ide-io.c revision 22aa4b32a19b1f231d4ce7e9af6354b577a22a35
1/* 2 * IDE I/O functions 3 * 4 * Basic PIO and command management functionality. 5 * 6 * This code was split off from ide.c. See ide.c for history and original 7 * copyrights. 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License as published by the 11 * Free Software Foundation; either version 2, or (at your option) any 12 * later version. 13 * 14 * This program is distributed in the hope that it will be useful, but 15 * WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * General Public License for more details. 18 * 19 * For the avoidance of doubt the "preferred form" of this code is one which 20 * is in an open non patent encumbered format. Where cryptographic key signing 21 * forms part of the process of creating an executable the information 22 * including keys needed to generate an equivalently functional executable 23 * are deemed to be part of the source code. 24 */ 25 26 27#include <linux/module.h> 28#include <linux/types.h> 29#include <linux/string.h> 30#include <linux/kernel.h> 31#include <linux/timer.h> 32#include <linux/mm.h> 33#include <linux/interrupt.h> 34#include <linux/major.h> 35#include <linux/errno.h> 36#include <linux/genhd.h> 37#include <linux/blkpg.h> 38#include <linux/slab.h> 39#include <linux/init.h> 40#include <linux/pci.h> 41#include <linux/delay.h> 42#include <linux/ide.h> 43#include <linux/hdreg.h> 44#include <linux/completion.h> 45#include <linux/reboot.h> 46#include <linux/cdrom.h> 47#include <linux/seq_file.h> 48#include <linux/device.h> 49#include <linux/kmod.h> 50#include <linux/scatterlist.h> 51#include <linux/bitops.h> 52 53#include <asm/byteorder.h> 54#include <asm/irq.h> 55#include <asm/uaccess.h> 56#include <asm/io.h> 57 58static int __ide_end_request(ide_drive_t *drive, struct request *rq, 59 int uptodate, unsigned int nr_bytes, int dequeue) 60{ 61 int ret = 1; 62 int error = 0; 63 64 if (uptodate <= 0) 65 error = uptodate ? uptodate : -EIO; 66 67 /* 68 * if failfast is set on a request, override number of sectors and 69 * complete the whole request right now 70 */ 71 if (blk_noretry_request(rq) && error) 72 nr_bytes = rq->hard_nr_sectors << 9; 73 74 if (!blk_fs_request(rq) && error && !rq->errors) 75 rq->errors = -EIO; 76 77 /* 78 * decide whether to reenable DMA -- 3 is a random magic for now, 79 * if we DMA timeout more than 3 times, just stay in PIO 80 */ 81 if ((drive->dev_flags & IDE_DFLAG_DMA_PIO_RETRY) && 82 drive->retry_pio <= 3) { 83 drive->dev_flags &= ~IDE_DFLAG_DMA_PIO_RETRY; 84 ide_dma_on(drive); 85 } 86 87 if (!blk_end_request(rq, error, nr_bytes)) 88 ret = 0; 89 90 if (ret == 0 && dequeue) 91 drive->hwif->rq = NULL; 92 93 return ret; 94} 95 96/** 97 * ide_end_request - complete an IDE I/O 98 * @drive: IDE device for the I/O 99 * @uptodate: 100 * @nr_sectors: number of sectors completed 101 * 102 * This is our end_request wrapper function. We complete the I/O 103 * update random number input and dequeue the request, which if 104 * it was tagged may be out of order. 105 */ 106 107int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors) 108{ 109 unsigned int nr_bytes = nr_sectors << 9; 110 struct request *rq = drive->hwif->rq; 111 112 if (!nr_bytes) { 113 if (blk_pc_request(rq)) 114 nr_bytes = rq->data_len; 115 else 116 nr_bytes = rq->hard_cur_sectors << 9; 117 } 118 119 return __ide_end_request(drive, rq, uptodate, nr_bytes, 1); 120} 121EXPORT_SYMBOL(ide_end_request); 122 123/** 124 * ide_end_dequeued_request - complete an IDE I/O 125 * @drive: IDE device for the I/O 126 * @uptodate: 127 * @nr_sectors: number of sectors completed 128 * 129 * Complete an I/O that is no longer on the request queue. This 130 * typically occurs when we pull the request and issue a REQUEST_SENSE. 131 * We must still finish the old request but we must not tamper with the 132 * queue in the meantime. 133 * 134 * NOTE: This path does not handle barrier, but barrier is not supported 135 * on ide-cd anyway. 136 */ 137 138int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq, 139 int uptodate, int nr_sectors) 140{ 141 BUG_ON(!blk_rq_started(rq)); 142 143 return __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0); 144} 145EXPORT_SYMBOL_GPL(ide_end_dequeued_request); 146 147void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err) 148{ 149 struct ide_taskfile *tf = &cmd->tf; 150 struct request *rq = cmd->rq; 151 152 tf->error = err; 153 tf->status = stat; 154 155 drive->hwif->tp_ops->tf_read(drive, cmd); 156 157 if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE) 158 memcpy(rq->special, cmd, sizeof(*cmd)); 159 160 if (cmd->tf_flags & IDE_TFLAG_DYN) 161 kfree(cmd); 162} 163 164void ide_complete_rq(ide_drive_t *drive, u8 err) 165{ 166 ide_hwif_t *hwif = drive->hwif; 167 struct request *rq = hwif->rq; 168 169 hwif->rq = NULL; 170 171 rq->errors = err; 172 173 if (unlikely(blk_end_request(rq, (rq->errors ? -EIO : 0), 174 blk_rq_bytes(rq)))) 175 BUG(); 176} 177EXPORT_SYMBOL(ide_complete_rq); 178 179void ide_kill_rq(ide_drive_t *drive, struct request *rq) 180{ 181 u8 drv_req = blk_special_request(rq) && rq->rq_disk; 182 u8 media = drive->media; 183 184 drive->failed_pc = NULL; 185 186 if ((media == ide_floppy && drv_req) || media == ide_tape) 187 rq->errors = IDE_DRV_ERROR_GENERAL; 188 189 if ((media == ide_floppy || media == ide_tape) && drv_req) 190 ide_complete_rq(drive, 0); 191 else 192 ide_end_request(drive, 0, 0); 193} 194 195static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf) 196{ 197 tf->nsect = drive->sect; 198 tf->lbal = drive->sect; 199 tf->lbam = drive->cyl; 200 tf->lbah = drive->cyl >> 8; 201 tf->device = (drive->head - 1) | drive->select; 202 tf->command = ATA_CMD_INIT_DEV_PARAMS; 203} 204 205static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf) 206{ 207 tf->nsect = drive->sect; 208 tf->command = ATA_CMD_RESTORE; 209} 210 211static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf) 212{ 213 tf->nsect = drive->mult_req; 214 tf->command = ATA_CMD_SET_MULTI; 215} 216 217static ide_startstop_t ide_disk_special(ide_drive_t *drive) 218{ 219 special_t *s = &drive->special; 220 struct ide_cmd cmd; 221 222 memset(&cmd, 0, sizeof(cmd)); 223 cmd.data_phase = TASKFILE_NO_DATA; 224 225 if (s->b.set_geometry) { 226 s->b.set_geometry = 0; 227 ide_tf_set_specify_cmd(drive, &cmd.tf); 228 } else if (s->b.recalibrate) { 229 s->b.recalibrate = 0; 230 ide_tf_set_restore_cmd(drive, &cmd.tf); 231 } else if (s->b.set_multmode) { 232 s->b.set_multmode = 0; 233 ide_tf_set_setmult_cmd(drive, &cmd.tf); 234 } else if (s->all) { 235 int special = s->all; 236 s->all = 0; 237 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special); 238 return ide_stopped; 239 } 240 241 cmd.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE | 242 IDE_TFLAG_CUSTOM_HANDLER; 243 244 do_rw_taskfile(drive, &cmd); 245 246 return ide_started; 247} 248 249/** 250 * do_special - issue some special commands 251 * @drive: drive the command is for 252 * 253 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS, 254 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive. 255 * 256 * It used to do much more, but has been scaled back. 257 */ 258 259static ide_startstop_t do_special (ide_drive_t *drive) 260{ 261 special_t *s = &drive->special; 262 263#ifdef DEBUG 264 printk("%s: do_special: 0x%02x\n", drive->name, s->all); 265#endif 266 if (drive->media == ide_disk) 267 return ide_disk_special(drive); 268 269 s->all = 0; 270 drive->mult_req = 0; 271 return ide_stopped; 272} 273 274void ide_map_sg(ide_drive_t *drive, struct request *rq) 275{ 276 ide_hwif_t *hwif = drive->hwif; 277 struct scatterlist *sg = hwif->sg_table; 278 279 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) { 280 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE); 281 hwif->sg_nents = 1; 282 } else if (!rq->bio) { 283 sg_init_one(sg, rq->data, rq->data_len); 284 hwif->sg_nents = 1; 285 } else { 286 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg); 287 } 288} 289 290EXPORT_SYMBOL_GPL(ide_map_sg); 291 292void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq) 293{ 294 ide_hwif_t *hwif = drive->hwif; 295 296 hwif->nsect = hwif->nleft = rq->nr_sectors; 297 hwif->cursg_ofs = 0; 298 hwif->cursg = NULL; 299} 300 301EXPORT_SYMBOL_GPL(ide_init_sg_cmd); 302 303/** 304 * execute_drive_command - issue special drive command 305 * @drive: the drive to issue the command on 306 * @rq: the request structure holding the command 307 * 308 * execute_drive_cmd() issues a special drive command, usually 309 * initiated by ioctl() from the external hdparm program. The 310 * command can be a drive command, drive task or taskfile 311 * operation. Weirdly you can call it with NULL to wait for 312 * all commands to finish. Don't do this as that is due to change 313 */ 314 315static ide_startstop_t execute_drive_cmd (ide_drive_t *drive, 316 struct request *rq) 317{ 318 struct ide_cmd *cmd = rq->special; 319 320 if (cmd) { 321 switch (cmd->data_phase) { 322 case TASKFILE_MULTI_OUT: 323 case TASKFILE_OUT: 324 case TASKFILE_MULTI_IN: 325 case TASKFILE_IN: 326 ide_init_sg_cmd(drive, rq); 327 ide_map_sg(drive, rq); 328 default: 329 break; 330 } 331 332 return do_rw_taskfile(drive, cmd); 333 } 334 335 /* 336 * NULL is actually a valid way of waiting for 337 * all current requests to be flushed from the queue. 338 */ 339#ifdef DEBUG 340 printk("%s: DRIVE_CMD (null)\n", drive->name); 341#endif 342 ide_complete_rq(drive, 0); 343 344 return ide_stopped; 345} 346 347static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq) 348{ 349 u8 cmd = rq->cmd[0]; 350 351 switch (cmd) { 352 case REQ_PARK_HEADS: 353 case REQ_UNPARK_HEADS: 354 return ide_do_park_unpark(drive, rq); 355 case REQ_DEVSET_EXEC: 356 return ide_do_devset(drive, rq); 357 case REQ_DRIVE_RESET: 358 return ide_do_reset(drive); 359 default: 360 blk_dump_rq_flags(rq, "ide_special_rq - bad request"); 361 ide_end_request(drive, 0, 0); 362 return ide_stopped; 363 } 364} 365 366/** 367 * start_request - start of I/O and command issuing for IDE 368 * 369 * start_request() initiates handling of a new I/O request. It 370 * accepts commands and I/O (read/write) requests. 371 * 372 * FIXME: this function needs a rename 373 */ 374 375static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq) 376{ 377 ide_startstop_t startstop; 378 379 BUG_ON(!blk_rq_started(rq)); 380 381#ifdef DEBUG 382 printk("%s: start_request: current=0x%08lx\n", 383 drive->hwif->name, (unsigned long) rq); 384#endif 385 386 /* bail early if we've exceeded max_failures */ 387 if (drive->max_failures && (drive->failures > drive->max_failures)) { 388 rq->cmd_flags |= REQ_FAILED; 389 goto kill_rq; 390 } 391 392 if (blk_pm_request(rq)) 393 ide_check_pm_state(drive, rq); 394 395 SELECT_DRIVE(drive); 396 if (ide_wait_stat(&startstop, drive, drive->ready_stat, 397 ATA_BUSY | ATA_DRQ, WAIT_READY)) { 398 printk(KERN_ERR "%s: drive not ready for command\n", drive->name); 399 return startstop; 400 } 401 if (!drive->special.all) { 402 struct ide_driver *drv; 403 404 /* 405 * We reset the drive so we need to issue a SETFEATURES. 406 * Do it _after_ do_special() restored device parameters. 407 */ 408 if (drive->current_speed == 0xff) 409 ide_config_drive_speed(drive, drive->desired_speed); 410 411 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) 412 return execute_drive_cmd(drive, rq); 413 else if (blk_pm_request(rq)) { 414 struct request_pm_state *pm = rq->data; 415#ifdef DEBUG_PM 416 printk("%s: start_power_step(step: %d)\n", 417 drive->name, pm->pm_step); 418#endif 419 startstop = ide_start_power_step(drive, rq); 420 if (startstop == ide_stopped && 421 pm->pm_step == IDE_PM_COMPLETED) 422 ide_complete_pm_rq(drive, rq); 423 return startstop; 424 } else if (!rq->rq_disk && blk_special_request(rq)) 425 /* 426 * TODO: Once all ULDs have been modified to 427 * check for specific op codes rather than 428 * blindly accepting any special request, the 429 * check for ->rq_disk above may be replaced 430 * by a more suitable mechanism or even 431 * dropped entirely. 432 */ 433 return ide_special_rq(drive, rq); 434 435 drv = *(struct ide_driver **)rq->rq_disk->private_data; 436 437 return drv->do_request(drive, rq, rq->sector); 438 } 439 return do_special(drive); 440kill_rq: 441 ide_kill_rq(drive, rq); 442 return ide_stopped; 443} 444 445/** 446 * ide_stall_queue - pause an IDE device 447 * @drive: drive to stall 448 * @timeout: time to stall for (jiffies) 449 * 450 * ide_stall_queue() can be used by a drive to give excess bandwidth back 451 * to the port by sleeping for timeout jiffies. 452 */ 453 454void ide_stall_queue (ide_drive_t *drive, unsigned long timeout) 455{ 456 if (timeout > WAIT_WORSTCASE) 457 timeout = WAIT_WORSTCASE; 458 drive->sleep = timeout + jiffies; 459 drive->dev_flags |= IDE_DFLAG_SLEEPING; 460} 461EXPORT_SYMBOL(ide_stall_queue); 462 463static inline int ide_lock_port(ide_hwif_t *hwif) 464{ 465 if (hwif->busy) 466 return 1; 467 468 hwif->busy = 1; 469 470 return 0; 471} 472 473static inline void ide_unlock_port(ide_hwif_t *hwif) 474{ 475 hwif->busy = 0; 476} 477 478static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif) 479{ 480 int rc = 0; 481 482 if (host->host_flags & IDE_HFLAG_SERIALIZE) { 483 rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy); 484 if (rc == 0) { 485 if (host->get_lock) 486 host->get_lock(ide_intr, hwif); 487 } 488 } 489 return rc; 490} 491 492static inline void ide_unlock_host(struct ide_host *host) 493{ 494 if (host->host_flags & IDE_HFLAG_SERIALIZE) { 495 if (host->release_lock) 496 host->release_lock(); 497 clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy); 498 } 499} 500 501/* 502 * Issue a new request to a device. 503 */ 504void do_ide_request(struct request_queue *q) 505{ 506 ide_drive_t *drive = q->queuedata; 507 ide_hwif_t *hwif = drive->hwif; 508 struct ide_host *host = hwif->host; 509 struct request *rq = NULL; 510 ide_startstop_t startstop; 511 512 /* 513 * drive is doing pre-flush, ordered write, post-flush sequence. even 514 * though that is 3 requests, it must be seen as a single transaction. 515 * we must not preempt this drive until that is complete 516 */ 517 if (blk_queue_flushing(q)) 518 /* 519 * small race where queue could get replugged during 520 * the 3-request flush cycle, just yank the plug since 521 * we want it to finish asap 522 */ 523 blk_remove_plug(q); 524 525 spin_unlock_irq(q->queue_lock); 526 527 if (ide_lock_host(host, hwif)) 528 goto plug_device_2; 529 530 spin_lock_irq(&hwif->lock); 531 532 if (!ide_lock_port(hwif)) { 533 ide_hwif_t *prev_port; 534repeat: 535 prev_port = hwif->host->cur_port; 536 hwif->rq = NULL; 537 538 if (drive->dev_flags & IDE_DFLAG_SLEEPING) { 539 if (time_before(drive->sleep, jiffies)) { 540 ide_unlock_port(hwif); 541 goto plug_device; 542 } 543 } 544 545 if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) && 546 hwif != prev_port) { 547 /* 548 * set nIEN for previous port, drives in the 549 * quirk_list may not like intr setups/cleanups 550 */ 551 if (prev_port && prev_port->cur_dev->quirk_list == 0) 552 prev_port->tp_ops->set_irq(prev_port, 0); 553 554 hwif->host->cur_port = hwif; 555 } 556 hwif->cur_dev = drive; 557 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED); 558 559 spin_unlock_irq(&hwif->lock); 560 spin_lock_irq(q->queue_lock); 561 /* 562 * we know that the queue isn't empty, but this can happen 563 * if the q->prep_rq_fn() decides to kill a request 564 */ 565 rq = elv_next_request(drive->queue); 566 spin_unlock_irq(q->queue_lock); 567 spin_lock_irq(&hwif->lock); 568 569 if (!rq) { 570 ide_unlock_port(hwif); 571 goto out; 572 } 573 574 /* 575 * Sanity: don't accept a request that isn't a PM request 576 * if we are currently power managed. This is very important as 577 * blk_stop_queue() doesn't prevent the elv_next_request() 578 * above to return us whatever is in the queue. Since we call 579 * ide_do_request() ourselves, we end up taking requests while 580 * the queue is blocked... 581 * 582 * We let requests forced at head of queue with ide-preempt 583 * though. I hope that doesn't happen too much, hopefully not 584 * unless the subdriver triggers such a thing in its own PM 585 * state machine. 586 */ 587 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) && 588 blk_pm_request(rq) == 0 && 589 (rq->cmd_flags & REQ_PREEMPT) == 0) { 590 /* there should be no pending command at this point */ 591 ide_unlock_port(hwif); 592 goto plug_device; 593 } 594 595 hwif->rq = rq; 596 597 spin_unlock_irq(&hwif->lock); 598 startstop = start_request(drive, rq); 599 spin_lock_irq(&hwif->lock); 600 601 if (startstop == ide_stopped) 602 goto repeat; 603 } else 604 goto plug_device; 605out: 606 spin_unlock_irq(&hwif->lock); 607 if (rq == NULL) 608 ide_unlock_host(host); 609 spin_lock_irq(q->queue_lock); 610 return; 611 612plug_device: 613 spin_unlock_irq(&hwif->lock); 614 ide_unlock_host(host); 615plug_device_2: 616 spin_lock_irq(q->queue_lock); 617 618 if (!elv_queue_empty(q)) 619 blk_plug_device(q); 620} 621 622static void ide_plug_device(ide_drive_t *drive) 623{ 624 struct request_queue *q = drive->queue; 625 unsigned long flags; 626 627 spin_lock_irqsave(q->queue_lock, flags); 628 if (!elv_queue_empty(q)) 629 blk_plug_device(q); 630 spin_unlock_irqrestore(q->queue_lock, flags); 631} 632 633static int drive_is_ready(ide_drive_t *drive) 634{ 635 ide_hwif_t *hwif = drive->hwif; 636 u8 stat = 0; 637 638 if (drive->waiting_for_dma) 639 return hwif->dma_ops->dma_test_irq(drive); 640 641 if (hwif->io_ports.ctl_addr && 642 (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0) 643 stat = hwif->tp_ops->read_altstatus(hwif); 644 else 645 /* Note: this may clear a pending IRQ!! */ 646 stat = hwif->tp_ops->read_status(hwif); 647 648 if (stat & ATA_BUSY) 649 /* drive busy: definitely not interrupting */ 650 return 0; 651 652 /* drive ready: *might* be interrupting */ 653 return 1; 654} 655 656/** 657 * ide_timer_expiry - handle lack of an IDE interrupt 658 * @data: timer callback magic (hwif) 659 * 660 * An IDE command has timed out before the expected drive return 661 * occurred. At this point we attempt to clean up the current 662 * mess. If the current handler includes an expiry handler then 663 * we invoke the expiry handler, and providing it is happy the 664 * work is done. If that fails we apply generic recovery rules 665 * invoking the handler and checking the drive DMA status. We 666 * have an excessively incestuous relationship with the DMA 667 * logic that wants cleaning up. 668 */ 669 670void ide_timer_expiry (unsigned long data) 671{ 672 ide_hwif_t *hwif = (ide_hwif_t *)data; 673 ide_drive_t *uninitialized_var(drive); 674 ide_handler_t *handler; 675 unsigned long flags; 676 int wait = -1; 677 int plug_device = 0; 678 679 spin_lock_irqsave(&hwif->lock, flags); 680 681 handler = hwif->handler; 682 683 if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) { 684 /* 685 * Either a marginal timeout occurred 686 * (got the interrupt just as timer expired), 687 * or we were "sleeping" to give other devices a chance. 688 * Either way, we don't really want to complain about anything. 689 */ 690 } else { 691 ide_expiry_t *expiry = hwif->expiry; 692 ide_startstop_t startstop = ide_stopped; 693 694 drive = hwif->cur_dev; 695 696 if (expiry) { 697 wait = expiry(drive); 698 if (wait > 0) { /* continue */ 699 /* reset timer */ 700 hwif->timer.expires = jiffies + wait; 701 hwif->req_gen_timer = hwif->req_gen; 702 add_timer(&hwif->timer); 703 spin_unlock_irqrestore(&hwif->lock, flags); 704 return; 705 } 706 } 707 hwif->handler = NULL; 708 /* 709 * We need to simulate a real interrupt when invoking 710 * the handler() function, which means we need to 711 * globally mask the specific IRQ: 712 */ 713 spin_unlock(&hwif->lock); 714 /* disable_irq_nosync ?? */ 715 disable_irq(hwif->irq); 716 /* local CPU only, as if we were handling an interrupt */ 717 local_irq_disable(); 718 if (hwif->polling) { 719 startstop = handler(drive); 720 } else if (drive_is_ready(drive)) { 721 if (drive->waiting_for_dma) 722 hwif->dma_ops->dma_lost_irq(drive); 723 if (hwif->ack_intr) 724 hwif->ack_intr(hwif); 725 printk(KERN_WARNING "%s: lost interrupt\n", 726 drive->name); 727 startstop = handler(drive); 728 } else { 729 if (drive->waiting_for_dma) 730 startstop = ide_dma_timeout_retry(drive, wait); 731 else 732 startstop = ide_error(drive, "irq timeout", 733 hwif->tp_ops->read_status(hwif)); 734 } 735 spin_lock_irq(&hwif->lock); 736 enable_irq(hwif->irq); 737 if (startstop == ide_stopped) { 738 ide_unlock_port(hwif); 739 plug_device = 1; 740 } 741 } 742 spin_unlock_irqrestore(&hwif->lock, flags); 743 744 if (plug_device) { 745 ide_unlock_host(hwif->host); 746 ide_plug_device(drive); 747 } 748} 749 750/** 751 * unexpected_intr - handle an unexpected IDE interrupt 752 * @irq: interrupt line 753 * @hwif: port being processed 754 * 755 * There's nothing really useful we can do with an unexpected interrupt, 756 * other than reading the status register (to clear it), and logging it. 757 * There should be no way that an irq can happen before we're ready for it, 758 * so we needn't worry much about losing an "important" interrupt here. 759 * 760 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever 761 * the drive enters "idle", "standby", or "sleep" mode, so if the status 762 * looks "good", we just ignore the interrupt completely. 763 * 764 * This routine assumes __cli() is in effect when called. 765 * 766 * If an unexpected interrupt happens on irq15 while we are handling irq14 767 * and if the two interfaces are "serialized" (CMD640), then it looks like 768 * we could screw up by interfering with a new request being set up for 769 * irq15. 770 * 771 * In reality, this is a non-issue. The new command is not sent unless 772 * the drive is ready to accept one, in which case we know the drive is 773 * not trying to interrupt us. And ide_set_handler() is always invoked 774 * before completing the issuance of any new drive command, so we will not 775 * be accidentally invoked as a result of any valid command completion 776 * interrupt. 777 */ 778 779static void unexpected_intr(int irq, ide_hwif_t *hwif) 780{ 781 u8 stat = hwif->tp_ops->read_status(hwif); 782 783 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) { 784 /* Try to not flood the console with msgs */ 785 static unsigned long last_msgtime, count; 786 ++count; 787 788 if (time_after(jiffies, last_msgtime + HZ)) { 789 last_msgtime = jiffies; 790 printk(KERN_ERR "%s: unexpected interrupt, " 791 "status=0x%02x, count=%ld\n", 792 hwif->name, stat, count); 793 } 794 } 795} 796 797/** 798 * ide_intr - default IDE interrupt handler 799 * @irq: interrupt number 800 * @dev_id: hwif 801 * @regs: unused weirdness from the kernel irq layer 802 * 803 * This is the default IRQ handler for the IDE layer. You should 804 * not need to override it. If you do be aware it is subtle in 805 * places 806 * 807 * hwif is the interface in the group currently performing 808 * a command. hwif->cur_dev is the drive and hwif->handler is 809 * the IRQ handler to call. As we issue a command the handlers 810 * step through multiple states, reassigning the handler to the 811 * next step in the process. Unlike a smart SCSI controller IDE 812 * expects the main processor to sequence the various transfer 813 * stages. We also manage a poll timer to catch up with most 814 * timeout situations. There are still a few where the handlers 815 * don't ever decide to give up. 816 * 817 * The handler eventually returns ide_stopped to indicate the 818 * request completed. At this point we issue the next request 819 * on the port and the process begins again. 820 */ 821 822irqreturn_t ide_intr (int irq, void *dev_id) 823{ 824 ide_hwif_t *hwif = (ide_hwif_t *)dev_id; 825 struct ide_host *host = hwif->host; 826 ide_drive_t *uninitialized_var(drive); 827 ide_handler_t *handler; 828 unsigned long flags; 829 ide_startstop_t startstop; 830 irqreturn_t irq_ret = IRQ_NONE; 831 int plug_device = 0; 832 833 if (host->host_flags & IDE_HFLAG_SERIALIZE) { 834 if (hwif != host->cur_port) 835 goto out_early; 836 } 837 838 spin_lock_irqsave(&hwif->lock, flags); 839 840 if (hwif->ack_intr && hwif->ack_intr(hwif) == 0) 841 goto out; 842 843 handler = hwif->handler; 844 845 if (handler == NULL || hwif->polling) { 846 /* 847 * Not expecting an interrupt from this drive. 848 * That means this could be: 849 * (1) an interrupt from another PCI device 850 * sharing the same PCI INT# as us. 851 * or (2) a drive just entered sleep or standby mode, 852 * and is interrupting to let us know. 853 * or (3) a spurious interrupt of unknown origin. 854 * 855 * For PCI, we cannot tell the difference, 856 * so in that case we just ignore it and hope it goes away. 857 */ 858 if ((host->irq_flags & IRQF_SHARED) == 0) { 859 /* 860 * Probably not a shared PCI interrupt, 861 * so we can safely try to do something about it: 862 */ 863 unexpected_intr(irq, hwif); 864 } else { 865 /* 866 * Whack the status register, just in case 867 * we have a leftover pending IRQ. 868 */ 869 (void)hwif->tp_ops->read_status(hwif); 870 } 871 goto out; 872 } 873 874 drive = hwif->cur_dev; 875 876 if (!drive_is_ready(drive)) 877 /* 878 * This happens regularly when we share a PCI IRQ with 879 * another device. Unfortunately, it can also happen 880 * with some buggy drives that trigger the IRQ before 881 * their status register is up to date. Hopefully we have 882 * enough advance overhead that the latter isn't a problem. 883 */ 884 goto out; 885 886 hwif->handler = NULL; 887 hwif->req_gen++; 888 del_timer(&hwif->timer); 889 spin_unlock(&hwif->lock); 890 891 if (hwif->port_ops && hwif->port_ops->clear_irq) 892 hwif->port_ops->clear_irq(drive); 893 894 if (drive->dev_flags & IDE_DFLAG_UNMASK) 895 local_irq_enable_in_hardirq(); 896 897 /* service this interrupt, may set handler for next interrupt */ 898 startstop = handler(drive); 899 900 spin_lock_irq(&hwif->lock); 901 /* 902 * Note that handler() may have set things up for another 903 * interrupt to occur soon, but it cannot happen until 904 * we exit from this routine, because it will be the 905 * same irq as is currently being serviced here, and Linux 906 * won't allow another of the same (on any CPU) until we return. 907 */ 908 if (startstop == ide_stopped) { 909 BUG_ON(hwif->handler); 910 ide_unlock_port(hwif); 911 plug_device = 1; 912 } 913 irq_ret = IRQ_HANDLED; 914out: 915 spin_unlock_irqrestore(&hwif->lock, flags); 916out_early: 917 if (plug_device) { 918 ide_unlock_host(hwif->host); 919 ide_plug_device(drive); 920 } 921 922 return irq_ret; 923} 924EXPORT_SYMBOL_GPL(ide_intr); 925 926void ide_pad_transfer(ide_drive_t *drive, int write, int len) 927{ 928 ide_hwif_t *hwif = drive->hwif; 929 u8 buf[4] = { 0 }; 930 931 while (len > 0) { 932 if (write) 933 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len)); 934 else 935 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len)); 936 len -= 4; 937 } 938} 939EXPORT_SYMBOL_GPL(ide_pad_transfer); 940