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| author | Jens Axboe <jens.axboe@oracle.com> | 2007-05-09 09:02:57 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2007-10-16 11:07:10 +0200 |
| commit | 96b418c960af0d5c7185ff5c4af9376eb37ac9d3 (patch) | |
| tree | c909c9d317262cadb37357e0e13d7c2922cfebc0 /include/linux/scatterlist.h | |
| parent | ab83407e9ee35a4972457aa487be6a7a21afd715 (diff) | |
| download | lwn-96b418c960af0d5c7185ff5c4af9376eb37ac9d3.tar.gz lwn-96b418c960af0d5c7185ff5c4af9376eb37ac9d3.zip | |
Add sg helpers for iterating over a scatterlist table
First step to being able to change the scatterlist setup without
having to modify drivers (a lot :-)
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux/scatterlist.h')
| -rw-r--r-- | include/linux/scatterlist.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 4efbd9c445f5..bed5ab4d756a 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -20,4 +20,13 @@ static inline void sg_init_one(struct scatterlist *sg, const void *buf, sg_set_buf(sg, buf, buflen); } +#define sg_next(sg) ((sg) + 1) +#define sg_last(sg, nents) (&(sg[(nents) - 1])) + +/* + * Loop over each sg element, following the pointer to a new list if necessary + */ +#define for_each_sg(sglist, sg, nr, __i) \ + for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg)) + #endif /* _LINUX_SCATTERLIST_H */ |