tree:   https://github.com/rgushchin/linux.git fix_vmstats
head:   4ec858b5201ae067607e82706b36588631c1b990
commit: 938dda772d9d05074bfe1baa0dc18873fbf4fedb [21/221] include/asm-generic/5level-fixup.h: fix variable 'p4d' set but not used
config: parisc-c3000_defconfig (attached as .config)
compiler: hppa-linux-gcc (GCC) 7.4.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout 938dda772d9d05074bfe1baa0dc18873fbf4fedb
        # save the attached .config to linux build tree
        GCC_VERSION=7.4.0 make.cross ARCH=parisc 

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

All error/warnings (new ones prefixed by >>):

   In file included from include/asm-generic/4level-fixup.h:38:0,
                    from arch/parisc/include/asm/pgtable.h:5,
                    from arch/parisc/include/asm/io.h:6,
                    from include/linux/io.h:13,
                    from sound/core/pcm_memory.c:7:
>> include/asm-generic/5level-fixup.h:14:18: error: unknown type name 'pgd_t'; did you mean 'pid_t'?
    #define p4d_t    pgd_t
                     ^
>> include/asm-generic/5level-fixup.h:24:28: note: in expansion of macro 'p4d_t'
    static inline int p4d_none(p4d_t p4d)
                               ^~~~~
>> include/asm-generic/5level-fixup.h:14:18: error: unknown type name 'pgd_t'; did you mean 'pid_t'?
    #define p4d_t    pgd_t
                     ^
   include/asm-generic/5level-fixup.h:29:27: note: in expansion of macro 'p4d_t'
    static inline int p4d_bad(p4d_t p4d)
                              ^~~~~
>> include/asm-generic/5level-fixup.h:14:18: error: unknown type name 'pgd_t'; did you mean 'pid_t'?
    #define p4d_t    pgd_t
                     ^
   include/asm-generic/5level-fixup.h:34:31: note: in expansion of macro 'p4d_t'
    static inline int p4d_present(p4d_t p4d)
                                  ^~~~~
   In file included from arch/parisc/include/asm/pgtable.h:583:0,
                    from arch/parisc/include/asm/io.h:6,
                    from include/linux/io.h:13,
                    from sound/core/pcm_memory.c:7:
   include/asm-generic/pgtable.h: In function 'p4d_none_or_clear_bad':
>> include/asm-generic/pgtable.h:578:6: error: implicit declaration of function 'p4d_none'; did you mean 'pgd_none'? [-Werror=implicit-function-declaration]
     if (p4d_none(*p4d))
         ^~~~~~~~
         pgd_none
   In file included from include/linux/init.h:5:0,
                    from include/linux/io.h:10,
                    from sound/core/pcm_memory.c:7:
>> include/asm-generic/pgtable.h:580:15: error: implicit declaration of function 'p4d_bad'; did you mean 'pgd_bad'? [-Werror=implicit-function-declaration]
     if (unlikely(p4d_bad(*p4d))) {
                  ^
   include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
    # define unlikely(x) __builtin_expect(!!(x), 0)
                                             ^
   cc1: some warnings being treated as errors

vim +14 include/asm-generic/5level-fixup.h

505a60e225606f Kirill A. Shutemov 2017-03-09  13  
505a60e225606f Kirill A. Shutemov 2017-03-09 @14  #define p4d_t				pgd_t
505a60e225606f Kirill A. Shutemov 2017-03-09  15  
505a60e225606f Kirill A. Shutemov 2017-03-09  16  #define pud_alloc(mm, p4d, address) \
505a60e225606f Kirill A. Shutemov 2017-03-09  17  	((unlikely(pgd_none(*(p4d))) && __pud_alloc(mm, p4d, address)) ? \
505a60e225606f Kirill A. Shutemov 2017-03-09  18  		NULL : pud_offset(p4d, address))
505a60e225606f Kirill A. Shutemov 2017-03-09  19  
505a60e225606f Kirill A. Shutemov 2017-03-09  20  #define p4d_alloc(mm, pgd, address)	(pgd)
505a60e225606f Kirill A. Shutemov 2017-03-09  21  #define p4d_offset(pgd, start)		(pgd)
938dda772d9d05 Qian Cai           2019-08-09  22  
938dda772d9d05 Qian Cai           2019-08-09  23  #ifndef __ASSEMBLY__
938dda772d9d05 Qian Cai           2019-08-09 @24  static inline int p4d_none(p4d_t p4d)
938dda772d9d05 Qian Cai           2019-08-09  25  {
938dda772d9d05 Qian Cai           2019-08-09  26  	return 0;
938dda772d9d05 Qian Cai           2019-08-09  27  }
938dda772d9d05 Qian Cai           2019-08-09  28  

:::::: The code at line 14 was first introduced by commit
:::::: 505a60e225606fbd3d2eadc31ff793d939ba66f1 asm-generic: introduce 5level-fixup.h

:::::: TO: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>

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