drivers/ide/ide-tape.c

   1 /*
   2  * IDE ATAPI streaming tape driver.
   3  *
   4  * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
   5  * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
   6  *
   7  * This driver was constructed as a student project in the software laboratory
   8  * of the faculty of electrical engineering in the Technion - Israel's
   9  * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
  10  *
  11  * It is hereby placed under the terms of the GNU general public license.
  12  * (See linux/COPYING).
  13  *
  14  * For a historical changelog see
  15  * Documentation/ide/ChangeLog.ide-tape.1995-2002
  16  */
  17
  18 #define DRV_NAME "ide-tape"
  19
  20 #define IDETAPE_VERSION "1.20"
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/kernel.h>
  26 #include <linux/delay.h>
  27 #include <linux/timer.h>
  28 #include <linux/mm.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/major.h>
  32 #include <linux/errno.h>
  33 #include <linux/genhd.h>
  34 #include <linux/slab.h>
  35 #include <linux/pci.h>
  36 #include <linux/ide.h>
  37 #include <linux/smp_lock.h>
  38 #include <linux/completion.h>
  39 #include <linux/bitops.h>
  40 #include <linux/mutex.h>
  41 #include <scsi/scsi.h>
  42
  43 #include <asm/byteorder.h>
  44 #include <linux/irq.h>
  45 #include <linux/uaccess.h>
  46 #include <linux/io.h>
  47 #include <asm/unaligned.h>
  48 #include <linux/mtio.h>
  49
  50 enum {
  51         /* output errors only */
  52         DBG_ERR =               (1 << 0),
  53         /* output all sense key/asc */
  54         DBG_SENSE =             (1 << 1),
  55         /* info regarding all chrdev-related procedures */
  56         DBG_CHRDEV =            (1 << 2),
  57         /* all remaining procedures */
  58         DBG_PROCS =             (1 << 3),
  59 };
  60
  61 /* define to see debug info */
  62 #define IDETAPE_DEBUG_LOG               0
  63
  64 #if IDETAPE_DEBUG_LOG
  65 #define debug_log(lvl, fmt, args...)                    \
  66 {                                                       \
  67         if (tape->debug_mask & lvl)                     \
  68         printk(KERN_INFO "ide-tape: " fmt, ## args);    \
  69 }
  70 #else
  71 #define debug_log(lvl, fmt, args...) do {} while (0)
  72 #endif
  73
  74 /**************************** Tunable parameters *****************************/
  75 /*
  76  * After each failed packet command we issue a request sense command and retry
  77  * the packet command IDETAPE_MAX_PC_RETRIES times.
  78  *
  79  * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
  80  */
  81 #define IDETAPE_MAX_PC_RETRIES          3
  82
  83 /*
  84  * The following parameter is used to select the point in the internal tape fifo
  85  * in which we will start to refill the buffer. Decreasing the following
  86  * parameter will improve the system's latency and interactive response, while
  87  * using a high value might improve system throughput.
  88  */
  89 #define IDETAPE_FIFO_THRESHOLD          2
  90
  91 /*
  92  * DSC polling parameters.
  93  *
  94  * Polling for DSC (a single bit in the status register) is a very important
  95  * function in ide-tape. There are two cases in which we poll for DSC:
  96  *
  97  * 1. Before a read/write packet command, to ensure that we can transfer data
  98  * from/to the tape's data buffers, without causing an actual media access.
  99  * In case the tape is not ready yet, we take out our request from the device
 100  * request queue, so that ide.c could service requests from the other device
 101  * on the same interface in the meantime.
 102  *
 103  * 2. After the successful initialization of a "media access packet command",
 104  * which is a command that can take a long time to complete (the interval can
 105  * range from several seconds to even an hour). Again, we postpone our request
 106  * in the middle to free the bus for the other device. The polling frequency
 107  * here should be lower than the read/write frequency since those media access
 108  * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
 109  * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
 110  * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
 111  *
 112  * We also set a timeout for the timer, in case something goes wrong. The
 113  * timeout should be longer then the maximum execution time of a tape operation.
 114  */
 115
 116 /* DSC timings. */
 117 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 118 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 119 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 120 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 121 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 122 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 123 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 124
 125 /*************************** End of tunable parameters ***********************/
 126
 127 /* tape directions */
 128 enum {
 129         IDETAPE_DIR_NONE  = (1 << 0),
 130         IDETAPE_DIR_READ  = (1 << 1),
 131         IDETAPE_DIR_WRITE = (1 << 2),
 132 };
 133
 134 /* Tape door status */
 135 #define DOOR_UNLOCKED                   0
 136 #define DOOR_LOCKED                     1
 137 #define DOOR_EXPLICITLY_LOCKED          2
 138
 139 /* Some defines for the SPACE command */
 140 #define IDETAPE_SPACE_OVER_FILEMARK     1
 141 #define IDETAPE_SPACE_TO_EOD            3
 142
 143 /* Some defines for the LOAD UNLOAD command */
 144 #define IDETAPE_LU_LOAD_MASK            1
 145 #define IDETAPE_LU_RETENSION_MASK       2
 146 #define IDETAPE_LU_EOT_MASK             4
 147
 148 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
 149 #define IDETAPE_BLOCK_DESCRIPTOR        0
 150 #define IDETAPE_CAPABILITIES_PAGE       0x2a
 151
 152 /*
 153  * Most of our global data which we need to save even as we leave the driver due
 154  * to an interrupt or a timer event is stored in the struct defined below.
 155  */
 156 typedef struct ide_tape_obj {
 157         ide_drive_t             *drive;
 158         struct ide_driver       *driver;
 159         struct gendisk          *disk;
 160         struct device           dev;
 161
 162         /* used by REQ_IDETAPE_{READ,WRITE} requests */
 163         struct ide_atapi_pc queued_pc;
 164
 165         /*
 166          * DSC polling variables.
 167          *
 168          * While polling for DSC we use postponed_rq to postpone the current
 169          * request so that ide.c will be able to service pending requests on the
 170          * other device. Note that at most we will have only one DSC (usually
 171          * data transfer) request in the device request queue.
 172          */
 173         struct request *postponed_rq;
 174         /* The time in which we started polling for DSC */
 175         unsigned long dsc_polling_start;
 176         /* Timer used to poll for dsc */
 177         struct timer_list dsc_timer;
 178         /* Read/Write dsc polling frequency */
 179         unsigned long best_dsc_rw_freq;
 180         unsigned long dsc_poll_freq;
 181         unsigned long dsc_timeout;
 182
 183         /* Read position information */
 184         u8 partition;
 185         /* Current block */
 186         unsigned int first_frame;
 187
 188         /* Last error information */
 189         u8 sense_key, asc, ascq;
 190
 191         /* Character device operation */
 192         unsigned int minor;
 193         /* device name */
 194         char name[4];
 195         /* Current character device data transfer direction */
 196         u8 chrdev_dir;
 197
 198         /* tape block size, usually 512 or 1024 bytes */
 199         unsigned short blk_size;
 200         int user_bs_factor;
 201
 202         /* Copy of the tape's Capabilities and Mechanical Page */
 203         u8 caps[20];
 204
 205         /*
 206          * Active data transfer request parameters.
 207          *
 208          * At most, there is only one ide-tape originated data transfer request
 209          * in the device request queue. This allows ide.c to easily service
 210          * requests from the other device when we postpone our active request.
 211          */
 212
 213         /* Data buffer size chosen based on the tape's recommendation */
 214         int buffer_size;
 215         /* Staging buffer of buffer_size bytes */
 216         void *buf;
 217         /* The read/write cursor */
 218         void *cur;
 219         /* The number of valid bytes in buf */
 220         size_t valid;
 221
 222         /* Measures average tape speed */
 223         unsigned long avg_time;
 224         int avg_size;
 225         int avg_speed;
 226
 227         /* the door is currently locked */
 228         int door_locked;
 229         /* the tape hardware is write protected */
 230         char drv_write_prot;
 231         /* the tape is write protected (hardware or opened as read-only) */
 232         char write_prot;
 233
 234         u32 debug_mask;
 235 } idetape_tape_t;
 236
 237 static DEFINE_MUTEX(idetape_ref_mutex);
 238
 239 static struct class *idetape_sysfs_class;
 240
 241 static void ide_tape_release(struct device *);
 242
 243 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
 244 {
 245         struct ide_tape_obj *tape = NULL;
 246
 247         mutex_lock(&idetape_ref_mutex);
 248         tape = ide_drv_g(disk, ide_tape_obj);
 249         if (tape) {
 250                 if (ide_device_get(tape->drive))
 251                         tape = NULL;
 252                 else
 253                         get_device(&tape->dev);
 254         }
 255         mutex_unlock(&idetape_ref_mutex);
 256         return tape;
 257 }
 258
 259 static void ide_tape_put(struct ide_tape_obj *tape)
 260 {
 261         ide_drive_t *drive = tape->drive;
 262
 263         mutex_lock(&idetape_ref_mutex);
 264         put_device(&tape->dev);
 265         ide_device_put(drive);
 266         mutex_unlock(&idetape_ref_mutex);
 267 }
 268
 269 /*
 270  * The variables below are used for the character device interface. Additional
 271  * state variables are defined in our ide_drive_t structure.
 272  */
 273 static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
 274
 275 static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
 276 {
 277         struct ide_tape_obj *tape = NULL;
 278
 279         mutex_lock(&idetape_ref_mutex);
 280         tape = idetape_devs[i];
 281         if (tape)
 282                 get_device(&tape->dev);
 283         mutex_unlock(&idetape_ref_mutex);
 284         return tape;
 285 }
 286
 287 /*
 288  * called on each failed packet command retry to analyze the request sense. We
 289  * currently do not utilize this information.
 290  */
 291 static void idetape_analyze_error(ide_drive_t *drive, 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 blocks)
 883 {
 884         idetape_tape_t *tape = drive->driver_data;
 885         size_t size = blocks * tape->blk_size;
 886         struct request *rq;
 887         int ret;
 888
 889         debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
 890         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 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 blocks)
 958 {
 959         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
 960
 961         return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks);
 962 }
 963
 964 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 965 {
 966         idetape_tape_t *tape = drive->driver_data;
 967         int blocks;
 968
 969         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 970                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 971                                 " but we are not writing.\n");
 972                 return;
 973         }
 974         if (tape->buf) {
 975                 blocks = tape->valid / tape->blk_size;
 976                 if (tape->valid % tape->blk_size) {
 977                         blocks++;
 978                         memset(tape->buf + tape->valid, 0,
 979                                tape->blk_size - tape->valid % tape->blk_size);
 980                 }
 981                 (void) idetape_add_chrdev_write_request(drive, blocks);
 982         }
 983         if (tape->buf != NULL) {
 984                 kfree(tape->buf);
 985                 tape->buf = NULL;
 986         }
 987         tape->chrdev_dir = IDETAPE_DIR_NONE;
 988 }
 989
 990 static int idetape_init_read(ide_drive_t *drive)
 991 {
 992         idetape_tape_t *tape = drive->driver_data;
 993         int bytes_read;
 994
 995         /* Initialize read operation */
 996         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
 997                 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 998                         ide_tape_flush_merge_buffer(drive);
 999                         idetape_flush_tape_buffers(drive);
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                 tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1006                 if (!tape->buf)
1007                         return -ENOMEM;
1008                 tape->chrdev_dir = IDETAPE_DIR_READ;
1009                 tape->cur = tape->buf;
1010
1011                 /*
1012                  * Issue a read 0 command to ensure that DSC handshake is
1013                  * switched from completion mode to buffer available mode.
1014                  * No point in issuing this if DSC overlap isn't supported, some
1015                  * drives (Seagate STT3401A) will return an error.
1016                  */
1017                 if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1018                         bytes_read = idetape_queue_rw_tail(drive,
1019                                                         REQ_IDETAPE_READ, 0);
1020                         if (bytes_read < 0) {
1021                                 kfree(tape->buf);
1022                                 tape->buf = NULL;
1023                                 tape->chrdev_dir = IDETAPE_DIR_NONE;
1024                                 return bytes_read;
1025                         }
1026                 }
1027         }
1028
1029         return 0;
1030 }
1031
1032 /* called from idetape_chrdev_read() to service a chrdev read request. */
1033 static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
1034 {
1035         debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks);
1036
1037         /* If we are at a filemark, return a read length of 0 */
1038         if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1039                 return 0;
1040
1041         idetape_init_read(drive);
1042
1043         return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks);
1044 }
1045
1046 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
1047 {
1048         idetape_tape_t *tape = drive->driver_data;
1049
1050         memset(tape->buf, 0, tape->buffer_size);
1051
1052         while (bcount) {
1053                 unsigned int count = min(tape->buffer_size, bcount);
1054
1055                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1056                                       count / tape->blk_size);
1057                 bcount -= count;
1058         }
1059 }
1060
1061 /*
1062  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1063  * currently support only one partition.
1064  */
1065 static int idetape_rewind_tape(ide_drive_t *drive)
1066 {
1067         struct ide_tape_obj *tape = drive->driver_data;
1068         struct gendisk *disk = tape->disk;
1069         int retval;
1070         struct ide_atapi_pc pc;
1071
1072         debug_log(DBG_SENSE, "Enter %s\n", __func__);
1073
1074         idetape_create_rewind_cmd(drive, &pc);
1075         retval = ide_queue_pc_tail(drive, disk, &pc);
1076         if (retval)
1077                 return retval;
1078
1079         idetape_create_read_position_cmd(&pc);
1080         retval = ide_queue_pc_tail(drive, disk, &pc);
1081         if (retval)
1082                 return retval;
1083         return 0;
1084 }
1085
1086 /* mtio.h compatible commands should be issued to the chrdev interface. */
1087 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1088                                 unsigned long arg)
1089 {
1090         idetape_tape_t *tape = drive->driver_data;
1091         void __user *argp = (void __user *)arg;
1092
1093         struct idetape_config {
1094                 int dsc_rw_frequency;
1095                 int dsc_media_access_frequency;
1096                 int nr_stages;
1097         } config;
1098
1099         debug_log(DBG_PROCS, "Enter %s\n", __func__);
1100
1101         switch (cmd) {
1102         case 0x0340:
1103                 if (copy_from_user(&config, argp, sizeof(config)))
1104                         return -EFAULT;
1105                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1106                 break;
1107         case 0x0350:
1108                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1109                 config.nr_stages = 1;
1110                 if (copy_to_user(argp, &config, sizeof(config)))
1111                         return -EFAULT;
1112                 break;
1113         default:
1114                 return -EIO;
1115         }
1116         return 0;
1117 }
1118
1119 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1120                                         int mt_count)
1121 {
1122         idetape_tape_t *tape = drive->driver_data;
1123         struct gendisk *disk = tape->disk;
1124         struct ide_atapi_pc pc;
1125         int retval, count = 0;
1126         int sprev = !!(tape->caps[4] & 0x20);
1127
1128         if (mt_count == 0)
1129                 return 0;
1130         if (MTBSF == mt_op || MTBSFM == mt_op) {
1131                 if (!sprev)
1132                         return -EIO;
1133                 mt_count = -mt_count;
1134         }
1135
1136         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1137                 tape->valid = 0;
1138                 if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1139                         ++count;
1140                 ide_tape_discard_merge_buffer(drive, 0);
1141         }
1142
1143         switch (mt_op) {
1144         case MTFSF:
1145         case MTBSF:
1146                 idetape_create_space_cmd(&pc, mt_count - count,
1147                                          IDETAPE_SPACE_OVER_FILEMARK);
1148                 return ide_queue_pc_tail(drive, disk, &pc);
1149         case MTFSFM:
1150         case MTBSFM:
1151                 if (!sprev)
1152                         return -EIO;
1153                 retval = idetape_space_over_filemarks(drive, MTFSF,
1154                                                       mt_count - count);
1155                 if (retval)
1156                         return retval;
1157                 count = (MTBSFM == mt_op ? 1 : -1);
1158                 return idetape_space_over_filemarks(drive, MTFSF, count);
1159         default:
1160                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1161                                 mt_op);
1162                 return -EIO;
1163         }
1164 }
1165
1166 /*
1167  * Our character device read / write functions.
1168  *
1169  * The tape is optimized to maximize throughput when it is transferring an
1170  * integral number of the "continuous transfer limit", which is a parameter of
1171  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1172  *
1173  * As of version 1.3 of the driver, the character device provides an abstract
1174  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1175  * same backup/restore procedure is supported. The driver will internally
1176  * convert the requests to the recommended transfer unit, so that an unmatch
1177  * between the user's block size to the recommended size will only result in a
1178  * (slightly) increased driver overhead, but will no longer hit performance.
1179  * This is not applicable to Onstream.
1180  */
1181 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1182                                    size_t count, loff_t *ppos)
1183 {
1184         struct ide_tape_obj *tape = file->private_data;
1185         ide_drive_t *drive = tape->drive;
1186         ssize_t bytes_read, temp, actually_read = 0, rc;
1187         ssize_t ret = 0;
1188         u16 ctl = *(u16 *)&tape->caps[12];
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_read(drive);
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, ctl);
1214                 if (bytes_read <= 0)
1215                         goto finish;
1216                 if (copy_to_user(buf, tape->cur, bytes_read))
1217                         ret = -EFAULT;
1218                 buf += bytes_read;
1219                 count -= bytes_read;
1220                 actually_read += bytes_read;
1221         }
1222         if (count) {
1223                 bytes_read = idetape_add_chrdev_read_request(drive, ctl);
1224                 if (bytes_read <= 0)
1225                         goto finish;
1226                 temp = min((unsigned long)count, (unsigned long)bytes_read);
1227                 if (copy_to_user(buf, tape->cur, temp))
1228                         ret = -EFAULT;
1229                 actually_read += temp;
1230                 tape->cur += temp;
1231                 tape->valid -= temp;
1232         }
1233 finish:
1234         if (!actually_read && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) {
1235                 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
1236
1237                 idetape_space_over_filemarks(drive, MTFSF, 1);
1238                 return 0;
1239         }
1240
1241         return ret ? ret : actually_read;
1242 }
1243
1244 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1245                                      size_t count, loff_t *ppos)
1246 {
1247         struct ide_tape_obj *tape = file->private_data;
1248         ide_drive_t *drive = tape->drive;
1249         ssize_t actually_written = 0;
1250         ssize_t ret = 0;
1251         u16 ctl = *(u16 *)&tape->caps[12];
1252
1253         /* The drive is write protected. */
1254         if (tape->write_prot)
1255                 return -EACCES;
1256
1257         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1258
1259         /* Initialize write operation */
1260         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
1261                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1262                         ide_tape_discard_merge_buffer(drive, 1);
1263                 if (tape->buf || tape->valid) {
1264                         printk(KERN_ERR "ide-tape: valid should be 0 now\n");
1265                         tape->valid = 0;
1266                 }
1267                 tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1268                 if (!tape->buf)
1269                         return -ENOMEM;
1270                 tape->chrdev_dir = IDETAPE_DIR_WRITE;
1271                 tape->cur = tape->buf;
1272
1273                 /*
1274                  * Issue a write 0 command to ensure that DSC handshake is
1275                  * switched from completion mode to buffer available mode. No
1276                  * point in issuing this if DSC overlap isn't supported, some
1277                  * drives (Seagate STT3401A) will return an error.
1278                  */
1279                 if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1280                         ssize_t retval = idetape_queue_rw_tail(drive,
1281                                                         REQ_IDETAPE_WRITE, 0);
1282                         if (retval < 0) {
1283                                 kfree(tape->buf);
1284                                 tape->buf = NULL;
1285                                 tape->chrdev_dir = IDETAPE_DIR_NONE;
1286                                 return retval;
1287                         }
1288                 }
1289         }
1290         if (count == 0)
1291                 return (0);
1292         if (tape->valid < tape->buffer_size) {
1293                 actually_written = min_t(unsigned int,
1294                                          tape->buffer_size - tape->valid,
1295                                          count);
1296                 if (copy_from_user(tape->cur, buf, actually_written))
1297                         ret = -EFAULT;
1298                 buf += actually_written;
1299                 count -= actually_written;
1300                 tape->cur += actually_written;
1301                 tape->valid += actually_written;
1302
1303                 if (tape->valid == tape->buffer_size) {
1304                         ssize_t retval;
1305                         retval = idetape_add_chrdev_write_request(drive, ctl);
1306                         if (retval <= 0)
1307                                 return (retval);
1308                 }
1309         }
1310         while (count >= tape->buffer_size) {
1311                 ssize_t retval;
1312                 if (copy_from_user(tape->cur, buf, tape->buffer_size))
1313                         ret = -EFAULT;
1314                 buf += tape->buffer_size;
1315                 count -= tape->buffer_size;
1316                 retval = idetape_add_chrdev_write_request(drive, ctl);
1317                 actually_written += tape->buffer_size;
1318                 if (retval <= 0)
1319                         return (retval);
1320         }
1321         if (count) {
1322                 actually_written += count;
1323                 if (copy_from_user(tape->cur, buf, count))
1324                         ret = -EFAULT;
1325                 tape->cur += count;
1326                 tape->valid += count;
1327         }
1328         return ret ? ret : actually_written;
1329 }
1330
1331 static int idetape_write_filemark(ide_drive_t *drive)
1332 {
1333         struct ide_tape_obj *tape = drive->driver_data;
1334         struct ide_atapi_pc pc;
1335
1336         /* Write a filemark */
1337         idetape_create_write_filemark_cmd(drive, &pc, 1);
1338         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1339                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1340                 return -EIO;
1341         }
1342         return 0;
1343 }
1344
1345 /*
1346  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1347  * requested.
1348  *
1349  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1350  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1351  * usually not supported.
1352  *
1353  * The following commands are currently not supported:
1354  *
1355  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1356  * MT_ST_WRITE_THRESHOLD.
1357  */
1358 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1359 {
1360         idetape_tape_t *tape = drive->driver_data;
1361         struct gendisk *disk = tape->disk;
1362         struct ide_atapi_pc pc;
1363         int i, retval;
1364
1365         debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
1366                         mt_op, mt_count);
1367
1368         switch (mt_op) {
1369         case MTFSF:
1370         case MTFSFM:
1371         case MTBSF:
1372         case MTBSFM:
1373                 if (!mt_count)
1374                         return 0;
1375                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1376         default:
1377                 break;
1378         }
1379
1380         switch (mt_op) {
1381         case MTWEOF:
1382                 if (tape->write_prot)
1383                         return -EACCES;
1384                 ide_tape_discard_merge_buffer(drive, 1);
1385                 for (i = 0; i < mt_count; i++) {
1386                         retval = idetape_write_filemark(drive);
1387                         if (retval)
1388                                 return retval;
1389                 }
1390                 return 0;
1391         case MTREW:
1392                 ide_tape_discard_merge_buffer(drive, 0);
1393                 if (idetape_rewind_tape(drive))
1394                         return -EIO;
1395                 return 0;
1396         case MTLOAD:
1397                 ide_tape_discard_merge_buffer(drive, 0);
1398                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1399         case MTUNLOAD:
1400         case MTOFFL:
1401                 /*
1402                  * If door is locked, attempt to unlock before
1403                  * attempting to eject.
1404                  */
1405                 if (tape->door_locked) {
1406                         if (!ide_set_media_lock(drive, disk, 0))
1407                                 tape->door_locked = DOOR_UNLOCKED;
1408                 }
1409                 ide_tape_discard_merge_buffer(drive, 0);
1410                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1411                 if (!retval)
1412                         clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1413                 return retval;
1414         case MTNOP:
1415                 ide_tape_discard_merge_buffer(drive, 0);
1416                 return idetape_flush_tape_buffers(drive);
1417         case MTRETEN:
1418                 ide_tape_discard_merge_buffer(drive, 0);
1419                 return ide_do_start_stop(drive, disk,
1420                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1421         case MTEOM:
1422                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1423                 return ide_queue_pc_tail(drive, disk, &pc);
1424         case MTERASE:
1425                 (void)idetape_rewind_tape(drive);
1426                 idetape_create_erase_cmd(&pc);
1427                 return ide_queue_pc_tail(drive, disk, &pc);
1428         case MTSETBLK:
1429                 if (mt_count) {
1430                         if (mt_count < tape->blk_size ||
1431                             mt_count % tape->blk_size)
1432                                 return -EIO;
1433                         tape->user_bs_factor = mt_count / tape->blk_size;
1434                         clear_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1435                 } else
1436                         set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1437                 return 0;
1438         case MTSEEK:
1439                 ide_tape_discard_merge_buffer(drive, 0);
1440                 return idetape_position_tape(drive,
1441                         mt_count * tape->user_bs_factor, tape->partition, 0);
1442         case MTSETPART:
1443                 ide_tape_discard_merge_buffer(drive, 0);
1444                 return idetape_position_tape(drive, 0, mt_count, 0);
1445         case MTFSR:
1446         case MTBSR:
1447         case MTLOCK:
1448                 retval = ide_set_media_lock(drive, disk, 1);
1449                 if (retval)
1450                         return retval;
1451                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1452                 return 0;
1453         case MTUNLOCK:
1454                 retval = ide_set_media_lock(drive, disk, 0);
1455                 if (retval)
1456                         return retval;
1457                 tape->door_locked = DOOR_UNLOCKED;
1458                 return 0;
1459         default:
1460                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1461                                 mt_op);
1462                 return -EIO;
1463         }
1464 }
1465
1466 /*
1467  * Our character device ioctls. General mtio.h magnetic io commands are
1468  * supported here, and not in the corresponding block interface. Our own
1469  * ide-tape ioctls are supported on both interfaces.
1470  */
1471 static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
1472                                 unsigned int cmd, unsigned long arg)
1473 {
1474         struct ide_tape_obj *tape = file->private_data;
1475         ide_drive_t *drive = tape->drive;
1476         struct mtop mtop;
1477         struct mtget mtget;
1478         struct mtpos mtpos;
1479         int block_offset = 0, position = tape->first_frame;
1480         void __user *argp = (void __user *)arg;
1481
1482         debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
1483
1484         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1485                 ide_tape_flush_merge_buffer(drive);
1486                 idetape_flush_tape_buffers(drive);
1487         }
1488         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1489                 block_offset = tape->valid /
1490                         (tape->blk_size * tape->user_bs_factor);
1491                 position = idetape_read_position(drive);
1492                 if (position < 0)
1493                         return -EIO;
1494         }
1495         switch (cmd) {
1496         case MTIOCTOP:
1497                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1498                         return -EFAULT;
1499                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1500         case MTIOCGET:
1501                 memset(&mtget, 0, sizeof(struct mtget));
1502                 mtget.mt_type = MT_ISSCSI2;
1503                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1504                 mtget.mt_dsreg =
1505                         ((tape->blk_size * tape->user_bs_factor)
1506                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1507
1508                 if (tape->drv_write_prot)
1509                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1510
1511                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1512                         return -EFAULT;
1513                 return 0;
1514         case MTIOCPOS:
1515                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1516                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1517                         return -EFAULT;
1518                 return 0;
1519         default:
1520                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1521                         ide_tape_discard_merge_buffer(drive, 1);
1522                 return idetape_blkdev_ioctl(drive, cmd, arg);
1523         }
1524 }
1525
1526 /*
1527  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1528  * block size with the reported value.
1529  */
1530 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1531 {
1532         idetape_tape_t *tape = drive->driver_data;
1533         struct ide_atapi_pc pc;
1534
1535         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1536         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1537                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1538                 if (tape->blk_size == 0) {
1539                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1540                                             "block size, assuming 32k\n");
1541                         tape->blk_size = 32768;
1542                 }
1543                 return;
1544         }
1545         tape->blk_size = (pc.buf[4 + 5] << 16) +
1546                                 (pc.buf[4 + 6] << 8)  +
1547                                  pc.buf[4 + 7];
1548         tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7;
1549 }
1550
1551 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1552 {
1553         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1554         ide_drive_t *drive;
1555         idetape_tape_t *tape;
1556         int retval;
1557
1558         if (i >= MAX_HWIFS * MAX_DRIVES)
1559                 return -ENXIO;
1560
1561         lock_kernel();
1562         tape = ide_tape_chrdev_get(i);
1563         if (!tape) {
1564                 unlock_kernel();
1565                 return -ENXIO;
1566         }
1567
1568         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1569
1570         /*
1571          * We really want to do nonseekable_open(inode, filp); here, but some
1572          * versions of tar incorrectly call lseek on tapes and bail out if that
1573          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1574          */
1575         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1576
1577         drive = tape->drive;
1578
1579         filp->private_data = tape;
1580
1581         if (test_and_set_bit(IDE_AFLAG_BUSY, &drive->atapi_flags)) {
1582                 retval = -EBUSY;
1583                 goto out_put_tape;
1584         }
1585
1586         retval = idetape_wait_ready(drive, 60 * HZ);
1587         if (retval) {
1588                 clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1589                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1590                 goto out_put_tape;
1591         }
1592
1593         idetape_read_position(drive);
1594         if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags))
1595                 (void)idetape_rewind_tape(drive);
1596
1597         /* Read block size and write protect status from drive. */
1598         ide_tape_get_bsize_from_bdesc(drive);
1599
1600         /* Set write protect flag if device is opened as read-only. */
1601         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1602                 tape->write_prot = 1;
1603         else
1604                 tape->write_prot = tape->drv_write_prot;
1605
1606         /* Make sure drive isn't write protected if user wants to write. */
1607         if (tape->write_prot) {
1608                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1609                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1610                         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1611                         retval = -EROFS;
1612                         goto out_put_tape;
1613                 }
1614         }
1615
1616         /* Lock the tape drive door so user can't eject. */
1617         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1618                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1619                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1620                                 tape->door_locked = DOOR_LOCKED;
1621                 }
1622         }
1623         unlock_kernel();
1624         return 0;
1625
1626 out_put_tape:
1627         ide_tape_put(tape);
1628         unlock_kernel();
1629         return retval;
1630 }
1631
1632 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1633 {
1634         idetape_tape_t *tape = drive->driver_data;
1635
1636         ide_tape_flush_merge_buffer(drive);
1637         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1638         if (tape->buf != NULL) {
1639                 idetape_pad_zeros(drive, tape->blk_size *
1640                                 (tape->user_bs_factor - 1));
1641                 kfree(tape->buf);
1642                 tape->buf = NULL;
1643         }
1644         idetape_write_filemark(drive);
1645         idetape_flush_tape_buffers(drive);
1646         idetape_flush_tape_buffers(drive);
1647 }
1648
1649 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1650 {
1651         struct ide_tape_obj *tape = filp->private_data;
1652         ide_drive_t *drive = tape->drive;
1653         unsigned int minor = iminor(inode);
1654
1655         lock_kernel();
1656         tape = drive->driver_data;
1657
1658         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1659
1660         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1661                 idetape_write_release(drive, minor);
1662         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1663                 if (minor < 128)
1664                         ide_tape_discard_merge_buffer(drive, 1);
1665         }
1666
1667         if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags))
1668                 (void) idetape_rewind_tape(drive);
1669         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1670                 if (tape->door_locked == DOOR_LOCKED) {
1671                         if (!ide_set_media_lock(drive, tape->disk, 0))
1672                                 tape->door_locked = DOOR_UNLOCKED;
1673                 }
1674         }
1675         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1676         ide_tape_put(tape);
1677         unlock_kernel();
1678         return 0;
1679 }
1680
1681 static void idetape_get_inquiry_results(ide_drive_t *drive)
1682 {
1683         idetape_tape_t *tape = drive->driver_data;
1684         struct ide_atapi_pc pc;
1685         u8 pc_buf[256];
1686         char fw_rev[4], vendor_id[8], product_id[16];
1687
1688         idetape_create_inquiry_cmd(&pc);
1689         pc.buf = &pc_buf[0];
1690         pc.buf_size = sizeof(pc_buf);
1691
1692         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1693                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1694                                 tape->name);
1695                 return;
1696         }
1697         memcpy(vendor_id, &pc.buf[8], 8);
1698         memcpy(product_id, &pc.buf[16], 16);
1699         memcpy(fw_rev, &pc.buf[32], 4);
1700
1701         ide_fixstring(vendor_id, 8, 0);
1702         ide_fixstring(product_id, 16, 0);
1703         ide_fixstring(fw_rev, 4, 0);
1704
1705         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1706                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1707 }
1708
1709 /*
1710  * Ask the tape about its various parameters. In particular, we will adjust our
1711  * data transfer buffer size to the recommended value as returned by the tape.
1712  */
1713 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1714 {
1715         idetape_tape_t *tape = drive->driver_data;
1716         struct ide_atapi_pc pc;
1717         u8 *caps;
1718         u8 speed, max_speed;
1719
1720         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1721         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1722                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1723                                 " some default values\n");
1724                 tape->blk_size = 512;
1725                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1726                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1727                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1728                 return;
1729         }
1730         caps = pc.buf + 4 + pc.buf[3];
1731
1732         /* convert to host order and save for later use */
1733         speed = be16_to_cpup((__be16 *)&caps[14]);
1734         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1735
1736         *(u16 *)&caps[8] = max_speed;
1737         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1738         *(u16 *)&caps[14] = speed;
1739         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1740
1741         if (!speed) {
1742                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1743                                 "(assuming 650KB/sec)\n", drive->name);
1744                 *(u16 *)&caps[14] = 650;
1745         }
1746         if (!max_speed) {
1747                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1748                                 "(assuming 650KB/sec)\n", drive->name);
1749                 *(u16 *)&caps[8] = 650;
1750         }
1751
1752         memcpy(&tape->caps, caps, 20);
1753
1754         /* device lacks locking support according to capabilities page */
1755         if ((caps[6] & 1) == 0)
1756                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1757
1758         if (caps[7] & 0x02)
1759                 tape->blk_size = 512;
1760         else if (caps[7] & 0x04)
1761                 tape->blk_size = 1024;
1762 }
1763
1764 #ifdef CONFIG_IDE_PROC_FS
1765 #define ide_tape_devset_get(name, field) \
1766 static int get_##name(ide_drive_t *drive) \
1767 { \
1768         idetape_tape_t *tape = drive->driver_data; \
1769         return tape->field; \
1770 }
1771
1772 #define ide_tape_devset_set(name, field) \
1773 static int set_##name(ide_drive_t *drive, int arg) \
1774 { \
1775         idetape_tape_t *tape = drive->driver_data; \
1776         tape->field = arg; \
1777         return 0; \
1778 }
1779
1780 #define ide_tape_devset_rw_field(_name, _field) \
1781 ide_tape_devset_get(_name, _field) \
1782 ide_tape_devset_set(_name, _field) \
1783 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1784
1785 #define ide_tape_devset_r_field(_name, _field) \
1786 ide_tape_devset_get(_name, _field) \
1787 IDE_DEVSET(_name, 0, get_##_name, NULL)
1788
1789 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1790 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1791 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1792 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1793
1794 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1795
1796 ide_tape_devset_rw_field(debug_mask, debug_mask);
1797 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1798
1799 ide_tape_devset_r_field(avg_speed, avg_speed);
1800 ide_tape_devset_r_field(speed, caps[14]);
1801 ide_tape_devset_r_field(buffer, caps[16]);
1802 ide_tape_devset_r_field(buffer_size, buffer_size);
1803
1804 static const struct ide_proc_devset idetape_settings[] = {
1805         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1806         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1807         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1808         __IDE_PROC_DEVSET(debug_mask,   0, 0xffff, NULL, NULL),
1809         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1810         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1811         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1812                                         mulf_tdsc, divf_tdsc),
1813         { NULL },
1814 };
1815 #endif
1816
1817 /*
1818  * The function below is called to:
1819  *
1820  * 1. Initialize our various state variables.
1821  * 2. Ask the tape for its capabilities.
1822  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1823  * is chosen based on the recommendation which we received in step 2.
1824  *
1825  * Note that at this point ide.c already assigned us an irq, so that we can
1826  * queue requests here and wait for their completion.
1827  */
1828 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1829 {
1830         unsigned long t;
1831         int speed;
1832         int buffer_size;
1833         u16 *ctl = (u16 *)&tape->caps[12];
1834
1835         drive->pc_callback       = ide_tape_callback;
1836
1837         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1838
1839         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1840                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1841                                  tape->name);
1842                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1843         }
1844
1845         /* Seagate Travan drives do not support DSC overlap. */
1846         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1847                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1848
1849         tape->minor = minor;
1850         tape->name[0] = 'h';
1851         tape->name[1] = 't';
1852         tape->name[2] = '0' + minor;
1853         tape->chrdev_dir = IDETAPE_DIR_NONE;
1854
1855         idetape_get_inquiry_results(drive);
1856         idetape_get_mode_sense_results(drive);
1857         ide_tape_get_bsize_from_bdesc(drive);
1858         tape->user_bs_factor = 1;
1859         tape->buffer_size = *ctl * tape->blk_size;
1860         while (tape->buffer_size > 0xffff) {
1861                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1862                 *ctl /= 2;
1863                 tape->buffer_size = *ctl * tape->blk_size;
1864         }
1865         buffer_size = tape->buffer_size;
1866
1867         /* select the "best" DSC read/write polling freq */
1868         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1869
1870         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1871
1872         /*
1873          * Ensure that the number we got makes sense; limit it within
1874          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1875          */
1876         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1877                                          IDETAPE_DSC_RW_MAX);
1878         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1879                 "%lums tDSC%s\n",
1880                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1881                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1882                 tape->buffer_size / 1024,
1883                 tape->best_dsc_rw_freq * 1000 / HZ,
1884                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1885
1886         ide_proc_register_driver(drive, tape->driver);
1887 }
1888
1889 static void ide_tape_remove(ide_drive_t *drive)
1890 {
1891         idetape_tape_t *tape = drive->driver_data;
1892
1893         ide_proc_unregister_driver(drive, tape->driver);
1894         device_del(&tape->dev);
1895         ide_unregister_region(tape->disk);
1896
1897         mutex_lock(&idetape_ref_mutex);
1898         put_device(&tape->dev);
1899         mutex_unlock(&idetape_ref_mutex);
1900 }
1901
1902 static void ide_tape_release(struct device *dev)
1903 {
1904         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1905         ide_drive_t *drive = tape->drive;
1906         struct gendisk *g = tape->disk;
1907
1908         BUG_ON(tape->valid);
1909
1910         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1911         drive->driver_data = NULL;
1912         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1913         device_destroy(idetape_sysfs_class,
1914                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1915         idetape_devs[tape->minor] = NULL;
1916         g->private_data = NULL;
1917         put_disk(g);
1918         kfree(tape);
1919 }
1920
1921 #ifdef CONFIG_IDE_PROC_FS
1922 static int proc_idetape_read_name
1923         (char *page, char **start, off_t off, int count, int *eof, void *data)
1924 {
1925         ide_drive_t     *drive = (ide_drive_t *) data;
1926         idetape_tape_t  *tape = drive->driver_data;
1927         char            *out = page;
1928         int             len;
1929
1930         len = sprintf(out, "%s\n", tape->name);
1931         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
1932 }
1933
1934 static ide_proc_entry_t idetape_proc[] = {
1935         { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
1936         { "name",       S_IFREG|S_IRUGO,        proc_idetape_read_name, NULL },
1937         { NULL, 0, NULL, NULL }
1938 };
1939
1940 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1941 {
1942         return idetape_proc;
1943 }
1944
1945 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1946 {
1947         return idetape_settings;
1948 }
1949 #endif
1950
1951 static int ide_tape_probe(ide_drive_t *);
1952
1953 static struct ide_driver idetape_driver = {
1954         .gen_driver = {
1955                 .owner          = THIS_MODULE,
1956                 .name           = "ide-tape",
1957                 .bus            = &ide_bus_type,
1958         },
1959         .probe                  = ide_tape_probe,
1960         .remove                 = ide_tape_remove,
1961         .version                = IDETAPE_VERSION,
1962         .do_request             = idetape_do_request,
1963 #ifdef CONFIG_IDE_PROC_FS
1964         .proc_entries           = ide_tape_proc_entries,
1965         .proc_devsets           = ide_tape_proc_devsets,
1966 #endif
1967 };
1968
1969 /* Our character device supporting functions, passed to register_chrdev. */
1970 static const struct file_operations idetape_fops = {
1971         .owner          = THIS_MODULE,
1972         .read           = idetape_chrdev_read,
1973         .write          = idetape_chrdev_write,
1974         .ioctl          = idetape_chrdev_ioctl,
1975         .open           = idetape_chrdev_open,
1976         .release        = idetape_chrdev_release,
1977 };
1978
1979 static int idetape_open(struct block_device *bdev, fmode_t mode)
1980 {
1981         struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk);
1982
1983         if (!tape)
1984                 return -ENXIO;
1985
1986         return 0;
1987 }
1988
1989 static int idetape_release(struct gendisk *disk, fmode_t mode)
1990 {
1991         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1992
1993         ide_tape_put(tape);
1994         return 0;
1995 }
1996
1997 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1998                         unsigned int cmd, unsigned long arg)
1999 {
2000         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
2001         ide_drive_t *drive = tape->drive;
2002         int err = generic_ide_ioctl(drive, bdev, cmd, arg);
2003         if (err == -EINVAL)
2004                 err = idetape_blkdev_ioctl(drive, cmd, arg);
2005         return err;
2006 }
2007
2008 static struct block_device_operations idetape_block_ops = {
2009         .owner          = THIS_MODULE,
2010         .open           = idetape_open,
2011         .release        = idetape_release,
2012         .locked_ioctl   = idetape_ioctl,
2013 };
2014
2015 static int ide_tape_probe(ide_drive_t *drive)
2016 {
2017         idetape_tape_t *tape;
2018         struct gendisk *g;
2019         int minor;
2020
2021         if (!strstr("ide-tape", drive->driver_req))
2022                 goto failed;
2023
2024         if (drive->media != ide_tape)
2025                 goto failed;
2026
2027         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
2028             ide_check_atapi_device(drive, DRV_NAME) == 0) {
2029                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
2030                                 " the driver\n", drive->name);
2031                 goto failed;
2032         }
2033         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
2034         if (tape == NULL) {
2035                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
2036                                 drive->name);
2037                 goto failed;
2038         }
2039
2040         g = alloc_disk(1 << PARTN_BITS);
2041         if (!g)
2042                 goto out_free_tape;
2043
2044         ide_init_disk(g, drive);
2045
2046         tape->dev.parent = &drive->gendev;
2047         tape->dev.release = ide_tape_release;
2048         dev_set_name(&tape->dev, dev_name(&drive->gendev));
2049
2050         if (device_register(&tape->dev))
2051                 goto out_free_disk;
2052
2053         tape->drive = drive;
2054         tape->driver = &idetape_driver;
2055         tape->disk = g;
2056
2057         g->private_data = &tape->driver;
2058
2059         drive->driver_data = tape;
2060
2061         mutex_lock(&idetape_ref_mutex);
2062         for (minor = 0; idetape_devs[minor]; minor++)
2063                 ;
2064         idetape_devs[minor] = tape;
2065         mutex_unlock(&idetape_ref_mutex);
2066
2067         idetape_setup(drive, tape, minor);
2068
2069         device_create(idetape_sysfs_class, &drive->gendev,
2070                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2071         device_create(idetape_sysfs_class, &drive->gendev,
2072                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2073                       "n%s", tape->name);
2074
2075         g->fops = &idetape_block_ops;
2076         ide_register_region(g);
2077
2078         return 0;
2079
2080 out_free_disk:
2081         put_disk(g);
2082 out_free_tape:
2083         kfree(tape);
2084 failed:
2085         return -ENODEV;
2086 }
2087
2088 static void __exit idetape_exit(void)
2089 {
2090         driver_unregister(&idetape_driver.gen_driver);
2091         class_destroy(idetape_sysfs_class);
2092         unregister_chrdev(IDETAPE_MAJOR, "ht");
2093 }
2094
2095 static int __init idetape_init(void)
2096 {
2097         int error = 1;
2098         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2099         if (IS_ERR(idetape_sysfs_class)) {
2100                 idetape_sysfs_class = NULL;
2101                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2102                 error = -EBUSY;
2103                 goto out;
2104         }
2105
2106         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2107                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2108                                 " interface\n");
2109                 error = -EBUSY;
2110                 goto out_free_class;
2111         }
2112
2113         error = driver_register(&idetape_driver.gen_driver);
2114         if (error)
2115                 goto out_free_driver;
2116
2117         return 0;
2118
2119 out_free_driver:
2120         driver_unregister(&idetape_driver.gen_driver);
2121 out_free_class:
2122         class_destroy(idetape_sysfs_class);
2123 out:
2124         return error;
2125 }
2126
2127 MODULE_ALIAS("ide:*m-tape*");
2128 module_init(idetape_init);
2129 module_exit(idetape_exit);
2130 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2131 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2132 MODULE_LICENSE("GPL");