[kbuild-all] Re: irq-loongson-pch-pic.c:undefined reference to `of_iomap'

> Don't we need the dependencies on HAS_IOMEM for the CONFIG_UML=y > case, too? I would have expected that as well, but I don't see the problem when building an arch/um kernel, all I get is ERROR: modpost: "devm_platform_ioremap_resource" [drivers/iio/adc/adi-axi-adc.ko] undefined! ERROR: modpost: "devm_platform_ioremap_resource" [drivers/ptp/ptp_ines.ko] undefined! ERROR: modpost: "devm_ioremap_resource" [drivers/net/ethernet/xilinx/xilinx_emac.ko] undefined! ERROR: modpost: "devm_platform_ioremap_resource_byname" [drivers/net/ethernet/xilinx/ll_temac.ko] undefined! ERROR: modpost: "devm_ioremap" [drivers/net/ethernet/xilinx/ll_temac.ko] undefined! ERROR: modpost: "devm_of_iomap" [drivers/net/ethernet/xilinx/ll_temac.ko] undefined! ERROR: modpost: "__open64_2" [fs/hostfs/hostfs.ko] undefined! If I disable those five drivers, I can build and link a uml kernel without warnings. I could not find the difference compared to s390 here. Looking a bit further, I now find that we ended up disabling CONFIG_COMPILE_TEST entirely for arch/um, which is clearly an option that would also work for s390.