1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <stdint.h>
4 #include "resctrl.h"
5 
6 struct read_format {
7 	__u64 nr;			/* The number of events */
8 	struct {
9 		__u64 value;		/* The value of the event */
10 	} values[2];
11 };
12 
13 static struct perf_event_attr pea_llc_miss;
14 static struct read_format rf_cqm;
15 static int fd_lm;
16 char llc_occup_path[1024];
17 
18 static void initialize_perf_event_attr(void)
19 {
20 	pea_llc_miss.type = PERF_TYPE_HARDWARE;
21 	pea_llc_miss.size = sizeof(struct perf_event_attr);
22 	pea_llc_miss.read_format = PERF_FORMAT_GROUP;
23 	pea_llc_miss.exclude_kernel = 1;
24 	pea_llc_miss.exclude_hv = 1;
25 	pea_llc_miss.exclude_idle = 1;
26 	pea_llc_miss.exclude_callchain_kernel = 1;
27 	pea_llc_miss.inherit = 1;
28 	pea_llc_miss.exclude_guest = 1;
29 	pea_llc_miss.disabled = 1;
30 }
31 
32 static void ioctl_perf_event_ioc_reset_enable(void)
33 {
34 	ioctl(fd_lm, PERF_EVENT_IOC_RESET, 0);
35 	ioctl(fd_lm, PERF_EVENT_IOC_ENABLE, 0);
36 }
37 
38 static int perf_event_open_llc_miss(pid_t pid, int cpu_no)
39 {
40 	fd_lm = perf_event_open(&pea_llc_miss, pid, cpu_no, -1,
41 				PERF_FLAG_FD_CLOEXEC);
42 	if (fd_lm == -1) {
43 		perror("Error opening leader");
44 		ctrlc_handler(0, NULL, NULL);
45 		return -1;
46 	}
47 
48 	return 0;
49 }
50 
51 static int initialize_llc_perf(void)
52 {
53 	memset(&pea_llc_miss, 0, sizeof(struct perf_event_attr));
54 	memset(&rf_cqm, 0, sizeof(struct read_format));
55 
56 	/* Initialize perf_event_attr structures for HW_CACHE_MISSES */
57 	initialize_perf_event_attr();
58 
59 	pea_llc_miss.config = PERF_COUNT_HW_CACHE_MISSES;
60 
61 	rf_cqm.nr = 1;
62 
63 	return 0;
64 }
65 
66 static int reset_enable_llc_perf(pid_t pid, int cpu_no)
67 {
68 	int ret = 0;
69 
70 	ret = perf_event_open_llc_miss(pid, cpu_no);
71 	if (ret < 0)
72 		return ret;
73 
74 	/* Start counters to log values */
75 	ioctl_perf_event_ioc_reset_enable();
76 
77 	return 0;
78 }
79 
80 /*
81  * get_llc_perf:	llc cache miss through perf events
82  * @cpu_no:		CPU number that the benchmark PID is binded to
83  *
84  * Perf events like HW_CACHE_MISSES could be used to validate number of
85  * cache lines allocated.
86  *
87  * Return: =0 on success.  <0 on failure.
88  */
89 static int get_llc_perf(unsigned long *llc_perf_miss)
90 {
91 	__u64 total_misses;
92 
93 	/* Stop counters after one span to get miss rate */
94 
95 	ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0);
96 
97 	if (read(fd_lm, &rf_cqm, sizeof(struct read_format)) == -1) {
98 		perror("Could not get llc misses through perf");
99 
100 		return -1;
101 	}
102 
103 	total_misses = rf_cqm.values[0].value;
104 
105 	close(fd_lm);
106 
107 	*llc_perf_miss = total_misses;
108 
109 	return 0;
110 }
111 
112 /*
113  * Get LLC Occupancy as reported by RESCTRL FS
114  * For CMT,
115  * 1. If con_mon grp and mon grp given, then read from mon grp in
116  * con_mon grp
117  * 2. If only con_mon grp given, then read from con_mon grp
118  * 3. If both not given, then read from root con_mon grp
119  * For CAT,
120  * 1. If con_mon grp given, then read from it
121  * 2. If con_mon grp not given, then read from root con_mon grp
122  *
123  * Return: =0 on success.  <0 on failure.
124  */
125 static int get_llc_occu_resctrl(unsigned long *llc_occupancy)
126 {
127 	FILE *fp;
128 
129 	fp = fopen(llc_occup_path, "r");
130 	if (!fp) {
131 		perror("Failed to open results file");
132 
133 		return errno;
134 	}
135 	if (fscanf(fp, "%lu", llc_occupancy) <= 0) {
136 		perror("Could not get llc occupancy");
137 		fclose(fp);
138 
139 		return -1;
140 	}
141 	fclose(fp);
142 
143 	return 0;
144 }
145 
146 /*
147  * print_results_cache:	the cache results are stored in a file
148  * @filename:		file that stores the results
149  * @bm_pid:		child pid that runs benchmark
150  * @llc_value:		perf miss value /
151  *			llc occupancy value reported by resctrl FS
152  *
153  * Return:		0 on success. non-zero on failure.
154  */
155 static int print_results_cache(char *filename, int bm_pid,
156 			       unsigned long llc_value)
157 {
158 	FILE *fp;
159 
160 	if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
161 		printf("Pid: %d \t LLC_value: %lu\n", bm_pid,
162 		       llc_value);
163 	} else {
164 		fp = fopen(filename, "a");
165 		if (!fp) {
166 			perror("Cannot open results file");
167 
168 			return errno;
169 		}
170 		fprintf(fp, "Pid: %d \t llc_value: %lu\n", bm_pid, llc_value);
171 		fclose(fp);
172 	}
173 
174 	return 0;
175 }
176 
177 int measure_cache_vals(struct resctrl_val_param *param, int bm_pid)
178 {
179 	unsigned long llc_perf_miss = 0, llc_occu_resc = 0, llc_value = 0;
180 	int ret;
181 
182 	/*
183 	 * Measure cache miss from perf.
184 	 */
185 	if (!strncmp(param->resctrl_val, CAT_STR, sizeof(CAT_STR))) {
186 		ret = get_llc_perf(&llc_perf_miss);
187 		if (ret < 0)
188 			return ret;
189 		llc_value = llc_perf_miss;
190 	}
191 
192 	/*
193 	 * Measure llc occupancy from resctrl.
194 	 */
195 	if (!strncmp(param->resctrl_val, CMT_STR, sizeof(CMT_STR))) {
196 		ret = get_llc_occu_resctrl(&llc_occu_resc);
197 		if (ret < 0)
198 			return ret;
199 		llc_value = llc_occu_resc;
200 	}
201 	ret = print_results_cache(param->filename, bm_pid, llc_value);
202 	if (ret)
203 		return ret;
204 
205 	return 0;
206 }
207 
208 /*
209  * cache_val:		execute benchmark and measure LLC occupancy resctrl
210  * and perf cache miss for the benchmark
211  * @param:		parameters passed to cache_val()
212  *
213  * Return:		0 on success. non-zero on failure.
214  */
215 int cat_val(struct resctrl_val_param *param)
216 {
217 	int malloc_and_init_memory = 1, memflush = 1, operation = 0, ret = 0;
218 	char *resctrl_val = param->resctrl_val;
219 	pid_t bm_pid;
220 
221 	if (strcmp(param->filename, "") == 0)
222 		sprintf(param->filename, "stdio");
223 
224 	bm_pid = getpid();
225 
226 	/* Taskset benchmark to specified cpu */
227 	ret = taskset_benchmark(bm_pid, param->cpu_no);
228 	if (ret)
229 		return ret;
230 
231 	/* Write benchmark to specified con_mon grp, mon_grp in resctrl FS*/
232 	ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp,
233 				      resctrl_val);
234 	if (ret)
235 		return ret;
236 
237 	if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR))) {
238 		ret = initialize_llc_perf();
239 		if (ret)
240 			return ret;
241 	}
242 
243 	/* Test runs until the callback setup() tells the test to stop. */
244 	while (1) {
245 		if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR))) {
246 			ret = param->setup(1, param);
247 			if (ret) {
248 				ret = 0;
249 				break;
250 			}
251 			ret = reset_enable_llc_perf(bm_pid, param->cpu_no);
252 			if (ret)
253 				break;
254 
255 			if (run_fill_buf(param->span, malloc_and_init_memory,
256 					 memflush, operation, resctrl_val)) {
257 				fprintf(stderr, "Error-running fill buffer\n");
258 				ret = -1;
259 				break;
260 			}
261 
262 			sleep(1);
263 			ret = measure_cache_vals(param, bm_pid);
264 			if (ret)
265 				break;
266 		} else {
267 			break;
268 		}
269 	}
270 
271 	return ret;
272 }
273 
274 /*
275  * show_cache_info:	show cache test result information
276  * @sum_llc_val:	sum of LLC cache result data
277  * @no_of_bits:		number of bits
278  * @cache_span:		cache span in bytes for CMT or in lines for CAT
279  * @max_diff:		max difference
280  * @max_diff_percent:	max difference percentage
281  * @num_of_runs:	number of runs
282  * @platform:		show test information on this platform
283  * @cmt:		CMT test or CAT test
284  *
285  * Return:		0 on success. non-zero on failure.
286  */
287 int show_cache_info(unsigned long sum_llc_val, int no_of_bits,
288 		    unsigned long cache_span, unsigned long max_diff,
289 		    unsigned long max_diff_percent, unsigned long num_of_runs,
290 		    bool platform, bool cmt)
291 {
292 	unsigned long avg_llc_val = 0;
293 	float diff_percent;
294 	long avg_diff = 0;
295 	int ret;
296 
297 	avg_llc_val = sum_llc_val / (num_of_runs - 1);
298 	avg_diff = (long)abs(cache_span - avg_llc_val);
299 	diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100;
300 
301 	ret = platform && abs((int)diff_percent) > max_diff_percent &&
302 	      (cmt ? (abs(avg_diff) > max_diff) : true);
303 
304 	ksft_print_msg("%s Check cache miss rate within %d%%\n",
305 		       ret ? "Fail:" : "Pass:", max_diff_percent);
306 
307 	ksft_print_msg("Percent diff=%d\n", abs((int)diff_percent));
308 	ksft_print_msg("Number of bits: %d\n", no_of_bits);
309 	ksft_print_msg("Average LLC val: %lu\n", avg_llc_val);
310 	ksft_print_msg("Cache span (%s): %lu\n", cmt ? "bytes" : "lines",
311 		       cache_span);
312 
313 	return ret;
314 }
315