net/mlx5: Refactor devcom to return NULL on failure

Devcom device and component registration isn't always critical to the
functionality of the caller, hence the registration can fail and we can
continue working with an ERR_PTR value saved inside a variable.

In order to avoid that make sure all devcom failures return NULL.

Signed-off-by: Patrisious Haddad <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: PatrisiousHaddad

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

@@ -242,8 +242,8 @@ static int mlx5e_devcom_init_mpv(struct mlx5e_priv *priv, u64 *data)
 						      &attr,
 						      mlx5e_devcom_event_mpv,
 						      priv);
-	if (IS_ERR(priv->devcom))
-		return PTR_ERR(priv->devcom);
+	if (!priv->devcom)
+		return -EINVAL;
 
 	if (mlx5_core_is_mp_master(priv->mdev)) {
 		mlx5_devcom_send_event(priv->devcom, MPV_DEVCOM_MASTER_UP,
@@ -256,7 +256,7 @@ static int mlx5e_devcom_init_mpv(struct mlx5e_priv *priv, u64 *data)
 
 static void mlx5e_devcom_cleanup_mpv(struct mlx5e_priv *priv)
 {
-	if (IS_ERR_OR_NULL(priv->devcom))
+	if (!priv->devcom)
 		return;
 
 	if (mlx5_core_is_mp_master(priv->mdev)) {

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c

@@ -3129,7 +3129,7 @@ void mlx5_esw_offloads_devcom_init(struct mlx5_eswitch *esw,
 						     attr,
 						     mlx5_esw_offloads_devcom_event,
 						     esw);
-	if (IS_ERR(esw->devcom))
+	if (!esw->devcom)
 		return;
 
 	mlx5_devcom_send_event(esw->devcom,
@@ -3140,7 +3140,7 @@ void mlx5_esw_offloads_devcom_init(struct mlx5_eswitch *esw,
 
 void mlx5_esw_offloads_devcom_cleanup(struct mlx5_eswitch *esw)
 {
-	if (IS_ERR_OR_NULL(esw->devcom))
+	if (!esw->devcom)
 		return;
 
 	mlx5_devcom_send_event(esw->devcom,

drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c

@@ -1430,11 +1430,10 @@ static int mlx5_lag_register_hca_devcom_comp(struct mlx5_core_dev *dev)
 		mlx5_devcom_register_component(dev->priv.devc,
 					       MLX5_DEVCOM_HCA_PORTS,
 					       &attr, NULL, dev);
-	if (IS_ERR(dev->priv.hca_devcom_comp)) {
+	if (!dev->priv.hca_devcom_comp) {
 		mlx5_core_err(dev,
-			      "Failed to register devcom HCA component, err: %ld\n",
-			      PTR_ERR(dev->priv.hca_devcom_comp));
-		return PTR_ERR(dev->priv.hca_devcom_comp);
+			      "Failed to register devcom HCA component.");
+		return -EINVAL;
 	}
 
 	return 0;

drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c

@@ -1444,7 +1444,7 @@ static void mlx5_shared_clock_register(struct mlx5_core_dev *mdev, u64 key)
 	compd = mlx5_devcom_register_component(mdev->priv.devc,
 					       MLX5_DEVCOM_SHARED_CLOCK,
 					       &attr, NULL, mdev);
-	if (IS_ERR(compd))
+	if (!compd)
 		return;
 
 	mdev->clock_state->compdev = compd;

drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c

@@ -76,20 +76,18 @@ mlx5_devcom_dev_alloc(struct mlx5_core_dev *dev)
 struct mlx5_devcom_dev *
 mlx5_devcom_register_device(struct mlx5_core_dev *dev)
 {
-	struct mlx5_devcom_dev *devc;
+	struct mlx5_devcom_dev *devc = NULL;
 
 	mutex_lock(&dev_list_lock);
 
 	if (devcom_dev_exists(dev)) {
-		devc = ERR_PTR(-EEXIST);
+		mlx5_core_err(dev, "devcom device already exists");
 		goto out;
 	}
 
 	devc = mlx5_devcom_dev_alloc(dev);
-	if (!devc) {
-		devc = ERR_PTR(-ENOMEM);
+	if (!devc)
 		goto out;
-	}
 
 	list_add_tail(&devc->list, &devcom_dev_list);
 out:
@@ -110,8 +108,10 @@ mlx5_devcom_dev_release(struct kref *ref)
 
 void mlx5_devcom_unregister_device(struct mlx5_devcom_dev *devc)
 {
-	if (!IS_ERR_OR_NULL(devc))
-		kref_put(&devc->ref, mlx5_devcom_dev_release);
+	if (!devc)
+		return;
+
+	kref_put(&devc->ref, mlx5_devcom_dev_release);
 }
 
 static struct mlx5_devcom_comp *
@@ -122,7 +122,7 @@ mlx5_devcom_comp_alloc(u64 id, const struct mlx5_devcom_match_attr *attr,
 
 	comp = kzalloc(sizeof(*comp), GFP_KERNEL);
 	if (!comp)
-		return ERR_PTR(-ENOMEM);
+		return NULL;
 
 	comp->id = id;
 	comp->key.key = attr->key;
@@ -160,7 +160,7 @@ devcom_alloc_comp_dev(struct mlx5_devcom_dev *devc,
 
 	devcom = kzalloc(sizeof(*devcom), GFP_KERNEL);
 	if (!devcom)
-		return ERR_PTR(-ENOMEM);
+		return NULL;
 
 	kref_get(&devc->ref);
 	devcom->devc = devc;
@@ -240,31 +240,28 @@ mlx5_devcom_register_component(struct mlx5_devcom_dev *devc,
 			       mlx5_devcom_event_handler_t handler,
 			       void *data)
 {
-	struct mlx5_devcom_comp_dev *devcom;
+	struct mlx5_devcom_comp_dev *devcom = NULL;
 	struct mlx5_devcom_comp *comp;
 
-	if (IS_ERR_OR_NULL(devc))
-		return ERR_PTR(-EINVAL);
+	if (!devc)
+		return NULL;
 
 	mutex_lock(&comp_list_lock);
 	comp = devcom_component_get(devc, id, attr, handler);
-	if (IS_ERR(comp)) {
-		devcom = ERR_PTR(-EINVAL);
+	if (IS_ERR(comp))
 		goto out_unlock;
-	}
 
 	if (!comp) {
 		comp = mlx5_devcom_comp_alloc(id, attr, handler);
-		if (IS_ERR(comp)) {
-			devcom = ERR_CAST(comp);
+		if (!comp)
 			goto out_unlock;
-		}
+
 		list_add_tail(&comp->comp_list, &devcom_comp_list);
 	}
 	mutex_unlock(&comp_list_lock);
 
 	devcom = devcom_alloc_comp_dev(devc, comp, data);
-	if (IS_ERR(devcom))
+	if (!devcom)
 		kref_put(&comp->ref, mlx5_devcom_comp_release);
 
 	return devcom;
@@ -276,8 +273,10 @@ mlx5_devcom_register_component(struct mlx5_devcom_dev *devc,
 
 void mlx5_devcom_unregister_component(struct mlx5_devcom_comp_dev *devcom)
 {
-	if (!IS_ERR_OR_NULL(devcom))
-		devcom_free_comp_dev(devcom);
+	if (!devcom)
+		return;
+
+	devcom_free_comp_dev(devcom);
 }
 
 int mlx5_devcom_comp_get_size(struct mlx5_devcom_comp_dev *devcom)
@@ -296,7 +295,7 @@ int mlx5_devcom_send_event(struct mlx5_devcom_comp_dev *devcom,
 	int err = 0;
 	void *data;
 
-	if (IS_ERR_OR_NULL(devcom))
+	if (!devcom)
 		return -ENODEV;
 
 	comp = devcom->comp;
@@ -338,7 +337,7 @@ void mlx5_devcom_comp_set_ready(struct mlx5_devcom_comp_dev *devcom, bool ready)
 
 bool mlx5_devcom_comp_is_ready(struct mlx5_devcom_comp_dev *devcom)
 {
-	if (IS_ERR_OR_NULL(devcom))
+	if (!devcom)
 		return false;
 
 	return READ_ONCE(devcom->comp->ready);
@@ -348,7 +347,7 @@ bool mlx5_devcom_for_each_peer_begin(struct mlx5_devcom_comp_dev *devcom)
 {
 	struct mlx5_devcom_comp *comp;
 
-	if (IS_ERR_OR_NULL(devcom))
+	if (!devcom)
 		return false;
 
 	comp = devcom->comp;
@@ -421,21 +420,21 @@ void *mlx5_devcom_get_next_peer_data_rcu(struct mlx5_devcom_comp_dev *devcom,
 
 void mlx5_devcom_comp_lock(struct mlx5_devcom_comp_dev *devcom)
 {
-	if (IS_ERR_OR_NULL(devcom))
+	if (!devcom)
 		return;
 	down_write(&devcom->comp->sem);
 }
 
 void mlx5_devcom_comp_unlock(struct mlx5_devcom_comp_dev *devcom)
 {
-	if (IS_ERR_OR_NULL(devcom))
+	if (!devcom)
 		return;
 	up_write(&devcom->comp->sem);
 }
 
 int mlx5_devcom_comp_trylock(struct mlx5_devcom_comp_dev *devcom)
 {
-	if (IS_ERR_OR_NULL(devcom))
+	if (!devcom)
 		return 0;
 	return down_write_trylock(&devcom->comp->sem);
 }

drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c

@@ -221,8 +221,8 @@ static int sd_register(struct mlx5_core_dev *dev)
 	attr.net = mlx5_core_net(dev);
 	devcom = mlx5_devcom_register_component(dev->priv.devc, MLX5_DEVCOM_SD_GROUP,
 						&attr, NULL, dev);
-	if (IS_ERR(devcom))
-		return PTR_ERR(devcom);
+	if (!devcom)
+		return -EINVAL;
 
 	sd->devcom = devcom;
 

drivers/net/ethernet/mellanox/mlx5/core/main.c

@@ -978,9 +978,8 @@ static int mlx5_init_once(struct mlx5_core_dev *dev)
 	int err;
 
 	dev->priv.devc = mlx5_devcom_register_device(dev);
-	if (IS_ERR(dev->priv.devc))
-		mlx5_core_warn(dev, "failed to register devcom device %pe\n",
-			       dev->priv.devc);
+	if (!dev->priv.devc)
+		mlx5_core_warn(dev, "failed to register devcom device\n");
 
 	err = mlx5_query_board_id(dev);
 	if (err) {