xref: /openbmc/linux/tools/lib/perf/evsel.c (revision 1edd0337)
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, struct perf_cpu cpu, int group_fd,
82 		    unsigned long flags)
83 {
84 	return syscall(__NR_perf_event_open, attr, pid, cpu.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 	struct perf_cpu cpu;
117 	int idx, thread, err = 0;
118 
119 	if (cpus == NULL) {
120 		static struct perf_cpu_map *empty_cpu_map;
121 
122 		if (empty_cpu_map == NULL) {
123 			empty_cpu_map = perf_cpu_map__dummy_new();
124 			if (empty_cpu_map == NULL)
125 				return -ENOMEM;
126 		}
127 
128 		cpus = empty_cpu_map;
129 	}
130 
131 	if (threads == NULL) {
132 		static struct perf_thread_map *empty_thread_map;
133 
134 		if (empty_thread_map == NULL) {
135 			empty_thread_map = perf_thread_map__new_dummy();
136 			if (empty_thread_map == NULL)
137 				return -ENOMEM;
138 		}
139 
140 		threads = empty_thread_map;
141 	}
142 
143 	if (evsel->fd == NULL &&
144 	    perf_evsel__alloc_fd(evsel, perf_cpu_map__nr(cpus), threads->nr) < 0)
145 		return -ENOMEM;
146 
147 	perf_cpu_map__for_each_cpu(cpu, idx, cpus) {
148 		for (thread = 0; thread < threads->nr; thread++) {
149 			int fd, group_fd, *evsel_fd;
150 
151 			evsel_fd = FD(evsel, idx, thread);
152 			if (evsel_fd == NULL) {
153 				err = -EINVAL;
154 				goto out;
155 			}
156 
157 			err = get_group_fd(evsel, idx, thread, &group_fd);
158 			if (err < 0)
159 				goto out;
160 
161 			fd = sys_perf_event_open(&evsel->attr,
162 						 threads->map[thread].pid,
163 						 cpu, group_fd, 0);
164 
165 			if (fd < 0) {
166 				err = -errno;
167 				goto out;
168 			}
169 
170 			*evsel_fd = fd;
171 		}
172 	}
173 out:
174 	if (err)
175 		perf_evsel__close(evsel);
176 
177 	return err;
178 }
179 
180 static void perf_evsel__close_fd_cpu(struct perf_evsel *evsel, int cpu_map_idx)
181 {
182 	int thread;
183 
184 	for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) {
185 		int *fd = FD(evsel, cpu_map_idx, thread);
186 
187 		if (fd && *fd >= 0) {
188 			close(*fd);
189 			*fd = -1;
190 		}
191 	}
192 }
193 
194 void perf_evsel__close_fd(struct perf_evsel *evsel)
195 {
196 	for (int idx = 0; idx < xyarray__max_x(evsel->fd); idx++)
197 		perf_evsel__close_fd_cpu(evsel, idx);
198 }
199 
200 void perf_evsel__free_fd(struct perf_evsel *evsel)
201 {
202 	xyarray__delete(evsel->fd);
203 	evsel->fd = NULL;
204 }
205 
206 void perf_evsel__close(struct perf_evsel *evsel)
207 {
208 	if (evsel->fd == NULL)
209 		return;
210 
211 	perf_evsel__close_fd(evsel);
212 	perf_evsel__free_fd(evsel);
213 }
214 
215 void perf_evsel__close_cpu(struct perf_evsel *evsel, int cpu_map_idx)
216 {
217 	if (evsel->fd == NULL)
218 		return;
219 
220 	perf_evsel__close_fd_cpu(evsel, cpu_map_idx);
221 }
222 
223 void perf_evsel__munmap(struct perf_evsel *evsel)
224 {
225 	int idx, thread;
226 
227 	if (evsel->fd == NULL || evsel->mmap == NULL)
228 		return;
229 
230 	for (idx = 0; idx < xyarray__max_x(evsel->fd); idx++) {
231 		for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) {
232 			int *fd = FD(evsel, idx, thread);
233 
234 			if (fd == NULL || *fd < 0)
235 				continue;
236 
237 			perf_mmap__munmap(MMAP(evsel, idx, thread));
238 		}
239 	}
240 
241 	xyarray__delete(evsel->mmap);
242 	evsel->mmap = NULL;
243 }
244 
245 int perf_evsel__mmap(struct perf_evsel *evsel, int pages)
246 {
247 	int ret, idx, thread;
248 	struct perf_mmap_param mp = {
249 		.prot = PROT_READ | PROT_WRITE,
250 		.mask = (pages * page_size) - 1,
251 	};
252 
253 	if (evsel->fd == NULL || evsel->mmap)
254 		return -EINVAL;
255 
256 	if (perf_evsel__alloc_mmap(evsel, xyarray__max_x(evsel->fd), xyarray__max_y(evsel->fd)) < 0)
257 		return -ENOMEM;
258 
259 	for (idx = 0; idx < xyarray__max_x(evsel->fd); idx++) {
260 		for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) {
261 			int *fd = FD(evsel, idx, thread);
262 			struct perf_mmap *map;
263 			struct perf_cpu cpu = perf_cpu_map__cpu(evsel->cpus, idx);
264 
265 			if (fd == NULL || *fd < 0)
266 				continue;
267 
268 			map = MMAP(evsel, idx, thread);
269 			perf_mmap__init(map, NULL, false, NULL);
270 
271 			ret = perf_mmap__mmap(map, &mp, *fd, cpu);
272 			if (ret) {
273 				perf_evsel__munmap(evsel);
274 				return ret;
275 			}
276 		}
277 	}
278 
279 	return 0;
280 }
281 
282 void *perf_evsel__mmap_base(struct perf_evsel *evsel, int cpu_map_idx, int thread)
283 {
284 	int *fd = FD(evsel, cpu_map_idx, thread);
285 
286 	if (fd == NULL || *fd < 0 || MMAP(evsel, cpu_map_idx, thread) == NULL)
287 		return NULL;
288 
289 	return MMAP(evsel, cpu_map_idx, thread)->base;
290 }
291 
292 int perf_evsel__read_size(struct perf_evsel *evsel)
293 {
294 	u64 read_format = evsel->attr.read_format;
295 	int entry = sizeof(u64); /* value */
296 	int size = 0;
297 	int nr = 1;
298 
299 	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
300 		size += sizeof(u64);
301 
302 	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
303 		size += sizeof(u64);
304 
305 	if (read_format & PERF_FORMAT_ID)
306 		entry += sizeof(u64);
307 
308 	if (read_format & PERF_FORMAT_LOST)
309 		entry += sizeof(u64);
310 
311 	if (read_format & PERF_FORMAT_GROUP) {
312 		nr = evsel->nr_members;
313 		size += sizeof(u64);
314 	}
315 
316 	size += entry * nr;
317 	return size;
318 }
319 
320 /* This only reads values for the leader */
321 static int perf_evsel__read_group(struct perf_evsel *evsel, int cpu_map_idx,
322 				  int thread, struct perf_counts_values *count)
323 {
324 	size_t size = perf_evsel__read_size(evsel);
325 	int *fd = FD(evsel, cpu_map_idx, thread);
326 	u64 read_format = evsel->attr.read_format;
327 	u64 *data;
328 	int idx = 1;
329 
330 	if (fd == NULL || *fd < 0)
331 		return -EINVAL;
332 
333 	data = calloc(1, size);
334 	if (data == NULL)
335 		return -ENOMEM;
336 
337 	if (readn(*fd, data, size) <= 0) {
338 		free(data);
339 		return -errno;
340 	}
341 
342 	/*
343 	 * This reads only the leader event intentionally since we don't have
344 	 * perf counts values for sibling events.
345 	 */
346 	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
347 		count->ena = data[idx++];
348 	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
349 		count->run = data[idx++];
350 
351 	/* value is always available */
352 	count->val = data[idx++];
353 	if (read_format & PERF_FORMAT_ID)
354 		count->id = data[idx++];
355 	if (read_format & PERF_FORMAT_LOST)
356 		count->lost = data[idx++];
357 
358 	free(data);
359 	return 0;
360 }
361 
362 /*
363  * The perf read format is very flexible.  It needs to set the proper
364  * values according to the read format.
365  */
366 static void perf_evsel__adjust_values(struct perf_evsel *evsel, u64 *buf,
367 				      struct perf_counts_values *count)
368 {
369 	u64 read_format = evsel->attr.read_format;
370 	int n = 0;
371 
372 	count->val = buf[n++];
373 
374 	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
375 		count->ena = buf[n++];
376 
377 	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
378 		count->run = buf[n++];
379 
380 	if (read_format & PERF_FORMAT_ID)
381 		count->id = buf[n++];
382 
383 	if (read_format & PERF_FORMAT_LOST)
384 		count->lost = buf[n++];
385 }
386 
387 int perf_evsel__read(struct perf_evsel *evsel, int cpu_map_idx, int thread,
388 		     struct perf_counts_values *count)
389 {
390 	size_t size = perf_evsel__read_size(evsel);
391 	int *fd = FD(evsel, cpu_map_idx, thread);
392 	u64 read_format = evsel->attr.read_format;
393 	struct perf_counts_values buf;
394 
395 	memset(count, 0, sizeof(*count));
396 
397 	if (fd == NULL || *fd < 0)
398 		return -EINVAL;
399 
400 	if (read_format & PERF_FORMAT_GROUP)
401 		return perf_evsel__read_group(evsel, cpu_map_idx, thread, count);
402 
403 	if (MMAP(evsel, cpu_map_idx, thread) &&
404 	    !(read_format & (PERF_FORMAT_ID | PERF_FORMAT_LOST)) &&
405 	    !perf_mmap__read_self(MMAP(evsel, cpu_map_idx, thread), count))
406 		return 0;
407 
408 	if (readn(*fd, buf.values, size) <= 0)
409 		return -errno;
410 
411 	perf_evsel__adjust_values(evsel, buf.values, count);
412 	return 0;
413 }
414 
415 static int perf_evsel__ioctl(struct perf_evsel *evsel, int ioc, void *arg,
416 			     int cpu_map_idx, int thread)
417 {
418 	int *fd = FD(evsel, cpu_map_idx, thread);
419 
420 	if (fd == NULL || *fd < 0)
421 		return -1;
422 
423 	return ioctl(*fd, ioc, arg);
424 }
425 
426 static int perf_evsel__run_ioctl(struct perf_evsel *evsel,
427 				 int ioc,  void *arg,
428 				 int cpu_map_idx)
429 {
430 	int thread;
431 
432 	for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) {
433 		int err = perf_evsel__ioctl(evsel, ioc, arg, cpu_map_idx, thread);
434 
435 		if (err)
436 			return err;
437 	}
438 
439 	return 0;
440 }
441 
442 int perf_evsel__enable_cpu(struct perf_evsel *evsel, int cpu_map_idx)
443 {
444 	return perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_ENABLE, NULL, cpu_map_idx);
445 }
446 
447 int perf_evsel__enable_thread(struct perf_evsel *evsel, int thread)
448 {
449 	struct perf_cpu cpu __maybe_unused;
450 	int idx;
451 	int err;
452 
453 	perf_cpu_map__for_each_cpu(cpu, idx, evsel->cpus) {
454 		err = perf_evsel__ioctl(evsel, PERF_EVENT_IOC_ENABLE, NULL, idx, thread);
455 		if (err)
456 			return err;
457 	}
458 
459 	return 0;
460 }
461 
462 int perf_evsel__enable(struct perf_evsel *evsel)
463 {
464 	int i;
465 	int err = 0;
466 
467 	for (i = 0; i < xyarray__max_x(evsel->fd) && !err; i++)
468 		err = perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_ENABLE, NULL, i);
469 	return err;
470 }
471 
472 int perf_evsel__disable_cpu(struct perf_evsel *evsel, int cpu_map_idx)
473 {
474 	return perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_DISABLE, NULL, cpu_map_idx);
475 }
476 
477 int perf_evsel__disable(struct perf_evsel *evsel)
478 {
479 	int i;
480 	int err = 0;
481 
482 	for (i = 0; i < xyarray__max_x(evsel->fd) && !err; i++)
483 		err = perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_DISABLE, NULL, i);
484 	return err;
485 }
486 
487 int perf_evsel__apply_filter(struct perf_evsel *evsel, const char *filter)
488 {
489 	int err = 0, i;
490 
491 	for (i = 0; i < perf_cpu_map__nr(evsel->cpus) && !err; i++)
492 		err = perf_evsel__run_ioctl(evsel,
493 				     PERF_EVENT_IOC_SET_FILTER,
494 				     (void *)filter, i);
495 	return err;
496 }
497 
498 struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel)
499 {
500 	return evsel->cpus;
501 }
502 
503 struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel)
504 {
505 	return evsel->threads;
506 }
507 
508 struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel)
509 {
510 	return &evsel->attr;
511 }
512 
513 int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
514 {
515 	if (ncpus == 0 || nthreads == 0)
516 		return 0;
517 
518 	evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
519 	if (evsel->sample_id == NULL)
520 		return -ENOMEM;
521 
522 	evsel->id = zalloc(ncpus * nthreads * sizeof(u64));
523 	if (evsel->id == NULL) {
524 		xyarray__delete(evsel->sample_id);
525 		evsel->sample_id = NULL;
526 		return -ENOMEM;
527 	}
528 
529 	return 0;
530 }
531 
532 void perf_evsel__free_id(struct perf_evsel *evsel)
533 {
534 	xyarray__delete(evsel->sample_id);
535 	evsel->sample_id = NULL;
536 	zfree(&evsel->id);
537 	evsel->ids = 0;
538 }
539 
540 void perf_counts_values__scale(struct perf_counts_values *count,
541 			       bool scale, __s8 *pscaled)
542 {
543 	s8 scaled = 0;
544 
545 	if (scale) {
546 		if (count->run == 0) {
547 			scaled = -1;
548 			count->val = 0;
549 		} else if (count->run < count->ena) {
550 			scaled = 1;
551 			count->val = (u64)((double)count->val * count->ena / count->run);
552 		}
553 	}
554 
555 	if (pscaled)
556 		*pscaled = scaled;
557 }
558