// SPDX-License-Identifier: GPL-2.0
/*
 * Memory Bandwidth Monitoring (MBM) test
 *
 * Copyright (C) 2018 Intel Corporation
 *
 * Authors:
 *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
 *    Fenghua Yu <fenghua.yu@intel.com>
 */
#include "resctrl.h"

#define RESULT_FILE_NAME        "result_mbm"
#define MAX_DIFF_PERCENT        8
#define NUM_OF_RUNS             5

static int
show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, size_t span)
{
        unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
        long avg_bw_imc = 0, avg_bw_resc = 0;
        int runs, ret, avg_diff_per;
        float avg_diff = 0;

        for (runs = 0; runs < NUM_OF_RUNS; runs++) {
                sum_bw_imc += bw_imc[runs];
                sum_bw_resc += bw_resc[runs];
        }

        avg_bw_imc = sum_bw_imc / NUM_OF_RUNS;
        avg_bw_resc = sum_bw_resc / NUM_OF_RUNS;
        avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
        avg_diff_per = (int)(avg_diff * 100);

        ret = avg_diff_per > MAX_DIFF_PERCENT;
        ksft_print_msg("%s Check MBM diff within %d%%\n",
                       ret ? "Fail:" : "Pass:", MAX_DIFF_PERCENT);
        ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
        if (span)
                ksft_print_msg("Span (MB): %zu\n", span / MB);
        ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
        ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);

        return ret;
}

static int check_results(size_t span)
{
        unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
        char temp[1024], *token_array[8];
        char output[] = RESULT_FILE_NAME;
        int runs, ret;
        FILE *fp;

        ksft_print_msg("Checking for pass/fail\n");

        fp = fopen(output, "r");
        if (!fp) {
                ksft_perror(output);

                return -1;
        }

        runs = 0;
        while (fgets(temp, sizeof(temp), fp)) {
                char *token = strtok(temp, ":\t");
                int i = 0;

                while (token) {
                        token_array[i++] = token;
                        token = strtok(NULL, ":\t");
                }

                bw_resc[runs] = strtoul(token_array[5], NULL, 0);
                bw_imc[runs] = strtoul(token_array[3], NULL, 0);
                runs++;
        }

        ret = show_bw_info(bw_imc, bw_resc, span);

        fclose(fp);

        return ret;
}

static int mbm_init(const struct resctrl_val_param *param, int domain_id)
{
        int ret;

        ret = initialize_read_mem_bw_imc();
        if (ret)
                return ret;

        initialize_mem_bw_resctrl(param, domain_id);

        return 0;
}

static int mbm_setup(const struct resctrl_test *test,
                     const struct user_params *uparams,
                     struct resctrl_val_param *p)
{
        int ret = 0;

        /* Run NUM_OF_RUNS times */
        if (p->num_of_runs >= NUM_OF_RUNS)
                return END_OF_TESTS;

        /* Set up shemata with 100% allocation on the first run. */
        if (p->num_of_runs == 0 && resctrl_resource_exists("MB"))
                ret = write_schemata(p->ctrlgrp, "100", uparams->cpu, test->resource);

        p->num_of_runs++;

        return ret;
}

static int mbm_measure(const struct user_params *uparams,
                       struct resctrl_val_param *param, pid_t bm_pid)
{
        return measure_read_mem_bw(uparams, param, bm_pid);
}

static void mbm_test_cleanup(void)
{
        remove(RESULT_FILE_NAME);
}

static int mbm_run_test(const struct resctrl_test *test, const struct user_params *uparams)
{
        struct resctrl_val_param param = {
                .ctrlgrp        = "c1",
                .filename       = RESULT_FILE_NAME,
                .init           = mbm_init,
                .setup          = mbm_setup,
                .measure        = mbm_measure,
        };
        struct fill_buf_param fill_buf = {};
        int ret;

        remove(RESULT_FILE_NAME);

        if (uparams->fill_buf) {
                fill_buf.buf_size = uparams->fill_buf->buf_size;
                fill_buf.memflush = uparams->fill_buf->memflush;
                param.fill_buf = &fill_buf;
        } else if (!uparams->benchmark_cmd[0]) {
                ssize_t buf_size;

                buf_size = get_fill_buf_size(uparams->cpu, "L3");
                if (buf_size < 0)
                        return buf_size;
                fill_buf.buf_size = buf_size;
                fill_buf.memflush = true;
                param.fill_buf = &fill_buf;
        }

        ret = resctrl_val(test, uparams, &param);
        if (ret)
                return ret;

        ret = check_results(param.fill_buf ? param.fill_buf->buf_size : 0);
        if (ret && (get_vendor() == ARCH_INTEL) && !snc_kernel_support())
                ksft_print_msg("Kernel doesn't support Sub-NUMA Clustering but it is enabled on the system.\n");

        return ret;
}

static bool mbm_feature_check(const struct resctrl_test *test)
{
        return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") &&
               resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
}

struct resctrl_test mbm_test = {
        .name = "MBM",
        .resource = "MB",
        .vendor_specific = ARCH_INTEL,
        .feature_check = mbm_feature_check,
        .run_test = mbm_run_test,
        .cleanup = mbm_test_cleanup,
};