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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 */ | |
210 | __REQ_CMD, /* is a regular fs rw request */ | |
211 | __REQ_NOMERGE, /* don't touch this for merging */ | |
212 | __REQ_STARTED, /* drive already may have started this one */ | |
213 | __REQ_DONTPREP, /* don't call prep for this one */ | |
214 | __REQ_QUEUED, /* uses queueing */ | |
cb98fc8b | 215 | __REQ_ELVPRIV, /* elevator private data attached */ |
1da177e4 LT |
216 | /* |
217 | * for ATA/ATAPI devices | |
218 | */ | |
219 | __REQ_PC, /* packet command (special) */ | |
220 | __REQ_BLOCK_PC, /* queued down pc from block layer */ | |
221 | __REQ_SENSE, /* sense retrival */ | |
222 | ||
223 | __REQ_FAILED, /* set if the request failed */ | |
224 | __REQ_QUIET, /* don't worry about errors */ | |
225 | __REQ_SPECIAL, /* driver suplied command */ | |
226 | __REQ_DRIVE_CMD, | |
227 | __REQ_DRIVE_TASK, | |
228 | __REQ_DRIVE_TASKFILE, | |
229 | __REQ_PREEMPT, /* set for "ide_preempt" requests */ | |
230 | __REQ_PM_SUSPEND, /* suspend request */ | |
231 | __REQ_PM_RESUME, /* resume request */ | |
232 | __REQ_PM_SHUTDOWN, /* shutdown request */ | |
233 | __REQ_BAR_PREFLUSH, /* barrier pre-flush done */ | |
234 | __REQ_BAR_POSTFLUSH, /* barrier post-flush */ | |
235 | __REQ_BAR_FLUSH, /* rq is the flush request */ | |
236 | __REQ_NR_BITS, /* stops here */ | |
237 | }; | |
238 | ||
239 | #define REQ_RW (1 << __REQ_RW) | |
240 | #define REQ_FAILFAST (1 << __REQ_FAILFAST) | |
8922e16c | 241 | #define REQ_SORTED (1 << __REQ_SORTED) |
1da177e4 LT |
242 | #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) |
243 | #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) | |
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) | |
263 | #define REQ_BAR_PREFLUSH (1 << __REQ_BAR_PREFLUSH) | |
264 | #define REQ_BAR_POSTFLUSH (1 << __REQ_BAR_POSTFLUSH) | |
265 | #define REQ_BAR_FLUSH (1 << __REQ_BAR_FLUSH) | |
266 | ||
267 | /* | |
268 | * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME | |
269 | * requests. Some step values could eventually be made generic. | |
270 | */ | |
271 | struct request_pm_state | |
272 | { | |
273 | /* PM state machine step value, currently driver specific */ | |
274 | int pm_step; | |
275 | /* requested PM state value (S1, S2, S3, S4, ...) */ | |
276 | u32 pm_state; | |
277 | void* data; /* for driver use */ | |
278 | }; | |
279 | ||
280 | #include <linux/elevator.h> | |
281 | ||
282 | typedef int (merge_request_fn) (request_queue_t *, struct request *, | |
283 | struct bio *); | |
284 | typedef int (merge_requests_fn) (request_queue_t *, struct request *, | |
285 | struct request *); | |
286 | typedef void (request_fn_proc) (request_queue_t *q); | |
287 | typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); | |
288 | typedef int (prep_rq_fn) (request_queue_t *, struct request *); | |
289 | typedef void (unplug_fn) (request_queue_t *); | |
290 | ||
291 | struct bio_vec; | |
292 | typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); | |
293 | typedef void (activity_fn) (void *data, int rw); | |
294 | typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); | |
295 | typedef int (prepare_flush_fn) (request_queue_t *, struct request *); | |
296 | typedef void (end_flush_fn) (request_queue_t *, struct request *); | |
297 | ||
298 | enum blk_queue_state { | |
299 | Queue_down, | |
300 | Queue_up, | |
301 | }; | |
302 | ||
1da177e4 LT |
303 | struct blk_queue_tag { |
304 | struct request **tag_index; /* map of busy tags */ | |
305 | unsigned long *tag_map; /* bit map of free/busy tags */ | |
306 | struct list_head busy_list; /* fifo list of busy tags */ | |
307 | int busy; /* current depth */ | |
308 | int max_depth; /* what we will send to device */ | |
ba025082 | 309 | int real_max_depth; /* what the array can hold */ |
1da177e4 LT |
310 | atomic_t refcnt; /* map can be shared */ |
311 | }; | |
312 | ||
313 | struct request_queue | |
314 | { | |
315 | /* | |
316 | * Together with queue_head for cacheline sharing | |
317 | */ | |
318 | struct list_head queue_head; | |
319 | struct request *last_merge; | |
320 | elevator_t *elevator; | |
321 | ||
322 | /* | |
323 | * the queue request freelist, one for reads and one for writes | |
324 | */ | |
325 | struct request_list rq; | |
326 | ||
327 | request_fn_proc *request_fn; | |
328 | merge_request_fn *back_merge_fn; | |
329 | merge_request_fn *front_merge_fn; | |
330 | merge_requests_fn *merge_requests_fn; | |
331 | make_request_fn *make_request_fn; | |
332 | prep_rq_fn *prep_rq_fn; | |
333 | unplug_fn *unplug_fn; | |
334 | merge_bvec_fn *merge_bvec_fn; | |
335 | activity_fn *activity_fn; | |
336 | issue_flush_fn *issue_flush_fn; | |
337 | prepare_flush_fn *prepare_flush_fn; | |
338 | end_flush_fn *end_flush_fn; | |
339 | ||
8922e16c TH |
340 | /* |
341 | * Dispatch queue sorting | |
342 | */ | |
1b47f531 | 343 | sector_t end_sector; |
8922e16c | 344 | struct request *boundary_rq; |
8922e16c | 345 | |
1da177e4 LT |
346 | /* |
347 | * Auto-unplugging state | |
348 | */ | |
349 | struct timer_list unplug_timer; | |
350 | int unplug_thresh; /* After this many requests */ | |
351 | unsigned long unplug_delay; /* After this many jiffies */ | |
352 | struct work_struct unplug_work; | |
353 | ||
354 | struct backing_dev_info backing_dev_info; | |
355 | ||
356 | /* | |
357 | * The queue owner gets to use this for whatever they like. | |
358 | * ll_rw_blk doesn't touch it. | |
359 | */ | |
360 | void *queuedata; | |
361 | ||
362 | void *activity_data; | |
363 | ||
364 | /* | |
365 | * queue needs bounce pages for pages above this limit | |
366 | */ | |
367 | unsigned long bounce_pfn; | |
8267e268 | 368 | gfp_t bounce_gfp; |
1da177e4 LT |
369 | |
370 | /* | |
371 | * various queue flags, see QUEUE_* below | |
372 | */ | |
373 | unsigned long queue_flags; | |
374 | ||
375 | /* | |
152587de JA |
376 | * protects queue structures from reentrancy. ->__queue_lock should |
377 | * _never_ be used directly, it is queue private. always use | |
378 | * ->queue_lock. | |
1da177e4 | 379 | */ |
152587de | 380 | spinlock_t __queue_lock; |
1da177e4 LT |
381 | spinlock_t *queue_lock; |
382 | ||
383 | /* | |
384 | * queue kobject | |
385 | */ | |
386 | struct kobject kobj; | |
387 | ||
388 | /* | |
389 | * queue settings | |
390 | */ | |
391 | unsigned long nr_requests; /* Max # of requests */ | |
392 | unsigned int nr_congestion_on; | |
393 | unsigned int nr_congestion_off; | |
394 | unsigned int nr_batching; | |
395 | ||
396 | unsigned short max_sectors; | |
397 | unsigned short max_hw_sectors; | |
398 | unsigned short max_phys_segments; | |
399 | unsigned short max_hw_segments; | |
400 | unsigned short hardsect_size; | |
401 | unsigned int max_segment_size; | |
402 | ||
403 | unsigned long seg_boundary_mask; | |
404 | unsigned int dma_alignment; | |
405 | ||
406 | struct blk_queue_tag *queue_tags; | |
407 | ||
408 | atomic_t refcnt; | |
409 | ||
15853af9 | 410 | unsigned int nr_sorted; |
1da177e4 LT |
411 | unsigned int in_flight; |
412 | ||
413 | /* | |
414 | * sg stuff | |
415 | */ | |
416 | unsigned int sg_timeout; | |
417 | unsigned int sg_reserved_size; | |
1946089a | 418 | int node; |
1da177e4 | 419 | |
1da177e4 LT |
420 | /* |
421 | * reserved for flush operations | |
422 | */ | |
423 | struct request *flush_rq; | |
424 | unsigned char ordered; | |
425 | }; | |
426 | ||
427 | enum { | |
428 | QUEUE_ORDERED_NONE, | |
429 | QUEUE_ORDERED_TAG, | |
430 | QUEUE_ORDERED_FLUSH, | |
431 | }; | |
432 | ||
433 | #define RQ_INACTIVE (-1) | |
434 | #define RQ_ACTIVE 1 | |
435 | #define RQ_SCSI_BUSY 0xffff | |
436 | #define RQ_SCSI_DONE 0xfffe | |
437 | #define RQ_SCSI_DISCONNECTING 0xffe0 | |
438 | ||
439 | #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ | |
440 | #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ | |
441 | #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ | |
442 | #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */ | |
443 | #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */ | |
444 | #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ | |
445 | #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ | |
446 | #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ | |
64521d1a | 447 | #define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */ |
1da177e4 LT |
448 | #define QUEUE_FLAG_FLUSH 9 /* doing barrier flush sequence */ |
449 | ||
450 | #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) | |
451 | #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) | |
452 | #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) | |
453 | #define blk_queue_flushing(q) test_bit(QUEUE_FLAG_FLUSH, &(q)->queue_flags) | |
454 | ||
455 | #define blk_fs_request(rq) ((rq)->flags & REQ_CMD) | |
456 | #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC) | |
457 | #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST) | |
458 | #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED) | |
459 | ||
460 | #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) | |
461 | ||
462 | #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND) | |
463 | #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME) | |
464 | #define blk_pm_request(rq) \ | |
465 | ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME)) | |
466 | ||
8922e16c | 467 | #define blk_sorted_rq(rq) ((rq)->flags & REQ_SORTED) |
1da177e4 LT |
468 | #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER) |
469 | #define blk_barrier_preflush(rq) ((rq)->flags & REQ_BAR_PREFLUSH) | |
470 | #define blk_barrier_postflush(rq) ((rq)->flags & REQ_BAR_POSTFLUSH) | |
471 | ||
472 | #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) | |
473 | ||
474 | #define rq_data_dir(rq) ((rq)->flags & 1) | |
475 | ||
476 | static inline int blk_queue_full(struct request_queue *q, int rw) | |
477 | { | |
478 | if (rw == READ) | |
479 | return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
480 | return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
481 | } | |
482 | ||
483 | static inline void blk_set_queue_full(struct request_queue *q, int rw) | |
484 | { | |
485 | if (rw == READ) | |
486 | set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
487 | else | |
488 | set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
489 | } | |
490 | ||
491 | static inline void blk_clear_queue_full(struct request_queue *q, int rw) | |
492 | { | |
493 | if (rw == READ) | |
494 | clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); | |
495 | else | |
496 | clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); | |
497 | } | |
498 | ||
499 | ||
500 | /* | |
501 | * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may | |
502 | * it already be started by driver. | |
503 | */ | |
504 | #define RQ_NOMERGE_FLAGS \ | |
505 | (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) | |
506 | #define rq_mergeable(rq) \ | |
507 | (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) | |
508 | ||
509 | /* | |
510 | * noop, requests are automagically marked as active/inactive by I/O | |
511 | * scheduler -- see elv_next_request | |
512 | */ | |
513 | #define blk_queue_headactive(q, head_active) | |
514 | ||
515 | /* | |
516 | * q->prep_rq_fn return values | |
517 | */ | |
518 | #define BLKPREP_OK 0 /* serve it */ | |
519 | #define BLKPREP_KILL 1 /* fatal error, kill */ | |
520 | #define BLKPREP_DEFER 2 /* leave on queue */ | |
521 | ||
522 | extern unsigned long blk_max_low_pfn, blk_max_pfn; | |
523 | ||
524 | /* | |
525 | * standard bounce addresses: | |
526 | * | |
527 | * BLK_BOUNCE_HIGH : bounce all highmem pages | |
528 | * BLK_BOUNCE_ANY : don't bounce anything | |
529 | * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary | |
530 | */ | |
531 | #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) | |
532 | #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) | |
533 | #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) | |
534 | ||
535 | #ifdef CONFIG_MMU | |
536 | extern int init_emergency_isa_pool(void); | |
537 | extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); | |
538 | #else | |
539 | static inline int init_emergency_isa_pool(void) | |
540 | { | |
541 | return 0; | |
542 | } | |
543 | static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) | |
544 | { | |
545 | } | |
546 | #endif /* CONFIG_MMU */ | |
547 | ||
548 | #define rq_for_each_bio(_bio, rq) \ | |
549 | if ((rq->bio)) \ | |
550 | for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) | |
551 | ||
552 | struct sec_size { | |
553 | unsigned block_size; | |
554 | unsigned block_size_bits; | |
555 | }; | |
556 | ||
557 | extern int blk_register_queue(struct gendisk *disk); | |
558 | extern void blk_unregister_queue(struct gendisk *disk); | |
559 | extern void register_disk(struct gendisk *dev); | |
560 | extern void generic_make_request(struct bio *bio); | |
561 | extern void blk_put_request(struct request *); | |
6e39b69e | 562 | extern void __blk_put_request(request_queue_t *, struct request *); |
8ffdc655 | 563 | extern void blk_end_sync_rq(struct request *rq, int error); |
1da177e4 | 564 | extern void blk_attempt_remerge(request_queue_t *, struct request *); |
8267e268 | 565 | extern struct request *blk_get_request(request_queue_t *, int, gfp_t); |
867d1191 | 566 | extern void blk_insert_request(request_queue_t *, struct request *, int, void *); |
1da177e4 LT |
567 | extern void blk_requeue_request(request_queue_t *, struct request *); |
568 | extern void blk_plug_device(request_queue_t *); | |
569 | extern int blk_remove_plug(request_queue_t *); | |
570 | extern void blk_recount_segments(request_queue_t *, struct bio *); | |
1da177e4 LT |
571 | extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); |
572 | extern void blk_start_queue(request_queue_t *q); | |
573 | extern void blk_stop_queue(request_queue_t *q); | |
574 | extern void blk_sync_queue(struct request_queue *q); | |
575 | extern void __blk_stop_queue(request_queue_t *q); | |
576 | extern void blk_run_queue(request_queue_t *); | |
577 | extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); | |
dd1cab95 JA |
578 | extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int); |
579 | extern int blk_rq_unmap_user(struct bio *, unsigned int); | |
8267e268 | 580 | extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t); |
f1970baf | 581 | extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int); |
994ca9a1 JB |
582 | extern int blk_execute_rq(request_queue_t *, struct gendisk *, |
583 | struct request *, int); | |
6e39b69e MC |
584 | extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *, |
585 | struct request *, int, | |
586 | void (*done)(struct request *)); | |
587 | ||
1da177e4 LT |
588 | static inline request_queue_t *bdev_get_queue(struct block_device *bdev) |
589 | { | |
590 | return bdev->bd_disk->queue; | |
591 | } | |
592 | ||
593 | static inline void blk_run_backing_dev(struct backing_dev_info *bdi, | |
594 | struct page *page) | |
595 | { | |
596 | if (bdi && bdi->unplug_io_fn) | |
597 | bdi->unplug_io_fn(bdi, page); | |
598 | } | |
599 | ||
600 | static inline void blk_run_address_space(struct address_space *mapping) | |
601 | { | |
602 | if (mapping) | |
603 | blk_run_backing_dev(mapping->backing_dev_info, NULL); | |
604 | } | |
605 | ||
606 | /* | |
607 | * end_request() and friends. Must be called with the request queue spinlock | |
608 | * acquired. All functions called within end_request() _must_be_ atomic. | |
609 | * | |
610 | * Several drivers define their own end_request and call | |
611 | * end_that_request_first() and end_that_request_last() | |
612 | * for parts of the original function. This prevents | |
613 | * code duplication in drivers. | |
614 | */ | |
615 | extern int end_that_request_first(struct request *, int, int); | |
616 | extern int end_that_request_chunk(struct request *, int, int); | |
8ffdc655 | 617 | extern void end_that_request_last(struct request *, int); |
1da177e4 LT |
618 | extern void end_request(struct request *req, int uptodate); |
619 | ||
620 | /* | |
621 | * end_that_request_first/chunk() takes an uptodate argument. we account | |
622 | * any value <= as an io error. 0 means -EIO for compatability reasons, | |
623 | * any other < 0 value is the direct error type. An uptodate value of | |
624 | * 1 indicates successful io completion | |
625 | */ | |
626 | #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) | |
627 | ||
628 | static inline void blkdev_dequeue_request(struct request *req) | |
629 | { | |
8922e16c | 630 | elv_dequeue_request(req->q, req); |
1da177e4 | 631 | } |
1da177e4 | 632 | |
1b47f531 JA |
633 | /* |
634 | * This should be in elevator.h, but that requires pulling in rq and q | |
635 | */ | |
636 | static inline void elv_dispatch_add_tail(struct request_queue *q, | |
637 | struct request *rq) | |
638 | { | |
06b86245 TH |
639 | if (q->last_merge == rq) |
640 | q->last_merge = NULL; | |
15853af9 | 641 | q->nr_sorted--; |
1da177e4 | 642 | |
1b47f531 JA |
643 | q->end_sector = rq_end_sector(rq); |
644 | q->boundary_rq = rq; | |
645 | list_add_tail(&rq->queuelist, &q->queue_head); | |
1da177e4 LT |
646 | } |
647 | ||
648 | /* | |
649 | * Access functions for manipulating queue properties | |
650 | */ | |
1946089a CL |
651 | extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, |
652 | spinlock_t *lock, int node_id); | |
1da177e4 LT |
653 | extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); |
654 | extern void blk_cleanup_queue(request_queue_t *); | |
655 | extern void blk_queue_make_request(request_queue_t *, make_request_fn *); | |
656 | extern void blk_queue_bounce_limit(request_queue_t *, u64); | |
657 | extern void blk_queue_max_sectors(request_queue_t *, unsigned short); | |
658 | extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); | |
659 | extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); | |
660 | extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); | |
661 | extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); | |
662 | extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); | |
663 | extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); | |
664 | extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); | |
665 | extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); | |
666 | extern void blk_queue_dma_alignment(request_queue_t *, int); | |
667 | extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); | |
668 | extern void blk_queue_ordered(request_queue_t *, int); | |
669 | extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); | |
1da177e4 LT |
670 | extern struct request *blk_start_pre_flush(request_queue_t *,struct request *); |
671 | extern int blk_complete_barrier_rq(request_queue_t *, struct request *, int); | |
672 | extern int blk_complete_barrier_rq_locked(request_queue_t *, struct request *, int); | |
673 | ||
674 | extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); | |
675 | extern void blk_dump_rq_flags(struct request *, char *); | |
676 | extern void generic_unplug_device(request_queue_t *); | |
677 | extern void __generic_unplug_device(request_queue_t *); | |
678 | extern long nr_blockdev_pages(void); | |
1da177e4 LT |
679 | |
680 | int blk_get_queue(request_queue_t *); | |
8267e268 AV |
681 | request_queue_t *blk_alloc_queue(gfp_t); |
682 | request_queue_t *blk_alloc_queue_node(gfp_t, int); | |
1da177e4 LT |
683 | #define blk_put_queue(q) blk_cleanup_queue((q)) |
684 | ||
685 | /* | |
686 | * tag stuff | |
687 | */ | |
688 | #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) | |
689 | #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) | |
690 | #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED) | |
691 | extern int blk_queue_start_tag(request_queue_t *, struct request *); | |
692 | extern struct request *blk_queue_find_tag(request_queue_t *, int); | |
693 | extern void blk_queue_end_tag(request_queue_t *, struct request *); | |
694 | extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); | |
695 | extern void blk_queue_free_tags(request_queue_t *); | |
696 | extern int blk_queue_resize_tags(request_queue_t *, int); | |
697 | extern void blk_queue_invalidate_tags(request_queue_t *); | |
698 | extern long blk_congestion_wait(int rw, long timeout); | |
699 | ||
700 | extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); | |
701 | extern int blkdev_issue_flush(struct block_device *, sector_t *); | |
702 | ||
703 | #define MAX_PHYS_SEGMENTS 128 | |
704 | #define MAX_HW_SEGMENTS 128 | |
defd94b7 MC |
705 | #define SAFE_MAX_SECTORS 255 |
706 | #define BLK_DEF_MAX_SECTORS 1024 | |
1da177e4 LT |
707 | |
708 | #define MAX_SEGMENT_SIZE 65536 | |
709 | ||
710 | #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) | |
711 | ||
1da177e4 LT |
712 | static inline int queue_hardsect_size(request_queue_t *q) |
713 | { | |
714 | int retval = 512; | |
715 | ||
716 | if (q && q->hardsect_size) | |
717 | retval = q->hardsect_size; | |
718 | ||
719 | return retval; | |
720 | } | |
721 | ||
722 | static inline int bdev_hardsect_size(struct block_device *bdev) | |
723 | { | |
724 | return queue_hardsect_size(bdev_get_queue(bdev)); | |
725 | } | |
726 | ||
727 | static inline int queue_dma_alignment(request_queue_t *q) | |
728 | { | |
729 | int retval = 511; | |
730 | ||
731 | if (q && q->dma_alignment) | |
732 | retval = q->dma_alignment; | |
733 | ||
734 | return retval; | |
735 | } | |
736 | ||
737 | static inline int bdev_dma_aligment(struct block_device *bdev) | |
738 | { | |
739 | return queue_dma_alignment(bdev_get_queue(bdev)); | |
740 | } | |
741 | ||
742 | #define blk_finished_io(nsects) do { } while (0) | |
743 | #define blk_started_io(nsects) do { } while (0) | |
744 | ||
745 | /* assumes size > 256 */ | |
746 | static inline unsigned int blksize_bits(unsigned int size) | |
747 | { | |
748 | unsigned int bits = 8; | |
749 | do { | |
750 | bits++; | |
751 | size >>= 1; | |
752 | } while (size > 256); | |
753 | return bits; | |
754 | } | |
755 | ||
2befb9e3 | 756 | static inline unsigned int block_size(struct block_device *bdev) |
1da177e4 LT |
757 | { |
758 | return bdev->bd_block_size; | |
759 | } | |
760 | ||
761 | typedef struct {struct page *v;} Sector; | |
762 | ||
763 | unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); | |
764 | ||
765 | static inline void put_dev_sector(Sector p) | |
766 | { | |
767 | page_cache_release(p.v); | |
768 | } | |
769 | ||
770 | struct work_struct; | |
771 | int kblockd_schedule_work(struct work_struct *work); | |
772 | void kblockd_flush(void); | |
773 | ||
774 | #ifdef CONFIG_LBD | |
775 | # include <asm/div64.h> | |
776 | # define sector_div(a, b) do_div(a, b) | |
777 | #else | |
778 | # define sector_div(n, b)( \ | |
779 | { \ | |
780 | int _res; \ | |
781 | _res = (n) % (b); \ | |
782 | (n) /= (b); \ | |
783 | _res; \ | |
784 | } \ | |
785 | ) | |
786 | #endif | |
787 | ||
788 | #define MODULE_ALIAS_BLOCKDEV(major,minor) \ | |
789 | MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) | |
790 | #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ | |
791 | MODULE_ALIAS("block-major-" __stringify(major) "-*") | |
792 | ||
793 | ||
794 | #endif |