drivers/oprofile/oprofile_files.c

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