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
23unsigned long oprofile_buffer_size;
24unsigned long oprofile_cpu_buffer_size;
25unsigned long oprofile_buffer_watershed;
26unsigned long oprofile_time_slice;
27
28#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
29
30static 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
38static 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 <= 0)
49 return retval;
50
51 retval = oprofile_set_timeout(val);
52
53 if (retval)
54 return retval;
55 return count;
56}
57
58
59static const struct file_operations timeout_fops = {
60 .read = timeout_read,
61 .write = timeout_write,
62 .llseek = default_llseek,
63};
64
65#endif
66
67
68static 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
75static 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 <= 0)
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
98static const struct file_operations depth_fops = {
99 .read = depth_read,
100 .write = depth_write,
101 .llseek = default_llseek,
102};
103
104
105static 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
111static const struct file_operations pointer_size_fops = {
112 .read = pointer_size_read,
113 .llseek = default_llseek,
114};
115
116
117static 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
123static const struct file_operations cpu_type_fops = {
124 .read = cpu_type_read,
125 .llseek = default_llseek,
126};
127
128
129static 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
135static 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 <= 0)
145 return retval;
146
147 retval = 0;
148 if (val)
149 retval = oprofile_start();
150 else
151 oprofile_stop();
152
153 if (retval)
154 return retval;
155 return count;
156}
157
158
159static const struct file_operations enable_fops = {
160 .read = enable_read,
161 .write = enable_write,
162 .llseek = default_llseek,
163};
164
165
166static ssize_t dump_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
167{
168 wake_up_buffer_waiter();
169 return count;
170}
171
172
173static const struct file_operations dump_fops = {
174 .write = dump_write,
175 .llseek = noop_llseek,
176};
177
178void oprofile_create_files(struct dentry *root)
179{
180 /* reinitialize default values */
181 oprofile_buffer_size = BUFFER_SIZE_DEFAULT;
182 oprofile_cpu_buffer_size = CPU_BUFFER_SIZE_DEFAULT;
183 oprofile_buffer_watershed = BUFFER_WATERSHED_DEFAULT;
184 oprofile_time_slice = msecs_to_jiffies(TIME_SLICE_DEFAULT);
185
186 oprofilefs_create_file(root, "enable", &enable_fops);
187 oprofilefs_create_file_perm(root, "dump", &dump_fops, 0666);
188 oprofilefs_create_file(root, "buffer", &event_buffer_fops);
189 oprofilefs_create_ulong(root, "buffer_size", &oprofile_buffer_size);
190 oprofilefs_create_ulong(root, "buffer_watershed", &oprofile_buffer_watershed);
191 oprofilefs_create_ulong(root, "cpu_buffer_size", &oprofile_cpu_buffer_size);
192 oprofilefs_create_file(root, "cpu_type", &cpu_type_fops);
193 oprofilefs_create_file(root, "backtrace_depth", &depth_fops);
194 oprofilefs_create_file(root, "pointer_size", &pointer_size_fops);
195#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
196 oprofilefs_create_file(root, "time_slice", &timeout_fops);
197#endif
198 oprofile_create_stats_files(root);
199 if (oprofile_ops.create_files)
200 oprofile_ops.create_files(root);
201}
202