mlxsw: spectrum_router: Allow querying VR ID based on table ID

In the device, different VRFs (routing tables) are represented using
different virtual routers (VRs) and thus the kernel's table IDs are
mapped to VR IDs.

Allow internal users of the IP router to query the VR ID based on a
kernel table ID.

This is needed - for example - when configuring the underlay VR where
VxLAN encapsulated packets will undergo an L3 lookup. In this case, the
kernel's table ID is derived from the VxLAN device's configuration.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -438,6 +438,8 @@ int mlxsw_sp_router_nve_promote_decap(struct mlxsw_sp *mlxsw_sp, u32 ul_tb_id,
 void mlxsw_sp_router_nve_demote_decap(struct mlxsw_sp *mlxsw_sp, u32 ul_tb_id,
 				      enum mlxsw_sp_l3proto ul_proto,
 				      const union mlxsw_sp_l3addr *ul_sip);
+int mlxsw_sp_router_tb_id_vr_id(struct mlxsw_sp *mlxsw_sp, u32 tb_id,
+				u16 *vr_id);
 
 /* spectrum_kvdl.c */
 enum mlxsw_sp_kvdl_entry_type {

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -742,6 +742,19 @@ static struct mlxsw_sp_vr *mlxsw_sp_vr_find(struct mlxsw_sp *mlxsw_sp,
 	return NULL;
 }
 
+int mlxsw_sp_router_tb_id_vr_id(struct mlxsw_sp *mlxsw_sp, u32 tb_id,
+				u16 *vr_id)
+{
+	struct mlxsw_sp_vr *vr;
+
+	vr = mlxsw_sp_vr_find(mlxsw_sp, tb_id);
+	if (!vr)
+		return -ESRCH;
+	*vr_id = vr->id;
+
+	return 0;
+}
+
 static struct mlxsw_sp_fib *mlxsw_sp_vr_fib(const struct mlxsw_sp_vr *vr,
 					    enum mlxsw_sp_l3proto proto)
 {