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Merge remote-tracking branch 'regulator/fix/max77802' into regulator-linus
[mirror_ubuntu-artful-kernel.git] / include / linux / elevator.h
CommitLineData
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 9struct io_cq;
d50235b7 10struct elevator_type;
d332ce09
OS
11#ifdef CONFIG_BLK_DEBUG_FS
12struct blk_mq_debugfs_attr;
13#endif
7e5a8794 14
34fe7c05
CH
15/*
16 * Return values from elevator merger
17 */
18enum 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
25typedef enum elv_merge (elevator_merge_fn) (struct request_queue *, struct request **,
1da177e4
LT
26 struct bio *);
27
165125e1 28typedef void (elevator_merge_req_fn) (struct request_queue *, struct request *, struct request *);
1da177e4 29
34fe7c05 30typedef void (elevator_merged_fn) (struct request_queue *, struct request *, enum elv_merge);
1da177e4 31
72ef799b
TE
32typedef int (elevator_allow_bio_merge_fn) (struct request_queue *,
33 struct request *, struct bio *);
34
35typedef int (elevator_allow_rq_merge_fn) (struct request_queue *,
36 struct request *, struct request *);
da775265 37
812d4026
DS
38typedef void (elevator_bio_merged_fn) (struct request_queue *,
39 struct request *, struct bio *);
40
165125e1 41typedef int (elevator_dispatch_fn) (struct request_queue *, int);
1da177e4 42
165125e1 43typedef void (elevator_add_req_fn) (struct request_queue *, struct request *);
165125e1
JA
44typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *);
45typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *);
ef295ecf 46typedef int (elevator_may_queue_fn) (struct request_queue *, unsigned int);
1da177e4 47
9b84cacd 48typedef void (elevator_init_icq_fn) (struct io_cq *);
7e5a8794 49typedef void (elevator_exit_icq_fn) (struct io_cq *);
852c788f
TH
50typedef int (elevator_set_req_fn) (struct request_queue *, struct request *,
51 struct bio *, gfp_t);
bb37b94c 52typedef void (elevator_put_req_fn) (struct request *);
165125e1
JA
53typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *);
54typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *);
1da177e4 55
d50235b7
JM
56typedef int (elevator_init_fn) (struct request_queue *,
57 struct elevator_type *e);
b374d18a 58typedef void (elevator_exit_fn) (struct elevator_queue *);
0bb97947 59typedef void (elevator_registered_fn) (struct request_queue *);
1da177e4
LT
60
61struct 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
93struct blk_mq_alloc_data;
94struct blk_mq_hw_ctx;
95
96struct 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 *);
108 void (*put_request)(struct request *);
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 (*put_rq_priv)(struct request_queue *, struct request *);
119 void (*init_icq)(struct io_cq *);
120 void (*exit_icq)(struct io_cq *);
121};
122
1da177e4
LT
123#define ELV_NAME_MAX (16)
124
e572ec7e
AV
125struct elv_fs_entry {
126 struct attribute attr;
b374d18a
JA
127 ssize_t (*show)(struct elevator_queue *, char *);
128 ssize_t (*store)(struct elevator_queue *, const char *, size_t);
e572ec7e
AV
129};
130
1da177e4
LT
131/*
132 * identifies an elevator type, such as AS or deadline
133 */
134struct elevator_type
135{
3d3c2379
TH
136 /* managed by elevator core */
137 struct kmem_cache *icq_cache;
138
139 /* fields provided by elevator implementation */
c51ca6cf
JA
140 union {
141 struct elevator_ops sq;
bd166ef1 142 struct elevator_mq_ops mq;
c51ca6cf 143 } ops;
f1f8cc94
TH
144 size_t icq_size; /* see iocontext.h */
145 size_t icq_align; /* ditto */
e572ec7e 146 struct elv_fs_entry *elevator_attrs;
1da177e4
LT
147 char elevator_name[ELV_NAME_MAX];
148 struct module *elevator_owner;
bd166ef1 149 bool uses_mq;
d332ce09
OS
150#ifdef CONFIG_BLK_DEBUG_FS
151 const struct blk_mq_debugfs_attr *queue_debugfs_attrs;
152 const struct blk_mq_debugfs_attr *hctx_debugfs_attrs;
153#endif
3d3c2379
TH
154
155 /* managed by elevator core */
9bd2bbc0 156 char icq_cache_name[ELV_NAME_MAX + 6]; /* elvname + "_io_cq" */
22f746e2 157 struct list_head list;
1da177e4
LT
158};
159
242d98f0
SL
160#define ELV_HASH_BITS 6
161
70b3ea05
JA
162void elv_rqhash_del(struct request_queue *q, struct request *rq);
163void elv_rqhash_add(struct request_queue *q, struct request *rq);
164void elv_rqhash_reposition(struct request_queue *q, struct request *rq);
165struct request *elv_rqhash_find(struct request_queue *q, sector_t offset);
166
1da177e4 167/*
54069588 168 * each queue has an elevator_queue associated with it
1da177e4
LT
169 */
170struct elevator_queue
171{
22f746e2 172 struct elevator_type *type;
1da177e4
LT
173 void *elevator_data;
174 struct kobject kobj;
3d1ab40f 175 struct mutex sysfs_lock;
430c62fb 176 unsigned int registered:1;
bd166ef1 177 unsigned int uses_mq:1;
242d98f0 178 DECLARE_HASHTABLE(hash, ELV_HASH_BITS);
1da177e4
LT
179};
180
181/*
182 * block elevator interface
183 */
165125e1
JA
184extern void elv_dispatch_sort(struct request_queue *, struct request *);
185extern void elv_dispatch_add_tail(struct request_queue *, struct request *);
7eaceacc
JA
186extern void elv_add_request(struct request_queue *, struct request *, int);
187extern void __elv_add_request(struct request_queue *, struct request *, int);
34fe7c05
CH
188extern enum elv_merge elv_merge(struct request_queue *, struct request **,
189 struct bio *);
165125e1 190extern void elv_merge_requests(struct request_queue *, struct request *,
1da177e4 191 struct request *);
34fe7c05
CH
192extern void elv_merged_request(struct request_queue *, struct request *,
193 enum elv_merge);
812d4026
DS
194extern void elv_bio_merged(struct request_queue *q, struct request *,
195 struct bio *);
bd166ef1 196extern bool elv_attempt_insert_merge(struct request_queue *, struct request *);
165125e1 197extern void elv_requeue_request(struct request_queue *, struct request *);
165125e1
JA
198extern struct request *elv_former_request(struct request_queue *, struct request *);
199extern struct request *elv_latter_request(struct request_queue *, struct request *);
200extern int elv_register_queue(struct request_queue *q);
201extern void elv_unregister_queue(struct request_queue *q);
ef295ecf 202extern int elv_may_queue(struct request_queue *, unsigned int);
165125e1 203extern void elv_completed_request(struct request_queue *, struct request *);
852c788f
TH
204extern int elv_set_request(struct request_queue *q, struct request *rq,
205 struct bio *bio, gfp_t gfp_mask);
165125e1 206extern void elv_put_request(struct request_queue *, struct request *);
26308eab 207extern void elv_drain_elevator(struct request_queue *);
1da177e4
LT
208
209/*
210 * io scheduler registration
211 */
bb813f4c 212extern void __init load_default_elevator_module(void);
e567bf71 213extern int elv_register(struct elevator_type *);
1da177e4
LT
214extern void elv_unregister(struct elevator_type *);
215
216/*
217 * io scheduler sysfs switching
218 */
165125e1
JA
219extern ssize_t elv_iosched_show(struct request_queue *, char *);
220extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t);
1da177e4 221
165125e1 222extern int elevator_init(struct request_queue *, char *);
54d5329d 223extern void elevator_exit(struct request_queue *, struct elevator_queue *);
72ef799b 224extern bool elv_bio_merge_ok(struct request *, struct bio *);
d50235b7
JM
225extern struct elevator_queue *elevator_alloc(struct request_queue *,
226 struct elevator_type *);
1da177e4 227
2e662b65
JA
228/*
229 * Helper functions.
230 */
165125e1
JA
231extern struct request *elv_rb_former_request(struct request_queue *, struct request *);
232extern struct request *elv_rb_latter_request(struct request_queue *, struct request *);
2e662b65
JA
233
234/*
235 * rb support functions.
236 */
796d5116 237extern void elv_rb_add(struct rb_root *, struct request *);
2e662b65
JA
238extern void elv_rb_del(struct rb_root *, struct request *);
239extern struct request *elv_rb_find(struct rb_root *, sector_t);
240
1da177e4
LT
241/*
242 * Insertion selection
243 */
244#define ELEVATOR_INSERT_FRONT 1
245#define ELEVATOR_INSERT_BACK 2
246#define ELEVATOR_INSERT_SORT 3
797e7dbb 247#define ELEVATOR_INSERT_REQUEUE 4
ae1b1539 248#define ELEVATOR_INSERT_FLUSH 5
5e84ea3a 249#define ELEVATOR_INSERT_SORT_MERGE 6
1da177e4
LT
250
251/*
252 * return values from elevator_may_queue_fn
253 */
254enum {
255 ELV_MQUEUE_MAY,
256 ELV_MQUEUE_NO,
257 ELV_MQUEUE_MUST,
258};
259
2e46e8b2 260#define rq_end_sector(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq))
2e662b65 261#define rb_entry_rq(node) rb_entry((node), struct request, rb_node)
1b47f531 262
1fbfdfcd 263#define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist)
d9a74df5 264#define rq_fifo_clear(rq) list_del_init(&(rq)->queuelist)
1fbfdfcd 265
bb813f4c
TH
266#else /* CONFIG_BLOCK */
267
268static inline void load_default_elevator_module(void) { }
269
9361401e 270#endif /* CONFIG_BLOCK */
1da177e4 271#endif