CONFIG_HARDWALL is not available for thedefaultarchitecture x86.
Result is shown for architecture tile
default or selected kernelversion does not have config value CONFIG_HARDWALL.
Result is shown for kernelversion 6.7-rc3

Hardwall support to allow access to user dynamic network

modulename: hardwall.ko

configname: CONFIG_HARDWALL

Linux Kernel Configuration
└─>Tilera-specific configuration
└─>Hardwall support to allow access to user dynamic network
In linux kernel since version 2.6.36 (release Date: 2010-10-20)  
source code:
arch/tile/kernel/hardwall.c