net: wwan: hwsim: make wwan_hwsim_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 wwan_hwsim_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Acked-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Link: https://lore.kernel.org/r/20240302-class_cleanup-net-next-v1-4-8fa378595b93@marliere.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/wwan/wwan_hwsim.c b/drivers/net/wwan/wwan_hwsim.c
index ff3dd24..b02befd 100644 (file)
--- a/drivers/net/wwan/wwan_hwsim.c
+++ b/drivers/net/wwan/wwan_hwsim.c
@@ -25,7 +25,9 @@ static int wwan_hwsim_devsnum = 2;
 module_param_named(devices, wwan_hwsim_devsnum, int, 0444);
 MODULE_PARM_DESC(devices, "Number of simulated devices");
 
-static struct class *wwan_hwsim_class;
+static const struct class wwan_hwsim_class = {
+       .name = "wwan_hwsim",
+};
 
 static struct dentry *wwan_hwsim_debugfs_topdir;
 static struct dentry *wwan_hwsim_debugfs_devcreate;
@@ -277,7 +279,7 @@ static struct wwan_hwsim_dev *wwan_hwsim_dev_new(void)
        spin_unlock(&wwan_hwsim_devs_lock);
 
        dev->dev.release = wwan_hwsim_dev_release;
-       dev->dev.class = wwan_hwsim_class;
+       dev->dev.class = &wwan_hwsim_class;
        dev_set_name(&dev->dev, "hwsim%u", dev->id);
 
        spin_lock_init(&dev->ports_lock);
@@ -511,11 +513,9 @@ static int __init wwan_hwsim_init(void)
        if (!wwan_wq)
                return -ENOMEM;
 
-       wwan_hwsim_class = class_create("wwan_hwsim");
-       if (IS_ERR(wwan_hwsim_class)) {
-               err = PTR_ERR(wwan_hwsim_class);
+       err = class_register(&wwan_hwsim_class);
+       if (err)
                goto err_wq_destroy;
-       }
 
        wwan_hwsim_debugfs_topdir = debugfs_create_dir("wwan_hwsim", NULL);
        wwan_hwsim_debugfs_devcreate =
@@ -534,7 +534,7 @@ err_clean_devs:
        wwan_hwsim_free_devs();
        flush_workqueue(wwan_wq);       /* Wait deletion works completion */
        debugfs_remove(wwan_hwsim_debugfs_topdir);
-       class_destroy(wwan_hwsim_class);
+       class_unregister(&wwan_hwsim_class);
 err_wq_destroy:
        destroy_workqueue(wwan_wq);
 
@@ -547,7 +547,7 @@ static void __exit wwan_hwsim_exit(void)
        wwan_hwsim_free_devs();
        flush_workqueue(wwan_wq);       /* Wait deletion works completion */
        debugfs_remove(wwan_hwsim_debugfs_topdir);
-       class_destroy(wwan_hwsim_class);
+       class_unregister(&wwan_hwsim_class);
        destroy_workqueue(wwan_wq);
 }