[PATCH 5.10 115/142] net/mlx5e: E-switch, Fix rate calculation for overflow

Greg Kroah-Hartman
2021-02-02T14:04:52Z

From: Parav Pandit <parav@nvidia.com>

[ Upstream commit 1fe3e3166b35240615ab7f8276af2bbf2e51f559 ]

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 <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index ce710f22b1fff..98cd5d8b0cd8b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -67,6 +67,7 @@
#include "lib/geneve.h"
#include "lib/fs_chains.h"
#include "diag/en_tc_tracepoint.h"
+#include <asm/div64.h>

#define nic_chains(priv) ((priv)->fs.tc.chains)
#define MLX5_MH_ACT_SZ MLX5_UN_SZ_BYTES(set_add_copy_action_in_auto)
@@ -5009,13 +5010,13 @@ errout:
return err;
}

-static int apply_police_params(struct mlx5e_priv *priv, u32 rate,
+static int apply_police_params(struct mlx5e_priv *priv, u64 rate,
struct netlink_ext_ack *extack)
{
struct mlx5e_rep_priv *rpriv = priv->ppriv;
struct mlx5_eswitch *esw;
+ u32 rate_mbps = 0;
u16 vport_num;
- u32 rate_mbps;
int err;

vport_num = rpriv->rep->vport;
@@ -5032,7 +5033,11 @@ static int apply_police_params(struct mlx5e_priv *priv, u32 rate,
* Moreover, if rate is non zero we choose to configure to a minimum of
* 1 mbit/sec.
*/
- rate_mbps = rate ? max_t(u32, (rate * 8 + 500000) / 1000000, 1) : 0;
+ if (rate) {
+ rate = (rate * BITS_PER_BYTE) + 500000;
+ rate_mbps = max_t(u32, do_div(rate, 1000000), 1);
+ }
+
err = mlx5_esw_modify_vport_rate(esw, vport_num, rate_mbps);
if (err)
NL_SET_ERR_MSG_MOD(extack, "failed applying action to hardware");
--
2.27.0