[S390] vmcp: disallow modular build

Change the tristate Kbuild option into a bool option so that the module
is either builtin or not available at all.
There have been too many cases where people were missing the 'vmcp'
device node and unable to send z/VM CP commands. So let's make sure
that on distros it will always be present.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/char/Kconfig

@@ -148,13 +148,12 @@ config VMLOGRDR
 	  This driver depends on the IUCV support driver.
 
 config VMCP
-	tristate "Support for the z/VM CP interface (VM only)"
+	bool "Support for the z/VM CP interface"
 	depends on S390
 	help
 	  Select this option if you want to be able to interact with the control
 	  program on z/VM
 
-
 config MONREADER
 	tristate "API for reading z/VM monitor service records"
 	depends on IUCV

drivers/s390/char/vmcp.c

 /*
- * Copyright IBM Corp. 2004,2007
+ * Copyright IBM Corp. 2004,2010
  * Interface implementation for communication with the z/VM control program
- * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
  *
+ * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
  *
  * z/VMs CP offers the possibility to issue commands via the diagnose code 8
  * this driver implements a character device that issues these commands and
  * returns the answer of CP.
-
+ *
  * The idea of this driver is based on cpint from Neale Ferguson and #CP in CMS
  */
 
-#define KMSG_COMPONENT "vmcp"
-#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
-
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
-#include <linux/module.h>
 #include <linux/slab.h>
 #include <asm/compat.h>
 #include <asm/cpcmd.h>
@@ -26,10 +22,6 @@
 #include <asm/uaccess.h>
 #include "vmcp.h"
 
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Christian Borntraeger <borntraeger@de.ibm.com>");
-MODULE_DESCRIPTION("z/VM CP interface");
-
 static debug_info_t *vmcp_debug;
 
 static int vmcp_open(struct inode *inode, struct file *file)
@@ -197,11 +189,8 @@ static int __init vmcp_init(void)
 {
 	int ret;
 
-	if (!MACHINE_IS_VM) {
-		pr_warning("The z/VM CP interface device driver cannot be "
-			   "loaded without z/VM\n");
-		return -ENODEV;
-	}
+	if (!MACHINE_IS_VM)
+		return 0;
 
 	vmcp_debug = debug_register("vmcp", 1, 1, 240);
 	if (!vmcp_debug)
@@ -214,19 +203,8 @@ static int __init vmcp_init(void)
 	}
 
 	ret = misc_register(&vmcp_dev);
-	if (ret) {
+	if (ret)
 		debug_unregister(vmcp_debug);
 	return ret;
-	}
-
-	return 0;
-}
-
-static void __exit vmcp_exit(void)
-{
-	misc_deregister(&vmcp_dev);
-	debug_unregister(vmcp_debug);
 }
-
-module_init(vmcp_init);
-module_exit(vmcp_exit);
+device_initcall(vmcp_init);