From 2361be23666232dbb4851a527f466c4cbf5340fc Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Fri, 17 May 2013 16:09:09 +0530 Subject: [PATCH] cpufreq: Don't create empty /sys/devices/system/cpu/cpufreq directory When we don't have any file in cpu/cpufreq directory we shouldn't create it. Specially with the introduction of per-policy governor instance patchset, even governors are moved to cpu/cpu*/cpufreq/governor-name directory and so this directory is just not required. Lets have it only when required. Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/acpi-cpufreq.c | 4 +-- drivers/cpufreq/cpufreq.c | 48 +++++++++++++++++++++++++++--- drivers/cpufreq/cpufreq_governor.c | 6 ++++ include/linux/cpufreq.h | 4 +++ 4 files changed, 56 insertions(+), 6 deletions(-) diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index 11b8b4b54ceb..8c02622b35a4 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -947,7 +947,7 @@ static void __init acpi_cpufreq_boost_init(void) /* We create the boost file in any case, though for systems without * hardware support it will be read-only and hardwired to return 0. */ - if (sysfs_create_file(cpufreq_global_kobject, &(global_boost.attr))) + if (cpufreq_sysfs_create_file(&(global_boost.attr))) pr_warn(PFX "could not register global boost sysfs file\n"); else pr_debug("registered global boost sysfs file\n"); @@ -955,7 +955,7 @@ static void __init acpi_cpufreq_boost_init(void) static void __exit acpi_cpufreq_boost_exit(void) { - sysfs_remove_file(cpufreq_global_kobject, &(global_boost.attr)); + cpufreq_sysfs_remove_file(&(global_boost.attr)); if (msrs) { unregister_cpu_notifier(&boost_nb); diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index c6ab21880c07..ce9273a7b4e3 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -678,9 +678,6 @@ static struct attribute *default_attrs[] = { NULL }; -struct kobject *cpufreq_global_kobject; -EXPORT_SYMBOL(cpufreq_global_kobject); - #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) #define to_attr(a) container_of(a, struct freq_attr, attr) @@ -751,6 +748,49 @@ static struct kobj_type ktype_cpufreq = { .release = cpufreq_sysfs_release, }; +struct kobject *cpufreq_global_kobject; +EXPORT_SYMBOL(cpufreq_global_kobject); + +static int cpufreq_global_kobject_usage; + +int cpufreq_get_global_kobject(void) +{ + if (!cpufreq_global_kobject_usage++) + return kobject_add(cpufreq_global_kobject, + &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); + + return 0; +} +EXPORT_SYMBOL(cpufreq_get_global_kobject); + +void cpufreq_put_global_kobject(void) +{ + if (!--cpufreq_global_kobject_usage) + kobject_del(cpufreq_global_kobject); +} +EXPORT_SYMBOL(cpufreq_put_global_kobject); + +int cpufreq_sysfs_create_file(const struct attribute *attr) +{ + int ret = cpufreq_get_global_kobject(); + + if (!ret) { + ret = sysfs_create_file(cpufreq_global_kobject, attr); + if (ret) + cpufreq_put_global_kobject(); + } + + return ret; +} +EXPORT_SYMBOL(cpufreq_sysfs_create_file); + +void cpufreq_sysfs_remove_file(const struct attribute *attr) +{ + sysfs_remove_file(cpufreq_global_kobject, attr); + cpufreq_put_global_kobject(); +} +EXPORT_SYMBOL(cpufreq_sysfs_remove_file); + /* symlink affected CPUs */ static int cpufreq_add_dev_symlink(unsigned int cpu, struct cpufreq_policy *policy) @@ -2020,7 +2060,7 @@ static int __init cpufreq_core_init(void) init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); } - cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); + cpufreq_global_kobject = kobject_create(); BUG_ON(!cpufreq_global_kobject); register_syscore_ops(&cpufreq_syscore_ops); diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c index b6cfd55d8266..7532570c42b4 100644 --- a/drivers/cpufreq/cpufreq_governor.c +++ b/drivers/cpufreq/cpufreq_governor.c @@ -231,6 +231,9 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy, return rc; } + if (!have_governor_per_policy()) + WARN_ON(cpufreq_get_global_kobject()); + rc = sysfs_create_group(get_governor_parent_kobj(policy), get_sysfs_attr(dbs_data)); if (rc) { @@ -269,6 +272,9 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy, sysfs_remove_group(get_governor_parent_kobj(policy), get_sysfs_attr(dbs_data)); + if (!have_governor_per_policy()) + cpufreq_put_global_kobject(); + if ((dbs_data->cdata->governor == GOV_CONSERVATIVE) && (policy->governor->initialized == 1)) { struct cs_ops *cs_ops = dbs_data->cdata->gov_ops; diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index fbf392aaa02e..1b5b5efa3e3a 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -71,6 +71,10 @@ struct cpufreq_governor; /* /sys/devices/system/cpu/cpufreq: entry point for global variables */ extern struct kobject *cpufreq_global_kobject; +int cpufreq_get_global_kobject(void); +void cpufreq_put_global_kobject(void); +int cpufreq_sysfs_create_file(const struct attribute *attr); +void cpufreq_sysfs_remove_file(const struct attribute *attr); #define CPUFREQ_ETERNAL (-1) struct cpufreq_cpuinfo { -- 2.20.1