char: lp: make lp_class a static const structure

Now that the driver core allows for struct class to be in read-only
memory, move the lp_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at load time.

Cc: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230620143751.578239-12-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index 70cfc5140c2cb8470e76d9e6356912920bfca5b9..2f171d14b9b50708ab342b074e009b4ded819f83 100644 (file)
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -145,7 +145,9 @@ static struct lp_struct lp_table[LP_NO];
 static int port_num[LP_NO];
 
 static unsigned int lp_count = 0;
-static struct class *lp_class;
+static const struct class lp_class = {
+       .name = "printer",
+};
 
 #ifdef CONFIG_LP_CONSOLE
 static struct parport *console_registered;
@@ -932,7 +934,7 @@ static int lp_register(int nr, struct parport *port)
        if (reset)
                lp_reset(nr);
 
-       device_create(lp_class, port->dev, MKDEV(LP_MAJOR, nr), NULL,
+       device_create(&lp_class, port->dev, MKDEV(LP_MAJOR, nr), NULL,
                      "lp%d", nr);
 
        printk(KERN_INFO "lp%d: using %s (%s).\n", nr, port->name,
@@ -1004,7 +1006,7 @@ static void lp_detach(struct parport *port)
                if (port_num[n] == port->number) {
                        port_num[n] = -1;
                        lp_count--;
-                       device_destroy(lp_class, MKDEV(LP_MAJOR, n));
+                       device_destroy(&lp_class, MKDEV(LP_MAJOR, n));
                        parport_unregister_device(lp_table[n].dev);
                }
        }
@@ -1049,11 +1051,9 @@ static int __init lp_init(void)
                return -EIO;
        }
 
-       lp_class = class_create("printer");
-       if (IS_ERR(lp_class)) {
-               err = PTR_ERR(lp_class);
+       err = class_register(&lp_class);
+       if (err)
                goto out_reg;
-       }
 
        if (parport_register_driver(&lp_driver)) {
                printk(KERN_ERR "lp: unable to register with parport\n");
@@ -1072,7 +1072,7 @@ static int __init lp_init(void)
        return 0;
 
 out_class:
-       class_destroy(lp_class);
+       class_unregister(&lp_class);
 out_reg:
        unregister_chrdev(LP_MAJOR, "lp");
        return err;
@@ -1115,7 +1115,7 @@ static void lp_cleanup_module(void)
 #endif
 
        unregister_chrdev(LP_MAJOR, "lp");
-       class_destroy(lp_class);
+       class_unregister(&lp_class);
 }
 
 __setup("lp=", lp_setup);