[PATCH v2 1/2] perf arm-spe: Use SPE data source for neoverse cores

Ali Saidi alisaidi at amazon.com
Mon Feb 21 14:47:59 PST 2022


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 instead of the
deprecated mem_lvl namespace.

Signed-off-by: Ali Saidi <alisaidi at amazon.com>
---
 .../util/arm-spe-decoder/arm-spe-decoder.c    |   1 +
 .../util/arm-spe-decoder/arm-spe-decoder.h    |  12 ++
 tools/perf/util/arm-spe.c                     | 106 +++++++++++++++---
 3 files changed, 104 insertions(+), 15 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..c81bf90c0996 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_LCL_CLSTR  = 0xa,
+	ARM_SPE_NV_SYS_CACHE  = 0xb,
+	ARM_SPE_NV_PEER_CLSTR = 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 d2b64e3f588b..e0243c2fed5f 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;
 
@@ -399,33 +401,103 @@ static bool arm_spe__is_memory_event(enum arm_spe_sample_type type)
 	return false;
 }
 
-static u64 arm_spe__synth_data_source(const struct arm_spe_record *record)
-{
-	union perf_mem_data_src	data_src = { 0 };
+static const struct midr_range neoverse_spe[] = {
+	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1),
+	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2),
+	{},
+};
 
-	if (record->op == ARM_SPE_LD)
-		data_src.mem_op = PERF_MEM_OP_LOAD;
-	else
-		data_src.mem_op = PERF_MEM_OP_STORE;
 
+static void arm_spe__synth_data_source_neoverse(const struct arm_spe_record *record,
+						union perf_mem_data_src *data_src)
+{
+	switch (record->source) {
+	case ARM_SPE_NV_L1D:
+		data_src->mem_lvl = PERF_MEM_LVL_HIT;
+		data_src->mem_lvl_num = PERF_MEM_LVLNUM_L1;
+		break;
+	case ARM_SPE_NV_L2:
+		data_src->mem_lvl = PERF_MEM_LVL_HIT;
+		data_src->mem_lvl_num = PERF_MEM_LVLNUM_L2;
+		break;
+	case ARM_SPE_NV_PEER_CORE:
+		data_src->mem_lvl = PERF_MEM_LVL_HIT;
+		data_src->mem_snoop = PERF_MEM_SNOOP_HITM;
+		data_src->mem_lvl_num = PERF_MEM_LVLNUM_ANY_CACHE;
+		break;
+	/*
+	 * We don't know if this is L1, L2, or even L3 (for the cases the system
+	 * has an L3, but we do know it was a cache-2-cache transfer, so set
+	 * SNOOP_HITM
+	 */
+	case ARM_SPE_NV_LCL_CLSTR:
+	case ARM_SPE_NV_PEER_CLSTR:
+		data_src->mem_lvl = PERF_MEM_LVL_HIT;
+		data_src->mem_snoop = PERF_MEM_SNOOP_HITM;
+		data_src->mem_lvl_num = PERF_MEM_LVLNUM_ANY_CACHE;
+		break;
+	/*
+	 * System cache is assumed to be L4, as cluster cache (if it exists)
+	 * would be L3 cache on Neoverse platforms
+	 */
+	case ARM_SPE_NV_SYS_CACHE:
+		data_src->mem_lvl = PERF_MEM_LVL_HIT;
+		data_src->mem_lvl_num = PERF_MEM_LVLNUM_L4;
+		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_snoop = PERF_MEM_SNOOP_HITM;
+		data_src->mem_remote = PERF_MEM_REMOTE_REMOTE;
+		break;
+	case ARM_SPE_NV_DRAM:
+		data_src->mem_lvl = PERF_MEM_LVL_HIT;
+		data_src->mem_lvl_num = PERF_MEM_LVLNUM_RAM;
+		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
+		data_src.mem_op = PERF_MEM_OP_STORE;
+
+	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;
@@ -446,7 +518,7 @@ 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) {
@@ -796,6 +868,10 @@ static int arm_spe_process_event(struct perf_session *session,
 	u64 timestamp;
 	struct arm_spe *spe = container_of(session->auxtrace,
 			struct arm_spe, auxtrace);
+	const char *cpuid = perf_env__cpuid(session->evlist->env);
+	u64 midr = strtol(cpuid, NULL, 16);
+
+	spe->midr = midr;
 
 	if (dump_trace)
 		return 0;
-- 
2.32.0




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