Re: [PATCH v3 2/8] mtd: nand: add oob iterator in nand_for_each_page

[Boris Brezillon <boris.brezillon@free-electrons.com>]

On Thu, 16 Mar 2017 14:47:31 +0800
Peter Pan <peterpandong@micron.com> wrote:

> Iterate nand pages by both page and oob operation.
> 
> Signed-off-by: Peter Pan <peterpandong@micron.com>
> ---
>  include/linux/mtd/nand.h | 28 +++++++++++++++++++++++++---
>  1 file changed, 25 insertions(+), 3 deletions(-)
> 
> diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
> index 4a812e6..822547e 100644
> --- a/include/linux/mtd/nand.h
> +++ b/include/linux/mtd/nand.h
> @@ -87,6 +87,9 @@ struct nand_page_iter {
>  	loff_t offs;
>  	int page;
>  	int pageoffs;
> +	int ooboffs;
> +	int oobsize;
> +	size_t oobleft;

Maybe we should also add dataleft so that you don't have to pass start
and len when you call nand_page_iter_end().

>  };
>  
>  /**
> @@ -194,6 +197,7 @@ static inline int nand_per_page_oobsize(struct nand_device *nand)
>   * @iter: page iterator
>   */
>  static inline void nand_page_iter_init(struct nand_device *nand, loff_t offs,
> +				       u32 ooboffs, size_t ooblen, u32 oobsize,
>  				       struct nand_page_iter *iter)
>  {
>  	u64 page = offs;
> @@ -201,6 +205,9 @@ static inline void nand_page_iter_init(struct nand_device *nand, loff_t offs,
>  	iter->pageoffs = do_div(page, nand->memorg.pagesize);
>  	iter->page = page;
>  	iter->offs = offs;
> +	iter->ooboffs = ooboffs;
> +	iter->oobsize = oobsize;
> +	iter->oobleft = ooblen;
>  }
>  
>  /**
> @@ -214,11 +221,26 @@ static inline void nand_page_iter_next(struct nand_device *nand,
>  	iter->page++;
>  	iter->offs += nand_page_size(nand) - iter->pageoffs;
>  	iter->pageoffs = 0;
> +	if (iter->oobleft)
> +		iter->oobleft -= min_t(int, iter->oobsize - iter->ooboffs,
> +				       iter->oobleft);
> +}
> +
> +static inline bool nand_page_iter_end(struct nand_device *nand, loff_t offs,
> +				      u32 len, struct nand_page_iter *iter)
> +{
> +	if (iter->offs < offs + len)
> +		return false;
> +	if (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)	\
> +	for (nand_page_iter_init(nand, start, ooboffs,		\
> +				 ooblen, oobsize, iter);	\
> +	     !nand_page_iter_end(nand, start, len, iter);		\
>  	     nand_page_iter_next(nand, iter))
>  
>  /**