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
timeout_read(struct file * file,char __user * buf,size_t count,loff_t * offset)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
timeout_write(struct file * file,char const __user * buf,size_t count,loff_t * offset)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 <= 0)
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
depth_read(struct file * file,char __user * buf,size_t count,loff_t * offset)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
depth_write(struct file * file,char const __user * buf,size_t count,loff_t * offset)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 <= 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
98 static const struct file_operations depth_fops = {
99 .read = depth_read,
100 .write = depth_write,
101 .llseek = default_llseek,
102 };
103
104
pointer_size_read(struct file * file,char __user * buf,size_t count,loff_t * offset)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
cpu_type_read(struct file * file,char __user * buf,size_t count,loff_t * offset)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
enable_read(struct file * file,char __user * buf,size_t count,loff_t * offset)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
enable_write(struct file * file,char const __user * buf,size_t count,loff_t * offset)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 <= 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
159 static const struct file_operations enable_fops = {
160 .read = enable_read,
161 .write = enable_write,
162 .llseek = default_llseek,
163 };
164
165
dump_write(struct file * file,char const __user * buf,size_t count,loff_t * offset)166 static 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
173 static const struct file_operations dump_fops = {
174 .write = dump_write,
175 .llseek = noop_llseek,
176 };
177
oprofile_create_files(struct dentry * root)178 void 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