[PATCH 5.3 03/95] net/mlx4_en: Fix wrong limitation for number of TX rings

From: Greg Kroah-Hartman
Date: Wed Nov 27 2019 - 16:09:30 EST


From: Tariq Toukan <tariqt@xxxxxxxxxxxx>

[ Upstream commit 2744bf42680f64ebf2ee8a00354897857c073331 ]

XDP_TX rings should not be limited by max_num_tx_rings_p_up.
To make sure total number of TX rings never exceed MAX_TX_RINGS,
add similar check in mlx4_en_alloc_tx_queue_per_tc(), where
a new value is assigned for num_up.

Fixes: 7e1dc5e926d5 ("net/mlx4_en: Limit the number of TX rings")
Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/mellanox/mlx4/en_ethtool.c | 8 ++++----
drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 9 +++++++++
2 files changed, 13 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -1812,6 +1812,7 @@ static int mlx4_en_set_channels(struct n
struct mlx4_en_dev *mdev = priv->mdev;
struct mlx4_en_port_profile new_prof;
struct mlx4_en_priv *tmp;
+ int total_tx_count;
int port_up = 0;
int xdp_count;
int err = 0;
@@ -1826,13 +1827,12 @@ static int mlx4_en_set_channels(struct n

mutex_lock(&mdev->state_lock);
xdp_count = priv->tx_ring_num[TX_XDP] ? channel->rx_count : 0;
- if (channel->tx_count * priv->prof->num_up + xdp_count >
- priv->mdev->profile.max_num_tx_rings_p_up * priv->prof->num_up) {
+ total_tx_count = channel->tx_count * priv->prof->num_up + xdp_count;
+ if (total_tx_count > MAX_TX_RINGS) {
err = -EINVAL;
en_err(priv,
"Total number of TX and XDP rings (%d) exceeds the maximum supported (%d)\n",
- channel->tx_count * priv->prof->num_up + xdp_count,
- MAX_TX_RINGS);
+ total_tx_count, MAX_TX_RINGS);
goto out;
}

--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -91,6 +91,7 @@ int mlx4_en_alloc_tx_queue_per_tc(struct
struct mlx4_en_dev *mdev = priv->mdev;
struct mlx4_en_port_profile new_prof;
struct mlx4_en_priv *tmp;
+ int total_count;
int port_up = 0;
int err = 0;

@@ -104,6 +105,14 @@ int mlx4_en_alloc_tx_queue_per_tc(struct
MLX4_EN_NUM_UP_HIGH;
new_prof.tx_ring_num[TX] = new_prof.num_tx_rings_p_up *
new_prof.num_up;
+ total_count = new_prof.tx_ring_num[TX] + new_prof.tx_ring_num[TX_XDP];
+ if (total_count > MAX_TX_RINGS) {
+ err = -EINVAL;
+ en_err(priv,
+ "Total number of TX and XDP rings (%d) exceeds the maximum supported (%d)\n",
+ total_count, MAX_TX_RINGS);
+ goto out;
+ }
err = mlx4_en_try_alloc_resources(priv, tmp, &new_prof, true);
if (err)
goto out;