CONFIG_HAVE_CMPXCHG_DOUBLE (not configurable)

configname: CONFIG_HAVE_CMPXCHG_DOUBLE

Linux Kernel Configuration
└─>General architecture-dependent options
└─>HAVE_CMPXCHG_DOUBLE
In linux kernel since version 3.1 (release Date: 2011-10-24)  
is selected by
CONFIG_AMD_IOMMU