1 /* SPDX-License-Identifier: GPL-2.0 */
9 	unsigned int	offset;  member
15 #define sg_is_chain(sg)		((sg)->page_link & 0x01)
16 #define sg_is_last(sg)		((sg)->page_link & 0x02)
18 	((struct scatterlist *) ((sg)->page_link & ~0x03))
21  * sg_assign_page - Assign a given page to an SG entry
23  * @page:	    The page
26  *   Assign page to sg entry. Also see sg_set_page(), the most commonly used
30 static inline void sg_assign_page(struct scatterlist *sg, struct page *page)  in sg_assign_page()  argument
32 	unsigned long page_link = sg->page_link & 0x3;  in sg_assign_page()
36 	 * must be aligned at a 32-bit boundary as a minimum.  in sg_assign_page()
38 	BUG_ON((unsigned long) page & 0x03);  in sg_assign_page()
42 	sg->page_link = page_link | (unsigned long) page;  in sg_assign_page()
46  * sg_set_page - Set sg entry to point at given page
48  * @page:	 The page
50  * @offset:	 Offset into page
53  *   Use this function to set an sg entry pointing at a page, never assign
54  *   the page directly. We encode sg table information in the lower bits
55  *   of the page pointer. See sg_page() for looking up the page belonging
59 static inline void sg_set_page(struct scatterlist *sg, struct page *page,  in sg_set_page()  argument
60 			       unsigned int len, unsigned int offset)  in sg_set_page()  argument
62 	sg_assign_page(sg, page);  in sg_set_page()
63 	sg->offset = offset;  in sg_set_page()
64 	sg->length = len;  in sg_set_page()
67 static inline struct page *sg_page(struct scatterlist *sg)  in sg_page()
72 	return (struct page *)((sg)->page_link & ~0x3);  in sg_page()
82  * sg_chain - Chain two sglists together
95 	 * offset and length are unused for chain entry.  Clear them.  in sg_chain()
97 	prv[prv_nents - 1].offset = 0;  in sg_chain()
98 	prv[prv_nents - 1].length = 0;  in sg_chain()
104 	prv[prv_nents - 1].page_link = ((unsigned long) sgl | 0x01) & ~0x02;  in sg_chain()
108  * sg_mark_end - Mark the end of the scatterlist
121 	sg->page_link |= 0x02;  in sg_mark_end()
122 	sg->page_link &= ~0x01;  in sg_mark_end()
126  * sg_unmark_end - Undo setting the end of the scatterlist
135 	sg->page_link &= ~0x02;  in sg_unmark_end()
153 	sg_mark_end(&sgl[nents - 1]);  in sg_init_table()
158 	return page_to_phys(sg_page(sg)) + sg->offset;  in sg_phys()