libperf: Adopt perf_mmap__read_done() from tools/perf

Move perf_mmap__read_init() from tools/perf to libperf and export it in
the perf/mmap.h header.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191007125344.14268-12-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/x86/tests/perf-time-to-tsc.c

@@ -142,7 +142,7 @@ int test__perf_time_to_tsc(struct test *test __maybe_unused, int subtest __maybe
 next_event:
 			perf_mmap__consume(&md->core);
 		}
-		perf_mmap__read_done(md);
+		perf_mmap__read_done(&md->core);
 	}
 
 	if (!comm1_time || !comm2_time)

tools/perf/builtin-kvm.c

@@ -794,7 +794,7 @@ static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,
 			break;
 	}
 
-	perf_mmap__read_done(md);
+	perf_mmap__read_done(&md->core);
 	return n;
 }
 

tools/perf/builtin-top.c

@@ -894,7 +894,7 @@ static void perf_top__mmap_read_idx(struct perf_top *top, int idx)
 		}
 	}
 
-	perf_mmap__read_done(md);
+	perf_mmap__read_done(&md->core);
 }
 
 static void perf_top__mmap_read(struct perf_top *top)

tools/perf/builtin-trace.c

@@ -3821,7 +3821,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 				draining = true;
 			}
 		}
-		perf_mmap__read_done(md);
+		perf_mmap__read_done(&md->core);
 	}
 
 	if (trace->nr_events == before) {

tools/perf/lib/include/perf/mmap.h

@@ -8,5 +8,6 @@ struct perf_mmap;
 
 LIBPERF_API void perf_mmap__consume(struct perf_mmap *map);
 LIBPERF_API int perf_mmap__read_init(struct perf_mmap *map);
+LIBPERF_API void perf_mmap__read_done(struct perf_mmap *map);
 
 #endif /* __LIBPERF_MMAP_H */

tools/perf/lib/libperf.map

@@ -42,6 +42,7 @@ LIBPERF_0.0.1 {
 		perf_evlist__poll;
 		perf_mmap__consume;
 		perf_mmap__read_init;
+		perf_mmap__read_done;
 	local:
 		*;
 };

tools/perf/lib/mmap.c

@@ -175,3 +175,20 @@ int perf_mmap__read_init(struct perf_mmap *map)
 
 	return __perf_mmap__read_init(map);
 }
+
+/*
+ * Mandatory for overwrite mode
+ * The direction of overwrite mode is backward.
+ * The last perf_mmap__read() will set tail to map->core.prev.
+ * Need to correct the map->core.prev to head which is the end of next read.
+ */
+void perf_mmap__read_done(struct perf_mmap *map)
+{
+	/*
+	 * Check if event was unmapped due to a POLLHUP/POLLERR.
+	 */
+	if (!refcount_read(&map->refcnt))
+		return;
+
+	map->prev = perf_mmap__read_head(map);
+}

tools/perf/tests/backward-ring-buffer.c

@@ -54,7 +54,7 @@ static int count_samples(struct evlist *evlist, int *sample_count,
 				return TEST_FAIL;
 			}
 		}
-		perf_mmap__read_done(map);
+		perf_mmap__read_done(&map->core);
 	}
 	return TEST_OK;
 }

tools/perf/tests/bpf.c

@@ -194,7 +194,7 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
 			if (type == PERF_RECORD_SAMPLE)
 				count ++;
 		}
-		perf_mmap__read_done(md);
+		perf_mmap__read_done(&md->core);
 	}
 
 	if (count != expect) {

tools/perf/tests/code-reading.c

@@ -435,7 +435,7 @@ static int process_events(struct machine *machine, struct evlist *evlist,
 			if (ret < 0)
 				return ret;
 		}
-		perf_mmap__read_done(md);
+		perf_mmap__read_done(&md->core);
 	}
 	return 0;
 }

tools/perf/tests/keep-tracking.c

@@ -49,7 +49,7 @@ static int find_comm(struct evlist *evlist, const char *comm)
 				found += 1;
 			perf_mmap__consume(&md->core);
 		}
-		perf_mmap__read_done(md);
+		perf_mmap__read_done(&md->core);
 	}
 	return found;
 }

tools/perf/tests/mmap-basic.c

@@ -142,7 +142,7 @@ int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unuse
 		nr_events[evsel->idx]++;
 		perf_mmap__consume(&md->core);
 	}
-	perf_mmap__read_done(md);
+	perf_mmap__read_done(&md->core);
 
 out_init:
 	err = 0;

tools/perf/tests/openat-syscall-tp-fields.c

@@ -124,7 +124,7 @@ int test__syscall_openat_tp_fields(struct test *test __maybe_unused, int subtest
 
 				goto out_ok;
 			}
-			perf_mmap__read_done(md);
+			perf_mmap__read_done(&md->core);
 		}
 
 		if (nr_events == before)

tools/perf/tests/perf-record.c

@@ -279,7 +279,7 @@ int test__PERF_RECORD(struct test *test __maybe_unused, int subtest __maybe_unus
 
 				perf_mmap__consume(&md->core);
 			}
-			perf_mmap__read_done(md);
+			perf_mmap__read_done(&md->core);
 		}
 
 		/*

tools/perf/tests/sw-clock.c

@@ -120,7 +120,7 @@ static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
 next_event:
 		perf_mmap__consume(&md->core);
 	}
-	perf_mmap__read_done(md);
+	perf_mmap__read_done(&md->core);
 
 out_init:
 	if ((u64) nr_samples == total_periods) {

tools/perf/tests/switch-tracking.c

@@ -280,7 +280,7 @@ static int process_events(struct evlist *evlist,
 			if (ret < 0)
 				goto out_free_nodes;
 		}
-		perf_mmap__read_done(md);
+		perf_mmap__read_done(&md->core);
 	}
 
 	events_array = calloc(cnt, sizeof(struct event_node));

tools/perf/tests/task-exit.c

@@ -127,7 +127,7 @@ int test__task_exit(struct test *test __maybe_unused, int subtest __maybe_unused
 
 		perf_mmap__consume(&md->core);
 	}
-	perf_mmap__read_done(md);
+	perf_mmap__read_done(&md->core);
 
 out_init:
 	if (!exited || !nr_exit) {

tools/perf/util/evlist.c

@@ -1822,7 +1822,7 @@ static void *perf_evlist__poll_thread(void *arg)
 				perf_mmap__consume(&map->core);
 				got_data = true;
 			}
-			perf_mmap__read_done(map);
+			perf_mmap__read_done(&map->core);
 		}
 
 		if (draining && !got_data)

tools/perf/util/mmap.c

@@ -405,20 +405,3 @@ int perf_mmap__push(struct mmap *md, void *to,
 out:
 	return rc;
 }
-
-/*
- * Mandatory for overwrite mode
- * The direction of overwrite mode is backward.
- * The last perf_mmap__read() will set tail to map->core.prev.
- * Need to correct the map->core.prev to head which is the end of next read.
- */
-void perf_mmap__read_done(struct mmap *map)
-{
-	/*
-	 * Check if event was unmapped due to a POLLHUP/POLLERR.
-	 */
-	if (!refcount_read(&map->core.refcnt))
-		return;
-
-	map->core.prev = perf_mmap__read_head(&map->core);
-}

tools/perf/util/mmap.h

@@ -54,5 +54,4 @@ int perf_mmap__push(struct mmap *md, void *to,
 
 size_t mmap__mmap_len(struct mmap *map);
 
-void perf_mmap__read_done(struct mmap *map);
 #endif /*__PERF_MMAP_H */