@@ -101,6 +101,7 @@ struct arm_spe_queue {
struct thread *thread;
u64 period_instructions;
u32 flags;
+ struct branch_stack *last_branch;
};
struct data_source_handle {
@@ -231,6 +232,16 @@ static struct arm_spe_queue *arm_spe__alloc_queue(struct arm_spe *spe,
params.get_trace = arm_spe_get_trace;
params.data = speq;
+ if (spe->synth_opts.last_branch) {
+ size_t sz = sizeof(struct branch_stack);
+
+ /* Allocate one entry for TGT */
+ sz += sizeof(struct branch_entry);
+ speq->last_branch = zalloc(sz);
+ if (!speq->last_branch)
+ goto out_free;
+ }
+
/* create new decoder */
speq->decoder = arm_spe_decoder_new(¶ms);
if (!speq->decoder)
@@ -240,6 +251,7 @@ static struct arm_spe_queue *arm_spe__alloc_queue(struct arm_spe *spe,
out_free:
zfree(&speq->event_buf);
+ zfree(&speq->last_branch);
free(speq);
return NULL;
@@ -346,6 +358,73 @@ static void arm_spe_prep_sample(struct arm_spe *spe,
event->sample.header.size = sizeof(struct perf_event_header);
}
+static void arm_spe__prep_branch_stack(struct arm_spe_queue *speq)
+{
+ struct arm_spe_record *record = &speq->decoder->record;
+ struct branch_stack *bstack = speq->last_branch;
+ struct branch_flags *bs_flags;
+ size_t sz = sizeof(struct branch_stack) +
+ sizeof(struct branch_entry) /* TGT */;
+
+ /* Clean up branch stack */
+ memset(bstack, 0x0, sz);
+
+ if (!(speq->flags & PERF_IP_FLAG_BRANCH))
+ return;
+
+ bstack->entries[0].from = record->from_ip;
+ bstack->entries[0].to = record->to_ip;
+
+ bs_flags = &bstack->entries[0].flags;
+ bs_flags->value = 0;
+
+ if (record->op & ARM_SPE_OP_BR_CR_BL) {
+ if (record->op & ARM_SPE_OP_BR_COND)
+ bs_flags->type |= PERF_BR_COND_CALL;
+ else
+ bs_flags->type |= PERF_BR_CALL;
+ /*
+ * Indirect branch instruction without link (e.g. BR),
+ * take this case as function return.
+ */
+ } else if (record->op & ARM_SPE_OP_BR_CR_RET ||
+ record->op & ARM_SPE_OP_BR_INDIRECT) {
+ if (record->op & ARM_SPE_OP_BR_COND)
+ bs_flags->type |= PERF_BR_COND_RET;
+ else
+ bs_flags->type |= PERF_BR_RET;
+ } else if (record->op & ARM_SPE_OP_BR_CR_NON_BL_RET) {
+ if (record->op & ARM_SPE_OP_BR_COND)
+ bs_flags->type |= PERF_BR_COND;
+ else
+ bs_flags->type |= PERF_BR_UNCOND;
+ } else {
+ if (record->op & ARM_SPE_OP_BR_COND)
+ bs_flags->type |= PERF_BR_COND;
+ else
+ bs_flags->type |= PERF_BR_UNKNOWN;
+ }
+
+ if (record->type & ARM_SPE_BRANCH_MISS) {
+ bs_flags->mispred = 1;
+ bs_flags->predicted = 0;
+ } else {
+ bs_flags->mispred = 0;
+ bs_flags->predicted = 1;
+ }
+
+ if (record->type & ARM_SPE_BRANCH_NOT_TAKEN)
+ bs_flags->not_taken = 1;
+
+ if (record->type & ARM_SPE_IN_TXN)
+ bs_flags->in_tx = 1;
+
+ bs_flags->cycles = min(record->latency, 0xFFFFU);
+
+ bstack->nr = 1;
+ bstack->hw_idx = -1ULL;
+}
+
static int arm_spe__inject_event(union perf_event *event, struct perf_sample *sample, u64 type)
{
event->header.size = perf_event__sample_event_size(sample, type, 0);
@@ -414,6 +493,7 @@ static int arm_spe__synth_branch_sample(struct arm_spe_queue *speq,
sample.addr = record->to_ip;
sample.weight = record->latency;
sample.flags = speq->flags;
+ sample.branch_stack = speq->last_branch;
ret = arm_spe_deliver_synth_event(spe, speq, event, &sample);
perf_sample__exit(&sample);
@@ -448,6 +528,7 @@ static int arm_spe__synth_instruction_sample(struct arm_spe_queue *speq,
sample.period = spe->instructions_sample_period;
sample.weight = record->latency;
sample.flags = speq->flags;
+ sample.branch_stack = speq->last_branch;
ret = arm_spe_deliver_synth_event(spe, speq, event, &sample);
perf_sample__exit(&sample);
@@ -781,6 +862,10 @@ static int arm_spe_sample(struct arm_spe_queue *speq)
}
}
+ if (spe->synth_opts.last_branch &&
+ (spe->sample_branch || spe->sample_instructions))
+ arm_spe__prep_branch_stack(speq);
+
if (spe->sample_branch && (record->op & ARM_SPE_OP_BRANCH_ERET)) {
err = arm_spe__synth_branch_sample(speq, spe->branch_id);
if (err)
@@ -1272,6 +1357,7 @@ static void arm_spe_free_queue(void *priv)
thread__zput(speq->thread);
arm_spe_decoder_free(speq->decoder);
zfree(&speq->event_buf);
+ zfree(&speq->last_branch);
free(speq);
}
@@ -1491,6 +1577,19 @@ arm_spe_synth_events(struct arm_spe *spe, struct perf_session *session)
id += 1;
}
+ if (spe->synth_opts.last_branch) {
+ if (spe->synth_opts.last_branch_sz > 1)
+ pr_debug("Arm SPE supports only one bstack entry (TGT).\n");
+
+ attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;
+ /*
+ * We don't use the hardware index, but the sample generation
+ * code uses the new format branch_stack with this field,
+ * so the event attributes must indicate that it's present.
+ */
+ attr.branch_sample_type |= PERF_SAMPLE_BRANCH_HW_INDEX;
+ }
+
if (spe->synth_opts.branches) {
spe->sample_branch = true;