Hi Bjorn,

I love your patch! Perhaps something to improve:

[auto build test WARNING on iommu/next]
[also build test WARNING on arm-perf/for-next/perf v5.8-rc5 next-20200715]
[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/Bjorn-Andersson/iommu-arm-smmu-Support-maintaining-bootloader-mappings/20200709-130417
base:   https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next
config: arm64-randconfig-r022-20200715 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 02946de3802d3bc65bc9f2eb9b8d4969b5a7add8)
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 arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 

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 >>):

>> drivers/iommu/arm-smmu.c:1927:5: warning: no previous prototype for function 'arm_smmu_setup_identity' [-Wmissing-prototypes]
   int arm_smmu_setup_identity(struct arm_smmu_device *smmu)
       ^
   drivers/iommu/arm-smmu.c:1927:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int arm_smmu_setup_identity(struct arm_smmu_device *smmu)
   ^
   static 
   1 warning generated.

vim +/arm_smmu_setup_identity +1927 drivers/iommu/arm-smmu.c

  1926	
> 1927	int arm_smmu_setup_identity(struct arm_smmu_device *smmu)
  1928	{
  1929		int i;
  1930	
  1931		for (i = 0; i < smmu->num_mapping_groups; i++) {
  1932			if (smmu->smrs[i].valid) {
  1933				smmu->s2crs[i].type = S2CR_TYPE_BYPASS;
  1934				smmu->s2crs[i].privcfg = S2CR_PRIVCFG_DEFAULT;
  1935				smmu->s2crs[i].cbndx = 0xff;
  1936				smmu->s2crs[i].count++;
  1937			}
  1938		}
  1939	
  1940		return 0;
  1941	}
  1942	

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