Kernel/READ PORT BUFFER USHORT

Also see https://msdn.microsoft.com/en-us/library/windows/hardware/ff560794(v=vs.85).aspx

Disassembly

mov  eax, edi
mov  edx, [esp+4]
mov  edi, [esp+8]
mov  ecx, [esp+12]
rep insw
mov  edi, eax
ret 12