reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-66-g0196afe1
        # https://github.com/weiny2/linux-kernel/commit/5cda2b55e5656f16f327e45c71af123d9d934fdb
        git remote add weiny2 https://github.com/weiny2/linux-kernel.git
        git fetch --no-tags weiny2 cxl-cper-testing
        git checkout 5cda2b55e5656f16f327e45c71af123d9d934fdb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=i386 olddefconfig
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/acpi/apei/