virtio_console: make port class a static const structure

Now that the driver core allows for struct class to be in read-only
memory, remove the class field of the ports_driver_data structure and
create the port_class static class structure declared at build time
which places it into read-only memory, instead of having it to be
dynamically allocated at load time.

Cc: Amit Shah <amit@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: virtualization@lists.linux-foundation.org
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230620143751.578239-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index b65c809a4e978d41ba80bfab5b6fab1c5f9a2b7b..1f8da0a71ce93f33f5fadf3fd3d1a61b347be45e 100644 (file)
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -40,9 +40,6 @@
  * across multiple devices and multiple ports per device.
  */
 struct ports_driver_data {
-       /* Used for registering chardevs */
-       struct class *class;
-
        /* Used for exporting per-port information to debugfs */
        struct dentry *debugfs_dir;
 
@@ -55,6 +52,10 @@ struct ports_driver_data {
 
 static struct ports_driver_data pdrvdata;
 
+static const struct class port_class = {
+       .name = "virtio-ports",
+};
+
 static DEFINE_SPINLOCK(pdrvdata_lock);
 static DECLARE_COMPLETION(early_console_added);
 
@@ -1399,7 +1400,7 @@ static int add_port(struct ports_device *portdev, u32 id)
                        "Error %d adding cdev for port %u\n", err, id);
                goto free_cdev;
        }
-       port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
+       port->dev = device_create(&port_class, &port->portdev->vdev->dev,
                                  devt, port, "vport%up%u",
                                  port->portdev->vdev->index, id);
        if (IS_ERR(port->dev)) {
@@ -1465,7 +1466,7 @@ static int add_port(struct ports_device *portdev, u32 id)
 
 free_inbufs:
 free_device:
-       device_destroy(pdrvdata.class, port->dev->devt);
+       device_destroy(&port_class, port->dev->devt);
 free_cdev:
        cdev_del(port->cdev);
 free_port:
@@ -1540,7 +1541,7 @@ static void unplug_port(struct port *port)
        port->portdev = NULL;
 
        sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
-       device_destroy(pdrvdata.class, port->dev->devt);
+       device_destroy(&port_class, port->dev->devt);
        cdev_del(port->cdev);
 
        debugfs_remove(port->debugfs_file);
@@ -2244,12 +2245,9 @@ static int __init virtio_console_init(void)
 {
        int err;
 
-       pdrvdata.class = class_create("virtio-ports");
-       if (IS_ERR(pdrvdata.class)) {
-               err = PTR_ERR(pdrvdata.class);
-               pr_err("Error %d creating virtio-ports class\n", err);
+       err = class_register(&port_class);
+       if (err)
                return err;
-       }
 
        pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
        INIT_LIST_HEAD(&pdrvdata.consoles);
@@ -2271,7 +2269,7 @@ unregister:
        unregister_virtio_driver(&virtio_console);
 free:
        debugfs_remove_recursive(pdrvdata.debugfs_dir);
-       class_destroy(pdrvdata.class);
+       class_unregister(&port_class);
        return err;
 }
 
@@ -2282,7 +2280,7 @@ static void __exit virtio_console_fini(void)
        unregister_virtio_driver(&virtio_console);
        unregister_virtio_driver(&virtio_rproc_serial);
 
-       class_destroy(pdrvdata.class);
+       class_unregister(&port_class);
        debugfs_remove_recursive(pdrvdata.debugfs_dir);
 }
 module_init(virtio_console_init);