i40iw: Extend port reuse support for listeners

If two listeners are created with different IP's but
same port, the second rdma_listen fails due to a
duplicate port entry being added from the CQP add
APBVT OP. commit f16dc0aa5ea2 ("i40iw: Add support
for port reuse on active side connections") does not
account for listener side port reuse.

Check for duplicate port before invoking the CQP command
to add APBVT entry and delete the entry only if the port
is not in use. Additionally, consolidate all port-reuse
logic into i40iw_manage_apbvt.

Fixes: f16dc0aa5ea2 ("i40iw: Add support for port reuse on active side connections")
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/i40iw/i40iw_cm.c

@@ -1519,18 +1519,13 @@ static void i40iw_add_hte_node(struct i40iw_cm_core *cm_core,
 
 /**
  * i40iw_find_port - find port that matches reference port
- * @port: port number
+ * @hte: ptr to accelerated or non-accelerated list
  * @accelerated_list: flag for accelerated vs non-accelerated list
  */
-static bool i40iw_find_port(struct i40iw_cm_core *cm_core, u16 port,
-			    bool accelerated_list)
+static bool i40iw_find_port(struct list_head *hte, u16 port)
 {
-	struct list_head *hte;
 	struct i40iw_cm_node *cm_node;
 
-	hte = accelerated_list ?
-	      &cm_core->accelerated_list : &cm_core->non_accelerated_list;
-
 	list_for_each_entry(cm_node, hte, list) {
 		if (cm_node->loc_port == port)
 			return true;
@@ -1540,35 +1535,32 @@ static bool i40iw_find_port(struct i40iw_cm_core *cm_core, u16 port,
 
 /**
  * i40iw_port_in_use - determine if port is in use
+ * @cm_core: cm's core
  * @port: port number
- * @active_side: flag for listener side vs active side
  */
-static bool i40iw_port_in_use(struct i40iw_cm_core *cm_core, u16 port, bool active_side)
+bool i40iw_port_in_use(struct i40iw_cm_core *cm_core, u16 port)
 {
 	struct i40iw_cm_listener *listen_node;
 	unsigned long flags;
-	bool ret = false;
 
-	if (active_side) {
-		spin_lock_irqsave(&cm_core->ht_lock, flags);
-		ret = i40iw_find_port(cm_core, port, true);
-		if (!ret)
-			ret = i40iw_find_port(cm_core, port, false);
-		if (!ret)
-			clear_bit(port, cm_core->active_side_ports);
+	spin_lock_irqsave(&cm_core->ht_lock, flags);
+	if (i40iw_find_port(&cm_core->accelerated_list, port) ||
+	    i40iw_find_port(&cm_core->non_accelerated_list, port)) {
 		spin_unlock_irqrestore(&cm_core->ht_lock, flags);
-	} else {
-		spin_lock_irqsave(&cm_core->listen_list_lock, flags);
-		list_for_each_entry(listen_node, &cm_core->listen_nodes, list) {
-			if (listen_node->loc_port == port) {
-				ret = true;
-				break;
-			}
+		return true;
+	}
+	spin_unlock_irqrestore(&cm_core->ht_lock, flags);
+
+	spin_lock_irqsave(&cm_core->listen_list_lock, flags);
+	list_for_each_entry(listen_node, &cm_core->listen_nodes, list) {
+		if (listen_node->loc_port == port) {
+			spin_unlock_irqrestore(&cm_core->listen_list_lock, flags);
+			return true;
 		}
-		spin_unlock_irqrestore(&cm_core->listen_list_lock, flags);
 	}
+	spin_unlock_irqrestore(&cm_core->listen_list_lock, flags);
 
-	return ret;
+	return false;
 }
 
 /**
@@ -1917,7 +1909,7 @@ static int i40iw_dec_refcnt_listen(struct i40iw_cm_core *cm_core,
 		spin_unlock_irqrestore(&cm_core->listen_list_lock, flags);
 
 		if (listener->iwdev) {
-			if (apbvt_del && !i40iw_port_in_use(cm_core, listener->loc_port, false))
+			if (apbvt_del)
 				i40iw_manage_apbvt(listener->iwdev,
 						   listener->loc_port,
 						   I40IW_MANAGE_APBVT_DEL);
@@ -2298,7 +2290,7 @@ static void i40iw_rem_ref_cm_node(struct i40iw_cm_node *cm_node)
 	if (cm_node->listener) {
 		i40iw_dec_refcnt_listen(cm_core, cm_node->listener, 0, true);
 	} else {
-		if (!i40iw_port_in_use(cm_core, cm_node->loc_port, true) && cm_node->apbvt_set) {
+		if (cm_node->apbvt_set) {
 			i40iw_manage_apbvt(cm_node->iwdev,
 					   cm_node->loc_port,
 					   I40IW_MANAGE_APBVT_DEL);
@@ -3244,6 +3236,7 @@ void i40iw_setup_cm_core(struct i40iw_device *iwdev)
 
 	spin_lock_init(&cm_core->ht_lock);
 	spin_lock_init(&cm_core->listen_list_lock);
+	spin_lock_init(&cm_core->apbvt_lock);
 
 	cm_core->event_wq = alloc_ordered_workqueue("iwewq",
 						    WQ_MEM_RECLAIM);
@@ -3811,7 +3804,6 @@ int i40iw_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *conn_param)
 	struct sockaddr_in6 *laddr6;
 	struct sockaddr_in6 *raddr6;
 	int ret = 0;
-	unsigned long flags;
 
 	ibqp = i40iw_get_qp(cm_id->device, conn_param->qpn);
 	if (!ibqp)
@@ -3882,15 +3874,10 @@ int i40iw_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *conn_param)
 		cm_node->qhash_set = true;
 	}
 
-	spin_lock_irqsave(&iwdev->cm_core.ht_lock, flags);
-	if (!test_and_set_bit(cm_info.loc_port, iwdev->cm_core.active_side_ports)) {
-		spin_unlock_irqrestore(&iwdev->cm_core.ht_lock, flags);
-		if (i40iw_manage_apbvt(iwdev, cm_info.loc_port, I40IW_MANAGE_APBVT_ADD)) {
-			ret =  -EINVAL;
-			goto err;
-		}
-	} else {
-		spin_unlock_irqrestore(&iwdev->cm_core.ht_lock, flags);
+	if (i40iw_manage_apbvt(iwdev, cm_info.loc_port,
+			       I40IW_MANAGE_APBVT_ADD)) {
+		ret =  -EINVAL;
+		goto err;
 	}
 
 	cm_node->apbvt_set = true;

drivers/infiniband/hw/i40iw/i40iw_cm.h

@@ -413,8 +413,9 @@ struct i40iw_cm_core {
 
 	spinlock_t ht_lock; /* manage hash table */
 	spinlock_t listen_list_lock; /* listen list */
+	spinlock_t apbvt_lock; /*manage apbvt entries*/
 
-	unsigned long active_side_ports[BITS_TO_LONGS(MAX_PORTS)];
+	unsigned long ports_in_use[BITS_TO_LONGS(MAX_PORTS)];
 
 	u64	stats_nodes_created;
 	u64	stats_nodes_destroyed;
@@ -457,4 +458,5 @@ void i40iw_if_notify(struct i40iw_device *iwdev, struct net_device *netdev,
 void i40iw_cm_teardown_connections(struct i40iw_device *iwdev, u32 *ipaddr,
 				   struct i40iw_cm_info *nfo,
 				   bool disconnect_all);
+bool i40iw_port_in_use(struct i40iw_cm_core *cm_core, u16 port);
 #endif /* I40IW_CM_H */

drivers/infiniband/hw/i40iw/i40iw_hw.c

@@ -443,13 +443,37 @@ void i40iw_process_aeq(struct i40iw_device *iwdev)
 int i40iw_manage_apbvt(struct i40iw_device *iwdev, u16 accel_local_port, bool add_port)
 {
 	struct i40iw_apbvt_info *info;
-	enum i40iw_status_code status;
 	struct i40iw_cqp_request *cqp_request;
 	struct cqp_commands_info *cqp_info;
+	unsigned long flags;
+	struct i40iw_cm_core *cm_core = &iwdev->cm_core;
+	enum i40iw_status_code status = 0;
+	bool in_use;
+
+	/* apbvt_lock is held across CQP delete APBVT OP (non-waiting) to
+	 * protect against race where add APBVT CQP can race ahead of the delete
+	 * APBVT for same port.
+	 */
+	spin_lock_irqsave(&cm_core->apbvt_lock, flags);
+
+	if (!add_port) {
+		in_use = i40iw_port_in_use(cm_core, accel_local_port);
+		if (in_use)
+			goto exit;
+		clear_bit(accel_local_port, cm_core->ports_in_use);
+	} else {
+		in_use = test_and_set_bit(accel_local_port,
+					  cm_core->ports_in_use);
+		spin_unlock_irqrestore(&cm_core->apbvt_lock, flags);
+		if (in_use)
+			return 0;
+	}
 
 	cqp_request = i40iw_get_cqp_request(&iwdev->cqp, add_port);
-	if (!cqp_request)
-		return -ENOMEM;
+	if (!cqp_request) {
+		status = -ENOMEM;
+		goto exit;
+	}
 
 	cqp_info = &cqp_request->info;
 	info = &cqp_info->in.u.manage_apbvt_entry.info;
@@ -465,6 +489,10 @@ int i40iw_manage_apbvt(struct i40iw_device *iwdev, u16 accel_local_port, bool ad
 	status = i40iw_handle_cqp_op(iwdev, cqp_request);
 	if (status)
 		i40iw_pr_err("CQP-OP Manage APBVT entry fail");
+exit:
+	if (!add_port)
+		spin_unlock_irqrestore(&cm_core->apbvt_lock, flags);
+
 	return status;
 }