Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2633 insertions, 0 deletions

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
new file mode 100644
index 000000000..d520ee62c
--- /dev/null
+++ b/net/smc/smc_core.c
@@ -0,0 +1,2633 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ *  Basic Transport Functions exploiting Infiniband API
+ *
+ *  Copyright IBM Corp. 2016
+ *
+ *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
+ */
+
+#include <linux/socket.h>
+#include <linux/if_vlan.h>
+#include <linux/random.h>
+#include <linux/workqueue.h>
+#include <linux/wait.h>
+#include <linux/reboot.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/smc.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/ib_cache.h>
+
+#include "smc.h"
+#include "smc_clc.h"
+#include "smc_core.h"
+#include "smc_ib.h"
+#include "smc_wr.h"
+#include "smc_llc.h"
+#include "smc_cdc.h"
+#include "smc_close.h"
+#include "smc_ism.h"
+#include "smc_netlink.h"
+#include "smc_stats.h"
+#include "smc_tracepoint.h"
+
+#define SMC_LGR_NUM_INCR		256
+#define SMC_LGR_FREE_DELAY_SERV		(600 * HZ)
+#define SMC_LGR_FREE_DELAY_CLNT		(SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
+
+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),
+	.num = 0,
+};
+
+static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
+static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);
+
+static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
+			 struct smc_buf_desc *buf_desc);
+static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
+
+static void smc_link_down_work(struct work_struct *work);
+
+/* return head of link group list and its lock for a given link group */
+static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr,
+						  spinlock_t **lgr_lock)
+{
+	if (lgr->is_smcd) {
+		*lgr_lock = &lgr->smcd->lgr_lock;
+		return &lgr->smcd->lgr_list;
+	}
+
+	*lgr_lock = &smc_lgr_list.lock;
+	return &smc_lgr_list.list;
+}
+
+static void smc_ibdev_cnt_inc(struct smc_link *lnk)
+{
+	atomic_inc(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
+}
+
+static void smc_ibdev_cnt_dec(struct smc_link *lnk)
+{
+	atomic_dec(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
+}
+
+static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
+{
+	/* client link group creation always follows the server link group
+	 * creation. For client use a somewhat higher removal delay time,
+	 * otherwise there is a risk of out-of-sync link groups.
+	 */
+	if (!lgr->freeing) {
+		mod_delayed_work(system_wq, &lgr->free_work,
+				 (!lgr->is_smcd && lgr->role == SMC_CLNT) ?
+						SMC_LGR_FREE_DELAY_CLNT :
+						SMC_LGR_FREE_DELAY_SERV);
+	}
+}
+
+/* Register connection's alert token in our lookup structure.
+ * To use rbtrees we have to implement our own insert core.
+ * Requires @conns_lock
+ * @smc		connection to register
+ * Returns 0 on success, != otherwise.
+ */
+static void smc_lgr_add_alert_token(struct smc_connection *conn)
+{
+	struct rb_node **link, *parent = NULL;
+	u32 token = conn->alert_token_local;
+
+	link = &conn->lgr->conns_all.rb_node;
+	while (*link) {
+		struct smc_connection *cur = rb_entry(*link,
+					struct smc_connection, alert_node);
+
+		parent = *link;
+		if (cur->alert_token_local > token)
+			link = &parent->rb_left;
+		else
+			link = &parent->rb_right;
+	}
+	/* Put the new node there */
+	rb_link_node(&conn->alert_node, parent, link);
+	rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
+}
+
+/* assign an SMC-R link to the connection */
+static int smcr_lgr_conn_assign_link(struct smc_connection *conn, bool first)
+{
+	enum smc_link_state expected = first ? SMC_LNK_ACTIVATING :
+				       SMC_LNK_ACTIVE;
+	int i, j;
+
+	/* do link balancing */
+	conn->lnk = NULL;	/* reset conn->lnk first */
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+		struct smc_link *lnk = &conn->lgr->lnk[i];
+
+		if (lnk->state != expected || lnk->link_is_asym)
+			continue;
+		if (conn->lgr->role == SMC_CLNT) {
+			conn->lnk = lnk; /* temporary, SMC server assigns link*/
+			break;
+		}
+		if (conn->lgr->conns_num % 2) {
+			for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
+				struct smc_link *lnk2;
+
+				lnk2 = &conn->lgr->lnk[j];
+				if (lnk2->state == expected &&
+				    !lnk2->link_is_asym) {
+					conn->lnk = lnk2;
+					break;
+				}
+			}
+		}
+		if (!conn->lnk)
+			conn->lnk = lnk;
+		break;
+	}
+	if (!conn->lnk)
+		return SMC_CLC_DECL_NOACTLINK;
+	atomic_inc(&conn->lnk->conn_cnt);
+	return 0;
+}
+
+/* Register connection in link group by assigning an alert token
+ * registered in a search tree.
+ * Requires @conns_lock
+ * Note that '0' is a reserved value and not assigned.
+ */
+static int smc_lgr_register_conn(struct smc_connection *conn, bool first)
+{
+	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
+	static atomic_t nexttoken = ATOMIC_INIT(0);
+	int rc;
+
+	if (!conn->lgr->is_smcd) {
+		rc = smcr_lgr_conn_assign_link(conn, first);
+		if (rc) {
+			conn->lgr = NULL;
+			return rc;
+		}
+	}
+	/* find a new alert_token_local value not yet used by some connection
+	 * in this link group
+	 */
+	sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
+	while (!conn->alert_token_local) {
+		conn->alert_token_local = atomic_inc_return(&nexttoken);
+		if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
+			conn->alert_token_local = 0;
+	}
+	smc_lgr_add_alert_token(conn);
+	conn->lgr->conns_num++;
+	return 0;
+}
+
+/* Unregister connection and reset the alert token of the given connection<
+ */
+static void __smc_lgr_unregister_conn(struct smc_connection *conn)
+{
+	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
+	struct smc_link_group *lgr = conn->lgr;
+
+	rb_erase(&conn->alert_node, &lgr->conns_all);
+	if (conn->lnk)
+		atomic_dec(&conn->lnk->conn_cnt);
+	lgr->conns_num--;
+	conn->alert_token_local = 0;
+	sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
+}
+
+/* Unregister connection from lgr
+ */
+static void smc_lgr_unregister_conn(struct smc_connection *conn)
+{
+	struct smc_link_group *lgr = conn->lgr;
+
+	if (!smc_conn_lgr_valid(conn))
+		return;
+	write_lock_bh(&lgr->conns_lock);
+	if (conn->alert_token_local) {
+		__smc_lgr_unregister_conn(conn);
+	}
+	write_unlock_bh(&lgr->conns_lock);
+}
+
+int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
+	char hostname[SMC_MAX_HOSTNAME_LEN + 1];
+	char smc_seid[SMC_MAX_EID_LEN + 1];
+	struct nlattr *attrs;
+	u8 *seid = NULL;
+	u8 *host = NULL;
+	void *nlh;
+
+	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &smc_gen_nl_family, NLM_F_MULTI,
+			  SMC_NETLINK_GET_SYS_INFO);
+	if (!nlh)
+		goto errmsg;
+	if (cb_ctx->pos[0])
+		goto errout;
+	attrs = nla_nest_start(skb, SMC_GEN_SYS_INFO);
+	if (!attrs)
+		goto errout;
+	if (nla_put_u8(skb, SMC_NLA_SYS_VER, SMC_V2))
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_SYS_REL, SMC_RELEASE))
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_SYS_IS_ISM_V2, smc_ism_is_v2_capable()))
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_SYS_IS_SMCR_V2, true))
+		goto errattr;
+	smc_clc_get_hostname(&host);
+	if (host) {
+		memcpy(hostname, host, SMC_MAX_HOSTNAME_LEN);
+		hostname[SMC_MAX_HOSTNAME_LEN] = 0;
+		if (nla_put_string(skb, SMC_NLA_SYS_LOCAL_HOST, hostname))
+			goto errattr;
+	}
+	if (smc_ism_is_v2_capable()) {
+		smc_ism_get_system_eid(&seid);
+		memcpy(smc_seid, seid, SMC_MAX_EID_LEN);
+		smc_seid[SMC_MAX_EID_LEN] = 0;
+		if (nla_put_string(skb, SMC_NLA_SYS_SEID, smc_seid))
+			goto errattr;
+	}
+	nla_nest_end(skb, attrs);
+	genlmsg_end(skb, nlh);
+	cb_ctx->pos[0] = 1;
+	return skb->len;
+
+errattr:
+	nla_nest_cancel(skb, attrs);
+errout:
+	genlmsg_cancel(skb, nlh);
+errmsg:
+	return skb->len;
+}
+
+/* Fill SMC_NLA_LGR_D_V2_COMMON/SMC_NLA_LGR_R_V2_COMMON nested attributes */
+static int smc_nl_fill_lgr_v2_common(struct smc_link_group *lgr,
+				     struct sk_buff *skb,
+				     struct netlink_callback *cb,
+				     struct nlattr *v2_attrs)
+{
+	char smc_host[SMC_MAX_HOSTNAME_LEN + 1];
+	char smc_eid[SMC_MAX_EID_LEN + 1];
+
+	if (nla_put_u8(skb, SMC_NLA_LGR_V2_VER, lgr->smc_version))
+		goto errv2attr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_V2_REL, lgr->peer_smc_release))
+		goto errv2attr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os))
+		goto errv2attr;
+	memcpy(smc_host, lgr->peer_hostname, SMC_MAX_HOSTNAME_LEN);
+	smc_host[SMC_MAX_HOSTNAME_LEN] = 0;
+	if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host))
+		goto errv2attr;
+	memcpy(smc_eid, lgr->negotiated_eid, SMC_MAX_EID_LEN);
+	smc_eid[SMC_MAX_EID_LEN] = 0;
+	if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid))
+		goto errv2attr;
+
+	nla_nest_end(skb, v2_attrs);
+	return 0;
+
+errv2attr:
+	nla_nest_cancel(skb, v2_attrs);
+	return -EMSGSIZE;
+}
+
+static int smc_nl_fill_smcr_lgr_v2(struct smc_link_group *lgr,
+				   struct sk_buff *skb,
+				   struct netlink_callback *cb)
+{
+	struct nlattr *v2_attrs;
+
+	v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2);
+	if (!v2_attrs)
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_DIRECT, !lgr->uses_gateway))
+		goto errv2attr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_CONNS, lgr->max_conns))
+		goto errv2attr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_LINKS, lgr->max_links))
+		goto errv2attr;
+
+	nla_nest_end(skb, v2_attrs);
+	return 0;
+
+errv2attr:
+	nla_nest_cancel(skb, v2_attrs);
+errattr:
+	return -EMSGSIZE;
+}
+
+static int smc_nl_fill_lgr(struct smc_link_group *lgr,
+			   struct sk_buff *skb,
+			   struct netlink_callback *cb)
+{
+	char smc_target[SMC_MAX_PNETID_LEN + 1];
+	struct nlattr *attrs, *v2_attrs;
+
+	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCR);
+	if (!attrs)
+		goto errout;
+
+	if (nla_put_u32(skb, SMC_NLA_LGR_R_ID, *((u32 *)&lgr->id)))
+		goto errattr;
+	if (nla_put_u32(skb, SMC_NLA_LGR_R_CONNS_NUM, lgr->conns_num))
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_ROLE, lgr->role))
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_TYPE, lgr->type))
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_BUF_TYPE, lgr->buf_type))
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id))
+		goto errattr;
+	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_R_NET_COOKIE,
+			      lgr->net->net_cookie, SMC_NLA_LGR_R_PAD))
+		goto errattr;
+	memcpy(smc_target, lgr->pnet_id, SMC_MAX_PNETID_LEN);
+	smc_target[SMC_MAX_PNETID_LEN] = 0;
+	if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target))
+		goto errattr;
+	if (lgr->smc_version > SMC_V1) {
+		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2_COMMON);
+		if (!v2_attrs)
+			goto errattr;
+		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
+			goto errattr;
+		if (smc_nl_fill_smcr_lgr_v2(lgr, skb, cb))
+			goto errattr;
+	}
+
+	nla_nest_end(skb, attrs);
+	return 0;
+errattr:
+	nla_nest_cancel(skb, attrs);
+errout:
+	return -EMSGSIZE;
+}
+
+static int smc_nl_fill_lgr_link(struct smc_link_group *lgr,
+				struct smc_link *link,
+				struct sk_buff *skb,
+				struct netlink_callback *cb)
+{
+	char smc_ibname[IB_DEVICE_NAME_MAX];
+	u8 smc_gid_target[41];
+	struct nlattr *attrs;
+	u32 link_uid = 0;
+	void *nlh;
+
+	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &smc_gen_nl_family, NLM_F_MULTI,
+			  SMC_NETLINK_GET_LINK_SMCR);
+	if (!nlh)
+		goto errmsg;
+
+	attrs = nla_nest_start(skb, SMC_GEN_LINK_SMCR);
+	if (!attrs)
+		goto errout;
+
+	if (nla_put_u8(skb, SMC_NLA_LINK_ID, link->link_id))
+		goto errattr;
+	if (nla_put_u32(skb, SMC_NLA_LINK_STATE, link->state))
+		goto errattr;
+	if (nla_put_u32(skb, SMC_NLA_LINK_CONN_CNT,
+			atomic_read(&link->conn_cnt)))
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_LINK_IB_PORT, link->ibport))
+		goto errattr;
+	if (nla_put_u32(skb, SMC_NLA_LINK_NET_DEV, link->ndev_ifidx))
+		goto errattr;
+	snprintf(smc_ibname, sizeof(smc_ibname), "%s", link->ibname);
+	if (nla_put_string(skb, SMC_NLA_LINK_IB_DEV, smc_ibname))
+		goto errattr;
+	memcpy(&link_uid, link->link_uid, sizeof(link_uid));
+	if (nla_put_u32(skb, SMC_NLA_LINK_UID, link_uid))
+		goto errattr;
+	memcpy(&link_uid, link->peer_link_uid, sizeof(link_uid));
+	if (nla_put_u32(skb, SMC_NLA_LINK_PEER_UID, link_uid))
+		goto errattr;
+	memset(smc_gid_target, 0, sizeof(smc_gid_target));
+	smc_gid_be16_convert(smc_gid_target, link->gid);
+	if (nla_put_string(skb, SMC_NLA_LINK_GID, smc_gid_target))
+		goto errattr;
+	memset(smc_gid_target, 0, sizeof(smc_gid_target));
+	smc_gid_be16_convert(smc_gid_target, link->peer_gid);
+	if (nla_put_string(skb, SMC_NLA_LINK_PEER_GID, smc_gid_target))
+		goto errattr;
+
+	nla_nest_end(skb, attrs);
+	genlmsg_end(skb, nlh);
+	return 0;
+errattr:
+	nla_nest_cancel(skb, attrs);
+errout:
+	genlmsg_cancel(skb, nlh);
+errmsg:
+	return -EMSGSIZE;
+}
+
+static int smc_nl_handle_lgr(struct smc_link_group *lgr,
+			     struct sk_buff *skb,
+			     struct netlink_callback *cb,
+			     bool list_links)
+{
+	void *nlh;
+	int i;
+
+	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &smc_gen_nl_family, NLM_F_MULTI,
+			  SMC_NETLINK_GET_LGR_SMCR);
+	if (!nlh)
+		goto errmsg;
+	if (smc_nl_fill_lgr(lgr, skb, cb))
+		goto errout;
+
+	genlmsg_end(skb, nlh);
+	if (!list_links)
+		goto out;
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+		if (!smc_link_usable(&lgr->lnk[i]))
+			continue;
+		if (smc_nl_fill_lgr_link(lgr, &lgr->lnk[i], skb, cb))
+			goto errout;
+	}
+out:
+	return 0;
+
+errout:
+	genlmsg_cancel(skb, nlh);
+errmsg:
+	return -EMSGSIZE;
+}
+
+static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
+				 struct sk_buff *skb,
+				 struct netlink_callback *cb,
+				 bool list_links)
+{
+	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
+	struct smc_link_group *lgr;
+	int snum = cb_ctx->pos[0];
+	int num = 0;
+
+	spin_lock_bh(&smc_lgr->lock);
+	list_for_each_entry(lgr, &smc_lgr->list, list) {
+		if (num < snum)
+			goto next;
+		if (smc_nl_handle_lgr(lgr, skb, cb, list_links))
+			goto errout;
+next:
+		num++;
+	}
+errout:
+	spin_unlock_bh(&smc_lgr->lock);
+	cb_ctx->pos[0] = num;
+}
+
+static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr,
+				struct sk_buff *skb,
+				struct netlink_callback *cb)
+{
+	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
+	struct smcd_dev *smcd = lgr->smcd;
+	struct nlattr *attrs;
+	void *nlh;
+
+	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &smc_gen_nl_family, NLM_F_MULTI,
+			  SMC_NETLINK_GET_LGR_SMCD);
+	if (!nlh)
+		goto errmsg;
+
+	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCD);
+	if (!attrs)
+		goto errout;
+
+	if (nla_put_u32(skb, SMC_NLA_LGR_D_ID, *((u32 *)&lgr->id)))
+		goto errattr;
+	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_GID,
+			      smcd->ops->get_local_gid(smcd),
+				  SMC_NLA_LGR_D_PAD))
+		goto errattr;
+	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_GID, lgr->peer_gid,
+			      SMC_NLA_LGR_D_PAD))
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_D_VLAN_ID, lgr->vlan_id))
+		goto errattr;
+	if (nla_put_u32(skb, SMC_NLA_LGR_D_CONNS_NUM, lgr->conns_num))
+		goto errattr;
+	if (nla_put_u32(skb, SMC_NLA_LGR_D_CHID, smc_ism_get_chid(lgr->smcd)))
+		goto errattr;
+	memcpy(smc_pnet, lgr->smcd->pnetid, SMC_MAX_PNETID_LEN);
+	smc_pnet[SMC_MAX_PNETID_LEN] = 0;
+	if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet))
+		goto errattr;
+	if (lgr->smc_version > SMC_V1) {
+		struct nlattr *v2_attrs;
+
+		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_D_V2_COMMON);
+		if (!v2_attrs)
+			goto errattr;
+		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
+			goto errattr;
+	}
+	nla_nest_end(skb, attrs);
+	genlmsg_end(skb, nlh);
+	return 0;
+
+errattr:
+	nla_nest_cancel(skb, attrs);
+errout:
+	genlmsg_cancel(skb, nlh);
+errmsg:
+	return -EMSGSIZE;
+}
+
+static int smc_nl_handle_smcd_lgr(struct smcd_dev *dev,
+				  struct sk_buff *skb,
+				  struct netlink_callback *cb)
+{
+	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
+	struct smc_link_group *lgr;
+	int snum = cb_ctx->pos[1];
+	int rc = 0, num = 0;
+
+	spin_lock_bh(&dev->lgr_lock);
+	list_for_each_entry(lgr, &dev->lgr_list, list) {
+		if (!lgr->is_smcd)
+			continue;
+		if (num < snum)
+			goto next;
+		rc = smc_nl_fill_smcd_lgr(lgr, skb, cb);
+		if (rc)
+			goto errout;
+next:
+		num++;
+	}
+errout:
+	spin_unlock_bh(&dev->lgr_lock);
+	cb_ctx->pos[1] = num;
+	return rc;
+}
+
+static int smc_nl_fill_smcd_dev(struct smcd_dev_list *dev_list,
+				struct sk_buff *skb,
+				struct netlink_callback *cb)
+{
+	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
+	struct smcd_dev *smcd_dev;
+	int snum = cb_ctx->pos[0];
+	int rc = 0, num = 0;
+
+	mutex_lock(&dev_list->mutex);
+	list_for_each_entry(smcd_dev, &dev_list->list, list) {
+		if (list_empty(&smcd_dev->lgr_list))
+			continue;
+		if (num < snum)
+			goto next;
+		rc = smc_nl_handle_smcd_lgr(smcd_dev, skb, cb);
+		if (rc)
+			goto errout;
+next:
+		num++;
+	}
+errout:
+	mutex_unlock(&dev_list->mutex);
+	cb_ctx->pos[0] = num;
+	return rc;
+}
+
+int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	bool list_links = false;
+
+	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
+	return skb->len;
+}
+
+int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	bool list_links = true;
+
+	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
+	return skb->len;
+}
+
+int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	smc_nl_fill_smcd_dev(&smcd_dev_list, skb, cb);
+	return skb->len;
+}
+
+void smc_lgr_cleanup_early(struct smc_link_group *lgr)
+{
+	spinlock_t *lgr_lock;
+
+	if (!lgr)
+		return;
+
+	smc_lgr_list_head(lgr, &lgr_lock);
+	spin_lock_bh(lgr_lock);
+	/* do not use this link group for new connections */
+	if (!list_empty(&lgr->list))
+		list_del_init(&lgr->list);
+	spin_unlock_bh(lgr_lock);
+	__smc_lgr_terminate(lgr, true);
+}
+
+static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
+{
+	int i;
+
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+		struct smc_link *lnk = &lgr->lnk[i];
+
+		if (smc_link_sendable(lnk))
+			lnk->state = SMC_LNK_INACTIVE;
+	}
+	wake_up_all(&lgr->llc_msg_waiter);
+	wake_up_all(&lgr->llc_flow_waiter);
+}
+
+static void smc_lgr_free(struct smc_link_group *lgr);
+
+static void smc_lgr_free_work(struct work_struct *work)
+{
+	struct smc_link_group *lgr = container_of(to_delayed_work(work),
+						  struct smc_link_group,
+						  free_work);
+	spinlock_t *lgr_lock;
+	bool conns;
+
+	smc_lgr_list_head(lgr, &lgr_lock);
+	spin_lock_bh(lgr_lock);
+	if (lgr->freeing) {
+		spin_unlock_bh(lgr_lock);
+		return;
+	}
+	read_lock_bh(&lgr->conns_lock);
+	conns = RB_EMPTY_ROOT(&lgr->conns_all);
+	read_unlock_bh(&lgr->conns_lock);
+	if (!conns) { /* number of lgr connections is no longer zero */
+		spin_unlock_bh(lgr_lock);
+		return;
+	}
+	list_del_init(&lgr->list); /* remove from smc_lgr_list */
+	lgr->freeing = 1; /* this instance does the freeing, no new schedule */
+	spin_unlock_bh(lgr_lock);
+	cancel_delayed_work(&lgr->free_work);
+
+	if (!lgr->is_smcd && !lgr->terminating)
+		smc_llc_send_link_delete_all(lgr, true,
+					     SMC_LLC_DEL_PROG_INIT_TERM);
+	if (lgr->is_smcd && !lgr->terminating)
+		smc_ism_signal_shutdown(lgr);
+	if (!lgr->is_smcd)
+		smcr_lgr_link_deactivate_all(lgr);
+	smc_lgr_free(lgr);
+}
+
+static void smc_lgr_terminate_work(struct work_struct *work)
+{
+	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
+						  terminate_work);
+
+	__smc_lgr_terminate(lgr, true);
+}
+
+/* return next unique link id for the lgr */
+static u8 smcr_next_link_id(struct smc_link_group *lgr)
+{
+	u8 link_id;
+	int i;
+
+	while (1) {
+again:
+		link_id = ++lgr->next_link_id;
+		if (!link_id)	/* skip zero as link_id */
+			link_id = ++lgr->next_link_id;
+		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+			if (smc_link_usable(&lgr->lnk[i]) &&
+			    lgr->lnk[i].link_id == link_id)
+				goto again;
+		}
+		break;
+	}
+	return link_id;
+}
+
+static void smcr_copy_dev_info_to_link(struct smc_link *link)
+{
+	struct smc_ib_device *smcibdev = link->smcibdev;
+
+	snprintf(link->ibname, sizeof(link->ibname), "%s",
+		 smcibdev->ibdev->name);
+	link->ndev_ifidx = smcibdev->ndev_ifidx[link->ibport - 1];
+}
+
+int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
+		   u8 link_idx, struct smc_init_info *ini)
+{
+	struct smc_ib_device *smcibdev;
+	u8 rndvec[3];
+	int rc;
+
+	if (lgr->smc_version == SMC_V2) {
+		lnk->smcibdev = ini->smcrv2.ib_dev_v2;
+		lnk->ibport = ini->smcrv2.ib_port_v2;
+	} else {
+		lnk->smcibdev = ini->ib_dev;
+		lnk->ibport = ini->ib_port;
+	}
+	get_device(&lnk->smcibdev->ibdev->dev);
+	atomic_inc(&lnk->smcibdev->lnk_cnt);
+	refcount_set(&lnk->refcnt, 1); /* link refcnt is set to 1 */
+	lnk->clearing = 0;
+	lnk->path_mtu = lnk->smcibdev->pattr[lnk->ibport - 1].active_mtu;
+	lnk->link_id = smcr_next_link_id(lgr);
+	lnk->lgr = lgr;
+	smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */
+	lnk->link_idx = link_idx;
+	lnk->wr_rx_id_compl = 0;
+	smc_ibdev_cnt_inc(lnk);
+	smcr_copy_dev_info_to_link(lnk);
+	atomic_set(&lnk->conn_cnt, 0);
+	smc_llc_link_set_uid(lnk);
+	INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
+	if (!lnk->smcibdev->initialized) {
+		rc = (int)smc_ib_setup_per_ibdev(lnk->smcibdev);
+		if (rc)
+			goto out;
+	}
+	get_random_bytes(rndvec, sizeof(rndvec));
+	lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
+		(rndvec[2] << 16);
+	rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
+				  ini->vlan_id, lnk->gid, &lnk->sgid_index,
+				  lgr->smc_version == SMC_V2 ?
+						  &ini->smcrv2 : NULL);
+	if (rc)
+		goto out;
+	rc = smc_llc_link_init(lnk);
+	if (rc)
+		goto out;
+	rc = smc_wr_alloc_link_mem(lnk);
+	if (rc)
+		goto clear_llc_lnk;
+	rc = smc_ib_create_protection_domain(lnk);
+	if (rc)
+		goto free_link_mem;
+	rc = smc_ib_create_queue_pair(lnk);
+	if (rc)
+		goto dealloc_pd;
+	rc = smc_wr_create_link(lnk);
+	if (rc)
+		goto destroy_qp;
+	lnk->state = SMC_LNK_ACTIVATING;
+	return 0;
+
+destroy_qp:
+	smc_ib_destroy_queue_pair(lnk);
+dealloc_pd:
+	smc_ib_dealloc_protection_domain(lnk);
+free_link_mem:
+	smc_wr_free_link_mem(lnk);
+clear_llc_lnk:
+	smc_llc_link_clear(lnk, false);
+out:
+	smc_ibdev_cnt_dec(lnk);
+	put_device(&lnk->smcibdev->ibdev->dev);
+	smcibdev = lnk->smcibdev;
+	memset(lnk, 0, sizeof(struct smc_link));
+	lnk->state = SMC_LNK_UNUSED;
+	if (!atomic_dec_return(&smcibdev->lnk_cnt))
+		wake_up(&smcibdev->lnks_deleted);
+	smc_lgr_put(lgr); /* lgr_hold above */
+	return rc;
+}
+
+/* create a new SMC link group */
+static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
+{
+	struct smc_link_group *lgr;
+	struct list_head *lgr_list;
+	struct smcd_dev *smcd;
+	struct smc_link *lnk;
+	spinlock_t *lgr_lock;
+	u8 link_idx;
+	int rc = 0;
+	int i;
+
+	if (ini->is_smcd && ini->vlan_id) {
+		if (smc_ism_get_vlan(ini->ism_dev[ini->ism_selected],
+				     ini->vlan_id)) {
+			rc = SMC_CLC_DECL_ISMVLANERR;
+			goto out;
+		}
+	}
+
+	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
+	if (!lgr) {
+		rc = SMC_CLC_DECL_MEM;
+		goto ism_put_vlan;
+	}
+	lgr->tx_wq = alloc_workqueue("smc_tx_wq-%*phN", 0, 0,
+				     SMC_LGR_ID_SIZE, &lgr->id);
+	if (!lgr->tx_wq) {
+		rc = -ENOMEM;
+		goto free_lgr;
+	}
+	lgr->is_smcd = ini->is_smcd;
+	lgr->sync_err = 0;
+	lgr->terminating = 0;
+	lgr->freeing = 0;
+	lgr->vlan_id = ini->vlan_id;
+	refcount_set(&lgr->refcnt, 1); /* set lgr refcnt to 1 */
+	init_rwsem(&lgr->sndbufs_lock);
+	init_rwsem(&lgr->rmbs_lock);
+	rwlock_init(&lgr->conns_lock);
+	for (i = 0; i < SMC_RMBE_SIZES; i++) {
+		INIT_LIST_HEAD(&lgr->sndbufs[i]);
+		INIT_LIST_HEAD(&lgr->rmbs[i]);
+	}
+	lgr->next_link_id = 0;
+	smc_lgr_list.num += SMC_LGR_NUM_INCR;
+	memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
+	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
+	INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
+	lgr->conns_all = RB_ROOT;
+	if (ini->is_smcd) {
+		/* SMC-D specific settings */
+		smcd = ini->ism_dev[ini->ism_selected];
+		get_device(smcd->ops->get_dev(smcd));
+		lgr->peer_gid = ini->ism_peer_gid[ini->ism_selected];
+		lgr->smcd = ini->ism_dev[ini->ism_selected];
+		lgr_list = &ini->ism_dev[ini->ism_selected]->lgr_list;
+		lgr_lock = &lgr->smcd->lgr_lock;
+		lgr->smc_version = ini->smcd_version;
+		lgr->peer_shutdown = 0;
+		atomic_inc(&ini->ism_dev[ini->ism_selected]->lgr_cnt);
+	} else {
+		/* SMC-R specific settings */
+		struct smc_ib_device *ibdev;
+		int ibport;
+
+		lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
+		lgr->smc_version = ini->smcr_version;
+		memcpy(lgr->peer_systemid, ini->peer_systemid,
+		       SMC_SYSTEMID_LEN);
+		if (lgr->smc_version == SMC_V2) {
+			ibdev = ini->smcrv2.ib_dev_v2;
+			ibport = ini->smcrv2.ib_port_v2;
+			lgr->saddr = ini->smcrv2.saddr;
+			lgr->uses_gateway = ini->smcrv2.uses_gateway;
+			memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
+			       ETH_ALEN);
+			lgr->max_conns = ini->max_conns;
+			lgr->max_links = ini->max_links;
+		} else {
+			ibdev = ini->ib_dev;
+			ibport = ini->ib_port;
+			lgr->max_conns = SMC_CONN_PER_LGR_MAX;
+			lgr->max_links = SMC_LINKS_ADD_LNK_MAX;
+		}
+		memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
+		       SMC_MAX_PNETID_LEN);
+		rc = smc_wr_alloc_lgr_mem(lgr);
+		if (rc)
+			goto free_wq;
+		smc_llc_lgr_init(lgr, smc);
+
+		link_idx = SMC_SINGLE_LINK;
+		lnk = &lgr->lnk[link_idx];
+		rc = smcr_link_init(lgr, lnk, link_idx, ini);
+		if (rc) {
+			smc_wr_free_lgr_mem(lgr);
+			goto free_wq;
+		}
+		lgr->net = smc_ib_net(lnk->smcibdev);
+		lgr_list = &smc_lgr_list.list;
+		lgr_lock = &smc_lgr_list.lock;
+		lgr->buf_type = lgr->net->smc.sysctl_smcr_buf_type;
+		atomic_inc(&lgr_cnt);
+	}
+	smc->conn.lgr = lgr;
+	spin_lock_bh(lgr_lock);
+	list_add_tail(&lgr->list, lgr_list);
+	spin_unlock_bh(lgr_lock);
+	return 0;
+
+free_wq:
+	destroy_workqueue(lgr->tx_wq);
+free_lgr:
+	kfree(lgr);
+ism_put_vlan:
+	if (ini->is_smcd && ini->vlan_id)
+		smc_ism_put_vlan(ini->ism_dev[ini->ism_selected], ini->vlan_id);
+out:
+	if (rc < 0) {
+		if (rc == -ENOMEM)
+			rc = SMC_CLC_DECL_MEM;
+		else
+			rc = SMC_CLC_DECL_INTERR;
+	}
+	return rc;
+}
+
+static int smc_write_space(struct smc_connection *conn)
+{
+	int buffer_len = conn->peer_rmbe_size;
+	union smc_host_cursor prod;
+	union smc_host_cursor cons;
+	int space;
+
+	smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
+	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
+	/* determine rx_buf space */
+	space = buffer_len - smc_curs_diff(buffer_len, &cons, &prod);
+	return space;
+}
+
+static int smc_switch_cursor(struct smc_sock *smc, struct smc_cdc_tx_pend *pend,
+			     struct smc_wr_buf *wr_buf)
+{
+	struct smc_connection *conn = &smc->conn;
+	union smc_host_cursor cons, fin;
+	int rc = 0;
+	int diff;
+
+	smc_curs_copy(&conn->tx_curs_sent, &conn->tx_curs_fin, conn);
+	smc_curs_copy(&fin, &conn->local_tx_ctrl_fin, conn);
+	/* set prod cursor to old state, enforce tx_rdma_writes() */
+	smc_curs_copy(&conn->local_tx_ctrl.prod, &fin, conn);
+	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
+
+	if (smc_curs_comp(conn->peer_rmbe_size, &cons, &fin) < 0) {
+		/* cons cursor advanced more than fin, and prod was set
+		 * fin above, so now prod is smaller than cons. Fix that.
+		 */
+		diff = smc_curs_diff(conn->peer_rmbe_size, &fin, &cons);
+		smc_curs_add(conn->sndbuf_desc->len,
+			     &conn->tx_curs_sent, diff);
+		smc_curs_add(conn->sndbuf_desc->len,
+			     &conn->tx_curs_fin, diff);
+
+		smp_mb__before_atomic();
+		atomic_add(diff, &conn->sndbuf_space);
+		smp_mb__after_atomic();
+
+		smc_curs_add(conn->peer_rmbe_size,
+			     &conn->local_tx_ctrl.prod, diff);
+		smc_curs_add(conn->peer_rmbe_size,
+			     &conn->local_tx_ctrl_fin, diff);
+	}
+	/* recalculate, value is used by tx_rdma_writes() */
+	atomic_set(&smc->conn.peer_rmbe_space, smc_write_space(conn));
+
+	if (smc->sk.sk_state != SMC_INIT &&
+	    smc->sk.sk_state != SMC_CLOSED) {
+		rc = smcr_cdc_msg_send_validation(conn, pend, wr_buf);
+		if (!rc) {
+			queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 0);
+			smc->sk.sk_data_ready(&smc->sk);
+		}
+	} else {
+		smc_wr_tx_put_slot(conn->lnk,
+				   (struct smc_wr_tx_pend_priv *)pend);
+	}
+	return rc;
+}
+
+void smc_switch_link_and_count(struct smc_connection *conn,
+			       struct smc_link *to_lnk)
+{
+	atomic_dec(&conn->lnk->conn_cnt);
+	/* link_hold in smc_conn_create() */
+	smcr_link_put(conn->lnk);
+	conn->lnk = to_lnk;
+	atomic_inc(&conn->lnk->conn_cnt);
+	/* link_put in smc_conn_free() */
+	smcr_link_hold(conn->lnk);
+}
+
+struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
+				  struct smc_link *from_lnk, bool is_dev_err)
+{
+	struct smc_link *to_lnk = NULL;
+	struct smc_cdc_tx_pend *pend;
+	struct smc_connection *conn;
+	struct smc_wr_buf *wr_buf;
+	struct smc_sock *smc;
+	struct rb_node *node;
+	int i, rc = 0;
+
+	/* link is inactive, wake up tx waiters */
+	smc_wr_wakeup_tx_wait(from_lnk);
+
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+		if (!smc_link_active(&lgr->lnk[i]) || i == from_lnk->link_idx)
+			continue;
+		if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&
+		    from_lnk->ibport == lgr->lnk[i].ibport) {
+			continue;
+		}
+		to_lnk = &lgr->lnk[i];
+		break;
+	}
+	if (!to_lnk || !smc_wr_tx_link_hold(to_lnk)) {
+		smc_lgr_terminate_sched(lgr);
+		return NULL;
+	}
+again:
+	read_lock_bh(&lgr->conns_lock);
+	for (node = rb_first(&lgr->conns_all); node; node = rb_next(node)) {
+		conn = rb_entry(node, struct smc_connection, alert_node);
+		if (conn->lnk != from_lnk)
+			continue;
+		smc = container_of(conn, struct smc_sock, conn);
+		/* conn->lnk not yet set in SMC_INIT state */
+		if (smc->sk.sk_state == SMC_INIT)
+			continue;
+		if (smc->sk.sk_state == SMC_CLOSED ||
+		    smc->sk.sk_state == SMC_PEERCLOSEWAIT1 ||
+		    smc->sk.sk_state == SMC_PEERCLOSEWAIT2 ||
+		    smc->sk.sk_state == SMC_APPFINCLOSEWAIT ||
+		    smc->sk.sk_state == SMC_APPCLOSEWAIT1 ||
+		    smc->sk.sk_state == SMC_APPCLOSEWAIT2 ||
+		    smc->sk.sk_state == SMC_PEERFINCLOSEWAIT ||
+		    smc->sk.sk_state == SMC_PEERABORTWAIT ||
+		    smc->sk.sk_state == SMC_PROCESSABORT) {
+			spin_lock_bh(&conn->send_lock);
+			smc_switch_link_and_count(conn, to_lnk);
+			spin_unlock_bh(&conn->send_lock);
+			continue;
+		}
+		sock_hold(&smc->sk);
+		read_unlock_bh(&lgr->conns_lock);
+		/* pre-fetch buffer outside of send_lock, might sleep */
+		rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
+		if (rc)
+			goto err_out;
+		/* avoid race with smcr_tx_sndbuf_nonempty() */
+		spin_lock_bh(&conn->send_lock);
+		smc_switch_link_and_count(conn, to_lnk);
+		rc = smc_switch_cursor(smc, pend, wr_buf);
+		spin_unlock_bh(&conn->send_lock);
+		sock_put(&smc->sk);
+		if (rc)
+			goto err_out;
+		goto again;
+	}
+	read_unlock_bh(&lgr->conns_lock);
+	smc_wr_tx_link_put(to_lnk);
+	return to_lnk;
+
+err_out:
+	smcr_link_down_cond_sched(to_lnk);
+	smc_wr_tx_link_put(to_lnk);
+	return NULL;
+}
+
+static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb,
+			   struct smc_link_group *lgr)
+{
+	struct rw_semaphore *lock;	/* lock buffer list */
+	int rc;
+
+	if (is_rmb && buf_desc->is_conf_rkey && !list_empty(&lgr->list)) {
+		/* unregister rmb with peer */
+		rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
+		if (!rc) {
+			/* protect against smc_llc_cli_rkey_exchange() */
+			down_read(&lgr->llc_conf_mutex);
+			smc_llc_do_delete_rkey(lgr, buf_desc);
+			buf_desc->is_conf_rkey = false;
+			up_read(&lgr->llc_conf_mutex);
+			smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
+		}
+	}
+
+	if (buf_desc->is_reg_err) {
+		/* buf registration failed, reuse not possible */
+		lock = is_rmb ? &lgr->rmbs_lock :
+				&lgr->sndbufs_lock;
+		down_write(lock);
+		list_del(&buf_desc->list);
+		up_write(lock);
+
+		smc_buf_free(lgr, is_rmb, buf_desc);
+	} else {
+		/* memzero_explicit provides potential memory barrier semantics */
+		memzero_explicit(buf_desc->cpu_addr, buf_desc->len);
+		WRITE_ONCE(buf_desc->used, 0);
+	}
+}
+
+static void smc_buf_unuse(struct smc_connection *conn,
+			  struct smc_link_group *lgr)
+{
+	if (conn->sndbuf_desc) {
+		if (!lgr->is_smcd && conn->sndbuf_desc->is_vm) {
+			smcr_buf_unuse(conn->sndbuf_desc, false, lgr);
+		} else {
+			memzero_explicit(conn->sndbuf_desc->cpu_addr, conn->sndbuf_desc->len);
+			WRITE_ONCE(conn->sndbuf_desc->used, 0);
+		}
+	}
+	if (conn->rmb_desc) {
+		if (!lgr->is_smcd) {
+			smcr_buf_unuse(conn->rmb_desc, true, lgr);
+		} else {
+			memzero_explicit(conn->rmb_desc->cpu_addr,
+					 conn->rmb_desc->len + sizeof(struct smcd_cdc_msg));
+			WRITE_ONCE(conn->rmb_desc->used, 0);
+		}
+	}
+}
+
+/* remove a finished connection from its link group */
+void smc_conn_free(struct smc_connection *conn)
+{
+	struct smc_link_group *lgr = conn->lgr;
+
+	if (!lgr || conn->freed)
+		/* Connection has never been registered in a
+		 * link group, or has already been freed.
+		 */
+		return;
+
+	conn->freed = 1;
+	if (!smc_conn_lgr_valid(conn))
+		/* Connection has already unregistered from
+		 * link group.
+		 */
+		goto lgr_put;
+
+	if (lgr->is_smcd) {
+		if (!list_empty(&lgr->list))
+			smc_ism_unset_conn(conn);
+		tasklet_kill(&conn->rx_tsklet);
+	} else {
+		smc_cdc_wait_pend_tx_wr(conn);
+		if (current_work() != &conn->abort_work)
+			cancel_work_sync(&conn->abort_work);
+	}
+	if (!list_empty(&lgr->list)) {
+		smc_buf_unuse(conn, lgr); /* allow buffer reuse */
+		smc_lgr_unregister_conn(conn);
+	}
+
+	if (!lgr->conns_num)
+		smc_lgr_schedule_free_work(lgr);
+lgr_put:
+	if (!lgr->is_smcd)
+		smcr_link_put(conn->lnk); /* link_hold in smc_conn_create() */
+	smc_lgr_put(lgr); /* lgr_hold in smc_conn_create() */
+}
+
+/* unregister a link from a buf_desc */
+static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
+				struct smc_link *lnk)
+{
+	if (is_rmb || buf_desc->is_vm)
+		buf_desc->is_reg_mr[lnk->link_idx] = false;
+	if (!buf_desc->is_map_ib[lnk->link_idx])
+		return;
+
+	if ((is_rmb || buf_desc->is_vm) &&
+	    buf_desc->mr[lnk->link_idx]) {
+		smc_ib_put_memory_region(buf_desc->mr[lnk->link_idx]);
+		buf_desc->mr[lnk->link_idx] = NULL;
+	}
+	if (is_rmb)
+		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
+	else
+		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
+
+	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
+	buf_desc->is_map_ib[lnk->link_idx] = false;
+}
+
+/* unmap all buffers of lgr for a deleted link */
+static void smcr_buf_unmap_lgr(struct smc_link *lnk)
+{
+	struct smc_link_group *lgr = lnk->lgr;
+	struct smc_buf_desc *buf_desc, *bf;
+	int i;
+
+	for (i = 0; i < SMC_RMBE_SIZES; i++) {
+		down_write(&lgr->rmbs_lock);
+		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
+			smcr_buf_unmap_link(buf_desc, true, lnk);
+		up_write(&lgr->rmbs_lock);
+
+		down_write(&lgr->sndbufs_lock);
+		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
+					 list)
+			smcr_buf_unmap_link(buf_desc, false, lnk);
+		up_write(&lgr->sndbufs_lock);
+	}
+}
+
+static void smcr_rtoken_clear_link(struct smc_link *lnk)
+{
+	struct smc_link_group *lgr = lnk->lgr;
+	int i;
+
+	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
+		lgr->rtokens[i][lnk->link_idx].rkey = 0;
+		lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
+	}
+}
+
+static void __smcr_link_clear(struct smc_link *lnk)
+{
+	struct smc_link_group *lgr = lnk->lgr;
+	struct smc_ib_device *smcibdev;
+
+	smc_wr_free_link_mem(lnk);
+	smc_ibdev_cnt_dec(lnk);
+	put_device(&lnk->smcibdev->ibdev->dev);
+	smcibdev = lnk->smcibdev;
+	memset(lnk, 0, sizeof(struct smc_link));
+	lnk->state = SMC_LNK_UNUSED;
+	if (!atomic_dec_return(&smcibdev->lnk_cnt))
+		wake_up(&smcibdev->lnks_deleted);
+	smc_lgr_put(lgr); /* lgr_hold in smcr_link_init() */
+}
+
+/* must be called under lgr->llc_conf_mutex lock */
+void smcr_link_clear(struct smc_link *lnk, bool log)
+{
+	if (!lnk->lgr || lnk->clearing ||
+	    lnk->state == SMC_LNK_UNUSED)
+		return;
+	lnk->clearing = 1;
+	lnk->peer_qpn = 0;
+	smc_llc_link_clear(lnk, log);
+	smcr_buf_unmap_lgr(lnk);
+	smcr_rtoken_clear_link(lnk);
+	smc_ib_modify_qp_error(lnk);
+	smc_wr_free_link(lnk);
+	smc_ib_destroy_queue_pair(lnk);
+	smc_ib_dealloc_protection_domain(lnk);
+	smcr_link_put(lnk); /* theoretically last link_put */
+}
+
+void smcr_link_hold(struct smc_link *lnk)
+{
+	refcount_inc(&lnk->refcnt);
+}
+
+void smcr_link_put(struct smc_link *lnk)
+{
+	if (refcount_dec_and_test(&lnk->refcnt))
+		__smcr_link_clear(lnk);
+}
+
+static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
+			  struct smc_buf_desc *buf_desc)
+{
+	int i;
+
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
+		smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);
+
+	if (!buf_desc->is_vm && buf_desc->pages)
+		__free_pages(buf_desc->pages, buf_desc->order);
+	else if (buf_desc->is_vm && buf_desc->cpu_addr)
+		vfree(buf_desc->cpu_addr);
+	kfree(buf_desc);
+}
+
+static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
+			  struct smc_buf_desc *buf_desc)
+{
+	if (is_dmb) {
+		/* restore original buf len */
+		buf_desc->len += sizeof(struct smcd_cdc_msg);
+		smc_ism_unregister_dmb(lgr->smcd, buf_desc);
+	} else {
+		kfree(buf_desc->cpu_addr);
+	}
+	kfree(buf_desc);
+}
+
+static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
+			 struct smc_buf_desc *buf_desc)
+{
+	if (lgr->is_smcd)
+		smcd_buf_free(lgr, is_rmb, buf_desc);
+	else
+		smcr_buf_free(lgr, is_rmb, buf_desc);
+}
+
+static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
+{
+	struct smc_buf_desc *buf_desc, *bf_desc;
+	struct list_head *buf_list;
+	int i;
+
+	for (i = 0; i < SMC_RMBE_SIZES; i++) {
+		if (is_rmb)
+			buf_list = &lgr->rmbs[i];
+		else
+			buf_list = &lgr->sndbufs[i];
+		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
+					 list) {
+			list_del(&buf_desc->list);
+			smc_buf_free(lgr, is_rmb, buf_desc);
+		}
+	}
+}
+
+static void smc_lgr_free_bufs(struct smc_link_group *lgr)
+{
+	/* free send buffers */
+	__smc_lgr_free_bufs(lgr, false);
+	/* free rmbs */
+	__smc_lgr_free_bufs(lgr, true);
+}
+
+/* won't be freed until no one accesses to lgr anymore */
+static void __smc_lgr_free(struct smc_link_group *lgr)
+{
+	smc_lgr_free_bufs(lgr);
+	if (lgr->is_smcd) {
+		if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
+			wake_up(&lgr->smcd->lgrs_deleted);
+	} else {
+		smc_wr_free_lgr_mem(lgr);
+		if (!atomic_dec_return(&lgr_cnt))
+			wake_up(&lgrs_deleted);
+	}
+	kfree(lgr);
+}
+
+/* remove a link group */
+static void smc_lgr_free(struct smc_link_group *lgr)
+{
+	int i;
+
+	if (!lgr->is_smcd) {
+		down_write(&lgr->llc_conf_mutex);
+		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+			if (lgr->lnk[i].state != SMC_LNK_UNUSED)
+				smcr_link_clear(&lgr->lnk[i], false);
+		}
+		up_write(&lgr->llc_conf_mutex);
+		smc_llc_lgr_clear(lgr);
+	}
+
+	destroy_workqueue(lgr->tx_wq);
+	if (lgr->is_smcd) {
+		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
+		put_device(lgr->smcd->ops->get_dev(lgr->smcd));
+	}
+	smc_lgr_put(lgr); /* theoretically last lgr_put */
+}
+
+void smc_lgr_hold(struct smc_link_group *lgr)
+{
+	refcount_inc(&lgr->refcnt);
+}
+
+void smc_lgr_put(struct smc_link_group *lgr)
+{
+	if (refcount_dec_and_test(&lgr->refcnt))
+		__smc_lgr_free(lgr);
+}
+
+static void smc_sk_wake_ups(struct smc_sock *smc)
+{
+	smc->sk.sk_write_space(&smc->sk);
+	smc->sk.sk_data_ready(&smc->sk);
+	smc->sk.sk_state_change(&smc->sk);
+}
+
+/* kill a connection */
+static void smc_conn_kill(struct smc_connection *conn, bool soft)
+{
+	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
+
+	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
+		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
+	else
+		smc_close_abort(conn);
+	conn->killed = 1;
+	smc->sk.sk_err = ECONNABORTED;
+	smc_sk_wake_ups(smc);
+	if (conn->lgr->is_smcd) {
+		smc_ism_unset_conn(conn);
+		if (soft)
+			tasklet_kill(&conn->rx_tsklet);
+		else
+			tasklet_unlock_wait(&conn->rx_tsklet);
+	} else {
+		smc_cdc_wait_pend_tx_wr(conn);
+	}
+	smc_lgr_unregister_conn(conn);
+	smc_close_active_abort(smc);
+}
+
+static void smc_lgr_cleanup(struct smc_link_group *lgr)
+{
+	if (lgr->is_smcd) {
+		smc_ism_signal_shutdown(lgr);
+	} else {
+		u32 rsn = lgr->llc_termination_rsn;
+
+		if (!rsn)
+			rsn = SMC_LLC_DEL_PROG_INIT_TERM;
+		smc_llc_send_link_delete_all(lgr, false, rsn);
+		smcr_lgr_link_deactivate_all(lgr);
+	}
+}
+
+/* terminate link group
+ * @soft: true if link group shutdown can take its time
+ *	  false if immediate link group shutdown is required
+ */
+static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
+{
+	struct smc_connection *conn;
+	struct smc_sock *smc;
+	struct rb_node *node;
+
+	if (lgr->terminating)
+		return;	/* lgr already terminating */
+	/* cancel free_work sync, will terminate when lgr->freeing is set */
+	cancel_delayed_work(&lgr->free_work);
+	lgr->terminating = 1;
+
+	/* kill remaining link group connections */
+	read_lock_bh(&lgr->conns_lock);
+	node = rb_first(&lgr->conns_all);
+	while (node) {
+		read_unlock_bh(&lgr->conns_lock);
+		conn = rb_entry(node, struct smc_connection, alert_node);
+		smc = container_of(conn, struct smc_sock, conn);
+		sock_hold(&smc->sk); /* sock_put below */
+		lock_sock(&smc->sk);
+		smc_conn_kill(conn, soft);
+		release_sock(&smc->sk);
+		sock_put(&smc->sk); /* sock_hold above */
+		read_lock_bh(&lgr->conns_lock);
+		node = rb_first(&lgr->conns_all);
+	}
+	read_unlock_bh(&lgr->conns_lock);
+	smc_lgr_cleanup(lgr);
+	smc_lgr_free(lgr);
+}
+
+/* unlink link group and schedule termination */
+void smc_lgr_terminate_sched(struct smc_link_group *lgr)
+{
+	spinlock_t *lgr_lock;
+
+	smc_lgr_list_head(lgr, &lgr_lock);
+	spin_lock_bh(lgr_lock);
+	if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
+		spin_unlock_bh(lgr_lock);
+		return;	/* lgr already terminating */
+	}
+	list_del_init(&lgr->list);
+	lgr->freeing = 1;
+	spin_unlock_bh(lgr_lock);
+	schedule_work(&lgr->terminate_work);
+}
+
+/* Called when peer lgr shutdown (regularly or abnormally) is received */
+void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
+{
+	struct smc_link_group *lgr, *l;
+	LIST_HEAD(lgr_free_list);
+
+	/* run common cleanup function and build free list */
+	spin_lock_bh(&dev->lgr_lock);
+	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
+		if ((!peer_gid || lgr->peer_gid == peer_gid) &&
+		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
+			if (peer_gid) /* peer triggered termination */
+				lgr->peer_shutdown = 1;
+			list_move(&lgr->list, &lgr_free_list);
+			lgr->freeing = 1;
+		}
+	}
+	spin_unlock_bh(&dev->lgr_lock);
+
+	/* cancel the regular free workers and actually free lgrs */
+	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
+		list_del_init(&lgr->list);
+		schedule_work(&lgr->terminate_work);
+	}
+}
+
+/* Called when an SMCD device is removed or the smc module is unloaded */
+void smc_smcd_terminate_all(struct smcd_dev *smcd)
+{
+	struct smc_link_group *lgr, *lg;
+	LIST_HEAD(lgr_free_list);
+
+	spin_lock_bh(&smcd->lgr_lock);
+	list_splice_init(&smcd->lgr_list, &lgr_free_list);
+	list_for_each_entry(lgr, &lgr_free_list, list)
+		lgr->freeing = 1;
+	spin_unlock_bh(&smcd->lgr_lock);
+
+	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
+		list_del_init(&lgr->list);
+		__smc_lgr_terminate(lgr, false);
+	}
+
+	if (atomic_read(&smcd->lgr_cnt))
+		wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
+}
+
+/* Called when an SMCR device is removed or the smc module is unloaded.
+ * If smcibdev is given, all SMCR link groups using this device are terminated.
+ * If smcibdev is NULL, all SMCR link groups are terminated.
+ */
+void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
+{
+	struct smc_link_group *lgr, *lg;
+	LIST_HEAD(lgr_free_list);
+	int i;
+
+	spin_lock_bh(&smc_lgr_list.lock);
+	if (!smcibdev) {
+		list_splice_init(&smc_lgr_list.list, &lgr_free_list);
+		list_for_each_entry(lgr, &lgr_free_list, list)
+			lgr->freeing = 1;
+	} else {
+		list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
+			for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+				if (lgr->lnk[i].smcibdev == smcibdev)
+					smcr_link_down_cond_sched(&lgr->lnk[i]);
+			}
+		}
+	}
+	spin_unlock_bh(&smc_lgr_list.lock);
+
+	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
+		list_del_init(&lgr->list);
+		smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
+		__smc_lgr_terminate(lgr, false);
+	}
+
+	if (smcibdev) {
+		if (atomic_read(&smcibdev->lnk_cnt))
+			wait_event(smcibdev->lnks_deleted,
+				   !atomic_read(&smcibdev->lnk_cnt));
+	} else {
+		if (atomic_read(&lgr_cnt))
+			wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
+	}
+}
+
+/* set new lgr type and clear all asymmetric link tagging */
+void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
+{
+	char *lgr_type = "";
+	int i;
+
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
+		if (smc_link_usable(&lgr->lnk[i]))
+			lgr->lnk[i].link_is_asym = false;
+	if (lgr->type == new_type)
+		return;
+	lgr->type = new_type;
+
+	switch (lgr->type) {
+	case SMC_LGR_NONE:
+		lgr_type = "NONE";
+		break;
+	case SMC_LGR_SINGLE:
+		lgr_type = "SINGLE";
+		break;
+	case SMC_LGR_SYMMETRIC:
+		lgr_type = "SYMMETRIC";
+		break;
+	case SMC_LGR_ASYMMETRIC_PEER:
+		lgr_type = "ASYMMETRIC_PEER";
+		break;
+	case SMC_LGR_ASYMMETRIC_LOCAL:
+		lgr_type = "ASYMMETRIC_LOCAL";
+		break;
+	}
+	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu state changed: "
+			    "%s, pnetid %.16s\n", SMC_LGR_ID_SIZE, &lgr->id,
+			    lgr->net->net_cookie, lgr_type, lgr->pnet_id);
+}
+
+/* set new lgr type and tag a link as asymmetric */
+void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
+			    enum smc_lgr_type new_type, int asym_lnk_idx)
+{
+	smcr_lgr_set_type(lgr, new_type);
+	lgr->lnk[asym_lnk_idx].link_is_asym = true;
+}
+
+/* abort connection, abort_work scheduled from tasklet context */
+static void smc_conn_abort_work(struct work_struct *work)
+{
+	struct smc_connection *conn = container_of(work,
+						   struct smc_connection,
+						   abort_work);
+	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
+
+	lock_sock(&smc->sk);
+	smc_conn_kill(conn, true);
+	release_sock(&smc->sk);
+	sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
+}
+
+void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
+{
+	struct smc_link_group *lgr, *n;
+
+	spin_lock_bh(&smc_lgr_list.lock);
+	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
+		struct smc_link *link;
+
+		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
+			    SMC_MAX_PNETID_LEN) ||
+		    lgr->type == SMC_LGR_SYMMETRIC ||
+		    lgr->type == SMC_LGR_ASYMMETRIC_PEER ||
+		    !rdma_dev_access_netns(smcibdev->ibdev, lgr->net))
+			continue;
+
+		if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
+			continue;
+
+		/* trigger local add link processing */
+		link = smc_llc_usable_link(lgr);
+		if (link)
+			smc_llc_add_link_local(link);
+	}
+	spin_unlock_bh(&smc_lgr_list.lock);
+}
+
+/* link is down - switch connections to alternate link,
+ * must be called under lgr->llc_conf_mutex lock
+ */
+static void smcr_link_down(struct smc_link *lnk)
+{
+	struct smc_link_group *lgr = lnk->lgr;
+	struct smc_link *to_lnk;
+	int del_link_id;
+
+	if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
+		return;
+
+	to_lnk = smc_switch_conns(lgr, lnk, true);
+	if (!to_lnk) { /* no backup link available */
+		smcr_link_clear(lnk, true);
+		return;
+	}
+	smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
+	del_link_id = lnk->link_id;
+
+	if (lgr->role == SMC_SERV) {
+		/* trigger local delete link processing */
+		smc_llc_srv_delete_link_local(to_lnk, del_link_id);
+	} else {
+		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
+			/* another llc task is ongoing */
+			up_write(&lgr->llc_conf_mutex);
+			wait_event_timeout(lgr->llc_flow_waiter,
+				(list_empty(&lgr->list) ||
+				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
+				SMC_LLC_WAIT_TIME);
+			down_write(&lgr->llc_conf_mutex);
+		}
+		if (!list_empty(&lgr->list)) {
+			smc_llc_send_delete_link(to_lnk, del_link_id,
+						 SMC_LLC_REQ, true,
+						 SMC_LLC_DEL_LOST_PATH);
+			smcr_link_clear(lnk, true);
+		}
+		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
+	}
+}
+
+/* must be called under lgr->llc_conf_mutex lock */
+void smcr_link_down_cond(struct smc_link *lnk)
+{
+	if (smc_link_downing(&lnk->state)) {
+		trace_smcr_link_down(lnk, __builtin_return_address(0));
+		smcr_link_down(lnk);
+	}
+}
+
+/* will get the lgr->llc_conf_mutex lock */
+void smcr_link_down_cond_sched(struct smc_link *lnk)
+{
+	if (smc_link_downing(&lnk->state)) {
+		trace_smcr_link_down(lnk, __builtin_return_address(0));
+		schedule_work(&lnk->link_down_wrk);
+	}
+}
+
+void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
+{
+	struct smc_link_group *lgr, *n;
+	int i;
+
+	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
+		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
+			    SMC_MAX_PNETID_LEN))
+			continue; /* lgr is not affected */
+		if (list_empty(&lgr->list))
+			continue;
+		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+			struct smc_link *lnk = &lgr->lnk[i];
+
+			if (smc_link_usable(lnk) &&
+			    lnk->smcibdev == smcibdev && lnk->ibport == ibport)
+				smcr_link_down_cond_sched(lnk);
+		}
+	}
+}
+
+static void smc_link_down_work(struct work_struct *work)
+{
+	struct smc_link *link = container_of(work, struct smc_link,
+					     link_down_wrk);
+	struct smc_link_group *lgr = link->lgr;
+
+	if (list_empty(&lgr->list))
+		return;
+	wake_up_all(&lgr->llc_msg_waiter);
+	down_write(&lgr->llc_conf_mutex);
+	smcr_link_down(link);
+	up_write(&lgr->llc_conf_mutex);
+}
+
+static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev,
+				  struct netdev_nested_priv *priv)
+{
+	unsigned short *vlan_id = (unsigned short *)priv->data;
+
+	if (is_vlan_dev(lower_dev)) {
+		*vlan_id = vlan_dev_vlan_id(lower_dev);
+		return 1;
+	}
+
+	return 0;
+}
+
+/* Determine vlan of internal TCP socket. */
+int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
+{
+	struct dst_entry *dst = sk_dst_get(clcsock->sk);
+	struct netdev_nested_priv priv;
+	struct net_device *ndev;
+	int rc = 0;
+
+	ini->vlan_id = 0;
+	if (!dst) {
+		rc = -ENOTCONN;
+		goto out;
+	}
+	if (!dst->dev) {
+		rc = -ENODEV;
+		goto out_rel;
+	}
+
+	ndev = dst->dev;
+	if (is_vlan_dev(ndev)) {
+		ini->vlan_id = vlan_dev_vlan_id(ndev);
+		goto out_rel;
+	}
+
+	priv.data = (void *)&ini->vlan_id;
+	rtnl_lock();
+	netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv);
+	rtnl_unlock();
+
+out_rel:
+	dst_release(dst);
+out:
+	return rc;
+}
+
+static bool smcr_lgr_match(struct smc_link_group *lgr, u8 smcr_version,
+			   u8 peer_systemid[],
+			   u8 peer_gid[],
+			   u8 peer_mac_v1[],
+			   enum smc_lgr_role role, u32 clcqpn,
+			   struct net *net)
+{
+	struct smc_link *lnk;
+	int i;
+
+	if (memcmp(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN) ||
+	    lgr->role != role)
+		return false;
+
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+		lnk = &lgr->lnk[i];
+
+		if (!smc_link_active(lnk))
+			continue;
+		/* use verbs API to check netns, instead of lgr->net */
+		if (!rdma_dev_access_netns(lnk->smcibdev->ibdev, net))
+			return false;
+		if ((lgr->role == SMC_SERV || lnk->peer_qpn == clcqpn) &&
+		    !memcmp(lnk->peer_gid, peer_gid, SMC_GID_SIZE) &&
+		    (smcr_version == SMC_V2 ||
+		     !memcmp(lnk->peer_mac, peer_mac_v1, ETH_ALEN)))
+			return true;
+	}
+	return false;
+}
+
+static bool smcd_lgr_match(struct smc_link_group *lgr,
+			   struct smcd_dev *smcismdev, u64 peer_gid)
+{
+	return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
+}
+
+/* create a new SMC connection (and a new link group if necessary) */
+int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
+{
+	struct smc_connection *conn = &smc->conn;
+	struct net *net = sock_net(&smc->sk);
+	struct list_head *lgr_list;
+	struct smc_link_group *lgr;
+	enum smc_lgr_role role;
+	spinlock_t *lgr_lock;
+	int rc = 0;
+
+	lgr_list = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_list :
+				  &smc_lgr_list.list;
+	lgr_lock = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_lock :
+				  &smc_lgr_list.lock;
+	ini->first_contact_local = 1;
+	role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
+	if (role == SMC_CLNT && ini->first_contact_peer)
+		/* create new link group as well */
+		goto create;
+
+	/* determine if an existing link group can be reused */
+	spin_lock_bh(lgr_lock);
+	list_for_each_entry(lgr, lgr_list, list) {
+		write_lock_bh(&lgr->conns_lock);
+		if ((ini->is_smcd ?
+		     smcd_lgr_match(lgr, ini->ism_dev[ini->ism_selected],
+				    ini->ism_peer_gid[ini->ism_selected]) :
+		     smcr_lgr_match(lgr, ini->smcr_version,
+				    ini->peer_systemid,
+				    ini->peer_gid, ini->peer_mac, role,
+				    ini->ib_clcqpn, net)) &&
+		    !lgr->sync_err &&
+		    (ini->smcd_version == SMC_V2 ||
+		     lgr->vlan_id == ini->vlan_id) &&
+		    (role == SMC_CLNT || ini->is_smcd ||
+		    (lgr->conns_num < lgr->max_conns &&
+		      !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) {
+			/* link group found */
+			ini->first_contact_local = 0;
+			conn->lgr = lgr;
+			rc = smc_lgr_register_conn(conn, false);
+			write_unlock_bh(&lgr->conns_lock);
+			if (!rc && delayed_work_pending(&lgr->free_work))
+				cancel_delayed_work(&lgr->free_work);
+			break;
+		}
+		write_unlock_bh(&lgr->conns_lock);
+	}
+	spin_unlock_bh(lgr_lock);
+	if (rc)
+		return rc;
+
+	if (role == SMC_CLNT && !ini->first_contact_peer &&
+	    ini->first_contact_local) {
+		/* Server reuses a link group, but Client wants to start
+		 * a new one
+		 * send out_of_sync decline, reason synchr. error
+		 */
+		return SMC_CLC_DECL_SYNCERR;
+	}
+
+create:
+	if (ini->first_contact_local) {
+		rc = smc_lgr_create(smc, ini);
+		if (rc)
+			goto out;
+		lgr = conn->lgr;
+		write_lock_bh(&lgr->conns_lock);
+		rc = smc_lgr_register_conn(conn, true);
+		write_unlock_bh(&lgr->conns_lock);
+		if (rc) {
+			smc_lgr_cleanup_early(lgr);
+			goto out;
+		}
+	}
+	smc_lgr_hold(conn->lgr); /* lgr_put in smc_conn_free() */
+	if (!conn->lgr->is_smcd)
+		smcr_link_hold(conn->lnk); /* link_put in smc_conn_free() */
+	conn->freed = 0;
+	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
+	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
+	conn->urg_state = SMC_URG_READ;
+	init_waitqueue_head(&conn->cdc_pend_tx_wq);
+	INIT_WORK(&smc->conn.abort_work, smc_conn_abort_work);
+	if (ini->is_smcd) {
+		conn->rx_off = sizeof(struct smcd_cdc_msg);
+		smcd_cdc_rx_init(conn); /* init tasklet for this conn */
+	} else {
+		conn->rx_off = 0;
+	}
+#ifndef KERNEL_HAS_ATOMIC64
+	spin_lock_init(&conn->acurs_lock);
+#endif
+
+out:
+	return rc;
+}
+
+#define SMCD_DMBE_SIZES		6 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
+#define SMCR_RMBE_SIZES		5 /* 0 -> 16KB, 1 -> 32KB, .. 5 -> 512KB */
+
+/* convert the RMB size into the compressed notation (minimum 16K, see
+ * SMCD/R_DMBE_SIZES.
+ * In contrast to plain ilog2, this rounds towards the next power of 2,
+ * so the socket application gets at least its desired sndbuf / rcvbuf size.
+ */
+static u8 smc_compress_bufsize(int size, bool is_smcd, bool is_rmb)
+{
+	const unsigned int max_scat = SG_MAX_SINGLE_ALLOC * PAGE_SIZE;
+	u8 compressed;
+
+	if (size <= SMC_BUF_MIN_SIZE)
+		return 0;
+
+	size = (size - 1) >> 14;  /* convert to 16K multiple */
+	compressed = min_t(u8, ilog2(size) + 1,
+			   is_smcd ? SMCD_DMBE_SIZES : SMCR_RMBE_SIZES);
+
+	if (!is_smcd && is_rmb)
+		/* RMBs are backed by & limited to max size of scatterlists */
+		compressed = min_t(u8, compressed, ilog2(max_scat >> 14));
+
+	return compressed;
+}
+
+/* convert the RMB size from compressed notation into integer */
+int smc_uncompress_bufsize(u8 compressed)
+{
+	u32 size;
+
+	size = 0x00000001 << (((int)compressed) + 14);
+	return (int)size;
+}
+
+/* try to reuse a sndbuf or rmb description slot for a certain
+ * buffer size; if not available, return NULL
+ */
+static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
+					     struct rw_semaphore *lock,
+					     struct list_head *buf_list)
+{
+	struct smc_buf_desc *buf_slot;
+
+	down_read(lock);
+	list_for_each_entry(buf_slot, buf_list, list) {
+		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
+			up_read(lock);
+			return buf_slot;
+		}
+	}
+	up_read(lock);
+	return NULL;
+}
+
+/* one of the conditions for announcing a receiver's current window size is
+ * that it "results in a minimum increase in the window size of 10% of the
+ * receive buffer space" [RFC7609]
+ */
+static inline int smc_rmb_wnd_update_limit(int rmbe_size)
+{
+	return max_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
+}
+
+/* map an buf to a link */
+static int smcr_buf_map_link(struct smc_buf_desc *buf_desc, bool is_rmb,
+			     struct smc_link *lnk)
+{
+	int rc, i, nents, offset, buf_size, size, access_flags;
+	struct scatterlist *sg;
+	void *buf;
+
+	if (buf_desc->is_map_ib[lnk->link_idx])
+		return 0;
+
+	if (buf_desc->is_vm) {
+		buf = buf_desc->cpu_addr;
+		buf_size = buf_desc->len;
+		offset = offset_in_page(buf_desc->cpu_addr);
+		nents = PAGE_ALIGN(buf_size + offset) / PAGE_SIZE;
+	} else {
+		nents = 1;
+	}
+
+	rc = sg_alloc_table(&buf_desc->sgt[lnk->link_idx], nents, GFP_KERNEL);
+	if (rc)
+		return rc;
+
+	if (buf_desc->is_vm) {
+		/* virtually contiguous buffer */
+		for_each_sg(buf_desc->sgt[lnk->link_idx].sgl, sg, nents, i) {
+			size = min_t(int, PAGE_SIZE - offset, buf_size);
+			sg_set_page(sg, vmalloc_to_page(buf), size, offset);
+			buf += size / sizeof(*buf);
+			buf_size -= size;
+			offset = 0;
+		}
+	} else {
+		/* physically contiguous buffer */
+		sg_set_buf(buf_desc->sgt[lnk->link_idx].sgl,
+			   buf_desc->cpu_addr, buf_desc->len);
+	}
+
+	/* map sg table to DMA address */
+	rc = smc_ib_buf_map_sg(lnk, buf_desc,
+			       is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
+	/* SMC protocol depends on mapping to one DMA address only */
+	if (rc != nents) {
+		rc = -EAGAIN;
+		goto free_table;
+	}
+
+	buf_desc->is_dma_need_sync |=
+		smc_ib_is_sg_need_sync(lnk, buf_desc) << lnk->link_idx;
+
+	if (is_rmb || buf_desc->is_vm) {
+		/* create a new memory region for the RMB or vzalloced sndbuf */
+		access_flags = is_rmb ?
+			       IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
+			       IB_ACCESS_LOCAL_WRITE;
+
+		rc = smc_ib_get_memory_region(lnk->roce_pd, access_flags,
+					      buf_desc, lnk->link_idx);
+		if (rc)
+			goto buf_unmap;
+		smc_ib_sync_sg_for_device(lnk, buf_desc,
+					  is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
+	}
+	buf_desc->is_map_ib[lnk->link_idx] = true;
+	return 0;
+
+buf_unmap:
+	smc_ib_buf_unmap_sg(lnk, buf_desc,
+			    is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
+free_table:
+	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
+	return rc;
+}
+
+/* register a new buf on IB device, rmb or vzalloced sndbuf
+ * must be called under lgr->llc_conf_mutex lock
+ */
+int smcr_link_reg_buf(struct smc_link *link, struct smc_buf_desc *buf_desc)
+{
+	if (list_empty(&link->lgr->list))
+		return -ENOLINK;
+	if (!buf_desc->is_reg_mr[link->link_idx]) {
+		/* register memory region for new buf */
+		if (buf_desc->is_vm)
+			buf_desc->mr[link->link_idx]->iova =
+				(uintptr_t)buf_desc->cpu_addr;
+		if (smc_wr_reg_send(link, buf_desc->mr[link->link_idx])) {
+			buf_desc->is_reg_err = true;
+			return -EFAULT;
+		}
+		buf_desc->is_reg_mr[link->link_idx] = true;
+	}
+	return 0;
+}
+
+static int _smcr_buf_map_lgr(struct smc_link *lnk, struct rw_semaphore *lock,
+			     struct list_head *lst, bool is_rmb)
+{
+	struct smc_buf_desc *buf_desc, *bf;
+	int rc = 0;
+
+	down_write(lock);
+	list_for_each_entry_safe(buf_desc, bf, lst, list) {
+		if (!buf_desc->used)
+			continue;
+		rc = smcr_buf_map_link(buf_desc, is_rmb, lnk);
+		if (rc)
+			goto out;
+	}
+out:
+	up_write(lock);
+	return rc;
+}
+
+/* map all used buffers of lgr for a new link */
+int smcr_buf_map_lgr(struct smc_link *lnk)
+{
+	struct smc_link_group *lgr = lnk->lgr;
+	int i, rc = 0;
+
+	for (i = 0; i < SMC_RMBE_SIZES; i++) {
+		rc = _smcr_buf_map_lgr(lnk, &lgr->rmbs_lock,
+				       &lgr->rmbs[i], true);
+		if (rc)
+			return rc;
+		rc = _smcr_buf_map_lgr(lnk, &lgr->sndbufs_lock,
+				       &lgr->sndbufs[i], false);
+		if (rc)
+			return rc;
+	}
+	return 0;
+}
+
+/* register all used buffers of lgr for a new link,
+ * must be called under lgr->llc_conf_mutex lock
+ */
+int smcr_buf_reg_lgr(struct smc_link *lnk)
+{
+	struct smc_link_group *lgr = lnk->lgr;
+	struct smc_buf_desc *buf_desc, *bf;
+	int i, rc = 0;
+
+	/* reg all RMBs for a new link */
+	down_write(&lgr->rmbs_lock);
+	for (i = 0; i < SMC_RMBE_SIZES; i++) {
+		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) {
+			if (!buf_desc->used)
+				continue;
+			rc = smcr_link_reg_buf(lnk, buf_desc);
+			if (rc) {
+				up_write(&lgr->rmbs_lock);
+				return rc;
+			}
+		}
+	}
+	up_write(&lgr->rmbs_lock);
+
+	if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
+		return rc;
+
+	/* reg all vzalloced sndbufs for a new link */
+	down_write(&lgr->sndbufs_lock);
+	for (i = 0; i < SMC_RMBE_SIZES; i++) {
+		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i], list) {
+			if (!buf_desc->used || !buf_desc->is_vm)
+				continue;
+			rc = smcr_link_reg_buf(lnk, buf_desc);
+			if (rc) {
+				up_write(&lgr->sndbufs_lock);
+				return rc;
+			}
+		}
+	}
+	up_write(&lgr->sndbufs_lock);
+	return rc;
+}
+
+static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
+						bool is_rmb, int bufsize)
+{
+	struct smc_buf_desc *buf_desc;
+
+	/* try to alloc a new buffer */
+	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
+	if (!buf_desc)
+		return ERR_PTR(-ENOMEM);
+
+	switch (lgr->buf_type) {
+	case SMCR_PHYS_CONT_BUFS:
+	case SMCR_MIXED_BUFS:
+		buf_desc->order = get_order(bufsize);
+		buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
+					      __GFP_NOMEMALLOC | __GFP_COMP |
+					      __GFP_NORETRY | __GFP_ZERO,
+					      buf_desc->order);
+		if (buf_desc->pages) {
+			buf_desc->cpu_addr =
+				(void *)page_address(buf_desc->pages);
+			buf_desc->len = bufsize;
+			buf_desc->is_vm = false;
+			break;
+		}
+		if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
+			goto out;
+		fallthrough;	// try virtually continguous buf
+	case SMCR_VIRT_CONT_BUFS:
+		buf_desc->order = get_order(bufsize);
+		buf_desc->cpu_addr = vzalloc(PAGE_SIZE << buf_desc->order);
+		if (!buf_desc->cpu_addr)
+			goto out;
+		buf_desc->pages = NULL;
+		buf_desc->len = bufsize;
+		buf_desc->is_vm = true;
+		break;
+	}
+	return buf_desc;
+
+out:
+	kfree(buf_desc);
+	return ERR_PTR(-EAGAIN);
+}
+
+/* map buf_desc on all usable links,
+ * unused buffers stay mapped as long as the link is up
+ */
+static int smcr_buf_map_usable_links(struct smc_link_group *lgr,
+				     struct smc_buf_desc *buf_desc, bool is_rmb)
+{
+	int i, rc = 0, cnt = 0;
+
+	/* protect against parallel link reconfiguration */
+	down_read(&lgr->llc_conf_mutex);
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+		struct smc_link *lnk = &lgr->lnk[i];
+
+		if (!smc_link_usable(lnk))
+			continue;
+		if (smcr_buf_map_link(buf_desc, is_rmb, lnk)) {
+			rc = -ENOMEM;
+			goto out;
+		}
+		cnt++;
+	}
+out:
+	up_read(&lgr->llc_conf_mutex);
+	if (!rc && !cnt)
+		rc = -EINVAL;
+	return rc;
+}
+
+static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
+						bool is_dmb, int bufsize)
+{
+	struct smc_buf_desc *buf_desc;
+	int rc;
+
+	/* try to alloc a new DMB */
+	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
+	if (!buf_desc)
+		return ERR_PTR(-ENOMEM);
+	if (is_dmb) {
+		rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
+		if (rc) {
+			kfree(buf_desc);
+			if (rc == -ENOMEM)
+				return ERR_PTR(-EAGAIN);
+			if (rc == -ENOSPC)
+				return ERR_PTR(-ENOSPC);
+			return ERR_PTR(-EIO);
+		}
+		buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
+		/* CDC header stored in buf. So, pretend it was smaller */
+		buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
+	} else {
+		buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
+					     __GFP_NOWARN | __GFP_NORETRY |
+					     __GFP_NOMEMALLOC);
+		if (!buf_desc->cpu_addr) {
+			kfree(buf_desc);
+			return ERR_PTR(-EAGAIN);
+		}
+		buf_desc->len = bufsize;
+	}
+	return buf_desc;
+}
+
+static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
+{
+	struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
+	struct smc_connection *conn = &smc->conn;
+	struct smc_link_group *lgr = conn->lgr;
+	struct list_head *buf_list;
+	int bufsize, bufsize_comp;
+	struct rw_semaphore *lock;	/* lock buffer list */
+	bool is_dgraded = false;
+
+	if (is_rmb)
+		/* use socket recv buffer size (w/o overhead) as start value */
+		bufsize = smc->sk.sk_rcvbuf / 2;
+	else
+		/* use socket send buffer size (w/o overhead) as start value */
+		bufsize = smc->sk.sk_sndbuf / 2;
+
+	for (bufsize_comp = smc_compress_bufsize(bufsize, is_smcd, is_rmb);
+	     bufsize_comp >= 0; bufsize_comp--) {
+		if (is_rmb) {
+			lock = &lgr->rmbs_lock;
+			buf_list = &lgr->rmbs[bufsize_comp];
+		} else {
+			lock = &lgr->sndbufs_lock;
+			buf_list = &lgr->sndbufs[bufsize_comp];
+		}
+		bufsize = smc_uncompress_bufsize(bufsize_comp);
+
+		/* check for reusable slot in the link group */
+		buf_desc = smc_buf_get_slot(bufsize_comp, lock, buf_list);
+		if (buf_desc) {
+			buf_desc->is_dma_need_sync = 0;
+			SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
+			SMC_STAT_BUF_REUSE(smc, is_smcd, is_rmb);
+			break; /* found reusable slot */
+		}
+
+		if (is_smcd)
+			buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
+		else
+			buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
+
+		if (PTR_ERR(buf_desc) == -ENOMEM)
+			break;
+		if (IS_ERR(buf_desc)) {
+			if (!is_dgraded) {
+				is_dgraded = true;
+				SMC_STAT_RMB_DOWNGRADED(smc, is_smcd, is_rmb);
+			}
+			continue;
+		}
+
+		SMC_STAT_RMB_ALLOC(smc, is_smcd, is_rmb);
+		SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
+		buf_desc->used = 1;
+		down_write(lock);
+		list_add(&buf_desc->list, buf_list);
+		up_write(lock);
+		break; /* found */
+	}
+
+	if (IS_ERR(buf_desc))
+		return PTR_ERR(buf_desc);
+
+	if (!is_smcd) {
+		if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {
+			smcr_buf_unuse(buf_desc, is_rmb, lgr);
+			return -ENOMEM;
+		}
+	}
+
+	if (is_rmb) {
+		conn->rmb_desc = buf_desc;
+		conn->rmbe_size_comp = bufsize_comp;
+		smc->sk.sk_rcvbuf = bufsize * 2;
+		atomic_set(&conn->bytes_to_rcv, 0);
+		conn->rmbe_update_limit =
+			smc_rmb_wnd_update_limit(buf_desc->len);
+		if (is_smcd)
+			smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
+	} else {
+		conn->sndbuf_desc = buf_desc;
+		smc->sk.sk_sndbuf = bufsize * 2;
+		atomic_set(&conn->sndbuf_space, bufsize);
+	}
+	return 0;
+}
+
+void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
+{
+	if (!conn->sndbuf_desc->is_dma_need_sync)
+		return;
+	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd ||
+	    !smc_link_active(conn->lnk))
+		return;
+	smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
+}
+
+void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
+{
+	int i;
+
+	if (!conn->rmb_desc->is_dma_need_sync)
+		return;
+	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd)
+		return;
+	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+		if (!smc_link_active(&conn->lgr->lnk[i]))
+			continue;
+		smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,
+				       DMA_FROM_DEVICE);
+	}
+}
+
+/* create the send and receive buffer for an SMC socket;
+ * receive buffers are called RMBs;
+ * (even though the SMC protocol allows more than one RMB-element per RMB,
+ * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
+ * extra RMB for every connection in a link group
+ */
+int smc_buf_create(struct smc_sock *smc, bool is_smcd)
+{
+	int rc;
+
+	/* create send buffer */
+	rc = __smc_buf_create(smc, is_smcd, false);
+	if (rc)
+		return rc;
+	/* create rmb */
+	rc = __smc_buf_create(smc, is_smcd, true);
+	if (rc) {
+		down_write(&smc->conn.lgr->sndbufs_lock);
+		list_del(&smc->conn.sndbuf_desc->list);
+		up_write(&smc->conn.lgr->sndbufs_lock);
+		smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
+		smc->conn.sndbuf_desc = NULL;
+	}
+	return rc;
+}
+
+static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
+{
+	int i;
+
+	for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
+		if (!test_and_set_bit(i, lgr->rtokens_used_mask))
+			return i;
+	}
+	return -ENOSPC;
+}
+
+static int smc_rtoken_find_by_link(struct smc_link_group *lgr, int lnk_idx,
+				   u32 rkey)
+{
+	int i;
+
+	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
+		if (test_bit(i, lgr->rtokens_used_mask) &&
+		    lgr->rtokens[i][lnk_idx].rkey == rkey)
+			return i;
+	}
+	return -ENOENT;
+}
+
+/* set rtoken for a new link to an existing rmb */
+void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
+		    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey)
+{
+	int rtok_idx;
+
+	rtok_idx = smc_rtoken_find_by_link(lgr, link_idx, ntohl(nw_rkey_known));
+	if (rtok_idx == -ENOENT)
+		return;
+	lgr->rtokens[rtok_idx][link_idx_new].rkey = ntohl(nw_rkey);
+	lgr->rtokens[rtok_idx][link_idx_new].dma_addr = be64_to_cpu(nw_vaddr);
+}
+
+/* set rtoken for a new link whose link_id is given */
+void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
+		     __be64 nw_vaddr, __be32 nw_rkey)
+{
+	u64 dma_addr = be64_to_cpu(nw_vaddr);
+	u32 rkey = ntohl(nw_rkey);
+	bool found = false;
+	int link_idx;
+
+	for (link_idx = 0; link_idx < SMC_LINKS_PER_LGR_MAX; link_idx++) {
+		if (lgr->lnk[link_idx].link_id == link_id) {
+			found = true;
+			break;
+		}
+	}
+	if (!found)
+		return;
+	lgr->rtokens[rtok_idx][link_idx].rkey = rkey;
+	lgr->rtokens[rtok_idx][link_idx].dma_addr = dma_addr;
+}
+
+/* add a new rtoken from peer */
+int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey)
+{
+	struct smc_link_group *lgr = smc_get_lgr(lnk);
+	u64 dma_addr = be64_to_cpu(nw_vaddr);
+	u32 rkey = ntohl(nw_rkey);
+	int i;
+
+	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
+		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
+		    lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr &&
+		    test_bit(i, lgr->rtokens_used_mask)) {
+			/* already in list */
+			return i;
+		}
+	}
+	i = smc_rmb_reserve_rtoken_idx(lgr);
+	if (i < 0)
+		return i;
+	lgr->rtokens[i][lnk->link_idx].rkey = rkey;
+	lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr;
+	return i;
+}
+
+/* delete an rtoken from all links */
+int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey)
+{
+	struct smc_link_group *lgr = smc_get_lgr(lnk);
+	u32 rkey = ntohl(nw_rkey);
+	int i, j;
+
+	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
+		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
+		    test_bit(i, lgr->rtokens_used_mask)) {
+			for (j = 0; j < SMC_LINKS_PER_LGR_MAX; j++) {
+				lgr->rtokens[i][j].rkey = 0;
+				lgr->rtokens[i][j].dma_addr = 0;
+			}
+			clear_bit(i, lgr->rtokens_used_mask);
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
+/* save rkey and dma_addr received from peer during clc handshake */
+int smc_rmb_rtoken_handling(struct smc_connection *conn,
+			    struct smc_link *lnk,
+			    struct smc_clc_msg_accept_confirm *clc)
+{
+	conn->rtoken_idx = smc_rtoken_add(lnk, clc->r0.rmb_dma_addr,
+					  clc->r0.rmb_rkey);
+	if (conn->rtoken_idx < 0)
+		return conn->rtoken_idx;
+	return 0;
+}
+
+static void smc_core_going_away(void)
+{
+	struct smc_ib_device *smcibdev;
+	struct smcd_dev *smcd;
+
+	mutex_lock(&smc_ib_devices.mutex);
+	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
+		int i;
+
+		for (i = 0; i < SMC_MAX_PORTS; i++)
+			set_bit(i, smcibdev->ports_going_away);
+	}
+	mutex_unlock(&smc_ib_devices.mutex);
+
+	mutex_lock(&smcd_dev_list.mutex);
+	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
+		smcd->going_away = 1;
+	}
+	mutex_unlock(&smcd_dev_list.mutex);
+}
+
+/* Clean up all SMC link groups */
+static void smc_lgrs_shutdown(void)
+{
+	struct smcd_dev *smcd;
+
+	smc_core_going_away();
+
+	smc_smcr_terminate_all(NULL);
+
+	mutex_lock(&smcd_dev_list.mutex);
+	list_for_each_entry(smcd, &smcd_dev_list.list, list)
+		smc_smcd_terminate_all(smcd);
+	mutex_unlock(&smcd_dev_list.mutex);
+}
+
+static int smc_core_reboot_event(struct notifier_block *this,
+				 unsigned long event, void *ptr)
+{
+	smc_lgrs_shutdown();
+	smc_ib_unregister_client();
+	smc_ism_exit();
+	return 0;
+}
+
+static struct notifier_block smc_reboot_notifier = {
+	.notifier_call = smc_core_reboot_event,
+};
+
+int __init smc_core_init(void)
+{
+	return register_reboot_notifier(&smc_reboot_notifier);
+}
+
+/* Called (from smc_exit) when module is removed */
+void smc_core_exit(void)
+{
+	unregister_reboot_notifier(&smc_reboot_notifier);
+	smc_lgrs_shutdown();
+}