[PATCH v4 1/9] mtd: nand: add oob iterator in nand_for_each_page

[Marek Vasut]

On 03/23/2017 10:43 AM, Peter Pan wrote:
> Iterate nand pages by both page and oob operation.
> 
> Signed-off-by: Peter Pan <peterpandong at micron.com>
> ---
>  include/linux/mtd/nand.h | 38 +++++++++++++++++++++++++++++++-------
>  1 file changed, 31 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
> index c2197b4..54ded4c 100644
> --- a/include/linux/mtd/nand.h
> +++ b/include/linux/mtd/nand.h
> @@ -84,9 +84,12 @@ struct nand_device {
>   * @pageoffset: the offset within a page
>   */
>  struct nand_page_iter {
> -	loff_t offs;
>  	int page;
>  	int pageoffs;
> +	size_t dataleft;
> +	int ooboffs;
> +	int oobsize;
> +	size_t oobleft;
>  };
>  
>  /**
> @@ -193,14 +196,19 @@ static inline int nand_per_page_oobsize(struct nand_device *nand)
>   * @offs: absolute offset
>   * @iter: page iterator
>   */
> -static inline void nand_page_iter_init(struct nand_device *nand, loff_t offs,
> +static inline void nand_page_iter_init(struct nand_device *nand,
> +				       loff_t offs, size_t len, u32 ooboffs,
> +				       size_t ooblen, u32 oobsize,
>  				       struct nand_page_iter *iter)
>  {
>  	u64 page = offs;
>  
>  	iter->pageoffs = do_div(page, nand->memorg.pagesize);
>  	iter->page = page;
> -	iter->offs = offs;
> +	iter->dataleft = len;
> +	iter->ooboffs = ooboffs;
> +	iter->oobsize = oobsize;
> +	iter->oobleft = ooblen;
>  }
>  
>  /**
> @@ -212,13 +220,29 @@ static inline void nand_page_iter_next(struct nand_device *nand,
>  				       struct nand_page_iter *iter)
>  {
>  	iter->page++;
> -	iter->offs += nand_page_size(nand) - iter->pageoffs;
>  	iter->pageoffs = 0;
> +	if (iter->dataleft)
> +		iter->dataleft -= min_t (int,
                                         ^^^
                                         shouldn't this be size_t ?

> +					 nand_page_size(nand) - iter->pageoffs,
> +					 iter->dataleft);
> +	if (iter->oobleft)
> +		iter->oobleft -= min_t(int, iter->oobsize - iter->ooboffs,

DTTO here ?

> +				       iter->oobleft);
> +}
> +
> +static inline bool nand_page_iter_end(struct nand_device *nand,
> +				      struct nand_page_iter *iter)
> +{
> +	if (iter->dataleft || iter->oobleft)
> +		return false;
> +	return true;
>  }
>  
> -#define nand_for_each_page(nand, start, len, iter)		\
> -	for (nand_page_iter_init(nand, start, iter);		\
> -	     (iter)->offs < (start) + (len);			\
> +#define nand_for_each_page(nand, start, len, ooboffs, ooblen,	\
> +			   oobsize, iter)	\

What's the difference between ooblen and oobsize ? That is totally
confusing , so add a comment explaining that ...

> +	for (nand_page_iter_init(nand, start, len, ooboffs,	\
> +				 ooblen, oobsize, iter);	\
> +	     !nand_page_iter_end(nand, iter);		\
>  	     nand_page_iter_next(nand, iter))
>  
>  /**
> 


-- 
Best regards,
Marek Vasut