IB/ehca: Use named constant for max mtu

Define and use a constant EHCA_MAX_MTU instead hardcoded value.
Signed-off-by: NHoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ehca/ehca_av.c

@@ -118,8 +118,7 @@ struct ib_ah *ehca_create_ah(struct ib_pd *pd, struct ib_ah_attr *ah_attr)
 		}
 		memcpy(&av->av.grh.word_1, &gid, sizeof(gid));
 	}
-	/* for the time being we use a hard coded PMTU of 2048 Bytes */
-	av->av.pmtu = 4;
+	av->av.pmtu = EHCA_MAX_MTU;
 
 	/* dgid comes in grh.word_3 */
 	memcpy(&av->av.grh.word_3, &ah_attr->grh.dgid,
@@ -193,7 +192,7 @@ int ehca_modify_ah(struct ib_ah *ah, struct ib_ah_attr *ah_attr)
 		memcpy(&new_ehca_av.grh.word_1, &gid, sizeof(gid));
 	}
 
-	new_ehca_av.pmtu = 4; /* see also comment in create_ah() */
+	new_ehca_av.pmtu = EHCA_MAX_MTU;
 
 	memcpy(&new_ehca_av.grh.word_3, &ah_attr->grh.dgid,
 	       sizeof(ah_attr->grh.dgid));

drivers/infiniband/hw/ehca/hipz_hw.h

@@ -45,6 +45,8 @@
 
 #include "ehca_tools.h"
 
+#define EHCA_MAX_MTU 4
+
 /* QP Table Entry Memory Map */
 struct hipz_qptemm {
 	u64 qpx_hcr;