RDMA/rxe: Generate error completion for error requester QP state

As per IBTA specification, all subsequent WQEs while QP is in error state
should be completed with a flush error.

Here we check QP_STATE_ERROR after req_next_wqe() so that rxe_completer()
has chance to be called where it will set CQ state to FLUSH ERROR and the
completion can associate with its WQE.

Link: https://lore.kernel.org/r/1658307368-1851-3-git-send-email-lizhijian@fujitsu.com
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: zhijianli88

Diff for: drivers/infiniband/sw/rxe/rxe_req.c

@@ -635,9 +635,20 @@ int rxe_requester(void *arg)
 	if (!rxe_get(qp))
 		return -EAGAIN;
 
-	if (unlikely(!qp->valid || qp->req.state == QP_STATE_ERROR))
+	if (unlikely(!qp->valid))
 		goto exit;
 
+	if (unlikely(qp->req.state == QP_STATE_ERROR)) {
+		wqe = req_next_wqe(qp);
+		if (wqe)
+			/*
+			 * Generate an error completion for error qp state
+			 */
+			goto err;
+		else
+			goto exit;
+	}
+
 	if (unlikely(qp->req.state == QP_STATE_RESET)) {
 		qp->req.wqe_index = queue_get_consumer(q,
 						QUEUE_TYPE_FROM_CLIENT);