diff --git a/drivers/s390/crypto/Makefile b/drivers/s390/crypto/Makefile
index b8ab18676e69..d0549fc87247 100644
--- a/drivers/s390/crypto/Makefile
+++ b/drivers/s390/crypto/Makefile
@@ -3,9 +3,9 @@
 #
 
 ap-objs := ap_bus.o
-# zcrypt_api depends on ap
-obj-$(CONFIG_ZCRYPT) += ap.o zcrypt_api.o
-# msgtype* depend on zcrypt_api
-obj-$(CONFIG_ZCRYPT) += zcrypt_msgtype6.o zcrypt_msgtype50.o
-# adapter drivers depend on ap, zcrypt_api and msgtype*
+obj-$(subst m,y,$(CONFIG_ZCRYPT)) += ap.o
+# zcrypt_api.o and zcrypt_msgtype*.o depend on ap.o
+zcrypt-objs := zcrypt_api.o zcrypt_msgtype6.o zcrypt_msgtype50.o
+obj-$(CONFIG_ZCRYPT) += zcrypt.o
+# adapter drivers depend on ap.o and zcrypt.o
 obj-$(CONFIG_ZCRYPT) += zcrypt_pcixcc.o zcrypt_cex2a.o zcrypt_cex4.o
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index cac919d63b43..c695219d70c4 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -62,6 +62,7 @@ MODULE_ALIAS_CRYPTO("z90crypt");
  * Module parameter
  */
 int ap_domain_index = -1;	/* Adjunct Processor Domain Index */
+static DEFINE_SPINLOCK(ap_domain_lock);
 module_param_named(domain, ap_domain_index, int, S_IRUSR|S_IRGRP);
 MODULE_PARM_DESC(domain, "domain index for ap devices");
 EXPORT_SYMBOL(ap_domain_index);
@@ -1481,7 +1482,21 @@ static ssize_t ap_domain_show(struct bus_type *bus, char *buf)
 	return snprintf(buf, PAGE_SIZE, "%d\n", ap_domain_index);
 }
 
-static BUS_ATTR(ap_domain, 0444, ap_domain_show, NULL);
+static ssize_t ap_domain_store(struct bus_type *bus,
+			       const char *buf, size_t count)
+{
+	int domain;
+
+	if (sscanf(buf, "%i\n", &domain) != 1 ||
+	    domain < 0 || domain > ap_max_domain_id)
+		return -EINVAL;
+	spin_lock_bh(&ap_domain_lock);
+	ap_domain_index = domain;
+	spin_unlock_bh(&ap_domain_lock);
+	return count;
+}
+
+static BUS_ATTR(ap_domain, 0644, ap_domain_show, ap_domain_store);
 
 static ssize_t ap_control_domain_mask_show(struct bus_type *bus, char *buf)
 {
@@ -1623,9 +1638,12 @@ static int ap_select_domain(void)
 	 * the "domain=" parameter or the domain with the maximum number
 	 * of devices.
 	 */
-	if (ap_domain_index >= 0)
+	spin_lock_bh(&ap_domain_lock);
+	if (ap_domain_index >= 0) {
 		/* Domain has already been selected. */
+		spin_unlock_bh(&ap_domain_lock);
 		return 0;
+	}
 	best_domain = -1;
 	max_count = 0;
 	for (i = 0; i < AP_DOMAINS; i++) {
@@ -1647,8 +1665,10 @@ static int ap_select_domain(void)
 	}
 	if (best_domain >= 0){
 		ap_domain_index = best_domain;
+		spin_unlock_bh(&ap_domain_lock);
 		return 0;
 	}
+	spin_unlock_bh(&ap_domain_lock);
 	return -ENODEV;
 }
 
@@ -1677,6 +1697,8 @@ static void ap_scan_bus(struct work_struct *unused)
 	if (ap_select_domain() != 0)
 		goto out;
 
+
+	spin_lock_bh(&ap_domain_lock);
 	for (i = 0; i < AP_DEVICES; i++) {
 		qid = AP_MKQID(i, ap_domain_index);
 		dev = bus_find_device(&ap_bus_type, NULL,
@@ -1753,6 +1775,7 @@ static void ap_scan_bus(struct work_struct *unused)
 			continue;
 		}
 	}
+	spin_unlock_bh(&ap_domain_lock);
 out:
 	mod_timer(&ap_config_timer, jiffies + ap_config_time * HZ);
 }
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 5d3d04c040c2..7f61ae1b0b93 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -45,6 +45,7 @@
 #include "zcrypt_api.h"
 
 #include "zcrypt_msgtype6.h"
+#include "zcrypt_msgtype50.h"
 
 /*
  * Module description.
@@ -1459,6 +1460,8 @@ int __init zcrypt_api_init(void)
 		goto out_misc;
 	}
 
+	zcrypt_msgtype6_init();
+	zcrypt_msgtype50_init();
 	return 0;
 
 out_misc:
@@ -1472,11 +1475,13 @@ out:
  *
  * The module termination code.
  */
-void zcrypt_api_exit(void)
+void __exit zcrypt_api_exit(void)
 {
 	remove_proc_entry("driver/z90crypt", NULL);
 	misc_deregister(&zcrypt_misc_device);
 	zcrypt_debug_exit();
+	zcrypt_msgtype6_exit();
+	zcrypt_msgtype50_exit();
 }
 
 module_init(zcrypt_api_init);
diff --git a/drivers/s390/crypto/zcrypt_msgtype50.c b/drivers/s390/crypto/zcrypt_msgtype50.c
index eedfaa2cf715..7bafba83390a 100644
--- a/drivers/s390/crypto/zcrypt_msgtype50.c
+++ b/drivers/s390/crypto/zcrypt_msgtype50.c
@@ -518,16 +518,12 @@ static struct zcrypt_ops zcrypt_msgtype50_ops = {
 	.variant = MSGTYPE50_VARIANT_DEFAULT,
 };
 
-int __init zcrypt_msgtype50_init(void)
+void __init zcrypt_msgtype50_init(void)
 {
 	zcrypt_msgtype_register(&zcrypt_msgtype50_ops);
-	return 0;
 }
 
 void __exit zcrypt_msgtype50_exit(void)
 {
 	zcrypt_msgtype_unregister(&zcrypt_msgtype50_ops);
 }
-
-module_init(zcrypt_msgtype50_init);
-module_exit(zcrypt_msgtype50_exit);
diff --git a/drivers/s390/crypto/zcrypt_msgtype50.h b/drivers/s390/crypto/zcrypt_msgtype50.h
index 0a66e4aeeb50..eeb41c0f34ae 100644
--- a/drivers/s390/crypto/zcrypt_msgtype50.h
+++ b/drivers/s390/crypto/zcrypt_msgtype50.h
@@ -35,7 +35,7 @@
 
 #define MSGTYPE_ADJUSTMENT		0x08  /*type04 extension (not needed in type50)*/
 
-int zcrypt_msgtype50_init(void);
+void zcrypt_msgtype50_init(void);
 void zcrypt_msgtype50_exit(void);
 
 #endif /* _ZCRYPT_MSGTYPE50_H_ */
diff --git a/drivers/s390/crypto/zcrypt_msgtype6.c b/drivers/s390/crypto/zcrypt_msgtype6.c
index 21959719daef..f71949685ff5 100644
--- a/drivers/s390/crypto/zcrypt_msgtype6.c
+++ b/drivers/s390/crypto/zcrypt_msgtype6.c
@@ -1145,12 +1145,11 @@ static struct zcrypt_ops zcrypt_msgtype6_ep11_ops = {
 	.send_ep11_cprb = zcrypt_msgtype6_send_ep11_cprb,
 };
 
-int __init zcrypt_msgtype6_init(void)
+void __init zcrypt_msgtype6_init(void)
 {
 	zcrypt_msgtype_register(&zcrypt_msgtype6_norng_ops);
 	zcrypt_msgtype_register(&zcrypt_msgtype6_ops);
 	zcrypt_msgtype_register(&zcrypt_msgtype6_ep11_ops);
-	return 0;
 }
 
 void __exit zcrypt_msgtype6_exit(void)
@@ -1159,6 +1158,3 @@ void __exit zcrypt_msgtype6_exit(void)
 	zcrypt_msgtype_unregister(&zcrypt_msgtype6_ops);
 	zcrypt_msgtype_unregister(&zcrypt_msgtype6_ep11_ops);
 }
-
-module_init(zcrypt_msgtype6_init);
-module_exit(zcrypt_msgtype6_exit);
diff --git a/drivers/s390/crypto/zcrypt_msgtype6.h b/drivers/s390/crypto/zcrypt_msgtype6.h
index 207247570623..5750c4377bfa 100644
--- a/drivers/s390/crypto/zcrypt_msgtype6.h
+++ b/drivers/s390/crypto/zcrypt_msgtype6.h
@@ -165,7 +165,7 @@ static inline void rng_type6CPRB_msgX(struct ap_device *ap_dev,
 	ap_msg->length = sizeof(*msg);
 }
 
-int zcrypt_msgtype6_init(void);
+void zcrypt_msgtype6_init(void);
 void zcrypt_msgtype6_exit(void);
 
 #endif /* _ZCRYPT_MSGTYPE6_H_ */