tree:   https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git memory-models/rm-discontig/v1
head:   828beb6f6f782ea80e1dbb3dd59cd38281821abb
commit: c0ee646677c86d6a9b19669046941aa9417d2072 [8/9] mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
config: openrisc-randconfig-s032-20210526 (attached as .config)
compiler: or1k-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-341-g8af24329-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git/commit/?id=c0ee646677c86d6a9b19669046941aa9417d2072
        git remote add rppt https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git
        git fetch --no-tags rppt memory-models/rm-discontig/v1
        git checkout c0ee646677c86d6a9b19669046941aa9417d2072
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=openrisc 

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 >>):

   arch/openrisc/mm/init.c: In function 'mem_init':
>> arch/openrisc/mm/init.c:201:2: error: 'max_mapnr' undeclared (first use in this function)
     201 |  max_mapnr = max_low_pfn;
         |  ^~~~~~~~~
   arch/openrisc/mm/init.c:201:2: note: each undeclared identifier is reported only once for each function it appears in
--
   In file included from arch/openrisc/include/asm/processor.h:19,
                    from arch/openrisc/include/asm/thread_info.h:22,
                    from include/linux/thread_info.h:59,
                    from include/asm-generic/current.h:5,
                    from ./arch/openrisc/include/generated/asm/current.h:1,
                    from include/linux/sched.h:12,
                    from include/linux/blkdev.h:5,
                    from include/linux/blk-mq.h:5,
                    from drivers/block/aoe/aoeblk.c:9:
   drivers/block/aoe/aoeblk.c: In function 'aoeblk_open':
>> arch/openrisc/include/asm/page.h:83:42: error: 'max_mapnr' undeclared (first use in this function); did you mean 'set_max_mapnr'?
      83 | #define pfn_valid(pfn)          ((pfn) < max_mapnr)
         |                                          ^~~~~~~~~
   arch/openrisc/include/asm/page.h:85:33: note: in expansion of macro 'pfn_valid'
      85 | #define virt_addr_valid(kaddr) (pfn_valid(virt_to_pfn(kaddr)))
         |                                 ^~~~~~~~~
   drivers/block/aoe/aoeblk.c:225:7: note: in expansion of macro 'virt_addr_valid'
     225 |  if (!virt_addr_valid(d)) {
         |       ^~~~~~~~~~~~~~~
   arch/openrisc/include/asm/page.h:83:42: note: each undeclared identifier is reported only once for each function it appears in
      83 | #define pfn_valid(pfn)          ((pfn) < max_mapnr)
         |                                          ^~~~~~~~~
   arch/openrisc/include/asm/page.h:85:33: note: in expansion of macro 'pfn_valid'
      85 | #define virt_addr_valid(kaddr) (pfn_valid(virt_to_pfn(kaddr)))
         |                                 ^~~~~~~~~
   drivers/block/aoe/aoeblk.c:225:7: note: in expansion of macro 'virt_addr_valid'
     225 |  if (!virt_addr_valid(d)) {
         |       ^~~~~~~~~~~~~~~


vim +/max_mapnr +201 arch/openrisc/mm/init.c

61e85e367535a7 Jonas Bonn   2011-06-04  196  
61e85e367535a7 Jonas Bonn   2011-06-04  197  void __init mem_init(void)
61e85e367535a7 Jonas Bonn   2011-06-04  198  {
2e1c958de4e22b Julia Lawall 2011-08-02  199  	BUG_ON(!mem_map);
61e85e367535a7 Jonas Bonn   2011-06-04  200  
1173db12bf145a Jiang Liu    2013-07-03 @201  	max_mapnr = max_low_pfn;

:::::: The code@line 201 was first introduced by commit
:::::: 1173db12bf145a0d0c6a2716e861de2fafde0522 mm/openrisc: prepare for removing num_physpages and simplify mem_init()

:::::: TO: Jiang Liu <liuj97@gmail.com>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>

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