[PATCH net 0/5] net/smc: fixes 2020-07-08

[PATCH net 0/5] net/smc: fixes 2020-07-08

[Karsten Graul]

Please apply the following patch series for smc to netdev's net tree.

The patches fix problems found during more testing of SMC
functionality, resulting in hang conditions and unneeded link
deactivations. The clc module was hardened to be prepared for
possible future SMCD versions.

Thanks,
Karsten

Karsten Graul (2):
  net/smc: separate LLC wait queues for flow and messages
  net/smc: fix work request handling

Ursula Braun (3):
  net/smc: fix sleep bug in smc_pnet_find_roce_resource()
  net/smc: switch smcd_dev_list spinlock to mutex
  net/smc: tolerate future SMCD versions

 net/smc/smc_clc.c  | 45 ++++++++++++++++-------
 net/smc/smc_clc.h  |  2 +
 net/smc/smc_core.c | 51 +++++++++++++++-----------
 net/smc/smc_core.h |  4 +-
 net/smc/smc_ib.c   | 11 +++---
 net/smc/smc_ib.h   |  3 +-
 net/smc/smc_ism.c  | 11 +++---
 net/smc/smc_ism.h  |  3 +-
 net/smc/smc_llc.c  | 91 ++++++++++++++++++++++++++++------------------
 net/smc/smc_pnet.c | 37 ++++++++++---------
 net/smc/smc_wr.c   | 10 +++--
 11 files changed, 163 insertions(+), 105 deletions(-)

-- 
2.17.1

[PATCH net 1/5] net/smc: separate LLC wait queues for flow and messages

[Karsten Graul]

There might be races in scenarios where both SMC link groups are on the
same system. Prevent that by creating separate wait queues for LLC flows
and messages. Switch to non-interruptable versions of wait_event() and
wake_up() for the llc flow waiter to make sure the waiters get control
sequentially. Fine tune the llc_flow_lock to include the assignment of
the message. Write to system log when an unexpected message was
dropped. And remove an extra indirection and use the existing local
variable lgr in smc_llc_enqueue().

Fixes: 555da9af827d ("net/smc: add event-based llc_flow framework")
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
 net/smc/smc_core.c | 38 ++++++++++++---------
 net/smc/smc_core.h |  4 ++-
 net/smc/smc_llc.c  | 83 +++++++++++++++++++++++++++++-----------------
 3 files changed, 77 insertions(+), 48 deletions(-)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 7964a21e5e6f..d695ce71837e 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -247,7 +247,8 @@ static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
 		if (smc_link_usable(lnk))
 			lnk->state = SMC_LNK_INACTIVE;
 	}
-	wake_up_interruptible_all(&lgr->llc_waiter);
+	wake_up_all(&lgr->llc_msg_waiter);
+	wake_up_all(&lgr->llc_flow_waiter);
 }
 
 static void smc_lgr_free(struct smc_link_group *lgr);
@@ -1130,18 +1131,19 @@ static void smcr_link_up(struct smc_link_group *lgr,
 			return;
 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
 			/* some other llc task is ongoing */
-			wait_event_interruptible_timeout(lgr->llc_waiter,
-				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
+			wait_event_timeout(lgr->llc_flow_waiter,
+				(list_empty(&lgr->list) ||
+				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
 				SMC_LLC_WAIT_TIME);
 		}
-		if (list_empty(&lgr->list) ||
-		    !smc_ib_port_active(smcibdev, ibport))
-			return; /* lgr or device no longer active */
-		link = smc_llc_usable_link(lgr);
-		if (!link)
-			return;
-		smc_llc_send_add_link(link, smcibdev->mac[ibport - 1], gid,
-				      NULL, SMC_LLC_REQ);
+		/* lgr or device no longer active? */
+		if (!list_empty(&lgr->list) &&
+		    smc_ib_port_active(smcibdev, ibport))
+			link = smc_llc_usable_link(lgr);
+		if (link)
+			smc_llc_send_add_link(link, smcibdev->mac[ibport - 1],
+					      gid, NULL, SMC_LLC_REQ);
+		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
 	}
 }
 
@@ -1195,13 +1197,17 @@ static void smcr_link_down(struct smc_link *lnk)
 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
 			/* another llc task is ongoing */
 			mutex_unlock(&lgr->llc_conf_mutex);
-			wait_event_interruptible_timeout(lgr->llc_waiter,
-				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
+			wait_event_timeout(lgr->llc_flow_waiter,
+				(list_empty(&lgr->list) ||
+				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
 				SMC_LLC_WAIT_TIME);
 			mutex_lock(&lgr->llc_conf_mutex);
 		}
-		smc_llc_send_delete_link(to_lnk, del_link_id, SMC_LLC_REQ, true,
-					 SMC_LLC_DEL_LOST_PATH);
+		if (!list_empty(&lgr->list))
+			smc_llc_send_delete_link(to_lnk, del_link_id,
+						 SMC_LLC_REQ, true,
+						 SMC_LLC_DEL_LOST_PATH);
+		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
 	}
 }
 
@@ -1262,7 +1268,7 @@ static void smc_link_down_work(struct work_struct *work)
 
 	if (list_empty(&lgr->list))
 		return;
-	wake_up_interruptible_all(&lgr->llc_waiter);
+	wake_up_all(&lgr->llc_msg_waiter);
 	mutex_lock(&lgr->llc_conf_mutex);
 	smcr_link_down(link);
 	mutex_unlock(&lgr->llc_conf_mutex);
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 86d160f0d187..c3ff512fd891 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -262,8 +262,10 @@ struct smc_link_group {
 			struct work_struct	llc_del_link_work;
 			struct work_struct	llc_event_work;
 						/* llc event worker */
-			wait_queue_head_t	llc_waiter;
+			wait_queue_head_t	llc_flow_waiter;
 						/* w4 next llc event */
+			wait_queue_head_t	llc_msg_waiter;
+						/* w4 next llc msg */
 			struct smc_llc_flow	llc_flow_lcl;
 						/* llc local control field */
 			struct smc_llc_flow	llc_flow_rmt;
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 391237b601fe..df164232574b 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -186,6 +186,26 @@ static inline void smc_llc_flow_qentry_set(struct smc_llc_flow *flow,
 	flow->qentry = qentry;
 }
 
+static void smc_llc_flow_parallel(struct smc_link_group *lgr, u8 flow_type,
+				  struct smc_llc_qentry *qentry)
+{
+	u8 msg_type = qentry->msg.raw.hdr.common.type;
+
+	if ((msg_type == SMC_LLC_ADD_LINK || msg_type == SMC_LLC_DELETE_LINK) &&
+	    flow_type != msg_type && !lgr->delayed_event) {
+		lgr->delayed_event = qentry;
+		return;
+	}
+	/* drop parallel or already-in-progress llc requests */
+	if (flow_type != msg_type)
+		pr_warn_once("smc: SMC-R lg %*phN dropped parallel "
+			     "LLC msg: msg %d flow %d role %d\n",
+			     SMC_LGR_ID_SIZE, &lgr->id,
+			     qentry->msg.raw.hdr.common.type,
+			     flow_type, lgr->role);
+	kfree(qentry);
+}
+
 /* try to start a new llc flow, initiated by an incoming llc msg */
 static bool smc_llc_flow_start(struct smc_llc_flow *flow,
 			       struct smc_llc_qentry *qentry)
@@ -195,14 +215,7 @@ static bool smc_llc_flow_start(struct smc_llc_flow *flow,
 	spin_lock_bh(&lgr->llc_flow_lock);
 	if (flow->type) {
 		/* a flow is already active */
-		if ((qentry->msg.raw.hdr.common.type == SMC_LLC_ADD_LINK ||
-		     qentry->msg.raw.hdr.common.type == SMC_LLC_DELETE_LINK) &&
-		    !lgr->delayed_event) {
-			lgr->delayed_event = qentry;
-		} else {
-			/* forget this llc request */
-			kfree(qentry);
-		}
+		smc_llc_flow_parallel(lgr, flow->type, qentry);
 		spin_unlock_bh(&lgr->llc_flow_lock);
 		return false;
 	}
@@ -222,8 +235,8 @@ static bool smc_llc_flow_start(struct smc_llc_flow *flow,
 	}
 	if (qentry == lgr->delayed_event)
 		lgr->delayed_event = NULL;
-	spin_unlock_bh(&lgr->llc_flow_lock);
 	smc_llc_flow_qentry_set(flow, qentry);
+	spin_unlock_bh(&lgr->llc_flow_lock);
 	return true;
 }
 
@@ -251,11 +264,11 @@ int smc_llc_flow_initiate(struct smc_link_group *lgr,
 		return 0;
 	}
 	spin_unlock_bh(&lgr->llc_flow_lock);
-	rc = wait_event_interruptible_timeout(lgr->llc_waiter,
-			(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
-			 (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
-			  lgr->llc_flow_rmt.type == allowed_remote)),
-			SMC_LLC_WAIT_TIME);
+	rc = wait_event_timeout(lgr->llc_flow_waiter, (list_empty(&lgr->list) ||
+				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
+				 (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
+				  lgr->llc_flow_rmt.type == allowed_remote))),
+				SMC_LLC_WAIT_TIME * 10);
 	if (!rc)
 		return -ETIMEDOUT;
 	goto again;
@@ -272,7 +285,7 @@ void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow)
 	    flow == &lgr->llc_flow_lcl)
 		schedule_work(&lgr->llc_event_work);
 	else
-		wake_up_interruptible(&lgr->llc_waiter);
+		wake_up(&lgr->llc_flow_waiter);
 }
 
 /* lnk is optional and used for early wakeup when link goes down, useful in
@@ -283,26 +296,32 @@ struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr,
 				    int time_out, u8 exp_msg)
 {
 	struct smc_llc_flow *flow = &lgr->llc_flow_lcl;
+	u8 rcv_msg;
 
-	wait_event_interruptible_timeout(lgr->llc_waiter,
-					 (flow->qentry ||
-					  (lnk && !smc_link_usable(lnk)) ||
-					  list_empty(&lgr->list)),
-					 time_out);
+	wait_event_timeout(lgr->llc_msg_waiter,
+			   (flow->qentry ||
+			    (lnk && !smc_link_usable(lnk)) ||
+			    list_empty(&lgr->list)),
+			   time_out);
 	if (!flow->qentry ||
 	    (lnk && !smc_link_usable(lnk)) || list_empty(&lgr->list)) {
 		smc_llc_flow_qentry_del(flow);
 		goto out;
 	}
-	if (exp_msg && flow->qentry->msg.raw.hdr.common.type != exp_msg) {
+	rcv_msg = flow->qentry->msg.raw.hdr.common.type;
+	if (exp_msg && rcv_msg != exp_msg) {
 		if (exp_msg == SMC_LLC_ADD_LINK &&
-		    flow->qentry->msg.raw.hdr.common.type ==
-		    SMC_LLC_DELETE_LINK) {
+		    rcv_msg == SMC_LLC_DELETE_LINK) {
 			/* flow_start will delay the unexpected msg */
 			smc_llc_flow_start(&lgr->llc_flow_lcl,
 					   smc_llc_flow_qentry_clr(flow));
 			return NULL;
 		}
+		pr_warn_once("smc: SMC-R lg %*phN dropped unexpected LLC msg: "
+			     "msg %d exp %d flow %d role %d flags %x\n",
+			     SMC_LGR_ID_SIZE, &lgr->id, rcv_msg, exp_msg,
+			     flow->type, lgr->role,
+			     flow->qentry->msg.raw.hdr.flags);
 		smc_llc_flow_qentry_del(flow);
 	}
 out:
@@ -1459,7 +1478,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
 				/* a flow is waiting for this message */
 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
 							qentry);
-				wake_up_interruptible(&lgr->llc_waiter);
+				wake_up(&lgr->llc_msg_waiter);
 			} else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
 						      qentry)) {
 				schedule_work(&lgr->llc_add_link_work);
@@ -1474,7 +1493,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
 			/* a flow is waiting for this message */
 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
-			wake_up_interruptible(&lgr->llc_waiter);
+			wake_up(&lgr->llc_msg_waiter);
 			return;
 		}
 		break;
@@ -1485,7 +1504,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
 				/* DEL LINK REQ during ADD LINK SEQ */
 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
 							qentry);
-				wake_up_interruptible(&lgr->llc_waiter);
+				wake_up(&lgr->llc_msg_waiter);
 			} else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
 						      qentry)) {
 				schedule_work(&lgr->llc_del_link_work);
@@ -1496,7 +1515,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
 				/* DEL LINK REQ during ADD LINK SEQ */
 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
 							qentry);
-				wake_up_interruptible(&lgr->llc_waiter);
+				wake_up(&lgr->llc_msg_waiter);
 			} else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
 						      qentry)) {
 				schedule_work(&lgr->llc_del_link_work);
@@ -1581,7 +1600,7 @@ static void smc_llc_rx_response(struct smc_link *link,
 	case SMC_LLC_DELETE_RKEY:
 		/* assign responses to the local flow, we requested them */
 		smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
-		wake_up_interruptible(&link->lgr->llc_waiter);
+		wake_up(&link->lgr->llc_msg_waiter);
 		return;
 	case SMC_LLC_CONFIRM_RKEY_CONT:
 		/* not used because max links is 3 */
@@ -1616,7 +1635,7 @@ static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
 	spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
 	list_add_tail(&qentry->list, &lgr->llc_event_q);
 	spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
-	schedule_work(&link->lgr->llc_event_work);
+	schedule_work(&lgr->llc_event_work);
 }
 
 /* copy received msg and add it to the event queue */
@@ -1677,7 +1696,8 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
 	INIT_LIST_HEAD(&lgr->llc_event_q);
 	spin_lock_init(&lgr->llc_event_q_lock);
 	spin_lock_init(&lgr->llc_flow_lock);
-	init_waitqueue_head(&lgr->llc_waiter);
+	init_waitqueue_head(&lgr->llc_flow_waiter);
+	init_waitqueue_head(&lgr->llc_msg_waiter);
 	mutex_init(&lgr->llc_conf_mutex);
 	lgr->llc_testlink_time = net->ipv4.sysctl_tcp_keepalive_time;
 }
@@ -1686,7 +1706,8 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
 void smc_llc_lgr_clear(struct smc_link_group *lgr)
 {
 	smc_llc_event_flush(lgr);
-	wake_up_interruptible_all(&lgr->llc_waiter);
+	wake_up_all(&lgr->llc_flow_waiter);
+	wake_up_all(&lgr->llc_msg_waiter);
 	cancel_work_sync(&lgr->llc_event_work);
 	cancel_work_sync(&lgr->llc_add_link_work);
 	cancel_work_sync(&lgr->llc_del_link_work);
-- 
2.17.1

[PATCH net 2/5] net/smc: fix work request handling

[Karsten Graul]

Wait for pending sends only when smc_switch_conns() found a link to move
the connections to. Do not wait during link freeing, this can lead to
permanent hang situations. And refuse to provide a new tx slot on an
unusable link.

Fixes: c6f02ebeea3a ("net/smc: switch connections to alternate link")
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
 net/smc/smc_llc.c |  8 ++++----
 net/smc/smc_wr.c  | 10 ++++++----
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index df164232574b..c1a038689c63 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -1241,8 +1241,8 @@ static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
 	smc_llc_send_message(lnk, &qentry->msg); /* response */
 
 	if (smc_link_downing(&lnk_del->state)) {
-		smc_switch_conns(lgr, lnk_del, false);
-		smc_wr_tx_wait_no_pending_sends(lnk_del);
+		if (smc_switch_conns(lgr, lnk_del, false))
+			smc_wr_tx_wait_no_pending_sends(lnk_del);
 	}
 	smcr_link_clear(lnk_del, true);
 
@@ -1316,8 +1316,8 @@ static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
 		goto out; /* asymmetric link already deleted */
 
 	if (smc_link_downing(&lnk_del->state)) {
-		smc_switch_conns(lgr, lnk_del, false);
-		smc_wr_tx_wait_no_pending_sends(lnk_del);
+		if (smc_switch_conns(lgr, lnk_del, false))
+			smc_wr_tx_wait_no_pending_sends(lnk_del);
 	}
 	if (!list_empty(&lgr->list)) {
 		/* qentry is either a request from peer (send it back to
diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c
index 7239ba9b99dc..1e23cdd41eb1 100644
--- a/net/smc/smc_wr.c
+++ b/net/smc/smc_wr.c
@@ -169,6 +169,8 @@ void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
 static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx)
 {
 	*idx = link->wr_tx_cnt;
+	if (!smc_link_usable(link))
+		return -ENOLINK;
 	for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) {
 		if (!test_and_set_bit(*idx, link->wr_tx_mask))
 			return 0;
@@ -560,15 +562,15 @@ void smc_wr_free_link(struct smc_link *lnk)
 {
 	struct ib_device *ibdev;
 
+	if (!lnk->smcibdev)
+		return;
+	ibdev = lnk->smcibdev->ibdev;
+
 	if (smc_wr_tx_wait_no_pending_sends(lnk))
 		memset(lnk->wr_tx_mask, 0,
 		       BITS_TO_LONGS(SMC_WR_BUF_CNT) *
 						sizeof(*lnk->wr_tx_mask));
 
-	if (!lnk->smcibdev)
-		return;
-	ibdev = lnk->smcibdev->ibdev;
-
 	if (lnk->wr_rx_dma_addr) {
 		ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
 				    SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
-- 
2.17.1

[PATCH net 3/5] net/smc: fix sleep bug in smc_pnet_find_roce_resource()

[Karsten Graul]

From: Ursula Braun <ubraun@linux.ibm.com>

Tests showed this BUG:
[572555.252867] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935
[572555.252876] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 131031, name: smcapp
[572555.252879] INFO: lockdep is turned off.
[572555.252883] CPU: 1 PID: 131031 Comm: smcapp Tainted: G           O      5.7.0-rc3uschi+ #356
[572555.252885] Hardware name: IBM 3906 M03 703 (LPAR)
[572555.252887] Call Trace:
[572555.252896]  [<00000000ac364554>] show_stack+0x94/0xe8
[572555.252901]  [<00000000aca1f400>] dump_stack+0xa0/0xe0
[572555.252906]  [<00000000ac3c8c10>] ___might_sleep+0x260/0x280
[572555.252910]  [<00000000acdc0c98>] __mutex_lock+0x48/0x940
[572555.252912]  [<00000000acdc15c2>] mutex_lock_nested+0x32/0x40
[572555.252975]  [<000003ff801762d0>] mlx5_lag_get_roce_netdev+0x30/0xc0 [mlx5_core]
[572555.252996]  [<000003ff801fb3aa>] mlx5_ib_get_netdev+0x3a/0xe0 [mlx5_ib]
[572555.253007]  [<000003ff80063848>] smc_pnet_find_roce_resource+0x1d8/0x310 [smc]
[572555.253011]  [<000003ff800602f0>] __smc_connect+0x1f0/0x3e0 [smc]
[572555.253015]  [<000003ff80060634>] smc_connect+0x154/0x190 [smc]
[572555.253022]  [<00000000acbed8d4>] __sys_connect+0x94/0xd0
[572555.253025]  [<00000000acbef620>] __s390x_sys_socketcall+0x170/0x360
[572555.253028]  [<00000000acdc6800>] system_call+0x298/0x2b8
[572555.253030] INFO: lockdep is turned off.

Function smc_pnet_find_rdma_dev() might be called from
smc_pnet_find_roce_resource(). It holds the smc_ib_devices list
spinlock while calling infiniband op get_netdev(). At least for mlx5
the get_netdev operation wants mutex serialization, which conflicts
with the smc_ib_devices spinlock.
This patch switches the smc_ib_devices spinlock into a mutex to
allow sleeping when calling get_netdev().

Fixes: a4cf0443c414 ("smc: introduce SMC as an IB-client")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
 net/smc/smc_core.c |  5 +++--
 net/smc/smc_ib.c   | 11 ++++++-----
 net/smc/smc_ib.h   |  3 ++-
 net/smc/smc_pnet.c | 21 +++++++++++----------
 4 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index d695ce71837e..8bf34d9f27e5 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -15,6 +15,7 @@
 #include <linux/workqueue.h>
 #include <linux/wait.h>
 #include <linux/reboot.h>
+#include <linux/mutex.h>
 #include <net/tcp.h>
 #include <net/sock.h>
 #include <rdma/ib_verbs.h>
@@ -1961,14 +1962,14 @@ static void smc_core_going_away(void)
 	struct smc_ib_device *smcibdev;
 	struct smcd_dev *smcd;
 
-	spin_lock(&smc_ib_devices.lock);
+	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);
 	}
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 
 	spin_lock(&smcd_dev_list.lock);
 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
index 562a52d01ad1..7637fdebbb78 100644
--- a/net/smc/smc_ib.c
+++ b/net/smc/smc_ib.c
@@ -16,6 +16,7 @@
 #include <linux/workqueue.h>
 #include <linux/scatterlist.h>
 #include <linux/wait.h>
+#include <linux/mutex.h>
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_cache.h>
 
@@ -33,7 +34,7 @@
 #define SMC_QP_RNR_RETRY			7 /* 7: infinite */
 
 struct smc_ib_devices smc_ib_devices = {	/* smc-registered ib devices */
-	.lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
+	.mutex = __MUTEX_INITIALIZER(smc_ib_devices.mutex),
 	.list = LIST_HEAD_INIT(smc_ib_devices.list),
 };
 
@@ -565,9 +566,9 @@ static int smc_ib_add_dev(struct ib_device *ibdev)
 	INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
 	atomic_set(&smcibdev->lnk_cnt, 0);
 	init_waitqueue_head(&smcibdev->lnks_deleted);
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_add_tail(&smcibdev->list, &smc_ib_devices.list);
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
 	INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
 			      smc_ib_global_event_handler);
@@ -602,9 +603,9 @@ static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
 {
 	struct smc_ib_device *smcibdev = client_data;
 
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	pr_warn_ratelimited("smc: removing ib device %s\n",
 			    smcibdev->ibdev->name);
 	smc_smcr_terminate_all(smcibdev);
diff --git a/net/smc/smc_ib.h b/net/smc/smc_ib.h
index e6a696ae15f3..ae6776e1e726 100644
--- a/net/smc/smc_ib.h
+++ b/net/smc/smc_ib.h
@@ -14,6 +14,7 @@
 
 #include <linux/interrupt.h>
 #include <linux/if_ether.h>
+#include <linux/mutex.h>
 #include <linux/wait.h>
 #include <rdma/ib_verbs.h>
 #include <net/smc.h>
@@ -25,7 +26,7 @@
 
 struct smc_ib_devices {			/* list of smc ib devices definition */
 	struct list_head	list;
-	spinlock_t		lock;	/* protects list of smc ib devices */
+	struct mutex		mutex;	/* protects list of smc ib devices */
 };
 
 extern struct smc_ib_devices	smc_ib_devices; /* list of smc ib devices */
diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
index 014d91b9778e..d4aac31d39f5 100644
--- a/net/smc/smc_pnet.c
+++ b/net/smc/smc_pnet.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/list.h>
 #include <linux/ctype.h>
+#include <linux/mutex.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>
 
@@ -129,7 +130,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
 		return rc;
 
 	/* remove ib devices */
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 		for (ibport = 0; ibport < SMC_MAX_PORTS; ibport++) {
 			if (ibdev->pnetid_by_user[ibport] &&
@@ -149,7 +150,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
 			}
 		}
 	}
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	/* remove smcd devices */
 	spin_lock(&smcd_dev_list.lock);
 	list_for_each_entry(smcd_dev, &smcd_dev_list.list, list) {
@@ -240,14 +241,14 @@ static bool smc_pnet_apply_ib(struct smc_ib_device *ib_dev, u8 ib_port,
 	u8 pnet_null[SMC_MAX_PNETID_LEN] = {0};
 	bool applied = false;
 
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	if (smc_pnet_match(ib_dev->pnetid[ib_port - 1], pnet_null)) {
 		memcpy(ib_dev->pnetid[ib_port - 1], pnet_name,
 		       SMC_MAX_PNETID_LEN);
 		ib_dev->pnetid_by_user[ib_port - 1] = true;
 		applied = true;
 	}
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	return applied;
 }
 
@@ -300,7 +301,7 @@ static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
 {
 	struct smc_ib_device *ibdev;
 
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 		if (!strncmp(ibdev->ibdev->name, ib_name,
 			     sizeof(ibdev->ibdev->name)) ||
@@ -311,7 +312,7 @@ static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
 	}
 	ibdev = NULL;
 out:
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	return ibdev;
 }
 
@@ -825,7 +826,7 @@ static void _smc_pnet_find_roce_by_pnetid(u8 *pnet_id,
 	int i;
 
 	ini->ib_dev = NULL;
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 		if (ibdev == known_dev)
 			continue;
@@ -844,7 +845,7 @@ static void _smc_pnet_find_roce_by_pnetid(u8 *pnet_id,
 		}
 	}
 out:
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 }
 
 /* find alternate roce device with same pnet_id and vlan_id */
@@ -863,7 +864,7 @@ static void smc_pnet_find_rdma_dev(struct net_device *netdev,
 {
 	struct smc_ib_device *ibdev;
 
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 		struct net_device *ndev;
 		int i;
@@ -888,7 +889,7 @@ static void smc_pnet_find_rdma_dev(struct net_device *netdev,
 			}
 		}
 	}
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 }
 
 /* Determine the corresponding IB device port based on the hardware PNETID.
-- 
2.17.1

[PATCH net 4/5] net/smc: switch smcd_dev_list spinlock to mutex

[Karsten Graul]

From: Ursula Braun <ubraun@linux.ibm.com>

The similar smc_ib_devices spinlock has been converted to a mutex.
Protecting the smcd_dev_list by a mutex is possible as well. This
patch converts the smcd_dev_list spinlock to a mutex.

Fixes: c6ba7c9ba43d ("net/smc: add base infrastructure for SMC-D and ISM")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
 net/smc/smc_core.c |  8 ++++----
 net/smc/smc_ism.c  | 11 ++++++-----
 net/smc/smc_ism.h  |  3 ++-
 net/smc/smc_pnet.c | 16 ++++++++--------
 4 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 8bf34d9f27e5..f69d205b3e11 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -1971,11 +1971,11 @@ static void smc_core_going_away(void)
 	}
 	mutex_unlock(&smc_ib_devices.mutex);
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
 		smcd->going_away = 1;
 	}
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 }
 
 /* Clean up all SMC link groups */
@@ -1987,10 +1987,10 @@ static void smc_lgrs_shutdown(void)
 
 	smc_smcr_terminate_all(NULL);
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(smcd, &smcd_dev_list.list, list)
 		smc_smcd_terminate_all(smcd);
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 }
 
 static int smc_core_reboot_event(struct notifier_block *this,
diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index 91f85fc09fb8..998c525de785 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/slab.h>
 #include <asm/page.h>
 
@@ -17,7 +18,7 @@
 
 struct smcd_dev_list smcd_dev_list = {
 	.list = LIST_HEAD_INIT(smcd_dev_list.list),
-	.lock = __SPIN_LOCK_UNLOCKED(smcd_dev_list.lock)
+	.mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex)
 };
 
 /* Test if an ISM communication is possible. */
@@ -317,9 +318,9 @@ EXPORT_SYMBOL_GPL(smcd_alloc_dev);
 
 int smcd_register_dev(struct smcd_dev *smcd)
 {
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_add_tail(&smcd->list, &smcd_dev_list.list);
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 
 	pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n",
 			    dev_name(&smcd->dev), smcd->pnetid,
@@ -333,9 +334,9 @@ void smcd_unregister_dev(struct smcd_dev *smcd)
 {
 	pr_warn_ratelimited("smc: removing smcd device %s\n",
 			    dev_name(&smcd->dev));
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_del_init(&smcd->list);
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 	smcd->going_away = 1;
 	smc_smcd_terminate_all(smcd);
 	flush_workqueue(smcd->event_wq);
diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h
index 4da946cbfa29..81cc4537efd3 100644
--- a/net/smc/smc_ism.h
+++ b/net/smc/smc_ism.h
@@ -10,12 +10,13 @@
 #define SMCD_ISM_H
 
 #include <linux/uio.h>
+#include <linux/mutex.h>
 
 #include "smc.h"
 
 struct smcd_dev_list {	/* List of SMCD devices */
 	struct list_head list;
-	spinlock_t lock;	/* Protects list of devices */
+	struct mutex mutex;	/* Protects list of devices */
 };
 
 extern struct smcd_dev_list	smcd_dev_list; /* list of smcd devices */
diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
index d4aac31d39f5..30e5fac7034e 100644
--- a/net/smc/smc_pnet.c
+++ b/net/smc/smc_pnet.c
@@ -152,7 +152,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
 	}
 	mutex_unlock(&smc_ib_devices.mutex);
 	/* remove smcd devices */
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(smcd_dev, &smcd_dev_list.list, list) {
 		if (smcd_dev->pnetid_by_user &&
 		    (!pnet_name ||
@@ -166,7 +166,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
 			rc = 0;
 		}
 	}
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 	return rc;
 }
 
@@ -259,13 +259,13 @@ static bool smc_pnet_apply_smcd(struct smcd_dev *smcd_dev, char *pnet_name)
 	u8 pnet_null[SMC_MAX_PNETID_LEN] = {0};
 	bool applied = false;
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	if (smc_pnet_match(smcd_dev->pnetid, pnet_null)) {
 		memcpy(smcd_dev->pnetid, pnet_name, SMC_MAX_PNETID_LEN);
 		smcd_dev->pnetid_by_user = true;
 		applied = true;
 	}
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 	return applied;
 }
 
@@ -321,7 +321,7 @@ static struct smcd_dev *smc_pnet_find_smcd(char *smcd_name)
 {
 	struct smcd_dev *smcd_dev;
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(smcd_dev, &smcd_dev_list.list, list) {
 		if (!strncmp(dev_name(&smcd_dev->dev), smcd_name,
 			     IB_DEVICE_NAME_MAX - 1))
@@ -329,7 +329,7 @@ static struct smcd_dev *smc_pnet_find_smcd(char *smcd_name)
 	}
 	smcd_dev = NULL;
 out:
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 	return smcd_dev;
 }
 
@@ -925,7 +925,7 @@ static void smc_pnet_find_ism_by_pnetid(struct net_device *ndev,
 	    smc_pnet_find_ndev_pnetid_by_table(ndev, ndev_pnetid))
 		return; /* pnetid could not be determined */
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(ismdev, &smcd_dev_list.list, list) {
 		if (smc_pnet_match(ismdev->pnetid, ndev_pnetid) &&
 		    !ismdev->going_away) {
@@ -933,7 +933,7 @@ static void smc_pnet_find_ism_by_pnetid(struct net_device *ndev,
 			break;
 		}
 	}
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 }
 
 /* PNET table analysis for a given sock:
-- 
2.17.1

[PATCH net 5/5] net/smc: tolerate future SMCD versions

[Karsten Graul]

From: Ursula Braun <ubraun@linux.ibm.com>

CLC proposal messages of future SMCD versions could be larger than SMCD
V1 CLC proposal messages.
To enable toleration in SMC V1 the receival of CLC proposal messages
is adapted:
* accept larger length values in CLC proposal
* check trailing eye catcher for incoming CLC proposal with V1 length only
* receive the whole CLC proposal even in cases it does not fit into the
  V1 buffer

Fixes: e7b7a64a8493d ("smc: support variable CLC proposal messages")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
 net/smc/smc_clc.c | 45 ++++++++++++++++++++++++++++++++-------------
 net/smc/smc_clc.h |  2 ++
 2 files changed, 34 insertions(+), 13 deletions(-)

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index d5627df24215..779f4142a11d 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -27,6 +27,7 @@
 
 #define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
 #define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
+#define SMC_CLC_RECV_BUF_LEN	100
 
 /* eye catcher "SMCR" EBCDIC for CLC messages */
 static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
@@ -36,7 +37,7 @@ static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};
 /* check if received message has a correct header length and contains valid
  * heading and trailing eyecatchers
  */
-static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
+static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
 {
 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
 	struct smc_clc_msg_accept_confirm *clc;
@@ -49,12 +50,9 @@ static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
 		return false;
 	switch (clcm->type) {
 	case SMC_CLC_PROPOSAL:
-		if (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
-		    clcm->path != SMC_TYPE_B)
-			return false;
 		pclc = (struct smc_clc_msg_proposal *)clcm;
 		pclc_prfx = smc_clc_proposal_get_prefix(pclc);
-		if (ntohs(pclc->hdr.length) !=
+		if (ntohs(pclc->hdr.length) <
 			sizeof(*pclc) + ntohs(pclc->iparea_offset) +
 			sizeof(*pclc_prfx) +
 			pclc_prfx->ipv6_prefixes_cnt *
@@ -86,7 +84,8 @@ static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
 	default:
 		return false;
 	}
-	if (memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
+	if (check_trl &&
+	    memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
 	    memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
 		return false;
 	return true;
@@ -276,7 +275,8 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	struct msghdr msg = {NULL, 0};
 	int reason_code = 0;
 	struct kvec vec = {buf, buflen};
-	int len, datlen;
+	int len, datlen, recvlen;
+	bool check_trl = true;
 	int krflags;
 
 	/* peek the first few bytes to determine length of data to receive
@@ -320,10 +320,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	}
 	datlen = ntohs(clcm->length);
 	if ((len < sizeof(struct smc_clc_msg_hdr)) ||
-	    (datlen > buflen) ||
-	    (clcm->version != SMC_CLC_V1) ||
-	    (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
-	     clcm->path != SMC_TYPE_B) ||
+	    (clcm->version < SMC_CLC_V1) ||
 	    ((clcm->type != SMC_CLC_DECLINE) &&
 	     (clcm->type != expected_type))) {
 		smc->sk.sk_err = EPROTO;
@@ -331,16 +328,38 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 		goto out;
 	}
 
+	if (clcm->type == SMC_CLC_PROPOSAL && clcm->path == SMC_TYPE_N)
+		reason_code = SMC_CLC_DECL_VERSMISMAT; /* just V2 offered */
+
 	/* receive the complete CLC message */
 	memset(&msg, 0, sizeof(struct msghdr));
-	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, datlen);
+	if (datlen > buflen) {
+		check_trl = false;
+		recvlen = buflen;
+	} else {
+		recvlen = datlen;
+	}
+	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
 	krflags = MSG_WAITALL;
 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
-	if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
+	if (len < recvlen || !smc_clc_msg_hdr_valid(clcm, check_trl)) {
 		smc->sk.sk_err = EPROTO;
 		reason_code = -EPROTO;
 		goto out;
 	}
+	datlen -= len;
+	while (datlen) {
+		u8 tmp[SMC_CLC_RECV_BUF_LEN];
+
+		vec.iov_base = &tmp;
+		vec.iov_len = SMC_CLC_RECV_BUF_LEN;
+		/* receive remaining proposal message */
+		recvlen = datlen > SMC_CLC_RECV_BUF_LEN ?
+						SMC_CLC_RECV_BUF_LEN : datlen;
+		iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
+		len = sock_recvmsg(smc->clcsock, &msg, krflags);
+		datlen -= len;
+	}
 	if (clcm->type == SMC_CLC_DECLINE) {
 		struct smc_clc_msg_decline *dclc;
 
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 465876701b75..76c2b150d040 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -25,6 +25,7 @@
 #define SMC_CLC_V1		0x1		/* SMC version                */
 #define SMC_TYPE_R		0		/* SMC-R only		      */
 #define SMC_TYPE_D		1		/* SMC-D only		      */
+#define SMC_TYPE_N		2		/* neither SMC-R nor SMC-D    */
 #define SMC_TYPE_B		3		/* SMC-R and SMC-D	      */
 #define CLC_WAIT_TIME		(6 * HZ)	/* max. wait time on clcsock  */
 #define CLC_WAIT_TIME_SHORT	HZ		/* short wait time on clcsock */
@@ -46,6 +47,7 @@
 #define SMC_CLC_DECL_ISMVLANERR	0x03090000  /* err to reg vlan id on ism dev  */
 #define SMC_CLC_DECL_NOACTLINK	0x030a0000  /* no active smc-r link in lgr    */
 #define SMC_CLC_DECL_NOSRVLINK	0x030b0000  /* SMC-R link from srv not found  */
+#define SMC_CLC_DECL_VERSMISMAT	0x030c0000  /* SMC version mismatch	      */
 #define SMC_CLC_DECL_SYNCERR	0x04000000  /* synchronization error          */
 #define SMC_CLC_DECL_PEERDECL	0x05000000  /* peer declined during handshake */
 #define SMC_CLC_DECL_INTERR	0x09990000  /* internal error		      */
-- 
2.17.1

Re: [PATCH net 0/5] net/smc: fixes 2020-07-08

[David Miller]

From: Karsten Graul <kgraul@linux.ibm.com>
Date: Wed,  8 Jul 2020 17:05:10 +0200

> Please apply the following patch series for smc to netdev's net tree.
> 
> The patches fix problems found during more testing of SMC
> functionality, resulting in hang conditions and unneeded link
> deactivations. The clc module was hardened to be prepared for
> possible future SMCD versions.

Series applied, thank you.