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-rw-r--r--include/linux/scatterlist.h43
1 files changed, 31 insertions, 12 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index df7ddcee7c4..45712317138 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -1,6 +1,7 @@
1#ifndef _LINUX_SCATTERLIST_H 1#ifndef _LINUX_SCATTERLIST_H
2#define _LINUX_SCATTERLIST_H 2#define _LINUX_SCATTERLIST_H
3 3
4#include <asm/types.h>
4#include <asm/scatterlist.h> 5#include <asm/scatterlist.h>
5#include <linux/mm.h> 6#include <linux/mm.h>
6#include <linux/string.h> 7#include <linux/string.h>
@@ -26,18 +27,16 @@
26#define SG_MAGIC 0x87654321 27#define SG_MAGIC 0x87654321
27 28
28/** 29/**
29 * sg_set_page - Set sg entry to point at given page 30 * sg_assign_page - Assign a given page to an SG entry
30 * @sg: SG entry 31 * @sg: SG entry
31 * @page: The page 32 * @page: The page
32 * 33 *
33 * Description: 34 * Description:
34 * Use this function to set an sg entry pointing at a page, never assign 35 * Assign page to sg entry. Also see sg_set_page(), the most commonly used
35 * the page directly. We encode sg table information in the lower bits 36 * variant.
36 * of the page pointer. See sg_page() for looking up the page belonging
37 * to an sg entry.
38 * 37 *
39 **/ 38 **/
40static inline void sg_set_page(struct scatterlist *sg, struct page *page) 39static inline void sg_assign_page(struct scatterlist *sg, struct page *page)
41{ 40{
42 unsigned long page_link = sg->page_link & 0x3; 41 unsigned long page_link = sg->page_link & 0x3;
43 42
@@ -52,6 +51,28 @@ static inline void sg_set_page(struct scatterlist *sg, struct page *page)
52 sg->page_link = page_link | (unsigned long) page; 51 sg->page_link = page_link | (unsigned long) page;
53} 52}
54 53
54/**
55 * sg_set_page - Set sg entry to point at given page
56 * @sg: SG entry
57 * @page: The page
58 * @len: Length of data
59 * @offset: Offset into page
60 *
61 * Description:
62 * Use this function to set an sg entry pointing at a page, never assign
63 * the page directly. We encode sg table information in the lower bits
64 * of the page pointer. See sg_page() for looking up the page belonging
65 * to an sg entry.
66 *
67 **/
68static inline void sg_set_page(struct scatterlist *sg, struct page *page,
69 unsigned int len, unsigned int offset)
70{
71 sg_assign_page(sg, page);
72 sg->offset = offset;
73 sg->length = len;
74}
75
55#define sg_page(sg) ((struct page *) ((sg)->page_link & ~0x3)) 76#define sg_page(sg) ((struct page *) ((sg)->page_link & ~0x3))
56 77
57/** 78/**
@@ -64,9 +85,7 @@ static inline void sg_set_page(struct scatterlist *sg, struct page *page)
64static inline void sg_set_buf(struct scatterlist *sg, const void *buf, 85static inline void sg_set_buf(struct scatterlist *sg, const void *buf,
65 unsigned int buflen) 86 unsigned int buflen)
66{ 87{
67 sg_set_page(sg, virt_to_page(buf)); 88 sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
68 sg->offset = offset_in_page(buf);
69 sg->length = buflen;
70} 89}
71 90
72/* 91/*
@@ -237,7 +256,7 @@ static inline void sg_init_table(struct scatterlist *sgl, unsigned int nents)
237 * on the sg page. 256 * on the sg page.
238 * 257 *
239 **/ 258 **/
240static inline unsigned long sg_phys(struct scatterlist *sg) 259static inline dma_addr_t sg_phys(struct scatterlist *sg)
241{ 260{
242 return page_to_phys(sg_page(sg)) + sg->offset; 261 return page_to_phys(sg_page(sg)) + sg->offset;
243} 262}