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