Messages in this thread Patch in this message | | | From | Maxim Levitsky <> | Subject | [PATCH 1/2] scatterlist: add sg_nents | Date | Wed, 26 Sep 2012 11:49:00 +0200 |
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Useful helper to know the number of entries in scatterlist.
Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> --- include/linux/scatterlist.h | 1 + lib/scatterlist.c | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+)
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 7b600da..4bd6c06 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -201,6 +201,7 @@ static inline void *sg_virt(struct scatterlist *sg) return page_address(sg_page(sg)) + sg->offset; } +int sg_nents(struct scatterlist *sg); struct scatterlist *sg_next(struct scatterlist *); struct scatterlist *sg_last(struct scatterlist *s, unsigned int); void sg_init_table(struct scatterlist *, unsigned int); diff --git a/lib/scatterlist.c b/lib/scatterlist.c index e76d85c..5cd9cdc 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -39,6 +39,28 @@ struct scatterlist *sg_next(struct scatterlist *sg) EXPORT_SYMBOL(sg_next); /** + * sg_nents - return total count of entries in scatterlist + * @sg: The scatterlist + * + * Description: + * Allows to know how many entries are in sg, taking into acount + * chaining as well + * + **/ +int sg_nents(struct scatterlist *sg) +{ + int nents = 0; + while (sg) { + nents++; + sg = sg_next(sg); + } + + return nents; +} +EXPORT_SYMBOL(sg_nents); + + +/** * sg_last - return the last scatterlist entry in a list * @sgl: First entry in the scatterlist * @nents: Number of entries in the scatterlist -- 1.7.9.5
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