[tip:perf/core] perf tools: Add mechanic to synthesise CoreSight trace packets

[tip-bot for Mathieu Poirier]

Commit-ID:  38ddaba83c00633c37432663a19faff7c42bc4b7
Gitweb:     https://git.kernel.org/tip/38ddaba83c00633c37432663a19faff7c42bc4b7
Author:     Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
AuthorDate: Wed, 17 Jan 2018 10:52:18 -0700
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 23 Jan 2018 09:51:49 -0300

perf tools: Add mechanic to synthesise CoreSight trace packets

Once decoded from trace packets information on trace range needs
to be communicated to the perf synthesis infrastructure so that it
is available to the perf tools built-in rendering tools and scripts.

Co-authored-by: Tor Jeremiassen <tor@xxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Kim Phillips <kim.phillips@xxxxxxx>
Cc: Mike Leach <mike.leach@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Suzuki Poulouse <suzuki.poulose@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1516211539-5166-10-git-send-email-mathieu.poirier@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/cs-etm.c | 168 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 168 insertions(+)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 407095a..b9f0a53 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -453,6 +453,157 @@ static void  cs_etm__set_pid_tid_cpu(struct cs_etm_auxtrace *etm,
 	}
 }
 
+/*
+ * The cs etm packet encodes an instruction range between a branch target
+ * and the next taken branch. Generate sample accordingly.
+ */
+static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq,
+				       struct cs_etm_packet *packet)
+{
+	int ret = 0;
+	struct cs_etm_auxtrace *etm = etmq->etm;
+	struct perf_sample sample = {.ip = 0,};
+	union perf_event *event = etmq->event_buf;
+	u64 start_addr = packet->start_addr;
+	u64 end_addr = packet->end_addr;
+
+	event->sample.header.type = PERF_RECORD_SAMPLE;
+	event->sample.header.misc = PERF_RECORD_MISC_USER;
+	event->sample.header.size = sizeof(struct perf_event_header);
+
+	sample.ip = start_addr;
+	sample.pid = etmq->pid;
+	sample.tid = etmq->tid;
+	sample.addr = end_addr;
+	sample.id = etmq->etm->branches_id;
+	sample.stream_id = etmq->etm->branches_id;
+	sample.period = 1;
+	sample.cpu = packet->cpu;
+	sample.flags = 0;
+	sample.cpumode = PERF_RECORD_MISC_USER;
+
+	ret = perf_session__deliver_synth_event(etm->session, event, &sample);
+
+	if (ret)
+		pr_err(
+		"CS ETM Trace: failed to deliver instruction event, error %d\n",
+		ret);
+
+	return ret;
+}
+
+struct cs_etm_synth {
+	struct perf_tool dummy_tool;
+	struct perf_session *session;
+};
+
+static int cs_etm__event_synth(struct perf_tool *tool,
+			       union perf_event *event,
+			       struct perf_sample *sample __maybe_unused,
+			       struct machine *machine __maybe_unused)
+{
+	struct cs_etm_synth *cs_etm_synth =
+		      container_of(tool, struct cs_etm_synth, dummy_tool);
+
+	return perf_session__deliver_synth_event(cs_etm_synth->session,
+						 event, NULL);
+}
+
+static int cs_etm__synth_event(struct perf_session *session,
+			       struct perf_event_attr *attr, u64 id)
+{
+	struct cs_etm_synth cs_etm_synth;
+
+	memset(&cs_etm_synth, 0, sizeof(struct cs_etm_synth));
+	cs_etm_synth.session = session;
+
+	return perf_event__synthesize_attr(&cs_etm_synth.dummy_tool, attr, 1,
+					   &id, cs_etm__event_synth);
+}
+
+static int cs_etm__synth_events(struct cs_etm_auxtrace *etm,
+				struct perf_session *session)
+{
+	struct perf_evlist *evlist = session->evlist;
+	struct perf_evsel *evsel;
+	struct perf_event_attr attr;
+	bool found = false;
+	u64 id;
+	int err;
+
+	evlist__for_each_entry(evlist, evsel) {
+		if (evsel->attr.type == etm->pmu_type) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		pr_debug("No selected events with CoreSight Trace data\n");
+		return 0;
+	}
+
+	memset(&attr, 0, sizeof(struct perf_event_attr));
+	attr.size = sizeof(struct perf_event_attr);
+	attr.type = PERF_TYPE_HARDWARE;
+	attr.sample_type = evsel->attr.sample_type & PERF_SAMPLE_MASK;
+	attr.sample_type |= PERF_SAMPLE_IP | PERF_SAMPLE_TID |
+			    PERF_SAMPLE_PERIOD;
+	if (etm->timeless_decoding)
+		attr.sample_type &= ~(u64)PERF_SAMPLE_TIME;
+	else
+		attr.sample_type |= PERF_SAMPLE_TIME;
+
+	attr.exclude_user = evsel->attr.exclude_user;
+	attr.exclude_kernel = evsel->attr.exclude_kernel;
+	attr.exclude_hv = evsel->attr.exclude_hv;
+	attr.exclude_host = evsel->attr.exclude_host;
+	attr.exclude_guest = evsel->attr.exclude_guest;
+	attr.sample_id_all = evsel->attr.sample_id_all;
+	attr.read_format = evsel->attr.read_format;
+
+	/* create new id val to be a fixed offset from evsel id */
+	id = evsel->id[0] + 1000000000;
+
+	if (!id)
+		id = 1;
+
+	if (etm->synth_opts.branches) {
+		attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS;
+		attr.sample_period = 1;
+		attr.sample_type |= PERF_SAMPLE_ADDR;
+		err = cs_etm__synth_event(session, &attr, id);
+		if (err)
+			return err;
+		etm->sample_branches = true;
+		etm->branches_sample_type = attr.sample_type;
+		etm->branches_id = id;
+	}
+
+	return 0;
+}
+
+static int cs_etm__sample(struct cs_etm_queue *etmq)
+{
+	int ret;
+	struct cs_etm_packet packet;
+
+	while (1) {
+		ret = cs_etm_decoder__get_packet(etmq->decoder, &packet);
+		if (ret <= 0)
+			return ret;
+
+		/*
+		 * If the packet contains an instruction range, generate an
+		 * instruction sequence event.
+		 */
+		if (packet.sample_type & CS_ETM_RANGE)
+			cs_etm__synth_branch_sample(etmq, &packet);
+	}
+
+	return 0;
+}
+
 static int cs_etm__run_decoder(struct cs_etm_queue *etmq)
 {
 	struct cs_etm_auxtrace *etm = etmq->etm;
@@ -494,6 +645,12 @@ more:
 
 		etmq->offset += processed;
 		buffer_used += processed;
+
+		/*
+		 * Nothing to do with an error condition, let's hope the next
+		 * chunk will be better.
+		 */
+		err = cs_etm__sample(etmq);
 	} while (buffer.len > buffer_used);
 
 goto more;
@@ -828,6 +985,17 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
 		return 0;
 	}
 
+	if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
+		etm->synth_opts = *session->itrace_synth_opts;
+	} else {
+		itrace_synth_opts__set_default(&etm->synth_opts);
+		etm->synth_opts.callchain = false;
+	}
+
+	err = cs_etm__synth_events(etm, session);
+	if (err)
+		goto err_free_queues;
+
 	err = auxtrace_queues__process_index(&etm->queues, session);
 	if (err)
 		goto err_free_queues;