diff options
Diffstat (limited to 'drivers/mtd/inftlcore.c')
| -rw-r--r-- | drivers/mtd/inftlcore.c | 955 |
1 files changed, 955 insertions, 0 deletions
diff --git a/drivers/mtd/inftlcore.c b/drivers/mtd/inftlcore.c new file mode 100644 index 000000000..a0d6c00e7 --- /dev/null +++ b/drivers/mtd/inftlcore.c @@ -0,0 +1,955 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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> + */ + +#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/rawnand.h> +#include <linux/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"); |