linux/drivers/ide/ide-tape.c
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   1/*
   2 * IDE ATAPI streaming tape driver.
   3 *
   4 * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
   5 * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
   6 *
   7 * This driver was constructed as a student project in the software laboratory
   8 * of the faculty of electrical engineering in the Technion - Israel's
   9 * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
  10 *
  11 * It is hereby placed under the terms of the GNU general public license.
  12 * (See linux/COPYING).
  13 *
  14 * For a historical changelog see
  15 * Documentation/ide/ChangeLog.ide-tape.1995-2002
  16 */
  17
  18#define DRV_NAME "ide-tape"
  19
  20#define IDETAPE_VERSION "1.20"
  21
  22#include <linux/module.h>
  23#include <linux/types.h>
  24#include <linux/string.h>
  25#include <linux/kernel.h>
  26#include <linux/delay.h>
  27#include <linux/timer.h>
  28#include <linux/mm.h>
  29#include <linux/interrupt.h>
  30#include <linux/jiffies.h>
  31#include <linux/major.h>
  32#include <linux/errno.h>
  33#include <linux/genhd.h>
  34#include <linux/seq_file.h>
  35#include <linux/slab.h>
  36#include <linux/pci.h>
  37#include <linux/ide.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/uaccess.h>
  45#include <linux/io.h>
  46#include <asm/unaligned.h>
  47#include <linux/mtio.h>
  48
  49/* define to see debug info */
  50#undef IDETAPE_DEBUG_LOG
  51
  52#ifdef IDETAPE_DEBUG_LOG
  53#define ide_debug_log(lvl, fmt, args...) __ide_debug_log(lvl, fmt, ## args)
  54#else
  55#define ide_debug_log(lvl, fmt, args...) do {} while (0)
  56#endif
  57
  58/**************************** Tunable parameters *****************************/
  59/*
  60 * After each failed packet command we issue a request sense command and retry
  61 * the packet command IDETAPE_MAX_PC_RETRIES times.
  62 *
  63 * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
  64 */
  65#define IDETAPE_MAX_PC_RETRIES          3
  66
  67/*
  68 * The following parameter is used to select the point in the internal tape fifo
  69 * in which we will start to refill the buffer. Decreasing the following
  70 * parameter will improve the system's latency and interactive response, while
  71 * using a high value might improve system throughput.
  72 */
  73#define IDETAPE_FIFO_THRESHOLD          2
  74
  75/*
  76 * DSC polling parameters.
  77 *
  78 * Polling for DSC (a single bit in the status register) is a very important
  79 * function in ide-tape. There are two cases in which we poll for DSC:
  80 *
  81 * 1. Before a read/write packet command, to ensure that we can transfer data
  82 * from/to the tape's data buffers, without causing an actual media access.
  83 * In case the tape is not ready yet, we take out our request from the device
  84 * request queue, so that ide.c could service requests from the other device
  85 * on the same interface in the meantime.
  86 *
  87 * 2. After the successful initialization of a "media access packet command",
  88 * which is a command that can take a long time to complete (the interval can
  89 * range from several seconds to even an hour). Again, we postpone our request
  90 * in the middle to free the bus for the other device. The polling frequency
  91 * here should be lower than the read/write frequency since those media access
  92 * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
  93 * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
  94 * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
  95 *
  96 * We also set a timeout for the timer, in case something goes wrong. The
  97 * timeout should be longer then the maximum execution time of a tape operation.
  98 */
  99
 100/* DSC timings. */
 101#define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 102#define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 103#define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 104#define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 105#define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 106#define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 107#define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 108
 109/*************************** End of tunable parameters ***********************/
 110
 111/* tape directions */
 112enum {
 113        IDETAPE_DIR_NONE  = (1 << 0),
 114        IDETAPE_DIR_READ  = (1 << 1),
 115        IDETAPE_DIR_WRITE = (1 << 2),
 116};
 117
 118/* Tape door status */
 119#define DOOR_UNLOCKED                   0
 120#define DOOR_LOCKED                     1
 121#define DOOR_EXPLICITLY_LOCKED          2
 122
 123/* Some defines for the SPACE command */
 124#define IDETAPE_SPACE_OVER_FILEMARK     1
 125#define IDETAPE_SPACE_TO_EOD            3
 126
 127/* Some defines for the LOAD UNLOAD command */
 128#define IDETAPE_LU_LOAD_MASK            1
 129#define IDETAPE_LU_RETENSION_MASK       2
 130#define IDETAPE_LU_EOT_MASK             4
 131
 132/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
 133#define IDETAPE_BLOCK_DESCRIPTOR        0
 134#define IDETAPE_CAPABILITIES_PAGE       0x2a
 135
 136/*
 137 * Most of our global data which we need to save even as we leave the driver due
 138 * to an interrupt or a timer event is stored in the struct defined below.
 139 */
 140typedef struct ide_tape_obj {
 141        ide_drive_t             *drive;
 142        struct ide_driver       *driver;
 143        struct gendisk          *disk;
 144        struct device           dev;
 145
 146        /* used by REQ_IDETAPE_{READ,WRITE} requests */
 147        struct ide_atapi_pc queued_pc;
 148
 149        /*
 150         * DSC polling variables.
 151         *
 152         * While polling for DSC we use postponed_rq to postpone the current
 153         * request so that ide.c will be able to service pending requests on the
 154         * other device. Note that at most we will have only one DSC (usually
 155         * data transfer) request in the device request queue.
 156         */
 157        bool postponed_rq;
 158
 159        /* The time in which we started polling for DSC */
 160        unsigned long dsc_polling_start;
 161        /* Timer used to poll for dsc */
 162        struct timer_list dsc_timer;
 163        /* Read/Write dsc polling frequency */
 164        unsigned long best_dsc_rw_freq;
 165        unsigned long dsc_poll_freq;
 166        unsigned long dsc_timeout;
 167
 168        /* Read position information */
 169        u8 partition;
 170        /* Current block */
 171        unsigned int first_frame;
 172
 173        /* Last error information */
 174        u8 sense_key, asc, ascq;
 175
 176        /* Character device operation */
 177        unsigned int minor;
 178        /* device name */
 179        char name[4];
 180        /* Current character device data transfer direction */
 181        u8 chrdev_dir;
 182
 183        /* tape block size, usually 512 or 1024 bytes */
 184        unsigned short blk_size;
 185        int user_bs_factor;
 186
 187        /* Copy of the tape's Capabilities and Mechanical Page */
 188        u8 caps[20];
 189
 190        /*
 191         * Active data transfer request parameters.
 192         *
 193         * At most, there is only one ide-tape originated data transfer request
 194         * in the device request queue. This allows ide.c to easily service
 195         * requests from the other device when we postpone our active request.
 196         */
 197
 198        /* Data buffer size chosen based on the tape's recommendation */
 199        int buffer_size;
 200        /* Staging buffer of buffer_size bytes */
 201        void *buf;
 202        /* The read/write cursor */
 203        void *cur;
 204        /* The number of valid bytes in buf */
 205        size_t valid;
 206
 207        /* Measures average tape speed */
 208        unsigned long avg_time;
 209        int avg_size;
 210        int avg_speed;
 211
 212        /* the door is currently locked */
 213        int door_locked;
 214        /* the tape hardware is write protected */
 215        char drv_write_prot;
 216        /* the tape is write protected (hardware or opened as read-only) */
 217        char write_prot;
 218} idetape_tape_t;
 219
 220static DEFINE_MUTEX(ide_tape_mutex);
 221static DEFINE_MUTEX(idetape_ref_mutex);
 222
 223static DEFINE_MUTEX(idetape_chrdev_mutex);
 224
 225static struct class *idetape_sysfs_class;
 226
 227static void ide_tape_release(struct device *);
 228
 229static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
 230
 231static struct ide_tape_obj *ide_tape_get(struct gendisk *disk, bool cdev,
 232                                         unsigned int i)
 233{
 234        struct ide_tape_obj *tape = NULL;
 235
 236        mutex_lock(&idetape_ref_mutex);
 237
 238        if (cdev)
 239                tape = idetape_devs[i];
 240        else
 241                tape = ide_drv_g(disk, ide_tape_obj);
 242
 243        if (tape) {
 244                if (ide_device_get(tape->drive))
 245                        tape = NULL;
 246                else
 247                        get_device(&tape->dev);
 248        }
 249
 250        mutex_unlock(&idetape_ref_mutex);
 251        return tape;
 252}
 253
 254static void ide_tape_put(struct ide_tape_obj *tape)
 255{
 256        ide_drive_t *drive = tape->drive;
 257
 258        mutex_lock(&idetape_ref_mutex);
 259        put_device(&tape->dev);
 260        ide_device_put(drive);
 261        mutex_unlock(&idetape_ref_mutex);
 262}
 263
 264/*
 265 * called on each failed packet command retry to analyze the request sense. We
 266 * currently do not utilize this information.
 267 */
 268static void idetape_analyze_error(ide_drive_t *drive)
 269{
 270        idetape_tape_t *tape = drive->driver_data;
 271        struct ide_atapi_pc *pc = drive->failed_pc;
 272        struct request *rq = drive->hwif->rq;
 273        u8 *sense = bio_data(rq->bio);
 274
 275        tape->sense_key = sense[2] & 0xF;
 276        tape->asc       = sense[12];
 277        tape->ascq      = sense[13];
 278
 279        ide_debug_log(IDE_DBG_FUNC,
 280                      "cmd: 0x%x, sense key = %x, asc = %x, ascq = %x",
 281                      rq->cmd[0], tape->sense_key, tape->asc, tape->ascq);
 282
 283        /* correct remaining bytes to transfer */
 284        if (pc->flags & PC_FLAG_DMA_ERROR)
 285                rq->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
 286
 287        /*
 288         * If error was the result of a zero-length read or write command,
 289         * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
 290         * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
 291         */
 292        if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
 293            /* length == 0 */
 294            && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
 295                if (tape->sense_key == 5) {
 296                        /* don't report an error, everything's ok */
 297                        pc->error = 0;
 298                        /* don't retry read/write */
 299                        pc->flags |= PC_FLAG_ABORT;
 300                }
 301        }
 302        if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
 303                pc->error = IDE_DRV_ERROR_FILEMARK;
 304                pc->flags |= PC_FLAG_ABORT;
 305        }
 306        if (pc->c[0] == WRITE_6) {
 307                if ((sense[2] & 0x40) || (tape->sense_key == 0xd
 308                     && tape->asc == 0x0 && tape->ascq == 0x2)) {
 309                        pc->error = IDE_DRV_ERROR_EOD;
 310                        pc->flags |= PC_FLAG_ABORT;
 311                }
 312        }
 313        if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 314                if (tape->sense_key == 8) {
 315                        pc->error = IDE_DRV_ERROR_EOD;
 316                        pc->flags |= PC_FLAG_ABORT;
 317                }
 318                if (!(pc->flags & PC_FLAG_ABORT) &&
 319                    (blk_rq_bytes(rq) - rq->resid_len))
 320                        pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
 321        }
 322}
 323
 324static void ide_tape_handle_dsc(ide_drive_t *);
 325
 326static int ide_tape_callback(ide_drive_t *drive, int dsc)
 327{
 328        idetape_tape_t *tape = drive->driver_data;
 329        struct ide_atapi_pc *pc = drive->pc;
 330        struct request *rq = drive->hwif->rq;
 331        int uptodate = pc->error ? 0 : 1;
 332        int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 333
 334        ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc: %d, err: %d", rq->cmd[0],
 335                      dsc, err);
 336
 337        if (dsc)
 338                ide_tape_handle_dsc(drive);
 339
 340        if (drive->failed_pc == pc)
 341                drive->failed_pc = NULL;
 342
 343        if (pc->c[0] == REQUEST_SENSE) {
 344                if (uptodate)
 345                        idetape_analyze_error(drive);
 346                else
 347                        printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
 348                                        "itself - Aborting request!\n");
 349        } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
 350                unsigned int blocks =
 351                        (blk_rq_bytes(rq) - rq->resid_len) / tape->blk_size;
 352
 353                tape->avg_size += blocks * tape->blk_size;
 354
 355                if (time_after_eq(jiffies, tape->avg_time + HZ)) {
 356                        tape->avg_speed = tape->avg_size * HZ /
 357                                (jiffies - tape->avg_time) / 1024;
 358                        tape->avg_size = 0;
 359                        tape->avg_time = jiffies;
 360                }
 361
 362                tape->first_frame += blocks;
 363
 364                if (pc->error) {
 365                        uptodate = 0;
 366                        err = pc->error;
 367                }
 368        }
 369        rq->errors = err;
 370
 371        return uptodate;
 372}
 373
 374/*
 375 * Postpone the current request so that ide.c will be able to service requests
 376 * from another device on the same port while we are polling for DSC.
 377 */
 378static void ide_tape_stall_queue(ide_drive_t *drive)
 379{
 380        idetape_tape_t *tape = drive->driver_data;
 381
 382        ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc_poll_freq: %lu",
 383                      drive->hwif->rq->cmd[0], tape->dsc_poll_freq);
 384
 385        tape->postponed_rq = true;
 386
 387        ide_stall_queue(drive, tape->dsc_poll_freq);
 388}
 389
 390static void ide_tape_handle_dsc(ide_drive_t *drive)
 391{
 392        idetape_tape_t *tape = drive->driver_data;
 393
 394        /* Media access command */
 395        tape->dsc_polling_start = jiffies;
 396        tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
 397        tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
 398        /* Allow ide.c to handle other requests */
 399        ide_tape_stall_queue(drive);
 400}
 401
 402/*
 403 * Packet Command Interface
 404 *
 405 * The current Packet Command is available in drive->pc, and will not change
 406 * until we finish handling it. Each packet command is associated with a
 407 * callback function that will be called when the command is finished.
 408 *
 409 * The handling will be done in three stages:
 410 *
 411 * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
 412 * the interrupt handler to ide_pc_intr.
 413 *
 414 * 2. On each interrupt, ide_pc_intr will be called. This step will be
 415 * repeated until the device signals us that no more interrupts will be issued.
 416 *
 417 * 3. ATAPI Tape media access commands have immediate status with a delayed
 418 * process. In case of a successful initiation of a media access packet command,
 419 * the DSC bit will be set when the actual execution of the command is finished.
 420 * Since the tape drive will not issue an interrupt, we have to poll for this
 421 * event. In this case, we define the request as "low priority request" by
 422 * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 423 * exit the driver.
 424 *
 425 * ide.c will then give higher priority to requests which originate from the
 426 * other device, until will change rq_status to RQ_ACTIVE.
 427 *
 428 * 4. When the packet command is finished, it will be checked for errors.
 429 *
 430 * 5. In case an error was found, we queue a request sense packet command in
 431 * front of the request queue and retry the operation up to
 432 * IDETAPE_MAX_PC_RETRIES times.
 433 *
 434 * 6. In case no error was found, or we decided to give up and not to retry
 435 * again, the callback function will be called and then we will handle the next
 436 * request.
 437 */
 438
 439static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 440                                         struct ide_cmd *cmd,
 441                                         struct ide_atapi_pc *pc)
 442{
 443        idetape_tape_t *tape = drive->driver_data;
 444        struct request *rq = drive->hwif->rq;
 445
 446        if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
 447                drive->failed_pc = pc;
 448
 449        /* Set the current packet command */
 450        drive->pc = pc;
 451
 452        if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
 453                (pc->flags & PC_FLAG_ABORT)) {
 454
 455                /*
 456                 * We will "abort" retrying a packet command in case legitimate
 457                 * error code was received (crossing a filemark, or end of the
 458                 * media, for example).
 459                 */
 460                if (!(pc->flags & PC_FLAG_ABORT)) {
 461                        if (!(pc->c[0] == TEST_UNIT_READY &&
 462                              tape->sense_key == 2 && tape->asc == 4 &&
 463                             (tape->ascq == 1 || tape->ascq == 8))) {
 464                                printk(KERN_ERR "ide-tape: %s: I/O error, "
 465                                                "pc = %2x, key = %2x, "
 466                                                "asc = %2x, ascq = %2x\n",
 467                                                tape->name, pc->c[0],
 468                                                tape->sense_key, tape->asc,
 469                                                tape->ascq);
 470                        }
 471                        /* Giving up */
 472                        pc->error = IDE_DRV_ERROR_GENERAL;
 473                }
 474
 475                drive->failed_pc = NULL;
 476                drive->pc_callback(drive, 0);
 477                ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
 478                return ide_stopped;
 479        }
 480        ide_debug_log(IDE_DBG_SENSE, "retry #%d, cmd: 0x%02x", pc->retries,
 481                      pc->c[0]);
 482
 483        pc->retries++;
 484
 485        return ide_issue_pc(drive, cmd);
 486}
 487
 488/* A mode sense command is used to "sense" tape parameters. */
 489static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 490{
 491        ide_init_pc(pc);
 492        pc->c[0] = MODE_SENSE;
 493        if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
 494                /* DBD = 1 - Don't return block descriptors */
 495                pc->c[1] = 8;
 496        pc->c[2] = page_code;
 497        /*
 498         * Changed pc->c[3] to 0 (255 will at best return unused info).
 499         *
 500         * For SCSI this byte is defined as subpage instead of high byte
 501         * of length and some IDE drives seem to interpret it this way
 502         * and return an error when 255 is used.
 503         */
 504        pc->c[3] = 0;
 505        /* We will just discard data in that case */
 506        pc->c[4] = 255;
 507        if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
 508                pc->req_xfer = 12;
 509        else if (page_code == IDETAPE_CAPABILITIES_PAGE)
 510                pc->req_xfer = 24;
 511        else
 512                pc->req_xfer = 50;
 513}
 514
 515static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 516{
 517        ide_hwif_t *hwif = drive->hwif;
 518        idetape_tape_t *tape = drive->driver_data;
 519        struct ide_atapi_pc *pc = drive->pc;
 520        u8 stat;
 521
 522        stat = hwif->tp_ops->read_status(hwif);
 523
 524        if (stat & ATA_DSC) {
 525                if (stat & ATA_ERR) {
 526                        /* Error detected */
 527                        if (pc->c[0] != TEST_UNIT_READY)
 528                                printk(KERN_ERR "ide-tape: %s: I/O error, ",
 529                                                tape->name);
 530                        /* Retry operation */
 531                        ide_retry_pc(drive);
 532                        return ide_stopped;
 533                }
 534                pc->error = 0;
 535        } else {
 536                pc->error = IDE_DRV_ERROR_GENERAL;
 537                drive->failed_pc = NULL;
 538        }
 539        drive->pc_callback(drive, 0);
 540        return ide_stopped;
 541}
 542
 543static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
 544                                   struct ide_atapi_pc *pc, struct request *rq,
 545                                   u8 opcode)
 546{
 547        unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
 548
 549        ide_init_pc(pc);
 550        put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
 551        pc->c[1] = 1;
 552
 553        if (blk_rq_bytes(rq) == tape->buffer_size)
 554                pc->flags |= PC_FLAG_DMA_OK;
 555
 556        if (opcode == READ_6)
 557                pc->c[0] = READ_6;
 558        else if (opcode == WRITE_6) {
 559                pc->c[0] = WRITE_6;
 560                pc->flags |= PC_FLAG_WRITING;
 561        }
 562
 563        memcpy(rq->cmd, pc->c, 12);
 564}
 565
 566static ide_startstop_t idetape_do_request(ide_drive_t *drive,
 567                                          struct request *rq, sector_t block)
 568{
 569        ide_hwif_t *hwif = drive->hwif;
 570        idetape_tape_t *tape = drive->driver_data;
 571        struct ide_atapi_pc *pc = NULL;
 572        struct ide_cmd cmd;
 573        u8 stat;
 574
 575        ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, sector: %llu, nr_sectors: %u",
 576                      rq->cmd[0], (unsigned long long)blk_rq_pos(rq),
 577                      blk_rq_sectors(rq));
 578
 579        BUG_ON(!(rq->cmd_type == REQ_TYPE_SPECIAL ||
 580                 rq->cmd_type == REQ_TYPE_SENSE));
 581
 582        /* Retry a failed packet command */
 583        if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 584                pc = drive->failed_pc;
 585                goto out;
 586        }
 587
 588        /*
 589         * If the tape is still busy, postpone our request and service
 590         * the other device meanwhile.
 591         */
 592        stat = hwif->tp_ops->read_status(hwif);
 593
 594        if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 595            (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
 596                drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 597
 598        if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 599                drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 600                drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 601        }
 602
 603        if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
 604            !(stat & ATA_DSC)) {
 605                if (!tape->postponed_rq) {
 606                        tape->dsc_polling_start = jiffies;
 607                        tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 608                        tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 609                } else if (time_after(jiffies, tape->dsc_timeout)) {
 610                        printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 611                                tape->name);
 612                        if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 613                                idetape_media_access_finished(drive);
 614                                return ide_stopped;
 615                        } else {
 616                                return ide_do_reset(drive);
 617                        }
 618                } else if (time_after(jiffies,
 619                                        tape->dsc_polling_start +
 620                                        IDETAPE_DSC_MA_THRESHOLD))
 621                        tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 622                ide_tape_stall_queue(drive);
 623                return ide_stopped;
 624        } else {
 625                drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
 626                tape->postponed_rq = false;
 627        }
 628
 629        if (rq->cmd[13] & REQ_IDETAPE_READ) {
 630                pc = &tape->queued_pc;
 631                ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 632                goto out;
 633        }
 634        if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
 635                pc = &tape->queued_pc;
 636                ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 637                goto out;
 638        }
 639        if (rq->cmd[13] & REQ_IDETAPE_PC1) {
 640                pc = (struct ide_atapi_pc *)rq->special;
 641                rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
 642                rq->cmd[13] |= REQ_IDETAPE_PC2;
 643                goto out;
 644        }
 645        if (rq->cmd[13] & REQ_IDETAPE_PC2) {
 646                idetape_media_access_finished(drive);
 647                return ide_stopped;
 648        }
 649        BUG();
 650
 651out:
 652        /* prepare sense request for this command */
 653        ide_prep_sense(drive, rq);
 654
 655        memset(&cmd, 0, sizeof(cmd));
 656
 657        if (rq_data_dir(rq))
 658                cmd.tf_flags |= IDE_TFLAG_WRITE;
 659
 660        cmd.rq = rq;
 661
 662        ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
 663        ide_map_sg(drive, &cmd);
 664
 665        return ide_tape_issue_pc(drive, &cmd, pc);
 666}
 667
 668/*
 669 * Write a filemark if write_filemark=1. Flush the device buffers without
 670 * writing a filemark otherwise.
 671 */
 672static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 673                struct ide_atapi_pc *pc, int write_filemark)
 674{
 675        ide_init_pc(pc);
 676        pc->c[0] = WRITE_FILEMARKS;
 677        pc->c[4] = write_filemark;
 678        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 679}
 680
 681static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 682{
 683        idetape_tape_t *tape = drive->driver_data;
 684        struct gendisk *disk = tape->disk;
 685        int load_attempted = 0;
 686
 687        /* Wait for the tape to become ready */
 688        set_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT), &drive->atapi_flags);
 689        timeout += jiffies;
 690        while (time_before(jiffies, timeout)) {
 691                if (ide_do_test_unit_ready(drive, disk) == 0)
 692                        return 0;
 693                if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 694                    || (tape->asc == 0x3A)) {
 695                        /* no media */
 696                        if (load_attempted)
 697                                return -ENOMEDIUM;
 698                        ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 699                        load_attempted = 1;
 700                /* not about to be ready */
 701                } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 702                             (tape->ascq == 1 || tape->ascq == 8)))
 703                        return -EIO;
 704                msleep(100);
 705        }
 706        return -EIO;
 707}
 708
 709static int idetape_flush_tape_buffers(ide_drive_t *drive)
 710{
 711        struct ide_tape_obj *tape = drive->driver_data;
 712        struct ide_atapi_pc pc;
 713        int rc;
 714
 715        idetape_create_write_filemark_cmd(drive, &pc, 0);
 716        rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
 717        if (rc)
 718                return rc;
 719        idetape_wait_ready(drive, 60 * 5 * HZ);
 720        return 0;
 721}
 722
 723static int ide_tape_read_position(ide_drive_t *drive)
 724{
 725        idetape_tape_t *tape = drive->driver_data;
 726        struct ide_atapi_pc pc;
 727        u8 buf[20];
 728
 729        ide_debug_log(IDE_DBG_FUNC, "enter");
 730
 731        /* prep cmd */
 732        ide_init_pc(&pc);
 733        pc.c[0] = READ_POSITION;
 734        pc.req_xfer = 20;
 735
 736        if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
 737                return -1;
 738
 739        if (!pc.error) {
 740                ide_debug_log(IDE_DBG_FUNC, "BOP - %s",
 741                                (buf[0] & 0x80) ? "Yes" : "No");
 742                ide_debug_log(IDE_DBG_FUNC, "EOP - %s",
 743                                (buf[0] & 0x40) ? "Yes" : "No");
 744
 745                if (buf[0] & 0x4) {
 746                        printk(KERN_INFO "ide-tape: Block location is unknown"
 747                                         "to the tape\n");
 748                        clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 749                                  &drive->atapi_flags);
 750                        return -1;
 751                } else {
 752                        ide_debug_log(IDE_DBG_FUNC, "Block Location: %u",
 753                                      be32_to_cpup((__be32 *)&buf[4]));
 754
 755                        tape->partition = buf[1];
 756                        tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
 757                        set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 758                                &drive->atapi_flags);
 759                }
 760        }
 761
 762        return tape->first_frame;
 763}
 764
 765static void idetape_create_locate_cmd(ide_drive_t *drive,
 766                struct ide_atapi_pc *pc,
 767                unsigned int block, u8 partition, int skip)
 768{
 769        ide_init_pc(pc);
 770        pc->c[0] = POSITION_TO_ELEMENT;
 771        pc->c[1] = 2;
 772        put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 773        pc->c[8] = partition;
 774        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 775}
 776
 777static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 778{
 779        idetape_tape_t *tape = drive->driver_data;
 780
 781        if (tape->chrdev_dir != IDETAPE_DIR_READ)
 782                return;
 783
 784        clear_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
 785        tape->valid = 0;
 786        if (tape->buf != NULL) {
 787                kfree(tape->buf);
 788                tape->buf = NULL;
 789        }
 790
 791        tape->chrdev_dir = IDETAPE_DIR_NONE;
 792}
 793
 794/*
 795 * Position the tape to the requested block using the LOCATE packet command.
 796 * A READ POSITION command is then issued to check where we are positioned. Like
 797 * all higher level operations, we queue the commands at the tail of the request
 798 * queue and wait for their completion.
 799 */
 800static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 801                u8 partition, int skip)
 802{
 803        idetape_tape_t *tape = drive->driver_data;
 804        struct gendisk *disk = tape->disk;
 805        int ret;
 806        struct ide_atapi_pc pc;
 807
 808        if (tape->chrdev_dir == IDETAPE_DIR_READ)
 809                __ide_tape_discard_merge_buffer(drive);
 810        idetape_wait_ready(drive, 60 * 5 * HZ);
 811        idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 812        ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 813        if (ret)
 814                return ret;
 815
 816        ret = ide_tape_read_position(drive);
 817        if (ret < 0)
 818                return ret;
 819        return 0;
 820}
 821
 822static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 823                                          int restore_position)
 824{
 825        idetape_tape_t *tape = drive->driver_data;
 826        int seek, position;
 827
 828        __ide_tape_discard_merge_buffer(drive);
 829        if (restore_position) {
 830                position = ide_tape_read_position(drive);
 831                seek = position > 0 ? position : 0;
 832                if (idetape_position_tape(drive, seek, 0, 0)) {
 833                        printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 834                                         " %s\n", tape->name, __func__);
 835                        return;
 836                }
 837        }
 838}
 839
 840/*
 841 * Generate a read/write request for the block device interface and wait for it
 842 * to be serviced.
 843 */
 844static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 845{
 846        idetape_tape_t *tape = drive->driver_data;
 847        struct request *rq;
 848        int ret;
 849
 850        ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, size: %d", cmd, size);
 851
 852        BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 853        BUG_ON(size < 0 || size % tape->blk_size);
 854
 855        rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
 856        rq->cmd_type = REQ_TYPE_SPECIAL;
 857        rq->cmd[13] = cmd;
 858        rq->rq_disk = tape->disk;
 859        rq->__sector = tape->first_frame;
 860
 861        if (size) {
 862                ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 863                                      __GFP_WAIT);
 864                if (ret)
 865                        goto out_put;
 866        }
 867
 868        blk_execute_rq(drive->queue, tape->disk, rq, 0);
 869
 870        /* calculate the number of transferred bytes and update buffer state */
 871        size -= rq->resid_len;
 872        tape->cur = tape->buf;
 873        if (cmd == REQ_IDETAPE_READ)
 874                tape->valid = size;
 875        else
 876                tape->valid = 0;
 877
 878        ret = size;
 879        if (rq->errors == IDE_DRV_ERROR_GENERAL)
 880                ret = -EIO;
 881out_put:
 882        blk_put_request(rq);
 883        return ret;
 884}
 885
 886static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 887{
 888        ide_init_pc(pc);
 889        pc->c[0] = INQUIRY;
 890        pc->c[4] = 254;
 891        pc->req_xfer = 254;
 892}
 893
 894static void idetape_create_rewind_cmd(ide_drive_t *drive,
 895                struct ide_atapi_pc *pc)
 896{
 897        ide_init_pc(pc);
 898        pc->c[0] = REZERO_UNIT;
 899        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 900}
 901
 902static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 903{
 904        ide_init_pc(pc);
 905        pc->c[0] = ERASE;
 906        pc->c[1] = 1;
 907        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 908}
 909
 910static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 911{
 912        ide_init_pc(pc);
 913        pc->c[0] = SPACE;
 914        put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 915        pc->c[1] = cmd;
 916        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 917}
 918
 919static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 920{
 921        idetape_tape_t *tape = drive->driver_data;
 922
 923        if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 924                printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 925                                " but we are not writing.\n");
 926                return;
 927        }
 928        if (tape->buf) {
 929                size_t aligned = roundup(tape->valid, tape->blk_size);
 930
 931                memset(tape->cur, 0, aligned - tape->valid);
 932                idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 933                kfree(tape->buf);
 934                tape->buf = NULL;
 935        }
 936        tape->chrdev_dir = IDETAPE_DIR_NONE;
 937}
 938
 939static int idetape_init_rw(ide_drive_t *drive, int dir)
 940{
 941        idetape_tape_t *tape = drive->driver_data;
 942        int rc;
 943
 944        BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 945
 946        if (tape->chrdev_dir == dir)
 947                return 0;
 948
 949        if (tape->chrdev_dir == IDETAPE_DIR_READ)
 950                ide_tape_discard_merge_buffer(drive, 1);
 951        else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 952                ide_tape_flush_merge_buffer(drive);
 953                idetape_flush_tape_buffers(drive);
 954        }
 955
 956        if (tape->buf || tape->valid) {
 957                printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 958                tape->valid = 0;
 959        }
 960
 961        tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 962        if (!tape->buf)
 963                return -ENOMEM;
 964        tape->chrdev_dir = dir;
 965        tape->cur = tape->buf;
 966
 967        /*
 968         * Issue a 0 rw command to ensure that DSC handshake is
 969         * switched from completion mode to buffer available mode.  No
 970         * point in issuing this if DSC overlap isn't supported, some
 971         * drives (Seagate STT3401A) will return an error.
 972         */
 973        if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
 974                int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
 975                                                  : REQ_IDETAPE_WRITE;
 976
 977                rc = idetape_queue_rw_tail(drive, cmd, 0);
 978                if (rc < 0) {
 979                        kfree(tape->buf);
 980                        tape->buf = NULL;
 981                        tape->chrdev_dir = IDETAPE_DIR_NONE;
 982                        return rc;
 983                }
 984        }
 985
 986        return 0;
 987}
 988
 989static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
 990{
 991        idetape_tape_t *tape = drive->driver_data;
 992
 993        memset(tape->buf, 0, tape->buffer_size);
 994
 995        while (bcount) {
 996                unsigned int count = min(tape->buffer_size, bcount);
 997
 998                idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
 999                bcount -= count;
1000        }
1001}
1002
1003/*
1004 * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1005 * currently support only one partition.
1006 */
1007static int idetape_rewind_tape(ide_drive_t *drive)
1008{
1009        struct ide_tape_obj *tape = drive->driver_data;
1010        struct gendisk *disk = tape->disk;
1011        struct ide_atapi_pc pc;
1012        int ret;
1013
1014        ide_debug_log(IDE_DBG_FUNC, "enter");
1015
1016        idetape_create_rewind_cmd(drive, &pc);
1017        ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1018        if (ret)
1019                return ret;
1020
1021        ret = ide_tape_read_position(drive);
1022        if (ret < 0)
1023                return ret;
1024        return 0;
1025}
1026
1027/* mtio.h compatible commands should be issued to the chrdev interface. */
1028static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1029                                unsigned long arg)
1030{
1031        idetape_tape_t *tape = drive->driver_data;
1032        void __user *argp = (void __user *)arg;
1033
1034        struct idetape_config {
1035                int dsc_rw_frequency;
1036                int dsc_media_access_frequency;
1037                int nr_stages;
1038        } config;
1039
1040        ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%04x", cmd);
1041
1042        switch (cmd) {
1043        case 0x0340:
1044                if (copy_from_user(&config, argp, sizeof(config)))
1045                        return -EFAULT;
1046                tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1047                break;
1048        case 0x0350:
1049                memset(&config, 0, sizeof(config));
1050                config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1051                config.nr_stages = 1;
1052                if (copy_to_user(argp, &config, sizeof(config)))
1053                        return -EFAULT;
1054                break;
1055        default:
1056                return -EIO;
1057        }
1058        return 0;
1059}
1060
1061static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1062                                        int mt_count)
1063{
1064        idetape_tape_t *tape = drive->driver_data;
1065        struct gendisk *disk = tape->disk;
1066        struct ide_atapi_pc pc;
1067        int retval, count = 0;
1068        int sprev = !!(tape->caps[4] & 0x20);
1069
1070
1071        ide_debug_log(IDE_DBG_FUNC, "mt_op: %d, mt_count: %d", mt_op, mt_count);
1072
1073        if (mt_count == 0)
1074                return 0;
1075        if (MTBSF == mt_op || MTBSFM == mt_op) {
1076                if (!sprev)
1077                        return -EIO;
1078                mt_count = -mt_count;
1079        }
1080
1081        if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1082                tape->valid = 0;
1083                if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1084                                       &drive->atapi_flags))
1085                        ++count;
1086                ide_tape_discard_merge_buffer(drive, 0);
1087        }
1088
1089        switch (mt_op) {
1090        case MTFSF:
1091        case MTBSF:
1092                idetape_create_space_cmd(&pc, mt_count - count,
1093                                         IDETAPE_SPACE_OVER_FILEMARK);
1094                return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1095        case MTFSFM:
1096        case MTBSFM:
1097                if (!sprev)
1098                        return -EIO;
1099                retval = idetape_space_over_filemarks(drive, MTFSF,
1100                                                      mt_count - count);
1101                if (retval)
1102                        return retval;
1103                count = (MTBSFM == mt_op ? 1 : -1);
1104                return idetape_space_over_filemarks(drive, MTFSF, count);
1105        default:
1106                printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1107                                mt_op);
1108                return -EIO;
1109        }
1110}
1111
1112/*
1113 * Our character device read / write functions.
1114 *
1115 * The tape is optimized to maximize throughput when it is transferring an
1116 * integral number of the "continuous transfer limit", which is a parameter of
1117 * the specific tape (26kB on my particular tape, 32kB for Onstream).
1118 *
1119 * As of version 1.3 of the driver, the character device provides an abstract
1120 * continuous view of the media - any mix of block sizes (even 1 byte) on the
1121 * same backup/restore procedure is supported. The driver will internally
1122 * convert the requests to the recommended transfer unit, so that an unmatch
1123 * between the user's block size to the recommended size will only result in a
1124 * (slightly) increased driver overhead, but will no longer hit performance.
1125 * This is not applicable to Onstream.
1126 */
1127static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1128                                   size_t count, loff_t *ppos)
1129{
1130        struct ide_tape_obj *tape = file->private_data;
1131        ide_drive_t *drive = tape->drive;
1132        size_t done = 0;
1133        ssize_t ret = 0;
1134        int rc;
1135
1136        ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1137
1138        if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1139                if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1140                        if (count > tape->blk_size &&
1141                            (count % tape->blk_size) == 0)
1142                                tape->user_bs_factor = count / tape->blk_size;
1143        }
1144
1145        rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1146        if (rc < 0)
1147                return rc;
1148
1149        while (done < count) {
1150                size_t todo;
1151
1152                /* refill if staging buffer is empty */
1153                if (!tape->valid) {
1154                        /* If we are at a filemark, nothing more to read */
1155                        if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1156                                     &drive->atapi_flags))
1157                                break;
1158                        /* read */
1159                        if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1160                                                  tape->buffer_size) <= 0)
1161                                break;
1162                }
1163
1164                /* copy out */
1165                todo = min_t(size_t, count - done, tape->valid);
1166                if (copy_to_user(buf + done, tape->cur, todo))
1167                        ret = -EFAULT;
1168
1169                tape->cur += todo;
1170                tape->valid -= todo;
1171                done += todo;
1172        }
1173
1174        if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1175                idetape_space_over_filemarks(drive, MTFSF, 1);
1176                return 0;
1177        }
1178
1179        return ret ? ret : done;
1180}
1181
1182static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1183                                     size_t count, loff_t *ppos)
1184{
1185        struct ide_tape_obj *tape = file->private_data;
1186        ide_drive_t *drive = tape->drive;
1187        size_t done = 0;
1188        ssize_t ret = 0;
1189        int rc;
1190
1191        /* The drive is write protected. */
1192        if (tape->write_prot)
1193                return -EACCES;
1194
1195        ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1196
1197        /* Initialize write operation */
1198        rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1199        if (rc < 0)
1200                return rc;
1201
1202        while (done < count) {
1203                size_t todo;
1204
1205                /* flush if staging buffer is full */
1206                if (tape->valid == tape->buffer_size &&
1207                    idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1208                                          tape->buffer_size) <= 0)
1209                        return rc;
1210
1211                /* copy in */
1212                todo = min_t(size_t, count - done,
1213                             tape->buffer_size - tape->valid);
1214                if (copy_from_user(tape->cur, buf + done, todo))
1215                        ret = -EFAULT;
1216
1217                tape->cur += todo;
1218                tape->valid += todo;
1219                done += todo;
1220        }
1221
1222        return ret ? ret : done;
1223}
1224
1225static int idetape_write_filemark(ide_drive_t *drive)
1226{
1227        struct ide_tape_obj *tape = drive->driver_data;
1228        struct ide_atapi_pc pc;
1229
1230        /* Write a filemark */
1231        idetape_create_write_filemark_cmd(drive, &pc, 1);
1232        if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1233                printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1234                return -EIO;
1235        }
1236        return 0;
1237}
1238
1239/*
1240 * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1241 * requested.
1242 *
1243 * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1244 * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1245 * usually not supported.
1246 *
1247 * The following commands are currently not supported:
1248 *
1249 * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1250 * MT_ST_WRITE_THRESHOLD.
1251 */
1252static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1253{
1254        idetape_tape_t *tape = drive->driver_data;
1255        struct gendisk *disk = tape->disk;
1256        struct ide_atapi_pc pc;
1257        int i, retval;
1258
1259        ide_debug_log(IDE_DBG_FUNC, "MTIOCTOP ioctl: mt_op: %d, mt_count: %d",
1260                      mt_op, mt_count);
1261
1262        switch (mt_op) {
1263        case MTFSF:
1264        case MTFSFM:
1265        case MTBSF:
1266        case MTBSFM:
1267                if (!mt_count)
1268                        return 0;
1269                return idetape_space_over_filemarks(drive, mt_op, mt_count);
1270        default:
1271                break;
1272        }
1273
1274        switch (mt_op) {
1275        case MTWEOF:
1276                if (tape->write_prot)
1277                        return -EACCES;
1278                ide_tape_discard_merge_buffer(drive, 1);
1279                for (i = 0; i < mt_count; i++) {
1280                        retval = idetape_write_filemark(drive);
1281                        if (retval)
1282                                return retval;
1283                }
1284                return 0;
1285        case MTREW:
1286                ide_tape_discard_merge_buffer(drive, 0);
1287                if (idetape_rewind_tape(drive))
1288                        return -EIO;
1289                return 0;
1290        case MTLOAD:
1291                ide_tape_discard_merge_buffer(drive, 0);
1292                return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1293        case MTUNLOAD:
1294        case MTOFFL:
1295                /*
1296                 * If door is locked, attempt to unlock before
1297                 * attempting to eject.
1298                 */
1299                if (tape->door_locked) {
1300                        if (!ide_set_media_lock(drive, disk, 0))
1301                                tape->door_locked = DOOR_UNLOCKED;
1302                }
1303                ide_tape_discard_merge_buffer(drive, 0);
1304                retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1305                if (!retval)
1306                        clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1307                                  &drive->atapi_flags);
1308                return retval;
1309        case MTNOP:
1310                ide_tape_discard_merge_buffer(drive, 0);
1311                return idetape_flush_tape_buffers(drive);
1312        case MTRETEN:
1313                ide_tape_discard_merge_buffer(drive, 0);
1314                return ide_do_start_stop(drive, disk,
1315                        IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1316        case MTEOM:
1317                idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1318                return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1319        case MTERASE:
1320                (void)idetape_rewind_tape(drive);
1321                idetape_create_erase_cmd(&pc);
1322                return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1323        case MTSETBLK:
1324                if (mt_count) {
1325                        if (mt_count < tape->blk_size ||
1326                            mt_count % tape->blk_size)
1327                                return -EIO;
1328                        tape->user_bs_factor = mt_count / tape->blk_size;
1329                        clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1330                                  &drive->atapi_flags);
1331                } else
1332                        set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1333                                &drive->atapi_flags);
1334                return 0;
1335        case MTSEEK:
1336                ide_tape_discard_merge_buffer(drive, 0);
1337                return idetape_position_tape(drive,
1338                        mt_count * tape->user_bs_factor, tape->partition, 0);
1339        case MTSETPART:
1340                ide_tape_discard_merge_buffer(drive, 0);
1341                return idetape_position_tape(drive, 0, mt_count, 0);
1342        case MTFSR:
1343        case MTBSR:
1344        case MTLOCK:
1345                retval = ide_set_media_lock(drive, disk, 1);
1346                if (retval)
1347                        return retval;
1348                tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1349                return 0;
1350        case MTUNLOCK:
1351                retval = ide_set_media_lock(drive, disk, 0);
1352                if (retval)
1353                        return retval;
1354                tape->door_locked = DOOR_UNLOCKED;
1355                return 0;
1356        default:
1357                printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1358                                mt_op);
1359                return -EIO;
1360        }
1361}
1362
1363/*
1364 * Our character device ioctls. General mtio.h magnetic io commands are
1365 * supported here, and not in the corresponding block interface. Our own
1366 * ide-tape ioctls are supported on both interfaces.
1367 */
1368static long do_idetape_chrdev_ioctl(struct file *file,
1369                                unsigned int cmd, unsigned long arg)
1370{
1371        struct ide_tape_obj *tape = file->private_data;
1372        ide_drive_t *drive = tape->drive;
1373        struct mtop mtop;
1374        struct mtget mtget;
1375        struct mtpos mtpos;
1376        int block_offset = 0, position = tape->first_frame;
1377        void __user *argp = (void __user *)arg;
1378
1379        ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x", cmd);
1380
1381        if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1382                ide_tape_flush_merge_buffer(drive);
1383                idetape_flush_tape_buffers(drive);
1384        }
1385        if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1386                block_offset = tape->valid /
1387                        (tape->blk_size * tape->user_bs_factor);
1388                position = ide_tape_read_position(drive);
1389                if (position < 0)
1390                        return -EIO;
1391        }
1392        switch (cmd) {
1393        case MTIOCTOP:
1394                if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1395                        return -EFAULT;
1396                return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1397        case MTIOCGET:
1398                memset(&mtget, 0, sizeof(struct mtget));
1399                mtget.mt_type = MT_ISSCSI2;
1400                mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1401                mtget.mt_dsreg =
1402                        ((tape->blk_size * tape->user_bs_factor)
1403                         << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1404
1405                if (tape->drv_write_prot)
1406                        mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1407
1408                if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1409                        return -EFAULT;
1410                return 0;
1411        case MTIOCPOS:
1412                mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1413                if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1414                        return -EFAULT;
1415                return 0;
1416        default:
1417                if (tape->chrdev_dir == IDETAPE_DIR_READ)
1418                        ide_tape_discard_merge_buffer(drive, 1);
1419                return idetape_blkdev_ioctl(drive, cmd, arg);
1420        }
1421}
1422
1423static long idetape_chrdev_ioctl(struct file *file,
1424                                unsigned int cmd, unsigned long arg)
1425{
1426        long ret;
1427        mutex_lock(&ide_tape_mutex);
1428        ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1429        mutex_unlock(&ide_tape_mutex);
1430        return ret;
1431}
1432
1433/*
1434 * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1435 * block size with the reported value.
1436 */
1437static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1438{
1439        idetape_tape_t *tape = drive->driver_data;
1440        struct ide_atapi_pc pc;
1441        u8 buf[12];
1442
1443        idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1444        if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1445                printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1446                if (tape->blk_size == 0) {
1447                        printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1448                                            "block size, assuming 32k\n");
1449                        tape->blk_size = 32768;
1450                }
1451                return;
1452        }
1453        tape->blk_size = (buf[4 + 5] << 16) +
1454                                (buf[4 + 6] << 8)  +
1455                                 buf[4 + 7];
1456        tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1457
1458        ide_debug_log(IDE_DBG_FUNC, "blk_size: %d, write_prot: %d",
1459                      tape->blk_size, tape->drv_write_prot);
1460}
1461
1462static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1463{
1464        unsigned int minor = iminor(inode), i = minor & ~0xc0;
1465        ide_drive_t *drive;
1466        idetape_tape_t *tape;
1467        int retval;
1468
1469        if (i >= MAX_HWIFS * MAX_DRIVES)
1470                return -ENXIO;
1471
1472        mutex_lock(&idetape_chrdev_mutex);
1473
1474        tape = ide_tape_get(NULL, true, i);
1475        if (!tape) {
1476                mutex_unlock(&idetape_chrdev_mutex);
1477                return -ENXIO;
1478        }
1479
1480        drive = tape->drive;
1481        filp->private_data = tape;
1482
1483        ide_debug_log(IDE_DBG_FUNC, "enter");
1484
1485        /*
1486         * We really want to do nonseekable_open(inode, filp); here, but some
1487         * versions of tar incorrectly call lseek on tapes and bail out if that
1488         * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1489         */
1490        filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1491
1492
1493        if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1494                retval = -EBUSY;
1495                goto out_put_tape;
1496        }
1497
1498        retval = idetape_wait_ready(drive, 60 * HZ);
1499        if (retval) {
1500                clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1501                printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1502                goto out_put_tape;
1503        }
1504
1505        ide_tape_read_position(drive);
1506        if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1507                (void)idetape_rewind_tape(drive);
1508
1509        /* Read block size and write protect status from drive. */
1510        ide_tape_get_bsize_from_bdesc(drive);
1511
1512        /* Set write protect flag if device is opened as read-only. */
1513        if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1514                tape->write_prot = 1;
1515        else
1516                tape->write_prot = tape->drv_write_prot;
1517
1518        /* Make sure drive isn't write protected if user wants to write. */
1519        if (tape->write_prot) {
1520                if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1521                    (filp->f_flags & O_ACCMODE) == O_RDWR) {
1522                        clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1523                        retval = -EROFS;
1524                        goto out_put_tape;
1525                }
1526        }
1527
1528        /* Lock the tape drive door so user can't eject. */
1529        if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1530                if (!ide_set_media_lock(drive, tape->disk, 1)) {
1531                        if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1532                                tape->door_locked = DOOR_LOCKED;
1533                }
1534        }
1535        mutex_unlock(&idetape_chrdev_mutex);
1536
1537        return 0;
1538
1539out_put_tape:
1540        ide_tape_put(tape);
1541
1542        mutex_unlock(&idetape_chrdev_mutex);
1543
1544        return retval;
1545}
1546
1547static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1548{
1549        idetape_tape_t *tape = drive->driver_data;
1550
1551        ide_tape_flush_merge_buffer(drive);
1552        tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1553        if (tape->buf != NULL) {
1554                idetape_pad_zeros(drive, tape->blk_size *
1555                                (tape->user_bs_factor - 1));
1556                kfree(tape->buf);
1557                tape->buf = NULL;
1558        }
1559        idetape_write_filemark(drive);
1560        idetape_flush_tape_buffers(drive);
1561        idetape_flush_tape_buffers(drive);
1562}
1563
1564static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1565{
1566        struct ide_tape_obj *tape = filp->private_data;
1567        ide_drive_t *drive = tape->drive;
1568        unsigned int minor = iminor(inode);
1569
1570        mutex_lock(&idetape_chrdev_mutex);
1571
1572        tape = drive->driver_data;
1573
1574        ide_debug_log(IDE_DBG_FUNC, "enter");
1575
1576        if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1577                idetape_write_release(drive, minor);
1578        if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1579                if (minor < 128)
1580                        ide_tape_discard_merge_buffer(drive, 1);
1581        }
1582
1583        if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1584                                    &drive->atapi_flags))
1585                (void) idetape_rewind_tape(drive);
1586
1587        if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1588                if (tape->door_locked == DOOR_LOCKED) {
1589                        if (!ide_set_media_lock(drive, tape->disk, 0))
1590                                tape->door_locked = DOOR_UNLOCKED;
1591                }
1592        }
1593        clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1594        ide_tape_put(tape);
1595
1596        mutex_unlock(&idetape_chrdev_mutex);
1597
1598        return 0;
1599}
1600
1601static void idetape_get_inquiry_results(ide_drive_t *drive)
1602{
1603        idetape_tape_t *tape = drive->driver_data;
1604        struct ide_atapi_pc pc;
1605        u8 pc_buf[256];
1606        char fw_rev[4], vendor_id[8], product_id[16];
1607
1608        idetape_create_inquiry_cmd(&pc);
1609        if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1610                printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1611                                tape->name);
1612                return;
1613        }
1614        memcpy(vendor_id, &pc_buf[8], 8);
1615        memcpy(product_id, &pc_buf[16], 16);
1616        memcpy(fw_rev, &pc_buf[32], 4);
1617
1618        ide_fixstring(vendor_id, 8, 0);
1619        ide_fixstring(product_id, 16, 0);
1620        ide_fixstring(fw_rev, 4, 0);
1621
1622        printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1623                        drive->name, tape->name, vendor_id, product_id, fw_rev);
1624}
1625
1626/*
1627 * Ask the tape about its various parameters. In particular, we will adjust our
1628 * data transfer buffer size to the recommended value as returned by the tape.
1629 */
1630static void idetape_get_mode_sense_results(ide_drive_t *drive)
1631{
1632        idetape_tape_t *tape = drive->driver_data;
1633        struct ide_atapi_pc pc;
1634        u8 buf[24], *caps;
1635        u8 speed, max_speed;
1636
1637        idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1638        if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1639                printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1640                                " some default values\n");
1641                tape->blk_size = 512;
1642                put_unaligned(52,   (u16 *)&tape->caps[12]);
1643                put_unaligned(540,  (u16 *)&tape->caps[14]);
1644                put_unaligned(6*52, (u16 *)&tape->caps[16]);
1645                return;
1646        }
1647        caps = buf + 4 + buf[3];
1648
1649        /* convert to host order and save for later use */
1650        speed = be16_to_cpup((__be16 *)&caps[14]);
1651        max_speed = be16_to_cpup((__be16 *)&caps[8]);
1652
1653        *(u16 *)&caps[8] = max_speed;
1654        *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1655        *(u16 *)&caps[14] = speed;
1656        *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1657
1658        if (!speed) {
1659                printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1660                                "(assuming 650KB/sec)\n", drive->name);
1661                *(u16 *)&caps[14] = 650;
1662        }
1663        if (!max_speed) {
1664                printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1665                                "(assuming 650KB/sec)\n", drive->name);
1666                *(u16 *)&caps[8] = 650;
1667        }
1668
1669        memcpy(&tape->caps, caps, 20);
1670
1671        /* device lacks locking support according to capabilities page */
1672        if ((caps[6] & 1) == 0)
1673                drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1674
1675        if (caps[7] & 0x02)
1676                tape->blk_size = 512;
1677        else if (caps[7] & 0x04)
1678                tape->blk_size = 1024;
1679}
1680
1681#ifdef CONFIG_IDE_PROC_FS
1682#define ide_tape_devset_get(name, field) \
1683static int get_##name(ide_drive_t *drive) \
1684{ \
1685        idetape_tape_t *tape = drive->driver_data; \
1686        return tape->field; \
1687}
1688
1689#define ide_tape_devset_set(name, field) \
1690static int set_##name(ide_drive_t *drive, int arg) \
1691{ \
1692        idetape_tape_t *tape = drive->driver_data; \
1693        tape->field = arg; \
1694        return 0; \
1695}
1696
1697#define ide_tape_devset_rw_field(_name, _field) \
1698ide_tape_devset_get(_name, _field) \
1699ide_tape_devset_set(_name, _field) \
1700IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1701
1702#define ide_tape_devset_r_field(_name, _field) \
1703ide_tape_devset_get(_name, _field) \
1704IDE_DEVSET(_name, 0, get_##_name, NULL)
1705
1706static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1707static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1708static int divf_buffer(ide_drive_t *drive)      { return    2; }
1709static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1710
1711ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1712
1713ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1714
1715ide_tape_devset_r_field(avg_speed, avg_speed);
1716ide_tape_devset_r_field(speed, caps[14]);
1717ide_tape_devset_r_field(buffer, caps[16]);
1718ide_tape_devset_r_field(buffer_size, buffer_size);
1719
1720static const struct ide_proc_devset idetape_settings[] = {
1721        __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1722        __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1723        __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1724        __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1725        __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1726        __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1727                                        mulf_tdsc, divf_tdsc),
1728        { NULL },
1729};
1730#endif
1731
1732/*
1733 * The function below is called to:
1734 *
1735 * 1. Initialize our various state variables.
1736 * 2. Ask the tape for its capabilities.
1737 * 3. Allocate a buffer which will be used for data transfer. The buffer size
1738 * is chosen based on the recommendation which we received in step 2.
1739 *
1740 * Note that at this point ide.c already assigned us an irq, so that we can
1741 * queue requests here and wait for their completion.
1742 */
1743static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1744{
1745        unsigned long t;
1746        int speed;
1747        int buffer_size;
1748        u16 *ctl = (u16 *)&tape->caps[12];
1749
1750        ide_debug_log(IDE_DBG_FUNC, "minor: %d", minor);
1751
1752        drive->pc_callback = ide_tape_callback;
1753
1754        drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1755
1756        if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1757                printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1758                                 tape->name);
1759                drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1760        }
1761
1762        /* Seagate Travan drives do not support DSC overlap. */
1763        if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1764                drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1765
1766        tape->minor = minor;
1767        tape->name[0] = 'h';
1768        tape->name[1] = 't';
1769        tape->name[2] = '0' + minor;
1770        tape->chrdev_dir = IDETAPE_DIR_NONE;
1771
1772        idetape_get_inquiry_results(drive);
1773        idetape_get_mode_sense_results(drive);
1774        ide_tape_get_bsize_from_bdesc(drive);
1775        tape->user_bs_factor = 1;
1776        tape->buffer_size = *ctl * tape->blk_size;
1777        while (tape->buffer_size > 0xffff) {
1778                printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1779                *ctl /= 2;
1780                tape->buffer_size = *ctl * tape->blk_size;
1781        }
1782        buffer_size = tape->buffer_size;
1783
1784        /* select the "best" DSC read/write polling freq */
1785        speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1786
1787        t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1788
1789        /*
1790         * Ensure that the number we got makes sense; limit it within
1791         * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1792         */
1793        tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1794                                         IDETAPE_DSC_RW_MAX);
1795        printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1796                "%lums tDSC%s\n",
1797                drive->name, tape->name, *(u16 *)&tape->caps[14],
1798                (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1799                tape->buffer_size / 1024,
1800                tape->best_dsc_rw_freq * 1000 / HZ,
1801                (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1802
1803        ide_proc_register_driver(drive, tape->driver);
1804}
1805
1806static void ide_tape_remove(ide_drive_t *drive)
1807{
1808        idetape_tape_t *tape = drive->driver_data;
1809
1810        ide_proc_unregister_driver(drive, tape->driver);
1811        device_del(&tape->dev);
1812        ide_unregister_region(tape->disk);
1813
1814        mutex_lock(&idetape_ref_mutex);
1815        put_device(&tape->dev);
1816        mutex_unlock(&idetape_ref_mutex);
1817}
1818
1819static void ide_tape_release(struct device *dev)
1820{
1821        struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1822        ide_drive_t *drive = tape->drive;
1823        struct gendisk *g = tape->disk;
1824
1825        BUG_ON(tape->valid);
1826
1827        drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1828        drive->driver_data = NULL;
1829        device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1830        device_destroy(idetape_sysfs_class,
1831                        MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1832        idetape_devs[tape->minor] = NULL;
1833        g->private_data = NULL;
1834        put_disk(g);
1835        kfree(tape);
1836}
1837
1838#ifdef CONFIG_IDE_PROC_FS
1839static int idetape_name_proc_show(struct seq_file *m, void *v)
1840{
1841        ide_drive_t     *drive = (ide_drive_t *) m->private;
1842        idetape_tape_t  *tape = drive->driver_data;
1843
1844        seq_printf(m, "%s\n", tape->name);
1845        return 0;
1846}
1847
1848static int idetape_name_proc_open(struct inode *inode, struct file *file)
1849{
1850        return single_open(file, idetape_name_proc_show, PDE_DATA(inode));
1851}
1852
1853static const struct file_operations idetape_name_proc_fops = {
1854        .owner          = THIS_MODULE,
1855        .open           = idetape_name_proc_open,
1856        .read           = seq_read,
1857        .llseek         = seq_lseek,
1858        .release        = single_release,
1859};
1860
1861static ide_proc_entry_t idetape_proc[] = {
1862        { "capacity",   S_IFREG|S_IRUGO,        &ide_capacity_proc_fops },
1863        { "name",       S_IFREG|S_IRUGO,        &idetape_name_proc_fops },
1864        {}
1865};
1866
1867static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1868{
1869        return idetape_proc;
1870}
1871
1872static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1873{
1874        return idetape_settings;
1875}
1876#endif
1877
1878static int ide_tape_probe(ide_drive_t *);
1879
1880static 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. */
1897static const struct file_operations idetape_fops = {
1898        .owner          = THIS_MODULE,
1899        .read           = idetape_chrdev_read,
1900        .write          = idetape_chrdev_write,
1901        .unlocked_ioctl = idetape_chrdev_ioctl,
1902        .open           = idetape_chrdev_open,
1903        .release        = idetape_chrdev_release,
1904        .llseek         = noop_llseek,
1905};
1906
1907static int idetape_open(struct block_device *bdev, fmode_t mode)
1908{
1909        struct ide_tape_obj *tape;
1910
1911        mutex_lock(&ide_tape_mutex);
1912        tape = ide_tape_get(bdev->bd_disk, false, 0);
1913        mutex_unlock(&ide_tape_mutex);
1914
1915        if (!tape)
1916                return -ENXIO;
1917
1918        return 0;
1919}
1920
1921static void idetape_release(struct gendisk *disk, fmode_t mode)
1922{
1923        struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1924
1925        mutex_lock(&ide_tape_mutex);
1926        ide_tape_put(tape);
1927        mutex_unlock(&ide_tape_mutex);
1928}
1929
1930static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1931                        unsigned int cmd, unsigned long arg)
1932{
1933        struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1934        ide_drive_t *drive = tape->drive;
1935        int err;
1936
1937        mutex_lock(&ide_tape_mutex);
1938        err = generic_ide_ioctl(drive, bdev, cmd, arg);
1939        if (err == -EINVAL)
1940                err = idetape_blkdev_ioctl(drive, cmd, arg);
1941        mutex_unlock(&ide_tape_mutex);
1942
1943        return err;
1944}
1945
1946static const struct block_device_operations idetape_block_ops = {
1947        .owner          = THIS_MODULE,
1948        .open           = idetape_open,
1949        .release        = idetape_release,
1950        .ioctl          = idetape_ioctl,
1951};
1952
1953static int ide_tape_probe(ide_drive_t *drive)
1954{
1955        idetape_tape_t *tape;
1956        struct gendisk *g;
1957        int minor;
1958
1959        ide_debug_log(IDE_DBG_FUNC, "enter");
1960
1961        if (!strstr(DRV_NAME, drive->driver_req))
1962                goto failed;
1963
1964        if (drive->media != ide_tape)
1965                goto failed;
1966
1967        if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1968            ide_check_atapi_device(drive, DRV_NAME) == 0) {
1969                printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1970                                " the driver\n", drive->name);
1971                goto failed;
1972        }
1973        tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1974        if (tape == NULL) {
1975                printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1976                                drive->name);
1977                goto failed;
1978        }
1979
1980        g = alloc_disk(1 << PARTN_BITS);
1981        if (!g)
1982                goto out_free_tape;
1983
1984        ide_init_disk(g, drive);
1985
1986        tape->dev.parent = &drive->gendev;
1987        tape->dev.release = ide_tape_release;
1988        dev_set_name(&tape->dev, "%s", dev_name(&drive->gendev));
1989
1990        if (device_register(&tape->dev))
1991                goto out_free_disk;
1992
1993        tape->drive = drive;
1994        tape->driver = &idetape_driver;
1995        tape->disk = g;
1996
1997        g->private_data = &tape->driver;
1998
1999        drive->driver_data = tape;
2000
2001        mutex_lock(&idetape_ref_mutex);
2002        for (minor = 0; idetape_devs[minor]; minor++)
2003                ;
2004        idetape_devs[minor] = tape;
2005        mutex_unlock(&idetape_ref_mutex);
2006
2007        idetape_setup(drive, tape, minor);
2008
2009        device_create(idetape_sysfs_class, &drive->gendev,
2010                      MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2011        device_create(idetape_sysfs_class, &drive->gendev,
2012                      MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2013                      "n%s", tape->name);
2014
2015        g->fops = &idetape_block_ops;
2016        ide_register_region(g);
2017
2018        return 0;
2019
2020out_free_disk:
2021        put_disk(g);
2022out_free_tape:
2023        kfree(tape);
2024failed:
2025        return -ENODEV;
2026}
2027
2028static void __exit idetape_exit(void)
2029{
2030        driver_unregister(&idetape_driver.gen_driver);
2031        class_destroy(idetape_sysfs_class);
2032        unregister_chrdev(IDETAPE_MAJOR, "ht");
2033}
2034
2035static int __init idetape_init(void)
2036{
2037        int error = 1;
2038        idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2039        if (IS_ERR(idetape_sysfs_class)) {
2040                idetape_sysfs_class = NULL;
2041                printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2042                error = -EBUSY;
2043                goto out;
2044        }
2045
2046        if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2047                printk(KERN_ERR "ide-tape: Failed to register chrdev"
2048                                " interface\n");
2049                error = -EBUSY;
2050                goto out_free_class;
2051        }
2052
2053        error = driver_register(&idetape_driver.gen_driver);
2054        if (error)
2055                goto out_free_driver;
2056
2057        return 0;
2058
2059out_free_driver:
2060        driver_unregister(&idetape_driver.gen_driver);
2061out_free_class:
2062        class_destroy(idetape_sysfs_class);
2063out:
2064        return error;
2065}
2066
2067MODULE_ALIAS("ide:*m-tape*");
2068module_init(idetape_init);
2069module_exit(idetape_exit);
2070MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2071MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2072MODULE_LICENSE("GPL");
2073
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