Re: [PATCH v3 09/14] mtd: rawnand: prepare the removal of ONFI/JEDEC parameter pages

[Boris Brezillon <boris.brezillon@bootlin.com>]

On Fri,  2 Mar 2018 15:24:17 +0100
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> The NAND chip parameter page is statically allocated within the
> nand_chip structure, which reserves a lot of space. Even not ONFI nor
> JEDEC chips have it embedded. Also, only a few parameters are actually
> read from the parameter page after the detection.
> 
> To prepare to the removal of such huge structure, a small NAND parameter
> structure is allocated statically and contains only very few members
> that are generic to all chips and actually used elsewhere in the code.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  drivers/mtd/nand/raw/nand_base.c | 32 +++++++++++++-------------------
>  include/linux/mtd/rawnand.h      |  6 ++++++
>  2 files changed, 19 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
> index e5bcfbf7c7f6..30364f60dc4d 100644
> --- a/drivers/mtd/nand/raw/nand_base.c
> +++ b/drivers/mtd/nand/raw/nand_base.c
> @@ -1174,9 +1174,7 @@ int nand_get_features(struct nand_chip *chip, int addr,
>  {
>  	struct mtd_info *mtd = nand_to_mtd(chip);
>  
> -	if (!chip->onfi_version ||
> -	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
> -	      & ONFI_OPT_CMD_SET_GET_FEATURES))
> +	if (!chip->parameters.supports_set_get_features)
>  		return -ENOTSUPP;
>  
>  	return chip->get_features(mtd, chip, addr, subfeature_param);
> @@ -1197,9 +1195,7 @@ int nand_set_features(struct nand_chip *chip, int addr,
>  {
>  	struct mtd_info *mtd = nand_to_mtd(chip);
>  
> -	if (!chip->onfi_version ||
> -	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
> -	      & ONFI_OPT_CMD_SET_GET_FEATURES))
> +	if (!chip->parameters.supports_set_get_features)
>  		return -ENOTSUPP;
>  
>  	return chip->set_features(mtd, chip, addr, subfeature_param);
> @@ -5150,8 +5146,9 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
>  
>  	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
>  	sanitize_string(p->model, sizeof(p->model));
> +	memcpy(chip->parameters.model, p->model, sizeof(p->model));
>  	if (!mtd->name)
> -		mtd->name = p->model;
> +		mtd->name = chip->parameters.model;
>  
>  	mtd->writesize = le32_to_cpu(p->byte_per_page);
>  
> @@ -5198,6 +5195,10 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
>  		pr_warn("Could not retrieve ONFI ECC requirements\n");
>  	}
>  
> +	/* Save some parameters from the parameter page for future use */
> +	if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_SET_GET_FEATURES)
> +		chip->parameters.supports_set_get_features = true;
> +
>  	return 1;
>  }
>  
> @@ -5250,8 +5251,9 @@ static int nand_flash_detect_jedec(struct nand_chip *chip)
>  
>  	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
>  	sanitize_string(p->model, sizeof(p->model));
> +	memcpy(chip->parameters.model, p->model, sizeof(p->model));

It's safe as long as chip->parameters.model is bigger than p->model,
which is the case here, but how about enforcing it, just in case
someone decides to change the chip->parameters.model size.

	strncpy(chip->parameters.model, p->model,
		sizeof(chip->parameters.model) - 1;

>  	if (!mtd->name)
> -		mtd->name = p->model;
> +		mtd->name = chip->parameters.model;
>  
>  	mtd->writesize = le32_to_cpu(p->byte_per_page);
>  
> @@ -5652,17 +5654,9 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type)
>  
>  	pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
>  		maf_id, dev_id);
> -
> -	if (chip->onfi_version)
> -		pr_info("%s %s\n", nand_manufacturer_name(manufacturer),
> -			chip->onfi_params.model);
> -	else if (chip->jedec_version)
> -		pr_info("%s %s\n", nand_manufacturer_name(manufacturer),
> -			chip->jedec_params.model);
> -	else
> -		pr_info("%s %s\n", nand_manufacturer_name(manufacturer),
> -			type->name);
> -
> +	pr_info("%s %s\n", nand_manufacturer_name(manufacturer),
> +		(chip->onfi_version || chip->jedec_version) ?
> +		chip->parameters.model : type->name);
>  	pr_info("%d MiB, %s, erase size: %d KiB, page size: %d, OOB size: %d\n",
>  		(int)(chip->chipsize >> 20), nand_is_slc(chip) ? "SLC" : "MLC",
>  		mtd->erasesize >> 10, mtd->writesize, mtd->oobsize);
> diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
> index 3cc2a3435b20..1af0bff58ff4 100644
> --- a/include/linux/mtd/rawnand.h
> +++ b/include/linux/mtd/rawnand.h
> @@ -429,6 +429,11 @@ struct nand_jedec_params {
>  	__le16 crc;
>  } __packed;
>  
> +struct nand_parameters {
> +	char model[100];
> +	bool supports_set_get_features;
> +};

Can you document this structure with a kernel-doc header?

> +
>  /* The maximum expected count of bytes in the NAND ID sequence */
>  #define NAND_MAX_ID_LEN 8
>  
> @@ -1249,6 +1254,7 @@ struct nand_chip {
>  		struct nand_onfi_params	onfi_params;
>  		struct nand_jedec_params jedec_params;
>  	};
> +	struct nand_parameters parameters;

You forgot to update the kernel-doc header.

>  	u16 max_bb_per_die;
>  	u32 blocks_per_die;
>  



-- 
Boris Brezillon, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com