IB/hfi1: Delay the release of destination mr for TID RDMA WRITE DATA

The reference of destination memory region is first obtained when TID RDMA
WRITE request is first received on the responder side. This reference is
released once all TID RDMA WRITE RESP packets are sent to the requester
side, even though not all TID RDMA WRITE DATA packets may have been
received. This early release will especially be undesired if the software
needs to access the destination memory before the last data packet is
received.

This patch delays the release of the MR until all TID RDMA DATA packets
have been received. A helper function to release the reference is also
created to simplify the code.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 4 insertions, 12 deletions

diff --git a/drivers/infiniband/hw/hfi1/tid_rdma.c b/drivers/infiniband/hw/hfi1/tid_rdma.c
index fdda33aca77f..145dd3348fdd 100644
--- a/drivers/infiniband/hw/hfi1/tid_rdma.c
+++ b/drivers/infiniband/hw/hfi1/tid_rdma.c
@@ -2036,10 +2036,7 @@ static int tid_rdma_rcv_error(struct hfi1_packet *packet,
 		if (psn != e->psn || len != req->total_len)
 			goto unlock;
 
-		if (e->rdma_sge.mr) {
-			rvt_put_mr(e->rdma_sge.mr);
-			e->rdma_sge.mr = NULL;
-		}
+		release_rdma_sge_mr(e);
 
 		rkey = be32_to_cpu(reth->rkey);
 		vaddr = get_ib_reth_vaddr(reth);
@@ -2285,10 +2282,7 @@ void hfi1_rc_rcv_tid_rdma_read_req(struct hfi1_packet *packet)
 		update_ack_queue(qp, next);
 	}
 	e = &qp->s_ack_queue[qp->r_head_ack_queue];
-	if (e->rdma_sge.mr) {
-		rvt_put_mr(e->rdma_sge.mr);
-		e->rdma_sge.mr = NULL;
-	}
+	release_rdma_sge_mr(e);
 
 	rkey = be32_to_cpu(reth->rkey);
 	qp->r_len = len;
@@ -3751,10 +3745,7 @@ void hfi1_rc_rcv_tid_rdma_write_req(struct hfi1_packet *packet)
 		goto update_head;
 	}
 
-	if (e->rdma_sge.mr) {
-		rvt_put_mr(e->rdma_sge.mr);
-		e->rdma_sge.mr = NULL;
-	}
+	release_rdma_sge_mr(e);
 
 	/* The length needs to be in multiples of PAGE_SIZE */
 	if (!len || len & ~PAGE_MASK)
@@ -4347,6 +4338,7 @@ void hfi1_rc_rcv_tid_rdma_write_data(struct hfi1_packet *packet)
 		priv->r_tid_ack = priv->r_tid_tail;
 
 	if (opcode == TID_OP(WRITE_DATA_LAST)) {
+		release_rdma_sge_mr(e);
 		for (next = priv->r_tid_tail + 1; ; next++) {
 			if (next > rvt_size_atomic(&dev->rdi))
 				next = 0;