[PATCH net-next 1/5] net/mlx5e: Return -EOPNOTSUPP when modify header action zero

[xiangxia . m . yue]

From: Tonghao Zhang <xiangxia.m....@gmail.com>

When max modify header action is zero, we return -EOPNOTSUPP
directly. In this way, we can ignore wrong message info (e.g.
"mlx5: parsed 0 pedit actions, can't do more").

This happens when offloading pedit actions on mlx VFs.

For example:
$ tc filter add dev mlx_vfs parent ffff: protocol ip prio 1 \
        flower skip_sw dst_mac 00:10:56:fb:64:e8 \
        dst_ip 1.1.1.100 src_ip 1.1.1.200 \
        action pedit ex munge eth src set 00:10:56:b4:5d:20

Signed-off-by: Tonghao Zhang <xiangxia.m....@gmail.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c 
b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index b38986e..c4359f1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2002,7 +2002,8 @@ static int offload_pedit_fields(struct 
pedit_headers_action *hdrs,
 static int alloc_mod_hdr_actions(struct mlx5e_priv *priv,
                                 struct pedit_headers_action *hdrs,
                                 int namespace,
-                                struct mlx5e_tc_flow_parse_attr *parse_attr)
+                                struct mlx5e_tc_flow_parse_attr *parse_attr,
+                                struct netlink_ext_ack *extack)
 {
        int nkeys, action_size, max_actions;
 
@@ -2015,6 +2016,13 @@ static int alloc_mod_hdr_actions(struct mlx5e_priv *priv,
        else /* namespace is MLX5_FLOW_NAMESPACE_KERNEL - NIC offloading */
                max_actions = MLX5_CAP_FLOWTABLE_NIC_RX(priv->mdev, 
max_modify_header_actions);
 
+       if (!max_actions) {
+               NL_SET_ERR_MSG_MOD(extack,
+                                  "don't support pedit actions, can't 
offload");
+               netdev_warn(priv->netdev, "don't support pedit actions, can't 
offload\n");
+               return -EOPNOTSUPP;
+       }
+
        /* can get up to crazingly 16 HW actions in 32 bits pedit SW key */
        max_actions = min(max_actions, nkeys * 16);
 
@@ -2072,7 +2080,8 @@ static int alloc_tc_pedit_action(struct mlx5e_priv *priv, 
int namespace,
        u8 cmd;
 
        if (!parse_attr->mod_hdr_actions) {
-               err = alloc_mod_hdr_actions(priv, hdrs, namespace, parse_attr);
+               err = alloc_mod_hdr_actions(priv, hdrs,
+                                           namespace, parse_attr, extack);
                if (err)
                        goto out_err;
        }
-- 
1.8.3.1