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 /* Also, the top 4 bits of the object Id are set to the object type. */
  40 #define EXTRA_OBJECT_TYPE_SHIFT (28)
  41 #define EXTRA_OBJECT_TYPE_MASK  ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
  42
  43 static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 * pt)
  44 {
  45         T(YAFFS_TRACE_MTD,
  46           (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR),
  47            pt->t.objectId, pt->t.chunkId, pt->t.byteCount,
  48            pt->t.sequenceNumber));
  49 }
  50
  51 static void yaffs_DumpTags2(const yaffs_ExtendedTags * t)
  52 {
  53         T(YAFFS_TRACE_MTD,
  54           (TSTR
  55            ("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte "
  56             "%d del %d ser %d seq %d"
  57             TENDSTR), t->eccResult, t->blockBad, t->chunkUsed, t->objectId,
  58            t->chunkId, t->byteCount, t->chunkDeleted, t->serialNumber,
  59            t->sequenceNumber));
  60
  61 }
  62
  63 void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t)
  64 {
  65         pt->t.chunkId = t->chunkId;
  66         pt->t.sequenceNumber = t->sequenceNumber;
  67         pt->t.byteCount = t->byteCount;
  68         pt->t.objectId = t->objectId;
  69
  70         if (t->chunkId == 0 && t->extraHeaderInfoAvailable) {
  71                 /* Store the extra header info instead */
  72                 /* We save the parent object in the chunkId */
  73                 pt->t.chunkId = EXTRA_HEADER_INFO_FLAG
  74                         | t->extraParentObjectId;
  75                 if (t->extraIsShrinkHeader) {
  76                         pt->t.chunkId |= EXTRA_SHRINK_FLAG;
  77                 }
  78                 if (t->extraShadows) {
  79                         pt->t.chunkId |= EXTRA_SHADOWS_FLAG;
  80                 }
  81
  82                 pt->t.objectId &= ~EXTRA_OBJECT_TYPE_MASK;
  83                 pt->t.objectId |=
  84                     (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
  85
  86                 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
  87                         pt->t.byteCount = t->extraEquivalentObjectId;
  88                 } else if (t->extraObjectType == YAFFS_OBJECT_TYPE_FILE) {
  89                         pt->t.byteCount = t->extraFileLength;
  90                 } else {
  91                         pt->t.byteCount = 0;
  92                 }
  93         }
  94
  95         yaffs_DumpPackedTags2(pt);
  96         yaffs_DumpTags2(t);
  97
  98 #ifndef YAFFS_IGNORE_TAGS_ECC
  99         {
 100                 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
 101                                         sizeof(yaffs_PackedTags2TagsPart),
 102                                         &pt->ecc);
 103         }
 104 #endif
 105 }
 106
 107 void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt)
 108 {
 109
 110         memset(t, 0, sizeof(yaffs_ExtendedTags));
 111
 112         yaffs_InitialiseTags(t);
 113
 114         if (pt->t.sequenceNumber != 0xFFFFFFFF) {
 115                 /* Page is in use */
 116 #ifdef YAFFS_IGNORE_TAGS_ECC
 117                 {
 118                         t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
 119                 }
 120 #else
 121                 {
 122                         yaffs_ECCOther ecc;
 123                         int result;
 124                         yaffs_ECCCalculateOther((unsigned char *)&pt->t,
 125                                                 sizeof
 126                                                 (yaffs_PackedTags2TagsPart),
 127                                                 &ecc);
 128                         result =
 129                             yaffs_ECCCorrectOther((unsigned char *)&pt->t,
 130                                                   sizeof
 131                                                   (yaffs_PackedTags2TagsPart),
 132                                                   &pt->ecc, &ecc);
 133                         switch(result){
 134                                 case 0:
 135                                         t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
 136                                         break;
 137                                 case 1:
 138                                         t->eccResult = YAFFS_ECC_RESULT_FIXED;
 139                                         break;
 140                                 case -1:
 141                                         t->eccResult = YAFFS_ECC_RESULT_UNFIXED;
 142                                         break;
 143                                 default:
 144                                         t->eccResult = YAFFS_ECC_RESULT_UNKNOWN;
 145                         }
 146                 }
 147 #endif
 148                 t->blockBad = 0;
 149                 t->chunkUsed = 1;
 150                 t->objectId = pt->t.objectId;
 151                 t->chunkId = pt->t.chunkId;
 152                 t->byteCount = pt->t.byteCount;
 153                 t->chunkDeleted = 0;
 154                 t->serialNumber = 0;
 155                 t->sequenceNumber = pt->t.sequenceNumber;
 156
 157                 /* Do extra header info stuff */
 158
 159                 if (pt->t.chunkId & EXTRA_HEADER_INFO_FLAG) {
 160                         t->chunkId = 0;
 161                         t->byteCount = 0;
 162
 163                         t->extraHeaderInfoAvailable = 1;
 164                         t->extraParentObjectId =
 165                             pt->t.chunkId & (~(ALL_EXTRA_FLAGS));
 166                         t->extraIsShrinkHeader =
 167                             (pt->t.chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
 168                         t->extraShadows =
 169                             (pt->t.chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
 170                         t->extraObjectType =
 171                             pt->t.objectId >> EXTRA_OBJECT_TYPE_SHIFT;
 172                         t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
 173
 174                         if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
 175                                 t->extraEquivalentObjectId = pt->t.byteCount;
 176                         } else {
 177                                 t->extraFileLength = pt->t.byteCount;
 178                         }
 179                 }
 180         }
 181
 182         yaffs_DumpPackedTags2(pt);
 183         yaffs_DumpTags2(t);
 184
 185 }