Subject: [net 01/15] net/mlx5e: E-switch, Fix rate calculation for overflow

From: Saeed Mahameed <[email-masked]>
Date: Thu, 11 Feb 2021 18:56:27 -0800

From: Parav Pandit <[email-masked]>

rate_bytes_ps is a 64-bit field. It passed as 32-bit field to
apply_police_params(). Due to this when police rate is higher
than 4Gbps, 32-bit calculation ignores the carry. This results
in incorrect rate configurationn the device.

Fix it by performing 64-bit calculation.

Fixes: fcb64c0f5640 ("net/mlx5: E-Switch, add ingress rate support")
Signed-off-by: Parav Pandit <[email-masked]>
Reviewed-by: Eli Cohen <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index dd0bfbacad47..717fbaa6ce73 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -5040,7 +5040,7 @@ static int apply_police_params(struct mlx5e_priv *priv, u64 rate,
 	 */
 	if (rate) {
 		rate = (rate * BITS_PER_BYTE) + 500000;
-		rate_mbps = max_t(u32, do_div(rate, 1000000), 1);
+		rate_mbps = max_t(u64, do_div(rate, 1000000), 1);
 	}
 
 	err = mlx5_esw_modify_vport_rate(esw, vport_num, rate_mbps);
-- 
2.29.2