/dev/cpu/*/cpuid - CPU information support

modulename: cpuid.ko

configname: CONFIG_X86_CPUID

Linux Kernel Configuration
└─>Processor type and features
└─>/dev/cpu/*/cpuid - CPU information support
In linux kernel since version 2.6.12  
This device gives processes access to the x86 CPUID instruction to
be executed on a specific processor. It is a character device
with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to

source code: