[PATCH v13 09/20] mtd: rawnand: Separate the ECC engine type and the ECC byte placement

Han Xu xhnjupt at gmail.com
Wed Oct 14 17:36:35 EDT 2020


On Thu, Aug 27, 2020 at 3:55 AM Miquel Raynal <miquel.raynal at bootlin.com> wrote:
>
> The use of "syndrome" placement should not be encoded in the ECC
> engine mode/type.
>
> Create a "placement" field in NAND chip and change all occurrences of
> the NAND_ECC_HW_SYNDROME enumeration to be just NAND_ECC_HW and
> possibly a placement entry like NAND_ECC_PLACEMENT_INTERLEAVED.
>
> Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
> Reviewed-by: Boris Brezillon <boris.brezillon at collabora.com>
> ---
>  arch/arm/mach-davinci/board-dm355-leopard.c |   3 +-
>  drivers/mtd/nand/raw/cafe_nand.c            |   3 +-
>  drivers/mtd/nand/raw/davinci_nand.c         |   5 +-
>  drivers/mtd/nand/raw/denali.c               |   3 +-
>  drivers/mtd/nand/raw/diskonchip.c           |   3 +-
>  drivers/mtd/nand/raw/lpc32xx_slc.c          |   3 +-
>  drivers/mtd/nand/raw/nand_base.c            | 109 +++++++++++---------
>  drivers/mtd/nand/raw/r852.c                 |   3 +-
>  include/linux/mtd/rawnand.h                 |   6 +-
>  include/linux/platform_data/mtd-davinci.h   |   1 +
>  10 files changed, 81 insertions(+), 58 deletions(-)
>
> diff --git a/arch/arm/mach-davinci/board-dm355-leopard.c b/arch/arm/mach-davinci/board-dm355-leopard.c
> index b9e9950dd300..4c8a592754ac 100644
> --- a/arch/arm/mach-davinci/board-dm355-leopard.c
> +++ b/arch/arm/mach-davinci/board-dm355-leopard.c
> @@ -76,7 +76,8 @@ static struct davinci_nand_pdata davinci_nand_data = {
>         .mask_chipsel           = BIT(14),
>         .parts                  = davinci_nand_partitions,
>         .nr_parts               = ARRAY_SIZE(davinci_nand_partitions),
> -       .ecc_mode               = NAND_ECC_HW_SYNDROME,
> +       .ecc_mode               = NAND_HW_ECC_ENGINE,
> +       .ecc_placement          = NAND_ECC_PLACEMENT_INTERLEAVED,
>         .ecc_bits               = 4,
>         .bbt_options            = NAND_BBT_USE_FLASH,
>  };
> diff --git a/drivers/mtd/nand/raw/cafe_nand.c b/drivers/mtd/nand/raw/cafe_nand.c
> index 92173790f20b..2bf8ab542e38 100644
> --- a/drivers/mtd/nand/raw/cafe_nand.c
> +++ b/drivers/mtd/nand/raw/cafe_nand.c
> @@ -629,7 +629,8 @@ static int cafe_nand_attach_chip(struct nand_chip *chip)
>                 goto out_free_dma;
>         }
>
> -       cafe->nand.ecc.mode = NAND_ECC_HW_SYNDROME;
> +       cafe->nand.ecc.mode = NAND_ECC_HW;
> +       cafe->nand.ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
>         cafe->nand.ecc.size = mtd->writesize;
>         cafe->nand.ecc.bytes = 14;
>         cafe->nand.ecc.strength = 4;
> diff --git a/drivers/mtd/nand/raw/davinci_nand.c b/drivers/mtd/nand/raw/davinci_nand.c
> index 551515c223bb..3640c7e45e15 100644
> --- a/drivers/mtd/nand/raw/davinci_nand.c
> +++ b/drivers/mtd/nand/raw/davinci_nand.c
> @@ -168,7 +168,7 @@ static int nand_davinci_correct_1bit(struct nand_chip *chip, u_char *dat,
>  /*
>   * 4-bit hardware ECC ... context maintained over entire AEMIF
>   *
> - * This is a syndrome engine, but we avoid NAND_ECC_HW_SYNDROME
> + * This is a syndrome engine, but we avoid NAND_ECC_PLACEMENT_INTERLEAVED
>   * since that forces use of a problematic "infix OOB" layout.
>   * Among other things, it trashes manufacturer bad block markers.
>   * Also, and specific to this hardware, it ECC-protects the "prepad"
> @@ -851,6 +851,7 @@ static int nand_davinci_probe(struct platform_device *pdev)
>
>         /* Use board-specific ECC config */
>         info->chip.ecc.mode     = pdata->ecc_mode;
> +       info->chip.ecc.placement = pdata->ecc_placement;
>
>         spin_lock_irq(&davinci_nand_lock);
>
> @@ -897,7 +898,7 @@ static int nand_davinci_remove(struct platform_device *pdev)
>         int ret;
>
>         spin_lock_irq(&davinci_nand_lock);
> -       if (info->chip.ecc.mode == NAND_ECC_HW_SYNDROME)
> +       if (info->chip.ecc.placement == NAND_ECC_PLACEMENT_INTERLEAVED)
>                 ecc4_busy = false;
>         spin_unlock_irq(&davinci_nand_lock);
>
> diff --git a/drivers/mtd/nand/raw/denali.c b/drivers/mtd/nand/raw/denali.c
> index 9d99dade95ce..0e54b8a61cf0 100644
> --- a/drivers/mtd/nand/raw/denali.c
> +++ b/drivers/mtd/nand/raw/denali.c
> @@ -1237,7 +1237,8 @@ int denali_chip_init(struct denali_controller *denali,
>         chip->bbt_options |= NAND_BBT_USE_FLASH;
>         chip->bbt_options |= NAND_BBT_NO_OOB;
>         chip->options |= NAND_NO_SUBPAGE_WRITE;
> -       chip->ecc.mode = NAND_ECC_HW_SYNDROME;
> +       chip->ecc.mode = NAND_ECC_HW;
> +       chip->ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
>         chip->ecc.read_page = denali_read_page;
>         chip->ecc.write_page = denali_write_page;
>         chip->ecc.read_page_raw = denali_read_page_raw;
> diff --git a/drivers/mtd/nand/raw/diskonchip.c b/drivers/mtd/nand/raw/diskonchip.c
> index 43721863a0d8..40360352136b 100644
> --- a/drivers/mtd/nand/raw/diskonchip.c
> +++ b/drivers/mtd/nand/raw/diskonchip.c
> @@ -1456,7 +1456,8 @@ static int __init doc_probe(unsigned long physadr)
>         nand->ecc.calculate     = doc200x_calculate_ecc;
>         nand->ecc.correct       = doc200x_correct_data;
>
> -       nand->ecc.mode          = NAND_ECC_HW_SYNDROME;
> +       nand->ecc.mode          = NAND_ECC_HW;
> +       nand->ecc.placement     = NAND_ECC_PLACEMENT_INTERLEAVED;
>         nand->ecc.size          = 512;
>         nand->ecc.bytes         = 6;
>         nand->ecc.strength      = 2;
> diff --git a/drivers/mtd/nand/raw/lpc32xx_slc.c b/drivers/mtd/nand/raw/lpc32xx_slc.c
> index b151fd000815..ccb189c8e343 100644
> --- a/drivers/mtd/nand/raw/lpc32xx_slc.c
> +++ b/drivers/mtd/nand/raw/lpc32xx_slc.c
> @@ -881,7 +881,8 @@ static int lpc32xx_nand_probe(struct platform_device *pdev)
>         platform_set_drvdata(pdev, host);
>
>         /* NAND callbacks for LPC32xx SLC hardware */
> -       chip->ecc.mode = NAND_ECC_HW_SYNDROME;
> +       chip->ecc.mode = NAND_ECC_HW;
> +       chip->ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
>         chip->legacy.read_byte = lpc32xx_nand_read_byte;
>         chip->legacy.read_buf = lpc32xx_nand_read_buf;
>         chip->legacy.write_buf = lpc32xx_nand_write_buf;
> diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
> index 1d403b439850..5e1f4c1faec0 100644
> --- a/drivers/mtd/nand/raw/nand_base.c
> +++ b/drivers/mtd/nand/raw/nand_base.c
> @@ -5795,61 +5795,74 @@ static int nand_scan_tail(struct nand_chip *chip)
>
>         switch (ecc->mode) {
>         case NAND_ECC_HW:
> -               /* Use standard hwecc read page function? */
> -               if (!ecc->read_page)
> -                       ecc->read_page = nand_read_page_hwecc;
> -               if (!ecc->write_page)
> -                       ecc->write_page = nand_write_page_hwecc;
> -               if (!ecc->read_page_raw)
> -                       ecc->read_page_raw = nand_read_page_raw;
> -               if (!ecc->write_page_raw)
> -                       ecc->write_page_raw = nand_write_page_raw;
> -               if (!ecc->read_oob)
> -                       ecc->read_oob = nand_read_oob_std;
> -               if (!ecc->write_oob)
> -                       ecc->write_oob = nand_write_oob_std;
> -               if (!ecc->read_subpage)
> -                       ecc->read_subpage = nand_read_subpage;
> -               if (!ecc->write_subpage && ecc->hwctl && ecc->calculate)
> -                       ecc->write_subpage = nand_write_subpage_hwecc;
> -               fallthrough;
> -       case NAND_ECC_HW_SYNDROME:
> -               if ((!ecc->calculate || !ecc->correct || !ecc->hwctl) &&
> -                   (!ecc->read_page ||
> -                    ecc->read_page == nand_read_page_hwecc ||
> -                    !ecc->write_page ||
> -                    ecc->write_page == nand_write_page_hwecc)) {
> -                       WARN(1, "No ECC functions supplied; hardware ECC not possible\n");
> -                       ret = -EINVAL;
> -                       goto err_nand_manuf_cleanup;
> -               }
> -               /* Use standard syndrome read/write page function? */
> -               if (!ecc->read_page)
> -                       ecc->read_page = nand_read_page_syndrome;
> -               if (!ecc->write_page)
> -                       ecc->write_page = nand_write_page_syndrome;
> -               if (!ecc->read_page_raw)
> -                       ecc->read_page_raw = nand_read_page_raw_syndrome;
> -               if (!ecc->write_page_raw)
> -                       ecc->write_page_raw = nand_write_page_raw_syndrome;
> -               if (!ecc->read_oob)
> -                       ecc->read_oob = nand_read_oob_syndrome;
> -               if (!ecc->write_oob)
> -                       ecc->write_oob = nand_write_oob_syndrome;
> +               switch (ecc->placement) {
> +               case NAND_ECC_PLACEMENT_UNKNOWN:
> +               case NAND_ECC_PLACEMENT_OOB:
> +                       /* Use standard hwecc read page function? */
> +                       if (!ecc->read_page)
> +                               ecc->read_page = nand_read_page_hwecc;
> +                       if (!ecc->write_page)
> +                               ecc->write_page = nand_write_page_hwecc;
> +                       if (!ecc->read_page_raw)
> +                               ecc->read_page_raw = nand_read_page_raw;
> +                       if (!ecc->write_page_raw)
> +                               ecc->write_page_raw = nand_write_page_raw;
> +                       if (!ecc->read_oob)
> +                               ecc->read_oob = nand_read_oob_std;
> +                       if (!ecc->write_oob)
> +                               ecc->write_oob = nand_write_oob_std;
> +                       if (!ecc->read_subpage)
> +                               ecc->read_subpage = nand_read_subpage;
> +                       if (!ecc->write_subpage && ecc->hwctl && ecc->calculate)
> +                               ecc->write_subpage = nand_write_subpage_hwecc;
> +                       fallthrough;
>
> -               if (mtd->writesize >= ecc->size) {
> -                       if (!ecc->strength) {
> -                               WARN(1, "Driver must set ecc.strength when using hardware ECC\n");
> +               case NAND_ECC_PLACEMENT_INTERLEAVED:
> +                       if ((!ecc->calculate || !ecc->correct || !ecc->hwctl) &&
> +                           (!ecc->read_page ||
> +                            ecc->read_page == nand_read_page_hwecc ||
> +                            !ecc->write_page ||
> +                            ecc->write_page == nand_write_page_hwecc)) {
> +                               WARN(1, "No ECC functions supplied; hardware ECC not possible\n");
>                                 ret = -EINVAL;
>                                 goto err_nand_manuf_cleanup;
>                         }
> +                       /* Use standard syndrome read/write page function? */
> +                       if (!ecc->read_page)
> +                               ecc->read_page = nand_read_page_syndrome;
> +                       if (!ecc->write_page)
> +                               ecc->write_page = nand_write_page_syndrome;
> +                       if (!ecc->read_page_raw)
> +                               ecc->read_page_raw = nand_read_page_raw_syndrome;
> +                       if (!ecc->write_page_raw)
> +                               ecc->write_page_raw = nand_write_page_raw_syndrome;
> +                       if (!ecc->read_oob)
> +                               ecc->read_oob = nand_read_oob_syndrome;
> +                       if (!ecc->write_oob)
> +                               ecc->write_oob = nand_write_oob_syndrome;
> +
> +                       if (mtd->writesize >= ecc->size) {
> +                               if (!ecc->strength) {
> +                                       WARN(1, "Driver must set ecc.strength when using hardware ECC\n");
> +                                       ret = -EINVAL;
> +                                       goto err_nand_manuf_cleanup;
> +                               }
> +                               break;

Hi Miquel, the changes to the nested switch statement make the logic
of this break wrong.

> +                       }
> +                       pr_warn("%d byte HW ECC not possible on %d byte page size, fallback to SW ECC\n",
> +                               ecc->size, mtd->writesize);
> +                       ecc->mode = NAND_ECC_SOFT;
> +                       ecc->algo = NAND_ECC_ALGO_HAMMING;
>                         break;
> +
> +               default:
> +                       pr_warn("Invalid NAND_ECC_PLACEMENT %d\n",
> +                               ecc->placement);
> +                       ret = -EINVAL;
> +                       goto err_nand_manuf_cleanup;
>                 }
> -               pr_warn("%d byte HW ECC not possible on %d byte page size, fallback to SW ECC\n",
> -                       ecc->size, mtd->writesize);
> -               ecc->mode = NAND_ECC_SOFT;
> -               ecc->algo = NAND_ECC_ALGO_HAMMING;
>                 fallthrough;
> +
>         case NAND_ECC_SOFT:
>                 ret = nand_set_ecc_soft_ops(chip);
>                 if (ret) {
> diff --git a/drivers/mtd/nand/raw/r852.c b/drivers/mtd/nand/raw/r852.c
> index f865e3a47b01..f0988cda4479 100644
> --- a/drivers/mtd/nand/raw/r852.c
> +++ b/drivers/mtd/nand/raw/r852.c
> @@ -859,7 +859,8 @@ static int  r852_probe(struct pci_dev *pci_dev, const struct pci_device_id *id)
>         chip->legacy.write_buf = r852_write_buf;
>
>         /* ecc */
> -       chip->ecc.mode = NAND_ECC_HW_SYNDROME;
> +       chip->ecc.mode = NAND_ECC_HW;
> +       chip->ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
>         chip->ecc.size = R852_DMA_LEN;
>         chip->ecc.bytes = SM_OOB_SIZE;
>         chip->ecc.strength = 2;
> diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
> index 10bbfbf4ad7f..cfd75a12f802 100644
> --- a/include/linux/mtd/rawnand.h
> +++ b/include/linux/mtd/rawnand.h
> @@ -304,6 +304,7 @@ static const struct nand_ecc_caps __name = {                        \
>  /**
>   * struct nand_ecc_ctrl - Control structure for ECC
>   * @mode:      ECC mode
> + * @placement: OOB bytes placement
>   * @algo:      ECC algorithm
>   * @steps:     number of ECC steps per page
>   * @size:      data bytes per ECC step
> @@ -331,7 +332,7 @@ static const struct nand_ecc_caps __name = {                        \
>   *                     controller and always return contiguous in-band and
>   *                     out-of-band data even if they're not stored
>   *                     contiguously on the NAND chip (e.g.
> - *                     NAND_ECC_HW_SYNDROME interleaves in-band and
> + *                     NAND_ECC_PLACEMENT_INTERLEAVED interleaves in-band and
>   *                     out-of-band data).
>   * @write_page_raw:    function to write a raw page without ECC. This function
>   *                     should hide the specific layout used by the ECC
> @@ -339,7 +340,7 @@ static const struct nand_ecc_caps __name = {                        \
>   *                     in-band and out-of-band data. ECC controller is
>   *                     responsible for doing the appropriate transformations
>   *                     to adapt to its specific layout (e.g.
> - *                     NAND_ECC_HW_SYNDROME interleaves in-band and
> + *                     NAND_ECC_PLACEMENT_INTERLEAVED interleaves in-band and
>   *                     out-of-band data).
>   * @read_page: function to read a page according to the ECC generator
>   *             requirements; returns maximum number of bitflips corrected in
> @@ -356,6 +357,7 @@ static const struct nand_ecc_caps __name = {                        \
>   */
>  struct nand_ecc_ctrl {
>         enum nand_ecc_mode mode;
> +       enum nand_ecc_placement placement;
>         enum nand_ecc_algo algo;
>         int steps;
>         int size;
> diff --git a/include/linux/platform_data/mtd-davinci.h b/include/linux/platform_data/mtd-davinci.h
> index 03e92c71b3fa..6e2b252a4ce6 100644
> --- a/include/linux/platform_data/mtd-davinci.h
> +++ b/include/linux/platform_data/mtd-davinci.h
> @@ -69,6 +69,7 @@ struct davinci_nand_pdata {           /* platform_data */
>          * using it with large page chips.
>          */
>         enum nand_ecc_mode      ecc_mode;
> +       enum nand_ecc_placement ecc_placement;
>         u8                      ecc_bits;
>
>         /* e.g. NAND_BUSWIDTH_16 */
> --
> 2.20.1
>
>
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/



-- 
Sincerely,

Han XU



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