1 files changed, 195 insertions, 0 deletions
diff --git a/tools/gator/daemon/FtraceDriver.cpp b/tools/gator/daemon/FtraceDriver.cpp
new file mode 100644
index 00000000000..98bd0a5d9ee
--- /dev/null
+++ b/tools/gator/daemon/FtraceDriver.cpp
@@ -0,0 +1,195 @@
+/**
+ * Copyright (C) ARM Limited 2014-2015. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "FtraceDriver.h"
+
+#include <regex.h>
+#include <unistd.h>
+
+#include "DriverSource.h"
+#include "Logging.h"
+#include "Setup.h"
+
+class FtraceCounter : public DriverCounter {
+public:
+	FtraceCounter(DriverCounter *next, char *name, const char *regex, const char *enable);
+	~FtraceCounter();
+
+	void prepare();
+	int read(const char *const line, int64_t *values);
+	void stop();
+
+private:
+	regex_t mReg;
+	char *const mEnable;
+	int mWasEnabled;
+
+	// Intentionally unimplemented
+	FtraceCounter(const FtraceCounter &);
+	FtraceCounter &operator=(const FtraceCounter &);
+};
+
+FtraceCounter::FtraceCounter(DriverCounter *next, char *name, const char *regex, const char *enable) : DriverCounter(next, name), mEnable(enable == NULL ? NULL : strdup(enable)) {
+	int result = regcomp(&mReg, regex, REG_EXTENDED);
+	if (result != 0) {
+		char buf[128];
+		regerror(result, &mReg, buf, sizeof(buf));
+		logg->logError("Invalid regex '%s': %s", regex, buf);
+		handleException();
+	}
+}
+
+FtraceCounter::~FtraceCounter() {
+	regfree(&mReg);
+	if (mEnable != NULL) {
+		free(mEnable);
+	}
+}
+
+void FtraceCounter::prepare() {
+	if (mEnable == NULL) {
+		return;
+	}
+
+	char buf[1<<10];
+	snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%s/enable", mEnable);
+	if ((DriverSource::readIntDriver(buf, &mWasEnabled) != 0) ||
+			(DriverSource::writeDriver(buf, 1) != 0)) {
+		logg->logError("Unable to read or write to %s", buf);
+		handleException();
+	}
+}
+
+int FtraceCounter::read(const char *const line, int64_t *values) {
+	regmatch_t match[2];
+	int result = regexec(&mReg, line, 2, match, 0);
+	if (result != 0) {
+		// No match
+		return 0;
+	}
+
+	int64_t value;
+	if (match[1].rm_so < 0) {
+		value = 1;
+	} else {
+		errno = 0;
+		value = strtoll(line + match[1].rm_so, NULL, 0);
+		if (errno != 0) {
+			logg->logError("Parsing %s failed: %s", getName(), strerror(errno));
+			handleException();
+		}
+	}
+
+	values[0] = getKey();
+	values[1] = value;
+
+	return 1;
+}
+
+void FtraceCounter::stop() {
+	if (mEnable == NULL) {
+		return;
+	}
+
+	char buf[1<<10];
+	snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%s/enable", mEnable);
+	DriverSource::writeDriver(buf, mWasEnabled);
+}
+
+FtraceDriver::FtraceDriver() : mValues(NULL) {
+}
+
+FtraceDriver::~FtraceDriver() {
+	delete [] mValues;
+}
+
+void FtraceDriver::readEvents(mxml_node_t *const xml) {
+	// Check the kernel version
+	int release[3];
+	if (!getLinuxVersion(release)) {
+		logg->logError("getLinuxVersion failed");
+		handleException();
+	}
+
+	// The perf clock was added in 3.10
+	if (KERNEL_VERSION(release[0], release[1], release[2]) < KERNEL_VERSION(3, 10, 0)) {
+		logg->logMessage("Unsupported kernel version, to use ftrace please upgrade to Linux 3.10 or later");
+		return;
+	}
+
+	mxml_node_t *node = xml;
+	int count = 0;
+	while (true) {
+		node = mxmlFindElement(node, xml, "event", NULL, NULL, MXML_DESCEND);
+		if (node == NULL) {
+			break;
+		}
+		const char *counter = mxmlElementGetAttr(node, "counter");
+		if (counter == NULL) {
+			continue;
+		}
+
+		if (strncmp(counter, "ftrace_", 7) != 0) {
+			continue;
+		}
+
+		const char *regex = mxmlElementGetAttr(node, "regex");
+		if (regex == NULL) {
+			logg->logError("The regex counter %s is missing the required regex attribute", counter);
+			handleException();
+		}
+		bool addCounter = true;
+		const char *enable = mxmlElementGetAttr(node, "enable");
+		if (enable != NULL) {
+			char buf[1<<10];
+			snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%s/enable", enable);
+			if (access(buf, W_OK) != 0) {
+				logg->logMessage("Disabling counter %s, %s not found", counter, buf);
+				addCounter = false;
+			}
+		}
+		if (addCounter) {
+			setCounters(new FtraceCounter(getCounters(), strdup(counter), regex, enable));
+			++count;
+		}
+	}
+
+	mValues = new int64_t[2*count];
+}
+
+void FtraceDriver::prepare() {
+	for (FtraceCounter *counter = static_cast<FtraceCounter *>(getCounters()); counter != NULL; counter = static_cast<FtraceCounter *>(counter->getNext())) {
+		if (!counter->isEnabled()) {
+			continue;
+		}
+		counter->prepare();
+	}
+}
+
+int FtraceDriver::read(const char *line, int64_t **buf) {
+	int count = 0;
+
+	for (FtraceCounter *counter = static_cast<FtraceCounter *>(getCounters()); counter != NULL; counter = static_cast<FtraceCounter *>(counter->getNext())) {
+		if (!counter->isEnabled()) {
+			continue;
+		}
+		count += counter->read(line, mValues + 2*count);
+	}
+
+	*buf = mValues;
+	return count;
+}
+
+void FtraceDriver::stop() {
+	for (FtraceCounter *counter = static_cast<FtraceCounter *>(getCounters()); counter != NULL; counter = static_cast<FtraceCounter *>(counter->getNext())) {
+		if (!counter->isEnabled()) {
+			continue;
+		}
+		counter->stop();
+	}
+}