RDMA/rtrs: Introduce head/tail wr

Introduce tail wr, we can send as the last wr, we want to send the local
invalidate wr after rdma wr in later patch.

While at it, also fix coding style issue.

Link: https://lore.kernel.org/r/20210621055340.11789-2-jinpu.wang@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

@@ -480,7 +480,7 @@ static int rtrs_post_send_rdma(struct rtrs_clt_con *con,
 
 	return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1,
 					    rbuf->rkey, rbuf->addr + off,
-					    imm, flags, wr);
+					    imm, flags, wr, NULL);
 }
 
 static void process_io_rsp(struct rtrs_clt_sess *sess, u32 msg_id,
@@ -999,9 +999,10 @@ rtrs_clt_get_copy_req(struct rtrs_clt_sess *alive_sess,
 }
 
 static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con,
-				    struct rtrs_clt_io_req *req,
-				    struct rtrs_rbuf *rbuf,
-				    u32 size, u32 imm)
+				   struct rtrs_clt_io_req *req,
+				   struct rtrs_rbuf *rbuf,
+				   u32 size, u32 imm, struct ib_send_wr *wr,
+				   struct ib_send_wr *tail)
 {
 	struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
 	struct ib_sge *sge = req->sge;
@@ -1009,6 +1010,7 @@ static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con,
 	struct scatterlist *sg;
 	size_t num_sge;
 	int i;
+	struct ib_send_wr *ptail = NULL;
 
 	for_each_sg(req->sglist, sg, req->sg_cnt, i) {
 		sge[i].addr   = sg_dma_address(sg);
@@ -1033,7 +1035,7 @@ static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con,
 
 	return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge,
 					    rbuf->rkey, rbuf->addr, imm,
-					    flags, NULL);
+					    flags, wr, ptail);
 }
 
 static int rtrs_clt_write_req(struct rtrs_clt_io_req *req)
@@ -1081,8 +1083,8 @@ static int rtrs_clt_write_req(struct rtrs_clt_io_req *req)
 	rtrs_clt_update_all_stats(req, WRITE);
 
 	ret = rtrs_post_rdma_write_sg(req->con, req, rbuf,
-				       req->usr_len + sizeof(*msg),
-				       imm);
+				      req->usr_len + sizeof(*msg),
+				      imm, NULL, NULL);
 	if (unlikely(ret)) {
 		rtrs_err_rl(s,
 			    "Write request failed: error=%d path=%s [%s:%u]\n",

drivers/infiniband/ulp/rtrs/rtrs-pri.h

@@ -305,7 +305,8 @@ int rtrs_iu_post_rdma_write_imm(struct rtrs_con *con, struct rtrs_iu *iu,
 				struct ib_sge *sge, unsigned int num_sge,
 				u32 rkey, u64 rdma_addr, u32 imm_data,
 				enum ib_send_flags flags,
-				struct ib_send_wr *head);
+				struct ib_send_wr *head,
+				struct ib_send_wr *tail);
 
 int rtrs_post_recv_empty(struct rtrs_con *con, struct ib_cqe *cqe);
 int rtrs_post_rdma_write_imm_empty(struct rtrs_con *con, struct ib_cqe *cqe,

drivers/infiniband/ulp/rtrs/rtrs.c

@@ -105,18 +105,21 @@ 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)
+			  struct ib_send_wr *wr, struct ib_send_wr *tail)
 {
 	if (head) {
-		struct ib_send_wr *tail = head;
+		struct ib_send_wr *next = head;
 
-		while (tail->next)
-			tail = tail->next;
-		tail->next = wr;
+		while (next->next)
+			next = next->next;
+		next->next = wr;
 	} else {
 		head = wr;
 	}
 
+	if (tail)
+		wr->next = tail;
+
 	return ib_post_send(qp, head, NULL);
 }
 
@@ -142,15 +145,16 @@ int rtrs_iu_post_send(struct rtrs_con *con, struct rtrs_iu *iu, size_t size,
 		.send_flags = IB_SEND_SIGNALED,
 	};
 
-	return rtrs_post_send(con->qp, head, &wr);
+	return rtrs_post_send(con->qp, head, &wr, NULL);
 }
 EXPORT_SYMBOL_GPL(rtrs_iu_post_send);
 
 int rtrs_iu_post_rdma_write_imm(struct rtrs_con *con, struct rtrs_iu *iu,
-				 struct ib_sge *sge, unsigned int num_sge,
-				 u32 rkey, u64 rdma_addr, u32 imm_data,
-				 enum ib_send_flags flags,
-				 struct ib_send_wr *head)
+				struct ib_sge *sge, unsigned int num_sge,
+				u32 rkey, u64 rdma_addr, u32 imm_data,
+				enum ib_send_flags flags,
+				struct ib_send_wr *head,
+				struct ib_send_wr *tail)
 {
 	struct ib_rdma_wr wr;
 	int i;
@@ -174,7 +178,7 @@ int rtrs_iu_post_rdma_write_imm(struct rtrs_con *con, struct rtrs_iu *iu,
 		if (WARN_ON(sge[i].length == 0))
 			return -EINVAL;
 
-	return rtrs_post_send(con->qp, head, &wr.wr);
+	return rtrs_post_send(con->qp, head, &wr.wr, tail);
 }
 EXPORT_SYMBOL_GPL(rtrs_iu_post_rdma_write_imm);
 
@@ -191,7 +195,7 @@ int rtrs_post_rdma_write_imm_empty(struct rtrs_con *con, struct ib_cqe *cqe,
 		.wr.ex.imm_data	= cpu_to_be32(imm_data),
 	};
 
-	return rtrs_post_send(con->qp, head, &wr.wr);
+	return rtrs_post_send(con->qp, head, &wr.wr, NULL);
 }
 EXPORT_SYMBOL_GPL(rtrs_post_rdma_write_imm_empty);