diff options
Diffstat (limited to 'tools/perf/util/cs-etm-decoder/cs-etm-decoder.c')
| -rw-r--r-- | tools/perf/util/cs-etm-decoder/cs-etm-decoder.c | 61 |
1 files changed, 42 insertions, 19 deletions
diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c index 059bcec3f651..3e1a05bc82cc 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c @@ -6,6 +6,7 @@ * Author: Mathieu Poirier <mathieu.poirier@linaro.org> */ +#include <asm/bug.h> #include <linux/coresight-pmu.h> #include <linux/err.h> #include <linux/list.h> @@ -17,6 +18,7 @@ #include "cs-etm.h" #include "cs-etm-decoder.h" +#include "debug.h" #include "intlist.h" /* use raw logging */ @@ -276,13 +278,13 @@ cs_etm_decoder__do_soft_timestamp(struct cs_etm_queue *etmq, const uint8_t trace_chan_id) { /* No timestamp packet has been received, nothing to do */ - if (!packet_queue->timestamp) + if (!packet_queue->cs_timestamp) return OCSD_RESP_CONT; - packet_queue->timestamp = packet_queue->next_timestamp; + packet_queue->cs_timestamp = packet_queue->next_cs_timestamp; /* Estimate the timestamp for the next range packet */ - packet_queue->next_timestamp += packet_queue->instr_count; + packet_queue->next_cs_timestamp += packet_queue->instr_count; packet_queue->instr_count = 0; /* Tell the front end which traceid_queue needs attention */ @@ -294,7 +296,8 @@ cs_etm_decoder__do_soft_timestamp(struct cs_etm_queue *etmq, static ocsd_datapath_resp_t cs_etm_decoder__do_hard_timestamp(struct cs_etm_queue *etmq, const ocsd_generic_trace_elem *elem, - const uint8_t trace_chan_id) + const uint8_t trace_chan_id, + const ocsd_trc_index_t indx) { struct cs_etm_packet_queue *packet_queue; @@ -308,20 +311,39 @@ cs_etm_decoder__do_hard_timestamp(struct cs_etm_queue *etmq, * Function do_soft_timestamp() will report the value to the front end, * hence asking the decoder to keep decoding rather than stopping. */ - if (packet_queue->timestamp) { - packet_queue->next_timestamp = elem->timestamp; + if (packet_queue->cs_timestamp) { + packet_queue->next_cs_timestamp = elem->timestamp; return OCSD_RESP_CONT; } - /* - * This is the first timestamp we've seen since the beginning of traces - * or a discontinuity. Since timestamps packets are generated *after* - * range packets have been generated, we need to estimate the time at - * which instructions started by subtracting the number of instructions - * executed to the timestamp. - */ - packet_queue->timestamp = elem->timestamp - packet_queue->instr_count; - packet_queue->next_timestamp = elem->timestamp; + + if (!elem->timestamp) { + /* + * Zero timestamps can be seen due to misconfiguration or hardware bugs. + * Warn once, and don't try to subtract instr_count as it would result in an + * underflow. + */ + packet_queue->cs_timestamp = 0; + WARN_ONCE(true, "Zero Coresight timestamp found at Idx:%" OCSD_TRC_IDX_STR + ". Decoding may be improved with --itrace=Z...\n", indx); + } else if (packet_queue->instr_count > elem->timestamp) { + /* + * Sanity check that the elem->timestamp - packet_queue->instr_count would not + * result in an underflow. Warn and clamp at 0 if it would. + */ + packet_queue->cs_timestamp = 0; + pr_err("Timestamp calculation underflow at Idx:%" OCSD_TRC_IDX_STR "\n", indx); + } else { + /* + * This is the first timestamp we've seen since the beginning of traces + * or a discontinuity. Since timestamps packets are generated *after* + * range packets have been generated, we need to estimate the time at + * which instructions started by subtracting the number of instructions + * executed to the timestamp. + */ + packet_queue->cs_timestamp = elem->timestamp - packet_queue->instr_count; + } + packet_queue->next_cs_timestamp = elem->timestamp; packet_queue->instr_count = 0; /* Tell the front end which traceid_queue needs attention */ @@ -334,8 +356,8 @@ cs_etm_decoder__do_hard_timestamp(struct cs_etm_queue *etmq, static void cs_etm_decoder__reset_timestamp(struct cs_etm_packet_queue *packet_queue) { - packet_queue->timestamp = 0; - packet_queue->next_timestamp = 0; + packet_queue->cs_timestamp = 0; + packet_queue->next_cs_timestamp = 0; packet_queue->instr_count = 0; } @@ -542,7 +564,7 @@ cs_etm_decoder__set_tid(struct cs_etm_queue *etmq, static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer( const void *context, - const ocsd_trc_index_t indx __maybe_unused, + const ocsd_trc_index_t indx, const u8 trace_chan_id __maybe_unused, const ocsd_generic_trace_elem *elem) { @@ -579,7 +601,8 @@ static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer( break; case OCSD_GEN_TRC_ELEM_TIMESTAMP: resp = cs_etm_decoder__do_hard_timestamp(etmq, elem, - trace_chan_id); + trace_chan_id, + indx); break; case OCSD_GEN_TRC_ELEM_PE_CONTEXT: resp = cs_etm_decoder__set_tid(etmq, packet_queue, |