tree:   https://github.com/intel/tdx.git guest
head:   12f4800ff5dbe89a642744796008f89f23b2e446
commit: 200e6caad3e4ac89bb2097d4d21425eabac46eea [122/136] swiotlb: Split up single swiotlb lock
config: x86_64-buildonly-randconfig-r006-20211019 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 92a0389b0425a9535a99a0ce13ba0eeda2bce7ad)
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/200e6caad3e4ac89bb2097d4d21425eabac46eea
        git remote add intel-tdx https://github.com/intel/tdx.git
        git fetch --no-tags intel-tdx guest
        git checkout 200e6caad3e4ac89bb2097d4d21425eabac46eea
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=x86_64 

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 >>):

>> kernel/dma/swiotlb.c:540:28: error: unused function 'area_end' [-Werror,-Wunused-function]
   static inline unsigned int area_end(struct io_tlb_mem *mem, int aindex)
                              ^
   1 error generated.


vim +/area_end +540 kernel/dma/swiotlb.c

   539	
 > 540	static inline unsigned int area_end(struct io_tlb_mem *mem, int aindex)
   541	{
   542		return area_start(aindex) + area_nslabs(mem);
   543	}
   544	

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