Merge branch 'pm-cpufreq'

* pm-cpufreq: (55 commits)
  cpufreq / intel_pstate: Fix 32 bit build
  cpufreq: conservative: Fix typos in comments
  cpufreq: ondemand: Fix typos in comments
  cpufreq: exynos: simplify .init() for setting policy->cpus
  cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs
  cpufreq/x86: Add P-state driver for sandy bridge.
  cpufreq_stats: do not remove sysfs files if frequency table is not present
  cpufreq: Do not track governor name for scaling drivers with internal governors.
  cpufreq: Only call cpufreq_out_of_sync() for driver that implement cpufreq_driver.target()
  cpufreq: Retrieve current frequency from scaling drivers with internal governors
  cpufreq: Fix locking issues
  cpufreq: Create a macro for unlock_policy_rwsem{read,write}
  cpufreq: Remove unused HOTPLUG_CPU code
  cpufreq: governors: Fix WARN_ON() for multi-policy platforms
  cpufreq: ondemand: Replace down_differential tuner with adj_up_threshold
  cpufreq / stats: Get rid of CPUFREQ_STATDEVICE_ATTR
  cpufreq: Don't check cpu_online(policy->cpu)
  cpufreq: add imx6q-cpufreq driver
  cpufreq: Don't remove sysfs link for policy->cpu
  cpufreq: Remove unnecessary use of policy->shared_type
  ...

1 files changed, 807 insertions, 0 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
new file mode 100644
index 000000000000..e87996355da0
--- /dev/null
+++ b/drivers/cpufreq/intel_pstate.c
@@ -0,0 +1,807 @@
+/*
+ * cpufreq_snb.c: Native P state management for Intel processors
+ *
+ * (C) Copyright 2012 Intel Corporation
+ * Author: Dirk Brandewie <dirk.j.brandewie@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kernel_stat.h>
+#include <linux/module.h>
+#include <linux/ktime.h>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <trace/events/power.h>
+
+#include <asm/div64.h>
+#include <asm/msr.h>
+#include <asm/cpu_device_id.h>
+
+#define SAMPLE_COUNT            3
+
+#define FRAC_BITS 8
+#define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
+#define fp_toint(X) ((X) >> FRAC_BITS)
+
+static inline int32_t mul_fp(int32_t x, int32_t y)
+{
+        return ((int64_t)x * (int64_t)y) >> FRAC_BITS;
+}
+
+static inline int32_t div_fp(int32_t x, int32_t y)
+{
+        return div_s64((int64_t)x << FRAC_BITS, (int64_t)y);
+}
+
+struct sample {
+        ktime_t start_time;
+        ktime_t end_time;
+        int core_pct_busy;
+        int pstate_pct_busy;
+        u64 duration_us;
+        u64 idletime_us;
+        u64 aperf;
+        u64 mperf;
+        int freq;
+};
+
+struct pstate_data {
+        int     current_pstate;
+        int     min_pstate;
+        int     max_pstate;
+        int     turbo_pstate;
+};
+
+struct _pid {
+        int setpoint;
+        int32_t integral;
+        int32_t p_gain;
+        int32_t i_gain;
+        int32_t d_gain;
+        int deadband;
+        int last_err;
+};
+
+struct cpudata {
+        int cpu;
+
+        char name[64];
+
+        struct timer_list timer;
+
+        struct pstate_adjust_policy *pstate_policy;
+        struct pstate_data pstate;
+        struct _pid pid;
+        struct _pid idle_pid;
+
+        int min_pstate_count;
+        int idle_mode;
+
+        ktime_t prev_sample;
+        u64     prev_idle_time_us;
+        u64     prev_aperf;
+        u64     prev_mperf;
+        int     sample_ptr;
+        struct sample samples[SAMPLE_COUNT];
+};
+
+static struct cpudata **all_cpu_data;
+struct pstate_adjust_policy {
+        int sample_rate_ms;
+        int deadband;
+        int setpoint;
+        int p_gain_pct;
+        int d_gain_pct;
+        int i_gain_pct;
+};
+
+static struct pstate_adjust_policy default_policy = {
+        .sample_rate_ms = 10,
+        .deadband = 0,
+        .setpoint = 109,
+        .p_gain_pct = 17,
+        .d_gain_pct = 0,
+        .i_gain_pct = 4,
+};
+
+struct perf_limits {
+        int no_turbo;
+        int max_perf_pct;
+        int min_perf_pct;
+        int32_t max_perf;
+        int32_t min_perf;
+};
+
+static struct perf_limits limits = {
+        .no_turbo = 0,
+        .max_perf_pct = 100,
+        .max_perf = int_tofp(1),
+        .min_perf_pct = 0,
+        .min_perf = 0,
+};
+
+static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
+                        int deadband, int integral) {
+        pid->setpoint = setpoint;
+        pid->deadband  = deadband;
+        pid->integral  = int_tofp(integral);
+        pid->last_err  = setpoint - busy;
+}
+
+static inline void pid_p_gain_set(struct _pid *pid, int percent)
+{
+        pid->p_gain = div_fp(int_tofp(percent), int_tofp(100));
+}
+
+static inline void pid_i_gain_set(struct _pid *pid, int percent)
+{
+        pid->i_gain = div_fp(int_tofp(percent), int_tofp(100));
+}
+
+static inline void pid_d_gain_set(struct _pid *pid, int percent)
+{
+
+        pid->d_gain = div_fp(int_tofp(percent), int_tofp(100));
+}
+
+static signed int pid_calc(struct _pid *pid, int busy)
+{
+        signed int err, result;
+        int32_t pterm, dterm, fp_error;
+        int32_t integral_limit;
+
+        err = pid->setpoint - busy;
+        fp_error = int_tofp(err);
+
+        if (abs(err) <= pid->deadband)
+                return 0;
+
+        pterm = mul_fp(pid->p_gain, fp_error);
+
+        pid->integral += fp_error;
+
+        /* limit the integral term */
+        integral_limit = int_tofp(30);
+        if (pid->integral > integral_limit)
+                pid->integral = integral_limit;
+        if (pid->integral < -integral_limit)
+                pid->integral = -integral_limit;
+
+        dterm = mul_fp(pid->d_gain, (err - pid->last_err));
+        pid->last_err = err;
+
+        result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
+
+        return (signed int)fp_toint(result);
+}
+
+static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
+{
+        pid_p_gain_set(&cpu->pid, cpu->pstate_policy->p_gain_pct);
+        pid_d_gain_set(&cpu->pid, cpu->pstate_policy->d_gain_pct);
+        pid_i_gain_set(&cpu->pid, cpu->pstate_policy->i_gain_pct);
+
+        pid_reset(&cpu->pid,
+                cpu->pstate_policy->setpoint,
+                100,
+                cpu->pstate_policy->deadband,
+                0);
+}
+
+static inline void intel_pstate_idle_pid_reset(struct cpudata *cpu)
+{
+        pid_p_gain_set(&cpu->idle_pid, cpu->pstate_policy->p_gain_pct);
+        pid_d_gain_set(&cpu->idle_pid, cpu->pstate_policy->d_gain_pct);
+        pid_i_gain_set(&cpu->idle_pid, cpu->pstate_policy->i_gain_pct);
+
+        pid_reset(&cpu->idle_pid,
+                75,
+                50,
+                cpu->pstate_policy->deadband,
+                0);
+}
+
+static inline void intel_pstate_reset_all_pid(void)
+{
+        unsigned int cpu;
+        for_each_online_cpu(cpu) {
+                if (all_cpu_data[cpu])
+                        intel_pstate_busy_pid_reset(all_cpu_data[cpu]);
+        }
+}
+
+/************************** debugfs begin ************************/
+static int pid_param_set(void *data, u64 val)
+{
+        *(u32 *)data = val;
+        intel_pstate_reset_all_pid();
+        return 0;
+}
+static int pid_param_get(void *data, u64 *val)
+{
+        *val = *(u32 *)data;
+        return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_pid_param, pid_param_get,
+                        pid_param_set, "%llu\n");
+
+struct pid_param {
+        char *name;
+        void *value;
+};
+
+static struct pid_param pid_files[] = {
+        {"sample_rate_ms", &default_policy.sample_rate_ms},
+        {"d_gain_pct", &default_policy.d_gain_pct},
+        {"i_gain_pct", &default_policy.i_gain_pct},
+        {"deadband", &default_policy.deadband},
+        {"setpoint", &default_policy.setpoint},
+        {"p_gain_pct", &default_policy.p_gain_pct},
+        {NULL, NULL}
+};
+
+static struct dentry *debugfs_parent;
+static void intel_pstate_debug_expose_params(void)
+{
+        int i = 0;
+
+        debugfs_parent = debugfs_create_dir("pstate_snb", NULL);
+        if (IS_ERR_OR_NULL(debugfs_parent))
+                return;
+        while (pid_files[i].name) {
+                debugfs_create_file(pid_files[i].name, 0660,
+                                debugfs_parent, pid_files[i].value,
+                                &fops_pid_param);
+                i++;
+        }
+}
+
+/************************** debugfs end ************************/
+
+/************************** sysfs begin ************************/
+#define show_one(file_name, object)                                     \
+        static ssize_t show_##file_name                                 \
+        (struct kobject *kobj, struct attribute *attr, char *buf)       \
+        {                                                               \
+                return sprintf(buf, "%u\n", limits.object);             \
+        }
+
+static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
+                                const char *buf, size_t count)
+{
+        unsigned int input;
+        int ret;
+        ret = sscanf(buf, "%u", &input);
+        if (ret != 1)
+                return -EINVAL;
+        limits.no_turbo = clamp_t(int, input, 0 , 1);
+
+        return count;
+}
+
+static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
+                                const char *buf, size_t count)
+{
+        unsigned int input;
+        int ret;
+        ret = sscanf(buf, "%u", &input);
+        if (ret != 1)
+                return -EINVAL;
+
+        limits.max_perf_pct = clamp_t(int, input, 0 , 100);
+        limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
+        return count;
+}
+
+static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
+                                const char *buf, size_t count)
+{
+        unsigned int input;
+        int ret;
+        ret = sscanf(buf, "%u", &input);
+        if (ret != 1)
+                return -EINVAL;
+        limits.min_perf_pct = clamp_t(int, input, 0 , 100);
+        limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
+
+        return count;
+}
+
+show_one(no_turbo, no_turbo);
+show_one(max_perf_pct, max_perf_pct);
+show_one(min_perf_pct, min_perf_pct);
+
+define_one_global_rw(no_turbo);
+define_one_global_rw(max_perf_pct);
+define_one_global_rw(min_perf_pct);
+
+static struct attribute *intel_pstate_attributes[] = {
+        &no_turbo.attr,
+        &max_perf_pct.attr,
+        &min_perf_pct.attr,
+        NULL
+};
+
+static struct attribute_group intel_pstate_attr_group = {
+        .attrs = intel_pstate_attributes,
+};
+static struct kobject *intel_pstate_kobject;
+
+static void intel_pstate_sysfs_expose_params(void)
+{
+        int rc;
+
+        intel_pstate_kobject = kobject_create_and_add("intel_pstate",
+                                                &cpu_subsys.dev_root->kobj);
+        BUG_ON(!intel_pstate_kobject);
+        rc = sysfs_create_group(intel_pstate_kobject,
+                                &intel_pstate_attr_group);
+        BUG_ON(rc);
+}
+
+/************************** sysfs end ************************/
+
+static int intel_pstate_min_pstate(void)
+{
+        u64 value;
+        rdmsrl(0xCE, value);
+        return (value >> 40) & 0xFF;
+}
+
+static int intel_pstate_max_pstate(void)
+{
+        u64 value;
+        rdmsrl(0xCE, value);
+        return (value >> 8) & 0xFF;
+}
+
+static int intel_pstate_turbo_pstate(void)
+{
+        u64 value;
+        int nont, ret;
+        rdmsrl(0x1AD, value);
+        nont = intel_pstate_max_pstate();
+        ret = ((value) & 255);
+        if (ret <= nont)
+                ret = nont;
+        return ret;
+}
+
+static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
+{
+        int max_perf = cpu->pstate.turbo_pstate;
+        int min_perf;
+        if (limits.no_turbo)
+                max_perf = cpu->pstate.max_pstate;
+
+        max_perf = fp_toint(mul_fp(int_tofp(max_perf), limits.max_perf));
+        *max = clamp_t(int, max_perf,
+                        cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);
+
+        min_perf = fp_toint(mul_fp(int_tofp(max_perf), limits.min_perf));
+        *min = clamp_t(int, min_perf,
+                        cpu->pstate.min_pstate, max_perf);
+}
+
+static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
+{
+        int max_perf, min_perf;
+
+        intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
+
+        pstate = clamp_t(int, pstate, min_perf, max_perf);
+
+        if (pstate == cpu->pstate.current_pstate)
+                return;
+
+#ifndef MODULE
+        trace_cpu_frequency(pstate * 100000, cpu->cpu);
+#endif
+        cpu->pstate.current_pstate = pstate;
+        wrmsrl(MSR_IA32_PERF_CTL, pstate << 8);
+
+}
+
+static inline void intel_pstate_pstate_increase(struct cpudata *cpu, int steps)
+{
+        int target;
+        target = cpu->pstate.current_pstate + steps;
+
+        intel_pstate_set_pstate(cpu, target);
+}
+
+static inline void intel_pstate_pstate_decrease(struct cpudata *cpu, int steps)
+{
+        int target;
+        target = cpu->pstate.current_pstate - steps;
+        intel_pstate_set_pstate(cpu, target);
+}
+
+static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
+{
+        sprintf(cpu->name, "Intel 2nd generation core");
+
+        cpu->pstate.min_pstate = intel_pstate_min_pstate();
+        cpu->pstate.max_pstate = intel_pstate_max_pstate();
+        cpu->pstate.turbo_pstate = intel_pstate_turbo_pstate();
+
+        /*
+         * goto max pstate so we don't slow up boot if we are built-in if we are
+         * a module we will take care of it during normal operation
+         */
+        intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
+}
+
+static inline void intel_pstate_calc_busy(struct cpudata *cpu,
+                                        struct sample *sample)
+{
+        u64 core_pct;
+        sample->pstate_pct_busy = 100 - div64_u64(
+                                        sample->idletime_us * 100,
+                                        sample->duration_us);
+        core_pct = div64_u64(sample->aperf * 100, sample->mperf);
+        sample->freq = cpu->pstate.turbo_pstate * core_pct * 1000;
+
+        sample->core_pct_busy = div_s64((sample->pstate_pct_busy * core_pct),
+                                        100);
+}
+
+static inline void intel_pstate_sample(struct cpudata *cpu)
+{
+        ktime_t now;
+        u64 idle_time_us;
+        u64 aperf, mperf;
+
+        now = ktime_get();
+        idle_time_us = get_cpu_idle_time_us(cpu->cpu, NULL);
+
+        rdmsrl(MSR_IA32_APERF, aperf);
+        rdmsrl(MSR_IA32_MPERF, mperf);
+        /* for the first sample, don't actually record a sample, just
+         * set the baseline */
+        if (cpu->prev_idle_time_us > 0) {
+                cpu->sample_ptr = (cpu->sample_ptr + 1) % SAMPLE_COUNT;
+                cpu->samples[cpu->sample_ptr].start_time = cpu->prev_sample;
+                cpu->samples[cpu->sample_ptr].end_time = now;
+                cpu->samples[cpu->sample_ptr].duration_us =
+                        ktime_us_delta(now, cpu->prev_sample);
+                cpu->samples[cpu->sample_ptr].idletime_us =
+                        idle_time_us - cpu->prev_idle_time_us;
+
+                cpu->samples[cpu->sample_ptr].aperf = aperf;
+                cpu->samples[cpu->sample_ptr].mperf = mperf;
+                cpu->samples[cpu->sample_ptr].aperf -= cpu->prev_aperf;
+                cpu->samples[cpu->sample_ptr].mperf -= cpu->prev_mperf;
+
+                intel_pstate_calc_busy(cpu, &cpu->samples[cpu->sample_ptr]);
+        }
+
+        cpu->prev_sample = now;
+        cpu->prev_idle_time_us = idle_time_us;
+        cpu->prev_aperf = aperf;
+        cpu->prev_mperf = mperf;
+}
+
+static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
+{
+        int sample_time, delay;
+
+        sample_time = cpu->pstate_policy->sample_rate_ms;
+        delay = msecs_to_jiffies(sample_time);
+        delay -= jiffies % delay;
+        mod_timer_pinned(&cpu->timer, jiffies + delay);
+}
+
+static inline void intel_pstate_idle_mode(struct cpudata *cpu)
+{
+        cpu->idle_mode = 1;
+}
+
+static inline void intel_pstate_normal_mode(struct cpudata *cpu)
+{
+        cpu->idle_mode = 0;
+}
+
+static inline int intel_pstate_get_scaled_busy(struct cpudata *cpu)
+{
+        int32_t busy_scaled;
+        int32_t core_busy, turbo_pstate, current_pstate;
+
+        core_busy = int_tofp(cpu->samples[cpu->sample_ptr].core_pct_busy);
+        turbo_pstate = int_tofp(cpu->pstate.turbo_pstate);
+        current_pstate = int_tofp(cpu->pstate.current_pstate);
+        busy_scaled = mul_fp(core_busy, div_fp(turbo_pstate, current_pstate));
+
+        return fp_toint(busy_scaled);
+}
+
+static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
+{
+        int busy_scaled;
+        struct _pid *pid;
+        signed int ctl = 0;
+        int steps;
+
+        pid = &cpu->pid;
+        busy_scaled = intel_pstate_get_scaled_busy(cpu);
+
+        ctl = pid_calc(pid, busy_scaled);
+
+        steps = abs(ctl);
+        if (ctl < 0)
+                intel_pstate_pstate_increase(cpu, steps);
+        else
+                intel_pstate_pstate_decrease(cpu, steps);
+}
+
+static inline void intel_pstate_adjust_idle_pstate(struct cpudata *cpu)
+{
+        int busy_scaled;
+        struct _pid *pid;
+        int ctl = 0;
+        int steps;
+
+        pid = &cpu->idle_pid;
+
+        busy_scaled = intel_pstate_get_scaled_busy(cpu);
+
+        ctl = pid_calc(pid, 100 - busy_scaled);
+
+        steps = abs(ctl);
+        if (ctl < 0)
+                intel_pstate_pstate_decrease(cpu, steps);
+        else
+                intel_pstate_pstate_increase(cpu, steps);
+
+        if (cpu->pstate.current_pstate == cpu->pstate.min_pstate)
+                intel_pstate_normal_mode(cpu);
+}
+
+static void intel_pstate_timer_func(unsigned long __data)
+{
+        struct cpudata *cpu = (struct cpudata *) __data;
+
+        intel_pstate_sample(cpu);
+
+        if (!cpu->idle_mode)
+                intel_pstate_adjust_busy_pstate(cpu);
+        else
+                intel_pstate_adjust_idle_pstate(cpu);
+
+#if defined(XPERF_FIX)
+        if (cpu->pstate.current_pstate == cpu->pstate.min_pstate) {
+                cpu->min_pstate_count++;
+                if (!(cpu->min_pstate_count % 5)) {
+                        intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
+                        intel_pstate_idle_mode(cpu);
+                }
+        } else
+                cpu->min_pstate_count = 0;
+#endif
+        intel_pstate_set_sample_time(cpu);
+}
+
+#define ICPU(model, policy) \
+        { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&policy }
+
+static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
+        ICPU(0x2a, default_policy),
+        ICPU(0x2d, default_policy),
+        {}
+};
+MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
+
+static int intel_pstate_init_cpu(unsigned int cpunum)
+{
+
+        const struct x86_cpu_id *id;
+        struct cpudata *cpu;
+
+        id = x86_match_cpu(intel_pstate_cpu_ids);
+        if (!id)
+                return -ENODEV;
+
+        all_cpu_data[cpunum] = kzalloc(sizeof(struct cpudata), GFP_KERNEL);
+        if (!all_cpu_data[cpunum])
+                return -ENOMEM;
+
+        cpu = all_cpu_data[cpunum];
+
+        intel_pstate_get_cpu_pstates(cpu);
+
+        cpu->cpu = cpunum;
+        cpu->pstate_policy =
+                (struct pstate_adjust_policy *)id->driver_data;
+        init_timer_deferrable(&cpu->timer);
+        cpu->timer.function = intel_pstate_timer_func;
+        cpu->timer.data =
+                (unsigned long)cpu;
+        cpu->timer.expires = jiffies + HZ/100;
+        intel_pstate_busy_pid_reset(cpu);
+        intel_pstate_idle_pid_reset(cpu);
+        intel_pstate_sample(cpu);
+        intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
+
+        add_timer_on(&cpu->timer, cpunum);
+
+        pr_info("Intel pstate controlling: cpu %d\n", cpunum);
+
+        return 0;
+}
+
+static unsigned int intel_pstate_get(unsigned int cpu_num)
+{
+        struct sample *sample;
+        struct cpudata *cpu;
+
+        cpu = all_cpu_data[cpu_num];
+        if (!cpu)
+                return 0;
+        sample = &cpu->samples[cpu->sample_ptr];
+        return sample->freq;
+}
+
+static int intel_pstate_set_policy(struct cpufreq_policy *policy)
+{
+        struct cpudata *cpu;
+        int min, max;
+
+        cpu = all_cpu_data[policy->cpu];
+
+        intel_pstate_get_min_max(cpu, &min, &max);
+
+        limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
+        limits.min_perf_pct = clamp_t(int, limits.min_perf_pct, 0 , 100);
+        limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
+
+        limits.max_perf_pct = policy->max * 100 / policy->cpuinfo.max_freq;
+        limits.max_perf_pct = clamp_t(int, limits.max_perf_pct, 0 , 100);
+        limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
+
+        if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
+                limits.min_perf_pct = 100;
+                limits.min_perf = int_tofp(1);
+                limits.max_perf_pct = 100;
+                limits.max_perf = int_tofp(1);
+                limits.no_turbo = 0;
+        }
+
+        return 0;
+}
+
+static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
+{
+        cpufreq_verify_within_limits(policy,
+                                policy->cpuinfo.min_freq,
+                                policy->cpuinfo.max_freq);
+
+        if ((policy->policy != CPUFREQ_POLICY_POWERSAVE) &&
+                (policy->policy != CPUFREQ_POLICY_PERFORMANCE))
+                return -EINVAL;
+
+        return 0;
+}
+
+static int __cpuinit intel_pstate_cpu_exit(struct cpufreq_policy *policy)
+{
+        int cpu = policy->cpu;
+
+        del_timer(&all_cpu_data[cpu]->timer);
+        kfree(all_cpu_data[cpu]);
+        all_cpu_data[cpu] = NULL;
+        return 0;
+}
+
+static int __cpuinit intel_pstate_cpu_init(struct cpufreq_policy *policy)
+{
+        int rc, min_pstate, max_pstate;
+        struct cpudata *cpu;
+
+        rc = intel_pstate_init_cpu(policy->cpu);
+        if (rc)
+                return rc;
+
+        cpu = all_cpu_data[policy->cpu];
+
+        if (!limits.no_turbo &&
+                limits.min_perf_pct == 100 && limits.max_perf_pct == 100)
+                policy->policy = CPUFREQ_POLICY_PERFORMANCE;
+        else
+                policy->policy = CPUFREQ_POLICY_POWERSAVE;
+
+        intel_pstate_get_min_max(cpu, &min_pstate, &max_pstate);
+        policy->min = min_pstate * 100000;
+        policy->max = max_pstate * 100000;
+
+        /* cpuinfo and default policy values */
+        policy->cpuinfo.min_freq = cpu->pstate.min_pstate * 100000;
+        policy->cpuinfo.max_freq = cpu->pstate.turbo_pstate * 100000;
+        policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+        cpumask_set_cpu(policy->cpu, policy->cpus);
+
+        return 0;
+}
+
+static struct cpufreq_driver intel_pstate_driver = {
+        .flags          = CPUFREQ_CONST_LOOPS,
+        .verify         = intel_pstate_verify_policy,
+        .setpolicy      = intel_pstate_set_policy,
+        .get            = intel_pstate_get,
+        .init           = intel_pstate_cpu_init,
+        .exit           = intel_pstate_cpu_exit,
+        .name           = "intel_pstate",
+        .owner          = THIS_MODULE,
+};
+
+static void intel_pstate_exit(void)
+{
+        int cpu;
+
+        sysfs_remove_group(intel_pstate_kobject,
+                                &intel_pstate_attr_group);
+        debugfs_remove_recursive(debugfs_parent);
+
+        cpufreq_unregister_driver(&intel_pstate_driver);
+
+        if (!all_cpu_data)
+                return;
+
+        get_online_cpus();
+        for_each_online_cpu(cpu) {
+                if (all_cpu_data[cpu]) {
+                        del_timer_sync(&all_cpu_data[cpu]->timer);
+                        kfree(all_cpu_data[cpu]);
+                }
+        }
+
+        put_online_cpus();
+        vfree(all_cpu_data);
+}
+module_exit(intel_pstate_exit);
+
+static int __init intel_pstate_init(void)
+{
+        int rc = 0;
+        const struct x86_cpu_id *id;
+
+        id = x86_match_cpu(intel_pstate_cpu_ids);
+        if (!id)
+                return -ENODEV;
+
+        pr_info("Intel P-state driver initializing.\n");
+
+        all_cpu_data = vmalloc(sizeof(void *) * num_possible_cpus());
+        if (!all_cpu_data)
+                return -ENOMEM;
+        memset(all_cpu_data, 0, sizeof(void *) * num_possible_cpus());
+
+        rc = cpufreq_register_driver(&intel_pstate_driver);
+        if (rc)
+                goto out;
+
+        intel_pstate_debug_expose_params();
+        intel_pstate_sysfs_expose_params();
+        return rc;
+out:
+        intel_pstate_exit();
+        return -ENODEV;
+}
+device_initcall(intel_pstate_init);
+
+MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>");
+MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");
+MODULE_LICENSE("GPL");