Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | #ifndef _LINUX_ELEVATOR_H |
2 | #define _LINUX_ELEVATOR_H | |
3 | ||
4a893e83 JA |
4 | #include <linux/percpu.h> |
5 | ||
9361401e DH |
6 | #ifdef CONFIG_BLOCK |
7 | ||
7e5a8794 TH |
8 | struct io_cq; |
9 | ||
165125e1 | 10 | typedef int (elevator_merge_fn) (struct request_queue *, struct request **, |
1da177e4 LT |
11 | struct bio *); |
12 | ||
165125e1 | 13 | typedef void (elevator_merge_req_fn) (struct request_queue *, struct request *, struct request *); |
1da177e4 | 14 | |
165125e1 | 15 | typedef void (elevator_merged_fn) (struct request_queue *, struct request *, int); |
1da177e4 | 16 | |
165125e1 | 17 | typedef int (elevator_allow_merge_fn) (struct request_queue *, struct request *, struct bio *); |
da775265 | 18 | |
812d4026 DS |
19 | typedef void (elevator_bio_merged_fn) (struct request_queue *, |
20 | struct request *, struct bio *); | |
21 | ||
165125e1 | 22 | typedef int (elevator_dispatch_fn) (struct request_queue *, int); |
1da177e4 | 23 | |
165125e1 | 24 | typedef void (elevator_add_req_fn) (struct request_queue *, struct request *); |
165125e1 JA |
25 | typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *); |
26 | typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *); | |
27 | typedef int (elevator_may_queue_fn) (struct request_queue *, int); | |
1da177e4 | 28 | |
9b84cacd | 29 | typedef void (elevator_init_icq_fn) (struct io_cq *); |
7e5a8794 | 30 | typedef void (elevator_exit_icq_fn) (struct io_cq *); |
852c788f TH |
31 | typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, |
32 | struct bio *, gfp_t); | |
bb37b94c | 33 | typedef void (elevator_put_req_fn) (struct request *); |
165125e1 JA |
34 | typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *); |
35 | typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *); | |
1da177e4 | 36 | |
b2fab5ac | 37 | typedef int (elevator_init_fn) (struct request_queue *); |
b374d18a | 38 | typedef void (elevator_exit_fn) (struct elevator_queue *); |
1da177e4 LT |
39 | |
40 | struct elevator_ops | |
41 | { | |
42 | elevator_merge_fn *elevator_merge_fn; | |
43 | elevator_merged_fn *elevator_merged_fn; | |
44 | elevator_merge_req_fn *elevator_merge_req_fn; | |
da775265 | 45 | elevator_allow_merge_fn *elevator_allow_merge_fn; |
812d4026 | 46 | elevator_bio_merged_fn *elevator_bio_merged_fn; |
1da177e4 | 47 | |
8922e16c | 48 | elevator_dispatch_fn *elevator_dispatch_fn; |
1da177e4 | 49 | elevator_add_req_fn *elevator_add_req_fn; |
8922e16c | 50 | elevator_activate_req_fn *elevator_activate_req_fn; |
1da177e4 LT |
51 | elevator_deactivate_req_fn *elevator_deactivate_req_fn; |
52 | ||
1da177e4 LT |
53 | elevator_completed_req_fn *elevator_completed_req_fn; |
54 | ||
55 | elevator_request_list_fn *elevator_former_req_fn; | |
56 | elevator_request_list_fn *elevator_latter_req_fn; | |
57 | ||
f1f8cc94 TH |
58 | elevator_init_icq_fn *elevator_init_icq_fn; /* see iocontext.h */ |
59 | elevator_exit_icq_fn *elevator_exit_icq_fn; /* ditto */ | |
7e5a8794 | 60 | |
1da177e4 LT |
61 | elevator_set_req_fn *elevator_set_req_fn; |
62 | elevator_put_req_fn *elevator_put_req_fn; | |
63 | ||
64 | elevator_may_queue_fn *elevator_may_queue_fn; | |
65 | ||
66 | elevator_init_fn *elevator_init_fn; | |
67 | elevator_exit_fn *elevator_exit_fn; | |
68 | }; | |
69 | ||
70 | #define ELV_NAME_MAX (16) | |
71 | ||
e572ec7e AV |
72 | struct elv_fs_entry { |
73 | struct attribute attr; | |
b374d18a JA |
74 | ssize_t (*show)(struct elevator_queue *, char *); |
75 | ssize_t (*store)(struct elevator_queue *, const char *, size_t); | |
e572ec7e AV |
76 | }; |
77 | ||
1da177e4 LT |
78 | /* |
79 | * identifies an elevator type, such as AS or deadline | |
80 | */ | |
81 | struct elevator_type | |
82 | { | |
3d3c2379 TH |
83 | /* managed by elevator core */ |
84 | struct kmem_cache *icq_cache; | |
85 | ||
86 | /* fields provided by elevator implementation */ | |
1da177e4 | 87 | struct elevator_ops ops; |
f1f8cc94 TH |
88 | size_t icq_size; /* see iocontext.h */ |
89 | size_t icq_align; /* ditto */ | |
e572ec7e | 90 | struct elv_fs_entry *elevator_attrs; |
1da177e4 LT |
91 | char elevator_name[ELV_NAME_MAX]; |
92 | struct module *elevator_owner; | |
3d3c2379 TH |
93 | |
94 | /* managed by elevator core */ | |
95 | char icq_cache_name[ELV_NAME_MAX + 5]; /* elvname + "_io_cq" */ | |
22f746e2 | 96 | struct list_head list; |
1da177e4 LT |
97 | }; |
98 | ||
99 | /* | |
54069588 | 100 | * each queue has an elevator_queue associated with it |
1da177e4 LT |
101 | */ |
102 | struct elevator_queue | |
103 | { | |
22f746e2 | 104 | struct elevator_type *type; |
1da177e4 LT |
105 | void *elevator_data; |
106 | struct kobject kobj; | |
3d1ab40f | 107 | struct mutex sysfs_lock; |
9817064b | 108 | struct hlist_head *hash; |
430c62fb | 109 | unsigned int registered:1; |
1da177e4 LT |
110 | }; |
111 | ||
112 | /* | |
113 | * block elevator interface | |
114 | */ | |
165125e1 JA |
115 | extern void elv_dispatch_sort(struct request_queue *, struct request *); |
116 | extern void elv_dispatch_add_tail(struct request_queue *, struct request *); | |
7eaceacc JA |
117 | extern void elv_add_request(struct request_queue *, struct request *, int); |
118 | extern void __elv_add_request(struct request_queue *, struct request *, int); | |
165125e1 JA |
119 | extern int elv_merge(struct request_queue *, struct request **, struct bio *); |
120 | extern void elv_merge_requests(struct request_queue *, struct request *, | |
1da177e4 | 121 | struct request *); |
165125e1 | 122 | extern void elv_merged_request(struct request_queue *, struct request *, int); |
812d4026 DS |
123 | extern void elv_bio_merged(struct request_queue *q, struct request *, |
124 | struct bio *); | |
165125e1 | 125 | extern void elv_requeue_request(struct request_queue *, struct request *); |
165125e1 JA |
126 | extern struct request *elv_former_request(struct request_queue *, struct request *); |
127 | extern struct request *elv_latter_request(struct request_queue *, struct request *); | |
128 | extern int elv_register_queue(struct request_queue *q); | |
129 | extern void elv_unregister_queue(struct request_queue *q); | |
130 | extern int elv_may_queue(struct request_queue *, int); | |
11914a53 | 131 | extern void elv_abort_queue(struct request_queue *); |
165125e1 | 132 | extern void elv_completed_request(struct request_queue *, struct request *); |
852c788f TH |
133 | extern int elv_set_request(struct request_queue *q, struct request *rq, |
134 | struct bio *bio, gfp_t gfp_mask); | |
165125e1 | 135 | extern void elv_put_request(struct request_queue *, struct request *); |
26308eab | 136 | extern void elv_drain_elevator(struct request_queue *); |
1da177e4 LT |
137 | |
138 | /* | |
139 | * io scheduler registration | |
140 | */ | |
3d3c2379 | 141 | extern int elv_register(struct elevator_type *); |
1da177e4 LT |
142 | extern void elv_unregister(struct elevator_type *); |
143 | ||
144 | /* | |
145 | * io scheduler sysfs switching | |
146 | */ | |
165125e1 JA |
147 | extern ssize_t elv_iosched_show(struct request_queue *, char *); |
148 | extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t); | |
1da177e4 | 149 | |
165125e1 | 150 | extern int elevator_init(struct request_queue *, char *); |
b374d18a | 151 | extern void elevator_exit(struct elevator_queue *); |
5dd531a0 | 152 | extern int elevator_change(struct request_queue *, const char *); |
050c8ea8 | 153 | extern bool elv_rq_merge_ok(struct request *, struct bio *); |
1da177e4 | 154 | |
2e662b65 JA |
155 | /* |
156 | * Helper functions. | |
157 | */ | |
165125e1 JA |
158 | extern struct request *elv_rb_former_request(struct request_queue *, struct request *); |
159 | extern struct request *elv_rb_latter_request(struct request_queue *, struct request *); | |
2e662b65 JA |
160 | |
161 | /* | |
162 | * rb support functions. | |
163 | */ | |
796d5116 | 164 | extern void elv_rb_add(struct rb_root *, struct request *); |
2e662b65 JA |
165 | extern void elv_rb_del(struct rb_root *, struct request *); |
166 | extern struct request *elv_rb_find(struct rb_root *, sector_t); | |
167 | ||
1da177e4 LT |
168 | /* |
169 | * Return values from elevator merger | |
170 | */ | |
171 | #define ELEVATOR_NO_MERGE 0 | |
172 | #define ELEVATOR_FRONT_MERGE 1 | |
173 | #define ELEVATOR_BACK_MERGE 2 | |
174 | ||
175 | /* | |
176 | * Insertion selection | |
177 | */ | |
178 | #define ELEVATOR_INSERT_FRONT 1 | |
179 | #define ELEVATOR_INSERT_BACK 2 | |
180 | #define ELEVATOR_INSERT_SORT 3 | |
797e7dbb | 181 | #define ELEVATOR_INSERT_REQUEUE 4 |
ae1b1539 | 182 | #define ELEVATOR_INSERT_FLUSH 5 |
5e84ea3a | 183 | #define ELEVATOR_INSERT_SORT_MERGE 6 |
1da177e4 LT |
184 | |
185 | /* | |
186 | * return values from elevator_may_queue_fn | |
187 | */ | |
188 | enum { | |
189 | ELV_MQUEUE_MAY, | |
190 | ELV_MQUEUE_NO, | |
191 | ELV_MQUEUE_MUST, | |
192 | }; | |
193 | ||
2e46e8b2 | 194 | #define rq_end_sector(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq)) |
2e662b65 | 195 | #define rb_entry_rq(node) rb_entry((node), struct request, rb_node) |
1b47f531 | 196 | |
1fbfdfcd | 197 | /* |
c7c22e4d | 198 | * Hack to reuse the csd.list list_head as the fifo time holder while |
1fbfdfcd JA |
199 | * the request is in the io scheduler. Saves an unsigned long in rq. |
200 | */ | |
c7c22e4d JA |
201 | #define rq_fifo_time(rq) ((unsigned long) (rq)->csd.list.next) |
202 | #define rq_set_fifo_time(rq,exp) ((rq)->csd.list.next = (void *) (exp)) | |
1fbfdfcd JA |
203 | #define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist) |
204 | #define rq_fifo_clear(rq) do { \ | |
205 | list_del_init(&(rq)->queuelist); \ | |
c7c22e4d | 206 | INIT_LIST_HEAD(&(rq)->csd.list); \ |
1fbfdfcd JA |
207 | } while (0) |
208 | ||
9361401e | 209 | #endif /* CONFIG_BLOCK */ |
1da177e4 | 210 | #endif |