IB/rdmavt, IB/hfi1, IB/qib: Add inlines for mtu division

Add rvt_div_round_up_mtu() and rvt_div_mtu() routines to
do the computation based on the pmtu and the log_pmtu.

Change divides in qib, hfi1 to use the new inlines.
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/rc.c

@@ -2377,8 +2377,7 @@ void hfi1_rc_rcv(struct hfi1_packet *packet)
 			 * Update the next expected PSN.  We add 1 later
 			 * below, so only add the remainder here.
 			 */
-			if (len > pmtu)
-				qp->r_psn += (len - 1) / pmtu;
+			qp->r_psn += rvt_div_mtu(qp, len - 1);
 		} else {
 			e->rdma_sge.mr = NULL;
 			e->rdma_sge.vaddr = NULL;

drivers/infiniband/hw/qib/qib_rc.c

@@ -2079,8 +2079,7 @@ void qib_rc_rcv(struct qib_ctxtdata *rcd, struct ib_header *hdr,
 			 * Update the next expected PSN.  We add 1 later
 			 * below, so only add the remainder here.
 			 */
-			if (len > pmtu)
-				qp->r_psn += (len - 1) / pmtu;
+			qp->r_psn += rvt_div_mtu(qp, len - 1);
 		} else {
 			e->rdma_sge.mr = NULL;
 			e->rdma_sge.vaddr = NULL;

include/rdma/rdmavt_qp.h

@@ -582,6 +582,28 @@ static inline void rvt_qp_swqe_complete(
 	}
 }
 
+/**
+ * @qp - the qp pair
+ * @len - the length
+ *
+ * Perform a shift based mtu round up divide
+ */
+static inline u32 rvt_div_round_up_mtu(struct rvt_qp *qp, u32 len)
+{
+	return (len + qp->pmtu - 1) >> qp->log_pmtu;
+}
+
+/**
+ * @qp - the qp pair
+ * @len - the length
+ *
+ * Perform a shift based mtu divide
+ */
+static inline u32 rvt_div_mtu(struct rvt_qp *qp, u32 len)
+{
+	return len >> qp->log_pmtu;
+}
+
 extern const int  ib_rvt_state_ops[];
 
 struct rvt_dev_info;