linux-master/lib/scatterlist.c

49 	int nents;
50 	for (nents = 0; sg; sg = sg_next(sg))
51 		nents++;
52 	return nents;
72 	int nents;
78 	for (nents = 0, total = 0; sg; sg = sg_next(sg)) {
79 		nents++;
82 			return nents;
92  * @nents:	Number of entries in the scatterlist
99  *   the important bit is that @nents@ denotes the number of entries that
103 struct scatterlist *sg_last(struct scatterlist *sgl, unsigned int nents)
108 	for_each_sg(sgl, sg, nents, i)
119  * @nents:	   Number of entries in table
126 void sg_init_table(struct scatterlist *sgl, unsigned int nents)
128 	memset(sgl, 0, sizeof(*sgl) * nents);
129 	sg_init_marker(sgl, nents);
151 static struct scatterlist *sg_kmalloc(unsigned int nents, gfp_t gfp_mask)
153 	if (nents == SG_MAX_SINGLE_ALLOC) {
167 		return kmalloc_array(nents, sizeof(struct scatterlist),
171 static void sg_kfree(struct scatterlist *sg, unsigned int nents)
173 	if (nents == SG_MAX_SINGLE_ALLOC) {
266  * @nents:	Number of entries in sg list
275  *   This function returns a @table @nents long. The allocator is
277  *   Thus if @nents is bigger than @max_ents, the scatterlists will be
285 int __sg_alloc_table(struct sg_table *table, unsigned int nents,
297 	if (nents == 0)
300 	if (WARN_ON_ONCE(nents > max_ents))
304 	left = nents;
331 				table->nents = ++table->orig_nents;
337 		table->nents = table->orig_nents += sg_size;
366  * @nents:	Number of entries in sg list
370  *    Allocate and initialize an sg table. If @nents@ is larger than
374 int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
378 	ret = __sg_alloc_table(table, nents, SG_MAX_SINGLE_ALLOC,
545 	sgt_append->sgt.nents += added_nents;
546 	sgt_append->sgt.orig_nents = sgt_append->sgt.nents;
675  * @nents: Maximum number of elements to free
680  *   freed separately then it's essential to set nents correctly to avoid that a
682  * - All pages in a chained scatterlist can be freed at once by setting @nents
685 void sgl_free_n_order(struct scatterlist *sgl, int nents, int order)
691 	for_each_sg(sgl, sg, nents, i) {
726 			  struct scatterlist *sglist, unsigned int nents,
730 	piter->__nents = nents;
791  * @nents: number of sg entries
801 		    unsigned int nents, unsigned int flags)
805 	__sg_page_iter_start(&miter->piter, sgl, nents, 0);
952  * @nents:		 Number of SG entries
962 size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
974 	sg_miter_start(&miter, sgl, nents, sg_flags);
1001  * @nents:		 Number of SG entries
1008 size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents,
1011 	return sg_copy_buffer(sgl, nents, (void *)buf, buflen, 0, false);
1018  * @nents:		 Number of SG entries
1025 size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
1028 	return sg_copy_buffer(sgl, nents, buf, buflen, 0, true);
1035  * @nents:		 Number of SG entries
1043 size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents,
1046 	return sg_copy_buffer(sgl, nents, (void *)buf, buflen, skip, false);
1053  * @nents:		 Number of SG entries
1061 size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents,
1064 	return sg_copy_buffer(sgl, nents, buf, buflen, skip, true);
1071  * @nents:		 Number of SG entries
1077 size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents,
1084 	sg_miter_start(&miter, sgl, nents, sg_flags);
1113 	struct scatterlist *sg = sgtable->sgl + sgtable->nents;
1142 			sgtable->nents++;
1152 	while (sgtable->nents > sgtable->orig_nents)
1153 		unpin_user_page(sg_page(&sgtable->sgl[--sgtable->nents]));
1168 	struct scatterlist *sg = sgtable->sgl + sgtable->nents;
1186 		sgtable->nents++;
1214 	struct scatterlist *sg = sgtable->sgl + sgtable->nents;
1245 			sgtable->nents++;
1274 	struct scatterlist *sg = sgtable->sgl + sgtable->nents;
1297 		sgtable->nents++;
1334  * If successful, @sgtable->nents is updated to include the number of elements