[net-next-2.6.git] / include / linux / bio.h

/*
 * 2.5 block I/O model
 *
 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public Licens
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
 */
#ifndef __LINUX_BIO_H
#define __LINUX_BIO_H

#include <linux/highmem.h>
#include <linux/mempool.h>
#include <linux/ioprio.h>

#ifdef CONFIG_BLOCK

#include <asm/io.h>

/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
#include <linux/blk_types.h>

#define BIO_DEBUG

#ifdef BIO_DEBUG
#define BIO_BUG_ON	BUG_ON
#else
#define BIO_BUG_ON
#endif

#define BIO_MAX_PAGES		256
#define BIO_MAX_SIZE		(BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
#define BIO_MAX_SECTORS		(BIO_MAX_SIZE >> 9)

/*
 * upper 16 bits of bi_rw define the io priority of this bio
 */
#define BIO_PRIO_SHIFT	(8 * sizeof(unsigned long) - IOPRIO_BITS)
#define bio_prio(bio)	((bio)->bi_rw >> BIO_PRIO_SHIFT)
#define bio_prio_valid(bio)	ioprio_valid(bio_prio(bio))

#define bio_set_prio(bio, prio)		do {			\
	WARN_ON(prio >= (1 << IOPRIO_BITS));			\
	(bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);		\
	(bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);	\
} while (0)

/*
 * various member access, note that bio_data should of course not be used
 * on highmem page vectors
 */
#define bio_iovec_idx(bio, idx)	(&((bio)->bi_io_vec[(idx)]))
#define bio_iovec(bio)		bio_iovec_idx((bio), (bio)->bi_idx)
#define bio_page(bio)		bio_iovec((bio))->bv_page
#define bio_offset(bio)		bio_iovec((bio))->bv_offset
#define bio_segments(bio)	((bio)->bi_vcnt - (bio)->bi_idx)
#define bio_sectors(bio)	((bio)->bi_size >> 9)
#define bio_empty_barrier(bio) \
	((bio->bi_rw & REQ_HARDBARRIER) && \
	 !bio_has_data(bio) && \
	 !(bio->bi_rw & REQ_DISCARD))

static inline unsigned int bio_cur_bytes(struct bio *bio)
{
	if (bio->bi_vcnt)
		return bio_iovec(bio)->bv_len;
	else /* dataless requests such as discard */
		return bio->bi_size;
}

static inline void *bio_data(struct bio *bio)
{
	if (bio->bi_vcnt)
		return page_address(bio_page(bio)) + bio_offset(bio);

	return NULL;
}

static inline int bio_has_allocated_vec(struct bio *bio)
{
	return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
}

/*
 * will die
 */
#define bio_to_phys(bio)	(page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
#define bvec_to_phys(bv)	(page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)

/*
 * queues that have highmem support enabled may still need to revert to
 * PIO transfers occasionally and thus map high pages temporarily. For
 * permanent PIO fall back, user is probably better off disabling highmem
 * I/O completely on that queue (see ide-dma for example)
 */
#define __bio_kmap_atomic(bio, idx, kmtype)				\
	(kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) +	\
		bio_iovec_idx((bio), (idx))->bv_offset)

#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)

/*
 * merge helpers etc
 */

#define __BVEC_END(bio)		bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
#define __BVEC_START(bio)	bio_iovec_idx((bio), (bio)->bi_idx)

/* Default implementation of BIOVEC_PHYS_MERGEABLE */
#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))

/*
 * allow arch override, for eg virtualized architectures (put in asm/io.h)
 */
#ifndef BIOVEC_PHYS_MERGEABLE
#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
	__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
#endif

#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
#define BIO_SEG_BOUNDARY(q, b1, b2) \
	BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))

#define bio_io_error(bio) bio_endio((bio), -EIO)

/*
 * drivers should not use the __ version unless they _really_ want to
 * run through the entire bio and not just pending pieces
 */
#define __bio_for_each_segment(bvl, bio, i, start_idx)			\
	for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx);	\
	     i < (bio)->bi_vcnt;					\
	     bvl++, i++)

#define bio_for_each_segment(bvl, bio, i)				\
	__bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)

/*
 * get a reference to a bio, so it won't disappear. the intended use is
 * something like:
 *
 * bio_get(bio);
 * submit_bio(rw, bio);
 * if (bio->bi_flags ...)
 *	do_something
 * bio_put(bio);
 *
 * without the bio_get(), it could potentially complete I/O before submit_bio
 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
 * runs
 */
#define bio_get(bio)	atomic_inc(&(bio)->bi_cnt)

#if defined(CONFIG_BLK_DEV_INTEGRITY)
/*
 * bio integrity payload
 */
struct bio_integrity_payload {
	struct bio		*bip_bio;	/* parent bio */

	sector_t		bip_sector;	/* virtual start sector */

	void			*bip_buf;	/* generated integrity data */
	bio_end_io_t		*bip_end_io;	/* saved I/O completion fn */

	unsigned int		bip_size;

	unsigned short		bip_slab;	/* slab the bip came from */
	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
	unsigned short		bip_idx;	/* current bip_vec index */

	struct work_struct	bip_work;	/* I/O completion */
	struct bio_vec		bip_vec[0];	/* embedded bvec array */
};
#endif /* CONFIG_BLK_DEV_INTEGRITY */

/*
 * A bio_pair is used when we need to split a bio.
 * This can only happen for a bio that refers to just one
 * page of data, and in the unusual situation when the
 * page crosses a chunk/device boundary
 *
 * The address of the master bio is stored in bio1.bi_private
 * The address of the pool the pair was allocated from is stored
 *   in bio2.bi_private
 */
struct bio_pair {
	struct bio			bio1, bio2;
	struct bio_vec			bv1, bv2;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
	struct bio_integrity_payload	bip1, bip2;
	struct bio_vec			iv1, iv2;
#endif
	atomic_t			cnt;
	int				error;
};
extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
extern void bio_pair_release(struct bio_pair *dbio);

extern struct bio_set *bioset_create(unsigned int, unsigned int);
extern void bioset_free(struct bio_set *);

extern struct bio *bio_alloc(gfp_t, int);
extern struct bio *bio_kmalloc(gfp_t, int);
extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
extern void bio_put(struct bio *);
extern void bio_free(struct bio *, struct bio_set *);

extern void bio_endio(struct bio *, int);
struct request_queue;
extern int bio_phys_segments(struct request_queue *, struct bio *);

extern void __bio_clone(struct bio *, struct bio *);
extern struct bio *bio_clone(struct bio *, gfp_t);

extern void bio_init(struct bio *);

extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
			   unsigned int, unsigned int);
extern int bio_get_nr_vecs(struct block_device *);
extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
				unsigned long, unsigned int, int, gfp_t);
struct sg_iovec;
struct rq_map_data;
extern struct bio *bio_map_user_iov(struct request_queue *,
				    struct block_device *,
				    struct sg_iovec *, int, int, gfp_t);
extern void bio_unmap_user(struct bio *);
extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
				gfp_t);
extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
				 gfp_t, int);
extern void bio_set_pages_dirty(struct bio *bio);
extern void bio_check_pages_dirty(struct bio *bio);

#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
# error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
#endif
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
extern void bio_flush_dcache_pages(struct bio *bi);
#else
static inline void bio_flush_dcache_pages(struct bio *bi)
{
}
#endif

extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
				 unsigned long, unsigned int, int, gfp_t);
extern struct bio *bio_copy_user_iov(struct request_queue *,
				     struct rq_map_data *, struct sg_iovec *,
				     int, int, gfp_t);
extern int bio_uncopy_user(struct bio *);
void zero_fill_bio(struct bio *bio);
extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
extern unsigned int bvec_nr_vecs(unsigned short idx);

/*
 * Allow queuer to specify a completion CPU for this bio
 */
static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
{
	bio->bi_comp_cpu = cpu;
}

/*
 * bio_set is used to allow other portions of the IO system to
 * allocate their own private memory pools for bio and iovec structures.
 * These memory pools in turn all allocate from the bio_slab
 * and the bvec_slabs[].
 */
#define BIO_POOL_SIZE 2
#define BIOVEC_NR_POOLS 6
#define BIOVEC_MAX_IDX	(BIOVEC_NR_POOLS - 1)

struct bio_set {
	struct kmem_cache *bio_slab;
	unsigned int front_pad;

	mempool_t *bio_pool;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
	mempool_t *bio_integrity_pool;
#endif
	mempool_t *bvec_pool;
};

struct biovec_slab {
	int nr_vecs;
	char *name;
	struct kmem_cache *slab;
};

extern struct bio_set *fs_bio_set;
extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;

/*
 * a small number of entries is fine, not going to be performance critical.
 * basically we just need to survive
 */
#define BIO_SPLIT_ENTRIES 2

#ifdef CONFIG_HIGHMEM
/*
 * remember never ever reenable interrupts between a bvec_kmap_irq and
 * bvec_kunmap_irq!
 */
static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
{
	unsigned long addr;

	/*
	 * might not be a highmem page, but the preempt/irq count
	 * balancing is a lot nicer this way
	 */
	local_irq_save(*flags);
	addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);

	BUG_ON(addr & ~PAGE_MASK);

	return (char *) addr + bvec->bv_offset;
}

static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
{
	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;

	kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
	local_irq_restore(*flags);
}

#else
static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
{
	return page_address(bvec->bv_page) + bvec->bv_offset;
}

static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
{
	*flags = 0;
}
#endif

static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
				   unsigned long *flags)
{
	return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
}
#define __bio_kunmap_irq(buf, flags)	bvec_kunmap_irq(buf, flags)

#define bio_kmap_irq(bio, flags) \
	__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
#define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)

/*
 * Check whether this bio carries any data or not. A NULL bio is allowed.
 */
static inline int bio_has_data(struct bio *bio)
{
	return bio && bio->bi_io_vec != NULL;
}

/*
 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
 *
 * A bio_list anchors a singly-linked list of bios chained through the bi_next
 * member of the bio.  The bio_list also caches the last list member to allow
 * fast access to the tail.
 */
struct bio_list {
	struct bio *head;
	struct bio *tail;
};

static inline int bio_list_empty(const struct bio_list *bl)
{
	return bl->head == NULL;
}

static inline void bio_list_init(struct bio_list *bl)
{
	bl->head = bl->tail = NULL;
}

#define bio_list_for_each(bio, bl) \
	for (bio = (bl)->head; bio; bio = bio->bi_next)

static inline unsigned bio_list_size(const struct bio_list *bl)
{
	unsigned sz = 0;
	struct bio *bio;

	bio_list_for_each(bio, bl)
		sz++;

	return sz;
}

static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
{
	bio->bi_next = NULL;

	if (bl->tail)
		bl->tail->bi_next = bio;
	else
		bl->head = bio;

	bl->tail = bio;
}

static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
{
	bio->bi_next = bl->head;

	bl->head = bio;

	if (!bl->tail)
		bl->tail = bio;
}

static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
{
	if (!bl2->head)
		return;

	if (bl->tail)
		bl->tail->bi_next = bl2->head;
	else
		bl->head = bl2->head;

	bl->tail = bl2->tail;
}

static inline void bio_list_merge_head(struct bio_list *bl,
				       struct bio_list *bl2)
{
	if (!bl2->head)
		return;

	if (bl->head)
		bl2->tail->bi_next = bl->head;
	else
		bl->tail = bl2->tail;

	bl->head = bl2->head;
}

static inline struct bio *bio_list_peek(struct bio_list *bl)
{
	return bl->head;
}

static inline struct bio *bio_list_pop(struct bio_list *bl)
{
	struct bio *bio = bl->head;

	if (bio) {
		bl->head = bl->head->bi_next;
		if (!bl->head)
			bl->tail = NULL;

		bio->bi_next = NULL;
	}

	return bio;
}

static inline struct bio *bio_list_get(struct bio_list *bl)
{
	struct bio *bio = bl->head;

	bl->head = bl->tail = NULL;

	return bio;
}

#if defined(CONFIG_BLK_DEV_INTEGRITY)

#define bip_vec_idx(bip, idx)	(&(bip->bip_vec[(idx)]))
#define bip_vec(bip)		bip_vec_idx(bip, 0)

#define __bip_for_each_vec(bvl, bip, i, start_idx)			\
	for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx);	\
	     i < (bip)->bip_vcnt;					\
	     bvl++, i++)

#define bip_for_each_vec(bvl, bip, i)					\
	__bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)

#define bio_for_each_integrity_vec(_bvl, _bio, _iter)			\
	for_each_bio(_bio)						\
		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)

#define bio_integrity(bio) (bio->bi_integrity != NULL)

extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
extern void bio_integrity_free(struct bio *, struct bio_set *);
extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
extern int bio_integrity_enabled(struct bio *bio);
extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
extern int bio_integrity_prep(struct bio *);
extern void bio_integrity_endio(struct bio *, int);
extern void bio_integrity_advance(struct bio *, unsigned int);
extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t, struct bio_set *);
extern int bioset_integrity_create(struct bio_set *, int);
extern void bioset_integrity_free(struct bio_set *);
extern void bio_integrity_init(void);

#else /* CONFIG_BLK_DEV_INTEGRITY */

#define bio_integrity(a)		(0)
#define bioset_integrity_create(a, b)	(0)
#define bio_integrity_prep(a)		(0)
#define bio_integrity_enabled(a)	(0)
#define bio_integrity_clone(a, b, c, d)	(0)
#define bioset_integrity_free(a)	do { } while (0)
#define bio_integrity_free(a, b)	do { } while (0)
#define bio_integrity_endio(a, b)	do { } while (0)
#define bio_integrity_advance(a, b)	do { } while (0)
#define bio_integrity_trim(a, b, c)	do { } while (0)
#define bio_integrity_split(a, b, c)	do { } while (0)
#define bio_integrity_set_tag(a, b, c)	do { } while (0)
#define bio_integrity_get_tag(a, b, c)	do { } while (0)
#define bio_integrity_init(a)		do { } while (0)

#endif /* CONFIG_BLK_DEV_INTEGRITY */

#endif /* CONFIG_BLOCK */
#endif /* __LINUX_BIO_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* 2.5 block I/O model
	3	*
	4	* Copyright (C) 2001 Jens Axboe <axboe@suse.de>
	5	*
	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.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
7cc01581	12	*
1da177e4 LT	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	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-
	19	*/
	20	#ifndef __LINUX_BIO_H
	21	#define __LINUX_BIO_H
	22
	23	#include <linux/highmem.h>
	24	#include <linux/mempool.h>
22e2c507	25	#include <linux/ioprio.h>
1da177e4	26
02a5e0ac DH	27	#ifdef CONFIG_BLOCK
02a5e0ac DH	28
1da177e4 LT	29	#include <asm/io.h>
1da177e4 LT	30
7cc01581 TH	31	/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
	32	#include <linux/blk_types.h>
	33
1da177e4 LT	34	#define BIO_DEBUG
	35
	36	#ifdef BIO_DEBUG
	37	#define BIO_BUG_ON BUG_ON
	38	#else
	39	#define BIO_BUG_ON
	40	#endif
	41
d84a8477	42	#define BIO_MAX_PAGES 256
1da177e4 LT	43	#define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
	44	#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
	45
22e2c507 JA	46	/*
	47	* upper 16 bits of bi_rw define the io priority of this bio
	48	*/
	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))
	52
	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); \
	57	} while (0)
	58
1da177e4 LT	59	/*
	60	* various member access, note that bio_data should of course not be used
	61	* on highmem page vectors
	62	*/
	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)
7b6d91da CH	69	#define bio_empty_barrier(bio) \
	70	((bio->bi_rw & REQ_HARDBARRIER) && \
	71	!bio_has_data(bio) && \
	72	!(bio->bi_rw & REQ_DISCARD))
bf2de6f5	73
2e46e8b2	74	static inline unsigned int bio_cur_bytes(struct bio *bio)
bf2de6f5 JA	75	{
bf2de6f5 JA	76	if (bio->bi_vcnt)
2e46e8b2	77	return bio_iovec(bio)->bv_len;
fb2dce86	78	else /* dataless requests such as discard */
2e46e8b2	79	return bio->bi_size;
bf2de6f5 JA	80	}
	81
	82	static inline void bio_data(struct bio bio)
	83	{
	84	if (bio->bi_vcnt)
	85	return page_address(bio_page(bio)) + bio_offset(bio);
	86
	87	return NULL;
	88	}
1da177e4	89
392ddc32 JA	90	static inline int bio_has_allocated_vec(struct bio *bio)
	91	{
	92	return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
	93	}
	94
1da177e4 LT	95	/*
	96	* will die
	97	*/
	98	#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
	99	#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
	100
	101	/*
	102	* queues that have highmem support enabled may still need to revert to
	103	* PIO transfers occasionally and thus map high pages temporarily. For
	104	* permanent PIO fall back, user is probably better off disabling highmem
	105	* I/O completely on that queue (see ide-dma for example)
	106	*/
	107	#define __bio_kmap_atomic(bio, idx, kmtype) \
	108	(kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
	109	bio_iovec_idx((bio), (idx))->bv_offset)
	110
	111	#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
	112
	113	/*
	114	* merge helpers etc
	115	*/
	116
	117	#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
	118	#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
	119
f92131c3 JF	120	/* Default implementation of BIOVEC_PHYS_MERGEABLE */
	121	#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
	122	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
	123
1da177e4 LT	124	/*
	125	* allow arch override, for eg virtualized architectures (put in asm/io.h)
	126	*/
	127	#ifndef BIOVEC_PHYS_MERGEABLE
	128	#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
f92131c3	129	__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
1da177e4 LT	130	#endif
1da177e4 LT	131
1da177e4 LT	132	#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
	133	(((addr1) \| (mask)) == (((addr2) - 1) \| (mask)))
	134	#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
ae03bf63	135	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
1da177e4 LT	136	#define BIO_SEG_BOUNDARY(q, b1, b2) \
	137	BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
	138
6712ecf8	139	#define bio_io_error(bio) bio_endio((bio), -EIO)
1da177e4 LT	140
	141	/*
	142	* drivers should not use the __ version unless they _really_ want to
	143	* run through the entire bio and not just pending pieces
	144	*/
	145	#define __bio_for_each_segment(bvl, bio, i, start_idx) \
	146	for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
	147	i < (bio)->bi_vcnt; \
	148	bvl++, i++)
	149
	150	#define bio_for_each_segment(bvl, bio, i) \
	151	__bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
	152
	153	/*
	154	* get a reference to a bio, so it won't disappear. the intended use is
	155	* something like:
	156	*
	157	* bio_get(bio);
	158	* submit_bio(rw, bio);
	159	* if (bio->bi_flags ...)
	160	* do_something
	161	* bio_put(bio);
	162	*
	163	* without the bio_get(), it could potentially complete I/O before submit_bio
	164	* returns. and then bio would be freed memory when if (bio->bi_flags ...)
	165	* runs
	166	*/
	167	#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
	168
7ba1ba12 MP	169	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	170	/*
	171	* bio integrity payload
	172	*/
	173	struct bio_integrity_payload {
	174	struct bio bip_bio; / parent bio */
7ba1ba12 MP	175
	176	sector_t bip_sector; /* virtual start sector */
	177
	178	void bip_buf; / generated integrity data */
	179	bio_end_io_t bip_end_io; / saved I/O completion fn */
	180
7ba1ba12 MP	181	unsigned int bip_size;
7ba1ba12 MP	182
7878cba9	183	unsigned short bip_slab; /* slab the bip came from */
7ba1ba12 MP	184	unsigned short bip_vcnt; /* # of integrity bio_vecs */
	185	unsigned short bip_idx; /* current bip_vec index */
	186
	187	struct work_struct bip_work; /* I/O completion */
7878cba9	188	struct bio_vec bip_vec[0]; /* embedded bvec array */
7ba1ba12 MP	189	};
7ba1ba12 MP	190	#endif /* CONFIG_BLK_DEV_INTEGRITY */
1da177e4 LT	191
	192	/*
	193	* A bio_pair is used when we need to split a bio.
	194	* This can only happen for a bio that refers to just one
	195	* page of data, and in the unusual situation when the
	196	* page crosses a chunk/device boundary
	197	*
	198	* The address of the master bio is stored in bio1.bi_private
	199	* The address of the pool the pair was allocated from is stored
	200	* in bio2.bi_private
	201	*/
	202	struct bio_pair {
7ba1ba12 MP	203	struct bio bio1, bio2;
	204	struct bio_vec bv1, bv2;
	205	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	206	struct bio_integrity_payload bip1, bip2;
	207	struct bio_vec iv1, iv2;
	208	#endif
	209	atomic_t cnt;
	210	int error;
1da177e4	211	};
6feef531	212	extern struct bio_pair bio_split(struct bio bi, int first_sectors);
1da177e4 LT	213	extern void bio_pair_release(struct bio_pair *dbio);
1da177e4 LT	214
bb799ca0	215	extern struct bio_set *bioset_create(unsigned int, unsigned int);
1da177e4 LT	216	extern void bioset_free(struct bio_set *);
1da177e4 LT	217
dd0fc66f	218	extern struct bio *bio_alloc(gfp_t, int);
0a0d96b0	219	extern struct bio *bio_kmalloc(gfp_t, int);
dd0fc66f	220	extern struct bio bio_alloc_bioset(gfp_t, int, struct bio_set );
1da177e4	221	extern void bio_put(struct bio *);
3676347a	222	extern void bio_free(struct bio , struct bio_set );
1da177e4	223
6712ecf8	224	extern void bio_endio(struct bio *, int);
1da177e4 LT	225	struct request_queue;
1da177e4 LT	226	extern int bio_phys_segments(struct request_queue , struct bio );
1da177e4 LT	227
1da177e4 LT	228	extern void __bio_clone(struct bio , struct bio );
dd0fc66f	229	extern struct bio bio_clone(struct bio , gfp_t);
1da177e4 LT	230
	231	extern void bio_init(struct bio *);
	232
	233	extern int bio_add_page(struct bio , struct page , unsigned int,unsigned int);
6e68af66 MC	234	extern int bio_add_pc_page(struct request_queue , struct bio , struct page *,
6e68af66 MC	235	unsigned int, unsigned int);
1da177e4	236	extern int bio_get_nr_vecs(struct block_device *);
ad3316bf	237	extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
1da177e4	238	extern struct bio bio_map_user(struct request_queue , struct block_device *,
a3bce90e	239	unsigned long, unsigned int, int, gfp_t);
f1970baf	240	struct sg_iovec;
152e283f	241	struct rq_map_data;
f1970baf JB	242	extern struct bio bio_map_user_iov(struct request_queue ,
f1970baf JB	243	struct block_device *,
a3bce90e	244	struct sg_iovec *, int, int, gfp_t);
1da177e4	245	extern void bio_unmap_user(struct bio *);
df46b9a4	246	extern struct bio bio_map_kern(struct request_queue , void *, unsigned int,
27496a8c	247	gfp_t);
68154e90 FT	248	extern struct bio bio_copy_kern(struct request_queue , void *, unsigned int,
68154e90 FT	249	gfp_t, int);
1da177e4 LT	250	extern void bio_set_pages_dirty(struct bio *bio);
1da177e4 LT	251	extern void bio_check_pages_dirty(struct bio *bio);
2d4dc890 IL	252
	253	#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
	254	# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
	255	#endif
	256	#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
	257	extern void bio_flush_dcache_pages(struct bio *bi);
	258	#else
	259	static inline void bio_flush_dcache_pages(struct bio *bi)
	260	{
	261	}
	262	#endif
	263
152e283f FT	264	extern struct bio bio_copy_user(struct request_queue , struct rq_map_data *,
	265	unsigned long, unsigned int, int, gfp_t);
	266	extern struct bio bio_copy_user_iov(struct request_queue ,
	267	struct rq_map_data , struct sg_iovec ,
a3bce90e	268	int, int, gfp_t);
1da177e4 LT	269	extern int bio_uncopy_user(struct bio *);
1da177e4 LT	270	void zero_fill_bio(struct bio *bio);
51d654e1	271	extern struct bio_vec bvec_alloc_bs(gfp_t, int, unsigned long , struct bio_set *);
bb799ca0	272	extern void bvec_free_bs(struct bio_set , struct bio_vec , unsigned int);
7ba1ba12	273	extern unsigned int bvec_nr_vecs(unsigned short idx);
51d654e1	274
c7c22e4d JA	275	/*
	276	* Allow queuer to specify a completion CPU for this bio
	277	*/
	278	static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
	279	{
	280	bio->bi_comp_cpu = cpu;
	281	}
	282
51d654e1 MP	283	/*
	284	* bio_set is used to allow other portions of the IO system to
	285	* allocate their own private memory pools for bio and iovec structures.
	286	* These memory pools in turn all allocate from the bio_slab
	287	* and the bvec_slabs[].
	288	*/
	289	#define BIO_POOL_SIZE 2
	290	#define BIOVEC_NR_POOLS 6
7ff9345f	291	#define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
51d654e1 MP	292
51d654e1 MP	293	struct bio_set {
1b434498	294	struct kmem_cache *bio_slab;
bb799ca0 JA	295	unsigned int front_pad;
bb799ca0 JA	296
51d654e1	297	mempool_t *bio_pool;
7878cba9 MP	298	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	299	mempool_t *bio_integrity_pool;
	300	#endif
7ff9345f	301	mempool_t *bvec_pool;
51d654e1 MP	302	};
	303
	304	struct biovec_slab {
	305	int nr_vecs;
	306	char *name;
	307	struct kmem_cache *slab;
	308	};
	309
	310	extern struct bio_set *fs_bio_set;
bb799ca0	311	extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
51d654e1 MP	312
	313	/*
	314	* a small number of entries is fine, not going to be performance critical.
	315	* basically we just need to survive
	316	*/
	317	#define BIO_SPLIT_ENTRIES 2
1da177e4 LT	318
	319	#ifdef CONFIG_HIGHMEM
	320	/*
20b636bf AB	321	* remember never ever reenable interrupts between a bvec_kmap_irq and
20b636bf AB	322	* bvec_kunmap_irq!
1da177e4	323	*/
4f570f99	324	static inline char bvec_kmap_irq(struct bio_vec bvec, unsigned long *flags)
1da177e4 LT	325	{
	326	unsigned long addr;
	327
	328	/*
	329	* might not be a highmem page, but the preempt/irq count
	330	* balancing is a lot nicer this way
	331	*/
	332	local_irq_save(*flags);
	333	addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
	334
	335	BUG_ON(addr & ~PAGE_MASK);
	336
	337	return (char *) addr + bvec->bv_offset;
	338	}
	339
4f570f99	340	static inline void bvec_kunmap_irq(char buffer, unsigned long flags)
1da177e4 LT	341	{
	342	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
	343
	344	kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
	345	local_irq_restore(*flags);
	346	}
	347
	348	#else
11a691be GU	349	static inline char bvec_kmap_irq(struct bio_vec bvec, unsigned long *flags)
	350	{
	351	return page_address(bvec->bv_page) + bvec->bv_offset;
	352	}
	353
	354	static inline void bvec_kunmap_irq(char buffer, unsigned long flags)
	355	{
	356	*flags = 0;
	357	}
1da177e4 LT	358	#endif
1da177e4 LT	359
c2d08dad	360	static inline char __bio_kmap_irq(struct bio bio, unsigned short idx,
1da177e4 LT	361	unsigned long *flags)
	362	{
	363	return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
	364	}
	365	#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
	366
	367	#define bio_kmap_irq(bio, flags) \
	368	__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
	369	#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
	370
7a67f63b JA	371	/*
	372	* Check whether this bio carries any data or not. A NULL bio is allowed.
	373	*/
	374	static inline int bio_has_data(struct bio *bio)
	375	{
	376	return bio && bio->bi_io_vec != NULL;
	377	}
	378
8f3d8ba2	379	/*
e686307f	380	* BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
8f3d8ba2 CH	381	*
	382	* A bio_list anchors a singly-linked list of bios chained through the bi_next
	383	* member of the bio. The bio_list also caches the last list member to allow
	384	* fast access to the tail.
	385	*/
	386	struct bio_list {
	387	struct bio *head;
	388	struct bio *tail;
	389	};
	390
	391	static inline int bio_list_empty(const struct bio_list *bl)
	392	{
	393	return bl->head == NULL;
	394	}
	395
	396	static inline void bio_list_init(struct bio_list *bl)
	397	{
	398	bl->head = bl->tail = NULL;
	399	}
	400
	401	#define bio_list_for_each(bio, bl) \
	402	for (bio = (bl)->head; bio; bio = bio->bi_next)
	403
	404	static inline unsigned bio_list_size(const struct bio_list *bl)
	405	{
	406	unsigned sz = 0;
	407	struct bio *bio;
	408
	409	bio_list_for_each(bio, bl)
	410	sz++;
	411
	412	return sz;
	413	}
	414
	415	static inline void bio_list_add(struct bio_list bl, struct bio bio)
	416	{
	417	bio->bi_next = NULL;
	418
	419	if (bl->tail)
	420	bl->tail->bi_next = bio;
	421	else
	422	bl->head = bio;
	423
	424	bl->tail = bio;
	425	}
	426
	427	static inline void bio_list_add_head(struct bio_list bl, struct bio bio)
	428	{
	429	bio->bi_next = bl->head;
	430
	431	bl->head = bio;
	432
	433	if (!bl->tail)
	434	bl->tail = bio;
	435	}
	436
	437	static inline void bio_list_merge(struct bio_list bl, struct bio_list bl2)
	438	{
	439	if (!bl2->head)
	440	return;
	441
	442	if (bl->tail)
	443	bl->tail->bi_next = bl2->head;
	444	else
445	bl->head = bl2->head;
446
447	bl->tail = bl2->tail;
448	}
449
450	static inline void bio_list_merge_head(struct bio_list *bl,
451	struct bio_list *bl2)
452	{
453	if (!bl2->head)
454	return;
455
456	if (bl->head)
457	bl2->tail->bi_next = bl->head;
458	else
459	bl->tail = bl2->tail;
460
461	bl->head = bl2->head;
462	}
463
13685a16 GU	464	static inline struct bio bio_list_peek(struct bio_list bl)
	465	{
	466	return bl->head;
	467	}
	468
8f3d8ba2 CH	469	static inline struct bio bio_list_pop(struct bio_list bl)
	470	{
	471	struct bio *bio = bl->head;
	472
	473	if (bio) {
	474	bl->head = bl->head->bi_next;
	475	if (!bl->head)
	476	bl->tail = NULL;
	477
	478	bio->bi_next = NULL;
	479	}
	480
	481	return bio;
	482	}
	483
	484	static inline struct bio bio_list_get(struct bio_list bl)
	485	{
	486	struct bio *bio = bl->head;
	487
	488	bl->head = bl->tail = NULL;
	489
	490	return bio;
	491	}
	492
7ba1ba12 MP	493	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	494
	495	#define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
	496	#define bip_vec(bip) bip_vec_idx(bip, 0)
	497
	498	#define __bip_for_each_vec(bvl, bip, i, start_idx) \
	499	for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
	500	i < (bip)->bip_vcnt; \
	501	bvl++, i++)
	502
	503	#define bip_for_each_vec(bvl, bip, i) \
	504	__bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
	505
13f05c8d MP	506	#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
	507	for_each_bio(_bio) \
	508	bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
	509
8deaf721	510	#define bio_integrity(bio) (bio->bi_integrity != NULL)
7ba1ba12	511
7878cba9	512	extern struct bio_integrity_payload bio_integrity_alloc_bioset(struct bio , gfp_t, unsigned int, struct bio_set *);
7ba1ba12	513	extern struct bio_integrity_payload bio_integrity_alloc(struct bio , gfp_t, unsigned int);
7878cba9	514	extern void bio_integrity_free(struct bio , struct bio_set );
7ba1ba12 MP	515	extern int bio_integrity_add_page(struct bio , struct page , unsigned int, unsigned int);
	516	extern int bio_integrity_enabled(struct bio *bio);
	517	extern int bio_integrity_set_tag(struct bio , void , unsigned int);
	518	extern int bio_integrity_get_tag(struct bio , void , unsigned int);
	519	extern int bio_integrity_prep(struct bio *);
	520	extern void bio_integrity_endio(struct bio *, int);
	521	extern void bio_integrity_advance(struct bio *, unsigned int);
	522	extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
	523	extern void bio_integrity_split(struct bio , struct bio_pair , int);
7878cba9 MP	524	extern int bio_integrity_clone(struct bio , struct bio , gfp_t, struct bio_set *);
	525	extern int bioset_integrity_create(struct bio_set *, int);
	526	extern void bioset_integrity_free(struct bio_set *);
	527	extern void bio_integrity_init(void);
7ba1ba12 MP	528
	529	#else /* CONFIG_BLK_DEV_INTEGRITY */
	530
	531	#define bio_integrity(a) (0)
7878cba9	532	#define bioset_integrity_create(a, b) (0)
7ba1ba12 MP	533	#define bio_integrity_prep(a) (0)
7ba1ba12 MP	534	#define bio_integrity_enabled(a) (0)
7878cba9 MP	535	#define bio_integrity_clone(a, b, c, d) (0)
	536	#define bioset_integrity_free(a) do { } while (0)
	537	#define bio_integrity_free(a, b) do { } while (0)
7ba1ba12 MP	538	#define bio_integrity_endio(a, b) do { } while (0)
	539	#define bio_integrity_advance(a, b) do { } while (0)
	540	#define bio_integrity_trim(a, b, c) do { } while (0)
	541	#define bio_integrity_split(a, b, c) do { } while (0)
	542	#define bio_integrity_set_tag(a, b, c) do { } while (0)
	543	#define bio_integrity_get_tag(a, b, c) do { } while (0)
7878cba9	544	#define bio_integrity_init(a) do { } while (0)
7ba1ba12 MP	545
	546	#endif /* CONFIG_BLK_DEV_INTEGRITY */
	547
02a5e0ac	548	#endif /* CONFIG_BLOCK */
1da177e4	549	#endif /* __LINUX_BIO_H */