[PATCH 01/14] mtd: nand: brcm: switch to mtd_ooblayout_ops

William Zhang william.zhang at broadcom.com
Thu Jan 26 02:02:26 CET 2023


Hi Linus,

Unfortunately the u-boot nand base code still uses nand_ecclayout 
structure because it was based on old kernel nand driver.  Your change 
cause bugcheck in the nand_scan_tail at line 4978 when mtd->oobsize is 
not one of the default size (i.e. some large nand with BCH-8 ecc 
requirement and has 224 bytes oobsize per 4K page) because ecc->layout 
is never set. Also certainly any data built based on nand_cclayout like 
mtd->oobavail will not be correct.

I actually converted back to nand_ecclayout structure from mtd_ooblayout 
with this fix to solve the above issues.
Fixes: e365de90517b ("drivers: nand: brcmnand: fix nand_chip ecc layout 
structure")

I can see your point to get the latest from the brcmnand linux kernel 
driver but this requires updating the u-boot nand base driver to use 
mtd_ooblayout as well and all others nand controller drivers too. I am 
not sure if this is something you want to tackle right now.

As far as I can see, all other oob/ecc layout setting patches you back 
ported in this series are not in the original brcmstb_choose_ecc_layout 
code you replaced. So I am not worried about that we must switch to 
mtd_ooblayout_ops at this point.  If indeed there is bug in 
brcmstb_choose_ecc_layout, we can port and convert the fix to 
nand_ecclayout structure from kernel code.

Was the bug you were hunting down in the code related to this patch?

Thanks,
William


On 01/15/2023 11:52 AM, Linus Walleij wrote:
> From: Boris Brezillon <boris.brezillon at free-electrons.com>
> 
> Implementing the mtd_ooblayout_ops interface is the new way of exposing
> ECC/OOB layout to MTD users.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> [Ported to U-Boot from the Linux kernel]
> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> ---
>   drivers/mtd/nand/raw/brcmnand/brcmnand.c | 260 ++++++++++++++---------
>   1 file changed, 156 insertions(+), 104 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> index 74c9348f7fc4..8ea33e861354 100644
> --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> @@ -894,131 +894,183 @@ static inline bool is_hamming_ecc(struct brcmnand_controller *ctrl,
>   }
>   
>   /*
> - * Returns a nand_ecclayout strucutre for the given layout/configuration.
> - * Returns NULL on failure.
> + * Set mtd->ooblayout to the appropriate mtd_ooblayout_ops given
> + * the layout/configuration.
> + * Returns -ERRCODE on failure.
>    */
> -static struct nand_ecclayout *brcmnand_create_layout(int ecc_level,
> -						     struct brcmnand_host *host)
> +static int brcmnand_hamming_ooblayout_ecc(struct mtd_info *mtd, int section,
> +					  struct mtd_oob_region *oobregion)
>   {
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct brcmnand_host *host = nand_get_controller_data(chip);
>   	struct brcmnand_cfg *cfg = &host->hwcfg;
> -	int i, j;
> -	struct nand_ecclayout *layout;
> -	int req;
> -	int sectors;
> -	int sas;
> -	int idx1, idx2;
>   
> -#ifndef __UBOOT__
> -	layout = devm_kzalloc(&host->pdev->dev, sizeof(*layout), GFP_KERNEL);
> -#else
> -	layout = devm_kzalloc(host->pdev, sizeof(*layout), GFP_KERNEL);
> -#endif
> -	if (!layout)
> -		return NULL;
> -
> -	sectors = cfg->page_size / (512 << cfg->sector_size_1k);
> -	sas = cfg->spare_area_size << cfg->sector_size_1k;
> -
> -	/* Hamming */
> -	if (is_hamming_ecc(host->ctrl, cfg)) {
> -		for (i = 0, idx1 = 0, idx2 = 0; i < sectors; i++) {
> -			/* First sector of each page may have BBI */
> -			if (i == 0) {
> -				layout->oobfree[idx2].offset = i * sas + 1;
> -				/* Small-page NAND use byte 6 for BBI */
> -				if (cfg->page_size == 512)
> -					layout->oobfree[idx2].offset--;
> -				layout->oobfree[idx2].length = 5;
> -			} else {
> -				layout->oobfree[idx2].offset = i * sas;
> -				layout->oobfree[idx2].length = 6;
> -			}
> -			idx2++;
> -			layout->eccpos[idx1++] = i * sas + 6;
> -			layout->eccpos[idx1++] = i * sas + 7;
> -			layout->eccpos[idx1++] = i * sas + 8;
> -			layout->oobfree[idx2].offset = i * sas + 9;
> -			layout->oobfree[idx2].length = 7;
> -			idx2++;
> -			/* Leave zero-terminated entry for OOBFREE */
> -			if (idx1 >= MTD_MAX_ECCPOS_ENTRIES_LARGE ||
> -			    idx2 >= MTD_MAX_OOBFREE_ENTRIES_LARGE - 1)
> -				break;
> -		}
> +	int sas = cfg->spare_area_size << cfg->sector_size_1k;
> +	int sectors = cfg->page_size / (512 << cfg->sector_size_1k);
>   
> -		return layout;
> -	}
> +	if (section >= sectors)
> +		return -ERANGE;
> +	oobregion->offset = (section * sas) + 6;
> +	oobregion->length = 3;
>   
> -	/*
> -	 * CONTROLLER_VERSION:
> -	 *   < v5.0: ECC_REQ = ceil(BCH_T * 13/8)
> -	 *  >= v5.0: ECC_REQ = ceil(BCH_T * 14/8)
> -	 * But we will just be conservative.
> -	 */
> -	req = DIV_ROUND_UP(ecc_level * 14, 8);
> -	if (req >= sas) {
> -		dev_err(host->pdev,
> -			"error: ECC too large for OOB (ECC bytes %d, spare sector %d)\n",
> -			req, sas);
> -		return NULL;
> -	}
> +	return 0;
> +}
> +
> +static int brcmnand_hamming_ooblayout_free(struct mtd_info *mtd, int section,
> +					   struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct brcmnand_host *host = nand_get_controller_data(chip);
> +	struct brcmnand_cfg *cfg = &host->hwcfg;
> +	int sas = cfg->spare_area_size << cfg->sector_size_1k;
> +	int sectors = cfg->page_size / (512 << cfg->sector_size_1k);
> +
> +	if (section >= sectors * 2)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section / 2) * sas;
>   
> -	layout->eccbytes = req * sectors;
> -	for (i = 0, idx1 = 0, idx2 = 0; i < sectors; i++) {
> -		for (j = sas - req; j < sas && idx1 <
> -				MTD_MAX_ECCPOS_ENTRIES_LARGE; j++, idx1++)
> -			layout->eccpos[idx1] = i * sas + j;
> +	if (section & 1) {
> +		oobregion->offset += 9;
> +		oobregion->length = 7;
> +	} else {
> +		oobregion->length = 6;
>   
>   		/* First sector of each page may have BBI */
> -		if (i == 0) {
> -			if (cfg->page_size == 512 && (sas - req >= 6)) {
> -				/* Small-page NAND use byte 6 for BBI */
> -				layout->oobfree[idx2].offset = 0;
> -				layout->oobfree[idx2].length = 5;
> -				idx2++;
> -				if (sas - req > 6) {
> -					layout->oobfree[idx2].offset = 6;
> -					layout->oobfree[idx2].length =
> -						sas - req - 6;
> -					idx2++;
> -				}
> -			} else if (sas > req + 1) {
> -				layout->oobfree[idx2].offset = i * sas + 1;
> -				layout->oobfree[idx2].length = sas - req - 1;
> -				idx2++;
> -			}
> -		} else if (sas > req) {
> -			layout->oobfree[idx2].offset = i * sas;
> -			layout->oobfree[idx2].length = sas - req;
> -			idx2++;
> +		if (!section) {
> +			/*
> +			 * Small-page NAND use byte 6 for BBI while large-page
> +			 * NAND use byte 0.
> +			 */
> +			if (cfg->page_size > 512)
> +				oobregion->offset++;
> +			oobregion->length--;
>   		}
> -		/* Leave zero-terminated entry for OOBFREE */
> -		if (idx1 >= MTD_MAX_ECCPOS_ENTRIES_LARGE ||
> -		    idx2 >= MTD_MAX_OOBFREE_ENTRIES_LARGE - 1)
> -			break;
>   	}
>   
> -	return layout;
> +	return 0;
>   }
>   
> -static struct nand_ecclayout *brcmstb_choose_ecc_layout(
> -		struct brcmnand_host *host)
> +static const struct mtd_ooblayout_ops brcmnand_hamming_ooblayout_ops = {
> +	.ecc = brcmnand_hamming_ooblayout_ecc,
> +	.rfree = brcmnand_hamming_ooblayout_free,
> +};
> +
> +static int brcmnand_bch_ooblayout_ecc(struct mtd_info *mtd, int section,
> +				      struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct brcmnand_host *host = nand_get_controller_data(chip);
> +	struct brcmnand_cfg *cfg = &host->hwcfg;
> +	int sas = cfg->spare_area_size << cfg->sector_size_1k;
> +	int sectors = cfg->page_size / (512 << cfg->sector_size_1k);
> +
> +	if (section >= sectors)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section * (sas + 1)) - chip->ecc.bytes;
> +	oobregion->length = chip->ecc.bytes;
> +
> +	return 0;
> +}
> +
> +static int brcmnand_bch_ooblayout_free_lp(struct mtd_info *mtd, int section,
> +					  struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct brcmnand_host *host = nand_get_controller_data(chip);
> +	struct brcmnand_cfg *cfg = &host->hwcfg;
> +	int sas = cfg->spare_area_size << cfg->sector_size_1k;
> +	int sectors = cfg->page_size / (512 << cfg->sector_size_1k);
> +
> +	if (section >= sectors)
> +		return -ERANGE;
> +
> +	if (sas <= chip->ecc.bytes)
> +		return 0;
> +
> +	oobregion->offset = section * sas;
> +	oobregion->length = sas - chip->ecc.bytes;
> +
> +	if (!section) {
> +		oobregion->offset++;
> +		oobregion->length--;
> +	}
> +
> +	return 0;
> +}
> +
> +static int brcmnand_bch_ooblayout_free_sp(struct mtd_info *mtd, int section,
> +					  struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct brcmnand_host *host = nand_get_controller_data(chip);
> +	struct brcmnand_cfg *cfg = &host->hwcfg;
> +	int sas = cfg->spare_area_size << cfg->sector_size_1k;
> +
> +	if (section > 1 || sas - chip->ecc.bytes < 6 ||
> +	    (section && sas - chip->ecc.bytes == 6))
> +		return -ERANGE;
> +
> +	if (!section) {
> +		oobregion->offset = 0;
> +		oobregion->length = 5;
> +	} else {
> +		oobregion->offset = 6;
> +		oobregion->length = sas - chip->ecc.bytes - 6;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct mtd_ooblayout_ops brcmnand_bch_lp_ooblayout_ops = {
> +	.ecc = brcmnand_bch_ooblayout_ecc,
> +	.rfree = brcmnand_bch_ooblayout_free_lp,
> +};
> +
> +static const struct mtd_ooblayout_ops brcmnand_bch_sp_ooblayout_ops = {
> +	.ecc = brcmnand_bch_ooblayout_ecc,
> +	.rfree = brcmnand_bch_ooblayout_free_sp,
> +};
> +
> +static int brcmstb_choose_ecc_layout(struct brcmnand_host *host)
>   {
> -	struct nand_ecclayout *layout;
>   	struct brcmnand_cfg *p = &host->hwcfg;
> +	struct mtd_info *mtd = nand_to_mtd(&host->chip);
> +	struct nand_ecc_ctrl *ecc = &host->chip.ecc;
>   	unsigned int ecc_level = p->ecc_level;
> +	int sas = p->spare_area_size << p->sector_size_1k;
> +	int sectors = p->page_size / (512 << p->sector_size_1k);
>   
>   	if (p->sector_size_1k)
>   		ecc_level <<= 1;
>   
> -	layout = brcmnand_create_layout(ecc_level, host);
> -	if (!layout) {
> +	if (is_hamming_ecc(host->ctrl, p)) {
> +		ecc->bytes = 3 * sectors;
> +		mtd_set_ooblayout(mtd, &brcmnand_hamming_ooblayout_ops);
> +		return 0;
> +	}
> +
> +	/*
> +	 * CONTROLLER_VERSION:
> +	 *   < v5.0: ECC_REQ = ceil(BCH_T * 13/8)
> +	 *  >= v5.0: ECC_REQ = ceil(BCH_T * 14/8)
> +	 * But we will just be conservative.
> +	 */
> +	ecc->bytes = DIV_ROUND_UP(ecc_level * 14, 8);
> +	if (p->page_size == 512)
> +		mtd_set_ooblayout(mtd, &brcmnand_bch_sp_ooblayout_ops);
> +	else
> +		mtd_set_ooblayout(mtd, &brcmnand_bch_lp_ooblayout_ops);
> +
> +	if (ecc->bytes >= sas) {
>   		dev_err(host->pdev,
> -			"no proper ecc_layout for this NAND cfg\n");
> -		return NULL;
> +			"error: ECC too large for OOB (ECC bytes %d, spare sector %d)\n",
> +			ecc->bytes, sas);
> +		return -EINVAL;
>   	}
>   
> -	return layout;
> +	return 0;
>   }
>   
>   static void brcmnand_wp(struct mtd_info *mtd, int wp)
> @@ -2329,9 +2381,9 @@ static int brcmnand_init_cs(struct brcmnand_host *host, ofnode dn)
>   	/* only use our internal HW threshold */
>   	mtd->bitflip_threshold = 1;
>   
> -	chip->ecc.layout = brcmstb_choose_ecc_layout(host);
> -	if (!chip->ecc.layout)
> -		return -ENXIO;
> +	ret = brcmstb_choose_ecc_layout(host);
> +	if (ret)
> +		return ret;
>   
>   	ret = nand_scan_tail(mtd);
>   	if (ret)
> 
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