perf build: Switch libpfm4 to opt-out rather than opt-in

If libpfm4 passes the feature test, it would be nice to have it
enabled rather than also requiring the LIBPFM4=1 build flag.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andres Freund <andres@anarazel.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pavithra Gurushankar <gpavithrasha@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Roberto Sassu <roberto.sassu@huawei.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230311065753.3012826-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Makefile.config

@@ -1138,7 +1138,7 @@ ifdef LIBCLANGLLVM
   endif
 endif
 
-ifdef LIBPFM4
+ifndef NO_LIBPFM4
   $(call feature_check,libpfm4)
   ifeq ($(feature-libpfm4), 1)
     CFLAGS += -DHAVE_LIBPFM
@@ -1147,7 +1147,6 @@ ifdef LIBPFM4
     $(call detected,CONFIG_LIBPFM4)
   else
     msg := $(warning libpfm4 not found, disables libpfm4 support. Please install libpfm4-dev);
-    NO_LIBPFM4 := 1
   endif
 endif
 

tools/perf/Makefile.perf

@@ -122,7 +122,7 @@ include ../scripts/utilities.mak
 # generated from the kernel .tbl or unistd.h files and use, if available, libaudit
 # for doing the conversions to/from strings/id.
 #
-# Define LIBPFM4 to enable libpfm4 events extension.
+# Define NO_LIBPFM4 to disable libpfm4 events extension.
 #
 # Define NO_LIBDEBUGINFOD if you do not want support debuginfod
 #

tools/perf/tests/make

@@ -94,7 +94,7 @@ make_with_coresight := CORESIGHT=1
 make_no_sdt	    := NO_SDT=1
 make_no_syscall_tbl := NO_SYSCALL_TABLE=1
 make_with_clangllvm := LIBCLANGLLVM=1
-make_with_libpfm4   := LIBPFM4=1
+make_no_libpfm4     := NO_LIBPFM4=1
 make_with_gtk2      := GTK2=1
 make_tags           := tags
 make_cscope         := cscope
@@ -160,7 +160,7 @@ run += make_no_syscall_tbl
 run += make_with_babeltrace
 run += make_with_coresight
 run += make_with_clangllvm
-run += make_with_libpfm4
+run += make_no_libpfm4
 run += make_help
 run += make_doc
 run += make_perf_o