Link WQEs properly

Fix posting of the first work request for memfree hardware.
Also simplify code for Tavor-mode hardware.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

4 files changed, 36 insertions, 34 deletions

diff --git a/ChangeLog b/ChangeLog
index d4cdc23..6b45dc1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2005-09-13  Roland Dreier  <roland@cisco.com>
+
+	* src/qp.c (mthca_tavor_post_send, mthca_tavor_post_recv,
+	mthca_arbel_post_send), src/srq.c (mthca_tavor_post_srq_recv):
+	Apply Michael S. Tsirkin's patch to fix linking of WQEs on
+	mem-free HCAs.  While we're at it, simplify the Tavor WQE posting
+	code as well -- there's no need for a conditional, just always lik
+	the previous WQE.
+
 2005-09-07  Roland Dreier  <roland@cisco.com>
 
 	* src/mthca.h: Get rid of ntohll() and htonll() now that
diff --git a/src/qp.c b/src/qp.c
index 49512bf..a328c13 100644
--- a/src/qp.c
+++ b/src/qp.c
@@ -259,15 +259,13 @@ int mthca_tavor_post_send(struct ibv_qp *ibqp, struct ibv_send_wr *wr,
 			goto out;
 		}
 
-		if (prev_wqe) {
-			((struct mthca_next_seg *) prev_wqe)->nda_op =
-				htonl(((ind << qp->sq.wqe_shift) +
-				       qp->send_wqe_offset) |
-				      mthca_opcode[wr->opcode]);
-
-			((struct mthca_next_seg *) prev_wqe)->ee_nds =
-				htonl((size0 ? 0 : MTHCA_NEXT_DBD) | size);
-		}
+		((struct mthca_next_seg *) prev_wqe)->nda_op =
+			htonl(((ind << qp->sq.wqe_shift) +
+			       qp->send_wqe_offset) |
+			      mthca_opcode[wr->opcode]);
+
+		((struct mthca_next_seg *) prev_wqe)->ee_nds =
+			htonl((size0 ? 0 : MTHCA_NEXT_DBD) | size);
 
 		if (!size0) {
 			size0 = size;
@@ -353,12 +351,10 @@ int mthca_tavor_post_recv(struct ibv_qp *ibqp, struct ibv_recv_wr *wr,
 
 		qp->wrid[ind] = wr->wr_id;
 
-		if (prev_wqe) {
-			((struct mthca_next_seg *) prev_wqe)->nda_op =
-				htonl((ind << qp->rq.wqe_shift) | 1);
-			((struct mthca_next_seg *) prev_wqe)->ee_nds =
-				htonl(MTHCA_NEXT_DBD | size);
-		}
+		((struct mthca_next_seg *) prev_wqe)->nda_op =
+			htonl((ind << qp->rq.wqe_shift) | 1);
+		((struct mthca_next_seg *) prev_wqe)->ee_nds =
+			htonl(MTHCA_NEXT_DBD | size);
 
 		if (!size0)
 			size0 = size;
@@ -562,15 +558,13 @@ int mthca_arbel_post_send(struct ibv_qp *ibqp, struct ibv_send_wr *wr,
 			goto out;
 		}
 
-		if (prev_wqe) {
-			((struct mthca_next_seg *) prev_wqe)->nda_op =
-				htonl(((ind << qp->sq.wqe_shift) +
-				       qp->send_wqe_offset) |
-				      mthca_opcode[wr->opcode]);
-			mb();
-			((struct mthca_next_seg *) prev_wqe)->ee_nds =
-				htonl(MTHCA_NEXT_DBD | size);
-		}
+		((struct mthca_next_seg *) prev_wqe)->nda_op =
+			htonl(((ind << qp->sq.wqe_shift) +
+			       qp->send_wqe_offset) |
+			      mthca_opcode[wr->opcode]);
+		mb();
+		((struct mthca_next_seg *) prev_wqe)->ee_nds =
+			htonl(MTHCA_NEXT_DBD | size);
 
 		if (!size0) {
 			size0 = size;
@@ -767,6 +761,9 @@ int mthca_alloc_qp_buf(struct ibv_pd *pd, struct ibv_qp_cap *cap,
 		}
 	}
 
+	qp->sq.last = get_send_wqe(qp, qp->sq.max - 1);
+	qp->rq.last = get_recv_wqe(qp, qp->sq.max - 1);
+
 	return 0;
 }
 
diff --git a/src/srq.c b/src/srq.c
index 9c51dcb..84cd2a4 100644
--- a/src/srq.c
+++ b/src/srq.c
@@ -142,13 +142,11 @@ int mthca_tavor_post_srq_recv(struct ibv_srq *ibsrq,
 			((struct mthca_data_seg *) wqe)->addr = 0;
 		}
 
-		if (prev_wqe) {
-			((struct mthca_next_seg *) prev_wqe)->nda_op =
-				htonl((ind << srq->wqe_shift) | 1);
-			mb();
-			((struct mthca_next_seg *) prev_wqe)->ee_nds =
-				htonl(MTHCA_NEXT_DBD);
-		}
+		((struct mthca_next_seg *) prev_wqe)->nda_op =
+			htonl((ind << srq->wqe_shift) | 1);
+		mb();
+		((struct mthca_next_seg *) prev_wqe)->ee_nds =
+			htonl(MTHCA_NEXT_DBD);
 
 		srq->wrid[ind]  = wr->wr_id;
 		srq->first_free = next_ind;
@@ -294,6 +292,7 @@ int mthca_alloc_srq_buf(struct ibv_pd *pd, struct ibv_srq_attr *attr,
 
 	srq->first_free = 0;
 	srq->last_free  = srq->max - 1;
+	srq->last       = get_wqe(srq, srq->max - 1);
 
 	return 0;
 }
diff --git a/src/verbs.c b/src/verbs.c
index e8cfc22..3fe7e80 100644
--- a/src/verbs.c
+++ b/src/verbs.c
@@ -306,7 +306,6 @@ struct ibv_srq *mthca_create_srq(struct ibv_pd *pd,
 
 	srq->max     = align_queue_size(pd->context, attr->attr.max_wr, 1);
 	srq->max_gs  = attr->attr.max_sge;
-	srq->last    = NULL;
 	srq->counter = 0;
 
 	if (mthca_alloc_srq_buf(pd, &attr->attr, srq))
@@ -413,14 +412,12 @@ struct ibv_qp *mthca_create_qp(struct ibv_pd *pd, struct ibv_qp_init_attr *attr)
 	qp->sq.last_comp = qp->sq.max - 1;
 	qp->sq.head    	 = 0;
 	qp->sq.tail    	 = 0;
-	qp->sq.last      = NULL;
 
 	qp->rq.max       = align_queue_size(pd->context, attr->cap.max_recv_wr, 0);
 	qp->rq.next_ind	 = 0;
 	qp->rq.last_comp = qp->rq.max - 1;
 	qp->rq.head    	 = 0;
 	qp->rq.tail    	 = 0;
-	qp->rq.last      = NULL;
 
 	if (mthca_alloc_qp_buf(pd, &attr->cap, qp))
 		goto err;