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From:   Leo Yan <leo.yan@linaro.org>
To:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Jonathan Corbet <corbet@lwn.net>,
        John Garry <john.garry@huawei.com>,
        Will Deacon <will@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Daniel Kiss <Daniel.Kiss@arm.com>,
        Denis Nikitin <denik@chromium.org>,
        Al Grant <al.grant@arm.com>, coresight@lists.linaro.org,
        linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Leo Yan <leo.yan@linaro.org>
Subject: [PATCH v3 6/8] perf cs-etm: Add helper cs_etm__get_pid_fmt()
Date:   Sat,  6 Feb 2021 23:08:31 +0800
Message-Id: <20210206150833.42120-7-leo.yan@linaro.org>
In-Reply-To: <20210206150833.42120-1-leo.yan@linaro.org>
References: <20210206150833.42120-1-leo.yan@linaro.org>
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This patch adds helper function cs_etm__get_pid_fmt(), by passing
parameter "traceID", it returns the PID format.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 tools/perf/util/cs-etm.c | 42 ++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/cs-etm.h |  1 +
 2 files changed, 43 insertions(+)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index a2a369e2fbb6..b9c1d329a7f1 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/coresight-pmu.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/log2.h>
@@ -156,6 +157,47 @@ int cs_etm__get_cpu(u8 trace_chan_id, int *cpu)
 	return 0;
 }
 
+/*
+ * The returned PID format is presented by two bits:
+ *
+ *   Bit ETM_OPT_CTXTID: CONTEXTIDR or CONTEXTIDR_EL1 is traced;
+ *   Bit ETM_OPT_CTXTID2: CONTEXTIDR_EL2 is traced.
+ *
+ * It's possible that the two bits ETM_OPT_CTXTID and ETM_OPT_CTXTID2
+ * are enabled at the same time when the session runs on an EL2 kernel.
+ * This means the CONTEXTIDR_EL1 and CONTEXTIDR_EL2 both will be
+ * recorded in the trace data, the tool will selectively use
+ * CONTEXTIDR_EL2 as PID.
+ */
+int cs_etm__get_pid_fmt(u8 trace_chan_id, u64 *pid_fmt)
+{
+	struct int_node *inode;
+	u64 *metadata, val;
+
+	inode = intlist__find(traceid_list, trace_chan_id);
+	if (!inode)
+		return -EINVAL;
+
+	metadata = inode->priv;
+
+	if (metadata[CS_ETM_MAGIC] == __perf_cs_etmv3_magic) {
+		val = metadata[CS_ETM_ETMCR];
+		/* CONTEXTIDR is traced */
+		if (val & BIT(ETM_OPT_CTXTID))
+			*pid_fmt = BIT(ETM_OPT_CTXTID);
+	} else {
+		val = metadata[CS_ETMV4_TRCCONFIGR];
+		/* CONTEXTIDR_EL2 is traced */
+		if (val & (BIT(ETM4_CFG_BIT_VMID) | BIT(ETM4_CFG_BIT_VMID_OPT)))
+			*pid_fmt = BIT(ETM_OPT_CTXTID2);
+		/* CONTEXTIDR_EL1 is traced */
+		else if (val & BIT(ETM4_CFG_BIT_CTXTID))
+			*pid_fmt = BIT(ETM_OPT_CTXTID);
+	}
+
+	return 0;
+}
+
 void cs_etm__etmq_set_traceid_queue_timestamp(struct cs_etm_queue *etmq,
 					      u8 trace_chan_id)
 {
diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
index 4ad925d6d799..7cc3bba0017d 100644
--- a/tools/perf/util/cs-etm.h
+++ b/tools/perf/util/cs-etm.h
@@ -173,6 +173,7 @@ struct cs_etm_packet_queue {
 int cs_etm__process_auxtrace_info(union perf_event *event,
 				  struct perf_session *session);
 int cs_etm__get_cpu(u8 trace_chan_id, int *cpu);
+int cs_etm__get_pid_fmt(u8 trace_chan_id, u64 *pid_fmt);
 int cs_etm__etmq_set_tid(struct cs_etm_queue *etmq,
 			 pid_t tid, u8 trace_chan_id);
 bool cs_etm__etmq_is_timeless(struct cs_etm_queue *etmq);
-- 
2.25.1