RDMA/rtrs: Introduce rtrs_post_send

Since the three functions share the similar logic, let's introduce one
common function for it.

Link: https://lore.kernel.org/r/20201023074353.21946-12-jinpu.wang@cloud.ionos.com
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/ulp/rtrs/rtrs.c

@@ -104,6 +104,22 @@ int rtrs_post_recv_empty(struct rtrs_con *con, struct ib_cqe *cqe)
 }
 EXPORT_SYMBOL_GPL(rtrs_post_recv_empty);
 
+static int rtrs_post_send(struct ib_qp *qp, struct ib_send_wr *head,
+			     struct ib_send_wr *wr)
+{
+	if (head) {
+		struct ib_send_wr *tail = head;
+
+		while (tail->next)
+			tail = tail->next;
+		tail->next = wr;
+	} else {
+		head = wr;
+	}
+
+	return ib_post_send(qp, head, NULL);
+}
+
 int rtrs_iu_post_send(struct rtrs_con *con, struct rtrs_iu *iu, size_t size,
 		       struct ib_send_wr *head)
 {
@@ -126,17 +142,7 @@ int rtrs_iu_post_send(struct rtrs_con *con, struct rtrs_iu *iu, size_t size,
 		.send_flags = IB_SEND_SIGNALED,
 	};
 
-	if (head) {
-		struct ib_send_wr *tail = head;
-
-		while (tail->next)
-			tail = tail->next;
-		tail->next = ≀
-	} else {
-		head = ≀
-	}
-
-	return ib_post_send(con->qp, head, NULL);
+	return rtrs_post_send(con->qp, head, &wr);
 }
 EXPORT_SYMBOL_GPL(rtrs_iu_post_send);
 
@@ -168,17 +174,7 @@ int rtrs_iu_post_rdma_write_imm(struct rtrs_con *con, struct rtrs_iu *iu,
 		if (WARN_ON(sge[i].length == 0))
 			return -EINVAL;
 
-	if (head) {
-		struct ib_send_wr *tail = head;
-
-		while (tail->next)
-			tail = tail->next;
-		tail->next = &wr.wr;
-	} else {
-		head = &wr.wr;
-	}
-
-	return ib_post_send(con->qp, head, NULL);
+	return rtrs_post_send(con->qp, head, &wr.wr);
 }
 EXPORT_SYMBOL_GPL(rtrs_iu_post_rdma_write_imm);
 
@@ -195,17 +191,7 @@ int rtrs_post_rdma_write_imm_empty(struct rtrs_con *con, struct ib_cqe *cqe,
 		.ex.imm_data	= cpu_to_be32(imm_data),
 	};
 
-	if (head) {
-		struct ib_send_wr *tail = head;
-
-		while (tail->next)
-			tail = tail->next;
-		tail->next = ≀
-	} else {
-		head = ≀
-	}
-
-	return ib_post_send(con->qp, head, NULL);
+	return rtrs_post_send(con->qp, head, &wr);
 }
 EXPORT_SYMBOL_GPL(rtrs_post_rdma_write_imm_empty);