s390/tape: make tape_class constant

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the tape_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240305-class_cleanup-s390-v1-4-c4ff1ec49ffd@marliere.net
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/drivers/s390/char/tape_class.c b/drivers/s390/char/tape_class.c
index 277a0f903d11bfdb50e2c545286358dac3c8a86a..eae362bbfbb55dab640e28869188e1960befe4af 100644 (file)
--- a/drivers/s390/char/tape_class.c
+++ b/drivers/s390/char/tape_class.c
@@ -22,7 +22,9 @@ MODULE_DESCRIPTION(
 );
 MODULE_LICENSE("GPL");
 
-static struct class *tape_class;
+static const struct class tape_class = {
+       .name = "tape390",
+};
 
 /*
  * Register a tape device and return a pointer to the cdev structure.
@@ -74,7 +76,7 @@ struct tape_class_device *register_tape_dev(
        if (rc)
                goto fail_with_cdev;
 
-       tcd->class_device = device_create(tape_class, device,
+       tcd->class_device = device_create(&tape_class, device,
                                          tcd->char_device->dev, NULL,
                                          "%s", tcd->device_name);
        rc = PTR_ERR_OR_ZERO(tcd->class_device);
@@ -91,7 +93,7 @@ struct tape_class_device *register_tape_dev(
        return tcd;
 
 fail_with_class_device:
-       device_destroy(tape_class, tcd->char_device->dev);
+       device_destroy(&tape_class, tcd->char_device->dev);
 
 fail_with_cdev:
        cdev_del(tcd->char_device);
@@ -107,7 +109,7 @@ void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)
 {
        if (tcd != NULL && !IS_ERR(tcd)) {
                sysfs_remove_link(&device->kobj, tcd->mode_name);
-               device_destroy(tape_class, tcd->char_device->dev);
+               device_destroy(&tape_class, tcd->char_device->dev);
                cdev_del(tcd->char_device);
                kfree(tcd);
        }
@@ -117,15 +119,12 @@ EXPORT_SYMBOL(unregister_tape_dev);
 
 static int __init tape_init(void)
 {
-       tape_class = class_create("tape390");
-
-       return 0;
+       return class_register(&tape_class);
 }
 
 static void __exit tape_exit(void)
 {
-       class_destroy(tape_class);
-       tape_class = NULL;
+       class_unregister(&tape_class);
 }
 
 postcore_initcall(tape_init);