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