6.12-stable review patch. If anyone has any objections, please let me know.

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From: Gal Pressman gal@nvidia.com

[ Upstream commit a7bf4d5063c7837096aab2853224eb23628514d9 ]

The previous calculation used roundup() which caused an overflow for rates between 25.5Gbps and 26Gbps. For example, a rate of 25.6Gbps would result in using 100Mbps units with value of 256, which would overflow the 8 bits field.

Simplify the upper_limit_mbps calculation by removing the unnecessary roundup, and adjust the comparison to use <= to correctly handle the boundary condition.

Fixes: d8880795dabf ("net/mlx5e: Implement DCBNL IEEE max rate") Signed-off-by: Gal Pressman gal@nvidia.com Reviewed-by: Nimrod Oren noren@nvidia.com Signed-off-by: Tariq Toukan tariqt@nvidia.com Link: https://patch.msgid.link/1762681073-1084058-4-git-send-email-tariqt@nvidia.c... Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c index b08328fe1aa30..99ee288ed43a4 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c @@ -595,18 +595,19 @@ static int mlx5e_dcbnl_ieee_setmaxrate(struct net_device *netdev, struct mlx5_core_dev *mdev = priv->mdev; u8 max_bw_value[IEEE_8021QAZ_MAX_TCS]; u8 max_bw_unit[IEEE_8021QAZ_MAX_TCS]; - __u64 upper_limit_mbps = roundup(255 * MLX5E_100MB, MLX5E_1GB); + __u64 upper_limit_mbps; int i;

memset(max_bw_value, 0, sizeof(max_bw_value)); memset(max_bw_unit, 0, sizeof(max_bw_unit)); + upper_limit_mbps = 255 * MLX5E_100MB;

for (i = 0; i <= mlx5_max_tc(mdev); i++) { if (!maxrate->tc_maxrate[i]) { max_bw_unit[i] = MLX5_BW_NO_LIMIT; continue; } - if (maxrate->tc_maxrate[i] < upper_limit_mbps) { + if (maxrate->tc_maxrate[i] <= upper_limit_mbps) { max_bw_value[i] = div_u64(maxrate->tc_maxrate[i], MLX5E_100MB); max_bw_value[i] = max_bw_value[i] ? max_bw_value[i] : 1;