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>
This commit is contained in:
Jens Axboe 2007-05-09 09:02:57 +02:00
parent ab83407e9e
commit 96b418c960
1 changed files with 9 additions and 0 deletions

View File

@ -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 */