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