IB/hfi1: Remove dependence on qp->s_hdrwords

The s_hdrwords variable was used to indicate whether a
packet was already built on a previous iteration of the
send engine. This variable assumed the protection of the
QP's RVT_S_BUSY flag, which was required since the the
QP's s_lock was dropped just prior to the packet being
queued on the one of the egress mechanisms.

Support for multiple send engine instantiations require
that the field not be used due to concurency issues.
The ps.txreq signals the "already built" without the
potential concurency issues.

Fix by getting rid of all s_hdrword usage.   A wrapper
is added to test for the already built case that used to
use s_hdrwords.

What used to be stored in s_hdrwords is now in the txreq.
The PBC is not counted, but is added in the pio/sdma code
paths prior to posting the packet.

Reviewed-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 12 insertions, 15 deletions

diff --git a/drivers/infiniband/hw/hfi1/ud.c b/drivers/infiniband/hw/hfi1/ud.c
index beb5091eccca..6b5cd3a86be4 100644
--- a/drivers/infiniband/hw/hfi1/ud.c
+++ b/drivers/infiniband/hw/hfi1/ud.c
@@ -340,15 +340,15 @@ void hfi1_make_ud_req_9B(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 	extra_bytes = -wqe->length & 3;
 	nwords = ((wqe->length + extra_bytes) >> 2) + SIZE_OF_CRC;
 	/* header size in dwords LRH+BTH+DETH = (8+12+8)/4. */
-	qp->s_hdrwords = 7;
+	ps->s_txreq->hdr_dwords = 7;
 	if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
-		qp->s_hdrwords++;
+		ps->s_txreq->hdr_dwords++;
 
 	if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
 		grh = &ps->s_txreq->phdr.hdr.ibh.u.l.grh;
-		qp->s_hdrwords += hfi1_make_grh(ibp, grh,
-						rdma_ah_read_grh(ah_attr),
-						qp->s_hdrwords - 2, nwords);
+		ps->s_txreq->hdr_dwords +=
+			hfi1_make_grh(ibp, grh, rdma_ah_read_grh(ah_attr),
+				      ps->s_txreq->hdr_dwords - 2, nwords);
 		lrh0 = HFI1_LRH_GRH;
 		ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
 	} else {
@@ -381,7 +381,7 @@ void hfi1_make_ud_req_9B(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 		}
 	}
 	hfi1_make_bth_deth(qp, wqe, ohdr, &pkey, extra_bytes, false);
-	len = qp->s_hdrwords + nwords;
+	len = ps->s_txreq->hdr_dwords + nwords;
 
 	/* Setup the packet */
 	ps->s_txreq->phdr.hdr.hdr_type = HFI1_PKT_TYPE_9B;
@@ -405,12 +405,12 @@ void hfi1_make_ud_req_16B(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 	ppd = ppd_from_ibp(ibp);
 	ah_attr = &ibah_to_rvtah(wqe->ud_wr.ah)->attr;
 	/* header size in dwords 16B LRH+BTH+DETH = (16+12+8)/4. */
-	qp->s_hdrwords = 9;
+	ps->s_txreq->hdr_dwords = 9;
 	if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
-		qp->s_hdrwords++;
+		ps->s_txreq->hdr_dwords++;
 
 	/* SW provides space for CRC and LT for bypass packets. */
-	extra_bytes = hfi1_get_16b_padding((qp->s_hdrwords << 2),
+	extra_bytes = hfi1_get_16b_padding((ps->s_txreq->hdr_dwords << 2),
 					   wqe->length);
 	nwords = ((wqe->length + extra_bytes + SIZE_OF_LT) >> 2) + SIZE_OF_CRC;
 
@@ -428,8 +428,8 @@ void hfi1_make_ud_req_16B(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 			grd->sgid_index = 0;
 		}
 		grh = &ps->s_txreq->phdr.hdr.opah.u.l.grh;
-		qp->s_hdrwords += hfi1_make_grh(ibp, grh, grd,
-					qp->s_hdrwords - 4, nwords);
+		ps->s_txreq->hdr_dwords += hfi1_make_grh(ibp, grh, grd,
+					ps->s_txreq->hdr_dwords - 4, nwords);
 		ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
 		l4 = OPA_16B_L4_IB_GLOBAL;
 	} else {
@@ -452,7 +452,7 @@ void hfi1_make_ud_req_16B(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 
 	hfi1_make_bth_deth(qp, wqe, ohdr, &pkey, extra_bytes, true);
 	/* Convert dwords to flits */
-	len = (qp->s_hdrwords + nwords) >> 1;
+	len = (ps->s_txreq->hdr_dwords + nwords) >> 1;
 
 	/* Setup the packet */
 	ps->s_txreq->phdr.hdr.hdr_type = HFI1_PKT_TYPE_16B;
@@ -564,8 +564,6 @@ int hfi1_make_ud_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
 	priv->s_ahg->ahgcount = 0;
 	priv->s_ahg->ahgidx = 0;
 	priv->s_ahg->tx_flags = 0;
-	/* pbc */
-	ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2;
 
 	return 1;
 
@@ -580,7 +578,6 @@ bail:
 bail_no_tx:
 	ps->s_txreq = NULL;
 	qp->s_flags &= ~RVT_S_BUSY;
-	qp->s_hdrwords = 0;
 	return 0;
 }