mlxsw: spectrum_router: Prepare nexthop group's hash table for IPv6

This patch does preparation before introducing IPv6 nexthop group
consolidation. Currently the nexthop group hash table is used only by
IPv4 and uses fixed key size. In order to support the IPv6's variable
length key the current table is changed.
Signed-off-by: NArkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-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

@@ -1522,15 +1522,11 @@ struct mlxsw_sp_nexthop {
 	struct mlxsw_sp_neigh_entry *neigh_entry;
 };
 
-struct mlxsw_sp_nexthop_group_key {
-	struct fib_info *fi;
-};
-
 struct mlxsw_sp_nexthop_group {
+	void *priv;
 	struct rhash_head ht_node;
 	struct list_head fib_list; /* list of fib entries that use this group */
 	struct neigh_table *neigh_tbl;
-	struct mlxsw_sp_nexthop_group_key key;
 	u8 adj_index_valid:1,
 	   gateway:1; /* routes using the group use a gateway */
 	u32 adj_index;
@@ -1540,10 +1536,46 @@ struct mlxsw_sp_nexthop_group {
 #define nh_rif	nexthops[0].rif
 };
 
+static struct fib_info *
+mlxsw_sp_nexthop4_group_fi(const struct mlxsw_sp_nexthop_group *nh_grp)
+{
+	return nh_grp->priv;
+}
+
+struct mlxsw_sp_nexthop_group_cmp_arg {
+	struct fib_info *fi;
+};
+
+static int
+mlxsw_sp_nexthop_group_cmp(struct rhashtable_compare_arg *arg, const void *ptr)
+{
+	const struct mlxsw_sp_nexthop_group_cmp_arg *cmp_arg = arg->key;
+	const struct mlxsw_sp_nexthop_group *nh_grp = ptr;
+
+	return cmp_arg->fi != mlxsw_sp_nexthop4_group_fi(nh_grp);
+}
+
+static u32 mlxsw_sp_nexthop_group_hash_obj(const void *data, u32 len, u32 seed)
+{
+	const struct mlxsw_sp_nexthop_group *nh_grp = data;
+	struct fib_info *fi = mlxsw_sp_nexthop4_group_fi(nh_grp);
+
+	return jhash(&fi, sizeof(fi), seed);
+}
+
+static u32
+mlxsw_sp_nexthop_group_hash(const void *data, u32 len, u32 seed)
+{
+	const struct mlxsw_sp_nexthop_group_cmp_arg *cmp_arg = data;
+
+	return jhash(&cmp_arg->fi, sizeof(cmp_arg->fi), seed);
+}
+
 static const struct rhashtable_params mlxsw_sp_nexthop_group_ht_params = {
-	.key_offset = offsetof(struct mlxsw_sp_nexthop_group, key),
 	.head_offset = offsetof(struct mlxsw_sp_nexthop_group, ht_node),
-	.key_len = sizeof(struct mlxsw_sp_nexthop_group_key),
+	.hashfn	     = mlxsw_sp_nexthop_group_hash,
+	.obj_hashfn  = mlxsw_sp_nexthop_group_hash_obj,
+	.obj_cmpfn   = mlxsw_sp_nexthop_group_cmp,
 };
 
 static int mlxsw_sp_nexthop_group_insert(struct mlxsw_sp *mlxsw_sp,
@@ -1563,10 +1595,14 @@ static void mlxsw_sp_nexthop_group_remove(struct mlxsw_sp *mlxsw_sp,
 }
 
 static struct mlxsw_sp_nexthop_group *
-mlxsw_sp_nexthop_group_lookup(struct mlxsw_sp *mlxsw_sp,
-			      struct mlxsw_sp_nexthop_group_key key)
+mlxsw_sp_nexthop4_group_lookup(struct mlxsw_sp *mlxsw_sp,
+			       struct fib_info *fi)
 {
-	return rhashtable_lookup_fast(&mlxsw_sp->router->nexthop_group_ht, &key,
+	struct mlxsw_sp_nexthop_group_cmp_arg cmp_arg;
+
+	cmp_arg.fi = fi;
+	return rhashtable_lookup_fast(&mlxsw_sp->router->nexthop_group_ht,
+				      &cmp_arg,
 				      mlxsw_sp_nexthop_group_ht_params);
 }
 
@@ -2063,12 +2099,12 @@ mlxsw_sp_nexthop4_group_create(struct mlxsw_sp *mlxsw_sp, struct fib_info *fi)
 	nh_grp = kzalloc(alloc_size, GFP_KERNEL);
 	if (!nh_grp)
 		return ERR_PTR(-ENOMEM);
+	nh_grp->priv = fi;
 	INIT_LIST_HEAD(&nh_grp->fib_list);
 	nh_grp->neigh_tbl = &arp_tbl;
 
 	nh_grp->gateway = fi->fib_nh->nh_scope == RT_SCOPE_LINK;
 	nh_grp->count = fi->fib_nhs;
-	nh_grp->key.fi = fi;
 	fib_info_hold(fi);
 	for (i = 0; i < nh_grp->count; i++) {
 		nh = &nh_grp->nexthops[i];
@@ -2089,7 +2125,7 @@ mlxsw_sp_nexthop4_group_create(struct mlxsw_sp *mlxsw_sp, struct fib_info *fi)
 		nh = &nh_grp->nexthops[i];
 		mlxsw_sp_nexthop4_fini(mlxsw_sp, nh);
 	}
-	fib_info_put(nh_grp->key.fi);
+	fib_info_put(fi);
 	kfree(nh_grp);
 	return ERR_PTR(err);
 }
@@ -2108,7 +2144,7 @@ mlxsw_sp_nexthop4_group_destroy(struct mlxsw_sp *mlxsw_sp,
 	}
 	mlxsw_sp_nexthop_group_refresh(mlxsw_sp, nh_grp);
 	WARN_ON_ONCE(nh_grp->adj_index_valid);
-	fib_info_put(nh_grp->key.fi);
+	fib_info_put(mlxsw_sp_nexthop4_group_fi(nh_grp));
 	kfree(nh_grp);
 }
 
@@ -2116,11 +2152,9 @@ static int mlxsw_sp_nexthop4_group_get(struct mlxsw_sp *mlxsw_sp,
 				       struct mlxsw_sp_fib_entry *fib_entry,
 				       struct fib_info *fi)
 {
-	struct mlxsw_sp_nexthop_group_key key;
 	struct mlxsw_sp_nexthop_group *nh_grp;
 
-	key.fi = fi;
-	nh_grp = mlxsw_sp_nexthop_group_lookup(mlxsw_sp, key);
+	nh_grp = mlxsw_sp_nexthop4_group_lookup(mlxsw_sp, fi);
 	if (!nh_grp) {
 		nh_grp = mlxsw_sp_nexthop4_group_create(mlxsw_sp, fi);
 		if (IS_ERR(nh_grp))
@@ -2551,7 +2585,8 @@ mlxsw_sp_fib4_entry_lookup(struct mlxsw_sp *mlxsw_sp,
 		if (fib4_entry->tb_id == fen_info->tb_id &&
 		    fib4_entry->tos == fen_info->tos &&
 		    fib4_entry->type == fen_info->type &&
-		    fib4_entry->common.nh_group->key.fi == fen_info->fi) {
+		    mlxsw_sp_nexthop4_group_fi(fib4_entry->common.nh_group) ==
+		    fen_info->fi) {
 			return fib4_entry;
 		}
 	}