Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm
[linux-2.6] / drivers / oprofile / oprofile_files.c
1 /**
2  * @file oprofile_files.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/fs.h>
11 #include <linux/oprofile.h>
12
13 #include "event_buffer.h"
14 #include "oprofile_stats.h"
15 #include "oprof.h"
16
17 #define BUFFER_SIZE_DEFAULT             131072
18 #define CPU_BUFFER_SIZE_DEFAULT         8192
19 #define BUFFER_WATERSHED_DEFAULT        32768   /* FIXME: tune */
20
21 unsigned long oprofile_buffer_size;
22 unsigned long oprofile_cpu_buffer_size;
23 unsigned long oprofile_buffer_watershed;
24
25 static ssize_t depth_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
26 {
27         return oprofilefs_ulong_to_user(oprofile_backtrace_depth, buf, count,
28                                         offset);
29 }
30
31
32 static ssize_t depth_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
33 {
34         unsigned long val;
35         int retval;
36
37         if (*offset)
38                 return -EINVAL;
39
40         retval = oprofilefs_ulong_from_user(&val, buf, count);
41         if (retval)
42                 return retval;
43
44         retval = oprofile_set_backtrace(val);
45
46         if (retval)
47                 return retval;
48         return count;
49 }
50
51
52 static const struct file_operations depth_fops = {
53         .read           = depth_read,
54         .write          = depth_write
55 };
56
57
58 static ssize_t pointer_size_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
59 {
60         return oprofilefs_ulong_to_user(sizeof(void *), buf, count, offset);
61 }
62
63
64 static const struct file_operations pointer_size_fops = {
65         .read           = pointer_size_read,
66 };
67
68
69 static ssize_t cpu_type_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
70 {
71         return oprofilefs_str_to_user(oprofile_ops.cpu_type, buf, count, offset);
72 }
73
74
75 static const struct file_operations cpu_type_fops = {
76         .read           = cpu_type_read,
77 };
78
79
80 static ssize_t enable_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
81 {
82         return oprofilefs_ulong_to_user(oprofile_started, buf, count, offset);
83 }
84
85
86 static ssize_t enable_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
87 {
88         unsigned long val;
89         int retval;
90
91         if (*offset)
92                 return -EINVAL;
93
94         retval = oprofilefs_ulong_from_user(&val, buf, count);
95         if (retval)
96                 return retval;
97
98         if (val)
99                 retval = oprofile_start();
100         else
101                 oprofile_stop();
102
103         if (retval)
104                 return retval;
105         return count;
106 }
107
108
109 static const struct file_operations enable_fops = {
110         .read           = enable_read,
111         .write          = enable_write,
112 };
113
114
115 static ssize_t dump_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
116 {
117         wake_up_buffer_waiter();
118         return count;
119 }
120
121
122 static const struct file_operations dump_fops = {
123         .write          = dump_write,
124 };
125
126 void oprofile_create_files(struct super_block *sb, struct dentry *root)
127 {
128         /* reinitialize default values */
129         oprofile_buffer_size =          BUFFER_SIZE_DEFAULT;
130         oprofile_cpu_buffer_size =      CPU_BUFFER_SIZE_DEFAULT;
131         oprofile_buffer_watershed =     BUFFER_WATERSHED_DEFAULT;
132
133         oprofilefs_create_file(sb, root, "enable", &enable_fops);
134         oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
135         oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
136         oprofilefs_create_ulong(sb, root, "buffer_size", &oprofile_buffer_size);
137         oprofilefs_create_ulong(sb, root, "buffer_watershed", &oprofile_buffer_watershed);
138         oprofilefs_create_ulong(sb, root, "cpu_buffer_size", &oprofile_cpu_buffer_size);
139         oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops);
140         oprofilefs_create_file(sb, root, "backtrace_depth", &depth_fops);
141         oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops);
142         oprofile_create_stats_files(sb, root);
143         if (oprofile_ops.create_files)
144                 oprofile_ops.create_files(sb, root);
145 }