libperf: Adopt perf_counts_values__scale() from tools/perf/util

Move perf_counts_values__scale() from tools/perf/util to tools/lib/perf
so that it can be used with libperf.

Committer notes:

As noted by Jiri, use __s8 instead of s8 on the exported function.

Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211109085831.3770594-2-nakamura.shun@fujitsu.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/perf/evsel.c

@@ -431,3 +431,22 @@ void perf_evsel__free_id(struct perf_evsel *evsel)
 	zfree(&evsel->id);
 	evsel->ids = 0;
 }
+
+void perf_counts_values__scale(struct perf_counts_values *count,
+			       bool scale, __s8 *pscaled)
+{
+	s8 scaled = 0;
+
+	if (scale) {
+		if (count->run == 0) {
+			scaled = -1;
+			count->val = 0;
+		} else if (count->run < count->ena) {
+			scaled = 1;
+			count->val = (u64)((double)count->val * count->ena / count->run);
+		}
+	}
+
+	if (pscaled)
+		*pscaled = scaled;
+}

tools/lib/perf/include/perf/evsel.h

@@ -4,6 +4,8 @@
 
 #include <stdint.h>
 #include <perf/core.h>
+#include <stdbool.h>
+#include <linux/types.h>
 
 struct perf_evsel;
 struct perf_event_attr;
@@ -39,5 +41,7 @@ LIBPERF_API int perf_evsel__disable_cpu(struct perf_evsel *evsel, int cpu);
 LIBPERF_API struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel);
 LIBPERF_API struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel);
 LIBPERF_API struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel);
+LIBPERF_API void perf_counts_values__scale(struct perf_counts_values *count,
+					   bool scale, __s8 *pscaled);
 
 #endif /* __LIBPERF_EVSEL_H */

tools/lib/perf/libperf.map

@@ -50,6 +50,7 @@ LIBPERF_0.0.1 {
 		perf_mmap__read_init;
 		perf_mmap__read_done;
 		perf_mmap__read_event;
+		perf_counts_values__scale;
 	local:
 		*;
 };

tools/perf/util/evsel.c

@@ -1476,25 +1476,6 @@ void evsel__compute_deltas(struct evsel *evsel, int cpu, int thread,
 	count->run = count->run - tmp.run;
 }
 
-void perf_counts_values__scale(struct perf_counts_values *count,
-			       bool scale, s8 *pscaled)
-{
-	s8 scaled = 0;
-
-	if (scale) {
-		if (count->run == 0) {
-			scaled = -1;
-			count->val = 0;
-		} else if (count->run < count->ena) {
-			scaled = 1;
-			count->val = (u64)((double) count->val * count->ena / count->run);
-		}
-	}
-
-	if (pscaled)
-		*pscaled = scaled;
-}
-
 static int evsel__read_one(struct evsel *evsel, int cpu, int thread)
 {
 	struct perf_counts_values *count = perf_counts(evsel->counts, cpu, thread);

tools/perf/util/evsel.h

@@ -195,9 +195,6 @@ static inline int evsel__nr_cpus(struct evsel *evsel)
 	return evsel__cpus(evsel)->nr;
 }
 
-void perf_counts_values__scale(struct perf_counts_values *count,
-			       bool scale, s8 *pscaled);
-
 void evsel__compute_deltas(struct evsel *evsel, int cpu, int thread,
 			   struct perf_counts_values *count);