linux/drivers/ide/ide-io.c
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   1/*
   2 *      IDE I/O functions
   3 *
   4 *      Basic PIO and command management functionality.
   5 *
   6 * This code was split off from ide.c. See ide.c for history and original
   7 * copyrights.
   8 *
   9 * This program is free software; you can redistribute it and/or modify it
  10 * under the terms of the GNU General Public License as published by the
  11 * Free Software Foundation; either version 2, or (at your option) any
  12 * later version.
  13 *
  14 * This program is distributed in the hope that it will be useful, but
  15 * WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 * General Public License for more details.
  18 *
  19 * For the avoidance of doubt the "preferred form" of this code is one which
  20 * is in an open non patent encumbered format. Where cryptographic key signing
  21 * forms part of the process of creating an executable the information
  22 * including keys needed to generate an equivalently functional executable
  23 * are deemed to be part of the source code.
  24 */
  25 
  26 
  27#include <linux/module.h>
  28#include <linux/types.h>
  29#include <linux/string.h>
  30#include <linux/kernel.h>
  31#include <linux/timer.h>
  32#include <linux/mm.h>
  33#include <linux/interrupt.h>
  34#include <linux/major.h>
  35#include <linux/errno.h>
  36#include <linux/genhd.h>
  37#include <linux/blkpg.h>
  38#include <linux/slab.h>
  39#include <linux/init.h>
  40#include <linux/pci.h>
  41#include <linux/delay.h>
  42#include <linux/ide.h>
  43#include <linux/completion.h>
  44#include <linux/reboot.h>
  45#include <linux/cdrom.h>
  46#include <linux/seq_file.h>
  47#include <linux/device.h>
  48#include <linux/kmod.h>
  49#include <linux/scatterlist.h>
  50#include <linux/bitops.h>
  51
  52#include <asm/byteorder.h>
  53#include <asm/irq.h>
  54#include <asm/uaccess.h>
  55#include <asm/io.h>
  56
  57static int __ide_end_request(ide_drive_t *drive, struct request *rq,
  58                             int uptodate, unsigned int nr_bytes, int dequeue)
  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_bytes = rq->hard_nr_sectors << 9;
  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_chunk(rq, uptodate, nr_bytes)) {
  82                add_disk_randomness(rq->rq_disk);
  83                if (dequeue) {
  84                        if (!list_empty(&rq->queuelist))
  85                                blkdev_dequeue_request(rq);
  86                        HWGROUP(drive)->rq = NULL;
  87                }
  88                end_that_request_last(rq, uptodate);
  89                ret = 0;
  90        }
  91
  92        return ret;
  93}
  94
  95/**
  96 *      ide_end_request         -       complete an IDE I/O
  97 *      @drive: IDE device for the I/O
  98 *      @uptodate:
  99 *      @nr_sectors: number of sectors completed
 100 *
 101 *      This is our end_request wrapper function. We complete the I/O
 102 *      update random number input and dequeue the request, which if
 103 *      it was tagged may be out of order.
 104 */
 105
 106int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
 107{
 108        unsigned int nr_bytes = nr_sectors << 9;
 109        struct request *rq;
 110        unsigned long flags;
 111        int ret = 1;
 112
 113        /*
 114         * room for locking improvements here, the calls below don't
 115         * need the queue lock held at all
 116         */
 117        spin_lock_irqsave(&ide_lock, flags);
 118        rq = HWGROUP(drive)->rq;
 119
 120        if (!nr_bytes) {
 121                if (blk_pc_request(rq))
 122                        nr_bytes = rq->data_len;
 123                else
 124                        nr_bytes = rq->hard_cur_sectors << 9;
 125        }
 126
 127        ret = __ide_end_request(drive, rq, uptodate, nr_bytes, 1);
 128
 129        spin_unlock_irqrestore(&ide_lock, flags);
 130        return ret;
 131}
 132EXPORT_SYMBOL(ide_end_request);
 133
 134/*
 135 * Power Management state machine. This one is rather trivial for now,
 136 * we should probably add more, like switching back to PIO on suspend
 137 * to help some BIOSes, re-do the door locking on resume, etc...
 138 */
 139
 140enum {
 141        ide_pm_flush_cache      = ide_pm_state_start_suspend,
 142        idedisk_pm_standby,
 143
 144        idedisk_pm_restore_pio  = ide_pm_state_start_resume,
 145        idedisk_pm_idle,
 146        ide_pm_restore_dma,
 147};
 148
 149static void ide_complete_power_step(ide_drive_t *drive, struct request *rq, u8 stat, u8 error)
 150{
 151        struct request_pm_state *pm = rq->data;
 152
 153        if (drive->media != ide_disk)
 154                return;
 155
 156        switch (pm->pm_step) {
 157        case ide_pm_flush_cache:        /* Suspend step 1 (flush cache) complete */
 158                if (pm->pm_state == PM_EVENT_FREEZE)
 159                        pm->pm_step = ide_pm_state_completed;
 160                else
 161                        pm->pm_step = idedisk_pm_standby;
 162                break;
 163        case idedisk_pm_standby:        /* Suspend step 2 (standby) complete */
 164                pm->pm_step = ide_pm_state_completed;
 165                break;
 166        case idedisk_pm_restore_pio:    /* Resume step 1 complete */
 167                pm->pm_step = idedisk_pm_idle;
 168                break;
 169        case idedisk_pm_idle:           /* Resume step 2 (idle) complete */
 170                pm->pm_step = ide_pm_restore_dma;
 171                break;
 172        }
 173}
 174
 175static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
 176{
 177        struct request_pm_state *pm = rq->data;
 178        ide_task_t *args = rq->special;
 179
 180        memset(args, 0, sizeof(*args));
 181
 182        switch (pm->pm_step) {
 183        case ide_pm_flush_cache:        /* Suspend step 1 (flush cache) */
 184                if (drive->media != ide_disk)
 185                        break;
 186                /* Not supported? Switch to next step now. */
 187                if (!drive->wcache || !ide_id_has_flush_cache(drive->id)) {
 188                        ide_complete_power_step(drive, rq, 0, 0);
 189                        return ide_stopped;
 190                }
 191                if (ide_id_has_flush_cache_ext(drive->id))
 192                        args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE_EXT;
 193                else
 194                        args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE;
 195                args->command_type = IDE_DRIVE_TASK_NO_DATA;
 196                args->handler      = &task_no_data_intr;
 197                return do_rw_taskfile(drive, args);
 198
 199        case idedisk_pm_standby:        /* Suspend step 2 (standby) */
 200                args->tfRegister[IDE_COMMAND_OFFSET] = WIN_STANDBYNOW1;
 201                args->command_type = IDE_DRIVE_TASK_NO_DATA;
 202                args->handler      = &task_no_data_intr;
 203                return do_rw_taskfile(drive, args);
 204
 205        case idedisk_pm_restore_pio:    /* Resume step 1 (restore PIO) */
 206                ide_set_max_pio(drive);
 207                /*
 208                 * skip idedisk_pm_idle for ATAPI devices
 209                 */
 210                if (drive->media != ide_disk)
 211                        pm->pm_step = ide_pm_restore_dma;
 212                else
 213                        ide_complete_power_step(drive, rq, 0, 0);
 214                return ide_stopped;
 215
 216        case idedisk_pm_idle:           /* Resume step 2 (idle) */
 217                args->tfRegister[IDE_COMMAND_OFFSET] = WIN_IDLEIMMEDIATE;
 218                args->command_type = IDE_DRIVE_TASK_NO_DATA;
 219                args->handler = task_no_data_intr;
 220                return do_rw_taskfile(drive, args);
 221
 222        case ide_pm_restore_dma:        /* Resume step 3 (restore DMA) */
 223                /*
 224                 * Right now, all we do is call ide_set_dma(drive),
 225                 * we could be smarter and check for current xfer_speed
 226                 * in struct drive etc...
 227                 */
 228                if (drive->hwif->ide_dma_on == NULL)
 229                        break;
 230                drive->hwif->dma_off_quietly(drive);
 231                /*
 232                 * TODO: respect ->using_dma setting
 233                 */
 234                ide_set_dma(drive);
 235                break;
 236        }
 237        pm->pm_step = ide_pm_state_completed;
 238        return ide_stopped;
 239}
 240
 241/**
 242 *      ide_end_dequeued_request        -       complete an IDE I/O
 243 *      @drive: IDE device for the I/O
 244 *      @uptodate:
 245 *      @nr_sectors: number of sectors completed
 246 *
 247 *      Complete an I/O that is no longer on the request queue. This
 248 *      typically occurs when we pull the request and issue a REQUEST_SENSE.
 249 *      We must still finish the old request but we must not tamper with the
 250 *      queue in the meantime.
 251 *
 252 *      NOTE: This path does not handle barrier, but barrier is not supported
 253 *      on ide-cd anyway.
 254 */
 255
 256int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
 257                             int uptodate, int nr_sectors)
 258{
 259        unsigned long flags;
 260        int ret;
 261
 262        spin_lock_irqsave(&ide_lock, flags);
 263        BUG_ON(!blk_rq_started(rq));
 264        ret = __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0);
 265        spin_unlock_irqrestore(&ide_lock, flags);
 266
 267        return ret;
 268}
 269EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
 270
 271
 272/**
 273 *      ide_complete_pm_request - end the current Power Management request
 274 *      @drive: target drive
 275 *      @rq: request
 276 *
 277 *      This function cleans up the current PM request and stops the queue
 278 *      if necessary.
 279 */
 280static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
 281{
 282        unsigned long flags;
 283
 284#ifdef DEBUG_PM
 285        printk("%s: completing PM request, %s\n", drive->name,
 286               blk_pm_suspend_request(rq) ? "suspend" : "resume");
 287#endif
 288        spin_lock_irqsave(&ide_lock, flags);
 289        if (blk_pm_suspend_request(rq)) {
 290                blk_stop_queue(drive->queue);
 291        } else {
 292                drive->blocked = 0;
 293                blk_start_queue(drive->queue);
 294        }
 295        blkdev_dequeue_request(rq);
 296        HWGROUP(drive)->rq = NULL;
 297        end_that_request_last(rq, 1);
 298        spin_unlock_irqrestore(&ide_lock, flags);
 299}
 300
 301/**
 302 *      ide_end_drive_cmd       -       end an explicit drive command
 303 *      @drive: command 
 304 *      @stat: status bits
 305 *      @err: error bits
 306 *
 307 *      Clean up after success/failure of an explicit drive command.
 308 *      These get thrown onto the queue so they are synchronized with
 309 *      real I/O operations on the drive.
 310 *
 311 *      In LBA48 mode we have to read the register set twice to get
 312 *      all the extra information out.
 313 */
 314 
 315void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
 316{
 317        ide_hwif_t *hwif = HWIF(drive);
 318        unsigned long flags;
 319        struct request *rq;
 320
 321        spin_lock_irqsave(&ide_lock, flags);
 322        rq = HWGROUP(drive)->rq;
 323        spin_unlock_irqrestore(&ide_lock, flags);
 324
 325        if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
 326                u8 *args = (u8 *) rq->buffer;
 327                if (rq->errors == 0)
 328                        rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
 329
 330                if (args) {
 331                        args[0] = stat;
 332                        args[1] = err;
 333                        args[2] = hwif->INB(IDE_NSECTOR_REG);
 334                }
 335        } else if (rq->cmd_type == REQ_TYPE_ATA_TASK) {
 336                u8 *args = (u8 *) rq->buffer;
 337                if (rq->errors == 0)
 338                        rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
 339
 340                if (args) {
 341                        args[0] = stat;
 342                        args[1] = err;
 343                        /* be sure we're looking at the low order bits */
 344                        hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
 345                        args[2] = hwif->INB(IDE_NSECTOR_REG);
 346                        args[3] = hwif->INB(IDE_SECTOR_REG);
 347                        args[4] = hwif->INB(IDE_LCYL_REG);
 348                        args[5] = hwif->INB(IDE_HCYL_REG);
 349                        args[6] = hwif->INB(IDE_SELECT_REG);
 350                }
 351        } else if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
 352                ide_task_t *args = (ide_task_t *) rq->special;
 353                if (rq->errors == 0)
 354                        rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
 355                        
 356                if (args) {
 357                        if (args->tf_in_flags.b.data) {
 358                                u16 data                                = hwif->INW(IDE_DATA_REG);
 359                                args->tfRegister[IDE_DATA_OFFSET]       = (data) & 0xFF;
 360                                args->hobRegister[IDE_DATA_OFFSET]      = (data >> 8) & 0xFF;
 361                        }
 362                        args->tfRegister[IDE_ERROR_OFFSET]   = err;
 363                        /* be sure we're looking at the low order bits */
 364                        hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
 365                        args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
 366                        args->tfRegister[IDE_SECTOR_OFFSET]  = hwif->INB(IDE_SECTOR_REG);
 367                        args->tfRegister[IDE_LCYL_OFFSET]    = hwif->INB(IDE_LCYL_REG);
 368                        args->tfRegister[IDE_HCYL_OFFSET]    = hwif->INB(IDE_HCYL_REG);
 369                        args->tfRegister[IDE_SELECT_OFFSET]  = hwif->INB(IDE_SELECT_REG);
 370                        args->tfRegister[IDE_STATUS_OFFSET]  = stat;
 371
 372                        if (drive->addressing == 1) {
 373                                hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
 374                                args->hobRegister[IDE_FEATURE_OFFSET]   = hwif->INB(IDE_FEATURE_REG);
 375                                args->hobRegister[IDE_NSECTOR_OFFSET]   = hwif->INB(IDE_NSECTOR_REG);
 376                                args->hobRegister[IDE_SECTOR_OFFSET]    = hwif->INB(IDE_SECTOR_REG);
 377                                args->hobRegister[IDE_LCYL_OFFSET]      = hwif->INB(IDE_LCYL_REG);
 378                                args->hobRegister[IDE_HCYL_OFFSET]      = hwif->INB(IDE_HCYL_REG);
 379                        }
 380                }
 381        } else if (blk_pm_request(rq)) {
 382                struct request_pm_state *pm = rq->data;
 383#ifdef DEBUG_PM
 384                printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
 385                        drive->name, rq->pm->pm_step, stat, err);
 386#endif
 387                ide_complete_power_step(drive, rq, stat, err);
 388                if (pm->pm_step == ide_pm_state_completed)
 389                        ide_complete_pm_request(drive, rq);
 390                return;
 391        }
 392
 393        spin_lock_irqsave(&ide_lock, flags);
 394        blkdev_dequeue_request(rq);
 395        HWGROUP(drive)->rq = NULL;
 396        rq->errors = err;
 397        end_that_request_last(rq, !rq->errors);
 398        spin_unlock_irqrestore(&ide_lock, flags);
 399}
 400
 401EXPORT_SYMBOL(ide_end_drive_cmd);
 402
 403/**
 404 *      try_to_flush_leftover_data      -       flush junk
 405 *      @drive: drive to flush
 406 *
 407 *      try_to_flush_leftover_data() is invoked in response to a drive
 408 *      unexpectedly having its DRQ_STAT bit set.  As an alternative to
 409 *      resetting the drive, this routine tries to clear the condition
 410 *      by read a sector's worth of data from the drive.  Of course,
 411 *      this may not help if the drive is *waiting* for data from *us*.
 412 */
 413static void try_to_flush_leftover_data (ide_drive_t *drive)
 414{
 415        int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
 416
 417        if (drive->media != ide_disk)
 418                return;
 419        while (i > 0) {
 420                u32 buffer[16];
 421                u32 wcount = (i > 16) ? 16 : i;
 422
 423                i -= wcount;
 424                HWIF(drive)->ata_input_data(drive, buffer, wcount);
 425        }
 426}
 427
 428static void ide_kill_rq(ide_drive_t *drive, struct request *rq)
 429{
 430        if (rq->rq_disk) {
 431                ide_driver_t *drv;
 432
 433                drv = *(ide_driver_t **)rq->rq_disk->private_data;
 434                drv->end_request(drive, 0, 0);
 435        } else
 436                ide_end_request(drive, 0, 0);
 437}
 438
 439static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
 440{
 441        ide_hwif_t *hwif = drive->hwif;
 442
 443        if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
 444                /* other bits are useless when BUSY */
 445                rq->errors |= ERROR_RESET;
 446        } else if (stat & ERR_STAT) {
 447                /* err has different meaning on cdrom and tape */
 448                if (err == ABRT_ERR) {
 449                        if (drive->select.b.lba &&
 450                            /* some newer drives don't support WIN_SPECIFY */
 451                            hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY)
 452                                return ide_stopped;
 453                } else if ((err & BAD_CRC) == BAD_CRC) {
 454                        /* UDMA crc error, just retry the operation */
 455                        drive->crc_count++;
 456                } else if (err & (BBD_ERR | ECC_ERR)) {
 457                        /* retries won't help these */
 458                        rq->errors = ERROR_MAX;
 459                } else if (err & TRK0_ERR) {
 460                        /* help it find track zero */
 461                        rq->errors |= ERROR_RECAL;
 462                }
 463        }
 464
 465        if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ &&
 466            (hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0)
 467                try_to_flush_leftover_data(drive);
 468
 469        if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) {
 470                ide_kill_rq(drive, rq);
 471                return ide_stopped;
 472        }
 473
 474        if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
 475                rq->errors |= ERROR_RESET;
 476
 477        if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
 478                ++rq->errors;
 479                return ide_do_reset(drive);
 480        }
 481
 482        if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
 483                drive->special.b.recalibrate = 1;
 484
 485        ++rq->errors;
 486
 487        return ide_stopped;
 488}
 489
 490static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
 491{
 492        ide_hwif_t *hwif = drive->hwif;
 493
 494        if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
 495                /* other bits are useless when BUSY */
 496                rq->errors |= ERROR_RESET;
 497        } else {
 498                /* add decoding error stuff */
 499        }
 500
 501        if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
 502                /* force an abort */
 503                hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
 504
 505        if (rq->errors >= ERROR_MAX) {
 506                ide_kill_rq(drive, rq);
 507        } else {
 508                if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
 509                        ++rq->errors;
 510                        return ide_do_reset(drive);
 511                }
 512                ++rq->errors;
 513        }
 514
 515        return ide_stopped;
 516}
 517
 518ide_startstop_t
 519__ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
 520{
 521        if (drive->media == ide_disk)
 522                return ide_ata_error(drive, rq, stat, err);
 523        return ide_atapi_error(drive, rq, stat, err);
 524}
 525
 526EXPORT_SYMBOL_GPL(__ide_error);
 527
 528/**
 529 *      ide_error       -       handle an error on the IDE
 530 *      @drive: drive the error occurred on
 531 *      @msg: message to report
 532 *      @stat: status bits
 533 *
 534 *      ide_error() takes action based on the error returned by the drive.
 535 *      For normal I/O that may well include retries. We deal with
 536 *      both new-style (taskfile) and old style command handling here.
 537 *      In the case of taskfile command handling there is work left to
 538 *      do
 539 */
 540 
 541ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
 542{
 543        struct request *rq;
 544        u8 err;
 545
 546        err = ide_dump_status(drive, msg, stat);
 547
 548        if ((rq = HWGROUP(drive)->rq) == NULL)
 549                return ide_stopped;
 550
 551        /* retry only "normal" I/O: */
 552        if (!blk_fs_request(rq)) {
 553                rq->errors = 1;
 554                ide_end_drive_cmd(drive, stat, err);
 555                return ide_stopped;
 556        }
 557
 558        if (rq->rq_disk) {
 559                ide_driver_t *drv;
 560
 561                drv = *(ide_driver_t **)rq->rq_disk->private_data;
 562                return drv->error(drive, rq, stat, err);
 563        } else
 564                return __ide_error(drive, rq, stat, err);
 565}
 566
 567EXPORT_SYMBOL_GPL(ide_error);
 568
 569ide_startstop_t __ide_abort(ide_drive_t *drive, struct request *rq)
 570{
 571        if (drive->media != ide_disk)
 572                rq->errors |= ERROR_RESET;
 573
 574        ide_kill_rq(drive, rq);
 575
 576        return ide_stopped;
 577}
 578
 579EXPORT_SYMBOL_GPL(__ide_abort);
 580
 581/**
 582 *      ide_abort       -       abort pending IDE operations
 583 *      @drive: drive the error occurred on
 584 *      @msg: message to report
 585 *
 586 *      ide_abort kills and cleans up when we are about to do a 
 587 *      host initiated reset on active commands. Longer term we
 588 *      want handlers to have sensible abort handling themselves
 589 *
 590 *      This differs fundamentally from ide_error because in 
 591 *      this case the command is doing just fine when we
 592 *      blow it away.
 593 */
 594 
 595ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
 596{
 597        struct request *rq;
 598
 599        if (drive == NULL || (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, BUSY_STAT, 0);
 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->abort(drive, rq);
 614        } else
 615                return __ide_abort(drive, rq);
 616}
 617
 618/**
 619 *      ide_cmd         -       issue a simple drive command
 620 *      @drive: drive the command is for
 621 *      @cmd: command byte
 622 *      @nsect: sector byte
 623 *      @handler: handler for the command completion
 624 *
 625 *      Issue a simple drive command with interrupts.
 626 *      The drive must be selected beforehand.
 627 */
 628
 629static void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect,
 630                ide_handler_t *handler)
 631{
 632        ide_hwif_t *hwif = HWIF(drive);
 633        if (IDE_CONTROL_REG)
 634                hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */
 635        SELECT_MASK(drive,0);
 636        hwif->OUTB(nsect,IDE_NSECTOR_REG);
 637        ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
 638}
 639
 640/**
 641 *      drive_cmd_intr          -       drive command completion interrupt
 642 *      @drive: drive the completion interrupt occurred on
 643 *
 644 *      drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
 645 *      We do any necessary data reading and then wait for the drive to
 646 *      go non busy. At that point we may read the error data and complete
 647 *      the request
 648 */
 649 
 650static ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
 651{
 652        struct request *rq = HWGROUP(drive)->rq;
 653        ide_hwif_t *hwif = HWIF(drive);
 654        u8 *args = (u8 *) rq->buffer;
 655        u8 stat = hwif->INB(IDE_STATUS_REG);
 656        int retries = 10;
 657
 658        local_irq_enable_in_hardirq();
 659        if (rq->cmd_type == REQ_TYPE_ATA_CMD &&
 660            (stat & DRQ_STAT) && args && args[3]) {
 661                u8 io_32bit = drive->io_32bit;
 662                drive->io_32bit = 0;
 663                hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
 664                drive->io_32bit = io_32bit;
 665                while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
 666                        udelay(100);
 667        }
 668
 669        if (!OK_STAT(stat, READY_STAT, BAD_STAT))
 670                return ide_error(drive, "drive_cmd", stat);
 671                /* calls ide_end_drive_cmd */
 672        ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
 673        return ide_stopped;
 674}
 675
 676static void ide_init_specify_cmd(ide_drive_t *drive, ide_task_t *task)
 677{
 678        task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
 679        task->tfRegister[IDE_SECTOR_OFFSET]  = drive->sect;
 680        task->tfRegister[IDE_LCYL_OFFSET]    = drive->cyl;
 681        task->tfRegister[IDE_HCYL_OFFSET]    = drive->cyl>>8;
 682        task->tfRegister[IDE_SELECT_OFFSET]  = ((drive->head-1)|drive->select.all)&0xBF;
 683        task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SPECIFY;
 684
 685        task->handler = &set_geometry_intr;
 686}
 687
 688static void ide_init_restore_cmd(ide_drive_t *drive, ide_task_t *task)
 689{
 690        task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
 691        task->tfRegister[IDE_COMMAND_OFFSET] = WIN_RESTORE;
 692
 693        task->handler = &recal_intr;
 694}
 695
 696static void ide_init_setmult_cmd(ide_drive_t *drive, ide_task_t *task)
 697{
 698        task->tfRegister[IDE_NSECTOR_OFFSET] = drive->mult_req;
 699        task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SETMULT;
 700
 701        task->handler = &set_multmode_intr;
 702}
 703
 704static ide_startstop_t ide_disk_special(ide_drive_t *drive)
 705{
 706        special_t *s = &drive->special;
 707        ide_task_t args;
 708
 709        memset(&args, 0, sizeof(ide_task_t));
 710        args.command_type = IDE_DRIVE_TASK_NO_DATA;
 711
 712        if (s->b.set_geometry) {
 713                s->b.set_geometry = 0;
 714                ide_init_specify_cmd(drive, &args);
 715        } else if (s->b.recalibrate) {
 716                s->b.recalibrate = 0;
 717                ide_init_restore_cmd(drive, &args);
 718        } else if (s->b.set_multmode) {
 719                s->b.set_multmode = 0;
 720                if (drive->mult_req > drive->id->max_multsect)
 721                        drive->mult_req = drive->id->max_multsect;
 722                ide_init_setmult_cmd(drive, &args);
 723        } else if (s->all) {
 724                int special = s->all;
 725                s->all = 0;
 726                printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
 727                return ide_stopped;
 728        }
 729
 730        do_rw_taskfile(drive, &args);
 731
 732        return ide_started;
 733}
 734
 735/*
 736 * handle HDIO_SET_PIO_MODE ioctl abusers here, eventually it will go away
 737 */
 738static int set_pio_mode_abuse(ide_hwif_t *hwif, u8 req_pio)
 739{
 740        switch (req_pio) {
 741        case 202:
 742        case 201:
 743        case 200:
 744        case 102:
 745        case 101:
 746        case 100:
 747                return (hwif->host_flags & IDE_HFLAG_ABUSE_DMA_MODES) ? 1 : 0;
 748        case 9:
 749        case 8:
 750                return (hwif->host_flags & IDE_HFLAG_ABUSE_PREFETCH) ? 1 : 0;
 751        case 7:
 752        case 6:
 753                return (hwif->host_flags & IDE_HFLAG_ABUSE_FAST_DEVSEL) ? 1 : 0;
 754        default:
 755                return 0;
 756        }
 757}
 758
 759/**
 760 *      do_special              -       issue some special commands
 761 *      @drive: drive the command is for
 762 *
 763 *      do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
 764 *      commands to a drive.  It used to do much more, but has been scaled
 765 *      back.
 766 */
 767
 768static ide_startstop_t do_special (ide_drive_t *drive)
 769{
 770        special_t *s = &drive->special;
 771
 772#ifdef DEBUG
 773        printk("%s: do_special: 0x%02x\n", drive->name, s->all);
 774#endif
 775        if (s->b.set_tune) {
 776                ide_hwif_t *hwif = drive->hwif;
 777                u8 req_pio = drive->tune_req;
 778
 779                s->b.set_tune = 0;
 780
 781                if (set_pio_mode_abuse(drive->hwif, req_pio)) {
 782
 783                        if (hwif->set_pio_mode == NULL)
 784                                return ide_stopped;
 785
 786                        /*
 787                         * take ide_lock for drive->[no_]unmask/[no_]io_32bit
 788                         */
 789                        if (req_pio == 8 || req_pio == 9) {
 790                                unsigned long flags;
 791
 792                                spin_lock_irqsave(&ide_lock, flags);
 793                                hwif->set_pio_mode(drive, req_pio);
 794                                spin_unlock_irqrestore(&ide_lock, flags);
 795                        } else
 796                                hwif->set_pio_mode(drive, req_pio);
 797                } else {
 798                        int keep_dma = drive->using_dma;
 799
 800                        ide_set_pio(drive, req_pio);
 801
 802                        if (hwif->host_flags & IDE_HFLAG_SET_PIO_MODE_KEEP_DMA) {
 803                                if (keep_dma)
 804                                        hwif->ide_dma_on(drive);
 805                        }
 806                }
 807
 808                return ide_stopped;
 809        } else {
 810                if (drive->media == ide_disk)
 811                        return ide_disk_special(drive);
 812
 813                s->all = 0;
 814                drive->mult_req = 0;
 815                return ide_stopped;
 816        }
 817}
 818
 819void ide_map_sg(ide_drive_t *drive, struct request *rq)
 820{
 821        ide_hwif_t *hwif = drive->hwif;
 822        struct scatterlist *sg = hwif->sg_table;
 823
 824        if (hwif->sg_mapped)    /* needed by ide-scsi */
 825                return;
 826
 827        if (rq->cmd_type != REQ_TYPE_ATA_TASKFILE) {
 828                hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
 829        } else {
 830                sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
 831                hwif->sg_nents = 1;
 832        }
 833}
 834
 835EXPORT_SYMBOL_GPL(ide_map_sg);
 836
 837void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
 838{
 839        ide_hwif_t *hwif = drive->hwif;
 840
 841        hwif->nsect = hwif->nleft = rq->nr_sectors;
 842        hwif->cursg_ofs = 0;
 843        hwif->cursg = NULL;
 844}
 845
 846EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
 847
 848/**
 849 *      execute_drive_command   -       issue special drive command
 850 *      @drive: the drive to issue the command on
 851 *      @rq: the request structure holding the command
 852 *
 853 *      execute_drive_cmd() issues a special drive command,  usually 
 854 *      initiated by ioctl() from the external hdparm program. The
 855 *      command can be a drive command, drive task or taskfile 
 856 *      operation. Weirdly you can call it with NULL to wait for
 857 *      all commands to finish. Don't do this as that is due to change
 858 */
 859
 860static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
 861                struct request *rq)
 862{
 863        ide_hwif_t *hwif = HWIF(drive);
 864        if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
 865                ide_task_t *args = rq->special;
 866 
 867                if (!args)
 868                        goto done;
 869
 870                hwif->data_phase = args->data_phase;
 871
 872                switch (hwif->data_phase) {
 873                case TASKFILE_MULTI_OUT:
 874                case TASKFILE_OUT:
 875                case TASKFILE_MULTI_IN:
 876                case TASKFILE_IN:
 877                        ide_init_sg_cmd(drive, rq);
 878                        ide_map_sg(drive, rq);
 879                default:
 880                        break;
 881                }
 882
 883                if (args->tf_out_flags.all != 0) 
 884                        return flagged_taskfile(drive, args);
 885                return do_rw_taskfile(drive, args);
 886        } else if (rq->cmd_type == REQ_TYPE_ATA_TASK) {
 887                u8 *args = rq->buffer;
 888 
 889                if (!args)
 890                        goto done;
 891#ifdef DEBUG
 892                printk("%s: DRIVE_TASK_CMD ", drive->name);
 893                printk("cmd=0x%02x ", args[0]);
 894                printk("fr=0x%02x ", args[1]);
 895                printk("ns=0x%02x ", args[2]);
 896                printk("sc=0x%02x ", args[3]);
 897                printk("lcyl=0x%02x ", args[4]);
 898                printk("hcyl=0x%02x ", args[5]);
 899                printk("sel=0x%02x\n", args[6]);
 900#endif
 901                hwif->OUTB(args[1], IDE_FEATURE_REG);
 902                hwif->OUTB(args[3], IDE_SECTOR_REG);
 903                hwif->OUTB(args[4], IDE_LCYL_REG);
 904                hwif->OUTB(args[5], IDE_HCYL_REG);
 905                hwif->OUTB((args[6] & 0xEF)|drive->select.all, 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
 933done:
 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
 947static 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                if (IDE_CONTROL_REG)
 974                        HWIF(drive)->OUTB(drive->ctl, IDE_CONTROL_REG);
 975                rc = ide_wait_not_busy(HWIF(drive), 100000);
 976                if (rc)
 977                        printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
 978        }
 979}
 980
 981/**
 982 *      start_request   -       start of I/O and command issuing for IDE
 983 *
 984 *      start_request() initiates handling of a new I/O request. It
 985 *      accepts commands and I/O (read/write) requests. It also does
 986 *      the final remapping for weird stuff like EZDrive. Once 
 987 *      device mapper can work sector level the EZDrive stuff can go away
 988 *
 989 *      FIXME: this function needs a rename
 990 */
 991 
 992static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
 993{
 994        ide_startstop_t startstop;
 995        sector_t block;
 996
 997        BUG_ON(!blk_rq_started(rq));
 998
 999#ifdef DEBUG
1000        printk("%s: start_request: current=0x%08lx\n",
1001                HWIF(drive)->name, (unsigned long) rq);
1002#endif
1003
1004        /* bail early if we've exceeded max_failures */
1005        if (drive->max_failures && (drive->failures > drive->max_failures)) {
1006                goto kill_rq;
1007        }
1008
1009        block    = rq->sector;
1010        if (blk_fs_request(rq) &&
1011            (drive->media == ide_disk || drive->media == ide_floppy)) {
1012                block += drive->sect0;
1013        }
1014        /* Yecch - this will shift the entire interval,
1015           possibly killing some innocent following sector */
1016        if (block == 0 && drive->remap_0_to_1 == 1)
1017                block = 1;  /* redirect MBR access to EZ-Drive partn table */
1018
1019        if (blk_pm_request(rq))
1020                ide_check_pm_state(drive, rq);
1021
1022        SELECT_DRIVE(drive);
1023        if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
1024                printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
1025                return startstop;
1026        }
1027        if (!drive->special.all) {
1028                ide_driver_t *drv;
1029
1030                /*
1031                 * We reset the drive so we need to issue a SETFEATURES.
1032                 * Do it _after_ do_special() restored device parameters.
1033                 */
1034                if (drive->current_speed == 0xff)
1035                        ide_config_drive_speed(drive, drive->desired_speed);
1036
1037                if (rq->cmd_type == REQ_TYPE_ATA_CMD ||
1038                    rq->cmd_type == REQ_TYPE_ATA_TASK ||
1039                    rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
1040                        return execute_drive_cmd(drive, rq);
1041                else if (blk_pm_request(rq)) {
1042                        struct request_pm_state *pm = rq->data;
1043#ifdef DEBUG_PM
1044                        printk("%s: start_power_step(step: %d)\n",
1045                                drive->name, rq->pm->pm_step);
1046#endif
1047                        startstop = ide_start_power_step(drive, rq);
1048                        if (startstop == ide_stopped &&
1049                            pm->pm_step == ide_pm_state_completed)
1050                                ide_complete_pm_request(drive, rq);
1051                        return startstop;
1052                }
1053
1054                drv = *(ide_driver_t **)rq->rq_disk->private_data;
1055                return drv->do_request(drive, rq, block);
1056        }
1057        return do_special(drive);
1058kill_rq:
1059        ide_kill_rq(drive, rq);
1060        return ide_stopped;
1061}
1062
1063/**
1064 *      ide_stall_queue         -       pause an IDE device
1065 *      @drive: drive to stall
1066 *      @timeout: time to stall for (jiffies)
1067 *
1068 *      ide_stall_queue() can be used by a drive to give excess bandwidth back
1069 *      to the hwgroup by sleeping for timeout jiffies.
1070 */
1071 
1072void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
1073{
1074        if (timeout > WAIT_WORSTCASE)
1075                timeout = WAIT_WORSTCASE;
1076        drive->sleep = timeout + jiffies;
1077        drive->sleeping = 1;
1078}
1079
1080EXPORT_SYMBOL(ide_stall_queue);
1081
1082#define WAKEUP(drive)   ((drive)->service_start + 2 * (drive)->service_time)
1083
1084/**
1085 *      choose_drive            -       select a drive to service
1086 *      @hwgroup: hardware group to select on
1087 *
1088 *      choose_drive() selects the next drive which will be serviced.
1089 *      This is necessary because the IDE layer can't issue commands
1090 *      to both drives on the same cable, unlike SCSI.
1091 */
1092 
1093static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
1094{
1095        ide_drive_t *drive, *best;
1096
1097repeat: 
1098        best = NULL;
1099        drive = hwgroup->drive;
1100
1101        /*
1102         * drive is doing pre-flush, ordered write, post-flush sequence. even
1103         * though that is 3 requests, it must be seen as a single transaction.
1104         * we must not preempt this drive until that is complete
1105         */
1106        if (blk_queue_flushing(drive->queue)) {
1107                /*
1108                 * small race where queue could get replugged during
1109                 * the 3-request flush cycle, just yank the plug since
1110                 * we want it to finish asap
1111                 */
1112                blk_remove_plug(drive->queue);
1113                return drive;
1114        }
1115
1116        do {
1117                if ((!drive->sleeping || time_after_eq(jiffies, drive->sleep))
1118                    && !elv_queue_empty(drive->queue)) {
1119                        if (!best
1120                         || (drive->sleeping && (!best->sleeping || time_before(drive->sleep, best->sleep)))
1121                         || (!best->sleeping && time_before(WAKEUP(drive), WAKEUP(best))))
1122                        {
1123                                if (!blk_queue_plugged(drive->queue))
1124                                        best = drive;
1125                        }
1126                }
1127        } while ((drive = drive->next) != hwgroup->drive);
1128        if (best && best->nice1 && !best->sleeping && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
1129                long t = (signed long)(WAKEUP(best) - jiffies);
1130                if (t >= WAIT_MIN_SLEEP) {
1131                /*
1132                 * We *may* have some time to spare, but first let's see if
1133                 * someone can potentially benefit from our nice mood today..
1134                 */
1135                        drive = best->next;
1136                        do {
1137                                if (!drive->sleeping
1138                                 && time_before(jiffies - best->service_time, WAKEUP(drive))
1139                                 && time_before(WAKEUP(drive), jiffies + t))
1140                                {
1141                                        ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
1142                                        goto repeat;
1143                                }
1144                        } while ((drive = drive->next) != best);
1145                }
1146        }
1147        return best;
1148}
1149
1150/*
1151 * Issue a new request to a drive from hwgroup
1152 * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
1153 *
1154 * A hwgroup is a serialized group of IDE interfaces.  Usually there is
1155 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
1156 * may have both interfaces in a single hwgroup to "serialize" access.
1157 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
1158 * together into one hwgroup for serialized access.
1159 *
1160 * Note also that several hwgroups can end up sharing a single IRQ,
1161 * possibly along with many other devices.  This is especially common in
1162 * PCI-based systems with off-board IDE controller cards.
1163 *
1164 * The IDE driver uses the single global ide_lock spinlock to protect
1165 * access to the request queues, and to protect the hwgroup->busy flag.
1166 *
1167 * The first thread into the driver for a particular hwgroup sets the
1168 * hwgroup->busy flag to indicate that this hwgroup is now active,
1169 * and then initiates processing of the top request from the request queue.
1170 *
1171 * Other threads attempting entry notice the busy setting, and will simply
1172 * queue their new requests and exit immediately.  Note that hwgroup->busy
1173 * remains set even when the driver is merely awaiting the next interrupt.
1174 * Thus, the meaning is "this hwgroup is busy processing a request".
1175 *
1176 * When processing of a request completes, the completing thread or IRQ-handler
1177 * will start the next request from the queue.  If no more work remains,
1178 * the driver will clear the hwgroup->busy flag and exit.
1179 *
1180 * The ide_lock (spinlock) is used to protect all access to the
1181 * hwgroup->busy flag, but is otherwise not needed for most processing in
1182 * the driver.  This makes the driver much more friendlier to shared IRQs
1183 * than previous designs, while remaining 100% (?) SMP safe and capable.
1184 */
1185static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
1186{
1187        ide_drive_t     *drive;
1188        ide_hwif_t      *hwif;
1189        struct request  *rq;
1190        ide_startstop_t startstop;
1191        int             loops = 0;
1192
1193        /* for atari only: POSSIBLY BROKEN HERE(?) */
1194        ide_get_lock(ide_intr, hwgroup);
1195
1196        /* caller must own ide_lock */
1197        BUG_ON(!irqs_disabled());
1198
1199        while (!hwgroup->busy) {
1200                hwgroup->busy = 1;
1201                drive = choose_drive(hwgroup);
1202                if (drive == NULL) {
1203                        int sleeping = 0;
1204                        unsigned long sleep = 0; /* shut up, gcc */
1205                        hwgroup->rq = NULL;
1206                        drive = hwgroup->drive;
1207                        do {
1208                                if (drive->sleeping && (!sleeping || time_before(drive->sleep, sleep))) {
1209                                        sleeping = 1;
1210                                        sleep = drive->sleep;
1211                                }
1212                        } while ((drive = drive->next) != hwgroup->drive);
1213                        if (sleeping) {
1214                /*
1215                 * Take a short snooze, and then wake up this hwgroup again.
1216                 * This gives other hwgroups on the same a chance to
1217                 * play fairly with us, just in case there are big differences
1218                 * in relative throughputs.. don't want to hog the cpu too much.
1219                 */
1220                                if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
1221                                        sleep = jiffies + WAIT_MIN_SLEEP;
1222#if 1
1223                                if (timer_pending(&hwgroup->timer))
1224                                        printk(KERN_CRIT "ide_set_handler: timer already active\n");
1225#endif
1226                                /* so that ide_timer_expiry knows what to do */
1227                                hwgroup->sleeping = 1;
1228                                hwgroup->req_gen_timer = hwgroup->req_gen;
1229                                mod_timer(&hwgroup->timer, sleep);
1230                                /* we purposely leave hwgroup->busy==1
1231                                 * while sleeping */
1232                        } else {
1233                                /* Ugly, but how can we sleep for the lock
1234                                 * otherwise? perhaps from tq_disk?
1235                                 */
1236
1237                                /* for atari only */
1238                                ide_release_lock();
1239                                hwgroup->busy = 0;
1240                        }
1241
1242                        /* no more work for this hwgroup (for now) */
1243                        return;
1244                }
1245        again:
1246                hwif = HWIF(drive);
1247                if (hwgroup->hwif->sharing_irq &&
1248                    hwif != hwgroup->hwif &&
1249                    hwif->io_ports[IDE_CONTROL_OFFSET]) {
1250                        /* set nIEN for previous hwif */
1251                        SELECT_INTERRUPT(drive);
1252                }
1253                hwgroup->hwif = hwif;
1254                hwgroup->drive = drive;
1255                drive->sleeping = 0;
1256                drive->service_start = jiffies;
1257
1258                if (blk_queue_plugged(drive->queue)) {
1259                        printk(KERN_ERR "ide: huh? queue was plugged!\n");
1260                        break;
1261                }
1262
1263                /*
1264                 * we know that the queue isn't empty, but this can happen
1265                 * if the q->prep_rq_fn() decides to kill a request
1266                 */
1267                rq = elv_next_request(drive->queue);
1268                if (!rq) {
1269                        hwgroup->busy = 0;
1270                        break;
1271                }
1272
1273                /*
1274                 * Sanity: don't accept a request that isn't a PM request
1275                 * if we are currently power managed. This is very important as
1276                 * blk_stop_queue() doesn't prevent the elv_next_request()
1277                 * above to return us whatever is in the queue. Since we call
1278                 * ide_do_request() ourselves, we end up taking requests while
1279                 * the queue is blocked...
1280                 * 
1281                 * We let requests forced at head of queue with ide-preempt
1282                 * though. I hope that doesn't happen too much, hopefully not
1283                 * unless the subdriver triggers such a thing in its own PM
1284                 * state machine.
1285                 *
1286                 * We count how many times we loop here to make sure we service
1287                 * all drives in the hwgroup without looping for ever
1288                 */
1289                if (drive->blocked && !blk_pm_request(rq) && !(rq->cmd_flags & REQ_PREEMPT)) {
1290                        drive = drive->next ? drive->next : hwgroup->drive;
1291                        if (loops++ < 4 && !blk_queue_plugged(drive->queue))
1292                                goto again;
1293                        /* We clear busy, there should be no pending ATA command at this point. */
1294                        hwgroup->busy = 0;
1295                        break;
1296                }
1297
1298                hwgroup->rq = rq;
1299
1300                /*
1301                 * Some systems have trouble with IDE IRQs arriving while
1302                 * the driver is still setting things up.  So, here we disable
1303                 * the IRQ used by this interface while the request is being started.
1304                 * This may look bad at first, but pretty much the same thing
1305                 * happens anyway when any interrupt comes in, IDE or otherwise
1306                 *  -- the kernel masks the IRQ while it is being handled.
1307                 */
1308                if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1309                        disable_irq_nosync(hwif->irq);
1310                spin_unlock(&ide_lock);
1311                local_irq_enable_in_hardirq();
1312                        /* allow other IRQs while we start this request */
1313                startstop = start_request(drive, rq);
1314                spin_lock_irq(&ide_lock);
1315                if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1316                        enable_irq(hwif->irq);
1317                if (startstop == ide_stopped)
1318                        hwgroup->busy = 0;
1319        }
1320}
1321
1322/*
1323 * Passes the stuff to ide_do_request
1324 */
1325void do_ide_request(struct request_queue *q)
1326{
1327        ide_drive_t *drive = q->queuedata;
1328
1329        ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1330}
1331
1332/*
1333 * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1334 * retry the current request in pio mode instead of risking tossing it
1335 * all away
1336 */
1337static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1338{
1339        ide_hwif_t *hwif = HWIF(drive);
1340        struct request *rq;
1341        ide_startstop_t ret = ide_stopped;
1342
1343        /*
1344         * end current dma transaction
1345         */
1346
1347        if (error < 0) {
1348                printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1349                (void)HWIF(drive)->ide_dma_end(drive);
1350                ret = ide_error(drive, "dma timeout error",
1351                                                hwif->INB(IDE_STATUS_REG));
1352        } else {
1353                printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
1354                hwif->dma_timeout(drive);
1355        }
1356
1357        /*
1358         * disable dma for now, but remember that we did so because of
1359         * a timeout -- we'll reenable after we finish this next request
1360         * (or rather the first chunk of it) in pio.
1361         */
1362        drive->retry_pio++;
1363        drive->state = DMA_PIO_RETRY;
1364        hwif->dma_off_quietly(drive);
1365
1366        /*
1367         * un-busy drive etc (hwgroup->busy is cleared on return) and
1368         * make sure request is sane
1369         */
1370        rq = HWGROUP(drive)->rq;
1371
1372        if (!rq)
1373                goto out;
1374
1375        HWGROUP(drive)->rq = NULL;
1376
1377        rq->errors = 0;
1378
1379        if (!rq->bio)
1380                goto out;
1381
1382        rq->sector = rq->bio->bi_sector;
1383        rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1384        rq->hard_cur_sectors = rq->current_nr_sectors;
1385        rq->buffer = bio_data(rq->bio);
1386out:
1387        return ret;
1388}
1389
1390/**
1391 *      ide_timer_expiry        -       handle lack of an IDE interrupt
1392 *      @data: timer callback magic (hwgroup)
1393 *
1394 *      An IDE command has timed out before the expected drive return
1395 *      occurred. At this point we attempt to clean up the current
1396 *      mess. If the current handler includes an expiry handler then
1397 *      we invoke the expiry handler, and providing it is happy the
1398 *      work is done. If that fails we apply generic recovery rules
1399 *      invoking the handler and checking the drive DMA status. We
1400 *      have an excessively incestuous relationship with the DMA
1401 *      logic that wants cleaning up.
1402 */
1403 
1404void ide_timer_expiry (unsigned long data)
1405{
1406        ide_hwgroup_t   *hwgroup = (ide_hwgroup_t *) data;
1407        ide_handler_t   *handler;
1408        ide_expiry_t    *expiry;
1409        unsigned long   flags;
1410        unsigned long   wait = -1;
1411
1412        spin_lock_irqsave(&ide_lock, flags);
1413
1414        if (((handler = hwgroup->handler) == NULL) ||
1415            (hwgroup->req_gen != hwgroup->req_gen_timer)) {
1416                /*
1417                 * Either a marginal timeout occurred
1418                 * (got the interrupt just as timer expired),
1419                 * or we were "sleeping" to give other devices a chance.
1420                 * Either way, we don't really want to complain about anything.
1421                 */
1422                if (hwgroup->sleeping) {
1423                        hwgroup->sleeping = 0;
1424                        hwgroup->busy = 0;
1425                }
1426        } else {
1427                ide_drive_t *drive = hwgroup->drive;
1428                if (!drive) {
1429                        printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1430                        hwgroup->handler = NULL;
1431                } else {
1432                        ide_hwif_t *hwif;
1433                        ide_startstop_t startstop = ide_stopped;
1434                        if (!hwgroup->busy) {
1435                                hwgroup->busy = 1;      /* paranoia */
1436                                printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1437                        }
1438                        if ((expiry = hwgroup->expiry) != NULL) {
1439                                /* continue */
1440                                if ((wait = expiry(drive)) > 0) {
1441                                        /* reset timer */
1442                                        hwgroup->timer.expires  = jiffies + wait;
1443                                        hwgroup->req_gen_timer = hwgroup->req_gen;
1444                                        add_timer(&hwgroup->timer);
1445                                        spin_unlock_irqrestore(&ide_lock, flags);
1446                                        return;
1447                                }
1448                        }
1449                        hwgroup->handler = NULL;
1450                        /*
1451                         * We need to simulate a real interrupt when invoking
1452                         * the handler() function, which means we need to
1453                         * globally mask the specific IRQ:
1454                         */
1455                        spin_unlock(&ide_lock);
1456                        hwif  = HWIF(drive);
1457#if DISABLE_IRQ_NOSYNC
1458                        disable_irq_nosync(hwif->irq);
1459#else
1460                        /* disable_irq_nosync ?? */
1461                        disable_irq(hwif->irq);
1462#endif /* DISABLE_IRQ_NOSYNC */
1463                        /* local CPU only,
1464                         * as if we were handling an interrupt */
1465                        local_irq_disable();
1466                        if (hwgroup->polling) {
1467                                startstop = handler(drive);
1468                        } else if (drive_is_ready(drive)) {
1469                                if (drive->waiting_for_dma)
1470                                        hwgroup->hwif->dma_lost_irq(drive);
1471                                (void)ide_ack_intr(hwif);
1472                                printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1473                                startstop = handler(drive);
1474                        } else {
1475                                if (drive->waiting_for_dma) {
1476                                        startstop = ide_dma_timeout_retry(drive, wait);
1477                                } else
1478                                        startstop =
1479                                        ide_error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1480                        }
1481                        drive->service_time = jiffies - drive->service_start;
1482                        spin_lock_irq(&ide_lock);
1483                        enable_irq(hwif->irq);
1484                        if (startstop == ide_stopped)
1485                                hwgroup->busy = 0;
1486                }
1487        }
1488        ide_do_request(hwgroup, IDE_NO_IRQ);
1489        spin_unlock_irqrestore(&ide_lock, flags);
1490}
1491
1492/**
1493 *      unexpected_intr         -       handle an unexpected IDE interrupt
1494 *      @irq: interrupt line
1495 *      @hwgroup: hwgroup being processed
1496 *
1497 *      There's nothing really useful we can do with an unexpected interrupt,
1498 *      other than reading the status register (to clear it), and logging it.
1499 *      There should be no way that an irq can happen before we're ready for it,
1500 *      so we needn't worry much about losing an "important" interrupt here.
1501 *
1502 *      On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1503 *      the drive enters "idle", "standby", or "sleep" mode, so if the status
1504 *      looks "good", we just ignore the interrupt completely.
1505 *
1506 *      This routine assumes __cli() is in effect when called.
1507 *
1508 *      If an unexpected interrupt happens on irq15 while we are handling irq14
1509 *      and if the two interfaces are "serialized" (CMD640), then it looks like
1510 *      we could screw up by interfering with a new request being set up for 
1511 *      irq15.
1512 *
1513 *      In reality, this is a non-issue.  The new command is not sent unless 
1514 *      the drive is ready to accept one, in which case we know the drive is
1515 *      not trying to interrupt us.  And ide_set_handler() is always invoked
1516 *      before completing the issuance of any new drive command, so we will not
1517 *      be accidentally invoked as a result of any valid command completion
1518 *      interrupt.
1519 *
1520 *      Note that we must walk the entire hwgroup here. We know which hwif
1521 *      is doing the current command, but we don't know which hwif burped
1522 *      mysteriously.
1523 */
1524 
1525static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1526{
1527        u8 stat;
1528        ide_hwif_t *hwif = hwgroup->hwif;
1529
1530        /*
1531         * handle the unexpected interrupt
1532         */
1533        do {
1534                if (hwif->irq == irq) {
1535                        stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1536                        if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1537                                /* Try to not flood the console with msgs */
1538                                static unsigned long last_msgtime, count;
1539                                ++count;
1540                                if (time_after(jiffies, last_msgtime + HZ)) {
1541                                        last_msgtime = jiffies;
1542                                        printk(KERN_ERR "%s%s: unexpected interrupt, "
1543                                                "status=0x%02x, count=%ld\n",
1544                                                hwif->name,
1545                                                (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1546                                }
1547                        }
1548                }
1549        } while ((hwif = hwif->next) != hwgroup->hwif);
1550}
1551
1552/**
1553 *      ide_intr        -       default IDE interrupt handler
1554 *      @irq: interrupt number
1555 *      @dev_id: hwif group
1556 *      @regs: unused weirdness from the kernel irq layer
1557 *
1558 *      This is the default IRQ handler for the IDE layer. You should
1559 *      not need to override it. If you do be aware it is subtle in
1560 *      places
1561 *
1562 *      hwgroup->hwif is the interface in the group currently performing
1563 *      a command. hwgroup->drive is the drive and hwgroup->handler is
1564 *      the IRQ handler to call. As we issue a command the handlers
1565 *      step through multiple states, reassigning the handler to the
1566 *      next step in the process. Unlike a smart SCSI controller IDE
1567 *      expects the main processor to sequence the various transfer
1568 *      stages. We also manage a poll timer to catch up with most
1569 *      timeout situations. There are still a few where the handlers
1570 *      don't ever decide to give up.
1571 *
1572 *      The handler eventually returns ide_stopped to indicate the
1573 *      request completed. At this point we issue the next request
1574 *      on the hwgroup and the process begins again.
1575 */
1576 
1577irqreturn_t ide_intr (int irq, void *dev_id)
1578{
1579        unsigned long flags;
1580        ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1581        ide_hwif_t *hwif;
1582        ide_drive_t *drive;
1583        ide_handler_t *handler;
1584        ide_startstop_t startstop;
1585
1586        spin_lock_irqsave(&ide_lock, flags);
1587        hwif = hwgroup->hwif;
1588
1589        if (!ide_ack_intr(hwif)) {
1590                spin_unlock_irqrestore(&ide_lock, flags);
1591                return IRQ_NONE;
1592        }
1593
1594        if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
1595                /*
1596                 * Not expecting an interrupt from this drive.
1597                 * That means this could be:
1598                 *      (1) an interrupt from another PCI device
1599                 *      sharing the same PCI INT# as us.
1600                 * or   (2) a drive just entered sleep or standby mode,
1601                 *      and is interrupting to let us know.
1602                 * or   (3) a spurious interrupt of unknown origin.
1603                 *
1604                 * For PCI, we cannot tell the difference,
1605                 * so in that case we just ignore it and hope it goes away.
1606                 *
1607                 * FIXME: unexpected_intr should be hwif-> then we can
1608                 * remove all the ifdef PCI crap
1609                 */
1610#ifdef CONFIG_BLK_DEV_IDEPCI
1611                if (hwif->pci_dev && !hwif->pci_dev->vendor)
1612#endif  /* CONFIG_BLK_DEV_IDEPCI */
1613                {
1614                        /*
1615                         * Probably not a shared PCI interrupt,
1616                         * so we can safely try to do something about it:
1617                         */
1618                        unexpected_intr(irq, hwgroup);
1619#ifdef CONFIG_BLK_DEV_IDEPCI
1620                } else {
1621                        /*
1622                         * Whack the status register, just in case
1623                         * we have a leftover pending IRQ.
1624                         */
1625                        (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1626#endif /* CONFIG_BLK_DEV_IDEPCI */
1627                }
1628                spin_unlock_irqrestore(&ide_lock, flags);
1629                return IRQ_NONE;
1630        }
1631        drive = hwgroup->drive;
1632        if (!drive) {
1633                /*
1634                 * This should NEVER happen, and there isn't much
1635                 * we could do about it here.
1636                 *
1637                 * [Note - this can occur if the drive is hot unplugged]
1638                 */
1639                spin_unlock_irqrestore(&ide_lock, flags);
1640                return IRQ_HANDLED;
1641        }
1642        if (!drive_is_ready(drive)) {
1643                /*
1644                 * This happens regularly when we share a PCI IRQ with
1645                 * another device.  Unfortunately, it can also happen
1646                 * with some buggy drives that trigger the IRQ before
1647                 * their status register is up to date.  Hopefully we have
1648                 * enough advance overhead that the latter isn't a problem.
1649                 */
1650                spin_unlock_irqrestore(&ide_lock, flags);
1651                return IRQ_NONE;
1652        }
1653        if (!hwgroup->busy) {
1654                hwgroup->busy = 1;      /* paranoia */
1655                printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1656        }
1657        hwgroup->handler = NULL;
1658        hwgroup->req_gen++;
1659        del_timer(&hwgroup->timer);
1660        spin_unlock(&ide_lock);
1661
1662        /* Some controllers might set DMA INTR no matter DMA or PIO;
1663         * bmdma status might need to be cleared even for
1664         * PIO interrupts to prevent spurious/lost irq.
1665         */
1666        if (hwif->ide_dma_clear_irq && !(drive->waiting_for_dma))
1667                /* ide_dma_end() needs bmdma status for error checking.
1668                 * So, skip clearing bmdma status here and leave it
1669                 * to ide_dma_end() if this is dma interrupt.
1670                 */
1671                hwif->ide_dma_clear_irq(drive);
1672
1673        if (drive->unmask)
1674                local_irq_enable_in_hardirq();
1675        /* service this interrupt, may set handler for next interrupt */
1676        startstop = handler(drive);
1677        spin_lock_irq(&ide_lock);
1678
1679        /*
1680         * Note that handler() may have set things up for another
1681         * interrupt to occur soon, but it cannot happen until
1682         * we exit from this routine, because it will be the
1683         * same irq as is currently being serviced here, and Linux
1684         * won't allow another of the same (on any CPU) until we return.
1685         */
1686        drive->service_time = jiffies - drive->service_start;
1687        if (startstop == ide_stopped) {
1688                if (hwgroup->handler == NULL) { /* paranoia */
1689                        hwgroup->busy = 0;
1690                        ide_do_request(hwgroup, hwif->irq);
1691                } else {
1692                        printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1693                                "on exit\n", drive->name);
1694                }
1695        }
1696        spin_unlock_irqrestore(&ide_lock, flags);
1697        return IRQ_HANDLED;
1698}
1699
1700/**
1701 *      ide_init_drive_cmd      -       initialize a drive command request
1702 *      @rq: request object
1703 *
1704 *      Initialize a request before we fill it in and send it down to
1705 *      ide_do_drive_cmd. Commands must be set up by this function. Right
1706 *      now it doesn't do a lot, but if that changes abusers will have a
1707 *      nasty surprise.
1708 */
1709
1710void ide_init_drive_cmd (struct request *rq)
1711{
1712        memset(rq, 0, sizeof(*rq));
1713        rq->cmd_type = REQ_TYPE_ATA_CMD;
1714        rq->ref_count = 1;
1715}
1716
1717EXPORT_SYMBOL(ide_init_drive_cmd);
1718
1719/**
1720 *      ide_do_drive_cmd        -       issue IDE special command
1721 *      @drive: device to issue command
1722 *      @rq: request to issue
1723 *      @action: action for processing
1724 *
1725 *      This function issues a special IDE device request
1726 *      onto the request queue.
1727 *
1728 *      If action is ide_wait, then the rq is queued at the end of the
1729 *      request queue, and the function sleeps until it has been processed.
1730 *      This is for use when invoked from an ioctl handler.
1731 *
1732 *      If action is ide_preempt, then the rq is queued at the head of
1733 *      the request queue, displacing the currently-being-processed
1734 *      request and this function returns immediately without waiting
1735 *      for the new rq to be completed.  This is VERY DANGEROUS, and is
1736 *      intended for careful use by the ATAPI tape/cdrom driver code.
1737 *
1738 *      If action is ide_end, then the rq is queued at the end of the
1739 *      request queue, and the function returns immediately without waiting
1740 *      for the new rq to be completed. This is again intended for careful
1741 *      use by the ATAPI tape/cdrom driver code.
1742 */
1743 
1744int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1745{
1746        unsigned long flags;
1747        ide_hwgroup_t *hwgroup = HWGROUP(drive);
1748        DECLARE_COMPLETION_ONSTACK(wait);
1749        int where = ELEVATOR_INSERT_BACK, err;
1750        int must_wait = (action == ide_wait || action == ide_head_wait);
1751
1752        rq->errors = 0;
1753
1754        /*
1755         * we need to hold an extra reference to request for safe inspection
1756         * after completion
1757         */
1758        if (must_wait) {
1759                rq->ref_count++;
1760                rq->end_io_data = &wait;
1761                rq->end_io = blk_end_sync_rq;
1762        }
1763
1764        spin_lock_irqsave(&ide_lock, flags);
1765        if (action == ide_preempt)
1766                hwgroup->rq = NULL;
1767        if (action == ide_preempt || action == ide_head_wait) {
1768                where = ELEVATOR_INSERT_FRONT;
1769                rq->cmd_flags |= REQ_PREEMPT;
1770        }
1771        __elv_add_request(drive->queue, rq, where, 0);
1772        ide_do_request(hwgroup, IDE_NO_IRQ);
1773        spin_unlock_irqrestore(&ide_lock, flags);
1774
1775        err = 0;
1776        if (must_wait) {
1777                wait_for_completion(&wait);
1778                if (rq->errors)
1779                        err = -EIO;
1780
1781                blk_put_request(rq);
1782        }
1783
1784        return err;
1785}
1786
1787EXPORT_SYMBOL(ide_do_drive_cmd);
1788
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