Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _LINUX_ELEVATOR_H |
| 2 | #define _LINUX_ELEVATOR_H |
| 3 | |
Jens Axboe | 4a893e8 | 2006-07-22 15:37:43 +0200 | [diff] [blame] | 4 | #include <linux/percpu.h> |
| 5 | |
David Howells | 9361401 | 2006-09-30 20:45:40 +0200 | [diff] [blame] | 6 | #ifdef CONFIG_BLOCK |
| 7 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 8 | typedef int (elevator_merge_fn) (struct request_queue *, struct request **, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | struct bio *); |
| 10 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 11 | typedef void (elevator_merge_req_fn) (struct request_queue *, struct request *, struct request *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 13 | typedef void (elevator_merged_fn) (struct request_queue *, struct request *, int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 15 | typedef int (elevator_allow_merge_fn) (struct request_queue *, struct request *, struct bio *); |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 16 | |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 17 | typedef void (elevator_bio_merged_fn) (struct request_queue *, |
| 18 | struct request *, struct bio *); |
| 19 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 20 | typedef int (elevator_dispatch_fn) (struct request_queue *, int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 22 | typedef void (elevator_add_req_fn) (struct request_queue *, struct request *); |
| 23 | typedef int (elevator_queue_empty_fn) (struct request_queue *); |
| 24 | typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *); |
| 25 | typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *); |
| 26 | typedef int (elevator_may_queue_fn) (struct request_queue *, int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 28 | typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, gfp_t); |
Jens Axboe | bb37b94 | 2006-12-01 10:42:33 +0100 | [diff] [blame] | 29 | typedef void (elevator_put_req_fn) (struct request *); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 30 | typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *); |
| 31 | typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 33 | typedef void *(elevator_init_fn) (struct request_queue *); |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 34 | typedef void (elevator_exit_fn) (struct elevator_queue *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
| 36 | struct elevator_ops |
| 37 | { |
| 38 | elevator_merge_fn *elevator_merge_fn; |
| 39 | elevator_merged_fn *elevator_merged_fn; |
| 40 | elevator_merge_req_fn *elevator_merge_req_fn; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 41 | elevator_allow_merge_fn *elevator_allow_merge_fn; |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 42 | elevator_bio_merged_fn *elevator_bio_merged_fn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 44 | elevator_dispatch_fn *elevator_dispatch_fn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | elevator_add_req_fn *elevator_add_req_fn; |
Tejun Heo | 8922e16 | 2005-10-20 16:23:44 +0200 | [diff] [blame] | 46 | elevator_activate_req_fn *elevator_activate_req_fn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | elevator_deactivate_req_fn *elevator_deactivate_req_fn; |
| 48 | |
| 49 | elevator_queue_empty_fn *elevator_queue_empty_fn; |
| 50 | elevator_completed_req_fn *elevator_completed_req_fn; |
| 51 | |
| 52 | elevator_request_list_fn *elevator_former_req_fn; |
| 53 | elevator_request_list_fn *elevator_latter_req_fn; |
| 54 | |
| 55 | elevator_set_req_fn *elevator_set_req_fn; |
| 56 | elevator_put_req_fn *elevator_put_req_fn; |
| 57 | |
| 58 | elevator_may_queue_fn *elevator_may_queue_fn; |
| 59 | |
| 60 | elevator_init_fn *elevator_init_fn; |
| 61 | elevator_exit_fn *elevator_exit_fn; |
Al Viro | e17a948 | 2006-03-18 13:21:20 -0500 | [diff] [blame] | 62 | void (*trim)(struct io_context *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | }; |
| 64 | |
| 65 | #define ELV_NAME_MAX (16) |
| 66 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 67 | struct elv_fs_entry { |
| 68 | struct attribute attr; |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 69 | ssize_t (*show)(struct elevator_queue *, char *); |
| 70 | ssize_t (*store)(struct elevator_queue *, const char *, size_t); |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 71 | }; |
| 72 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | /* |
| 74 | * identifies an elevator type, such as AS or deadline |
| 75 | */ |
| 76 | struct elevator_type |
| 77 | { |
| 78 | struct list_head list; |
| 79 | struct elevator_ops ops; |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 80 | struct elv_fs_entry *elevator_attrs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | char elevator_name[ELV_NAME_MAX]; |
| 82 | struct module *elevator_owner; |
| 83 | }; |
| 84 | |
| 85 | /* |
Adrian Bunk | 5406958 | 2006-01-10 00:09:36 +0100 | [diff] [blame] | 86 | * each queue has an elevator_queue associated with it |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | */ |
| 88 | struct elevator_queue |
| 89 | { |
| 90 | struct elevator_ops *ops; |
| 91 | void *elevator_data; |
| 92 | struct kobject kobj; |
| 93 | struct elevator_type *elevator_type; |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 94 | struct mutex sysfs_lock; |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 95 | struct hlist_head *hash; |
Jens Axboe | 430c62f | 2010-10-07 09:35:16 +0200 | [diff] [blame^] | 96 | unsigned int registered:1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | }; |
| 98 | |
| 99 | /* |
| 100 | * block elevator interface |
| 101 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 102 | extern void elv_dispatch_sort(struct request_queue *, struct request *); |
| 103 | extern void elv_dispatch_add_tail(struct request_queue *, struct request *); |
| 104 | extern void elv_add_request(struct request_queue *, struct request *, int, int); |
| 105 | extern void __elv_add_request(struct request_queue *, struct request *, int, int); |
| 106 | extern void elv_insert(struct request_queue *, struct request *, int); |
| 107 | extern int elv_merge(struct request_queue *, struct request **, struct bio *); |
| 108 | extern void elv_merge_requests(struct request_queue *, struct request *, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | struct request *); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 110 | extern void elv_merged_request(struct request_queue *, struct request *, int); |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 111 | extern void elv_bio_merged(struct request_queue *q, struct request *, |
| 112 | struct bio *); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 113 | extern void elv_requeue_request(struct request_queue *, struct request *); |
| 114 | extern int elv_queue_empty(struct request_queue *); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 115 | extern struct request *elv_former_request(struct request_queue *, struct request *); |
| 116 | extern struct request *elv_latter_request(struct request_queue *, struct request *); |
| 117 | extern int elv_register_queue(struct request_queue *q); |
| 118 | extern void elv_unregister_queue(struct request_queue *q); |
| 119 | extern int elv_may_queue(struct request_queue *, int); |
Mike Anderson | 11914a5 | 2008-09-13 20:31:27 +0200 | [diff] [blame] | 120 | extern void elv_abort_queue(struct request_queue *); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 121 | extern void elv_completed_request(struct request_queue *, struct request *); |
| 122 | extern int elv_set_request(struct request_queue *, struct request *, gfp_t); |
| 123 | extern void elv_put_request(struct request_queue *, struct request *); |
Jerome Marchand | 26308ea | 2009-03-27 10:31:51 +0100 | [diff] [blame] | 124 | extern void elv_drain_elevator(struct request_queue *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | |
| 126 | /* |
| 127 | * io scheduler registration |
| 128 | */ |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 129 | extern void elv_register(struct elevator_type *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | extern void elv_unregister(struct elevator_type *); |
| 131 | |
| 132 | /* |
| 133 | * io scheduler sysfs switching |
| 134 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 135 | extern ssize_t elv_iosched_show(struct request_queue *, char *); |
| 136 | extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 138 | extern int elevator_init(struct request_queue *, char *); |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 139 | extern void elevator_exit(struct elevator_queue *); |
Jens Axboe | 5dd531a | 2010-08-23 13:52:19 +0200 | [diff] [blame] | 140 | extern int elevator_change(struct request_queue *, const char *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | extern int elv_rq_merge_ok(struct request *, struct bio *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | |
| 143 | /* |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 144 | * Helper functions. |
| 145 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 146 | extern struct request *elv_rb_former_request(struct request_queue *, struct request *); |
| 147 | extern struct request *elv_rb_latter_request(struct request_queue *, struct request *); |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 148 | |
| 149 | /* |
| 150 | * rb support functions. |
| 151 | */ |
| 152 | extern struct request *elv_rb_add(struct rb_root *, struct request *); |
| 153 | extern void elv_rb_del(struct rb_root *, struct request *); |
| 154 | extern struct request *elv_rb_find(struct rb_root *, sector_t); |
| 155 | |
| 156 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | * Return values from elevator merger |
| 158 | */ |
| 159 | #define ELEVATOR_NO_MERGE 0 |
| 160 | #define ELEVATOR_FRONT_MERGE 1 |
| 161 | #define ELEVATOR_BACK_MERGE 2 |
| 162 | |
| 163 | /* |
| 164 | * Insertion selection |
| 165 | */ |
| 166 | #define ELEVATOR_INSERT_FRONT 1 |
| 167 | #define ELEVATOR_INSERT_BACK 2 |
| 168 | #define ELEVATOR_INSERT_SORT 3 |
Tejun Heo | 797e7db | 2006-01-06 09:51:03 +0100 | [diff] [blame] | 169 | #define ELEVATOR_INSERT_REQUEUE 4 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | |
| 171 | /* |
| 172 | * return values from elevator_may_queue_fn |
| 173 | */ |
| 174 | enum { |
| 175 | ELV_MQUEUE_MAY, |
| 176 | ELV_MQUEUE_NO, |
| 177 | ELV_MQUEUE_MUST, |
| 178 | }; |
| 179 | |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 180 | #define rq_end_sector(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq)) |
Jens Axboe | 2e662b6 | 2006-07-13 11:55:04 +0200 | [diff] [blame] | 181 | #define rb_entry_rq(node) rb_entry((node), struct request, rb_node) |
Jens Axboe | 1b47f53 | 2005-10-20 16:37:00 +0200 | [diff] [blame] | 182 | |
Jens Axboe | 1fbfdfc | 2006-07-11 21:49:15 +0200 | [diff] [blame] | 183 | /* |
Jens Axboe | c7c22e4 | 2008-09-13 20:26:01 +0200 | [diff] [blame] | 184 | * Hack to reuse the csd.list list_head as the fifo time holder while |
Jens Axboe | 1fbfdfc | 2006-07-11 21:49:15 +0200 | [diff] [blame] | 185 | * the request is in the io scheduler. Saves an unsigned long in rq. |
| 186 | */ |
Jens Axboe | c7c22e4 | 2008-09-13 20:26:01 +0200 | [diff] [blame] | 187 | #define rq_fifo_time(rq) ((unsigned long) (rq)->csd.list.next) |
| 188 | #define rq_set_fifo_time(rq,exp) ((rq)->csd.list.next = (void *) (exp)) |
Jens Axboe | 1fbfdfc | 2006-07-11 21:49:15 +0200 | [diff] [blame] | 189 | #define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist) |
| 190 | #define rq_fifo_clear(rq) do { \ |
| 191 | list_del_init(&(rq)->queuelist); \ |
Jens Axboe | c7c22e4 | 2008-09-13 20:26:01 +0200 | [diff] [blame] | 192 | INIT_LIST_HEAD(&(rq)->csd.list); \ |
Jens Axboe | 1fbfdfc | 2006-07-11 21:49:15 +0200 | [diff] [blame] | 193 | } while (0) |
| 194 | |
Jens Axboe | 4a893e8 | 2006-07-22 15:37:43 +0200 | [diff] [blame] | 195 | /* |
| 196 | * io context count accounting |
| 197 | */ |
| 198 | #define elv_ioc_count_mod(name, __val) \ |
| 199 | do { \ |
| 200 | preempt_disable(); \ |
| 201 | __get_cpu_var(name) += (__val); \ |
| 202 | preempt_enable(); \ |
| 203 | } while (0) |
| 204 | |
| 205 | #define elv_ioc_count_inc(name) elv_ioc_count_mod(name, 1) |
| 206 | #define elv_ioc_count_dec(name) elv_ioc_count_mod(name, -1) |
| 207 | |
| 208 | #define elv_ioc_count_read(name) \ |
| 209 | ({ \ |
| 210 | unsigned long __val = 0; \ |
| 211 | int __cpu; \ |
| 212 | smp_wmb(); \ |
| 213 | for_each_possible_cpu(__cpu) \ |
| 214 | __val += per_cpu(name, __cpu); \ |
| 215 | __val; \ |
| 216 | }) |
| 217 | |
David Howells | 9361401 | 2006-09-30 20:45:40 +0200 | [diff] [blame] | 218 | #endif /* CONFIG_BLOCK */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | #endif |