Initial import

1 files changed, 2549 insertions, 0 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
new file mode 100644
index 000000000..d99bdf166
--- /dev/null
+++ b/drivers/cpufreq/cpufreq.c
@@ -0,0 +1,2549 @@
+/*
+ *  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/sched.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;
+}
+
+/*
+ * rwsem to guarantee that cpufreq driver module doesn't unload during critical
+ * sections
+ */
+static DECLARE_RWSEM(cpufreq_rwsem);
+
+/* 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;
+
+	if (!down_read_trylock(&cpufreq_rwsem))
+		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);
+
+	if (!policy)
+		up_read(&cpufreq_rwsem);
+
+	return policy;
+}
+EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
+
+void cpufreq_cpu_put(struct cpufreq_policy *policy)
+{
+	kobject_put(&policy->kobj);
+	up_read(&cpufreq_rwsem);
+}
+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;
+
+	if (!down_read_trylock(&cpufreq_rwsem))
+		return -EINVAL;
+
+	down_read(&policy->rwsem);
+
+	if (fattr->show)
+		ret = fattr->show(policy, buf);
+	else
+		ret = -EIO;
+
+	up_read(&policy->rwsem);
+	up_read(&cpufreq_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;
+
+	if (!down_read_trylock(&cpufreq_rwsem))
+		goto unlock;
+
+	down_write(&policy->rwsem);
+
+	if (fattr->store)
+		ret = fattr->store(policy, buf, count);
+	else
+		ret = -EIO;
+
+	up_write(&policy->rwsem);
+
+	up_read(&cpufreq_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;
+
+	if (!down_read_trylock(&cpufreq_rwsem))
+		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);
+			up_read(&cpufreq_rwsem);
+			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);
+
+	up_read(&cpufreq_rwsem);
+
+	/* 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:
+	up_read(&cpufreq_rwsem);
+
+	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:
+#ifdef CONFIG_SCHED_BFS
+	if (likely(retval != -EINVAL)) {
+		if (target_freq == policy->max)
+			cpu_nonscaling(policy->cpu);
+		else
+			cpu_scaling(policy->cpu);
+	}
+#endif
+	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);
+
+	subsys_interface_unregister(&cpufreq_interface);
+	if (cpufreq_boost_supported())
+		cpufreq_sysfs_remove_file(&boost.attr);
+
+	unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
+
+	down_write(&cpufreq_rwsem);
+	write_lock_irqsave(&cpufreq_driver_lock, flags);
+
+	cpufreq_driver = NULL;
+
+	write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+	up_write(&cpufreq_rwsem);
+
+	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);