ide-io.c revision b46f205da647608a4064ce0a0acb07a8c74c6f23
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->hwgroup->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->hwgroup->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); 146 147/** 148 * ide_end_drive_cmd - end an explicit drive command 149 * @drive: command 150 * @stat: status bits 151 * @err: error bits 152 * 153 * Clean up after success/failure of an explicit drive command. 154 * These get thrown onto the queue so they are synchronized with 155 * real I/O operations on the drive. 156 * 157 * In LBA48 mode we have to read the register set twice to get 158 * all the extra information out. 159 */ 160 161void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err) 162{ 163 ide_hwgroup_t *hwgroup = drive->hwif->hwgroup; 164 struct request *rq = hwgroup->rq; 165 166 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) { 167 ide_task_t *task = (ide_task_t *)rq->special; 168 169 if (task) { 170 struct ide_taskfile *tf = &task->tf; 171 172 tf->error = err; 173 tf->status = stat; 174 175 drive->hwif->tp_ops->tf_read(drive, task); 176 177 if (task->tf_flags & IDE_TFLAG_DYN) 178 kfree(task); 179 } 180 } else if (blk_pm_request(rq)) { 181 struct request_pm_state *pm = rq->data; 182 183 ide_complete_power_step(drive, rq); 184 if (pm->pm_step == IDE_PM_COMPLETED) 185 ide_complete_pm_request(drive, rq); 186 return; 187 } 188 189 hwgroup->rq = NULL; 190 191 rq->errors = err; 192 193 if (unlikely(blk_end_request(rq, (rq->errors ? -EIO : 0), 194 blk_rq_bytes(rq)))) 195 BUG(); 196} 197EXPORT_SYMBOL(ide_end_drive_cmd); 198 199static void ide_kill_rq(ide_drive_t *drive, struct request *rq) 200{ 201 if (rq->rq_disk) { 202 ide_driver_t *drv; 203 204 drv = *(ide_driver_t **)rq->rq_disk->private_data; 205 drv->end_request(drive, 0, 0); 206 } else 207 ide_end_request(drive, 0, 0); 208} 209 210static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err) 211{ 212 ide_hwif_t *hwif = drive->hwif; 213 214 if ((stat & ATA_BUSY) || 215 ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) { 216 /* other bits are useless when BUSY */ 217 rq->errors |= ERROR_RESET; 218 } else if (stat & ATA_ERR) { 219 /* err has different meaning on cdrom and tape */ 220 if (err == ATA_ABORTED) { 221 if ((drive->dev_flags & IDE_DFLAG_LBA) && 222 /* some newer drives don't support ATA_CMD_INIT_DEV_PARAMS */ 223 hwif->tp_ops->read_status(hwif) == ATA_CMD_INIT_DEV_PARAMS) 224 return ide_stopped; 225 } else if ((err & BAD_CRC) == BAD_CRC) { 226 /* UDMA crc error, just retry the operation */ 227 drive->crc_count++; 228 } else if (err & (ATA_BBK | ATA_UNC)) { 229 /* retries won't help these */ 230 rq->errors = ERROR_MAX; 231 } else if (err & ATA_TRK0NF) { 232 /* help it find track zero */ 233 rq->errors |= ERROR_RECAL; 234 } 235 } 236 237 if ((stat & ATA_DRQ) && rq_data_dir(rq) == READ && 238 (hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0) { 239 int nsect = drive->mult_count ? drive->mult_count : 1; 240 241 ide_pad_transfer(drive, READ, nsect * SECTOR_SIZE); 242 } 243 244 if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) { 245 ide_kill_rq(drive, rq); 246 return ide_stopped; 247 } 248 249 if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ)) 250 rq->errors |= ERROR_RESET; 251 252 if ((rq->errors & ERROR_RESET) == ERROR_RESET) { 253 ++rq->errors; 254 return ide_do_reset(drive); 255 } 256 257 if ((rq->errors & ERROR_RECAL) == ERROR_RECAL) 258 drive->special.b.recalibrate = 1; 259 260 ++rq->errors; 261 262 return ide_stopped; 263} 264 265static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err) 266{ 267 ide_hwif_t *hwif = drive->hwif; 268 269 if ((stat & ATA_BUSY) || 270 ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) { 271 /* other bits are useless when BUSY */ 272 rq->errors |= ERROR_RESET; 273 } else { 274 /* add decoding error stuff */ 275 } 276 277 if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ)) 278 /* force an abort */ 279 hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE); 280 281 if (rq->errors >= ERROR_MAX) { 282 ide_kill_rq(drive, rq); 283 } else { 284 if ((rq->errors & ERROR_RESET) == ERROR_RESET) { 285 ++rq->errors; 286 return ide_do_reset(drive); 287 } 288 ++rq->errors; 289 } 290 291 return ide_stopped; 292} 293 294ide_startstop_t 295__ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err) 296{ 297 if (drive->media == ide_disk) 298 return ide_ata_error(drive, rq, stat, err); 299 return ide_atapi_error(drive, rq, stat, err); 300} 301 302EXPORT_SYMBOL_GPL(__ide_error); 303 304/** 305 * ide_error - handle an error on the IDE 306 * @drive: drive the error occurred on 307 * @msg: message to report 308 * @stat: status bits 309 * 310 * ide_error() takes action based on the error returned by the drive. 311 * For normal I/O that may well include retries. We deal with 312 * both new-style (taskfile) and old style command handling here. 313 * In the case of taskfile command handling there is work left to 314 * do 315 */ 316 317ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat) 318{ 319 struct request *rq; 320 u8 err; 321 322 err = ide_dump_status(drive, msg, stat); 323 324 if ((rq = HWGROUP(drive)->rq) == NULL) 325 return ide_stopped; 326 327 /* retry only "normal" I/O: */ 328 if (!blk_fs_request(rq)) { 329 rq->errors = 1; 330 ide_end_drive_cmd(drive, stat, err); 331 return ide_stopped; 332 } 333 334 if (rq->rq_disk) { 335 ide_driver_t *drv; 336 337 drv = *(ide_driver_t **)rq->rq_disk->private_data; 338 return drv->error(drive, rq, stat, err); 339 } else 340 return __ide_error(drive, rq, stat, err); 341} 342 343EXPORT_SYMBOL_GPL(ide_error); 344 345static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf) 346{ 347 tf->nsect = drive->sect; 348 tf->lbal = drive->sect; 349 tf->lbam = drive->cyl; 350 tf->lbah = drive->cyl >> 8; 351 tf->device = (drive->head - 1) | drive->select; 352 tf->command = ATA_CMD_INIT_DEV_PARAMS; 353} 354 355static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf) 356{ 357 tf->nsect = drive->sect; 358 tf->command = ATA_CMD_RESTORE; 359} 360 361static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf) 362{ 363 tf->nsect = drive->mult_req; 364 tf->command = ATA_CMD_SET_MULTI; 365} 366 367static ide_startstop_t ide_disk_special(ide_drive_t *drive) 368{ 369 special_t *s = &drive->special; 370 ide_task_t args; 371 372 memset(&args, 0, sizeof(ide_task_t)); 373 args.data_phase = TASKFILE_NO_DATA; 374 375 if (s->b.set_geometry) { 376 s->b.set_geometry = 0; 377 ide_tf_set_specify_cmd(drive, &args.tf); 378 } else if (s->b.recalibrate) { 379 s->b.recalibrate = 0; 380 ide_tf_set_restore_cmd(drive, &args.tf); 381 } else if (s->b.set_multmode) { 382 s->b.set_multmode = 0; 383 ide_tf_set_setmult_cmd(drive, &args.tf); 384 } else if (s->all) { 385 int special = s->all; 386 s->all = 0; 387 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special); 388 return ide_stopped; 389 } 390 391 args.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE | 392 IDE_TFLAG_CUSTOM_HANDLER; 393 394 do_rw_taskfile(drive, &args); 395 396 return ide_started; 397} 398 399/** 400 * do_special - issue some special commands 401 * @drive: drive the command is for 402 * 403 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS, 404 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive. 405 * 406 * It used to do much more, but has been scaled back. 407 */ 408 409static ide_startstop_t do_special (ide_drive_t *drive) 410{ 411 special_t *s = &drive->special; 412 413#ifdef DEBUG 414 printk("%s: do_special: 0x%02x\n", drive->name, s->all); 415#endif 416 if (drive->media == ide_disk) 417 return ide_disk_special(drive); 418 419 s->all = 0; 420 drive->mult_req = 0; 421 return ide_stopped; 422} 423 424void ide_map_sg(ide_drive_t *drive, struct request *rq) 425{ 426 ide_hwif_t *hwif = drive->hwif; 427 struct scatterlist *sg = hwif->sg_table; 428 429 if (rq->cmd_type != REQ_TYPE_ATA_TASKFILE) { 430 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg); 431 } else { 432 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE); 433 hwif->sg_nents = 1; 434 } 435} 436 437EXPORT_SYMBOL_GPL(ide_map_sg); 438 439void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq) 440{ 441 ide_hwif_t *hwif = drive->hwif; 442 443 hwif->nsect = hwif->nleft = rq->nr_sectors; 444 hwif->cursg_ofs = 0; 445 hwif->cursg = NULL; 446} 447 448EXPORT_SYMBOL_GPL(ide_init_sg_cmd); 449 450/** 451 * execute_drive_command - issue special drive command 452 * @drive: the drive to issue the command on 453 * @rq: the request structure holding the command 454 * 455 * execute_drive_cmd() issues a special drive command, usually 456 * initiated by ioctl() from the external hdparm program. The 457 * command can be a drive command, drive task or taskfile 458 * operation. Weirdly you can call it with NULL to wait for 459 * all commands to finish. Don't do this as that is due to change 460 */ 461 462static ide_startstop_t execute_drive_cmd (ide_drive_t *drive, 463 struct request *rq) 464{ 465 ide_hwif_t *hwif = HWIF(drive); 466 ide_task_t *task = rq->special; 467 468 if (task) { 469 hwif->data_phase = task->data_phase; 470 471 switch (hwif->data_phase) { 472 case TASKFILE_MULTI_OUT: 473 case TASKFILE_OUT: 474 case TASKFILE_MULTI_IN: 475 case TASKFILE_IN: 476 ide_init_sg_cmd(drive, rq); 477 ide_map_sg(drive, rq); 478 default: 479 break; 480 } 481 482 return do_rw_taskfile(drive, task); 483 } 484 485 /* 486 * NULL is actually a valid way of waiting for 487 * all current requests to be flushed from the queue. 488 */ 489#ifdef DEBUG 490 printk("%s: DRIVE_CMD (null)\n", drive->name); 491#endif 492 ide_end_drive_cmd(drive, hwif->tp_ops->read_status(hwif), 493 ide_read_error(drive)); 494 495 return ide_stopped; 496} 497 498int ide_devset_execute(ide_drive_t *drive, const struct ide_devset *setting, 499 int arg) 500{ 501 struct request_queue *q = drive->queue; 502 struct request *rq; 503 int ret = 0; 504 505 if (!(setting->flags & DS_SYNC)) 506 return setting->set(drive, arg); 507 508 rq = blk_get_request(q, READ, __GFP_WAIT); 509 rq->cmd_type = REQ_TYPE_SPECIAL; 510 rq->cmd_len = 5; 511 rq->cmd[0] = REQ_DEVSET_EXEC; 512 *(int *)&rq->cmd[1] = arg; 513 rq->special = setting->set; 514 515 if (blk_execute_rq(q, NULL, rq, 0)) 516 ret = rq->errors; 517 blk_put_request(rq); 518 519 return ret; 520} 521EXPORT_SYMBOL_GPL(ide_devset_execute); 522 523static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq) 524{ 525 u8 cmd = rq->cmd[0]; 526 527 if (cmd == REQ_PARK_HEADS || cmd == REQ_UNPARK_HEADS) { 528 ide_task_t task; 529 struct ide_taskfile *tf = &task.tf; 530 531 memset(&task, 0, sizeof(task)); 532 if (cmd == REQ_PARK_HEADS) { 533 drive->sleep = *(unsigned long *)rq->special; 534 drive->dev_flags |= IDE_DFLAG_SLEEPING; 535 tf->command = ATA_CMD_IDLEIMMEDIATE; 536 tf->feature = 0x44; 537 tf->lbal = 0x4c; 538 tf->lbam = 0x4e; 539 tf->lbah = 0x55; 540 task.tf_flags |= IDE_TFLAG_CUSTOM_HANDLER; 541 } else /* cmd == REQ_UNPARK_HEADS */ 542 tf->command = ATA_CMD_CHK_POWER; 543 544 task.tf_flags |= IDE_TFLAG_TF | IDE_TFLAG_DEVICE; 545 task.rq = rq; 546 drive->hwif->data_phase = task.data_phase = TASKFILE_NO_DATA; 547 return do_rw_taskfile(drive, &task); 548 } 549 550 switch (cmd) { 551 case REQ_DEVSET_EXEC: 552 { 553 int err, (*setfunc)(ide_drive_t *, int) = rq->special; 554 555 err = setfunc(drive, *(int *)&rq->cmd[1]); 556 if (err) 557 rq->errors = err; 558 else 559 err = 1; 560 ide_end_request(drive, err, 0); 561 return ide_stopped; 562 } 563 case REQ_DRIVE_RESET: 564 return ide_do_reset(drive); 565 default: 566 blk_dump_rq_flags(rq, "ide_special_rq - bad request"); 567 ide_end_request(drive, 0, 0); 568 return ide_stopped; 569 } 570} 571 572/** 573 * start_request - start of I/O and command issuing for IDE 574 * 575 * start_request() initiates handling of a new I/O request. It 576 * accepts commands and I/O (read/write) requests. 577 * 578 * FIXME: this function needs a rename 579 */ 580 581static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq) 582{ 583 ide_startstop_t startstop; 584 585 BUG_ON(!blk_rq_started(rq)); 586 587#ifdef DEBUG 588 printk("%s: start_request: current=0x%08lx\n", 589 HWIF(drive)->name, (unsigned long) rq); 590#endif 591 592 /* bail early if we've exceeded max_failures */ 593 if (drive->max_failures && (drive->failures > drive->max_failures)) { 594 rq->cmd_flags |= REQ_FAILED; 595 goto kill_rq; 596 } 597 598 if (blk_pm_request(rq)) 599 ide_check_pm_state(drive, rq); 600 601 SELECT_DRIVE(drive); 602 if (ide_wait_stat(&startstop, drive, drive->ready_stat, 603 ATA_BUSY | ATA_DRQ, WAIT_READY)) { 604 printk(KERN_ERR "%s: drive not ready for command\n", drive->name); 605 return startstop; 606 } 607 if (!drive->special.all) { 608 ide_driver_t *drv; 609 610 /* 611 * We reset the drive so we need to issue a SETFEATURES. 612 * Do it _after_ do_special() restored device parameters. 613 */ 614 if (drive->current_speed == 0xff) 615 ide_config_drive_speed(drive, drive->desired_speed); 616 617 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) 618 return execute_drive_cmd(drive, rq); 619 else if (blk_pm_request(rq)) { 620 struct request_pm_state *pm = rq->data; 621#ifdef DEBUG_PM 622 printk("%s: start_power_step(step: %d)\n", 623 drive->name, pm->pm_step); 624#endif 625 startstop = ide_start_power_step(drive, rq); 626 if (startstop == ide_stopped && 627 pm->pm_step == IDE_PM_COMPLETED) 628 ide_complete_pm_request(drive, rq); 629 return startstop; 630 } else if (!rq->rq_disk && blk_special_request(rq)) 631 /* 632 * TODO: Once all ULDs have been modified to 633 * check for specific op codes rather than 634 * blindly accepting any special request, the 635 * check for ->rq_disk above may be replaced 636 * by a more suitable mechanism or even 637 * dropped entirely. 638 */ 639 return ide_special_rq(drive, rq); 640 641 drv = *(ide_driver_t **)rq->rq_disk->private_data; 642 643 return drv->do_request(drive, rq, rq->sector); 644 } 645 return do_special(drive); 646kill_rq: 647 ide_kill_rq(drive, rq); 648 return ide_stopped; 649} 650 651/** 652 * ide_stall_queue - pause an IDE device 653 * @drive: drive to stall 654 * @timeout: time to stall for (jiffies) 655 * 656 * ide_stall_queue() can be used by a drive to give excess bandwidth back 657 * to the hwgroup by sleeping for timeout jiffies. 658 */ 659 660void ide_stall_queue (ide_drive_t *drive, unsigned long timeout) 661{ 662 if (timeout > WAIT_WORSTCASE) 663 timeout = WAIT_WORSTCASE; 664 drive->sleep = timeout + jiffies; 665 drive->dev_flags |= IDE_DFLAG_SLEEPING; 666} 667EXPORT_SYMBOL(ide_stall_queue); 668 669/* 670 * Issue a new request to a drive from hwgroup 671 * 672 * A hwgroup is a serialized group of IDE interfaces. Usually there is 673 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640) 674 * may have both interfaces in a single hwgroup to "serialize" access. 675 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped 676 * together into one hwgroup for serialized access. 677 * 678 * Note also that several hwgroups can end up sharing a single IRQ, 679 * possibly along with many other devices. This is especially common in 680 * PCI-based systems with off-board IDE controller cards. 681 * 682 * The IDE driver uses a per-hwgroup lock to protect the hwgroup->busy flag. 683 * 684 * The first thread into the driver for a particular hwgroup sets the 685 * hwgroup->busy flag to indicate that this hwgroup is now active, 686 * and then initiates processing of the top request from the request queue. 687 * 688 * Other threads attempting entry notice the busy setting, and will simply 689 * queue their new requests and exit immediately. Note that hwgroup->busy 690 * remains set even when the driver is merely awaiting the next interrupt. 691 * Thus, the meaning is "this hwgroup is busy processing a request". 692 * 693 * When processing of a request completes, the completing thread or IRQ-handler 694 * will start the next request from the queue. If no more work remains, 695 * the driver will clear the hwgroup->busy flag and exit. 696 * 697 * The per-hwgroup spinlock is used to protect all access to the 698 * hwgroup->busy flag, but is otherwise not needed for most processing in 699 * the driver. This makes the driver much more friendlier to shared IRQs 700 * than previous designs, while remaining 100% (?) SMP safe and capable. 701 */ 702void do_ide_request(struct request_queue *q) 703{ 704 ide_drive_t *drive = q->queuedata; 705 ide_hwif_t *hwif = drive->hwif; 706 ide_hwgroup_t *hwgroup = hwif->hwgroup; 707 struct request *rq; 708 ide_startstop_t startstop; 709 710 /* 711 * drive is doing pre-flush, ordered write, post-flush sequence. even 712 * though that is 3 requests, it must be seen as a single transaction. 713 * we must not preempt this drive until that is complete 714 */ 715 if (blk_queue_flushing(q)) 716 /* 717 * small race where queue could get replugged during 718 * the 3-request flush cycle, just yank the plug since 719 * we want it to finish asap 720 */ 721 blk_remove_plug(q); 722 723 spin_unlock_irq(q->queue_lock); 724 spin_lock_irq(&hwgroup->lock); 725 726 if (!ide_lock_hwgroup(hwgroup)) { 727repeat: 728 hwgroup->rq = NULL; 729 730 if (drive->dev_flags & IDE_DFLAG_SLEEPING) { 731 if (time_before(drive->sleep, jiffies)) { 732 ide_unlock_hwgroup(hwgroup); 733 goto plug_device; 734 } 735 } 736 737 if (hwif != hwgroup->hwif) { 738 /* 739 * set nIEN for previous hwif, drives in the 740 * quirk_list may not like intr setups/cleanups 741 */ 742 if (drive->quirk_list == 0) 743 hwif->tp_ops->set_irq(hwif, 0); 744 } 745 hwgroup->hwif = hwif; 746 hwgroup->drive = drive; 747 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED); 748 749 spin_unlock_irq(&hwgroup->lock); 750 spin_lock_irq(q->queue_lock); 751 /* 752 * we know that the queue isn't empty, but this can happen 753 * if the q->prep_rq_fn() decides to kill a request 754 */ 755 rq = elv_next_request(drive->queue); 756 spin_unlock_irq(q->queue_lock); 757 spin_lock_irq(&hwgroup->lock); 758 759 if (!rq) { 760 ide_unlock_hwgroup(hwgroup); 761 goto out; 762 } 763 764 /* 765 * Sanity: don't accept a request that isn't a PM request 766 * if we are currently power managed. This is very important as 767 * blk_stop_queue() doesn't prevent the elv_next_request() 768 * above to return us whatever is in the queue. Since we call 769 * ide_do_request() ourselves, we end up taking requests while 770 * the queue is blocked... 771 * 772 * We let requests forced at head of queue with ide-preempt 773 * though. I hope that doesn't happen too much, hopefully not 774 * unless the subdriver triggers such a thing in its own PM 775 * state machine. 776 */ 777 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) && 778 blk_pm_request(rq) == 0 && 779 (rq->cmd_flags & REQ_PREEMPT) == 0) { 780 /* there should be no pending command at this point */ 781 ide_unlock_hwgroup(hwgroup); 782 goto plug_device; 783 } 784 785 hwgroup->rq = rq; 786 787 spin_unlock_irq(&hwgroup->lock); 788 startstop = start_request(drive, rq); 789 spin_lock_irq(&hwgroup->lock); 790 791 if (startstop == ide_stopped) 792 goto repeat; 793 } else 794 goto plug_device; 795out: 796 spin_unlock_irq(&hwgroup->lock); 797 spin_lock_irq(q->queue_lock); 798 return; 799 800plug_device: 801 spin_unlock_irq(&hwgroup->lock); 802 spin_lock_irq(q->queue_lock); 803 804 if (!elv_queue_empty(q)) 805 blk_plug_device(q); 806} 807 808/* 809 * un-busy the hwgroup etc, and clear any pending DMA status. we want to 810 * retry the current request in pio mode instead of risking tossing it 811 * all away 812 */ 813static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error) 814{ 815 ide_hwif_t *hwif = HWIF(drive); 816 struct request *rq; 817 ide_startstop_t ret = ide_stopped; 818 819 /* 820 * end current dma transaction 821 */ 822 823 if (error < 0) { 824 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name); 825 (void)hwif->dma_ops->dma_end(drive); 826 ret = ide_error(drive, "dma timeout error", 827 hwif->tp_ops->read_status(hwif)); 828 } else { 829 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name); 830 hwif->dma_ops->dma_timeout(drive); 831 } 832 833 /* 834 * disable dma for now, but remember that we did so because of 835 * a timeout -- we'll reenable after we finish this next request 836 * (or rather the first chunk of it) in pio. 837 */ 838 drive->dev_flags |= IDE_DFLAG_DMA_PIO_RETRY; 839 drive->retry_pio++; 840 ide_dma_off_quietly(drive); 841 842 /* 843 * un-busy drive etc (hwgroup->busy is cleared on return) and 844 * make sure request is sane 845 */ 846 rq = HWGROUP(drive)->rq; 847 848 if (!rq) 849 goto out; 850 851 HWGROUP(drive)->rq = NULL; 852 853 rq->errors = 0; 854 855 if (!rq->bio) 856 goto out; 857 858 rq->sector = rq->bio->bi_sector; 859 rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9; 860 rq->hard_cur_sectors = rq->current_nr_sectors; 861 rq->buffer = bio_data(rq->bio); 862out: 863 return ret; 864} 865 866static void ide_plug_device(ide_drive_t *drive) 867{ 868 struct request_queue *q = drive->queue; 869 unsigned long flags; 870 871 spin_lock_irqsave(q->queue_lock, flags); 872 if (!elv_queue_empty(q)) 873 blk_plug_device(q); 874 spin_unlock_irqrestore(q->queue_lock, flags); 875} 876 877/** 878 * ide_timer_expiry - handle lack of an IDE interrupt 879 * @data: timer callback magic (hwgroup) 880 * 881 * An IDE command has timed out before the expected drive return 882 * occurred. At this point we attempt to clean up the current 883 * mess. If the current handler includes an expiry handler then 884 * we invoke the expiry handler, and providing it is happy the 885 * work is done. If that fails we apply generic recovery rules 886 * invoking the handler and checking the drive DMA status. We 887 * have an excessively incestuous relationship with the DMA 888 * logic that wants cleaning up. 889 */ 890 891void ide_timer_expiry (unsigned long data) 892{ 893 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data; 894 ide_drive_t *uninitialized_var(drive); 895 ide_handler_t *handler; 896 ide_expiry_t *expiry; 897 unsigned long flags; 898 unsigned long wait = -1; 899 int plug_device = 0; 900 901 spin_lock_irqsave(&hwgroup->lock, flags); 902 903 if (((handler = hwgroup->handler) == NULL) || 904 (hwgroup->req_gen != hwgroup->req_gen_timer)) { 905 /* 906 * Either a marginal timeout occurred 907 * (got the interrupt just as timer expired), 908 * or we were "sleeping" to give other devices a chance. 909 * Either way, we don't really want to complain about anything. 910 */ 911 } else { 912 drive = hwgroup->drive; 913 if (!drive) { 914 printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n"); 915 hwgroup->handler = NULL; 916 } else { 917 ide_hwif_t *hwif; 918 ide_startstop_t startstop = ide_stopped; 919 920 if ((expiry = hwgroup->expiry) != NULL) { 921 /* continue */ 922 if ((wait = expiry(drive)) > 0) { 923 /* reset timer */ 924 hwgroup->timer.expires = jiffies + wait; 925 hwgroup->req_gen_timer = hwgroup->req_gen; 926 add_timer(&hwgroup->timer); 927 spin_unlock_irqrestore(&hwgroup->lock, flags); 928 return; 929 } 930 } 931 hwgroup->handler = NULL; 932 /* 933 * We need to simulate a real interrupt when invoking 934 * the handler() function, which means we need to 935 * globally mask the specific IRQ: 936 */ 937 spin_unlock(&hwgroup->lock); 938 hwif = HWIF(drive); 939 /* disable_irq_nosync ?? */ 940 disable_irq(hwif->irq); 941 /* local CPU only, 942 * as if we were handling an interrupt */ 943 local_irq_disable(); 944 if (hwgroup->polling) { 945 startstop = handler(drive); 946 } else if (drive_is_ready(drive)) { 947 if (drive->waiting_for_dma) 948 hwif->dma_ops->dma_lost_irq(drive); 949 (void)ide_ack_intr(hwif); 950 printk(KERN_WARNING "%s: lost interrupt\n", drive->name); 951 startstop = handler(drive); 952 } else { 953 if (drive->waiting_for_dma) { 954 startstop = ide_dma_timeout_retry(drive, wait); 955 } else 956 startstop = 957 ide_error(drive, "irq timeout", 958 hwif->tp_ops->read_status(hwif)); 959 } 960 spin_lock_irq(&hwgroup->lock); 961 enable_irq(hwif->irq); 962 if (startstop == ide_stopped) { 963 ide_unlock_hwgroup(hwgroup); 964 plug_device = 1; 965 } 966 } 967 } 968 spin_unlock_irqrestore(&hwgroup->lock, flags); 969 970 if (plug_device) 971 ide_plug_device(drive); 972} 973 974/** 975 * unexpected_intr - handle an unexpected IDE interrupt 976 * @irq: interrupt line 977 * @hwgroup: hwgroup being processed 978 * 979 * There's nothing really useful we can do with an unexpected interrupt, 980 * other than reading the status register (to clear it), and logging it. 981 * There should be no way that an irq can happen before we're ready for it, 982 * so we needn't worry much about losing an "important" interrupt here. 983 * 984 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever 985 * the drive enters "idle", "standby", or "sleep" mode, so if the status 986 * looks "good", we just ignore the interrupt completely. 987 * 988 * This routine assumes __cli() is in effect when called. 989 * 990 * If an unexpected interrupt happens on irq15 while we are handling irq14 991 * and if the two interfaces are "serialized" (CMD640), then it looks like 992 * we could screw up by interfering with a new request being set up for 993 * irq15. 994 * 995 * In reality, this is a non-issue. The new command is not sent unless 996 * the drive is ready to accept one, in which case we know the drive is 997 * not trying to interrupt us. And ide_set_handler() is always invoked 998 * before completing the issuance of any new drive command, so we will not 999 * be accidentally invoked as a result of any valid command completion 1000 * interrupt. 1001 * 1002 * Note that we must walk the entire hwgroup here. We know which hwif 1003 * is doing the current command, but we don't know which hwif burped 1004 * mysteriously. 1005 */ 1006 1007static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup) 1008{ 1009 u8 stat; 1010 ide_hwif_t *hwif = hwgroup->hwif; 1011 1012 /* 1013 * handle the unexpected interrupt 1014 */ 1015 do { 1016 if (hwif->irq == irq) { 1017 stat = hwif->tp_ops->read_status(hwif); 1018 1019 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) { 1020 /* Try to not flood the console with msgs */ 1021 static unsigned long last_msgtime, count; 1022 ++count; 1023 if (time_after(jiffies, last_msgtime + HZ)) { 1024 last_msgtime = jiffies; 1025 printk(KERN_ERR "%s%s: unexpected interrupt, " 1026 "status=0x%02x, count=%ld\n", 1027 hwif->name, 1028 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count); 1029 } 1030 } 1031 } 1032 } while ((hwif = hwif->next) != hwgroup->hwif); 1033} 1034 1035/** 1036 * ide_intr - default IDE interrupt handler 1037 * @irq: interrupt number 1038 * @dev_id: hwif group 1039 * @regs: unused weirdness from the kernel irq layer 1040 * 1041 * This is the default IRQ handler for the IDE layer. You should 1042 * not need to override it. If you do be aware it is subtle in 1043 * places 1044 * 1045 * hwgroup->hwif is the interface in the group currently performing 1046 * a command. hwgroup->drive is the drive and hwgroup->handler is 1047 * the IRQ handler to call. As we issue a command the handlers 1048 * step through multiple states, reassigning the handler to the 1049 * next step in the process. Unlike a smart SCSI controller IDE 1050 * expects the main processor to sequence the various transfer 1051 * stages. We also manage a poll timer to catch up with most 1052 * timeout situations. There are still a few where the handlers 1053 * don't ever decide to give up. 1054 * 1055 * The handler eventually returns ide_stopped to indicate the 1056 * request completed. At this point we issue the next request 1057 * on the hwgroup and the process begins again. 1058 */ 1059 1060irqreturn_t ide_intr (int irq, void *dev_id) 1061{ 1062 unsigned long flags; 1063 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id; 1064 ide_hwif_t *hwif = hwgroup->hwif; 1065 ide_drive_t *uninitialized_var(drive); 1066 ide_handler_t *handler; 1067 ide_startstop_t startstop; 1068 irqreturn_t irq_ret = IRQ_NONE; 1069 int plug_device = 0; 1070 1071 spin_lock_irqsave(&hwgroup->lock, flags); 1072 1073 if (!ide_ack_intr(hwif)) 1074 goto out; 1075 1076 if ((handler = hwgroup->handler) == NULL || hwgroup->polling) { 1077 /* 1078 * Not expecting an interrupt from this drive. 1079 * That means this could be: 1080 * (1) an interrupt from another PCI device 1081 * sharing the same PCI INT# as us. 1082 * or (2) a drive just entered sleep or standby mode, 1083 * and is interrupting to let us know. 1084 * or (3) a spurious interrupt of unknown origin. 1085 * 1086 * For PCI, we cannot tell the difference, 1087 * so in that case we just ignore it and hope it goes away. 1088 * 1089 * FIXME: unexpected_intr should be hwif-> then we can 1090 * remove all the ifdef PCI crap 1091 */ 1092#ifdef CONFIG_BLK_DEV_IDEPCI 1093 if (hwif->chipset != ide_pci) 1094#endif /* CONFIG_BLK_DEV_IDEPCI */ 1095 { 1096 /* 1097 * Probably not a shared PCI interrupt, 1098 * so we can safely try to do something about it: 1099 */ 1100 unexpected_intr(irq, hwgroup); 1101#ifdef CONFIG_BLK_DEV_IDEPCI 1102 } else { 1103 /* 1104 * Whack the status register, just in case 1105 * we have a leftover pending IRQ. 1106 */ 1107 (void)hwif->tp_ops->read_status(hwif); 1108#endif /* CONFIG_BLK_DEV_IDEPCI */ 1109 } 1110 goto out; 1111 } 1112 1113 drive = hwgroup->drive; 1114 if (!drive) { 1115 /* 1116 * This should NEVER happen, and there isn't much 1117 * we could do about it here. 1118 * 1119 * [Note - this can occur if the drive is hot unplugged] 1120 */ 1121 goto out_handled; 1122 } 1123 1124 if (!drive_is_ready(drive)) 1125 /* 1126 * This happens regularly when we share a PCI IRQ with 1127 * another device. Unfortunately, it can also happen 1128 * with some buggy drives that trigger the IRQ before 1129 * their status register is up to date. Hopefully we have 1130 * enough advance overhead that the latter isn't a problem. 1131 */ 1132 goto out; 1133 1134 hwgroup->handler = NULL; 1135 hwgroup->req_gen++; 1136 del_timer(&hwgroup->timer); 1137 spin_unlock(&hwgroup->lock); 1138 1139 if (hwif->port_ops && hwif->port_ops->clear_irq) 1140 hwif->port_ops->clear_irq(drive); 1141 1142 if (drive->dev_flags & IDE_DFLAG_UNMASK) 1143 local_irq_enable_in_hardirq(); 1144 1145 /* service this interrupt, may set handler for next interrupt */ 1146 startstop = handler(drive); 1147 1148 spin_lock_irq(&hwgroup->lock); 1149 /* 1150 * Note that handler() may have set things up for another 1151 * interrupt to occur soon, but it cannot happen until 1152 * we exit from this routine, because it will be the 1153 * same irq as is currently being serviced here, and Linux 1154 * won't allow another of the same (on any CPU) until we return. 1155 */ 1156 if (startstop == ide_stopped) { 1157 if (hwgroup->handler == NULL) { /* paranoia */ 1158 ide_unlock_hwgroup(hwgroup); 1159 plug_device = 1; 1160 } else 1161 printk(KERN_ERR "%s: %s: huh? expected NULL handler " 1162 "on exit\n", __func__, drive->name); 1163 } 1164out_handled: 1165 irq_ret = IRQ_HANDLED; 1166out: 1167 spin_unlock_irqrestore(&hwgroup->lock, flags); 1168 1169 if (plug_device) 1170 ide_plug_device(drive); 1171 1172 return irq_ret; 1173} 1174 1175/** 1176 * ide_do_drive_cmd - issue IDE special command 1177 * @drive: device to issue command 1178 * @rq: request to issue 1179 * 1180 * This function issues a special IDE device request 1181 * onto the request queue. 1182 * 1183 * the rq is queued at the head of the request queue, displacing 1184 * the currently-being-processed request and this function 1185 * returns immediately without waiting for the new rq to be 1186 * completed. This is VERY DANGEROUS, and is intended for 1187 * careful use by the ATAPI tape/cdrom driver code. 1188 */ 1189 1190void ide_do_drive_cmd(ide_drive_t *drive, struct request *rq) 1191{ 1192 ide_hwgroup_t *hwgroup = drive->hwif->hwgroup; 1193 struct request_queue *q = drive->queue; 1194 unsigned long flags; 1195 1196 hwgroup->rq = NULL; 1197 1198 spin_lock_irqsave(q->queue_lock, flags); 1199 __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0); 1200 spin_unlock_irqrestore(q->queue_lock, flags); 1201} 1202EXPORT_SYMBOL(ide_do_drive_cmd); 1203 1204void ide_pktcmd_tf_load(ide_drive_t *drive, u32 tf_flags, u16 bcount, u8 dma) 1205{ 1206 ide_hwif_t *hwif = drive->hwif; 1207 ide_task_t task; 1208 1209 memset(&task, 0, sizeof(task)); 1210 task.tf_flags = IDE_TFLAG_OUT_LBAH | IDE_TFLAG_OUT_LBAM | 1211 IDE_TFLAG_OUT_FEATURE | tf_flags; 1212 task.tf.feature = dma; /* Use PIO/DMA */ 1213 task.tf.lbam = bcount & 0xff; 1214 task.tf.lbah = (bcount >> 8) & 0xff; 1215 1216 ide_tf_dump(drive->name, &task.tf); 1217 hwif->tp_ops->set_irq(hwif, 1); 1218 SELECT_MASK(drive, 0); 1219 hwif->tp_ops->tf_load(drive, &task); 1220} 1221 1222EXPORT_SYMBOL_GPL(ide_pktcmd_tf_load); 1223 1224void ide_pad_transfer(ide_drive_t *drive, int write, int len) 1225{ 1226 ide_hwif_t *hwif = drive->hwif; 1227 u8 buf[4] = { 0 }; 1228 1229 while (len > 0) { 1230 if (write) 1231 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len)); 1232 else 1233 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len)); 1234 len -= 4; 1235 } 1236} 1237EXPORT_SYMBOL_GPL(ide_pad_transfer); 1238