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 <= 0)
  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         .llseek         = default_llseek,
  63 };
  64
  65 #endif
  66
  67
  68 static 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
  75 static 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
  98 static const struct file_operations depth_fops = {
  99         .read           = depth_read,
 100         .write          = depth_write,
 101         .llseek         = default_llseek,
 102 };
 103
 104
 105 static 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
 111 static const struct file_operations pointer_size_fops = {
 112         .read           = pointer_size_read,
 113         .llseek         = default_llseek,
 114 };
 115
 116
 117 static 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
 123 static const struct file_operations cpu_type_fops = {
 124         .read           = cpu_type_read,
 125         .llseek         = default_llseek,
 126 };
 127
 128
 129 static 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
 135 static 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
 159 static const struct file_operations enable_fops = {
 160         .read           = enable_read,
 161         .write          = enable_write,
 162         .llseek         = default_llseek,
 163 };
 164
 165
 166 static 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
 173 static const struct file_operations dump_fops = {
 174         .write          = dump_write,
 175         .llseek         = noop_llseek,
 176 };
 177
 178 void 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 }