#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <linux/zalloc.h>

#include "../../util/evlist.h"
#include "../../util/auxtrace.h"
#include "../../util/evsel.h"
#include "../../util/record.h"

#define PERF_EVENT_CPUM_SF              0xB0000 /* Event: Basic-sampling */
#define PERF_EVENT_CPUM_SF_DIAG         0xBD000 /* Event: Combined-sampling */
#define DEFAULT_AUX_PAGES               128
#define DEFAULT_FREQ                    4000

static void cpumsf_free(struct auxtrace_record *itr)
{
        free(itr);
}

static size_t cpumsf_info_priv_size(struct auxtrace_record *itr __maybe_unused,
                                    struct evlist *evlist __maybe_unused)
{
        return 0;
}

static int
cpumsf_info_fill(struct auxtrace_record *itr __maybe_unused,
                 struct perf_session *session __maybe_unused,
                 struct perf_record_auxtrace_info *auxtrace_info __maybe_unused,
                 size_t priv_size __maybe_unused)
{
        auxtrace_info->type = PERF_AUXTRACE_S390_CPUMSF;
        return 0;
}

static unsigned long
cpumsf_reference(struct auxtrace_record *itr __maybe_unused)
{
        return 0;
}

static int
cpumsf_recording_options(struct auxtrace_record *ar __maybe_unused,
                         struct evlist *evlist __maybe_unused,
                         struct record_opts *opts)
{
        unsigned int factor = 1;
        unsigned int pages;

        opts->full_auxtrace = true;

        /*
         * The AUX buffer size should be set properly to avoid
         * overflow of samples if it is not set explicitly.
         * DEFAULT_AUX_PAGES is an proper size when sampling frequency
         * is DEFAULT_FREQ. It is expected to hold about 1/2 second
         * of sampling data. The size used for AUX buffer will scale
         * according to the specified frequency and DEFAULT_FREQ.
         */
        if (!opts->auxtrace_mmap_pages) {
                if (opts->user_freq != UINT_MAX)
                        factor = (opts->user_freq + DEFAULT_FREQ
                                  - 1) / DEFAULT_FREQ;
                pages = DEFAULT_AUX_PAGES * factor;
                opts->auxtrace_mmap_pages = roundup_pow_of_two(pages);
        }

        return 0;
}

static int
cpumsf_parse_snapshot_options(struct auxtrace_record *itr __maybe_unused,
                              struct record_opts *opts __maybe_unused,
                              const char *str __maybe_unused)
{
        return 0;
}

/*
 * auxtrace_record__init is called when perf record
 * check if the event really need auxtrace
 */
struct auxtrace_record *auxtrace_record__init(struct evlist *evlist,
                                              int *err)
{
        struct auxtrace_record *aux;
        struct evsel *pos;
        int diagnose = 0;

        *err = 0;
        if (evlist->core.nr_entries == 0)
                return NULL;

        evlist__for_each_entry(evlist, pos) {
                if (pos->core.attr.config == PERF_EVENT_CPUM_SF_DIAG) {
                        diagnose = 1;
                        pos->needs_auxtrace_mmap = true;
                        break;
                }
        }

        if (!diagnose)
                return NULL;

        /* sampling in diagnose mode. alloc aux buffer */
        aux = zalloc(sizeof(*aux));
        if (aux == NULL) {
                *err = -ENOMEM;
                return NULL;
        }

        aux->parse_snapshot_options = cpumsf_parse_snapshot_options;
        aux->recording_options = cpumsf_recording_options;
        aux->info_priv_size = cpumsf_info_priv_size;
        aux->info_fill = cpumsf_info_fill;
        aux->free = cpumsf_free;
        aux->reference = cpumsf_reference;

        return aux;
}