direct/yaffs_ramem2k.c

   1 /*
   2  * YAFFS: Yet another FFS. A NAND-flash specific file system.
   3  * yaffs_ramem.c  NAND emulation on top of a chunk of RAM
   4  *
   5  * Copyright (C) 2002 Aleph One Ltd.
   6  *   for Toby Churchill Ltd and Brightstar Engineering
   7  *
   8  * Created by Charles Manning <charles@aleph1.co.uk>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  */
  15  //yaffs_ramem2k.c: RAM emulation in-kernel for 2K pages (YAFFS2)
  16
  17
  18 const char *yaffs_ramem2k_c_version = "$Id: yaffs_ramem2k.c,v 1.1 2005-08-09 01:00:37 charles Exp $";
  19
  20 #ifndef __KERNEL__
  21 #define CONFIG_YAFFS_RAM_ENABLED
  22 #else
  23 #include <linux/config.h>
  24 #endif
  25
  26 #ifdef CONFIG_YAFFS_RAM_ENABLED
  27
  28 #include "yportenv.h"
  29
  30 #include "yaffs_nandemul2k.h"
  31 #include "yaffs_guts.h"
  32 #include "yaffsinterface.h"
  33 #include "devextras.h"
  34 #include "yaffs_packedtags2.h"
  35
  36
  37
  38 #define EM_SIZE_IN_MEG (32)
  39 #define PAGE_DATA_SIZE  (2048)
  40 #define PAGE_SPARE_SIZE (64)
  41 #define PAGES_PER_BLOCK (64)
  42
  43
  44
  45 #define EM_SIZE_IN_BYTES (EM_SIZE_IN_MEG * (1<<20))
  46
  47 #define PAGE_TOTAL_SIZE (PAGE_DATA_SIZE+PAGE_SPARE_SIZE)
  48
  49 #define BLOCK_TOTAL_SIZE (PAGES_PER_BLOCK * PAGE_TOTAL_SIZE)
  50
  51 #define BLOCKS_PER_MEG ((1<<20)/(PAGES_PER_BLOCK * PAGE_DATA_SIZE))
  52
  53
  54 typedef struct
  55 {
  56         __u8 data[PAGE_TOTAL_SIZE]; // Data + spare
  57         int empty;      // is this empty?
  58 } nandemul_Page;
  59
  60
  61 typedef struct
  62 {
  63         nandemul_Page *page[PAGES_PER_BLOCK];
  64         int damaged;
  65 } nandemul_Block;
  66
  67
  68
  69 typedef struct
  70 {
  71         nandemul_Block**block;
  72         int nBlocks;
  73 } nandemul_Device;
  74
  75 static nandemul_Device ned;
  76
  77 static int sizeInMB = EM_SIZE_IN_MEG;
  78
  79
  80 static void nandemul_yield(int n)
  81 {
  82 #ifdef __KERNEL__
  83         if(n > 0) schedule_timeout(n);
  84 #endif
  85
  86 }
  87
  88
  89 static void nandemul_ReallyEraseBlock(int blockNumber)
  90 {
  91         int i;
  92
  93         nandemul_Block *blk;
  94
  95         if(blockNumber < 0 || blockNumber >= ned.nBlocks)
  96         {
  97                 return;
  98         }
  99
 100         blk = ned.block[blockNumber];
 101
 102         for(i = 0; i < PAGES_PER_BLOCK; i++)
 103         {
 104                 memset(blk->page[i],0xff,sizeof(nandemul_Page));
 105                 blk->page[i]->empty = 1;
 106         }
 107         nandemul_yield(2);
 108 }
 109
 110
 111 static int nandemul2k_CalcNBlocks(void)
 112 {
 113         return EM_SIZE_IN_MEG * BLOCKS_PER_MEG;
 114 }
 115
 116
 117
 118 static int  CheckInit(void)
 119 {
 120         static int initialised = 0;
 121
 122         int i,j;
 123
 124         int fail = 0;
 125         int nBlocks;
 126
 127         int nAllocated = 0;
 128
 129         if(initialised)
 130         {
 131                 return YAFFS_OK;
 132         }
 133
 134
 135         ned.nBlocks = nBlocks = nandemul2k_CalcNBlocks();
 136
 137
 138         ned.block = YMALLOC(sizeof(nandemul_Block*) * nBlocks );
 139
 140         if(!ned.block) return YAFFS_FAIL;
 141
 142
 143
 144
 145
 146         for(i=fail=0; i <nBlocks; i++)
 147         {
 148
 149                 nandemul_Block *blk;
 150
 151                 if(!(blk = ned.block[i] = YMALLOC(sizeof(nandemul_Block))))
 152                 {
 153                  fail = 1;
 154                 }
 155                 else
 156                 {
 157                         for(j = 0; j < PAGES_PER_BLOCK; j++)
 158                         {
 159                                 if((blk->page[j] = YMALLOC(sizeof(nandemul_Page))) == 0)
 160                                 {
 161                                         fail = 1;
 162                                 }
 163                         }
 164                         nandemul_ReallyEraseBlock(i);
 165                         ned.block[i]->damaged = 0;
 166                         nAllocated++;
 167                 }
 168         }
 169
 170         if(fail)
 171         {
 172                 //Todo thump pages
 173
 174                 for(i = 0; i < nAllocated; i++)
 175                 {
 176                         YFREE(ned.block[i]);
 177                 }
 178                 YFREE(ned.block);
 179
 180                 T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
 181                    nAllocated/64,sizeInMB));
 182                 return 0;
 183         }
 184
 185         ned.nBlocks = nBlocks;
 186
 187         initialised = 1;
 188
 189         return 1;
 190 }
 191
 192 int nandemul2k_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
 193 {
 194         int blk;
 195         int pg;
 196         int i;
 197
 198         __u8 *x;
 199
 200
 201         blk = chunkInNAND/PAGES_PER_BLOCK;
 202         pg = chunkInNAND%PAGES_PER_BLOCK;
 203
 204
 205         if(data)
 206         {
 207                 x = ned.block[blk]->page[pg]->data;
 208
 209                 for(i = 0; i < PAGE_DATA_SIZE; i++)
 210                 {
 211                         x[i] &=data[i];
 212                 }
 213
 214                 ned.block[blk]->page[pg]->empty = 0;
 215         }
 216
 217
 218         if(tags)
 219         {
 220                 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
 221
 222                 yaffs_PackTags2((yaffs_PackedTags2 *)x,tags);
 223
 224         }
 225
 226         if(tags || data)
 227         {
 228                 nandemul_yield(1);
 229         }
 230
 231         return YAFFS_OK;
 232 }
 233
 234
 235 int nandemul2k_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
 236 {
 237         int blk;
 238         int pg;
 239
 240         __u8 *x;
 241
 242
 243
 244         blk = chunkInNAND/PAGES_PER_BLOCK;
 245         pg = chunkInNAND%PAGES_PER_BLOCK;
 246
 247
 248         if(data)
 249         {
 250                 memcpy(data,ned.block[blk]->page[pg]->data,PAGE_DATA_SIZE);
 251         }
 252
 253
 254         if(tags)
 255         {
 256                 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
 257
 258                 yaffs_UnpackTags2(tags,(yaffs_PackedTags2 *)x);
 259         }
 260
 261         return YAFFS_OK;
 262 }
 263
 264
 265 static int nandemul2k_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
 266 {
 267         int blk;
 268         int pg;
 269         int i;
 270
 271
 272
 273         blk = chunkInNAND/PAGES_PER_BLOCK;
 274         pg = chunkInNAND%PAGES_PER_BLOCK;
 275
 276
 277         for(i = 0; i < PAGE_TOTAL_SIZE; i++)
 278         {
 279                 if(ned.block[blk]->page[pg]->data[i] != 0xFF)
 280                 {
 281                         return YAFFS_FAIL;
 282                 }
 283         }
 284
 285         return YAFFS_OK;
 286
 287 }
 288
 289 int nandemul2k_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
 290 {
 291
 292
 293         if(blockNumber < 0 || blockNumber >= ned.nBlocks)
 294         {
 295                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
 296         }
 297         else if(ned.block[blockNumber]->damaged)
 298         {
 299                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));
 300         }
 301         else
 302         {
 303                 nandemul_ReallyEraseBlock(blockNumber);
 304         }
 305
 306         return YAFFS_OK;
 307 }
 308
 309 int nandemul2k_InitialiseNAND(yaffs_Device *dev)
 310 {
 311         CheckInit();
 312         return YAFFS_OK;
 313 }
 314
 315 int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
 316 {
 317
 318         __u8 *x;
 319
 320         x = &ned.block[blockNo]->page[0]->data[PAGE_DATA_SIZE];
 321
 322         memset(x,0,sizeof(yaffs_PackedTags2));
 323
 324
 325         return YAFFS_OK;
 326
 327 }
 328
 329 int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, int *sequenceNumber)
 330 {
 331         yaffs_ExtendedTags tags;
 332         int chunkNo;
 333
 334         *sequenceNumber = 0;
 335
 336         chunkNo = blockNo * dev->nChunksPerBlock;
 337
 338         nandemul2k_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
 339         if(tags.blockBad)
 340         {
 341                 *state = YAFFS_BLOCK_STATE_DEAD;
 342         }
 343         else if(!tags.chunkUsed)
 344         {
 345                 *state = YAFFS_BLOCK_STATE_EMPTY;
 346         }
 347         else if(tags.chunkUsed)
 348         {
 349                 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
 350                 *sequenceNumber = tags.sequenceNumber;
 351         }
 352         return YAFFS_OK;
 353 }
 354
 355 int nandemul2k_GetBytesPerChunk(void) { return PAGE_DATA_SIZE;}
 356
 357 int nandemul2k_GetChunksPerBlock(void) { return PAGES_PER_BLOCK; }
 358 int nandemul2k_GetNumberOfBlocks(void) {return nandemul2k_CalcNBlocks();}
 359
 360
 361 #endif //YAFFS_RAM_ENABLED
 362