[PATCH for-next 21/23] IB/hfi1: Enable TID RDMA WRITE protocol

[Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>]

From: Kaike Wan <kaike.wan@xxxxxxxxx>

This patch enables TID RDMA WRITE protocol by converting a qualified
RDMA WRITE request into a TID RDMA WRITE request internally:
(1) The TID RDMA cability must be enabled;
(2) The request must start on a 4K page boundary;
(3) The request length must be a multiple of 4K and must be larger or
equal to 256K.

Signed-off-by: Mitko Haralanov <mitko.haralanov@xxxxxxxxx>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Kaike Wan <kaike.wan@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
---
 drivers/infiniband/hw/hfi1/tid_rdma.c |   22 ++++++++++++++++++++++
 drivers/infiniband/hw/hfi1/tid_rdma.h |    3 ++-
 2 files changed, 24 insertions(+), 1 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/tid_rdma.c b/drivers/infiniband/hw/hfi1/tid_rdma.c
index 7ea8e21..fc40eb3 100644
--- a/drivers/infiniband/hw/hfi1/tid_rdma.c
+++ b/drivers/infiniband/hw/hfi1/tid_rdma.c
@@ -3318,6 +3318,18 @@ void setup_tid_rdma_wqe(struct rvt_qp *qp, struct rvt_swqe *wqe)
 			new_opcode = IB_WR_TID_RDMA_READ;
 			do_tid_rdma = true;
 		}
+	} else if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
+		/*
+		 * TID RDMA is enabled for this RDMA WRITE request iff:
+		 *   1. The remote address is page-aligned,
+		 *   2. The length is larger than the minimum segment size,
+		 *   3. The length is page-multiple.
+		 */
+		if (!(wqe->rdma_wr.remote_addr & ~PAGE_MASK) &&
+		    !(wqe->length & ~PAGE_MASK)) {
+			new_opcode = IB_WR_TID_RDMA_WRITE;
+			do_tid_rdma = true;
+		}
 	}
 
 	if (do_tid_rdma) {
@@ -3334,12 +3346,22 @@ void setup_tid_rdma_wqe(struct rvt_qp *qp, struct rvt_swqe *wqe)
 			priv->tid_req.n_flows = remote->max_read;
 			qpriv->tid_r_reqs++;
 			wqe->lpsn += rvt_div_round_up_mtu(qp, wqe->length) - 1;
+		} else {
+			wqe->lpsn += priv->tid_req.total_segs - 1;
+			atomic_inc(&qpriv->n_requests);
 		}
 
 		priv->tid_req.cur_seg = 0;
 		priv->tid_req.comp_seg = 0;
 		priv->tid_req.ack_seg = 0;
 		priv->tid_req.state = TID_REQUEST_INACTIVE;
+		/*
+		 * Reset acked_tail.
+		 * TID RDMA READ does not have ACKs so it does not
+		 * update the pointer. We have to reset it so TID RDMA
+		 * WRITE does not get confused.
+		 */
+		priv->tid_req.acked_tail = priv->tid_req.setup_head;
 		trace_hfi1_tid_req_setup_tid_wqe(qp, 1, wqe->wr.opcode,
 						 wqe->psn, wqe->lpsn,
 						 &priv->tid_req);
diff --git a/drivers/infiniband/hw/hfi1/tid_rdma.h b/drivers/infiniband/hw/hfi1/tid_rdma.h
index 4446818..53ab24e 100644
--- a/drivers/infiniband/hw/hfi1/tid_rdma.h
+++ b/drivers/infiniband/hw/hfi1/tid_rdma.h
@@ -266,7 +266,8 @@ static inline void hfi1_setup_tid_rdma_wqe(struct rvt_qp *qp,
 					   struct rvt_swqe *wqe)
 {
 	if (wqe->priv &&
-	    wqe->wr.opcode == IB_WR_RDMA_READ &&
+	    (wqe->wr.opcode == IB_WR_RDMA_READ ||
+	     wqe->wr.opcode == IB_WR_RDMA_WRITE) &&
 	    wqe->length >= TID_RDMA_MIN_SEGMENT_SIZE)
 		setup_tid_rdma_wqe(qp, wqe);
 }