[PATCH] IB/hfi1: Correct issues with sc5 computation

[Mike Marciniszyn <mike.marciniszyn@intel.com>]

commit 896ce45da2c2f4abc508d443fdecde7de0b3fa7e upstream.

There are several computatations of the sc in the
ud receive routine.

Besides the code duplication, all are wrong when the
sc is greater than 15.   In that case the code incorrectly
or's a 1 into the computed sc instead of 1 shifted left
by 4.

Fix precomputed sc5 by using an already implemented routine
hdr2sc() and deleting flawed duplicated code.

[ported from 896ce45da2c to linux-4.6.y]

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@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/staging/rdma/hfi1/ud.c |   23 +++--------------------
 1 file changed, 3 insertions(+), 20 deletions(-)

diff --git a/drivers/staging/rdma/hfi1/ud.c b/drivers/staging/rdma/hfi1/ud.c
index ae8a70f..23e60fe 100644
--- a/drivers/staging/rdma/hfi1/ud.c
+++ b/drivers/staging/rdma/hfi1/ud.c
@@ -678,8 +678,7 @@ void hfi1_ud_rcv(struct hfi1_packet *packet)
 	u32 tlen = packet->tlen;
 	struct rvt_qp *qp = packet->qp;
 	bool has_grh = rcv_flags & HFI1_HAS_GRH;
-	bool sc4_bit = has_sc4_bit(packet);
-	u8 sc;
+	u8 sc5 = hdr2sc((struct hfi1_message_header *)hdr, packet->rhf);
 	u32 bth1;
 	int is_mcast;
 	struct ib_grh *grh = NULL;
@@ -697,10 +696,8 @@ void hfi1_ud_rcv(struct hfi1_packet *packet)
 		 */
 		struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
 		u32 lqpn =  be32_to_cpu(ohdr->bth[1]) & RVT_QPN_MASK;
-		u8 sl, sc5;
+		u8 sl;
 
-		sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
-		sc5 |= sc4_bit;
 		sl = ibp->sc_to_sl[sc5];
 
 		process_becn(ppd, sl, 0, lqpn, 0, IB_CC_SVCTYPE_UD);
@@ -717,10 +714,6 @@ void hfi1_ud_rcv(struct hfi1_packet *packet)
 
 	if (!is_mcast && (opcode != IB_OPCODE_CNP) && bth1 & HFI1_FECN_SMASK) {
 		u16 slid = be16_to_cpu(hdr->lrh[3]);
-		u8 sc5;
-
-		sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
-		sc5 |= sc4_bit;
 
 		return_cnp(ibp, qp, src_qp, pkey, dlid, slid, sc5, grh);
 	}
@@ -745,10 +738,6 @@ void hfi1_ud_rcv(struct hfi1_packet *packet)
 		if (qp->ibqp.qp_num > 1) {
 			struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
 			u16 slid;
-			u8 sc5;
-
-			sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
-			sc5 |= sc4_bit;
 
 			slid = be16_to_cpu(hdr->lrh[3]);
 			if (unlikely(rcv_pkey_check(ppd, pkey, sc5, slid))) {
@@ -790,10 +779,6 @@ void hfi1_ud_rcv(struct hfi1_packet *packet)
 		/* Received on QP0, and so by definition, this is an SMP */
 		struct opa_smp *smp = (struct opa_smp *)data;
 		u16 slid = be16_to_cpu(hdr->lrh[3]);
-		u8 sc5;
-
-		sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
-		sc5 |= sc4_bit;
 
 		if (opa_smp_check(ibp, pkey, sc5, qp, slid, smp))
 			goto drop;
@@ -890,9 +875,7 @@ void hfi1_ud_rcv(struct hfi1_packet *packet)
 	}
 
 	wc.slid = be16_to_cpu(hdr->lrh[3]);
-	sc = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
-	sc |= sc4_bit;
-	wc.sl = ibp->sc_to_sl[sc];
+	wc.sl = ibp->sc_to_sl[sc5];
 
 	/*
 	 * Save the LMC lower bits if the destination LID is a unicast LID.