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

[Miquel Raynal]

Hi Arseniy,

AVKrasnov@xxxxxxxxxxxxxx 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@xxxxxxxxxxxxxx>
> ---
>  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