drivers/ide/ide-atapi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ATAPI support.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/cdrom.h>
   8 #include <linux/delay.h>
   9 #include <linux/export.h>
  10 #include <linux/ide.h>
  11 #include <linux/scatterlist.h>
  12 #include <linux/gfp.h>
  13
  14 #include <scsi/scsi.h>
  15
  16 #define DRV_NAME "ide-atapi"
  17 #define PFX DRV_NAME ": "
  18
  19 #ifdef DEBUG
  20 #define debug_log(fmt, args...) \
  21         printk(KERN_INFO "ide: " fmt, ## args)
  22 #else
  23 #define debug_log(fmt, args...) do {} while (0)
  24 #endif
  25
  26 #define ATAPI_MIN_CDB_BYTES     12
  27
  28 static inline int dev_is_idecd(ide_drive_t *drive)
  29 {
  30         return drive->media == ide_cdrom || drive->media == ide_optical;
  31 }
  32
  33 /*
  34  * Check whether we can support a device,
  35  * based on the ATAPI IDENTIFY command results.
  36  */
  37 int ide_check_atapi_device(ide_drive_t *drive, const char *s)
  38 {
  39         u16 *id = drive->id;
  40         u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;
  41
  42         *((u16 *)&gcw) = id[ATA_ID_CONFIG];
  43
  44         protocol    = (gcw[1] & 0xC0) >> 6;
  45         device_type =  gcw[1] & 0x1F;
  46         removable   = (gcw[0] & 0x80) >> 7;
  47         drq_type    = (gcw[0] & 0x60) >> 5;
  48         packet_size =  gcw[0] & 0x03;
  49
  50 #ifdef CONFIG_PPC
  51         /* kludge for Apple PowerBook internal zip */
  52         if (drive->media == ide_floppy && device_type == 5 &&
  53             !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
  54             strstr((char *)&id[ATA_ID_PROD], "ZIP"))
  55                 device_type = 0;
  56 #endif
  57
  58         if (protocol != 2)
  59                 printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
  60                         s, drive->name, protocol);
  61         else if ((drive->media == ide_floppy && device_type != 0) ||
  62                  (drive->media == ide_tape && device_type != 1))
  63                 printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
  64                         s, drive->name, device_type);
  65         else if (removable == 0)
  66                 printk(KERN_ERR "%s: %s: the removable flag is not set\n",
  67                         s, drive->name);
  68         else if (drive->media == ide_floppy && drq_type == 3)
  69                 printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
  70                         "supported\n", s, drive->name, drq_type);
  71         else if (packet_size != 0)
  72                 printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
  73                         "bytes\n", s, drive->name, packet_size);
  74         else
  75                 return 1;
  76         return 0;
  77 }
  78 EXPORT_SYMBOL_GPL(ide_check_atapi_device);
  79
  80 void ide_init_pc(struct ide_atapi_pc *pc)
  81 {
  82         memset(pc, 0, sizeof(*pc));
  83 }
  84 EXPORT_SYMBOL_GPL(ide_init_pc);
  85
  86 /*
  87  * Add a special packet command request to the tail of the request queue,
  88  * and wait for it to be serviced.
  89  */
  90 int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
  91                       struct ide_atapi_pc *pc, void *buf, unsigned int bufflen)
  92 {
  93         struct request *rq;
  94         int error;
  95
  96         rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
  97         ide_req(rq)->type = ATA_PRIV_MISC;
  98         ide_req(rq)->special = pc;
  99
 100         if (buf && bufflen) {
 101                 error = blk_rq_map_kern(drive->queue, rq, buf, bufflen,
 102                                         GFP_NOIO);
 103                 if (error)
 104                         goto put_req;
 105         }
 106
 107         memcpy(scsi_req(rq)->cmd, pc->c, 12);
 108         if (drive->media == ide_tape)
 109                 scsi_req(rq)->cmd[13] = REQ_IDETAPE_PC1;
 110         blk_execute_rq(drive->queue, disk, rq, 0);
 111         error = scsi_req(rq)->result ? -EIO : 0;
 112 put_req:
 113         blk_put_request(rq);
 114         return error;
 115 }
 116 EXPORT_SYMBOL_GPL(ide_queue_pc_tail);
 117
 118 int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
 119 {
 120         struct ide_atapi_pc pc;
 121
 122         ide_init_pc(&pc);
 123         pc.c[0] = TEST_UNIT_READY;
 124
 125         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 126 }
 127 EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);
 128
 129 int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
 130 {
 131         struct ide_atapi_pc pc;
 132
 133         ide_init_pc(&pc);
 134         pc.c[0] = START_STOP;
 135         pc.c[4] = start;
 136
 137         if (drive->media == ide_tape)
 138                 pc.flags |= PC_FLAG_WAIT_FOR_DSC;
 139
 140         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 141 }
 142 EXPORT_SYMBOL_GPL(ide_do_start_stop);
 143
 144 int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
 145 {
 146         struct ide_atapi_pc pc;
 147
 148         if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
 149                 return 0;
 150
 151         ide_init_pc(&pc);
 152         pc.c[0] = ALLOW_MEDIUM_REMOVAL;
 153         pc.c[4] = on;
 154
 155         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 156 }
 157 EXPORT_SYMBOL_GPL(ide_set_media_lock);
 158
 159 void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
 160 {
 161         ide_init_pc(pc);
 162         pc->c[0] = REQUEST_SENSE;
 163         if (drive->media == ide_floppy) {
 164                 pc->c[4] = 255;
 165                 pc->req_xfer = 18;
 166         } else {
 167                 pc->c[4] = 20;
 168                 pc->req_xfer = 20;
 169         }
 170 }
 171 EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);
 172
 173 void ide_prep_sense(ide_drive_t *drive, struct request *rq)
 174 {
 175         struct request_sense *sense = &drive->sense_data;
 176         struct request *sense_rq;
 177         struct scsi_request *req;
 178         unsigned int cmd_len, sense_len;
 179         int err;
 180
 181         switch (drive->media) {
 182         case ide_floppy:
 183                 cmd_len = 255;
 184                 sense_len = 18;
 185                 break;
 186         case ide_tape:
 187                 cmd_len = 20;
 188                 sense_len = 20;
 189                 break;
 190         default:
 191                 cmd_len = 18;
 192                 sense_len = 18;
 193         }
 194
 195         BUG_ON(sense_len > sizeof(*sense));
 196
 197         if (ata_sense_request(rq) || drive->sense_rq_armed)
 198                 return;
 199
 200         sense_rq = drive->sense_rq;
 201         if (!sense_rq) {
 202                 sense_rq = blk_mq_alloc_request(drive->queue, REQ_OP_DRV_IN,
 203                                         BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
 204                 drive->sense_rq = sense_rq;
 205         }
 206         req = scsi_req(sense_rq);
 207
 208         memset(sense, 0, sizeof(*sense));
 209
 210         scsi_req_init(req);
 211
 212         err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len,
 213                               GFP_NOIO);
 214         if (unlikely(err)) {
 215                 if (printk_ratelimit())
 216                         printk(KERN_WARNING PFX "%s: failed to map sense "
 217                                             "buffer\n", drive->name);
 218                 blk_mq_free_request(sense_rq);
 219                 drive->sense_rq = NULL;
 220                 return;
 221         }
 222
 223         sense_rq->rq_disk = rq->rq_disk;
 224         sense_rq->cmd_flags = REQ_OP_DRV_IN;
 225         ide_req(sense_rq)->type = ATA_PRIV_SENSE;
 226
 227         req->cmd[0] = GPCMD_REQUEST_SENSE;
 228         req->cmd[4] = cmd_len;
 229         if (drive->media == ide_tape)
 230                 req->cmd[13] = REQ_IDETAPE_PC1;
 231
 232         drive->sense_rq_armed = true;
 233 }
 234 EXPORT_SYMBOL_GPL(ide_prep_sense);
 235
 236 int ide_queue_sense_rq(ide_drive_t *drive, void *special)
 237 {
 238         ide_hwif_t *hwif = drive->hwif;
 239         struct request *sense_rq;
 240         unsigned long flags;
 241
 242         spin_lock_irqsave(&hwif->lock, flags);
 243
 244         /* deferred failure from ide_prep_sense() */
 245         if (!drive->sense_rq_armed) {
 246                 printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
 247                        drive->name);
 248                 spin_unlock_irqrestore(&hwif->lock, flags);
 249                 return -ENOMEM;
 250         }
 251
 252         sense_rq = drive->sense_rq;
 253         ide_req(sense_rq)->special = special;
 254         drive->sense_rq_armed = false;
 255
 256         drive->hwif->rq = NULL;
 257
 258         ide_insert_request_head(drive, sense_rq);
 259         spin_unlock_irqrestore(&hwif->lock, flags);
 260         return 0;
 261 }
 262 EXPORT_SYMBOL_GPL(ide_queue_sense_rq);
 263
 264 /*
 265  * Called when an error was detected during the last packet command.
 266  * We queue a request sense packet command at the head of the request
 267  * queue.
 268  */
 269 void ide_retry_pc(ide_drive_t *drive)
 270 {
 271         struct request *failed_rq = drive->hwif->rq;
 272         struct request *sense_rq = drive->sense_rq;
 273         struct ide_atapi_pc *pc = &drive->request_sense_pc;
 274
 275         (void)ide_read_error(drive);
 276
 277         /* init pc from sense_rq */
 278         ide_init_pc(pc);
 279         memcpy(pc->c, scsi_req(sense_rq)->cmd, 12);
 280
 281         if (drive->media == ide_tape)
 282                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 283
 284         /*
 285          * Push back the failed request and put request sense on top
 286          * of it.  The failed command will be retried after sense data
 287          * is acquired.
 288          */
 289         drive->hwif->rq = NULL;
 290         ide_requeue_and_plug(drive, failed_rq);
 291         if (ide_queue_sense_rq(drive, pc))
 292                 ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(failed_rq));
 293 }
 294 EXPORT_SYMBOL_GPL(ide_retry_pc);
 295
 296 int ide_cd_expiry(ide_drive_t *drive)
 297 {
 298         struct request *rq = drive->hwif->rq;
 299         unsigned long wait = 0;
 300
 301         debug_log("%s: scsi_req(rq)->cmd[0]: 0x%x\n", __func__, scsi_req(rq)->cmd[0]);
 302
 303         /*
 304          * Some commands are *slow* and normally take a long time to complete.
 305          * Usually we can use the ATAPI "disconnect" to bypass this, but not all
 306          * commands/drives support that. Let ide_timer_expiry keep polling us
 307          * for these.
 308          */
 309         switch (scsi_req(rq)->cmd[0]) {
 310         case GPCMD_BLANK:
 311         case GPCMD_FORMAT_UNIT:
 312         case GPCMD_RESERVE_RZONE_TRACK:
 313         case GPCMD_CLOSE_TRACK:
 314         case GPCMD_FLUSH_CACHE:
 315                 wait = ATAPI_WAIT_PC;
 316                 break;
 317         default:
 318                 if (!(rq->rq_flags & RQF_QUIET))
 319                         printk(KERN_INFO PFX "cmd 0x%x timed out\n",
 320                                          scsi_req(rq)->cmd[0]);
 321                 wait = 0;
 322                 break;
 323         }
 324         return wait;
 325 }
 326 EXPORT_SYMBOL_GPL(ide_cd_expiry);
 327
 328 int ide_cd_get_xferlen(struct request *rq)
 329 {
 330         switch (req_op(rq)) {
 331         default:
 332                 return 32768;
 333         case REQ_OP_SCSI_IN:
 334         case REQ_OP_SCSI_OUT:
 335                 return blk_rq_bytes(rq);
 336         case REQ_OP_DRV_IN:
 337         case REQ_OP_DRV_OUT:
 338                 switch (ide_req(rq)->type) {
 339                 case ATA_PRIV_PC:
 340                 case ATA_PRIV_SENSE:
 341                         return blk_rq_bytes(rq);
 342                 default:
 343                         return 0;
 344                 }
 345         }
 346 }
 347 EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
 348
 349 void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
 350 {
 351         struct ide_taskfile tf;
 352
 353         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
 354                                      IDE_VALID_LBAM | IDE_VALID_LBAH);
 355
 356         *bcount = (tf.lbah << 8) | tf.lbam;
 357         *ireason = tf.nsect & 3;
 358 }
 359 EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);
 360
 361 /*
 362  * Check the contents of the interrupt reason register and attempt to recover if
 363  * there are problems.
 364  *
 365  * Returns:
 366  * - 0 if everything's ok
 367  * - 1 if the request has to be terminated.
 368  */
 369 int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
 370                       int ireason, int rw)
 371 {
 372         ide_hwif_t *hwif = drive->hwif;
 373
 374         debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);
 375
 376         if (ireason == (!rw << 1))
 377                 return 0;
 378         else if (ireason == (rw << 1)) {
 379                 printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
 380                                 drive->name, __func__);
 381
 382                 if (dev_is_idecd(drive))
 383                         ide_pad_transfer(drive, rw, len);
 384         } else if (!rw && ireason == ATAPI_COD) {
 385                 if (dev_is_idecd(drive)) {
 386                         /*
 387                          * Some drives (ASUS) seem to tell us that status info
 388                          * is available.  Just get it and ignore.
 389                          */
 390                         (void)hwif->tp_ops->read_status(hwif);
 391                         return 0;
 392                 }
 393         } else {
 394                 if (ireason & ATAPI_COD)
 395                         printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
 396                                         __func__);
 397
 398                 /* drive wants a command packet, or invalid ireason... */
 399                 printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
 400                                 drive->name, __func__, ireason);
 401         }
 402
 403         if (dev_is_idecd(drive) && ata_pc_request(rq))
 404                 rq->rq_flags |= RQF_FAILED;
 405
 406         return 1;
 407 }
 408 EXPORT_SYMBOL_GPL(ide_check_ireason);
 409
 410 /*
 411  * This is the usual interrupt handler which will be called during a packet
 412  * command.  We will transfer some of the data (as requested by the drive)
 413  * and will re-point interrupt handler to us.
 414  */
 415 static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 416 {
 417         struct ide_atapi_pc *pc = drive->pc;
 418         ide_hwif_t *hwif = drive->hwif;
 419         struct ide_cmd *cmd = &hwif->cmd;
 420         struct request *rq = hwif->rq;
 421         const struct ide_tp_ops *tp_ops = hwif->tp_ops;
 422         unsigned int timeout, done;
 423         u16 bcount;
 424         u8 stat, ireason, dsc = 0;
 425         u8 write = !!(pc->flags & PC_FLAG_WRITING);
 426
 427         debug_log("Enter %s - interrupt handler\n", __func__);
 428
 429         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 430                                                : WAIT_TAPE_CMD;
 431
 432         /* Clear the interrupt */
 433         stat = tp_ops->read_status(hwif);
 434
 435         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 436                 int rc;
 437
 438                 drive->waiting_for_dma = 0;
 439                 rc = hwif->dma_ops->dma_end(drive);
 440                 ide_dma_unmap_sg(drive, cmd);
 441
 442                 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
 443                         if (drive->media == ide_floppy)
 444                                 printk(KERN_ERR PFX "%s: DMA %s error\n",
 445                                         drive->name, rq_data_dir(pc->rq)
 446                                                      ? "write" : "read");
 447                         pc->flags |= PC_FLAG_DMA_ERROR;
 448                 } else
 449                         scsi_req(rq)->resid_len = 0;
 450                 debug_log("%s: DMA finished\n", drive->name);
 451         }
 452
 453         /* No more interrupts */
 454         if ((stat & ATA_DRQ) == 0) {
 455                 int uptodate;
 456                 blk_status_t error;
 457
 458                 debug_log("Packet command completed, %d bytes transferred\n",
 459                           blk_rq_bytes(rq));
 460
 461                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 462
 463                 local_irq_enable_in_hardirq();
 464
 465                 if (drive->media == ide_tape &&
 466                     (stat & ATA_ERR) && scsi_req(rq)->cmd[0] == REQUEST_SENSE)
 467                         stat &= ~ATA_ERR;
 468
 469                 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
 470                         /* Error detected */
 471                         debug_log("%s: I/O error\n", drive->name);
 472
 473                         if (drive->media != ide_tape)
 474                                 scsi_req(pc->rq)->result++;
 475
 476                         if (scsi_req(rq)->cmd[0] == REQUEST_SENSE) {
 477                                 printk(KERN_ERR PFX "%s: I/O error in request "
 478                                                 "sense command\n", drive->name);
 479                                 return ide_do_reset(drive);
 480                         }
 481
 482                         debug_log("[cmd %x]: check condition\n", scsi_req(rq)->cmd[0]);
 483
 484                         /* Retry operation */
 485                         ide_retry_pc(drive);
 486
 487                         /* queued, but not started */
 488                         return ide_stopped;
 489                 }
 490                 pc->error = 0;
 491
 492                 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
 493                         dsc = 1;
 494
 495                 /*
 496                  * ->pc_callback() might change rq->data_len for
 497                  * residual count, cache total length.
 498                  */
 499                 done = blk_rq_bytes(rq);
 500
 501                 /* Command finished - Call the callback function */
 502                 uptodate = drive->pc_callback(drive, dsc);
 503
 504                 if (uptodate == 0)
 505                         drive->failed_pc = NULL;
 506
 507                 if (ata_misc_request(rq)) {
 508                         scsi_req(rq)->result = 0;
 509                         error = BLK_STS_OK;
 510                 } else {
 511
 512                         if (blk_rq_is_passthrough(rq) && uptodate <= 0) {
 513                                 if (scsi_req(rq)->result == 0)
 514                                         scsi_req(rq)->result = -EIO;
 515                         }
 516
 517                         error = uptodate ? BLK_STS_OK : BLK_STS_IOERR;
 518                 }
 519
 520                 ide_complete_rq(drive, error, blk_rq_bytes(rq));
 521                 return ide_stopped;
 522         }
 523
 524         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 525                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 526                 printk(KERN_ERR PFX "%s: The device wants to issue more "
 527                                 "interrupts in DMA mode\n", drive->name);
 528                 ide_dma_off(drive);
 529                 return ide_do_reset(drive);
 530         }
 531
 532         /* Get the number of bytes to transfer on this interrupt. */
 533         ide_read_bcount_and_ireason(drive, &bcount, &ireason);
 534
 535         if (ide_check_ireason(drive, rq, bcount, ireason, write))
 536                 return ide_do_reset(drive);
 537
 538         done = min_t(unsigned int, bcount, cmd->nleft);
 539         ide_pio_bytes(drive, cmd, write, done);
 540
 541         /* Update transferred byte count */
 542         scsi_req(rq)->resid_len -= done;
 543
 544         bcount -= done;
 545
 546         if (bcount)
 547                 ide_pad_transfer(drive, write, bcount);
 548
 549         debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
 550                   scsi_req(rq)->cmd[0], done, bcount, scsi_req(rq)->resid_len);
 551
 552         /* And set the interrupt handler again */
 553         ide_set_handler(drive, ide_pc_intr, timeout);
 554         return ide_started;
 555 }
 556
 557 static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
 558                                 u16 bcount, u8 dma)
 559 {
 560         cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
 561         cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
 562                             IDE_VALID_FEATURE | valid_tf;
 563         cmd->tf.command = ATA_CMD_PACKET;
 564         cmd->tf.feature = dma;          /* Use PIO/DMA */
 565         cmd->tf.lbam    = bcount & 0xff;
 566         cmd->tf.lbah    = (bcount >> 8) & 0xff;
 567 }
 568
 569 static u8 ide_read_ireason(ide_drive_t *drive)
 570 {
 571         struct ide_taskfile tf;
 572
 573         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);
 574
 575         return tf.nsect & 3;
 576 }
 577
 578 static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
 579 {
 580         int retries = 100;
 581
 582         while (retries-- && ((ireason & ATAPI_COD) == 0 ||
 583                 (ireason & ATAPI_IO))) {
 584                 printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
 585                                 "a packet command, retrying\n", drive->name);
 586                 udelay(100);
 587                 ireason = ide_read_ireason(drive);
 588                 if (retries == 0) {
 589                         printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
 590                                         " a packet command, ignoring\n",
 591                                         drive->name);
 592                         ireason |= ATAPI_COD;
 593                         ireason &= ~ATAPI_IO;
 594                 }
 595         }
 596
 597         return ireason;
 598 }
 599
 600 static int ide_delayed_transfer_pc(ide_drive_t *drive)
 601 {
 602         /* Send the actual packet */
 603         drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);
 604
 605         /* Timeout for the packet command */
 606         return WAIT_FLOPPY_CMD;
 607 }
 608
 609 static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
 610 {
 611         struct ide_atapi_pc *pc;
 612         ide_hwif_t *hwif = drive->hwif;
 613         struct request *rq = hwif->rq;
 614         ide_expiry_t *expiry;
 615         unsigned int timeout;
 616         int cmd_len;
 617         ide_startstop_t startstop;
 618         u8 ireason;
 619
 620         if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
 621                 printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
 622                                 "DRQ isn't asserted\n", drive->name);
 623                 return startstop;
 624         }
 625
 626         if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
 627                 if (drive->dma)
 628                         drive->waiting_for_dma = 1;
 629         }
 630
 631         if (dev_is_idecd(drive)) {
 632                 /* ATAPI commands get padded out to 12 bytes minimum */
 633                 cmd_len = COMMAND_SIZE(scsi_req(rq)->cmd[0]);
 634                 if (cmd_len < ATAPI_MIN_CDB_BYTES)
 635                         cmd_len = ATAPI_MIN_CDB_BYTES;
 636
 637                 timeout = rq->timeout;
 638                 expiry  = ide_cd_expiry;
 639         } else {
 640                 pc = drive->pc;
 641
 642                 cmd_len = ATAPI_MIN_CDB_BYTES;
 643
 644                 /*
 645                  * If necessary schedule the packet transfer to occur 'timeout'
 646                  * milliseconds later in ide_delayed_transfer_pc() after the
 647                  * device says it's ready for a packet.
 648                  */
 649                 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
 650                         timeout = drive->pc_delay;
 651                         expiry = &ide_delayed_transfer_pc;
 652                 } else {
 653                         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 654                                                                : WAIT_TAPE_CMD;
 655                         expiry = NULL;
 656                 }
 657
 658                 ireason = ide_read_ireason(drive);
 659                 if (drive->media == ide_tape)
 660                         ireason = ide_wait_ireason(drive, ireason);
 661
 662                 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
 663                         printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
 664                                 "issuing a packet command\n", drive->name);
 665
 666                         return ide_do_reset(drive);
 667                 }
 668         }
 669
 670         hwif->expiry = expiry;
 671
 672         /* Set the interrupt routine */
 673         ide_set_handler(drive,
 674                         (dev_is_idecd(drive) ? drive->irq_handler
 675                                              : ide_pc_intr),
 676                         timeout);
 677
 678         /* Send the actual packet */
 679         if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
 680                 hwif->tp_ops->output_data(drive, NULL, scsi_req(rq)->cmd, cmd_len);
 681
 682         /* Begin DMA, if necessary */
 683         if (dev_is_idecd(drive)) {
 684                 if (drive->dma)
 685                         hwif->dma_ops->dma_start(drive);
 686         } else {
 687                 if (pc->flags & PC_FLAG_DMA_OK) {
 688                         pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
 689                         hwif->dma_ops->dma_start(drive);
 690                 }
 691         }
 692
 693         return ide_started;
 694 }
 695
 696 ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
 697 {
 698         struct ide_atapi_pc *pc;
 699         ide_hwif_t *hwif = drive->hwif;
 700         ide_expiry_t *expiry = NULL;
 701         struct request *rq = hwif->rq;
 702         unsigned int timeout, bytes;
 703         u16 bcount;
 704         u8 valid_tf;
 705         u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);
 706
 707         if (dev_is_idecd(drive)) {
 708                 valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
 709                 bcount = ide_cd_get_xferlen(rq);
 710                 expiry = ide_cd_expiry;
 711                 timeout = ATAPI_WAIT_PC;
 712
 713                 if (drive->dma)
 714                         drive->dma = !ide_dma_prepare(drive, cmd);
 715         } else {
 716                 pc = drive->pc;
 717
 718                 valid_tf = IDE_VALID_DEVICE;
 719                 bytes = blk_rq_bytes(rq);
 720                 bcount = ((drive->media == ide_tape) ? bytes
 721                                                      : min_t(unsigned int,
 722                                                              bytes, 63 * 1024));
 723
 724                 /* We haven't transferred any data yet */
 725                 scsi_req(rq)->resid_len = bcount;
 726
 727                 if (pc->flags & PC_FLAG_DMA_ERROR) {
 728                         pc->flags &= ~PC_FLAG_DMA_ERROR;
 729                         ide_dma_off(drive);
 730                 }
 731
 732                 if (pc->flags & PC_FLAG_DMA_OK)
 733                         drive->dma = !ide_dma_prepare(drive, cmd);
 734
 735                 if (!drive->dma)
 736                         pc->flags &= ~PC_FLAG_DMA_OK;
 737
 738                 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 739                                                        : WAIT_TAPE_CMD;
 740         }
 741
 742         ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);
 743
 744         (void)do_rw_taskfile(drive, cmd);
 745
 746         if (drq_int) {
 747                 if (drive->dma)
 748                         drive->waiting_for_dma = 0;
 749                 hwif->expiry = expiry;
 750         }
 751
 752         ide_execute_command(drive, cmd, ide_transfer_pc, timeout);
 753
 754         return drq_int ? ide_started : ide_transfer_pc(drive);
 755 }
 756 EXPORT_SYMBOL_GPL(ide_issue_pc);