Merge branch 'ethtool-ringparam-upper-bound'

Tariq Toukan says:

====================
ethtool ringparam upper bound

This patchset by Jenny adds sanity checks in ethtool ringparam
operation for input upper bounds, similarly to what's done in
ethtool_set_channels.

The checks are added in patch 1, using a call to get_ringparam
prior to calling set_ringparam NDO.

Patch 2 changes the function's behavior in mlx4_en, so that
it returns an error for out-of-range input, instead of rounding
it to closest valid, similar to mlx5e.

Patch 3 removes the upper bound checks in mlx5e_ethtool_set_ringparam
as it becomes redundant.

Series generated against net-next commit:
f66faae2f80a Merge branch 'ipv6-ipv4-nexthop-align'
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_ethtool.c

@@ -1094,12 +1094,21 @@ static int mlx4_en_set_ringparam(struct net_device *dev,
 	if (param->rx_jumbo_pending || param->rx_mini_pending)
 		return -EINVAL;
 
+	if (param->rx_pending < MLX4_EN_MIN_RX_SIZE) {
+		en_warn(priv, "%s: rx_pending (%d) < min (%d)\n",
+			__func__, param->rx_pending,
+			MLX4_EN_MIN_RX_SIZE);
+		return -EINVAL;
+	}
+	if (param->tx_pending < MLX4_EN_MIN_TX_SIZE) {
+		en_warn(priv, "%s: tx_pending (%d) < min (%lu)\n",
+			__func__, param->tx_pending,
+			MLX4_EN_MIN_TX_SIZE);
+		return -EINVAL;
+	}
+
 	rx_size = roundup_pow_of_two(param->rx_pending);
-	rx_size = max_t(u32, rx_size, MLX4_EN_MIN_RX_SIZE);
-	rx_size = min_t(u32, rx_size, MLX4_EN_MAX_RX_SIZE);
 	tx_size = roundup_pow_of_two(param->tx_pending);
-	tx_size = max_t(u32, tx_size, MLX4_EN_MIN_TX_SIZE);
-	tx_size = min_t(u32, tx_size, MLX4_EN_MAX_TX_SIZE);
 
 	if (rx_size == (priv->port_up ? priv->rx_ring[0]->actual_size :
 					priv->rx_ring[0]->size) &&

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

@@ -296,7 +296,6 @@ int mlx5e_ethtool_set_ringparam(struct mlx5e_priv *priv,
 	struct mlx5e_channels new_channels = {};
 	u32 rx_pending_wqes;
 	u32 min_rq_size;
-	u32 max_rq_size;
 	u8 log_rq_size;
 	u8 log_sq_size;
 	u32 num_mtts;
@@ -315,8 +314,6 @@ int mlx5e_ethtool_set_ringparam(struct mlx5e_priv *priv,
 
 	min_rq_size = mlx5e_rx_wqes_to_packets(priv, rq_wq_type,
 					       1 << mlx5_min_log_rq_size(rq_wq_type));
-	max_rq_size = mlx5e_rx_wqes_to_packets(priv, rq_wq_type,
-					       1 << mlx5_max_log_rq_size(rq_wq_type));
 	rx_pending_wqes = mlx5e_packets_to_rx_wqes(priv, rq_wq_type,
 						   param->rx_pending);
 
@@ -326,12 +323,6 @@ int mlx5e_ethtool_set_ringparam(struct mlx5e_priv *priv,
 			    min_rq_size);
 		return -EINVAL;
 	}
-	if (param->rx_pending > max_rq_size) {
-		netdev_info(priv->netdev, "%s: rx_pending (%d) > max (%d)\n",
-			    __func__, param->rx_pending,
-			    max_rq_size);
-		return -EINVAL;
-	}
 
 	num_mtts = MLX5E_REQUIRED_MTTS(rx_pending_wqes);
 	if (priv->channels.params.rq_wq_type == MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ &&
@@ -347,12 +338,6 @@ int mlx5e_ethtool_set_ringparam(struct mlx5e_priv *priv,
 			    1 << MLX5E_PARAMS_MINIMUM_LOG_SQ_SIZE);
 		return -EINVAL;
 	}
-	if (param->tx_pending > (1 << MLX5E_PARAMS_MAXIMUM_LOG_SQ_SIZE)) {
-		netdev_info(priv->netdev, "%s: tx_pending (%d) > max (%d)\n",
-			    __func__, param->tx_pending,
-			    1 << MLX5E_PARAMS_MAXIMUM_LOG_SQ_SIZE);
-		return -EINVAL;
-	}
 
 	log_rq_size = order_base_2(rx_pending_wqes);
 	log_sq_size = order_base_2(param->tx_pending);

net/core/ethtool.c

@@ -1693,14 +1693,23 @@ static int ethtool_get_ringparam(struct net_device *dev, void __user *useraddr)
 
 static int ethtool_set_ringparam(struct net_device *dev, void __user *useraddr)
 {
-	struct ethtool_ringparam ringparam;
+	struct ethtool_ringparam ringparam, max = { .cmd = ETHTOOL_GRINGPARAM };
 
-	if (!dev->ethtool_ops->set_ringparam)
+	if (!dev->ethtool_ops->set_ringparam || !dev->ethtool_ops->get_ringparam)
 		return -EOPNOTSUPP;
 
 	if (copy_from_user(&ringparam, useraddr, sizeof(ringparam)))
 		return -EFAULT;
 
+	dev->ethtool_ops->get_ringparam(dev, &max);
+
+	/* ensure new ring parameters are within the maximums */
+	if (ringparam.rx_pending > max.rx_max_pending ||
+	    ringparam.rx_mini_pending > max.rx_mini_max_pending ||
+	    ringparam.rx_jumbo_pending > max.rx_jumbo_max_pending ||
+	    ringparam.tx_pending > max.tx_max_pending)
+		return -EINVAL;
+
 	return dev->ethtool_ops->set_ringparam(dev, &ringparam);
 }