mlxsw: spectrum_router: Extend virtual routers with IPv6 support

A Virtual Router (VR) is an entity which corresponds to a VRF and
performs FIB lookup in an LPM tree according to the {VR, IP Proto} ->
Tree binding.

Extend the virtual router data structure towards IPv6 FIB offload.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

@@ -431,6 +431,7 @@ struct mlxsw_sp_vr {
 	u32 tb_id; /* kernel fib table id */
 	unsigned int rif_count;
 	struct mlxsw_sp_fib *fib4;
+	struct mlxsw_sp_fib *fib6;
 };
 
 static const struct rhashtable_params mlxsw_sp_fib_ht_params;
@@ -628,7 +629,7 @@ static void mlxsw_sp_lpm_fini(struct mlxsw_sp *mlxsw_sp)
 
 static bool mlxsw_sp_vr_is_used(const struct mlxsw_sp_vr *vr)
 {
-	return !!vr->fib4;
+	return !!vr->fib4 || !!vr->fib6;
 }
 
 static struct mlxsw_sp_vr *mlxsw_sp_vr_find_unused(struct mlxsw_sp *mlxsw_sp)
@@ -697,7 +698,7 @@ static struct mlxsw_sp_fib *mlxsw_sp_vr_fib(const struct mlxsw_sp_vr *vr,
 	case MLXSW_SP_L3_PROTO_IPV4:
 		return vr->fib4;
 	case MLXSW_SP_L3_PROTO_IPV6:
-		BUG_ON(1);
+		return vr->fib6;
 	}
 	return NULL;
 }
@@ -706,6 +707,7 @@ static struct mlxsw_sp_vr *mlxsw_sp_vr_create(struct mlxsw_sp *mlxsw_sp,
 					      u32 tb_id)
 {
 	struct mlxsw_sp_vr *vr;
+	int err;
 
 	vr = mlxsw_sp_vr_find_unused(mlxsw_sp);
 	if (!vr)
@@ -713,12 +715,24 @@ static struct mlxsw_sp_vr *mlxsw_sp_vr_create(struct mlxsw_sp *mlxsw_sp,
 	vr->fib4 = mlxsw_sp_fib_create(vr, MLXSW_SP_L3_PROTO_IPV4);
 	if (IS_ERR(vr->fib4))
 		return ERR_CAST(vr->fib4);
+	vr->fib6 = mlxsw_sp_fib_create(vr, MLXSW_SP_L3_PROTO_IPV6);
+	if (IS_ERR(vr->fib6)) {
+		err = PTR_ERR(vr->fib6);
+		goto err_fib6_create;
+	}
 	vr->tb_id = tb_id;
 	return vr;
+
+err_fib6_create:
+	mlxsw_sp_fib_destroy(vr->fib4);
+	vr->fib4 = NULL;
+	return ERR_PTR(err);
 }
 
 static void mlxsw_sp_vr_destroy(struct mlxsw_sp_vr *vr)
 {
+	mlxsw_sp_fib_destroy(vr->fib6);
+	vr->fib6 = NULL;
 	mlxsw_sp_fib_destroy(vr->fib4);
 	vr->fib4 = NULL;
 }
@@ -776,7 +790,8 @@ static struct mlxsw_sp_vr *mlxsw_sp_vr_get(struct mlxsw_sp *mlxsw_sp, u32 tb_id)
 
 static void mlxsw_sp_vr_put(struct mlxsw_sp_vr *vr)
 {
-	if (!vr->rif_count && list_empty(&vr->fib4->node_list))
+	if (!vr->rif_count && list_empty(&vr->fib4->node_list) &&
+	    list_empty(&vr->fib6->node_list))
 		mlxsw_sp_vr_destroy(vr);
 }
 
@@ -2895,6 +2910,13 @@ static void mlxsw_sp_router_fib_flush(struct mlxsw_sp *mlxsw_sp)
 		if (!mlxsw_sp_vr_is_used(vr))
 			continue;
 		mlxsw_sp_vr_fib_flush(mlxsw_sp, vr, MLXSW_SP_L3_PROTO_IPV4);
+
+		/* If virtual router was only used for IPv4, then it's no
+		 * longer used.
+		 */
+		if (!mlxsw_sp_vr_is_used(vr))
+			continue;
+		mlxsw_sp_vr_fib_flush(mlxsw_sp, vr, MLXSW_SP_L3_PROTO_IPV6);
 	}
 }