Hi David,

I love your patch! Perhaps something to improve:

[auto build test WARNING on next-20200909]
[cannot apply to mmotm/master hnaz-linux-mm/master xen-tip/linux-next powerpc/next linus/master v5.9-rc4 v5.9-rc3 v5.9-rc2 v5.9-rc4]
[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/David-Hildenbrand/mm-memory_hotplug-selective-merging-of-system-ram-resources/20200910-171630
base:    7204eaa2c1f509066486f488c9dcb065d7484494
:::::: branch date: 9 hours ago
:::::: commit date: 9 hours ago
config: powerpc-randconfig-r011-20200909 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 0a5dc7effb191eff740e0e7ae7bd8e1f6bdb3ad9)
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
        # install powerpc cross compiling tool for clang build
        # apt-get install binutils-powerpc-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc 

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

All warnings (new ones prefixed by >>):

   In file included from arch/powerpc/kernel/asm-offsets.c:14:
   In file included from include/linux/compat.h:17:
   In file included from include/linux/fs.h:15:
   In file included from include/linux/radix-tree.h:18:
   In file included from include/linux/xarray.h:14:
   In file included from include/linux/gfp.h:6:
   In file included from include/linux/mmzone.h:853:
   include/linux/memory_hotplug.h:354:55: error: unknown type name 'mhp_t'
   extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
                                                         ^
   include/linux/memory_hotplug.h:355:53: error: unknown type name 'mhp_t'
   extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
                                                       ^
   include/linux/memory_hotplug.h:357:11: error: unknown type name 'mhp_t'
                                  mhp_t mhp_flags);
                                  ^
   include/linux/memory_hotplug.h:360:10: error: unknown type name 'mhp_t'
                                        mhp_t mhp_flags);
                                        ^
   In file included from arch/powerpc/kernel/asm-offsets.c:21:

quoted

include/linux/mman.h:137:9: warning: division by zero is undefined [-Wdivision-by-zero]

                  _calc_vm_trans(flags, MAP_LOCKED,     VM_LOCKED    ) |
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/mman.h:115:21: note: expanded from macro '_calc_vm_trans'
      : ((x) & (bit1)) / ((bit1) / (bit2))))
                       ^ ~~~~~~~~~~~~~~~~~
   include/linux/mman.h:138:9: warning: division by zero is undefined [-Wdivision-by-zero]
                  _calc_vm_trans(flags, MAP_SYNC,       VM_SYNC      );
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/mman.h:115:21: note: expanded from macro '_calc_vm_trans'
      : ((x) & (bit1)) / ((bit1) / (bit2))))
                       ^ ~~~~~~~~~~~~~~~~~
   2 warnings and 4 errors generated.
   make[2]: *** [scripts/Makefile.build:117: arch/powerpc/kernel/asm-offsets.s] Error 1
   make[2]: Target '__build' not remade because of errors.
   make[1]: *** [Makefile:1196: prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:185: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.

# https://github.com/0day-ci/linux/commit/d88270d1c0783a7f99f24a85692be90fd2ae0d7d
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review David-Hildenbrand/mm-memory_hotplug-selective-merging-of-system-ram-resources/20200910-171630
git checkout d88270d1c0783a7f99f24a85692be90fd2ae0d7d
vim +137 include/linux/mman.h

^1da177e4c3f41 Linus Torvalds  2005-04-16  128  
^1da177e4c3f41 Linus Torvalds  2005-04-16  129  /*
^1da177e4c3f41 Linus Torvalds  2005-04-16  130   * Combine the mmap "flags" argument into "vm_flags" used internally.
^1da177e4c3f41 Linus Torvalds  2005-04-16  131   */
^1da177e4c3f41 Linus Torvalds  2005-04-16  132  static inline unsigned long
^1da177e4c3f41 Linus Torvalds  2005-04-16  133  calc_vm_flag_bits(unsigned long flags)
^1da177e4c3f41 Linus Torvalds  2005-04-16  134  {
^1da177e4c3f41 Linus Torvalds  2005-04-16  135  	return _calc_vm_trans(flags, MAP_GROWSDOWN,  VM_GROWSDOWN ) |
^1da177e4c3f41 Linus Torvalds  2005-04-16  136  	       _calc_vm_trans(flags, MAP_DENYWRITE,  VM_DENYWRITE ) |
b6fb293f2497a9 Jan Kara        2017-11-01 @137  	       _calc_vm_trans(flags, MAP_LOCKED,     VM_LOCKED    ) |
b6fb293f2497a9 Jan Kara        2017-11-01  138  	       _calc_vm_trans(flags, MAP_SYNC,	     VM_SYNC      );
^1da177e4c3f41 Linus Torvalds  2005-04-16  139  }
00619bcc44d6b7 Jerome Marchand 2013-11-12  140  

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