On Wed, Jun 15, 2022 at 02:06:11AM +0200, Ansuel Smith wrote:
> IPQ8064 nand have special pages where a different layout scheme is used.
> These special page are used by boot partition and on reading them
> lots of warning are reported about wrong ECC data and if written to
> results in broken data and not bootable device.
>
> The layout scheme used by these special page consist in using 512 bytes
> as the codeword size (even for the last codeword) while writing to CFG0
> register. This forces the NAND controller to unprotect the 4 bytes of
> spare data.
>
> Since the kernel is unaware of this different layout for these special
> page, it does try to protect the spare data too during read/write and
> warn about CRC errors.
>
> Add support for this by permitting the user to declare these special
> pages in dts by declaring offset and size of the partition. The driver
> internally will convert these value to nand pages.
>
> On user read/write the page is checked and if it's a boot page the
> correct layout is used.
>
> Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
Just a few nitpicks below. With those fixed,
Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Thanks,
Mani
> ---
> drivers/mtd/nand/raw/qcom_nandc.c | 203 +++++++++++++++++++++++++++++-
> 1 file changed, 198 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index f2990d721733..0dbfe32888ff 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
[...]
> +static bool qcom_nandc_is_boot_partition(struct qcom_nand_host *host, int page)
> +{
> + struct qcom_nand_boot_partition *boot_partition;
> + u32 start, end;
> + int i;
> +
> + /*
> + * Since the frequent access will be to the non-boot partitions like rootfs,
> + * optimize the page check by:
> +
Missing "*"
> + * 1. Checking if the page lies after the last boot partition.
> + * 2. Checking from the boot partition end.
> + */
> +
> + /* First check the last boot partition */
> + boot_partition = &host->boot_partitions[host->nr_boot_partitions - 1];
> + start = boot_partition->page_offset;
> + end = start + boot_partition->page_size;
> +
> + /* Page is after the last boot partition end. This is NOT a boot partition */
> + if (page > end)
> + return false;
> +
> + /* Actually check if it's a boot partition */
> + if (page < end && page >= start)
> + return true;
> +
> + /* Check the other boot partition starting from the second-last partition */
s/boot partition/boot partitions
> + for (i = host->nr_boot_partitions - 2; i >= 0; i--) {
> + boot_partition = &host->boot_partitions[i];
> + start = boot_partition->page_offset;
> + end = start + boot_partition->page_size;
> +
> + if (page < end && page >= start)
> + return true;
> + }
> +
> + return false;
> +}
> +
> +static void
> +qcom_nandc_codeword_fixup(struct qcom_nand_host *host, int page)
As like other functions, please align the function on the same line
> +{
> + bool codeword_fixup = qcom_nandc_is_boot_partition(host, page);
> +
> + /* Skip conf write if we are already in the correct mode */
> + if (codeword_fixup == host->codeword_fixup)
> + return;
> +
> + host->codeword_fixup = codeword_fixup;
> +
> + host->cw_data = codeword_fixup ? 512 : 516;
> + host->spare_bytes = host->cw_size - host->ecc_bytes_hw -
> + host->bbm_size - host->cw_data;
> +
> + host->cfg0 &= ~(SPARE_SIZE_BYTES_MASK | UD_SIZE_BYTES_MASK);
> + host->cfg0 |= host->spare_bytes << SPARE_SIZE_BYTES |
> + host->cw_data << UD_SIZE_BYTES;
> +
> + host->ecc_bch_cfg &= ~ECC_NUM_DATA_BYTES_MASK;
> + host->ecc_bch_cfg |= host->cw_data << ECC_NUM_DATA_BYTES;
> + host->ecc_buf_cfg = (host->cw_data - 1) << NUM_STEPS;
> +}
[...]
> +static int qcom_nand_host_parse_boot_partitions(struct qcom_nand_controller *nandc,
> + struct qcom_nand_host *host,
> + struct device_node *dn)
> +{
> + struct nand_chip *chip = &host->chip;
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + struct qcom_nand_boot_partition *boot_partition;
> + struct device *dev = nandc->dev;
> + int partitions_count, i, j, ret;
> +
> + if (!of_find_property(dn, "qcom,boot-partitions", NULL))
> + return 0;
> +
> + partitions_count = of_property_count_u32_elems(dn, "qcom,boot-partitions");
> + if (partitions_count <= 0) {
> + dev_err(dev, "Error parsing boot partition\n");
> + if (partitions_count == 0)
> + return -EINVAL;
> + else
> + return partitions_count;
return partitions_count ? partitions_count : -EINVAL;
Thanks,
Mani
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