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 #define TIME_SLICE_DEFAULT              1
  22
  23 unsigned long oprofile_buffer_size;
  24 unsigned long oprofile_cpu_buffer_size;
  25 unsigned long oprofile_buffer_watershed;
  26 unsigned long oprofile_time_slice;
  27
  28 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
  29
  30 static 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
  38 static 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)
  49                 return retval;
  50
  51         retval = oprofile_set_timeout(val);
  52
  53         if (retval)
  54                 return retval;
  55         return count;
  56 }
  57
  58
  59 static const struct file_operations timeout_fops = {
  60         .read           = timeout_read,
  61         .write          = timeout_write,
  62 };
  63
  64 #endif
  65
  66
  67 static ssize_t depth_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
  68 {
  69         return oprofilefs_ulong_to_user(oprofile_backtrace_depth, buf, count,
  70                                         offset);
  71 }
  72
  73
  74 static ssize_t depth_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
  75 {
  76         unsigned long val;
  77         int retval;
  78
  79         if (*offset)
  80                 return -EINVAL;
  81
  82         if (!oprofile_ops.backtrace)
  83                 return -EINVAL;
  84
  85         retval = oprofilefs_ulong_from_user(&val, buf, count);
  86         if (retval)
  87                 return retval;
  88
  89         retval = oprofile_set_ulong(&oprofile_backtrace_depth, val);
  90         if (retval)
  91                 return retval;
  92
  93         return count;
  94 }
  95
  96
  97 static const struct file_operations depth_fops = {
  98         .read           = depth_read,
  99         .write          = depth_write
 100 };
 101
 102
 103 static ssize_t pointer_size_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 104 {
 105         return oprofilefs_ulong_to_user(sizeof(void *), buf, count, offset);
 106 }
 107
 108
 109 static const struct file_operations pointer_size_fops = {
 110         .read           = pointer_size_read,
 111 };
 112
 113
 114 static ssize_t cpu_type_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 115 {
 116         return oprofilefs_str_to_user(oprofile_ops.cpu_type, buf, count, offset);
 117 }
 118
 119
 120 static const struct file_operations cpu_type_fops = {
 121         .read           = cpu_type_read,
 122 };
 123
 124
 125 static ssize_t enable_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 126 {
 127         return oprofilefs_ulong_to_user(oprofile_started, buf, count, offset);
 128 }
 129
 130
 131 static ssize_t enable_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
 132 {
 133         unsigned long val;
 134         int retval;
 135
 136         if (*offset)
 137                 return -EINVAL;
 138
 139         retval = oprofilefs_ulong_from_user(&val, buf, count);
 140         if (retval)
 141                 return retval;
 142
 143         if (val)
 144                 retval = oprofile_start();
 145         else
 146                 oprofile_stop();
 147
 148         if (retval)
 149                 return retval;
 150         return count;
 151 }
 152
 153
 154 static const struct file_operations enable_fops = {
 155         .read           = enable_read,
 156         .write          = enable_write,
 157 };
 158
 159
 160 static ssize_t dump_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
 161 {
 162         wake_up_buffer_waiter();
 163         return count;
 164 }
 165
 166
 167 static const struct file_operations dump_fops = {
 168         .write          = dump_write,
 169 };
 170
 171 void oprofile_create_files(struct super_block *sb, struct dentry *root)
 172 {
 173         /* reinitialize default values */
 174         oprofile_buffer_size =          BUFFER_SIZE_DEFAULT;
 175         oprofile_cpu_buffer_size =      CPU_BUFFER_SIZE_DEFAULT;
 176         oprofile_buffer_watershed =     BUFFER_WATERSHED_DEFAULT;
 177         oprofile_time_slice =           msecs_to_jiffies(TIME_SLICE_DEFAULT);
 178
 179         oprofilefs_create_file(sb, root, "enable", &enable_fops);
 180         oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666);
 181         oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
 182         oprofilefs_create_ulong(sb, root, "buffer_size", &oprofile_buffer_size);
 183         oprofilefs_create_ulong(sb, root, "buffer_watershed", &oprofile_buffer_watershed);
 184         oprofilefs_create_ulong(sb, root, "cpu_buffer_size", &oprofile_cpu_buffer_size);
 185         oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops);
 186         oprofilefs_create_file(sb, root, "backtrace_depth", &depth_fops);
 187         oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops);
 188 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
 189         oprofilefs_create_file(sb, root, "time_slice", &timeout_fops);
 190 #endif
 191         oprofile_create_stats_files(sb, root);
 192         if (oprofile_ops.create_files)
 193                 oprofile_ops.create_files(sb, root);
 194 }