reproduce:
        git checkout 3fa5e5702a82d259897bd7e209469bc06368bf31
        b4 shazam https://lore.kernel.org/r/20260309-parse_iommu_cells-v10-2-c62fcaa5a1d8@oss.qualcomm.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs