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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2e9bc346 CH |
2 | #ifndef _ELEVATOR_H |
3 | #define _ELEVATOR_H | |
1da177e4 | 4 | |
4a893e83 | 5 | #include <linux/percpu.h> |
242d98f0 | 6 | #include <linux/hashtable.h> |
4a893e83 | 7 | |
7e5a8794 | 8 | struct io_cq; |
d50235b7 | 9 | struct elevator_type; |
d332ce09 | 10 | struct blk_mq_debugfs_attr; |
7e5a8794 | 11 | |
34fe7c05 CH |
12 | /* |
13 | * Return values from elevator merger | |
14 | */ | |
15 | enum elv_merge { | |
16 | ELEVATOR_NO_MERGE = 0, | |
17 | ELEVATOR_FRONT_MERGE = 1, | |
18 | ELEVATOR_BACK_MERGE = 2, | |
1e739730 | 19 | ELEVATOR_DISCARD_MERGE = 3, |
34fe7c05 CH |
20 | }; |
21 | ||
bd166ef1 JA |
22 | struct blk_mq_alloc_data; |
23 | struct blk_mq_hw_ctx; | |
24 | ||
25 | struct elevator_mq_ops { | |
26 | int (*init_sched)(struct request_queue *, struct elevator_type *); | |
27 | void (*exit_sched)(struct elevator_queue *); | |
ee056f98 OS |
28 | int (*init_hctx)(struct blk_mq_hw_ctx *, unsigned int); |
29 | void (*exit_hctx)(struct blk_mq_hw_ctx *, unsigned int); | |
77f1e0a5 | 30 | void (*depth_updated)(struct blk_mq_hw_ctx *); |
bd166ef1 JA |
31 | |
32 | bool (*allow_merge)(struct request_queue *, struct request *, struct bio *); | |
efed9a33 | 33 | bool (*bio_merge)(struct request_queue *, struct bio *, unsigned int); |
bd166ef1 | 34 | int (*request_merge)(struct request_queue *q, struct request **, struct bio *); |
34fe7c05 | 35 | void (*request_merged)(struct request_queue *, struct request *, enum elv_merge); |
bd166ef1 | 36 | void (*requests_merged)(struct request_queue *, struct request *, struct request *); |
16458cf3 | 37 | void (*limit_depth)(blk_opf_t, struct blk_mq_alloc_data *); |
5d9c305b | 38 | void (*prepare_request)(struct request *); |
7b9e9361 | 39 | void (*finish_request)(struct request *); |
bd166ef1 | 40 | void (*insert_requests)(struct blk_mq_hw_ctx *, struct list_head *, bool); |
c13660a0 | 41 | struct request *(*dispatch_request)(struct blk_mq_hw_ctx *); |
bd166ef1 | 42 | bool (*has_work)(struct blk_mq_hw_ctx *); |
ed88660a | 43 | void (*completed_request)(struct request *, u64); |
bd166ef1 JA |
44 | void (*requeue_request)(struct request *); |
45 | struct request *(*former_request)(struct request_queue *, struct request *); | |
46 | struct request *(*next_request)(struct request_queue *, struct request *); | |
bd166ef1 JA |
47 | void (*init_icq)(struct io_cq *); |
48 | void (*exit_icq)(struct io_cq *); | |
49 | }; | |
50 | ||
1da177e4 LT |
51 | #define ELV_NAME_MAX (16) |
52 | ||
e572ec7e AV |
53 | struct elv_fs_entry { |
54 | struct attribute attr; | |
b374d18a JA |
55 | ssize_t (*show)(struct elevator_queue *, char *); |
56 | ssize_t (*store)(struct elevator_queue *, const char *, size_t); | |
e572ec7e AV |
57 | }; |
58 | ||
1da177e4 LT |
59 | /* |
60 | * identifies an elevator type, such as AS or deadline | |
61 | */ | |
62 | struct elevator_type | |
63 | { | |
3d3c2379 TH |
64 | /* managed by elevator core */ |
65 | struct kmem_cache *icq_cache; | |
66 | ||
67 | /* fields provided by elevator implementation */ | |
f9cd4bfe | 68 | struct elevator_mq_ops ops; |
a1ce35fa | 69 | |
f1f8cc94 TH |
70 | size_t icq_size; /* see iocontext.h */ |
71 | size_t icq_align; /* ditto */ | |
e572ec7e | 72 | struct elv_fs_entry *elevator_attrs; |
9305d5d7 | 73 | const char *elevator_name; |
8ac0d9a8 | 74 | const char *elevator_alias; |
68c43f13 | 75 | const unsigned int elevator_features; |
1da177e4 | 76 | struct module *elevator_owner; |
d332ce09 OS |
77 | #ifdef CONFIG_BLK_DEBUG_FS |
78 | const struct blk_mq_debugfs_attr *queue_debugfs_attrs; | |
79 | const struct blk_mq_debugfs_attr *hctx_debugfs_attrs; | |
80 | #endif | |
3d3c2379 TH |
81 | |
82 | /* managed by elevator core */ | |
9bd2bbc0 | 83 | char icq_cache_name[ELV_NAME_MAX + 6]; /* elvname + "_io_cq" */ |
22f746e2 | 84 | struct list_head list; |
1da177e4 LT |
85 | }; |
86 | ||
dd6f7f17 CH |
87 | static inline bool elevator_tryget(struct elevator_type *e) |
88 | { | |
89 | return try_module_get(e->elevator_owner); | |
90 | } | |
91 | ||
92 | static inline void __elevator_get(struct elevator_type *e) | |
93 | { | |
94 | __module_get(e->elevator_owner); | |
95 | } | |
96 | ||
97 | static inline void elevator_put(struct elevator_type *e) | |
98 | { | |
99 | module_put(e->elevator_owner); | |
100 | } | |
101 | ||
242d98f0 SL |
102 | #define ELV_HASH_BITS 6 |
103 | ||
70b3ea05 JA |
104 | void elv_rqhash_del(struct request_queue *q, struct request *rq); |
105 | void elv_rqhash_add(struct request_queue *q, struct request *rq); | |
106 | void elv_rqhash_reposition(struct request_queue *q, struct request *rq); | |
107 | struct request *elv_rqhash_find(struct request_queue *q, sector_t offset); | |
108 | ||
1da177e4 | 109 | /* |
54069588 | 110 | * each queue has an elevator_queue associated with it |
1da177e4 LT |
111 | */ |
112 | struct elevator_queue | |
113 | { | |
22f746e2 | 114 | struct elevator_type *type; |
1da177e4 LT |
115 | void *elevator_data; |
116 | struct kobject kobj; | |
3d1ab40f | 117 | struct mutex sysfs_lock; |
181d0663 | 118 | unsigned long flags; |
242d98f0 | 119 | DECLARE_HASHTABLE(hash, ELV_HASH_BITS); |
1da177e4 LT |
120 | }; |
121 | ||
671fae5e YK |
122 | #define ELEVATOR_FLAG_REGISTERED 0 |
123 | #define ELEVATOR_FLAG_DISABLE_WBT 1 | |
181d0663 | 124 | |
1da177e4 LT |
125 | /* |
126 | * block elevator interface | |
127 | */ | |
34fe7c05 CH |
128 | extern enum elv_merge elv_merge(struct request_queue *, struct request **, |
129 | struct bio *); | |
165125e1 | 130 | extern void elv_merge_requests(struct request_queue *, struct request *, |
1da177e4 | 131 | struct request *); |
34fe7c05 CH |
132 | extern void elv_merged_request(struct request_queue *, struct request *, |
133 | enum elv_merge); | |
fd2ef39c JK |
134 | extern bool elv_attempt_insert_merge(struct request_queue *, struct request *, |
135 | struct list_head *); | |
165125e1 JA |
136 | extern struct request *elv_former_request(struct request_queue *, struct request *); |
137 | extern struct request *elv_latter_request(struct request_queue *, struct request *); | |
26a9750a | 138 | void elevator_init_mq(struct request_queue *q); |
1da177e4 LT |
139 | |
140 | /* | |
141 | * io scheduler registration | |
142 | */ | |
e567bf71 | 143 | extern int elv_register(struct elevator_type *); |
1da177e4 LT |
144 | extern void elv_unregister(struct elevator_type *); |
145 | ||
146 | /* | |
147 | * io scheduler sysfs switching | |
148 | */ | |
165125e1 JA |
149 | extern ssize_t elv_iosched_show(struct request_queue *, char *); |
150 | extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t); | |
1da177e4 | 151 | |
72ef799b | 152 | extern bool elv_bio_merge_ok(struct request *, struct bio *); |
d50235b7 JM |
153 | extern struct elevator_queue *elevator_alloc(struct request_queue *, |
154 | struct elevator_type *); | |
1da177e4 | 155 | |
2e662b65 JA |
156 | /* |
157 | * Helper functions. | |
158 | */ | |
165125e1 JA |
159 | extern struct request *elv_rb_former_request(struct request_queue *, struct request *); |
160 | extern struct request *elv_rb_latter_request(struct request_queue *, struct request *); | |
2e662b65 JA |
161 | |
162 | /* | |
163 | * rb support functions. | |
164 | */ | |
796d5116 | 165 | extern void elv_rb_add(struct rb_root *, struct request *); |
2e662b65 JA |
166 | extern void elv_rb_del(struct rb_root *, struct request *); |
167 | extern struct request *elv_rb_find(struct rb_root *, sector_t); | |
168 | ||
1da177e4 LT |
169 | /* |
170 | * Insertion selection | |
171 | */ | |
172 | #define ELEVATOR_INSERT_FRONT 1 | |
173 | #define ELEVATOR_INSERT_BACK 2 | |
174 | #define ELEVATOR_INSERT_SORT 3 | |
797e7dbb | 175 | #define ELEVATOR_INSERT_REQUEUE 4 |
ae1b1539 | 176 | #define ELEVATOR_INSERT_FLUSH 5 |
5e84ea3a | 177 | #define ELEVATOR_INSERT_SORT_MERGE 6 |
1da177e4 | 178 | |
2e662b65 | 179 | #define rb_entry_rq(node) rb_entry((node), struct request, rb_node) |
1b47f531 | 180 | |
1fbfdfcd | 181 | #define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist) |
d9a74df5 | 182 | #define rq_fifo_clear(rq) list_del_init(&(rq)->queuelist) |
1fbfdfcd | 183 | |
2e9bc346 | 184 | #endif /* _ELEVATOR_H */ |