git.oblomov.eu Git - linux-2.6/blob - drivers/ide/ide-tape.c

   1 /*
   2  * IDE ATAPI streaming tape driver.
   3  *
   4  * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
   5  * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
   6  *
   7  * This driver was constructed as a student project in the software laboratory
   8  * of the faculty of electrical engineering in the Technion - Israel's
   9  * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
  10  *
  11  * It is hereby placed under the terms of the GNU general public license.
  12  * (See linux/COPYING).
  13  *
  14  * For a historical changelog see
  15  * Documentation/ide/ChangeLog.ide-tape.1995-2002
  16  */
  17
  18 #define DRV_NAME "ide-tape"
  19
  20 #define IDETAPE_VERSION "1.20"
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/kernel.h>
  26 #include <linux/delay.h>
  27 #include <linux/timer.h>
  28 #include <linux/mm.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/major.h>
  32 #include <linux/errno.h>
  33 #include <linux/genhd.h>
  34 #include <linux/slab.h>
  35 #include <linux/pci.h>
  36 #include <linux/ide.h>
  37 #include <linux/smp_lock.h>
  38 #include <linux/completion.h>
  39 #include <linux/bitops.h>
  40 #include <linux/mutex.h>
  41 #include <scsi/scsi.h>
  42
  43 #include <asm/byteorder.h>
  44 #include <linux/irq.h>
  45 #include <linux/uaccess.h>
  46 #include <linux/io.h>
  47 #include <asm/unaligned.h>
  48 #include <linux/mtio.h>
  49
  50 enum {
  51         /* output errors only */
  52         DBG_ERR =               (1 << 0),
  53         /* output all sense key/asc */
  54         DBG_SENSE =             (1 << 1),
  55         /* info regarding all chrdev-related procedures */
  56         DBG_CHRDEV =            (1 << 2),
  57         /* all remaining procedures */
  58         DBG_PROCS =             (1 << 3),
  59 };
  60
  61 /* define to see debug info */
  62 #define IDETAPE_DEBUG_LOG               0
  63
  64 #if IDETAPE_DEBUG_LOG
  65 #define debug_log(lvl, fmt, args...)                    \
  66 {                                                       \
  67         if (tape->debug_mask & lvl)                     \
  68         printk(KERN_INFO "ide-tape: " fmt, ## args);    \
  69 }
  70 #else
  71 #define debug_log(lvl, fmt, args...) do {} while (0)
  72 #endif
  73
  74 /**************************** Tunable parameters *****************************/
  75 /*
  76  * After each failed packet command we issue a request sense command and retry
  77  * the packet command IDETAPE_MAX_PC_RETRIES times.
  78  *
  79  * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
  80  */
  81 #define IDETAPE_MAX_PC_RETRIES          3
  82
  83 /*
  84  * The following parameter is used to select the point in the internal tape fifo
  85  * in which we will start to refill the buffer. Decreasing the following
  86  * parameter will improve the system's latency and interactive response, while
  87  * using a high value might improve system throughput.
  88  */
  89 #define IDETAPE_FIFO_THRESHOLD          2
  90
  91 /*
  92  * DSC polling parameters.
  93  *
  94  * Polling for DSC (a single bit in the status register) is a very important
  95  * function in ide-tape. There are two cases in which we poll for DSC:
  96  *
  97  * 1. Before a read/write packet command, to ensure that we can transfer data
  98  * from/to the tape's data buffers, without causing an actual media access.
  99  * In case the tape is not ready yet, we take out our request from the device
 100  * request queue, so that ide.c could service requests from the other device
 101  * on the same interface in the meantime.
 102  *
 103  * 2. After the successful initialization of a "media access packet command",
 104  * which is a command that can take a long time to complete (the interval can
 105  * range from several seconds to even an hour). Again, we postpone our request
 106  * in the middle to free the bus for the other device. The polling frequency
 107  * here should be lower than the read/write frequency since those media access
 108  * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
 109  * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
 110  * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
 111  *
 112  * We also set a timeout for the timer, in case something goes wrong. The
 113  * timeout should be longer then the maximum execution time of a tape operation.
 114  */
 115
 116 /* DSC timings. */
 117 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 118 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 119 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 120 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 121 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 122 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 123 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 124
 125 /*************************** End of tunable parameters ***********************/
 126
 127 /* tape directions */
 128 enum {
 129         IDETAPE_DIR_NONE  = (1 << 0),
 130         IDETAPE_DIR_READ  = (1 << 1),
 131         IDETAPE_DIR_WRITE = (1 << 2),
 132 };
 133
 134 /* Tape door status */
 135 #define DOOR_UNLOCKED                   0
 136 #define DOOR_LOCKED                     1
 137 #define DOOR_EXPLICITLY_LOCKED          2
 138
 139 /* Some defines for the SPACE command */
 140 #define IDETAPE_SPACE_OVER_FILEMARK     1
 141 #define IDETAPE_SPACE_TO_EOD            3
 142
 143 /* Some defines for the LOAD UNLOAD command */
 144 #define IDETAPE_LU_LOAD_MASK            1
 145 #define IDETAPE_LU_RETENSION_MASK       2
 146 #define IDETAPE_LU_EOT_MASK             4
 147
 148 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
 149 #define IDETAPE_BLOCK_DESCRIPTOR        0
 150 #define IDETAPE_CAPABILITIES_PAGE       0x2a
 151
 152 /*
 153  * Most of our global data which we need to save even as we leave the driver due
 154  * to an interrupt or a timer event is stored in the struct defined below.
 155  */
 156 typedef struct ide_tape_obj {
 157         ide_drive_t             *drive;
 158         struct ide_driver       *driver;
 159         struct gendisk          *disk;
 160         struct device           dev;
 161
 162         /* used by REQ_IDETAPE_{READ,WRITE} requests */
 163         struct ide_atapi_pc queued_pc;
 164
 165         /*
 166          * DSC polling variables.
 167          *
 168          * While polling for DSC we use postponed_rq to postpone the current
 169          * request so that ide.c will be able to service pending requests on the
 170          * other device. Note that at most we will have only one DSC (usually
 171          * data transfer) request in the device request queue.
 172          */
 173         struct request *postponed_rq;
 174         /* The time in which we started polling for DSC */
 175         unsigned long dsc_polling_start;
 176         /* Timer used to poll for dsc */
 177         struct timer_list dsc_timer;
 178         /* Read/Write dsc polling frequency */
 179         unsigned long best_dsc_rw_freq;
 180         unsigned long dsc_poll_freq;
 181         unsigned long dsc_timeout;
 182
 183         /* Read position information */
 184         u8 partition;
 185         /* Current block */
 186         unsigned int first_frame;
 187
 188         /* Last error information */
 189         u8 sense_key, asc, ascq;
 190
 191         /* Character device operation */
 192         unsigned int minor;
 193         /* device name */
 194         char name[4];
 195         /* Current character device data transfer direction */
 196         u8 chrdev_dir;
 197
 198         /* tape block size, usually 512 or 1024 bytes */
 199         unsigned short blk_size;
 200         int user_bs_factor;
 201
 202         /* Copy of the tape's Capabilities and Mechanical Page */
 203         u8 caps[20];
 204
 205         /*
 206          * Active data transfer request parameters.
 207          *
 208          * At most, there is only one ide-tape originated data transfer request
 209          * in the device request queue. This allows ide.c to easily service
 210          * requests from the other device when we postpone our active request.
 211          */
 212
 213         /* Data buffer size chosen based on the tape's recommendation */
 214         int buffer_size;
 215         /* Staging buffer of buffer_size bytes */
 216         void *buf;
 217         /* The read/write cursor */
 218         void *cur;
 219         /* The number of valid bytes in buf */
 220         size_t valid;
 221
 222         /* Measures average tape speed */
 223         unsigned long avg_time;
 224         int avg_size;
 225         int avg_speed;
 226
 227         /* the door is currently locked */
 228         int door_locked;
 229         /* the tape hardware is write protected */
 230         char drv_write_prot;
 231         /* the tape is write protected (hardware or opened as read-only) */
 232         char write_prot;
 233
 234         u32 debug_mask;
 235 } idetape_tape_t;
 236
 237 static DEFINE_MUTEX(idetape_ref_mutex);
 238
 239 static struct class *idetape_sysfs_class;
 240
 241 static void ide_tape_release(struct device *);
 242
 243 static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
 244
 245 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk, bool cdev,
 246                                          unsigned int i)
 247 {
 248         struct ide_tape_obj *tape = NULL;
 249
 250         mutex_lock(&idetape_ref_mutex);
 251
 252         if (cdev)
 253                 tape = idetape_devs[i];
 254         else
 255                 tape = ide_drv_g(disk, ide_tape_obj);
 256
 257         if (tape) {
 258                 if (ide_device_get(tape->drive))
 259                         tape = NULL;
 260                 else
 261                         get_device(&tape->dev);
 262         }
 263
 264         mutex_unlock(&idetape_ref_mutex);
 265         return tape;
 266 }
 267
 268 static void ide_tape_put(struct ide_tape_obj *tape)
 269 {
 270         ide_drive_t *drive = tape->drive;
 271
 272         mutex_lock(&idetape_ref_mutex);
 273         put_device(&tape->dev);
 274         ide_device_put(drive);
 275         mutex_unlock(&idetape_ref_mutex);
 276 }
 277
 278 /*
 279  * called on each failed packet command retry to analyze the request sense. We
 280  * currently do not utilize this information.
 281  */
 282 static void idetape_analyze_error(ide_drive_t *drive)
 283 {
 284         idetape_tape_t *tape = drive->driver_data;
 285         struct ide_atapi_pc *pc = drive->failed_pc;
 286         struct request *rq = drive->hwif->rq;
 287         u8 *sense = bio_data(rq->bio);
 288
 289         tape->sense_key = sense[2] & 0xF;
 290         tape->asc       = sense[12];
 291         tape->ascq      = sense[13];
 292
 293         debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
 294                  pc->c[0], tape->sense_key, tape->asc, tape->ascq);
 295
 296         /* correct remaining bytes to transfer */
 297         if (pc->flags & PC_FLAG_DMA_ERROR)
 298                 rq->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
 299
 300         /*
 301          * If error was the result of a zero-length read or write command,
 302          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
 303          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
 304          */
 305         if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
 306             /* length == 0 */
 307             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
 308                 if (tape->sense_key == 5) {
 309                         /* don't report an error, everything's ok */
 310                         pc->error = 0;
 311                         /* don't retry read/write */
 312                         pc->flags |= PC_FLAG_ABORT;
 313                 }
 314         }
 315         if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
 316                 pc->error = IDE_DRV_ERROR_FILEMARK;
 317                 pc->flags |= PC_FLAG_ABORT;
 318         }
 319         if (pc->c[0] == WRITE_6) {
 320                 if ((sense[2] & 0x40) || (tape->sense_key == 0xd
 321                      && tape->asc == 0x0 && tape->ascq == 0x2)) {
 322                         pc->error = IDE_DRV_ERROR_EOD;
 323                         pc->flags |= PC_FLAG_ABORT;
 324                 }
 325         }
 326         if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 327                 if (tape->sense_key == 8) {
 328                         pc->error = IDE_DRV_ERROR_EOD;
 329                         pc->flags |= PC_FLAG_ABORT;
 330                 }
 331                 if (!(pc->flags & PC_FLAG_ABORT) &&
 332                     (blk_rq_bytes(rq) - rq->resid_len))
 333                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
 334         }
 335 }
 336
 337 static void ide_tape_handle_dsc(ide_drive_t *);
 338
 339 static int ide_tape_callback(ide_drive_t *drive, int dsc)
 340 {
 341         idetape_tape_t *tape = drive->driver_data;
 342         struct ide_atapi_pc *pc = drive->pc;
 343         struct request *rq = drive->hwif->rq;
 344         int uptodate = pc->error ? 0 : 1;
 345         int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 346
 347         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 348
 349         if (dsc)
 350                 ide_tape_handle_dsc(drive);
 351
 352         if (drive->failed_pc == pc)
 353                 drive->failed_pc = NULL;
 354
 355         if (pc->c[0] == REQUEST_SENSE) {
 356                 if (uptodate)
 357                         idetape_analyze_error(drive);
 358                 else
 359                         printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
 360                                         "itself - Aborting request!\n");
 361         } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 362                 unsigned int blocks =
 363                         (blk_rq_bytes(rq) - rq->resid_len) / tape->blk_size;
 364
 365                 tape->avg_size += blocks * tape->blk_size;
 366
 367                 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
 368                         tape->avg_speed = tape->avg_size * HZ /
 369                                 (jiffies - tape->avg_time) / 1024;
 370                         tape->avg_size = 0;
 371                         tape->avg_time = jiffies;
 372                 }
 373
 374                 tape->first_frame += blocks;
 375
 376                 if (pc->error) {
 377                         uptodate = 0;
 378                         err = pc->error;
 379                 }
 380         }
 381         rq->errors = err;
 382
 383         return uptodate;
 384 }
 385
 386 /*
 387  * Postpone the current request so that ide.c will be able to service requests
 388  * from another device on the same port while we are polling for DSC.
 389  */
 390 static void idetape_postpone_request(ide_drive_t *drive)
 391 {
 392         idetape_tape_t *tape = drive->driver_data;
 393
 394         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 395
 396         tape->postponed_rq = drive->hwif->rq;
 397
 398         ide_stall_queue(drive, tape->dsc_poll_freq);
 399 }
 400
 401 static void ide_tape_handle_dsc(ide_drive_t *drive)
 402 {
 403         idetape_tape_t *tape = drive->driver_data;
 404
 405         /* Media access command */
 406         tape->dsc_polling_start = jiffies;
 407         tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
 408         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
 409         /* Allow ide.c to handle other requests */
 410         idetape_postpone_request(drive);
 411 }
 412
 413 /*
 414  * Packet Command Interface
 415  *
 416  * The current Packet Command is available in drive->pc, and will not change
 417  * until we finish handling it. Each packet command is associated with a
 418  * callback function that will be called when the command is finished.
 419  *
 420  * The handling will be done in three stages:
 421  *
 422  * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
 423  * the interrupt handler to ide_pc_intr.
 424  *
 425  * 2. On each interrupt, ide_pc_intr will be called. This step will be
 426  * repeated until the device signals us that no more interrupts will be issued.
 427  *
 428  * 3. ATAPI Tape media access commands have immediate status with a delayed
 429  * process. In case of a successful initiation of a media access packet command,
 430  * the DSC bit will be set when the actual execution of the command is finished.
 431  * Since the tape drive will not issue an interrupt, we have to poll for this
 432  * event. In this case, we define the request as "low priority request" by
 433  * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 434  * exit the driver.
 435  *
 436  * ide.c will then give higher priority to requests which originate from the
 437  * other device, until will change rq_status to RQ_ACTIVE.
 438  *
 439  * 4. When the packet command is finished, it will be checked for errors.
 440  *
 441  * 5. In case an error was found, we queue a request sense packet command in
 442  * front of the request queue and retry the operation up to
 443  * IDETAPE_MAX_PC_RETRIES times.
 444  *
 445  * 6. In case no error was found, or we decided to give up and not to retry
 446  * again, the callback function will be called and then we will handle the next
 447  * request.
 448  */
 449
 450 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 451                                          struct ide_cmd *cmd,
 452                                          struct ide_atapi_pc *pc)
 453 {
 454         idetape_tape_t *tape = drive->driver_data;
 455         struct request *rq = drive->hwif->rq;
 456
 457         if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
 458                 drive->failed_pc = pc;
 459
 460         /* Set the current packet command */
 461         drive->pc = pc;
 462
 463         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
 464                 (pc->flags & PC_FLAG_ABORT)) {
 465
 466                 /*
 467                  * We will "abort" retrying a packet command in case legitimate
 468                  * error code was received (crossing a filemark, or end of the
 469                  * media, for example).
 470                  */
 471                 if (!(pc->flags & PC_FLAG_ABORT)) {
 472                         if (!(pc->c[0] == TEST_UNIT_READY &&
 473                               tape->sense_key == 2 && tape->asc == 4 &&
 474                              (tape->ascq == 1 || tape->ascq == 8))) {
 475                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
 476                                                 "pc = %2x, key = %2x, "
 477                                                 "asc = %2x, ascq = %2x\n",
 478                                                 tape->name, pc->c[0],
 479                                                 tape->sense_key, tape->asc,
 480                                                 tape->ascq);
 481                         }
 482                         /* Giving up */
 483                         pc->error = IDE_DRV_ERROR_GENERAL;
 484                 }
 485
 486                 drive->failed_pc = NULL;
 487                 drive->pc_callback(drive, 0);
 488                 ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
 489                 return ide_stopped;
 490         }
 491         debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
 492
 493         pc->retries++;
 494
 495         return ide_issue_pc(drive, cmd);
 496 }
 497
 498 /* A mode sense command is used to "sense" tape parameters. */
 499 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 500 {
 501         ide_init_pc(pc);
 502         pc->c[0] = MODE_SENSE;
 503         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
 504                 /* DBD = 1 - Don't return block descriptors */
 505                 pc->c[1] = 8;
 506         pc->c[2] = page_code;
 507         /*
 508          * Changed pc->c[3] to 0 (255 will at best return unused info).
 509          *
 510          * For SCSI this byte is defined as subpage instead of high byte
 511          * of length and some IDE drives seem to interpret it this way
 512          * and return an error when 255 is used.
 513          */
 514         pc->c[3] = 0;
 515         /* We will just discard data in that case */
 516         pc->c[4] = 255;
 517         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
 518                 pc->req_xfer = 12;
 519         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
 520                 pc->req_xfer = 24;
 521         else
 522                 pc->req_xfer = 50;
 523 }
 524
 525 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 526 {
 527         ide_hwif_t *hwif = drive->hwif;
 528         idetape_tape_t *tape = drive->driver_data;
 529         struct ide_atapi_pc *pc = drive->pc;
 530         u8 stat;
 531
 532         stat = hwif->tp_ops->read_status(hwif);
 533
 534         if (stat & ATA_DSC) {
 535                 if (stat & ATA_ERR) {
 536                         /* Error detected */
 537                         if (pc->c[0] != TEST_UNIT_READY)
 538                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
 539                                                 tape->name);
 540                         /* Retry operation */
 541                         ide_retry_pc(drive);
 542                         return ide_stopped;
 543                 }
 544                 pc->error = 0;
 545         } else {
 546                 pc->error = IDE_DRV_ERROR_GENERAL;
 547                 drive->failed_pc = NULL;
 548         }
 549         drive->pc_callback(drive, 0);
 550         return ide_stopped;
 551 }
 552
 553 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
 554                                    struct ide_atapi_pc *pc, struct request *rq,
 555                                    u8 opcode)
 556 {
 557         unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
 558
 559         ide_init_pc(pc);
 560         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
 561         pc->c[1] = 1;
 562
 563         if (blk_rq_bytes(rq) == tape->buffer_size)
 564                 pc->flags |= PC_FLAG_DMA_OK;
 565
 566         if (opcode == READ_6)
 567                 pc->c[0] = READ_6;
 568         else if (opcode == WRITE_6) {
 569                 pc->c[0] = WRITE_6;
 570                 pc->flags |= PC_FLAG_WRITING;
 571         }
 572
 573         memcpy(rq->cmd, pc->c, 12);
 574 }
 575
 576 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 577                                           struct request *rq, sector_t block)
 578 {
 579         ide_hwif_t *hwif = drive->hwif;
 580         idetape_tape_t *tape = drive->driver_data;
 581         struct ide_atapi_pc *pc = NULL;
 582         struct request *postponed_rq = tape->postponed_rq;
 583         struct ide_cmd cmd;
 584         u8 stat;
 585
 586         debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %u\n"
 587                   (unsigned long long)blk_rq_pos(rq), blk_rq_sectors(rq));
 588
 589         if (!(blk_special_request(rq) || blk_sense_request(rq))) {
 590                 /* We do not support buffer cache originated requests. */
 591                 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
 592                         "request queue (%d)\n", drive->name, rq->cmd_type);
 593                 if (blk_fs_request(rq) == 0 && rq->errors == 0)
 594                         rq->errors = -EIO;
 595                 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
 596                 return ide_stopped;
 597         }
 598
 599         /* Retry a failed packet command */
 600         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 601                 pc = drive->failed_pc;
 602                 goto out;
 603         }
 604
 605         if (postponed_rq != NULL)
 606                 if (rq != postponed_rq) {
 607                         printk(KERN_ERR "ide-tape: ide-tape.c bug - "
 608                                         "Two DSC requests were queued\n");
 609                         drive->failed_pc = NULL;
 610                         rq->errors = 0;
 611                         ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 612                         return ide_stopped;
 613                 }
 614
 615         tape->postponed_rq = NULL;
 616
 617         /*
 618          * If the tape is still busy, postpone our request and service
 619          * the other device meanwhile.
 620          */
 621         stat = hwif->tp_ops->read_status(hwif);
 622
 623         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 624             (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
 625                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 626
 627         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 628                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 629                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 630         }
 631
 632         if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
 633             !(stat & ATA_DSC)) {
 634                 if (postponed_rq == NULL) {
 635                         tape->dsc_polling_start = jiffies;
 636                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 637                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 638                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 639                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 640                                 tape->name);
 641                         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 642                                 idetape_media_access_finished(drive);
 643                                 return ide_stopped;
 644                         } else {
 645                                 return ide_do_reset(drive);
 646                         }
 647                 } else if (time_after(jiffies,
 648                                         tape->dsc_polling_start +
 649                                         IDETAPE_DSC_MA_THRESHOLD))
 650                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 651                 idetape_postpone_request(drive);
 652                 return ide_stopped;
 653         } else
 654                 drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
 655
 656         if (rq->cmd[13] & REQ_IDETAPE_READ) {
 657                 pc = &tape->queued_pc;
 658                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 659                 goto out;
 660         }
 661         if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
 662                 pc = &tape->queued_pc;
 663                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 664                 goto out;
 665         }
 666         if (rq->cmd[13] & REQ_IDETAPE_PC1) {
 667                 pc = (struct ide_atapi_pc *)rq->special;
 668                 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
 669                 rq->cmd[13] |= REQ_IDETAPE_PC2;
 670                 goto out;
 671         }
 672         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 673                 idetape_media_access_finished(drive);
 674                 return ide_stopped;
 675         }
 676         BUG();
 677
 678 out:
 679         /* prepare sense request for this command */
 680         ide_prep_sense(drive, rq);
 681
 682         memset(&cmd, 0, sizeof(cmd));
 683
 684         if (rq_data_dir(rq))
 685                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 686
 687         cmd.rq = rq;
 688
 689         ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
 690         ide_map_sg(drive, &cmd);
 691
 692         return ide_tape_issue_pc(drive, &cmd, pc);
 693 }
 694
 695 /*
 696  * Write a filemark if write_filemark=1. Flush the device buffers without
 697  * writing a filemark otherwise.
 698  */
 699 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 700                 struct ide_atapi_pc *pc, int write_filemark)
 701 {
 702         ide_init_pc(pc);
 703         pc->c[0] = WRITE_FILEMARKS;
 704         pc->c[4] = write_filemark;
 705         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 706 }
 707
 708 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 709 {
 710         idetape_tape_t *tape = drive->driver_data;
 711         struct gendisk *disk = tape->disk;
 712         int load_attempted = 0;
 713
 714         /* Wait for the tape to become ready */
 715         set_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT), &drive->atapi_flags);
 716         timeout += jiffies;
 717         while (time_before(jiffies, timeout)) {
 718                 if (ide_do_test_unit_ready(drive, disk) == 0)
 719                         return 0;
 720                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 721                     || (tape->asc == 0x3A)) {
 722                         /* no media */
 723                         if (load_attempted)
 724                                 return -ENOMEDIUM;
 725                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 726                         load_attempted = 1;
 727                 /* not about to be ready */
 728                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 729                              (tape->ascq == 1 || tape->ascq == 8)))
 730                         return -EIO;
 731                 msleep(100);
 732         }
 733         return -EIO;
 734 }
 735
 736 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 737 {
 738         struct ide_tape_obj *tape = drive->driver_data;
 739         struct ide_atapi_pc pc;
 740         int rc;
 741
 742         idetape_create_write_filemark_cmd(drive, &pc, 0);
 743         rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
 744         if (rc)
 745                 return rc;
 746         idetape_wait_ready(drive, 60 * 5 * HZ);
 747         return 0;
 748 }
 749
 750 static int ide_tape_read_position(ide_drive_t *drive)
 751 {
 752         idetape_tape_t *tape = drive->driver_data;
 753         struct ide_atapi_pc pc;
 754         u8 buf[20];
 755
 756         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 757
 758         /* prep cmd */
 759         ide_init_pc(&pc);
 760         pc.c[0] = READ_POSITION;
 761         pc.req_xfer = 20;
 762
 763         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
 764                 return -1;
 765
 766         if (!pc.error) {
 767                 debug_log(DBG_SENSE, "BOP - %s\n",
 768                                 (buf[0] & 0x80) ? "Yes" : "No");
 769                 debug_log(DBG_SENSE, "EOP - %s\n",
 770                                 (buf[0] & 0x40) ? "Yes" : "No");
 771
 772                 if (buf[0] & 0x4) {
 773                         printk(KERN_INFO "ide-tape: Block location is unknown"
 774                                          "to the tape\n");
 775                         clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 776                                   &drive->atapi_flags);
 777                         return -1;
 778                 } else {
 779                         debug_log(DBG_SENSE, "Block Location - %u\n",
 780                                         be32_to_cpup((__be32 *)&buf[4]));
 781
 782                         tape->partition = buf[1];
 783                         tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
 784                         set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 785                                 &drive->atapi_flags);
 786                 }
 787         }
 788
 789         return tape->first_frame;
 790 }
 791
 792 static void idetape_create_locate_cmd(ide_drive_t *drive,
 793                 struct ide_atapi_pc *pc,
 794                 unsigned int block, u8 partition, int skip)
 795 {
 796         ide_init_pc(pc);
 797         pc->c[0] = POSITION_TO_ELEMENT;
 798         pc->c[1] = 2;
 799         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 800         pc->c[8] = partition;
 801         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 802 }
 803
 804 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 805 {
 806         idetape_tape_t *tape = drive->driver_data;
 807
 808         if (tape->chrdev_dir != IDETAPE_DIR_READ)
 809                 return;
 810
 811         clear_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
 812         tape->valid = 0;
 813         if (tape->buf != NULL) {
 814                 kfree(tape->buf);
 815                 tape->buf = NULL;
 816         }
 817
 818         tape->chrdev_dir = IDETAPE_DIR_NONE;
 819 }
 820
 821 /*
 822  * Position the tape to the requested block using the LOCATE packet command.
 823  * A READ POSITION command is then issued to check where we are positioned. Like
 824  * all higher level operations, we queue the commands at the tail of the request
 825  * queue and wait for their completion.
 826  */
 827 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 828                 u8 partition, int skip)
 829 {
 830         idetape_tape_t *tape = drive->driver_data;
 831         struct gendisk *disk = tape->disk;
 832         int ret;
 833         struct ide_atapi_pc pc;
 834
 835         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 836                 __ide_tape_discard_merge_buffer(drive);
 837         idetape_wait_ready(drive, 60 * 5 * HZ);
 838         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 839         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 840         if (ret)
 841                 return ret;
 842
 843         ret = ide_tape_read_position(drive);
 844         if (ret < 0)
 845                 return ret;
 846         return 0;
 847 }
 848
 849 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 850                                           int restore_position)
 851 {
 852         idetape_tape_t *tape = drive->driver_data;
 853         int seek, position;
 854
 855         __ide_tape_discard_merge_buffer(drive);
 856         if (restore_position) {
 857                 position = ide_tape_read_position(drive);
 858                 seek = position > 0 ? position : 0;
 859                 if (idetape_position_tape(drive, seek, 0, 0)) {
 860                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 861                                          " %s\n", tape->name, __func__);
 862                         return;
 863                 }
 864         }
 865 }
 866
 867 /*
 868  * Generate a read/write request for the block device interface and wait for it
 869  * to be serviced.
 870  */
 871 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 872 {
 873         idetape_tape_t *tape = drive->driver_data;
 874         struct request *rq;
 875         int ret;
 876
 877         debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
 878         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 879         BUG_ON(size < 0 || size % tape->blk_size);
 880
 881         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
 882         rq->cmd_type = REQ_TYPE_SPECIAL;
 883         rq->cmd[13] = cmd;
 884         rq->rq_disk = tape->disk;
 885         rq->__sector = tape->first_frame;
 886
 887         if (size) {
 888                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 889                                       __GFP_WAIT);
 890                 if (ret)
 891                         goto out_put;
 892         }
 893
 894         blk_execute_rq(drive->queue, tape->disk, rq, 0);
 895
 896         /* calculate the number of transferred bytes and update buffer state */
 897         size -= rq->resid_len;
 898         tape->cur = tape->buf;
 899         if (cmd == REQ_IDETAPE_READ)
 900                 tape->valid = size;
 901         else
 902                 tape->valid = 0;
 903
 904         ret = size;
 905         if (rq->errors == IDE_DRV_ERROR_GENERAL)
 906                 ret = -EIO;
 907 out_put:
 908         blk_put_request(rq);
 909         return ret;
 910 }
 911
 912 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 913 {
 914         ide_init_pc(pc);
 915         pc->c[0] = INQUIRY;
 916         pc->c[4] = 254;
 917         pc->req_xfer = 254;
 918 }
 919
 920 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 921                 struct ide_atapi_pc *pc)
 922 {
 923         ide_init_pc(pc);
 924         pc->c[0] = REZERO_UNIT;
 925         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 926 }
 927
 928 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 929 {
 930         ide_init_pc(pc);
 931         pc->c[0] = ERASE;
 932         pc->c[1] = 1;
 933         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 934 }
 935
 936 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 937 {
 938         ide_init_pc(pc);
 939         pc->c[0] = SPACE;
 940         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 941         pc->c[1] = cmd;
 942         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 943 }
 944
 945 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 946 {
 947         idetape_tape_t *tape = drive->driver_data;
 948
 949         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 950                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 951                                 " but we are not writing.\n");
 952                 return;
 953         }
 954         if (tape->buf) {
 955                 size_t aligned = roundup(tape->valid, tape->blk_size);
 956
 957                 memset(tape->cur, 0, aligned - tape->valid);
 958                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 959                 kfree(tape->buf);
 960                 tape->buf = NULL;
 961         }
 962         tape->chrdev_dir = IDETAPE_DIR_NONE;
 963 }
 964
 965 static int idetape_init_rw(ide_drive_t *drive, int dir)
 966 {
 967         idetape_tape_t *tape = drive->driver_data;
 968         int rc;
 969
 970         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 971
 972         if (tape->chrdev_dir == dir)
 973                 return 0;
 974
 975         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 976                 ide_tape_discard_merge_buffer(drive, 1);
 977         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 978                 ide_tape_flush_merge_buffer(drive);
 979                 idetape_flush_tape_buffers(drive);
 980         }
 981
 982         if (tape->buf || tape->valid) {
 983                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 984                 tape->valid = 0;
 985         }
 986
 987         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 988         if (!tape->buf)
 989                 return -ENOMEM;
 990         tape->chrdev_dir = dir;
 991         tape->cur = tape->buf;
 992
 993         /*
 994          * Issue a 0 rw command to ensure that DSC handshake is
 995          * switched from completion mode to buffer available mode.  No
 996          * point in issuing this if DSC overlap isn't supported, some
 997          * drives (Seagate STT3401A) will return an error.
 998          */
 999         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1000                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
1001                                                   : REQ_IDETAPE_WRITE;
1002
1003                 rc = idetape_queue_rw_tail(drive, cmd, 0);
1004                 if (rc < 0) {
1005                         kfree(tape->buf);
1006                         tape->buf = NULL;
1007                         tape->chrdev_dir = IDETAPE_DIR_NONE;
1008                         return rc;
1009                 }
1010         }
1011
1012         return 0;
1013 }
1014
1015 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
1016 {
1017         idetape_tape_t *tape = drive->driver_data;
1018
1019         memset(tape->buf, 0, tape->buffer_size);
1020
1021         while (bcount) {
1022                 unsigned int count = min(tape->buffer_size, bcount);
1023
1024                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1025                 bcount -= count;
1026         }
1027 }
1028
1029 /*
1030  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1031  * currently support only one partition.
1032  */
1033 static int idetape_rewind_tape(ide_drive_t *drive)
1034 {
1035         struct ide_tape_obj *tape = drive->driver_data;
1036         struct gendisk *disk = tape->disk;
1037         struct ide_atapi_pc pc;
1038         int ret;
1039
1040         debug_log(DBG_SENSE, "Enter %s\n", __func__);
1041
1042         idetape_create_rewind_cmd(drive, &pc);
1043         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1044         if (ret)
1045                 return ret;
1046
1047         ret = ide_tape_read_position(drive);
1048         if (ret < 0)
1049                 return ret;
1050         return 0;
1051 }
1052
1053 /* mtio.h compatible commands should be issued to the chrdev interface. */
1054 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1055                                 unsigned long arg)
1056 {
1057         idetape_tape_t *tape = drive->driver_data;
1058         void __user *argp = (void __user *)arg;
1059
1060         struct idetape_config {
1061                 int dsc_rw_frequency;
1062                 int dsc_media_access_frequency;
1063                 int nr_stages;
1064         } config;
1065
1066         debug_log(DBG_PROCS, "Enter %s\n", __func__);
1067
1068         switch (cmd) {
1069         case 0x0340:
1070                 if (copy_from_user(&config, argp, sizeof(config)))
1071                         return -EFAULT;
1072                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1073                 break;
1074         case 0x0350:
1075                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1076                 config.nr_stages = 1;
1077                 if (copy_to_user(argp, &config, sizeof(config)))
1078                         return -EFAULT;
1079                 break;
1080         default:
1081                 return -EIO;
1082         }
1083         return 0;
1084 }
1085
1086 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1087                                         int mt_count)
1088 {
1089         idetape_tape_t *tape = drive->driver_data;
1090         struct gendisk *disk = tape->disk;
1091         struct ide_atapi_pc pc;
1092         int retval, count = 0;
1093         int sprev = !!(tape->caps[4] & 0x20);
1094
1095         if (mt_count == 0)
1096                 return 0;
1097         if (MTBSF == mt_op || MTBSFM == mt_op) {
1098                 if (!sprev)
1099                         return -EIO;
1100                 mt_count = -mt_count;
1101         }
1102
1103         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1104                 tape->valid = 0;
1105                 if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1106                                        &drive->atapi_flags))
1107                         ++count;
1108                 ide_tape_discard_merge_buffer(drive, 0);
1109         }
1110
1111         switch (mt_op) {
1112         case MTFSF:
1113         case MTBSF:
1114                 idetape_create_space_cmd(&pc, mt_count - count,
1115                                          IDETAPE_SPACE_OVER_FILEMARK);
1116                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1117         case MTFSFM:
1118         case MTBSFM:
1119                 if (!sprev)
1120                         return -EIO;
1121                 retval = idetape_space_over_filemarks(drive, MTFSF,
1122                                                       mt_count - count);
1123                 if (retval)
1124                         return retval;
1125                 count = (MTBSFM == mt_op ? 1 : -1);
1126                 return idetape_space_over_filemarks(drive, MTFSF, count);
1127         default:
1128                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1129                                 mt_op);
1130                 return -EIO;
1131         }
1132 }
1133
1134 /*
1135  * Our character device read / write functions.
1136  *
1137  * The tape is optimized to maximize throughput when it is transferring an
1138  * integral number of the "continuous transfer limit", which is a parameter of
1139  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1140  *
1141  * As of version 1.3 of the driver, the character device provides an abstract
1142  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1143  * same backup/restore procedure is supported. The driver will internally
1144  * convert the requests to the recommended transfer unit, so that an unmatch
1145  * between the user's block size to the recommended size will only result in a
1146  * (slightly) increased driver overhead, but will no longer hit performance.
1147  * This is not applicable to Onstream.
1148  */
1149 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1150                                    size_t count, loff_t *ppos)
1151 {
1152         struct ide_tape_obj *tape = file->private_data;
1153         ide_drive_t *drive = tape->drive;
1154         size_t done = 0;
1155         ssize_t ret = 0;
1156         int rc;
1157
1158         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1159
1160         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1161                 if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1162                         if (count > tape->blk_size &&
1163                             (count % tape->blk_size) == 0)
1164                                 tape->user_bs_factor = count / tape->blk_size;
1165         }
1166
1167         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1168         if (rc < 0)
1169                 return rc;
1170
1171         while (done < count) {
1172                 size_t todo;
1173
1174                 /* refill if staging buffer is empty */
1175                 if (!tape->valid) {
1176                         /* If we are at a filemark, nothing more to read */
1177                         if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1178                                      &drive->atapi_flags))
1179                                 break;
1180                         /* read */
1181                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1182                                                   tape->buffer_size) <= 0)
1183                                 break;
1184                 }
1185
1186                 /* copy out */
1187                 todo = min_t(size_t, count - done, tape->valid);
1188                 if (copy_to_user(buf + done, tape->cur, todo))
1189                         ret = -EFAULT;
1190
1191                 tape->cur += todo;
1192                 tape->valid -= todo;
1193                 done += todo;
1194         }
1195
1196         if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1197                 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
1198
1199                 idetape_space_over_filemarks(drive, MTFSF, 1);
1200                 return 0;
1201         }
1202
1203         return ret ? ret : done;
1204 }
1205
1206 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1207                                      size_t count, loff_t *ppos)
1208 {
1209         struct ide_tape_obj *tape = file->private_data;
1210         ide_drive_t *drive = tape->drive;
1211         size_t done = 0;
1212         ssize_t ret = 0;
1213         int rc;
1214
1215         /* The drive is write protected. */
1216         if (tape->write_prot)
1217                 return -EACCES;
1218
1219         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1220
1221         /* Initialize write operation */
1222         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1223         if (rc < 0)
1224                 return rc;
1225
1226         while (done < count) {
1227                 size_t todo;
1228
1229                 /* flush if staging buffer is full */
1230                 if (tape->valid == tape->buffer_size &&
1231                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1232                                           tape->buffer_size) <= 0)
1233                         return rc;
1234
1235                 /* copy in */
1236                 todo = min_t(size_t, count - done,
1237                              tape->buffer_size - tape->valid);
1238                 if (copy_from_user(tape->cur, buf + done, todo))
1239                         ret = -EFAULT;
1240
1241                 tape->cur += todo;
1242                 tape->valid += todo;
1243                 done += todo;
1244         }
1245
1246         return ret ? ret : done;
1247 }
1248
1249 static int idetape_write_filemark(ide_drive_t *drive)
1250 {
1251         struct ide_tape_obj *tape = drive->driver_data;
1252         struct ide_atapi_pc pc;
1253
1254         /* Write a filemark */
1255         idetape_create_write_filemark_cmd(drive, &pc, 1);
1256         if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1257                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1258                 return -EIO;
1259         }
1260         return 0;
1261 }
1262
1263 /*
1264  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1265  * requested.
1266  *
1267  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1268  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1269  * usually not supported.
1270  *
1271  * The following commands are currently not supported:
1272  *
1273  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1274  * MT_ST_WRITE_THRESHOLD.
1275  */
1276 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1277 {
1278         idetape_tape_t *tape = drive->driver_data;
1279         struct gendisk *disk = tape->disk;
1280         struct ide_atapi_pc pc;
1281         int i, retval;
1282
1283         debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
1284                         mt_op, mt_count);
1285
1286         switch (mt_op) {
1287         case MTFSF:
1288         case MTFSFM:
1289         case MTBSF:
1290         case MTBSFM:
1291                 if (!mt_count)
1292                         return 0;
1293                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1294         default:
1295                 break;
1296         }
1297
1298         switch (mt_op) {
1299         case MTWEOF:
1300                 if (tape->write_prot)
1301                         return -EACCES;
1302                 ide_tape_discard_merge_buffer(drive, 1);
1303                 for (i = 0; i < mt_count; i++) {
1304                         retval = idetape_write_filemark(drive);
1305                         if (retval)
1306                                 return retval;
1307                 }
1308                 return 0;
1309         case MTREW:
1310                 ide_tape_discard_merge_buffer(drive, 0);
1311                 if (idetape_rewind_tape(drive))
1312                         return -EIO;
1313                 return 0;
1314         case MTLOAD:
1315                 ide_tape_discard_merge_buffer(drive, 0);
1316                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1317         case MTUNLOAD:
1318         case MTOFFL:
1319                 /*
1320                  * If door is locked, attempt to unlock before
1321                  * attempting to eject.
1322                  */
1323                 if (tape->door_locked) {
1324                         if (!ide_set_media_lock(drive, disk, 0))
1325                                 tape->door_locked = DOOR_UNLOCKED;
1326                 }
1327                 ide_tape_discard_merge_buffer(drive, 0);
1328                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1329                 if (!retval)
1330                         clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1331                                   &drive->atapi_flags);
1332                 return retval;
1333         case MTNOP:
1334                 ide_tape_discard_merge_buffer(drive, 0);
1335                 return idetape_flush_tape_buffers(drive);
1336         case MTRETEN:
1337                 ide_tape_discard_merge_buffer(drive, 0);
1338                 return ide_do_start_stop(drive, disk,
1339                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1340         case MTEOM:
1341                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1342                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1343         case MTERASE:
1344                 (void)idetape_rewind_tape(drive);
1345                 idetape_create_erase_cmd(&pc);
1346                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1347         case MTSETBLK:
1348                 if (mt_count) {
1349                         if (mt_count < tape->blk_size ||
1350                             mt_count % tape->blk_size)
1351                                 return -EIO;
1352                         tape->user_bs_factor = mt_count / tape->blk_size;
1353                         clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1354                                   &drive->atapi_flags);
1355                 } else
1356                         set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1357                                 &drive->atapi_flags);
1358                 return 0;
1359         case MTSEEK:
1360                 ide_tape_discard_merge_buffer(drive, 0);
1361                 return idetape_position_tape(drive,
1362                         mt_count * tape->user_bs_factor, tape->partition, 0);
1363         case MTSETPART:
1364                 ide_tape_discard_merge_buffer(drive, 0);
1365                 return idetape_position_tape(drive, 0, mt_count, 0);
1366         case MTFSR:
1367         case MTBSR:
1368         case MTLOCK:
1369                 retval = ide_set_media_lock(drive, disk, 1);
1370                 if (retval)
1371                         return retval;
1372                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1373                 return 0;
1374         case MTUNLOCK:
1375                 retval = ide_set_media_lock(drive, disk, 0);
1376                 if (retval)
1377                         return retval;
1378                 tape->door_locked = DOOR_UNLOCKED;
1379                 return 0;
1380         default:
1381                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1382                                 mt_op);
1383                 return -EIO;
1384         }
1385 }
1386
1387 /*
1388  * Our character device ioctls. General mtio.h magnetic io commands are
1389  * supported here, and not in the corresponding block interface. Our own
1390  * ide-tape ioctls are supported on both interfaces.
1391  */
1392 static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
1393                                 unsigned int cmd, unsigned long arg)
1394 {
1395         struct ide_tape_obj *tape = file->private_data;
1396         ide_drive_t *drive = tape->drive;
1397         struct mtop mtop;
1398         struct mtget mtget;
1399         struct mtpos mtpos;
1400         int block_offset = 0, position = tape->first_frame;
1401         void __user *argp = (void __user *)arg;
1402
1403         debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
1404
1405         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1406                 ide_tape_flush_merge_buffer(drive);
1407                 idetape_flush_tape_buffers(drive);
1408         }
1409         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1410                 block_offset = tape->valid /
1411                         (tape->blk_size * tape->user_bs_factor);
1412                 position = ide_tape_read_position(drive);
1413                 if (position < 0)
1414                         return -EIO;
1415         }
1416         switch (cmd) {
1417         case MTIOCTOP:
1418                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1419                         return -EFAULT;
1420                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1421         case MTIOCGET:
1422                 memset(&mtget, 0, sizeof(struct mtget));
1423                 mtget.mt_type = MT_ISSCSI2;
1424                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1425                 mtget.mt_dsreg =
1426                         ((tape->blk_size * tape->user_bs_factor)
1427                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1428
1429                 if (tape->drv_write_prot)
1430                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1431
1432                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1433                         return -EFAULT;
1434                 return 0;
1435         case MTIOCPOS:
1436                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1437                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1438                         return -EFAULT;
1439                 return 0;
1440         default:
1441                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1442                         ide_tape_discard_merge_buffer(drive, 1);
1443                 return idetape_blkdev_ioctl(drive, cmd, arg);
1444         }
1445 }
1446
1447 /*
1448  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1449  * block size with the reported value.
1450  */
1451 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1452 {
1453         idetape_tape_t *tape = drive->driver_data;
1454         struct ide_atapi_pc pc;
1455         u8 buf[12];
1456
1457         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1458         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1459                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1460                 if (tape->blk_size == 0) {
1461                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1462                                             "block size, assuming 32k\n");
1463                         tape->blk_size = 32768;
1464                 }
1465                 return;
1466         }
1467         tape->blk_size = (buf[4 + 5] << 16) +
1468                                 (buf[4 + 6] << 8)  +
1469                                  buf[4 + 7];
1470         tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1471 }
1472
1473 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1474 {
1475         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1476         ide_drive_t *drive;
1477         idetape_tape_t *tape;
1478         int retval;
1479
1480         if (i >= MAX_HWIFS * MAX_DRIVES)
1481                 return -ENXIO;
1482
1483         lock_kernel();
1484         tape = ide_tape_get(NULL, true, i);
1485         if (!tape) {
1486                 unlock_kernel();
1487                 return -ENXIO;
1488         }
1489
1490         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1491
1492         /*
1493          * We really want to do nonseekable_open(inode, filp); here, but some
1494          * versions of tar incorrectly call lseek on tapes and bail out if that
1495          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1496          */
1497         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1498
1499         drive = tape->drive;
1500
1501         filp->private_data = tape;
1502
1503         if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1504                 retval = -EBUSY;
1505                 goto out_put_tape;
1506         }
1507
1508         retval = idetape_wait_ready(drive, 60 * HZ);
1509         if (retval) {
1510                 clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1511                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1512                 goto out_put_tape;
1513         }
1514
1515         idetape_read_position(drive);
1516         if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1517                 (void)idetape_rewind_tape(drive);
1518
1519         /* Read block size and write protect status from drive. */
1520         ide_tape_get_bsize_from_bdesc(drive);
1521
1522         /* Set write protect flag if device is opened as read-only. */
1523         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1524                 tape->write_prot = 1;
1525         else
1526                 tape->write_prot = tape->drv_write_prot;
1527
1528         /* Make sure drive isn't write protected if user wants to write. */
1529         if (tape->write_prot) {
1530                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1531                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1532                         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1533                         retval = -EROFS;
1534                         goto out_put_tape;
1535                 }
1536         }
1537
1538         /* Lock the tape drive door so user can't eject. */
1539         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1540                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1541                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1542                                 tape->door_locked = DOOR_LOCKED;
1543                 }
1544         }
1545         unlock_kernel();
1546         return 0;
1547
1548 out_put_tape:
1549         ide_tape_put(tape);
1550         unlock_kernel();
1551         return retval;
1552 }
1553
1554 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1555 {
1556         idetape_tape_t *tape = drive->driver_data;
1557
1558         ide_tape_flush_merge_buffer(drive);
1559         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1560         if (tape->buf != NULL) {
1561                 idetape_pad_zeros(drive, tape->blk_size *
1562                                 (tape->user_bs_factor - 1));
1563                 kfree(tape->buf);
1564                 tape->buf = NULL;
1565         }
1566         idetape_write_filemark(drive);
1567         idetape_flush_tape_buffers(drive);
1568         idetape_flush_tape_buffers(drive);
1569 }
1570
1571 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1572 {
1573         struct ide_tape_obj *tape = filp->private_data;
1574         ide_drive_t *drive = tape->drive;
1575         unsigned int minor = iminor(inode);
1576
1577         lock_kernel();
1578         tape = drive->driver_data;
1579
1580         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1581
1582         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1583                 idetape_write_release(drive, minor);
1584         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1585                 if (minor < 128)
1586                         ide_tape_discard_merge_buffer(drive, 1);
1587         }
1588
1589         if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1590                                     &drive->atapi_flags))
1591                 (void) idetape_rewind_tape(drive);
1592
1593         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1594                 if (tape->door_locked == DOOR_LOCKED) {
1595                         if (!ide_set_media_lock(drive, tape->disk, 0))
1596                                 tape->door_locked = DOOR_UNLOCKED;
1597                 }
1598         }
1599         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1600         ide_tape_put(tape);
1601         unlock_kernel();
1602         return 0;
1603 }
1604
1605 static void idetape_get_inquiry_results(ide_drive_t *drive)
1606 {
1607         idetape_tape_t *tape = drive->driver_data;
1608         struct ide_atapi_pc pc;
1609         u8 pc_buf[256];
1610         char fw_rev[4], vendor_id[8], product_id[16];
1611
1612         idetape_create_inquiry_cmd(&pc);
1613         if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1614                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1615                                 tape->name);
1616                 return;
1617         }
1618         memcpy(vendor_id, &pc_buf[8], 8);
1619         memcpy(product_id, &pc_buf[16], 16);
1620         memcpy(fw_rev, &pc_buf[32], 4);
1621
1622         ide_fixstring(vendor_id, 8, 0);
1623         ide_fixstring(product_id, 16, 0);
1624         ide_fixstring(fw_rev, 4, 0);
1625
1626         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1627                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1628 }
1629
1630 /*
1631  * Ask the tape about its various parameters. In particular, we will adjust our
1632  * data transfer buffer size to the recommended value as returned by the tape.
1633  */
1634 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1635 {
1636         idetape_tape_t *tape = drive->driver_data;
1637         struct ide_atapi_pc pc;
1638         u8 buf[24], *caps;
1639         u8 speed, max_speed;
1640
1641         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1642         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1643                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1644                                 " some default values\n");
1645                 tape->blk_size = 512;
1646                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1647                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1648                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1649                 return;
1650         }
1651         caps = buf + 4 + buf[3];
1652
1653         /* convert to host order and save for later use */
1654         speed = be16_to_cpup((__be16 *)&caps[14]);
1655         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1656
1657         *(u16 *)&caps[8] = max_speed;
1658         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1659         *(u16 *)&caps[14] = speed;
1660         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1661
1662         if (!speed) {
1663                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1664                                 "(assuming 650KB/sec)\n", drive->name);
1665                 *(u16 *)&caps[14] = 650;
1666         }
1667         if (!max_speed) {
1668                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1669                                 "(assuming 650KB/sec)\n", drive->name);
1670                 *(u16 *)&caps[8] = 650;
1671         }
1672
1673         memcpy(&tape->caps, caps, 20);
1674
1675         /* device lacks locking support according to capabilities page */
1676         if ((caps[6] & 1) == 0)
1677                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1678
1679         if (caps[7] & 0x02)
1680                 tape->blk_size = 512;
1681         else if (caps[7] & 0x04)
1682                 tape->blk_size = 1024;
1683 }
1684
1685 #ifdef CONFIG_IDE_PROC_FS
1686 #define ide_tape_devset_get(name, field) \
1687 static int get_##name(ide_drive_t *drive) \
1688 { \
1689         idetape_tape_t *tape = drive->driver_data; \
1690         return tape->field; \
1691 }
1692
1693 #define ide_tape_devset_set(name, field) \
1694 static int set_##name(ide_drive_t *drive, int arg) \
1695 { \
1696         idetape_tape_t *tape = drive->driver_data; \
1697         tape->field = arg; \
1698         return 0; \
1699 }
1700
1701 #define ide_tape_devset_rw_field(_name, _field) \
1702 ide_tape_devset_get(_name, _field) \
1703 ide_tape_devset_set(_name, _field) \
1704 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1705
1706 #define ide_tape_devset_r_field(_name, _field) \
1707 ide_tape_devset_get(_name, _field) \
1708 IDE_DEVSET(_name, 0, get_##_name, NULL)
1709
1710 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1711 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1712 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1713 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1714
1715 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1716
1717 ide_tape_devset_rw_field(debug_mask, debug_mask);
1718 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1719
1720 ide_tape_devset_r_field(avg_speed, avg_speed);
1721 ide_tape_devset_r_field(speed, caps[14]);
1722 ide_tape_devset_r_field(buffer, caps[16]);
1723 ide_tape_devset_r_field(buffer_size, buffer_size);
1724
1725 static const struct ide_proc_devset idetape_settings[] = {
1726         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1727         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1728         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1729         __IDE_PROC_DEVSET(debug_mask,   0, 0xffff, NULL, NULL),
1730         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1731         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1732         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1733                                         mulf_tdsc, divf_tdsc),
1734         { NULL },
1735 };
1736 #endif
1737
1738 /*
1739  * The function below is called to:
1740  *
1741  * 1. Initialize our various state variables.
1742  * 2. Ask the tape for its capabilities.
1743  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1744  * is chosen based on the recommendation which we received in step 2.
1745  *
1746  * Note that at this point ide.c already assigned us an irq, so that we can
1747  * queue requests here and wait for their completion.
1748  */
1749 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1750 {
1751         unsigned long t;
1752         int speed;
1753         int buffer_size;
1754         u16 *ctl = (u16 *)&tape->caps[12];
1755
1756         drive->pc_callback       = ide_tape_callback;
1757
1758         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1759
1760         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1761                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1762                                  tape->name);
1763                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1764         }
1765
1766         /* Seagate Travan drives do not support DSC overlap. */
1767         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1768                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1769
1770         tape->minor = minor;
1771         tape->name[0] = 'h';
1772         tape->name[1] = 't';
1773         tape->name[2] = '0' + minor;
1774         tape->chrdev_dir = IDETAPE_DIR_NONE;
1775
1776         idetape_get_inquiry_results(drive);
1777         idetape_get_mode_sense_results(drive);
1778         ide_tape_get_bsize_from_bdesc(drive);
1779         tape->user_bs_factor = 1;
1780         tape->buffer_size = *ctl * tape->blk_size;
1781         while (tape->buffer_size > 0xffff) {
1782                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1783                 *ctl /= 2;
1784                 tape->buffer_size = *ctl * tape->blk_size;
1785         }
1786         buffer_size = tape->buffer_size;
1787
1788         /* select the "best" DSC read/write polling freq */
1789         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1790
1791         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1792
1793         /*
1794          * Ensure that the number we got makes sense; limit it within
1795          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1796          */
1797         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1798                                          IDETAPE_DSC_RW_MAX);
1799         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1800                 "%lums tDSC%s\n",
1801                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1802                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1803                 tape->buffer_size / 1024,
1804                 tape->best_dsc_rw_freq * 1000 / HZ,
1805                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1806
1807         ide_proc_register_driver(drive, tape->driver);
1808 }
1809
1810 static void ide_tape_remove(ide_drive_t *drive)
1811 {
1812         idetape_tape_t *tape = drive->driver_data;
1813
1814         ide_proc_unregister_driver(drive, tape->driver);
1815         device_del(&tape->dev);
1816         ide_unregister_region(tape->disk);
1817
1818         mutex_lock(&idetape_ref_mutex);
1819         put_device(&tape->dev);
1820         mutex_unlock(&idetape_ref_mutex);
1821 }
1822
1823 static void ide_tape_release(struct device *dev)
1824 {
1825         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1826         ide_drive_t *drive = tape->drive;
1827         struct gendisk *g = tape->disk;
1828
1829         BUG_ON(tape->valid);
1830
1831         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1832         drive->driver_data = NULL;
1833         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1834         device_destroy(idetape_sysfs_class,
1835                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1836         idetape_devs[tape->minor] = NULL;
1837         g->private_data = NULL;
1838         put_disk(g);
1839         kfree(tape);
1840 }
1841
1842 #ifdef CONFIG_IDE_PROC_FS
1843 static int proc_idetape_read_name
1844         (char *page, char **start, off_t off, int count, int *eof, void *data)
1845 {
1846         ide_drive_t     *drive = (ide_drive_t *) data;
1847         idetape_tape_t  *tape = drive->driver_data;
1848         char            *out = page;
1849         int             len;
1850
1851         len = sprintf(out, "%s\n", tape->name);
1852         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
1853 }
1854
1855 static ide_proc_entry_t idetape_proc[] = {
1856         { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
1857         { "name",       S_IFREG|S_IRUGO,        proc_idetape_read_name, NULL },
1858         { NULL, 0, NULL, NULL }
1859 };
1860
1861 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1862 {
1863         return idetape_proc;
1864 }
1865
1866 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1867 {
1868         return idetape_settings;
1869 }
1870 #endif
1871
1872 static int ide_tape_probe(ide_drive_t *);
1873
1874 static struct ide_driver idetape_driver = {
1875         .gen_driver = {
1876                 .owner          = THIS_MODULE,
1877                 .name           = "ide-tape",
1878                 .bus            = &ide_bus_type,
1879         },
1880         .probe                  = ide_tape_probe,
1881         .remove                 = ide_tape_remove,
1882         .version                = IDETAPE_VERSION,
1883         .do_request             = idetape_do_request,
1884 #ifdef CONFIG_IDE_PROC_FS
1885         .proc_entries           = ide_tape_proc_entries,
1886         .proc_devsets           = ide_tape_proc_devsets,
1887 #endif
1888 };
1889
1890 /* Our character device supporting functions, passed to register_chrdev. */
1891 static const struct file_operations idetape_fops = {
1892         .owner          = THIS_MODULE,
1893         .read           = idetape_chrdev_read,
1894         .write          = idetape_chrdev_write,
1895         .ioctl          = idetape_chrdev_ioctl,
1896         .open           = idetape_chrdev_open,
1897         .release        = idetape_chrdev_release,
1898 };
1899
1900 static int idetape_open(struct block_device *bdev, fmode_t mode)
1901 {
1902         struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk, false, 0);
1903
1904         if (!tape)
1905                 return -ENXIO;
1906
1907         return 0;
1908 }
1909
1910 static int idetape_release(struct gendisk *disk, fmode_t mode)
1911 {
1912         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1913
1914         ide_tape_put(tape);
1915         return 0;
1916 }
1917
1918 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1919                         unsigned int cmd, unsigned long arg)
1920 {
1921         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1922         ide_drive_t *drive = tape->drive;
1923         int err = generic_ide_ioctl(drive, bdev, cmd, arg);
1924         if (err == -EINVAL)
1925                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1926         return err;
1927 }
1928
1929 static struct block_device_operations idetape_block_ops = {
1930         .owner          = THIS_MODULE,
1931         .open           = idetape_open,
1932         .release        = idetape_release,
1933         .locked_ioctl   = idetape_ioctl,
1934 };
1935
1936 static int ide_tape_probe(ide_drive_t *drive)
1937 {
1938         idetape_tape_t *tape;
1939         struct gendisk *g;
1940         int minor;
1941
1942         if (!strstr("ide-tape", drive->driver_req))
1943                 goto failed;
1944
1945         if (drive->media != ide_tape)
1946                 goto failed;
1947
1948         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1949             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1950                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1951                                 " the driver\n", drive->name);
1952                 goto failed;
1953         }
1954         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1955         if (tape == NULL) {
1956                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1957                                 drive->name);
1958                 goto failed;
1959         }
1960
1961         g = alloc_disk(1 << PARTN_BITS);
1962         if (!g)
1963                 goto out_free_tape;
1964
1965         ide_init_disk(g, drive);
1966
1967         tape->dev.parent = &drive->gendev;
1968         tape->dev.release = ide_tape_release;
1969         dev_set_name(&tape->dev, dev_name(&drive->gendev));
1970
1971         if (device_register(&tape->dev))
1972                 goto out_free_disk;
1973
1974         tape->drive = drive;
1975         tape->driver = &idetape_driver;
1976         tape->disk = g;
1977
1978         g->private_data = &tape->driver;
1979
1980         drive->driver_data = tape;
1981
1982         mutex_lock(&idetape_ref_mutex);
1983         for (minor = 0; idetape_devs[minor]; minor++)
1984                 ;
1985         idetape_devs[minor] = tape;
1986         mutex_unlock(&idetape_ref_mutex);
1987
1988         idetape_setup(drive, tape, minor);
1989
1990         device_create(idetape_sysfs_class, &drive->gendev,
1991                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
1992         device_create(idetape_sysfs_class, &drive->gendev,
1993                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
1994                       "n%s", tape->name);
1995
1996         g->fops = &idetape_block_ops;
1997         ide_register_region(g);
1998
1999         return 0;
2000
2001 out_free_disk:
2002         put_disk(g);
2003 out_free_tape:
2004         kfree(tape);
2005 failed:
2006         return -ENODEV;
2007 }
2008
2009 static void __exit idetape_exit(void)
2010 {
2011         driver_unregister(&idetape_driver.gen_driver);
2012         class_destroy(idetape_sysfs_class);
2013         unregister_chrdev(IDETAPE_MAJOR, "ht");
2014 }
2015
2016 static int __init idetape_init(void)
2017 {
2018         int error = 1;
2019         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2020         if (IS_ERR(idetape_sysfs_class)) {
2021                 idetape_sysfs_class = NULL;
2022                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2023                 error = -EBUSY;
2024                 goto out;
2025         }
2026
2027         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2028                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2029                                 " interface\n");
2030                 error = -EBUSY;
2031                 goto out_free_class;
2032         }
2033
2034         error = driver_register(&idetape_driver.gen_driver);
2035         if (error)
2036                 goto out_free_driver;
2037
2038         return 0;
2039
2040 out_free_driver:
2041         driver_unregister(&idetape_driver.gen_driver);
2042 out_free_class:
2043         class_destroy(idetape_sysfs_class);
2044 out:
2045         return error;
2046 }
2047
2048 MODULE_ALIAS("ide:*m-tape*");
2049 module_init(idetape_init);
2050 module_exit(idetape_exit);
2051 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2052 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2053 MODULE_LICENSE("GPL");