1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Memory Bandwidth Monitoring (MBM) test
  4 *
  5 * Copyright (C) 2018 Intel Corporation
  6 *
  7 * Authors:
  8 *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
  9 *    Fenghua Yu <fenghua.yu@intel.com>
 10 */
 11#include "resctrl.h"
 12
 13#define RESULT_FILE_NAME	"result_mbm"
 14#define MAX_DIFF_PERCENT	8
 15#define NUM_OF_RUNS		5
 16
 17static int
 18show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, size_t span)
 19{
 20	unsigned long avg_bw_imc = 0, avg_bw_resc = 0;
 21	unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
 22	int runs, ret, avg_diff_per;
 23	float avg_diff = 0;
 24
 25	/*
 26	 * Discard the first value which is inaccurate due to monitoring setup
 27	 * transition phase.
 28	 */
 29	for (runs = 1; runs < NUM_OF_RUNS ; runs++) {
 30		sum_bw_imc += bw_imc[runs];
 31		sum_bw_resc += bw_resc[runs];
 32	}
 33
 34	avg_bw_imc = sum_bw_imc / 4;
 35	avg_bw_resc = sum_bw_resc / 4;
 36	avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
 37	avg_diff_per = (int)(avg_diff * 100);
 38
 39	ret = avg_diff_per > MAX_DIFF_PERCENT;
 40	ksft_print_msg("%s Check MBM diff within %d%%\n",
 41		       ret ? "Fail:" : "Pass:", MAX_DIFF_PERCENT);
 42	ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
 43	ksft_print_msg("Span (MB): %zu\n", span / MB);
 44	ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
 45	ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
 46
 47	return ret;
 48}
 49
 50static int check_results(size_t span)
 51{
 52	unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
 53	char temp[1024], *token_array[8];
 54	char output[] = RESULT_FILE_NAME;
 55	int runs, ret;
 56	FILE *fp;
 57
 58	ksft_print_msg("Checking for pass/fail\n");
 59
 60	fp = fopen(output, "r");
 61	if (!fp) {
 62		ksft_perror(output);
 63
 64		return -1;
 65	}
 66
 67	runs = 0;
 68	while (fgets(temp, sizeof(temp), fp)) {
 69		char *token = strtok(temp, ":\t");
 70		int i = 0;
 71
 72		while (token) {
 73			token_array[i++] = token;
 74			token = strtok(NULL, ":\t");
 75		}
 76
 77		bw_resc[runs] = strtoul(token_array[5], NULL, 0);
 78		bw_imc[runs] = strtoul(token_array[3], NULL, 0);
 79		runs++;
 80	}
 81
 82	ret = show_bw_info(bw_imc, bw_resc, span);
 83
 84	fclose(fp);
 85
 86	return ret;
 87}
 88
 89static int mbm_setup(const struct resctrl_test *test,
 90		     const struct user_params *uparams,
 91		     struct resctrl_val_param *p)
 92{
 93	int ret = 0;
 94
 95	/* Run NUM_OF_RUNS times */
 96	if (p->num_of_runs >= NUM_OF_RUNS)
 97		return END_OF_TESTS;
 98
 99	/* Set up shemata with 100% allocation on the first run. */
100	if (p->num_of_runs == 0 && resctrl_resource_exists("MB"))
101		ret = write_schemata(p->ctrlgrp, "100", uparams->cpu, test->resource);
102
103	p->num_of_runs++;
104
105	return ret;
106}
107
108void mbm_test_cleanup(void)
109{
110	remove(RESULT_FILE_NAME);
111}
112
113static int mbm_run_test(const struct resctrl_test *test, const struct user_params *uparams)
114{
115	struct resctrl_val_param param = {
116		.resctrl_val	= MBM_STR,
117		.ctrlgrp	= "c1",
118		.mongrp		= "m1",
119		.filename	= RESULT_FILE_NAME,
120		.bw_report	= "reads",
121		.setup		= mbm_setup
122	};
123	int ret;
124
125	remove(RESULT_FILE_NAME);
126
127	ret = resctrl_val(test, uparams, uparams->benchmark_cmd, &param);
128	if (ret)
129		goto out;
130
131	ret = check_results(DEFAULT_SPAN);
132	if (ret && (get_vendor() == ARCH_INTEL))
133		ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
134
135out:
136	mbm_test_cleanup();
137
138	return ret;
139}
140
141static bool mbm_feature_check(const struct resctrl_test *test)
142{
143	return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") &&
144	       resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
145}
146
147struct resctrl_test mbm_test = {
148	.name = "MBM",
149	.resource = "MB",
150	.vendor_specific = ARCH_INTEL,
151	.feature_check = mbm_feature_check,
152	.run_test = mbm_run_test,
153};