Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | /* |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 358 | * protects queue structures from reentrancy. ->__queue_lock should |
| 359 | * _never_ be used directly, it is queue private. always use |
| 360 | * ->queue_lock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | */ |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 362 | spinlock_t __queue_lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Christoph Lameter | 1946089 | 2005-06-23 00:08:19 -0700 | [diff] [blame^] | 399 | int node; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | |
| 401 | struct list_head drain_list; |
| 402 | |
| 403 | /* |
| 404 | * reserved for flush operations |
| 405 | */ |
| 406 | struct request *flush_rq; |
| 407 | unsigned char ordered; |
| 408 | }; |
| 409 | |
| 410 | enum { |
| 411 | QUEUE_ORDERED_NONE, |
| 412 | QUEUE_ORDERED_TAG, |
| 413 | QUEUE_ORDERED_FLUSH, |
| 414 | }; |
| 415 | |
| 416 | #define RQ_INACTIVE (-1) |
| 417 | #define RQ_ACTIVE 1 |
| 418 | #define RQ_SCSI_BUSY 0xffff |
| 419 | #define RQ_SCSI_DONE 0xfffe |
| 420 | #define RQ_SCSI_DISCONNECTING 0xffe0 |
| 421 | |
| 422 | #define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */ |
| 423 | #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ |
| 424 | #define QUEUE_FLAG_STOPPED 2 /* queue is stopped */ |
| 425 | #define QUEUE_FLAG_READFULL 3 /* write queue has been filled */ |
| 426 | #define QUEUE_FLAG_WRITEFULL 4 /* read queue has been filled */ |
| 427 | #define QUEUE_FLAG_DEAD 5 /* queue being torn down */ |
| 428 | #define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */ |
| 429 | #define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */ |
| 430 | #define QUEUE_FLAG_DRAIN 8 /* draining queue for sched switch */ |
| 431 | #define QUEUE_FLAG_FLUSH 9 /* doing barrier flush sequence */ |
| 432 | |
| 433 | #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) |
| 434 | #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) |
| 435 | #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) |
| 436 | #define blk_queue_flushing(q) test_bit(QUEUE_FLAG_FLUSH, &(q)->queue_flags) |
| 437 | |
| 438 | #define blk_fs_request(rq) ((rq)->flags & REQ_CMD) |
| 439 | #define blk_pc_request(rq) ((rq)->flags & REQ_BLOCK_PC) |
| 440 | #define blk_noretry_request(rq) ((rq)->flags & REQ_FAILFAST) |
| 441 | #define blk_rq_started(rq) ((rq)->flags & REQ_STARTED) |
| 442 | |
| 443 | #define blk_account_rq(rq) (blk_rq_started(rq) && blk_fs_request(rq)) |
| 444 | |
| 445 | #define blk_pm_suspend_request(rq) ((rq)->flags & REQ_PM_SUSPEND) |
| 446 | #define blk_pm_resume_request(rq) ((rq)->flags & REQ_PM_RESUME) |
| 447 | #define blk_pm_request(rq) \ |
| 448 | ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME)) |
| 449 | |
| 450 | #define blk_barrier_rq(rq) ((rq)->flags & REQ_HARDBARRIER) |
| 451 | #define blk_barrier_preflush(rq) ((rq)->flags & REQ_BAR_PREFLUSH) |
| 452 | #define blk_barrier_postflush(rq) ((rq)->flags & REQ_BAR_POSTFLUSH) |
| 453 | |
| 454 | #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) |
| 455 | |
| 456 | #define rq_data_dir(rq) ((rq)->flags & 1) |
| 457 | |
| 458 | static inline int blk_queue_full(struct request_queue *q, int rw) |
| 459 | { |
| 460 | if (rw == READ) |
| 461 | return test_bit(QUEUE_FLAG_READFULL, &q->queue_flags); |
| 462 | return test_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); |
| 463 | } |
| 464 | |
| 465 | static inline void blk_set_queue_full(struct request_queue *q, int rw) |
| 466 | { |
| 467 | if (rw == READ) |
| 468 | set_bit(QUEUE_FLAG_READFULL, &q->queue_flags); |
| 469 | else |
| 470 | set_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); |
| 471 | } |
| 472 | |
| 473 | static inline void blk_clear_queue_full(struct request_queue *q, int rw) |
| 474 | { |
| 475 | if (rw == READ) |
| 476 | clear_bit(QUEUE_FLAG_READFULL, &q->queue_flags); |
| 477 | else |
| 478 | clear_bit(QUEUE_FLAG_WRITEFULL, &q->queue_flags); |
| 479 | } |
| 480 | |
| 481 | |
| 482 | /* |
| 483 | * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may |
| 484 | * it already be started by driver. |
| 485 | */ |
| 486 | #define RQ_NOMERGE_FLAGS \ |
| 487 | (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER) |
| 488 | #define rq_mergeable(rq) \ |
| 489 | (!((rq)->flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq))) |
| 490 | |
| 491 | /* |
| 492 | * noop, requests are automagically marked as active/inactive by I/O |
| 493 | * scheduler -- see elv_next_request |
| 494 | */ |
| 495 | #define blk_queue_headactive(q, head_active) |
| 496 | |
| 497 | /* |
| 498 | * q->prep_rq_fn return values |
| 499 | */ |
| 500 | #define BLKPREP_OK 0 /* serve it */ |
| 501 | #define BLKPREP_KILL 1 /* fatal error, kill */ |
| 502 | #define BLKPREP_DEFER 2 /* leave on queue */ |
| 503 | |
| 504 | extern unsigned long blk_max_low_pfn, blk_max_pfn; |
| 505 | |
| 506 | /* |
| 507 | * standard bounce addresses: |
| 508 | * |
| 509 | * BLK_BOUNCE_HIGH : bounce all highmem pages |
| 510 | * BLK_BOUNCE_ANY : don't bounce anything |
| 511 | * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary |
| 512 | */ |
| 513 | #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) |
| 514 | #define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) |
| 515 | #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) |
| 516 | |
| 517 | #ifdef CONFIG_MMU |
| 518 | extern int init_emergency_isa_pool(void); |
| 519 | extern void blk_queue_bounce(request_queue_t *q, struct bio **bio); |
| 520 | #else |
| 521 | static inline int init_emergency_isa_pool(void) |
| 522 | { |
| 523 | return 0; |
| 524 | } |
| 525 | static inline void blk_queue_bounce(request_queue_t *q, struct bio **bio) |
| 526 | { |
| 527 | } |
| 528 | #endif /* CONFIG_MMU */ |
| 529 | |
| 530 | #define rq_for_each_bio(_bio, rq) \ |
| 531 | if ((rq->bio)) \ |
| 532 | for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) |
| 533 | |
| 534 | struct sec_size { |
| 535 | unsigned block_size; |
| 536 | unsigned block_size_bits; |
| 537 | }; |
| 538 | |
| 539 | extern int blk_register_queue(struct gendisk *disk); |
| 540 | extern void blk_unregister_queue(struct gendisk *disk); |
| 541 | extern void register_disk(struct gendisk *dev); |
| 542 | extern void generic_make_request(struct bio *bio); |
| 543 | extern void blk_put_request(struct request *); |
| 544 | extern void blk_end_sync_rq(struct request *rq); |
| 545 | extern void blk_attempt_remerge(request_queue_t *, struct request *); |
| 546 | extern void __blk_attempt_remerge(request_queue_t *, struct request *); |
| 547 | extern struct request *blk_get_request(request_queue_t *, int, int); |
Tejun Heo | 867d119 | 2005-04-24 02:06:05 -0500 | [diff] [blame] | 548 | extern void blk_insert_request(request_queue_t *, struct request *, int, void *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | extern void blk_requeue_request(request_queue_t *, struct request *); |
| 550 | extern void blk_plug_device(request_queue_t *); |
| 551 | extern int blk_remove_plug(request_queue_t *); |
| 552 | extern void blk_recount_segments(request_queue_t *, struct bio *); |
| 553 | extern int blk_phys_contig_segment(request_queue_t *q, struct bio *, struct bio *); |
| 554 | extern int blk_hw_contig_segment(request_queue_t *q, struct bio *, struct bio *); |
| 555 | extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *); |
| 556 | extern void blk_start_queue(request_queue_t *q); |
| 557 | extern void blk_stop_queue(request_queue_t *q); |
| 558 | extern void blk_sync_queue(struct request_queue *q); |
| 559 | extern void __blk_stop_queue(request_queue_t *q); |
| 560 | extern void blk_run_queue(request_queue_t *); |
| 561 | extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); |
| 562 | extern struct request *blk_rq_map_user(request_queue_t *, int, void __user *, unsigned int); |
| 563 | extern int blk_rq_unmap_user(struct request *, struct bio *, unsigned int); |
| 564 | extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *); |
| 565 | |
| 566 | static inline request_queue_t *bdev_get_queue(struct block_device *bdev) |
| 567 | { |
| 568 | return bdev->bd_disk->queue; |
| 569 | } |
| 570 | |
| 571 | static inline void blk_run_backing_dev(struct backing_dev_info *bdi, |
| 572 | struct page *page) |
| 573 | { |
| 574 | if (bdi && bdi->unplug_io_fn) |
| 575 | bdi->unplug_io_fn(bdi, page); |
| 576 | } |
| 577 | |
| 578 | static inline void blk_run_address_space(struct address_space *mapping) |
| 579 | { |
| 580 | if (mapping) |
| 581 | blk_run_backing_dev(mapping->backing_dev_info, NULL); |
| 582 | } |
| 583 | |
| 584 | /* |
| 585 | * end_request() and friends. Must be called with the request queue spinlock |
| 586 | * acquired. All functions called within end_request() _must_be_ atomic. |
| 587 | * |
| 588 | * Several drivers define their own end_request and call |
| 589 | * end_that_request_first() and end_that_request_last() |
| 590 | * for parts of the original function. This prevents |
| 591 | * code duplication in drivers. |
| 592 | */ |
| 593 | extern int end_that_request_first(struct request *, int, int); |
| 594 | extern int end_that_request_chunk(struct request *, int, int); |
| 595 | extern void end_that_request_last(struct request *); |
| 596 | extern void end_request(struct request *req, int uptodate); |
| 597 | |
| 598 | /* |
| 599 | * end_that_request_first/chunk() takes an uptodate argument. we account |
| 600 | * any value <= as an io error. 0 means -EIO for compatability reasons, |
| 601 | * any other < 0 value is the direct error type. An uptodate value of |
| 602 | * 1 indicates successful io completion |
| 603 | */ |
| 604 | #define end_io_error(uptodate) (unlikely((uptodate) <= 0)) |
| 605 | |
| 606 | static inline void blkdev_dequeue_request(struct request *req) |
| 607 | { |
| 608 | BUG_ON(list_empty(&req->queuelist)); |
| 609 | |
| 610 | list_del_init(&req->queuelist); |
| 611 | |
| 612 | if (req->rl) |
| 613 | elv_remove_request(req->q, req); |
| 614 | } |
| 615 | |
| 616 | /* |
| 617 | * Access functions for manipulating queue properties |
| 618 | */ |
Christoph Lameter | 1946089 | 2005-06-23 00:08:19 -0700 | [diff] [blame^] | 619 | extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn, |
| 620 | spinlock_t *lock, int node_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | extern request_queue_t *blk_init_queue(request_fn_proc *, spinlock_t *); |
| 622 | extern void blk_cleanup_queue(request_queue_t *); |
| 623 | extern void blk_queue_make_request(request_queue_t *, make_request_fn *); |
| 624 | extern void blk_queue_bounce_limit(request_queue_t *, u64); |
| 625 | extern void blk_queue_max_sectors(request_queue_t *, unsigned short); |
| 626 | extern void blk_queue_max_phys_segments(request_queue_t *, unsigned short); |
| 627 | extern void blk_queue_max_hw_segments(request_queue_t *, unsigned short); |
| 628 | extern void blk_queue_max_segment_size(request_queue_t *, unsigned int); |
| 629 | extern void blk_queue_hardsect_size(request_queue_t *, unsigned short); |
| 630 | extern void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b); |
| 631 | extern void blk_queue_segment_boundary(request_queue_t *, unsigned long); |
| 632 | extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn); |
| 633 | extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *); |
| 634 | extern void blk_queue_dma_alignment(request_queue_t *, int); |
| 635 | extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); |
| 636 | extern void blk_queue_ordered(request_queue_t *, int); |
| 637 | extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *); |
| 638 | extern int blkdev_scsi_issue_flush_fn(request_queue_t *, struct gendisk *, sector_t *); |
| 639 | extern struct request *blk_start_pre_flush(request_queue_t *,struct request *); |
| 640 | extern int blk_complete_barrier_rq(request_queue_t *, struct request *, int); |
| 641 | extern int blk_complete_barrier_rq_locked(request_queue_t *, struct request *, int); |
| 642 | |
| 643 | extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); |
| 644 | extern void blk_dump_rq_flags(struct request *, char *); |
| 645 | extern void generic_unplug_device(request_queue_t *); |
| 646 | extern void __generic_unplug_device(request_queue_t *); |
| 647 | extern long nr_blockdev_pages(void); |
| 648 | extern void blk_wait_queue_drained(request_queue_t *, int); |
| 649 | extern void blk_finish_queue_drain(request_queue_t *); |
| 650 | |
| 651 | int blk_get_queue(request_queue_t *); |
Christoph Lameter | 1946089 | 2005-06-23 00:08:19 -0700 | [diff] [blame^] | 652 | request_queue_t *blk_alloc_queue(int gfp_mask); |
| 653 | request_queue_t *blk_alloc_queue_node(int,int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 654 | #define blk_put_queue(q) blk_cleanup_queue((q)) |
| 655 | |
| 656 | /* |
| 657 | * tag stuff |
| 658 | */ |
| 659 | #define blk_queue_tag_depth(q) ((q)->queue_tags->busy) |
| 660 | #define blk_queue_tag_queue(q) ((q)->queue_tags->busy < (q)->queue_tags->max_depth) |
| 661 | #define blk_rq_tagged(rq) ((rq)->flags & REQ_QUEUED) |
| 662 | extern int blk_queue_start_tag(request_queue_t *, struct request *); |
| 663 | extern struct request *blk_queue_find_tag(request_queue_t *, int); |
| 664 | extern void blk_queue_end_tag(request_queue_t *, struct request *); |
| 665 | extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *); |
| 666 | extern void blk_queue_free_tags(request_queue_t *); |
| 667 | extern int blk_queue_resize_tags(request_queue_t *, int); |
| 668 | extern void blk_queue_invalidate_tags(request_queue_t *); |
| 669 | extern long blk_congestion_wait(int rw, long timeout); |
| 670 | |
| 671 | extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); |
| 672 | extern int blkdev_issue_flush(struct block_device *, sector_t *); |
| 673 | |
| 674 | #define MAX_PHYS_SEGMENTS 128 |
| 675 | #define MAX_HW_SEGMENTS 128 |
| 676 | #define MAX_SECTORS 255 |
| 677 | |
| 678 | #define MAX_SEGMENT_SIZE 65536 |
| 679 | |
| 680 | #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) |
| 681 | |
| 682 | extern void drive_stat_acct(struct request *, int, int); |
| 683 | |
| 684 | static inline int queue_hardsect_size(request_queue_t *q) |
| 685 | { |
| 686 | int retval = 512; |
| 687 | |
| 688 | if (q && q->hardsect_size) |
| 689 | retval = q->hardsect_size; |
| 690 | |
| 691 | return retval; |
| 692 | } |
| 693 | |
| 694 | static inline int bdev_hardsect_size(struct block_device *bdev) |
| 695 | { |
| 696 | return queue_hardsect_size(bdev_get_queue(bdev)); |
| 697 | } |
| 698 | |
| 699 | static inline int queue_dma_alignment(request_queue_t *q) |
| 700 | { |
| 701 | int retval = 511; |
| 702 | |
| 703 | if (q && q->dma_alignment) |
| 704 | retval = q->dma_alignment; |
| 705 | |
| 706 | return retval; |
| 707 | } |
| 708 | |
| 709 | static inline int bdev_dma_aligment(struct block_device *bdev) |
| 710 | { |
| 711 | return queue_dma_alignment(bdev_get_queue(bdev)); |
| 712 | } |
| 713 | |
| 714 | #define blk_finished_io(nsects) do { } while (0) |
| 715 | #define blk_started_io(nsects) do { } while (0) |
| 716 | |
| 717 | /* assumes size > 256 */ |
| 718 | static inline unsigned int blksize_bits(unsigned int size) |
| 719 | { |
| 720 | unsigned int bits = 8; |
| 721 | do { |
| 722 | bits++; |
| 723 | size >>= 1; |
| 724 | } while (size > 256); |
| 725 | return bits; |
| 726 | } |
| 727 | |
| 728 | extern inline unsigned int block_size(struct block_device *bdev) |
| 729 | { |
| 730 | return bdev->bd_block_size; |
| 731 | } |
| 732 | |
| 733 | typedef struct {struct page *v;} Sector; |
| 734 | |
| 735 | unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *); |
| 736 | |
| 737 | static inline void put_dev_sector(Sector p) |
| 738 | { |
| 739 | page_cache_release(p.v); |
| 740 | } |
| 741 | |
| 742 | struct work_struct; |
| 743 | int kblockd_schedule_work(struct work_struct *work); |
| 744 | void kblockd_flush(void); |
| 745 | |
| 746 | #ifdef CONFIG_LBD |
| 747 | # include <asm/div64.h> |
| 748 | # define sector_div(a, b) do_div(a, b) |
| 749 | #else |
| 750 | # define sector_div(n, b)( \ |
| 751 | { \ |
| 752 | int _res; \ |
| 753 | _res = (n) % (b); \ |
| 754 | (n) /= (b); \ |
| 755 | _res; \ |
| 756 | } \ |
| 757 | ) |
| 758 | #endif |
| 759 | |
| 760 | #define MODULE_ALIAS_BLOCKDEV(major,minor) \ |
| 761 | MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor)) |
| 762 | #define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \ |
| 763 | MODULE_ALIAS("block-major-" __stringify(major) "-*") |
| 764 | |
| 765 | |
| 766 | #endif |