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}