+++ /dev/null
-/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
- *
- * lttng-clock.c
- *
- * Copyright (C) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- */
-
-#include <linux/module.h>
-#include <linux/kmod.h>
-#include <linux/mutex.h>
-
-#include <wrapper/trace-clock.h>
-#include <lttng/events.h>
-#include <lttng/tracer.h>
-
-struct lttng_trace_clock *lttng_trace_clock;
-EXPORT_SYMBOL_GPL(lttng_trace_clock);
-
-static DEFINE_MUTEX(clock_mutex);
-static struct module *lttng_trace_clock_mod; /* plugin */
-static int clock_used; /* refcount */
-
-int lttng_clock_register_plugin(struct lttng_trace_clock *ltc,
- struct module *mod)
-{
- int ret = 0;
-
- mutex_lock(&clock_mutex);
- if (clock_used) {
- ret = -EBUSY;
- goto end;
- }
- if (lttng_trace_clock_mod) {
- ret = -EEXIST;
- goto end;
- }
- /* set clock */
- WRITE_ONCE(lttng_trace_clock, ltc);
- lttng_trace_clock_mod = mod;
-end:
- mutex_unlock(&clock_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(lttng_clock_register_plugin);
-
-void lttng_clock_unregister_plugin(struct lttng_trace_clock *ltc,
- struct module *mod)
-{
- mutex_lock(&clock_mutex);
- WARN_ON_ONCE(clock_used);
- if (!lttng_trace_clock_mod) {
- goto end;
- }
- WARN_ON_ONCE(lttng_trace_clock_mod != mod);
-
- WRITE_ONCE(lttng_trace_clock, NULL);
- lttng_trace_clock_mod = NULL;
-end:
- mutex_unlock(&clock_mutex);
-}
-EXPORT_SYMBOL_GPL(lttng_clock_unregister_plugin);
-
-void lttng_clock_ref(void)
-{
- mutex_lock(&clock_mutex);
- clock_used++;
- if (lttng_trace_clock_mod) {
- int ret;
-
- ret = try_module_get(lttng_trace_clock_mod);
- if (!ret) {
- printk(KERN_ERR "LTTng-clock cannot get clock plugin module\n");
- WRITE_ONCE(lttng_trace_clock, NULL);
- lttng_trace_clock_mod = NULL;
- }
- }
- mutex_unlock(&clock_mutex);
-}
-EXPORT_SYMBOL_GPL(lttng_clock_ref);
-
-void lttng_clock_unref(void)
-{
- mutex_lock(&clock_mutex);
- clock_used--;
- if (lttng_trace_clock_mod)
- module_put(lttng_trace_clock_mod);
- mutex_unlock(&clock_mutex);
-}
-EXPORT_SYMBOL_GPL(lttng_clock_unref);
-
-MODULE_LICENSE("GPL and additional rights");
-MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
-MODULE_DESCRIPTION("LTTng Clock");
-MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
- __stringify(LTTNG_MODULES_MINOR_VERSION) "."
- __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
- LTTNG_MODULES_EXTRAVERSION);