include/linux/bvec.h

3  * bvec iterator
25  * The following holds for a bvec if n * PAGE_SIZE < bv_offset + bv_len:
38  * bvec_set_page - initialize a bvec based off a struct page
39  * @bv:		bvec to initialize
40  * @page:	page the bvec should point to
41  * @len:	length of the bvec
53  * bvec_set_folio - initialize a bvec based off a struct folio
54  * @bv:		bvec to initialize
55  * @folio:	folio the bvec should point to
56  * @len:	length of the bvec
66  * bvec_set_virt - initialize a bvec based on a virtual address
67  * @bv:		bvec to initialize
68  * @vaddr:	virtual address to set the bvec to
69  * @len:	length of the bvec
85 						   current bvec */
98 #define __bvec_iter_bvec(bvec, iter)	(&(bvec)[(iter).bi_idx])
101 #define mp_bvec_iter_page(bvec, iter)				\
102 	(__bvec_iter_bvec((bvec), (iter))->bv_page)
104 #define mp_bvec_iter_len(bvec, iter)				\
106 	    __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
108 #define mp_bvec_iter_offset(bvec, iter)				\
109 	(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
111 #define mp_bvec_iter_page_idx(bvec, iter)			\
112 	(mp_bvec_iter_offset((bvec), (iter)) / PAGE_SIZE)
114 #define mp_bvec_iter_bvec(bvec, iter)				\
116 	.bv_page	= mp_bvec_iter_page((bvec), (iter)),	\
117 	.bv_len		= mp_bvec_iter_len((bvec), (iter)),	\
118 	.bv_offset	= mp_bvec_iter_offset((bvec), (iter)),	\
121 /* For building single-page bvec in flight */
122  #define bvec_iter_offset(bvec, iter)				\
123 	(mp_bvec_iter_offset((bvec), (iter)) % PAGE_SIZE)
125 #define bvec_iter_len(bvec, iter)				\
126 	min_t(unsigned, mp_bvec_iter_len((bvec), (iter)),		\
127 	      PAGE_SIZE - bvec_iter_offset((bvec), (iter)))
129 #define bvec_iter_page(bvec, iter)				\
130 	(mp_bvec_iter_page((bvec), (iter)) +			\
131 	 mp_bvec_iter_page_idx((bvec), (iter)))
133 #define bvec_iter_bvec(bvec, iter)				\
135 	.bv_page	= bvec_iter_page((bvec), (iter)),	\
136 	.bv_len		= bvec_iter_len((bvec), (iter)),	\
137 	.bv_offset	= bvec_iter_offset((bvec), (iter)),	\
146 		     "Attempted to advance past end of bvec iter\n")) {
166  * across multiple bvec entries, i.e. bytes <= bv[i->bi_idx].bv_len
204 static inline void bvec_advance(const struct bio_vec *bvec,
213 		bv->bv_page = bvec->bv_page + (bvec->bv_offset >> PAGE_SHIFT);
214 		bv->bv_offset = bvec->bv_offset & ~PAGE_MASK;
217 			   bvec->bv_len - iter_all->done);
220 	if (iter_all->done == bvec->bv_len) {
227  * bvec_kmap_local - map a bvec into the kernel virtual address space
228  * @bvec: bvec to map
233 static inline void *bvec_kmap_local(struct bio_vec *bvec)
235 	return kmap_local_page(bvec->bv_page) + bvec->bv_offset;
239  * memcpy_from_bvec - copy data from a bvec
240  * @bvec: bvec to copy from
244 static inline void memcpy_from_bvec(char *to, struct bio_vec *bvec)
246 	memcpy_from_page(to, bvec->bv_page, bvec->bv_offset, bvec->bv_len);
250  * memcpy_to_bvec - copy data to a bvec
251  * @bvec: bvec to copy to
255 static inline void memcpy_to_bvec(struct bio_vec *bvec, const char *from)
257 	memcpy_to_page(bvec->bv_page, bvec->bv_offset, from, bvec->bv_len);
261  * memzero_bvec - zero all data in a bvec
262  * @bvec: bvec to zero
266 static inline void memzero_bvec(struct bio_vec *bvec)
268 	memzero_page(bvec->bv_page, bvec->bv_offset, bvec->bv_len);
272  * bvec_virt - return the virtual address for a bvec
273  * @bvec: bvec to return the virtual address for
275  * Note: the caller must ensure that @bvec->bv_page is not a highmem page.
277 static inline void *bvec_virt(struct bio_vec *bvec)
279 	WARN_ON_ONCE(PageHighMem(bvec->bv_page));
280 	return page_address(bvec->bv_page) + bvec->bv_offset;