mlxsw: spectrum_router: Use the nodes list as indication for empty FIB

Currently, each FIB (IPv4 / IPv6) in a virtual router holds a prefix
usage that is used to choose a matching LPM tree, but also to check if
the FIB is empty, so that the LPM tree could be unbound.

Next patches will remove the reliance on the per-FIB prefix usage for
LPM tree matching. Keeping it only to check if the FIB is empty is a
waste, since we can use the nodes ({Prefix, Length}) list instead.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 9 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 31891ae11c9b..634e427fb80e 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -349,14 +349,6 @@ mlxsw_sp_prefix_usage_eq(struct mlxsw_sp_prefix_usage *prefix_usage1,
         return !memcmp(prefix_usage1, prefix_usage2, sizeof(*prefix_usage1));
 }
 
-static bool
-mlxsw_sp_prefix_usage_none(struct mlxsw_sp_prefix_usage *prefix_usage)
-{
-        struct mlxsw_sp_prefix_usage prefix_usage_none = {{ 0 } };
-
-        return mlxsw_sp_prefix_usage_eq(prefix_usage, &prefix_usage_none);
-}
-
 static void
 mlxsw_sp_prefix_usage_cpy(struct mlxsw_sp_prefix_usage *prefix_usage1,
                           struct mlxsw_sp_prefix_usage *prefix_usage2)
@@ -4240,8 +4232,11 @@ static int mlxsw_sp_fib_lpm_tree_link(struct mlxsw_sp *mlxsw_sp,
 static void mlxsw_sp_fib_lpm_tree_unlink(struct mlxsw_sp *mlxsw_sp,
                                          struct mlxsw_sp_fib *fib)
 {
-        if (!mlxsw_sp_prefix_usage_none(&fib->prefix_usage))
+        if (!list_is_singular(&fib->node_list))
                 return;
+        /* Last node is being unlinked from the FIB. Unbind the
+         * tree and drop the reference.
+         */
         mlxsw_sp_vr_lpm_tree_unbind(mlxsw_sp, fib);
         mlxsw_sp_lpm_tree_put(mlxsw_sp, fib->lpm_tree);
         fib->lpm_tree = NULL;