Hi Anshuman,

[FYI, it's a private test report for your RFC patch.]
[auto build test WARNING on v5.10-rc6]
[cannot apply to mmotm/master s390/features arm64/for-next/core hnaz-linux-mm/master next-20201127]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Anshuman-Khandual/mm-hotplug-Pre-validate-the-address-range-with-platform/20201130-113145
base:    b65054597872ce3aefbc6a666385eabdf9e288da
config: arm64-allyesconfig (attached as .config)
compiler: aarch64-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
        # https://github.com/0day-ci/linux/commit/7d8145ca97fc2f90d8378399cf1823cfd90049be
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Anshuman-Khandual/mm-hotplug-Pre-validate-the-address-range-with-platform/20201130-113145
        git checkout 7d8145ca97fc2f90d8378399cf1823cfd90049be
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm64 

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

All warnings (new ones prefixed by >>):

>> arch/arm64/mm/mmu.c:1447:14: warning: no previous prototype for 'arch_get_mappable_range' [-Wmissing-prototypes]
    1447 | struct range arch_get_mappable_range(void)
         |              ^~~~~~~~~~~~~~~~~~~~~~~

vim +/arch_get_mappable_range +1447 arch/arm64/mm/mmu.c

  1446	
> 1447	struct range arch_get_mappable_range(void)
  1448	{
  1449		struct range memhp_range;
  1450	
  1451		/*
  1452		 * Linear mapping region is the range [PAGE_OFFSET..(PAGE_END - 1)]
  1453		 * accommodating both its ends but excluding PAGE_END. Max physical
  1454		 * range which can be mapped inside this linear mapping range, must
  1455		 * also be derived from its end points.
  1456		 */
  1457		memhp_range.start = __pa(_PAGE_OFFSET(vabits_actual));
  1458		memhp_range.end =  __pa(PAGE_END - 1);
  1459		return memhp_range;
  1460	}
  1461	

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