io.c

uboot200903最新版本的通用uboot

		}
	} else {
		if (copy_flag == 0) {
			if (data_crc != 0) {
				dbg_err("non-zero data CRC");
				goto bad;
			}
			if (data_size != 0) {
				dbg_err("non-zero data_size");
				goto bad;
			}
		} else {
			if (data_size == 0) {
				dbg_err("zero data_size of copy");
				goto bad;
			}
		}
		if (used_ebs != 0) {
			dbg_err("bad used_ebs");
			goto bad;
		}
	}

	return 0;

bad:
	ubi_err("bad VID header");
	ubi_dbg_dump_vid_hdr(vid_hdr);
	ubi_dbg_dump_stack();
	return 1;
}

/**
 * ubi_io_read_vid_hdr - read and check a volume identifier header.
 * @ubi: UBI device description object
 * @pnum: physical eraseblock number to read from
 * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
 * identifier header
 * @verbose: be verbose if the header is corrupted or wasn't found
 *
 * This function reads the volume identifier header from physical eraseblock
 * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
 * volume identifier header. The following codes may be returned:
 *
 * o %0 if the CRC checksum is correct and the header was successfully read;
 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
 *   and corrected by the flash driver; this is harmless but may indicate that
 *   this eraseblock may become bad soon;
 * o %UBI_IO_BAD_VID_HRD if the volume identifier header is corrupted (a CRC
 *   error detected);
 * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID
 *   header there);
 * o a negative error code in case of failure.
 */
int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
			struct ubi_vid_hdr *vid_hdr, int verbose)
{
	int err, read_err = 0;
	uint32_t crc, magic, hdr_crc;
	void *p;

	dbg_io("read VID header from PEB %d", pnum);
	ubi_assert(pnum >= 0 &&  pnum < ubi->peb_count);
	if (UBI_IO_DEBUG)
		verbose = 1;

	p = (char *)vid_hdr - ubi->vid_hdr_shift;
	err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
			  ubi->vid_hdr_alsize);
	if (err) {
		if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
			return err;

		/*
		 * We read all the data, but either a correctable bit-flip
		 * occurred, or MTD reported about some data integrity error,
		 * like an ECC error in case of NAND. The former is harmless,
		 * the later may mean the read data is corrupted. But we have a
		 * CRC check-sum and we will identify this. If the VID header is
		 * still OK, we just report this as there was a bit-flip.
		 */
		read_err = err;
	}

	magic = be32_to_cpu(vid_hdr->magic);
	if (magic != UBI_VID_HDR_MAGIC) {
		/*
		 * If we have read all 0xFF bytes, the VID header probably does
		 * not exist and the physical eraseblock is assumed to be free.
		 *
		 * But if there was a read error, we do not test the data for
		 * 0xFFs. Even if it does contain all 0xFFs, this error
		 * indicates that something is still wrong with this physical
		 * eraseblock and it cannot be regarded as free.
		 */
		if (read_err != -EBADMSG &&
		    check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
			/* The physical eraseblock is supposedly free */

			/*
			 * The below is just a paranoid check, it has to be
			 * compiled out if paranoid checks are disabled.
			 */
			err = paranoid_check_all_ff(ubi, pnum, ubi->leb_start,
						    ubi->leb_size);
			if (err)
				return err > 0 ? UBI_IO_BAD_VID_HDR : err;

			if (verbose)
				ubi_warn("no VID header found at PEB %d, "
					 "only 0xFF bytes", pnum);
			return UBI_IO_PEB_FREE;
		}

		/*
		 * This is not a valid VID header, and these are not 0xFF
		 * bytes. Report that the header is corrupted.
		 */
		if (verbose) {
			ubi_warn("bad magic number at PEB %d: %08x instead of "
				 "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
			ubi_dbg_dump_vid_hdr(vid_hdr);
		}
		return UBI_IO_BAD_VID_HDR;
	}

	crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
	hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);

	if (hdr_crc != crc) {
		if (verbose) {
			ubi_warn("bad CRC at PEB %d, calculated %#08x, "
				 "read %#08x", pnum, crc, hdr_crc);
			ubi_dbg_dump_vid_hdr(vid_hdr);
		}
		return UBI_IO_BAD_VID_HDR;
	}

	/* Validate the VID header that we have just read */
	err = validate_vid_hdr(ubi, vid_hdr);
	if (err) {
		ubi_err("validation failed for PEB %d", pnum);
		return -EINVAL;
	}

	return read_err ? UBI_IO_BITFLIPS : 0;
}

/**
 * ubi_io_write_vid_hdr - write a volume identifier header.
 * @ubi: UBI device description object
 * @pnum: the physical eraseblock number to write to
 * @vid_hdr: the volume identifier header to write
 *
 * This function writes the volume identifier header described by @vid_hdr to
 * physical eraseblock @pnum. This function automatically fills the
 * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates
 * header CRC checksum and stores it at vid_hdr->hdr_crc.
 *
 * This function returns zero in case of success and a negative error code in
 * case of failure. If %-EIO is returned, the physical eraseblock probably went
 * bad.
 */
int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
			 struct ubi_vid_hdr *vid_hdr)
{
	int err;
	uint32_t crc;
	void *p;

	dbg_io("write VID header to PEB %d", pnum);
	ubi_assert(pnum >= 0 &&  pnum < ubi->peb_count);

	err = paranoid_check_peb_ec_hdr(ubi, pnum);
	if (err)
		return err > 0 ? -EINVAL: err;

	vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
	vid_hdr->version = UBI_VERSION;
	crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
	vid_hdr->hdr_crc = cpu_to_be32(crc);

	err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
	if (err)
		return -EINVAL;

	p = (char *)vid_hdr - ubi->vid_hdr_shift;
	err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
			   ubi->vid_hdr_alsize);
	return err;
}

#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID

/**
 * paranoid_check_not_bad - ensure that a physical eraseblock is not bad.
 * @ubi: UBI device description object
 * @pnum: physical eraseblock number to check
 *
 * This function returns zero if the physical eraseblock is good, a positive
 * number if it is bad and a negative error code if an error occurred.
 */
static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum)
{
	int err;

	err = ubi_io_is_bad(ubi, pnum);
	if (!err)
		return err;

	ubi_err("paranoid check failed for PEB %d", pnum);
	ubi_dbg_dump_stack();
	return err;
}

/**
 * paranoid_check_ec_hdr - check if an erase counter header is all right.
 * @ubi: UBI device description object
 * @pnum: physical eraseblock number the erase counter header belongs to
 * @ec_hdr: the erase counter header to check
 *
 * This function returns zero if the erase counter header contains valid
 * values, and %1 if not.
 */
static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
				 const struct ubi_ec_hdr *ec_hdr)
{
	int err;
	uint32_t magic;

	magic = be32_to_cpu(ec_hdr->magic);
	if (magic != UBI_EC_HDR_MAGIC) {
		ubi_err("bad magic %#08x, must be %#08x",
			magic, UBI_EC_HDR_MAGIC);
		goto fail;
	}

	err = validate_ec_hdr(ubi, ec_hdr);
	if (err) {
		ubi_err("paranoid check failed for PEB %d", pnum);
		goto fail;
	}

	return 0;

fail:
	ubi_dbg_dump_ec_hdr(ec_hdr);
	ubi_dbg_dump_stack();
	return 1;
}

/**
 * paranoid_check_peb_ec_hdr - check that the erase counter header of a
 * physical eraseblock is in-place and is all right.
 * @ubi: UBI device description object
 * @pnum: the physical eraseblock number to check
 *
 * This function returns zero if the erase counter header is all right, %1 if
 * not, and a negative error code if an error occurred.
 */
static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
{
	int err;
	uint32_t crc, hdr_crc;
	struct ubi_ec_hdr *ec_hdr;

	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
	if (!ec_hdr)
		return -ENOMEM;

	err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
	if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
		goto exit;

	crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
	hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
	if (hdr_crc != crc) {
		ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc);
		ubi_err("paranoid check failed for PEB %d", pnum);
		ubi_dbg_dump_ec_hdr(ec_hdr);
		ubi_dbg_dump_stack();
		err = 1;
		goto exit;
	}

	err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);

exit:
	kfree(ec_hdr);
	return err;
}

/**
 * paranoid_check_vid_hdr - check that a volume identifier header is all right.
 * @ubi: UBI device description object
 * @pnum: physical eraseblock number the volume identifier header belongs to
 * @vid_hdr: the volume identifier header to check
 *
 * This function returns zero if the volume identifier header is all right, and
 * %1 if not.
 */
static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
				  const struct ubi_vid_hdr *vid_hdr)
{
	int err;
	uint32_t magic;

	magic = be32_to_cpu(vid_hdr->magic);
	if (magic != UBI_VID_HDR_MAGIC) {
		ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
			magic, pnum, UBI_VID_HDR_MAGIC);
		goto fail;
	}

	err = validate_vid_hdr(ubi, vid_hdr);
	if (err) {
		ubi_err("paranoid check failed for PEB %d", pnum);
		goto fail;
	}

	return err;

fail:
	ubi_err("paranoid check failed for PEB %d", pnum);
	ubi_dbg_dump_vid_hdr(vid_hdr);
	ubi_dbg_dump_stack();
	return 1;

}

/**
 * paranoid_check_peb_vid_hdr - check that the volume identifier header of a
 * physical eraseblock is in-place and is all right.
 * @ubi: UBI device description object
 * @pnum: the physical eraseblock number to check
 *
 * This function returns zero if the volume identifier header is all right,
 * %1 if not, and a negative error code if an error occurred.
 */
static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
{
	int err;
	uint32_t crc, hdr_crc;
	struct ubi_vid_hdr *vid_hdr;
	void *p;

	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
	if (!vid_hdr)
		return -ENOMEM;

	p = (char *)vid_hdr - ubi->vid_hdr_shift;
	err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
			  ubi->vid_hdr_alsize);
	if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
		goto exit;

	crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC);
	hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
	if (hdr_crc != crc) {
		ubi_err("bad VID header CRC at PEB %d, calculated %#08x, "
			"read %#08x", pnum, crc, hdr_crc);
		ubi_err("paranoid check failed for PEB %d", pnum);
		ubi_dbg_dump_vid_hdr(vid_hdr);
		ubi_dbg_dump_stack();
		err = 1;
		goto exit;
	}

	err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);

exit:
	ubi_free_vid_hdr(ubi, vid_hdr);
	return err;
}

/**
 * paranoid_check_all_ff - check that a region of flash is empty.
 * @ubi: UBI device description object
 * @pnum: the physical eraseblock number to check
 * @offset: the starting offset within the physical eraseblock to check
 * @len: the length of the region to check
 *
 * This function returns zero if only 0xFF bytes are present at offset
 * @offset of the physical eraseblock @pnum, %1 if not, and a negative error
 * code if an error occurred.
 */
static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
				 int len)
{
	size_t read;
	int err;
	loff_t addr = (loff_t)pnum * ubi->peb_size + offset;

	mutex_lock(&ubi->dbg_buf_mutex);
	err = ubi->mtd->read(ubi->mtd, addr, len, &read, ubi->dbg_peb_buf);
	if (err && err != -EUCLEAN) {
		ubi_err("error %d while reading %d bytes from PEB %d:%d, "
			"read %zd bytes", err, len, pnum, offset, read);
		goto error;
	}

	err = check_pattern(ubi->dbg_peb_buf, 0xFF, len);
	if (err == 0) {
		ubi_err("flash region at PEB %d:%d, length %d does not "
			"contain all 0xFF bytes", pnum, offset, len);
		goto fail;
	}
	mutex_unlock(&ubi->dbg_buf_mutex);

	return 0;

fail:
	ubi_err("paranoid check failed for PEB %d", pnum);
	dbg_msg("hex dump of the %d-%d region", offset, offset + len);
	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
		       ubi->dbg_peb_buf, len, 1);
	err = 1;
error:
	ubi_dbg_dump_stack();
	mutex_unlock(&ubi->dbg_buf_mutex);
	return err;
}

#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */