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Merge branch 'pm-cpufreq'

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* pm-cpufreq: (21 commits)
  cpufreq: ondemand: update sampling rate only on right CPUs
  cpufreq: SPEAr: Add CPUFreq driver
  cpufreq: governors: Fix jiffies/cputime mixup (revisited)
  cpufreq: ondemand: fix wrong delay sampling rate
  cpufreq: exynos: Use static for functions used in only this file
  cpufreq: exynos: Broadcast frequency change notifications for all cores
  cpufreq: remove use of __devexit
  cpufreq: remove use of __devinit
  cpufreq: remove use of __devexit_p
  cpufreq: Remove unnecessary initialization of a local variable
  cpufreq: Make sure target freq is within limits
  cpufreq: Avoid calling cpufreq driver's target() routine if target_freq == policy->cur
  cpufreq: Fix sparse warning by making local function static
  cpufreq: Fix sparse warnings by updating cputime64_t to u64
  cpufreq: governors: remove redundant code
  cpufreq: return early from __cpufreq_driver_getavg()
  cpufreq: fix jiffies/cputime mixup in conservative/ondemand governors
  cpufreq: Improve debug prints
  cpufreq: Move common part from governors to separate file, v2
  cpufreq / core: Fix printing of governor and driver name
  ...
This commit is contained in:
Rafael J. Wysocki 2012-11-29 21:46:04 +01:00
commit aa84950674
20 changed files with 1285 additions and 959 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
Documentation/devicetree/bindings/cpufreq/cpufreq-spear.txt Normal file
View File

@ -0,0 +1,42 @@
SPEAr cpufreq driver
-------------------
SPEAr SoC cpufreq driver for CPU frequency scaling.
It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) systems
which share clock across all CPUs.
Required properties:
- cpufreq_tbl: Table of frequencies CPU could be transitioned into, in the
increasing order.
Optional properties:
- clock-latency: Specify the possible maximum transition latency for clock, in
unit of nanoseconds.
Both required and optional properties listed above must be defined under node
/cpus/cpu@0.
Examples:
--------
cpus {
<...>
cpu@0 {
compatible = "arm,cortex-a9";
reg = <0>;
<...>
cpufreq_tbl = < 166000
200000
250000
300000
400000
500000
600000 >;
};
<...>
};

1
arch/arm/Kconfig
View File

@ -904,6 +904,7 @@ config ARCH_NOMADIK
config PLAT_SPEAR
bool "ST SPEAr"
select ARCH_HAS_CPUFREQ
select ARCH_REQUIRE_GPIOLIB
select ARM_AMBA
select CLKDEV_LOOKUP

7
drivers/cpufreq/Kconfig.arm
View File

@ -76,3 +76,10 @@ config ARM_EXYNOS5250_CPUFREQ
help
This adds the CPUFreq driver for Samsung EXYNOS5250
SoC.
config ARM_SPEAR_CPUFREQ
bool "SPEAr CPUFreq support"
depends on PLAT_SPEAR
default y
help
This adds the CPUFreq driver support for SPEAr SOCs.

5
drivers/cpufreq/Makefile
View File

@ -7,8 +7,8 @@ obj-$(CONFIG_CPU_FREQ_STAT) += cpufreq_stats.o
obj-$(CONFIG_CPU_FREQ_GOV_PERFORMANCE) += cpufreq_performance.o
obj-$(CONFIG_CPU_FREQ_GOV_POWERSAVE) += cpufreq_powersave.o
obj-$(CONFIG_CPU_FREQ_GOV_USERSPACE) += cpufreq_userspace.o
obj-$(CONFIG_CPU_FREQ_GOV_ONDEMAND) += cpufreq_ondemand.o
obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE) += cpufreq_conservative.o
obj-$(CONFIG_CPU_FREQ_GOV_ONDEMAND) += cpufreq_ondemand.o cpufreq_governor.o
obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE) += cpufreq_conservative.o cpufreq_governor.o
# CPUfreq cross-arch helpers
obj-$(CONFIG_CPU_FREQ_TABLE) += freq_table.o
@ -50,6 +50,7 @@ obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS4X12_CPUFREQ) += exynos4x12-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS5250_CPUFREQ) += exynos5250-cpufreq.o
obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o
obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o
##################################################################################
# PowerPC platform drivers

2
drivers/cpufreq/cpufreq-cpu0.c
View File

@ -174,7 +174,7 @@ static struct cpufreq_driver cpu0_cpufreq_driver = {
.attr = cpu0_cpufreq_attr,
};
static int __devinit cpu0_cpufreq_driver_init(void)
static int cpu0_cpufreq_driver_init(void)
{
struct device_node *np;
int ret;

37
drivers/cpufreq/cpufreq.c
View File

@ -15,6 +15,8 @@
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
@ -127,7 +129,7 @@ static int __init init_cpufreq_transition_notifier_list(void)
pure_initcall(init_cpufreq_transition_notifier_list);
static int off __read_mostly;
int cpufreq_disabled(void)
static int cpufreq_disabled(void)
{
return off;
}
@ -402,7 +404,7 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data,
static ssize_t store_##file_name \
(struct cpufreq_policy *policy, const char *buf, size_t count) \
{ \
unsigned int ret = -EINVAL; \
unsigned int ret; \
struct cpufreq_policy new_policy; \
\
ret = cpufreq_get_policy(&new_policy, policy->cpu); \
@ -445,7 +447,7 @@ static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
return sprintf(buf, "performance\n");
else if (policy->governor)
return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n",
return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
policy->governor->name);
return -EINVAL;
}
@ -457,7 +459,7 @@ static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
const char *buf, size_t count)
{
unsigned int ret = -EINVAL;
unsigned int ret;
char str_governor[16];
struct cpufreq_policy new_policy;
@ -491,7 +493,7 @@ static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
*/
static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
{
return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
}
/**
@ -512,7 +514,7 @@ static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
- (CPUFREQ_NAME_LEN + 2)))
goto out;
i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
}
out:
i += sprintf(&buf[i], "\n");
@ -581,7 +583,7 @@ static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
}
/**
* show_scaling_driver - show the current cpufreq HW/BIOS limitation
* show_bios_limit - show the current cpufreq HW/BIOS limitation
*/
static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
{
@ -1468,12 +1470,23 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
unsigned int relation)
{
int retval = -EINVAL;
unsigned int old_target_freq = target_freq;
if (cpufreq_disabled())
return -ENODEV;
pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
target_freq, relation);
/* 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);
if (target_freq == policy->cur)
return 0;
if (cpu_online(policy->cpu) && cpufreq_driver->target)
retval = cpufreq_driver->target(policy, target_freq, relation);
@ -1509,12 +1522,14 @@ int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu)
{
int ret = 0;
if (!(cpu_online(cpu) && cpufreq_driver->getavg))
return 0;
policy = cpufreq_cpu_get(policy->cpu);
if (!policy)
return -EINVAL;
if (cpu_online(cpu) && cpufreq_driver->getavg)
ret = cpufreq_driver->getavg(policy, cpu);
ret = cpufreq_driver->getavg(policy, cpu);
cpufreq_cpu_put(policy);
return ret;

592
drivers/cpufreq/cpufreq_conservative.c
View File

@ -11,83 +11,30 @@
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/cpu.h>
#include <linux/jiffies.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/hrtimer.h>
#include <linux/tick.h>
#include <linux/ktime.h>
#include <linux/sched.h>
#include <linux/notifier.h>
#include <linux/percpu-defs.h>
#include <linux/sysfs.h>
#include <linux/types.h>
/*
* dbs is used in this file as a shortform for demandbased switching
* It helps to keep variable names smaller, simpler
*/
#include "cpufreq_governor.h"
/* Conservative governor macors */
#define DEF_FREQUENCY_UP_THRESHOLD (80)
#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
/*
* The polling frequency of this governor depends on the capability of
* the processor. Default polling frequency is 1000 times the transition
* latency of the processor. The governor will work on any processor with
* transition latency <= 10mS, using appropriate sampling
* rate.
* For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL)
* this governor will not work.
* All times here are in uS.
*/
#define MIN_SAMPLING_RATE_RATIO (2)
static unsigned int min_sampling_rate;
#define LATENCY_MULTIPLIER (1000)
#define MIN_LATENCY_MULTIPLIER (100)
#define DEF_SAMPLING_DOWN_FACTOR (1)
#define MAX_SAMPLING_DOWN_FACTOR (10)
#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
static void do_dbs_timer(struct work_struct *work);
static struct dbs_data cs_dbs_data;
static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);
struct cpu_dbs_info_s {
cputime64_t prev_cpu_idle;
cputime64_t prev_cpu_wall;
cputime64_t prev_cpu_nice;
struct cpufreq_policy *cur_policy;
struct delayed_work work;
unsigned int down_skip;
unsigned int requested_freq;
int cpu;
unsigned int enable:1;
/*
* percpu mutex that serializes governor limit change with
* do_dbs_timer invocation. We do not want do_dbs_timer to run
* when user is changing the governor or limits.
*/
struct mutex timer_mutex;
};
static DEFINE_PER_CPU(struct cpu_dbs_info_s, cs_cpu_dbs_info);
static unsigned int dbs_enable; /* number of CPUs using this policy */
/*
* dbs_mutex protects dbs_enable in governor start/stop.
*/
static DEFINE_MUTEX(dbs_mutex);
static struct dbs_tuners {
unsigned int sampling_rate;
unsigned int sampling_down_factor;
unsigned int up_threshold;
unsigned int down_threshold;
unsigned int ignore_nice;
unsigned int freq_step;
} dbs_tuners_ins = {
static struct cs_dbs_tuners cs_tuners = {
.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
.down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD,
.sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
@ -95,95 +42,121 @@ static struct dbs_tuners {
.freq_step = 5,
};
static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
/*
* Every sampling_rate, we check, if current idle time is less than 20%
* (default), then we try to increase frequency Every sampling_rate *
* sampling_down_factor, we check, if current idle time is more than 80%, then
* we try to decrease frequency
*
* Any frequency increase takes it to the maximum frequency. Frequency reduction
* happens at minimum steps of 5% (default) of maximum frequency
*/
static void cs_check_cpu(int cpu, unsigned int load)
{
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 = jiffies_to_usecs(cur_wall_time);
return jiffies_to_usecs(idle_time);
}
static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
{
u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
if (idle_time == -1ULL)
return get_cpu_idle_time_jiffy(cpu, wall);
else
idle_time += get_cpu_iowait_time_us(cpu, wall);
return idle_time;
}
/* keep track of frequency transitions */
static int
dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
void *data)
{
struct cpufreq_freqs *freq = data;
struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cs_cpu_dbs_info,
freq->cpu);
struct cpufreq_policy *policy;
if (!this_dbs_info->enable)
return 0;
policy = this_dbs_info->cur_policy;
struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
unsigned int freq_target;
/*
* we only care if our internally tracked freq moves outside
* the 'valid' ranges of freqency available to us otherwise
* we do not change it
* break out if we 'cannot' reduce the speed as the user might
* want freq_step to be zero
*/
if (cs_tuners.freq_step == 0)
return;
/* Check for frequency increase */
if (load > cs_tuners.up_threshold) {
dbs_info->down_skip = 0;
/* if we are already at full speed then break out early */
if (dbs_info->requested_freq == policy->max)
return;
freq_target = (cs_tuners.freq_step * policy->max) / 100;
/* max freq cannot be less than 100. But who knows.... */
if (unlikely(freq_target == 0))
freq_target = 5;
dbs_info->requested_freq += freq_target;
if (dbs_info->requested_freq > policy->max)
dbs_info->requested_freq = policy->max;
__cpufreq_driver_target(policy, dbs_info->requested_freq,
CPUFREQ_RELATION_H);
return;
}
/*
* The optimal frequency is the frequency that is the lowest that can
* support the current CPU usage without triggering the up policy. To be
* safe, we focus 10 points under the threshold.
*/
if (load < (cs_tuners.down_threshold - 10)) {
freq_target = (cs_tuners.freq_step * policy->max) / 100;
dbs_info->requested_freq -= freq_target;
if (dbs_info->requested_freq < policy->min)
dbs_info->requested_freq = policy->min;
/*
* if we cannot reduce the frequency anymore, break out early
*/
if (policy->cur == policy->min)
return;
__cpufreq_driver_target(policy, dbs_info->requested_freq,
CPUFREQ_RELATION_H);
return;
}
}
static void cs_dbs_timer(struct work_struct *work)
{
struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
struct cs_cpu_dbs_info_s, cdbs.work.work);
unsigned int cpu = dbs_info->cdbs.cpu;
int delay = delay_for_sampling_rate(cs_tuners.sampling_rate);
mutex_lock(&dbs_info->cdbs.timer_mutex);
dbs_check_cpu(&cs_dbs_data, cpu);
schedule_delayed_work_on(cpu, &dbs_info->cdbs.work, delay);
mutex_unlock(&dbs_info->cdbs.timer_mutex);
}
static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
void *data)
{
struct cpufreq_freqs *freq = data;
struct cs_cpu_dbs_info_s *dbs_info =
&per_cpu(cs_cpu_dbs_info, freq->cpu);
struct cpufreq_policy *policy;
if (!dbs_info->enable)
return 0;
policy = dbs_info->cdbs.cur_policy;
/*
* we only care if our internally tracked freq moves outside the 'valid'
* ranges of freqency available to us otherwise we do not change it
*/
if (this_dbs_info->requested_freq > policy->max
|| this_dbs_info->requested_freq < policy->min)
this_dbs_info->requested_freq = freq->new;
if (dbs_info->requested_freq > policy->max
|| dbs_info->requested_freq < policy->min)
dbs_info->requested_freq = freq->new;
return 0;
}
static struct notifier_block dbs_cpufreq_notifier_block = {
.notifier_call = dbs_cpufreq_notifier
};
/************************** sysfs interface ************************/
static ssize_t show_sampling_rate_min(struct kobject *kobj,
struct attribute *attr, char *buf)
{
return sprintf(buf, "%u\n", min_sampling_rate);
return sprintf(buf, "%u\n", cs_dbs_data.min_sampling_rate);
}
define_one_global_ro(sampling_rate_min);
/* cpufreq_conservative Governor Tunables */
#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", dbs_tuners_ins.object); \
}
show_one(sampling_rate, sampling_rate);
show_one(sampling_down_factor, sampling_down_factor);
show_one(up_threshold, up_threshold);
show_one(down_threshold, down_threshold);
show_one(ignore_nice_load, ignore_nice);
show_one(freq_step, freq_step);
static ssize_t store_sampling_down_factor(struct kobject *a,
struct attribute *b,
const char *buf, size_t count)
@ -195,7 +168,7 @@ static ssize_t store_sampling_down_factor(struct kobject *a,
if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
return -EINVAL;
dbs_tuners_ins.sampling_down_factor = input;
cs_tuners.sampling_down_factor = input;
return count;
}
@ -209,7 +182,7 @@ static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b,
if (ret != 1)
return -EINVAL;
dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate);
cs_tuners.sampling_rate = max(input, cs_dbs_data.min_sampling_rate);
return count;
}
@ -220,11 +193,10 @@ static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
int ret;
ret = sscanf(buf, "%u", &input);
if (ret != 1 || input > 100 ||
input <= dbs_tuners_ins.down_threshold)
if (ret != 1 || input > 100 || input <= cs_tuners.down_threshold)
return -EINVAL;
dbs_tuners_ins.up_threshold = input;
cs_tuners.up_threshold = input;
return count;
}
@ -237,21 +209,19 @@ static ssize_t store_down_threshold(struct kobject *a, struct attribute *b,
/* cannot be lower than 11 otherwise freq will not fall */
if (ret != 1 || input < 11 || input > 100 ||
input >= dbs_tuners_ins.up_threshold)
input >= cs_tuners.up_threshold)
return -EINVAL;
dbs_tuners_ins.down_threshold = input;
cs_tuners.down_threshold = input;
return count;
}
static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
const char *buf, size_t count)
{
unsigned int input;
unsigned int input, j;
int ret;
unsigned int j;
ret = sscanf(buf, "%u", &input);
if (ret != 1)
return -EINVAL;
@ -259,19 +229,20 @@ static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
if (input > 1)
input = 1;
if (input == dbs_tuners_ins.ignore_nice) /* nothing to do */
if (input == cs_tuners.ignore_nice) /* nothing to do */
return count;
dbs_tuners_ins.ignore_nice = input;
cs_tuners.ignore_nice = input;
/* we need to re-evaluate prev_cpu_idle */
for_each_online_cpu(j) {
struct cpu_dbs_info_s *dbs_info;
struct cs_cpu_dbs_info_s *dbs_info;
dbs_info = &per_cpu(cs_cpu_dbs_info, j);
dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
&dbs_info->prev_cpu_wall);
if (dbs_tuners_ins.ignore_nice)
dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
&dbs_info->cdbs.prev_cpu_wall);
if (cs_tuners.ignore_nice)
dbs_info->cdbs.prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
}
return count;
}
@ -289,18 +260,28 @@ static ssize_t store_freq_step(struct kobject *a, struct attribute *b,
if (input > 100)
input = 100;
/* no need to test here if freq_step is zero as the user might actually
* want this, they would be crazy though :) */
dbs_tuners_ins.freq_step = input;
/*
* no need to test here if freq_step is zero as the user might actually
* want this, they would be crazy though :)
*/
cs_tuners.freq_step = input;
return count;
}
show_one(cs, sampling_rate, sampling_rate);
show_one(cs, sampling_down_factor, sampling_down_factor);
show_one(cs, up_threshold, up_threshold);
show_one(cs, down_threshold, down_threshold);
show_one(cs, ignore_nice_load, ignore_nice);
show_one(cs, freq_step, freq_step);
define_one_global_rw(sampling_rate);
define_one_global_rw(sampling_down_factor);
define_one_global_rw(up_threshold);
define_one_global_rw(down_threshold);
define_one_global_rw(ignore_nice_load);
define_one_global_rw(freq_step);
define_one_global_ro(sampling_rate_min);
static struct attribute *dbs_attributes[] = {
&sampling_rate_min.attr,
@ -313,283 +294,38 @@ static struct attribute *dbs_attributes[] = {
NULL
};
static struct attribute_group dbs_attr_group = {
static struct attribute_group cs_attr_group = {
.attrs = dbs_attributes,
.name = "conservative",
};
/************************** sysfs end ************************/
static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
{
unsigned int load = 0;
unsigned int max_load = 0;
unsigned int freq_target;
define_get_cpu_dbs_routines(cs_cpu_dbs_info);
struct cpufreq_policy *policy;
unsigned int j;
static struct notifier_block cs_cpufreq_notifier_block = {
.notifier_call = dbs_cpufreq_notifier,
};
policy = this_dbs_info->cur_policy;
static struct cs_ops cs_ops = {
.notifier_block = &cs_cpufreq_notifier_block,
};
/*
* Every sampling_rate, we check, if current idle time is less
* than 20% (default), then we try to increase frequency
* Every sampling_rate*sampling_down_factor, we check, if current
* idle time is more than 80%, then we try to decrease frequency
*
* Any frequency increase takes it to the maximum frequency.
* Frequency reduction happens at minimum steps of
* 5% (default) of maximum frequency
*/
static struct dbs_data cs_dbs_data = {
.governor = GOV_CONSERVATIVE,
.attr_group = &cs_attr_group,
.tuners = &cs_tuners,
.get_cpu_cdbs = get_cpu_cdbs,
.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
.gov_dbs_timer = cs_dbs_timer,
.gov_check_cpu = cs_check_cpu,
.gov_ops = &cs_ops,
};
/* Get Absolute Load */
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
cputime64_t cur_wall_time, cur_idle_time;
unsigned int idle_time, wall_time;
j_dbs_info = &per_cpu(cs_cpu_dbs_info, j);
cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
wall_time = (unsigned int)
(cur_wall_time - j_dbs_info->prev_cpu_wall);
j_dbs_info->prev_cpu_wall = cur_wall_time;
idle_time = (unsigned int)
(cur_idle_time - j_dbs_info->prev_cpu_idle);
j_dbs_info->prev_cpu_idle = cur_idle_time;
if (dbs_tuners_ins.ignore_nice) {
u64 cur_nice;
unsigned long cur_nice_jiffies;
cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
j_dbs_info->prev_cpu_nice;
/*
* Assumption: nice time between sampling periods will
* be less than 2^32 jiffies for 32 bit sys
*/
cur_nice_jiffies = (unsigned long)
cputime64_to_jiffies64(cur_nice);
j_dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}
if (unlikely(!wall_time || wall_time < idle_time))
continue;
load = 100 * (wall_time - idle_time) / wall_time;
if (load > max_load)
max_load = load;
}
/*
* break out if we 'cannot' reduce the speed as the user might
* want freq_step to be zero
*/
if (dbs_tuners_ins.freq_step == 0)
return;
/* Check for frequency increase */
if (max_load > dbs_tuners_ins.up_threshold) {
this_dbs_info->down_skip = 0;
/* if we are already at full speed then break out early */
if (this_dbs_info->requested_freq == policy->max)
return;
freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100;
/* max freq cannot be less than 100. But who knows.... */
if (unlikely(freq_target == 0))
freq_target = 5;
this_dbs_info->requested_freq += freq_target;
if (this_dbs_info->requested_freq > policy->max)
this_dbs_info->requested_freq = policy->max;
__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
CPUFREQ_RELATION_H);
return;
}
/*
* The optimal frequency is the frequency that is the lowest that
* can support the current CPU usage without triggering the up
* policy. To be safe, we focus 10 points under the threshold.
*/
if (max_load < (dbs_tuners_ins.down_threshold - 10)) {
freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100;
this_dbs_info->requested_freq -= freq_target;
if (this_dbs_info->requested_freq < policy->min)
this_dbs_info->requested_freq = policy->min;
/*
* if we cannot reduce the frequency anymore, break out early
*/
if (policy->cur == policy->min)
return;
__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
CPUFREQ_RELATION_H);
return;
}
}
static void do_dbs_timer(struct work_struct *work)
{
struct cpu_dbs_info_s *dbs_info =
container_of(work, struct cpu_dbs_info_s, work.work);
unsigned int cpu = dbs_info->cpu;
/* We want all CPUs to do sampling nearly on same jiffy */
int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
delay -= jiffies % delay;
mutex_lock(&dbs_info->timer_mutex);
dbs_check_cpu(dbs_info);
schedule_delayed_work_on(cpu, &dbs_info->work, delay);
mutex_unlock(&dbs_info->timer_mutex);
}
static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info)
{
/* We want all CPUs to do sampling nearly on same jiffy */
int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
delay -= jiffies % delay;
dbs_info->enable = 1;
INIT_DEFERRABLE_WORK(&dbs_info->work, do_dbs_timer);
schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work, delay);
}
static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
{
dbs_info->enable = 0;
cancel_delayed_work_sync(&dbs_info->work);
}
static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
unsigned int event)
{
unsigned int cpu = policy->cpu;
struct cpu_dbs_info_s *this_dbs_info;
unsigned int j;
int rc;
this_dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
switch (event) {
case CPUFREQ_GOV_START:
if ((!cpu_online(cpu)) || (!policy->cur))
return -EINVAL;
mutex_lock(&dbs_mutex);
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
j_dbs_info = &per_cpu(cs_cpu_dbs_info, j);
j_dbs_info->cur_policy = policy;
j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
&j_dbs_info->prev_cpu_wall);
if (dbs_tuners_ins.ignore_nice)
j_dbs_info->prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
}
this_dbs_info->cpu = cpu;
this_dbs_info->down_skip = 0;
this_dbs_info->requested_freq = policy->cur;
mutex_init(&this_dbs_info->timer_mutex);
dbs_enable++;
/*
* Start the timerschedule work, when this governor
* is used for first time
*/
if (dbs_enable == 1) {
unsigned int latency;
/* policy latency is in nS. Convert it to uS first */
latency = policy->cpuinfo.transition_latency / 1000;
if (latency == 0)
latency = 1;
rc = sysfs_create_group(cpufreq_global_kobject,
&dbs_attr_group);
if (rc) {
mutex_unlock(&dbs_mutex);
return rc;
}
/*
* conservative does not implement micro like ondemand
* governor, thus we are bound to jiffes/HZ
*/
min_sampling_rate =
MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10);
/* Bring kernel and HW constraints together */
min_sampling_rate = max(min_sampling_rate,
MIN_LATENCY_MULTIPLIER * latency);
dbs_tuners_ins.sampling_rate =
max(min_sampling_rate,
latency * LATENCY_MULTIPLIER);
cpufreq_register_notifier(
&dbs_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
}
mutex_unlock(&dbs_mutex);
dbs_timer_init(this_dbs_info);
break;
case CPUFREQ_GOV_STOP:
dbs_timer_exit(this_dbs_info);
mutex_lock(&dbs_mutex);
dbs_enable--;
mutex_destroy(&this_dbs_info->timer_mutex);
/*
* Stop the timerschedule work, when this governor
* is used for first time
*/
if (dbs_enable == 0)
cpufreq_unregister_notifier(
&dbs_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
mutex_unlock(&dbs_mutex);
if (!dbs_enable)
sysfs_remove_group(cpufreq_global_kobject,
&dbs_attr_group);
break;
case CPUFREQ_GOV_LIMITS:
mutex_lock(&this_dbs_info->timer_mutex);
if (policy->max < this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(
this_dbs_info->cur_policy,
policy->max, CPUFREQ_RELATION_H);
else if (policy->min > this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(
this_dbs_info->cur_policy,
policy->min, CPUFREQ_RELATION_L);
dbs_check_cpu(this_dbs_info);
mutex_unlock(&this_dbs_info->timer_mutex);
break;
}
return 0;
return cpufreq_governor_dbs(&cs_dbs_data, policy, event);
}
#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
@ -597,13 +333,14 @@ static
#endif
struct cpufreq_governor cpufreq_gov_conservative = {
.name = "conservative",
.governor = cpufreq_governor_dbs,
.governor = cs_cpufreq_governor_dbs,
.max_transition_latency = TRANSITION_LATENCY_LIMIT,
.owner = THIS_MODULE,
};
static int __init cpufreq_gov_dbs_init(void)
{
mutex_init(&cs_dbs_data.mutex);
return cpufreq_register_governor(&cpufreq_gov_conservative);
}
@ -612,7 +349,6 @@ static void __exit cpufreq_gov_dbs_exit(void)
cpufreq_unregister_governor(&cpufreq_gov_conservative);
}
MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
"Low Latency Frequency Transition capable processors "

318
drivers/cpufreq/cpufreq_governor.c Normal file
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@ -0,0 +1,318 @@
/*
* drivers/cpufreq/cpufreq_governor.c
*
* CPUFREQ governors common code
*
* Copyright (C) 2001 Russell King
* (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
* (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
* (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
*
* 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 <asm/cputime.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/export.h>
#include <linux/kernel_stat.h>
#include <linux/mutex.h>
#include <linux/tick.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include "cpufreq_governor.h"
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)
{
u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
if (idle_time == -1ULL)
return get_cpu_idle_time_jiffy(cpu, wall);
else
idle_time += get_cpu_iowait_time_us(cpu, wall);
return idle_time;
}
EXPORT_SYMBOL_GPL(get_cpu_idle_time);
void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
{
struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);
struct od_dbs_tuners *od_tuners = dbs_data->tuners;
struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
struct cpufreq_policy *policy;
unsigned int max_load = 0;
unsigned int ignore_nice;
unsigned int j;
if (dbs_data->governor == GOV_ONDEMAND)
ignore_nice = od_tuners->ignore_nice;
else
ignore_nice = cs_tuners->ignore_nice;
policy = cdbs->cur_policy;
/* Get Absolute Load (in terms of freq for ondemand gov) */
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_common_info *j_cdbs;
u64 cur_wall_time, cur_idle_time, cur_iowait_time;
unsigned int idle_time, wall_time, iowait_time;
unsigned int load;
j_cdbs = dbs_data->get_cpu_cdbs(j);
cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
wall_time = (unsigned int)
(cur_wall_time - j_cdbs->prev_cpu_wall);
j_cdbs->prev_cpu_wall = cur_wall_time;
idle_time = (unsigned int)
(cur_idle_time - j_cdbs->prev_cpu_idle);
j_cdbs->prev_cpu_idle = cur_idle_time;
if (ignore_nice) {
u64 cur_nice;
unsigned long cur_nice_jiffies;
cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
cdbs->prev_cpu_nice;
/*
* Assumption: nice time between sampling periods will
* be less than 2^32 jiffies for 32 bit sys
*/
cur_nice_jiffies = (unsigned long)
cputime64_to_jiffies64(cur_nice);
cdbs->prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}
if (dbs_data->governor == GOV_ONDEMAND) {
struct od_cpu_dbs_info_s *od_j_dbs_info =
dbs_data->get_cpu_dbs_info_s(cpu);
cur_iowait_time = get_cpu_iowait_time_us(j,
&cur_wall_time);
if (cur_iowait_time == -1ULL)
cur_iowait_time = 0;
iowait_time = (unsigned int) (cur_iowait_time -
od_j_dbs_info->prev_cpu_iowait);
od_j_dbs_info->prev_cpu_iowait = cur_iowait_time;
/*
* For the purpose of ondemand, waiting for disk IO is
* an indication that you're performance critical, and
* not that the system is actually idle. So subtract the
* iowait time from the cpu idle time.
*/
if (od_tuners->io_is_busy && idle_time >= iowait_time)
idle_time -= iowait_time;
}
if (unlikely(!wall_time || wall_time < idle_time))
continue;
load = 100 * (wall_time - idle_time) / wall_time;
if (dbs_data->governor == GOV_ONDEMAND) {
int freq_avg = __cpufreq_driver_getavg(policy, j);
if (freq_avg <= 0)
freq_avg = policy->cur;
load *= freq_avg;
}
if (load > max_load)
max_load = load;
}
dbs_data->gov_check_cpu(cpu, max_load);
}
EXPORT_SYMBOL_GPL(dbs_check_cpu);
static inline void dbs_timer_init(struct dbs_data *dbs_data,
struct cpu_dbs_common_info *cdbs, unsigned int sampling_rate)
{
int delay = delay_for_sampling_rate(sampling_rate);
INIT_DEFERRABLE_WORK(&cdbs->work, dbs_data->gov_dbs_timer);
schedule_delayed_work_on(cdbs->cpu, &cdbs->work, delay);
}
static inline void dbs_timer_exit(struct cpu_dbs_common_info *cdbs)
{
cancel_delayed_work_sync(&cdbs->work);
}
int cpufreq_governor_dbs(struct dbs_data *dbs_data,
struct cpufreq_policy *policy, unsigned int event)
{
struct od_cpu_dbs_info_s *od_dbs_info = NULL;
struct cs_cpu_dbs_info_s *cs_dbs_info = NULL;
struct od_dbs_tuners *od_tuners = dbs_data->tuners;
struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
struct cpu_dbs_common_info *cpu_cdbs;
unsigned int *sampling_rate, latency, ignore_nice, j, cpu = policy->cpu;
int rc;
cpu_cdbs = dbs_data->get_cpu_cdbs(cpu);
if (dbs_data->governor == GOV_CONSERVATIVE) {
cs_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
sampling_rate = &cs_tuners->sampling_rate;
ignore_nice = cs_tuners->ignore_nice;
} else {
od_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
sampling_rate = &od_tuners->sampling_rate;
ignore_nice = od_tuners->ignore_nice;
}
switch (event) {
case CPUFREQ_GOV_START:
if ((!cpu_online(cpu)) || (!policy->cur))
return -EINVAL;
mutex_lock(&dbs_data->mutex);
dbs_data->enable++;
cpu_cdbs->cpu = cpu;
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_common_info *j_cdbs;
j_cdbs = dbs_data->get_cpu_cdbs(j);
j_cdbs->cur_policy = policy;
j_cdbs->prev_cpu_idle = get_cpu_idle_time(j,
&j_cdbs->prev_cpu_wall);
if (ignore_nice)
j_cdbs->prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
}
/*
* Start the timerschedule work, when this governor is used for
* first time
*/
if (dbs_data->enable != 1)
goto second_time;
rc = sysfs_create_group(cpufreq_global_kobject,
dbs_data->attr_group);
if (rc) {
mutex_unlock(&dbs_data->mutex);
return rc;
}
/* policy latency is in nS. Convert it to uS first */
latency = policy->cpuinfo.transition_latency / 1000;
if (latency == 0)
latency = 1;
/*
* conservative does not implement micro like ondemand
* governor, thus we are bound to jiffes/HZ
*/
if (dbs_data->governor == GOV_CONSERVATIVE) {
struct cs_ops *ops = dbs_data->gov_ops;
cpufreq_register_notifier(ops->notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
jiffies_to_usecs(10);
} else {
struct od_ops *ops = dbs_data->gov_ops;
od_tuners->io_is_busy = ops->io_busy();
}
/* Bring kernel and HW constraints together */
dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate,
MIN_LATENCY_MULTIPLIER * latency);
*sampling_rate = max(dbs_data->min_sampling_rate, latency *
LATENCY_MULTIPLIER);
second_time:
if (dbs_data->governor == GOV_CONSERVATIVE) {
cs_dbs_info->down_skip = 0;
cs_dbs_info->enable = 1;
cs_dbs_info->requested_freq = policy->cur;
} else {
struct od_ops *ops = dbs_data->gov_ops;
od_dbs_info->rate_mult = 1;
od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
ops->powersave_bias_init_cpu(cpu);
}
mutex_unlock(&dbs_data->mutex);
mutex_init(&cpu_cdbs->timer_mutex);
dbs_timer_init(dbs_data, cpu_cdbs, *sampling_rate);
break;
case CPUFREQ_GOV_STOP:
if (dbs_data->governor == GOV_CONSERVATIVE)
cs_dbs_info->enable = 0;
dbs_timer_exit(cpu_cdbs);
mutex_lock(&dbs_data->mutex);
mutex_destroy(&cpu_cdbs->timer_mutex);
dbs_data->enable--;
if (!dbs_data->enable) {
struct cs_ops *ops = dbs_data->gov_ops;
sysfs_remove_group(cpufreq_global_kobject,
dbs_data->attr_group);
if (dbs_data->governor == GOV_CONSERVATIVE)
cpufreq_unregister_notifier(ops->notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
}
mutex_unlock(&dbs_data->mutex);
break;
case CPUFREQ_GOV_LIMITS:
mutex_lock(&cpu_cdbs->timer_mutex);
if (policy->max < cpu_cdbs->cur_policy->cur)
__cpufreq_driver_target(cpu_cdbs->cur_policy,
policy->max, CPUFREQ_RELATION_H);
else if (policy->min > cpu_cdbs->cur_policy->cur)
__cpufreq_driver_target(cpu_cdbs->cur_policy,
policy->min, CPUFREQ_RELATION_L);
dbs_check_cpu(dbs_data, cpu);
mutex_unlock(&cpu_cdbs->timer_mutex);
break;
}
return 0;
}
EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);

176
drivers/cpufreq/cpufreq_governor.h Normal file
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@ -0,0 +1,176 @@
/*
* drivers/cpufreq/cpufreq_governor.h
*
* Header file for CPUFreq governors common code
*
* Copyright (C) 2001 Russell King
* (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
* (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
* (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
*
* 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.
*/
#ifndef _CPUFREQ_GOVERNER_H
#define _CPUFREQ_GOVERNER_H
#include <linux/cpufreq.h>
#include <linux/kobject.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/sysfs.h>
/*
* The polling frequency depends on the capability of the processor. Default
* polling frequency is 1000 times the transition latency of the processor. The
* governor will work on any processor with transition latency <= 10mS, using
* appropriate sampling rate.
*
* For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL)
* this governor will not work. All times here are in uS.
*/
#define MIN_SAMPLING_RATE_RATIO (2)
#define LATENCY_MULTIPLIER (1000)
#define MIN_LATENCY_MULTIPLIER (100)
#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
/* Ondemand Sampling types */
enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
/* Macro creating sysfs show routines */
#define show_one(_gov, file_name, object) \
static ssize_t show_##file_name \
(struct kobject *kobj, struct attribute *attr, char *buf) \
{ \
return sprintf(buf, "%u\n", _gov##_tuners.object); \
}
#define define_get_cpu_dbs_routines(_dbs_info) \
static struct cpu_dbs_common_info *get_cpu_cdbs(int cpu) \
{ \
return &per_cpu(_dbs_info, cpu).cdbs; \
} \
\
static void *get_cpu_dbs_info_s(int cpu) \
{ \
return &per_cpu(_dbs_info, cpu); \
}
/*
* Abbreviations:
* dbs: used as a shortform for demand based switching It helps to keep variable
* names smaller, simpler
* cdbs: common dbs
* on_*: On-demand governor
* cs_*: Conservative governor
*/
/* Per cpu structures */
struct cpu_dbs_common_info {
int cpu;
u64 prev_cpu_idle;
u64 prev_cpu_wall;
u64 prev_cpu_nice;
struct cpufreq_policy *cur_policy;
struct delayed_work work;
/*
* percpu mutex that serializes governor limit change with gov_dbs_timer
* invocation. We do not want gov_dbs_timer to run when user is changing
* the governor or limits.
*/
struct mutex timer_mutex;
};
struct od_cpu_dbs_info_s {
struct cpu_dbs_common_info cdbs;
u64 prev_cpu_iowait;
struct cpufreq_frequency_table *freq_table;
unsigned int freq_lo;
unsigned int freq_lo_jiffies;
unsigned int freq_hi_jiffies;
unsigned int rate_mult;
unsigned int sample_type:1;
};
struct cs_cpu_dbs_info_s {
struct cpu_dbs_common_info cdbs;
unsigned int down_skip;
unsigned int requested_freq;
unsigned int enable:1;
};
/* Governers sysfs tunables */
struct od_dbs_tuners {
unsigned int ignore_nice;
unsigned int sampling_rate;
unsigned int sampling_down_factor;
unsigned int up_threshold;
unsigned int down_differential;
unsigned int powersave_bias;
unsigned int io_is_busy;
};
struct cs_dbs_tuners {
unsigned int ignore_nice;
unsigned int sampling_rate;
unsigned int sampling_down_factor;
unsigned int up_threshold;
unsigned int down_threshold;
unsigned int freq_step;
};
/* Per Governer data */
struct dbs_data {
/* Common across governors */
#define GOV_ONDEMAND 0
#define GOV_CONSERVATIVE 1
int governor;
unsigned int min_sampling_rate;
unsigned int enable; /* number of CPUs using this policy */
struct attribute_group *attr_group;
void *tuners;
/* dbs_mutex protects dbs_enable in governor start/stop */
struct mutex mutex;
struct cpu_dbs_common_info *(*get_cpu_cdbs)(int cpu);
void *(*get_cpu_dbs_info_s)(int cpu);
void (*gov_dbs_timer)(struct work_struct *work);
void (*gov_check_cpu)(int cpu, unsigned int load);
/* Governor specific ops, see below */
void *gov_ops;
};
/* Governor specific ops, will be passed to dbs_data->gov_ops */
struct od_ops {
int (*io_busy)(void);
void (*powersave_bias_init_cpu)(int cpu);
unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
unsigned int freq_next, unsigned int relation);
void (*freq_increase)(struct cpufreq_policy *p, unsigned int freq);
};
struct cs_ops {
struct notifier_block *notifier_block;
};
static inline int delay_for_sampling_rate(unsigned int sampling_rate)
{
int delay = usecs_to_jiffies(sampling_rate);
/* We want all CPUs to do sampling nearly on same jiffy */
if (num_online_cpus() > 1)
delay -= jiffies % delay;
return delay;
}
u64 get_cpu_idle_time(unsigned int cpu, u64 *wall);
void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
int cpufreq_governor_dbs(struct dbs_data *dbs_data,
struct cpufreq_policy *policy, unsigned int event);
#endif /* _CPUFREQ_GOVERNER_H */

737
drivers/cpufreq/cpufreq_ondemand.c
View File

@ -10,24 +10,23 @@
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cpufreq.h>
#include <linux/cpu.h>
#include <linux/jiffies.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/hrtimer.h>
#include <linux/percpu-defs.h>
#include <linux/sysfs.h>
#include <linux/tick.h>
#include <linux/ktime.h>
#include <linux/sched.h>
#include <linux/types.h>
/*
* dbs is used in this file as a shortform for demandbased switching
* It helps to keep variable names smaller, simpler
*/
#include "cpufreq_governor.h"
/* On-demand governor macors */
#define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10)
#define DEF_FREQUENCY_UP_THRESHOLD (80)
#define DEF_SAMPLING_DOWN_FACTOR (1)
@ -38,80 +37,14 @@
#define MIN_FREQUENCY_UP_THRESHOLD (11)
#define MAX_FREQUENCY_UP_THRESHOLD (100)
/*
* The polling frequency of this governor depends on the capability of
* the processor. Default polling frequency is 1000 times the transition
* latency of the processor. The governor will work on any processor with
* transition latency <= 10mS, using appropriate sampling
* rate.
* For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL)
* this governor will not work.
* All times here are in uS.
*/
#define MIN_SAMPLING_RATE_RATIO (2)
static unsigned int min_sampling_rate;
#define LATENCY_MULTIPLIER (1000)
#define MIN_LATENCY_MULTIPLIER (100)
#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
static void do_dbs_timer(struct work_struct *work);
static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
unsigned int event);
static struct dbs_data od_dbs_data;
static DEFINE_PER_CPU(struct od_cpu_dbs_info_s, od_cpu_dbs_info);
#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
static
static struct cpufreq_governor cpufreq_gov_ondemand;
#endif
struct cpufreq_governor cpufreq_gov_ondemand = {
.name = "ondemand",
.governor = cpufreq_governor_dbs,
.max_transition_latency = TRANSITION_LATENCY_LIMIT,
.owner = THIS_MODULE,
};
/* Sampling types */
enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE};
struct cpu_dbs_info_s {
cputime64_t prev_cpu_idle;
cputime64_t prev_cpu_iowait;
cputime64_t prev_cpu_wall;
cputime64_t prev_cpu_nice;
struct cpufreq_policy *cur_policy;
struct delayed_work work;
struct cpufreq_frequency_table *freq_table;
unsigned int freq_lo;
unsigned int freq_lo_jiffies;
unsigned int freq_hi_jiffies;
unsigned int rate_mult;
int cpu;
unsigned int sample_type:1;
/*
* percpu mutex that serializes governor limit change with
* do_dbs_timer invocation. We do not want do_dbs_timer to run
* when user is changing the governor or limits.
*/
struct mutex timer_mutex;
};
static DEFINE_PER_CPU(struct cpu_dbs_info_s, od_cpu_dbs_info);
static unsigned int dbs_enable; /* number of CPUs using this policy */
/*
* dbs_mutex protects dbs_enable in governor start/stop.
*/
static DEFINE_MUTEX(dbs_mutex);
static struct dbs_tuners {
unsigned int sampling_rate;
unsigned int up_threshold;
unsigned int down_differential;
unsigned int ignore_nice;
unsigned int sampling_down_factor;
unsigned int powersave_bias;
unsigned int io_is_busy;
} dbs_tuners_ins = {
static struct od_dbs_tuners od_tuners = {
.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
.sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
.down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL,
@ -119,48 +52,35 @@ static struct dbs_tuners {
.powersave_bias = 0,
};
static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
static void ondemand_powersave_bias_init_cpu(int cpu)
{
u64 idle_time;
u64 cur_wall_time;
u64 busy_time;
struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
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 = jiffies_to_usecs(cur_wall_time);
return jiffies_to_usecs(idle_time);
dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
dbs_info->freq_lo = 0;
}
static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
/*
* Not all CPUs want IO time to be accounted as busy; this depends on how
* efficient idling at a higher frequency/voltage is.
* Pavel Machek says this is not so for various generations of AMD and old
* Intel systems.
* Mike Chan (androidlcom) calis this is also not true for ARM.
* Because of this, whitelist specific known (series) of CPUs by default, and
* leave all others up to the user.
*/
static int should_io_be_busy(void)
{
u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
if (idle_time == -1ULL)
return get_cpu_idle_time_jiffy(cpu, wall);
else
idle_time += get_cpu_iowait_time_us(cpu, wall);
return idle_time;
}
static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall)
{
u64 iowait_time = get_cpu_iowait_time_us(cpu, wall);
if (iowait_time == -1ULL)
return 0;
return iowait_time;
#if defined(CONFIG_X86)
/*
* For Intel, Core 2 (model 15) andl later have an efficient idle.
*/
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
boot_cpu_data.x86 == 6 &&
boot_cpu_data.x86_model >= 15)
return 1;
#endif
return 0;
}
/*
@ -169,14 +89,13 @@ static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wal
* freq_lo, and freq_lo_jiffies in percpu area for averaging freqs.
*/
static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
unsigned int freq_next,
unsigned int relation)
unsigned int freq_next, unsigned int relation)
{
unsigned int freq_req, freq_reduc, freq_avg;
unsigned int freq_hi, freq_lo;
unsigned int index = 0;
unsigned int jiffies_total, jiffies_hi, jiffies_lo;
struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
policy->cpu);
if (!dbs_info->freq_table) {
@ -188,7 +107,7 @@ static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next,
relation, &index);
freq_req = dbs_info->freq_table[index].frequency;
freq_reduc = freq_req * dbs_tuners_ins.powersave_bias / 1000;
freq_reduc = freq_req * od_tuners.powersave_bias / 1000;
freq_avg = freq_req - freq_reduc;
/* Find freq bounds for freq_avg in freq_table */
@ -207,7 +126,7 @@ static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
dbs_info->freq_lo_jiffies = 0;
return freq_lo;
}
jiffies_total = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
jiffies_total = usecs_to_jiffies(od_tuners.sampling_rate);
jiffies_hi = (freq_avg - freq_lo) * jiffies_total;
jiffies_hi += ((freq_hi - freq_lo) / 2);
jiffies_hi /= (freq_hi - freq_lo);
@ -218,13 +137,6 @@ static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
return freq_hi;
}
static void ondemand_powersave_bias_init_cpu(int cpu)
{
struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
dbs_info->freq_lo = 0;
}
static void ondemand_powersave_bias_init(void)
{
int i;
@ -233,83 +145,173 @@ static void ondemand_powersave_bias_init(void)
}
}
static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq)
{
if (od_tuners.powersave_bias)
freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H);
else if (p->cur == p->max)
return;
__cpufreq_driver_target(p, freq, od_tuners.powersave_bias ?
CPUFREQ_RELATION_L : CPUFREQ_RELATION_H);
}
/*
* Every sampling_rate, we check, if current idle time is less than 20%
* (default), then we try to increase frequency Every sampling_rate, we look for
* a the lowest frequency which can sustain the load while keeping idle time
* over 30%. If such a frequency exist, we try to decrease to this frequency.
*
* Any frequency increase takes it to the maximum frequency. Frequency reduction
* happens at minimum steps of 5% (default) of current frequency
*/
static void od_check_cpu(int cpu, unsigned int load_freq)
{
struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
dbs_info->freq_lo = 0;
/* Check for frequency increase */
if (load_freq > od_tuners.up_threshold * policy->cur) {
/* If switching to max speed, apply sampling_down_factor */
if (policy->cur < policy->max)
dbs_info->rate_mult =
od_tuners.sampling_down_factor;
dbs_freq_increase(policy, policy->max);
return;
}
/* Check for frequency decrease */
/* if we cannot reduce the frequency anymore, break out early */
if (policy->cur == policy->min)
return;
/*
* The optimal frequency is the frequency that is the lowest that can
* support the current CPU usage without triggering the up policy. To be
* safe, we focus 10 points under the threshold.
*/
if (load_freq < (od_tuners.up_threshold - od_tuners.down_differential) *
policy->cur) {
unsigned int freq_next;
freq_next = load_freq / (od_tuners.up_threshold -
od_tuners.down_differential);
/* No longer fully busy, reset rate_mult */
dbs_info->rate_mult = 1;
if (freq_next < policy->min)
freq_next = policy->min;
if (!od_tuners.powersave_bias) {
__cpufreq_driver_target(policy, freq_next,
CPUFREQ_RELATION_L);
} else {
int freq = powersave_bias_target(policy, freq_next,
CPUFREQ_RELATION_L);
__cpufreq_driver_target(policy, freq,
CPUFREQ_RELATION_L);
}
}
}
static void od_dbs_timer(struct work_struct *work)
{
struct od_cpu_dbs_info_s *dbs_info =
container_of(work, struct od_cpu_dbs_info_s, cdbs.work.work);
unsigned int cpu = dbs_info->cdbs.cpu;
int delay, sample_type = dbs_info->sample_type;
mutex_lock(&dbs_info->cdbs.timer_mutex);
/* Common NORMAL_SAMPLE setup */
dbs_info->sample_type = OD_NORMAL_SAMPLE;
if (sample_type == OD_SUB_SAMPLE) {
delay = dbs_info->freq_lo_jiffies;
__cpufreq_driver_target(dbs_info->cdbs.cur_policy,
dbs_info->freq_lo, CPUFREQ_RELATION_H);
} else {
dbs_check_cpu(&od_dbs_data, cpu);
if (dbs_info->freq_lo) {
/* Setup timer for SUB_SAMPLE */
dbs_info->sample_type = OD_SUB_SAMPLE;
delay = dbs_info->freq_hi_jiffies;
} else {
delay = delay_for_sampling_rate(od_tuners.sampling_rate
* dbs_info->rate_mult);
}
}
schedule_delayed_work_on(cpu, &dbs_info->cdbs.work, delay);
mutex_unlock(&dbs_info->cdbs.timer_mutex);
}
/************************** sysfs interface ************************/
static ssize_t show_sampling_rate_min(struct kobject *kobj,
struct attribute *attr, char *buf)
{
return sprintf(buf, "%u\n", min_sampling_rate);
return sprintf(buf, "%u\n", od_dbs_data.min_sampling_rate);
}
define_one_global_ro(sampling_rate_min);
/* cpufreq_ondemand Governor Tunables */
#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", dbs_tuners_ins.object); \
}
show_one(sampling_rate, sampling_rate);
show_one(io_is_busy, io_is_busy);
show_one(up_threshold, up_threshold);
show_one(sampling_down_factor, sampling_down_factor);
show_one(ignore_nice_load, ignore_nice);
show_one(powersave_bias, powersave_bias);
/**
* update_sampling_rate - update sampling rate effective immediately if needed.
* @new_rate: new sampling rate
*
* If new rate is smaller than the old, simply updaing
* dbs_tuners_int.sampling_rate might not be appropriate. For example,
* if the original sampling_rate was 1 second and the requested new sampling
* rate is 10 ms because the user needs immediate reaction from ondemand
* governor, but not sure if higher frequency will be required or not,
* then, the governor may change the sampling rate too late; up to 1 second
* later. Thus, if we are reducing the sampling rate, we need to make the
* new value effective immediately.
* dbs_tuners_int.sampling_rate might not be appropriate. For example, if the
* original sampling_rate was 1 second and the requested new sampling rate is 10
* ms because the user needs immediate reaction from ondemand governor, but not
* sure if higher frequency will be required or not, then, the governor may
* change the sampling rate too late; up to 1 second later. Thus, if we are
* reducing the sampling rate, we need to make the new value effective
* immediately.
*/
static void update_sampling_rate(unsigned int new_rate)
{
int cpu;
dbs_tuners_ins.sampling_rate = new_rate
= max(new_rate, min_sampling_rate);
od_tuners.sampling_rate = new_rate = max(new_rate,
od_dbs_data.min_sampling_rate);
for_each_online_cpu(cpu) {
struct cpufreq_policy *policy;
struct cpu_dbs_info_s *dbs_info;
struct od_cpu_dbs_info_s *dbs_info;
unsigned long next_sampling, appointed_at;
policy = cpufreq_cpu_get(cpu);
if (!policy)
continue;
if (policy->governor != &cpufreq_gov_ondemand) {
cpufreq_cpu_put(policy);
continue;
}
dbs_info = &per_cpu(od_cpu_dbs_info, policy->cpu);
cpufreq_cpu_put(policy);
mutex_lock(&dbs_info->timer_mutex);
mutex_lock(&dbs_info->cdbs.timer_mutex);
if (!delayed_work_pending(&dbs_info->work)) {
mutex_unlock(&dbs_info->timer_mutex);
if (!delayed_work_pending(&dbs_info->cdbs.work)) {
mutex_unlock(&dbs_info->cdbs.timer_mutex);
continue;
}
next_sampling = jiffies + usecs_to_jiffies(new_rate);
appointed_at = dbs_info->work.timer.expires;
next_sampling = jiffies + usecs_to_jiffies(new_rate);
appointed_at = dbs_info->cdbs.work.timer.expires;
if (time_before(next_sampling, appointed_at)) {
mutex_unlock(&dbs_info->timer_mutex);
cancel_delayed_work_sync(&dbs_info->work);
mutex_lock(&dbs_info->timer_mutex);
mutex_unlock(&dbs_info->cdbs.timer_mutex);
cancel_delayed_work_sync(&dbs_info->cdbs.work);
mutex_lock(&dbs_info->cdbs.timer_mutex);
schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work,
usecs_to_jiffies(new_rate));
schedule_delayed_work_on(dbs_info->cdbs.cpu,
&dbs_info->cdbs.work,
usecs_to_jiffies(new_rate));
}
mutex_unlock(&dbs_info->timer_mutex);
mutex_unlock(&dbs_info->cdbs.timer_mutex);
}
}
@ -334,7 +336,7 @@ static ssize_t store_io_is_busy(struct kobject *a, struct attribute *b,
ret = sscanf(buf, "%u", &input);
if (ret != 1)
return -EINVAL;
dbs_tuners_ins.io_is_busy = !!input;
od_tuners.io_is_busy = !!input;
return count;
}
@ -349,7 +351,7 @@ static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
input < MIN_FREQUENCY_UP_THRESHOLD) {
return -EINVAL;
}
dbs_tuners_ins.up_threshold = input;
od_tuners.up_threshold = input;
return count;
}
@ -362,12 +364,12 @@ static ssize_t store_sampling_down_factor(struct kobject *a,
if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
return -EINVAL;
dbs_tuners_ins.sampling_down_factor = input;
od_tuners.sampling_down_factor = input;
/* Reset down sampling multiplier in case it was active */
for_each_online_cpu(j) {
struct cpu_dbs_info_s *dbs_info;
dbs_info = &per_cpu(od_cpu_dbs_info, j);
struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
j);
dbs_info->rate_mult = 1;
}
return count;
@ -388,19 +390,20 @@ static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
if (input > 1)
input = 1;
if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */
if (input == od_tuners.ignore_nice) { /* nothing to do */
return count;
}
dbs_tuners_ins.ignore_nice = input;
od_tuners.ignore_nice = input;
/* we need to re-evaluate prev_cpu_idle */
for_each_online_cpu(j) {
struct cpu_dbs_info_s *dbs_info;
struct od_cpu_dbs_info_s *dbs_info;
dbs_info = &per_cpu(od_cpu_dbs_info, j);
dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
&dbs_info->prev_cpu_wall);
if (dbs_tuners_ins.ignore_nice)
dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
&dbs_info->cdbs.prev_cpu_wall);
if (od_tuners.ignore_nice)
dbs_info->cdbs.prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
}
return count;
@ -419,17 +422,25 @@ static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b,
if (input > 1000)
input = 1000;
dbs_tuners_ins.powersave_bias = input;
od_tuners.powersave_bias = input;
ondemand_powersave_bias_init();
return count;
}
show_one(od, sampling_rate, sampling_rate);
show_one(od, io_is_busy, io_is_busy);
show_one(od, up_threshold, up_threshold);
show_one(od, sampling_down_factor, sampling_down_factor);
show_one(od, ignore_nice_load, ignore_nice);
show_one(od, powersave_bias, powersave_bias);
define_one_global_rw(sampling_rate);
define_one_global_rw(io_is_busy);
define_one_global_rw(up_threshold);
define_one_global_rw(sampling_down_factor);
define_one_global_rw(ignore_nice_load);
define_one_global_rw(powersave_bias);
define_one_global_ro(sampling_rate_min);
static struct attribute *dbs_attributes[] = {
&sampling_rate_min.attr,
@ -442,354 +453,71 @@ static struct attribute *dbs_attributes[] = {
NULL
};
static struct attribute_group dbs_attr_group = {
static struct attribute_group od_attr_group = {
.attrs = dbs_attributes,
.name = "ondemand",
};
/************************** sysfs end ************************/
static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq)
{
if (dbs_tuners_ins.powersave_bias)
freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H);
else if (p->cur == p->max)
return;
define_get_cpu_dbs_routines(od_cpu_dbs_info);
__cpufreq_driver_target(p, freq, dbs_tuners_ins.powersave_bias ?
CPUFREQ_RELATION_L : CPUFREQ_RELATION_H);
static struct od_ops od_ops = {
.io_busy = should_io_be_busy,
.powersave_bias_init_cpu = ondemand_powersave_bias_init_cpu,
.powersave_bias_target = powersave_bias_target,
.freq_increase = dbs_freq_increase,
};
static struct dbs_data od_dbs_data = {
.governor = GOV_ONDEMAND,
.attr_group = &od_attr_group,
.tuners = &od_tuners,
.get_cpu_cdbs = get_cpu_cdbs,
.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
.gov_dbs_timer = od_dbs_timer,
.gov_check_cpu = od_check_cpu,
.gov_ops = &od_ops,
};
static int od_cpufreq_governor_dbs(struct cpufreq_policy *policy,
unsigned int event)
{
return cpufreq_governor_dbs(&od_dbs_data, policy, event);
}
static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
{
unsigned int max_load_freq;
struct cpufreq_policy *policy;
unsigned int j;
this_dbs_info->freq_lo = 0;
policy = this_dbs_info->cur_policy;
/*
* Every sampling_rate, we check, if current idle time is less
* than 20% (default), then we try to increase frequency
* Every sampling_rate, we look for a the lowest
* frequency which can sustain the load while keeping idle time over
* 30%. If such a frequency exist, we try to decrease to this frequency.
*
* Any frequency increase takes it to the maximum frequency.
* Frequency reduction happens at minimum steps of
* 5% (default) of current frequency
*/
/* Get Absolute Load - in terms of freq */
max_load_freq = 0;
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time;
unsigned int idle_time, wall_time, iowait_time;
unsigned int load, load_freq;
int freq_avg;
j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time);
wall_time = (unsigned int)
(cur_wall_time - j_dbs_info->prev_cpu_wall);
j_dbs_info->prev_cpu_wall = cur_wall_time;
idle_time = (unsigned int)
(cur_idle_time - j_dbs_info->prev_cpu_idle);
j_dbs_info->prev_cpu_idle = cur_idle_time;
iowait_time = (unsigned int)
(cur_iowait_time - j_dbs_info->prev_cpu_iowait);
j_dbs_info->prev_cpu_iowait = cur_iowait_time;
if (dbs_tuners_ins.ignore_nice) {
u64 cur_nice;
unsigned long cur_nice_jiffies;
cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
j_dbs_info->prev_cpu_nice;
/*
* Assumption: nice time between sampling periods will
* be less than 2^32 jiffies for 32 bit sys
*/
cur_nice_jiffies = (unsigned long)
cputime64_to_jiffies64(cur_nice);
j_dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}
/*
* For the purpose of ondemand, waiting for disk IO is an
* indication that you're performance critical, and not that
* the system is actually idle. So subtract the iowait time
* from the cpu idle time.
*/
if (dbs_tuners_ins.io_is_busy && idle_time >= iowait_time)
idle_time -= iowait_time;
if (unlikely(!wall_time || wall_time < idle_time))
continue;
load = 100 * (wall_time - idle_time) / wall_time;
freq_avg = __cpufreq_driver_getavg(policy, j);
if (freq_avg <= 0)
freq_avg = policy->cur;
load_freq = load * freq_avg;
if (load_freq > max_load_freq)
max_load_freq = load_freq;
}
/* Check for frequency increase */
if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) {
/* If switching to max speed, apply sampling_down_factor */
if (policy->cur < policy->max)
this_dbs_info->rate_mult =
dbs_tuners_ins.sampling_down_factor;
dbs_freq_increase(policy, policy->max);
return;
}
/* Check for frequency decrease */
/* if we cannot reduce the frequency anymore, break out early */
if (policy->cur == policy->min)
return;
/*
* The optimal frequency is the frequency that is the lowest that
* can support the current CPU usage without triggering the up
* policy. To be safe, we focus 10 points under the threshold.
*/
if (max_load_freq <
(dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) *
policy->cur) {
unsigned int freq_next;
freq_next = max_load_freq /
(dbs_tuners_ins.up_threshold -
dbs_tuners_ins.down_differential);
/* No longer fully busy, reset rate_mult */
this_dbs_info->rate_mult = 1;
if (freq_next < policy->min)
freq_next = policy->min;
if (!dbs_tuners_ins.powersave_bias) {
__cpufreq_driver_target(policy, freq_next,
CPUFREQ_RELATION_L);
} else {
int freq = powersave_bias_target(policy, freq_next,
CPUFREQ_RELATION_L);
__cpufreq_driver_target(policy, freq,
CPUFREQ_RELATION_L);
}
}
}
static void do_dbs_timer(struct work_struct *work)
{
struct cpu_dbs_info_s *dbs_info =
container_of(work, struct cpu_dbs_info_s, work.work);
unsigned int cpu = dbs_info->cpu;
int sample_type = dbs_info->sample_type;
int delay;
mutex_lock(&dbs_info->timer_mutex);
/* Common NORMAL_SAMPLE setup */
dbs_info->sample_type = DBS_NORMAL_SAMPLE;
if (!dbs_tuners_ins.powersave_bias ||
sample_type == DBS_NORMAL_SAMPLE) {
dbs_check_cpu(dbs_info);
if (dbs_info->freq_lo) {
/* Setup timer for SUB_SAMPLE */
dbs_info->sample_type = DBS_SUB_SAMPLE;
delay = dbs_info->freq_hi_jiffies;
} else {
/* We want all CPUs to do sampling nearly on
* same jiffy
*/
delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate
* dbs_info->rate_mult);
if (num_online_cpus() > 1)
delay -= jiffies % delay;
}
} else {
__cpufreq_driver_target(dbs_info->cur_policy,
dbs_info->freq_lo, CPUFREQ_RELATION_H);
delay = dbs_info->freq_lo_jiffies;
}
schedule_delayed_work_on(cpu, &dbs_info->work, delay);
mutex_unlock(&dbs_info->timer_mutex);
}
static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info)
{
/* We want all CPUs to do sampling nearly on same jiffy */
int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
if (num_online_cpus() > 1)
delay -= jiffies % delay;
dbs_info->sample_type = DBS_NORMAL_SAMPLE;
INIT_DEFERRABLE_WORK(&dbs_info->work, do_dbs_timer);
schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work, delay);
}
static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
{
cancel_delayed_work_sync(&dbs_info->work);
}
/*
* Not all CPUs want IO time to be accounted as busy; this dependson how
* efficient idling at a higher frequency/voltage is.
* Pavel Machek says this is not so for various generations of AMD and old
* Intel systems.
* Mike Chan (androidlcom) calis this is also not true for ARM.
* Because of this, whitelist specific known (series) of CPUs by default, and
* leave all others up to the user.
*/
static int should_io_be_busy(void)
{
#if defined(CONFIG_X86)
/*
* For Intel, Core 2 (model 15) andl later have an efficient idle.
*/
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
boot_cpu_data.x86 == 6 &&
boot_cpu_data.x86_model >= 15)
return 1;
#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
static
#endif
return 0;
}
static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
unsigned int event)
{
unsigned int cpu = policy->cpu;
struct cpu_dbs_info_s *this_dbs_info;
unsigned int j;
int rc;
this_dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
switch (event) {
case CPUFREQ_GOV_START:
if ((!cpu_online(cpu)) || (!policy->cur))
return -EINVAL;
mutex_lock(&dbs_mutex);
dbs_enable++;
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
j_dbs_info->cur_policy = policy;
j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
&j_dbs_info->prev_cpu_wall);
if (dbs_tuners_ins.ignore_nice)
j_dbs_info->prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
}
this_dbs_info->cpu = cpu;
this_dbs_info->rate_mult = 1;
ondemand_powersave_bias_init_cpu(cpu);
/*
* Start the timerschedule work, when this governor
* is used for first time
*/
if (dbs_enable == 1) {
unsigned int latency;
rc = sysfs_create_group(cpufreq_global_kobject,
&dbs_attr_group);
if (rc) {
mutex_unlock(&dbs_mutex);
return rc;
}
/* policy latency is in nS. Convert it to uS first */
latency = policy->cpuinfo.transition_latency / 1000;
if (latency == 0)
latency = 1;
/* Bring kernel and HW constraints together */
min_sampling_rate = max(min_sampling_rate,
MIN_LATENCY_MULTIPLIER * latency);
dbs_tuners_ins.sampling_rate =
max(min_sampling_rate,
latency * LATENCY_MULTIPLIER);
dbs_tuners_ins.io_is_busy = should_io_be_busy();
}
mutex_unlock(&dbs_mutex);
mutex_init(&this_dbs_info->timer_mutex);
dbs_timer_init(this_dbs_info);
break;
case CPUFREQ_GOV_STOP:
dbs_timer_exit(this_dbs_info);
mutex_lock(&dbs_mutex);
mutex_destroy(&this_dbs_info->timer_mutex);
dbs_enable--;
mutex_unlock(&dbs_mutex);
if (!dbs_enable)
sysfs_remove_group(cpufreq_global_kobject,
&dbs_attr_group);
break;
case CPUFREQ_GOV_LIMITS:
mutex_lock(&this_dbs_info->timer_mutex);
if (policy->max < this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(this_dbs_info->cur_policy,
policy->max, CPUFREQ_RELATION_H);
else if (policy->min > this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(this_dbs_info->cur_policy,
policy->min, CPUFREQ_RELATION_L);
dbs_check_cpu(this_dbs_info);
mutex_unlock(&this_dbs_info->timer_mutex);
break;
}
return 0;
}
struct cpufreq_governor cpufreq_gov_ondemand = {
.name = "ondemand",
.governor = od_cpufreq_governor_dbs,
.max_transition_latency = TRANSITION_LATENCY_LIMIT,
.owner = THIS_MODULE,
};
static int __init cpufreq_gov_dbs_init(void)
{
u64 idle_time;
int cpu = get_cpu();
mutex_init(&od_dbs_data.mutex);
idle_time = get_cpu_idle_time_us(cpu, NULL);
put_cpu();
if (idle_time != -1ULL) {
/* Idle micro accounting is supported. Use finer thresholds */
dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
dbs_tuners_ins.down_differential =
MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
od_tuners.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
od_tuners.down_differential = MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
/*
* In nohz/micro accounting case we set the minimum frequency
* not depending on HZ, but fixed (very low). The deferred
* timer might skip some samples if idle/sleeping as needed.
*/
min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE;
od_dbs_data.min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE;
} else {
/* For correct statistics, we need 10 ticks for each measure */
min_sampling_rate =
MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10);
od_dbs_data.min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
jiffies_to_usecs(10);
}
return cpufreq_register_governor(&cpufreq_gov_ondemand);
@ -800,7 +528,6 @@ static void __exit cpufreq_gov_dbs_exit(void)
cpufreq_unregister_governor(&cpufreq_gov_ondemand);
}
MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>");
MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>");
MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for "

2
drivers/cpufreq/cpufreq_performance.c
View File

@ -10,6 +10,8 @@
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cpufreq.h>

2
drivers/cpufreq/cpufreq_powersave.c
View File

@ -10,6 +10,8 @@
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cpufreq.h>

4
drivers/cpufreq/cpufreq_stats.c
View File

@ -37,7 +37,7 @@ struct cpufreq_stats {
unsigned int max_state;
unsigned int state_num;
unsigned int last_index;
cputime64_t *time_in_state;
u64 *time_in_state;
unsigned int *freq_table;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
unsigned int *trans_table;
@ -223,7 +223,7 @@ static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
count++;
}
alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
alloc_size = count * sizeof(int) + count * sizeof(u64);
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
alloc_size += count * count * sizeof(int);

2
drivers/cpufreq/cpufreq_userspace.c
View File

@ -11,6 +11,8 @@
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/smp.h>

11
drivers/cpufreq/exynos-cpufreq.c
View File

@ -31,13 +31,13 @@ static unsigned int locking_frequency;
static bool frequency_locked;
static DEFINE_MUTEX(cpufreq_lock);
int exynos_verify_speed(struct cpufreq_policy *policy)
static int exynos_verify_speed(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy,
exynos_info->freq_table);
}
unsigned int exynos_getspeed(unsigned int cpu)
static unsigned int exynos_getspeed(unsigned int cpu)
{
return clk_get_rate(exynos_info->cpu_clk) / 1000;
}
@ -100,7 +100,8 @@ static int exynos_target(struct cpufreq_policy *policy,
}
arm_volt = volt_table[index];
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
for_each_cpu(freqs.cpu, policy->cpus)
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
/* When the new frequency is higher than current frequency */
if ((freqs.new > freqs.old) && !safe_arm_volt) {
@ -115,7 +116,8 @@ static int exynos_target(struct cpufreq_policy *policy,
if (freqs.new != freqs.old)
exynos_info->set_freq(old_index, index);
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
for_each_cpu(freqs.cpu, policy->cpus)
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
/* When the new frequency is lower than current frequency */
if ((freqs.new < freqs.old) ||
@ -235,6 +237,7 @@ static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
cpumask_copy(policy->related_cpus, cpu_possible_mask);
cpumask_copy(policy->cpus, cpu_online_mask);
} else {
policy->shared_type = CPUFREQ_SHARED_TYPE_ANY;
cpumask_setall(policy->cpus);
}

2
drivers/cpufreq/freq_table.c
View File

@ -9,6 +9,8 @@
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>

4
drivers/cpufreq/longhaul.c
View File

@ -930,7 +930,7 @@ static int __cpuinit longhaul_cpu_init(struct cpufreq_policy *policy)
return 0;
}
static int __devexit longhaul_cpu_exit(struct cpufreq_policy *policy)
static int longhaul_cpu_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_put_attr(policy->cpu);
return 0;
@ -946,7 +946,7 @@ static struct cpufreq_driver longhaul_driver = {
.target = longhaul_target,
.get = longhaul_get,
.init = longhaul_cpu_init,
.exit = __devexit_p(longhaul_cpu_exit),
.exit = longhaul_cpu_exit,
.name = "longhaul",
.owner = THIS_MODULE,
.attr = longhaul_attr,

4
drivers/cpufreq/powernow-k8.c
View File

@ -1186,7 +1186,7 @@ err_out:
return -ENODEV;
}
static int __devexit powernowk8_cpu_exit(struct cpufreq_policy *pol)
static int powernowk8_cpu_exit(struct cpufreq_policy *pol)
{
struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
@ -1242,7 +1242,7 @@ static struct cpufreq_driver cpufreq_amd64_driver = {
.target = powernowk8_target,
.bios_limit = acpi_processor_get_bios_limit,
.init = powernowk8_cpu_init,
.exit = __devexit_p(powernowk8_cpu_exit),
.exit = powernowk8_cpu_exit,
.get = powernowk8_get,
.name = "powernow-k8",
.owner = THIS_MODULE,

291
drivers/cpufreq/spear-cpufreq.c Normal file
View File

@ -0,0 +1,291 @@
/*
* drivers/cpufreq/spear-cpufreq.c
*
* CPU Frequency Scaling for SPEAr platform
*
* Copyright (C) 2012 ST Microelectronics
* Deepak Sikri <deepak.sikri@st.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/types.h>
/* SPEAr CPUFreq driver data structure */
static struct {
struct clk *clk;
unsigned int transition_latency;
struct cpufreq_frequency_table *freq_tbl;
u32 cnt;
} spear_cpufreq;
int spear_cpufreq_verify(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy, spear_cpufreq.freq_tbl);
}
static unsigned int spear_cpufreq_get(unsigned int cpu)
{
return clk_get_rate(spear_cpufreq.clk) / 1000;
}
static struct clk *spear1340_cpu_get_possible_parent(unsigned long newfreq)
{
struct clk *sys_pclk;
int pclk;
/*
* In SPEAr1340, cpu clk's parent sys clk can take input from
* following sources
*/
const char *sys_clk_src[] = {
"sys_syn_clk",
"pll1_clk",
"pll2_clk",
"pll3_clk",
};
/*
* As sys clk can have multiple source with their own range
* limitation so we choose possible sources accordingly
*/
if (newfreq <= 300000000)
pclk = 0; /* src is sys_syn_clk */
else if (newfreq > 300000000 && newfreq <= 500000000)
pclk = 3; /* src is pll3_clk */
else if (newfreq == 600000000)
pclk = 1; /* src is pll1_clk */
else
return ERR_PTR(-EINVAL);
/* Get parent to sys clock */
sys_pclk = clk_get(NULL, sys_clk_src[pclk]);
if (IS_ERR(sys_pclk))
pr_err("Failed to get %s clock\n", sys_clk_src[pclk]);
return sys_pclk;
}
/*
* In SPEAr1340, we cannot use newfreq directly because we need to actually
* access a source clock (clk) which might not be ancestor of cpu at present.
* Hence in SPEAr1340 we would operate on source clock directly before switching
* cpu clock to it.
*/
static int spear1340_set_cpu_rate(struct clk *sys_pclk, unsigned long newfreq)
{
struct clk *sys_clk;
int ret = 0;
sys_clk = clk_get_parent(spear_cpufreq.clk);
if (IS_ERR(sys_clk)) {
pr_err("failed to get cpu's parent (sys) clock\n");
return PTR_ERR(sys_clk);
}
/* Set the rate of the source clock before changing the parent */
ret = clk_set_rate(sys_pclk, newfreq);
if (ret) {
pr_err("Failed to set sys clk rate to %lu\n", newfreq);
return ret;
}
ret = clk_set_parent(sys_clk, sys_pclk);
if (ret) {
pr_err("Failed to set sys clk parent\n");
return ret;
}
return 0;
}
static int spear_cpufreq_target(struct cpufreq_policy *policy,
unsigned int target_freq, unsigned int relation)
{
struct cpufreq_freqs freqs;
unsigned long newfreq;
struct clk *srcclk;
int index, ret, mult = 1;
if (cpufreq_frequency_table_target(policy, spear_cpufreq.freq_tbl,
target_freq, relation, &index))
return -EINVAL;
freqs.cpu = policy->cpu;
freqs.old = spear_cpufreq_get(0);
newfreq = spear_cpufreq.freq_tbl[index].frequency * 1000;
if (of_machine_is_compatible("st,spear1340")) {
/*
* SPEAr1340 is special in the sense that due to the possibility
* of multiple clock sources for cpu clk's parent we can have
* different clock source for different frequency of cpu clk.
* Hence we need to choose one from amongst these possible clock
* sources.
*/
srcclk = spear1340_cpu_get_possible_parent(newfreq);
if (IS_ERR(srcclk)) {
pr_err("Failed to get src clk\n");
return PTR_ERR(srcclk);
}
/* SPEAr1340: src clk is always 2 * intended cpu clk */
mult = 2;
} else {
/*
* src clock to be altered is ancestor of cpu clock. Hence we
* can directly work on cpu clk
*/
srcclk = spear_cpufreq.clk;
}
newfreq = clk_round_rate(srcclk, newfreq * mult);
if (newfreq < 0) {
pr_err("clk_round_rate failed for cpu src clock\n");
return newfreq;
}
freqs.new = newfreq / 1000;
freqs.new /= mult;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
if (mult == 2)
ret = spear1340_set_cpu_rate(srcclk, newfreq);
else
ret = clk_set_rate(spear_cpufreq.clk, newfreq);
/* Get current rate after clk_set_rate, in case of failure */
if (ret) {
pr_err("CPU Freq: cpu clk_set_rate failed: %d\n", ret);
freqs.new = clk_get_rate(spear_cpufreq.clk) / 1000;
}
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
return ret;
}
static int spear_cpufreq_init(struct cpufreq_policy *policy)
{
int ret;
ret = cpufreq_frequency_table_cpuinfo(policy, spear_cpufreq.freq_tbl);
if (ret) {
pr_err("cpufreq_frequency_table_cpuinfo() failed");
return ret;
}
cpufreq_frequency_table_get_attr(spear_cpufreq.freq_tbl, policy->cpu);
policy->cpuinfo.transition_latency = spear_cpufreq.transition_latency;
policy->cur = spear_cpufreq_get(0);
cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
cpumask_copy(policy->related_cpus, policy->cpus);
return 0;
}
static int spear_cpufreq_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_put_attr(policy->cpu);
return 0;
}
static struct freq_attr *spear_cpufreq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver spear_cpufreq_driver = {
.name = "cpufreq-spear",
.flags = CPUFREQ_STICKY,
.verify = spear_cpufreq_verify,
.target = spear_cpufreq_target,
.get = spear_cpufreq_get,
.init = spear_cpufreq_init,
.exit = spear_cpufreq_exit,
.attr = spear_cpufreq_attr,
};
static int spear_cpufreq_driver_init(void)
{
struct device_node *np;
const struct property *prop;
struct cpufreq_frequency_table *freq_tbl;
const __be32 *val;
int cnt, i, ret;
np = of_find_node_by_path("/cpus/cpu@0");
if (!np) {
pr_err("No cpu node found");
return -ENODEV;
}
if (of_property_read_u32(np, "clock-latency",
&spear_cpufreq.transition_latency))
spear_cpufreq.transition_latency = CPUFREQ_ETERNAL;
prop = of_find_property(np, "cpufreq_tbl", NULL);
if (!prop || !prop->value) {
pr_err("Invalid cpufreq_tbl");
ret = -ENODEV;
goto out_put_node;
}
cnt = prop->length / sizeof(u32);
val = prop->value;
freq_tbl = kmalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL);
if (!freq_tbl) {
ret = -ENOMEM;
goto out_put_node;
}
for (i = 0; i < cnt; i++) {
freq_tbl[i].index = i;
freq_tbl[i].frequency = be32_to_cpup(val++);
}
freq_tbl[i].index = i;
freq_tbl[i].frequency = CPUFREQ_TABLE_END;
spear_cpufreq.freq_tbl = freq_tbl;
of_node_put(np);
spear_cpufreq.clk = clk_get(NULL, "cpu_clk");
if (IS_ERR(spear_cpufreq.clk)) {
pr_err("Unable to get CPU clock\n");
ret = PTR_ERR(spear_cpufreq.clk);
goto out_put_mem;
}
ret = cpufreq_register_driver(&spear_cpufreq_driver);
if (!ret)
return 0;
pr_err("failed register driver: %d\n", ret);
clk_put(spear_cpufreq.clk);
out_put_mem:
kfree(freq_tbl);
return ret;
out_put_node:
of_node_put(np);
return ret;
}
late_initcall(spear_cpufreq_driver_init);
MODULE_AUTHOR("Deepak Sikri <deepak.sikri@st.com>");
MODULE_DESCRIPTION("SPEAr CPUFreq driver");
MODULE_LICENSE("GPL");

5
include/linux/cpufreq.h
View File

@ -11,6 +11,7 @@
#ifndef _LINUX_CPUFREQ_H
#define _LINUX_CPUFREQ_H
#include <asm/cputime.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/threads.h>
@ -22,6 +23,8 @@
#include <asm/div64.h>
#define CPUFREQ_NAME_LEN 16
/* Print length for names. Extra 1 space for accomodating '\n' in prints */
#define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
/*********************************************************************
@ -404,6 +407,4 @@ void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
unsigned int cpu);
void cpufreq_frequency_table_put_attr(unsigned int cpu);
#endif /* _LINUX_CPUFREQ_H */