xref: /openbmc/linux/drivers/mtd/inftlmount.c (revision a1e58bbd)
1 /*
2  * inftlmount.c -- INFTL mount code with extensive checks.
3  *
4  * Author: Greg Ungerer (gerg@snapgear.com)
5  * (C) Copyright 2002-2003, Greg Ungerer (gerg@snapgear.com)
6  *
7  * Based heavily on the nftlmount.c code which is:
8  * Author: Fabrice Bellard (fabrice.bellard@netgem.com)
9  * Copyright (C) 2000 Netgem S.A.
10  *
11  * $Id: inftlmount.c,v 1.18 2005/11/07 11:14:20 gleixner Exp $
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
26  */
27 
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <asm/errno.h>
31 #include <asm/io.h>
32 #include <asm/uaccess.h>
33 #include <linux/miscdevice.h>
34 #include <linux/delay.h>
35 #include <linux/slab.h>
36 #include <linux/init.h>
37 #include <linux/mtd/mtd.h>
38 #include <linux/mtd/nftl.h>
39 #include <linux/mtd/inftl.h>
40 #include <linux/mtd/compatmac.h>
41 
42 char inftlmountrev[]="$Revision: 1.18 $";
43 
44 extern int inftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
45 			  size_t *retlen, uint8_t *buf);
46 extern int inftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
47 			   size_t *retlen, uint8_t *buf);
48 
49 /*
50  * find_boot_record: Find the INFTL Media Header and its Spare copy which
51  *	contains the various device information of the INFTL partition and
52  *	Bad Unit Table. Update the PUtable[] table according to the Bad
53  *	Unit Table. PUtable[] is used for management of Erase Unit in
54  *	other routines in inftlcore.c and inftlmount.c.
55  */
56 static int find_boot_record(struct INFTLrecord *inftl)
57 {
58 	struct inftl_unittail h1;
59 	//struct inftl_oob oob;
60 	unsigned int i, block;
61 	u8 buf[SECTORSIZE];
62 	struct INFTLMediaHeader *mh = &inftl->MediaHdr;
63 	struct mtd_info *mtd = inftl->mbd.mtd;
64 	struct INFTLPartition *ip;
65 	size_t retlen;
66 
67 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: find_boot_record(inftl=%p)\n", inftl);
68 
69         /*
70 	 * Assume logical EraseSize == physical erasesize for starting the
71 	 * scan. We'll sort it out later if we find a MediaHeader which says
72 	 * otherwise.
73 	 */
74 	inftl->EraseSize = inftl->mbd.mtd->erasesize;
75         inftl->nb_blocks = inftl->mbd.mtd->size / inftl->EraseSize;
76 
77 	inftl->MediaUnit = BLOCK_NIL;
78 
79 	/* Search for a valid boot record */
80 	for (block = 0; block < inftl->nb_blocks; block++) {
81 		int ret;
82 
83 		/*
84 		 * Check for BNAND header first. Then whinge if it's found
85 		 * but later checks fail.
86 		 */
87 		ret = mtd->read(mtd, block * inftl->EraseSize,
88 				SECTORSIZE, &retlen, buf);
89 		/* We ignore ret in case the ECC of the MediaHeader is invalid
90 		   (which is apparently acceptable) */
91 		if (retlen != SECTORSIZE) {
92 			static int warncount = 5;
93 
94 			if (warncount) {
95 				printk(KERN_WARNING "INFTL: block read at 0x%x "
96 					"of mtd%d failed: %d\n",
97 					block * inftl->EraseSize,
98 					inftl->mbd.mtd->index, ret);
99 				if (!--warncount)
100 					printk(KERN_WARNING "INFTL: further "
101 						"failures for this block will "
102 						"not be printed\n");
103 			}
104 			continue;
105 		}
106 
107 		if (retlen < 6 || memcmp(buf, "BNAND", 6)) {
108 			/* BNAND\0 not found. Continue */
109 			continue;
110 		}
111 
112 		/* To be safer with BIOS, also use erase mark as discriminant */
113 		if ((ret = inftl_read_oob(mtd, block * inftl->EraseSize +
114 					  SECTORSIZE + 8, 8, &retlen,
115 					  (char *)&h1) < 0)) {
116 			printk(KERN_WARNING "INFTL: ANAND header found at "
117 				"0x%x in mtd%d, but OOB data read failed "
118 				"(err %d)\n", block * inftl->EraseSize,
119 				inftl->mbd.mtd->index, ret);
120 			continue;
121 		}
122 
123 
124 		/*
125 		 * This is the first we've seen.
126 		 * Copy the media header structure into place.
127 		 */
128 		memcpy(mh, buf, sizeof(struct INFTLMediaHeader));
129 
130 		/* Read the spare media header at offset 4096 */
131 		mtd->read(mtd, block * inftl->EraseSize + 4096,
132 			  SECTORSIZE, &retlen, buf);
133 		if (retlen != SECTORSIZE) {
134 			printk(KERN_WARNING "INFTL: Unable to read spare "
135 			       "Media Header\n");
136 			return -1;
137 		}
138 		/* Check if this one is the same as the first one we found. */
139 		if (memcmp(mh, buf, sizeof(struct INFTLMediaHeader))) {
140 			printk(KERN_WARNING "INFTL: Primary and spare Media "
141 			       "Headers disagree.\n");
142 			return -1;
143 		}
144 
145 		mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
146 		mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
147 		mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
148 		mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
149 		mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
150 		mh->PercentUsed = le32_to_cpu(mh->PercentUsed);
151 
152 #ifdef CONFIG_MTD_DEBUG_VERBOSE
153 		if (CONFIG_MTD_DEBUG_VERBOSE >= 2) {
154 			printk("INFTL: Media Header ->\n"
155 				"    bootRecordID          = %s\n"
156 				"    NoOfBootImageBlocks   = %d\n"
157 				"    NoOfBinaryPartitions  = %d\n"
158 				"    NoOfBDTLPartitions    = %d\n"
159 				"    BlockMultiplerBits    = %d\n"
160 				"    FormatFlgs            = %d\n"
161 				"    OsakVersion           = 0x%x\n"
162 				"    PercentUsed           = %d\n",
163 				mh->bootRecordID, mh->NoOfBootImageBlocks,
164 				mh->NoOfBinaryPartitions,
165 				mh->NoOfBDTLPartitions,
166 				mh->BlockMultiplierBits, mh->FormatFlags,
167 				mh->OsakVersion, mh->PercentUsed);
168 		}
169 #endif
170 
171 		if (mh->NoOfBDTLPartitions == 0) {
172 			printk(KERN_WARNING "INFTL: Media Header sanity check "
173 				"failed: NoOfBDTLPartitions (%d) == 0, "
174 				"must be at least 1\n", mh->NoOfBDTLPartitions);
175 			return -1;
176 		}
177 
178 		if ((mh->NoOfBDTLPartitions + mh->NoOfBinaryPartitions) > 4) {
179 			printk(KERN_WARNING "INFTL: Media Header sanity check "
180 				"failed: Total Partitions (%d) > 4, "
181 				"BDTL=%d Binary=%d\n", mh->NoOfBDTLPartitions +
182 				mh->NoOfBinaryPartitions,
183 				mh->NoOfBDTLPartitions,
184 				mh->NoOfBinaryPartitions);
185 			return -1;
186 		}
187 
188 		if (mh->BlockMultiplierBits > 1) {
189 			printk(KERN_WARNING "INFTL: sorry, we don't support "
190 				"UnitSizeFactor 0x%02x\n",
191 				mh->BlockMultiplierBits);
192 			return -1;
193 		} else if (mh->BlockMultiplierBits == 1) {
194 			printk(KERN_WARNING "INFTL: support for INFTL with "
195 				"UnitSizeFactor 0x%02x is experimental\n",
196 				mh->BlockMultiplierBits);
197 			inftl->EraseSize = inftl->mbd.mtd->erasesize <<
198 				mh->BlockMultiplierBits;
199 			inftl->nb_blocks = inftl->mbd.mtd->size / inftl->EraseSize;
200 			block >>= mh->BlockMultiplierBits;
201 		}
202 
203 		/* Scan the partitions */
204 		for (i = 0; (i < 4); i++) {
205 			ip = &mh->Partitions[i];
206 			ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
207 			ip->firstUnit = le32_to_cpu(ip->firstUnit);
208 			ip->lastUnit = le32_to_cpu(ip->lastUnit);
209 			ip->flags = le32_to_cpu(ip->flags);
210 			ip->spareUnits = le32_to_cpu(ip->spareUnits);
211 			ip->Reserved0 = le32_to_cpu(ip->Reserved0);
212 
213 #ifdef CONFIG_MTD_DEBUG_VERBOSE
214 			if (CONFIG_MTD_DEBUG_VERBOSE >= 2) {
215 				printk("    PARTITION[%d] ->\n"
216 					"        virtualUnits    = %d\n"
217 					"        firstUnit       = %d\n"
218 					"        lastUnit        = %d\n"
219 					"        flags           = 0x%x\n"
220 					"        spareUnits      = %d\n",
221 					i, ip->virtualUnits, ip->firstUnit,
222 					ip->lastUnit, ip->flags,
223 					ip->spareUnits);
224 			}
225 #endif
226 
227 			if (ip->Reserved0 != ip->firstUnit) {
228 				struct erase_info *instr = &inftl->instr;
229 
230 				instr->mtd = inftl->mbd.mtd;
231 
232 				/*
233 				 * 	Most likely this is using the
234 				 * 	undocumented qiuck mount feature.
235 				 * 	We don't support that, we will need
236 				 * 	to erase the hidden block for full
237 				 * 	compatibility.
238 				 */
239 				instr->addr = ip->Reserved0 * inftl->EraseSize;
240 				instr->len = inftl->EraseSize;
241 				mtd->erase(mtd, instr);
242 			}
243 			if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
244 				printk(KERN_WARNING "INFTL: Media Header "
245 					"Partition %d sanity check failed\n"
246 					"    firstUnit %d : lastUnit %d  >  "
247 					"virtualUnits %d\n", i, ip->lastUnit,
248 					ip->firstUnit, ip->Reserved0);
249 				return -1;
250 			}
251 			if (ip->Reserved1 != 0) {
252 				printk(KERN_WARNING "INFTL: Media Header "
253 					"Partition %d sanity check failed: "
254 					"Reserved1 %d != 0\n",
255 					i, ip->Reserved1);
256 				return -1;
257 			}
258 
259 			if (ip->flags & INFTL_BDTL)
260 				break;
261 		}
262 
263 		if (i >= 4) {
264 			printk(KERN_WARNING "INFTL: Media Header Partition "
265 				"sanity check failed:\n       No partition "
266 				"marked as Disk Partition\n");
267 			return -1;
268 		}
269 
270 		inftl->nb_boot_blocks = ip->firstUnit;
271 		inftl->numvunits = ip->virtualUnits;
272 		if (inftl->numvunits > (inftl->nb_blocks -
273 		    inftl->nb_boot_blocks - 2)) {
274 			printk(KERN_WARNING "INFTL: Media Header sanity check "
275 				"failed:\n        numvunits (%d) > nb_blocks "
276 				"(%d) - nb_boot_blocks(%d) - 2\n",
277 				inftl->numvunits, inftl->nb_blocks,
278 				inftl->nb_boot_blocks);
279 			return -1;
280 		}
281 
282 		inftl->mbd.size  = inftl->numvunits *
283 			(inftl->EraseSize / SECTORSIZE);
284 
285 		/*
286 		 * Block count is set to last used EUN (we won't need to keep
287 		 * any meta-data past that point).
288 		 */
289 		inftl->firstEUN = ip->firstUnit;
290 		inftl->lastEUN = ip->lastUnit;
291 		inftl->nb_blocks = ip->lastUnit + 1;
292 
293 		/* Memory alloc */
294 		inftl->PUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
295 		if (!inftl->PUtable) {
296 			printk(KERN_WARNING "INFTL: allocation of PUtable "
297 				"failed (%zd bytes)\n",
298 				inftl->nb_blocks * sizeof(u16));
299 			return -ENOMEM;
300 		}
301 
302 		inftl->VUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
303 		if (!inftl->VUtable) {
304 			kfree(inftl->PUtable);
305 			printk(KERN_WARNING "INFTL: allocation of VUtable "
306 				"failed (%zd bytes)\n",
307 				inftl->nb_blocks * sizeof(u16));
308 			return -ENOMEM;
309 		}
310 
311 		/* Mark the blocks before INFTL MediaHeader as reserved */
312 		for (i = 0; i < inftl->nb_boot_blocks; i++)
313 			inftl->PUtable[i] = BLOCK_RESERVED;
314 		/* Mark all remaining blocks as potentially containing data */
315 		for (; i < inftl->nb_blocks; i++)
316 			inftl->PUtable[i] = BLOCK_NOTEXPLORED;
317 
318 		/* Mark this boot record (NFTL MediaHeader) block as reserved */
319 		inftl->PUtable[block] = BLOCK_RESERVED;
320 
321 		/* Read Bad Erase Unit Table and modify PUtable[] accordingly */
322 		for (i = 0; i < inftl->nb_blocks; i++) {
323 			int physblock;
324 			/* If any of the physical eraseblocks are bad, don't
325 			   use the unit. */
326 			for (physblock = 0; physblock < inftl->EraseSize; physblock += inftl->mbd.mtd->erasesize) {
327 				if (inftl->mbd.mtd->block_isbad(inftl->mbd.mtd, i * inftl->EraseSize + physblock))
328 					inftl->PUtable[i] = BLOCK_RESERVED;
329 			}
330 		}
331 
332 		inftl->MediaUnit = block;
333 		return 0;
334 	}
335 
336 	/* Not found. */
337 	return -1;
338 }
339 
340 static int memcmpb(void *a, int c, int n)
341 {
342 	int i;
343 	for (i = 0; i < n; i++) {
344 		if (c != ((unsigned char *)a)[i])
345 			return 1;
346 	}
347 	return 0;
348 }
349 
350 /*
351  * check_free_sector: check if a free sector is actually FREE,
352  *	i.e. All 0xff in data and oob area.
353  */
354 static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
355 	int len, int check_oob)
356 {
357 	u8 buf[SECTORSIZE + inftl->mbd.mtd->oobsize];
358 	struct mtd_info *mtd = inftl->mbd.mtd;
359 	size_t retlen;
360 	int i;
361 
362 	for (i = 0; i < len; i += SECTORSIZE) {
363 		if (mtd->read(mtd, address, SECTORSIZE, &retlen, buf))
364 			return -1;
365 		if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
366 			return -1;
367 
368 		if (check_oob) {
369 			if(inftl_read_oob(mtd, address, mtd->oobsize,
370 					  &retlen, &buf[SECTORSIZE]) < 0)
371 				return -1;
372 			if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
373 				return -1;
374 		}
375 		address += SECTORSIZE;
376 	}
377 
378 	return 0;
379 }
380 
381 /*
382  * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
383  *		 Unit and Update INFTL metadata. Each erase operation is
384  *		 checked with check_free_sectors.
385  *
386  * Return: 0 when succeed, -1 on error.
387  *
388  * ToDo: 1. Is it neceressary to check_free_sector after erasing ??
389  */
390 int INFTL_formatblock(struct INFTLrecord *inftl, int block)
391 {
392 	size_t retlen;
393 	struct inftl_unittail uci;
394 	struct erase_info *instr = &inftl->instr;
395 	struct mtd_info *mtd = inftl->mbd.mtd;
396 	int physblock;
397 
398 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_formatblock(inftl=%p,"
399 		"block=%d)\n", inftl, block);
400 
401 	memset(instr, 0, sizeof(struct erase_info));
402 
403 	/* FIXME: Shouldn't we be setting the 'discarded' flag to zero
404 	   _first_? */
405 
406 	/* Use async erase interface, test return code */
407 	instr->mtd = inftl->mbd.mtd;
408 	instr->addr = block * inftl->EraseSize;
409 	instr->len = inftl->mbd.mtd->erasesize;
410 	/* Erase one physical eraseblock at a time, even though the NAND api
411 	   allows us to group them.  This way we if we have a failure, we can
412 	   mark only the failed block in the bbt. */
413 	for (physblock = 0; physblock < inftl->EraseSize;
414 	     physblock += instr->len, instr->addr += instr->len) {
415 		mtd->erase(inftl->mbd.mtd, instr);
416 
417 		if (instr->state == MTD_ERASE_FAILED) {
418 			printk(KERN_WARNING "INFTL: error while formatting block %d\n",
419 				block);
420 			goto fail;
421 		}
422 
423 		/*
424 		 * Check the "freeness" of Erase Unit before updating metadata.
425 		 * FixMe: is this check really necessary? Since we have check
426 		 * the return code after the erase operation.
427 		 */
428 		if (check_free_sectors(inftl, instr->addr, instr->len, 1) != 0)
429 			goto fail;
430 	}
431 
432 	uci.EraseMark = cpu_to_le16(ERASE_MARK);
433 	uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
434 	uci.Reserved[0] = 0;
435 	uci.Reserved[1] = 0;
436 	uci.Reserved[2] = 0;
437 	uci.Reserved[3] = 0;
438 	instr->addr = block * inftl->EraseSize + SECTORSIZE * 2;
439 	if (inftl_write_oob(mtd, instr->addr + 8, 8, &retlen, (char *)&uci) < 0)
440 		goto fail;
441 	return 0;
442 fail:
443 	/* could not format, update the bad block table (caller is responsible
444 	   for setting the PUtable to BLOCK_RESERVED on failure) */
445 	inftl->mbd.mtd->block_markbad(inftl->mbd.mtd, instr->addr);
446 	return -1;
447 }
448 
449 /*
450  * format_chain: Format an invalid Virtual Unit chain. It frees all the Erase
451  *	Units in a Virtual Unit Chain, i.e. all the units are disconnected.
452  *
453  *	Since the chain is invalid then we will have to erase it from its
454  *	head (normally for INFTL we go from the oldest). But if it has a
455  *	loop then there is no oldest...
456  */
457 static void format_chain(struct INFTLrecord *inftl, unsigned int first_block)
458 {
459 	unsigned int block = first_block, block1;
460 
461 	printk(KERN_WARNING "INFTL: formatting chain at block %d\n",
462 		first_block);
463 
464 	for (;;) {
465 		block1 = inftl->PUtable[block];
466 
467 		printk(KERN_WARNING "INFTL: formatting block %d\n", block);
468 		if (INFTL_formatblock(inftl, block) < 0) {
469 			/*
470 			 * Cannot format !!!! Mark it as Bad Unit,
471 			 */
472 			inftl->PUtable[block] = BLOCK_RESERVED;
473 		} else {
474 			inftl->PUtable[block] = BLOCK_FREE;
475 		}
476 
477 		/* Goto next block on the chain */
478 		block = block1;
479 
480 		if (block == BLOCK_NIL || block >= inftl->lastEUN)
481 			break;
482 	}
483 }
484 
485 void INFTL_dumptables(struct INFTLrecord *s)
486 {
487 	int i;
488 
489 	printk("-------------------------------------------"
490 		"----------------------------------\n");
491 
492 	printk("VUtable[%d] ->", s->nb_blocks);
493 	for (i = 0; i < s->nb_blocks; i++) {
494 		if ((i % 8) == 0)
495 			printk("\n%04x: ", i);
496 		printk("%04x ", s->VUtable[i]);
497 	}
498 
499 	printk("\n-------------------------------------------"
500 		"----------------------------------\n");
501 
502 	printk("PUtable[%d-%d=%d] ->", s->firstEUN, s->lastEUN, s->nb_blocks);
503 	for (i = 0; i <= s->lastEUN; i++) {
504 		if ((i % 8) == 0)
505 			printk("\n%04x: ", i);
506 		printk("%04x ", s->PUtable[i]);
507 	}
508 
509 	printk("\n-------------------------------------------"
510 		"----------------------------------\n");
511 
512 	printk("INFTL ->\n"
513 		"  EraseSize       = %d\n"
514 		"  h/s/c           = %d/%d/%d\n"
515 		"  numvunits       = %d\n"
516 		"  firstEUN        = %d\n"
517 		"  lastEUN         = %d\n"
518 		"  numfreeEUNs     = %d\n"
519 		"  LastFreeEUN     = %d\n"
520 		"  nb_blocks       = %d\n"
521 		"  nb_boot_blocks  = %d",
522 		s->EraseSize, s->heads, s->sectors, s->cylinders,
523 		s->numvunits, s->firstEUN, s->lastEUN, s->numfreeEUNs,
524 		s->LastFreeEUN, s->nb_blocks, s->nb_boot_blocks);
525 
526 	printk("\n-------------------------------------------"
527 		"----------------------------------\n");
528 }
529 
530 void INFTL_dumpVUchains(struct INFTLrecord *s)
531 {
532 	int logical, block, i;
533 
534 	printk("-------------------------------------------"
535 		"----------------------------------\n");
536 
537 	printk("INFTL Virtual Unit Chains:\n");
538 	for (logical = 0; logical < s->nb_blocks; logical++) {
539 		block = s->VUtable[logical];
540 		if (block > s->nb_blocks)
541 			continue;
542 		printk("  LOGICAL %d --> %d ", logical, block);
543 		for (i = 0; i < s->nb_blocks; i++) {
544 			if (s->PUtable[block] == BLOCK_NIL)
545 				break;
546 			block = s->PUtable[block];
547 			printk("%d ", block);
548 		}
549 		printk("\n");
550 	}
551 
552 	printk("-------------------------------------------"
553 		"----------------------------------\n");
554 }
555 
556 int INFTL_mount(struct INFTLrecord *s)
557 {
558 	struct mtd_info *mtd = s->mbd.mtd;
559 	unsigned int block, first_block, prev_block, last_block;
560 	unsigned int first_logical_block, logical_block, erase_mark;
561 	int chain_length, do_format_chain;
562 	struct inftl_unithead1 h0;
563 	struct inftl_unittail h1;
564 	size_t retlen;
565 	int i;
566 	u8 *ANACtable, ANAC;
567 
568 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_mount(inftl=%p)\n", s);
569 
570 	/* Search for INFTL MediaHeader and Spare INFTL Media Header */
571 	if (find_boot_record(s) < 0) {
572 		printk(KERN_WARNING "INFTL: could not find valid boot record?\n");
573 		return -ENXIO;
574 	}
575 
576 	/* Init the logical to physical table */
577 	for (i = 0; i < s->nb_blocks; i++)
578 		s->VUtable[i] = BLOCK_NIL;
579 
580 	logical_block = block = BLOCK_NIL;
581 
582 	/* Temporary buffer to store ANAC numbers. */
583 	ANACtable = kcalloc(s->nb_blocks, sizeof(u8), GFP_KERNEL);
584 	if (!ANACtable) {
585 		printk(KERN_WARNING "INFTL: allocation of ANACtable "
586 				"failed (%zd bytes)\n",
587 				s->nb_blocks * sizeof(u8));
588 		return -ENOMEM;
589 	}
590 
591 	/*
592 	 * First pass is to explore each physical unit, and construct the
593 	 * virtual chains that exist (newest physical unit goes into VUtable).
594 	 * Any block that is in any way invalid will be left in the
595 	 * NOTEXPLORED state. Then at the end we will try to format it and
596 	 * mark it as free.
597 	 */
598 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: pass 1, explore each unit\n");
599 	for (first_block = s->firstEUN; first_block <= s->lastEUN; first_block++) {
600 		if (s->PUtable[first_block] != BLOCK_NOTEXPLORED)
601 			continue;
602 
603 		do_format_chain = 0;
604 		first_logical_block = BLOCK_NIL;
605 		last_block = BLOCK_NIL;
606 		block = first_block;
607 
608 		for (chain_length = 0; ; chain_length++) {
609 
610 			if ((chain_length == 0) &&
611 			    (s->PUtable[block] != BLOCK_NOTEXPLORED)) {
612 				/* Nothing to do here, onto next block */
613 				break;
614 			}
615 
616 			if (inftl_read_oob(mtd, block * s->EraseSize + 8,
617 					   8, &retlen, (char *)&h0) < 0 ||
618 			    inftl_read_oob(mtd, block * s->EraseSize +
619 					   2 * SECTORSIZE + 8, 8, &retlen,
620 					   (char *)&h1) < 0) {
621 				/* Should never happen? */
622 				do_format_chain++;
623 				break;
624 			}
625 
626 			logical_block = le16_to_cpu(h0.virtualUnitNo);
627 			prev_block = le16_to_cpu(h0.prevUnitNo);
628 			erase_mark = le16_to_cpu((h1.EraseMark | h1.EraseMark1));
629 			ANACtable[block] = h0.ANAC;
630 
631 			/* Previous block is relative to start of Partition */
632 			if (prev_block < s->nb_blocks)
633 				prev_block += s->firstEUN;
634 
635 			/* Already explored partial chain? */
636 			if (s->PUtable[block] != BLOCK_NOTEXPLORED) {
637 				/* Check if chain for this logical */
638 				if (logical_block == first_logical_block) {
639 					if (last_block != BLOCK_NIL)
640 						s->PUtable[last_block] = block;
641 				}
642 				break;
643 			}
644 
645 			/* Check for invalid block */
646 			if (erase_mark != ERASE_MARK) {
647 				printk(KERN_WARNING "INFTL: corrupt block %d "
648 					"in chain %d, chain length %d, erase "
649 					"mark 0x%x?\n", block, first_block,
650 					chain_length, erase_mark);
651 				/*
652 				 * Assume end of chain, probably incomplete
653 				 * fold/erase...
654 				 */
655 				if (chain_length == 0)
656 					do_format_chain++;
657 				break;
658 			}
659 
660 			/* Check for it being free already then... */
661 			if ((logical_block == BLOCK_FREE) ||
662 			    (logical_block == BLOCK_NIL)) {
663 				s->PUtable[block] = BLOCK_FREE;
664 				break;
665 			}
666 
667 			/* Sanity checks on block numbers */
668 			if ((logical_block >= s->nb_blocks) ||
669 			    ((prev_block >= s->nb_blocks) &&
670 			     (prev_block != BLOCK_NIL))) {
671 				if (chain_length > 0) {
672 					printk(KERN_WARNING "INFTL: corrupt "
673 						"block %d in chain %d?\n",
674 						block, first_block);
675 					do_format_chain++;
676 				}
677 				break;
678 			}
679 
680 			if (first_logical_block == BLOCK_NIL) {
681 				first_logical_block = logical_block;
682 			} else {
683 				if (first_logical_block != logical_block) {
684 					/* Normal for folded chain... */
685 					break;
686 				}
687 			}
688 
689 			/*
690 			 * Current block is valid, so if we followed a virtual
691 			 * chain to get here then we can set the previous
692 			 * block pointer in our PUtable now. Then move onto
693 			 * the previous block in the chain.
694 			 */
695 			s->PUtable[block] = BLOCK_NIL;
696 			if (last_block != BLOCK_NIL)
697 				s->PUtable[last_block] = block;
698 			last_block = block;
699 			block = prev_block;
700 
701 			/* Check for end of chain */
702 			if (block == BLOCK_NIL)
703 				break;
704 
705 			/* Validate next block before following it... */
706 			if (block > s->lastEUN) {
707 				printk(KERN_WARNING "INFTL: invalid previous "
708 					"block %d in chain %d?\n", block,
709 					first_block);
710 				do_format_chain++;
711 				break;
712 			}
713 		}
714 
715 		if (do_format_chain) {
716 			format_chain(s, first_block);
717 			continue;
718 		}
719 
720 		/*
721 		 * Looks like a valid chain then. It may not really be the
722 		 * newest block in the chain, but it is the newest we have
723 		 * found so far. We might update it in later iterations of
724 		 * this loop if we find something newer.
725 		 */
726 		s->VUtable[first_logical_block] = first_block;
727 		logical_block = BLOCK_NIL;
728 	}
729 
730 #ifdef CONFIG_MTD_DEBUG_VERBOSE
731 	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
732 		INFTL_dumptables(s);
733 #endif
734 
735 	/*
736 	 * Second pass, check for infinite loops in chains. These are
737 	 * possible because we don't update the previous pointers when
738 	 * we fold chains. No big deal, just fix them up in PUtable.
739 	 */
740 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: pass 2, validate virtual chains\n");
741 	for (logical_block = 0; logical_block < s->numvunits; logical_block++) {
742 		block = s->VUtable[logical_block];
743 		last_block = BLOCK_NIL;
744 
745 		/* Check for free/reserved/nil */
746 		if (block >= BLOCK_RESERVED)
747 			continue;
748 
749 		ANAC = ANACtable[block];
750 		for (i = 0; i < s->numvunits; i++) {
751 			if (s->PUtable[block] == BLOCK_NIL)
752 				break;
753 			if (s->PUtable[block] > s->lastEUN) {
754 				printk(KERN_WARNING "INFTL: invalid prev %d, "
755 					"in virtual chain %d\n",
756 					s->PUtable[block], logical_block);
757 				s->PUtable[block] = BLOCK_NIL;
758 
759 			}
760 			if (ANACtable[block] != ANAC) {
761 				/*
762 				 * Chain must point back to itself. This is ok,
763 				 * but we will need adjust the tables with this
764 				 * newest block and oldest block.
765 				 */
766 				s->VUtable[logical_block] = block;
767 				s->PUtable[last_block] = BLOCK_NIL;
768 				break;
769 			}
770 
771 			ANAC--;
772 			last_block = block;
773 			block = s->PUtable[block];
774 		}
775 
776 		if (i >= s->nb_blocks) {
777 			/*
778 			 * Uhoo, infinite chain with valid ANACS!
779 			 * Format whole chain...
780 			 */
781 			format_chain(s, first_block);
782 		}
783 	}
784 
785 #ifdef CONFIG_MTD_DEBUG_VERBOSE
786 	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
787 		INFTL_dumptables(s);
788 	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
789 		INFTL_dumpVUchains(s);
790 #endif
791 
792 	/*
793 	 * Third pass, format unreferenced blocks and init free block count.
794 	 */
795 	s->numfreeEUNs = 0;
796 	s->LastFreeEUN = BLOCK_NIL;
797 
798 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: pass 3, format unused blocks\n");
799 	for (block = s->firstEUN; block <= s->lastEUN; block++) {
800 		if (s->PUtable[block] == BLOCK_NOTEXPLORED) {
801 			printk("INFTL: unreferenced block %d, formatting it\n",
802 				block);
803 			if (INFTL_formatblock(s, block) < 0)
804 				s->PUtable[block] = BLOCK_RESERVED;
805 			else
806 				s->PUtable[block] = BLOCK_FREE;
807 		}
808 		if (s->PUtable[block] == BLOCK_FREE) {
809 			s->numfreeEUNs++;
810 			if (s->LastFreeEUN == BLOCK_NIL)
811 				s->LastFreeEUN = block;
812 		}
813 	}
814 
815 	kfree(ANACtable);
816 	return 0;
817 }
818