net/smc: convert static link ID instances to support multiple links

As a preparation for the support of multiple links remove the usage of
a static link id (SMC_SINGLE_LINK) and allow dynamic link ids.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/af_smc.c

@@ -338,28 +338,48 @@ static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
 }
 
 /* register a new rmb, send confirm_rkey msg to register with peer */
-static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
-		       bool conf_rkey)
+static int smcr_link_reg_rmb(struct smc_link *link,
+			     struct smc_buf_desc *rmb_desc, bool conf_rkey)
 {
-	if (!rmb_desc->wr_reg) {
+	if (!rmb_desc->is_reg_mr[link->link_idx]) {
 		/* register memory region for new rmb */
 		if (smc_wr_reg_send(link, rmb_desc->mr_rx[link->link_idx])) {
-			rmb_desc->regerr = 1;
+			rmb_desc->is_reg_err = true;
 			return -EFAULT;
 		}
-		rmb_desc->wr_reg = 1;
+		rmb_desc->is_reg_mr[link->link_idx] = true;
 	}
 	if (!conf_rkey)
 		return 0;
+
 	/* exchange confirm_rkey msg with peer */
-	if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
-		rmb_desc->regerr = 1;
-		return -EFAULT;
+	if (!rmb_desc->is_conf_rkey) {
+		if (smc_llc_do_confirm_rkey(link, rmb_desc)) {
+			rmb_desc->is_reg_err = true;
+			return -EFAULT;
+		}
+		rmb_desc->is_conf_rkey = true;
 	}
 	return 0;
 }
 
-static int smc_clnt_conf_first_link(struct smc_sock *smc)
+/* register the new rmb on all links */
+static int smcr_lgr_reg_rmbs(struct smc_link_group *lgr,
+			     struct smc_buf_desc *rmb_desc)
+{
+	int i, rc;
+
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+		if (lgr->lnk[i].state != SMC_LNK_ACTIVE)
+			continue;
+		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc, true);
+		if (rc)
+			return rc;
+	}
+	return 0;
+}
+
+static int smcr_clnt_conf_first_link(struct smc_sock *smc)
 {
 	struct net *net = sock_net(smc->clcsock->sk);
 	struct smc_link *link = smc->conn.lnk;
@@ -387,7 +407,7 @@ static int smc_clnt_conf_first_link(struct smc_sock *smc)
 
 	smc_wr_remember_qp_attr(link);
 
-	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
+	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc, false))
 		return SMC_CLC_DECL_ERR_REGRMB;
 
 	/* send CONFIRM LINK response over RoCE fabric */
@@ -632,7 +652,7 @@ static int smc_connect_rdma(struct smc_sock *smc,
 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
 						 ini->cln_first_contact);
 	} else {
-		if (smc_reg_rmb(link, smc->conn.rmb_desc, true))
+		if (smcr_lgr_reg_rmbs(smc->conn.lgr, smc->conn.rmb_desc))
 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
 						 ini->cln_first_contact);
 	}
@@ -647,7 +667,7 @@ static int smc_connect_rdma(struct smc_sock *smc,
 
 	if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
 		/* QP confirmation over RoCE fabric */
-		reason_code = smc_clnt_conf_first_link(smc);
+		reason_code = smcr_clnt_conf_first_link(smc);
 		if (reason_code)
 			return smc_connect_abort(smc, reason_code,
 						 ini->cln_first_contact);
@@ -997,14 +1017,14 @@ void smc_close_non_accepted(struct sock *sk)
 	sock_put(sk); /* final sock_put */
 }
 
-static int smc_serv_conf_first_link(struct smc_sock *smc)
+static int smcr_serv_conf_first_link(struct smc_sock *smc)
 {
 	struct net *net = sock_net(smc->clcsock->sk);
 	struct smc_link *link = smc->conn.lnk;
 	int rest;
 	int rc;
 
-	if (smc_reg_rmb(link, smc->conn.rmb_desc, false))
+	if (smcr_link_reg_rmb(link, smc->conn.rmb_desc, false))
 		return SMC_CLC_DECL_ERR_REGRMB;
 
 	/* send CONFIRM LINK request to client over the RoCE fabric */
@@ -1189,10 +1209,10 @@ static int smc_listen_ism_init(struct smc_sock *new_smc,
 /* listen worker: register buffers */
 static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
 {
-	struct smc_link *link = new_smc->conn.lnk;
+	struct smc_connection *conn = &new_smc->conn;
 
 	if (local_contact != SMC_FIRST_CONTACT) {
-		if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
+		if (smcr_lgr_reg_rmbs(conn->lgr, conn->rmb_desc))
 			return SMC_CLC_DECL_ERR_REGRMB;
 	}
 	smc_rmb_sync_sg_for_device(&new_smc->conn);
@@ -1222,7 +1242,7 @@ static int smc_listen_rdma_finish(struct smc_sock *new_smc,
 			goto decline;
 		}
 		/* QP confirmation over RoCE fabric */
-		reason_code = smc_serv_conf_first_link(new_smc);
+		reason_code = smcr_serv_conf_first_link(new_smc);
 		if (reason_code)
 			goto decline;
 	}