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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 | ||
8922e16c | 11 | typedef int (elevator_dispatch_fn) (request_queue_t *, int); |
1da177e4 | 12 | |
8922e16c | 13 | typedef void (elevator_add_req_fn) (request_queue_t *, struct request *); |
1da177e4 | 14 | typedef int (elevator_queue_empty_fn) (request_queue_t *); |
1da177e4 LT |
15 | typedef struct request *(elevator_request_list_fn) (request_queue_t *, struct request *); |
16 | typedef void (elevator_completed_req_fn) (request_queue_t *, struct request *); | |
22e2c507 | 17 | typedef int (elevator_may_queue_fn) (request_queue_t *, int, struct bio *); |
1da177e4 | 18 | |
22e2c507 | 19 | typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, struct bio *, int); |
1da177e4 | 20 | typedef void (elevator_put_req_fn) (request_queue_t *, struct request *); |
8922e16c | 21 | typedef void (elevator_activate_req_fn) (request_queue_t *, struct request *); |
1da177e4 LT |
22 | typedef void (elevator_deactivate_req_fn) (request_queue_t *, struct request *); |
23 | ||
24 | typedef int (elevator_init_fn) (request_queue_t *, elevator_t *); | |
25 | typedef void (elevator_exit_fn) (elevator_t *); | |
26 | ||
27 | struct elevator_ops | |
28 | { | |
29 | elevator_merge_fn *elevator_merge_fn; | |
30 | elevator_merged_fn *elevator_merged_fn; | |
31 | elevator_merge_req_fn *elevator_merge_req_fn; | |
32 | ||
8922e16c | 33 | elevator_dispatch_fn *elevator_dispatch_fn; |
1da177e4 | 34 | elevator_add_req_fn *elevator_add_req_fn; |
8922e16c | 35 | elevator_activate_req_fn *elevator_activate_req_fn; |
1da177e4 LT |
36 | elevator_deactivate_req_fn *elevator_deactivate_req_fn; |
37 | ||
38 | elevator_queue_empty_fn *elevator_queue_empty_fn; | |
39 | elevator_completed_req_fn *elevator_completed_req_fn; | |
40 | ||
41 | elevator_request_list_fn *elevator_former_req_fn; | |
42 | elevator_request_list_fn *elevator_latter_req_fn; | |
43 | ||
44 | elevator_set_req_fn *elevator_set_req_fn; | |
45 | elevator_put_req_fn *elevator_put_req_fn; | |
46 | ||
47 | elevator_may_queue_fn *elevator_may_queue_fn; | |
48 | ||
49 | elevator_init_fn *elevator_init_fn; | |
50 | elevator_exit_fn *elevator_exit_fn; | |
51 | }; | |
52 | ||
53 | #define ELV_NAME_MAX (16) | |
54 | ||
55 | /* | |
56 | * identifies an elevator type, such as AS or deadline | |
57 | */ | |
58 | struct elevator_type | |
59 | { | |
60 | struct list_head list; | |
61 | struct elevator_ops ops; | |
62 | struct elevator_type *elevator_type; | |
63 | struct kobj_type *elevator_ktype; | |
64 | char elevator_name[ELV_NAME_MAX]; | |
65 | struct module *elevator_owner; | |
66 | }; | |
67 | ||
68 | /* | |
69 | * each queue has an elevator_queue assoicated with it | |
70 | */ | |
71 | struct elevator_queue | |
72 | { | |
73 | struct elevator_ops *ops; | |
74 | void *elevator_data; | |
75 | struct kobject kobj; | |
76 | struct elevator_type *elevator_type; | |
77 | }; | |
78 | ||
79 | /* | |
80 | * block elevator interface | |
81 | */ | |
8922e16c | 82 | extern void elv_dispatch_insert(request_queue_t *, struct request *, int); |
1da177e4 LT |
83 | extern void elv_add_request(request_queue_t *, struct request *, int, int); |
84 | extern void __elv_add_request(request_queue_t *, struct request *, int, int); | |
85 | extern int elv_merge(request_queue_t *, struct request **, struct bio *); | |
86 | extern void elv_merge_requests(request_queue_t *, struct request *, | |
87 | struct request *); | |
88 | extern void elv_merged_request(request_queue_t *, struct request *); | |
8922e16c | 89 | extern void elv_dequeue_request(request_queue_t *, struct request *); |
1da177e4 | 90 | extern void elv_requeue_request(request_queue_t *, struct request *); |
1da177e4 LT |
91 | extern int elv_queue_empty(request_queue_t *); |
92 | extern struct request *elv_next_request(struct request_queue *q); | |
93 | extern struct request *elv_former_request(request_queue_t *, struct request *); | |
94 | extern struct request *elv_latter_request(request_queue_t *, struct request *); | |
95 | extern int elv_register_queue(request_queue_t *q); | |
96 | extern void elv_unregister_queue(request_queue_t *q); | |
22e2c507 | 97 | extern int elv_may_queue(request_queue_t *, int, struct bio *); |
1da177e4 | 98 | extern void elv_completed_request(request_queue_t *, struct request *); |
22e2c507 | 99 | extern int elv_set_request(request_queue_t *, struct request *, struct bio *, int); |
1da177e4 LT |
100 | extern void elv_put_request(request_queue_t *, struct request *); |
101 | ||
102 | /* | |
103 | * io scheduler registration | |
104 | */ | |
105 | extern int elv_register(struct elevator_type *); | |
106 | extern void elv_unregister(struct elevator_type *); | |
107 | ||
108 | /* | |
109 | * io scheduler sysfs switching | |
110 | */ | |
111 | extern ssize_t elv_iosched_show(request_queue_t *, char *); | |
112 | extern ssize_t elv_iosched_store(request_queue_t *, const char *, size_t); | |
113 | ||
114 | extern int elevator_init(request_queue_t *, char *); | |
115 | extern void elevator_exit(elevator_t *); | |
116 | extern int elv_rq_merge_ok(struct request *, struct bio *); | |
117 | extern int elv_try_merge(struct request *, struct bio *); | |
118 | extern int elv_try_last_merge(request_queue_t *, struct bio *); | |
119 | ||
120 | /* | |
121 | * Return values from elevator merger | |
122 | */ | |
123 | #define ELEVATOR_NO_MERGE 0 | |
124 | #define ELEVATOR_FRONT_MERGE 1 | |
125 | #define ELEVATOR_BACK_MERGE 2 | |
126 | ||
127 | /* | |
128 | * Insertion selection | |
129 | */ | |
130 | #define ELEVATOR_INSERT_FRONT 1 | |
131 | #define ELEVATOR_INSERT_BACK 2 | |
132 | #define ELEVATOR_INSERT_SORT 3 | |
133 | ||
134 | /* | |
135 | * return values from elevator_may_queue_fn | |
136 | */ | |
137 | enum { | |
138 | ELV_MQUEUE_MAY, | |
139 | ELV_MQUEUE_NO, | |
140 | ELV_MQUEUE_MUST, | |
141 | }; | |
142 | ||
143 | #endif |