CONFIG_DIO is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

DIO bus support

configname: CONFIG_DIO

Linux Kernel Configuration
└─>DIO bus support
In linux kernel since version 2.6.12  
Say Y here to enable support for the "DIO" expansion bus used in
HP300 machines. If you are using such a system you almost certainly
want this.

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