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/uaccess.h>
  45 #include <linux/io.h>
  46 #include <asm/unaligned.h>
  47 #include <linux/mtio.h>
  48
  49 /* define to see debug info */
  50 #undef IDETAPE_DEBUG_LOG
  51
  52 #ifdef IDETAPE_DEBUG_LOG
  53 #define ide_debug_log(lvl, fmt, args...) __ide_debug_log(lvl, fmt, ## args)
  54 #else
  55 #define ide_debug_log(lvl, fmt, args...) do {} while (0)
  56 #endif
  57
  58 /**************************** Tunable parameters *****************************/
  59 /*
  60  * After each failed packet command we issue a request sense command and retry
  61  * the packet command IDETAPE_MAX_PC_RETRIES times.
  62  *
  63  * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
  64  */
  65 #define IDETAPE_MAX_PC_RETRIES          3
  66
  67 /*
  68  * The following parameter is used to select the point in the internal tape fifo
  69  * in which we will start to refill the buffer. Decreasing the following
  70  * parameter will improve the system's latency and interactive response, while
  71  * using a high value might improve system throughput.
  72  */
  73 #define IDETAPE_FIFO_THRESHOLD          2
  74
  75 /*
  76  * DSC polling parameters.
  77  *
  78  * Polling for DSC (a single bit in the status register) is a very important
  79  * function in ide-tape. There are two cases in which we poll for DSC:
  80  *
  81  * 1. Before a read/write packet command, to ensure that we can transfer data
  82  * from/to the tape's data buffers, without causing an actual media access.
  83  * In case the tape is not ready yet, we take out our request from the device
  84  * request queue, so that ide.c could service requests from the other device
  85  * on the same interface in the meantime.
  86  *
  87  * 2. After the successful initialization of a "media access packet command",
  88  * which is a command that can take a long time to complete (the interval can
  89  * range from several seconds to even an hour). Again, we postpone our request
  90  * in the middle to free the bus for the other device. The polling frequency
  91  * here should be lower than the read/write frequency since those media access
  92  * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
  93  * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
  94  * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
  95  *
  96  * We also set a timeout for the timer, in case something goes wrong. The
  97  * timeout should be longer then the maximum execution time of a tape operation.
  98  */
  99
 100 /* DSC timings. */
 101 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 102 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 103 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 104 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 105 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 106 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 107 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 108
 109 /*************************** End of tunable parameters ***********************/
 110
 111 /* tape directions */
 112 enum {
 113         IDETAPE_DIR_NONE  = (1 << 0),
 114         IDETAPE_DIR_READ  = (1 << 1),
 115         IDETAPE_DIR_WRITE = (1 << 2),
 116 };
 117
 118 /* Tape door status */
 119 #define DOOR_UNLOCKED                   0
 120 #define DOOR_LOCKED                     1
 121 #define DOOR_EXPLICITLY_LOCKED          2
 122
 123 /* Some defines for the SPACE command */
 124 #define IDETAPE_SPACE_OVER_FILEMARK     1
 125 #define IDETAPE_SPACE_TO_EOD            3
 126
 127 /* Some defines for the LOAD UNLOAD command */
 128 #define IDETAPE_LU_LOAD_MASK            1
 129 #define IDETAPE_LU_RETENSION_MASK       2
 130 #define IDETAPE_LU_EOT_MASK             4
 131
 132 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
 133 #define IDETAPE_BLOCK_DESCRIPTOR        0
 134 #define IDETAPE_CAPABILITIES_PAGE       0x2a
 135
 136 /*
 137  * Most of our global data which we need to save even as we leave the driver due
 138  * to an interrupt or a timer event is stored in the struct defined below.
 139  */
 140 typedef struct ide_tape_obj {
 141         ide_drive_t             *drive;
 142         struct ide_driver       *driver;
 143         struct gendisk          *disk;
 144         struct device           dev;
 145
 146         /* used by REQ_IDETAPE_{READ,WRITE} requests */
 147         struct ide_atapi_pc queued_pc;
 148
 149         /*
 150          * DSC polling variables.
 151          *
 152          * While polling for DSC we use postponed_rq to postpone the current
 153          * request so that ide.c will be able to service pending requests on the
 154          * other device. Note that at most we will have only one DSC (usually
 155          * data transfer) request in the device request queue.
 156          */
 157         bool postponed_rq;
 158
 159         /* The time in which we started polling for DSC */
 160         unsigned long dsc_polling_start;
 161         /* Timer used to poll for dsc */
 162         struct timer_list dsc_timer;
 163         /* Read/Write dsc polling frequency */
 164         unsigned long best_dsc_rw_freq;
 165         unsigned long dsc_poll_freq;
 166         unsigned long dsc_timeout;
 167
 168         /* Read position information */
 169         u8 partition;
 170         /* Current block */
 171         unsigned int first_frame;
 172
 173         /* Last error information */
 174         u8 sense_key, asc, ascq;
 175
 176         /* Character device operation */
 177         unsigned int minor;
 178         /* device name */
 179         char name[4];
 180         /* Current character device data transfer direction */
 181         u8 chrdev_dir;
 182
 183         /* tape block size, usually 512 or 1024 bytes */
 184         unsigned short blk_size;
 185         int user_bs_factor;
 186
 187         /* Copy of the tape's Capabilities and Mechanical Page */
 188         u8 caps[20];
 189
 190         /*
 191          * Active data transfer request parameters.
 192          *
 193          * At most, there is only one ide-tape originated data transfer request
 194          * in the device request queue. This allows ide.c to easily service
 195          * requests from the other device when we postpone our active request.
 196          */
 197
 198         /* Data buffer size chosen based on the tape's recommendation */
 199         int buffer_size;
 200         /* Staging buffer of buffer_size bytes */
 201         void *buf;
 202         /* The read/write cursor */
 203         void *cur;
 204         /* The number of valid bytes in buf */
 205         size_t valid;
 206
 207         /* Measures average tape speed */
 208         unsigned long avg_time;
 209         int avg_size;
 210         int avg_speed;
 211
 212         /* the door is currently locked */
 213         int door_locked;
 214         /* the tape hardware is write protected */
 215         char drv_write_prot;
 216         /* the tape is write protected (hardware or opened as read-only) */
 217         char write_prot;
 218 } idetape_tape_t;
 219
 220 static DEFINE_MUTEX(ide_tape_mutex);
 221 static DEFINE_MUTEX(idetape_ref_mutex);
 222
 223 static DEFINE_MUTEX(idetape_chrdev_mutex);
 224
 225 static struct class *idetape_sysfs_class;
 226
 227 static void ide_tape_release(struct device *);
 228
 229 static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
 230
 231 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk, bool cdev,
 232                                          unsigned int i)
 233 {
 234         struct ide_tape_obj *tape = NULL;
 235
 236         mutex_lock(&idetape_ref_mutex);
 237
 238         if (cdev)
 239                 tape = idetape_devs[i];
 240         else
 241                 tape = ide_drv_g(disk, ide_tape_obj);
 242
 243         if (tape) {
 244                 if (ide_device_get(tape->drive))
 245                         tape = NULL;
 246                 else
 247                         get_device(&tape->dev);
 248         }
 249
 250         mutex_unlock(&idetape_ref_mutex);
 251         return tape;
 252 }
 253
 254 static void ide_tape_put(struct ide_tape_obj *tape)
 255 {
 256         ide_drive_t *drive = tape->drive;
 257
 258         mutex_lock(&idetape_ref_mutex);
 259         put_device(&tape->dev);
 260         ide_device_put(drive);
 261         mutex_unlock(&idetape_ref_mutex);
 262 }
 263
 264 /*
 265  * called on each failed packet command retry to analyze the request sense. We
 266  * currently do not utilize this information.
 267  */
 268 static void idetape_analyze_error(ide_drive_t *drive)
 269 {
 270         idetape_tape_t *tape = drive->driver_data;
 271         struct ide_atapi_pc *pc = drive->failed_pc;
 272         struct request *rq = drive->hwif->rq;
 273         u8 *sense = bio_data(rq->bio);
 274
 275         tape->sense_key = sense[2] & 0xF;
 276         tape->asc       = sense[12];
 277         tape->ascq      = sense[13];
 278
 279         ide_debug_log(IDE_DBG_FUNC,
 280                       "cmd: 0x%x, sense key = %x, asc = %x, ascq = %x",
 281                       rq->cmd[0], tape->sense_key, tape->asc, tape->ascq);
 282
 283         /* correct remaining bytes to transfer */
 284         if (pc->flags & PC_FLAG_DMA_ERROR)
 285                 rq->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
 286
 287         /*
 288          * If error was the result of a zero-length read or write command,
 289          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
 290          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
 291          */
 292         if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
 293             /* length == 0 */
 294             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
 295                 if (tape->sense_key == 5) {
 296                         /* don't report an error, everything's ok */
 297                         pc->error = 0;
 298                         /* don't retry read/write */
 299                         pc->flags |= PC_FLAG_ABORT;
 300                 }
 301         }
 302         if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
 303                 pc->error = IDE_DRV_ERROR_FILEMARK;
 304                 pc->flags |= PC_FLAG_ABORT;
 305         }
 306         if (pc->c[0] == WRITE_6) {
 307                 if ((sense[2] & 0x40) || (tape->sense_key == 0xd
 308                      && tape->asc == 0x0 && tape->ascq == 0x2)) {
 309                         pc->error = IDE_DRV_ERROR_EOD;
 310                         pc->flags |= PC_FLAG_ABORT;
 311                 }
 312         }
 313         if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 314                 if (tape->sense_key == 8) {
 315                         pc->error = IDE_DRV_ERROR_EOD;
 316                         pc->flags |= PC_FLAG_ABORT;
 317                 }
 318                 if (!(pc->flags & PC_FLAG_ABORT) &&
 319                     (blk_rq_bytes(rq) - rq->resid_len))
 320                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
 321         }
 322 }
 323
 324 static void ide_tape_handle_dsc(ide_drive_t *);
 325
 326 static int ide_tape_callback(ide_drive_t *drive, int dsc)
 327 {
 328         idetape_tape_t *tape = drive->driver_data;
 329         struct ide_atapi_pc *pc = drive->pc;
 330         struct request *rq = drive->hwif->rq;
 331         int uptodate = pc->error ? 0 : 1;
 332         int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 333
 334         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc: %d, err: %d", rq->cmd[0],
 335                       dsc, err);
 336
 337         if (dsc)
 338                 ide_tape_handle_dsc(drive);
 339
 340         if (drive->failed_pc == pc)
 341                 drive->failed_pc = NULL;
 342
 343         if (pc->c[0] == REQUEST_SENSE) {
 344                 if (uptodate)
 345                         idetape_analyze_error(drive);
 346                 else
 347                         printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
 348                                         "itself - Aborting request!\n");
 349         } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 350                 unsigned int blocks =
 351                         (blk_rq_bytes(rq) - rq->resid_len) / tape->blk_size;
 352
 353                 tape->avg_size += blocks * tape->blk_size;
 354
 355                 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
 356                         tape->avg_speed = tape->avg_size * HZ /
 357                                 (jiffies - tape->avg_time) / 1024;
 358                         tape->avg_size = 0;
 359                         tape->avg_time = jiffies;
 360                 }
 361
 362                 tape->first_frame += blocks;
 363
 364                 if (pc->error) {
 365                         uptodate = 0;
 366                         err = pc->error;
 367                 }
 368         }
 369         rq->errors = err;
 370
 371         return uptodate;
 372 }
 373
 374 /*
 375  * Postpone the current request so that ide.c will be able to service requests
 376  * from another device on the same port while we are polling for DSC.
 377  */
 378 static void ide_tape_stall_queue(ide_drive_t *drive)
 379 {
 380         idetape_tape_t *tape = drive->driver_data;
 381
 382         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc_poll_freq: %lu",
 383                       drive->hwif->rq->cmd[0], tape->dsc_poll_freq);
 384
 385         tape->postponed_rq = true;
 386
 387         ide_stall_queue(drive, tape->dsc_poll_freq);
 388 }
 389
 390 static void ide_tape_handle_dsc(ide_drive_t *drive)
 391 {
 392         idetape_tape_t *tape = drive->driver_data;
 393
 394         /* Media access command */
 395         tape->dsc_polling_start = jiffies;
 396         tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
 397         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
 398         /* Allow ide.c to handle other requests */
 399         ide_tape_stall_queue(drive);
 400 }
 401
 402 /*
 403  * Packet Command Interface
 404  *
 405  * The current Packet Command is available in drive->pc, and will not change
 406  * until we finish handling it. Each packet command is associated with a
 407  * callback function that will be called when the command is finished.
 408  *
 409  * The handling will be done in three stages:
 410  *
 411  * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
 412  * the interrupt handler to ide_pc_intr.
 413  *
 414  * 2. On each interrupt, ide_pc_intr will be called. This step will be
 415  * repeated until the device signals us that no more interrupts will be issued.
 416  *
 417  * 3. ATAPI Tape media access commands have immediate status with a delayed
 418  * process. In case of a successful initiation of a media access packet command,
 419  * the DSC bit will be set when the actual execution of the command is finished.
 420  * Since the tape drive will not issue an interrupt, we have to poll for this
 421  * event. In this case, we define the request as "low priority request" by
 422  * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 423  * exit the driver.
 424  *
 425  * ide.c will then give higher priority to requests which originate from the
 426  * other device, until will change rq_status to RQ_ACTIVE.
 427  *
 428  * 4. When the packet command is finished, it will be checked for errors.
 429  *
 430  * 5. In case an error was found, we queue a request sense packet command in
 431  * front of the request queue and retry the operation up to
 432  * IDETAPE_MAX_PC_RETRIES times.
 433  *
 434  * 6. In case no error was found, or we decided to give up and not to retry
 435  * again, the callback function will be called and then we will handle the next
 436  * request.
 437  */
 438
 439 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 440                                          struct ide_cmd *cmd,
 441                                          struct ide_atapi_pc *pc)
 442 {
 443         idetape_tape_t *tape = drive->driver_data;
 444         struct request *rq = drive->hwif->rq;
 445
 446         if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
 447                 drive->failed_pc = pc;
 448
 449         /* Set the current packet command */
 450         drive->pc = pc;
 451
 452         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
 453                 (pc->flags & PC_FLAG_ABORT)) {
 454
 455                 /*
 456                  * We will "abort" retrying a packet command in case legitimate
 457                  * error code was received (crossing a filemark, or end of the
 458                  * media, for example).
 459                  */
 460                 if (!(pc->flags & PC_FLAG_ABORT)) {
 461                         if (!(pc->c[0] == TEST_UNIT_READY &&
 462                               tape->sense_key == 2 && tape->asc == 4 &&
 463                              (tape->ascq == 1 || tape->ascq == 8))) {
 464                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
 465                                                 "pc = %2x, key = %2x, "
 466                                                 "asc = %2x, ascq = %2x\n",
 467                                                 tape->name, pc->c[0],
 468                                                 tape->sense_key, tape->asc,
 469                                                 tape->ascq);
 470                         }
 471                         /* Giving up */
 472                         pc->error = IDE_DRV_ERROR_GENERAL;
 473                 }
 474
 475                 drive->failed_pc = NULL;
 476                 drive->pc_callback(drive, 0);
 477                 ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
 478                 return ide_stopped;
 479         }
 480         ide_debug_log(IDE_DBG_SENSE, "retry #%d, cmd: 0x%02x", pc->retries,
 481                       pc->c[0]);
 482
 483         pc->retries++;
 484
 485         return ide_issue_pc(drive, cmd);
 486 }
 487
 488 /* A mode sense command is used to "sense" tape parameters. */
 489 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 490 {
 491         ide_init_pc(pc);
 492         pc->c[0] = MODE_SENSE;
 493         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
 494                 /* DBD = 1 - Don't return block descriptors */
 495                 pc->c[1] = 8;
 496         pc->c[2] = page_code;
 497         /*
 498          * Changed pc->c[3] to 0 (255 will at best return unused info).
 499          *
 500          * For SCSI this byte is defined as subpage instead of high byte
 501          * of length and some IDE drives seem to interpret it this way
 502          * and return an error when 255 is used.
 503          */
 504         pc->c[3] = 0;
 505         /* We will just discard data in that case */
 506         pc->c[4] = 255;
 507         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
 508                 pc->req_xfer = 12;
 509         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
 510                 pc->req_xfer = 24;
 511         else
 512                 pc->req_xfer = 50;
 513 }
 514
 515 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 516 {
 517         ide_hwif_t *hwif = drive->hwif;
 518         idetape_tape_t *tape = drive->driver_data;
 519         struct ide_atapi_pc *pc = drive->pc;
 520         u8 stat;
 521
 522         stat = hwif->tp_ops->read_status(hwif);
 523
 524         if (stat & ATA_DSC) {
 525                 if (stat & ATA_ERR) {
 526                         /* Error detected */
 527                         if (pc->c[0] != TEST_UNIT_READY)
 528                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
 529                                                 tape->name);
 530                         /* Retry operation */
 531                         ide_retry_pc(drive);
 532                         return ide_stopped;
 533                 }
 534                 pc->error = 0;
 535         } else {
 536                 pc->error = IDE_DRV_ERROR_GENERAL;
 537                 drive->failed_pc = NULL;
 538         }
 539         drive->pc_callback(drive, 0);
 540         return ide_stopped;
 541 }
 542
 543 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
 544                                    struct ide_atapi_pc *pc, struct request *rq,
 545                                    u8 opcode)
 546 {
 547         unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
 548
 549         ide_init_pc(pc);
 550         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
 551         pc->c[1] = 1;
 552
 553         if (blk_rq_bytes(rq) == tape->buffer_size)
 554                 pc->flags |= PC_FLAG_DMA_OK;
 555
 556         if (opcode == READ_6)
 557                 pc->c[0] = READ_6;
 558         else if (opcode == WRITE_6) {
 559                 pc->c[0] = WRITE_6;
 560                 pc->flags |= PC_FLAG_WRITING;
 561         }
 562
 563         memcpy(rq->cmd, pc->c, 12);
 564 }
 565
 566 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 567                                           struct request *rq, sector_t block)
 568 {
 569         ide_hwif_t *hwif = drive->hwif;
 570         idetape_tape_t *tape = drive->driver_data;
 571         struct ide_atapi_pc *pc = NULL;
 572         struct ide_cmd cmd;
 573         u8 stat;
 574
 575         ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, sector: %llu, nr_sectors: %u",
 576                       rq->cmd[0], (unsigned long long)blk_rq_pos(rq),
 577                       blk_rq_sectors(rq));
 578
 579         BUG_ON(!(rq->cmd_type == REQ_TYPE_SPECIAL ||
 580                  rq->cmd_type == REQ_TYPE_SENSE));
 581
 582         /* Retry a failed packet command */
 583         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 584                 pc = drive->failed_pc;
 585                 goto out;
 586         }
 587
 588         /*
 589          * If the tape is still busy, postpone our request and service
 590          * the other device meanwhile.
 591          */
 592         stat = hwif->tp_ops->read_status(hwif);
 593
 594         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 595             (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
 596                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 597
 598         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 599                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 600                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 601         }
 602
 603         if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
 604             !(stat & ATA_DSC)) {
 605                 if (!tape->postponed_rq) {
 606                         tape->dsc_polling_start = jiffies;
 607                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 608                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 609                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 610                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 611                                 tape->name);
 612                         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 613                                 idetape_media_access_finished(drive);
 614                                 return ide_stopped;
 615                         } else {
 616                                 return ide_do_reset(drive);
 617                         }
 618                 } else if (time_after(jiffies,
 619                                         tape->dsc_polling_start +
 620                                         IDETAPE_DSC_MA_THRESHOLD))
 621                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 622                 ide_tape_stall_queue(drive);
 623                 return ide_stopped;
 624         } else {
 625                 drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
 626                 tape->postponed_rq = false;
 627         }
 628
 629         if (rq->cmd[13] & REQ_IDETAPE_READ) {
 630                 pc = &tape->queued_pc;
 631                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 632                 goto out;
 633         }
 634         if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
 635                 pc = &tape->queued_pc;
 636                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 637                 goto out;
 638         }
 639         if (rq->cmd[13] & REQ_IDETAPE_PC1) {
 640                 pc = (struct ide_atapi_pc *)rq->special;
 641                 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
 642                 rq->cmd[13] |= REQ_IDETAPE_PC2;
 643                 goto out;
 644         }
 645         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 646                 idetape_media_access_finished(drive);
 647                 return ide_stopped;
 648         }
 649         BUG();
 650
 651 out:
 652         /* prepare sense request for this command */
 653         ide_prep_sense(drive, rq);
 654
 655         memset(&cmd, 0, sizeof(cmd));
 656
 657         if (rq_data_dir(rq))
 658                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 659
 660         cmd.rq = rq;
 661
 662         ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
 663         ide_map_sg(drive, &cmd);
 664
 665         return ide_tape_issue_pc(drive, &cmd, pc);
 666 }
 667
 668 /*
 669  * Write a filemark if write_filemark=1. Flush the device buffers without
 670  * writing a filemark otherwise.
 671  */
 672 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 673                 struct ide_atapi_pc *pc, int write_filemark)
 674 {
 675         ide_init_pc(pc);
 676         pc->c[0] = WRITE_FILEMARKS;
 677         pc->c[4] = write_filemark;
 678         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 679 }
 680
 681 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 682 {
 683         idetape_tape_t *tape = drive->driver_data;
 684         struct gendisk *disk = tape->disk;
 685         int load_attempted = 0;
 686
 687         /* Wait for the tape to become ready */
 688         set_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT), &drive->atapi_flags);
 689         timeout += jiffies;
 690         while (time_before(jiffies, timeout)) {
 691                 if (ide_do_test_unit_ready(drive, disk) == 0)
 692                         return 0;
 693                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 694                     || (tape->asc == 0x3A)) {
 695                         /* no media */
 696                         if (load_attempted)
 697                                 return -ENOMEDIUM;
 698                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 699                         load_attempted = 1;
 700                 /* not about to be ready */
 701                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 702                              (tape->ascq == 1 || tape->ascq == 8)))
 703                         return -EIO;
 704                 msleep(100);
 705         }
 706         return -EIO;
 707 }
 708
 709 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 710 {
 711         struct ide_tape_obj *tape = drive->driver_data;
 712         struct ide_atapi_pc pc;
 713         int rc;
 714
 715         idetape_create_write_filemark_cmd(drive, &pc, 0);
 716         rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
 717         if (rc)
 718                 return rc;
 719         idetape_wait_ready(drive, 60 * 5 * HZ);
 720         return 0;
 721 }
 722
 723 static int ide_tape_read_position(ide_drive_t *drive)
 724 {
 725         idetape_tape_t *tape = drive->driver_data;
 726         struct ide_atapi_pc pc;
 727         u8 buf[20];
 728
 729         ide_debug_log(IDE_DBG_FUNC, "enter");
 730
 731         /* prep cmd */
 732         ide_init_pc(&pc);
 733         pc.c[0] = READ_POSITION;
 734         pc.req_xfer = 20;
 735
 736         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
 737                 return -1;
 738
 739         if (!pc.error) {
 740                 ide_debug_log(IDE_DBG_FUNC, "BOP - %s",
 741                                 (buf[0] & 0x80) ? "Yes" : "No");
 742                 ide_debug_log(IDE_DBG_FUNC, "EOP - %s",
 743                                 (buf[0] & 0x40) ? "Yes" : "No");
 744
 745                 if (buf[0] & 0x4) {
 746                         printk(KERN_INFO "ide-tape: Block location is unknown"
 747                                          "to the tape\n");
 748                         clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 749                                   &drive->atapi_flags);
 750                         return -1;
 751                 } else {
 752                         ide_debug_log(IDE_DBG_FUNC, "Block Location: %u",
 753                                       be32_to_cpup((__be32 *)&buf[4]));
 754
 755                         tape->partition = buf[1];
 756                         tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
 757                         set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 758                                 &drive->atapi_flags);
 759                 }
 760         }
 761
 762         return tape->first_frame;
 763 }
 764
 765 static void idetape_create_locate_cmd(ide_drive_t *drive,
 766                 struct ide_atapi_pc *pc,
 767                 unsigned int block, u8 partition, int skip)
 768 {
 769         ide_init_pc(pc);
 770         pc->c[0] = POSITION_TO_ELEMENT;
 771         pc->c[1] = 2;
 772         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 773         pc->c[8] = partition;
 774         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 775 }
 776
 777 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 778 {
 779         idetape_tape_t *tape = drive->driver_data;
 780
 781         if (tape->chrdev_dir != IDETAPE_DIR_READ)
 782                 return;
 783
 784         clear_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
 785         tape->valid = 0;
 786         if (tape->buf != NULL) {
 787                 kfree(tape->buf);
 788                 tape->buf = NULL;
 789         }
 790
 791         tape->chrdev_dir = IDETAPE_DIR_NONE;
 792 }
 793
 794 /*
 795  * Position the tape to the requested block using the LOCATE packet command.
 796  * A READ POSITION command is then issued to check where we are positioned. Like
 797  * all higher level operations, we queue the commands at the tail of the request
 798  * queue and wait for their completion.
 799  */
 800 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 801                 u8 partition, int skip)
 802 {
 803         idetape_tape_t *tape = drive->driver_data;
 804         struct gendisk *disk = tape->disk;
 805         int ret;
 806         struct ide_atapi_pc pc;
 807
 808         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 809                 __ide_tape_discard_merge_buffer(drive);
 810         idetape_wait_ready(drive, 60 * 5 * HZ);
 811         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 812         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 813         if (ret)
 814                 return ret;
 815
 816         ret = ide_tape_read_position(drive);
 817         if (ret < 0)
 818                 return ret;
 819         return 0;
 820 }
 821
 822 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 823                                           int restore_position)
 824 {
 825         idetape_tape_t *tape = drive->driver_data;
 826         int seek, position;
 827
 828         __ide_tape_discard_merge_buffer(drive);
 829         if (restore_position) {
 830                 position = ide_tape_read_position(drive);
 831                 seek = position > 0 ? position : 0;
 832                 if (idetape_position_tape(drive, seek, 0, 0)) {
 833                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 834                                          " %s\n", tape->name, __func__);
 835                         return;
 836                 }
 837         }
 838 }
 839
 840 /*
 841  * Generate a read/write request for the block device interface and wait for it
 842  * to be serviced.
 843  */
 844 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 845 {
 846         idetape_tape_t *tape = drive->driver_data;
 847         struct request *rq;
 848         int ret;
 849
 850         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, size: %d", cmd, size);
 851
 852         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 853         BUG_ON(size < 0 || size % tape->blk_size);
 854
 855         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
 856         rq->cmd_type = REQ_TYPE_SPECIAL;
 857         rq->cmd[13] = cmd;
 858         rq->rq_disk = tape->disk;
 859         rq->__sector = tape->first_frame;
 860
 861         if (size) {
 862                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 863                                       __GFP_WAIT);
 864                 if (ret)
 865                         goto out_put;
 866         }
 867
 868         blk_execute_rq(drive->queue, tape->disk, rq, 0);
 869
 870         /* calculate the number of transferred bytes and update buffer state */
 871         size -= rq->resid_len;
 872         tape->cur = tape->buf;
 873         if (cmd == REQ_IDETAPE_READ)
 874                 tape->valid = size;
 875         else
 876                 tape->valid = 0;
 877
 878         ret = size;
 879         if (rq->errors == IDE_DRV_ERROR_GENERAL)
 880                 ret = -EIO;
 881 out_put:
 882         blk_put_request(rq);
 883         return ret;
 884 }
 885
 886 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 887 {
 888         ide_init_pc(pc);
 889         pc->c[0] = INQUIRY;
 890         pc->c[4] = 254;
 891         pc->req_xfer = 254;
 892 }
 893
 894 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 895                 struct ide_atapi_pc *pc)
 896 {
 897         ide_init_pc(pc);
 898         pc->c[0] = REZERO_UNIT;
 899         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 900 }
 901
 902 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 903 {
 904         ide_init_pc(pc);
 905         pc->c[0] = ERASE;
 906         pc->c[1] = 1;
 907         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 908 }
 909
 910 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 911 {
 912         ide_init_pc(pc);
 913         pc->c[0] = SPACE;
 914         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 915         pc->c[1] = cmd;
 916         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 917 }
 918
 919 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 920 {
 921         idetape_tape_t *tape = drive->driver_data;
 922
 923         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 924                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 925                                 " but we are not writing.\n");
 926                 return;
 927         }
 928         if (tape->buf) {
 929                 size_t aligned = roundup(tape->valid, tape->blk_size);
 930
 931                 memset(tape->cur, 0, aligned - tape->valid);
 932                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 933                 kfree(tape->buf);
 934                 tape->buf = NULL;
 935         }
 936         tape->chrdev_dir = IDETAPE_DIR_NONE;
 937 }
 938
 939 static int idetape_init_rw(ide_drive_t *drive, int dir)
 940 {
 941         idetape_tape_t *tape = drive->driver_data;
 942         int rc;
 943
 944         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 945
 946         if (tape->chrdev_dir == dir)
 947                 return 0;
 948
 949         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 950                 ide_tape_discard_merge_buffer(drive, 1);
 951         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 952                 ide_tape_flush_merge_buffer(drive);
 953                 idetape_flush_tape_buffers(drive);
 954         }
 955
 956         if (tape->buf || tape->valid) {
 957                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 958                 tape->valid = 0;
 959         }
 960
 961         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 962         if (!tape->buf)
 963                 return -ENOMEM;
 964         tape->chrdev_dir = dir;
 965         tape->cur = tape->buf;
 966
 967         /*
 968          * Issue a 0 rw command to ensure that DSC handshake is
 969          * switched from completion mode to buffer available mode.  No
 970          * point in issuing this if DSC overlap isn't supported, some
 971          * drives (Seagate STT3401A) will return an error.
 972          */
 973         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
 974                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
 975                                                   : REQ_IDETAPE_WRITE;
 976
 977                 rc = idetape_queue_rw_tail(drive, cmd, 0);
 978                 if (rc < 0) {
 979                         kfree(tape->buf);
 980                         tape->buf = NULL;
 981                         tape->chrdev_dir = IDETAPE_DIR_NONE;
 982                         return rc;
 983                 }
 984         }
 985
 986         return 0;
 987 }
 988
 989 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
 990 {
 991         idetape_tape_t *tape = drive->driver_data;
 992
 993         memset(tape->buf, 0, tape->buffer_size);
 994
 995         while (bcount) {
 996                 unsigned int count = min(tape->buffer_size, bcount);
 997
 998                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
 999                 bcount -= count;
1000         }
1001 }
1002
1003 /*
1004  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1005  * currently support only one partition.
1006  */
1007 static int idetape_rewind_tape(ide_drive_t *drive)
1008 {
1009         struct ide_tape_obj *tape = drive->driver_data;
1010         struct gendisk *disk = tape->disk;
1011         struct ide_atapi_pc pc;
1012         int ret;
1013
1014         ide_debug_log(IDE_DBG_FUNC, "enter");
1015
1016         idetape_create_rewind_cmd(drive, &pc);
1017         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1018         if (ret)
1019                 return ret;
1020
1021         ret = ide_tape_read_position(drive);
1022         if (ret < 0)
1023                 return ret;
1024         return 0;
1025 }
1026
1027 /* mtio.h compatible commands should be issued to the chrdev interface. */
1028 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1029                                 unsigned long arg)
1030 {
1031         idetape_tape_t *tape = drive->driver_data;
1032         void __user *argp = (void __user *)arg;
1033
1034         struct idetape_config {
1035                 int dsc_rw_frequency;
1036                 int dsc_media_access_frequency;
1037                 int nr_stages;
1038         } config;
1039
1040         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%04x", cmd);
1041
1042         switch (cmd) {
1043         case 0x0340:
1044                 if (copy_from_user(&config, argp, sizeof(config)))
1045                         return -EFAULT;
1046                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1047                 break;
1048         case 0x0350:
1049                 memset(&config, 0, sizeof(config));
1050                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1051                 config.nr_stages = 1;
1052                 if (copy_to_user(argp, &config, sizeof(config)))
1053                         return -EFAULT;
1054                 break;
1055         default:
1056                 return -EIO;
1057         }
1058         return 0;
1059 }
1060
1061 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1062                                         int mt_count)
1063 {
1064         idetape_tape_t *tape = drive->driver_data;
1065         struct gendisk *disk = tape->disk;
1066         struct ide_atapi_pc pc;
1067         int retval, count = 0;
1068         int sprev = !!(tape->caps[4] & 0x20);
1069
1070
1071         ide_debug_log(IDE_DBG_FUNC, "mt_op: %d, mt_count: %d", mt_op, mt_count);
1072
1073         if (mt_count == 0)
1074                 return 0;
1075         if (MTBSF == mt_op || MTBSFM == mt_op) {
1076                 if (!sprev)
1077                         return -EIO;
1078                 mt_count = -mt_count;
1079         }
1080
1081         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1082                 tape->valid = 0;
1083                 if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1084                                        &drive->atapi_flags))
1085                         ++count;
1086                 ide_tape_discard_merge_buffer(drive, 0);
1087         }
1088
1089         switch (mt_op) {
1090         case MTFSF:
1091         case MTBSF:
1092                 idetape_create_space_cmd(&pc, mt_count - count,
1093                                          IDETAPE_SPACE_OVER_FILEMARK);
1094                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1095         case MTFSFM:
1096         case MTBSFM:
1097                 if (!sprev)
1098                         return -EIO;
1099                 retval = idetape_space_over_filemarks(drive, MTFSF,
1100                                                       mt_count - count);
1101                 if (retval)
1102                         return retval;
1103                 count = (MTBSFM == mt_op ? 1 : -1);
1104                 return idetape_space_over_filemarks(drive, MTFSF, count);
1105         default:
1106                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1107                                 mt_op);
1108                 return -EIO;
1109         }
1110 }
1111
1112 /*
1113  * Our character device read / write functions.
1114  *
1115  * The tape is optimized to maximize throughput when it is transferring an
1116  * integral number of the "continuous transfer limit", which is a parameter of
1117  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1118  *
1119  * As of version 1.3 of the driver, the character device provides an abstract
1120  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1121  * same backup/restore procedure is supported. The driver will internally
1122  * convert the requests to the recommended transfer unit, so that an unmatch
1123  * between the user's block size to the recommended size will only result in a
1124  * (slightly) increased driver overhead, but will no longer hit performance.
1125  * This is not applicable to Onstream.
1126  */
1127 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1128                                    size_t count, loff_t *ppos)
1129 {
1130         struct ide_tape_obj *tape = file->private_data;
1131         ide_drive_t *drive = tape->drive;
1132         size_t done = 0;
1133         ssize_t ret = 0;
1134         int rc;
1135
1136         ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1137
1138         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1139                 if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1140                         if (count > tape->blk_size &&
1141                             (count % tape->blk_size) == 0)
1142                                 tape->user_bs_factor = count / tape->blk_size;
1143         }
1144
1145         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1146         if (rc < 0)
1147                 return rc;
1148
1149         while (done < count) {
1150                 size_t todo;
1151
1152                 /* refill if staging buffer is empty */
1153                 if (!tape->valid) {
1154                         /* If we are at a filemark, nothing more to read */
1155                         if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1156                                      &drive->atapi_flags))
1157                                 break;
1158                         /* read */
1159                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1160                                                   tape->buffer_size) <= 0)
1161                                 break;
1162                 }
1163
1164                 /* copy out */
1165                 todo = min_t(size_t, count - done, tape->valid);
1166                 if (copy_to_user(buf + done, tape->cur, todo))
1167                         ret = -EFAULT;
1168
1169                 tape->cur += todo;
1170                 tape->valid -= todo;
1171                 done += todo;
1172         }
1173
1174         if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1175                 idetape_space_over_filemarks(drive, MTFSF, 1);
1176                 return 0;
1177         }
1178
1179         return ret ? ret : done;
1180 }
1181
1182 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1183                                      size_t count, loff_t *ppos)
1184 {
1185         struct ide_tape_obj *tape = file->private_data;
1186         ide_drive_t *drive = tape->drive;
1187         size_t done = 0;
1188         ssize_t ret = 0;
1189         int rc;
1190
1191         /* The drive is write protected. */
1192         if (tape->write_prot)
1193                 return -EACCES;
1194
1195         ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1196
1197         /* Initialize write operation */
1198         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1199         if (rc < 0)
1200                 return rc;
1201
1202         while (done < count) {
1203                 size_t todo;
1204
1205                 /* flush if staging buffer is full */
1206                 if (tape->valid == tape->buffer_size &&
1207                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1208                                           tape->buffer_size) <= 0)
1209                         return rc;
1210
1211                 /* copy in */
1212                 todo = min_t(size_t, count - done,
1213                              tape->buffer_size - tape->valid);
1214                 if (copy_from_user(tape->cur, buf + done, todo))
1215                         ret = -EFAULT;
1216
1217                 tape->cur += todo;
1218                 tape->valid += todo;
1219                 done += todo;
1220         }
1221
1222         return ret ? ret : done;
1223 }
1224
1225 static int idetape_write_filemark(ide_drive_t *drive)
1226 {
1227         struct ide_tape_obj *tape = drive->driver_data;
1228         struct ide_atapi_pc pc;
1229
1230         /* Write a filemark */
1231         idetape_create_write_filemark_cmd(drive, &pc, 1);
1232         if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1233                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1234                 return -EIO;
1235         }
1236         return 0;
1237 }
1238
1239 /*
1240  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1241  * requested.
1242  *
1243  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1244  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1245  * usually not supported.
1246  *
1247  * The following commands are currently not supported:
1248  *
1249  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1250  * MT_ST_WRITE_THRESHOLD.
1251  */
1252 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1253 {
1254         idetape_tape_t *tape = drive->driver_data;
1255         struct gendisk *disk = tape->disk;
1256         struct ide_atapi_pc pc;
1257         int i, retval;
1258
1259         ide_debug_log(IDE_DBG_FUNC, "MTIOCTOP ioctl: mt_op: %d, mt_count: %d",
1260                       mt_op, mt_count);
1261
1262         switch (mt_op) {
1263         case MTFSF:
1264         case MTFSFM:
1265         case MTBSF:
1266         case MTBSFM:
1267                 if (!mt_count)
1268                         return 0;
1269                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1270         default:
1271                 break;
1272         }
1273
1274         switch (mt_op) {
1275         case MTWEOF:
1276                 if (tape->write_prot)
1277                         return -EACCES;
1278                 ide_tape_discard_merge_buffer(drive, 1);
1279                 for (i = 0; i < mt_count; i++) {
1280                         retval = idetape_write_filemark(drive);
1281                         if (retval)
1282                                 return retval;
1283                 }
1284                 return 0;
1285         case MTREW:
1286                 ide_tape_discard_merge_buffer(drive, 0);
1287                 if (idetape_rewind_tape(drive))
1288                         return -EIO;
1289                 return 0;
1290         case MTLOAD:
1291                 ide_tape_discard_merge_buffer(drive, 0);
1292                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1293         case MTUNLOAD:
1294         case MTOFFL:
1295                 /*
1296                  * If door is locked, attempt to unlock before
1297                  * attempting to eject.
1298                  */
1299                 if (tape->door_locked) {
1300                         if (!ide_set_media_lock(drive, disk, 0))
1301                                 tape->door_locked = DOOR_UNLOCKED;
1302                 }
1303                 ide_tape_discard_merge_buffer(drive, 0);
1304                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1305                 if (!retval)
1306                         clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1307                                   &drive->atapi_flags);
1308                 return retval;
1309         case MTNOP:
1310                 ide_tape_discard_merge_buffer(drive, 0);
1311                 return idetape_flush_tape_buffers(drive);
1312         case MTRETEN:
1313                 ide_tape_discard_merge_buffer(drive, 0);
1314                 return ide_do_start_stop(drive, disk,
1315                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1316         case MTEOM:
1317                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1318                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1319         case MTERASE:
1320                 (void)idetape_rewind_tape(drive);
1321                 idetape_create_erase_cmd(&pc);
1322                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1323         case MTSETBLK:
1324                 if (mt_count) {
1325                         if (mt_count < tape->blk_size ||
1326                             mt_count % tape->blk_size)
1327                                 return -EIO;
1328                         tape->user_bs_factor = mt_count / tape->blk_size;
1329                         clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1330                                   &drive->atapi_flags);
1331                 } else
1332                         set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1333                                 &drive->atapi_flags);
1334                 return 0;
1335         case MTSEEK:
1336                 ide_tape_discard_merge_buffer(drive, 0);
1337                 return idetape_position_tape(drive,
1338                         mt_count * tape->user_bs_factor, tape->partition, 0);
1339         case MTSETPART:
1340                 ide_tape_discard_merge_buffer(drive, 0);
1341                 return idetape_position_tape(drive, 0, mt_count, 0);
1342         case MTFSR:
1343         case MTBSR:
1344         case MTLOCK:
1345                 retval = ide_set_media_lock(drive, disk, 1);
1346                 if (retval)
1347                         return retval;
1348                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1349                 return 0;
1350         case MTUNLOCK:
1351                 retval = ide_set_media_lock(drive, disk, 0);
1352                 if (retval)
1353                         return retval;
1354                 tape->door_locked = DOOR_UNLOCKED;
1355                 return 0;
1356         default:
1357                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1358                                 mt_op);
1359                 return -EIO;
1360         }
1361 }
1362
1363 /*
1364  * Our character device ioctls. General mtio.h magnetic io commands are
1365  * supported here, and not in the corresponding block interface. Our own
1366  * ide-tape ioctls are supported on both interfaces.
1367  */
1368 static long do_idetape_chrdev_ioctl(struct file *file,
1369                                 unsigned int cmd, unsigned long arg)
1370 {
1371         struct ide_tape_obj *tape = file->private_data;
1372         ide_drive_t *drive = tape->drive;
1373         struct mtop mtop;
1374         struct mtget mtget;
1375         struct mtpos mtpos;
1376         int block_offset = 0, position = tape->first_frame;
1377         void __user *argp = (void __user *)arg;
1378
1379         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x", cmd);
1380
1381         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1382                 ide_tape_flush_merge_buffer(drive);
1383                 idetape_flush_tape_buffers(drive);
1384         }
1385         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1386                 block_offset = tape->valid /
1387                         (tape->blk_size * tape->user_bs_factor);
1388                 position = ide_tape_read_position(drive);
1389                 if (position < 0)
1390                         return -EIO;
1391         }
1392         switch (cmd) {
1393         case MTIOCTOP:
1394                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1395                         return -EFAULT;
1396                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1397         case MTIOCGET:
1398                 memset(&mtget, 0, sizeof(struct mtget));
1399                 mtget.mt_type = MT_ISSCSI2;
1400                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1401                 mtget.mt_dsreg =
1402                         ((tape->blk_size * tape->user_bs_factor)
1403                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1404
1405                 if (tape->drv_write_prot)
1406                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1407
1408                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1409                         return -EFAULT;
1410                 return 0;
1411         case MTIOCPOS:
1412                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1413                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1414                         return -EFAULT;
1415                 return 0;
1416         default:
1417                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1418                         ide_tape_discard_merge_buffer(drive, 1);
1419                 return idetape_blkdev_ioctl(drive, cmd, arg);
1420         }
1421 }
1422
1423 static long idetape_chrdev_ioctl(struct file *file,
1424                                 unsigned int cmd, unsigned long arg)
1425 {
1426         long ret;
1427         mutex_lock(&ide_tape_mutex);
1428         ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1429         mutex_unlock(&ide_tape_mutex);
1430         return ret;
1431 }
1432
1433 /*
1434  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1435  * block size with the reported value.
1436  */
1437 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1438 {
1439         idetape_tape_t *tape = drive->driver_data;
1440         struct ide_atapi_pc pc;
1441         u8 buf[12];
1442
1443         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1444         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1445                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1446                 if (tape->blk_size == 0) {
1447                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1448                                             "block size, assuming 32k\n");
1449                         tape->blk_size = 32768;
1450                 }
1451                 return;
1452         }
1453         tape->blk_size = (buf[4 + 5] << 16) +
1454                                 (buf[4 + 6] << 8)  +
1455                                  buf[4 + 7];
1456         tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1457
1458         ide_debug_log(IDE_DBG_FUNC, "blk_size: %d, write_prot: %d",
1459                       tape->blk_size, tape->drv_write_prot);
1460 }
1461
1462 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1463 {
1464         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1465         ide_drive_t *drive;
1466         idetape_tape_t *tape;
1467         int retval;
1468
1469         if (i >= MAX_HWIFS * MAX_DRIVES)
1470                 return -ENXIO;
1471
1472         mutex_lock(&idetape_chrdev_mutex);
1473
1474         tape = ide_tape_get(NULL, true, i);
1475         if (!tape) {
1476                 mutex_unlock(&idetape_chrdev_mutex);
1477                 return -ENXIO;
1478         }
1479
1480         drive = tape->drive;
1481         filp->private_data = tape;
1482
1483         ide_debug_log(IDE_DBG_FUNC, "enter");
1484
1485         /*
1486          * We really want to do nonseekable_open(inode, filp); here, but some
1487          * versions of tar incorrectly call lseek on tapes and bail out if that
1488          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1489          */
1490         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1491
1492
1493         if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1494                 retval = -EBUSY;
1495                 goto out_put_tape;
1496         }
1497
1498         retval = idetape_wait_ready(drive, 60 * HZ);
1499         if (retval) {
1500                 clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1501                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1502                 goto out_put_tape;
1503         }
1504
1505         ide_tape_read_position(drive);
1506         if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1507                 (void)idetape_rewind_tape(drive);
1508
1509         /* Read block size and write protect status from drive. */
1510         ide_tape_get_bsize_from_bdesc(drive);
1511
1512         /* Set write protect flag if device is opened as read-only. */
1513         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1514                 tape->write_prot = 1;
1515         else
1516                 tape->write_prot = tape->drv_write_prot;
1517
1518         /* Make sure drive isn't write protected if user wants to write. */
1519         if (tape->write_prot) {
1520                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1521                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1522                         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1523                         retval = -EROFS;
1524                         goto out_put_tape;
1525                 }
1526         }
1527
1528         /* Lock the tape drive door so user can't eject. */
1529         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1530                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1531                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1532                                 tape->door_locked = DOOR_LOCKED;
1533                 }
1534         }
1535         mutex_unlock(&idetape_chrdev_mutex);
1536
1537         return 0;
1538
1539 out_put_tape:
1540         ide_tape_put(tape);
1541
1542         mutex_unlock(&idetape_chrdev_mutex);
1543
1544         return retval;
1545 }
1546
1547 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1548 {
1549         idetape_tape_t *tape = drive->driver_data;
1550
1551         ide_tape_flush_merge_buffer(drive);
1552         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1553         if (tape->buf != NULL) {
1554                 idetape_pad_zeros(drive, tape->blk_size *
1555                                 (tape->user_bs_factor - 1));
1556                 kfree(tape->buf);
1557                 tape->buf = NULL;
1558         }
1559         idetape_write_filemark(drive);
1560         idetape_flush_tape_buffers(drive);
1561         idetape_flush_tape_buffers(drive);
1562 }
1563
1564 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1565 {
1566         struct ide_tape_obj *tape = filp->private_data;
1567         ide_drive_t *drive = tape->drive;
1568         unsigned int minor = iminor(inode);
1569
1570         mutex_lock(&idetape_chrdev_mutex);
1571
1572         tape = drive->driver_data;
1573
1574         ide_debug_log(IDE_DBG_FUNC, "enter");
1575
1576         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1577                 idetape_write_release(drive, minor);
1578         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1579                 if (minor < 128)
1580                         ide_tape_discard_merge_buffer(drive, 1);
1581         }
1582
1583         if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1584                                     &drive->atapi_flags))
1585                 (void) idetape_rewind_tape(drive);
1586
1587         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1588                 if (tape->door_locked == DOOR_LOCKED) {
1589                         if (!ide_set_media_lock(drive, tape->disk, 0))
1590                                 tape->door_locked = DOOR_UNLOCKED;
1591                 }
1592         }
1593         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1594         ide_tape_put(tape);
1595
1596         mutex_unlock(&idetape_chrdev_mutex);
1597
1598         return 0;
1599 }
1600
1601 static void idetape_get_inquiry_results(ide_drive_t *drive)
1602 {
1603         idetape_tape_t *tape = drive->driver_data;
1604         struct ide_atapi_pc pc;
1605         u8 pc_buf[256];
1606         char fw_rev[4], vendor_id[8], product_id[16];
1607
1608         idetape_create_inquiry_cmd(&pc);
1609         if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1610                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1611                                 tape->name);
1612                 return;
1613         }
1614         memcpy(vendor_id, &pc_buf[8], 8);
1615         memcpy(product_id, &pc_buf[16], 16);
1616         memcpy(fw_rev, &pc_buf[32], 4);
1617
1618         ide_fixstring(vendor_id, 8, 0);
1619         ide_fixstring(product_id, 16, 0);
1620         ide_fixstring(fw_rev, 4, 0);
1621
1622         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1623                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1624 }
1625
1626 /*
1627  * Ask the tape about its various parameters. In particular, we will adjust our
1628  * data transfer buffer size to the recommended value as returned by the tape.
1629  */
1630 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1631 {
1632         idetape_tape_t *tape = drive->driver_data;
1633         struct ide_atapi_pc pc;
1634         u8 buf[24], *caps;
1635         u8 speed, max_speed;
1636
1637         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1638         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1639                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1640                                 " some default values\n");
1641                 tape->blk_size = 512;
1642                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1643                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1644                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1645                 return;
1646         }
1647         caps = buf + 4 + buf[3];
1648
1649         /* convert to host order and save for later use */
1650         speed = be16_to_cpup((__be16 *)&caps[14]);
1651         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1652
1653         *(u16 *)&caps[8] = max_speed;
1654         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1655         *(u16 *)&caps[14] = speed;
1656         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1657
1658         if (!speed) {
1659                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1660                                 "(assuming 650KB/sec)\n", drive->name);
1661                 *(u16 *)&caps[14] = 650;
1662         }
1663         if (!max_speed) {
1664                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1665                                 "(assuming 650KB/sec)\n", drive->name);
1666                 *(u16 *)&caps[8] = 650;
1667         }
1668
1669         memcpy(&tape->caps, caps, 20);
1670
1671         /* device lacks locking support according to capabilities page */
1672         if ((caps[6] & 1) == 0)
1673                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1674
1675         if (caps[7] & 0x02)
1676                 tape->blk_size = 512;
1677         else if (caps[7] & 0x04)
1678                 tape->blk_size = 1024;
1679 }
1680
1681 #ifdef CONFIG_IDE_PROC_FS
1682 #define ide_tape_devset_get(name, field) \
1683 static int get_##name(ide_drive_t *drive) \
1684 { \
1685         idetape_tape_t *tape = drive->driver_data; \
1686         return tape->field; \
1687 }
1688
1689 #define ide_tape_devset_set(name, field) \
1690 static int set_##name(ide_drive_t *drive, int arg) \
1691 { \
1692         idetape_tape_t *tape = drive->driver_data; \
1693         tape->field = arg; \
1694         return 0; \
1695 }
1696
1697 #define ide_tape_devset_rw_field(_name, _field) \
1698 ide_tape_devset_get(_name, _field) \
1699 ide_tape_devset_set(_name, _field) \
1700 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1701
1702 #define ide_tape_devset_r_field(_name, _field) \
1703 ide_tape_devset_get(_name, _field) \
1704 IDE_DEVSET(_name, 0, get_##_name, NULL)
1705
1706 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1707 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1708 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1709 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1710
1711 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1712
1713 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1714
1715 ide_tape_devset_r_field(avg_speed, avg_speed);
1716 ide_tape_devset_r_field(speed, caps[14]);
1717 ide_tape_devset_r_field(buffer, caps[16]);
1718 ide_tape_devset_r_field(buffer_size, buffer_size);
1719
1720 static const struct ide_proc_devset idetape_settings[] = {
1721         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1722         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1723         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1724         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1725         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1726         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1727                                         mulf_tdsc, divf_tdsc),
1728         { NULL },
1729 };
1730 #endif
1731
1732 /*
1733  * The function below is called to:
1734  *
1735  * 1. Initialize our various state variables.
1736  * 2. Ask the tape for its capabilities.
1737  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1738  * is chosen based on the recommendation which we received in step 2.
1739  *
1740  * Note that at this point ide.c already assigned us an irq, so that we can
1741  * queue requests here and wait for their completion.
1742  */
1743 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1744 {
1745         unsigned long t;
1746         int speed;
1747         int buffer_size;
1748         u16 *ctl = (u16 *)&tape->caps[12];
1749
1750         ide_debug_log(IDE_DBG_FUNC, "minor: %d", minor);
1751
1752         drive->pc_callback = ide_tape_callback;
1753
1754         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1755
1756         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1757                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1758                                  tape->name);
1759                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1760         }
1761
1762         /* Seagate Travan drives do not support DSC overlap. */
1763         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1764                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1765
1766         tape->minor = minor;
1767         tape->name[0] = 'h';
1768         tape->name[1] = 't';
1769         tape->name[2] = '0' + minor;
1770         tape->chrdev_dir = IDETAPE_DIR_NONE;
1771
1772         idetape_get_inquiry_results(drive);
1773         idetape_get_mode_sense_results(drive);
1774         ide_tape_get_bsize_from_bdesc(drive);
1775         tape->user_bs_factor = 1;
1776         tape->buffer_size = *ctl * tape->blk_size;
1777         while (tape->buffer_size > 0xffff) {
1778                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1779                 *ctl /= 2;
1780                 tape->buffer_size = *ctl * tape->blk_size;
1781         }
1782         buffer_size = tape->buffer_size;
1783
1784         /* select the "best" DSC read/write polling freq */
1785         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1786
1787         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1788
1789         /*
1790          * Ensure that the number we got makes sense; limit it within
1791          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1792          */
1793         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1794                                          IDETAPE_DSC_RW_MAX);
1795         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1796                 "%lums tDSC%s\n",
1797                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1798                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1799                 tape->buffer_size / 1024,
1800                 tape->best_dsc_rw_freq * 1000 / HZ,
1801                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1802
1803         ide_proc_register_driver(drive, tape->driver);
1804 }
1805
1806 static void ide_tape_remove(ide_drive_t *drive)
1807 {
1808         idetape_tape_t *tape = drive->driver_data;
1809
1810         ide_proc_unregister_driver(drive, tape->driver);
1811         device_del(&tape->dev);
1812         ide_unregister_region(tape->disk);
1813
1814         mutex_lock(&idetape_ref_mutex);
1815         put_device(&tape->dev);
1816         mutex_unlock(&idetape_ref_mutex);
1817 }
1818
1819 static void ide_tape_release(struct device *dev)
1820 {
1821         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1822         ide_drive_t *drive = tape->drive;
1823         struct gendisk *g = tape->disk;
1824
1825         BUG_ON(tape->valid);
1826
1827         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1828         drive->driver_data = NULL;
1829         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1830         device_destroy(idetape_sysfs_class,
1831                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1832         idetape_devs[tape->minor] = NULL;
1833         g->private_data = NULL;
1834         put_disk(g);
1835         kfree(tape);
1836 }
1837
1838 #ifdef CONFIG_IDE_PROC_FS
1839 static int idetape_name_proc_show(struct seq_file *m, void *v)
1840 {
1841         ide_drive_t     *drive = (ide_drive_t *) m->private;
1842         idetape_tape_t  *tape = drive->driver_data;
1843
1844         seq_printf(m, "%s\n", tape->name);
1845         return 0;
1846 }
1847
1848 static int idetape_name_proc_open(struct inode *inode, struct file *file)
1849 {
1850         return single_open(file, idetape_name_proc_show, PDE_DATA(inode));
1851 }
1852
1853 static const struct file_operations idetape_name_proc_fops = {
1854         .owner          = THIS_MODULE,
1855         .open           = idetape_name_proc_open,
1856         .read           = seq_read,
1857         .llseek         = seq_lseek,
1858         .release        = single_release,
1859 };
1860
1861 static ide_proc_entry_t idetape_proc[] = {
1862         { "capacity",   S_IFREG|S_IRUGO,        &ide_capacity_proc_fops },
1863         { "name",       S_IFREG|S_IRUGO,        &idetape_name_proc_fops },
1864         {}
1865 };
1866
1867 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1868 {
1869         return idetape_proc;
1870 }
1871
1872 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1873 {
1874         return idetape_settings;
1875 }
1876 #endif
1877
1878 static int ide_tape_probe(ide_drive_t *);
1879
1880 static struct ide_driver idetape_driver = {
1881         .gen_driver = {
1882                 .owner          = THIS_MODULE,
1883                 .name           = "ide-tape",
1884                 .bus            = &ide_bus_type,
1885         },
1886         .probe                  = ide_tape_probe,
1887         .remove                 = ide_tape_remove,
1888         .version                = IDETAPE_VERSION,
1889         .do_request             = idetape_do_request,
1890 #ifdef CONFIG_IDE_PROC_FS
1891         .proc_entries           = ide_tape_proc_entries,
1892         .proc_devsets           = ide_tape_proc_devsets,
1893 #endif
1894 };
1895
1896 /* Our character device supporting functions, passed to register_chrdev. */
1897 static const struct file_operations idetape_fops = {
1898         .owner          = THIS_MODULE,
1899         .read           = idetape_chrdev_read,
1900         .write          = idetape_chrdev_write,
1901         .unlocked_ioctl = idetape_chrdev_ioctl,
1902         .open           = idetape_chrdev_open,
1903         .release        = idetape_chrdev_release,
1904         .llseek         = noop_llseek,
1905 };
1906
1907 static int idetape_open(struct block_device *bdev, fmode_t mode)
1908 {
1909         struct ide_tape_obj *tape;
1910
1911         mutex_lock(&ide_tape_mutex);
1912         tape = ide_tape_get(bdev->bd_disk, false, 0);
1913         mutex_unlock(&ide_tape_mutex);
1914
1915         if (!tape)
1916                 return -ENXIO;
1917
1918         return 0;
1919 }
1920
1921 static void idetape_release(struct gendisk *disk, fmode_t mode)
1922 {
1923         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1924
1925         mutex_lock(&ide_tape_mutex);
1926         ide_tape_put(tape);
1927         mutex_unlock(&ide_tape_mutex);
1928 }
1929
1930 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1931                         unsigned int cmd, unsigned long arg)
1932 {
1933         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1934         ide_drive_t *drive = tape->drive;
1935         int err;
1936
1937         mutex_lock(&ide_tape_mutex);
1938         err = generic_ide_ioctl(drive, bdev, cmd, arg);
1939         if (err == -EINVAL)
1940                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1941         mutex_unlock(&ide_tape_mutex);
1942
1943         return err;
1944 }
1945
1946 static const struct block_device_operations idetape_block_ops = {
1947         .owner          = THIS_MODULE,
1948         .open           = idetape_open,
1949         .release        = idetape_release,
1950         .ioctl          = idetape_ioctl,
1951 };
1952
1953 static int ide_tape_probe(ide_drive_t *drive)
1954 {
1955         idetape_tape_t *tape;
1956         struct gendisk *g;
1957         int minor;
1958
1959         ide_debug_log(IDE_DBG_FUNC, "enter");
1960
1961         if (!strstr(DRV_NAME, drive->driver_req))
1962                 goto failed;
1963
1964         if (drive->media != ide_tape)
1965                 goto failed;
1966
1967         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1968             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1969                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1970                                 " the driver\n", drive->name);
1971                 goto failed;
1972         }
1973         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1974         if (tape == NULL) {
1975                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1976                                 drive->name);
1977                 goto failed;
1978         }
1979
1980         g = alloc_disk(1 << PARTN_BITS);
1981         if (!g)
1982                 goto out_free_tape;
1983
1984         ide_init_disk(g, drive);
1985
1986         tape->dev.parent = &drive->gendev;
1987         tape->dev.release = ide_tape_release;
1988         dev_set_name(&tape->dev, "%s", dev_name(&drive->gendev));
1989
1990         if (device_register(&tape->dev))
1991                 goto out_free_disk;
1992
1993         tape->drive = drive;
1994         tape->driver = &idetape_driver;
1995         tape->disk = g;
1996
1997         g->private_data = &tape->driver;
1998
1999         drive->driver_data = tape;
2000
2001         mutex_lock(&idetape_ref_mutex);
2002         for (minor = 0; idetape_devs[minor]; minor++)
2003                 ;
2004         idetape_devs[minor] = tape;
2005         mutex_unlock(&idetape_ref_mutex);
2006
2007         idetape_setup(drive, tape, minor);
2008
2009         device_create(idetape_sysfs_class, &drive->gendev,
2010                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2011         device_create(idetape_sysfs_class, &drive->gendev,
2012                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2013                       "n%s", tape->name);
2014
2015         g->fops = &idetape_block_ops;
2016         ide_register_region(g);
2017
2018         return 0;
2019
2020 out_free_disk:
2021         put_disk(g);
2022 out_free_tape:
2023         kfree(tape);
2024 failed:
2025         return -ENODEV;
2026 }
2027
2028 static void __exit idetape_exit(void)
2029 {
2030         driver_unregister(&idetape_driver.gen_driver);
2031         class_destroy(idetape_sysfs_class);
2032         unregister_chrdev(IDETAPE_MAJOR, "ht");
2033 }
2034
2035 static int __init idetape_init(void)
2036 {
2037         int error = 1;
2038         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2039         if (IS_ERR(idetape_sysfs_class)) {
2040                 idetape_sysfs_class = NULL;
2041                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2042                 error = -EBUSY;
2043                 goto out;
2044         }
2045
2046         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2047                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2048                                 " interface\n");
2049                 error = -EBUSY;
2050                 goto out_free_class;
2051         }
2052
2053         error = driver_register(&idetape_driver.gen_driver);
2054         if (error)
2055                 goto out_free_driver;
2056
2057         return 0;
2058
2059 out_free_driver:
2060         driver_unregister(&idetape_driver.gen_driver);
2061 out_free_class:
2062         class_destroy(idetape_sysfs_class);
2063 out:
2064         return error;
2065 }
2066
2067 MODULE_ALIAS("ide:*m-tape*");
2068 module_init(idetape_init);
2069 module_exit(idetape_exit);
2070 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2071 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2072 MODULE_LICENSE("GPL");