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 | 47 |
1 files changed, 39 insertions, 8 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 31fa3b45134a..440fe844ed17 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c @@ -30,6 +30,15 @@ #endif #endif +/* + * Assume a maximum of 0.1ns elapsed per instruction. This would be the + * case with a theoretical 10GHz core executing 1 instruction per cycle. + * Used to estimate the sample time for synthesized instructions because + * Coresight only emits a timestamp for a range of instructions rather + * than per instruction. + */ +const u32 INSTR_PER_NS = 10; + struct cs_etm_decoder { void *data; void (*packet_printer)(const char *msg); @@ -112,6 +121,20 @@ int cs_etm_decoder__get_packet(struct cs_etm_packet_queue *packet_queue, return 1; } +/* + * Calculate the number of nanoseconds elapsed. + * + * instr_count is updated in place with the remainder of the instructions + * which didn't make up a whole nanosecond. + */ +static u32 cs_etm_decoder__dec_instr_count_to_ns(u32 *instr_count) +{ + const u32 instr_copy = *instr_count; + + *instr_count %= INSTR_PER_NS; + return instr_copy / INSTR_PER_NS; +} + static int cs_etm_decoder__gen_etmv3_config(struct cs_etm_trace_params *params, ocsd_etmv3_cfg *config) { @@ -267,8 +290,8 @@ cs_etm_decoder__do_soft_timestamp(struct cs_etm_queue *etmq, packet_queue->cs_timestamp = packet_queue->next_cs_timestamp; /* Estimate the timestamp for the next range packet */ - packet_queue->next_cs_timestamp += packet_queue->instr_count; - packet_queue->instr_count = 0; + packet_queue->next_cs_timestamp += + cs_etm_decoder__dec_instr_count_to_ns(&packet_queue->instr_count); /* Tell the front end which traceid_queue needs attention */ cs_etm__etmq_set_traceid_queue_timestamp(etmq, trace_chan_id); @@ -283,6 +306,7 @@ cs_etm_decoder__do_hard_timestamp(struct cs_etm_queue *etmq, const ocsd_trc_index_t indx) { struct cs_etm_packet_queue *packet_queue; + u64 converted_timestamp; /* First get the packet queue for this traceID */ packet_queue = cs_etm__etmq_get_packet_queue(etmq, trace_chan_id); @@ -290,17 +314,23 @@ cs_etm_decoder__do_hard_timestamp(struct cs_etm_queue *etmq, return OCSD_RESP_FATAL_SYS_ERR; /* + * Coresight timestamps are raw timer values which need to be scaled to ns. Assume + * 0 is a bad value so don't try to convert it. + */ + converted_timestamp = elem->timestamp ? + cs_etm__convert_sample_time(etmq, elem->timestamp) : 0; + + /* * We've seen a timestamp packet before - simply record the new value. * 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->cs_timestamp) { - packet_queue->next_cs_timestamp = elem->timestamp; + packet_queue->next_cs_timestamp = converted_timestamp; return OCSD_RESP_CONT; } - - if (!elem->timestamp) { + if (!converted_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 @@ -312,7 +342,7 @@ cs_etm_decoder__do_hard_timestamp(struct cs_etm_queue *etmq, ". Decoding may be improved by prepending 'Z' to your current --itrace arguments.\n", indx); - } else if (packet_queue->instr_count > elem->timestamp) { + } else if (packet_queue->instr_count / INSTR_PER_NS > converted_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. @@ -327,9 +357,10 @@ cs_etm_decoder__do_hard_timestamp(struct cs_etm_queue *etmq, * 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->cs_timestamp = converted_timestamp - + (packet_queue->instr_count / INSTR_PER_NS); } - packet_queue->next_cs_timestamp = elem->timestamp; + packet_queue->next_cs_timestamp = converted_timestamp; packet_queue->instr_count = 0; /* Tell the front end which traceid_queue needs attention */ |