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

From: kernel test robot
Date: Fri Jul 23 2021 - 04:26:59 EST

tree: 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 ( 9625ca5b602616b2f5584e8a49ba93c52c141e40)
reproduce (this is a W=1 build):
wget -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install powerpc64 cross compiling tool for clang build
# apt-get install binutils-powerpc64-linux-gnu
git remote add linus
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)
1 error generated.

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

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

0-DAY CI Kernel Test Service, Intel Corporation

Attachment: .config.gz
Description: application/gzip