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SG: Change sg_set_page() to take length and offset argument

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Most drivers need to set length and offset as well, so may as well fold
those three lines into one.

Add sg_assign_page() for those two locations that only needed to set
the page, where the offset/length is set outside of the function context.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe
2007-10-24 11:20:47 +02:00
parent bd6dee6f30
commit 642f149031
31 changed files with 99 additions and 162 deletions
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40
include/linux/scatterlist.h
View File

@ -26,18 +26,16 @@
#define SG_MAGIC 0x87654321
/**
* sg_set_page - Set sg entry to point at given page
* @sg: SG entry
* @page: The page
* sg_assign_page - Assign a given page to an SG entry
* @sg: SG entry
* @page: The page
*
* Description:
* Use this function to set an sg entry pointing at a page, never assign
* the page directly. We encode sg table information in the lower bits
* of the page pointer. See sg_page() for looking up the page belonging
* to an sg entry.
* Assign page to sg entry. Also see sg_set_page(), the most commonly used
* variant.
*
**/
static inline void sg_set_page(struct scatterlist *sg, struct page *page)
static inline void sg_assign_page(struct scatterlist *sg, struct page *page)
{
unsigned long page_link = sg->page_link & 0x3;
@ -52,6 +50,28 @@ static inline void sg_set_page(struct scatterlist *sg, struct page *page)
sg->page_link = page_link | (unsigned long) page;
}
/**
* sg_set_page - Set sg entry to point at given page
* @sg: SG entry
* @page: The page
* @len: Length of data
* @offset: Offset into page
*
* Description:
* Use this function to set an sg entry pointing at a page, never assign
* the page directly. We encode sg table information in the lower bits
* of the page pointer. See sg_page() for looking up the page belonging
* to an sg entry.
*
**/
static inline void sg_set_page(struct scatterlist *sg, struct page *page,
unsigned int len, unsigned int offset)
{
sg_assign_page(sg, page);
sg->offset = offset;
sg->length = len;
}
#define sg_page(sg) ((struct page *) ((sg)->page_link & ~0x3))
/**
@ -64,9 +84,7 @@ static inline void sg_set_page(struct scatterlist *sg, struct page *page)
static inline void sg_set_buf(struct scatterlist *sg, const void *buf,
unsigned int buflen)
{
sg_set_page(sg, virt_to_page(buf));
sg->offset = offset_in_page(buf);
sg->length = buflen;
sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
}
/*