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/slab.h>
  35 #include <linux/pci.h>
  36 #include <linux/ide.h>
  37 #include <linux/smp_lock.h>
  38 #include <linux/completion.h>
  39 #include <linux/bitops.h>
  40 #include <linux/mutex.h>
  41 #include <scsi/scsi.h>
  42
  43 #include <asm/byteorder.h>
  44 #include <linux/irq.h>
  45 #include <linux/uaccess.h>
  46 #include <linux/io.h>
  47 #include <asm/unaligned.h>
  48 #include <linux/mtio.h>
  49
  50 enum {
  51         /* output errors only */
  52         DBG_ERR =               (1 << 0),
  53         /* output all sense key/asc */
  54         DBG_SENSE =             (1 << 1),
  55         /* info regarding all chrdev-related procedures */
  56         DBG_CHRDEV =            (1 << 2),
  57         /* all remaining procedures */
  58         DBG_PROCS =             (1 << 3),
  59 };
  60
  61 /* define to see debug info */
  62 #define IDETAPE_DEBUG_LOG               0
  63
  64 #if IDETAPE_DEBUG_LOG
  65 #define debug_log(lvl, fmt, args...)                    \
  66 {                                                       \
  67         if (tape->debug_mask & lvl)                     \
  68         printk(KERN_INFO "ide-tape: " fmt, ## args);    \
  69 }
  70 #else
  71 #define debug_log(lvl, fmt, args...) do {} while (0)
  72 #endif
  73
  74 /**************************** Tunable parameters *****************************/
  75 /*
  76  * After each failed packet command we issue a request sense command and retry
  77  * the packet command IDETAPE_MAX_PC_RETRIES times.
  78  *
  79  * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
  80  */
  81 #define IDETAPE_MAX_PC_RETRIES          3
  82
  83 /*
  84  * The following parameter is used to select the point in the internal tape fifo
  85  * in which we will start to refill the buffer. Decreasing the following
  86  * parameter will improve the system's latency and interactive response, while
  87  * using a high value might improve system throughput.
  88  */
  89 #define IDETAPE_FIFO_THRESHOLD          2
  90
  91 /*
  92  * DSC polling parameters.
  93  *
  94  * Polling for DSC (a single bit in the status register) is a very important
  95  * function in ide-tape. There are two cases in which we poll for DSC:
  96  *
  97  * 1. Before a read/write packet command, to ensure that we can transfer data
  98  * from/to the tape's data buffers, without causing an actual media access.
  99  * In case the tape is not ready yet, we take out our request from the device
 100  * request queue, so that ide.c could service requests from the other device
 101  * on the same interface in the meantime.
 102  *
 103  * 2. After the successful initialization of a "media access packet command",
 104  * which is a command that can take a long time to complete (the interval can
 105  * range from several seconds to even an hour). Again, we postpone our request
 106  * in the middle to free the bus for the other device. The polling frequency
 107  * here should be lower than the read/write frequency since those media access
 108  * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
 109  * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
 110  * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
 111  *
 112  * We also set a timeout for the timer, in case something goes wrong. The
 113  * timeout should be longer then the maximum execution time of a tape operation.
 114  */
 115
 116 /* DSC timings. */
 117 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 118 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 119 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 120 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 121 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 122 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 123 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 124
 125 /*************************** End of tunable parameters ***********************/
 126
 127 /* tape directions */
 128 enum {
 129         IDETAPE_DIR_NONE  = (1 << 0),
 130         IDETAPE_DIR_READ  = (1 << 1),
 131         IDETAPE_DIR_WRITE = (1 << 2),
 132 };
 133
 134 /* Tape door status */
 135 #define DOOR_UNLOCKED                   0
 136 #define DOOR_LOCKED                     1
 137 #define DOOR_EXPLICITLY_LOCKED          2
 138
 139 /* Some defines for the SPACE command */
 140 #define IDETAPE_SPACE_OVER_FILEMARK     1
 141 #define IDETAPE_SPACE_TO_EOD            3
 142
 143 /* Some defines for the LOAD UNLOAD command */
 144 #define IDETAPE_LU_LOAD_MASK            1
 145 #define IDETAPE_LU_RETENSION_MASK       2
 146 #define IDETAPE_LU_EOT_MASK             4
 147
 148 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
 149 #define IDETAPE_BLOCK_DESCRIPTOR        0
 150 #define IDETAPE_CAPABILITIES_PAGE       0x2a
 151
 152 /*
 153  * Most of our global data which we need to save even as we leave the driver due
 154  * to an interrupt or a timer event is stored in the struct defined below.
 155  */
 156 typedef struct ide_tape_obj {
 157         ide_drive_t             *drive;
 158         struct ide_driver       *driver;
 159         struct gendisk          *disk;
 160         struct device           dev;
 161
 162         /* used by REQ_IDETAPE_{READ,WRITE} requests */
 163         struct ide_atapi_pc queued_pc;
 164
 165         /*
 166          * DSC polling variables.
 167          *
 168          * While polling for DSC we use postponed_rq to postpone the current
 169          * request so that ide.c will be able to service pending requests on the
 170          * other device. Note that at most we will have only one DSC (usually
 171          * data transfer) request in the device request queue.
 172          */
 173         struct request *postponed_rq;
 174         /* The time in which we started polling for DSC */
 175         unsigned long dsc_polling_start;
 176         /* Timer used to poll for dsc */
 177         struct timer_list dsc_timer;
 178         /* Read/Write dsc polling frequency */
 179         unsigned long best_dsc_rw_freq;
 180         unsigned long dsc_poll_freq;
 181         unsigned long dsc_timeout;
 182
 183         /* Read position information */
 184         u8 partition;
 185         /* Current block */
 186         unsigned int first_frame;
 187
 188         /* Last error information */
 189         u8 sense_key, asc, ascq;
 190
 191         /* Character device operation */
 192         unsigned int minor;
 193         /* device name */
 194         char name[4];
 195         /* Current character device data transfer direction */
 196         u8 chrdev_dir;
 197
 198         /* tape block size, usually 512 or 1024 bytes */
 199         unsigned short blk_size;
 200         int user_bs_factor;
 201
 202         /* Copy of the tape's Capabilities and Mechanical Page */
 203         u8 caps[20];
 204
 205         /*
 206          * Active data transfer request parameters.
 207          *
 208          * At most, there is only one ide-tape originated data transfer request
 209          * in the device request queue. This allows ide.c to easily service
 210          * requests from the other device when we postpone our active request.
 211          */
 212
 213         /* Data buffer size chosen based on the tape's recommendation */
 214         int buffer_size;
 215         /* Staging buffer of buffer_size bytes */
 216         void *buf;
 217         /* The read/write cursor */
 218         void *cur;
 219         /* The number of valid bytes in buf */
 220         size_t valid;
 221
 222         /* Measures average tape speed */
 223         unsigned long avg_time;
 224         int avg_size;
 225         int avg_speed;
 226
 227         /* the door is currently locked */
 228         int door_locked;
 229         /* the tape hardware is write protected */
 230         char drv_write_prot;
 231         /* the tape is write protected (hardware or opened as read-only) */
 232         char write_prot;
 233
 234         u32 debug_mask;
 235 } idetape_tape_t;
 236
 237 static DEFINE_MUTEX(idetape_ref_mutex);
 238
 239 static struct class *idetape_sysfs_class;
 240
 241 static void ide_tape_release(struct device *);
 242
 243 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
 244 {
 245         struct ide_tape_obj *tape = NULL;
 246
 247         mutex_lock(&idetape_ref_mutex);
 248         tape = ide_drv_g(disk, ide_tape_obj);
 249         if (tape) {
 250                 if (ide_device_get(tape->drive))
 251                         tape = NULL;
 252                 else
 253                         get_device(&tape->dev);
 254         }
 255         mutex_unlock(&idetape_ref_mutex);
 256         return tape;
 257 }
 258
 259 static void ide_tape_put(struct ide_tape_obj *tape)
 260 {
 261         ide_drive_t *drive = tape->drive;
 262
 263         mutex_lock(&idetape_ref_mutex);
 264         put_device(&tape->dev);
 265         ide_device_put(drive);
 266         mutex_unlock(&idetape_ref_mutex);
 267 }
 268
 269 /*
 270  * The variables below are used for the character device interface. Additional
 271  * state variables are defined in our ide_drive_t structure.
 272  */
 273 static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
 274
 275 static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
 276 {
 277         struct ide_tape_obj *tape = NULL;
 278
 279         mutex_lock(&idetape_ref_mutex);
 280         tape = idetape_devs[i];
 281         if (tape)
 282                 get_device(&tape->dev);
 283         mutex_unlock(&idetape_ref_mutex);
 284         return tape;
 285 }
 286
 287 /*
 288  * called on each failed packet command retry to analyze the request sense. We
 289  * currently do not utilize this information.
 290  */
 291 static void idetape_analyze_error(ide_drive_t *drive)
 292 {
 293         idetape_tape_t *tape = drive->driver_data;
 294         struct ide_atapi_pc *pc = drive->failed_pc;
 295         struct request *rq = drive->hwif->rq;
 296         u8 *sense = bio_data(rq->bio);
 297
 298         tape->sense_key = sense[2] & 0xF;
 299         tape->asc       = sense[12];
 300         tape->ascq      = sense[13];
 301
 302         debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
 303                  pc->c[0], tape->sense_key, tape->asc, tape->ascq);
 304
 305         /* correct remaining bytes to transfer */
 306         if (pc->flags & PC_FLAG_DMA_ERROR)
 307                 rq->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
 308
 309         /*
 310          * If error was the result of a zero-length read or write command,
 311          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
 312          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
 313          */
 314         if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
 315             /* length == 0 */
 316             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
 317                 if (tape->sense_key == 5) {
 318                         /* don't report an error, everything's ok */
 319                         pc->error = 0;
 320                         /* don't retry read/write */
 321                         pc->flags |= PC_FLAG_ABORT;
 322                 }
 323         }
 324         if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
 325                 pc->error = IDE_DRV_ERROR_FILEMARK;
 326                 pc->flags |= PC_FLAG_ABORT;
 327         }
 328         if (pc->c[0] == WRITE_6) {
 329                 if ((sense[2] & 0x40) || (tape->sense_key == 0xd
 330                      && tape->asc == 0x0 && tape->ascq == 0x2)) {
 331                         pc->error = IDE_DRV_ERROR_EOD;
 332                         pc->flags |= PC_FLAG_ABORT;
 333                 }
 334         }
 335         if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 336                 if (tape->sense_key == 8) {
 337                         pc->error = IDE_DRV_ERROR_EOD;
 338                         pc->flags |= PC_FLAG_ABORT;
 339                 }
 340                 if (!(pc->flags & PC_FLAG_ABORT) &&
 341                     (blk_rq_bytes(rq) - rq->resid_len))
 342                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
 343         }
 344 }
 345
 346 static void ide_tape_handle_dsc(ide_drive_t *);
 347
 348 static int ide_tape_callback(ide_drive_t *drive, int dsc)
 349 {
 350         idetape_tape_t *tape = drive->driver_data;
 351         struct ide_atapi_pc *pc = drive->pc;
 352         struct request *rq = drive->hwif->rq;
 353         int uptodate = pc->error ? 0 : 1;
 354         int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 355
 356         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 357
 358         if (dsc)
 359                 ide_tape_handle_dsc(drive);
 360
 361         if (drive->failed_pc == pc)
 362                 drive->failed_pc = NULL;
 363
 364         if (pc->c[0] == REQUEST_SENSE) {
 365                 if (uptodate)
 366                         idetape_analyze_error(drive);
 367                 else
 368                         printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
 369                                         "itself - Aborting request!\n");
 370         } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 371                 unsigned int blocks =
 372                         (blk_rq_bytes(rq) - rq->resid_len) / tape->blk_size;
 373
 374                 tape->avg_size += blocks * tape->blk_size;
 375
 376                 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
 377                         tape->avg_speed = tape->avg_size * HZ /
 378                                 (jiffies - tape->avg_time) / 1024;
 379                         tape->avg_size = 0;
 380                         tape->avg_time = jiffies;
 381                 }
 382
 383                 tape->first_frame += blocks;
 384
 385                 if (pc->error) {
 386                         uptodate = 0;
 387                         err = pc->error;
 388                 }
 389         }
 390         rq->errors = err;
 391
 392         return uptodate;
 393 }
 394
 395 /*
 396  * Postpone the current request so that ide.c will be able to service requests
 397  * from another device on the same port while we are polling for DSC.
 398  */
 399 static void idetape_postpone_request(ide_drive_t *drive)
 400 {
 401         idetape_tape_t *tape = drive->driver_data;
 402
 403         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 404
 405         tape->postponed_rq = drive->hwif->rq;
 406
 407         ide_stall_queue(drive, tape->dsc_poll_freq);
 408 }
 409
 410 static void ide_tape_handle_dsc(ide_drive_t *drive)
 411 {
 412         idetape_tape_t *tape = drive->driver_data;
 413
 414         /* Media access command */
 415         tape->dsc_polling_start = jiffies;
 416         tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
 417         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
 418         /* Allow ide.c to handle other requests */
 419         idetape_postpone_request(drive);
 420 }
 421
 422 /*
 423  * Packet Command Interface
 424  *
 425  * The current Packet Command is available in drive->pc, and will not change
 426  * until we finish handling it. Each packet command is associated with a
 427  * callback function that will be called when the command is finished.
 428  *
 429  * The handling will be done in three stages:
 430  *
 431  * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
 432  * the interrupt handler to ide_pc_intr.
 433  *
 434  * 2. On each interrupt, ide_pc_intr will be called. This step will be
 435  * repeated until the device signals us that no more interrupts will be issued.
 436  *
 437  * 3. ATAPI Tape media access commands have immediate status with a delayed
 438  * process. In case of a successful initiation of a media access packet command,
 439  * the DSC bit will be set when the actual execution of the command is finished.
 440  * Since the tape drive will not issue an interrupt, we have to poll for this
 441  * event. In this case, we define the request as "low priority request" by
 442  * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 443  * exit the driver.
 444  *
 445  * ide.c will then give higher priority to requests which originate from the
 446  * other device, until will change rq_status to RQ_ACTIVE.
 447  *
 448  * 4. When the packet command is finished, it will be checked for errors.
 449  *
 450  * 5. In case an error was found, we queue a request sense packet command in
 451  * front of the request queue and retry the operation up to
 452  * IDETAPE_MAX_PC_RETRIES times.
 453  *
 454  * 6. In case no error was found, or we decided to give up and not to retry
 455  * again, the callback function will be called and then we will handle the next
 456  * request.
 457  */
 458
 459 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 460                                          struct ide_cmd *cmd,
 461                                          struct ide_atapi_pc *pc)
 462 {
 463         idetape_tape_t *tape = drive->driver_data;
 464         struct request *rq = drive->hwif->rq;
 465
 466         if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
 467                 drive->failed_pc = pc;
 468
 469         /* Set the current packet command */
 470         drive->pc = pc;
 471
 472         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
 473                 (pc->flags & PC_FLAG_ABORT)) {
 474
 475                 /*
 476                  * We will "abort" retrying a packet command in case legitimate
 477                  * error code was received (crossing a filemark, or end of the
 478                  * media, for example).
 479                  */
 480                 if (!(pc->flags & PC_FLAG_ABORT)) {
 481                         if (!(pc->c[0] == TEST_UNIT_READY &&
 482                               tape->sense_key == 2 && tape->asc == 4 &&
 483                              (tape->ascq == 1 || tape->ascq == 8))) {
 484                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
 485                                                 "pc = %2x, key = %2x, "
 486                                                 "asc = %2x, ascq = %2x\n",
 487                                                 tape->name, pc->c[0],
 488                                                 tape->sense_key, tape->asc,
 489                                                 tape->ascq);
 490                         }
 491                         /* Giving up */
 492                         pc->error = IDE_DRV_ERROR_GENERAL;
 493                 }
 494
 495                 drive->failed_pc = NULL;
 496                 drive->pc_callback(drive, 0);
 497                 ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
 498                 return ide_stopped;
 499         }
 500         debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
 501
 502         pc->retries++;
 503
 504         return ide_issue_pc(drive, cmd);
 505 }
 506
 507 /* A mode sense command is used to "sense" tape parameters. */
 508 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 509 {
 510         ide_init_pc(pc);
 511         pc->c[0] = MODE_SENSE;
 512         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
 513                 /* DBD = 1 - Don't return block descriptors */
 514                 pc->c[1] = 8;
 515         pc->c[2] = page_code;
 516         /*
 517          * Changed pc->c[3] to 0 (255 will at best return unused info).
 518          *
 519          * For SCSI this byte is defined as subpage instead of high byte
 520          * of length and some IDE drives seem to interpret it this way
 521          * and return an error when 255 is used.
 522          */
 523         pc->c[3] = 0;
 524         /* We will just discard data in that case */
 525         pc->c[4] = 255;
 526         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
 527                 pc->req_xfer = 12;
 528         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
 529                 pc->req_xfer = 24;
 530         else
 531                 pc->req_xfer = 50;
 532 }
 533
 534 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 535 {
 536         ide_hwif_t *hwif = drive->hwif;
 537         idetape_tape_t *tape = drive->driver_data;
 538         struct ide_atapi_pc *pc = drive->pc;
 539         u8 stat;
 540
 541         stat = hwif->tp_ops->read_status(hwif);
 542
 543         if (stat & ATA_DSC) {
 544                 if (stat & ATA_ERR) {
 545                         /* Error detected */
 546                         if (pc->c[0] != TEST_UNIT_READY)
 547                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
 548                                                 tape->name);
 549                         /* Retry operation */
 550                         ide_retry_pc(drive);
 551                         return ide_stopped;
 552                 }
 553                 pc->error = 0;
 554         } else {
 555                 pc->error = IDE_DRV_ERROR_GENERAL;
 556                 drive->failed_pc = NULL;
 557         }
 558         drive->pc_callback(drive, 0);
 559         return ide_stopped;
 560 }
 561
 562 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
 563                                    struct ide_atapi_pc *pc, struct request *rq,
 564                                    u8 opcode)
 565 {
 566         unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
 567
 568         ide_init_pc(pc);
 569         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
 570         pc->c[1] = 1;
 571
 572         if (blk_rq_bytes(rq) == tape->buffer_size)
 573                 pc->flags |= PC_FLAG_DMA_OK;
 574
 575         if (opcode == READ_6)
 576                 pc->c[0] = READ_6;
 577         else if (opcode == WRITE_6) {
 578                 pc->c[0] = WRITE_6;
 579                 pc->flags |= PC_FLAG_WRITING;
 580         }
 581
 582         memcpy(rq->cmd, pc->c, 12);
 583 }
 584
 585 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 586                                           struct request *rq, sector_t block)
 587 {
 588         ide_hwif_t *hwif = drive->hwif;
 589         idetape_tape_t *tape = drive->driver_data;
 590         struct ide_atapi_pc *pc = NULL;
 591         struct request *postponed_rq = tape->postponed_rq;
 592         struct ide_cmd cmd;
 593         u8 stat;
 594
 595         debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %u\n"
 596                   (unsigned long long)blk_rq_pos(rq), blk_rq_sectors(rq));
 597
 598         if (!(blk_special_request(rq) || blk_sense_request(rq))) {
 599                 /* We do not support buffer cache originated requests. */
 600                 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
 601                         "request queue (%d)\n", drive->name, rq->cmd_type);
 602                 if (blk_fs_request(rq) == 0 && rq->errors == 0)
 603                         rq->errors = -EIO;
 604                 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
 605                 return ide_stopped;
 606         }
 607
 608         /* Retry a failed packet command */
 609         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 610                 pc = drive->failed_pc;
 611                 goto out;
 612         }
 613
 614         if (postponed_rq != NULL)
 615                 if (rq != postponed_rq) {
 616                         printk(KERN_ERR "ide-tape: ide-tape.c bug - "
 617                                         "Two DSC requests were queued\n");
 618                         drive->failed_pc = NULL;
 619                         rq->errors = 0;
 620                         ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 621                         return ide_stopped;
 622                 }
 623
 624         tape->postponed_rq = NULL;
 625
 626         /*
 627          * If the tape is still busy, postpone our request and service
 628          * the other device meanwhile.
 629          */
 630         stat = hwif->tp_ops->read_status(hwif);
 631
 632         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 633             (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
 634                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 635
 636         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 637                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 638                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 639         }
 640
 641         if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) &&
 642             (stat & ATA_DSC) == 0) {
 643                 if (postponed_rq == NULL) {
 644                         tape->dsc_polling_start = jiffies;
 645                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 646                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 647                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 648                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 649                                 tape->name);
 650                         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 651                                 idetape_media_access_finished(drive);
 652                                 return ide_stopped;
 653                         } else {
 654                                 return ide_do_reset(drive);
 655                         }
 656                 } else if (time_after(jiffies,
 657                                         tape->dsc_polling_start +
 658                                         IDETAPE_DSC_MA_THRESHOLD))
 659                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 660                 idetape_postpone_request(drive);
 661                 return ide_stopped;
 662         }
 663         if (rq->cmd[13] & REQ_IDETAPE_READ) {
 664                 pc = &tape->queued_pc;
 665                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 666                 goto out;
 667         }
 668         if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
 669                 pc = &tape->queued_pc;
 670                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 671                 goto out;
 672         }
 673         if (rq->cmd[13] & REQ_IDETAPE_PC1) {
 674                 pc = (struct ide_atapi_pc *)rq->special;
 675                 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
 676                 rq->cmd[13] |= REQ_IDETAPE_PC2;
 677                 goto out;
 678         }
 679         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 680                 idetape_media_access_finished(drive);
 681                 return ide_stopped;
 682         }
 683         BUG();
 684
 685 out:
 686         /* prepare sense request for this command */
 687         ide_prep_sense(drive, rq);
 688
 689         memset(&cmd, 0, sizeof(cmd));
 690
 691         if (rq_data_dir(rq))
 692                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 693
 694         cmd.rq = rq;
 695
 696         ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
 697         ide_map_sg(drive, &cmd);
 698
 699         return ide_tape_issue_pc(drive, &cmd, pc);
 700 }
 701
 702 /*
 703  * Write a filemark if write_filemark=1. Flush the device buffers without
 704  * writing a filemark otherwise.
 705  */
 706 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 707                 struct ide_atapi_pc *pc, int write_filemark)
 708 {
 709         ide_init_pc(pc);
 710         pc->c[0] = WRITE_FILEMARKS;
 711         pc->c[4] = write_filemark;
 712         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 713 }
 714
 715 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 716 {
 717         idetape_tape_t *tape = drive->driver_data;
 718         struct gendisk *disk = tape->disk;
 719         int load_attempted = 0;
 720
 721         /* Wait for the tape to become ready */
 722         set_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
 723         timeout += jiffies;
 724         while (time_before(jiffies, timeout)) {
 725                 if (ide_do_test_unit_ready(drive, disk) == 0)
 726                         return 0;
 727                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 728                     || (tape->asc == 0x3A)) {
 729                         /* no media */
 730                         if (load_attempted)
 731                                 return -ENOMEDIUM;
 732                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 733                         load_attempted = 1;
 734                 /* not about to be ready */
 735                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 736                              (tape->ascq == 1 || tape->ascq == 8)))
 737                         return -EIO;
 738                 msleep(100);
 739         }
 740         return -EIO;
 741 }
 742
 743 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 744 {
 745         struct ide_tape_obj *tape = drive->driver_data;
 746         struct ide_atapi_pc pc;
 747         int rc;
 748
 749         idetape_create_write_filemark_cmd(drive, &pc, 0);
 750         rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
 751         if (rc)
 752                 return rc;
 753         idetape_wait_ready(drive, 60 * 5 * HZ);
 754         return 0;
 755 }
 756
 757 static int ide_tape_read_position(ide_drive_t *drive)
 758 {
 759         idetape_tape_t *tape = drive->driver_data;
 760         struct ide_atapi_pc pc;
 761         u8 buf[20];
 762
 763         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 764
 765         /* prep cmd */
 766         ide_init_pc(&pc);
 767         pc.c[0] = READ_POSITION;
 768         pc.req_xfer = 20;
 769
 770         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
 771                 return -1;
 772
 773         if (!pc.error) {
 774                 debug_log(DBG_SENSE, "BOP - %s\n",
 775                                 (buf[0] & 0x80) ? "Yes" : "No");
 776                 debug_log(DBG_SENSE, "EOP - %s\n",
 777                                 (buf[0] & 0x40) ? "Yes" : "No");
 778
 779                 if (buf[0] & 0x4) {
 780                         printk(KERN_INFO "ide-tape: Block location is unknown"
 781                                          "to the tape\n");
 782                         clear_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
 783                         return -1;
 784                 } else {
 785                         debug_log(DBG_SENSE, "Block Location - %u\n",
 786                                         be32_to_cpup((__be32 *)&buf[4]));
 787
 788                         tape->partition = buf[1];
 789                         tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
 790                         set_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
 791                 }
 792         }
 793
 794         return tape->first_frame;
 795 }
 796
 797 static void idetape_create_locate_cmd(ide_drive_t *drive,
 798                 struct ide_atapi_pc *pc,
 799                 unsigned int block, u8 partition, int skip)
 800 {
 801         ide_init_pc(pc);
 802         pc->c[0] = POSITION_TO_ELEMENT;
 803         pc->c[1] = 2;
 804         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 805         pc->c[8] = partition;
 806         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 807 }
 808
 809 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 810 {
 811         idetape_tape_t *tape = drive->driver_data;
 812
 813         if (tape->chrdev_dir != IDETAPE_DIR_READ)
 814                 return;
 815
 816         clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags);
 817         tape->valid = 0;
 818         if (tape->buf != NULL) {
 819                 kfree(tape->buf);
 820                 tape->buf = NULL;
 821         }
 822
 823         tape->chrdev_dir = IDETAPE_DIR_NONE;
 824 }
 825
 826 /*
 827  * Position the tape to the requested block using the LOCATE packet command.
 828  * A READ POSITION command is then issued to check where we are positioned. Like
 829  * all higher level operations, we queue the commands at the tail of the request
 830  * queue and wait for their completion.
 831  */
 832 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 833                 u8 partition, int skip)
 834 {
 835         idetape_tape_t *tape = drive->driver_data;
 836         struct gendisk *disk = tape->disk;
 837         int ret;
 838         struct ide_atapi_pc pc;
 839
 840         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 841                 __ide_tape_discard_merge_buffer(drive);
 842         idetape_wait_ready(drive, 60 * 5 * HZ);
 843         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 844         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 845         if (ret)
 846                 return ret;
 847
 848         ret = ide_tape_read_position(drive);
 849         if (ret < 0)
 850                 return ret;
 851         return 0;
 852 }
 853
 854 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 855                                           int restore_position)
 856 {
 857         idetape_tape_t *tape = drive->driver_data;
 858         int seek, position;
 859
 860         __ide_tape_discard_merge_buffer(drive);
 861         if (restore_position) {
 862                 position = ide_tape_read_position(drive);
 863                 seek = position > 0 ? position : 0;
 864                 if (idetape_position_tape(drive, seek, 0, 0)) {
 865                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 866                                          " %s\n", tape->name, __func__);
 867                         return;
 868                 }
 869         }
 870 }
 871
 872 /*
 873  * Generate a read/write request for the block device interface and wait for it
 874  * to be serviced.
 875  */
 876 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 877 {
 878         idetape_tape_t *tape = drive->driver_data;
 879         struct request *rq;
 880         int ret;
 881
 882         debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
 883         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 884         BUG_ON(size < 0 || size % tape->blk_size);
 885
 886         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
 887         rq->cmd_type = REQ_TYPE_SPECIAL;
 888         rq->cmd[13] = cmd;
 889         rq->rq_disk = tape->disk;
 890
 891         if (size) {
 892                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 893                                       __GFP_WAIT);
 894                 if (ret)
 895                         goto out_put;
 896         }
 897
 898         blk_execute_rq(drive->queue, tape->disk, rq, 0);
 899
 900         /* calculate the number of transferred bytes and update buffer state */
 901         size -= rq->resid_len;
 902         tape->cur = tape->buf;
 903         if (cmd == REQ_IDETAPE_READ)
 904                 tape->valid = size;
 905         else
 906                 tape->valid = 0;
 907
 908         ret = size;
 909         if (rq->errors == IDE_DRV_ERROR_GENERAL)
 910                 ret = -EIO;
 911 out_put:
 912         blk_put_request(rq);
 913         return ret;
 914 }
 915
 916 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 917 {
 918         ide_init_pc(pc);
 919         pc->c[0] = INQUIRY;
 920         pc->c[4] = 254;
 921         pc->req_xfer = 254;
 922 }
 923
 924 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 925                 struct ide_atapi_pc *pc)
 926 {
 927         ide_init_pc(pc);
 928         pc->c[0] = REZERO_UNIT;
 929         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 930 }
 931
 932 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 933 {
 934         ide_init_pc(pc);
 935         pc->c[0] = ERASE;
 936         pc->c[1] = 1;
 937         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 938 }
 939
 940 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 941 {
 942         ide_init_pc(pc);
 943         pc->c[0] = SPACE;
 944         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 945         pc->c[1] = cmd;
 946         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 947 }
 948
 949 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 950 {
 951         idetape_tape_t *tape = drive->driver_data;
 952
 953         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 954                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 955                                 " but we are not writing.\n");
 956                 return;
 957         }
 958         if (tape->buf) {
 959                 size_t aligned = roundup(tape->valid, tape->blk_size);
 960
 961                 memset(tape->cur, 0, aligned - tape->valid);
 962                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 963                 kfree(tape->buf);
 964                 tape->buf = NULL;
 965         }
 966         tape->chrdev_dir = IDETAPE_DIR_NONE;
 967 }
 968
 969 static int idetape_init_rw(ide_drive_t *drive, int dir)
 970 {
 971         idetape_tape_t *tape = drive->driver_data;
 972         int rc;
 973
 974         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 975
 976         if (tape->chrdev_dir == dir)
 977                 return 0;
 978
 979         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 980                 ide_tape_discard_merge_buffer(drive, 1);
 981         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 982                 ide_tape_flush_merge_buffer(drive);
 983                 idetape_flush_tape_buffers(drive);
 984         }
 985
 986         if (tape->buf || tape->valid) {
 987                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 988                 tape->valid = 0;
 989         }
 990
 991         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 992         if (!tape->buf)
 993                 return -ENOMEM;
 994         tape->chrdev_dir = dir;
 995         tape->cur = tape->buf;
 996
 997         /*
 998          * Issue a 0 rw command to ensure that DSC handshake is
 999          * switched from completion mode to buffer available mode.  No
1000          * point in issuing this if DSC overlap isn't supported, some
1001          * drives (Seagate STT3401A) will return an error.
1002          */
1003         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1004                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
1005                                                   : REQ_IDETAPE_WRITE;
1006
1007                 rc = idetape_queue_rw_tail(drive, cmd, 0);
1008                 if (rc < 0) {
1009                         kfree(tape->buf);
1010                         tape->buf = NULL;
1011                         tape->chrdev_dir = IDETAPE_DIR_NONE;
1012                         return rc;
1013                 }
1014         }
1015
1016         return 0;
1017 }
1018
1019 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
1020 {
1021         idetape_tape_t *tape = drive->driver_data;
1022
1023         memset(tape->buf, 0, tape->buffer_size);
1024
1025         while (bcount) {
1026                 unsigned int count = min(tape->buffer_size, bcount);
1027
1028                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1029                 bcount -= count;
1030         }
1031 }
1032
1033 /*
1034  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1035  * currently support only one partition.
1036  */
1037 static int idetape_rewind_tape(ide_drive_t *drive)
1038 {
1039         struct ide_tape_obj *tape = drive->driver_data;
1040         struct gendisk *disk = tape->disk;
1041         struct ide_atapi_pc pc;
1042         int ret;
1043
1044         debug_log(DBG_SENSE, "Enter %s\n", __func__);
1045
1046         idetape_create_rewind_cmd(drive, &pc);
1047         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1048         if (ret)
1049                 return ret;
1050
1051         ret = ide_tape_read_position(drive);
1052         if (ret < 0)
1053                 return ret;
1054         return 0;
1055 }
1056
1057 /* mtio.h compatible commands should be issued to the chrdev interface. */
1058 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1059                                 unsigned long arg)
1060 {
1061         idetape_tape_t *tape = drive->driver_data;
1062         void __user *argp = (void __user *)arg;
1063
1064         struct idetape_config {
1065                 int dsc_rw_frequency;
1066                 int dsc_media_access_frequency;
1067                 int nr_stages;
1068         } config;
1069
1070         debug_log(DBG_PROCS, "Enter %s\n", __func__);
1071
1072         switch (cmd) {
1073         case 0x0340:
1074                 if (copy_from_user(&config, argp, sizeof(config)))
1075                         return -EFAULT;
1076                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1077                 break;
1078         case 0x0350:
1079                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1080                 config.nr_stages = 1;
1081                 if (copy_to_user(argp, &config, sizeof(config)))
1082                         return -EFAULT;
1083                 break;
1084         default:
1085                 return -EIO;
1086         }
1087         return 0;
1088 }
1089
1090 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1091                                         int mt_count)
1092 {
1093         idetape_tape_t *tape = drive->driver_data;
1094         struct gendisk *disk = tape->disk;
1095         struct ide_atapi_pc pc;
1096         int retval, count = 0;
1097         int sprev = !!(tape->caps[4] & 0x20);
1098
1099         if (mt_count == 0)
1100                 return 0;
1101         if (MTBSF == mt_op || MTBSFM == mt_op) {
1102                 if (!sprev)
1103                         return -EIO;
1104                 mt_count = -mt_count;
1105         }
1106
1107         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1108                 tape->valid = 0;
1109                 if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1110                         ++count;
1111                 ide_tape_discard_merge_buffer(drive, 0);
1112         }
1113
1114         switch (mt_op) {
1115         case MTFSF:
1116         case MTBSF:
1117                 idetape_create_space_cmd(&pc, mt_count - count,
1118                                          IDETAPE_SPACE_OVER_FILEMARK);
1119                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1120         case MTFSFM:
1121         case MTBSFM:
1122                 if (!sprev)
1123                         return -EIO;
1124                 retval = idetape_space_over_filemarks(drive, MTFSF,
1125                                                       mt_count - count);
1126                 if (retval)
1127                         return retval;
1128                 count = (MTBSFM == mt_op ? 1 : -1);
1129                 return idetape_space_over_filemarks(drive, MTFSF, count);
1130         default:
1131                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1132                                 mt_op);
1133                 return -EIO;
1134         }
1135 }
1136
1137 /*
1138  * Our character device read / write functions.
1139  *
1140  * The tape is optimized to maximize throughput when it is transferring an
1141  * integral number of the "continuous transfer limit", which is a parameter of
1142  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1143  *
1144  * As of version 1.3 of the driver, the character device provides an abstract
1145  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1146  * same backup/restore procedure is supported. The driver will internally
1147  * convert the requests to the recommended transfer unit, so that an unmatch
1148  * between the user's block size to the recommended size will only result in a
1149  * (slightly) increased driver overhead, but will no longer hit performance.
1150  * This is not applicable to Onstream.
1151  */
1152 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1153                                    size_t count, loff_t *ppos)
1154 {
1155         struct ide_tape_obj *tape = file->private_data;
1156         ide_drive_t *drive = tape->drive;
1157         size_t done = 0;
1158         ssize_t ret = 0;
1159         int rc;
1160
1161         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1162
1163         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1164                 if (test_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags))
1165                         if (count > tape->blk_size &&
1166                             (count % tape->blk_size) == 0)
1167                                 tape->user_bs_factor = count / tape->blk_size;
1168         }
1169
1170         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1171         if (rc < 0)
1172                 return rc;
1173
1174         while (done < count) {
1175                 size_t todo;
1176
1177                 /* refill if staging buffer is empty */
1178                 if (!tape->valid) {
1179                         /* If we are at a filemark, nothing more to read */
1180                         if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1181                                 break;
1182                         /* read */
1183                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1184                                                   tape->buffer_size) <= 0)
1185                                 break;
1186                 }
1187
1188                 /* copy out */
1189                 todo = min_t(size_t, count - done, tape->valid);
1190                 if (copy_to_user(buf + done, tape->cur, todo))
1191                         ret = -EFAULT;
1192
1193                 tape->cur += todo;
1194                 tape->valid -= todo;
1195                 done += todo;
1196         }
1197
1198         if (!done && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) {
1199                 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
1200
1201                 idetape_space_over_filemarks(drive, MTFSF, 1);
1202                 return 0;
1203         }
1204
1205         return ret ? ret : done;
1206 }
1207
1208 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1209                                      size_t count, loff_t *ppos)
1210 {
1211         struct ide_tape_obj *tape = file->private_data;
1212         ide_drive_t *drive = tape->drive;
1213         size_t done = 0;
1214         ssize_t ret = 0;
1215         int rc;
1216
1217         /* The drive is write protected. */
1218         if (tape->write_prot)
1219                 return -EACCES;
1220
1221         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1222
1223         /* Initialize write operation */
1224         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1225         if (rc < 0)
1226                 return rc;
1227
1228         while (done < count) {
1229                 size_t todo;
1230
1231                 /* flush if staging buffer is full */
1232                 if (tape->valid == tape->buffer_size &&
1233                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1234                                           tape->buffer_size) <= 0)
1235                         return rc;
1236
1237                 /* copy in */
1238                 todo = min_t(size_t, count - done,
1239                              tape->buffer_size - tape->valid);
1240                 if (copy_from_user(tape->cur, buf + done, todo))
1241                         ret = -EFAULT;
1242
1243                 tape->cur += todo;
1244                 tape->valid += todo;
1245                 done += todo;
1246         }
1247
1248         return ret ? ret : done;
1249 }
1250
1251 static int idetape_write_filemark(ide_drive_t *drive)
1252 {
1253         struct ide_tape_obj *tape = drive->driver_data;
1254         struct ide_atapi_pc pc;
1255
1256         /* Write a filemark */
1257         idetape_create_write_filemark_cmd(drive, &pc, 1);
1258         if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1259                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1260                 return -EIO;
1261         }
1262         return 0;
1263 }
1264
1265 /*
1266  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1267  * requested.
1268  *
1269  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1270  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1271  * usually not supported.
1272  *
1273  * The following commands are currently not supported:
1274  *
1275  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1276  * MT_ST_WRITE_THRESHOLD.
1277  */
1278 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1279 {
1280         idetape_tape_t *tape = drive->driver_data;
1281         struct gendisk *disk = tape->disk;
1282         struct ide_atapi_pc pc;
1283         int i, retval;
1284
1285         debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
1286                         mt_op, mt_count);
1287
1288         switch (mt_op) {
1289         case MTFSF:
1290         case MTFSFM:
1291         case MTBSF:
1292         case MTBSFM:
1293                 if (!mt_count)
1294                         return 0;
1295                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1296         default:
1297                 break;
1298         }
1299
1300         switch (mt_op) {
1301         case MTWEOF:
1302                 if (tape->write_prot)
1303                         return -EACCES;
1304                 ide_tape_discard_merge_buffer(drive, 1);
1305                 for (i = 0; i < mt_count; i++) {
1306                         retval = idetape_write_filemark(drive);
1307                         if (retval)
1308                                 return retval;
1309                 }
1310                 return 0;
1311         case MTREW:
1312                 ide_tape_discard_merge_buffer(drive, 0);
1313                 if (idetape_rewind_tape(drive))
1314                         return -EIO;
1315                 return 0;
1316         case MTLOAD:
1317                 ide_tape_discard_merge_buffer(drive, 0);
1318                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1319         case MTUNLOAD:
1320         case MTOFFL:
1321                 /*
1322                  * If door is locked, attempt to unlock before
1323                  * attempting to eject.
1324                  */
1325                 if (tape->door_locked) {
1326                         if (!ide_set_media_lock(drive, disk, 0))
1327                                 tape->door_locked = DOOR_UNLOCKED;
1328                 }
1329                 ide_tape_discard_merge_buffer(drive, 0);
1330                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1331                 if (!retval)
1332                         clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1333                 return retval;
1334         case MTNOP:
1335                 ide_tape_discard_merge_buffer(drive, 0);
1336                 return idetape_flush_tape_buffers(drive);
1337         case MTRETEN:
1338                 ide_tape_discard_merge_buffer(drive, 0);
1339                 return ide_do_start_stop(drive, disk,
1340                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1341         case MTEOM:
1342                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1343                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1344         case MTERASE:
1345                 (void)idetape_rewind_tape(drive);
1346                 idetape_create_erase_cmd(&pc);
1347                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1348         case MTSETBLK:
1349                 if (mt_count) {
1350                         if (mt_count < tape->blk_size ||
1351                             mt_count % tape->blk_size)
1352                                 return -EIO;
1353                         tape->user_bs_factor = mt_count / tape->blk_size;
1354                         clear_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1355                 } else
1356                         set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1357                 return 0;
1358         case MTSEEK:
1359                 ide_tape_discard_merge_buffer(drive, 0);
1360                 return idetape_position_tape(drive,
1361                         mt_count * tape->user_bs_factor, tape->partition, 0);
1362         case MTSETPART:
1363                 ide_tape_discard_merge_buffer(drive, 0);
1364                 return idetape_position_tape(drive, 0, mt_count, 0);
1365         case MTFSR:
1366         case MTBSR:
1367         case MTLOCK:
1368                 retval = ide_set_media_lock(drive, disk, 1);
1369                 if (retval)
1370                         return retval;
1371                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1372                 return 0;
1373         case MTUNLOCK:
1374                 retval = ide_set_media_lock(drive, disk, 0);
1375                 if (retval)
1376                         return retval;
1377                 tape->door_locked = DOOR_UNLOCKED;
1378                 return 0;
1379         default:
1380                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1381                                 mt_op);
1382                 return -EIO;
1383         }
1384 }
1385
1386 /*
1387  * Our character device ioctls. General mtio.h magnetic io commands are
1388  * supported here, and not in the corresponding block interface. Our own
1389  * ide-tape ioctls are supported on both interfaces.
1390  */
1391 static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
1392                                 unsigned int cmd, unsigned long arg)
1393 {
1394         struct ide_tape_obj *tape = file->private_data;
1395         ide_drive_t *drive = tape->drive;
1396         struct mtop mtop;
1397         struct mtget mtget;
1398         struct mtpos mtpos;
1399         int block_offset = 0, position = tape->first_frame;
1400         void __user *argp = (void __user *)arg;
1401
1402         debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
1403
1404         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1405                 ide_tape_flush_merge_buffer(drive);
1406                 idetape_flush_tape_buffers(drive);
1407         }
1408         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1409                 block_offset = tape->valid /
1410                         (tape->blk_size * tape->user_bs_factor);
1411                 position = ide_tape_read_position(drive);
1412                 if (position < 0)
1413                         return -EIO;
1414         }
1415         switch (cmd) {
1416         case MTIOCTOP:
1417                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1418                         return -EFAULT;
1419                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1420         case MTIOCGET:
1421                 memset(&mtget, 0, sizeof(struct mtget));
1422                 mtget.mt_type = MT_ISSCSI2;
1423                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1424                 mtget.mt_dsreg =
1425                         ((tape->blk_size * tape->user_bs_factor)
1426                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1427
1428                 if (tape->drv_write_prot)
1429                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1430
1431                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1432                         return -EFAULT;
1433                 return 0;
1434         case MTIOCPOS:
1435                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1436                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1437                         return -EFAULT;
1438                 return 0;
1439         default:
1440                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1441                         ide_tape_discard_merge_buffer(drive, 1);
1442                 return idetape_blkdev_ioctl(drive, cmd, arg);
1443         }
1444 }
1445
1446 /*
1447  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1448  * block size with the reported value.
1449  */
1450 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1451 {
1452         idetape_tape_t *tape = drive->driver_data;
1453         struct ide_atapi_pc pc;
1454         u8 buf[12];
1455
1456         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1457         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1458                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1459                 if (tape->blk_size == 0) {
1460                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1461                                             "block size, assuming 32k\n");
1462                         tape->blk_size = 32768;
1463                 }
1464                 return;
1465         }
1466         tape->blk_size = (buf[4 + 5] << 16) +
1467                                 (buf[4 + 6] << 8)  +
1468                                  buf[4 + 7];
1469         tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1470 }
1471
1472 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1473 {
1474         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1475         ide_drive_t *drive;
1476         idetape_tape_t *tape;
1477         int retval;
1478
1479         if (i >= MAX_HWIFS * MAX_DRIVES)
1480                 return -ENXIO;
1481
1482         lock_kernel();
1483         tape = ide_tape_chrdev_get(i);
1484         if (!tape) {
1485                 unlock_kernel();
1486                 return -ENXIO;
1487         }
1488
1489         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1490
1491         /*
1492          * We really want to do nonseekable_open(inode, filp); here, but some
1493          * versions of tar incorrectly call lseek on tapes and bail out if that
1494          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1495          */
1496         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1497
1498         drive = tape->drive;
1499
1500         filp->private_data = tape;
1501
1502         if (test_and_set_bit(IDE_AFLAG_BUSY, &drive->atapi_flags)) {
1503                 retval = -EBUSY;
1504                 goto out_put_tape;
1505         }
1506
1507         retval = idetape_wait_ready(drive, 60 * HZ);
1508         if (retval) {
1509                 clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1510                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1511                 goto out_put_tape;
1512         }
1513
1514         ide_tape_read_position(drive);
1515         if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags))
1516                 (void)idetape_rewind_tape(drive);
1517
1518         /* Read block size and write protect status from drive. */
1519         ide_tape_get_bsize_from_bdesc(drive);
1520
1521         /* Set write protect flag if device is opened as read-only. */
1522         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1523                 tape->write_prot = 1;
1524         else
1525                 tape->write_prot = tape->drv_write_prot;
1526
1527         /* Make sure drive isn't write protected if user wants to write. */
1528         if (tape->write_prot) {
1529                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1530                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1531                         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1532                         retval = -EROFS;
1533                         goto out_put_tape;
1534                 }
1535         }
1536
1537         /* Lock the tape drive door so user can't eject. */
1538         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1539                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1540                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1541                                 tape->door_locked = DOOR_LOCKED;
1542                 }
1543         }
1544         unlock_kernel();
1545         return 0;
1546
1547 out_put_tape:
1548         ide_tape_put(tape);
1549         unlock_kernel();
1550         return retval;
1551 }
1552
1553 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1554 {
1555         idetape_tape_t *tape = drive->driver_data;
1556
1557         ide_tape_flush_merge_buffer(drive);
1558         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1559         if (tape->buf != NULL) {
1560                 idetape_pad_zeros(drive, tape->blk_size *
1561                                 (tape->user_bs_factor - 1));
1562                 kfree(tape->buf);
1563                 tape->buf = NULL;
1564         }
1565         idetape_write_filemark(drive);
1566         idetape_flush_tape_buffers(drive);
1567         idetape_flush_tape_buffers(drive);
1568 }
1569
1570 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1571 {
1572         struct ide_tape_obj *tape = filp->private_data;
1573         ide_drive_t *drive = tape->drive;
1574         unsigned int minor = iminor(inode);
1575
1576         lock_kernel();
1577         tape = drive->driver_data;
1578
1579         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1580
1581         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1582                 idetape_write_release(drive, minor);
1583         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1584                 if (minor < 128)
1585                         ide_tape_discard_merge_buffer(drive, 1);
1586         }
1587
1588         if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags))
1589                 (void) idetape_rewind_tape(drive);
1590         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1591                 if (tape->door_locked == DOOR_LOCKED) {
1592                         if (!ide_set_media_lock(drive, tape->disk, 0))
1593                                 tape->door_locked = DOOR_UNLOCKED;
1594                 }
1595         }
1596         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1597         ide_tape_put(tape);
1598         unlock_kernel();
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(debug_mask, debug_mask);
1715 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1716
1717 ide_tape_devset_r_field(avg_speed, avg_speed);
1718 ide_tape_devset_r_field(speed, caps[14]);
1719 ide_tape_devset_r_field(buffer, caps[16]);
1720 ide_tape_devset_r_field(buffer_size, buffer_size);
1721
1722 static const struct ide_proc_devset idetape_settings[] = {
1723         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1724         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1725         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1726         __IDE_PROC_DEVSET(debug_mask,   0, 0xffff, NULL, NULL),
1727         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1728         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1729         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1730                                         mulf_tdsc, divf_tdsc),
1731         { NULL },
1732 };
1733 #endif
1734
1735 /*
1736  * The function below is called to:
1737  *
1738  * 1. Initialize our various state variables.
1739  * 2. Ask the tape for its capabilities.
1740  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1741  * is chosen based on the recommendation which we received in step 2.
1742  *
1743  * Note that at this point ide.c already assigned us an irq, so that we can
1744  * queue requests here and wait for their completion.
1745  */
1746 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1747 {
1748         unsigned long t;
1749         int speed;
1750         int buffer_size;
1751         u16 *ctl = (u16 *)&tape->caps[12];
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 proc_idetape_read_name
1841         (char *page, char **start, off_t off, int count, int *eof, void *data)
1842 {
1843         ide_drive_t     *drive = (ide_drive_t *) data;
1844         idetape_tape_t  *tape = drive->driver_data;
1845         char            *out = page;
1846         int             len;
1847
1848         len = sprintf(out, "%s\n", tape->name);
1849         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
1850 }
1851
1852 static ide_proc_entry_t idetape_proc[] = {
1853         { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
1854         { "name",       S_IFREG|S_IRUGO,        proc_idetape_read_name, NULL },
1855         { NULL, 0, NULL, NULL }
1856 };
1857
1858 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1859 {
1860         return idetape_proc;
1861 }
1862
1863 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1864 {
1865         return idetape_settings;
1866 }
1867 #endif
1868
1869 static int ide_tape_probe(ide_drive_t *);
1870
1871 static struct ide_driver idetape_driver = {
1872         .gen_driver = {
1873                 .owner          = THIS_MODULE,
1874                 .name           = "ide-tape",
1875                 .bus            = &ide_bus_type,
1876         },
1877         .probe                  = ide_tape_probe,
1878         .remove                 = ide_tape_remove,
1879         .version                = IDETAPE_VERSION,
1880         .do_request             = idetape_do_request,
1881 #ifdef CONFIG_IDE_PROC_FS
1882         .proc_entries           = ide_tape_proc_entries,
1883         .proc_devsets           = ide_tape_proc_devsets,
1884 #endif
1885 };
1886
1887 /* Our character device supporting functions, passed to register_chrdev. */
1888 static const struct file_operations idetape_fops = {
1889         .owner          = THIS_MODULE,
1890         .read           = idetape_chrdev_read,
1891         .write          = idetape_chrdev_write,
1892         .ioctl          = idetape_chrdev_ioctl,
1893         .open           = idetape_chrdev_open,
1894         .release        = idetape_chrdev_release,
1895 };
1896
1897 static int idetape_open(struct block_device *bdev, fmode_t mode)
1898 {
1899         struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk);
1900
1901         if (!tape)
1902                 return -ENXIO;
1903
1904         return 0;
1905 }
1906
1907 static int idetape_release(struct gendisk *disk, fmode_t mode)
1908 {
1909         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1910
1911         ide_tape_put(tape);
1912         return 0;
1913 }
1914
1915 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1916                         unsigned int cmd, unsigned long arg)
1917 {
1918         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1919         ide_drive_t *drive = tape->drive;
1920         int err = generic_ide_ioctl(drive, bdev, cmd, arg);
1921         if (err == -EINVAL)
1922                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1923         return err;
1924 }
1925
1926 static struct block_device_operations idetape_block_ops = {
1927         .owner          = THIS_MODULE,
1928         .open           = idetape_open,
1929         .release        = idetape_release,
1930         .locked_ioctl   = idetape_ioctl,
1931 };
1932
1933 static int ide_tape_probe(ide_drive_t *drive)
1934 {
1935         idetape_tape_t *tape;
1936         struct gendisk *g;
1937         int minor;
1938
1939         if (!strstr("ide-tape", drive->driver_req))
1940                 goto failed;
1941
1942         if (drive->media != ide_tape)
1943                 goto failed;
1944
1945         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1946             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1947                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1948                                 " the driver\n", drive->name);
1949                 goto failed;
1950         }
1951         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1952         if (tape == NULL) {
1953                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1954                                 drive->name);
1955                 goto failed;
1956         }
1957
1958         g = alloc_disk(1 << PARTN_BITS);
1959         if (!g)
1960                 goto out_free_tape;
1961
1962         ide_init_disk(g, drive);
1963
1964         tape->dev.parent = &drive->gendev;
1965         tape->dev.release = ide_tape_release;
1966         dev_set_name(&tape->dev, dev_name(&drive->gendev));
1967
1968         if (device_register(&tape->dev))
1969                 goto out_free_disk;
1970
1971         tape->drive = drive;
1972         tape->driver = &idetape_driver;
1973         tape->disk = g;
1974
1975         g->private_data = &tape->driver;
1976
1977         drive->driver_data = tape;
1978
1979         mutex_lock(&idetape_ref_mutex);
1980         for (minor = 0; idetape_devs[minor]; minor++)
1981                 ;
1982         idetape_devs[minor] = tape;
1983         mutex_unlock(&idetape_ref_mutex);
1984
1985         idetape_setup(drive, tape, minor);
1986
1987         device_create(idetape_sysfs_class, &drive->gendev,
1988                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
1989         device_create(idetape_sysfs_class, &drive->gendev,
1990                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
1991                       "n%s", tape->name);
1992
1993         g->fops = &idetape_block_ops;
1994         ide_register_region(g);
1995
1996         return 0;
1997
1998 out_free_disk:
1999         put_disk(g);
2000 out_free_tape:
2001         kfree(tape);
2002 failed:
2003         return -ENODEV;
2004 }
2005
2006 static void __exit idetape_exit(void)
2007 {
2008         driver_unregister(&idetape_driver.gen_driver);
2009         class_destroy(idetape_sysfs_class);
2010         unregister_chrdev(IDETAPE_MAJOR, "ht");
2011 }
2012
2013 static int __init idetape_init(void)
2014 {
2015         int error = 1;
2016         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2017         if (IS_ERR(idetape_sysfs_class)) {
2018                 idetape_sysfs_class = NULL;
2019                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2020                 error = -EBUSY;
2021                 goto out;
2022         }
2023
2024         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2025                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2026                                 " interface\n");
2027                 error = -EBUSY;
2028                 goto out_free_class;
2029         }
2030
2031         error = driver_register(&idetape_driver.gen_driver);
2032         if (error)
2033                 goto out_free_driver;
2034
2035         return 0;
2036
2037 out_free_driver:
2038         driver_unregister(&idetape_driver.gen_driver);
2039 out_free_class:
2040         class_destroy(idetape_sysfs_class);
2041 out:
2042         return error;
2043 }
2044
2045 MODULE_ALIAS("ide:*m-tape*");
2046 module_init(idetape_init);
2047 module_exit(idetape_exit);
2048 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2049 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2050 MODULE_LICENSE("GPL");