governor); + mutex_lock(&cpufreq_governor_mutex); + + if (ret == 0) + t = find_governor(str_governor); + } + + if (t != NULL) { + *governor = t; + err = 0; + } + + mutex_unlock(&cpufreq_governor_mutex); + } +out: + return err; +} + +/** + * cpufreq_per_cpu_attr_read() / show_##file_name() - + * print out cpufreq information + * + * Write out information from cpufreq_driver->policy[cpu]; object must be + * "unsigned int". + */ + +#define show_one(file_name, object) \ +static ssize_t show_##file_name \ +(struct cpufreq_policy *policy, char *buf) \ +{ \ + return sprintf(buf, "%u\n", policy->object); \ +} + +show_one(cpuinfo_min_freq, cpuinfo.min_freq); +show_one(cpuinfo_max_freq, cpuinfo.max_freq); +show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); +show_one(scaling_min_freq, min); +show_one(scaling_max_freq, max); + +static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) +{ + ssize_t ret; + + if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) + ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu)); + else + ret = sprintf(buf, "%u\n", policy->cur); + return ret; +} + +static int cpufreq_set_policy(struct cpufreq_policy *policy, + struct cpufreq_policy *new_policy); + +/** + * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access + */ +#define store_one(file_name, object) \ +static ssize_t store_##file_name \ +(struct cpufreq_policy *policy, const char *buf, size_t count) \ +{ \ + int ret, temp; \ + struct cpufreq_policy new_policy; \ + \ + ret = cpufreq_get_policy(&new_policy, policy->cpu); \ + if (ret) \ + return -EINVAL; \ + \ + ret = sscanf(buf, "%u", &new_policy.object); \ + if (ret != 1) \ + return -EINVAL; \ + \ + temp = new_policy.object; \ + ret = cpufreq_set_policy(policy, &new_policy); \ + if (!ret) \ + policy->user_policy.object = temp; \ + \ + return ret ? ret : count; \ +} + +store_one(scaling_min_freq, min); +store_one(scaling_max_freq, max); + +/** + * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware + */ +static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, + char *buf) +{ + unsigned int cur_freq = __cpufreq_get(policy); + if (!cur_freq) + return sprintf(buf, "<unknown>"); + return sprintf(buf, "%u\n", cur_freq); +} + +/** + * show_scaling_governor - show the current policy for the specified CPU + */ +static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) +{ + if (policy->policy == CPUFREQ_POLICY_POWERSAVE) + return sprintf(buf, "powersave\n"); + else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) + return sprintf(buf, "performance\n"); + else if (policy->governor) + return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", + policy->governor->name); + return -EINVAL; +} + +/** + * store_scaling_governor - store policy for the specified CPU + */ +static ssize_t store_scaling_governor(struct cpufreq_policy *policy, + const char *buf, size_t count) +{ + int ret; + char str_governor[16]; + struct cpufreq_policy new_policy; + + ret = cpufreq_get_policy(&new_policy, policy->cpu); + if (ret) + return ret; + + ret = sscanf(buf, "%15s", str_governor); + if (ret != 1) + return -EINVAL; + + if (cpufreq_parse_governor(str_governor, &new_policy.policy, + &new_policy.governor)) + return -EINVAL; + + ret = cpufreq_set_policy(policy, &new_policy); + + policy->user_policy.policy = policy->policy; + policy->user_policy.governor = policy->governor; + + if (ret) + return ret; + else + return count; +} + +/** + * show_scaling_driver - show the cpufreq driver currently loaded + */ +static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) +{ + return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); +} + +/** + * show_scaling_available_governors - show the available CPUfreq governors + */ +static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, + char *buf) +{ + ssize_t i = 0; + struct cpufreq_governor *t; + + if (!has_target()) { + i += sprintf(buf, "performance powersave"); + goto out; + } + + for_each_governor(t) { + if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) + - (CPUFREQ_NAME_LEN + 2))) + goto out; + i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); + } +out: + i += sprintf(&buf[i], "\n"); + return i; +} + +ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) +{ + ssize_t i = 0; + unsigned int cpu; + + for_each_cpu(cpu, mask) { + if (i) + i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); + i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); + if (i >= (PAGE_SIZE - 5)) + break; + } + i += sprintf(&buf[i], "\n"); + return i; +} +EXPORT_SYMBOL_GPL(cpufreq_show_cpus); + +/** + * show_related_cpus - show the CPUs affected by each transition even if + * hw coordination is in use + */ +static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) +{ + return cpufreq_show_cpus(policy->related_cpus, buf); +} + +/** + * show_affected_cpus - show the CPUs affected by each transition + */ +static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) +{ + return cpufreq_show_cpus(policy->cpus, buf); +} + +static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, + const char *buf, size_t count) +{ + unsigned int freq = 0; + unsigned int ret; + + if (!policy->governor || !policy->governor->store_setspeed) + return -EINVAL; + + ret = sscanf(buf, "%u", &freq); + if (ret != 1) + return -EINVAL; + + policy->governor->store_setspeed(policy, freq); + + return count; +} + +static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) +{ + if (!policy->governor || !policy->governor->show_setspeed) + return sprintf(buf, "<unsupported>\n"); + + return policy->governor->show_setspeed(policy, buf); +} + +/** + * show_bios_limit - show the current cpufreq HW/BIOS limitation + */ +static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) +{ + unsigned int limit; + int ret; + if (cpufreq_driver->bios_limit) { + ret = cpufreq_driver->bios_limit(policy->cpu, &limit); + if (!ret) + return sprintf(buf, "%u\n", limit); + } + return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); +} + +cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); +cpufreq_freq_attr_ro(cpuinfo_min_freq); +cpufreq_freq_attr_ro(cpuinfo_max_freq); +cpufreq_freq_attr_ro(cpuinfo_transition_latency); +cpufreq_freq_attr_ro(scaling_available_governors); +cpufreq_freq_attr_ro(scaling_driver); +cpufreq_freq_attr_ro(scaling_cur_freq); +cpufreq_freq_attr_ro(bios_limit); +cpufreq_freq_attr_ro(related_cpus); +cpufreq_freq_attr_ro(affected_cpus); +cpufreq_freq_attr_rw(scaling_min_freq); +cpufreq_freq_attr_rw(scaling_max_freq); +cpufreq_freq_attr_rw(scaling_governor); +cpufreq_freq_attr_rw(scaling_setspeed); + +static struct attribute *default_attrs[] = { + &cpuinfo_min_freq.attr, + &cpuinfo_max_freq.attr, + &cpuinfo_transition_latency.attr, + &scaling_min_freq.attr, + &scaling_max_freq.attr, + &affected_cpus.attr, + &related_cpus.attr, + &scaling_governor.attr, + &scaling_driver.attr, + &scaling_available_governors.attr, + &scaling_setspeed.attr, + NULL +}; + +#define to_policy(k) container_of(k, struct cpufreq_policy, kobj) +#define to_attr(a) container_of(a, struct freq_attr, attr) + +static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) +{ + struct cpufreq_policy *policy = to_policy(kobj); + struct freq_attr *fattr = to_attr(attr); + ssize_t ret; + + down_read(&policy->rwsem); + + if (fattr->show) + ret = fattr->show(policy, buf); + else + ret = -EIO; + + up_read(&policy->rwsem); + + return ret; +} + +static ssize_t store(struct kobject *kobj, struct attribute *attr, + const char *buf, size_t count) +{ + struct cpufreq_policy *policy = to_policy(kobj); + struct freq_attr *fattr = to_attr(attr); + ssize_t ret = -EINVAL; + + get_online_cpus(); + + if (!cpu_online(policy->cpu)) + goto unlock; + + down_write(&policy->rwsem); + + if (fattr->store) + ret = fattr->store(policy, buf, count); + else + ret = -EIO; + + up_write(&policy->rwsem); +unlock: + put_online_cpus(); + + return ret; +} + +static void cpufreq_sysfs_release(struct kobject *kobj) +{ + struct cpufreq_policy *policy = to_policy(kobj); + pr_debug("last reference is dropped\n"); + complete(&policy->kobj_unregister); +} + +static const struct sysfs_ops sysfs_ops = { + .show = show, + .store = store, +}; + +static struct kobj_type ktype_cpufreq = { + .sysfs_ops = &sysfs_ops, + .default_attrs = default_attrs, + .release = cpufreq_sysfs_release, +}; + +struct kobject *cpufreq_global_kobject; +EXPORT_SYMBOL(cpufreq_global_kobject); + +static int cpufreq_global_kobject_usage; + +int cpufreq_get_global_kobject(void) +{ + if (!cpufreq_global_kobject_usage++) + return kobject_add(cpufreq_global_kobject, + &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); + + return 0; +} +EXPORT_SYMBOL(cpufreq_get_global_kobject); + +void cpufreq_put_global_kobject(void) +{ + if (!--cpufreq_global_kobject_usage) + kobject_del(cpufreq_global_kobject); +} +EXPORT_SYMBOL(cpufreq_put_global_kobject); + +int cpufreq_sysfs_create_file(const struct attribute *attr) +{ + int ret = cpufreq_get_global_kobject(); + + if (!ret) { + ret = sysfs_create_file(cpufreq_global_kobject, attr); + if (ret) + cpufreq_put_global_kobject(); + } + + return ret; +} +EXPORT_SYMBOL(cpufreq_sysfs_create_file); + +void cpufreq_sysfs_remove_file(const struct attribute *attr) +{ + sysfs_remove_file(cpufreq_global_kobject, attr); + cpufreq_put_global_kobject(); +} +EXPORT_SYMBOL(cpufreq_sysfs_remove_file); + +/* symlink affected CPUs */ +static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) +{ + unsigned int j; + int ret = 0; + + for_each_cpu(j, policy->cpus) { + struct device *cpu_dev; + + if (j == policy->cpu) + continue; + + pr_debug("Adding link for CPU: %u\n", j); + cpu_dev = get_cpu_device(j); + ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, + "cpufreq"); + if (ret) + break; + } + return ret; +} + +static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, + struct device *dev) +{ + struct freq_attr **drv_attr; + int ret = 0; + + /* set up files for this cpu device */ + drv_attr = cpufreq_driver->attr; + while (drv_attr && *drv_attr) { + ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); + if (ret) + return ret; + drv_attr++; + } + if (cpufreq_driver->get) { + ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); + if (ret) + return ret; + } + + ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); + if (ret) + return ret; + + if (cpufreq_driver->bios_limit) { + ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); + if (ret) + return ret; + } + + return cpufreq_add_dev_symlink(policy); +} + +static void cpufreq_init_policy(struct cpufreq_policy *policy) +{ + struct cpufreq_governor *gov = NULL; + struct cpufreq_policy new_policy; + int ret = 0; + + memcpy(&new_policy, policy, sizeof(*policy)); + + /* Update governor of new_policy to the governor used before hotplug */ + gov = find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu)); + if (gov) + pr_debug("Restoring governor %s for cpu %d\n", + policy->governor->name, policy->cpu); + else + gov = CPUFREQ_DEFAULT_GOVERNOR; + + new_policy.governor = gov; + + /* Use the default policy if its valid. */ + if (cpufreq_driver->setpolicy) + cpufreq_parse_governor(gov->name, &new_policy.policy, NULL); + + /* set default policy */ + ret = cpufreq_set_policy(policy, &new_policy); + if (ret) { + pr_debug("setting policy failed\n"); + if (cpufreq_driver->exit) + cpufreq_driver->exit(policy); + } +} + +static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, + unsigned int cpu, struct device *dev) +{ + int ret = 0; + unsigned long flags; + + if (has_target()) { + ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); + if (ret) { + pr_err("%s: Failed to stop governor\n", __func__); + return ret; + } + } + + down_write(&policy->rwsem); + + write_lock_irqsave(&cpufreq_driver_lock, flags); + + cpumask_set_cpu(cpu, policy->cpus); + per_cpu(cpufreq_cpu_data, cpu) = policy; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + up_write(&policy->rwsem); + + if (has_target()) { + ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); + if (!ret) + ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); + + if (ret) { + pr_err("%s: Failed to start governor\n", __func__); + return ret; + } + } + + return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); +} + +static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) +{ + struct cpufreq_policy *policy; + unsigned long flags; + + read_lock_irqsave(&cpufreq_driver_lock, flags); + + policy = per_cpu(cpufreq_cpu_data_fallback, cpu); + + read_unlock_irqrestore(&cpufreq_driver_lock, flags); + + if (policy) + policy->governor = NULL; + + return policy; +} + +static struct cpufreq_policy *cpufreq_policy_alloc(void) +{ + struct cpufreq_policy *policy; + + policy = kzalloc(sizeof(*policy), GFP_KERNEL); + if (!policy) + return NULL; + + if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) + goto err_free_policy; + + if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) + goto err_free_cpumask; + + INIT_LIST_HEAD(&policy->policy_list); + init_rwsem(&policy->rwsem); + spin_lock_init(&policy->transition_lock); + init_waitqueue_head(&policy->transition_wait); + init_completion(&policy->kobj_unregister); + INIT_WORK(&policy->update, handle_update); + + return policy; + +err_free_cpumask: + free_cpumask_var(policy->cpus); +err_free_policy: + kfree(policy); + + return NULL; +} + +static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) +{ + struct kobject *kobj; + struct completion *cmp; + + blocking_notifier_call_chain(&cpufreq_policy_notifier_list, + CPUFREQ_REMOVE_POLICY, policy); + + down_read(&policy->rwsem); + kobj = &policy->kobj; + cmp = &policy->kobj_unregister; + up_read(&policy->rwsem); + kobject_put(kobj); + + /* + * We need to make sure that the underlying kobj is + * actually not referenced anymore by anybody before we + * proceed with unloading. + */ + pr_debug("waiting for dropping of refcount\n"); + wait_for_completion(cmp); + pr_debug("wait complete\n"); +} + +static void cpufreq_policy_free(struct cpufreq_policy *policy) +{ + free_cpumask_var(policy->related_cpus); + free_cpumask_var(policy->cpus); + kfree(policy); +} + +static int update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu, + struct device *cpu_dev) +{ + int ret; + + if (WARN_ON(cpu == policy->cpu)) + return 0; + + /* Move kobject to the new policy->cpu */ + ret = kobject_move(&policy->kobj, &cpu_dev->kobj); + if (ret) { + pr_err("%s: Failed to move kobj: %d\n", __func__, ret); + return ret; + } + + down_write(&policy->rwsem); + policy->cpu = cpu; + up_write(&policy->rwsem); + + return 0; +} + +static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) +{ + unsigned int j, cpu = dev->id; + int ret = -ENOMEM; + struct cpufreq_policy *policy; + unsigned long flags; + bool recover_policy = cpufreq_suspended; + + if (cpu_is_offline(cpu)) + return 0; + + pr_debug("adding CPU %u\n", cpu); + + /* check whether a different CPU already registered this + * CPU because it is in the same boat. */ + policy = cpufreq_cpu_get_raw(cpu); + if (unlikely(policy)) + return 0; + + /* Check if this cpu was hot-unplugged earlier and has siblings */ + read_lock_irqsave(&cpufreq_driver_lock, flags); + for_each_policy(policy) { + if (cpumask_test_cpu(cpu, policy->related_cpus)) { + read_unlock_irqrestore(&cpufreq_driver_lock, flags); + ret = cpufreq_add_policy_cpu(policy, cpu, dev); + return ret; + } + } + read_unlock_irqrestore(&cpufreq_driver_lock, flags); + + /* + * Restore the saved policy when doing light-weight init and fall back + * to the full init if that fails. + */ + policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL; + if (!policy) { + recover_policy = false; + policy = cpufreq_policy_alloc(); + if (!policy) + goto nomem_out; + } + + /* + * In the resume path, since we restore a saved policy, the assignment + * to policy->cpu is like an update of the existing policy, rather than + * the creation of a brand new one. So we need to perform this update + * by invoking update_policy_cpu(). + */ + if (recover_policy && cpu != policy->cpu) + WARN_ON(update_policy_cpu(policy, cpu, dev)); + else + policy->cpu = cpu; + + cpumask_copy(policy->cpus, cpumask_of(cpu)); + + /* call driver. From then on the cpufreq must be able + * to accept all calls to ->verify and ->setpolicy for this CPU + */ + ret = cpufreq_driver->init(policy); + if (ret) { + pr_debug("initialization failed\n"); + goto err_set_policy_cpu; + } + + down_write(&policy->rwsem); + + /* related cpus should atleast have policy->cpus */ + cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); + + /* + * affected cpus must always be the one, which are online. We aren't + * managing offline cpus here. + */ + cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); + + if (!recover_policy) { + policy->user_policy.min = policy->min; + policy->user_policy.max = policy->max; + + /* prepare interface data */ + ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, + &dev->kobj, "cpufreq"); + if (ret) { + pr_err("%s: failed to init policy->kobj: %d\n", + __func__, ret); + goto err_init_policy_kobj; + } + } + + write_lock_irqsave(&cpufreq_driver_lock, flags); + for_each_cpu(j, policy->cpus) + per_cpu(cpufreq_cpu_data, j) = policy; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { + policy->cur = cpufreq_driver->get(policy->cpu); + if (!policy->cur) { + pr_err("%s: ->get() failed\n", __func__); + goto err_get_freq; + } + } + + /* + * Sometimes boot loaders set CPU frequency to a value outside of + * frequency table present with cpufreq core. In such cases CPU might be + * unstable if it has to run on that frequency for long duration of time + * and so its better to set it to a frequency which is specified in + * freq-table. This also makes cpufreq stats inconsistent as + * cpufreq-stats would fail to register because current frequency of CPU + * isn't found in freq-table. + * + * Because we don't want this change to effect boot process badly, we go + * for the next freq which is >= policy->cur ('cur' must be set by now, + * otherwise we will end up setting freq to lowest of the table as 'cur' + * is initialized to zero). + * + * We are passing target-freq as "policy->cur - 1" otherwise + * __cpufreq_driver_target() would simply fail, as policy->cur will be + * equal to target-freq. + */ + if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) + && has_target()) { + /* Are we running at unknown frequency ? */ + ret = cpufreq_frequency_table_get_index(policy, policy->cur); + if (ret == -EINVAL) { + /* Warn user and fix it */ + pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", + __func__, policy->cpu, policy->cur); + ret = __cpufreq_driver_target(policy, policy->cur - 1, + CPUFREQ_RELATION_L); + + /* + * Reaching here after boot in a few seconds may not + * mean that system will remain stable at "unknown" + * frequency for longer duration. Hence, a BUG_ON(). + */ + BUG_ON(ret); + pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", + __func__, policy->cpu, policy->cur); + } + } + + blocking_notifier_call_chain(&cpufreq_policy_notifier_list, + CPUFREQ_START, policy); + + if (!recover_policy) { + ret = cpufreq_add_dev_interface(policy, dev); + if (ret) + goto err_out_unregister; + blocking_notifier_call_chain(&cpufreq_policy_notifier_list, + CPUFREQ_CREATE_POLICY, policy); + } + + write_lock_irqsave(&cpufreq_driver_lock, flags); + list_add(&policy->policy_list, &cpufreq_policy_list); + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + cpufreq_init_policy(policy); + + if (!recover_policy) { + policy->user_policy.policy = policy->policy; + policy->user_policy.governor = policy->governor; + } + up_write(&policy->rwsem); + + kobject_uevent(&policy->kobj, KOBJ_ADD); + + /* Callback for handling stuff after policy is ready */ + if (cpufreq_driver->ready) + cpufreq_driver->ready(policy); + + pr_debug("initialization complete\n"); + + return 0; + +err_out_unregister: +err_get_freq: + write_lock_irqsave(&cpufreq_driver_lock, flags); + for_each_cpu(j, policy->cpus) + per_cpu(cpufreq_cpu_data, j) = NULL; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + if (!recover_policy) { + kobject_put(&policy->kobj); + wait_for_completion(&policy->kobj_unregister); + } +err_init_policy_kobj: + up_write(&policy->rwsem); + + if (cpufreq_driver->exit) + cpufreq_driver->exit(policy); +err_set_policy_cpu: + if (recover_policy) { + /* Do not leave stale fallback data behind. */ + per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL; + cpufreq_policy_put_kobj(policy); + } + cpufreq_policy_free(policy); + +nomem_out: + return ret; +} + +/** + * cpufreq_add_dev - add a CPU device + * + * Adds the cpufreq interface for a CPU device. + * + * The Oracle says: try running cpufreq registration/unregistration concurrently + * with with cpu hotplugging and all hell will break loose. Tried to clean this + * mess up, but more thorough testing is needed. - Mathieu + */ +static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) +{ + return __cpufreq_add_dev(dev, sif); +} + +static int __cpufreq_remove_dev_prepare(struct device *dev, + struct subsys_interface *sif) +{ + unsigned int cpu = dev->id, cpus; + int ret; + unsigned long flags; + struct cpufreq_policy *policy; + + pr_debug("%s: unregistering CPU %u\n", __func__, cpu); + + write_lock_irqsave(&cpufreq_driver_lock, flags); + + policy = per_cpu(cpufreq_cpu_data, cpu); + + /* Save the policy somewhere when doing a light-weight tear-down */ + if (cpufreq_suspended) + per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; + + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + if (!policy) { + pr_debug("%s: No cpu_data found\n", __func__); + return -EINVAL; + } + + if (has_target()) { + ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); + if (ret) { + pr_err("%s: Failed to stop governor\n", __func__); + return ret; + } + + strncpy(per_cpu(cpufreq_cpu_governor, cpu), + policy->governor->name, CPUFREQ_NAME_LEN); + } + + down_read(&policy->rwsem); + cpus = cpumask_weight(policy->cpus); + up_read(&policy->rwsem); + + if (cpu != policy->cpu) { + sysfs_remove_link(&dev->kobj, "cpufreq"); + } else if (cpus > 1) { + /* Nominate new CPU */ + int new_cpu = cpumask_any_but(policy->cpus, cpu); + struct device *cpu_dev = get_cpu_device(new_cpu); + + sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); + ret = update_policy_cpu(policy, new_cpu, cpu_dev); + if (ret) { + if (sysfs_create_link(&cpu_dev->kobj, &policy->kobj, + "cpufreq")) + pr_err("%s: Failed to restore kobj link to cpu:%d\n", + __func__, cpu_dev->id); + return ret; + } + + if (!cpufreq_suspended) + pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", + __func__, new_cpu, cpu); + } else if (cpufreq_driver->stop_cpu) { + cpufreq_driver->stop_cpu(policy); + } + + return 0; +} + +static int __cpufreq_remove_dev_finish(struct device *dev, + struct subsys_interface *sif) +{ + unsigned int cpu = dev->id, cpus; + int ret; + unsigned long flags; + struct cpufreq_policy *policy; + + write_lock_irqsave(&cpufreq_driver_lock, flags); + policy = per_cpu(cpufreq_cpu_data, cpu); + per_cpu(cpufreq_cpu_data, cpu) = NULL; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + if (!policy) { + pr_debug("%s: No cpu_data found\n", __func__); + return -EINVAL; + } + + down_write(&policy->rwsem); + cpus = cpumask_weight(policy->cpus); + + if (cpus > 1) + cpumask_clear_cpu(cpu, policy->cpus); + up_write(&policy->rwsem); + + /* If cpu is last user of policy, free policy */ + if (cpus == 1) { + if (has_target()) { + ret = __cpufreq_governor(policy, + CPUFREQ_GOV_POLICY_EXIT); + if (ret) { + pr_err("%s: Failed to exit governor\n", + __func__); + return ret; + } + } + + if (!cpufreq_suspended) + cpufreq_policy_put_kobj(policy); + + /* + * Perform the ->exit() even during light-weight tear-down, + * since this is a core component, and is essential for the + * subsequent light-weight ->init() to succeed. + */ + if (cpufreq_driver->exit) + cpufreq_driver->exit(policy); + + /* Remove policy from list of active policies */ + write_lock_irqsave(&cpufreq_driver_lock, flags); + list_del(&policy->policy_list); + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + if (!cpufreq_suspended) + cpufreq_policy_free(policy); + } else if (has_target()) { + ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); + if (!ret) + ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); + + if (ret) { + pr_err("%s: Failed to start governor\n", __func__); + return ret; + } + } + + return 0; +} + +/** + * cpufreq_remove_dev - remove a CPU device + * + * Removes the cpufreq interface for a CPU device. + */ +static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) +{ + unsigned int cpu = dev->id; + int ret; + + if (cpu_is_offline(cpu)) + return 0; + + ret = __cpufreq_remove_dev_prepare(dev, sif); + + if (!ret) + ret = __cpufreq_remove_dev_finish(dev, sif); + + return ret; +} + +static void handle_update(struct work_struct *work) +{ + struct cpufreq_policy *policy = + container_of(work, struct cpufreq_policy, update); + unsigned int cpu = policy->cpu; + pr_debug("handle_update for cpu %u called\n", cpu); + cpufreq_update_policy(cpu); +} + +/** + * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're + * in deep trouble. + * @policy: policy managing CPUs + * @new_freq: CPU frequency the CPU actually runs at + * + * We adjust to current frequency first, and need to clean up later. + * So either call to cpufreq_update_policy() or schedule handle_update()). + */ +static void cpufreq_out_of_sync(struct cpufreq_policy *policy, + unsigned int new_freq) +{ + struct cpufreq_freqs freqs; + + pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", + policy->cur, new_freq); + + freqs.old = policy->cur; + freqs.new = new_freq; + + cpufreq_freq_transition_begin(policy, &freqs); + cpufreq_freq_transition_end(policy, &freqs, 0); +} + +/** + * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur + * @cpu: CPU number + * + * This is the last known freq, without actually getting it from the driver. + * Return value will be same as what is shown in scaling_cur_freq in sysfs. + */ +unsigned int cpufreq_quick_get(unsigned int cpu) +{ + struct cpufreq_policy *policy; + unsigned int ret_freq = 0; + + if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) + return cpufreq_driver->get(cpu); + + policy = cpufreq_cpu_get(cpu); + if (policy) { + ret_freq = policy->cur; + cpufreq_cpu_put(policy); + } + + return ret_freq; +} +EXPORT_SYMBOL(cpufreq_quick_get); + +/** + * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU + * @cpu: CPU number + * + * Just return the max possible frequency for a given CPU. + */ +unsigned int cpufreq_quick_get_max(unsigned int cpu) +{ + struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); + unsigned int ret_freq = 0; + + if (policy) { + ret_freq = policy->max; + cpufreq_cpu_put(policy); + } + + return ret_freq; +} +EXPORT_SYMBOL(cpufreq_quick_get_max); + +static unsigned int __cpufreq_get(struct cpufreq_policy *policy) +{ + unsigned int ret_freq = 0; + + if (!cpufreq_driver->get) + return ret_freq; + + ret_freq = cpufreq_driver->get(policy->cpu); + + if (ret_freq && policy->cur && + !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { + /* verify no discrepancy between actual and + saved value exists */ + if (unlikely(ret_freq != policy->cur)) { + cpufreq_out_of_sync(policy, ret_freq); + schedule_work(&policy->update); + } + } + + return ret_freq; +} + +/** + * cpufreq_get - get the current CPU frequency (in kHz) + * @cpu: CPU number + * + * Get the CPU current (static) CPU frequency + */ +unsigned int cpufreq_get(unsigned int cpu) +{ + struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); + unsigned int ret_freq = 0; + + if (policy) { + down_read(&policy->rwsem); + ret_freq = __cpufreq_get(policy); + up_read(&policy->rwsem); + + cpufreq_cpu_put(policy); + } + + return ret_freq; +} +EXPORT_SYMBOL(cpufreq_get); + +static struct subsys_interface cpufreq_interface = { + .name = "cpufreq", + .subsys = &cpu_subsys, + .add_dev = cpufreq_add_dev, + .remove_dev = cpufreq_remove_dev, +}; + +/* + * In case platform wants some specific frequency to be configured + * during suspend.. + */ +int cpufreq_generic_suspend(struct cpufreq_policy *policy) +{ + int ret; + + if (!policy->suspend_freq) { + pr_err("%s: suspend_freq can't be zero\n", __func__); + return -EINVAL; + } + + pr_debug("%s: Setting suspend-freq: %u\n", __func__, + policy->suspend_freq); + + ret = __cpufreq_driver_target(policy, policy->suspend_freq, + CPUFREQ_RELATION_H); + if (ret) + pr_err("%s: unable to set suspend-freq: %u. err: %d\n", + __func__, policy->suspend_freq, ret); + + return ret; +} +EXPORT_SYMBOL(cpufreq_generic_suspend); + +/** + * cpufreq_suspend() - Suspend CPUFreq governors + * + * Called during system wide Suspend/Hibernate cycles for suspending governors + * as some platforms can't change frequency after this point in suspend cycle. + * Because some of the devices (like: i2c, regulators, etc) they use for + * changing frequency are suspended quickly after this point. + */ +void cpufreq_suspend(void) +{ + struct cpufreq_policy *policy; + + if (!cpufreq_driver) + return; + + if (!has_target()) + goto suspend; + + pr_debug("%s: Suspending Governors\n", __func__); + + for_each_policy(policy) { + if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP)) + pr_err("%s: Failed to stop governor for policy: %p\n", + __func__, policy); + else if (cpufreq_driver->suspend + && cpufreq_driver->suspend(policy)) + pr_err("%s: Failed to suspend driver: %p\n", __func__, + policy); + } + +suspend: + cpufreq_suspended = true; +} + +/** + * cpufreq_resume() - Resume CPUFreq governors + * + * Called during system wide Suspend/Hibernate cycle for resuming governors that + * are suspended with cpufreq_suspend(). + */ +void cpufreq_resume(void) +{ + struct cpufreq_policy *policy; + + if (!cpufreq_driver) + return; + + cpufreq_suspended = false; + + if (!has_target()) + return; + + pr_debug("%s: Resuming Governors\n", __func__); + + for_each_policy(policy) { + if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) + pr_err("%s: Failed to resume driver: %p\n", __func__, + policy); + else if (__cpufreq_governor(policy, CPUFREQ_GOV_START) + || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS)) + pr_err("%s: Failed to start governor for policy: %p\n", + __func__, policy); + } + + /* + * schedule call cpufreq_update_policy() for first-online CPU, as that + * wouldn't be hotplugged-out on suspend. It will verify that the + * current freq is in sync with what we believe it to be. + */ + policy = cpufreq_cpu_get_raw(cpumask_first(cpu_online_mask)); + if (WARN_ON(!policy)) + return; + + schedule_work(&policy->update); +} + +/** + * cpufreq_get_current_driver - return current driver's name + * + * Return the name string of the currently loaded cpufreq driver + * or NULL, if none. + */ +const char *cpufreq_get_current_driver(void) +{ + if (cpufreq_driver) + return cpufreq_driver->name; + + return NULL; +} +EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); + +/** + * cpufreq_get_driver_data - return current driver data + * + * Return the private data of the currently loaded cpufreq + * driver, or NULL if no cpufreq driver is loaded. + */ +void *cpufreq_get_driver_data(void) +{ + if (cpufreq_driver) + return cpufreq_driver->driver_data; + + return NULL; +} +EXPORT_SYMBOL_GPL(cpufreq_get_driver_data); + +/********************************************************************* + * NOTIFIER LISTS INTERFACE * + *********************************************************************/ + +/** + * cpufreq_register_notifier - register a driver with cpufreq + * @nb: notifier function to register + * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER + * + * Add a driver to one of two lists: either a list of drivers that + * are notified about clock rate changes (once before and once after + * the transition), or a list of drivers that are notified about + * changes in cpufreq policy. + * + * This function may sleep, and has the same return conditions as + * blocking_notifier_chain_register. + */ +int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) +{ + int ret; + + if (cpufreq_disabled()) + return -EINVAL; + + WARN_ON(!init_cpufreq_transition_notifier_list_called); + + switch (list) { + case CPUFREQ_TRANSITION_NOTIFIER: + ret = srcu_notifier_chain_register( + &cpufreq_transition_notifier_list, nb); + break; + case CPUFREQ_POLICY_NOTIFIER: + ret = blocking_notifier_chain_register( + &cpufreq_policy_notifier_list, nb); + break; + default: + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL(cpufreq_register_notifier); + +/** + * cpufreq_unregister_notifier - unregister a driver with cpufreq + * @nb: notifier block to be unregistered + * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER + * + * Remove a driver from the CPU frequency notifier list. + * + * This function may sleep, and has the same return conditions as + * blocking_notifier_chain_unregister. + */ +int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) +{ + int ret; + + if (cpufreq_disabled()) + return -EINVAL; + + switch (list) { + case CPUFREQ_TRANSITION_NOTIFIER: + ret = srcu_notifier_chain_unregister( + &cpufreq_transition_notifier_list, nb); + break; + case CPUFREQ_POLICY_NOTIFIER: + ret = blocking_notifier_chain_unregister( + &cpufreq_policy_notifier_list, nb); + break; + default: + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL(cpufreq_unregister_notifier); + + +/********************************************************************* + * GOVERNORS * + *********************************************************************/ + +/* Must set freqs->new to intermediate frequency */ +static int __target_intermediate(struct cpufreq_policy *policy, + struct cpufreq_freqs *freqs, int index) +{ + int ret; + + freqs->new = cpufreq_driver->get_intermediate(policy, index); + + /* We don't need to switch to intermediate freq */ + if (!freqs->new) + return 0; + + pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", + __func__, policy->cpu, freqs->old, freqs->new); + + cpufreq_freq_transition_begin(policy, freqs); + ret = cpufreq_driver->target_intermediate(policy, index); + cpufreq_freq_transition_end(policy, freqs, ret); + + if (ret) + pr_err("%s: Failed to change to intermediate frequency: %d\n", + __func__, ret); + + return ret; +} + +static int __target_index(struct cpufreq_policy *policy, + struct cpufreq_frequency_table *freq_table, int index) +{ + struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; + unsigned int intermediate_freq = 0; + int retval = -EINVAL; + bool notify; + + notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); + if (notify) { + /* Handle switching to intermediate frequency */ + if (cpufreq_driver->get_intermediate) { + retval = __target_intermediate(policy, &freqs, index); + if (retval) + return retval; + + intermediate_freq = freqs.new; + /* Set old freq to intermediate */ + if (intermediate_freq) + freqs.old = freqs.new; + } + + freqs.new = freq_table[index].frequency; + pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", + __func__, policy->cpu, freqs.old, freqs.new); + + cpufreq_freq_transition_begin(policy, &freqs); + } + + retval = cpufreq_driver->target_index(policy, index); + if (retval) + pr_err("%s: Failed to change cpu frequency: %d\n", __func__, + retval); + + if (notify) { + cpufreq_freq_transition_end(policy, &freqs, retval); + + /* + * Failed after setting to intermediate freq? Driver should have + * reverted back to initial frequency and so should we. Check + * here for intermediate_freq instead of get_intermediate, in + * case we have't switched to intermediate freq at all. + */ + if (unlikely(retval && intermediate_freq)) { + freqs.old = intermediate_freq; + freqs.new = policy->restore_freq; + cpufreq_freq_transition_begin(policy, &freqs); + cpufreq_freq_transition_end(policy, &freqs, 0); + } + } + + return retval; +} + +int __cpufreq_driver_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + unsigned int old_target_freq = target_freq; + int retval = -EINVAL; + + if (cpufreq_disabled()) + return -ENODEV; + + /* Make sure that target_freq is within supported range */ + if (target_freq > policy->max) + target_freq = policy->max; + if (target_freq < policy->min) + target_freq = policy->min; + + pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", + policy->cpu, target_freq, relation, old_target_freq); + + /* + * This might look like a redundant call as we are checking it again + * after finding index. But it is left intentionally for cases where + * exactly same freq is called again and so we can save on few function + * calls. + */ + if (target_freq == policy->cur) + return 0; + + /* Save last value to restore later on errors */ + policy->restore_freq = policy->cur; + + if (cpufreq_driver->target) + retval = cpufreq_driver->target(policy, target_freq, relation); + else if (cpufreq_driver->target_index) { + struct cpufreq_frequency_table *freq_table; + int index; + + freq_table = cpufreq_frequency_get_table(policy->cpu); + if (unlikely(!freq_table)) { + pr_err("%s: Unable to find freq_table\n", __func__); + goto out; + } + + retval = cpufreq_frequency_table_target(policy, freq_table, + target_freq, relation, &index); + if (unlikely(retval)) { + pr_err("%s: Unable to find matching freq\n", __func__); + goto out; + } + + if (freq_table[index].frequency == policy->cur) { + retval = 0; + goto out; + } + + retval = __target_index(policy, freq_table, index); + } + +out: + return retval; +} +EXPORT_SYMBOL_GPL(__cpufreq_driver_target); + +int cpufreq_driver_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + int ret = -EINVAL; + + down_write(&policy->rwsem); + + ret = __cpufreq_driver_target(policy, target_freq, relation); + + up_write(&policy->rwsem); + + return ret; +} +EXPORT_SYMBOL_GPL(cpufreq_driver_target); + +static int __cpufreq_governor(struct cpufreq_policy *policy, + unsigned int event) +{ + int ret; + + /* Only must be defined when default governor is known to have latency + restrictions, like e.g. conservative or ondemand. + That this is the case is already ensured in Kconfig + */ +#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE + struct cpufreq_governor *gov = &cpufreq_gov_performance; +#else + struct cpufreq_governor *gov = NULL; +#endif + + /* Don't start any governor operations if we are entering suspend */ + if (cpufreq_suspended) + return 0; + /* + * Governor might not be initiated here if ACPI _PPC changed + * notification happened, so check it. + */ + if (!policy->governor) + return -EINVAL; + + if (policy->governor->max_transition_latency && + policy->cpuinfo.transition_latency > + policy->governor->max_transition_latency) { + if (!gov) + return -EINVAL; + else { + pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n", + policy->governor->name, gov->name); + policy->governor = gov; + } + } + + if (event == CPUFREQ_GOV_POLICY_INIT) + if (!try_module_get(policy->governor->owner)) + return -EINVAL; + + pr_debug("__cpufreq_governor for CPU %u, event %u\n", + policy->cpu, event); + + mutex_lock(&cpufreq_governor_lock); + if ((policy->governor_enabled && event == CPUFREQ_GOV_START) + || (!policy->governor_enabled + && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { + mutex_unlock(&cpufreq_governor_lock); + return -EBUSY; + } + + if (event == CPUFREQ_GOV_STOP) + policy->governor_enabled = false; + else if (event == CPUFREQ_GOV_START) + policy->governor_enabled = true; + + mutex_unlock(&cpufreq_governor_lock); + + ret = policy->governor->governor(policy, event); + + if (!ret) { + if (event == CPUFREQ_GOV_POLICY_INIT) + policy->governor->initialized++; + else if (event == CPUFREQ_GOV_POLICY_EXIT) + policy->governor->initialized--; + } else { + /* Restore original values */ + mutex_lock(&cpufreq_governor_lock); + if (event == CPUFREQ_GOV_STOP) + policy->governor_enabled = true; + else if (event == CPUFREQ_GOV_START) + policy->governor_enabled = false; + mutex_unlock(&cpufreq_governor_lock); + } + + if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || + ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) + module_put(policy->governor->owner); + + return ret; +} + +int cpufreq_register_governor(struct cpufreq_governor *governor) +{ + int err; + + if (!governor) + return -EINVAL; + + if (cpufreq_disabled()) + return -ENODEV; + + mutex_lock(&cpufreq_governor_mutex); + + governor->initialized = 0; + err = -EBUSY; + if (!find_governor(governor->name)) { + err = 0; + list_add(&governor->governor_list, &cpufreq_governor_list); + } + + mutex_unlock(&cpufreq_governor_mutex); + return err; +} +EXPORT_SYMBOL_GPL(cpufreq_register_governor); + +void cpufreq_unregister_governor(struct cpufreq_governor *governor) +{ + int cpu; + + if (!governor) + return; + + if (cpufreq_disabled()) + return; + + for_each_present_cpu(cpu) { + if (cpu_online(cpu)) + continue; + if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) + strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); + } + + mutex_lock(&cpufreq_governor_mutex); + list_del(&governor->governor_list); + mutex_unlock(&cpufreq_governor_mutex); + return; +} +EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); + + +/********************************************************************* + * POLICY INTERFACE * + *********************************************************************/ + +/** + * cpufreq_get_policy - get the current cpufreq_policy + * @policy: struct cpufreq_policy into which the current cpufreq_policy + * is written + * + * Reads the current cpufreq policy. + */ +int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) +{ + struct cpufreq_policy *cpu_policy; + if (!policy) + return -EINVAL; + + cpu_policy = cpufreq_cpu_get(cpu); + if (!cpu_policy) + return -EINVAL; + + memcpy(policy, cpu_policy, sizeof(*policy)); + + cpufreq_cpu_put(cpu_policy); + return 0; +} +EXPORT_SYMBOL(cpufreq_get_policy); + +/* + * policy : current policy. + * new_policy: policy to be set. + */ +static int cpufreq_set_policy(struct cpufreq_policy *policy, + struct cpufreq_policy *new_policy) +{ + struct cpufreq_governor *old_gov; + int ret; + + pr_debug("setting new policy for CPU %u: %u - %u kHz\n", + new_policy->cpu, new_policy->min, new_policy->max); + + memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); + + if (new_policy->min > policy->max || new_policy->max < policy->min) + return -EINVAL; + + /* verify the cpu speed can be set within this limit */ + ret = cpufreq_driver->verify(new_policy); + if (ret) + return ret; + + /* adjust if necessary - all reasons */ + blocking_notifier_call_chain(&cpufreq_policy_notifier_list, + CPUFREQ_ADJUST, new_policy); + + /* adjust if necessary - hardware incompatibility*/ + blocking_notifier_call_chain(&cpufreq_policy_notifier_list, + CPUFREQ_INCOMPATIBLE, new_policy); + + /* + * verify the cpu speed can be set within this limit, which might be + * different to the first one + */ + ret = cpufreq_driver->verify(new_policy); + if (ret) + return ret; + + /* notification of the new policy */ + blocking_notifier_call_chain(&cpufreq_policy_notifier_list, + CPUFREQ_NOTIFY, new_policy); + + policy->min = new_policy->min; + policy->max = new_policy->max; + + pr_debug("new min and max freqs are %u - %u kHz\n", + policy->min, policy->max); + + if (cpufreq_driver->setpolicy) { + policy->policy = new_policy->policy; + pr_debug("setting range\n"); + return cpufreq_driver->setpolicy(new_policy); + } + + if (new_policy->governor == policy->governor) + goto out; + + pr_debug("governor switch\n"); + + /* save old, working values */ + old_gov = policy->governor; + /* end old governor */ + if (old_gov) { + __cpufreq_governor(policy, CPUFREQ_GOV_STOP); + up_write(&policy->rwsem); + __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); + down_write(&policy->rwsem); + } + + /* start new governor */ + policy->governor = new_policy->governor; + if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { + if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) + goto out; + + up_write(&policy->rwsem); + __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); + down_write(&policy->rwsem); + } + + /* new governor failed, so re-start old one */ + pr_debug("starting governor %s failed\n", policy->governor->name); + if (old_gov) { + policy->governor = old_gov; + __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT); + __cpufreq_governor(policy, CPUFREQ_GOV_START); + } + + return -EINVAL; + + out: + pr_debug("governor: change or update limits\n"); + return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); +} + +/** + * cpufreq_update_policy - re-evaluate an existing cpufreq policy + * @cpu: CPU which shall be re-evaluated + * + * Useful for policy notifiers which have different necessities + * at different times. + */ +int cpufreq_update_policy(unsigned int cpu) +{ + struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); + struct cpufreq_policy new_policy; + int ret; + + if (!policy) + return -ENODEV; + + down_write(&policy->rwsem); + + pr_debug("updating policy for CPU %u\n", cpu); + memcpy(&new_policy, policy, sizeof(*policy)); + new_policy.min = policy->user_policy.min; + new_policy.max = policy->user_policy.max; + new_policy.policy = policy->user_policy.policy; + new_policy.governor = policy->user_policy.governor; + + /* + * BIOS might change freq behind our back + * -> ask driver for current freq and notify governors about a change + */ + if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { + new_policy.cur = cpufreq_driver->get(cpu); + if (WARN_ON(!new_policy.cur)) { + ret = -EIO; + goto unlock; + } + + if (!policy->cur) { + pr_debug("Driver did not initialize current freq\n"); + policy->cur = new_policy.cur; + } else { + if (policy->cur != new_policy.cur && has_target()) + cpufreq_out_of_sync(policy, new_policy.cur); + } + } + + ret = cpufreq_set_policy(policy, &new_policy); + +unlock: + up_write(&policy->rwsem); + + cpufreq_cpu_put(policy); + return ret; +} +EXPORT_SYMBOL(cpufreq_update_policy); + +static int cpufreq_cpu_callback(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + unsigned int cpu = (unsigned long)hcpu; + struct device *dev; + + dev = get_cpu_device(cpu); + if (dev) { + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_ONLINE: + __cpufreq_add_dev(dev, NULL); + break; + + case CPU_DOWN_PREPARE: + __cpufreq_remove_dev_prepare(dev, NULL); + break; + + case CPU_POST_DEAD: + __cpufreq_remove_dev_finish(dev, NULL); + break; + + case CPU_DOWN_FAILED: + __cpufreq_add_dev(dev, NULL); + break; + } + } + return NOTIFY_OK; +} + +static struct notifier_block __refdata cpufreq_cpu_notifier = { + .notifier_call = cpufreq_cpu_callback, +}; + +/********************************************************************* + * BOOST * + *********************************************************************/ +static int cpufreq_boost_set_sw(int state) +{ + struct cpufreq_frequency_table *freq_table; + struct cpufreq_policy *policy; + int ret = -EINVAL; + + for_each_policy(policy) { + freq_table = cpufreq_frequency_get_table(policy->cpu); + if (freq_table) { + ret = cpufreq_frequency_table_cpuinfo(policy, + freq_table); + if (ret) { + pr_err("%s: Policy frequency update failed\n", + __func__); + break; + } + policy->user_policy.max = policy->max; + __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); + } + } + + return ret; +} + +int cpufreq_boost_trigger_state(int state) +{ + unsigned long flags; + int ret = 0; + + if (cpufreq_driver->boost_enabled == state) + return 0; + + write_lock_irqsave(&cpufreq_driver_lock, flags); + cpufreq_driver->boost_enabled = state; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + ret = cpufreq_driver->set_boost(state); + if (ret) { + write_lock_irqsave(&cpufreq_driver_lock, flags); + cpufreq_driver->boost_enabled = !state; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + pr_err("%s: Cannot %s BOOST\n", + __func__, state ? "enable" : "disable"); + } + + return ret; +} + +int cpufreq_boost_supported(void) +{ + if (likely(cpufreq_driver)) + return cpufreq_driver->boost_supported; + + return 0; +} +EXPORT_SYMBOL_GPL(cpufreq_boost_supported); + +int cpufreq_boost_enabled(void) +{ + return cpufreq_driver->boost_enabled; +} +EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); + +/********************************************************************* + * REGISTER / UNREGISTER CPUFREQ DRIVER * + *********************************************************************/ + +/** + * cpufreq_register_driver - register a CPU Frequency driver + * @driver_data: A struct cpufreq_driver containing the values# + * submitted by the CPU Frequency driver. + * + * Registers a CPU Frequency driver to this core code. This code + * returns zero on success, -EBUSY when another driver got here first + * (and isn't unregistered in the meantime). + * + */ +int cpufreq_register_driver(struct cpufreq_driver *driver_data) +{ + unsigned long flags; + int ret; + + if (cpufreq_disabled()) + return -ENODEV; + + if (!driver_data || !driver_data->verify || !driver_data->init || + !(driver_data->setpolicy || driver_data->target_index || + driver_data->target) || + (driver_data->setpolicy && (driver_data->target_index || + driver_data->target)) || + (!!driver_data->get_intermediate != !!driver_data->target_intermediate)) + return -EINVAL; + + pr_debug("trying to register driver %s\n", driver_data->name); + + write_lock_irqsave(&cpufreq_driver_lock, flags); + if (cpufreq_driver) { + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + return -EEXIST; + } + cpufreq_driver = driver_data; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + + if (driver_data->setpolicy) + driver_data->flags |= CPUFREQ_CONST_LOOPS; + + if (cpufreq_boost_supported()) { + /* + * Check if driver provides function to enable boost - + * if not, use cpufreq_boost_set_sw as default + */ + if (!cpufreq_driver->set_boost) + cpufreq_driver->set_boost = cpufreq_boost_set_sw; + + ret = cpufreq_sysfs_create_file(&boost.attr); + if (ret) { + pr_err("%s: cannot register global BOOST sysfs file\n", + __func__); + goto err_null_driver; + } + } + + ret = subsys_interface_register(&cpufreq_interface); + if (ret) + goto err_boost_unreg; + + if (!(cpufreq_driver->flags & CPUFREQ_STICKY) && + list_empty(&cpufreq_policy_list)) { + /* if all ->init() calls failed, unregister */ + pr_debug("%s: No CPU initialized for driver %s\n", __func__, + driver_data->name); + goto err_if_unreg; + } + + register_hotcpu_notifier(&cpufreq_cpu_notifier); + pr_debug("driver %s up and running\n", driver_data->name); + + return 0; +err_if_unreg: + subsys_interface_unregister(&cpufreq_interface); +err_boost_unreg: + if (cpufreq_boost_supported()) + cpufreq_sysfs_remove_file(&boost.attr); +err_null_driver: + write_lock_irqsave(&cpufreq_driver_lock, flags); + cpufreq_driver = NULL; + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + return ret; +} +EXPORT_SYMBOL_GPL(cpufreq_register_driver); + +/** + * cpufreq_unregister_driver - unregister the current CPUFreq driver + * + * Unregister the current CPUFreq driver. Only call this if you have + * the right to do so, i.e. if you have succeeded in initialising before! + * Returns zero if successful, and -EINVAL if the cpufreq_driver is + * currently not initialised. + */ +int cpufreq_unregister_driver(struct cpufreq_driver *driver) +{ + unsigned long flags; + + if (!cpufreq_driver || (driver != cpufreq_driver)) + return -EINVAL; + + pr_debug("unregistering driver %s\n", driver->name); + + /* Protect against concurrent cpu hotplug */ + get_online_cpus(); + subsys_interface_unregister(&cpufreq_interface); + if (cpufreq_boost_supported()) + cpufreq_sysfs_remove_file(&boost.attr); + + unregister_hotcpu_notifier(&cpufreq_cpu_notifier); + + write_lock_irqsave(&cpufreq_driver_lock, flags); + + cpufreq_driver = NULL; + + write_unlock_irqrestore(&cpufreq_driver_lock, flags); + put_online_cpus(); + + return 0; +} +EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); + +/* + * Stop cpufreq at shutdown to make sure it isn't holding any locks + * or mutexes when secondary CPUs are halted. + */ +static struct syscore_ops cpufreq_syscore_ops = { + .shutdown = cpufreq_suspend, +}; + +static int __init cpufreq_core_init(void) +{ + if (cpufreq_disabled()) + return -ENODEV; + + cpufreq_global_kobject = kobject_create(); + BUG_ON(!cpufreq_global_kobject); + + register_syscore_ops(&cpufreq_syscore_ops); + + return 0; +} +core_initcall(cpufreq_core_init); |