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1da177e4 LT |
1 | #ifndef _LINUX_ELEVATOR_H |
2 | #define _LINUX_ELEVATOR_H | |
3 | ||
4a893e83 | 4 | #include <linux/percpu.h> |
242d98f0 | 5 | #include <linux/hashtable.h> |
4a893e83 | 6 | |
9361401e DH |
7 | #ifdef CONFIG_BLOCK |
8 | ||
7e5a8794 | 9 | struct io_cq; |
d50235b7 | 10 | struct elevator_type; |
d332ce09 OS |
11 | #ifdef CONFIG_BLK_DEBUG_FS |
12 | struct blk_mq_debugfs_attr; | |
13 | #endif | |
7e5a8794 | 14 | |
34fe7c05 CH |
15 | /* |
16 | * Return values from elevator merger | |
17 | */ | |
18 | enum elv_merge { | |
19 | ELEVATOR_NO_MERGE = 0, | |
20 | ELEVATOR_FRONT_MERGE = 1, | |
21 | ELEVATOR_BACK_MERGE = 2, | |
1e739730 | 22 | ELEVATOR_DISCARD_MERGE = 3, |
34fe7c05 CH |
23 | }; |
24 | ||
25 | typedef enum elv_merge (elevator_merge_fn) (struct request_queue *, struct request **, | |
1da177e4 LT |
26 | struct bio *); |
27 | ||
165125e1 | 28 | typedef void (elevator_merge_req_fn) (struct request_queue *, struct request *, struct request *); |
1da177e4 | 29 | |
34fe7c05 | 30 | typedef void (elevator_merged_fn) (struct request_queue *, struct request *, enum elv_merge); |
1da177e4 | 31 | |
72ef799b TE |
32 | typedef int (elevator_allow_bio_merge_fn) (struct request_queue *, |
33 | struct request *, struct bio *); | |
34 | ||
35 | typedef int (elevator_allow_rq_merge_fn) (struct request_queue *, | |
36 | struct request *, struct request *); | |
da775265 | 37 | |
812d4026 DS |
38 | typedef void (elevator_bio_merged_fn) (struct request_queue *, |
39 | struct request *, struct bio *); | |
40 | ||
165125e1 | 41 | typedef int (elevator_dispatch_fn) (struct request_queue *, int); |
1da177e4 | 42 | |
165125e1 | 43 | typedef void (elevator_add_req_fn) (struct request_queue *, struct request *); |
165125e1 JA |
44 | typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *); |
45 | typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *); | |
ef295ecf | 46 | typedef int (elevator_may_queue_fn) (struct request_queue *, unsigned int); |
1da177e4 | 47 | |
9b84cacd | 48 | typedef void (elevator_init_icq_fn) (struct io_cq *); |
7e5a8794 | 49 | typedef void (elevator_exit_icq_fn) (struct io_cq *); |
852c788f TH |
50 | typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, |
51 | struct bio *, gfp_t); | |
bb37b94c | 52 | typedef void (elevator_put_req_fn) (struct request *); |
165125e1 JA |
53 | typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *); |
54 | typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *); | |
1da177e4 | 55 | |
d50235b7 JM |
56 | typedef int (elevator_init_fn) (struct request_queue *, |
57 | struct elevator_type *e); | |
b374d18a | 58 | typedef void (elevator_exit_fn) (struct elevator_queue *); |
0bb97947 | 59 | typedef void (elevator_registered_fn) (struct request_queue *); |
1da177e4 LT |
60 | |
61 | struct elevator_ops | |
62 | { | |
63 | elevator_merge_fn *elevator_merge_fn; | |
64 | elevator_merged_fn *elevator_merged_fn; | |
65 | elevator_merge_req_fn *elevator_merge_req_fn; | |
72ef799b TE |
66 | elevator_allow_bio_merge_fn *elevator_allow_bio_merge_fn; |
67 | elevator_allow_rq_merge_fn *elevator_allow_rq_merge_fn; | |
812d4026 | 68 | elevator_bio_merged_fn *elevator_bio_merged_fn; |
1da177e4 | 69 | |
8922e16c | 70 | elevator_dispatch_fn *elevator_dispatch_fn; |
1da177e4 | 71 | elevator_add_req_fn *elevator_add_req_fn; |
8922e16c | 72 | elevator_activate_req_fn *elevator_activate_req_fn; |
1da177e4 LT |
73 | elevator_deactivate_req_fn *elevator_deactivate_req_fn; |
74 | ||
1da177e4 LT |
75 | elevator_completed_req_fn *elevator_completed_req_fn; |
76 | ||
77 | elevator_request_list_fn *elevator_former_req_fn; | |
78 | elevator_request_list_fn *elevator_latter_req_fn; | |
79 | ||
f1f8cc94 TH |
80 | elevator_init_icq_fn *elevator_init_icq_fn; /* see iocontext.h */ |
81 | elevator_exit_icq_fn *elevator_exit_icq_fn; /* ditto */ | |
7e5a8794 | 82 | |
1da177e4 LT |
83 | elevator_set_req_fn *elevator_set_req_fn; |
84 | elevator_put_req_fn *elevator_put_req_fn; | |
85 | ||
86 | elevator_may_queue_fn *elevator_may_queue_fn; | |
87 | ||
88 | elevator_init_fn *elevator_init_fn; | |
89 | elevator_exit_fn *elevator_exit_fn; | |
0bb97947 | 90 | elevator_registered_fn *elevator_registered_fn; |
1da177e4 LT |
91 | }; |
92 | ||
bd166ef1 JA |
93 | struct blk_mq_alloc_data; |
94 | struct blk_mq_hw_ctx; | |
95 | ||
96 | struct elevator_mq_ops { | |
97 | int (*init_sched)(struct request_queue *, struct elevator_type *); | |
98 | void (*exit_sched)(struct elevator_queue *); | |
ee056f98 OS |
99 | int (*init_hctx)(struct blk_mq_hw_ctx *, unsigned int); |
100 | void (*exit_hctx)(struct blk_mq_hw_ctx *, unsigned int); | |
bd166ef1 JA |
101 | |
102 | bool (*allow_merge)(struct request_queue *, struct request *, struct bio *); | |
103 | bool (*bio_merge)(struct blk_mq_hw_ctx *, struct bio *); | |
104 | int (*request_merge)(struct request_queue *q, struct request **, struct bio *); | |
34fe7c05 | 105 | void (*request_merged)(struct request_queue *, struct request *, enum elv_merge); |
bd166ef1 JA |
106 | void (*requests_merged)(struct request_queue *, struct request *, struct request *); |
107 | struct request *(*get_request)(struct request_queue *, unsigned int, struct blk_mq_alloc_data *); | |
7b9e9361 | 108 | void (*finish_request)(struct request *); |
bd166ef1 | 109 | void (*insert_requests)(struct blk_mq_hw_ctx *, struct list_head *, bool); |
c13660a0 | 110 | struct request *(*dispatch_request)(struct blk_mq_hw_ctx *); |
bd166ef1 | 111 | bool (*has_work)(struct blk_mq_hw_ctx *); |
c05f8525 | 112 | void (*completed_request)(struct request *); |
bd166ef1 JA |
113 | void (*started_request)(struct request *); |
114 | void (*requeue_request)(struct request *); | |
115 | struct request *(*former_request)(struct request_queue *, struct request *); | |
116 | struct request *(*next_request)(struct request_queue *, struct request *); | |
f1ba8261 | 117 | int (*get_rq_priv)(struct request_queue *, struct request *, struct bio *); |
bd166ef1 JA |
118 | void (*init_icq)(struct io_cq *); |
119 | void (*exit_icq)(struct io_cq *); | |
120 | }; | |
121 | ||
1da177e4 LT |
122 | #define ELV_NAME_MAX (16) |
123 | ||
e572ec7e AV |
124 | struct elv_fs_entry { |
125 | struct attribute attr; | |
b374d18a JA |
126 | ssize_t (*show)(struct elevator_queue *, char *); |
127 | ssize_t (*store)(struct elevator_queue *, const char *, size_t); | |
e572ec7e AV |
128 | }; |
129 | ||
1da177e4 LT |
130 | /* |
131 | * identifies an elevator type, such as AS or deadline | |
132 | */ | |
133 | struct elevator_type | |
134 | { | |
3d3c2379 TH |
135 | /* managed by elevator core */ |
136 | struct kmem_cache *icq_cache; | |
137 | ||
138 | /* fields provided by elevator implementation */ | |
c51ca6cf JA |
139 | union { |
140 | struct elevator_ops sq; | |
bd166ef1 | 141 | struct elevator_mq_ops mq; |
c51ca6cf | 142 | } ops; |
f1f8cc94 TH |
143 | size_t icq_size; /* see iocontext.h */ |
144 | size_t icq_align; /* ditto */ | |
e572ec7e | 145 | struct elv_fs_entry *elevator_attrs; |
1da177e4 LT |
146 | char elevator_name[ELV_NAME_MAX]; |
147 | struct module *elevator_owner; | |
bd166ef1 | 148 | bool uses_mq; |
d332ce09 OS |
149 | #ifdef CONFIG_BLK_DEBUG_FS |
150 | const struct blk_mq_debugfs_attr *queue_debugfs_attrs; | |
151 | const struct blk_mq_debugfs_attr *hctx_debugfs_attrs; | |
152 | #endif | |
3d3c2379 TH |
153 | |
154 | /* managed by elevator core */ | |
9bd2bbc0 | 155 | char icq_cache_name[ELV_NAME_MAX + 6]; /* elvname + "_io_cq" */ |
22f746e2 | 156 | struct list_head list; |
1da177e4 LT |
157 | }; |
158 | ||
242d98f0 SL |
159 | #define ELV_HASH_BITS 6 |
160 | ||
70b3ea05 JA |
161 | void elv_rqhash_del(struct request_queue *q, struct request *rq); |
162 | void elv_rqhash_add(struct request_queue *q, struct request *rq); | |
163 | void elv_rqhash_reposition(struct request_queue *q, struct request *rq); | |
164 | struct request *elv_rqhash_find(struct request_queue *q, sector_t offset); | |
165 | ||
1da177e4 | 166 | /* |
54069588 | 167 | * each queue has an elevator_queue associated with it |
1da177e4 LT |
168 | */ |
169 | struct elevator_queue | |
170 | { | |
22f746e2 | 171 | struct elevator_type *type; |
1da177e4 LT |
172 | void *elevator_data; |
173 | struct kobject kobj; | |
3d1ab40f | 174 | struct mutex sysfs_lock; |
430c62fb | 175 | unsigned int registered:1; |
bd166ef1 | 176 | unsigned int uses_mq:1; |
242d98f0 | 177 | DECLARE_HASHTABLE(hash, ELV_HASH_BITS); |
1da177e4 LT |
178 | }; |
179 | ||
180 | /* | |
181 | * block elevator interface | |
182 | */ | |
165125e1 JA |
183 | extern void elv_dispatch_sort(struct request_queue *, struct request *); |
184 | extern void elv_dispatch_add_tail(struct request_queue *, struct request *); | |
7eaceacc JA |
185 | extern void elv_add_request(struct request_queue *, struct request *, int); |
186 | extern void __elv_add_request(struct request_queue *, struct request *, int); | |
34fe7c05 CH |
187 | extern enum elv_merge elv_merge(struct request_queue *, struct request **, |
188 | struct bio *); | |
165125e1 | 189 | extern void elv_merge_requests(struct request_queue *, struct request *, |
1da177e4 | 190 | struct request *); |
34fe7c05 CH |
191 | extern void elv_merged_request(struct request_queue *, struct request *, |
192 | enum elv_merge); | |
812d4026 DS |
193 | extern void elv_bio_merged(struct request_queue *q, struct request *, |
194 | struct bio *); | |
bd166ef1 | 195 | extern bool elv_attempt_insert_merge(struct request_queue *, struct request *); |
165125e1 | 196 | extern void elv_requeue_request(struct request_queue *, struct request *); |
165125e1 JA |
197 | extern struct request *elv_former_request(struct request_queue *, struct request *); |
198 | extern struct request *elv_latter_request(struct request_queue *, struct request *); | |
199 | extern int elv_register_queue(struct request_queue *q); | |
200 | extern void elv_unregister_queue(struct request_queue *q); | |
ef295ecf | 201 | extern int elv_may_queue(struct request_queue *, unsigned int); |
165125e1 | 202 | extern void elv_completed_request(struct request_queue *, struct request *); |
852c788f TH |
203 | extern int elv_set_request(struct request_queue *q, struct request *rq, |
204 | struct bio *bio, gfp_t gfp_mask); | |
165125e1 | 205 | extern void elv_put_request(struct request_queue *, struct request *); |
26308eab | 206 | extern void elv_drain_elevator(struct request_queue *); |
1da177e4 LT |
207 | |
208 | /* | |
209 | * io scheduler registration | |
210 | */ | |
bb813f4c | 211 | extern void __init load_default_elevator_module(void); |
e567bf71 | 212 | extern int elv_register(struct elevator_type *); |
1da177e4 LT |
213 | extern void elv_unregister(struct elevator_type *); |
214 | ||
215 | /* | |
216 | * io scheduler sysfs switching | |
217 | */ | |
165125e1 JA |
218 | extern ssize_t elv_iosched_show(struct request_queue *, char *); |
219 | extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t); | |
1da177e4 | 220 | |
165125e1 | 221 | extern int elevator_init(struct request_queue *, char *); |
54d5329d | 222 | extern void elevator_exit(struct request_queue *, struct elevator_queue *); |
72ef799b | 223 | extern bool elv_bio_merge_ok(struct request *, struct bio *); |
d50235b7 JM |
224 | extern struct elevator_queue *elevator_alloc(struct request_queue *, |
225 | struct elevator_type *); | |
1da177e4 | 226 | |
2e662b65 JA |
227 | /* |
228 | * Helper functions. | |
229 | */ | |
165125e1 JA |
230 | extern struct request *elv_rb_former_request(struct request_queue *, struct request *); |
231 | extern struct request *elv_rb_latter_request(struct request_queue *, struct request *); | |
2e662b65 JA |
232 | |
233 | /* | |
234 | * rb support functions. | |
235 | */ | |
796d5116 | 236 | extern void elv_rb_add(struct rb_root *, struct request *); |
2e662b65 JA |
237 | extern void elv_rb_del(struct rb_root *, struct request *); |
238 | extern struct request *elv_rb_find(struct rb_root *, sector_t); | |
239 | ||
1da177e4 LT |
240 | /* |
241 | * Insertion selection | |
242 | */ | |
243 | #define ELEVATOR_INSERT_FRONT 1 | |
244 | #define ELEVATOR_INSERT_BACK 2 | |
245 | #define ELEVATOR_INSERT_SORT 3 | |
797e7dbb | 246 | #define ELEVATOR_INSERT_REQUEUE 4 |
ae1b1539 | 247 | #define ELEVATOR_INSERT_FLUSH 5 |
5e84ea3a | 248 | #define ELEVATOR_INSERT_SORT_MERGE 6 |
1da177e4 LT |
249 | |
250 | /* | |
251 | * return values from elevator_may_queue_fn | |
252 | */ | |
253 | enum { | |
254 | ELV_MQUEUE_MAY, | |
255 | ELV_MQUEUE_NO, | |
256 | ELV_MQUEUE_MUST, | |
257 | }; | |
258 | ||
2e46e8b2 | 259 | #define rq_end_sector(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq)) |
2e662b65 | 260 | #define rb_entry_rq(node) rb_entry((node), struct request, rb_node) |
1b47f531 | 261 | |
1fbfdfcd | 262 | #define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist) |
d9a74df5 | 263 | #define rq_fifo_clear(rq) list_del_init(&(rq)->queuelist) |
1fbfdfcd | 264 | |
bb813f4c TH |
265 | #else /* CONFIG_BLOCK */ |
266 | ||
267 | static inline void load_default_elevator_module(void) { } | |
268 | ||
9361401e | 269 | #endif /* CONFIG_BLOCK */ |
1da177e4 | 270 | #endif |