xref: /linux/tools/perf/util/pmu.c (revision 5643b1a59e581ac3f66d36caba8124313cc446c0)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/list.h>
3 #include <linux/compiler.h>
4 #include <linux/string.h>
5 #include <linux/zalloc.h>
6 #include <sys/types.h>
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <sys/stat.h>
10 #include <unistd.h>
11 #include <stdio.h>
12 #include <stdbool.h>
13 #include <stdarg.h>
14 #include <dirent.h>
15 #include <api/fs/fs.h>
16 #include <locale.h>
17 #include <regex.h>
18 #include <perf/cpumap.h>
19 #include "pmu.h"
20 #include "parse-events.h"
21 #include "cpumap.h"
22 #include "header.h"
23 #include "pmu-events/pmu-events.h"
24 #include "cache.h"
25 #include "string2.h"
26 
27 struct perf_pmu_format {
28 	char *name;
29 	int value;
30 	DECLARE_BITMAP(bits, PERF_PMU_FORMAT_BITS);
31 	struct list_head list;
32 };
33 
34 int perf_pmu_parse(struct list_head *list, char *name);
35 extern FILE *perf_pmu_in;
36 
37 static LIST_HEAD(pmus);
38 
39 /*
40  * Parse & process all the sysfs attributes located under
41  * the directory specified in 'dir' parameter.
42  */
43 int perf_pmu__format_parse(char *dir, struct list_head *head)
44 {
45 	struct dirent *evt_ent;
46 	DIR *format_dir;
47 	int ret = 0;
48 
49 	format_dir = opendir(dir);
50 	if (!format_dir)
51 		return -EINVAL;
52 
53 	while (!ret && (evt_ent = readdir(format_dir))) {
54 		char path[PATH_MAX];
55 		char *name = evt_ent->d_name;
56 		FILE *file;
57 
58 		if (!strcmp(name, ".") || !strcmp(name, ".."))
59 			continue;
60 
61 		snprintf(path, PATH_MAX, "%s/%s", dir, name);
62 
63 		ret = -EINVAL;
64 		file = fopen(path, "r");
65 		if (!file)
66 			break;
67 
68 		perf_pmu_in = file;
69 		ret = perf_pmu_parse(head, name);
70 		fclose(file);
71 	}
72 
73 	closedir(format_dir);
74 	return ret;
75 }
76 
77 /*
78  * Reading/parsing the default pmu format definition, which should be
79  * located at:
80  * /sys/bus/event_source/devices/<dev>/format as sysfs group attributes.
81  */
82 static int pmu_format(const char *name, struct list_head *format)
83 {
84 	struct stat st;
85 	char path[PATH_MAX];
86 	const char *sysfs = sysfs__mountpoint();
87 
88 	if (!sysfs)
89 		return -1;
90 
91 	snprintf(path, PATH_MAX,
92 		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/format", sysfs, name);
93 
94 	if (stat(path, &st) < 0)
95 		return 0;	/* no error if format does not exist */
96 
97 	if (perf_pmu__format_parse(path, format))
98 		return -1;
99 
100 	return 0;
101 }
102 
103 static int convert_scale(const char *scale, char **end, double *sval)
104 {
105 	char *lc;
106 	int ret = 0;
107 
108 	/*
109 	 * save current locale
110 	 */
111 	lc = setlocale(LC_NUMERIC, NULL);
112 
113 	/*
114 	 * The lc string may be allocated in static storage,
115 	 * so get a dynamic copy to make it survive setlocale
116 	 * call below.
117 	 */
118 	lc = strdup(lc);
119 	if (!lc) {
120 		ret = -ENOMEM;
121 		goto out;
122 	}
123 
124 	/*
125 	 * force to C locale to ensure kernel
126 	 * scale string is converted correctly.
127 	 * kernel uses default C locale.
128 	 */
129 	setlocale(LC_NUMERIC, "C");
130 
131 	*sval = strtod(scale, end);
132 
133 out:
134 	/* restore locale */
135 	setlocale(LC_NUMERIC, lc);
136 	free(lc);
137 	return ret;
138 }
139 
140 static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, char *dir, char *name)
141 {
142 	struct stat st;
143 	ssize_t sret;
144 	char scale[128];
145 	int fd, ret = -1;
146 	char path[PATH_MAX];
147 
148 	scnprintf(path, PATH_MAX, "%s/%s.scale", dir, name);
149 
150 	fd = open(path, O_RDONLY);
151 	if (fd == -1)
152 		return -1;
153 
154 	if (fstat(fd, &st) < 0)
155 		goto error;
156 
157 	sret = read(fd, scale, sizeof(scale)-1);
158 	if (sret < 0)
159 		goto error;
160 
161 	if (scale[sret - 1] == '\n')
162 		scale[sret - 1] = '\0';
163 	else
164 		scale[sret] = '\0';
165 
166 	ret = convert_scale(scale, NULL, &alias->scale);
167 error:
168 	close(fd);
169 	return ret;
170 }
171 
172 static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, char *dir, char *name)
173 {
174 	char path[PATH_MAX];
175 	ssize_t sret;
176 	int fd;
177 
178 	scnprintf(path, PATH_MAX, "%s/%s.unit", dir, name);
179 
180 	fd = open(path, O_RDONLY);
181 	if (fd == -1)
182 		return -1;
183 
184 	sret = read(fd, alias->unit, UNIT_MAX_LEN);
185 	if (sret < 0)
186 		goto error;
187 
188 	close(fd);
189 
190 	if (alias->unit[sret - 1] == '\n')
191 		alias->unit[sret - 1] = '\0';
192 	else
193 		alias->unit[sret] = '\0';
194 
195 	return 0;
196 error:
197 	close(fd);
198 	alias->unit[0] = '\0';
199 	return -1;
200 }
201 
202 static int
203 perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, char *dir, char *name)
204 {
205 	char path[PATH_MAX];
206 	int fd;
207 
208 	scnprintf(path, PATH_MAX, "%s/%s.per-pkg", dir, name);
209 
210 	fd = open(path, O_RDONLY);
211 	if (fd == -1)
212 		return -1;
213 
214 	close(fd);
215 
216 	alias->per_pkg = true;
217 	return 0;
218 }
219 
220 static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
221 				    char *dir, char *name)
222 {
223 	char path[PATH_MAX];
224 	int fd;
225 
226 	scnprintf(path, PATH_MAX, "%s/%s.snapshot", dir, name);
227 
228 	fd = open(path, O_RDONLY);
229 	if (fd == -1)
230 		return -1;
231 
232 	alias->snapshot = true;
233 	close(fd);
234 	return 0;
235 }
236 
237 static void perf_pmu_assign_str(char *name, const char *field, char **old_str,
238 				char **new_str)
239 {
240 	if (!*old_str)
241 		goto set_new;
242 
243 	if (*new_str) {	/* Have new string, check with old */
244 		if (strcasecmp(*old_str, *new_str))
245 			pr_debug("alias %s differs in field '%s'\n",
246 				 name, field);
247 		zfree(old_str);
248 	} else		/* Nothing new --> keep old string */
249 		return;
250 set_new:
251 	*old_str = *new_str;
252 	*new_str = NULL;
253 }
254 
255 static void perf_pmu_update_alias(struct perf_pmu_alias *old,
256 				  struct perf_pmu_alias *newalias)
257 {
258 	perf_pmu_assign_str(old->name, "desc", &old->desc, &newalias->desc);
259 	perf_pmu_assign_str(old->name, "long_desc", &old->long_desc,
260 			    &newalias->long_desc);
261 	perf_pmu_assign_str(old->name, "topic", &old->topic, &newalias->topic);
262 	perf_pmu_assign_str(old->name, "metric_expr", &old->metric_expr,
263 			    &newalias->metric_expr);
264 	perf_pmu_assign_str(old->name, "metric_name", &old->metric_name,
265 			    &newalias->metric_name);
266 	perf_pmu_assign_str(old->name, "value", &old->str, &newalias->str);
267 	old->scale = newalias->scale;
268 	old->per_pkg = newalias->per_pkg;
269 	old->snapshot = newalias->snapshot;
270 	memcpy(old->unit, newalias->unit, sizeof(old->unit));
271 }
272 
273 /* Delete an alias entry. */
274 static void perf_pmu_free_alias(struct perf_pmu_alias *newalias)
275 {
276 	zfree(&newalias->name);
277 	zfree(&newalias->desc);
278 	zfree(&newalias->long_desc);
279 	zfree(&newalias->topic);
280 	zfree(&newalias->str);
281 	zfree(&newalias->metric_expr);
282 	zfree(&newalias->metric_name);
283 	parse_events_terms__purge(&newalias->terms);
284 	free(newalias);
285 }
286 
287 /* Merge an alias, search in alias list. If this name is already
288  * present merge both of them to combine all information.
289  */
290 static bool perf_pmu_merge_alias(struct perf_pmu_alias *newalias,
291 				 struct list_head *alist)
292 {
293 	struct perf_pmu_alias *a;
294 
295 	list_for_each_entry(a, alist, list) {
296 		if (!strcasecmp(newalias->name, a->name)) {
297 			perf_pmu_update_alias(a, newalias);
298 			perf_pmu_free_alias(newalias);
299 			return true;
300 		}
301 	}
302 	return false;
303 }
304 
305 static int __perf_pmu__new_alias(struct list_head *list, char *dir, char *name,
306 				 char *desc, char *val,
307 				 char *long_desc, char *topic,
308 				 char *unit, char *perpkg,
309 				 char *metric_expr,
310 				 char *metric_name)
311 {
312 	struct parse_events_term *term;
313 	struct perf_pmu_alias *alias;
314 	int ret;
315 	int num;
316 	char newval[256];
317 
318 	alias = malloc(sizeof(*alias));
319 	if (!alias)
320 		return -ENOMEM;
321 
322 	INIT_LIST_HEAD(&alias->terms);
323 	alias->scale = 1.0;
324 	alias->unit[0] = '\0';
325 	alias->per_pkg = false;
326 	alias->snapshot = false;
327 
328 	ret = parse_events_terms(&alias->terms, val);
329 	if (ret) {
330 		pr_err("Cannot parse alias %s: %d\n", val, ret);
331 		free(alias);
332 		return ret;
333 	}
334 
335 	/* Scan event and remove leading zeroes, spaces, newlines, some
336 	 * platforms have terms specified as
337 	 * event=0x0091 (read from files ../<PMU>/events/<FILE>
338 	 * and terms specified as event=0x91 (read from JSON files).
339 	 *
340 	 * Rebuild string to make alias->str member comparable.
341 	 */
342 	memset(newval, 0, sizeof(newval));
343 	ret = 0;
344 	list_for_each_entry(term, &alias->terms, list) {
345 		if (ret)
346 			ret += scnprintf(newval + ret, sizeof(newval) - ret,
347 					 ",");
348 		if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
349 			ret += scnprintf(newval + ret, sizeof(newval) - ret,
350 					 "%s=%#x", term->config, term->val.num);
351 		else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
352 			ret += scnprintf(newval + ret, sizeof(newval) - ret,
353 					 "%s=%s", term->config, term->val.str);
354 	}
355 
356 	alias->name = strdup(name);
357 	if (dir) {
358 		/*
359 		 * load unit name and scale if available
360 		 */
361 		perf_pmu__parse_unit(alias, dir, name);
362 		perf_pmu__parse_scale(alias, dir, name);
363 		perf_pmu__parse_per_pkg(alias, dir, name);
364 		perf_pmu__parse_snapshot(alias, dir, name);
365 	}
366 
367 	alias->metric_expr = metric_expr ? strdup(metric_expr) : NULL;
368 	alias->metric_name = metric_name ? strdup(metric_name): NULL;
369 	alias->desc = desc ? strdup(desc) : NULL;
370 	alias->long_desc = long_desc ? strdup(long_desc) :
371 				desc ? strdup(desc) : NULL;
372 	alias->topic = topic ? strdup(topic) : NULL;
373 	if (unit) {
374 		if (convert_scale(unit, &unit, &alias->scale) < 0)
375 			return -1;
376 		snprintf(alias->unit, sizeof(alias->unit), "%s", unit);
377 	}
378 	alias->per_pkg = perpkg && sscanf(perpkg, "%d", &num) == 1 && num == 1;
379 	alias->str = strdup(newval);
380 
381 	if (!perf_pmu_merge_alias(alias, list))
382 		list_add_tail(&alias->list, list);
383 
384 	return 0;
385 }
386 
387 static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FILE *file)
388 {
389 	char buf[256];
390 	int ret;
391 
392 	ret = fread(buf, 1, sizeof(buf), file);
393 	if (ret == 0)
394 		return -EINVAL;
395 
396 	buf[ret] = 0;
397 
398 	/* Remove trailing newline from sysfs file */
399 	strim(buf);
400 
401 	return __perf_pmu__new_alias(list, dir, name, NULL, buf, NULL, NULL, NULL,
402 				     NULL, NULL, NULL);
403 }
404 
405 static inline bool pmu_alias_info_file(char *name)
406 {
407 	size_t len;
408 
409 	len = strlen(name);
410 	if (len > 5 && !strcmp(name + len - 5, ".unit"))
411 		return true;
412 	if (len > 6 && !strcmp(name + len - 6, ".scale"))
413 		return true;
414 	if (len > 8 && !strcmp(name + len - 8, ".per-pkg"))
415 		return true;
416 	if (len > 9 && !strcmp(name + len - 9, ".snapshot"))
417 		return true;
418 
419 	return false;
420 }
421 
422 /*
423  * Process all the sysfs attributes located under the directory
424  * specified in 'dir' parameter.
425  */
426 static int pmu_aliases_parse(char *dir, struct list_head *head)
427 {
428 	struct dirent *evt_ent;
429 	DIR *event_dir;
430 
431 	event_dir = opendir(dir);
432 	if (!event_dir)
433 		return -EINVAL;
434 
435 	while ((evt_ent = readdir(event_dir))) {
436 		char path[PATH_MAX];
437 		char *name = evt_ent->d_name;
438 		FILE *file;
439 
440 		if (!strcmp(name, ".") || !strcmp(name, ".."))
441 			continue;
442 
443 		/*
444 		 * skip info files parsed in perf_pmu__new_alias()
445 		 */
446 		if (pmu_alias_info_file(name))
447 			continue;
448 
449 		scnprintf(path, PATH_MAX, "%s/%s", dir, name);
450 
451 		file = fopen(path, "r");
452 		if (!file) {
453 			pr_debug("Cannot open %s\n", path);
454 			continue;
455 		}
456 
457 		if (perf_pmu__new_alias(head, dir, name, file) < 0)
458 			pr_debug("Cannot set up %s\n", name);
459 		fclose(file);
460 	}
461 
462 	closedir(event_dir);
463 	return 0;
464 }
465 
466 /*
467  * Reading the pmu event aliases definition, which should be located at:
468  * /sys/bus/event_source/devices/<dev>/events as sysfs group attributes.
469  */
470 static int pmu_aliases(const char *name, struct list_head *head)
471 {
472 	struct stat st;
473 	char path[PATH_MAX];
474 	const char *sysfs = sysfs__mountpoint();
475 
476 	if (!sysfs)
477 		return -1;
478 
479 	snprintf(path, PATH_MAX,
480 		 "%s/bus/event_source/devices/%s/events", sysfs, name);
481 
482 	if (stat(path, &st) < 0)
483 		return 0;	 /* no error if 'events' does not exist */
484 
485 	if (pmu_aliases_parse(path, head))
486 		return -1;
487 
488 	return 0;
489 }
490 
491 static int pmu_alias_terms(struct perf_pmu_alias *alias,
492 			   struct list_head *terms)
493 {
494 	struct parse_events_term *term, *cloned;
495 	LIST_HEAD(list);
496 	int ret;
497 
498 	list_for_each_entry(term, &alias->terms, list) {
499 		ret = parse_events_term__clone(&cloned, term);
500 		if (ret) {
501 			parse_events_terms__purge(&list);
502 			return ret;
503 		}
504 		/*
505 		 * Weak terms don't override command line options,
506 		 * which we don't want for implicit terms in aliases.
507 		 */
508 		cloned->weak = true;
509 		list_add_tail(&cloned->list, &list);
510 	}
511 	list_splice(&list, terms);
512 	return 0;
513 }
514 
515 /*
516  * Reading/parsing the default pmu type value, which should be
517  * located at:
518  * /sys/bus/event_source/devices/<dev>/type as sysfs attribute.
519  */
520 static int pmu_type(const char *name, __u32 *type)
521 {
522 	struct stat st;
523 	char path[PATH_MAX];
524 	FILE *file;
525 	int ret = 0;
526 	const char *sysfs = sysfs__mountpoint();
527 
528 	if (!sysfs)
529 		return -1;
530 
531 	snprintf(path, PATH_MAX,
532 		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/type", sysfs, name);
533 
534 	if (stat(path, &st) < 0)
535 		return -1;
536 
537 	file = fopen(path, "r");
538 	if (!file)
539 		return -EINVAL;
540 
541 	if (1 != fscanf(file, "%u", type))
542 		ret = -1;
543 
544 	fclose(file);
545 	return ret;
546 }
547 
548 /* Add all pmus in sysfs to pmu list: */
549 static void pmu_read_sysfs(void)
550 {
551 	char path[PATH_MAX];
552 	DIR *dir;
553 	struct dirent *dent;
554 	const char *sysfs = sysfs__mountpoint();
555 
556 	if (!sysfs)
557 		return;
558 
559 	snprintf(path, PATH_MAX,
560 		 "%s" EVENT_SOURCE_DEVICE_PATH, sysfs);
561 
562 	dir = opendir(path);
563 	if (!dir)
564 		return;
565 
566 	while ((dent = readdir(dir))) {
567 		if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
568 			continue;
569 		/* add to static LIST_HEAD(pmus): */
570 		perf_pmu__find(dent->d_name);
571 	}
572 
573 	closedir(dir);
574 }
575 
576 static struct perf_cpu_map *__pmu_cpumask(const char *path)
577 {
578 	FILE *file;
579 	struct perf_cpu_map *cpus;
580 
581 	file = fopen(path, "r");
582 	if (!file)
583 		return NULL;
584 
585 	cpus = perf_cpu_map__read(file);
586 	fclose(file);
587 	return cpus;
588 }
589 
590 /*
591  * Uncore PMUs have a "cpumask" file under sysfs. CPU PMUs (e.g. on arm/arm64)
592  * may have a "cpus" file.
593  */
594 #define CPUS_TEMPLATE_UNCORE	"%s/bus/event_source/devices/%s/cpumask"
595 #define CPUS_TEMPLATE_CPU	"%s/bus/event_source/devices/%s/cpus"
596 
597 static struct perf_cpu_map *pmu_cpumask(const char *name)
598 {
599 	char path[PATH_MAX];
600 	struct perf_cpu_map *cpus;
601 	const char *sysfs = sysfs__mountpoint();
602 	const char *templates[] = {
603 		CPUS_TEMPLATE_UNCORE,
604 		CPUS_TEMPLATE_CPU,
605 		NULL
606 	};
607 	const char **template;
608 
609 	if (!sysfs)
610 		return NULL;
611 
612 	for (template = templates; *template; template++) {
613 		snprintf(path, PATH_MAX, *template, sysfs, name);
614 		cpus = __pmu_cpumask(path);
615 		if (cpus)
616 			return cpus;
617 	}
618 
619 	return NULL;
620 }
621 
622 static bool pmu_is_uncore(const char *name)
623 {
624 	char path[PATH_MAX];
625 	struct perf_cpu_map *cpus;
626 	const char *sysfs = sysfs__mountpoint();
627 
628 	snprintf(path, PATH_MAX, CPUS_TEMPLATE_UNCORE, sysfs, name);
629 	cpus = __pmu_cpumask(path);
630 	perf_cpu_map__put(cpus);
631 
632 	return !!cpus;
633 }
634 
635 /*
636  *  PMU CORE devices have different name other than cpu in sysfs on some
637  *  platforms.
638  *  Looking for possible sysfs files to identify the arm core device.
639  */
640 static int is_arm_pmu_core(const char *name)
641 {
642 	struct stat st;
643 	char path[PATH_MAX];
644 	const char *sysfs = sysfs__mountpoint();
645 
646 	if (!sysfs)
647 		return 0;
648 
649 	/* Look for cpu sysfs (specific to arm) */
650 	scnprintf(path, PATH_MAX, "%s/bus/event_source/devices/%s/cpus",
651 				sysfs, name);
652 	if (stat(path, &st) == 0)
653 		return 1;
654 
655 	return 0;
656 }
657 
658 static char *perf_pmu__getcpuid(struct perf_pmu *pmu)
659 {
660 	char *cpuid;
661 	static bool printed;
662 
663 	cpuid = getenv("PERF_CPUID");
664 	if (cpuid)
665 		cpuid = strdup(cpuid);
666 	if (!cpuid)
667 		cpuid = get_cpuid_str(pmu);
668 	if (!cpuid)
669 		return NULL;
670 
671 	if (!printed) {
672 		pr_debug("Using CPUID %s\n", cpuid);
673 		printed = true;
674 	}
675 	return cpuid;
676 }
677 
678 struct pmu_events_map *perf_pmu__find_map(struct perf_pmu *pmu)
679 {
680 	struct pmu_events_map *map;
681 	char *cpuid = perf_pmu__getcpuid(pmu);
682 	int i;
683 
684 	/* on some platforms which uses cpus map, cpuid can be NULL for
685 	 * PMUs other than CORE PMUs.
686 	 */
687 	if (!cpuid)
688 		return NULL;
689 
690 	i = 0;
691 	for (;;) {
692 		map = &pmu_events_map[i++];
693 		if (!map->table) {
694 			map = NULL;
695 			break;
696 		}
697 
698 		if (!strcmp_cpuid_str(map->cpuid, cpuid))
699 			break;
700 	}
701 	free(cpuid);
702 	return map;
703 }
704 
705 static bool pmu_uncore_alias_match(const char *pmu_name, const char *name)
706 {
707 	char *tmp = NULL, *tok, *str;
708 	bool res;
709 
710 	str = strdup(pmu_name);
711 	if (!str)
712 		return false;
713 
714 	/*
715 	 * uncore alias may be from different PMU with common prefix
716 	 */
717 	tok = strtok_r(str, ",", &tmp);
718 	if (strncmp(pmu_name, tok, strlen(tok))) {
719 		res = false;
720 		goto out;
721 	}
722 
723 	/*
724 	 * Match more complex aliases where the alias name is a comma-delimited
725 	 * list of tokens, orderly contained in the matching PMU name.
726 	 *
727 	 * Example: For alias "socket,pmuname" and PMU "socketX_pmunameY", we
728 	 *	    match "socket" in "socketX_pmunameY" and then "pmuname" in
729 	 *	    "pmunameY".
730 	 */
731 	for (; tok; name += strlen(tok), tok = strtok_r(NULL, ",", &tmp)) {
732 		name = strstr(name, tok);
733 		if (!name) {
734 			res = false;
735 			goto out;
736 		}
737 	}
738 
739 	res = true;
740 out:
741 	free(str);
742 	return res;
743 }
744 
745 /*
746  * From the pmu_events_map, find the table of PMU events that corresponds
747  * to the current running CPU. Then, add all PMU events from that table
748  * as aliases.
749  */
750 static void pmu_add_cpu_aliases(struct list_head *head, struct perf_pmu *pmu)
751 {
752 	int i;
753 	struct pmu_events_map *map;
754 	const char *name = pmu->name;
755 
756 	map = perf_pmu__find_map(pmu);
757 	if (!map)
758 		return;
759 
760 	/*
761 	 * Found a matching PMU events table. Create aliases
762 	 */
763 	i = 0;
764 	while (1) {
765 		const char *cpu_name = is_arm_pmu_core(name) ? name : "cpu";
766 		struct pmu_event *pe = &map->table[i++];
767 		const char *pname = pe->pmu ? pe->pmu : cpu_name;
768 
769 		if (!pe->name) {
770 			if (pe->metric_group || pe->metric_name)
771 				continue;
772 			break;
773 		}
774 
775 		if (pmu_is_uncore(name) &&
776 		    pmu_uncore_alias_match(pname, name))
777 			goto new_alias;
778 
779 		if (strcmp(pname, name))
780 			continue;
781 
782 new_alias:
783 		/* need type casts to override 'const' */
784 		__perf_pmu__new_alias(head, NULL, (char *)pe->name,
785 				(char *)pe->desc, (char *)pe->event,
786 				(char *)pe->long_desc, (char *)pe->topic,
787 				(char *)pe->unit, (char *)pe->perpkg,
788 				(char *)pe->metric_expr,
789 				(char *)pe->metric_name);
790 	}
791 }
792 
793 struct perf_event_attr * __weak
794 perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
795 {
796 	return NULL;
797 }
798 
799 static int pmu_max_precise(const char *name)
800 {
801 	char path[PATH_MAX];
802 	int max_precise = -1;
803 
804 	scnprintf(path, PATH_MAX,
805 		 "bus/event_source/devices/%s/caps/max_precise",
806 		 name);
807 
808 	sysfs__read_int(path, &max_precise);
809 	return max_precise;
810 }
811 
812 static struct perf_pmu *pmu_lookup(const char *name)
813 {
814 	struct perf_pmu *pmu;
815 	LIST_HEAD(format);
816 	LIST_HEAD(aliases);
817 	__u32 type;
818 
819 	/*
820 	 * The pmu data we store & need consists of the pmu
821 	 * type value and format definitions. Load both right
822 	 * now.
823 	 */
824 	if (pmu_format(name, &format))
825 		return NULL;
826 
827 	/*
828 	 * Check the type first to avoid unnecessary work.
829 	 */
830 	if (pmu_type(name, &type))
831 		return NULL;
832 
833 	if (pmu_aliases(name, &aliases))
834 		return NULL;
835 
836 	pmu = zalloc(sizeof(*pmu));
837 	if (!pmu)
838 		return NULL;
839 
840 	pmu->cpus = pmu_cpumask(name);
841 	pmu->name = strdup(name);
842 	pmu->type = type;
843 	pmu->is_uncore = pmu_is_uncore(name);
844 	pmu->max_precise = pmu_max_precise(name);
845 	pmu_add_cpu_aliases(&aliases, pmu);
846 
847 	INIT_LIST_HEAD(&pmu->format);
848 	INIT_LIST_HEAD(&pmu->aliases);
849 	list_splice(&format, &pmu->format);
850 	list_splice(&aliases, &pmu->aliases);
851 	list_add_tail(&pmu->list, &pmus);
852 
853 	pmu->default_config = perf_pmu__get_default_config(pmu);
854 
855 	return pmu;
856 }
857 
858 static struct perf_pmu *pmu_find(const char *name)
859 {
860 	struct perf_pmu *pmu;
861 
862 	list_for_each_entry(pmu, &pmus, list)
863 		if (!strcmp(pmu->name, name))
864 			return pmu;
865 
866 	return NULL;
867 }
868 
869 struct perf_pmu *perf_pmu__scan(struct perf_pmu *pmu)
870 {
871 	/*
872 	 * pmu iterator: If pmu is NULL, we start at the begin,
873 	 * otherwise return the next pmu. Returns NULL on end.
874 	 */
875 	if (!pmu) {
876 		pmu_read_sysfs();
877 		pmu = list_prepare_entry(pmu, &pmus, list);
878 	}
879 	list_for_each_entry_continue(pmu, &pmus, list)
880 		return pmu;
881 	return NULL;
882 }
883 
884 struct perf_pmu *perf_pmu__find(const char *name)
885 {
886 	struct perf_pmu *pmu;
887 
888 	/*
889 	 * Once PMU is loaded it stays in the list,
890 	 * so we keep us from multiple reading/parsing
891 	 * the pmu format definitions.
892 	 */
893 	pmu = pmu_find(name);
894 	if (pmu)
895 		return pmu;
896 
897 	return pmu_lookup(name);
898 }
899 
900 static struct perf_pmu_format *
901 pmu_find_format(struct list_head *formats, const char *name)
902 {
903 	struct perf_pmu_format *format;
904 
905 	list_for_each_entry(format, formats, list)
906 		if (!strcmp(format->name, name))
907 			return format;
908 
909 	return NULL;
910 }
911 
912 __u64 perf_pmu__format_bits(struct list_head *formats, const char *name)
913 {
914 	struct perf_pmu_format *format = pmu_find_format(formats, name);
915 	__u64 bits = 0;
916 	int fbit;
917 
918 	if (!format)
919 		return 0;
920 
921 	for_each_set_bit(fbit, format->bits, PERF_PMU_FORMAT_BITS)
922 		bits |= 1ULL << fbit;
923 
924 	return bits;
925 }
926 
927 /*
928  * Sets value based on the format definition (format parameter)
929  * and unformated value (value parameter).
930  */
931 static void pmu_format_value(unsigned long *format, __u64 value, __u64 *v,
932 			     bool zero)
933 {
934 	unsigned long fbit, vbit;
935 
936 	for (fbit = 0, vbit = 0; fbit < PERF_PMU_FORMAT_BITS; fbit++) {
937 
938 		if (!test_bit(fbit, format))
939 			continue;
940 
941 		if (value & (1llu << vbit++))
942 			*v |= (1llu << fbit);
943 		else if (zero)
944 			*v &= ~(1llu << fbit);
945 	}
946 }
947 
948 static __u64 pmu_format_max_value(const unsigned long *format)
949 {
950 	int w;
951 
952 	w = bitmap_weight(format, PERF_PMU_FORMAT_BITS);
953 	if (!w)
954 		return 0;
955 	if (w < 64)
956 		return (1ULL << w) - 1;
957 	return -1;
958 }
959 
960 /*
961  * Term is a string term, and might be a param-term. Try to look up it's value
962  * in the remaining terms.
963  * - We have a term like "base-or-format-term=param-term",
964  * - We need to find the value supplied for "param-term" (with param-term named
965  *   in a config string) later on in the term list.
966  */
967 static int pmu_resolve_param_term(struct parse_events_term *term,
968 				  struct list_head *head_terms,
969 				  __u64 *value)
970 {
971 	struct parse_events_term *t;
972 
973 	list_for_each_entry(t, head_terms, list) {
974 		if (t->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
975 			if (!strcmp(t->config, term->config)) {
976 				t->used = true;
977 				*value = t->val.num;
978 				return 0;
979 			}
980 		}
981 	}
982 
983 	if (verbose > 0)
984 		printf("Required parameter '%s' not specified\n", term->config);
985 
986 	return -1;
987 }
988 
989 static char *pmu_formats_string(struct list_head *formats)
990 {
991 	struct perf_pmu_format *format;
992 	char *str = NULL;
993 	struct strbuf buf = STRBUF_INIT;
994 	unsigned i = 0;
995 
996 	if (!formats)
997 		return NULL;
998 
999 	/* sysfs exported terms */
1000 	list_for_each_entry(format, formats, list)
1001 		if (strbuf_addf(&buf, i++ ? ",%s" : "%s", format->name) < 0)
1002 			goto error;
1003 
1004 	str = strbuf_detach(&buf, NULL);
1005 error:
1006 	strbuf_release(&buf);
1007 
1008 	return str;
1009 }
1010 
1011 /*
1012  * Setup one of config[12] attr members based on the
1013  * user input data - term parameter.
1014  */
1015 static int pmu_config_term(struct list_head *formats,
1016 			   struct perf_event_attr *attr,
1017 			   struct parse_events_term *term,
1018 			   struct list_head *head_terms,
1019 			   bool zero, struct parse_events_error *err)
1020 {
1021 	struct perf_pmu_format *format;
1022 	__u64 *vp;
1023 	__u64 val, max_val;
1024 
1025 	/*
1026 	 * If this is a parameter we've already used for parameterized-eval,
1027 	 * skip it in normal eval.
1028 	 */
1029 	if (term->used)
1030 		return 0;
1031 
1032 	/*
1033 	 * Hardcoded terms should be already in, so nothing
1034 	 * to be done for them.
1035 	 */
1036 	if (parse_events__is_hardcoded_term(term))
1037 		return 0;
1038 
1039 	format = pmu_find_format(formats, term->config);
1040 	if (!format) {
1041 		if (verbose > 0)
1042 			printf("Invalid event/parameter '%s'\n", term->config);
1043 		if (err) {
1044 			char *pmu_term = pmu_formats_string(formats);
1045 
1046 			err->idx  = term->err_term;
1047 			err->str  = strdup("unknown term");
1048 			err->help = parse_events_formats_error_string(pmu_term);
1049 			free(pmu_term);
1050 		}
1051 		return -EINVAL;
1052 	}
1053 
1054 	switch (format->value) {
1055 	case PERF_PMU_FORMAT_VALUE_CONFIG:
1056 		vp = &attr->config;
1057 		break;
1058 	case PERF_PMU_FORMAT_VALUE_CONFIG1:
1059 		vp = &attr->config1;
1060 		break;
1061 	case PERF_PMU_FORMAT_VALUE_CONFIG2:
1062 		vp = &attr->config2;
1063 		break;
1064 	default:
1065 		return -EINVAL;
1066 	}
1067 
1068 	/*
1069 	 * Either directly use a numeric term, or try to translate string terms
1070 	 * using event parameters.
1071 	 */
1072 	if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
1073 		if (term->no_value &&
1074 		    bitmap_weight(format->bits, PERF_PMU_FORMAT_BITS) > 1) {
1075 			if (err) {
1076 				err->idx = term->err_val;
1077 				err->str = strdup("no value assigned for term");
1078 			}
1079 			return -EINVAL;
1080 		}
1081 
1082 		val = term->val.num;
1083 	} else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
1084 		if (strcmp(term->val.str, "?")) {
1085 			if (verbose > 0) {
1086 				pr_info("Invalid sysfs entry %s=%s\n",
1087 						term->config, term->val.str);
1088 			}
1089 			if (err) {
1090 				err->idx = term->err_val;
1091 				err->str = strdup("expected numeric value");
1092 			}
1093 			return -EINVAL;
1094 		}
1095 
1096 		if (pmu_resolve_param_term(term, head_terms, &val))
1097 			return -EINVAL;
1098 	} else
1099 		return -EINVAL;
1100 
1101 	max_val = pmu_format_max_value(format->bits);
1102 	if (val > max_val) {
1103 		if (err) {
1104 			err->idx = term->err_val;
1105 			if (asprintf(&err->str,
1106 				     "value too big for format, maximum is %llu",
1107 				     (unsigned long long)max_val) < 0)
1108 				err->str = strdup("value too big for format");
1109 			return -EINVAL;
1110 		}
1111 		/*
1112 		 * Assume we don't care if !err, in which case the value will be
1113 		 * silently truncated.
1114 		 */
1115 	}
1116 
1117 	pmu_format_value(format->bits, val, vp, zero);
1118 	return 0;
1119 }
1120 
1121 int perf_pmu__config_terms(struct list_head *formats,
1122 			   struct perf_event_attr *attr,
1123 			   struct list_head *head_terms,
1124 			   bool zero, struct parse_events_error *err)
1125 {
1126 	struct parse_events_term *term;
1127 
1128 	list_for_each_entry(term, head_terms, list) {
1129 		if (pmu_config_term(formats, attr, term, head_terms,
1130 				    zero, err))
1131 			return -EINVAL;
1132 	}
1133 
1134 	return 0;
1135 }
1136 
1137 /*
1138  * Configures event's 'attr' parameter based on the:
1139  * 1) users input - specified in terms parameter
1140  * 2) pmu format definitions - specified by pmu parameter
1141  */
1142 int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
1143 		     struct list_head *head_terms,
1144 		     struct parse_events_error *err)
1145 {
1146 	bool zero = !!pmu->default_config;
1147 
1148 	attr->type = pmu->type;
1149 	return perf_pmu__config_terms(&pmu->format, attr, head_terms,
1150 				      zero, err);
1151 }
1152 
1153 static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
1154 					     struct parse_events_term *term)
1155 {
1156 	struct perf_pmu_alias *alias;
1157 	char *name;
1158 
1159 	if (parse_events__is_hardcoded_term(term))
1160 		return NULL;
1161 
1162 	if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
1163 		if (term->val.num != 1)
1164 			return NULL;
1165 		if (pmu_find_format(&pmu->format, term->config))
1166 			return NULL;
1167 		name = term->config;
1168 	} else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
1169 		if (strcasecmp(term->config, "event"))
1170 			return NULL;
1171 		name = term->val.str;
1172 	} else {
1173 		return NULL;
1174 	}
1175 
1176 	list_for_each_entry(alias, &pmu->aliases, list) {
1177 		if (!strcasecmp(alias->name, name))
1178 			return alias;
1179 	}
1180 	return NULL;
1181 }
1182 
1183 
1184 static int check_info_data(struct perf_pmu_alias *alias,
1185 			   struct perf_pmu_info *info)
1186 {
1187 	/*
1188 	 * Only one term in event definition can
1189 	 * define unit, scale and snapshot, fail
1190 	 * if there's more than one.
1191 	 */
1192 	if ((info->unit && alias->unit[0]) ||
1193 	    (info->scale && alias->scale) ||
1194 	    (info->snapshot && alias->snapshot))
1195 		return -EINVAL;
1196 
1197 	if (alias->unit[0])
1198 		info->unit = alias->unit;
1199 
1200 	if (alias->scale)
1201 		info->scale = alias->scale;
1202 
1203 	if (alias->snapshot)
1204 		info->snapshot = alias->snapshot;
1205 
1206 	return 0;
1207 }
1208 
1209 /*
1210  * Find alias in the terms list and replace it with the terms
1211  * defined for the alias
1212  */
1213 int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
1214 			  struct perf_pmu_info *info)
1215 {
1216 	struct parse_events_term *term, *h;
1217 	struct perf_pmu_alias *alias;
1218 	int ret;
1219 
1220 	info->per_pkg = false;
1221 
1222 	/*
1223 	 * Mark unit and scale as not set
1224 	 * (different from default values, see below)
1225 	 */
1226 	info->unit     = NULL;
1227 	info->scale    = 0.0;
1228 	info->snapshot = false;
1229 	info->metric_expr = NULL;
1230 	info->metric_name = NULL;
1231 
1232 	list_for_each_entry_safe(term, h, head_terms, list) {
1233 		alias = pmu_find_alias(pmu, term);
1234 		if (!alias)
1235 			continue;
1236 		ret = pmu_alias_terms(alias, &term->list);
1237 		if (ret)
1238 			return ret;
1239 
1240 		ret = check_info_data(alias, info);
1241 		if (ret)
1242 			return ret;
1243 
1244 		if (alias->per_pkg)
1245 			info->per_pkg = true;
1246 		info->metric_expr = alias->metric_expr;
1247 		info->metric_name = alias->metric_name;
1248 
1249 		list_del_init(&term->list);
1250 		free(term);
1251 	}
1252 
1253 	/*
1254 	 * if no unit or scale foundin aliases, then
1255 	 * set defaults as for evsel
1256 	 * unit cannot left to NULL
1257 	 */
1258 	if (info->unit == NULL)
1259 		info->unit   = "";
1260 
1261 	if (info->scale == 0.0)
1262 		info->scale  = 1.0;
1263 
1264 	return 0;
1265 }
1266 
1267 int perf_pmu__new_format(struct list_head *list, char *name,
1268 			 int config, unsigned long *bits)
1269 {
1270 	struct perf_pmu_format *format;
1271 
1272 	format = zalloc(sizeof(*format));
1273 	if (!format)
1274 		return -ENOMEM;
1275 
1276 	format->name = strdup(name);
1277 	format->value = config;
1278 	memcpy(format->bits, bits, sizeof(format->bits));
1279 
1280 	list_add_tail(&format->list, list);
1281 	return 0;
1282 }
1283 
1284 void perf_pmu__set_format(unsigned long *bits, long from, long to)
1285 {
1286 	long b;
1287 
1288 	if (!to)
1289 		to = from;
1290 
1291 	memset(bits, 0, BITS_TO_BYTES(PERF_PMU_FORMAT_BITS));
1292 	for (b = from; b <= to; b++)
1293 		set_bit(b, bits);
1294 }
1295 
1296 static int sub_non_neg(int a, int b)
1297 {
1298 	if (b > a)
1299 		return 0;
1300 	return a - b;
1301 }
1302 
1303 static char *format_alias(char *buf, int len, struct perf_pmu *pmu,
1304 			  struct perf_pmu_alias *alias)
1305 {
1306 	struct parse_events_term *term;
1307 	int used = snprintf(buf, len, "%s/%s", pmu->name, alias->name);
1308 
1309 	list_for_each_entry(term, &alias->terms, list) {
1310 		if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR)
1311 			used += snprintf(buf + used, sub_non_neg(len, used),
1312 					",%s=%s", term->config,
1313 					term->val.str);
1314 	}
1315 
1316 	if (sub_non_neg(len, used) > 0) {
1317 		buf[used] = '/';
1318 		used++;
1319 	}
1320 	if (sub_non_neg(len, used) > 0) {
1321 		buf[used] = '\0';
1322 		used++;
1323 	} else
1324 		buf[len - 1] = '\0';
1325 
1326 	return buf;
1327 }
1328 
1329 static char *format_alias_or(char *buf, int len, struct perf_pmu *pmu,
1330 			     struct perf_pmu_alias *alias)
1331 {
1332 	snprintf(buf, len, "%s OR %s/%s/", alias->name, pmu->name, alias->name);
1333 	return buf;
1334 }
1335 
1336 struct sevent {
1337 	char *name;
1338 	char *desc;
1339 	char *topic;
1340 	char *str;
1341 	char *pmu;
1342 	char *metric_expr;
1343 	char *metric_name;
1344 };
1345 
1346 static int cmp_sevent(const void *a, const void *b)
1347 {
1348 	const struct sevent *as = a;
1349 	const struct sevent *bs = b;
1350 
1351 	/* Put extra events last */
1352 	if (!!as->desc != !!bs->desc)
1353 		return !!as->desc - !!bs->desc;
1354 	if (as->topic && bs->topic) {
1355 		int n = strcmp(as->topic, bs->topic);
1356 
1357 		if (n)
1358 			return n;
1359 	}
1360 	return strcmp(as->name, bs->name);
1361 }
1362 
1363 static void wordwrap(char *s, int start, int max, int corr)
1364 {
1365 	int column = start;
1366 	int n;
1367 
1368 	while (*s) {
1369 		int wlen = strcspn(s, " \t");
1370 
1371 		if (column + wlen >= max && column > start) {
1372 			printf("\n%*s", start, "");
1373 			column = start + corr;
1374 		}
1375 		n = printf("%s%.*s", column > start ? " " : "", wlen, s);
1376 		if (n <= 0)
1377 			break;
1378 		s += wlen;
1379 		column += n;
1380 		s = skip_spaces(s);
1381 	}
1382 }
1383 
1384 void print_pmu_events(const char *event_glob, bool name_only, bool quiet_flag,
1385 			bool long_desc, bool details_flag)
1386 {
1387 	struct perf_pmu *pmu;
1388 	struct perf_pmu_alias *alias;
1389 	char buf[1024];
1390 	int printed = 0;
1391 	int len, j;
1392 	struct sevent *aliases;
1393 	int numdesc = 0;
1394 	int columns = pager_get_columns();
1395 	char *topic = NULL;
1396 
1397 	pmu = NULL;
1398 	len = 0;
1399 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
1400 		list_for_each_entry(alias, &pmu->aliases, list)
1401 			len++;
1402 		if (pmu->selectable)
1403 			len++;
1404 	}
1405 	aliases = zalloc(sizeof(struct sevent) * len);
1406 	if (!aliases)
1407 		goto out_enomem;
1408 	pmu = NULL;
1409 	j = 0;
1410 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
1411 		list_for_each_entry(alias, &pmu->aliases, list) {
1412 			char *name = alias->desc ? alias->name :
1413 				format_alias(buf, sizeof(buf), pmu, alias);
1414 			bool is_cpu = !strcmp(pmu->name, "cpu");
1415 
1416 			if (event_glob != NULL &&
1417 			    !(strglobmatch_nocase(name, event_glob) ||
1418 			      (!is_cpu && strglobmatch_nocase(alias->name,
1419 						       event_glob)) ||
1420 			      (alias->topic &&
1421 			       strglobmatch_nocase(alias->topic, event_glob))))
1422 				continue;
1423 
1424 			if (is_cpu && !name_only && !alias->desc)
1425 				name = format_alias_or(buf, sizeof(buf), pmu, alias);
1426 
1427 			aliases[j].name = name;
1428 			if (is_cpu && !name_only && !alias->desc)
1429 				aliases[j].name = format_alias_or(buf,
1430 								  sizeof(buf),
1431 								  pmu, alias);
1432 			aliases[j].name = strdup(aliases[j].name);
1433 			if (!aliases[j].name)
1434 				goto out_enomem;
1435 
1436 			aliases[j].desc = long_desc ? alias->long_desc :
1437 						alias->desc;
1438 			aliases[j].topic = alias->topic;
1439 			aliases[j].str = alias->str;
1440 			aliases[j].pmu = pmu->name;
1441 			aliases[j].metric_expr = alias->metric_expr;
1442 			aliases[j].metric_name = alias->metric_name;
1443 			j++;
1444 		}
1445 		if (pmu->selectable &&
1446 		    (event_glob == NULL || strglobmatch(pmu->name, event_glob))) {
1447 			char *s;
1448 			if (asprintf(&s, "%s//", pmu->name) < 0)
1449 				goto out_enomem;
1450 			aliases[j].name = s;
1451 			j++;
1452 		}
1453 	}
1454 	len = j;
1455 	qsort(aliases, len, sizeof(struct sevent), cmp_sevent);
1456 	for (j = 0; j < len; j++) {
1457 		/* Skip duplicates */
1458 		if (j > 0 && !strcmp(aliases[j].name, aliases[j - 1].name))
1459 			continue;
1460 		if (name_only) {
1461 			printf("%s ", aliases[j].name);
1462 			continue;
1463 		}
1464 		if (aliases[j].desc && !quiet_flag) {
1465 			if (numdesc++ == 0)
1466 				printf("\n");
1467 			if (aliases[j].topic && (!topic ||
1468 					strcmp(topic, aliases[j].topic))) {
1469 				printf("%s%s:\n", topic ? "\n" : "",
1470 						aliases[j].topic);
1471 				topic = aliases[j].topic;
1472 			}
1473 			printf("  %-50s\n", aliases[j].name);
1474 			printf("%*s", 8, "[");
1475 			wordwrap(aliases[j].desc, 8, columns, 0);
1476 			printf("]\n");
1477 			if (details_flag) {
1478 				printf("%*s%s/%s/ ", 8, "", aliases[j].pmu, aliases[j].str);
1479 				if (aliases[j].metric_name)
1480 					printf(" MetricName: %s", aliases[j].metric_name);
1481 				if (aliases[j].metric_expr)
1482 					printf(" MetricExpr: %s", aliases[j].metric_expr);
1483 				putchar('\n');
1484 			}
1485 		} else
1486 			printf("  %-50s [Kernel PMU event]\n", aliases[j].name);
1487 		printed++;
1488 	}
1489 	if (printed && pager_in_use())
1490 		printf("\n");
1491 out_free:
1492 	for (j = 0; j < len; j++)
1493 		zfree(&aliases[j].name);
1494 	zfree(&aliases);
1495 	return;
1496 
1497 out_enomem:
1498 	printf("FATAL: not enough memory to print PMU events\n");
1499 	if (aliases)
1500 		goto out_free;
1501 }
1502 
1503 bool pmu_have_event(const char *pname, const char *name)
1504 {
1505 	struct perf_pmu *pmu;
1506 	struct perf_pmu_alias *alias;
1507 
1508 	pmu = NULL;
1509 	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
1510 		if (strcmp(pname, pmu->name))
1511 			continue;
1512 		list_for_each_entry(alias, &pmu->aliases, list)
1513 			if (!strcmp(alias->name, name))
1514 				return true;
1515 	}
1516 	return false;
1517 }
1518 
1519 static FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
1520 {
1521 	struct stat st;
1522 	char path[PATH_MAX];
1523 	const char *sysfs;
1524 
1525 	sysfs = sysfs__mountpoint();
1526 	if (!sysfs)
1527 		return NULL;
1528 
1529 	snprintf(path, PATH_MAX,
1530 		 "%s" EVENT_SOURCE_DEVICE_PATH "%s/%s", sysfs, pmu->name, name);
1531 
1532 	if (stat(path, &st) < 0)
1533 		return NULL;
1534 
1535 	return fopen(path, "r");
1536 }
1537 
1538 int perf_pmu__scan_file(struct perf_pmu *pmu, const char *name, const char *fmt,
1539 			...)
1540 {
1541 	va_list args;
1542 	FILE *file;
1543 	int ret = EOF;
1544 
1545 	va_start(args, fmt);
1546 	file = perf_pmu__open_file(pmu, name);
1547 	if (file) {
1548 		ret = vfscanf(file, fmt, args);
1549 		fclose(file);
1550 	}
1551 	va_end(args);
1552 	return ret;
1553 }
1554