s390/zcrypt: Fix wrong dispatching for control domain CPRBs

The zcrypt device driver does not handle CPRBs which address
a control domain correctly. This fix introduces a workaround:
The domain field of the request CPRB is checked if there is
a valid domain value in there. If this is true and the value
is a control only domain (a domain which is enabled in the
crypto config ADM mask but disabled in the AQM mask) the
CPRB is forwarded to the default usage domain. If there is
no default domain, the request is rejected with an ENODEV.

This fix is important for maintaining crypto adapters. For
example one LPAR can use a crypto adapter domain ('Control
and Usage') but another LPAR needs to be able to maintain
this adapter domain ('Control'). Scenarios like this did
not work properly and the patch enables this.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index 15a98a6..6f3cf37 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -251,6 +251,9 @@ void ap_wait(enum ap_wait wait);
 void ap_request_timeout(struct timer_list *t);
 void ap_bus_force_rescan(void);
 
+int ap_test_config_usage_domain(unsigned int domain);
+int ap_test_config_ctrl_domain(unsigned int domain);
+
 void ap_queue_init_reply(struct ap_queue *aq, struct ap_message *ap_msg);
 struct ap_queue *ap_queue_create(ap_qid_t qid, int device_type);
 void ap_queue_prepare_remove(struct ap_queue *aq);