RDMA/rtrs-clt: Set mininum limit when create QP

Currently rtrs when create_qp use a coarse numbers (bigger in general),
which leads to hardware create more resources which only waste memory
with no benefits.

- SERVICE con,
For max_send_wr/max_recv_wr, it's 2 times SERVICE_CON_QUEUE_DEPTH + 2

- IO con
For max_send_wr/max_recv_wr, it's sess->queue_depth * 3 + 1

Fixes: 6a98d71d ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20201217141915.56989-6-jinpu.wang@cloud.ionos.comSigned-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/ulp/rtrs/rtrs-clt.c

@@ -1511,7 +1511,7 @@ static void destroy_con(struct rtrs_clt_con *con)
 static int create_con_cq_qp(struct rtrs_clt_con *con)
 {
 	struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
-	u32 wr_queue_size;
+	u32 max_send_wr, max_recv_wr, cq_size;
 	int err, cq_vector;
 	struct rtrs_msg_rkey_rsp *rsp;
 
@@ -1523,7 +1523,8 @@ static int create_con_cq_qp(struct rtrs_clt_con *con)
 		 * + 2 for drain and heartbeat
 		 * in case qp gets into error state
 		 */
-		wr_queue_size = SERVICE_CON_QUEUE_DEPTH * 3 + 2;
+		max_send_wr = SERVICE_CON_QUEUE_DEPTH * 2 + 2;
+		max_recv_wr = SERVICE_CON_QUEUE_DEPTH * 2 + 2;
 		/* We must be the first here */
 		if (WARN_ON(sess->s.dev))
 			return -EINVAL;
@@ -1555,25 +1556,29 @@ static int create_con_cq_qp(struct rtrs_clt_con *con)
 
 		/* Shared between connections */
 		sess->s.dev_ref++;
-		wr_queue_size =
+		max_send_wr =
 			min_t(int, sess->s.dev->ib_dev->attrs.max_qp_wr,
 			      /* QD * (REQ + RSP + FR REGS or INVS) + drain */
 			      sess->queue_depth * 3 + 1);
+		max_recv_wr =
+			min_t(int, sess->s.dev->ib_dev->attrs.max_qp_wr,
+			      sess->queue_depth * 3 + 1);
 	}
 	/* alloc iu to recv new rkey reply when server reports flags set */
 	if (sess->flags == RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) {
-		con->rsp_ius = rtrs_iu_alloc(wr_queue_size, sizeof(*rsp),
+		con->rsp_ius = rtrs_iu_alloc(max_recv_wr, sizeof(*rsp),
 					      GFP_KERNEL, sess->s.dev->ib_dev,
 					      DMA_FROM_DEVICE,
 					      rtrs_clt_rdma_done);
 		if (!con->rsp_ius)
 			return -ENOMEM;
-		con->queue_size = wr_queue_size;
+		con->queue_size = max_recv_wr;
 	}
+	cq_size = max_send_wr + max_recv_wr;
 	cq_vector = con->cpu % sess->s.dev->ib_dev->num_comp_vectors;
 	err = rtrs_cq_qp_create(&sess->s, &con->c, sess->max_send_sge,
-				 cq_vector, wr_queue_size, wr_queue_size,
-				 wr_queue_size, IB_POLL_SOFTIRQ);
+				 cq_vector, cq_size, max_send_wr,
+				 max_recv_wr, IB_POLL_SOFTIRQ);
 	/*
 	 * In case of error we do not bother to clean previous allocations,
 	 * since destroy_con_cq_qp() must be called.