Hi Niklas,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   ec2618180c3450d06a6a4ba951d4c9a2c689b517
commit: 5ae6eadfdaf431f47adbdf1754f3b5a5fd638de2 [1527/2770] asm-generic/io.h: warn in inb() and friends with undefined PCI_IOBASE
config: um-randconfig-r031-20210513 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=5ae6eadfdaf431f47adbdf1754f3b5a5fd638de2
        git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
        git fetch --no-tags linux-next master
        git checkout 5ae6eadfdaf431f47adbdf1754f3b5a5fd638de2
        # save the attached .config to linux build tree
        make W=1 W=1 ARCH=um 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

ERROR: modpost: "X86_FEATURE_XMM" [drivers/fpga/altera-pr-ip-core.ko] undefined!
ERROR: modpost: "X86_FEATURE_XMM2" [drivers/fpga/altera-pr-ip-core.ko] undefined!
>> ERROR: modpost: "X86_FEATURE_XMM2" [drivers/mtd/nand/raw/nand.ko] undefined!
ERROR: modpost: "__divdi3" [fs/hostfs/hostfs.ko] undefined!

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for LOCKDEP
   Depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT && (FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86)
   Selected by
   - PROVE_LOCKING && DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
   - DEBUG_LOCK_ALLOC && DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org