yaffs_endian.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2018 Aleph One Ltd.
   5  *
   6  * Created by Charles Manning <charles@aleph1.co.uk>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * Endian processing functions.
  13  */
  14
  15 #include "yaffs_endian.h"
  16 #include "yaffs_guts.h"
  17
  18
  19 void yaffs_do_endian_u32(struct yaffs_dev *dev, u32 *val)
  20 {
  21         if (!dev->swap_endian)
  22                 return;
  23         *val = swap_u32(*val);
  24 }
  25
  26 void yaffs_do_endian_s32(struct yaffs_dev *dev, s32 *val)
  27 {
  28         if (!dev->swap_endian)
  29                 return;
  30         *val = swap_s32(*val);
  31 }
  32
  33 void yaffs_do_endian_oh(struct yaffs_dev *dev, struct yaffs_obj_hdr *oh)
  34 {
  35         if (!dev->swap_endian)
  36                 return;
  37         /* Change every field */
  38         oh->type = swap_u32(oh->type);
  39         oh->parent_obj_id = swap_u32(oh->parent_obj_id);
  40
  41         oh->yst_mode = swap_u32(oh->yst_mode);
  42
  43         oh->yst_uid = swap_u32(oh->yst_uid);
  44         oh->yst_gid = swap_u32(oh->yst_gid);
  45         oh->yst_atime = swap_u32(oh->yst_atime);
  46         oh->yst_mtime = swap_u32(oh->yst_mtime);
  47         oh->yst_ctime = swap_u32(oh->yst_ctime);
  48
  49         oh->file_size_low = swap_u32(oh->file_size_low);
  50
  51         oh->equiv_id = swap_u32(oh->equiv_id);
  52
  53         oh->yst_rdev = swap_u32(oh->yst_rdev);
  54
  55         oh->win_ctime[0] = swap_u32(oh->win_ctime[0]);
  56         oh->win_ctime[1] = swap_u32(oh->win_ctime[1]);
  57         oh->win_atime[0] = swap_u32(oh->win_atime[0]);
  58         oh->win_atime[1] = swap_u32(oh->win_atime[1]);
  59         oh->win_mtime[0] = swap_u32(oh->win_mtime[0]);
  60         oh->win_mtime[1] = swap_u32(oh->win_mtime[1]);
  61
  62         oh->inband_shadowed_obj_id = swap_u32(oh->inband_shadowed_obj_id);
  63         oh->inband_is_shrink = swap_u32(oh->inband_is_shrink);
  64
  65         oh->file_size_high = swap_u32(oh->file_size_high);
  66         oh->reserved[0] = swap_u32(oh->reserved[0]);
  67         oh->shadows_obj = swap_s32(oh->shadows_obj);
  68
  69         oh->is_shrink = swap_u32(oh->is_shrink);
  70 }
  71
  72
  73 void yaffs_do_endian_packed_tags2(struct yaffs_dev *dev,
  74                                 struct yaffs_packed_tags2_tags_only *ptt)
  75 {
  76         if (!dev->swap_endian)
  77                 return;
  78         ptt->seq_number = swap_u32(ptt->seq_number);
  79         ptt->obj_id = swap_u32(ptt->obj_id);
  80         ptt->chunk_id = swap_u32(ptt->chunk_id);
  81         ptt->n_bytes = swap_u32(ptt->n_bytes);
  82 }
  83
  84 void yaffs_endian_config(struct yaffs_dev *dev)
  85 {
  86         u32 x = 1;
  87
  88         if (dev->tnode_size < 1)
  89                 BUG();
  90
  91         dev->swap_endian = 0;
  92
  93         if (((char *)&x)[0] == 1) {
  94                 /* Little Endian. */
  95                 if (dev->param.stored_endian == 2 /* big endian */)
  96                         dev->swap_endian = 1;
  97         } else  {
  98                 /* Big Endian. */
  99                 if (dev->param.stored_endian == 1 /* little endian */)
 100                         dev->swap_endian = 1;
 101         }
 102
 103         if (dev->swap_endian)
 104                 dev->tn_swap_buffer = kmalloc(dev->tnode_size, GFP_NOFS);
 105 }