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kernel/linux-rt-4.4.41/arch/mips/mm/sc-debugfs.c 1.75 KB
5113f6f70   김현기   kernel add
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  /*
   * Copyright (C) 2015 Imagination Technologies
   * Author: Paul Burton <paul.burton@imgtec.com>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the
   * Free Software Foundation; either version 2 of the License, or (at your
   * option) any later version.
   */
  
  #include <asm/bcache.h>
  #include <asm/debug.h>
  #include <asm/uaccess.h>
  #include <linux/debugfs.h>
  #include <linux/init.h>
  
  static ssize_t sc_prefetch_read(struct file *file, char __user *user_buf,
  				size_t count, loff_t *ppos)
  {
  	bool enabled = bc_prefetch_is_enabled();
  	char buf[3];
  
  	buf[0] = enabled ? 'Y' : 'N';
  	buf[1] = '
  ';
  	buf[2] = 0;
  
  	return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
  }
  
  static ssize_t sc_prefetch_write(struct file *file,
  				 const char __user *user_buf,
  				 size_t count, loff_t *ppos)
  {
  	char buf[32];
  	ssize_t buf_size;
  	bool enabled;
  	int err;
  
  	buf_size = min(count, sizeof(buf) - 1);
  	if (copy_from_user(buf, user_buf, buf_size))
  		return -EFAULT;
  
  	buf[buf_size] = '\0';
  	err = strtobool(buf, &enabled);
  	if (err)
  		return err;
  
  	if (enabled)
  		bc_prefetch_enable();
  	else
  		bc_prefetch_disable();
  
  	return count;
  }
  
  static const struct file_operations sc_prefetch_fops = {
  	.open = simple_open,
  	.llseek = default_llseek,
  	.read = sc_prefetch_read,
  	.write = sc_prefetch_write,
  };
  
  static int __init sc_debugfs_init(void)
  {
  	struct dentry *dir, *file;
  
  	if (!mips_debugfs_dir)
  		return -ENODEV;
  
  	dir = debugfs_create_dir("l2cache", mips_debugfs_dir);
  	if (IS_ERR(dir))
  		return PTR_ERR(dir);
  
  	file = debugfs_create_file("prefetch", S_IRUGO | S_IWUSR, dir,
  				   NULL, &sc_prefetch_fops);
  	if (IS_ERR(file))
  		return PTR_ERR(file);
  
  	return 0;
  }
  late_initcall(sc_debugfs_init);