1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * drivers/mtd/nand/raw/nand_util.c
4  *
5  * Copyright (C) 2006 by Weiss-Electronic GmbH.
6  * All rights reserved.
7  *
8  * @author:	Guido Classen <clagix@gmail.com>
9  * @descr:	NAND Flash support
10  * @references: borrowed heavily from Linux mtd-utils code:
11  *		flash_eraseall.c by Arcom Control System Ltd
12  *		nandwrite.c by Steven J. Hill (sjhill@realitydiluted.com)
13  *			       and Thomas Gleixner (tglx@linutronix.de)
14  *
15  * Copyright (C) 2008 Nokia Corporation: drop_ffs() function by
16  * Artem Bityutskiy <dedekind1@gmail.com> from mtd-utils
17  *
18  * Copyright 2010 Freescale Semiconductor
19  */
20 
21 #include <common.h>
22 #include <command.h>
23 #include <log.h>
24 #include <watchdog.h>
25 #include <malloc.h>
26 #include <memalign.h>
27 #include <div64.h>
28 #include <asm/cache.h>
29 #include <dm/devres.h>
30 
31 #include <linux/errno.h>
32 #include <linux/mtd/mtd.h>
33 #include <linux/mtd/rawnand.h>
34 #include <nand.h>
35 #include <jffs2/jffs2.h>
36 
37 typedef struct erase_info	erase_info_t;
38 typedef struct mtd_info		mtd_info_t;
39 
40 /* support only for native endian JFFS2 */
41 #define cpu_to_je16(x) (x)
42 #define cpu_to_je32(x) (x)
43 
44 /**
45  * nand_erase_opts: - erase NAND flash with support for various options
46  *		      (jffs2 formatting)
47  *
48  * @param mtd		nand mtd instance to erase
49  * @param opts		options,  @see struct nand_erase_options
50  * Return:		0 in case of success
51  *
52  * This code is ported from flash_eraseall.c from Linux mtd utils by
53  * Arcom Control System Ltd.
54  */
nand_erase_opts(struct mtd_info * mtd,const nand_erase_options_t * opts)55 int nand_erase_opts(struct mtd_info *mtd,
56 		    const nand_erase_options_t *opts)
57 {
58 	struct jffs2_unknown_node cleanmarker;
59 	erase_info_t erase;
60 	unsigned long erase_length, erased_length; /* in blocks */
61 	int result;
62 	int percent_complete = -1;
63 	const char *mtd_device = mtd->name;
64 	struct mtd_oob_ops oob_opts;
65 	struct nand_chip *chip = mtd_to_nand(mtd);
66 
67 	if ((opts->offset & (mtd->erasesize - 1)) != 0) {
68 		printf("Attempt to erase non block-aligned data\n");
69 		return -1;
70 	}
71 
72 	memset(&erase, 0, sizeof(erase));
73 	memset(&oob_opts, 0, sizeof(oob_opts));
74 
75 	erase.mtd = mtd;
76 	erase.len = mtd->erasesize;
77 	erase.addr = opts->offset;
78 	erase_length = lldiv(opts->length + mtd->erasesize - 1,
79 			     mtd->erasesize);
80 
81 	cleanmarker.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
82 	cleanmarker.nodetype = cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER);
83 	cleanmarker.totlen = cpu_to_je32(8);
84 
85 	/* scrub option allows to erase badblock. To prevent internal
86 	 * check from erase() method, set block check method to dummy
87 	 * and disable bad block table while erasing.
88 	 */
89 	if (opts->scrub) {
90 		erase.scrub = opts->scrub;
91 		/*
92 		 * We don't need the bad block table anymore...
93 		 * after scrub, there are no bad blocks left!
94 		 */
95 		if (chip->bbt) {
96 			kfree(chip->bbt);
97 		}
98 		chip->bbt = NULL;
99 		chip->options &= ~NAND_BBT_SCANNED;
100 	}
101 
102 	for (erased_length = 0;
103 	     erased_length < erase_length;
104 	     erase.addr += mtd->erasesize) {
105 
106 		schedule();
107 
108 		if (opts->lim && (erase.addr >= (opts->offset + opts->lim))) {
109 			puts("Size of erase exceeds limit\n");
110 			return -EFBIG;
111 		}
112 		if (!opts->scrub) {
113 			int ret = mtd_block_isbad(mtd, erase.addr);
114 			if (ret > 0) {
115 				if (!opts->quiet)
116 					printf("\rSkipping %s at  "
117 					       "0x%08llx                 "
118 					       "                         \n",
119 					       ret == 1 ? "bad block" : "bbt reserved",
120 					       erase.addr);
121 
122 				if (!opts->spread)
123 					erased_length++;
124 
125 				continue;
126 
127 			} else if (ret < 0) {
128 				printf("\n%s: MTD get bad block failed: %d\n",
129 				       mtd_device,
130 				       ret);
131 				return -1;
132 			}
133 		}
134 
135 		erased_length++;
136 
137 		result = mtd_erase(mtd, &erase);
138 		if (result != 0) {
139 			printf("\n%s: MTD Erase failure: %d\n",
140 			       mtd_device, result);
141 			continue;
142 		}
143 
144 		/* format for JFFS2 ? */
145 		if (opts->jffs2 && chip->ecc.layout->oobavail >= 8) {
146 			struct mtd_oob_ops ops;
147 			ops.ooblen = 8;
148 			ops.datbuf = NULL;
149 			ops.oobbuf = (uint8_t *)&cleanmarker;
150 			ops.ooboffs = 0;
151 			ops.mode = MTD_OPS_AUTO_OOB;
152 
153 			result = mtd_write_oob(mtd, erase.addr, &ops);
154 			if (result != 0) {
155 				printf("\n%s: MTD writeoob failure: %d\n",
156 				       mtd_device, result);
157 				continue;
158 			}
159 		}
160 
161 		if (!opts->quiet) {
162 			unsigned long long n = erased_length * 100ULL;
163 			int percent;
164 
165 			do_div(n, erase_length);
166 			percent = (int)n;
167 
168 			/* output progress message only at whole percent
169 			 * steps to reduce the number of messages printed
170 			 * on (slow) serial consoles
171 			 */
172 			if (percent != percent_complete) {
173 				percent_complete = percent;
174 
175 				printf("\rErasing at 0x%llx -- %3d%% complete.",
176 				       erase.addr, percent);
177 
178 				if (opts->jffs2 && result == 0)
179 					printf(" Cleanmarker written at 0x%llx.",
180 					       erase.addr);
181 			}
182 		}
183 	}
184 	if (!opts->quiet)
185 		printf("\n");
186 
187 	return 0;
188 }
189 
190 #ifdef CONFIG_CMD_NAND_LOCK_UNLOCK
191 
192 #define NAND_CMD_LOCK_TIGHT     0x2c
193 #define NAND_CMD_LOCK_STATUS    0x7a
194 
195 /******************************************************************************
196  * Support for locking / unlocking operations of some NAND devices
197  *****************************************************************************/
198 
199 /**
200  * nand_lock: Set all pages of NAND flash chip to the LOCK or LOCK-TIGHT
201  *	      state
202  *
203  * @param mtd		nand mtd instance
204  * @param tight		bring device in lock tight mode
205  *
206  * Return:		0 on success, -1 in case of error
207  *
208  * The lock / lock-tight command only applies to the whole chip. To get some
209  * parts of the chip lock and others unlocked use the following sequence:
210  *
211  * - Lock all pages of the chip using nand_lock(mtd, 0) (or the lockpre pin)
212  * - Call nand_unlock() once for each consecutive area to be unlocked
213  * - If desired: Bring the chip to the lock-tight state using nand_lock(mtd, 1)
214  *
215  *   If the device is in lock-tight state software can't change the
216  *   current active lock/unlock state of all pages. nand_lock() / nand_unlock()
217  *   calls will fail. It is only posible to leave lock-tight state by
218  *   an hardware signal (low pulse on _WP pin) or by power down.
219  */
nand_lock(struct mtd_info * mtd,int tight)220 int nand_lock(struct mtd_info *mtd, int tight)
221 {
222 	int ret = 0;
223 	int status;
224 	struct nand_chip *chip = mtd_to_nand(mtd);
225 
226 	/* select the NAND device */
227 	chip->select_chip(mtd, 0);
228 
229 	/* check the Lock Tight Status */
230 	chip->cmdfunc(mtd, NAND_CMD_LOCK_STATUS, -1, 0);
231 	if (chip->read_byte(mtd) & NAND_LOCK_STATUS_TIGHT) {
232 		printf("nand_lock: Device is locked tight!\n");
233 		ret = -1;
234 		goto out;
235 	}
236 
237 	chip->cmdfunc(mtd,
238 		      (tight ? NAND_CMD_LOCK_TIGHT : NAND_CMD_LOCK),
239 		      -1, -1);
240 
241 	/* call wait ready function */
242 	status = chip->waitfunc(mtd, chip);
243 
244 	/* see if device thinks it succeeded */
245 	if (status & 0x01) {
246 		ret = -1;
247 	}
248 
249  out:
250 	/* de-select the NAND device */
251 	chip->select_chip(mtd, -1);
252 	return ret;
253 }
254 
255 /**
256  * nand_get_lock_status: - query current lock state from one page of NAND
257  *			   flash
258  *
259  * @param mtd		nand mtd instance
260  * @param offset	page address to query (must be page-aligned!)
261  *
262  * Return:		-1 in case of error
263  *			>0 lock status:
264  *			  bitfield with the following combinations:
265  *			  NAND_LOCK_STATUS_TIGHT: page in tight state
266  *			  NAND_LOCK_STATUS_UNLOCK: page unlocked
267  *
268  */
nand_get_lock_status(struct mtd_info * mtd,loff_t offset)269 int nand_get_lock_status(struct mtd_info *mtd, loff_t offset)
270 {
271 	int ret = 0;
272 	int chipnr;
273 	int page;
274 	struct nand_chip *chip = mtd_to_nand(mtd);
275 
276 	/* select the NAND device */
277 	chipnr = (int)(offset >> chip->chip_shift);
278 	chip->select_chip(mtd, chipnr);
279 
280 
281 	if ((offset & (mtd->writesize - 1)) != 0) {
282 		printf("nand_get_lock_status: "
283 			"Start address must be beginning of "
284 			"nand page!\n");
285 		ret = -1;
286 		goto out;
287 	}
288 
289 	/* check the Lock Status */
290 	page = (int)(offset >> chip->page_shift);
291 	chip->cmdfunc(mtd, NAND_CMD_LOCK_STATUS, -1, page & chip->pagemask);
292 
293 	ret = chip->read_byte(mtd) & (NAND_LOCK_STATUS_TIGHT
294 					  | NAND_LOCK_STATUS_UNLOCK);
295 
296  out:
297 	/* de-select the NAND device */
298 	chip->select_chip(mtd, -1);
299 	return ret;
300 }
301 
302 /**
303  * nand_unlock: - Unlock area of NAND pages
304  *		  only one consecutive area can be unlocked at one time!
305  *
306  * @param mtd		nand mtd instance
307  * @param start		start byte address
308  * @param length	number of bytes to unlock (must be a multiple of
309  *			page size mtd->writesize)
310  * @param allexcept	if set, unlock everything not selected
311  *
312  * Return:		0 on success, -1 in case of error
313  */
nand_unlock(struct mtd_info * mtd,loff_t start,size_t length,int allexcept)314 int nand_unlock(struct mtd_info *mtd, loff_t start, size_t length,
315 	int allexcept)
316 {
317 	int ret = 0;
318 	int chipnr;
319 	int status;
320 	int page;
321 	struct nand_chip *chip = mtd_to_nand(mtd);
322 
323 	debug("nand_unlock%s: start: %08llx, length: %zd!\n",
324 		allexcept ? " (allexcept)" : "", start, length);
325 
326 	/* select the NAND device */
327 	chipnr = (int)(start >> chip->chip_shift);
328 	chip->select_chip(mtd, chipnr);
329 
330 	/* check the WP bit */
331 	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
332 	if (!(chip->read_byte(mtd) & NAND_STATUS_WP)) {
333 		printf("nand_unlock: Device is write protected!\n");
334 		ret = -1;
335 		goto out;
336 	}
337 
338 	/* check the Lock Tight Status */
339 	page = (int)(start >> chip->page_shift);
340 	chip->cmdfunc(mtd, NAND_CMD_LOCK_STATUS, -1, page & chip->pagemask);
341 	if (chip->read_byte(mtd) & NAND_LOCK_STATUS_TIGHT) {
342 		printf("nand_unlock: Device is locked tight!\n");
343 		ret = -1;
344 		goto out;
345 	}
346 
347 	if ((start & (mtd->erasesize - 1)) != 0) {
348 		printf("nand_unlock: Start address must be beginning of "
349 			"nand block!\n");
350 		ret = -1;
351 		goto out;
352 	}
353 
354 	if (length == 0 || (length & (mtd->erasesize - 1)) != 0) {
355 		printf("nand_unlock: Length must be a multiple of nand block "
356 			"size %08x!\n", mtd->erasesize);
357 		ret = -1;
358 		goto out;
359 	}
360 
361 	/*
362 	 * Set length so that the last address is set to the
363 	 * starting address of the last block
364 	 */
365 	length -= mtd->erasesize;
366 
367 	/* submit address of first page to unlock */
368 	chip->cmdfunc(mtd, NAND_CMD_UNLOCK1, -1, page & chip->pagemask);
369 
370 	/* submit ADDRESS of LAST page to unlock */
371 	page += (int)(length >> chip->page_shift);
372 
373 	/*
374 	 * Page addresses for unlocking are supposed to be block-aligned.
375 	 * At least some NAND chips use the low bit to indicate that the
376 	 * page range should be inverted.
377 	 */
378 	if (allexcept)
379 		page |= 1;
380 
381 	chip->cmdfunc(mtd, NAND_CMD_UNLOCK2, -1, page & chip->pagemask);
382 
383 	/* call wait ready function */
384 	status = chip->waitfunc(mtd, chip);
385 	/* see if device thinks it succeeded */
386 	if (status & 0x01) {
387 		/* there was an error */
388 		ret = -1;
389 		goto out;
390 	}
391 
392  out:
393 	/* de-select the NAND device */
394 	chip->select_chip(mtd, -1);
395 	return ret;
396 }
397 #endif
398 
399 /**
400  * check_skip_len
401  *
402  * Check if there are any bad blocks, and whether length including bad
403  * blocks fits into device
404  *
405  * @param mtd nand mtd instance
406  * @param offset offset in flash
407  * @param length image length
408  * @param used length of flash needed for the requested length
409  * Return: 0 if the image fits and there are no bad blocks
410  *         1 if the image fits, but there are bad blocks
411  *        -1 if the image does not fit
412  */
check_skip_len(struct mtd_info * mtd,loff_t offset,size_t length,size_t * used)413 static int check_skip_len(struct mtd_info *mtd, loff_t offset, size_t length,
414 			  size_t *used)
415 {
416 	size_t len_excl_bad = 0;
417 	int ret = 0;
418 
419 	while (len_excl_bad < length) {
420 		size_t block_len, block_off;
421 		loff_t block_start;
422 
423 		if (offset >= mtd->size)
424 			return -1;
425 
426 		block_start = offset & ~(loff_t)(mtd->erasesize - 1);
427 		block_off = offset & (mtd->erasesize - 1);
428 		block_len = mtd->erasesize - block_off;
429 
430 		if (!nand_block_isbad(mtd, block_start))
431 			len_excl_bad += block_len;
432 		else
433 			ret = 1;
434 
435 		offset += block_len;
436 		*used += block_len;
437 	}
438 
439 	/* If the length is not a multiple of block_len, adjust. */
440 	if (len_excl_bad > length)
441 		*used -= (len_excl_bad - length);
442 
443 	return ret;
444 }
445 
446 #ifdef CONFIG_CMD_NAND_TRIMFFS
drop_ffs(const struct mtd_info * mtd,const u_char * buf,const size_t * len)447 static size_t drop_ffs(const struct mtd_info *mtd, const u_char *buf,
448 			const size_t *len)
449 {
450 	size_t l = *len;
451 	ssize_t i;
452 
453 	for (i = l - 1; i >= 0; i--)
454 		if (buf[i] != 0xFF)
455 			break;
456 
457 	/* The resulting length must be aligned to the minimum flash I/O size */
458 	l = i + 1;
459 	l = (l + mtd->writesize - 1) / mtd->writesize;
460 	l *=  mtd->writesize;
461 
462 	/*
463 	 * since the input length may be unaligned, prevent access past the end
464 	 * of the buffer
465 	 */
466 	return min(l, *len);
467 }
468 #endif
469 
470 /**
471  * nand_verify_page_oob:
472  *
473  * Verify a page of NAND flash, including the OOB.
474  * Reads page of NAND and verifies the contents and OOB against the
475  * values in ops.
476  *
477  * @param mtd		nand mtd instance
478  * @param ops		MTD operations, including data to verify
479  * @param ofs		offset in flash
480  * Return:		0 in case of success
481  */
nand_verify_page_oob(struct mtd_info * mtd,struct mtd_oob_ops * ops,loff_t ofs)482 int nand_verify_page_oob(struct mtd_info *mtd, struct mtd_oob_ops *ops,
483 			 loff_t ofs)
484 {
485 	int rval;
486 	struct mtd_oob_ops vops;
487 	size_t verlen = mtd->writesize + mtd->oobsize;
488 
489 	memcpy(&vops, ops, sizeof(vops));
490 
491 	vops.datbuf = memalign(ARCH_DMA_MINALIGN, verlen);
492 
493 	if (!vops.datbuf)
494 		return -ENOMEM;
495 
496 	vops.oobbuf = vops.datbuf + mtd->writesize;
497 
498 	rval = mtd_read_oob(mtd, ofs, &vops);
499 	if (!rval)
500 		rval = memcmp(ops->datbuf, vops.datbuf, vops.len);
501 	if (!rval)
502 		rval = memcmp(ops->oobbuf, vops.oobbuf, vops.ooblen);
503 
504 	free(vops.datbuf);
505 
506 	return rval ? -EIO : 0;
507 }
508 
509 /**
510  * nand_verify:
511  *
512  * Verify a region of NAND flash.
513  * Reads NAND in page-sized chunks and verifies the contents against
514  * the contents of a buffer.  The offset into the NAND must be
515  * page-aligned, and the function doesn't handle skipping bad blocks.
516  *
517  * @param mtd		nand mtd instance
518  * @param ofs		offset in flash
519  * @param len		buffer length
520  * @param buf		buffer to read from
521  * Return:		0 in case of success
522  */
nand_verify(struct mtd_info * mtd,loff_t ofs,size_t len,u_char * buf)523 int nand_verify(struct mtd_info *mtd, loff_t ofs, size_t len, u_char *buf)
524 {
525 	int rval = 0;
526 	size_t verofs;
527 	size_t verlen = mtd->writesize;
528 	uint8_t *verbuf = memalign(ARCH_DMA_MINALIGN, verlen);
529 
530 	if (!verbuf)
531 		return -ENOMEM;
532 
533 	/* Read the NAND back in page-size groups to limit malloc size */
534 	for (verofs = ofs; verofs < ofs + len;
535 	     verofs += verlen, buf += verlen) {
536 		verlen = min(mtd->writesize, (uint32_t)(ofs + len - verofs));
537 		rval = nand_read(mtd, verofs, &verlen, verbuf);
538 		if (!rval || (rval == -EUCLEAN))
539 			rval = memcmp(buf, verbuf, verlen);
540 
541 		if (rval)
542 			break;
543 	}
544 
545 	free(verbuf);
546 
547 	return rval ? -EIO : 0;
548 }
549 
550 /**
551  * nand_write_skip_bad:
552  *
553  * Write image to NAND flash.
554  * Blocks that are marked bad are skipped and the is written to the next
555  * block instead as long as the image is short enough to fit even after
556  * skipping the bad blocks.  Due to bad blocks we may not be able to
557  * perform the requested write.  In the case where the write would
558  * extend beyond the end of the NAND device, both length and actual (if
559  * not NULL) are set to 0.  In the case where the write would extend
560  * beyond the limit we are passed, length is set to 0 and actual is set
561  * to the required length.
562  *
563  * @param mtd		nand mtd instance
564  * @param offset	offset in flash
565  * @param length	buffer length
566  * @param actual	set to size required to write length worth of
567  *			buffer or 0 on error, if not NULL
568  * @param lim		maximum size that actual may be in order to not
569  *			exceed the buffer
570  * @param buffer        buffer to read from
571  * @param flags		flags modifying the behaviour of the write to NAND
572  * Return:		0 in case of success
573  */
nand_write_skip_bad(struct mtd_info * mtd,loff_t offset,size_t * length,size_t * actual,loff_t lim,u_char * buffer,int flags)574 int nand_write_skip_bad(struct mtd_info *mtd, loff_t offset, size_t *length,
575 			size_t *actual, loff_t lim, u_char *buffer, int flags)
576 {
577 	int rval = 0, blocksize;
578 	size_t left_to_write = *length;
579 	size_t used_for_write = 0;
580 	u_char *p_buffer = buffer;
581 	int need_skip;
582 
583 	if (actual)
584 		*actual = 0;
585 
586 	blocksize = mtd->erasesize;
587 
588 	/*
589 	 * nand_write() handles unaligned, partial page writes.
590 	 *
591 	 * We allow length to be unaligned, for convenience in
592 	 * using the $filesize variable.
593 	 *
594 	 * However, starting at an unaligned offset makes the
595 	 * semantics of bad block skipping ambiguous (really,
596 	 * you should only start a block skipping access at a
597 	 * partition boundary).  So don't try to handle that.
598 	 */
599 	if ((offset & (mtd->writesize - 1)) != 0) {
600 		printf("Attempt to write non page-aligned data\n");
601 		*length = 0;
602 		return -EINVAL;
603 	}
604 
605 	need_skip = check_skip_len(mtd, offset, *length, &used_for_write);
606 
607 	if (actual)
608 		*actual = used_for_write;
609 
610 	if (need_skip < 0) {
611 		printf("Attempt to write outside the flash area\n");
612 		*length = 0;
613 		return -EINVAL;
614 	}
615 
616 	if (used_for_write > lim) {
617 		puts("Size of write exceeds partition or device limit\n");
618 		*length = 0;
619 		return -EFBIG;
620 	}
621 
622 	if (!need_skip && !(flags & WITH_DROP_FFS)) {
623 		rval = nand_write(mtd, offset, length, buffer);
624 
625 		if ((flags & WITH_WR_VERIFY) && !rval)
626 			rval = nand_verify(mtd, offset, *length, buffer);
627 
628 		if (rval == 0)
629 			return 0;
630 
631 		*length = 0;
632 		printf("NAND write to offset %llx failed %d\n",
633 			offset, rval);
634 		return rval;
635 	}
636 
637 	while (left_to_write > 0) {
638 		loff_t block_start = offset & ~(loff_t)(mtd->erasesize - 1);
639 		size_t block_offset = offset & (mtd->erasesize - 1);
640 		size_t write_size, truncated_write_size;
641 
642 		schedule();
643 
644 		if (nand_block_isbad(mtd, block_start)) {
645 			printf("Skip bad block 0x%08llx\n", block_start);
646 			offset += mtd->erasesize - block_offset;
647 			continue;
648 		}
649 
650 		if (left_to_write < (blocksize - block_offset))
651 			write_size = left_to_write;
652 		else
653 			write_size = blocksize - block_offset;
654 
655 		truncated_write_size = write_size;
656 #ifdef CONFIG_CMD_NAND_TRIMFFS
657 		if (flags & WITH_DROP_FFS)
658 			truncated_write_size = drop_ffs(mtd, p_buffer,
659 					&write_size);
660 #endif
661 
662 		rval = nand_write(mtd, offset, &truncated_write_size,
663 				p_buffer);
664 
665 		if ((flags & WITH_WR_VERIFY) && !rval)
666 			rval = nand_verify(mtd, offset,
667 				truncated_write_size, p_buffer);
668 
669 		offset += write_size;
670 		p_buffer += write_size;
671 
672 		if (rval != 0) {
673 			printf("NAND write to offset %llx failed %d\n",
674 				offset, rval);
675 			*length -= left_to_write;
676 			return rval;
677 		}
678 
679 		left_to_write -= write_size;
680 	}
681 
682 	return 0;
683 }
684 
685 /**
686  * nand_read_skip_bad:
687  *
688  * Read image from NAND flash.
689  * Blocks that are marked bad are skipped and the next block is read
690  * instead as long as the image is short enough to fit even after
691  * skipping the bad blocks.  Due to bad blocks we may not be able to
692  * perform the requested read.  In the case where the read would extend
693  * beyond the end of the NAND device, both length and actual (if not
694  * NULL) are set to 0.  In the case where the read would extend beyond
695  * the limit we are passed, length is set to 0 and actual is set to the
696  * required length.
697  *
698  * @param mtd nand mtd instance
699  * @param offset offset in flash
700  * @param length buffer length, on return holds number of read bytes
701  * @param actual set to size required to read length worth of buffer or 0
702  * on error, if not NULL
703  * @param lim maximum size that actual may be in order to not exceed the
704  * buffer
705  * @param buffer buffer to write to
706  * Return: 0 in case of success
707  */
nand_read_skip_bad(struct mtd_info * mtd,loff_t offset,size_t * length,size_t * actual,loff_t lim,u_char * buffer)708 int nand_read_skip_bad(struct mtd_info *mtd, loff_t offset, size_t *length,
709 		       size_t *actual, loff_t lim, u_char *buffer)
710 {
711 	int rval;
712 	size_t left_to_read = *length;
713 	size_t used_for_read = 0;
714 	u_char *p_buffer = buffer;
715 	int need_skip;
716 
717 	if ((offset & (mtd->writesize - 1)) != 0) {
718 		printf("Attempt to read non page-aligned data\n");
719 		*length = 0;
720 		if (actual)
721 			*actual = 0;
722 		return -EINVAL;
723 	}
724 
725 	need_skip = check_skip_len(mtd, offset, *length, &used_for_read);
726 
727 	if (actual)
728 		*actual = used_for_read;
729 
730 	if (need_skip < 0) {
731 		printf("Attempt to read outside the flash area\n");
732 		*length = 0;
733 		return -EINVAL;
734 	}
735 
736 	if (used_for_read > lim) {
737 		puts("Size of read exceeds partition or device limit\n");
738 		*length = 0;
739 		return -EFBIG;
740 	}
741 
742 	if (!need_skip) {
743 		rval = nand_read(mtd, offset, length, buffer);
744 		if (!rval || rval == -EUCLEAN)
745 			return 0;
746 
747 		*length = 0;
748 		printf("NAND read from offset %llx failed %d\n",
749 			offset, rval);
750 		return rval;
751 	}
752 
753 	while (left_to_read > 0) {
754 		size_t block_offset = offset & (mtd->erasesize - 1);
755 		size_t read_length;
756 
757 		schedule();
758 
759 		if (nand_block_isbad(mtd, offset & ~(mtd->erasesize - 1))) {
760 			printf("Skipping bad block 0x%08llx\n",
761 				offset & ~(mtd->erasesize - 1));
762 			offset += mtd->erasesize - block_offset;
763 			continue;
764 		}
765 
766 		if (left_to_read < (mtd->erasesize - block_offset))
767 			read_length = left_to_read;
768 		else
769 			read_length = mtd->erasesize - block_offset;
770 
771 		rval = nand_read(mtd, offset, &read_length, p_buffer);
772 		if (rval && rval != -EUCLEAN) {
773 			printf("NAND read from offset %llx failed %d\n",
774 				offset, rval);
775 			*length -= left_to_read;
776 			return rval;
777 		}
778 
779 		left_to_read -= read_length;
780 		offset       += read_length;
781 		p_buffer     += read_length;
782 	}
783 
784 	return 0;
785 }
786 
787 #ifdef CONFIG_CMD_NAND_TORTURE
788 
789 /**
790  * check_pattern:
791  *
792  * Check if buffer contains only a certain byte pattern.
793  *
794  * @param buf buffer to check
795  * @param patt the pattern to check
796  * @param size buffer size in bytes
797  * Return: 1 if there are only patt bytes in buf
798  *         0 if something else was found
799  */
check_pattern(const u_char * buf,u_char patt,int size)800 static int check_pattern(const u_char *buf, u_char patt, int size)
801 {
802 	int i;
803 
804 	for (i = 0; i < size; i++)
805 		if (buf[i] != patt)
806 			return 0;
807 	return 1;
808 }
809 
810 /**
811  * nand_torture:
812  *
813  * Torture a block of NAND flash.
814  * This is useful to determine if a block that caused a write error is still
815  * good or should be marked as bad.
816  *
817  * @param mtd nand mtd instance
818  * @param offset offset in flash
819  * Return: 0 if the block is still good
820  */
nand_torture(struct mtd_info * mtd,loff_t offset)821 int nand_torture(struct mtd_info *mtd, loff_t offset)
822 {
823 	u_char patterns[] = {0xa5, 0x5a, 0x00};
824 	struct erase_info instr = {
825 		.mtd = mtd,
826 		.addr = offset,
827 		.len = mtd->erasesize,
828 	};
829 	size_t retlen;
830 	int err, ret = -1, i, patt_count;
831 	u_char *buf;
832 
833 	if ((offset & (mtd->erasesize - 1)) != 0) {
834 		puts("Attempt to torture a block at a non block-aligned offset\n");
835 		return -EINVAL;
836 	}
837 
838 	if (offset + mtd->erasesize > mtd->size) {
839 		puts("Attempt to torture a block outside the flash area\n");
840 		return -EINVAL;
841 	}
842 
843 	patt_count = ARRAY_SIZE(patterns);
844 
845 	buf = malloc_cache_aligned(mtd->erasesize);
846 	if (buf == NULL) {
847 		puts("Out of memory for erase block buffer\n");
848 		return -ENOMEM;
849 	}
850 
851 	for (i = 0; i < patt_count; i++) {
852 		err = mtd_erase(mtd, &instr);
853 		if (err) {
854 			printf("%s: erase() failed for block at 0x%llx: %d\n",
855 				mtd->name, instr.addr, err);
856 			goto out;
857 		}
858 
859 		/* Make sure the block contains only 0xff bytes */
860 		err = mtd_read(mtd, offset, mtd->erasesize, &retlen, buf);
861 		if ((err && err != -EUCLEAN) || retlen != mtd->erasesize) {
862 			printf("%s: read() failed for block at 0x%llx: %d\n",
863 				mtd->name, instr.addr, err);
864 			goto out;
865 		}
866 
867 		err = check_pattern(buf, 0xff, mtd->erasesize);
868 		if (!err) {
869 			printf("Erased block at 0x%llx, but a non-0xff byte was found\n",
870 				offset);
871 			ret = -EIO;
872 			goto out;
873 		}
874 
875 		/* Write a pattern and check it */
876 		memset(buf, patterns[i], mtd->erasesize);
877 		err = mtd_write(mtd, offset, mtd->erasesize, &retlen, buf);
878 		if (err || retlen != mtd->erasesize) {
879 			printf("%s: write() failed for block at 0x%llx: %d\n",
880 				mtd->name, instr.addr, err);
881 			goto out;
882 		}
883 
884 		err = mtd_read(mtd, offset, mtd->erasesize, &retlen, buf);
885 		if ((err && err != -EUCLEAN) || retlen != mtd->erasesize) {
886 			printf("%s: read() failed for block at 0x%llx: %d\n",
887 				mtd->name, instr.addr, err);
888 			goto out;
889 		}
890 
891 		err = check_pattern(buf, patterns[i], mtd->erasesize);
892 		if (!err) {
893 			printf("Pattern 0x%.2x checking failed for block at "
894 					"0x%llx\n", patterns[i], offset);
895 			ret = -EIO;
896 			goto out;
897 		}
898 	}
899 
900 	ret = 0;
901 
902 out:
903 	free(buf);
904 	return ret;
905 }
906 
907 #endif
908