Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_ELEVATOR_H |
3 | #define _LINUX_ELEVATOR_H | |
4 | ||
4a893e83 | 5 | #include <linux/percpu.h> |
242d98f0 | 6 | #include <linux/hashtable.h> |
4a893e83 | 7 | |
9361401e DH |
8 | #ifdef CONFIG_BLOCK |
9 | ||
7e5a8794 | 10 | struct io_cq; |
d50235b7 | 11 | struct elevator_type; |
d332ce09 OS |
12 | #ifdef CONFIG_BLK_DEBUG_FS |
13 | struct blk_mq_debugfs_attr; | |
14 | #endif | |
7e5a8794 | 15 | |
34fe7c05 CH |
16 | /* |
17 | * Return values from elevator merger | |
18 | */ | |
19 | enum elv_merge { | |
20 | ELEVATOR_NO_MERGE = 0, | |
21 | ELEVATOR_FRONT_MERGE = 1, | |
22 | ELEVATOR_BACK_MERGE = 2, | |
1e739730 | 23 | ELEVATOR_DISCARD_MERGE = 3, |
34fe7c05 CH |
24 | }; |
25 | ||
bd166ef1 JA |
26 | struct blk_mq_alloc_data; |
27 | struct blk_mq_hw_ctx; | |
28 | ||
29 | struct elevator_mq_ops { | |
30 | int (*init_sched)(struct request_queue *, struct elevator_type *); | |
31 | void (*exit_sched)(struct elevator_queue *); | |
ee056f98 OS |
32 | int (*init_hctx)(struct blk_mq_hw_ctx *, unsigned int); |
33 | void (*exit_hctx)(struct blk_mq_hw_ctx *, unsigned int); | |
77f1e0a5 | 34 | void (*depth_updated)(struct blk_mq_hw_ctx *); |
bd166ef1 JA |
35 | |
36 | bool (*allow_merge)(struct request_queue *, struct request *, struct bio *); | |
14ccb66b | 37 | bool (*bio_merge)(struct blk_mq_hw_ctx *, struct bio *, unsigned int); |
bd166ef1 | 38 | int (*request_merge)(struct request_queue *q, struct request **, struct bio *); |
34fe7c05 | 39 | void (*request_merged)(struct request_queue *, struct request *, enum elv_merge); |
bd166ef1 | 40 | void (*requests_merged)(struct request_queue *, struct request *, struct request *); |
5bbf4e5a CH |
41 | void (*limit_depth)(unsigned int, struct blk_mq_alloc_data *); |
42 | void (*prepare_request)(struct request *, struct bio *bio); | |
7b9e9361 | 43 | void (*finish_request)(struct request *); |
bd166ef1 | 44 | void (*insert_requests)(struct blk_mq_hw_ctx *, struct list_head *, bool); |
c13660a0 | 45 | struct request *(*dispatch_request)(struct blk_mq_hw_ctx *); |
bd166ef1 | 46 | bool (*has_work)(struct blk_mq_hw_ctx *); |
ed88660a | 47 | void (*completed_request)(struct request *, u64); |
bd166ef1 JA |
48 | void (*started_request)(struct request *); |
49 | void (*requeue_request)(struct request *); | |
50 | struct request *(*former_request)(struct request_queue *, struct request *); | |
51 | struct request *(*next_request)(struct request_queue *, struct request *); | |
bd166ef1 JA |
52 | void (*init_icq)(struct io_cq *); |
53 | void (*exit_icq)(struct io_cq *); | |
54 | }; | |
55 | ||
1da177e4 LT |
56 | #define ELV_NAME_MAX (16) |
57 | ||
e572ec7e AV |
58 | struct elv_fs_entry { |
59 | struct attribute attr; | |
b374d18a JA |
60 | ssize_t (*show)(struct elevator_queue *, char *); |
61 | ssize_t (*store)(struct elevator_queue *, const char *, size_t); | |
e572ec7e AV |
62 | }; |
63 | ||
1da177e4 LT |
64 | /* |
65 | * identifies an elevator type, such as AS or deadline | |
66 | */ | |
67 | struct elevator_type | |
68 | { | |
3d3c2379 TH |
69 | /* managed by elevator core */ |
70 | struct kmem_cache *icq_cache; | |
71 | ||
72 | /* fields provided by elevator implementation */ | |
f9cd4bfe | 73 | struct elevator_mq_ops ops; |
a1ce35fa | 74 | |
f1f8cc94 TH |
75 | size_t icq_size; /* see iocontext.h */ |
76 | size_t icq_align; /* ditto */ | |
e572ec7e | 77 | struct elv_fs_entry *elevator_attrs; |
1da177e4 | 78 | char elevator_name[ELV_NAME_MAX]; |
8ac0d9a8 | 79 | const char *elevator_alias; |
1da177e4 | 80 | struct module *elevator_owner; |
d332ce09 OS |
81 | #ifdef CONFIG_BLK_DEBUG_FS |
82 | const struct blk_mq_debugfs_attr *queue_debugfs_attrs; | |
83 | const struct blk_mq_debugfs_attr *hctx_debugfs_attrs; | |
84 | #endif | |
3d3c2379 TH |
85 | |
86 | /* managed by elevator core */ | |
9bd2bbc0 | 87 | char icq_cache_name[ELV_NAME_MAX + 6]; /* elvname + "_io_cq" */ |
22f746e2 | 88 | struct list_head list; |
1da177e4 LT |
89 | }; |
90 | ||
242d98f0 SL |
91 | #define ELV_HASH_BITS 6 |
92 | ||
70b3ea05 JA |
93 | void elv_rqhash_del(struct request_queue *q, struct request *rq); |
94 | void elv_rqhash_add(struct request_queue *q, struct request *rq); | |
95 | void elv_rqhash_reposition(struct request_queue *q, struct request *rq); | |
96 | struct request *elv_rqhash_find(struct request_queue *q, sector_t offset); | |
97 | ||
1da177e4 | 98 | /* |
54069588 | 99 | * each queue has an elevator_queue associated with it |
1da177e4 LT |
100 | */ |
101 | struct elevator_queue | |
102 | { | |
22f746e2 | 103 | struct elevator_type *type; |
1da177e4 LT |
104 | void *elevator_data; |
105 | struct kobject kobj; | |
3d1ab40f | 106 | struct mutex sysfs_lock; |
430c62fb | 107 | unsigned int registered:1; |
242d98f0 | 108 | DECLARE_HASHTABLE(hash, ELV_HASH_BITS); |
1da177e4 LT |
109 | }; |
110 | ||
111 | /* | |
112 | * block elevator interface | |
113 | */ | |
34fe7c05 CH |
114 | extern enum elv_merge elv_merge(struct request_queue *, struct request **, |
115 | struct bio *); | |
165125e1 | 116 | extern void elv_merge_requests(struct request_queue *, struct request *, |
1da177e4 | 117 | struct request *); |
34fe7c05 CH |
118 | extern void elv_merged_request(struct request_queue *, struct request *, |
119 | enum elv_merge); | |
bd166ef1 | 120 | extern bool elv_attempt_insert_merge(struct request_queue *, struct request *); |
165125e1 JA |
121 | extern struct request *elv_former_request(struct request_queue *, struct request *); |
122 | extern struct request *elv_latter_request(struct request_queue *, struct request *); | |
1da177e4 LT |
123 | |
124 | /* | |
125 | * io scheduler registration | |
126 | */ | |
e567bf71 | 127 | extern int elv_register(struct elevator_type *); |
1da177e4 LT |
128 | extern void elv_unregister(struct elevator_type *); |
129 | ||
130 | /* | |
131 | * io scheduler sysfs switching | |
132 | */ | |
165125e1 JA |
133 | extern ssize_t elv_iosched_show(struct request_queue *, char *); |
134 | extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t); | |
1da177e4 | 135 | |
72ef799b | 136 | extern bool elv_bio_merge_ok(struct request *, struct bio *); |
d50235b7 JM |
137 | extern struct elevator_queue *elevator_alloc(struct request_queue *, |
138 | struct elevator_type *); | |
1da177e4 | 139 | |
2e662b65 JA |
140 | /* |
141 | * Helper functions. | |
142 | */ | |
165125e1 JA |
143 | extern struct request *elv_rb_former_request(struct request_queue *, struct request *); |
144 | extern struct request *elv_rb_latter_request(struct request_queue *, struct request *); | |
2e662b65 JA |
145 | |
146 | /* | |
147 | * rb support functions. | |
148 | */ | |
796d5116 | 149 | extern void elv_rb_add(struct rb_root *, struct request *); |
2e662b65 JA |
150 | extern void elv_rb_del(struct rb_root *, struct request *); |
151 | extern struct request *elv_rb_find(struct rb_root *, sector_t); | |
152 | ||
1da177e4 LT |
153 | /* |
154 | * Insertion selection | |
155 | */ | |
156 | #define ELEVATOR_INSERT_FRONT 1 | |
157 | #define ELEVATOR_INSERT_BACK 2 | |
158 | #define ELEVATOR_INSERT_SORT 3 | |
797e7dbb | 159 | #define ELEVATOR_INSERT_REQUEUE 4 |
ae1b1539 | 160 | #define ELEVATOR_INSERT_FLUSH 5 |
5e84ea3a | 161 | #define ELEVATOR_INSERT_SORT_MERGE 6 |
1da177e4 LT |
162 | |
163 | /* | |
164 | * return values from elevator_may_queue_fn | |
165 | */ | |
166 | enum { | |
167 | ELV_MQUEUE_MAY, | |
168 | ELV_MQUEUE_NO, | |
169 | ELV_MQUEUE_MUST, | |
170 | }; | |
171 | ||
2e46e8b2 | 172 | #define rq_end_sector(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq)) |
2e662b65 | 173 | #define rb_entry_rq(node) rb_entry((node), struct request, rb_node) |
1b47f531 | 174 | |
1fbfdfcd | 175 | #define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist) |
d9a74df5 | 176 | #define rq_fifo_clear(rq) list_del_init(&(rq)->queuelist) |
1fbfdfcd | 177 | |
9361401e | 178 | #endif /* CONFIG_BLOCK */ |
1da177e4 | 179 | #endif |