--- /dev/null
+/*
+ * inftlcore.c -- Linux driver for Inverse Flash Translation Layer (INFTL)
+ *
+ * Copyright © 2002, Greg Ungerer (gerg@snapgear.com)
+ *
+ * Based heavily on the nftlcore.c code which is:
+ * Copyright © 1999 Machine Vision Holdings, Inc.
+ * Copyright © 1999 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
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/kmod.h>
+#include <linux/hdreg.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nftl.h>
+#include <linux/mtd/inftl.h>
+#include <linux/mtd/nand.h>
+#include <asm/uaccess.h>
+#include <asm/errno.h>
+#include <asm/io.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 inftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
+{
+ struct INFTLrecord *inftl;
+ 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;
+
+ if (!mtd->_block_isbad) {
+ printk(KERN_ERR
+"INFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n"
+"Please use the new diskonchip driver under the NAND subsystem.\n");
+ return;
+ }
+
+ pr_debug("INFTL: add_mtd for %s\n", mtd->name);
+
+ inftl = kzalloc(sizeof(*inftl), GFP_KERNEL);
+
+ if (!inftl)
+ return;
+
+ inftl->mbd.mtd = mtd;
+ inftl->mbd.devnum = -1;
+
+ inftl->mbd.tr = tr;
+
+ if (INFTL_mount(inftl) < 0) {
+ printk(KERN_WARNING "INFTL: could not mount device\n");
+ kfree(inftl);
+ return;
+ }
+
+ /* OK, it's a new one. Set up all the data structures. */
+
+ /* Calculate geometry */
+ inftl->cylinders = 1024;
+ inftl->heads = 16;
+
+ temp = inftl->cylinders * inftl->heads;
+ inftl->sectors = inftl->mbd.size / temp;
+ if (inftl->mbd.size % temp) {
+ inftl->sectors++;
+ temp = inftl->cylinders * inftl->sectors;
+ inftl->heads = inftl->mbd.size / temp;
+
+ if (inftl->mbd.size % temp) {
+ inftl->heads++;
+ temp = inftl->heads * inftl->sectors;
+ inftl->cylinders = inftl->mbd.size / temp;
+ }
+ }
+
+ if (inftl->mbd.size != inftl->heads * inftl->cylinders * inftl->sectors) {
+ /*
+ Oh no we don't have
+ mbd.size == heads * cylinders * sectors
+ */
+ printk(KERN_WARNING "INFTL: cannot calculate a geometry to "
+ "match size of 0x%lx.\n", inftl->mbd.size);
+ printk(KERN_WARNING "INFTL: using C:%d H:%d S:%d "
+ "(== 0x%lx sects)\n",
+ inftl->cylinders, inftl->heads , inftl->sectors,
+ (long)inftl->cylinders * (long)inftl->heads *
+ (long)inftl->sectors );
+ }
+
+ if (add_mtd_blktrans_dev(&inftl->mbd)) {
+ kfree(inftl->PUtable);
+ kfree(inftl->VUtable);
+ kfree(inftl);
+ return;
+ }
+#ifdef PSYCHO_DEBUG
+ printk(KERN_INFO "INFTL: Found new inftl%c\n", inftl->mbd.devnum + 'a');
+#endif
+ return;
+}
+
+static void inftl_remove_dev(struct mtd_blktrans_dev *dev)
+{
+ struct INFTLrecord *inftl = (void *)dev;
+
+ pr_debug("INFTL: remove_dev (i=%d)\n", dev->devnum);
+
+ del_mtd_blktrans_dev(dev);
+
+ kfree(inftl->PUtable);
+ kfree(inftl->VUtable);
+}
+
+/*
+ * Actual INFTL access routines.
+ */
+
+/*
+ * Read oob data from flash
+ */
+int inftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
+ size_t *retlen, uint8_t *buf)
+{
+ struct mtd_oob_ops ops;
+ int res;
+
+ ops.mode = MTD_OPS_PLACE_OOB;
+ ops.ooboffs = offs & (mtd->writesize - 1);
+ ops.ooblen = len;
+ ops.oobbuf = buf;
+ ops.datbuf = NULL;
+
+ res = mtd_read_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+ *retlen = ops.oobretlen;
+ return res;
+}
+
+/*
+ * Write oob data to flash
+ */
+int inftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
+ size_t *retlen, uint8_t *buf)
+{
+ struct mtd_oob_ops ops;
+ int res;
+
+ ops.mode = MTD_OPS_PLACE_OOB;
+ ops.ooboffs = offs & (mtd->writesize - 1);
+ ops.ooblen = len;
+ ops.oobbuf = buf;
+ ops.datbuf = NULL;
+
+ res = mtd_write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+ *retlen = ops.oobretlen;
+ return res;
+}
+
+/*
+ * Write data and oob to flash
+ */
+static int inftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
+ size_t *retlen, uint8_t *buf, uint8_t *oob)
+{
+ struct mtd_oob_ops ops;
+ int res;
+
+ ops.mode = MTD_OPS_PLACE_OOB;
+ ops.ooboffs = offs;
+ ops.ooblen = mtd->oobsize;
+ ops.oobbuf = oob;
+ ops.datbuf = buf;
+ ops.len = len;
+
+ res = mtd_write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
+ *retlen = ops.retlen;
+ return res;
+}
+
+/*
+ * INFTL_findfreeblock: Find a free Erase Unit on the INFTL partition.
+ * This function is used when the give Virtual Unit Chain.
+ */
+static u16 INFTL_findfreeblock(struct INFTLrecord *inftl, int desperate)
+{
+ u16 pot = inftl->LastFreeEUN;
+ int silly = inftl->nb_blocks;
+
+ pr_debug("INFTL: INFTL_findfreeblock(inftl=%p,desperate=%d)\n",
+ inftl, desperate);
+
+ /*
+ * Normally, we force a fold to happen before we run out of free
+ * blocks completely.
+ */
+ if (!desperate && inftl->numfreeEUNs < 2) {
+ pr_debug("INFTL: there are too few free EUNs (%d)\n",
+ inftl->numfreeEUNs);
+ return BLOCK_NIL;
+ }
+
+ /* Scan for a free block */
+ do {
+ if (inftl->PUtable[pot] == BLOCK_FREE) {
+ inftl->LastFreeEUN = pot;
+ return pot;
+ }
+
+ if (++pot > inftl->lastEUN)
+ pot = 0;
+
+ if (!silly--) {
+ printk(KERN_WARNING "INFTL: no free blocks found! "
+ "EUN range = %d - %d\n", 0, inftl->LastFreeEUN);
+ return BLOCK_NIL;
+ }
+ } while (pot != inftl->LastFreeEUN);
+
+ return BLOCK_NIL;
+}
+
+static u16 INFTL_foldchain(struct INFTLrecord *inftl, unsigned thisVUC, unsigned pendingblock)
+{
+ u16 BlockMap[MAX_SECTORS_PER_UNIT];
+ unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
+ unsigned int thisEUN, prevEUN, status;
+ struct mtd_info *mtd = inftl->mbd.mtd;
+ int block, silly;
+ unsigned int targetEUN;
+ struct inftl_oob oob;
+ size_t retlen;
+
+ pr_debug("INFTL: INFTL_foldchain(inftl=%p,thisVUC=%d,pending=%d)\n",
+ inftl, thisVUC, pendingblock);
+
+ memset(BlockMap, 0xff, sizeof(BlockMap));
+ memset(BlockDeleted, 0, sizeof(BlockDeleted));
+
+ thisEUN = targetEUN = inftl->VUtable[thisVUC];
+
+ if (thisEUN == BLOCK_NIL) {
+ printk(KERN_WARNING "INFTL: 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;
+ while (thisEUN < inftl->nb_blocks) {
+ for (block = 0; block < inftl->EraseSize/SECTORSIZE; block ++) {
+ if ((BlockMap[block] != BLOCK_NIL) ||
+ BlockDeleted[block])
+ continue;
+
+ if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize)
+ + (block * SECTORSIZE), 16, &retlen,
+ (char *)&oob) < 0)
+ status = SECTOR_IGNORE;
+ else
+ status = oob.b.Status | oob.b.Status1;
+
+ switch(status) {
+ case SECTOR_FREE:
+ case SECTOR_IGNORE:
+ break;
+ case SECTOR_USED:
+ BlockMap[block] = thisEUN;
+ continue;
+ case SECTOR_DELETED:
+ BlockDeleted[block] = 1;
+ continue;
+ default:
+ printk(KERN_WARNING "INFTL: unknown status "
+ "for block %d in EUN %d: %x\n",
+ block, thisEUN, status);
+ break;
+ }
+ }
+
+ if (!silly--) {
+ printk(KERN_WARNING "INFTL: infinite loop in Virtual "
+ "Unit Chain 0x%x\n", thisVUC);
+ return BLOCK_NIL;
+ }
+
+ thisEUN = inftl->PUtable[thisEUN];
+ }
+
+ /*
+ * 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("INFTL: folding chain %d into unit %d\n", thisVUC, targetEUN);
+
+ for (block = 0; block < inftl->EraseSize/SECTORSIZE ; block++) {
+ unsigned char movebuf[SECTORSIZE];
+ int ret;
+
+ /*
+ * If it's in the target EUN already, or if it's pending write,
+ * do nothing.
+ */
+ if (BlockMap[block] == targetEUN || (pendingblock ==
+ (thisVUC * (inftl->EraseSize / SECTORSIZE) + 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,
+ (inftl->EraseSize * BlockMap[block]) + (block * SECTORSIZE),
+ SECTORSIZE,
+ &retlen,
+ movebuf);
+ if (ret < 0 && !mtd_is_bitflip(ret)) {
+ ret = mtd_read(mtd,
+ (inftl->EraseSize * BlockMap[block]) + (block * SECTORSIZE),
+ SECTORSIZE,
+ &retlen,
+ movebuf);
+ if (ret != -EIO)
+ pr_debug("INFTL: error went away on retry?\n");
+ }
+ memset(&oob, 0xff, sizeof(struct inftl_oob));
+ oob.b.Status = oob.b.Status1 = SECTOR_USED;
+
+ inftl_write(inftl->mbd.mtd, (inftl->EraseSize * targetEUN) +
+ (block * SECTORSIZE), SECTORSIZE, &retlen,
+ movebuf, (char *)&oob);
+ }
+
+ /*
+ * Newest unit in chain now contains data from _all_ older units.
+ * So go through and erase each unit in chain, oldest first. (This
+ * is important, by doing oldest first if we crash/reboot then it
+ * it is relatively simple to clean up the mess).
+ */
+ pr_debug("INFTL: want to erase virtual chain %d\n", thisVUC);
+
+ for (;;) {
+ /* Find oldest unit in chain. */
+ thisEUN = inftl->VUtable[thisVUC];
+ prevEUN = BLOCK_NIL;
+ while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
+ prevEUN = thisEUN;
+ thisEUN = inftl->PUtable[thisEUN];
+ }
+
+ /* Check if we are all done */
+ if (thisEUN == targetEUN)
+ break;
+
+ /* Unlink the last block from the chain. */
+ inftl->PUtable[prevEUN] = BLOCK_NIL;
+
+ /* Now try to erase it. */
+ if (INFTL_formatblock(inftl, thisEUN) < 0) {
+ /*
+ * Could not erase : mark block as reserved.
+ */
+ inftl->PUtable[thisEUN] = BLOCK_RESERVED;
+ } else {
+ /* Correctly erased : mark it as free */
+ inftl->PUtable[thisEUN] = BLOCK_FREE;
+ inftl->numfreeEUNs++;
+ }
+ }
+
+ return targetEUN;
+}
+
+static u16 INFTL_makefreeblock(struct INFTLrecord *inftl, 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;
+
+ pr_debug("INFTL: INFTL_makefreeblock(inftl=%p,"
+ "pending=%d)\n", inftl, pendingblock);
+
+ for (chain = 0; chain < inftl->nb_blocks; chain++) {
+ EUN = inftl->VUtable[chain];
+ thislen = 0;
+
+ while (EUN <= inftl->lastEUN) {
+ thislen++;
+ EUN = inftl->PUtable[EUN];
+ if (thislen > 0xff00) {
+ printk(KERN_WARNING "INFTL: endless loop in "
+ "Virtual Chain %d: Unit %x\n",
+ chain, EUN);
+ /*
+ * Actually, don't return failure.
+ * Just ignore this chain and get on with it.
+ */
+ thislen = 0;
+ break;
+ }
+ }
+
+ if (thislen > ChainLength) {
+ ChainLength = thislen;
+ LongestChain = chain;
+ }
+ }
+
+ if (ChainLength < 2) {
+ printk(KERN_WARNING "INFTL: no Virtual Unit Chains available "
+ "for folding. Failing request\n");
+ return BLOCK_NIL;
+ }
+
+ return INFTL_foldchain(inftl, LongestChain, pendingblock);
+}
+
+static int nrbits(unsigned int val, int bitcount)
+{
+ int i, total = 0;
+
+ for (i = 0; (i < bitcount); i++)
+ total += (((0x1 << i) & val) ? 1 : 0);
+ return total;
+}
+
+/*
+ * INFTL_findwriteunit: Return the unit number into which we can write
+ * for this block. Make it available if it isn't already.
+ */
+static inline u16 INFTL_findwriteunit(struct INFTLrecord *inftl, unsigned block)
+{
+ unsigned int thisVUC = block / (inftl->EraseSize / SECTORSIZE);
+ unsigned int thisEUN, writeEUN, prev_block, status;
+ unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize -1);
+ struct mtd_info *mtd = inftl->mbd.mtd;
+ struct inftl_oob oob;
+ struct inftl_bci bci;
+ unsigned char anac, nacs, parity;
+ size_t retlen;
+ int silly, silly2 = 3;
+
+ pr_debug("INFTL: INFTL_findwriteunit(inftl=%p,block=%d)\n",
+ inftl, block);
+
+ do {
+ /*
+ * Scan the media to find a unit in the VUC which has
+ * a free space for the block in question.
+ */
+ writeEUN = BLOCK_NIL;
+ thisEUN = inftl->VUtable[thisVUC];
+ silly = MAX_LOOPS;
+
+ while (thisEUN <= inftl->lastEUN) {
+ inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
+ blockofs, 8, &retlen, (char *)&bci);
+
+ status = bci.Status | bci.Status1;
+ pr_debug("INFTL: status of block %d in EUN %d is %x\n",
+ block , writeEUN, status);
+
+ switch(status) {
+ case SECTOR_FREE:
+ writeEUN = thisEUN;
+ break;
+ case SECTOR_DELETED:
+ case SECTOR_USED:
+ /* Can't go any further */
+ goto hitused;
+ case SECTOR_IGNORE:
+ break;
+ default:
+ /*
+ * Invalid block. Don't use it any more.
+ * Must implement.
+ */
+ break;
+ }
+
+ if (!silly--) {
+ printk(KERN_WARNING "INFTL: infinite loop in "
+ "Virtual Unit Chain 0x%x\n", thisVUC);
+ return BLOCK_NIL;
+ }
+
+ /* Skip to next block in chain */
+ thisEUN = inftl->PUtable[thisEUN];
+ }
+
+hitused:
+ if (writeEUN != BLOCK_NIL)
+ return writeEUN;
+
+
+ /*
+ * OK. We didn't find one in the existing chain, or there
+ * is no existing chain. Allocate a new one.
+ */
+ writeEUN = INFTL_findfreeblock(inftl, 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.
+ */
+ thisEUN = INFTL_makefreeblock(inftl, block);
+
+ /*
+ * Hopefully we free something, lets try again.
+ * This time we are desperate...
+ */
+ pr_debug("INFTL: using desperate==1 to find free EUN "
+ "to accommodate write to VUC %d\n",
+ thisVUC);
+ writeEUN = INFTL_findfreeblock(inftl, 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 "INFTL: cannot make free "
+ "space.\n");
+#ifdef DEBUG
+ INFTL_dumptables(inftl);
+ INFTL_dumpVUchains(inftl);
+#endif
+ return BLOCK_NIL;
+ }
+ }
+
+ /*
+ * Insert new block into virtual chain. Firstly update the
+ * block headers in flash...
+ */
+ anac = 0;
+ nacs = 0;
+ thisEUN = inftl->VUtable[thisVUC];
+ if (thisEUN != BLOCK_NIL) {
+ inftl_read_oob(mtd, thisEUN * inftl->EraseSize
+ + 8, 8, &retlen, (char *)&oob.u);
+ anac = oob.u.a.ANAC + 1;
+ nacs = oob.u.a.NACs + 1;
+ }
+
+ prev_block = inftl->VUtable[thisVUC];
+ if (prev_block < inftl->nb_blocks)
+ prev_block -= inftl->firstEUN;
+
+ parity = (nrbits(thisVUC, 16) & 0x1) ? 0x1 : 0;
+ parity |= (nrbits(prev_block, 16) & 0x1) ? 0x2 : 0;
+ parity |= (nrbits(anac, 8) & 0x1) ? 0x4 : 0;
+ parity |= (nrbits(nacs, 8) & 0x1) ? 0x8 : 0;
+
+ oob.u.a.virtualUnitNo = cpu_to_le16(thisVUC);
+ oob.u.a.prevUnitNo = cpu_to_le16(prev_block);
+ oob.u.a.ANAC = anac;
+ oob.u.a.NACs = nacs;
+ oob.u.a.parityPerField = parity;
+ oob.u.a.discarded = 0xaa;
+
+ inftl_write_oob(mtd, writeEUN * inftl->EraseSize + 8, 8,
+ &retlen, (char *)&oob.u);
+
+ /* Also back up header... */
+ oob.u.b.virtualUnitNo = cpu_to_le16(thisVUC);
+ oob.u.b.prevUnitNo = cpu_to_le16(prev_block);
+ oob.u.b.ANAC = anac;
+ oob.u.b.NACs = nacs;
+ oob.u.b.parityPerField = parity;
+ oob.u.b.discarded = 0xaa;
+
+ inftl_write_oob(mtd, writeEUN * inftl->EraseSize +
+ SECTORSIZE * 4 + 8, 8, &retlen, (char *)&oob.u);
+
+ inftl->PUtable[writeEUN] = inftl->VUtable[thisVUC];
+ inftl->VUtable[thisVUC] = writeEUN;
+
+ inftl->numfreeEUNs--;
+ return writeEUN;
+
+ } while (silly2--);
+
+ printk(KERN_WARNING "INFTL: error folding to make room for Virtual "
+ "Unit Chain 0x%x\n", thisVUC);
+ return BLOCK_NIL;
+}
+
+/*
+ * Given a Virtual Unit Chain, see if it can be deleted, and if so do it.
+ */
+static void INFTL_trydeletechain(struct INFTLrecord *inftl, unsigned thisVUC)
+{
+ struct mtd_info *mtd = inftl->mbd.mtd;
+ unsigned char BlockUsed[MAX_SECTORS_PER_UNIT];
+ unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
+ unsigned int thisEUN, status;
+ int block, silly;
+ struct inftl_bci bci;
+ size_t retlen;
+
+ pr_debug("INFTL: INFTL_trydeletechain(inftl=%p,"
+ "thisVUC=%d)\n", inftl, thisVUC);
+
+ memset(BlockUsed, 0, sizeof(BlockUsed));
+ memset(BlockDeleted, 0, sizeof(BlockDeleted));
+
+ thisEUN = inftl->VUtable[thisVUC];
+ if (thisEUN == BLOCK_NIL) {
+ printk(KERN_WARNING "INFTL: trying to delete non-existent "
+ "Virtual Unit Chain %d!\n", thisVUC);
+ return;
+ }
+
+ /*
+ * Scan through the Erase Units to determine whether any data is in
+ * each of the 512-byte blocks within the Chain.
+ */
+ silly = MAX_LOOPS;
+ while (thisEUN < inftl->nb_blocks) {
+ for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++) {
+ if (BlockUsed[block] || BlockDeleted[block])
+ continue;
+
+ if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize)
+ + (block * SECTORSIZE), 8 , &retlen,
+ (char *)&bci) < 0)
+ status = SECTOR_IGNORE;
+ else
+ status = bci.Status | bci.Status1;
+
+ switch(status) {
+ case SECTOR_FREE:
+ case SECTOR_IGNORE:
+ break;
+ case SECTOR_USED:
+ BlockUsed[block] = 1;
+ continue;
+ case SECTOR_DELETED:
+ BlockDeleted[block] = 1;
+ continue;
+ default:
+ printk(KERN_WARNING "INFTL: unknown status "
+ "for block %d in EUN %d: 0x%x\n",
+ block, thisEUN, status);
+ }
+ }
+
+ if (!silly--) {
+ printk(KERN_WARNING "INFTL: infinite loop in Virtual "
+ "Unit Chain 0x%x\n", thisVUC);
+ return;
+ }
+
+ thisEUN = inftl->PUtable[thisEUN];
+ }
+
+ for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++)
+ if (BlockUsed[block])
+ return;
+
+ /*
+ * For each block in the chain free it and make it available
+ * for future use. Erase from the oldest unit first.
+ */
+ pr_debug("INFTL: deleting empty VUC %d\n", thisVUC);
+
+ for (;;) {
+ u16 *prevEUN = &inftl->VUtable[thisVUC];
+ thisEUN = *prevEUN;
+
+ /* If the chain is all gone already, we're done */
+ if (thisEUN == BLOCK_NIL) {
+ pr_debug("INFTL: Empty VUC %d for deletion was already absent\n", thisEUN);
+ return;
+ }
+
+ /* Find oldest unit in chain. */
+ while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
+ BUG_ON(thisEUN >= inftl->nb_blocks);
+
+ prevEUN = &inftl->PUtable[thisEUN];
+ thisEUN = *prevEUN;
+ }
+
+ pr_debug("Deleting EUN %d from VUC %d\n",
+ thisEUN, thisVUC);
+
+ if (INFTL_formatblock(inftl, thisEUN) < 0) {
+ /*
+ * Could not erase : mark block as reserved.
+ */
+ inftl->PUtable[thisEUN] = BLOCK_RESERVED;
+ } else {
+ /* Correctly erased : mark it as free */
+ inftl->PUtable[thisEUN] = BLOCK_FREE;
+ inftl->numfreeEUNs++;
+ }
+
+ /* Now sort out whatever was pointing to it... */
+ *prevEUN = BLOCK_NIL;
+
+ /* Ideally we'd actually be responsive to new
+ requests while we're doing this -- if there's
+ free space why should others be made to wait? */
+ cond_resched();
+ }
+
+ inftl->VUtable[thisVUC] = BLOCK_NIL;
+}
+
+static int INFTL_deleteblock(struct INFTLrecord *inftl, unsigned block)
+{
+ unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
+ unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
+ struct mtd_info *mtd = inftl->mbd.mtd;
+ unsigned int status;
+ int silly = MAX_LOOPS;
+ size_t retlen;
+ struct inftl_bci bci;
+
+ pr_debug("INFTL: INFTL_deleteblock(inftl=%p,"
+ "block=%d)\n", inftl, block);
+
+ while (thisEUN < inftl->nb_blocks) {
+ if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
+ blockofs, 8, &retlen, (char *)&bci) < 0)
+ status = SECTOR_IGNORE;
+ else
+ status = bci.Status | bci.Status1;
+
+ switch (status) {
+ case SECTOR_FREE:
+ case SECTOR_IGNORE:
+ break;
+ case SECTOR_DELETED:
+ thisEUN = BLOCK_NIL;
+ goto foundit;
+ case SECTOR_USED:
+ goto foundit;
+ default:
+ printk(KERN_WARNING "INFTL: unknown status for "
+ "block %d in EUN %d: 0x%x\n",
+ block, thisEUN, status);
+ break;
+ }
+
+ if (!silly--) {
+ printk(KERN_WARNING "INFTL: infinite loop in Virtual "
+ "Unit Chain 0x%x\n",
+ block / (inftl->EraseSize / SECTORSIZE));
+ return 1;
+ }
+ thisEUN = inftl->PUtable[thisEUN];
+ }
+
+foundit:
+ if (thisEUN != BLOCK_NIL) {
+ loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
+
+ if (inftl_read_oob(mtd, ptr, 8, &retlen, (char *)&bci) < 0)
+ return -EIO;
+ bci.Status = bci.Status1 = SECTOR_DELETED;
+ if (inftl_write_oob(mtd, ptr, 8, &retlen, (char *)&bci) < 0)
+ return -EIO;
+ INFTL_trydeletechain(inftl, block / (inftl->EraseSize / SECTORSIZE));
+ }
+ return 0;
+}
+
+static int inftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block,
+ char *buffer)
+{
+ struct INFTLrecord *inftl = (void *)mbd;
+ unsigned int writeEUN;
+ unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
+ size_t retlen;
+ struct inftl_oob oob;
+ char *p, *pend;
+
+ pr_debug("INFTL: inftl_writeblock(inftl=%p,block=%ld,"
+ "buffer=%p)\n", inftl, block, buffer);
+
+ /* Is block all zero? */
+ pend = buffer + SECTORSIZE;
+ for (p = buffer; p < pend && !*p; p++)
+ ;
+
+ if (p < pend) {
+ writeEUN = INFTL_findwriteunit(inftl, block);
+
+ if (writeEUN == BLOCK_NIL) {
+ printk(KERN_WARNING "inftl_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 inftl_oob));
+ oob.b.Status = oob.b.Status1 = SECTOR_USED;
+
+ inftl_write(inftl->mbd.mtd, (writeEUN * inftl->EraseSize) +
+ blockofs, SECTORSIZE, &retlen, (char *)buffer,
+ (char *)&oob);
+ /*
+ * need to write SECTOR_USED flags since they are not written
+ * in mtd_writeecc
+ */
+ } else {
+ INFTL_deleteblock(inftl, block);
+ }
+
+ return 0;
+}
+
+static int inftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block,
+ char *buffer)
+{
+ struct INFTLrecord *inftl = (void *)mbd;
+ unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
+ unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
+ struct mtd_info *mtd = inftl->mbd.mtd;
+ unsigned int status;
+ int silly = MAX_LOOPS;
+ struct inftl_bci bci;
+ size_t retlen;
+
+ pr_debug("INFTL: inftl_readblock(inftl=%p,block=%ld,"
+ "buffer=%p)\n", inftl, block, buffer);
+
+ while (thisEUN < inftl->nb_blocks) {
+ if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
+ blockofs, 8, &retlen, (char *)&bci) < 0)
+ status = SECTOR_IGNORE;
+ else
+ status = bci.Status | bci.Status1;
+
+ switch (status) {
+ case SECTOR_DELETED:
+ thisEUN = BLOCK_NIL;
+ goto foundit;
+ case SECTOR_USED:
+ goto foundit;
+ case SECTOR_FREE:
+ case SECTOR_IGNORE:
+ break;
+ default:
+ printk(KERN_WARNING "INFTL: unknown status for "
+ "block %ld in EUN %d: 0x%04x\n",
+ block, thisEUN, status);
+ break;
+ }
+
+ if (!silly--) {
+ printk(KERN_WARNING "INFTL: infinite loop in "
+ "Virtual Unit Chain 0x%lx\n",
+ block / (inftl->EraseSize / SECTORSIZE));
+ return 1;
+ }
+
+ thisEUN = inftl->PUtable[thisEUN];
+ }
+
+foundit:
+ if (thisEUN == BLOCK_NIL) {
+ /* The requested block is not on the media, return all 0x00 */
+ memset(buffer, 0, SECTORSIZE);
+ } else {
+ size_t retlen;
+ loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
+ int ret = mtd_read(mtd, ptr, SECTORSIZE, &retlen, buffer);
+
+ /* Handle corrected bit flips gracefully */
+ if (ret < 0 && !mtd_is_bitflip(ret))
+ return -EIO;
+ }
+ return 0;
+}
+
+static int inftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
+{
+ struct INFTLrecord *inftl = (void *)dev;
+
+ geo->heads = inftl->heads;
+ geo->sectors = inftl->sectors;
+ geo->cylinders = inftl->cylinders;
+
+ return 0;
+}
+
+static struct mtd_blktrans_ops inftl_tr = {
+ .name = "inftl",
+ .major = INFTL_MAJOR,
+ .part_bits = INFTL_PARTN_BITS,
+ .blksize = 512,
+ .getgeo = inftl_getgeo,
+ .readsect = inftl_readblock,
+ .writesect = inftl_writeblock,
+ .add_mtd = inftl_add_mtd,
+ .remove_dev = inftl_remove_dev,
+ .owner = THIS_MODULE,
+};
+
+static int __init init_inftl(void)
+{
+ return register_mtd_blktrans(&inftl_tr);
+}
+
+static void __exit cleanup_inftl(void)
+{
+ deregister_mtd_blktrans(&inftl_tr);
+}
+
+module_init(init_inftl);
+module_exit(cleanup_inftl);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>, David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al.");
+MODULE_DESCRIPTION("Support code for Inverse Flash Translation Layer, used on M-Systems DiskOnChip 2000, Millennium and Millennium Plus");
Code Review / kvmfornfv.git / blobdiff