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
  13 #include "event_buffer.h"
  14 #include "oprofile_stats.h"
  15 #include "oprof.h"
  16
  17 unsigned long fs_buffer_size = 131072;
  18 unsigned long fs_cpu_buffer_size = 8192;
  19 unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */
  20
  21
  22 static ssize_t pointer_size_read(struct file * file, char __user * buf, size_t count, loff_t * offset)
  23 {
  24         return oprofilefs_ulong_to_user(sizeof(void *), buf, count, offset);
  25 }
  26
  27
  28 static struct file_operations pointer_size_fops = {
  29         .read           = pointer_size_read,
  30 };
  31
  32
  33 static ssize_t cpu_type_read(struct file * file, char __user * buf, size_t count, loff_t * offset)
  34 {
  35         return oprofilefs_str_to_user(oprofile_ops->cpu_type, buf, count, offset);
  36 }
  37
  38
  39 static struct file_operations cpu_type_fops = {
  40         .read           = cpu_type_read,
  41 };
  42
  43
  44 static ssize_t enable_read(struct file * file, char __user * buf, size_t count, loff_t * offset)
  45 {
  46         return oprofilefs_ulong_to_user(oprofile_started, buf, count, offset);
  47 }
  48
  49
  50 static ssize_t enable_write(struct file *file, char const __user * buf, size_t count, loff_t * offset)
  51 {
  52         unsigned long val;
  53         int retval;
  54
  55         if (*offset)
  56                 return -EINVAL;
  57
  58         retval = oprofilefs_ulong_from_user(&val, buf, count);
  59         if (retval)
  60                 return retval;
  61
  62         if (val)
  63                 retval = oprofile_start();
  64         else
  65                 oprofile_stop();
  66
  67         if (retval)
  68                 return retval;
  69         return count;
  70 }
  71
  72
  73 static struct file_operations enable_fops = {
  74         .read           = enable_read,
  75         .write          = enable_write,
  76 };
  77
  78
  79 static ssize_t dump_write(struct file *file, char const __user * buf, size_t count, loff_t * offset)
  80 {
  81         wake_up_buffer_waiter();
  82         return count;
  83 }
  84
  85
  86 static struct file_operations dump_fops = {
  87         .write          = dump_write,
  88 };
  89
  90 void oprofile_create_files(struct super_block * sb, struct dentry * root)
  91 {
  92         oprofilefs_create_file(sb, root, "enable", &enable_fops);
  93         oprofilefs_create_file(sb, root, "dump", &dump_fops);
  94         oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops);
  95         oprofilefs_create_ulong(sb, root, "buffer_size", &fs_buffer_size);
  96         oprofilefs_create_ulong(sb, root, "buffer_watershed", &fs_buffer_watershed);
  97         oprofilefs_create_ulong(sb, root, "cpu_buffer_size", &fs_cpu_buffer_size);
  98         oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops);
  99         oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops);
 100         oprofile_create_stats_files(sb, root);
 101         if (oprofile_ops->create_files)
 102                 oprofile_ops->create_files(sb, root);
 103 }