[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/net/smc/af_smc.c b/src/kernel/linux/v4.14/net/smc/af_smc.c
new file mode 100644
index 0000000..8c71f09
--- /dev/null
+++ b/src/kernel/linux/v4.14/net/smc/af_smc.c
@@ -0,0 +1,1455 @@
+/*
+ *  Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
+ *  applies to SOCK_STREAM sockets only
+ *  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>
+ *              based on prototype from Frank Blaschka
+ */
+
+#define KMSG_COMPONENT "smc"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/socket.h>
+#include <linux/inetdevice.h>
+#include <linux/workqueue.h>
+#include <linux/in.h>
+#include <linux/sched/signal.h>
+
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <net/smc.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"
+#include "smc_close.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)
+{
+	struct smc_sock *smc = smc_sk(sk);
+
+	smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
+}
+
+static struct smc_hashinfo smc_v4_hashinfo = {
+	.lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
+};
+
+int smc_hash_sk(struct sock *sk)
+{
+	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
+	struct hlist_head *head;
+
+	head = &h->ht;
+
+	write_lock_bh(&h->lock);
+	sk_add_node(sk, head);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+	write_unlock_bh(&h->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(smc_hash_sk);
+
+void smc_unhash_sk(struct sock *sk)
+{
+	struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
+
+	write_lock_bh(&h->lock);
+	if (sk_del_node_init(sk))
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+	write_unlock_bh(&h->lock);
+}
+EXPORT_SYMBOL_GPL(smc_unhash_sk);
+
+struct proto smc_proto = {
+	.name		= "SMC",
+	.owner		= THIS_MODULE,
+	.keepalive	= smc_set_keepalive,
+	.hash		= smc_hash_sk,
+	.unhash		= smc_unhash_sk,
+	.obj_size	= sizeof(struct smc_sock),
+	.h.smc_hash	= &smc_v4_hashinfo,
+	.slab_flags	= SLAB_TYPESAFE_BY_RCU,
+};
+EXPORT_SYMBOL_GPL(smc_proto);
+
+static int smc_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct smc_sock *smc;
+	int rc = 0;
+
+	if (!sk)
+		goto out;
+
+	smc = smc_sk(sk);
+	sock_hold(sk);
+	if (sk->sk_state == SMC_LISTEN)
+		/* smc_close_non_accepted() is called and acquires
+		 * sock lock for child sockets again
+		 */
+		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
+	else
+		lock_sock(sk);
+
+	if (smc->use_fallback) {
+		sk->sk_state = SMC_CLOSED;
+		sk->sk_state_change(sk);
+	} else {
+		rc = smc_close_active(smc);
+		sock_set_flag(sk, SOCK_DEAD);
+		sk->sk_shutdown |= SHUTDOWN_MASK;
+	}
+	if (smc->clcsock) {
+		if (smc->use_fallback && sk->sk_state == SMC_LISTEN) {
+			/* wake up clcsock accept */
+			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
+		}
+		mutex_lock(&smc->clcsock_release_lock);
+		sock_release(smc->clcsock);
+		smc->clcsock = NULL;
+		mutex_unlock(&smc->clcsock_release_lock);
+	}
+
+	/* detach socket */
+	sock_orphan(sk);
+	sock->sk = NULL;
+	if (smc->use_fallback) {
+		schedule_delayed_work(&smc->sock_put_work, TCP_TIMEWAIT_LEN);
+	} else if (sk->sk_state == SMC_CLOSED) {
+		smc_conn_free(&smc->conn);
+		schedule_delayed_work(&smc->sock_put_work,
+				      SMC_CLOSE_SOCK_PUT_DELAY);
+	}
+	release_sock(sk);
+
+	sock_put(sk);
+out:
+	return rc;
+}
+
+static void smc_destruct(struct sock *sk)
+{
+	if (sk->sk_state != SMC_CLOSED)
+		return;
+	if (!sock_flag(sk, SOCK_DEAD))
+		return;
+
+	sk_refcnt_debug_dec(sk);
+}
+
+static struct sock *smc_sock_alloc(struct net *net, struct socket *sock)
+{
+	struct smc_sock *smc;
+	struct sock *sk;
+
+	sk = sk_alloc(net, PF_SMC, GFP_KERNEL, &smc_proto, 0);
+	if (!sk)
+		return NULL;
+
+	sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
+	sk->sk_state = SMC_INIT;
+	sk->sk_destruct = smc_destruct;
+	sk->sk_protocol = SMCPROTO_SMC;
+	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);
+	INIT_DELAYED_WORK(&smc->sock_put_work, smc_close_sock_put_work);
+	sk->sk_prot->hash(sk);
+	sk_refcnt_debug_inc(sk);
+	mutex_init(&smc->clcsock_release_lock);
+
+	return sk;
+}
+
+static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
+		    int addr_len)
+{
+	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
+	struct sock *sk = sock->sk;
+	struct smc_sock *smc;
+	int rc;
+
+	smc = smc_sk(sk);
+
+	/* replicate tests from inet_bind(), to be safe wrt. future changes */
+	rc = -EINVAL;
+	if (addr_len < sizeof(struct sockaddr_in))
+		goto out;
+
+	rc = -EAFNOSUPPORT;
+	/* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
+	if ((addr->sin_family != AF_INET) &&
+	    ((addr->sin_family != AF_UNSPEC) ||
+	     (addr->sin_addr.s_addr != htonl(INADDR_ANY))))
+		goto out;
+
+	lock_sock(sk);
+
+	/* Check if socket is already active */
+	rc = -EINVAL;
+	if (sk->sk_state != SMC_INIT)
+		goto out_rel;
+
+	smc->clcsock->sk->sk_reuse = sk->sk_reuse;
+	rc = kernel_bind(smc->clcsock, uaddr, addr_len);
+
+out_rel:
+	release_sock(sk);
+out:
+	return rc;
+}
+
+static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
+				   unsigned long mask)
+{
+	/* options we don't get control via setsockopt for */
+	nsk->sk_type = osk->sk_type;
+	nsk->sk_sndbuf = osk->sk_sndbuf;
+	nsk->sk_rcvbuf = osk->sk_rcvbuf;
+	nsk->sk_sndtimeo = osk->sk_sndtimeo;
+	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
+	nsk->sk_mark = osk->sk_mark;
+	nsk->sk_priority = osk->sk_priority;
+	nsk->sk_rcvlowat = osk->sk_rcvlowat;
+	nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
+	nsk->sk_err = osk->sk_err;
+
+	nsk->sk_flags &= ~mask;
+	nsk->sk_flags |= osk->sk_flags & mask;
+}
+
+#define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
+			     (1UL << SOCK_KEEPOPEN) | \
+			     (1UL << SOCK_LINGER) | \
+			     (1UL << SOCK_BROADCAST) | \
+			     (1UL << SOCK_TIMESTAMP) | \
+			     (1UL << SOCK_DBG) | \
+			     (1UL << SOCK_RCVTSTAMP) | \
+			     (1UL << SOCK_RCVTSTAMPNS) | \
+			     (1UL << SOCK_LOCALROUTE) | \
+			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
+			     (1UL << SOCK_RXQ_OVFL) | \
+			     (1UL << SOCK_WIFI_STATUS) | \
+			     (1UL << SOCK_NOFCS) | \
+			     (1UL << SOCK_FILTER_LOCKED))
+/* copy only relevant settings and flags of SOL_SOCKET level from smc to
+ * clc socket (since smc is not called for these options from net/core)
+ */
+static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
+{
+	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
+}
+
+#define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
+			     (1UL << SOCK_KEEPOPEN) | \
+			     (1UL << SOCK_LINGER) | \
+			     (1UL << SOCK_DBG))
+/* copy only settings and flags relevant for smc from clc to smc socket */
+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 in_device *in_dev;
+	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 */
+	rcu_read_lock();
+	in_dev = __in_dev_get_rcu(dst->dev);
+	for_ifa(in_dev) {
+		if (!inet_ifa_match(addr.sin_addr.s_addr, ifa))
+			continue;
+		*prefix_len = inet_mask_len(ifa->ifa_mask);
+		*subnet = ifa->ifa_address & ifa->ifa_mask;
+		rc = 0;
+		break;
+	} endfor_ifa(in_dev);
+	rcu_read_unlock();
+
+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);
+
+	rc = smc_wr_reg_send(link,
+			     smc->conn.rmb_desc->mr_rx[SMC_SINGLE_LINK]);
+	if (rc)
+		return SMC_CLC_DECL_INTERR;
+
+	/* 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);
+
+	/* create send buffer and rmb */
+	rc = smc_buf_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;
+	}
+
+	smc_close_init(smc);
+	smc_rx_init(smc);
+
+	if (local_contact == SMC_FIRST_CONTACT) {
+		rc = smc_ib_ready_link(link);
+		if (rc) {
+			reason_code = SMC_CLC_DECL_INTERR;
+			goto decline_rdma_unlock;
+		}
+	} else {
+		struct smc_buf_desc *buf_desc = smc->conn.rmb_desc;
+
+		if (!buf_desc->reused) {
+			/* register memory region for new rmb */
+			rc = smc_wr_reg_send(link,
+					     buf_desc->mr_rx[SMC_SINGLE_LINK]);
+			if (rc) {
+				reason_code = SMC_CLC_DECL_INTERR;
+				goto decline_rdma_unlock;
+			}
+		}
+	}
+	smc_rmb_sync_sg_for_device(&smc->conn);
+
+	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);
+
+out_connected:
+	smc_copy_sock_settings_to_clc(smc);
+	if (smc->sk.sk_state == SMC_INIT)
+		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);
+		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)
+{
+	struct sock *sk = sock->sk;
+	struct smc_sock *smc;
+	int rc = -EINVAL;
+
+	smc = smc_sk(sk);
+
+	/* separate smc parameter checking to be safe */
+	if (alen < sizeof(addr->sa_family))
+		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) {
+	default:
+		goto out;
+	case SMC_ACTIVE:
+		rc = -EISCONN;
+		goto out;
+	case SMC_INIT:
+		rc = 0;
+		break;
+	}
+
+	smc_copy_sock_settings_to_clc(smc);
+	rc = kernel_connect(smc->clcsock, addr, alen, flags);
+	if (rc)
+		goto out;
+
+	/* setup RDMA connection */
+	rc = smc_connect_rdma(smc);
+	if (rc < 0)
+		goto out;
+	else
+		rc = 0; /* success cases including fallback */
+
+out:
+	release_sock(sk);
+out_err:
+	return rc;
+}
+
+static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
+{
+	struct sock *sk = &lsmc->sk;
+	struct socket *new_clcsock;
+	struct sock *new_sk;
+	int rc = -EINVAL;
+
+	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);
+
+	mutex_lock(&lsmc->clcsock_release_lock);
+	if (lsmc->clcsock)
+		rc = kernel_accept(lsmc->clcsock, &new_clcsock, 0);
+	mutex_unlock(&lsmc->clcsock_release_lock);
+	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);
+		sk->sk_prot->unhash(new_sk);
+		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);
+		sk->sk_prot->unhash(new_sk);
+		sock_put(new_sk);
+		*new_smc = NULL;
+		goto out;
+	}
+
+	(*new_smc)->clcsock = new_clcsock;
+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
+ */
+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) {
+			new_sk->sk_prot->unhash(new_sk);
+			sock_put(new_sk);
+			continue;
+		}
+		if (new_sock)
+			sock_graft(new_sk, new_sock);
+		return new_sk;
+	}
+	return NULL;
+}
+
+/* clean up for a created but never accepted sock */
+void smc_close_non_accepted(struct sock *sk)
+{
+	struct smc_sock *smc = smc_sk(sk);
+
+	sock_hold(sk);
+	lock_sock(sk);
+	if (!sk->sk_lingertime)
+		/* wait for peer closing */
+		sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
+	if (smc->use_fallback) {
+		sk->sk_state = SMC_CLOSED;
+	} else {
+		smc_close_active(smc);
+		sock_set_flag(sk, SOCK_DEAD);
+		sk->sk_shutdown |= SHUTDOWN_MASK;
+	}
+	if (smc->clcsock) {
+		struct socket *tcp;
+
+		tcp = smc->clcsock;
+		smc->clcsock = NULL;
+		sock_release(tcp);
+	}
+	if (smc->use_fallback) {
+		schedule_delayed_work(&smc->sock_put_work, TCP_TIMEWAIT_LEN);
+	} else if (sk->sk_state == SMC_CLOSED) {
+		smc_conn_free(&smc->conn);
+		schedule_delayed_work(&smc->sock_put_work,
+				      SMC_CLOSE_SOCK_PUT_DELAY);
+	}
+	release_sock(sk);
+	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];
+
+	rc = smc_wr_reg_send(link,
+			     smc->conn.rmb_desc->mr_rx[SMC_SINGLE_LINK]);
+	if (rc)
+		return SMC_CLC_DECL_INTERR;
+
+	/* 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 < 0) {
+		rc = local_contact;
+		if (rc == -ENOMEM)
+			reason_code = SMC_CLC_DECL_MEM;/* insufficient memory*/
+		goto decline_rdma;
+	}
+	link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
+
+	/* create send buffer and rmb */
+	rc = smc_buf_create(new_smc);
+	if (rc) {
+		reason_code = SMC_CLC_DECL_MEM;
+		goto decline_rdma;
+	}
+
+	smc_close_init(new_smc);
+	smc_rx_init(new_smc);
+
+	if (local_contact != SMC_FIRST_CONTACT) {
+		struct smc_buf_desc *buf_desc = new_smc->conn.rmb_desc;
+
+		if (!buf_desc->reused) {
+			/* register memory region for new rmb */
+			rc = smc_wr_reg_send(link,
+					     buf_desc->mr_rx[SMC_SINGLE_LINK]);
+			if (rc) {
+				reason_code = SMC_CLC_DECL_INTERR;
+				goto decline_rdma;
+			}
+		}
+	}
+	smc_rmb_sync_sg_for_device(&new_smc->conn);
+
+	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);
+
+out_connected:
+	sk_refcnt_debug_inc(newsmcsk);
+	if (newsmcsk->sk_state == SMC_INIT)
+		newsmcsk->sk_state = SMC_ACTIVE;
+enqueue:
+	mutex_unlock(&smc_create_lgr_pending);
+	lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
+	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);
+		if (rc < sizeof(struct smc_clc_msg_decline))
+			goto out_err;
+	}
+	goto out_connected;
+
+out_err:
+	newsmcsk->sk_state = SMC_CLOSED;
+	smc_conn_free(&new_smc->conn);
+	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;
+	struct smc_sock *smc;
+	int rc;
+
+	smc = smc_sk(sk);
+	lock_sock(sk);
+
+	rc = -EINVAL;
+	if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN))
+		goto out;
+
+	rc = 0;
+	if (sk->sk_state == SMC_LISTEN) {
+		sk->sk_max_ack_backlog = backlog;
+		goto out;
+	}
+	/* some socket options are handled in core, so we could not apply
+	 * them to the clc socket -- copy smc socket options to clc socket
+	 */
+	smc_copy_sock_settings_to_clc(smc);
+
+	rc = kernel_listen(smc->clcsock, backlog);
+	if (rc)
+		goto out;
+	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);
+	return rc;
+}
+
+static int smc_accept(struct socket *sock, struct socket *new_sock,
+		      int flags, bool kern)
+{
+	struct sock *sk = sock->sk, *nsk;
+	DECLARE_WAITQUEUE(wait, current);
+	struct smc_sock *lsmc;
+	long timeo;
+	int rc = 0;
+
+	lsmc = smc_sk(sk);
+	lock_sock(sk);
+
+	if (lsmc->sk.sk_state != SMC_LISTEN) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	/* 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);
+
+	if (!rc)
+		rc = sock_error(nsk);
+
+out:
+	release_sock(sk);
+	return rc;
+}
+
+static int smc_getname(struct socket *sock, struct sockaddr *addr,
+		       int *len, int peer)
+{
+	struct smc_sock *smc;
+
+	if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
+	    (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
+		return -ENOTCONN;
+
+	smc = smc_sk(sock->sk);
+
+	return smc->clcsock->ops->getname(smc->clcsock, addr, len, peer);
+}
+
+static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
+{
+	struct sock *sk = sock->sk;
+	struct smc_sock *smc;
+	int rc = -EPIPE;
+
+	smc = smc_sk(sk);
+	lock_sock(sk);
+	if ((sk->sk_state != SMC_ACTIVE) &&
+	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
+	    (sk->sk_state != SMC_INIT))
+		goto out;
+	if (smc->use_fallback)
+		rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
+	else
+		rc = smc_tx_sendmsg(smc, msg, len);
+out:
+	release_sock(sk);
+	return rc;
+}
+
+static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+		       int flags)
+{
+	struct sock *sk = sock->sk;
+	struct smc_sock *smc;
+	int rc = -ENOTCONN;
+
+	smc = smc_sk(sk);
+	lock_sock(sk);
+	if ((sk->sk_state == SMC_INIT) ||
+	    (sk->sk_state == SMC_LISTEN) ||
+	    (sk->sk_state == SMC_CLOSED))
+		goto out;
+
+	if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
+		rc = 0;
+		goto out;
+	}
+
+	if (smc->use_fallback)
+		rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
+	else
+		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) || 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_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 {
+		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) ||
+		    (sk->sk_shutdown & SEND_SHUTDOWN)) {
+			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;
+		if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
+		    (sk->sk_state == SMC_CLOSED))
+			mask |= POLLHUP;
+		if (sk->sk_shutdown & RCV_SHUTDOWN)
+			mask |= POLLIN | POLLRDNORM | POLLRDHUP;
+		if (sk->sk_state == SMC_APPCLOSEWAIT1)
+			mask |= POLLIN;
+
+	}
+
+	return mask;
+}
+
+static int smc_shutdown(struct socket *sock, int how)
+{
+	struct sock *sk = sock->sk;
+	struct smc_sock *smc;
+	int rc = -EINVAL;
+	int rc1 = 0;
+
+	smc = smc_sk(sk);
+
+	if ((how < SHUT_RD) || (how > SHUT_RDWR))
+		return rc;
+
+	lock_sock(sk);
+
+	rc = -ENOTCONN;
+	if ((sk->sk_state != SMC_ACTIVE) &&
+	    (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
+	    (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
+	    (sk->sk_state != SMC_APPCLOSEWAIT1) &&
+	    (sk->sk_state != SMC_APPCLOSEWAIT2) &&
+	    (sk->sk_state != SMC_APPFINCLOSEWAIT))
+		goto out;
+	if (smc->use_fallback) {
+		rc = kernel_sock_shutdown(smc->clcsock, how);
+		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
+		if (sk->sk_shutdown == SHUTDOWN_MASK)
+			sk->sk_state = SMC_CLOSED;
+		goto out;
+	}
+	switch (how) {
+	case SHUT_RDWR:		/* shutdown in both directions */
+		rc = smc_close_active(smc);
+		break;
+	case SHUT_WR:
+		rc = smc_close_shutdown_write(smc);
+		break;
+	case SHUT_RD:
+		rc = 0;
+		/* nothing more to do because peer is not involved */
+		break;
+	}
+	if (smc->clcsock)
+		rc1 = kernel_sock_shutdown(smc->clcsock, how);
+	/* map sock_shutdown_cmd constants to sk_shutdown value range */
+	sk->sk_shutdown |= how + 1;
+
+out:
+	release_sock(sk);
+	return rc ? rc : rc1;
+}
+
+static int smc_setsockopt(struct socket *sock, int level, int optname,
+			  char __user *optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct smc_sock *smc;
+
+	smc = smc_sk(sk);
+
+	/* generic setsockopts reaching us here always apply to the
+	 * CLC socket
+	 */
+	return smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
+					     optval, optlen);
+}
+
+static int smc_getsockopt(struct socket *sock, int level, int optname,
+			  char __user *optval, int __user *optlen)
+{
+	struct smc_sock *smc;
+
+	smc = smc_sk(sock->sk);
+	/* socket options apply to the CLC socket */
+	return smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
+					     optval, optlen);
+}
+
+static int smc_ioctl(struct socket *sock, unsigned int cmd,
+		     unsigned long arg)
+{
+	struct smc_sock *smc;
+
+	smc = smc_sk(sock->sk);
+	if (smc->use_fallback)
+		return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
+	else
+		return sock_no_ioctl(sock, cmd, arg);
+}
+
+static ssize_t smc_sendpage(struct socket *sock, struct page *page,
+			    int offset, size_t size, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct smc_sock *smc;
+	int rc = -EPIPE;
+
+	smc = smc_sk(sk);
+	lock_sock(sk);
+	if (sk->sk_state != SMC_ACTIVE) {
+		release_sock(sk);
+		goto out;
+	}
+	release_sock(sk);
+	if (smc->use_fallback)
+		rc = kernel_sendpage(smc->clcsock, page, offset,
+				     size, flags);
+	else
+		rc = sock_no_sendpage(sock, page, offset, size, flags);
+
+out:
+	return rc;
+}
+
+static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
+			       struct pipe_inode_info *pipe, size_t len,
+				    unsigned int flags)
+{
+	struct sock *sk = sock->sk;
+	struct smc_sock *smc;
+	int rc = -ENOTCONN;
+
+	smc = smc_sk(sk);
+	lock_sock(sk);
+	if ((sk->sk_state != SMC_ACTIVE) && (sk->sk_state != SMC_CLOSED))
+		goto out;
+	if (smc->use_fallback) {
+		rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
+						    pipe, len, flags);
+	} else {
+		rc = -EOPNOTSUPP;
+	}
+out:
+	release_sock(sk);
+	return rc;
+}
+
+/* must look like tcp */
+static const struct proto_ops smc_sock_ops = {
+	.family		= PF_SMC,
+	.owner		= THIS_MODULE,
+	.release	= smc_release,
+	.bind		= smc_bind,
+	.connect	= smc_connect,
+	.socketpair	= sock_no_socketpair,
+	.accept		= smc_accept,
+	.getname	= smc_getname,
+	.poll		= smc_poll,
+	.ioctl		= smc_ioctl,
+	.listen		= smc_listen,
+	.shutdown	= smc_shutdown,
+	.setsockopt	= smc_setsockopt,
+	.getsockopt	= smc_getsockopt,
+	.sendmsg	= smc_sendmsg,
+	.recvmsg	= smc_recvmsg,
+	.mmap		= sock_no_mmap,
+	.sendpage	= smc_sendpage,
+	.splice_read	= smc_splice_read,
+};
+
+static int smc_create(struct net *net, struct socket *sock, int protocol,
+		      int kern)
+{
+	struct smc_sock *smc;
+	struct sock *sk;
+	int rc;
+
+	rc = -ESOCKTNOSUPPORT;
+	if (sock->type != SOCK_STREAM)
+		goto out;
+
+	rc = -EPROTONOSUPPORT;
+	if ((protocol != IPPROTO_IP) && (protocol != IPPROTO_TCP))
+		goto out;
+
+	rc = -ENOBUFS;
+	sock->ops = &smc_sock_ops;
+	sk = smc_sock_alloc(net, sock);
+	if (!sk)
+		goto out;
+
+	/* 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);
+		goto out;
+	}
+	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;
+}
+
+static const struct net_proto_family smc_sock_family_ops = {
+	.family	= PF_SMC,
+	.owner	= THIS_MODULE,
+	.create	= smc_create,
+};
+
+static int __init smc_init(void)
+{
+	int rc;
+
+	rc = smc_pnet_init();
+	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);
+		goto out_pnet;
+	}
+
+	rc = sock_register(&smc_sock_family_ops);
+	if (rc) {
+		pr_err("%s: sock_register fails with %d\n", __func__, rc);
+		goto out_proto;
+	}
+	INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
+
+	rc = smc_ib_register_client();
+	if (rc) {
+		pr_err("%s: ib_register fails with %d\n", __func__, rc);
+		goto out_sock;
+	}
+
+	return 0;
+
+out_sock:
+	sock_unregister(PF_SMC);
+out_proto:
+	proto_unregister(&smc_proto);
+out_pnet:
+	smc_pnet_exit();
+	return rc;
+}
+
+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);
+	smc_pnet_exit();
+}
+
+module_init(smc_init);
+module_exit(smc_exit);
+
+MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("smc socket address family");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(PF_SMC);