#include "evlist.h"
#include "evsel.h"
#include "cpumap.h"
#include "parse-events.h"
#include <api/fs/fs.h>
#include "util.h"
#include "cloexec.h"

typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);

static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
{
        struct perf_evlist *evlist;
        struct perf_evsel *evsel;
        unsigned long flags = perf_event_open_cloexec_flag();
        int err = -EAGAIN, fd;
        static pid_t pid = -1;

        evlist = perf_evlist__new();
        if (!evlist)
                return -ENOMEM;

        if (parse_events(evlist, str, NULL))
                goto out_delete;

        evsel = perf_evlist__first(evlist);

        while (1) {
                fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
                if (fd < 0) {
                        if (pid == -1 && errno == EACCES) {
                                pid = 0;
                                continue;
                        }
                        goto out_delete;
                }
                break;
        }
        close(fd);

        fn(evsel);

        fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
        if (fd < 0) {
                if (errno == EINVAL)
                        err = -EINVAL;
                goto out_delete;
        }
        close(fd);
        err = 0;

out_delete:
        perf_evlist__delete(evlist);
        return err;
}

static bool perf_probe_api(setup_probe_fn_t fn)
{
        const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL};
        struct cpu_map *cpus;
        int cpu, ret, i = 0;

        cpus = cpu_map__new(NULL);
        if (!cpus)
                return false;
        cpu = cpus->map[0];
        cpu_map__put(cpus);

        do {
                ret = perf_do_probe_api(fn, cpu, try[i++]);
                if (!ret)
                        return true;
        } while (ret == -EAGAIN && try[i]);

        return false;
}

static void perf_probe_sample_identifier(struct perf_evsel *evsel)
{
        evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
}

static void perf_probe_comm_exec(struct perf_evsel *evsel)
{
        evsel->attr.comm_exec = 1;
}

static void perf_probe_context_switch(struct perf_evsel *evsel)
{
        evsel->attr.context_switch = 1;
}

bool perf_can_sample_identifier(void)
{
        return perf_probe_api(perf_probe_sample_identifier);
}

static bool perf_can_comm_exec(void)
{
        return perf_probe_api(perf_probe_comm_exec);
}

bool perf_can_record_switch_events(void)
{
        return perf_probe_api(perf_probe_context_switch);
}

bool perf_can_record_cpu_wide(void)
{
        struct perf_event_attr attr = {
                .type = PERF_TYPE_SOFTWARE,
                .config = PERF_COUNT_SW_CPU_CLOCK,
                .exclude_kernel = 1,
        };
        struct cpu_map *cpus;
        int cpu, fd;

        cpus = cpu_map__new(NULL);
        if (!cpus)
                return false;
        cpu = cpus->map[0];
        cpu_map__put(cpus);

        fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
        if (fd < 0)
                return false;
        close(fd);

        return true;
}

void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts,
                         struct callchain_param *callchain)
{
        struct perf_evsel *evsel;
        bool use_sample_identifier = false;
        bool use_comm_exec;

        /*
         * Set the evsel leader links before we configure attributes,
         * since some might depend on this info.
         */
        if (opts->group)
                perf_evlist__set_leader(evlist);

        if (evlist->cpus->map[0] < 0)
                opts->no_inherit = true;

        use_comm_exec = perf_can_comm_exec();

        evlist__for_each_entry(evlist, evsel) {
                perf_evsel__config(evsel, opts, callchain);
                if (evsel->tracking && use_comm_exec)
                        evsel->attr.comm_exec = 1;
        }

        if (opts->full_auxtrace) {
                /*
                 * Need to be able to synthesize and parse selected events with
                 * arbitrary sample types, which requires always being able to
                 * match the id.
                 */
                use_sample_identifier = perf_can_sample_identifier();
                evlist__for_each_entry(evlist, evsel)
                        perf_evsel__set_sample_id(evsel, use_sample_identifier);
        } else if (evlist->nr_entries > 1) {
                struct perf_evsel *first = perf_evlist__first(evlist);

                evlist__for_each_entry(evlist, evsel) {
                        if (evsel->attr.sample_type == first->attr.sample_type)
                                continue;
                        use_sample_identifier = perf_can_sample_identifier();
                        break;
                }
                evlist__for_each_entry(evlist, evsel)
                        perf_evsel__set_sample_id(evsel, use_sample_identifier);
        }

        perf_evlist__set_id_pos(evlist);
}

static int get_max_rate(unsigned int *rate)
{
        return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
}

static int record_opts__config_freq(struct record_opts *opts)
{
        bool user_freq = opts->user_freq != UINT_MAX;
        unsigned int max_rate;

        if (opts->user_interval != ULLONG_MAX)
                opts->default_interval = opts->user_interval;
        if (user_freq)
                opts->freq = opts->user_freq;

        /*
         * User specified count overrides default frequency.
         */
        if (opts->default_interval)
                opts->freq = 0;
        else if (opts->freq) {
                opts->default_interval = opts->freq;
        } else {
                pr_err("frequency and count are zero, aborting\n");
                return -1;
        }

        if (get_max_rate(&max_rate))
                return 0;

        /*
         * User specified frequency is over current maximum.
         */
        if (user_freq && (max_rate < opts->freq)) {
                pr_err("Maximum frequency rate (%u) reached.\n"
                   "Please use -F freq option with lower value or consider\n"
                   "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
                   max_rate);
                return -1;
        }

        /*
         * Default frequency is over current maximum.
         */
        if (max_rate < opts->freq) {
                pr_warning("Lowering default frequency rate to %u.\n"
                           "Please consider tweaking "
                           "/proc/sys/kernel/perf_event_max_sample_rate.\n",
                           max_rate);
                opts->freq = max_rate;
        }

        return 0;
}

int record_opts__config(struct record_opts *opts)
{
        return record_opts__config_freq(opts);
}

bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
{
        struct perf_evlist *temp_evlist;
        struct perf_evsel *evsel;
        int err, fd, cpu;
        bool ret = false;
        pid_t pid = -1;

        temp_evlist = perf_evlist__new();
        if (!temp_evlist)
                return false;

        err = parse_events(temp_evlist, str, NULL);
        if (err)
                goto out_delete;

        evsel = perf_evlist__last(temp_evlist);

        if (!evlist || cpu_map__empty(evlist->cpus)) {
                struct cpu_map *cpus = cpu_map__new(NULL);

                cpu =  cpus ? cpus->map[0] : 0;
                cpu_map__put(cpus);
        } else {
                cpu = evlist->cpus->map[0];
        }

        while (1) {
                fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1,
                                         perf_event_open_cloexec_flag());
                if (fd < 0) {
                        if (pid == -1 && errno == EACCES) {
                                pid = 0;
                                continue;
                        }
                        goto out_delete;
                }
                break;
        }
        close(fd);
        ret = true;

out_delete:
        perf_evlist__delete(temp_evlist);
        return ret;
}