Following two patches in linux kernel should be integrated into WRL release for PPC atomic operations: https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/arch/powerpc/include/asm/synch.h?id=49e9cf3f0c04bf76ffa59242254110309554861d https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=81d7a3294de7e9828310bbf986a67246b13fa01e
