15  * @sg:		The current sg entry
18  *   Usually the next entry will be @sg@ + 1, but if this sg element is part
23 struct scatterlist *sg_next(struct scatterlist *sg)  in sg_next()  argument
25 	if (sg_is_last(sg))  in sg_next()
28 	sg++;  in sg_next()
29 	if (unlikely(sg_is_chain(sg)))  in sg_next()
30 		sg = sg_chain_ptr(sg);  in sg_next()
32 	return sg;  in sg_next()
38  * @sg:		The scatterlist
41  * Allows to know how many entries are in sg, taking into acount
45 int sg_nents(struct scatterlist *sg)  in sg_nents()  argument
48 	for (nents = 0; sg; sg = sg_next(sg))  in sg_nents()
57  * @sg:		The scatterlist
61  * Determines the number of entries in sg that are required to meet
65  *   the number of sg entries needed, negative error on failure
68 int sg_nents_for_len(struct scatterlist *sg, u64 len)  in sg_nents_for_len()  argument
76 	for (nents = 0, total = 0; sg; sg = sg_next(sg)) {  in sg_nents_for_len()
78 		total += sg->length;  in sg_nents_for_len()
103 	struct scatterlist *sg, *ret = NULL;  in sg_last()  local
106 	for_each_sg(sgl, sg, nents, i)  in sg_last()
107 		ret = sg;  in sg_last()
115  * sg_init_table - Initialize SG table
116  * @sgl:	   The SG table
120  *   If this is part of a chained sg table, sg_mark_end() should be
132  * sg_init_one - Initialize a single entry sg list
133  * @sg:		 SG entry
138 void sg_init_one(struct scatterlist *sg, const void *buf, unsigned int buflen)  in sg_init_one()  argument
140 	sg_init_table(sg, 1);  in sg_init_one()
141 	sg_set_buf(sg, buf, buflen);  in sg_init_one()
169 static void sg_kfree(struct scatterlist *sg, unsigned int nents)  in sg_kfree()  argument
172 		kmemleak_free(sg);  in sg_kfree()
173 		free_page((unsigned long) sg);  in sg_kfree()
175 		kfree(sg);  in sg_kfree()
179  * __sg_free_table - Free a previously mapped sg table
180  * @table:	The sg table header to use
187  *    Free an sg table previously allocated and setup with
208 		 * then assign 'next' to the sg table after the current one.  in __sg_free_table()
235  * sg_free_table - Free a previously allocated sg table
236  * @table:	The mapped sg table header
246  * __sg_alloc_table - Allocate and initialize an sg table with given allocator
247  * @table:	The sg table header to use
248  * @nents:	Number of entries in sg list
271 	struct scatterlist *sg, *prv;  in __sg_alloc_table()  local
299 			sg = first_chunk;  in __sg_alloc_table()
302 			sg = alloc_fn(alloc_size, gfp_mask);  in __sg_alloc_table()
304 		if (unlikely(!sg)) {  in __sg_alloc_table()
317 		sg_init_table(sg, alloc_size);  in __sg_alloc_table()
321 		 * If this is the first mapping, assign the sg table header.  in __sg_alloc_table()
325 			sg_chain(prv, prv_max_ents, sg);  in __sg_alloc_table()
327 			table->sgl = sg;  in __sg_alloc_table()
333 			sg_mark_end(&sg[sg_size - 1]);  in __sg_alloc_table()
335 		prv = sg;  in __sg_alloc_table()
345  * sg_alloc_table - Allocate and initialize an sg table
346  * @table:	The sg table header to use
347  * @nents:	Number of entries in sg list
351  *    Allocate and initialize an sg table. If @nents@ is larger than
352  *    SG_MAX_SINGLE_ALLOC a chained sg table will be setup.
400  * __sg_alloc_table_from_pages - Allocate and initialize an sg table from
402  * @sgt:	 The sg table header to use
413  *    If @prv is NULL, allocate and initialize an sg table from a list of pages,
457 		/* Merge contiguous pages into the last SG */  in __sg_alloc_table_from_pages()
526  * sg_alloc_table_from_pages - Allocate and initialize an sg table from
528  * @sgt:	 The sg table header to use
536  *    Allocate and initialize an sg table from a list of pages. Contiguous
539  *    specified by the page array. The returned sg table is released by
571 	struct scatterlist *sgl, *sg;  in sgl_alloc_order()  local
593 	sg = sgl;  in sgl_alloc_order()
602 		sg_set_page(sg, page, elem_len, 0);  in sgl_alloc_order()
604 		sg = sg_next(sg);  in sgl_alloc_order()
643 	struct scatterlist *sg;  in sgl_free_n_order()  local
647 	for_each_sg(sgl, sg, nents, i) {  in sgl_free_n_order()
648 		if (!sg)  in sgl_free_n_order()
650 		page = sg_page(sg);  in sgl_free_n_order()
688 	piter->sg = sglist;  in __sg_page_iter_start()
693 static int sg_page_count(struct scatterlist *sg)  in sg_page_count()  argument
695 	return PAGE_ALIGN(sg->offset + sg->length) >> PAGE_SHIFT;  in sg_page_count()
700 	if (!piter->__nents || !piter->sg)  in __sg_page_iter_next()
706 	while (piter->sg_pgoffset >= sg_page_count(piter->sg)) {  in __sg_page_iter_next()
707 		piter->sg_pgoffset -= sg_page_count(piter->sg);  in __sg_page_iter_next()
708 		piter->sg = sg_next(piter->sg);  in __sg_page_iter_next()
709 		if (!--piter->__nents || !piter->sg)  in __sg_page_iter_next()
717 static int sg_dma_page_count(struct scatterlist *sg)  in sg_dma_page_count()  argument
719 	return PAGE_ALIGN(sg->offset + sg_dma_len(sg)) >> PAGE_SHIFT;  in sg_dma_page_count()
726 	if (!piter->__nents || !piter->sg)  in __sg_page_iter_dma_next()
732 	while (piter->sg_pgoffset >= sg_dma_page_count(piter->sg)) {  in __sg_page_iter_dma_next()
733 		piter->sg_pgoffset -= sg_dma_page_count(piter->sg);  in __sg_page_iter_dma_next()
734 		piter->sg = sg_next(piter->sg);  in __sg_page_iter_dma_next()
735 		if (!--piter->__nents || !piter->sg)  in __sg_page_iter_dma_next()
744  * sg_miter_start - start mapping iteration over a sg list
745  * @miter: sg mapping iter to be started
746  * @sgl: sg list to iterate over
747  * @nents: number of sg entries
769 		struct scatterlist *sg;  in sg_miter_get_next_page()  local
774 		sg = miter->piter.sg;  in sg_miter_get_next_page()
776 		miter->__offset = miter->piter.sg_pgoffset ? 0 : sg->offset;  in sg_miter_get_next_page()
779 		miter->__remaining = sg->offset + sg->length -  in sg_miter_get_next_page()
791  * @miter: sg mapping iter to be skipped
804  *   true if @miter contains the valid mapping.  false if end of sg
829  * @miter: sg mapping iter to proceed
841  *   true if @miter contains the next mapping.  false if end of sg
869  * @miter: sg mapping iter to be stopped
909  * sg_copy_buffer - Copy data between a linear buffer and an SG list
910  * @sgl:		 The SG list
911  * @nents:		 Number of SG entries
915  * @to_buffer:		 transfer direction (true == from an sg list to a
916  *			 buffer, false == from a buffer to an sg list)
958  * sg_copy_from_buffer - Copy from a linear buffer to an SG list
959  * @sgl:		 The SG list
960  * @nents:		 Number of SG entries
975  * sg_copy_to_buffer - Copy from an SG list to a linear buffer
976  * @sgl:		 The SG list
977  * @nents:		 Number of SG entries
992  * sg_pcopy_from_buffer - Copy from a linear buffer to an SG list
993  * @sgl:		 The SG list
994  * @nents:		 Number of SG entries
1010  * sg_pcopy_to_buffer - Copy from an SG list to a linear buffer
1011  * @sgl:		 The SG list
1012  * @nents:		 Number of SG entries
1028  * sg_zero_buffer - Zero-out a part of a SG list
1029  * @sgl:		 The SG list
1030  * @nents:		 Number of SG entries