xref: /openbmc/linux/tools/lib/perf/evsel.c (revision 91802e73)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <unistd.h>
4 #include <sys/syscall.h>
5 #include <perf/evsel.h>
6 #include <perf/cpumap.h>
7 #include <perf/threadmap.h>
8 #include <linux/list.h>
9 #include <internal/evsel.h>
10 #include <linux/zalloc.h>
11 #include <stdlib.h>
12 #include <internal/xyarray.h>
13 #include <internal/cpumap.h>
14 #include <internal/mmap.h>
15 #include <internal/threadmap.h>
16 #include <internal/lib.h>
17 #include <linux/string.h>
18 #include <sys/ioctl.h>
19 #include <sys/mman.h>
20 #include <asm/bug.h>
21 
22 void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr,
23 		      int idx)
24 {
25 	INIT_LIST_HEAD(&evsel->node);
26 	evsel->attr = *attr;
27 	evsel->idx  = idx;
28 	evsel->leader = evsel;
29 }
30 
31 struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr)
32 {
33 	struct perf_evsel *evsel = zalloc(sizeof(*evsel));
34 
35 	if (evsel != NULL)
36 		perf_evsel__init(evsel, attr, 0);
37 
38 	return evsel;
39 }
40 
41 void perf_evsel__delete(struct perf_evsel *evsel)
42 {
43 	free(evsel);
44 }
45 
46 #define FD(_evsel, _cpu_map_idx, _thread)				\
47 	((int *)xyarray__entry(_evsel->fd, _cpu_map_idx, _thread))
48 #define MMAP(_evsel, _cpu_map_idx, _thread)				\
49 	(_evsel->mmap ? ((struct perf_mmap *) xyarray__entry(_evsel->mmap, _cpu_map_idx, _thread)) \
50 		      : NULL)
51 
52 int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
53 {
54 	evsel->fd = xyarray__new(ncpus, nthreads, sizeof(int));
55 
56 	if (evsel->fd) {
57 		int idx, thread;
58 
59 		for (idx = 0; idx < ncpus; idx++) {
60 			for (thread = 0; thread < nthreads; thread++) {
61 				int *fd = FD(evsel, idx, thread);
62 
63 				if (fd)
64 					*fd = -1;
65 			}
66 		}
67 	}
68 
69 	return evsel->fd != NULL ? 0 : -ENOMEM;
70 }
71 
72 static int perf_evsel__alloc_mmap(struct perf_evsel *evsel, int ncpus, int nthreads)
73 {
74 	evsel->mmap = xyarray__new(ncpus, nthreads, sizeof(struct perf_mmap));
75 
76 	return evsel->mmap != NULL ? 0 : -ENOMEM;
77 }
78 
79 static int
80 sys_perf_event_open(struct perf_event_attr *attr,
81 		    pid_t pid, int cpu, int group_fd,
82 		    unsigned long flags)
83 {
84 	return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags);
85 }
86 
87 static int get_group_fd(struct perf_evsel *evsel, int cpu_map_idx, int thread, int *group_fd)
88 {
89 	struct perf_evsel *leader = evsel->leader;
90 	int *fd;
91 
92 	if (evsel == leader) {
93 		*group_fd = -1;
94 		return 0;
95 	}
96 
97 	/*
98 	 * Leader must be already processed/open,
99 	 * if not it's a bug.
100 	 */
101 	if (!leader->fd)
102 		return -ENOTCONN;
103 
104 	fd = FD(leader, cpu_map_idx, thread);
105 	if (fd == NULL || *fd == -1)
106 		return -EBADF;
107 
108 	*group_fd = *fd;
109 
110 	return 0;
111 }
112 
113 int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
114 		     struct perf_thread_map *threads)
115 {
116 	int cpu, idx, thread, err = 0;
117 
118 	if (cpus == NULL) {
119 		static struct perf_cpu_map *empty_cpu_map;
120 
121 		if (empty_cpu_map == NULL) {
122 			empty_cpu_map = perf_cpu_map__dummy_new();
123 			if (empty_cpu_map == NULL)
124 				return -ENOMEM;
125 		}
126 
127 		cpus = empty_cpu_map;
128 	}
129 
130 	if (threads == NULL) {
131 		static struct perf_thread_map *empty_thread_map;
132 
133 		if (empty_thread_map == NULL) {
134 			empty_thread_map = perf_thread_map__new_dummy();
135 			if (empty_thread_map == NULL)
136 				return -ENOMEM;
137 		}
138 
139 		threads = empty_thread_map;
140 	}
141 
142 	if (evsel->fd == NULL &&
143 	    perf_evsel__alloc_fd(evsel, cpus->nr, threads->nr) < 0)
144 		return -ENOMEM;
145 
146 	perf_cpu_map__for_each_cpu(cpu, idx, cpus) {
147 		for (thread = 0; thread < threads->nr; thread++) {
148 			int fd, group_fd, *evsel_fd;
149 
150 			evsel_fd = FD(evsel, idx, thread);
151 			if (evsel_fd == NULL)
152 				return -EINVAL;
153 
154 			err = get_group_fd(evsel, idx, thread, &group_fd);
155 			if (err < 0)
156 				return err;
157 
158 			fd = sys_perf_event_open(&evsel->attr,
159 						 threads->map[thread].pid,
160 						 cpu, group_fd, 0);
161 
162 			if (fd < 0)
163 				return -errno;
164 
165 			*evsel_fd = fd;
166 		}
167 	}
168 
169 	return err;
170 }
171 
172 static void perf_evsel__close_fd_cpu(struct perf_evsel *evsel, int cpu_map_idx)
173 {
174 	int thread;
175 
176 	for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) {
177 		int *fd = FD(evsel, cpu_map_idx, thread);
178 
179 		if (fd && *fd >= 0) {
180 			close(*fd);
181 			*fd = -1;
182 		}
183 	}
184 }
185 
186 void perf_evsel__close_fd(struct perf_evsel *evsel)
187 {
188 	for (int idx = 0; idx < xyarray__max_x(evsel->fd); idx++)
189 		perf_evsel__close_fd_cpu(evsel, idx);
190 }
191 
192 void perf_evsel__free_fd(struct perf_evsel *evsel)
193 {
194 	xyarray__delete(evsel->fd);
195 	evsel->fd = NULL;
196 }
197 
198 void perf_evsel__close(struct perf_evsel *evsel)
199 {
200 	if (evsel->fd == NULL)
201 		return;
202 
203 	perf_evsel__close_fd(evsel);
204 	perf_evsel__free_fd(evsel);
205 }
206 
207 void perf_evsel__close_cpu(struct perf_evsel *evsel, int cpu_map_idx)
208 {
209 	if (evsel->fd == NULL)
210 		return;
211 
212 	perf_evsel__close_fd_cpu(evsel, cpu_map_idx);
213 }
214 
215 void perf_evsel__munmap(struct perf_evsel *evsel)
216 {
217 	int idx, thread;
218 
219 	if (evsel->fd == NULL || evsel->mmap == NULL)
220 		return;
221 
222 	for (idx = 0; idx < xyarray__max_x(evsel->fd); idx++) {
223 		for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) {
224 			int *fd = FD(evsel, idx, thread);
225 
226 			if (fd == NULL || *fd < 0)
227 				continue;
228 
229 			perf_mmap__munmap(MMAP(evsel, idx, thread));
230 		}
231 	}
232 
233 	xyarray__delete(evsel->mmap);
234 	evsel->mmap = NULL;
235 }
236 
237 int perf_evsel__mmap(struct perf_evsel *evsel, int pages)
238 {
239 	int ret, idx, thread;
240 	struct perf_mmap_param mp = {
241 		.prot = PROT_READ | PROT_WRITE,
242 		.mask = (pages * page_size) - 1,
243 	};
244 
245 	if (evsel->fd == NULL || evsel->mmap)
246 		return -EINVAL;
247 
248 	if (perf_evsel__alloc_mmap(evsel, xyarray__max_x(evsel->fd), xyarray__max_y(evsel->fd)) < 0)
249 		return -ENOMEM;
250 
251 	for (idx = 0; idx < xyarray__max_x(evsel->fd); idx++) {
252 		for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) {
253 			int *fd = FD(evsel, idx, thread);
254 			struct perf_mmap *map;
255 			int cpu = perf_cpu_map__cpu(evsel->cpus, idx);
256 
257 			if (fd == NULL || *fd < 0)
258 				continue;
259 
260 			map = MMAP(evsel, idx, thread);
261 			perf_mmap__init(map, NULL, false, NULL);
262 
263 			ret = perf_mmap__mmap(map, &mp, *fd, cpu);
264 			if (ret) {
265 				perf_evsel__munmap(evsel);
266 				return ret;
267 			}
268 		}
269 	}
270 
271 	return 0;
272 }
273 
274 void *perf_evsel__mmap_base(struct perf_evsel *evsel, int cpu_map_idx, int thread)
275 {
276 	int *fd = FD(evsel, cpu_map_idx, thread);
277 
278 	if (fd == NULL || *fd < 0 || MMAP(evsel, cpu_map_idx, thread) == NULL)
279 		return NULL;
280 
281 	return MMAP(evsel, cpu_map_idx, thread)->base;
282 }
283 
284 int perf_evsel__read_size(struct perf_evsel *evsel)
285 {
286 	u64 read_format = evsel->attr.read_format;
287 	int entry = sizeof(u64); /* value */
288 	int size = 0;
289 	int nr = 1;
290 
291 	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
292 		size += sizeof(u64);
293 
294 	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
295 		size += sizeof(u64);
296 
297 	if (read_format & PERF_FORMAT_ID)
298 		entry += sizeof(u64);
299 
300 	if (read_format & PERF_FORMAT_GROUP) {
301 		nr = evsel->nr_members;
302 		size += sizeof(u64);
303 	}
304 
305 	size += entry * nr;
306 	return size;
307 }
308 
309 int perf_evsel__read(struct perf_evsel *evsel, int cpu_map_idx, int thread,
310 		     struct perf_counts_values *count)
311 {
312 	size_t size = perf_evsel__read_size(evsel);
313 	int *fd = FD(evsel, cpu_map_idx, thread);
314 
315 	memset(count, 0, sizeof(*count));
316 
317 	if (fd == NULL || *fd < 0)
318 		return -EINVAL;
319 
320 	if (MMAP(evsel, cpu_map_idx, thread) &&
321 	    !perf_mmap__read_self(MMAP(evsel, cpu_map_idx, thread), count))
322 		return 0;
323 
324 	if (readn(*fd, count->values, size) <= 0)
325 		return -errno;
326 
327 	return 0;
328 }
329 
330 static int perf_evsel__run_ioctl(struct perf_evsel *evsel,
331 				 int ioc,  void *arg,
332 				 int cpu_map_idx)
333 {
334 	int thread;
335 
336 	for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) {
337 		int err;
338 		int *fd = FD(evsel, cpu_map_idx, thread);
339 
340 		if (fd == NULL || *fd < 0)
341 			return -1;
342 
343 		err = ioctl(*fd, ioc, arg);
344 
345 		if (err)
346 			return err;
347 	}
348 
349 	return 0;
350 }
351 
352 int perf_evsel__enable_cpu(struct perf_evsel *evsel, int cpu_map_idx)
353 {
354 	return perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_ENABLE, NULL, cpu_map_idx);
355 }
356 
357 int perf_evsel__enable(struct perf_evsel *evsel)
358 {
359 	int i;
360 	int err = 0;
361 
362 	for (i = 0; i < xyarray__max_x(evsel->fd) && !err; i++)
363 		err = perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_ENABLE, NULL, i);
364 	return err;
365 }
366 
367 int perf_evsel__disable_cpu(struct perf_evsel *evsel, int cpu_map_idx)
368 {
369 	return perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_DISABLE, NULL, cpu_map_idx);
370 }
371 
372 int perf_evsel__disable(struct perf_evsel *evsel)
373 {
374 	int i;
375 	int err = 0;
376 
377 	for (i = 0; i < xyarray__max_x(evsel->fd) && !err; i++)
378 		err = perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_DISABLE, NULL, i);
379 	return err;
380 }
381 
382 int perf_evsel__apply_filter(struct perf_evsel *evsel, const char *filter)
383 {
384 	int err = 0, i;
385 
386 	for (i = 0; i < evsel->cpus->nr && !err; i++)
387 		err = perf_evsel__run_ioctl(evsel,
388 				     PERF_EVENT_IOC_SET_FILTER,
389 				     (void *)filter, i);
390 	return err;
391 }
392 
393 struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel)
394 {
395 	return evsel->cpus;
396 }
397 
398 struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel)
399 {
400 	return evsel->threads;
401 }
402 
403 struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel)
404 {
405 	return &evsel->attr;
406 }
407 
408 int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
409 {
410 	if (ncpus == 0 || nthreads == 0)
411 		return 0;
412 
413 	if (evsel->system_wide)
414 		nthreads = 1;
415 
416 	evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
417 	if (evsel->sample_id == NULL)
418 		return -ENOMEM;
419 
420 	evsel->id = zalloc(ncpus * nthreads * sizeof(u64));
421 	if (evsel->id == NULL) {
422 		xyarray__delete(evsel->sample_id);
423 		evsel->sample_id = NULL;
424 		return -ENOMEM;
425 	}
426 
427 	return 0;
428 }
429 
430 void perf_evsel__free_id(struct perf_evsel *evsel)
431 {
432 	xyarray__delete(evsel->sample_id);
433 	evsel->sample_id = NULL;
434 	zfree(&evsel->id);
435 	evsel->ids = 0;
436 }
437 
438 void perf_counts_values__scale(struct perf_counts_values *count,
439 			       bool scale, __s8 *pscaled)
440 {
441 	s8 scaled = 0;
442 
443 	if (scale) {
444 		if (count->run == 0) {
445 			scaled = -1;
446 			count->val = 0;
447 		} else if (count->run < count->ena) {
448 			scaled = 1;
449 			count->val = (u64)((double)count->val * count->ena / count->run);
450 		}
451 	}
452 
453 	if (pscaled)
454 		*pscaled = scaled;
455 }
456