1 /**
2 * Copyright (C) ARM Limited 2013-2014. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
9 #include "KMod.h"
11 #include <sys/types.h>
12 #include <dirent.h>
13 #include <unistd.h>
15 #include "ConfigurationXML.h"
16 #include "Counter.h"
17 #include "DriverSource.h"
18 #include "Logging.h"
20 // Claim all the counters in /dev/gator/events
21 bool KMod::claimCounter(const Counter &counter) const {
22 char text[128];
23 snprintf(text, sizeof(text), "/dev/gator/events/%s", counter.getType());
24 return access(text, F_OK) == 0;
25 }
27 void KMod::resetCounters() {
28 char base[128];
29 char text[128];
31 // Initialize all perf counters in the driver, i.e. set enabled to zero
32 struct dirent *ent;
33 DIR* dir = opendir("/dev/gator/events");
34 if (dir) {
35 while ((ent = readdir(dir)) != NULL) {
36 // skip hidden files, current dir, and parent dir
37 if (ent->d_name[0] == '.')
38 continue;
39 snprintf(base, sizeof(base), "/dev/gator/events/%s", ent->d_name);
40 snprintf(text, sizeof(text), "%s/enabled", base);
41 DriverSource::writeDriver(text, 0);
42 snprintf(text, sizeof(text), "%s/count", base);
43 DriverSource::writeDriver(text, 0);
44 }
45 closedir(dir);
46 }
47 }
49 void KMod::setupCounter(Counter &counter) {
50 char base[128];
51 char text[128];
52 snprintf(base, sizeof(base), "/dev/gator/events/%s", counter.getType());
54 snprintf(text, sizeof(text), "%s/enabled", base);
55 int enabled = true;
56 if (DriverSource::writeReadDriver(text, &enabled) || !enabled) {
57 counter.setEnabled(false);
58 return;
59 }
61 snprintf(text, sizeof(text), "%s/key", base);
62 int key = 0;
63 DriverSource::readIntDriver(text, &key);
64 counter.setKey(key);
66 snprintf(text, sizeof(text), "%s/event", base);
67 DriverSource::writeDriver(text, counter.getEvent());
68 snprintf(text, sizeof(text), "%s/count", base);
69 if (access(text, F_OK) == 0) {
70 int count = counter.getCount();
71 if (DriverSource::writeReadDriver(text, &count) && counter.getCount() > 0) {
72 logg->logError(__FILE__, __LINE__, "Cannot enable EBS for %s:%i with a count of %d\n", counter.getType(), counter.getEvent(), counter.getCount());
73 handleException();
74 }
75 counter.setCount(count);
76 } else if (counter.getCount() > 0) {
77 ConfigurationXML::remove();
78 logg->logError(__FILE__, __LINE__, "Event Based Sampling is only supported with kernel versions 3.0.0 and higher with CONFIG_PERF_EVENTS=y, and CONFIG_HW_PERF_EVENTS=y. The invalid configuration.xml has been removed.\n");
79 handleException();
80 }
81 }
83 int KMod::writeCounters(mxml_node_t *root) const {
84 struct dirent *ent;
85 mxml_node_t *counter;
87 // counters.xml is simply a file listing of /dev/gator/events
88 DIR* dir = opendir("/dev/gator/events");
89 if (dir == NULL) {
90 return 0;
91 }
93 int count = 0;
94 while ((ent = readdir(dir)) != NULL) {
95 // skip hidden files, current dir, and parent dir
96 if (ent->d_name[0] == '.')
97 continue;
98 counter = mxmlNewElement(root, "counter");
99 mxmlElementSetAttr(counter, "name", ent->d_name);
100 ++count;
101 }
102 closedir(dir);
104 return count;
105 }