[PATCH v5 12/14] perf tools: Add RISC-V trace PMU record capabilities

Introduce the required auxiliary API functions allowing the perf core
to interact with gtrace perf driver. On RISC-V systems the gtrace
PMU uses the RISC-V E-Trace components and optionally an ATB Bridge
component for connecting to ARM-side sinks, if it is present on the SoC.

Co-developed-by: Anup Patel <[email protected]>
Signed-off-by: Anup Patel <[email protected]>
Signed-off-by: Mayuresh Chitale <[email protected]>
Reviewed-by: Nutty Liu <[email protected]>
Reviewed-by: Adrian Hunter <[email protected]>
---
 tools/perf/arch/riscv/util/Build      |   1 +
 tools/perf/arch/riscv/util/auxtrace.c | 217 ++++++++++++++++++++++++++
 tools/perf/util/auxtrace.c            |   1 +
 tools/perf/util/auxtrace.h            |   1 +
 tools/perf/util/gtrace.h              |  12 ++
 5 files changed, 232 insertions(+)
 create mode 100644 tools/perf/arch/riscv/util/auxtrace.c
 create mode 100644 tools/perf/util/gtrace.h

diff --git a/tools/perf/arch/riscv/util/Build b/tools/perf/arch/riscv/util/Build
index 2328fb9a30a3..e07d5525ece6 100644
--- a/tools/perf/arch/riscv/util/Build
+++ b/tools/perf/arch/riscv/util/Build
@@ -1 +1,2 @@
 perf-util-y += header.o
+perf-util-y += auxtrace.o
diff --git a/tools/perf/arch/riscv/util/auxtrace.c b/tools/perf/arch/riscv/util/auxtrace.c
new file mode 100644
index 000000000000..39c31be9f896
--- /dev/null
+++ b/tools/perf/arch/riscv/util/auxtrace.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Risc-V E-Trace support
+ * Copyright (c) 2026 Qualcomm Technologies, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <linux/log2.h>
+#include <linux/zalloc.h>
+#include <errno.h>
+#include <time.h>
+
+#include <internal/lib.h>
+#include "../../../util/auxtrace.h"
+#include "../../../util/cpumap.h"
+#include "../../../util/debug.h"
+#include "../../../util/event.h"
+#include "../../../util/evlist.h"
+#include "../../../util/evsel.h"
+#include "../../../util/pmu.h"
+#include "../../../util/record.h"
+#include "../../../util/session.h"
+
+
+#define GTRACE_PMU_NAME	"gtrace"
+#define GTRACE_AUXTRACE_PRIV_SIZE	sizeof(u64)
+#define KiB(x)	((x) * 1024)
+#define MiB(x)	((x) * 1024 * 1024)
+
+struct rvtrace_recording {
+	struct auxtrace_record	itr;
+	struct perf_pmu *rvtrace_pmu;
+	struct evlist *evlist;
+};
+
+static size_t rvtrace_info_priv_size(struct auxtrace_record *itr __maybe_unused,
+				     struct evlist *evlist __maybe_unused)
+{
+	return GTRACE_AUXTRACE_PRIV_SIZE;
+}
+
+static int rvtrace_info_fill(struct auxtrace_record *itr,
+			     struct perf_session *session __maybe_unused,
+			     struct perf_record_auxtrace_info *auxtrace_info, size_t priv_size)
+{
+	struct rvtrace_recording *ptr = container_of(itr, struct rvtrace_recording, itr);
+	struct perf_pmu *rvtrace_pmu = ptr->rvtrace_pmu;
+
+	if (priv_size != GTRACE_AUXTRACE_PRIV_SIZE)
+		return -EINVAL;
+
+	auxtrace_info->type = PERF_AUXTRACE_GTRACE;
+	auxtrace_info->priv[0] = rvtrace_pmu->type;
+
+	return 0;
+}
+
+static int rvtrace_set_auxtrace_mmap_page(struct record_opts *opts)
+{
+	bool privileged = perf_event_paranoid_check(-1);
+
+	if (!opts->full_auxtrace)
+		return 0;
+
+	if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
+		if (privileged) {
+			opts->auxtrace_mmap_pages = MiB(16) / page_size;
+		} else {
+			opts->auxtrace_mmap_pages = KiB(128) / page_size;
+			if (opts->mmap_pages == UINT_MAX)
+				opts->mmap_pages = KiB(256) / page_size;
+		}
+	}
+
+	/* Validate auxtrace_mmap_pages */
+	if (opts->auxtrace_mmap_pages) {
+		size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
+		size_t min_sz = KiB(8);
+
+		if (sz < min_sz || !is_power_of_2(sz)) {
+			pr_err("Invalid mmap size : must be at least %zuKiB and a power of 2\n",
+			       min_sz / 1024);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int rvtrace_recording_options(struct auxtrace_record *itr, struct evlist *evlist,
+				     struct record_opts *opts)
+{
+	struct rvtrace_recording *ptr = container_of(itr, struct rvtrace_recording, itr);
+	struct perf_pmu *rvtrace_pmu = ptr->rvtrace_pmu;
+	struct evsel *evsel, *rvtrace_evsel = NULL;
+	struct evsel *tracking_evsel;
+	int err;
+
+	ptr->evlist = evlist;
+	evlist__for_each_entry(evlist, evsel) {
+		if (evsel->core.attr.type == rvtrace_pmu->type) {
+			if (rvtrace_evsel) {
+				pr_err("There may be only one " GTRACE_PMU_NAME " event\n");
+				return -EINVAL;
+			}
+			evsel->core.attr.freq = 0;
+			evsel->core.attr.sample_period = 1;
+			evsel->needs_auxtrace_mmap = true;
+			rvtrace_evsel = evsel;
+			opts->full_auxtrace = true;
+		}
+	}
+
+	err = rvtrace_set_auxtrace_mmap_page(opts);
+	if (err)
+		return err;
+	/*
+	 * To obtain the auxtrace buffer file descriptor, the auxtrace event
+	 * must come first.
+	 */
+	evlist__to_front(evlist, rvtrace_evsel);
+	evsel__set_sample_bit(rvtrace_evsel, TIME);
+
+	/* Add dummy event to keep tracking */
+	err = parse_event(evlist, "dummy:u");
+	if (err)
+		return err;
+
+	tracking_evsel = evlist__last(evlist);
+	evlist__set_tracking_event(evlist, tracking_evsel);
+
+	tracking_evsel->core.attr.freq = 0;
+	tracking_evsel->core.attr.sample_period = 1;
+	evsel__set_sample_bit(tracking_evsel, TIME);
+
+	return 0;
+}
+
+static u64 rvtrace_reference(struct auxtrace_record *itr __maybe_unused)
+{
+	return 0;
+}
+
+static void rvtrace_recording_free(struct auxtrace_record *itr)
+{
+	struct rvtrace_recording *ptr = container_of(itr, struct rvtrace_recording, itr);
+
+	free(ptr);
+}
+
+static struct auxtrace_record *rvtrace_recording_init(int *err, struct perf_pmu *rvtrace_pmu)
+{
+	struct rvtrace_recording *ptr;
+
+	if (!rvtrace_pmu) {
+		*err = -ENODEV;
+		return NULL;
+	}
+
+	ptr = zalloc(sizeof(*ptr));
+	if (!ptr) {
+		*err = -ENOMEM;
+		return NULL;
+	}
+
+	ptr->rvtrace_pmu = rvtrace_pmu;
+	ptr->itr.recording_options = rvtrace_recording_options;
+	ptr->itr.info_priv_size = rvtrace_info_priv_size;
+	ptr->itr.info_fill = rvtrace_info_fill;
+	ptr->itr.free = rvtrace_recording_free;
+	ptr->itr.reference = rvtrace_reference;
+	ptr->itr.read_finish = auxtrace_record__read_finish;
+	ptr->itr.alignment = 0;
+
+	*err = 0;
+	return &ptr->itr;
+}
+
+static struct perf_pmu *find_pmu_for_event(struct perf_pmu **pmus,
+					   int pmu_nr, struct evsel *evsel)
+{
+	int i;
+
+	if (!pmus)
+		return NULL;
+
+	for (i = 0; i < pmu_nr; i++) {
+		if (evsel->core.attr.type == pmus[i]->type)
+			return pmus[i];
+	}
+
+	return NULL;
+}
+
+struct auxtrace_record *auxtrace_record__init(struct evlist *evlist, int *err)
+{
+	struct perf_pmu	*rvtrace_pmu = NULL;
+	struct perf_pmu *found_pmu = NULL;
+	struct evsel *evsel;
+
+	if (!evlist)
+		return NULL;
+
+	rvtrace_pmu = perf_pmus__find(GTRACE_PMU_NAME);
+	evlist__for_each_entry(evlist, evsel) {
+		if (rvtrace_pmu && !found_pmu)
+			found_pmu = find_pmu_for_event(&rvtrace_pmu, 1, evsel);
+	}
+
+	if (found_pmu)
+		return rvtrace_recording_init(err, rvtrace_pmu);
+
+	*err = 0;
+	return NULL;
+}
diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index 4cd2caf54015..d7f27ca15b81 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -1427,6 +1427,7 @@ int perf_event__process_auxtrace_info(const struct perf_tool *tool __maybe_unuse
 	case PERF_AUXTRACE_VPA_DTL:
 		err = powerpc_vpadtl_process_auxtrace_info(event, session);
 		break;
+	case PERF_AUXTRACE_GTRACE:
 	case PERF_AUXTRACE_UNKNOWN:
 	default:
 		return -EINVAL;
diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
index 6947f3f284c0..42b1481ec894 100644
--- a/tools/perf/util/auxtrace.h
+++ b/tools/perf/util/auxtrace.h
@@ -46,6 +46,7 @@ enum auxtrace_type {
 	PERF_AUXTRACE_S390_CPUMSF,
 	PERF_AUXTRACE_HISI_PTT,
 	PERF_AUXTRACE_VPA_DTL,
+	PERF_AUXTRACE_GTRACE,
 };
 
 enum itrace_period_type {
diff --git a/tools/perf/util/gtrace.h b/tools/perf/util/gtrace.h
new file mode 100644
index 000000000000..4b87bdaf55c6
--- /dev/null
+++ b/tools/perf/util/gtrace.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2026 Qualcomm Technologies, Inc.
+ */
+
+#ifndef INCLUDE__UTIL_PERF_GTRACE_H__
+#define INCLUDE__UTIL_PERF_GTRACE_H__
+
+#define GTRACE_AUXTRACE_PRIV_SIZE      sizeof(u64)
+
+#endif
+
-- 
2.43.0


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