// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * RDMA Transport Layer
 *
 * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
 * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
 * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
 */
#undef pr_fmt
#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt

#include "rtrs-clt.h"

void rtrs_clt_update_wc_stats(struct rtrs_clt_con *con)
{
        struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
        struct rtrs_clt_stats *stats = clt_path->stats;
        struct rtrs_clt_stats_pcpu *s;
        int cpu;

        cpu = raw_smp_processor_id();
        s = get_cpu_ptr(stats->pcpu_stats);
        if (con->cpu != cpu) {
                s->cpu_migr.to++;

                /* Careful here, override s pointer */
                s = per_cpu_ptr(stats->pcpu_stats, con->cpu);
                atomic_inc(&s->cpu_migr.from);
        }
        put_cpu_ptr(stats->pcpu_stats);
}

void rtrs_clt_inc_failover_cnt(struct rtrs_clt_stats *stats)
{
        this_cpu_inc(stats->pcpu_stats->rdma.failover_cnt);
}

int rtrs_clt_stats_migration_from_cnt_to_str(struct rtrs_clt_stats *stats, char *buf)
{
        struct rtrs_clt_stats_pcpu *s;

        size_t used;
        int cpu;

        used = 0;
        for_each_possible_cpu(cpu) {
                s = per_cpu_ptr(stats->pcpu_stats, cpu);
                used += sysfs_emit_at(buf, used, "%d ",
                                  atomic_read(&s->cpu_migr.from));
        }

        used += sysfs_emit_at(buf, used, "\n");

        return used;
}

int rtrs_clt_stats_migration_to_cnt_to_str(struct rtrs_clt_stats *stats, char *buf)
{
        struct rtrs_clt_stats_pcpu *s;

        size_t used;
        int cpu;

        used = 0;
        for_each_possible_cpu(cpu) {
                s = per_cpu_ptr(stats->pcpu_stats, cpu);
                used += sysfs_emit_at(buf, used, "%d ", s->cpu_migr.to);
        }

        used += sysfs_emit_at(buf, used, "\n");

        return used;
}

int rtrs_clt_stats_reconnects_to_str(struct rtrs_clt_stats *stats, char *buf)
{
        return sysfs_emit(buf, "%d %d\n", stats->reconnects.successful_cnt,
                          stats->reconnects.fail_cnt);
}

ssize_t rtrs_clt_stats_rdma_to_str(struct rtrs_clt_stats *stats, char *page)
{
        struct rtrs_clt_stats_rdma sum;
        struct rtrs_clt_stats_rdma *r;
        int cpu;

        memset(&sum, 0, sizeof(sum));

        for_each_possible_cpu(cpu) {
                r = &per_cpu_ptr(stats->pcpu_stats, cpu)->rdma;

                sum.dir[READ].cnt         += r->dir[READ].cnt;
                sum.dir[READ].size_total  += r->dir[READ].size_total;
                sum.dir[WRITE].cnt        += r->dir[WRITE].cnt;
                sum.dir[WRITE].size_total += r->dir[WRITE].size_total;
                sum.failover_cnt          += r->failover_cnt;
        }

        return sysfs_emit(page, "%llu %llu %llu %llu %u %llu\n",
                         sum.dir[READ].cnt, sum.dir[READ].size_total,
                         sum.dir[WRITE].cnt, sum.dir[WRITE].size_total,
                         atomic_read(&stats->inflight), sum.failover_cnt);
}

ssize_t rtrs_clt_reset_all_help(struct rtrs_clt_stats *s, char *page)
{
        return sysfs_emit(page, "echo 1 to reset all statistics\n");
}

int rtrs_clt_reset_rdma_stats(struct rtrs_clt_stats *stats, bool enable)
{
        struct rtrs_clt_stats_pcpu *s;
        int cpu;

        if (!enable)
                return -EINVAL;

        for_each_possible_cpu(cpu) {
                s = per_cpu_ptr(stats->pcpu_stats, cpu);
                memset(&s->rdma, 0, sizeof(s->rdma));
        }

        return 0;
}

int rtrs_clt_reset_cpu_migr_stats(struct rtrs_clt_stats *stats, bool enable)
{
        struct rtrs_clt_stats_pcpu *s;
        int cpu;

        if (!enable)
                return -EINVAL;

        for_each_possible_cpu(cpu) {
                s = per_cpu_ptr(stats->pcpu_stats, cpu);
                memset(&s->cpu_migr, 0, sizeof(s->cpu_migr));
        }

        return 0;
}

int rtrs_clt_reset_reconnects_stat(struct rtrs_clt_stats *stats, bool enable)
{
        if (!enable)
                return -EINVAL;

        memset(&stats->reconnects, 0, sizeof(stats->reconnects));

        return 0;
}

int rtrs_clt_reset_all_stats(struct rtrs_clt_stats *s, bool enable)
{
        if (enable) {
                rtrs_clt_reset_rdma_stats(s, enable);
                rtrs_clt_reset_cpu_migr_stats(s, enable);
                rtrs_clt_reset_reconnects_stat(s, enable);
                atomic_set(&s->inflight, 0);
                return 0;
        }

        return -EINVAL;
}

static inline void rtrs_clt_update_rdma_stats(struct rtrs_clt_stats *stats,
                                               size_t size, int d)
{
        this_cpu_inc(stats->pcpu_stats->rdma.dir[d].cnt);
        this_cpu_add(stats->pcpu_stats->rdma.dir[d].size_total, size);
}

void rtrs_clt_update_all_stats(struct rtrs_clt_io_req *req, int dir)
{
        struct rtrs_clt_con *con = req->con;
        struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
        struct rtrs_clt_stats *stats = clt_path->stats;
        unsigned int len;

        len = req->usr_len + req->data_len;
        rtrs_clt_update_rdma_stats(stats, len, dir);
        if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
                atomic_inc(&stats->inflight);
}

int rtrs_clt_init_stats(struct rtrs_clt_stats *stats)
{
        stats->pcpu_stats = alloc_percpu(typeof(*stats->pcpu_stats));
        if (!stats->pcpu_stats)
                return -ENOMEM;

        /*
         * successful_cnt will be set to 0 after session
         * is established for the first time
         */
        stats->reconnects.successful_cnt = -1;

        return 0;
}