drivers/ide/ide-tape.c

   1 /*
   2  * IDE ATAPI streaming tape driver.
   3  *
   4  * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
   5  * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
   6  *
   7  * This driver was constructed as a student project in the software laboratory
   8  * of the faculty of electrical engineering in the Technion - Israel's
   9  * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
  10  *
  11  * It is hereby placed under the terms of the GNU general public license.
  12  * (See linux/COPYING).
  13  *
  14  * For a historical changelog see
  15  * Documentation/ide/ChangeLog.ide-tape.1995-2002
  16  */
  17
  18 #define DRV_NAME "ide-tape"
  19
  20 #define IDETAPE_VERSION "1.20"
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/kernel.h>
  26 #include <linux/delay.h>
  27 #include <linux/timer.h>
  28 #include <linux/mm.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/major.h>
  32 #include <linux/errno.h>
  33 #include <linux/genhd.h>
  34 #include <linux/seq_file.h>
  35 #include <linux/slab.h>
  36 #include <linux/pci.h>
  37 #include <linux/ide.h>
  38 #include <linux/completion.h>
  39 #include <linux/bitops.h>
  40 #include <linux/mutex.h>
  41 #include <scsi/scsi.h>
  42
  43 #include <asm/byteorder.h>
  44 #include <linux/irq.h>
  45 #include <linux/uaccess.h>
  46 #include <linux/io.h>
  47 #include <asm/unaligned.h>
  48 #include <linux/mtio.h>
  49
  50 /* define to see debug info */
  51 #undef IDETAPE_DEBUG_LOG
  52
  53 #ifdef IDETAPE_DEBUG_LOG
  54 #define ide_debug_log(lvl, fmt, args...) __ide_debug_log(lvl, fmt, ## args)
  55 #else
  56 #define ide_debug_log(lvl, fmt, args...) do {} while (0)
  57 #endif
  58
  59 /**************************** Tunable parameters *****************************/
  60 /*
  61  * After each failed packet command we issue a request sense command and retry
  62  * the packet command IDETAPE_MAX_PC_RETRIES times.
  63  *
  64  * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
  65  */
  66 #define IDETAPE_MAX_PC_RETRIES          3
  67
  68 /*
  69  * The following parameter is used to select the point in the internal tape fifo
  70  * in which we will start to refill the buffer. Decreasing the following
  71  * parameter will improve the system's latency and interactive response, while
  72  * using a high value might improve system throughput.
  73  */
  74 #define IDETAPE_FIFO_THRESHOLD          2
  75
  76 /*
  77  * DSC polling parameters.
  78  *
  79  * Polling for DSC (a single bit in the status register) is a very important
  80  * function in ide-tape. There are two cases in which we poll for DSC:
  81  *
  82  * 1. Before a read/write packet command, to ensure that we can transfer data
  83  * from/to the tape's data buffers, without causing an actual media access.
  84  * In case the tape is not ready yet, we take out our request from the device
  85  * request queue, so that ide.c could service requests from the other device
  86  * on the same interface in the meantime.
  87  *
  88  * 2. After the successful initialization of a "media access packet command",
  89  * which is a command that can take a long time to complete (the interval can
  90  * range from several seconds to even an hour). Again, we postpone our request
  91  * in the middle to free the bus for the other device. The polling frequency
  92  * here should be lower than the read/write frequency since those media access
  93  * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
  94  * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
  95  * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
  96  *
  97  * We also set a timeout for the timer, in case something goes wrong. The
  98  * timeout should be longer then the maximum execution time of a tape operation.
  99  */
 100
 101 /* DSC timings. */
 102 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 103 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 104 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 105 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 106 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 107 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 108 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 109
 110 /*************************** End of tunable parameters ***********************/
 111
 112 /* tape directions */
 113 enum {
 114         IDETAPE_DIR_NONE  = (1 << 0),
 115         IDETAPE_DIR_READ  = (1 << 1),
 116         IDETAPE_DIR_WRITE = (1 << 2),
 117 };
 118
 119 /* Tape door status */
 120 #define DOOR_UNLOCKED                   0
 121 #define DOOR_LOCKED                     1
 122 #define DOOR_EXPLICITLY_LOCKED          2
 123
 124 /* Some defines for the SPACE command */
 125 #define IDETAPE_SPACE_OVER_FILEMARK     1
 126 #define IDETAPE_SPACE_TO_EOD            3
 127
 128 /* Some defines for the LOAD UNLOAD command */
 129 #define IDETAPE_LU_LOAD_MASK            1
 130 #define IDETAPE_LU_RETENSION_MASK       2
 131 #define IDETAPE_LU_EOT_MASK             4
 132
 133 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
 134 #define IDETAPE_BLOCK_DESCRIPTOR        0
 135 #define IDETAPE_CAPABILITIES_PAGE       0x2a
 136
 137 /*
 138  * Most of our global data which we need to save even as we leave the driver due
 139  * to an interrupt or a timer event is stored in the struct defined below.
 140  */
 141 typedef struct ide_tape_obj {
 142         ide_drive_t             *drive;
 143         struct ide_driver       *driver;
 144         struct gendisk          *disk;
 145         struct device           dev;
 146
 147         /* used by REQ_IDETAPE_{READ,WRITE} requests */
 148         struct ide_atapi_pc queued_pc;
 149
 150         /*
 151          * DSC polling variables.
 152          *
 153          * While polling for DSC we use postponed_rq to postpone the current
 154          * request so that ide.c will be able to service pending requests on the
 155          * other device. Note that at most we will have only one DSC (usually
 156          * data transfer) request in the device request queue.
 157          */
 158         bool postponed_rq;
 159
 160         /* The time in which we started polling for DSC */
 161         unsigned long dsc_polling_start;
 162         /* Timer used to poll for dsc */
 163         struct timer_list dsc_timer;
 164         /* Read/Write dsc polling frequency */
 165         unsigned long best_dsc_rw_freq;
 166         unsigned long dsc_poll_freq;
 167         unsigned long dsc_timeout;
 168
 169         /* Read position information */
 170         u8 partition;
 171         /* Current block */
 172         unsigned int first_frame;
 173
 174         /* Last error information */
 175         u8 sense_key, asc, ascq;
 176
 177         /* Character device operation */
 178         unsigned int minor;
 179         /* device name */
 180         char name[4];
 181         /* Current character device data transfer direction */
 182         u8 chrdev_dir;
 183
 184         /* tape block size, usually 512 or 1024 bytes */
 185         unsigned short blk_size;
 186         int user_bs_factor;
 187
 188         /* Copy of the tape's Capabilities and Mechanical Page */
 189         u8 caps[20];
 190
 191         /*
 192          * Active data transfer request parameters.
 193          *
 194          * At most, there is only one ide-tape originated data transfer request
 195          * in the device request queue. This allows ide.c to easily service
 196          * requests from the other device when we postpone our active request.
 197          */
 198
 199         /* Data buffer size chosen based on the tape's recommendation */
 200         int buffer_size;
 201         /* Staging buffer of buffer_size bytes */
 202         void *buf;
 203         /* The read/write cursor */
 204         void *cur;
 205         /* The number of valid bytes in buf */
 206         size_t valid;
 207
 208         /* Measures average tape speed */
 209         unsigned long avg_time;
 210         int avg_size;
 211         int avg_speed;
 212
 213         /* the door is currently locked */
 214         int door_locked;
 215         /* the tape hardware is write protected */
 216         char drv_write_prot;
 217         /* the tape is write protected (hardware or opened as read-only) */
 218         char write_prot;
 219 } idetape_tape_t;
 220
 221 static DEFINE_MUTEX(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                 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) - 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) - 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         rq->errors = 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, -EIO, 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(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         u8 stat;
 575
 576         ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, sector: %llu, nr_sectors: %u",
 577                       rq->cmd[0], (unsigned long long)blk_rq_pos(rq),
 578                       blk_rq_sectors(rq));
 579
 580         BUG_ON(!(rq->cmd_type == REQ_TYPE_SPECIAL ||
 581                  rq->cmd_type == REQ_TYPE_SENSE));
 582
 583         /* Retry a failed packet command */
 584         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 585                 pc = drive->failed_pc;
 586                 goto out;
 587         }
 588
 589         /*
 590          * If the tape is still busy, postpone our request and service
 591          * the other device meanwhile.
 592          */
 593         stat = hwif->tp_ops->read_status(hwif);
 594
 595         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 596             (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
 597                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 598
 599         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 600                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 601                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 602         }
 603
 604         if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
 605             !(stat & ATA_DSC)) {
 606                 if (!tape->postponed_rq) {
 607                         tape->dsc_polling_start = jiffies;
 608                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 609                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 610                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 611                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 612                                 tape->name);
 613                         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 614                                 idetape_media_access_finished(drive);
 615                                 return ide_stopped;
 616                         } else {
 617                                 return ide_do_reset(drive);
 618                         }
 619                 } else if (time_after(jiffies,
 620                                         tape->dsc_polling_start +
 621                                         IDETAPE_DSC_MA_THRESHOLD))
 622                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 623                 ide_tape_stall_queue(drive);
 624                 return ide_stopped;
 625         } else {
 626                 drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
 627                 tape->postponed_rq = false;
 628         }
 629
 630         if (rq->cmd[13] & REQ_IDETAPE_READ) {
 631                 pc = &tape->queued_pc;
 632                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 633                 goto out;
 634         }
 635         if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
 636                 pc = &tape->queued_pc;
 637                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 638                 goto out;
 639         }
 640         if (rq->cmd[13] & REQ_IDETAPE_PC1) {
 641                 pc = (struct ide_atapi_pc *)rq->special;
 642                 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
 643                 rq->cmd[13] |= REQ_IDETAPE_PC2;
 644                 goto out;
 645         }
 646         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 647                 idetape_media_access_finished(drive);
 648                 return ide_stopped;
 649         }
 650         BUG();
 651
 652 out:
 653         /* prepare sense request for this command */
 654         ide_prep_sense(drive, rq);
 655
 656         memset(&cmd, 0, sizeof(cmd));
 657
 658         if (rq_data_dir(rq))
 659                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 660
 661         cmd.rq = rq;
 662
 663         ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
 664         ide_map_sg(drive, &cmd);
 665
 666         return ide_tape_issue_pc(drive, &cmd, pc);
 667 }
 668
 669 /*
 670  * Write a filemark if write_filemark=1. Flush the device buffers without
 671  * writing a filemark otherwise.
 672  */
 673 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 674                 struct ide_atapi_pc *pc, int write_filemark)
 675 {
 676         ide_init_pc(pc);
 677         pc->c[0] = WRITE_FILEMARKS;
 678         pc->c[4] = write_filemark;
 679         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 680 }
 681
 682 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 683 {
 684         idetape_tape_t *tape = drive->driver_data;
 685         struct gendisk *disk = tape->disk;
 686         int load_attempted = 0;
 687
 688         /* Wait for the tape to become ready */
 689         set_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT), &drive->atapi_flags);
 690         timeout += jiffies;
 691         while (time_before(jiffies, timeout)) {
 692                 if (ide_do_test_unit_ready(drive, disk) == 0)
 693                         return 0;
 694                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 695                     || (tape->asc == 0x3A)) {
 696                         /* no media */
 697                         if (load_attempted)
 698                                 return -ENOMEDIUM;
 699                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 700                         load_attempted = 1;
 701                 /* not about to be ready */
 702                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 703                              (tape->ascq == 1 || tape->ascq == 8)))
 704                         return -EIO;
 705                 msleep(100);
 706         }
 707         return -EIO;
 708 }
 709
 710 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 711 {
 712         struct ide_tape_obj *tape = drive->driver_data;
 713         struct ide_atapi_pc pc;
 714         int rc;
 715
 716         idetape_create_write_filemark_cmd(drive, &pc, 0);
 717         rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
 718         if (rc)
 719                 return rc;
 720         idetape_wait_ready(drive, 60 * 5 * HZ);
 721         return 0;
 722 }
 723
 724 static int ide_tape_read_position(ide_drive_t *drive)
 725 {
 726         idetape_tape_t *tape = drive->driver_data;
 727         struct ide_atapi_pc pc;
 728         u8 buf[20];
 729
 730         ide_debug_log(IDE_DBG_FUNC, "enter");
 731
 732         /* prep cmd */
 733         ide_init_pc(&pc);
 734         pc.c[0] = READ_POSITION;
 735         pc.req_xfer = 20;
 736
 737         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
 738                 return -1;
 739
 740         if (!pc.error) {
 741                 ide_debug_log(IDE_DBG_FUNC, "BOP - %s",
 742                                 (buf[0] & 0x80) ? "Yes" : "No");
 743                 ide_debug_log(IDE_DBG_FUNC, "EOP - %s",
 744                                 (buf[0] & 0x40) ? "Yes" : "No");
 745
 746                 if (buf[0] & 0x4) {
 747                         printk(KERN_INFO "ide-tape: Block location is unknown"
 748                                          "to the tape\n");
 749                         clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 750                                   &drive->atapi_flags);
 751                         return -1;
 752                 } else {
 753                         ide_debug_log(IDE_DBG_FUNC, "Block Location: %u",
 754                                       be32_to_cpup((__be32 *)&buf[4]));
 755
 756                         tape->partition = buf[1];
 757                         tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
 758                         set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 759                                 &drive->atapi_flags);
 760                 }
 761         }
 762
 763         return tape->first_frame;
 764 }
 765
 766 static void idetape_create_locate_cmd(ide_drive_t *drive,
 767                 struct ide_atapi_pc *pc,
 768                 unsigned int block, u8 partition, int skip)
 769 {
 770         ide_init_pc(pc);
 771         pc->c[0] = POSITION_TO_ELEMENT;
 772         pc->c[1] = 2;
 773         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 774         pc->c[8] = partition;
 775         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 776 }
 777
 778 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 779 {
 780         idetape_tape_t *tape = drive->driver_data;
 781
 782         if (tape->chrdev_dir != IDETAPE_DIR_READ)
 783                 return;
 784
 785         clear_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
 786         tape->valid = 0;
 787         if (tape->buf != NULL) {
 788                 kfree(tape->buf);
 789                 tape->buf = NULL;
 790         }
 791
 792         tape->chrdev_dir = IDETAPE_DIR_NONE;
 793 }
 794
 795 /*
 796  * Position the tape to the requested block using the LOCATE packet command.
 797  * A READ POSITION command is then issued to check where we are positioned. Like
 798  * all higher level operations, we queue the commands at the tail of the request
 799  * queue and wait for their completion.
 800  */
 801 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 802                 u8 partition, int skip)
 803 {
 804         idetape_tape_t *tape = drive->driver_data;
 805         struct gendisk *disk = tape->disk;
 806         int ret;
 807         struct ide_atapi_pc pc;
 808
 809         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 810                 __ide_tape_discard_merge_buffer(drive);
 811         idetape_wait_ready(drive, 60 * 5 * HZ);
 812         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 813         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 814         if (ret)
 815                 return ret;
 816
 817         ret = ide_tape_read_position(drive);
 818         if (ret < 0)
 819                 return ret;
 820         return 0;
 821 }
 822
 823 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 824                                           int restore_position)
 825 {
 826         idetape_tape_t *tape = drive->driver_data;
 827         int seek, position;
 828
 829         __ide_tape_discard_merge_buffer(drive);
 830         if (restore_position) {
 831                 position = ide_tape_read_position(drive);
 832                 seek = position > 0 ? position : 0;
 833                 if (idetape_position_tape(drive, seek, 0, 0)) {
 834                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 835                                          " %s\n", tape->name, __func__);
 836                         return;
 837                 }
 838         }
 839 }
 840
 841 /*
 842  * Generate a read/write request for the block device interface and wait for it
 843  * to be serviced.
 844  */
 845 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 846 {
 847         idetape_tape_t *tape = drive->driver_data;
 848         struct request *rq;
 849         int ret;
 850
 851         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, size: %d", cmd, size);
 852
 853         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 854         BUG_ON(size < 0 || size % tape->blk_size);
 855
 856         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
 857         rq->cmd_type = REQ_TYPE_SPECIAL;
 858         rq->cmd[13] = cmd;
 859         rq->rq_disk = tape->disk;
 860         rq->__sector = tape->first_frame;
 861
 862         if (size) {
 863                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 864                                       __GFP_WAIT);
 865                 if (ret)
 866                         goto out_put;
 867         }
 868
 869         blk_execute_rq(drive->queue, tape->disk, rq, 0);
 870
 871         /* calculate the number of transferred bytes and update buffer state */
 872         size -= rq->resid_len;
 873         tape->cur = tape->buf;
 874         if (cmd == REQ_IDETAPE_READ)
 875                 tape->valid = size;
 876         else
 877                 tape->valid = 0;
 878
 879         ret = size;
 880         if (rq->errors == IDE_DRV_ERROR_GENERAL)
 881                 ret = -EIO;
 882 out_put:
 883         blk_put_request(rq);
 884         return ret;
 885 }
 886
 887 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 888 {
 889         ide_init_pc(pc);
 890         pc->c[0] = INQUIRY;
 891         pc->c[4] = 254;
 892         pc->req_xfer = 254;
 893 }
 894
 895 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 896                 struct ide_atapi_pc *pc)
 897 {
 898         ide_init_pc(pc);
 899         pc->c[0] = REZERO_UNIT;
 900         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 901 }
 902
 903 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 904 {
 905         ide_init_pc(pc);
 906         pc->c[0] = ERASE;
 907         pc->c[1] = 1;
 908         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 909 }
 910
 911 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 912 {
 913         ide_init_pc(pc);
 914         pc->c[0] = SPACE;
 915         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 916         pc->c[1] = cmd;
 917         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 918 }
 919
 920 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 921 {
 922         idetape_tape_t *tape = drive->driver_data;
 923
 924         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 925                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 926                                 " but we are not writing.\n");
 927                 return;
 928         }
 929         if (tape->buf) {
 930                 size_t aligned = roundup(tape->valid, tape->blk_size);
 931
 932                 memset(tape->cur, 0, aligned - tape->valid);
 933                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 934                 kfree(tape->buf);
 935                 tape->buf = NULL;
 936         }
 937         tape->chrdev_dir = IDETAPE_DIR_NONE;
 938 }
 939
 940 static int idetape_init_rw(ide_drive_t *drive, int dir)
 941 {
 942         idetape_tape_t *tape = drive->driver_data;
 943         int rc;
 944
 945         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 946
 947         if (tape->chrdev_dir == dir)
 948                 return 0;
 949
 950         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 951                 ide_tape_discard_merge_buffer(drive, 1);
 952         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 953                 ide_tape_flush_merge_buffer(drive);
 954                 idetape_flush_tape_buffers(drive);
 955         }
 956
 957         if (tape->buf || tape->valid) {
 958                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 959                 tape->valid = 0;
 960         }
 961
 962         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 963         if (!tape->buf)
 964                 return -ENOMEM;
 965         tape->chrdev_dir = dir;
 966         tape->cur = tape->buf;
 967
 968         /*
 969          * Issue a 0 rw command to ensure that DSC handshake is
 970          * switched from completion mode to buffer available mode.  No
 971          * point in issuing this if DSC overlap isn't supported, some
 972          * drives (Seagate STT3401A) will return an error.
 973          */
 974         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
 975                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
 976                                                   : REQ_IDETAPE_WRITE;
 977
 978                 rc = idetape_queue_rw_tail(drive, cmd, 0);
 979                 if (rc < 0) {
 980                         kfree(tape->buf);
 981                         tape->buf = NULL;
 982                         tape->chrdev_dir = IDETAPE_DIR_NONE;
 983                         return rc;
 984                 }
 985         }
 986
 987         return 0;
 988 }
 989
 990 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
 991 {
 992         idetape_tape_t *tape = drive->driver_data;
 993
 994         memset(tape->buf, 0, tape->buffer_size);
 995
 996         while (bcount) {
 997                 unsigned int count = min(tape->buffer_size, bcount);
 998
 999                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1000                 bcount -= count;
1001         }
1002 }
1003
1004 /*
1005  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1006  * currently support only one partition.
1007  */
1008 static int idetape_rewind_tape(ide_drive_t *drive)
1009 {
1010         struct ide_tape_obj *tape = drive->driver_data;
1011         struct gendisk *disk = tape->disk;
1012         struct ide_atapi_pc pc;
1013         int ret;
1014
1015         ide_debug_log(IDE_DBG_FUNC, "enter");
1016
1017         idetape_create_rewind_cmd(drive, &pc);
1018         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1019         if (ret)
1020                 return ret;
1021
1022         ret = ide_tape_read_position(drive);
1023         if (ret < 0)
1024                 return ret;
1025         return 0;
1026 }
1027
1028 /* mtio.h compatible commands should be issued to the chrdev interface. */
1029 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1030                                 unsigned long arg)
1031 {
1032         idetape_tape_t *tape = drive->driver_data;
1033         void __user *argp = (void __user *)arg;
1034
1035         struct idetape_config {
1036                 int dsc_rw_frequency;
1037                 int dsc_media_access_frequency;
1038                 int nr_stages;
1039         } config;
1040
1041         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%04x", cmd);
1042
1043         switch (cmd) {
1044         case 0x0340:
1045                 if (copy_from_user(&config, argp, sizeof(config)))
1046                         return -EFAULT;
1047                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1048                 break;
1049         case 0x0350:
1050                 memset(&config, 0, sizeof(config));
1051                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1052                 config.nr_stages = 1;
1053                 if (copy_to_user(argp, &config, sizeof(config)))
1054                         return -EFAULT;
1055                 break;
1056         default:
1057                 return -EIO;
1058         }
1059         return 0;
1060 }
1061
1062 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1063                                         int mt_count)
1064 {
1065         idetape_tape_t *tape = drive->driver_data;
1066         struct gendisk *disk = tape->disk;
1067         struct ide_atapi_pc pc;
1068         int retval, count = 0;
1069         int sprev = !!(tape->caps[4] & 0x20);
1070
1071
1072         ide_debug_log(IDE_DBG_FUNC, "mt_op: %d, mt_count: %d", mt_op, mt_count);
1073
1074         if (mt_count == 0)
1075                 return 0;
1076         if (MTBSF == mt_op || MTBSFM == mt_op) {
1077                 if (!sprev)
1078                         return -EIO;
1079                 mt_count = -mt_count;
1080         }
1081
1082         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1083                 tape->valid = 0;
1084                 if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1085                                        &drive->atapi_flags))
1086                         ++count;
1087                 ide_tape_discard_merge_buffer(drive, 0);
1088         }
1089
1090         switch (mt_op) {
1091         case MTFSF:
1092         case MTBSF:
1093                 idetape_create_space_cmd(&pc, mt_count - count,
1094                                          IDETAPE_SPACE_OVER_FILEMARK);
1095                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1096         case MTFSFM:
1097         case MTBSFM:
1098                 if (!sprev)
1099                         return -EIO;
1100                 retval = idetape_space_over_filemarks(drive, MTFSF,
1101                                                       mt_count - count);
1102                 if (retval)
1103                         return retval;
1104                 count = (MTBSFM == mt_op ? 1 : -1);
1105                 return idetape_space_over_filemarks(drive, MTFSF, count);
1106         default:
1107                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1108                                 mt_op);
1109                 return -EIO;
1110         }
1111 }
1112
1113 /*
1114  * Our character device read / write functions.
1115  *
1116  * The tape is optimized to maximize throughput when it is transferring an
1117  * integral number of the "continuous transfer limit", which is a parameter of
1118  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1119  *
1120  * As of version 1.3 of the driver, the character device provides an abstract
1121  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1122  * same backup/restore procedure is supported. The driver will internally
1123  * convert the requests to the recommended transfer unit, so that an unmatch
1124  * between the user's block size to the recommended size will only result in a
1125  * (slightly) increased driver overhead, but will no longer hit performance.
1126  * This is not applicable to Onstream.
1127  */
1128 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1129                                    size_t count, loff_t *ppos)
1130 {
1131         struct ide_tape_obj *tape = file->private_data;
1132         ide_drive_t *drive = tape->drive;
1133         size_t done = 0;
1134         ssize_t ret = 0;
1135         int rc;
1136
1137         ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1138
1139         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1140                 if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1141                         if (count > tape->blk_size &&
1142                             (count % tape->blk_size) == 0)
1143                                 tape->user_bs_factor = count / tape->blk_size;
1144         }
1145
1146         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1147         if (rc < 0)
1148                 return rc;
1149
1150         while (done < count) {
1151                 size_t todo;
1152
1153                 /* refill if staging buffer is empty */
1154                 if (!tape->valid) {
1155                         /* If we are at a filemark, nothing more to read */
1156                         if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1157                                      &drive->atapi_flags))
1158                                 break;
1159                         /* read */
1160                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1161                                                   tape->buffer_size) <= 0)
1162                                 break;
1163                 }
1164
1165                 /* copy out */
1166                 todo = min_t(size_t, count - done, tape->valid);
1167                 if (copy_to_user(buf + done, tape->cur, todo))
1168                         ret = -EFAULT;
1169
1170                 tape->cur += todo;
1171                 tape->valid -= todo;
1172                 done += todo;
1173         }
1174
1175         if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1176                 idetape_space_over_filemarks(drive, MTFSF, 1);
1177                 return 0;
1178         }
1179
1180         return ret ? ret : done;
1181 }
1182
1183 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1184                                      size_t count, loff_t *ppos)
1185 {
1186         struct ide_tape_obj *tape = file->private_data;
1187         ide_drive_t *drive = tape->drive;
1188         size_t done = 0;
1189         ssize_t ret = 0;
1190         int rc;
1191
1192         /* The drive is write protected. */
1193         if (tape->write_prot)
1194                 return -EACCES;
1195
1196         ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1197
1198         /* Initialize write operation */
1199         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1200         if (rc < 0)
1201                 return rc;
1202
1203         while (done < count) {
1204                 size_t todo;
1205
1206                 /* flush if staging buffer is full */
1207                 if (tape->valid == tape->buffer_size &&
1208                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1209                                           tape->buffer_size) <= 0)
1210                         return rc;
1211
1212                 /* copy in */
1213                 todo = min_t(size_t, count - done,
1214                              tape->buffer_size - tape->valid);
1215                 if (copy_from_user(tape->cur, buf + done, todo))
1216                         ret = -EFAULT;
1217
1218                 tape->cur += todo;
1219                 tape->valid += todo;
1220                 done += todo;
1221         }
1222
1223         return ret ? ret : done;
1224 }
1225
1226 static int idetape_write_filemark(ide_drive_t *drive)
1227 {
1228         struct ide_tape_obj *tape = drive->driver_data;
1229         struct ide_atapi_pc pc;
1230
1231         /* Write a filemark */
1232         idetape_create_write_filemark_cmd(drive, &pc, 1);
1233         if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1234                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1235                 return -EIO;
1236         }
1237         return 0;
1238 }
1239
1240 /*
1241  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1242  * requested.
1243  *
1244  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1245  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1246  * usually not supported.
1247  *
1248  * The following commands are currently not supported:
1249  *
1250  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1251  * MT_ST_WRITE_THRESHOLD.
1252  */
1253 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1254 {
1255         idetape_tape_t *tape = drive->driver_data;
1256         struct gendisk *disk = tape->disk;
1257         struct ide_atapi_pc pc;
1258         int i, retval;
1259
1260         ide_debug_log(IDE_DBG_FUNC, "MTIOCTOP ioctl: mt_op: %d, mt_count: %d",
1261                       mt_op, mt_count);
1262
1263         switch (mt_op) {
1264         case MTFSF:
1265         case MTFSFM:
1266         case MTBSF:
1267         case MTBSFM:
1268                 if (!mt_count)
1269                         return 0;
1270                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1271         default:
1272                 break;
1273         }
1274
1275         switch (mt_op) {
1276         case MTWEOF:
1277                 if (tape->write_prot)
1278                         return -EACCES;
1279                 ide_tape_discard_merge_buffer(drive, 1);
1280                 for (i = 0; i < mt_count; i++) {
1281                         retval = idetape_write_filemark(drive);
1282                         if (retval)
1283                                 return retval;
1284                 }
1285                 return 0;
1286         case MTREW:
1287                 ide_tape_discard_merge_buffer(drive, 0);
1288                 if (idetape_rewind_tape(drive))
1289                         return -EIO;
1290                 return 0;
1291         case MTLOAD:
1292                 ide_tape_discard_merge_buffer(drive, 0);
1293                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1294         case MTUNLOAD:
1295         case MTOFFL:
1296                 /*
1297                  * If door is locked, attempt to unlock before
1298                  * attempting to eject.
1299                  */
1300                 if (tape->door_locked) {
1301                         if (!ide_set_media_lock(drive, disk, 0))
1302                                 tape->door_locked = DOOR_UNLOCKED;
1303                 }
1304                 ide_tape_discard_merge_buffer(drive, 0);
1305                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1306                 if (!retval)
1307                         clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1308                                   &drive->atapi_flags);
1309                 return retval;
1310         case MTNOP:
1311                 ide_tape_discard_merge_buffer(drive, 0);
1312                 return idetape_flush_tape_buffers(drive);
1313         case MTRETEN:
1314                 ide_tape_discard_merge_buffer(drive, 0);
1315                 return ide_do_start_stop(drive, disk,
1316                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1317         case MTEOM:
1318                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1319                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1320         case MTERASE:
1321                 (void)idetape_rewind_tape(drive);
1322                 idetape_create_erase_cmd(&pc);
1323                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1324         case MTSETBLK:
1325                 if (mt_count) {
1326                         if (mt_count < tape->blk_size ||
1327                             mt_count % tape->blk_size)
1328                                 return -EIO;
1329                         tape->user_bs_factor = mt_count / tape->blk_size;
1330                         clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1331                                   &drive->atapi_flags);
1332                 } else
1333                         set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1334                                 &drive->atapi_flags);
1335                 return 0;
1336         case MTSEEK:
1337                 ide_tape_discard_merge_buffer(drive, 0);
1338                 return idetape_position_tape(drive,
1339                         mt_count * tape->user_bs_factor, tape->partition, 0);
1340         case MTSETPART:
1341                 ide_tape_discard_merge_buffer(drive, 0);
1342                 return idetape_position_tape(drive, 0, mt_count, 0);
1343         case MTFSR:
1344         case MTBSR:
1345         case MTLOCK:
1346                 retval = ide_set_media_lock(drive, disk, 1);
1347                 if (retval)
1348                         return retval;
1349                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1350                 return 0;
1351         case MTUNLOCK:
1352                 retval = ide_set_media_lock(drive, disk, 0);
1353                 if (retval)
1354                         return retval;
1355                 tape->door_locked = DOOR_UNLOCKED;
1356                 return 0;
1357         default:
1358                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1359                                 mt_op);
1360                 return -EIO;
1361         }
1362 }
1363
1364 /*
1365  * Our character device ioctls. General mtio.h magnetic io commands are
1366  * supported here, and not in the corresponding block interface. Our own
1367  * ide-tape ioctls are supported on both interfaces.
1368  */
1369 static long do_idetape_chrdev_ioctl(struct file *file,
1370                                 unsigned int cmd, unsigned long arg)
1371 {
1372         struct ide_tape_obj *tape = file->private_data;
1373         ide_drive_t *drive = tape->drive;
1374         struct mtop mtop;
1375         struct mtget mtget;
1376         struct mtpos mtpos;
1377         int block_offset = 0, position = tape->first_frame;
1378         void __user *argp = (void __user *)arg;
1379
1380         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x", cmd);
1381
1382         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1383                 ide_tape_flush_merge_buffer(drive);
1384                 idetape_flush_tape_buffers(drive);
1385         }
1386         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1387                 block_offset = tape->valid /
1388                         (tape->blk_size * tape->user_bs_factor);
1389                 position = ide_tape_read_position(drive);
1390                 if (position < 0)
1391                         return -EIO;
1392         }
1393         switch (cmd) {
1394         case MTIOCTOP:
1395                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1396                         return -EFAULT;
1397                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1398         case MTIOCGET:
1399                 memset(&mtget, 0, sizeof(struct mtget));
1400                 mtget.mt_type = MT_ISSCSI2;
1401                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1402                 mtget.mt_dsreg =
1403                         ((tape->blk_size * tape->user_bs_factor)
1404                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1405
1406                 if (tape->drv_write_prot)
1407                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1408
1409                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1410                         return -EFAULT;
1411                 return 0;
1412         case MTIOCPOS:
1413                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1414                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1415                         return -EFAULT;
1416                 return 0;
1417         default:
1418                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1419                         ide_tape_discard_merge_buffer(drive, 1);
1420                 return idetape_blkdev_ioctl(drive, cmd, arg);
1421         }
1422 }
1423
1424 static long idetape_chrdev_ioctl(struct file *file,
1425                                 unsigned int cmd, unsigned long arg)
1426 {
1427         long ret;
1428         mutex_lock(&ide_tape_mutex);
1429         ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1430         mutex_unlock(&ide_tape_mutex);
1431         return ret;
1432 }
1433
1434 /*
1435  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1436  * block size with the reported value.
1437  */
1438 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1439 {
1440         idetape_tape_t *tape = drive->driver_data;
1441         struct ide_atapi_pc pc;
1442         u8 buf[12];
1443
1444         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1445         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1446                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1447                 if (tape->blk_size == 0) {
1448                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1449                                             "block size, assuming 32k\n");
1450                         tape->blk_size = 32768;
1451                 }
1452                 return;
1453         }
1454         tape->blk_size = (buf[4 + 5] << 16) +
1455                                 (buf[4 + 6] << 8)  +
1456                                  buf[4 + 7];
1457         tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1458
1459         ide_debug_log(IDE_DBG_FUNC, "blk_size: %d, write_prot: %d",
1460                       tape->blk_size, tape->drv_write_prot);
1461 }
1462
1463 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1464 {
1465         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1466         ide_drive_t *drive;
1467         idetape_tape_t *tape;
1468         int retval;
1469
1470         if (i >= MAX_HWIFS * MAX_DRIVES)
1471                 return -ENXIO;
1472
1473         mutex_lock(&idetape_chrdev_mutex);
1474
1475         tape = ide_tape_get(NULL, true, i);
1476         if (!tape) {
1477                 mutex_unlock(&idetape_chrdev_mutex);
1478                 return -ENXIO;
1479         }
1480
1481         drive = tape->drive;
1482         filp->private_data = tape;
1483
1484         ide_debug_log(IDE_DBG_FUNC, "enter");
1485
1486         /*
1487          * We really want to do nonseekable_open(inode, filp); here, but some
1488          * versions of tar incorrectly call lseek on tapes and bail out if that
1489          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1490          */
1491         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1492
1493
1494         if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1495                 retval = -EBUSY;
1496                 goto out_put_tape;
1497         }
1498
1499         retval = idetape_wait_ready(drive, 60 * HZ);
1500         if (retval) {
1501                 clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1502                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1503                 goto out_put_tape;
1504         }
1505
1506         ide_tape_read_position(drive);
1507         if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1508                 (void)idetape_rewind_tape(drive);
1509
1510         /* Read block size and write protect status from drive. */
1511         ide_tape_get_bsize_from_bdesc(drive);
1512
1513         /* Set write protect flag if device is opened as read-only. */
1514         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1515                 tape->write_prot = 1;
1516         else
1517                 tape->write_prot = tape->drv_write_prot;
1518
1519         /* Make sure drive isn't write protected if user wants to write. */
1520         if (tape->write_prot) {
1521                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1522                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1523                         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1524                         retval = -EROFS;
1525                         goto out_put_tape;
1526                 }
1527         }
1528
1529         /* Lock the tape drive door so user can't eject. */
1530         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1531                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1532                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1533                                 tape->door_locked = DOOR_LOCKED;
1534                 }
1535         }
1536         mutex_unlock(&idetape_chrdev_mutex);
1537
1538         return 0;
1539
1540 out_put_tape:
1541         ide_tape_put(tape);
1542
1543         mutex_unlock(&idetape_chrdev_mutex);
1544
1545         return retval;
1546 }
1547
1548 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1549 {
1550         idetape_tape_t *tape = drive->driver_data;
1551
1552         ide_tape_flush_merge_buffer(drive);
1553         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1554         if (tape->buf != NULL) {
1555                 idetape_pad_zeros(drive, tape->blk_size *
1556                                 (tape->user_bs_factor - 1));
1557                 kfree(tape->buf);
1558                 tape->buf = NULL;
1559         }
1560         idetape_write_filemark(drive);
1561         idetape_flush_tape_buffers(drive);
1562         idetape_flush_tape_buffers(drive);
1563 }
1564
1565 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1566 {
1567         struct ide_tape_obj *tape = filp->private_data;
1568         ide_drive_t *drive = tape->drive;
1569         unsigned int minor = iminor(inode);
1570
1571         mutex_lock(&idetape_chrdev_mutex);
1572
1573         tape = drive->driver_data;
1574
1575         ide_debug_log(IDE_DBG_FUNC, "enter");
1576
1577         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1578                 idetape_write_release(drive, minor);
1579         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1580                 if (minor < 128)
1581                         ide_tape_discard_merge_buffer(drive, 1);
1582         }
1583
1584         if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1585                                     &drive->atapi_flags))
1586                 (void) idetape_rewind_tape(drive);
1587
1588         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1589                 if (tape->door_locked == DOOR_LOCKED) {
1590                         if (!ide_set_media_lock(drive, tape->disk, 0))
1591                                 tape->door_locked = DOOR_UNLOCKED;
1592                 }
1593         }
1594         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1595         ide_tape_put(tape);
1596
1597         mutex_unlock(&idetape_chrdev_mutex);
1598
1599         return 0;
1600 }
1601
1602 static void idetape_get_inquiry_results(ide_drive_t *drive)
1603 {
1604         idetape_tape_t *tape = drive->driver_data;
1605         struct ide_atapi_pc pc;
1606         u8 pc_buf[256];
1607         char fw_rev[4], vendor_id[8], product_id[16];
1608
1609         idetape_create_inquiry_cmd(&pc);
1610         if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1611                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1612                                 tape->name);
1613                 return;
1614         }
1615         memcpy(vendor_id, &pc_buf[8], 8);
1616         memcpy(product_id, &pc_buf[16], 16);
1617         memcpy(fw_rev, &pc_buf[32], 4);
1618
1619         ide_fixstring(vendor_id, 8, 0);
1620         ide_fixstring(product_id, 16, 0);
1621         ide_fixstring(fw_rev, 4, 0);
1622
1623         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1624                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1625 }
1626
1627 /*
1628  * Ask the tape about its various parameters. In particular, we will adjust our
1629  * data transfer buffer size to the recommended value as returned by the tape.
1630  */
1631 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1632 {
1633         idetape_tape_t *tape = drive->driver_data;
1634         struct ide_atapi_pc pc;
1635         u8 buf[24], *caps;
1636         u8 speed, max_speed;
1637
1638         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1639         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1640                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1641                                 " some default values\n");
1642                 tape->blk_size = 512;
1643                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1644                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1645                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1646                 return;
1647         }
1648         caps = buf + 4 + buf[3];
1649
1650         /* convert to host order and save for later use */
1651         speed = be16_to_cpup((__be16 *)&caps[14]);
1652         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1653
1654         *(u16 *)&caps[8] = max_speed;
1655         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1656         *(u16 *)&caps[14] = speed;
1657         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1658
1659         if (!speed) {
1660                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1661                                 "(assuming 650KB/sec)\n", drive->name);
1662                 *(u16 *)&caps[14] = 650;
1663         }
1664         if (!max_speed) {
1665                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1666                                 "(assuming 650KB/sec)\n", drive->name);
1667                 *(u16 *)&caps[8] = 650;
1668         }
1669
1670         memcpy(&tape->caps, caps, 20);
1671
1672         /* device lacks locking support according to capabilities page */
1673         if ((caps[6] & 1) == 0)
1674                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1675
1676         if (caps[7] & 0x02)
1677                 tape->blk_size = 512;
1678         else if (caps[7] & 0x04)
1679                 tape->blk_size = 1024;
1680 }
1681
1682 #ifdef CONFIG_IDE_PROC_FS
1683 #define ide_tape_devset_get(name, field) \
1684 static int get_##name(ide_drive_t *drive) \
1685 { \
1686         idetape_tape_t *tape = drive->driver_data; \
1687         return tape->field; \
1688 }
1689
1690 #define ide_tape_devset_set(name, field) \
1691 static int set_##name(ide_drive_t *drive, int arg) \
1692 { \
1693         idetape_tape_t *tape = drive->driver_data; \
1694         tape->field = arg; \
1695         return 0; \
1696 }
1697
1698 #define ide_tape_devset_rw_field(_name, _field) \
1699 ide_tape_devset_get(_name, _field) \
1700 ide_tape_devset_set(_name, _field) \
1701 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1702
1703 #define ide_tape_devset_r_field(_name, _field) \
1704 ide_tape_devset_get(_name, _field) \
1705 IDE_DEVSET(_name, 0, get_##_name, NULL)
1706
1707 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1708 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1709 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1710 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1711
1712 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1713
1714 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1715
1716 ide_tape_devset_r_field(avg_speed, avg_speed);
1717 ide_tape_devset_r_field(speed, caps[14]);
1718 ide_tape_devset_r_field(buffer, caps[16]);
1719 ide_tape_devset_r_field(buffer_size, buffer_size);
1720
1721 static const struct ide_proc_devset idetape_settings[] = {
1722         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1723         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1724         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1725         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1726         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1727         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1728                                         mulf_tdsc, divf_tdsc),
1729         { NULL },
1730 };
1731 #endif
1732
1733 /*
1734  * The function below is called to:
1735  *
1736  * 1. Initialize our various state variables.
1737  * 2. Ask the tape for its capabilities.
1738  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1739  * is chosen based on the recommendation which we received in step 2.
1740  *
1741  * Note that at this point ide.c already assigned us an irq, so that we can
1742  * queue requests here and wait for their completion.
1743  */
1744 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1745 {
1746         unsigned long t;
1747         int speed;
1748         int buffer_size;
1749         u16 *ctl = (u16 *)&tape->caps[12];
1750
1751         ide_debug_log(IDE_DBG_FUNC, "minor: %d", minor);
1752
1753         drive->pc_callback = ide_tape_callback;
1754
1755         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1756
1757         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1758                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1759                                  tape->name);
1760                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1761         }
1762
1763         /* Seagate Travan drives do not support DSC overlap. */
1764         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1765                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1766
1767         tape->minor = minor;
1768         tape->name[0] = 'h';
1769         tape->name[1] = 't';
1770         tape->name[2] = '0' + minor;
1771         tape->chrdev_dir = IDETAPE_DIR_NONE;
1772
1773         idetape_get_inquiry_results(drive);
1774         idetape_get_mode_sense_results(drive);
1775         ide_tape_get_bsize_from_bdesc(drive);
1776         tape->user_bs_factor = 1;
1777         tape->buffer_size = *ctl * tape->blk_size;
1778         while (tape->buffer_size > 0xffff) {
1779                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1780                 *ctl /= 2;
1781                 tape->buffer_size = *ctl * tape->blk_size;
1782         }
1783         buffer_size = tape->buffer_size;
1784
1785         /* select the "best" DSC read/write polling freq */
1786         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1787
1788         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1789
1790         /*
1791          * Ensure that the number we got makes sense; limit it within
1792          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1793          */
1794         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1795                                          IDETAPE_DSC_RW_MAX);
1796         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1797                 "%lums tDSC%s\n",
1798                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1799                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1800                 tape->buffer_size / 1024,
1801                 tape->best_dsc_rw_freq * 1000 / HZ,
1802                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1803
1804         ide_proc_register_driver(drive, tape->driver);
1805 }
1806
1807 static void ide_tape_remove(ide_drive_t *drive)
1808 {
1809         idetape_tape_t *tape = drive->driver_data;
1810
1811         ide_proc_unregister_driver(drive, tape->driver);
1812         device_del(&tape->dev);
1813         ide_unregister_region(tape->disk);
1814
1815         mutex_lock(&idetape_ref_mutex);
1816         put_device(&tape->dev);
1817         mutex_unlock(&idetape_ref_mutex);
1818 }
1819
1820 static void ide_tape_release(struct device *dev)
1821 {
1822         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1823         ide_drive_t *drive = tape->drive;
1824         struct gendisk *g = tape->disk;
1825
1826         BUG_ON(tape->valid);
1827
1828         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1829         drive->driver_data = NULL;
1830         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1831         device_destroy(idetape_sysfs_class,
1832                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1833         idetape_devs[tape->minor] = NULL;
1834         g->private_data = NULL;
1835         put_disk(g);
1836         kfree(tape);
1837 }
1838
1839 #ifdef CONFIG_IDE_PROC_FS
1840 static int idetape_name_proc_show(struct seq_file *m, void *v)
1841 {
1842         ide_drive_t     *drive = (ide_drive_t *) m->private;
1843         idetape_tape_t  *tape = drive->driver_data;
1844
1845         seq_printf(m, "%s\n", tape->name);
1846         return 0;
1847 }
1848
1849 static int idetape_name_proc_open(struct inode *inode, struct file *file)
1850 {
1851         return single_open(file, idetape_name_proc_show, PDE(inode)->data);
1852 }
1853
1854 static const struct file_operations idetape_name_proc_fops = {
1855         .owner          = THIS_MODULE,
1856         .open           = idetape_name_proc_open,
1857         .read           = seq_read,
1858         .llseek         = seq_lseek,
1859         .release        = single_release,
1860 };
1861
1862 static ide_proc_entry_t idetape_proc[] = {
1863         { "capacity",   S_IFREG|S_IRUGO,        &ide_capacity_proc_fops },
1864         { "name",       S_IFREG|S_IRUGO,        &idetape_name_proc_fops },
1865         {}
1866 };
1867
1868 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1869 {
1870         return idetape_proc;
1871 }
1872
1873 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1874 {
1875         return idetape_settings;
1876 }
1877 #endif
1878
1879 static int ide_tape_probe(ide_drive_t *);
1880
1881 static struct ide_driver idetape_driver = {
1882         .gen_driver = {
1883                 .owner          = THIS_MODULE,
1884                 .name           = "ide-tape",
1885                 .bus            = &ide_bus_type,
1886         },
1887         .probe                  = ide_tape_probe,
1888         .remove                 = ide_tape_remove,
1889         .version                = IDETAPE_VERSION,
1890         .do_request             = idetape_do_request,
1891 #ifdef CONFIG_IDE_PROC_FS
1892         .proc_entries           = ide_tape_proc_entries,
1893         .proc_devsets           = ide_tape_proc_devsets,
1894 #endif
1895 };
1896
1897 /* Our character device supporting functions, passed to register_chrdev. */
1898 static const struct file_operations idetape_fops = {
1899         .owner          = THIS_MODULE,
1900         .read           = idetape_chrdev_read,
1901         .write          = idetape_chrdev_write,
1902         .unlocked_ioctl = idetape_chrdev_ioctl,
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 int 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         return 0;
1931 }
1932
1933 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1934                         unsigned int cmd, unsigned long arg)
1935 {
1936         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1937         ide_drive_t *drive = tape->drive;
1938         int err;
1939
1940         mutex_lock(&ide_tape_mutex);
1941         err = generic_ide_ioctl(drive, bdev, cmd, arg);
1942         if (err == -EINVAL)
1943                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1944         mutex_unlock(&ide_tape_mutex);
1945
1946         return err;
1947 }
1948
1949 static const struct block_device_operations idetape_block_ops = {
1950         .owner          = THIS_MODULE,
1951         .open           = idetape_open,
1952         .release        = idetape_release,
1953         .ioctl          = idetape_ioctl,
1954 };
1955
1956 static int ide_tape_probe(ide_drive_t *drive)
1957 {
1958         idetape_tape_t *tape;
1959         struct gendisk *g;
1960         int minor;
1961
1962         ide_debug_log(IDE_DBG_FUNC, "enter");
1963
1964         if (!strstr(DRV_NAME, drive->driver_req))
1965                 goto failed;
1966
1967         if (drive->media != ide_tape)
1968                 goto failed;
1969
1970         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1971             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1972                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1973                                 " the driver\n", drive->name);
1974                 goto failed;
1975         }
1976         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1977         if (tape == NULL) {
1978                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1979                                 drive->name);
1980                 goto failed;
1981         }
1982
1983         g = alloc_disk(1 << PARTN_BITS);
1984         if (!g)
1985                 goto out_free_tape;
1986
1987         ide_init_disk(g, drive);
1988
1989         tape->dev.parent = &drive->gendev;
1990         tape->dev.release = ide_tape_release;
1991         dev_set_name(&tape->dev, dev_name(&drive->gendev));
1992
1993         if (device_register(&tape->dev))
1994                 goto out_free_disk;
1995
1996         tape->drive = drive;
1997         tape->driver = &idetape_driver;
1998         tape->disk = g;
1999
2000         g->private_data = &tape->driver;
2001
2002         drive->driver_data = tape;
2003
2004         mutex_lock(&idetape_ref_mutex);
2005         for (minor = 0; idetape_devs[minor]; minor++)
2006                 ;
2007         idetape_devs[minor] = tape;
2008         mutex_unlock(&idetape_ref_mutex);
2009
2010         idetape_setup(drive, tape, minor);
2011
2012         device_create(idetape_sysfs_class, &drive->gendev,
2013                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2014         device_create(idetape_sysfs_class, &drive->gendev,
2015                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2016                       "n%s", tape->name);
2017
2018         g->fops = &idetape_block_ops;
2019         ide_register_region(g);
2020
2021         return 0;
2022
2023 out_free_disk:
2024         put_disk(g);
2025 out_free_tape:
2026         kfree(tape);
2027 failed:
2028         return -ENODEV;
2029 }
2030
2031 static void __exit idetape_exit(void)
2032 {
2033         driver_unregister(&idetape_driver.gen_driver);
2034         class_destroy(idetape_sysfs_class);
2035         unregister_chrdev(IDETAPE_MAJOR, "ht");
2036 }
2037
2038 static int __init idetape_init(void)
2039 {
2040         int error = 1;
2041         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2042         if (IS_ERR(idetape_sysfs_class)) {
2043                 idetape_sysfs_class = NULL;
2044                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2045                 error = -EBUSY;
2046                 goto out;
2047         }
2048
2049         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2050                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2051                                 " interface\n");
2052                 error = -EBUSY;
2053                 goto out_free_class;
2054         }
2055
2056         error = driver_register(&idetape_driver.gen_driver);
2057         if (error)
2058                 goto out_free_driver;
2059
2060         return 0;
2061
2062 out_free_driver:
2063         driver_unregister(&idetape_driver.gen_driver);
2064 out_free_class:
2065         class_destroy(idetape_sysfs_class);
2066 out:
2067         return error;
2068 }
2069
2070 MODULE_ALIAS("ide:*m-tape*");
2071 module_init(idetape_init);
2072 module_exit(idetape_exit);
2073 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2074 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2075 MODULE_LICENSE("GPL");