perf cs-etm: Modularize main decoder function

Making the main decoder block modular so that it can be called from
different decoding context (timeless vs. non-timeless), avoiding
to repeat code.

No change in functionality is introduced by this patch.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki K Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190212171618.25355-12-mathieu.poirier@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/cs-etm.c

@@ -1491,9 +1491,36 @@ static int cs_etm__set_sample_flags(struct cs_etm_queue *etmq)
 	return 0;
 }
 
+static int cs_etm__decode_data_block(struct cs_etm_queue *etmq)
+{
+	int ret = 0;
+	size_t processed = 0;
+
+	/*
+	 * Packets are decoded and added to the decoder's packet queue
+	 * until the decoder packet processing callback has requested that
+	 * processing stops or there is nothing left in the buffer.  Normal
+	 * operations that stop processing are a timestamp packet or a full
+	 * decoder buffer queue.
+	 */
+	ret = cs_etm_decoder__process_data_block(etmq->decoder,
+						 etmq->offset,
+						 &etmq->buf[etmq->buf_used],
+						 etmq->buf_len,
+						 &processed);
+	if (ret)
+		goto out;
+
+	etmq->offset += processed;
+	etmq->buf_used += processed;
+	etmq->buf_len -= processed;
+
+out:
+	return ret;
+}
+
 static int cs_etm__run_decoder(struct cs_etm_queue *etmq)
 {
-	size_t processed;
 	int err = 0;
 
 	/* Go through each buffer in the queue and decode them one by one */
@@ -1513,20 +1540,10 @@ static int cs_etm__run_decoder(struct cs_etm_queue *etmq)
 
 		/* Run trace decoder until buffer consumed or end of trace */
 		do {
-			processed = 0;
-			err = cs_etm_decoder__process_data_block(
-				etmq->decoder,
-				etmq->offset,
-				&etmq->buf[etmq->buf_used],
-				etmq->buf_len,
-				&processed);
+			err = cs_etm__decode_data_block(etmq);
 			if (err)
 				return err;
 
-			etmq->offset += processed;
-			etmq->buf_used += processed;
-			etmq->buf_len -= processed;
-
 			/* Process each packet in this chunk */
 			while (1) {
 				err = cs_etm_decoder__get_packet(etmq->decoder,