drivers/ide/ide-io.c

   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
  58 static 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                 if (dequeue)
  89                         HWGROUP(drive)->rq = NULL;
  90                 ret = 0;
  91         }
  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
 107 int 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;
 111         unsigned long flags;
 112         int ret = 1;
 113
 114         /*
 115          * room for locking improvements here, the calls below don't
 116          * need the queue lock held at all
 117          */
 118         spin_lock_irqsave(&ide_lock, flags);
 119         rq = HWGROUP(drive)->rq;
 120
 121         if (!nr_bytes) {
 122                 if (blk_pc_request(rq))
 123                         nr_bytes = rq->data_len;
 124                 else
 125                         nr_bytes = rq->hard_cur_sectors << 9;
 126         }
 127
 128         ret = __ide_end_request(drive, rq, uptodate, nr_bytes, 1);
 129
 130         spin_unlock_irqrestore(&ide_lock, flags);
 131         return ret;
 132 }
 133 EXPORT_SYMBOL(ide_end_request);
 134
 135 static void ide_complete_power_step(ide_drive_t *drive, struct request *rq, u8 stat, u8 error)
 136 {
 137         struct request_pm_state *pm = rq->data;
 138
 139         if (drive->media != ide_disk)
 140                 return;
 141
 142         switch (pm->pm_step) {
 143         case IDE_PM_FLUSH_CACHE:        /* Suspend step 1 (flush cache) */
 144                 if (pm->pm_state == PM_EVENT_FREEZE)
 145                         pm->pm_step = IDE_PM_COMPLETED;
 146                 else
 147                         pm->pm_step = IDE_PM_STANDBY;
 148                 break;
 149         case IDE_PM_STANDBY:            /* Suspend step 2 (standby) */
 150                 pm->pm_step = IDE_PM_COMPLETED;
 151                 break;
 152         case IDE_PM_RESTORE_PIO:        /* Resume step 1 (restore PIO) */
 153                 pm->pm_step = IDE_PM_IDLE;
 154                 break;
 155         case IDE_PM_IDLE:               /* Resume step 2 (idle)*/
 156                 pm->pm_step = IDE_PM_RESTORE_DMA;
 157                 break;
 158         }
 159 }
 160
 161 static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
 162 {
 163         struct request_pm_state *pm = rq->data;
 164         ide_task_t *args = rq->special;
 165
 166         memset(args, 0, sizeof(*args));
 167
 168         switch (pm->pm_step) {
 169         case IDE_PM_FLUSH_CACHE:        /* Suspend step 1 (flush cache) */
 170                 if (drive->media != ide_disk)
 171                         break;
 172                 /* Not supported? Switch to next step now. */
 173                 if (ata_id_flush_enabled(drive->id) == 0 ||
 174                     (drive->dev_flags & IDE_DFLAG_WCACHE) == 0) {
 175                         ide_complete_power_step(drive, rq, 0, 0);
 176                         return ide_stopped;
 177                 }
 178                 if (ata_id_flush_ext_enabled(drive->id))
 179                         args->tf.command = ATA_CMD_FLUSH_EXT;
 180                 else
 181                         args->tf.command = ATA_CMD_FLUSH;
 182                 goto out_do_tf;
 183         case IDE_PM_STANDBY:            /* Suspend step 2 (standby) */
 184                 args->tf.command = ATA_CMD_STANDBYNOW1;
 185                 goto out_do_tf;
 186         case IDE_PM_RESTORE_PIO:        /* Resume step 1 (restore PIO) */
 187                 ide_set_max_pio(drive);
 188                 /*
 189                  * skip IDE_PM_IDLE for ATAPI devices
 190                  */
 191                 if (drive->media != ide_disk)
 192                         pm->pm_step = IDE_PM_RESTORE_DMA;
 193                 else
 194                         ide_complete_power_step(drive, rq, 0, 0);
 195                 return ide_stopped;
 196         case IDE_PM_IDLE:               /* Resume step 2 (idle) */
 197                 args->tf.command = ATA_CMD_IDLEIMMEDIATE;
 198                 goto out_do_tf;
 199         case IDE_PM_RESTORE_DMA:        /* Resume step 3 (restore DMA) */
 200                 /*
 201                  * Right now, all we do is call ide_set_dma(drive),
 202                  * we could be smarter and check for current xfer_speed
 203                  * in struct drive etc...
 204                  */
 205                 if (drive->hwif->dma_ops == NULL)
 206                         break;
 207                 if (drive->dev_flags & IDE_DFLAG_USING_DMA)
 208                         ide_set_dma(drive);
 209                 break;
 210         }
 211
 212         pm->pm_step = IDE_PM_COMPLETED;
 213         return ide_stopped;
 214
 215 out_do_tf:
 216         args->tf_flags   = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
 217         args->data_phase = TASKFILE_NO_DATA;
 218         return do_rw_taskfile(drive, args);
 219 }
 220
 221 /**
 222  *      ide_end_dequeued_request        -       complete an IDE I/O
 223  *      @drive: IDE device for the I/O
 224  *      @uptodate:
 225  *      @nr_sectors: number of sectors completed
 226  *
 227  *      Complete an I/O that is no longer on the request queue. This
 228  *      typically occurs when we pull the request and issue a REQUEST_SENSE.
 229  *      We must still finish the old request but we must not tamper with the
 230  *      queue in the meantime.
 231  *
 232  *      NOTE: This path does not handle barrier, but barrier is not supported
 233  *      on ide-cd anyway.
 234  */
 235
 236 int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
 237                              int uptodate, int nr_sectors)
 238 {
 239         unsigned long flags;
 240         int ret;
 241
 242         spin_lock_irqsave(&ide_lock, flags);
 243         BUG_ON(!blk_rq_started(rq));
 244         ret = __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0);
 245         spin_unlock_irqrestore(&ide_lock, flags);
 246
 247         return ret;
 248 }
 249 EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
 250
 251
 252 /**
 253  *      ide_complete_pm_request - end the current Power Management request
 254  *      @drive: target drive
 255  *      @rq: request
 256  *
 257  *      This function cleans up the current PM request and stops the queue
 258  *      if necessary.
 259  */
 260 static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
 261 {
 262         unsigned long flags;
 263
 264 #ifdef DEBUG_PM
 265         printk("%s: completing PM request, %s\n", drive->name,
 266                blk_pm_suspend_request(rq) ? "suspend" : "resume");
 267 #endif
 268         spin_lock_irqsave(&ide_lock, flags);
 269         if (blk_pm_suspend_request(rq)) {
 270                 blk_stop_queue(drive->queue);
 271         } else {
 272                 drive->dev_flags &= ~IDE_DFLAG_BLOCKED;
 273                 blk_start_queue(drive->queue);
 274         }
 275         HWGROUP(drive)->rq = NULL;
 276         if (__blk_end_request(rq, 0, 0))
 277                 BUG();
 278         spin_unlock_irqrestore(&ide_lock, flags);
 279 }
 280
 281 /**
 282  *      ide_end_drive_cmd       -       end an explicit drive command
 283  *      @drive: command
 284  *      @stat: status bits
 285  *      @err: error bits
 286  *
 287  *      Clean up after success/failure of an explicit drive command.
 288  *      These get thrown onto the queue so they are synchronized with
 289  *      real I/O operations on the drive.
 290  *
 291  *      In LBA48 mode we have to read the register set twice to get
 292  *      all the extra information out.
 293  */
 294
 295 void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
 296 {
 297         unsigned long flags;
 298         struct request *rq;
 299
 300         spin_lock_irqsave(&ide_lock, flags);
 301         rq = HWGROUP(drive)->rq;
 302         spin_unlock_irqrestore(&ide_lock, flags);
 303
 304         if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
 305                 ide_task_t *task = (ide_task_t *)rq->special;
 306
 307                 if (rq->errors == 0)
 308                         rq->errors = !OK_STAT(stat, ATA_DRDY, BAD_STAT);
 309
 310                 if (task) {
 311                         struct ide_taskfile *tf = &task->tf;
 312
 313                         tf->error = err;
 314                         tf->status = stat;
 315
 316                         drive->hwif->tp_ops->tf_read(drive, task);
 317
 318                         if (task->tf_flags & IDE_TFLAG_DYN)
 319                                 kfree(task);
 320                 }
 321         } else if (blk_pm_request(rq)) {
 322                 struct request_pm_state *pm = rq->data;
 323 #ifdef DEBUG_PM
 324                 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
 325                         drive->name, rq->pm->pm_step, stat, err);
 326 #endif
 327                 ide_complete_power_step(drive, rq, stat, err);
 328                 if (pm->pm_step == IDE_PM_COMPLETED)
 329                         ide_complete_pm_request(drive, rq);
 330                 return;
 331         }
 332
 333         spin_lock_irqsave(&ide_lock, flags);
 334         HWGROUP(drive)->rq = NULL;
 335         rq->errors = err;
 336         if (unlikely(__blk_end_request(rq, (rq->errors ? -EIO : 0),
 337                                        blk_rq_bytes(rq))))
 338                 BUG();
 339         spin_unlock_irqrestore(&ide_lock, flags);
 340 }
 341
 342 EXPORT_SYMBOL(ide_end_drive_cmd);
 343
 344 static void ide_kill_rq(ide_drive_t *drive, struct request *rq)
 345 {
 346         if (rq->rq_disk) {
 347                 ide_driver_t *drv;
 348
 349                 drv = *(ide_driver_t **)rq->rq_disk->private_data;
 350                 drv->end_request(drive, 0, 0);
 351         } else
 352                 ide_end_request(drive, 0, 0);
 353 }
 354
 355 static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
 356 {
 357         ide_hwif_t *hwif = drive->hwif;
 358
 359         if ((stat & ATA_BUSY) ||
 360             ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
 361                 /* other bits are useless when BUSY */
 362                 rq->errors |= ERROR_RESET;
 363         } else if (stat & ATA_ERR) {
 364                 /* err has different meaning on cdrom and tape */
 365                 if (err == ATA_ABORTED) {
 366                         if ((drive->dev_flags & IDE_DFLAG_LBA) &&
 367                             /* some newer drives don't support ATA_CMD_INIT_DEV_PARAMS */
 368                             hwif->tp_ops->read_status(hwif) == ATA_CMD_INIT_DEV_PARAMS)
 369                                 return ide_stopped;
 370                 } else if ((err & BAD_CRC) == BAD_CRC) {
 371                         /* UDMA crc error, just retry the operation */
 372                         drive->crc_count++;
 373                 } else if (err & (ATA_BBK | ATA_UNC)) {
 374                         /* retries won't help these */
 375                         rq->errors = ERROR_MAX;
 376                 } else if (err & ATA_TRK0NF) {
 377                         /* help it find track zero */
 378                         rq->errors |= ERROR_RECAL;
 379                 }
 380         }
 381
 382         if ((stat & ATA_DRQ) && rq_data_dir(rq) == READ &&
 383             (hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0) {
 384                 int nsect = drive->mult_count ? drive->mult_count : 1;
 385
 386                 ide_pad_transfer(drive, READ, nsect * SECTOR_SIZE);
 387         }
 388
 389         if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) {
 390                 ide_kill_rq(drive, rq);
 391                 return ide_stopped;
 392         }
 393
 394         if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
 395                 rq->errors |= ERROR_RESET;
 396
 397         if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
 398                 ++rq->errors;
 399                 return ide_do_reset(drive);
 400         }
 401
 402         if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
 403                 drive->special.b.recalibrate = 1;
 404
 405         ++rq->errors;
 406
 407         return ide_stopped;
 408 }
 409
 410 static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
 411 {
 412         ide_hwif_t *hwif = drive->hwif;
 413
 414         if ((stat & ATA_BUSY) ||
 415             ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
 416                 /* other bits are useless when BUSY */
 417                 rq->errors |= ERROR_RESET;
 418         } else {
 419                 /* add decoding error stuff */
 420         }
 421
 422         if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
 423                 /* force an abort */
 424                 hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE);
 425
 426         if (rq->errors >= ERROR_MAX) {
 427                 ide_kill_rq(drive, rq);
 428         } else {
 429                 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
 430                         ++rq->errors;
 431                         return ide_do_reset(drive);
 432                 }
 433                 ++rq->errors;
 434         }
 435
 436         return ide_stopped;
 437 }
 438
 439 ide_startstop_t
 440 __ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
 441 {
 442         if (drive->media == ide_disk)
 443                 return ide_ata_error(drive, rq, stat, err);
 444         return ide_atapi_error(drive, rq, stat, err);
 445 }
 446
 447 EXPORT_SYMBOL_GPL(__ide_error);
 448
 449 /**
 450  *      ide_error       -       handle an error on the IDE
 451  *      @drive: drive the error occurred on
 452  *      @msg: message to report
 453  *      @stat: status bits
 454  *
 455  *      ide_error() takes action based on the error returned by the drive.
 456  *      For normal I/O that may well include retries. We deal with
 457  *      both new-style (taskfile) and old style command handling here.
 458  *      In the case of taskfile command handling there is work left to
 459  *      do
 460  */
 461
 462 ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
 463 {
 464         struct request *rq;
 465         u8 err;
 466
 467         err = ide_dump_status(drive, msg, stat);
 468
 469         if ((rq = HWGROUP(drive)->rq) == NULL)
 470                 return ide_stopped;
 471
 472         /* retry only "normal" I/O: */
 473         if (!blk_fs_request(rq)) {
 474                 rq->errors = 1;
 475                 ide_end_drive_cmd(drive, stat, err);
 476                 return ide_stopped;
 477         }
 478
 479         if (rq->rq_disk) {
 480                 ide_driver_t *drv;
 481
 482                 drv = *(ide_driver_t **)rq->rq_disk->private_data;
 483                 return drv->error(drive, rq, stat, err);
 484         } else
 485                 return __ide_error(drive, rq, stat, err);
 486 }
 487
 488 EXPORT_SYMBOL_GPL(ide_error);
 489
 490 static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
 491 {
 492         tf->nsect   = drive->sect;
 493         tf->lbal    = drive->sect;
 494         tf->lbam    = drive->cyl;
 495         tf->lbah    = drive->cyl >> 8;
 496         tf->device  = (drive->head - 1) | drive->select;
 497         tf->command = ATA_CMD_INIT_DEV_PARAMS;
 498 }
 499
 500 static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
 501 {
 502         tf->nsect   = drive->sect;
 503         tf->command = ATA_CMD_RESTORE;
 504 }
 505
 506 static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
 507 {
 508         tf->nsect   = drive->mult_req;
 509         tf->command = ATA_CMD_SET_MULTI;
 510 }
 511
 512 static ide_startstop_t ide_disk_special(ide_drive_t *drive)
 513 {
 514         special_t *s = &drive->special;
 515         ide_task_t args;
 516
 517         memset(&args, 0, sizeof(ide_task_t));
 518         args.data_phase = TASKFILE_NO_DATA;
 519
 520         if (s->b.set_geometry) {
 521                 s->b.set_geometry = 0;
 522                 ide_tf_set_specify_cmd(drive, &args.tf);
 523         } else if (s->b.recalibrate) {
 524                 s->b.recalibrate = 0;
 525                 ide_tf_set_restore_cmd(drive, &args.tf);
 526         } else if (s->b.set_multmode) {
 527                 s->b.set_multmode = 0;
 528                 ide_tf_set_setmult_cmd(drive, &args.tf);
 529         } else if (s->all) {
 530                 int special = s->all;
 531                 s->all = 0;
 532                 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
 533                 return ide_stopped;
 534         }
 535
 536         args.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE |
 537                         IDE_TFLAG_CUSTOM_HANDLER;
 538
 539         do_rw_taskfile(drive, &args);
 540
 541         return ide_started;
 542 }
 543
 544 /**
 545  *      do_special              -       issue some special commands
 546  *      @drive: drive the command is for
 547  *
 548  *      do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
 549  *      ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
 550  *
 551  *      It used to do much more, but has been scaled back.
 552  */
 553
 554 static ide_startstop_t do_special (ide_drive_t *drive)
 555 {
 556         special_t *s = &drive->special;
 557
 558 #ifdef DEBUG
 559         printk("%s: do_special: 0x%02x\n", drive->name, s->all);
 560 #endif
 561         if (drive->media == ide_disk)
 562                 return ide_disk_special(drive);
 563
 564         s->all = 0;
 565         drive->mult_req = 0;
 566         return ide_stopped;
 567 }
 568
 569 void ide_map_sg(ide_drive_t *drive, struct request *rq)
 570 {
 571         ide_hwif_t *hwif = drive->hwif;
 572         struct scatterlist *sg = hwif->sg_table;
 573
 574         if (hwif->sg_mapped)    /* needed by ide-scsi */
 575                 return;
 576
 577         if (rq->cmd_type != REQ_TYPE_ATA_TASKFILE) {
 578                 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
 579         } else {
 580                 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
 581                 hwif->sg_nents = 1;
 582         }
 583 }
 584
 585 EXPORT_SYMBOL_GPL(ide_map_sg);
 586
 587 void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
 588 {
 589         ide_hwif_t *hwif = drive->hwif;
 590
 591         hwif->nsect = hwif->nleft = rq->nr_sectors;
 592         hwif->cursg_ofs = 0;
 593         hwif->cursg = NULL;
 594 }
 595
 596 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
 597
 598 /**
 599  *      execute_drive_command   -       issue special drive command
 600  *      @drive: the drive to issue the command on
 601  *      @rq: the request structure holding the command
 602  *
 603  *      execute_drive_cmd() issues a special drive command,  usually
 604  *      initiated by ioctl() from the external hdparm program. The
 605  *      command can be a drive command, drive task or taskfile
 606  *      operation. Weirdly you can call it with NULL to wait for
 607  *      all commands to finish. Don't do this as that is due to change
 608  */
 609
 610 static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
 611                 struct request *rq)
 612 {
 613         ide_hwif_t *hwif = HWIF(drive);
 614         ide_task_t *task = rq->special;
 615
 616         if (task) {
 617                 hwif->data_phase = task->data_phase;
 618
 619                 switch (hwif->data_phase) {
 620                 case TASKFILE_MULTI_OUT:
 621                 case TASKFILE_OUT:
 622                 case TASKFILE_MULTI_IN:
 623                 case TASKFILE_IN:
 624                         ide_init_sg_cmd(drive, rq);
 625                         ide_map_sg(drive, rq);
 626                 default:
 627                         break;
 628                 }
 629
 630                 return do_rw_taskfile(drive, task);
 631         }
 632
 633         /*
 634          * NULL is actually a valid way of waiting for
 635          * all current requests to be flushed from the queue.
 636          */
 637 #ifdef DEBUG
 638         printk("%s: DRIVE_CMD (null)\n", drive->name);
 639 #endif
 640         ide_end_drive_cmd(drive, hwif->tp_ops->read_status(hwif),
 641                           ide_read_error(drive));
 642
 643         return ide_stopped;
 644 }
 645
 646 int ide_devset_execute(ide_drive_t *drive, const struct ide_devset *setting,
 647                        int arg)
 648 {
 649         struct request_queue *q = drive->queue;
 650         struct request *rq;
 651         int ret = 0;
 652
 653         if (!(setting->flags & DS_SYNC))
 654                 return setting->set(drive, arg);
 655
 656         rq = blk_get_request(q, READ, __GFP_WAIT);
 657         rq->cmd_type = REQ_TYPE_SPECIAL;
 658         rq->cmd_len = 5;
 659         rq->cmd[0] = REQ_DEVSET_EXEC;
 660         *(int *)&rq->cmd[1] = arg;
 661         rq->special = setting->set;
 662
 663         if (blk_execute_rq(q, NULL, rq, 0))
 664                 ret = rq->errors;
 665         blk_put_request(rq);
 666
 667         return ret;
 668 }
 669 EXPORT_SYMBOL_GPL(ide_devset_execute);
 670
 671 static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
 672 {
 673         u8 cmd = rq->cmd[0];
 674
 675         if (cmd == REQ_PARK_HEADS || cmd == REQ_UNPARK_HEADS) {
 676                 ide_task_t task;
 677                 struct ide_taskfile *tf = &task.tf;
 678
 679                 memset(&task, 0, sizeof(task));
 680                 if (cmd == REQ_PARK_HEADS) {
 681                         drive->sleep = *(unsigned long *)rq->special;
 682                         drive->dev_flags |= IDE_DFLAG_SLEEPING;
 683                         tf->command = ATA_CMD_IDLEIMMEDIATE;
 684                         tf->feature = 0x44;
 685                         tf->lbal = 0x4c;
 686                         tf->lbam = 0x4e;
 687                         tf->lbah = 0x55;
 688                         task.tf_flags |= IDE_TFLAG_CUSTOM_HANDLER;
 689                 } else          /* cmd == REQ_UNPARK_HEADS */
 690                         tf->command = ATA_CMD_CHK_POWER;
 691
 692                 task.tf_flags |= IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
 693                 task.rq = rq;
 694                 drive->hwif->data_phase = task.data_phase = TASKFILE_NO_DATA;
 695                 return do_rw_taskfile(drive, &task);
 696         }
 697
 698         switch (cmd) {
 699         case REQ_DEVSET_EXEC:
 700         {
 701                 int err, (*setfunc)(ide_drive_t *, int) = rq->special;
 702
 703                 err = setfunc(drive, *(int *)&rq->cmd[1]);
 704                 if (err)
 705                         rq->errors = err;
 706                 else
 707                         err = 1;
 708                 ide_end_request(drive, err, 0);
 709                 return ide_stopped;
 710         }
 711         case REQ_DRIVE_RESET:
 712                 return ide_do_reset(drive);
 713         default:
 714                 blk_dump_rq_flags(rq, "ide_special_rq - bad request");
 715                 ide_end_request(drive, 0, 0);
 716                 return ide_stopped;
 717         }
 718 }
 719
 720 static void ide_check_pm_state(ide_drive_t *drive, struct request *rq)
 721 {
 722         struct request_pm_state *pm = rq->data;
 723
 724         if (blk_pm_suspend_request(rq) &&
 725             pm->pm_step == IDE_PM_START_SUSPEND)
 726                 /* Mark drive blocked when starting the suspend sequence. */
 727                 drive->dev_flags |= IDE_DFLAG_BLOCKED;
 728         else if (blk_pm_resume_request(rq) &&
 729                  pm->pm_step == IDE_PM_START_RESUME) {
 730                 /*
 731                  * The first thing we do on wakeup is to wait for BSY bit to
 732                  * go away (with a looong timeout) as a drive on this hwif may
 733                  * just be POSTing itself.
 734                  * We do that before even selecting as the "other" device on
 735                  * the bus may be broken enough to walk on our toes at this
 736                  * point.
 737                  */
 738                 ide_hwif_t *hwif = drive->hwif;
 739                 int rc;
 740 #ifdef DEBUG_PM
 741                 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
 742 #endif
 743                 rc = ide_wait_not_busy(hwif, 35000);
 744                 if (rc)
 745                         printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
 746                 SELECT_DRIVE(drive);
 747                 hwif->tp_ops->set_irq(hwif, 1);
 748                 rc = ide_wait_not_busy(hwif, 100000);
 749                 if (rc)
 750                         printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
 751         }
 752 }
 753
 754 /**
 755  *      start_request   -       start of I/O and command issuing for IDE
 756  *
 757  *      start_request() initiates handling of a new I/O request. It
 758  *      accepts commands and I/O (read/write) requests.
 759  *
 760  *      FIXME: this function needs a rename
 761  */
 762
 763 static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
 764 {
 765         ide_startstop_t startstop;
 766
 767         BUG_ON(!blk_rq_started(rq));
 768
 769 #ifdef DEBUG
 770         printk("%s: start_request: current=0x%08lx\n",
 771                 HWIF(drive)->name, (unsigned long) rq);
 772 #endif
 773
 774         /* bail early if we've exceeded max_failures */
 775         if (drive->max_failures && (drive->failures > drive->max_failures)) {
 776                 rq->cmd_flags |= REQ_FAILED;
 777                 goto kill_rq;
 778         }
 779
 780         if (blk_pm_request(rq))
 781                 ide_check_pm_state(drive, rq);
 782
 783         SELECT_DRIVE(drive);
 784         if (ide_wait_stat(&startstop, drive, drive->ready_stat,
 785                           ATA_BUSY | ATA_DRQ, WAIT_READY)) {
 786                 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
 787                 return startstop;
 788         }
 789         if (!drive->special.all) {
 790                 ide_driver_t *drv;
 791
 792                 /*
 793                  * We reset the drive so we need to issue a SETFEATURES.
 794                  * Do it _after_ do_special() restored device parameters.
 795                  */
 796                 if (drive->current_speed == 0xff)
 797                         ide_config_drive_speed(drive, drive->desired_speed);
 798
 799                 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
 800                         return execute_drive_cmd(drive, rq);
 801                 else if (blk_pm_request(rq)) {
 802                         struct request_pm_state *pm = rq->data;
 803 #ifdef DEBUG_PM
 804                         printk("%s: start_power_step(step: %d)\n",
 805                                 drive->name, rq->pm->pm_step);
 806 #endif
 807                         startstop = ide_start_power_step(drive, rq);
 808                         if (startstop == ide_stopped &&
 809                             pm->pm_step == IDE_PM_COMPLETED)
 810                                 ide_complete_pm_request(drive, rq);
 811                         return startstop;
 812                 } else if (!rq->rq_disk && blk_special_request(rq))
 813                         /*
 814                          * TODO: Once all ULDs have been modified to
 815                          * check for specific op codes rather than
 816                          * blindly accepting any special request, the
 817                          * check for ->rq_disk above may be replaced
 818                          * by a more suitable mechanism or even
 819                          * dropped entirely.
 820                          */
 821                         return ide_special_rq(drive, rq);
 822
 823                 drv = *(ide_driver_t **)rq->rq_disk->private_data;
 824
 825                 return drv->do_request(drive, rq, rq->sector);
 826         }
 827         return do_special(drive);
 828 kill_rq:
 829         ide_kill_rq(drive, rq);
 830         return ide_stopped;
 831 }
 832
 833 /**
 834  *      ide_stall_queue         -       pause an IDE device
 835  *      @drive: drive to stall
 836  *      @timeout: time to stall for (jiffies)
 837  *
 838  *      ide_stall_queue() can be used by a drive to give excess bandwidth back
 839  *      to the hwgroup by sleeping for timeout jiffies.
 840  */
 841
 842 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
 843 {
 844         if (timeout > WAIT_WORSTCASE)
 845                 timeout = WAIT_WORSTCASE;
 846         drive->sleep = timeout + jiffies;
 847         drive->dev_flags |= IDE_DFLAG_SLEEPING;
 848 }
 849
 850 EXPORT_SYMBOL(ide_stall_queue);
 851
 852 #define WAKEUP(drive)   ((drive)->service_start + 2 * (drive)->service_time)
 853
 854 /**
 855  *      choose_drive            -       select a drive to service
 856  *      @hwgroup: hardware group to select on
 857  *
 858  *      choose_drive() selects the next drive which will be serviced.
 859  *      This is necessary because the IDE layer can't issue commands
 860  *      to both drives on the same cable, unlike SCSI.
 861  */
 862
 863 static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
 864 {
 865         ide_drive_t *drive, *best;
 866
 867 repeat:
 868         best = NULL;
 869         drive = hwgroup->drive;
 870
 871         /*
 872          * drive is doing pre-flush, ordered write, post-flush sequence. even
 873          * though that is 3 requests, it must be seen as a single transaction.
 874          * we must not preempt this drive until that is complete
 875          */
 876         if (blk_queue_flushing(drive->queue)) {
 877                 /*
 878                  * small race where queue could get replugged during
 879                  * the 3-request flush cycle, just yank the plug since
 880                  * we want it to finish asap
 881                  */
 882                 blk_remove_plug(drive->queue);
 883                 return drive;
 884         }
 885
 886         do {
 887                 u8 dev_s = !!(drive->dev_flags & IDE_DFLAG_SLEEPING);
 888                 u8 best_s = (best && !!(best->dev_flags & IDE_DFLAG_SLEEPING));
 889
 890                 if ((dev_s == 0 || time_after_eq(jiffies, drive->sleep)) &&
 891                     !elv_queue_empty(drive->queue)) {
 892                         if (best == NULL ||
 893                             (dev_s && (best_s == 0 || time_before(drive->sleep, best->sleep))) ||
 894                             (best_s == 0 && time_before(WAKEUP(drive), WAKEUP(best)))) {
 895                                 if (!blk_queue_plugged(drive->queue))
 896                                         best = drive;
 897                         }
 898                 }
 899         } while ((drive = drive->next) != hwgroup->drive);
 900
 901         if (best && (best->dev_flags & IDE_DFLAG_NICE1) &&
 902             (best->dev_flags & IDE_DFLAG_SLEEPING) == 0 &&
 903             best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
 904                 long t = (signed long)(WAKEUP(best) - jiffies);
 905                 if (t >= WAIT_MIN_SLEEP) {
 906                 /*
 907                  * We *may* have some time to spare, but first let's see if
 908                  * someone can potentially benefit from our nice mood today..
 909                  */
 910                         drive = best->next;
 911                         do {
 912                                 if ((drive->dev_flags & IDE_DFLAG_SLEEPING) == 0
 913                                  && time_before(jiffies - best->service_time, WAKEUP(drive))
 914                                  && time_before(WAKEUP(drive), jiffies + t))
 915                                 {
 916                                         ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
 917                                         goto repeat;
 918                                 }
 919                         } while ((drive = drive->next) != best);
 920                 }
 921         }
 922         return best;
 923 }
 924
 925 /*
 926  * Issue a new request to a drive from hwgroup
 927  * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
 928  *
 929  * A hwgroup is a serialized group of IDE interfaces.  Usually there is
 930  * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
 931  * may have both interfaces in a single hwgroup to "serialize" access.
 932  * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
 933  * together into one hwgroup for serialized access.
 934  *
 935  * Note also that several hwgroups can end up sharing a single IRQ,
 936  * possibly along with many other devices.  This is especially common in
 937  * PCI-based systems with off-board IDE controller cards.
 938  *
 939  * The IDE driver uses the single global ide_lock spinlock to protect
 940  * access to the request queues, and to protect the hwgroup->busy flag.
 941  *
 942  * The first thread into the driver for a particular hwgroup sets the
 943  * hwgroup->busy flag to indicate that this hwgroup is now active,
 944  * and then initiates processing of the top request from the request queue.
 945  *
 946  * Other threads attempting entry notice the busy setting, and will simply
 947  * queue their new requests and exit immediately.  Note that hwgroup->busy
 948  * remains set even when the driver is merely awaiting the next interrupt.
 949  * Thus, the meaning is "this hwgroup is busy processing a request".
 950  *
 951  * When processing of a request completes, the completing thread or IRQ-handler
 952  * will start the next request from the queue.  If no more work remains,
 953  * the driver will clear the hwgroup->busy flag and exit.
 954  *
 955  * The ide_lock (spinlock) is used to protect all access to the
 956  * hwgroup->busy flag, but is otherwise not needed for most processing in
 957  * the driver.  This makes the driver much more friendlier to shared IRQs
 958  * than previous designs, while remaining 100% (?) SMP safe and capable.
 959  */
 960 static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
 961 {
 962         ide_drive_t     *drive;
 963         ide_hwif_t      *hwif;
 964         struct request  *rq;
 965         ide_startstop_t startstop;
 966         int             loops = 0;
 967
 968         /* caller must own ide_lock */
 969         BUG_ON(!irqs_disabled());
 970
 971         while (!hwgroup->busy) {
 972                 hwgroup->busy = 1;
 973                 /* for atari only */
 974                 ide_get_lock(ide_intr, hwgroup);
 975                 drive = choose_drive(hwgroup);
 976                 if (drive == NULL) {
 977                         int sleeping = 0;
 978                         unsigned long sleep = 0; /* shut up, gcc */
 979                         hwgroup->rq = NULL;
 980                         drive = hwgroup->drive;
 981                         do {
 982                                 if ((drive->dev_flags & IDE_DFLAG_SLEEPING) &&
 983                                     (sleeping == 0 ||
 984                                      time_before(drive->sleep, sleep))) {
 985                                         sleeping = 1;
 986                                         sleep = drive->sleep;
 987                                 }
 988                         } while ((drive = drive->next) != hwgroup->drive);
 989                         if (sleeping) {
 990                 /*
 991                  * Take a short snooze, and then wake up this hwgroup again.
 992                  * This gives other hwgroups on the same a chance to
 993                  * play fairly with us, just in case there are big differences
 994                  * in relative throughputs.. don't want to hog the cpu too much.
 995                  */
 996                                 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
 997                                         sleep = jiffies + WAIT_MIN_SLEEP;
 998 #if 1
 999                                 if (timer_pending(&hwgroup->timer))
1000                                         printk(KERN_CRIT "ide_set_handler: timer already active\n");
1001 #endif
1002                                 /* so that ide_timer_expiry knows what to do */
1003                                 hwgroup->sleeping = 1;
1004                                 hwgroup->req_gen_timer = hwgroup->req_gen;
1005                                 mod_timer(&hwgroup->timer, sleep);
1006                                 /* we purposely leave hwgroup->busy==1
1007                                  * while sleeping */
1008                         } else {
1009                                 /* Ugly, but how can we sleep for the lock
1010                                  * otherwise? perhaps from tq_disk?
1011                                  */
1012
1013                                 /* for atari only */
1014                                 ide_release_lock();
1015                                 hwgroup->busy = 0;
1016                         }
1017
1018                         /* no more work for this hwgroup (for now) */
1019                         return;
1020                 }
1021         again:
1022                 hwif = HWIF(drive);
1023                 if (hwgroup->hwif->sharing_irq && hwif != hwgroup->hwif) {
1024                         /*
1025                          * set nIEN for previous hwif, drives in the
1026                          * quirk_list may not like intr setups/cleanups
1027                          */
1028                         if (drive->quirk_list != 1)
1029                                 hwif->tp_ops->set_irq(hwif, 0);
1030                 }
1031                 hwgroup->hwif = hwif;
1032                 hwgroup->drive = drive;
1033                 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
1034                 drive->service_start = jiffies;
1035
1036                 if (blk_queue_plugged(drive->queue)) {
1037                         printk(KERN_ERR "ide: huh? queue was plugged!\n");
1038                         break;
1039                 }
1040
1041                 /*
1042                  * we know that the queue isn't empty, but this can happen
1043                  * if the q->prep_rq_fn() decides to kill a request
1044                  */
1045                 rq = elv_next_request(drive->queue);
1046                 if (!rq) {
1047                         hwgroup->busy = 0;
1048                         break;
1049                 }
1050
1051                 /*
1052                  * Sanity: don't accept a request that isn't a PM request
1053                  * if we are currently power managed. This is very important as
1054                  * blk_stop_queue() doesn't prevent the elv_next_request()
1055                  * above to return us whatever is in the queue. Since we call
1056                  * ide_do_request() ourselves, we end up taking requests while
1057                  * the queue is blocked...
1058                  *
1059                  * We let requests forced at head of queue with ide-preempt
1060                  * though. I hope that doesn't happen too much, hopefully not
1061                  * unless the subdriver triggers such a thing in its own PM
1062                  * state machine.
1063                  *
1064                  * We count how many times we loop here to make sure we service
1065                  * all drives in the hwgroup without looping for ever
1066                  */
1067                 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
1068                     blk_pm_request(rq) == 0 &&
1069                     (rq->cmd_flags & REQ_PREEMPT) == 0) {
1070                         drive = drive->next ? drive->next : hwgroup->drive;
1071                         if (loops++ < 4 && !blk_queue_plugged(drive->queue))
1072                                 goto again;
1073                         /* We clear busy, there should be no pending ATA command at this point. */
1074                         hwgroup->busy = 0;
1075                         break;
1076                 }
1077
1078                 hwgroup->rq = rq;
1079
1080                 /*
1081                  * Some systems have trouble with IDE IRQs arriving while
1082                  * the driver is still setting things up.  So, here we disable
1083                  * the IRQ used by this interface while the request is being started.
1084                  * This may look bad at first, but pretty much the same thing
1085                  * happens anyway when any interrupt comes in, IDE or otherwise
1086                  *  -- the kernel masks the IRQ while it is being handled.
1087                  */
1088                 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1089                         disable_irq_nosync(hwif->irq);
1090                 spin_unlock(&ide_lock);
1091                 local_irq_enable_in_hardirq();
1092                         /* allow other IRQs while we start this request */
1093                 startstop = start_request(drive, rq);
1094                 spin_lock_irq(&ide_lock);
1095                 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1096                         enable_irq(hwif->irq);
1097                 if (startstop == ide_stopped)
1098                         hwgroup->busy = 0;
1099         }
1100 }
1101
1102 /*
1103  * Passes the stuff to ide_do_request
1104  */
1105 void do_ide_request(struct request_queue *q)
1106 {
1107         ide_drive_t *drive = q->queuedata;
1108
1109         ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1110 }
1111
1112 /*
1113  * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1114  * retry the current request in pio mode instead of risking tossing it
1115  * all away
1116  */
1117 static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1118 {
1119         ide_hwif_t *hwif = HWIF(drive);
1120         struct request *rq;
1121         ide_startstop_t ret = ide_stopped;
1122
1123         /*
1124          * end current dma transaction
1125          */
1126
1127         if (error < 0) {
1128                 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1129                 (void)hwif->dma_ops->dma_end(drive);
1130                 ret = ide_error(drive, "dma timeout error",
1131                                 hwif->tp_ops->read_status(hwif));
1132         } else {
1133                 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
1134                 hwif->dma_ops->dma_timeout(drive);
1135         }
1136
1137         /*
1138          * disable dma for now, but remember that we did so because of
1139          * a timeout -- we'll reenable after we finish this next request
1140          * (or rather the first chunk of it) in pio.
1141          */
1142         drive->dev_flags |= IDE_DFLAG_DMA_PIO_RETRY;
1143         drive->retry_pio++;
1144         ide_dma_off_quietly(drive);
1145
1146         /*
1147          * un-busy drive etc (hwgroup->busy is cleared on return) and
1148          * make sure request is sane
1149          */
1150         rq = HWGROUP(drive)->rq;
1151
1152         if (!rq)
1153                 goto out;
1154
1155         HWGROUP(drive)->rq = NULL;
1156
1157         rq->errors = 0;
1158
1159         if (!rq->bio)
1160                 goto out;
1161
1162         rq->sector = rq->bio->bi_sector;
1163         rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1164         rq->hard_cur_sectors = rq->current_nr_sectors;
1165         rq->buffer = bio_data(rq->bio);
1166 out:
1167         return ret;
1168 }
1169
1170 /**
1171  *      ide_timer_expiry        -       handle lack of an IDE interrupt
1172  *      @data: timer callback magic (hwgroup)
1173  *
1174  *      An IDE command has timed out before the expected drive return
1175  *      occurred. At this point we attempt to clean up the current
1176  *      mess. If the current handler includes an expiry handler then
1177  *      we invoke the expiry handler, and providing it is happy the
1178  *      work is done. If that fails we apply generic recovery rules
1179  *      invoking the handler and checking the drive DMA status. We
1180  *      have an excessively incestuous relationship with the DMA
1181  *      logic that wants cleaning up.
1182  */
1183
1184 void ide_timer_expiry (unsigned long data)
1185 {
1186         ide_hwgroup_t   *hwgroup = (ide_hwgroup_t *) data;
1187         ide_handler_t   *handler;
1188         ide_expiry_t    *expiry;
1189         unsigned long   flags;
1190         unsigned long   wait = -1;
1191
1192         spin_lock_irqsave(&ide_lock, flags);
1193
1194         if (((handler = hwgroup->handler) == NULL) ||
1195             (hwgroup->req_gen != hwgroup->req_gen_timer)) {
1196                 /*
1197                  * Either a marginal timeout occurred
1198                  * (got the interrupt just as timer expired),
1199                  * or we were "sleeping" to give other devices a chance.
1200                  * Either way, we don't really want to complain about anything.
1201                  */
1202                 if (hwgroup->sleeping) {
1203                         hwgroup->sleeping = 0;
1204                         hwgroup->busy = 0;
1205                 }
1206         } else {
1207                 ide_drive_t *drive = hwgroup->drive;
1208                 if (!drive) {
1209                         printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1210                         hwgroup->handler = NULL;
1211                 } else {
1212                         ide_hwif_t *hwif;
1213                         ide_startstop_t startstop = ide_stopped;
1214                         if (!hwgroup->busy) {
1215                                 hwgroup->busy = 1;      /* paranoia */
1216                                 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1217                         }
1218                         if ((expiry = hwgroup->expiry) != NULL) {
1219                                 /* continue */
1220                                 if ((wait = expiry(drive)) > 0) {
1221                                         /* reset timer */
1222                                         hwgroup->timer.expires  = jiffies + wait;
1223                                         hwgroup->req_gen_timer = hwgroup->req_gen;
1224                                         add_timer(&hwgroup->timer);
1225                                         spin_unlock_irqrestore(&ide_lock, flags);
1226                                         return;
1227                                 }
1228                         }
1229                         hwgroup->handler = NULL;
1230                         /*
1231                          * We need to simulate a real interrupt when invoking
1232                          * the handler() function, which means we need to
1233                          * globally mask the specific IRQ:
1234                          */
1235                         spin_unlock(&ide_lock);
1236                         hwif  = HWIF(drive);
1237                         /* disable_irq_nosync ?? */
1238                         disable_irq(hwif->irq);
1239                         /* local CPU only,
1240                          * as if we were handling an interrupt */
1241                         local_irq_disable();
1242                         if (hwgroup->polling) {
1243                                 startstop = handler(drive);
1244                         } else if (drive_is_ready(drive)) {
1245                                 if (drive->waiting_for_dma)
1246                                         hwif->dma_ops->dma_lost_irq(drive);
1247                                 (void)ide_ack_intr(hwif);
1248                                 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1249                                 startstop = handler(drive);
1250                         } else {
1251                                 if (drive->waiting_for_dma) {
1252                                         startstop = ide_dma_timeout_retry(drive, wait);
1253                                 } else
1254                                         startstop =
1255                                         ide_error(drive, "irq timeout",
1256                                                   hwif->tp_ops->read_status(hwif));
1257                         }
1258                         drive->service_time = jiffies - drive->service_start;
1259                         spin_lock_irq(&ide_lock);
1260                         enable_irq(hwif->irq);
1261                         if (startstop == ide_stopped)
1262                                 hwgroup->busy = 0;
1263                 }
1264         }
1265         ide_do_request(hwgroup, IDE_NO_IRQ);
1266         spin_unlock_irqrestore(&ide_lock, flags);
1267 }
1268
1269 /**
1270  *      unexpected_intr         -       handle an unexpected IDE interrupt
1271  *      @irq: interrupt line
1272  *      @hwgroup: hwgroup being processed
1273  *
1274  *      There's nothing really useful we can do with an unexpected interrupt,
1275  *      other than reading the status register (to clear it), and logging it.
1276  *      There should be no way that an irq can happen before we're ready for it,
1277  *      so we needn't worry much about losing an "important" interrupt here.
1278  *
1279  *      On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1280  *      the drive enters "idle", "standby", or "sleep" mode, so if the status
1281  *      looks "good", we just ignore the interrupt completely.
1282  *
1283  *      This routine assumes __cli() is in effect when called.
1284  *
1285  *      If an unexpected interrupt happens on irq15 while we are handling irq14
1286  *      and if the two interfaces are "serialized" (CMD640), then it looks like
1287  *      we could screw up by interfering with a new request being set up for
1288  *      irq15.
1289  *
1290  *      In reality, this is a non-issue.  The new command is not sent unless
1291  *      the drive is ready to accept one, in which case we know the drive is
1292  *      not trying to interrupt us.  And ide_set_handler() is always invoked
1293  *      before completing the issuance of any new drive command, so we will not
1294  *      be accidentally invoked as a result of any valid command completion
1295  *      interrupt.
1296  *
1297  *      Note that we must walk the entire hwgroup here. We know which hwif
1298  *      is doing the current command, but we don't know which hwif burped
1299  *      mysteriously.
1300  */
1301
1302 static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1303 {
1304         u8 stat;
1305         ide_hwif_t *hwif = hwgroup->hwif;
1306
1307         /*
1308          * handle the unexpected interrupt
1309          */
1310         do {
1311                 if (hwif->irq == irq) {
1312                         stat = hwif->tp_ops->read_status(hwif);
1313
1314                         if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
1315                                 /* Try to not flood the console with msgs */
1316                                 static unsigned long last_msgtime, count;
1317                                 ++count;
1318                                 if (time_after(jiffies, last_msgtime + HZ)) {
1319                                         last_msgtime = jiffies;
1320                                         printk(KERN_ERR "%s%s: unexpected interrupt, "
1321                                                 "status=0x%02x, count=%ld\n",
1322                                                 hwif->name,
1323                                                 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1324                                 }
1325                         }
1326                 }
1327         } while ((hwif = hwif->next) != hwgroup->hwif);
1328 }
1329
1330 /**
1331  *      ide_intr        -       default IDE interrupt handler
1332  *      @irq: interrupt number
1333  *      @dev_id: hwif group
1334  *      @regs: unused weirdness from the kernel irq layer
1335  *
1336  *      This is the default IRQ handler for the IDE layer. You should
1337  *      not need to override it. If you do be aware it is subtle in
1338  *      places
1339  *
1340  *      hwgroup->hwif is the interface in the group currently performing
1341  *      a command. hwgroup->drive is the drive and hwgroup->handler is
1342  *      the IRQ handler to call. As we issue a command the handlers
1343  *      step through multiple states, reassigning the handler to the
1344  *      next step in the process. Unlike a smart SCSI controller IDE
1345  *      expects the main processor to sequence the various transfer
1346  *      stages. We also manage a poll timer to catch up with most
1347  *      timeout situations. There are still a few where the handlers
1348  *      don't ever decide to give up.
1349  *
1350  *      The handler eventually returns ide_stopped to indicate the
1351  *      request completed. At this point we issue the next request
1352  *      on the hwgroup and the process begins again.
1353  */
1354
1355 irqreturn_t ide_intr (int irq, void *dev_id)
1356 {
1357         unsigned long flags;
1358         ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1359         ide_hwif_t *hwif;
1360         ide_drive_t *drive;
1361         ide_handler_t *handler;
1362         ide_startstop_t startstop;
1363
1364         spin_lock_irqsave(&ide_lock, flags);
1365         hwif = hwgroup->hwif;
1366
1367         if (!ide_ack_intr(hwif)) {
1368                 spin_unlock_irqrestore(&ide_lock, flags);
1369                 return IRQ_NONE;
1370         }
1371
1372         if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
1373                 /*
1374                  * Not expecting an interrupt from this drive.
1375                  * That means this could be:
1376                  *      (1) an interrupt from another PCI device
1377                  *      sharing the same PCI INT# as us.
1378                  * or   (2) a drive just entered sleep or standby mode,
1379                  *      and is interrupting to let us know.
1380                  * or   (3) a spurious interrupt of unknown origin.
1381                  *
1382                  * For PCI, we cannot tell the difference,
1383                  * so in that case we just ignore it and hope it goes away.
1384                  *
1385                  * FIXME: unexpected_intr should be hwif-> then we can
1386                  * remove all the ifdef PCI crap
1387                  */
1388 #ifdef CONFIG_BLK_DEV_IDEPCI
1389                 if (hwif->chipset != ide_pci)
1390 #endif  /* CONFIG_BLK_DEV_IDEPCI */
1391                 {
1392                         /*
1393                          * Probably not a shared PCI interrupt,
1394                          * so we can safely try to do something about it:
1395                          */
1396                         unexpected_intr(irq, hwgroup);
1397 #ifdef CONFIG_BLK_DEV_IDEPCI
1398                 } else {
1399                         /*
1400                          * Whack the status register, just in case
1401                          * we have a leftover pending IRQ.
1402                          */
1403                         (void)hwif->tp_ops->read_status(hwif);
1404 #endif /* CONFIG_BLK_DEV_IDEPCI */
1405                 }
1406                 spin_unlock_irqrestore(&ide_lock, flags);
1407                 return IRQ_NONE;
1408         }
1409         drive = hwgroup->drive;
1410         if (!drive) {
1411                 /*
1412                  * This should NEVER happen, and there isn't much
1413                  * we could do about it here.
1414                  *
1415                  * [Note - this can occur if the drive is hot unplugged]
1416                  */
1417                 spin_unlock_irqrestore(&ide_lock, flags);
1418                 return IRQ_HANDLED;
1419         }
1420         if (!drive_is_ready(drive)) {
1421                 /*
1422                  * This happens regularly when we share a PCI IRQ with
1423                  * another device.  Unfortunately, it can also happen
1424                  * with some buggy drives that trigger the IRQ before
1425                  * their status register is up to date.  Hopefully we have
1426                  * enough advance overhead that the latter isn't a problem.
1427                  */
1428                 spin_unlock_irqrestore(&ide_lock, flags);
1429                 return IRQ_NONE;
1430         }
1431         if (!hwgroup->busy) {
1432                 hwgroup->busy = 1;      /* paranoia */
1433                 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1434         }
1435         hwgroup->handler = NULL;
1436         hwgroup->req_gen++;
1437         del_timer(&hwgroup->timer);
1438         spin_unlock(&ide_lock);
1439
1440         if (hwif->port_ops && hwif->port_ops->clear_irq)
1441                 hwif->port_ops->clear_irq(drive);
1442
1443         if (drive->dev_flags & IDE_DFLAG_UNMASK)
1444                 local_irq_enable_in_hardirq();
1445
1446         /* service this interrupt, may set handler for next interrupt */
1447         startstop = handler(drive);
1448
1449         spin_lock_irq(&ide_lock);
1450         /*
1451          * Note that handler() may have set things up for another
1452          * interrupt to occur soon, but it cannot happen until
1453          * we exit from this routine, because it will be the
1454          * same irq as is currently being serviced here, and Linux
1455          * won't allow another of the same (on any CPU) until we return.
1456          */
1457         drive->service_time = jiffies - drive->service_start;
1458         if (startstop == ide_stopped) {
1459                 if (hwgroup->handler == NULL) { /* paranoia */
1460                         hwgroup->busy = 0;
1461                         ide_do_request(hwgroup, hwif->irq);
1462                 } else {
1463                         printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1464                                 "on exit\n", drive->name);
1465                 }
1466         }
1467         spin_unlock_irqrestore(&ide_lock, flags);
1468         return IRQ_HANDLED;
1469 }
1470
1471 /**
1472  *      ide_do_drive_cmd        -       issue IDE special command
1473  *      @drive: device to issue command
1474  *      @rq: request to issue
1475  *
1476  *      This function issues a special IDE device request
1477  *      onto the request queue.
1478  *
1479  *      the rq is queued at the head of the request queue, displacing
1480  *      the currently-being-processed request and this function
1481  *      returns immediately without waiting for the new rq to be
1482  *      completed.  This is VERY DANGEROUS, and is intended for
1483  *      careful use by the ATAPI tape/cdrom driver code.
1484  */
1485
1486 void ide_do_drive_cmd(ide_drive_t *drive, struct request *rq)
1487 {
1488         unsigned long flags;
1489         ide_hwgroup_t *hwgroup = HWGROUP(drive);
1490
1491         spin_lock_irqsave(&ide_lock, flags);
1492         hwgroup->rq = NULL;
1493         __elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 0);
1494         blk_start_queueing(drive->queue);
1495         spin_unlock_irqrestore(&ide_lock, flags);
1496 }
1497
1498 EXPORT_SYMBOL(ide_do_drive_cmd);
1499
1500 void ide_pktcmd_tf_load(ide_drive_t *drive, u32 tf_flags, u16 bcount, u8 dma)
1501 {
1502         ide_hwif_t *hwif = drive->hwif;
1503         ide_task_t task;
1504
1505         memset(&task, 0, sizeof(task));
1506         task.tf_flags = IDE_TFLAG_OUT_LBAH | IDE_TFLAG_OUT_LBAM |
1507                         IDE_TFLAG_OUT_FEATURE | tf_flags;
1508         task.tf.feature = dma;          /* Use PIO/DMA */
1509         task.tf.lbam    = bcount & 0xff;
1510         task.tf.lbah    = (bcount >> 8) & 0xff;
1511
1512         ide_tf_dump(drive->name, &task.tf);
1513         hwif->tp_ops->set_irq(hwif, 1);
1514         SELECT_MASK(drive, 0);
1515         hwif->tp_ops->tf_load(drive, &task);
1516 }
1517
1518 EXPORT_SYMBOL_GPL(ide_pktcmd_tf_load);
1519
1520 void ide_pad_transfer(ide_drive_t *drive, int write, int len)
1521 {
1522         ide_hwif_t *hwif = drive->hwif;
1523         u8 buf[4] = { 0 };
1524
1525         while (len > 0) {
1526                 if (write)
1527                         hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
1528                 else
1529                         hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
1530                 len -= 4;
1531         }
1532 }
1533 EXPORT_SYMBOL_GPL(ide_pad_transfer);