linux/drivers/oprofile/oprofile_files.c
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   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 super_block *sb, 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(sb, root, "enable", &enable_fops);
 187        oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
 188        oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
 189        oprofilefs_create_ulong(sb, root, "buffer_size", &oprofile_buffer_size);
 190        oprofilefs_create_ulong(sb, root, "buffer_watershed", &oprofile_buffer_watershed);
 191        oprofilefs_create_ulong(sb, root, "cpu_buffer_size", &oprofile_cpu_buffer_size);
 192        oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops);
 193        oprofilefs_create_file(sb, root, "backtrace_depth", &depth_fops);
 194        oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops);
 195#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
 196        oprofilefs_create_file(sb, root, "time_slice", &timeout_fops);
 197#endif
 198        oprofile_create_stats_files(sb, root);
 199        if (oprofile_ops.create_files)
 200                oprofile_ops.create_files(sb, root);
 201}
 202
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