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1da177e4 LT |
1 | #ifndef _LINUX_BLKDEV_H |
2 | #define _LINUX_BLKDEV_H | |
3 | ||
4 | #include <linux/config.h> | |
5 | #include <linux/major.h> | |
6 | #include <linux/genhd.h> | |
7 | #include <linux/list.h> | |
8 | #include <linux/timer.h> | |
9 | #include <linux/workqueue.h> | |
10 | #include <linux/pagemap.h> | |
11 | #include <linux/backing-dev.h> | |
12 | #include <linux/wait.h> | |
13 | #include <linux/mempool.h> | |
14 | #include <linux/bio.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/stringify.h> | |
17 | ||
18 | #include <asm/scatterlist.h> | |
19 | ||
20 | struct request_queue; | |
21 | typedef struct request_queue request_queue_t; | |
22 | struct elevator_queue; | |
23 | typedef struct elevator_queue elevator_t; | |
24 | struct request_pm_state; | |
25 | ||
26 | #define BLKDEV_MIN_RQ 4 | |
27 | #define BLKDEV_MAX_RQ 128 /* Default maximum */ | |
28 | ||
29 | /* | |
30 | * This is the per-process anticipatory I/O scheduler state. | |
31 | */ | |
32 | struct as_io_context { | |
33 | spinlock_t lock; | |
34 | ||
35 | void (*dtor)(struct as_io_context *aic); /* destructor */ | |
36 | void (*exit)(struct as_io_context *aic); /* called on task exit */ | |
37 | ||
38 | unsigned long state; | |
39 | atomic_t nr_queued; /* queued reads & sync writes */ | |
40 | atomic_t nr_dispatched; /* number of requests gone to the drivers */ | |
41 | ||
42 | /* IO History tracking */ | |
43 | /* Thinktime */ | |
44 | unsigned long last_end_request; | |
45 | unsigned long ttime_total; | |
46 | unsigned long ttime_samples; | |
47 | unsigned long ttime_mean; | |
48 | /* Layout pattern */ | |
49 | unsigned int seek_samples; | |
50 | sector_t last_request_pos; | |
51 | u64 seek_total; | |
52 | sector_t seek_mean; | |
53 | }; | |
54 | ||
55 | struct cfq_queue; | |
56 | struct cfq_io_context { | |
1da177e4 LT |
57 | /* |
58 | * circular list of cfq_io_contexts belonging to a process io context | |
59 | */ | |
60 | struct list_head list; | |
61 | struct cfq_queue *cfqq; | |
22e2c507 JA |
62 | void *key; |
63 | ||
64 | struct io_context *ioc; | |
65 | ||
66 | unsigned long last_end_request; | |
67 | unsigned long last_queue; | |
68 | unsigned long ttime_total; | |
69 | unsigned long ttime_samples; | |
70 | unsigned long ttime_mean; | |
71 | ||
72 | void (*dtor)(struct cfq_io_context *); | |
73 | void (*exit)(struct cfq_io_context *); | |
1da177e4 LT |
74 | }; |
75 | ||
76 | /* | |
77 | * This is the per-process I/O subsystem state. It is refcounted and | |
78 | * kmalloc'ed. Currently all fields are modified in process io context | |
79 | * (apart from the atomic refcount), so require no locking. | |
80 | */ | |
81 | struct io_context { | |
82 | atomic_t refcount; | |
22e2c507 JA |
83 | struct task_struct *task; |
84 | ||
85 | int (*set_ioprio)(struct io_context *, unsigned int); | |
1da177e4 LT |
86 | |
87 | /* | |
88 | * For request batching | |
89 | */ | |
90 | unsigned long last_waited; /* Time last woken after wait for request */ | |
91 | int nr_batch_requests; /* Number of requests left in the batch */ | |
92 | ||
1da177e4 LT |
93 | struct as_io_context *aic; |
94 | struct cfq_io_context *cic; | |
95 | }; | |
96 | ||
97 | void put_io_context(struct io_context *ioc); | |
98 | void exit_io_context(void); | |
8267e268 AV |
99 | struct io_context *current_io_context(gfp_t gfp_flags); |
100 | struct io_context *get_io_context(gfp_t gfp_flags); | |
1da177e4 LT |
101 | void copy_io_context(struct io_context **pdst, struct io_context **psrc); |
102 | void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); | |
103 | ||
104 | struct request; | |
8ffdc655 | 105 | typedef void (rq_end_io_fn)(struct request *, int); |
1da177e4 LT |
106 | |
107 | struct request_list { | |
108 | int count[2]; | |
109 | int starved[2]; | |
cb98fc8b | 110 | int elvpriv; |
1da177e4 LT |
111 | mempool_t *rq_pool; |
112 | wait_queue_head_t wait[2]; | |
1da177e4 LT |
113 | }; |
114 | ||
115 | #define BLK_MAX_CDB 16 | |
116 | ||
117 | /* | |
118 | * try to put the fields that are referenced together in the same cacheline | |
119 | */ | |
120 | struct request { | |
121 | struct list_head queuelist; /* looking for ->queue? you must _not_ | |
122 | * access it directly, use | |
123 | * blkdev_dequeue_request! */ | |
124 | unsigned long flags; /* see REQ_ bits below */ | |
125 | ||
126 | /* Maintain bio traversal state for part by part I/O submission. | |
127 | * hard_* are block layer internals, no driver should touch them! | |
128 | */ | |
129 | ||
130 | sector_t sector; /* next sector to submit */ | |
131 | unsigned long nr_sectors; /* no. of sectors left to submit */ | |
132 | /* no. of sectors left to submit in the current segment */ | |
133 | unsigned int current_nr_sectors; | |
134 | ||
135 | sector_t hard_sector; /* next sector to complete */ | |
136 | unsigned long hard_nr_sectors; /* no. of sectors left to complete */ | |
137 | /* no. of sectors left to complete in the current segment */ | |
138 | unsigned int hard_cur_sectors; | |
139 | ||
140 | struct bio *bio; | |
141 | struct bio *biotail; | |
142 | ||
143 | void *elevator_private; | |
144 | ||
22e2c507 JA |
145 | unsigned short ioprio; |
146 | ||
1da177e4 LT |
147 | int rq_status; /* should split this into a few status bits */ |
148 | struct gendisk *rq_disk; | |
149 | int errors; | |
150 | unsigned long start_time; | |
151 | ||
152 | /* Number of scatter-gather DMA addr+len pairs after | |
153 | * physical address coalescing is performed. | |
154 | */ | |
155 | unsigned short nr_phys_segments; | |
156 | ||
157 | /* Number of scatter-gather addr+len pairs after | |
158 | * physical and DMA remapping hardware coalescing is performed. | |
159 | * This is the number of scatter-gather entries the driver | |
160 | * will actually have to deal with after DMA mapping is done. | |
161 | */ | |
162 | unsigned short nr_hw_segments; | |
163 | ||
164 | int tag; | |
165 | char *buffer; | |
166 | ||
167 | int ref_count; | |
168 | request_queue_t *q; | |
169 | struct request_list *rl; | |
170 | ||
171 | struct completion *waiting; | |
172 | void *special; | |
173 | ||
174 | /* | |
175 | * when request is used as a packet command carrier | |
176 | */ | |
177 | unsigned int cmd_len; | |
178 | unsigned char cmd[BLK_MAX_CDB]; | |
179 | ||
180 | unsigned int data_len; | |
181 | void *data; | |
182 | ||
183 | unsigned int sense_len; | |
184 | void *sense; | |
185 | ||
186 | unsigned int timeout; | |
17e01f21 | 187 | int retries; |
1da177e4 LT |
188 | |
189 | /* | |
190 | * For Power Management requests | |
191 | */ | |
192 | struct request_pm_state *pm; | |
193 | ||
194 | /* | |
195 | * completion callback. end_io_data should be folded in with waiting | |
196 | */ | |
197 | rq_end_io_fn *end_io; | |
198 | void *end_io_data; | |
199 | }; | |
200 | ||
201 | /* | |
202 | * first three bits match BIO_RW* bits, important | |
203 | */ | |
204 | enum rq_flag_bits { | |
205 | __REQ_RW, /* not set, read. set, write */ | |
206 | __REQ_FAILFAST, /* no low level driver retries */ | |
8922e16c | 207 | __REQ_SORTED, /* elevator knows about this request */ |
1da177e4 LT |
208 | __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ |
209 | __REQ_HARDBARRIER, /* may not be passed by drive either */ | |
797e7dbb | 210 | __REQ_FUA, /* forced unit access */ |
1da177e4 LT |
211 | __REQ_CMD, /* is a regular fs rw request */ |
212 | __REQ_NOMERGE, /* don't touch this for merging */ | |
213 | __REQ_STARTED, /* drive already may have started this one */ | |
214 | __REQ_DONTPREP, /* don't call prep for this one */ | |
215 | __REQ_QUEUED, /* uses queueing */ | |
cb98fc8b | 216 | __REQ_ELVPRIV, /* elevator private data attached */ |
1da177e4 LT |
217 | /* |
218 | * for ATA/ATAPI devices | |
219 | */ | |
220 | __REQ_PC, /* packet command (special) */ | |
221 | __REQ_BLOCK_PC, /* queued down pc from block layer */ | |
222 | __REQ_SENSE, /* sense retrival */ | |
223 | ||
224 | __REQ_FAILED, /* set if the request failed */ | |
225 | __REQ_QUIET, /* don't worry about errors */ | |
226 | __REQ_SPECIAL, /* driver suplied command */ | |
227 | __REQ_DRIVE_CMD, | |
228 | __REQ_DRIVE_TASK, | |
229 | __REQ_DRIVE_TASKFILE, | |
230 | __REQ_PREEMPT, /* set for "ide_preempt" requests */ | |
231 | __REQ_PM_SUSPEND, /* suspend request */ | |
232 | __REQ_PM_RESUME, /* resume request */ | |
233 | __REQ_PM_SHUTDOWN, /* shutdown request */ | |
797e7dbb | 234 | __REQ_ORDERED_COLOR, /* is before or after barrier */ |
1da177e4 LT |
235 | __REQ_NR_BITS, /* stops here */ |
236 | }; | |
237 | ||
238 | #define REQ_RW (1 << __REQ_RW) | |
239 | #define REQ_FAILFAST (1 << __REQ_FAILFAST) | |
8922e16c | 240 | #define REQ_SORTED (1 << __REQ_SORTED) |
1da177e4 LT |
241 | #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) |
242 | #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) | |
797e7dbb | 243 | #define REQ_FUA (1 << __REQ_FUA) |
1da177e4 LT |
244 | #define REQ_CMD (1 << __REQ_CMD) |
245 | #define REQ_NOMERGE (1 << __REQ_NOMERGE) | |
246 | #define REQ_STARTED (1 << __REQ_STARTED) | |
247 | #define REQ_DONTPREP (1 << __REQ_DONTPREP) | |
248 | #define REQ_QUEUED (1 << __REQ_QUEUED) | |
cb98fc8b | 249 | #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) |
1da177e4 LT |
250 | #define REQ_PC (1 << __REQ_PC) |
251 | #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC) | |
252 | #define REQ_SENSE (1 << __REQ_SENSE) | |
253 | #define REQ_FAILED (1 << __REQ_FAILED) | |
254 | #define REQ_QUIET (1 << __REQ_QUIET) | |
255 | #define REQ_SPECIAL (1 << __REQ_SPECIAL) | |
256 | #define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD) | |
257 | #define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK) | |
258 | #define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE) | |
259 | #define REQ_PREEMPT (1 << __REQ_PREEMPT) | |
260 | #define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND) | |
261 | #define REQ_PM_RESUME (1 << __REQ_PM_RESUME) | |
262 | #define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN) | |
797e7dbb | 263 | #define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR) |
1da177e4 LT |
264 | |
265 | /* | |
266 | * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME | |
267 | * requests. Some step values could eventually be made generic. | |
268 | */ | |
269 | struct request_pm_state | |
270 | { | |
271 | /* PM state machine step value, currently driver specific */ | |
272 | int pm_step; | |
273 | /* requested PM state value (S1, S2, S3, S4, ...) */ | |
274 | u32 pm_state; | |
275 | void* data; /* for driver use */ | |
276 | }; | |
277 | ||
278 | #include <linux/elevator.h> | |
279 | ||
280 | typedef int (merge_request_fn) (request_queue_t *, struct request *, | |
281 | struct bio *); | |
282 | typedef int (merge_requests_fn) (request_queue_t *, struct request *, | |
283 | struct request *); | |
284 | typedef void (request_fn_proc) (request_queue_t *q); | |
285 | typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); | |
286 | typedef int (prep_rq_fn) (request_queue_t *, struct request *); | |
287 | typedef void (unplug_fn) (request_queue_t *); | |
288 | ||
289 | struct bio_vec; | |
290 | typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); | |
291 | typedef void (activity_fn) (void *data, int rw); | |
292 | typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); | |
797e7dbb | 293 | typedef void (prepare_flush_fn) (request_queue_t *, struct request *); |
1da177e4 LT |
294 | |
295 | enum blk_queue_state { | |
296 | Queue_down, | |
297 | Queue_up, | |
298 | }; | |
299 | ||
1da177e4 LT |
300 | struct blk_queue_tag { |
301 | struct request **tag_index; /* map of busy tags */ | |
302 | unsigned long *tag_map; /* bit map of free/busy tags */ | |
303 | struct list_head busy_list; /* fifo list of busy tags */ | |
304 | int busy; /* current depth */ | |
305 | int max_depth; /* what we will send to device */ | |
ba025082 | 306 | int real_max_depth; /* what the array can hold */ |
1da177e4 LT |
307 | atomic_t refcnt; /* map can be shared */ |
308 | }; | |
309 | ||
310 | struct request_queue | |
311 | { | |
312 | /* | |
313 | * Together with queue_head for cacheline sharing | |
314 | */ | |
315 | struct list_head queue_head; | |
316 | struct request *last_merge; | |
317 | elevator_t *elevator; | |
318 | ||
319 | /* | |
320 | * the queue request freelist, one for reads and one for writes | |
321 | */ | |
322 | struct request_list rq; | |
323 | ||
324 | request_fn_proc *request_fn; | |
325 | merge_request_fn *back_merge_fn; | |
326 | merge_request_fn *front_merge_fn; | |
327 | merge_requests_fn *merge_requests_fn; | |
328 | make_request_fn *make_request_fn; | |
329 | prep_rq_fn *prep_rq_fn; | |
330 | unplug_fn *unplug_fn; | |
331 | merge_bvec_fn *merge_bvec_fn; | |
332 | activity_fn *activity_fn; | |
333 | issue_flush_fn *issue_flush_fn; | |
334 | prepare_flush_fn *prepare_flush_fn; | |
1da177e4 | 335 | |
8922e16c TH |
336 | /* |
337 | * Dispatch queue sorting | |
338 | */ | |
1b47f531 | 339 | sector_t end_sector; |
8922e16c | 340 | struct request *boundary_rq; |
8922e16c | 341 | |
1da177e4 LT |
342 | /* |
343 | * Auto-unplugging state | |
344 | */ | |
345 | struct timer_list unplug_timer; | |
346 | int unplug_thresh; /* After this many requests */ | |
347 | unsigned long unplug_delay; /* After this many jiffies */ | |
348 | struct work_struct unplug_work; | |
349 | ||
350 | struct backing_dev_info backing_dev_info; | |
351 | ||
352 | /* | |
353 | * The queue owner gets to use this for whatever they like. | |
354 | * ll_rw_blk doesn't touch it. | |
355 | */ | |
356 | void *queuedata; | |
357 | ||
358 | void *activity_data; | |
359 | ||
360 | /* | |
361 | * queue needs bounce pages for pages above this limit | |
362 | */ | |
363 | unsigned long bounce_pfn; | |
8267e268 | 364 | gfp_t bounce_gfp; |
1da177e4 LT |
365 | |
366 | /* | |
367 | * various queue flags, see QUEUE_* below | |
368 | */ | |
369 | unsigned long queue_flags; | |
370 | ||
371 | /* | |
152587de JA |
372 | * protects queue structures from reentrancy. ->__queue_lock should |
373 | * _never_ be used directly, it is queue private. always use | |
374 | * ->queue_lock. | |
1da177e4 | 375 | */ |
152587de | 376 | spinlock_t __queue_lock; |
1da177e4 LT |
377 | spinlock_t *queue_lock; |
378 | ||
379 | /* | |
380 | * queue kobject | |
381 | */ | |
382 | struct kobject kobj; | |
383 | ||
384 | /* | |
385 | * queue settings | |
386 | */ | |
387 | unsigned long nr_requests; /* Max # of requests */ | |
388 | unsigned int nr_congestion_on; | |
389 | unsigned int nr_congestion_off; | |
390 | unsigned int nr_batching; | |
391 | ||
392 | unsigned short max_sectors; | |
393 | unsigned short max_hw_sectors; | |
394 | unsigned short max_phys_segments; | |
395 | unsigned short max_hw_segments; | |
396 | unsigned short hardsect_size; | |
397 | unsigned int max_segment_size; | |
398 | ||
399 | unsigned long seg_boundary_mask; | |
400 | unsigned int dma_alignment; | |
401 | ||
402 | struct blk_queue_tag *queue_tags; | |
403 | ||
404 | atomic_t refcnt; | |
405 | ||
15853af9 | 406 | unsigned int nr_sorted; |
1da177e4 LT |
407 | unsigned int in_flight; |
408 | ||
409 | /* | |
410 | * sg stuff | |
411 | */ | |
412 | unsigned int sg_timeout; | |
413 | unsigned int sg_reserved_size; | |
1946089a | 414 | int node; |
1da177e4 | 415 | |
1da177e4 LT |
416 | /* |
417 | * reserved for flush operations | |
418 | */ | |
797e7dbb TH |
419 | unsigned int ordered, next_ordered, ordseq; |
420 | int orderr, ordcolor; | |
421 | struct request pre_flush_rq, bar_rq, post_flush_rq; | |
422 | struct request *orig_bar_rq; | |
423 | unsigned int bi_size; | |
1da177e4 LT |
424 | }; |
425 | ||
426 | #define RQ_INACTIVE (-1) | |
427 | #define RQ_ACTIVE 1 | |
428 | #define RQ_SCSI_BUSY 0xffff | |
429 | #define RQ_SCSI_DONE 0xfffe | |
430 | #define RQ_SCSI_DISCONNECTING 0xffe0 | |
431 | ||
432 | #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ | |
433 | #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ | |
434 | #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ | |
435 | #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */ | |
436 | #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */ | |
437 | #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ | |
438 | #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ | |
439 | #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ | |
64521d1a | 440 | #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ |
797e7dbb TH |
441 | |
442 | enum { | |
443 | /* | |
444 | * Hardbarrier is supported with one of the following methods. | |
445 | * | |
446 | * NONE : hardbarrier unsupported | |
447 | * DRAIN : ordering by draining is enough | |
448 | * DRAIN_FLUSH : ordering by draining w/ pre and post flushes | |
449 | * DRAIN_FUA : ordering by draining w/ pre flush and FUA write | |
450 | * TAG : ordering by tag is enough | |
451 | * TAG_FLUSH : ordering by tag w/ pre and post flushes | |
452 | * TAG_FUA : ordering by tag w/ pre flush and FUA write | |
453 | */ | |
454 | QUEUE_ORDERED_NONE = 0x00, | |
455 | QUEUE_ORDERED_DRAIN = 0x01, | |
456 | QUEUE_ORDERED_TAG = 0x02, | |
457 | ||
458 | QUEUE_ORDERED_PREFLUSH = 0x10, | |
459 | QUEUE_ORDERED_POSTFLUSH = 0x20, | |
460 | QUEUE_ORDERED_FUA = 0x40, | |
461 | ||
462 | QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN | | |
463 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
464 | QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN | | |
465 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
466 | QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG | | |
467 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH, | |
468 | QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG | | |
469 | QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA, | |
470 | ||
471 | /* | |
472 | * Ordered operation sequence | |
473 | */ | |
474 | QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */ | |
475 | QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */ | |
476 | QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */ | |
477 | QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */ | |
478 | QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */ | |
479 | QUEUE_ORDSEQ_DONE = 0x20, | |
480 | }; | |
1da177e4 LT |
481 | |
482 | #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) | |
483 | #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) | |
484 | #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) | |
797e7dbb | 485 | #define blk_queue_flushing(q) ((q)->ordseq) |
1da177e4 LT |
486 | |
487 | #define blk_fs_request(rq) ((rq)->flags & REQ_CMD) | |
488 | #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC) | |
489 | #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST) | |
490 | #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED) | |
491 | ||
492 | #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) | |
493 | ||
494 | #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND) | |
495 | #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME) | |
496 | #define blk_pm_request(rq) \ | |
497 | ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME)) | |
498 | ||
8922e16c | 499 | #define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED) |
1da177e4 | 500 | #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER) |
797e7dbb | 501 | #define blk_fua_rq(rq) ((rq)->flags & REQ_FUA) |
1da177e4 LT |
502 | |
503 | #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) | |
504 | ||
505 | #define rq_data_dir(rq) ((rq)->flags & 1) | |
506 | ||
507 | static inline int blk_queue_full(struct request_queue *q, int rw) | |
508 | { | |
509 | if (rw == READ) | |
510 | return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
511 | return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
512 | } | |
513 | ||
514 | static inline void blk_set_queue_full(struct request_queue *q, int rw) | |
515 | { | |
516 | if (rw == READ) | |
517 | set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
518 | else | |
519 | set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
520 | } | |
521 | ||
522 | static inline void blk_clear_queue_full(struct request_queue *q, int rw) | |
523 | { | |
524 | if (rw == READ) | |
525 | clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
526 | else | |
527 | clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
528 | } | |
529 | ||
530 | ||
531 | /* | |
532 | * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may | |
533 | * it already be started by driver. | |
534 | */ | |
535 | #define RQ_NOMERGE_FLAGS \ | |
536 | (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) | |
537 | #define rq_mergeable(rq) \ | |
538 | (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) | |
539 | ||
540 | /* | |
541 | * noop, requests are automagically marked as active/inactive by I/O | |
542 | * scheduler -- see elv_next_request | |
543 | */ | |
544 | #define blk_queue_headactive(q, head_active) | |
545 | ||
546 | /* | |
547 | * q->prep_rq_fn return values | |
548 | */ | |
549 | #define BLKPREP_OK 0 /* serve it */ | |
550 | #define BLKPREP_KILL 1 /* fatal error, kill */ | |
551 | #define BLKPREP_DEFER 2 /* leave on queue */ | |
552 | ||
553 | extern unsigned long blk_max_low_pfn, blk_max_pfn; | |
554 | ||
555 | /* | |
556 | * standard bounce addresses: | |
557 | * | |
558 | * BLK_BOUNCE_HIGH : bounce all highmem pages | |
559 | * BLK_BOUNCE_ANY : don't bounce anything | |
560 | * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary | |
561 | */ | |
562 | #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) | |
563 | #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) | |
564 | #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) | |
565 | ||
566 | #ifdef CONFIG_MMU | |
567 | extern int init_emergency_isa_pool(void); | |
568 | extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); | |
569 | #else | |
570 | static inline int init_emergency_isa_pool(void) | |
571 | { | |
572 | return 0; | |
573 | } | |
574 | static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) | |
575 | { | |
576 | } | |
577 | #endif /* CONFIG_MMU */ | |
578 | ||
579 | #define rq_for_each_bio(_bio, rq) \ | |
580 | if ((rq->bio)) \ | |
581 | for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) | |
582 | ||
583 | struct sec_size { | |
584 | unsigned block_size; | |
585 | unsigned block_size_bits; | |
586 | }; | |
587 | ||
588 | extern int blk_register_queue(struct gendisk *disk); | |
589 | extern void blk_unregister_queue(struct gendisk *disk); | |
590 | extern void register_disk(struct gendisk *dev); | |
591 | extern void generic_make_request(struct bio *bio); | |
592 | extern void blk_put_request(struct request *); | |
6e39b69e | 593 | extern void __blk_put_request(request_queue_t *, struct request *); |
8ffdc655 | 594 | extern void blk_end_sync_rq(struct request *rq, int error); |
1da177e4 | 595 | extern void blk_attempt_remerge(request_queue_t *, struct request *); |
8267e268 | 596 | extern struct request *blk_get_request(request_queue_t *, int, gfp_t); |
867d1191 | 597 | extern void blk_insert_request(request_queue_t *, struct request *, int, void *); |
1da177e4 LT |
598 | extern void blk_requeue_request(request_queue_t *, struct request *); |
599 | extern void blk_plug_device(request_queue_t *); | |
600 | extern int blk_remove_plug(request_queue_t *); | |
601 | extern void blk_recount_segments(request_queue_t *, struct bio *); | |
1da177e4 LT |
602 | extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); |
603 | extern void blk_start_queue(request_queue_t *q); | |
604 | extern void blk_stop_queue(request_queue_t *q); | |
605 | extern void blk_sync_queue(struct request_queue *q); | |
606 | extern void __blk_stop_queue(request_queue_t *q); | |
607 | extern void blk_run_queue(request_queue_t *); | |
608 | extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); | |
dd1cab95 JA |
609 | extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int); |
610 | extern int blk_rq_unmap_user(struct bio *, unsigned int); | |
8267e268 | 611 | extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t); |
f1970baf | 612 | extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int); |
994ca9a1 JB |
613 | extern int blk_execute_rq(request_queue_t *, struct gendisk *, |
614 | struct request *, int); | |
6e39b69e | 615 | extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *, |
15fc858a | 616 | struct request *, int, rq_end_io_fn *); |
6e39b69e | 617 | |
1da177e4 LT |
618 | static inline request_queue_t *bdev_get_queue(struct block_device *bdev) |
619 | { | |
620 | return bdev->bd_disk->queue; | |
621 | } | |
622 | ||
623 | static inline void blk_run_backing_dev(struct backing_dev_info *bdi, | |
624 | struct page *page) | |
625 | { | |
626 | if (bdi && bdi->unplug_io_fn) | |
627 | bdi->unplug_io_fn(bdi, page); | |
628 | } | |
629 | ||
630 | static inline void blk_run_address_space(struct address_space *mapping) | |
631 | { | |
632 | if (mapping) | |
633 | blk_run_backing_dev(mapping->backing_dev_info, NULL); | |
634 | } | |
635 | ||
636 | /* | |
637 | * end_request() and friends. Must be called with the request queue spinlock | |
638 | * acquired. All functions called within end_request() _must_be_ atomic. | |
639 | * | |
640 | * Several drivers define their own end_request and call | |
641 | * end_that_request_first() and end_that_request_last() | |
642 | * for parts of the original function. This prevents | |
643 | * code duplication in drivers. | |
644 | */ | |
645 | extern int end_that_request_first(struct request *, int, int); | |
646 | extern int end_that_request_chunk(struct request *, int, int); | |
8ffdc655 | 647 | extern void end_that_request_last(struct request *, int); |
1da177e4 LT |
648 | extern void end_request(struct request *req, int uptodate); |
649 | ||
650 | /* | |
651 | * end_that_request_first/chunk() takes an uptodate argument. we account | |
652 | * any value <= as an io error. 0 means -EIO for compatability reasons, | |
653 | * any other < 0 value is the direct error type. An uptodate value of | |
654 | * 1 indicates successful io completion | |
655 | */ | |
656 | #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) | |
657 | ||
658 | static inline void blkdev_dequeue_request(struct request *req) | |
659 | { | |
8922e16c | 660 | elv_dequeue_request(req->q, req); |
1da177e4 | 661 | } |
1da177e4 | 662 | |
1b47f531 JA |
663 | /* |
664 | * This should be in elevator.h, but that requires pulling in rq and q | |
665 | */ | |
666 | static inline void elv_dispatch_add_tail(struct request_queue *q, | |
667 | struct request *rq) | |
668 | { | |
06b86245 TH |
669 | if (q->last_merge == rq) |
670 | q->last_merge = NULL; | |
15853af9 | 671 | q->nr_sorted--; |
1da177e4 | 672 | |
1b47f531 JA |
673 | q->end_sector = rq_end_sector(rq); |
674 | q->boundary_rq = rq; | |
675 | list_add_tail(&rq->queuelist, &q->queue_head); | |
1da177e4 LT |
676 | } |
677 | ||
678 | /* | |
679 | * Access functions for manipulating queue properties | |
680 | */ | |
1946089a CL |
681 | extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, |
682 | spinlock_t *lock, int node_id); | |
1da177e4 LT |
683 | extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); |
684 | extern void blk_cleanup_queue(request_queue_t *); | |
685 | extern void blk_queue_make_request(request_queue_t *, make_request_fn *); | |
686 | extern void blk_queue_bounce_limit(request_queue_t *, u64); | |
687 | extern void blk_queue_max_sectors(request_queue_t *, unsigned short); | |
688 | extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); | |
689 | extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); | |
690 | extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); | |
691 | extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); | |
692 | extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); | |
693 | extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); | |
694 | extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); | |
695 | extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); | |
696 | extern void blk_queue_dma_alignment(request_queue_t *, int); | |
697 | extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); | |
797e7dbb | 698 | extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *); |
1da177e4 | 699 | extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); |
797e7dbb TH |
700 | extern int blk_do_ordered(request_queue_t *, struct request **); |
701 | extern unsigned blk_ordered_cur_seq(request_queue_t *); | |
702 | extern unsigned blk_ordered_req_seq(struct request *); | |
703 | extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int); | |
1da177e4 LT |
704 | |
705 | extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); | |
706 | extern void blk_dump_rq_flags(struct request *, char *); | |
707 | extern void generic_unplug_device(request_queue_t *); | |
708 | extern void __generic_unplug_device(request_queue_t *); | |
709 | extern long nr_blockdev_pages(void); | |
1da177e4 LT |
710 | |
711 | int blk_get_queue(request_queue_t *); | |
8267e268 AV |
712 | request_queue_t *blk_alloc_queue(gfp_t); |
713 | request_queue_t *blk_alloc_queue_node(gfp_t, int); | |
1da177e4 LT |
714 | #define blk_put_queue(q) blk_cleanup_queue((q)) |
715 | ||
716 | /* | |
717 | * tag stuff | |
718 | */ | |
719 | #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) | |
720 | #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) | |
721 | #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED) | |
722 | extern int blk_queue_start_tag(request_queue_t *, struct request *); | |
723 | extern struct request *blk_queue_find_tag(request_queue_t *, int); | |
724 | extern void blk_queue_end_tag(request_queue_t *, struct request *); | |
725 | extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); | |
726 | extern void blk_queue_free_tags(request_queue_t *); | |
727 | extern int blk_queue_resize_tags(request_queue_t *, int); | |
728 | extern void blk_queue_invalidate_tags(request_queue_t *); | |
729 | extern long blk_congestion_wait(int rw, long timeout); | |
730 | ||
731 | extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); | |
732 | extern int blkdev_issue_flush(struct block_device *, sector_t *); | |
733 | ||
734 | #define MAX_PHYS_SEGMENTS 128 | |
735 | #define MAX_HW_SEGMENTS 128 | |
defd94b7 MC |
736 | #define SAFE_MAX_SECTORS 255 |
737 | #define BLK_DEF_MAX_SECTORS 1024 | |
1da177e4 LT |
738 | |
739 | #define MAX_SEGMENT_SIZE 65536 | |
740 | ||
741 | #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) | |
742 | ||
1da177e4 LT |
743 | static inline int queue_hardsect_size(request_queue_t *q) |
744 | { | |
745 | int retval = 512; | |
746 | ||
747 | if (q && q->hardsect_size) | |
748 | retval = q->hardsect_size; | |
749 | ||
750 | return retval; | |
751 | } | |
752 | ||
753 | static inline int bdev_hardsect_size(struct block_device *bdev) | |
754 | { | |
755 | return queue_hardsect_size(bdev_get_queue(bdev)); | |
756 | } | |
757 | ||
758 | static inline int queue_dma_alignment(request_queue_t *q) | |
759 | { | |
760 | int retval = 511; | |
761 | ||
762 | if (q && q->dma_alignment) | |
763 | retval = q->dma_alignment; | |
764 | ||
765 | return retval; | |
766 | } | |
767 | ||
768 | static inline int bdev_dma_aligment(struct block_device *bdev) | |
769 | { | |
770 | return queue_dma_alignment(bdev_get_queue(bdev)); | |
771 | } | |
772 | ||
773 | #define blk_finished_io(nsects) do { } while (0) | |
774 | #define blk_started_io(nsects) do { } while (0) | |
775 | ||
776 | /* assumes size > 256 */ | |
777 | static inline unsigned int blksize_bits(unsigned int size) | |
778 | { | |
779 | unsigned int bits = 8; | |
780 | do { | |
781 | bits++; | |
782 | size >>= 1; | |
783 | } while (size > 256); | |
784 | return bits; | |
785 | } | |
786 | ||
2befb9e3 | 787 | static inline unsigned int block_size(struct block_device *bdev) |
1da177e4 LT |
788 | { |
789 | return bdev->bd_block_size; | |
790 | } | |
791 | ||
792 | typedef struct {struct page *v;} Sector; | |
793 | ||
794 | unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); | |
795 | ||
796 | static inline void put_dev_sector(Sector p) | |
797 | { | |
798 | page_cache_release(p.v); | |
799 | } | |
800 | ||
801 | struct work_struct; | |
802 | int kblockd_schedule_work(struct work_struct *work); | |
803 | void kblockd_flush(void); | |
804 | ||
805 | #ifdef CONFIG_LBD | |
806 | # include <asm/div64.h> | |
807 | # define sector_div(a, b) do_div(a, b) | |
808 | #else | |
809 | # define sector_div(n, b)( \ | |
810 | { \ | |
811 | int _res; \ | |
812 | _res = (n) % (b); \ | |
813 | (n) /= (b); \ | |
814 | _res; \ | |
815 | } \ | |
816 | ) | |
817 | #endif | |
818 | ||
819 | #define MODULE_ALIAS_BLOCKDEV(major,minor) \ | |
820 | MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) | |
821 | #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ | |
822 | MODULE_ALIAS("block-major-" __stringify(major) "-*") | |
823 | ||
824 | ||
825 | #endif |