1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Cache Allocation Technology (CAT) 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 #include <unistd.h>
13 
14 #define RESULT_FILE_NAME1	"result_cat1"
15 #define RESULT_FILE_NAME2	"result_cat2"
16 #define NUM_OF_RUNS		5
17 #define MAX_DIFF_PERCENT	4
18 #define MAX_DIFF		1000000
19 
20 static int count_of_bits;
21 static char cbm_mask[256];
22 static unsigned long long_mask;
23 static unsigned long cache_size;
24 
25 /*
26  * Change schemata. Write schemata to specified
27  * con_mon grp, mon_grp in resctrl FS.
28  * Run 5 times in order to get average values.
29  */
30 static int cat_setup(int num, ...)
31 {
32 	struct resctrl_val_param *p;
33 	char schemata[64];
34 	va_list param;
35 	int ret = 0;
36 
37 	va_start(param, num);
38 	p = va_arg(param, struct resctrl_val_param *);
39 	va_end(param);
40 
41 	/* Run NUM_OF_RUNS times */
42 	if (p->num_of_runs >= NUM_OF_RUNS)
43 		return -1;
44 
45 	if (p->num_of_runs == 0) {
46 		sprintf(schemata, "%lx", p->mask);
47 		ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
48 				     p->resctrl_val);
49 	}
50 	p->num_of_runs++;
51 
52 	return ret;
53 }
54 
55 static int check_results(struct resctrl_val_param *param)
56 {
57 	char *token_array[8], temp[512];
58 	unsigned long sum_llc_perf_miss = 0;
59 	int runs = 0, no_of_bits = 0;
60 	FILE *fp;
61 
62 	ksft_print_msg("Checking for pass/fail\n");
63 	fp = fopen(param->filename, "r");
64 	if (!fp) {
65 		perror("# Cannot open file");
66 
67 		return errno;
68 	}
69 
70 	while (fgets(temp, sizeof(temp), fp)) {
71 		char *token = strtok(temp, ":\t");
72 		int fields = 0;
73 
74 		while (token) {
75 			token_array[fields++] = token;
76 			token = strtok(NULL, ":\t");
77 		}
78 		/*
79 		 * Discard the first value which is inaccurate due to monitoring
80 		 * setup transition phase.
81 		 */
82 		if (runs > 0)
83 			sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
84 		runs++;
85 	}
86 
87 	fclose(fp);
88 	no_of_bits = count_bits(param->mask);
89 
90 	return show_cache_info(sum_llc_perf_miss, no_of_bits, param->span / 64,
91 			       MAX_DIFF, MAX_DIFF_PERCENT, NUM_OF_RUNS,
92 			       get_vendor() == ARCH_INTEL, false);
93 }
94 
95 void cat_test_cleanup(void)
96 {
97 	remove(RESULT_FILE_NAME1);
98 	remove(RESULT_FILE_NAME2);
99 }
100 
101 int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
102 {
103 	unsigned long l_mask, l_mask_1;
104 	int ret, pipefd[2], sibling_cpu_no;
105 	char pipe_message;
106 	pid_t bm_pid;
107 
108 	cache_size = 0;
109 
110 	ret = remount_resctrlfs(true);
111 	if (ret)
112 		return ret;
113 
114 	/* Get default cbm mask for L3/L2 cache */
115 	ret = get_cbm_mask(cache_type, cbm_mask);
116 	if (ret)
117 		return ret;
118 
119 	long_mask = strtoul(cbm_mask, NULL, 16);
120 
121 	/* Get L3/L2 cache size */
122 	ret = get_cache_size(cpu_no, cache_type, &cache_size);
123 	if (ret)
124 		return ret;
125 	ksft_print_msg("Cache size :%lu\n", cache_size);
126 
127 	/* Get max number of bits from default-cabm mask */
128 	count_of_bits = count_bits(long_mask);
129 
130 	if (!n)
131 		n = count_of_bits / 2;
132 
133 	if (n > count_of_bits - 1) {
134 		ksft_print_msg("Invalid input value for no_of_bits n!\n");
135 		ksft_print_msg("Please enter value in range 1 to %d\n",
136 			       count_of_bits - 1);
137 		return -1;
138 	}
139 
140 	/* Get core id from same socket for running another thread */
141 	sibling_cpu_no = get_core_sibling(cpu_no);
142 	if (sibling_cpu_no < 0)
143 		return -1;
144 
145 	struct resctrl_val_param param = {
146 		.resctrl_val	= CAT_STR,
147 		.cpu_no		= cpu_no,
148 		.mum_resctrlfs	= 0,
149 		.setup		= cat_setup,
150 	};
151 
152 	l_mask = long_mask >> n;
153 	l_mask_1 = ~l_mask & long_mask;
154 
155 	/* Set param values for parent thread which will be allocated bitmask
156 	 * with (max_bits - n) bits
157 	 */
158 	param.span = cache_size * (count_of_bits - n) / count_of_bits;
159 	strcpy(param.ctrlgrp, "c2");
160 	strcpy(param.mongrp, "m2");
161 	strcpy(param.filename, RESULT_FILE_NAME2);
162 	param.mask = l_mask;
163 	param.num_of_runs = 0;
164 
165 	if (pipe(pipefd)) {
166 		perror("# Unable to create pipe");
167 		return errno;
168 	}
169 
170 	bm_pid = fork();
171 
172 	/* Set param values for child thread which will be allocated bitmask
173 	 * with n bits
174 	 */
175 	if (bm_pid == 0) {
176 		param.mask = l_mask_1;
177 		strcpy(param.ctrlgrp, "c1");
178 		strcpy(param.mongrp, "m1");
179 		param.span = cache_size * n / count_of_bits;
180 		strcpy(param.filename, RESULT_FILE_NAME1);
181 		param.num_of_runs = 0;
182 		param.cpu_no = sibling_cpu_no;
183 	}
184 
185 	remove(param.filename);
186 
187 	ret = cat_val(&param);
188 	if (ret)
189 		return ret;
190 
191 	ret = check_results(&param);
192 	if (ret)
193 		return ret;
194 
195 	if (bm_pid == 0) {
196 		/* Tell parent that child is ready */
197 		close(pipefd[0]);
198 		pipe_message = 1;
199 		if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
200 		    sizeof(pipe_message)) {
201 			close(pipefd[1]);
202 			perror("# failed signaling parent process");
203 			return errno;
204 		}
205 
206 		close(pipefd[1]);
207 		while (1)
208 			;
209 	} else {
210 		/* Parent waits for child to be ready. */
211 		close(pipefd[1]);
212 		pipe_message = 0;
213 		while (pipe_message != 1) {
214 			if (read(pipefd[0], &pipe_message,
215 				 sizeof(pipe_message)) < sizeof(pipe_message)) {
216 				perror("# failed reading from child process");
217 				break;
218 			}
219 		}
220 		close(pipefd[0]);
221 		kill(bm_pid, SIGKILL);
222 	}
223 
224 	cat_test_cleanup();
225 	if (bm_pid)
226 		umount_resctrlfs();
227 
228 	return 0;
229 }
230