drivers/ide/ide-tape.c

   1 /*
   2  * IDE ATAPI streaming tape driver.
   3  *
   4  * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
   5  * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
   6  *
   7  * This driver was constructed as a student project in the software laboratory
   8  * of the faculty of electrical engineering in the Technion - Israel's
   9  * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
  10  *
  11  * It is hereby placed under the terms of the GNU general public license.
  12  * (See linux/COPYING).
  13  *
  14  * For a historical changelog see
  15  * Documentation/ide/ChangeLog.ide-tape.1995-2002
  16  */
  17
  18 #define DRV_NAME "ide-tape"
  19
  20 #define IDETAPE_VERSION "1.20"
  21
  22 #include <linux/compat.h>
  23 #include <linux/module.h>
  24 #include <linux/types.h>
  25 #include <linux/string.h>
  26 #include <linux/kernel.h>
  27 #include <linux/delay.h>
  28 #include <linux/timer.h>
  29 #include <linux/mm.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/jiffies.h>
  32 #include <linux/major.h>
  33 #include <linux/errno.h>
  34 #include <linux/genhd.h>
  35 #include <linux/seq_file.h>
  36 #include <linux/slab.h>
  37 #include <linux/pci.h>
  38 #include <linux/ide.h>
  39 #include <linux/completion.h>
  40 #include <linux/bitops.h>
  41 #include <linux/mutex.h>
  42 #include <scsi/scsi.h>
  43
  44 #include <asm/byteorder.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(ide_tape_mutex);
 222 static DEFINE_MUTEX(idetape_ref_mutex);
 223
 224 static DEFINE_MUTEX(idetape_chrdev_mutex);
 225
 226 static struct class *idetape_sysfs_class;
 227
 228 static void ide_tape_release(struct device *);
 229
 230 static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
 231
 232 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk, bool cdev,
 233                                          unsigned int i)
 234 {
 235         struct ide_tape_obj *tape = NULL;
 236
 237         mutex_lock(&idetape_ref_mutex);
 238
 239         if (cdev)
 240                 tape = idetape_devs[i];
 241         else
 242                 tape = ide_drv_g(disk, ide_tape_obj);
 243
 244         if (tape) {
 245                 if (ide_device_get(tape->drive))
 246                         tape = NULL;
 247                 else
 248                         get_device(&tape->dev);
 249         }
 250
 251         mutex_unlock(&idetape_ref_mutex);
 252         return tape;
 253 }
 254
 255 static void ide_tape_put(struct ide_tape_obj *tape)
 256 {
 257         ide_drive_t *drive = tape->drive;
 258
 259         mutex_lock(&idetape_ref_mutex);
 260         put_device(&tape->dev);
 261         ide_device_put(drive);
 262         mutex_unlock(&idetape_ref_mutex);
 263 }
 264
 265 /*
 266  * called on each failed packet command retry to analyze the request sense. We
 267  * currently do not utilize this information.
 268  */
 269 static void idetape_analyze_error(ide_drive_t *drive)
 270 {
 271         idetape_tape_t *tape = drive->driver_data;
 272         struct ide_atapi_pc *pc = drive->failed_pc;
 273         struct request *rq = drive->hwif->rq;
 274         u8 *sense = bio_data(rq->bio);
 275
 276         tape->sense_key = sense[2] & 0xF;
 277         tape->asc       = sense[12];
 278         tape->ascq      = sense[13];
 279
 280         ide_debug_log(IDE_DBG_FUNC,
 281                       "cmd: 0x%x, sense key = %x, asc = %x, ascq = %x",
 282                       rq->cmd[0], tape->sense_key, tape->asc, tape->ascq);
 283
 284         /* correct remaining bytes to transfer */
 285         if (pc->flags & PC_FLAG_DMA_ERROR)
 286                 scsi_req(rq)->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
 287
 288         /*
 289          * If error was the result of a zero-length read or write command,
 290          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
 291          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
 292          */
 293         if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
 294             /* length == 0 */
 295             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
 296                 if (tape->sense_key == 5) {
 297                         /* don't report an error, everything's ok */
 298                         pc->error = 0;
 299                         /* don't retry read/write */
 300                         pc->flags |= PC_FLAG_ABORT;
 301                 }
 302         }
 303         if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
 304                 pc->error = IDE_DRV_ERROR_FILEMARK;
 305                 pc->flags |= PC_FLAG_ABORT;
 306         }
 307         if (pc->c[0] == WRITE_6) {
 308                 if ((sense[2] & 0x40) || (tape->sense_key == 0xd
 309                      && tape->asc == 0x0 && tape->ascq == 0x2)) {
 310                         pc->error = IDE_DRV_ERROR_EOD;
 311                         pc->flags |= PC_FLAG_ABORT;
 312                 }
 313         }
 314         if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 315                 if (tape->sense_key == 8) {
 316                         pc->error = IDE_DRV_ERROR_EOD;
 317                         pc->flags |= PC_FLAG_ABORT;
 318                 }
 319                 if (!(pc->flags & PC_FLAG_ABORT) &&
 320                     (blk_rq_bytes(rq) - scsi_req(rq)->resid_len))
 321                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
 322         }
 323 }
 324
 325 static void ide_tape_handle_dsc(ide_drive_t *);
 326
 327 static int ide_tape_callback(ide_drive_t *drive, int dsc)
 328 {
 329         idetape_tape_t *tape = drive->driver_data;
 330         struct ide_atapi_pc *pc = drive->pc;
 331         struct request *rq = drive->hwif->rq;
 332         int uptodate = pc->error ? 0 : 1;
 333         int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 334
 335         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc: %d, err: %d", rq->cmd[0],
 336                       dsc, err);
 337
 338         if (dsc)
 339                 ide_tape_handle_dsc(drive);
 340
 341         if (drive->failed_pc == pc)
 342                 drive->failed_pc = NULL;
 343
 344         if (pc->c[0] == REQUEST_SENSE) {
 345                 if (uptodate)
 346                         idetape_analyze_error(drive);
 347                 else
 348                         printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
 349                                         "itself - Aborting request!\n");
 350         } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 351                 unsigned int blocks =
 352                         (blk_rq_bytes(rq) - scsi_req(rq)->resid_len) / tape->blk_size;
 353
 354                 tape->avg_size += blocks * tape->blk_size;
 355
 356                 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
 357                         tape->avg_speed = tape->avg_size * HZ /
 358                                 (jiffies - tape->avg_time) / 1024;
 359                         tape->avg_size = 0;
 360                         tape->avg_time = jiffies;
 361                 }
 362
 363                 tape->first_frame += blocks;
 364
 365                 if (pc->error) {
 366                         uptodate = 0;
 367                         err = pc->error;
 368                 }
 369         }
 370         scsi_req(rq)->result = err;
 371
 372         return uptodate;
 373 }
 374
 375 /*
 376  * Postpone the current request so that ide.c will be able to service requests
 377  * from another device on the same port while we are polling for DSC.
 378  */
 379 static void ide_tape_stall_queue(ide_drive_t *drive)
 380 {
 381         idetape_tape_t *tape = drive->driver_data;
 382
 383         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc_poll_freq: %lu",
 384                       drive->hwif->rq->cmd[0], tape->dsc_poll_freq);
 385
 386         tape->postponed_rq = true;
 387
 388         ide_stall_queue(drive, tape->dsc_poll_freq);
 389 }
 390
 391 static void ide_tape_handle_dsc(ide_drive_t *drive)
 392 {
 393         idetape_tape_t *tape = drive->driver_data;
 394
 395         /* Media access command */
 396         tape->dsc_polling_start = jiffies;
 397         tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
 398         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
 399         /* Allow ide.c to handle other requests */
 400         ide_tape_stall_queue(drive);
 401 }
 402
 403 /*
 404  * Packet Command Interface
 405  *
 406  * The current Packet Command is available in drive->pc, and will not change
 407  * until we finish handling it. Each packet command is associated with a
 408  * callback function that will be called when the command is finished.
 409  *
 410  * The handling will be done in three stages:
 411  *
 412  * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
 413  * the interrupt handler to ide_pc_intr.
 414  *
 415  * 2. On each interrupt, ide_pc_intr will be called. This step will be
 416  * repeated until the device signals us that no more interrupts will be issued.
 417  *
 418  * 3. ATAPI Tape media access commands have immediate status with a delayed
 419  * process. In case of a successful initiation of a media access packet command,
 420  * the DSC bit will be set when the actual execution of the command is finished.
 421  * Since the tape drive will not issue an interrupt, we have to poll for this
 422  * event. In this case, we define the request as "low priority request" by
 423  * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 424  * exit the driver.
 425  *
 426  * ide.c will then give higher priority to requests which originate from the
 427  * other device, until will change rq_status to RQ_ACTIVE.
 428  *
 429  * 4. When the packet command is finished, it will be checked for errors.
 430  *
 431  * 5. In case an error was found, we queue a request sense packet command in
 432  * front of the request queue and retry the operation up to
 433  * IDETAPE_MAX_PC_RETRIES times.
 434  *
 435  * 6. In case no error was found, or we decided to give up and not to retry
 436  * again, the callback function will be called and then we will handle the next
 437  * request.
 438  */
 439
 440 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 441                                          struct ide_cmd *cmd,
 442                                          struct ide_atapi_pc *pc)
 443 {
 444         idetape_tape_t *tape = drive->driver_data;
 445         struct request *rq = drive->hwif->rq;
 446
 447         if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
 448                 drive->failed_pc = pc;
 449
 450         /* Set the current packet command */
 451         drive->pc = pc;
 452
 453         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
 454                 (pc->flags & PC_FLAG_ABORT)) {
 455
 456                 /*
 457                  * We will "abort" retrying a packet command in case legitimate
 458                  * error code was received (crossing a filemark, or end of the
 459                  * media, for example).
 460                  */
 461                 if (!(pc->flags & PC_FLAG_ABORT)) {
 462                         if (!(pc->c[0] == TEST_UNIT_READY &&
 463                               tape->sense_key == 2 && tape->asc == 4 &&
 464                              (tape->ascq == 1 || tape->ascq == 8))) {
 465                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
 466                                                 "pc = %2x, key = %2x, "
 467                                                 "asc = %2x, ascq = %2x\n",
 468                                                 tape->name, pc->c[0],
 469                                                 tape->sense_key, tape->asc,
 470                                                 tape->ascq);
 471                         }
 472                         /* Giving up */
 473                         pc->error = IDE_DRV_ERROR_GENERAL;
 474                 }
 475
 476                 drive->failed_pc = NULL;
 477                 drive->pc_callback(drive, 0);
 478                 ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(rq));
 479                 return ide_stopped;
 480         }
 481         ide_debug_log(IDE_DBG_SENSE, "retry #%d, cmd: 0x%02x", pc->retries,
 482                       pc->c[0]);
 483
 484         pc->retries++;
 485
 486         return ide_issue_pc(drive, cmd);
 487 }
 488
 489 /* A mode sense command is used to "sense" tape parameters. */
 490 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 491 {
 492         ide_init_pc(pc);
 493         pc->c[0] = MODE_SENSE;
 494         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
 495                 /* DBD = 1 - Don't return block descriptors */
 496                 pc->c[1] = 8;
 497         pc->c[2] = page_code;
 498         /*
 499          * Changed pc->c[3] to 0 (255 will at best return unused info).
 500          *
 501          * For SCSI this byte is defined as subpage instead of high byte
 502          * of length and some IDE drives seem to interpret it this way
 503          * and return an error when 255 is used.
 504          */
 505         pc->c[3] = 0;
 506         /* We will just discard data in that case */
 507         pc->c[4] = 255;
 508         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
 509                 pc->req_xfer = 12;
 510         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
 511                 pc->req_xfer = 24;
 512         else
 513                 pc->req_xfer = 50;
 514 }
 515
 516 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 517 {
 518         ide_hwif_t *hwif = drive->hwif;
 519         idetape_tape_t *tape = drive->driver_data;
 520         struct ide_atapi_pc *pc = drive->pc;
 521         u8 stat;
 522
 523         stat = hwif->tp_ops->read_status(hwif);
 524
 525         if (stat & ATA_DSC) {
 526                 if (stat & ATA_ERR) {
 527                         /* Error detected */
 528                         if (pc->c[0] != TEST_UNIT_READY)
 529                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
 530                                                 tape->name);
 531                         /* Retry operation */
 532                         ide_retry_pc(drive);
 533                         return ide_stopped;
 534                 }
 535                 pc->error = 0;
 536         } else {
 537                 pc->error = IDE_DRV_ERROR_GENERAL;
 538                 drive->failed_pc = NULL;
 539         }
 540         drive->pc_callback(drive, 0);
 541         return ide_stopped;
 542 }
 543
 544 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
 545                                    struct ide_atapi_pc *pc, struct request *rq,
 546                                    u8 opcode)
 547 {
 548         unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
 549
 550         ide_init_pc(pc);
 551         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
 552         pc->c[1] = 1;
 553
 554         if (blk_rq_bytes(rq) == tape->buffer_size)
 555                 pc->flags |= PC_FLAG_DMA_OK;
 556
 557         if (opcode == READ_6)
 558                 pc->c[0] = READ_6;
 559         else if (opcode == WRITE_6) {
 560                 pc->c[0] = WRITE_6;
 561                 pc->flags |= PC_FLAG_WRITING;
 562         }
 563
 564         memcpy(scsi_req(rq)->cmd, pc->c, 12);
 565 }
 566
 567 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 568                                           struct request *rq, sector_t block)
 569 {
 570         ide_hwif_t *hwif = drive->hwif;
 571         idetape_tape_t *tape = drive->driver_data;
 572         struct ide_atapi_pc *pc = NULL;
 573         struct ide_cmd cmd;
 574         struct scsi_request *req = scsi_req(rq);
 575         u8 stat;
 576
 577         ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, sector: %llu, nr_sectors: %u",
 578                       req->cmd[0], (unsigned long long)blk_rq_pos(rq),
 579                       blk_rq_sectors(rq));
 580
 581         BUG_ON(!blk_rq_is_private(rq));
 582         BUG_ON(ide_req(rq)->type != ATA_PRIV_MISC &&
 583                ide_req(rq)->type != ATA_PRIV_SENSE);
 584
 585         /* Retry a failed packet command */
 586         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 587                 pc = drive->failed_pc;
 588                 goto out;
 589         }
 590
 591         /*
 592          * If the tape is still busy, postpone our request and service
 593          * the other device meanwhile.
 594          */
 595         stat = hwif->tp_ops->read_status(hwif);
 596
 597         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 598             (req->cmd[13] & REQ_IDETAPE_PC2) == 0)
 599                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 600
 601         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 602                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 603                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 604         }
 605
 606         if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
 607             !(stat & ATA_DSC)) {
 608                 if (!tape->postponed_rq) {
 609                         tape->dsc_polling_start = jiffies;
 610                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 611                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 612                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 613                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 614                                 tape->name);
 615                         if (req->cmd[13] & REQ_IDETAPE_PC2) {
 616                                 idetape_media_access_finished(drive);
 617                                 return ide_stopped;
 618                         } else {
 619                                 return ide_do_reset(drive);
 620                         }
 621                 } else if (time_after(jiffies,
 622                                         tape->dsc_polling_start +
 623                                         IDETAPE_DSC_MA_THRESHOLD))
 624                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 625                 ide_tape_stall_queue(drive);
 626                 return ide_stopped;
 627         } else {
 628                 drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
 629                 tape->postponed_rq = false;
 630         }
 631
 632         if (req->cmd[13] & REQ_IDETAPE_READ) {
 633                 pc = &tape->queued_pc;
 634                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 635                 goto out;
 636         }
 637         if (req->cmd[13] & REQ_IDETAPE_WRITE) {
 638                 pc = &tape->queued_pc;
 639                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 640                 goto out;
 641         }
 642         if (req->cmd[13] & REQ_IDETAPE_PC1) {
 643                 pc = (struct ide_atapi_pc *)ide_req(rq)->special;
 644                 req->cmd[13] &= ~(REQ_IDETAPE_PC1);
 645                 req->cmd[13] |= REQ_IDETAPE_PC2;
 646                 goto out;
 647         }
 648         if (req->cmd[13] & REQ_IDETAPE_PC2) {
 649                 idetape_media_access_finished(drive);
 650                 return ide_stopped;
 651         }
 652         BUG();
 653
 654 out:
 655         /* prepare sense request for this command */
 656         ide_prep_sense(drive, rq);
 657
 658         memset(&cmd, 0, sizeof(cmd));
 659
 660         if (rq_data_dir(rq))
 661                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 662
 663         cmd.rq = rq;
 664
 665         ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
 666         ide_map_sg(drive, &cmd);
 667
 668         return ide_tape_issue_pc(drive, &cmd, pc);
 669 }
 670
 671 /*
 672  * Write a filemark if write_filemark=1. Flush the device buffers without
 673  * writing a filemark otherwise.
 674  */
 675 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 676                 struct ide_atapi_pc *pc, int write_filemark)
 677 {
 678         ide_init_pc(pc);
 679         pc->c[0] = WRITE_FILEMARKS;
 680         pc->c[4] = write_filemark;
 681         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 682 }
 683
 684 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 685 {
 686         idetape_tape_t *tape = drive->driver_data;
 687         struct gendisk *disk = tape->disk;
 688         int load_attempted = 0;
 689
 690         /* Wait for the tape to become ready */
 691         set_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT), &drive->atapi_flags);
 692         timeout += jiffies;
 693         while (time_before(jiffies, timeout)) {
 694                 if (ide_do_test_unit_ready(drive, disk) == 0)
 695                         return 0;
 696                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 697                     || (tape->asc == 0x3A)) {
 698                         /* no media */
 699                         if (load_attempted)
 700                                 return -ENOMEDIUM;
 701                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 702                         load_attempted = 1;
 703                 /* not about to be ready */
 704                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 705                              (tape->ascq == 1 || tape->ascq == 8)))
 706                         return -EIO;
 707                 msleep(100);
 708         }
 709         return -EIO;
 710 }
 711
 712 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 713 {
 714         struct ide_tape_obj *tape = drive->driver_data;
 715         struct ide_atapi_pc pc;
 716         int rc;
 717
 718         idetape_create_write_filemark_cmd(drive, &pc, 0);
 719         rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
 720         if (rc)
 721                 return rc;
 722         idetape_wait_ready(drive, 60 * 5 * HZ);
 723         return 0;
 724 }
 725
 726 static int ide_tape_read_position(ide_drive_t *drive)
 727 {
 728         idetape_tape_t *tape = drive->driver_data;
 729         struct ide_atapi_pc pc;
 730         u8 buf[20];
 731
 732         ide_debug_log(IDE_DBG_FUNC, "enter");
 733
 734         /* prep cmd */
 735         ide_init_pc(&pc);
 736         pc.c[0] = READ_POSITION;
 737         pc.req_xfer = 20;
 738
 739         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
 740                 return -1;
 741
 742         if (!pc.error) {
 743                 ide_debug_log(IDE_DBG_FUNC, "BOP - %s",
 744                                 (buf[0] & 0x80) ? "Yes" : "No");
 745                 ide_debug_log(IDE_DBG_FUNC, "EOP - %s",
 746                                 (buf[0] & 0x40) ? "Yes" : "No");
 747
 748                 if (buf[0] & 0x4) {
 749                         printk(KERN_INFO "ide-tape: Block location is unknown"
 750                                          "to the tape\n");
 751                         clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 752                                   &drive->atapi_flags);
 753                         return -1;
 754                 } else {
 755                         ide_debug_log(IDE_DBG_FUNC, "Block Location: %u",
 756                                       be32_to_cpup((__be32 *)&buf[4]));
 757
 758                         tape->partition = buf[1];
 759                         tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
 760                         set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 761                                 &drive->atapi_flags);
 762                 }
 763         }
 764
 765         return tape->first_frame;
 766 }
 767
 768 static void idetape_create_locate_cmd(ide_drive_t *drive,
 769                 struct ide_atapi_pc *pc,
 770                 unsigned int block, u8 partition, int skip)
 771 {
 772         ide_init_pc(pc);
 773         pc->c[0] = POSITION_TO_ELEMENT;
 774         pc->c[1] = 2;
 775         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 776         pc->c[8] = partition;
 777         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 778 }
 779
 780 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 781 {
 782         idetape_tape_t *tape = drive->driver_data;
 783
 784         if (tape->chrdev_dir != IDETAPE_DIR_READ)
 785                 return;
 786
 787         clear_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
 788         tape->valid = 0;
 789         if (tape->buf != NULL) {
 790                 kfree(tape->buf);
 791                 tape->buf = NULL;
 792         }
 793
 794         tape->chrdev_dir = IDETAPE_DIR_NONE;
 795 }
 796
 797 /*
 798  * Position the tape to the requested block using the LOCATE packet command.
 799  * A READ POSITION command is then issued to check where we are positioned. Like
 800  * all higher level operations, we queue the commands at the tail of the request
 801  * queue and wait for their completion.
 802  */
 803 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 804                 u8 partition, int skip)
 805 {
 806         idetape_tape_t *tape = drive->driver_data;
 807         struct gendisk *disk = tape->disk;
 808         int ret;
 809         struct ide_atapi_pc pc;
 810
 811         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 812                 __ide_tape_discard_merge_buffer(drive);
 813         idetape_wait_ready(drive, 60 * 5 * HZ);
 814         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 815         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 816         if (ret)
 817                 return ret;
 818
 819         ret = ide_tape_read_position(drive);
 820         if (ret < 0)
 821                 return ret;
 822         return 0;
 823 }
 824
 825 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 826                                           int restore_position)
 827 {
 828         idetape_tape_t *tape = drive->driver_data;
 829         int seek, position;
 830
 831         __ide_tape_discard_merge_buffer(drive);
 832         if (restore_position) {
 833                 position = ide_tape_read_position(drive);
 834                 seek = position > 0 ? position : 0;
 835                 if (idetape_position_tape(drive, seek, 0, 0)) {
 836                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 837                                          " %s\n", tape->name, __func__);
 838                         return;
 839                 }
 840         }
 841 }
 842
 843 /*
 844  * Generate a read/write request for the block device interface and wait for it
 845  * to be serviced.
 846  */
 847 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 848 {
 849         idetape_tape_t *tape = drive->driver_data;
 850         struct request *rq;
 851         int ret;
 852
 853         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, size: %d", cmd, size);
 854
 855         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 856         BUG_ON(size < 0 || size % tape->blk_size);
 857
 858         rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
 859         ide_req(rq)->type = ATA_PRIV_MISC;
 860         scsi_req(rq)->cmd[13] = cmd;
 861         rq->rq_disk = tape->disk;
 862         rq->__sector = tape->first_frame;
 863
 864         if (size) {
 865                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 866                                       GFP_NOIO);
 867                 if (ret)
 868                         goto out_put;
 869         }
 870
 871         blk_execute_rq(tape->disk, rq, 0);
 872
 873         /* calculate the number of transferred bytes and update buffer state */
 874         size -= scsi_req(rq)->resid_len;
 875         tape->cur = tape->buf;
 876         if (cmd == REQ_IDETAPE_READ)
 877                 tape->valid = size;
 878         else
 879                 tape->valid = 0;
 880
 881         ret = size;
 882         if (scsi_req(rq)->result == IDE_DRV_ERROR_GENERAL)
 883                 ret = -EIO;
 884 out_put:
 885         blk_put_request(rq);
 886         return ret;
 887 }
 888
 889 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 890 {
 891         ide_init_pc(pc);
 892         pc->c[0] = INQUIRY;
 893         pc->c[4] = 254;
 894         pc->req_xfer = 254;
 895 }
 896
 897 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 898                 struct ide_atapi_pc *pc)
 899 {
 900         ide_init_pc(pc);
 901         pc->c[0] = REZERO_UNIT;
 902         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 903 }
 904
 905 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 906 {
 907         ide_init_pc(pc);
 908         pc->c[0] = ERASE;
 909         pc->c[1] = 1;
 910         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 911 }
 912
 913 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 914 {
 915         ide_init_pc(pc);
 916         pc->c[0] = SPACE;
 917         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 918         pc->c[1] = cmd;
 919         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 920 }
 921
 922 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 923 {
 924         idetape_tape_t *tape = drive->driver_data;
 925
 926         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 927                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 928                                 " but we are not writing.\n");
 929                 return;
 930         }
 931         if (tape->buf) {
 932                 size_t aligned = roundup(tape->valid, tape->blk_size);
 933
 934                 memset(tape->cur, 0, aligned - tape->valid);
 935                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 936                 kfree(tape->buf);
 937                 tape->buf = NULL;
 938         }
 939         tape->chrdev_dir = IDETAPE_DIR_NONE;
 940 }
 941
 942 static int idetape_init_rw(ide_drive_t *drive, int dir)
 943 {
 944         idetape_tape_t *tape = drive->driver_data;
 945         int rc;
 946
 947         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 948
 949         if (tape->chrdev_dir == dir)
 950                 return 0;
 951
 952         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 953                 ide_tape_discard_merge_buffer(drive, 1);
 954         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 955                 ide_tape_flush_merge_buffer(drive);
 956                 idetape_flush_tape_buffers(drive);
 957         }
 958
 959         if (tape->buf || tape->valid) {
 960                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 961                 tape->valid = 0;
 962         }
 963
 964         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 965         if (!tape->buf)
 966                 return -ENOMEM;
 967         tape->chrdev_dir = dir;
 968         tape->cur = tape->buf;
 969
 970         /*
 971          * Issue a 0 rw command to ensure that DSC handshake is
 972          * switched from completion mode to buffer available mode.  No
 973          * point in issuing this if DSC overlap isn't supported, some
 974          * drives (Seagate STT3401A) will return an error.
 975          */
 976         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
 977                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
 978                                                   : REQ_IDETAPE_WRITE;
 979
 980                 rc = idetape_queue_rw_tail(drive, cmd, 0);
 981                 if (rc < 0) {
 982                         kfree(tape->buf);
 983                         tape->buf = NULL;
 984                         tape->chrdev_dir = IDETAPE_DIR_NONE;
 985                         return rc;
 986                 }
 987         }
 988
 989         return 0;
 990 }
 991
 992 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
 993 {
 994         idetape_tape_t *tape = drive->driver_data;
 995
 996         memset(tape->buf, 0, tape->buffer_size);
 997
 998         while (bcount) {
 999                 unsigned int count = min(tape->buffer_size, bcount);
1000
1001                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1002                 bcount -= count;
1003         }
1004 }
1005
1006 /*
1007  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1008  * currently support only one partition.
1009  */
1010 static int idetape_rewind_tape(ide_drive_t *drive)
1011 {
1012         struct ide_tape_obj *tape = drive->driver_data;
1013         struct gendisk *disk = tape->disk;
1014         struct ide_atapi_pc pc;
1015         int ret;
1016
1017         ide_debug_log(IDE_DBG_FUNC, "enter");
1018
1019         idetape_create_rewind_cmd(drive, &pc);
1020         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1021         if (ret)
1022                 return ret;
1023
1024         ret = ide_tape_read_position(drive);
1025         if (ret < 0)
1026                 return ret;
1027         return 0;
1028 }
1029
1030 /* mtio.h compatible commands should be issued to the chrdev interface. */
1031 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1032                                 unsigned long arg)
1033 {
1034         idetape_tape_t *tape = drive->driver_data;
1035         void __user *argp = (void __user *)arg;
1036
1037         struct idetape_config {
1038                 int dsc_rw_frequency;
1039                 int dsc_media_access_frequency;
1040                 int nr_stages;
1041         } config;
1042
1043         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%04x", cmd);
1044
1045         switch (cmd) {
1046         case 0x0340:
1047                 if (copy_from_user(&config, argp, sizeof(config)))
1048                         return -EFAULT;
1049                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1050                 break;
1051         case 0x0350:
1052                 memset(&config, 0, sizeof(config));
1053                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1054                 config.nr_stages = 1;
1055                 if (copy_to_user(argp, &config, sizeof(config)))
1056                         return -EFAULT;
1057                 break;
1058         default:
1059                 return -EIO;
1060         }
1061         return 0;
1062 }
1063
1064 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1065                                         int mt_count)
1066 {
1067         idetape_tape_t *tape = drive->driver_data;
1068         struct gendisk *disk = tape->disk;
1069         struct ide_atapi_pc pc;
1070         int retval, count = 0;
1071         int sprev = !!(tape->caps[4] & 0x20);
1072
1073
1074         ide_debug_log(IDE_DBG_FUNC, "mt_op: %d, mt_count: %d", mt_op, mt_count);
1075
1076         if (mt_count == 0)
1077                 return 0;
1078         if (MTBSF == mt_op || MTBSFM == mt_op) {
1079                 if (!sprev)
1080                         return -EIO;
1081                 mt_count = -mt_count;
1082         }
1083
1084         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1085                 tape->valid = 0;
1086                 if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1087                                        &drive->atapi_flags))
1088                         ++count;
1089                 ide_tape_discard_merge_buffer(drive, 0);
1090         }
1091
1092         switch (mt_op) {
1093         case MTFSF:
1094         case MTBSF:
1095                 idetape_create_space_cmd(&pc, mt_count - count,
1096                                          IDETAPE_SPACE_OVER_FILEMARK);
1097                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1098         case MTFSFM:
1099         case MTBSFM:
1100                 if (!sprev)
1101                         return -EIO;
1102                 retval = idetape_space_over_filemarks(drive, MTFSF,
1103                                                       mt_count - count);
1104                 if (retval)
1105                         return retval;
1106                 count = (MTBSFM == mt_op ? 1 : -1);
1107                 return idetape_space_over_filemarks(drive, MTFSF, count);
1108         default:
1109                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1110                                 mt_op);
1111                 return -EIO;
1112         }
1113 }
1114
1115 /*
1116  * Our character device read / write functions.
1117  *
1118  * The tape is optimized to maximize throughput when it is transferring an
1119  * integral number of the "continuous transfer limit", which is a parameter of
1120  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1121  *
1122  * As of version 1.3 of the driver, the character device provides an abstract
1123  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1124  * same backup/restore procedure is supported. The driver will internally
1125  * convert the requests to the recommended transfer unit, so that an unmatch
1126  * between the user's block size to the recommended size will only result in a
1127  * (slightly) increased driver overhead, but will no longer hit performance.
1128  * This is not applicable to Onstream.
1129  */
1130 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1131                                    size_t count, loff_t *ppos)
1132 {
1133         struct ide_tape_obj *tape = file->private_data;
1134         ide_drive_t *drive = tape->drive;
1135         size_t done = 0;
1136         ssize_t ret = 0;
1137         int rc;
1138
1139         ide_debug_log(IDE_DBG_FUNC, "count %zd", count);
1140
1141         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1142                 if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1143                         if (count > tape->blk_size &&
1144                             (count % tape->blk_size) == 0)
1145                                 tape->user_bs_factor = count / tape->blk_size;
1146         }
1147
1148         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1149         if (rc < 0)
1150                 return rc;
1151
1152         while (done < count) {
1153                 size_t todo;
1154
1155                 /* refill if staging buffer is empty */
1156                 if (!tape->valid) {
1157                         /* If we are at a filemark, nothing more to read */
1158                         if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1159                                      &drive->atapi_flags))
1160                                 break;
1161                         /* read */
1162                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1163                                                   tape->buffer_size) <= 0)
1164                                 break;
1165                 }
1166
1167                 /* copy out */
1168                 todo = min_t(size_t, count - done, tape->valid);
1169                 if (copy_to_user(buf + done, tape->cur, todo))
1170                         ret = -EFAULT;
1171
1172                 tape->cur += todo;
1173                 tape->valid -= todo;
1174                 done += todo;
1175         }
1176
1177         if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1178                 idetape_space_over_filemarks(drive, MTFSF, 1);
1179                 return 0;
1180         }
1181
1182         return ret ? ret : done;
1183 }
1184
1185 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1186                                      size_t count, loff_t *ppos)
1187 {
1188         struct ide_tape_obj *tape = file->private_data;
1189         ide_drive_t *drive = tape->drive;
1190         size_t done = 0;
1191         ssize_t ret = 0;
1192         int rc;
1193
1194         /* The drive is write protected. */
1195         if (tape->write_prot)
1196                 return -EACCES;
1197
1198         ide_debug_log(IDE_DBG_FUNC, "count %zd", count);
1199
1200         /* Initialize write operation */
1201         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1202         if (rc < 0)
1203                 return rc;
1204
1205         while (done < count) {
1206                 size_t todo;
1207
1208                 /* flush if staging buffer is full */
1209                 if (tape->valid == tape->buffer_size &&
1210                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1211                                           tape->buffer_size) <= 0)
1212                         return rc;
1213
1214                 /* copy in */
1215                 todo = min_t(size_t, count - done,
1216                              tape->buffer_size - tape->valid);
1217                 if (copy_from_user(tape->cur, buf + done, todo))
1218                         ret = -EFAULT;
1219
1220                 tape->cur += todo;
1221                 tape->valid += todo;
1222                 done += todo;
1223         }
1224
1225         return ret ? ret : done;
1226 }
1227
1228 static int idetape_write_filemark(ide_drive_t *drive)
1229 {
1230         struct ide_tape_obj *tape = drive->driver_data;
1231         struct ide_atapi_pc pc;
1232
1233         /* Write a filemark */
1234         idetape_create_write_filemark_cmd(drive, &pc, 1);
1235         if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1236                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1237                 return -EIO;
1238         }
1239         return 0;
1240 }
1241
1242 /*
1243  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1244  * requested.
1245  *
1246  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1247  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1248  * usually not supported.
1249  *
1250  * The following commands are currently not supported:
1251  *
1252  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1253  * MT_ST_WRITE_THRESHOLD.
1254  */
1255 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1256 {
1257         idetape_tape_t *tape = drive->driver_data;
1258         struct gendisk *disk = tape->disk;
1259         struct ide_atapi_pc pc;
1260         int i, retval;
1261
1262         ide_debug_log(IDE_DBG_FUNC, "MTIOCTOP ioctl: mt_op: %d, mt_count: %d",
1263                       mt_op, mt_count);
1264
1265         switch (mt_op) {
1266         case MTFSF:
1267         case MTFSFM:
1268         case MTBSF:
1269         case MTBSFM:
1270                 if (!mt_count)
1271                         return 0;
1272                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1273         default:
1274                 break;
1275         }
1276
1277         switch (mt_op) {
1278         case MTWEOF:
1279                 if (tape->write_prot)
1280                         return -EACCES;
1281                 ide_tape_discard_merge_buffer(drive, 1);
1282                 for (i = 0; i < mt_count; i++) {
1283                         retval = idetape_write_filemark(drive);
1284                         if (retval)
1285                                 return retval;
1286                 }
1287                 return 0;
1288         case MTREW:
1289                 ide_tape_discard_merge_buffer(drive, 0);
1290                 if (idetape_rewind_tape(drive))
1291                         return -EIO;
1292                 return 0;
1293         case MTLOAD:
1294                 ide_tape_discard_merge_buffer(drive, 0);
1295                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1296         case MTUNLOAD:
1297         case MTOFFL:
1298                 /*
1299                  * If door is locked, attempt to unlock before
1300                  * attempting to eject.
1301                  */
1302                 if (tape->door_locked) {
1303                         if (!ide_set_media_lock(drive, disk, 0))
1304                                 tape->door_locked = DOOR_UNLOCKED;
1305                 }
1306                 ide_tape_discard_merge_buffer(drive, 0);
1307                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1308                 if (!retval)
1309                         clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1310                                   &drive->atapi_flags);
1311                 return retval;
1312         case MTNOP:
1313                 ide_tape_discard_merge_buffer(drive, 0);
1314                 return idetape_flush_tape_buffers(drive);
1315         case MTRETEN:
1316                 ide_tape_discard_merge_buffer(drive, 0);
1317                 return ide_do_start_stop(drive, disk,
1318                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1319         case MTEOM:
1320                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1321                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1322         case MTERASE:
1323                 (void)idetape_rewind_tape(drive);
1324                 idetape_create_erase_cmd(&pc);
1325                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1326         case MTSETBLK:
1327                 if (mt_count) {
1328                         if (mt_count < tape->blk_size ||
1329                             mt_count % tape->blk_size)
1330                                 return -EIO;
1331                         tape->user_bs_factor = mt_count / tape->blk_size;
1332                         clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1333                                   &drive->atapi_flags);
1334                 } else
1335                         set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1336                                 &drive->atapi_flags);
1337                 return 0;
1338         case MTSEEK:
1339                 ide_tape_discard_merge_buffer(drive, 0);
1340                 return idetape_position_tape(drive,
1341                         mt_count * tape->user_bs_factor, tape->partition, 0);
1342         case MTSETPART:
1343                 ide_tape_discard_merge_buffer(drive, 0);
1344                 return idetape_position_tape(drive, 0, mt_count, 0);
1345         case MTFSR:
1346         case MTBSR:
1347         case MTLOCK:
1348                 retval = ide_set_media_lock(drive, disk, 1);
1349                 if (retval)
1350                         return retval;
1351                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1352                 return 0;
1353         case MTUNLOCK:
1354                 retval = ide_set_media_lock(drive, disk, 0);
1355                 if (retval)
1356                         return retval;
1357                 tape->door_locked = DOOR_UNLOCKED;
1358                 return 0;
1359         default:
1360                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1361                                 mt_op);
1362                 return -EIO;
1363         }
1364 }
1365
1366 /*
1367  * Our character device ioctls. General mtio.h magnetic io commands are
1368  * supported here, and not in the corresponding block interface. Our own
1369  * ide-tape ioctls are supported on both interfaces.
1370  */
1371 static long do_idetape_chrdev_ioctl(struct file *file,
1372                                 unsigned int cmd, unsigned long arg)
1373 {
1374         struct ide_tape_obj *tape = file->private_data;
1375         ide_drive_t *drive = tape->drive;
1376         struct mtop mtop;
1377         struct mtget mtget;
1378         struct mtpos mtpos;
1379         int block_offset = 0, position = tape->first_frame;
1380         void __user *argp = (void __user *)arg;
1381
1382         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x", cmd);
1383
1384         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1385                 ide_tape_flush_merge_buffer(drive);
1386                 idetape_flush_tape_buffers(drive);
1387         }
1388         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1389                 block_offset = tape->valid /
1390                         (tape->blk_size * tape->user_bs_factor);
1391                 position = ide_tape_read_position(drive);
1392                 if (position < 0)
1393                         return -EIO;
1394         }
1395         switch (cmd) {
1396         case MTIOCTOP:
1397                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1398                         return -EFAULT;
1399                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1400         case MTIOCGET:
1401                 memset(&mtget, 0, sizeof(struct mtget));
1402                 mtget.mt_type = MT_ISSCSI2;
1403                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1404                 mtget.mt_dsreg =
1405                         ((tape->blk_size * tape->user_bs_factor)
1406                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1407
1408                 if (tape->drv_write_prot)
1409                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1410
1411                 return put_user_mtget(argp, &mtget);
1412         case MTIOCPOS:
1413                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1414                 return put_user_mtpos(argp, &mtpos);
1415         default:
1416                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1417                         ide_tape_discard_merge_buffer(drive, 1);
1418                 return idetape_blkdev_ioctl(drive, cmd, arg);
1419         }
1420 }
1421
1422 static long idetape_chrdev_ioctl(struct file *file,
1423                                 unsigned int cmd, unsigned long arg)
1424 {
1425         long ret;
1426         mutex_lock(&ide_tape_mutex);
1427         ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1428         mutex_unlock(&ide_tape_mutex);
1429         return ret;
1430 }
1431
1432 static long idetape_chrdev_compat_ioctl(struct file *file,
1433                                 unsigned int cmd, unsigned long arg)
1434 {
1435         long ret;
1436
1437         if (cmd == MTIOCPOS32)
1438                 cmd = MTIOCPOS;
1439         else if (cmd == MTIOCGET32)
1440                 cmd = MTIOCGET;
1441
1442         mutex_lock(&ide_tape_mutex);
1443         ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1444         mutex_unlock(&ide_tape_mutex);
1445         return ret;
1446 }
1447
1448 /*
1449  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1450  * block size with the reported value.
1451  */
1452 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1453 {
1454         idetape_tape_t *tape = drive->driver_data;
1455         struct ide_atapi_pc pc;
1456         u8 buf[12];
1457
1458         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1459         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1460                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1461                 if (tape->blk_size == 0) {
1462                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1463                                             "block size, assuming 32k\n");
1464                         tape->blk_size = 32768;
1465                 }
1466                 return;
1467         }
1468         tape->blk_size = (buf[4 + 5] << 16) +
1469                                 (buf[4 + 6] << 8)  +
1470                                  buf[4 + 7];
1471         tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1472
1473         ide_debug_log(IDE_DBG_FUNC, "blk_size: %d, write_prot: %d",
1474                       tape->blk_size, tape->drv_write_prot);
1475 }
1476
1477 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1478 {
1479         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1480         ide_drive_t *drive;
1481         idetape_tape_t *tape;
1482         int retval;
1483
1484         if (i >= MAX_HWIFS * MAX_DRIVES)
1485                 return -ENXIO;
1486
1487         mutex_lock(&idetape_chrdev_mutex);
1488
1489         tape = ide_tape_get(NULL, true, i);
1490         if (!tape) {
1491                 mutex_unlock(&idetape_chrdev_mutex);
1492                 return -ENXIO;
1493         }
1494
1495         drive = tape->drive;
1496         filp->private_data = tape;
1497
1498         ide_debug_log(IDE_DBG_FUNC, "enter");
1499
1500         /*
1501          * We really want to do nonseekable_open(inode, filp); here, but some
1502          * versions of tar incorrectly call lseek on tapes and bail out if that
1503          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1504          */
1505         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1506
1507
1508         if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1509                 retval = -EBUSY;
1510                 goto out_put_tape;
1511         }
1512
1513         retval = idetape_wait_ready(drive, 60 * HZ);
1514         if (retval) {
1515                 clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1516                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1517                 goto out_put_tape;
1518         }
1519
1520         ide_tape_read_position(drive);
1521         if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1522                 (void)idetape_rewind_tape(drive);
1523
1524         /* Read block size and write protect status from drive. */
1525         ide_tape_get_bsize_from_bdesc(drive);
1526
1527         /* Set write protect flag if device is opened as read-only. */
1528         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1529                 tape->write_prot = 1;
1530         else
1531                 tape->write_prot = tape->drv_write_prot;
1532
1533         /* Make sure drive isn't write protected if user wants to write. */
1534         if (tape->write_prot) {
1535                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1536                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1537                         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1538                         retval = -EROFS;
1539                         goto out_put_tape;
1540                 }
1541         }
1542
1543         /* Lock the tape drive door so user can't eject. */
1544         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1545                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1546                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1547                                 tape->door_locked = DOOR_LOCKED;
1548                 }
1549         }
1550         mutex_unlock(&idetape_chrdev_mutex);
1551
1552         return 0;
1553
1554 out_put_tape:
1555         ide_tape_put(tape);
1556
1557         mutex_unlock(&idetape_chrdev_mutex);
1558
1559         return retval;
1560 }
1561
1562 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1563 {
1564         idetape_tape_t *tape = drive->driver_data;
1565
1566         ide_tape_flush_merge_buffer(drive);
1567         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1568         if (tape->buf != NULL) {
1569                 idetape_pad_zeros(drive, tape->blk_size *
1570                                 (tape->user_bs_factor - 1));
1571                 kfree(tape->buf);
1572                 tape->buf = NULL;
1573         }
1574         idetape_write_filemark(drive);
1575         idetape_flush_tape_buffers(drive);
1576         idetape_flush_tape_buffers(drive);
1577 }
1578
1579 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1580 {
1581         struct ide_tape_obj *tape = filp->private_data;
1582         ide_drive_t *drive = tape->drive;
1583         unsigned int minor = iminor(inode);
1584
1585         mutex_lock(&idetape_chrdev_mutex);
1586
1587         tape = drive->driver_data;
1588
1589         ide_debug_log(IDE_DBG_FUNC, "enter");
1590
1591         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1592                 idetape_write_release(drive, minor);
1593         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1594                 if (minor < 128)
1595                         ide_tape_discard_merge_buffer(drive, 1);
1596         }
1597
1598         if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1599                                     &drive->atapi_flags))
1600                 (void) idetape_rewind_tape(drive);
1601
1602         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1603                 if (tape->door_locked == DOOR_LOCKED) {
1604                         if (!ide_set_media_lock(drive, tape->disk, 0))
1605                                 tape->door_locked = DOOR_UNLOCKED;
1606                 }
1607         }
1608         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1609         ide_tape_put(tape);
1610
1611         mutex_unlock(&idetape_chrdev_mutex);
1612
1613         return 0;
1614 }
1615
1616 static void idetape_get_inquiry_results(ide_drive_t *drive)
1617 {
1618         idetape_tape_t *tape = drive->driver_data;
1619         struct ide_atapi_pc pc;
1620         u8 pc_buf[256];
1621         char fw_rev[4], vendor_id[8], product_id[16];
1622
1623         idetape_create_inquiry_cmd(&pc);
1624         if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1625                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1626                                 tape->name);
1627                 return;
1628         }
1629         memcpy(vendor_id, &pc_buf[8], 8);
1630         memcpy(product_id, &pc_buf[16], 16);
1631         memcpy(fw_rev, &pc_buf[32], 4);
1632
1633         ide_fixstring(vendor_id, 8, 0);
1634         ide_fixstring(product_id, 16, 0);
1635         ide_fixstring(fw_rev, 4, 0);
1636
1637         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1638                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1639 }
1640
1641 /*
1642  * Ask the tape about its various parameters. In particular, we will adjust our
1643  * data transfer buffer size to the recommended value as returned by the tape.
1644  */
1645 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1646 {
1647         idetape_tape_t *tape = drive->driver_data;
1648         struct ide_atapi_pc pc;
1649         u8 buf[24], *caps;
1650         u8 speed, max_speed;
1651
1652         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1653         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1654                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1655                                 " some default values\n");
1656                 tape->blk_size = 512;
1657                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1658                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1659                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1660                 return;
1661         }
1662         caps = buf + 4 + buf[3];
1663
1664         /* convert to host order and save for later use */
1665         speed = be16_to_cpup((__be16 *)&caps[14]);
1666         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1667
1668         *(u16 *)&caps[8] = max_speed;
1669         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1670         *(u16 *)&caps[14] = speed;
1671         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1672
1673         if (!speed) {
1674                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1675                                 "(assuming 650KB/sec)\n", drive->name);
1676                 *(u16 *)&caps[14] = 650;
1677         }
1678         if (!max_speed) {
1679                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1680                                 "(assuming 650KB/sec)\n", drive->name);
1681                 *(u16 *)&caps[8] = 650;
1682         }
1683
1684         memcpy(&tape->caps, caps, 20);
1685
1686         /* device lacks locking support according to capabilities page */
1687         if ((caps[6] & 1) == 0)
1688                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1689
1690         if (caps[7] & 0x02)
1691                 tape->blk_size = 512;
1692         else if (caps[7] & 0x04)
1693                 tape->blk_size = 1024;
1694 }
1695
1696 #ifdef CONFIG_IDE_PROC_FS
1697 #define ide_tape_devset_get(name, field) \
1698 static int get_##name(ide_drive_t *drive) \
1699 { \
1700         idetape_tape_t *tape = drive->driver_data; \
1701         return tape->field; \
1702 }
1703
1704 #define ide_tape_devset_set(name, field) \
1705 static int set_##name(ide_drive_t *drive, int arg) \
1706 { \
1707         idetape_tape_t *tape = drive->driver_data; \
1708         tape->field = arg; \
1709         return 0; \
1710 }
1711
1712 #define ide_tape_devset_rw_field(_name, _field) \
1713 ide_tape_devset_get(_name, _field) \
1714 ide_tape_devset_set(_name, _field) \
1715 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1716
1717 #define ide_tape_devset_r_field(_name, _field) \
1718 ide_tape_devset_get(_name, _field) \
1719 IDE_DEVSET(_name, 0, get_##_name, NULL)
1720
1721 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1722 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1723 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1724 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1725
1726 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1727
1728 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1729
1730 ide_tape_devset_r_field(avg_speed, avg_speed);
1731 ide_tape_devset_r_field(speed, caps[14]);
1732 ide_tape_devset_r_field(buffer, caps[16]);
1733 ide_tape_devset_r_field(buffer_size, buffer_size);
1734
1735 static const struct ide_proc_devset idetape_settings[] = {
1736         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1737         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1738         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1739         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1740         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1741         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1742                                         mulf_tdsc, divf_tdsc),
1743         { NULL },
1744 };
1745 #endif
1746
1747 /*
1748  * The function below is called to:
1749  *
1750  * 1. Initialize our various state variables.
1751  * 2. Ask the tape for its capabilities.
1752  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1753  * is chosen based on the recommendation which we received in step 2.
1754  *
1755  * Note that at this point ide.c already assigned us an irq, so that we can
1756  * queue requests here and wait for their completion.
1757  */
1758 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1759 {
1760         unsigned long t;
1761         int speed;
1762         u16 *ctl = (u16 *)&tape->caps[12];
1763
1764         ide_debug_log(IDE_DBG_FUNC, "minor: %d", minor);
1765
1766         drive->pc_callback = ide_tape_callback;
1767
1768         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1769
1770         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1771                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1772                                  tape->name);
1773                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1774         }
1775
1776         /* Seagate Travan drives do not support DSC overlap. */
1777         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1778                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1779
1780         tape->minor = minor;
1781         tape->name[0] = 'h';
1782         tape->name[1] = 't';
1783         tape->name[2] = '0' + minor;
1784         tape->chrdev_dir = IDETAPE_DIR_NONE;
1785
1786         idetape_get_inquiry_results(drive);
1787         idetape_get_mode_sense_results(drive);
1788         ide_tape_get_bsize_from_bdesc(drive);
1789         tape->user_bs_factor = 1;
1790         tape->buffer_size = *ctl * tape->blk_size;
1791         while (tape->buffer_size > 0xffff) {
1792                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1793                 *ctl /= 2;
1794                 tape->buffer_size = *ctl * tape->blk_size;
1795         }
1796
1797         /* select the "best" DSC read/write polling freq */
1798         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1799
1800         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1801
1802         /*
1803          * Ensure that the number we got makes sense; limit it within
1804          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1805          */
1806         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1807                                          IDETAPE_DSC_RW_MAX);
1808         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1809                 "%ums tDSC%s\n",
1810                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1811                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1812                 tape->buffer_size / 1024,
1813                 jiffies_to_msecs(tape->best_dsc_rw_freq),
1814                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1815
1816         ide_proc_register_driver(drive, tape->driver);
1817 }
1818
1819 static void ide_tape_remove(ide_drive_t *drive)
1820 {
1821         idetape_tape_t *tape = drive->driver_data;
1822
1823         ide_proc_unregister_driver(drive, tape->driver);
1824         device_del(&tape->dev);
1825
1826         mutex_lock(&idetape_ref_mutex);
1827         put_device(&tape->dev);
1828         mutex_unlock(&idetape_ref_mutex);
1829 }
1830
1831 static void ide_tape_release(struct device *dev)
1832 {
1833         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1834         ide_drive_t *drive = tape->drive;
1835         struct gendisk *g = tape->disk;
1836
1837         BUG_ON(tape->valid);
1838
1839         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1840         drive->driver_data = NULL;
1841         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1842         device_destroy(idetape_sysfs_class,
1843                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1844         idetape_devs[tape->minor] = NULL;
1845         g->private_data = NULL;
1846         put_disk(g);
1847         kfree(tape);
1848 }
1849
1850 #ifdef CONFIG_IDE_PROC_FS
1851 static int idetape_name_proc_show(struct seq_file *m, void *v)
1852 {
1853         ide_drive_t     *drive = (ide_drive_t *) m->private;
1854         idetape_tape_t  *tape = drive->driver_data;
1855
1856         seq_printf(m, "%s\n", tape->name);
1857         return 0;
1858 }
1859
1860 static ide_proc_entry_t idetape_proc[] = {
1861         { "capacity",   S_IFREG|S_IRUGO,        ide_capacity_proc_show  },
1862         { "name",       S_IFREG|S_IRUGO,        idetape_name_proc_show  },
1863         {}
1864 };
1865
1866 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1867 {
1868         return idetape_proc;
1869 }
1870
1871 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1872 {
1873         return idetape_settings;
1874 }
1875 #endif
1876
1877 static int ide_tape_probe(ide_drive_t *);
1878
1879 static struct ide_driver idetape_driver = {
1880         .gen_driver = {
1881                 .owner          = THIS_MODULE,
1882                 .name           = "ide-tape",
1883                 .bus            = &ide_bus_type,
1884         },
1885         .probe                  = ide_tape_probe,
1886         .remove                 = ide_tape_remove,
1887         .version                = IDETAPE_VERSION,
1888         .do_request             = idetape_do_request,
1889 #ifdef CONFIG_IDE_PROC_FS
1890         .proc_entries           = ide_tape_proc_entries,
1891         .proc_devsets           = ide_tape_proc_devsets,
1892 #endif
1893 };
1894
1895 /* Our character device supporting functions, passed to register_chrdev. */
1896 static const struct file_operations idetape_fops = {
1897         .owner          = THIS_MODULE,
1898         .read           = idetape_chrdev_read,
1899         .write          = idetape_chrdev_write,
1900         .unlocked_ioctl = idetape_chrdev_ioctl,
1901         .compat_ioctl   = IS_ENABLED(CONFIG_COMPAT) ?
1902                           idetape_chrdev_compat_ioctl : NULL,
1903         .open           = idetape_chrdev_open,
1904         .release        = idetape_chrdev_release,
1905         .llseek         = noop_llseek,
1906 };
1907
1908 static int idetape_open(struct block_device *bdev, fmode_t mode)
1909 {
1910         struct ide_tape_obj *tape;
1911
1912         mutex_lock(&ide_tape_mutex);
1913         tape = ide_tape_get(bdev->bd_disk, false, 0);
1914         mutex_unlock(&ide_tape_mutex);
1915
1916         if (!tape)
1917                 return -ENXIO;
1918
1919         return 0;
1920 }
1921
1922 static void idetape_release(struct gendisk *disk, fmode_t mode)
1923 {
1924         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1925
1926         mutex_lock(&ide_tape_mutex);
1927         ide_tape_put(tape);
1928         mutex_unlock(&ide_tape_mutex);
1929 }
1930
1931 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1932                         unsigned int cmd, unsigned long arg)
1933 {
1934         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1935         ide_drive_t *drive = tape->drive;
1936         int err;
1937
1938         mutex_lock(&ide_tape_mutex);
1939         err = generic_ide_ioctl(drive, bdev, cmd, arg);
1940         if (err == -EINVAL)
1941                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1942         mutex_unlock(&ide_tape_mutex);
1943
1944         return err;
1945 }
1946
1947 static int idetape_compat_ioctl(struct block_device *bdev, fmode_t mode,
1948                                 unsigned int cmd, unsigned long arg)
1949 {
1950         if (cmd == 0x0340 || cmd == 0x350)
1951                 arg = (unsigned long)compat_ptr(arg);
1952
1953         return idetape_ioctl(bdev, mode, cmd, arg);
1954 }
1955
1956 static const struct block_device_operations idetape_block_ops = {
1957         .owner          = THIS_MODULE,
1958         .open           = idetape_open,
1959         .release        = idetape_release,
1960         .ioctl          = idetape_ioctl,
1961         .compat_ioctl   = IS_ENABLED(CONFIG_COMPAT) ?
1962                                 idetape_compat_ioctl : NULL,
1963 };
1964
1965 static int ide_tape_probe(ide_drive_t *drive)
1966 {
1967         idetape_tape_t *tape;
1968         struct gendisk *g;
1969         int minor;
1970
1971         ide_debug_log(IDE_DBG_FUNC, "enter");
1972
1973         if (!strstr(DRV_NAME, drive->driver_req))
1974                 goto failed;
1975
1976         if (drive->media != ide_tape)
1977                 goto failed;
1978
1979         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1980             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1981                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1982                                 " the driver\n", drive->name);
1983                 goto failed;
1984         }
1985         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1986         if (tape == NULL) {
1987                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1988                                 drive->name);
1989                 goto failed;
1990         }
1991
1992         g = alloc_disk(1 << PARTN_BITS);
1993         if (!g)
1994                 goto out_free_tape;
1995
1996         ide_init_disk(g, drive);
1997
1998         tape->dev.parent = &drive->gendev;
1999         tape->dev.release = ide_tape_release;
2000         dev_set_name(&tape->dev, "%s", dev_name(&drive->gendev));
2001
2002         if (device_register(&tape->dev))
2003                 goto out_free_disk;
2004
2005         tape->drive = drive;
2006         tape->driver = &idetape_driver;
2007         tape->disk = g;
2008
2009         g->private_data = &tape->driver;
2010
2011         drive->driver_data = tape;
2012
2013         mutex_lock(&idetape_ref_mutex);
2014         for (minor = 0; idetape_devs[minor]; minor++)
2015                 ;
2016         idetape_devs[minor] = tape;
2017         mutex_unlock(&idetape_ref_mutex);
2018
2019         idetape_setup(drive, tape, minor);
2020
2021         device_create(idetape_sysfs_class, &drive->gendev,
2022                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2023         device_create(idetape_sysfs_class, &drive->gendev,
2024                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2025                       "n%s", tape->name);
2026
2027         g->fops = &idetape_block_ops;
2028
2029         return 0;
2030
2031 out_free_disk:
2032         put_disk(g);
2033 out_free_tape:
2034         kfree(tape);
2035 failed:
2036         return -ENODEV;
2037 }
2038
2039 static void __exit idetape_exit(void)
2040 {
2041         driver_unregister(&idetape_driver.gen_driver);
2042         class_destroy(idetape_sysfs_class);
2043         unregister_chrdev(IDETAPE_MAJOR, "ht");
2044 }
2045
2046 static int __init idetape_init(void)
2047 {
2048         int error = 1;
2049         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2050         if (IS_ERR(idetape_sysfs_class)) {
2051                 idetape_sysfs_class = NULL;
2052                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2053                 error = -EBUSY;
2054                 goto out;
2055         }
2056
2057         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2058                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2059                                 " interface\n");
2060                 error = -EBUSY;
2061                 goto out_free_class;
2062         }
2063
2064         error = driver_register(&idetape_driver.gen_driver);
2065         if (error)
2066                 goto out_free_chrdev;
2067
2068         return 0;
2069
2070 out_free_chrdev:
2071         unregister_chrdev(IDETAPE_MAJOR, "ht");
2072 out_free_class:
2073         class_destroy(idetape_sysfs_class);
2074 out:
2075         return error;
2076 }
2077
2078 MODULE_ALIAS("ide:*m-tape*");
2079 module_init(idetape_init);
2080 module_exit(idetape_exit);
2081 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2082 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2083 MODULE_LICENSE("GPL");