default or selected kernelversion does not have config value CONFIG_ARCH_SUPPORTS_ATOMIC_RMW.
Result is shown for kernelversion 6.9-rc5

CONFIG_ARCH_SUPPORTS_ATOMIC_RMW (not configurable)

configname: CONFIG_ARCH_SUPPORTS_ATOMIC_RMW

Linux Kernel Configuration
└─>ARCH_SUPPORTS_ATOMIC_RMW
In linux kernel since version 3.10.2 (release Date: 2013-07-21)