[PATCH net] net/mlx5e: Skip IPsec flow modify when MAC address is unchanged

[Tariq Toukan <tariqt@nvidia.com>]

From: Jianbo Liu <jianbol@nvidia.com>

When a netdev event fires for an IPsec SA, skip calling
mlx5e_accel_ipsec_fs_modify() if the MAC address has not changed and
the rule is not in drop mode. This avoids a redundant hardware update
when nothing has changed, while still allowing the rule to be restored
when the neighbor becomes reachable again after a drop.

Fixes: 4c24272b4e2b ("net/mlx5e: Listen to ARP events to update IPsec L2 headers in tunnel mode")
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c  | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
index a52e12c3c95a..f567cd801adb 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
@@ -674,19 +674,26 @@ static void mlx5e_ipsec_handle_netdev_event(struct work_struct *_work)
 	struct mlx5e_ipsec_sa_entry *sa_entry = work->sa_entry;
 	struct mlx5e_ipsec_netevent_data *data = work->data;
 	struct mlx5_accel_esp_xfrm_attrs *attrs;
+	u8 *mac;
 
 	attrs = &sa_entry->attrs;
 
 	switch (attrs->dir) {
 	case XFRM_DEV_OFFLOAD_IN:
-		ether_addr_copy(attrs->smac, data->addr);
+		mac = attrs->smac;
 		break;
 	case XFRM_DEV_OFFLOAD_OUT:
-		ether_addr_copy(attrs->dmac, data->addr);
+		mac = attrs->dmac;
 		break;
 	default:
 		WARN_ON_ONCE(true);
+		return;
 	}
+
+	if (ether_addr_equal(mac, data->addr) && !attrs->drop)
+		return;
+
+	ether_addr_copy(mac, data->addr);
 	attrs->drop = false;
 	mlx5e_accel_ipsec_fs_modify(sa_entry);
 }

base-commit: f5b2772d14884f4be9e718644f1203d4d0e6f0d6
-- 
2.44.0