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                scsi_req(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) - scsi_req(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) - scsi_req(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        scsi_req(rq)->result = 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, BLK_STS_IOERR, 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(scsi_req(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        struct scsi_request *req = scsi_req(rq);
 574        u8 stat;
 575
 576        ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, sector: %llu, nr_sectors: %u",
 577                      req->cmd[0], (unsigned long long)blk_rq_pos(rq),
 578                      blk_rq_sectors(rq));
 579
 580        BUG_ON(!blk_rq_is_private(rq));
 581        BUG_ON(ide_req(rq)->type != ATA_PRIV_MISC &&
 582               ide_req(rq)->type != ATA_PRIV_SENSE);
 583
 584        /* Retry a failed packet command */
 585        if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
 586                pc = drive->failed_pc;
 587                goto out;
 588        }
 589
 590        /*
 591         * If the tape is still busy, postpone our request and service
 592         * the other device meanwhile.
 593         */
 594        stat = hwif->tp_ops->read_status(hwif);
 595
 596        if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
 597            (req->cmd[13] & REQ_IDETAPE_PC2) == 0)
 598                drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 599
 600        if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
 601                drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 602                drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
 603        }
 604
 605        if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
 606            !(stat & ATA_DSC)) {
 607                if (!tape->postponed_rq) {
 608                        tape->dsc_polling_start = jiffies;
 609                        tape->dsc_poll_freq = tape->best_dsc_rw_freq;
 610                        tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
 611                } else if (time_after(jiffies, tape->dsc_timeout)) {
 612                        printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
 613                                tape->name);
 614                        if (req->cmd[13] & REQ_IDETAPE_PC2) {
 615                                idetape_media_access_finished(drive);
 616                                return ide_stopped;
 617                        } else {
 618                                return ide_do_reset(drive);
 619                        }
 620                } else if (time_after(jiffies,
 621                                        tape->dsc_polling_start +
 622                                        IDETAPE_DSC_MA_THRESHOLD))
 623                        tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
 624                ide_tape_stall_queue(drive);
 625                return ide_stopped;
 626        } else {
 627                drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
 628                tape->postponed_rq = false;
 629        }
 630
 631        if (req->cmd[13] & REQ_IDETAPE_READ) {
 632                pc = &tape->queued_pc;
 633                ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
 634                goto out;
 635        }
 636        if (req->cmd[13] & REQ_IDETAPE_WRITE) {
 637                pc = &tape->queued_pc;
 638                ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
 639                goto out;
 640        }
 641        if (req->cmd[13] & REQ_IDETAPE_PC1) {
 642                pc = (struct ide_atapi_pc *)ide_req(rq)->special;
 643                req->cmd[13] &= ~(REQ_IDETAPE_PC1);
 644                req->cmd[13] |= REQ_IDETAPE_PC2;
 645                goto out;
 646        }
 647        if (req->cmd[13] & REQ_IDETAPE_PC2) {
 648                idetape_media_access_finished(drive);
 649                return ide_stopped;
 650        }
 651        BUG();
 652
 653out:
 654        /* prepare sense request for this command */
 655        ide_prep_sense(drive, rq);
 656
 657        memset(&cmd, 0, sizeof(cmd));
 658
 659        if (rq_data_dir(rq))
 660                cmd.tf_flags |= IDE_TFLAG_WRITE;
 661
 662        cmd.rq = rq;
 663
 664        ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
 665        ide_map_sg(drive, &cmd);
 666
 667        return ide_tape_issue_pc(drive, &cmd, pc);
 668}
 669
 670/*
 671 * Write a filemark if write_filemark=1. Flush the device buffers without
 672 * writing a filemark otherwise.
 673 */
 674static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
 675                struct ide_atapi_pc *pc, int write_filemark)
 676{
 677        ide_init_pc(pc);
 678        pc->c[0] = WRITE_FILEMARKS;
 679        pc->c[4] = write_filemark;
 680        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 681}
 682
 683static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 684{
 685        idetape_tape_t *tape = drive->driver_data;
 686        struct gendisk *disk = tape->disk;
 687        int load_attempted = 0;
 688
 689        /* Wait for the tape to become ready */
 690        set_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT), &drive->atapi_flags);
 691        timeout += jiffies;
 692        while (time_before(jiffies, timeout)) {
 693                if (ide_do_test_unit_ready(drive, disk) == 0)
 694                        return 0;
 695                if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
 696                    || (tape->asc == 0x3A)) {
 697                        /* no media */
 698                        if (load_attempted)
 699                                return -ENOMEDIUM;
 700                        ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
 701                        load_attempted = 1;
 702                /* not about to be ready */
 703                } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
 704                             (tape->ascq == 1 || tape->ascq == 8)))
 705                        return -EIO;
 706                msleep(100);
 707        }
 708        return -EIO;
 709}
 710
 711static int idetape_flush_tape_buffers(ide_drive_t *drive)
 712{
 713        struct ide_tape_obj *tape = drive->driver_data;
 714        struct ide_atapi_pc pc;
 715        int rc;
 716
 717        idetape_create_write_filemark_cmd(drive, &pc, 0);
 718        rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
 719        if (rc)
 720                return rc;
 721        idetape_wait_ready(drive, 60 * 5 * HZ);
 722        return 0;
 723}
 724
 725static int ide_tape_read_position(ide_drive_t *drive)
 726{
 727        idetape_tape_t *tape = drive->driver_data;
 728        struct ide_atapi_pc pc;
 729        u8 buf[20];
 730
 731        ide_debug_log(IDE_DBG_FUNC, "enter");
 732
 733        /* prep cmd */
 734        ide_init_pc(&pc);
 735        pc.c[0] = READ_POSITION;
 736        pc.req_xfer = 20;
 737
 738        if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
 739                return -1;
 740
 741        if (!pc.error) {
 742                ide_debug_log(IDE_DBG_FUNC, "BOP - %s",
 743                                (buf[0] & 0x80) ? "Yes" : "No");
 744                ide_debug_log(IDE_DBG_FUNC, "EOP - %s",
 745                                (buf[0] & 0x40) ? "Yes" : "No");
 746
 747                if (buf[0] & 0x4) {
 748                        printk(KERN_INFO "ide-tape: Block location is unknown"
 749                                         "to the tape\n");
 750                        clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 751                                  &drive->atapi_flags);
 752                        return -1;
 753                } else {
 754                        ide_debug_log(IDE_DBG_FUNC, "Block Location: %u",
 755                                      be32_to_cpup((__be32 *)&buf[4]));
 756
 757                        tape->partition = buf[1];
 758                        tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
 759                        set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
 760                                &drive->atapi_flags);
 761                }
 762        }
 763
 764        return tape->first_frame;
 765}
 766
 767static void idetape_create_locate_cmd(ide_drive_t *drive,
 768                struct ide_atapi_pc *pc,
 769                unsigned int block, u8 partition, int skip)
 770{
 771        ide_init_pc(pc);
 772        pc->c[0] = POSITION_TO_ELEMENT;
 773        pc->c[1] = 2;
 774        put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
 775        pc->c[8] = partition;
 776        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 777}
 778
 779static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 780{
 781        idetape_tape_t *tape = drive->driver_data;
 782
 783        if (tape->chrdev_dir != IDETAPE_DIR_READ)
 784                return;
 785
 786        clear_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
 787        tape->valid = 0;
 788        if (tape->buf != NULL) {
 789                kfree(tape->buf);
 790                tape->buf = NULL;
 791        }
 792
 793        tape->chrdev_dir = IDETAPE_DIR_NONE;
 794}
 795
 796/*
 797 * Position the tape to the requested block using the LOCATE packet command.
 798 * A READ POSITION command is then issued to check where we are positioned. Like
 799 * all higher level operations, we queue the commands at the tail of the request
 800 * queue and wait for their completion.
 801 */
 802static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 803                u8 partition, int skip)
 804{
 805        idetape_tape_t *tape = drive->driver_data;
 806        struct gendisk *disk = tape->disk;
 807        int ret;
 808        struct ide_atapi_pc pc;
 809
 810        if (tape->chrdev_dir == IDETAPE_DIR_READ)
 811                __ide_tape_discard_merge_buffer(drive);
 812        idetape_wait_ready(drive, 60 * 5 * HZ);
 813        idetape_create_locate_cmd(drive, &pc, block, partition, skip);
 814        ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 815        if (ret)
 816                return ret;
 817
 818        ret = ide_tape_read_position(drive);
 819        if (ret < 0)
 820                return ret;
 821        return 0;
 822}
 823
 824static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
 825                                          int restore_position)
 826{
 827        idetape_tape_t *tape = drive->driver_data;
 828        int seek, position;
 829
 830        __ide_tape_discard_merge_buffer(drive);
 831        if (restore_position) {
 832                position = ide_tape_read_position(drive);
 833                seek = position > 0 ? position : 0;
 834                if (idetape_position_tape(drive, seek, 0, 0)) {
 835                        printk(KERN_INFO "ide-tape: %s: position_tape failed in"
 836                                         " %s\n", tape->name, __func__);
 837                        return;
 838                }
 839        }
 840}
 841
 842/*
 843 * Generate a read/write request for the block device interface and wait for it
 844 * to be serviced.
 845 */
 846static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 847{
 848        idetape_tape_t *tape = drive->driver_data;
 849        struct request *rq;
 850        int ret;
 851
 852        ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, size: %d", cmd, size);
 853
 854        BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
 855        BUG_ON(size < 0 || size % tape->blk_size);
 856
 857        rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
 858        ide_req(rq)->type = ATA_PRIV_MISC;
 859        scsi_req(rq)->cmd[13] = cmd;
 860        rq->rq_disk = tape->disk;
 861        rq->__sector = tape->first_frame;
 862
 863        if (size) {
 864                ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
 865                                      GFP_NOIO);
 866                if (ret)
 867                        goto out_put;
 868        }
 869
 870        blk_execute_rq(drive->queue, tape->disk, rq, 0);
 871
 872        /* calculate the number of transferred bytes and update buffer state */
 873        size -= scsi_req(rq)->resid_len;
 874        tape->cur = tape->buf;
 875        if (cmd == REQ_IDETAPE_READ)
 876                tape->valid = size;
 877        else
 878                tape->valid = 0;
 879
 880        ret = size;
 881        if (scsi_req(rq)->result == IDE_DRV_ERROR_GENERAL)
 882                ret = -EIO;
 883out_put:
 884        blk_put_request(rq);
 885        return ret;
 886}
 887
 888static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 889{
 890        ide_init_pc(pc);
 891        pc->c[0] = INQUIRY;
 892        pc->c[4] = 254;
 893        pc->req_xfer = 254;
 894}
 895
 896static void idetape_create_rewind_cmd(ide_drive_t *drive,
 897                struct ide_atapi_pc *pc)
 898{
 899        ide_init_pc(pc);
 900        pc->c[0] = REZERO_UNIT;
 901        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 902}
 903
 904static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 905{
 906        ide_init_pc(pc);
 907        pc->c[0] = ERASE;
 908        pc->c[1] = 1;
 909        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 910}
 911
 912static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 913{
 914        ide_init_pc(pc);
 915        pc->c[0] = SPACE;
 916        put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
 917        pc->c[1] = cmd;
 918        pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 919}
 920
 921static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 922{
 923        idetape_tape_t *tape = drive->driver_data;
 924
 925        if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
 926                printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
 927                                " but we are not writing.\n");
 928                return;
 929        }
 930        if (tape->buf) {
 931                size_t aligned = roundup(tape->valid, tape->blk_size);
 932
 933                memset(tape->cur, 0, aligned - tape->valid);
 934                idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
 935                kfree(tape->buf);
 936                tape->buf = NULL;
 937        }
 938        tape->chrdev_dir = IDETAPE_DIR_NONE;
 939}
 940
 941static int idetape_init_rw(ide_drive_t *drive, int dir)
 942{
 943        idetape_tape_t *tape = drive->driver_data;
 944        int rc;
 945
 946        BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 947
 948        if (tape->chrdev_dir == dir)
 949                return 0;
 950
 951        if (tape->chrdev_dir == IDETAPE_DIR_READ)
 952                ide_tape_discard_merge_buffer(drive, 1);
 953        else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
 954                ide_tape_flush_merge_buffer(drive);
 955                idetape_flush_tape_buffers(drive);
 956        }
 957
 958        if (tape->buf || tape->valid) {
 959                printk(KERN_ERR "ide-tape: valid should be 0 now\n");
 960                tape->valid = 0;
 961        }
 962
 963        tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
 964        if (!tape->buf)
 965                return -ENOMEM;
 966        tape->chrdev_dir = dir;
 967        tape->cur = tape->buf;
 968
 969        /*
 970         * Issue a 0 rw command to ensure that DSC handshake is
 971         * switched from completion mode to buffer available mode.  No
 972         * point in issuing this if DSC overlap isn't supported, some
 973         * drives (Seagate STT3401A) will return an error.
 974         */
 975        if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
 976                int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
 977                                                  : REQ_IDETAPE_WRITE;
 978
 979                rc = idetape_queue_rw_tail(drive, cmd, 0);
 980                if (rc < 0) {
 981                        kfree(tape->buf);
 982                        tape->buf = NULL;
 983                        tape->chrdev_dir = IDETAPE_DIR_NONE;
 984                        return rc;
 985                }
 986        }
 987
 988        return 0;
 989}
 990
 991static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
 992{
 993        idetape_tape_t *tape = drive->driver_data;
 994
 995        memset(tape->buf, 0, tape->buffer_size);
 996
 997        while (bcount) {
 998                unsigned int count = min(tape->buffer_size, bcount);
 999
1000                idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1001                bcount -= count;
1002        }
1003}
1004
1005/*
1006 * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1007 * currently support only one partition.
1008 */
1009static int idetape_rewind_tape(ide_drive_t *drive)
1010{
1011        struct ide_tape_obj *tape = drive->driver_data;
1012        struct gendisk *disk = tape->disk;
1013        struct ide_atapi_pc pc;
1014        int ret;
1015
1016        ide_debug_log(IDE_DBG_FUNC, "enter");
1017
1018        idetape_create_rewind_cmd(drive, &pc);
1019        ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1020        if (ret)
1021                return ret;
1022
1023        ret = ide_tape_read_position(drive);
1024        if (ret < 0)
1025                return ret;
1026        return 0;
1027}
1028
1029/* mtio.h compatible commands should be issued to the chrdev interface. */
1030static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1031                                unsigned long arg)
1032{
1033        idetape_tape_t *tape = drive->driver_data;
1034        void __user *argp = (void __user *)arg;
1035
1036        struct idetape_config {
1037                int dsc_rw_frequency;
1038                int dsc_media_access_frequency;
1039                int nr_stages;
1040        } config;
1041
1042        ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%04x", cmd);
1043
1044        switch (cmd) {
1045        case 0x0340:
1046                if (copy_from_user(&config, argp, sizeof(config)))
1047                        return -EFAULT;
1048                tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1049                break;
1050        case 0x0350:
1051                memset(&config, 0, sizeof(config));
1052                config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1053                config.nr_stages = 1;
1054                if (copy_to_user(argp, &config, sizeof(config)))
1055                        return -EFAULT;
1056                break;
1057        default:
1058                return -EIO;
1059        }
1060        return 0;
1061}
1062
1063static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1064                                        int mt_count)
1065{
1066        idetape_tape_t *tape = drive->driver_data;
1067        struct gendisk *disk = tape->disk;
1068        struct ide_atapi_pc pc;
1069        int retval, count = 0;
1070        int sprev = !!(tape->caps[4] & 0x20);
1071
1072
1073        ide_debug_log(IDE_DBG_FUNC, "mt_op: %d, mt_count: %d", mt_op, mt_count);
1074
1075        if (mt_count == 0)
1076                return 0;
1077        if (MTBSF == mt_op || MTBSFM == mt_op) {
1078                if (!sprev)
1079                        return -EIO;
1080                mt_count = -mt_count;
1081        }
1082
1083        if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1084                tape->valid = 0;
1085                if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1086                                       &drive->atapi_flags))
1087                        ++count;
1088                ide_tape_discard_merge_buffer(drive, 0);
1089        }
1090
1091        switch (mt_op) {
1092        case MTFSF:
1093        case MTBSF:
1094                idetape_create_space_cmd(&pc, mt_count - count,
1095                                         IDETAPE_SPACE_OVER_FILEMARK);
1096                return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1097        case MTFSFM:
1098        case MTBSFM:
1099                if (!sprev)
1100                        return -EIO;
1101                retval = idetape_space_over_filemarks(drive, MTFSF,
1102                                                      mt_count - count);
1103                if (retval)
1104                        return retval;
1105                count = (MTBSFM == mt_op ? 1 : -1);
1106                return idetape_space_over_filemarks(drive, MTFSF, count);
1107        default:
1108                printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1109                                mt_op);
1110                return -EIO;
1111        }
1112}
1113
1114/*
1115 * Our character device read / write functions.
1116 *
1117 * The tape is optimized to maximize throughput when it is transferring an
1118 * integral number of the "continuous transfer limit", which is a parameter of
1119 * the specific tape (26kB on my particular tape, 32kB for Onstream).
1120 *
1121 * As of version 1.3 of the driver, the character device provides an abstract
1122 * continuous view of the media - any mix of block sizes (even 1 byte) on the
1123 * same backup/restore procedure is supported. The driver will internally
1124 * convert the requests to the recommended transfer unit, so that an unmatch
1125 * between the user's block size to the recommended size will only result in a
1126 * (slightly) increased driver overhead, but will no longer hit performance.
1127 * This is not applicable to Onstream.
1128 */
1129static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1130                                   size_t count, loff_t *ppos)
1131{
1132        struct ide_tape_obj *tape = file->private_data;
1133        ide_drive_t *drive = tape->drive;
1134        size_t done = 0;
1135        ssize_t ret = 0;
1136        int rc;
1137
1138        ide_debug_log(IDE_DBG_FUNC, "count %zd", count);
1139
1140        if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1141                if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1142                        if (count > tape->blk_size &&
1143                            (count % tape->blk_size) == 0)
1144                                tape->user_bs_factor = count / tape->blk_size;
1145        }
1146
1147        rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1148        if (rc < 0)
1149                return rc;
1150
1151        while (done < count) {
1152                size_t todo;
1153
1154                /* refill if staging buffer is empty */
1155                if (!tape->valid) {
1156                        /* If we are at a filemark, nothing more to read */
1157                        if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1158                                     &drive->atapi_flags))
1159                                break;
1160                        /* read */
1161                        if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1162                                                  tape->buffer_size) <= 0)
1163                                break;
1164                }
1165
1166                /* copy out */
1167                todo = min_t(size_t, count - done, tape->valid);
1168                if (copy_to_user(buf + done, tape->cur, todo))
1169                        ret = -EFAULT;
1170
1171                tape->cur += todo;
1172                tape->valid -= todo;
1173                done += todo;
1174        }
1175
1176        if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1177                idetape_space_over_filemarks(drive, MTFSF, 1);
1178                return 0;
1179        }
1180
1181        return ret ? ret : done;
1182}
1183
1184static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1185                                     size_t count, loff_t *ppos)
1186{
1187        struct ide_tape_obj *tape = file->private_data;
1188        ide_drive_t *drive = tape->drive;
1189        size_t done = 0;
1190        ssize_t ret = 0;
1191        int rc;
1192
1193        /* The drive is write protected. */
1194        if (tape->write_prot)
1195                return -EACCES;
1196
1197        ide_debug_log(IDE_DBG_FUNC, "count %zd", count);
1198
1199        /* Initialize write operation */
1200        rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1201        if (rc < 0)
1202                return rc;
1203
1204        while (done < count) {
1205                size_t todo;
1206
1207                /* flush if staging buffer is full */
1208                if (tape->valid == tape->buffer_size &&
1209                    idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1210                                          tape->buffer_size) <= 0)
1211                        return rc;
1212
1213                /* copy in */
1214                todo = min_t(size_t, count - done,
1215                             tape->buffer_size - tape->valid);
1216                if (copy_from_user(tape->cur, buf + done, todo))
1217                        ret = -EFAULT;
1218
1219                tape->cur += todo;
1220                tape->valid += todo;
1221                done += todo;
1222        }
1223
1224        return ret ? ret : done;
1225}
1226
1227static int idetape_write_filemark(ide_drive_t *drive)
1228{
1229        struct ide_tape_obj *tape = drive->driver_data;
1230        struct ide_atapi_pc pc;
1231
1232        /* Write a filemark */
1233        idetape_create_write_filemark_cmd(drive, &pc, 1);
1234        if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1235                printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1236                return -EIO;
1237        }
1238        return 0;
1239}
1240
1241/*
1242 * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1243 * requested.
1244 *
1245 * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1246 * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1247 * usually not supported.
1248 *
1249 * The following commands are currently not supported:
1250 *
1251 * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1252 * MT_ST_WRITE_THRESHOLD.
1253 */
1254static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1255{
1256        idetape_tape_t *tape = drive->driver_data;
1257        struct gendisk *disk = tape->disk;
1258        struct ide_atapi_pc pc;
1259        int i, retval;
1260
1261        ide_debug_log(IDE_DBG_FUNC, "MTIOCTOP ioctl: mt_op: %d, mt_count: %d",
1262                      mt_op, mt_count);
1263
1264        switch (mt_op) {
1265        case MTFSF:
1266        case MTFSFM:
1267        case MTBSF:
1268        case MTBSFM:
1269                if (!mt_count)
1270                        return 0;
1271                return idetape_space_over_filemarks(drive, mt_op, mt_count);
1272        default:
1273                break;
1274        }
1275
1276        switch (mt_op) {
1277        case MTWEOF:
1278                if (tape->write_prot)
1279                        return -EACCES;
1280                ide_tape_discard_merge_buffer(drive, 1);
1281                for (i = 0; i < mt_count; i++) {
1282                        retval = idetape_write_filemark(drive);
1283                        if (retval)
1284                                return retval;
1285                }
1286                return 0;
1287        case MTREW:
1288                ide_tape_discard_merge_buffer(drive, 0);
1289                if (idetape_rewind_tape(drive))
1290                        return -EIO;
1291                return 0;
1292        case MTLOAD:
1293                ide_tape_discard_merge_buffer(drive, 0);
1294                return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1295        case MTUNLOAD:
1296        case MTOFFL:
1297                /*
1298                 * If door is locked, attempt to unlock before
1299                 * attempting to eject.
1300                 */
1301                if (tape->door_locked) {
1302                        if (!ide_set_media_lock(drive, disk, 0))
1303                                tape->door_locked = DOOR_UNLOCKED;
1304                }
1305                ide_tape_discard_merge_buffer(drive, 0);
1306                retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1307                if (!retval)
1308                        clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1309                                  &drive->atapi_flags);
1310                return retval;
1311        case MTNOP:
1312                ide_tape_discard_merge_buffer(drive, 0);
1313                return idetape_flush_tape_buffers(drive);
1314        case MTRETEN:
1315                ide_tape_discard_merge_buffer(drive, 0);
1316                return ide_do_start_stop(drive, disk,
1317                        IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1318        case MTEOM:
1319                idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1320                return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1321        case MTERASE:
1322                (void)idetape_rewind_tape(drive);
1323                idetape_create_erase_cmd(&pc);
1324                return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1325        case MTSETBLK:
1326                if (mt_count) {
1327                        if (mt_count < tape->blk_size ||
1328                            mt_count % tape->blk_size)
1329                                return -EIO;
1330                        tape->user_bs_factor = mt_count / tape->blk_size;
1331                        clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1332                                  &drive->atapi_flags);
1333                } else
1334                        set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1335                                &drive->atapi_flags);
1336                return 0;
1337        case MTSEEK:
1338                ide_tape_discard_merge_buffer(drive, 0);
1339                return idetape_position_tape(drive,
1340                        mt_count * tape->user_bs_factor, tape->partition, 0);
1341        case MTSETPART:
1342                ide_tape_discard_merge_buffer(drive, 0);
1343                return idetape_position_tape(drive, 0, mt_count, 0);
1344        case MTFSR:
1345        case MTBSR:
1346        case MTLOCK:
1347                retval = ide_set_media_lock(drive, disk, 1);
1348                if (retval)
1349                        return retval;
1350                tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1351                return 0;
1352        case MTUNLOCK:
1353                retval = ide_set_media_lock(drive, disk, 0);
1354                if (retval)
1355                        return retval;
1356                tape->door_locked = DOOR_UNLOCKED;
1357                return 0;
1358        default:
1359                printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1360                                mt_op);
1361                return -EIO;
1362        }
1363}
1364
1365/*
1366 * Our character device ioctls. General mtio.h magnetic io commands are
1367 * supported here, and not in the corresponding block interface. Our own
1368 * ide-tape ioctls are supported on both interfaces.
1369 */
1370static long do_idetape_chrdev_ioctl(struct file *file,
1371                                unsigned int cmd, unsigned long arg)
1372{
1373        struct ide_tape_obj *tape = file->private_data;
1374        ide_drive_t *drive = tape->drive;
1375        struct mtop mtop;
1376        struct mtget mtget;
1377        struct mtpos mtpos;
1378        int block_offset = 0, position = tape->first_frame;
1379        void __user *argp = (void __user *)arg;
1380
1381        ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x", cmd);
1382
1383        if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1384                ide_tape_flush_merge_buffer(drive);
1385                idetape_flush_tape_buffers(drive);
1386        }
1387        if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1388                block_offset = tape->valid /
1389                        (tape->blk_size * tape->user_bs_factor);
1390                position = ide_tape_read_position(drive);
1391                if (position < 0)
1392                        return -EIO;
1393        }
1394        switch (cmd) {
1395        case MTIOCTOP:
1396                if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1397                        return -EFAULT;
1398                return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1399        case MTIOCGET:
1400                memset(&mtget, 0, sizeof(struct mtget));
1401                mtget.mt_type = MT_ISSCSI2;
1402                mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1403                mtget.mt_dsreg =
1404                        ((tape->blk_size * tape->user_bs_factor)
1405                         << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1406
1407                if (tape->drv_write_prot)
1408                        mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1409
1410                if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1411                        return -EFAULT;
1412                return 0;
1413        case MTIOCPOS:
1414                mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1415                if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1416                        return -EFAULT;
1417                return 0;
1418        default:
1419                if (tape->chrdev_dir == IDETAPE_DIR_READ)
1420                        ide_tape_discard_merge_buffer(drive, 1);
1421                return idetape_blkdev_ioctl(drive, cmd, arg);
1422        }
1423}
1424
1425static long idetape_chrdev_ioctl(struct file *file,
1426                                unsigned int cmd, unsigned long arg)
1427{
1428        long ret;
1429        mutex_lock(&ide_tape_mutex);
1430        ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1431        mutex_unlock(&ide_tape_mutex);
1432        return ret;
1433}
1434
1435/*
1436 * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1437 * block size with the reported value.
1438 */
1439static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1440{
1441        idetape_tape_t *tape = drive->driver_data;
1442        struct ide_atapi_pc pc;
1443        u8 buf[12];
1444
1445        idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1446        if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1447                printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1448                if (tape->blk_size == 0) {
1449                        printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1450                                            "block size, assuming 32k\n");
1451                        tape->blk_size = 32768;
1452                }
1453                return;
1454        }
1455        tape->blk_size = (buf[4 + 5] << 16) +
1456                                (buf[4 + 6] << 8)  +
1457                                 buf[4 + 7];
1458        tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1459
1460        ide_debug_log(IDE_DBG_FUNC, "blk_size: %d, write_prot: %d",
1461                      tape->blk_size, tape->drv_write_prot);
1462}
1463
1464static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1465{
1466        unsigned int minor = iminor(inode), i = minor & ~0xc0;
1467        ide_drive_t *drive;
1468        idetape_tape_t *tape;
1469        int retval;
1470
1471        if (i >= MAX_HWIFS * MAX_DRIVES)
1472                return -ENXIO;
1473
1474        mutex_lock(&idetape_chrdev_mutex);
1475
1476        tape = ide_tape_get(NULL, true, i);
1477        if (!tape) {
1478                mutex_unlock(&idetape_chrdev_mutex);
1479                return -ENXIO;
1480        }
1481
1482        drive = tape->drive;
1483        filp->private_data = tape;
1484
1485        ide_debug_log(IDE_DBG_FUNC, "enter");
1486
1487        /*
1488         * We really want to do nonseekable_open(inode, filp); here, but some
1489         * versions of tar incorrectly call lseek on tapes and bail out if that
1490         * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1491         */
1492        filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1493
1494
1495        if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1496                retval = -EBUSY;
1497                goto out_put_tape;
1498        }
1499
1500        retval = idetape_wait_ready(drive, 60 * HZ);
1501        if (retval) {
1502                clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1503                printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1504                goto out_put_tape;
1505        }
1506
1507        ide_tape_read_position(drive);
1508        if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1509                (void)idetape_rewind_tape(drive);
1510
1511        /* Read block size and write protect status from drive. */
1512        ide_tape_get_bsize_from_bdesc(drive);
1513
1514        /* Set write protect flag if device is opened as read-only. */
1515        if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1516                tape->write_prot = 1;
1517        else
1518                tape->write_prot = tape->drv_write_prot;
1519
1520        /* Make sure drive isn't write protected if user wants to write. */
1521        if (tape->write_prot) {
1522                if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1523                    (filp->f_flags & O_ACCMODE) == O_RDWR) {
1524                        clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1525                        retval = -EROFS;
1526                        goto out_put_tape;
1527                }
1528        }
1529
1530        /* Lock the tape drive door so user can't eject. */
1531        if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1532                if (!ide_set_media_lock(drive, tape->disk, 1)) {
1533                        if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1534                                tape->door_locked = DOOR_LOCKED;
1535                }
1536        }
1537        mutex_unlock(&idetape_chrdev_mutex);
1538
1539        return 0;
1540
1541out_put_tape:
1542        ide_tape_put(tape);
1543
1544        mutex_unlock(&idetape_chrdev_mutex);
1545
1546        return retval;
1547}
1548
1549static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1550{
1551        idetape_tape_t *tape = drive->driver_data;
1552
1553        ide_tape_flush_merge_buffer(drive);
1554        tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1555        if (tape->buf != NULL) {
1556                idetape_pad_zeros(drive, tape->blk_size *
1557                                (tape->user_bs_factor - 1));
1558                kfree(tape->buf);
1559                tape->buf = NULL;
1560        }
1561        idetape_write_filemark(drive);
1562        idetape_flush_tape_buffers(drive);
1563        idetape_flush_tape_buffers(drive);
1564}
1565
1566static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1567{
1568        struct ide_tape_obj *tape = filp->private_data;
1569        ide_drive_t *drive = tape->drive;
1570        unsigned int minor = iminor(inode);
1571
1572        mutex_lock(&idetape_chrdev_mutex);
1573
1574        tape = drive->driver_data;
1575
1576        ide_debug_log(IDE_DBG_FUNC, "enter");
1577
1578        if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1579                idetape_write_release(drive, minor);
1580        if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1581                if (minor < 128)
1582                        ide_tape_discard_merge_buffer(drive, 1);
1583        }
1584
1585        if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1586                                    &drive->atapi_flags))
1587                (void) idetape_rewind_tape(drive);
1588
1589        if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1590                if (tape->door_locked == DOOR_LOCKED) {
1591                        if (!ide_set_media_lock(drive, tape->disk, 0))
1592                                tape->door_locked = DOOR_UNLOCKED;
1593                }
1594        }
1595        clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1596        ide_tape_put(tape);
1597
1598        mutex_unlock(&idetape_chrdev_mutex);
1599
1600        return 0;
1601}
1602
1603static void idetape_get_inquiry_results(ide_drive_t *drive)
1604{
1605        idetape_tape_t *tape = drive->driver_data;
1606        struct ide_atapi_pc pc;
1607        u8 pc_buf[256];
1608        char fw_rev[4], vendor_id[8], product_id[16];
1609
1610        idetape_create_inquiry_cmd(&pc);
1611        if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1612                printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1613                                tape->name);
1614                return;
1615        }
1616        memcpy(vendor_id, &pc_buf[8], 8);
1617        memcpy(product_id, &pc_buf[16], 16);
1618        memcpy(fw_rev, &pc_buf[32], 4);
1619
1620        ide_fixstring(vendor_id, 8, 0);
1621        ide_fixstring(product_id, 16, 0);
1622        ide_fixstring(fw_rev, 4, 0);
1623
1624        printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1625                        drive->name, tape->name, vendor_id, product_id, fw_rev);
1626}
1627
1628/*
1629 * Ask the tape about its various parameters. In particular, we will adjust our
1630 * data transfer buffer size to the recommended value as returned by the tape.
1631 */
1632static void idetape_get_mode_sense_results(ide_drive_t *drive)
1633{
1634        idetape_tape_t *tape = drive->driver_data;
1635        struct ide_atapi_pc pc;
1636        u8 buf[24], *caps;
1637        u8 speed, max_speed;
1638
1639        idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1640        if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1641                printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1642                                " some default values\n");
1643                tape->blk_size = 512;
1644                put_unaligned(52,   (u16 *)&tape->caps[12]);
1645                put_unaligned(540,  (u16 *)&tape->caps[14]);
1646                put_unaligned(6*52, (u16 *)&tape->caps[16]);
1647                return;
1648        }
1649        caps = buf + 4 + buf[3];
1650
1651        /* convert to host order and save for later use */
1652        speed = be16_to_cpup((__be16 *)&caps[14]);
1653        max_speed = be16_to_cpup((__be16 *)&caps[8]);
1654
1655        *(u16 *)&caps[8] = max_speed;
1656        *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1657        *(u16 *)&caps[14] = speed;
1658        *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1659
1660        if (!speed) {
1661                printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1662                                "(assuming 650KB/sec)\n", drive->name);
1663                *(u16 *)&caps[14] = 650;
1664        }
1665        if (!max_speed) {
1666                printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1667                                "(assuming 650KB/sec)\n", drive->name);
1668                *(u16 *)&caps[8] = 650;
1669        }
1670
1671        memcpy(&tape->caps, caps, 20);
1672
1673        /* device lacks locking support according to capabilities page */
1674        if ((caps[6] & 1) == 0)
1675                drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1676
1677        if (caps[7] & 0x02)
1678                tape->blk_size = 512;
1679        else if (caps[7] & 0x04)
1680                tape->blk_size = 1024;
1681}
1682
1683#ifdef CONFIG_IDE_PROC_FS
1684#define ide_tape_devset_get(name, field) \
1685static int get_##name(ide_drive_t *drive) \
1686{ \
1687        idetape_tape_t *tape = drive->driver_data; \
1688        return tape->field; \
1689}
1690
1691#define ide_tape_devset_set(name, field) \
1692static int set_##name(ide_drive_t *drive, int arg) \
1693{ \
1694        idetape_tape_t *tape = drive->driver_data; \
1695        tape->field = arg; \
1696        return 0; \
1697}
1698
1699#define ide_tape_devset_rw_field(_name, _field) \
1700ide_tape_devset_get(_name, _field) \
1701ide_tape_devset_set(_name, _field) \
1702IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1703
1704#define ide_tape_devset_r_field(_name, _field) \
1705ide_tape_devset_get(_name, _field) \
1706IDE_DEVSET(_name, 0, get_##_name, NULL)
1707
1708static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1709static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1710static int divf_buffer(ide_drive_t *drive)      { return    2; }
1711static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1712
1713ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1714
1715ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1716
1717ide_tape_devset_r_field(avg_speed, avg_speed);
1718ide_tape_devset_r_field(speed, caps[14]);
1719ide_tape_devset_r_field(buffer, caps[16]);
1720ide_tape_devset_r_field(buffer_size, buffer_size);
1721
1722static const struct ide_proc_devset idetape_settings[] = {
1723        __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1724        __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1725        __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1726        __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1727        __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1728        __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1729                                        mulf_tdsc, divf_tdsc),
1730        { NULL },
1731};
1732#endif
1733
1734/*
1735 * The function below is called to:
1736 *
1737 * 1. Initialize our various state variables.
1738 * 2. Ask the tape for its capabilities.
1739 * 3. Allocate a buffer which will be used for data transfer. The buffer size
1740 * is chosen based on the recommendation which we received in step 2.
1741 *
1742 * Note that at this point ide.c already assigned us an irq, so that we can
1743 * queue requests here and wait for their completion.
1744 */
1745static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1746{
1747        unsigned long t;
1748        int speed;
1749        u16 *ctl = (u16 *)&tape->caps[12];
1750
1751        ide_debug_log(IDE_DBG_FUNC, "minor: %d", minor);
1752
1753        drive->pc_callback = ide_tape_callback;
1754
1755        drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1756
1757        if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1758                printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1759                                 tape->name);
1760                drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1761        }
1762
1763        /* Seagate Travan drives do not support DSC overlap. */
1764        if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1765                drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1766
1767        tape->minor = minor;
1768        tape->name[0] = 'h';
1769        tape->name[1] = 't';
1770        tape->name[2] = '0' + minor;
1771        tape->chrdev_dir = IDETAPE_DIR_NONE;
1772
1773        idetape_get_inquiry_results(drive);
1774        idetape_get_mode_sense_results(drive);
1775        ide_tape_get_bsize_from_bdesc(drive);
1776        tape->user_bs_factor = 1;
1777        tape->buffer_size = *ctl * tape->blk_size;
1778        while (tape->buffer_size > 0xffff) {
1779                printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1780                *ctl /= 2;
1781                tape->buffer_size = *ctl * tape->blk_size;
1782        }
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                "%ums 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                jiffies_to_msecs(tape->best_dsc_rw_freq),
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 ide_proc_entry_t idetape_proc[] = {
1849        { "capacity",   S_IFREG|S_IRUGO,        ide_capacity_proc_show  },
1850        { "name",       S_IFREG|S_IRUGO,        idetape_name_proc_show  },
1851        {}
1852};
1853
1854static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1855{
1856        return idetape_proc;
1857}
1858
1859static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1860{
1861        return idetape_settings;
1862}
1863#endif
1864
1865static int ide_tape_probe(ide_drive_t *);
1866
1867static struct ide_driver idetape_driver = {
1868        .gen_driver = {
1869                .owner          = THIS_MODULE,
1870                .name           = "ide-tape",
1871                .bus            = &ide_bus_type,
1872        },
1873        .probe                  = ide_tape_probe,
1874        .remove                 = ide_tape_remove,
1875        .version                = IDETAPE_VERSION,
1876        .do_request             = idetape_do_request,
1877#ifdef CONFIG_IDE_PROC_FS
1878        .proc_entries           = ide_tape_proc_entries,
1879        .proc_devsets           = ide_tape_proc_devsets,
1880#endif
1881};
1882
1883/* Our character device supporting functions, passed to register_chrdev. */
1884static const struct file_operations idetape_fops = {
1885        .owner          = THIS_MODULE,
1886        .read           = idetape_chrdev_read,
1887        .write          = idetape_chrdev_write,
1888        .unlocked_ioctl = idetape_chrdev_ioctl,
1889        .open           = idetape_chrdev_open,
1890        .release        = idetape_chrdev_release,
1891        .llseek         = noop_llseek,
1892};
1893
1894static int idetape_open(struct block_device *bdev, fmode_t mode)
1895{
1896        struct ide_tape_obj *tape;
1897
1898        mutex_lock(&ide_tape_mutex);
1899        tape = ide_tape_get(bdev->bd_disk, false, 0);
1900        mutex_unlock(&ide_tape_mutex);
1901
1902        if (!tape)
1903                return -ENXIO;
1904
1905        return 0;
1906}
1907
1908static void idetape_release(struct gendisk *disk, fmode_t mode)
1909{
1910        struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1911
1912        mutex_lock(&ide_tape_mutex);
1913        ide_tape_put(tape);
1914        mutex_unlock(&ide_tape_mutex);
1915}
1916
1917static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1918                        unsigned int cmd, unsigned long arg)
1919{
1920        struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1921        ide_drive_t *drive = tape->drive;
1922        int err;
1923
1924        mutex_lock(&ide_tape_mutex);
1925        err = generic_ide_ioctl(drive, bdev, cmd, arg);
1926        if (err == -EINVAL)
1927                err = idetape_blkdev_ioctl(drive, cmd, arg);
1928        mutex_unlock(&ide_tape_mutex);
1929
1930        return err;
1931}
1932
1933static const struct block_device_operations idetape_block_ops = {
1934        .owner          = THIS_MODULE,
1935        .open           = idetape_open,
1936        .release        = idetape_release,
1937        .ioctl          = idetape_ioctl,
1938};
1939
1940static int ide_tape_probe(ide_drive_t *drive)
1941{
1942        idetape_tape_t *tape;
1943        struct gendisk *g;
1944        int minor;
1945
1946        ide_debug_log(IDE_DBG_FUNC, "enter");
1947
1948        if (!strstr(DRV_NAME, 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, "%s", 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
2007out_free_disk:
2008        put_disk(g);
2009out_free_tape:
2010        kfree(tape);
2011failed:
2012        return -ENODEV;
2013}
2014
2015static 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
2022static 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_chrdev;
2043
2044        return 0;
2045
2046out_free_chrdev:
2047        unregister_chrdev(IDETAPE_MAJOR, "ht");
2048out_free_class:
2049        class_destroy(idetape_sysfs_class);
2050out:
2051        return error;
2052}
2053
2054MODULE_ALIAS("ide:*m-tape*");
2055module_init(idetape_init);
2056module_exit(idetape_exit);
2057MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2058MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2059MODULE_LICENSE("GPL");
2060