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 *)ide_req(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, 0);
 858         ide_req(rq)->type = ATA_PRIV_MISC;
 859         scsi_req(rq)->cmd[13] = cmd;
 860         rq->rq_disk = tape->disk;
 861         rq->__sector = tape->first_frame;
 862
 863         if (size) {
 864                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 865                                       GFP_NOIO);
 866                 if (ret)
 867                         goto out_put;
 868         }
 869
 870         blk_execute_rq(drive->queue, tape->disk, rq, 0);
 871
 872         /* calculate the number of transferred bytes and update buffer state */
 873         size -= scsi_req(rq)->resid_len;
 874         tape->cur = tape->buf;
 875         if (cmd == REQ_IDETAPE_READ)
 876                 tape->valid = size;
 877         else
 878                 tape->valid = 0;
 879
 880         ret = size;
 881         if (scsi_req(rq)->result == IDE_DRV_ERROR_GENERAL)
 882                 ret = -EIO;
 883 out_put:
 884         blk_put_request(rq);
 885         return ret;
 886 }
 887
 888 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 889 {
 890         ide_init_pc(pc);
 891         pc->c[0] = INQUIRY;
 892         pc->c[4] = 254;
 893         pc->req_xfer = 254;
 894 }
 895
 896 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 897                 struct ide_atapi_pc *pc)
 898 {
 899         ide_init_pc(pc);
 900         pc->c[0] = REZERO_UNIT;
 901         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 902 }
 903
 904 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 905 {
 906         ide_init_pc(pc);
 907         pc->c[0] = ERASE;
 908         pc->c[1] = 1;
 909         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 910 }
 911
 912 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 913 {
 914         ide_init_pc(pc);
 915         pc->c[0] = SPACE;
 916         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 917         pc->c[1] = cmd;
 918         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 919 }
 920
 921 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 922 {
 923         idetape_tape_t *tape = drive->driver_data;
 924
 925         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 926                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 927                                 " but we are not writing.\n");
 928                 return;
 929         }
 930         if (tape->buf) {
 931                 size_t aligned = roundup(tape->valid, tape->blk_size);
 932
 933                 memset(tape->cur, 0, aligned - tape->valid);
 934                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 935                 kfree(tape->buf);
 936                 tape->buf = NULL;
 937         }
 938         tape->chrdev_dir = IDETAPE_DIR_NONE;
 939 }
 940
 941 static int idetape_init_rw(ide_drive_t *drive, int dir)
 942 {
 943         idetape_tape_t *tape = drive->driver_data;
 944         int rc;
 945
 946         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 947
 948         if (tape->chrdev_dir == dir)
 949                 return 0;
 950
 951         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 952                 ide_tape_discard_merge_buffer(drive, 1);
 953         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 954                 ide_tape_flush_merge_buffer(drive);
 955                 idetape_flush_tape_buffers(drive);
 956         }
 957
 958         if (tape->buf || tape->valid) {
 959                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 960                 tape->valid = 0;
 961         }
 962
 963         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 964         if (!tape->buf)
 965                 return -ENOMEM;
 966         tape->chrdev_dir = dir;
 967         tape->cur = tape->buf;
 968
 969         /*
 970          * Issue a 0 rw command to ensure that DSC handshake is
 971          * switched from completion mode to buffer available mode.  No
 972          * point in issuing this if DSC overlap isn't supported, some
 973          * drives (Seagate STT3401A) will return an error.
 974          */
 975         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
 976                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
 977                                                   : REQ_IDETAPE_WRITE;
 978
 979                 rc = idetape_queue_rw_tail(drive, cmd, 0);
 980                 if (rc < 0) {
 981                         kfree(tape->buf);
 982                         tape->buf = NULL;
 983                         tape->chrdev_dir = IDETAPE_DIR_NONE;
 984                         return rc;
 985                 }
 986         }
 987
 988         return 0;
 989 }
 990
 991 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
 992 {
 993         idetape_tape_t *tape = drive->driver_data;
 994
 995         memset(tape->buf, 0, tape->buffer_size);
 996
 997         while (bcount) {
 998                 unsigned int count = min(tape->buffer_size, bcount);
 999
1000                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1001                 bcount -= count;
1002         }
1003 }
1004
1005 /*
1006  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1007  * currently support only one partition.
1008  */
1009 static int idetape_rewind_tape(ide_drive_t *drive)
1010 {
1011         struct ide_tape_obj *tape = drive->driver_data;
1012         struct gendisk *disk = tape->disk;
1013         struct ide_atapi_pc pc;
1014         int ret;
1015
1016         ide_debug_log(IDE_DBG_FUNC, "enter");
1017
1018         idetape_create_rewind_cmd(drive, &pc);
1019         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1020         if (ret)
1021                 return ret;
1022
1023         ret = ide_tape_read_position(drive);
1024         if (ret < 0)
1025                 return ret;
1026         return 0;
1027 }
1028
1029 /* mtio.h compatible commands should be issued to the chrdev interface. */
1030 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1031                                 unsigned long arg)
1032 {
1033         idetape_tape_t *tape = drive->driver_data;
1034         void __user *argp = (void __user *)arg;
1035
1036         struct idetape_config {
1037                 int dsc_rw_frequency;
1038                 int dsc_media_access_frequency;
1039                 int nr_stages;
1040         } config;
1041
1042         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%04x", cmd);
1043
1044         switch (cmd) {
1045         case 0x0340:
1046                 if (copy_from_user(&config, argp, sizeof(config)))
1047                         return -EFAULT;
1048                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1049                 break;
1050         case 0x0350:
1051                 memset(&config, 0, sizeof(config));
1052                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1053                 config.nr_stages = 1;
1054                 if (copy_to_user(argp, &config, sizeof(config)))
1055                         return -EFAULT;
1056                 break;
1057         default:
1058                 return -EIO;
1059         }
1060         return 0;
1061 }
1062
1063 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1064                                         int mt_count)
1065 {
1066         idetape_tape_t *tape = drive->driver_data;
1067         struct gendisk *disk = tape->disk;
1068         struct ide_atapi_pc pc;
1069         int retval, count = 0;
1070         int sprev = !!(tape->caps[4] & 0x20);
1071
1072
1073         ide_debug_log(IDE_DBG_FUNC, "mt_op: %d, mt_count: %d", mt_op, mt_count);
1074
1075         if (mt_count == 0)
1076                 return 0;
1077         if (MTBSF == mt_op || MTBSFM == mt_op) {
1078                 if (!sprev)
1079                         return -EIO;
1080                 mt_count = -mt_count;
1081         }
1082
1083         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1084                 tape->valid = 0;
1085                 if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1086                                        &drive->atapi_flags))
1087                         ++count;
1088                 ide_tape_discard_merge_buffer(drive, 0);
1089         }
1090
1091         switch (mt_op) {
1092         case MTFSF:
1093         case MTBSF:
1094                 idetape_create_space_cmd(&pc, mt_count - count,
1095                                          IDETAPE_SPACE_OVER_FILEMARK);
1096                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1097         case MTFSFM:
1098         case MTBSFM:
1099                 if (!sprev)
1100                         return -EIO;
1101                 retval = idetape_space_over_filemarks(drive, MTFSF,
1102                                                       mt_count - count);
1103                 if (retval)
1104                         return retval;
1105                 count = (MTBSFM == mt_op ? 1 : -1);
1106                 return idetape_space_over_filemarks(drive, MTFSF, count);
1107         default:
1108                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1109                                 mt_op);
1110                 return -EIO;
1111         }
1112 }
1113
1114 /*
1115  * Our character device read / write functions.
1116  *
1117  * The tape is optimized to maximize throughput when it is transferring an
1118  * integral number of the "continuous transfer limit", which is a parameter of
1119  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1120  *
1121  * As of version 1.3 of the driver, the character device provides an abstract
1122  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1123  * same backup/restore procedure is supported. The driver will internally
1124  * convert the requests to the recommended transfer unit, so that an unmatch
1125  * between the user's block size to the recommended size will only result in a
1126  * (slightly) increased driver overhead, but will no longer hit performance.
1127  * This is not applicable to Onstream.
1128  */
1129 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1130                                    size_t count, loff_t *ppos)
1131 {
1132         struct ide_tape_obj *tape = file->private_data;
1133         ide_drive_t *drive = tape->drive;
1134         size_t done = 0;
1135         ssize_t ret = 0;
1136         int rc;
1137
1138         ide_debug_log(IDE_DBG_FUNC, "count %zd", count);
1139
1140         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1141                 if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1142                         if (count > tape->blk_size &&
1143                             (count % tape->blk_size) == 0)
1144                                 tape->user_bs_factor = count / tape->blk_size;
1145         }
1146
1147         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1148         if (rc < 0)
1149                 return rc;
1150
1151         while (done < count) {
1152                 size_t todo;
1153
1154                 /* refill if staging buffer is empty */
1155                 if (!tape->valid) {
1156                         /* If we are at a filemark, nothing more to read */
1157                         if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1158                                      &drive->atapi_flags))
1159                                 break;
1160                         /* read */
1161                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1162                                                   tape->buffer_size) <= 0)
1163                                 break;
1164                 }
1165
1166                 /* copy out */
1167                 todo = min_t(size_t, count - done, tape->valid);
1168                 if (copy_to_user(buf + done, tape->cur, todo))
1169                         ret = -EFAULT;
1170
1171                 tape->cur += todo;
1172                 tape->valid -= todo;
1173                 done += todo;
1174         }
1175
1176         if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1177                 idetape_space_over_filemarks(drive, MTFSF, 1);
1178                 return 0;
1179         }
1180
1181         return ret ? ret : done;
1182 }
1183
1184 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1185                                      size_t count, loff_t *ppos)
1186 {
1187         struct ide_tape_obj *tape = file->private_data;
1188         ide_drive_t *drive = tape->drive;
1189         size_t done = 0;
1190         ssize_t ret = 0;
1191         int rc;
1192
1193         /* The drive is write protected. */
1194         if (tape->write_prot)
1195                 return -EACCES;
1196
1197         ide_debug_log(IDE_DBG_FUNC, "count %zd", count);
1198
1199         /* Initialize write operation */
1200         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1201         if (rc < 0)
1202                 return rc;
1203
1204         while (done < count) {
1205                 size_t todo;
1206
1207                 /* flush if staging buffer is full */
1208                 if (tape->valid == tape->buffer_size &&
1209                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1210                                           tape->buffer_size) <= 0)
1211                         return rc;
1212
1213                 /* copy in */
1214                 todo = min_t(size_t, count - done,
1215                              tape->buffer_size - tape->valid);
1216                 if (copy_from_user(tape->cur, buf + done, todo))
1217                         ret = -EFAULT;
1218
1219                 tape->cur += todo;
1220                 tape->valid += todo;
1221                 done += todo;
1222         }
1223
1224         return ret ? ret : done;
1225 }
1226
1227 static int idetape_write_filemark(ide_drive_t *drive)
1228 {
1229         struct ide_tape_obj *tape = drive->driver_data;
1230         struct ide_atapi_pc pc;
1231
1232         /* Write a filemark */
1233         idetape_create_write_filemark_cmd(drive, &pc, 1);
1234         if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1235                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1236                 return -EIO;
1237         }
1238         return 0;
1239 }
1240
1241 /*
1242  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1243  * requested.
1244  *
1245  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1246  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1247  * usually not supported.
1248  *
1249  * The following commands are currently not supported:
1250  *
1251  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1252  * MT_ST_WRITE_THRESHOLD.
1253  */
1254 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1255 {
1256         idetape_tape_t *tape = drive->driver_data;
1257         struct gendisk *disk = tape->disk;
1258         struct ide_atapi_pc pc;
1259         int i, retval;
1260
1261         ide_debug_log(IDE_DBG_FUNC, "MTIOCTOP ioctl: mt_op: %d, mt_count: %d",
1262                       mt_op, mt_count);
1263
1264         switch (mt_op) {
1265         case MTFSF:
1266         case MTFSFM:
1267         case MTBSF:
1268         case MTBSFM:
1269                 if (!mt_count)
1270                         return 0;
1271                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1272         default:
1273                 break;
1274         }
1275
1276         switch (mt_op) {
1277         case MTWEOF:
1278                 if (tape->write_prot)
1279                         return -EACCES;
1280                 ide_tape_discard_merge_buffer(drive, 1);
1281                 for (i = 0; i < mt_count; i++) {
1282                         retval = idetape_write_filemark(drive);
1283                         if (retval)
1284                                 return retval;
1285                 }
1286                 return 0;
1287         case MTREW:
1288                 ide_tape_discard_merge_buffer(drive, 0);
1289                 if (idetape_rewind_tape(drive))
1290                         return -EIO;
1291                 return 0;
1292         case MTLOAD:
1293                 ide_tape_discard_merge_buffer(drive, 0);
1294                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1295         case MTUNLOAD:
1296         case MTOFFL:
1297                 /*
1298                  * If door is locked, attempt to unlock before
1299                  * attempting to eject.
1300                  */
1301                 if (tape->door_locked) {
1302                         if (!ide_set_media_lock(drive, disk, 0))
1303                                 tape->door_locked = DOOR_UNLOCKED;
1304                 }
1305                 ide_tape_discard_merge_buffer(drive, 0);
1306                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1307                 if (!retval)
1308                         clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1309                                   &drive->atapi_flags);
1310                 return retval;
1311         case MTNOP:
1312                 ide_tape_discard_merge_buffer(drive, 0);
1313                 return idetape_flush_tape_buffers(drive);
1314         case MTRETEN:
1315                 ide_tape_discard_merge_buffer(drive, 0);
1316                 return ide_do_start_stop(drive, disk,
1317                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1318         case MTEOM:
1319                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1320                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1321         case MTERASE:
1322                 (void)idetape_rewind_tape(drive);
1323                 idetape_create_erase_cmd(&pc);
1324                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1325         case MTSETBLK:
1326                 if (mt_count) {
1327                         if (mt_count < tape->blk_size ||
1328                             mt_count % tape->blk_size)
1329                                 return -EIO;
1330                         tape->user_bs_factor = mt_count / tape->blk_size;
1331                         clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1332                                   &drive->atapi_flags);
1333                 } else
1334                         set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1335                                 &drive->atapi_flags);
1336                 return 0;
1337         case MTSEEK:
1338                 ide_tape_discard_merge_buffer(drive, 0);
1339                 return idetape_position_tape(drive,
1340                         mt_count * tape->user_bs_factor, tape->partition, 0);
1341         case MTSETPART:
1342                 ide_tape_discard_merge_buffer(drive, 0);
1343                 return idetape_position_tape(drive, 0, mt_count, 0);
1344         case MTFSR:
1345         case MTBSR:
1346         case MTLOCK:
1347                 retval = ide_set_media_lock(drive, disk, 1);
1348                 if (retval)
1349                         return retval;
1350                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1351                 return 0;
1352         case MTUNLOCK:
1353                 retval = ide_set_media_lock(drive, disk, 0);
1354                 if (retval)
1355                         return retval;
1356                 tape->door_locked = DOOR_UNLOCKED;
1357                 return 0;
1358         default:
1359                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1360                                 mt_op);
1361                 return -EIO;
1362         }
1363 }
1364
1365 /*
1366  * Our character device ioctls. General mtio.h magnetic io commands are
1367  * supported here, and not in the corresponding block interface. Our own
1368  * ide-tape ioctls are supported on both interfaces.
1369  */
1370 static long do_idetape_chrdev_ioctl(struct file *file,
1371                                 unsigned int cmd, unsigned long arg)
1372 {
1373         struct ide_tape_obj *tape = file->private_data;
1374         ide_drive_t *drive = tape->drive;
1375         struct mtop mtop;
1376         struct mtget mtget;
1377         struct mtpos mtpos;
1378         int block_offset = 0, position = tape->first_frame;
1379         void __user *argp = (void __user *)arg;
1380
1381         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x", cmd);
1382
1383         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1384                 ide_tape_flush_merge_buffer(drive);
1385                 idetape_flush_tape_buffers(drive);
1386         }
1387         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1388                 block_offset = tape->valid /
1389                         (tape->blk_size * tape->user_bs_factor);
1390                 position = ide_tape_read_position(drive);
1391                 if (position < 0)
1392                         return -EIO;
1393         }
1394         switch (cmd) {
1395         case MTIOCTOP:
1396                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1397                         return -EFAULT;
1398                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1399         case MTIOCGET:
1400                 memset(&mtget, 0, sizeof(struct mtget));
1401                 mtget.mt_type = MT_ISSCSI2;
1402                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1403                 mtget.mt_dsreg =
1404                         ((tape->blk_size * tape->user_bs_factor)
1405                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1406
1407                 if (tape->drv_write_prot)
1408                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1409
1410                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1411                         return -EFAULT;
1412                 return 0;
1413         case MTIOCPOS:
1414                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1415                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1416                         return -EFAULT;
1417                 return 0;
1418         default:
1419                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1420                         ide_tape_discard_merge_buffer(drive, 1);
1421                 return idetape_blkdev_ioctl(drive, cmd, arg);
1422         }
1423 }
1424
1425 static long idetape_chrdev_ioctl(struct file *file,
1426                                 unsigned int cmd, unsigned long arg)
1427 {
1428         long ret;
1429         mutex_lock(&ide_tape_mutex);
1430         ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1431         mutex_unlock(&ide_tape_mutex);
1432         return ret;
1433 }
1434
1435 /*
1436  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1437  * block size with the reported value.
1438  */
1439 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1440 {
1441         idetape_tape_t *tape = drive->driver_data;
1442         struct ide_atapi_pc pc;
1443         u8 buf[12];
1444
1445         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1446         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1447                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1448                 if (tape->blk_size == 0) {
1449                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1450                                             "block size, assuming 32k\n");
1451                         tape->blk_size = 32768;
1452                 }
1453                 return;
1454         }
1455         tape->blk_size = (buf[4 + 5] << 16) +
1456                                 (buf[4 + 6] << 8)  +
1457                                  buf[4 + 7];
1458         tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1459
1460         ide_debug_log(IDE_DBG_FUNC, "blk_size: %d, write_prot: %d",
1461                       tape->blk_size, tape->drv_write_prot);
1462 }
1463
1464 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1465 {
1466         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1467         ide_drive_t *drive;
1468         idetape_tape_t *tape;
1469         int retval;
1470
1471         if (i >= MAX_HWIFS * MAX_DRIVES)
1472                 return -ENXIO;
1473
1474         mutex_lock(&idetape_chrdev_mutex);
1475
1476         tape = ide_tape_get(NULL, true, i);
1477         if (!tape) {
1478                 mutex_unlock(&idetape_chrdev_mutex);
1479                 return -ENXIO;
1480         }
1481
1482         drive = tape->drive;
1483         filp->private_data = tape;
1484
1485         ide_debug_log(IDE_DBG_FUNC, "enter");
1486
1487         /*
1488          * We really want to do nonseekable_open(inode, filp); here, but some
1489          * versions of tar incorrectly call lseek on tapes and bail out if that
1490          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1491          */
1492         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1493
1494
1495         if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1496                 retval = -EBUSY;
1497                 goto out_put_tape;
1498         }
1499
1500         retval = idetape_wait_ready(drive, 60 * HZ);
1501         if (retval) {
1502                 clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1503                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1504                 goto out_put_tape;
1505         }
1506
1507         ide_tape_read_position(drive);
1508         if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1509                 (void)idetape_rewind_tape(drive);
1510
1511         /* Read block size and write protect status from drive. */
1512         ide_tape_get_bsize_from_bdesc(drive);
1513
1514         /* Set write protect flag if device is opened as read-only. */
1515         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1516                 tape->write_prot = 1;
1517         else
1518                 tape->write_prot = tape->drv_write_prot;
1519
1520         /* Make sure drive isn't write protected if user wants to write. */
1521         if (tape->write_prot) {
1522                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1523                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1524                         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1525                         retval = -EROFS;
1526                         goto out_put_tape;
1527                 }
1528         }
1529
1530         /* Lock the tape drive door so user can't eject. */
1531         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1532                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1533                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1534                                 tape->door_locked = DOOR_LOCKED;
1535                 }
1536         }
1537         mutex_unlock(&idetape_chrdev_mutex);
1538
1539         return 0;
1540
1541 out_put_tape:
1542         ide_tape_put(tape);
1543
1544         mutex_unlock(&idetape_chrdev_mutex);
1545
1546         return retval;
1547 }
1548
1549 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1550 {
1551         idetape_tape_t *tape = drive->driver_data;
1552
1553         ide_tape_flush_merge_buffer(drive);
1554         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1555         if (tape->buf != NULL) {
1556                 idetape_pad_zeros(drive, tape->blk_size *
1557                                 (tape->user_bs_factor - 1));
1558                 kfree(tape->buf);
1559                 tape->buf = NULL;
1560         }
1561         idetape_write_filemark(drive);
1562         idetape_flush_tape_buffers(drive);
1563         idetape_flush_tape_buffers(drive);
1564 }
1565
1566 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1567 {
1568         struct ide_tape_obj *tape = filp->private_data;
1569         ide_drive_t *drive = tape->drive;
1570         unsigned int minor = iminor(inode);
1571
1572         mutex_lock(&idetape_chrdev_mutex);
1573
1574         tape = drive->driver_data;
1575
1576         ide_debug_log(IDE_DBG_FUNC, "enter");
1577
1578         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1579                 idetape_write_release(drive, minor);
1580         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1581                 if (minor < 128)
1582                         ide_tape_discard_merge_buffer(drive, 1);
1583         }
1584
1585         if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1586                                     &drive->atapi_flags))
1587                 (void) idetape_rewind_tape(drive);
1588
1589         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1590                 if (tape->door_locked == DOOR_LOCKED) {
1591                         if (!ide_set_media_lock(drive, tape->disk, 0))
1592                                 tape->door_locked = DOOR_UNLOCKED;
1593                 }
1594         }
1595         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1596         ide_tape_put(tape);
1597
1598         mutex_unlock(&idetape_chrdev_mutex);
1599
1600         return 0;
1601 }
1602
1603 static void idetape_get_inquiry_results(ide_drive_t *drive)
1604 {
1605         idetape_tape_t *tape = drive->driver_data;
1606         struct ide_atapi_pc pc;
1607         u8 pc_buf[256];
1608         char fw_rev[4], vendor_id[8], product_id[16];
1609
1610         idetape_create_inquiry_cmd(&pc);
1611         if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1612                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1613                                 tape->name);
1614                 return;
1615         }
1616         memcpy(vendor_id, &pc_buf[8], 8);
1617         memcpy(product_id, &pc_buf[16], 16);
1618         memcpy(fw_rev, &pc_buf[32], 4);
1619
1620         ide_fixstring(vendor_id, 8, 0);
1621         ide_fixstring(product_id, 16, 0);
1622         ide_fixstring(fw_rev, 4, 0);
1623
1624         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1625                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1626 }
1627
1628 /*
1629  * Ask the tape about its various parameters. In particular, we will adjust our
1630  * data transfer buffer size to the recommended value as returned by the tape.
1631  */
1632 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1633 {
1634         idetape_tape_t *tape = drive->driver_data;
1635         struct ide_atapi_pc pc;
1636         u8 buf[24], *caps;
1637         u8 speed, max_speed;
1638
1639         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1640         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1641                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1642                                 " some default values\n");
1643                 tape->blk_size = 512;
1644                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1645                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1646                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1647                 return;
1648         }
1649         caps = buf + 4 + buf[3];
1650
1651         /* convert to host order and save for later use */
1652         speed = be16_to_cpup((__be16 *)&caps[14]);
1653         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1654
1655         *(u16 *)&caps[8] = max_speed;
1656         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1657         *(u16 *)&caps[14] = speed;
1658         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1659
1660         if (!speed) {
1661                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1662                                 "(assuming 650KB/sec)\n", drive->name);
1663                 *(u16 *)&caps[14] = 650;
1664         }
1665         if (!max_speed) {
1666                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1667                                 "(assuming 650KB/sec)\n", drive->name);
1668                 *(u16 *)&caps[8] = 650;
1669         }
1670
1671         memcpy(&tape->caps, caps, 20);
1672
1673         /* device lacks locking support according to capabilities page */
1674         if ((caps[6] & 1) == 0)
1675                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1676
1677         if (caps[7] & 0x02)
1678                 tape->blk_size = 512;
1679         else if (caps[7] & 0x04)
1680                 tape->blk_size = 1024;
1681 }
1682
1683 #ifdef CONFIG_IDE_PROC_FS
1684 #define ide_tape_devset_get(name, field) \
1685 static int get_##name(ide_drive_t *drive) \
1686 { \
1687         idetape_tape_t *tape = drive->driver_data; \
1688         return tape->field; \
1689 }
1690
1691 #define ide_tape_devset_set(name, field) \
1692 static int set_##name(ide_drive_t *drive, int arg) \
1693 { \
1694         idetape_tape_t *tape = drive->driver_data; \
1695         tape->field = arg; \
1696         return 0; \
1697 }
1698
1699 #define ide_tape_devset_rw_field(_name, _field) \
1700 ide_tape_devset_get(_name, _field) \
1701 ide_tape_devset_set(_name, _field) \
1702 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1703
1704 #define ide_tape_devset_r_field(_name, _field) \
1705 ide_tape_devset_get(_name, _field) \
1706 IDE_DEVSET(_name, 0, get_##_name, NULL)
1707
1708 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1709 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1710 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1711 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1712
1713 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1714
1715 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1716
1717 ide_tape_devset_r_field(avg_speed, avg_speed);
1718 ide_tape_devset_r_field(speed, caps[14]);
1719 ide_tape_devset_r_field(buffer, caps[16]);
1720 ide_tape_devset_r_field(buffer_size, buffer_size);
1721
1722 static const struct ide_proc_devset idetape_settings[] = {
1723         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1724         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1725         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1726         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1727         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1728         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1729                                         mulf_tdsc, divf_tdsc),
1730         { NULL },
1731 };
1732 #endif
1733
1734 /*
1735  * The function below is called to:
1736  *
1737  * 1. Initialize our various state variables.
1738  * 2. Ask the tape for its capabilities.
1739  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1740  * is chosen based on the recommendation which we received in step 2.
1741  *
1742  * Note that at this point ide.c already assigned us an irq, so that we can
1743  * queue requests here and wait for their completion.
1744  */
1745 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1746 {
1747         unsigned long t;
1748         int speed;
1749         u16 *ctl = (u16 *)&tape->caps[12];
1750
1751         ide_debug_log(IDE_DBG_FUNC, "minor: %d", minor);
1752
1753         drive->pc_callback = ide_tape_callback;
1754
1755         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1756
1757         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1758                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1759                                  tape->name);
1760                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1761         }
1762
1763         /* Seagate Travan drives do not support DSC overlap. */
1764         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1765                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1766
1767         tape->minor = minor;
1768         tape->name[0] = 'h';
1769         tape->name[1] = 't';
1770         tape->name[2] = '0' + minor;
1771         tape->chrdev_dir = IDETAPE_DIR_NONE;
1772
1773         idetape_get_inquiry_results(drive);
1774         idetape_get_mode_sense_results(drive);
1775         ide_tape_get_bsize_from_bdesc(drive);
1776         tape->user_bs_factor = 1;
1777         tape->buffer_size = *ctl * tape->blk_size;
1778         while (tape->buffer_size > 0xffff) {
1779                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1780                 *ctl /= 2;
1781                 tape->buffer_size = *ctl * tape->blk_size;
1782         }
1783
1784         /* select the "best" DSC read/write polling freq */
1785         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1786
1787         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1788
1789         /*
1790          * Ensure that the number we got makes sense; limit it within
1791          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1792          */
1793         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1794                                          IDETAPE_DSC_RW_MAX);
1795         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1796                 "%ums tDSC%s\n",
1797                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1798                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1799                 tape->buffer_size / 1024,
1800                 jiffies_to_msecs(tape->best_dsc_rw_freq),
1801                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1802
1803         ide_proc_register_driver(drive, tape->driver);
1804 }
1805
1806 static void ide_tape_remove(ide_drive_t *drive)
1807 {
1808         idetape_tape_t *tape = drive->driver_data;
1809
1810         ide_proc_unregister_driver(drive, tape->driver);
1811         device_del(&tape->dev);
1812         ide_unregister_region(tape->disk);
1813
1814         mutex_lock(&idetape_ref_mutex);
1815         put_device(&tape->dev);
1816         mutex_unlock(&idetape_ref_mutex);
1817 }
1818
1819 static void ide_tape_release(struct device *dev)
1820 {
1821         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1822         ide_drive_t *drive = tape->drive;
1823         struct gendisk *g = tape->disk;
1824
1825         BUG_ON(tape->valid);
1826
1827         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1828         drive->driver_data = NULL;
1829         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1830         device_destroy(idetape_sysfs_class,
1831                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1832         idetape_devs[tape->minor] = NULL;
1833         g->private_data = NULL;
1834         put_disk(g);
1835         kfree(tape);
1836 }
1837
1838 #ifdef CONFIG_IDE_PROC_FS
1839 static int idetape_name_proc_show(struct seq_file *m, void *v)
1840 {
1841         ide_drive_t     *drive = (ide_drive_t *) m->private;
1842         idetape_tape_t  *tape = drive->driver_data;
1843
1844         seq_printf(m, "%s\n", tape->name);
1845         return 0;
1846 }
1847
1848 static ide_proc_entry_t idetape_proc[] = {
1849         { "capacity",   S_IFREG|S_IRUGO,        ide_capacity_proc_show  },
1850         { "name",       S_IFREG|S_IRUGO,        idetape_name_proc_show  },
1851         {}
1852 };
1853
1854 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1855 {
1856         return idetape_proc;
1857 }
1858
1859 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1860 {
1861         return idetape_settings;
1862 }
1863 #endif
1864
1865 static int ide_tape_probe(ide_drive_t *);
1866
1867 static struct ide_driver idetape_driver = {
1868         .gen_driver = {
1869                 .owner          = THIS_MODULE,
1870                 .name           = "ide-tape",
1871                 .bus            = &ide_bus_type,
1872         },
1873         .probe                  = ide_tape_probe,
1874         .remove                 = ide_tape_remove,
1875         .version                = IDETAPE_VERSION,
1876         .do_request             = idetape_do_request,
1877 #ifdef CONFIG_IDE_PROC_FS
1878         .proc_entries           = ide_tape_proc_entries,
1879         .proc_devsets           = ide_tape_proc_devsets,
1880 #endif
1881 };
1882
1883 /* Our character device supporting functions, passed to register_chrdev. */
1884 static const struct file_operations idetape_fops = {
1885         .owner          = THIS_MODULE,
1886         .read           = idetape_chrdev_read,
1887         .write          = idetape_chrdev_write,
1888         .unlocked_ioctl = idetape_chrdev_ioctl,
1889         .open           = idetape_chrdev_open,
1890         .release        = idetape_chrdev_release,
1891         .llseek         = noop_llseek,
1892 };
1893
1894 static int idetape_open(struct block_device *bdev, fmode_t mode)
1895 {
1896         struct ide_tape_obj *tape;
1897
1898         mutex_lock(&ide_tape_mutex);
1899         tape = ide_tape_get(bdev->bd_disk, false, 0);
1900         mutex_unlock(&ide_tape_mutex);
1901
1902         if (!tape)
1903                 return -ENXIO;
1904
1905         return 0;
1906 }
1907
1908 static void idetape_release(struct gendisk *disk, fmode_t mode)
1909 {
1910         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1911
1912         mutex_lock(&ide_tape_mutex);
1913         ide_tape_put(tape);
1914         mutex_unlock(&ide_tape_mutex);
1915 }
1916
1917 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1918                         unsigned int cmd, unsigned long arg)
1919 {
1920         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1921         ide_drive_t *drive = tape->drive;
1922         int err;
1923
1924         mutex_lock(&ide_tape_mutex);
1925         err = generic_ide_ioctl(drive, bdev, cmd, arg);
1926         if (err == -EINVAL)
1927                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1928         mutex_unlock(&ide_tape_mutex);
1929
1930         return err;
1931 }
1932
1933 static const struct block_device_operations idetape_block_ops = {
1934         .owner          = THIS_MODULE,
1935         .open           = idetape_open,
1936         .release        = idetape_release,
1937         .ioctl          = idetape_ioctl,
1938 };
1939
1940 static int ide_tape_probe(ide_drive_t *drive)
1941 {
1942         idetape_tape_t *tape;
1943         struct gendisk *g;
1944         int minor;
1945
1946         ide_debug_log(IDE_DBG_FUNC, "enter");
1947
1948         if (!strstr(DRV_NAME, drive->driver_req))
1949                 goto failed;
1950
1951         if (drive->media != ide_tape)
1952                 goto failed;
1953
1954         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1955             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1956                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1957                                 " the driver\n", drive->name);
1958                 goto failed;
1959         }
1960         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1961         if (tape == NULL) {
1962                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1963                                 drive->name);
1964                 goto failed;
1965         }
1966
1967         g = alloc_disk(1 << PARTN_BITS);
1968         if (!g)
1969                 goto out_free_tape;
1970
1971         ide_init_disk(g, drive);
1972
1973         tape->dev.parent = &drive->gendev;
1974         tape->dev.release = ide_tape_release;
1975         dev_set_name(&tape->dev, "%s", dev_name(&drive->gendev));
1976
1977         if (device_register(&tape->dev))
1978                 goto out_free_disk;
1979
1980         tape->drive = drive;
1981         tape->driver = &idetape_driver;
1982         tape->disk = g;
1983
1984         g->private_data = &tape->driver;
1985
1986         drive->driver_data = tape;
1987
1988         mutex_lock(&idetape_ref_mutex);
1989         for (minor = 0; idetape_devs[minor]; minor++)
1990                 ;
1991         idetape_devs[minor] = tape;
1992         mutex_unlock(&idetape_ref_mutex);
1993
1994         idetape_setup(drive, tape, minor);
1995
1996         device_create(idetape_sysfs_class, &drive->gendev,
1997                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
1998         device_create(idetape_sysfs_class, &drive->gendev,
1999                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2000                       "n%s", tape->name);
2001
2002         g->fops = &idetape_block_ops;
2003         ide_register_region(g);
2004
2005         return 0;
2006
2007 out_free_disk:
2008         put_disk(g);
2009 out_free_tape:
2010         kfree(tape);
2011 failed:
2012         return -ENODEV;
2013 }
2014
2015 static void __exit idetape_exit(void)
2016 {
2017         driver_unregister(&idetape_driver.gen_driver);
2018         class_destroy(idetape_sysfs_class);
2019         unregister_chrdev(IDETAPE_MAJOR, "ht");
2020 }
2021
2022 static int __init idetape_init(void)
2023 {
2024         int error = 1;
2025         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2026         if (IS_ERR(idetape_sysfs_class)) {
2027                 idetape_sysfs_class = NULL;
2028                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2029                 error = -EBUSY;
2030                 goto out;
2031         }
2032
2033         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2034                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2035                                 " interface\n");
2036                 error = -EBUSY;
2037                 goto out_free_class;
2038         }
2039
2040         error = driver_register(&idetape_driver.gen_driver);
2041         if (error)
2042                 goto out_free_chrdev;
2043
2044         return 0;
2045
2046 out_free_chrdev:
2047         unregister_chrdev(IDETAPE_MAJOR, "ht");
2048 out_free_class:
2049         class_destroy(idetape_sysfs_class);
2050 out:
2051         return error;
2052 }
2053
2054 MODULE_ALIAS("ide:*m-tape*");
2055 module_init(idetape_init);
2056 module_exit(idetape_exit);
2057 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2058 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2059 MODULE_LICENSE("GPL");