[linuxppc:next-test 126/140] arch/powerpc/perf/core-book3s.c:2455:6: warning: no previous prototype for 'power_pmu_wants_prompt_pmi'

[kernel test robot <lkp@intel.com>]

tree:   https://github.com/linuxppc/linux next-test
head:   9c4c79c450672b18889a42e6b16a0254ed9721e0
commit: 5a7745b96f43c69f9b4875bcf516a0341acbc3fb [126/140] powerpc/64s/perf: add power_pmu_wants_prompt_pmi to say whether perf wants PMIs to be soft-NMI
config: powerpc-allyesconfig (https://download.01.org/0day-ci/archive/20211222/202112220137.X16y07Dp-lkp@intel.com/config)
compiler: powerpc-linux-gcc (GCC) 11.2.0
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://github.com/linuxppc/linux/commit/5a7745b96f43c69f9b4875bcf516a0341acbc3fb
        git remote add linuxppc https://github.com/linuxppc/linux
        git fetch --no-tags linuxppc next-test
        git checkout 5a7745b96f43c69f9b4875bcf516a0341acbc3fb
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/perf/

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/perf/core-book3s.c:2455:6: warning: no previous prototype for 'power_pmu_wants_prompt_pmi' [-Wmissing-prototypes]
    2455 | bool power_pmu_wants_prompt_pmi(void)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/power_pmu_wants_prompt_pmi +2455 arch/powerpc/perf/core-book3s.c

  2440	
  2441	/*
  2442	 * If the perf subsystem wants performance monitor interrupts as soon as
  2443	 * possible (e.g., to sample the instruction address and stack chain),
  2444	 * this should return true. The IRQ masking code can then enable MSR[EE]
  2445	 * in some places (e.g., interrupt handlers) that allows PMI interrupts
  2446	 * though to improve accuracy of profiles, at the cost of some performance.
  2447	 *
  2448	 * The PMU counters can be enabled by other means (e.g., sysfs raw SPR
  2449	 * access), but in that case there is no need for prompt PMI handling.
  2450	 *
  2451	 * This currently returns true if any perf counter is being used. It
  2452	 * could possibly return false if only events are being counted rather than
  2453	 * samples being taken, but for now this is good enough.
  2454	 */
> 2455	bool power_pmu_wants_prompt_pmi(void)
  2456	{
  2457		struct cpu_hw_events *cpuhw;
  2458	
  2459		/*
  2460		 * This could simply test local_paca->pmcregs_in_use if that were not
  2461		 * under ifdef KVM.
  2462		 */
  2463	
  2464		if (!ppmu)
  2465			return false;
  2466	
  2467		cpuhw = this_cpu_ptr(&cpu_hw_events);
  2468		return cpuhw->n_events;
  2469	}
  2470	

---
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