4 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public Licens
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
23 #include <linux/highmem.h>
24 #include <linux/mempool.h>
25 #include <linux/ioprio.h>
31 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
32 #include <linux/blk_types.h>
37 #define BIO_BUG_ON BUG_ON
42 #define BIO_MAX_PAGES 256
43 #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
44 #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
47 * upper 16 bits of bi_rw define the io priority of this bio
49 #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
50 #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
51 #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
53 #define bio_set_prio(bio, prio) do { \
54 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
55 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
56 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
60 * various member access, note that bio_data should of course not be used
61 * on highmem page vectors
63 #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
64 #define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
65 #define bio_page(bio) bio_iovec((bio))->bv_page
66 #define bio_offset(bio) bio_iovec((bio))->bv_offset
67 #define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
68 #define bio_sectors(bio) ((bio)->bi_size >> 9)
70 static inline unsigned int bio_cur_bytes(struct bio
*bio
)
73 return bio_iovec(bio
)->bv_len
;
74 else /* dataless requests such as discard */
78 static inline void *bio_data(struct bio
*bio
)
81 return page_address(bio_page(bio
)) + bio_offset(bio
);
86 static inline int bio_has_allocated_vec(struct bio
*bio
)
88 return bio
->bi_io_vec
&& bio
->bi_io_vec
!= bio
->bi_inline_vecs
;
94 #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
95 #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
98 * queues that have highmem support enabled may still need to revert to
99 * PIO transfers occasionally and thus map high pages temporarily. For
100 * permanent PIO fall back, user is probably better off disabling highmem
101 * I/O completely on that queue (see ide-dma for example)
103 #define __bio_kmap_atomic(bio, idx, kmtype) \
104 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
105 bio_iovec_idx((bio), (idx))->bv_offset)
107 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
113 #define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
114 #define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
116 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
117 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
118 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
121 * allow arch override, for eg virtualized architectures (put in asm/io.h)
123 #ifndef BIOVEC_PHYS_MERGEABLE
124 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
125 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
128 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
129 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
130 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
131 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
132 #define BIO_SEG_BOUNDARY(q, b1, b2) \
133 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
135 #define bio_io_error(bio) bio_endio((bio), -EIO)
138 * drivers should not use the __ version unless they _really_ want to
139 * run through the entire bio and not just pending pieces
141 #define __bio_for_each_segment(bvl, bio, i, start_idx) \
142 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
143 i < (bio)->bi_vcnt; \
146 #define bio_for_each_segment(bvl, bio, i) \
147 __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
150 * get a reference to a bio, so it won't disappear. the intended use is
154 * submit_bio(rw, bio);
155 * if (bio->bi_flags ...)
159 * without the bio_get(), it could potentially complete I/O before submit_bio
160 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
163 #define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
165 #if defined(CONFIG_BLK_DEV_INTEGRITY)
167 * bio integrity payload
169 struct bio_integrity_payload
{
170 struct bio
*bip_bio
; /* parent bio */
172 sector_t bip_sector
; /* virtual start sector */
174 void *bip_buf
; /* generated integrity data */
175 bio_end_io_t
*bip_end_io
; /* saved I/O completion fn */
177 unsigned int bip_size
;
179 unsigned short bip_slab
; /* slab the bip came from */
180 unsigned short bip_vcnt
; /* # of integrity bio_vecs */
181 unsigned short bip_idx
; /* current bip_vec index */
183 struct work_struct bip_work
; /* I/O completion */
184 struct bio_vec bip_vec
[0]; /* embedded bvec array */
186 #endif /* CONFIG_BLK_DEV_INTEGRITY */
189 * A bio_pair is used when we need to split a bio.
190 * This can only happen for a bio that refers to just one
191 * page of data, and in the unusual situation when the
192 * page crosses a chunk/device boundary
194 * The address of the master bio is stored in bio1.bi_private
195 * The address of the pool the pair was allocated from is stored
199 struct bio bio1
, bio2
;
200 struct bio_vec bv1
, bv2
;
201 #if defined(CONFIG_BLK_DEV_INTEGRITY)
202 struct bio_integrity_payload bip1
, bip2
;
203 struct bio_vec iv1
, iv2
;
208 extern struct bio_pair
*bio_split(struct bio
*bi
, int first_sectors
);
209 extern void bio_pair_release(struct bio_pair
*dbio
);
211 extern struct bio_set
*bioset_create(unsigned int, unsigned int);
212 extern void bioset_free(struct bio_set
*);
214 extern struct bio
*bio_alloc(gfp_t
, int);
215 extern struct bio
*bio_kmalloc(gfp_t
, int);
216 extern struct bio
*bio_alloc_bioset(gfp_t
, int, struct bio_set
*);
217 extern void bio_put(struct bio
*);
218 extern void bio_free(struct bio
*, struct bio_set
*);
220 extern void bio_endio(struct bio
*, int);
221 struct request_queue
;
222 extern int bio_phys_segments(struct request_queue
*, struct bio
*);
224 extern void __bio_clone(struct bio
*, struct bio
*);
225 extern struct bio
*bio_clone(struct bio
*, gfp_t
);
227 extern void bio_init(struct bio
*);
229 extern int bio_add_page(struct bio
*, struct page
*, unsigned int,unsigned int);
230 extern int bio_add_pc_page(struct request_queue
*, struct bio
*, struct page
*,
231 unsigned int, unsigned int);
232 extern int bio_get_nr_vecs(struct block_device
*);
233 extern sector_t
bio_sector_offset(struct bio
*, unsigned short, unsigned int);
234 extern struct bio
*bio_map_user(struct request_queue
*, struct block_device
*,
235 unsigned long, unsigned int, int, gfp_t
);
238 extern struct bio
*bio_map_user_iov(struct request_queue
*,
239 struct block_device
*,
240 struct sg_iovec
*, int, int, gfp_t
);
241 extern void bio_unmap_user(struct bio
*);
242 extern struct bio
*bio_map_kern(struct request_queue
*, void *, unsigned int,
244 extern struct bio
*bio_copy_kern(struct request_queue
*, void *, unsigned int,
246 extern void bio_set_pages_dirty(struct bio
*bio
);
247 extern void bio_check_pages_dirty(struct bio
*bio
);
249 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
250 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
252 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
253 extern void bio_flush_dcache_pages(struct bio
*bi
);
255 static inline void bio_flush_dcache_pages(struct bio
*bi
)
260 extern struct bio
*bio_copy_user(struct request_queue
*, struct rq_map_data
*,
261 unsigned long, unsigned int, int, gfp_t
);
262 extern struct bio
*bio_copy_user_iov(struct request_queue
*,
263 struct rq_map_data
*, struct sg_iovec
*,
265 extern int bio_uncopy_user(struct bio
*);
266 void zero_fill_bio(struct bio
*bio
);
267 extern struct bio_vec
*bvec_alloc_bs(gfp_t
, int, unsigned long *, struct bio_set
*);
268 extern void bvec_free_bs(struct bio_set
*, struct bio_vec
*, unsigned int);
269 extern unsigned int bvec_nr_vecs(unsigned short idx
);
272 * Allow queuer to specify a completion CPU for this bio
274 static inline void bio_set_completion_cpu(struct bio
*bio
, unsigned int cpu
)
276 bio
->bi_comp_cpu
= cpu
;
280 * bio_set is used to allow other portions of the IO system to
281 * allocate their own private memory pools for bio and iovec structures.
282 * These memory pools in turn all allocate from the bio_slab
283 * and the bvec_slabs[].
285 #define BIO_POOL_SIZE 2
286 #define BIOVEC_NR_POOLS 6
287 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
290 struct kmem_cache
*bio_slab
;
291 unsigned int front_pad
;
294 #if defined(CONFIG_BLK_DEV_INTEGRITY)
295 mempool_t
*bio_integrity_pool
;
297 mempool_t
*bvec_pool
;
303 struct kmem_cache
*slab
;
306 extern struct bio_set
*fs_bio_set
;
307 extern struct biovec_slab bvec_slabs
[BIOVEC_NR_POOLS
] __read_mostly
;
310 * a small number of entries is fine, not going to be performance critical.
311 * basically we just need to survive
313 #define BIO_SPLIT_ENTRIES 2
315 #ifdef CONFIG_HIGHMEM
317 * remember never ever reenable interrupts between a bvec_kmap_irq and
320 static inline char *bvec_kmap_irq(struct bio_vec
*bvec
, unsigned long *flags
)
325 * might not be a highmem page, but the preempt/irq count
326 * balancing is a lot nicer this way
328 local_irq_save(*flags
);
329 addr
= (unsigned long) kmap_atomic(bvec
->bv_page
, KM_BIO_SRC_IRQ
);
331 BUG_ON(addr
& ~PAGE_MASK
);
333 return (char *) addr
+ bvec
->bv_offset
;
336 static inline void bvec_kunmap_irq(char *buffer
, unsigned long *flags
)
338 unsigned long ptr
= (unsigned long) buffer
& PAGE_MASK
;
340 kunmap_atomic((void *) ptr
, KM_BIO_SRC_IRQ
);
341 local_irq_restore(*flags
);
345 static inline char *bvec_kmap_irq(struct bio_vec
*bvec
, unsigned long *flags
)
347 return page_address(bvec
->bv_page
) + bvec
->bv_offset
;
350 static inline void bvec_kunmap_irq(char *buffer
, unsigned long *flags
)
356 static inline char *__bio_kmap_irq(struct bio
*bio
, unsigned short idx
,
357 unsigned long *flags
)
359 return bvec_kmap_irq(bio_iovec_idx(bio
, idx
), flags
);
361 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
363 #define bio_kmap_irq(bio, flags) \
364 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
365 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
368 * Check whether this bio carries any data or not. A NULL bio is allowed.
370 static inline int bio_has_data(struct bio
*bio
)
372 return bio
&& bio
->bi_io_vec
!= NULL
;
376 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
378 * A bio_list anchors a singly-linked list of bios chained through the bi_next
379 * member of the bio. The bio_list also caches the last list member to allow
380 * fast access to the tail.
387 static inline int bio_list_empty(const struct bio_list
*bl
)
389 return bl
->head
== NULL
;
392 static inline void bio_list_init(struct bio_list
*bl
)
394 bl
->head
= bl
->tail
= NULL
;
397 #define bio_list_for_each(bio, bl) \
398 for (bio = (bl)->head; bio; bio = bio->bi_next)
400 static inline unsigned bio_list_size(const struct bio_list
*bl
)
405 bio_list_for_each(bio
, bl
)
411 static inline void bio_list_add(struct bio_list
*bl
, struct bio
*bio
)
416 bl
->tail
->bi_next
= bio
;
423 static inline void bio_list_add_head(struct bio_list
*bl
, struct bio
*bio
)
425 bio
->bi_next
= bl
->head
;
433 static inline void bio_list_merge(struct bio_list
*bl
, struct bio_list
*bl2
)
439 bl
->tail
->bi_next
= bl2
->head
;
441 bl
->head
= bl2
->head
;
443 bl
->tail
= bl2
->tail
;
446 static inline void bio_list_merge_head(struct bio_list
*bl
,
447 struct bio_list
*bl2
)
453 bl2
->tail
->bi_next
= bl
->head
;
455 bl
->tail
= bl2
->tail
;
457 bl
->head
= bl2
->head
;
460 static inline struct bio
*bio_list_peek(struct bio_list
*bl
)
465 static inline struct bio
*bio_list_pop(struct bio_list
*bl
)
467 struct bio
*bio
= bl
->head
;
470 bl
->head
= bl
->head
->bi_next
;
480 static inline struct bio
*bio_list_get(struct bio_list
*bl
)
482 struct bio
*bio
= bl
->head
;
484 bl
->head
= bl
->tail
= NULL
;
489 #if defined(CONFIG_BLK_DEV_INTEGRITY)
491 #define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
492 #define bip_vec(bip) bip_vec_idx(bip, 0)
494 #define __bip_for_each_vec(bvl, bip, i, start_idx) \
495 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
496 i < (bip)->bip_vcnt; \
499 #define bip_for_each_vec(bvl, bip, i) \
500 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
502 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
504 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
506 #define bio_integrity(bio) (bio->bi_integrity != NULL)
508 extern struct bio_integrity_payload
*bio_integrity_alloc_bioset(struct bio
*, gfp_t
, unsigned int, struct bio_set
*);
509 extern struct bio_integrity_payload
*bio_integrity_alloc(struct bio
*, gfp_t
, unsigned int);
510 extern void bio_integrity_free(struct bio
*, struct bio_set
*);
511 extern int bio_integrity_add_page(struct bio
*, struct page
*, unsigned int, unsigned int);
512 extern int bio_integrity_enabled(struct bio
*bio
);
513 extern int bio_integrity_set_tag(struct bio
*, void *, unsigned int);
514 extern int bio_integrity_get_tag(struct bio
*, void *, unsigned int);
515 extern int bio_integrity_prep(struct bio
*);
516 extern void bio_integrity_endio(struct bio
*, int);
517 extern void bio_integrity_advance(struct bio
*, unsigned int);
518 extern void bio_integrity_trim(struct bio
*, unsigned int, unsigned int);
519 extern void bio_integrity_split(struct bio
*, struct bio_pair
*, int);
520 extern int bio_integrity_clone(struct bio
*, struct bio
*, gfp_t
, struct bio_set
*);
521 extern int bioset_integrity_create(struct bio_set
*, int);
522 extern void bioset_integrity_free(struct bio_set
*);
523 extern void bio_integrity_init(void);
525 #else /* CONFIG_BLK_DEV_INTEGRITY */
527 #define bio_integrity(a) (0)
528 #define bioset_integrity_create(a, b) (0)
529 #define bio_integrity_prep(a) (0)
530 #define bio_integrity_enabled(a) (0)
531 #define bio_integrity_clone(a, b, c, d) (0)
532 #define bioset_integrity_free(a) do { } while (0)
533 #define bio_integrity_free(a, b) do { } while (0)
534 #define bio_integrity_endio(a, b) do { } while (0)
535 #define bio_integrity_advance(a, b) do { } while (0)
536 #define bio_integrity_trim(a, b, c) do { } while (0)
537 #define bio_integrity_split(a, b, c) do { } while (0)
538 #define bio_integrity_set_tag(a, b, c) do { } while (0)
539 #define bio_integrity_get_tag(a, b, c) do { } while (0)
540 #define bio_integrity_init(a) do { } while (0)
542 #endif /* CONFIG_BLK_DEV_INTEGRITY */
544 #endif /* CONFIG_BLOCK */
545 #endif /* __LINUX_BIO_H */