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intel_pstate.c
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/*
* intel_pstate.c: Native P state management for Intel processors
*
* (C) Copyright 2012 Intel Corporation
* Author: Dirk Brandewie <[email protected]>
*
* 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 <linux/acpi.h>
#include <trace/events/power.h>
#include <asm/div64.h>
#include <asm/msr.h>
#include <asm/cpu_device_id.h>
#define BYT_RATIOS 0x66a
#define BYT_VIDS 0x66b
#define BYT_TURBO_RATIOS 0x66c
#define BYT_TURBO_VIDS 0x66d
#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, y);
}
static inline int ceiling_fp(int32_t x)
{
int mask, ret;
ret = fp_toint(x);
mask = (1 << FRAC_BITS) - 1;
if (x & mask)
ret += 1;
return ret;
}
struct sample {
int32_t core_pct_busy;
u64 aperf;
u64 mperf;
int freq;
ktime_t time;
};
struct pstate_data {
int current_pstate;
int min_pstate;
int max_pstate;
int scaling;
int turbo_pstate;
};
struct vid_data {
int min;
int max;
int turbo;
int32_t ratio;
};
struct _pid {
int setpoint;
int32_t integral;
int32_t p_gain;
int32_t i_gain;
int32_t d_gain;
int deadband;
int32_t last_err;
};
struct cpudata {
int cpu;
struct timer_list timer;
struct pstate_data pstate;
struct vid_data vid;
struct _pid pid;
ktime_t last_sample_time;
u64 prev_aperf;
u64 prev_mperf;
struct sample sample;
};
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;
};
struct pstate_funcs {
int (*get_max)(void);
int (*get_min)(void);
int (*get_turbo)(void);
int (*get_scaling)(void);
void (*set)(struct cpudata*, int pstate);
void (*get_vid)(struct cpudata *);
};
struct cpu_defaults {
struct pstate_adjust_policy pid_policy;
struct pstate_funcs funcs;
};
static struct pstate_adjust_policy pid_params;
static struct pstate_funcs pstate_funcs;
static int hwp_active;
struct perf_limits {
int no_turbo;
int turbo_disabled;
int max_perf_pct;
int min_perf_pct;
int32_t max_perf;
int32_t min_perf;
int max_policy_pct;
int max_sysfs_pct;
};
static struct perf_limits limits = {
.no_turbo = 0,
.turbo_disabled = 0,
.max_perf_pct = 100,
.max_perf = int_tofp(1),
.min_perf_pct = 0,
.min_perf = 0,
.max_policy_pct = 100,
.max_sysfs_pct = 100,
};
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 = int_tofp(setpoint) - int_tofp(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, int32_t busy)
{
signed int result;
int32_t pterm, dterm, fp_error;
int32_t integral_limit;
fp_error = int_tofp(pid->setpoint) - busy;
if (abs(fp_error) <= int_tofp(pid->deadband))
return 0;
pterm = mul_fp(pid->p_gain, fp_error);
pid->integral += fp_error;
/*
* We limit the integral here so that it will never
* get higher than 30. This prevents it from becoming
* too large an input over long periods of time and allows
* it to get factored out sooner.
*
* The value of 30 was chosen through experimentation.
*/
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, fp_error - pid->last_err);
pid->last_err = fp_error;
result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
result = result + (1 << (FRAC_BITS-1));
return (signed int)fp_toint(result);
}
static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
{
pid_p_gain_set(&cpu->pid, pid_params.p_gain_pct);
pid_d_gain_set(&cpu->pid, pid_params.d_gain_pct);
pid_i_gain_set(&cpu->pid, pid_params.i_gain_pct);
pid_reset(&cpu->pid, pid_params.setpoint, 100, pid_params.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]);
}
}
static inline void update_turbo_state(void)
{
u64 misc_en;
struct cpudata *cpu;
cpu = all_cpu_data[0];
rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
limits.turbo_disabled =
(misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE ||
cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
}
#define PCT_TO_HWP(x) (x * 255 / 100)
static void intel_pstate_hwp_set(void)
{
int min, max, cpu;
u64 value, freq;
get_online_cpus();
for_each_online_cpu(cpu) {
rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
min = PCT_TO_HWP(limits.min_perf_pct);
value &= ~HWP_MIN_PERF(~0L);
value |= HWP_MIN_PERF(min);
max = PCT_TO_HWP(limits.max_perf_pct);
if (limits.no_turbo) {
rdmsrl( MSR_HWP_CAPABILITIES, freq);
max = HWP_GUARANTEED_PERF(freq);
}
value &= ~HWP_MAX_PERF(~0L);
value |= HWP_MAX_PERF(max);
wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
}
put_online_cpus();
}
/************************** 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", &pid_params.sample_rate_ms},
{"d_gain_pct", &pid_params.d_gain_pct},
{"i_gain_pct", &pid_params.i_gain_pct},
{"deadband", &pid_params.deadband},
{"setpoint", &pid_params.setpoint},
{"p_gain_pct", &pid_params.p_gain_pct},
{NULL, NULL}
};
static void __init intel_pstate_debug_expose_params(void)
{
struct dentry *debugfs_parent;
int i = 0;
if (hwp_active)
return;
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 show_no_turbo(struct kobject *kobj,
struct attribute *attr, char *buf)
{
ssize_t ret;
update_turbo_state();
if (limits.turbo_disabled)
ret = sprintf(buf, "%u\n", limits.turbo_disabled);
else
ret = sprintf(buf, "%u\n", limits.no_turbo);
return ret;
}
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;
update_turbo_state();
if (limits.turbo_disabled) {
pr_warn("Turbo disabled by BIOS or unavailable on processor\n");
return -EPERM;
}
limits.no_turbo = clamp_t(int, input, 0, 1);
if (hwp_active)
intel_pstate_hwp_set();
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_sysfs_pct = clamp_t(int, input, 0 , 100);
limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
if (hwp_active)
intel_pstate_hwp_set();
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));
if (hwp_active)
intel_pstate_hwp_set();
return count;
}
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 void __init intel_pstate_sysfs_expose_params(void)
{
struct kobject *intel_pstate_kobject;
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 void intel_pstate_hwp_enable(void)
{
hwp_active++;
pr_info("intel_pstate HWP enabled\n");
wrmsrl( MSR_PM_ENABLE, 0x1);
}
static int byt_get_min_pstate(void)
{
u64 value;
rdmsrl(BYT_RATIOS, value);
return (value >> 8) & 0x7F;
}
static int byt_get_max_pstate(void)
{
u64 value;
rdmsrl(BYT_RATIOS, value);
return (value >> 16) & 0x7F;
}
static int byt_get_turbo_pstate(void)
{
u64 value;
rdmsrl(BYT_TURBO_RATIOS, value);
return value & 0x7F;
}
static void byt_set_pstate(struct cpudata *cpudata, int pstate)
{
u64 val;
int32_t vid_fp;
u32 vid;
val = pstate << 8;
if (limits.no_turbo && !limits.turbo_disabled)
val |= (u64)1 << 32;
vid_fp = cpudata->vid.min + mul_fp(
int_tofp(pstate - cpudata->pstate.min_pstate),
cpudata->vid.ratio);
vid_fp = clamp_t(int32_t, vid_fp, cpudata->vid.min, cpudata->vid.max);
vid = ceiling_fp(vid_fp);
if (pstate > cpudata->pstate.max_pstate)
vid = cpudata->vid.turbo;
val |= vid;
wrmsrl(MSR_IA32_PERF_CTL, val);
}
#define BYT_BCLK_FREQS 5
static int byt_freq_table[BYT_BCLK_FREQS] = { 833, 1000, 1333, 1167, 800};
static int byt_get_scaling(void)
{
u64 value;
int i;
rdmsrl(MSR_FSB_FREQ, value);
i = value & 0x3;
BUG_ON(i > BYT_BCLK_FREQS);
return byt_freq_table[i] * 100;
}
static void byt_get_vid(struct cpudata *cpudata)
{
u64 value;
rdmsrl(BYT_VIDS, value);
cpudata->vid.min = int_tofp((value >> 8) & 0x7f);
cpudata->vid.max = int_tofp((value >> 16) & 0x7f);
cpudata->vid.ratio = div_fp(
cpudata->vid.max - cpudata->vid.min,
int_tofp(cpudata->pstate.max_pstate -
cpudata->pstate.min_pstate));
rdmsrl(BYT_TURBO_VIDS, value);
cpudata->vid.turbo = value & 0x7f;
}
static int core_get_min_pstate(void)
{
u64 value;
rdmsrl(MSR_PLATFORM_INFO, value);
return (value >> 40) & 0xFF;
}
static int core_get_max_pstate(void)
{
u64 value;
rdmsrl(MSR_PLATFORM_INFO, value);
return (value >> 8) & 0xFF;
}
static int core_get_turbo_pstate(void)
{
u64 value;
int nont, ret;
rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
nont = core_get_max_pstate();
ret = (value) & 255;
if (ret <= nont)
ret = nont;
return ret;
}
static inline int core_get_scaling(void)
{
return 100000;
}
static void core_set_pstate(struct cpudata *cpudata, int pstate)
{
u64 val;
val = pstate << 8;
if (limits.no_turbo && !limits.turbo_disabled)
val |= (u64)1 << 32;
wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
}
static struct cpu_defaults core_params = {
.pid_policy = {
.sample_rate_ms = 10,
.deadband = 0,
.setpoint = 97,
.p_gain_pct = 20,
.d_gain_pct = 0,
.i_gain_pct = 0,
},
.funcs = {
.get_max = core_get_max_pstate,
.get_min = core_get_min_pstate,
.get_turbo = core_get_turbo_pstate,
.get_scaling = core_get_scaling,
.set = core_set_pstate,
},
};
static struct cpu_defaults byt_params = {
.pid_policy = {
.sample_rate_ms = 10,
.deadband = 0,
.setpoint = 97,
.p_gain_pct = 14,
.d_gain_pct = 0,
.i_gain_pct = 4,
},
.funcs = {
.get_max = byt_get_max_pstate,
.get_min = byt_get_min_pstate,
.get_turbo = byt_get_turbo_pstate,
.set = byt_set_pstate,
.get_scaling = byt_get_scaling,
.get_vid = byt_get_vid,
},
};
static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
{
int max_perf = cpu->pstate.turbo_pstate;
int max_perf_adj;
int min_perf;
if (limits.no_turbo || limits.turbo_disabled)
max_perf = cpu->pstate.max_pstate;
/*
* performance can be limited by user through sysfs, by cpufreq
* policy, or by cpu specific default values determined through
* experimentation.
*/
max_perf_adj = fp_toint(mul_fp(int_tofp(max_perf), limits.max_perf));
*max = clamp_t(int, max_perf_adj,
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;
update_turbo_state();
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;
trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
cpu->pstate.current_pstate = pstate;
pstate_funcs.set(cpu, pstate);
}
static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
{
cpu->pstate.min_pstate = pstate_funcs.get_min();
cpu->pstate.max_pstate = pstate_funcs.get_max();
cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
cpu->pstate.scaling = pstate_funcs.get_scaling();
if (pstate_funcs.get_vid)
pstate_funcs.get_vid(cpu);
intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
}
static inline void intel_pstate_calc_busy(struct cpudata *cpu)
{
struct sample *sample = &cpu->sample;
int64_t core_pct;
core_pct = int_tofp(sample->aperf) * int_tofp(100);
core_pct = div64_u64(core_pct, int_tofp(sample->mperf));
sample->freq = fp_toint(
mul_fp(int_tofp(
cpu->pstate.max_pstate * cpu->pstate.scaling / 100),
core_pct));
sample->core_pct_busy = (int32_t)core_pct;
}
static inline void intel_pstate_sample(struct cpudata *cpu)
{
u64 aperf, mperf;
unsigned long flags;
local_irq_save(flags);
rdmsrl(MSR_IA32_APERF, aperf);
rdmsrl(MSR_IA32_MPERF, mperf);
local_irq_restore(flags);
cpu->last_sample_time = cpu->sample.time;
cpu->sample.time = ktime_get();
cpu->sample.aperf = aperf;
cpu->sample.mperf = mperf;
cpu->sample.aperf -= cpu->prev_aperf;
cpu->sample.mperf -= cpu->prev_mperf;
intel_pstate_calc_busy(cpu);
cpu->prev_aperf = aperf;
cpu->prev_mperf = mperf;
}
static inline void intel_hwp_set_sample_time(struct cpudata *cpu)
{
int delay;
delay = msecs_to_jiffies(50);
mod_timer_pinned(&cpu->timer, jiffies + delay);
}
static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
{
int delay;
delay = msecs_to_jiffies(pid_params.sample_rate_ms);
mod_timer_pinned(&cpu->timer, jiffies + delay);
}
static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
{
int32_t core_busy, max_pstate, current_pstate, sample_ratio;
u32 duration_us;
u32 sample_time;
/*
* core_busy is the ratio of actual performance to max
* max_pstate is the max non turbo pstate available
* current_pstate was the pstate that was requested during
* the last sample period.
*
* We normalize core_busy, which was our actual percent
* performance to what we requested during the last sample
* period. The result will be a percentage of busy at a
* specified pstate.
*/
core_busy = cpu->sample.core_pct_busy;
max_pstate = int_tofp(cpu->pstate.max_pstate);
current_pstate = int_tofp(cpu->pstate.current_pstate);
core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
/*
* Since we have a deferred timer, it will not fire unless
* we are in C0. So, determine if the actual elapsed time
* is significantly greater (3x) than our sample interval. If it
* is, then we were idle for a long enough period of time
* to adjust our busyness.
*/
sample_time = pid_params.sample_rate_ms * USEC_PER_MSEC;
duration_us = (u32) ktime_us_delta(cpu->sample.time,
cpu->last_sample_time);
if (duration_us > sample_time * 3) {
sample_ratio = div_fp(int_tofp(sample_time),
int_tofp(duration_us));
core_busy = mul_fp(core_busy, sample_ratio);
}
return core_busy;
}
static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
{
int32_t busy_scaled;
struct _pid *pid;
signed int ctl;
pid = &cpu->pid;
busy_scaled = intel_pstate_get_scaled_busy(cpu);
ctl = pid_calc(pid, busy_scaled);
/* Negative values of ctl increase the pstate and vice versa */
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl);
}
static void intel_hwp_timer_func(unsigned long __data)
{
struct cpudata *cpu = (struct cpudata *) __data;
intel_pstate_sample(cpu);
intel_hwp_set_sample_time(cpu);
}
static void intel_pstate_timer_func(unsigned long __data)
{
struct cpudata *cpu = (struct cpudata *) __data;
struct sample *sample;
intel_pstate_sample(cpu);
sample = &cpu->sample;
intel_pstate_adjust_busy_pstate(cpu);
trace_pstate_sample(fp_toint(sample->core_pct_busy),
fp_toint(intel_pstate_get_scaled_busy(cpu)),
cpu->pstate.current_pstate,
sample->mperf,
sample->aperf,
sample->freq);
intel_pstate_set_sample_time(cpu);
}
#define ICPU(model, policy) \
{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_APERFMPERF,\
(unsigned long)&policy }
static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
ICPU(0x2a, core_params),
ICPU(0x2d, core_params),
ICPU(0x37, byt_params),
ICPU(0x3a, core_params),
ICPU(0x3c, core_params),
ICPU(0x3d, core_params),
ICPU(0x3e, core_params),
ICPU(0x3f, core_params),
ICPU(0x45, core_params),
ICPU(0x46, core_params),
ICPU(0x47, core_params),
ICPU(0x4c, byt_params),
ICPU(0x4f, core_params),
ICPU(0x56, core_params),
{}
};
MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] = {
ICPU(0x56, core_params),
{}
};
static int intel_pstate_init_cpu(unsigned int cpunum)
{
struct cpudata *cpu;
if (!all_cpu_data[cpunum])
all_cpu_data[cpunum] = kzalloc(sizeof(struct cpudata),
GFP_KERNEL);
if (!all_cpu_data[cpunum])
return -ENOMEM;
cpu = all_cpu_data[cpunum];
cpu->cpu = cpunum;
intel_pstate_get_cpu_pstates(cpu);
init_timer_deferrable(&cpu->timer);
cpu->timer.data = (unsigned long)cpu;
cpu->timer.expires = jiffies + HZ/100;
if (!hwp_active)
cpu->timer.function = intel_pstate_timer_func;
else
cpu->timer.function = intel_hwp_timer_func;
intel_pstate_busy_pid_reset(cpu);
intel_pstate_sample(cpu);
add_timer_on(&cpu->timer, cpunum);
pr_debug("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->sample;
return sample->freq;
}
static int intel_pstate_set_policy(struct cpufreq_policy *policy)
{
if (!policy->cpuinfo.max_freq)
return -ENODEV;
if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
limits.min_perf_pct = 100;
limits.min_perf = int_tofp(1);
limits.max_policy_pct = 100;
limits.max_perf_pct = 100;
limits.max_perf = int_tofp(1);
limits.no_turbo = 0;
return 0;
}
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_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq;
limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100);
limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
if (hwp_active)
intel_pstate_hwp_set();
return 0;
}
static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
{
cpufreq_verify_within_cpu_limits(policy);
if (policy->policy != CPUFREQ_POLICY_POWERSAVE &&
policy->policy != CPUFREQ_POLICY_PERFORMANCE)
return -EINVAL;
return 0;
}
static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
{
int cpu_num = policy->cpu;
struct cpudata *cpu = all_cpu_data[cpu_num];
pr_info("intel_pstate CPU %d exiting\n", cpu_num);
del_timer_sync(&all_cpu_data[cpu_num]->timer);
if (hwp_active)
return;
intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
}
static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
{
struct cpudata *cpu;
int rc;
rc = intel_pstate_init_cpu(policy->cpu);
if (rc)
return rc;
cpu = all_cpu_data[policy->cpu];
if (limits.min_perf_pct == 100 && limits.max_perf_pct == 100)
policy->policy = CPUFREQ_POLICY_PERFORMANCE;
else
policy->policy = CPUFREQ_POLICY_POWERSAVE;
policy->min = cpu->pstate.min_pstate * cpu->pstate.scaling;
policy->max = cpu->pstate.turbo_pstate * cpu->pstate.scaling;
/* cpuinfo and default policy values */
policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
policy->cpuinfo.max_freq =
cpu->pstate.turbo_pstate * cpu->pstate.scaling;
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,
.stop_cpu = intel_pstate_stop_cpu,
.name = "intel_pstate",
};
static int __initdata no_load;
static int __initdata no_hwp;
static unsigned int force_load;
static int intel_pstate_msrs_not_valid(void)
{
/* Check that all the msr's we are using are valid. */
u64 aperf, mperf, tmp;
rdmsrl(MSR_IA32_APERF, aperf);
rdmsrl(MSR_IA32_MPERF, mperf);
if (!pstate_funcs.get_max() ||
!pstate_funcs.get_min() ||
!pstate_funcs.get_turbo())
return -ENODEV;
rdmsrl(MSR_IA32_APERF, tmp);
if (!(tmp - aperf))
return -ENODEV;
rdmsrl(MSR_IA32_MPERF, tmp);