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->mbd.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_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) {
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->mbd.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_READ(nftl->mbd.mtd, (nftl->EraseSize * BlockMap[block]) + (block * 512),
512, &retlen, movebuf);
if (ret < 0) {
ret = MTD_READ(nftl->mbd.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;
MTD_WRITEECC(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) + (block * 512),
512, &retlen, movebuf, (char *)&oob, &nftl->oobinfo);
}
/* 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->mbd.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
*/
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;
}
/* 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->mbd.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->mbd.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->mbd.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->mbd.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->mbd.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;
}
/*
* 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 inftl_oob oob;
struct inftl_bci bci;
unsigned char anac, nacs, parity;
size_t retlen;
int silly, silly2 = 3;
DEBUG(MTD_DEBUG_LEVEL3, "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) {
MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize) +
blockofs, 8, &retlen, (char *)&bci);
status = bci.Status | bci.Status1;
DEBUG(MTD_DEBUG_LEVEL3, "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 0xffff;
}
/* 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, 0xffff);
/*
* Hopefully we free something, lets try again.
* This time we are desperate...
*/
DEBUG(MTD_DEBUG_LEVEL1, "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) {
MTD_READOOB(inftl->mbd.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;
MTD_WRITEOOB(inftl->mbd.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;
MTD_WRITEOOB(inftl->mbd.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 0xffff;
}
