[PATCH 36/43] perf tools: Add mechanic to synthesise CoreSight trace packets

From: Arnaldo Carvalho de Melo
Date: Tue Jan 23 2018 - 08:16:44 EST


From: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>

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 407095af1456..b9f0a53dfa65 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 @@ static int cs_etm__run_decoder(struct cs_etm_queue *etmq)

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;
--
2.14.3