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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 unsigned long fs_buffer_size = 131072;
  19 unsigned long fs_cpu_buffer_size = 8192;
  20 unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */
  21
  22 static ssize_t timeout_read(struct file *file, char __user *buf,
  23                 size_t count, loff_t *offset)
  24 {
  25         return oprofilefs_ulong_to_user(jiffies_to_msecs(timeout_jiffies),
  26                                 buf, count, offset);
  27 }
  28
  29
  30 static ssize_t timeout_write(struct file *file, char const __user *buf,
  31                 size_t count, loff_t *offset)
  32 {
  33         unsigned long val;
  34         int retval;
  35
  36         if (*offset)
  37                 return -EINVAL;
  38
  39         retval = oprofilefs_ulong_from_user(&val, buf, count);
  40         if (retval)
  41                 return retval;
  42
  43         retval = oprofile_set_timeout(val);
  44
  45         if (retval)
  46                 return retval;
  47         return count;
  48 }
  49
  50 static const struct file_operations timeout_fops = {
  51         .read           = timeout_read,
  52         .write          = timeout_write,
  53 };
  54
  55
  56 static ssize_t depth_read(struct file * file, char __user * buf, size_t count, loff_t * offset)
  57 {
  58         return oprofilefs_ulong_to_user(backtrace_depth, buf, count, offset);
  59 }
  60
  61
  62 static ssize_t depth_write(struct file * file, char const __user * buf, size_t count, loff_t * offset)
  63 {
  64         unsigned long val;
  65         int retval;
  66
  67         if (*offset)
  68                 return -EINVAL;
  69
  70         retval = oprofilefs_ulong_from_user(&val, buf, count);
  71         if (retval)
  72                 return retval;
  73
  74         retval = oprofile_set_backtrace(val);
  75
  76         if (retval)
  77                 return retval;
  78         return count;
  79 }
  80
  81
  82 static const struct file_operations depth_fops = {
  83         .read           = depth_read,
  84         .write          = depth_write
  85 };
  86
  87
  88 static ssize_t pointer_size_read(struct file * file, char __user * buf, size_t count, loff_t * offset)
  89 {
  90         return oprofilefs_ulong_to_user(sizeof(void *), buf, count, offset);
  91 }
  92
  93
  94 static const struct file_operations pointer_size_fops = {
  95         .read           = pointer_size_read,
  96 };
  97
  98
  99 static ssize_t cpu_type_read(struct file * file, char __user * buf, size_t count, loff_t * offset)
 100 {
 101         return oprofilefs_str_to_user(oprofile_ops.cpu_type, buf, count, offset);
 102 }
 103
 104
 105 static const struct file_operations cpu_type_fops = {
 106         .read           = cpu_type_read,
 107 };
 108
 109
 110 static ssize_t enable_read(struct file * file, char __user * buf, size_t count, loff_t * offset)
 111 {
 112         return oprofilefs_ulong_to_user(oprofile_started, buf, count, offset);
 113 }
 114
 115
 116 static ssize_t enable_write(struct file * file, char const __user * buf, size_t count, loff_t * offset)
 117 {
 118         unsigned long val;
 119         int retval;
 120
 121         if (*offset)
 122                 return -EINVAL;
 123         retval = oprofilefs_ulong_from_user(&val, buf, count);
 124         if (retval)
 125                 return retval;
 126
 127         if (val)
 128                 retval = oprofile_start();
 129         else
 130                 oprofile_stop();
 131
 132         if (retval)
 133                 return retval;
 134         return count;
 135 }
 136
 137
 138 static const struct file_operations enable_fops = {
 139         .read           = enable_read,
 140         .write          = enable_write,
 141 };
 142
 143
 144 static ssize_t dump_write(struct file * file, char const __user * buf, size_t count, loff_t * offset)
 145 {
 146         wake_up_buffer_waiter();
 147         return count;
 148 }
 149
 150
 151 static const struct file_operations dump_fops = {
 152         .write          = dump_write,
 153 };
 154
 155 void oprofile_create_files(struct super_block * sb, struct dentry * root)
 156 {
 157         oprofilefs_create_file(sb, root, "enable", &enable_fops);
 158         oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
 159         oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
 160         oprofilefs_create_ulong(sb, root, "buffer_size", &fs_buffer_size);
 161         oprofilefs_create_ulong(sb, root, "buffer_watershed", &fs_buffer_watershed);
 162         oprofilefs_create_ulong(sb, root, "cpu_buffer_size", &fs_cpu_buffer_size);
 163         oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops);
 164         oprofilefs_create_file(sb, root, "backtrace_depth", &depth_fops);
 165         oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops);
 166         oprofilefs_create_file(sb, root, "timeout_ms", &timeout_fops);
 167         oprofile_create_stats_files(sb, root);
 168         if (oprofile_ops.create_files)
 169                 oprofile_ops.create_files(sb, root);
 170 }