tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   889bab4c367a0ef58208fd80fafa74bb6e2dca26
commit: de5473936808627fa98c3d2e8e3fa3076338f601 [11572/11714] mbox: add polarfire soc system controller mailbox
config: microblaze-randconfig-r012-20210621 (attached as .config)
compiler: microblaze-linux-gcc (GCC) 9.3.0
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://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=de5473936808627fa98c3d2e8e3fa3076338f601
        git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
        git fetch --no-tags linux-next master
        git checkout de5473936808627fa98c3d2e8e3fa3076338f601
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=microblaze 

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 >>):

   In file included from drivers/mailbox/mailbox-mpfs.c:19:
>> include/soc/microchip/mpfs.h:49:29: warning: no previous prototype for 'mpfs_sys_controller_get' [-Wmissing-prototypes]
      49 | struct mpfs_sys_controller *mpfs_sys_controller_get(struct device_node *mailbox_node)
         |                             ^~~~~~~~~~~~~~~~~~~~~~~
   In file included from include/linux/bitops.h:6,
                    from include/linux/kernel.h:12,
                    from include/asm-generic/bug.h:20,
                    from ./arch/microblaze/include/generated/asm/bug.h:1,
                    from include/linux/bug.h:5,
                    from include/linux/io.h:11,
                    from drivers/mailbox/mailbox-mpfs.c:11:
   drivers/mailbox/mailbox-mpfs.c: In function 'mpfs_mbox_send_data':
>> include/linux/bits.h:36:11: warning: right shift count >= width of type [-Wshift-count-overflow]
      36 |   (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
         |           ^~
   include/linux/bits.h:38:31: note: in expansion of macro '__GENMASK'
      38 |  (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
         |                               ^~~~~~~~~
   drivers/mailbox/mailbox-mpfs.c:42:23: note: in expansion of macro 'GENMASK'
      42 | #define SCB_CTRL_MASK GENMASK(SCB_CTRL_POS + SCB_MASK_WIDTH, SCB_CTRL_POS)
         |                       ^~~~~~~
   drivers/mailbox/mailbox-mpfs.c:122:43: note: in expansion of macro 'SCB_CTRL_MASK'
     122 |  tx_trigger = (opt_sel << SCB_CTRL_POS) & SCB_CTRL_MASK;
         |                                           ^~~~~~~~~~~~~
   In file included from drivers/mailbox/mailbox-mpfs.c:19:
   At top level:
   include/soc/microchip/mpfs.h:43:12: warning: 'mpfs_blocking_transaction' defined but not used [-Wunused-function]
      43 | static int mpfs_blocking_transaction(struct mpfs_sys_controller *mpfs_client, void *msg,
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~


vim +/mpfs_sys_controller_get +49 include/soc/microchip/mpfs.h

    48	
  > 49	struct mpfs_sys_controller *mpfs_sys_controller_get(struct device_node *mailbox_node)
    50	{
    51		return NULL;
    52	}
    53	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org