aha/include/linux/scatterlist.h
Jens Axboe 96b418c960 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>
2007-10-16 11:07:10 +02:00

32 lines
810 B
C

#ifndef _LINUX_SCATTERLIST_H
#define _LINUX_SCATTERLIST_H
#include <asm/scatterlist.h>
#include <linux/mm.h>
#include <linux/string.h>
static inline void sg_set_buf(struct scatterlist *sg, const void *buf,
unsigned int buflen)
{
sg->page = virt_to_page(buf);
sg->offset = offset_in_page(buf);
sg->length = buflen;
}
static inline void sg_init_one(struct scatterlist *sg, const void *buf,
unsigned int buflen)
{
memset(sg, 0, sizeof(*sg));
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 */