blkdev.h 24.8 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
#ifndef _LINUX_BLKDEV_H
#define _LINUX_BLKDEV_H

#include <linux/config.h>
#include <linux/major.h>
#include <linux/genhd.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/pagemap.h>
#include <linux/backing-dev.h>
#include <linux/wait.h>
#include <linux/mempool.h>
#include <linux/bio.h>
#include <linux/module.h>
#include <linux/stringify.h>

#include <asm/scatterlist.h>

struct request_queue;
typedef struct request_queue request_queue_t;
struct elevator_queue;
typedef struct elevator_queue elevator_t;
struct request_pm_state;

#define BLKDEV_MIN_RQ	4
#define BLKDEV_MAX_RQ	128	/* Default maximum */

/*
 * This is the per-process anticipatory I/O scheduler state.
 */
struct as_io_context {
	spinlock_t lock;

	void (*dtor)(struct as_io_context *aic); /* destructor */
	void (*exit)(struct as_io_context *aic); /* called on task exit */

	unsigned long state;
	atomic_t nr_queued; /* queued reads & sync writes */
	atomic_t nr_dispatched; /* number of requests gone to the drivers */

	/* IO History tracking */
	/* Thinktime */
	unsigned long last_end_request;
	unsigned long ttime_total;
	unsigned long ttime_samples;
	unsigned long ttime_mean;
	/* Layout pattern */
	unsigned int seek_samples;
	sector_t last_request_pos;
	u64 seek_total;
	sector_t seek_mean;
};

struct cfq_queue;
struct cfq_io_context {
	/*
	 * circular list of cfq_io_contexts belonging to a process io context
	 */
	struct list_head list;
61
	struct cfq_queue *cfqq[2];
62 63 64 65 66 67 68 69 70 71
	void *key;

	struct io_context *ioc;

	unsigned long last_end_request;
	unsigned long last_queue;
	unsigned long ttime_total;
	unsigned long ttime_samples;
	unsigned long ttime_mean;

72 73
	struct list_head queue_list;

74 75
	void (*dtor)(struct cfq_io_context *);
	void (*exit)(struct cfq_io_context *);
L
Linus Torvalds 已提交
76 77 78 79 80 81 82 83 84
};

/*
 * This is the per-process I/O subsystem state.  It is refcounted and
 * kmalloc'ed. Currently all fields are modified in process io context
 * (apart from the atomic refcount), so require no locking.
 */
struct io_context {
	atomic_t refcount;
85 86 87
	struct task_struct *task;

	int (*set_ioprio)(struct io_context *, unsigned int);
L
Linus Torvalds 已提交
88 89 90 91 92 93 94 95 96 97 98 99 100

	/*
	 * For request batching
	 */
	unsigned long last_waited; /* Time last woken after wait for request */
	int nr_batch_requests;     /* Number of requests left in the batch */

	struct as_io_context *aic;
	struct cfq_io_context *cic;
};

void put_io_context(struct io_context *ioc);
void exit_io_context(void);
A
Al Viro 已提交
101 102
struct io_context *current_io_context(gfp_t gfp_flags);
struct io_context *get_io_context(gfp_t gfp_flags);
L
Linus Torvalds 已提交
103 104 105 106
void copy_io_context(struct io_context **pdst, struct io_context **psrc);
void swap_io_context(struct io_context **ioc1, struct io_context **ioc2);

struct request;
107
typedef void (rq_end_io_fn)(struct request *, int);
L
Linus Torvalds 已提交
108 109 110 111

struct request_list {
	int count[2];
	int starved[2];
T
Tejun Heo 已提交
112
	int elvpriv;
L
Linus Torvalds 已提交
113 114 115 116 117 118 119 120 121 122
	mempool_t *rq_pool;
	wait_queue_head_t wait[2];
};

#define BLK_MAX_CDB	16

/*
 * try to put the fields that are referenced together in the same cacheline
 */
struct request {
123 124 125
	struct list_head queuelist;
	struct list_head donelist;

L
Linus Torvalds 已提交
126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145
	unsigned long flags;		/* see REQ_ bits below */

	/* Maintain bio traversal state for part by part I/O submission.
	 * hard_* are block layer internals, no driver should touch them!
	 */

	sector_t sector;		/* next sector to submit */
	unsigned long nr_sectors;	/* no. of sectors left to submit */
	/* no. of sectors left to submit in the current segment */
	unsigned int current_nr_sectors;

	sector_t hard_sector;		/* next sector to complete */
	unsigned long hard_nr_sectors;	/* no. of sectors left to complete */
	/* no. of sectors left to complete in the current segment */
	unsigned int hard_cur_sectors;

	struct bio *bio;
	struct bio *biotail;

	void *elevator_private;
146
	void *completion_data;
L
Linus Torvalds 已提交
147

148 149
	unsigned short ioprio;

L
Linus Torvalds 已提交
150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189
	int rq_status;	/* should split this into a few status bits */
	struct gendisk *rq_disk;
	int errors;
	unsigned long start_time;

	/* Number of scatter-gather DMA addr+len pairs after
	 * physical address coalescing is performed.
	 */
	unsigned short nr_phys_segments;

	/* Number of scatter-gather addr+len pairs after
	 * physical and DMA remapping hardware coalescing is performed.
	 * This is the number of scatter-gather entries the driver
	 * will actually have to deal with after DMA mapping is done.
	 */
	unsigned short nr_hw_segments;

	int tag;
	char *buffer;

	int ref_count;
	request_queue_t *q;
	struct request_list *rl;

	struct completion *waiting;
	void *special;

	/*
	 * when request is used as a packet command carrier
	 */
	unsigned int cmd_len;
	unsigned char cmd[BLK_MAX_CDB];

	unsigned int data_len;
	void *data;

	unsigned int sense_len;
	void *sense;

	unsigned int timeout;
190
	int retries;
L
Linus Torvalds 已提交
191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209

	/*
	 * For Power Management requests
	 */
	struct request_pm_state *pm;

	/*
	 * completion callback. end_io_data should be folded in with waiting
	 */
	rq_end_io_fn *end_io;
	void *end_io_data;
};

/*
 * first three bits match BIO_RW* bits, important
 */
enum rq_flag_bits {
	__REQ_RW,		/* not set, read. set, write */
	__REQ_FAILFAST,		/* no low level driver retries */
210
	__REQ_SORTED,		/* elevator knows about this request */
L
Linus Torvalds 已提交
211 212
	__REQ_SOFTBARRIER,	/* may not be passed by ioscheduler */
	__REQ_HARDBARRIER,	/* may not be passed by drive either */
213
	__REQ_FUA,		/* forced unit access */
L
Linus Torvalds 已提交
214 215 216 217 218
	__REQ_CMD,		/* is a regular fs rw request */
	__REQ_NOMERGE,		/* don't touch this for merging */
	__REQ_STARTED,		/* drive already may have started this one */
	__REQ_DONTPREP,		/* don't call prep for this one */
	__REQ_QUEUED,		/* uses queueing */
T
Tejun Heo 已提交
219
	__REQ_ELVPRIV,		/* elevator private data attached */
L
Linus Torvalds 已提交
220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236
	/*
	 * for ATA/ATAPI devices
	 */
	__REQ_PC,		/* packet command (special) */
	__REQ_BLOCK_PC,		/* queued down pc from block layer */
	__REQ_SENSE,		/* sense retrival */

	__REQ_FAILED,		/* set if the request failed */
	__REQ_QUIET,		/* don't worry about errors */
	__REQ_SPECIAL,		/* driver suplied command */
	__REQ_DRIVE_CMD,
	__REQ_DRIVE_TASK,
	__REQ_DRIVE_TASKFILE,
	__REQ_PREEMPT,		/* set for "ide_preempt" requests */
	__REQ_PM_SUSPEND,	/* suspend request */
	__REQ_PM_RESUME,	/* resume request */
	__REQ_PM_SHUTDOWN,	/* shutdown request */
237
	__REQ_ORDERED_COLOR,	/* is before or after barrier */
L
Linus Torvalds 已提交
238 239 240 241 242
	__REQ_NR_BITS,		/* stops here */
};

#define REQ_RW		(1 << __REQ_RW)
#define REQ_FAILFAST	(1 << __REQ_FAILFAST)
243
#define REQ_SORTED	(1 << __REQ_SORTED)
L
Linus Torvalds 已提交
244 245
#define REQ_SOFTBARRIER	(1 << __REQ_SOFTBARRIER)
#define REQ_HARDBARRIER	(1 << __REQ_HARDBARRIER)
246
#define REQ_FUA		(1 << __REQ_FUA)
L
Linus Torvalds 已提交
247 248 249 250 251
#define REQ_CMD		(1 << __REQ_CMD)
#define REQ_NOMERGE	(1 << __REQ_NOMERGE)
#define REQ_STARTED	(1 << __REQ_STARTED)
#define REQ_DONTPREP	(1 << __REQ_DONTPREP)
#define REQ_QUEUED	(1 << __REQ_QUEUED)
T
Tejun Heo 已提交
252
#define REQ_ELVPRIV	(1 << __REQ_ELVPRIV)
L
Linus Torvalds 已提交
253 254 255 256 257 258 259 260 261 262 263 264 265
#define REQ_PC		(1 << __REQ_PC)
#define REQ_BLOCK_PC	(1 << __REQ_BLOCK_PC)
#define REQ_SENSE	(1 << __REQ_SENSE)
#define REQ_FAILED	(1 << __REQ_FAILED)
#define REQ_QUIET	(1 << __REQ_QUIET)
#define REQ_SPECIAL	(1 << __REQ_SPECIAL)
#define REQ_DRIVE_CMD	(1 << __REQ_DRIVE_CMD)
#define REQ_DRIVE_TASK	(1 << __REQ_DRIVE_TASK)
#define REQ_DRIVE_TASKFILE	(1 << __REQ_DRIVE_TASKFILE)
#define REQ_PREEMPT	(1 << __REQ_PREEMPT)
#define REQ_PM_SUSPEND	(1 << __REQ_PM_SUSPEND)
#define REQ_PM_RESUME	(1 << __REQ_PM_RESUME)
#define REQ_PM_SHUTDOWN	(1 << __REQ_PM_SHUTDOWN)
266
#define REQ_ORDERED_COLOR	(1 << __REQ_ORDERED_COLOR)
L
Linus Torvalds 已提交
267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295

/*
 * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
 * requests. Some step values could eventually be made generic.
 */
struct request_pm_state
{
	/* PM state machine step value, currently driver specific */
	int	pm_step;
	/* requested PM state value (S1, S2, S3, S4, ...) */
	u32	pm_state;
	void*	data;		/* for driver use */
};

#include <linux/elevator.h>

typedef int (merge_request_fn) (request_queue_t *, struct request *,
				struct bio *);
typedef int (merge_requests_fn) (request_queue_t *, struct request *,
				 struct request *);
typedef void (request_fn_proc) (request_queue_t *q);
typedef int (make_request_fn) (request_queue_t *q, struct bio *bio);
typedef int (prep_rq_fn) (request_queue_t *, struct request *);
typedef void (unplug_fn) (request_queue_t *);

struct bio_vec;
typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
typedef void (activity_fn) (void *data, int rw);
typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
296
typedef void (prepare_flush_fn) (request_queue_t *, struct request *);
297
typedef void (softirq_done_fn)(struct request *);
L
Linus Torvalds 已提交
298 299 300 301 302 303 304 305 306 307 308 309

enum blk_queue_state {
	Queue_down,
	Queue_up,
};

struct blk_queue_tag {
	struct request **tag_index;	/* map of busy tags */
	unsigned long *tag_map;		/* bit map of free/busy tags */
	struct list_head busy_list;	/* fifo list of busy tags */
	int busy;			/* current depth */
	int max_depth;			/* what we will send to device */
310
	int real_max_depth;		/* what the array can hold */
L
Linus Torvalds 已提交
311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338
	atomic_t refcnt;		/* map can be shared */
};

struct request_queue
{
	/*
	 * Together with queue_head for cacheline sharing
	 */
	struct list_head	queue_head;
	struct request		*last_merge;
	elevator_t		*elevator;

	/*
	 * the queue request freelist, one for reads and one for writes
	 */
	struct request_list	rq;

	request_fn_proc		*request_fn;
	merge_request_fn	*back_merge_fn;
	merge_request_fn	*front_merge_fn;
	merge_requests_fn	*merge_requests_fn;
	make_request_fn		*make_request_fn;
	prep_rq_fn		*prep_rq_fn;
	unplug_fn		*unplug_fn;
	merge_bvec_fn		*merge_bvec_fn;
	activity_fn		*activity_fn;
	issue_flush_fn		*issue_flush_fn;
	prepare_flush_fn	*prepare_flush_fn;
339
	softirq_done_fn		*softirq_done_fn;
L
Linus Torvalds 已提交
340

341 342 343
	/*
	 * Dispatch queue sorting
	 */
J
Jens Axboe 已提交
344
	sector_t		end_sector;
345 346
	struct request		*boundary_rq;

L
Linus Torvalds 已提交
347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368
	/*
	 * Auto-unplugging state
	 */
	struct timer_list	unplug_timer;
	int			unplug_thresh;	/* After this many requests */
	unsigned long		unplug_delay;	/* After this many jiffies */
	struct work_struct	unplug_work;

	struct backing_dev_info	backing_dev_info;

	/*
	 * The queue owner gets to use this for whatever they like.
	 * ll_rw_blk doesn't touch it.
	 */
	void			*queuedata;

	void			*activity_data;

	/*
	 * queue needs bounce pages for pages above this limit
	 */
	unsigned long		bounce_pfn;
A
Al Viro 已提交
369
	gfp_t			bounce_gfp;
L
Linus Torvalds 已提交
370 371 372 373 374 375 376

	/*
	 * various queue flags, see QUEUE_* below
	 */
	unsigned long		queue_flags;

	/*
已提交
377 378 379
	 * protects queue structures from reentrancy. ->__queue_lock should
	 * _never_ be used directly, it is queue private. always use
	 * ->queue_lock.
L
Linus Torvalds 已提交
380
	 */
已提交
381
	spinlock_t		__queue_lock;
L
Linus Torvalds 已提交
382 383 384 385 386 387 388 389 390 391 392 393 394 395 396
	spinlock_t		*queue_lock;

	/*
	 * queue kobject
	 */
	struct kobject kobj;

	/*
	 * queue settings
	 */
	unsigned long		nr_requests;	/* Max # of requests */
	unsigned int		nr_congestion_on;
	unsigned int		nr_congestion_off;
	unsigned int		nr_batching;

397 398
	unsigned int		max_sectors;
	unsigned int		max_hw_sectors;
L
Linus Torvalds 已提交
399 400 401 402 403 404 405 406 407 408
	unsigned short		max_phys_segments;
	unsigned short		max_hw_segments;
	unsigned short		hardsect_size;
	unsigned int		max_segment_size;

	unsigned long		seg_boundary_mask;
	unsigned int		dma_alignment;

	struct blk_queue_tag	*queue_tags;

409
	unsigned int		nr_sorted;
L
Linus Torvalds 已提交
410 411 412 413 414 415 416
	unsigned int		in_flight;

	/*
	 * sg stuff
	 */
	unsigned int		sg_timeout;
	unsigned int		sg_reserved_size;
417
	int			node;
L
Linus Torvalds 已提交
418 419 420 421

	/*
	 * reserved for flush operations
	 */
422 423 424 425 426
	unsigned int		ordered, next_ordered, ordseq;
	int			orderr, ordcolor;
	struct request		pre_flush_rq, bar_rq, post_flush_rq;
	struct request		*orig_bar_rq;
	unsigned int		bi_size;
427 428

	struct mutex		sysfs_lock;
L
Linus Torvalds 已提交
429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444
};

#define RQ_INACTIVE		(-1)
#define RQ_ACTIVE		1
#define RQ_SCSI_BUSY		0xffff
#define RQ_SCSI_DONE		0xfffe
#define RQ_SCSI_DISCONNECTING	0xffe0

#define QUEUE_FLAG_CLUSTER	0	/* cluster several segments into 1 */
#define QUEUE_FLAG_QUEUED	1	/* uses generic tag queueing */
#define QUEUE_FLAG_STOPPED	2	/* queue is stopped */
#define	QUEUE_FLAG_READFULL	3	/* write queue has been filled */
#define QUEUE_FLAG_WRITEFULL	4	/* read queue has been filled */
#define QUEUE_FLAG_DEAD		5	/* queue being torn down */
#define QUEUE_FLAG_REENTER	6	/* Re-entrancy avoidance */
#define QUEUE_FLAG_PLUGGED	7	/* queue is plugged */
J
Jens Axboe 已提交
445
#define QUEUE_FLAG_ELVSWITCH	8	/* don't use elevator, just do FIFO */
446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485

enum {
	/*
	 * Hardbarrier is supported with one of the following methods.
	 *
	 * NONE		: hardbarrier unsupported
	 * DRAIN	: ordering by draining is enough
	 * DRAIN_FLUSH	: ordering by draining w/ pre and post flushes
	 * DRAIN_FUA	: ordering by draining w/ pre flush and FUA write
	 * TAG		: ordering by tag is enough
	 * TAG_FLUSH	: ordering by tag w/ pre and post flushes
	 * TAG_FUA	: ordering by tag w/ pre flush and FUA write
	 */
	QUEUE_ORDERED_NONE	= 0x00,
	QUEUE_ORDERED_DRAIN	= 0x01,
	QUEUE_ORDERED_TAG	= 0x02,

	QUEUE_ORDERED_PREFLUSH	= 0x10,
	QUEUE_ORDERED_POSTFLUSH	= 0x20,
	QUEUE_ORDERED_FUA	= 0x40,

	QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
			QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
	QUEUE_ORDERED_DRAIN_FUA	= QUEUE_ORDERED_DRAIN |
			QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
	QUEUE_ORDERED_TAG_FLUSH	= QUEUE_ORDERED_TAG |
			QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
	QUEUE_ORDERED_TAG_FUA	= QUEUE_ORDERED_TAG |
			QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,

	/*
	 * Ordered operation sequence
	 */
	QUEUE_ORDSEQ_STARTED	= 0x01,	/* flushing in progress */
	QUEUE_ORDSEQ_DRAIN	= 0x02,	/* waiting for the queue to be drained */
	QUEUE_ORDSEQ_PREFLUSH	= 0x04,	/* pre-flushing in progress */
	QUEUE_ORDSEQ_BAR	= 0x08,	/* original barrier req in progress */
	QUEUE_ORDSEQ_POSTFLUSH	= 0x10,	/* post-flushing in progress */
	QUEUE_ORDSEQ_DONE	= 0x20,
};
L
Linus Torvalds 已提交
486 487 488 489

#define blk_queue_plugged(q)	test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
#define blk_queue_tagged(q)	test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
#define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
490
#define blk_queue_flushing(q)	((q)->ordseq)
L
Linus Torvalds 已提交
491 492 493 494 495 496 497 498 499 500 501 502 503

#define blk_fs_request(rq)	((rq)->flags & REQ_CMD)
#define blk_pc_request(rq)	((rq)->flags & REQ_BLOCK_PC)
#define blk_noretry_request(rq)	((rq)->flags & REQ_FAILFAST)
#define blk_rq_started(rq)	((rq)->flags & REQ_STARTED)

#define blk_account_rq(rq)	(blk_rq_started(rq) && blk_fs_request(rq))

#define blk_pm_suspend_request(rq)	((rq)->flags & REQ_PM_SUSPEND)
#define blk_pm_resume_request(rq)	((rq)->flags & REQ_PM_RESUME)
#define blk_pm_request(rq)	\
	((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))

504
#define blk_sorted_rq(rq)	((rq)->flags & REQ_SORTED)
L
Linus Torvalds 已提交
505
#define blk_barrier_rq(rq)	((rq)->flags & REQ_HARDBARRIER)
506
#define blk_fua_rq(rq)		((rq)->flags & REQ_FUA)
L
Linus Torvalds 已提交
507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597

#define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)

#define rq_data_dir(rq)		((rq)->flags & 1)

static inline int blk_queue_full(struct request_queue *q, int rw)
{
	if (rw == READ)
		return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
	return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
}

static inline void blk_set_queue_full(struct request_queue *q, int rw)
{
	if (rw == READ)
		set_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
	else
		set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
}

static inline void blk_clear_queue_full(struct request_queue *q, int rw)
{
	if (rw == READ)
		clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags);
	else
		clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags);
}


/*
 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
 * it already be started by driver.
 */
#define RQ_NOMERGE_FLAGS	\
	(REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
#define rq_mergeable(rq)	\
	(!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))

/*
 * noop, requests are automagically marked as active/inactive by I/O
 * scheduler -- see elv_next_request
 */
#define blk_queue_headactive(q, head_active)

/*
 * q->prep_rq_fn return values
 */
#define BLKPREP_OK		0	/* serve it */
#define BLKPREP_KILL		1	/* fatal error, kill */
#define BLKPREP_DEFER		2	/* leave on queue */

extern unsigned long blk_max_low_pfn, blk_max_pfn;

/*
 * standard bounce addresses:
 *
 * BLK_BOUNCE_HIGH	: bounce all highmem pages
 * BLK_BOUNCE_ANY	: don't bounce anything
 * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
 */
#define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
#define BLK_BOUNCE_ANY		((u64)blk_max_pfn << PAGE_SHIFT)
#define BLK_BOUNCE_ISA		(ISA_DMA_THRESHOLD)

#ifdef CONFIG_MMU
extern int init_emergency_isa_pool(void);
extern void blk_queue_bounce(request_queue_t *q, struct bio **bio);
#else
static inline int init_emergency_isa_pool(void)
{
	return 0;
}
static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio)
{
}
#endif /* CONFIG_MMU */

#define rq_for_each_bio(_bio, rq)	\
	if ((rq->bio))			\
		for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)

struct sec_size {
	unsigned block_size;
	unsigned block_size_bits;
};

extern int blk_register_queue(struct gendisk *disk);
extern void blk_unregister_queue(struct gendisk *disk);
extern void register_disk(struct gendisk *dev);
extern void generic_make_request(struct bio *bio);
extern void blk_put_request(struct request *);
598
extern void __blk_put_request(request_queue_t *, struct request *);
599
extern void blk_end_sync_rq(struct request *rq, int error);
A
Al Viro 已提交
600
extern struct request *blk_get_request(request_queue_t *, int, gfp_t);
601
extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
L
Linus Torvalds 已提交
602 603 604 605 606 607 608 609 610 611 612
extern void blk_requeue_request(request_queue_t *, struct request *);
extern void blk_plug_device(request_queue_t *);
extern int blk_remove_plug(request_queue_t *);
extern void blk_recount_segments(request_queue_t *, struct bio *);
extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
extern void blk_start_queue(request_queue_t *q);
extern void blk_stop_queue(request_queue_t *q);
extern void blk_sync_queue(struct request_queue *q);
extern void __blk_stop_queue(request_queue_t *q);
extern void blk_run_queue(request_queue_t *);
extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);
613 614
extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int);
extern int blk_rq_unmap_user(struct bio *, unsigned int);
A
Al Viro 已提交
615
extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, gfp_t);
616
extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int);
617 618
extern int blk_execute_rq(request_queue_t *, struct gendisk *,
			  struct request *, int);
619
extern void blk_execute_rq_nowait(request_queue_t *, struct gendisk *,
620
				  struct request *, int, rq_end_io_fn *);
621

L
Linus Torvalds 已提交
622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650
static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
{
	return bdev->bd_disk->queue;
}

static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
				       struct page *page)
{
	if (bdi && bdi->unplug_io_fn)
		bdi->unplug_io_fn(bdi, page);
}

static inline void blk_run_address_space(struct address_space *mapping)
{
	if (mapping)
		blk_run_backing_dev(mapping->backing_dev_info, NULL);
}

/*
 * end_request() and friends. Must be called with the request queue spinlock
 * acquired. All functions called within end_request() _must_be_ atomic.
 *
 * Several drivers define their own end_request and call
 * end_that_request_first() and end_that_request_last()
 * for parts of the original function. This prevents
 * code duplication in drivers.
 */
extern int end_that_request_first(struct request *, int, int);
extern int end_that_request_chunk(struct request *, int, int);
651
extern void end_that_request_last(struct request *, int);
L
Linus Torvalds 已提交
652
extern void end_request(struct request *req, int uptodate);
653 654 655 656 657 658 659 660 661 662 663
extern void blk_complete_request(struct request *);

static inline int rq_all_done(struct request *rq, unsigned int nr_bytes)
{
	if (blk_fs_request(rq))
		return (nr_bytes >= (rq->hard_nr_sectors << 9));
	else if (blk_pc_request(rq))
		return nr_bytes >= rq->data_len;

	return 0;
}
L
Linus Torvalds 已提交
664 665 666 667 668 669 670 671 672 673 674

/*
 * end_that_request_first/chunk() takes an uptodate argument. we account
 * any value <= as an io error. 0 means -EIO for compatability reasons,
 * any other < 0 value is the direct error type. An uptodate value of
 * 1 indicates successful io completion
 */
#define end_io_error(uptodate)	(unlikely((uptodate) <= 0))

static inline void blkdev_dequeue_request(struct request *req)
{
675
	elv_dequeue_request(req->q, req);
L
Linus Torvalds 已提交
676 677
}

J
Jens Axboe 已提交
678 679 680 681 682 683
/*
 * This should be in elevator.h, but that requires pulling in rq and q
 */
static inline void elv_dispatch_add_tail(struct request_queue *q,
					 struct request *rq)
{
684 685
	if (q->last_merge == rq)
		q->last_merge = NULL;
686
	q->nr_sorted--;
L
Linus Torvalds 已提交
687

J
Jens Axboe 已提交
688 689 690
	q->end_sector = rq_end_sector(rq);
	q->boundary_rq = rq;
	list_add_tail(&rq->queuelist, &q->queue_head);
L
Linus Torvalds 已提交
691 692 693 694 695
}

/*
 * Access functions for manipulating queue properties
 */
696 697
extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn,
					spinlock_t *lock, int node_id);
L
Linus Torvalds 已提交
698 699 700 701
extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *);
extern void blk_cleanup_queue(request_queue_t *);
extern void blk_queue_make_request(request_queue_t *, make_request_fn *);
extern void blk_queue_bounce_limit(request_queue_t *, u64);
702
extern void blk_queue_max_sectors(request_queue_t *, unsigned int);
L
Linus Torvalds 已提交
703 704 705 706 707 708 709 710 711
extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short);
extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short);
extern void blk_queue_max_segment_size(request_queue_t *, unsigned int);
extern void blk_queue_hardsect_size(request_queue_t *, unsigned short);
extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b);
extern void blk_queue_segment_boundary(request_queue_t *, unsigned long);
extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
extern void blk_queue_dma_alignment(request_queue_t *, int);
712
extern void blk_queue_softirq_done(request_queue_t *, softirq_done_fn *);
L
Linus Torvalds 已提交
713
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
714
extern int blk_queue_ordered(request_queue_t *, unsigned, prepare_flush_fn *);
L
Linus Torvalds 已提交
715
extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *);
716 717 718 719
extern int blk_do_ordered(request_queue_t *, struct request **);
extern unsigned blk_ordered_cur_seq(request_queue_t *);
extern unsigned blk_ordered_req_seq(struct request *);
extern void blk_ordered_complete_seq(request_queue_t *, unsigned, int);
L
Linus Torvalds 已提交
720 721 722 723 724 725 726 727

extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
extern void blk_dump_rq_flags(struct request *, char *);
extern void generic_unplug_device(request_queue_t *);
extern void __generic_unplug_device(request_queue_t *);
extern long nr_blockdev_pages(void);

int blk_get_queue(request_queue_t *);
A
Al Viro 已提交
728 729
request_queue_t *blk_alloc_queue(gfp_t);
request_queue_t *blk_alloc_queue_node(gfp_t, int);
730
extern void blk_put_queue(request_queue_t *);
L
Linus Torvalds 已提交
731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751

/*
 * tag stuff
 */
#define blk_queue_tag_depth(q)		((q)->queue_tags->busy)
#define blk_queue_tag_queue(q)		((q)->queue_tags->busy < (q)->queue_tags->max_depth)
#define blk_rq_tagged(rq)		((rq)->flags & REQ_QUEUED)
extern int blk_queue_start_tag(request_queue_t *, struct request *);
extern struct request *blk_queue_find_tag(request_queue_t *, int);
extern void blk_queue_end_tag(request_queue_t *, struct request *);
extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *);
extern void blk_queue_free_tags(request_queue_t *);
extern int blk_queue_resize_tags(request_queue_t *, int);
extern void blk_queue_invalidate_tags(request_queue_t *);
extern long blk_congestion_wait(int rw, long timeout);

extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
extern int blkdev_issue_flush(struct block_device *, sector_t *);

#define MAX_PHYS_SEGMENTS 128
#define MAX_HW_SEGMENTS 128
752 753
#define SAFE_MAX_SECTORS 255
#define BLK_DEF_MAX_SECTORS 1024
L
Linus Torvalds 已提交
754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802

#define MAX_SEGMENT_SIZE	65536

#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)

static inline int queue_hardsect_size(request_queue_t *q)
{
	int retval = 512;

	if (q && q->hardsect_size)
		retval = q->hardsect_size;

	return retval;
}

static inline int bdev_hardsect_size(struct block_device *bdev)
{
	return queue_hardsect_size(bdev_get_queue(bdev));
}

static inline int queue_dma_alignment(request_queue_t *q)
{
	int retval = 511;

	if (q && q->dma_alignment)
		retval = q->dma_alignment;

	return retval;
}

static inline int bdev_dma_aligment(struct block_device *bdev)
{
	return queue_dma_alignment(bdev_get_queue(bdev));
}

#define blk_finished_io(nsects)	do { } while (0)
#define blk_started_io(nsects)	do { } while (0)

/* assumes size > 256 */
static inline unsigned int blksize_bits(unsigned int size)
{
	unsigned int bits = 8;
	do {
		bits++;
		size >>= 1;
	} while (size > 256);
	return bits;
}

803
static inline unsigned int block_size(struct block_device *bdev)
L
Linus Torvalds 已提交
804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841
{
	return bdev->bd_block_size;
}

typedef struct {struct page *v;} Sector;

unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);

static inline void put_dev_sector(Sector p)
{
	page_cache_release(p.v);
}

struct work_struct;
int kblockd_schedule_work(struct work_struct *work);
void kblockd_flush(void);

#ifdef CONFIG_LBD
# include <asm/div64.h>
# define sector_div(a, b) do_div(a, b)
#else
# define sector_div(n, b)( \
{ \
	int _res; \
	_res = (n) % (b); \
	(n) /= (b); \
	_res; \
} \
)
#endif 

#define MODULE_ALIAS_BLOCKDEV(major,minor) \
	MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
	MODULE_ALIAS("block-major-" __stringify(major) "-*")


#endif