IB/mad: Change atomics to refcount API

The refcount API provides better safety than atomics API.  Therefore,
change atomic functions to refcount functions.

Link: https://lore.kernel.org/r/20200621104738.54850-4-leon@kernel.orgSigned-off-by: Shay Drory <shayd@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/mad.c

@@ -402,7 +402,7 @@ struct ib_mad_agent *ib_register_mad_agent(struct ib_device *device,
 	INIT_DELAYED_WORK(&mad_agent_priv->timed_work, timeout_sends);
 	INIT_LIST_HEAD(&mad_agent_priv->local_list);
 	INIT_WORK(&mad_agent_priv->local_work, local_completions);
-	atomic_set(&mad_agent_priv->refcount, 1);
+	refcount_set(&mad_agent_priv->refcount, 1);
 	init_completion(&mad_agent_priv->comp);
 
 	ret2 = ib_mad_agent_security_setup(&mad_agent_priv->agent, qp_type);
@@ -484,7 +484,7 @@ EXPORT_SYMBOL(ib_register_mad_agent);
 
 static inline void deref_mad_agent(struct ib_mad_agent_private *mad_agent_priv)
 {
-	if (atomic_dec_and_test(&mad_agent_priv->refcount))
+	if (refcount_dec_and_test(&mad_agent_priv->refcount))
 		complete(&mad_agent_priv->comp);
 }
 
@@ -718,7 +718,7 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
 			 * Reference MAD agent until receive
 			 * side of local completion handled
 			 */
-			atomic_inc(&mad_agent_priv->refcount);
+			refcount_inc(&mad_agent_priv->refcount);
 		} else
 			kfree(mad_priv);
 		break;
@@ -758,7 +758,7 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
 		local->return_wc_byte_len = mad_size;
 	}
 	/* Reference MAD agent until send side of local completion handled */
-	atomic_inc(&mad_agent_priv->refcount);
+	refcount_inc(&mad_agent_priv->refcount);
 	/* Queue local completion to local list */
 	spin_lock_irqsave(&mad_agent_priv->lock, flags);
 	list_add_tail(&local->completion_list, &mad_agent_priv->local_list);
@@ -916,7 +916,7 @@ struct ib_mad_send_buf * ib_create_send_mad(struct ib_mad_agent *mad_agent,
 	}
 
 	mad_send_wr->send_buf.mad_agent = mad_agent;
-	atomic_inc(&mad_agent_priv->refcount);
+	refcount_inc(&mad_agent_priv->refcount);
 	return &mad_send_wr->send_buf;
 }
 EXPORT_SYMBOL(ib_create_send_mad);
@@ -1131,7 +1131,7 @@ int ib_post_send_mad(struct ib_mad_send_buf *send_buf,
 		mad_send_wr->status = IB_WC_SUCCESS;
 
 		/* Reference MAD agent until send completes */
-		atomic_inc(&mad_agent_priv->refcount);
+		refcount_inc(&mad_agent_priv->refcount);
 		spin_lock_irqsave(&mad_agent_priv->lock, flags);
 		list_add_tail(&mad_send_wr->agent_list,
 			      &mad_agent_priv->send_list);
@@ -1554,7 +1554,7 @@ find_mad_agent(struct ib_mad_port_private *port_priv,
 		hi_tid = be64_to_cpu(mad_hdr->tid) >> 32;
 		rcu_read_lock();
 		mad_agent = xa_load(&ib_mad_clients, hi_tid);
-		if (mad_agent && !atomic_inc_not_zero(&mad_agent->refcount))
+		if (mad_agent && !refcount_inc_not_zero(&mad_agent->refcount))
 			mad_agent = NULL;
 		rcu_read_unlock();
 	} else {
@@ -1606,7 +1606,7 @@ find_mad_agent(struct ib_mad_port_private *port_priv,
 			}
 		}
 		if (mad_agent)
-			atomic_inc(&mad_agent->refcount);
+			refcount_inc(&mad_agent->refcount);
 out:
 		spin_unlock_irqrestore(&port_priv->reg_lock, flags);
 	}

drivers/infiniband/core/mad_priv.h

@@ -103,7 +103,7 @@ struct ib_mad_agent_private {
 	struct work_struct local_work;
 	struct list_head rmpp_list;
 
-	atomic_t refcount;
+	refcount_t refcount;
 	union {
 		struct completion comp;
 		struct rcu_head rcu;

drivers/infiniband/core/mad_rmpp.c

@@ -52,7 +52,7 @@ struct mad_rmpp_recv {
 	struct completion comp;
 	enum rmpp_state state;
 	spinlock_t lock;
-	atomic_t refcount;
+	refcount_t refcount;
 
 	struct ib_ah *ah;
 	struct ib_mad_recv_wc *rmpp_wc;
@@ -73,7 +73,7 @@ struct mad_rmpp_recv {
 
 static inline void deref_rmpp_recv(struct mad_rmpp_recv *rmpp_recv)
 {
-	if (atomic_dec_and_test(&rmpp_recv->refcount))
+	if (refcount_dec_and_test(&rmpp_recv->refcount))
 		complete(&rmpp_recv->comp);
 }
 
@@ -305,7 +305,7 @@ create_rmpp_recv(struct ib_mad_agent_private *agent,
 	INIT_DELAYED_WORK(&rmpp_recv->cleanup_work, recv_cleanup_handler);
 	spin_lock_init(&rmpp_recv->lock);
 	rmpp_recv->state = RMPP_STATE_ACTIVE;
-	atomic_set(&rmpp_recv->refcount, 1);
+	refcount_set(&rmpp_recv->refcount, 1);
 
 	rmpp_recv->rmpp_wc = mad_recv_wc;
 	rmpp_recv->cur_seg_buf = &mad_recv_wc->recv_buf;
@@ -357,7 +357,7 @@ acquire_rmpp_recv(struct ib_mad_agent_private *agent,
 	spin_lock_irqsave(&agent->lock, flags);
 	rmpp_recv = find_rmpp_recv(agent, mad_recv_wc);
 	if (rmpp_recv)
-		atomic_inc(&rmpp_recv->refcount);
+		refcount_inc(&rmpp_recv->refcount);
 	spin_unlock_irqrestore(&agent->lock, flags);
 	return rmpp_recv;
 }
@@ -553,7 +553,7 @@ start_rmpp(struct ib_mad_agent_private *agent,
 		destroy_rmpp_recv(rmpp_recv);
 		return continue_rmpp(agent, mad_recv_wc);
 	}
-	atomic_inc(&rmpp_recv->refcount);
+	refcount_inc(&rmpp_recv->refcount);
 
 	if (get_last_flag(&mad_recv_wc->recv_buf)) {
 		rmpp_recv->state = RMPP_STATE_COMPLETE;