xref: /linux/drivers/mtd/inftlmount.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/pci.h>
35 #include <linux/delay.h>
36 #include <linux/slab.h>
37 #include <linux/sched.h>
38 #include <linux/init.h>
39 #include <linux/mtd/mtd.h>
40 #include <linux/mtd/nftl.h>
41 #include <linux/mtd/inftl.h>
42 #include <linux/mtd/compatmac.h>
43 
44 char inftlmountrev[]="$Revision: 1.18 $";
45 
46 extern int inftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
47 			  size_t *retlen, uint8_t *buf);
48 extern int inftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
49 			   size_t *retlen, uint8_t *buf);
50 
51 /*
52  * find_boot_record: Find the INFTL Media Header and its Spare copy which
53  *	contains the various device information of the INFTL partition and
54  *	Bad Unit Table. Update the PUtable[] table according to the Bad
55  *	Unit Table. PUtable[] is used for management of Erase Unit in
56  *	other routines in inftlcore.c and inftlmount.c.
57  */
58 static int find_boot_record(struct INFTLrecord *inftl)
59 {
60 	struct inftl_unittail h1;
61 	//struct inftl_oob oob;
62 	unsigned int i, block;
63 	u8 buf[SECTORSIZE];
64 	struct INFTLMediaHeader *mh = &inftl->MediaHdr;
65 	struct mtd_info *mtd = inftl->mbd.mtd;
66 	struct INFTLPartition *ip;
67 	size_t retlen;
68 
69 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: find_boot_record(inftl=%p)\n", inftl);
70 
71         /*
72 	 * Assume logical EraseSize == physical erasesize for starting the
73 	 * scan. We'll sort it out later if we find a MediaHeader which says
74 	 * otherwise.
75 	 */
76 	inftl->EraseSize = inftl->mbd.mtd->erasesize;
77         inftl->nb_blocks = inftl->mbd.mtd->size / inftl->EraseSize;
78 
79 	inftl->MediaUnit = BLOCK_NIL;
80 
81 	/* Search for a valid boot record */
82 	for (block = 0; block < inftl->nb_blocks; block++) {
83 		int ret;
84 
85 		/*
86 		 * Check for BNAND header first. Then whinge if it's found
87 		 * but later checks fail.
88 		 */
89 		ret = mtd->read(mtd, block * inftl->EraseSize,
90 				SECTORSIZE, &retlen, buf);
91 		/* We ignore ret in case the ECC of the MediaHeader is invalid
92 		   (which is apparently acceptable) */
93 		if (retlen != SECTORSIZE) {
94 			static int warncount = 5;
95 
96 			if (warncount) {
97 				printk(KERN_WARNING "INFTL: block read at 0x%x "
98 					"of mtd%d failed: %d\n",
99 					block * inftl->EraseSize,
100 					inftl->mbd.mtd->index, ret);
101 				if (!--warncount)
102 					printk(KERN_WARNING "INFTL: further "
103 						"failures for this block will "
104 						"not be printed\n");
105 			}
106 			continue;
107 		}
108 
109 		if (retlen < 6 || memcmp(buf, "BNAND", 6)) {
110 			/* BNAND\0 not found. Continue */
111 			continue;
112 		}
113 
114 		/* To be safer with BIOS, also use erase mark as discriminant */
115 		if ((ret = inftl_read_oob(mtd, block * inftl->EraseSize +
116 					  SECTORSIZE + 8, 8, &retlen,
117 					  (char *)&h1) < 0)) {
118 			printk(KERN_WARNING "INFTL: ANAND header found at "
119 				"0x%x in mtd%d, but OOB data read failed "
120 				"(err %d)\n", block * inftl->EraseSize,
121 				inftl->mbd.mtd->index, ret);
122 			continue;
123 		}
124 
125 
126 		/*
127 		 * This is the first we've seen.
128 		 * Copy the media header structure into place.
129 		 */
130 		memcpy(mh, buf, sizeof(struct INFTLMediaHeader));
131 
132 		/* Read the spare media header at offset 4096 */
133 		mtd->read(mtd, block * inftl->EraseSize + 4096,
134 			  SECTORSIZE, &retlen, buf);
135 		if (retlen != SECTORSIZE) {
136 			printk(KERN_WARNING "INFTL: Unable to read spare "
137 			       "Media Header\n");
138 			return -1;
139 		}
140 		/* Check if this one is the same as the first one we found. */
141 		if (memcmp(mh, buf, sizeof(struct INFTLMediaHeader))) {
142 			printk(KERN_WARNING "INFTL: Primary and spare Media "
143 			       "Headers disagree.\n");
144 			return -1;
145 		}
146 
147 		mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
148 		mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
149 		mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
150 		mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
151 		mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
152 		mh->PercentUsed = le32_to_cpu(mh->PercentUsed);
153 
154 #ifdef CONFIG_MTD_DEBUG_VERBOSE
155 		if (CONFIG_MTD_DEBUG_VERBOSE >= 2) {
156 			printk("INFTL: Media Header ->\n"
157 				"    bootRecordID          = %s\n"
158 				"    NoOfBootImageBlocks   = %d\n"
159 				"    NoOfBinaryPartitions  = %d\n"
160 				"    NoOfBDTLPartitions    = %d\n"
161 				"    BlockMultiplerBits    = %d\n"
162 				"    FormatFlgs            = %d\n"
163 				"    OsakVersion           = 0x%x\n"
164 				"    PercentUsed           = %d\n",
165 				mh->bootRecordID, mh->NoOfBootImageBlocks,
166 				mh->NoOfBinaryPartitions,
167 				mh->NoOfBDTLPartitions,
168 				mh->BlockMultiplierBits, mh->FormatFlags,
169 				mh->OsakVersion, mh->PercentUsed);
170 		}
171 #endif
172 
173 		if (mh->NoOfBDTLPartitions == 0) {
174 			printk(KERN_WARNING "INFTL: Media Header sanity check "
175 				"failed: NoOfBDTLPartitions (%d) == 0, "
176 				"must be at least 1\n", mh->NoOfBDTLPartitions);
177 			return -1;
178 		}
179 
180 		if ((mh->NoOfBDTLPartitions + mh->NoOfBinaryPartitions) > 4) {
181 			printk(KERN_WARNING "INFTL: Media Header sanity check "
182 				"failed: Total Partitions (%d) > 4, "
183 				"BDTL=%d Binary=%d\n", mh->NoOfBDTLPartitions +
184 				mh->NoOfBinaryPartitions,
185 				mh->NoOfBDTLPartitions,
186 				mh->NoOfBinaryPartitions);
187 			return -1;
188 		}
189 
190 		if (mh->BlockMultiplierBits > 1) {
191 			printk(KERN_WARNING "INFTL: sorry, we don't support "
192 				"UnitSizeFactor 0x%02x\n",
193 				mh->BlockMultiplierBits);
194 			return -1;
195 		} else if (mh->BlockMultiplierBits == 1) {
196 			printk(KERN_WARNING "INFTL: support for INFTL with "
197 				"UnitSizeFactor 0x%02x is experimental\n",
198 				mh->BlockMultiplierBits);
199 			inftl->EraseSize = inftl->mbd.mtd->erasesize <<
200 				mh->BlockMultiplierBits;
201 			inftl->nb_blocks = inftl->mbd.mtd->size / inftl->EraseSize;
202 			block >>= mh->BlockMultiplierBits;
203 		}
204 
205 		/* Scan the partitions */
206 		for (i = 0; (i < 4); i++) {
207 			ip = &mh->Partitions[i];
208 			ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
209 			ip->firstUnit = le32_to_cpu(ip->firstUnit);
210 			ip->lastUnit = le32_to_cpu(ip->lastUnit);
211 			ip->flags = le32_to_cpu(ip->flags);
212 			ip->spareUnits = le32_to_cpu(ip->spareUnits);
213 			ip->Reserved0 = le32_to_cpu(ip->Reserved0);
214 
215 #ifdef CONFIG_MTD_DEBUG_VERBOSE
216 			if (CONFIG_MTD_DEBUG_VERBOSE >= 2) {
217 				printk("    PARTITION[%d] ->\n"
218 					"        virtualUnits    = %d\n"
219 					"        firstUnit       = %d\n"
220 					"        lastUnit        = %d\n"
221 					"        flags           = 0x%x\n"
222 					"        spareUnits      = %d\n",
223 					i, ip->virtualUnits, ip->firstUnit,
224 					ip->lastUnit, ip->flags,
225 					ip->spareUnits);
226 			}
227 #endif
228 
229 			if (ip->Reserved0 != ip->firstUnit) {
230 				struct erase_info *instr = &inftl->instr;
231 
232 				instr->mtd = inftl->mbd.mtd;
233 
234 				/*
235 				 * 	Most likely this is using the
236 				 * 	undocumented qiuck mount feature.
237 				 * 	We don't support that, we will need
238 				 * 	to erase the hidden block for full
239 				 * 	compatibility.
240 				 */
241 				instr->addr = ip->Reserved0 * inftl->EraseSize;
242 				instr->len = inftl->EraseSize;
243 				mtd->erase(mtd, instr);
244 			}
245 			if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
246 				printk(KERN_WARNING "INFTL: Media Header "
247 					"Partition %d sanity check failed\n"
248 					"    firstUnit %d : lastUnit %d  >  "
249 					"virtualUnits %d\n", i, ip->lastUnit,
250 					ip->firstUnit, ip->Reserved0);
251 				return -1;
252 			}
253 			if (ip->Reserved1 != 0) {
254 				printk(KERN_WARNING "INFTL: Media Header "
255 					"Partition %d sanity check failed: "
256 					"Reserved1 %d != 0\n",
257 					i, ip->Reserved1);
258 				return -1;
259 			}
260 
261 			if (ip->flags & INFTL_BDTL)
262 				break;
263 		}
264 
265 		if (i >= 4) {
266 			printk(KERN_WARNING "INFTL: Media Header Partition "
267 				"sanity check failed:\n       No partition "
268 				"marked as Disk Partition\n");
269 			return -1;
270 		}
271 
272 		inftl->nb_boot_blocks = ip->firstUnit;
273 		inftl->numvunits = ip->virtualUnits;
274 		if (inftl->numvunits > (inftl->nb_blocks -
275 		    inftl->nb_boot_blocks - 2)) {
276 			printk(KERN_WARNING "INFTL: Media Header sanity check "
277 				"failed:\n        numvunits (%d) > nb_blocks "
278 				"(%d) - nb_boot_blocks(%d) - 2\n",
279 				inftl->numvunits, inftl->nb_blocks,
280 				inftl->nb_boot_blocks);
281 			return -1;
282 		}
283 
284 		inftl->mbd.size  = inftl->numvunits *
285 			(inftl->EraseSize / SECTORSIZE);
286 
287 		/*
288 		 * Block count is set to last used EUN (we won't need to keep
289 		 * any meta-data past that point).
290 		 */
291 		inftl->firstEUN = ip->firstUnit;
292 		inftl->lastEUN = ip->lastUnit;
293 		inftl->nb_blocks = ip->lastUnit + 1;
294 
295 		/* Memory alloc */
296 		inftl->PUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
297 		if (!inftl->PUtable) {
298 			printk(KERN_WARNING "INFTL: allocation of PUtable "
299 				"failed (%zd bytes)\n",
300 				inftl->nb_blocks * sizeof(u16));
301 			return -ENOMEM;
302 		}
303 
304 		inftl->VUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
305 		if (!inftl->VUtable) {
306 			kfree(inftl->PUtable);
307 			printk(KERN_WARNING "INFTL: allocation of VUtable "
308 				"failed (%zd bytes)\n",
309 				inftl->nb_blocks * sizeof(u16));
310 			return -ENOMEM;
311 		}
312 
313 		/* Mark the blocks before INFTL MediaHeader as reserved */
314 		for (i = 0; i < inftl->nb_boot_blocks; i++)
315 			inftl->PUtable[i] = BLOCK_RESERVED;
316 		/* Mark all remaining blocks as potentially containing data */
317 		for (; i < inftl->nb_blocks; i++)
318 			inftl->PUtable[i] = BLOCK_NOTEXPLORED;
319 
320 		/* Mark this boot record (NFTL MediaHeader) block as reserved */
321 		inftl->PUtable[block] = BLOCK_RESERVED;
322 
323 		/* Read Bad Erase Unit Table and modify PUtable[] accordingly */
324 		for (i = 0; i < inftl->nb_blocks; i++) {
325 			int physblock;
326 			/* If any of the physical eraseblocks are bad, don't
327 			   use the unit. */
328 			for (physblock = 0; physblock < inftl->EraseSize; physblock += inftl->mbd.mtd->erasesize) {
329 				if (inftl->mbd.mtd->block_isbad(inftl->mbd.mtd, i * inftl->EraseSize + physblock))
330 					inftl->PUtable[i] = BLOCK_RESERVED;
331 			}
332 		}
333 
334 		inftl->MediaUnit = block;
335 		return 0;
336 	}
337 
338 	/* Not found. */
339 	return -1;
340 }
341 
342 static int memcmpb(void *a, int c, int n)
343 {
344 	int i;
345 	for (i = 0; i < n; i++) {
346 		if (c != ((unsigned char *)a)[i])
347 			return 1;
348 	}
349 	return 0;
350 }
351 
352 /*
353  * check_free_sector: check if a free sector is actually FREE,
354  *	i.e. All 0xff in data and oob area.
355  */
356 static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
357 	int len, int check_oob)
358 {
359 	u8 buf[SECTORSIZE + inftl->mbd.mtd->oobsize];
360 	struct mtd_info *mtd = inftl->mbd.mtd;
361 	size_t retlen;
362 	int i;
363 
364 	for (i = 0; i < len; i += SECTORSIZE) {
365 		if (mtd->read(mtd, address, SECTORSIZE, &retlen, buf))
366 			return -1;
367 		if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
368 			return -1;
369 
370 		if (check_oob) {
371 			if(inftl_read_oob(mtd, address, mtd->oobsize,
372 					  &retlen, &buf[SECTORSIZE]) < 0)
373 				return -1;
374 			if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
375 				return -1;
376 		}
377 		address += SECTORSIZE;
378 	}
379 
380 	return 0;
381 }
382 
383 /*
384  * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
385  *		 Unit and Update INFTL metadata. Each erase operation is
386  *		 checked with check_free_sectors.
387  *
388  * Return: 0 when succeed, -1 on error.
389  *
390  * ToDo: 1. Is it neceressary to check_free_sector after erasing ??
391  */
392 int INFTL_formatblock(struct INFTLrecord *inftl, int block)
393 {
394 	size_t retlen;
395 	struct inftl_unittail uci;
396 	struct erase_info *instr = &inftl->instr;
397 	struct mtd_info *mtd = inftl->mbd.mtd;
398 	int physblock;
399 
400 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_formatblock(inftl=%p,"
401 		"block=%d)\n", inftl, block);
402 
403 	memset(instr, 0, sizeof(struct erase_info));
404 
405 	/* FIXME: Shouldn't we be setting the 'discarded' flag to zero
406 	   _first_? */
407 
408 	/* Use async erase interface, test return code */
409 	instr->mtd = inftl->mbd.mtd;
410 	instr->addr = block * inftl->EraseSize;
411 	instr->len = inftl->mbd.mtd->erasesize;
412 	/* Erase one physical eraseblock at a time, even though the NAND api
413 	   allows us to group them.  This way we if we have a failure, we can
414 	   mark only the failed block in the bbt. */
415 	for (physblock = 0; physblock < inftl->EraseSize;
416 	     physblock += instr->len, instr->addr += instr->len) {
417 		mtd->erase(inftl->mbd.mtd, instr);
418 
419 		if (instr->state == MTD_ERASE_FAILED) {
420 			printk(KERN_WARNING "INFTL: error while formatting block %d\n",
421 				block);
422 			goto fail;
423 		}
424 
425 		/*
426 		 * Check the "freeness" of Erase Unit before updating metadata.
427 		 * FixMe: is this check really necessary? Since we have check
428 		 * the return code after the erase operation.
429 		 */
430 		if (check_free_sectors(inftl, instr->addr, instr->len, 1) != 0)
431 			goto fail;
432 	}
433 
434 	uci.EraseMark = cpu_to_le16(ERASE_MARK);
435 	uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
436 	uci.Reserved[0] = 0;
437 	uci.Reserved[1] = 0;
438 	uci.Reserved[2] = 0;
439 	uci.Reserved[3] = 0;
440 	instr->addr = block * inftl->EraseSize + SECTORSIZE * 2;
441 	if (inftl_write_oob(mtd, instr->addr + 8, 8, &retlen, (char *)&uci) < 0)
442 		goto fail;
443 	return 0;
444 fail:
445 	/* could not format, update the bad block table (caller is responsible
446 	   for setting the PUtable to BLOCK_RESERVED on failure) */
447 	inftl->mbd.mtd->block_markbad(inftl->mbd.mtd, instr->addr);
448 	return -1;
449 }
450 
451 /*
452  * format_chain: Format an invalid Virtual Unit chain. It frees all the Erase
453  *	Units in a Virtual Unit Chain, i.e. all the units are disconnected.
454  *
455  *	Since the chain is invalid then we will have to erase it from its
456  *	head (normally for INFTL we go from the oldest). But if it has a
457  *	loop then there is no oldest...
458  */
459 static void format_chain(struct INFTLrecord *inftl, unsigned int first_block)
460 {
461 	unsigned int block = first_block, block1;
462 
463 	printk(KERN_WARNING "INFTL: formatting chain at block %d\n",
464 		first_block);
465 
466 	for (;;) {
467 		block1 = inftl->PUtable[block];
468 
469 		printk(KERN_WARNING "INFTL: formatting block %d\n", block);
470 		if (INFTL_formatblock(inftl, block) < 0) {
471 			/*
472 			 * Cannot format !!!! Mark it as Bad Unit,
473 			 */
474 			inftl->PUtable[block] = BLOCK_RESERVED;
475 		} else {
476 			inftl->PUtable[block] = BLOCK_FREE;
477 		}
478 
479 		/* Goto next block on the chain */
480 		block = block1;
481 
482 		if (block == BLOCK_NIL || block >= inftl->lastEUN)
483 			break;
484 	}
485 }
486 
487 void INFTL_dumptables(struct INFTLrecord *s)
488 {
489 	int i;
490 
491 	printk("-------------------------------------------"
492 		"----------------------------------\n");
493 
494 	printk("VUtable[%d] ->", s->nb_blocks);
495 	for (i = 0; i < s->nb_blocks; i++) {
496 		if ((i % 8) == 0)
497 			printk("\n%04x: ", i);
498 		printk("%04x ", s->VUtable[i]);
499 	}
500 
501 	printk("\n-------------------------------------------"
502 		"----------------------------------\n");
503 
504 	printk("PUtable[%d-%d=%d] ->", s->firstEUN, s->lastEUN, s->nb_blocks);
505 	for (i = 0; i <= s->lastEUN; i++) {
506 		if ((i % 8) == 0)
507 			printk("\n%04x: ", i);
508 		printk("%04x ", s->PUtable[i]);
509 	}
510 
511 	printk("\n-------------------------------------------"
512 		"----------------------------------\n");
513 
514 	printk("INFTL ->\n"
515 		"  EraseSize       = %d\n"
516 		"  h/s/c           = %d/%d/%d\n"
517 		"  numvunits       = %d\n"
518 		"  firstEUN        = %d\n"
519 		"  lastEUN         = %d\n"
520 		"  numfreeEUNs     = %d\n"
521 		"  LastFreeEUN     = %d\n"
522 		"  nb_blocks       = %d\n"
523 		"  nb_boot_blocks  = %d",
524 		s->EraseSize, s->heads, s->sectors, s->cylinders,
525 		s->numvunits, s->firstEUN, s->lastEUN, s->numfreeEUNs,
526 		s->LastFreeEUN, s->nb_blocks, s->nb_boot_blocks);
527 
528 	printk("\n-------------------------------------------"
529 		"----------------------------------\n");
530 }
531 
532 void INFTL_dumpVUchains(struct INFTLrecord *s)
533 {
534 	int logical, block, i;
535 
536 	printk("-------------------------------------------"
537 		"----------------------------------\n");
538 
539 	printk("INFTL Virtual Unit Chains:\n");
540 	for (logical = 0; logical < s->nb_blocks; logical++) {
541 		block = s->VUtable[logical];
542 		if (block > s->nb_blocks)
543 			continue;
544 		printk("  LOGICAL %d --> %d ", logical, block);
545 		for (i = 0; i < s->nb_blocks; i++) {
546 			if (s->PUtable[block] == BLOCK_NIL)
547 				break;
548 			block = s->PUtable[block];
549 			printk("%d ", block);
550 		}
551 		printk("\n");
552 	}
553 
554 	printk("-------------------------------------------"
555 		"----------------------------------\n");
556 }
557 
558 int INFTL_mount(struct INFTLrecord *s)
559 {
560 	struct mtd_info *mtd = s->mbd.mtd;
561 	unsigned int block, first_block, prev_block, last_block;
562 	unsigned int first_logical_block, logical_block, erase_mark;
563 	int chain_length, do_format_chain;
564 	struct inftl_unithead1 h0;
565 	struct inftl_unittail h1;
566 	size_t retlen;
567 	int i;
568 	u8 *ANACtable, ANAC;
569 
570 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_mount(inftl=%p)\n", s);
571 
572 	/* Search for INFTL MediaHeader and Spare INFTL Media Header */
573 	if (find_boot_record(s) < 0) {
574 		printk(KERN_WARNING "INFTL: could not find valid boot record?\n");
575 		return -ENXIO;
576 	}
577 
578 	/* Init the logical to physical table */
579 	for (i = 0; i < s->nb_blocks; i++)
580 		s->VUtable[i] = BLOCK_NIL;
581 
582 	logical_block = block = BLOCK_NIL;
583 
584 	/* Temporary buffer to store ANAC numbers. */
585 	ANACtable = kmalloc(s->nb_blocks * sizeof(u8), GFP_KERNEL);
586 	if (!ANACtable) {
587 		printk(KERN_WARNING "INFTL: allocation of ANACtable "
588 				"failed (%zd bytes)\n",
589 				s->nb_blocks * sizeof(u8));
590 		return -ENOMEM;
591 	}
592 	memset(ANACtable, 0, s->nb_blocks);
593 
594 	/*
595 	 * First pass is to explore each physical unit, and construct the
596 	 * virtual chains that exist (newest physical unit goes into VUtable).
597 	 * Any block that is in any way invalid will be left in the
598 	 * NOTEXPLORED state. Then at the end we will try to format it and
599 	 * mark it as free.
600 	 */
601 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: pass 1, explore each unit\n");
602 	for (first_block = s->firstEUN; first_block <= s->lastEUN; first_block++) {
603 		if (s->PUtable[first_block] != BLOCK_NOTEXPLORED)
604 			continue;
605 
606 		do_format_chain = 0;
607 		first_logical_block = BLOCK_NIL;
608 		last_block = BLOCK_NIL;
609 		block = first_block;
610 
611 		for (chain_length = 0; ; chain_length++) {
612 
613 			if ((chain_length == 0) &&
614 			    (s->PUtable[block] != BLOCK_NOTEXPLORED)) {
615 				/* Nothing to do here, onto next block */
616 				break;
617 			}
618 
619 			if (inftl_read_oob(mtd, block * s->EraseSize + 8,
620 					   8, &retlen, (char *)&h0) < 0 ||
621 			    inftl_read_oob(mtd, block * s->EraseSize +
622 					   2 * SECTORSIZE + 8, 8, &retlen,
623 					   (char *)&h1) < 0) {
624 				/* Should never happen? */
625 				do_format_chain++;
626 				break;
627 			}
628 
629 			logical_block = le16_to_cpu(h0.virtualUnitNo);
630 			prev_block = le16_to_cpu(h0.prevUnitNo);
631 			erase_mark = le16_to_cpu((h1.EraseMark | h1.EraseMark1));
632 			ANACtable[block] = h0.ANAC;
633 
634 			/* Previous block is relative to start of Partition */
635 			if (prev_block < s->nb_blocks)
636 				prev_block += s->firstEUN;
637 
638 			/* Already explored partial chain? */
639 			if (s->PUtable[block] != BLOCK_NOTEXPLORED) {
640 				/* Check if chain for this logical */
641 				if (logical_block == first_logical_block) {
642 					if (last_block != BLOCK_NIL)
643 						s->PUtable[last_block] = block;
644 				}
645 				break;
646 			}
647 
648 			/* Check for invalid block */
649 			if (erase_mark != ERASE_MARK) {
650 				printk(KERN_WARNING "INFTL: corrupt block %d "
651 					"in chain %d, chain length %d, erase "
652 					"mark 0x%x?\n", block, first_block,
653 					chain_length, erase_mark);
654 				/*
655 				 * Assume end of chain, probably incomplete
656 				 * fold/erase...
657 				 */
658 				if (chain_length == 0)
659 					do_format_chain++;
660 				break;
661 			}
662 
663 			/* Check for it being free already then... */
664 			if ((logical_block == BLOCK_FREE) ||
665 			    (logical_block == BLOCK_NIL)) {
666 				s->PUtable[block] = BLOCK_FREE;
667 				break;
668 			}
669 
670 			/* Sanity checks on block numbers */
671 			if ((logical_block >= s->nb_blocks) ||
672 			    ((prev_block >= s->nb_blocks) &&
673 			     (prev_block != BLOCK_NIL))) {
674 				if (chain_length > 0) {
675 					printk(KERN_WARNING "INFTL: corrupt "
676 						"block %d in chain %d?\n",
677 						block, first_block);
678 					do_format_chain++;
679 				}
680 				break;
681 			}
682 
683 			if (first_logical_block == BLOCK_NIL) {
684 				first_logical_block = logical_block;
685 			} else {
686 				if (first_logical_block != logical_block) {
687 					/* Normal for folded chain... */
688 					break;
689 				}
690 			}
691 
692 			/*
693 			 * Current block is valid, so if we followed a virtual
694 			 * chain to get here then we can set the previous
695 			 * block pointer in our PUtable now. Then move onto
696 			 * the previous block in the chain.
697 			 */
698 			s->PUtable[block] = BLOCK_NIL;
699 			if (last_block != BLOCK_NIL)
700 				s->PUtable[last_block] = block;
701 			last_block = block;
702 			block = prev_block;
703 
704 			/* Check for end of chain */
705 			if (block == BLOCK_NIL)
706 				break;
707 
708 			/* Validate next block before following it... */
709 			if (block > s->lastEUN) {
710 				printk(KERN_WARNING "INFTL: invalid previous "
711 					"block %d in chain %d?\n", block,
712 					first_block);
713 				do_format_chain++;
714 				break;
715 			}
716 		}
717 
718 		if (do_format_chain) {
719 			format_chain(s, first_block);
720 			continue;
721 		}
722 
723 		/*
724 		 * Looks like a valid chain then. It may not really be the
725 		 * newest block in the chain, but it is the newest we have
726 		 * found so far. We might update it in later iterations of
727 		 * this loop if we find something newer.
728 		 */
729 		s->VUtable[first_logical_block] = first_block;
730 		logical_block = BLOCK_NIL;
731 	}
732 
733 #ifdef CONFIG_MTD_DEBUG_VERBOSE
734 	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
735 		INFTL_dumptables(s);
736 #endif
737 
738 	/*
739 	 * Second pass, check for infinite loops in chains. These are
740 	 * possible because we don't update the previous pointers when
741 	 * we fold chains. No big deal, just fix them up in PUtable.
742 	 */
743 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: pass 2, validate virtual chains\n");
744 	for (logical_block = 0; logical_block < s->numvunits; logical_block++) {
745 		block = s->VUtable[logical_block];
746 		last_block = BLOCK_NIL;
747 
748 		/* Check for free/reserved/nil */
749 		if (block >= BLOCK_RESERVED)
750 			continue;
751 
752 		ANAC = ANACtable[block];
753 		for (i = 0; i < s->numvunits; i++) {
754 			if (s->PUtable[block] == BLOCK_NIL)
755 				break;
756 			if (s->PUtable[block] > s->lastEUN) {
757 				printk(KERN_WARNING "INFTL: invalid prev %d, "
758 					"in virtual chain %d\n",
759 					s->PUtable[block], logical_block);
760 				s->PUtable[block] = BLOCK_NIL;
761 
762 			}
763 			if (ANACtable[block] != ANAC) {
764 				/*
765 				 * Chain must point back to itself. This is ok,
766 				 * but we will need adjust the tables with this
767 				 * newest block and oldest block.
768 				 */
769 				s->VUtable[logical_block] = block;
770 				s->PUtable[last_block] = BLOCK_NIL;
771 				break;
772 			}
773 
774 			ANAC--;
775 			last_block = block;
776 			block = s->PUtable[block];
777 		}
778 
779 		if (i >= s->nb_blocks) {
780 			/*
781 			 * Uhoo, infinite chain with valid ANACS!
782 			 * Format whole chain...
783 			 */
784 			format_chain(s, first_block);
785 		}
786 	}
787 
788 #ifdef CONFIG_MTD_DEBUG_VERBOSE
789 	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
790 		INFTL_dumptables(s);
791 	if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
792 		INFTL_dumpVUchains(s);
793 #endif
794 
795 	/*
796 	 * Third pass, format unreferenced blocks and init free block count.
797 	 */
798 	s->numfreeEUNs = 0;
799 	s->LastFreeEUN = BLOCK_NIL;
800 
801 	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: pass 3, format unused blocks\n");
802 	for (block = s->firstEUN; block <= s->lastEUN; block++) {
803 		if (s->PUtable[block] == BLOCK_NOTEXPLORED) {
804 			printk("INFTL: unreferenced block %d, formatting it\n",
805 				block);
806 			if (INFTL_formatblock(s, block) < 0)
807 				s->PUtable[block] = BLOCK_RESERVED;
808 			else
809 				s->PUtable[block] = BLOCK_FREE;
810 		}
811 		if (s->PUtable[block] == BLOCK_FREE) {
812 			s->numfreeEUNs++;
813 			if (s->LastFreeEUN == BLOCK_NIL)
814 				s->LastFreeEUN = block;
815 		}
816 	}
817 
818 	kfree(ANACtable);
819 	return 0;
820 }
821