net/mlx5e: Add header re-write offloading of IPv6 hop-limit

For environments where flow-based ipv6 router is offloaded.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: NPaul Blakey <paulb@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

@@ -1081,6 +1081,7 @@ static struct mlx5_fields fields[] = {
 	OFFLOAD(DIPV6_95_64,  4, ip6.daddr.s6_addr32[1], 0),
 	OFFLOAD(DIPV6_63_32,  4, ip6.daddr.s6_addr32[2], 0),
 	OFFLOAD(DIPV6_31_0,   4, ip6.daddr.s6_addr32[3], 0),
+	OFFLOAD(IPV6_HOPLIMIT, 1, ip6.hop_limit, 0),
 
 	OFFLOAD(TCP_SPORT, 2, tcp.source,  0),
 	OFFLOAD(TCP_DPORT, 2, tcp.dest,    0),

include/linux/mlx5/mlx5_ifc.h

@@ -4620,6 +4620,7 @@ enum {
 	MLX5_ACTION_IN_FIELD_OUT_DIPV6_31_0    = 0x14,
 	MLX5_ACTION_IN_FIELD_OUT_SIPV4         = 0x15,
 	MLX5_ACTION_IN_FIELD_OUT_DIPV4         = 0x16,
+	MLX5_ACTION_IN_FIELD_OUT_IPV6_HOPLIMIT = 0x47,
 };
 
 struct mlx5_ifc_alloc_modify_header_context_out_bits {