libperf: Adopt perf_mmap__read_event() from tools/perf

Move perf_mmap__read_event() 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/20191007125344.14268-13-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 2 insertions, 81 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 6e070ee9ad39..a9b189ac859b 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1811,7 +1811,7 @@ static void *perf_evlist__poll_thread(void *arg)
 
 			if (perf_mmap__read_init(&map->core))
 				continue;
-			while ((event = perf_mmap__read_event(map)) != NULL) {
+			while ((event = perf_mmap__read_event(&map->core)) != NULL) {
 				struct evsel *evsel = perf_evlist__event2evsel(evlist, event);
 
 				if (evsel && evsel->side_band.cb)
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 2dedef9b06fd..2a8bf0ab861c 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -29,83 +29,6 @@ size_t mmap__mmap_len(struct mmap *map)
 	return perf_mmap__mmap_len(&map->core);
 }
 
-/* When check_messup is true, 'end' must points to a good entry */
-static union perf_event *perf_mmap__read(struct mmap *map,
-					 u64 *startp, u64 end)
-{
-	unsigned char *data = map->core.base + page_size;
-	union perf_event *event = NULL;
-	int diff = end - *startp;
-
-	if (diff >= (int)sizeof(event->header)) {
-		size_t size;
-
-		event = (union perf_event *)&data[*startp & map->core.mask];
-		size = event->header.size;
-
-		if (size < sizeof(event->header) || diff < (int)size)
-			return NULL;
-
-		/*
-		 * Event straddles the mmap boundary -- header should always
-		 * be inside due to u64 alignment of output.
-		 */
-		if ((*startp & map->core.mask) + size != ((*startp + size) & map->core.mask)) {
-			unsigned int offset = *startp;
-			unsigned int len = min(sizeof(*event), size), cpy;
-			void *dst = map->core.event_copy;
-
-			do {
-				cpy = min(map->core.mask + 1 - (offset & map->core.mask), len);
-				memcpy(dst, &data[offset & map->core.mask], cpy);
-				offset += cpy;
-				dst += cpy;
-				len -= cpy;
-			} while (len);
-
-			event = (union perf_event *)map->core.event_copy;
-		}
-
-		*startp += size;
-	}
-
-	return event;
-}
-
-/*
- * Read event from ring buffer one by one.
- * Return one event for each call.
- *
- * Usage:
- * perf_mmap__read_init()
- * while(event = perf_mmap__read_event()) {
- *	//process the event
- *	perf_mmap__consume()
- * }
- * perf_mmap__read_done()
- */
-union perf_event *perf_mmap__read_event(struct mmap *map)
-{
-	union perf_event *event;
-
-	/*
-	 * Check if event was unmapped due to a POLLHUP/POLLERR.
-	 */
-	if (!refcount_read(&map->core.refcnt))
-		return NULL;
-
-	/* non-overwirte doesn't pause the ringbuffer */
-	if (!map->core.overwrite)
-		map->core.end = perf_mmap__read_head(&map->core);
-
-	event = perf_mmap__read(map, &map->core.start, map->core.end);
-
-	if (!map->core.overwrite)
-		map->core.prev = map->core.start;
-
-	return event;
-}
-
 int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused,
 			       struct auxtrace_mmap_params *mp __maybe_unused,
 			       void *userpg __maybe_unused,
diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index 0b15702be1a5..bee4e83f7109 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -47,8 +47,6 @@ void mmap__munmap(struct mmap *map);
 
 union perf_event *perf_mmap__read_forward(struct mmap *map);
 
-union perf_event *perf_mmap__read_event(struct mmap *map);
-
 int perf_mmap__push(struct mmap *md, void *to,
 		    int push(struct mmap *map, void *to, void *buf, size_t size));
 
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 64eec2a239d4..25118605f3f8 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -1026,7 +1026,7 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
 	if (perf_mmap__read_init(&md->core) < 0)
 		goto end;
 
-	event = perf_mmap__read_event(md);
+	event = perf_mmap__read_event(&md->core);
 	if (event != NULL) {
 		PyObject *pyevent = pyrf_event__new(event);
 		struct pyrf_event *pevent = (struct pyrf_event *)pyevent;