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)
21 const char *yaffs_ramem2k_c_version = "$Id: yaffs_ramem2k.c,v 1.3 2007/02/14 01:09:06 wookey Exp $";
24 #define CONFIG_YAFFS_RAM_ENABLED
26 #include <linux/config.h>
29 #ifdef CONFIG_YAFFS_RAM_ENABLED
33 #include "yaffs_nandemul2k.h"
34 #include "yaffs_guts.h"
35 #include "yaffsinterface.h"
36 #include "devextras.h"
37 #include "yaffs_packedtags2.h"
41 #define EM_SIZE_IN_MEG (32)
42 #define PAGE_DATA_SIZE (2048)
43 #define PAGE_SPARE_SIZE (64)
44 #define PAGES_PER_BLOCK (64)
48 #define EM_SIZE_IN_BYTES (EM_SIZE_IN_MEG * (1<<20))
50 #define PAGE_TOTAL_SIZE (PAGE_DATA_SIZE+PAGE_SPARE_SIZE)
52 #define BLOCK_TOTAL_SIZE (PAGES_PER_BLOCK * PAGE_TOTAL_SIZE)
54 #define BLOCKS_PER_MEG ((1<<20)/(PAGES_PER_BLOCK * PAGE_DATA_SIZE))
59 __u8 data[PAGE_TOTAL_SIZE]; // Data + spare
60 int empty; // is this empty?
66 nandemul_Page *page[PAGES_PER_BLOCK];
74 nandemul_Block**block;
78 static nandemul_Device ned;
80 static int sizeInMB = EM_SIZE_IN_MEG;
83 static void nandemul_yield(int n)
86 if(n > 0) schedule_timeout(n);
92 static void nandemul_ReallyEraseBlock(int blockNumber)
98 if(blockNumber < 0 || blockNumber >= ned.nBlocks)
103 blk = ned.block[blockNumber];
105 for(i = 0; i < PAGES_PER_BLOCK; i++)
107 memset(blk->page[i],0xff,sizeof(nandemul_Page));
108 blk->page[i]->empty = 1;
114 static int nandemul2k_CalcNBlocks(void)
116 return EM_SIZE_IN_MEG * BLOCKS_PER_MEG;
121 static int CheckInit(void)
123 static int initialised = 0;
138 ned.nBlocks = nBlocks = nandemul2k_CalcNBlocks();
141 ned.block = YMALLOC(sizeof(nandemul_Block*) * nBlocks );
143 if(!ned.block) return YAFFS_FAIL;
149 for(i=fail=0; i <nBlocks; i++)
154 if(!(blk = ned.block[i] = YMALLOC(sizeof(nandemul_Block))))
160 for(j = 0; j < PAGES_PER_BLOCK; j++)
162 if((blk->page[j] = YMALLOC(sizeof(nandemul_Page))) == 0)
167 nandemul_ReallyEraseBlock(i);
168 ned.block[i]->damaged = 0;
177 for(i = 0; i < nAllocated; i++)
183 T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
184 nAllocated/64,sizeInMB));
188 ned.nBlocks = nBlocks;
195 int nandemul2k_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
204 blk = chunkInNAND/PAGES_PER_BLOCK;
205 pg = chunkInNAND%PAGES_PER_BLOCK;
210 x = ned.block[blk]->page[pg]->data;
212 for(i = 0; i < PAGE_DATA_SIZE; i++)
217 ned.block[blk]->page[pg]->empty = 0;
223 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
225 yaffs_PackTags2((yaffs_PackedTags2 *)x,tags);
238 int nandemul2k_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
247 blk = chunkInNAND/PAGES_PER_BLOCK;
248 pg = chunkInNAND%PAGES_PER_BLOCK;
253 memcpy(data,ned.block[blk]->page[pg]->data,PAGE_DATA_SIZE);
259 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
261 yaffs_UnpackTags2(tags,(yaffs_PackedTags2 *)x);
268 static int nandemul2k_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
276 blk = chunkInNAND/PAGES_PER_BLOCK;
277 pg = chunkInNAND%PAGES_PER_BLOCK;
280 for(i = 0; i < PAGE_TOTAL_SIZE; i++)
282 if(ned.block[blk]->page[pg]->data[i] != 0xFF)
292 int nandemul2k_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
296 if(blockNumber < 0 || blockNumber >= ned.nBlocks)
298 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
300 else if(ned.block[blockNumber]->damaged)
302 T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));
306 nandemul_ReallyEraseBlock(blockNumber);
312 int nandemul2k_InitialiseNAND(yaffs_Device *dev)
318 int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
323 x = &ned.block[blockNo]->page[0]->data[PAGE_DATA_SIZE];
325 memset(x,0,sizeof(yaffs_PackedTags2));
332 int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, int *sequenceNumber)
334 yaffs_ExtendedTags tags;
339 chunkNo = blockNo * dev->nChunksPerBlock;
341 nandemul2k_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
344 *state = YAFFS_BLOCK_STATE_DEAD;
346 else if(!tags.chunkUsed)
348 *state = YAFFS_BLOCK_STATE_EMPTY;
350 else if(tags.chunkUsed)
352 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
353 *sequenceNumber = tags.sequenceNumber;
358 int nandemul2k_GetBytesPerChunk(void) { return PAGE_DATA_SIZE;}
360 int nandemul2k_GetChunksPerBlock(void) { return PAGES_PER_BLOCK; }
361 int nandemul2k_GetNumberOfBlocks(void) {return nandemul2k_CalcNBlocks();}
364 #endif //YAFFS_RAM_ENABLED