Hi,

I love your patch! Yet something to improve:

[auto build test ERROR on hch-configfs/for-next]
[also build test ERROR on linus/master v5.10-rc7]
[cannot apply to hnaz-linux-mm/master next-20201207]
[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/ira-weiny-intel-com/Lift-memcpy_-to-from-_page-to-core/20201208-070017
base:   git://git.infradead.org/users/hch/configfs.git for-next
config: powerpc64-randconfig-r002-20201207 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project a2f922140f5380571fb74179f2bf622b3b925697)
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 powerpc64 cross compiling tool for clang build
        # apt-get install binutils-powerpc64-linux-gnu
        # https://github.com/0day-ci/linux/commit/23e6d3f08a315c6e70fde3d63a275c91e1dcb0ee
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review ira-weiny-intel-com/Lift-memcpy_-to-from-_page-to-core/20201208-070017
        git checkout 23e6d3f08a315c6e70fde3d63a275c91e1dcb0ee
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 

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

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

   <scratch space>:223:1: note: expanded from here
   __do_outsw
   ^
   arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw'
   #define __do_outsw(p, b, n)     writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from arch/powerpc/kernel/asm-offsets.c:23:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:26:
   In file included from include/linux/kernel_stat.h:9:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:10:
   In file included from arch/powerpc/include/asm/hardirq.h:6:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:225:1: note: expanded from here
   __do_outsl
   ^
   arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl'
   #define __do_outsl(p, b, n)     writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from arch/powerpc/kernel/asm-offsets.c:23:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:22:
   In file included from include/linux/writeback.h:14:
   In file included from include/linux/blk-cgroup.h:23:
   In file included from include/linux/blkdev.h:14:
   In file included from include/linux/pagemap.h:11:
   include/linux/highmem.h:229:15: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           void *addr = kmap_local_page(page);
                        ^
   include/linux/highmem.h:229:15: note: did you mean 'kmap_to_page'?
   include/linux/highmem.h:130:28: note: 'kmap_to_page' declared here
   static inline struct page *kmap_to_page(void *addr)
                              ^
   include/linux/highmem.h:229:8: warning: incompatible integer to pointer conversion initializing 'void *' with an expression of type 'int' [-Wint-conversion]
           void *addr = kmap_local_page(page);
                 ^      ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:231:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(addr);
           ^
   include/linux/highmem.h:282:16: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           void *kaddr = kmap_local_page(page);
                         ^
   include/linux/highmem.h:282:8: warning: incompatible integer to pointer conversion initializing 'void *' with an expression of type 'int' [-Wint-conversion]
           void *kaddr = kmap_local_page(page);
                 ^       ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:284:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(kaddr);
           ^
   include/linux/highmem.h:291:16: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           void *kaddr = kmap_local_page(page);
                         ^
   include/linux/highmem.h:291:8: warning: incompatible integer to pointer conversion initializing 'void *' with an expression of type 'int' [-Wint-conversion]
           void *kaddr = kmap_local_page(page);
                 ^       ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:301:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(kaddr);
           ^
   include/linux/highmem.h:324:10: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           vfrom = kmap_local_page(from);
                   ^
   include/linux/highmem.h:324:8: warning: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion]
           vfrom = kmap_local_page(from);
                 ^ ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:325:6: warning: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion]
           vto = kmap_local_page(to);
               ^ ~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:327:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(vto);
           ^
   include/linux/highmem.h:339:10: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           vfrom = kmap_local_page(from);
                   ^
   include/linux/highmem.h:339:8: warning: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion]
           vfrom = kmap_local_page(from);
                 ^ ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:340:6: warning: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion]
           vto = kmap_local_page(to);
               ^ ~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:342:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(vto);
           ^
   In file included from arch/powerpc/kernel/asm-offsets.c:23:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:22:
   In file included from include/linux/writeback.h:14:
   In file included from include/linux/blk-cgroup.h:23:
   In file included from include/linux/blkdev.h:14:
>> include/linux/pagemap.h:1036:14: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *dst = kmap_local_page(dst_page);
                       ^
>> include/linux/pagemap.h:1036:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *dst = kmap_local_page(dst_page);
                 ^     ~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1037:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *src = kmap_local_page(src_page);
                 ^     ~~~~~~~~~~~~~~~~~~~~~~~~~
>> include/linux/pagemap.h:1039:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(src);
           ^
   include/linux/pagemap.h:1047:14: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *dst = kmap_local_page(dst_page);
                       ^
   include/linux/pagemap.h:1047:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *dst = kmap_local_page(dst_page);
                 ^     ~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1048:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *src = kmap_local_page(src_page);
                 ^     ~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1050:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(src);
           ^
   include/linux/pagemap.h:1056:15: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *from = kmap_local_page(page);
                        ^
   include/linux/pagemap.h:1056:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *from = kmap_local_page(page);
                 ^      ~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1058:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(from);
           ^
   include/linux/pagemap.h:1063:13: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *to = kmap_local_page(page);
                      ^
   include/linux/pagemap.h:1063:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *to = kmap_local_page(page);
                 ^    ~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1065:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(to);
           ^
   include/linux/pagemap.h:1070:15: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *addr = kmap_local_page(page);
                        ^
   include/linux/pagemap.h:1070:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *addr = kmap_local_page(page);
                 ^      ~~~~~~~~~~~~~~~~~~~~~
   fatal error: too many errors emitted, stopping now [-ferror-limit=]
   20 warnings and 20 errors generated.
--
   <scratch space>:223:1: note: expanded from here
   __do_outsw
   ^
   arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw'
   #define __do_outsw(p, b, n)     writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from arch/powerpc/kernel/asm-offsets.c:23:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:26:
   In file included from include/linux/kernel_stat.h:9:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:10:
   In file included from arch/powerpc/include/asm/hardirq.h:6:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:225:1: note: expanded from here
   __do_outsl
   ^
   arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl'
   #define __do_outsl(p, b, n)     writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from arch/powerpc/kernel/asm-offsets.c:23:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:22:
   In file included from include/linux/writeback.h:14:
   In file included from include/linux/blk-cgroup.h:23:
   In file included from include/linux/blkdev.h:14:
   In file included from include/linux/pagemap.h:11:
   include/linux/highmem.h:229:15: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           void *addr = kmap_local_page(page);
                        ^
   include/linux/highmem.h:229:15: note: did you mean 'kmap_to_page'?
   include/linux/highmem.h:130:28: note: 'kmap_to_page' declared here
   static inline struct page *kmap_to_page(void *addr)
                              ^
   include/linux/highmem.h:229:8: warning: incompatible integer to pointer conversion initializing 'void *' with an expression of type 'int' [-Wint-conversion]
           void *addr = kmap_local_page(page);
                 ^      ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:231:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(addr);
           ^
   include/linux/highmem.h:282:16: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           void *kaddr = kmap_local_page(page);
                         ^
   include/linux/highmem.h:282:8: warning: incompatible integer to pointer conversion initializing 'void *' with an expression of type 'int' [-Wint-conversion]
           void *kaddr = kmap_local_page(page);
                 ^       ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:284:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(kaddr);
           ^
   include/linux/highmem.h:291:16: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           void *kaddr = kmap_local_page(page);
                         ^
   include/linux/highmem.h:291:8: warning: incompatible integer to pointer conversion initializing 'void *' with an expression of type 'int' [-Wint-conversion]
           void *kaddr = kmap_local_page(page);
                 ^       ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:301:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(kaddr);
           ^
   include/linux/highmem.h:324:10: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           vfrom = kmap_local_page(from);
                   ^
   include/linux/highmem.h:324:8: warning: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion]
           vfrom = kmap_local_page(from);
                 ^ ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:325:6: warning: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion]
           vto = kmap_local_page(to);
               ^ ~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:327:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(vto);
           ^
   include/linux/highmem.h:339:10: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           vfrom = kmap_local_page(from);
                   ^
   include/linux/highmem.h:339:8: warning: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion]
           vfrom = kmap_local_page(from);
                 ^ ~~~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:340:6: warning: incompatible integer to pointer conversion assigning to 'char *' from 'int' [-Wint-conversion]
           vto = kmap_local_page(to);
               ^ ~~~~~~~~~~~~~~~~~~~
   include/linux/highmem.h:342:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(vto);
           ^
   In file included from arch/powerpc/kernel/asm-offsets.c:23:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:22:
   In file included from include/linux/writeback.h:14:
   In file included from include/linux/blk-cgroup.h:23:
   In file included from include/linux/blkdev.h:14:
>> include/linux/pagemap.h:1036:14: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *dst = kmap_local_page(dst_page);
                       ^
>> include/linux/pagemap.h:1036:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *dst = kmap_local_page(dst_page);
                 ^     ~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1037:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *src = kmap_local_page(src_page);
                 ^     ~~~~~~~~~~~~~~~~~~~~~~~~~
>> include/linux/pagemap.h:1039:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(src);
           ^
   include/linux/pagemap.h:1047:14: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *dst = kmap_local_page(dst_page);
                       ^
   include/linux/pagemap.h:1047:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *dst = kmap_local_page(dst_page);
                 ^     ~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1048:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *src = kmap_local_page(src_page);
                 ^     ~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1050:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(src);
           ^
   include/linux/pagemap.h:1056:15: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *from = kmap_local_page(page);
                        ^
   include/linux/pagemap.h:1056:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *from = kmap_local_page(page);
                 ^      ~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1058:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(from);
           ^
   include/linux/pagemap.h:1063:13: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *to = kmap_local_page(page);
                      ^
   include/linux/pagemap.h:1063:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *to = kmap_local_page(page);
                 ^    ~~~~~~~~~~~~~~~~~~~~~
   include/linux/pagemap.h:1065:2: error: implicit declaration of function 'kunmap_local' [-Werror,-Wimplicit-function-declaration]
           kunmap_local(to);
           ^
   include/linux/pagemap.h:1070:15: error: implicit declaration of function 'kmap_local_page' [-Werror,-Wimplicit-function-declaration]
           char *addr = kmap_local_page(page);
                        ^
   include/linux/pagemap.h:1070:8: warning: incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int' [-Wint-conversion]
           char *addr = kmap_local_page(page);
                 ^      ~~~~~~~~~~~~~~~~~~~~~
   fatal error: too many errors emitted, stopping now [-ferror-limit=]
   20 warnings and 20 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:1200: 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.

vim +/kmap_local_page +1036 include/linux/pagemap.h

  1031	
  1032	static inline void memcpy_page(struct page *dst_page, size_t dst_off,
  1033				       struct page *src_page, size_t src_off,
  1034				       size_t len)
  1035	{
> 1036		char *dst = kmap_local_page(dst_page);
  1037		char *src = kmap_local_page(src_page);
  1038		memcpy(dst + dst_off, src + src_off, len);
> 1039		kunmap_local(src);
  1040		kunmap_local(dst);
  1041	}
  1042	

---
0-DAY CI Kernel Test Service, Intel Corporation
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