Commit | Line | Data |
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1c8284eb MD |
1 | /* |
2 | * LTT core in-kernel infrastructure. | |
3 | * | |
4 | * Copyright 2006 - Mathieu Desnoyers mathieu.desnoyers@polymtl.ca | |
5 | * | |
6 | * Dual LGPL v2.1/GPL v2 license. | |
7 | */ | |
8 | ||
9 | #include <linux/percpu.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/debugfs.h> | |
12 | #include <linux/kref.h> | |
13 | #include <linux/cpu.h> | |
14 | ||
15 | #include "ltt-tracer-core.h" | |
16 | ||
17 | /* Traces structures */ | |
18 | struct ltt_traces ltt_traces = { | |
19 | .setup_head = LIST_HEAD_INIT(ltt_traces.setup_head), | |
20 | .head = LIST_HEAD_INIT(ltt_traces.head), | |
21 | }; | |
22 | EXPORT_SYMBOL(ltt_traces); | |
23 | ||
24 | /* Traces list writer locking */ | |
25 | static DEFINE_MUTEX(ltt_traces_mutex); | |
26 | ||
27 | /* root dentry mutex */ | |
28 | static DEFINE_MUTEX(ltt_root_mutex); | |
29 | /* dentry of ltt's root dir */ | |
30 | static struct dentry *ltt_root_dentry; | |
31 | static struct kref ltt_root_kref = { | |
32 | .refcount = ATOMIC_INIT(0), | |
33 | }; | |
34 | ||
35 | static void ltt_root_release(struct kref *ref) | |
36 | { | |
37 | debugfs_remove(ltt_root_dentry); | |
38 | ltt_root_dentry = NULL; | |
39 | } | |
40 | ||
41 | void put_ltt_root(void) | |
42 | { | |
43 | mutex_lock(<t_root_mutex); | |
44 | if (ltt_root_dentry) | |
45 | kref_put(<t_root_kref, ltt_root_release); | |
46 | mutex_unlock(<t_root_mutex); | |
47 | } | |
48 | EXPORT_SYMBOL_GPL(put_ltt_root); | |
49 | ||
50 | struct dentry *get_ltt_root(void) | |
51 | { | |
52 | mutex_lock(<t_root_mutex); | |
53 | if (!ltt_root_dentry) { | |
54 | ltt_root_dentry = debugfs_create_dir(LTT_ROOT, NULL); | |
55 | if (!ltt_root_dentry) { | |
56 | printk(KERN_ERR "LTT : create ltt root dir failed\n"); | |
57 | goto out; | |
58 | } | |
59 | kref_init(<t_root_kref); | |
60 | goto out; | |
61 | } | |
62 | kref_get(<t_root_kref); | |
63 | out: | |
64 | mutex_unlock(<t_root_mutex); | |
65 | return ltt_root_dentry; | |
66 | } | |
67 | EXPORT_SYMBOL_GPL(get_ltt_root); | |
68 | ||
69 | /* | |
70 | * ltt_lock_traces/ltt_unlock_traces also disables cpu hotplug. | |
71 | */ | |
72 | void ltt_lock_traces(void) | |
73 | { | |
74 | mutex_lock(<t_traces_mutex); | |
75 | get_online_cpus(); | |
76 | } | |
77 | EXPORT_SYMBOL_GPL(ltt_lock_traces); | |
78 | ||
79 | void ltt_unlock_traces(void) | |
80 | { | |
81 | put_online_cpus(); | |
82 | mutex_unlock(<t_traces_mutex); | |
83 | } | |
84 | EXPORT_SYMBOL_GPL(ltt_unlock_traces); | |
85 | ||
86 | DEFINE_PER_CPU(unsigned int, ltt_nesting); | |
87 | EXPORT_PER_CPU_SYMBOL(ltt_nesting); | |
88 | ||
89 | int ltt_run_filter_default(void *trace, uint16_t eID) | |
90 | { | |
91 | return 1; | |
92 | } | |
93 | ||
94 | /* This function pointer is protected by a trace activation check */ | |
95 | ltt_run_filter_functor ltt_run_filter = ltt_run_filter_default; | |
96 | EXPORT_SYMBOL_GPL(ltt_run_filter); | |
97 | ||
98 | void ltt_filter_register(ltt_run_filter_functor func) | |
99 | { | |
100 | ltt_run_filter = func; | |
101 | } | |
102 | EXPORT_SYMBOL_GPL(ltt_filter_register); | |
103 | ||
104 | void ltt_filter_unregister(void) | |
105 | { | |
106 | ltt_run_filter = ltt_run_filter_default; | |
107 | } | |
108 | EXPORT_SYMBOL_GPL(ltt_filter_unregister); | |
2e6246b4 MD |
109 | |
110 | MODULE_LICENSE("GPL and additional rights"); | |
111 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
112 | MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Tracer Core"); |