1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Basic resctrl file system operations
4 *
5 * Copyright (C) 2018 Intel Corporation
6 *
7 * Authors:
8 *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
9 *    Fenghua Yu <fenghua.yu@intel.com>
10 */
11#include <fcntl.h>
12#include <limits.h>
13
14#include "resctrl.h"
15
16static int find_resctrl_mount(char *buffer)
17{
18	FILE *mounts;
19	char line[256], *fs, *mntpoint;
20
21	mounts = fopen("/proc/mounts", "r");
22	if (!mounts) {
23		ksft_perror("/proc/mounts");
24		return -ENXIO;
25	}
26	while (!feof(mounts)) {
27		if (!fgets(line, 256, mounts))
28			break;
29		fs = strtok(line, " \t");
30		if (!fs)
31			continue;
32		mntpoint = strtok(NULL, " \t");
33		if (!mntpoint)
34			continue;
35		fs = strtok(NULL, " \t");
36		if (!fs)
37			continue;
38		if (strcmp(fs, "resctrl"))
39			continue;
40
41		fclose(mounts);
42		if (buffer)
43			strncpy(buffer, mntpoint, 256);
44
45		return 0;
46	}
47
48	fclose(mounts);
49
50	return -ENOENT;
51}
52
53/*
54 * mount_resctrlfs - Mount resctrl FS at /sys/fs/resctrl
55 *
56 * Mounts resctrl FS. Fails if resctrl FS is already mounted to avoid
57 * pre-existing settings interfering with the test results.
58 *
59 * Return: 0 on success, < 0 on error.
60 */
61int mount_resctrlfs(void)
62{
63	int ret;
64
65	ret = find_resctrl_mount(NULL);
66	if (ret != -ENOENT)
67		return -1;
68
69	ksft_print_msg("Mounting resctrl to \"%s\"\n", RESCTRL_PATH);
70	ret = mount("resctrl", RESCTRL_PATH, "resctrl", 0, NULL);
71	if (ret)
72		ksft_perror("mount");
73
74	return ret;
75}
76
77int umount_resctrlfs(void)
78{
79	char mountpoint[256];
80	int ret;
81
82	ret = find_resctrl_mount(mountpoint);
83	if (ret == -ENOENT)
84		return 0;
85	if (ret)
86		return ret;
87
88	if (umount(mountpoint)) {
89		ksft_perror("Unable to umount resctrl");
90
91		return -1;
92	}
93
94	return 0;
95}
96
97/*
98 * get_cache_level - Convert cache level from string to integer
99 * @cache_type:		Cache level as string
100 *
101 * Return: cache level as integer or -1 if @cache_type is invalid.
102 */
103static int get_cache_level(const char *cache_type)
104{
105	if (!strcmp(cache_type, "L3"))
106		return 3;
107	if (!strcmp(cache_type, "L2"))
108		return 2;
109
110	ksft_print_msg("Invalid cache level\n");
111	return -1;
112}
113
114static int get_resource_cache_level(const char *resource)
115{
116	/* "MB" use L3 (LLC) as resource */
117	if (!strcmp(resource, "MB"))
118		return 3;
119	return get_cache_level(resource);
120}
121
122/*
123 * get_domain_id - Get resctrl domain ID for a specified CPU
124 * @resource:	resource name
125 * @cpu_no:	CPU number
126 * @domain_id:	domain ID (cache ID; for MB, L3 cache ID)
127 *
128 * Return: >= 0 on success, < 0 on failure.
129 */
130int get_domain_id(const char *resource, int cpu_no, int *domain_id)
131{
132	char phys_pkg_path[1024];
133	int cache_num;
134	FILE *fp;
135
136	cache_num = get_resource_cache_level(resource);
137	if (cache_num < 0)
138		return cache_num;
139
140	sprintf(phys_pkg_path, "%s%d/cache/index%d/id", PHYS_ID_PATH, cpu_no, cache_num);
141
142	fp = fopen(phys_pkg_path, "r");
143	if (!fp) {
144		ksft_perror("Failed to open cache id file");
145
146		return -1;
147	}
148	if (fscanf(fp, "%d", domain_id) <= 0) {
149		ksft_perror("Could not get domain ID");
150		fclose(fp);
151
152		return -1;
153	}
154	fclose(fp);
155
156	return 0;
157}
158
159/*
160 * get_cache_size - Get cache size for a specified CPU
161 * @cpu_no:	CPU number
162 * @cache_type:	Cache level L2/L3
163 * @cache_size:	pointer to cache_size
164 *
165 * Return: = 0 on success, < 0 on failure.
166 */
167int get_cache_size(int cpu_no, const char *cache_type, unsigned long *cache_size)
168{
169	char cache_path[1024], cache_str[64];
170	int length, i, cache_num;
171	FILE *fp;
172
173	cache_num = get_cache_level(cache_type);
174	if (cache_num < 0)
175		return cache_num;
176
177	sprintf(cache_path, "/sys/bus/cpu/devices/cpu%d/cache/index%d/size",
178		cpu_no, cache_num);
179	fp = fopen(cache_path, "r");
180	if (!fp) {
181		ksft_perror("Failed to open cache size");
182
183		return -1;
184	}
185	if (fscanf(fp, "%s", cache_str) <= 0) {
186		ksft_perror("Could not get cache_size");
187		fclose(fp);
188
189		return -1;
190	}
191	fclose(fp);
192
193	length = (int)strlen(cache_str);
194
195	*cache_size = 0;
196
197	for (i = 0; i < length; i++) {
198		if ((cache_str[i] >= '0') && (cache_str[i] <= '9'))
199
200			*cache_size = *cache_size * 10 + (cache_str[i] - '0');
201
202		else if (cache_str[i] == 'K')
203
204			*cache_size = *cache_size * 1024;
205
206		else if (cache_str[i] == 'M')
207
208			*cache_size = *cache_size * 1024 * 1024;
209
210		else
211			break;
212	}
213
214	return 0;
215}
216
217#define CORE_SIBLINGS_PATH	"/sys/bus/cpu/devices/cpu"
218
219/*
220 * get_bit_mask - Get bit mask from given file
221 * @filename:	File containing the mask
222 * @mask:	The bit mask returned as unsigned long
223 *
224 * Return: = 0 on success, < 0 on failure.
225 */
226static int get_bit_mask(const char *filename, unsigned long *mask)
227{
228	FILE *fp;
229
230	if (!filename || !mask)
231		return -1;
232
233	fp = fopen(filename, "r");
234	if (!fp) {
235		ksft_print_msg("Failed to open bit mask file '%s': %s\n",
236			       filename, strerror(errno));
237		return -1;
238	}
239
240	if (fscanf(fp, "%lx", mask) <= 0) {
241		ksft_print_msg("Could not read bit mask file '%s': %s\n",
242			       filename, strerror(errno));
243		fclose(fp);
244
245		return -1;
246	}
247	fclose(fp);
248
249	return 0;
250}
251
252/*
253 * resource_info_unsigned_get - Read an unsigned value from
254 * /sys/fs/resctrl/info/@resource/@filename
255 * @resource:	Resource name that matches directory name in
256 *		/sys/fs/resctrl/info
257 * @filename:	File in /sys/fs/resctrl/info/@resource
258 * @val:	Contains read value on success.
259 *
260 * Return: = 0 on success, < 0 on failure. On success the read
261 * value is saved into @val.
262 */
263int resource_info_unsigned_get(const char *resource, const char *filename,
264			       unsigned int *val)
265{
266	char file_path[PATH_MAX];
267	FILE *fp;
268
269	snprintf(file_path, sizeof(file_path), "%s/%s/%s", INFO_PATH, resource,
270		 filename);
271
272	fp = fopen(file_path, "r");
273	if (!fp) {
274		ksft_print_msg("Error opening %s: %m\n", file_path);
275		return -1;
276	}
277
278	if (fscanf(fp, "%u", val) <= 0) {
279		ksft_print_msg("Could not get contents of %s: %m\n", file_path);
280		fclose(fp);
281		return -1;
282	}
283
284	fclose(fp);
285	return 0;
286}
287
288/*
289 * create_bit_mask- Create bit mask from start, len pair
290 * @start:	LSB of the mask
291 * @len		Number of bits in the mask
292 */
293unsigned long create_bit_mask(unsigned int start, unsigned int len)
294{
295	return ((1UL << len) - 1UL) << start;
296}
297
298/*
299 * count_contiguous_bits - Returns the longest train of bits in a bit mask
300 * @val		A bit mask
301 * @start	The location of the least-significant bit of the longest train
302 *
303 * Return:	The length of the contiguous bits in the longest train of bits
304 */
305unsigned int count_contiguous_bits(unsigned long val, unsigned int *start)
306{
307	unsigned long last_val;
308	unsigned int count = 0;
309
310	while (val) {
311		last_val = val;
312		val &= (val >> 1);
313		count++;
314	}
315
316	if (start) {
317		if (count)
318			*start = ffsl(last_val) - 1;
319		else
320			*start = 0;
321	}
322
323	return count;
324}
325
326/*
327 * get_full_cbm - Get full Cache Bit Mask (CBM)
328 * @cache_type:	Cache type as "L2" or "L3"
329 * @mask:	Full cache bit mask representing the maximal portion of cache
330 *		available for allocation, returned as unsigned long.
331 *
332 * Return: = 0 on success, < 0 on failure.
333 */
334int get_full_cbm(const char *cache_type, unsigned long *mask)
335{
336	char cbm_path[PATH_MAX];
337	int ret;
338
339	if (!cache_type)
340		return -1;
341
342	snprintf(cbm_path, sizeof(cbm_path), "%s/%s/cbm_mask",
343		 INFO_PATH, cache_type);
344
345	ret = get_bit_mask(cbm_path, mask);
346	if (ret || !*mask)
347		return -1;
348
349	return 0;
350}
351
352/*
353 * get_shareable_mask - Get shareable mask from shareable_bits
354 * @cache_type:		Cache type as "L2" or "L3"
355 * @shareable_mask:	Shareable mask returned as unsigned long
356 *
357 * Return: = 0 on success, < 0 on failure.
358 */
359static int get_shareable_mask(const char *cache_type, unsigned long *shareable_mask)
360{
361	char mask_path[PATH_MAX];
362
363	if (!cache_type)
364		return -1;
365
366	snprintf(mask_path, sizeof(mask_path), "%s/%s/shareable_bits",
367		 INFO_PATH, cache_type);
368
369	return get_bit_mask(mask_path, shareable_mask);
370}
371
372/*
373 * get_mask_no_shareable - Get Cache Bit Mask (CBM) without shareable bits
374 * @cache_type:		Cache type as "L2" or "L3"
375 * @mask:		The largest exclusive portion of the cache out of the
376 *			full CBM, returned as unsigned long
377 *
378 * Parts of a cache may be shared with other devices such as GPU. This function
379 * calculates the largest exclusive portion of the cache where no other devices
380 * besides CPU have access to the cache portion.
381 *
382 * Return: = 0 on success, < 0 on failure.
383 */
384int get_mask_no_shareable(const char *cache_type, unsigned long *mask)
385{
386	unsigned long full_mask, shareable_mask;
387	unsigned int start, len;
388
389	if (get_full_cbm(cache_type, &full_mask) < 0)
390		return -1;
391	if (get_shareable_mask(cache_type, &shareable_mask) < 0)
392		return -1;
393
394	len = count_contiguous_bits(full_mask & ~shareable_mask, &start);
395	if (!len)
396		return -1;
397
398	*mask = create_bit_mask(start, len);
399
400	return 0;
401}
402
403/*
404 * taskset_benchmark - Taskset PID (i.e. benchmark) to a specified cpu
405 * @bm_pid:		PID that should be binded
406 * @cpu_no:		CPU number at which the PID would be binded
407 * @old_affinity:	When not NULL, set to old CPU affinity
408 *
409 * Return: 0 on success, < 0 on error.
410 */
411int taskset_benchmark(pid_t bm_pid, int cpu_no, cpu_set_t *old_affinity)
412{
413	cpu_set_t my_set;
414
415	if (old_affinity) {
416		CPU_ZERO(old_affinity);
417		if (sched_getaffinity(bm_pid, sizeof(*old_affinity),
418				      old_affinity)) {
419			ksft_perror("Unable to read CPU affinity");
420			return -1;
421		}
422	}
423
424	CPU_ZERO(&my_set);
425	CPU_SET(cpu_no, &my_set);
426
427	if (sched_setaffinity(bm_pid, sizeof(cpu_set_t), &my_set)) {
428		ksft_perror("Unable to taskset benchmark");
429
430		return -1;
431	}
432
433	return 0;
434}
435
436/*
437 * taskset_restore - Taskset PID to the earlier CPU affinity
438 * @bm_pid:		PID that should be reset
439 * @old_affinity:	The old CPU affinity to restore
440 *
441 * Return: 0 on success, < 0 on error.
442 */
443int taskset_restore(pid_t bm_pid, cpu_set_t *old_affinity)
444{
445	if (sched_setaffinity(bm_pid, sizeof(*old_affinity), old_affinity)) {
446		ksft_perror("Unable to restore CPU affinity");
447		return -1;
448	}
449
450	return 0;
451}
452
453/*
454 * create_grp - Create a group only if one doesn't exist
455 * @grp_name:	Name of the group
456 * @grp:	Full path and name of the group
457 * @parent_grp:	Full path and name of the parent group
458 *
459 * Return: 0 on success, < 0 on error.
460 */
461static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
462{
463	int found_grp = 0;
464	struct dirent *ep;
465	DIR *dp;
466
467	/*
468	 * At this point, we are guaranteed to have resctrl FS mounted and if
469	 * length of grp_name == 0, it means, user wants to use root con_mon
470	 * grp, so do nothing
471	 */
472	if (strlen(grp_name) == 0)
473		return 0;
474
475	/* Check if requested grp exists or not */
476	dp = opendir(parent_grp);
477	if (dp) {
478		while ((ep = readdir(dp)) != NULL) {
479			if (strcmp(ep->d_name, grp_name) == 0)
480				found_grp = 1;
481		}
482		closedir(dp);
483	} else {
484		ksft_perror("Unable to open resctrl for group");
485
486		return -1;
487	}
488
489	/* Requested grp doesn't exist, hence create it */
490	if (found_grp == 0) {
491		if (mkdir(grp, 0) == -1) {
492			ksft_perror("Unable to create group");
493
494			return -1;
495		}
496	}
497
498	return 0;
499}
500
501static int write_pid_to_tasks(char *tasks, pid_t pid)
502{
503	FILE *fp;
504
505	fp = fopen(tasks, "w");
506	if (!fp) {
507		ksft_perror("Failed to open tasks file");
508
509		return -1;
510	}
511	if (fprintf(fp, "%d\n", pid) < 0) {
512		ksft_print_msg("Failed to write pid to tasks file\n");
513		fclose(fp);
514
515		return -1;
516	}
517	fclose(fp);
518
519	return 0;
520}
521
522/*
523 * write_bm_pid_to_resctrl - Write a PID (i.e. benchmark) to resctrl FS
524 * @bm_pid:		PID that should be written
525 * @ctrlgrp:		Name of the control monitor group (con_mon grp)
526 * @mongrp:		Name of the monitor group (mon grp)
527 * @resctrl_val:	Resctrl feature (Eg: mbm, mba.. etc)
528 *
529 * If a con_mon grp is requested, create it and write pid to it, otherwise
530 * write pid to root con_mon grp.
531 * If a mon grp is requested, create it and write pid to it, otherwise
532 * pid is not written, this means that pid is in con_mon grp and hence
533 * should consult con_mon grp's mon_data directory for results.
534 *
535 * Return: 0 on success, < 0 on error.
536 */
537int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
538			    char *resctrl_val)
539{
540	char controlgroup[128], monitorgroup[512], monitorgroup_p[256];
541	char tasks[1024];
542	int ret = 0;
543
544	if (strlen(ctrlgrp))
545		sprintf(controlgroup, "%s/%s", RESCTRL_PATH, ctrlgrp);
546	else
547		sprintf(controlgroup, "%s", RESCTRL_PATH);
548
549	/* Create control and monitoring group and write pid into it */
550	ret = create_grp(ctrlgrp, controlgroup, RESCTRL_PATH);
551	if (ret)
552		goto out;
553	sprintf(tasks, "%s/tasks", controlgroup);
554	ret = write_pid_to_tasks(tasks, bm_pid);
555	if (ret)
556		goto out;
557
558	/* Create mon grp and write pid into it for "mbm" and "cmt" test */
559	if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)) ||
560	    !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) {
561		if (strlen(mongrp)) {
562			sprintf(monitorgroup_p, "%s/mon_groups", controlgroup);
563			sprintf(monitorgroup, "%s/%s", monitorgroup_p, mongrp);
564			ret = create_grp(mongrp, monitorgroup, monitorgroup_p);
565			if (ret)
566				goto out;
567
568			sprintf(tasks, "%s/mon_groups/%s/tasks",
569				controlgroup, mongrp);
570			ret = write_pid_to_tasks(tasks, bm_pid);
571			if (ret)
572				goto out;
573		}
574	}
575
576out:
577	ksft_print_msg("Writing benchmark parameters to resctrl FS\n");
578	if (ret)
579		ksft_print_msg("Failed writing to resctrlfs\n");
580
581	return ret;
582}
583
584/*
585 * write_schemata - Update schemata of a con_mon grp
586 * @ctrlgrp:		Name of the con_mon grp
587 * @schemata:		Schemata that should be updated to
588 * @cpu_no:		CPU number that the benchmark PID is binded to
589 * @resource:		Resctrl resource (Eg: MB, L3, L2, etc.)
590 *
591 * Update schemata of a con_mon grp *only* if requested resctrl resource is
592 * allocation type
593 *
594 * Return: 0 on success, < 0 on error.
595 */
596int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, const char *resource)
597{
598	char controlgroup[1024], reason[128], schema[1024] = {};
599	int domain_id, fd, schema_len, ret = 0;
600
601	if (!schemata) {
602		ksft_print_msg("Skipping empty schemata update\n");
603
604		return -1;
605	}
606
607	if (get_domain_id(resource, cpu_no, &domain_id) < 0) {
608		sprintf(reason, "Failed to get domain ID");
609		ret = -1;
610
611		goto out;
612	}
613
614	if (strlen(ctrlgrp) != 0)
615		sprintf(controlgroup, "%s/%s/schemata", RESCTRL_PATH, ctrlgrp);
616	else
617		sprintf(controlgroup, "%s/schemata", RESCTRL_PATH);
618
619	schema_len = snprintf(schema, sizeof(schema), "%s:%d=%s\n",
620			      resource, domain_id, schemata);
621	if (schema_len < 0 || schema_len >= sizeof(schema)) {
622		snprintf(reason, sizeof(reason),
623			 "snprintf() failed with return value : %d", schema_len);
624		ret = -1;
625		goto out;
626	}
627
628	fd = open(controlgroup, O_WRONLY);
629	if (fd < 0) {
630		snprintf(reason, sizeof(reason),
631			 "open() failed : %s", strerror(errno));
632		ret = -1;
633
634		goto err_schema_not_empty;
635	}
636	if (write(fd, schema, schema_len) < 0) {
637		snprintf(reason, sizeof(reason),
638			 "write() failed : %s", strerror(errno));
639		close(fd);
640		ret = -1;
641
642		goto err_schema_not_empty;
643	}
644	close(fd);
645
646err_schema_not_empty:
647	schema[schema_len - 1] = 0;
648out:
649	ksft_print_msg("Write schema \"%s\" to resctrl FS%s%s\n",
650		       schema, ret ? " # " : "",
651		       ret ? reason : "");
652
653	return ret;
654}
655
656bool check_resctrlfs_support(void)
657{
658	FILE *inf = fopen("/proc/filesystems", "r");
659	DIR *dp;
660	char *res;
661	bool ret = false;
662
663	if (!inf)
664		return false;
665
666	res = fgrep(inf, "nodev\tresctrl\n");
667
668	if (res) {
669		ret = true;
670		free(res);
671	}
672
673	fclose(inf);
674
675	ksft_print_msg("%s Check kernel supports resctrl filesystem\n",
676		       ret ? "Pass:" : "Fail:");
677
678	if (!ret)
679		return ret;
680
681	dp = opendir(RESCTRL_PATH);
682	ksft_print_msg("%s Check resctrl mountpoint \"%s\" exists\n",
683		       dp ? "Pass:" : "Fail:", RESCTRL_PATH);
684	if (dp)
685		closedir(dp);
686
687	ksft_print_msg("resctrl filesystem %s mounted\n",
688		       find_resctrl_mount(NULL) ? "not" : "is");
689
690	return ret;
691}
692
693char *fgrep(FILE *inf, const char *str)
694{
695	char line[256];
696	int slen = strlen(str);
697
698	while (!feof(inf)) {
699		if (!fgets(line, 256, inf))
700			break;
701		if (strncmp(line, str, slen))
702			continue;
703
704		return strdup(line);
705	}
706
707	return NULL;
708}
709
710/*
711 * resctrl_resource_exists - Check if a resource is supported.
712 * @resource:	Resctrl resource (e.g., MB, L3, L2, L3_MON, etc.)
713 *
714 * Return: True if the resource is supported, else false. False is
715 *         also returned if resctrl FS is not mounted.
716 */
717bool resctrl_resource_exists(const char *resource)
718{
719	char res_path[PATH_MAX];
720	struct stat statbuf;
721	int ret;
722
723	if (!resource)
724		return false;
725
726	ret = find_resctrl_mount(NULL);
727	if (ret)
728		return false;
729
730	snprintf(res_path, sizeof(res_path), "%s/%s", INFO_PATH, resource);
731
732	if (stat(res_path, &statbuf))
733		return false;
734
735	return true;
736}
737
738/*
739 * resctrl_mon_feature_exists - Check if requested monitoring feature is valid.
740 * @resource:	Resource that uses the mon_features file. Currently only L3_MON
741 *		is valid.
742 * @feature:	Required monitor feature (in mon_features file).
743 *
744 * Return: True if the feature is supported, else false.
745 */
746bool resctrl_mon_feature_exists(const char *resource, const char *feature)
747{
748	char res_path[PATH_MAX];
749	char *res;
750	FILE *inf;
751
752	if (!feature || !resource)
753		return false;
754
755	snprintf(res_path, sizeof(res_path), "%s/%s/mon_features", INFO_PATH, resource);
756	inf = fopen(res_path, "r");
757	if (!inf)
758		return false;
759
760	res = fgrep(inf, feature);
761	free(res);
762	fclose(inf);
763
764	return !!res;
765}
766
767/*
768 * resource_info_file_exists - Check if a file is present inside
769 * /sys/fs/resctrl/info/@resource.
770 * @resource:	Required resource (Eg: MB, L3, L2, etc.)
771 * @file:	Required file.
772 *
773 * Return: True if the /sys/fs/resctrl/info/@resource/@file exists, else false.
774 */
775bool resource_info_file_exists(const char *resource, const char *file)
776{
777	char res_path[PATH_MAX];
778	struct stat statbuf;
779
780	if (!file || !resource)
781		return false;
782
783	snprintf(res_path, sizeof(res_path), "%s/%s/%s", INFO_PATH, resource,
784		 file);
785
786	if (stat(res_path, &statbuf))
787		return false;
788
789	return true;
790}
791
792bool test_resource_feature_check(const struct resctrl_test *test)
793{
794	return resctrl_resource_exists(test->resource);
795}
796
797int filter_dmesg(void)
798{
799	char line[1024];
800	FILE *fp;
801	int pipefds[2];
802	pid_t pid;
803	int ret;
804
805	ret = pipe(pipefds);
806	if (ret) {
807		ksft_perror("pipe");
808		return ret;
809	}
810	fflush(stdout);
811	pid = fork();
812	if (pid == 0) {
813		close(pipefds[0]);
814		dup2(pipefds[1], STDOUT_FILENO);
815		execlp("dmesg", "dmesg", NULL);
816		ksft_perror("Executing dmesg");
817		exit(1);
818	}
819	close(pipefds[1]);
820	fp = fdopen(pipefds[0], "r");
821	if (!fp) {
822		ksft_perror("fdopen(pipe)");
823		kill(pid, SIGTERM);
824
825		return -1;
826	}
827
828	while (fgets(line, 1024, fp)) {
829		if (strstr(line, "intel_rdt:"))
830			ksft_print_msg("dmesg: %s", line);
831		if (strstr(line, "resctrl:"))
832			ksft_print_msg("dmesg: %s", line);
833	}
834	fclose(fp);
835	waitpid(pid, NULL, 0);
836
837	return 0;
838}
839
840int validate_bw_report_request(char *bw_report)
841{
842	if (strcmp(bw_report, "reads") == 0)
843		return 0;
844	if (strcmp(bw_report, "writes") == 0)
845		return 0;
846	if (strcmp(bw_report, "nt-writes") == 0) {
847		strcpy(bw_report, "writes");
848		return 0;
849	}
850	if (strcmp(bw_report, "total") == 0)
851		return 0;
852
853	fprintf(stderr, "Requested iMC B/W report type unavailable\n");
854
855	return -1;
856}
857
858int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
859		    int group_fd, unsigned long flags)
860{
861	int ret;
862
863	ret = syscall(__NR_perf_event_open, hw_event, pid, cpu,
864		      group_fd, flags);
865	return ret;
866}
867
868unsigned int count_bits(unsigned long n)
869{
870	unsigned int count = 0;
871
872	while (n) {
873		count += n & 1;
874		n >>= 1;
875	}
876
877	return count;
878}
879