801 void sg_miter_start(struct sg_mapping_iter *miter, struct scatterlist *sgl,  in sg_miter_start()  argument
804 	memset(miter, 0, sizeof(struct sg_mapping_iter));  in sg_miter_start()
806 	__sg_page_iter_start(&miter->piter, sgl, nents, 0);  in sg_miter_start()
808 	miter->__flags = flags;  in sg_miter_start()
812 static bool sg_miter_get_next_page(struct sg_mapping_iter *miter)  in sg_miter_get_next_page()  argument
814 	if (!miter->__remaining) {  in sg_miter_get_next_page()
817 		if (!__sg_page_iter_next(&miter->piter))  in sg_miter_get_next_page()
820 		sg = miter->piter.sg;  in sg_miter_get_next_page()
822 		miter->__offset = miter->piter.sg_pgoffset ? 0 : sg->offset;  in sg_miter_get_next_page()
823 		miter->piter.sg_pgoffset += miter->__offset >> PAGE_SHIFT;  in sg_miter_get_next_page()
824 		miter->__offset &= PAGE_SIZE - 1;  in sg_miter_get_next_page()
825 		miter->__remaining = sg->offset + sg->length -  in sg_miter_get_next_page()
826 				     (miter->piter.sg_pgoffset << PAGE_SHIFT) -  in sg_miter_get_next_page()
827 				     miter->__offset;  in sg_miter_get_next_page()
828 		miter->__remaining = min_t(unsigned long, miter->__remaining,  in sg_miter_get_next_page()
829 					   PAGE_SIZE - miter->__offset);  in sg_miter_get_next_page()
852 bool sg_miter_skip(struct sg_mapping_iter *miter, off_t offset)  in sg_miter_skip()  argument
854 	sg_miter_stop(miter);  in sg_miter_skip()
859 		if (!sg_miter_get_next_page(miter))  in sg_miter_skip()
862 		consumed = min_t(off_t, offset, miter->__remaining);  in sg_miter_skip()
863 		miter->__offset += consumed;  in sg_miter_skip()
864 		miter->__remaining -= consumed;  in sg_miter_skip()
888 bool sg_miter_next(struct sg_mapping_iter *miter)  in sg_miter_next()  argument
890 	sg_miter_stop(miter);  in sg_miter_next()
896 	if (!sg_miter_get_next_page(miter))  in sg_miter_next()
899 	miter->page = sg_page_iter_page(&miter->piter);  in sg_miter_next()
900 	miter->consumed = miter->length = miter->__remaining;  in sg_miter_next()
902 	if (miter->__flags & SG_MITER_ATOMIC)  in sg_miter_next()
903 		miter->addr = kmap_atomic(miter->page) + miter->__offset;  in sg_miter_next()
904 	else if (miter->__flags & SG_MITER_LOCAL)  in sg_miter_next()
905 		miter->addr = kmap_local_page(miter->page) + miter->__offset;  in sg_miter_next()
907 		miter->addr = kmap(miter->page) + miter->__offset;  in sg_miter_next()
926 void sg_miter_stop(struct sg_mapping_iter *miter)  in sg_miter_stop()  argument
928 	WARN_ON(miter->consumed > miter->length);  in sg_miter_stop()
931 	if (miter->addr) {  in sg_miter_stop()
932 		miter->__offset += miter->consumed;  in sg_miter_stop()
933 		miter->__remaining -= miter->consumed;  in sg_miter_stop()
935 		if (miter->__flags & SG_MITER_TO_SG)  in sg_miter_stop()
936 			flush_dcache_page(miter->page);  in sg_miter_stop()
938 		if (miter->__flags & SG_MITER_ATOMIC) {  in sg_miter_stop()
940 			kunmap_atomic(miter->addr);  in sg_miter_stop()
941 		} else if (miter->__flags & SG_MITER_LOCAL)  in sg_miter_stop()
942 			kunmap_local(miter->addr);  in sg_miter_stop()
944 			kunmap(miter->page);  in sg_miter_stop()
946 		miter->page = NULL;  in sg_miter_stop()
947 		miter->addr = NULL;  in sg_miter_stop()
948 		miter->length = 0;  in sg_miter_stop()
949 		miter->consumed = 0;  in sg_miter_stop()
971 	struct sg_mapping_iter miter;  in sg_copy_buffer()  local
979 	sg_miter_start(&miter, sgl, nents, sg_flags);  in sg_copy_buffer()
981 	if (!sg_miter_skip(&miter, skip))  in sg_copy_buffer()
984 	while ((offset < buflen) && sg_miter_next(&miter)) {  in sg_copy_buffer()
987 		len = min(miter.length, buflen - offset);  in sg_copy_buffer()
990 			memcpy(buf + offset, miter.addr, len);  in sg_copy_buffer()
992 			memcpy(miter.addr, buf + offset, len);  in sg_copy_buffer()
997 	sg_miter_stop(&miter);  in sg_copy_buffer()
1086 	struct sg_mapping_iter miter;  in sg_zero_buffer()  local
1089 	sg_miter_start(&miter, sgl, nents, sg_flags);  in sg_zero_buffer()
1091 	if (!sg_miter_skip(&miter, skip))  in sg_zero_buffer()
1094 	while (offset < buflen && sg_miter_next(&miter)) {  in sg_zero_buffer()
1097 		len = min(miter.length, buflen - offset);  in sg_zero_buffer()
1098 		memset(miter.addr, 0, len);  in sg_zero_buffer()
1103 	sg_miter_stop(&miter);  in sg_zero_buffer()