git.oblomov.eu Git - linux-2.6/blob - 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->buf = NULL;
 595         pc->buf_size = length * tape->blk_size;
 596         pc->req_xfer = pc->buf_size;
 597         if (pc->req_xfer == tape->buffer_size)
 598                 pc->flags |= PC_FLAG_DMA_OK;
 599
 600         if (opcode == READ_6)
 601                 pc->c[0] = READ_6;
 602         else if (opcode == WRITE_6) {
 603                 pc->c[0] = WRITE_6;
 604                 pc->flags |= PC_FLAG_WRITING;
 605         }
 606
 607         memcpy(rq->cmd, pc->c, 12);
 608 }
 609
 610 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 611                                           struct request *rq, sector_t block)
 612 {
 613         ide_hwif_t *hwif = drive->hwif;
 614         idetape_tape_t *tape = drive->driver_data;
 615         struct ide_atapi_pc *pc = NULL;
 616         struct request *postponed_rq = tape->postponed_rq;
 617         struct ide_cmd cmd;
 618         u8 stat;
 619
 620         debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %lu\n"
 621                   (unsigned long long)rq->sector, rq->nr_sectors);
 622
 623         if (!(blk_special_request(rq) || blk_sense_request(rq))) {
 624                 /* We do not support buffer cache originated requests. */
 625                 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
 626                         "request queue (%d)\n", drive->name, rq->cmd_type);
 627                 if (blk_fs_request(rq) == 0 && rq->errors == 0)
 628                         rq->errors = -EIO;
 629                 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
 630                 return ide_stopped;
 631         }
 632
 633         /* Retry a failed packet command */
 634         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 635                 pc = drive->failed_pc;
 636                 goto out;
 637         }
 638
 639         if (postponed_rq != NULL)
 640                 if (rq != postponed_rq) {
 641                         printk(KERN_ERR "ide-tape: ide-tape.c bug - "
 642                                         "Two DSC requests were queued\n");
 643                         drive->failed_pc = NULL;
 644                         rq->errors = 0;
 645                         ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 646                         return ide_stopped;
 647                 }
 648
 649         tape->postponed_rq = NULL;
 650
 651         /*
 652          * If the tape is still busy, postpone our request and service
 653          * the other device meanwhile.
 654          */
 655         stat = hwif->tp_ops->read_status(hwif);
 656
 657         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 658             (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
 659                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 660
 661         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 662                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 663                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 664         }
 665
 666         if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) &&
 667             (stat & ATA_DSC) == 0) {
 668                 if (postponed_rq == NULL) {
 669                         tape->dsc_polling_start = jiffies;
 670                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 671                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 672                 } else if (time_after(jiffies, tape->dsc_timeout)) {
 673                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 674                                 tape->name);
 675                         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 676                                 idetape_media_access_finished(drive);
 677                                 return ide_stopped;
 678                         } else {
 679                                 return ide_do_reset(drive);
 680                         }
 681                 } else if (time_after(jiffies,
 682                                         tape->dsc_polling_start +
 683                                         IDETAPE_DSC_MA_THRESHOLD))
 684                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 685                 idetape_postpone_request(drive);
 686                 return ide_stopped;
 687         }
 688         if (rq->cmd[13] & REQ_IDETAPE_READ) {
 689                 pc = &tape->queued_pc;
 690                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 691                 goto out;
 692         }
 693         if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
 694                 pc = &tape->queued_pc;
 695                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 696                 goto out;
 697         }
 698         if (rq->cmd[13] & REQ_IDETAPE_PC1) {
 699                 pc = (struct ide_atapi_pc *)rq->special;
 700                 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
 701                 rq->cmd[13] |= REQ_IDETAPE_PC2;
 702                 goto out;
 703         }
 704         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 705                 idetape_media_access_finished(drive);
 706                 return ide_stopped;
 707         }
 708         BUG();
 709
 710 out:
 711         /* prepare sense request for this command */
 712         ide_prep_sense(drive, rq);
 713
 714         memset(&cmd, 0, sizeof(cmd));
 715
 716         if (rq_data_dir(rq))
 717                 cmd.tf_flags |= IDE_TFLAG_WRITE;
 718
 719         cmd.rq = rq;
 720
 721         ide_init_sg_cmd(&cmd, pc->req_xfer);
 722         ide_map_sg(drive, &cmd);
 723
 724         return ide_tape_issue_pc(drive, &cmd, pc);
 725 }
 726
 727 /*
 728  * Write a filemark if write_filemark=1. Flush the device buffers without
 729  * writing a filemark otherwise.
 730  */
 731 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 732                 struct ide_atapi_pc *pc, int write_filemark)
 733 {
 734         ide_init_pc(pc);
 735         pc->c[0] = WRITE_FILEMARKS;
 736         pc->c[4] = write_filemark;
 737         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 738 }
 739
 740 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 741 {
 742         idetape_tape_t *tape = drive->driver_data;
 743         struct gendisk *disk = tape->disk;
 744         int load_attempted = 0;
 745
 746         /* Wait for the tape to become ready */
 747         set_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
 748         timeout += jiffies;
 749         while (time_before(jiffies, timeout)) {
 750                 if (ide_do_test_unit_ready(drive, disk) == 0)
 751                         return 0;
 752                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 753                     || (tape->asc == 0x3A)) {
 754                         /* no media */
 755                         if (load_attempted)
 756                                 return -ENOMEDIUM;
 757                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 758                         load_attempted = 1;
 759                 /* not about to be ready */
 760                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 761                              (tape->ascq == 1 || tape->ascq == 8)))
 762                         return -EIO;
 763                 msleep(100);
 764         }
 765         return -EIO;
 766 }
 767
 768 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 769 {
 770         struct ide_tape_obj *tape = drive->driver_data;
 771         struct ide_atapi_pc pc;
 772         int rc;
 773
 774         idetape_create_write_filemark_cmd(drive, &pc, 0);
 775         rc = ide_queue_pc_tail(drive, tape->disk, &pc);
 776         if (rc)
 777                 return rc;
 778         idetape_wait_ready(drive, 60 * 5 * HZ);
 779         return 0;
 780 }
 781
 782 static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc)
 783 {
 784         ide_init_pc(pc);
 785         pc->c[0] = READ_POSITION;
 786         pc->req_xfer = 20;
 787 }
 788
 789 static int idetape_read_position(ide_drive_t *drive)
 790 {
 791         idetape_tape_t *tape = drive->driver_data;
 792         struct ide_atapi_pc pc;
 793         int position;
 794
 795         debug_log(DBG_PROCS, "Enter %s\n", __func__);
 796
 797         idetape_create_read_position_cmd(&pc);
 798         if (ide_queue_pc_tail(drive, tape->disk, &pc))
 799                 return -1;
 800         position = tape->first_frame;
 801         return position;
 802 }
 803
 804 static void idetape_create_locate_cmd(ide_drive_t *drive,
 805                 struct ide_atapi_pc *pc,
 806                 unsigned int block, u8 partition, int skip)
 807 {
 808         ide_init_pc(pc);
 809         pc->c[0] = POSITION_TO_ELEMENT;
 810         pc->c[1] = 2;
 811         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 812         pc->c[8] = partition;
 813         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 814 }
 815
 816 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 817 {
 818         idetape_tape_t *tape = drive->driver_data;
 819
 820         if (tape->chrdev_dir != IDETAPE_DIR_READ)
 821                 return;
 822
 823         clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags);
 824         tape->valid = 0;
 825         if (tape->buf != NULL) {
 826                 kfree(tape->buf);
 827                 tape->buf = NULL;
 828         }
 829
 830         tape->chrdev_dir = IDETAPE_DIR_NONE;
 831 }
 832
 833 /*
 834  * Position the tape to the requested block using the LOCATE packet command.
 835  * A READ POSITION command is then issued to check where we are positioned. Like
 836  * all higher level operations, we queue the commands at the tail of the request
 837  * queue and wait for their completion.
 838  */
 839 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 840                 u8 partition, int skip)
 841 {
 842         idetape_tape_t *tape = drive->driver_data;
 843         struct gendisk *disk = tape->disk;
 844         int retval;
 845         struct ide_atapi_pc pc;
 846
 847         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 848                 __ide_tape_discard_merge_buffer(drive);
 849         idetape_wait_ready(drive, 60 * 5 * HZ);
 850         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 851         retval = ide_queue_pc_tail(drive, disk, &pc);
 852         if (retval)
 853                 return (retval);
 854
 855         idetape_create_read_position_cmd(&pc);
 856         return ide_queue_pc_tail(drive, disk, &pc);
 857 }
 858
 859 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 860                                           int restore_position)
 861 {
 862         idetape_tape_t *tape = drive->driver_data;
 863         int seek, position;
 864
 865         __ide_tape_discard_merge_buffer(drive);
 866         if (restore_position) {
 867                 position = idetape_read_position(drive);
 868                 seek = position > 0 ? position : 0;
 869                 if (idetape_position_tape(drive, seek, 0, 0)) {
 870                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 871                                          " %s\n", tape->name, __func__);
 872                         return;
 873                 }
 874         }
 875 }
 876
 877 /*
 878  * Generate a read/write request for the block device interface and wait for it
 879  * to be serviced.
 880  */
 881 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 882 {
 883         idetape_tape_t *tape = drive->driver_data;
 884         struct request *rq;
 885         int ret;
 886
 887         debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
 888         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 889         BUG_ON(size < 0 || size % tape->blk_size);
 890
 891         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
 892         rq->cmd_type = REQ_TYPE_SPECIAL;
 893         rq->cmd[13] = cmd;
 894         rq->rq_disk = tape->disk;
 895         rq->sector = tape->first_frame;
 896
 897         if (size) {
 898                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 899                                       __GFP_WAIT);
 900                 if (ret)
 901                         goto out_put;
 902         }
 903
 904         blk_execute_rq(drive->queue, tape->disk, rq, 0);
 905
 906         /* calculate the number of transferred bytes and update buffer state */
 907         size -= rq->data_len;
 908         tape->cur = tape->buf;
 909         if (cmd == REQ_IDETAPE_READ)
 910                 tape->valid = size;
 911         else
 912                 tape->valid = 0;
 913
 914         ret = size;
 915         if (rq->errors == IDE_DRV_ERROR_GENERAL)
 916                 ret = -EIO;
 917 out_put:
 918         blk_put_request(rq);
 919         return ret;
 920 }
 921
 922 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 923 {
 924         ide_init_pc(pc);
 925         pc->c[0] = INQUIRY;
 926         pc->c[4] = 254;
 927         pc->req_xfer = 254;
 928 }
 929
 930 static void idetape_create_rewind_cmd(ide_drive_t *drive,
 931                 struct ide_atapi_pc *pc)
 932 {
 933         ide_init_pc(pc);
 934         pc->c[0] = REZERO_UNIT;
 935         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 936 }
 937
 938 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 939 {
 940         ide_init_pc(pc);
 941         pc->c[0] = ERASE;
 942         pc->c[1] = 1;
 943         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 944 }
 945
 946 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 947 {
 948         ide_init_pc(pc);
 949         pc->c[0] = SPACE;
 950         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 951         pc->c[1] = cmd;
 952         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 953 }
 954
 955 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 956 {
 957         idetape_tape_t *tape = drive->driver_data;
 958
 959         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 960                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 961                                 " but we are not writing.\n");
 962                 return;
 963         }
 964         if (tape->buf) {
 965                 size_t aligned = roundup(tape->valid, tape->blk_size);
 966
 967                 memset(tape->cur, 0, aligned - tape->valid);
 968                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 969                 kfree(tape->buf);
 970                 tape->buf = NULL;
 971         }
 972         tape->chrdev_dir = IDETAPE_DIR_NONE;
 973 }
 974
 975 static int idetape_init_rw(ide_drive_t *drive, int dir)
 976 {
 977         idetape_tape_t *tape = drive->driver_data;
 978         int rc;
 979
 980         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 981
 982         if (tape->chrdev_dir == dir)
 983                 return 0;
 984
 985         if (tape->chrdev_dir == IDETAPE_DIR_READ)
 986                 ide_tape_discard_merge_buffer(drive, 1);
 987         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 988                 ide_tape_flush_merge_buffer(drive);
 989                 idetape_flush_tape_buffers(drive);
 990         }
 991
 992         if (tape->buf || tape->valid) {
 993                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 994                 tape->valid = 0;
 995         }
 996
 997         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 998         if (!tape->buf)
 999                 return -ENOMEM;
1000         tape->chrdev_dir = dir;
1001         tape->cur = tape->buf;
1002
1003         /*
1004          * Issue a 0 rw command to ensure that DSC handshake is
1005          * switched from completion mode to buffer available mode.  No
1006          * point in issuing this if DSC overlap isn't supported, some
1007          * drives (Seagate STT3401A) will return an error.
1008          */
1009         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1010                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
1011                                                   : REQ_IDETAPE_WRITE;
1012
1013                 rc = idetape_queue_rw_tail(drive, cmd, 0);
1014                 if (rc < 0) {
1015                         kfree(tape->buf);
1016                         tape->buf = NULL;
1017                         tape->chrdev_dir = IDETAPE_DIR_NONE;
1018                         return rc;
1019                 }
1020         }
1021
1022         return 0;
1023 }
1024
1025 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
1026 {
1027         idetape_tape_t *tape = drive->driver_data;
1028
1029         memset(tape->buf, 0, tape->buffer_size);
1030
1031         while (bcount) {
1032                 unsigned int count = min(tape->buffer_size, bcount);
1033
1034                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1035                 bcount -= count;
1036         }
1037 }
1038
1039 /*
1040  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1041  * currently support only one partition.
1042  */
1043 static int idetape_rewind_tape(ide_drive_t *drive)
1044 {
1045         struct ide_tape_obj *tape = drive->driver_data;
1046         struct gendisk *disk = tape->disk;
1047         int retval;
1048         struct ide_atapi_pc pc;
1049
1050         debug_log(DBG_SENSE, "Enter %s\n", __func__);
1051
1052         idetape_create_rewind_cmd(drive, &pc);
1053         retval = ide_queue_pc_tail(drive, disk, &pc);
1054         if (retval)
1055                 return retval;
1056
1057         idetape_create_read_position_cmd(&pc);
1058         retval = ide_queue_pc_tail(drive, disk, &pc);
1059         if (retval)
1060                 return retval;
1061         return 0;
1062 }
1063
1064 /* mtio.h compatible commands should be issued to the chrdev interface. */
1065 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1066                                 unsigned long arg)
1067 {
1068         idetape_tape_t *tape = drive->driver_data;
1069         void __user *argp = (void __user *)arg;
1070
1071         struct idetape_config {
1072                 int dsc_rw_frequency;
1073                 int dsc_media_access_frequency;
1074                 int nr_stages;
1075         } config;
1076
1077         debug_log(DBG_PROCS, "Enter %s\n", __func__);
1078
1079         switch (cmd) {
1080         case 0x0340:
1081                 if (copy_from_user(&config, argp, sizeof(config)))
1082                         return -EFAULT;
1083                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1084                 break;
1085         case 0x0350:
1086                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1087                 config.nr_stages = 1;
1088                 if (copy_to_user(argp, &config, sizeof(config)))
1089                         return -EFAULT;
1090                 break;
1091         default:
1092                 return -EIO;
1093         }
1094         return 0;
1095 }
1096
1097 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1098                                         int mt_count)
1099 {
1100         idetape_tape_t *tape = drive->driver_data;
1101         struct gendisk *disk = tape->disk;
1102         struct ide_atapi_pc pc;
1103         int retval, count = 0;
1104         int sprev = !!(tape->caps[4] & 0x20);
1105
1106         if (mt_count == 0)
1107                 return 0;
1108         if (MTBSF == mt_op || MTBSFM == mt_op) {
1109                 if (!sprev)
1110                         return -EIO;
1111                 mt_count = -mt_count;
1112         }
1113
1114         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1115                 tape->valid = 0;
1116                 if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1117                         ++count;
1118                 ide_tape_discard_merge_buffer(drive, 0);
1119         }
1120
1121         switch (mt_op) {
1122         case MTFSF:
1123         case MTBSF:
1124                 idetape_create_space_cmd(&pc, mt_count - count,
1125                                          IDETAPE_SPACE_OVER_FILEMARK);
1126                 return ide_queue_pc_tail(drive, disk, &pc);
1127         case MTFSFM:
1128         case MTBSFM:
1129                 if (!sprev)
1130                         return -EIO;
1131                 retval = idetape_space_over_filemarks(drive, MTFSF,
1132                                                       mt_count - count);
1133                 if (retval)
1134                         return retval;
1135                 count = (MTBSFM == mt_op ? 1 : -1);
1136                 return idetape_space_over_filemarks(drive, MTFSF, count);
1137         default:
1138                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1139                                 mt_op);
1140                 return -EIO;
1141         }
1142 }
1143
1144 /*
1145  * Our character device read / write functions.
1146  *
1147  * The tape is optimized to maximize throughput when it is transferring an
1148  * integral number of the "continuous transfer limit", which is a parameter of
1149  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1150  *
1151  * As of version 1.3 of the driver, the character device provides an abstract
1152  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1153  * same backup/restore procedure is supported. The driver will internally
1154  * convert the requests to the recommended transfer unit, so that an unmatch
1155  * between the user's block size to the recommended size will only result in a
1156  * (slightly) increased driver overhead, but will no longer hit performance.
1157  * This is not applicable to Onstream.
1158  */
1159 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1160                                    size_t count, loff_t *ppos)
1161 {
1162         struct ide_tape_obj *tape = file->private_data;
1163         ide_drive_t *drive = tape->drive;
1164         size_t done = 0;
1165         ssize_t ret = 0;
1166         int rc;
1167
1168         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1169
1170         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1171                 if (test_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags))
1172                         if (count > tape->blk_size &&
1173                             (count % tape->blk_size) == 0)
1174                                 tape->user_bs_factor = count / tape->blk_size;
1175         }
1176
1177         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1178         if (rc < 0)
1179                 return rc;
1180
1181         while (done < count) {
1182                 size_t todo;
1183
1184                 /* refill if staging buffer is empty */
1185                 if (!tape->valid) {
1186                         /* If we are at a filemark, nothing more to read */
1187                         if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1188                                 break;
1189                         /* read */
1190                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1191                                                   tape->buffer_size) <= 0)
1192                                 break;
1193                 }
1194
1195                 /* copy out */
1196                 todo = min_t(size_t, count - done, tape->valid);
1197                 if (copy_to_user(buf + done, tape->cur, todo))
1198                         ret = -EFAULT;
1199
1200                 tape->cur += todo;
1201                 tape->valid -= todo;
1202                 done += todo;
1203         }
1204
1205         if (!done && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) {
1206                 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
1207
1208                 idetape_space_over_filemarks(drive, MTFSF, 1);
1209                 return 0;
1210         }
1211
1212         return ret ? ret : done;
1213 }
1214
1215 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1216                                      size_t count, loff_t *ppos)
1217 {
1218         struct ide_tape_obj *tape = file->private_data;
1219         ide_drive_t *drive = tape->drive;
1220         size_t done = 0;
1221         ssize_t ret = 0;
1222         int rc;
1223
1224         /* The drive is write protected. */
1225         if (tape->write_prot)
1226                 return -EACCES;
1227
1228         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1229
1230         /* Initialize write operation */
1231         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1232         if (rc < 0)
1233                 return rc;
1234
1235         while (done < count) {
1236                 size_t todo;
1237
1238                 /* flush if staging buffer is full */
1239                 if (tape->valid == tape->buffer_size &&
1240                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1241                                           tape->buffer_size) <= 0)
1242                         return rc;
1243
1244                 /* copy in */
1245                 todo = min_t(size_t, count - done,
1246                              tape->buffer_size - tape->valid);
1247                 if (copy_from_user(tape->cur, buf + done, todo))
1248                         ret = -EFAULT;
1249
1250                 tape->cur += todo;
1251                 tape->valid += todo;
1252                 done += todo;
1253         }
1254
1255         return ret ? ret : done;
1256 }
1257
1258 static int idetape_write_filemark(ide_drive_t *drive)
1259 {
1260         struct ide_tape_obj *tape = drive->driver_data;
1261         struct ide_atapi_pc pc;
1262
1263         /* Write a filemark */
1264         idetape_create_write_filemark_cmd(drive, &pc, 1);
1265         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1266                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1267                 return -EIO;
1268         }
1269         return 0;
1270 }
1271
1272 /*
1273  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1274  * requested.
1275  *
1276  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1277  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1278  * usually not supported.
1279  *
1280  * The following commands are currently not supported:
1281  *
1282  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1283  * MT_ST_WRITE_THRESHOLD.
1284  */
1285 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1286 {
1287         idetape_tape_t *tape = drive->driver_data;
1288         struct gendisk *disk = tape->disk;
1289         struct ide_atapi_pc pc;
1290         int i, retval;
1291
1292         debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
1293                         mt_op, mt_count);
1294
1295         switch (mt_op) {
1296         case MTFSF:
1297         case MTFSFM:
1298         case MTBSF:
1299         case MTBSFM:
1300                 if (!mt_count)
1301                         return 0;
1302                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1303         default:
1304                 break;
1305         }
1306
1307         switch (mt_op) {
1308         case MTWEOF:
1309                 if (tape->write_prot)
1310                         return -EACCES;
1311                 ide_tape_discard_merge_buffer(drive, 1);
1312                 for (i = 0; i < mt_count; i++) {
1313                         retval = idetape_write_filemark(drive);
1314                         if (retval)
1315                                 return retval;
1316                 }
1317                 return 0;
1318         case MTREW:
1319                 ide_tape_discard_merge_buffer(drive, 0);
1320                 if (idetape_rewind_tape(drive))
1321                         return -EIO;
1322                 return 0;
1323         case MTLOAD:
1324                 ide_tape_discard_merge_buffer(drive, 0);
1325                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1326         case MTUNLOAD:
1327         case MTOFFL:
1328                 /*
1329                  * If door is locked, attempt to unlock before
1330                  * attempting to eject.
1331                  */
1332                 if (tape->door_locked) {
1333                         if (!ide_set_media_lock(drive, disk, 0))
1334                                 tape->door_locked = DOOR_UNLOCKED;
1335                 }
1336                 ide_tape_discard_merge_buffer(drive, 0);
1337                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1338                 if (!retval)
1339                         clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1340                 return retval;
1341         case MTNOP:
1342                 ide_tape_discard_merge_buffer(drive, 0);
1343                 return idetape_flush_tape_buffers(drive);
1344         case MTRETEN:
1345                 ide_tape_discard_merge_buffer(drive, 0);
1346                 return ide_do_start_stop(drive, disk,
1347                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1348         case MTEOM:
1349                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1350                 return ide_queue_pc_tail(drive, disk, &pc);
1351         case MTERASE:
1352                 (void)idetape_rewind_tape(drive);
1353                 idetape_create_erase_cmd(&pc);
1354                 return ide_queue_pc_tail(drive, disk, &pc);
1355         case MTSETBLK:
1356                 if (mt_count) {
1357                         if (mt_count < tape->blk_size ||
1358                             mt_count % tape->blk_size)
1359                                 return -EIO;
1360                         tape->user_bs_factor = mt_count / tape->blk_size;
1361                         clear_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1362                 } else
1363                         set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1364                 return 0;
1365         case MTSEEK:
1366                 ide_tape_discard_merge_buffer(drive, 0);
1367                 return idetape_position_tape(drive,
1368                         mt_count * tape->user_bs_factor, tape->partition, 0);
1369         case MTSETPART:
1370                 ide_tape_discard_merge_buffer(drive, 0);
1371                 return idetape_position_tape(drive, 0, mt_count, 0);
1372         case MTFSR:
1373         case MTBSR:
1374         case MTLOCK:
1375                 retval = ide_set_media_lock(drive, disk, 1);
1376                 if (retval)
1377                         return retval;
1378                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1379                 return 0;
1380         case MTUNLOCK:
1381                 retval = ide_set_media_lock(drive, disk, 0);
1382                 if (retval)
1383                         return retval;
1384                 tape->door_locked = DOOR_UNLOCKED;
1385                 return 0;
1386         default:
1387                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1388                                 mt_op);
1389                 return -EIO;
1390         }
1391 }
1392
1393 /*
1394  * Our character device ioctls. General mtio.h magnetic io commands are
1395  * supported here, and not in the corresponding block interface. Our own
1396  * ide-tape ioctls are supported on both interfaces.
1397  */
1398 static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
1399                                 unsigned int cmd, unsigned long arg)
1400 {
1401         struct ide_tape_obj *tape = file->private_data;
1402         ide_drive_t *drive = tape->drive;
1403         struct mtop mtop;
1404         struct mtget mtget;
1405         struct mtpos mtpos;
1406         int block_offset = 0, position = tape->first_frame;
1407         void __user *argp = (void __user *)arg;
1408
1409         debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
1410
1411         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1412                 ide_tape_flush_merge_buffer(drive);
1413                 idetape_flush_tape_buffers(drive);
1414         }
1415         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1416                 block_offset = tape->valid /
1417                         (tape->blk_size * tape->user_bs_factor);
1418                 position = idetape_read_position(drive);
1419                 if (position < 0)
1420                         return -EIO;
1421         }
1422         switch (cmd) {
1423         case MTIOCTOP:
1424                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1425                         return -EFAULT;
1426                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1427         case MTIOCGET:
1428                 memset(&mtget, 0, sizeof(struct mtget));
1429                 mtget.mt_type = MT_ISSCSI2;
1430                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1431                 mtget.mt_dsreg =
1432                         ((tape->blk_size * tape->user_bs_factor)
1433                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1434
1435                 if (tape->drv_write_prot)
1436                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1437
1438                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1439                         return -EFAULT;
1440                 return 0;
1441         case MTIOCPOS:
1442                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1443                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1444                         return -EFAULT;
1445                 return 0;
1446         default:
1447                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1448                         ide_tape_discard_merge_buffer(drive, 1);
1449                 return idetape_blkdev_ioctl(drive, cmd, arg);
1450         }
1451 }
1452
1453 /*
1454  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1455  * block size with the reported value.
1456  */
1457 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1458 {
1459         idetape_tape_t *tape = drive->driver_data;
1460         struct ide_atapi_pc pc;
1461
1462         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1463         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1464                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1465                 if (tape->blk_size == 0) {
1466                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1467                                             "block size, assuming 32k\n");
1468                         tape->blk_size = 32768;
1469                 }
1470                 return;
1471         }
1472         tape->blk_size = (pc.buf[4 + 5] << 16) +
1473                                 (pc.buf[4 + 6] << 8)  +
1474                                  pc.buf[4 + 7];
1475         tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7;
1476 }
1477
1478 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1479 {
1480         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1481         ide_drive_t *drive;
1482         idetape_tape_t *tape;
1483         int retval;
1484
1485         if (i >= MAX_HWIFS * MAX_DRIVES)
1486                 return -ENXIO;
1487
1488         lock_kernel();
1489         tape = ide_tape_chrdev_get(i);
1490         if (!tape) {
1491                 unlock_kernel();
1492                 return -ENXIO;
1493         }
1494
1495         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1496
1497         /*
1498          * We really want to do nonseekable_open(inode, filp); here, but some
1499          * versions of tar incorrectly call lseek on tapes and bail out if that
1500          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1501          */
1502         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1503
1504         drive = tape->drive;
1505
1506         filp->private_data = tape;
1507
1508         if (test_and_set_bit(IDE_AFLAG_BUSY, &drive->atapi_flags)) {
1509                 retval = -EBUSY;
1510                 goto out_put_tape;
1511         }
1512
1513         retval = idetape_wait_ready(drive, 60 * HZ);
1514         if (retval) {
1515                 clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1516                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1517                 goto out_put_tape;
1518         }
1519
1520         idetape_read_position(drive);
1521         if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags))
1522                 (void)idetape_rewind_tape(drive);
1523
1524         /* Read block size and write protect status from drive. */
1525         ide_tape_get_bsize_from_bdesc(drive);
1526
1527         /* Set write protect flag if device is opened as read-only. */
1528         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1529                 tape->write_prot = 1;
1530         else
1531                 tape->write_prot = tape->drv_write_prot;
1532
1533         /* Make sure drive isn't write protected if user wants to write. */
1534         if (tape->write_prot) {
1535                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1536                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1537                         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1538                         retval = -EROFS;
1539                         goto out_put_tape;
1540                 }
1541         }
1542
1543         /* Lock the tape drive door so user can't eject. */
1544         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1545                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1546                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1547                                 tape->door_locked = DOOR_LOCKED;
1548                 }
1549         }
1550         unlock_kernel();
1551         return 0;
1552
1553 out_put_tape:
1554         ide_tape_put(tape);
1555         unlock_kernel();
1556         return retval;
1557 }
1558
1559 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1560 {
1561         idetape_tape_t *tape = drive->driver_data;
1562
1563         ide_tape_flush_merge_buffer(drive);
1564         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1565         if (tape->buf != NULL) {
1566                 idetape_pad_zeros(drive, tape->blk_size *
1567                                 (tape->user_bs_factor - 1));
1568                 kfree(tape->buf);
1569                 tape->buf = NULL;
1570         }
1571         idetape_write_filemark(drive);
1572         idetape_flush_tape_buffers(drive);
1573         idetape_flush_tape_buffers(drive);
1574 }
1575
1576 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1577 {
1578         struct ide_tape_obj *tape = filp->private_data;
1579         ide_drive_t *drive = tape->drive;
1580         unsigned int minor = iminor(inode);
1581
1582         lock_kernel();
1583         tape = drive->driver_data;
1584
1585         debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1586
1587         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1588                 idetape_write_release(drive, minor);
1589         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1590                 if (minor < 128)
1591                         ide_tape_discard_merge_buffer(drive, 1);
1592         }
1593
1594         if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags))
1595                 (void) idetape_rewind_tape(drive);
1596         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1597                 if (tape->door_locked == DOOR_LOCKED) {
1598                         if (!ide_set_media_lock(drive, tape->disk, 0))
1599                                 tape->door_locked = DOOR_UNLOCKED;
1600                 }
1601         }
1602         clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1603         ide_tape_put(tape);
1604         unlock_kernel();
1605         return 0;
1606 }
1607
1608 static void idetape_get_inquiry_results(ide_drive_t *drive)
1609 {
1610         idetape_tape_t *tape = drive->driver_data;
1611         struct ide_atapi_pc pc;
1612         u8 pc_buf[256];
1613         char fw_rev[4], vendor_id[8], product_id[16];
1614
1615         idetape_create_inquiry_cmd(&pc);
1616         pc.buf = &pc_buf[0];
1617         pc.buf_size = sizeof(pc_buf);
1618
1619         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1620                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1621                                 tape->name);
1622                 return;
1623         }
1624         memcpy(vendor_id, &pc.buf[8], 8);
1625         memcpy(product_id, &pc.buf[16], 16);
1626         memcpy(fw_rev, &pc.buf[32], 4);
1627
1628         ide_fixstring(vendor_id, 8, 0);
1629         ide_fixstring(product_id, 16, 0);
1630         ide_fixstring(fw_rev, 4, 0);
1631
1632         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1633                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1634 }
1635
1636 /*
1637  * Ask the tape about its various parameters. In particular, we will adjust our
1638  * data transfer buffer size to the recommended value as returned by the tape.
1639  */
1640 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1641 {
1642         idetape_tape_t *tape = drive->driver_data;
1643         struct ide_atapi_pc pc;
1644         u8 *caps;
1645         u8 speed, max_speed;
1646
1647         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1648         if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1649                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1650                                 " some default values\n");
1651                 tape->blk_size = 512;
1652                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1653                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1654                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1655                 return;
1656         }
1657         caps = pc.buf + 4 + pc.buf[3];
1658
1659         /* convert to host order and save for later use */
1660         speed = be16_to_cpup((__be16 *)&caps[14]);
1661         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1662
1663         *(u16 *)&caps[8] = max_speed;
1664         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1665         *(u16 *)&caps[14] = speed;
1666         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1667
1668         if (!speed) {
1669                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1670                                 "(assuming 650KB/sec)\n", drive->name);
1671                 *(u16 *)&caps[14] = 650;
1672         }
1673         if (!max_speed) {
1674                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1675                                 "(assuming 650KB/sec)\n", drive->name);
1676                 *(u16 *)&caps[8] = 650;
1677         }
1678
1679         memcpy(&tape->caps, caps, 20);
1680
1681         /* device lacks locking support according to capabilities page */
1682         if ((caps[6] & 1) == 0)
1683                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1684
1685         if (caps[7] & 0x02)
1686                 tape->blk_size = 512;
1687         else if (caps[7] & 0x04)
1688                 tape->blk_size = 1024;
1689 }
1690
1691 #ifdef CONFIG_IDE_PROC_FS
1692 #define ide_tape_devset_get(name, field) \
1693 static int get_##name(ide_drive_t *drive) \
1694 { \
1695         idetape_tape_t *tape = drive->driver_data; \
1696         return tape->field; \
1697 }
1698
1699 #define ide_tape_devset_set(name, field) \
1700 static int set_##name(ide_drive_t *drive, int arg) \
1701 { \
1702         idetape_tape_t *tape = drive->driver_data; \
1703         tape->field = arg; \
1704         return 0; \
1705 }
1706
1707 #define ide_tape_devset_rw_field(_name, _field) \
1708 ide_tape_devset_get(_name, _field) \
1709 ide_tape_devset_set(_name, _field) \
1710 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1711
1712 #define ide_tape_devset_r_field(_name, _field) \
1713 ide_tape_devset_get(_name, _field) \
1714 IDE_DEVSET(_name, 0, get_##_name, NULL)
1715
1716 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1717 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1718 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1719 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1720
1721 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1722
1723 ide_tape_devset_rw_field(debug_mask, debug_mask);
1724 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1725
1726 ide_tape_devset_r_field(avg_speed, avg_speed);
1727 ide_tape_devset_r_field(speed, caps[14]);
1728 ide_tape_devset_r_field(buffer, caps[16]);
1729 ide_tape_devset_r_field(buffer_size, buffer_size);
1730
1731 static const struct ide_proc_devset idetape_settings[] = {
1732         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1733         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1734         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1735         __IDE_PROC_DEVSET(debug_mask,   0, 0xffff, NULL, NULL),
1736         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1737         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1738         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1739                                         mulf_tdsc, divf_tdsc),
1740         { NULL },
1741 };
1742 #endif
1743
1744 /*
1745  * The function below is called to:
1746  *
1747  * 1. Initialize our various state variables.
1748  * 2. Ask the tape for its capabilities.
1749  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1750  * is chosen based on the recommendation which we received in step 2.
1751  *
1752  * Note that at this point ide.c already assigned us an irq, so that we can
1753  * queue requests here and wait for their completion.
1754  */
1755 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1756 {
1757         unsigned long t;
1758         int speed;
1759         int buffer_size;
1760         u16 *ctl = (u16 *)&tape->caps[12];
1761
1762         drive->pc_callback       = ide_tape_callback;
1763
1764         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1765
1766         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1767                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1768                                  tape->name);
1769                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1770         }
1771
1772         /* Seagate Travan drives do not support DSC overlap. */
1773         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1774                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1775
1776         tape->minor = minor;
1777         tape->name[0] = 'h';
1778         tape->name[1] = 't';
1779         tape->name[2] = '0' + minor;
1780         tape->chrdev_dir = IDETAPE_DIR_NONE;
1781
1782         idetape_get_inquiry_results(drive);
1783         idetape_get_mode_sense_results(drive);
1784         ide_tape_get_bsize_from_bdesc(drive);
1785         tape->user_bs_factor = 1;
1786         tape->buffer_size = *ctl * tape->blk_size;
1787         while (tape->buffer_size > 0xffff) {
1788                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1789                 *ctl /= 2;
1790                 tape->buffer_size = *ctl * tape->blk_size;
1791         }
1792         buffer_size = tape->buffer_size;
1793
1794         /* select the "best" DSC read/write polling freq */
1795         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1796
1797         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1798
1799         /*
1800          * Ensure that the number we got makes sense; limit it within
1801          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1802          */
1803         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1804                                          IDETAPE_DSC_RW_MAX);
1805         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1806                 "%lums tDSC%s\n",
1807                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1808                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1809                 tape->buffer_size / 1024,
1810                 tape->best_dsc_rw_freq * 1000 / HZ,
1811                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1812
1813         ide_proc_register_driver(drive, tape->driver);
1814 }
1815
1816 static void ide_tape_remove(ide_drive_t *drive)
1817 {
1818         idetape_tape_t *tape = drive->driver_data;
1819
1820         ide_proc_unregister_driver(drive, tape->driver);
1821         device_del(&tape->dev);
1822         ide_unregister_region(tape->disk);
1823
1824         mutex_lock(&idetape_ref_mutex);
1825         put_device(&tape->dev);
1826         mutex_unlock(&idetape_ref_mutex);
1827 }
1828
1829 static void ide_tape_release(struct device *dev)
1830 {
1831         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1832         ide_drive_t *drive = tape->drive;
1833         struct gendisk *g = tape->disk;
1834
1835         BUG_ON(tape->valid);
1836
1837         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1838         drive->driver_data = NULL;
1839         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1840         device_destroy(idetape_sysfs_class,
1841                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1842         idetape_devs[tape->minor] = NULL;
1843         g->private_data = NULL;
1844         put_disk(g);
1845         kfree(tape);
1846 }
1847
1848 #ifdef CONFIG_IDE_PROC_FS
1849 static int proc_idetape_read_name
1850         (char *page, char **start, off_t off, int count, int *eof, void *data)
1851 {
1852         ide_drive_t     *drive = (ide_drive_t *) data;
1853         idetape_tape_t  *tape = drive->driver_data;
1854         char            *out = page;
1855         int             len;
1856
1857         len = sprintf(out, "%s\n", tape->name);
1858         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
1859 }
1860
1861 static ide_proc_entry_t idetape_proc[] = {
1862         { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
1863         { "name",       S_IFREG|S_IRUGO,        proc_idetape_read_name, NULL },
1864         { NULL, 0, NULL, NULL }
1865 };
1866
1867 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1868 {
1869         return idetape_proc;
1870 }
1871
1872 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1873 {
1874         return idetape_settings;
1875 }
1876 #endif
1877
1878 static int ide_tape_probe(ide_drive_t *);
1879
1880 static struct ide_driver idetape_driver = {
1881         .gen_driver = {
1882                 .owner          = THIS_MODULE,
1883                 .name           = "ide-tape",
1884                 .bus            = &ide_bus_type,
1885         },
1886         .probe                  = ide_tape_probe,
1887         .remove                 = ide_tape_remove,
1888         .version                = IDETAPE_VERSION,
1889         .do_request             = idetape_do_request,
1890 #ifdef CONFIG_IDE_PROC_FS
1891         .proc_entries           = ide_tape_proc_entries,
1892         .proc_devsets           = ide_tape_proc_devsets,
1893 #endif
1894 };
1895
1896 /* Our character device supporting functions, passed to register_chrdev. */
1897 static const struct file_operations idetape_fops = {
1898         .owner          = THIS_MODULE,
1899         .read           = idetape_chrdev_read,
1900         .write          = idetape_chrdev_write,
1901         .ioctl          = idetape_chrdev_ioctl,
1902         .open           = idetape_chrdev_open,
1903         .release        = idetape_chrdev_release,
1904 };
1905
1906 static int idetape_open(struct block_device *bdev, fmode_t mode)
1907 {
1908         struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk);
1909
1910         if (!tape)
1911                 return -ENXIO;
1912
1913         return 0;
1914 }
1915
1916 static int idetape_release(struct gendisk *disk, fmode_t mode)
1917 {
1918         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1919
1920         ide_tape_put(tape);
1921         return 0;
1922 }
1923
1924 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1925                         unsigned int cmd, unsigned long arg)
1926 {
1927         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1928         ide_drive_t *drive = tape->drive;
1929         int err = generic_ide_ioctl(drive, bdev, cmd, arg);
1930         if (err == -EINVAL)
1931                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1932         return err;
1933 }
1934
1935 static struct block_device_operations idetape_block_ops = {
1936         .owner          = THIS_MODULE,
1937         .open           = idetape_open,
1938         .release        = idetape_release,
1939         .locked_ioctl   = idetape_ioctl,
1940 };
1941
1942 static int ide_tape_probe(ide_drive_t *drive)
1943 {
1944         idetape_tape_t *tape;
1945         struct gendisk *g;
1946         int minor;
1947
1948         if (!strstr("ide-tape", drive->driver_req))
1949                 goto failed;
1950
1951         if (drive->media != ide_tape)
1952                 goto failed;
1953
1954         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1955             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1956                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1957                                 " the driver\n", drive->name);
1958                 goto failed;
1959         }
1960         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1961         if (tape == NULL) {
1962                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1963                                 drive->name);
1964                 goto failed;
1965         }
1966
1967         g = alloc_disk(1 << PARTN_BITS);
1968         if (!g)
1969                 goto out_free_tape;
1970
1971         ide_init_disk(g, drive);
1972
1973         tape->dev.parent = &drive->gendev;
1974         tape->dev.release = ide_tape_release;
1975         dev_set_name(&tape->dev, dev_name(&drive->gendev));
1976
1977         if (device_register(&tape->dev))
1978                 goto out_free_disk;
1979
1980         tape->drive = drive;
1981         tape->driver = &idetape_driver;
1982         tape->disk = g;
1983
1984         g->private_data = &tape->driver;
1985
1986         drive->driver_data = tape;
1987
1988         mutex_lock(&idetape_ref_mutex);
1989         for (minor = 0; idetape_devs[minor]; minor++)
1990                 ;
1991         idetape_devs[minor] = tape;
1992         mutex_unlock(&idetape_ref_mutex);
1993
1994         idetape_setup(drive, tape, minor);
1995
1996         device_create(idetape_sysfs_class, &drive->gendev,
1997                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
1998         device_create(idetape_sysfs_class, &drive->gendev,
1999                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2000                       "n%s", tape->name);
2001
2002         g->fops = &idetape_block_ops;
2003         ide_register_region(g);
2004
2005         return 0;
2006
2007 out_free_disk:
2008         put_disk(g);
2009 out_free_tape:
2010         kfree(tape);
2011 failed:
2012         return -ENODEV;
2013 }
2014
2015 static void __exit idetape_exit(void)
2016 {
2017         driver_unregister(&idetape_driver.gen_driver);
2018         class_destroy(idetape_sysfs_class);
2019         unregister_chrdev(IDETAPE_MAJOR, "ht");
2020 }
2021
2022 static int __init idetape_init(void)
2023 {
2024         int error = 1;
2025         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2026         if (IS_ERR(idetape_sysfs_class)) {
2027                 idetape_sysfs_class = NULL;
2028                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2029                 error = -EBUSY;
2030                 goto out;
2031         }
2032
2033         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2034                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2035                                 " interface\n");
2036                 error = -EBUSY;
2037                 goto out_free_class;
2038         }
2039
2040         error = driver_register(&idetape_driver.gen_driver);
2041         if (error)
2042                 goto out_free_driver;
2043
2044         return 0;
2045
2046 out_free_driver:
2047         driver_unregister(&idetape_driver.gen_driver);
2048 out_free_class:
2049         class_destroy(idetape_sysfs_class);
2050 out:
2051         return error;
2052 }
2053
2054 MODULE_ALIAS("ide:*m-tape*");
2055 module_init(idetape_init);
2056 module_exit(idetape_exit);
2057 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2058 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2059 MODULE_LICENSE("GPL");