1 files changed, 314 insertions, 0 deletions
diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
new file mode 100644
index 000000000000..04f89120b323
--- /dev/null
+++ b/tools/perf/util/bpf_counter.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2019 Facebook */
+
+#include <assert.h>
+#include <limits.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <linux/err.h>
+#include <linux/zalloc.h>
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
+#include <bpf/libbpf.h>
+
+#include "bpf_counter.h"
+#include "counts.h"
+#include "debug.h"
+#include "evsel.h"
+#include "target.h"
+
+#include "bpf_skel/bpf_prog_profiler.skel.h"
+
+static inline void *u64_to_ptr(__u64 ptr)
+{
+	return (void *)(unsigned long)ptr;
+}
+
+static void set_max_rlimit(void)
+{
+	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
+
+	setrlimit(RLIMIT_MEMLOCK, &rinf);
+}
+
+static struct bpf_counter *bpf_counter_alloc(void)
+{
+	struct bpf_counter *counter;
+
+	counter = zalloc(sizeof(*counter));
+	if (counter)
+		INIT_LIST_HEAD(&counter->list);
+	return counter;
+}
+
+static int bpf_program_profiler__destroy(struct evsel *evsel)
+{
+	struct bpf_counter *counter, *tmp;
+
+	list_for_each_entry_safe(counter, tmp,
+				 &evsel->bpf_counter_list, list) {
+		list_del_init(&counter->list);
+		bpf_prog_profiler_bpf__destroy(counter->skel);
+		free(counter);
+	}
+	assert(list_empty(&evsel->bpf_counter_list));
+
+	return 0;
+}
+
+static char *bpf_target_prog_name(int tgt_fd)
+{
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_func_info *func_info;
+	const struct btf_type *t;
+	char *name = NULL;
+	struct btf *btf;
+
+	info_linear = bpf_program__get_prog_info_linear(
+		tgt_fd, 1UL << BPF_PROG_INFO_FUNC_INFO);
+	if (IS_ERR_OR_NULL(info_linear)) {
+		pr_debug("failed to get info_linear for prog FD %d\n", tgt_fd);
+		return NULL;
+	}
+
+	if (info_linear->info.btf_id == 0 ||
+	    btf__get_from_id(info_linear->info.btf_id, &btf)) {
+		pr_debug("prog FD %d doesn't have valid btf\n", tgt_fd);
+		goto out;
+	}
+
+	func_info = u64_to_ptr(info_linear->info.func_info);
+	t = btf__type_by_id(btf, func_info[0].type_id);
+	if (!t) {
+		pr_debug("btf %d doesn't have type %d\n",
+			 info_linear->info.btf_id, func_info[0].type_id);
+		goto out;
+	}
+	name = strdup(btf__name_by_offset(btf, t->name_off));
+out:
+	free(info_linear);
+	return name;
+}
+
+static int bpf_program_profiler_load_one(struct evsel *evsel, u32 prog_id)
+{
+	struct bpf_prog_profiler_bpf *skel;
+	struct bpf_counter *counter;
+	struct bpf_program *prog;
+	char *prog_name;
+	int prog_fd;
+	int err;
+
+	prog_fd = bpf_prog_get_fd_by_id(prog_id);
+	if (prog_fd < 0) {
+		pr_err("Failed to open fd for bpf prog %u\n", prog_id);
+		return -1;
+	}
+	counter = bpf_counter_alloc();
+	if (!counter) {
+		close(prog_fd);
+		return -1;
+	}
+
+	skel = bpf_prog_profiler_bpf__open();
+	if (!skel) {
+		pr_err("Failed to open bpf skeleton\n");
+		goto err_out;
+	}
+
+	skel->rodata->num_cpu = evsel__nr_cpus(evsel);
+
+	bpf_map__resize(skel->maps.events, evsel__nr_cpus(evsel));
+	bpf_map__resize(skel->maps.fentry_readings, 1);
+	bpf_map__resize(skel->maps.accum_readings, 1);
+
+	prog_name = bpf_target_prog_name(prog_fd);
+	if (!prog_name) {
+		pr_err("Failed to get program name for bpf prog %u. Does it have BTF?\n", prog_id);
+		goto err_out;
+	}
+
+	bpf_object__for_each_program(prog, skel->obj) {
+		err = bpf_program__set_attach_target(prog, prog_fd, prog_name);
+		if (err) {
+			pr_err("bpf_program__set_attach_target failed.\n"
+			       "Does bpf prog %u have BTF?\n", prog_id);
+			goto err_out;
+		}
+	}
+	set_max_rlimit();
+	err = bpf_prog_profiler_bpf__load(skel);
+	if (err) {
+		pr_err("bpf_prog_profiler_bpf__load failed\n");
+		goto err_out;
+	}
+
+	assert(skel != NULL);
+	counter->skel = skel;
+	list_add(&counter->list, &evsel->bpf_counter_list);
+	close(prog_fd);
+	return 0;
+err_out:
+	bpf_prog_profiler_bpf__destroy(skel);
+	free(counter);
+	close(prog_fd);
+	return -1;
+}
+
+static int bpf_program_profiler__load(struct evsel *evsel, struct target *target)
+{
+	char *bpf_str, *bpf_str_, *tok, *saveptr = NULL, *p;
+	u32 prog_id;
+	int ret;
+
+	bpf_str_ = bpf_str = strdup(target->bpf_str);
+	if (!bpf_str)
+		return -1;
+
+	while ((tok = strtok_r(bpf_str, ",", &saveptr)) != NULL) {
+		prog_id = strtoul(tok, &p, 10);
+		if (prog_id == 0 || prog_id == UINT_MAX ||
+		    (*p != '\0' && *p != ',')) {
+			pr_err("Failed to parse bpf prog ids %s\n",
+			       target->bpf_str);
+			return -1;
+		}
+
+		ret = bpf_program_profiler_load_one(evsel, prog_id);
+		if (ret) {
+			bpf_program_profiler__destroy(evsel);
+			free(bpf_str_);
+			return -1;
+		}
+		bpf_str = NULL;
+	}
+	free(bpf_str_);
+	return 0;
+}
+
+static int bpf_program_profiler__enable(struct evsel *evsel)
+{
+	struct bpf_counter *counter;
+	int ret;
+
+	list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
+		assert(counter->skel != NULL);
+		ret = bpf_prog_profiler_bpf__attach(counter->skel);
+		if (ret) {
+			bpf_program_profiler__destroy(evsel);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static int bpf_program_profiler__read(struct evsel *evsel)
+{
+	// perf_cpu_map uses /sys/devices/system/cpu/online
+	int num_cpu = evsel__nr_cpus(evsel);
+	// BPF_MAP_TYPE_PERCPU_ARRAY uses /sys/devices/system/cpu/possible
+	// Sometimes possible > online, like on a Ryzen 3900X that has 24
+	// threads but its possible showed 0-31 -acme
+	int num_cpu_bpf = libbpf_num_possible_cpus();
+	struct bpf_perf_event_value values[num_cpu_bpf];
+	struct bpf_counter *counter;
+	int reading_map_fd;
+	__u32 key = 0;
+	int err, cpu;
+
+	if (list_empty(&evsel->bpf_counter_list))
+		return -EAGAIN;
+
+	for (cpu = 0; cpu < num_cpu; cpu++) {
+		perf_counts(evsel->counts, cpu, 0)->val = 0;
+		perf_counts(evsel->counts, cpu, 0)->ena = 0;
+		perf_counts(evsel->counts, cpu, 0)->run = 0;
+	}
+	list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
+		struct bpf_prog_profiler_bpf *skel = counter->skel;
+
+		assert(skel != NULL);
+		reading_map_fd = bpf_map__fd(skel->maps.accum_readings);
+
+		err = bpf_map_lookup_elem(reading_map_fd, &key, values);
+		if (err) {
+			pr_err("failed to read value\n");
+			return err;
+		}
+
+		for (cpu = 0; cpu < num_cpu; cpu++) {
+			perf_counts(evsel->counts, cpu, 0)->val += values[cpu].counter;
+			perf_counts(evsel->counts, cpu, 0)->ena += values[cpu].enabled;
+			perf_counts(evsel->counts, cpu, 0)->run += values[cpu].running;
+		}
+	}
+	return 0;
+}
+
+static int bpf_program_profiler__install_pe(struct evsel *evsel, int cpu,
+					    int fd)
+{
+	struct bpf_prog_profiler_bpf *skel;
+	struct bpf_counter *counter;
+	int ret;
+
+	list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
+		skel = counter->skel;
+		assert(skel != NULL);
+
+		ret = bpf_map_update_elem(bpf_map__fd(skel->maps.events),
+					  &cpu, &fd, BPF_ANY);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+struct bpf_counter_ops bpf_program_profiler_ops = {
+	.load       = bpf_program_profiler__load,
+	.enable	    = bpf_program_profiler__enable,
+	.read       = bpf_program_profiler__read,
+	.destroy    = bpf_program_profiler__destroy,
+	.install_pe = bpf_program_profiler__install_pe,
+};
+
+int bpf_counter__install_pe(struct evsel *evsel, int cpu, int fd)
+{
+	if (list_empty(&evsel->bpf_counter_list))
+		return 0;
+	return evsel->bpf_counter_ops->install_pe(evsel, cpu, fd);
+}
+
+int bpf_counter__load(struct evsel *evsel, struct target *target)
+{
+	if (target__has_bpf(target))
+		evsel->bpf_counter_ops = &bpf_program_profiler_ops;
+
+	if (evsel->bpf_counter_ops)
+		return evsel->bpf_counter_ops->load(evsel, target);
+	return 0;
+}
+
+int bpf_counter__enable(struct evsel *evsel)
+{
+	if (list_empty(&evsel->bpf_counter_list))
+		return 0;
+	return evsel->bpf_counter_ops->enable(evsel);
+}
+
+int bpf_counter__read(struct evsel *evsel)
+{
+	if (list_empty(&evsel->bpf_counter_list))
+		return -EAGAIN;
+	return evsel->bpf_counter_ops->read(evsel);
+}
+
+void bpf_counter__destroy(struct evsel *evsel)
+{
+	if (list_empty(&evsel->bpf_counter_list))
+		return;
+	evsel->bpf_counter_ops->destroy(evsel);
+	evsel->bpf_counter_ops = NULL;
+}