1 /* SPDX-License-Identifier: GPL-2.0 */
8 	unsigned int	offset;  member
14 #define sg_is_chain(sg)		((sg)->page_link & 0x01)
15 #define sg_is_last(sg)		((sg)->page_link & 0x02)
17 	((struct scatterlist *) ((sg)->page_link & ~0x03))
20  * sg_assign_page - Assign a given page to an SG entry
22  * @page:	    The page
25  *   Assign page to sg entry. Also see sg_set_page(), the most commonly used
29 static inline void sg_assign_page(struct scatterlist *sg, struct page *page)  in sg_assign_page()  argument
31 	unsigned long page_link = sg->page_link & 0x3;  in sg_assign_page()
35 	 * must be aligned at a 32-bit boundary as a minimum.  in sg_assign_page()
37 	BUG_ON((unsigned long) page & 0x03);  in sg_assign_page()
41 	sg->page_link = page_link | (unsigned long) page;  in sg_assign_page()
45  * sg_set_page - Set sg entry to point at given page
47  * @page:	 The page
49  * @offset:	 Offset into page
52  *   Use this function to set an sg entry pointing at a page, never assign
53  *   the page directly. We encode sg table information in the lower bits
54  *   of the page pointer. See sg_page() for looking up the page belonging
58 static inline void sg_set_page(struct scatterlist *sg, struct page *page,  in sg_set_page()  argument
59 			       unsigned int len, unsigned int offset)  in sg_set_page()  argument
61 	sg_assign_page(sg, page);  in sg_set_page()
62 	sg->offset = offset;  in sg_set_page()
63 	sg->length = len;  in sg_set_page()
66 static inline struct page *sg_page(struct scatterlist *sg)  in sg_page()
71 	return (struct page *)((sg)->page_link & ~0x3);  in sg_page()
81  * sg_chain - Chain two sglists together
94 	 * offset and length are unused for chain entry.  Clear them.  in sg_chain()
96 	prv[prv_nents - 1].offset = 0;  in sg_chain()
97 	prv[prv_nents - 1].length = 0;  in sg_chain()
103 	prv[prv_nents - 1].page_link = ((unsigned long) sgl | 0x01) & ~0x02;  in sg_chain()
107  * sg_mark_end - Mark the end of the scatterlist
120 	sg->page_link |= 0x02;  in sg_mark_end()
121 	sg->page_link &= ~0x01;  in sg_mark_end()
125  * sg_unmark_end - Undo setting the end of the scatterlist
134 	sg->page_link &= ~0x02;  in sg_unmark_end()
152 	sg_mark_end(&sgl[nents - 1]);  in sg_init_table()
157 	return page_to_phys(sg_page(sg)) + sg->offset;  in sg_phys()