[PATCH v4 4/5] perf arm-spe: Support metadata version 2

[Leo Yan]

This commit is to support metadata version 2 and at the meantime it is
backward compatible for version 1's format.

The metadata version 1 doesn't include the ARM_SPE_HEADER_VERSION field.
As version 1 is fixed with two u64 fields, by checking the metadata
size, it distinguishes the metadata is version 1 or version 2 (and any
new versions if later will have). For version 2, it reads out CPU number
and retrieves the metadata info for every CPU.

Signed-off-by: Leo Yan <leo.yan@xxxxxxx>
Reviewed-by: James Clark <james.clark@xxxxxxxxxx>
---
 tools/perf/util/arm-spe.c | 99 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 95 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
index 70989b1bae47..8b2af1c7dc9b 100644
--- a/tools/perf/util/arm-spe.c
+++ b/tools/perf/util/arm-spe.c
@@ -78,6 +78,10 @@ struct arm_spe {
 
 	unsigned long			num_events;
 	u8				use_ctx_pkt_for_pid;
+
+	u64				**metadata;
+	u64				metadata_ver;
+	u64				metadata_nr_cpu;
 };
 
 struct arm_spe_queue {
@@ -1016,6 +1020,73 @@ static int arm_spe_flush(struct perf_session *session __maybe_unused,
 	return 0;
 }
 
+static u64 *arm_spe__alloc_per_cpu_metadata(u64 *buf, int per_cpu_size)
+{
+	u64 *metadata;
+
+	metadata = zalloc(per_cpu_size);
+	if (!metadata)
+		return NULL;
+
+	memcpy(metadata, buf, per_cpu_size);
+	return metadata;
+}
+
+static void arm_spe__free_metadata(u64 **metadata, int nr_cpu)
+{
+	int i;
+
+	for (i = 0; i < nr_cpu; i++)
+		zfree(&metadata[i]);
+	free(metadata);
+}
+
+static u64 **arm_spe__alloc_metadata(struct perf_record_auxtrace_info *info,
+				     u64 *ver, int *nr_cpu)
+{
+	u64 *ptr = (u64 *)info->priv;
+	u64 metadata_size;
+	u64 **metadata = NULL;
+	int hdr_sz, per_cpu_sz, i;
+
+	metadata_size = info->header.size -
+		sizeof(struct perf_record_auxtrace_info);
+
+	/* Metadata version 1 */
+	if (metadata_size == ARM_SPE_AUXTRACE_V1_PRIV_SIZE) {
+		*ver = 1;
+		*nr_cpu = 0;
+		/* No per CPU metadata */
+		return NULL;
+	}
+
+	*ver = ptr[ARM_SPE_HEADER_VERSION];
+	hdr_sz = ptr[ARM_SPE_HEADER_SIZE];
+	*nr_cpu = ptr[ARM_SPE_CPUS_NUM];
+
+	metadata = calloc(*nr_cpu, sizeof(*metadata));
+	if (!metadata)
+		return NULL;
+
+	/* Locate the start address of per CPU metadata */
+	ptr += hdr_sz;
+	per_cpu_sz = (metadata_size - (hdr_sz * sizeof(u64))) / (*nr_cpu);
+
+	for (i = 0; i < *nr_cpu; i++) {
+		metadata[i] = arm_spe__alloc_per_cpu_metadata(ptr, per_cpu_sz);
+		if (!metadata[i])
+			goto err_per_cpu_metadata;
+
+		ptr += per_cpu_sz / sizeof(u64);
+	}
+
+	return metadata;
+
+err_per_cpu_metadata:
+	arm_spe__free_metadata(metadata, *nr_cpu);
+	return NULL;
+}
+
 static void arm_spe_free_queue(void *priv)
 {
 	struct arm_spe_queue *speq = priv;
@@ -1050,6 +1121,7 @@ static void arm_spe_free(struct perf_session *session)
 	auxtrace_heap__free(&spe->heap);
 	arm_spe_free_events(session);
 	session->auxtrace = NULL;
+	arm_spe__free_metadata(spe->metadata, spe->metadata_nr_cpu);
 	free(spe);
 }
 
@@ -1267,15 +1339,26 @@ int arm_spe_process_auxtrace_info(union perf_event *event,
 	const char *cpuid = perf_env__cpuid(session->evlist->env);
 	u64 midr = strtol(cpuid, NULL, 16);
 	struct arm_spe *spe;
-	int err;
+	u64 **metadata = NULL;
+	u64 metadata_ver;
+	int nr_cpu, err;
 
 	if (auxtrace_info->header.size < sizeof(struct perf_record_auxtrace_info) +
 					min_sz)
 		return -EINVAL;
 
+	metadata = arm_spe__alloc_metadata(auxtrace_info, &metadata_ver,
+					   &nr_cpu);
+	if (!metadata && metadata_ver != 1) {
+		pr_err("Failed to parse Arm SPE metadata.\n");
+		return -EINVAL;
+	}
+
 	spe = zalloc(sizeof(struct arm_spe));
-	if (!spe)
-		return -ENOMEM;
+	if (!spe) {
+		err = -ENOMEM;
+		goto err_free_metadata;
+	}
 
 	err = auxtrace_queues__init(&spe->queues);
 	if (err)
@@ -1284,8 +1367,14 @@ int arm_spe_process_auxtrace_info(union perf_event *event,
 	spe->session = session;
 	spe->machine = &session->machines.host; /* No kvm support */
 	spe->auxtrace_type = auxtrace_info->type;
-	spe->pmu_type = auxtrace_info->priv[ARM_SPE_PMU_TYPE];
+	if (metadata_ver == 1)
+		spe->pmu_type = auxtrace_info->priv[ARM_SPE_PMU_TYPE];
+	else
+		spe->pmu_type = auxtrace_info->priv[ARM_SPE_PMU_TYPE_V2];
 	spe->midr = midr;
+	spe->metadata = metadata;
+	spe->metadata_ver = metadata_ver;
+	spe->metadata_nr_cpu = nr_cpu;
 
 	spe->timeless_decoding = arm_spe__is_timeless_decoding(spe);
 
@@ -1346,5 +1435,7 @@ int arm_spe_process_auxtrace_info(union perf_event *event,
 	session->auxtrace = NULL;
 err_free:
 	free(spe);
+err_free_metadata:
+	arm_spe__free_metadata(metadata, nr_cpu);
 	return err;
 }
-- 
2.34.1