oprofile: fixing whitespaces in drivers/oprofile/*
[linux-2.6.git] / drivers / oprofile / oprof.c
1 /**
2  * @file oprof.c
3  *
4  * @remark Copyright 2002 OProfile authors
5  * @remark Read the file COPYING
6  *
7  * @author John Levon <levon@movementarian.org>
8  */
9
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/oprofile.h>
14 #include <linux/moduleparam.h>
15 #include <asm/mutex.h>
16
17 #include "oprof.h"
18 #include "event_buffer.h"
19 #include "cpu_buffer.h"
20 #include "buffer_sync.h"
21 #include "oprofile_stats.h"
22
23 struct oprofile_operations oprofile_ops;
24
25 unsigned long oprofile_started;
26 unsigned long backtrace_depth;
27 static unsigned long is_setup;
28 static DEFINE_MUTEX(start_mutex);
29
30 /* timer
31    0 - use performance monitoring hardware if available
32    1 - use the timer int mechanism regardless
33  */
34 static int timer = 0;
35
36 int oprofile_setup(void)
37 {
38         int err;
39
40         mutex_lock(&start_mutex);
41
42         if ((err = alloc_cpu_buffers()))
43                 goto out;
44
45         if ((err = alloc_event_buffer()))
46                 goto out1;
47
48         if (oprofile_ops.setup && (err = oprofile_ops.setup()))
49                 goto out2;
50
51         /* Note even though this starts part of the
52          * profiling overhead, it's necessary to prevent
53          * us missing task deaths and eventually oopsing
54          * when trying to process the event buffer.
55          */
56         if (oprofile_ops.sync_start) {
57                 int sync_ret = oprofile_ops.sync_start();
58                 switch (sync_ret) {
59                 case 0:
60                         goto post_sync;
61                 case 1:
62                         goto do_generic;
63                 case -1:
64                         goto out3;
65                 default:
66                         goto out3;
67                 }
68         }
69 do_generic:
70         if ((err = sync_start()))
71                 goto out3;
72
73 post_sync:
74         is_setup = 1;
75         mutex_unlock(&start_mutex);
76         return 0;
77
78 out3:
79         if (oprofile_ops.shutdown)
80                 oprofile_ops.shutdown();
81 out2:
82         free_event_buffer();
83 out1:
84         free_cpu_buffers();
85 out:
86         mutex_unlock(&start_mutex);
87         return err;
88 }
89
90
91 /* Actually start profiling (echo 1>/dev/oprofile/enable) */
92 int oprofile_start(void)
93 {
94         int err = -EINVAL;
95
96         mutex_lock(&start_mutex);
97
98         if (!is_setup)
99                 goto out;
100
101         err = 0;
102
103         if (oprofile_started)
104                 goto out;
105
106         oprofile_reset_stats();
107
108         if ((err = oprofile_ops.start()))
109                 goto out;
110
111         oprofile_started = 1;
112 out:
113         mutex_unlock(&start_mutex);
114         return err;
115 }
116
117
118 /* echo 0>/dev/oprofile/enable */
119 void oprofile_stop(void)
120 {
121         mutex_lock(&start_mutex);
122         if (!oprofile_started)
123                 goto out;
124         oprofile_ops.stop();
125         oprofile_started = 0;
126         /* wake up the daemon to read what remains */
127         wake_up_buffer_waiter();
128 out:
129         mutex_unlock(&start_mutex);
130 }
131
132
133 void oprofile_shutdown(void)
134 {
135         mutex_lock(&start_mutex);
136         if (oprofile_ops.sync_stop) {
137                 int sync_ret = oprofile_ops.sync_stop();
138                 switch (sync_ret) {
139                 case 0:
140                         goto post_sync;
141                 case 1:
142                         goto do_generic;
143                 default:
144                         goto post_sync;
145                 }
146         }
147 do_generic:
148         sync_stop();
149 post_sync:
150         if (oprofile_ops.shutdown)
151                 oprofile_ops.shutdown();
152         is_setup = 0;
153         free_event_buffer();
154         free_cpu_buffers();
155         mutex_unlock(&start_mutex);
156 }
157
158
159 int oprofile_set_backtrace(unsigned long val)
160 {
161         int err = 0;
162
163         mutex_lock(&start_mutex);
164
165         if (oprofile_started) {
166                 err = -EBUSY;
167                 goto out;
168         }
169
170         if (!oprofile_ops.backtrace) {
171                 err = -EINVAL;
172                 goto out;
173         }
174
175         backtrace_depth = val;
176
177 out:
178         mutex_unlock(&start_mutex);
179         return err;
180 }
181
182 static int __init oprofile_init(void)
183 {
184         int err;
185
186         err = oprofile_arch_init(&oprofile_ops);
187
188         if (err < 0 || timer) {
189                 printk(KERN_INFO "oprofile: using timer interrupt.\n");
190                 oprofile_timer_init(&oprofile_ops);
191         }
192
193         err = oprofilefs_register();
194         if (err)
195                 oprofile_arch_exit();
196
197         return err;
198 }
199
200
201 static void __exit oprofile_exit(void)
202 {
203         oprofilefs_unregister();
204         oprofile_arch_exit();
205 }
206
207
208 module_init(oprofile_init);
209 module_exit(oprofile_exit);
210
211 module_param_named(timer, timer, int, 0644);
212 MODULE_PARM_DESC(timer, "force use of timer interrupt");
213
214 MODULE_LICENSE("GPL");
215 MODULE_AUTHOR("John Levon <levon@movementarian.org>");
216 MODULE_DESCRIPTION("OProfile system profiler");