2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
4 * Copyright (C) 2002-2007 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
7 * Created by Charles Manning <charles@aleph1.co.uk>
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.
15 * yaffs_ramem2k.c: RAM emulation in-kernel for 2K pages (YAFFS2)
19 const char *yaffs_ramem2k_c_version = "$Id: yaffs_ramem2k.c,v 1.6 2010-01-11 04:06:47 charles Exp $";
22 #define CONFIG_YAFFS_RAM_ENABLED
24 #include <linux/config.h>
27 #ifdef CONFIG_YAFFS_RAM_ENABLED
30 #include "yaffs_trace.h"
32 #include "yaffs_nandemul2k.h"
33 #include "yaffs_guts.h"
34 #include "yaffsinterface.h"
35 #include "devextras.h"
36 #include "yaffs_packedtags2.h"
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)
47 #define EM_SIZE_IN_BYTES (EM_SIZE_IN_MEG * (1<<20))
49 #define PAGE_TOTAL_SIZE (PAGE_DATA_SIZE+PAGE_SPARE_SIZE)
51 #define BLOCK_TOTAL_SIZE (PAGES_PER_BLOCK * PAGE_TOTAL_SIZE)
53 #define BLOCKS_PER_MEG ((1<<20)/(PAGES_PER_BLOCK * PAGE_DATA_SIZE))
58 __u8 data[PAGE_TOTAL_SIZE]; // Data + spare
59 int empty; // is this empty?
65 nandemul_Page *page[PAGES_PER_BLOCK];
73 nandemul_Block**block;
77 static nandemul_Device ned;
79 static int sizeInMB = EM_SIZE_IN_MEG;
82 static void nandemul_yield(int n)
85 if(n > 0) schedule_timeout(n);
91 static void nandemul_ReallyEraseBlock(int blockNumber)
97 if(blockNumber < 0 || blockNumber >= ned.nBlocks)
102 blk = ned.block[blockNumber];
104 for(i = 0; i < PAGES_PER_BLOCK; i++)
106 memset(blk->page[i],0xff,sizeof(nandemul_Page));
107 blk->page[i]->empty = 1;
113 static int nandemul2k_CalcNBlocks(void)
115 return EM_SIZE_IN_MEG * BLOCKS_PER_MEG;
120 static int CheckInit(void)
122 static int initialised = 0;
137 ned.nBlocks = nBlocks = nandemul2k_CalcNBlocks();
140 ned.block = YMALLOC(sizeof(nandemul_Block*) * nBlocks );
142 if(!ned.block) return YAFFS_FAIL;
148 for(i=fail=0; i <nBlocks; i++)
153 if(!(blk = ned.block[i] = YMALLOC(sizeof(nandemul_Block))))
159 for(j = 0; j < PAGES_PER_BLOCK; j++)
161 if((blk->page[j] = YMALLOC(sizeof(nandemul_Page))) == 0)
166 nandemul_ReallyEraseBlock(i);
167 ned.block[i]->damaged = 0;
176 for(i = 0; i < nAllocated; i++)
182 T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
183 nAllocated/64,sizeInMB));
187 ned.nBlocks = nBlocks;
194 int nandemul2k_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, const yaffs_ExtendedTags *tags)
203 blk = chunkInNAND/PAGES_PER_BLOCK;
204 pg = chunkInNAND%PAGES_PER_BLOCK;
209 x = ned.block[blk]->page[pg]->data;
211 for(i = 0; i < PAGE_DATA_SIZE; i++)
216 ned.block[blk]->page[pg]->empty = 0;
222 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
224 yaffs_PackTags2(dev,(yaffs_PackedTags2 *)x,tags);
237 int nandemul2k_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
246 blk = chunkInNAND/PAGES_PER_BLOCK;
247 pg = chunkInNAND%PAGES_PER_BLOCK;
252 memcpy(data,ned.block[blk]->page[pg]->data,PAGE_DATA_SIZE);
258 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
260 yaffs_UnpackTags2(dev,tags,(yaffs_PackedTags2 *)x);
267 static int nandemul2k_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
275 blk = chunkInNAND/PAGES_PER_BLOCK;
276 pg = chunkInNAND%PAGES_PER_BLOCK;
279 for(i = 0; i < PAGE_TOTAL_SIZE; i++)
281 if(ned.block[blk]->page[pg]->data[i] != 0xFF)
291 int nandemul2k_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
295 if(blockNumber < 0 || blockNumber >= ned.nBlocks)
297 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
299 else if(ned.block[blockNumber]->damaged)
301 T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));
305 nandemul_ReallyEraseBlock(blockNumber);
311 int nandemul2k_InitialiseNAND(yaffs_Device *dev)
317 int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
322 x = &ned.block[blockNo]->page[0]->data[PAGE_DATA_SIZE];
324 memset(x,0,sizeof(yaffs_PackedTags2));
331 int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, __u32 *sequenceNumber)
333 yaffs_ExtendedTags tags;
338 chunkNo = blockNo * dev->nChunksPerBlock;
340 nandemul2k_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
343 *state = YAFFS_BLOCK_STATE_DEAD;
345 else if(!tags.chunkUsed)
347 *state = YAFFS_BLOCK_STATE_EMPTY;
349 else if(tags.chunkUsed)
351 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
352 *sequenceNumber = tags.sequenceNumber;
357 int nandemul2k_GetBytesPerChunk(void) { return PAGE_DATA_SIZE;}
359 int nandemul2k_GetChunksPerBlock(void) { return PAGES_PER_BLOCK; }
360 int nandemul2k_GetNumberOfBlocks(void) {return nandemul2k_CalcNBlocks();}
363 #endif //YAFFS_RAM_ENABLED