Unverified Commit d03cfde5 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Ilpo Järvinen
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platform/x86: firmware_attributes_class: Simplify API 



The module core already guarantees that a module can only be unloaded
after all other modules using its symbols have been unloaded.
As it's already the responsibility of the drivers using
firmware_attributes_class to clean up their devices before unloading,
the lifetime of the firmware_attributes_class can be bound to the
lifetime of the module.
This enables the direct usage of firmware_attributes_class from the
drivers, without having to go through the lifecycle functions,
leading to simplifications for both the subsystem and its users.

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Reviewed-by: default avatarArmin Wolf <W_Armin@gmx.de>
Reviewed-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Reviewed-by: default avatarMark Pearson <mpearson-lenovo@squebb.ca>
Tested-by: default avatarMark Pearson <mpearson-lenovo@squebb.ca>
Link: https://lore.kernel.org/r/20250104-firmware-attributes-simplify-v1-2-949f9709e405@weissschuh.net


Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
parent d0eee1be

drivers/platform/x86/firmware_attributes_class.c

+14 −26
Original line number Diff line number Diff line
@@ -2,47 +2,35 @@ 


/* Firmware attributes class helper module */



#include <linux/mutex.h>

#include <linux/module.h>

#include "firmware_attributes_class.h"



static DEFINE_MUTEX(fw_attr_lock);

static int fw_attr_inuse;



static const struct class firmware_attributes_class = {

const struct class firmware_attributes_class = {

	.name = "firmware-attributes",

};

EXPORT_SYMBOL_GPL(firmware_attributes_class);



int fw_attributes_class_get(const struct class **fw_attr_class)

static __init int fw_attributes_class_init(void)

{

	int err;



	mutex_lock(&fw_attr_lock);

	if (!fw_attr_inuse) { /*first time class is being used*/

		err = class_register(&firmware_attributes_class);

		if (err) {

			mutex_unlock(&fw_attr_lock);

			return err;

	return class_register(&firmware_attributes_class);

}

module_init(fw_attributes_class_init);



static __exit void fw_attributes_class_exit(void)

{

	class_unregister(&firmware_attributes_class);

}

	fw_attr_inuse++;

module_exit(fw_attributes_class_exit);



int fw_attributes_class_get(const struct class **fw_attr_class)

{

	*fw_attr_class = &firmware_attributes_class;

	mutex_unlock(&fw_attr_lock);

	return 0;

}

EXPORT_SYMBOL_GPL(fw_attributes_class_get);



int fw_attributes_class_put(void)

{

	mutex_lock(&fw_attr_lock);

	if (!fw_attr_inuse) {

		mutex_unlock(&fw_attr_lock);

		return -EINVAL;

	}

	fw_attr_inuse--;

	if (!fw_attr_inuse) /* No more consumers */

		class_unregister(&firmware_attributes_class);

	mutex_unlock(&fw_attr_lock);

	return 0;

}

EXPORT_SYMBOL_GPL(fw_attributes_class_put);

drivers/platform/x86/firmware_attributes_class.h

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 


#include <linux/device/class.h>



extern const struct class firmware_attributes_class;

int fw_attributes_class_get(const struct class **fw_attr_class);

int fw_attributes_class_put(void);