tree:   https://git.kernel.org/pub/scm/linux/kernel/git/djiang/linux.git cxl-security
head:   3b2ea8468d5dbe2e7b61dcd86cc3aeadfe766d07
commit: d8fab77dd9512ae56e653afddbef9351da206679 [1/19] memregion: Add cpu_cache_invalidate_memregion() interface
config: x86_64-allyesconfig
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/djiang/linux.git/commit/?id=d8fab77dd9512ae56e653afddbef9351da206679
        git remote add djiang https://git.kernel.org/pub/scm/linux/kernel/git/djiang/linux.git
        git fetch --no-tags djiang cxl-security
        git checkout d8fab77dd9512ae56e653afddbef9351da206679
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/mm/pat/

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/x86/mm/pat/set_memory.c:334:6: warning: no previous prototype for 'cpu_cache_has_invalidate_memregion' [-Wmissing-prototypes]
     334 | bool cpu_cache_has_invalidate_memregion(void)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/x86/mm/pat/set_memory.c:340:5: warning: no previous prototype for 'cpu_cache_invalidate_memregion' [-Wmissing-prototypes]
     340 | int cpu_cache_invalidate_memregion(int res_desc)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/cpu_cache_has_invalidate_memregion +334 arch/x86/mm/pat/set_memory.c

   332	
   333	#ifdef CONFIG_ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
 > 334	bool cpu_cache_has_invalidate_memregion(void)
   335	{
   336		return !cpu_feature_enabled(X86_FEATURE_HYPERVISOR);
   337	}
   338	EXPORT_SYMBOL_GPL(cpu_cache_has_invalidate_memregion);
   339	
 > 340	int cpu_cache_invalidate_memregion(int res_desc)
   341	{
   342		wbinvd_on_all_cpus();
   343		return 0;
   344	}
   345	EXPORT_SYMBOL_GPL(cpu_cache_invalidate_memregion);
   346	#endif
   347	

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