--- /dev/null
+/*
+ * Linux driver for NAND Flash Translation Layer
+ *
+ * Copyright © 1999 Machine Vision Holdings, Inc.
+ * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#define PRERELEASE
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/hdreg.h>
+#include <linux/blkdev.h>
+
+#include <linux/kmod.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nftl.h>
+#include <linux/mtd/blktrans.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
+
+
+static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
+{
+ struct NFTLrecord *nftl;
+ unsigned long temp;
+
+ if (!mtd_type_is_nand(mtd) || mtd->size > UINT_MAX)
+ return;
+ /* OK, this is moderately ugly. But probably safe. Alternatives? */
+ if (memcmp(mtd->name, "DiskOnChip", 10))
+ return;
+
+ pr_debug("NFTL: add_mtd for %s\n", mtd->name);
+
+ nftl = kzalloc(sizeof(struct NFTLrecord), GFP_KERNEL);
+
+ if (!nftl)
+ return;
+
+ nftl->mbd.mtd = mtd;
+ nftl->mbd.devnum = -1;
+
+ nftl->mbd.tr = tr;
+
+ if (NFTL_mount(nftl) < 0) {
+ printk(KERN_WARNING "NFTL: could not mount device\n");
+ kfree(nftl);
+ return;
+ }
+
+ /* OK, it's a new one. Set up all the data structures. */
+
+ /* Calculate geometry */
+ nftl->cylinders = 1024;
+ nftl->heads = 16;
+
+ temp = nftl->cylinders * nftl->heads;
+ nftl->sectors = nftl->mbd.size / temp;
+ if (nftl->mbd.size % temp) {
+ nftl->sectors++;
+ temp = nftl->cylinders * nftl->sectors;
+ nftl->heads = nftl->mbd.size / temp;
+
+ if (nftl->mbd.size % temp) {
+ nftl->heads++;
+ temp = nftl->heads * nftl->sectors;
+ nftl->cylinders = nftl->mbd.size / temp;
+ }
+ }
+
+ if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) {
+ /*
+ Oh no we don't have
+ mbd.size == heads * cylinders * sectors
+ */
+ printk(KERN_WARNING "NFTL: cannot calculate a geometry to "
+ "match size of 0x%lx.\n", nftl->mbd.size);
+ printk(KERN_WARNING "NFTL: 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 );
+ }
+
+ if (add_mtd_blktrans_dev(&nftl->mbd)) {
+ kfree(nftl->ReplUnitTable);
+ kfree(nftl->EUNtable);
+ kfree(nftl);
+ return;
+ }
+#ifdef PSYCHO_DEBUG
+ printk(KERN_INFO "NFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a');
+#endif
+}
+
+static void nftl_remove_dev(struct mtd_blktrans_dev *dev)
+{
+ struct NFTLrecord *nftl = (void *)dev;
+
+ pr_debug("NFTL: remove_dev (i=%d)\n", dev->devnum);
+
+ del_mtd_blktrans_dev(dev);
+ kfree(nftl->ReplUnitTable);
+ kfree(nftl->EUNtable);
+}
+
+/*
+ * Read oob data from flash
+ */
+int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
+ size_t *retlen, uint8_t *buf)
+{
+ loff_t mask = mtd->writesize - 1;
+ struct mtd_oob_ops ops;
+ int res;
+
+ ops.mode = MTD_OPS_PLACE_OOB;
+ ops.ooboffs = offs & mask;
+ ops.ooblen = len;
+ ops.oobbuf = buf;
+ ops.datbuf = NULL;
+
+ res = mtd_read_oob(mtd, offs & ~mask, &ops);
+ *retlen = ops.oobretlen;
+ return res;
+}
+
+/*
+ * Write oob data to flash
+ */
+int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
+ size_t *retlen, uint8_t *buf)
+{
+ loff_t mask = mtd->writesize - 1;
+ struct mtd_oob_ops ops;
+ int res;
+
+ ops.mode = MTD_OPS_PLACE_OOB;
+ ops.ooboffs = offs & mask;
+ ops.ooblen = len;
+ ops.oobbuf = buf;
+ ops.datbuf = NULL;
+
+ res = mtd_write_oob(mtd, offs & ~mask, &ops);
+ *retlen = ops.oobretlen;
+ return res;
+}
+
+#ifdef CONFIG_NFTL_RW
+
+/*
+ * Write data and oob to flash
+ */
+static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
+ size_t *retlen, uint8_t *buf, uint8_t *oob)
+{
+ loff_t mask = mtd->writesize - 1;
+ struct mtd_oob_ops ops;
+ int res;
+
+ ops.mode = MTD_OPS_PLACE_OOB;
+ ops.ooboffs = offs & mask;
+ ops.ooblen = mtd->oobsize;
+ ops.oobbuf = oob;
+ ops.datbuf = buf;
+ ops.len = len;
+
+ res = mtd_write_oob(mtd, offs & ~mask, &ops);
+ *retlen = ops.retlen;
+ return res;
+}
+
+/* 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 = nftl->nb_blocks;
+
+ /* Normally, we force a fold to happen before we run out of free blocks completely */
+ if (!desperate && nftl->numfreeEUNs < 2) {
+ pr_debug("NFTL_findfreeblock: there are too few free EUNs\n");
+ return BLOCK_NIL;
+ }
+
+ /* 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 BLOCK_NIL;
+ }
+ } while (pot != nftl->LastFreeEUN);
+
+ return BLOCK_NIL;
+}
+
+static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock )
+{
+ struct mtd_info *mtd = nftl->mbd.mtd;
+ 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 ++) {
+ nftl_read_oob(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) {
+ pr_debug("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_DELETED:
+ if (!BlockFreeFound[block])
+ BlockMap[block] = BLOCK_NIL;
+ else
+ printk(KERN_WARNING
+ "SECTOR_DELETED found after SECTOR_FREE "
+ "in Virtual Unit Chain %d for block %d\n",
+ thisVUC, block);
+ break;
+
+ case SECTOR_IGNORE:
+ 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 which actually have data associated
+ with them (i.e. BlockMap[block] != BLOCK_NIL) are
+ either already 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] != BLOCK_NIL &&
+ BlockMap[block] != targetEUN) {
+ pr_debug("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) {
+ pr_debug("Pending write not free in EUN %d. "
+ "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
+ 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;
+ 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,
+ and the Erase Unit into which we are supposed to be copying.
+ 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,
+ (nftl->EraseSize * BlockMap[block]) + (block * 512),
+ 512,
+ &retlen,
+ movebuf);
+ if (ret < 0 && !mtd_is_bitflip(ret)) {
+ ret = mtd_read(mtd,
+ (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");
+ 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 */
+ 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,
+};
+
+static int __init init_nftl(void)
+{
+ return register_mtd_blktrans(&nftl_tr);
+}
+
+static void __exit cleanup_nftl(void)
+{
+ deregister_mtd_blktrans(&nftl_tr);
+}
+
+module_init(init_nftl);
+module_exit(cleanup_nftl);
+
+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);
Code Review / kvmfornfv.git / blobdiff