[PATCH v6 1/7] perf vendor events arm64: Add common topdown L1 metrics

[Jing Zhang]

The metrics of topdown L1 are from ARM sbsa7.0 platform design doc[0],
D37-38, which are standard. So put them in the common file sbsa.json of
arm64, so that other cores besides n2/v2 can also be reused.

Slots may be different in each architecture, so added "#slots" literal
to get different constant for each architecture.

The value of slots comes from the register PMMIR_EL1, which I can read
in /sys/bus/event_source/device/armv8_pmuv3_*/caps/slots. PMMIR_EL1.SLOT
might read as zero if the STALL_SLOT event is not implemented or the PMU
version is lower than ID_AA64DFR0_EL1_PMUVer_V3P4.

[0] https://documentation-service.arm.com/static/60250c7395978b529036da86?token=

Signed-off-by: Jing Zhang <renyu.zj at linux.alibaba.com>
Acked-by: Ian Rogers <irogers at google.com>
---
 tools/perf/arch/arm64/util/pmu.c           | 22 ++++++++++++++++++++++
 tools/perf/pmu-events/arch/arm64/sbsa.json | 30 ++++++++++++++++++++++++++++++
 tools/perf/pmu-events/jevents.py           |  2 ++
 tools/perf/util/expr.c                     |  5 +++++
 tools/perf/util/pmu.c                      |  5 +++++
 tools/perf/util/pmu.h                      |  1 +
 6 files changed, 65 insertions(+)
 create mode 100644 tools/perf/pmu-events/arch/arm64/sbsa.json

diff --git a/tools/perf/arch/arm64/util/pmu.c b/tools/perf/arch/arm64/util/pmu.c
index 477e513..227dadb 100644
--- a/tools/perf/arch/arm64/util/pmu.c
+++ b/tools/perf/arch/arm64/util/pmu.c
@@ -3,6 +3,7 @@
 #include <internal/cpumap.h>
 #include "../../../util/cpumap.h"
 #include "../../../util/pmu.h"
+#include <api/fs/fs.h>
 
 const struct pmu_events_table *pmu_events_table__find(void)
 {
@@ -24,3 +25,24 @@ const struct pmu_events_table *pmu_events_table__find(void)
 
 	return NULL;
 }
+
+int perf_pmu__get_slots(void)
+{
+	char path[PATH_MAX];
+	unsigned long long slots = 0;
+	struct perf_pmu *pmu = NULL;
+
+	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
+		if (is_pmu_core(pmu->name))
+			break;
+	}
+	if (pmu) {
+		scnprintf(path, PATH_MAX,
+			EVENT_SOURCE_DEVICE_PATH "%s/caps/slots", pmu->name);
+		/* The value of slots is not greater than INT_MAX, but sysfs__read_int
+		 * can't read value with 0x prefix, so use sysfs__read_ull instead.
+		 */
+		sysfs__read_ull(path, &slots);
+	}
+	return (int)slots;
+}
diff --git a/tools/perf/pmu-events/arch/arm64/sbsa.json b/tools/perf/pmu-events/arch/arm64/sbsa.json
new file mode 100644
index 0000000..f678c37e
--- /dev/null
+++ b/tools/perf/pmu-events/arch/arm64/sbsa.json
@@ -0,0 +1,30 @@
+[
+    {
+        "MetricExpr": "stall_slot_frontend / (#slots * cpu_cycles)",
+        "BriefDescription": "Frontend bound L1 topdown metric",
+        "MetricGroup": "TopdownL1",
+        "MetricName": "frontend_bound",
+        "ScaleUnit": "100%"
+    },
+    {
+        "MetricExpr": "(1 - op_retired / op_spec) * (1 - stall_slot / (#slots * cpu_cycles))",
+        "BriefDescription": "Bad speculation L1 topdown metric",
+        "MetricGroup": "TopdownL1",
+        "MetricName": "bad_speculation",
+        "ScaleUnit": "100%"
+    },
+    {
+        "MetricExpr": "(op_retired / op_spec) * (1 - stall_slot / (#slots * cpu_cycles))",
+        "BriefDescription": "Retiring L1 topdown metric",
+        "MetricGroup": "TopdownL1",
+        "MetricName": "retiring",
+        "ScaleUnit": "100%"
+    },
+    {
+        "MetricExpr": "stall_slot_backend / (#slots * cpu_cycles)",
+        "BriefDescription": "Backend Bound L1 topdown metric",
+        "MetricGroup": "TopdownL1",
+        "MetricName": "backend_bound",
+        "ScaleUnit": "100%"
+    }
+]
diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index 4c398e0..0416b74 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -358,6 +358,8 @@ def preprocess_arch_std_files(archpath: str) -> None:
       for event in read_json_events(item.path, topic=''):
         if event.name:
           _arch_std_events[event.name.lower()] = event
+        if event.metric_name:
+          _arch_std_events[event.metric_name.lower()] = event
 
 
 def print_events_table_prefix(tblname: str) -> None:
diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index 00dcde3..3d67707 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -19,6 +19,7 @@
 #include <linux/zalloc.h>
 #include <ctype.h>
 #include <math.h>
+#include "pmu.h"
 
 #ifdef PARSER_DEBUG
 extern int expr_debug;
@@ -448,6 +449,10 @@ double expr__get_literal(const char *literal, const struct expr_scanner_ctx *ctx
 		result = topology->core_cpus_lists;
 		goto out;
 	}
+	if (!strcmp("#slots", literal)) {
+		result = perf_pmu__get_slots();
+		goto out;
+	}
 
 	pr_err("Unrecognized literal '%s'", literal);
 out:
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 2bdeb89..d4cace2 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1993,3 +1993,8 @@ int perf_pmu__cpus_match(struct perf_pmu *pmu, struct perf_cpu_map *cpus,
 	*ucpus_ptr = unmatched_cpus;
 	return 0;
 }
+
+int __weak perf_pmu__get_slots(void)
+{
+	return 0;
+}
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 69ca000..a2f7df8 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -259,4 +259,5 @@ int perf_pmu__cpus_match(struct perf_pmu *pmu, struct perf_cpu_map *cpus,
 
 char *pmu_find_real_name(const char *name);
 char *pmu_find_alias_name(const char *name);
+int perf_pmu__get_slots(void);
 #endif /* __PMU_H */
-- 
1.8.3.1