CONFIG_NIOS2_DCACHE_SIZE is not available for thedefaultarchitecture x86.
Result is shown for architecture nios2
D-Cache size
configname: CONFIG_NIOS2_DCACHE_SIZE
Linux Kernel Configuration
└─>Platform options
└─>D-Cache size
In linux kernel since version 3.19 (release Date: 2015-02-08)
Maximum possible data cache size.