smc: receive data from RMBE
[linux-2.6-block.git] / net / smc / af_smc.c
index 8b059b2fc34dcbf5e46dbd65aa86fd54fe3898fa..fc9c51c549e528f8d5f878654e54e4cd04319437 100644 (file)
@@ -6,6 +6,13 @@
  *  offers an alternative communication option for TCP-protocol sockets
  *  applicable with RoCE-cards only
  *
+ *  Initial restrictions:
+ *    - non-blocking connect postponed
+ *    - IPv6 support postponed
+ *    - support for alternate links postponed
+ *    - partial support for non-blocking sockets only
+ *    - support for urgent data postponed
+ *
  *  Copyright IBM Corp. 2016
  *
  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 
 #include <linux/module.h>
 #include <linux/socket.h>
+#include <linux/inetdevice.h>
+#include <linux/workqueue.h>
+#include <linux/in.h>
 #include <net/sock.h>
+#include <net/tcp.h>
 
 #include "smc.h"
+#include "smc_clc.h"
+#include "smc_llc.h"
+#include "smc_cdc.h"
+#include "smc_core.h"
 #include "smc_ib.h"
 #include "smc_pnet.h"
+#include "smc_tx.h"
+#include "smc_rx.h"
+
+static DEFINE_MUTEX(smc_create_lgr_pending);   /* serialize link group
+                                                * creation
+                                                */
+
+struct smc_lgr_list smc_lgr_list = {           /* established link groups */
+       .lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
+       .list = LIST_HEAD_INIT(smc_lgr_list.list),
+};
+
+static void smc_tcp_listen_work(struct work_struct *);
 
 static void smc_set_keepalive(struct sock *sk, int val)
 {
@@ -88,9 +116,11 @@ static struct sock *smc_sock_alloc(struct net *net, struct socket *sock)
        sk->sk_state = SMC_INIT;
        sk->sk_destruct = smc_destruct;
        sk->sk_protocol = SMCPROTO_SMC;
-       sk_refcnt_debug_inc(sk);
-
        smc = smc_sk(sk);
+       INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
+       INIT_LIST_HEAD(&smc->accept_q);
+       spin_lock_init(&smc->accept_q_lock);
+       sk_refcnt_debug_inc(sk);
 
        return sk;
 }
@@ -184,6 +214,233 @@ static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
        smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
 }
 
+/* determine subnet and mask of internal TCP socket */
+int smc_netinfo_by_tcpsk(struct socket *clcsock,
+                        __be32 *subnet, u8 *prefix_len)
+{
+       struct dst_entry *dst = sk_dst_get(clcsock->sk);
+       struct sockaddr_in addr;
+       int rc = -ENOENT;
+       int len;
+
+       if (!dst) {
+               rc = -ENOTCONN;
+               goto out;
+       }
+       if (!dst->dev) {
+               rc = -ENODEV;
+               goto out_rel;
+       }
+
+       /* get address to which the internal TCP socket is bound */
+       kernel_getsockname(clcsock, (struct sockaddr *)&addr, &len);
+       /* analyze IPv4 specific data of net_device belonging to TCP socket */
+       for_ifa(dst->dev->ip_ptr) {
+               if (ifa->ifa_address != addr.sin_addr.s_addr)
+                       continue;
+               *prefix_len = inet_mask_len(ifa->ifa_mask);
+               *subnet = ifa->ifa_address & ifa->ifa_mask;
+               rc = 0;
+               break;
+       } endfor_ifa(dst->dev->ip_ptr);
+
+out_rel:
+       dst_release(dst);
+out:
+       return rc;
+}
+
+static int smc_clnt_conf_first_link(struct smc_sock *smc, union ib_gid *gid)
+{
+       struct smc_link_group *lgr = smc->conn.lgr;
+       struct smc_link *link;
+       int rest;
+       int rc;
+
+       link = &lgr->lnk[SMC_SINGLE_LINK];
+       /* receive CONFIRM LINK request from server over RoCE fabric */
+       rest = wait_for_completion_interruptible_timeout(
+               &link->llc_confirm,
+               SMC_LLC_WAIT_FIRST_TIME);
+       if (rest <= 0) {
+               struct smc_clc_msg_decline dclc;
+
+               rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
+                                     SMC_CLC_DECLINE);
+               return rc;
+       }
+
+       rc = smc_ib_modify_qp_rts(link);
+       if (rc)
+               return SMC_CLC_DECL_INTERR;
+
+       smc_wr_remember_qp_attr(link);
+       /* send CONFIRM LINK response over RoCE fabric */
+       rc = smc_llc_send_confirm_link(link,
+                                      link->smcibdev->mac[link->ibport - 1],
+                                      gid, SMC_LLC_RESP);
+       if (rc < 0)
+               return SMC_CLC_DECL_TCL;
+
+       return rc;
+}
+
+static void smc_conn_save_peer_info(struct smc_sock *smc,
+                                   struct smc_clc_msg_accept_confirm *clc)
+{
+       smc->conn.peer_conn_idx = clc->conn_idx;
+       smc->conn.local_tx_ctrl.token = ntohl(clc->rmbe_alert_token);
+       smc->conn.peer_rmbe_size = smc_uncompress_bufsize(clc->rmbe_size);
+       atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
+}
+
+static void smc_link_save_peer_info(struct smc_link *link,
+                                   struct smc_clc_msg_accept_confirm *clc)
+{
+       link->peer_qpn = ntoh24(clc->qpn);
+       memcpy(link->peer_gid, clc->lcl.gid, SMC_GID_SIZE);
+       memcpy(link->peer_mac, clc->lcl.mac, sizeof(link->peer_mac));
+       link->peer_psn = ntoh24(clc->psn);
+       link->peer_mtu = clc->qp_mtu;
+}
+
+/* setup for RDMA connection of client */
+static int smc_connect_rdma(struct smc_sock *smc)
+{
+       struct sockaddr_in *inaddr = (struct sockaddr_in *)smc->addr;
+       struct smc_clc_msg_accept_confirm aclc;
+       int local_contact = SMC_FIRST_CONTACT;
+       struct smc_ib_device *smcibdev;
+       struct smc_link *link;
+       u8 srv_first_contact;
+       int reason_code = 0;
+       int rc = 0;
+       u8 ibport;
+
+       /* IPSec connections opt out of SMC-R optimizations */
+       if (using_ipsec(smc)) {
+               reason_code = SMC_CLC_DECL_IPSEC;
+               goto decline_rdma;
+       }
+
+       /* PNET table look up: search active ib_device and port
+        * within same PNETID that also contains the ethernet device
+        * used for the internal TCP socket
+        */
+       smc_pnet_find_roce_resource(smc->clcsock->sk, &smcibdev, &ibport);
+       if (!smcibdev) {
+               reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
+               goto decline_rdma;
+       }
+
+       /* do inband token exchange */
+       reason_code = smc_clc_send_proposal(smc, smcibdev, ibport);
+       if (reason_code < 0) {
+               rc = reason_code;
+               goto out_err;
+       }
+       if (reason_code > 0) /* configuration error */
+               goto decline_rdma;
+       /* receive SMC Accept CLC message */
+       reason_code = smc_clc_wait_msg(smc, &aclc, sizeof(aclc),
+                                      SMC_CLC_ACCEPT);
+       if (reason_code < 0) {
+               rc = reason_code;
+               goto out_err;
+       }
+       if (reason_code > 0)
+               goto decline_rdma;
+
+       srv_first_contact = aclc.hdr.flag;
+       mutex_lock(&smc_create_lgr_pending);
+       local_contact = smc_conn_create(smc, inaddr->sin_addr.s_addr, smcibdev,
+                                       ibport, &aclc.lcl, srv_first_contact);
+       if (local_contact < 0) {
+               rc = local_contact;
+               if (rc == -ENOMEM)
+                       reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
+               else if (rc == -ENOLINK)
+                       reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
+               goto decline_rdma_unlock;
+       }
+       link = &smc->conn.lgr->lnk[SMC_SINGLE_LINK];
+
+       smc_conn_save_peer_info(smc, &aclc);
+
+       rc = smc_sndbuf_create(smc);
+       if (rc) {
+               reason_code = SMC_CLC_DECL_MEM;
+               goto decline_rdma_unlock;
+       }
+       rc = smc_rmb_create(smc);
+       if (rc) {
+               reason_code = SMC_CLC_DECL_MEM;
+               goto decline_rdma_unlock;
+       }
+
+       if (local_contact == SMC_FIRST_CONTACT)
+               smc_link_save_peer_info(link, &aclc);
+
+       rc = smc_rmb_rtoken_handling(&smc->conn, &aclc);
+       if (rc) {
+               reason_code = SMC_CLC_DECL_INTERR;
+               goto decline_rdma_unlock;
+       }
+
+       if (local_contact == SMC_FIRST_CONTACT) {
+               rc = smc_ib_ready_link(link);
+               if (rc) {
+                       reason_code = SMC_CLC_DECL_INTERR;
+                       goto decline_rdma_unlock;
+               }
+       }
+
+       rc = smc_clc_send_confirm(smc);
+       if (rc)
+               goto out_err_unlock;
+
+       if (local_contact == SMC_FIRST_CONTACT) {
+               /* QP confirmation over RoCE fabric */
+               reason_code = smc_clnt_conf_first_link(
+                       smc, &smcibdev->gid[ibport - 1]);
+               if (reason_code < 0) {
+                       rc = reason_code;
+                       goto out_err_unlock;
+               }
+               if (reason_code > 0)
+                       goto decline_rdma_unlock;
+       }
+
+       mutex_unlock(&smc_create_lgr_pending);
+       smc_tx_init(smc);
+       smc_rx_init(smc);
+
+out_connected:
+       smc_copy_sock_settings_to_clc(smc);
+       smc->sk.sk_state = SMC_ACTIVE;
+
+       return rc ? rc : local_contact;
+
+decline_rdma_unlock:
+       mutex_unlock(&smc_create_lgr_pending);
+       smc_conn_free(&smc->conn);
+decline_rdma:
+       /* RDMA setup failed, switch back to TCP */
+       smc->use_fallback = true;
+       if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
+               rc = smc_clc_send_decline(smc, reason_code, 0);
+               if (rc < sizeof(struct smc_clc_msg_decline))
+                       goto out_err;
+       }
+       goto out_connected;
+
+out_err_unlock:
+       mutex_unlock(&smc_create_lgr_pending);
+       smc_conn_free(&smc->conn);
+out_err:
+       return rc;
+}
+
 static int smc_connect(struct socket *sock, struct sockaddr *addr,
                       int alen, int flags)
 {
@@ -198,6 +455,7 @@ static int smc_connect(struct socket *sock, struct sockaddr *addr,
                goto out_err;
        if (addr->sa_family != AF_INET)
                goto out_err;
+       smc->addr = addr;       /* needed for nonblocking connect */
 
        lock_sock(sk);
        switch (sk->sk_state) {
@@ -216,12 +474,12 @@ static int smc_connect(struct socket *sock, struct sockaddr *addr,
        if (rc)
                goto out;
 
-       sk->sk_state = SMC_ACTIVE;
-
-       /* always use TCP fallback as transport mechanism for now;
-        * This will change once RDMA transport is implemented
-        */
-       smc->use_fallback = true;
+       /* setup RDMA connection */
+       rc = smc_connect_rdma(smc);
+       if (rc < 0)
+               goto out;
+       else
+               rc = 0; /* success cases including fallback */
 
 out:
        release_sock(sk);
@@ -236,17 +494,32 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
        struct sock *new_sk;
        int rc;
 
+       release_sock(&lsmc->sk);
        new_sk = smc_sock_alloc(sock_net(sk), NULL);
        if (!new_sk) {
                rc = -ENOMEM;
                lsmc->sk.sk_err = ENOMEM;
                *new_smc = NULL;
+               lock_sock(&lsmc->sk);
                goto out;
        }
        *new_smc = smc_sk(new_sk);
 
        rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
-       if (rc) {
+       lock_sock(&lsmc->sk);
+       if  (rc < 0) {
+               lsmc->sk.sk_err = -rc;
+               new_sk->sk_state = SMC_CLOSED;
+               sock_set_flag(new_sk, SOCK_DEAD);
+               sock_put(new_sk);
+               *new_smc = NULL;
+               goto out;
+       }
+       if (lsmc->sk.sk_state == SMC_CLOSED) {
+               if (new_clcsock)
+                       sock_release(new_clcsock);
+               new_sk->sk_state = SMC_CLOSED;
+               sock_set_flag(new_sk, SOCK_DEAD);
                sock_put(new_sk);
                *new_smc = NULL;
                goto out;
@@ -257,6 +530,298 @@ out:
        return rc;
 }
 
+/* add a just created sock to the accept queue of the listen sock as
+ * candidate for a following socket accept call from user space
+ */
+static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
+{
+       struct smc_sock *par = smc_sk(parent);
+
+       sock_hold(sk);
+       spin_lock(&par->accept_q_lock);
+       list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
+       spin_unlock(&par->accept_q_lock);
+       sk_acceptq_added(parent);
+}
+
+/* remove a socket from the accept queue of its parental listening socket */
+static void smc_accept_unlink(struct sock *sk)
+{
+       struct smc_sock *par = smc_sk(sk)->listen_smc;
+
+       spin_lock(&par->accept_q_lock);
+       list_del_init(&smc_sk(sk)->accept_q);
+       spin_unlock(&par->accept_q_lock);
+       sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
+       sock_put(sk);
+}
+
+/* remove a sock from the accept queue to bind it to a new socket created
+ * for a socket accept call from user space
+ */
+static struct sock *smc_accept_dequeue(struct sock *parent,
+                                      struct socket *new_sock)
+{
+       struct smc_sock *isk, *n;
+       struct sock *new_sk;
+
+       list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
+               new_sk = (struct sock *)isk;
+
+               smc_accept_unlink(new_sk);
+               if (new_sk->sk_state == SMC_CLOSED) {
+                       /* tbd in follow-on patch: close this sock */
+                       continue;
+               }
+               if (new_sock)
+                       sock_graft(new_sk, new_sock);
+               return new_sk;
+       }
+       return NULL;
+}
+
+/* clean up for a created but never accepted sock */
+static void smc_close_non_accepted(struct sock *sk)
+{
+       struct smc_sock *smc = smc_sk(sk);
+
+       sock_hold(sk);
+       if (smc->clcsock) {
+               struct socket *tcp;
+
+               tcp = smc->clcsock;
+               smc->clcsock = NULL;
+               sock_release(tcp);
+       }
+       /* more closing stuff to be added with socket closing patch */
+       sock_put(sk);
+}
+
+static int smc_serv_conf_first_link(struct smc_sock *smc)
+{
+       struct smc_link_group *lgr = smc->conn.lgr;
+       struct smc_link *link;
+       int rest;
+       int rc;
+
+       link = &lgr->lnk[SMC_SINGLE_LINK];
+       /* send CONFIRM LINK request to client over the RoCE fabric */
+       rc = smc_llc_send_confirm_link(link,
+                                      link->smcibdev->mac[link->ibport - 1],
+                                      &link->smcibdev->gid[link->ibport - 1],
+                                      SMC_LLC_REQ);
+       if (rc < 0)
+               return SMC_CLC_DECL_TCL;
+
+       /* receive CONFIRM LINK response from client over the RoCE fabric */
+       rest = wait_for_completion_interruptible_timeout(
+               &link->llc_confirm_resp,
+               SMC_LLC_WAIT_FIRST_TIME);
+       if (rest <= 0) {
+               struct smc_clc_msg_decline dclc;
+
+               rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
+                                     SMC_CLC_DECLINE);
+       }
+
+       return rc;
+}
+
+/* setup for RDMA connection of server */
+static void smc_listen_work(struct work_struct *work)
+{
+       struct smc_sock *new_smc = container_of(work, struct smc_sock,
+                                               smc_listen_work);
+       struct socket *newclcsock = new_smc->clcsock;
+       struct smc_sock *lsmc = new_smc->listen_smc;
+       struct smc_clc_msg_accept_confirm cclc;
+       int local_contact = SMC_REUSE_CONTACT;
+       struct sock *newsmcsk = &new_smc->sk;
+       struct smc_clc_msg_proposal pclc;
+       struct smc_ib_device *smcibdev;
+       struct sockaddr_in peeraddr;
+       struct smc_link *link;
+       int reason_code = 0;
+       int rc = 0, len;
+       __be32 subnet;
+       u8 prefix_len;
+       u8 ibport;
+
+       /* do inband token exchange -
+        *wait for and receive SMC Proposal CLC message
+        */
+       reason_code = smc_clc_wait_msg(new_smc, &pclc, sizeof(pclc),
+                                      SMC_CLC_PROPOSAL);
+       if (reason_code < 0)
+               goto out_err;
+       if (reason_code > 0)
+               goto decline_rdma;
+
+       /* IPSec connections opt out of SMC-R optimizations */
+       if (using_ipsec(new_smc)) {
+               reason_code = SMC_CLC_DECL_IPSEC;
+               goto decline_rdma;
+       }
+
+       /* PNET table look up: search active ib_device and port
+        * within same PNETID that also contains the ethernet device
+        * used for the internal TCP socket
+        */
+       smc_pnet_find_roce_resource(newclcsock->sk, &smcibdev, &ibport);
+       if (!smcibdev) {
+               reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
+               goto decline_rdma;
+       }
+
+       /* determine subnet and mask from internal TCP socket */
+       rc = smc_netinfo_by_tcpsk(newclcsock, &subnet, &prefix_len);
+       if (rc) {
+               reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
+               goto decline_rdma;
+       }
+       if ((pclc.outgoing_subnet != subnet) ||
+           (pclc.prefix_len != prefix_len)) {
+               reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
+               goto decline_rdma;
+       }
+
+       /* get address of the peer connected to the internal TCP socket */
+       kernel_getpeername(newclcsock, (struct sockaddr *)&peeraddr, &len);
+
+       /* allocate connection / link group */
+       mutex_lock(&smc_create_lgr_pending);
+       local_contact = smc_conn_create(new_smc, peeraddr.sin_addr.s_addr,
+                                       smcibdev, ibport, &pclc.lcl, 0);
+       if (local_contact == SMC_REUSE_CONTACT)
+               /* lock no longer needed, free it due to following
+                * smc_clc_wait_msg() call
+                */
+               mutex_unlock(&smc_create_lgr_pending);
+       if (local_contact < 0) {
+               rc = local_contact;
+               if (rc == -ENOMEM)
+                       reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
+               else if (rc == -ENOLINK)
+                       reason_code = SMC_CLC_DECL_SYNCERR; /* synchr. error */
+               goto decline_rdma;
+       }
+       link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
+
+       rc = smc_sndbuf_create(new_smc);
+       if (rc) {
+               reason_code = SMC_CLC_DECL_MEM;
+               goto decline_rdma;
+       }
+       rc = smc_rmb_create(new_smc);
+       if (rc) {
+               reason_code = SMC_CLC_DECL_MEM;
+               goto decline_rdma;
+       }
+
+       rc = smc_clc_send_accept(new_smc, local_contact);
+       if (rc)
+               goto out_err;
+
+       /* receive SMC Confirm CLC message */
+       reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
+                                      SMC_CLC_CONFIRM);
+       if (reason_code < 0)
+               goto out_err;
+       if (reason_code > 0)
+               goto decline_rdma;
+       smc_conn_save_peer_info(new_smc, &cclc);
+       if (local_contact == SMC_FIRST_CONTACT)
+               smc_link_save_peer_info(link, &cclc);
+
+       rc = smc_rmb_rtoken_handling(&new_smc->conn, &cclc);
+       if (rc) {
+               reason_code = SMC_CLC_DECL_INTERR;
+               goto decline_rdma;
+       }
+
+       if (local_contact == SMC_FIRST_CONTACT) {
+               rc = smc_ib_ready_link(link);
+               if (rc) {
+                       reason_code = SMC_CLC_DECL_INTERR;
+                       goto decline_rdma;
+               }
+               /* QP confirmation over RoCE fabric */
+               reason_code = smc_serv_conf_first_link(new_smc);
+               if (reason_code < 0) {
+                       /* peer is not aware of a problem */
+                       rc = reason_code;
+                       goto out_err;
+               }
+               if (reason_code > 0)
+                       goto decline_rdma;
+       }
+
+       smc_tx_init(new_smc);
+       smc_rx_init(new_smc);
+
+out_connected:
+       sk_refcnt_debug_inc(newsmcsk);
+       newsmcsk->sk_state = SMC_ACTIVE;
+enqueue:
+       if (local_contact == SMC_FIRST_CONTACT)
+               mutex_unlock(&smc_create_lgr_pending);
+       lock_sock(&lsmc->sk);
+       if (lsmc->sk.sk_state == SMC_LISTEN) {
+               smc_accept_enqueue(&lsmc->sk, newsmcsk);
+       } else { /* no longer listening */
+               smc_close_non_accepted(newsmcsk);
+       }
+       release_sock(&lsmc->sk);
+
+       /* Wake up accept */
+       lsmc->sk.sk_data_ready(&lsmc->sk);
+       sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
+       return;
+
+decline_rdma:
+       /* RDMA setup failed, switch back to TCP */
+       smc_conn_free(&new_smc->conn);
+       new_smc->use_fallback = true;
+       if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
+               rc = smc_clc_send_decline(new_smc, reason_code, 0);
+               if (rc < sizeof(struct smc_clc_msg_decline))
+                       goto out_err;
+       }
+       goto out_connected;
+
+out_err:
+       newsmcsk->sk_state = SMC_CLOSED;
+       goto enqueue; /* queue new sock with sk_err set */
+}
+
+static void smc_tcp_listen_work(struct work_struct *work)
+{
+       struct smc_sock *lsmc = container_of(work, struct smc_sock,
+                                            tcp_listen_work);
+       struct smc_sock *new_smc;
+       int rc = 0;
+
+       lock_sock(&lsmc->sk);
+       while (lsmc->sk.sk_state == SMC_LISTEN) {
+               rc = smc_clcsock_accept(lsmc, &new_smc);
+               if (rc)
+                       goto out;
+               if (!new_smc)
+                       continue;
+
+               new_smc->listen_smc = lsmc;
+               new_smc->use_fallback = false; /* assume rdma capability first*/
+               sock_hold(&lsmc->sk); /* sock_put in smc_listen_work */
+               INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
+               smc_copy_sock_settings_to_smc(new_smc);
+               schedule_work(&new_smc->smc_listen_work);
+       }
+
+out:
+       release_sock(&lsmc->sk);
+       lsmc->sk.sk_data_ready(&lsmc->sk); /* no more listening, wake accept */
+}
+
 static int smc_listen(struct socket *sock, int backlog)
 {
        struct sock *sk = sock->sk;
@@ -286,6 +851,8 @@ static int smc_listen(struct socket *sock, int backlog)
        sk->sk_max_ack_backlog = backlog;
        sk->sk_ack_backlog = 0;
        sk->sk_state = SMC_LISTEN;
+       INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
+       schedule_work(&smc->tcp_listen_work);
 
 out:
        release_sock(sk);
@@ -295,10 +862,11 @@ out:
 static int smc_accept(struct socket *sock, struct socket *new_sock,
                      int flags)
 {
-       struct smc_sock *new_smc;
-       struct sock *sk = sock->sk;
+       struct sock *sk = sock->sk, *nsk;
+       DECLARE_WAITQUEUE(wait, current);
        struct smc_sock *lsmc;
-       int rc;
+       long timeo;
+       int rc = 0;
 
        lsmc = smc_sk(sk);
        lock_sock(sk);
@@ -308,18 +876,30 @@ static int smc_accept(struct socket *sock, struct socket *new_sock,
                goto out;
        }
 
-       rc = smc_clcsock_accept(lsmc, &new_smc);
-       if (rc)
-               goto out;
-       sock_graft(&new_smc->sk, new_sock);
-       new_smc->sk.sk_state = SMC_ACTIVE;
-
-       smc_copy_sock_settings_to_smc(new_smc);
+       /* Wait for an incoming connection */
+       timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
+       add_wait_queue_exclusive(sk_sleep(sk), &wait);
+       while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
+               set_current_state(TASK_INTERRUPTIBLE);
+               if (!timeo) {
+                       rc = -EAGAIN;
+                       break;
+               }
+               release_sock(sk);
+               timeo = schedule_timeout(timeo);
+               /* wakeup by sk_data_ready in smc_listen_work() */
+               sched_annotate_sleep();
+               lock_sock(sk);
+               if (signal_pending(current)) {
+                       rc = sock_intr_errno(timeo);
+                       break;
+               }
+       }
+       set_current_state(TASK_RUNNING);
+       remove_wait_queue(sk_sleep(sk), &wait);
 
-       /* always use TCP fallback as transport mechanism for now;
-        * This will change once RDMA transport is implemented
-        */
-       new_smc->use_fallback = true;
+       if (!rc)
+               rc = sock_error(nsk);
 
 out:
        release_sock(sk);
@@ -352,7 +932,7 @@ static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
        if (smc->use_fallback)
                rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
        else
-               rc = sock_no_sendmsg(sock, msg, len);
+               rc = smc_tx_sendmsg(smc, msg, len);
 out:
        release_sock(sk);
        return rc;
@@ -373,35 +953,75 @@ static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
        if (smc->use_fallback)
                rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
        else
-               rc = sock_no_recvmsg(sock, msg, len, flags);
+               rc = smc_rx_recvmsg(smc, msg, len, flags);
 out:
        release_sock(sk);
        return rc;
 }
 
+static unsigned int smc_accept_poll(struct sock *parent)
+{
+       struct smc_sock *isk;
+       struct sock *sk;
+
+       lock_sock(parent);
+       list_for_each_entry(isk, &smc_sk(parent)->accept_q, accept_q) {
+               sk = (struct sock *)isk;
+
+               if (sk->sk_state == SMC_ACTIVE) {
+                       release_sock(parent);
+                       return POLLIN | POLLRDNORM;
+               }
+       }
+       release_sock(parent);
+
+       return 0;
+}
+
 static unsigned int smc_poll(struct file *file, struct socket *sock,
                             poll_table *wait)
 {
        struct sock *sk = sock->sk;
        unsigned int mask = 0;
        struct smc_sock *smc;
+       int rc;
 
        smc = smc_sk(sock->sk);
-       if ((sk->sk_state == SMC_INIT) || (sk->sk_state == SMC_LISTEN) ||
-           smc->use_fallback) {
+       if ((sk->sk_state == SMC_INIT) || smc->use_fallback) {
+               /* delegate to CLC child sock */
                mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
                /* if non-blocking connect finished ... */
                lock_sock(sk);
                if ((sk->sk_state == SMC_INIT) && (mask & POLLOUT)) {
-                       sk->sk_state = SMC_ACTIVE;
-                       /* always use TCP fallback as transport mechanism;
-                        * This will change once RDMA transport is implemented
-                        */
-                       smc->use_fallback = true;
+                       sk->sk_err = smc->clcsock->sk->sk_err;
+                       if (sk->sk_err) {
+                               mask |= POLLERR;
+                       } else {
+                               rc = smc_connect_rdma(smc);
+                               if (rc < 0)
+                                       mask |= POLLERR;
+                               else
+                                       /* success cases including fallback */
+                                       mask |= POLLOUT | POLLWRNORM;
+                       }
                }
                release_sock(sk);
        } else {
-               mask = sock_no_poll(file, sock, wait);
+               sock_poll_wait(file, sk_sleep(sk), wait);
+               if (sk->sk_state == SMC_LISTEN)
+                       /* woken up by sk_data_ready in smc_listen_work() */
+                       mask |= smc_accept_poll(sk);
+               if (sk->sk_err)
+                       mask |= POLLERR;
+               if (atomic_read(&smc->conn.sndbuf_space)) {
+                       mask |= POLLOUT | POLLWRNORM;
+               } else {
+                       sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
+                       set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+               }
+               if (atomic_read(&smc->conn.bytes_to_rcv))
+                       mask |= POLLIN | POLLRDNORM;
+               /* for now - to be enhanced in follow-on patch */
        }
 
        return mask;
@@ -568,10 +1188,13 @@ static int smc_create(struct net *net, struct socket *sock, int protocol,
 
        /* create internal TCP socket for CLC handshake and fallback */
        smc = smc_sk(sk);
+       smc->use_fallback = false; /* assume rdma capability first */
        rc = sock_create_kern(net, PF_INET, SOCK_STREAM,
                              IPPROTO_TCP, &smc->clcsock);
        if (rc)
                sk_common_release(sk);
+       smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
+       smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
 
 out:
        return rc;
@@ -591,6 +1214,18 @@ static int __init smc_init(void)
        if (rc)
                return rc;
 
+       rc = smc_llc_init();
+       if (rc) {
+               pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
+               goto out_pnet;
+       }
+
+       rc = smc_cdc_init();
+       if (rc) {
+               pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
+               goto out_pnet;
+       }
+
        rc = proto_register(&smc_proto, 1);
        if (rc) {
                pr_err("%s: proto_register fails with %d\n", __func__, rc);
@@ -622,6 +1257,17 @@ out_pnet:
 
 static void __exit smc_exit(void)
 {
+       struct smc_link_group *lgr, *lg;
+       LIST_HEAD(lgr_freeing_list);
+
+       spin_lock_bh(&smc_lgr_list.lock);
+       if (!list_empty(&smc_lgr_list.list))
+               list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
+       spin_unlock_bh(&smc_lgr_list.lock);
+       list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
+               list_del_init(&lgr->list);
+               smc_lgr_free(lgr); /* free link group */
+       }
        smc_ib_unregister_client();
        sock_unregister(PF_SMC);
        proto_unregister(&smc_proto);