mlxsw: spectrum_router: Make nexthops typed

In the router, some next hops may reference an encapsulating netdevice,
such as GRE or IPIP. To properly offload these next hops, mlxsw needs to
keep track of whether a given next hop is a regular Ethernet entry, or
an IP-in-IP tunneling entry.

To facilitate this book-keeping, add a type field to struct
mlxsw_sp_nexthop. There is, as of this patch, only one next hop type:
MLXSW_SP_NEXTHOP_TYPE_ETH. Follow-up patches will introduce the IP-in-IP
variant.

There are several places where next hops are initialized in the IPv4
path. Instead of replicating the logic at every one of them, factor it
out to a function mlxsw_sp_nexthop4_type_init(). The corresponding fini
is actually protocol-neutral, so put it to mlxsw_sp_nexthop_type_fini(),
but create a corresponding protocoled _fini function that dispatches to
the protocol-neutral one.

The IPv6 path is simpler, but for symmetry with IPv4, create the same
suite of functions with corresponding logic.

Signed-off-by: Petr Machata <[email protected]>
Reviewed-by: Ido Schimmel <[email protected]>
Signed-off-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: pmachata

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

@@ -1652,6 +1652,10 @@ static void mlxsw_sp_neigh_rif_gone_sync(struct mlxsw_sp *mlxsw_sp,
 	}
 }
 
+enum mlxsw_sp_nexthop_type {
+	MLXSW_SP_NEXTHOP_TYPE_ETH,
+};
+
 struct mlxsw_sp_nexthop_key {
 	struct fib_nh *fib_nh;
 };
@@ -1676,7 +1680,10 @@ struct mlxsw_sp_nexthop {
 	   update:1; /* set indicates that MAC of this neigh should be
 		      * updated in HW
 		      */
-	struct mlxsw_sp_neigh_entry *neigh_entry;
+	enum mlxsw_sp_nexthop_type type;
+	union {
+		struct mlxsw_sp_neigh_entry *neigh_entry;
+	};
 };
 
 struct mlxsw_sp_nexthop_group {
@@ -1964,9 +1971,9 @@ static int mlxsw_sp_nexthop_mac_update(struct mlxsw_sp *mlxsw_sp, u32 adj_index,
 }
 
 static int
-mlxsw_sp_nexthop_group_mac_update(struct mlxsw_sp *mlxsw_sp,
-				  struct mlxsw_sp_nexthop_group *nh_grp,
-				  bool reallocate)
+mlxsw_sp_nexthop_group_update(struct mlxsw_sp *mlxsw_sp,
+			      struct mlxsw_sp_nexthop_group *nh_grp,
+			      bool reallocate)
 {
 	u32 adj_index = nh_grp->adj_index; /* base */
 	struct mlxsw_sp_nexthop *nh;
@@ -1982,8 +1989,12 @@ mlxsw_sp_nexthop_group_mac_update(struct mlxsw_sp *mlxsw_sp,
 		}
 
 		if (nh->update || reallocate) {
-			err = mlxsw_sp_nexthop_mac_update(mlxsw_sp,
-							  adj_index, nh);
+			switch (nh->type) {
+			case MLXSW_SP_NEXTHOP_TYPE_ETH:
+				err = mlxsw_sp_nexthop_mac_update
+					    (mlxsw_sp, adj_index, nh);
+				break;
+			}
 			if (err)
 				return err;
 			nh->update = 0;
@@ -2071,8 +2082,7 @@ mlxsw_sp_nexthop_group_refresh(struct mlxsw_sp *mlxsw_sp,
 		/* Nothing was added or removed, so no need to reallocate. Just
 		 * update MAC on existing adjacency indexes.
 		 */
-		err = mlxsw_sp_nexthop_group_mac_update(mlxsw_sp, nh_grp,
-							false);
+		err = mlxsw_sp_nexthop_group_update(mlxsw_sp, nh_grp, false);
 		if (err) {
 			dev_warn(mlxsw_sp->bus_info->dev, "Failed to update neigh MAC in adjacency table.\n");
 			goto set_trap;
@@ -2099,7 +2109,7 @@ mlxsw_sp_nexthop_group_refresh(struct mlxsw_sp *mlxsw_sp,
 	nh_grp->adj_index_valid = 1;
 	nh_grp->adj_index = adj_index;
 	nh_grp->ecmp_size = ecmp_size;
-	err = mlxsw_sp_nexthop_group_mac_update(mlxsw_sp, nh_grp, true);
+	err = mlxsw_sp_nexthop_group_update(mlxsw_sp, nh_grp, true);
 	if (err) {
 		dev_warn(mlxsw_sp->bus_info->dev, "Failed to update neigh MAC in adjacency table.\n");
 		goto set_trap;
@@ -2287,14 +2297,55 @@ static bool mlxsw_sp_netdev_ipip_type(const struct mlxsw_sp *mlxsw_sp,
 	return false;
 }
 
+static void mlxsw_sp_nexthop_type_fini(struct mlxsw_sp *mlxsw_sp,
+				       struct mlxsw_sp_nexthop *nh)
+{
+	switch (nh->type) {
+	case MLXSW_SP_NEXTHOP_TYPE_ETH:
+		mlxsw_sp_nexthop_neigh_fini(mlxsw_sp, nh);
+		mlxsw_sp_nexthop_rif_fini(nh);
+		break;
+	}
+}
+
+static int mlxsw_sp_nexthop4_type_init(struct mlxsw_sp *mlxsw_sp,
+				       struct mlxsw_sp_nexthop *nh,
+				       struct fib_nh *fib_nh)
+{
+	struct net_device *dev = fib_nh->nh_dev;
+	struct mlxsw_sp_rif *rif;
+	int err;
+
+	nh->type = MLXSW_SP_NEXTHOP_TYPE_ETH;
+	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, dev);
+	if (!rif)
+		return 0;
+
+	mlxsw_sp_nexthop_rif_init(nh, rif);
+	err = mlxsw_sp_nexthop_neigh_init(mlxsw_sp, nh);
+	if (err)
+		goto err_neigh_init;
+
+	return 0;
+
+err_neigh_init:
+	mlxsw_sp_nexthop_rif_fini(nh);
+	return err;
+}
+
+static void mlxsw_sp_nexthop4_type_fini(struct mlxsw_sp *mlxsw_sp,
+					struct mlxsw_sp_nexthop *nh)
+{
+	mlxsw_sp_nexthop_type_fini(mlxsw_sp, nh);
+}
+
 static int mlxsw_sp_nexthop4_init(struct mlxsw_sp *mlxsw_sp,
 				  struct mlxsw_sp_nexthop_group *nh_grp,
 				  struct mlxsw_sp_nexthop *nh,
 				  struct fib_nh *fib_nh)
 {
 	struct net_device *dev = fib_nh->nh_dev;
 	struct in_device *in_dev;
-	struct mlxsw_sp_rif *rif;
 	int err;
 
 	nh->nh_grp = nh_grp;
@@ -2312,28 +2363,21 @@ static int mlxsw_sp_nexthop4_init(struct mlxsw_sp *mlxsw_sp,
 	    fib_nh->nh_flags & RTNH_F_LINKDOWN)
 		return 0;
 
-	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, dev);
-	if (!rif)
-		return 0;
-	mlxsw_sp_nexthop_rif_init(nh, rif);
-
-	err = mlxsw_sp_nexthop_neigh_init(mlxsw_sp, nh);
+	err = mlxsw_sp_nexthop4_type_init(mlxsw_sp, nh, fib_nh);
 	if (err)
 		goto err_nexthop_neigh_init;
 
 	return 0;
 
 err_nexthop_neigh_init:
-	mlxsw_sp_nexthop_rif_fini(nh);
 	mlxsw_sp_nexthop_remove(mlxsw_sp, nh);
 	return err;
 }
 
 static void mlxsw_sp_nexthop4_fini(struct mlxsw_sp *mlxsw_sp,
 				   struct mlxsw_sp_nexthop *nh)
 {
-	mlxsw_sp_nexthop_neigh_fini(mlxsw_sp, nh);
-	mlxsw_sp_nexthop_rif_fini(nh);
+	mlxsw_sp_nexthop4_type_fini(mlxsw_sp, nh);
 	mlxsw_sp_nexthop_remove(mlxsw_sp, nh);
 }
 
@@ -2342,7 +2386,6 @@ static void mlxsw_sp_nexthop4_event(struct mlxsw_sp *mlxsw_sp,
 {
 	struct mlxsw_sp_nexthop_key key;
 	struct mlxsw_sp_nexthop *nh;
-	struct mlxsw_sp_rif *rif;
 
 	if (mlxsw_sp->router->aborted)
 		return;
@@ -2352,18 +2395,12 @@ static void mlxsw_sp_nexthop4_event(struct mlxsw_sp *mlxsw_sp,
 	if (WARN_ON_ONCE(!nh))
 		return;
 
-	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, fib_nh->nh_dev);
-	if (!rif)
-		return;
-
 	switch (event) {
 	case FIB_EVENT_NH_ADD:
-		mlxsw_sp_nexthop_rif_init(nh, rif);
-		mlxsw_sp_nexthop_neigh_init(mlxsw_sp, nh);
+		mlxsw_sp_nexthop4_type_init(mlxsw_sp, nh, fib_nh);
 		break;
 	case FIB_EVENT_NH_DEL:
-		mlxsw_sp_nexthop_neigh_fini(mlxsw_sp, nh);
-		mlxsw_sp_nexthop_rif_fini(nh);
+		mlxsw_sp_nexthop4_type_fini(mlxsw_sp, nh);
 		break;
 	}
 
@@ -2376,8 +2413,7 @@ static void mlxsw_sp_nexthop_rif_gone_sync(struct mlxsw_sp *mlxsw_sp,
 	struct mlxsw_sp_nexthop *nh, *tmp;
 
 	list_for_each_entry_safe(nh, tmp, &rif->nexthop_list, rif_list_node) {
-		mlxsw_sp_nexthop_neigh_fini(mlxsw_sp, nh);
-		mlxsw_sp_nexthop_rif_fini(nh);
+		mlxsw_sp_nexthop_type_fini(mlxsw_sp, nh);
 		mlxsw_sp_nexthop_group_refresh(mlxsw_sp, nh->nh_grp);
 	}
 }
@@ -3487,22 +3523,16 @@ mlxsw_sp_fib6_entry_rt_find(const struct mlxsw_sp_fib6_entry *fib6_entry,
 	return NULL;
 }
 
-static int mlxsw_sp_nexthop6_init(struct mlxsw_sp *mlxsw_sp,
-				  struct mlxsw_sp_nexthop_group *nh_grp,
-				  struct mlxsw_sp_nexthop *nh,
-				  const struct rt6_info *rt)
+static int mlxsw_sp_nexthop6_type_init(struct mlxsw_sp *mlxsw_sp,
+				       struct mlxsw_sp_nexthop_group *nh_grp,
+				       struct mlxsw_sp_nexthop *nh,
+				       const struct rt6_info *rt)
 {
 	struct net_device *dev = rt->dst.dev;
 	struct mlxsw_sp_rif *rif;
 	int err;
 
-	nh->nh_grp = nh_grp;
-	memcpy(&nh->gw_addr, &rt->rt6i_gateway, sizeof(nh->gw_addr));
-
-	if (!dev)
-		return 0;
-	nh->ifindex = dev->ifindex;
-
+	nh->type = MLXSW_SP_NEXTHOP_TYPE_ETH;
 	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, dev);
 	if (!rif)
 		return 0;
@@ -3519,11 +3549,33 @@ static int mlxsw_sp_nexthop6_init(struct mlxsw_sp *mlxsw_sp,
 	return err;
 }
 
+static void mlxsw_sp_nexthop6_type_fini(struct mlxsw_sp *mlxsw_sp,
+					struct mlxsw_sp_nexthop *nh)
+{
+	mlxsw_sp_nexthop_type_fini(mlxsw_sp, nh);
+}
+
+static int mlxsw_sp_nexthop6_init(struct mlxsw_sp *mlxsw_sp,
+				  struct mlxsw_sp_nexthop_group *nh_grp,
+				  struct mlxsw_sp_nexthop *nh,
+				  const struct rt6_info *rt)
+{
+	struct net_device *dev = rt->dst.dev;
+
+	nh->nh_grp = nh_grp;
+	memcpy(&nh->gw_addr, &rt->rt6i_gateway, sizeof(nh->gw_addr));
+
+	if (!dev)
+		return 0;
+	nh->ifindex = dev->ifindex;
+
+	return mlxsw_sp_nexthop6_type_init(mlxsw_sp, nh_grp, nh, rt);
+}
+
 static void mlxsw_sp_nexthop6_fini(struct mlxsw_sp *mlxsw_sp,
 				   struct mlxsw_sp_nexthop *nh)
 {
-	mlxsw_sp_nexthop_neigh_fini(mlxsw_sp, nh);
-	mlxsw_sp_nexthop_rif_fini(nh);
+	mlxsw_sp_nexthop6_type_fini(mlxsw_sp, nh);
 }
 
 static bool mlxsw_sp_rt6_is_gateway(const struct mlxsw_sp *mlxsw_sp,