ide-io.c revision 745483f10c6cefb303007c6873e2bfce54efa8ed
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/completion.h> 44#include <linux/reboot.h> 45#include <linux/cdrom.h> 46#include <linux/seq_file.h> 47#include <linux/device.h> 48#include <linux/kmod.h> 49#include <linux/scatterlist.h> 50#include <linux/bitops.h> 51 52#include <asm/byteorder.h> 53#include <asm/irq.h> 54#include <asm/uaccess.h> 55#include <asm/io.h> 56 57int ide_end_rq(ide_drive_t *drive, struct request *rq, int error, 58 unsigned int nr_bytes) 59{ 60 /* 61 * decide whether to reenable DMA -- 3 is a random magic for now, 62 * if we DMA timeout more than 3 times, just stay in PIO 63 */ 64 if ((drive->dev_flags & IDE_DFLAG_DMA_PIO_RETRY) && 65 drive->retry_pio <= 3) { 66 drive->dev_flags &= ~IDE_DFLAG_DMA_PIO_RETRY; 67 ide_dma_on(drive); 68 } 69 70 return blk_end_request(rq, error, nr_bytes); 71} 72EXPORT_SYMBOL_GPL(ide_end_rq); 73 74void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err) 75{ 76 const struct ide_tp_ops *tp_ops = drive->hwif->tp_ops; 77 struct ide_taskfile *tf = &cmd->tf; 78 struct request *rq = cmd->rq; 79 u8 tf_cmd = tf->command; 80 81 tf->error = err; 82 tf->status = stat; 83 84 if (cmd->ftf_flags & IDE_FTFLAG_IN_DATA) { 85 u8 data[2]; 86 87 tp_ops->input_data(drive, cmd, data, 2); 88 89 cmd->tf.data = data[0]; 90 cmd->hob.data = data[1]; 91 } 92 93 tp_ops->tf_read(drive, cmd); 94 95 if ((cmd->tf_flags & IDE_TFLAG_CUSTOM_HANDLER) && 96 tf_cmd == ATA_CMD_IDLEIMMEDIATE) { 97 if (tf->lbal != 0xc4) { 98 printk(KERN_ERR "%s: head unload failed!\n", 99 drive->name); 100 ide_tf_dump(drive->name, cmd); 101 } else 102 drive->dev_flags |= IDE_DFLAG_PARKED; 103 } 104 105 if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE) 106 memcpy(rq->special, cmd, sizeof(*cmd)); 107 108 if (cmd->tf_flags & IDE_TFLAG_DYN) 109 kfree(cmd); 110} 111 112/* obsolete, blk_rq_bytes() should be used instead */ 113unsigned int ide_rq_bytes(struct request *rq) 114{ 115 if (blk_pc_request(rq)) 116 return rq->data_len; 117 else 118 return rq->hard_cur_sectors << 9; 119} 120EXPORT_SYMBOL_GPL(ide_rq_bytes); 121 122int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes) 123{ 124 ide_hwif_t *hwif = drive->hwif; 125 struct request *rq = hwif->rq; 126 int rc; 127 128 /* 129 * if failfast is set on a request, override number of sectors 130 * and complete the whole request right now 131 */ 132 if (blk_noretry_request(rq) && error <= 0) 133 nr_bytes = rq->hard_nr_sectors << 9; 134 135 rc = ide_end_rq(drive, rq, error, nr_bytes); 136 if (rc == 0) 137 hwif->rq = NULL; 138 139 return rc; 140} 141EXPORT_SYMBOL(ide_complete_rq); 142 143void ide_kill_rq(ide_drive_t *drive, struct request *rq) 144{ 145 u8 drv_req = blk_special_request(rq) && rq->rq_disk; 146 u8 media = drive->media; 147 148 drive->failed_pc = NULL; 149 150 if ((media == ide_floppy || media == ide_tape) && drv_req) { 151 rq->errors = 0; 152 ide_complete_rq(drive, 0, blk_rq_bytes(rq)); 153 } else { 154 if (media == ide_tape) 155 rq->errors = IDE_DRV_ERROR_GENERAL; 156 else if (blk_fs_request(rq) == 0 && rq->errors == 0) 157 rq->errors = -EIO; 158 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq)); 159 } 160} 161 162static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf) 163{ 164 tf->nsect = drive->sect; 165 tf->lbal = drive->sect; 166 tf->lbam = drive->cyl; 167 tf->lbah = drive->cyl >> 8; 168 tf->device = (drive->head - 1) | drive->select; 169 tf->command = ATA_CMD_INIT_DEV_PARAMS; 170} 171 172static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf) 173{ 174 tf->nsect = drive->sect; 175 tf->command = ATA_CMD_RESTORE; 176} 177 178static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf) 179{ 180 tf->nsect = drive->mult_req; 181 tf->command = ATA_CMD_SET_MULTI; 182} 183 184static ide_startstop_t ide_disk_special(ide_drive_t *drive) 185{ 186 special_t *s = &drive->special; 187 struct ide_cmd cmd; 188 189 memset(&cmd, 0, sizeof(cmd)); 190 cmd.protocol = ATA_PROT_NODATA; 191 192 if (s->b.set_geometry) { 193 s->b.set_geometry = 0; 194 ide_tf_set_specify_cmd(drive, &cmd.tf); 195 } else if (s->b.recalibrate) { 196 s->b.recalibrate = 0; 197 ide_tf_set_restore_cmd(drive, &cmd.tf); 198 } else if (s->b.set_multmode) { 199 s->b.set_multmode = 0; 200 ide_tf_set_setmult_cmd(drive, &cmd.tf); 201 } else if (s->all) { 202 int special = s->all; 203 s->all = 0; 204 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special); 205 return ide_stopped; 206 } 207 208 cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE; 209 cmd.valid.in.tf = IDE_VALID_IN_TF | IDE_VALID_DEVICE; 210 cmd.tf_flags = IDE_TFLAG_CUSTOM_HANDLER; 211 212 do_rw_taskfile(drive, &cmd); 213 214 return ide_started; 215} 216 217/** 218 * do_special - issue some special commands 219 * @drive: drive the command is for 220 * 221 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS, 222 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive. 223 * 224 * It used to do much more, but has been scaled back. 225 */ 226 227static ide_startstop_t do_special (ide_drive_t *drive) 228{ 229 special_t *s = &drive->special; 230 231#ifdef DEBUG 232 printk("%s: do_special: 0x%02x\n", drive->name, s->all); 233#endif 234 if (drive->media == ide_disk) 235 return ide_disk_special(drive); 236 237 s->all = 0; 238 drive->mult_req = 0; 239 return ide_stopped; 240} 241 242void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd) 243{ 244 ide_hwif_t *hwif = drive->hwif; 245 struct scatterlist *sg = hwif->sg_table; 246 struct request *rq = cmd->rq; 247 248 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) { 249 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE); 250 cmd->sg_nents = 1; 251 } else if (!rq->bio) { 252 sg_init_one(sg, rq->data, rq->data_len); 253 cmd->sg_nents = 1; 254 } else 255 cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg); 256} 257EXPORT_SYMBOL_GPL(ide_map_sg); 258 259void ide_init_sg_cmd(struct ide_cmd *cmd, unsigned int nr_bytes) 260{ 261 cmd->nbytes = cmd->nleft = nr_bytes; 262 cmd->cursg_ofs = 0; 263 cmd->cursg = NULL; 264} 265EXPORT_SYMBOL_GPL(ide_init_sg_cmd); 266 267/** 268 * execute_drive_command - issue special drive command 269 * @drive: the drive to issue the command on 270 * @rq: the request structure holding the command 271 * 272 * execute_drive_cmd() issues a special drive command, usually 273 * initiated by ioctl() from the external hdparm program. The 274 * command can be a drive command, drive task or taskfile 275 * operation. Weirdly you can call it with NULL to wait for 276 * all commands to finish. Don't do this as that is due to change 277 */ 278 279static ide_startstop_t execute_drive_cmd (ide_drive_t *drive, 280 struct request *rq) 281{ 282 struct ide_cmd *cmd = rq->special; 283 284 if (cmd) { 285 if (cmd->protocol == ATA_PROT_PIO) { 286 ide_init_sg_cmd(cmd, rq->nr_sectors << 9); 287 ide_map_sg(drive, cmd); 288 } 289 290 return do_rw_taskfile(drive, cmd); 291 } 292 293 /* 294 * NULL is actually a valid way of waiting for 295 * all current requests to be flushed from the queue. 296 */ 297#ifdef DEBUG 298 printk("%s: DRIVE_CMD (null)\n", drive->name); 299#endif 300 rq->errors = 0; 301 ide_complete_rq(drive, 0, blk_rq_bytes(rq)); 302 303 return ide_stopped; 304} 305 306static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq) 307{ 308 u8 cmd = rq->cmd[0]; 309 310 switch (cmd) { 311 case REQ_PARK_HEADS: 312 case REQ_UNPARK_HEADS: 313 return ide_do_park_unpark(drive, rq); 314 case REQ_DEVSET_EXEC: 315 return ide_do_devset(drive, rq); 316 case REQ_DRIVE_RESET: 317 return ide_do_reset(drive); 318 default: 319 BUG(); 320 } 321} 322 323/** 324 * start_request - start of I/O and command issuing for IDE 325 * 326 * start_request() initiates handling of a new I/O request. It 327 * accepts commands and I/O (read/write) requests. 328 * 329 * FIXME: this function needs a rename 330 */ 331 332static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq) 333{ 334 ide_startstop_t startstop; 335 336 BUG_ON(!blk_rq_started(rq)); 337 338#ifdef DEBUG 339 printk("%s: start_request: current=0x%08lx\n", 340 drive->hwif->name, (unsigned long) rq); 341#endif 342 343 /* bail early if we've exceeded max_failures */ 344 if (drive->max_failures && (drive->failures > drive->max_failures)) { 345 rq->cmd_flags |= REQ_FAILED; 346 goto kill_rq; 347 } 348 349 if (blk_pm_request(rq)) 350 ide_check_pm_state(drive, rq); 351 352 drive->hwif->tp_ops->dev_select(drive); 353 if (ide_wait_stat(&startstop, drive, drive->ready_stat, 354 ATA_BUSY | ATA_DRQ, WAIT_READY)) { 355 printk(KERN_ERR "%s: drive not ready for command\n", drive->name); 356 return startstop; 357 } 358 if (!drive->special.all) { 359 struct ide_driver *drv; 360 361 /* 362 * We reset the drive so we need to issue a SETFEATURES. 363 * Do it _after_ do_special() restored device parameters. 364 */ 365 if (drive->current_speed == 0xff) 366 ide_config_drive_speed(drive, drive->desired_speed); 367 368 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) 369 return execute_drive_cmd(drive, rq); 370 else if (blk_pm_request(rq)) { 371 struct request_pm_state *pm = rq->data; 372#ifdef DEBUG_PM 373 printk("%s: start_power_step(step: %d)\n", 374 drive->name, pm->pm_step); 375#endif 376 startstop = ide_start_power_step(drive, rq); 377 if (startstop == ide_stopped && 378 pm->pm_step == IDE_PM_COMPLETED) 379 ide_complete_pm_rq(drive, rq); 380 return startstop; 381 } else if (!rq->rq_disk && blk_special_request(rq)) 382 /* 383 * TODO: Once all ULDs have been modified to 384 * check for specific op codes rather than 385 * blindly accepting any special request, the 386 * check for ->rq_disk above may be replaced 387 * by a more suitable mechanism or even 388 * dropped entirely. 389 */ 390 return ide_special_rq(drive, rq); 391 392 drv = *(struct ide_driver **)rq->rq_disk->private_data; 393 394 return drv->do_request(drive, rq, rq->sector); 395 } 396 return do_special(drive); 397kill_rq: 398 ide_kill_rq(drive, rq); 399 return ide_stopped; 400} 401 402/** 403 * ide_stall_queue - pause an IDE device 404 * @drive: drive to stall 405 * @timeout: time to stall for (jiffies) 406 * 407 * ide_stall_queue() can be used by a drive to give excess bandwidth back 408 * to the port by sleeping for timeout jiffies. 409 */ 410 411void ide_stall_queue (ide_drive_t *drive, unsigned long timeout) 412{ 413 if (timeout > WAIT_WORSTCASE) 414 timeout = WAIT_WORSTCASE; 415 drive->sleep = timeout + jiffies; 416 drive->dev_flags |= IDE_DFLAG_SLEEPING; 417} 418EXPORT_SYMBOL(ide_stall_queue); 419 420static inline int ide_lock_port(ide_hwif_t *hwif) 421{ 422 if (hwif->busy) 423 return 1; 424 425 hwif->busy = 1; 426 427 return 0; 428} 429 430static inline void ide_unlock_port(ide_hwif_t *hwif) 431{ 432 hwif->busy = 0; 433} 434 435static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif) 436{ 437 int rc = 0; 438 439 if (host->host_flags & IDE_HFLAG_SERIALIZE) { 440 rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy); 441 if (rc == 0) { 442 if (host->get_lock) 443 host->get_lock(ide_intr, hwif); 444 } 445 } 446 return rc; 447} 448 449static inline void ide_unlock_host(struct ide_host *host) 450{ 451 if (host->host_flags & IDE_HFLAG_SERIALIZE) { 452 if (host->release_lock) 453 host->release_lock(); 454 clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy); 455 } 456} 457 458/* 459 * Issue a new request to a device. 460 */ 461void do_ide_request(struct request_queue *q) 462{ 463 ide_drive_t *drive = q->queuedata; 464 ide_hwif_t *hwif = drive->hwif; 465 struct ide_host *host = hwif->host; 466 struct request *rq = NULL; 467 ide_startstop_t startstop; 468 469 /* 470 * drive is doing pre-flush, ordered write, post-flush sequence. even 471 * though that is 3 requests, it must be seen as a single transaction. 472 * we must not preempt this drive until that is complete 473 */ 474 if (blk_queue_flushing(q)) 475 /* 476 * small race where queue could get replugged during 477 * the 3-request flush cycle, just yank the plug since 478 * we want it to finish asap 479 */ 480 blk_remove_plug(q); 481 482 spin_unlock_irq(q->queue_lock); 483 484 if (ide_lock_host(host, hwif)) 485 goto plug_device_2; 486 487 spin_lock_irq(&hwif->lock); 488 489 if (!ide_lock_port(hwif)) { 490 ide_hwif_t *prev_port; 491repeat: 492 prev_port = hwif->host->cur_port; 493 hwif->rq = NULL; 494 495 if (drive->dev_flags & IDE_DFLAG_SLEEPING && 496 time_after(drive->sleep, jiffies)) { 497 ide_unlock_port(hwif); 498 goto plug_device; 499 } 500 501 if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) && 502 hwif != prev_port) { 503 /* 504 * set nIEN for previous port, drives in the 505 * quirk_list may not like intr setups/cleanups 506 */ 507 if (prev_port && prev_port->cur_dev->quirk_list == 0) 508 prev_port->tp_ops->write_devctl(prev_port, 509 ATA_NIEN | 510 ATA_DEVCTL_OBS); 511 512 hwif->host->cur_port = hwif; 513 } 514 hwif->cur_dev = drive; 515 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED); 516 517 spin_unlock_irq(&hwif->lock); 518 spin_lock_irq(q->queue_lock); 519 /* 520 * we know that the queue isn't empty, but this can happen 521 * if the q->prep_rq_fn() decides to kill a request 522 */ 523 rq = elv_next_request(drive->queue); 524 spin_unlock_irq(q->queue_lock); 525 spin_lock_irq(&hwif->lock); 526 527 if (!rq) { 528 ide_unlock_port(hwif); 529 goto out; 530 } 531 532 /* 533 * Sanity: don't accept a request that isn't a PM request 534 * if we are currently power managed. This is very important as 535 * blk_stop_queue() doesn't prevent the elv_next_request() 536 * above to return us whatever is in the queue. Since we call 537 * ide_do_request() ourselves, we end up taking requests while 538 * the queue is blocked... 539 * 540 * We let requests forced at head of queue with ide-preempt 541 * though. I hope that doesn't happen too much, hopefully not 542 * unless the subdriver triggers such a thing in its own PM 543 * state machine. 544 */ 545 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) && 546 blk_pm_request(rq) == 0 && 547 (rq->cmd_flags & REQ_PREEMPT) == 0) { 548 /* there should be no pending command at this point */ 549 ide_unlock_port(hwif); 550 goto plug_device; 551 } 552 553 hwif->rq = rq; 554 555 spin_unlock_irq(&hwif->lock); 556 startstop = start_request(drive, rq); 557 spin_lock_irq(&hwif->lock); 558 559 if (startstop == ide_stopped) 560 goto repeat; 561 } else 562 goto plug_device; 563out: 564 spin_unlock_irq(&hwif->lock); 565 if (rq == NULL) 566 ide_unlock_host(host); 567 spin_lock_irq(q->queue_lock); 568 return; 569 570plug_device: 571 spin_unlock_irq(&hwif->lock); 572 ide_unlock_host(host); 573plug_device_2: 574 spin_lock_irq(q->queue_lock); 575 576 if (!elv_queue_empty(q)) 577 blk_plug_device(q); 578} 579 580static void ide_plug_device(ide_drive_t *drive) 581{ 582 struct request_queue *q = drive->queue; 583 unsigned long flags; 584 585 spin_lock_irqsave(q->queue_lock, flags); 586 if (!elv_queue_empty(q)) 587 blk_plug_device(q); 588 spin_unlock_irqrestore(q->queue_lock, flags); 589} 590 591static int drive_is_ready(ide_drive_t *drive) 592{ 593 ide_hwif_t *hwif = drive->hwif; 594 u8 stat = 0; 595 596 if (drive->waiting_for_dma) 597 return hwif->dma_ops->dma_test_irq(drive); 598 599 if (hwif->io_ports.ctl_addr && 600 (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0) 601 stat = hwif->tp_ops->read_altstatus(hwif); 602 else 603 /* Note: this may clear a pending IRQ!! */ 604 stat = hwif->tp_ops->read_status(hwif); 605 606 if (stat & ATA_BUSY) 607 /* drive busy: definitely not interrupting */ 608 return 0; 609 610 /* drive ready: *might* be interrupting */ 611 return 1; 612} 613 614/** 615 * ide_timer_expiry - handle lack of an IDE interrupt 616 * @data: timer callback magic (hwif) 617 * 618 * An IDE command has timed out before the expected drive return 619 * occurred. At this point we attempt to clean up the current 620 * mess. If the current handler includes an expiry handler then 621 * we invoke the expiry handler, and providing it is happy the 622 * work is done. If that fails we apply generic recovery rules 623 * invoking the handler and checking the drive DMA status. We 624 * have an excessively incestuous relationship with the DMA 625 * logic that wants cleaning up. 626 */ 627 628void ide_timer_expiry (unsigned long data) 629{ 630 ide_hwif_t *hwif = (ide_hwif_t *)data; 631 ide_drive_t *uninitialized_var(drive); 632 ide_handler_t *handler; 633 unsigned long flags; 634 int wait = -1; 635 int plug_device = 0; 636 637 spin_lock_irqsave(&hwif->lock, flags); 638 639 handler = hwif->handler; 640 641 if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) { 642 /* 643 * Either a marginal timeout occurred 644 * (got the interrupt just as timer expired), 645 * or we were "sleeping" to give other devices a chance. 646 * Either way, we don't really want to complain about anything. 647 */ 648 } else { 649 ide_expiry_t *expiry = hwif->expiry; 650 ide_startstop_t startstop = ide_stopped; 651 652 drive = hwif->cur_dev; 653 654 if (expiry) { 655 wait = expiry(drive); 656 if (wait > 0) { /* continue */ 657 /* reset timer */ 658 hwif->timer.expires = jiffies + wait; 659 hwif->req_gen_timer = hwif->req_gen; 660 add_timer(&hwif->timer); 661 spin_unlock_irqrestore(&hwif->lock, flags); 662 return; 663 } 664 } 665 hwif->handler = NULL; 666 hwif->expiry = NULL; 667 /* 668 * We need to simulate a real interrupt when invoking 669 * the handler() function, which means we need to 670 * globally mask the specific IRQ: 671 */ 672 spin_unlock(&hwif->lock); 673 /* disable_irq_nosync ?? */ 674 disable_irq(hwif->irq); 675 /* local CPU only, as if we were handling an interrupt */ 676 local_irq_disable(); 677 if (hwif->polling) { 678 startstop = handler(drive); 679 } else if (drive_is_ready(drive)) { 680 if (drive->waiting_for_dma) 681 hwif->dma_ops->dma_lost_irq(drive); 682 if (hwif->ack_intr) 683 hwif->ack_intr(hwif); 684 printk(KERN_WARNING "%s: lost interrupt\n", 685 drive->name); 686 startstop = handler(drive); 687 } else { 688 if (drive->waiting_for_dma) 689 startstop = ide_dma_timeout_retry(drive, wait); 690 else 691 startstop = ide_error(drive, "irq timeout", 692 hwif->tp_ops->read_status(hwif)); 693 } 694 spin_lock_irq(&hwif->lock); 695 enable_irq(hwif->irq); 696 if (startstop == ide_stopped) { 697 ide_unlock_port(hwif); 698 plug_device = 1; 699 } 700 } 701 spin_unlock_irqrestore(&hwif->lock, flags); 702 703 if (plug_device) { 704 ide_unlock_host(hwif->host); 705 ide_plug_device(drive); 706 } 707} 708 709/** 710 * unexpected_intr - handle an unexpected IDE interrupt 711 * @irq: interrupt line 712 * @hwif: port being processed 713 * 714 * There's nothing really useful we can do with an unexpected interrupt, 715 * other than reading the status register (to clear it), and logging it. 716 * There should be no way that an irq can happen before we're ready for it, 717 * so we needn't worry much about losing an "important" interrupt here. 718 * 719 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever 720 * the drive enters "idle", "standby", or "sleep" mode, so if the status 721 * looks "good", we just ignore the interrupt completely. 722 * 723 * This routine assumes __cli() is in effect when called. 724 * 725 * If an unexpected interrupt happens on irq15 while we are handling irq14 726 * and if the two interfaces are "serialized" (CMD640), then it looks like 727 * we could screw up by interfering with a new request being set up for 728 * irq15. 729 * 730 * In reality, this is a non-issue. The new command is not sent unless 731 * the drive is ready to accept one, in which case we know the drive is 732 * not trying to interrupt us. And ide_set_handler() is always invoked 733 * before completing the issuance of any new drive command, so we will not 734 * be accidentally invoked as a result of any valid command completion 735 * interrupt. 736 */ 737 738static void unexpected_intr(int irq, ide_hwif_t *hwif) 739{ 740 u8 stat = hwif->tp_ops->read_status(hwif); 741 742 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) { 743 /* Try to not flood the console with msgs */ 744 static unsigned long last_msgtime, count; 745 ++count; 746 747 if (time_after(jiffies, last_msgtime + HZ)) { 748 last_msgtime = jiffies; 749 printk(KERN_ERR "%s: unexpected interrupt, " 750 "status=0x%02x, count=%ld\n", 751 hwif->name, stat, count); 752 } 753 } 754} 755 756/** 757 * ide_intr - default IDE interrupt handler 758 * @irq: interrupt number 759 * @dev_id: hwif 760 * @regs: unused weirdness from the kernel irq layer 761 * 762 * This is the default IRQ handler for the IDE layer. You should 763 * not need to override it. If you do be aware it is subtle in 764 * places 765 * 766 * hwif is the interface in the group currently performing 767 * a command. hwif->cur_dev is the drive and hwif->handler is 768 * the IRQ handler to call. As we issue a command the handlers 769 * step through multiple states, reassigning the handler to the 770 * next step in the process. Unlike a smart SCSI controller IDE 771 * expects the main processor to sequence the various transfer 772 * stages. We also manage a poll timer to catch up with most 773 * timeout situations. There are still a few where the handlers 774 * don't ever decide to give up. 775 * 776 * The handler eventually returns ide_stopped to indicate the 777 * request completed. At this point we issue the next request 778 * on the port and the process begins again. 779 */ 780 781irqreturn_t ide_intr (int irq, void *dev_id) 782{ 783 ide_hwif_t *hwif = (ide_hwif_t *)dev_id; 784 struct ide_host *host = hwif->host; 785 ide_drive_t *uninitialized_var(drive); 786 ide_handler_t *handler; 787 unsigned long flags; 788 ide_startstop_t startstop; 789 irqreturn_t irq_ret = IRQ_NONE; 790 int plug_device = 0; 791 792 if (host->host_flags & IDE_HFLAG_SERIALIZE) { 793 if (hwif != host->cur_port) 794 goto out_early; 795 } 796 797 spin_lock_irqsave(&hwif->lock, flags); 798 799 if (hwif->ack_intr && hwif->ack_intr(hwif) == 0) 800 goto out; 801 802 handler = hwif->handler; 803 804 if (handler == NULL || hwif->polling) { 805 /* 806 * Not expecting an interrupt from this drive. 807 * That means this could be: 808 * (1) an interrupt from another PCI device 809 * sharing the same PCI INT# as us. 810 * or (2) a drive just entered sleep or standby mode, 811 * and is interrupting to let us know. 812 * or (3) a spurious interrupt of unknown origin. 813 * 814 * For PCI, we cannot tell the difference, 815 * so in that case we just ignore it and hope it goes away. 816 */ 817 if ((host->irq_flags & IRQF_SHARED) == 0) { 818 /* 819 * Probably not a shared PCI interrupt, 820 * so we can safely try to do something about it: 821 */ 822 unexpected_intr(irq, hwif); 823 } else { 824 /* 825 * Whack the status register, just in case 826 * we have a leftover pending IRQ. 827 */ 828 (void)hwif->tp_ops->read_status(hwif); 829 } 830 goto out; 831 } 832 833 drive = hwif->cur_dev; 834 835 if (!drive_is_ready(drive)) 836 /* 837 * This happens regularly when we share a PCI IRQ with 838 * another device. Unfortunately, it can also happen 839 * with some buggy drives that trigger the IRQ before 840 * their status register is up to date. Hopefully we have 841 * enough advance overhead that the latter isn't a problem. 842 */ 843 goto out; 844 845 hwif->handler = NULL; 846 hwif->expiry = NULL; 847 hwif->req_gen++; 848 del_timer(&hwif->timer); 849 spin_unlock(&hwif->lock); 850 851 if (hwif->port_ops && hwif->port_ops->clear_irq) 852 hwif->port_ops->clear_irq(drive); 853 854 if (drive->dev_flags & IDE_DFLAG_UNMASK) 855 local_irq_enable_in_hardirq(); 856 857 /* service this interrupt, may set handler for next interrupt */ 858 startstop = handler(drive); 859 860 spin_lock_irq(&hwif->lock); 861 /* 862 * Note that handler() may have set things up for another 863 * interrupt to occur soon, but it cannot happen until 864 * we exit from this routine, because it will be the 865 * same irq as is currently being serviced here, and Linux 866 * won't allow another of the same (on any CPU) until we return. 867 */ 868 if (startstop == ide_stopped) { 869 BUG_ON(hwif->handler); 870 ide_unlock_port(hwif); 871 plug_device = 1; 872 } 873 irq_ret = IRQ_HANDLED; 874out: 875 spin_unlock_irqrestore(&hwif->lock, flags); 876out_early: 877 if (plug_device) { 878 ide_unlock_host(hwif->host); 879 ide_plug_device(drive); 880 } 881 882 return irq_ret; 883} 884EXPORT_SYMBOL_GPL(ide_intr); 885 886void ide_pad_transfer(ide_drive_t *drive, int write, int len) 887{ 888 ide_hwif_t *hwif = drive->hwif; 889 u8 buf[4] = { 0 }; 890 891 while (len > 0) { 892 if (write) 893 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len)); 894 else 895 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len)); 896 len -= 4; 897 } 898} 899EXPORT_SYMBOL_GPL(ide_pad_transfer); 900