[PATCH 1/4] perf arm_spe: Make a function to get the MIDR

James Clark
2026-04-01T14:26:11Z

We'll need the MIDR to dump IMPDEF events in the next commits so extract
a function for it.

No functional changes intended.

Signed-off-by: James Clark <james.clark@linaro.org>
---
tools/perf/util/arm-spe.c | 36 ++++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
index 70dd9bee47c7..7447b000f9cd 100644
--- a/tools/perf/util/arm-spe.c
+++ b/tools/perf/util/arm-spe.c
@@ -958,14 +958,9 @@ static void arm_spe__synth_memory_level(struct arm_spe_queue *speq,
}
}

-static void arm_spe__synth_ds(struct arm_spe_queue *speq,
- const struct arm_spe_record *record,
- union perf_mem_data_src *data_src)
+static int arm_spe__get_midr(struct arm_spe *spe, int cpu, u64 *midr)
{
- struct arm_spe *spe = speq->spe;
- u64 *metadata = NULL;
- u64 midr;
- unsigned int i;
+ u64 *metadata;

/* Metadata version 1 assumes all CPUs are the same (old behavior) */
if (spe->metadata_ver == 1) {
@@ -973,15 +968,28 @@ static void arm_spe__synth_ds(struct arm_spe_queue *speq,

pr_warning_once("Old SPE metadata, re-record to improve decode accuracy\n");
cpuid = perf_env__cpuid(perf_session__env(spe->session));
- midr = strtol(cpuid, NULL, 16);
- } else {
- metadata = arm_spe__get_metadata_by_cpu(spe, speq->cpu);
- if (!metadata)
- return;
-
- midr = metadata[ARM_SPE_CPU_MIDR];
+ *midr = strtol(cpuid, NULL, 16);
+ return 0;
}

+ metadata = arm_spe__get_metadata_by_cpu(spe, cpu);
+ if (!metadata)
+ return -EINVAL;
+
+ *midr = metadata[ARM_SPE_CPU_MIDR];
+ return 0;
+}
+
+static void arm_spe__synth_ds(struct arm_spe_queue *speq,
+ const struct arm_spe_record *record,
+ union perf_mem_data_src *data_src)
+{
+ u64 midr;
+ unsigned int i;
+
+ if (arm_spe__get_midr(speq->spe, speq->cpu, &midr))
+ return;
+
for (i = 0; i < ARRAY_SIZE(data_source_handles); i++) {
if (is_midr_in_range_list(midr, data_source_handles[i].midr_ranges)) {
return data_source_handles[i].ds_synth(record, data_src);

--
2.34.1