Hi Nicholas,

I love your patch! Perhaps something to improve:

[auto build test WARNING on powerpc/next]
[also build test WARNING on v5.11-rc4 next-20210120]
[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/Nicholas-Piggin/powerpc-interrupt-wrappers/20210116-023244
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-randconfig-r035-20210120 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 22b68440e1647e16b5ee24b924986207173c02d1)
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 powerpc cross compiling tool for clang build
        # apt-get install binutils-powerpc-linux-gnu
        # https://github.com/0day-ci/linux/commit/04d5131f1545e1e992962a5339135b605eb421a5
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Nicholas-Piggin/powerpc-interrupt-wrappers/20210116-023244
        git checkout 04d5131f1545e1e992962a5339135b605eb421a5
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc 

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/powerpc/mm/book3s64/hash_utils.c:1516:30: warning: no previous prototype for function '__do_hash_fault' [-Wmissing-prototypes]
   DEFINE_INTERRUPT_HANDLER_RET(__do_hash_fault)
                                ^
   arch/powerpc/mm/book3s64/hash_utils.c:1516:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   DEFINE_INTERRUPT_HANDLER_RET(__do_hash_fault)
   ^
   arch/powerpc/include/asm/interrupt.h:150:19: note: expanded from macro 'DEFINE_INTERRUPT_HANDLER_RET'
   __visible noinstr long func(struct pt_regs *regs)                       \
                     ^
   arch/powerpc/mm/book3s64/hash_utils.c:1905:6: warning: no previous prototype for function 'hpte_insert_repeating' [-Wmissing-prototypes]
   long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
        ^
   arch/powerpc/mm/book3s64/hash_utils.c:1905:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
   ^
   static 
   2 warnings generated.


vim +/__do_hash_fault +1516 arch/powerpc/mm/book3s64/hash_utils.c

  1515	
> 1516	DEFINE_INTERRUPT_HANDLER_RET(__do_hash_fault)
  1517	{
  1518		unsigned long ea = regs->dar;
  1519		unsigned long dsisr = regs->dsisr;
  1520		unsigned long access = _PAGE_PRESENT | _PAGE_READ;
  1521		unsigned long flags = 0;
  1522		struct mm_struct *mm;
  1523		unsigned int region_id;
  1524		long err;
  1525	
  1526		region_id = get_region_id(ea);
  1527		if ((region_id == VMALLOC_REGION_ID) || (region_id == IO_REGION_ID))
  1528			mm = &init_mm;
  1529		else
  1530			mm = current->mm;
  1531	
  1532		if (dsisr & DSISR_NOHPTE)
  1533			flags |= HPTE_NOHPTE_UPDATE;
  1534	
  1535		if (dsisr & DSISR_ISSTORE)
  1536			access |= _PAGE_WRITE;
  1537		/*
  1538		 * We set _PAGE_PRIVILEGED only when
  1539		 * kernel mode access kernel space.
  1540		 *
  1541		 * _PAGE_PRIVILEGED is NOT set
  1542		 * 1) when kernel mode access user space
  1543		 * 2) user space access kernel space.
  1544		 */
  1545		access |= _PAGE_PRIVILEGED;
  1546		if (user_mode(regs) || (region_id == USER_REGION_ID))
  1547			access &= ~_PAGE_PRIVILEGED;
  1548	
  1549		if (regs->trap == 0x400)
  1550			access |= _PAGE_EXEC;
  1551	
  1552		err = hash_page_mm(mm, ea, access, regs->trap, flags);
  1553		if (unlikely(err < 0)) {
  1554			// failed to instert a hash PTE due to an hypervisor error
  1555			if (user_mode(regs)) {
  1556				if (IS_ENABLED(CONFIG_PPC_SUBPAGE_PROT) && err == -2)
  1557					_exception(SIGSEGV, regs, SEGV_ACCERR, ea);
  1558				else
  1559					_exception(SIGBUS, regs, BUS_ADRERR, ea);
  1560			} else {
  1561				bad_page_fault(regs, SIGBUS);
  1562			}
  1563			err = 0;
  1564		}
  1565	
  1566		return err;
  1567	}
  1568	

---
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