/* * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. * * Copyright (C) 2002-2007 Aleph One Ltd. *   for Toby Churchill Ltd and Brightstar Engineering * * Created by Charles Manning <charles@aleph1.co.uk> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. *//* * yaffs_ramem2k.c: RAM emulation in-kernel for 2K pages (YAFFS2) */const char *yaffs_ramem2k_c_version = "$Id: yaffs_ramem2k.c,v 1.4 2008/05/05 07:58:58 charles Exp $";#ifndef __KERNEL__#define CONFIG_YAFFS_RAM_ENABLED#else#include <linux/config.h>#endif#ifdef CONFIG_YAFFS_RAM_ENABLED#include "yportenv.h"#include "yaffs_nandemul2k.h"#include "yaffs_guts.h"#include "yaffsinterface.h"#include "devextras.h"#include "yaffs_packedtags2.h"#define EM_SIZE_IN_MEG (32)#define PAGE_DATA_SIZE  (2048)#define PAGE_SPARE_SIZE (64)#define PAGES_PER_BLOCK (64)#define EM_SIZE_IN_BYTES (EM_SIZE_IN_MEG * (1<<20))#define PAGE_TOTAL_SIZE (PAGE_DATA_SIZE+PAGE_SPARE_SIZE)#define BLOCK_TOTAL_SIZE (PAGES_PER_BLOCK * PAGE_TOTAL_SIZE)#define BLOCKS_PER_MEG ((1<<20)/(PAGES_PER_BLOCK * PAGE_DATA_SIZE))typedef struct {	__u8 data[PAGE_TOTAL_SIZE]; // Data + spare	int empty;      // is this empty?} nandemul_Page;typedef struct{	nandemul_Page *page[PAGES_PER_BLOCK];	int damaged;	} nandemul_Block;typedef struct{	nandemul_Block**block;	int nBlocks;} nandemul_Device;static nandemul_Device ned;static int sizeInMB = EM_SIZE_IN_MEG;static void nandemul_yield(int n){#ifdef __KERNEL__	if(n > 0) schedule_timeout(n);#endif}static void nandemul_ReallyEraseBlock(int blockNumber){	int i;		nandemul_Block *blk;		if(blockNumber < 0 || blockNumber >= ned.nBlocks)	{		return;	}		blk = ned.block[blockNumber];		for(i = 0; i < PAGES_PER_BLOCK; i++)	{		memset(blk->page[i],0xff,sizeof(nandemul_Page));		blk->page[i]->empty = 1;	}	nandemul_yield(2);}static int nandemul2k_CalcNBlocks(void){	return EM_SIZE_IN_MEG * BLOCKS_PER_MEG;}static int  CheckInit(void){	static int initialised = 0;		int i,j;		int fail = 0;	int nBlocks; 	int nAllocated = 0;		if(initialised) 	{		return YAFFS_OK;	}			ned.nBlocks = nBlocks = nandemul2k_CalcNBlocks();		ned.block = YMALLOC(sizeof(nandemul_Block*) * nBlocks );		if(!ned.block) return YAFFS_FAIL;						for(i=fail=0; i <nBlocks; i++)	{				nandemul_Block *blk;				if(!(blk = ned.block[i] = YMALLOC(sizeof(nandemul_Block))))		{		 fail = 1;		}  		else		{			for(j = 0; j < PAGES_PER_BLOCK; j++)			{				if((blk->page[j] = YMALLOC(sizeof(nandemul_Page))) == 0)				{					fail = 1;				}			}			nandemul_ReallyEraseBlock(i);			ned.block[i]->damaged = 0;			nAllocated++;		}	}		if(fail)	{		//Todo thump pages				for(i = 0; i < nAllocated; i++)		{			YFREE(ned.block[i]);		}		YFREE(ned.block);				T(YAFFS_TRACE_ALWAYS,("Allocation failed, could only allocate %dMB of %dMB requested.\n",		   nAllocated/64,sizeInMB));		return 0;	}		ned.nBlocks = nBlocks;		initialised = 1;		return 1;}int nandemul2k_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, const yaffs_ExtendedTags *tags){	int blk;	int pg;	int i;		__u8 *x;		blk = chunkInNAND/PAGES_PER_BLOCK;	pg = chunkInNAND%PAGES_PER_BLOCK;			if(data)	{		x = ned.block[blk]->page[pg]->data;				for(i = 0; i < PAGE_DATA_SIZE; i++)		{			x[i] &=data[i];		}		ned.block[blk]->page[pg]->empty = 0;	}			if(tags)	{		x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];				yaffs_PackTags2((yaffs_PackedTags2 *)x,tags);				}		if(tags || data)	{		nandemul_yield(1);	}	return YAFFS_OK;}int nandemul2k_ReadChunkWithTagsFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_ExtendedTags *tags){	int blk;	int pg;		__u8 *x;			blk = chunkInNAND/PAGES_PER_BLOCK;	pg = chunkInNAND%PAGES_PER_BLOCK;			if(data)	{		memcpy(data,ned.block[blk]->page[pg]->data,PAGE_DATA_SIZE);	}			if(tags)	{		x = &ned.block[blk]->page[pg]->data[PAGE_DATA_SIZE];				yaffs_UnpackTags2(tags,(yaffs_PackedTags2 *)x);	}	return YAFFS_OK;}static int nandemul2k_CheckChunkErased(yaffs_Device *dev,int chunkInNAND){	int blk;	int pg;	int i;			blk = chunkInNAND/PAGES_PER_BLOCK;	pg = chunkInNAND%PAGES_PER_BLOCK;			for(i = 0; i < PAGE_TOTAL_SIZE; i++)	{		if(ned.block[blk]->page[pg]->data[i] != 0xFF)		{			return YAFFS_FAIL;		}	}	return YAFFS_OK;}int nandemul2k_EraseBlockInNAND(yaffs_Device *dev, int blockNumber){			if(blockNumber < 0 || blockNumber >= ned.nBlocks)	{		T(YAFFS_TRACE_ALWAYS,("Attempt to erase non-existant block %d\n",blockNumber));	}	else if(ned.block[blockNumber]->damaged)	{		T(YAFFS_TRACE_ALWAYS,("Attempt to erase damaged block %d\n",blockNumber));	}	else	{		nandemul_ReallyEraseBlock(blockNumber);	}		return YAFFS_OK;}int nandemul2k_InitialiseNAND(yaffs_Device *dev){	CheckInit();	return YAFFS_OK;} int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo){		__u8 *x;		x = &ned.block[blockNo]->page[0]->data[PAGE_DATA_SIZE];		memset(x,0,sizeof(yaffs_PackedTags2));			return YAFFS_OK;	}int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo, yaffs_BlockState *state, __u32  *sequenceNumber){	yaffs_ExtendedTags tags;	int chunkNo;	*sequenceNumber = 0;		chunkNo = blockNo * dev->nChunksPerBlock;		nandemul2k_ReadChunkWithTagsFromNAND(dev,chunkNo,NULL,&tags);	if(tags.blockBad)	{		*state = YAFFS_BLOCK_STATE_DEAD;	}	else if(!tags.chunkUsed)	{		*state = YAFFS_BLOCK_STATE_EMPTY;	}	else if(tags.chunkUsed)	{		*state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;		*sequenceNumber = tags.sequenceNumber;	}	return YAFFS_OK;}int nandemul2k_GetBytesPerChunk(void) { return PAGE_DATA_SIZE;}int nandemul2k_GetChunksPerBlock(void) { return PAGES_PER_BLOCK; }int nandemul2k_GetNumberOfBlocks(void) {return nandemul2k_CalcNBlocks();}#endif //YAFFS_RAM_ENABLED