2 * YAFFS: Yet another FFS. A NAND-flash specific file system.
3 * yaffs_ramem.c NAND emulation on top of a chunk of RAM
5 * Copyright (C) 2002 Aleph One Ltd.
6 * for Toby Churchill Ltd and Brightstar Engineering
8 * Created by Charles Manning <charles@aleph1.co.uk>
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.
15 //yaffs_ramem2k.c: RAM emulation in-kernel for 2K pages (YAFFS2)
18 const char *yaffs_ramem2k_c_version = "$Id: yaffs_ramem2k.c,v 1.1 2005-08-09 01:00:37 charles Exp $";
21 #define CONFIG_YAFFS_RAM_ENABLED
23 #include <linux/config.h>
26 #ifdef CONFIG_YAFFS_RAM_ENABLED
30 #include "yaffs_nandemul2k.h"
31 #include "yaffs_guts.h"
32 #include "yaffsinterface.h"
33 #include "devextras.h"
34 #include "yaffs_packedtags2.h"
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)
45 #define EM_SIZE_IN_BYTES (EM_SIZE_IN_MEG * (1<<20))
47 #define PAGE_TOTAL_SIZE (PAGE_DATA_SIZE+PAGE_SPARE_SIZE)
49 #define BLOCK_TOTAL_SIZE (PAGES_PER_BLOCK * PAGE_TOTAL_SIZE)
51 #define BLOCKS_PER_MEG ((1<<20)/(PAGES_PER_BLOCK * PAGE_DATA_SIZE))
56 __u8 data[PAGE_TOTAL_SIZE]; // Data + spare
57 int empty; // is this empty?
63 nandemul_Page *page[PAGES_PER_BLOCK];
71 nandemul_Block**block;
75 static nandemul_Device ned;
77 static int sizeInMB = EM_SIZE_IN_MEG;
80 static void nandemul_yield(int n)
83 if(n > 0) schedule_timeout(n);
89 static void nandemul_ReallyEraseBlock(int blockNumber)
95 if(blockNumber < 0 || blockNumber >= ned.nBlocks)
100 blk = ned.block[blockNumber];
102 for(i = 0; i < PAGES_PER_BLOCK; i++)
104 memset(blk->page[i],0xff,sizeof(nandemul_Page));
105 blk->page[i]->empty = 1;
111 static int nandemul2k_CalcNBlocks(void)
113 return EM_SIZE_IN_MEG * BLOCKS_PER_MEG;
118 static int CheckInit(void)
120 static int initialised = 0;
135 ned.nBlocks = nBlocks = nandemul2k_CalcNBlocks();
138 ned.block = YMALLOC(sizeof(nandemul_Block*) * nBlocks );
140 if(!ned.block) return YAFFS_FAIL;
146 for(i=fail=0; i <nBlocks; i++)
151 if(!(blk = ned.block[i] = YMALLOC(sizeof(nandemul_Block))))
157 for(j = 0; j < PAGES_PER_BLOCK; j++)
159 if((blk->page[j] = YMALLOC(sizeof(nandemul_Page))) == 0)
164 nandemul_ReallyEraseBlock(i);
165 ned.block[i]->damaged = 0;
174 for(i = 0; i < nAllocated; i++)
180 T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",
181 nAllocated/64,sizeInMB));
185 ned.nBlocks = nBlocks;
192 int nandemul2k_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_ExtendedTags *tags)
201 blk = chunkInNAND/PAGES_PER_BLOCK;
202 pg = chunkInNAND%PAGES_PER_BLOCK;
207 x = ned.block[blk]->page[pg]->data;
209 for(i = 0; i < PAGE_DATA_SIZE; i++)
214 ned.block[blk]->page[pg]->empty = 0;
220 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
222 yaffs_PackTags2((yaffs_PackedTags2 *)x,tags);
235 int nandemul2k_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags)
244 blk = chunkInNAND/PAGES_PER_BLOCK;
245 pg = chunkInNAND%PAGES_PER_BLOCK;
250 memcpy(data,ned.block[blk]->page[pg]->data,PAGE_DATA_SIZE);
256 x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];
258 yaffs_UnpackTags2(tags,(yaffs_PackedTags2 *)x);
265 static int nandemul2k_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
273 blk = chunkInNAND/PAGES_PER_BLOCK;
274 pg = chunkInNAND%PAGES_PER_BLOCK;
277 for(i = 0; i < PAGE_TOTAL_SIZE; i++)
279 if(ned.block[blk]->page[pg]->data[i] != 0xFF)
289 int nandemul2k_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
293 if(blockNumber < 0 || blockNumber >= ned.nBlocks)
295 T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));
297 else if(ned.block[blockNumber]->damaged)
299 T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));
303 nandemul_ReallyEraseBlock(blockNumber);
309 int nandemul2k_InitialiseNAND(yaffs_Device *dev)
315 int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
320 x = &ned.block[blockNo]->page[0]->data[PAGE_DATA_SIZE];
322 memset(x,0,sizeof(yaffs_PackedTags2));
329 int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, int *sequenceNumber)
331 yaffs_ExtendedTags tags;
336 chunkNo = blockNo * dev->nChunksPerBlock;
338 nandemul2k_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);
341 *state = YAFFS_BLOCK_STATE_DEAD;
343 else if(!tags.chunkUsed)
345 *state = YAFFS_BLOCK_STATE_EMPTY;
347 else if(tags.chunkUsed)
349 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
350 *sequenceNumber = tags.sequenceNumber;
355 int nandemul2k_GetBytesPerChunk(void) { return PAGE_DATA_SIZE;}
357 int nandemul2k_GetChunksPerBlock(void) { return PAGES_PER_BLOCK; }
358 int nandemul2k_GetNumberOfBlocks(void) {return nandemul2k_CalcNBlocks();}
361 #endif //YAFFS_RAM_ENABLED