Re: [RFC PATCH v5 4/6] mtd: rawnand: meson: use macro for OOB area

Miquel Raynal
2023-06-01T08:34:59Z

Hi Arseniy,

AVKrasnov@sberdevices.ru wrote on Thu, 1 Jun 2023 09:18:47 +0300:

> This replaces constants and same patterns for OOB handling with special
> macroses.
>
> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
> ---
> drivers/mtd/nand/raw/meson_nand.c | 33 ++++++++++++++++++-------------
> 1 file changed, 19 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> index e42c28be02f3..23a73268421b 100644
> --- a/drivers/mtd/nand/raw/meson_nand.c
> +++ b/drivers/mtd/nand/raw/meson_nand.c
> @@ -108,6 +108,9 @@
>
> #define PER_INFO_BYTE 8
>
> +#define NFC_USER_BYTES 2
> +#define NFC_OOB_PER_ECC(nand) ((nand)->ecc.bytes + NFC_USER_BYTES)

OOB per ECC for me does not make sense.
OOB is the whole area after the data.
What about NFC_OOB_SZ_PER_ECC_STEP ?

> +
> struct meson_nfc_nand_chip {
> struct list_head node;
> struct nand_chip nand;
> @@ -339,7 +342,7 @@ static u8 *meson_nfc_oob_ptr(struct nand_chip *nand, int i)
> struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> int len;
>
> - len = nand->ecc.size * (i + 1) + (nand->ecc.bytes + 2) * i;
> + len = nand->ecc.size * (i + 1) + NFC_OOB_PER_ECC(nand) * i;
>
> return meson_chip->data_buf + len;
> }
> @@ -350,7 +353,7 @@ static u8 *meson_nfc_data_ptr(struct nand_chip *nand, int i)
> int len, temp;
>
> temp = nand->ecc.size + nand->ecc.bytes;
> - len = (temp + 2) * i;
> + len = (temp + NFC_USER_BYTES) * i;
>
> return meson_chip->data_buf + len;
> }
> @@ -364,7 +367,7 @@ static void meson_nfc_get_data_oob(struct nand_chip *nand,
> u8 *dsrc, *osrc;
> u8 *oobtail;
>
> - oob_len = nand->ecc.bytes + 2;
> + oob_len = NFC_OOB_PER_ECC(nand);
> for (i = 0; i < nand->ecc.steps; i++) {
> if (buf) {
> dsrc = meson_nfc_data_ptr(nand, i);
> @@ -393,7 +396,7 @@ static void meson_nfc_set_data_oob(struct nand_chip *nand,
> u8 *dsrc, *osrc;
> u8 *oobtail;
>
> - oob_len = nand->ecc.bytes + 2;
> + oob_len = NFC_OOB_PER_ECC(nand);
> for (i = 0; i < nand->ecc.steps; i++) {
> if (buf) {
> dsrc = meson_nfc_data_ptr(nand, i);
> @@ -452,7 +455,7 @@ static void meson_nfc_set_user_byte(struct nand_chip *nand, u8 *oob_buf)
> __le64 *info;
> int i, count;
>
> - for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (nand->ecc.bytes + 2)) {
> + for (i = 0, count = 0; i < nand->ecc.steps; i++, count += NFC_OOB_PER_ECC(nand)) {
> info = &meson_chip->info_buf[i];
> *info |= oob_buf[count];
> *info |= oob_buf[count + 1] << 8;
> @@ -465,7 +468,7 @@ static void meson_nfc_get_user_byte(struct nand_chip *nand, u8 *oob_buf)
> __le64 *info;
> int i, count;
>
> - for (i = 0, count = 0; i < nand->ecc.steps; i++, count += (nand->ecc.bytes + 2)) {
> + for (i = 0, count = 0; i < nand->ecc.steps; i++, count += NFC_OOB_PER_ECC(nand)) {
> info = &meson_chip->info_buf[i];
> oob_buf[count] = *info;
> oob_buf[count + 1] = *info >> 8;
> @@ -661,7 +664,7 @@ static u32 meson_nfc_oob_free_bytes(struct nand_chip *nand)
> {
> struct mtd_info *mtd = nand_to_mtd(nand);
>
> - return mtd->oobsize - nand->ecc.steps * (nand->ecc.bytes + 2);
> + return mtd->oobsize - nand->ecc.steps * NFC_OOB_PER_ECC(nand);
> }
>
> static int meson_nfc_write_oob(struct nand_chip *nand, int page)
> @@ -712,11 +715,11 @@ static int meson_nfc_read_oob(struct nand_chip *nand, int page)
> /* Read ECC codes and user bytes. */
> for (i = 0; i < nand->ecc.steps; i++) {
> u32 ecc_offs = nand->ecc.size * (i + 1) +
> - (nand->ecc.bytes + 2) * i;
> + NFC_OOB_PER_ECC(nand) * i;
>
> ret = nand_change_read_column_op(nand, ecc_offs,
> - oob_buf + i * (nand->ecc.bytes + 2),
> - (nand->ecc.bytes + 2), false);
> + oob_buf + i * NFC_OOB_PER_ECC(nand),
> + NFC_OOB_PER_ECC(nand), false);
> if (ret)
> return ret;
> }
> @@ -918,12 +921,14 @@ static int meson_nfc_read_page_hwecc(struct nand_chip *nand, u8 *buf,
>
> for (i = 0; i < nand->ecc.steps ; i++) {
> u8 *data = buf + i * ecc->size;
> - u8 *oob = nand->oob_poi + i * (ecc->bytes + 2);
> + u8 *oob = nand->oob_poi + i * NFC_OOB_PER_ECC(nand);
>
> if (correct_bitmap & BIT_ULL(i))
> continue;
> +
> ret = nand_check_erased_ecc_chunk(data, ecc->size,
> - oob, ecc->bytes + 2,
> + oob,
> + NFC_OOB_PER_ECC(nand),
> NULL, 0,
> ecc->strength);
> if (ret < 0) {
> @@ -1073,7 +1078,7 @@ static int meson_ooblayout_ecc(struct mtd_info *mtd, int section,
> if (section >= nand->ecc.steps)
> return -ERANGE;
>
> - oobregion->offset = 2 + (section * (2 + nand->ecc.bytes));
> + oobregion->offset = NFC_USER_BYTES + (section * NFC_OOB_PER_ECC(nand));

No, the first "2" here is for bad block markers, it is not related to
your ECC engine layout I believe.

> oobregion->length = nand->ecc.bytes;
>
> return 0;
> @@ -1091,7 +1096,7 @@ static int meson_ooblayout_free(struct mtd_info *mtd, int section,
> /* Split rest of OOB area (not covered by ECC engine) per each
> * ECC section. This will be OOB data available to user.
> */
> - oobregion->offset = (section + nand->ecc.steps) * (2 + nand->ecc.bytes);
> + oobregion->offset = (section + nand->ecc.steps) * NFC_OOB_PER_ECC(nand);
> oobregion->length = oob_bytes / nand->ecc.steps;
>
> return 0;

Thanks,
Miquèl