Hi Huacai,

I love your patch! Perhaps something to improve:

[auto build test WARNING on soc/for-next]
[also build test WARNING on linus/master v6.0-rc7 next-20220928]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Huacai-Chen/LoongArch-Support-access-filter-to-dev-mem-interface/20220929-101532
base:   https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git for-next
config: loongarch-allyesconfig
compiler: loongarch64-linux-gcc (GCC) 12.1.0
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-lab-lkp/linux/commit/ebb5f48a499f12b42fe885735d3678914667fb73
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Huacai-Chen/LoongArch-Support-access-filter-to-dev-mem-interface/20220929-101532
        git checkout ebb5f48a499f12b42fe885735d3678914667fb73
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash arch/loongarch/

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

All warnings (new ones prefixed by >>):

>> arch/loongarch/mm/mmap.c:125:5: warning: no previous prototype for 'valid_phys_addr_range' [-Wmissing-prototypes]
     125 | int valid_phys_addr_range(phys_addr_t addr, size_t size)
         |     ^~~~~~~~~~~~~~~~~~~~~
>> arch/loongarch/mm/mmap.c:143:5: warning: no previous prototype for 'valid_mmap_phys_addr_range' [-Wmissing-prototypes]
     143 | int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/valid_phys_addr_range +125 arch/loongarch/mm/mmap.c

   120	
   121	/*
   122	 * You really shouldn't be using read() or write() on /dev/mem.  This might go
   123	 * away in the future.
   124	 */
 > 125	int valid_phys_addr_range(phys_addr_t addr, size_t size)
   126	{
   127		/*
   128		 * Check whether addr is covered by a memory region without the
   129		 * MEMBLOCK_NOMAP attribute, and whether that region covers the
   130		 * entire range. In theory, this could lead to false negatives
   131		 * if the range is covered by distinct but adjacent memory regions
   132		 * that only differ in other attributes. However, few of such
   133		 * attributes have been defined, and it is debatable whether it
   134		 * follows that /dev/mem read() calls should be able traverse
   135		 * such boundaries.
   136		 */
   137		return memblock_is_region_memory(addr, size) && memblock_is_map_memory(addr);
   138	}
   139	
   140	/*
   141	 * Do not allow /dev/mem mappings beyond the supported physical range.
   142	 */
 > 143	int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)

-- 
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https://01.org/lkp