reproduce:
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # apt-get install sparse
        # sparse version: v0.6.4-66-g0196afe1
        # https://github.com/intel-lab-lkp/linux/commit/00a1768a5a097effa4199fafb78082b18d554e30
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Terry-Bowman/PCI-CXL-Introduce-PCIe-helper-function-pcie_is_cxl/20250327-095738
        git checkout 00a1768a5a097effa4199fafb78082b18d554e30
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.4.0 ~/lkp-tests/kbuild/make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=csky olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.4.0 ~/lkp-tests/kbuild/make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=csky SHELL=/bin/bash drivers/cxl/