1 /* SPDX-License-Identifier: GPL-2.0 */
17 struct page;
20  * struct bio_vec - a contiguous range of physical memory addresses
21  * @bv_page:   First page associated with the address range.
32 	struct page	*bv_page;
38  * bvec_set_page - initialize a bvec based off a struct page
40  * @page:	page the bvec should point to
42  * @offset:	offset into the page
44 static inline void bvec_set_page(struct bio_vec *bv, struct page *page,  in bvec_set_page()  argument
47 	bv->bv_page = page;  in bvec_set_page()
48 	bv->bv_len = len;  in bvec_set_page()
49 	bv->bv_offset = offset;  in bvec_set_page()
53  * bvec_set_folio - initialize a bvec based off a struct folio
62 	bvec_set_page(bv, &folio->page, len, offset);  in bvec_set_folio()
66  * bvec_set_virt - initialize a bvec based on a virtual address
96  * on highmem page vectors
100 /* multi-page (mp_bvec) helpers */
102 	(__bvec_iter_bvec((bvec), (iter))->bv_page)
106 	    __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
109 	(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
121 /* For building single-page bvec in flight */
127 	      PAGE_SIZE - bvec_iter_offset((bvec), (iter)))
143 	unsigned int idx = iter->bi_idx;  in bvec_iter_advance()
145 	if (WARN_ONCE(bytes > iter->bi_size,  in bvec_iter_advance()
147 		iter->bi_size = 0;  in bvec_iter_advance()
151 	iter->bi_size -= bytes;  in bvec_iter_advance()
152 	bytes += iter->bi_bvec_done;  in bvec_iter_advance()
155 		bytes -= bv[idx].bv_len;  in bvec_iter_advance()
159 	iter->bi_idx = idx;  in bvec_iter_advance()
160 	iter->bi_bvec_done = bytes;  in bvec_iter_advance()
166  * across multiple bvec entries, i.e. bytes <= bv[i->bi_idx].bv_len
171 	unsigned int done = iter->bi_bvec_done + bytes;  in bvec_iter_advance_single()
173 	if (done == bv[iter->bi_idx].bv_len) {  in bvec_iter_advance_single()
175 		iter->bi_idx++;  in bvec_iter_advance_single()
177 	iter->bi_bvec_done = done;  in bvec_iter_advance_single()
178 	iter->bi_size -= bytes;  in bvec_iter_advance_single()
198 	iter_all->done = 0;  in bvec_init_iter_all()
199 	iter_all->idx = 0;  in bvec_init_iter_all()
201 	return &iter_all->bv;  in bvec_init_iter_all()
207 	struct bio_vec *bv = &iter_all->bv;  in bvec_advance()
209 	if (iter_all->done) {  in bvec_advance()
210 		bv->bv_page++;  in bvec_advance()
211 		bv->bv_offset = 0;  in bvec_advance()
213 		bv->bv_page = bvec->bv_page + (bvec->bv_offset >> PAGE_SHIFT);  in bvec_advance()
214 		bv->bv_offset = bvec->bv_offset & ~PAGE_MASK;  in bvec_advance()
216 	bv->bv_len = min_t(unsigned int, PAGE_SIZE - bv->bv_offset,  in bvec_advance()
217 			   bvec->bv_len - iter_all->done);  in bvec_advance()
218 	iter_all->done += bv->bv_len;  in bvec_advance()
220 	if (iter_all->done == bvec->bv_len) {  in bvec_advance()
221 		iter_all->idx++;  in bvec_advance()
222 		iter_all->done = 0;  in bvec_advance()
227  * bvec_kmap_local - map a bvec into the kernel virtual address space
230  * Must be called on single-page bvecs only.  Call kunmap_local on the returned
235 	return kmap_local_page(bvec->bv_page) + bvec->bv_offset;  in bvec_kmap_local()
239  * memcpy_from_bvec - copy data from a bvec
242  * Must be called on single-page bvecs only.
246 	memcpy_from_page(to, bvec->bv_page, bvec->bv_offset, bvec->bv_len);  in memcpy_from_bvec()
250  * memcpy_to_bvec - copy data to a bvec
253  * Must be called on single-page bvecs only.
257 	memcpy_to_page(bvec->bv_page, bvec->bv_offset, from, bvec->bv_len);  in memcpy_to_bvec()
261  * memzero_bvec - zero all data in a bvec
264  * Must be called on single-page bvecs only.
268 	memzero_page(bvec->bv_page, bvec->bv_offset, bvec->bv_len);  in memzero_bvec()
272  * bvec_virt - return the virtual address for a bvec
275  * Note: the caller must ensure that @bvec->bv_page is not a highmem page.
279 	WARN_ON_ONCE(PageHighMem(bvec->bv_page));  in bvec_virt()
280 	return page_address(bvec->bv_page) + bvec->bv_offset;  in bvec_virt()
284  * bvec_phys - return the physical address for a bvec
289 	return page_to_phys(bvec->bv_page) + bvec->bv_offset;  in bvec_phys()