// SPDX-License-Identifier: GPL-2.0
/*
 * HiSilicon PCIe Trace and Tuning (PTT) support
 * Copyright (c) 2022 HiSilicon Technologies Co., Ltd.
 */

#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> // page_size
#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/hisi-ptt.h"
#include "../../../util/pmu.h"
#include "../../../util/record.h"
#include "../../../util/session.h"
#include "../../../util/tsc.h"

#define KiB(x) ((x) * 1024)
#define MiB(x) ((x) * 1024 * 1024)

struct hisi_ptt_recording {
        struct auxtrace_record  itr;
        struct perf_pmu *hisi_ptt_pmu;
        struct evlist *evlist;
};

static size_t
hisi_ptt_info_priv_size(struct auxtrace_record *itr __maybe_unused,
                        struct evlist *evlist __maybe_unused)
{
        return HISI_PTT_AUXTRACE_PRIV_SIZE;
}

static int hisi_ptt_info_fill(struct auxtrace_record *itr,
                              struct perf_session *session,
                              struct perf_record_auxtrace_info *auxtrace_info,
                              size_t priv_size)
{
        struct hisi_ptt_recording *pttr =
                        container_of(itr, struct hisi_ptt_recording, itr);
        struct perf_pmu *hisi_ptt_pmu = pttr->hisi_ptt_pmu;

        if (priv_size != HISI_PTT_AUXTRACE_PRIV_SIZE)
                return -EINVAL;

        if (!session->evlist->core.nr_mmaps)
                return -EINVAL;

        auxtrace_info->type = PERF_AUXTRACE_HISI_PTT;
        auxtrace_info->priv[0] = hisi_ptt_pmu->type;

        return 0;
}

static int hisi_ptt_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 for HISI PTT: must be at least %zuKiB and a power of 2\n",
                               min_sz / 1024);
                        return -EINVAL;
                }
        }

        return 0;
}

static int hisi_ptt_recording_options(struct auxtrace_record *itr,
                                      struct evlist *evlist,
                                      struct record_opts *opts)
{
        struct hisi_ptt_recording *pttr =
                        container_of(itr, struct hisi_ptt_recording, itr);
        struct perf_pmu *hisi_ptt_pmu = pttr->hisi_ptt_pmu;
        struct evsel *evsel, *hisi_ptt_evsel = NULL;
        struct evsel *tracking_evsel;
        int err;

        pttr->evlist = evlist;
        evlist__for_each_entry(evlist, evsel) {
                if (evsel->core.attr.type == hisi_ptt_pmu->type) {
                        if (hisi_ptt_evsel) {
                                pr_err("There may be only one " HISI_PTT_PMU_NAME "x event\n");
                                return -EINVAL;
                        }
                        evsel->core.attr.freq = 0;
                        evsel->core.attr.sample_period = 1;
                        evsel->needs_auxtrace_mmap = true;
                        hisi_ptt_evsel = evsel;
                        opts->full_auxtrace = true;
                }
        }

        err = hisi_ptt_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, hisi_ptt_evsel);
        evsel__set_sample_bit(hisi_ptt_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 hisi_ptt_reference(struct auxtrace_record *itr __maybe_unused)
{
        return rdtsc();
}

static void hisi_ptt_recording_free(struct auxtrace_record *itr)
{
        struct hisi_ptt_recording *pttr =
                        container_of(itr, struct hisi_ptt_recording, itr);

        free(pttr);
}

struct auxtrace_record *hisi_ptt_recording_init(int *err,
                                                struct perf_pmu *hisi_ptt_pmu)
{
        struct hisi_ptt_recording *pttr;

        if (!hisi_ptt_pmu) {
                *err = -ENODEV;
                return NULL;
        }

        pttr = zalloc(sizeof(*pttr));
        if (!pttr) {
                *err = -ENOMEM;
                return NULL;
        }

        pttr->hisi_ptt_pmu = hisi_ptt_pmu;
        pttr->itr.recording_options = hisi_ptt_recording_options;
        pttr->itr.info_priv_size = hisi_ptt_info_priv_size;
        pttr->itr.info_fill = hisi_ptt_info_fill;
        pttr->itr.free = hisi_ptt_recording_free;
        pttr->itr.reference = hisi_ptt_reference;
        pttr->itr.read_finish = auxtrace_record__read_finish;
        pttr->itr.alignment = 0;

        *err = 0;
        return &pttr->itr;
}