CONFIG_ARC_CACHE_LINE_SHIFT is not available for the default architecture x86.
Result is shown for architecture arc

Cache Line Length (as power of 2)


Linux Kernel Configuration
└─> ARC Architecture Configuration
└─> ARC CPU Configuration
└─> Enable Cache Support
└─> Cache Line Length (as power of 2)

Starting with ARC700 4.9, Cache line length is configurable,
This option specifies "N", with Line-len = 2 power N
So line lengths of 32, 64, 128 are specified by 5,6,7, respectively
Linux only supports same line lengths for I and D caches.