i40e: reopen client after reset

Allow the client interface to reopen existing clients if they were
closed. This allows clients to recover from reset, which is essential
for supporting VF RDMA. In one instance, the driver was not clearing the
open bit when the client was closed. Add the code to clear this bit so
that the state is accurate and the driver will not attempt to reopen
already-open clients. Remove the ref_cnt variable; it was just getting
in the way and was not being used consistently.

Change-ID: Ic71af4553b096963ac0c56a997f887c9a4ed162d
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_client.c

@@ -287,6 +287,7 @@ void i40e_notify_client_of_netdev_close(struct i40e_vsi *vsi, bool reset)
 			}
 			cdev->client->ops->close(&cdev->lan_info, cdev->client,
 						 reset);
+			clear_bit(__I40E_CLIENT_INSTANCE_OPENED, &cdev->state);
 			i40e_client_release_qvlist(&cdev->lan_info);
 		}
 	}
@@ -544,28 +545,27 @@ void i40e_client_subtask(struct i40e_pf *pf)
 			continue;
 
 		if (!existing) {
-			/* Also up the ref_cnt for no. of instances of this
-			 * client.
-			 */
-			atomic_inc(&client->ref_cnt);
 			dev_info(&pf->pdev->dev, "Added instance of Client %s to PF%d bus=0x%02x func=0x%02x\n",
 				 client->name, pf->hw.pf_id,
 				 pf->hw.bus.device, pf->hw.bus.func);
-			mutex_lock(&i40e_client_instance_mutex);
-			atomic_inc(&cdev->ref_cnt);
+		}
+
+		mutex_lock(&i40e_client_instance_mutex);
+		if (!test_bit(__I40E_CLIENT_INSTANCE_OPENED,
+			      &cdev->state)) {
+			/* Send an Open request to the client */
 			if (client->ops && client->ops->open)
 				ret = client->ops->open(&cdev->lan_info,
 							client);
-			atomic_dec(&cdev->ref_cnt);
-			if (ret < 0) {
-				mutex_unlock(&i40e_client_instance_mutex);
+			if (!ret) {
+				set_bit(__I40E_CLIENT_INSTANCE_OPENED,
+					&cdev->state);
+			} else {
+				/* remove client instance */
 				i40e_client_del_instance(pf, client);
-				atomic_dec(&client->ref_cnt);
-				continue;
 			}
-			set_bit(__I40E_CLIENT_INSTANCE_OPENED, &cdev->state);
-			mutex_unlock(&i40e_client_instance_mutex);
 		}
+		mutex_unlock(&i40e_client_instance_mutex);
 	}
 	mutex_unlock(&i40e_client_mutex);
 }
@@ -660,10 +660,6 @@ static int i40e_client_release(struct i40e_client *client)
 			continue;
 		pf = (struct i40e_pf *)cdev->lan_info.pf;
 		if (test_bit(__I40E_CLIENT_INSTANCE_OPENED, &cdev->state)) {
-			if (atomic_read(&cdev->ref_cnt) > 0) {
-				ret = I40E_ERR_NOT_READY;
-				goto out;
-			}
 			if (client->ops && client->ops->close)
 				client->ops->close(&cdev->lan_info, client,
 						   false);
@@ -676,11 +672,9 @@ static int i40e_client_release(struct i40e_client *client)
 		}
 		/* delete the client instance from the list */
 		list_move(&cdev->list, &cdevs_tmp);
-		atomic_dec(&client->ref_cnt);
 		dev_info(&pf->pdev->dev, "Deleted client instance of Client %s\n",
 			 client->name);
 	}
-out:
 	mutex_unlock(&i40e_client_instance_mutex);
 
 	/* free the client device and release its vsi */
@@ -1006,17 +1000,10 @@ int i40e_unregister_client(struct i40e_client *client)
 		ret = -ENODEV;
 		goto out;
 	}
-	if (atomic_read(&client->ref_cnt) == 0) {
-		clear_bit(__I40E_CLIENT_REGISTERED, &client->state);
-		list_del(&client->list);
-		pr_info("i40e: Unregistered client %s with return code %d\n",
-			client->name, ret);
-	} else {
-		ret = I40E_ERR_NOT_READY;
-		pr_err("i40e: Client %s failed unregister - client has open instances\n",
-		       client->name);
-	}
-
+	clear_bit(__I40E_CLIENT_REGISTERED, &client->state);
+	list_del(&client->list);
+	pr_info("i40e: Unregistered client %s with return code %d\n",
+		client->name, ret);
 out:
 	mutex_unlock(&i40e_client_mutex);
 	return ret;

drivers/net/ethernet/intel/i40e/i40e_client.h

@@ -203,8 +203,6 @@ struct i40e_client_instance {
 	struct i40e_info lan_info;
 	struct i40e_client *client;
 	unsigned long  state;
-	/* A count of all the in-progress calls to the client */
-	atomic_t ref_cnt;
 };
 
 struct i40e_client {