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 1.6 2010-01-11 04:06:47 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 #include "yaffs_trace.h"
  31
  32 #include "yaffs_nandemul2k.h"
  33 #include "yaffs_guts.h"
  34 #include "yaffsinterface.h"
  35 #include "devextras.h"
  36 #include "yaffs_packedtags2.h"
  37
  38
  39
  40 #define EM_SIZE_IN_MEG (32)
  41 #define PAGE_DATA_SIZE  (2048)
  42 #define PAGE_SPARE_SIZE (64)
  43 #define PAGES_PER_BLOCK (64)
  44
  45
  46
  47 #define EM_SIZE_IN_BYTES (EM_SIZE_IN_MEG * (1<<20))
  48
  49 #define PAGE_TOTAL_SIZE (PAGE_DATA_SIZE+PAGE_SPARE_SIZE)
  50
  51 #define BLOCK_TOTAL_SIZE (PAGES_PER_BLOCK * PAGE_TOTAL_SIZE)
  52
  53 #define BLOCKS_PER_MEG ((1<<20)/(PAGES_PER_BLOCK * PAGE_DATA_SIZE))
  54
  55
  56 typedef struct
  57 {
  58         __u8 data[PAGE_TOTAL_SIZE]; // Data + spare
  59         int empty;      // is this empty?
  60 } nandemul_Page;
  61
  62
  63 typedef struct
  64 {
  65         nandemul_Page *page[PAGES_PER_BLOCK];
  66         int damaged;
  67 } nandemul_Block;
  68
  69
  70
  71 typedef struct
  72 {
  73         nandemul_Block**block;
  74         int nBlocks;
  75 } nandemul_Device;
  76
  77 static nandemul_Device ned;
  78
  79 static int sizeInMB = EM_SIZE_IN_MEG;
  80
  81
  82 static void nandemul_yield(int n)
  83 {
  84 #ifdef __KERNEL__
  85         if(n > 0) schedule_timeout(n);
  86 #endif
  87
  88 }
  89
  90
  91 static void nandemul_ReallyEraseBlock(int blockNumber)
  92 {
  93         int i;
  94
  95         nandemul_Block *blk;
  96
  97         if(blockNumber < 0 || blockNumber >= ned.nBlocks)
  98         {
  99                 return;
 100         }
 101
 102         blk = ned.block[blockNumber];
 103
 104         for(i = 0; i < PAGES_PER_BLOCK; i++)
 105         {
 106                 memset(blk->page[i],0xff,sizeof(nandemul_Page));
 107                 blk->page[i]->empty = 1;
 108         }
 109         nandemul_yield(2);
 110 }
 111
 112
 113 static int nandemul2k_CalcNBlocks(void)
 114 {
 115         return EM_SIZE_IN_MEG * BLOCKS_PER_MEG;
 116 }
 117
 118
 119
 120 static int  CheckInit(void)
 121 {
 122         static int initialised = 0;
 123
 124         int i,j;
 125
 126         int fail = 0;
 127         int nBlocks;
 128
 129         int nAllocated = 0;
 130
 131         if(initialised)
 132         {
 133                 return YAFFS_OK;
 134         }
 135
 136
 137         ned.nBlocks = nBlocks = nandemul2k_CalcNBlocks();
 138
 139
 140         ned.block = YMALLOC(sizeof(nandemul_Block*) * nBlocks );
 141
 142         if(!ned.block) return YAFFS_FAIL;
 143
 144
 145
 146
 147
 148         for(i=fail=0; i <nBlocks; i++)
 149         {
 150
 151                 nandemul_Block *blk;
 152
 153                 if(!(blk = ned.block[i] = YMALLOC(sizeof(nandemul_Block))))
 154                 {
 155                  fail = 1;
 156                 }
 157                 else
 158                 {
 159                         for(j = 0; j < PAGES_PER_BLOCK; j++)
 160                         {
 161                                 if((blk->page[j] = YMALLOC(sizeof(nandemul_Page))) == 0)
 162                                 {
 163                                         fail = 1;
 164                                 }
 165                         }
 166                         nandemul_ReallyEraseBlock(i);
 167                         ned.block[i]->damaged = 0;
 168                         nAllocated++;
 169                 }
 170         }
 171
 172         if(fail)
 173         {
 174                 //Todo thump pages
 175
 176                 for(i = 0; i < nAllocated; i++)
 177                 {
 178                         YFREE(ned.block[i]);
 179                 }
 180                 YFREE(ned.block);
 181
 182                 T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
 183                    nAllocated/64,sizeInMB));
 184                 return 0;
 185         }
 186
 187         ned.nBlocks = nBlocks;
 188
 189         initialised = 1;
 190
 191         return 1;
 192 }
 193
 194 int nandemul2k_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, const yaffs_ExtendedTags *tags)
 195 {
 196         int blk;
 197         int pg;
 198         int i;
 199
 200         __u8 *x;
 201
 202
 203         blk = chunkInNAND/PAGES_PER_BLOCK;
 204         pg = chunkInNAND%PAGES_PER_BLOCK;
 205
 206
 207         if(data)
 208         {
 209                 x = ned.block[blk]->page[pg]->data;
 210
 211                 for(i = 0; i < PAGE_DATA_SIZE; i++)
 212                 {
 213                         x[i] &=data[i];
 214                 }
 215
 216                 ned.block[blk]->page[pg]->empty = 0;
 217         }
 218
 219
 220         if(tags)
 221         {
 222                 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
 223
 224                 yaffs_PackTags2(dev,(yaffs_PackedTags2 *)x,tags);
 225
 226         }
 227
 228         if(tags || data)
 229         {
 230                 nandemul_yield(1);
 231         }
 232
 233         return YAFFS_OK;
 234 }
 235
 236
 237 int nandemul2k_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
 238 {
 239         int blk;
 240         int pg;
 241
 242         __u8 *x;
 243
 244
 245
 246         blk = chunkInNAND/PAGES_PER_BLOCK;
 247         pg = chunkInNAND%PAGES_PER_BLOCK;
 248
 249
 250         if(data)
 251         {
 252                 memcpy(data,ned.block[blk]->page[pg]->data,PAGE_DATA_SIZE);
 253         }
 254
 255
 256         if(tags)
 257         {
 258                 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
 259
 260                 yaffs_UnpackTags2(dev,tags,(yaffs_PackedTags2 *)x);
 261         }
 262
 263         return YAFFS_OK;
 264 }
 265
 266
 267 static int nandemul2k_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
 268 {
 269         int blk;
 270         int pg;
 271         int i;
 272
 273
 274
 275         blk = chunkInNAND/PAGES_PER_BLOCK;
 276         pg = chunkInNAND%PAGES_PER_BLOCK;
 277
 278
 279         for(i = 0; i < PAGE_TOTAL_SIZE; i++)
 280         {
 281                 if(ned.block[blk]->page[pg]->data[i] != 0xFF)
 282                 {
 283                         return YAFFS_FAIL;
 284                 }
 285         }
 286
 287         return YAFFS_OK;
 288
 289 }
 290
 291 int nandemul2k_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
 292 {
 293
 294
 295         if(blockNumber < 0 || blockNumber >= ned.nBlocks)
 296         {
 297                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
 298         }
 299         else if(ned.block[blockNumber]->damaged)
 300         {
 301                 T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));
 302         }
 303         else
 304         {
 305                 nandemul_ReallyEraseBlock(blockNumber);
 306         }
 307
 308         return YAFFS_OK;
 309 }
 310
 311 int nandemul2k_InitialiseNAND(yaffs_Device *dev)
 312 {
 313         CheckInit();
 314         return YAFFS_OK;
 315 }
 316
 317 int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
 318 {
 319
 320         __u8 *x;
 321
 322         x = &ned.block[blockNo]->page[0]->data[PAGE_DATA_SIZE];
 323
 324         memset(x,0,sizeof(yaffs_PackedTags2));
 325
 326
 327         return YAFFS_OK;
 328
 329 }
 330
 331 int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, __u32  *sequenceNumber)
 332 {
 333         yaffs_ExtendedTags tags;
 334         int chunkNo;
 335
 336         *sequenceNumber = 0;
 337
 338         chunkNo = blockNo * dev->nChunksPerBlock;
 339
 340         nandemul2k_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
 341         if(tags.blockBad)
 342         {
 343                 *state = YAFFS_BLOCK_STATE_DEAD;
 344         }
 345         else if(!tags.chunkUsed)
 346         {
 347                 *state = YAFFS_BLOCK_STATE_EMPTY;
 348         }
 349         else if(tags.chunkUsed)
 350         {
 351                 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
 352                 *sequenceNumber = tags.sequenceNumber;
 353         }
 354         return YAFFS_OK;
 355 }
 356
 357 int nandemul2k_GetBytesPerChunk(void) { return PAGE_DATA_SIZE;}
 358
 359 int nandemul2k_GetChunksPerBlock(void) { return PAGES_PER_BLOCK; }
 360 int nandemul2k_GetNumberOfBlocks(void) {return nandemul2k_CalcNBlocks();}
 361
 362
 363 #endif //YAFFS_RAM_ENABLED
 364