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   1 /*
   2  * IDE ATAPI streaming tape driver.
   3  *
   4  * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
   5  * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
   6  *
   7  * This driver was constructed as a student project in the software laboratory
   8  * of the faculty of electrical engineering in the Technion - Israel's
   9  * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
  10  *
  11  * It is hereby placed under the terms of the GNU general public license.
  12  * (See linux/COPYING).
  13  *
  14  * For a historical changelog see
  15  * Documentation/ide/ChangeLog.ide-tape.1995-2002
  16  */
  17
  18 #define DRV_NAME "ide-tape"
  19
  20 #define IDETAPE_VERSION "1.20"
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/kernel.h>
  26 #include <linux/delay.h>
  27 #include <linux/timer.h>
  28 #include <linux/mm.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/major.h>
  32 #include <linux/errno.h>
  33 #include <linux/genhd.h>
  34 #include <linux/slab.h>
  35 #include <linux/pci.h>
  36 #include <linux/ide.h>
  37 #include <linux/smp_lock.h>
  38 #include <linux/completion.h>
  39 #include <linux/bitops.h>
  40 #include <linux/mutex.h>
  41 #include <scsi/scsi.h>
  42
  43 #include <asm/byteorder.h>
  44 #include <linux/irq.h>
  45 #include <linux/uaccess.h>
  46 #include <linux/io.h>
  47 #include <asm/unaligned.h>
  48 #include <linux/mtio.h>
  49
  50 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, u8 *sense)
 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
 297         tape->sense_key = sense[2] & 0xF;
 298         tape->asc       = sense[12];
 299         tape->ascq      = sense[13];
 300
 301         debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
 302                  pc->c[0], tape->sense_key, tape->asc, tape->ascq);
 303
 304         /* correct remaining bytes to transfer */
 305         if (pc->flags & PC_FLAG_DMA_ERROR)
 306                 rq->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
 307
 308         /*
 309          * If error was the result of a zero-length read or write command,
 310          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
 311          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
 312          */
 313         if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
 314             /* length == 0 */
 315             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
 316                 if (tape->sense_key == 5) {
 317                         /* don't report an error, everything's ok */
 318                         pc->error = 0;
 319                         /* don't retry read/write */
 320                         pc->flags |= PC_FLAG_ABORT;
 321                 }
 322         }
 323         if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
 324                 pc->error = IDE_DRV_ERROR_FILEMARK;
 325                 pc->flags |= PC_FLAG_ABORT;
 326         }
 327         if (pc->c[0] == WRITE_6) {
 328                 if ((sense[2] & 0x40) || (tape->sense_key == 0xd
 329                      && tape->asc == 0x0 && tape->ascq == 0x2)) {
 330                         pc->error = IDE_DRV_ERROR_EOD;
 331                         pc->flags |= PC_FLAG_ABORT;
 332                 }
 333         }
 334         if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 335                 if (tape->sense_key == 8) {
 336                         pc->error = IDE_DRV_ERROR_EOD;
 337                         pc->flags |= PC_FLAG_ABORT;
 338                 }
 339                 if (!(pc->flags & PC_FLAG_ABORT) &&
 340                     (blk_rq_bytes(rq) - rq->resid_len))
 341                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
 342         }
 343 }
 344
 345 static void ide_tape_handle_dsc(ide_drive_t *);
 346
 347 static int ide_tape_callback(ide_drive_t *drive, int dsc)
 348 {
 349         idetape_tape_t *tape = drive->driver_data;
 350         struct ide_atapi_pc *pc = drive->pc;
 351         struct request *rq = drive->hwif->rq;
 352         int uptodate = pc->error ? 0 : 1;
 353         int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 354
 355         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 356
 357         if (dsc)
 358                 ide_tape_handle_dsc(drive);
 359
 360         if (drive->failed_pc == pc)
 361                 drive->failed_pc = NULL;
 362
 363         if (pc->c[0] == REQUEST_SENSE) {
 364                 if (uptodate)
 365                         idetape_analyze_error(drive, pc->buf);
 366                 else
 367                         printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
 368                                         "itself - Aborting request!\n");
 369         } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 370                 unsigned int blocks =
 371                         (blk_rq_bytes(rq) - rq->resid_len) / tape->blk_size;
 372
 373                 tape->avg_size += blocks * tape->blk_size;
 374
 375                 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
 376                         tape->avg_speed = tape->avg_size * HZ /
 377                                 (jiffies - tape->avg_time) / 1024;
 378                         tape->avg_size = 0;
 379                         tape->avg_time = jiffies;
 380                 }
 381
 382                 tape->first_frame += blocks;
 383
 384                 if (pc->error) {
 385                         uptodate = 0;
 386                         err = pc->error;
 387                 }
 388         } else if (pc->c[0] == READ_POSITION && uptodate) {
 389                 u8 *readpos = pc->buf;
 390
 391                 debug_log(DBG_SENSE, "BOP - %s\n",
 392                                 (readpos[0] & 0x80) ? "Yes" : "No");
 393                 debug_log(DBG_SENSE, "EOP - %s\n",
 394                                 (readpos[0] & 0x40) ? "Yes" : "No");
 395
 396                 if (readpos[0] & 0x4) {
 397                         printk(KERN_INFO "ide-tape: Block location is unknown"
 398                                          "to the tape\n");
 399                         clear_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
 400                         uptodate = 0;
 401                         err = IDE_DRV_ERROR_GENERAL;
 402                 } else {
 403                         debug_log(DBG_SENSE, "Block Location - %u\n",
 404                                         be32_to_cpup((__be32 *)&readpos[4]));
 405
 406                         tape->partition = readpos[1];
 407                         tape->first_frame = be32_to_cpup((__be32 *)&readpos[4]);
 408                         set_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
 409                 }
 410         }
 411
 412         rq->errors = err;
 413
 414         return uptodate;
 415 }
 416
 417 /*
 418  * Postpone the current request so that ide.c will be able to service requests
 419  * from another device on the same port while we are polling for DSC.
 420  */
 421 static void idetape_postpone_request(ide_drive_t *drive)
 422 {
 423         idetape_tape_t *tape = drive->driver_data;
 424
 425         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 426
 427         tape->postponed_rq = drive->hwif->rq;
 428
 429         ide_stall_queue(drive, tape->dsc_poll_freq);
 430 }
 431
 432 static void ide_tape_handle_dsc(ide_drive_t *drive)
 433 {
 434         idetape_tape_t *tape = drive->driver_data;
 435
 436         /* Media access command */
 437         tape->dsc_polling_start = jiffies;
 438         tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
 439         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
 440         /* Allow ide.c to handle other requests */
 441         idetape_postpone_request(drive);
 442 }
 443
 444 /*
 445  * Packet Command Interface
 446  *
 447  * The current Packet Command is available in drive->pc, and will not change
 448  * until we finish handling it. Each packet command is associated with a
 449  * callback function that will be called when the command is finished.
 450  *
 451  * The handling will be done in three stages:
 452  *
 453  * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
 454  * the interrupt handler to ide_pc_intr.
 455  *
 456  * 2. On each interrupt, ide_pc_intr will be called. This step will be
 457  * repeated until the device signals us that no more interrupts will be issued.
 458  *
 459  * 3. ATAPI Tape media access commands have immediate status with a delayed
 460  * process. In case of a successful initiation of a media access packet command,
 461  * the DSC bit will be set when the actual execution of the command is finished.
 462  * Since the tape drive will not issue an interrupt, we have to poll for this
 463  * event. In this case, we define the request as "low priority request" by
 464  * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 465  * exit the driver.
 466  *
 467  * ide.c will then give higher priority to requests which originate from the
 468  * other device, until will change rq_status to RQ_ACTIVE.
 469  *
 470  * 4. When the packet command is finished, it will be checked for errors.
 471  *
 472  * 5. In case an error was found, we queue a request sense packet command in
 473  * front of the request queue and retry the operation up to
 474  * IDETAPE_MAX_PC_RETRIES times.
 475  *
 476  * 6. In case no error was found, or we decided to give up and not to retry
 477  * again, the callback function will be called and then we will handle the next
 478  * request.
 479  */
 480
 481 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 482                                          struct ide_cmd *cmd,
 483                                          struct ide_atapi_pc *pc)
 484 {
 485         idetape_tape_t *tape = drive->driver_data;
 486         struct request *rq = drive->hwif->rq;
 487
 488         if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
 489                 drive->failed_pc = pc;
 490
 491         /* Set the current packet command */
 492         drive->pc = pc;
 493
 494         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
 495                 (pc->flags & PC_FLAG_ABORT)) {
 496
 497                 /*
 498                  * We will "abort" retrying a packet command in case legitimate
 499                  * error code was received (crossing a filemark, or end of the
 500                  * media, for example).
 501                  */
 502                 if (!(pc->flags & PC_FLAG_ABORT)) {
 503                         if (!(pc->c[0] == TEST_UNIT_READY &&
 504                               tape->sense_key == 2 && tape->asc == 4 &&
 505                              (tape->ascq == 1 || tape->ascq == 8))) {
 506                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
 507                                                 "pc = %2x, key = %2x, "
 508                                                 "asc = %2x, ascq = %2x\n",
 509                                                 tape->name, pc->c[0],
 510                                                 tape->sense_key, tape->asc,
 511                                                 tape->ascq);
 512                         }
 513                         /* Giving up */
 514                         pc->error = IDE_DRV_ERROR_GENERAL;
 515                 }
 516
 517                 drive->failed_pc = NULL;
 518                 drive->pc_callback(drive, 0);
 519                 ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
 520                 return ide_stopped;
 521         }
 522         debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
 523
 524         pc->retries++;
 525
 526         return ide_issue_pc(drive, cmd);
 527 }
 528
 529 /* A mode sense command is used to "sense" tape parameters. */
 530 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 531 {
 532         ide_init_pc(pc);
 533         pc->c[0] = MODE_SENSE;
 534         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
 535                 /* DBD = 1 - Don't return block descriptors */
 536                 pc->c[1] = 8;
 537         pc->c[2] = page_code;
 538         /*
 539          * Changed pc->c[3] to 0 (255 will at best return unused info).
 540          *
 541          * For SCSI this byte is defined as subpage instead of high byte
 542          * of length and some IDE drives seem to interpret it this way
 543          * and return an error when 255 is used.
 544          */
 545         pc->c[3] = 0;
 546         /* We will just discard data in that case */
 547         pc->c[4] = 255;
 548         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
 549                 pc->req_xfer = 12;
 550         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
 551                 pc->req_xfer = 24;
 552         else
 553                 pc->req_xfer = 50;
 554 }
 555
 556 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 557 {
 558         ide_hwif_t *hwif = drive->hwif;
 559         idetape_tape_t *tape = drive->driver_data;
 560         struct ide_atapi_pc *pc = drive->pc;
 561         u8 stat;
 562
 563         stat = hwif->tp_ops->read_status(hwif);
 564
 565         if (stat & ATA_DSC) {
 566                 if (stat & ATA_ERR) {
 567                         /* Error detected */
 568                         if (pc->c[0] != TEST_UNIT_READY)
 569                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
 570                                                 tape->name);
 571                         /* Retry operation */
 572                         ide_retry_pc(drive);
 573                         return ide_stopped;
 574                 }
 575                 pc->error = 0;
 576         } else {
 577                 pc->error = IDE_DRV_ERROR_GENERAL;
 578                 drive->failed_pc = NULL;
 579         }
 580         drive->pc_callback(drive, 0);
 581         return ide_stopped;
 582 }
 583
 584 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
 585                                    struct ide_atapi_pc *pc, struct request *rq,
 586                                    u8 opcode)
 587 {
 588         unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
 589
 590         ide_init_pc(pc);
 591         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
 592         pc->c[1] = 1;
 593         pc->buf = NULL;
 594         pc->buf_size = blk_rq_bytes(rq);
 595         if (pc->buf_size == tape->buffer_size)
 596                 pc->flags |= PC_FLAG_DMA_OK;
 597
 598         if (opcode == READ_6)
 599                 pc->c[0] = READ_6;
 600         else if (opcode == WRITE_6) {
 601                 pc->c[0] = WRITE_6;
 602                 pc->flags |= PC_FLAG_WRITING;
 603         }
 604
 605         memcpy(rq->cmd, pc->c, 12);
 606 }
 607
 608 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 609                                           struct request *rq, sector_t block)
 610 {
 611         ide_hwif_t *hwif = drive->hwif;
 612         idetape_tape_t *tape = drive->driver_data;
 613         struct ide_atapi_pc *pc = NULL;
 614         struct request *postponed_rq = tape->postponed_rq;
 615         struct ide_cmd cmd;
 616         u8 stat;
 617
 618         debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %u\n"
 619                   (unsigned long long)blk_rq_pos(rq), blk_rq_sectors(rq));
 620
 621         if (!(blk_special_request(rq) || blk_sense_request(rq))) {
 622                 /* We do not support buffer cache originated requests. */
 623                 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
 624                         "request queue (%d)\n", drive->name, rq->cmd_type);
 625                 if (blk_fs_request(rq) == 0 && rq->errors == 0)
 626                         rq->errors = -EIO;
 627                 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
 628                 return ide_stopped;
 629         }
 630
 631         /* Retry a failed packet command */
 632         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 633                 pc = drive->failed_pc;
 634                 goto out;
 635         }
 636
 637         if (postponed_rq != NULL)
 638                 if (rq != postponed_rq) {
 639                         printk(KERN_ERR "ide-tape: ide-tape.c bug - "
 640                                         "Two DSC requests were queued\n");
 641                         drive->failed_pc = NULL;
 642                         rq->errors = 0;
 643                         ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 644                         return ide_stopped;
 645                 }
 646
 647         tape->postponed_rq = NULL;
 648
 649         /*
 650          * If the tape is still busy, postpone our request and service
 651          * the other device meanwhile.
 652          */
 653         stat = hwif->tp_ops->read_status(hwif);
 654
 655         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 656             (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
 657                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 658
 659         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 660                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 661                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 662         }
 663
 664         if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) &&
 665             (stat & ATA_DSC) == 0) {
 666                 if (postponed_rq == NULL) {
 667                         tape->dsc_polling_start = jiffies;
 668                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 669                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 670                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 671                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 672                                 tape->name);
 673                         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 674                                 idetape_media_access_finished(drive);
 675                                 return ide_stopped;
 676                         } else {
 677                                 return ide_do_reset(drive);
 678                         }
 679                 } else if (time_after(jiffies,
 680                                         tape->dsc_polling_start +
 681                                         IDETAPE_DSC_MA_THRESHOLD))
 682                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 683                 idetape_postpone_request(drive);
 684                 return ide_stopped;
 685         }
 686         if (rq->cmd[13] & REQ_IDETAPE_READ) {
 687                 pc = &tape->queued_pc;
 688                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 689                 goto out;
 690         }
 691         if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
 692                 pc = &tape->queued_pc;
 693                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 694                 goto out;
 695         }
 696         if (rq->cmd[13] & REQ_IDETAPE_PC1) {
 697                 pc = (struct ide_atapi_pc *)rq->special;
 698                 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
 699                 rq->cmd[13] |= REQ_IDETAPE_PC2;
 700                 goto out;
 701         }
 702         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 703                 idetape_media_access_finished(drive);
 704                 return ide_stopped;
 705         }
 706         BUG();
 707
 708 out:
 709         /* prepare sense request for this command */
 710         ide_prep_sense(drive, rq);
 711
 712         memset(&cmd, 0, sizeof(cmd));
 713
 714         if (rq_data_dir(rq))
 715                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 716
 717         cmd.rq = rq;
 718
 719         ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
 720         ide_map_sg(drive, &cmd);
 721
 722         return ide_tape_issue_pc(drive, &cmd, pc);
 723 }
 724
 725 /*
 726  * Write a filemark if write_filemark=1. Flush the device buffers without
 727  * writing a filemark otherwise.
 728  */
 729 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 730                 struct ide_atapi_pc *pc, int write_filemark)
 731 {
 732         ide_init_pc(pc);
 733         pc->c[0] = WRITE_FILEMARKS;
 734         pc->c[4] = write_filemark;
 735         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 736 }
 737
 738 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 739 {
 740         idetape_tape_t *tape = drive->driver_data;
 741         struct gendisk *disk = tape->disk;
 742         int load_attempted = 0;
 743
 744         /* Wait for the tape to become ready */
 745         set_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
 746         timeout += jiffies;
 747         while (time_before(jiffies, timeout)) {
 748                 if (ide_do_test_unit_ready(drive, disk) == 0)
 749                         return 0;
 750                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 751                     || (tape->asc == 0x3A)) {
 752                         /* no media */
 753                         if (load_attempted)
 754                                 return -ENOMEDIUM;
 755                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 756                         load_attempted = 1;
 757                 /* not about to be ready */
 758                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 759                              (tape->ascq == 1 || tape->ascq == 8)))
 760                         return -EIO;
 761                 msleep(100);
 762         }
 763         return -EIO;
 764 }
 765
 766 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 767 {
 768         struct ide_tape_obj *tape = drive->driver_data;
 769         struct ide_atapi_pc pc;
 770         int rc;
 771
 772         idetape_create_write_filemark_cmd(drive, &pc, 0);
 773         rc = ide_queue_pc_tail(drive, tape->disk, &pc);
 774         if (rc)
 775                 return rc;
 776         idetape_wait_ready(drive, 60 * 5 * HZ);
 777         return 0;
 778 }
 779
 780 static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc)
 781 {
 782         ide_init_pc(pc);
 783         pc->c[0] = READ_POSITION;
 784         pc->req_xfer = 20;
 785 }
 786
 787 static int idetape_read_position(ide_drive_t *drive)
 788 {
 789         idetape_tape_t *tape = drive->driver_data;
 790         struct ide_atapi_pc pc;
 791         int position;
 792
 793         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 794
 795         idetape_create_read_position_cmd(&pc);
 796         if (ide_queue_pc_tail(drive, tape->disk, &pc))
 797                 return -1;
 798         position = tape->first_frame;
 799         return position;
 800 }
 801
 802 static void idetape_create_locate_cmd(ide_drive_t *drive,
 803                 struct ide_atapi_pc *pc,
 804                 unsigned int block, u8 partition, int skip)
 805 {
 806         ide_init_pc(pc);
 807         pc->c[0] = POSITION_TO_ELEMENT;
 808         pc->c[1] = 2;
 809         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 810         pc->c[8] = partition;
 811         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 812 }
 813
 814 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 815 {
 816         idetape_tape_t *tape = drive->driver_data;
 817
 818         if (tape->chrdev_dir != IDETAPE_DIR_READ)
 819                 return;
 820
 821         clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags);
 822         tape->valid = 0;
 823         if (tape->buf != NULL) {
 824                 kfree(tape->buf);
 825                 tape->buf = NULL;
 826         }
 827
 828         tape->chrdev_dir = IDETAPE_DIR_NONE;
 829 }
 830
 831 /*
 832  * Position the tape to the requested block using the LOCATE packet command.
 833  * A READ POSITION command is then issued to check where we are positioned. Like
 834  * all higher level operations, we queue the commands at the tail of the request
 835  * queue and wait for their completion.
 836  */
 837 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 838                 u8 partition, int skip)
 839 {
 840         idetape_tape_t *tape = drive->driver_data;
 841         struct gendisk *disk = tape->disk;
 842         int retval;
 843         struct ide_atapi_pc pc;
 844
 845         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 846                 __ide_tape_discard_merge_buffer(drive);
 847         idetape_wait_ready(drive, 60 * 5 * HZ);
 848         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 849         retval = ide_queue_pc_tail(drive, disk, &pc);
 850         if (retval)
 851                 return (retval);
 852
 853         idetape_create_read_position_cmd(&pc);
 854         return ide_queue_pc_tail(drive, disk, &pc);
 855 }
 856
 857 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 858                                           int restore_position)
 859 {
 860         idetape_tape_t *tape = drive->driver_data;
 861         int seek, position;
 862
 863         __ide_tape_discard_merge_buffer(drive);
 864         if (restore_position) {
 865                 position = idetape_read_position(drive);
 866                 seek = position > 0 ? position : 0;
 867                 if (idetape_position_tape(drive, seek, 0, 0)) {
 868                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 869                                          " %s\n", tape->name, __func__);
 870                         return;
 871                 }
 872         }
 873 }
 874
 875 /*
 876  * Generate a read/write request for the block device interface and wait for it
 877  * to be serviced.
 878  */
 879 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 880 {
 881         idetape_tape_t *tape = drive->driver_data;
 882         struct request *rq;
 883         int ret;
 884
 885         debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
 886         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 887         BUG_ON(size < 0 || size % tape->blk_size);
 888
 889         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
 890         rq->cmd_type = REQ_TYPE_SPECIAL;
 891         rq->cmd[13] = cmd;
 892         rq->rq_disk = tape->disk;
 893
 894         if (size) {
 895                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 896                                       __GFP_WAIT);
 897                 if (ret)
 898                         goto out_put;
 899         }
 900
 901         blk_execute_rq(drive->queue, tape->disk, rq, 0);
 902
 903         /* calculate the number of transferred bytes and update buffer state */
 904         size -= rq->resid_len;
 905         tape->cur = tape->buf;
 906         if (cmd == REQ_IDETAPE_READ)
 907                 tape->valid = size;
 908         else
 909                 tape->valid = 0;
 910
 911         ret = size;
 912         if (rq->errors == IDE_DRV_ERROR_GENERAL)
 913                 ret = -EIO;
 914 out_put:
 915         blk_put_request(rq);
 916         return ret;
 917 }
 918
 919 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 920 {
 921         ide_init_pc(pc);
 922         pc->c[0] = INQUIRY;
 923         pc->c[4] = 254;
 924         pc->req_xfer = 254;
 925 }
 926
 927 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 928                 struct ide_atapi_pc *pc)
 929 {
 930         ide_init_pc(pc);
 931         pc->c[0] = REZERO_UNIT;
 932         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 933 }
 934
 935 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 936 {
 937         ide_init_pc(pc);
 938         pc->c[0] = ERASE;
 939         pc->c[1] = 1;
 940         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 941 }
 942
 943 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 944 {
 945         ide_init_pc(pc);
 946         pc->c[0] = SPACE;
 947         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 948         pc->c[1] = cmd;
 949         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 950 }
 951
 952 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 953 {
 954         idetape_tape_t *tape = drive->driver_data;
 955
 956         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 957                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 958                                 " but we are not writing.\n");
 959                 return;
 960         }
 961         if (tape->buf) {
 962                 size_t aligned = roundup(tape->valid, tape->blk_size);
 963
 964                 memset(tape->cur, 0, aligned - tape->valid);
 965                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 966                 kfree(tape->buf);
 967                 tape->buf = NULL;
 968         }
 969         tape->chrdev_dir = IDETAPE_DIR_NONE;
 970 }
 971
 972 static int idetape_init_rw(ide_drive_t *drive, int dir)
 973 {
 974         idetape_tape_t *tape = drive->driver_data;
 975         int rc;
 976
 977         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 978
 979         if (tape->chrdev_dir == dir)
 980                 return 0;
 981
 982         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 983                 ide_tape_discard_merge_buffer(drive, 1);
 984         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 985                 ide_tape_flush_merge_buffer(drive);
 986                 idetape_flush_tape_buffers(drive);
 987         }
 988
 989         if (tape->buf || tape->valid) {
 990                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 991                 tape->valid = 0;
 992         }
 993
 994         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 995         if (!tape->buf)
 996                 return -ENOMEM;
 997         tape->chrdev_dir = dir;
 998         tape->cur = tape->buf;
 999
1000         /*
1001          * Issue a 0 rw command to ensure that DSC handshake is
1002          * switched from completion mode to buffer available mode.  No
1003          * point in issuing this if DSC overlap isn't supported, some
1004          * drives (Seagate STT3401A) will return an error.
1005          */
1006         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1007                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
1008                                                   : REQ_IDETAPE_WRITE;
1009
1010                 rc = idetape_queue_rw_tail(drive, cmd, 0);
1011                 if (rc < 0) {
1012                         kfree(tape->buf);
1013                         tape->buf = NULL;
1014                         tape->chrdev_dir = IDETAPE_DIR_NONE;
1015                         return rc;
1016                 }
1017         }
1018
1019         return 0;
1020 }
1021
1022 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
1023 {
1024         idetape_tape_t *tape = drive->driver_data;
1025
1026         memset(tape->buf, 0, tape->buffer_size);
1027
1028         while (bcount) {
1029                 unsigned int count = min(tape->buffer_size, bcount);
1030
1031                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1032                 bcount -= count;
1033         }
1034 }
1035
1036 /*
1037  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1038  * currently support only one partition.
1039  */
1040 static int idetape_rewind_tape(ide_drive_t *drive)
1041 {
1042         struct ide_tape_obj *tape = drive->driver_data;
1043         struct gendisk *disk = tape->disk;
1044         int retval;
1045         struct ide_atapi_pc pc;
1046
1047         debug_log(DBG_SENSE, "Enter %s\n", __func__);
1048
1049         idetape_create_rewind_cmd(drive, &pc);
1050         retval = ide_queue_pc_tail(drive, disk, &pc);
1051         if (retval)
1052                 return retval;
1053
1054         idetape_create_read_position_cmd(&pc);
1055         retval = ide_queue_pc_tail(drive, disk, &pc);
1056         if (retval)
1057                 return retval;
1058         return 0;
1059 }
1060
1061 /* mtio.h compatible commands should be issued to the chrdev interface. */
1062 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1063                                 unsigned long arg)
1064 {
1065         idetape_tape_t *tape = drive->driver_data;
1066         void __user *argp = (void __user *)arg;
1067
1068         struct idetape_config {
1069                 int dsc_rw_frequency;
1070                 int dsc_media_access_frequency;
1071                 int nr_stages;
1072         } config;
1073
1074         debug_log(DBG_PROCS, "Enter %s\n", __func__);
1075
1076         switch (cmd) {
1077         case 0x0340:
1078                 if (copy_from_user(&config, argp, sizeof(config)))
1079                         return -EFAULT;
1080                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1081                 break;
1082         case 0x0350:
1083                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1084                 config.nr_stages = 1;
1085                 if (copy_to_user(argp, &config, sizeof(config)))
1086                         return -EFAULT;
1087                 break;
1088         default:
1089                 return -EIO;
1090         }
1091         return 0;
1092 }
1093
1094 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1095                                         int mt_count)
1096 {
1097         idetape_tape_t *tape = drive->driver_data;
1098         struct gendisk *disk = tape->disk;
1099         struct ide_atapi_pc pc;
1100         int retval, count = 0;
1101         int sprev = !!(tape->caps[4] & 0x20);
1102
1103         if (mt_count == 0)
1104                 return 0;
1105         if (MTBSF == mt_op || MTBSFM == mt_op) {
1106                 if (!sprev)
1107                         return -EIO;
1108                 mt_count = -mt_count;
1109         }
1110
1111         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1112                 tape->valid = 0;
1113                 if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1114                         ++count;
1115                 ide_tape_discard_merge_buffer(drive, 0);
1116         }
1117
1118         switch (mt_op) {
1119         case MTFSF:
1120         case MTBSF:
1121                 idetape_create_space_cmd(&pc, mt_count - count,
1122                                          IDETAPE_SPACE_OVER_FILEMARK);
1123                 return ide_queue_pc_tail(drive, disk, &pc);
1124         case MTFSFM:
1125         case MTBSFM:
1126                 if (!sprev)
1127                         return -EIO;
1128                 retval = idetape_space_over_filemarks(drive, MTFSF,
1129                                                       mt_count - count);
1130                 if (retval)
1131                         return retval;
1132                 count = (MTBSFM == mt_op ? 1 : -1);
1133                 return idetape_space_over_filemarks(drive, MTFSF, count);
1134         default:
1135                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1136                                 mt_op);
1137                 return -EIO;
1138         }
1139 }
1140
1141 /*
1142  * Our character device read / write functions.
1143  *
1144  * The tape is optimized to maximize throughput when it is transferring an
1145  * integral number of the "continuous transfer limit", which is a parameter of
1146  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1147  *
1148  * As of version 1.3 of the driver, the character device provides an abstract
1149  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1150  * same backup/restore procedure is supported. The driver will internally
1151  * convert the requests to the recommended transfer unit, so that an unmatch
1152  * between the user's block size to the recommended size will only result in a
1153  * (slightly) increased driver overhead, but will no longer hit performance.
1154  * This is not applicable to Onstream.
1155  */
1156 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1157                                    size_t count, loff_t *ppos)
1158 {
1159         struct ide_tape_obj *tape = file->private_data;
1160         ide_drive_t *drive = tape->drive;
1161         size_t done = 0;
1162         ssize_t ret = 0;
1163         int rc;
1164
1165         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1166
1167         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1168                 if (test_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags))
1169                         if (count > tape->blk_size &&
1170                             (count % tape->blk_size) == 0)
1171                                 tape->user_bs_factor = count / tape->blk_size;
1172         }
1173
1174         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1175         if (rc < 0)
1176                 return rc;
1177
1178         while (done < count) {
1179                 size_t todo;
1180
1181                 /* refill if staging buffer is empty */
1182                 if (!tape->valid) {
1183                         /* If we are at a filemark, nothing more to read */
1184                         if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1185                                 break;
1186                         /* read */
1187                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1188                                                   tape->buffer_size) <= 0)
1189                                 break;
1190                 }
1191
1192                 /* copy out */
1193                 todo = min_t(size_t, count - done, tape->valid);
1194                 if (copy_to_user(buf + done, tape->cur, todo))
1195                         ret = -EFAULT;
1196
1197                 tape->cur += todo;
1198                 tape->valid -= todo;
1199                 done += todo;
1200         }
1201
1202         if (!done && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) {
1203                 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
1204
1205                 idetape_space_over_filemarks(drive, MTFSF, 1);
1206                 return 0;
1207         }
1208
1209         return ret ? ret : done;
1210 }
1211
1212 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1213                                      size_t count, loff_t *ppos)
1214 {
1215         struct ide_tape_obj *tape = file->private_data;
1216         ide_drive_t *drive = tape->drive;
1217         size_t done = 0;
1218         ssize_t ret = 0;
1219         int rc;
1220
1221         /* The drive is write protected. */
1222         if (tape->write_prot)
1223                 return -EACCES;
1224
1225         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1226
1227         /* Initialize write operation */
1228         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1229         if (rc < 0)
1230                 return rc;
1231
1232         while (done < count) {
1233                 size_t todo;
1234
1235                 /* flush if staging buffer is full */
1236                 if (tape->valid == tape->buffer_size &&
1237                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1238                                           tape->buffer_size) <= 0)
1239                         return rc;
1240
1241                 /* copy in */
1242                 todo = min_t(size_t, count - done,
1243                              tape->buffer_size - tape->valid);
1244                 if (copy_from_user(tape->cur, buf + done, todo))
1245                         ret = -EFAULT;
1246
1247                 tape->cur += todo;
1248                 tape->valid += todo;
1249                 done += todo;
1250         }
1251
1252         return ret ? ret : done;
1253 }
1254
1255 static int idetape_write_filemark(ide_drive_t *drive)
1256 {
1257         struct ide_tape_obj *tape = drive->driver_data;
1258         struct ide_atapi_pc pc;
1259
1260         /* Write a filemark */
1261         idetape_create_write_filemark_cmd(drive, &pc, 1);
1262         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1263                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1264                 return -EIO;
1265         }
1266         return 0;
1267 }
1268
1269 /*
1270  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1271  * requested.
1272  *
1273  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1274  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1275  * usually not supported.
1276  *
1277  * The following commands are currently not supported:
1278  *
1279  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1280  * MT_ST_WRITE_THRESHOLD.
1281  */
1282 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1283 {
1284         idetape_tape_t *tape = drive->driver_data;
1285         struct gendisk *disk = tape->disk;
1286         struct ide_atapi_pc pc;
1287         int i, retval;
1288
1289         debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
1290                         mt_op, mt_count);
1291
1292         switch (mt_op) {
1293         case MTFSF:
1294         case MTFSFM:
1295         case MTBSF:
1296         case MTBSFM:
1297                 if (!mt_count)
1298                         return 0;
1299                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1300         default:
1301                 break;
1302         }
1303
1304         switch (mt_op) {
1305         case MTWEOF:
1306                 if (tape->write_prot)
1307                         return -EACCES;
1308                 ide_tape_discard_merge_buffer(drive, 1);
1309                 for (i = 0; i < mt_count; i++) {
1310                         retval = idetape_write_filemark(drive);
1311                         if (retval)
1312                                 return retval;
1313                 }
1314                 return 0;
1315         case MTREW:
1316                 ide_tape_discard_merge_buffer(drive, 0);
1317                 if (idetape_rewind_tape(drive))
1318                         return -EIO;
1319                 return 0;
1320         case MTLOAD:
1321                 ide_tape_discard_merge_buffer(drive, 0);
1322                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1323         case MTUNLOAD:
1324         case MTOFFL:
1325                 /*
1326                  * If door is locked, attempt to unlock before
1327                  * attempting to eject.
1328                  */
1329                 if (tape->door_locked) {
1330                         if (!ide_set_media_lock(drive, disk, 0))
1331                                 tape->door_locked = DOOR_UNLOCKED;
1332                 }
1333                 ide_tape_discard_merge_buffer(drive, 0);
1334                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1335                 if (!retval)
1336                         clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1337                 return retval;
1338         case MTNOP:
1339                 ide_tape_discard_merge_buffer(drive, 0);
1340                 return idetape_flush_tape_buffers(drive);
1341         case MTRETEN:
1342                 ide_tape_discard_merge_buffer(drive, 0);
1343                 return ide_do_start_stop(drive, disk,
1344                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1345         case MTEOM:
1346                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1347                 return ide_queue_pc_tail(drive, disk, &pc);
1348         case MTERASE:
1349                 (void)idetape_rewind_tape(drive);
1350                 idetape_create_erase_cmd(&pc);
1351                 return ide_queue_pc_tail(drive, disk, &pc);
1352         case MTSETBLK:
1353                 if (mt_count) {
1354                         if (mt_count < tape->blk_size ||
1355                             mt_count % tape->blk_size)
1356                                 return -EIO;
1357                         tape->user_bs_factor = mt_count / tape->blk_size;
1358                         clear_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1359                 } else
1360                         set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1361                 return 0;
1362         case MTSEEK:
1363                 ide_tape_discard_merge_buffer(drive, 0);
1364                 return idetape_position_tape(drive,
1365                         mt_count * tape->user_bs_factor, tape->partition, 0);
1366         case MTSETPART:
1367                 ide_tape_discard_merge_buffer(drive, 0);
1368                 return idetape_position_tape(drive, 0, mt_count, 0);
1369         case MTFSR:
1370         case MTBSR:
1371         case MTLOCK:
1372                 retval = ide_set_media_lock(drive, disk, 1);
1373                 if (retval)
1374                         return retval;
1375                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1376                 return 0;
1377         case MTUNLOCK:
1378                 retval = ide_set_media_lock(drive, disk, 0);
1379                 if (retval)
1380                         return retval;
1381                 tape->door_locked = DOOR_UNLOCKED;
1382                 return 0;
1383         default:
1384                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1385                                 mt_op);
1386                 return -EIO;
1387         }
1388 }
1389
1390 /*
1391  * Our character device ioctls. General mtio.h magnetic io commands are
1392  * supported here, and not in the corresponding block interface. Our own
1393  * ide-tape ioctls are supported on both interfaces.
1394  */
1395 static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
1396                                 unsigned int cmd, unsigned long arg)
1397 {
1398         struct ide_tape_obj *tape = file->private_data;
1399         ide_drive_t *drive = tape->drive;
1400         struct mtop mtop;
1401         struct mtget mtget;
1402         struct mtpos mtpos;
1403         int block_offset = 0, position = tape->first_frame;
1404         void __user *argp = (void __user *)arg;
1405
1406         debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
1407
1408         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1409                 ide_tape_flush_merge_buffer(drive);
1410                 idetape_flush_tape_buffers(drive);
1411         }
1412         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1413                 block_offset = tape->valid /
1414                         (tape->blk_size * tape->user_bs_factor);
1415                 position = idetape_read_position(drive);
1416                 if (position < 0)
1417                         return -EIO;
1418         }
1419         switch (cmd) {
1420         case MTIOCTOP:
1421                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1422                         return -EFAULT;
1423                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1424         case MTIOCGET:
1425                 memset(&mtget, 0, sizeof(struct mtget));
1426                 mtget.mt_type = MT_ISSCSI2;
1427                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1428                 mtget.mt_dsreg =
1429                         ((tape->blk_size * tape->user_bs_factor)
1430                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1431
1432                 if (tape->drv_write_prot)
1433                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1434
1435                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1436                         return -EFAULT;
1437                 return 0;
1438         case MTIOCPOS:
1439                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1440                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1441                         return -EFAULT;
1442                 return 0;
1443         default:
1444                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1445                         ide_tape_discard_merge_buffer(drive, 1);
1446                 return idetape_blkdev_ioctl(drive, cmd, arg);
1447         }
1448 }
1449
1450 /*
1451  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1452  * block size with the reported value.
1453  */
1454 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1455 {
1456         idetape_tape_t *tape = drive->driver_data;
1457         struct ide_atapi_pc pc;
1458
1459         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1460         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1461                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1462                 if (tape->blk_size == 0) {
1463                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1464                                             "block size, assuming 32k\n");
1465                         tape->blk_size = 32768;
1466                 }
1467                 return;
1468         }
1469         tape->blk_size = (pc.buf[4 + 5] << 16) +
1470                                 (pc.buf[4 + 6] << 8)  +
1471                                  pc.buf[4 + 7];
1472         tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7;
1473 }
1474
1475 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1476 {
1477         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1478         ide_drive_t *drive;
1479         idetape_tape_t *tape;
1480         int retval;
1481
1482         if (i >= MAX_HWIFS * MAX_DRIVES)
1483                 return -ENXIO;
1484
1485         lock_kernel();
1486         tape = ide_tape_chrdev_get(i);
1487         if (!tape) {
1488                 unlock_kernel();
1489                 return -ENXIO;
1490         }
1491
1492         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1493
1494         /*
1495          * We really want to do nonseekable_open(inode, filp); here, but some
1496          * versions of tar incorrectly call lseek on tapes and bail out if that
1497          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1498          */
1499         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1500
1501         drive = tape->drive;
1502
1503         filp->private_data = tape;
1504
1505         if (test_and_set_bit(IDE_AFLAG_BUSY, &drive->atapi_flags)) {
1506                 retval = -EBUSY;
1507                 goto out_put_tape;
1508         }
1509
1510         retval = idetape_wait_ready(drive, 60 * HZ);
1511         if (retval) {
1512                 clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1513                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1514                 goto out_put_tape;
1515         }
1516
1517         idetape_read_position(drive);
1518         if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags))
1519                 (void)idetape_rewind_tape(drive);
1520
1521         /* Read block size and write protect status from drive. */
1522         ide_tape_get_bsize_from_bdesc(drive);
1523
1524         /* Set write protect flag if device is opened as read-only. */
1525         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1526                 tape->write_prot = 1;
1527         else
1528                 tape->write_prot = tape->drv_write_prot;
1529
1530         /* Make sure drive isn't write protected if user wants to write. */
1531         if (tape->write_prot) {
1532                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1533                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1534                         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1535                         retval = -EROFS;
1536                         goto out_put_tape;
1537                 }
1538         }
1539
1540         /* Lock the tape drive door so user can't eject. */
1541         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1542                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1543                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1544                                 tape->door_locked = DOOR_LOCKED;
1545                 }
1546         }
1547         unlock_kernel();
1548         return 0;
1549
1550 out_put_tape:
1551         ide_tape_put(tape);
1552         unlock_kernel();
1553         return retval;
1554 }
1555
1556 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1557 {
1558         idetape_tape_t *tape = drive->driver_data;
1559
1560         ide_tape_flush_merge_buffer(drive);
1561         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1562         if (tape->buf != NULL) {
1563                 idetape_pad_zeros(drive, tape->blk_size *
1564                                 (tape->user_bs_factor - 1));
1565                 kfree(tape->buf);
1566                 tape->buf = NULL;
1567         }
1568         idetape_write_filemark(drive);
1569         idetape_flush_tape_buffers(drive);
1570         idetape_flush_tape_buffers(drive);
1571 }
1572
1573 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1574 {
1575         struct ide_tape_obj *tape = filp->private_data;
1576         ide_drive_t *drive = tape->drive;
1577         unsigned int minor = iminor(inode);
1578
1579         lock_kernel();
1580         tape = drive->driver_data;
1581
1582         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1583
1584         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1585                 idetape_write_release(drive, minor);
1586         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1587                 if (minor < 128)
1588                         ide_tape_discard_merge_buffer(drive, 1);
1589         }
1590
1591         if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags))
1592                 (void) idetape_rewind_tape(drive);
1593         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1594                 if (tape->door_locked == DOOR_LOCKED) {
1595                         if (!ide_set_media_lock(drive, tape->disk, 0))
1596                                 tape->door_locked = DOOR_UNLOCKED;
1597                 }
1598         }
1599         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1600         ide_tape_put(tape);
1601         unlock_kernel();
1602         return 0;
1603 }
1604
1605 static void idetape_get_inquiry_results(ide_drive_t *drive)
1606 {
1607         idetape_tape_t *tape = drive->driver_data;
1608         struct ide_atapi_pc pc;
1609         u8 pc_buf[256];
1610         char fw_rev[4], vendor_id[8], product_id[16];
1611
1612         idetape_create_inquiry_cmd(&pc);
1613         pc.buf = &pc_buf[0];
1614         pc.buf_size = sizeof(pc_buf);
1615
1616         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1617                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1618                                 tape->name);
1619                 return;
1620         }
1621         memcpy(vendor_id, &pc.buf[8], 8);
1622         memcpy(product_id, &pc.buf[16], 16);
1623         memcpy(fw_rev, &pc.buf[32], 4);
1624
1625         ide_fixstring(vendor_id, 8, 0);
1626         ide_fixstring(product_id, 16, 0);
1627         ide_fixstring(fw_rev, 4, 0);
1628
1629         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1630                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1631 }
1632
1633 /*
1634  * Ask the tape about its various parameters. In particular, we will adjust our
1635  * data transfer buffer size to the recommended value as returned by the tape.
1636  */
1637 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1638 {
1639         idetape_tape_t *tape = drive->driver_data;
1640         struct ide_atapi_pc pc;
1641         u8 *caps;
1642         u8 speed, max_speed;
1643
1644         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1645         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1646                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1647                                 " some default values\n");
1648                 tape->blk_size = 512;
1649                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1650                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1651                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1652                 return;
1653         }
1654         caps = pc.buf + 4 + pc.buf[3];
1655
1656         /* convert to host order and save for later use */
1657         speed = be16_to_cpup((__be16 *)&caps[14]);
1658         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1659
1660         *(u16 *)&caps[8] = max_speed;
1661         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1662         *(u16 *)&caps[14] = speed;
1663         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1664
1665         if (!speed) {
1666                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1667                                 "(assuming 650KB/sec)\n", drive->name);
1668                 *(u16 *)&caps[14] = 650;
1669         }
1670         if (!max_speed) {
1671                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1672                                 "(assuming 650KB/sec)\n", drive->name);
1673                 *(u16 *)&caps[8] = 650;
1674         }
1675
1676         memcpy(&tape->caps, caps, 20);
1677
1678         /* device lacks locking support according to capabilities page */
1679         if ((caps[6] & 1) == 0)
1680                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1681
1682         if (caps[7] & 0x02)
1683                 tape->blk_size = 512;
1684         else if (caps[7] & 0x04)
1685                 tape->blk_size = 1024;
1686 }
1687
1688 #ifdef CONFIG_IDE_PROC_FS
1689 #define ide_tape_devset_get(name, field) \
1690 static int get_##name(ide_drive_t *drive) \
1691 { \
1692         idetape_tape_t *tape = drive->driver_data; \
1693         return tape->field; \
1694 }
1695
1696 #define ide_tape_devset_set(name, field) \
1697 static int set_##name(ide_drive_t *drive, int arg) \
1698 { \
1699         idetape_tape_t *tape = drive->driver_data; \
1700         tape->field = arg; \
1701         return 0; \
1702 }
1703
1704 #define ide_tape_devset_rw_field(_name, _field) \
1705 ide_tape_devset_get(_name, _field) \
1706 ide_tape_devset_set(_name, _field) \
1707 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1708
1709 #define ide_tape_devset_r_field(_name, _field) \
1710 ide_tape_devset_get(_name, _field) \
1711 IDE_DEVSET(_name, 0, get_##_name, NULL)
1712
1713 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1714 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1715 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1716 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1717
1718 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1719
1720 ide_tape_devset_rw_field(debug_mask, debug_mask);
1721 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1722
1723 ide_tape_devset_r_field(avg_speed, avg_speed);
1724 ide_tape_devset_r_field(speed, caps[14]);
1725 ide_tape_devset_r_field(buffer, caps[16]);
1726 ide_tape_devset_r_field(buffer_size, buffer_size);
1727
1728 static const struct ide_proc_devset idetape_settings[] = {
1729         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1730         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1731         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1732         __IDE_PROC_DEVSET(debug_mask,   0, 0xffff, NULL, NULL),
1733         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1734         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1735         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1736                                         mulf_tdsc, divf_tdsc),
1737         { NULL },
1738 };
1739 #endif
1740
1741 /*
1742  * The function below is called to:
1743  *
1744  * 1. Initialize our various state variables.
1745  * 2. Ask the tape for its capabilities.
1746  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1747  * is chosen based on the recommendation which we received in step 2.
1748  *
1749  * Note that at this point ide.c already assigned us an irq, so that we can
1750  * queue requests here and wait for their completion.
1751  */
1752 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1753 {
1754         unsigned long t;
1755         int speed;
1756         int buffer_size;
1757         u16 *ctl = (u16 *)&tape->caps[12];
1758
1759         drive->pc_callback       = ide_tape_callback;
1760
1761         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1762
1763         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1764                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1765                                  tape->name);
1766                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1767         }
1768
1769         /* Seagate Travan drives do not support DSC overlap. */
1770         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1771                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1772
1773         tape->minor = minor;
1774         tape->name[0] = 'h';
1775         tape->name[1] = 't';
1776         tape->name[2] = '0' + minor;
1777         tape->chrdev_dir = IDETAPE_DIR_NONE;
1778
1779         idetape_get_inquiry_results(drive);
1780         idetape_get_mode_sense_results(drive);
1781         ide_tape_get_bsize_from_bdesc(drive);
1782         tape->user_bs_factor = 1;
1783         tape->buffer_size = *ctl * tape->blk_size;
1784         while (tape->buffer_size > 0xffff) {
1785                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1786                 *ctl /= 2;
1787                 tape->buffer_size = *ctl * tape->blk_size;
1788         }
1789         buffer_size = tape->buffer_size;
1790
1791         /* select the "best" DSC read/write polling freq */
1792         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1793
1794         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1795
1796         /*
1797          * Ensure that the number we got makes sense; limit it within
1798          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1799          */
1800         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1801                                          IDETAPE_DSC_RW_MAX);
1802         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1803                 "%lums tDSC%s\n",
1804                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1805                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1806                 tape->buffer_size / 1024,
1807                 tape->best_dsc_rw_freq * 1000 / HZ,
1808                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1809
1810         ide_proc_register_driver(drive, tape->driver);
1811 }
1812
1813 static void ide_tape_remove(ide_drive_t *drive)
1814 {
1815         idetape_tape_t *tape = drive->driver_data;
1816
1817         ide_proc_unregister_driver(drive, tape->driver);
1818         device_del(&tape->dev);
1819         ide_unregister_region(tape->disk);
1820
1821         mutex_lock(&idetape_ref_mutex);
1822         put_device(&tape->dev);
1823         mutex_unlock(&idetape_ref_mutex);
1824 }
1825
1826 static void ide_tape_release(struct device *dev)
1827 {
1828         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1829         ide_drive_t *drive = tape->drive;
1830         struct gendisk *g = tape->disk;
1831
1832         BUG_ON(tape->valid);
1833
1834         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1835         drive->driver_data = NULL;
1836         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1837         device_destroy(idetape_sysfs_class,
1838                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1839         idetape_devs[tape->minor] = NULL;
1840         g->private_data = NULL;
1841         put_disk(g);
1842         kfree(tape);
1843 }
1844
1845 #ifdef CONFIG_IDE_PROC_FS
1846 static int proc_idetape_read_name
1847         (char *page, char **start, off_t off, int count, int *eof, void *data)
1848 {
1849         ide_drive_t     *drive = (ide_drive_t *) data;
1850         idetape_tape_t  *tape = drive->driver_data;
1851         char            *out = page;
1852         int             len;
1853
1854         len = sprintf(out, "%s\n", tape->name);
1855         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
1856 }
1857
1858 static ide_proc_entry_t idetape_proc[] = {
1859         { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
1860         { "name",       S_IFREG|S_IRUGO,        proc_idetape_read_name, NULL },
1861         { NULL, 0, NULL, NULL }
1862 };
1863
1864 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1865 {
1866         return idetape_proc;
1867 }
1868
1869 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1870 {
1871         return idetape_settings;
1872 }
1873 #endif
1874
1875 static int ide_tape_probe(ide_drive_t *);
1876
1877 static struct ide_driver idetape_driver = {
1878         .gen_driver = {
1879                 .owner          = THIS_MODULE,
1880                 .name           = "ide-tape",
1881                 .bus            = &ide_bus_type,
1882         },
1883         .probe                  = ide_tape_probe,
1884         .remove                 = ide_tape_remove,
1885         .version                = IDETAPE_VERSION,
1886         .do_request             = idetape_do_request,
1887 #ifdef CONFIG_IDE_PROC_FS
1888         .proc_entries           = ide_tape_proc_entries,
1889         .proc_devsets           = ide_tape_proc_devsets,
1890 #endif
1891 };
1892
1893 /* Our character device supporting functions, passed to register_chrdev. */
1894 static const struct file_operations idetape_fops = {
1895         .owner          = THIS_MODULE,
1896         .read           = idetape_chrdev_read,
1897         .write          = idetape_chrdev_write,
1898         .ioctl          = idetape_chrdev_ioctl,
1899         .open           = idetape_chrdev_open,
1900         .release        = idetape_chrdev_release,
1901 };
1902
1903 static int idetape_open(struct block_device *bdev, fmode_t mode)
1904 {
1905         struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk);
1906
1907         if (!tape)
1908                 return -ENXIO;
1909
1910         return 0;
1911 }
1912
1913 static int idetape_release(struct gendisk *disk, fmode_t mode)
1914 {
1915         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1916
1917         ide_tape_put(tape);
1918         return 0;
1919 }
1920
1921 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1922                         unsigned int cmd, unsigned long arg)
1923 {
1924         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1925         ide_drive_t *drive = tape->drive;
1926         int err = generic_ide_ioctl(drive, bdev, cmd, arg);
1927         if (err == -EINVAL)
1928                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1929         return err;
1930 }
1931
1932 static struct block_device_operations idetape_block_ops = {
1933         .owner          = THIS_MODULE,
1934         .open           = idetape_open,
1935         .release        = idetape_release,
1936         .locked_ioctl   = idetape_ioctl,
1937 };
1938
1939 static int ide_tape_probe(ide_drive_t *drive)
1940 {
1941         idetape_tape_t *tape;
1942         struct gendisk *g;
1943         int minor;
1944
1945         if (!strstr("ide-tape", drive->driver_req))
1946                 goto failed;
1947
1948         if (drive->media != ide_tape)
1949                 goto failed;
1950
1951         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1952             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1953                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1954                                 " the driver\n", drive->name);
1955                 goto failed;
1956         }
1957         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1958         if (tape == NULL) {
1959                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1960                                 drive->name);
1961                 goto failed;
1962         }
1963
1964         g = alloc_disk(1 << PARTN_BITS);
1965         if (!g)
1966                 goto out_free_tape;
1967
1968         ide_init_disk(g, drive);
1969
1970         tape->dev.parent = &drive->gendev;
1971         tape->dev.release = ide_tape_release;
1972         dev_set_name(&tape->dev, dev_name(&drive->gendev));
1973
1974         if (device_register(&tape->dev))
1975                 goto out_free_disk;
1976
1977         tape->drive = drive;
1978         tape->driver = &idetape_driver;
1979         tape->disk = g;
1980
1981         g->private_data = &tape->driver;
1982
1983         drive->driver_data = tape;
1984
1985         mutex_lock(&idetape_ref_mutex);
1986         for (minor = 0; idetape_devs[minor]; minor++)
1987                 ;
1988         idetape_devs[minor] = tape;
1989         mutex_unlock(&idetape_ref_mutex);
1990
1991         idetape_setup(drive, tape, minor);
1992
1993         device_create(idetape_sysfs_class, &drive->gendev,
1994                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
1995         device_create(idetape_sysfs_class, &drive->gendev,
1996                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
1997                       "n%s", tape->name);
1998
1999         g->fops = &idetape_block_ops;
2000         ide_register_region(g);
2001
2002         return 0;
2003
2004 out_free_disk:
2005         put_disk(g);
2006 out_free_tape:
2007         kfree(tape);
2008 failed:
2009         return -ENODEV;
2010 }
2011
2012 static void __exit idetape_exit(void)
2013 {
2014         driver_unregister(&idetape_driver.gen_driver);
2015         class_destroy(idetape_sysfs_class);
2016         unregister_chrdev(IDETAPE_MAJOR, "ht");
2017 }
2018
2019 static int __init idetape_init(void)
2020 {
2021         int error = 1;
2022         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2023         if (IS_ERR(idetape_sysfs_class)) {
2024                 idetape_sysfs_class = NULL;
2025                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2026                 error = -EBUSY;
2027                 goto out;
2028         }
2029
2030         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2031                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2032                                 " interface\n");
2033                 error = -EBUSY;
2034                 goto out_free_class;
2035         }
2036
2037         error = driver_register(&idetape_driver.gen_driver);
2038         if (error)
2039                 goto out_free_driver;
2040
2041         return 0;
2042
2043 out_free_driver:
2044         driver_unregister(&idetape_driver.gen_driver);
2045 out_free_class:
2046         class_destroy(idetape_sysfs_class);
2047 out:
2048         return error;
2049 }
2050
2051 MODULE_ALIAS("ide:*m-tape*");
2052 module_init(idetape_init);
2053 module_exit(idetape_exit);
2054 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2055 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2056 MODULE_LICENSE("GPL");