[S390] kvm: use console_initcall() to initialize s390 virtio console

Use a console_initcall() to initialize the s390 virtio console and
clean up s390 console initialization in setup.c.

Signed-off-by: Hendrik Brueckner <[e-mail]>
Tested-by: Christian Borntraeger <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

arch/s390/include/asm/kvm_virtio.h

···
  * This is pagesize for historical reasons. */
 #define KVM_S390_VIRTIO_RING_ALIGN	4096
 
-#ifdef __KERNEL__
-/* early virtio console setup */
-#ifdef CONFIG_S390_GUEST
-extern void s390_virtio_console_init(void);
-#else
-static inline void s390_virtio_console_init(void)
-{
-}
-#endif /* CONFIG_VIRTIO_CONSOLE */
-#endif /* __KERNEL__ */
 #endif

arch/s390/kernel/setup.c

···
 
 static void __init set_preferred_console(void)
 {
-	if (MACHINE_IS_KVM) {
+	if (MACHINE_IS_KVM)
 		add_preferred_console("hvc", 0, NULL);
-		s390_virtio_console_init();
-		return;
-	}
-
-	if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
+	else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
 		add_preferred_console("ttyS", 0, NULL);
-	if (CONSOLE_IS_3270)
+	else if (CONSOLE_IS_3270)
 		add_preferred_console("tty3270", 0, NULL);
 }
 

drivers/s390/kvm/kvm_virtio.c

···
 	return len;
 }
 
-void __init s390_virtio_console_init(void)
+static int __init s390_virtio_console_init(void)
 {
-	virtio_cons_early_init(early_put_chars);
+	if (!MACHINE_IS_KVM)
+		return -ENODEV;
+	return virtio_cons_early_init(early_put_chars);
 }
+console_initcall(s390_virtio_console_init);
+
 
 /*
  * We do this after core stuff, but before the drivers.