perf cs-etm: Make cs_etm__run_decoder() queue independent

This patch makes decoding of auxtrace buffer centered around a struct
cs_etm_queue.  This eliminates surperflous variables and is a precursor
for work that simplifies the main decoder loop.

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/20190212171618.25355-11-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 26 insertions, 33 deletions

diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h
index 663309486784..3ab11dfa92ae 100644
--- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h
+++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h
@@ -15,13 +15,6 @@
 
 struct cs_etm_decoder;
 
-struct cs_etm_buffer {
-        const unsigned char *buf;
-        size_t len;
-        u64 offset;
-        u64 ref_timestamp;
-};
-
 enum cs_etm_sample_type {
         CS_ETM_EMPTY,
         CS_ETM_RANGE,
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 2d2de898ea68..d2c90b369e7c 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -76,6 +76,8 @@ struct cs_etm_queue {
         size_t last_branch_pos;
         struct cs_etm_packet *prev_packet;
         struct cs_etm_packet *packet;
+        const unsigned char *buf;
+        size_t buf_len, buf_used;
 };
 
 static int cs_etm__update_queues(struct cs_etm_auxtrace *etm);
@@ -683,7 +685,7 @@ static int cs_etm__inject_event(union perf_event *event,
 
 
 static int
-cs_etm__get_trace(struct cs_etm_buffer *buff, struct cs_etm_queue *etmq)
+cs_etm__get_trace(struct cs_etm_queue *etmq)
 {
         struct auxtrace_buffer *aux_buffer = etmq->buffer;
         struct auxtrace_buffer *old_buffer = aux_buffer;
@@ -697,7 +699,7 @@ cs_etm__get_trace(struct cs_etm_buffer *buff, struct cs_etm_queue *etmq)
         if (!aux_buffer) {
                 if (old_buffer)
                         auxtrace_buffer__drop_data(old_buffer);
-                buff->len = 0;
+                etmq->buf_len = 0;
                 return 0;
         }
 
@@ -717,13 +719,11 @@ cs_etm__get_trace(struct cs_etm_buffer *buff, struct cs_etm_queue *etmq)
         if (old_buffer)
                 auxtrace_buffer__drop_data(old_buffer);
 
-        buff->offset = aux_buffer->offset;
-        buff->len = aux_buffer->size;
-        buff->buf = aux_buffer->data;
+        etmq->buf_used = 0;
+        etmq->buf_len = aux_buffer->size;
+        etmq->buf = aux_buffer->data;
 
-        buff->ref_timestamp = aux_buffer->reference;
-
-        return buff->len;
+        return etmq->buf_len;
 }
 
 static void cs_etm__set_pid_tid_cpu(struct cs_etm_auxtrace *etm,
@@ -1493,24 +1493,23 @@ static int cs_etm__set_sample_flags(struct cs_etm_queue *etmq)
 
 static int cs_etm__run_decoder(struct cs_etm_queue *etmq)
 {
-        struct cs_etm_buffer buffer;
-        size_t buffer_used, processed;
+        size_t processed;
         int err = 0;
 
         /* Go through each buffer in the queue and decode them one by one */
         while (1) {
-                buffer_used = 0;
-                memset(&buffer, 0, sizeof(buffer));
-                err = cs_etm__get_trace(&buffer, etmq);
-                if (err <= 0)
-                        return err;
-                /*
-                 * We cannot assume consecutive blocks in the data file are
-                 * contiguous, reset the decoder to force re-sync.
-                 */
-                err = cs_etm_decoder__reset(etmq->decoder);
-                if (err != 0)
-                        return err;
+                if (!etmq->buf_len) {
+                        err = cs_etm__get_trace(etmq);
+                        if (err <= 0)
+                                return err;
+                        /*
+                         * We cannot assume consecutive blocks in the data file
+                         * are contiguous, reset the decoder to force re-sync.
+                         */
+                        err = cs_etm_decoder__reset(etmq->decoder);
+                        if (err != 0)
+                                return err;
+                }
 
                 /* Run trace decoder until buffer consumed or end of trace */
                 do {
@@ -1518,14 +1517,15 @@ static int cs_etm__run_decoder(struct cs_etm_queue *etmq)
                         err = cs_etm_decoder__process_data_block(
                                 etmq->decoder,
                                 etmq->offset,
-                                &buffer.buf[buffer_used],
-                                buffer.len - buffer_used,
+                                &etmq->buf[etmq->buf_used],
+                                etmq->buf_len,
                                 &processed);
                         if (err)
                                 return err;
 
                         etmq->offset += processed;
-                        buffer_used += processed;
+                        etmq->buf_used += processed;
+                        etmq->buf_len -= processed;
 
                         /* Process each packet in this chunk */
                         while (1) {
@@ -1585,7 +1585,7 @@ static int cs_etm__run_decoder(struct cs_etm_queue *etmq)
                                         break;
                                 }
                         }
-                } while (buffer.len > buffer_used);
+                } while (etmq->buf_len);
 
                 if (err == 0)
                         /* Flush any remaining branch stack entries */