// SPDX-License-Identifier: GPL-2.0
/*
 * Memory Bandwidth Allocation (MBA) 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_mba"
#define NUM_OF_RUNS             5
#define MAX_DIFF_PERCENT        8
#define ALLOCATION_MAX          100
#define ALLOCATION_MIN          10
#define ALLOCATION_STEP         10

static int mba_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;
}

/*
 * Change schemata percentage from 100 to 10%. Write schemata to specified
 * con_mon grp, mon_grp in resctrl FS.
 * For each allocation, run 5 times in order to get average values.
 */
static int mba_setup(const struct resctrl_test *test,
                     const struct user_params *uparams,
                     struct resctrl_val_param *p)
{
        static unsigned int allocation = ALLOCATION_MIN;
        static int runs_per_allocation;
        char allocation_str[64];
        int ret;

        if (runs_per_allocation >= NUM_OF_RUNS)
                runs_per_allocation = 0;

        /* Only set up schemata once every NUM_OF_RUNS of allocations */
        if (runs_per_allocation++ != 0)
                return 0;

        if (allocation > ALLOCATION_MAX)
                return END_OF_TESTS;

        sprintf(allocation_str, "%d", allocation);

        ret = write_schemata(p->ctrlgrp, allocation_str, uparams->cpu, test->resource);
        if (ret < 0)
                return ret;

        allocation += ALLOCATION_STEP;

        return 0;
}

static int mba_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 bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
{
        unsigned int allocation;
        bool ret = false;
        int runs;

        ksft_print_msg("Results are displayed in (MB)\n");
        /* Memory bandwidth from 100% down to 10% */
        for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
             allocation++) {
                unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
                long avg_bw_imc, avg_bw_resc;
                int avg_diff_per;
                float avg_diff;

                for (runs = NUM_OF_RUNS * allocation;
                     runs < NUM_OF_RUNS * allocation + 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;
                if (avg_bw_imc < THROTTLE_THRESHOLD || avg_bw_resc < THROTTLE_THRESHOLD) {
                        ksft_print_msg("Bandwidth below threshold (%d MiB). Dropping results from MBA schemata %u.\n",
                                       THROTTLE_THRESHOLD,
                                       ALLOCATION_MIN + ALLOCATION_STEP * allocation);
                        continue;
                }

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

                ksft_print_msg("%s Check MBA diff within %d%% for schemata %u\n",
                               avg_diff_per > MAX_DIFF_PERCENT ?
                               "Fail:" : "Pass:",
                               MAX_DIFF_PERCENT,
                               ALLOCATION_MIN + ALLOCATION_STEP * allocation);

                ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
                ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
                ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
                if (avg_diff_per > MAX_DIFF_PERCENT)
                        ret = true;
        }

        ksft_print_msg("%s Check schemata change using MBA\n",
                       ret ? "Fail:" : "Pass:");
        if (ret)
                ksft_print_msg("At least one test failed\n");

        return ret;
}

static int check_results(void)
{
        unsigned long bw_resc[NUM_OF_RUNS * ALLOCATION_MAX / ALLOCATION_STEP];
        unsigned long bw_imc[NUM_OF_RUNS * ALLOCATION_MAX / ALLOCATION_STEP];
        char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
        int runs;
        FILE *fp;

        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 fields = 0;

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

                /* Field 3 is perf imc value */
                bw_imc[runs] = strtoul(token_array[3], NULL, 0);
                /* Field 5 is resctrl value */
                bw_resc[runs] = strtoul(token_array[5], NULL, 0);
                runs++;
        }

        fclose(fp);

        return show_mba_info(bw_imc, bw_resc);
}

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

static int mba_run_test(const struct resctrl_test *test, const struct user_params *uparams)
{
        struct resctrl_val_param param = {
                .ctrlgrp        = "c1",
                .filename       = RESULT_FILE_NAME,
                .init           = mba_init,
                .setup          = mba_setup,
                .measure        = mba_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();
        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 mba_feature_check(const struct resctrl_test *test)
{
        return test_resource_feature_check(test) &&
               resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
}

struct resctrl_test mba_test = {
        .name = "MBA",
        .resource = "MB",
        .vendor_specific = ARCH_INTEL,
        .feature_check = mba_feature_check,
        .run_test = mba_run_test,
        .cleanup = mba_test_cleanup,
};