IB/hfi1: Compute BTH only for RDMA_WRITE_LAST/SEND_LAST packet

In hfi1_rc_rcv(), BTH is computed for all packets received.
However, it's only used for packets received with opcodes
RDMA_WRITE_LAST and SEND_LAST, and it is a costly operation.

Compute BTH only in the RDMA_WRITE_LAST/SEND_LAST code path
and let the compiler handle endianness conversion for bitwise
operations.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hfi1/rc.c

@@ -2035,7 +2035,6 @@ void hfi1_rc_rcv(struct hfi1_packet *packet)
 	struct rvt_qp *qp = packet->qp;
 	struct hfi1_ibport *ibp = rcd_to_iport(rcd);
 	struct ib_other_headers *ohdr = packet->ohdr;
-	u32 bth0 = be32_to_cpu(ohdr->bth[0]);
 	u32 opcode = packet->opcode;
 	u32 hdrsize = packet->hlen;
 	u32 psn = ib_bth_get_psn(packet->ohdr);
@@ -2233,7 +2232,7 @@ send_last:
 		wc.port_num = 0;
 		/* Signal completion event if the solicited bit is set. */
 		rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
-			     (bth0 & IB_BTH_SOLICITED) != 0);
+			     ib_bth_is_solicited(ohdr));
 		break;
 
 	case OP(RDMA_WRITE_ONLY):

drivers/infiniband/hw/hfi1/uc.c

@@ -478,8 +478,7 @@ last_imm:
 		wc.port_num = 0;
 		/* Signal completion event if the solicited bit is set. */
 		rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
-			     (ohdr->bth[0] &
-			      cpu_to_be32(IB_BTH_SOLICITED)) != 0);
+			     ib_bth_is_solicited(ohdr));
 		break;
 
 	case OP(RDMA_WRITE_FIRST):

drivers/infiniband/hw/hfi1/ud.c

@@ -1045,8 +1045,7 @@ void hfi1_ud_rcv(struct hfi1_packet *packet)
 	wc.port_num = qp->port_num;
 	/* Signal completion event if the solicited bit is set. */
 	rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
-		     (ohdr->bth[0] &
-		      cpu_to_be32(IB_BTH_SOLICITED)) != 0);
+		     ib_bth_is_solicited(ohdr));
 	return;
 
 drop: