[powerpc:next 108/110] kernel/events/hw_breakpoint.c:216:12: warning: no previous prototype for function 'arch_reserve_bp_slot'

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
head:   30df74d67d48949da87e3a5b57c381763e8fd526
commit: 29da4f91c0c1fbda12b8a31be0d564930208c92e [108/110] powerpc/watchpoint: Don't allow concurrent perf and ptrace events
config: x86_64-allyesconfig (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 135b877874fae96b4372c8a3fbfaa8ff44ff86e3)
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        git checkout 29da4f91c0c1fbda12b8a31be0d564930208c92e
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <redacted>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

kernel/events/hw_breakpoint.c:71:12: warning: no previous prototype for function 'hw_breakpoint_weight' [-Wmissing-prototypes]
__weak int hw_breakpoint_weight(struct perf_event *bp)
^
kernel/events/hw_breakpoint.c:71:8: note: declare 'static' if the function is not intended to be used outside of this translation unit
__weak int hw_breakpoint_weight(struct perf_event *bp)
^
static

quoted

kernel/events/hw_breakpoint.c:216:12: warning: no previous prototype for function 'arch_reserve_bp_slot' [-Wmissing-prototypes]

__weak int arch_reserve_bp_slot(struct perf_event *bp)
^
kernel/events/hw_breakpoint.c:216:8: note: declare 'static' if the function is not intended to be used outside of this translation unit
__weak int arch_reserve_bp_slot(struct perf_event *bp)
^
static

quoted

kernel/events/hw_breakpoint.c:221:13: warning: no previous prototype for function 'arch_release_bp_slot' [-Wmissing-prototypes]

__weak void arch_release_bp_slot(struct perf_event *bp)
^
kernel/events/hw_breakpoint.c:221:8: note: declare 'static' if the function is not intended to be used outside of this translation unit
__weak void arch_release_bp_slot(struct perf_event *bp)
^
static
kernel/events/hw_breakpoint.c:228:13: warning: no previous prototype for function 'arch_unregister_hw_breakpoint' [-Wmissing-prototypes]
__weak void arch_unregister_hw_breakpoint(struct perf_event *bp)
^
kernel/events/hw_breakpoint.c:228:8: note: declare 'static' if the function is not intended to be used outside of this translation unit
__weak void arch_unregister_hw_breakpoint(struct perf_event *bp)
^
static
4 warnings generated.

vim +/arch_reserve_bp_slot +216 kernel/events/hw_breakpoint.c

   215	
 > 216	__weak int arch_reserve_bp_slot(struct perf_event *bp)
   217	{
   218		return 0;
   219	}
   220	
 > 221	__weak void arch_release_bp_slot(struct perf_event *bp)
   222	{
   223	}
   224	

---
0-DAY CI Kernel Test Service, Intel Corporation
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