[PATCH v1 2/3] perf session: Add swap operation for event TIME_CONV

From: Leo Yan <leo.yan@linaro.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Steve MacLean <Steve.MacLean@Microsoft.com>,
	Yonatan Goldschmidt <yonatan.goldschmidt@granulate.io>,
	Kan Liang <kan.liang@linux.intel.com>,
	linux-kernel@vger.kernel.org
Cc: Leo Yan <leo.yan@linaro.org>
Subject: [PATCH v1 2/3] perf session: Add swap operation for event TIME_CONV
Date: Mon, 12 Apr 2021 16:34:58 +0800	[thread overview]
Message-ID: <20210412083459.462817-3-leo.yan@linaro.org> (raw)
In-Reply-To: <20210412083459.462817-1-leo.yan@linaro.org>

Since commit d110162cafc8 ("perf tsc: Support cap_user_time_short for
event TIME_CONV"), the event PERF_RECORD_TIME_CONV has extended the data
structure for clock parameters.

To be backwards-compatible, this patch adds a dedicated swap operation
for the event PERF_RECORD_TIME_CONV, based on checking the event size,
it can support both for the old and new event formats.

Fixes: d110162cafc8 ("perf tsc: Support cap_user_time_short for event TIME_CONV")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 tools/perf/util/session.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 9a8808507bd9..afca3d5fc851 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -949,6 +949,26 @@ static void perf_event__stat_round_swap(union perf_event *event,
 	event->stat_round.time = bswap_64(event->stat_round.time);
 }
 
+static void perf_event__time_conv_swap(union perf_event *event,
+				       bool sample_id_all __maybe_unused)
+{
+	size_t time_zero_size;
+
+	event->time_conv.time_shift = bswap_64(event->time_conv.time_shift);
+	event->time_conv.time_mult  = bswap_64(event->time_conv.time_mult);
+	event->time_conv.time_zero  = bswap_64(event->time_conv.time_zero);
+
+	time_zero_size = (void *)&event->time_conv.time_cycles - (void *)event;
+	if (event->header.size > time_zero_size) {
+		event->time_conv.time_cycles = bswap_64(event->time_conv.time_cycles);
+		event->time_conv.time_mask = bswap_64(event->time_conv.time_mask);
+		event->time_conv.cap_user_time_zero =
+			bswap_32(event->time_conv.cap_user_time_zero);
+		event->time_conv.cap_user_time_short =
+			bswap_32(event->time_conv.cap_user_time_short);
+	}
+}
+
 typedef void (*perf_event__swap_op)(union perf_event *event,
 				    bool sample_id_all);
 
@@ -985,7 +1005,7 @@ static perf_event__swap_op perf_event__swap_ops[] = {
 	[PERF_RECORD_STAT]		  = perf_event__stat_swap,
 	[PERF_RECORD_STAT_ROUND]	  = perf_event__stat_round_swap,
 	[PERF_RECORD_EVENT_UPDATE]	  = perf_event__event_update_swap,
-	[PERF_RECORD_TIME_CONV]		  = perf_event__all64_swap,
+	[PERF_RECORD_TIME_CONV]		  = perf_event__time_conv_swap,
 	[PERF_RECORD_HEADER_MAX]	  = NULL,
 };
 
-- 
2.25.1

