/* nommu.c: mmu-less memory info files
   *
   * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   * Written by David Howells (dhowells@redhat.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 <linux/init.h>
  #include <linux/module.h>
  #include <linux/errno.h>
  #include <linux/time.h>
  #include <linux/kernel.h>
  #include <linux/string.h>
  #include <linux/mman.h>
  #include <linux/proc_fs.h>
  #include <linux/mm.h>
  #include <linux/mmzone.h>
  #include <linux/pagemap.h>
  #include <linux/swap.h>

  #include <linux/smp.h>
  #include <linux/seq_file.h>
  #include <linux/hugetlb.h>
  #include <linux/vmalloc.h>
  #include <asm/uaccess.h>
  #include <asm/pgtable.h>
  #include <asm/tlb.h>
  #include <asm/div64.h>
  #include "internal.h"
  
  /*

   * display a single region to a sequenced file

   */

  static int nommu_region_show(struct seq_file *m, struct vm_region *region)

  {

  	unsigned long ino = 0;
  	struct file *file;
  	dev_t dev = 0;
  	int flags, len;

  	flags = region->vm_flags;
  	file = region->vm_file;

  
  	if (file) {

  		struct inode *inode = region->vm_file->f_path.dentry->d_inode;

  		dev = inode->i_sb->s_dev;
  		ino = inode->i_ino;
  	}
  
  	seq_printf(m,

  		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",

  		   region->vm_start,
  		   region->vm_end,

  		   flags & VM_READ ? 'r' : '-',
  		   flags & VM_WRITE ? 'w' : '-',
  		   flags & VM_EXEC ? 'x' : '-',
  		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',

  		   ((loff_t)region->vm_pgoff) << PAGE_SHIFT,

  		   MAJOR(dev), MINOR(dev), ino, &len);
  
  	if (file) {
  		len = 25 + sizeof(void *) * 6 - len;
  		if (len < 1)
  			len = 1;
  		seq_printf(m, "%*c", len, ' ');

  		seq_path(m, &file->f_path, "");

  	}
  
  	seq_putc(m, '
  ');
  	return 0;
  }

  /*

   * display a list of all the REGIONs the kernel knows about

   * - nommu kernels have a single flat list

   */

  static int nommu_region_list_show(struct seq_file *m, void *_p)

  {

  	struct rb_node *p = _p;

  	return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));

  }

  static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)

  {

  	struct rb_node *p;

  	loff_t pos = *_pos;

  	down_read(&nommu_region_sem);

  	for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
  		if (pos-- == 0)
  			return p;
  	return NULL;

  }

  static void nommu_region_list_stop(struct seq_file *m, void *v)

  {

  	up_read(&nommu_region_sem);

  }

  static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)

  {
  	(*pos)++;
  	return rb_next((struct rb_node *) v);
  }

  static const struct seq_operations proc_nommu_region_list_seqop = {

  	.start	= nommu_region_list_start,
  	.next	= nommu_region_list_next,
  	.stop	= nommu_region_list_stop,
  	.show	= nommu_region_list_show

  };

  static int proc_nommu_region_list_open(struct inode *inode, struct file *file)

  {

  	return seq_open(file, &proc_nommu_region_list_seqop);

  }

  static const struct file_operations proc_nommu_region_list_operations = {
  	.open    = proc_nommu_region_list_open,

  	.read    = seq_read,
  	.llseek  = seq_lseek,
  	.release = seq_release,
  };
  
  static int __init proc_nommu_init(void)
  {

  	proc_create("maps", S_IRUGO, NULL, &proc_nommu_region_list_operations);

  	return 0;
  }
  
  module_init(proc_nommu_init);