mips: sibyte: make tb_class constant

Since commit 43a7206b ("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 tb_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>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/sibyte/common/sb_tbprof.c

@@ -535,13 +535,14 @@ static const struct file_operations sbprof_tb_fops = {
 	.llseek		= default_llseek,
 };
 
-static struct class *tb_class;
+static const struct class tb_class = {
+	.name = "sb_tracebuffer",
+};
 static struct device *tb_dev;
 
 static int __init sbprof_tb_init(void)
 {
 	struct device *dev;
-	struct class *tbc;
 	int err;
 
 	if (register_chrdev(SBPROF_TB_MAJOR, DEVNAME, &sbprof_tb_fops)) {
@@ -550,15 +551,11 @@ static int __init sbprof_tb_init(void)
 		return -EIO;
 	}
 
-	tbc = class_create("sb_tracebuffer");
-	if (IS_ERR(tbc)) {
-		err = PTR_ERR(tbc);
+	err = class_register(&tb_class);
+	if (err)
 		goto out_chrdev;
-	}
-
-	tb_class = tbc;
 
-	dev = device_create(tbc, NULL, MKDEV(SBPROF_TB_MAJOR, 0), NULL, "tb");
+	dev = device_create(&tb_class, NULL, MKDEV(SBPROF_TB_MAJOR, 0), NULL, "tb");
 	if (IS_ERR(dev)) {
 		err = PTR_ERR(dev);
 		goto out_class;
@@ -573,7 +570,7 @@ static int __init sbprof_tb_init(void)
 	return 0;
 
 out_class:
-	class_destroy(tb_class);
+	class_unregister(&tb_class);
 out_chrdev:
 	unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);
 
@@ -582,9 +579,9 @@ static int __init sbprof_tb_init(void)
 
 static void __exit sbprof_tb_cleanup(void)
 {
-	device_destroy(tb_class, MKDEV(SBPROF_TB_MAJOR, 0));
+	device_destroy(&tb_class, MKDEV(SBPROF_TB_MAJOR, 0));
 	unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);
-	class_destroy(tb_class);
+	class_unregister(&tb_class);
 }
 
 module_init(sbprof_tb_init);