yaffs_endian.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2011 Aleph One Ltd.
   5  *   for Toby Churchill Ltd and Brightstar Engineering
   6  *
   7  * Created by Charles Manning <charles@aleph1.co.uk>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * Endian processing functions.
  14  */
  15
  16 #include "yaffs_endian.h"
  17 #include "yaffs_guts.h"
  18
  19
  20 void yaffs_do_endian_u32(struct yaffs_dev *dev, u32 *val)
  21 {
  22         if (!dev->swap_endian)
  23                 return;
  24         *val = swap_u32(*val);
  25 }
  26
  27 void yaffs_do_endian_s32(struct yaffs_dev *dev, s32 *val)
  28 {
  29         if (!dev->swap_endian)
  30                 return;
  31         *val = swap_s32(*val);
  32 }
  33
  34 void yaffs_do_endian_oh(struct yaffs_dev *dev, struct yaffs_obj_hdr *oh)
  35 {
  36         if (!dev->swap_endian)
  37                 return;
  38         /* Change every field */
  39         oh->type = swap_u32(oh->type);
  40         oh->parent_obj_id = swap_u32(oh->parent_obj_id);
  41
  42         oh->yst_mode = swap_u32(oh->yst_mode);
  43
  44         oh->yst_uid = swap_u32(oh->yst_uid);
  45         oh->yst_gid = swap_u32(oh->yst_gid);
  46         oh->yst_atime = swap_u32(oh->yst_atime);
  47         oh->yst_mtime = swap_u32(oh->yst_mtime);
  48         oh->yst_ctime = swap_u32(oh->yst_ctime);
  49
  50         oh->file_size_low = swap_u32(oh->file_size_low);
  51
  52         oh->equiv_id = swap_u32(oh->equiv_id);
  53
  54         oh->yst_rdev = swap_u32(oh->yst_rdev);
  55
  56         oh->win_ctime[0] = swap_u32(oh->win_ctime[0]);
  57         oh->win_ctime[1] = swap_u32(oh->win_ctime[1]);
  58         oh->win_atime[0] = swap_u32(oh->win_atime[0]);
  59         oh->win_atime[1] = swap_u32(oh->win_atime[1]);
  60         oh->win_mtime[0] = swap_u32(oh->win_mtime[0]);
  61         oh->win_mtime[1] = swap_u32(oh->win_mtime[1]);
  62
  63         oh->inband_shadowed_obj_id = swap_u32(oh->inband_shadowed_obj_id);
  64         oh->inband_is_shrink = swap_u32(oh->inband_is_shrink);
  65
  66         oh->file_size_high = swap_u32(oh->file_size_high);
  67         oh->reserved[0] = swap_u32(oh->reserved[0]);
  68         oh->shadows_obj = swap_s32(oh->shadows_obj);
  69
  70         oh->is_shrink = swap_u32(oh->is_shrink);
  71 }
  72
  73
  74 void yaffs_do_endian_packed_tags2(struct yaffs_dev *dev,
  75                                 struct yaffs_packed_tags2_tags_only *ptt)
  76 {
  77         if (!dev->swap_endian)
  78                 return;
  79         ptt->seq_number = swap_u32(ptt->seq_number);
  80         ptt->obj_id = swap_u32(ptt->obj_id);
  81         ptt->chunk_id = swap_u32(ptt->chunk_id);
  82         ptt->n_bytes = swap_u32(ptt->n_bytes);
  83 }
  84
  85 void yaffs_endian_config(struct yaffs_dev *dev)
  86 {
  87         u32 x = 1;
  88
  89         if (dev->tnode_size < 1)
  90                 BUG();
  91
  92         dev->swap_endian = 0;
  93
  94         if (((char *)&x)[0] == 1) {
  95                 /* Little Endian. */
  96                 if (dev->param.stored_endian == 2 /* big endian */)
  97                         dev->swap_endian = 1;
  98         } else  {
  99                 /* Big Endian. */
 100                 if (dev->param.stored_endian == 1 /* little endian */)
 101                         dev->swap_endian = 1;
 102         }
 103
 104         if (dev->swap_endian)
 105                 dev->tn_swap_buffer = kmalloc(dev->tnode_size, GFP_NOFS);
 106 }