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