arch/powerpc/platforms/microwatt/rng.c:17:5: error: no previous prototype for function 'microwatt_get_random_darn'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   8baef6386baaefb776bdd09b5c7630cf057c51c6
commit: c25769fddaec13509b6cdc7ad17458f239c4cee7 powerpc/microwatt: Add support for hardware random number generator
date:   5 weeks ago
config: powerpc64-randconfig-r033-20210723 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 9625ca5b602616b2f5584e8a49ba93c52c141e40)
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 powerpc64 cross compiling tool for clang build
        # apt-get install binutils-powerpc64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c25769fddaec13509b6cdc7ad17458f239c4cee7
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout c25769fddaec13509b6cdc7ad17458f239c4cee7
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

>> arch/powerpc/platforms/microwatt/rng.c:17:5: error: no previous prototype for function 'microwatt_get_random_darn' [-Werror,-Wmissing-prototypes]
   int microwatt_get_random_darn(unsigned long *v)
       ^
   arch/powerpc/platforms/microwatt/rng.c:17:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int microwatt_get_random_darn(unsigned long *v)
   ^
   static 
   1 error generated.


vim +/microwatt_get_random_darn +17 arch/powerpc/platforms/microwatt/rng.c

    16	
  > 17	int microwatt_get_random_darn(unsigned long *v)
    18	{
    19		unsigned long val;
    20	
    21		/* Using DARN with L=1 - 64-bit conditioned random number */
    22		asm volatile(PPC_DARN(%0, 1) : "=r"(val));
    23	
    24		if (val == DARN_ERR)
    25			return 0;
    26	
    27		*v = val;
    28	
    29		return 1;
    30	}
    31	

---
0-DAY CI Kernel Test Service, Intel Corporation
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Attachment: .config.gz
Description: application/gzip