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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
 296         tape->sense_key = sense[2] & 0xF;
 297         tape->asc       = sense[12];
 298         tape->ascq      = sense[13];
 299
 300         debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
 301                  pc->c[0], tape->sense_key, tape->asc, tape->ascq);
 302
 303         /* Correct pc->xferred by asking the tape.       */
 304         if (pc->flags & PC_FLAG_DMA_ERROR)
 305                 pc->xferred = pc->req_xfer -
 306                         tape->blk_size *
 307                         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                     pc->xferred)
 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, pc->buf);
 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                 int blocks = pc->xferred / 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                 rq->data_len -= blocks * tape->blk_size;
 384
 385                 if (pc->error) {
 386                         uptodate = 0;
 387                         err = pc->error;
 388                 }
 389         } else if (pc->c[0] == READ_POSITION && uptodate) {
 390                 u8 *readpos = pc->buf;
 391
 392                 debug_log(DBG_SENSE, "BOP - %s\n",
 393                                 (readpos[0] & 0x80) ? "Yes" : "No");
 394                 debug_log(DBG_SENSE, "EOP - %s\n",
 395                                 (readpos[0] & 0x40) ? "Yes" : "No");
 396
 397                 if (readpos[0] & 0x4) {
 398                         printk(KERN_INFO "ide-tape: Block location is unknown"
 399                                          "to the tape\n");
 400                         clear_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
 401                         uptodate = 0;
 402                         err = IDE_DRV_ERROR_GENERAL;
 403                 } else {
 404                         debug_log(DBG_SENSE, "Block Location - %u\n",
 405                                         be32_to_cpup((__be32 *)&readpos[4]));
 406
 407                         tape->partition = readpos[1];
 408                         tape->first_frame = be32_to_cpup((__be32 *)&readpos[4]);
 409                         set_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
 410                 }
 411         }
 412
 413         rq->errors = err;
 414
 415         return uptodate;
 416 }
 417
 418 /*
 419  * Postpone the current request so that ide.c will be able to service requests
 420  * from another device on the same port while we are polling for DSC.
 421  */
 422 static void idetape_postpone_request(ide_drive_t *drive)
 423 {
 424         idetape_tape_t *tape = drive->driver_data;
 425
 426         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 427
 428         tape->postponed_rq = drive->hwif->rq;
 429
 430         ide_stall_queue(drive, tape->dsc_poll_freq);
 431 }
 432
 433 static void ide_tape_handle_dsc(ide_drive_t *drive)
 434 {
 435         idetape_tape_t *tape = drive->driver_data;
 436
 437         /* Media access command */
 438         tape->dsc_polling_start = jiffies;
 439         tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
 440         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
 441         /* Allow ide.c to handle other requests */
 442         idetape_postpone_request(drive);
 443 }
 444
 445 /*
 446  * Packet Command Interface
 447  *
 448  * The current Packet Command is available in drive->pc, and will not change
 449  * until we finish handling it. Each packet command is associated with a
 450  * callback function that will be called when the command is finished.
 451  *
 452  * The handling will be done in three stages:
 453  *
 454  * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
 455  * the interrupt handler to ide_pc_intr.
 456  *
 457  * 2. On each interrupt, ide_pc_intr will be called. This step will be
 458  * repeated until the device signals us that no more interrupts will be issued.
 459  *
 460  * 3. ATAPI Tape media access commands have immediate status with a delayed
 461  * process. In case of a successful initiation of a media access packet command,
 462  * the DSC bit will be set when the actual execution of the command is finished.
 463  * Since the tape drive will not issue an interrupt, we have to poll for this
 464  * event. In this case, we define the request as "low priority request" by
 465  * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 466  * exit the driver.
 467  *
 468  * ide.c will then give higher priority to requests which originate from the
 469  * other device, until will change rq_status to RQ_ACTIVE.
 470  *
 471  * 4. When the packet command is finished, it will be checked for errors.
 472  *
 473  * 5. In case an error was found, we queue a request sense packet command in
 474  * front of the request queue and retry the operation up to
 475  * IDETAPE_MAX_PC_RETRIES times.
 476  *
 477  * 6. In case no error was found, or we decided to give up and not to retry
 478  * again, the callback function will be called and then we will handle the next
 479  * request.
 480  */
 481
 482 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 483                                          struct ide_cmd *cmd,
 484                                          struct ide_atapi_pc *pc)
 485 {
 486         idetape_tape_t *tape = drive->driver_data;
 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                 unsigned int done = blk_rq_bytes(drive->hwif->rq);
 497
 498                 /*
 499                  * We will "abort" retrying a packet command in case legitimate
 500                  * error code was received (crossing a filemark, or end of the
 501                  * media, for example).
 502                  */
 503                 if (!(pc->flags & PC_FLAG_ABORT)) {
 504                         if (!(pc->c[0] == TEST_UNIT_READY &&
 505                               tape->sense_key == 2 && tape->asc == 4 &&
 506                              (tape->ascq == 1 || tape->ascq == 8))) {
 507                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
 508                                                 "pc = %2x, key = %2x, "
 509                                                 "asc = %2x, ascq = %2x\n",
 510                                                 tape->name, pc->c[0],
 511                                                 tape->sense_key, tape->asc,
 512                                                 tape->ascq);
 513                         }
 514                         /* Giving up */
 515                         pc->error = IDE_DRV_ERROR_GENERAL;
 516                 }
 517
 518                 drive->failed_pc = NULL;
 519                 drive->pc_callback(drive, 0);
 520                 ide_complete_rq(drive, -EIO, done);
 521                 return ide_stopped;
 522         }
 523         debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
 524
 525         pc->retries++;
 526
 527         return ide_issue_pc(drive, cmd);
 528 }
 529
 530 /* A mode sense command is used to "sense" tape parameters. */
 531 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 532 {
 533         ide_init_pc(pc);
 534         pc->c[0] = MODE_SENSE;
 535         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
 536                 /* DBD = 1 - Don't return block descriptors */
 537                 pc->c[1] = 8;
 538         pc->c[2] = page_code;
 539         /*
 540          * Changed pc->c[3] to 0 (255 will at best return unused info).
 541          *
 542          * For SCSI this byte is defined as subpage instead of high byte
 543          * of length and some IDE drives seem to interpret it this way
 544          * and return an error when 255 is used.
 545          */
 546         pc->c[3] = 0;
 547         /* We will just discard data in that case */
 548         pc->c[4] = 255;
 549         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
 550                 pc->req_xfer = 12;
 551         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
 552                 pc->req_xfer = 24;
 553         else
 554                 pc->req_xfer = 50;
 555 }
 556
 557 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 558 {
 559         ide_hwif_t *hwif = drive->hwif;
 560         idetape_tape_t *tape = drive->driver_data;
 561         struct ide_atapi_pc *pc = drive->pc;
 562         u8 stat;
 563
 564         stat = hwif->tp_ops->read_status(hwif);
 565
 566         if (stat & ATA_DSC) {
 567                 if (stat & ATA_ERR) {
 568                         /* Error detected */
 569                         if (pc->c[0] != TEST_UNIT_READY)
 570                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
 571                                                 tape->name);
 572                         /* Retry operation */
 573                         ide_retry_pc(drive);
 574                         return ide_stopped;
 575                 }
 576                 pc->error = 0;
 577         } else {
 578                 pc->error = IDE_DRV_ERROR_GENERAL;
 579                 drive->failed_pc = NULL;
 580         }
 581         drive->pc_callback(drive, 0);
 582         return ide_stopped;
 583 }
 584
 585 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
 586                                    struct ide_atapi_pc *pc, struct request *rq,
 587                                    u8 opcode)
 588 {
 589         unsigned int length = rq->nr_sectors;
 590
 591         ide_init_pc(pc);
 592         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
 593         pc->c[1] = 1;
 594         pc->bh = NULL;
 595         pc->buf = NULL;
 596         pc->buf_size = length * tape->blk_size;
 597         pc->req_xfer = pc->buf_size;
 598         if (pc->req_xfer == tape->buffer_size)
 599                 pc->flags |= PC_FLAG_DMA_OK;
 600
 601         if (opcode == READ_6)
 602                 pc->c[0] = READ_6;
 603         else if (opcode == WRITE_6) {
 604                 pc->c[0] = WRITE_6;
 605                 pc->flags |= PC_FLAG_WRITING;
 606         }
 607
 608         memcpy(rq->cmd, pc->c, 12);
 609 }
 610
 611 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 612                                           struct request *rq, sector_t block)
 613 {
 614         ide_hwif_t *hwif = drive->hwif;
 615         idetape_tape_t *tape = drive->driver_data;
 616         struct ide_atapi_pc *pc = NULL;
 617         struct request *postponed_rq = tape->postponed_rq;
 618         struct ide_cmd cmd;
 619         u8 stat;
 620
 621         debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %lu\n"
 622                   (unsigned long long)rq->sector, rq->nr_sectors);
 623
 624         if (!(blk_special_request(rq) || blk_sense_request(rq))) {
 625                 /* We do not support buffer cache originated requests. */
 626                 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
 627                         "request queue (%d)\n", drive->name, rq->cmd_type);
 628                 if (blk_fs_request(rq) == 0 && rq->errors == 0)
 629                         rq->errors = -EIO;
 630                 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
 631                 return ide_stopped;
 632         }
 633
 634         /* Retry a failed packet command */
 635         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 636                 pc = drive->failed_pc;
 637                 goto out;
 638         }
 639
 640         if (postponed_rq != NULL)
 641                 if (rq != postponed_rq) {
 642                         printk(KERN_ERR "ide-tape: ide-tape.c bug - "
 643                                         "Two DSC requests were queued\n");
 644                         drive->failed_pc = NULL;
 645                         rq->errors = 0;
 646                         ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 647                         return ide_stopped;
 648                 }
 649
 650         tape->postponed_rq = NULL;
 651
 652         /*
 653          * If the tape is still busy, postpone our request and service
 654          * the other device meanwhile.
 655          */
 656         stat = hwif->tp_ops->read_status(hwif);
 657
 658         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 659             (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
 660                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 661
 662         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 663                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 664                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 665         }
 666
 667         if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) &&
 668             (stat & ATA_DSC) == 0) {
 669                 if (postponed_rq == NULL) {
 670                         tape->dsc_polling_start = jiffies;
 671                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 672                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 673                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 674                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 675                                 tape->name);
 676                         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 677                                 idetape_media_access_finished(drive);
 678                                 return ide_stopped;
 679                         } else {
 680                                 return ide_do_reset(drive);
 681                         }
 682                 } else if (time_after(jiffies,
 683                                         tape->dsc_polling_start +
 684                                         IDETAPE_DSC_MA_THRESHOLD))
 685                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 686                 idetape_postpone_request(drive);
 687                 return ide_stopped;
 688         }
 689         if (rq->cmd[13] & REQ_IDETAPE_READ) {
 690                 pc = &tape->queued_pc;
 691                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 692                 goto out;
 693         }
 694         if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
 695                 pc = &tape->queued_pc;
 696                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 697                 goto out;
 698         }
 699         if (rq->cmd[13] & REQ_IDETAPE_PC1) {
 700                 pc = (struct ide_atapi_pc *)rq->special;
 701                 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
 702                 rq->cmd[13] |= REQ_IDETAPE_PC2;
 703                 goto out;
 704         }
 705         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 706                 idetape_media_access_finished(drive);
 707                 return ide_stopped;
 708         }
 709         BUG();
 710
 711 out:
 712         /* prepare sense request for this command */
 713         ide_prep_sense(drive, rq);
 714
 715         memset(&cmd, 0, sizeof(cmd));
 716
 717         if (rq_data_dir(rq))
 718                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 719
 720         cmd.rq = rq;
 721
 722         ide_init_sg_cmd(&cmd, pc->req_xfer);
 723         ide_map_sg(drive, &cmd);
 724
 725         return ide_tape_issue_pc(drive, &cmd, pc);
 726 }
 727
 728 /*
 729  * Write a filemark if write_filemark=1. Flush the device buffers without
 730  * writing a filemark otherwise.
 731  */
 732 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 733                 struct ide_atapi_pc *pc, int write_filemark)
 734 {
 735         ide_init_pc(pc);
 736         pc->c[0] = WRITE_FILEMARKS;
 737         pc->c[4] = write_filemark;
 738         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 739 }
 740
 741 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 742 {
 743         idetape_tape_t *tape = drive->driver_data;
 744         struct gendisk *disk = tape->disk;
 745         int load_attempted = 0;
 746
 747         /* Wait for the tape to become ready */
 748         set_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
 749         timeout += jiffies;
 750         while (time_before(jiffies, timeout)) {
 751                 if (ide_do_test_unit_ready(drive, disk) == 0)
 752                         return 0;
 753                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 754                     || (tape->asc == 0x3A)) {
 755                         /* no media */
 756                         if (load_attempted)
 757                                 return -ENOMEDIUM;
 758                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 759                         load_attempted = 1;
 760                 /* not about to be ready */
 761                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 762                              (tape->ascq == 1 || tape->ascq == 8)))
 763                         return -EIO;
 764                 msleep(100);
 765         }
 766         return -EIO;
 767 }
 768
 769 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 770 {
 771         struct ide_tape_obj *tape = drive->driver_data;
 772         struct ide_atapi_pc pc;
 773         int rc;
 774
 775         idetape_create_write_filemark_cmd(drive, &pc, 0);
 776         rc = ide_queue_pc_tail(drive, tape->disk, &pc);
 777         if (rc)
 778                 return rc;
 779         idetape_wait_ready(drive, 60 * 5 * HZ);
 780         return 0;
 781 }
 782
 783 static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc)
 784 {
 785         ide_init_pc(pc);
 786         pc->c[0] = READ_POSITION;
 787         pc->req_xfer = 20;
 788 }
 789
 790 static int idetape_read_position(ide_drive_t *drive)
 791 {
 792         idetape_tape_t *tape = drive->driver_data;
 793         struct ide_atapi_pc pc;
 794         int position;
 795
 796         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 797
 798         idetape_create_read_position_cmd(&pc);
 799         if (ide_queue_pc_tail(drive, tape->disk, &pc))
 800                 return -1;
 801         position = tape->first_frame;
 802         return position;
 803 }
 804
 805 static void idetape_create_locate_cmd(ide_drive_t *drive,
 806                 struct ide_atapi_pc *pc,
 807                 unsigned int block, u8 partition, int skip)
 808 {
 809         ide_init_pc(pc);
 810         pc->c[0] = POSITION_TO_ELEMENT;
 811         pc->c[1] = 2;
 812         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 813         pc->c[8] = partition;
 814         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 815 }
 816
 817 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 818 {
 819         idetape_tape_t *tape = drive->driver_data;
 820
 821         if (tape->chrdev_dir != IDETAPE_DIR_READ)
 822                 return;
 823
 824         clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags);
 825         tape->valid = 0;
 826         if (tape->buf != NULL) {
 827                 kfree(tape->buf);
 828                 tape->buf = NULL;
 829         }
 830
 831         tape->chrdev_dir = IDETAPE_DIR_NONE;
 832 }
 833
 834 /*
 835  * Position the tape to the requested block using the LOCATE packet command.
 836  * A READ POSITION command is then issued to check where we are positioned. Like
 837  * all higher level operations, we queue the commands at the tail of the request
 838  * queue and wait for their completion.
 839  */
 840 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 841                 u8 partition, int skip)
 842 {
 843         idetape_tape_t *tape = drive->driver_data;
 844         struct gendisk *disk = tape->disk;
 845         int retval;
 846         struct ide_atapi_pc pc;
 847
 848         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 849                 __ide_tape_discard_merge_buffer(drive);
 850         idetape_wait_ready(drive, 60 * 5 * HZ);
 851         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 852         retval = ide_queue_pc_tail(drive, disk, &pc);
 853         if (retval)
 854                 return (retval);
 855
 856         idetape_create_read_position_cmd(&pc);
 857         return ide_queue_pc_tail(drive, disk, &pc);
 858 }
 859
 860 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 861                                           int restore_position)
 862 {
 863         idetape_tape_t *tape = drive->driver_data;
 864         int seek, position;
 865
 866         __ide_tape_discard_merge_buffer(drive);
 867         if (restore_position) {
 868                 position = idetape_read_position(drive);
 869                 seek = position > 0 ? position : 0;
 870                 if (idetape_position_tape(drive, seek, 0, 0)) {
 871                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 872                                          " %s\n", tape->name, __func__);
 873                         return;
 874                 }
 875         }
 876 }
 877
 878 /*
 879  * Generate a read/write request for the block device interface and wait for it
 880  * to be serviced.
 881  */
 882 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 883 {
 884         idetape_tape_t *tape = drive->driver_data;
 885         struct request *rq;
 886         int ret;
 887
 888         debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
 889         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 890         BUG_ON(size < 0 || size % tape->blk_size);
 891
 892         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
 893         rq->cmd_type = REQ_TYPE_SPECIAL;
 894         rq->cmd[13] = cmd;
 895         rq->rq_disk = tape->disk;
 896         rq->sector = tape->first_frame;
 897
 898         if (size) {
 899                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 900                                       __GFP_WAIT);
 901                 if (ret)
 902                         goto out_put;
 903         }
 904
 905         blk_execute_rq(drive->queue, tape->disk, rq, 0);
 906
 907         /* calculate the number of transferred bytes and update buffer state */
 908         size -= rq->data_len;
 909         tape->cur = tape->buf;
 910         if (cmd == REQ_IDETAPE_READ)
 911                 tape->valid = size;
 912         else
 913                 tape->valid = 0;
 914
 915         ret = size;
 916         if (rq->errors == IDE_DRV_ERROR_GENERAL)
 917                 ret = -EIO;
 918 out_put:
 919         blk_put_request(rq);
 920         return ret;
 921 }
 922
 923 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 924 {
 925         ide_init_pc(pc);
 926         pc->c[0] = INQUIRY;
 927         pc->c[4] = 254;
 928         pc->req_xfer = 254;
 929 }
 930
 931 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 932                 struct ide_atapi_pc *pc)
 933 {
 934         ide_init_pc(pc);
 935         pc->c[0] = REZERO_UNIT;
 936         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 937 }
 938
 939 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 940 {
 941         ide_init_pc(pc);
 942         pc->c[0] = ERASE;
 943         pc->c[1] = 1;
 944         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 945 }
 946
 947 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 948 {
 949         ide_init_pc(pc);
 950         pc->c[0] = SPACE;
 951         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 952         pc->c[1] = cmd;
 953         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 954 }
 955
 956 /* Queue up a character device originated write request. */
 957 static int idetape_add_chrdev_write_request(ide_drive_t *drive, int size)
 958 {
 959         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
 960
 961         return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, size);
 962 }
 963
 964 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 965 {
 966         idetape_tape_t *tape = drive->driver_data;
 967
 968         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 969                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 970                                 " but we are not writing.\n");
 971                 return;
 972         }
 973         if (tape->buf) {
 974                 size_t aligned = roundup(tape->valid, tape->blk_size);
 975
 976                 memset(tape->cur, 0, aligned - tape->valid);
 977                 idetape_add_chrdev_write_request(drive, aligned);
 978                 kfree(tape->buf);
 979                 tape->buf = NULL;
 980         }
 981         tape->chrdev_dir = IDETAPE_DIR_NONE;
 982 }
 983
 984 static int idetape_init_rw(ide_drive_t *drive, int dir)
 985 {
 986         idetape_tape_t *tape = drive->driver_data;
 987         int rc;
 988
 989         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 990
 991         if (tape->chrdev_dir == dir)
 992                 return 0;
 993
 994         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 995                 ide_tape_discard_merge_buffer(drive, 1);
 996         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 997                 ide_tape_flush_merge_buffer(drive);
 998                 idetape_flush_tape_buffers(drive);
 999         }
1000
1001         if (tape->buf || tape->valid) {
1002                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
1003                 tape->valid = 0;
1004         }
1005
1006         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1007         if (!tape->buf)
1008                 return -ENOMEM;
1009         tape->chrdev_dir = dir;
1010         tape->cur = tape->buf;
1011
1012         /*
1013          * Issue a 0 rw command to ensure that DSC handshake is
1014          * switched from completion mode to buffer available mode.  No
1015          * point in issuing this if DSC overlap isn't supported, some
1016          * drives (Seagate STT3401A) will return an error.
1017          */
1018         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1019                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
1020                                                   : REQ_IDETAPE_WRITE;
1021
1022                 rc = idetape_queue_rw_tail(drive, cmd, 0);
1023                 if (rc < 0) {
1024                         kfree(tape->buf);
1025                         tape->buf = NULL;
1026                         tape->chrdev_dir = IDETAPE_DIR_NONE;
1027                         return rc;
1028                 }
1029         }
1030
1031         return 0;
1032 }
1033
1034 /* called from idetape_chrdev_read() to service a chrdev read request. */
1035 static int idetape_add_chrdev_read_request(ide_drive_t *drive, int size)
1036 {
1037         debug_log(DBG_PROCS, "Enter %s, %d bytes\n", __func__, size);
1038
1039         /* If we are at a filemark, return a read length of 0 */
1040         if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1041                 return 0;
1042
1043         idetape_init_rw(drive, IDETAPE_DIR_READ);
1044
1045         return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, size);
1046 }
1047
1048 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
1049 {
1050         idetape_tape_t *tape = drive->driver_data;
1051
1052         memset(tape->buf, 0, tape->buffer_size);
1053
1054         while (bcount) {
1055                 unsigned int count = min(tape->buffer_size, bcount);
1056
1057                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1058                 bcount -= count;
1059         }
1060 }
1061
1062 /*
1063  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1064  * currently support only one partition.
1065  */
1066 static int idetape_rewind_tape(ide_drive_t *drive)
1067 {
1068         struct ide_tape_obj *tape = drive->driver_data;
1069         struct gendisk *disk = tape->disk;
1070         int retval;
1071         struct ide_atapi_pc pc;
1072
1073         debug_log(DBG_SENSE, "Enter %s\n", __func__);
1074
1075         idetape_create_rewind_cmd(drive, &pc);
1076         retval = ide_queue_pc_tail(drive, disk, &pc);
1077         if (retval)
1078                 return retval;
1079
1080         idetape_create_read_position_cmd(&pc);
1081         retval = ide_queue_pc_tail(drive, disk, &pc);
1082         if (retval)
1083                 return retval;
1084         return 0;
1085 }
1086
1087 /* mtio.h compatible commands should be issued to the chrdev interface. */
1088 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1089                                 unsigned long arg)
1090 {
1091         idetape_tape_t *tape = drive->driver_data;
1092         void __user *argp = (void __user *)arg;
1093
1094         struct idetape_config {
1095                 int dsc_rw_frequency;
1096                 int dsc_media_access_frequency;
1097                 int nr_stages;
1098         } config;
1099
1100         debug_log(DBG_PROCS, "Enter %s\n", __func__);
1101
1102         switch (cmd) {
1103         case 0x0340:
1104                 if (copy_from_user(&config, argp, sizeof(config)))
1105                         return -EFAULT;
1106                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1107                 break;
1108         case 0x0350:
1109                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1110                 config.nr_stages = 1;
1111                 if (copy_to_user(argp, &config, sizeof(config)))
1112                         return -EFAULT;
1113                 break;
1114         default:
1115                 return -EIO;
1116         }
1117         return 0;
1118 }
1119
1120 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1121                                         int mt_count)
1122 {
1123         idetape_tape_t *tape = drive->driver_data;
1124         struct gendisk *disk = tape->disk;
1125         struct ide_atapi_pc pc;
1126         int retval, count = 0;
1127         int sprev = !!(tape->caps[4] & 0x20);
1128
1129         if (mt_count == 0)
1130                 return 0;
1131         if (MTBSF == mt_op || MTBSFM == mt_op) {
1132                 if (!sprev)
1133                         return -EIO;
1134                 mt_count = -mt_count;
1135         }
1136
1137         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1138                 tape->valid = 0;
1139                 if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1140                         ++count;
1141                 ide_tape_discard_merge_buffer(drive, 0);
1142         }
1143
1144         switch (mt_op) {
1145         case MTFSF:
1146         case MTBSF:
1147                 idetape_create_space_cmd(&pc, mt_count - count,
1148                                          IDETAPE_SPACE_OVER_FILEMARK);
1149                 return ide_queue_pc_tail(drive, disk, &pc);
1150         case MTFSFM:
1151         case MTBSFM:
1152                 if (!sprev)
1153                         return -EIO;
1154                 retval = idetape_space_over_filemarks(drive, MTFSF,
1155                                                       mt_count - count);
1156                 if (retval)
1157                         return retval;
1158                 count = (MTBSFM == mt_op ? 1 : -1);
1159                 return idetape_space_over_filemarks(drive, MTFSF, count);
1160         default:
1161                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1162                                 mt_op);
1163                 return -EIO;
1164         }
1165 }
1166
1167 /*
1168  * Our character device read / write functions.
1169  *
1170  * The tape is optimized to maximize throughput when it is transferring an
1171  * integral number of the "continuous transfer limit", which is a parameter of
1172  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1173  *
1174  * As of version 1.3 of the driver, the character device provides an abstract
1175  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1176  * same backup/restore procedure is supported. The driver will internally
1177  * convert the requests to the recommended transfer unit, so that an unmatch
1178  * between the user's block size to the recommended size will only result in a
1179  * (slightly) increased driver overhead, but will no longer hit performance.
1180  * This is not applicable to Onstream.
1181  */
1182 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1183                                    size_t count, loff_t *ppos)
1184 {
1185         struct ide_tape_obj *tape = file->private_data;
1186         ide_drive_t *drive = tape->drive;
1187         ssize_t bytes_read, temp, actually_read = 0, rc;
1188         ssize_t ret = 0;
1189
1190         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1191
1192         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1193                 if (test_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags))
1194                         if (count > tape->blk_size &&
1195                             (count % tape->blk_size) == 0)
1196                                 tape->user_bs_factor = count / tape->blk_size;
1197         }
1198         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1199         if (rc < 0)
1200                 return rc;
1201         if (count == 0)
1202                 return (0);
1203         if (tape->valid) {
1204                 actually_read = min_t(unsigned int, tape->valid, count);
1205                 if (copy_to_user(buf, tape->cur, actually_read))
1206                         ret = -EFAULT;
1207                 buf += actually_read;
1208                 count -= actually_read;
1209                 tape->cur += actually_read;
1210                 tape->valid -= actually_read;
1211         }
1212         while (count >= tape->buffer_size) {
1213                 bytes_read = idetape_add_chrdev_read_request(drive,
1214                                                              tape->buffer_size);
1215                 if (bytes_read <= 0)
1216                         goto finish;
1217                 if (copy_to_user(buf, tape->cur, bytes_read))
1218                         ret = -EFAULT;
1219                 buf += bytes_read;
1220                 count -= bytes_read;
1221                 actually_read += bytes_read;
1222         }
1223         if (count) {
1224                 bytes_read = idetape_add_chrdev_read_request(drive,
1225                                                              tape->buffer_size);
1226                 if (bytes_read <= 0)
1227                         goto finish;
1228                 temp = min((unsigned long)count, (unsigned long)bytes_read);
1229                 if (copy_to_user(buf, tape->cur, temp))
1230                         ret = -EFAULT;
1231                 actually_read += temp;
1232                 tape->cur += temp;
1233                 tape->valid -= temp;
1234         }
1235 finish:
1236         if (!actually_read && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) {
1237                 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
1238
1239                 idetape_space_over_filemarks(drive, MTFSF, 1);
1240                 return 0;
1241         }
1242
1243         return ret ? ret : actually_read;
1244 }
1245
1246 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1247                                      size_t count, loff_t *ppos)
1248 {
1249         struct ide_tape_obj *tape = file->private_data;
1250         ide_drive_t *drive = tape->drive;
1251         ssize_t actually_written = 0;
1252         ssize_t ret = 0;
1253         int rc;
1254
1255         /* The drive is write protected. */
1256         if (tape->write_prot)
1257                 return -EACCES;
1258
1259         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1260
1261         /* Initialize write operation */
1262         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1263         if (rc < 0)
1264                 return rc;
1265         if (count == 0)
1266                 return (0);
1267         if (tape->valid < tape->buffer_size) {
1268                 actually_written = min_t(unsigned int,
1269                                          tape->buffer_size - tape->valid,
1270                                          count);
1271                 if (copy_from_user(tape->cur, buf, actually_written))
1272                         ret = -EFAULT;
1273                 buf += actually_written;
1274                 count -= actually_written;
1275                 tape->cur += actually_written;
1276                 tape->valid += actually_written;
1277
1278                 if (tape->valid == tape->buffer_size) {
1279                         ssize_t retval;
1280                         retval = idetape_add_chrdev_write_request(drive,
1281                                                         tape->buffer_size);
1282                         if (retval <= 0)
1283                                 return (retval);
1284                 }
1285         }
1286         while (count >= tape->buffer_size) {
1287                 ssize_t retval;
1288                 if (copy_from_user(tape->cur, buf, tape->buffer_size))
1289                         ret = -EFAULT;
1290                 buf += tape->buffer_size;
1291                 count -= tape->buffer_size;
1292                 retval = idetape_add_chrdev_write_request(drive,
1293                                                           tape->buffer_size);
1294                 actually_written += tape->buffer_size;
1295                 if (retval <= 0)
1296                         return (retval);
1297         }
1298         if (count) {
1299                 actually_written += count;
1300                 if (copy_from_user(tape->cur, buf, count))
1301                         ret = -EFAULT;
1302                 tape->cur += count;
1303                 tape->valid += count;
1304         }
1305         return ret ? ret : actually_written;
1306 }
1307
1308 static int idetape_write_filemark(ide_drive_t *drive)
1309 {
1310         struct ide_tape_obj *tape = drive->driver_data;
1311         struct ide_atapi_pc pc;
1312
1313         /* Write a filemark */
1314         idetape_create_write_filemark_cmd(drive, &pc, 1);
1315         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1316                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1317                 return -EIO;
1318         }
1319         return 0;
1320 }
1321
1322 /*
1323  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1324  * requested.
1325  *
1326  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1327  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1328  * usually not supported.
1329  *
1330  * The following commands are currently not supported:
1331  *
1332  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1333  * MT_ST_WRITE_THRESHOLD.
1334  */
1335 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1336 {
1337         idetape_tape_t *tape = drive->driver_data;
1338         struct gendisk *disk = tape->disk;
1339         struct ide_atapi_pc pc;
1340         int i, retval;
1341
1342         debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
1343                         mt_op, mt_count);
1344
1345         switch (mt_op) {
1346         case MTFSF:
1347         case MTFSFM:
1348         case MTBSF:
1349         case MTBSFM:
1350                 if (!mt_count)
1351                         return 0;
1352                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1353         default:
1354                 break;
1355         }
1356
1357         switch (mt_op) {
1358         case MTWEOF:
1359                 if (tape->write_prot)
1360                         return -EACCES;
1361                 ide_tape_discard_merge_buffer(drive, 1);
1362                 for (i = 0; i < mt_count; i++) {
1363                         retval = idetape_write_filemark(drive);
1364                         if (retval)
1365                                 return retval;
1366                 }
1367                 return 0;
1368         case MTREW:
1369                 ide_tape_discard_merge_buffer(drive, 0);
1370                 if (idetape_rewind_tape(drive))
1371                         return -EIO;
1372                 return 0;
1373         case MTLOAD:
1374                 ide_tape_discard_merge_buffer(drive, 0);
1375                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1376         case MTUNLOAD:
1377         case MTOFFL:
1378                 /*
1379                  * If door is locked, attempt to unlock before
1380                  * attempting to eject.
1381                  */
1382                 if (tape->door_locked) {
1383                         if (!ide_set_media_lock(drive, disk, 0))
1384                                 tape->door_locked = DOOR_UNLOCKED;
1385                 }
1386                 ide_tape_discard_merge_buffer(drive, 0);
1387                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1388                 if (!retval)
1389                         clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1390                 return retval;
1391         case MTNOP:
1392                 ide_tape_discard_merge_buffer(drive, 0);
1393                 return idetape_flush_tape_buffers(drive);
1394         case MTRETEN:
1395                 ide_tape_discard_merge_buffer(drive, 0);
1396                 return ide_do_start_stop(drive, disk,
1397                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1398         case MTEOM:
1399                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1400                 return ide_queue_pc_tail(drive, disk, &pc);
1401         case MTERASE:
1402                 (void)idetape_rewind_tape(drive);
1403                 idetape_create_erase_cmd(&pc);
1404                 return ide_queue_pc_tail(drive, disk, &pc);
1405         case MTSETBLK:
1406                 if (mt_count) {
1407                         if (mt_count < tape->blk_size ||
1408                             mt_count % tape->blk_size)
1409                                 return -EIO;
1410                         tape->user_bs_factor = mt_count / tape->blk_size;
1411                         clear_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1412                 } else
1413                         set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1414                 return 0;
1415         case MTSEEK:
1416                 ide_tape_discard_merge_buffer(drive, 0);
1417                 return idetape_position_tape(drive,
1418                         mt_count * tape->user_bs_factor, tape->partition, 0);
1419         case MTSETPART:
1420                 ide_tape_discard_merge_buffer(drive, 0);
1421                 return idetape_position_tape(drive, 0, mt_count, 0);
1422         case MTFSR:
1423         case MTBSR:
1424         case MTLOCK:
1425                 retval = ide_set_media_lock(drive, disk, 1);
1426                 if (retval)
1427                         return retval;
1428                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1429                 return 0;
1430         case MTUNLOCK:
1431                 retval = ide_set_media_lock(drive, disk, 0);
1432                 if (retval)
1433                         return retval;
1434                 tape->door_locked = DOOR_UNLOCKED;
1435                 return 0;
1436         default:
1437                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1438                                 mt_op);
1439                 return -EIO;
1440         }
1441 }
1442
1443 /*
1444  * Our character device ioctls. General mtio.h magnetic io commands are
1445  * supported here, and not in the corresponding block interface. Our own
1446  * ide-tape ioctls are supported on both interfaces.
1447  */
1448 static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
1449                                 unsigned int cmd, unsigned long arg)
1450 {
1451         struct ide_tape_obj *tape = file->private_data;
1452         ide_drive_t *drive = tape->drive;
1453         struct mtop mtop;
1454         struct mtget mtget;
1455         struct mtpos mtpos;
1456         int block_offset = 0, position = tape->first_frame;
1457         void __user *argp = (void __user *)arg;
1458
1459         debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
1460
1461         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1462                 ide_tape_flush_merge_buffer(drive);
1463                 idetape_flush_tape_buffers(drive);
1464         }
1465         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1466                 block_offset = tape->valid /
1467                         (tape->blk_size * tape->user_bs_factor);
1468                 position = idetape_read_position(drive);
1469                 if (position < 0)
1470                         return -EIO;
1471         }
1472         switch (cmd) {
1473         case MTIOCTOP:
1474                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1475                         return -EFAULT;
1476                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1477         case MTIOCGET:
1478                 memset(&mtget, 0, sizeof(struct mtget));
1479                 mtget.mt_type = MT_ISSCSI2;
1480                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1481                 mtget.mt_dsreg =
1482                         ((tape->blk_size * tape->user_bs_factor)
1483                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1484
1485                 if (tape->drv_write_prot)
1486                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1487
1488                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1489                         return -EFAULT;
1490                 return 0;
1491         case MTIOCPOS:
1492                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1493                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1494                         return -EFAULT;
1495                 return 0;
1496         default:
1497                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1498                         ide_tape_discard_merge_buffer(drive, 1);
1499                 return idetape_blkdev_ioctl(drive, cmd, arg);
1500         }
1501 }
1502
1503 /*
1504  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1505  * block size with the reported value.
1506  */
1507 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1508 {
1509         idetape_tape_t *tape = drive->driver_data;
1510         struct ide_atapi_pc pc;
1511
1512         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1513         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1514                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1515                 if (tape->blk_size == 0) {
1516                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1517                                             "block size, assuming 32k\n");
1518                         tape->blk_size = 32768;
1519                 }
1520                 return;
1521         }
1522         tape->blk_size = (pc.buf[4 + 5] << 16) +
1523                                 (pc.buf[4 + 6] << 8)  +
1524                                  pc.buf[4 + 7];
1525         tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7;
1526 }
1527
1528 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1529 {
1530         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1531         ide_drive_t *drive;
1532         idetape_tape_t *tape;
1533         int retval;
1534
1535         if (i >= MAX_HWIFS * MAX_DRIVES)
1536                 return -ENXIO;
1537
1538         lock_kernel();
1539         tape = ide_tape_chrdev_get(i);
1540         if (!tape) {
1541                 unlock_kernel();
1542                 return -ENXIO;
1543         }
1544
1545         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1546
1547         /*
1548          * We really want to do nonseekable_open(inode, filp); here, but some
1549          * versions of tar incorrectly call lseek on tapes and bail out if that
1550          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1551          */
1552         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1553
1554         drive = tape->drive;
1555
1556         filp->private_data = tape;
1557
1558         if (test_and_set_bit(IDE_AFLAG_BUSY, &drive->atapi_flags)) {
1559                 retval = -EBUSY;
1560                 goto out_put_tape;
1561         }
1562
1563         retval = idetape_wait_ready(drive, 60 * HZ);
1564         if (retval) {
1565                 clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1566                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1567                 goto out_put_tape;
1568         }
1569
1570         idetape_read_position(drive);
1571         if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags))
1572                 (void)idetape_rewind_tape(drive);
1573
1574         /* Read block size and write protect status from drive. */
1575         ide_tape_get_bsize_from_bdesc(drive);
1576
1577         /* Set write protect flag if device is opened as read-only. */
1578         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1579                 tape->write_prot = 1;
1580         else
1581                 tape->write_prot = tape->drv_write_prot;
1582
1583         /* Make sure drive isn't write protected if user wants to write. */
1584         if (tape->write_prot) {
1585                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1586                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1587                         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1588                         retval = -EROFS;
1589                         goto out_put_tape;
1590                 }
1591         }
1592
1593         /* Lock the tape drive door so user can't eject. */
1594         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1595                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1596                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1597                                 tape->door_locked = DOOR_LOCKED;
1598                 }
1599         }
1600         unlock_kernel();
1601         return 0;
1602
1603 out_put_tape:
1604         ide_tape_put(tape);
1605         unlock_kernel();
1606         return retval;
1607 }
1608
1609 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1610 {
1611         idetape_tape_t *tape = drive->driver_data;
1612
1613         ide_tape_flush_merge_buffer(drive);
1614         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1615         if (tape->buf != NULL) {
1616                 idetape_pad_zeros(drive, tape->blk_size *
1617                                 (tape->user_bs_factor - 1));
1618                 kfree(tape->buf);
1619                 tape->buf = NULL;
1620         }
1621         idetape_write_filemark(drive);
1622         idetape_flush_tape_buffers(drive);
1623         idetape_flush_tape_buffers(drive);
1624 }
1625
1626 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1627 {
1628         struct ide_tape_obj *tape = filp->private_data;
1629         ide_drive_t *drive = tape->drive;
1630         unsigned int minor = iminor(inode);
1631
1632         lock_kernel();
1633         tape = drive->driver_data;
1634
1635         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1636
1637         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1638                 idetape_write_release(drive, minor);
1639         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1640                 if (minor < 128)
1641                         ide_tape_discard_merge_buffer(drive, 1);
1642         }
1643
1644         if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags))
1645                 (void) idetape_rewind_tape(drive);
1646         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1647                 if (tape->door_locked == DOOR_LOCKED) {
1648                         if (!ide_set_media_lock(drive, tape->disk, 0))
1649                                 tape->door_locked = DOOR_UNLOCKED;
1650                 }
1651         }
1652         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1653         ide_tape_put(tape);
1654         unlock_kernel();
1655         return 0;
1656 }
1657
1658 static void idetape_get_inquiry_results(ide_drive_t *drive)
1659 {
1660         idetape_tape_t *tape = drive->driver_data;
1661         struct ide_atapi_pc pc;
1662         u8 pc_buf[256];
1663         char fw_rev[4], vendor_id[8], product_id[16];
1664
1665         idetape_create_inquiry_cmd(&pc);
1666         pc.buf = &pc_buf[0];
1667         pc.buf_size = sizeof(pc_buf);
1668
1669         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1670                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1671                                 tape->name);
1672                 return;
1673         }
1674         memcpy(vendor_id, &pc.buf[8], 8);
1675         memcpy(product_id, &pc.buf[16], 16);
1676         memcpy(fw_rev, &pc.buf[32], 4);
1677
1678         ide_fixstring(vendor_id, 8, 0);
1679         ide_fixstring(product_id, 16, 0);
1680         ide_fixstring(fw_rev, 4, 0);
1681
1682         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1683                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1684 }
1685
1686 /*
1687  * Ask the tape about its various parameters. In particular, we will adjust our
1688  * data transfer buffer size to the recommended value as returned by the tape.
1689  */
1690 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1691 {
1692         idetape_tape_t *tape = drive->driver_data;
1693         struct ide_atapi_pc pc;
1694         u8 *caps;
1695         u8 speed, max_speed;
1696
1697         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1698         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1699                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1700                                 " some default values\n");
1701                 tape->blk_size = 512;
1702                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1703                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1704                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1705                 return;
1706         }
1707         caps = pc.buf + 4 + pc.buf[3];
1708
1709         /* convert to host order and save for later use */
1710         speed = be16_to_cpup((__be16 *)&caps[14]);
1711         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1712
1713         *(u16 *)&caps[8] = max_speed;
1714         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1715         *(u16 *)&caps[14] = speed;
1716         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1717
1718         if (!speed) {
1719                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1720                                 "(assuming 650KB/sec)\n", drive->name);
1721                 *(u16 *)&caps[14] = 650;
1722         }
1723         if (!max_speed) {
1724                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1725                                 "(assuming 650KB/sec)\n", drive->name);
1726                 *(u16 *)&caps[8] = 650;
1727         }
1728
1729         memcpy(&tape->caps, caps, 20);
1730
1731         /* device lacks locking support according to capabilities page */
1732         if ((caps[6] & 1) == 0)
1733                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1734
1735         if (caps[7] & 0x02)
1736                 tape->blk_size = 512;
1737         else if (caps[7] & 0x04)
1738                 tape->blk_size = 1024;
1739 }
1740
1741 #ifdef CONFIG_IDE_PROC_FS
1742 #define ide_tape_devset_get(name, field) \
1743 static int get_##name(ide_drive_t *drive) \
1744 { \
1745         idetape_tape_t *tape = drive->driver_data; \
1746         return tape->field; \
1747 }
1748
1749 #define ide_tape_devset_set(name, field) \
1750 static int set_##name(ide_drive_t *drive, int arg) \
1751 { \
1752         idetape_tape_t *tape = drive->driver_data; \
1753         tape->field = arg; \
1754         return 0; \
1755 }
1756
1757 #define ide_tape_devset_rw_field(_name, _field) \
1758 ide_tape_devset_get(_name, _field) \
1759 ide_tape_devset_set(_name, _field) \
1760 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1761
1762 #define ide_tape_devset_r_field(_name, _field) \
1763 ide_tape_devset_get(_name, _field) \
1764 IDE_DEVSET(_name, 0, get_##_name, NULL)
1765
1766 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1767 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1768 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1769 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1770
1771 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1772
1773 ide_tape_devset_rw_field(debug_mask, debug_mask);
1774 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1775
1776 ide_tape_devset_r_field(avg_speed, avg_speed);
1777 ide_tape_devset_r_field(speed, caps[14]);
1778 ide_tape_devset_r_field(buffer, caps[16]);
1779 ide_tape_devset_r_field(buffer_size, buffer_size);
1780
1781 static const struct ide_proc_devset idetape_settings[] = {
1782         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1783         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1784         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1785         __IDE_PROC_DEVSET(debug_mask,   0, 0xffff, NULL, NULL),
1786         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1787         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1788         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1789                                         mulf_tdsc, divf_tdsc),
1790         { NULL },
1791 };
1792 #endif
1793
1794 /*
1795  * The function below is called to:
1796  *
1797  * 1. Initialize our various state variables.
1798  * 2. Ask the tape for its capabilities.
1799  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1800  * is chosen based on the recommendation which we received in step 2.
1801  *
1802  * Note that at this point ide.c already assigned us an irq, so that we can
1803  * queue requests here and wait for their completion.
1804  */
1805 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1806 {
1807         unsigned long t;
1808         int speed;
1809         int buffer_size;
1810         u16 *ctl = (u16 *)&tape->caps[12];
1811
1812         drive->pc_callback       = ide_tape_callback;
1813
1814         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1815
1816         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1817                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1818                                  tape->name);
1819                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1820         }
1821
1822         /* Seagate Travan drives do not support DSC overlap. */
1823         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1824                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1825
1826         tape->minor = minor;
1827         tape->name[0] = 'h';
1828         tape->name[1] = 't';
1829         tape->name[2] = '0' + minor;
1830         tape->chrdev_dir = IDETAPE_DIR_NONE;
1831
1832         idetape_get_inquiry_results(drive);
1833         idetape_get_mode_sense_results(drive);
1834         ide_tape_get_bsize_from_bdesc(drive);
1835         tape->user_bs_factor = 1;
1836         tape->buffer_size = *ctl * tape->blk_size;
1837         while (tape->buffer_size > 0xffff) {
1838                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1839                 *ctl /= 2;
1840                 tape->buffer_size = *ctl * tape->blk_size;
1841         }
1842         buffer_size = tape->buffer_size;
1843
1844         /* select the "best" DSC read/write polling freq */
1845         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1846
1847         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1848
1849         /*
1850          * Ensure that the number we got makes sense; limit it within
1851          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1852          */
1853         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1854                                          IDETAPE_DSC_RW_MAX);
1855         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1856                 "%lums tDSC%s\n",
1857                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1858                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1859                 tape->buffer_size / 1024,
1860                 tape->best_dsc_rw_freq * 1000 / HZ,
1861                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1862
1863         ide_proc_register_driver(drive, tape->driver);
1864 }
1865
1866 static void ide_tape_remove(ide_drive_t *drive)
1867 {
1868         idetape_tape_t *tape = drive->driver_data;
1869
1870         ide_proc_unregister_driver(drive, tape->driver);
1871         device_del(&tape->dev);
1872         ide_unregister_region(tape->disk);
1873
1874         mutex_lock(&idetape_ref_mutex);
1875         put_device(&tape->dev);
1876         mutex_unlock(&idetape_ref_mutex);
1877 }
1878
1879 static void ide_tape_release(struct device *dev)
1880 {
1881         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1882         ide_drive_t *drive = tape->drive;
1883         struct gendisk *g = tape->disk;
1884
1885         BUG_ON(tape->valid);
1886
1887         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1888         drive->driver_data = NULL;
1889         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1890         device_destroy(idetape_sysfs_class,
1891                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1892         idetape_devs[tape->minor] = NULL;
1893         g->private_data = NULL;
1894         put_disk(g);
1895         kfree(tape);
1896 }
1897
1898 #ifdef CONFIG_IDE_PROC_FS
1899 static int proc_idetape_read_name
1900         (char *page, char **start, off_t off, int count, int *eof, void *data)
1901 {
1902         ide_drive_t     *drive = (ide_drive_t *) data;
1903         idetape_tape_t  *tape = drive->driver_data;
1904         char            *out = page;
1905         int             len;
1906
1907         len = sprintf(out, "%s\n", tape->name);
1908         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
1909 }
1910
1911 static ide_proc_entry_t idetape_proc[] = {
1912         { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
1913         { "name",       S_IFREG|S_IRUGO,        proc_idetape_read_name, NULL },
1914         { NULL, 0, NULL, NULL }
1915 };
1916
1917 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1918 {
1919         return idetape_proc;
1920 }
1921
1922 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1923 {
1924         return idetape_settings;
1925 }
1926 #endif
1927
1928 static int ide_tape_probe(ide_drive_t *);
1929
1930 static struct ide_driver idetape_driver = {
1931         .gen_driver = {
1932                 .owner          = THIS_MODULE,
1933                 .name           = "ide-tape",
1934                 .bus            = &ide_bus_type,
1935         },
1936         .probe                  = ide_tape_probe,
1937         .remove                 = ide_tape_remove,
1938         .version                = IDETAPE_VERSION,
1939         .do_request             = idetape_do_request,
1940 #ifdef CONFIG_IDE_PROC_FS
1941         .proc_entries           = ide_tape_proc_entries,
1942         .proc_devsets           = ide_tape_proc_devsets,
1943 #endif
1944 };
1945
1946 /* Our character device supporting functions, passed to register_chrdev. */
1947 static const struct file_operations idetape_fops = {
1948         .owner          = THIS_MODULE,
1949         .read           = idetape_chrdev_read,
1950         .write          = idetape_chrdev_write,
1951         .ioctl          = idetape_chrdev_ioctl,
1952         .open           = idetape_chrdev_open,
1953         .release        = idetape_chrdev_release,
1954 };
1955
1956 static int idetape_open(struct block_device *bdev, fmode_t mode)
1957 {
1958         struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk);
1959
1960         if (!tape)
1961                 return -ENXIO;
1962
1963         return 0;
1964 }
1965
1966 static int idetape_release(struct gendisk *disk, fmode_t mode)
1967 {
1968         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1969
1970         ide_tape_put(tape);
1971         return 0;
1972 }
1973
1974 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1975                         unsigned int cmd, unsigned long arg)
1976 {
1977         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1978         ide_drive_t *drive = tape->drive;
1979         int err = generic_ide_ioctl(drive, bdev, cmd, arg);
1980         if (err == -EINVAL)
1981                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1982         return err;
1983 }
1984
1985 static struct block_device_operations idetape_block_ops = {
1986         .owner          = THIS_MODULE,
1987         .open           = idetape_open,
1988         .release        = idetape_release,
1989         .locked_ioctl   = idetape_ioctl,
1990 };
1991
1992 static int ide_tape_probe(ide_drive_t *drive)
1993 {
1994         idetape_tape_t *tape;
1995         struct gendisk *g;
1996         int minor;
1997
1998         if (!strstr("ide-tape", drive->driver_req))
1999                 goto failed;
2000
2001         if (drive->media != ide_tape)
2002                 goto failed;
2003
2004         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
2005             ide_check_atapi_device(drive, DRV_NAME) == 0) {
2006                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
2007                                 " the driver\n", drive->name);
2008                 goto failed;
2009         }
2010         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
2011         if (tape == NULL) {
2012                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
2013                                 drive->name);
2014                 goto failed;
2015         }
2016
2017         g = alloc_disk(1 << PARTN_BITS);
2018         if (!g)
2019                 goto out_free_tape;
2020
2021         ide_init_disk(g, drive);
2022
2023         tape->dev.parent = &drive->gendev;
2024         tape->dev.release = ide_tape_release;
2025         dev_set_name(&tape->dev, dev_name(&drive->gendev));
2026
2027         if (device_register(&tape->dev))
2028                 goto out_free_disk;
2029
2030         tape->drive = drive;
2031         tape->driver = &idetape_driver;
2032         tape->disk = g;
2033
2034         g->private_data = &tape->driver;
2035
2036         drive->driver_data = tape;
2037
2038         mutex_lock(&idetape_ref_mutex);
2039         for (minor = 0; idetape_devs[minor]; minor++)
2040                 ;
2041         idetape_devs[minor] = tape;
2042         mutex_unlock(&idetape_ref_mutex);
2043
2044         idetape_setup(drive, tape, minor);
2045
2046         device_create(idetape_sysfs_class, &drive->gendev,
2047                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2048         device_create(idetape_sysfs_class, &drive->gendev,
2049                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2050                       "n%s", tape->name);
2051
2052         g->fops = &idetape_block_ops;
2053         ide_register_region(g);
2054
2055         return 0;
2056
2057 out_free_disk:
2058         put_disk(g);
2059 out_free_tape:
2060         kfree(tape);
2061 failed:
2062         return -ENODEV;
2063 }
2064
2065 static void __exit idetape_exit(void)
2066 {
2067         driver_unregister(&idetape_driver.gen_driver);
2068         class_destroy(idetape_sysfs_class);
2069         unregister_chrdev(IDETAPE_MAJOR, "ht");
2070 }
2071
2072 static int __init idetape_init(void)
2073 {
2074         int error = 1;
2075         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2076         if (IS_ERR(idetape_sysfs_class)) {
2077                 idetape_sysfs_class = NULL;
2078                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2079                 error = -EBUSY;
2080                 goto out;
2081         }
2082
2083         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2084                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2085                                 " interface\n");
2086                 error = -EBUSY;
2087                 goto out_free_class;
2088         }
2089
2090         error = driver_register(&idetape_driver.gen_driver);
2091         if (error)
2092                 goto out_free_driver;
2093
2094         return 0;
2095
2096 out_free_driver:
2097         driver_unregister(&idetape_driver.gen_driver);
2098 out_free_class:
2099         class_destroy(idetape_sysfs_class);
2100 out:
2101         return error;
2102 }
2103
2104 MODULE_ALIAS("ide:*m-tape*");
2105 module_init(idetape_init);
2106 module_exit(idetape_exit);
2107 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2108 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2109 MODULE_LICENSE("GPL");