direct/yaffs_ramem2k.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 /*
  15  * yaffs_ramem2k.c: RAM emulation in-kernel for 2K pages (YAFFS2)
  16  */
  17
  18
  19 const char *yaffs_ramem2k_c_version = "$Id: yaffs_ramem2k.c,v 1.5 2009-10-14 00:01:57 charles Exp $";
  20
  21 #ifndef __KERNEL__
  22 #define CONFIG_YAFFS_RAM_ENABLED
  23 #else
  24 #include <linux/config.h>
  25 #endif
  26
  27 #ifdef CONFIG_YAFFS_RAM_ENABLED
  28
  29 #include "yportenv.h"
  30
  31 #include "yaffs_nandemul2k.h"
  32 #include "yaffs_guts.h"
  33 #include "yaffsinterface.h"
  34 #include "devextras.h"
  35 #include "yaffs_packedtags2.h"
  36
  37
  38
  39 #define EM_SIZE_IN_MEG (32)
  40 #define PAGE_DATA_SIZE  (2048)
  41 #define PAGE_SPARE_SIZE (64)
  42 #define PAGES_PER_BLOCK (64)
  43
  44
  45
  46 #define EM_SIZE_IN_BYTES (EM_SIZE_IN_MEG * (1<<20))
  47
  48 #define PAGE_TOTAL_SIZE (PAGE_DATA_SIZE+PAGE_SPARE_SIZE)
  49
  50 #define BLOCK_TOTAL_SIZE (PAGES_PER_BLOCK * PAGE_TOTAL_SIZE)
  51
  52 #define BLOCKS_PER_MEG ((1<<20)/(PAGES_PER_BLOCK * PAGE_DATA_SIZE))
  53
  54
  55 typedef struct
  56 {
  57         __u8 data[PAGE_TOTAL_SIZE]; // Data + spare
  58         int empty;      // is this empty?
  59 } nandemul_Page;
  60
  61
  62 typedef struct
  63 {
  64         nandemul_Page *page[PAGES_PER_BLOCK];
  65         int damaged;
  66 } nandemul_Block;
  67
  68
  69
  70 typedef struct
  71 {
  72         nandemul_Block**block;
  73         int nBlocks;
  74 } nandemul_Device;
  75
  76 static nandemul_Device ned;
  77
  78 static int sizeInMB = EM_SIZE_IN_MEG;
  79
  80
  81 static void nandemul_yield(int n)
  82 {
  83 #ifdef __KERNEL__
  84         if(n > 0) schedule_timeout(n);
  85 #endif
  86
  87 }
  88
  89
  90 static void nandemul_ReallyEraseBlock(int blockNumber)
  91 {
  92         int i;
  93
  94         nandemul_Block *blk;
  95
  96         if(blockNumber < 0 || blockNumber >= ned.nBlocks)
  97         {
  98                 return;
  99         }
 100
 101         blk = ned.block[blockNumber];
 102
 103         for(i = 0; i < PAGES_PER_BLOCK; i++)
 104         {
 105                 memset(blk->page[i],0xff,sizeof(nandemul_Page));
 106                 blk->page[i]->empty = 1;
 107         }
 108         nandemul_yield(2);
 109 }
 110
 111
 112 static int nandemul2k_CalcNBlocks(void)
 113 {
 114         return EM_SIZE_IN_MEG * BLOCKS_PER_MEG;
 115 }
 116
 117
 118
 119 static int  CheckInit(void)
 120 {
 121         static int initialised = 0;
 122
 123         int i,j;
 124
 125         int fail = 0;
 126         int nBlocks;
 127
 128         int nAllocated = 0;
 129
 130         if(initialised)
 131         {
 132                 return YAFFS_OK;
 133         }
 134
 135
 136         ned.nBlocks = nBlocks = nandemul2k_CalcNBlocks();
 137
 138
 139         ned.block = YMALLOC(sizeof(nandemul_Block*) * nBlocks );
 140
 141         if(!ned.block) return YAFFS_FAIL;
 142
 143
 144
 145
 146
 147         for(i=fail=0; i <nBlocks; i++)
 148         {
 149
 150                 nandemul_Block *blk;
 151
 152                 if(!(blk = ned.block[i] = YMALLOC(sizeof(nandemul_Block))))
 153                 {
 154                  fail = 1;
 155                 }
 156                 else
 157                 {
 158                         for(j = 0; j < PAGES_PER_BLOCK; j++)
 159                         {
 160                                 if((blk->page[j] = YMALLOC(sizeof(nandemul_Page))) == 0)
 161                                 {
 162                                         fail = 1;
 163                                 }
 164                         }
 165                         nandemul_ReallyEraseBlock(i);
 166                         ned.block[i]->damaged = 0;
 167                         nAllocated++;
 168                 }
 169         }
 170
 171         if(fail)
 172         {
 173                 //Todo thump pages
 174
 175                 for(i = 0; i < nAllocated; i++)
 176                 {
 177                         YFREE(ned.block[i]);
 178                 }
 179                 YFREE(ned.block);
 180
 181                 T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
 182                    nAllocated/64,sizeInMB));
 183                 return 0;
 184         }
 185
 186         ned.nBlocks = nBlocks;
 187
 188         initialised = 1;
 189
 190         return 1;
 191 }
 192
 193 int nandemul2k_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, const yaffs_ExtendedTags *tags)
 194 {
 195         int blk;
 196         int pg;
 197         int i;
 198
 199         __u8 *x;
 200
 201
 202         blk = chunkInNAND/PAGES_PER_BLOCK;
 203         pg = chunkInNAND%PAGES_PER_BLOCK;
 204
 205
 206         if(data)
 207         {
 208                 x = ned.block[blk]->page[pg]->data;
 209
 210                 for(i = 0; i < PAGE_DATA_SIZE; i++)
 211                 {
 212                         x[i] &=data[i];
 213                 }
 214
 215                 ned.block[blk]->page[pg]->empty = 0;
 216         }
 217
 218
 219         if(tags)
 220         {
 221                 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
 222
 223                 yaffs_PackTags2(dev,(yaffs_PackedTags2 *)x,tags);
 224
 225         }
 226
 227         if(tags || data)
 228         {
 229                 nandemul_yield(1);
 230         }
 231
 232         return YAFFS_OK;
 233 }
 234
 235
 236 int nandemul2k_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
 237 {
 238         int blk;
 239         int pg;
 240
 241         __u8 *x;
 242
 243
 244
 245         blk = chunkInNAND/PAGES_PER_BLOCK;
 246         pg = chunkInNAND%PAGES_PER_BLOCK;
 247
 248
 249         if(data)
 250         {
 251                 memcpy(data,ned.block[blk]->page[pg]->data,PAGE_DATA_SIZE);
 252         }
 253
 254
 255         if(tags)
 256         {
 257                 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
 258
 259                 yaffs_UnpackTags2(dev,tags,(yaffs_PackedTags2 *)x);
 260         }
 261
 262         return YAFFS_OK;
 263 }
 264
 265
 266 static int nandemul2k_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
 267 {
 268         int blk;
 269         int pg;
 270         int i;
 271
 272
 273
 274         blk = chunkInNAND/PAGES_PER_BLOCK;
 275         pg = chunkInNAND%PAGES_PER_BLOCK;
 276
 277
 278         for(i = 0; i < PAGE_TOTAL_SIZE; i++)
 279         {
 280                 if(ned.block[blk]->page[pg]->data[i] != 0xFF)
 281                 {
 282                         return YAFFS_FAIL;
 283                 }
 284         }
 285
 286         return YAFFS_OK;
 287
 288 }
 289
 290 int nandemul2k_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
 291 {
 292
 293
 294         if(blockNumber < 0 || blockNumber >= ned.nBlocks)
 295         {
 296                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
 297         }
 298         else if(ned.block[blockNumber]->damaged)
 299         {
 300                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));
 301         }
 302         else
 303         {
 304                 nandemul_ReallyEraseBlock(blockNumber);
 305         }
 306
 307         return YAFFS_OK;
 308 }
 309
 310 int nandemul2k_InitialiseNAND(yaffs_Device *dev)
 311 {
 312         CheckInit();
 313         return YAFFS_OK;
 314 }
 315
 316 int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
 317 {
 318
 319         __u8 *x;
 320
 321         x = &ned.block[blockNo]->page[0]->data[PAGE_DATA_SIZE];
 322
 323         memset(x,0,sizeof(yaffs_PackedTags2));
 324
 325
 326         return YAFFS_OK;
 327
 328 }
 329
 330 int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, __u32  *sequenceNumber)
 331 {
 332         yaffs_ExtendedTags tags;
 333         int chunkNo;
 334
 335         *sequenceNumber = 0;
 336
 337         chunkNo = blockNo * dev->nChunksPerBlock;
 338
 339         nandemul2k_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
 340         if(tags.blockBad)
 341         {
 342                 *state = YAFFS_BLOCK_STATE_DEAD;
 343         }
 344         else if(!tags.chunkUsed)
 345         {
 346                 *state = YAFFS_BLOCK_STATE_EMPTY;
 347         }
 348         else if(tags.chunkUsed)
 349         {
 350                 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
 351                 *sequenceNumber = tags.sequenceNumber;
 352         }
 353         return YAFFS_OK;
 354 }
 355
 356 int nandemul2k_GetBytesPerChunk(void) { return PAGE_DATA_SIZE;}
 357
 358 int nandemul2k_GetChunksPerBlock(void) { return PAGES_PER_BLOCK; }
 359 int nandemul2k_GetNumberOfBlocks(void) {return nandemul2k_CalcNBlocks();}
 360
 361
 362 #endif //YAFFS_RAM_ENABLED
 363