fs/yaffs2/yaffs_packedtags2.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2007 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
  14 /* XXX U-BOOT XXX */
  15 #include <common.h>
  16
  17 #include "yaffs_packedtags2.h"
  18 #include "yportenv.h"
  19 #include "yaffs_tagsvalidity.h"
  20
  21 /* This code packs a set of extended tags into a binary structure for
  22  * NAND storage
  23  */
  24
  25 /* Some of the information is "extra" struff which can be packed in to
  26  * speed scanning
  27  * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
  28  */
  29
  30 /* Extra flags applied to chunkId */
  31
  32 #define EXTRA_HEADER_INFO_FLAG  0x80000000
  33 #define EXTRA_SHRINK_FLAG       0x40000000
  34 #define EXTRA_SHADOWS_FLAG      0x20000000
  35 #define EXTRA_SPARE_FLAGS       0x10000000
  36
  37 #define ALL_EXTRA_FLAGS         0xF0000000
  38
  39 //#define YAFFS_IGNORE_TAGS_ECC 1
  40 /* Also, the top 4 bits of the object Id are set to the object type. */
  41 #define EXTRA_OBJECT_TYPE_SHIFT (28)
  42 #define EXTRA_OBJECT_TYPE_MASK  ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
  43
  44 static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 * pt)
  45 {
  46         T(YAFFS_TRACE_MTD,
  47           (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR),
  48            pt->t.objectId, pt->t.chunkId, pt->t.byteCount,
  49            pt->t.sequenceNumber));
  50 }
  51
  52 static void yaffs_DumpTags2(const yaffs_ExtendedTags * t)
  53 {
  54         T(YAFFS_TRACE_MTD,
  55           (TSTR
  56            ("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte "
  57             "%d del %d ser %d seq %d"
  58             TENDSTR), t->eccResult, t->blockBad, t->chunkUsed, t->objectId,
  59            t->chunkId, t->byteCount, t->chunkDeleted, t->serialNumber,
  60            t->sequenceNumber));
  61
  62 }
  63
  64 void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t)
  65 {
  66         pt->t.chunkId = t->chunkId;
  67         pt->t.sequenceNumber = t->sequenceNumber;
  68         pt->t.byteCount = t->byteCount;
  69         pt->t.objectId = t->objectId;
  70
  71         if (t->chunkId == 0 && t->extraHeaderInfoAvailable) {
  72                 /* Store the extra header info instead */
  73                 /* We save the parent object in the chunkId */
  74                 pt->t.chunkId = EXTRA_HEADER_INFO_FLAG
  75                         | t->extraParentObjectId;
  76                 if (t->extraIsShrinkHeader) {
  77                         pt->t.chunkId |= EXTRA_SHRINK_FLAG;
  78                 }
  79                 if (t->extraShadows) {
  80                         pt->t.chunkId |= EXTRA_SHADOWS_FLAG;
  81                 }
  82
  83                 pt->t.objectId &= ~EXTRA_OBJECT_TYPE_MASK;
  84                 pt->t.objectId |=
  85                     (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
  86
  87                 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
  88                         pt->t.byteCount = t->extraEquivalentObjectId;
  89                 } else if (t->extraObjectType == YAFFS_OBJECT_TYPE_FILE) {
  90                         pt->t.byteCount = t->extraFileLength;
  91                 } else {
  92                         pt->t.byteCount = 0;
  93                 }
  94         }
  95
  96         yaffs_DumpPackedTags2(pt);
  97         yaffs_DumpTags2(t);
  98
  99 #ifndef YAFFS_IGNORE_TAGS_ECC
 100         {
 101                 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
 102                                         sizeof(yaffs_PackedTags2TagsPart),
 103                                         &pt->ecc);
 104         }
 105 #endif
 106 }
 107
 108 void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt)
 109 {
 110
 111         memset(t, 0, sizeof(yaffs_ExtendedTags));
 112
 113         yaffs_InitialiseTags(t);
 114
 115         if (pt->t.sequenceNumber != 0xFFFFFFFF) {
 116                 /* Page is in use */
 117 #ifdef YAFFS_IGNORE_TAGS_ECC
 118                 {
 119                         t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
 120                 }
 121 #else
 122                 {
 123                         yaffs_ECCOther ecc;
 124                         int result;
 125                         yaffs_ECCCalculateOther((unsigned char *)&pt->t,
 126                                                 sizeof
 127                                                 (yaffs_PackedTags2TagsPart),
 128                                                 &ecc);
 129                         result =
 130                             yaffs_ECCCorrectOther((unsigned char *)&pt->t,
 131                                                   sizeof
 132                                                   (yaffs_PackedTags2TagsPart),
 133                                                   &pt->ecc, &ecc);
 134                         switch(result){
 135                                 case 0:
 136                                         t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
 137                                         break;
 138                                 case 1:
 139                                         t->eccResult = YAFFS_ECC_RESULT_FIXED;
 140                                         break;
 141                                 case -1:
 142                                         t->eccResult = YAFFS_ECC_RESULT_UNFIXED;
 143                                         break;
 144                                 default:
 145                                         t->eccResult = YAFFS_ECC_RESULT_UNKNOWN;
 146                         }
 147                 }
 148 #endif
 149                 t->blockBad = 0;
 150                 t->chunkUsed = 1;
 151                 t->objectId = pt->t.objectId;
 152                 t->chunkId = pt->t.chunkId;
 153                 t->byteCount = pt->t.byteCount;
 154                 t->chunkDeleted = 0;
 155                 t->serialNumber = 0;
 156                 t->sequenceNumber = pt->t.sequenceNumber;
 157
 158                 /* Do extra header info stuff */
 159
 160                 if (pt->t.chunkId & EXTRA_HEADER_INFO_FLAG) {
 161                         t->chunkId = 0;
 162                         t->byteCount = 0;
 163
 164                         t->extraHeaderInfoAvailable = 1;
 165                         t->extraParentObjectId =
 166                             pt->t.chunkId & (~(ALL_EXTRA_FLAGS));
 167                         t->extraIsShrinkHeader =
 168                             (pt->t.chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
 169                         t->extraShadows =
 170                             (pt->t.chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
 171                         t->extraObjectType =
 172                             pt->t.objectId >> EXTRA_OBJECT_TYPE_SHIFT;
 173                         t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
 174
 175                         if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
 176                                 t->extraEquivalentObjectId = pt->t.byteCount;
 177                         } else {
 178                                 t->extraFileLength = pt->t.byteCount;
 179                         }
 180                 }
 181         }
 182
 183         yaffs_DumpPackedTags2(pt);
 184         yaffs_DumpTags2(t);
 185
 186 }