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/seq_file.h>
  35 #include <linux/slab.h>
  36 #include <linux/pci.h>
  37 #include <linux/ide.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/uaccess.h>
  45 #include <linux/io.h>
  46 #include <asm/unaligned.h>
  47 #include <linux/mtio.h>
  48
  49 /* define to see debug info */
  50 #undef IDETAPE_DEBUG_LOG
  51
  52 #ifdef IDETAPE_DEBUG_LOG
  53 #define ide_debug_log(lvl, fmt, args...) __ide_debug_log(lvl, fmt, ## args)
  54 #else
  55 #define ide_debug_log(lvl, fmt, args...) do {} while (0)
  56 #endif
  57
  58 /**************************** Tunable parameters *****************************/
  59 /*
  60  * After each failed packet command we issue a request sense command and retry
  61  * the packet command IDETAPE_MAX_PC_RETRIES times.
  62  *
  63  * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
  64  */
  65 #define IDETAPE_MAX_PC_RETRIES          3
  66
  67 /*
  68  * The following parameter is used to select the point in the internal tape fifo
  69  * in which we will start to refill the buffer. Decreasing the following
  70  * parameter will improve the system's latency and interactive response, while
  71  * using a high value might improve system throughput.
  72  */
  73 #define IDETAPE_FIFO_THRESHOLD          2
  74
  75 /*
  76  * DSC polling parameters.
  77  *
  78  * Polling for DSC (a single bit in the status register) is a very important
  79  * function in ide-tape. There are two cases in which we poll for DSC:
  80  *
  81  * 1. Before a read/write packet command, to ensure that we can transfer data
  82  * from/to the tape's data buffers, without causing an actual media access.
  83  * In case the tape is not ready yet, we take out our request from the device
  84  * request queue, so that ide.c could service requests from the other device
  85  * on the same interface in the meantime.
  86  *
  87  * 2. After the successful initialization of a "media access packet command",
  88  * which is a command that can take a long time to complete (the interval can
  89  * range from several seconds to even an hour). Again, we postpone our request
  90  * in the middle to free the bus for the other device. The polling frequency
  91  * here should be lower than the read/write frequency since those media access
  92  * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
  93  * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
  94  * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
  95  *
  96  * We also set a timeout for the timer, in case something goes wrong. The
  97  * timeout should be longer then the maximum execution time of a tape operation.
  98  */
  99
 100 /* DSC timings. */
 101 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 102 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 103 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 104 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 105 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 106 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 107 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 108
 109 /*************************** End of tunable parameters ***********************/
 110
 111 /* tape directions */
 112 enum {
 113         IDETAPE_DIR_NONE  = (1 << 0),
 114         IDETAPE_DIR_READ  = (1 << 1),
 115         IDETAPE_DIR_WRITE = (1 << 2),
 116 };
 117
 118 /* Tape door status */
 119 #define DOOR_UNLOCKED                   0
 120 #define DOOR_LOCKED                     1
 121 #define DOOR_EXPLICITLY_LOCKED          2
 122
 123 /* Some defines for the SPACE command */
 124 #define IDETAPE_SPACE_OVER_FILEMARK     1
 125 #define IDETAPE_SPACE_TO_EOD            3
 126
 127 /* Some defines for the LOAD UNLOAD command */
 128 #define IDETAPE_LU_LOAD_MASK            1
 129 #define IDETAPE_LU_RETENSION_MASK       2
 130 #define IDETAPE_LU_EOT_MASK             4
 131
 132 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
 133 #define IDETAPE_BLOCK_DESCRIPTOR        0
 134 #define IDETAPE_CAPABILITIES_PAGE       0x2a
 135
 136 /*
 137  * Most of our global data which we need to save even as we leave the driver due
 138  * to an interrupt or a timer event is stored in the struct defined below.
 139  */
 140 typedef struct ide_tape_obj {
 141         ide_drive_t             *drive;
 142         struct ide_driver       *driver;
 143         struct gendisk          *disk;
 144         struct device           dev;
 145
 146         /* used by REQ_IDETAPE_{READ,WRITE} requests */
 147         struct ide_atapi_pc queued_pc;
 148
 149         /*
 150          * DSC polling variables.
 151          *
 152          * While polling for DSC we use postponed_rq to postpone the current
 153          * request so that ide.c will be able to service pending requests on the
 154          * other device. Note that at most we will have only one DSC (usually
 155          * data transfer) request in the device request queue.
 156          */
 157         bool postponed_rq;
 158
 159         /* The time in which we started polling for DSC */
 160         unsigned long dsc_polling_start;
 161         /* Timer used to poll for dsc */
 162         struct timer_list dsc_timer;
 163         /* Read/Write dsc polling frequency */
 164         unsigned long best_dsc_rw_freq;
 165         unsigned long dsc_poll_freq;
 166         unsigned long dsc_timeout;
 167
 168         /* Read position information */
 169         u8 partition;
 170         /* Current block */
 171         unsigned int first_frame;
 172
 173         /* Last error information */
 174         u8 sense_key, asc, ascq;
 175
 176         /* Character device operation */
 177         unsigned int minor;
 178         /* device name */
 179         char name[4];
 180         /* Current character device data transfer direction */
 181         u8 chrdev_dir;
 182
 183         /* tape block size, usually 512 or 1024 bytes */
 184         unsigned short blk_size;
 185         int user_bs_factor;
 186
 187         /* Copy of the tape's Capabilities and Mechanical Page */
 188         u8 caps[20];
 189
 190         /*
 191          * Active data transfer request parameters.
 192          *
 193          * At most, there is only one ide-tape originated data transfer request
 194          * in the device request queue. This allows ide.c to easily service
 195          * requests from the other device when we postpone our active request.
 196          */
 197
 198         /* Data buffer size chosen based on the tape's recommendation */
 199         int buffer_size;
 200         /* Staging buffer of buffer_size bytes */
 201         void *buf;
 202         /* The read/write cursor */
 203         void *cur;
 204         /* The number of valid bytes in buf */
 205         size_t valid;
 206
 207         /* Measures average tape speed */
 208         unsigned long avg_time;
 209         int avg_size;
 210         int avg_speed;
 211
 212         /* the door is currently locked */
 213         int door_locked;
 214         /* the tape hardware is write protected */
 215         char drv_write_prot;
 216         /* the tape is write protected (hardware or opened as read-only) */
 217         char write_prot;
 218 } idetape_tape_t;
 219
 220 static DEFINE_MUTEX(ide_tape_mutex);
 221 static DEFINE_MUTEX(idetape_ref_mutex);
 222
 223 static DEFINE_MUTEX(idetape_chrdev_mutex);
 224
 225 static struct class *idetape_sysfs_class;
 226
 227 static void ide_tape_release(struct device *);
 228
 229 static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
 230
 231 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk, bool cdev,
 232                                          unsigned int i)
 233 {
 234         struct ide_tape_obj *tape = NULL;
 235
 236         mutex_lock(&idetape_ref_mutex);
 237
 238         if (cdev)
 239                 tape = idetape_devs[i];
 240         else
 241                 tape = ide_drv_g(disk, ide_tape_obj);
 242
 243         if (tape) {
 244                 if (ide_device_get(tape->drive))
 245                         tape = NULL;
 246                 else
 247                         get_device(&tape->dev);
 248         }
 249
 250         mutex_unlock(&idetape_ref_mutex);
 251         return tape;
 252 }
 253
 254 static void ide_tape_put(struct ide_tape_obj *tape)
 255 {
 256         ide_drive_t *drive = tape->drive;
 257
 258         mutex_lock(&idetape_ref_mutex);
 259         put_device(&tape->dev);
 260         ide_device_put(drive);
 261         mutex_unlock(&idetape_ref_mutex);
 262 }
 263
 264 /*
 265  * called on each failed packet command retry to analyze the request sense. We
 266  * currently do not utilize this information.
 267  */
 268 static void idetape_analyze_error(ide_drive_t *drive)
 269 {
 270         idetape_tape_t *tape = drive->driver_data;
 271         struct ide_atapi_pc *pc = drive->failed_pc;
 272         struct request *rq = drive->hwif->rq;
 273         u8 *sense = bio_data(rq->bio);
 274
 275         tape->sense_key = sense[2] & 0xF;
 276         tape->asc       = sense[12];
 277         tape->ascq      = sense[13];
 278
 279         ide_debug_log(IDE_DBG_FUNC,
 280                       "cmd: 0x%x, sense key = %x, asc = %x, ascq = %x",
 281                       rq->cmd[0], tape->sense_key, tape->asc, tape->ascq);
 282
 283         /* correct remaining bytes to transfer */
 284         if (pc->flags & PC_FLAG_DMA_ERROR)
 285                 scsi_req(rq)->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
 286
 287         /*
 288          * If error was the result of a zero-length read or write command,
 289          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
 290          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
 291          */
 292         if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
 293             /* length == 0 */
 294             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
 295                 if (tape->sense_key == 5) {
 296                         /* don't report an error, everything's ok */
 297                         pc->error = 0;
 298                         /* don't retry read/write */
 299                         pc->flags |= PC_FLAG_ABORT;
 300                 }
 301         }
 302         if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
 303                 pc->error = IDE_DRV_ERROR_FILEMARK;
 304                 pc->flags |= PC_FLAG_ABORT;
 305         }
 306         if (pc->c[0] == WRITE_6) {
 307                 if ((sense[2] & 0x40) || (tape->sense_key == 0xd
 308                      && tape->asc == 0x0 && tape->ascq == 0x2)) {
 309                         pc->error = IDE_DRV_ERROR_EOD;
 310                         pc->flags |= PC_FLAG_ABORT;
 311                 }
 312         }
 313         if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 314                 if (tape->sense_key == 8) {
 315                         pc->error = IDE_DRV_ERROR_EOD;
 316                         pc->flags |= PC_FLAG_ABORT;
 317                 }
 318                 if (!(pc->flags & PC_FLAG_ABORT) &&
 319                     (blk_rq_bytes(rq) - scsi_req(rq)->resid_len))
 320                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
 321         }
 322 }
 323
 324 static void ide_tape_handle_dsc(ide_drive_t *);
 325
 326 static int ide_tape_callback(ide_drive_t *drive, int dsc)
 327 {
 328         idetape_tape_t *tape = drive->driver_data;
 329         struct ide_atapi_pc *pc = drive->pc;
 330         struct request *rq = drive->hwif->rq;
 331         int uptodate = pc->error ? 0 : 1;
 332         int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 333
 334         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc: %d, err: %d", rq->cmd[0],
 335                       dsc, err);
 336
 337         if (dsc)
 338                 ide_tape_handle_dsc(drive);
 339
 340         if (drive->failed_pc == pc)
 341                 drive->failed_pc = NULL;
 342
 343         if (pc->c[0] == REQUEST_SENSE) {
 344                 if (uptodate)
 345                         idetape_analyze_error(drive);
 346                 else
 347                         printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
 348                                         "itself - Aborting request!\n");
 349         } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 350                 unsigned int blocks =
 351                         (blk_rq_bytes(rq) - scsi_req(rq)->resid_len) / tape->blk_size;
 352
 353                 tape->avg_size += blocks * tape->blk_size;
 354
 355                 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
 356                         tape->avg_speed = tape->avg_size * HZ /
 357                                 (jiffies - tape->avg_time) / 1024;
 358                         tape->avg_size = 0;
 359                         tape->avg_time = jiffies;
 360                 }
 361
 362                 tape->first_frame += blocks;
 363
 364                 if (pc->error) {
 365                         uptodate = 0;
 366                         err = pc->error;
 367                 }
 368         }
 369         scsi_req(rq)->result = err;
 370
 371         return uptodate;
 372 }
 373
 374 /*
 375  * Postpone the current request so that ide.c will be able to service requests
 376  * from another device on the same port while we are polling for DSC.
 377  */
 378 static void ide_tape_stall_queue(ide_drive_t *drive)
 379 {
 380         idetape_tape_t *tape = drive->driver_data;
 381
 382         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc_poll_freq: %lu",
 383                       drive->hwif->rq->cmd[0], tape->dsc_poll_freq);
 384
 385         tape->postponed_rq = true;
 386
 387         ide_stall_queue(drive, tape->dsc_poll_freq);
 388 }
 389
 390 static void ide_tape_handle_dsc(ide_drive_t *drive)
 391 {
 392         idetape_tape_t *tape = drive->driver_data;
 393
 394         /* Media access command */
 395         tape->dsc_polling_start = jiffies;
 396         tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
 397         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
 398         /* Allow ide.c to handle other requests */
 399         ide_tape_stall_queue(drive);
 400 }
 401
 402 /*
 403  * Packet Command Interface
 404  *
 405  * The current Packet Command is available in drive->pc, and will not change
 406  * until we finish handling it. Each packet command is associated with a
 407  * callback function that will be called when the command is finished.
 408  *
 409  * The handling will be done in three stages:
 410  *
 411  * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
 412  * the interrupt handler to ide_pc_intr.
 413  *
 414  * 2. On each interrupt, ide_pc_intr will be called. This step will be
 415  * repeated until the device signals us that no more interrupts will be issued.
 416  *
 417  * 3. ATAPI Tape media access commands have immediate status with a delayed
 418  * process. In case of a successful initiation of a media access packet command,
 419  * the DSC bit will be set when the actual execution of the command is finished.
 420  * Since the tape drive will not issue an interrupt, we have to poll for this
 421  * event. In this case, we define the request as "low priority request" by
 422  * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 423  * exit the driver.
 424  *
 425  * ide.c will then give higher priority to requests which originate from the
 426  * other device, until will change rq_status to RQ_ACTIVE.
 427  *
 428  * 4. When the packet command is finished, it will be checked for errors.
 429  *
 430  * 5. In case an error was found, we queue a request sense packet command in
 431  * front of the request queue and retry the operation up to
 432  * IDETAPE_MAX_PC_RETRIES times.
 433  *
 434  * 6. In case no error was found, or we decided to give up and not to retry
 435  * again, the callback function will be called and then we will handle the next
 436  * request.
 437  */
 438
 439 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 440                                          struct ide_cmd *cmd,
 441                                          struct ide_atapi_pc *pc)
 442 {
 443         idetape_tape_t *tape = drive->driver_data;
 444         struct request *rq = drive->hwif->rq;
 445
 446         if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
 447                 drive->failed_pc = pc;
 448
 449         /* Set the current packet command */
 450         drive->pc = pc;
 451
 452         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
 453                 (pc->flags & PC_FLAG_ABORT)) {
 454
 455                 /*
 456                  * We will "abort" retrying a packet command in case legitimate
 457                  * error code was received (crossing a filemark, or end of the
 458                  * media, for example).
 459                  */
 460                 if (!(pc->flags & PC_FLAG_ABORT)) {
 461                         if (!(pc->c[0] == TEST_UNIT_READY &&
 462                               tape->sense_key == 2 && tape->asc == 4 &&
 463                              (tape->ascq == 1 || tape->ascq == 8))) {
 464                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
 465                                                 "pc = %2x, key = %2x, "
 466                                                 "asc = %2x, ascq = %2x\n",
 467                                                 tape->name, pc->c[0],
 468                                                 tape->sense_key, tape->asc,
 469                                                 tape->ascq);
 470                         }
 471                         /* Giving up */
 472                         pc->error = IDE_DRV_ERROR_GENERAL;
 473                 }
 474
 475                 drive->failed_pc = NULL;
 476                 drive->pc_callback(drive, 0);
 477                 ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(rq));
 478                 return ide_stopped;
 479         }
 480         ide_debug_log(IDE_DBG_SENSE, "retry #%d, cmd: 0x%02x", pc->retries,
 481                       pc->c[0]);
 482
 483         pc->retries++;
 484
 485         return ide_issue_pc(drive, cmd);
 486 }
 487
 488 /* A mode sense command is used to "sense" tape parameters. */
 489 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 490 {
 491         ide_init_pc(pc);
 492         pc->c[0] = MODE_SENSE;
 493         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
 494                 /* DBD = 1 - Don't return block descriptors */
 495                 pc->c[1] = 8;
 496         pc->c[2] = page_code;
 497         /*
 498          * Changed pc->c[3] to 0 (255 will at best return unused info).
 499          *
 500          * For SCSI this byte is defined as subpage instead of high byte
 501          * of length and some IDE drives seem to interpret it this way
 502          * and return an error when 255 is used.
 503          */
 504         pc->c[3] = 0;
 505         /* We will just discard data in that case */
 506         pc->c[4] = 255;
 507         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
 508                 pc->req_xfer = 12;
 509         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
 510                 pc->req_xfer = 24;
 511         else
 512                 pc->req_xfer = 50;
 513 }
 514
 515 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 516 {
 517         ide_hwif_t *hwif = drive->hwif;
 518         idetape_tape_t *tape = drive->driver_data;
 519         struct ide_atapi_pc *pc = drive->pc;
 520         u8 stat;
 521
 522         stat = hwif->tp_ops->read_status(hwif);
 523
 524         if (stat & ATA_DSC) {
 525                 if (stat & ATA_ERR) {
 526                         /* Error detected */
 527                         if (pc->c[0] != TEST_UNIT_READY)
 528                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
 529                                                 tape->name);
 530                         /* Retry operation */
 531                         ide_retry_pc(drive);
 532                         return ide_stopped;
 533                 }
 534                 pc->error = 0;
 535         } else {
 536                 pc->error = IDE_DRV_ERROR_GENERAL;
 537                 drive->failed_pc = NULL;
 538         }
 539         drive->pc_callback(drive, 0);
 540         return ide_stopped;
 541 }
 542
 543 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
 544                                    struct ide_atapi_pc *pc, struct request *rq,
 545                                    u8 opcode)
 546 {
 547         unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
 548
 549         ide_init_pc(pc);
 550         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
 551         pc->c[1] = 1;
 552
 553         if (blk_rq_bytes(rq) == tape->buffer_size)
 554                 pc->flags |= PC_FLAG_DMA_OK;
 555
 556         if (opcode == READ_6)
 557                 pc->c[0] = READ_6;
 558         else if (opcode == WRITE_6) {
 559                 pc->c[0] = WRITE_6;
 560                 pc->flags |= PC_FLAG_WRITING;
 561         }
 562
 563         memcpy(scsi_req(rq)->cmd, pc->c, 12);
 564 }
 565
 566 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 567                                           struct request *rq, sector_t block)
 568 {
 569         ide_hwif_t *hwif = drive->hwif;
 570         idetape_tape_t *tape = drive->driver_data;
 571         struct ide_atapi_pc *pc = NULL;
 572         struct ide_cmd cmd;
 573         struct scsi_request *req = scsi_req(rq);
 574         u8 stat;
 575
 576         ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, sector: %llu, nr_sectors: %u",
 577                       req->cmd[0], (unsigned long long)blk_rq_pos(rq),
 578                       blk_rq_sectors(rq));
 579
 580         BUG_ON(!blk_rq_is_private(rq));
 581         BUG_ON(ide_req(rq)->type != ATA_PRIV_MISC &&
 582                ide_req(rq)->type != ATA_PRIV_SENSE);
 583
 584         /* Retry a failed packet command */
 585         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 586                 pc = drive->failed_pc;
 587                 goto out;
 588         }
 589
 590         /*
 591          * If the tape is still busy, postpone our request and service
 592          * the other device meanwhile.
 593          */
 594         stat = hwif->tp_ops->read_status(hwif);
 595
 596         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 597             (req->cmd[13] & REQ_IDETAPE_PC2) == 0)
 598                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 599
 600         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 601                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 602                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 603         }
 604
 605         if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
 606             !(stat & ATA_DSC)) {
 607                 if (!tape->postponed_rq) {
 608                         tape->dsc_polling_start = jiffies;
 609                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 610                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 611                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 612                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 613                                 tape->name);
 614                         if (req->cmd[13] & REQ_IDETAPE_PC2) {
 615                                 idetape_media_access_finished(drive);
 616                                 return ide_stopped;
 617                         } else {
 618                                 return ide_do_reset(drive);
 619                         }
 620                 } else if (time_after(jiffies,
 621                                         tape->dsc_polling_start +
 622                                         IDETAPE_DSC_MA_THRESHOLD))
 623                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 624                 ide_tape_stall_queue(drive);
 625                 return ide_stopped;
 626         } else {
 627                 drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
 628                 tape->postponed_rq = false;
 629         }
 630
 631         if (req->cmd[13] & REQ_IDETAPE_READ) {
 632                 pc = &tape->queued_pc;
 633                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 634                 goto out;
 635         }
 636         if (req->cmd[13] & REQ_IDETAPE_WRITE) {
 637                 pc = &tape->queued_pc;
 638                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 639                 goto out;
 640         }
 641         if (req->cmd[13] & REQ_IDETAPE_PC1) {
 642                 pc = (struct ide_atapi_pc *)rq->special;
 643                 req->cmd[13] &= ~(REQ_IDETAPE_PC1);
 644                 req->cmd[13] |= REQ_IDETAPE_PC2;
 645                 goto out;
 646         }
 647         if (req->cmd[13] & REQ_IDETAPE_PC2) {
 648                 idetape_media_access_finished(drive);
 649                 return ide_stopped;
 650         }
 651         BUG();
 652
 653 out:
 654         /* prepare sense request for this command */
 655         ide_prep_sense(drive, rq);
 656
 657         memset(&cmd, 0, sizeof(cmd));
 658
 659         if (rq_data_dir(rq))
 660                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 661
 662         cmd.rq = rq;
 663
 664         ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
 665         ide_map_sg(drive, &cmd);
 666
 667         return ide_tape_issue_pc(drive, &cmd, pc);
 668 }
 669
 670 /*
 671  * Write a filemark if write_filemark=1. Flush the device buffers without
 672  * writing a filemark otherwise.
 673  */
 674 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 675                 struct ide_atapi_pc *pc, int write_filemark)
 676 {
 677         ide_init_pc(pc);
 678         pc->c[0] = WRITE_FILEMARKS;
 679         pc->c[4] = write_filemark;
 680         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 681 }
 682
 683 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 684 {
 685         idetape_tape_t *tape = drive->driver_data;
 686         struct gendisk *disk = tape->disk;
 687         int load_attempted = 0;
 688
 689         /* Wait for the tape to become ready */
 690         set_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT), &drive->atapi_flags);
 691         timeout += jiffies;
 692         while (time_before(jiffies, timeout)) {
 693                 if (ide_do_test_unit_ready(drive, disk) == 0)
 694                         return 0;
 695                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 696                     || (tape->asc == 0x3A)) {
 697                         /* no media */
 698                         if (load_attempted)
 699                                 return -ENOMEDIUM;
 700                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 701                         load_attempted = 1;
 702                 /* not about to be ready */
 703                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 704                              (tape->ascq == 1 || tape->ascq == 8)))
 705                         return -EIO;
 706                 msleep(100);
 707         }
 708         return -EIO;
 709 }
 710
 711 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 712 {
 713         struct ide_tape_obj *tape = drive->driver_data;
 714         struct ide_atapi_pc pc;
 715         int rc;
 716
 717         idetape_create_write_filemark_cmd(drive, &pc, 0);
 718         rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
 719         if (rc)
 720                 return rc;
 721         idetape_wait_ready(drive, 60 * 5 * HZ);
 722         return 0;
 723 }
 724
 725 static int ide_tape_read_position(ide_drive_t *drive)
 726 {
 727         idetape_tape_t *tape = drive->driver_data;
 728         struct ide_atapi_pc pc;
 729         u8 buf[20];
 730
 731         ide_debug_log(IDE_DBG_FUNC, "enter");
 732
 733         /* prep cmd */
 734         ide_init_pc(&pc);
 735         pc.c[0] = READ_POSITION;
 736         pc.req_xfer = 20;
 737
 738         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
 739                 return -1;
 740
 741         if (!pc.error) {
 742                 ide_debug_log(IDE_DBG_FUNC, "BOP - %s",
 743                                 (buf[0] & 0x80) ? "Yes" : "No");
 744                 ide_debug_log(IDE_DBG_FUNC, "EOP - %s",
 745                                 (buf[0] & 0x40) ? "Yes" : "No");
 746
 747                 if (buf[0] & 0x4) {
 748                         printk(KERN_INFO "ide-tape: Block location is unknown"
 749                                          "to the tape\n");
 750                         clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 751                                   &drive->atapi_flags);
 752                         return -1;
 753                 } else {
 754                         ide_debug_log(IDE_DBG_FUNC, "Block Location: %u",
 755                                       be32_to_cpup((__be32 *)&buf[4]));
 756
 757                         tape->partition = buf[1];
 758                         tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
 759                         set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 760                                 &drive->atapi_flags);
 761                 }
 762         }
 763
 764         return tape->first_frame;
 765 }
 766
 767 static void idetape_create_locate_cmd(ide_drive_t *drive,
 768                 struct ide_atapi_pc *pc,
 769                 unsigned int block, u8 partition, int skip)
 770 {
 771         ide_init_pc(pc);
 772         pc->c[0] = POSITION_TO_ELEMENT;
 773         pc->c[1] = 2;
 774         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 775         pc->c[8] = partition;
 776         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 777 }
 778
 779 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 780 {
 781         idetape_tape_t *tape = drive->driver_data;
 782
 783         if (tape->chrdev_dir != IDETAPE_DIR_READ)
 784                 return;
 785
 786         clear_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
 787         tape->valid = 0;
 788         if (tape->buf != NULL) {
 789                 kfree(tape->buf);
 790                 tape->buf = NULL;
 791         }
 792
 793         tape->chrdev_dir = IDETAPE_DIR_NONE;
 794 }
 795
 796 /*
 797  * Position the tape to the requested block using the LOCATE packet command.
 798  * A READ POSITION command is then issued to check where we are positioned. Like
 799  * all higher level operations, we queue the commands at the tail of the request
 800  * queue and wait for their completion.
 801  */
 802 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 803                 u8 partition, int skip)
 804 {
 805         idetape_tape_t *tape = drive->driver_data;
 806         struct gendisk *disk = tape->disk;
 807         int ret;
 808         struct ide_atapi_pc pc;
 809
 810         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 811                 __ide_tape_discard_merge_buffer(drive);
 812         idetape_wait_ready(drive, 60 * 5 * HZ);
 813         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 814         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 815         if (ret)
 816                 return ret;
 817
 818         ret = ide_tape_read_position(drive);
 819         if (ret < 0)
 820                 return ret;
 821         return 0;
 822 }
 823
 824 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 825                                           int restore_position)
 826 {
 827         idetape_tape_t *tape = drive->driver_data;
 828         int seek, position;
 829
 830         __ide_tape_discard_merge_buffer(drive);
 831         if (restore_position) {
 832                 position = ide_tape_read_position(drive);
 833                 seek = position > 0 ? position : 0;
 834                 if (idetape_position_tape(drive, seek, 0, 0)) {
 835                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 836                                          " %s\n", tape->name, __func__);
 837                         return;
 838                 }
 839         }
 840 }
 841
 842 /*
 843  * Generate a read/write request for the block device interface and wait for it
 844  * to be serviced.
 845  */
 846 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 847 {
 848         idetape_tape_t *tape = drive->driver_data;
 849         struct request *rq;
 850         int ret;
 851
 852         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, size: %d", cmd, size);
 853
 854         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 855         BUG_ON(size < 0 || size % tape->blk_size);
 856
 857         rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
 858         scsi_req_init(rq);
 859         ide_req(rq)->type = ATA_PRIV_MISC;
 860         scsi_req(rq)->cmd[13] = cmd;
 861         rq->rq_disk = tape->disk;
 862         rq->__sector = tape->first_frame;
 863
 864         if (size) {
 865                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 866                                       __GFP_RECLAIM);
 867                 if (ret)
 868                         goto out_put;
 869         }
 870
 871         blk_execute_rq(drive->queue, tape->disk, rq, 0);
 872
 873         /* calculate the number of transferred bytes and update buffer state */
 874         size -= scsi_req(rq)->resid_len;
 875         tape->cur = tape->buf;
 876         if (cmd == REQ_IDETAPE_READ)
 877                 tape->valid = size;
 878         else
 879                 tape->valid = 0;
 880
 881         ret = size;
 882         if (scsi_req(rq)->result == IDE_DRV_ERROR_GENERAL)
 883                 ret = -EIO;
 884 out_put:
 885         blk_put_request(rq);
 886         return ret;
 887 }
 888
 889 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 890 {
 891         ide_init_pc(pc);
 892         pc->c[0] = INQUIRY;
 893         pc->c[4] = 254;
 894         pc->req_xfer = 254;
 895 }
 896
 897 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 898                 struct ide_atapi_pc *pc)
 899 {
 900         ide_init_pc(pc);
 901         pc->c[0] = REZERO_UNIT;
 902         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 903 }
 904
 905 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 906 {
 907         ide_init_pc(pc);
 908         pc->c[0] = ERASE;
 909         pc->c[1] = 1;
 910         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 911 }
 912
 913 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 914 {
 915         ide_init_pc(pc);
 916         pc->c[0] = SPACE;
 917         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 918         pc->c[1] = cmd;
 919         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 920 }
 921
 922 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 923 {
 924         idetape_tape_t *tape = drive->driver_data;
 925
 926         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 927                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 928                                 " but we are not writing.\n");
 929                 return;
 930         }
 931         if (tape->buf) {
 932                 size_t aligned = roundup(tape->valid, tape->blk_size);
 933
 934                 memset(tape->cur, 0, aligned - tape->valid);
 935                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 936                 kfree(tape->buf);
 937                 tape->buf = NULL;
 938         }
 939         tape->chrdev_dir = IDETAPE_DIR_NONE;
 940 }
 941
 942 static int idetape_init_rw(ide_drive_t *drive, int dir)
 943 {
 944         idetape_tape_t *tape = drive->driver_data;
 945         int rc;
 946
 947         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 948
 949         if (tape->chrdev_dir == dir)
 950                 return 0;
 951
 952         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 953                 ide_tape_discard_merge_buffer(drive, 1);
 954         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 955                 ide_tape_flush_merge_buffer(drive);
 956                 idetape_flush_tape_buffers(drive);
 957         }
 958
 959         if (tape->buf || tape->valid) {
 960                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 961                 tape->valid = 0;
 962         }
 963
 964         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 965         if (!tape->buf)
 966                 return -ENOMEM;
 967         tape->chrdev_dir = dir;
 968         tape->cur = tape->buf;
 969
 970         /*
 971          * Issue a 0 rw command to ensure that DSC handshake is
 972          * switched from completion mode to buffer available mode.  No
 973          * point in issuing this if DSC overlap isn't supported, some
 974          * drives (Seagate STT3401A) will return an error.
 975          */
 976         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
 977                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
 978                                                   : REQ_IDETAPE_WRITE;
 979
 980                 rc = idetape_queue_rw_tail(drive, cmd, 0);
 981                 if (rc < 0) {
 982                         kfree(tape->buf);
 983                         tape->buf = NULL;
 984                         tape->chrdev_dir = IDETAPE_DIR_NONE;
 985                         return rc;
 986                 }
 987         }
 988
 989         return 0;
 990 }
 991
 992 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
 993 {
 994         idetape_tape_t *tape = drive->driver_data;
 995
 996         memset(tape->buf, 0, tape->buffer_size);
 997
 998         while (bcount) {
 999                 unsigned int count = min(tape->buffer_size, bcount);
1000
1001                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1002                 bcount -= count;
1003         }
1004 }
1005
1006 /*
1007  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1008  * currently support only one partition.
1009  */
1010 static int idetape_rewind_tape(ide_drive_t *drive)
1011 {
1012         struct ide_tape_obj *tape = drive->driver_data;
1013         struct gendisk *disk = tape->disk;
1014         struct ide_atapi_pc pc;
1015         int ret;
1016
1017         ide_debug_log(IDE_DBG_FUNC, "enter");
1018
1019         idetape_create_rewind_cmd(drive, &pc);
1020         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1021         if (ret)
1022                 return ret;
1023
1024         ret = ide_tape_read_position(drive);
1025         if (ret < 0)
1026                 return ret;
1027         return 0;
1028 }
1029
1030 /* mtio.h compatible commands should be issued to the chrdev interface. */
1031 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1032                                 unsigned long arg)
1033 {
1034         idetape_tape_t *tape = drive->driver_data;
1035         void __user *argp = (void __user *)arg;
1036
1037         struct idetape_config {
1038                 int dsc_rw_frequency;
1039                 int dsc_media_access_frequency;
1040                 int nr_stages;
1041         } config;
1042
1043         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%04x", cmd);
1044
1045         switch (cmd) {
1046         case 0x0340:
1047                 if (copy_from_user(&config, argp, sizeof(config)))
1048                         return -EFAULT;
1049                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1050                 break;
1051         case 0x0350:
1052                 memset(&config, 0, sizeof(config));
1053                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1054                 config.nr_stages = 1;
1055                 if (copy_to_user(argp, &config, sizeof(config)))
1056                         return -EFAULT;
1057                 break;
1058         default:
1059                 return -EIO;
1060         }
1061         return 0;
1062 }
1063
1064 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1065                                         int mt_count)
1066 {
1067         idetape_tape_t *tape = drive->driver_data;
1068         struct gendisk *disk = tape->disk;
1069         struct ide_atapi_pc pc;
1070         int retval, count = 0;
1071         int sprev = !!(tape->caps[4] & 0x20);
1072
1073
1074         ide_debug_log(IDE_DBG_FUNC, "mt_op: %d, mt_count: %d", mt_op, mt_count);
1075
1076         if (mt_count == 0)
1077                 return 0;
1078         if (MTBSF == mt_op || MTBSFM == mt_op) {
1079                 if (!sprev)
1080                         return -EIO;
1081                 mt_count = -mt_count;
1082         }
1083
1084         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1085                 tape->valid = 0;
1086                 if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1087                                        &drive->atapi_flags))
1088                         ++count;
1089                 ide_tape_discard_merge_buffer(drive, 0);
1090         }
1091
1092         switch (mt_op) {
1093         case MTFSF:
1094         case MTBSF:
1095                 idetape_create_space_cmd(&pc, mt_count - count,
1096                                          IDETAPE_SPACE_OVER_FILEMARK);
1097                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1098         case MTFSFM:
1099         case MTBSFM:
1100                 if (!sprev)
1101                         return -EIO;
1102                 retval = idetape_space_over_filemarks(drive, MTFSF,
1103                                                       mt_count - count);
1104                 if (retval)
1105                         return retval;
1106                 count = (MTBSFM == mt_op ? 1 : -1);
1107                 return idetape_space_over_filemarks(drive, MTFSF, count);
1108         default:
1109                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1110                                 mt_op);
1111                 return -EIO;
1112         }
1113 }
1114
1115 /*
1116  * Our character device read / write functions.
1117  *
1118  * The tape is optimized to maximize throughput when it is transferring an
1119  * integral number of the "continuous transfer limit", which is a parameter of
1120  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1121  *
1122  * As of version 1.3 of the driver, the character device provides an abstract
1123  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1124  * same backup/restore procedure is supported. The driver will internally
1125  * convert the requests to the recommended transfer unit, so that an unmatch
1126  * between the user's block size to the recommended size will only result in a
1127  * (slightly) increased driver overhead, but will no longer hit performance.
1128  * This is not applicable to Onstream.
1129  */
1130 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1131                                    size_t count, loff_t *ppos)
1132 {
1133         struct ide_tape_obj *tape = file->private_data;
1134         ide_drive_t *drive = tape->drive;
1135         size_t done = 0;
1136         ssize_t ret = 0;
1137         int rc;
1138
1139         ide_debug_log(IDE_DBG_FUNC, "count %zd", count);
1140
1141         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1142                 if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1143                         if (count > tape->blk_size &&
1144                             (count % tape->blk_size) == 0)
1145                                 tape->user_bs_factor = count / tape->blk_size;
1146         }
1147
1148         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1149         if (rc < 0)
1150                 return rc;
1151
1152         while (done < count) {
1153                 size_t todo;
1154
1155                 /* refill if staging buffer is empty */
1156                 if (!tape->valid) {
1157                         /* If we are at a filemark, nothing more to read */
1158                         if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1159                                      &drive->atapi_flags))
1160                                 break;
1161                         /* read */
1162                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1163                                                   tape->buffer_size) <= 0)
1164                                 break;
1165                 }
1166
1167                 /* copy out */
1168                 todo = min_t(size_t, count - done, tape->valid);
1169                 if (copy_to_user(buf + done, tape->cur, todo))
1170                         ret = -EFAULT;
1171
1172                 tape->cur += todo;
1173                 tape->valid -= todo;
1174                 done += todo;
1175         }
1176
1177         if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1178                 idetape_space_over_filemarks(drive, MTFSF, 1);
1179                 return 0;
1180         }
1181
1182         return ret ? ret : done;
1183 }
1184
1185 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1186                                      size_t count, loff_t *ppos)
1187 {
1188         struct ide_tape_obj *tape = file->private_data;
1189         ide_drive_t *drive = tape->drive;
1190         size_t done = 0;
1191         ssize_t ret = 0;
1192         int rc;
1193
1194         /* The drive is write protected. */
1195         if (tape->write_prot)
1196                 return -EACCES;
1197
1198         ide_debug_log(IDE_DBG_FUNC, "count %zd", count);
1199
1200         /* Initialize write operation */
1201         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1202         if (rc < 0)
1203                 return rc;
1204
1205         while (done < count) {
1206                 size_t todo;
1207
1208                 /* flush if staging buffer is full */
1209                 if (tape->valid == tape->buffer_size &&
1210                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1211                                           tape->buffer_size) <= 0)
1212                         return rc;
1213
1214                 /* copy in */
1215                 todo = min_t(size_t, count - done,
1216                              tape->buffer_size - tape->valid);
1217                 if (copy_from_user(tape->cur, buf + done, todo))
1218                         ret = -EFAULT;
1219
1220                 tape->cur += todo;
1221                 tape->valid += todo;
1222                 done += todo;
1223         }
1224
1225         return ret ? ret : done;
1226 }
1227
1228 static int idetape_write_filemark(ide_drive_t *drive)
1229 {
1230         struct ide_tape_obj *tape = drive->driver_data;
1231         struct ide_atapi_pc pc;
1232
1233         /* Write a filemark */
1234         idetape_create_write_filemark_cmd(drive, &pc, 1);
1235         if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1236                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1237                 return -EIO;
1238         }
1239         return 0;
1240 }
1241
1242 /*
1243  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1244  * requested.
1245  *
1246  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1247  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1248  * usually not supported.
1249  *
1250  * The following commands are currently not supported:
1251  *
1252  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1253  * MT_ST_WRITE_THRESHOLD.
1254  */
1255 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1256 {
1257         idetape_tape_t *tape = drive->driver_data;
1258         struct gendisk *disk = tape->disk;
1259         struct ide_atapi_pc pc;
1260         int i, retval;
1261
1262         ide_debug_log(IDE_DBG_FUNC, "MTIOCTOP ioctl: mt_op: %d, mt_count: %d",
1263                       mt_op, mt_count);
1264
1265         switch (mt_op) {
1266         case MTFSF:
1267         case MTFSFM:
1268         case MTBSF:
1269         case MTBSFM:
1270                 if (!mt_count)
1271                         return 0;
1272                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1273         default:
1274                 break;
1275         }
1276
1277         switch (mt_op) {
1278         case MTWEOF:
1279                 if (tape->write_prot)
1280                         return -EACCES;
1281                 ide_tape_discard_merge_buffer(drive, 1);
1282                 for (i = 0; i < mt_count; i++) {
1283                         retval = idetape_write_filemark(drive);
1284                         if (retval)
1285                                 return retval;
1286                 }
1287                 return 0;
1288         case MTREW:
1289                 ide_tape_discard_merge_buffer(drive, 0);
1290                 if (idetape_rewind_tape(drive))
1291                         return -EIO;
1292                 return 0;
1293         case MTLOAD:
1294                 ide_tape_discard_merge_buffer(drive, 0);
1295                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1296         case MTUNLOAD:
1297         case MTOFFL:
1298                 /*
1299                  * If door is locked, attempt to unlock before
1300                  * attempting to eject.
1301                  */
1302                 if (tape->door_locked) {
1303                         if (!ide_set_media_lock(drive, disk, 0))
1304                                 tape->door_locked = DOOR_UNLOCKED;
1305                 }
1306                 ide_tape_discard_merge_buffer(drive, 0);
1307                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1308                 if (!retval)
1309                         clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1310                                   &drive->atapi_flags);
1311                 return retval;
1312         case MTNOP:
1313                 ide_tape_discard_merge_buffer(drive, 0);
1314                 return idetape_flush_tape_buffers(drive);
1315         case MTRETEN:
1316                 ide_tape_discard_merge_buffer(drive, 0);
1317                 return ide_do_start_stop(drive, disk,
1318                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1319         case MTEOM:
1320                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1321                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1322         case MTERASE:
1323                 (void)idetape_rewind_tape(drive);
1324                 idetape_create_erase_cmd(&pc);
1325                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1326         case MTSETBLK:
1327                 if (mt_count) {
1328                         if (mt_count < tape->blk_size ||
1329                             mt_count % tape->blk_size)
1330                                 return -EIO;
1331                         tape->user_bs_factor = mt_count / tape->blk_size;
1332                         clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1333                                   &drive->atapi_flags);
1334                 } else
1335                         set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1336                                 &drive->atapi_flags);
1337                 return 0;
1338         case MTSEEK:
1339                 ide_tape_discard_merge_buffer(drive, 0);
1340                 return idetape_position_tape(drive,
1341                         mt_count * tape->user_bs_factor, tape->partition, 0);
1342         case MTSETPART:
1343                 ide_tape_discard_merge_buffer(drive, 0);
1344                 return idetape_position_tape(drive, 0, mt_count, 0);
1345         case MTFSR:
1346         case MTBSR:
1347         case MTLOCK:
1348                 retval = ide_set_media_lock(drive, disk, 1);
1349                 if (retval)
1350                         return retval;
1351                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1352                 return 0;
1353         case MTUNLOCK:
1354                 retval = ide_set_media_lock(drive, disk, 0);
1355                 if (retval)
1356                         return retval;
1357                 tape->door_locked = DOOR_UNLOCKED;
1358                 return 0;
1359         default:
1360                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1361                                 mt_op);
1362                 return -EIO;
1363         }
1364 }
1365
1366 /*
1367  * Our character device ioctls. General mtio.h magnetic io commands are
1368  * supported here, and not in the corresponding block interface. Our own
1369  * ide-tape ioctls are supported on both interfaces.
1370  */
1371 static long do_idetape_chrdev_ioctl(struct file *file,
1372                                 unsigned int cmd, unsigned long arg)
1373 {
1374         struct ide_tape_obj *tape = file->private_data;
1375         ide_drive_t *drive = tape->drive;
1376         struct mtop mtop;
1377         struct mtget mtget;
1378         struct mtpos mtpos;
1379         int block_offset = 0, position = tape->first_frame;
1380         void __user *argp = (void __user *)arg;
1381
1382         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x", cmd);
1383
1384         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1385                 ide_tape_flush_merge_buffer(drive);
1386                 idetape_flush_tape_buffers(drive);
1387         }
1388         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1389                 block_offset = tape->valid /
1390                         (tape->blk_size * tape->user_bs_factor);
1391                 position = ide_tape_read_position(drive);
1392                 if (position < 0)
1393                         return -EIO;
1394         }
1395         switch (cmd) {
1396         case MTIOCTOP:
1397                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1398                         return -EFAULT;
1399                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1400         case MTIOCGET:
1401                 memset(&mtget, 0, sizeof(struct mtget));
1402                 mtget.mt_type = MT_ISSCSI2;
1403                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1404                 mtget.mt_dsreg =
1405                         ((tape->blk_size * tape->user_bs_factor)
1406                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1407
1408                 if (tape->drv_write_prot)
1409                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1410
1411                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1412                         return -EFAULT;
1413                 return 0;
1414         case MTIOCPOS:
1415                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1416                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1417                         return -EFAULT;
1418                 return 0;
1419         default:
1420                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1421                         ide_tape_discard_merge_buffer(drive, 1);
1422                 return idetape_blkdev_ioctl(drive, cmd, arg);
1423         }
1424 }
1425
1426 static long idetape_chrdev_ioctl(struct file *file,
1427                                 unsigned int cmd, unsigned long arg)
1428 {
1429         long ret;
1430         mutex_lock(&ide_tape_mutex);
1431         ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1432         mutex_unlock(&ide_tape_mutex);
1433         return ret;
1434 }
1435
1436 /*
1437  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1438  * block size with the reported value.
1439  */
1440 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1441 {
1442         idetape_tape_t *tape = drive->driver_data;
1443         struct ide_atapi_pc pc;
1444         u8 buf[12];
1445
1446         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1447         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1448                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1449                 if (tape->blk_size == 0) {
1450                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1451                                             "block size, assuming 32k\n");
1452                         tape->blk_size = 32768;
1453                 }
1454                 return;
1455         }
1456         tape->blk_size = (buf[4 + 5] << 16) +
1457                                 (buf[4 + 6] << 8)  +
1458                                  buf[4 + 7];
1459         tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1460
1461         ide_debug_log(IDE_DBG_FUNC, "blk_size: %d, write_prot: %d",
1462                       tape->blk_size, tape->drv_write_prot);
1463 }
1464
1465 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1466 {
1467         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1468         ide_drive_t *drive;
1469         idetape_tape_t *tape;
1470         int retval;
1471
1472         if (i >= MAX_HWIFS * MAX_DRIVES)
1473                 return -ENXIO;
1474
1475         mutex_lock(&idetape_chrdev_mutex);
1476
1477         tape = ide_tape_get(NULL, true, i);
1478         if (!tape) {
1479                 mutex_unlock(&idetape_chrdev_mutex);
1480                 return -ENXIO;
1481         }
1482
1483         drive = tape->drive;
1484         filp->private_data = tape;
1485
1486         ide_debug_log(IDE_DBG_FUNC, "enter");
1487
1488         /*
1489          * We really want to do nonseekable_open(inode, filp); here, but some
1490          * versions of tar incorrectly call lseek on tapes and bail out if that
1491          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1492          */
1493         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1494
1495
1496         if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1497                 retval = -EBUSY;
1498                 goto out_put_tape;
1499         }
1500
1501         retval = idetape_wait_ready(drive, 60 * HZ);
1502         if (retval) {
1503                 clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1504                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1505                 goto out_put_tape;
1506         }
1507
1508         ide_tape_read_position(drive);
1509         if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1510                 (void)idetape_rewind_tape(drive);
1511
1512         /* Read block size and write protect status from drive. */
1513         ide_tape_get_bsize_from_bdesc(drive);
1514
1515         /* Set write protect flag if device is opened as read-only. */
1516         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1517                 tape->write_prot = 1;
1518         else
1519                 tape->write_prot = tape->drv_write_prot;
1520
1521         /* Make sure drive isn't write protected if user wants to write. */
1522         if (tape->write_prot) {
1523                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1524                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1525                         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1526                         retval = -EROFS;
1527                         goto out_put_tape;
1528                 }
1529         }
1530
1531         /* Lock the tape drive door so user can't eject. */
1532         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1533                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1534                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1535                                 tape->door_locked = DOOR_LOCKED;
1536                 }
1537         }
1538         mutex_unlock(&idetape_chrdev_mutex);
1539
1540         return 0;
1541
1542 out_put_tape:
1543         ide_tape_put(tape);
1544
1545         mutex_unlock(&idetape_chrdev_mutex);
1546
1547         return retval;
1548 }
1549
1550 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1551 {
1552         idetape_tape_t *tape = drive->driver_data;
1553
1554         ide_tape_flush_merge_buffer(drive);
1555         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1556         if (tape->buf != NULL) {
1557                 idetape_pad_zeros(drive, tape->blk_size *
1558                                 (tape->user_bs_factor - 1));
1559                 kfree(tape->buf);
1560                 tape->buf = NULL;
1561         }
1562         idetape_write_filemark(drive);
1563         idetape_flush_tape_buffers(drive);
1564         idetape_flush_tape_buffers(drive);
1565 }
1566
1567 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1568 {
1569         struct ide_tape_obj *tape = filp->private_data;
1570         ide_drive_t *drive = tape->drive;
1571         unsigned int minor = iminor(inode);
1572
1573         mutex_lock(&idetape_chrdev_mutex);
1574
1575         tape = drive->driver_data;
1576
1577         ide_debug_log(IDE_DBG_FUNC, "enter");
1578
1579         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1580                 idetape_write_release(drive, minor);
1581         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1582                 if (minor < 128)
1583                         ide_tape_discard_merge_buffer(drive, 1);
1584         }
1585
1586         if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1587                                     &drive->atapi_flags))
1588                 (void) idetape_rewind_tape(drive);
1589
1590         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1591                 if (tape->door_locked == DOOR_LOCKED) {
1592                         if (!ide_set_media_lock(drive, tape->disk, 0))
1593                                 tape->door_locked = DOOR_UNLOCKED;
1594                 }
1595         }
1596         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1597         ide_tape_put(tape);
1598
1599         mutex_unlock(&idetape_chrdev_mutex);
1600
1601         return 0;
1602 }
1603
1604 static void idetape_get_inquiry_results(ide_drive_t *drive)
1605 {
1606         idetape_tape_t *tape = drive->driver_data;
1607         struct ide_atapi_pc pc;
1608         u8 pc_buf[256];
1609         char fw_rev[4], vendor_id[8], product_id[16];
1610
1611         idetape_create_inquiry_cmd(&pc);
1612         if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1613                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1614                                 tape->name);
1615                 return;
1616         }
1617         memcpy(vendor_id, &pc_buf[8], 8);
1618         memcpy(product_id, &pc_buf[16], 16);
1619         memcpy(fw_rev, &pc_buf[32], 4);
1620
1621         ide_fixstring(vendor_id, 8, 0);
1622         ide_fixstring(product_id, 16, 0);
1623         ide_fixstring(fw_rev, 4, 0);
1624
1625         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1626                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1627 }
1628
1629 /*
1630  * Ask the tape about its various parameters. In particular, we will adjust our
1631  * data transfer buffer size to the recommended value as returned by the tape.
1632  */
1633 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1634 {
1635         idetape_tape_t *tape = drive->driver_data;
1636         struct ide_atapi_pc pc;
1637         u8 buf[24], *caps;
1638         u8 speed, max_speed;
1639
1640         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1641         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1642                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1643                                 " some default values\n");
1644                 tape->blk_size = 512;
1645                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1646                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1647                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1648                 return;
1649         }
1650         caps = buf + 4 + buf[3];
1651
1652         /* convert to host order and save for later use */
1653         speed = be16_to_cpup((__be16 *)&caps[14]);
1654         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1655
1656         *(u16 *)&caps[8] = max_speed;
1657         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1658         *(u16 *)&caps[14] = speed;
1659         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1660
1661         if (!speed) {
1662                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1663                                 "(assuming 650KB/sec)\n", drive->name);
1664                 *(u16 *)&caps[14] = 650;
1665         }
1666         if (!max_speed) {
1667                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1668                                 "(assuming 650KB/sec)\n", drive->name);
1669                 *(u16 *)&caps[8] = 650;
1670         }
1671
1672         memcpy(&tape->caps, caps, 20);
1673
1674         /* device lacks locking support according to capabilities page */
1675         if ((caps[6] & 1) == 0)
1676                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1677
1678         if (caps[7] & 0x02)
1679                 tape->blk_size = 512;
1680         else if (caps[7] & 0x04)
1681                 tape->blk_size = 1024;
1682 }
1683
1684 #ifdef CONFIG_IDE_PROC_FS
1685 #define ide_tape_devset_get(name, field) \
1686 static int get_##name(ide_drive_t *drive) \
1687 { \
1688         idetape_tape_t *tape = drive->driver_data; \
1689         return tape->field; \
1690 }
1691
1692 #define ide_tape_devset_set(name, field) \
1693 static int set_##name(ide_drive_t *drive, int arg) \
1694 { \
1695         idetape_tape_t *tape = drive->driver_data; \
1696         tape->field = arg; \
1697         return 0; \
1698 }
1699
1700 #define ide_tape_devset_rw_field(_name, _field) \
1701 ide_tape_devset_get(_name, _field) \
1702 ide_tape_devset_set(_name, _field) \
1703 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1704
1705 #define ide_tape_devset_r_field(_name, _field) \
1706 ide_tape_devset_get(_name, _field) \
1707 IDE_DEVSET(_name, 0, get_##_name, NULL)
1708
1709 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1710 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1711 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1712 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1713
1714 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1715
1716 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1717
1718 ide_tape_devset_r_field(avg_speed, avg_speed);
1719 ide_tape_devset_r_field(speed, caps[14]);
1720 ide_tape_devset_r_field(buffer, caps[16]);
1721 ide_tape_devset_r_field(buffer_size, buffer_size);
1722
1723 static const struct ide_proc_devset idetape_settings[] = {
1724         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1725         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1726         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1727         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1728         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1729         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1730                                         mulf_tdsc, divf_tdsc),
1731         { NULL },
1732 };
1733 #endif
1734
1735 /*
1736  * The function below is called to:
1737  *
1738  * 1. Initialize our various state variables.
1739  * 2. Ask the tape for its capabilities.
1740  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1741  * is chosen based on the recommendation which we received in step 2.
1742  *
1743  * Note that at this point ide.c already assigned us an irq, so that we can
1744  * queue requests here and wait for their completion.
1745  */
1746 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1747 {
1748         unsigned long t;
1749         int speed;
1750         int buffer_size;
1751         u16 *ctl = (u16 *)&tape->caps[12];
1752
1753         ide_debug_log(IDE_DBG_FUNC, "minor: %d", minor);
1754
1755         drive->pc_callback = ide_tape_callback;
1756
1757         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1758
1759         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1760                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1761                                  tape->name);
1762                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1763         }
1764
1765         /* Seagate Travan drives do not support DSC overlap. */
1766         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1767                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1768
1769         tape->minor = minor;
1770         tape->name[0] = 'h';
1771         tape->name[1] = 't';
1772         tape->name[2] = '0' + minor;
1773         tape->chrdev_dir = IDETAPE_DIR_NONE;
1774
1775         idetape_get_inquiry_results(drive);
1776         idetape_get_mode_sense_results(drive);
1777         ide_tape_get_bsize_from_bdesc(drive);
1778         tape->user_bs_factor = 1;
1779         tape->buffer_size = *ctl * tape->blk_size;
1780         while (tape->buffer_size > 0xffff) {
1781                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1782                 *ctl /= 2;
1783                 tape->buffer_size = *ctl * tape->blk_size;
1784         }
1785         buffer_size = tape->buffer_size;
1786
1787         /* select the "best" DSC read/write polling freq */
1788         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1789
1790         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1791
1792         /*
1793          * Ensure that the number we got makes sense; limit it within
1794          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1795          */
1796         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1797                                          IDETAPE_DSC_RW_MAX);
1798         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1799                 "%ums tDSC%s\n",
1800                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1801                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1802                 tape->buffer_size / 1024,
1803                 jiffies_to_msecs(tape->best_dsc_rw_freq),
1804                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1805
1806         ide_proc_register_driver(drive, tape->driver);
1807 }
1808
1809 static void ide_tape_remove(ide_drive_t *drive)
1810 {
1811         idetape_tape_t *tape = drive->driver_data;
1812
1813         ide_proc_unregister_driver(drive, tape->driver);
1814         device_del(&tape->dev);
1815         ide_unregister_region(tape->disk);
1816
1817         mutex_lock(&idetape_ref_mutex);
1818         put_device(&tape->dev);
1819         mutex_unlock(&idetape_ref_mutex);
1820 }
1821
1822 static void ide_tape_release(struct device *dev)
1823 {
1824         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1825         ide_drive_t *drive = tape->drive;
1826         struct gendisk *g = tape->disk;
1827
1828         BUG_ON(tape->valid);
1829
1830         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1831         drive->driver_data = NULL;
1832         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1833         device_destroy(idetape_sysfs_class,
1834                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1835         idetape_devs[tape->minor] = NULL;
1836         g->private_data = NULL;
1837         put_disk(g);
1838         kfree(tape);
1839 }
1840
1841 #ifdef CONFIG_IDE_PROC_FS
1842 static int idetape_name_proc_show(struct seq_file *m, void *v)
1843 {
1844         ide_drive_t     *drive = (ide_drive_t *) m->private;
1845         idetape_tape_t  *tape = drive->driver_data;
1846
1847         seq_printf(m, "%s\n", tape->name);
1848         return 0;
1849 }
1850
1851 static int idetape_name_proc_open(struct inode *inode, struct file *file)
1852 {
1853         return single_open(file, idetape_name_proc_show, PDE_DATA(inode));
1854 }
1855
1856 static const struct file_operations idetape_name_proc_fops = {
1857         .owner          = THIS_MODULE,
1858         .open           = idetape_name_proc_open,
1859         .read           = seq_read,
1860         .llseek         = seq_lseek,
1861         .release        = single_release,
1862 };
1863
1864 static ide_proc_entry_t idetape_proc[] = {
1865         { "capacity",   S_IFREG|S_IRUGO,        &ide_capacity_proc_fops },
1866         { "name",       S_IFREG|S_IRUGO,        &idetape_name_proc_fops },
1867         {}
1868 };
1869
1870 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1871 {
1872         return idetape_proc;
1873 }
1874
1875 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1876 {
1877         return idetape_settings;
1878 }
1879 #endif
1880
1881 static int ide_tape_probe(ide_drive_t *);
1882
1883 static struct ide_driver idetape_driver = {
1884         .gen_driver = {
1885                 .owner          = THIS_MODULE,
1886                 .name           = "ide-tape",
1887                 .bus            = &ide_bus_type,
1888         },
1889         .probe                  = ide_tape_probe,
1890         .remove                 = ide_tape_remove,
1891         .version                = IDETAPE_VERSION,
1892         .do_request             = idetape_do_request,
1893 #ifdef CONFIG_IDE_PROC_FS
1894         .proc_entries           = ide_tape_proc_entries,
1895         .proc_devsets           = ide_tape_proc_devsets,
1896 #endif
1897 };
1898
1899 /* Our character device supporting functions, passed to register_chrdev. */
1900 static const struct file_operations idetape_fops = {
1901         .owner          = THIS_MODULE,
1902         .read           = idetape_chrdev_read,
1903         .write          = idetape_chrdev_write,
1904         .unlocked_ioctl = idetape_chrdev_ioctl,
1905         .open           = idetape_chrdev_open,
1906         .release        = idetape_chrdev_release,
1907         .llseek         = noop_llseek,
1908 };
1909
1910 static int idetape_open(struct block_device *bdev, fmode_t mode)
1911 {
1912         struct ide_tape_obj *tape;
1913
1914         mutex_lock(&ide_tape_mutex);
1915         tape = ide_tape_get(bdev->bd_disk, false, 0);
1916         mutex_unlock(&ide_tape_mutex);
1917
1918         if (!tape)
1919                 return -ENXIO;
1920
1921         return 0;
1922 }
1923
1924 static void idetape_release(struct gendisk *disk, fmode_t mode)
1925 {
1926         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1927
1928         mutex_lock(&ide_tape_mutex);
1929         ide_tape_put(tape);
1930         mutex_unlock(&ide_tape_mutex);
1931 }
1932
1933 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1934                         unsigned int cmd, unsigned long arg)
1935 {
1936         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1937         ide_drive_t *drive = tape->drive;
1938         int err;
1939
1940         mutex_lock(&ide_tape_mutex);
1941         err = generic_ide_ioctl(drive, bdev, cmd, arg);
1942         if (err == -EINVAL)
1943                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1944         mutex_unlock(&ide_tape_mutex);
1945
1946         return err;
1947 }
1948
1949 static const struct block_device_operations idetape_block_ops = {
1950         .owner          = THIS_MODULE,
1951         .open           = idetape_open,
1952         .release        = idetape_release,
1953         .ioctl          = idetape_ioctl,
1954 };
1955
1956 static int ide_tape_probe(ide_drive_t *drive)
1957 {
1958         idetape_tape_t *tape;
1959         struct gendisk *g;
1960         int minor;
1961
1962         ide_debug_log(IDE_DBG_FUNC, "enter");
1963
1964         if (!strstr(DRV_NAME, drive->driver_req))
1965                 goto failed;
1966
1967         if (drive->media != ide_tape)
1968                 goto failed;
1969
1970         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1971             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1972                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1973                                 " the driver\n", drive->name);
1974                 goto failed;
1975         }
1976         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1977         if (tape == NULL) {
1978                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1979                                 drive->name);
1980                 goto failed;
1981         }
1982
1983         g = alloc_disk(1 << PARTN_BITS);
1984         if (!g)
1985                 goto out_free_tape;
1986
1987         ide_init_disk(g, drive);
1988
1989         tape->dev.parent = &drive->gendev;
1990         tape->dev.release = ide_tape_release;
1991         dev_set_name(&tape->dev, "%s", dev_name(&drive->gendev));
1992
1993         if (device_register(&tape->dev))
1994                 goto out_free_disk;
1995
1996         tape->drive = drive;
1997         tape->driver = &idetape_driver;
1998         tape->disk = g;
1999
2000         g->private_data = &tape->driver;
2001
2002         drive->driver_data = tape;
2003
2004         mutex_lock(&idetape_ref_mutex);
2005         for (minor = 0; idetape_devs[minor]; minor++)
2006                 ;
2007         idetape_devs[minor] = tape;
2008         mutex_unlock(&idetape_ref_mutex);
2009
2010         idetape_setup(drive, tape, minor);
2011
2012         device_create(idetape_sysfs_class, &drive->gendev,
2013                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2014         device_create(idetape_sysfs_class, &drive->gendev,
2015                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2016                       "n%s", tape->name);
2017
2018         g->fops = &idetape_block_ops;
2019         ide_register_region(g);
2020
2021         return 0;
2022
2023 out_free_disk:
2024         put_disk(g);
2025 out_free_tape:
2026         kfree(tape);
2027 failed:
2028         return -ENODEV;
2029 }
2030
2031 static void __exit idetape_exit(void)
2032 {
2033         driver_unregister(&idetape_driver.gen_driver);
2034         class_destroy(idetape_sysfs_class);
2035         unregister_chrdev(IDETAPE_MAJOR, "ht");
2036 }
2037
2038 static int __init idetape_init(void)
2039 {
2040         int error = 1;
2041         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2042         if (IS_ERR(idetape_sysfs_class)) {
2043                 idetape_sysfs_class = NULL;
2044                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2045                 error = -EBUSY;
2046                 goto out;
2047         }
2048
2049         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2050                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2051                                 " interface\n");
2052                 error = -EBUSY;
2053                 goto out_free_class;
2054         }
2055
2056         error = driver_register(&idetape_driver.gen_driver);
2057         if (error)
2058                 goto out_free_chrdev;
2059
2060         return 0;
2061
2062 out_free_chrdev:
2063         unregister_chrdev(IDETAPE_MAJOR, "ht");
2064 out_free_class:
2065         class_destroy(idetape_sysfs_class);
2066 out:
2067         return error;
2068 }
2069
2070 MODULE_ALIAS("ide:*m-tape*");
2071 module_init(idetape_init);
2072 module_exit(idetape_exit);
2073 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2074 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2075 MODULE_LICENSE("GPL");