Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
[linux-2.6.git] / 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 #include <linux/jiffies.h>
13
14 #include "event_buffer.h"
15 #include "oprofile_stats.h"
16 #include "oprof.h"
17
18 #define BUFFER_SIZE_DEFAULT             131072
19 #define CPU_BUFFER_SIZE_DEFAULT         8192
20 #define BUFFER_WATERSHED_DEFAULT        32768   /* FIXME: tune */
21 #define TIME_SLICE_DEFAULT              1
22
23 unsigned long oprofile_buffer_size;
24 unsigned long oprofile_cpu_buffer_size;
25 unsigned long oprofile_buffer_watershed;
26 unsigned long oprofile_time_slice;
27
28 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
29
30 static ssize_t timeout_read(struct file *file, char __user *buf,
31                 size_t count, loff_t *offset)
32 {
33         return oprofilefs_ulong_to_user(jiffies_to_msecs(oprofile_time_slice),
34                                         buf, count, offset);
35 }
36
37
38 static ssize_t timeout_write(struct file *file, char const __user *buf,
39                 size_t count, loff_t *offset)
40 {
41         unsigned long val;
42         int retval;
43
44         if (*offset)
45                 return -EINVAL;
46
47         retval = oprofilefs_ulong_from_user(&val, buf, count);
48         if (retval)
49                 return retval;
50
51         retval = oprofile_set_timeout(val);
52
53         if (retval)
54                 return retval;
55         return count;
56 }
57
58
59 static const struct file_operations timeout_fops = {
60         .read           = timeout_read,
61         .write          = timeout_write,
62         .llseek         = default_llseek,
63 };
64
65 #endif
66
67
68 static ssize_t depth_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
69 {
70         return oprofilefs_ulong_to_user(oprofile_backtrace_depth, buf, count,
71                                         offset);
72 }
73
74
75 static ssize_t depth_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
76 {
77         unsigned long val;
78         int retval;
79
80         if (*offset)
81                 return -EINVAL;
82
83         if (!oprofile_ops.backtrace)
84                 return -EINVAL;
85
86         retval = oprofilefs_ulong_from_user(&val, buf, count);
87         if (retval)
88                 return retval;
89
90         retval = oprofile_set_ulong(&oprofile_backtrace_depth, val);
91         if (retval)
92                 return retval;
93
94         return count;
95 }
96
97
98 static const struct file_operations depth_fops = {
99         .read           = depth_read,
100         .write          = depth_write,
101         .llseek         = default_llseek,
102 };
103
104
105 static ssize_t pointer_size_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
106 {
107         return oprofilefs_ulong_to_user(sizeof(void *), buf, count, offset);
108 }
109
110
111 static const struct file_operations pointer_size_fops = {
112         .read           = pointer_size_read,
113         .llseek         = default_llseek,
114 };
115
116
117 static ssize_t cpu_type_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
118 {
119         return oprofilefs_str_to_user(oprofile_ops.cpu_type, buf, count, offset);
120 }
121
122
123 static const struct file_operations cpu_type_fops = {
124         .read           = cpu_type_read,
125         .llseek         = default_llseek,
126 };
127
128
129 static ssize_t enable_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
130 {
131         return oprofilefs_ulong_to_user(oprofile_started, buf, count, offset);
132 }
133
134
135 static ssize_t enable_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
136 {
137         unsigned long val;
138         int retval;
139
140         if (*offset)
141                 return -EINVAL;
142
143         retval = oprofilefs_ulong_from_user(&val, buf, count);
144         if (retval)
145                 return retval;
146
147         if (val)
148                 retval = oprofile_start();
149         else
150                 oprofile_stop();
151
152         if (retval)
153                 return retval;
154         return count;
155 }
156
157
158 static const struct file_operations enable_fops = {
159         .read           = enable_read,
160         .write          = enable_write,
161         .llseek         = default_llseek,
162 };
163
164
165 static ssize_t dump_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
166 {
167         wake_up_buffer_waiter();
168         return count;
169 }
170
171
172 static const struct file_operations dump_fops = {
173         .write          = dump_write,
174         .llseek         = noop_llseek,
175 };
176
177 void oprofile_create_files(struct super_block *sb, struct dentry *root)
178 {
179         /* reinitialize default values */
180         oprofile_buffer_size =          BUFFER_SIZE_DEFAULT;
181         oprofile_cpu_buffer_size =      CPU_BUFFER_SIZE_DEFAULT;
182         oprofile_buffer_watershed =     BUFFER_WATERSHED_DEFAULT;
183         oprofile_time_slice =           msecs_to_jiffies(TIME_SLICE_DEFAULT);
184
185         oprofilefs_create_file(sb, root, "enable", &enable_fops);
186         oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
187         oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
188         oprofilefs_create_ulong(sb, root, "buffer_size", &oprofile_buffer_size);
189         oprofilefs_create_ulong(sb, root, "buffer_watershed", &oprofile_buffer_watershed);
190         oprofilefs_create_ulong(sb, root, "cpu_buffer_size", &oprofile_cpu_buffer_size);
191         oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops);
192         oprofilefs_create_file(sb, root, "backtrace_depth", &depth_fops);
193         oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops);
194 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
195         oprofilefs_create_file(sb, root, "time_slice", &timeout_fops);
196 #endif
197         oprofile_create_stats_files(sb, root);
198         if (oprofile_ops.create_files)
199                 oprofile_ops.create_files(sb, root);
200 }