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