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 /* 58 * circular list of cfq_io_contexts belonging to a process io context 59 */ 60 struct list_head list; 61 struct cfq_queue *cfqq; 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 *); 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; 83 struct task_struct *task; 84 85 int (*set_ioprio)(struct io_context *, unsigned int); 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 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); 99 struct io_context *current_io_context(int gfp_flags); 100 struct io_context *get_io_context(int gfp_flags); 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; 105 typedef void (rq_end_io_fn)(struct request *); 106 107 struct request_list { 108 int count[2]; 109 int starved[2]; 110 mempool_t *rq_pool; 111 wait_queue_head_t wait[2]; 112 wait_queue_head_t drain; 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; 144 145 unsigned short ioprio; 146 147 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; 187 188 /* 189 * For Power Management requests 190 */ 191 struct request_pm_state *pm; 192 193 /* 194 * completion callback. end_io_data should be folded in with waiting 195 */ 196 rq_end_io_fn *end_io; 197 void *end_io_data; 198 }; 199 200 /* 201 * first three bits match BIO_RW* bits, important 202 */ 203 enum rq_flag_bits { 204 __REQ_RW, /* not set, read. set, write */ 205 __REQ_FAILFAST, /* no low level driver retries */ 206 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 207 __REQ_HARDBARRIER, /* may not be passed by drive either */ 208 __REQ_CMD, /* is a regular fs rw request */ 209 __REQ_NOMERGE, /* don't touch this for merging */ 210 __REQ_STARTED, /* drive already may have started this one */ 211 __REQ_DONTPREP, /* don't call prep for this one */ 212 __REQ_QUEUED, /* uses queueing */ 213 /* 214 * for ATA/ATAPI devices 215 */ 216 __REQ_PC, /* packet command (special) */ 217 __REQ_BLOCK_PC, /* queued down pc from block layer */ 218 __REQ_SENSE, /* sense retrival */ 219 220 __REQ_FAILED, /* set if the request failed */ 221 __REQ_QUIET, /* don't worry about errors */ 222 __REQ_SPECIAL, /* driver suplied command */ 223 __REQ_DRIVE_CMD, 224 __REQ_DRIVE_TASK, 225 __REQ_DRIVE_TASKFILE, 226 __REQ_PREEMPT, /* set for "ide_preempt" requests */ 227 __REQ_PM_SUSPEND, /* suspend request */ 228 __REQ_PM_RESUME, /* resume request */ 229 __REQ_PM_SHUTDOWN, /* shutdown request */ 230 __REQ_BAR_PREFLUSH, /* barrier pre-flush done */ 231 __REQ_BAR_POSTFLUSH, /* barrier post-flush */ 232 __REQ_BAR_FLUSH, /* rq is the flush request */ 233 __REQ_NR_BITS, /* stops here */ 234 }; 235 236 #define REQ_RW (1 << __REQ_RW) 237 #define REQ_FAILFAST (1 << __REQ_FAILFAST) 238 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) 239 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) 240 #define REQ_CMD (1 << __REQ_CMD) 241 #define REQ_NOMERGE (1 << __REQ_NOMERGE) 242 #define REQ_STARTED (1 << __REQ_STARTED) 243 #define REQ_DONTPREP (1 << __REQ_DONTPREP) 244 #define REQ_QUEUED (1 << __REQ_QUEUED) 245 #define REQ_PC (1 << __REQ_PC) 246 #define REQ_BLOCK_PC (1 << __REQ_BLOCK_PC) 247 #define REQ_SENSE (1 << __REQ_SENSE) 248 #define REQ_FAILED (1 << __REQ_FAILED) 249 #define REQ_QUIET (1 << __REQ_QUIET) 250 #define REQ_SPECIAL (1 << __REQ_SPECIAL) 251 #define REQ_DRIVE_CMD (1 << __REQ_DRIVE_CMD) 252 #define REQ_DRIVE_TASK (1 << __REQ_DRIVE_TASK) 253 #define REQ_DRIVE_TASKFILE (1 << __REQ_DRIVE_TASKFILE) 254 #define REQ_PREEMPT (1 << __REQ_PREEMPT) 255 #define REQ_PM_SUSPEND (1 << __REQ_PM_SUSPEND) 256 #define REQ_PM_RESUME (1 << __REQ_PM_RESUME) 257 #define REQ_PM_SHUTDOWN (1 << __REQ_PM_SHUTDOWN) 258 #define REQ_BAR_PREFLUSH (1 << __REQ_BAR_PREFLUSH) 259 #define REQ_BAR_POSTFLUSH (1 << __REQ_BAR_POSTFLUSH) 260 #define REQ_BAR_FLUSH (1 << __REQ_BAR_FLUSH) 261 262 /* 263 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME 264 * requests. Some step values could eventually be made generic. 265 */ 266 struct request_pm_state 267 { 268 /* PM state machine step value, currently driver specific */ 269 int pm_step; 270 /* requested PM state value (S1, S2, S3, S4, ...) */ 271 u32 pm_state; 272 void* data; /* for driver use */ 273 }; 274 275 #include <linux/elevator.h> 276 277 typedef int (merge_request_fn) (request_queue_t *, struct request *, 278 struct bio *); 279 typedef int (merge_requests_fn) (request_queue_t *, struct request *, 280 struct request *); 281 typedef void (request_fn_proc) (request_queue_t *q); 282 typedef int (make_request_fn) (request_queue_t *q, struct bio *bio); 283 typedef int (prep_rq_fn) (request_queue_t *, struct request *); 284 typedef void (unplug_fn) (request_queue_t *); 285 286 struct bio_vec; 287 typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *); 288 typedef void (activity_fn) (void *data, int rw); 289 typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *); 290 typedef int (prepare_flush_fn) (request_queue_t *, struct request *); 291 typedef void (end_flush_fn) (request_queue_t *, struct request *); 292 293 enum blk_queue_state { 294 Queue_down, 295 Queue_up, 296 }; 297 298 struct blk_queue_tag { 299 struct request **tag_index; /* map of busy tags */ 300 unsigned long *tag_map; /* bit map of free/busy tags */ 301 struct list_head busy_list; /* fifo list of busy tags */ 302 int busy; /* current depth */ 303 int max_depth; /* what we will send to device */ 304 int real_max_depth; /* what the array can hold */ 305 atomic_t refcnt; /* map can be shared */ 306 }; 307 308 struct request_queue 309 { 310 /* 311 * Together with queue_head for cacheline sharing 312 */ 313 struct list_head queue_head; 314 struct request *last_merge; 315 elevator_t *elevator; 316 317 /* 318 * the queue request freelist, one for reads and one for writes 319 */ 320 struct request_list rq; 321 322 request_fn_proc *request_fn; 323 merge_request_fn *back_merge_fn; 324 merge_request_fn *front_merge_fn; 325 merge_requests_fn *merge_requests_fn; 326 make_request_fn *make_request_fn; 327 prep_rq_fn *prep_rq_fn; 328 unplug_fn *unplug_fn; 329 merge_bvec_fn *merge_bvec_fn; 330 activity_fn *activity_fn; 331 issue_flush_fn *issue_flush_fn; 332 prepare_flush_fn *prepare_flush_fn; 333 end_flush_fn *end_flush_fn; 334 335 /* 336 * Auto-unplugging state 337 */ 338 struct timer_list unplug_timer; 339 int unplug_thresh; /* After this many requests */ 340 unsigned long unplug_delay; /* After this many jiffies */ 341 struct work_struct unplug_work; 342 343 struct backing_dev_info backing_dev_info; 344 345 /* 346 * The queue owner gets to use this for whatever they like. 347 * ll_rw_blk doesn't touch it. 348 */ 349 void *queuedata; 350 351 void *activity_data; 352 353 /* 354 * queue needs bounce pages for pages above this limit 355 */ 356 unsigned long bounce_pfn; 357 unsigned int bounce_gfp; 358 359 /* 360 * various queue flags, see QUEUE_* below 361 */ 362 unsigned long queue_flags; 363 364 /* 365 * protects queue structures from reentrancy. ->__queue_lock should 366 * _never_ be used directly, it is queue private. always use 367 * ->queue_lock. 368 */ 369 spinlock_t __queue_lock; 370 spinlock_t *queue_lock; 371 372 /* 373 * queue kobject 374 */ 375 struct kobject kobj; 376 377 /* 378 * queue settings 379 */ 380 unsigned long nr_requests; /* Max # of requests */ 381 unsigned int nr_congestion_on; 382 unsigned int nr_congestion_off; 383 unsigned int nr_batching; 384 385 unsigned short max_sectors; 386 unsigned short max_hw_sectors; 387 unsigned short max_phys_segments; 388 unsigned short max_hw_segments; 389 unsigned short hardsect_size; 390 unsigned int max_segment_size; 391 392 unsigned long seg_boundary_mask; 393 unsigned int dma_alignment; 394 395 struct blk_queue_tag *queue_tags; 396 397 atomic_t refcnt; 398 399 unsigned int in_flight; 400 401 /* 402 * sg stuff 403 */ 404 unsigned int sg_timeout; 405 unsigned int sg_reserved_size; 406 int node; 407 408 struct list_head drain_list; 409 410 /* 411 * reserved for flush operations 412 */ 413 struct request *flush_rq; 414 unsigned char ordered; 415 }; 416 417 enum { 418 QUEUE_ORDERED_NONE, 419 QUEUE_ORDERED_TAG, 420 QUEUE_ORDERED_FLUSH, 421 }; 422 423 #define RQ_INACTIVE (-1) 424 #define RQ_ACTIVE 1 425 #define RQ_SCSI_BUSY 0xffff 426 #define RQ_SCSI_DONE 0xfffe 427 #define RQ_SCSI_DISCONNECTING 0xffe0 428 429 #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ 430 #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ 431 #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ 432 #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */ 433 #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */ 434 #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ 435 #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ 436 #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ 437 #define QUEUE_FLAG_DRAIN 8 /* draining queue for sched switch */ 438 #define QUEUE_FLAG_FLUSH 9 /* doing barrier flush sequence */ 439 440 #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) 441 #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) 442 #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) 443 #define blk_queue_flushing(q) test_bit(QUEUE_FLAG_FLUSH, &(q)->queue_flags) 444 445 #define blk_fs_request(rq) ((rq)->flags & REQ_CMD) 446 #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC) 447 #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST) 448 #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED) 449 450 #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) 451 452 #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND) 453 #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME) 454 #define blk_pm_request(rq) \ 455 ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME)) 456 457 #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER) 458 #define blk_barrier_preflush(rq) ((rq)->flags & REQ_BAR_PREFLUSH) 459 #define blk_barrier_postflush(rq) ((rq)->flags & REQ_BAR_POSTFLUSH) 460 461 #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) 462 463 #define rq_data_dir(rq) ((rq)->flags & 1) 464 465 static inline int blk_queue_full(struct request_queue *q, int rw) 466 { 467 if (rw == READ) 468 return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 469 return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 470 } 471 472 static inline void blk_set_queue_full(struct request_queue *q, int rw) 473 { 474 if (rw == READ) 475 set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 476 else 477 set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 478 } 479 480 static inline void blk_clear_queue_full(struct request_queue *q, int rw) 481 { 482 if (rw == READ) 483 clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); 484 else 485 clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); 486 } 487 488 489 /* 490 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may 491 * it already be started by driver. 492 */ 493 #define RQ_NOMERGE_FLAGS \ 494 (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) 495 #define rq_mergeable(rq) \ 496 (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) 497 498 /* 499 * noop, requests are automagically marked as active/inactive by I/O 500 * scheduler -- see elv_next_request 501 */ 502 #define blk_queue_headactive(q, head_active) 503 504 /* 505 * q->prep_rq_fn return values 506 */ 507 #define BLKPREP_OK 0 /* serve it */ 508 #define BLKPREP_KILL 1 /* fatal error, kill */ 509 #define BLKPREP_DEFER 2 /* leave on queue */ 510 511 extern unsigned long blk_max_low_pfn, blk_max_pfn; 512 513 /* 514 * standard bounce addresses: 515 * 516 * BLK_BOUNCE_HIGH : bounce all highmem pages 517 * BLK_BOUNCE_ANY : don't bounce anything 518 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary 519 */ 520 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) 521 #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) 522 #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) 523 524 #ifdef CONFIG_MMU 525 extern int init_emergency_isa_pool(void); 526 extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); 527 #else 528 static inline int init_emergency_isa_pool(void) 529 { 530 return 0; 531 } 532 static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) 533 { 534 } 535 #endif /* CONFIG_MMU */ 536 537 #define rq_for_each_bio(_bio, rq) \ 538 if ((rq->bio)) \ 539 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) 540 541 struct sec_size { 542 unsigned block_size; 543 unsigned block_size_bits; 544 }; 545 546 extern int blk_register_queue(struct gendisk *disk); 547 extern void blk_unregister_queue(struct gendisk *disk); 548 extern void register_disk(struct gendisk *dev); 549 extern void generic_make_request(struct bio *bio); 550 extern void blk_put_request(struct request *); 551 extern void blk_end_sync_rq(struct request *rq); 552 extern void blk_attempt_remerge(request_queue_t *, struct request *); 553 extern struct request *blk_get_request(request_queue_t *, int, int); 554 extern void blk_insert_request(request_queue_t *, struct request *, int, void *); 555 extern void blk_requeue_request(request_queue_t *, struct request *); 556 extern void blk_plug_device(request_queue_t *); 557 extern int blk_remove_plug(request_queue_t *); 558 extern void blk_recount_segments(request_queue_t *, struct bio *); 559 extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); 560 extern void blk_start_queue(request_queue_t *q); 561 extern void blk_stop_queue(request_queue_t *q); 562 extern void blk_sync_queue(struct request_queue *q); 563 extern void __blk_stop_queue(request_queue_t *q); 564 extern void blk_run_queue(request_queue_t *); 565 extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); 566 extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int); 567 extern int blk_rq_unmap_user(struct bio *, unsigned int); 568 extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, unsigned int); 569 extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int); 570 extern int blk_execute_rq(request_queue_t *, struct gendisk *, 571 struct request *, int); 572 static inline request_queue_t *bdev_get_queue(struct block_device *bdev) 573 { 574 return bdev->bd_disk->queue; 575 } 576 577 static inline void blk_run_backing_dev(struct backing_dev_info *bdi, 578 struct page *page) 579 { 580 if (bdi && bdi->unplug_io_fn) 581 bdi->unplug_io_fn(bdi, page); 582 } 583 584 static inline void blk_run_address_space(struct address_space *mapping) 585 { 586 if (mapping) 587 blk_run_backing_dev(mapping->backing_dev_info, NULL); 588 } 589 590 /* 591 * end_request() and friends. Must be called with the request queue spinlock 592 * acquired. All functions called within end_request() _must_be_ atomic. 593 * 594 * Several drivers define their own end_request and call 595 * end_that_request_first() and end_that_request_last() 596 * for parts of the original function. This prevents 597 * code duplication in drivers. 598 */ 599 extern int end_that_request_first(struct request *, int, int); 600 extern int end_that_request_chunk(struct request *, int, int); 601 extern void end_that_request_last(struct request *); 602 extern void end_request(struct request *req, int uptodate); 603 604 /* 605 * end_that_request_first/chunk() takes an uptodate argument. we account 606 * any value <= as an io error. 0 means -EIO for compatability reasons, 607 * any other < 0 value is the direct error type. An uptodate value of 608 * 1 indicates successful io completion 609 */ 610 #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) 611 612 static inline void blkdev_dequeue_request(struct request *req) 613 { 614 BUG_ON(list_empty(&req->queuelist)); 615 616 list_del_init(&req->queuelist); 617 618 if (req->rl) 619 elv_remove_request(req->q, req); 620 } 621 622 /* 623 * Access functions for manipulating queue properties 624 */ 625 extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, 626 spinlock_t *lock, int node_id); 627 extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); 628 extern void blk_cleanup_queue(request_queue_t *); 629 extern void blk_queue_make_request(request_queue_t *, make_request_fn *); 630 extern void blk_queue_bounce_limit(request_queue_t *, u64); 631 extern void blk_queue_max_sectors(request_queue_t *, unsigned short); 632 extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); 633 extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); 634 extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); 635 extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); 636 extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); 637 extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); 638 extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); 639 extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); 640 extern void blk_queue_dma_alignment(request_queue_t *, int); 641 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); 642 extern void blk_queue_ordered(request_queue_t *, int); 643 extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); 644 extern struct request *blk_start_pre_flush(request_queue_t *,struct request *); 645 extern int blk_complete_barrier_rq(request_queue_t *, struct request *, int); 646 extern int blk_complete_barrier_rq_locked(request_queue_t *, struct request *, int); 647 648 extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); 649 extern void blk_dump_rq_flags(struct request *, char *); 650 extern void generic_unplug_device(request_queue_t *); 651 extern void __generic_unplug_device(request_queue_t *); 652 extern long nr_blockdev_pages(void); 653 extern void blk_wait_queue_drained(request_queue_t *, int); 654 extern void blk_finish_queue_drain(request_queue_t *); 655 656 int blk_get_queue(request_queue_t *); 657 request_queue_t *blk_alloc_queue(int gfp_mask); 658 request_queue_t *blk_alloc_queue_node(int,int); 659 #define blk_put_queue(q) blk_cleanup_queue((q)) 660 661 /* 662 * tag stuff 663 */ 664 #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) 665 #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) 666 #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED) 667 extern int blk_queue_start_tag(request_queue_t *, struct request *); 668 extern struct request *blk_queue_find_tag(request_queue_t *, int); 669 extern void blk_queue_end_tag(request_queue_t *, struct request *); 670 extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); 671 extern void blk_queue_free_tags(request_queue_t *); 672 extern int blk_queue_resize_tags(request_queue_t *, int); 673 extern void blk_queue_invalidate_tags(request_queue_t *); 674 extern long blk_congestion_wait(int rw, long timeout); 675 676 extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); 677 extern int blkdev_issue_flush(struct block_device *, sector_t *); 678 679 #define MAX_PHYS_SEGMENTS 128 680 #define MAX_HW_SEGMENTS 128 681 #define MAX_SECTORS 255 682 683 #define MAX_SEGMENT_SIZE 65536 684 685 #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) 686 687 static inline int queue_hardsect_size(request_queue_t *q) 688 { 689 int retval = 512; 690 691 if (q && q->hardsect_size) 692 retval = q->hardsect_size; 693 694 return retval; 695 } 696 697 static inline int bdev_hardsect_size(struct block_device *bdev) 698 { 699 return queue_hardsect_size(bdev_get_queue(bdev)); 700 } 701 702 static inline int queue_dma_alignment(request_queue_t *q) 703 { 704 int retval = 511; 705 706 if (q && q->dma_alignment) 707 retval = q->dma_alignment; 708 709 return retval; 710 } 711 712 static inline int bdev_dma_aligment(struct block_device *bdev) 713 { 714 return queue_dma_alignment(bdev_get_queue(bdev)); 715 } 716 717 #define blk_finished_io(nsects) do { } while (0) 718 #define blk_started_io(nsects) do { } while (0) 719 720 /* assumes size > 256 */ 721 static inline unsigned int blksize_bits(unsigned int size) 722 { 723 unsigned int bits = 8; 724 do { 725 bits++; 726 size >>= 1; 727 } while (size > 256); 728 return bits; 729 } 730 731 extern inline unsigned int block_size(struct block_device *bdev) 732 { 733 return bdev->bd_block_size; 734 } 735 736 typedef struct {struct page *v;} Sector; 737 738 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); 739 740 static inline void put_dev_sector(Sector p) 741 { 742 page_cache_release(p.v); 743 } 744 745 struct work_struct; 746 int kblockd_schedule_work(struct work_struct *work); 747 void kblockd_flush(void); 748 749 #ifdef CONFIG_LBD 750 # include <asm/div64.h> 751 # define sector_div(a, b) do_div(a, b) 752 #else 753 # define sector_div(n, b)( \ 754 { \ 755 int _res; \ 756 _res = (n) % (b); \ 757 (n) /= (b); \ 758 _res; \ 759 } \ 760 ) 761 #endif 762 763 #define MODULE_ALIAS_BLOCKDEV(major,minor) \ 764 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) 765 #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ 766 MODULE_ALIAS("block-major-" __stringify(major) "-*") 767 768 769 #endif 770