patch-2.4.6 linux/drivers/mtd/nftlcore.c
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- Lines: 1095
- Date:
Tue Jun 12 10:30:27 2001
- Orig file:
v2.4.5/linux/drivers/mtd/nftlcore.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.4.5/linux/drivers/mtd/nftlcore.c linux/drivers/mtd/nftlcore.c
@@ -0,0 +1,1094 @@
+/* Linux driver for NAND Flash Translation Layer */
+/* (c) 1999 Machine Vision Holdings, Inc. */
+/* Author: David Woodhouse <dwmw2@infradead.org> */
+/* $Id: nftlcore.c,v 1.73 2001/06/09 01:09:43 dwmw2 Exp $ */
+
+/*
+ The contents of this file are distributed under the GNU General
+ Public License version 2. The author places no additional
+ restrictions of any kind on it.
+ */
+
+#define PRERELEASE
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <linux/miscdevice.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/blkpg.h>
+
+#ifdef CONFIG_KMOD
+#include <linux/kmod.h>
+#endif
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nftl.h>
+#include <linux/mtd/compatmac.h>
+
+/* maximum number of loops while examining next block, to have a
+ chance to detect consistency problems (they should never happen
+ because of the checks done in the mounting */
+
+#define MAX_LOOPS 10000
+
+/* NFTL block device stuff */
+#define MAJOR_NR NFTL_MAJOR
+#define DEVICE_REQUEST nftl_request
+#define DEVICE_OFF(device)
+
+
+#include <linux/blk.h>
+#include <linux/hdreg.h>
+
+/* Linux-specific block device functions */
+
+/* I _HATE_ the Linux block device setup more than anything else I've ever
+ * encountered, except ...
+ */
+
+static int nftl_sizes[256];
+static int nftl_blocksizes[256];
+
+/* .. for the Linux partition table handling. */
+struct hd_struct part_table[256];
+
+#if LINUX_VERSION_CODE < 0x20328
+static void dummy_init (struct gendisk *crap)
+{}
+#endif
+
+static struct gendisk nftl_gendisk = {
+ major: MAJOR_NR,
+ major_name: "nftl",
+ minor_shift: NFTL_PARTN_BITS, /* Bits to shift to get real from partition */
+ max_p: (1<<NFTL_PARTN_BITS)-1, /* Number of partitions per real */
+#if LINUX_VERSION_CODE < 0x20328
+ max_nr: MAX_NFTLS, /* maximum number of real */
+ init: dummy_init, /* init function */
+#endif
+ part: part_table, /* hd struct */
+ sizes: nftl_sizes, /* block sizes */
+};
+
+struct NFTLrecord *NFTLs[MAX_NFTLS];
+
+static void NFTL_setup(struct mtd_info *mtd)
+{
+ int i;
+ struct NFTLrecord *nftl;
+ unsigned long temp;
+ int firstfree = -1;
+
+ DEBUG(MTD_DEBUG_LEVEL1,"NFTL_setup\n");
+
+ for (i = 0; i < MAX_NFTLS; i++) {
+ if (!NFTLs[i] && firstfree == -1)
+ firstfree = i;
+ else if (NFTLs[i] && NFTLs[i]->mtd == mtd) {
+ /* This is a Spare Media Header for an NFTL we've already found */
+ DEBUG(MTD_DEBUG_LEVEL1, "MTD already mounted as NFTL\n");
+ return;
+ }
+ }
+ if (firstfree == -1) {
+ printk(KERN_WARNING "No more NFTL slot available\n");
+ return;
+ }
+
+ nftl = kmalloc(sizeof(struct NFTLrecord), GFP_KERNEL);
+ if (!nftl) {
+ printk(KERN_WARNING "Out of memory for NFTL data structures\n");
+ return;
+ }
+
+ init_MUTEX(&nftl->mutex);
+
+ /* get physical parameters */
+ nftl->EraseSize = mtd->erasesize;
+ nftl->nb_blocks = mtd->size / mtd->erasesize;
+ nftl->mtd = mtd;
+
+ if (NFTL_mount(nftl) < 0) {
+ printk(KERN_WARNING "Could not mount NFTL device\n");
+ kfree(nftl);
+ return;
+ }
+
+ /* OK, it's a new one. Set up all the data structures. */
+#ifdef PSYCHO_DEBUG
+ printk("Found new NFTL nftl%c\n", firstfree + 'a');
+#endif
+
+ /* linux stuff */
+ nftl->usecount = 0;
+ nftl->cylinders = 1024;
+ nftl->heads = 16;
+
+ temp = nftl->cylinders * nftl->heads;
+ nftl->sectors = nftl->nr_sects / temp;
+ if (nftl->nr_sects % temp) {
+ nftl->sectors++;
+ temp = nftl->cylinders * nftl->sectors;
+ nftl->heads = nftl->nr_sects / temp;
+
+ if (nftl->nr_sects % temp) {
+ nftl->heads++;
+ temp = nftl->heads * nftl->sectors;
+ nftl->cylinders = nftl->nr_sects / temp;
+ }
+ }
+
+ if (nftl->nr_sects != nftl->heads * nftl->cylinders * nftl->sectors) {
+ printk(KERN_WARNING "Cannot calculate an NFTL geometry to "
+ "match size of 0x%lx.\n", nftl->nr_sects);
+ printk(KERN_WARNING "Using C:%d H:%d S:%d (== 0x%lx sects)\n",
+ nftl->cylinders, nftl->heads , nftl->sectors,
+ (long)nftl->cylinders * (long)nftl->heads * (long)nftl->sectors );
+
+ /* Oh no we don't have nftl->nr_sects = nftl->heads * nftl->cylinders * nftl->sectors; */
+ }
+ NFTLs[firstfree] = nftl;
+ /* Finally, set up the block device sizes */
+ nftl_sizes[firstfree * 16] = nftl->nr_sects;
+ //nftl_blocksizes[firstfree*16] = 512;
+ part_table[firstfree * 16].nr_sects = nftl->nr_sects;
+
+ nftl_gendisk.nr_real++;
+
+ /* partition check ... */
+#if LINUX_VERSION_CODE < 0x20328
+ resetup_one_dev(&nftl_gendisk, firstfree);
+#else
+ grok_partitions(&nftl_gendisk, firstfree, 1<<NFTL_PARTN_BITS, nftl->nr_sects);
+#endif
+}
+
+static void NFTL_unsetup(int i)
+{
+ struct NFTLrecord *nftl = NFTLs[i];
+
+ DEBUG(MTD_DEBUG_LEVEL1, "NFTL_unsetup %d\n", i);
+
+ NFTLs[i] = NULL;
+
+ if (nftl->ReplUnitTable)
+ kfree(nftl->ReplUnitTable);
+ if (nftl->EUNtable)
+ kfree(nftl->EUNtable);
+
+ nftl_gendisk.nr_real--;
+ kfree(nftl);
+}
+
+/* Search the MTD device for NFTL partitions */
+static void NFTL_notify_add(struct mtd_info *mtd)
+{
+ DEBUG(MTD_DEBUG_LEVEL1, "NFTL_notify_add for %s\n", mtd->name);
+
+ if (mtd) {
+ if (!mtd->read_oob) {
+ /* If this MTD doesn't have out-of-band data,
+ then there's no point continuing */
+ DEBUG(MTD_DEBUG_LEVEL1, "No OOB data, quitting\n");
+ return;
+ }
+ DEBUG(MTD_DEBUG_LEVEL3, "mtd->read = %p, size = %d, erasesize = %d\n",
+ mtd->read, mtd->size, mtd->erasesize);
+
+ NFTL_setup(mtd);
+ }
+}
+
+static void NFTL_notify_remove(struct mtd_info *mtd)
+{
+ int i;
+
+ for (i = 0; i < MAX_NFTLS; i++) {
+ if (NFTLs[i] && NFTLs[i]->mtd == mtd)
+ NFTL_unsetup(i);
+ }
+}
+
+#ifdef CONFIG_NFTL_RW
+
+/* Actual NFTL access routines */
+/* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used
+ * when the give Virtual Unit Chain
+ */
+static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate )
+{
+ /* For a given Virtual Unit Chain: find or create a free block and
+ add it to the chain */
+ /* We're passed the number of the last EUN in the chain, to save us from
+ having to look it up again */
+ u16 pot = nftl->LastFreeEUN;
+ int silly = -1;
+
+ /* Normally, we force a fold to happen before we run out of free blocks completely */
+ if (!desperate && nftl->numfreeEUNs < 2) {
+ DEBUG(MTD_DEBUG_LEVEL1, "NFTL_findfreeblock: there are too few free EUNs\n");
+ return 0xffff;
+ }
+
+ /* Scan for a free block */
+ do {
+ if (nftl->ReplUnitTable[pot] == BLOCK_FREE) {
+ nftl->LastFreeEUN = pot;
+ nftl->numfreeEUNs--;
+ return pot;
+ }
+
+ /* This will probably point to the MediaHdr unit itself,
+ right at the beginning of the partition. But that unit
+ (and the backup unit too) should have the UCI set
+ up so that it's not selected for overwriting */
+ if (++pot > nftl->lastEUN)
+ pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN);
+
+ if (!silly--) {
+ printk("Argh! No free blocks found! LastFreeEUN = %d, "
+ "FirstEUN = %d\n", nftl->LastFreeEUN,
+ le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN));
+ return 0xffff;
+ }
+ } while (pot != nftl->LastFreeEUN);
+
+ return 0xffff;
+}
+
+static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock )
+{
+ u16 BlockMap[MAX_SECTORS_PER_UNIT];
+ unsigned char BlockLastState[MAX_SECTORS_PER_UNIT];
+ unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT];
+ unsigned int thisEUN;
+ int block;
+ int silly;
+ unsigned int targetEUN;
+ struct nftl_oob oob;
+ int inplace = 1;
+ size_t retlen;
+
+ memset(BlockMap, 0xff, sizeof(BlockMap));
+ memset(BlockFreeFound, 0, sizeof(BlockFreeFound));
+
+ thisEUN = nftl->EUNtable[thisVUC];
+
+ if (thisEUN == BLOCK_NIL) {
+ printk(KERN_WARNING "Trying to fold non-existent "
+ "Virtual Unit Chain %d!\n", thisVUC);
+ return BLOCK_NIL;
+ }
+
+ /* Scan to find the Erase Unit which holds the actual data for each
+ 512-byte block within the Chain.
+ */
+ silly = MAX_LOOPS;
+ targetEUN = BLOCK_NIL;
+ while (thisEUN <= nftl->lastEUN ) {
+ unsigned int status, foldmark;
+
+ targetEUN = thisEUN;
+ for (block = 0; block < nftl->EraseSize / 512; block ++) {
+ MTD_READOOB(nftl->mtd,
+ (thisEUN * nftl->EraseSize) + (block * 512),
+ 16 , &retlen, (char *)&oob);
+ if (block == 2) {
+ foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1;
+ if (foldmark == FOLD_MARK_IN_PROGRESS) {
+ DEBUG(MTD_DEBUG_LEVEL1,
+ "Write Inhibited on EUN %d\n", thisEUN);
+ inplace = 0;
+ } else {
+ /* There's no other reason not to do inplace,
+ except ones that come later. So we don't need
+ to preserve inplace */
+ inplace = 1;
+ }
+ }
+ status = oob.b.Status | oob.b.Status1;
+ BlockLastState[block] = status;
+
+ switch(status) {
+ case SECTOR_FREE:
+ BlockFreeFound[block] = 1;
+ break;
+
+ case SECTOR_USED:
+ if (!BlockFreeFound[block])
+ BlockMap[block] = thisEUN;
+ else
+ printk(KERN_WARNING
+ "SECTOR_USED found after SECTOR_FREE "
+ "in Virtual Unit Chain %d for block %d\n",
+ thisVUC, block);
+ break;
+ case SECTOR_IGNORE:
+ case SECTOR_DELETED:
+ break;
+ default:
+ printk("Unknown status for block %d in EUN %d: %x\n",
+ block, thisEUN, status);
+ }
+ }
+
+ if (!silly--) {
+ printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n",
+ thisVUC);
+ return BLOCK_NIL;
+ }
+
+ thisEUN = nftl->ReplUnitTable[thisEUN];
+ }
+
+ if (inplace) {
+ /* We're being asked to be a fold-in-place. Check
+ that all blocks are either present or SECTOR_FREE
+ in the target block. If not, we're going to have
+ to fold out-of-place anyway.
+ */
+ for (block = 0; block < nftl->EraseSize / 512 ; block++) {
+ if (BlockLastState[block] != SECTOR_FREE &&
+ BlockMap[block] != targetEUN) {
+ DEBUG(MTD_DEBUG_LEVEL1, "Setting inplace to 0. VUC %d, "
+ "block %d was %x lastEUN, "
+ "and is in EUN %d (%s) %d\n",
+ thisVUC, block, BlockLastState[block],
+ BlockMap[block],
+ BlockMap[block]== targetEUN ? "==" : "!=",
+ targetEUN);
+ inplace = 0;
+ break;
+ }
+ }
+
+ if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) &&
+ pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) &&
+ BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] !=
+ SECTOR_FREE) {
+ DEBUG(MTD_DEBUG_LEVEL1, "Pending write not free in EUN %d. "
+ "Folding out of place.\n", targetEUN);
+ inplace = 0;
+ }
+ }
+
+ if (!inplace) {
+ DEBUG(MTD_DEBUG_LEVEL1, "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
+ fold-in-place of another chain to make room
+ for this one. We need a better way of selecting
+ which chain to fold, because makefreeblock will
+ only ask us to fold the same one again.
+ */
+ printk(KERN_WARNING
+ "NFTL_findfreeblock(desperate) returns 0xffff.\n");
+ return BLOCK_NIL;
+ }
+ } else {
+ /* We put a fold mark in the chain we are folding only if
+ we 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 longer one */
+ oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS);
+ oob.u.c.unused = 0xffffffff;
+ MTD_WRITEOOB(nftl->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,
+ and the Erase Unit into which we are supposed to be copying.
+ Go for it.
+ */
+ DEBUG(MTD_DEBUG_LEVEL1,"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_READECC(nftl->mtd, (nftl->EraseSize * BlockMap[block])
+ + (block * 512), 512, &retlen, movebuf, (char *)&oob);
+ if (ret < 0) {
+ ret = MTD_READECC(nftl->mtd, (nftl->EraseSize * BlockMap[block])
+ + (block * 512), 512, &retlen,
+ movebuf, (char *)&oob);
+ if (ret != -EIO)
+ printk("Error went away on retry.\n");
+ }
+ MTD_WRITEECC(nftl->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 = 0xffff;
+
+ MTD_WRITEOOB(nftl->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];
+ DEBUG(MTD_DEBUG_LEVEL1,"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
+ * FixMe: Update Bad Unit Table on disk
+ */
+ 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;
+}
+
+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 < 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 0xffff;
+ }
+
+ 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);
+ 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;
+
+ MTD_READOOB(nftl->mtd, (writeEUN * nftl->EraseSize) + blockofs,
+ 8, &retlen, (char *)&bci);
+
+ DEBUG(MTD_DEBUG_LEVEL2, "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 0xffff;
+ }
+
+ /* 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, 0xffff);
+
+ 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.
+ */
+ DEBUG(MTD_DEBUG_LEVEL1, "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");
+ lastEUN = BLOCK_NIL;
+ 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 */
+ MTD_READOOB(nftl->mtd, writeEUN * nftl->EraseSize + 8, 8,
+ &retlen, (char *)&oob.u);
+
+ oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC);
+
+ MTD_WRITEOOB(nftl->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 */
+ MTD_READOOB(nftl->mtd, (lastEUN * nftl->EraseSize) + 8,
+ 8, &retlen, (char *)&oob.u);
+
+ oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum
+ = cpu_to_le16(writeEUN);
+
+ MTD_WRITEOOB(nftl->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 0xffff;
+}
+
+static int NFTL_writeblock(struct NFTLrecord *nftl, unsigned block, char *buffer)
+{
+ u16 writeEUN;
+ unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1);
+ size_t retlen;
+ u8 eccbuf[6];
+
+ 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;
+ }
+
+ MTD_WRITEECC(nftl->mtd, (writeEUN * nftl->EraseSize) + blockofs,
+ 512, &retlen, (char *)buffer, (char *)eccbuf);
+ /* no need to write SECTOR_USED flags since they are written in mtd_writeecc */
+
+ return 0;
+}
+#endif /* CONFIG_NFTL_RW */
+
+static int NFTL_readblock(struct NFTLrecord *nftl, unsigned block, char *buffer)
+{
+ 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 (MTD_READOOB(nftl->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 %d in EUN %d: %x\n",
+ block, thisEUN, status);
+ break;
+ }
+
+ if (!silly--) {
+ printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\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;
+ u_char eccbuf[6];
+ if (MTD_READECC(nftl->mtd, ptr, 512, &retlen, buffer, eccbuf))
+ return -EIO;
+ }
+ return 0;
+}
+
+static int nftl_ioctl(struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg)
+{
+ struct NFTLrecord *nftl;
+ int p;
+
+ nftl = NFTLs[MINOR(inode->i_rdev) >> NFTL_PARTN_BITS];
+
+ if (!nftl) return -EINVAL;
+
+ switch (cmd) {
+ case HDIO_GETGEO: {
+ struct hd_geometry g;
+
+ g.heads = nftl->heads;
+ g.sectors = nftl->sectors;
+ g.cylinders = nftl->cylinders;
+ g.start = part_table[MINOR(inode->i_rdev)].start_sect;
+ return copy_to_user((void *)arg, &g, sizeof g) ? -EFAULT : 0;
+ }
+ case BLKGETSIZE: /* Return device size */
+ if (!arg) return -EINVAL;
+ return put_user(part_table[MINOR(inode->i_rdev)].nr_sects,
+ (long *) arg);
+
+ case BLKFLSBUF:
+ if (!capable(CAP_SYS_ADMIN)) return -EACCES;
+ fsync_dev(inode->i_rdev);
+ invalidate_buffers(inode->i_rdev);
+ if (nftl->mtd->sync)
+ nftl->mtd->sync(nftl->mtd);
+ return 0;
+
+ case BLKRRPART:
+ if (!capable(CAP_SYS_ADMIN)) return -EACCES;
+ if (nftl->usecount > 1) return -EBUSY;
+ /*
+ * We have to flush all buffers and invalidate caches,
+ * or we won't be able to re-use the partitions,
+ * if there was a change and we don't want to reboot
+ */
+ p = (1<<NFTL_PARTN_BITS) - 1;
+ while (p-- > 0) {
+ kdev_t devp = MKDEV(MAJOR(inode->i_dev), MINOR(inode->i_dev)+p);
+ if (part_table[p].nr_sects > 0)
+ invalidate_device (devp, 1);
+
+ part_table[MINOR(inode->i_dev)+p].start_sect = 0;
+ part_table[MINOR(inode->i_dev)+p].nr_sects = 0;
+ }
+
+#if LINUX_VERSION_CODE < 0x20328
+ resetup_one_dev(&nftl_gendisk, MINOR(inode->i_rdev) >> NFTL_PARTN_BITS);
+#else
+ grok_partitions(&nftl_gendisk, MINOR(inode->i_rdev) >> NFTL_PARTN_BITS,
+ 1<<NFTL_PARTN_BITS, nftl->nr_sects);
+#endif
+ return 0;
+
+#if (LINUX_VERSION_CODE < 0x20303)
+ RO_IOCTLS(inode->i_rdev, arg); /* ref. linux/blk.h */
+#else
+ case BLKROSET:
+ case BLKROGET:
+ case BLKSSZGET:
+ return blk_ioctl(inode->i_rdev, cmd, arg);
+#endif
+
+ default:
+ return -EINVAL;
+ }
+}
+
+void nftl_request(RQFUNC_ARG)
+{
+ unsigned int dev, block, nsect;
+ struct NFTLrecord *nftl;
+ char *buffer;
+ struct request *req;
+ int res;
+
+ while (1) {
+ INIT_REQUEST; /* blk.h */
+ req = CURRENT;
+
+ /* We can do this because the generic code knows not to
+ touch the request at the head of the queue */
+ spin_unlock_irq(&io_request_lock);
+
+ DEBUG(MTD_DEBUG_LEVEL2, "NFTL_request\n");
+ DEBUG(MTD_DEBUG_LEVEL3, "NFTL %s request, from sector 0x%04lx for 0x%04lx sectors\n",
+ (req->cmd == READ) ? "Read " : "Write",
+ req->sector, req->current_nr_sectors);
+
+ dev = MINOR(req->rq_dev);
+ block = req->sector;
+ nsect = req->current_nr_sectors;
+ buffer = req->buffer;
+ res = 1; /* succeed */
+
+ if (dev >= MAX_NFTLS * (1<<NFTL_PARTN_BITS)) {
+ /* there is no such partition */
+ printk("nftl: bad minor number: device = %s\n",
+ kdevname(req->rq_dev));
+ res = 0; /* fail */
+ goto repeat;
+ }
+
+ nftl = NFTLs[dev / (1<<NFTL_PARTN_BITS)];
+ DEBUG(MTD_DEBUG_LEVEL3, "Waiting for mutex\n");
+ down(&nftl->mutex);
+ DEBUG(MTD_DEBUG_LEVEL3, "Got mutex\n");
+
+ if (block + nsect > part_table[dev].nr_sects) {
+ /* access past the end of device */
+ printk("nftl%c%d: bad access: block = %d, count = %d\n",
+ (MINOR(req->rq_dev)>>6)+'a', dev & 0xf, block, nsect);
+ up(&nftl->mutex);
+ res = 0; /* fail */
+ goto repeat;
+ }
+
+ block += part_table[dev].start_sect;
+
+ if (req->cmd == READ) {
+ DEBUG(MTD_DEBUG_LEVEL2, "NFTL read request of 0x%x sectors @ %x "
+ "(req->nr_sectors == %lx)\n", nsect, block, req->nr_sectors);
+
+ for ( ; nsect > 0; nsect-- , block++, buffer += 512) {
+ /* Read a single sector to req->buffer + (512 * i) */
+ if (NFTL_readblock(nftl, block, buffer)) {
+ DEBUG(MTD_DEBUG_LEVEL2, "NFTL read request failed\n");
+ up(&nftl->mutex);
+ res = 0;
+ goto repeat;
+ }
+ }
+
+ DEBUG(MTD_DEBUG_LEVEL2,"NFTL read request completed OK\n");
+ up(&nftl->mutex);
+ goto repeat;
+ } else if (req->cmd == WRITE) {
+ DEBUG(MTD_DEBUG_LEVEL2, "NFTL write request of 0x%x sectors @ %x "
+ "(req->nr_sectors == %lx)\n", nsect, block,
+ req->nr_sectors);
+#ifdef CONFIG_NFTL_RW
+ for ( ; nsect > 0; nsect-- , block++, buffer += 512) {
+ /* Read a single sector to req->buffer + (512 * i) */
+ if (NFTL_writeblock(nftl, block, buffer)) {
+ DEBUG(MTD_DEBUG_LEVEL1,"NFTL write request failed\n");
+ up(&nftl->mutex);
+ res = 0;
+ goto repeat;
+ }
+ }
+ DEBUG(MTD_DEBUG_LEVEL2,"NFTL write request completed OK\n");
+#else
+ res = 0; /* Writes always fail */
+#endif /* CONFIG_NFTL_RW */
+ up(&nftl->mutex);
+ goto repeat;
+ } else {
+ DEBUG(MTD_DEBUG_LEVEL0, "NFTL unknown request\n");
+ up(&nftl->mutex);
+ res = 0;
+ goto repeat;
+ }
+ repeat:
+ DEBUG(MTD_DEBUG_LEVEL3, "end_request(%d)\n", res);
+ spin_lock_irq(&io_request_lock);
+ end_request(res);
+ }
+}
+
+static int nftl_open(struct inode *ip, struct file *fp)
+{
+ int nftlnum = MINOR(ip->i_rdev) >> NFTL_PARTN_BITS;
+ struct NFTLrecord *thisNFTL;
+ thisNFTL = NFTLs[nftlnum];
+
+ DEBUG(MTD_DEBUG_LEVEL2,"NFTL_open\n");
+
+#ifdef CONFIG_KMOD
+ if (!thisNFTL && nftlnum == 0) {
+ request_module("docprobe");
+ thisNFTL = NFTLs[nftlnum];
+ }
+#endif
+ if (!thisNFTL) {
+ DEBUG(MTD_DEBUG_LEVEL2,"ENODEV: thisNFTL = %d, minor = %d, ip = %p, fp = %p\n",
+ nftlnum, ip->i_rdev, ip, fp);
+ return -ENODEV;
+ }
+
+#ifndef CONFIG_NFTL_RW
+ if (fp->f_mode & FMODE_WRITE)
+ return -EROFS;
+#endif /* !CONFIG_NFTL_RW */
+
+ thisNFTL->usecount++;
+ MOD_INC_USE_COUNT;
+ if (!get_mtd_device(thisNFTL->mtd, -1)) {
+ MOD_DEC_USE_COUNT;
+ return /* -E'SBUGGEREDOFF */ -ENXIO;
+ }
+
+ return 0;
+}
+
+static int nftl_release(struct inode *inode, struct file *fp)
+{
+ struct NFTLrecord *thisNFTL;
+
+ thisNFTL = NFTLs[MINOR(inode->i_rdev) / 16];
+
+ DEBUG(MTD_DEBUG_LEVEL2, "NFTL_release\n");
+
+ invalidate_device(inode->i_rdev, 1);
+
+ if (thisNFTL->mtd->sync)
+ thisNFTL->mtd->sync(thisNFTL->mtd);
+ thisNFTL->usecount--;
+ MOD_DEC_USE_COUNT;
+
+ put_mtd_device(thisNFTL->mtd);
+
+ return 0;
+}
+#if LINUX_VERSION_CODE < 0x20326
+static struct file_operations nftl_fops = {
+ read: block_read,
+ write: block_write,
+ ioctl: nftl_ioctl,
+ open: nftl_open,
+ release: nftl_release,
+ fsync: block_fsync,
+};
+#else
+static struct block_device_operations nftl_fops =
+{
+ open: nftl_open,
+ release: nftl_release,
+ ioctl: nftl_ioctl
+};
+#endif
+
+
+
+/****************************************************************************
+ *
+ * Module stuff
+ *
+ ****************************************************************************/
+
+#if LINUX_VERSION_CODE < 0x20212 && defined(MODULE)
+#define init_nftl init_module
+#define cleanup_nftl cleanup_module
+#endif
+
+static struct mtd_notifier nftl_notifier = {
+ add: NFTL_notify_add,
+ remove: NFTL_notify_remove
+};
+
+static int __init init_nftl(void)
+{
+ int i;
+
+ printk(KERN_NOTICE
+ "M-Systems NAND Flash Translation Layer driver. (C) 1999 MVHI\n");
+#ifdef PRERELEASE
+ printk(KERN_INFO"$Id: nftlcore.c,v 1.73 2001/06/09 01:09:43 dwmw2 Exp $\n");
+#endif
+
+ if (register_blkdev(MAJOR_NR, "nftl", &nftl_fops)){
+ printk("unable to register NFTL block device on major %d\n", MAJOR_NR);
+ return -EBUSY;
+ } else {
+#if LINUX_VERSION_CODE < 0x20320
+ blk_dev[MAJOR_NR].request_fn = nftl_request;
+#else
+ blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), &nftl_request);
+#endif
+ /* set block size to 1kB each */
+ for (i = 0; i < 256; i++) {
+ nftl_blocksizes[i] = 1024;
+ }
+ blksize_size[MAJOR_NR] = nftl_blocksizes;
+
+ nftl_gendisk.next = gendisk_head;
+ gendisk_head = &nftl_gendisk;
+ }
+
+ register_mtd_user(&nftl_notifier);
+
+ return 0;
+}
+
+static void __exit cleanup_nftl(void)
+{
+ struct gendisk *gd, **gdp;
+
+ unregister_mtd_user(&nftl_notifier);
+ unregister_blkdev(MAJOR_NR, "nftl");
+
+#if LINUX_VERSION_CODE < 0x20320
+ blk_dev[MAJOR_NR].request_fn = 0;
+#else
+ blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
+#endif
+
+ /* remove ourself from generic harddisk list
+ FIXME: why can't I found this partition on /proc/partition */
+ for (gdp = &gendisk_head; *gdp; gdp = &((*gdp)->next))
+ if (*gdp == &nftl_gendisk) {
+ gd = *gdp; *gdp = gd->next;
+ break;
+ }
+}
+
+module_init(init_nftl);
+module_exit(cleanup_nftl);
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)