[PATCH 2/2] platform/x86/intel-uncore-freq: Add release callback

From: Srinivas Pandruvada
Date: Sat Feb 08 2020 - 12:01:24 EST


On module unload wait for relese callback for each packag_die entry
and then free the memory. This is done by waiting on a completion
object, till release() callback.

While here, also change to kobject_init_and_add() to
kobject_create_and_add() to simplify.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
drivers/platform/x86/intel-uncore-frequency.c | 36 ++++++++++++-------
1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/drivers/platform/x86/intel-uncore-frequency.c b/drivers/platform/x86/intel-uncore-frequency.c
index c83ec95e8f3e..82f2de7c4112 100644
--- a/drivers/platform/x86/intel-uncore-frequency.c
+++ b/drivers/platform/x86/intel-uncore-frequency.c
@@ -38,6 +38,7 @@
*/
struct uncore_data {
struct kobject kobj;
+ struct completion kobj_unregister;
u64 stored_uncore_data;
u32 initial_min_freq_khz;
u32 initial_max_freq_khz;
@@ -52,7 +53,7 @@ static int uncore_max_entries __read_mostly;
/* Storage for uncore data for all instances */
static struct uncore_data *uncore_instances;
/* Root of the all uncore sysfs kobjs */
-struct kobject uncore_root_kobj;
+struct kobject *uncore_root_kobj;
/* Stores the CPU mask of the target CPUs to use during uncore read/write */
static cpumask_t uncore_cpu_mask;
/* CPU online callback register instance */
@@ -225,15 +226,19 @@ static struct attribute *uncore_attrs[] = {
NULL
};

+static void uncore_sysfs_entry_release(struct kobject *kobj)
+{
+ struct uncore_data *data = to_uncore_data(kobj);
+
+ complete(&data->kobj_unregister);
+}
+
static struct kobj_type uncore_ktype = {
+ .release = uncore_sysfs_entry_release,
.sysfs_ops = &kobj_sysfs_ops,
.default_attrs = uncore_attrs,
};

-static struct kobj_type uncore_root_ktype = {
- .sysfs_ops = &kobj_sysfs_ops,
-};
-
/* Caller provides protection */
static struct uncore_data *uncore_get_instance(unsigned int cpu)
{
@@ -271,8 +276,10 @@ static void uncore_add_die_entry(int cpu)
uncore_read_ratio(data, &data->initial_min_freq_khz,
&data->initial_max_freq_khz);

+ init_completion(&data->kobj_unregister);
+
ret = kobject_init_and_add(&data->kobj, &uncore_ktype,
- &uncore_root_kobj, str);
+ uncore_root_kobj, str);
if (!ret) {
data->control_cpu = cpu;
data->valid = true;
@@ -391,11 +398,12 @@ static int __init intel_uncore_init(void)
if (!uncore_instances)
return -ENOMEM;

- ret = kobject_init_and_add(&uncore_root_kobj, &uncore_root_ktype,
- &cpu_subsys.dev_root->kobj,
- "intel_uncore_frequency");
- if (ret)
+ uncore_root_kobj = kobject_create_and_add("intel_uncore_frequency",
+ &cpu_subsys.dev_root->kobj);
+ if (!uncore_root_kobj) {
+ ret = -ENOMEM;
goto err_free;
+ }

ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
"platform/x86/uncore-freq:online",
@@ -415,7 +423,7 @@ static int __init intel_uncore_init(void)
err_rem_state:
cpuhp_remove_state(uncore_hp_state);
err_rem_kobj:
- kobject_put(&uncore_root_kobj);
+ kobject_put(uncore_root_kobj);
err_free:
kfree(uncore_instances);

@@ -430,10 +438,12 @@ static void __exit intel_uncore_exit(void)
unregister_pm_notifier(&uncore_pm_nb);
cpuhp_remove_state(uncore_hp_state);
for (i = 0; i < uncore_max_entries; ++i) {
- if (uncore_instances[i].valid)
+ if (uncore_instances[i].valid) {
kobject_put(&uncore_instances[i].kobj);
+ wait_for_completion(&uncore_instances[i].kobj_unregister);
+ }
}
- kobject_put(&uncore_root_kobj);
+ kobject_put(uncore_root_kobj);
kfree(uncore_instances);
}
module_exit(intel_uncore_exit)
--
2.20.1