mlx5: implement VLAN tag XDP hint

Implement the newly added .xmo_rx_vlan_tag() hint function.
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://lore.kernel.org/r/20231205210847.28460-15-larysa.zaremba@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c

@@ -256,9 +256,24 @@ static int mlx5e_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
 	return 0;
 }
 
+static int mlx5e_xdp_rx_vlan_tag(const struct xdp_md *ctx, __be16 *vlan_proto,
+				 u16 *vlan_tci)
+{
+	const struct mlx5e_xdp_buff *_ctx = (void *)ctx;
+	const struct mlx5_cqe64 *cqe = _ctx->cqe;
+
+	if (!cqe_has_vlan(cqe))
+		return -ENODATA;
+
+	*vlan_proto = htons(ETH_P_8021Q);
+	*vlan_tci = be16_to_cpu(cqe->vlan_info);
+	return 0;
+}
+
 const struct xdp_metadata_ops mlx5e_xdp_metadata_ops = {
 	.xmo_rx_timestamp		= mlx5e_xdp_rx_timestamp,
 	.xmo_rx_hash			= mlx5e_xdp_rx_hash,
+	.xmo_rx_vlan_tag		= mlx5e_xdp_rx_vlan_tag,
 };
 
 struct mlx5e_xsk_tx_complete {

include/linux/mlx5/device.h

@@ -918,7 +918,7 @@ static inline u8 get_cqe_tls_offload(struct mlx5_cqe64 *cqe)
 	return (cqe->tls_outer_l3_tunneled >> 3) & 0x3;
 }
 
-static inline bool cqe_has_vlan(struct mlx5_cqe64 *cqe)
+static inline bool cqe_has_vlan(const struct mlx5_cqe64 *cqe)
 {
 	return cqe->l4_l3_hdr_type & 0x1;
 }