17  * @sg:		The current sg entry
20  *   Usually the next entry will be @sg@ + 1, but if this sg element is part
25 struct scatterlist *sg_next(struct scatterlist *sg)  in sg_next()  argument
27 	if (sg_is_last(sg))  in sg_next()
30 	sg++;  in sg_next()
31 	if (unlikely(sg_is_chain(sg)))  in sg_next()
32 		sg = sg_chain_ptr(sg);  in sg_next()
34 	return sg;  in sg_next()
40  * @sg:		The scatterlist
43  * Allows to know how many entries are in sg, taking into account
47 int sg_nents(struct scatterlist *sg)  in sg_nents()  argument
50 	for (nents = 0; sg; sg = sg_next(sg))  in sg_nents()
59  * @sg:		The scatterlist
63  * Determines the number of entries in sg that are required to meet
67  *   the number of sg entries needed, negative error on failure
70 int sg_nents_for_len(struct scatterlist *sg, u64 len)  in sg_nents_for_len()  argument
78 	for (nents = 0, total = 0; sg; sg = sg_next(sg)) {  in sg_nents_for_len()
80 		total += sg->length;  in sg_nents_for_len()
105 	struct scatterlist *sg, *ret = NULL;  in sg_last()  local
108 	for_each_sg(sgl, sg, nents, i)  in sg_last()
109 		ret = sg;  in sg_last()
117  * sg_init_table - Initialize SG table
118  * @sgl:	   The SG table
122  *   If this is part of a chained sg table, sg_mark_end() should be
134  * sg_init_one - Initialize a single entry sg list
135  * @sg:		 SG entry
140 void sg_init_one(struct scatterlist *sg, const void *buf, unsigned int buflen)  in sg_init_one()  argument
142 	sg_init_table(sg, 1);  in sg_init_one()
143 	sg_set_buf(sg, buf, buflen);  in sg_init_one()
171 static void sg_kfree(struct scatterlist *sg, unsigned int nents)  in sg_kfree()  argument
174 		kmemleak_free(sg);  in sg_kfree()
175 		free_page((unsigned long) sg);  in sg_kfree()
177 		kfree(sg);  in sg_kfree()
181  * __sg_free_table - Free a previously mapped sg table
182  * @table:	The sg table header to use
190  *    Free an sg table previously allocated and setup with
212 		 * then assign 'next' to the sg table after the current one.  in __sg_free_table()
239  * sg_free_append_table - Free a previously allocated append sg table.
240  * @table:	 The mapped sg append table header
252  * sg_free_table - Free a previously allocated sg table
253  * @table:	The mapped sg table header
264  * __sg_alloc_table - Allocate and initialize an sg table with given allocator
265  * @table:	The sg table header to use
266  * @nents:	Number of entries in sg list
290 	struct scatterlist *sg, *prv;  in __sg_alloc_table()  local
318 			sg = first_chunk;  in __sg_alloc_table()
321 			sg = alloc_fn(alloc_size, gfp_mask);  in __sg_alloc_table()
323 		if (unlikely(!sg)) {  in __sg_alloc_table()
336 		sg_init_table(sg, alloc_size);  in __sg_alloc_table()
340 		 * If this is the first mapping, assign the sg table header.  in __sg_alloc_table()
344 			sg_chain(prv, prv_max_ents, sg);  in __sg_alloc_table()
346 			table->sgl = sg;  in __sg_alloc_table()
352 			sg_mark_end(&sg[sg_size - 1]);  in __sg_alloc_table()
354 		prv = sg;  in __sg_alloc_table()
364  * sg_alloc_table - Allocate and initialize an sg table
365  * @table:	The sg table header to use
366  * @nents:	Number of entries in sg list
370  *    Allocate and initialize an sg table. If @nents@ is larger than
371  *    SG_MAX_SINGLE_ALLOC a chained sg table will be setup.
426  * sg_alloc_append_table_from_pages - Allocate and initialize an append sg
428  * @sgt_append:  The sg append table to use
438  *    In the first call it allocate and initialize an sg table from a list of
443  *    returned sg table is released by sg_free_append_table
482 		/* Merge contiguous pages into the last SG */  in sg_alloc_append_table_from_pages()
556  * sg_alloc_table_from_pages_segment - Allocate and initialize an sg table from
559  * @sgt:	 The sg table header to use
568  *    Allocate and initialize an sg table from a list of pages. Contiguous
573  *    The returned sg table is released by sg_free_table.
615 	struct scatterlist *sgl, *sg;  in sgl_alloc_order()  local
637 	sg = sgl;  in sgl_alloc_order()
646 		sg_set_page(sg, page, elem_len, 0);  in sgl_alloc_order()
648 		sg = sg_next(sg);  in sgl_alloc_order()
687 	struct scatterlist *sg;  in sgl_free_n_order()  local
691 	for_each_sg(sgl, sg, nents, i) {  in sgl_free_n_order()
692 		if (!sg)  in sgl_free_n_order()
694 		page = sg_page(sg);  in sgl_free_n_order()
732 	piter->sg = sglist;  in __sg_page_iter_start()
737 static int sg_page_count(struct scatterlist *sg)  in sg_page_count()  argument
739 	return PAGE_ALIGN(sg->offset + sg->length) >> PAGE_SHIFT;  in sg_page_count()
744 	if (!piter->__nents || !piter->sg)  in __sg_page_iter_next()
750 	while (piter->sg_pgoffset >= sg_page_count(piter->sg)) {  in __sg_page_iter_next()
751 		piter->sg_pgoffset -= sg_page_count(piter->sg);  in __sg_page_iter_next()
752 		piter->sg = sg_next(piter->sg);  in __sg_page_iter_next()
753 		if (!--piter->__nents || !piter->sg)  in __sg_page_iter_next()
761 static int sg_dma_page_count(struct scatterlist *sg)  in sg_dma_page_count()  argument
763 	return PAGE_ALIGN(sg->offset + sg_dma_len(sg)) >> PAGE_SHIFT;  in sg_dma_page_count()
770 	if (!piter->__nents || !piter->sg)  in __sg_page_iter_dma_next()
776 	while (piter->sg_pgoffset >= sg_dma_page_count(piter->sg)) {  in __sg_page_iter_dma_next()
777 		piter->sg_pgoffset -= sg_dma_page_count(piter->sg);  in __sg_page_iter_dma_next()
778 		piter->sg = sg_next(piter->sg);  in __sg_page_iter_dma_next()
779 		if (!--piter->__nents || !piter->sg)  in __sg_page_iter_dma_next()
788  * sg_miter_start - start mapping iteration over a sg list
789  * @miter: sg mapping iter to be started
790  * @sgl: sg list to iterate over
791  * @nents: number of sg entries
792  * @flags: sg iterator flags
814 		struct scatterlist *sg;  in sg_miter_get_next_page()  local
819 		sg = miter->piter.sg;  in sg_miter_get_next_page()
821 		miter->__offset = miter->piter.sg_pgoffset ? 0 : sg->offset;  in sg_miter_get_next_page()
824 		miter->__remaining = sg->offset + sg->length -  in sg_miter_get_next_page()
836  * @miter: sg mapping iter to be skipped
848  *   true if @miter contains the valid mapping.  false if end of sg
873  * @miter: sg mapping iter to proceed
884  *   true if @miter contains the next mapping.  false if end of sg
912  * @miter: sg mapping iter to be stopped
950  * sg_copy_buffer - Copy data between a linear buffer and an SG list
951  * @sgl:		 The SG list
952  * @nents:		 Number of SG entries
956  * @to_buffer:		 transfer direction (true == from an sg list to a
957  *			 buffer, false == from a buffer to an sg list)
999  * sg_copy_from_buffer - Copy from a linear buffer to an SG list
1000  * @sgl:		 The SG list
1001  * @nents:		 Number of SG entries
1016  * sg_copy_to_buffer - Copy from an SG list to a linear buffer
1017  * @sgl:		 The SG list
1018  * @nents:		 Number of SG entries
1033  * sg_pcopy_from_buffer - Copy from a linear buffer to an SG list
1034  * @sgl:		 The SG list
1035  * @nents:		 Number of SG entries
1051  * sg_pcopy_to_buffer - Copy from an SG list to a linear buffer
1052  * @sgl:		 The SG list
1053  * @nents:		 Number of SG entries
1069  * sg_zero_buffer - Zero-out a part of a SG list
1070  * @sgl:		 The SG list
1071  * @nents:		 Number of SG entries
1113 	struct scatterlist *sg = sgtable->sgl + sgtable->nents;  in extract_user_to_sg()  local
1141 			sg_set_page(sg, page, seg, off);  in extract_user_to_sg()
1143 			sg++;  in extract_user_to_sg()
1168 	struct scatterlist *sg = sgtable->sgl + sgtable->nents;  in extract_bvec_to_sg()  local
1185 		sg_set_page(sg, bv[i].bv_page, len, off);  in extract_bvec_to_sg()
1187 		sg++;  in extract_bvec_to_sg()
1214 	struct scatterlist *sg = sgtable->sgl + sgtable->nents;  in extract_kvec_to_sg()  local
1244 			sg_set_page(sg, page, len, off);  in extract_kvec_to_sg()
1246 			sg++;  in extract_kvec_to_sg()
1274 	struct scatterlist *sg = sgtable->sgl + sgtable->nents;  in extract_xarray_to_sg()  local
1296 		sg_set_page(sg, folio_page(folio, 0), len, offset);  in extract_xarray_to_sg()
1298 		sg++;  in extract_xarray_to_sg()