perf cs-etm: Change tuple from traceID-CPU# to traceID-metadata

If packet processing wants to know the packet is bound with which ETM
version, it needs to access metadata to decide that based on metadata
magic number; but we cannot simply to use CPU logic ID number as index
to access metadata sequential array, especially when system have
hotplugged off CPUs, the metadata array are only allocated for online
CPUs but not offline CPUs, so the CPU logic number doesn't match with
its index in the array.

This patch is to change tuple from traceID-CPU# to traceID-metadata,
thus it can use the tuple to retrieve metadata pointer according to
traceID.

For safe accessing metadata fields, this patch provides helper function
cs_etm__get_cpu() which is used to return CPU number according to
traceID; cs_etm_decoder__buffer_packet() is the first consumer for this
helper function.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: Suzuki K Poulouse <suzuki.poulose@arm.com>
Cc: coresight ml <coresight@lists.linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190129122842.32041-6-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
index 37f8d48179ca..fb5fc6538b7f 100644
--- a/tools/perf/util/cs-etm.h
+++ b/tools/perf/util/cs-etm.h
@@ -53,7 +53,7 @@ enum {
 	CS_ETMV4_PRIV_MAX,
 };
 
-/* RB tree for quick conversion between traceID and CPUs */
+/* RB tree for quick conversion between traceID and metadata pointers */
 struct intlist *traceid_list;
 
 #define KiB(x) ((x) * 1024)
@@ -69,6 +69,7 @@ static const u64 __perf_cs_etmv4_magic   = 0x4040404040404040ULL;
 #ifdef HAVE_CSTRACE_SUPPORT
 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);
 #else
 static inline int
 cs_etm__process_auxtrace_info(union perf_event *event __maybe_unused,
@@ -76,6 +77,12 @@ cs_etm__process_auxtrace_info(union perf_event *event __maybe_unused,
 {
 	return -1;
 }
+
+static inline int cs_etm__get_cpu(u8 trace_chan_id __maybe_unused,
+				  int *cpu __maybe_unused)
+{
+	return -1;
+}
 #endif
 
 #endif