Re: [PATCH 1/11] cpufreq: Clean up default and fallback governor setup

From: Saravana Kannan
Date: Wed Feb 03 2016 - 19:55:42 EST


On 02/03/2016 03:14 PM, Rafael J. Wysocki wrote:
From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

The preprocessor magic used for setting the default cpufreq governor
(and for using the performance governor as a fallback one for that
matter) is really nasty, so replace it with __weak functions and
overrides.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 37 ++++++++++++++++++---------------
drivers/cpufreq/cpufreq_conservative.c | 10 +++++---
drivers/cpufreq/cpufreq_ondemand.c | 34 ++++++++++++++++--------------
drivers/cpufreq/cpufreq_performance.c | 18 ++++++++++++----
drivers/cpufreq/cpufreq_powersave.c | 10 +++++---
drivers/cpufreq/cpufreq_userspace.c | 10 +++++---
include/linux/cpufreq.h | 25 +---------------------
7 files changed, 73 insertions(+), 71 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq.c
+++ linux-pm/drivers/cpufreq/cpufreq.c
@@ -1003,6 +1003,11 @@ static int cpufreq_add_dev_interface(str
return cpufreq_add_dev_symlink(policy);
}

+__weak struct cpufreq_governor *cpufreq_default_governor(void)
+{
+ return NULL;
+}
+
static int cpufreq_init_policy(struct cpufreq_policy *policy)
{
struct cpufreq_governor *gov = NULL;
@@ -1012,11 +1017,14 @@ static int cpufreq_init_policy(struct cp

/* Update governor of new_policy to the governor used before hotplug */
gov = find_governor(policy->last_governor);
- if (gov)
+ if (gov) {
pr_debug("Restoring governor %s for cpu %d\n",
policy->governor->name, policy->cpu);
- else
- gov = CPUFREQ_DEFAULT_GOVERNOR;
+ } else {
+ gov = cpufreq_default_governor();
+ if (!gov)
+ return -ENODATA;
+ }

new_policy.governor = gov;

@@ -1964,21 +1972,16 @@ int cpufreq_driver_target(struct cpufreq
}
EXPORT_SYMBOL_GPL(cpufreq_driver_target);

+__weak struct cpufreq_governor *cpufreq_fallback_governor(void)
+{
+ return NULL;
+}
+
static int __cpufreq_governor(struct cpufreq_policy *policy,
unsigned int event)
{
int ret;

- /* Only must be defined when default governor is known to have latency
- restrictions, like e.g. conservative or ondemand.
- That this is the case is already ensured in Kconfig
- */
-#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
- struct cpufreq_governor *gov = &cpufreq_gov_performance;
-#else
- struct cpufreq_governor *gov = NULL;
-#endif
-
/* Don't start any governor operations if we are entering suspend */
if (cpufreq_suspended)
return 0;
@@ -1992,12 +1995,14 @@ static int __cpufreq_governor(struct cpu
if (policy->governor->max_transition_latency &&
policy->cpuinfo.transition_latency >
policy->governor->max_transition_latency) {
- if (!gov)
- return -EINVAL;
- else {
+ struct cpufreq_governor *gov = cpufreq_fallback_governor();
+
+ if (gov) {
pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
policy->governor->name, gov->name);
policy->governor = gov;
+ } else {
+ return -EINVAL;
}
}

Index: linux-pm/drivers/cpufreq/cpufreq_conservative.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_conservative.c
+++ linux-pm/drivers/cpufreq/cpufreq_conservative.c
@@ -26,10 +26,7 @@ static DEFINE_PER_CPU(struct cs_cpu_dbs_
static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
unsigned int event);

-#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
-static
-#endif
-struct cpufreq_governor cpufreq_gov_conservative = {
+static struct cpufreq_governor cpufreq_gov_conservative = {
.name = "conservative",
.governor = cs_cpufreq_governor_dbs,
.max_transition_latency = TRANSITION_LATENCY_LIMIT,
@@ -397,6 +394,11 @@ MODULE_DESCRIPTION("'cpufreq_conservativ
MODULE_LICENSE("GPL");

#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
+struct cpufreq_governor *cpufreq_default_governor(void)
+{
+ return &cpufreq_gov_conservative;
+}
+
fs_initcall(cpufreq_gov_dbs_init);
#else
module_init(cpufreq_gov_dbs_init);
Index: linux-pm/include/linux/cpufreq.h
===================================================================
--- linux-pm.orig/include/linux/cpufreq.h
+++ linux-pm/include/linux/cpufreq.h
@@ -471,29 +471,8 @@ int __cpufreq_driver_target(struct cpufr
int cpufreq_register_governor(struct cpufreq_governor *governor);
void cpufreq_unregister_governor(struct cpufreq_governor *governor);

-/* CPUFREQ DEFAULT GOVERNOR */
-/*
- * Performance governor is fallback governor if any other gov failed to auto
- * load due latency restrictions
- */
-#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
-extern struct cpufreq_governor cpufreq_gov_performance;
-#endif
-#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
-#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
-#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
-extern struct cpufreq_governor cpufreq_gov_powersave;
-#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
-#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
-extern struct cpufreq_governor cpufreq_gov_userspace;
-#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
-#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
-extern struct cpufreq_governor cpufreq_gov_ondemand;
-#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
-#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
-extern struct cpufreq_governor cpufreq_gov_conservative;
-#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
-#endif
+struct cpufreq_governor *cpufreq_default_governor(void);
+struct cpufreq_governor *cpufreq_fallback_governor(void);

/*********************************************************************
* FREQUENCY TABLE HELPERS *
Index: linux-pm/drivers/cpufreq/cpufreq_ondemand.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_ondemand.c
+++ linux-pm/drivers/cpufreq/cpufreq_ondemand.c
@@ -553,6 +553,19 @@ static struct common_dbs_data od_dbs_cda
.mutex = __MUTEX_INITIALIZER(od_dbs_cdata.mutex),
};

+static int od_cpufreq_governor_dbs(struct cpufreq_policy *policy,
+ unsigned int event)
+{
+ return cpufreq_governor_dbs(policy, &od_dbs_cdata, event);
+}
+
+static struct cpufreq_governor cpufreq_gov_ondemand = {
+ .name = "ondemand",
+ .governor = od_cpufreq_governor_dbs,
+ .max_transition_latency = TRANSITION_LATENCY_LIMIT,
+ .owner = THIS_MODULE,
+};
+
static void od_set_powersave_bias(unsigned int powersave_bias)
{
struct cpufreq_policy *policy;
@@ -604,22 +617,6 @@ void od_unregister_powersave_bias_handle
}
EXPORT_SYMBOL_GPL(od_unregister_powersave_bias_handler);

-static int od_cpufreq_governor_dbs(struct cpufreq_policy *policy,
- unsigned int event)
-{
- return cpufreq_governor_dbs(policy, &od_dbs_cdata, event);
-}
-
-#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
-static
-#endif
-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)
{
return cpufreq_register_governor(&cpufreq_gov_ondemand);
@@ -637,6 +634,11 @@ MODULE_DESCRIPTION("'cpufreq_ondemand' -
MODULE_LICENSE("GPL");

#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
+struct cpufreq_governor *cpufreq_default_governor(void)
+{
+ return &cpufreq_gov_ondemand;
+}
+
fs_initcall(cpufreq_gov_dbs_init);
#else
module_init(cpufreq_gov_dbs_init);
Index: linux-pm/drivers/cpufreq/cpufreq_performance.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_performance.c
+++ linux-pm/drivers/cpufreq/cpufreq_performance.c
@@ -33,10 +33,7 @@ static int cpufreq_governor_performance(
return 0;
}

-#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE_MODULE
-static
-#endif
-struct cpufreq_governor cpufreq_gov_performance = {
+static struct cpufreq_governor cpufreq_gov_performance = {
.name = "performance",
.governor = cpufreq_governor_performance,
.owner = THIS_MODULE,
@@ -52,6 +49,19 @@ static void __exit cpufreq_gov_performan
cpufreq_unregister_governor(&cpufreq_gov_performance);
}

+#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
+struct cpufreq_governor *cpufreq_default_governor(void)
+{
+ return &cpufreq_gov_performance;
+}
+#endif
+#ifndef CONFIG_CPU_FREQ_GOV_PERFORMANCE_MODULE
+struct cpufreq_governor *cpufreq_fallback_governor(void)
+{
+ return &cpufreq_gov_performance;
+}
+#endif
+
MODULE_AUTHOR("Dominik Brodowski <linux@xxxxxxxx>");
MODULE_DESCRIPTION("CPUfreq policy governor 'performance'");
MODULE_LICENSE("GPL");
Index: linux-pm/drivers/cpufreq/cpufreq_powersave.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_powersave.c
+++ linux-pm/drivers/cpufreq/cpufreq_powersave.c
@@ -33,10 +33,7 @@ static int cpufreq_governor_powersave(st
return 0;
}

-#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE
-static
-#endif
-struct cpufreq_governor cpufreq_gov_powersave = {
+static struct cpufreq_governor cpufreq_gov_powersave = {
.name = "powersave",
.governor = cpufreq_governor_powersave,
.owner = THIS_MODULE,
@@ -57,6 +54,11 @@ MODULE_DESCRIPTION("CPUfreq policy gover
MODULE_LICENSE("GPL");

#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE
+struct cpufreq_governor *cpufreq_default_governor(void)
+{
+ return &cpufreq_gov_powersave;
+}
+
fs_initcall(cpufreq_gov_powersave_init);
#else
module_init(cpufreq_gov_powersave_init);
Index: linux-pm/drivers/cpufreq/cpufreq_userspace.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_userspace.c
+++ linux-pm/drivers/cpufreq/cpufreq_userspace.c
@@ -89,10 +89,7 @@ static int cpufreq_governor_userspace(st
return rc;
}

-#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
-static
-#endif
-struct cpufreq_governor cpufreq_gov_userspace = {
+static struct cpufreq_governor cpufreq_gov_userspace = {
.name = "userspace",
.governor = cpufreq_governor_userspace,
.store_setspeed = cpufreq_set,
@@ -116,6 +113,11 @@ MODULE_DESCRIPTION("CPUfreq policy gover
MODULE_LICENSE("GPL");

#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE
+struct cpufreq_governor *cpufreq_default_governor(void)
+{
+ return &cpufreq_gov_userspace;
+}
+
fs_initcall(cpufreq_gov_userspace_init);
#else
module_init(cpufreq_gov_userspace_init);

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Ah, that's so much more cleaner!

Acked-by: Saravana Kannan <skannan@xxxxxxxxxxxxxx>


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