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

#ifndef _LINUX_ELEVATOR_H
#define _LINUX_ELEVATOR_H

typedef int (elevator_merge_fn) (request_queue_t *, struct request **,
				 struct bio *);

typedef void (elevator_merge_req_fn) (request_queue_t *, struct request *, struct request *);

typedef void (elevator_merged_fn) (request_queue_t *, struct request *);

typedef struct request *(elevator_next_req_fn) (request_queue_t *);

typedef void (elevator_add_req_fn) (request_queue_t *, struct request *, int);
typedef int (elevator_queue_empty_fn) (request_queue_t *);
typedef void (elevator_remove_req_fn) (request_queue_t *, struct request *);
typedef void (elevator_requeue_req_fn) (request_queue_t *, struct request *);
typedef struct request *(elevator_request_list_fn) (request_queue_t *, struct request *);
typedef void (elevator_completed_req_fn) (request_queue_t *, struct request *);
typedef int (elevator_may_queue_fn) (request_queue_t *, int, struct bio *);

typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, struct bio *, int);
typedef void (elevator_put_req_fn) (request_queue_t *, struct request *);
typedef void (elevator_deactivate_req_fn) (request_queue_t *, struct request *);

typedef int (elevator_init_fn) (request_queue_t *, elevator_t *);
typedef void (elevator_exit_fn) (elevator_t *);

struct elevator_ops
{
	elevator_merge_fn *elevator_merge_fn;
	elevator_merged_fn *elevator_merged_fn;
	elevator_merge_req_fn *elevator_merge_req_fn;

	elevator_next_req_fn *elevator_next_req_fn;
	elevator_add_req_fn *elevator_add_req_fn;
	elevator_remove_req_fn *elevator_remove_req_fn;
	elevator_requeue_req_fn *elevator_requeue_req_fn;
	elevator_deactivate_req_fn *elevator_deactivate_req_fn;

	elevator_queue_empty_fn *elevator_queue_empty_fn;
	elevator_completed_req_fn *elevator_completed_req_fn;

	elevator_request_list_fn *elevator_former_req_fn;
	elevator_request_list_fn *elevator_latter_req_fn;

	elevator_set_req_fn *elevator_set_req_fn;
	elevator_put_req_fn *elevator_put_req_fn;

	elevator_may_queue_fn *elevator_may_queue_fn;

	elevator_init_fn *elevator_init_fn;
	elevator_exit_fn *elevator_exit_fn;
};

#define ELV_NAME_MAX	(16)

/*
 * identifies an elevator type, such as AS or deadline
 */
struct elevator_type
{
	struct list_head list;
	struct elevator_ops ops;
	struct elevator_type *elevator_type;
	struct kobj_type *elevator_ktype;
	char elevator_name[ELV_NAME_MAX];
	struct module *elevator_owner;
};

/*
 * each queue has an elevator_queue assoicated with it
 */
struct elevator_queue
{
	struct elevator_ops *ops;
	void *elevator_data;
	struct kobject kobj;
	struct elevator_type *elevator_type;
};

/*
 * block elevator interface
 */
extern void elv_add_request(request_queue_t *, struct request *, int, int);
extern void __elv_add_request(request_queue_t *, struct request *, int, int);
extern int elv_merge(request_queue_t *, struct request **, struct bio *);
extern void elv_merge_requests(request_queue_t *, struct request *,
			       struct request *);
extern void elv_merged_request(request_queue_t *, struct request *);
extern void elv_remove_request(request_queue_t *, struct request *);
extern void elv_requeue_request(request_queue_t *, struct request *);
extern void elv_deactivate_request(request_queue_t *, struct request *);
extern int elv_queue_empty(request_queue_t *);
extern struct request *elv_next_request(struct request_queue *q);
extern struct request *elv_former_request(request_queue_t *, struct request *);
extern struct request *elv_latter_request(request_queue_t *, struct request *);
extern int elv_register_queue(request_queue_t *q);
extern void elv_unregister_queue(request_queue_t *q);
extern int elv_may_queue(request_queue_t *, int, struct bio *);
extern void elv_completed_request(request_queue_t *, struct request *);
extern int elv_set_request(request_queue_t *, struct request *, struct bio *, int);
extern void elv_put_request(request_queue_t *, struct request *);

/*
 * io scheduler registration
 */
extern int elv_register(struct elevator_type *);
extern void elv_unregister(struct elevator_type *);

/*
 * io scheduler sysfs switching
 */
extern ssize_t elv_iosched_show(request_queue_t *, char *);
extern ssize_t elv_iosched_store(request_queue_t *, const char *, size_t);

extern int elevator_init(request_queue_t *, char *);
extern void elevator_exit(elevator_t *);
extern int elv_rq_merge_ok(struct request *, struct bio *);
extern int elv_try_merge(struct request *, struct bio *);
extern int elv_try_last_merge(request_queue_t *, struct bio *);

/*
 * Return values from elevator merger
 */
#define ELEVATOR_NO_MERGE	0
#define ELEVATOR_FRONT_MERGE	1
#define ELEVATOR_BACK_MERGE	2

/*
 * Insertion selection
 */
#define ELEVATOR_INSERT_FRONT	1
#define ELEVATOR_INSERT_BACK	2
#define ELEVATOR_INSERT_SORT	3

/*
 * return values from elevator_may_queue_fn
 */
enum {
	ELV_MQUEUE_MAY,
	ELV_MQUEUE_NO,
	ELV_MQUEUE_MUST,
};

#endif
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_ELEVATOR_H
	2	#define _LINUX_ELEVATOR_H
	3
	4	typedef int (elevator_merge_fn) (request_queue_t , struct request *,
	5	struct bio *);
	6
	7	typedef void (elevator_merge_req_fn) (request_queue_t , struct request , struct request *);
	8
	9	typedef void (elevator_merged_fn) (request_queue_t , struct request );
	10
	11	typedef struct request (elevator_next_req_fn) (request_queue_t );
	12
	13	typedef void (elevator_add_req_fn) (request_queue_t , struct request , int);
	14	typedef int (elevator_queue_empty_fn) (request_queue_t *);
	15	typedef void (elevator_remove_req_fn) (request_queue_t , struct request );
	16	typedef void (elevator_requeue_req_fn) (request_queue_t , struct request );
	17	typedef struct request (elevator_request_list_fn) (request_queue_t , struct request *);
	18	typedef void (elevator_completed_req_fn) (request_queue_t , struct request );
22e2c507	19	typedef int (elevator_may_queue_fn) (request_queue_t , int, struct bio );
1da177e4	20
22e2c507	21	typedef int (elevator_set_req_fn) (request_queue_t , struct request , struct bio *, int);
1da177e4 LT	22	typedef void (elevator_put_req_fn) (request_queue_t , struct request );
	23	typedef void (elevator_deactivate_req_fn) (request_queue_t , struct request );
	24
	25	typedef int (elevator_init_fn) (request_queue_t , elevator_t );
	26	typedef void (elevator_exit_fn) (elevator_t *);
	27
	28	struct elevator_ops
	29	{
	30	elevator_merge_fn *elevator_merge_fn;
	31	elevator_merged_fn *elevator_merged_fn;
	32	elevator_merge_req_fn *elevator_merge_req_fn;
	33
	34	elevator_next_req_fn *elevator_next_req_fn;
	35	elevator_add_req_fn *elevator_add_req_fn;
	36	elevator_remove_req_fn *elevator_remove_req_fn;
	37	elevator_requeue_req_fn *elevator_requeue_req_fn;
	38	elevator_deactivate_req_fn *elevator_deactivate_req_fn;
	39
	40	elevator_queue_empty_fn *elevator_queue_empty_fn;
	41	elevator_completed_req_fn *elevator_completed_req_fn;
	42
	43	elevator_request_list_fn *elevator_former_req_fn;
	44	elevator_request_list_fn *elevator_latter_req_fn;
	45
	46	elevator_set_req_fn *elevator_set_req_fn;
	47	elevator_put_req_fn *elevator_put_req_fn;
	48
	49	elevator_may_queue_fn *elevator_may_queue_fn;
	50
	51	elevator_init_fn *elevator_init_fn;
	52	elevator_exit_fn *elevator_exit_fn;
	53	};
	54
	55	#define ELV_NAME_MAX (16)
	56
	57	/*
	58	* identifies an elevator type, such as AS or deadline
	59	*/
	60	struct elevator_type
	61	{
	62	struct list_head list;
	63	struct elevator_ops ops;
	64	struct elevator_type *elevator_type;
	65	struct kobj_type *elevator_ktype;
	66	char elevator_name[ELV_NAME_MAX];
	67	struct module *elevator_owner;
	68	};
	69
	70	/*
	71	* each queue has an elevator_queue assoicated with it
	72	*/
	73	struct elevator_queue
	74	{
	75	struct elevator_ops *ops;
	76	void *elevator_data;
	77	struct kobject kobj;
	78	struct elevator_type *elevator_type;
	79	};
	80
	81	/*
	82	* block elevator interface
	83	*/
	84	extern void elv_add_request(request_queue_t , struct request , int, int);
	85	extern void __elv_add_request(request_queue_t , struct request , int, int);
86	extern int elv_merge(request_queue_t , struct request , struct bio );
87	extern void elv_merge_requests(request_queue_t , struct request ,
88	struct request *);
89	extern void elv_merged_request(request_queue_t , struct request );
90	extern void elv_remove_request(request_queue_t , struct request );
91	extern void elv_requeue_request(request_queue_t , struct request );
92	extern void elv_deactivate_request(request_queue_t , struct request );
93	extern int elv_queue_empty(request_queue_t *);
94	extern struct request elv_next_request(struct request_queue q);
95	extern struct request elv_former_request(request_queue_t , struct request *);
96	extern struct request elv_latter_request(request_queue_t , struct request *);
97	extern int elv_register_queue(request_queue_t *q);
98	extern void elv_unregister_queue(request_queue_t *q);
22e2c507	99	extern int elv_may_queue(request_queue_t , int, struct bio );
1da177e4	100	extern void elv_completed_request(request_queue_t , struct request );
22e2c507	101	extern int elv_set_request(request_queue_t , struct request , struct bio *, int);
1da177e4 LT	102	extern void elv_put_request(request_queue_t , struct request );
	103
	104	/*
	105	* io scheduler registration
	106	*/
	107	extern int elv_register(struct elevator_type *);
	108	extern void elv_unregister(struct elevator_type *);
	109
	110	/*
	111	* io scheduler sysfs switching
	112	*/
	113	extern ssize_t elv_iosched_show(request_queue_t , char );
	114	extern ssize_t elv_iosched_store(request_queue_t , const char , size_t);
	115
	116	extern int elevator_init(request_queue_t , char );
	117	extern void elevator_exit(elevator_t *);
	118	extern int elv_rq_merge_ok(struct request , struct bio );
	119	extern int elv_try_merge(struct request , struct bio );
	120	extern int elv_try_last_merge(request_queue_t , struct bio );
	121
	122	/*
	123	* Return values from elevator merger
	124	*/
	125	#define ELEVATOR_NO_MERGE 0
	126	#define ELEVATOR_FRONT_MERGE 1
	127	#define ELEVATOR_BACK_MERGE 2
	128
	129	/*
	130	* Insertion selection
	131	*/
	132	#define ELEVATOR_INSERT_FRONT 1
	133	#define ELEVATOR_INSERT_BACK 2
	134	#define ELEVATOR_INSERT_SORT 3
	135
	136	/*
	137	* return values from elevator_may_queue_fn
	138	*/
	139	enum {
	140	ELV_MQUEUE_MAY,
	141	ELV_MQUEUE_NO,
	142	ELV_MQUEUE_MUST,
	143	};
	144
	145	#endif