[PATCH v9 5/5] perf arm-spe: Use SPE data source for neoverse cores

Ali Saidi
2022-05-17T02:05:18Z

When synthesizing data from SPE, augment the type with source information
for Arm Neoverse cores. The field is IMPLDEF but the Neoverse cores all use
the same encoding. I can't find encoding information for any other SPE
implementations to unify their choices with Arm's thus that is left for
future work.

This change populates the mem_lvl_num for Neoverse cores as well as the
deprecated mem_lvl namespace.

Signed-off-by: Ali Saidi <alisaidi@amazon.com>
Reviewed-by: German Gomez <german.gomez@arm.com>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
---
.../util/arm-spe-decoder/arm-spe-decoder.c | 1 +
.../util/arm-spe-decoder/arm-spe-decoder.h | 12 ++
tools/perf/util/arm-spe.c | 130 +++++++++++++++---
3 files changed, 127 insertions(+), 16 deletions(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
index 5e390a1a79ab..091987dd3966 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
@@ -220,6 +220,7 @@ static int arm_spe_read_record(struct arm_spe_decoder *decoder)

break;
case ARM_SPE_DATA_SOURCE:
+ decoder->record.source = payload;
break;
case ARM_SPE_BAD:
break;
diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
index 69b31084d6be..46a61df1145b 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
@@ -29,6 +29,17 @@ enum arm_spe_op_type {
ARM_SPE_ST = 1 << 1,
};

+enum arm_spe_neoverse_data_source {
+ ARM_SPE_NV_L1D = 0x0,
+ ARM_SPE_NV_L2 = 0x8,
+ ARM_SPE_NV_PEER_CORE = 0x9,
+ ARM_SPE_NV_LOCAL_CLUSTER = 0xa,
+ ARM_SPE_NV_SYS_CACHE = 0xb,
+ ARM_SPE_NV_PEER_CLUSTER = 0xc,
+ ARM_SPE_NV_REMOTE = 0xd,
+ ARM_SPE_NV_DRAM = 0xe,
+};
+
struct arm_spe_record {
enum arm_spe_sample_type type;
int err;
@@ -40,6 +51,7 @@ struct arm_spe_record {
u64 virt_addr;
u64 phys_addr;
u64 context_id;
+ u16 source;
};

struct arm_spe_insn;
diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
index e032efc03274..aa8f2bc5475e 100644
--- a/tools/perf/util/arm-spe.c
+++ b/tools/perf/util/arm-spe.c
@@ -34,6 +34,7 @@
#include "arm-spe-decoder/arm-spe-decoder.h"
#include "arm-spe-decoder/arm-spe-pkt-decoder.h"

+#include "../../arch/arm64/include/asm/cputype.h"
#define MAX_TIMESTAMP (~0ULL)

struct arm_spe {
@@ -45,6 +46,7 @@ struct arm_spe {
struct perf_session *session;
struct machine *machine;
u32 pmu_type;
+ u64 midr;

struct perf_tsc_conversion tc;

@@ -387,35 +389,128 @@ static int arm_spe__synth_instruction_sample(struct arm_spe_queue *speq,
return arm_spe_deliver_synth_event(spe, speq, event, &sample);
}

-static u64 arm_spe__synth_data_source(const struct arm_spe_record *record)
+static const struct midr_range neoverse_spe[] = {
+ MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1),
+ MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2),
+ MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V1),
+ {},
+};
+
+static void arm_spe__synth_data_source_neoverse(const struct arm_spe_record *record,
+ union perf_mem_data_src *data_src)
{
- union perf_mem_data_src data_src = { 0 };
+ /*
+ * Even though four levels of cache hierarchy are possible, no known
+ * production Neoverse systems currently include more than three levels
+ * so for the time being we assume three exist. If a production system
+ * is built with four the this function would have to be changed to
+ * detect the number of levels for reporting.
+ */

- if (record->op == ARM_SPE_LD)
- data_src.mem_op = PERF_MEM_OP_LOAD;
- else if (record->op == ARM_SPE_ST)
- data_src.mem_op = PERF_MEM_OP_STORE;
- else
- return 0;
+ /*
+ * We have no data on the hit level or data source for stores in the
+ * Neoverse SPE records.
+ */
+ if (record->op & ARM_SPE_ST) {
+ data_src->mem_lvl = PERF_MEM_LVL_NA;
+ data_src->mem_lvl_num = PERF_MEM_LVLNUM_NA;
+ data_src->mem_snoop = PERF_MEM_SNOOP_NA;
+ return;
+ }
+
+ switch (record->source) {
+ case ARM_SPE_NV_L1D:
+ data_src->mem_lvl = PERF_MEM_LVL_L1 | PERF_MEM_LVL_HIT;
+ data_src->mem_lvl_num = PERF_MEM_LVLNUM_L1;
+ data_src->mem_snoop = PERF_MEM_SNOOP_NONE;
+ break;
+ case ARM_SPE_NV_L2:
+ data_src->mem_lvl = PERF_MEM_LVL_L2 | PERF_MEM_LVL_HIT;
+ data_src->mem_lvl_num = PERF_MEM_LVLNUM_L2;
+ data_src->mem_snoop = PERF_MEM_SNOOP_NONE;
+ break;
+ case ARM_SPE_NV_PEER_CORE:
+ data_src->mem_lvl = PERF_MEM_LVL_L2 | PERF_MEM_LVL_HIT;
+ data_src->mem_lvl_num = PERF_MEM_LVLNUM_L2;
+ data_src->mem_snoopx = PERF_MEM_SNOOPX_PEER;
+ break;
+ /*
+ * We don't know if this is L1, L2 but we do know it was a cache-2-cache
+ * transfer, so set SNOOPX_PEER
+ */
+ case ARM_SPE_NV_LOCAL_CLUSTER:
+ case ARM_SPE_NV_PEER_CLUSTER:
+ data_src->mem_lvl = PERF_MEM_LVL_L3 | PERF_MEM_LVL_HIT;
+ data_src->mem_lvl_num = PERF_MEM_LVLNUM_L3;
+ data_src->mem_snoopx = PERF_MEM_SNOOPX_PEER;
+ break;
+ /*
+ * System cache is assumed to be L3
+ */
+ case ARM_SPE_NV_SYS_CACHE:
+ data_src->mem_lvl = PERF_MEM_LVL_L3 | PERF_MEM_LVL_HIT;
+ data_src->mem_lvl_num = PERF_MEM_LVLNUM_L3;
+ data_src->mem_snoop = PERF_MEM_SNOOP_HIT;
+ break;
+ /*
+ * We don't know what level it hit in, except it came from the other
+ * socket
+ */
+ case ARM_SPE_NV_REMOTE:
+ data_src->mem_lvl = PERF_MEM_LVL_REM_CCE1;
+ data_src->mem_lvl_num = PERF_MEM_LVLNUM_ANY_CACHE;
+ data_src->mem_remote = PERF_MEM_REMOTE_REMOTE;
+ data_src->mem_snoopx = PERF_MEM_SNOOPX_PEER;
+ break;
+ case ARM_SPE_NV_DRAM:
+ data_src->mem_lvl = PERF_MEM_LVL_LOC_RAM | PERF_MEM_LVL_HIT;
+ data_src->mem_lvl_num = PERF_MEM_LVLNUM_RAM;
+ data_src->mem_snoop = PERF_MEM_SNOOP_NONE;
+ break;
+ default:
+ break;
+ }
+}

+static void arm_spe__synth_data_source_generic(const struct arm_spe_record *record,
+ union perf_mem_data_src *data_src)
+{
if (record->type & (ARM_SPE_LLC_ACCESS | ARM_SPE_LLC_MISS)) {
- data_src.mem_lvl = PERF_MEM_LVL_L3;
+ data_src->mem_lvl = PERF_MEM_LVL_L3;

if (record->type & ARM_SPE_LLC_MISS)
- data_src.mem_lvl |= PERF_MEM_LVL_MISS;
+ data_src->mem_lvl |= PERF_MEM_LVL_MISS;
else
- data_src.mem_lvl |= PERF_MEM_LVL_HIT;
+ data_src->mem_lvl |= PERF_MEM_LVL_HIT;
} else if (record->type & (ARM_SPE_L1D_ACCESS | ARM_SPE_L1D_MISS)) {
- data_src.mem_lvl = PERF_MEM_LVL_L1;
+ data_src->mem_lvl = PERF_MEM_LVL_L1;

if (record->type & ARM_SPE_L1D_MISS)
- data_src.mem_lvl |= PERF_MEM_LVL_MISS;
+ data_src->mem_lvl |= PERF_MEM_LVL_MISS;
else
- data_src.mem_lvl |= PERF_MEM_LVL_HIT;
+ data_src->mem_lvl |= PERF_MEM_LVL_HIT;
}

if (record->type & ARM_SPE_REMOTE_ACCESS)
- data_src.mem_lvl |= PERF_MEM_LVL_REM_CCE1;
+ data_src->mem_lvl |= PERF_MEM_LVL_REM_CCE1;
+}
+
+static u64 arm_spe__synth_data_source(const struct arm_spe_record *record, u64 midr)
+{
+ union perf_mem_data_src data_src = { 0 };
+ bool is_neoverse = is_midr_in_range(midr, neoverse_spe);
+
+ if (record->op == ARM_SPE_LD)
+ data_src.mem_op = PERF_MEM_OP_LOAD;
+ else if (record->op == ARM_SPE_ST)
+ data_src.mem_op = PERF_MEM_OP_STORE;
+ else
+ return 0;
+
+ if (is_neoverse)
+ arm_spe__synth_data_source_neoverse(record, &data_src);
+ else
+ arm_spe__synth_data_source_generic(record, &data_src);

if (record->type & (ARM_SPE_TLB_ACCESS | ARM_SPE_TLB_MISS)) {
data_src.mem_dtlb = PERF_MEM_TLB_WK;
@@ -436,7 +531,7 @@ static int arm_spe_sample(struct arm_spe_queue *speq)
u64 data_src;
int err;

- data_src = arm_spe__synth_data_source(record);
+ data_src = arm_spe__synth_data_source(record, spe->midr);

if (spe->sample_flc) {
if (record->type & ARM_SPE_L1D_MISS) {
@@ -1177,6 +1272,8 @@ int arm_spe_process_auxtrace_info(union perf_event *event,
struct perf_record_auxtrace_info *auxtrace_info = &event->auxtrace_info;
size_t min_sz = sizeof(u64) * ARM_SPE_AUXTRACE_PRIV_MAX;
struct perf_record_time_conv *tc = &session->time_conv;
+ const char *cpuid = perf_env__cpuid(session->evlist->env);
+ u64 midr = strtol(cpuid, NULL, 16);
struct arm_spe *spe;
int err;

@@ -1196,6 +1293,7 @@ int arm_spe_process_auxtrace_info(union perf_event *event,
spe->machine = &session->machines.host; /* No kvm support */
spe->auxtrace_type = auxtrace_info->type;
spe->pmu_type = auxtrace_info->priv[ARM_SPE_PMU_TYPE];
+ spe->midr = midr;

spe->timeless_decoding = arm_spe__is_timeless_decoding(spe);

--
2.32.0