drivers/ide/ide-tape.c

   1 /*
   2  * IDE ATAPI streaming tape driver.
   3  *
   4  * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
   5  * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
   6  *
   7  * This driver was constructed as a student project in the software laboratory
   8  * of the faculty of electrical engineering in the Technion - Israel's
   9  * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
  10  *
  11  * It is hereby placed under the terms of the GNU general public license.
  12  * (See linux/COPYING).
  13  *
  14  * For a historical changelog see
  15  * Documentation/ide/ChangeLog.ide-tape.1995-2002
  16  */
  17
  18 #define DRV_NAME "ide-tape"
  19
  20 #define IDETAPE_VERSION "1.20"
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/kernel.h>
  26 #include <linux/delay.h>
  27 #include <linux/timer.h>
  28 #include <linux/mm.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/major.h>
  32 #include <linux/errno.h>
  33 #include <linux/genhd.h>
  34 #include <linux/slab.h>
  35 #include <linux/pci.h>
  36 #include <linux/ide.h>
  37 #include <linux/smp_lock.h>
  38 #include <linux/completion.h>
  39 #include <linux/bitops.h>
  40 #include <linux/mutex.h>
  41 #include <scsi/scsi.h>
  42
  43 #include <asm/byteorder.h>
  44 #include <linux/irq.h>
  45 #include <linux/uaccess.h>
  46 #include <linux/io.h>
  47 #include <asm/unaligned.h>
  48 #include <linux/mtio.h>
  49
  50 enum {
  51         /* output errors only */
  52         DBG_ERR =               (1 << 0),
  53         /* output all sense key/asc */
  54         DBG_SENSE =             (1 << 1),
  55         /* info regarding all chrdev-related procedures */
  56         DBG_CHRDEV =            (1 << 2),
  57         /* all remaining procedures */
  58         DBG_PROCS =             (1 << 3),
  59 };
  60
  61 /* define to see debug info */
  62 #define IDETAPE_DEBUG_LOG               0
  63
  64 #if IDETAPE_DEBUG_LOG
  65 #define debug_log(lvl, fmt, args...)                    \
  66 {                                                       \
  67         if (tape->debug_mask & lvl)                     \
  68         printk(KERN_INFO "ide-tape: " fmt, ## args);    \
  69 }
  70 #else
  71 #define debug_log(lvl, fmt, args...) do {} while (0)
  72 #endif
  73
  74 /**************************** Tunable parameters *****************************/
  75 /*
  76  * After each failed packet command we issue a request sense command and retry
  77  * the packet command IDETAPE_MAX_PC_RETRIES times.
  78  *
  79  * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
  80  */
  81 #define IDETAPE_MAX_PC_RETRIES          3
  82
  83 /*
  84  * The following parameter is used to select the point in the internal tape fifo
  85  * in which we will start to refill the buffer. Decreasing the following
  86  * parameter will improve the system's latency and interactive response, while
  87  * using a high value might improve system throughput.
  88  */
  89 #define IDETAPE_FIFO_THRESHOLD          2
  90
  91 /*
  92  * DSC polling parameters.
  93  *
  94  * Polling for DSC (a single bit in the status register) is a very important
  95  * function in ide-tape. There are two cases in which we poll for DSC:
  96  *
  97  * 1. Before a read/write packet command, to ensure that we can transfer data
  98  * from/to the tape's data buffers, without causing an actual media access.
  99  * In case the tape is not ready yet, we take out our request from the device
 100  * request queue, so that ide.c could service requests from the other device
 101  * on the same interface in the meantime.
 102  *
 103  * 2. After the successful initialization of a "media access packet command",
 104  * which is a command that can take a long time to complete (the interval can
 105  * range from several seconds to even an hour). Again, we postpone our request
 106  * in the middle to free the bus for the other device. The polling frequency
 107  * here should be lower than the read/write frequency since those media access
 108  * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
 109  * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
 110  * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
 111  *
 112  * We also set a timeout for the timer, in case something goes wrong. The
 113  * timeout should be longer then the maximum execution time of a tape operation.
 114  */
 115
 116 /* DSC timings. */
 117 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 118 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 119 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 120 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 121 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 122 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 123 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 124
 125 /*************************** End of tunable parameters ***********************/
 126
 127 /* tape directions */
 128 enum {
 129         IDETAPE_DIR_NONE  = (1 << 0),
 130         IDETAPE_DIR_READ  = (1 << 1),
 131         IDETAPE_DIR_WRITE = (1 << 2),
 132 };
 133
 134 struct idetape_bh {
 135         u32 b_size;
 136         atomic_t b_count;
 137         struct idetape_bh *b_reqnext;
 138         char *b_data;
 139 };
 140
 141 /* Tape door status */
 142 #define DOOR_UNLOCKED                   0
 143 #define DOOR_LOCKED                     1
 144 #define DOOR_EXPLICITLY_LOCKED          2
 145
 146 /* Some defines for the SPACE command */
 147 #define IDETAPE_SPACE_OVER_FILEMARK     1
 148 #define IDETAPE_SPACE_TO_EOD            3
 149
 150 /* Some defines for the LOAD UNLOAD command */
 151 #define IDETAPE_LU_LOAD_MASK            1
 152 #define IDETAPE_LU_RETENSION_MASK       2
 153 #define IDETAPE_LU_EOT_MASK             4
 154
 155 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
 156 #define IDETAPE_BLOCK_DESCRIPTOR        0
 157 #define IDETAPE_CAPABILITIES_PAGE       0x2a
 158
 159 /*
 160  * Most of our global data which we need to save even as we leave the driver due
 161  * to an interrupt or a timer event is stored in the struct defined below.
 162  */
 163 typedef struct ide_tape_obj {
 164         ide_drive_t             *drive;
 165         struct ide_driver       *driver;
 166         struct gendisk          *disk;
 167         struct device           dev;
 168
 169         /* used by REQ_IDETAPE_{READ,WRITE} requests */
 170         struct ide_atapi_pc queued_pc;
 171
 172         /*
 173          * DSC polling variables.
 174          *
 175          * While polling for DSC we use postponed_rq to postpone the current
 176          * request so that ide.c will be able to service pending requests on the
 177          * other device. Note that at most we will have only one DSC (usually
 178          * data transfer) request in the device request queue.
 179          */
 180         struct request *postponed_rq;
 181         /* The time in which we started polling for DSC */
 182         unsigned long dsc_polling_start;
 183         /* Timer used to poll for dsc */
 184         struct timer_list dsc_timer;
 185         /* Read/Write dsc polling frequency */
 186         unsigned long best_dsc_rw_freq;
 187         unsigned long dsc_poll_freq;
 188         unsigned long dsc_timeout;
 189
 190         /* Read position information */
 191         u8 partition;
 192         /* Current block */
 193         unsigned int first_frame;
 194
 195         /* Last error information */
 196         u8 sense_key, asc, ascq;
 197
 198         /* Character device operation */
 199         unsigned int minor;
 200         /* device name */
 201         char name[4];
 202         /* Current character device data transfer direction */
 203         u8 chrdev_dir;
 204
 205         /* tape block size, usually 512 or 1024 bytes */
 206         unsigned short blk_size;
 207         int user_bs_factor;
 208
 209         /* Copy of the tape's Capabilities and Mechanical Page */
 210         u8 caps[20];
 211
 212         /*
 213          * Active data transfer request parameters.
 214          *
 215          * At most, there is only one ide-tape originated data transfer request
 216          * in the device request queue. This allows ide.c to easily service
 217          * requests from the other device when we postpone our active request.
 218          */
 219
 220         /* Data buffer size chosen based on the tape's recommendation */
 221         int buffer_size;
 222         /* merge buffer */
 223         struct idetape_bh *merge_bh;
 224         /* size of the merge buffer */
 225         int merge_bh_size;
 226         /* pointer to current buffer head within the merge buffer */
 227         struct idetape_bh *bh;
 228         char *b_data;
 229         int b_count;
 230
 231         int pages_per_buffer;
 232         /* Wasted space in each stage */
 233         int excess_bh_size;
 234
 235         /* Measures average tape speed */
 236         unsigned long avg_time;
 237         int avg_size;
 238         int avg_speed;
 239
 240         /* the door is currently locked */
 241         int door_locked;
 242         /* the tape hardware is write protected */
 243         char drv_write_prot;
 244         /* the tape is write protected (hardware or opened as read-only) */
 245         char write_prot;
 246
 247         u32 debug_mask;
 248 } idetape_tape_t;
 249
 250 static DEFINE_MUTEX(idetape_ref_mutex);
 251
 252 static struct class *idetape_sysfs_class;
 253
 254 static void ide_tape_release(struct device *);
 255
 256 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
 257 {
 258         struct ide_tape_obj *tape = NULL;
 259
 260         mutex_lock(&idetape_ref_mutex);
 261         tape = ide_drv_g(disk, ide_tape_obj);
 262         if (tape) {
 263                 if (ide_device_get(tape->drive))
 264                         tape = NULL;
 265                 else
 266                         get_device(&tape->dev);
 267         }
 268         mutex_unlock(&idetape_ref_mutex);
 269         return tape;
 270 }
 271
 272 static void ide_tape_put(struct ide_tape_obj *tape)
 273 {
 274         ide_drive_t *drive = tape->drive;
 275
 276         mutex_lock(&idetape_ref_mutex);
 277         put_device(&tape->dev);
 278         ide_device_put(drive);
 279         mutex_unlock(&idetape_ref_mutex);
 280 }
 281
 282 /*
 283  * The variables below are used for the character device interface. Additional
 284  * state variables are defined in our ide_drive_t structure.
 285  */
 286 static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
 287
 288 static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
 289 {
 290         struct ide_tape_obj *tape = NULL;
 291
 292         mutex_lock(&idetape_ref_mutex);
 293         tape = idetape_devs[i];
 294         if (tape)
 295                 get_device(&tape->dev);
 296         mutex_unlock(&idetape_ref_mutex);
 297         return tape;
 298 }
 299
 300 static int idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
 301                                   unsigned int bcount)
 302 {
 303         struct idetape_bh *bh = pc->bh;
 304         int count;
 305
 306         while (bcount) {
 307                 if (bh == NULL)
 308                         break;
 309                 count = min(
 310                         (unsigned int)(bh->b_size - atomic_read(&bh->b_count)),
 311                         bcount);
 312                 drive->hwif->tp_ops->input_data(drive, NULL, bh->b_data +
 313                                         atomic_read(&bh->b_count), count);
 314                 bcount -= count;
 315                 atomic_add(count, &bh->b_count);
 316                 if (atomic_read(&bh->b_count) == bh->b_size) {
 317                         bh = bh->b_reqnext;
 318                         if (bh)
 319                                 atomic_set(&bh->b_count, 0);
 320                 }
 321         }
 322
 323         pc->bh = bh;
 324
 325         return bcount;
 326 }
 327
 328 static int idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
 329                                    unsigned int bcount)
 330 {
 331         struct idetape_bh *bh = pc->bh;
 332         int count;
 333
 334         while (bcount) {
 335                 if (bh == NULL)
 336                         break;
 337                 count = min((unsigned int)pc->b_count, (unsigned int)bcount);
 338                 drive->hwif->tp_ops->output_data(drive, NULL, pc->b_data, count);
 339                 bcount -= count;
 340                 pc->b_data += count;
 341                 pc->b_count -= count;
 342                 if (!pc->b_count) {
 343                         bh = bh->b_reqnext;
 344                         pc->bh = bh;
 345                         if (bh) {
 346                                 pc->b_data = bh->b_data;
 347                                 pc->b_count = atomic_read(&bh->b_count);
 348                         }
 349                 }
 350         }
 351
 352         return bcount;
 353 }
 354
 355 static void idetape_update_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc)
 356 {
 357         struct idetape_bh *bh = pc->bh;
 358         int count;
 359         unsigned int bcount = pc->xferred;
 360
 361         if (pc->flags & PC_FLAG_WRITING)
 362                 return;
 363         while (bcount) {
 364                 if (bh == NULL) {
 365                         printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
 366                                         __func__);
 367                         return;
 368                 }
 369                 count = min((unsigned int)bh->b_size, (unsigned int)bcount);
 370                 atomic_set(&bh->b_count, count);
 371                 if (atomic_read(&bh->b_count) == bh->b_size)
 372                         bh = bh->b_reqnext;
 373                 bcount -= count;
 374         }
 375         pc->bh = bh;
 376 }
 377
 378 /*
 379  * called on each failed packet command retry to analyze the request sense. We
 380  * currently do not utilize this information.
 381  */
 382 static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
 383 {
 384         idetape_tape_t *tape = drive->driver_data;
 385         struct ide_atapi_pc *pc = drive->failed_pc;
 386
 387         tape->sense_key = sense[2] & 0xF;
 388         tape->asc       = sense[12];
 389         tape->ascq      = sense[13];
 390
 391         debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
 392                  pc->c[0], tape->sense_key, tape->asc, tape->ascq);
 393
 394         /* Correct pc->xferred by asking the tape.       */
 395         if (pc->flags & PC_FLAG_DMA_ERROR) {
 396                 pc->xferred = pc->req_xfer -
 397                         tape->blk_size *
 398                         get_unaligned_be32(&sense[3]);
 399                 idetape_update_buffers(drive, pc);
 400         }
 401
 402         /*
 403          * If error was the result of a zero-length read or write command,
 404          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
 405          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
 406          */
 407         if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
 408             /* length == 0 */
 409             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
 410                 if (tape->sense_key == 5) {
 411                         /* don't report an error, everything's ok */
 412                         pc->error = 0;
 413                         /* don't retry read/write */
 414                         pc->flags |= PC_FLAG_ABORT;
 415                 }
 416         }
 417         if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
 418                 pc->error = IDE_DRV_ERROR_FILEMARK;
 419                 pc->flags |= PC_FLAG_ABORT;
 420         }
 421         if (pc->c[0] == WRITE_6) {
 422                 if ((sense[2] & 0x40) || (tape->sense_key == 0xd
 423                      && tape->asc == 0x0 && tape->ascq == 0x2)) {
 424                         pc->error = IDE_DRV_ERROR_EOD;
 425                         pc->flags |= PC_FLAG_ABORT;
 426                 }
 427         }
 428         if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 429                 if (tape->sense_key == 8) {
 430                         pc->error = IDE_DRV_ERROR_EOD;
 431                         pc->flags |= PC_FLAG_ABORT;
 432                 }
 433                 if (!(pc->flags & PC_FLAG_ABORT) &&
 434                     pc->xferred)
 435                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
 436         }
 437 }
 438
 439 /* Free data buffers completely. */
 440 static void ide_tape_kfree_buffer(idetape_tape_t *tape)
 441 {
 442         struct idetape_bh *prev_bh, *bh = tape->merge_bh;
 443
 444         while (bh) {
 445                 u32 size = bh->b_size;
 446
 447                 while (size) {
 448                         unsigned int order = fls(size >> PAGE_SHIFT)-1;
 449
 450                         if (bh->b_data)
 451                                 free_pages((unsigned long)bh->b_data, order);
 452
 453                         size &= (order-1);
 454                         bh->b_data += (1 << order) * PAGE_SIZE;
 455                 }
 456                 prev_bh = bh;
 457                 bh = bh->b_reqnext;
 458                 kfree(prev_bh);
 459         }
 460 }
 461
 462 static void ide_tape_handle_dsc(ide_drive_t *);
 463
 464 static int ide_tape_callback(ide_drive_t *drive, int dsc)
 465 {
 466         idetape_tape_t *tape = drive->driver_data;
 467         struct ide_atapi_pc *pc = drive->pc;
 468         struct request *rq = drive->hwif->rq;
 469         int uptodate = pc->error ? 0 : 1;
 470         int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 471
 472         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 473
 474         if (dsc)
 475                 ide_tape_handle_dsc(drive);
 476
 477         if (drive->failed_pc == pc)
 478                 drive->failed_pc = NULL;
 479
 480         if (pc->c[0] == REQUEST_SENSE) {
 481                 if (uptodate)
 482                         idetape_analyze_error(drive, pc->buf);
 483                 else
 484                         printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
 485                                         "itself - Aborting request!\n");
 486         } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 487                 int blocks = pc->xferred / tape->blk_size;
 488
 489                 tape->avg_size += blocks * tape->blk_size;
 490
 491                 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
 492                         tape->avg_speed = tape->avg_size * HZ /
 493                                 (jiffies - tape->avg_time) / 1024;
 494                         tape->avg_size = 0;
 495                         tape->avg_time = jiffies;
 496                 }
 497
 498                 tape->first_frame += blocks;
 499                 rq->current_nr_sectors -= blocks;
 500
 501                 if (pc->error) {
 502                         uptodate = 0;
 503                         err = pc->error;
 504                 }
 505         } else if (pc->c[0] == READ_POSITION && uptodate) {
 506                 u8 *readpos = pc->buf;
 507
 508                 debug_log(DBG_SENSE, "BOP - %s\n",
 509                                 (readpos[0] & 0x80) ? "Yes" : "No");
 510                 debug_log(DBG_SENSE, "EOP - %s\n",
 511                                 (readpos[0] & 0x40) ? "Yes" : "No");
 512
 513                 if (readpos[0] & 0x4) {
 514                         printk(KERN_INFO "ide-tape: Block location is unknown"
 515                                          "to the tape\n");
 516                         clear_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
 517                         uptodate = 0;
 518                         err = IDE_DRV_ERROR_GENERAL;
 519                 } else {
 520                         debug_log(DBG_SENSE, "Block Location - %u\n",
 521                                         be32_to_cpup((__be32 *)&readpos[4]));
 522
 523                         tape->partition = readpos[1];
 524                         tape->first_frame = be32_to_cpup((__be32 *)&readpos[4]);
 525                         set_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
 526                 }
 527         }
 528
 529         rq->errors = err;
 530
 531         return uptodate;
 532 }
 533
 534 /*
 535  * Postpone the current request so that ide.c will be able to service requests
 536  * from another device on the same port while we are polling for DSC.
 537  */
 538 static void idetape_postpone_request(ide_drive_t *drive)
 539 {
 540         idetape_tape_t *tape = drive->driver_data;
 541
 542         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 543
 544         tape->postponed_rq = drive->hwif->rq;
 545
 546         ide_stall_queue(drive, tape->dsc_poll_freq);
 547 }
 548
 549 static void ide_tape_handle_dsc(ide_drive_t *drive)
 550 {
 551         idetape_tape_t *tape = drive->driver_data;
 552
 553         /* Media access command */
 554         tape->dsc_polling_start = jiffies;
 555         tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
 556         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
 557         /* Allow ide.c to handle other requests */
 558         idetape_postpone_request(drive);
 559 }
 560
 561 static int ide_tape_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
 562                                 unsigned int bcount, int write)
 563 {
 564         unsigned int bleft;
 565
 566         if (write)
 567                 bleft = idetape_output_buffers(drive, pc, bcount);
 568         else
 569                 bleft = idetape_input_buffers(drive, pc, bcount);
 570
 571         return bcount - bleft;
 572 }
 573
 574 /*
 575  * Packet Command Interface
 576  *
 577  * The current Packet Command is available in drive->pc, and will not change
 578  * until we finish handling it. Each packet command is associated with a
 579  * callback function that will be called when the command is finished.
 580  *
 581  * The handling will be done in three stages:
 582  *
 583  * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
 584  * the interrupt handler to ide_pc_intr.
 585  *
 586  * 2. On each interrupt, ide_pc_intr will be called. This step will be
 587  * repeated until the device signals us that no more interrupts will be issued.
 588  *
 589  * 3. ATAPI Tape media access commands have immediate status with a delayed
 590  * process. In case of a successful initiation of a media access packet command,
 591  * the DSC bit will be set when the actual execution of the command is finished.
 592  * Since the tape drive will not issue an interrupt, we have to poll for this
 593  * event. In this case, we define the request as "low priority request" by
 594  * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 595  * exit the driver.
 596  *
 597  * ide.c will then give higher priority to requests which originate from the
 598  * other device, until will change rq_status to RQ_ACTIVE.
 599  *
 600  * 4. When the packet command is finished, it will be checked for errors.
 601  *
 602  * 5. In case an error was found, we queue a request sense packet command in
 603  * front of the request queue and retry the operation up to
 604  * IDETAPE_MAX_PC_RETRIES times.
 605  *
 606  * 6. In case no error was found, or we decided to give up and not to retry
 607  * again, the callback function will be called and then we will handle the next
 608  * request.
 609  */
 610
 611 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 612                                          struct ide_cmd *cmd,
 613                                          struct ide_atapi_pc *pc)
 614 {
 615         idetape_tape_t *tape = drive->driver_data;
 616
 617         if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
 618                 drive->failed_pc = pc;
 619
 620         /* Set the current packet command */
 621         drive->pc = pc;
 622
 623         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
 624                 (pc->flags & PC_FLAG_ABORT)) {
 625                 /*
 626                  * We will "abort" retrying a packet command in case legitimate
 627                  * error code was received (crossing a filemark, or end of the
 628                  * media, for example).
 629                  */
 630                 if (!(pc->flags & PC_FLAG_ABORT)) {
 631                         if (!(pc->c[0] == TEST_UNIT_READY &&
 632                               tape->sense_key == 2 && tape->asc == 4 &&
 633                              (tape->ascq == 1 || tape->ascq == 8))) {
 634                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
 635                                                 "pc = %2x, key = %2x, "
 636                                                 "asc = %2x, ascq = %2x\n",
 637                                                 tape->name, pc->c[0],
 638                                                 tape->sense_key, tape->asc,
 639                                                 tape->ascq);
 640                         }
 641                         /* Giving up */
 642                         pc->error = IDE_DRV_ERROR_GENERAL;
 643                 }
 644                 drive->failed_pc = NULL;
 645                 drive->pc_callback(drive, 0);
 646                 return ide_stopped;
 647         }
 648         debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
 649
 650         pc->retries++;
 651
 652         return ide_issue_pc(drive, cmd);
 653 }
 654
 655 /* A mode sense command is used to "sense" tape parameters. */
 656 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 657 {
 658         ide_init_pc(pc);
 659         pc->c[0] = MODE_SENSE;
 660         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
 661                 /* DBD = 1 - Don't return block descriptors */
 662                 pc->c[1] = 8;
 663         pc->c[2] = page_code;
 664         /*
 665          * Changed pc->c[3] to 0 (255 will at best return unused info).
 666          *
 667          * For SCSI this byte is defined as subpage instead of high byte
 668          * of length and some IDE drives seem to interpret it this way
 669          * and return an error when 255 is used.
 670          */
 671         pc->c[3] = 0;
 672         /* We will just discard data in that case */
 673         pc->c[4] = 255;
 674         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
 675                 pc->req_xfer = 12;
 676         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
 677                 pc->req_xfer = 24;
 678         else
 679                 pc->req_xfer = 50;
 680 }
 681
 682 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 683 {
 684         ide_hwif_t *hwif = drive->hwif;
 685         idetape_tape_t *tape = drive->driver_data;
 686         struct ide_atapi_pc *pc = drive->pc;
 687         u8 stat;
 688
 689         stat = hwif->tp_ops->read_status(hwif);
 690
 691         if (stat & ATA_DSC) {
 692                 if (stat & ATA_ERR) {
 693                         /* Error detected */
 694                         if (pc->c[0] != TEST_UNIT_READY)
 695                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
 696                                                 tape->name);
 697                         /* Retry operation */
 698                         ide_retry_pc(drive, tape->disk);
 699                         return ide_stopped;
 700                 }
 701                 pc->error = 0;
 702         } else {
 703                 pc->error = IDE_DRV_ERROR_GENERAL;
 704                 drive->failed_pc = NULL;
 705         }
 706         drive->pc_callback(drive, 0);
 707         return ide_stopped;
 708 }
 709
 710 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
 711                                    struct ide_atapi_pc *pc, struct request *rq,
 712                                    u8 opcode)
 713 {
 714         struct idetape_bh *bh = (struct idetape_bh *)rq->special;
 715         unsigned int length = rq->current_nr_sectors;
 716
 717         ide_init_pc(pc);
 718         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
 719         pc->c[1] = 1;
 720         pc->bh = bh;
 721         pc->buf = NULL;
 722         pc->buf_size = length * tape->blk_size;
 723         pc->req_xfer = pc->buf_size;
 724         if (pc->req_xfer == tape->buffer_size)
 725                 pc->flags |= PC_FLAG_DMA_OK;
 726
 727         if (opcode == READ_6) {
 728                 pc->c[0] = READ_6;
 729                 atomic_set(&bh->b_count, 0);
 730         } else if (opcode == WRITE_6) {
 731                 pc->c[0] = WRITE_6;
 732                 pc->flags |= PC_FLAG_WRITING;
 733                 pc->b_data = bh->b_data;
 734                 pc->b_count = atomic_read(&bh->b_count);
 735         }
 736
 737         memcpy(rq->cmd, pc->c, 12);
 738 }
 739
 740 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 741                                           struct request *rq, sector_t block)
 742 {
 743         ide_hwif_t *hwif = drive->hwif;
 744         idetape_tape_t *tape = drive->driver_data;
 745         struct ide_atapi_pc *pc = NULL;
 746         struct request *postponed_rq = tape->postponed_rq;
 747         struct ide_cmd cmd;
 748         u8 stat;
 749
 750         debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %lu,"
 751                         " current_nr_sectors: %u\n",
 752                         (unsigned long long)rq->sector, rq->nr_sectors,
 753                         rq->current_nr_sectors);
 754
 755         if (!blk_special_request(rq)) {
 756                 /* We do not support buffer cache originated requests. */
 757                 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
 758                         "request queue (%d)\n", drive->name, rq->cmd_type);
 759                 if (blk_fs_request(rq) == 0 && rq->errors == 0)
 760                         rq->errors = -EIO;
 761                 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
 762                 return ide_stopped;
 763         }
 764
 765         /* Retry a failed packet command */
 766         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 767                 pc = drive->failed_pc;
 768                 goto out;
 769         }
 770
 771         if (postponed_rq != NULL)
 772                 if (rq != postponed_rq) {
 773                         printk(KERN_ERR "ide-tape: ide-tape.c bug - "
 774                                         "Two DSC requests were queued\n");
 775                         drive->failed_pc = NULL;
 776                         rq->errors = 0;
 777                         ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 778                         return ide_stopped;
 779                 }
 780
 781         tape->postponed_rq = NULL;
 782
 783         /*
 784          * If the tape is still busy, postpone our request and service
 785          * the other device meanwhile.
 786          */
 787         stat = hwif->tp_ops->read_status(hwif);
 788
 789         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 790             (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
 791                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 792
 793         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 794                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 795                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 796         }
 797
 798         if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) &&
 799             (stat & ATA_DSC) == 0) {
 800                 if (postponed_rq == NULL) {
 801                         tape->dsc_polling_start = jiffies;
 802                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 803                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 804                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 805                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 806                                 tape->name);
 807                         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 808                                 idetape_media_access_finished(drive);
 809                                 return ide_stopped;
 810                         } else {
 811                                 return ide_do_reset(drive);
 812                         }
 813                 } else if (time_after(jiffies,
 814                                         tape->dsc_polling_start +
 815                                         IDETAPE_DSC_MA_THRESHOLD))
 816                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 817                 idetape_postpone_request(drive);
 818                 return ide_stopped;
 819         }
 820         if (rq->cmd[13] & REQ_IDETAPE_READ) {
 821                 pc = &tape->queued_pc;
 822                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 823                 goto out;
 824         }
 825         if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
 826                 pc = &tape->queued_pc;
 827                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 828                 goto out;
 829         }
 830         if (rq->cmd[13] & REQ_IDETAPE_PC1) {
 831                 pc = (struct ide_atapi_pc *) rq->buffer;
 832                 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
 833                 rq->cmd[13] |= REQ_IDETAPE_PC2;
 834                 goto out;
 835         }
 836         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 837                 idetape_media_access_finished(drive);
 838                 return ide_stopped;
 839         }
 840         BUG();
 841
 842 out:
 843         memset(&cmd, 0, sizeof(cmd));
 844
 845         if (rq_data_dir(rq))
 846                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 847
 848         cmd.rq = rq;
 849
 850         return ide_tape_issue_pc(drive, &cmd, pc);
 851 }
 852
 853 /*
 854  * The function below uses __get_free_pages to allocate a data buffer of size
 855  * tape->buffer_size (or a bit more). We attempt to combine sequential pages as
 856  * much as possible.
 857  *
 858  * It returns a pointer to the newly allocated buffer, or NULL in case of
 859  * failure.
 860  */
 861 static struct idetape_bh *ide_tape_kmalloc_buffer(idetape_tape_t *tape,
 862                                                   int full, int clear)
 863 {
 864         struct idetape_bh *prev_bh, *bh, *merge_bh;
 865         int pages = tape->pages_per_buffer;
 866         unsigned int order, b_allocd;
 867         char *b_data = NULL;
 868
 869         merge_bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
 870         bh = merge_bh;
 871         if (bh == NULL)
 872                 goto abort;
 873
 874         order = fls(pages) - 1;
 875         bh->b_data = (char *) __get_free_pages(GFP_KERNEL, order);
 876         if (!bh->b_data)
 877                 goto abort;
 878         b_allocd = (1 << order) * PAGE_SIZE;
 879         pages &= (order-1);
 880
 881         if (clear)
 882                 memset(bh->b_data, 0, b_allocd);
 883         bh->b_reqnext = NULL;
 884         bh->b_size = b_allocd;
 885         atomic_set(&bh->b_count, full ? bh->b_size : 0);
 886
 887         while (pages) {
 888                 order = fls(pages) - 1;
 889                 b_data = (char *) __get_free_pages(GFP_KERNEL, order);
 890                 if (!b_data)
 891                         goto abort;
 892                 b_allocd = (1 << order) * PAGE_SIZE;
 893
 894                 if (clear)
 895                         memset(b_data, 0, b_allocd);
 896
 897                 /* newly allocated page frames below buffer header or ...*/
 898                 if (bh->b_data == b_data + b_allocd) {
 899                         bh->b_size += b_allocd;
 900                         bh->b_data -= b_allocd;
 901                         if (full)
 902                                 atomic_add(b_allocd, &bh->b_count);
 903                         continue;
 904                 }
 905                 /* they are above the header */
 906                 if (b_data == bh->b_data + bh->b_size) {
 907                         bh->b_size += b_allocd;
 908                         if (full)
 909                                 atomic_add(b_allocd, &bh->b_count);
 910                         continue;
 911                 }
 912                 prev_bh = bh;
 913                 bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
 914                 if (!bh) {
 915                         free_pages((unsigned long) b_data, order);
 916                         goto abort;
 917                 }
 918                 bh->b_reqnext = NULL;
 919                 bh->b_data = b_data;
 920                 bh->b_size = b_allocd;
 921                 atomic_set(&bh->b_count, full ? bh->b_size : 0);
 922                 prev_bh->b_reqnext = bh;
 923
 924                 pages &= (order-1);
 925         }
 926
 927         bh->b_size -= tape->excess_bh_size;
 928         if (full)
 929                 atomic_sub(tape->excess_bh_size, &bh->b_count);
 930         return merge_bh;
 931 abort:
 932         ide_tape_kfree_buffer(tape);
 933         return NULL;
 934 }
 935
 936 static int idetape_copy_stage_from_user(idetape_tape_t *tape,
 937                                         const char __user *buf, int n)
 938 {
 939         struct idetape_bh *bh = tape->bh;
 940         int count;
 941         int ret = 0;
 942
 943         while (n) {
 944                 if (bh == NULL) {
 945                         printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
 946                                         __func__);
 947                         return 1;
 948                 }
 949                 count = min((unsigned int)
 950                                 (bh->b_size - atomic_read(&bh->b_count)),
 951                                 (unsigned int)n);
 952                 if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf,
 953                                 count))
 954                         ret = 1;
 955                 n -= count;
 956                 atomic_add(count, &bh->b_count);
 957                 buf += count;
 958                 if (atomic_read(&bh->b_count) == bh->b_size) {
 959                         bh = bh->b_reqnext;
 960                         if (bh)
 961                                 atomic_set(&bh->b_count, 0);
 962                 }
 963         }
 964         tape->bh = bh;
 965         return ret;
 966 }
 967
 968 static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf,
 969                                       int n)
 970 {
 971         struct idetape_bh *bh = tape->bh;
 972         int count;
 973         int ret = 0;
 974
 975         while (n) {
 976                 if (bh == NULL) {
 977                         printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
 978                                         __func__);
 979                         return 1;
 980                 }
 981                 count = min(tape->b_count, n);
 982                 if  (copy_to_user(buf, tape->b_data, count))
 983                         ret = 1;
 984                 n -= count;
 985                 tape->b_data += count;
 986                 tape->b_count -= count;
 987                 buf += count;
 988                 if (!tape->b_count) {
 989                         bh = bh->b_reqnext;
 990                         tape->bh = bh;
 991                         if (bh) {
 992                                 tape->b_data = bh->b_data;
 993                                 tape->b_count = atomic_read(&bh->b_count);
 994                         }
 995                 }
 996         }
 997         return ret;
 998 }
 999
1000 static void idetape_init_merge_buffer(idetape_tape_t *tape)
1001 {
1002         struct idetape_bh *bh = tape->merge_bh;
1003         tape->bh = tape->merge_bh;
1004
1005         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1006                 atomic_set(&bh->b_count, 0);
1007         else {
1008                 tape->b_data = bh->b_data;
1009                 tape->b_count = atomic_read(&bh->b_count);
1010         }
1011 }
1012
1013 /*
1014  * Write a filemark if write_filemark=1. Flush the device buffers without
1015  * writing a filemark otherwise.
1016  */
1017 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
1018                 struct ide_atapi_pc *pc, int write_filemark)
1019 {
1020         ide_init_pc(pc);
1021         pc->c[0] = WRITE_FILEMARKS;
1022         pc->c[4] = write_filemark;
1023         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1024 }
1025
1026 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
1027 {
1028         idetape_tape_t *tape = drive->driver_data;
1029         struct gendisk *disk = tape->disk;
1030         int load_attempted = 0;
1031
1032         /* Wait for the tape to become ready */
1033         set_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1034         timeout += jiffies;
1035         while (time_before(jiffies, timeout)) {
1036                 if (ide_do_test_unit_ready(drive, disk) == 0)
1037                         return 0;
1038                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
1039                     || (tape->asc == 0x3A)) {
1040                         /* no media */
1041                         if (load_attempted)
1042                                 return -ENOMEDIUM;
1043                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1044                         load_attempted = 1;
1045                 /* not about to be ready */
1046                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
1047                              (tape->ascq == 1 || tape->ascq == 8)))
1048                         return -EIO;
1049                 msleep(100);
1050         }
1051         return -EIO;
1052 }
1053
1054 static int idetape_flush_tape_buffers(ide_drive_t *drive)
1055 {
1056         struct ide_tape_obj *tape = drive->driver_data;
1057         struct ide_atapi_pc pc;
1058         int rc;
1059
1060         idetape_create_write_filemark_cmd(drive, &pc, 0);
1061         rc = ide_queue_pc_tail(drive, tape->disk, &pc);
1062         if (rc)
1063                 return rc;
1064         idetape_wait_ready(drive, 60 * 5 * HZ);
1065         return 0;
1066 }
1067
1068 static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc)
1069 {
1070         ide_init_pc(pc);
1071         pc->c[0] = READ_POSITION;
1072         pc->req_xfer = 20;
1073 }
1074
1075 static int idetape_read_position(ide_drive_t *drive)
1076 {
1077         idetape_tape_t *tape = drive->driver_data;
1078         struct ide_atapi_pc pc;
1079         int position;
1080
1081         debug_log(DBG_PROCS, "Enter %s\n", __func__);
1082
1083         idetape_create_read_position_cmd(&pc);
1084         if (ide_queue_pc_tail(drive, tape->disk, &pc))
1085                 return -1;
1086         position = tape->first_frame;
1087         return position;
1088 }
1089
1090 static void idetape_create_locate_cmd(ide_drive_t *drive,
1091                 struct ide_atapi_pc *pc,
1092                 unsigned int block, u8 partition, int skip)
1093 {
1094         ide_init_pc(pc);
1095         pc->c[0] = POSITION_TO_ELEMENT;
1096         pc->c[1] = 2;
1097         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
1098         pc->c[8] = partition;
1099         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1100 }
1101
1102 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
1103 {
1104         idetape_tape_t *tape = drive->driver_data;
1105
1106         if (tape->chrdev_dir != IDETAPE_DIR_READ)
1107                 return;
1108
1109         clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags);
1110         tape->merge_bh_size = 0;
1111         if (tape->merge_bh != NULL) {
1112                 ide_tape_kfree_buffer(tape);
1113                 tape->merge_bh = NULL;
1114         }
1115
1116         tape->chrdev_dir = IDETAPE_DIR_NONE;
1117 }
1118
1119 /*
1120  * Position the tape to the requested block using the LOCATE packet command.
1121  * A READ POSITION command is then issued to check where we are positioned. Like
1122  * all higher level operations, we queue the commands at the tail of the request
1123  * queue and wait for their completion.
1124  */
1125 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
1126                 u8 partition, int skip)
1127 {
1128         idetape_tape_t *tape = drive->driver_data;
1129         struct gendisk *disk = tape->disk;
1130         int retval;
1131         struct ide_atapi_pc pc;
1132
1133         if (tape->chrdev_dir == IDETAPE_DIR_READ)
1134                 __ide_tape_discard_merge_buffer(drive);
1135         idetape_wait_ready(drive, 60 * 5 * HZ);
1136         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
1137         retval = ide_queue_pc_tail(drive, disk, &pc);
1138         if (retval)
1139                 return (retval);
1140
1141         idetape_create_read_position_cmd(&pc);
1142         return ide_queue_pc_tail(drive, disk, &pc);
1143 }
1144
1145 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
1146                                           int restore_position)
1147 {
1148         idetape_tape_t *tape = drive->driver_data;
1149         int seek, position;
1150
1151         __ide_tape_discard_merge_buffer(drive);
1152         if (restore_position) {
1153                 position = idetape_read_position(drive);
1154                 seek = position > 0 ? position : 0;
1155                 if (idetape_position_tape(drive, seek, 0, 0)) {
1156                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
1157                                          " %s\n", tape->name, __func__);
1158                         return;
1159                 }
1160         }
1161 }
1162
1163 /*
1164  * Generate a read/write request for the block device interface and wait for it
1165  * to be serviced.
1166  */
1167 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks,
1168                                  struct idetape_bh *bh)
1169 {
1170         idetape_tape_t *tape = drive->driver_data;
1171         struct request *rq;
1172         int ret, errors;
1173
1174         debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
1175
1176         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
1177         rq->cmd_type = REQ_TYPE_SPECIAL;
1178         rq->cmd[13] = cmd;
1179         rq->rq_disk = tape->disk;
1180         rq->special = (void *)bh;
1181         rq->sector = tape->first_frame;
1182         rq->nr_sectors = blocks;
1183         rq->current_nr_sectors = blocks;
1184         blk_execute_rq(drive->queue, tape->disk, rq, 0);
1185
1186         errors = rq->errors;
1187         ret = tape->blk_size * (blocks - rq->current_nr_sectors);
1188         blk_put_request(rq);
1189
1190         if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
1191                 return 0;
1192
1193         if (tape->merge_bh)
1194                 idetape_init_merge_buffer(tape);
1195         if (errors == IDE_DRV_ERROR_GENERAL)
1196                 return -EIO;
1197         return ret;
1198 }
1199
1200 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
1201 {
1202         ide_init_pc(pc);
1203         pc->c[0] = INQUIRY;
1204         pc->c[4] = 254;
1205         pc->req_xfer = 254;
1206 }
1207
1208 static void idetape_create_rewind_cmd(ide_drive_t *drive,
1209                 struct ide_atapi_pc *pc)
1210 {
1211         ide_init_pc(pc);
1212         pc->c[0] = REZERO_UNIT;
1213         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1214 }
1215
1216 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
1217 {
1218         ide_init_pc(pc);
1219         pc->c[0] = ERASE;
1220         pc->c[1] = 1;
1221         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1222 }
1223
1224 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
1225 {
1226         ide_init_pc(pc);
1227         pc->c[0] = SPACE;
1228         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
1229         pc->c[1] = cmd;
1230         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1231 }
1232
1233 /* Queue up a character device originated write request. */
1234 static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks)
1235 {
1236         idetape_tape_t *tape = drive->driver_data;
1237
1238         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1239
1240         return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1241                                      blocks, tape->merge_bh);
1242 }
1243
1244 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
1245 {
1246         idetape_tape_t *tape = drive->driver_data;
1247         int blocks, min;
1248         struct idetape_bh *bh;
1249
1250         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
1251                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
1252                                 " but we are not writing.\n");
1253                 return;
1254         }
1255         if (tape->merge_bh_size > tape->buffer_size) {
1256                 printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
1257                 tape->merge_bh_size = tape->buffer_size;
1258         }
1259         if (tape->merge_bh_size) {
1260                 blocks = tape->merge_bh_size / tape->blk_size;
1261                 if (tape->merge_bh_size % tape->blk_size) {
1262                         unsigned int i;
1263
1264                         blocks++;
1265                         i = tape->blk_size - tape->merge_bh_size %
1266                                 tape->blk_size;
1267                         bh = tape->bh->b_reqnext;
1268                         while (bh) {
1269                                 atomic_set(&bh->b_count, 0);
1270                                 bh = bh->b_reqnext;
1271                         }
1272                         bh = tape->bh;
1273                         while (i) {
1274                                 if (bh == NULL) {
1275                                         printk(KERN_INFO "ide-tape: bug,"
1276                                                          " bh NULL\n");
1277                                         break;
1278                                 }
1279                                 min = min(i, (unsigned int)(bh->b_size -
1280                                                 atomic_read(&bh->b_count)));
1281                                 memset(bh->b_data + atomic_read(&bh->b_count),
1282                                                 0, min);
1283                                 atomic_add(min, &bh->b_count);
1284                                 i -= min;
1285                                 bh = bh->b_reqnext;
1286                         }
1287                 }
1288                 (void) idetape_add_chrdev_write_request(drive, blocks);
1289                 tape->merge_bh_size = 0;
1290         }
1291         if (tape->merge_bh != NULL) {
1292                 ide_tape_kfree_buffer(tape);
1293                 tape->merge_bh = NULL;
1294         }
1295         tape->chrdev_dir = IDETAPE_DIR_NONE;
1296 }
1297
1298 static int idetape_init_read(ide_drive_t *drive)
1299 {
1300         idetape_tape_t *tape = drive->driver_data;
1301         int bytes_read;
1302
1303         /* Initialize read operation */
1304         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1305                 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1306                         ide_tape_flush_merge_buffer(drive);
1307                         idetape_flush_tape_buffers(drive);
1308                 }
1309                 if (tape->merge_bh || tape->merge_bh_size) {
1310                         printk(KERN_ERR "ide-tape: merge_bh_size should be"
1311                                          " 0 now\n");
1312                         tape->merge_bh_size = 0;
1313                 }
1314                 tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
1315                 if (!tape->merge_bh)
1316                         return -ENOMEM;
1317                 tape->chrdev_dir = IDETAPE_DIR_READ;
1318
1319                 /*
1320                  * Issue a read 0 command to ensure that DSC handshake is
1321                  * switched from completion mode to buffer available mode.
1322                  * No point in issuing this if DSC overlap isn't supported, some
1323                  * drives (Seagate STT3401A) will return an error.
1324                  */
1325                 if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1326                         bytes_read = idetape_queue_rw_tail(drive,
1327                                                         REQ_IDETAPE_READ, 0,
1328                                                         tape->merge_bh);
1329                         if (bytes_read < 0) {
1330                                 ide_tape_kfree_buffer(tape);
1331                                 tape->merge_bh = NULL;
1332                                 tape->chrdev_dir = IDETAPE_DIR_NONE;
1333                                 return bytes_read;
1334                         }
1335                 }
1336         }
1337
1338         return 0;
1339 }
1340
1341 /* called from idetape_chrdev_read() to service a chrdev read request. */
1342 static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
1343 {
1344         idetape_tape_t *tape = drive->driver_data;
1345
1346         debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks);
1347
1348         /* If we are at a filemark, return a read length of 0 */
1349         if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1350                 return 0;
1351
1352         idetape_init_read(drive);
1353
1354         return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
1355                                      tape->merge_bh);
1356 }
1357
1358 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
1359 {
1360         idetape_tape_t *tape = drive->driver_data;
1361         struct idetape_bh *bh;
1362         int blocks;
1363
1364         while (bcount) {
1365                 unsigned int count;
1366
1367                 bh = tape->merge_bh;
1368                 count = min(tape->buffer_size, bcount);
1369                 bcount -= count;
1370                 blocks = count / tape->blk_size;
1371                 while (count) {
1372                         atomic_set(&bh->b_count,
1373                                    min(count, (unsigned int)bh->b_size));
1374                         memset(bh->b_data, 0, atomic_read(&bh->b_count));
1375                         count -= atomic_read(&bh->b_count);
1376                         bh = bh->b_reqnext;
1377                 }
1378                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks,
1379                                       tape->merge_bh);
1380         }
1381 }
1382
1383 /*
1384  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1385  * currently support only one partition.
1386  */
1387 static int idetape_rewind_tape(ide_drive_t *drive)
1388 {
1389         struct ide_tape_obj *tape = drive->driver_data;
1390         struct gendisk *disk = tape->disk;
1391         int retval;
1392         struct ide_atapi_pc pc;
1393
1394         debug_log(DBG_SENSE, "Enter %s\n", __func__);
1395
1396         idetape_create_rewind_cmd(drive, &pc);
1397         retval = ide_queue_pc_tail(drive, disk, &pc);
1398         if (retval)
1399                 return retval;
1400
1401         idetape_create_read_position_cmd(&pc);
1402         retval = ide_queue_pc_tail(drive, disk, &pc);
1403         if (retval)
1404                 return retval;
1405         return 0;
1406 }
1407
1408 /* mtio.h compatible commands should be issued to the chrdev interface. */
1409 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1410                                 unsigned long arg)
1411 {
1412         idetape_tape_t *tape = drive->driver_data;
1413         void __user *argp = (void __user *)arg;
1414
1415         struct idetape_config {
1416                 int dsc_rw_frequency;
1417                 int dsc_media_access_frequency;
1418                 int nr_stages;
1419         } config;
1420
1421         debug_log(DBG_PROCS, "Enter %s\n", __func__);
1422
1423         switch (cmd) {
1424         case 0x0340:
1425                 if (copy_from_user(&config, argp, sizeof(config)))
1426                         return -EFAULT;
1427                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1428                 break;
1429         case 0x0350:
1430                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1431                 config.nr_stages = 1;
1432                 if (copy_to_user(argp, &config, sizeof(config)))
1433                         return -EFAULT;
1434                 break;
1435         default:
1436                 return -EIO;
1437         }
1438         return 0;
1439 }
1440
1441 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1442                                         int mt_count)
1443 {
1444         idetape_tape_t *tape = drive->driver_data;
1445         struct gendisk *disk = tape->disk;
1446         struct ide_atapi_pc pc;
1447         int retval, count = 0;
1448         int sprev = !!(tape->caps[4] & 0x20);
1449
1450         if (mt_count == 0)
1451                 return 0;
1452         if (MTBSF == mt_op || MTBSFM == mt_op) {
1453                 if (!sprev)
1454                         return -EIO;
1455                 mt_count = -mt_count;
1456         }
1457
1458         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1459                 tape->merge_bh_size = 0;
1460                 if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1461                         ++count;
1462                 ide_tape_discard_merge_buffer(drive, 0);
1463         }
1464
1465         switch (mt_op) {
1466         case MTFSF:
1467         case MTBSF:
1468                 idetape_create_space_cmd(&pc, mt_count - count,
1469                                          IDETAPE_SPACE_OVER_FILEMARK);
1470                 return ide_queue_pc_tail(drive, disk, &pc);
1471         case MTFSFM:
1472         case MTBSFM:
1473                 if (!sprev)
1474                         return -EIO;
1475                 retval = idetape_space_over_filemarks(drive, MTFSF,
1476                                                       mt_count - count);
1477                 if (retval)
1478                         return retval;
1479                 count = (MTBSFM == mt_op ? 1 : -1);
1480                 return idetape_space_over_filemarks(drive, MTFSF, count);
1481         default:
1482                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1483                                 mt_op);
1484                 return -EIO;
1485         }
1486 }
1487
1488 /*
1489  * Our character device read / write functions.
1490  *
1491  * The tape is optimized to maximize throughput when it is transferring an
1492  * integral number of the "continuous transfer limit", which is a parameter of
1493  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1494  *
1495  * As of version 1.3 of the driver, the character device provides an abstract
1496  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1497  * same backup/restore procedure is supported. The driver will internally
1498  * convert the requests to the recommended transfer unit, so that an unmatch
1499  * between the user's block size to the recommended size will only result in a
1500  * (slightly) increased driver overhead, but will no longer hit performance.
1501  * This is not applicable to Onstream.
1502  */
1503 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1504                                    size_t count, loff_t *ppos)
1505 {
1506         struct ide_tape_obj *tape = file->private_data;
1507         ide_drive_t *drive = tape->drive;
1508         ssize_t bytes_read, temp, actually_read = 0, rc;
1509         ssize_t ret = 0;
1510         u16 ctl = *(u16 *)&tape->caps[12];
1511
1512         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1513
1514         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1515                 if (test_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags))
1516                         if (count > tape->blk_size &&
1517                             (count % tape->blk_size) == 0)
1518                                 tape->user_bs_factor = count / tape->blk_size;
1519         }
1520         rc = idetape_init_read(drive);
1521         if (rc < 0)
1522                 return rc;
1523         if (count == 0)
1524                 return (0);
1525         if (tape->merge_bh_size) {
1526                 actually_read = min((unsigned int)(tape->merge_bh_size),
1527                                     (unsigned int)count);
1528                 if (idetape_copy_stage_to_user(tape, buf, actually_read))
1529                         ret = -EFAULT;
1530                 buf += actually_read;
1531                 tape->merge_bh_size -= actually_read;
1532                 count -= actually_read;
1533         }
1534         while (count >= tape->buffer_size) {
1535                 bytes_read = idetape_add_chrdev_read_request(drive, ctl);
1536                 if (bytes_read <= 0)
1537                         goto finish;
1538                 if (idetape_copy_stage_to_user(tape, buf, bytes_read))
1539                         ret = -EFAULT;
1540                 buf += bytes_read;
1541                 count -= bytes_read;
1542                 actually_read += bytes_read;
1543         }
1544         if (count) {
1545                 bytes_read = idetape_add_chrdev_read_request(drive, ctl);
1546                 if (bytes_read <= 0)
1547                         goto finish;
1548                 temp = min((unsigned long)count, (unsigned long)bytes_read);
1549                 if (idetape_copy_stage_to_user(tape, buf, temp))
1550                         ret = -EFAULT;
1551                 actually_read += temp;
1552                 tape->merge_bh_size = bytes_read-temp;
1553         }
1554 finish:
1555         if (!actually_read && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) {
1556                 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
1557
1558                 idetape_space_over_filemarks(drive, MTFSF, 1);
1559                 return 0;
1560         }
1561
1562         return ret ? ret : actually_read;
1563 }
1564
1565 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1566                                      size_t count, loff_t *ppos)
1567 {
1568         struct ide_tape_obj *tape = file->private_data;
1569         ide_drive_t *drive = tape->drive;
1570         ssize_t actually_written = 0;
1571         ssize_t ret = 0;
1572         u16 ctl = *(u16 *)&tape->caps[12];
1573
1574         /* The drive is write protected. */
1575         if (tape->write_prot)
1576                 return -EACCES;
1577
1578         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1579
1580         /* Initialize write operation */
1581         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
1582                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1583                         ide_tape_discard_merge_buffer(drive, 1);
1584                 if (tape->merge_bh || tape->merge_bh_size) {
1585                         printk(KERN_ERR "ide-tape: merge_bh_size "
1586                                 "should be 0 now\n");
1587                         tape->merge_bh_size = 0;
1588                 }
1589                 tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
1590                 if (!tape->merge_bh)
1591                         return -ENOMEM;
1592                 tape->chrdev_dir = IDETAPE_DIR_WRITE;
1593                 idetape_init_merge_buffer(tape);
1594
1595                 /*
1596                  * Issue a write 0 command to ensure that DSC handshake is
1597                  * switched from completion mode to buffer available mode. No
1598                  * point in issuing this if DSC overlap isn't supported, some
1599                  * drives (Seagate STT3401A) will return an error.
1600                  */
1601                 if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1602                         ssize_t retval = idetape_queue_rw_tail(drive,
1603                                                         REQ_IDETAPE_WRITE, 0,
1604                                                         tape->merge_bh);
1605                         if (retval < 0) {
1606                                 ide_tape_kfree_buffer(tape);
1607                                 tape->merge_bh = NULL;
1608                                 tape->chrdev_dir = IDETAPE_DIR_NONE;
1609                                 return retval;
1610                         }
1611                 }
1612         }
1613         if (count == 0)
1614                 return (0);
1615         if (tape->merge_bh_size) {
1616                 if (tape->merge_bh_size >= tape->buffer_size) {
1617                         printk(KERN_ERR "ide-tape: bug: merge buf too big\n");
1618                         tape->merge_bh_size = 0;
1619                 }
1620                 actually_written = min((unsigned int)
1621                                 (tape->buffer_size - tape->merge_bh_size),
1622                                 (unsigned int)count);
1623                 if (idetape_copy_stage_from_user(tape, buf, actually_written))
1624                                 ret = -EFAULT;
1625                 buf += actually_written;
1626                 tape->merge_bh_size += actually_written;
1627                 count -= actually_written;
1628
1629                 if (tape->merge_bh_size == tape->buffer_size) {
1630                         ssize_t retval;
1631                         tape->merge_bh_size = 0;
1632                         retval = idetape_add_chrdev_write_request(drive, ctl);
1633                         if (retval <= 0)
1634                                 return (retval);
1635                 }
1636         }
1637         while (count >= tape->buffer_size) {
1638                 ssize_t retval;
1639                 if (idetape_copy_stage_from_user(tape, buf, tape->buffer_size))
1640                         ret = -EFAULT;
1641                 buf += tape->buffer_size;
1642                 count -= tape->buffer_size;
1643                 retval = idetape_add_chrdev_write_request(drive, ctl);
1644                 actually_written += tape->buffer_size;
1645                 if (retval <= 0)
1646                         return (retval);
1647         }
1648         if (count) {
1649                 actually_written += count;
1650                 if (idetape_copy_stage_from_user(tape, buf, count))
1651                         ret = -EFAULT;
1652                 tape->merge_bh_size += count;
1653         }
1654         return ret ? ret : actually_written;
1655 }
1656
1657 static int idetape_write_filemark(ide_drive_t *drive)
1658 {
1659         struct ide_tape_obj *tape = drive->driver_data;
1660         struct ide_atapi_pc pc;
1661
1662         /* Write a filemark */
1663         idetape_create_write_filemark_cmd(drive, &pc, 1);
1664         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1665                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1666                 return -EIO;
1667         }
1668         return 0;
1669 }
1670
1671 /*
1672  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1673  * requested.
1674  *
1675  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1676  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1677  * usually not supported.
1678  *
1679  * The following commands are currently not supported:
1680  *
1681  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1682  * MT_ST_WRITE_THRESHOLD.
1683  */
1684 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1685 {
1686         idetape_tape_t *tape = drive->driver_data;
1687         struct gendisk *disk = tape->disk;
1688         struct ide_atapi_pc pc;
1689         int i, retval;
1690
1691         debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
1692                         mt_op, mt_count);
1693
1694         switch (mt_op) {
1695         case MTFSF:
1696         case MTFSFM:
1697         case MTBSF:
1698         case MTBSFM:
1699                 if (!mt_count)
1700                         return 0;
1701                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1702         default:
1703                 break;
1704         }
1705
1706         switch (mt_op) {
1707         case MTWEOF:
1708                 if (tape->write_prot)
1709                         return -EACCES;
1710                 ide_tape_discard_merge_buffer(drive, 1);
1711                 for (i = 0; i < mt_count; i++) {
1712                         retval = idetape_write_filemark(drive);
1713                         if (retval)
1714                                 return retval;
1715                 }
1716                 return 0;
1717         case MTREW:
1718                 ide_tape_discard_merge_buffer(drive, 0);
1719                 if (idetape_rewind_tape(drive))
1720                         return -EIO;
1721                 return 0;
1722         case MTLOAD:
1723                 ide_tape_discard_merge_buffer(drive, 0);
1724                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1725         case MTUNLOAD:
1726         case MTOFFL:
1727                 /*
1728                  * If door is locked, attempt to unlock before
1729                  * attempting to eject.
1730                  */
1731                 if (tape->door_locked) {
1732                         if (!ide_set_media_lock(drive, disk, 0))
1733                                 tape->door_locked = DOOR_UNLOCKED;
1734                 }
1735                 ide_tape_discard_merge_buffer(drive, 0);
1736                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1737                 if (!retval)
1738                         clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1739                 return retval;
1740         case MTNOP:
1741                 ide_tape_discard_merge_buffer(drive, 0);
1742                 return idetape_flush_tape_buffers(drive);
1743         case MTRETEN:
1744                 ide_tape_discard_merge_buffer(drive, 0);
1745                 return ide_do_start_stop(drive, disk,
1746                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1747         case MTEOM:
1748                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1749                 return ide_queue_pc_tail(drive, disk, &pc);
1750         case MTERASE:
1751                 (void)idetape_rewind_tape(drive);
1752                 idetape_create_erase_cmd(&pc);
1753                 return ide_queue_pc_tail(drive, disk, &pc);
1754         case MTSETBLK:
1755                 if (mt_count) {
1756                         if (mt_count < tape->blk_size ||
1757                             mt_count % tape->blk_size)
1758                                 return -EIO;
1759                         tape->user_bs_factor = mt_count / tape->blk_size;
1760                         clear_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1761                 } else
1762                         set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1763                 return 0;
1764         case MTSEEK:
1765                 ide_tape_discard_merge_buffer(drive, 0);
1766                 return idetape_position_tape(drive,
1767                         mt_count * tape->user_bs_factor, tape->partition, 0);
1768         case MTSETPART:
1769                 ide_tape_discard_merge_buffer(drive, 0);
1770                 return idetape_position_tape(drive, 0, mt_count, 0);
1771         case MTFSR:
1772         case MTBSR:
1773         case MTLOCK:
1774                 retval = ide_set_media_lock(drive, disk, 1);
1775                 if (retval)
1776                         return retval;
1777                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1778                 return 0;
1779         case MTUNLOCK:
1780                 retval = ide_set_media_lock(drive, disk, 0);
1781                 if (retval)
1782                         return retval;
1783                 tape->door_locked = DOOR_UNLOCKED;
1784                 return 0;
1785         default:
1786                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1787                                 mt_op);
1788                 return -EIO;
1789         }
1790 }
1791
1792 /*
1793  * Our character device ioctls. General mtio.h magnetic io commands are
1794  * supported here, and not in the corresponding block interface. Our own
1795  * ide-tape ioctls are supported on both interfaces.
1796  */
1797 static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
1798                                 unsigned int cmd, unsigned long arg)
1799 {
1800         struct ide_tape_obj *tape = file->private_data;
1801         ide_drive_t *drive = tape->drive;
1802         struct mtop mtop;
1803         struct mtget mtget;
1804         struct mtpos mtpos;
1805         int block_offset = 0, position = tape->first_frame;
1806         void __user *argp = (void __user *)arg;
1807
1808         debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
1809
1810         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1811                 ide_tape_flush_merge_buffer(drive);
1812                 idetape_flush_tape_buffers(drive);
1813         }
1814         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1815                 block_offset = tape->merge_bh_size /
1816                         (tape->blk_size * tape->user_bs_factor);
1817                 position = idetape_read_position(drive);
1818                 if (position < 0)
1819                         return -EIO;
1820         }
1821         switch (cmd) {
1822         case MTIOCTOP:
1823                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1824                         return -EFAULT;
1825                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1826         case MTIOCGET:
1827                 memset(&mtget, 0, sizeof(struct mtget));
1828                 mtget.mt_type = MT_ISSCSI2;
1829                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1830                 mtget.mt_dsreg =
1831                         ((tape->blk_size * tape->user_bs_factor)
1832                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1833
1834                 if (tape->drv_write_prot)
1835                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1836
1837                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1838                         return -EFAULT;
1839                 return 0;
1840         case MTIOCPOS:
1841                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1842                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1843                         return -EFAULT;
1844                 return 0;
1845         default:
1846                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1847                         ide_tape_discard_merge_buffer(drive, 1);
1848                 return idetape_blkdev_ioctl(drive, cmd, arg);
1849         }
1850 }
1851
1852 /*
1853  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1854  * block size with the reported value.
1855  */
1856 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1857 {
1858         idetape_tape_t *tape = drive->driver_data;
1859         struct ide_atapi_pc pc;
1860
1861         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1862         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1863                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1864                 if (tape->blk_size == 0) {
1865                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1866                                             "block size, assuming 32k\n");
1867                         tape->blk_size = 32768;
1868                 }
1869                 return;
1870         }
1871         tape->blk_size = (pc.buf[4 + 5] << 16) +
1872                                 (pc.buf[4 + 6] << 8)  +
1873                                  pc.buf[4 + 7];
1874         tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7;
1875 }
1876
1877 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1878 {
1879         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1880         ide_drive_t *drive;
1881         idetape_tape_t *tape;
1882         int retval;
1883
1884         if (i >= MAX_HWIFS * MAX_DRIVES)
1885                 return -ENXIO;
1886
1887         lock_kernel();
1888         tape = ide_tape_chrdev_get(i);
1889         if (!tape) {
1890                 unlock_kernel();
1891                 return -ENXIO;
1892         }
1893
1894         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1895
1896         /*
1897          * We really want to do nonseekable_open(inode, filp); here, but some
1898          * versions of tar incorrectly call lseek on tapes and bail out if that
1899          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1900          */
1901         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1902
1903         drive = tape->drive;
1904
1905         filp->private_data = tape;
1906
1907         if (test_and_set_bit(IDE_AFLAG_BUSY, &drive->atapi_flags)) {
1908                 retval = -EBUSY;
1909                 goto out_put_tape;
1910         }
1911
1912         retval = idetape_wait_ready(drive, 60 * HZ);
1913         if (retval) {
1914                 clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1915                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1916                 goto out_put_tape;
1917         }
1918
1919         idetape_read_position(drive);
1920         if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags))
1921                 (void)idetape_rewind_tape(drive);
1922
1923         /* Read block size and write protect status from drive. */
1924         ide_tape_get_bsize_from_bdesc(drive);
1925
1926         /* Set write protect flag if device is opened as read-only. */
1927         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1928                 tape->write_prot = 1;
1929         else
1930                 tape->write_prot = tape->drv_write_prot;
1931
1932         /* Make sure drive isn't write protected if user wants to write. */
1933         if (tape->write_prot) {
1934                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1935                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1936                         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1937                         retval = -EROFS;
1938                         goto out_put_tape;
1939                 }
1940         }
1941
1942         /* Lock the tape drive door so user can't eject. */
1943         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1944                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1945                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1946                                 tape->door_locked = DOOR_LOCKED;
1947                 }
1948         }
1949         unlock_kernel();
1950         return 0;
1951
1952 out_put_tape:
1953         ide_tape_put(tape);
1954         unlock_kernel();
1955         return retval;
1956 }
1957
1958 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1959 {
1960         idetape_tape_t *tape = drive->driver_data;
1961
1962         ide_tape_flush_merge_buffer(drive);
1963         tape->merge_bh = ide_tape_kmalloc_buffer(tape, 1, 0);
1964         if (tape->merge_bh != NULL) {
1965                 idetape_pad_zeros(drive, tape->blk_size *
1966                                 (tape->user_bs_factor - 1));
1967                 ide_tape_kfree_buffer(tape);
1968                 tape->merge_bh = NULL;
1969         }
1970         idetape_write_filemark(drive);
1971         idetape_flush_tape_buffers(drive);
1972         idetape_flush_tape_buffers(drive);
1973 }
1974
1975 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1976 {
1977         struct ide_tape_obj *tape = filp->private_data;
1978         ide_drive_t *drive = tape->drive;
1979         unsigned int minor = iminor(inode);
1980
1981         lock_kernel();
1982         tape = drive->driver_data;
1983
1984         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1985
1986         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1987                 idetape_write_release(drive, minor);
1988         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1989                 if (minor < 128)
1990                         ide_tape_discard_merge_buffer(drive, 1);
1991         }
1992
1993         if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags))
1994                 (void) idetape_rewind_tape(drive);
1995         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1996                 if (tape->door_locked == DOOR_LOCKED) {
1997                         if (!ide_set_media_lock(drive, tape->disk, 0))
1998                                 tape->door_locked = DOOR_UNLOCKED;
1999                 }
2000         }
2001         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
2002         ide_tape_put(tape);
2003         unlock_kernel();
2004         return 0;
2005 }
2006
2007 static void idetape_get_inquiry_results(ide_drive_t *drive)
2008 {
2009         idetape_tape_t *tape = drive->driver_data;
2010         struct ide_atapi_pc pc;
2011         u8 pc_buf[256];
2012         char fw_rev[4], vendor_id[8], product_id[16];
2013
2014         idetape_create_inquiry_cmd(&pc);
2015         pc.buf = &pc_buf[0];
2016         pc.buf_size = sizeof(pc_buf);
2017
2018         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
2019                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
2020                                 tape->name);
2021                 return;
2022         }
2023         memcpy(vendor_id, &pc.buf[8], 8);
2024         memcpy(product_id, &pc.buf[16], 16);
2025         memcpy(fw_rev, &pc.buf[32], 4);
2026
2027         ide_fixstring(vendor_id, 8, 0);
2028         ide_fixstring(product_id, 16, 0);
2029         ide_fixstring(fw_rev, 4, 0);
2030
2031         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
2032                         drive->name, tape->name, vendor_id, product_id, fw_rev);
2033 }
2034
2035 /*
2036  * Ask the tape about its various parameters. In particular, we will adjust our
2037  * data transfer buffer size to the recommended value as returned by the tape.
2038  */
2039 static void idetape_get_mode_sense_results(ide_drive_t *drive)
2040 {
2041         idetape_tape_t *tape = drive->driver_data;
2042         struct ide_atapi_pc pc;
2043         u8 *caps;
2044         u8 speed, max_speed;
2045
2046         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
2047         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
2048                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
2049                                 " some default values\n");
2050                 tape->blk_size = 512;
2051                 put_unaligned(52,   (u16 *)&tape->caps[12]);
2052                 put_unaligned(540,  (u16 *)&tape->caps[14]);
2053                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
2054                 return;
2055         }
2056         caps = pc.buf + 4 + pc.buf[3];
2057
2058         /* convert to host order and save for later use */
2059         speed = be16_to_cpup((__be16 *)&caps[14]);
2060         max_speed = be16_to_cpup((__be16 *)&caps[8]);
2061
2062         *(u16 *)&caps[8] = max_speed;
2063         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
2064         *(u16 *)&caps[14] = speed;
2065         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
2066
2067         if (!speed) {
2068                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
2069                                 "(assuming 650KB/sec)\n", drive->name);
2070                 *(u16 *)&caps[14] = 650;
2071         }
2072         if (!max_speed) {
2073                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
2074                                 "(assuming 650KB/sec)\n", drive->name);
2075                 *(u16 *)&caps[8] = 650;
2076         }
2077
2078         memcpy(&tape->caps, caps, 20);
2079
2080         /* device lacks locking support according to capabilities page */
2081         if ((caps[6] & 1) == 0)
2082                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
2083
2084         if (caps[7] & 0x02)
2085                 tape->blk_size = 512;
2086         else if (caps[7] & 0x04)
2087                 tape->blk_size = 1024;
2088 }
2089
2090 #ifdef CONFIG_IDE_PROC_FS
2091 #define ide_tape_devset_get(name, field) \
2092 static int get_##name(ide_drive_t *drive) \
2093 { \
2094         idetape_tape_t *tape = drive->driver_data; \
2095         return tape->field; \
2096 }
2097
2098 #define ide_tape_devset_set(name, field) \
2099 static int set_##name(ide_drive_t *drive, int arg) \
2100 { \
2101         idetape_tape_t *tape = drive->driver_data; \
2102         tape->field = arg; \
2103         return 0; \
2104 }
2105
2106 #define ide_tape_devset_rw_field(_name, _field) \
2107 ide_tape_devset_get(_name, _field) \
2108 ide_tape_devset_set(_name, _field) \
2109 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
2110
2111 #define ide_tape_devset_r_field(_name, _field) \
2112 ide_tape_devset_get(_name, _field) \
2113 IDE_DEVSET(_name, 0, get_##_name, NULL)
2114
2115 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
2116 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
2117 static int divf_buffer(ide_drive_t *drive)      { return    2; }
2118 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
2119
2120 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
2121
2122 ide_tape_devset_rw_field(debug_mask, debug_mask);
2123 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
2124
2125 ide_tape_devset_r_field(avg_speed, avg_speed);
2126 ide_tape_devset_r_field(speed, caps[14]);
2127 ide_tape_devset_r_field(buffer, caps[16]);
2128 ide_tape_devset_r_field(buffer_size, buffer_size);
2129
2130 static const struct ide_proc_devset idetape_settings[] = {
2131         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
2132         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
2133         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
2134         __IDE_PROC_DEVSET(debug_mask,   0, 0xffff, NULL, NULL),
2135         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
2136         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
2137         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
2138                                         mulf_tdsc, divf_tdsc),
2139         { NULL },
2140 };
2141 #endif
2142
2143 /*
2144  * The function below is called to:
2145  *
2146  * 1. Initialize our various state variables.
2147  * 2. Ask the tape for its capabilities.
2148  * 3. Allocate a buffer which will be used for data transfer. The buffer size
2149  * is chosen based on the recommendation which we received in step 2.
2150  *
2151  * Note that at this point ide.c already assigned us an irq, so that we can
2152  * queue requests here and wait for their completion.
2153  */
2154 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
2155 {
2156         unsigned long t;
2157         int speed;
2158         int buffer_size;
2159         u16 *ctl = (u16 *)&tape->caps[12];
2160
2161         drive->pc_callback       = ide_tape_callback;
2162         drive->pc_update_buffers = idetape_update_buffers;
2163         drive->pc_io_buffers     = ide_tape_io_buffers;
2164
2165         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
2166
2167         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
2168                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
2169                                  tape->name);
2170                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
2171         }
2172
2173         /* Seagate Travan drives do not support DSC overlap. */
2174         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
2175                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
2176
2177         tape->minor = minor;
2178         tape->name[0] = 'h';
2179         tape->name[1] = 't';
2180         tape->name[2] = '0' + minor;
2181         tape->chrdev_dir = IDETAPE_DIR_NONE;
2182
2183         idetape_get_inquiry_results(drive);
2184         idetape_get_mode_sense_results(drive);
2185         ide_tape_get_bsize_from_bdesc(drive);
2186         tape->user_bs_factor = 1;
2187         tape->buffer_size = *ctl * tape->blk_size;
2188         while (tape->buffer_size > 0xffff) {
2189                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
2190                 *ctl /= 2;
2191                 tape->buffer_size = *ctl * tape->blk_size;
2192         }
2193         buffer_size = tape->buffer_size;
2194         tape->pages_per_buffer = buffer_size / PAGE_SIZE;
2195         if (buffer_size % PAGE_SIZE) {
2196                 tape->pages_per_buffer++;
2197                 tape->excess_bh_size = PAGE_SIZE - buffer_size % PAGE_SIZE;
2198         }
2199
2200         /* select the "best" DSC read/write polling freq */
2201         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
2202
2203         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
2204
2205         /*
2206          * Ensure that the number we got makes sense; limit it within
2207          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
2208          */
2209         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
2210                                          IDETAPE_DSC_RW_MAX);
2211         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
2212                 "%lums tDSC%s\n",
2213                 drive->name, tape->name, *(u16 *)&tape->caps[14],
2214                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
2215                 tape->buffer_size / 1024,
2216                 tape->best_dsc_rw_freq * 1000 / HZ,
2217                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
2218
2219         ide_proc_register_driver(drive, tape->driver);
2220 }
2221
2222 static void ide_tape_remove(ide_drive_t *drive)
2223 {
2224         idetape_tape_t *tape = drive->driver_data;
2225
2226         ide_proc_unregister_driver(drive, tape->driver);
2227         device_del(&tape->dev);
2228         ide_unregister_region(tape->disk);
2229
2230         mutex_lock(&idetape_ref_mutex);
2231         put_device(&tape->dev);
2232         mutex_unlock(&idetape_ref_mutex);
2233 }
2234
2235 static void ide_tape_release(struct device *dev)
2236 {
2237         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
2238         ide_drive_t *drive = tape->drive;
2239         struct gendisk *g = tape->disk;
2240
2241         BUG_ON(tape->merge_bh_size);
2242
2243         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
2244         drive->driver_data = NULL;
2245         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
2246         device_destroy(idetape_sysfs_class,
2247                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
2248         idetape_devs[tape->minor] = NULL;
2249         g->private_data = NULL;
2250         put_disk(g);
2251         kfree(tape);
2252 }
2253
2254 #ifdef CONFIG_IDE_PROC_FS
2255 static int proc_idetape_read_name
2256         (char *page, char **start, off_t off, int count, int *eof, void *data)
2257 {
2258         ide_drive_t     *drive = (ide_drive_t *) data;
2259         idetape_tape_t  *tape = drive->driver_data;
2260         char            *out = page;
2261         int             len;
2262
2263         len = sprintf(out, "%s\n", tape->name);
2264         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
2265 }
2266
2267 static ide_proc_entry_t idetape_proc[] = {
2268         { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
2269         { "name",       S_IFREG|S_IRUGO,        proc_idetape_read_name, NULL },
2270         { NULL, 0, NULL, NULL }
2271 };
2272
2273 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
2274 {
2275         return idetape_proc;
2276 }
2277
2278 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
2279 {
2280         return idetape_settings;
2281 }
2282 #endif
2283
2284 static int ide_tape_probe(ide_drive_t *);
2285
2286 static struct ide_driver idetape_driver = {
2287         .gen_driver = {
2288                 .owner          = THIS_MODULE,
2289                 .name           = "ide-tape",
2290                 .bus            = &ide_bus_type,
2291         },
2292         .probe                  = ide_tape_probe,
2293         .remove                 = ide_tape_remove,
2294         .version                = IDETAPE_VERSION,
2295         .do_request             = idetape_do_request,
2296 #ifdef CONFIG_IDE_PROC_FS
2297         .proc_entries           = ide_tape_proc_entries,
2298         .proc_devsets           = ide_tape_proc_devsets,
2299 #endif
2300 };
2301
2302 /* Our character device supporting functions, passed to register_chrdev. */
2303 static const struct file_operations idetape_fops = {
2304         .owner          = THIS_MODULE,
2305         .read           = idetape_chrdev_read,
2306         .write          = idetape_chrdev_write,
2307         .ioctl          = idetape_chrdev_ioctl,
2308         .open           = idetape_chrdev_open,
2309         .release        = idetape_chrdev_release,
2310 };
2311
2312 static int idetape_open(struct block_device *bdev, fmode_t mode)
2313 {
2314         struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk);
2315
2316         if (!tape)
2317                 return -ENXIO;
2318
2319         return 0;
2320 }
2321
2322 static int idetape_release(struct gendisk *disk, fmode_t mode)
2323 {
2324         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
2325
2326         ide_tape_put(tape);
2327         return 0;
2328 }
2329
2330 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
2331                         unsigned int cmd, unsigned long arg)
2332 {
2333         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
2334         ide_drive_t *drive = tape->drive;
2335         int err = generic_ide_ioctl(drive, bdev, cmd, arg);
2336         if (err == -EINVAL)
2337                 err = idetape_blkdev_ioctl(drive, cmd, arg);
2338         return err;
2339 }
2340
2341 static struct block_device_operations idetape_block_ops = {
2342         .owner          = THIS_MODULE,
2343         .open           = idetape_open,
2344         .release        = idetape_release,
2345         .locked_ioctl   = idetape_ioctl,
2346 };
2347
2348 static int ide_tape_probe(ide_drive_t *drive)
2349 {
2350         idetape_tape_t *tape;
2351         struct gendisk *g;
2352         int minor;
2353
2354         if (!strstr("ide-tape", drive->driver_req))
2355                 goto failed;
2356
2357         if (drive->media != ide_tape)
2358                 goto failed;
2359
2360         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
2361             ide_check_atapi_device(drive, DRV_NAME) == 0) {
2362                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
2363                                 " the driver\n", drive->name);
2364                 goto failed;
2365         }
2366         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
2367         if (tape == NULL) {
2368                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
2369                                 drive->name);
2370                 goto failed;
2371         }
2372
2373         g = alloc_disk(1 << PARTN_BITS);
2374         if (!g)
2375                 goto out_free_tape;
2376
2377         ide_init_disk(g, drive);
2378
2379         tape->dev.parent = &drive->gendev;
2380         tape->dev.release = ide_tape_release;
2381         dev_set_name(&tape->dev, dev_name(&drive->gendev));
2382
2383         if (device_register(&tape->dev))
2384                 goto out_free_disk;
2385
2386         tape->drive = drive;
2387         tape->driver = &idetape_driver;
2388         tape->disk = g;
2389
2390         g->private_data = &tape->driver;
2391
2392         drive->driver_data = tape;
2393
2394         mutex_lock(&idetape_ref_mutex);
2395         for (minor = 0; idetape_devs[minor]; minor++)
2396                 ;
2397         idetape_devs[minor] = tape;
2398         mutex_unlock(&idetape_ref_mutex);
2399
2400         idetape_setup(drive, tape, minor);
2401
2402         device_create(idetape_sysfs_class, &drive->gendev,
2403                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2404         device_create(idetape_sysfs_class, &drive->gendev,
2405                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2406                       "n%s", tape->name);
2407
2408         g->fops = &idetape_block_ops;
2409         ide_register_region(g);
2410
2411         return 0;
2412
2413 out_free_disk:
2414         put_disk(g);
2415 out_free_tape:
2416         kfree(tape);
2417 failed:
2418         return -ENODEV;
2419 }
2420
2421 static void __exit idetape_exit(void)
2422 {
2423         driver_unregister(&idetape_driver.gen_driver);
2424         class_destroy(idetape_sysfs_class);
2425         unregister_chrdev(IDETAPE_MAJOR, "ht");
2426 }
2427
2428 static int __init idetape_init(void)
2429 {
2430         int error = 1;
2431         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2432         if (IS_ERR(idetape_sysfs_class)) {
2433                 idetape_sysfs_class = NULL;
2434                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2435                 error = -EBUSY;
2436                 goto out;
2437         }
2438
2439         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2440                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2441                                 " interface\n");
2442                 error = -EBUSY;
2443                 goto out_free_class;
2444         }
2445
2446         error = driver_register(&idetape_driver.gen_driver);
2447         if (error)
2448                 goto out_free_driver;
2449
2450         return 0;
2451
2452 out_free_driver:
2453         driver_unregister(&idetape_driver.gen_driver);
2454 out_free_class:
2455         class_destroy(idetape_sysfs_class);
2456 out:
2457         return error;
2458 }
2459
2460 MODULE_ALIAS("ide:*m-tape*");
2461 module_init(idetape_init);
2462 module_exit(idetape_exit);
2463 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2464 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2465 MODULE_LICENSE("GPL");