USB: gadget: f_hid: make hidg_class a static const structure

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

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230620094412.508580-11-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 9f6b101..ea85e2c 100644 (file)
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -23,7 +23,11 @@
 #define HIDG_MINORS    4
 
 static int major, minors;
-static struct class *hidg_class;
+
+static const struct class hidg_class = {
+       .name = "hidg",
+};
+
 static DEFINE_IDA(hidg_ida);
 static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
 
@@ -1272,7 +1276,7 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 
        device_initialize(&hidg->dev);
        hidg->dev.release = hidg_release;
-       hidg->dev.class = hidg_class;
+       hidg->dev.class = &hidg_class;
        hidg->dev.devt = MKDEV(major, opts->minor);
        ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
        if (ret)
@@ -1325,17 +1329,13 @@ int ghid_setup(struct usb_gadget *g, int count)
        int status;
        dev_t dev;
 
-       hidg_class = class_create("hidg");
-       if (IS_ERR(hidg_class)) {
-               status = PTR_ERR(hidg_class);
-               hidg_class = NULL;
+       status = class_register(&hidg_class);
+       if (status)
                return status;
-       }
 
        status = alloc_chrdev_region(&dev, 0, count, "hidg");
        if (status) {
-               class_destroy(hidg_class);
-               hidg_class = NULL;
+               class_unregister(&hidg_class);
                return status;
        }
 
@@ -1352,6 +1352,5 @@ void ghid_cleanup(void)
                major = minors = 0;
        }
 
-       class_destroy(hidg_class);
-       hidg_class = NULL;
+       class_unregister(&hidg_class);
 }