tree:   https://github.com/intel/tdx.git guest
head:   44e41606b85b08fad5378c876547f8557f835cf6
commit: bf7442e234b1f75005d763d9fce1ae5dfd9d57eb [39/113] x86/mm: Move force_dma_unencrypted() to common code
config: x86_64-randconfig-a001-20210829 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 4e1a164d7bd53653f79decc121afe784d2fde0a7)
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/intel/tdx/commit/bf7442e234b1f75005d763d9fce1ae5dfd9d57eb
        git remote add intel-tdx https://github.com/intel/tdx.git
        git fetch --no-tags intel-tdx guest
        git checkout bf7442e234b1f75005d763d9fce1ae5dfd9d57eb
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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/x86/mm/mem_encrypt_common.c:14:6: warning: no previous prototype for function 'force_dma_unencrypted' [-Wmissing-prototypes]
   bool force_dma_unencrypted(struct device *dev)
        ^
   arch/x86/mm/mem_encrypt_common.c:14:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   bool force_dma_unencrypted(struct device *dev)
   ^
   static 
   1 warning generated.


vim +/force_dma_unencrypted +14 arch/x86/mm/mem_encrypt_common.c

    12	
    13	/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
  > 14	bool force_dma_unencrypted(struct device *dev)

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