[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/drivers/cpufreq/cpufreq.c b/ap/os/linux/linux-3.4.x/drivers/cpufreq/cpufreq.c
new file mode 100644
index 0000000..cf864ef
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/cpufreq/cpufreq.c
@@ -0,0 +1,1950 @@
+/*
+ * linux/drivers/cpufreq/cpufreq.c
+ *
+ * Copyright (C) 2001 Russell King
+ * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
+ *
+ * Oct 2005 - Ashok Raj <ashok.raj@intel.com>
+ * Added handling for CPU hotplug
+ * Feb 2006 - Jacob Shin <jacob.shin@amd.com>
+ * Fix handling for CPU hotplug -- affected CPUs
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/notifier.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/completion.h>
+#include <linux/mutex.h>
+#include <linux/syscore_ops.h>
+
+#include <trace/events/power.h>
+
+/**
+ * The "cpufreq driver" - the arch- or hardware-dependent low
+ * level driver of CPUFreq support, and its spinlock. This lock
+ * also protects the cpufreq_cpu_data array.
+ */
+static struct cpufreq_driver *cpufreq_driver;
+static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
+#ifdef CONFIG_HOTPLUG_CPU
+/* This one keeps track of the previously set governor of a removed CPU */
+static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
+#endif
+static DEFINE_SPINLOCK(cpufreq_driver_lock);
+
+/*
+ * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure
+ * all cpufreq/hotplug/workqueue/etc related lock issues.
+ *
+ * The rules for this semaphore:
+ * - Any routine that wants to read from the policy structure will
+ * do a down_read on this semaphore.
+ * - Any routine that will write to the policy structure and/or may take away
+ * the policy altogether (eg. CPU hotplug), will hold this lock in write
+ * mode before doing so.
+ *
+ * Additional rules:
+ * - All holders of the lock should check to make sure that the CPU they
+ * are concerned with are online after they get the lock.
+ * - Governor routines that can be called in cpufreq hotplug path should not
+ * take this sem as top level hotplug notifier handler takes this.
+ * - Lock should not be held across
+ * __cpufreq_governor(data, CPUFREQ_GOV_STOP);
+ */
+static DEFINE_PER_CPU(int, cpufreq_policy_cpu);
+static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem);
+
+#define lock_policy_rwsem(mode, cpu) \
+static int lock_policy_rwsem_##mode \
+(int cpu) \
+{ \
+ int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \
+ BUG_ON(policy_cpu == -1); \
+ down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
+ if (unlikely(!cpu_online(cpu))) { \
+ up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
+ return -1; \
+ } \
+ \
+ return 0; \
+}
+
+lock_policy_rwsem(read, cpu);
+
+lock_policy_rwsem(write, cpu);
+
+static void unlock_policy_rwsem_read(int cpu)
+{
+ int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);
+ BUG_ON(policy_cpu == -1);
+ up_read(&per_cpu(cpu_policy_rwsem, policy_cpu));
+}
+
+static void unlock_policy_rwsem_write(int cpu)
+{
+ int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);
+ BUG_ON(policy_cpu == -1);
+ up_write(&per_cpu(cpu_policy_rwsem, policy_cpu));
+}
+
+
+/* internal prototypes */
+static int __cpufreq_governor(struct cpufreq_policy *policy,
+ unsigned int event);
+static unsigned int __cpufreq_get(unsigned int cpu);
+static void handle_update(struct work_struct *work);
+
+/**
+ * Two notifier lists: the "policy" list is involved in the
+ * validation process for a new CPU frequency policy; the
+ * "transition" list for kernel code that needs to handle
+ * changes to devices when the CPU clock speed changes.
+ * The mutex locks both lists.
+ */
+static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
+static struct srcu_notifier_head cpufreq_transition_notifier_list;
+
+static bool init_cpufreq_transition_notifier_list_called;
+static int __init init_cpufreq_transition_notifier_list(void)
+{
+ srcu_init_notifier_head(&cpufreq_transition_notifier_list);
+ init_cpufreq_transition_notifier_list_called = true;
+ return 0;
+}
+pure_initcall(init_cpufreq_transition_notifier_list);
+
+static int off __read_mostly;
+int cpufreq_disabled(void)
+{
+ return off;
+}
+void disable_cpufreq(void)
+{
+ off = 1;
+}
+static LIST_HEAD(cpufreq_governor_list);
+static DEFINE_MUTEX(cpufreq_governor_mutex);
+
+struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
+{
+ struct cpufreq_policy *data;
+ unsigned long flags;
+
+ if (cpu >= nr_cpu_ids)
+ goto err_out;
+
+ /* get the cpufreq driver */
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+
+ if (!cpufreq_driver)
+ goto err_out_unlock;
+
+ if (!try_module_get(cpufreq_driver->owner))
+ goto err_out_unlock;
+
+
+ /* get the CPU */
+ data = per_cpu(cpufreq_cpu_data, cpu);
+
+ if (!data)
+ goto err_out_put_module;
+
+ if (!kobject_get(&data->kobj))
+ goto err_out_put_module;
+
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ return data;
+
+err_out_put_module:
+ module_put(cpufreq_driver->owner);
+err_out_unlock:
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+err_out:
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
+
+
+void cpufreq_cpu_put(struct cpufreq_policy *data)
+{
+ kobject_put(&data->kobj);
+ module_put(cpufreq_driver->owner);
+}
+EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
+
+
+/*********************************************************************
+ * EXTERNALLY AFFECTING FREQUENCY CHANGES *
+ *********************************************************************/
+
+/**
+ * adjust_jiffies - adjust the system "loops_per_jiffy"
+ *
+ * This function alters the system "loops_per_jiffy" for the clock
+ * speed change. Note that loops_per_jiffy cannot be updated on SMP
+ * systems as each CPU might be scaled differently. So, use the arch
+ * per-CPU loops_per_jiffy value wherever possible.
+ */
+#ifndef CONFIG_SMP
+static unsigned long l_p_j_ref;
+static unsigned int l_p_j_ref_freq;
+
+static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
+{
+ if (ci->flags & CPUFREQ_CONST_LOOPS)
+ return;
+
+ if (!l_p_j_ref_freq) {
+ l_p_j_ref = loops_per_jiffy;
+ l_p_j_ref_freq = ci->old;
+ pr_debug("saving %lu as reference value for loops_per_jiffy; "
+ "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq);
+ }
+ if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) ||
+ (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) {
+ loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
+ ci->new);
+ pr_debug("scaling loops_per_jiffy to %lu "
+ "for frequency %u kHz\n", loops_per_jiffy, ci->new);
+ }
+}
+#else
+static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
+{
+ return;
+}
+#endif
+
+
+/**
+ * cpufreq_notify_transition - call notifier chain and adjust_jiffies
+ * on frequency transition.
+ *
+ * This function calls the transition notifiers and the "adjust_jiffies"
+ * function. It is called twice on all CPU frequency changes that have
+ * external effects.
+ */
+void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
+{
+ struct cpufreq_policy *policy;
+
+ BUG_ON(irqs_disabled());
+
+ freqs->flags = cpufreq_driver->flags;
+ pr_debug("notification %u of frequency transition to %u kHz\n",
+ state, freqs->new);
+
+ policy = per_cpu(cpufreq_cpu_data, freqs->cpu);
+ switch (state) {
+
+ case CPUFREQ_PRECHANGE:
+ /* detect if the driver reported a value as "old frequency"
+ * which is not equal to what the cpufreq core thinks is
+ * "old frequency".
+ */
+ if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
+ if ((policy) && (policy->cpu == freqs->cpu) &&
+ (policy->cur) && (policy->cur != freqs->old)) {
+ pr_debug("Warning: CPU frequency is"
+ " %u, cpufreq assumed %u kHz.\n",
+ freqs->old, policy->cur);
+ freqs->old = policy->cur;
+ }
+ }
+ srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
+ CPUFREQ_PRECHANGE, freqs);
+ adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
+ break;
+
+ case CPUFREQ_POSTCHANGE:
+ adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
+ pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new,
+ (unsigned long)freqs->cpu);
+ trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu);
+ trace_cpu_frequency(freqs->new, freqs->cpu);
+ srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
+ CPUFREQ_POSTCHANGE, freqs);
+ if (likely(policy) && likely(policy->cpu == freqs->cpu))
+ policy->cur = freqs->new;
+ break;
+ }
+}
+EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
+
+
+
+/*********************************************************************
+ * SYSFS INTERFACE *
+ *********************************************************************/
+
+static struct cpufreq_governor *__find_governor(const char *str_governor)
+{
+ struct cpufreq_governor *t;
+
+ list_for_each_entry(t, &cpufreq_governor_list, governor_list)
+ if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN))
+ return t;
+
+ return NULL;
+}
+
+/**
+ * cpufreq_parse_governor - parse a governor string
+ */
+static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
+ struct cpufreq_governor **governor)
+{
+ int err = -EINVAL;
+
+ if (!cpufreq_driver)
+ goto out;
+
+ if (cpufreq_driver->setpolicy) {
+ if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
+ *policy = CPUFREQ_POLICY_PERFORMANCE;
+ err = 0;
+ } else if (!strnicmp(str_governor, "powersave",
+ CPUFREQ_NAME_LEN)) {
+ *policy = CPUFREQ_POLICY_POWERSAVE;
+ err = 0;
+ }
+ } else if (cpufreq_driver->target) {
+ struct cpufreq_governor *t;
+
+ mutex_lock(&cpufreq_governor_mutex);
+
+ t = __find_governor(str_governor);
+
+ if (t == NULL) {
+ int ret;
+
+ mutex_unlock(&cpufreq_governor_mutex);
+ ret = request_module("cpufreq_%s", str_governor);
+ mutex_lock(&cpufreq_governor_mutex);
+
+ if (ret == 0)
+ t = __find_governor(str_governor);
+ }
+
+ if (t != NULL) {
+ *governor = t;
+ err = 0;
+ }
+
+ mutex_unlock(&cpufreq_governor_mutex);
+ }
+out:
+ return err;
+}
+
+
+/**
+ * cpufreq_per_cpu_attr_read() / show_##file_name() -
+ * print out cpufreq information
+ *
+ * Write out information from cpufreq_driver->policy[cpu]; object must be
+ * "unsigned int".
+ */
+
+#define show_one(file_name, object) \
+static ssize_t show_##file_name \
+(struct cpufreq_policy *policy, char *buf) \
+{ \
+ return sprintf(buf, "%u\n", policy->object); \
+}
+
+show_one(cpuinfo_min_freq, cpuinfo.min_freq);
+show_one(cpuinfo_max_freq, cpuinfo.max_freq);
+show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
+show_one(scaling_min_freq, min);
+show_one(scaling_max_freq, max);
+
+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 *data,
+ struct cpufreq_policy *policy);
+
+/**
+ * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
+ */
+#define store_one(file_name, object) \
+static ssize_t store_##file_name \
+(struct cpufreq_policy *policy, const char *buf, size_t count) \
+{ \
+ unsigned int ret = -EINVAL; \
+ struct cpufreq_policy new_policy; \
+ \
+ ret = cpufreq_get_policy(&new_policy, policy->cpu); \
+ if (ret) \
+ return -EINVAL; \
+ \
+ ret = sscanf(buf, "%u", &new_policy.object); \
+ if (ret != 1) \
+ return -EINVAL; \
+ \
+ ret = __cpufreq_set_policy(policy, &new_policy); \
+ policy->user_policy.object = policy->object; \
+ \
+ return ret ? ret : count; \
+}
+
+store_one(scaling_min_freq, min);
+store_one(scaling_max_freq, max);
+
+/**
+ * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
+ */
+static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
+ char *buf)
+{
+ unsigned int cur_freq = __cpufreq_get(policy->cpu);
+ if (!cur_freq)
+ return sprintf(buf, "<unknown>");
+ return sprintf(buf, "%u\n", cur_freq);
+}
+
+
+/**
+ * show_scaling_governor - show the current policy for the specified CPU
+ */
+static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
+{
+ if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
+ return sprintf(buf, "powersave\n");
+ else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
+ return sprintf(buf, "performance\n");
+ else if (policy->governor)
+ return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n",
+ policy->governor->name);
+ return -EINVAL;
+}
+
+
+/**
+ * store_scaling_governor - store policy for the specified CPU
+ */
+static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
+ const char *buf, size_t count)
+{
+ unsigned int ret = -EINVAL;
+ char str_governor[16];
+ struct cpufreq_policy new_policy;
+
+ ret = cpufreq_get_policy(&new_policy, policy->cpu);
+ if (ret)
+ return ret;
+
+ ret = sscanf(buf, "%15s", str_governor);
+ if (ret != 1)
+ return -EINVAL;
+
+ if (cpufreq_parse_governor(str_governor, &new_policy.policy,
+ &new_policy.governor))
+ return -EINVAL;
+
+ /* Do not use cpufreq_set_policy here or the user_policy.max
+ will be wrongly overridden */
+ ret = __cpufreq_set_policy(policy, &new_policy);
+
+ policy->user_policy.policy = policy->policy;
+ policy->user_policy.governor = policy->governor;
+
+ if (ret)
+ return ret;
+ else
+ return count;
+}
+
+/**
+ * show_scaling_driver - show the cpufreq driver currently loaded
+ */
+static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
+{
+ return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
+}
+
+/**
+ * show_scaling_available_governors - show the available CPUfreq governors
+ */
+static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
+ char *buf)
+{
+ ssize_t i = 0;
+ struct cpufreq_governor *t;
+
+ if (!cpufreq_driver->target) {
+ i += sprintf(buf, "performance powersave");
+ goto out;
+ }
+
+ list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
+ if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
+ - (CPUFREQ_NAME_LEN + 2)))
+ goto out;
+ i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
+ }
+out:
+ i += sprintf(&buf[i], "\n");
+ return i;
+}
+
+static ssize_t show_cpus(const struct cpumask *mask, char *buf)
+{
+ ssize_t i = 0;
+ unsigned int cpu;
+
+ for_each_cpu(cpu, mask) {
+ if (i)
+ i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
+ i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
+ if (i >= (PAGE_SIZE - 5))
+ break;
+ }
+ i += sprintf(&buf[i], "\n");
+ return i;
+}
+
+/**
+ * show_related_cpus - show the CPUs affected by each transition even if
+ * hw coordination is in use
+ */
+static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
+{
+ if (cpumask_empty(policy->related_cpus))
+ return show_cpus(policy->cpus, buf);
+ return show_cpus(policy->related_cpus, buf);
+}
+
+/**
+ * show_affected_cpus - show the CPUs affected by each transition
+ */
+static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
+{
+ return show_cpus(policy->cpus, buf);
+}
+
+static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
+ const char *buf, size_t count)
+{
+ unsigned int freq = 0;
+ unsigned int ret;
+
+ if (!policy->governor || !policy->governor->store_setspeed)
+ return -EINVAL;
+
+ ret = sscanf(buf, "%u", &freq);
+ if (ret != 1)
+ return -EINVAL;
+
+ policy->governor->store_setspeed(policy, freq);
+
+ return count;
+}
+
+static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
+{
+ if (!policy->governor || !policy->governor->show_setspeed)
+ return sprintf(buf, "<unsupported>\n");
+
+ return policy->governor->show_setspeed(policy, buf);
+}
+
+/**
+ * show_scaling_driver - show the current cpufreq HW/BIOS limitation
+ */
+static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
+{
+ unsigned int limit;
+ int ret;
+ if (cpufreq_driver->bios_limit) {
+ ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
+ if (!ret)
+ return sprintf(buf, "%u\n", limit);
+ }
+ return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
+}
+
+cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
+cpufreq_freq_attr_ro(cpuinfo_min_freq);
+cpufreq_freq_attr_ro(cpuinfo_max_freq);
+cpufreq_freq_attr_ro(cpuinfo_transition_latency);
+cpufreq_freq_attr_ro(scaling_available_governors);
+cpufreq_freq_attr_ro(scaling_driver);
+cpufreq_freq_attr_ro(scaling_cur_freq);
+cpufreq_freq_attr_ro(bios_limit);
+cpufreq_freq_attr_ro(related_cpus);
+cpufreq_freq_attr_ro(affected_cpus);
+cpufreq_freq_attr_rw(scaling_min_freq);
+cpufreq_freq_attr_rw(scaling_max_freq);
+cpufreq_freq_attr_rw(scaling_governor);
+cpufreq_freq_attr_rw(scaling_setspeed);
+
+static struct attribute *default_attrs[] = {
+ &cpuinfo_min_freq.attr,
+ &cpuinfo_max_freq.attr,
+ &cpuinfo_transition_latency.attr,
+ &scaling_min_freq.attr,
+ &scaling_max_freq.attr,
+ &affected_cpus.attr,
+ &related_cpus.attr,
+ &scaling_governor.attr,
+ &scaling_driver.attr,
+ &scaling_available_governors.attr,
+ &scaling_setspeed.attr,
+ NULL
+};
+
+struct kobject *cpufreq_global_kobject;
+EXPORT_SYMBOL(cpufreq_global_kobject);
+
+#define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
+#define to_attr(a) container_of(a, struct freq_attr, attr)
+
+static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
+{
+ struct cpufreq_policy *policy = to_policy(kobj);
+ struct freq_attr *fattr = to_attr(attr);
+ ssize_t ret = -EINVAL;
+ policy = cpufreq_cpu_get(policy->cpu);
+ if (!policy)
+ goto no_policy;
+
+ if (lock_policy_rwsem_read(policy->cpu) < 0)
+ goto fail;
+
+ if (fattr->show)
+ ret = fattr->show(policy, buf);
+ else
+ ret = -EIO;
+
+ unlock_policy_rwsem_read(policy->cpu);
+fail:
+ cpufreq_cpu_put(policy);
+no_policy:
+ return ret;
+}
+
+static ssize_t store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
+{
+ struct cpufreq_policy *policy = to_policy(kobj);
+ struct freq_attr *fattr = to_attr(attr);
+ ssize_t ret = -EINVAL;
+ policy = cpufreq_cpu_get(policy->cpu);
+ if (!policy)
+ goto no_policy;
+
+ if (lock_policy_rwsem_write(policy->cpu) < 0)
+ goto fail;
+
+ if (fattr->store)
+ ret = fattr->store(policy, buf, count);
+ else
+ ret = -EIO;
+
+ unlock_policy_rwsem_write(policy->cpu);
+fail:
+ cpufreq_cpu_put(policy);
+no_policy:
+ return ret;
+}
+
+static void cpufreq_sysfs_release(struct kobject *kobj)
+{
+ struct cpufreq_policy *policy = to_policy(kobj);
+ pr_debug("last reference is dropped\n");
+ complete(&policy->kobj_unregister);
+}
+
+static const struct sysfs_ops sysfs_ops = {
+ .show = show,
+ .store = store,
+};
+
+static struct kobj_type ktype_cpufreq = {
+ .sysfs_ops = &sysfs_ops,
+ .default_attrs = default_attrs,
+ .release = cpufreq_sysfs_release,
+};
+
+/*
+ * Returns:
+ * Negative: Failure
+ * 0: Success
+ * Positive: When we have a managed CPU and the sysfs got symlinked
+ */
+static int cpufreq_add_dev_policy(unsigned int cpu,
+ struct cpufreq_policy *policy,
+ struct device *dev)
+{
+ int ret = 0;
+#ifdef CONFIG_SMP
+ unsigned long flags;
+ unsigned int j;
+#ifdef CONFIG_HOTPLUG_CPU
+ struct cpufreq_governor *gov;
+
+ gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));
+ if (gov) {
+ policy->governor = gov;
+ pr_debug("Restoring governor %s for cpu %d\n",
+ policy->governor->name, cpu);
+ }
+#endif
+
+ for_each_cpu(j, policy->cpus) {
+ struct cpufreq_policy *managed_policy;
+
+ if (cpu == j)
+ continue;
+
+ /* Check for existing affected CPUs.
+ * They may not be aware of it due to CPU Hotplug.
+ * cpufreq_cpu_put is called when the device is removed
+ * in __cpufreq_remove_dev()
+ */
+ managed_policy = cpufreq_cpu_get(j);
+ if (unlikely(managed_policy)) {
+
+ /* Set proper policy_cpu */
+ unlock_policy_rwsem_write(cpu);
+ per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu;
+
+ if (lock_policy_rwsem_write(cpu) < 0) {
+ /* Should not go through policy unlock path */
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(policy);
+ cpufreq_cpu_put(managed_policy);
+ return -EBUSY;
+ }
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ cpumask_copy(managed_policy->cpus, policy->cpus);
+ per_cpu(cpufreq_cpu_data, cpu) = managed_policy;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ pr_debug("CPU already managed, adding link\n");
+ ret = sysfs_create_link(&dev->kobj,
+ &managed_policy->kobj,
+ "cpufreq");
+ if (ret)
+ cpufreq_cpu_put(managed_policy);
+ /*
+ * Success. We only needed to be added to the mask.
+ * Call driver->exit() because only the cpu parent of
+ * the kobj needed to call init().
+ */
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(policy);
+
+ if (!ret)
+ return 1;
+ else
+ return ret;
+ }
+ }
+#endif
+ return ret;
+}
+
+
+/* symlink affected CPUs */
+static int cpufreq_add_dev_symlink(unsigned int cpu,
+ struct cpufreq_policy *policy)
+{
+ unsigned int j;
+ int ret = 0;
+
+ for_each_cpu(j, policy->cpus) {
+ struct cpufreq_policy *managed_policy;
+ struct device *cpu_dev;
+
+ if (j == cpu)
+ continue;
+ if (!cpu_online(j))
+ continue;
+
+ pr_debug("CPU %u already managed, adding link\n", j);
+ managed_policy = cpufreq_cpu_get(cpu);
+ cpu_dev = get_cpu_device(j);
+ ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
+ "cpufreq");
+ if (ret) {
+ cpufreq_cpu_put(managed_policy);
+ return ret;
+ }
+ }
+ return ret;
+}
+
+static int cpufreq_add_dev_interface(unsigned int cpu,
+ struct cpufreq_policy *policy,
+ struct device *dev)
+{
+ struct cpufreq_policy new_policy;
+ struct freq_attr **drv_attr;
+ unsigned long flags;
+ int ret = 0;
+ unsigned int j;
+
+ /* prepare interface data */
+ ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
+ &dev->kobj, "cpufreq");
+ if (ret)
+ return ret;
+
+ /* set up files for this cpu device */
+ drv_attr = cpufreq_driver->attr;
+ while ((drv_attr) && (*drv_attr)) {
+ ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
+ if (ret)
+ goto err_out_kobj_put;
+ drv_attr++;
+ }
+ if (cpufreq_driver->get) {
+ ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
+ if (ret)
+ goto err_out_kobj_put;
+ }
+
+ ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
+ if (ret)
+ goto err_out_kobj_put;
+
+ if (cpufreq_driver->bios_limit) {
+ ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
+ if (ret)
+ goto err_out_kobj_put;
+ }
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ for_each_cpu(j, policy->cpus) {
+ if (!cpu_online(j))
+ continue;
+ per_cpu(cpufreq_cpu_data, j) = policy;
+ per_cpu(cpufreq_policy_cpu, j) = policy->cpu;
+ }
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ ret = cpufreq_add_dev_symlink(cpu, policy);
+ if (ret)
+ goto err_out_kobj_put;
+
+ memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
+ /* assure that the starting sequence is run in __cpufreq_set_policy */
+ policy->governor = NULL;
+
+ /* set default policy */
+ ret = __cpufreq_set_policy(policy, &new_policy);
+ policy->user_policy.policy = policy->policy;
+ policy->user_policy.governor = policy->governor;
+
+ if (ret) {
+ pr_debug("setting policy failed\n");
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(policy);
+ }
+ return ret;
+
+err_out_kobj_put:
+ kobject_put(&policy->kobj);
+ wait_for_completion(&policy->kobj_unregister);
+ return ret;
+}
+
+
+/**
+ * cpufreq_add_dev - add a CPU device
+ *
+ * Adds the cpufreq interface for a CPU device.
+ *
+ * The Oracle says: try running cpufreq registration/unregistration concurrently
+ * with with cpu hotplugging and all hell will break loose. Tried to clean this
+ * mess up, but more thorough testing is needed. - Mathieu
+ */
+static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
+{
+ unsigned int cpu = dev->id;
+ int ret = 0, found = 0;
+ struct cpufreq_policy *policy;
+ unsigned long flags;
+ unsigned int j;
+#ifdef CONFIG_HOTPLUG_CPU
+ int sibling;
+#endif
+
+ if (cpu_is_offline(cpu))
+ return 0;
+
+ pr_debug("adding CPU %u\n", cpu);
+
+#ifdef CONFIG_SMP
+ /* check whether a different CPU already registered this
+ * CPU because it is in the same boat. */
+ policy = cpufreq_cpu_get(cpu);
+ if (unlikely(policy)) {
+ cpufreq_cpu_put(policy);
+ return 0;
+ }
+#endif
+
+ if (!try_module_get(cpufreq_driver->owner)) {
+ ret = -EINVAL;
+ goto module_out;
+ }
+
+ ret = -ENOMEM;
+ policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
+ if (!policy)
+ goto nomem_out;
+
+ if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
+ goto err_free_policy;
+
+ if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
+ goto err_free_cpumask;
+
+ policy->cpu = cpu;
+ cpumask_copy(policy->cpus, cpumask_of(cpu));
+
+ /* Initially set CPU itself as the policy_cpu */
+ per_cpu(cpufreq_policy_cpu, cpu) = cpu;
+ ret = (lock_policy_rwsem_write(cpu) < 0);
+ WARN_ON(ret);
+
+ init_completion(&policy->kobj_unregister);
+ INIT_WORK(&policy->update, handle_update);
+
+ /* Set governor before ->init, so that driver could check it */
+#ifdef CONFIG_HOTPLUG_CPU
+ for_each_online_cpu(sibling) {
+ struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling);
+ if (cp && cp->governor &&
+ (cpumask_test_cpu(cpu, cp->related_cpus))) {
+ policy->governor = cp->governor;
+ found = 1;
+ break;
+ }
+ }
+#endif
+ if (!found)
+ policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+ /* call driver. From then on the cpufreq must be able
+ * to accept all calls to ->verify and ->setpolicy for this CPU
+ */
+ ret = cpufreq_driver->init(policy);
+ if (ret) {
+ pr_debug("initialization failed\n");
+ goto err_unlock_policy;
+ }
+ policy->user_policy.min = policy->min;
+ policy->user_policy.max = policy->max;
+
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_START, policy);
+
+ ret = cpufreq_add_dev_policy(cpu, policy, dev);
+ if (ret) {
+ if (ret > 0)
+ /* This is a managed cpu, symlink created,
+ exit with 0 */
+ ret = 0;
+ goto err_unlock_policy;
+ }
+
+ ret = cpufreq_add_dev_interface(cpu, policy, dev);
+ if (ret)
+ goto err_out_unregister;
+
+ unlock_policy_rwsem_write(cpu);
+
+ kobject_uevent(&policy->kobj, KOBJ_ADD);
+ module_put(cpufreq_driver->owner);
+ pr_debug("initialization complete\n");
+
+ return 0;
+
+
+err_out_unregister:
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ for_each_cpu(j, policy->cpus)
+ per_cpu(cpufreq_cpu_data, j) = NULL;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ kobject_put(&policy->kobj);
+ wait_for_completion(&policy->kobj_unregister);
+
+err_unlock_policy:
+ unlock_policy_rwsem_write(cpu);
+ free_cpumask_var(policy->related_cpus);
+err_free_cpumask:
+ free_cpumask_var(policy->cpus);
+err_free_policy:
+ kfree(policy);
+nomem_out:
+ module_put(cpufreq_driver->owner);
+module_out:
+ return ret;
+}
+
+
+/**
+ * __cpufreq_remove_dev - remove a CPU device
+ *
+ * Removes the cpufreq interface for a CPU device.
+ * Caller should already have policy_rwsem in write mode for this CPU.
+ * This routine frees the rwsem before returning.
+ */
+static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
+{
+ unsigned int cpu = dev->id;
+ unsigned long flags;
+ struct cpufreq_policy *data;
+ struct kobject *kobj;
+ struct completion *cmp;
+#ifdef CONFIG_SMP
+ struct device *cpu_dev;
+ unsigned int j;
+#endif
+
+ pr_debug("unregistering CPU %u\n", cpu);
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ data = per_cpu(cpufreq_cpu_data, cpu);
+
+ if (!data) {
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ unlock_policy_rwsem_write(cpu);
+ return -EINVAL;
+ }
+ per_cpu(cpufreq_cpu_data, cpu) = NULL;
+
+
+#ifdef CONFIG_SMP
+ /* if this isn't the CPU which is the parent of the kobj, we
+ * only need to unlink, put and exit
+ */
+ if (unlikely(cpu != data->cpu)) {
+ pr_debug("removing link\n");
+ cpumask_clear_cpu(cpu, data->cpus);
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ kobj = &dev->kobj;
+ cpufreq_cpu_put(data);
+ unlock_policy_rwsem_write(cpu);
+ sysfs_remove_link(kobj, "cpufreq");
+ return 0;
+ }
+#endif
+
+#ifdef CONFIG_SMP
+
+#ifdef CONFIG_HOTPLUG_CPU
+ strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name,
+ CPUFREQ_NAME_LEN);
+#endif
+
+ /* if we have other CPUs still registered, we need to unlink them,
+ * or else wait_for_completion below will lock up. Clean the
+ * per_cpu(cpufreq_cpu_data) while holding the lock, and remove
+ * the sysfs links afterwards.
+ */
+ if (unlikely(cpumask_weight(data->cpus) > 1)) {
+ for_each_cpu(j, data->cpus) {
+ if (j == cpu)
+ continue;
+ per_cpu(cpufreq_cpu_data, j) = NULL;
+ }
+ }
+
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ if (unlikely(cpumask_weight(data->cpus) > 1)) {
+ for_each_cpu(j, data->cpus) {
+ if (j == cpu)
+ continue;
+ pr_debug("removing link for cpu %u\n", j);
+#ifdef CONFIG_HOTPLUG_CPU
+ strncpy(per_cpu(cpufreq_cpu_governor, j),
+ data->governor->name, CPUFREQ_NAME_LEN);
+#endif
+ cpu_dev = get_cpu_device(j);
+ kobj = &cpu_dev->kobj;
+ unlock_policy_rwsem_write(cpu);
+ sysfs_remove_link(kobj, "cpufreq");
+ lock_policy_rwsem_write(cpu);
+ cpufreq_cpu_put(data);
+ }
+ }
+#else
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+#endif
+
+ if (cpufreq_driver->target)
+ __cpufreq_governor(data, CPUFREQ_GOV_STOP);
+
+ kobj = &data->kobj;
+ cmp = &data->kobj_unregister;
+ unlock_policy_rwsem_write(cpu);
+ kobject_put(kobj);
+
+ /* we need to make sure that the underlying kobj is actually
+ * not referenced anymore by anybody before we proceed with
+ * unloading.
+ */
+ pr_debug("waiting for dropping of refcount\n");
+ wait_for_completion(cmp);
+ pr_debug("wait complete\n");
+
+ lock_policy_rwsem_write(cpu);
+ if (cpufreq_driver->exit)
+ cpufreq_driver->exit(data);
+ unlock_policy_rwsem_write(cpu);
+
+#ifdef CONFIG_HOTPLUG_CPU
+ /* when the CPU which is the parent of the kobj is hotplugged
+ * offline, check for siblings, and create cpufreq sysfs interface
+ * and symlinks
+ */
+ if (unlikely(cpumask_weight(data->cpus) > 1)) {
+ /* first sibling now owns the new sysfs dir */
+ cpumask_clear_cpu(cpu, data->cpus);
+ cpufreq_add_dev(get_cpu_device(cpumask_first(data->cpus)), NULL);
+
+ /* finally remove our own symlink */
+ lock_policy_rwsem_write(cpu);
+ __cpufreq_remove_dev(dev, sif);
+ }
+#endif
+
+ free_cpumask_var(data->related_cpus);
+ free_cpumask_var(data->cpus);
+ kfree(data);
+
+ return 0;
+}
+
+
+static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
+{
+ unsigned int cpu = dev->id;
+ int retval;
+
+ if (cpu_is_offline(cpu))
+ return 0;
+
+ if (unlikely(lock_policy_rwsem_write(cpu)))
+ BUG();
+
+ retval = __cpufreq_remove_dev(dev, sif);
+ return retval;
+}
+
+
+static void handle_update(struct work_struct *work)
+{
+ struct cpufreq_policy *policy =
+ container_of(work, struct cpufreq_policy, update);
+ unsigned int cpu = policy->cpu;
+ pr_debug("handle_update for cpu %u called\n", cpu);
+ cpufreq_update_policy(cpu);
+}
+
+/**
+ * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble.
+ * @cpu: cpu number
+ * @old_freq: CPU frequency the kernel thinks the CPU runs at
+ * @new_freq: CPU frequency the CPU actually runs at
+ *
+ * We adjust to current frequency first, and need to clean up later.
+ * So either call to cpufreq_update_policy() or schedule handle_update()).
+ */
+static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq,
+ unsigned int new_freq)
+{
+ struct cpufreq_freqs freqs;
+
+ pr_debug("Warning: CPU frequency out of sync: cpufreq and timing "
+ "core thinks of %u, is %u kHz.\n", old_freq, new_freq);
+
+ freqs.cpu = cpu;
+ freqs.old = old_freq;
+ freqs.new = new_freq;
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+}
+
+
+/**
+ * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
+ * @cpu: CPU number
+ *
+ * This is the last known freq, without actually getting it from the driver.
+ * Return value will be same as what is shown in scaling_cur_freq in sysfs.
+ */
+unsigned int cpufreq_quick_get(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+ unsigned int ret_freq = 0;
+
+ if (policy) {
+ ret_freq = policy->cur;
+ cpufreq_cpu_put(policy);
+ }
+
+ return ret_freq;
+}
+EXPORT_SYMBOL(cpufreq_quick_get);
+
+/**
+ * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
+ * @cpu: CPU number
+ *
+ * Just return the max possible frequency for a given CPU.
+ */
+unsigned int cpufreq_quick_get_max(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+ unsigned int ret_freq = 0;
+
+ if (policy) {
+ ret_freq = policy->max;
+ cpufreq_cpu_put(policy);
+ }
+
+ return ret_freq;
+}
+EXPORT_SYMBOL(cpufreq_quick_get_max);
+
+
+static unsigned int __cpufreq_get(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
+ unsigned int ret_freq = 0;
+
+ if (!cpufreq_driver->get)
+ return ret_freq;
+
+ ret_freq = cpufreq_driver->get(cpu);
+
+ if (ret_freq && policy->cur &&
+ !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
+ /* verify no discrepancy between actual and
+ saved value exists */
+ if (unlikely(ret_freq != policy->cur)) {
+ cpufreq_out_of_sync(cpu, policy->cur, ret_freq);
+ schedule_work(&policy->update);
+ }
+ }
+
+ return ret_freq;
+}
+
+/**
+ * cpufreq_get - get the current CPU frequency (in kHz)
+ * @cpu: CPU number
+ *
+ * Get the CPU current (static) CPU frequency
+ */
+unsigned int cpufreq_get(unsigned int cpu)
+{
+ unsigned int ret_freq = 0;
+ struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+
+ if (!policy)
+ goto out;
+
+ if (unlikely(lock_policy_rwsem_read(cpu)))
+ goto out_policy;
+
+ ret_freq = __cpufreq_get(cpu);
+
+ unlock_policy_rwsem_read(cpu);
+
+out_policy:
+ cpufreq_cpu_put(policy);
+out:
+ return ret_freq;
+}
+EXPORT_SYMBOL(cpufreq_get);
+
+static struct subsys_interface cpufreq_interface = {
+ .name = "cpufreq",
+ .subsys = &cpu_subsys,
+ .add_dev = cpufreq_add_dev,
+ .remove_dev = cpufreq_remove_dev,
+};
+
+
+/**
+ * cpufreq_bp_suspend - Prepare the boot CPU for system suspend.
+ *
+ * This function is only executed for the boot processor. The other CPUs
+ * have been put offline by means of CPU hotplug.
+ */
+static int cpufreq_bp_suspend(void)
+{
+ int ret = 0;
+
+ int cpu = smp_processor_id();
+ struct cpufreq_policy *cpu_policy;
+
+ pr_debug("suspending cpu %u\n", cpu);
+
+ /* If there's no policy for the boot CPU, we have nothing to do. */
+ cpu_policy = cpufreq_cpu_get(cpu);
+ if (!cpu_policy)
+ return 0;
+
+ if (cpufreq_driver->suspend) {
+ ret = cpufreq_driver->suspend(cpu_policy);
+ if (ret)
+ printk(KERN_ERR "cpufreq: suspend failed in ->suspend "
+ "step on CPU %u\n", cpu_policy->cpu);
+ }
+
+ cpufreq_cpu_put(cpu_policy);
+ return ret;
+}
+
+/**
+ * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU.
+ *
+ * 1.) resume CPUfreq hardware support (cpufreq_driver->resume())
+ * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are
+ * restored. It will verify that the current freq is in sync with
+ * what we believe it to be. This is a bit later than when it
+ * should be, but nonethteless it's better than calling
+ * cpufreq_driver->get() here which might re-enable interrupts...
+ *
+ * This function is only executed for the boot CPU. The other CPUs have not
+ * been turned on yet.
+ */
+static void cpufreq_bp_resume(void)
+{
+ int ret = 0;
+
+ int cpu = smp_processor_id();
+ struct cpufreq_policy *cpu_policy;
+
+ pr_debug("resuming cpu %u\n", cpu);
+
+ /* If there's no policy for the boot CPU, we have nothing to do. */
+ cpu_policy = cpufreq_cpu_get(cpu);
+ if (!cpu_policy)
+ return;
+
+ if (cpufreq_driver->resume) {
+ ret = cpufreq_driver->resume(cpu_policy);
+ if (ret) {
+ printk(KERN_ERR "cpufreq: resume failed in ->resume "
+ "step on CPU %u\n", cpu_policy->cpu);
+ goto fail;
+ }
+ }
+
+ schedule_work(&cpu_policy->update);
+
+fail:
+ cpufreq_cpu_put(cpu_policy);
+}
+
+static struct syscore_ops cpufreq_syscore_ops = {
+ .suspend = cpufreq_bp_suspend,
+ .resume = cpufreq_bp_resume,
+};
+
+
+/*********************************************************************
+ * NOTIFIER LISTS INTERFACE *
+ *********************************************************************/
+
+/**
+ * cpufreq_register_notifier - register a driver with cpufreq
+ * @nb: notifier function to register
+ * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
+ *
+ * Add a driver to one of two lists: either a list of drivers that
+ * are notified about clock rate changes (once before and once after
+ * the transition), or a list of drivers that are notified about
+ * changes in cpufreq policy.
+ *
+ * This function may sleep, and has the same return conditions as
+ * blocking_notifier_chain_register.
+ */
+int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
+{
+ int ret;
+
+ WARN_ON(!init_cpufreq_transition_notifier_list_called);
+
+ switch (list) {
+ case CPUFREQ_TRANSITION_NOTIFIER:
+ ret = srcu_notifier_chain_register(
+ &cpufreq_transition_notifier_list, nb);
+ break;
+ case CPUFREQ_POLICY_NOTIFIER:
+ ret = blocking_notifier_chain_register(
+ &cpufreq_policy_notifier_list, nb);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(cpufreq_register_notifier);
+
+
+/**
+ * cpufreq_unregister_notifier - unregister a driver with cpufreq
+ * @nb: notifier block to be unregistered
+ * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
+ *
+ * Remove a driver from the CPU frequency notifier list.
+ *
+ * This function may sleep, and has the same return conditions as
+ * blocking_notifier_chain_unregister.
+ */
+int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
+{
+ int ret;
+
+ switch (list) {
+ case CPUFREQ_TRANSITION_NOTIFIER:
+ ret = srcu_notifier_chain_unregister(
+ &cpufreq_transition_notifier_list, nb);
+ break;
+ case CPUFREQ_POLICY_NOTIFIER:
+ ret = blocking_notifier_chain_unregister(
+ &cpufreq_policy_notifier_list, nb);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(cpufreq_unregister_notifier);
+
+
+/*********************************************************************
+ * GOVERNORS *
+ *********************************************************************/
+
+
+int __cpufreq_driver_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ int retval = -EINVAL;
+
+ if (cpufreq_disabled())
+ return -ENODEV;
+
+ pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
+ target_freq, relation);
+ if (cpu_online(policy->cpu) && cpufreq_driver->target)
+ retval = cpufreq_driver->target(policy, target_freq, relation);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
+
+int cpufreq_driver_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ int ret = -EINVAL;
+
+ policy = cpufreq_cpu_get(policy->cpu);
+ if (!policy)
+ goto no_policy;
+
+ if (unlikely(lock_policy_rwsem_write(policy->cpu)))
+ goto fail;
+
+ ret = __cpufreq_driver_target(policy, target_freq, relation);
+
+ unlock_policy_rwsem_write(policy->cpu);
+
+fail:
+ cpufreq_cpu_put(policy);
+no_policy:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpufreq_driver_target);
+
+int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu)
+{
+ int ret = 0;
+
+ policy = cpufreq_cpu_get(policy->cpu);
+ if (!policy)
+ return -EINVAL;
+
+ if (cpu_online(cpu) && cpufreq_driver->getavg)
+ ret = cpufreq_driver->getavg(policy, cpu);
+
+ cpufreq_cpu_put(policy);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg);
+
+/*
+ * when "event" is CPUFREQ_GOV_LIMITS
+ */
+
+static int __cpufreq_governor(struct cpufreq_policy *policy,
+ unsigned int event)
+{
+ int ret;
+
+ /* Only must be defined when default governor is known to have latency
+ restrictions, like e.g. conservative or ondemand.
+ That this is the case is already ensured in Kconfig
+ */
+#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
+ struct cpufreq_governor *gov = &cpufreq_gov_performance;
+#else
+ struct cpufreq_governor *gov = NULL;
+#endif
+
+ if (policy->governor->max_transition_latency &&
+ policy->cpuinfo.transition_latency >
+ policy->governor->max_transition_latency) {
+ if (!gov)
+ return -EINVAL;
+ else {
+ printk(KERN_WARNING "%s governor failed, too long"
+ " transition latency of HW, fallback"
+ " to %s governor\n",
+ policy->governor->name,
+ gov->name);
+ policy->governor = gov;
+ }
+ }
+
+ if (!try_module_get(policy->governor->owner))
+ return -EINVAL;
+
+ pr_debug("__cpufreq_governor for CPU %u, event %u\n",
+ policy->cpu, event);
+ ret = policy->governor->governor(policy, event);
+
+ /* we keep one module reference alive for
+ each CPU governed by this CPU */
+ if ((event != CPUFREQ_GOV_START) || ret)
+ module_put(policy->governor->owner);
+ if ((event == CPUFREQ_GOV_STOP) && !ret)
+ module_put(policy->governor->owner);
+
+ return ret;
+}
+
+
+int cpufreq_register_governor(struct cpufreq_governor *governor)
+{
+ int err;
+
+ if (!governor)
+ return -EINVAL;
+
+ if (cpufreq_disabled())
+ return -ENODEV;
+
+ mutex_lock(&cpufreq_governor_mutex);
+
+ err = -EBUSY;
+ if (__find_governor(governor->name) == NULL) {
+ err = 0;
+ list_add(&governor->governor_list, &cpufreq_governor_list);
+ }
+
+ mutex_unlock(&cpufreq_governor_mutex);
+ return err;
+}
+EXPORT_SYMBOL_GPL(cpufreq_register_governor);
+
+
+void cpufreq_unregister_governor(struct cpufreq_governor *governor)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+ int cpu;
+#endif
+
+ if (!governor)
+ return;
+
+ if (cpufreq_disabled())
+ return;
+
+#ifdef CONFIG_HOTPLUG_CPU
+ for_each_present_cpu(cpu) {
+ if (cpu_online(cpu))
+ continue;
+ if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name))
+ strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0");
+ }
+#endif
+
+ mutex_lock(&cpufreq_governor_mutex);
+ list_del(&governor->governor_list);
+ mutex_unlock(&cpufreq_governor_mutex);
+ return;
+}
+EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
+
+
+
+/*********************************************************************
+ * POLICY INTERFACE *
+ *********************************************************************/
+
+/**
+ * cpufreq_get_policy - get the current cpufreq_policy
+ * @policy: struct cpufreq_policy into which the current cpufreq_policy
+ * is written
+ *
+ * Reads the current cpufreq policy.
+ */
+int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
+{
+ struct cpufreq_policy *cpu_policy;
+ if (!policy)
+ return -EINVAL;
+
+ cpu_policy = cpufreq_cpu_get(cpu);
+ if (!cpu_policy)
+ return -EINVAL;
+
+ memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy));
+
+ cpufreq_cpu_put(cpu_policy);
+ return 0;
+}
+EXPORT_SYMBOL(cpufreq_get_policy);
+
+
+/*
+ * data : current policy.
+ * policy : policy to be set.
+ */
+static int __cpufreq_set_policy(struct cpufreq_policy *data,
+ struct cpufreq_policy *policy)
+{
+ int ret = 0;
+
+ pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu,
+ policy->min, policy->max);
+
+ memcpy(&policy->cpuinfo, &data->cpuinfo,
+ sizeof(struct cpufreq_cpuinfo));
+
+ if (policy->min > data->max || policy->max < data->min) {
+ ret = -EINVAL;
+ goto error_out;
+ }
+
+ /* verify the cpu speed can be set within this limit */
+ ret = cpufreq_driver->verify(policy);
+ if (ret)
+ goto error_out;
+
+ /* adjust if necessary - all reasons */
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_ADJUST, policy);
+
+ /* adjust if necessary - hardware incompatibility*/
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_INCOMPATIBLE, policy);
+
+ /* verify the cpu speed can be set within this limit,
+ which might be different to the first one */
+ ret = cpufreq_driver->verify(policy);
+ if (ret)
+ goto error_out;
+
+ /* notification of the new policy */
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_NOTIFY, policy);
+
+ data->min = policy->min;
+ data->max = policy->max;
+
+ pr_debug("new min and max freqs are %u - %u kHz\n",
+ data->min, data->max);
+
+ if (cpufreq_driver->setpolicy) {
+ data->policy = policy->policy;
+ pr_debug("setting range\n");
+ ret = cpufreq_driver->setpolicy(policy);
+ } else {
+ if (policy->governor != data->governor) {
+ /* save old, working values */
+ struct cpufreq_governor *old_gov = data->governor;
+
+ pr_debug("governor switch\n");
+
+ /* end old governor */
+ if (data->governor)
+ __cpufreq_governor(data, CPUFREQ_GOV_STOP);
+
+ /* start new governor */
+ data->governor = policy->governor;
+ if (__cpufreq_governor(data, CPUFREQ_GOV_START)) {
+ /* new governor failed, so re-start old one */
+ pr_debug("starting governor %s failed\n",
+ data->governor->name);
+ if (old_gov) {
+ data->governor = old_gov;
+ __cpufreq_governor(data,
+ CPUFREQ_GOV_START);
+ }
+ ret = -EINVAL;
+ goto error_out;
+ }
+ /* might be a policy change, too, so fall through */
+ }
+ pr_debug("governor: change or update limits\n");
+ __cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
+ }
+
+error_out:
+ return ret;
+}
+
+/**
+ * cpufreq_update_policy - re-evaluate an existing cpufreq policy
+ * @cpu: CPU which shall be re-evaluated
+ *
+ * Useful for policy notifiers which have different necessities
+ * at different times.
+ */
+int cpufreq_update_policy(unsigned int cpu)
+{
+ struct cpufreq_policy *data = cpufreq_cpu_get(cpu);
+ struct cpufreq_policy policy;
+ int ret;
+
+ if (!data) {
+ ret = -ENODEV;
+ goto no_policy;
+ }
+
+ if (unlikely(lock_policy_rwsem_write(cpu))) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ pr_debug("updating policy for CPU %u\n", cpu);
+ memcpy(&policy, data, sizeof(struct cpufreq_policy));
+ policy.min = data->user_policy.min;
+ policy.max = data->user_policy.max;
+ policy.policy = data->user_policy.policy;
+ policy.governor = data->user_policy.governor;
+
+ /* BIOS might change freq behind our back
+ -> ask driver for current freq and notify governors about a change */
+ if (cpufreq_driver->get) {
+ policy.cur = cpufreq_driver->get(cpu);
+ if (!data->cur) {
+ pr_debug("Driver did not initialize current freq");
+ data->cur = policy.cur;
+ } else {
+ if (data->cur != policy.cur)
+ cpufreq_out_of_sync(cpu, data->cur,
+ policy.cur);
+ }
+ }
+
+ ret = __cpufreq_set_policy(data, &policy);
+
+ unlock_policy_rwsem_write(cpu);
+
+fail:
+ cpufreq_cpu_put(data);
+no_policy:
+ return ret;
+}
+EXPORT_SYMBOL(cpufreq_update_policy);
+
+static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+ struct device *dev;
+
+ dev = get_cpu_device(cpu);
+ if (dev) {
+ switch (action) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ cpufreq_add_dev(dev, NULL);
+ break;
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ if (unlikely(lock_policy_rwsem_write(cpu)))
+ BUG();
+
+ __cpufreq_remove_dev(dev, NULL);
+ break;
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
+ cpufreq_add_dev(dev, NULL);
+ break;
+ }
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __refdata cpufreq_cpu_notifier = {
+ .notifier_call = cpufreq_cpu_callback,
+};
+
+/*********************************************************************
+ * REGISTER / UNREGISTER CPUFREQ DRIVER *
+ *********************************************************************/
+
+/**
+ * cpufreq_register_driver - register a CPU Frequency driver
+ * @driver_data: A struct cpufreq_driver containing the values#
+ * submitted by the CPU Frequency driver.
+ *
+ * Registers a CPU Frequency driver to this core code. This code
+ * returns zero on success, -EBUSY when another driver got here first
+ * (and isn't unregistered in the meantime).
+ *
+ */
+int cpufreq_register_driver(struct cpufreq_driver *driver_data)
+{
+ unsigned long flags;
+ int ret;
+
+ if (cpufreq_disabled())
+ return -ENODEV;
+
+ if (!driver_data || !driver_data->verify || !driver_data->init ||
+ ((!driver_data->setpolicy) && (!driver_data->target)))
+ return -EINVAL;
+
+ pr_debug("trying to register driver %s\n", driver_data->name);
+
+ if (driver_data->setpolicy)
+ driver_data->flags |= CPUFREQ_CONST_LOOPS;
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ if (cpufreq_driver) {
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ return -EBUSY;
+ }
+ cpufreq_driver = driver_data;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ ret = subsys_interface_register(&cpufreq_interface);
+ if (ret)
+ goto err_null_driver;
+
+ if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) {
+ int i;
+ ret = -ENODEV;
+
+ /* check for at least one working CPU */
+ for (i = 0; i < nr_cpu_ids; i++)
+ if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) {
+ ret = 0;
+ break;
+ }
+
+ /* if all ->init() calls failed, unregister */
+ if (ret) {
+ pr_debug("no CPU initialized for driver %s\n",
+ driver_data->name);
+ goto err_if_unreg;
+ }
+ }
+
+ register_hotcpu_notifier(&cpufreq_cpu_notifier);
+ pr_debug("driver %s up and running\n", driver_data->name);
+
+ return 0;
+err_if_unreg:
+ subsys_interface_unregister(&cpufreq_interface);
+err_null_driver:
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ cpufreq_driver = NULL;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpufreq_register_driver);
+
+
+/**
+ * cpufreq_unregister_driver - unregister the current CPUFreq driver
+ *
+ * Unregister the current CPUFreq driver. Only call this if you have
+ * the right to do so, i.e. if you have succeeded in initialising before!
+ * Returns zero if successful, and -EINVAL if the cpufreq_driver is
+ * currently not initialised.
+ */
+int cpufreq_unregister_driver(struct cpufreq_driver *driver)
+{
+ unsigned long flags;
+
+ if (!cpufreq_driver || (driver != cpufreq_driver))
+ return -EINVAL;
+
+ pr_debug("unregistering driver %s\n", driver->name);
+
+ subsys_interface_unregister(&cpufreq_interface);
+ unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
+
+ spin_lock_irqsave(&cpufreq_driver_lock, flags);
+ cpufreq_driver = NULL;
+ spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
+
+static int __init cpufreq_core_init(void)
+{
+ int cpu;
+
+ if (cpufreq_disabled())
+ return -ENODEV;
+
+ for_each_possible_cpu(cpu) {
+ per_cpu(cpufreq_policy_cpu, cpu) = -1;
+ init_rwsem(&per_cpu(cpu_policy_rwsem, cpu));
+ }
+
+ cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
+ BUG_ON(!cpufreq_global_kobject);
+ register_syscore_ops(&cpufreq_syscore_ops);
+
+ return 0;
+}
+core_initcall(cpufreq_core_init);