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		300
15#define NUM_OF_RUNS		5
16
17static void
18show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, int 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	long avg_diff = 0;
23	int runs;
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 = avg_bw_resc - avg_bw_imc;
37
38	printf("%sok MBM: diff within %d%%\n",
39	       labs(avg_diff) > MAX_DIFF ? "not " : "", MAX_DIFF);
40	tests_run++;
41	printf("# avg_diff: %lu\n", labs(avg_diff));
42	printf("# Span (MB): %d\n", span);
43	printf("# avg_bw_imc: %lu\n", avg_bw_imc);
44	printf("# avg_bw_resc: %lu\n", avg_bw_resc);
45}
46
47static int check_results(int span)
48{
49	unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
50	char temp[1024], *token_array[8];
51	char output[] = RESULT_FILE_NAME;
52	int runs;
53	FILE *fp;
54
55	printf("# Checking for pass/fail\n");
56
57	fp = fopen(output, "r");
58	if (!fp) {
59		perror(output);
60
61		return errno;
62	}
63
64	runs = 0;
65	while (fgets(temp, sizeof(temp), fp)) {
66		char *token = strtok(temp, ":\t");
67		int i = 0;
68
69		while (token) {
70			token_array[i++] = token;
71			token = strtok(NULL, ":\t");
72		}
73
74		bw_resc[runs] = strtoul(token_array[5], NULL, 0);
75		bw_imc[runs] = strtoul(token_array[3], NULL, 0);
76		runs++;
77	}
78
79	show_bw_info(bw_imc, bw_resc, span);
80
81	fclose(fp);
82
83	return 0;
84}
85
86static int mbm_setup(int num, ...)
87{
88	struct resctrl_val_param *p;
89	static int num_of_runs;
90	va_list param;
91	int ret = 0;
92
93	/* Run NUM_OF_RUNS times */
94	if (num_of_runs++ >= NUM_OF_RUNS)
95		return -1;
96
97	va_start(param, num);
98	p = va_arg(param, struct resctrl_val_param *);
99	va_end(param);
100
101	/* Set up shemata with 100% allocation on the first run. */
102	if (num_of_runs == 0)
103		ret = write_schemata(p->ctrlgrp, "100", p->cpu_no,
104				     p->resctrl_val);
105
106	return ret;
107}
108
109void mbm_test_cleanup(void)
110{
111	remove(RESULT_FILE_NAME);
112}
113
114int mbm_bw_change(int span, int cpu_no, char *bw_report, char **benchmark_cmd)
115{
116	struct resctrl_val_param param = {
117		.resctrl_val	= MBM_STR,
118		.ctrlgrp	= "c1",
119		.mongrp		= "m1",
120		.span		= span,
121		.cpu_no		= cpu_no,
122		.mum_resctrlfs	= 1,
123		.filename	= RESULT_FILE_NAME,
124		.bw_report	=  bw_report,
125		.setup		= mbm_setup
126	};
127	int ret;
128
129	remove(RESULT_FILE_NAME);
130
131	if (!validate_resctrl_feature_request("mbm"))
132		return -1;
133
134	ret = resctrl_val(benchmark_cmd, &param);
135	if (ret)
136		return ret;
137
138	ret = check_results(span);
139	if (ret)
140		return ret;
141
142	mbm_test_cleanup();
143
144	return 0;
145}
146