[linux.git] / block / blk.h

#ifndef BLK_INTERNAL_H
#define BLK_INTERNAL_H

/* Amount of time in which a process may batch requests */
#define BLK_BATCH_TIME	(HZ/50UL)

/* Number of requests a "batching" process may submit */
#define BLK_BATCH_REQ	32

extern struct kmem_cache *blk_requestq_cachep;
extern struct kobj_type blk_queue_ktype;

void init_request_from_bio(struct request *req, struct bio *bio);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
			struct bio *bio);
void __blk_queue_free_tags(struct request_queue *q);

void blk_unplug_work(struct work_struct *work);
void blk_unplug_timeout(unsigned long data);
void blk_rq_timed_out_timer(unsigned long data);
void blk_delete_timer(struct request *);
void blk_add_timer(struct request *);
void __generic_unplug_device(struct request_queue *);

/*
 * Internal atomic flags for request handling
 */
enum rq_atomic_flags {
	REQ_ATOM_COMPLETE = 0,
};

/*
 * EH timer and IO completion will both attempt to 'grab' the request, make
 * sure that only one of them suceeds
 */
static inline int blk_mark_rq_complete(struct request *rq)
{
	return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
}

static inline void blk_clear_rq_complete(struct request *rq)
{
	clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
}

#ifdef CONFIG_FAIL_IO_TIMEOUT
int blk_should_fake_timeout(struct request_queue *);
ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
ssize_t part_timeout_store(struct device *, struct device_attribute *,
				const char *, size_t);
#else
static inline int blk_should_fake_timeout(struct request_queue *q)
{
	return 0;
}
#endif

struct io_context *current_io_context(gfp_t gfp_flags, int node);

int ll_back_merge_fn(struct request_queue *q, struct request *req,
		     struct bio *bio);
int ll_front_merge_fn(struct request_queue *q, struct request *req, 
		      struct bio *bio);
int attempt_back_merge(struct request_queue *q, struct request *rq);
int attempt_front_merge(struct request_queue *q, struct request *rq);
void blk_recalc_rq_segments(struct request *rq);
void blk_recalc_rq_sectors(struct request *rq, int nsect);

void blk_queue_congestion_threshold(struct request_queue *q);

int blk_dev_init(void);

void elv_quiesce_start(struct request_queue *q);
void elv_quiesce_end(struct request_queue *q);


/*
 * Return the threshold (number of used requests) at which the queue is
 * considered to be congested.  It include a little hysteresis to keep the
 * context switch rate down.
 */
static inline int queue_congestion_on_threshold(struct request_queue *q)
{
	return q->nr_congestion_on;
}

/*
 * The threshold at which a queue is considered to be uncongested
 */
static inline int queue_congestion_off_threshold(struct request_queue *q)
{
	return q->nr_congestion_off;
}

#if defined(CONFIG_BLK_DEV_INTEGRITY)

#define rq_for_each_integrity_segment(bvl, _rq, _iter)		\
	__rq_for_each_bio(_iter.bio, _rq)			\
		bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)

#endif /* BLK_DEV_INTEGRITY */

static inline int blk_cpu_to_group(int cpu)
{
#ifdef CONFIG_SCHED_MC
	const struct cpumask *mask = cpu_coregroup_mask(cpu);
	return cpumask_first(mask);
#elif defined(CONFIG_SCHED_SMT)
	return cpumask_first(topology_thread_cpumask(cpu));
#else
	return cpu;
#endif
}

static inline int blk_do_io_stat(struct request *rq)
{
	struct gendisk *disk = rq->rq_disk;

	if (!disk || !disk->queue)
		return 0;

	return blk_queue_io_stat(disk->queue) && (rq->cmd_flags & REQ_ELVPRIV);
}

#endif
Commit	Line	Data
8324aa91 JA	1	#ifndef BLK_INTERNAL_H
	2	#define BLK_INTERNAL_H
	3
86db1e29 JA	4	/* Amount of time in which a process may batch requests */
	5	#define BLK_BATCH_TIME (HZ/50UL)
	6
	7	/* Number of requests a "batching" process may submit */
	8	#define BLK_BATCH_REQ 32
	9
8324aa91 JA	10	extern struct kmem_cache *blk_requestq_cachep;
	11	extern struct kobj_type blk_queue_ktype;
	12
86db1e29 JA	13	void init_request_from_bio(struct request req, struct bio bio);
	14	void blk_rq_bio_prep(struct request_queue q, struct request rq,
	15	struct bio *bio);
8324aa91 JA	16	void __blk_queue_free_tags(struct request_queue *q);
8324aa91 JA	17
86db1e29 JA	18	void blk_unplug_work(struct work_struct *work);
86db1e29 JA	19	void blk_unplug_timeout(unsigned long data);
242f9dcb JA	20	void blk_rq_timed_out_timer(unsigned long data);
	21	void blk_delete_timer(struct request *);
	22	void blk_add_timer(struct request *);
f73e2d13	23	void __generic_unplug_device(struct request_queue *);
242f9dcb JA	24
	25	/*
	26	* Internal atomic flags for request handling
	27	*/
	28	enum rq_atomic_flags {
	29	REQ_ATOM_COMPLETE = 0,
	30	};
	31
	32	/*
	33	* EH timer and IO completion will both attempt to 'grab' the request, make
	34	* sure that only one of them suceeds
	35	*/
	36	static inline int blk_mark_rq_complete(struct request *rq)
	37	{
	38	return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
	39	}
	40
	41	static inline void blk_clear_rq_complete(struct request *rq)
	42	{
	43	clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
	44	}
86db1e29	45
581d4e28 JA	46	#ifdef CONFIG_FAIL_IO_TIMEOUT
	47	int blk_should_fake_timeout(struct request_queue *);
	48	ssize_t part_timeout_show(struct device , struct device_attribute , char *);
	49	ssize_t part_timeout_store(struct device , struct device_attribute ,
	50	const char *, size_t);
	51	#else
	52	static inline int blk_should_fake_timeout(struct request_queue *q)
	53	{
	54	return 0;
	55	}
	56	#endif
	57
86db1e29 JA	58	struct io_context *current_io_context(gfp_t gfp_flags, int node);
86db1e29 JA	59
d6d48196 JA	60	int ll_back_merge_fn(struct request_queue q, struct request req,
	61	struct bio *bio);
	62	int ll_front_merge_fn(struct request_queue q, struct request req,
	63	struct bio *bio);
	64	int attempt_back_merge(struct request_queue q, struct request rq);
	65	int attempt_front_merge(struct request_queue q, struct request rq);
	66	void blk_recalc_rq_segments(struct request *rq);
	67	void blk_recalc_rq_sectors(struct request *rq, int nsect);
	68
8324aa91 JA	69	void blk_queue_congestion_threshold(struct request_queue *q);
8324aa91 JA	70
ff88972c AB	71	int blk_dev_init(void);
ff88972c AB	72
f600abe2 JA	73	void elv_quiesce_start(struct request_queue *q);
f600abe2 JA	74	void elv_quiesce_end(struct request_queue *q);
6c7e8cee JA	75
6c7e8cee JA	76
8324aa91 JA	77	/*
	78	* Return the threshold (number of used requests) at which the queue is
	79	* considered to be congested. It include a little hysteresis to keep the
	80	* context switch rate down.
	81	*/
	82	static inline int queue_congestion_on_threshold(struct request_queue *q)
	83	{
	84	return q->nr_congestion_on;
	85	}
	86
	87	/*
	88	* The threshold at which a queue is considered to be uncongested
	89	*/
	90	static inline int queue_congestion_off_threshold(struct request_queue *q)
	91	{
	92	return q->nr_congestion_off;
	93	}
	94
7ba1ba12 MP	95	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	96
	97	#define rq_for_each_integrity_segment(bvl, _rq, _iter) \
	98	__rq_for_each_bio(_iter.bio, _rq) \
	99	bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
	100
	101	#endif /* BLK_DEV_INTEGRITY */
	102
c7c22e4d JA	103	static inline int blk_cpu_to_group(int cpu)
	104	{
	105	#ifdef CONFIG_SCHED_MC
be4d638c RR	106	const struct cpumask *mask = cpu_coregroup_mask(cpu);
be4d638c RR	107	return cpumask_first(mask);
c7c22e4d	108	#elif defined(CONFIG_SCHED_SMT)
c69fc56d	109	return cpumask_first(topology_thread_cpumask(cpu));
c7c22e4d JA	110	#else
	111	return cpu;
	112	#endif
	113	}
	114
26308eab	115	static inline int blk_do_io_stat(struct request *rq)
fb8ec18c	116	{
26308eab	117	struct gendisk *disk = rq->rq_disk;
fb8ec18c	118
26308eab JM	119	if (!disk \|\| !disk->queue)
	120	return 0;
	121
	122	return blk_queue_io_stat(disk->queue) && (rq->cmd_flags & REQ_ELVPRIV);
fb8ec18c JA	123	}
fb8ec18c JA	124
8324aa91	125	#endif