xref: /openbmc/linux/tools/perf/util/pmu.c (revision 09ff6071)
1 #include <linux/list.h>
2 #include <linux/compiler.h>
3 #include <sys/types.h>
4 #include <unistd.h>
5 #include <stdio.h>
6 #include <stdbool.h>
7 #include <stdarg.h>
8 #include <dirent.h>
9 #include <api/fs/fs.h>
10 #include <locale.h>
11 #include "util.h"
12 #include "pmu.h"
13 #include "parse-events.h"
14 #include "cpumap.h"
15 
16 struct perf_pmu_format {
17 	char *name;
18 	int value;
19 	DECLARE_BITMAP(bits, PERF_PMU_FORMAT_BITS);
20 	struct list_head list;
21 };
22 
23 #define EVENT_SOURCE_DEVICE_PATH "/bus/event_source/devices/"
24 
25 int perf_pmu_parse(struct list_head *list, char *name);
26 extern FILE *perf_pmu_in;
27 
28 static LIST_HEAD(pmus);
29 
30 /*
31  * Parse & process all the sysfs attributes located under
32  * the directory specified in 'dir' parameter.
33  */
34 int perf_pmu__format_parse(char *dir, struct list_head *head)
35 {
36 	struct dirent *evt_ent;
37 	DIR *format_dir;
38 	int ret = 0;
39 
40 	format_dir = opendir(dir);
41 	if (!format_dir)
42 		return -EINVAL;
43 
44 	while (!ret && (evt_ent = readdir(format_dir))) {
45 		char path[PATH_MAX];
46 		char *name = evt_ent->d_name;
47 		FILE *file;
48 
49 		if (!strcmp(name, ".") || !strcmp(name, ".."))
50 			continue;
51 
52 		snprintf(path, PATH_MAX, "%s/%s", dir, name);
53 
54 		ret = -EINVAL;
55 		file = fopen(path, "r");
56 		if (!file)
57 			break;
58 
59 		perf_pmu_in = file;
60 		ret = perf_pmu_parse(head, name);
61 		fclose(file);
62 	}
63 
64 	closedir(format_dir);
65 	return ret;
66 }
67 
68 /*
69  * Reading/parsing the default pmu format definition, which should be
70  * located at:
71  * /sys/bus/event_source/devices/<dev>/format as sysfs group attributes.
72  */
73 static int pmu_format(const char *name, struct list_head *format)
74 {
75 	struct stat st;
76 	char path[PATH_MAX];
77 	const char *sysfs = sysfs__mountpoint();
78 
79 	if (!sysfs)
80 		return -1;
81 
82 	snprintf(path, PATH_MAX,
83 		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/format", sysfs, name);
84 
85 	if (stat(path, &st) < 0)
86 		return 0;	/* no error if format does not exist */
87 
88 	if (perf_pmu__format_parse(path, format))
89 		return -1;
90 
91 	return 0;
92 }
93 
94 static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, char *dir, char *name)
95 {
96 	struct stat st;
97 	ssize_t sret;
98 	char scale[128];
99 	int fd, ret = -1;
100 	char path[PATH_MAX];
101 	const char *lc;
102 
103 	snprintf(path, PATH_MAX, "%s/%s.scale", dir, name);
104 
105 	fd = open(path, O_RDONLY);
106 	if (fd == -1)
107 		return -1;
108 
109 	if (fstat(fd, &st) < 0)
110 		goto error;
111 
112 	sret = read(fd, scale, sizeof(scale)-1);
113 	if (sret < 0)
114 		goto error;
115 
116 	if (scale[sret - 1] == '\n')
117 		scale[sret - 1] = '\0';
118 	else
119 		scale[sret] = '\0';
120 
121 	/*
122 	 * save current locale
123 	 */
124 	lc = setlocale(LC_NUMERIC, NULL);
125 
126 	/*
127 	 * force to C locale to ensure kernel
128 	 * scale string is converted correctly.
129 	 * kernel uses default C locale.
130 	 */
131 	setlocale(LC_NUMERIC, "C");
132 
133 	alias->scale = strtod(scale, NULL);
134 
135 	/* restore locale */
136 	setlocale(LC_NUMERIC, lc);
137 
138 	ret = 0;
139 error:
140 	close(fd);
141 	return ret;
142 }
143 
144 static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, char *dir, char *name)
145 {
146 	char path[PATH_MAX];
147 	ssize_t sret;
148 	int fd;
149 
150 	snprintf(path, PATH_MAX, "%s/%s.unit", dir, name);
151 
152 	fd = open(path, O_RDONLY);
153 	if (fd == -1)
154 		return -1;
155 
156 		sret = read(fd, alias->unit, UNIT_MAX_LEN);
157 	if (sret < 0)
158 		goto error;
159 
160 	close(fd);
161 
162 	if (alias->unit[sret - 1] == '\n')
163 		alias->unit[sret - 1] = '\0';
164 	else
165 		alias->unit[sret] = '\0';
166 
167 	return 0;
168 error:
169 	close(fd);
170 	alias->unit[0] = '\0';
171 	return -1;
172 }
173 
174 static int
175 perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, char *dir, char *name)
176 {
177 	char path[PATH_MAX];
178 	int fd;
179 
180 	snprintf(path, PATH_MAX, "%s/%s.per-pkg", dir, name);
181 
182 	fd = open(path, O_RDONLY);
183 	if (fd == -1)
184 		return -1;
185 
186 	close(fd);
187 
188 	alias->per_pkg = true;
189 	return 0;
190 }
191 
192 static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
193 				    char *dir, char *name)
194 {
195 	char path[PATH_MAX];
196 	int fd;
197 
198 	snprintf(path, PATH_MAX, "%s/%s.snapshot", dir, name);
199 
200 	fd = open(path, O_RDONLY);
201 	if (fd == -1)
202 		return -1;
203 
204 	alias->snapshot = true;
205 	close(fd);
206 	return 0;
207 }
208 
209 static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
210 				 char *desc __maybe_unused, char *val)
211 {
212 	struct perf_pmu_alias *alias;
213 	int ret;
214 
215 	alias = malloc(sizeof(*alias));
216 	if (!alias)
217 		return -ENOMEM;
218 
219 	INIT_LIST_HEAD(&alias->terms);
220 	alias->scale = 1.0;
221 	alias->unit[0] = '\0';
222 	alias->per_pkg = false;
223 
224 	ret = parse_events_terms(&alias->terms, val);
225 	if (ret) {
226 		pr_err("Cannot parse alias %s: %d\n", val, ret);
227 		free(alias);
228 		return ret;
229 	}
230 
231 	alias->name = strdup(name);
232 	if (dir) {
233 		/*
234 		 * load unit name and scale if available
235 		 */
236 		perf_pmu__parse_unit(alias, dir, name);
237 		perf_pmu__parse_scale(alias, dir, name);
238 		perf_pmu__parse_per_pkg(alias, dir, name);
239 		perf_pmu__parse_snapshot(alias, dir, name);
240 	}
241 
242 	list_add_tail(&alias->list, list);
243 
244 	return 0;
245 }
246 
247 static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FILE *file)
248 {
249 	char buf[256];
250 	int ret;
251 
252 	ret = fread(buf, 1, sizeof(buf), file);
253 	if (ret == 0)
254 		return -EINVAL;
255 
256 	buf[ret] = 0;
257 
258 	return __perf_pmu__new_alias(list, dir, name, NULL, buf);
259 }
260 
261 static inline bool pmu_alias_info_file(char *name)
262 {
263 	size_t len;
264 
265 	len = strlen(name);
266 	if (len > 5 && !strcmp(name + len - 5, ".unit"))
267 		return true;
268 	if (len > 6 && !strcmp(name + len - 6, ".scale"))
269 		return true;
270 	if (len > 8 && !strcmp(name + len - 8, ".per-pkg"))
271 		return true;
272 	if (len > 9 && !strcmp(name + len - 9, ".snapshot"))
273 		return true;
274 
275 	return false;
276 }
277 
278 /*
279  * Process all the sysfs attributes located under the directory
280  * specified in 'dir' parameter.
281  */
282 static int pmu_aliases_parse(char *dir, struct list_head *head)
283 {
284 	struct dirent *evt_ent;
285 	DIR *event_dir;
286 	int ret = 0;
287 
288 	event_dir = opendir(dir);
289 	if (!event_dir)
290 		return -EINVAL;
291 
292 	while (!ret && (evt_ent = readdir(event_dir))) {
293 		char path[PATH_MAX];
294 		char *name = evt_ent->d_name;
295 		FILE *file;
296 
297 		if (!strcmp(name, ".") || !strcmp(name, ".."))
298 			continue;
299 
300 		/*
301 		 * skip info files parsed in perf_pmu__new_alias()
302 		 */
303 		if (pmu_alias_info_file(name))
304 			continue;
305 
306 		snprintf(path, PATH_MAX, "%s/%s", dir, name);
307 
308 		ret = -EINVAL;
309 		file = fopen(path, "r");
310 		if (!file)
311 			break;
312 
313 		ret = perf_pmu__new_alias(head, dir, name, file);
314 		fclose(file);
315 	}
316 
317 	closedir(event_dir);
318 	return ret;
319 }
320 
321 /*
322  * Reading the pmu event aliases definition, which should be located at:
323  * /sys/bus/event_source/devices/<dev>/events as sysfs group attributes.
324  */
325 static int pmu_aliases(const char *name, struct list_head *head)
326 {
327 	struct stat st;
328 	char path[PATH_MAX];
329 	const char *sysfs = sysfs__mountpoint();
330 
331 	if (!sysfs)
332 		return -1;
333 
334 	snprintf(path, PATH_MAX,
335 		 "%s/bus/event_source/devices/%s/events", sysfs, name);
336 
337 	if (stat(path, &st) < 0)
338 		return 0;	 /* no error if 'events' does not exist */
339 
340 	if (pmu_aliases_parse(path, head))
341 		return -1;
342 
343 	return 0;
344 }
345 
346 static int pmu_alias_terms(struct perf_pmu_alias *alias,
347 			   struct list_head *terms)
348 {
349 	struct parse_events_term *term, *cloned;
350 	LIST_HEAD(list);
351 	int ret;
352 
353 	list_for_each_entry(term, &alias->terms, list) {
354 		ret = parse_events_term__clone(&cloned, term);
355 		if (ret) {
356 			parse_events__free_terms(&list);
357 			return ret;
358 		}
359 		list_add_tail(&cloned->list, &list);
360 	}
361 	list_splice(&list, terms);
362 	return 0;
363 }
364 
365 /*
366  * Reading/parsing the default pmu type value, which should be
367  * located at:
368  * /sys/bus/event_source/devices/<dev>/type as sysfs attribute.
369  */
370 static int pmu_type(const char *name, __u32 *type)
371 {
372 	struct stat st;
373 	char path[PATH_MAX];
374 	FILE *file;
375 	int ret = 0;
376 	const char *sysfs = sysfs__mountpoint();
377 
378 	if (!sysfs)
379 		return -1;
380 
381 	snprintf(path, PATH_MAX,
382 		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/type", sysfs, name);
383 
384 	if (stat(path, &st) < 0)
385 		return -1;
386 
387 	file = fopen(path, "r");
388 	if (!file)
389 		return -EINVAL;
390 
391 	if (1 != fscanf(file, "%u", type))
392 		ret = -1;
393 
394 	fclose(file);
395 	return ret;
396 }
397 
398 /* Add all pmus in sysfs to pmu list: */
399 static void pmu_read_sysfs(void)
400 {
401 	char path[PATH_MAX];
402 	DIR *dir;
403 	struct dirent *dent;
404 	const char *sysfs = sysfs__mountpoint();
405 
406 	if (!sysfs)
407 		return;
408 
409 	snprintf(path, PATH_MAX,
410 		 "%s" EVENT_SOURCE_DEVICE_PATH, sysfs);
411 
412 	dir = opendir(path);
413 	if (!dir)
414 		return;
415 
416 	while ((dent = readdir(dir))) {
417 		if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
418 			continue;
419 		/* add to static LIST_HEAD(pmus): */
420 		perf_pmu__find(dent->d_name);
421 	}
422 
423 	closedir(dir);
424 }
425 
426 static struct cpu_map *pmu_cpumask(const char *name)
427 {
428 	struct stat st;
429 	char path[PATH_MAX];
430 	FILE *file;
431 	struct cpu_map *cpus;
432 	const char *sysfs = sysfs__mountpoint();
433 
434 	if (!sysfs)
435 		return NULL;
436 
437 	snprintf(path, PATH_MAX,
438 		 "%s/bus/event_source/devices/%s/cpumask", sysfs, name);
439 
440 	if (stat(path, &st) < 0)
441 		return NULL;
442 
443 	file = fopen(path, "r");
444 	if (!file)
445 		return NULL;
446 
447 	cpus = cpu_map__read(file);
448 	fclose(file);
449 	return cpus;
450 }
451 
452 struct perf_event_attr * __weak
453 perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
454 {
455 	return NULL;
456 }
457 
458 static struct perf_pmu *pmu_lookup(const char *name)
459 {
460 	struct perf_pmu *pmu;
461 	LIST_HEAD(format);
462 	LIST_HEAD(aliases);
463 	__u32 type;
464 
465 	/* No support for intel_bts or intel_pt so disallow them */
466 	if (!strcmp(name, "intel_bts") || !strcmp(name, "intel_pt"))
467 		return NULL;
468 
469 	/*
470 	 * The pmu data we store & need consists of the pmu
471 	 * type value and format definitions. Load both right
472 	 * now.
473 	 */
474 	if (pmu_format(name, &format))
475 		return NULL;
476 
477 	if (pmu_aliases(name, &aliases))
478 		return NULL;
479 
480 	if (pmu_type(name, &type))
481 		return NULL;
482 
483 	pmu = zalloc(sizeof(*pmu));
484 	if (!pmu)
485 		return NULL;
486 
487 	pmu->cpus = pmu_cpumask(name);
488 
489 	INIT_LIST_HEAD(&pmu->format);
490 	INIT_LIST_HEAD(&pmu->aliases);
491 	list_splice(&format, &pmu->format);
492 	list_splice(&aliases, &pmu->aliases);
493 	pmu->name = strdup(name);
494 	pmu->type = type;
495 	list_add_tail(&pmu->list, &pmus);
496 
497 	pmu->default_config = perf_pmu__get_default_config(pmu);
498 
499 	return pmu;
500 }
501 
502 static struct perf_pmu *pmu_find(const char *name)
503 {
504 	struct perf_pmu *pmu;
505 
506 	list_for_each_entry(pmu, &pmus, list)
507 		if (!strcmp(pmu->name, name))
508 			return pmu;
509 
510 	return NULL;
511 }
512 
513 struct perf_pmu *perf_pmu__scan(struct perf_pmu *pmu)
514 {
515 	/*
516 	 * pmu iterator: If pmu is NULL, we start at the begin,
517 	 * otherwise return the next pmu. Returns NULL on end.
518 	 */
519 	if (!pmu) {
520 		pmu_read_sysfs();
521 		pmu = list_prepare_entry(pmu, &pmus, list);
522 	}
523 	list_for_each_entry_continue(pmu, &pmus, list)
524 		return pmu;
525 	return NULL;
526 }
527 
528 struct perf_pmu *perf_pmu__find(const char *name)
529 {
530 	struct perf_pmu *pmu;
531 
532 	/*
533 	 * Once PMU is loaded it stays in the list,
534 	 * so we keep us from multiple reading/parsing
535 	 * the pmu format definitions.
536 	 */
537 	pmu = pmu_find(name);
538 	if (pmu)
539 		return pmu;
540 
541 	return pmu_lookup(name);
542 }
543 
544 static struct perf_pmu_format *
545 pmu_find_format(struct list_head *formats, const char *name)
546 {
547 	struct perf_pmu_format *format;
548 
549 	list_for_each_entry(format, formats, list)
550 		if (!strcmp(format->name, name))
551 			return format;
552 
553 	return NULL;
554 }
555 
556 __u64 perf_pmu__format_bits(struct list_head *formats, const char *name)
557 {
558 	struct perf_pmu_format *format = pmu_find_format(formats, name);
559 	__u64 bits = 0;
560 	int fbit;
561 
562 	if (!format)
563 		return 0;
564 
565 	for_each_set_bit(fbit, format->bits, PERF_PMU_FORMAT_BITS)
566 		bits |= 1ULL << fbit;
567 
568 	return bits;
569 }
570 
571 /*
572  * Sets value based on the format definition (format parameter)
573  * and unformated value (value parameter).
574  */
575 static void pmu_format_value(unsigned long *format, __u64 value, __u64 *v,
576 			     bool zero)
577 {
578 	unsigned long fbit, vbit;
579 
580 	for (fbit = 0, vbit = 0; fbit < PERF_PMU_FORMAT_BITS; fbit++) {
581 
582 		if (!test_bit(fbit, format))
583 			continue;
584 
585 		if (value & (1llu << vbit++))
586 			*v |= (1llu << fbit);
587 		else if (zero)
588 			*v &= ~(1llu << fbit);
589 	}
590 }
591 
592 /*
593  * Term is a string term, and might be a param-term. Try to look up it's value
594  * in the remaining terms.
595  * - We have a term like "base-or-format-term=param-term",
596  * - We need to find the value supplied for "param-term" (with param-term named
597  *   in a config string) later on in the term list.
598  */
599 static int pmu_resolve_param_term(struct parse_events_term *term,
600 				  struct list_head *head_terms,
601 				  __u64 *value)
602 {
603 	struct parse_events_term *t;
604 
605 	list_for_each_entry(t, head_terms, list) {
606 		if (t->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
607 			if (!strcmp(t->config, term->config)) {
608 				t->used = true;
609 				*value = t->val.num;
610 				return 0;
611 			}
612 		}
613 	}
614 
615 	if (verbose)
616 		printf("Required parameter '%s' not specified\n", term->config);
617 
618 	return -1;
619 }
620 
621 static char *formats_error_string(struct list_head *formats)
622 {
623 	struct perf_pmu_format *format;
624 	char *err, *str;
625 	static const char *static_terms = "config,config1,config2,name,period,branch_type,time\n";
626 	unsigned i = 0;
627 
628 	if (!asprintf(&str, "valid terms:"))
629 		return NULL;
630 
631 	/* sysfs exported terms */
632 	list_for_each_entry(format, formats, list) {
633 		char c = i++ ? ',' : ' ';
634 
635 		err = str;
636 		if (!asprintf(&str, "%s%c%s", err, c, format->name))
637 			goto fail;
638 		free(err);
639 	}
640 
641 	/* static terms */
642 	err = str;
643 	if (!asprintf(&str, "%s,%s", err, static_terms))
644 		goto fail;
645 
646 	free(err);
647 	return str;
648 fail:
649 	free(err);
650 	return NULL;
651 }
652 
653 /*
654  * Setup one of config[12] attr members based on the
655  * user input data - term parameter.
656  */
657 static int pmu_config_term(struct list_head *formats,
658 			   struct perf_event_attr *attr,
659 			   struct parse_events_term *term,
660 			   struct list_head *head_terms,
661 			   bool zero, struct parse_events_error *err)
662 {
663 	struct perf_pmu_format *format;
664 	__u64 *vp;
665 	__u64 val;
666 
667 	/*
668 	 * If this is a parameter we've already used for parameterized-eval,
669 	 * skip it in normal eval.
670 	 */
671 	if (term->used)
672 		return 0;
673 
674 	/*
675 	 * Hardcoded terms should be already in, so nothing
676 	 * to be done for them.
677 	 */
678 	if (parse_events__is_hardcoded_term(term))
679 		return 0;
680 
681 	format = pmu_find_format(formats, term->config);
682 	if (!format) {
683 		if (verbose)
684 			printf("Invalid event/parameter '%s'\n", term->config);
685 		if (err) {
686 			err->idx  = term->err_term;
687 			err->str  = strdup("unknown term");
688 			err->help = formats_error_string(formats);
689 		}
690 		return -EINVAL;
691 	}
692 
693 	switch (format->value) {
694 	case PERF_PMU_FORMAT_VALUE_CONFIG:
695 		vp = &attr->config;
696 		break;
697 	case PERF_PMU_FORMAT_VALUE_CONFIG1:
698 		vp = &attr->config1;
699 		break;
700 	case PERF_PMU_FORMAT_VALUE_CONFIG2:
701 		vp = &attr->config2;
702 		break;
703 	default:
704 		return -EINVAL;
705 	}
706 
707 	/*
708 	 * Either directly use a numeric term, or try to translate string terms
709 	 * using event parameters.
710 	 */
711 	if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
712 		val = term->val.num;
713 	else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
714 		if (strcmp(term->val.str, "?")) {
715 			if (verbose) {
716 				pr_info("Invalid sysfs entry %s=%s\n",
717 						term->config, term->val.str);
718 			}
719 			if (err) {
720 				err->idx = term->err_val;
721 				err->str = strdup("expected numeric value");
722 			}
723 			return -EINVAL;
724 		}
725 
726 		if (pmu_resolve_param_term(term, head_terms, &val))
727 			return -EINVAL;
728 	} else
729 		return -EINVAL;
730 
731 	pmu_format_value(format->bits, val, vp, zero);
732 	return 0;
733 }
734 
735 int perf_pmu__config_terms(struct list_head *formats,
736 			   struct perf_event_attr *attr,
737 			   struct list_head *head_terms,
738 			   bool zero, struct parse_events_error *err)
739 {
740 	struct parse_events_term *term;
741 
742 	list_for_each_entry(term, head_terms, list) {
743 		if (pmu_config_term(formats, attr, term, head_terms,
744 				    zero, err))
745 			return -EINVAL;
746 	}
747 
748 	return 0;
749 }
750 
751 /*
752  * Configures event's 'attr' parameter based on the:
753  * 1) users input - specified in terms parameter
754  * 2) pmu format definitions - specified by pmu parameter
755  */
756 int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
757 		     struct list_head *head_terms,
758 		     struct parse_events_error *err)
759 {
760 	bool zero = !!pmu->default_config;
761 
762 	attr->type = pmu->type;
763 	return perf_pmu__config_terms(&pmu->format, attr, head_terms,
764 				      zero, err);
765 }
766 
767 static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
768 					     struct parse_events_term *term)
769 {
770 	struct perf_pmu_alias *alias;
771 	char *name;
772 
773 	if (parse_events__is_hardcoded_term(term))
774 		return NULL;
775 
776 	if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
777 		if (term->val.num != 1)
778 			return NULL;
779 		if (pmu_find_format(&pmu->format, term->config))
780 			return NULL;
781 		name = term->config;
782 	} else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
783 		if (strcasecmp(term->config, "event"))
784 			return NULL;
785 		name = term->val.str;
786 	} else {
787 		return NULL;
788 	}
789 
790 	list_for_each_entry(alias, &pmu->aliases, list) {
791 		if (!strcasecmp(alias->name, name))
792 			return alias;
793 	}
794 	return NULL;
795 }
796 
797 
798 static int check_info_data(struct perf_pmu_alias *alias,
799 			   struct perf_pmu_info *info)
800 {
801 	/*
802 	 * Only one term in event definition can
803 	 * define unit, scale and snapshot, fail
804 	 * if there's more than one.
805 	 */
806 	if ((info->unit && alias->unit) ||
807 	    (info->scale && alias->scale) ||
808 	    (info->snapshot && alias->snapshot))
809 		return -EINVAL;
810 
811 	if (alias->unit)
812 		info->unit = alias->unit;
813 
814 	if (alias->scale)
815 		info->scale = alias->scale;
816 
817 	if (alias->snapshot)
818 		info->snapshot = alias->snapshot;
819 
820 	return 0;
821 }
822 
823 /*
824  * Find alias in the terms list and replace it with the terms
825  * defined for the alias
826  */
827 int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
828 			  struct perf_pmu_info *info)
829 {
830 	struct parse_events_term *term, *h;
831 	struct perf_pmu_alias *alias;
832 	int ret;
833 
834 	info->per_pkg = false;
835 
836 	/*
837 	 * Mark unit and scale as not set
838 	 * (different from default values, see below)
839 	 */
840 	info->unit     = NULL;
841 	info->scale    = 0.0;
842 	info->snapshot = false;
843 
844 	list_for_each_entry_safe(term, h, head_terms, list) {
845 		alias = pmu_find_alias(pmu, term);
846 		if (!alias)
847 			continue;
848 		ret = pmu_alias_terms(alias, &term->list);
849 		if (ret)
850 			return ret;
851 
852 		ret = check_info_data(alias, info);
853 		if (ret)
854 			return ret;
855 
856 		if (alias->per_pkg)
857 			info->per_pkg = true;
858 
859 		list_del(&term->list);
860 		free(term);
861 	}
862 
863 	/*
864 	 * if no unit or scale foundin aliases, then
865 	 * set defaults as for evsel
866 	 * unit cannot left to NULL
867 	 */
868 	if (info->unit == NULL)
869 		info->unit   = "";
870 
871 	if (info->scale == 0.0)
872 		info->scale  = 1.0;
873 
874 	return 0;
875 }
876 
877 int perf_pmu__new_format(struct list_head *list, char *name,
878 			 int config, unsigned long *bits)
879 {
880 	struct perf_pmu_format *format;
881 
882 	format = zalloc(sizeof(*format));
883 	if (!format)
884 		return -ENOMEM;
885 
886 	format->name = strdup(name);
887 	format->value = config;
888 	memcpy(format->bits, bits, sizeof(format->bits));
889 
890 	list_add_tail(&format->list, list);
891 	return 0;
892 }
893 
894 void perf_pmu__set_format(unsigned long *bits, long from, long to)
895 {
896 	long b;
897 
898 	if (!to)
899 		to = from;
900 
901 	memset(bits, 0, BITS_TO_BYTES(PERF_PMU_FORMAT_BITS));
902 	for (b = from; b <= to; b++)
903 		set_bit(b, bits);
904 }
905 
906 static int sub_non_neg(int a, int b)
907 {
908 	if (b > a)
909 		return 0;
910 	return a - b;
911 }
912 
913 static char *format_alias(char *buf, int len, struct perf_pmu *pmu,
914 			  struct perf_pmu_alias *alias)
915 {
916 	struct parse_events_term *term;
917 	int used = snprintf(buf, len, "%s/%s", pmu->name, alias->name);
918 
919 	list_for_each_entry(term, &alias->terms, list) {
920 		if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
921 			used += snprintf(buf + used, sub_non_neg(len, used),
922 					",%s=%s", term->config,
923 					term->val.str);
924 	}
925 
926 	if (sub_non_neg(len, used) > 0) {
927 		buf[used] = '/';
928 		used++;
929 	}
930 	if (sub_non_neg(len, used) > 0) {
931 		buf[used] = '\0';
932 		used++;
933 	} else
934 		buf[len - 1] = '\0';
935 
936 	return buf;
937 }
938 
939 static char *format_alias_or(char *buf, int len, struct perf_pmu *pmu,
940 			     struct perf_pmu_alias *alias)
941 {
942 	snprintf(buf, len, "%s OR %s/%s/", alias->name, pmu->name, alias->name);
943 	return buf;
944 }
945 
946 static int cmp_string(const void *a, const void *b)
947 {
948 	const char * const *as = a;
949 	const char * const *bs = b;
950 	return strcmp(*as, *bs);
951 }
952 
953 void print_pmu_events(const char *event_glob, bool name_only)
954 {
955 	struct perf_pmu *pmu;
956 	struct perf_pmu_alias *alias;
957 	char buf[1024];
958 	int printed = 0;
959 	int len, j;
960 	char **aliases;
961 
962 	pmu = NULL;
963 	len = 0;
964 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
965 		list_for_each_entry(alias, &pmu->aliases, list)
966 			len++;
967 		if (pmu->selectable)
968 			len++;
969 	}
970 	aliases = zalloc(sizeof(char *) * len);
971 	if (!aliases)
972 		goto out_enomem;
973 	pmu = NULL;
974 	j = 0;
975 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
976 		list_for_each_entry(alias, &pmu->aliases, list) {
977 			char *name = format_alias(buf, sizeof(buf), pmu, alias);
978 			bool is_cpu = !strcmp(pmu->name, "cpu");
979 
980 			if (event_glob != NULL &&
981 			    !(strglobmatch(name, event_glob) ||
982 			      (!is_cpu && strglobmatch(alias->name,
983 						       event_glob))))
984 				continue;
985 
986 			if (is_cpu && !name_only)
987 				name = format_alias_or(buf, sizeof(buf), pmu, alias);
988 
989 			aliases[j] = strdup(name);
990 			if (aliases[j] == NULL)
991 				goto out_enomem;
992 			j++;
993 		}
994 		if (pmu->selectable) {
995 			char *s;
996 			if (asprintf(&s, "%s//", pmu->name) < 0)
997 				goto out_enomem;
998 			aliases[j] = s;
999 			j++;
1000 		}
1001 	}
1002 	len = j;
1003 	qsort(aliases, len, sizeof(char *), cmp_string);
1004 	for (j = 0; j < len; j++) {
1005 		if (name_only) {
1006 			printf("%s ", aliases[j]);
1007 			continue;
1008 		}
1009 		printf("  %-50s [Kernel PMU event]\n", aliases[j]);
1010 		printed++;
1011 	}
1012 	if (printed)
1013 		printf("\n");
1014 out_free:
1015 	for (j = 0; j < len; j++)
1016 		zfree(&aliases[j]);
1017 	zfree(&aliases);
1018 	return;
1019 
1020 out_enomem:
1021 	printf("FATAL: not enough memory to print PMU events\n");
1022 	if (aliases)
1023 		goto out_free;
1024 }
1025 
1026 bool pmu_have_event(const char *pname, const char *name)
1027 {
1028 	struct perf_pmu *pmu;
1029 	struct perf_pmu_alias *alias;
1030 
1031 	pmu = NULL;
1032 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
1033 		if (strcmp(pname, pmu->name))
1034 			continue;
1035 		list_for_each_entry(alias, &pmu->aliases, list)
1036 			if (!strcmp(alias->name, name))
1037 				return true;
1038 	}
1039 	return false;
1040 }
1041 
1042 static FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
1043 {
1044 	struct stat st;
1045 	char path[PATH_MAX];
1046 	const char *sysfs;
1047 
1048 	sysfs = sysfs__mountpoint();
1049 	if (!sysfs)
1050 		return NULL;
1051 
1052 	snprintf(path, PATH_MAX,
1053 		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/%s", sysfs, pmu->name, name);
1054 
1055 	if (stat(path, &st) < 0)
1056 		return NULL;
1057 
1058 	return fopen(path, "r");
1059 }
1060 
1061 int perf_pmu__scan_file(struct perf_pmu *pmu, const char *name, const char *fmt,
1062 			...)
1063 {
1064 	va_list args;
1065 	FILE *file;
1066 	int ret = EOF;
1067 
1068 	va_start(args, fmt);
1069 	file = perf_pmu__open_file(pmu, name);
1070 	if (file) {
1071 		ret = vfscanf(file, fmt, args);
1072 		fclose(file);
1073 	}
1074 	va_end(args);
1075 	return ret;
1076 }
1077