805 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			805 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-or-later
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| /*
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|  * Linux driver for NAND Flash Translation Layer
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|  *
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|  * Copyright © 1999 Machine Vision Holdings, Inc.
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|  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
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|  */
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| 
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| #define PRERELEASE
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| 
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| #include <linux/kernel.h>
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| #include <linux/module.h>
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| #include <asm/errno.h>
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| #include <asm/io.h>
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| #include <linux/uaccess.h>
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| #include <linux/delay.h>
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| #include <linux/slab.h>
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| #include <linux/init.h>
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| #include <linux/hdreg.h>
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| #include <linux/blkdev.h>
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| 
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| #include <linux/kmod.h>
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| #include <linux/mtd/mtd.h>
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| #include <linux/mtd/rawnand.h>
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| #include <linux/mtd/nftl.h>
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| #include <linux/mtd/blktrans.h>
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| 
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| /* maximum number of loops while examining next block, to have a
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|    chance to detect consistency problems (they should never happen
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|    because of the checks done in the mounting */
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| 
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| #define MAX_LOOPS 10000
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| 
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| 
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| static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
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| {
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| 	struct NFTLrecord *nftl;
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| 	unsigned long temp;
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| 
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| 	if (!mtd_type_is_nand(mtd) || mtd->size > UINT_MAX)
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| 		return;
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| 	/* OK, this is moderately ugly.  But probably safe.  Alternatives? */
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| 	if (memcmp(mtd->name, "DiskOnChip", 10))
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| 		return;
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| 
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| 	pr_debug("NFTL: add_mtd for %s\n", mtd->name);
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| 
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| 	nftl = kzalloc(sizeof(struct NFTLrecord), GFP_KERNEL);
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| 
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| 	if (!nftl)
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| 		return;
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| 
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| 	nftl->mbd.mtd = mtd;
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| 	nftl->mbd.devnum = -1;
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| 
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| 	nftl->mbd.tr = tr;
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| 
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|         if (NFTL_mount(nftl) < 0) {
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| 		printk(KERN_WARNING "NFTL: could not mount device\n");
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| 		kfree(nftl);
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| 		return;
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|         }
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| 
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| 	/* OK, it's a new one. Set up all the data structures. */
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| 
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| 	/* Calculate geometry */
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| 	nftl->cylinders = 1024;
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| 	nftl->heads = 16;
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| 
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| 	temp = nftl->cylinders * nftl->heads;
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| 	nftl->sectors = nftl->mbd.size / temp;
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| 	if (nftl->mbd.size % temp) {
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| 		nftl->sectors++;
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| 		temp = nftl->cylinders * nftl->sectors;
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| 		nftl->heads = nftl->mbd.size / temp;
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| 
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| 		if (nftl->mbd.size % temp) {
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| 			nftl->heads++;
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| 			temp = nftl->heads * nftl->sectors;
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| 			nftl->cylinders = nftl->mbd.size / temp;
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| 		}
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| 	}
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| 
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| 	if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) {
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| 		/*
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| 		  Oh no we don't have
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| 		   mbd.size == heads * cylinders * sectors
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| 		*/
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| 		printk(KERN_WARNING "NFTL: cannot calculate a geometry to "
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| 		       "match size of 0x%lx.\n", nftl->mbd.size);
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| 		printk(KERN_WARNING "NFTL: using C:%d H:%d S:%d "
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| 			"(== 0x%lx sects)\n",
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| 			nftl->cylinders, nftl->heads , nftl->sectors,
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| 			(long)nftl->cylinders * (long)nftl->heads *
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| 			(long)nftl->sectors );
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| 	}
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| 
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| 	if (add_mtd_blktrans_dev(&nftl->mbd)) {
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| 		kfree(nftl->ReplUnitTable);
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| 		kfree(nftl->EUNtable);
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| 		kfree(nftl);
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| 		return;
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| 	}
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| #ifdef PSYCHO_DEBUG
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| 	printk(KERN_INFO "NFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a');
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| #endif
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| }
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| 
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| static void nftl_remove_dev(struct mtd_blktrans_dev *dev)
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| {
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| 	struct NFTLrecord *nftl = (void *)dev;
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| 
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| 	pr_debug("NFTL: remove_dev (i=%d)\n", dev->devnum);
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| 
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| 	del_mtd_blktrans_dev(dev);
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| 	kfree(nftl->ReplUnitTable);
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| 	kfree(nftl->EUNtable);
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| }
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| 
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| /*
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|  * Read oob data from flash
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|  */
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| int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
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| 		  size_t *retlen, uint8_t *buf)
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| {
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| 	loff_t mask = mtd->writesize - 1;
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| 	struct mtd_oob_ops ops;
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| 	int res;
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| 
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| 	ops.mode = MTD_OPS_PLACE_OOB;
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| 	ops.ooboffs = offs & mask;
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| 	ops.ooblen = len;
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| 	ops.oobbuf = buf;
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| 	ops.datbuf = NULL;
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| 
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| 	res = mtd_read_oob(mtd, offs & ~mask, &ops);
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| 	*retlen = ops.oobretlen;
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| 	return res;
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| }
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| 
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| /*
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|  * Write oob data to flash
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|  */
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| int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
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| 		   size_t *retlen, uint8_t *buf)
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| {
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| 	loff_t mask = mtd->writesize - 1;
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| 	struct mtd_oob_ops ops;
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| 	int res;
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| 
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| 	ops.mode = MTD_OPS_PLACE_OOB;
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| 	ops.ooboffs = offs & mask;
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| 	ops.ooblen = len;
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| 	ops.oobbuf = buf;
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| 	ops.datbuf = NULL;
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| 
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| 	res = mtd_write_oob(mtd, offs & ~mask, &ops);
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| 	*retlen = ops.oobretlen;
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| 	return res;
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| }
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| 
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| #ifdef CONFIG_NFTL_RW
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| 
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| /*
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|  * Write data and oob to flash
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|  */
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| static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
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| 		      size_t *retlen, uint8_t *buf, uint8_t *oob)
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| {
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| 	loff_t mask = mtd->writesize - 1;
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| 	struct mtd_oob_ops ops;
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| 	int res;
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| 
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| 	ops.mode = MTD_OPS_PLACE_OOB;
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| 	ops.ooboffs = offs & mask;
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| 	ops.ooblen = mtd->oobsize;
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| 	ops.oobbuf = oob;
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| 	ops.datbuf = buf;
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| 	ops.len = len;
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| 
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| 	res = mtd_write_oob(mtd, offs & ~mask, &ops);
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| 	*retlen = ops.retlen;
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| 	return res;
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| }
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| 
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| /* Actual NFTL access routines */
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| /* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used
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|  *	when the give Virtual Unit Chain
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|  */
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| static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate )
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| {
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| 	/* For a given Virtual Unit Chain: find or create a free block and
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| 	   add it to the chain */
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| 	/* We're passed the number of the last EUN in the chain, to save us from
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| 	   having to look it up again */
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| 	u16 pot = nftl->LastFreeEUN;
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| 	int silly = nftl->nb_blocks;
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| 
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| 	/* Normally, we force a fold to happen before we run out of free blocks completely */
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| 	if (!desperate && nftl->numfreeEUNs < 2) {
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| 		pr_debug("NFTL_findfreeblock: there are too few free EUNs\n");
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| 		return BLOCK_NIL;
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| 	}
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| 
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| 	/* Scan for a free block */
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| 	do {
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| 		if (nftl->ReplUnitTable[pot] == BLOCK_FREE) {
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| 			nftl->LastFreeEUN = pot;
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| 			nftl->numfreeEUNs--;
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| 			return pot;
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| 		}
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| 
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| 		/* This will probably point to the MediaHdr unit itself,
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| 		   right at the beginning of the partition. But that unit
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| 		   (and the backup unit too) should have the UCI set
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| 		   up so that it's not selected for overwriting */
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| 		if (++pot > nftl->lastEUN)
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| 			pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN);
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| 
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| 		if (!silly--) {
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| 			printk("Argh! No free blocks found! LastFreeEUN = %d, "
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| 			       "FirstEUN = %d\n", nftl->LastFreeEUN,
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| 			       le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN));
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| 			return BLOCK_NIL;
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| 		}
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| 	} while (pot != nftl->LastFreeEUN);
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| 
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| 	return BLOCK_NIL;
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| }
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| 
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| static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock )
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| {
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| 	struct mtd_info *mtd = nftl->mbd.mtd;
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| 	u16 BlockMap[MAX_SECTORS_PER_UNIT];
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| 	unsigned char BlockLastState[MAX_SECTORS_PER_UNIT];
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| 	unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT];
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| 	unsigned int thisEUN;
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| 	int block;
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| 	int silly;
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| 	unsigned int targetEUN;
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| 	struct nftl_oob oob;
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| 	int inplace = 1;
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| 	size_t retlen;
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| 
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| 	memset(BlockMap, 0xff, sizeof(BlockMap));
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| 	memset(BlockFreeFound, 0, sizeof(BlockFreeFound));
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| 
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| 	thisEUN = nftl->EUNtable[thisVUC];
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| 
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| 	if (thisEUN == BLOCK_NIL) {
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| 		printk(KERN_WARNING "Trying to fold non-existent "
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| 		       "Virtual Unit Chain %d!\n", thisVUC);
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| 		return BLOCK_NIL;
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| 	}
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| 
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| 	/* Scan to find the Erase Unit which holds the actual data for each
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| 	   512-byte block within the Chain.
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| 	*/
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| 	silly = MAX_LOOPS;
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| 	targetEUN = BLOCK_NIL;
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| 	while (thisEUN <= nftl->lastEUN ) {
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| 		unsigned int status, foldmark;
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| 
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| 		targetEUN = thisEUN;
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| 		for (block = 0; block < nftl->EraseSize / 512; block ++) {
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| 			nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) +
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| 				      (block * 512), 16 , &retlen,
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| 				      (char *)&oob);
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| 			if (block == 2) {
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| 				foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1;
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| 				if (foldmark == FOLD_MARK_IN_PROGRESS) {
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| 					pr_debug("Write Inhibited on EUN %d\n", thisEUN);
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| 					inplace = 0;
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| 				} else {
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| 					/* There's no other reason not to do inplace,
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| 					   except ones that come later. So we don't need
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| 					   to preserve inplace */
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| 					inplace = 1;
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| 				}
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| 			}
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| 			status = oob.b.Status | oob.b.Status1;
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| 			BlockLastState[block] = status;
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| 
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| 			switch(status) {
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| 			case SECTOR_FREE:
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| 				BlockFreeFound[block] = 1;
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| 				break;
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| 
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| 			case SECTOR_USED:
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| 				if (!BlockFreeFound[block])
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| 					BlockMap[block] = thisEUN;
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| 				else
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| 					printk(KERN_WARNING
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| 					       "SECTOR_USED found after SECTOR_FREE "
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| 					       "in Virtual Unit Chain %d for block %d\n",
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| 					       thisVUC, block);
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| 				break;
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| 			case SECTOR_DELETED:
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| 				if (!BlockFreeFound[block])
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| 					BlockMap[block] = BLOCK_NIL;
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| 				else
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| 					printk(KERN_WARNING
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| 					       "SECTOR_DELETED found after SECTOR_FREE "
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| 					       "in Virtual Unit Chain %d for block %d\n",
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| 					       thisVUC, block);
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| 				break;
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| 
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| 			case SECTOR_IGNORE:
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| 				break;
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| 			default:
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| 				printk("Unknown status for block %d in EUN %d: %x\n",
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| 				       block, thisEUN, status);
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| 			}
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| 		}
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| 
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| 		if (!silly--) {
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| 			printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n",
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| 			       thisVUC);
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| 			return BLOCK_NIL;
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| 		}
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| 
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| 		thisEUN = nftl->ReplUnitTable[thisEUN];
 | |
| 	}
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| 
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| 	if (inplace) {
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| 		/* We're being asked to be a fold-in-place. Check
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| 		   that all blocks which actually have data associated
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| 		   with them (i.e. BlockMap[block] != BLOCK_NIL) are
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| 		   either already present or SECTOR_FREE in the target
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| 		   block. If not, we're going to have to fold out-of-place
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| 		   anyway.
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| 		*/
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| 		for (block = 0; block < nftl->EraseSize / 512 ; block++) {
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| 			if (BlockLastState[block] != SECTOR_FREE &&
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| 			    BlockMap[block] != BLOCK_NIL &&
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| 			    BlockMap[block] != targetEUN) {
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| 				pr_debug("Setting inplace to 0. VUC %d, "
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| 				      "block %d was %x lastEUN, "
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| 				      "and is in EUN %d (%s) %d\n",
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| 				      thisVUC, block, BlockLastState[block],
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| 				      BlockMap[block],
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| 				      BlockMap[block]== targetEUN ? "==" : "!=",
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| 				      targetEUN);
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| 				inplace = 0;
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| 				break;
 | |
| 			}
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| 		}
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| 
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| 		if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) &&
 | |
| 		    pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) &&
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| 		    BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] !=
 | |
| 		    SECTOR_FREE) {
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| 			pr_debug("Pending write not free in EUN %d. "
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| 			      "Folding out of place.\n", targetEUN);
 | |
| 			inplace = 0;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	if (!inplace) {
 | |
| 		pr_debug("Cannot fold Virtual Unit Chain %d in place. "
 | |
| 		      "Trying out-of-place\n", thisVUC);
 | |
| 		/* We need to find a targetEUN to fold into. */
 | |
| 		targetEUN = NFTL_findfreeblock(nftl, 1);
 | |
| 		if (targetEUN == BLOCK_NIL) {
 | |
| 			/* Ouch. Now we're screwed. We need to do a
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| 			   fold-in-place of another chain to make room
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| 			   for this one. We need a better way of selecting
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| 			   which chain to fold, because makefreeblock will
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| 			   only ask us to fold the same one again.
 | |
| 			*/
 | |
| 			printk(KERN_WARNING
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| 			       "NFTL_findfreeblock(desperate) returns 0xffff.\n");
 | |
| 			return BLOCK_NIL;
 | |
| 		}
 | |
| 	} else {
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| 		/* We put a fold mark in the chain we are folding only if we
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|                fold in place to help the mount check code. If we do not fold in
 | |
|                place, it is possible to find the valid chain by selecting the
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|                longer one */
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| 		oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS);
 | |
| 		oob.u.c.unused = 0xffffffff;
 | |
| 		nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 2 * 512 + 8,
 | |
| 			       8, &retlen, (char *)&oob.u);
 | |
| 	}
 | |
| 
 | |
| 	/* OK. We now know the location of every block in the Virtual Unit Chain,
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| 	   and the Erase Unit into which we are supposed to be copying.
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| 	   Go for it.
 | |
| 	*/
 | |
| 	pr_debug("Folding chain %d into unit %d\n", thisVUC, targetEUN);
 | |
| 	for (block = 0; block < nftl->EraseSize / 512 ; block++) {
 | |
| 		unsigned char movebuf[512];
 | |
| 		int ret;
 | |
| 
 | |
| 		/* If it's in the target EUN already, or if it's pending write, do nothing */
 | |
| 		if (BlockMap[block] == targetEUN ||
 | |
| 		    (pendingblock == (thisVUC * (nftl->EraseSize / 512) + block))) {
 | |
| 			continue;
 | |
| 		}
 | |
| 
 | |
| 		/* copy only in non free block (free blocks can only
 | |
|                    happen in case of media errors or deleted blocks) */
 | |
| 		if (BlockMap[block] == BLOCK_NIL)
 | |
| 			continue;
 | |
| 
 | |
| 		ret = mtd_read(mtd,
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| 			       (nftl->EraseSize * BlockMap[block]) + (block * 512),
 | |
| 			       512,
 | |
| 			       &retlen,
 | |
| 			       movebuf);
 | |
| 		if (ret < 0 && !mtd_is_bitflip(ret)) {
 | |
| 			ret = mtd_read(mtd,
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| 				       (nftl->EraseSize * BlockMap[block]) + (block * 512),
 | |
| 				       512,
 | |
| 				       &retlen,
 | |
| 				       movebuf);
 | |
| 			if (ret != -EIO)
 | |
| 				printk("Error went away on retry.\n");
 | |
| 		}
 | |
| 		memset(&oob, 0xff, sizeof(struct nftl_oob));
 | |
| 		oob.b.Status = oob.b.Status1 = SECTOR_USED;
 | |
| 
 | |
| 		nftl_write(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) +
 | |
| 			   (block * 512), 512, &retlen, movebuf, (char *)&oob);
 | |
| 	}
 | |
| 
 | |
| 	/* add the header so that it is now a valid chain */
 | |
| 	oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC);
 | |
| 	oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = BLOCK_NIL;
 | |
| 
 | |
| 	nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8,
 | |
| 		       8, &retlen, (char *)&oob.u);
 | |
| 
 | |
| 	/* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */
 | |
| 
 | |
| 	/* At this point, we have two different chains for this Virtual Unit, and no way to tell
 | |
| 	   them apart. If we crash now, we get confused. However, both contain the same data, so we
 | |
| 	   shouldn't actually lose data in this case. It's just that when we load up on a medium which
 | |
| 	   has duplicate chains, we need to free one of the chains because it's not necessary any more.
 | |
| 	*/
 | |
| 	thisEUN = nftl->EUNtable[thisVUC];
 | |
| 	pr_debug("Want to erase\n");
 | |
| 
 | |
| 	/* For each block in the old chain (except the targetEUN of course),
 | |
| 	   free it and make it available for future use */
 | |
| 	while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) {
 | |
| 		unsigned int EUNtmp;
 | |
| 
 | |
| 		EUNtmp = nftl->ReplUnitTable[thisEUN];
 | |
| 
 | |
| 		if (NFTL_formatblock(nftl, thisEUN) < 0) {
 | |
| 			/* could not erase : mark block as reserved
 | |
| 			 */
 | |
| 			nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED;
 | |
| 		} else {
 | |
| 			/* correctly erased : mark it as free */
 | |
| 			nftl->ReplUnitTable[thisEUN] = BLOCK_FREE;
 | |
| 			nftl->numfreeEUNs++;
 | |
| 		}
 | |
| 		thisEUN = EUNtmp;
 | |
| 	}
 | |
| 
 | |
| 	/* Make this the new start of chain for thisVUC */
 | |
| 	nftl->ReplUnitTable[targetEUN] = BLOCK_NIL;
 | |
| 	nftl->EUNtable[thisVUC] = targetEUN;
 | |
| 
 | |
| 	return targetEUN;
 | |
| }
 | |
| 
 | |
| static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock)
 | |
| {
 | |
| 	/* This is the part that needs some cleverness applied.
 | |
| 	   For now, I'm doing the minimum applicable to actually
 | |
| 	   get the thing to work.
 | |
| 	   Wear-levelling and other clever stuff needs to be implemented
 | |
| 	   and we also need to do some assessment of the results when
 | |
| 	   the system loses power half-way through the routine.
 | |
| 	*/
 | |
| 	u16 LongestChain = 0;
 | |
| 	u16 ChainLength = 0, thislen;
 | |
| 	u16 chain, EUN;
 | |
| 
 | |
| 	for (chain = 0; chain < le32_to_cpu(nftl->MediaHdr.FormattedSize) / nftl->EraseSize; chain++) {
 | |
| 		EUN = nftl->EUNtable[chain];
 | |
| 		thislen = 0;
 | |
| 
 | |
| 		while (EUN <= nftl->lastEUN) {
 | |
| 			thislen++;
 | |
| 			//printk("VUC %d reaches len %d with EUN %d\n", chain, thislen, EUN);
 | |
| 			EUN = nftl->ReplUnitTable[EUN] & 0x7fff;
 | |
| 			if (thislen > 0xff00) {
 | |
| 				printk("Endless loop in Virtual Chain %d: Unit %x\n",
 | |
| 				       chain, EUN);
 | |
| 			}
 | |
| 			if (thislen > 0xff10) {
 | |
| 				/* Actually, don't return failure. Just ignore this chain and
 | |
| 				   get on with it. */
 | |
| 				thislen = 0;
 | |
| 				break;
 | |
| 			}
 | |
| 		}
 | |
| 
 | |
| 		if (thislen > ChainLength) {
 | |
| 			//printk("New longest chain is %d with length %d\n", chain, thislen);
 | |
| 			ChainLength = thislen;
 | |
| 			LongestChain = chain;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	if (ChainLength < 2) {
 | |
| 		printk(KERN_WARNING "No Virtual Unit Chains available for folding. "
 | |
| 		       "Failing request\n");
 | |
| 		return BLOCK_NIL;
 | |
| 	}
 | |
| 
 | |
| 	return NFTL_foldchain (nftl, LongestChain, pendingblock);
 | |
| }
 | |
| 
 | |
| /* NFTL_findwriteunit: Return the unit number into which we can write
 | |
|                        for this block. Make it available if it isn't already
 | |
| */
 | |
| static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block)
 | |
| {
 | |
| 	u16 lastEUN;
 | |
| 	u16 thisVUC = block / (nftl->EraseSize / 512);
 | |
| 	struct mtd_info *mtd = nftl->mbd.mtd;
 | |
| 	unsigned int writeEUN;
 | |
| 	unsigned long blockofs = (block * 512) & (nftl->EraseSize -1);
 | |
| 	size_t retlen;
 | |
| 	int silly, silly2 = 3;
 | |
| 	struct nftl_oob oob;
 | |
| 
 | |
| 	do {
 | |
| 		/* Scan the media to find a unit in the VUC which has
 | |
| 		   a free space for the block in question.
 | |
| 		*/
 | |
| 
 | |
| 		/* This condition catches the 0x[7f]fff cases, as well as
 | |
| 		   being a sanity check for past-end-of-media access
 | |
| 		*/
 | |
| 		lastEUN = BLOCK_NIL;
 | |
| 		writeEUN = nftl->EUNtable[thisVUC];
 | |
| 		silly = MAX_LOOPS;
 | |
| 		while (writeEUN <= nftl->lastEUN) {
 | |
| 			struct nftl_bci bci;
 | |
| 			size_t retlen;
 | |
| 			unsigned int status;
 | |
| 
 | |
| 			lastEUN = writeEUN;
 | |
| 
 | |
| 			nftl_read_oob(mtd,
 | |
| 				      (writeEUN * nftl->EraseSize) + blockofs,
 | |
| 				      8, &retlen, (char *)&bci);
 | |
| 
 | |
| 			pr_debug("Status of block %d in EUN %d is %x\n",
 | |
| 			      block , writeEUN, le16_to_cpu(bci.Status));
 | |
| 
 | |
| 			status = bci.Status | bci.Status1;
 | |
| 			switch(status) {
 | |
| 			case SECTOR_FREE:
 | |
| 				return writeEUN;
 | |
| 
 | |
| 			case SECTOR_DELETED:
 | |
| 			case SECTOR_USED:
 | |
| 			case SECTOR_IGNORE:
 | |
| 				break;
 | |
| 			default:
 | |
| 				// Invalid block. Don't use it any more. Must implement.
 | |
| 				break;
 | |
| 			}
 | |
| 
 | |
| 			if (!silly--) {
 | |
| 				printk(KERN_WARNING
 | |
| 				       "Infinite loop in Virtual Unit Chain 0x%x\n",
 | |
| 				       thisVUC);
 | |
| 				return BLOCK_NIL;
 | |
| 			}
 | |
| 
 | |
| 			/* Skip to next block in chain */
 | |
| 			writeEUN = nftl->ReplUnitTable[writeEUN];
 | |
| 		}
 | |
| 
 | |
| 		/* OK. We didn't find one in the existing chain, or there
 | |
| 		   is no existing chain. */
 | |
| 
 | |
| 		/* Try to find an already-free block */
 | |
| 		writeEUN = NFTL_findfreeblock(nftl, 0);
 | |
| 
 | |
| 		if (writeEUN == BLOCK_NIL) {
 | |
| 			/* That didn't work - there were no free blocks just
 | |
| 			   waiting to be picked up. We're going to have to fold
 | |
| 			   a chain to make room.
 | |
| 			*/
 | |
| 
 | |
| 			/* First remember the start of this chain */
 | |
| 			//u16 startEUN = nftl->EUNtable[thisVUC];
 | |
| 
 | |
| 			//printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC);
 | |
| 			writeEUN = NFTL_makefreeblock(nftl, BLOCK_NIL);
 | |
| 
 | |
| 			if (writeEUN == BLOCK_NIL) {
 | |
| 				/* OK, we accept that the above comment is
 | |
| 				   lying - there may have been free blocks
 | |
| 				   last time we called NFTL_findfreeblock(),
 | |
| 				   but they are reserved for when we're
 | |
| 				   desperate. Well, now we're desperate.
 | |
| 				*/
 | |
| 				pr_debug("Using desperate==1 to find free EUN to accommodate write to VUC %d\n", thisVUC);
 | |
| 				writeEUN = NFTL_findfreeblock(nftl, 1);
 | |
| 			}
 | |
| 			if (writeEUN == BLOCK_NIL) {
 | |
| 				/* Ouch. This should never happen - we should
 | |
| 				   always be able to make some room somehow.
 | |
| 				   If we get here, we've allocated more storage
 | |
| 				   space than actual media, or our makefreeblock
 | |
| 				   routine is missing something.
 | |
| 				*/
 | |
| 				printk(KERN_WARNING "Cannot make free space.\n");
 | |
| 				return BLOCK_NIL;
 | |
| 			}
 | |
| 			//printk("Restarting scan\n");
 | |
| 			continue;
 | |
| 		}
 | |
| 
 | |
| 		/* We've found a free block. Insert it into the chain. */
 | |
| 
 | |
| 		if (lastEUN != BLOCK_NIL) {
 | |
| 			thisVUC |= 0x8000; /* It's a replacement block */
 | |
| 		} else {
 | |
| 			/* The first block in a new chain */
 | |
| 			nftl->EUNtable[thisVUC] = writeEUN;
 | |
| 		}
 | |
| 
 | |
| 		/* set up the actual EUN we're writing into */
 | |
| 		/* Both in our cache... */
 | |
| 		nftl->ReplUnitTable[writeEUN] = BLOCK_NIL;
 | |
| 
 | |
| 		/* ... and on the flash itself */
 | |
| 		nftl_read_oob(mtd, writeEUN * nftl->EraseSize + 8, 8,
 | |
| 			      &retlen, (char *)&oob.u);
 | |
| 
 | |
| 		oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC);
 | |
| 
 | |
| 		nftl_write_oob(mtd, writeEUN * nftl->EraseSize + 8, 8,
 | |
| 			       &retlen, (char *)&oob.u);
 | |
| 
 | |
| 		/* we link the new block to the chain only after the
 | |
|                    block is ready. It avoids the case where the chain
 | |
|                    could point to a free block */
 | |
| 		if (lastEUN != BLOCK_NIL) {
 | |
| 			/* Both in our cache... */
 | |
| 			nftl->ReplUnitTable[lastEUN] = writeEUN;
 | |
| 			/* ... and on the flash itself */
 | |
| 			nftl_read_oob(mtd, (lastEUN * nftl->EraseSize) + 8,
 | |
| 				      8, &retlen, (char *)&oob.u);
 | |
| 
 | |
| 			oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum
 | |
| 				= cpu_to_le16(writeEUN);
 | |
| 
 | |
| 			nftl_write_oob(mtd, (lastEUN * nftl->EraseSize) + 8,
 | |
| 				       8, &retlen, (char *)&oob.u);
 | |
| 		}
 | |
| 
 | |
| 		return writeEUN;
 | |
| 
 | |
| 	} while (silly2--);
 | |
| 
 | |
| 	printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n",
 | |
| 	       thisVUC);
 | |
| 	return BLOCK_NIL;
 | |
| }
 | |
| 
 | |
| static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block,
 | |
| 			   char *buffer)
 | |
| {
 | |
| 	struct NFTLrecord *nftl = (void *)mbd;
 | |
| 	u16 writeEUN;
 | |
| 	unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1);
 | |
| 	size_t retlen;
 | |
| 	struct nftl_oob oob;
 | |
| 
 | |
| 	writeEUN = NFTL_findwriteunit(nftl, block);
 | |
| 
 | |
| 	if (writeEUN == BLOCK_NIL) {
 | |
| 		printk(KERN_WARNING
 | |
| 		       "NFTL_writeblock(): Cannot find block to write to\n");
 | |
| 		/* If we _still_ haven't got a block to use, we're screwed */
 | |
| 		return 1;
 | |
| 	}
 | |
| 
 | |
| 	memset(&oob, 0xff, sizeof(struct nftl_oob));
 | |
| 	oob.b.Status = oob.b.Status1 = SECTOR_USED;
 | |
| 
 | |
| 	nftl_write(nftl->mbd.mtd, (writeEUN * nftl->EraseSize) + blockofs,
 | |
| 		   512, &retlen, (char *)buffer, (char *)&oob);
 | |
| 	return 0;
 | |
| }
 | |
| #endif /* CONFIG_NFTL_RW */
 | |
| 
 | |
| static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block,
 | |
| 			  char *buffer)
 | |
| {
 | |
| 	struct NFTLrecord *nftl = (void *)mbd;
 | |
| 	struct mtd_info *mtd = nftl->mbd.mtd;
 | |
| 	u16 lastgoodEUN;
 | |
| 	u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)];
 | |
| 	unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1);
 | |
| 	unsigned int status;
 | |
| 	int silly = MAX_LOOPS;
 | |
| 	size_t retlen;
 | |
| 	struct nftl_bci bci;
 | |
| 
 | |
| 	lastgoodEUN = BLOCK_NIL;
 | |
| 
 | |
| 	if (thisEUN != BLOCK_NIL) {
 | |
| 		while (thisEUN < nftl->nb_blocks) {
 | |
| 			if (nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) +
 | |
| 					  blockofs, 8, &retlen,
 | |
| 					  (char *)&bci) < 0)
 | |
| 				status = SECTOR_IGNORE;
 | |
| 			else
 | |
| 				status = bci.Status | bci.Status1;
 | |
| 
 | |
| 			switch (status) {
 | |
| 			case SECTOR_FREE:
 | |
| 				/* no modification of a sector should follow a free sector */
 | |
| 				goto the_end;
 | |
| 			case SECTOR_DELETED:
 | |
| 				lastgoodEUN = BLOCK_NIL;
 | |
| 				break;
 | |
| 			case SECTOR_USED:
 | |
| 				lastgoodEUN = thisEUN;
 | |
| 				break;
 | |
| 			case SECTOR_IGNORE:
 | |
| 				break;
 | |
| 			default:
 | |
| 				printk("Unknown status for block %ld in EUN %d: %x\n",
 | |
| 				       block, thisEUN, status);
 | |
| 				break;
 | |
| 			}
 | |
| 
 | |
| 			if (!silly--) {
 | |
| 				printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n",
 | |
| 				       block / (nftl->EraseSize / 512));
 | |
| 				return 1;
 | |
| 			}
 | |
| 			thisEUN = nftl->ReplUnitTable[thisEUN];
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
|  the_end:
 | |
| 	if (lastgoodEUN == BLOCK_NIL) {
 | |
| 		/* the requested block is not on the media, return all 0x00 */
 | |
| 		memset(buffer, 0, 512);
 | |
| 	} else {
 | |
| 		loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs;
 | |
| 		size_t retlen;
 | |
| 		int res = mtd_read(mtd, ptr, 512, &retlen, buffer);
 | |
| 
 | |
| 		if (res < 0 && !mtd_is_bitflip(res))
 | |
| 			return -EIO;
 | |
| 	}
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static int nftl_getgeo(struct mtd_blktrans_dev *dev,  struct hd_geometry *geo)
 | |
| {
 | |
| 	struct NFTLrecord *nftl = (void *)dev;
 | |
| 
 | |
| 	geo->heads = nftl->heads;
 | |
| 	geo->sectors = nftl->sectors;
 | |
| 	geo->cylinders = nftl->cylinders;
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| /****************************************************************************
 | |
|  *
 | |
|  * Module stuff
 | |
|  *
 | |
|  ****************************************************************************/
 | |
| 
 | |
| 
 | |
| static struct mtd_blktrans_ops nftl_tr = {
 | |
| 	.name		= "nftl",
 | |
| 	.major		= NFTL_MAJOR,
 | |
| 	.part_bits	= NFTL_PARTN_BITS,
 | |
| 	.blksize 	= 512,
 | |
| 	.getgeo		= nftl_getgeo,
 | |
| 	.readsect	= nftl_readblock,
 | |
| #ifdef CONFIG_NFTL_RW
 | |
| 	.writesect	= nftl_writeblock,
 | |
| #endif
 | |
| 	.add_mtd	= nftl_add_mtd,
 | |
| 	.remove_dev	= nftl_remove_dev,
 | |
| 	.owner		= THIS_MODULE,
 | |
| };
 | |
| 
 | |
| module_mtd_blktrans(nftl_tr);
 | |
| 
 | |
| MODULE_LICENSE("GPL");
 | |
| MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al.");
 | |
| MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium");
 | |
| MODULE_ALIAS_BLOCKDEV_MAJOR(NFTL_MAJOR);
 |