// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include "util/evlist.h"
#include "util/pmu.h"
#include "util/pmus.h"
#include "util/topdown.h"
#include "topdown.h"
#include "evsel.h"

// cmask=0, inv=0, pc=0, edge=0, umask=4, event=0
#define TOPDOWN_SLOTS           0x0400

/* Check whether there is a PMU which supports the perf metrics. */
bool topdown_sys_has_perf_metrics(void)
{
        static bool has_perf_metrics;
        static bool cached;
        struct perf_pmu *pmu;

        if (cached)
                return has_perf_metrics;

        /*
         * The perf metrics feature is a core PMU feature.
         * The PERF_TYPE_RAW type is the type of a core PMU.
         * The slots event is only available when the core PMU
         * supports the perf metrics feature.
         */
        pmu = perf_pmus__find_by_type(PERF_TYPE_RAW);
        if (pmu && perf_pmu__have_event(pmu, "slots"))
                has_perf_metrics = true;

        cached = true;
        return has_perf_metrics;
}

bool arch_is_topdown_slots(const struct evsel *evsel)
{
        return evsel->core.attr.type == PERF_TYPE_RAW &&
               evsel->core.attr.config == TOPDOWN_SLOTS &&
               evsel->core.attr.config1 == 0;
}

bool arch_is_topdown_metrics(const struct evsel *evsel)
{
        // cmask=0, inv=0, pc=0, edge=0, umask=0x80-0x87, event=0
        return evsel->core.attr.type == PERF_TYPE_RAW &&
                (evsel->core.attr.config & 0xFFFFF8FF) == 0x8000 &&
                evsel->core.attr.config1 == 0;
}

/*
 * Check whether a topdown group supports sample-read.
 *
 * Only Topdown metric supports sample-read. The slots
 * event must be the leader of the topdown group.
 */
bool arch_topdown_sample_read(struct evsel *leader)
{
        struct evsel *evsel;

        if (!evsel__sys_has_perf_metrics(leader))
                return false;

        if (!arch_is_topdown_slots(leader))
                return false;

        /*
         * If slots event as leader event but no topdown metric events
         * in group, slots event should still sample as leader.
         */
        evlist__for_each_entry(leader->evlist, evsel) {
                if (evsel->core.leader != leader->core.leader)
                        continue;
                if (evsel != leader && arch_is_topdown_metrics(evsel))
                        return true;
        }

        return false;
}

/*
 * Make a copy of the topdown metric event metric_event with the given index but
 * change its configuration to be a topdown slots event. Copying from
 * metric_event ensures modifiers are the same.
 */
int topdown_insert_slots_event(struct list_head *list, int idx, struct evsel *metric_event)
{
        struct evsel *evsel = evsel__new_idx(&metric_event->core.attr, idx);

        if (!evsel)
                return -ENOMEM;

        evsel->core.attr.config = TOPDOWN_SLOTS;
        evsel->core.cpus = perf_cpu_map__get(metric_event->core.cpus);
        evsel->core.pmu_cpus = perf_cpu_map__get(metric_event->core.pmu_cpus);
        evsel->core.is_pmu_core = true;
        evsel->pmu = metric_event->pmu;
        evsel->name = strdup("slots");
        evsel->precise_max = metric_event->precise_max;
        evsel->sample_read = metric_event->sample_read;
        evsel->weak_group = metric_event->weak_group;
        evsel->bpf_counter = metric_event->bpf_counter;
        evsel->retire_lat = metric_event->retire_lat;
        evsel__set_leader(evsel, evsel__leader(metric_event));
        list_add_tail(&evsel->core.node, list);
        return 0;
}