[mirror_ubuntu-artful-kernel.git] / include / linux / blk_types.h

/*
 * Block data types and constants.  Directly include this file only to
 * break include dependency loop.
 */
#ifndef __LINUX_BLK_TYPES_H
#define __LINUX_BLK_TYPES_H

#include <linux/types.h>
#include <linux/bvec.h>

struct bio_set;
struct bio;
struct bio_integrity_payload;
struct page;
struct block_device;
struct io_context;
struct cgroup_subsys_state;
typedef void (bio_end_io_t) (struct bio *);

#ifdef CONFIG_BLOCK
/*
 * main unit of I/O for the block layer and lower layers (ie drivers and
 * stacking drivers)
 */
struct bio {
	struct bio		*bi_next;	/* request queue link */
	struct block_device	*bi_bdev;
	int			bi_error;
	unsigned int		bi_opf;		/* bottom bits req flags,
						 * top bits REQ_OP. Use
						 * accessors.
						 */
	unsigned short		bi_flags;	/* status, command, etc */
	unsigned short		bi_ioprio;

	struct bvec_iter	bi_iter;

	/* Number of segments in this BIO after
	 * physical address coalescing is performed.
	 */
	unsigned int		bi_phys_segments;

	/*
	 * To keep track of the max segment size, we account for the
	 * sizes of the first and last mergeable segments in this bio.
	 */
	unsigned int		bi_seg_front_size;
	unsigned int		bi_seg_back_size;

	atomic_t		__bi_remaining;

	bio_end_io_t		*bi_end_io;

	void			*bi_private;
#ifdef CONFIG_BLK_CGROUP
	/*
	 * Optional ioc and css associated with this bio.  Put on bio
	 * release.  Read comment on top of bio_associate_current().
	 */
	struct io_context	*bi_ioc;
	struct cgroup_subsys_state *bi_css;
#endif
	union {
#if defined(CONFIG_BLK_DEV_INTEGRITY)
		struct bio_integrity_payload *bi_integrity; /* data integrity */
#endif
	};

	unsigned short		bi_vcnt;	/* how many bio_vec's */

	/*
	 * Everything starting with bi_max_vecs will be preserved by bio_reset()
	 */

	unsigned short		bi_max_vecs;	/* max bvl_vecs we can hold */

	atomic_t		__bi_cnt;	/* pin count */

	struct bio_vec		*bi_io_vec;	/* the actual vec list */

	struct bio_set		*bi_pool;

	/*
	 * We can inline a number of vecs at the end of the bio, to avoid
	 * double allocations for a small number of bio_vecs. This member
	 * MUST obviously be kept at the very end of the bio.
	 */
	struct bio_vec		bi_inline_vecs[0];
};

#define BIO_RESET_BYTES		offsetof(struct bio, bi_max_vecs)

/*
 * bio flags
 */
#define BIO_SEG_VALID	1	/* bi_phys_segments valid */
#define BIO_CLONED	2	/* doesn't own data */
#define BIO_BOUNCED	3	/* bio is a bounce bio */
#define BIO_USER_MAPPED 4	/* contains user pages */
#define BIO_NULL_MAPPED 5	/* contains invalid user pages */
#define BIO_QUIET	6	/* Make BIO Quiet */
#define BIO_CHAIN	7	/* chained bio, ->bi_remaining in effect */
#define BIO_REFFED	8	/* bio has elevated ->bi_cnt */
#define BIO_THROTTLED	9	/* This bio has already been subjected to
				 * throttling rules. Don't do it again. */

/*
 * Flags starting here get preserved by bio_reset() - this includes
 * BVEC_POOL_IDX()
 */
#define BIO_RESET_BITS	10

/*
 * We support 6 different bvec pools, the last one is magic in that it
 * is backed by a mempool.
 */
#define BVEC_POOL_NR		6
#define BVEC_POOL_MAX		(BVEC_POOL_NR - 1)

/*
 * Top 4 bits of bio flags indicate the pool the bvecs came from.  We add
 * 1 to the actual index so that 0 indicates that there are no bvecs to be
 * freed.
 */
#define BVEC_POOL_BITS		(4)
#define BVEC_POOL_OFFSET	(16 - BVEC_POOL_BITS)
#define BVEC_POOL_IDX(bio)	((bio)->bi_flags >> BVEC_POOL_OFFSET)

#endif /* CONFIG_BLOCK */

/*
 * Operations and flags common to the bio and request structures.
 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
 */
#define REQ_OP_BITS	8
#define REQ_OP_MASK	((1 << REQ_OP_BITS) - 1)
#define REQ_FLAG_BITS	24

enum req_opf {
	REQ_OP_READ,
	REQ_OP_WRITE,
	REQ_OP_DISCARD,		/* request to discard sectors */
	REQ_OP_SECURE_ERASE,	/* request to securely erase sectors */
	REQ_OP_WRITE_SAME,	/* write same block many times */
	REQ_OP_FLUSH,		/* request for cache flush */
	REQ_OP_ZONE_REPORT,	/* Get zone information */
	REQ_OP_ZONE_RESET,	/* Reset a zone write pointer */

	REQ_OP_LAST,
};

enum req_flag_bits {
	__REQ_FAILFAST_DEV =	/* no driver retries of device errors */
		REQ_OP_BITS,
	__REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
	__REQ_FAILFAST_DRIVER,	/* no driver retries of driver errors */
	__REQ_SYNC,		/* request is sync (sync write or read) */
	__REQ_META,		/* metadata io request */
	__REQ_PRIO,		/* boost priority in cfq */
	__REQ_NOMERGE,		/* don't touch this for merging */
	__REQ_NOIDLE,		/* don't anticipate more IO after this one */
	__REQ_INTEGRITY,	/* I/O includes block integrity payload */
	__REQ_FUA,		/* forced unit access */
	__REQ_PREFLUSH,		/* request for cache flush */
	__REQ_RAHEAD,		/* read ahead, can fail anytime */
	__REQ_NR_BITS,		/* stops here */
};

#define REQ_FAILFAST_DEV	(1ULL << __REQ_FAILFAST_DEV)
#define REQ_FAILFAST_TRANSPORT	(1ULL << __REQ_FAILFAST_TRANSPORT)
#define REQ_FAILFAST_DRIVER	(1ULL << __REQ_FAILFAST_DRIVER)
#define REQ_SYNC		(1ULL << __REQ_SYNC)
#define REQ_META		(1ULL << __REQ_META)
#define REQ_PRIO		(1ULL << __REQ_PRIO)
#define REQ_NOMERGE		(1ULL << __REQ_NOMERGE)
#define REQ_NOIDLE		(1ULL << __REQ_NOIDLE)
#define REQ_INTEGRITY		(1ULL << __REQ_INTEGRITY)
#define REQ_FUA			(1ULL << __REQ_FUA)
#define REQ_PREFLUSH		(1ULL << __REQ_PREFLUSH)
#define REQ_RAHEAD		(1ULL << __REQ_RAHEAD)

#define REQ_FAILFAST_MASK \
	(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)

#define REQ_NOMERGE_FLAGS \
	(REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)

#define bio_op(bio) \
	((bio)->bi_opf & REQ_OP_MASK)
#define req_op(req) \
	((req)->cmd_flags & REQ_OP_MASK)

/* obsolete, don't use in new code */
#define bio_set_op_attrs(bio, op, op_flags) \
	((bio)->bi_opf |= (op | op_flags))

static inline bool op_is_sync(unsigned int op)
{
	return (op & REQ_OP_MASK) == REQ_OP_READ || (op & REQ_SYNC);
}

typedef unsigned int blk_qc_t;
#define BLK_QC_T_NONE	-1U
#define BLK_QC_T_SHIFT	16

static inline bool blk_qc_t_valid(blk_qc_t cookie)
{
	return cookie != BLK_QC_T_NONE;
}

static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num)
{
	return tag | (queue_num << BLK_QC_T_SHIFT);
}

static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
{
	return cookie >> BLK_QC_T_SHIFT;
}

static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
{
	return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
}

#endif /* __LINUX_BLK_TYPES_H */
Commit	Line	Data
7cc01581 TH	1	/*
	2	* Block data types and constants. Directly include this file only to
	3	* break include dependency loop.
	4	*/
	5	#ifndef __LINUX_BLK_TYPES_H
	6	#define __LINUX_BLK_TYPES_H
	7
7cc01581	8	#include <linux/types.h>
0781e79e	9	#include <linux/bvec.h>
7cc01581 TH	10
	11	struct bio_set;
	12	struct bio;
	13	struct bio_integrity_payload;
	14	struct page;
	15	struct block_device;
852c788f TH	16	struct io_context;
852c788f TH	17	struct cgroup_subsys_state;
4246a0b6	18	typedef void (bio_end_io_t) (struct bio *);
7cc01581	19
62a8067a	20	#ifdef CONFIG_BLOCK
7cc01581 TH	21	/*
	22	* main unit of I/O for the block layer and lower layers (ie drivers and
	23	* stacking drivers)
	24	*/
	25	struct bio {
7cc01581 TH	26	struct bio bi_next; / request queue link */
7cc01581 TH	27	struct block_device *bi_bdev;
2c68f6dc	28	int bi_error;
1eff9d32 JA	29	unsigned int bi_opf; /* bottom bits req flags,
	30	* top bits REQ_OP. Use
	31	* accessors.
4e1b2d52	32	*/
c0acf12a	33	unsigned short bi_flags; /* status, command, etc */
43b62ce3	34	unsigned short bi_ioprio;
7cc01581	35
4f024f37	36	struct bvec_iter bi_iter;
7cc01581 TH	37
	38	/* Number of segments in this BIO after
	39	* physical address coalescing is performed.
	40	*/
	41	unsigned int bi_phys_segments;
	42
7cc01581 TH	43	/*
	44	* To keep track of the max segment size, we account for the
	45	* sizes of the first and last mergeable segments in this bio.
	46	*/
	47	unsigned int bi_seg_front_size;
	48	unsigned int bi_seg_back_size;
	49
c4cf5261	50	atomic_t __bi_remaining;
196d38bc	51
7cc01581 TH	52	bio_end_io_t *bi_end_io;
	53
	54	void *bi_private;
852c788f TH	55	#ifdef CONFIG_BLK_CGROUP
	56	/*
	57	* Optional ioc and css associated with this bio. Put on bio
	58	* release. Read comment on top of bio_associate_current().
	59	*/
	60	struct io_context *bi_ioc;
	61	struct cgroup_subsys_state *bi_css;
	62	#endif
180b2f95	63	union {
7cc01581	64	#if defined(CONFIG_BLK_DEV_INTEGRITY)
180b2f95	65	struct bio_integrity_payload bi_integrity; / data integrity */
7cc01581	66	#endif
180b2f95	67	};
7cc01581	68
4f024f37 KO	69	unsigned short bi_vcnt; /* how many bio_vec's */
4f024f37 KO	70
f44b48c7 KO	71	/*
	72	* Everything starting with bi_max_vecs will be preserved by bio_reset()
	73	*/
	74
4f024f37	75	unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
f44b48c7	76
dac56212	77	atomic_t __bi_cnt; /* pin count */
f44b48c7 KO	78
	79	struct bio_vec bi_io_vec; / the actual vec list */
	80
395c72a7 KO	81	struct bio_set *bi_pool;
395c72a7 KO	82
7cc01581 TH	83	/*
	84	* We can inline a number of vecs at the end of the bio, to avoid
	85	* double allocations for a small number of bio_vecs. This member
	86	* MUST obviously be kept at the very end of the bio.
	87	*/
	88	struct bio_vec bi_inline_vecs[0];
	89	};
	90
f44b48c7 KO	91	#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
f44b48c7 KO	92
7cc01581 TH	93	/*
	94	* bio flags
	95	*/
b2dbe0a6 JA	96	#define BIO_SEG_VALID 1 /* bi_phys_segments valid */
	97	#define BIO_CLONED 2 /* doesn't own data */
	98	#define BIO_BOUNCED 3 /* bio is a bounce bio */
	99	#define BIO_USER_MAPPED 4 /* contains user pages */
	100	#define BIO_NULL_MAPPED 5 /* contains invalid user pages */
	101	#define BIO_QUIET 6 /* Make BIO Quiet */
a3ad0a9d JK	102	#define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
a3ad0a9d JK	103	#define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
8d2bbd4c CH	104	#define BIO_THROTTLED 9 /* This bio has already been subjected to
8d2bbd4c CH	105	* throttling rules. Don't do it again. */
f44b48c7 KO	106
	107	/*
	108	* Flags starting here get preserved by bio_reset() - this includes
ed996a52	109	* BVEC_POOL_IDX()
f44b48c7	110	*/
c0acf12a	111	#define BIO_RESET_BITS 10
f44b48c7	112
7cc01581	113	/*
ed996a52 CH	114	* We support 6 different bvec pools, the last one is magic in that it
ed996a52 CH	115	* is backed by a mempool.
7cc01581	116	*/
ed996a52 CH	117	#define BVEC_POOL_NR 6
	118	#define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
	119
	120	/*
	121	* Top 4 bits of bio flags indicate the pool the bvecs came from. We add
	122	* 1 to the actual index so that 0 indicates that there are no bvecs to be
	123	* freed.
	124	*/
	125	#define BVEC_POOL_BITS (4)
c0acf12a	126	#define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
ed996a52	127	#define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
7cc01581	128
de75d60d JA	129	#endif /* CONFIG_BLOCK */
de75d60d JA	130
7cc01581	131	/*
ef295ecf CH	132	* Operations and flags common to the bio and request structures.
ef295ecf CH	133	* We use 8 bits for encoding the operation, and the remaining 24 for flags.
7cc01581	134	*/
ef295ecf CH	135	#define REQ_OP_BITS 8
	136	#define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
	137	#define REQ_FLAG_BITS 24
	138
	139	enum req_opf {
	140	REQ_OP_READ,
	141	REQ_OP_WRITE,
	142	REQ_OP_DISCARD, /* request to discard sectors */
	143	REQ_OP_SECURE_ERASE, /* request to securely erase sectors */
	144	REQ_OP_WRITE_SAME, /* write same block many times */
	145	REQ_OP_FLUSH, /* request for cache flush */
	146	REQ_OP_ZONE_REPORT, /* Get zone information */
	147	REQ_OP_ZONE_RESET, /* Reset a zone write pointer */
	148
	149	REQ_OP_LAST,
	150	};
	151
	152	enum req_flag_bits {
	153	__REQ_FAILFAST_DEV = /* no driver retries of device errors */
	154	REQ_OP_BITS,
7cc01581 TH	155	__REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
7cc01581 TH	156	__REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
7cc01581 TH	157	__REQ_SYNC, /* request is sync (sync write or read) */
7cc01581 TH	158	__REQ_META, /* metadata io request */
65299a3b	159	__REQ_PRIO, /* boost priority in cfq */
bd1c1c21	160	__REQ_NOMERGE, /* don't touch this for merging */
7cc01581	161	__REQ_NOIDLE, /* don't anticipate more IO after this one */
180b2f95	162	__REQ_INTEGRITY, /* I/O includes block integrity payload */
8e4bf844	163	__REQ_FUA, /* forced unit access */
28a8f0d3	164	__REQ_PREFLUSH, /* request for cache flush */
188bd2b1	165	__REQ_RAHEAD, /* read ahead, can fail anytime */
7cc01581 TH	166	__REQ_NR_BITS, /* stops here */
	167	};
	168
5953316d JA	169	#define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
	170	#define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
	171	#define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
	172	#define REQ_SYNC (1ULL << __REQ_SYNC)
	173	#define REQ_META (1ULL << __REQ_META)
	174	#define REQ_PRIO (1ULL << __REQ_PRIO)
ef295ecf	175	#define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
5953316d	176	#define REQ_NOIDLE (1ULL << __REQ_NOIDLE)
180b2f95	177	#define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
ef295ecf CH	178	#define REQ_FUA (1ULL << __REQ_FUA)
	179	#define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
	180	#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
7cc01581 TH	181
	182	#define REQ_FAILFAST_MASK \
	183	(REQ_FAILFAST_DEV \| REQ_FAILFAST_TRANSPORT \| REQ_FAILFAST_DRIVER)
7cc01581	184
e2a60da7	185	#define REQ_NOMERGE_FLAGS \
e8064021	186	(REQ_NOMERGE \| REQ_PREFLUSH \| REQ_FUA)
e2a60da7	187
ef295ecf CH	188	#define bio_op(bio) \
	189	((bio)->bi_opf & REQ_OP_MASK)
	190	#define req_op(req) \
	191	((req)->cmd_flags & REQ_OP_MASK)
7cc01581	192
ef295ecf CH	193	/* obsolete, don't use in new code */
	194	#define bio_set_op_attrs(bio, op, op_flags) \
	195	((bio)->bi_opf \|= (op \| op_flags))
c11f0c0b	196
ef295ecf CH	197	static inline bool op_is_sync(unsigned int op)
	198	{
	199	return (op & REQ_OP_MASK) == REQ_OP_READ \|\| (op & REQ_SYNC);
	200	}
c11f0c0b	201
dece1635 JA	202	typedef unsigned int blk_qc_t;
	203	#define BLK_QC_T_NONE -1U
	204	#define BLK_QC_T_SHIFT 16
	205
	206	static inline bool blk_qc_t_valid(blk_qc_t cookie)
	207	{
	208	return cookie != BLK_QC_T_NONE;
	209	}
	210
	211	static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num)
	212	{
	213	return tag \| (queue_num << BLK_QC_T_SHIFT);
	214	}
	215
	216	static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
	217	{
	218	return cookie >> BLK_QC_T_SHIFT;
	219	}
	220
	221	static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
	222	{
e3a7a3bf	223	return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
dece1635 JA	224	}
dece1635 JA	225
7cc01581	226	#endif /* __LINUX_BLK_TYPES_H */