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/completion.h>
  44 #include <linux/reboot.h>
  45 #include <linux/cdrom.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/device.h>
  48 #include <linux/kmod.h>
  49 #include <linux/scatterlist.h>
  50
  51 #include <asm/byteorder.h>
  52 #include <asm/irq.h>
  53 #include <asm/uaccess.h>
  54 #include <asm/io.h>
  55 #include <asm/bitops.h>
  56
  57 static int __ide_end_request(ide_drive_t *drive, struct request *rq,
  58                              int uptodate, int nr_sectors)
  59 {
  60         int ret = 1;
  61
  62         /*
  63          * if failfast is set on a request, override number of sectors and
  64          * complete the whole request right now
  65          */
  66         if (blk_noretry_request(rq) && end_io_error(uptodate))
  67                 nr_sectors = rq->hard_nr_sectors;
  68
  69         if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
  70                 rq->errors = -EIO;
  71
  72         /*
  73          * decide whether to reenable DMA -- 3 is a random magic for now,
  74          * if we DMA timeout more than 3 times, just stay in PIO
  75          */
  76         if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
  77                 drive->state = 0;
  78                 HWGROUP(drive)->hwif->ide_dma_on(drive);
  79         }
  80
  81         if (!end_that_request_first(rq, uptodate, nr_sectors)) {
  82                 add_disk_randomness(rq->rq_disk);
  83                 if (!list_empty(&rq->queuelist))
  84                         blkdev_dequeue_request(rq);
  85                 HWGROUP(drive)->rq = NULL;
  86                 end_that_request_last(rq, uptodate);
  87                 ret = 0;
  88         }
  89
  90         return ret;
  91 }
  92
  93 /**
  94  *      ide_end_request         -       complete an IDE I/O
  95  *      @drive: IDE device for the I/O
  96  *      @uptodate:
  97  *      @nr_sectors: number of sectors completed
  98  *
  99  *      This is our end_request wrapper function. We complete the I/O
 100  *      update random number input and dequeue the request, which if
 101  *      it was tagged may be out of order.
 102  */
 103
 104 int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
 105 {
 106         struct request *rq;
 107         unsigned long flags;
 108         int ret = 1;
 109
 110         /*
 111          * room for locking improvements here, the calls below don't
 112          * need the queue lock held at all
 113          */
 114         spin_lock_irqsave(&ide_lock, flags);
 115         rq = HWGROUP(drive)->rq;
 116
 117         if (!nr_sectors)
 118                 nr_sectors = rq->hard_cur_sectors;
 119
 120         ret = __ide_end_request(drive, rq, uptodate, nr_sectors);
 121
 122         spin_unlock_irqrestore(&ide_lock, flags);
 123         return ret;
 124 }
 125 EXPORT_SYMBOL(ide_end_request);
 126
 127 /*
 128  * Power Management state machine. This one is rather trivial for now,
 129  * we should probably add more, like switching back to PIO on suspend
 130  * to help some BIOSes, re-do the door locking on resume, etc...
 131  */
 132
 133 enum {
 134         ide_pm_flush_cache      = ide_pm_state_start_suspend,
 135         idedisk_pm_standby,
 136
 137         idedisk_pm_restore_pio  = ide_pm_state_start_resume,
 138         idedisk_pm_idle,
 139         ide_pm_restore_dma,
 140 };
 141
 142 static void ide_complete_power_step(ide_drive_t *drive, struct request *rq, u8 stat, u8 error)
 143 {
 144         struct request_pm_state *pm = rq->data;
 145
 146         if (drive->media != ide_disk)
 147                 return;
 148
 149         switch (pm->pm_step) {
 150         case ide_pm_flush_cache:        /* Suspend step 1 (flush cache) complete */
 151                 if (pm->pm_state == PM_EVENT_FREEZE)
 152                         pm->pm_step = ide_pm_state_completed;
 153                 else
 154                         pm->pm_step = idedisk_pm_standby;
 155                 break;
 156         case idedisk_pm_standby:        /* Suspend step 2 (standby) complete */
 157                 pm->pm_step = ide_pm_state_completed;
 158                 break;
 159         case idedisk_pm_restore_pio:    /* Resume step 1 complete */
 160                 pm->pm_step = idedisk_pm_idle;
 161                 break;
 162         case idedisk_pm_idle:           /* Resume step 2 (idle) complete */
 163                 pm->pm_step = ide_pm_restore_dma;
 164                 break;
 165         }
 166 }
 167
 168 static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
 169 {
 170         struct request_pm_state *pm = rq->data;
 171         ide_task_t *args = rq->special;
 172
 173         memset(args, 0, sizeof(*args));
 174
 175         switch (pm->pm_step) {
 176         case ide_pm_flush_cache:        /* Suspend step 1 (flush cache) */
 177                 if (drive->media != ide_disk)
 178                         break;
 179                 /* Not supported? Switch to next step now. */
 180                 if (!drive->wcache || !ide_id_has_flush_cache(drive->id)) {
 181                         ide_complete_power_step(drive, rq, 0, 0);
 182                         return ide_stopped;
 183                 }
 184                 if (ide_id_has_flush_cache_ext(drive->id))
 185                         args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE_EXT;
 186                 else
 187                         args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE;
 188                 args->command_type = IDE_DRIVE_TASK_NO_DATA;
 189                 args->handler      = &task_no_data_intr;
 190                 return do_rw_taskfile(drive, args);
 191
 192         case idedisk_pm_standby:        /* Suspend step 2 (standby) */
 193                 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_STANDBYNOW1;
 194                 args->command_type = IDE_DRIVE_TASK_NO_DATA;
 195                 args->handler      = &task_no_data_intr;
 196                 return do_rw_taskfile(drive, args);
 197
 198         case idedisk_pm_restore_pio:    /* Resume step 1 (restore PIO) */
 199                 if (drive->hwif->tuneproc != NULL)
 200                         drive->hwif->tuneproc(drive, 255);
 201                 /*
 202                  * skip idedisk_pm_idle for ATAPI devices
 203                  */
 204                 if (drive->media != ide_disk)
 205                         pm->pm_step = ide_pm_restore_dma;
 206                 else
 207                         ide_complete_power_step(drive, rq, 0, 0);
 208                 return ide_stopped;
 209
 210         case idedisk_pm_idle:           /* Resume step 2 (idle) */
 211                 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_IDLEIMMEDIATE;
 212                 args->command_type = IDE_DRIVE_TASK_NO_DATA;
 213                 args->handler = task_no_data_intr;
 214                 return do_rw_taskfile(drive, args);
 215
 216         case ide_pm_restore_dma:        /* Resume step 3 (restore DMA) */
 217                 /*
 218                  * Right now, all we do is call hwif->ide_dma_check(drive),
 219                  * we could be smarter and check for current xfer_speed
 220                  * in struct drive etc...
 221                  */
 222                 if ((drive->id->capability & 1) == 0)
 223                         break;
 224                 if (drive->hwif->ide_dma_check == NULL)
 225                         break;
 226                 drive->hwif->dma_off_quietly(drive);
 227                 ide_set_dma(drive);
 228                 break;
 229         }
 230         pm->pm_step = ide_pm_state_completed;
 231         return ide_stopped;
 232 }
 233
 234 /**
 235  *      ide_end_dequeued_request        -       complete an IDE I/O
 236  *      @drive: IDE device for the I/O
 237  *      @uptodate:
 238  *      @nr_sectors: number of sectors completed
 239  *
 240  *      Complete an I/O that is no longer on the request queue. This
 241  *      typically occurs when we pull the request and issue a REQUEST_SENSE.
 242  *      We must still finish the old request but we must not tamper with the
 243  *      queue in the meantime.
 244  *
 245  *      NOTE: This path does not handle barrier, but barrier is not supported
 246  *      on ide-cd anyway.
 247  */
 248
 249 int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
 250                              int uptodate, int nr_sectors)
 251 {
 252         unsigned long flags;
 253         int ret = 1;
 254
 255         spin_lock_irqsave(&ide_lock, flags);
 256
 257         BUG_ON(!blk_rq_started(rq));
 258
 259         /*
 260          * if failfast is set on a request, override number of sectors and
 261          * complete the whole request right now
 262          */
 263         if (blk_noretry_request(rq) && end_io_error(uptodate))
 264                 nr_sectors = rq->hard_nr_sectors;
 265
 266         if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
 267                 rq->errors = -EIO;
 268
 269         /*
 270          * decide whether to reenable DMA -- 3 is a random magic for now,
 271          * if we DMA timeout more than 3 times, just stay in PIO
 272          */
 273         if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
 274                 drive->state = 0;
 275                 HWGROUP(drive)->hwif->ide_dma_on(drive);
 276         }
 277
 278         if (!end_that_request_first(rq, uptodate, nr_sectors)) {
 279                 add_disk_randomness(rq->rq_disk);
 280                 if (blk_rq_tagged(rq))
 281                         blk_queue_end_tag(drive->queue, rq);
 282                 end_that_request_last(rq, uptodate);
 283                 ret = 0;
 284         }
 285         spin_unlock_irqrestore(&ide_lock, flags);
 286         return ret;
 287 }
 288 EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
 289
 290
 291 /**
 292  *      ide_complete_pm_request - end the current Power Management request
 293  *      @drive: target drive
 294  *      @rq: request
 295  *
 296  *      This function cleans up the current PM request and stops the queue
 297  *      if necessary.
 298  */
 299 static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
 300 {
 301         unsigned long flags;
 302
 303 #ifdef DEBUG_PM
 304         printk("%s: completing PM request, %s\n", drive->name,
 305                blk_pm_suspend_request(rq) ? "suspend" : "resume");
 306 #endif
 307         spin_lock_irqsave(&ide_lock, flags);
 308         if (blk_pm_suspend_request(rq)) {
 309                 blk_stop_queue(drive->queue);
 310         } else {
 311                 drive->blocked = 0;
 312                 blk_start_queue(drive->queue);
 313         }
 314         blkdev_dequeue_request(rq);
 315         HWGROUP(drive)->rq = NULL;
 316         end_that_request_last(rq, 1);
 317         spin_unlock_irqrestore(&ide_lock, flags);
 318 }
 319
 320 /*
 321  * FIXME: probably move this somewhere else, name is bad too :)
 322  */
 323 u64 ide_get_error_location(ide_drive_t *drive, char *args)
 324 {
 325         u32 high, low;
 326         u8 hcyl, lcyl, sect;
 327         u64 sector;
 328
 329         high = 0;
 330         hcyl = args[5];
 331         lcyl = args[4];
 332         sect = args[3];
 333
 334         if (ide_id_has_flush_cache_ext(drive->id)) {
 335                 low = (hcyl << 16) | (lcyl << 8) | sect;
 336                 HWIF(drive)->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
 337                 high = ide_read_24(drive);
 338         } else {
 339                 u8 cur = HWIF(drive)->INB(IDE_SELECT_REG);
 340                 if (cur & 0x40) {
 341                         high = cur & 0xf;
 342                         low = (hcyl << 16) | (lcyl << 8) | sect;
 343                 } else {
 344                         low = hcyl * drive->head * drive->sect;
 345                         low += lcyl * drive->sect;
 346                         low += sect - 1;
 347                 }
 348         }
 349
 350         sector = ((u64) high << 24) | low;
 351         return sector;
 352 }
 353 EXPORT_SYMBOL(ide_get_error_location);
 354
 355 /**
 356  *      ide_end_drive_cmd       -       end an explicit drive command
 357  *      @drive: command
 358  *      @stat: status bits
 359  *      @err: error bits
 360  *
 361  *      Clean up after success/failure of an explicit drive command.
 362  *      These get thrown onto the queue so they are synchronized with
 363  *      real I/O operations on the drive.
 364  *
 365  *      In LBA48 mode we have to read the register set twice to get
 366  *      all the extra information out.
 367  */
 368
 369 void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
 370 {
 371         ide_hwif_t *hwif = HWIF(drive);
 372         unsigned long flags;
 373         struct request *rq;
 374
 375         spin_lock_irqsave(&ide_lock, flags);
 376         rq = HWGROUP(drive)->rq;
 377         spin_unlock_irqrestore(&ide_lock, flags);
 378
 379         if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
 380                 u8 *args = (u8 *) rq->buffer;
 381                 if (rq->errors == 0)
 382                         rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
 383
 384                 if (args) {
 385                         args[0] = stat;
 386                         args[1] = err;
 387                         args[2] = hwif->INB(IDE_NSECTOR_REG);
 388                 }
 389         } else if (rq->cmd_type == REQ_TYPE_ATA_TASK) {
 390                 u8 *args = (u8 *) rq->buffer;
 391                 if (rq->errors == 0)
 392                         rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
 393
 394                 if (args) {
 395                         args[0] = stat;
 396                         args[1] = err;
 397                         args[2] = hwif->INB(IDE_NSECTOR_REG);
 398                         args[3] = hwif->INB(IDE_SECTOR_REG);
 399                         args[4] = hwif->INB(IDE_LCYL_REG);
 400                         args[5] = hwif->INB(IDE_HCYL_REG);
 401                         args[6] = hwif->INB(IDE_SELECT_REG);
 402                 }
 403         } else if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
 404                 ide_task_t *args = (ide_task_t *) rq->special;
 405                 if (rq->errors == 0)
 406                         rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
 407
 408                 if (args) {
 409                         if (args->tf_in_flags.b.data) {
 410                                 u16 data                                = hwif->INW(IDE_DATA_REG);
 411                                 args->tfRegister[IDE_DATA_OFFSET]       = (data) & 0xFF;
 412                                 args->hobRegister[IDE_DATA_OFFSET]      = (data >> 8) & 0xFF;
 413                         }
 414                         args->tfRegister[IDE_ERROR_OFFSET]   = err;
 415                         /* be sure we're looking at the low order bits */
 416                         hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
 417                         args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
 418                         args->tfRegister[IDE_SECTOR_OFFSET]  = hwif->INB(IDE_SECTOR_REG);
 419                         args->tfRegister[IDE_LCYL_OFFSET]    = hwif->INB(IDE_LCYL_REG);
 420                         args->tfRegister[IDE_HCYL_OFFSET]    = hwif->INB(IDE_HCYL_REG);
 421                         args->tfRegister[IDE_SELECT_OFFSET]  = hwif->INB(IDE_SELECT_REG);
 422                         args->tfRegister[IDE_STATUS_OFFSET]  = stat;
 423
 424                         if (drive->addressing == 1) {
 425                                 hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
 426                                 args->hobRegister[IDE_FEATURE_OFFSET]   = hwif->INB(IDE_FEATURE_REG);
 427                                 args->hobRegister[IDE_NSECTOR_OFFSET]   = hwif->INB(IDE_NSECTOR_REG);
 428                                 args->hobRegister[IDE_SECTOR_OFFSET]    = hwif->INB(IDE_SECTOR_REG);
 429                                 args->hobRegister[IDE_LCYL_OFFSET]      = hwif->INB(IDE_LCYL_REG);
 430                                 args->hobRegister[IDE_HCYL_OFFSET]      = hwif->INB(IDE_HCYL_REG);
 431                         }
 432                 }
 433         } else if (blk_pm_request(rq)) {
 434                 struct request_pm_state *pm = rq->data;
 435 #ifdef DEBUG_PM
 436                 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
 437                         drive->name, rq->pm->pm_step, stat, err);
 438 #endif
 439                 ide_complete_power_step(drive, rq, stat, err);
 440                 if (pm->pm_step == ide_pm_state_completed)
 441                         ide_complete_pm_request(drive, rq);
 442                 return;
 443         }
 444
 445         spin_lock_irqsave(&ide_lock, flags);
 446         blkdev_dequeue_request(rq);
 447         HWGROUP(drive)->rq = NULL;
 448         rq->errors = err;
 449         end_that_request_last(rq, !rq->errors);
 450         spin_unlock_irqrestore(&ide_lock, flags);
 451 }
 452
 453 EXPORT_SYMBOL(ide_end_drive_cmd);
 454
 455 /**
 456  *      try_to_flush_leftover_data      -       flush junk
 457  *      @drive: drive to flush
 458  *
 459  *      try_to_flush_leftover_data() is invoked in response to a drive
 460  *      unexpectedly having its DRQ_STAT bit set.  As an alternative to
 461  *      resetting the drive, this routine tries to clear the condition
 462  *      by read a sector's worth of data from the drive.  Of course,
 463  *      this may not help if the drive is *waiting* for data from *us*.
 464  */
 465 static void try_to_flush_leftover_data (ide_drive_t *drive)
 466 {
 467         int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
 468
 469         if (drive->media != ide_disk)
 470                 return;
 471         while (i > 0) {
 472                 u32 buffer[16];
 473                 u32 wcount = (i > 16) ? 16 : i;
 474
 475                 i -= wcount;
 476                 HWIF(drive)->ata_input_data(drive, buffer, wcount);
 477         }
 478 }
 479
 480 static void ide_kill_rq(ide_drive_t *drive, struct request *rq)
 481 {
 482         if (rq->rq_disk) {
 483                 ide_driver_t *drv;
 484
 485                 drv = *(ide_driver_t **)rq->rq_disk->private_data;
 486                 drv->end_request(drive, 0, 0);
 487         } else
 488                 ide_end_request(drive, 0, 0);
 489 }
 490
 491 static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
 492 {
 493         ide_hwif_t *hwif = drive->hwif;
 494
 495         if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
 496                 /* other bits are useless when BUSY */
 497                 rq->errors |= ERROR_RESET;
 498         } else if (stat & ERR_STAT) {
 499                 /* err has different meaning on cdrom and tape */
 500                 if (err == ABRT_ERR) {
 501                         if (drive->select.b.lba &&
 502                             /* some newer drives don't support WIN_SPECIFY */
 503                             hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY)
 504                                 return ide_stopped;
 505                 } else if ((err & BAD_CRC) == BAD_CRC) {
 506                         /* UDMA crc error, just retry the operation */
 507                         drive->crc_count++;
 508                 } else if (err & (BBD_ERR | ECC_ERR)) {
 509                         /* retries won't help these */
 510                         rq->errors = ERROR_MAX;
 511                 } else if (err & TRK0_ERR) {
 512                         /* help it find track zero */
 513                         rq->errors |= ERROR_RECAL;
 514                 }
 515         }
 516
 517         if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ && hwif->err_stops_fifo == 0)
 518                 try_to_flush_leftover_data(drive);
 519
 520         if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) {
 521                 ide_kill_rq(drive, rq);
 522                 return ide_stopped;
 523         }
 524
 525         if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
 526                 rq->errors |= ERROR_RESET;
 527
 528         if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
 529                 ++rq->errors;
 530                 return ide_do_reset(drive);
 531         }
 532
 533         if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
 534                 drive->special.b.recalibrate = 1;
 535
 536         ++rq->errors;
 537
 538         return ide_stopped;
 539 }
 540
 541 static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
 542 {
 543         ide_hwif_t *hwif = drive->hwif;
 544
 545         if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
 546                 /* other bits are useless when BUSY */
 547                 rq->errors |= ERROR_RESET;
 548         } else {
 549                 /* add decoding error stuff */
 550         }
 551
 552         if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
 553                 /* force an abort */
 554                 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
 555
 556         if (rq->errors >= ERROR_MAX) {
 557                 ide_kill_rq(drive, rq);
 558         } else {
 559                 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
 560                         ++rq->errors;
 561                         return ide_do_reset(drive);
 562                 }
 563                 ++rq->errors;
 564         }
 565
 566         return ide_stopped;
 567 }
 568
 569 ide_startstop_t
 570 __ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
 571 {
 572         if (drive->media == ide_disk)
 573                 return ide_ata_error(drive, rq, stat, err);
 574         return ide_atapi_error(drive, rq, stat, err);
 575 }
 576
 577 EXPORT_SYMBOL_GPL(__ide_error);
 578
 579 /**
 580  *      ide_error       -       handle an error on the IDE
 581  *      @drive: drive the error occurred on
 582  *      @msg: message to report
 583  *      @stat: status bits
 584  *
 585  *      ide_error() takes action based on the error returned by the drive.
 586  *      For normal I/O that may well include retries. We deal with
 587  *      both new-style (taskfile) and old style command handling here.
 588  *      In the case of taskfile command handling there is work left to
 589  *      do
 590  */
 591
 592 ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
 593 {
 594         struct request *rq;
 595         u8 err;
 596
 597         err = ide_dump_status(drive, msg, stat);
 598
 599         if ((rq = HWGROUP(drive)->rq) == NULL)
 600                 return ide_stopped;
 601
 602         /* retry only "normal" I/O: */
 603         if (!blk_fs_request(rq)) {
 604                 rq->errors = 1;
 605                 ide_end_drive_cmd(drive, stat, err);
 606                 return ide_stopped;
 607         }
 608
 609         if (rq->rq_disk) {
 610                 ide_driver_t *drv;
 611
 612                 drv = *(ide_driver_t **)rq->rq_disk->private_data;
 613                 return drv->error(drive, rq, stat, err);
 614         } else
 615                 return __ide_error(drive, rq, stat, err);
 616 }
 617
 618 EXPORT_SYMBOL_GPL(ide_error);
 619
 620 ide_startstop_t __ide_abort(ide_drive_t *drive, struct request *rq)
 621 {
 622         if (drive->media != ide_disk)
 623                 rq->errors |= ERROR_RESET;
 624
 625         ide_kill_rq(drive, rq);
 626
 627         return ide_stopped;
 628 }
 629
 630 EXPORT_SYMBOL_GPL(__ide_abort);
 631
 632 /**
 633  *      ide_abort       -       abort pending IDE operations
 634  *      @drive: drive the error occurred on
 635  *      @msg: message to report
 636  *
 637  *      ide_abort kills and cleans up when we are about to do a
 638  *      host initiated reset on active commands. Longer term we
 639  *      want handlers to have sensible abort handling themselves
 640  *
 641  *      This differs fundamentally from ide_error because in
 642  *      this case the command is doing just fine when we
 643  *      blow it away.
 644  */
 645
 646 ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
 647 {
 648         struct request *rq;
 649
 650         if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
 651                 return ide_stopped;
 652
 653         /* retry only "normal" I/O: */
 654         if (!blk_fs_request(rq)) {
 655                 rq->errors = 1;
 656                 ide_end_drive_cmd(drive, BUSY_STAT, 0);
 657                 return ide_stopped;
 658         }
 659
 660         if (rq->rq_disk) {
 661                 ide_driver_t *drv;
 662
 663                 drv = *(ide_driver_t **)rq->rq_disk->private_data;
 664                 return drv->abort(drive, rq);
 665         } else
 666                 return __ide_abort(drive, rq);
 667 }
 668
 669 /**
 670  *      ide_cmd         -       issue a simple drive command
 671  *      @drive: drive the command is for
 672  *      @cmd: command byte
 673  *      @nsect: sector byte
 674  *      @handler: handler for the command completion
 675  *
 676  *      Issue a simple drive command with interrupts.
 677  *      The drive must be selected beforehand.
 678  */
 679
 680 static void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect,
 681                 ide_handler_t *handler)
 682 {
 683         ide_hwif_t *hwif = HWIF(drive);
 684         if (IDE_CONTROL_REG)
 685                 hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */
 686         SELECT_MASK(drive,0);
 687         hwif->OUTB(nsect,IDE_NSECTOR_REG);
 688         ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
 689 }
 690
 691 /**
 692  *      drive_cmd_intr          -       drive command completion interrupt
 693  *      @drive: drive the completion interrupt occurred on
 694  *
 695  *      drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
 696  *      We do any necessary data reading and then wait for the drive to
 697  *      go non busy. At that point we may read the error data and complete
 698  *      the request
 699  */
 700
 701 static ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
 702 {
 703         struct request *rq = HWGROUP(drive)->rq;
 704         ide_hwif_t *hwif = HWIF(drive);
 705         u8 *args = (u8 *) rq->buffer;
 706         u8 stat = hwif->INB(IDE_STATUS_REG);
 707         int retries = 10;
 708
 709         local_irq_enable_in_hardirq();
 710         if ((stat & DRQ_STAT) && args && args[3]) {
 711                 u8 io_32bit = drive->io_32bit;
 712                 drive->io_32bit = 0;
 713                 hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
 714                 drive->io_32bit = io_32bit;
 715                 while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
 716                         udelay(100);
 717         }
 718
 719         if (!OK_STAT(stat, READY_STAT, BAD_STAT))
 720                 return ide_error(drive, "drive_cmd", stat);
 721                 /* calls ide_end_drive_cmd */
 722         ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
 723         return ide_stopped;
 724 }
 725
 726 static void ide_init_specify_cmd(ide_drive_t *drive, ide_task_t *task)
 727 {
 728         task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
 729         task->tfRegister[IDE_SECTOR_OFFSET]  = drive->sect;
 730         task->tfRegister[IDE_LCYL_OFFSET]    = drive->cyl;
 731         task->tfRegister[IDE_HCYL_OFFSET]    = drive->cyl>>8;
 732         task->tfRegister[IDE_SELECT_OFFSET]  = ((drive->head-1)|drive->select.all)&0xBF;
 733         task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SPECIFY;
 734
 735         task->handler = &set_geometry_intr;
 736 }
 737
 738 static void ide_init_restore_cmd(ide_drive_t *drive, ide_task_t *task)
 739 {
 740         task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
 741         task->tfRegister[IDE_COMMAND_OFFSET] = WIN_RESTORE;
 742
 743         task->handler = &recal_intr;
 744 }
 745
 746 static void ide_init_setmult_cmd(ide_drive_t *drive, ide_task_t *task)
 747 {
 748         task->tfRegister[IDE_NSECTOR_OFFSET] = drive->mult_req;
 749         task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SETMULT;
 750
 751         task->handler = &set_multmode_intr;
 752 }
 753
 754 static ide_startstop_t ide_disk_special(ide_drive_t *drive)
 755 {
 756         special_t *s = &drive->special;
 757         ide_task_t args;
 758
 759         memset(&args, 0, sizeof(ide_task_t));
 760         args.command_type = IDE_DRIVE_TASK_NO_DATA;
 761
 762         if (s->b.set_geometry) {
 763                 s->b.set_geometry = 0;
 764                 ide_init_specify_cmd(drive, &args);
 765         } else if (s->b.recalibrate) {
 766                 s->b.recalibrate = 0;
 767                 ide_init_restore_cmd(drive, &args);
 768         } else if (s->b.set_multmode) {
 769                 s->b.set_multmode = 0;
 770                 if (drive->mult_req > drive->id->max_multsect)
 771                         drive->mult_req = drive->id->max_multsect;
 772                 ide_init_setmult_cmd(drive, &args);
 773         } else if (s->all) {
 774                 int special = s->all;
 775                 s->all = 0;
 776                 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
 777                 return ide_stopped;
 778         }
 779
 780         do_rw_taskfile(drive, &args);
 781
 782         return ide_started;
 783 }
 784
 785 /**
 786  *      do_special              -       issue some special commands
 787  *      @drive: drive the command is for
 788  *
 789  *      do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
 790  *      commands to a drive.  It used to do much more, but has been scaled
 791  *      back.
 792  */
 793
 794 static ide_startstop_t do_special (ide_drive_t *drive)
 795 {
 796         special_t *s = &drive->special;
 797
 798 #ifdef DEBUG
 799         printk("%s: do_special: 0x%02x\n", drive->name, s->all);
 800 #endif
 801         if (s->b.set_tune) {
 802                 s->b.set_tune = 0;
 803                 if (HWIF(drive)->tuneproc != NULL)
 804                         HWIF(drive)->tuneproc(drive, drive->tune_req);
 805                 return ide_stopped;
 806         } else {
 807                 if (drive->media == ide_disk)
 808                         return ide_disk_special(drive);
 809
 810                 s->all = 0;
 811                 drive->mult_req = 0;
 812                 return ide_stopped;
 813         }
 814 }
 815
 816 void ide_map_sg(ide_drive_t *drive, struct request *rq)
 817 {
 818         ide_hwif_t *hwif = drive->hwif;
 819         struct scatterlist *sg = hwif->sg_table;
 820
 821         if (hwif->sg_mapped)    /* needed by ide-scsi */
 822                 return;
 823
 824         if (rq->cmd_type != REQ_TYPE_ATA_TASKFILE) {
 825                 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
 826         } else {
 827                 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
 828                 hwif->sg_nents = 1;
 829         }
 830 }
 831
 832 EXPORT_SYMBOL_GPL(ide_map_sg);
 833
 834 void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
 835 {
 836         ide_hwif_t *hwif = drive->hwif;
 837
 838         hwif->nsect = hwif->nleft = rq->nr_sectors;
 839         hwif->cursg = hwif->cursg_ofs = 0;
 840 }
 841
 842 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
 843
 844 /**
 845  *      execute_drive_command   -       issue special drive command
 846  *      @drive: the drive to issue the command on
 847  *      @rq: the request structure holding the command
 848  *
 849  *      execute_drive_cmd() issues a special drive command,  usually
 850  *      initiated by ioctl() from the external hdparm program. The
 851  *      command can be a drive command, drive task or taskfile
 852  *      operation. Weirdly you can call it with NULL to wait for
 853  *      all commands to finish. Don't do this as that is due to change
 854  */
 855
 856 static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
 857                 struct request *rq)
 858 {
 859         ide_hwif_t *hwif = HWIF(drive);
 860         if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
 861                 ide_task_t *args = rq->special;
 862
 863                 if (!args)
 864                         goto done;
 865
 866                 hwif->data_phase = args->data_phase;
 867
 868                 switch (hwif->data_phase) {
 869                 case TASKFILE_MULTI_OUT:
 870                 case TASKFILE_OUT:
 871                 case TASKFILE_MULTI_IN:
 872                 case TASKFILE_IN:
 873                         ide_init_sg_cmd(drive, rq);
 874                         ide_map_sg(drive, rq);
 875                 default:
 876                         break;
 877                 }
 878
 879                 if (args->tf_out_flags.all != 0)
 880                         return flagged_taskfile(drive, args);
 881                 return do_rw_taskfile(drive, args);
 882         } else if (rq->cmd_type == REQ_TYPE_ATA_TASK) {
 883                 u8 *args = rq->buffer;
 884                 u8 sel;
 885
 886                 if (!args)
 887                         goto done;
 888 #ifdef DEBUG
 889                 printk("%s: DRIVE_TASK_CMD ", drive->name);
 890                 printk("cmd=0x%02x ", args[0]);
 891                 printk("fr=0x%02x ", args[1]);
 892                 printk("ns=0x%02x ", args[2]);
 893                 printk("sc=0x%02x ", args[3]);
 894                 printk("lcyl=0x%02x ", args[4]);
 895                 printk("hcyl=0x%02x ", args[5]);
 896                 printk("sel=0x%02x\n", args[6]);
 897 #endif
 898                 hwif->OUTB(args[1], IDE_FEATURE_REG);
 899                 hwif->OUTB(args[3], IDE_SECTOR_REG);
 900                 hwif->OUTB(args[4], IDE_LCYL_REG);
 901                 hwif->OUTB(args[5], IDE_HCYL_REG);
 902                 sel = (args[6] & ~0x10);
 903                 if (drive->select.b.unit)
 904                         sel |= 0x10;
 905                 hwif->OUTB(sel, IDE_SELECT_REG);
 906                 ide_cmd(drive, args[0], args[2], &drive_cmd_intr);
 907                 return ide_started;
 908         } else if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
 909                 u8 *args = rq->buffer;
 910
 911                 if (!args)
 912                         goto done;
 913 #ifdef DEBUG
 914                 printk("%s: DRIVE_CMD ", drive->name);
 915                 printk("cmd=0x%02x ", args[0]);
 916                 printk("sc=0x%02x ", args[1]);
 917                 printk("fr=0x%02x ", args[2]);
 918                 printk("xx=0x%02x\n", args[3]);
 919 #endif
 920                 if (args[0] == WIN_SMART) {
 921                         hwif->OUTB(0x4f, IDE_LCYL_REG);
 922                         hwif->OUTB(0xc2, IDE_HCYL_REG);
 923                         hwif->OUTB(args[2],IDE_FEATURE_REG);
 924                         hwif->OUTB(args[1],IDE_SECTOR_REG);
 925                         ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
 926                         return ide_started;
 927                 }
 928                 hwif->OUTB(args[2],IDE_FEATURE_REG);
 929                 ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
 930                 return ide_started;
 931         }
 932
 933 done:
 934         /*
 935          * NULL is actually a valid way of waiting for
 936          * all current requests to be flushed from the queue.
 937          */
 938 #ifdef DEBUG
 939         printk("%s: DRIVE_CMD (null)\n", drive->name);
 940 #endif
 941         ide_end_drive_cmd(drive,
 942                         hwif->INB(IDE_STATUS_REG),
 943                         hwif->INB(IDE_ERROR_REG));
 944         return ide_stopped;
 945 }
 946
 947 static void ide_check_pm_state(ide_drive_t *drive, struct request *rq)
 948 {
 949         struct request_pm_state *pm = rq->data;
 950
 951         if (blk_pm_suspend_request(rq) &&
 952             pm->pm_step == ide_pm_state_start_suspend)
 953                 /* Mark drive blocked when starting the suspend sequence. */
 954                 drive->blocked = 1;
 955         else if (blk_pm_resume_request(rq) &&
 956                  pm->pm_step == ide_pm_state_start_resume) {
 957                 /*
 958                  * The first thing we do on wakeup is to wait for BSY bit to
 959                  * go away (with a looong timeout) as a drive on this hwif may
 960                  * just be POSTing itself.
 961                  * We do that before even selecting as the "other" device on
 962                  * the bus may be broken enough to walk on our toes at this
 963                  * point.
 964                  */
 965                 int rc;
 966 #ifdef DEBUG_PM
 967                 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
 968 #endif
 969                 rc = ide_wait_not_busy(HWIF(drive), 35000);
 970                 if (rc)
 971                         printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
 972                 SELECT_DRIVE(drive);
 973                 HWIF(drive)->OUTB(8, HWIF(drive)->io_ports[IDE_CONTROL_OFFSET]);
 974                 rc = ide_wait_not_busy(HWIF(drive), 100000);
 975                 if (rc)
 976                         printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
 977         }
 978 }
 979
 980 /**
 981  *      start_request   -       start of I/O and command issuing for IDE
 982  *
 983  *      start_request() initiates handling of a new I/O request. It
 984  *      accepts commands and I/O (read/write) requests. It also does
 985  *      the final remapping for weird stuff like EZDrive. Once
 986  *      device mapper can work sector level the EZDrive stuff can go away
 987  *
 988  *      FIXME: this function needs a rename
 989  */
 990
 991 static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
 992 {
 993         ide_startstop_t startstop;
 994         sector_t block;
 995
 996         BUG_ON(!blk_rq_started(rq));
 997
 998 #ifdef DEBUG
 999         printk("%s: start_request: current=0x%08lx\n",
1000                 HWIF(drive)->name, (unsigned long) rq);
1001 #endif
1002
1003         /* bail early if we've exceeded max_failures */
1004         if (drive->max_failures && (drive->failures > drive->max_failures)) {
1005                 goto kill_rq;
1006         }
1007
1008         block    = rq->sector;
1009         if (blk_fs_request(rq) &&
1010             (drive->media == ide_disk || drive->media == ide_floppy)) {
1011                 block += drive->sect0;
1012         }
1013         /* Yecch - this will shift the entire interval,
1014            possibly killing some innocent following sector */
1015         if (block == 0 && drive->remap_0_to_1 == 1)
1016                 block = 1;  /* redirect MBR access to EZ-Drive partn table */
1017
1018         if (blk_pm_request(rq))
1019                 ide_check_pm_state(drive, rq);
1020
1021         SELECT_DRIVE(drive);
1022         if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
1023                 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
1024                 return startstop;
1025         }
1026         if (!drive->special.all) {
1027                 ide_driver_t *drv;
1028
1029                 /*
1030                  * We reset the drive so we need to issue a SETFEATURES.
1031                  * Do it _after_ do_special() restored device parameters.
1032                  */
1033                 if (drive->current_speed == 0xff)
1034                         ide_config_drive_speed(drive, drive->desired_speed);
1035
1036                 if (rq->cmd_type == REQ_TYPE_ATA_CMD ||
1037                     rq->cmd_type == REQ_TYPE_ATA_TASK ||
1038                     rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
1039                         return execute_drive_cmd(drive, rq);
1040                 else if (blk_pm_request(rq)) {
1041                         struct request_pm_state *pm = rq->data;
1042 #ifdef DEBUG_PM
1043                         printk("%s: start_power_step(step: %d)\n",
1044                                 drive->name, rq->pm->pm_step);
1045 #endif
1046                         startstop = ide_start_power_step(drive, rq);
1047                         if (startstop == ide_stopped &&
1048                             pm->pm_step == ide_pm_state_completed)
1049                                 ide_complete_pm_request(drive, rq);
1050                         return startstop;
1051                 }
1052
1053                 drv = *(ide_driver_t **)rq->rq_disk->private_data;
1054                 return drv->do_request(drive, rq, block);
1055         }
1056         return do_special(drive);
1057 kill_rq:
1058         ide_kill_rq(drive, rq);
1059         return ide_stopped;
1060 }
1061
1062 /**
1063  *      ide_stall_queue         -       pause an IDE device
1064  *      @drive: drive to stall
1065  *      @timeout: time to stall for (jiffies)
1066  *
1067  *      ide_stall_queue() can be used by a drive to give excess bandwidth back
1068  *      to the hwgroup by sleeping for timeout jiffies.
1069  */
1070
1071 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
1072 {
1073         if (timeout > WAIT_WORSTCASE)
1074                 timeout = WAIT_WORSTCASE;
1075         drive->sleep = timeout + jiffies;
1076         drive->sleeping = 1;
1077 }
1078
1079 EXPORT_SYMBOL(ide_stall_queue);
1080
1081 #define WAKEUP(drive)   ((drive)->service_start + 2 * (drive)->service_time)
1082
1083 /**
1084  *      choose_drive            -       select a drive to service
1085  *      @hwgroup: hardware group to select on
1086  *
1087  *      choose_drive() selects the next drive which will be serviced.
1088  *      This is necessary because the IDE layer can't issue commands
1089  *      to both drives on the same cable, unlike SCSI.
1090  */
1091
1092 static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
1093 {
1094         ide_drive_t *drive, *best;
1095
1096 repeat:
1097         best = NULL;
1098         drive = hwgroup->drive;
1099
1100         /*
1101          * drive is doing pre-flush, ordered write, post-flush sequence. even
1102          * though that is 3 requests, it must be seen as a single transaction.
1103          * we must not preempt this drive until that is complete
1104          */
1105         if (blk_queue_flushing(drive->queue)) {
1106                 /*
1107                  * small race where queue could get replugged during
1108                  * the 3-request flush cycle, just yank the plug since
1109                  * we want it to finish asap
1110                  */
1111                 blk_remove_plug(drive->queue);
1112                 return drive;
1113         }
1114
1115         do {
1116                 if ((!drive->sleeping || time_after_eq(jiffies, drive->sleep))
1117                     && !elv_queue_empty(drive->queue)) {
1118                         if (!best
1119                          || (drive->sleeping && (!best->sleeping || time_before(drive->sleep, best->sleep)))
1120                          || (!best->sleeping && time_before(WAKEUP(drive), WAKEUP(best))))
1121                         {
1122                                 if (!blk_queue_plugged(drive->queue))
1123                                         best = drive;
1124                         }
1125                 }
1126         } while ((drive = drive->next) != hwgroup->drive);
1127         if (best && best->nice1 && !best->sleeping && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
1128                 long t = (signed long)(WAKEUP(best) - jiffies);
1129                 if (t >= WAIT_MIN_SLEEP) {
1130                 /*
1131                  * We *may* have some time to spare, but first let's see if
1132                  * someone can potentially benefit from our nice mood today..
1133                  */
1134                         drive = best->next;
1135                         do {
1136                                 if (!drive->sleeping
1137                                  && time_before(jiffies - best->service_time, WAKEUP(drive))
1138                                  && time_before(WAKEUP(drive), jiffies + t))
1139                                 {
1140                                         ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
1141                                         goto repeat;
1142                                 }
1143                         } while ((drive = drive->next) != best);
1144                 }
1145         }
1146         return best;
1147 }
1148
1149 /*
1150  * Issue a new request to a drive from hwgroup
1151  * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
1152  *
1153  * A hwgroup is a serialized group of IDE interfaces.  Usually there is
1154  * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
1155  * may have both interfaces in a single hwgroup to "serialize" access.
1156  * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
1157  * together into one hwgroup for serialized access.
1158  *
1159  * Note also that several hwgroups can end up sharing a single IRQ,
1160  * possibly along with many other devices.  This is especially common in
1161  * PCI-based systems with off-board IDE controller cards.
1162  *
1163  * The IDE driver uses the single global ide_lock spinlock to protect
1164  * access to the request queues, and to protect the hwgroup->busy flag.
1165  *
1166  * The first thread into the driver for a particular hwgroup sets the
1167  * hwgroup->busy flag to indicate that this hwgroup is now active,
1168  * and then initiates processing of the top request from the request queue.
1169  *
1170  * Other threads attempting entry notice the busy setting, and will simply
1171  * queue their new requests and exit immediately.  Note that hwgroup->busy
1172  * remains set even when the driver is merely awaiting the next interrupt.
1173  * Thus, the meaning is "this hwgroup is busy processing a request".
1174  *
1175  * When processing of a request completes, the completing thread or IRQ-handler
1176  * will start the next request from the queue.  If no more work remains,
1177  * the driver will clear the hwgroup->busy flag and exit.
1178  *
1179  * The ide_lock (spinlock) is used to protect all access to the
1180  * hwgroup->busy flag, but is otherwise not needed for most processing in
1181  * the driver.  This makes the driver much more friendlier to shared IRQs
1182  * than previous designs, while remaining 100% (?) SMP safe and capable.
1183  */
1184 static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
1185 {
1186         ide_drive_t     *drive;
1187         ide_hwif_t      *hwif;
1188         struct request  *rq;
1189         ide_startstop_t startstop;
1190         int             loops = 0;
1191
1192         /* for atari only: POSSIBLY BROKEN HERE(?) */
1193         ide_get_lock(ide_intr, hwgroup);
1194
1195         /* caller must own ide_lock */
1196         BUG_ON(!irqs_disabled());
1197
1198         while (!hwgroup->busy) {
1199                 hwgroup->busy = 1;
1200                 drive = choose_drive(hwgroup);
1201                 if (drive == NULL) {
1202                         int sleeping = 0;
1203                         unsigned long sleep = 0; /* shut up, gcc */
1204                         hwgroup->rq = NULL;
1205                         drive = hwgroup->drive;
1206                         do {
1207                                 if (drive->sleeping && (!sleeping || time_before(drive->sleep, sleep))) {
1208                                         sleeping = 1;
1209                                         sleep = drive->sleep;
1210                                 }
1211                         } while ((drive = drive->next) != hwgroup->drive);
1212                         if (sleeping) {
1213                 /*
1214                  * Take a short snooze, and then wake up this hwgroup again.
1215                  * This gives other hwgroups on the same a chance to
1216                  * play fairly with us, just in case there are big differences
1217                  * in relative throughputs.. don't want to hog the cpu too much.
1218                  */
1219                                 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
1220                                         sleep = jiffies + WAIT_MIN_SLEEP;
1221 #if 1
1222                                 if (timer_pending(&hwgroup->timer))
1223                                         printk(KERN_CRIT "ide_set_handler: timer already active\n");
1224 #endif
1225                                 /* so that ide_timer_expiry knows what to do */
1226                                 hwgroup->sleeping = 1;
1227                                 hwgroup->req_gen_timer = hwgroup->req_gen;
1228                                 mod_timer(&hwgroup->timer, sleep);
1229                                 /* we purposely leave hwgroup->busy==1
1230                                  * while sleeping */
1231                         } else {
1232                                 /* Ugly, but how can we sleep for the lock
1233                                  * otherwise? perhaps from tq_disk?
1234                                  */
1235
1236                                 /* for atari only */
1237                                 ide_release_lock();
1238                                 hwgroup->busy = 0;
1239                         }
1240
1241                         /* no more work for this hwgroup (for now) */
1242                         return;
1243                 }
1244         again:
1245                 hwif = HWIF(drive);
1246                 if (hwgroup->hwif->sharing_irq &&
1247                     hwif != hwgroup->hwif &&
1248                     hwif->io_ports[IDE_CONTROL_OFFSET]) {
1249                         /* set nIEN for previous hwif */
1250                         SELECT_INTERRUPT(drive);
1251                 }
1252                 hwgroup->hwif = hwif;
1253                 hwgroup->drive = drive;
1254                 drive->sleeping = 0;
1255                 drive->service_start = jiffies;
1256
1257                 if (blk_queue_plugged(drive->queue)) {
1258                         printk(KERN_ERR "ide: huh? queue was plugged!\n");
1259                         break;
1260                 }
1261
1262                 /*
1263                  * we know that the queue isn't empty, but this can happen
1264                  * if the q->prep_rq_fn() decides to kill a request
1265                  */
1266                 rq = elv_next_request(drive->queue);
1267                 if (!rq) {
1268                         hwgroup->busy = 0;
1269                         break;
1270                 }
1271
1272                 /*
1273                  * Sanity: don't accept a request that isn't a PM request
1274                  * if we are currently power managed. This is very important as
1275                  * blk_stop_queue() doesn't prevent the elv_next_request()
1276                  * above to return us whatever is in the queue. Since we call
1277                  * ide_do_request() ourselves, we end up taking requests while
1278                  * the queue is blocked...
1279                  *
1280                  * We let requests forced at head of queue with ide-preempt
1281                  * though. I hope that doesn't happen too much, hopefully not
1282                  * unless the subdriver triggers such a thing in its own PM
1283                  * state machine.
1284                  *
1285                  * We count how many times we loop here to make sure we service
1286                  * all drives in the hwgroup without looping for ever
1287                  */
1288                 if (drive->blocked && !blk_pm_request(rq) && !(rq->cmd_flags & REQ_PREEMPT)) {
1289                         drive = drive->next ? drive->next : hwgroup->drive;
1290                         if (loops++ < 4 && !blk_queue_plugged(drive->queue))
1291                                 goto again;
1292                         /* We clear busy, there should be no pending ATA command at this point. */
1293                         hwgroup->busy = 0;
1294                         break;
1295                 }
1296
1297                 hwgroup->rq = rq;
1298
1299                 /*
1300                  * Some systems have trouble with IDE IRQs arriving while
1301                  * the driver is still setting things up.  So, here we disable
1302                  * the IRQ used by this interface while the request is being started.
1303                  * This may look bad at first, but pretty much the same thing
1304                  * happens anyway when any interrupt comes in, IDE or otherwise
1305                  *  -- the kernel masks the IRQ while it is being handled.
1306                  */
1307                 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1308                         disable_irq_nosync(hwif->irq);
1309                 spin_unlock(&ide_lock);
1310                 local_irq_enable_in_hardirq();
1311                         /* allow other IRQs while we start this request */
1312                 startstop = start_request(drive, rq);
1313                 spin_lock_irq(&ide_lock);
1314                 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1315                         enable_irq(hwif->irq);
1316                 if (startstop == ide_stopped)
1317                         hwgroup->busy = 0;
1318         }
1319 }
1320
1321 /*
1322  * Passes the stuff to ide_do_request
1323  */
1324 void do_ide_request(request_queue_t *q)
1325 {
1326         ide_drive_t *drive = q->queuedata;
1327
1328         ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1329 }
1330
1331 /*
1332  * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1333  * retry the current request in pio mode instead of risking tossing it
1334  * all away
1335  */
1336 static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1337 {
1338         ide_hwif_t *hwif = HWIF(drive);
1339         struct request *rq;
1340         ide_startstop_t ret = ide_stopped;
1341
1342         /*
1343          * end current dma transaction
1344          */
1345
1346         if (error < 0) {
1347                 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1348                 (void)HWIF(drive)->ide_dma_end(drive);
1349                 ret = ide_error(drive, "dma timeout error",
1350                                                 hwif->INB(IDE_STATUS_REG));
1351         } else {
1352                 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
1353                 (void) hwif->ide_dma_timeout(drive);
1354         }
1355
1356         /*
1357          * disable dma for now, but remember that we did so because of
1358          * a timeout -- we'll reenable after we finish this next request
1359          * (or rather the first chunk of it) in pio.
1360          */
1361         drive->retry_pio++;
1362         drive->state = DMA_PIO_RETRY;
1363         hwif->dma_off_quietly(drive);
1364
1365         /*
1366          * un-busy drive etc (hwgroup->busy is cleared on return) and
1367          * make sure request is sane
1368          */
1369         rq = HWGROUP(drive)->rq;
1370
1371         if (!rq)
1372                 goto out;
1373
1374         HWGROUP(drive)->rq = NULL;
1375
1376         rq->errors = 0;
1377
1378         if (!rq->bio)
1379                 goto out;
1380
1381         rq->sector = rq->bio->bi_sector;
1382         rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1383         rq->hard_cur_sectors = rq->current_nr_sectors;
1384         rq->buffer = bio_data(rq->bio);
1385 out:
1386         return ret;
1387 }
1388
1389 /**
1390  *      ide_timer_expiry        -       handle lack of an IDE interrupt
1391  *      @data: timer callback magic (hwgroup)
1392  *
1393  *      An IDE command has timed out before the expected drive return
1394  *      occurred. At this point we attempt to clean up the current
1395  *      mess. If the current handler includes an expiry handler then
1396  *      we invoke the expiry handler, and providing it is happy the
1397  *      work is done. If that fails we apply generic recovery rules
1398  *      invoking the handler and checking the drive DMA status. We
1399  *      have an excessively incestuous relationship with the DMA
1400  *      logic that wants cleaning up.
1401  */
1402
1403 void ide_timer_expiry (unsigned long data)
1404 {
1405         ide_hwgroup_t   *hwgroup = (ide_hwgroup_t *) data;
1406         ide_handler_t   *handler;
1407         ide_expiry_t    *expiry;
1408         unsigned long   flags;
1409         unsigned long   wait = -1;
1410
1411         spin_lock_irqsave(&ide_lock, flags);
1412
1413         if (((handler = hwgroup->handler) == NULL) ||
1414             (hwgroup->req_gen != hwgroup->req_gen_timer)) {
1415                 /*
1416                  * Either a marginal timeout occurred
1417                  * (got the interrupt just as timer expired),
1418                  * or we were "sleeping" to give other devices a chance.
1419                  * Either way, we don't really want to complain about anything.
1420                  */
1421                 if (hwgroup->sleeping) {
1422                         hwgroup->sleeping = 0;
1423                         hwgroup->busy = 0;
1424                 }
1425         } else {
1426                 ide_drive_t *drive = hwgroup->drive;
1427                 if (!drive) {
1428                         printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1429                         hwgroup->handler = NULL;
1430                 } else {
1431                         ide_hwif_t *hwif;
1432                         ide_startstop_t startstop = ide_stopped;
1433                         if (!hwgroup->busy) {
1434                                 hwgroup->busy = 1;      /* paranoia */
1435                                 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1436                         }
1437                         if ((expiry = hwgroup->expiry) != NULL) {
1438                                 /* continue */
1439                                 if ((wait = expiry(drive)) > 0) {
1440                                         /* reset timer */
1441                                         hwgroup->timer.expires  = jiffies + wait;
1442                                         hwgroup->req_gen_timer = hwgroup->req_gen;
1443                                         add_timer(&hwgroup->timer);
1444                                         spin_unlock_irqrestore(&ide_lock, flags);
1445                                         return;
1446                                 }
1447                         }
1448                         hwgroup->handler = NULL;
1449                         /*
1450                          * We need to simulate a real interrupt when invoking
1451                          * the handler() function, which means we need to
1452                          * globally mask the specific IRQ:
1453                          */
1454                         spin_unlock(&ide_lock);
1455                         hwif  = HWIF(drive);
1456 #if DISABLE_IRQ_NOSYNC
1457                         disable_irq_nosync(hwif->irq);
1458 #else
1459                         /* disable_irq_nosync ?? */
1460                         disable_irq(hwif->irq);
1461 #endif /* DISABLE_IRQ_NOSYNC */
1462                         /* local CPU only,
1463                          * as if we were handling an interrupt */
1464                         local_irq_disable();
1465                         if (hwgroup->polling) {
1466                                 startstop = handler(drive);
1467                         } else if (drive_is_ready(drive)) {
1468                                 if (drive->waiting_for_dma)
1469                                         (void) hwgroup->hwif->ide_dma_lostirq(drive);
1470                                 (void)ide_ack_intr(hwif);
1471                                 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1472                                 startstop = handler(drive);
1473                         } else {
1474                                 if (drive->waiting_for_dma) {
1475                                         startstop = ide_dma_timeout_retry(drive, wait);
1476                                 } else
1477                                         startstop =
1478                                         ide_error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1479                         }
1480                         drive->service_time = jiffies - drive->service_start;
1481                         spin_lock_irq(&ide_lock);
1482                         enable_irq(hwif->irq);
1483                         if (startstop == ide_stopped)
1484                                 hwgroup->busy = 0;
1485                 }
1486         }
1487         ide_do_request(hwgroup, IDE_NO_IRQ);
1488         spin_unlock_irqrestore(&ide_lock, flags);
1489 }
1490
1491 /**
1492  *      unexpected_intr         -       handle an unexpected IDE interrupt
1493  *      @irq: interrupt line
1494  *      @hwgroup: hwgroup being processed
1495  *
1496  *      There's nothing really useful we can do with an unexpected interrupt,
1497  *      other than reading the status register (to clear it), and logging it.
1498  *      There should be no way that an irq can happen before we're ready for it,
1499  *      so we needn't worry much about losing an "important" interrupt here.
1500  *
1501  *      On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1502  *      the drive enters "idle", "standby", or "sleep" mode, so if the status
1503  *      looks "good", we just ignore the interrupt completely.
1504  *
1505  *      This routine assumes __cli() is in effect when called.
1506  *
1507  *      If an unexpected interrupt happens on irq15 while we are handling irq14
1508  *      and if the two interfaces are "serialized" (CMD640), then it looks like
1509  *      we could screw up by interfering with a new request being set up for
1510  *      irq15.
1511  *
1512  *      In reality, this is a non-issue.  The new command is not sent unless
1513  *      the drive is ready to accept one, in which case we know the drive is
1514  *      not trying to interrupt us.  And ide_set_handler() is always invoked
1515  *      before completing the issuance of any new drive command, so we will not
1516  *      be accidentally invoked as a result of any valid command completion
1517  *      interrupt.
1518  *
1519  *      Note that we must walk the entire hwgroup here. We know which hwif
1520  *      is doing the current command, but we don't know which hwif burped
1521  *      mysteriously.
1522  */
1523
1524 static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1525 {
1526         u8 stat;
1527         ide_hwif_t *hwif = hwgroup->hwif;
1528
1529         /*
1530          * handle the unexpected interrupt
1531          */
1532         do {
1533                 if (hwif->irq == irq) {
1534                         stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1535                         if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1536                                 /* Try to not flood the console with msgs */
1537                                 static unsigned long last_msgtime, count;
1538                                 ++count;
1539                                 if (time_after(jiffies, last_msgtime + HZ)) {
1540                                         last_msgtime = jiffies;
1541                                         printk(KERN_ERR "%s%s: unexpected interrupt, "
1542                                                 "status=0x%02x, count=%ld\n",
1543                                                 hwif->name,
1544                                                 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1545                                 }
1546                         }
1547                 }
1548         } while ((hwif = hwif->next) != hwgroup->hwif);
1549 }
1550
1551 /**
1552  *      ide_intr        -       default IDE interrupt handler
1553  *      @irq: interrupt number
1554  *      @dev_id: hwif group
1555  *      @regs: unused weirdness from the kernel irq layer
1556  *
1557  *      This is the default IRQ handler for the IDE layer. You should
1558  *      not need to override it. If you do be aware it is subtle in
1559  *      places
1560  *
1561  *      hwgroup->hwif is the interface in the group currently performing
1562  *      a command. hwgroup->drive is the drive and hwgroup->handler is
1563  *      the IRQ handler to call. As we issue a command the handlers
1564  *      step through multiple states, reassigning the handler to the
1565  *      next step in the process. Unlike a smart SCSI controller IDE
1566  *      expects the main processor to sequence the various transfer
1567  *      stages. We also manage a poll timer to catch up with most
1568  *      timeout situations. There are still a few where the handlers
1569  *      don't ever decide to give up.
1570  *
1571  *      The handler eventually returns ide_stopped to indicate the
1572  *      request completed. At this point we issue the next request
1573  *      on the hwgroup and the process begins again.
1574  */
1575
1576 irqreturn_t ide_intr (int irq, void *dev_id)
1577 {
1578         unsigned long flags;
1579         ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1580         ide_hwif_t *hwif;
1581         ide_drive_t *drive;
1582         ide_handler_t *handler;
1583         ide_startstop_t startstop;
1584
1585         spin_lock_irqsave(&ide_lock, flags);
1586         hwif = hwgroup->hwif;
1587
1588         if (!ide_ack_intr(hwif)) {
1589                 spin_unlock_irqrestore(&ide_lock, flags);
1590                 return IRQ_NONE;
1591         }
1592
1593         if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
1594                 /*
1595                  * Not expecting an interrupt from this drive.
1596                  * That means this could be:
1597                  *      (1) an interrupt from another PCI device
1598                  *      sharing the same PCI INT# as us.
1599                  * or   (2) a drive just entered sleep or standby mode,
1600                  *      and is interrupting to let us know.
1601                  * or   (3) a spurious interrupt of unknown origin.
1602                  *
1603                  * For PCI, we cannot tell the difference,
1604                  * so in that case we just ignore it and hope it goes away.
1605                  *
1606                  * FIXME: unexpected_intr should be hwif-> then we can
1607                  * remove all the ifdef PCI crap
1608                  */
1609 #ifdef CONFIG_BLK_DEV_IDEPCI
1610                 if (hwif->pci_dev && !hwif->pci_dev->vendor)
1611 #endif  /* CONFIG_BLK_DEV_IDEPCI */
1612                 {
1613                         /*
1614                          * Probably not a shared PCI interrupt,
1615                          * so we can safely try to do something about it:
1616                          */
1617                         unexpected_intr(irq, hwgroup);
1618 #ifdef CONFIG_BLK_DEV_IDEPCI
1619                 } else {
1620                         /*
1621                          * Whack the status register, just in case
1622                          * we have a leftover pending IRQ.
1623                          */
1624                         (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1625 #endif /* CONFIG_BLK_DEV_IDEPCI */
1626                 }
1627                 spin_unlock_irqrestore(&ide_lock, flags);
1628                 return IRQ_NONE;
1629         }
1630         drive = hwgroup->drive;
1631         if (!drive) {
1632                 /*
1633                  * This should NEVER happen, and there isn't much
1634                  * we could do about it here.
1635                  *
1636                  * [Note - this can occur if the drive is hot unplugged]
1637                  */
1638                 spin_unlock_irqrestore(&ide_lock, flags);
1639                 return IRQ_HANDLED;
1640         }
1641         if (!drive_is_ready(drive)) {
1642                 /*
1643                  * This happens regularly when we share a PCI IRQ with
1644                  * another device.  Unfortunately, it can also happen
1645                  * with some buggy drives that trigger the IRQ before
1646                  * their status register is up to date.  Hopefully we have
1647                  * enough advance overhead that the latter isn't a problem.
1648                  */
1649                 spin_unlock_irqrestore(&ide_lock, flags);
1650                 return IRQ_NONE;
1651         }
1652         if (!hwgroup->busy) {
1653                 hwgroup->busy = 1;      /* paranoia */
1654                 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1655         }
1656         hwgroup->handler = NULL;
1657         hwgroup->req_gen++;
1658         del_timer(&hwgroup->timer);
1659         spin_unlock(&ide_lock);
1660
1661         /* Some controllers might set DMA INTR no matter DMA or PIO;
1662          * bmdma status might need to be cleared even for
1663          * PIO interrupts to prevent spurious/lost irq.
1664          */
1665         if (hwif->ide_dma_clear_irq && !(drive->waiting_for_dma))
1666                 /* ide_dma_end() needs bmdma status for error checking.
1667                  * So, skip clearing bmdma status here and leave it
1668                  * to ide_dma_end() if this is dma interrupt.
1669                  */
1670                 hwif->ide_dma_clear_irq(drive);
1671
1672         if (drive->unmask)
1673                 local_irq_enable_in_hardirq();
1674         /* service this interrupt, may set handler for next interrupt */
1675         startstop = handler(drive);
1676         spin_lock_irq(&ide_lock);
1677
1678         /*
1679          * Note that handler() may have set things up for another
1680          * interrupt to occur soon, but it cannot happen until
1681          * we exit from this routine, because it will be the
1682          * same irq as is currently being serviced here, and Linux
1683          * won't allow another of the same (on any CPU) until we return.
1684          */
1685         drive->service_time = jiffies - drive->service_start;
1686         if (startstop == ide_stopped) {
1687                 if (hwgroup->handler == NULL) { /* paranoia */
1688                         hwgroup->busy = 0;
1689                         ide_do_request(hwgroup, hwif->irq);
1690                 } else {
1691                         printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1692                                 "on exit\n", drive->name);
1693                 }
1694         }
1695         spin_unlock_irqrestore(&ide_lock, flags);
1696         return IRQ_HANDLED;
1697 }
1698
1699 /**
1700  *      ide_init_drive_cmd      -       initialize a drive command request
1701  *      @rq: request object
1702  *
1703  *      Initialize a request before we fill it in and send it down to
1704  *      ide_do_drive_cmd. Commands must be set up by this function. Right
1705  *      now it doesn't do a lot, but if that changes abusers will have a
1706  *      nasty surprise.
1707  */
1708
1709 void ide_init_drive_cmd (struct request *rq)
1710 {
1711         memset(rq, 0, sizeof(*rq));
1712         rq->cmd_type = REQ_TYPE_ATA_CMD;
1713         rq->ref_count = 1;
1714 }
1715
1716 EXPORT_SYMBOL(ide_init_drive_cmd);
1717
1718 /**
1719  *      ide_do_drive_cmd        -       issue IDE special command
1720  *      @drive: device to issue command
1721  *      @rq: request to issue
1722  *      @action: action for processing
1723  *
1724  *      This function issues a special IDE device request
1725  *      onto the request queue.
1726  *
1727  *      If action is ide_wait, then the rq is queued at the end of the
1728  *      request queue, and the function sleeps until it has been processed.
1729  *      This is for use when invoked from an ioctl handler.
1730  *
1731  *      If action is ide_preempt, then the rq is queued at the head of
1732  *      the request queue, displacing the currently-being-processed
1733  *      request and this function returns immediately without waiting
1734  *      for the new rq to be completed.  This is VERY DANGEROUS, and is
1735  *      intended for careful use by the ATAPI tape/cdrom driver code.
1736  *
1737  *      If action is ide_end, then the rq is queued at the end of the
1738  *      request queue, and the function returns immediately without waiting
1739  *      for the new rq to be completed. This is again intended for careful
1740  *      use by the ATAPI tape/cdrom driver code.
1741  */
1742
1743 int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1744 {
1745         unsigned long flags;
1746         ide_hwgroup_t *hwgroup = HWGROUP(drive);
1747         DECLARE_COMPLETION_ONSTACK(wait);
1748         int where = ELEVATOR_INSERT_BACK, err;
1749         int must_wait = (action == ide_wait || action == ide_head_wait);
1750
1751         rq->errors = 0;
1752
1753         /*
1754          * we need to hold an extra reference to request for safe inspection
1755          * after completion
1756          */
1757         if (must_wait) {
1758                 rq->ref_count++;
1759                 rq->end_io_data = &wait;
1760                 rq->end_io = blk_end_sync_rq;
1761         }
1762
1763         spin_lock_irqsave(&ide_lock, flags);
1764         if (action == ide_preempt)
1765                 hwgroup->rq = NULL;
1766         if (action == ide_preempt || action == ide_head_wait) {
1767                 where = ELEVATOR_INSERT_FRONT;
1768                 rq->cmd_flags |= REQ_PREEMPT;
1769         }
1770         __elv_add_request(drive->queue, rq, where, 0);
1771         ide_do_request(hwgroup, IDE_NO_IRQ);
1772         spin_unlock_irqrestore(&ide_lock, flags);
1773
1774         err = 0;
1775         if (must_wait) {
1776                 wait_for_completion(&wait);
1777                 if (rq->errors)
1778                         err = -EIO;
1779
1780                 blk_put_request(rq);
1781         }
1782
1783         return err;
1784 }
1785
1786 EXPORT_SYMBOL(ide_do_drive_cmd);