Re: [PATCH 03/18] ACPI: platform_profile: Replace *class_dev member with class_dev

[Mario Limonciello <mario.limonciello@amd.com>]

On 1/9/2025 09:06, Kurt Borja wrote:
> Instead of holding a reference to the class device, embed it the
> platform_profile_handler. This involves manually creating and
> registering the device and replacing dev_get_drvdata() with the newly
> created to_pprof_handler() macro.
> 
> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>   drivers/acpi/platform_profile.c  | 36 +++++++++++++++++---------------
>   include/linux/platform_profile.h |  3 ++-
>   2 files changed, 21 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index 9cb82173947c..3cbde8dfed0b 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -10,6 +10,8 @@
>   #include <linux/platform_profile.h>
>   #include <linux/sysfs.h>
>   
> +#define to_pprof_handler(d)	(container_of(d, struct platform_profile_handler, class_dev))
> +
>   static DEFINE_MUTEX(profile_lock);
>   
>   static const char * const profile_names[] = {
> @@ -60,7 +62,7 @@ static int _store_class_profile(struct device *dev, void *data)
>   	int *bit = (int *)data;
>   
>   	lockdep_assert_held(&profile_lock);
> -	handler = dev_get_drvdata(dev);
> +	handler = to_pprof_handler(dev);
>   	if (!test_bit(*bit, handler->choices))
>   		return -EOPNOTSUPP;
>   
> @@ -76,11 +78,11 @@ static int _store_class_profile(struct device *dev, void *data)
>    */
>   static int _notify_class_profile(struct device *dev, void *data)
>   {
> -	struct platform_profile_handler *handler = dev_get_drvdata(dev);
> +	struct platform_profile_handler *handler = to_pprof_handler(dev);
>   
>   	lockdep_assert_held(&profile_lock);
> -	sysfs_notify(&handler->class_dev->kobj, NULL, "profile");
> -	kobject_uevent(&handler->class_dev->kobj, KOBJ_CHANGE);
> +	sysfs_notify(&handler->class_dev.kobj, NULL, "profile");
> +	kobject_uevent(&handler->class_dev.kobj, KOBJ_CHANGE);
>   
>   	return 0;
>   }
> @@ -100,7 +102,7 @@ static int get_class_profile(struct device *dev,
>   	int err;
>   
>   	lockdep_assert_held(&profile_lock);
> -	handler = dev_get_drvdata(dev);
> +	handler = to_pprof_handler(dev);
>   	err = handler->ops->profile_get(handler, &val);
>   	if (err) {
>   		pr_err("Failed to get profile for handler %s\n", handler->name);
> @@ -124,7 +126,7 @@ static int get_class_profile(struct device *dev,
>    */
>   static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
>   {
> -	struct platform_profile_handler *handler = dev_get_drvdata(dev);
> +	struct platform_profile_handler *handler = to_pprof_handler(dev);
>   
>   	return sysfs_emit(buf, "%s\n", handler->name);
>   }
> @@ -142,7 +144,7 @@ static ssize_t choices_show(struct device *dev,
>   			    struct device_attribute *attr,
>   			    char *buf)
>   {
> -	struct platform_profile_handler *handler = dev_get_drvdata(dev);
> +	struct platform_profile_handler *handler = to_pprof_handler(dev);
>   
>   	return _commmon_choices_show(handler->choices, buf);
>   }
> @@ -229,7 +231,7 @@ static int _aggregate_choices(struct device *dev, void *data)
>   	unsigned long *aggregate = data;
>   
>   	lockdep_assert_held(&profile_lock);
> -	handler = dev_get_drvdata(dev);
> +	handler = to_pprof_handler(dev);
>   	if (test_bit(PLATFORM_PROFILE_LAST, aggregate))
>   		bitmap_copy(aggregate, handler->choices, PLATFORM_PROFILE_LAST);
>   	else
> @@ -410,7 +412,7 @@ static const struct attribute_group platform_profile_group = {
>   void platform_profile_notify(struct platform_profile_handler *pprof)
>   {
>   	scoped_cond_guard(mutex_intr, return, &profile_lock) {
> -		_notify_class_profile(pprof->class_dev, NULL);
> +		_notify_class_profile(&pprof->class_dev, NULL);
>   	}
>   	sysfs_notify(acpi_kobj, NULL, "platform_profile");
>   }
> @@ -485,13 +487,13 @@ int platform_profile_register(struct platform_profile_handler *pprof)
>   	pprof->minor = ida_alloc(&platform_profile_ida, GFP_KERNEL);
>   	if (pprof->minor < 0)
>   		return pprof->minor;
> -	pprof->class_dev = device_create(&platform_profile_class, pprof->dev,
> -					 MKDEV(0, 0), pprof, "platform-profile-%d",
> -					 pprof->minor);
> -	if (IS_ERR(pprof->class_dev)) {
> -		err = PTR_ERR(pprof->class_dev);
> +
> +	pprof->class_dev.class = &platform_profile_class;
> +	pprof->class_dev.parent = pprof->dev;
> +	dev_set_name(&pprof->class_dev, "platform-profile-%d", pprof->minor);
> +	err = device_register(&pprof->class_dev);
> +	if (err)
>   		goto cleanup_ida;
> -	}
>   
>   	sysfs_notify(acpi_kobj, NULL, "platform_profile");
>   
> @@ -502,7 +504,7 @@ int platform_profile_register(struct platform_profile_handler *pprof)
>   	return 0;
>   
>   cleanup_cur:
> -	device_unregister(pprof->class_dev);
> +	device_unregister(&pprof->class_dev);
>   
>   cleanup_ida:
>   	ida_free(&platform_profile_ida, pprof->minor);
> @@ -517,7 +519,7 @@ int platform_profile_remove(struct platform_profile_handler *pprof)
>   	guard(mutex)(&profile_lock);
>   
>   	id = pprof->minor;
> -	device_unregister(pprof->class_dev);
> +	device_unregister(&pprof->class_dev);
>   	ida_free(&platform_profile_ida, id);
>   
>   	sysfs_notify(acpi_kobj, NULL, "platform_profile");
> diff --git a/include/linux/platform_profile.h b/include/linux/platform_profile.h
> index 972a62be60b2..f549067539af 100644
> --- a/include/linux/platform_profile.h
> +++ b/include/linux/platform_profile.h
> @@ -9,6 +9,7 @@
>   #ifndef _PLATFORM_PROFILE_H_
>   #define _PLATFORM_PROFILE_H_
>   
> +#include <linux/device.h>
>   #include <linux/bitops.h>
>   
>   /*
> @@ -40,7 +41,7 @@ struct platform_profile_ops {
>   struct platform_profile_handler {
>   	const char *name;
>   	struct device *dev;
> -	struct device *class_dev;
> +	struct device class_dev;
>   	int minor;
>   	unsigned long choices[BITS_TO_LONGS(PLATFORM_PROFILE_LAST)];
>   	const struct platform_profile_ops *ops;