ERROR: "min_low_pfn" undefined!

[kernel test robot]

Hi Jiri,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   d52daa8620c65960e1ef882adc1f92061326bd7a
commit: aebe5fc3b5685e1d9b86cc8314a8e8f3c6f3284e n_hdlc: put init/exit strings directly to prints
date:   5 months ago
config: microblaze-randconfig-r026-20200801 (attached as .config)
compiler: microblaze-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout aebe5fc3b5685e1d9b86cc8314a8e8f3c6f3284e
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=microblaze 

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

All errors (new ones prefixed by >>):

   ERROR: "min_low_pfn" [drivers/block/aoe/aoe.ko] undefined!
>> ERROR: "min_low_pfn" [drivers/mtd/nand/raw/cadence-nand-controller.ko] undefined!
>> ERROR: "min_low_pfn" [drivers/mtd/nand/raw/nand.ko] undefined!

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

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