2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2006, 2007
4 * SPDX-License-Identifier: GPL-2.0+
6 * Author: Artem Bityutskiy (Битюцкий Артём)
10 * UBI input/output sub-system.
12 * This sub-system provides a uniform way to work with all kinds of the
13 * underlying MTD devices. It also implements handy functions for reading and
14 * writing UBI headers.
16 * We are trying to have a paranoid mindset and not to trust to what we read
17 * from the flash media in order to be more secure and robust. So this
18 * sub-system validates every single header it reads from the flash media.
20 * Some words about how the eraseblock headers are stored.
22 * The erase counter header is always stored at offset zero. By default, the
23 * VID header is stored after the EC header at the closest aligned offset
24 * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID
25 * header at the closest aligned offset. But this default layout may be
26 * changed. For example, for different reasons (e.g., optimization) UBI may be
27 * asked to put the VID header at further offset, and even at an unaligned
28 * offset. Of course, if the offset of the VID header is unaligned, UBI adds
29 * proper padding in front of it. Data offset may also be changed but it has to
32 * About minimal I/O units. In general, UBI assumes flash device model where
33 * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1,
34 * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the
35 * @ubi->mtd->writesize field. But as an exception, UBI admits of using another
36 * (smaller) minimal I/O unit size for EC and VID headers to make it possible
37 * to do different optimizations.
39 * This is extremely useful in case of NAND flashes which admit of several
40 * write operations to one NAND page. In this case UBI can fit EC and VID
41 * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal
42 * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still
43 * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI
46 * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so
47 * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID
50 * Q: why not just to treat sub-page as a minimal I/O unit of this flash
51 * device, e.g., make @ubi->min_io_size = 512 in the example above?
53 * A: because when writing a sub-page, MTD still writes a full 2K page but the
54 * bytes which are not relevant to the sub-page are 0xFF. So, basically,
55 * writing 4x512 sub-pages is 4 times slower than writing one 2KiB NAND page.
56 * Thus, we prefer to use sub-pages only for EC and VID headers.
58 * As it was noted above, the VID header may start at a non-aligned offset.
59 * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page,
60 * the VID header may reside at offset 1984 which is the last 64 bytes of the
61 * last sub-page (EC header is always at offset zero). This causes some
62 * difficulties when reading and writing VID headers.
64 * Suppose we have a 64-byte buffer and we read a VID header at it. We change
65 * the data and want to write this VID header out. As we can only write in
66 * 512-byte chunks, we have to allocate one more buffer and copy our VID header
67 * to offset 448 of this buffer.
69 * The I/O sub-system does the following trick in order to avoid this extra
70 * copy. It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID
71 * header and returns a pointer to offset @ubi->vid_hdr_shift of this buffer.
72 * When the VID header is being written out, it shifts the VID header pointer
73 * back and writes the whole sub-page.
78 #include <linux/crc32.h>
79 #include <linux/err.h>
80 #include <linux/slab.h>
82 #include <ubi_uboot.h>
87 static int self_check_not_bad(const struct ubi_device *ubi, int pnum);
88 static int self_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum);
89 static int self_check_ec_hdr(const struct ubi_device *ubi, int pnum,
90 const struct ubi_ec_hdr *ec_hdr);
91 static int self_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);
92 static int self_check_vid_hdr(const struct ubi_device *ubi, int pnum,
93 const struct ubi_vid_hdr *vid_hdr);
94 static int self_check_write(struct ubi_device *ubi, const void *buf, int pnum,
98 * ubi_io_read - read data from a physical eraseblock.
99 * @ubi: UBI device description object
100 * @buf: buffer where to store the read data
101 * @pnum: physical eraseblock number to read from
102 * @offset: offset within the physical eraseblock from where to read
103 * @len: how many bytes to read
105 * This function reads data from offset @offset of physical eraseblock @pnum
106 * and stores the read data in the @buf buffer. The following return codes are
109 * o %0 if all the requested data were successfully read;
110 * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
111 * correctable bit-flips were detected; this is harmless but may indicate
112 * that this eraseblock may become bad soon (but do not have to);
113 * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
114 * example it can be an ECC error in case of NAND; this most probably means
115 * that the data is corrupted;
116 * o %-EIO if some I/O error occurred;
117 * o other negative error codes in case of other errors.
119 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
122 int err, retries = 0;
126 dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
128 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
129 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
132 err = self_check_not_bad(ubi, pnum);
137 * Deliberately corrupt the buffer to improve robustness. Indeed, if we
138 * do not do this, the following may happen:
139 * 1. The buffer contains data from previous operation, e.g., read from
140 * another PEB previously. The data looks like expected, e.g., if we
141 * just do not read anything and return - the caller would not
142 * notice this. E.g., if we are reading a VID header, the buffer may
143 * contain a valid VID header from another PEB.
144 * 2. The driver is buggy and returns us success or -EBADMSG or
145 * -EUCLEAN, but it does not actually put any data to the buffer.
147 * This may confuse UBI or upper layers - they may think the buffer
148 * contains valid data while in fact it is just old data. This is
149 * especially possible because UBI (and UBIFS) relies on CRC, and
150 * treats data as correct even in case of ECC errors if the CRC is
153 * Try to prevent this situation by changing the first byte of the
156 *((uint8_t *)buf) ^= 0xFF;
158 addr = (loff_t)pnum * ubi->peb_size + offset;
160 err = mtd_read(ubi->mtd, addr, len, &read, buf);
162 const char *errstr = mtd_is_eccerr(err) ? " (ECC error)" : "";
164 if (mtd_is_bitflip(err)) {
166 * -EUCLEAN is reported if there was a bit-flip which
167 * was corrected, so this is harmless.
169 * We do not report about it here unless debugging is
170 * enabled. A corresponding message will be printed
171 * later, when it is has been scrubbed.
173 ubi_msg("fixable bit-flip detected at PEB %d", pnum);
174 ubi_assert(len == read);
175 return UBI_IO_BITFLIPS;
178 if (retries++ < UBI_IO_RETRIES) {
179 ubi_warn("error %d%s while reading %d bytes from PEB %d:%d, read only %zd bytes, retry",
180 err, errstr, len, pnum, offset, read);
185 ubi_err("error %d%s while reading %d bytes from PEB %d:%d, read %zd bytes",
186 err, errstr, len, pnum, offset, read);
190 * The driver should never return -EBADMSG if it failed to read
191 * all the requested data. But some buggy drivers might do
192 * this, so we change it to -EIO.
194 if (read != len && mtd_is_eccerr(err)) {
199 ubi_assert(len == read);
201 if (ubi_dbg_is_bitflip(ubi)) {
202 dbg_gen("bit-flip (emulated)");
203 err = UBI_IO_BITFLIPS;
211 * ubi_io_write - write data to a physical eraseblock.
212 * @ubi: UBI device description object
213 * @buf: buffer with the data to write
214 * @pnum: physical eraseblock number to write to
215 * @offset: offset within the physical eraseblock where to write
216 * @len: how many bytes to write
218 * This function writes @len bytes of data from buffer @buf to offset @offset
219 * of physical eraseblock @pnum. If all the data were successfully written,
220 * zero is returned. If an error occurred, this function returns a negative
221 * error code. If %-EIO is returned, the physical eraseblock most probably went
224 * Note, in case of an error, it is possible that something was still written
225 * to the flash media, but may be some garbage.
227 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
234 dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
236 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
237 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
238 ubi_assert(offset % ubi->hdrs_min_io_size == 0);
239 ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
242 ubi_err("read-only mode");
246 err = self_check_not_bad(ubi, pnum);
250 /* The area we are writing to has to contain all 0xFF bytes */
251 err = ubi_self_check_all_ff(ubi, pnum, offset, len);
255 if (offset >= ubi->leb_start) {
257 * We write to the data area of the physical eraseblock. Make
258 * sure it has valid EC and VID headers.
260 err = self_check_peb_ec_hdr(ubi, pnum);
263 err = self_check_peb_vid_hdr(ubi, pnum);
268 if (ubi_dbg_is_write_failure(ubi)) {
269 ubi_err("cannot write %d bytes to PEB %d:%d (emulated)",
275 addr = (loff_t)pnum * ubi->peb_size + offset;
276 err = mtd_write(ubi->mtd, addr, len, &written, buf);
278 ubi_err("error %d while writing %d bytes to PEB %d:%d, written %zd bytes",
279 err, len, pnum, offset, written);
281 ubi_dump_flash(ubi, pnum, offset, len);
283 ubi_assert(written == len);
286 err = self_check_write(ubi, buf, pnum, offset, len);
291 * Since we always write sequentially, the rest of the PEB has
292 * to contain only 0xFF bytes.
295 len = ubi->peb_size - offset;
297 err = ubi_self_check_all_ff(ubi, pnum, offset, len);
304 * erase_callback - MTD erasure call-back.
305 * @ei: MTD erase information object.
307 * Note, even though MTD erase interface is asynchronous, all the current
308 * implementations are synchronous anyway.
310 static void erase_callback(struct erase_info *ei)
312 wake_up_interruptible((wait_queue_head_t *)ei->priv);
316 * do_sync_erase - synchronously erase a physical eraseblock.
317 * @ubi: UBI device description object
318 * @pnum: the physical eraseblock number to erase
320 * This function synchronously erases physical eraseblock @pnum and returns
321 * zero in case of success and a negative error code in case of failure. If
322 * %-EIO is returned, the physical eraseblock most probably went bad.
324 static int do_sync_erase(struct ubi_device *ubi, int pnum)
326 int err, retries = 0;
327 struct erase_info ei;
328 wait_queue_head_t wq;
330 dbg_io("erase PEB %d", pnum);
331 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
334 ubi_err("read-only mode");
339 init_waitqueue_head(&wq);
340 memset(&ei, 0, sizeof(struct erase_info));
343 ei.addr = (loff_t)pnum * ubi->peb_size;
344 ei.len = ubi->peb_size;
345 ei.callback = erase_callback;
346 ei.priv = (unsigned long)&wq;
348 err = mtd_erase(ubi->mtd, &ei);
350 if (retries++ < UBI_IO_RETRIES) {
351 ubi_warn("error %d while erasing PEB %d, retry",
356 ubi_err("cannot erase PEB %d, error %d", pnum, err);
361 err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE ||
362 ei.state == MTD_ERASE_FAILED);
364 ubi_err("interrupted PEB %d erasure", pnum);
368 if (ei.state == MTD_ERASE_FAILED) {
369 if (retries++ < UBI_IO_RETRIES) {
370 ubi_warn("error while erasing PEB %d, retry", pnum);
374 ubi_err("cannot erase PEB %d", pnum);
379 err = ubi_self_check_all_ff(ubi, pnum, 0, ubi->peb_size);
383 if (ubi_dbg_is_erase_failure(ubi)) {
384 ubi_err("cannot erase PEB %d (emulated)", pnum);
391 /* Patterns to write to a physical eraseblock when torturing it */
392 static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
395 * torture_peb - test a supposedly bad physical eraseblock.
396 * @ubi: UBI device description object
397 * @pnum: the physical eraseblock number to test
399 * This function returns %-EIO if the physical eraseblock did not pass the
400 * test, a positive number of erase operations done if the test was
401 * successfully passed, and other negative error codes in case of other errors.
403 static int torture_peb(struct ubi_device *ubi, int pnum)
405 int err, i, patt_count;
407 ubi_msg("run torture test for PEB %d", pnum);
408 patt_count = ARRAY_SIZE(patterns);
409 ubi_assert(patt_count > 0);
411 mutex_lock(&ubi->buf_mutex);
412 for (i = 0; i < patt_count; i++) {
413 err = do_sync_erase(ubi, pnum);
417 /* Make sure the PEB contains only 0xFF bytes */
418 err = ubi_io_read(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
422 err = ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->peb_size);
424 ubi_err("erased PEB %d, but a non-0xFF byte found",
430 /* Write a pattern and check it */
431 memset(ubi->peb_buf, patterns[i], ubi->peb_size);
432 err = ubi_io_write(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
436 memset(ubi->peb_buf, ~patterns[i], ubi->peb_size);
437 err = ubi_io_read(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
441 err = ubi_check_pattern(ubi->peb_buf, patterns[i],
444 ubi_err("pattern %x checking failed for PEB %d",
452 ubi_msg("PEB %d passed torture test, do not mark it as bad", pnum);
455 mutex_unlock(&ubi->buf_mutex);
456 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {
458 * If a bit-flip or data integrity error was detected, the test
459 * has not passed because it happened on a freshly erased
460 * physical eraseblock which means something is wrong with it.
462 ubi_err("read problems on freshly erased PEB %d, must be bad",
470 * nor_erase_prepare - prepare a NOR flash PEB for erasure.
471 * @ubi: UBI device description object
472 * @pnum: physical eraseblock number to prepare
474 * NOR flash, or at least some of them, have peculiar embedded PEB erasure
475 * algorithm: the PEB is first filled with zeroes, then it is erased. And
476 * filling with zeroes starts from the end of the PEB. This was observed with
477 * Spansion S29GL512N NOR flash.
479 * This means that in case of a power cut we may end up with intact data at the
480 * beginning of the PEB, and all zeroes at the end of PEB. In other words, the
481 * EC and VID headers are OK, but a large chunk of data at the end of PEB is
482 * zeroed. This makes UBI mistakenly treat this PEB as used and associate it
483 * with an LEB, which leads to subsequent failures (e.g., UBIFS fails).
485 * This function is called before erasing NOR PEBs and it zeroes out EC and VID
486 * magic numbers in order to invalidate them and prevent the failures. Returns
487 * zero in case of success and a negative error code in case of failure.
489 static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
495 struct ubi_ec_hdr ec_hdr;
498 * Note, we cannot generally define VID header buffers on stack,
499 * because of the way we deal with these buffers (see the header
500 * comment in this file). But we know this is a NOR-specific piece of
501 * code, so we can do this. But yes, this is error-prone and we should
502 * (pre-)allocate VID header buffer instead.
504 struct ubi_vid_hdr vid_hdr;
507 * If VID or EC is valid, we have to corrupt them before erasing.
508 * It is important to first invalidate the EC header, and then the VID
509 * header. Otherwise a power cut may lead to valid EC header and
510 * invalid VID header, in which case UBI will treat this PEB as
511 * corrupted and will try to preserve it, and print scary warnings.
513 addr = (loff_t)pnum * ubi->peb_size;
514 err = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
515 if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
517 err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
522 err = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
523 if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
525 addr += ubi->vid_hdr_aloffset;
526 err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
534 * The PEB contains a valid VID or EC header, but we cannot invalidate
535 * it. Supposedly the flash media or the driver is screwed up, so
538 ubi_err("cannot invalidate PEB %d, write returned %d", pnum, err);
539 ubi_dump_flash(ubi, pnum, 0, ubi->peb_size);
544 * ubi_io_sync_erase - synchronously erase a physical eraseblock.
545 * @ubi: UBI device description object
546 * @pnum: physical eraseblock number to erase
547 * @torture: if this physical eraseblock has to be tortured
549 * This function synchronously erases physical eraseblock @pnum. If @torture
550 * flag is not zero, the physical eraseblock is checked by means of writing
551 * different patterns to it and reading them back. If the torturing is enabled,
552 * the physical eraseblock is erased more than once.
554 * This function returns the number of erasures made in case of success, %-EIO
555 * if the erasure failed or the torturing test failed, and other negative error
556 * codes in case of other errors. Note, %-EIO means that the physical
559 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
563 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
565 err = self_check_not_bad(ubi, pnum);
570 ubi_err("read-only mode");
574 if (ubi->nor_flash) {
575 err = nor_erase_prepare(ubi, pnum);
581 ret = torture_peb(ubi, pnum);
586 err = do_sync_erase(ubi, pnum);
594 * ubi_io_is_bad - check if a physical eraseblock is bad.
595 * @ubi: UBI device description object
596 * @pnum: the physical eraseblock number to check
598 * This function returns a positive number if the physical eraseblock is bad,
599 * zero if not, and a negative error code if an error occurred.
601 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
603 struct mtd_info *mtd = ubi->mtd;
605 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
607 if (ubi->bad_allowed) {
610 ret = mtd_block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
612 ubi_err("error %d while checking if PEB %d is bad",
615 dbg_io("PEB %d is bad", pnum);
623 * ubi_io_mark_bad - mark a physical eraseblock as bad.
624 * @ubi: UBI device description object
625 * @pnum: the physical eraseblock number to mark
627 * This function returns zero in case of success and a negative error code in
630 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
633 struct mtd_info *mtd = ubi->mtd;
635 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
638 ubi_err("read-only mode");
642 if (!ubi->bad_allowed)
645 err = mtd_block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
647 ubi_err("cannot mark PEB %d bad, error %d", pnum, err);
652 * validate_ec_hdr - validate an erase counter header.
653 * @ubi: UBI device description object
654 * @ec_hdr: the erase counter header to check
656 * This function returns zero if the erase counter header is OK, and %1 if
659 static int validate_ec_hdr(const struct ubi_device *ubi,
660 const struct ubi_ec_hdr *ec_hdr)
663 int vid_hdr_offset, leb_start;
665 ec = be64_to_cpu(ec_hdr->ec);
666 vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
667 leb_start = be32_to_cpu(ec_hdr->data_offset);
669 if (ec_hdr->version != UBI_VERSION) {
670 ubi_err("node with incompatible UBI version found: this UBI version is %d, image version is %d",
671 UBI_VERSION, (int)ec_hdr->version);
675 if (vid_hdr_offset != ubi->vid_hdr_offset) {
676 ubi_err("bad VID header offset %d, expected %d",
677 vid_hdr_offset, ubi->vid_hdr_offset);
681 if (leb_start != ubi->leb_start) {
682 ubi_err("bad data offset %d, expected %d",
683 leb_start, ubi->leb_start);
687 if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
688 ubi_err("bad erase counter %lld", ec);
695 ubi_err("bad EC header");
696 ubi_dump_ec_hdr(ec_hdr);
702 * ubi_io_read_ec_hdr - read and check an erase counter header.
703 * @ubi: UBI device description object
704 * @pnum: physical eraseblock to read from
705 * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
707 * @verbose: be verbose if the header is corrupted or was not found
709 * This function reads erase counter header from physical eraseblock @pnum and
710 * stores it in @ec_hdr. This function also checks CRC checksum of the read
711 * erase counter header. The following codes may be returned:
713 * o %0 if the CRC checksum is correct and the header was successfully read;
714 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
715 * and corrected by the flash driver; this is harmless but may indicate that
716 * this eraseblock may become bad soon (but may be not);
717 * o %UBI_IO_BAD_HDR if the erase counter header is corrupted (a CRC error);
718 * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
719 * a data integrity error (uncorrectable ECC error in case of NAND);
720 * o %UBI_IO_FF if only 0xFF bytes were read (the PEB is supposedly empty)
721 * o a negative error code in case of failure.
723 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
724 struct ubi_ec_hdr *ec_hdr, int verbose)
727 uint32_t crc, magic, hdr_crc;
729 dbg_io("read EC header from PEB %d", pnum);
730 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
732 read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
734 if (read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
738 * We read all the data, but either a correctable bit-flip
739 * occurred, or MTD reported a data integrity error
740 * (uncorrectable ECC error in case of NAND). The former is
741 * harmless, the later may mean that the read data is
742 * corrupted. But we have a CRC check-sum and we will detect
743 * this. If the EC header is still OK, we just report this as
744 * there was a bit-flip, to force scrubbing.
748 magic = be32_to_cpu(ec_hdr->magic);
749 if (magic != UBI_EC_HDR_MAGIC) {
750 if (mtd_is_eccerr(read_err))
751 return UBI_IO_BAD_HDR_EBADMSG;
754 * The magic field is wrong. Let's check if we have read all
755 * 0xFF. If yes, this physical eraseblock is assumed to be
758 if (ubi_check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
759 /* The physical eraseblock is supposedly empty */
761 ubi_warn("no EC header found at PEB %d, only 0xFF bytes",
763 dbg_bld("no EC header found at PEB %d, only 0xFF bytes",
768 return UBI_IO_FF_BITFLIPS;
772 * This is not a valid erase counter header, and these are not
773 * 0xFF bytes. Report that the header is corrupted.
776 ubi_warn("bad magic number at PEB %d: %08x instead of %08x",
777 pnum, magic, UBI_EC_HDR_MAGIC);
778 ubi_dump_ec_hdr(ec_hdr);
780 dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
781 pnum, magic, UBI_EC_HDR_MAGIC);
782 return UBI_IO_BAD_HDR;
785 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
786 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
788 if (hdr_crc != crc) {
790 ubi_warn("bad EC header CRC at PEB %d, calculated %#08x, read %#08x",
792 ubi_dump_ec_hdr(ec_hdr);
794 dbg_bld("bad EC header CRC at PEB %d, calculated %#08x, read %#08x",
798 return UBI_IO_BAD_HDR;
800 return UBI_IO_BAD_HDR_EBADMSG;
803 /* And of course validate what has just been read from the media */
804 err = validate_ec_hdr(ubi, ec_hdr);
806 ubi_err("validation failed for PEB %d", pnum);
811 * If there was %-EBADMSG, but the header CRC is still OK, report about
812 * a bit-flip to force scrubbing on this PEB.
814 return read_err ? UBI_IO_BITFLIPS : 0;
818 * ubi_io_write_ec_hdr - write an erase counter header.
819 * @ubi: UBI device description object
820 * @pnum: physical eraseblock to write to
821 * @ec_hdr: the erase counter header to write
823 * This function writes erase counter header described by @ec_hdr to physical
824 * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
825 * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
828 * This function returns zero in case of success and a negative error code in
829 * case of failure. If %-EIO is returned, the physical eraseblock most probably
832 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
833 struct ubi_ec_hdr *ec_hdr)
838 dbg_io("write EC header to PEB %d", pnum);
839 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
841 ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
842 ec_hdr->version = UBI_VERSION;
843 ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
844 ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
845 ec_hdr->image_seq = cpu_to_be32(ubi->image_seq);
846 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
847 ec_hdr->hdr_crc = cpu_to_be32(crc);
849 err = self_check_ec_hdr(ubi, pnum, ec_hdr);
853 err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
858 * validate_vid_hdr - validate a volume identifier header.
859 * @ubi: UBI device description object
860 * @vid_hdr: the volume identifier header to check
862 * This function checks that data stored in the volume identifier header
863 * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
865 static int validate_vid_hdr(const struct ubi_device *ubi,
866 const struct ubi_vid_hdr *vid_hdr)
868 int vol_type = vid_hdr->vol_type;
869 int copy_flag = vid_hdr->copy_flag;
870 int vol_id = be32_to_cpu(vid_hdr->vol_id);
871 int lnum = be32_to_cpu(vid_hdr->lnum);
872 int compat = vid_hdr->compat;
873 int data_size = be32_to_cpu(vid_hdr->data_size);
874 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
875 int data_pad = be32_to_cpu(vid_hdr->data_pad);
876 int data_crc = be32_to_cpu(vid_hdr->data_crc);
877 int usable_leb_size = ubi->leb_size - data_pad;
879 if (copy_flag != 0 && copy_flag != 1) {
880 ubi_err("bad copy_flag");
884 if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
886 ubi_err("negative values");
890 if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
891 ubi_err("bad vol_id");
895 if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
896 ubi_err("bad compat");
900 if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
901 compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
902 compat != UBI_COMPAT_REJECT) {
903 ubi_err("bad compat");
907 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
908 ubi_err("bad vol_type");
912 if (data_pad >= ubi->leb_size / 2) {
913 ubi_err("bad data_pad");
917 if (vol_type == UBI_VID_STATIC) {
919 * Although from high-level point of view static volumes may
920 * contain zero bytes of data, but no VID headers can contain
921 * zero at these fields, because they empty volumes do not have
922 * mapped logical eraseblocks.
925 ubi_err("zero used_ebs");
928 if (data_size == 0) {
929 ubi_err("zero data_size");
932 if (lnum < used_ebs - 1) {
933 if (data_size != usable_leb_size) {
934 ubi_err("bad data_size");
937 } else if (lnum == used_ebs - 1) {
938 if (data_size == 0) {
939 ubi_err("bad data_size at last LEB");
943 ubi_err("too high lnum");
947 if (copy_flag == 0) {
949 ubi_err("non-zero data CRC");
952 if (data_size != 0) {
953 ubi_err("non-zero data_size");
957 if (data_size == 0) {
958 ubi_err("zero data_size of copy");
963 ubi_err("bad used_ebs");
971 ubi_err("bad VID header");
972 ubi_dump_vid_hdr(vid_hdr);
978 * ubi_io_read_vid_hdr - read and check a volume identifier header.
979 * @ubi: UBI device description object
980 * @pnum: physical eraseblock number to read from
981 * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
983 * @verbose: be verbose if the header is corrupted or wasn't found
985 * This function reads the volume identifier header from physical eraseblock
986 * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
987 * volume identifier header. The error codes are the same as in
988 * 'ubi_io_read_ec_hdr()'.
990 * Note, the implementation of this function is also very similar to
991 * 'ubi_io_read_ec_hdr()', so refer commentaries in 'ubi_io_read_ec_hdr()'.
993 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
994 struct ubi_vid_hdr *vid_hdr, int verbose)
997 uint32_t crc, magic, hdr_crc;
1000 dbg_io("read VID header from PEB %d", pnum);
1001 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1003 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1004 read_err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1005 ubi->vid_hdr_alsize);
1006 if (read_err && read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
1009 magic = be32_to_cpu(vid_hdr->magic);
1010 if (magic != UBI_VID_HDR_MAGIC) {
1011 if (mtd_is_eccerr(read_err))
1012 return UBI_IO_BAD_HDR_EBADMSG;
1014 if (ubi_check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
1016 ubi_warn("no VID header found at PEB %d, only 0xFF bytes",
1018 dbg_bld("no VID header found at PEB %d, only 0xFF bytes",
1023 return UBI_IO_FF_BITFLIPS;
1027 ubi_warn("bad magic number at PEB %d: %08x instead of %08x",
1028 pnum, magic, UBI_VID_HDR_MAGIC);
1029 ubi_dump_vid_hdr(vid_hdr);
1031 dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
1032 pnum, magic, UBI_VID_HDR_MAGIC);
1033 return UBI_IO_BAD_HDR;
1036 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1037 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1039 if (hdr_crc != crc) {
1041 ubi_warn("bad CRC at PEB %d, calculated %#08x, read %#08x",
1042 pnum, crc, hdr_crc);
1043 ubi_dump_vid_hdr(vid_hdr);
1045 dbg_bld("bad CRC at PEB %d, calculated %#08x, read %#08x",
1046 pnum, crc, hdr_crc);
1048 return UBI_IO_BAD_HDR;
1050 return UBI_IO_BAD_HDR_EBADMSG;
1053 err = validate_vid_hdr(ubi, vid_hdr);
1055 ubi_err("validation failed for PEB %d", pnum);
1059 return read_err ? UBI_IO_BITFLIPS : 0;
1063 * ubi_io_write_vid_hdr - write a volume identifier header.
1064 * @ubi: UBI device description object
1065 * @pnum: the physical eraseblock number to write to
1066 * @vid_hdr: the volume identifier header to write
1068 * This function writes the volume identifier header described by @vid_hdr to
1069 * physical eraseblock @pnum. This function automatically fills the
1070 * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates
1071 * header CRC checksum and stores it at vid_hdr->hdr_crc.
1073 * This function returns zero in case of success and a negative error code in
1074 * case of failure. If %-EIO is returned, the physical eraseblock probably went
1077 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
1078 struct ubi_vid_hdr *vid_hdr)
1084 dbg_io("write VID header to PEB %d", pnum);
1085 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1087 err = self_check_peb_ec_hdr(ubi, pnum);
1091 vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
1092 vid_hdr->version = UBI_VERSION;
1093 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1094 vid_hdr->hdr_crc = cpu_to_be32(crc);
1096 err = self_check_vid_hdr(ubi, pnum, vid_hdr);
1100 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1101 err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
1102 ubi->vid_hdr_alsize);
1107 * self_check_not_bad - ensure that a physical eraseblock is not bad.
1108 * @ubi: UBI device description object
1109 * @pnum: physical eraseblock number to check
1111 * This function returns zero if the physical eraseblock is good, %-EINVAL if
1112 * it is bad and a negative error code if an error occurred.
1114 static int self_check_not_bad(const struct ubi_device *ubi, int pnum)
1118 if (!ubi_dbg_chk_io(ubi))
1121 err = ubi_io_is_bad(ubi, pnum);
1125 ubi_err("self-check failed for PEB %d", pnum);
1127 return err > 0 ? -EINVAL : err;
1131 * self_check_ec_hdr - check if an erase counter header is all right.
1132 * @ubi: UBI device description object
1133 * @pnum: physical eraseblock number the erase counter header belongs to
1134 * @ec_hdr: the erase counter header to check
1136 * This function returns zero if the erase counter header contains valid
1137 * values, and %-EINVAL if not.
1139 static int self_check_ec_hdr(const struct ubi_device *ubi, int pnum,
1140 const struct ubi_ec_hdr *ec_hdr)
1145 if (!ubi_dbg_chk_io(ubi))
1148 magic = be32_to_cpu(ec_hdr->magic);
1149 if (magic != UBI_EC_HDR_MAGIC) {
1150 ubi_err("bad magic %#08x, must be %#08x",
1151 magic, UBI_EC_HDR_MAGIC);
1155 err = validate_ec_hdr(ubi, ec_hdr);
1157 ubi_err("self-check failed for PEB %d", pnum);
1164 ubi_dump_ec_hdr(ec_hdr);
1170 * self_check_peb_ec_hdr - check erase counter header.
1171 * @ubi: UBI device description object
1172 * @pnum: the physical eraseblock number to check
1174 * This function returns zero if the erase counter header is all right and and
1175 * a negative error code if not or if an error occurred.
1177 static int self_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
1180 uint32_t crc, hdr_crc;
1181 struct ubi_ec_hdr *ec_hdr;
1183 if (!ubi_dbg_chk_io(ubi))
1186 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
1190 err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
1191 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
1194 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
1195 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
1196 if (hdr_crc != crc) {
1197 ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc);
1198 ubi_err("self-check failed for PEB %d", pnum);
1199 ubi_dump_ec_hdr(ec_hdr);
1205 err = self_check_ec_hdr(ubi, pnum, ec_hdr);
1213 * self_check_vid_hdr - check that a volume identifier header is all right.
1214 * @ubi: UBI device description object
1215 * @pnum: physical eraseblock number the volume identifier header belongs to
1216 * @vid_hdr: the volume identifier header to check
1218 * This function returns zero if the volume identifier header is all right, and
1221 static int self_check_vid_hdr(const struct ubi_device *ubi, int pnum,
1222 const struct ubi_vid_hdr *vid_hdr)
1227 if (!ubi_dbg_chk_io(ubi))
1230 magic = be32_to_cpu(vid_hdr->magic);
1231 if (magic != UBI_VID_HDR_MAGIC) {
1232 ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
1233 magic, pnum, UBI_VID_HDR_MAGIC);
1237 err = validate_vid_hdr(ubi, vid_hdr);
1239 ubi_err("self-check failed for PEB %d", pnum);
1246 ubi_err("self-check failed for PEB %d", pnum);
1247 ubi_dump_vid_hdr(vid_hdr);
1254 * self_check_peb_vid_hdr - check volume identifier header.
1255 * @ubi: UBI device description object
1256 * @pnum: the physical eraseblock number to check
1258 * This function returns zero if the volume identifier header is all right,
1259 * and a negative error code if not or if an error occurred.
1261 static int self_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
1264 uint32_t crc, hdr_crc;
1265 struct ubi_vid_hdr *vid_hdr;
1268 if (!ubi_dbg_chk_io(ubi))
1271 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
1275 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1276 err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1277 ubi->vid_hdr_alsize);
1278 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
1281 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC);
1282 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1283 if (hdr_crc != crc) {
1284 ubi_err("bad VID header CRC at PEB %d, calculated %#08x, read %#08x",
1285 pnum, crc, hdr_crc);
1286 ubi_err("self-check failed for PEB %d", pnum);
1287 ubi_dump_vid_hdr(vid_hdr);
1293 err = self_check_vid_hdr(ubi, pnum, vid_hdr);
1296 ubi_free_vid_hdr(ubi, vid_hdr);
1301 * self_check_write - make sure write succeeded.
1302 * @ubi: UBI device description object
1303 * @buf: buffer with data which were written
1304 * @pnum: physical eraseblock number the data were written to
1305 * @offset: offset within the physical eraseblock the data were written to
1306 * @len: how many bytes were written
1308 * This functions reads data which were recently written and compares it with
1309 * the original data buffer - the data have to match. Returns zero if the data
1310 * match and a negative error code if not or in case of failure.
1312 static int self_check_write(struct ubi_device *ubi, const void *buf, int pnum,
1313 int offset, int len)
1318 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1320 if (!ubi_dbg_chk_io(ubi))
1323 buf1 = __vmalloc(len, GFP_NOFS, PAGE_KERNEL);
1325 ubi_err("cannot allocate memory to check writes");
1329 err = mtd_read(ubi->mtd, addr, len, &read, buf1);
1330 if (err && !mtd_is_bitflip(err))
1333 for (i = 0; i < len; i++) {
1334 uint8_t c = ((uint8_t *)buf)[i];
1335 uint8_t c1 = ((uint8_t *)buf1)[i];
1336 #if !defined(CONFIG_UBI_SILENCE_MSG)
1337 int dump_len = max_t(int, 128, len - i);
1343 ubi_err("self-check failed for PEB %d:%d, len %d",
1345 ubi_msg("data differ at position %d", i);
1346 ubi_msg("hex dump of the original buffer from %d to %d",
1348 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1349 buf + i, dump_len, 1);
1350 ubi_msg("hex dump of the read buffer from %d to %d",
1352 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1353 buf1 + i, dump_len, 1);
1368 * ubi_self_check_all_ff - check that a region of flash is empty.
1369 * @ubi: UBI device description object
1370 * @pnum: the physical eraseblock number to check
1371 * @offset: the starting offset within the physical eraseblock to check
1372 * @len: the length of the region to check
1374 * This function returns zero if only 0xFF bytes are present at offset
1375 * @offset of the physical eraseblock @pnum, and a negative error code if not
1376 * or if an error occurred.
1378 int ubi_self_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
1383 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1385 if (!ubi_dbg_chk_io(ubi))
1388 buf = __vmalloc(len, GFP_NOFS, PAGE_KERNEL);
1390 ubi_err("cannot allocate memory to check for 0xFFs");
1394 err = mtd_read(ubi->mtd, addr, len, &read, buf);
1395 if (err && !mtd_is_bitflip(err)) {
1396 ubi_err("error %d while reading %d bytes from PEB %d:%d, read %zd bytes",
1397 err, len, pnum, offset, read);
1401 err = ubi_check_pattern(buf, 0xFF, len);
1403 ubi_err("flash region at PEB %d:%d, length %d does not contain all 0xFF bytes",
1412 ubi_err("self-check failed for PEB %d", pnum);
1413 ubi_msg("hex dump of the %d-%d region", offset, offset + len);
1414 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);