drivers/ide/ide-tape.c

   1 /*
   2  * IDE ATAPI streaming tape driver.
   3  *
   4  * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
   5  * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
   6  *
   7  * This driver was constructed as a student project in the software laboratory
   8  * of the faculty of electrical engineering in the Technion - Israel's
   9  * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
  10  *
  11  * It is hereby placed under the terms of the GNU general public license.
  12  * (See linux/COPYING).
  13  *
  14  * For a historical changelog see
  15  * Documentation/ide/ChangeLog.ide-tape.1995-2002
  16  */
  17
  18 #define IDETAPE_VERSION "1.19"
  19
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/string.h>
  23 #include <linux/kernel.h>
  24 #include <linux/delay.h>
  25 #include <linux/timer.h>
  26 #include <linux/mm.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/major.h>
  30 #include <linux/errno.h>
  31 #include <linux/genhd.h>
  32 #include <linux/slab.h>
  33 #include <linux/pci.h>
  34 #include <linux/ide.h>
  35 #include <linux/smp_lock.h>
  36 #include <linux/completion.h>
  37 #include <linux/bitops.h>
  38 #include <linux/mutex.h>
  39
  40 #include <asm/byteorder.h>
  41 #include <asm/irq.h>
  42 #include <asm/uaccess.h>
  43 #include <asm/io.h>
  44 #include <asm/unaligned.h>
  45
  46 /*
  47  * partition
  48  */
  49 typedef struct os_partition_s {
  50         __u8    partition_num;
  51         __u8    par_desc_ver;
  52         __u16   wrt_pass_cntr;
  53         __u32   first_frame_addr;
  54         __u32   last_frame_addr;
  55         __u32   eod_frame_addr;
  56 } os_partition_t;
  57
  58 /*
  59  * DAT entry
  60  */
  61 typedef struct os_dat_entry_s {
  62         __u32   blk_sz;
  63         __u16   blk_cnt;
  64         __u8    flags;
  65         __u8    reserved;
  66 } os_dat_entry_t;
  67
  68 /*
  69  * DAT
  70  */
  71 #define OS_DAT_FLAGS_DATA       (0xc)
  72 #define OS_DAT_FLAGS_MARK       (0x1)
  73
  74 typedef struct os_dat_s {
  75         __u8            dat_sz;
  76         __u8            reserved1;
  77         __u8            entry_cnt;
  78         __u8            reserved3;
  79         os_dat_entry_t  dat_list[16];
  80 } os_dat_t;
  81
  82 #include <linux/mtio.h>
  83
  84 /**************************** Tunable parameters *****************************/
  85
  86
  87 /*
  88  *      Pipelined mode parameters.
  89  *
  90  *      We try to use the minimum number of stages which is enough to
  91  *      keep the tape constantly streaming. To accomplish that, we implement
  92  *      a feedback loop around the maximum number of stages:
  93  *
  94  *      We start from MIN maximum stages (we will not even use MIN stages
  95  *      if we don't need them), increment it by RATE*(MAX-MIN)
  96  *      whenever we sense that the pipeline is empty, until we reach
  97  *      the optimum value or until we reach MAX.
  98  *
  99  *      Setting the following parameter to 0 is illegal: the pipelined mode
 100  *      cannot be disabled (calculate_speeds() divides by tape->max_stages.)
 101  */
 102 #define IDETAPE_MIN_PIPELINE_STAGES       1
 103 #define IDETAPE_MAX_PIPELINE_STAGES     400
 104 #define IDETAPE_INCREASE_STAGES_RATE     20
 105
 106 /*
 107  *      The following are used to debug the driver:
 108  *
 109  *      Setting IDETAPE_DEBUG_INFO to 1 will report device capabilities.
 110  *      Setting IDETAPE_DEBUG_LOG to 1 will log driver flow control.
 111  *      Setting IDETAPE_DEBUG_BUGS to 1 will enable self-sanity checks in
 112  *      some places.
 113  *
 114  *      Setting them to 0 will restore normal operation mode:
 115  *
 116  *              1.      Disable logging normal successful operations.
 117  *              2.      Disable self-sanity checks.
 118  *              3.      Errors will still be logged, of course.
 119  *
 120  *      All the #if DEBUG code will be removed some day, when the driver
 121  *      is verified to be stable enough. This will make it much more
 122  *      esthetic.
 123  */
 124 #define IDETAPE_DEBUG_INFO              0
 125 #define IDETAPE_DEBUG_LOG               0
 126 #define IDETAPE_DEBUG_BUGS              1
 127
 128 /*
 129  *      After each failed packet command we issue a request sense command
 130  *      and retry the packet command IDETAPE_MAX_PC_RETRIES times.
 131  *
 132  *      Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
 133  */
 134 #define IDETAPE_MAX_PC_RETRIES          3
 135
 136 /*
 137  *      With each packet command, we allocate a buffer of
 138  *      IDETAPE_PC_BUFFER_SIZE bytes. This is used for several packet
 139  *      commands (Not for READ/WRITE commands).
 140  */
 141 #define IDETAPE_PC_BUFFER_SIZE          256
 142
 143 /*
 144  *      In various places in the driver, we need to allocate storage
 145  *      for packet commands and requests, which will remain valid while
 146  *      we leave the driver to wait for an interrupt or a timeout event.
 147  */
 148 #define IDETAPE_PC_STACK                (10 + IDETAPE_MAX_PC_RETRIES)
 149
 150 /*
 151  * Some drives (for example, Seagate STT3401A Travan) require a very long
 152  * timeout, because they don't return an interrupt or clear their busy bit
 153  * until after the command completes (even retension commands).
 154  */
 155 #define IDETAPE_WAIT_CMD                (900*HZ)
 156
 157 /*
 158  *      The following parameter is used to select the point in the internal
 159  *      tape fifo in which we will start to refill the buffer. Decreasing
 160  *      the following parameter will improve the system's latency and
 161  *      interactive response, while using a high value might improve system
 162  *      throughput.
 163  */
 164 #define IDETAPE_FIFO_THRESHOLD          2
 165
 166 /*
 167  *      DSC polling parameters.
 168  *
 169  *      Polling for DSC (a single bit in the status register) is a very
 170  *      important function in ide-tape. There are two cases in which we
 171  *      poll for DSC:
 172  *
 173  *      1.      Before a read/write packet command, to ensure that we
 174  *              can transfer data from/to the tape's data buffers, without
 175  *              causing an actual media access. In case the tape is not
 176  *              ready yet, we take out our request from the device
 177  *              request queue, so that ide.c will service requests from
 178  *              the other device on the same interface meanwhile.
 179  *
 180  *      2.      After the successful initialization of a "media access
 181  *              packet command", which is a command which can take a long
 182  *              time to complete (it can be several seconds or even an hour).
 183  *
 184  *              Again, we postpone our request in the middle to free the bus
 185  *              for the other device. The polling frequency here should be
 186  *              lower than the read/write frequency since those media access
 187  *              commands are slow. We start from a "fast" frequency -
 188  *              IDETAPE_DSC_MA_FAST (one second), and if we don't receive DSC
 189  *              after IDETAPE_DSC_MA_THRESHOLD (5 minutes), we switch it to a
 190  *              lower frequency - IDETAPE_DSC_MA_SLOW (1 minute).
 191  *
 192  *      We also set a timeout for the timer, in case something goes wrong.
 193  *      The timeout should be longer then the maximum execution time of a
 194  *      tape operation.
 195  */
 196
 197 /*
 198  *      DSC timings.
 199  */
 200 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 201 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 202 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 203 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 204 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 205 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 206 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 207
 208 /*************************** End of tunable parameters ***********************/
 209
 210 /*
 211  *      Read/Write error simulation
 212  */
 213 #define SIMULATE_ERRORS                 0
 214
 215 /*
 216  *      For general magnetic tape device compatibility.
 217  */
 218 typedef enum {
 219         idetape_direction_none,
 220         idetape_direction_read,
 221         idetape_direction_write
 222 } idetape_chrdev_direction_t;
 223
 224 struct idetape_bh {
 225         u32 b_size;
 226         atomic_t b_count;
 227         struct idetape_bh *b_reqnext;
 228         char *b_data;
 229 };
 230
 231 /*
 232  *      Our view of a packet command.
 233  */
 234 typedef struct idetape_packet_command_s {
 235         u8 c[12];                               /* Actual packet bytes */
 236         int retries;                            /* On each retry, we increment retries */
 237         int error;                              /* Error code */
 238         int request_transfer;                   /* Bytes to transfer */
 239         int actually_transferred;               /* Bytes actually transferred */
 240         int buffer_size;                        /* Size of our data buffer */
 241         struct idetape_bh *bh;
 242         char *b_data;
 243         int b_count;
 244         u8 *buffer;                             /* Data buffer */
 245         u8 *current_position;                   /* Pointer into the above buffer */
 246         ide_startstop_t (*callback) (ide_drive_t *);    /* Called when this packet command is completed */
 247         u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE];   /* Temporary buffer */
 248         unsigned long flags;                    /* Status/Action bit flags: long for set_bit */
 249 } idetape_pc_t;
 250
 251 /*
 252  *      Packet command flag bits.
 253  */
 254 /* Set when an error is considered normal - We won't retry */
 255 #define PC_ABORT                        0
 256 /* 1 When polling for DSC on a media access command */
 257 #define PC_WAIT_FOR_DSC                 1
 258 /* 1 when we prefer to use DMA if possible */
 259 #define PC_DMA_RECOMMENDED              2
 260 /* 1 while DMA in progress */
 261 #define PC_DMA_IN_PROGRESS              3
 262 /* 1 when encountered problem during DMA */
 263 #define PC_DMA_ERROR                    4
 264 /* Data direction */
 265 #define PC_WRITING                      5
 266
 267 /*
 268  *      Capabilities and Mechanical Status Page
 269  */
 270 typedef struct {
 271         unsigned        page_code       :6;     /* Page code - Should be 0x2a */
 272         __u8            reserved0_6     :1;
 273         __u8            ps              :1;     /* parameters saveable */
 274         __u8            page_length;            /* Page Length - Should be 0x12 */
 275         __u8            reserved2, reserved3;
 276         unsigned        ro              :1;     /* Read Only Mode */
 277         unsigned        reserved4_1234  :4;
 278         unsigned        sprev           :1;     /* Supports SPACE in the reverse direction */
 279         unsigned        reserved4_67    :2;
 280         unsigned        reserved5_012   :3;
 281         unsigned        efmt            :1;     /* Supports ERASE command initiated formatting */
 282         unsigned        reserved5_4     :1;
 283         unsigned        qfa             :1;     /* Supports the QFA two partition formats */
 284         unsigned        reserved5_67    :2;
 285         unsigned        lock            :1;     /* Supports locking the volume */
 286         unsigned        locked          :1;     /* The volume is locked */
 287         unsigned        prevent         :1;     /* The device defaults in the prevent state after power up */
 288         unsigned        eject           :1;     /* The device can eject the volume */
 289         __u8            disconnect      :1;     /* The device can break request > ctl */
 290         __u8            reserved6_5     :1;
 291         unsigned        ecc             :1;     /* Supports error correction */
 292         unsigned        cmprs           :1;     /* Supports data compression */
 293         unsigned        reserved7_0     :1;
 294         unsigned        blk512          :1;     /* Supports 512 bytes block size */
 295         unsigned        blk1024         :1;     /* Supports 1024 bytes block size */
 296         unsigned        reserved7_3_6   :4;
 297         unsigned        blk32768        :1;     /* slowb - the device restricts the byte count for PIO */
 298                                                 /* transfers for slow buffer memory ??? */
 299                                                 /* Also 32768 block size in some cases */
 300         __u16           max_speed;              /* Maximum speed supported in KBps */
 301         __u8            reserved10, reserved11;
 302         __u16           ctl;                    /* Continuous Transfer Limit in blocks */
 303         __u16           speed;                  /* Current Speed, in KBps */
 304         __u16           buffer_size;            /* Buffer Size, in 512 bytes */
 305         __u8            reserved18, reserved19;
 306 } idetape_capabilities_page_t;
 307
 308 /*
 309  *      Block Size Page
 310  */
 311 typedef struct {
 312         unsigned        page_code       :6;     /* Page code - Should be 0x30 */
 313         unsigned        reserved1_6     :1;
 314         unsigned        ps              :1;
 315         __u8            page_length;            /* Page Length - Should be 2 */
 316         __u8            reserved2;
 317         unsigned        play32          :1;
 318         unsigned        play32_5        :1;
 319         unsigned        reserved2_23    :2;
 320         unsigned        record32        :1;
 321         unsigned        record32_5      :1;
 322         unsigned        reserved2_6     :1;
 323         unsigned        one             :1;
 324 } idetape_block_size_page_t;
 325
 326 /*
 327  *      A pipeline stage.
 328  */
 329 typedef struct idetape_stage_s {
 330         struct request rq;                      /* The corresponding request */
 331         struct idetape_bh *bh;                  /* The data buffers */
 332         struct idetape_stage_s *next;           /* Pointer to the next stage */
 333 } idetape_stage_t;
 334
 335 /*
 336  *      REQUEST SENSE packet command result - Data Format.
 337  */
 338 typedef struct {
 339         unsigned        error_code      :7;     /* Current of deferred errors */
 340         unsigned        valid           :1;     /* The information field conforms to QIC-157C */
 341         __u8            reserved1       :8;     /* Segment Number - Reserved */
 342         unsigned        sense_key       :4;     /* Sense Key */
 343         unsigned        reserved2_4     :1;     /* Reserved */
 344         unsigned        ili             :1;     /* Incorrect Length Indicator */
 345         unsigned        eom             :1;     /* End Of Medium */
 346         unsigned        filemark        :1;     /* Filemark */
 347         __u32           information __attribute__ ((packed));
 348         __u8            asl;                    /* Additional sense length (n-7) */
 349         __u32           command_specific;       /* Additional command specific information */
 350         __u8            asc;                    /* Additional Sense Code */
 351         __u8            ascq;                   /* Additional Sense Code Qualifier */
 352         __u8            replaceable_unit_code;  /* Field Replaceable Unit Code */
 353         unsigned        sk_specific1    :7;     /* Sense Key Specific */
 354         unsigned        sksv            :1;     /* Sense Key Specific information is valid */
 355         __u8            sk_specific2;           /* Sense Key Specific */
 356         __u8            sk_specific3;           /* Sense Key Specific */
 357         __u8            pad[2];                 /* Padding to 20 bytes */
 358 } idetape_request_sense_result_t;
 359
 360
 361 /*
 362  *      Most of our global data which we need to save even as we leave the
 363  *      driver due to an interrupt or a timer event is stored in a variable
 364  *      of type idetape_tape_t, defined below.
 365  */
 366 typedef struct ide_tape_obj {
 367         ide_drive_t     *drive;
 368         ide_driver_t    *driver;
 369         struct gendisk  *disk;
 370         struct kref     kref;
 371
 372         /*
 373          *      Since a typical character device operation requires more
 374          *      than one packet command, we provide here enough memory
 375          *      for the maximum of interconnected packet commands.
 376          *      The packet commands are stored in the circular array pc_stack.
 377          *      pc_stack_index points to the last used entry, and warps around
 378          *      to the start when we get to the last array entry.
 379          *
 380          *      pc points to the current processed packet command.
 381          *
 382          *      failed_pc points to the last failed packet command, or contains
 383          *      NULL if we do not need to retry any packet command. This is
 384          *      required since an additional packet command is needed before the
 385          *      retry, to get detailed information on what went wrong.
 386          */
 387         /* Current packet command */
 388         idetape_pc_t *pc;
 389         /* Last failed packet command */
 390         idetape_pc_t *failed_pc;
 391         /* Packet command stack */
 392         idetape_pc_t pc_stack[IDETAPE_PC_STACK];
 393         /* Next free packet command storage space */
 394         int pc_stack_index;
 395         struct request rq_stack[IDETAPE_PC_STACK];
 396         /* We implement a circular array */
 397         int rq_stack_index;
 398
 399         /*
 400          *      DSC polling variables.
 401          *
 402          *      While polling for DSC we use postponed_rq to postpone the
 403          *      current request so that ide.c will be able to service
 404          *      pending requests on the other device. Note that at most
 405          *      we will have only one DSC (usually data transfer) request
 406          *      in the device request queue. Additional requests can be
 407          *      queued in our internal pipeline, but they will be visible
 408          *      to ide.c only one at a time.
 409          */
 410         struct request *postponed_rq;
 411         /* The time in which we started polling for DSC */
 412         unsigned long dsc_polling_start;
 413         /* Timer used to poll for dsc */
 414         struct timer_list dsc_timer;
 415         /* Read/Write dsc polling frequency */
 416         unsigned long best_dsc_rw_frequency;
 417         /* The current polling frequency */
 418         unsigned long dsc_polling_frequency;
 419         /* Maximum waiting time */
 420         unsigned long dsc_timeout;
 421
 422         /*
 423          *      Read position information
 424          */
 425         u8 partition;
 426         /* Current block */
 427         unsigned int first_frame_position;
 428         unsigned int last_frame_position;
 429         unsigned int blocks_in_buffer;
 430
 431         /*
 432          *      Last error information
 433          */
 434         u8 sense_key, asc, ascq;
 435
 436         /*
 437          *      Character device operation
 438          */
 439         unsigned int minor;
 440         /* device name */
 441         char name[4];
 442         /* Current character device data transfer direction */
 443         idetape_chrdev_direction_t chrdev_direction;
 444
 445         /*
 446          *      Device information
 447          */
 448         /* Usually 512 or 1024 bytes */
 449         unsigned short tape_block_size;
 450         int user_bs_factor;
 451         /* Copy of the tape's Capabilities and Mechanical Page */
 452         idetape_capabilities_page_t capabilities;
 453
 454         /*
 455          *      Active data transfer request parameters.
 456          *
 457          *      At most, there is only one ide-tape originated data transfer
 458          *      request in the device request queue. This allows ide.c to
 459          *      easily service requests from the other device when we
 460          *      postpone our active request. In the pipelined operation
 461          *      mode, we use our internal pipeline structure to hold
 462          *      more data requests.
 463          *
 464          *      The data buffer size is chosen based on the tape's
 465          *      recommendation.
 466          */
 467         /* Pointer to the request which is waiting in the device request queue */
 468         struct request *active_data_request;
 469         /* Data buffer size (chosen based on the tape's recommendation */
 470         int stage_size;
 471         idetape_stage_t *merge_stage;
 472         int merge_stage_size;
 473         struct idetape_bh *bh;
 474         char *b_data;
 475         int b_count;
 476
 477         /*
 478          *      Pipeline parameters.
 479          *
 480          *      To accomplish non-pipelined mode, we simply set the following
 481          *      variables to zero (or NULL, where appropriate).
 482          */
 483         /* Number of currently used stages */
 484         int nr_stages;
 485         /* Number of pending stages */
 486         int nr_pending_stages;
 487         /* We will not allocate more than this number of stages */
 488         int max_stages, min_pipeline, max_pipeline;
 489         /* The first stage which will be removed from the pipeline */
 490         idetape_stage_t *first_stage;
 491         /* The currently active stage */
 492         idetape_stage_t *active_stage;
 493         /* Will be serviced after the currently active request */
 494         idetape_stage_t *next_stage;
 495         /* New requests will be added to the pipeline here */
 496         idetape_stage_t *last_stage;
 497         /* Optional free stage which we can use */
 498         idetape_stage_t *cache_stage;
 499         int pages_per_stage;
 500         /* Wasted space in each stage */
 501         int excess_bh_size;
 502
 503         /* Status/Action flags: long for set_bit */
 504         unsigned long flags;
 505         /* protects the ide-tape queue */
 506         spinlock_t spinlock;
 507
 508         /*
 509          * Measures average tape speed
 510          */
 511         unsigned long avg_time;
 512         int avg_size;
 513         int avg_speed;
 514
 515         /* last sense information */
 516         idetape_request_sense_result_t sense;
 517
 518         char vendor_id[10];
 519         char product_id[18];
 520         char firmware_revision[6];
 521         int firmware_revision_num;
 522
 523         /* the door is currently locked */
 524         int door_locked;
 525         /* the tape hardware is write protected */
 526         char drv_write_prot;
 527         /* the tape is write protected (hardware or opened as read-only) */
 528         char write_prot;
 529
 530         /*
 531          * Limit the number of times a request can
 532          * be postponed, to avoid an infinite postpone
 533          * deadlock.
 534          */
 535         /* request postpone count limit */
 536         int postpone_cnt;
 537
 538         /*
 539          * Measures number of frames:
 540          *
 541          * 1. written/read to/from the driver pipeline (pipeline_head).
 542          * 2. written/read to/from the tape buffers (idetape_bh).
 543          * 3. written/read by the tape to/from the media (tape_head).
 544          */
 545         int pipeline_head;
 546         int buffer_head;
 547         int tape_head;
 548         int last_tape_head;
 549
 550         /*
 551          * Speed control at the tape buffers input/output
 552          */
 553         unsigned long insert_time;
 554         int insert_size;
 555         int insert_speed;
 556         int max_insert_speed;
 557         int measure_insert_time;
 558
 559         /*
 560          * Measure tape still time, in milliseconds
 561          */
 562         unsigned long tape_still_time_begin;
 563         int tape_still_time;
 564
 565         /*
 566          * Speed regulation negative feedback loop
 567          */
 568         int speed_control;
 569         int pipeline_head_speed;
 570         int controlled_pipeline_head_speed;
 571         int uncontrolled_pipeline_head_speed;
 572         int controlled_last_pipeline_head;
 573         int uncontrolled_last_pipeline_head;
 574         unsigned long uncontrolled_pipeline_head_time;
 575         unsigned long controlled_pipeline_head_time;
 576         int controlled_previous_pipeline_head;
 577         int uncontrolled_previous_pipeline_head;
 578         unsigned long controlled_previous_head_time;
 579         unsigned long uncontrolled_previous_head_time;
 580         int restart_speed_control_req;
 581
 582         /*
 583          * Debug_level determines amount of debugging output;
 584          * can be changed using /proc/ide/hdx/settings
 585          * 0 : almost no debugging output
 586          * 1 : 0+output errors only
 587          * 2 : 1+output all sensekey/asc
 588          * 3 : 2+follow all chrdev related procedures
 589          * 4 : 3+follow all procedures
 590          * 5 : 4+include pc_stack rq_stack info
 591          * 6 : 5+USE_COUNT updates
 592          */
 593          int debug_level;
 594 } idetape_tape_t;
 595
 596 static DEFINE_MUTEX(idetape_ref_mutex);
 597
 598 static struct class *idetape_sysfs_class;
 599
 600 #define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref)
 601
 602 #define ide_tape_g(disk) \
 603         container_of((disk)->private_data, struct ide_tape_obj, driver)
 604
 605 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
 606 {
 607         struct ide_tape_obj *tape = NULL;
 608
 609         mutex_lock(&idetape_ref_mutex);
 610         tape = ide_tape_g(disk);
 611         if (tape)
 612                 kref_get(&tape->kref);
 613         mutex_unlock(&idetape_ref_mutex);
 614         return tape;
 615 }
 616
 617 static void ide_tape_release(struct kref *);
 618
 619 static void ide_tape_put(struct ide_tape_obj *tape)
 620 {
 621         mutex_lock(&idetape_ref_mutex);
 622         kref_put(&tape->kref, ide_tape_release);
 623         mutex_unlock(&idetape_ref_mutex);
 624 }
 625
 626 /*
 627  *      Tape door status
 628  */
 629 #define DOOR_UNLOCKED                   0
 630 #define DOOR_LOCKED                     1
 631 #define DOOR_EXPLICITLY_LOCKED          2
 632
 633 /*
 634  *      Tape flag bits values.
 635  */
 636 #define IDETAPE_IGNORE_DSC              0
 637 #define IDETAPE_ADDRESS_VALID           1       /* 0 When the tape position is unknown */
 638 #define IDETAPE_BUSY                    2       /* Device already opened */
 639 #define IDETAPE_PIPELINE_ERROR          3       /* Error detected in a pipeline stage */
 640 #define IDETAPE_DETECT_BS               4       /* Attempt to auto-detect the current user block size */
 641 #define IDETAPE_FILEMARK                5       /* Currently on a filemark */
 642 #define IDETAPE_DRQ_INTERRUPT           6       /* DRQ interrupt device */
 643 #define IDETAPE_READ_ERROR              7
 644 #define IDETAPE_PIPELINE_ACTIVE         8       /* pipeline active */
 645 /* 0 = no tape is loaded, so we don't rewind after ejecting */
 646 #define IDETAPE_MEDIUM_PRESENT          9
 647
 648 /*
 649  *      Supported ATAPI tape drives packet commands
 650  */
 651 #define IDETAPE_TEST_UNIT_READY_CMD     0x00
 652 #define IDETAPE_REWIND_CMD              0x01
 653 #define IDETAPE_REQUEST_SENSE_CMD       0x03
 654 #define IDETAPE_READ_CMD                0x08
 655 #define IDETAPE_WRITE_CMD               0x0a
 656 #define IDETAPE_WRITE_FILEMARK_CMD      0x10
 657 #define IDETAPE_SPACE_CMD               0x11
 658 #define IDETAPE_INQUIRY_CMD             0x12
 659 #define IDETAPE_ERASE_CMD               0x19
 660 #define IDETAPE_MODE_SENSE_CMD          0x1a
 661 #define IDETAPE_MODE_SELECT_CMD         0x15
 662 #define IDETAPE_LOAD_UNLOAD_CMD         0x1b
 663 #define IDETAPE_PREVENT_CMD             0x1e
 664 #define IDETAPE_LOCATE_CMD              0x2b
 665 #define IDETAPE_READ_POSITION_CMD       0x34
 666 #define IDETAPE_READ_BUFFER_CMD         0x3c
 667 #define IDETAPE_SET_SPEED_CMD           0xbb
 668
 669 /*
 670  *      Some defines for the READ BUFFER command
 671  */
 672 #define IDETAPE_RETRIEVE_FAULTY_BLOCK   6
 673
 674 /*
 675  *      Some defines for the SPACE command
 676  */
 677 #define IDETAPE_SPACE_OVER_FILEMARK     1
 678 #define IDETAPE_SPACE_TO_EOD            3
 679
 680 /*
 681  *      Some defines for the LOAD UNLOAD command
 682  */
 683 #define IDETAPE_LU_LOAD_MASK            1
 684 #define IDETAPE_LU_RETENSION_MASK       2
 685 #define IDETAPE_LU_EOT_MASK             4
 686
 687 /*
 688  *      Special requests for our block device strategy routine.
 689  *
 690  *      In order to service a character device command, we add special
 691  *      requests to the tail of our block device request queue and wait
 692  *      for their completion.
 693  */
 694
 695 enum {
 696         REQ_IDETAPE_PC1         = (1 << 0), /* packet command (first stage) */
 697         REQ_IDETAPE_PC2         = (1 << 1), /* packet command (second stage) */
 698         REQ_IDETAPE_READ        = (1 << 2),
 699         REQ_IDETAPE_WRITE       = (1 << 3),
 700         REQ_IDETAPE_READ_BUFFER = (1 << 4),
 701 };
 702
 703 /*
 704  *      Error codes which are returned in rq->errors to the higher part
 705  *      of the driver.
 706  */
 707 #define IDETAPE_ERROR_GENERAL           101
 708 #define IDETAPE_ERROR_FILEMARK          102
 709 #define IDETAPE_ERROR_EOD               103
 710
 711 /*
 712  *      The following is used to format the general configuration word of
 713  *      the ATAPI IDENTIFY DEVICE command.
 714  */
 715 struct idetape_id_gcw {
 716         unsigned packet_size            :2;     /* Packet Size */
 717         unsigned reserved234            :3;     /* Reserved */
 718         unsigned drq_type               :2;     /* Command packet DRQ type */
 719         unsigned removable              :1;     /* Removable media */
 720         unsigned device_type            :5;     /* Device type */
 721         unsigned reserved13             :1;     /* Reserved */
 722         unsigned protocol               :2;     /* Protocol type */
 723 };
 724
 725 /*
 726  *      INQUIRY packet command - Data Format (From Table 6-8 of QIC-157C)
 727  */
 728 typedef struct {
 729         unsigned        device_type     :5;     /* Peripheral Device Type */
 730         unsigned        reserved0_765   :3;     /* Peripheral Qualifier - Reserved */
 731         unsigned        reserved1_6t0   :7;     /* Reserved */
 732         unsigned        rmb             :1;     /* Removable Medium Bit */
 733         unsigned        ansi_version    :3;     /* ANSI Version */
 734         unsigned        ecma_version    :3;     /* ECMA Version */
 735         unsigned        iso_version     :2;     /* ISO Version */
 736         unsigned        response_format :4;     /* Response Data Format */
 737         unsigned        reserved3_45    :2;     /* Reserved */
 738         unsigned        reserved3_6     :1;     /* TrmIOP - Reserved */
 739         unsigned        reserved3_7     :1;     /* AENC - Reserved */
 740         __u8            additional_length;      /* Additional Length (total_length-4) */
 741         __u8            rsv5, rsv6, rsv7;       /* Reserved */
 742         __u8            vendor_id[8];           /* Vendor Identification */
 743         __u8            product_id[16];         /* Product Identification */
 744         __u8            revision_level[4];      /* Revision Level */
 745         __u8            vendor_specific[20];    /* Vendor Specific - Optional */
 746         __u8            reserved56t95[40];      /* Reserved - Optional */
 747                                                 /* Additional information may be returned */
 748 } idetape_inquiry_result_t;
 749
 750 /*
 751  *      READ POSITION packet command - Data Format (From Table 6-57)
 752  */
 753 typedef struct {
 754         unsigned        reserved0_10    :2;     /* Reserved */
 755         unsigned        bpu             :1;     /* Block Position Unknown */
 756         unsigned        reserved0_543   :3;     /* Reserved */
 757         unsigned        eop             :1;     /* End Of Partition */
 758         unsigned        bop             :1;     /* Beginning Of Partition */
 759         u8              partition;              /* Partition Number */
 760         u8              reserved2, reserved3;   /* Reserved */
 761         u32             first_block;            /* First Block Location */
 762         u32             last_block;             /* Last Block Location (Optional) */
 763         u8              reserved12;             /* Reserved */
 764         u8              blocks_in_buffer[3];    /* Blocks In Buffer - (Optional) */
 765         u32             bytes_in_buffer;        /* Bytes In Buffer (Optional) */
 766 } idetape_read_position_result_t;
 767
 768 /*
 769  *      Follows structures which are related to the SELECT SENSE / MODE SENSE
 770  *      packet commands. Those packet commands are still not supported
 771  *      by ide-tape.
 772  */
 773 #define IDETAPE_BLOCK_DESCRIPTOR        0
 774 #define IDETAPE_CAPABILITIES_PAGE       0x2a
 775 #define IDETAPE_PARAMTR_PAGE            0x2b   /* Onstream DI-x0 only */
 776 #define IDETAPE_BLOCK_SIZE_PAGE         0x30
 777 #define IDETAPE_BUFFER_FILLING_PAGE     0x33
 778
 779 /*
 780  *      Mode Parameter Header for the MODE SENSE packet command
 781  */
 782 typedef struct {
 783         __u8    mode_data_length;       /* Length of the following data transfer */
 784         __u8    medium_type;            /* Medium Type */
 785         __u8    dsp;                    /* Device Specific Parameter */
 786         __u8    bdl;                    /* Block Descriptor Length */
 787 #if 0
 788         /* data transfer page */
 789         __u8    page_code       :6;
 790         __u8    reserved0_6     :1;
 791         __u8    ps              :1;     /* parameters saveable */
 792         __u8    page_length;            /* page Length == 0x02 */
 793         __u8    reserved2;
 794         __u8    read32k         :1;     /* 32k blk size (data only) */
 795         __u8    read32k5        :1;     /* 32.5k blk size (data&AUX) */
 796         __u8    reserved3_23    :2;
 797         __u8    write32k        :1;     /* 32k blk size (data only) */
 798         __u8    write32k5       :1;     /* 32.5k blk size (data&AUX) */
 799         __u8    reserved3_6     :1;
 800         __u8    streaming       :1;     /* streaming mode enable */
 801 #endif
 802 } idetape_mode_parameter_header_t;
 803
 804 /*
 805  *      Mode Parameter Block Descriptor the MODE SENSE packet command
 806  *
 807  *      Support for block descriptors is optional.
 808  */
 809 typedef struct {
 810         __u8            density_code;           /* Medium density code */
 811         __u8            blocks[3];              /* Number of blocks */
 812         __u8            reserved4;              /* Reserved */
 813         __u8            length[3];              /* Block Length */
 814 } idetape_parameter_block_descriptor_t;
 815
 816 /*
 817  *      The Data Compression Page, as returned by the MODE SENSE packet command.
 818  */
 819 typedef struct {
 820         unsigned        page_code       :6;     /* Page Code - Should be 0xf */
 821         unsigned        reserved0       :1;     /* Reserved */
 822         unsigned        ps              :1;
 823         __u8            page_length;            /* Page Length - Should be 14 */
 824         unsigned        reserved2       :6;     /* Reserved */
 825         unsigned        dcc             :1;     /* Data Compression Capable */
 826         unsigned        dce             :1;     /* Data Compression Enable */
 827         unsigned        reserved3       :5;     /* Reserved */
 828         unsigned        red             :2;     /* Report Exception on Decompression */
 829         unsigned        dde             :1;     /* Data Decompression Enable */
 830         __u32           ca;                     /* Compression Algorithm */
 831         __u32           da;                     /* Decompression Algorithm */
 832         __u8            reserved[4];            /* Reserved */
 833 } idetape_data_compression_page_t;
 834
 835 /*
 836  *      The Medium Partition Page, as returned by the MODE SENSE packet command.
 837  */
 838 typedef struct {
 839         unsigned        page_code       :6;     /* Page Code - Should be 0x11 */
 840         unsigned        reserved1_6     :1;     /* Reserved */
 841         unsigned        ps              :1;
 842         __u8            page_length;            /* Page Length - Should be 6 */
 843         __u8            map;                    /* Maximum Additional Partitions - Should be 0 */
 844         __u8            apd;                    /* Additional Partitions Defined - Should be 0 */
 845         unsigned        reserved4_012   :3;     /* Reserved */
 846         unsigned        psum            :2;     /* Should be 0 */
 847         unsigned        idp             :1;     /* Should be 0 */
 848         unsigned        sdp             :1;     /* Should be 0 */
 849         unsigned        fdp             :1;     /* Fixed Data Partitions */
 850         __u8            mfr;                    /* Medium Format Recognition */
 851         __u8            reserved[2];            /* Reserved */
 852 } idetape_medium_partition_page_t;
 853
 854 /*
 855  *      Run time configurable parameters.
 856  */
 857 typedef struct {
 858         int     dsc_rw_frequency;
 859         int     dsc_media_access_frequency;
 860         int     nr_stages;
 861 } idetape_config_t;
 862
 863 /*
 864  *      The variables below are used for the character device interface.
 865  *      Additional state variables are defined in our ide_drive_t structure.
 866  */
 867 static struct ide_tape_obj * idetape_devs[MAX_HWIFS * MAX_DRIVES];
 868
 869 #define ide_tape_f(file) ((file)->private_data)
 870
 871 static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
 872 {
 873         struct ide_tape_obj *tape = NULL;
 874
 875         mutex_lock(&idetape_ref_mutex);
 876         tape = idetape_devs[i];
 877         if (tape)
 878                 kref_get(&tape->kref);
 879         mutex_unlock(&idetape_ref_mutex);
 880         return tape;
 881 }
 882
 883 /*
 884  *      Function declarations
 885  *
 886  */
 887 static int idetape_chrdev_release (struct inode *inode, struct file *filp);
 888 static void idetape_write_release (ide_drive_t *drive, unsigned int minor);
 889
 890 /*
 891  * Too bad. The drive wants to send us data which we are not ready to accept.
 892  * Just throw it away.
 893  */
 894 static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount)
 895 {
 896         while (bcount--)
 897                 (void) HWIF(drive)->INB(IDE_DATA_REG);
 898 }
 899
 900 static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
 901 {
 902         struct idetape_bh *bh = pc->bh;
 903         int count;
 904
 905         while (bcount) {
 906 #if IDETAPE_DEBUG_BUGS
 907                 if (bh == NULL) {
 908                         printk(KERN_ERR "ide-tape: bh == NULL in "
 909                                 "idetape_input_buffers\n");
 910                         idetape_discard_data(drive, bcount);
 911                         return;
 912                 }
 913 #endif /* IDETAPE_DEBUG_BUGS */
 914                 count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount);
 915                 HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count);
 916                 bcount -= count;
 917                 atomic_add(count, &bh->b_count);
 918                 if (atomic_read(&bh->b_count) == bh->b_size) {
 919                         bh = bh->b_reqnext;
 920                         if (bh)
 921                                 atomic_set(&bh->b_count, 0);
 922                 }
 923         }
 924         pc->bh = bh;
 925 }
 926
 927 static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
 928 {
 929         struct idetape_bh *bh = pc->bh;
 930         int count;
 931
 932         while (bcount) {
 933 #if IDETAPE_DEBUG_BUGS
 934                 if (bh == NULL) {
 935                         printk(KERN_ERR "ide-tape: bh == NULL in "
 936                                 "idetape_output_buffers\n");
 937                         return;
 938                 }
 939 #endif /* IDETAPE_DEBUG_BUGS */
 940                 count = min((unsigned int)pc->b_count, (unsigned int)bcount);
 941                 HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count);
 942                 bcount -= count;
 943                 pc->b_data += count;
 944                 pc->b_count -= count;
 945                 if (!pc->b_count) {
 946                         pc->bh = bh = bh->b_reqnext;
 947                         if (bh) {
 948                                 pc->b_data = bh->b_data;
 949                                 pc->b_count = atomic_read(&bh->b_count);
 950                         }
 951                 }
 952         }
 953 }
 954
 955 static void idetape_update_buffers (idetape_pc_t *pc)
 956 {
 957         struct idetape_bh *bh = pc->bh;
 958         int count;
 959         unsigned int bcount = pc->actually_transferred;
 960
 961         if (test_bit(PC_WRITING, &pc->flags))
 962                 return;
 963         while (bcount) {
 964 #if IDETAPE_DEBUG_BUGS
 965                 if (bh == NULL) {
 966                         printk(KERN_ERR "ide-tape: bh == NULL in "
 967                                 "idetape_update_buffers\n");
 968                         return;
 969                 }
 970 #endif /* IDETAPE_DEBUG_BUGS */
 971                 count = min((unsigned int)bh->b_size, (unsigned int)bcount);
 972                 atomic_set(&bh->b_count, count);
 973                 if (atomic_read(&bh->b_count) == bh->b_size)
 974                         bh = bh->b_reqnext;
 975                 bcount -= count;
 976         }
 977         pc->bh = bh;
 978 }
 979
 980 /*
 981  *      idetape_next_pc_storage returns a pointer to a place in which we can
 982  *      safely store a packet command, even though we intend to leave the
 983  *      driver. A storage space for a maximum of IDETAPE_PC_STACK packet
 984  *      commands is allocated at initialization time.
 985  */
 986 static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive)
 987 {
 988         idetape_tape_t *tape = drive->driver_data;
 989
 990 #if IDETAPE_DEBUG_LOG
 991         if (tape->debug_level >= 5)
 992                 printk(KERN_INFO "ide-tape: pc_stack_index=%d\n",
 993                         tape->pc_stack_index);
 994 #endif /* IDETAPE_DEBUG_LOG */
 995         if (tape->pc_stack_index == IDETAPE_PC_STACK)
 996                 tape->pc_stack_index=0;
 997         return (&tape->pc_stack[tape->pc_stack_index++]);
 998 }
 999
1000 /*
1001  *      idetape_next_rq_storage is used along with idetape_next_pc_storage.
1002  *      Since we queue packet commands in the request queue, we need to
1003  *      allocate a request, along with the allocation of a packet command.
1004  */
1005
1006 /**************************************************************
1007  *                                                            *
1008  *  This should get fixed to use kmalloc(.., GFP_ATOMIC)      *
1009  *  followed later on by kfree().   -ml                       *
1010  *                                                            *
1011  **************************************************************/
1012
1013 static struct request *idetape_next_rq_storage (ide_drive_t *drive)
1014 {
1015         idetape_tape_t *tape = drive->driver_data;
1016
1017 #if IDETAPE_DEBUG_LOG
1018         if (tape->debug_level >= 5)
1019                 printk(KERN_INFO "ide-tape: rq_stack_index=%d\n",
1020                         tape->rq_stack_index);
1021 #endif /* IDETAPE_DEBUG_LOG */
1022         if (tape->rq_stack_index == IDETAPE_PC_STACK)
1023                 tape->rq_stack_index=0;
1024         return (&tape->rq_stack[tape->rq_stack_index++]);
1025 }
1026
1027 /*
1028  *      idetape_init_pc initializes a packet command.
1029  */
1030 static void idetape_init_pc (idetape_pc_t *pc)
1031 {
1032         memset(pc->c, 0, 12);
1033         pc->retries = 0;
1034         pc->flags = 0;
1035         pc->request_transfer = 0;
1036         pc->buffer = pc->pc_buffer;
1037         pc->buffer_size = IDETAPE_PC_BUFFER_SIZE;
1038         pc->bh = NULL;
1039         pc->b_data = NULL;
1040 }
1041
1042 /*
1043  *      idetape_analyze_error is called on each failed packet command retry
1044  *      to analyze the request sense. We currently do not utilize this
1045  *      information.
1046  */
1047 static void idetape_analyze_error (ide_drive_t *drive, idetape_request_sense_result_t *result)
1048 {
1049         idetape_tape_t *tape = drive->driver_data;
1050         idetape_pc_t *pc = tape->failed_pc;
1051
1052         tape->sense     = *result;
1053         tape->sense_key = result->sense_key;
1054         tape->asc       = result->asc;
1055         tape->ascq      = result->ascq;
1056 #if IDETAPE_DEBUG_LOG
1057         /*
1058          *      Without debugging, we only log an error if we decided to
1059          *      give up retrying.
1060          */
1061         if (tape->debug_level >= 1)
1062                 printk(KERN_INFO "ide-tape: pc = %x, sense key = %x, "
1063                         "asc = %x, ascq = %x\n",
1064                         pc->c[0], result->sense_key,
1065                         result->asc, result->ascq);
1066 #endif /* IDETAPE_DEBUG_LOG */
1067
1068         /*
1069          *      Correct pc->actually_transferred by asking the tape.
1070          */
1071         if (test_bit(PC_DMA_ERROR, &pc->flags)) {
1072                 pc->actually_transferred = pc->request_transfer - tape->tape_block_size * ntohl(get_unaligned(&result->information));
1073                 idetape_update_buffers(pc);
1074         }
1075
1076         /*
1077          * If error was the result of a zero-length read or write command,
1078          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
1079          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
1080          */
1081         if ((pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD)
1082             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { /* length==0 */
1083                 if (result->sense_key == 5) {
1084                         /* don't report an error, everything's ok */
1085                         pc->error = 0;
1086                         /* don't retry read/write */
1087                         set_bit(PC_ABORT, &pc->flags);
1088                 }
1089         }
1090         if (pc->c[0] == IDETAPE_READ_CMD && result->filemark) {
1091                 pc->error = IDETAPE_ERROR_FILEMARK;
1092                 set_bit(PC_ABORT, &pc->flags);
1093         }
1094         if (pc->c[0] == IDETAPE_WRITE_CMD) {
1095                 if (result->eom ||
1096                     (result->sense_key == 0xd && result->asc == 0x0 &&
1097                      result->ascq == 0x2)) {
1098                         pc->error = IDETAPE_ERROR_EOD;
1099                         set_bit(PC_ABORT, &pc->flags);
1100                 }
1101         }
1102         if (pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD) {
1103                 if (result->sense_key == 8) {
1104                         pc->error = IDETAPE_ERROR_EOD;
1105                         set_bit(PC_ABORT, &pc->flags);
1106                 }
1107                 if (!test_bit(PC_ABORT, &pc->flags) &&
1108                     pc->actually_transferred)
1109                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
1110         }
1111 }
1112
1113 /*
1114  * idetape_active_next_stage will declare the next stage as "active".
1115  */
1116 static void idetape_active_next_stage (ide_drive_t *drive)
1117 {
1118         idetape_tape_t *tape = drive->driver_data;
1119         idetape_stage_t *stage = tape->next_stage;
1120         struct request *rq = &stage->rq;
1121
1122 #if IDETAPE_DEBUG_LOG
1123         if (tape->debug_level >= 4)
1124                 printk(KERN_INFO "ide-tape: Reached idetape_active_next_stage\n");
1125 #endif /* IDETAPE_DEBUG_LOG */
1126 #if IDETAPE_DEBUG_BUGS
1127         if (stage == NULL) {
1128                 printk(KERN_ERR "ide-tape: bug: Trying to activate a non existing stage\n");
1129                 return;
1130         }
1131 #endif /* IDETAPE_DEBUG_BUGS */
1132
1133         rq->rq_disk = tape->disk;
1134         rq->buffer = NULL;
1135         rq->special = (void *)stage->bh;
1136         tape->active_data_request = rq;
1137         tape->active_stage = stage;
1138         tape->next_stage = stage->next;
1139 }
1140
1141 /*
1142  *      idetape_increase_max_pipeline_stages is a part of the feedback
1143  *      loop which tries to find the optimum number of stages. In the
1144  *      feedback loop, we are starting from a minimum maximum number of
1145  *      stages, and if we sense that the pipeline is empty, we try to
1146  *      increase it, until we reach the user compile time memory limit.
1147  */
1148 static void idetape_increase_max_pipeline_stages (ide_drive_t *drive)
1149 {
1150         idetape_tape_t *tape = drive->driver_data;
1151         int increase = (tape->max_pipeline - tape->min_pipeline) / 10;
1152
1153 #if IDETAPE_DEBUG_LOG
1154         if (tape->debug_level >= 4)
1155                 printk (KERN_INFO "ide-tape: Reached idetape_increase_max_pipeline_stages\n");
1156 #endif /* IDETAPE_DEBUG_LOG */
1157
1158         tape->max_stages += max(increase, 1);
1159         tape->max_stages = max(tape->max_stages, tape->min_pipeline);
1160         tape->max_stages = min(tape->max_stages, tape->max_pipeline);
1161 }
1162
1163 /*
1164  *      idetape_kfree_stage calls kfree to completely free a stage, along with
1165  *      its related buffers.
1166  */
1167 static void __idetape_kfree_stage (idetape_stage_t *stage)
1168 {
1169         struct idetape_bh *prev_bh, *bh = stage->bh;
1170         int size;
1171
1172         while (bh != NULL) {
1173                 if (bh->b_data != NULL) {
1174                         size = (int) bh->b_size;
1175                         while (size > 0) {
1176                                 free_page((unsigned long) bh->b_data);
1177                                 size -= PAGE_SIZE;
1178                                 bh->b_data += PAGE_SIZE;
1179                         }
1180                 }
1181                 prev_bh = bh;
1182                 bh = bh->b_reqnext;
1183                 kfree(prev_bh);
1184         }
1185         kfree(stage);
1186 }
1187
1188 static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage)
1189 {
1190         __idetape_kfree_stage(stage);
1191 }
1192
1193 /*
1194  *      idetape_remove_stage_head removes tape->first_stage from the pipeline.
1195  *      The caller should avoid race conditions.
1196  */
1197 static void idetape_remove_stage_head (ide_drive_t *drive)
1198 {
1199         idetape_tape_t *tape = drive->driver_data;
1200         idetape_stage_t *stage;
1201
1202 #if IDETAPE_DEBUG_LOG
1203         if (tape->debug_level >= 4)
1204                 printk(KERN_INFO "ide-tape: Reached idetape_remove_stage_head\n");
1205 #endif /* IDETAPE_DEBUG_LOG */
1206 #if IDETAPE_DEBUG_BUGS
1207         if (tape->first_stage == NULL) {
1208                 printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n");
1209                 return;
1210         }
1211         if (tape->active_stage == tape->first_stage) {
1212                 printk(KERN_ERR "ide-tape: bug: Trying to free our active pipeline stage\n");
1213                 return;
1214         }
1215 #endif /* IDETAPE_DEBUG_BUGS */
1216         stage = tape->first_stage;
1217         tape->first_stage = stage->next;
1218         idetape_kfree_stage(tape, stage);
1219         tape->nr_stages--;
1220         if (tape->first_stage == NULL) {
1221                 tape->last_stage = NULL;
1222 #if IDETAPE_DEBUG_BUGS
1223                 if (tape->next_stage != NULL)
1224                         printk(KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n");
1225                 if (tape->nr_stages)
1226                         printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n");
1227 #endif /* IDETAPE_DEBUG_BUGS */
1228         }
1229 }
1230
1231 /*
1232  * This will free all the pipeline stages starting from new_last_stage->next
1233  * to the end of the list, and point tape->last_stage to new_last_stage.
1234  */
1235 static void idetape_abort_pipeline(ide_drive_t *drive,
1236                                    idetape_stage_t *new_last_stage)
1237 {
1238         idetape_tape_t *tape = drive->driver_data;
1239         idetape_stage_t *stage = new_last_stage->next;
1240         idetape_stage_t *nstage;
1241
1242 #if IDETAPE_DEBUG_LOG
1243         if (tape->debug_level >= 4)
1244                 printk(KERN_INFO "ide-tape: %s: idetape_abort_pipeline called\n", tape->name);
1245 #endif
1246         while (stage) {
1247                 nstage = stage->next;
1248                 idetape_kfree_stage(tape, stage);
1249                 --tape->nr_stages;
1250                 --tape->nr_pending_stages;
1251                 stage = nstage;
1252         }
1253         if (new_last_stage)
1254                 new_last_stage->next = NULL;
1255         tape->last_stage = new_last_stage;
1256         tape->next_stage = NULL;
1257 }
1258
1259 /*
1260  *      idetape_end_request is used to finish servicing a request, and to
1261  *      insert a pending pipeline request into the main device queue.
1262  */
1263 static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
1264 {
1265         struct request *rq = HWGROUP(drive)->rq;
1266         idetape_tape_t *tape = drive->driver_data;
1267         unsigned long flags;
1268         int error;
1269         int remove_stage = 0;
1270         idetape_stage_t *active_stage;
1271
1272 #if IDETAPE_DEBUG_LOG
1273         if (tape->debug_level >= 4)
1274         printk(KERN_INFO "ide-tape: Reached idetape_end_request\n");
1275 #endif /* IDETAPE_DEBUG_LOG */
1276
1277         switch (uptodate) {
1278                 case 0: error = IDETAPE_ERROR_GENERAL; break;
1279                 case 1: error = 0; break;
1280                 default: error = uptodate;
1281         }
1282         rq->errors = error;
1283         if (error)
1284                 tape->failed_pc = NULL;
1285
1286         if (!blk_special_request(rq)) {
1287                 ide_end_request(drive, uptodate, nr_sects);
1288                 return 0;
1289         }
1290
1291         spin_lock_irqsave(&tape->spinlock, flags);
1292
1293         /* The request was a pipelined data transfer request */
1294         if (tape->active_data_request == rq) {
1295                 active_stage = tape->active_stage;
1296                 tape->active_stage = NULL;
1297                 tape->active_data_request = NULL;
1298                 tape->nr_pending_stages--;
1299                 if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
1300                         remove_stage = 1;
1301                         if (error) {
1302                                 set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
1303                                 if (error == IDETAPE_ERROR_EOD)
1304                                         idetape_abort_pipeline(drive, active_stage);
1305                         }
1306                 } else if (rq->cmd[0] & REQ_IDETAPE_READ) {
1307                         if (error == IDETAPE_ERROR_EOD) {
1308                                 set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
1309                                 idetape_abort_pipeline(drive, active_stage);
1310                         }
1311                 }
1312                 if (tape->next_stage != NULL) {
1313                         idetape_active_next_stage(drive);
1314
1315                         /*
1316                          * Insert the next request into the request queue.
1317                          */
1318                         (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
1319                 } else if (!error) {
1320                                 idetape_increase_max_pipeline_stages(drive);
1321                 }
1322         }
1323         ide_end_drive_cmd(drive, 0, 0);
1324 //      blkdev_dequeue_request(rq);
1325 //      drive->rq = NULL;
1326 //      end_that_request_last(rq);
1327
1328         if (remove_stage)
1329                 idetape_remove_stage_head(drive);
1330         if (tape->active_data_request == NULL)
1331                 clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
1332         spin_unlock_irqrestore(&tape->spinlock, flags);
1333         return 0;
1334 }
1335
1336 static ide_startstop_t idetape_request_sense_callback (ide_drive_t *drive)
1337 {
1338         idetape_tape_t *tape = drive->driver_data;
1339
1340 #if IDETAPE_DEBUG_LOG
1341         if (tape->debug_level >= 4)
1342                 printk(KERN_INFO "ide-tape: Reached idetape_request_sense_callback\n");
1343 #endif /* IDETAPE_DEBUG_LOG */
1344         if (!tape->pc->error) {
1345                 idetape_analyze_error(drive, (idetape_request_sense_result_t *) tape->pc->buffer);
1346                 idetape_end_request(drive, 1, 0);
1347         } else {
1348                 printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - Aborting request!\n");
1349                 idetape_end_request(drive, 0, 0);
1350         }
1351         return ide_stopped;
1352 }
1353
1354 static void idetape_create_request_sense_cmd (idetape_pc_t *pc)
1355 {
1356         idetape_init_pc(pc);
1357         pc->c[0] = IDETAPE_REQUEST_SENSE_CMD;
1358         pc->c[4] = 20;
1359         pc->request_transfer = 20;
1360         pc->callback = &idetape_request_sense_callback;
1361 }
1362
1363 static void idetape_init_rq(struct request *rq, u8 cmd)
1364 {
1365         memset(rq, 0, sizeof(*rq));
1366         rq->cmd_type = REQ_TYPE_SPECIAL;
1367         rq->cmd[0] = cmd;
1368 }
1369
1370 /*
1371  *      idetape_queue_pc_head generates a new packet command request in front
1372  *      of the request queue, before the current request, so that it will be
1373  *      processed immediately, on the next pass through the driver.
1374  *
1375  *      idetape_queue_pc_head is called from the request handling part of
1376  *      the driver (the "bottom" part). Safe storage for the request should
1377  *      be allocated with idetape_next_pc_storage and idetape_next_rq_storage
1378  *      before calling idetape_queue_pc_head.
1379  *
1380  *      Memory for those requests is pre-allocated at initialization time, and
1381  *      is limited to IDETAPE_PC_STACK requests. We assume that we have enough
1382  *      space for the maximum possible number of inter-dependent packet commands.
1383  *
1384  *      The higher level of the driver - The ioctl handler and the character
1385  *      device handling functions should queue request to the lower level part
1386  *      and wait for their completion using idetape_queue_pc_tail or
1387  *      idetape_queue_rw_tail.
1388  */
1389 static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct request *rq)
1390 {
1391         struct ide_tape_obj *tape = drive->driver_data;
1392
1393         idetape_init_rq(rq, REQ_IDETAPE_PC1);
1394         rq->buffer = (char *) pc;
1395         rq->rq_disk = tape->disk;
1396         (void) ide_do_drive_cmd(drive, rq, ide_preempt);
1397 }
1398
1399 /*
1400  *      idetape_retry_pc is called when an error was detected during the
1401  *      last packet command. We queue a request sense packet command in
1402  *      the head of the request list.
1403  */
1404 static ide_startstop_t idetape_retry_pc (ide_drive_t *drive)
1405 {
1406         idetape_tape_t *tape = drive->driver_data;
1407         idetape_pc_t *pc;
1408         struct request *rq;
1409
1410         (void)drive->hwif->INB(IDE_ERROR_REG);
1411         pc = idetape_next_pc_storage(drive);
1412         rq = idetape_next_rq_storage(drive);
1413         idetape_create_request_sense_cmd(pc);
1414         set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
1415         idetape_queue_pc_head(drive, pc, rq);
1416         return ide_stopped;
1417 }
1418
1419 /*
1420  *      idetape_postpone_request postpones the current request so that
1421  *      ide.c will be able to service requests from another device on
1422  *      the same hwgroup while we are polling for DSC.
1423  */
1424 static void idetape_postpone_request (ide_drive_t *drive)
1425 {
1426         idetape_tape_t *tape = drive->driver_data;
1427
1428 #if IDETAPE_DEBUG_LOG
1429         if (tape->debug_level >= 4)
1430                 printk(KERN_INFO "ide-tape: idetape_postpone_request\n");
1431 #endif
1432         tape->postponed_rq = HWGROUP(drive)->rq;
1433         ide_stall_queue(drive, tape->dsc_polling_frequency);
1434 }
1435
1436 /*
1437  *      idetape_pc_intr is the usual interrupt handler which will be called
1438  *      during a packet command. We will transfer some of the data (as
1439  *      requested by the drive) and will re-point interrupt handler to us.
1440  *      When data transfer is finished, we will act according to the
1441  *      algorithm described before idetape_issue_packet_command.
1442  *
1443  */
1444 static ide_startstop_t idetape_pc_intr (ide_drive_t *drive)
1445 {
1446         ide_hwif_t *hwif = drive->hwif;
1447         idetape_tape_t *tape = drive->driver_data;
1448         idetape_pc_t *pc = tape->pc;
1449         unsigned int temp;
1450 #if SIMULATE_ERRORS
1451         static int error_sim_count = 0;
1452 #endif
1453         u16 bcount;
1454         u8 stat, ireason;
1455
1456 #if IDETAPE_DEBUG_LOG
1457         if (tape->debug_level >= 4)
1458                 printk(KERN_INFO "ide-tape: Reached idetape_pc_intr "
1459                                 "interrupt handler\n");
1460 #endif /* IDETAPE_DEBUG_LOG */
1461
1462         /* Clear the interrupt */
1463         stat = hwif->INB(IDE_STATUS_REG);
1464
1465         if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
1466                 if (hwif->ide_dma_end(drive) || (stat & ERR_STAT)) {
1467                         /*
1468                          * A DMA error is sometimes expected. For example,
1469                          * if the tape is crossing a filemark during a
1470                          * READ command, it will issue an irq and position
1471                          * itself before the filemark, so that only a partial
1472                          * data transfer will occur (which causes the DMA
1473                          * error). In that case, we will later ask the tape
1474                          * how much bytes of the original request were
1475                          * actually transferred (we can't receive that
1476                          * information from the DMA engine on most chipsets).
1477                          */
1478
1479                         /*
1480                          * On the contrary, a DMA error is never expected;
1481                          * it usually indicates a hardware error or abort.
1482                          * If the tape crosses a filemark during a READ
1483                          * command, it will issue an irq and position itself
1484                          * after the filemark (not before). Only a partial
1485                          * data transfer will occur, but no DMA error.
1486                          * (AS, 19 Apr 2001)
1487                          */
1488                         set_bit(PC_DMA_ERROR, &pc->flags);
1489                 } else {
1490                         pc->actually_transferred = pc->request_transfer;
1491                         idetape_update_buffers(pc);
1492                 }
1493 #if IDETAPE_DEBUG_LOG
1494                 if (tape->debug_level >= 4)
1495                         printk(KERN_INFO "ide-tape: DMA finished\n");
1496 #endif /* IDETAPE_DEBUG_LOG */
1497         }
1498
1499         /* No more interrupts */
1500         if ((stat & DRQ_STAT) == 0) {
1501 #if IDETAPE_DEBUG_LOG
1502                 if (tape->debug_level >= 2)
1503                         printk(KERN_INFO "ide-tape: Packet command completed, %d bytes transferred\n", pc->actually_transferred);
1504 #endif /* IDETAPE_DEBUG_LOG */
1505                 clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
1506
1507                 local_irq_enable();
1508
1509 #if SIMULATE_ERRORS
1510                 if ((pc->c[0] == IDETAPE_WRITE_CMD ||
1511                      pc->c[0] == IDETAPE_READ_CMD) &&
1512                     (++error_sim_count % 100) == 0) {
1513                         printk(KERN_INFO "ide-tape: %s: simulating error\n",
1514                                 tape->name);
1515                         stat |= ERR_STAT;
1516                 }
1517 #endif
1518                 if ((stat & ERR_STAT) && pc->c[0] == IDETAPE_REQUEST_SENSE_CMD)
1519                         stat &= ~ERR_STAT;
1520                 if ((stat & ERR_STAT) || test_bit(PC_DMA_ERROR, &pc->flags)) {
1521                         /* Error detected */
1522 #if IDETAPE_DEBUG_LOG
1523                         if (tape->debug_level >= 1)
1524                                 printk(KERN_INFO "ide-tape: %s: I/O error\n",
1525                                         tape->name);
1526 #endif /* IDETAPE_DEBUG_LOG */
1527                         if (pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
1528                                 printk(KERN_ERR "ide-tape: I/O error in request sense command\n");
1529                                 return ide_do_reset(drive);
1530                         }
1531 #if IDETAPE_DEBUG_LOG
1532                         if (tape->debug_level >= 1)
1533                                 printk(KERN_INFO "ide-tape: [cmd %x]: check condition\n", pc->c[0]);
1534 #endif
1535                         /* Retry operation */
1536                         return idetape_retry_pc(drive);
1537                 }
1538                 pc->error = 0;
1539                 if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
1540                     (stat & SEEK_STAT) == 0) {
1541                         /* Media access command */
1542                         tape->dsc_polling_start = jiffies;
1543                         tape->dsc_polling_frequency = IDETAPE_DSC_MA_FAST;
1544                         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
1545                         /* Allow ide.c to handle other requests */
1546                         idetape_postpone_request(drive);
1547                         return ide_stopped;
1548                 }
1549                 if (tape->failed_pc == pc)
1550                         tape->failed_pc = NULL;
1551                 /* Command finished - Call the callback function */
1552                 return pc->callback(drive);
1553         }
1554         if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
1555                 printk(KERN_ERR "ide-tape: The tape wants to issue more "
1556                                 "interrupts in DMA mode\n");
1557                 printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
1558                 ide_dma_off(drive);
1559                 return ide_do_reset(drive);
1560         }
1561         /* Get the number of bytes to transfer on this interrupt. */
1562         bcount = (hwif->INB(IDE_BCOUNTH_REG) << 8) |
1563                   hwif->INB(IDE_BCOUNTL_REG);
1564
1565         ireason = hwif->INB(IDE_IREASON_REG);
1566
1567         if (ireason & CD) {
1568                 printk(KERN_ERR "ide-tape: CoD != 0 in idetape_pc_intr\n");
1569                 return ide_do_reset(drive);
1570         }
1571         if (((ireason & IO) == IO) == test_bit(PC_WRITING, &pc->flags)) {
1572                 /* Hopefully, we will never get here */
1573                 printk(KERN_ERR "ide-tape: We wanted to %s, ",
1574                                 (ireason & IO) ? "Write" : "Read");
1575                 printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n",
1576                                 (ireason & IO) ? "Read" : "Write");
1577                 return ide_do_reset(drive);
1578         }
1579         if (!test_bit(PC_WRITING, &pc->flags)) {
1580                 /* Reading - Check that we have enough space */
1581                 temp = pc->actually_transferred + bcount;
1582                 if (temp > pc->request_transfer) {
1583                         if (temp > pc->buffer_size) {
1584                                 printk(KERN_ERR "ide-tape: The tape wants to send us more data than expected - discarding data\n");
1585                                 idetape_discard_data(drive, bcount);
1586                                 ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
1587                                 return ide_started;
1588                         }
1589 #if IDETAPE_DEBUG_LOG
1590                         if (tape->debug_level >= 2)
1591                                 printk(KERN_NOTICE "ide-tape: The tape wants to send us more data than expected - allowing transfer\n");
1592 #endif /* IDETAPE_DEBUG_LOG */
1593                 }
1594         }
1595         if (test_bit(PC_WRITING, &pc->flags)) {
1596                 if (pc->bh != NULL)
1597                         idetape_output_buffers(drive, pc, bcount);
1598                 else
1599                         /* Write the current buffer */
1600                         hwif->atapi_output_bytes(drive, pc->current_position,
1601                                                  bcount);
1602         } else {
1603                 if (pc->bh != NULL)
1604                         idetape_input_buffers(drive, pc, bcount);
1605                 else
1606                         /* Read the current buffer */
1607                         hwif->atapi_input_bytes(drive, pc->current_position,
1608                                                 bcount);
1609         }
1610         /* Update the current position */
1611         pc->actually_transferred += bcount;
1612         pc->current_position += bcount;
1613 #if IDETAPE_DEBUG_LOG
1614         if (tape->debug_level >= 2)
1615                 printk(KERN_INFO "ide-tape: [cmd %x] transferred %d bytes "
1616                                  "on that interrupt\n", pc->c[0], bcount);
1617 #endif
1618         /* And set the interrupt handler again */
1619         ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
1620         return ide_started;
1621 }
1622
1623 /*
1624  *      Packet Command Interface
1625  *
1626  *      The current Packet Command is available in tape->pc, and will not
1627  *      change until we finish handling it. Each packet command is associated
1628  *      with a callback function that will be called when the command is
1629  *      finished.
1630  *
1631  *      The handling will be done in three stages:
1632  *
1633  *      1.      idetape_issue_packet_command will send the packet command to the
1634  *              drive, and will set the interrupt handler to idetape_pc_intr.
1635  *
1636  *      2.      On each interrupt, idetape_pc_intr will be called. This step
1637  *              will be repeated until the device signals us that no more
1638  *              interrupts will be issued.
1639  *
1640  *      3.      ATAPI Tape media access commands have immediate status with a
1641  *              delayed process. In case of a successful initiation of a
1642  *              media access packet command, the DSC bit will be set when the
1643  *              actual execution of the command is finished.
1644  *              Since the tape drive will not issue an interrupt, we have to
1645  *              poll for this event. In this case, we define the request as
1646  *              "low priority request" by setting rq_status to
1647  *              IDETAPE_RQ_POSTPONED,   set a timer to poll for DSC and exit
1648  *              the driver.
1649  *
1650  *              ide.c will then give higher priority to requests which
1651  *              originate from the other device, until will change rq_status
1652  *              to RQ_ACTIVE.
1653  *
1654  *      4.      When the packet command is finished, it will be checked for errors.
1655  *
1656  *      5.      In case an error was found, we queue a request sense packet
1657  *              command in front of the request queue and retry the operation
1658  *              up to IDETAPE_MAX_PC_RETRIES times.
1659  *
1660  *      6.      In case no error was found, or we decided to give up and not
1661  *              to retry again, the callback function will be called and then
1662  *              we will handle the next request.
1663  *
1664  */
1665 static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
1666 {
1667         ide_hwif_t *hwif = drive->hwif;
1668         idetape_tape_t *tape = drive->driver_data;
1669         idetape_pc_t *pc = tape->pc;
1670         int retries = 100;
1671         ide_startstop_t startstop;
1672         u8 ireason;
1673
1674         if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
1675                 printk(KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n");
1676                 return startstop;
1677         }
1678         ireason = hwif->INB(IDE_IREASON_REG);
1679         while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) {
1680                 printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing "
1681                                 "a packet command, retrying\n");
1682                 udelay(100);
1683                 ireason = hwif->INB(IDE_IREASON_REG);
1684                 if (retries == 0) {
1685                         printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while "
1686                                         "issuing a packet command, ignoring\n");
1687                         ireason |= CD;
1688                         ireason &= ~IO;
1689                 }
1690         }
1691         if ((ireason & CD) == 0 || (ireason & IO)) {
1692                 printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing "
1693                                 "a packet command\n");
1694                 return ide_do_reset(drive);
1695         }
1696         /* Set the interrupt routine */
1697         ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
1698 #ifdef CONFIG_BLK_DEV_IDEDMA
1699         /* Begin DMA, if necessary */
1700         if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags))
1701                 hwif->dma_start(drive);
1702 #endif
1703         /* Send the actual packet */
1704         HWIF(drive)->atapi_output_bytes(drive, pc->c, 12);
1705         return ide_started;
1706 }
1707
1708 static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape_pc_t *pc)
1709 {
1710         ide_hwif_t *hwif = drive->hwif;
1711         idetape_tape_t *tape = drive->driver_data;
1712         int dma_ok = 0;
1713         u16 bcount;
1714
1715 #if IDETAPE_DEBUG_BUGS
1716         if (tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD &&
1717             pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
1718                 printk(KERN_ERR "ide-tape: possible ide-tape.c bug - "
1719                         "Two request sense in serial were issued\n");
1720         }
1721 #endif /* IDETAPE_DEBUG_BUGS */
1722
1723         if (tape->failed_pc == NULL && pc->c[0] != IDETAPE_REQUEST_SENSE_CMD)
1724                 tape->failed_pc = pc;
1725         /* Set the current packet command */
1726         tape->pc = pc;
1727
1728         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
1729             test_bit(PC_ABORT, &pc->flags)) {
1730                 /*
1731                  *      We will "abort" retrying a packet command in case
1732                  *      a legitimate error code was received (crossing a
1733                  *      filemark, or end of the media, for example).
1734                  */
1735                 if (!test_bit(PC_ABORT, &pc->flags)) {
1736                         if (!(pc->c[0] == IDETAPE_TEST_UNIT_READY_CMD &&
1737                               tape->sense_key == 2 && tape->asc == 4 &&
1738                              (tape->ascq == 1 || tape->ascq == 8))) {
1739                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
1740                                                 "pc = %2x, key = %2x, "
1741                                                 "asc = %2x, ascq = %2x\n",
1742                                                 tape->name, pc->c[0],
1743                                                 tape->sense_key, tape->asc,
1744                                                 tape->ascq);
1745                         }
1746                         /* Giving up */
1747                         pc->error = IDETAPE_ERROR_GENERAL;
1748                 }
1749                 tape->failed_pc = NULL;
1750                 return pc->callback(drive);
1751         }
1752 #if IDETAPE_DEBUG_LOG
1753         if (tape->debug_level >= 2)
1754                 printk(KERN_INFO "ide-tape: Retry number - %d, cmd = %02X\n", pc->retries, pc->c[0]);
1755 #endif /* IDETAPE_DEBUG_LOG */
1756
1757         pc->retries++;
1758         /* We haven't transferred any data yet */
1759         pc->actually_transferred = 0;
1760         pc->current_position = pc->buffer;
1761         /* Request to transfer the entire buffer at once */
1762         bcount = pc->request_transfer;
1763
1764         if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) {
1765                 printk(KERN_WARNING "ide-tape: DMA disabled, "
1766                                 "reverting to PIO\n");
1767                 ide_dma_off(drive);
1768         }
1769         if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma)
1770                 dma_ok = !hwif->dma_setup(drive);
1771
1772         ide_pktcmd_tf_load(drive, IDE_TFLAG_NO_SELECT_MASK |
1773                            IDE_TFLAG_OUT_DEVICE, bcount, dma_ok);
1774
1775         if (dma_ok)                     /* Will begin DMA later */
1776                 set_bit(PC_DMA_IN_PROGRESS, &pc->flags);
1777         if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) {
1778                 ide_execute_command(drive, WIN_PACKETCMD, &idetape_transfer_pc,
1779                                     IDETAPE_WAIT_CMD, NULL);
1780                 return ide_started;
1781         } else {
1782                 hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
1783                 return idetape_transfer_pc(drive);
1784         }
1785 }
1786
1787 /*
1788  *      General packet command callback function.
1789  */
1790 static ide_startstop_t idetape_pc_callback (ide_drive_t *drive)
1791 {
1792         idetape_tape_t *tape = drive->driver_data;
1793
1794 #if IDETAPE_DEBUG_LOG
1795         if (tape->debug_level >= 4)
1796                 printk(KERN_INFO "ide-tape: Reached idetape_pc_callback\n");
1797 #endif /* IDETAPE_DEBUG_LOG */
1798
1799         idetape_end_request(drive, tape->pc->error ? 0 : 1, 0);
1800         return ide_stopped;
1801 }
1802
1803 /*
1804  *      A mode sense command is used to "sense" tape parameters.
1805  */
1806 static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code)
1807 {
1808         idetape_init_pc(pc);
1809         pc->c[0] = IDETAPE_MODE_SENSE_CMD;
1810         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
1811                 pc->c[1] = 8;   /* DBD = 1 - Don't return block descriptors */
1812         pc->c[2] = page_code;
1813         /*
1814          * Changed pc->c[3] to 0 (255 will at best return unused info).
1815          *
1816          * For SCSI this byte is defined as subpage instead of high byte
1817          * of length and some IDE drives seem to interpret it this way
1818          * and return an error when 255 is used.
1819          */
1820         pc->c[3] = 0;
1821         pc->c[4] = 255;         /* (We will just discard data in that case) */
1822         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
1823                 pc->request_transfer = 12;
1824         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
1825                 pc->request_transfer = 24;
1826         else
1827                 pc->request_transfer = 50;
1828         pc->callback = &idetape_pc_callback;
1829 }
1830
1831 static void calculate_speeds(ide_drive_t *drive)
1832 {
1833         idetape_tape_t *tape = drive->driver_data;
1834         int full = 125, empty = 75;
1835
1836         if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) {
1837                 tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head;
1838                 tape->controlled_previous_head_time = tape->controlled_pipeline_head_time;
1839                 tape->controlled_last_pipeline_head = tape->pipeline_head;
1840                 tape->controlled_pipeline_head_time = jiffies;
1841         }
1842         if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
1843                 tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time);
1844         else if (time_after(jiffies, tape->controlled_previous_head_time))
1845                 tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time);
1846
1847         if (tape->nr_pending_stages < tape->max_stages /*- 1 */) {
1848                 /* -1 for read mode error recovery */
1849                 if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) {
1850                         tape->uncontrolled_pipeline_head_time = jiffies;
1851                         tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time);
1852                 }
1853         } else {
1854                 tape->uncontrolled_previous_head_time = jiffies;
1855                 tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
1856                 if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) {
1857                         tape->uncontrolled_pipeline_head_time = jiffies;
1858                 }
1859         }
1860         tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed);
1861         if (tape->speed_control == 0) {
1862                 tape->max_insert_speed = 5000;
1863         } else if (tape->speed_control == 1) {
1864                 if (tape->nr_pending_stages >= tape->max_stages / 2)
1865                         tape->max_insert_speed = tape->pipeline_head_speed +
1866                                 (1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages;
1867                 else
1868                         tape->max_insert_speed = 500 +
1869                                 (tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages;
1870                 if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
1871                         tape->max_insert_speed = 5000;
1872         } else if (tape->speed_control == 2) {
1873                 tape->max_insert_speed = tape->pipeline_head_speed * empty / 100 +
1874                         (tape->pipeline_head_speed * full / 100 - tape->pipeline_head_speed * empty / 100) * tape->nr_pending_stages / tape->max_stages;
1875         } else
1876                 tape->max_insert_speed = tape->speed_control;
1877         tape->max_insert_speed = max(tape->max_insert_speed, 500);
1878 }
1879
1880 static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive)
1881 {
1882         idetape_tape_t *tape = drive->driver_data;
1883         idetape_pc_t *pc = tape->pc;
1884         u8 stat;
1885
1886         stat = drive->hwif->INB(IDE_STATUS_REG);
1887         if (stat & SEEK_STAT) {
1888                 if (stat & ERR_STAT) {
1889                         /* Error detected */
1890                         if (pc->c[0] != IDETAPE_TEST_UNIT_READY_CMD)
1891                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
1892                                                 tape->name);
1893                         /* Retry operation */
1894                         return idetape_retry_pc(drive);
1895                 }
1896                 pc->error = 0;
1897                 if (tape->failed_pc == pc)
1898                         tape->failed_pc = NULL;
1899         } else {
1900                 pc->error = IDETAPE_ERROR_GENERAL;
1901                 tape->failed_pc = NULL;
1902         }
1903         return pc->callback(drive);
1904 }
1905
1906 static ide_startstop_t idetape_rw_callback (ide_drive_t *drive)
1907 {
1908         idetape_tape_t *tape = drive->driver_data;
1909         struct request *rq = HWGROUP(drive)->rq;
1910         int blocks = tape->pc->actually_transferred / tape->tape_block_size;
1911
1912         tape->avg_size += blocks * tape->tape_block_size;
1913         tape->insert_size += blocks * tape->tape_block_size;
1914         if (tape->insert_size > 1024 * 1024)
1915                 tape->measure_insert_time = 1;
1916         if (tape->measure_insert_time) {
1917                 tape->measure_insert_time = 0;
1918                 tape->insert_time = jiffies;
1919                 tape->insert_size = 0;
1920         }
1921         if (time_after(jiffies, tape->insert_time))
1922                 tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
1923         if (time_after_eq(jiffies, tape->avg_time + HZ)) {
1924                 tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024;
1925                 tape->avg_size = 0;
1926                 tape->avg_time = jiffies;
1927         }
1928
1929 #if IDETAPE_DEBUG_LOG
1930         if (tape->debug_level >= 4)
1931                 printk(KERN_INFO "ide-tape: Reached idetape_rw_callback\n");
1932 #endif /* IDETAPE_DEBUG_LOG */
1933
1934         tape->first_frame_position += blocks;
1935         rq->current_nr_sectors -= blocks;
1936
1937         if (!tape->pc->error)
1938                 idetape_end_request(drive, 1, 0);
1939         else
1940                 idetape_end_request(drive, tape->pc->error, 0);
1941         return ide_stopped;
1942 }
1943
1944 static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
1945 {
1946         idetape_init_pc(pc);
1947         pc->c[0] = IDETAPE_READ_CMD;
1948         put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
1949         pc->c[1] = 1;
1950         pc->callback = &idetape_rw_callback;
1951         pc->bh = bh;
1952         atomic_set(&bh->b_count, 0);
1953         pc->buffer = NULL;
1954         pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
1955         if (pc->request_transfer == tape->stage_size)
1956                 set_bit(PC_DMA_RECOMMENDED, &pc->flags);
1957 }
1958
1959 static void idetape_create_read_buffer_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
1960 {
1961         int size = 32768;
1962         struct idetape_bh *p = bh;
1963
1964         idetape_init_pc(pc);
1965         pc->c[0] = IDETAPE_READ_BUFFER_CMD;
1966         pc->c[1] = IDETAPE_RETRIEVE_FAULTY_BLOCK;
1967         pc->c[7] = size >> 8;
1968         pc->c[8] = size & 0xff;
1969         pc->callback = &idetape_pc_callback;
1970         pc->bh = bh;
1971         atomic_set(&bh->b_count, 0);
1972         pc->buffer = NULL;
1973         while (p) {
1974                 atomic_set(&p->b_count, 0);
1975                 p = p->b_reqnext;
1976         }
1977         pc->request_transfer = pc->buffer_size = size;
1978 }
1979
1980 static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
1981 {
1982         idetape_init_pc(pc);
1983         pc->c[0] = IDETAPE_WRITE_CMD;
1984         put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
1985         pc->c[1] = 1;
1986         pc->callback = &idetape_rw_callback;
1987         set_bit(PC_WRITING, &pc->flags);
1988         pc->bh = bh;
1989         pc->b_data = bh->b_data;
1990         pc->b_count = atomic_read(&bh->b_count);
1991         pc->buffer = NULL;
1992         pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
1993         if (pc->request_transfer == tape->stage_size)
1994                 set_bit(PC_DMA_RECOMMENDED, &pc->flags);
1995 }
1996
1997 /*
1998  * idetape_do_request is our request handling function.
1999  */
2000 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
2001                                           struct request *rq, sector_t block)
2002 {
2003         idetape_tape_t *tape = drive->driver_data;
2004         idetape_pc_t *pc = NULL;
2005         struct request *postponed_rq = tape->postponed_rq;
2006         u8 stat;
2007
2008 #if IDETAPE_DEBUG_LOG
2009 #if 0
2010         if (tape->debug_level >= 5)
2011                 printk(KERN_INFO "ide-tape:  %d, "
2012                         "dev: %s, cmd: %ld, errors: %d\n",
2013                          rq->rq_disk->disk_name, rq->cmd[0], rq->errors);
2014 #endif
2015         if (tape->debug_level >= 2)
2016                 printk(KERN_INFO "ide-tape: sector: %ld, "
2017                         "nr_sectors: %ld, current_nr_sectors: %d\n",
2018                         rq->sector, rq->nr_sectors, rq->current_nr_sectors);
2019 #endif /* IDETAPE_DEBUG_LOG */
2020
2021         if (!blk_special_request(rq)) {
2022                 /*
2023                  * We do not support buffer cache originated requests.
2024                  */
2025                 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
2026                         "request queue (%d)\n", drive->name, rq->cmd_type);
2027                 ide_end_request(drive, 0, 0);
2028                 return ide_stopped;
2029         }
2030
2031         /*
2032          *      Retry a failed packet command
2033          */
2034         if (tape->failed_pc != NULL &&
2035             tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
2036                 return idetape_issue_packet_command(drive, tape->failed_pc);
2037         }
2038 #if IDETAPE_DEBUG_BUGS
2039         if (postponed_rq != NULL)
2040                 if (rq != postponed_rq) {
2041                         printk(KERN_ERR "ide-tape: ide-tape.c bug - "
2042                                         "Two DSC requests were queued\n");
2043                         idetape_end_request(drive, 0, 0);
2044                         return ide_stopped;
2045                 }
2046 #endif /* IDETAPE_DEBUG_BUGS */
2047
2048         tape->postponed_rq = NULL;
2049
2050         /*
2051          * If the tape is still busy, postpone our request and service
2052          * the other device meanwhile.
2053          */
2054         stat = drive->hwif->INB(IDE_STATUS_REG);
2055
2056         if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2))
2057                 set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
2058
2059         if (drive->post_reset == 1) {
2060                 set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
2061                 drive->post_reset = 0;
2062         }
2063
2064         if (tape->tape_still_time > 100 && tape->tape_still_time < 200)
2065                 tape->measure_insert_time = 1;
2066         if (time_after(jiffies, tape->insert_time))
2067                 tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
2068         calculate_speeds(drive);
2069         if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) &&
2070             (stat & SEEK_STAT) == 0) {
2071                 if (postponed_rq == NULL) {
2072                         tape->dsc_polling_start = jiffies;
2073                         tape->dsc_polling_frequency = tape->best_dsc_rw_frequency;
2074                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
2075                 } else if (time_after(jiffies, tape->dsc_timeout)) {
2076                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
2077                                 tape->name);
2078                         if (rq->cmd[0] & REQ_IDETAPE_PC2) {
2079                                 idetape_media_access_finished(drive);
2080                                 return ide_stopped;
2081                         } else {
2082                                 return ide_do_reset(drive);
2083                         }
2084                 } else if (time_after(jiffies, tape->dsc_polling_start + IDETAPE_DSC_MA_THRESHOLD))
2085                         tape->dsc_polling_frequency = IDETAPE_DSC_MA_SLOW;
2086                 idetape_postpone_request(drive);
2087                 return ide_stopped;
2088         }
2089         if (rq->cmd[0] & REQ_IDETAPE_READ) {
2090                 tape->buffer_head++;
2091                 tape->postpone_cnt = 0;
2092                 pc = idetape_next_pc_storage(drive);
2093                 idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
2094                 goto out;
2095         }
2096         if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
2097                 tape->buffer_head++;
2098                 tape->postpone_cnt = 0;
2099                 pc = idetape_next_pc_storage(drive);
2100                 idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
2101                 goto out;
2102         }
2103         if (rq->cmd[0] & REQ_IDETAPE_READ_BUFFER) {
2104                 tape->postpone_cnt = 0;
2105                 pc = idetape_next_pc_storage(drive);
2106                 idetape_create_read_buffer_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
2107                 goto out;
2108         }
2109         if (rq->cmd[0] & REQ_IDETAPE_PC1) {
2110                 pc = (idetape_pc_t *) rq->buffer;
2111                 rq->cmd[0] &= ~(REQ_IDETAPE_PC1);
2112                 rq->cmd[0] |= REQ_IDETAPE_PC2;
2113                 goto out;
2114         }
2115         if (rq->cmd[0] & REQ_IDETAPE_PC2) {
2116                 idetape_media_access_finished(drive);
2117                 return ide_stopped;
2118         }
2119         BUG();
2120 out:
2121         return idetape_issue_packet_command(drive, pc);
2122 }
2123
2124 /*
2125  *      Pipeline related functions
2126  */
2127 static inline int idetape_pipeline_active (idetape_tape_t *tape)
2128 {
2129         int rc1, rc2;
2130
2131         rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
2132         rc2 = (tape->active_data_request != NULL);
2133         return rc1;
2134 }
2135
2136 /*
2137  *      idetape_kmalloc_stage uses __get_free_page to allocate a pipeline
2138  *      stage, along with all the necessary small buffers which together make
2139  *      a buffer of size tape->stage_size (or a bit more). We attempt to
2140  *      combine sequential pages as much as possible.
2141  *
2142  *      Returns a pointer to the new allocated stage, or NULL if we
2143  *      can't (or don't want to) allocate a stage.
2144  *
2145  *      Pipeline stages are optional and are used to increase performance.
2146  *      If we can't allocate them, we'll manage without them.
2147  */
2148 static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape, int full, int clear)
2149 {
2150         idetape_stage_t *stage;
2151         struct idetape_bh *prev_bh, *bh;
2152         int pages = tape->pages_per_stage;
2153         char *b_data = NULL;
2154
2155         if ((stage = kmalloc(sizeof (idetape_stage_t),GFP_KERNEL)) == NULL)
2156                 return NULL;
2157         stage->next = NULL;
2158
2159         bh = stage->bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
2160         if (bh == NULL)
2161                 goto abort;
2162         bh->b_reqnext = NULL;
2163         if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
2164                 goto abort;
2165         if (clear)
2166                 memset(bh->b_data, 0, PAGE_SIZE);
2167         bh->b_size = PAGE_SIZE;
2168         atomic_set(&bh->b_count, full ? bh->b_size : 0);
2169
2170         while (--pages) {
2171                 if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
2172                         goto abort;
2173                 if (clear)
2174                         memset(b_data, 0, PAGE_SIZE);
2175                 if (bh->b_data == b_data + PAGE_SIZE) {
2176                         bh->b_size += PAGE_SIZE;
2177                         bh->b_data -= PAGE_SIZE;
2178                         if (full)
2179                                 atomic_add(PAGE_SIZE, &bh->b_count);
2180                         continue;
2181                 }
2182                 if (b_data == bh->b_data + bh->b_size) {
2183                         bh->b_size += PAGE_SIZE;
2184                         if (full)
2185                                 atomic_add(PAGE_SIZE, &bh->b_count);
2186                         continue;
2187                 }
2188                 prev_bh = bh;
2189                 if ((bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL)) == NULL) {
2190                         free_page((unsigned long) b_data);
2191                         goto abort;
2192                 }
2193                 bh->b_reqnext = NULL;
2194                 bh->b_data = b_data;
2195                 bh->b_size = PAGE_SIZE;
2196                 atomic_set(&bh->b_count, full ? bh->b_size : 0);
2197                 prev_bh->b_reqnext = bh;
2198         }
2199         bh->b_size -= tape->excess_bh_size;
2200         if (full)
2201                 atomic_sub(tape->excess_bh_size, &bh->b_count);
2202         return stage;
2203 abort:
2204         __idetape_kfree_stage(stage);
2205         return NULL;
2206 }
2207
2208 static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape)
2209 {
2210         idetape_stage_t *cache_stage = tape->cache_stage;
2211
2212 #if IDETAPE_DEBUG_LOG
2213         if (tape->debug_level >= 4)
2214                 printk(KERN_INFO "ide-tape: Reached idetape_kmalloc_stage\n");
2215 #endif /* IDETAPE_DEBUG_LOG */
2216
2217         if (tape->nr_stages >= tape->max_stages)
2218                 return NULL;
2219         if (cache_stage != NULL) {
2220                 tape->cache_stage = NULL;
2221                 return cache_stage;
2222         }
2223         return __idetape_kmalloc_stage(tape, 0, 0);
2224 }
2225
2226 static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
2227 {
2228         struct idetape_bh *bh = tape->bh;
2229         int count;
2230         int ret = 0;
2231
2232         while (n) {
2233 #if IDETAPE_DEBUG_BUGS
2234                 if (bh == NULL) {
2235                         printk(KERN_ERR "ide-tape: bh == NULL in "
2236                                 "idetape_copy_stage_from_user\n");
2237                         return 1;
2238                 }
2239 #endif /* IDETAPE_DEBUG_BUGS */
2240                 count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
2241                 if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count))
2242                         ret = 1;
2243                 n -= count;
2244                 atomic_add(count, &bh->b_count);
2245                 buf += count;
2246                 if (atomic_read(&bh->b_count) == bh->b_size) {
2247                         bh = bh->b_reqnext;
2248                         if (bh)
2249                                 atomic_set(&bh->b_count, 0);
2250                 }
2251         }
2252         tape->bh = bh;
2253         return ret;
2254 }
2255
2256 static int idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
2257 {
2258         struct idetape_bh *bh = tape->bh;
2259         int count;
2260         int ret = 0;
2261
2262         while (n) {
2263 #if IDETAPE_DEBUG_BUGS
2264                 if (bh == NULL) {
2265                         printk(KERN_ERR "ide-tape: bh == NULL in "
2266                                 "idetape_copy_stage_to_user\n");
2267                         return 1;
2268                 }
2269 #endif /* IDETAPE_DEBUG_BUGS */
2270                 count = min(tape->b_count, n);
2271                 if  (copy_to_user(buf, tape->b_data, count))
2272                         ret = 1;
2273                 n -= count;
2274                 tape->b_data += count;
2275                 tape->b_count -= count;
2276                 buf += count;
2277                 if (!tape->b_count) {
2278                         tape->bh = bh = bh->b_reqnext;
2279                         if (bh) {
2280                                 tape->b_data = bh->b_data;
2281                                 tape->b_count = atomic_read(&bh->b_count);
2282                         }
2283                 }
2284         }
2285         return ret;
2286 }
2287
2288 static void idetape_init_merge_stage (idetape_tape_t *tape)
2289 {
2290         struct idetape_bh *bh = tape->merge_stage->bh;
2291
2292         tape->bh = bh;
2293         if (tape->chrdev_direction == idetape_direction_write)
2294                 atomic_set(&bh->b_count, 0);
2295         else {
2296                 tape->b_data = bh->b_data;
2297                 tape->b_count = atomic_read(&bh->b_count);
2298         }
2299 }
2300
2301 static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage)
2302 {
2303         struct idetape_bh *tmp;
2304
2305         tmp = stage->bh;
2306         stage->bh = tape->merge_stage->bh;
2307         tape->merge_stage->bh = tmp;
2308         idetape_init_merge_stage(tape);
2309 }
2310
2311 /*
2312  *      idetape_add_stage_tail adds a new stage at the end of the pipeline.
2313  */
2314 static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage)
2315 {
2316         idetape_tape_t *tape = drive->driver_data;
2317         unsigned long flags;
2318
2319 #if IDETAPE_DEBUG_LOG
2320         if (tape->debug_level >= 4)
2321                 printk (KERN_INFO "ide-tape: Reached idetape_add_stage_tail\n");
2322 #endif /* IDETAPE_DEBUG_LOG */
2323         spin_lock_irqsave(&tape->spinlock, flags);
2324         stage->next = NULL;
2325         if (tape->last_stage != NULL)
2326                 tape->last_stage->next=stage;
2327         else
2328                 tape->first_stage = tape->next_stage=stage;
2329         tape->last_stage = stage;
2330         if (tape->next_stage == NULL)
2331                 tape->next_stage = tape->last_stage;
2332         tape->nr_stages++;
2333         tape->nr_pending_stages++;
2334         spin_unlock_irqrestore(&tape->spinlock, flags);
2335 }
2336
2337 /*
2338  *      idetape_wait_for_request installs a completion in a pending request
2339  *      and sleeps until it is serviced.
2340  *
2341  *      The caller should ensure that the request will not be serviced
2342  *      before we install the completion (usually by disabling interrupts).
2343  */
2344 static void idetape_wait_for_request (ide_drive_t *drive, struct request *rq)
2345 {
2346         DECLARE_COMPLETION_ONSTACK(wait);
2347         idetape_tape_t *tape = drive->driver_data;
2348
2349 #if IDETAPE_DEBUG_BUGS
2350         if (rq == NULL || !blk_special_request(rq)) {
2351                 printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n");
2352                 return;
2353         }
2354 #endif /* IDETAPE_DEBUG_BUGS */
2355         rq->end_io_data = &wait;
2356         rq->end_io = blk_end_sync_rq;
2357         spin_unlock_irq(&tape->spinlock);
2358         wait_for_completion(&wait);
2359         /* The stage and its struct request have been deallocated */
2360         spin_lock_irq(&tape->spinlock);
2361 }
2362
2363 static ide_startstop_t idetape_read_position_callback (ide_drive_t *drive)
2364 {
2365         idetape_tape_t *tape = drive->driver_data;
2366         idetape_read_position_result_t *result;
2367
2368 #if IDETAPE_DEBUG_LOG
2369         if (tape->debug_level >= 4)
2370                 printk(KERN_INFO "ide-tape: Reached idetape_read_position_callback\n");
2371 #endif /* IDETAPE_DEBUG_LOG */
2372
2373         if (!tape->pc->error) {
2374                 result = (idetape_read_position_result_t *) tape->pc->buffer;
2375 #if IDETAPE_DEBUG_LOG
2376                 if (tape->debug_level >= 2)
2377                         printk(KERN_INFO "ide-tape: BOP - %s\n",result->bop ? "Yes":"No");
2378                 if (tape->debug_level >= 2)
2379                         printk(KERN_INFO "ide-tape: EOP - %s\n",result->eop ? "Yes":"No");
2380 #endif /* IDETAPE_DEBUG_LOG */
2381                 if (result->bpu) {
2382                         printk(KERN_INFO "ide-tape: Block location is unknown to the tape\n");
2383                         clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
2384                         idetape_end_request(drive, 0, 0);
2385                 } else {
2386 #if IDETAPE_DEBUG_LOG
2387                         if (tape->debug_level >= 2)
2388                                 printk(KERN_INFO "ide-tape: Block Location - %u\n", ntohl(result->first_block));
2389 #endif /* IDETAPE_DEBUG_LOG */
2390                         tape->partition = result->partition;
2391                         tape->first_frame_position = ntohl(result->first_block);
2392                         tape->last_frame_position = ntohl(result->last_block);
2393                         tape->blocks_in_buffer = result->blocks_in_buffer[2];
2394                         set_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
2395                         idetape_end_request(drive, 1, 0);
2396                 }
2397         } else {
2398                 idetape_end_request(drive, 0, 0);
2399         }
2400         return ide_stopped;
2401 }
2402
2403 /*
2404  *      idetape_create_write_filemark_cmd will:
2405  *
2406  *              1.      Write a filemark if write_filemark=1.
2407  *              2.      Flush the device buffers without writing a filemark
2408  *                      if write_filemark=0.
2409  *
2410  */
2411 static void idetape_create_write_filemark_cmd (ide_drive_t *drive, idetape_pc_t *pc,int write_filemark)
2412 {
2413         idetape_init_pc(pc);
2414         pc->c[0] = IDETAPE_WRITE_FILEMARK_CMD;
2415         pc->c[4] = write_filemark;
2416         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2417         pc->callback = &idetape_pc_callback;
2418 }
2419
2420 static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc)
2421 {
2422         idetape_init_pc(pc);
2423         pc->c[0] = IDETAPE_TEST_UNIT_READY_CMD;
2424         pc->callback = &idetape_pc_callback;
2425 }
2426
2427 /*
2428  *      idetape_queue_pc_tail is based on the following functions:
2429  *
2430  *      ide_do_drive_cmd from ide.c
2431  *      cdrom_queue_request and cdrom_queue_packet_command from ide-cd.c
2432  *
2433  *      We add a special packet command request to the tail of the request
2434  *      queue, and wait for it to be serviced.
2435  *
2436  *      This is not to be called from within the request handling part
2437  *      of the driver ! We allocate here data in the stack, and it is valid
2438  *      until the request is finished. This is not the case for the bottom
2439  *      part of the driver, where we are always leaving the functions to wait
2440  *      for an interrupt or a timer event.
2441  *
2442  *      From the bottom part of the driver, we should allocate safe memory
2443  *      using idetape_next_pc_storage and idetape_next_rq_storage, and add
2444  *      the request to the request list without waiting for it to be serviced !
2445  *      In that case, we usually use idetape_queue_pc_head.
2446  */
2447 static int __idetape_queue_pc_tail (ide_drive_t *drive, idetape_pc_t *pc)
2448 {
2449         struct ide_tape_obj *tape = drive->driver_data;
2450         struct request rq;
2451
2452         idetape_init_rq(&rq, REQ_IDETAPE_PC1);
2453         rq.buffer = (char *) pc;
2454         rq.rq_disk = tape->disk;
2455         return ide_do_drive_cmd(drive, &rq, ide_wait);
2456 }
2457
2458 static void idetape_create_load_unload_cmd (ide_drive_t *drive, idetape_pc_t *pc,int cmd)
2459 {
2460         idetape_init_pc(pc);
2461         pc->c[0] = IDETAPE_LOAD_UNLOAD_CMD;
2462         pc->c[4] = cmd;
2463         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2464         pc->callback = &idetape_pc_callback;
2465 }
2466
2467 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
2468 {
2469         idetape_tape_t *tape = drive->driver_data;
2470         idetape_pc_t pc;
2471         int load_attempted = 0;
2472
2473         /*
2474          * Wait for the tape to become ready
2475          */
2476         set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
2477         timeout += jiffies;
2478         while (time_before(jiffies, timeout)) {
2479                 idetape_create_test_unit_ready_cmd(&pc);
2480                 if (!__idetape_queue_pc_tail(drive, &pc))
2481                         return 0;
2482                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
2483                     || (tape->asc == 0x3A)) {   /* no media */
2484                         if (load_attempted)
2485                                 return -ENOMEDIUM;
2486                         idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
2487                         __idetape_queue_pc_tail(drive, &pc);
2488                         load_attempted = 1;
2489                 /* not about to be ready */
2490                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
2491                              (tape->ascq == 1 || tape->ascq == 8)))
2492                         return -EIO;
2493                 msleep(100);
2494         }
2495         return -EIO;
2496 }
2497
2498 static int idetape_queue_pc_tail (ide_drive_t *drive,idetape_pc_t *pc)
2499 {
2500         return __idetape_queue_pc_tail(drive, pc);
2501 }
2502
2503 static int idetape_flush_tape_buffers (ide_drive_t *drive)
2504 {
2505         idetape_pc_t pc;
2506         int rc;
2507
2508         idetape_create_write_filemark_cmd(drive, &pc, 0);
2509         if ((rc = idetape_queue_pc_tail(drive, &pc)))
2510                 return rc;
2511         idetape_wait_ready(drive, 60 * 5 * HZ);
2512         return 0;
2513 }
2514
2515 static void idetape_create_read_position_cmd (idetape_pc_t *pc)
2516 {
2517         idetape_init_pc(pc);
2518         pc->c[0] = IDETAPE_READ_POSITION_CMD;
2519         pc->request_transfer = 20;
2520         pc->callback = &idetape_read_position_callback;
2521 }
2522
2523 static int idetape_read_position (ide_drive_t *drive)
2524 {
2525         idetape_tape_t *tape = drive->driver_data;
2526         idetape_pc_t pc;
2527         int position;
2528
2529 #if IDETAPE_DEBUG_LOG
2530         if (tape->debug_level >= 4)
2531                 printk(KERN_INFO "ide-tape: Reached idetape_read_position\n");
2532 #endif /* IDETAPE_DEBUG_LOG */
2533
2534         idetape_create_read_position_cmd(&pc);
2535         if (idetape_queue_pc_tail(drive, &pc))
2536                 return -1;
2537         position = tape->first_frame_position;
2538         return position;
2539 }
2540
2541 static void idetape_create_locate_cmd (ide_drive_t *drive, idetape_pc_t *pc, unsigned int block, u8 partition, int skip)
2542 {
2543         idetape_init_pc(pc);
2544         pc->c[0] = IDETAPE_LOCATE_CMD;
2545         pc->c[1] = 2;
2546         put_unaligned(htonl(block), (unsigned int *) &pc->c[3]);
2547         pc->c[8] = partition;
2548         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2549         pc->callback = &idetape_pc_callback;
2550 }
2551
2552 static int idetape_create_prevent_cmd (ide_drive_t *drive, idetape_pc_t *pc, int prevent)
2553 {
2554         idetape_tape_t *tape = drive->driver_data;
2555
2556         if (!tape->capabilities.lock)
2557                 return 0;
2558
2559         idetape_init_pc(pc);
2560         pc->c[0] = IDETAPE_PREVENT_CMD;
2561         pc->c[4] = prevent;
2562         pc->callback = &idetape_pc_callback;
2563         return 1;
2564 }
2565
2566 static int __idetape_discard_read_pipeline (ide_drive_t *drive)
2567 {
2568         idetape_tape_t *tape = drive->driver_data;
2569         unsigned long flags;
2570         int cnt;
2571
2572         if (tape->chrdev_direction != idetape_direction_read)
2573                 return 0;
2574
2575         /* Remove merge stage. */
2576         cnt = tape->merge_stage_size / tape->tape_block_size;
2577         if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
2578                 ++cnt;          /* Filemarks count as 1 sector */
2579         tape->merge_stage_size = 0;
2580         if (tape->merge_stage != NULL) {
2581                 __idetape_kfree_stage(tape->merge_stage);
2582                 tape->merge_stage = NULL;
2583         }
2584
2585         /* Clear pipeline flags. */
2586         clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
2587         tape->chrdev_direction = idetape_direction_none;
2588
2589         /* Remove pipeline stages. */
2590         if (tape->first_stage == NULL)
2591                 return 0;
2592
2593         spin_lock_irqsave(&tape->spinlock, flags);
2594         tape->next_stage = NULL;
2595         if (idetape_pipeline_active(tape))
2596                 idetape_wait_for_request(drive, tape->active_data_request);
2597         spin_unlock_irqrestore(&tape->spinlock, flags);
2598
2599         while (tape->first_stage != NULL) {
2600                 struct request *rq_ptr = &tape->first_stage->rq;
2601
2602                 cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors;
2603                 if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
2604                         ++cnt;
2605                 idetape_remove_stage_head(drive);
2606         }
2607         tape->nr_pending_stages = 0;
2608         tape->max_stages = tape->min_pipeline;
2609         return cnt;
2610 }
2611
2612 /*
2613  *      idetape_position_tape positions the tape to the requested block
2614  *      using the LOCATE packet command. A READ POSITION command is then
2615  *      issued to check where we are positioned.
2616  *
2617  *      Like all higher level operations, we queue the commands at the tail
2618  *      of the request queue and wait for their completion.
2619  *
2620  */
2621 static int idetape_position_tape (ide_drive_t *drive, unsigned int block, u8 partition, int skip)
2622 {
2623         idetape_tape_t *tape = drive->driver_data;
2624         int retval;
2625         idetape_pc_t pc;
2626
2627         if (tape->chrdev_direction == idetape_direction_read)
2628                 __idetape_discard_read_pipeline(drive);
2629         idetape_wait_ready(drive, 60 * 5 * HZ);
2630         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
2631         retval = idetape_queue_pc_tail(drive, &pc);
2632         if (retval)
2633                 return (retval);
2634
2635         idetape_create_read_position_cmd(&pc);
2636         return (idetape_queue_pc_tail(drive, &pc));
2637 }
2638
2639 static void idetape_discard_read_pipeline (ide_drive_t *drive, int restore_position)
2640 {
2641         idetape_tape_t *tape = drive->driver_data;
2642         int cnt;
2643         int seek, position;
2644
2645         cnt = __idetape_discard_read_pipeline(drive);
2646         if (restore_position) {
2647                 position = idetape_read_position(drive);
2648                 seek = position > cnt ? position - cnt : 0;
2649                 if (idetape_position_tape(drive, seek, 0, 0)) {
2650                         printk(KERN_INFO "ide-tape: %s: position_tape failed in discard_pipeline()\n", tape->name);
2651                         return;
2652                 }
2653         }
2654 }
2655
2656 /*
2657  * idetape_queue_rw_tail generates a read/write request for the block
2658  * device interface and wait for it to be serviced.
2659  */
2660 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, struct idetape_bh *bh)
2661 {
2662         idetape_tape_t *tape = drive->driver_data;
2663         struct request rq;
2664
2665 #if IDETAPE_DEBUG_LOG
2666         if (tape->debug_level >= 2)
2667                 printk(KERN_INFO "ide-tape: idetape_queue_rw_tail: cmd=%d\n",cmd);
2668 #endif /* IDETAPE_DEBUG_LOG */
2669 #if IDETAPE_DEBUG_BUGS
2670         if (idetape_pipeline_active(tape)) {
2671                 printk(KERN_ERR "ide-tape: bug: the pipeline is active in idetape_queue_rw_tail\n");
2672                 return (0);
2673         }
2674 #endif /* IDETAPE_DEBUG_BUGS */
2675
2676         idetape_init_rq(&rq, cmd);
2677         rq.rq_disk = tape->disk;
2678         rq.special = (void *)bh;
2679         rq.sector = tape->first_frame_position;
2680         rq.nr_sectors = rq.current_nr_sectors = blocks;
2681         (void) ide_do_drive_cmd(drive, &rq, ide_wait);
2682
2683         if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
2684                 return 0;
2685
2686         if (tape->merge_stage)
2687                 idetape_init_merge_stage(tape);
2688         if (rq.errors == IDETAPE_ERROR_GENERAL)
2689                 return -EIO;
2690         return (tape->tape_block_size * (blocks-rq.current_nr_sectors));
2691 }
2692
2693 /*
2694  *      idetape_insert_pipeline_into_queue is used to start servicing the
2695  *      pipeline stages, starting from tape->next_stage.
2696  */
2697 static void idetape_insert_pipeline_into_queue (ide_drive_t *drive)
2698 {
2699         idetape_tape_t *tape = drive->driver_data;
2700
2701         if (tape->next_stage == NULL)
2702                 return;
2703         if (!idetape_pipeline_active(tape)) {
2704                 set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
2705                 idetape_active_next_stage(drive);
2706                 (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
2707         }
2708 }
2709
2710 static void idetape_create_inquiry_cmd (idetape_pc_t *pc)
2711 {
2712         idetape_init_pc(pc);
2713         pc->c[0] = IDETAPE_INQUIRY_CMD;
2714         pc->c[4] = pc->request_transfer = 254;
2715         pc->callback = &idetape_pc_callback;
2716 }
2717
2718 static void idetape_create_rewind_cmd (ide_drive_t *drive, idetape_pc_t *pc)
2719 {
2720         idetape_init_pc(pc);
2721         pc->c[0] = IDETAPE_REWIND_CMD;
2722         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2723         pc->callback = &idetape_pc_callback;
2724 }
2725
2726 #if 0
2727 static void idetape_create_mode_select_cmd (idetape_pc_t *pc, int length)
2728 {
2729         idetape_init_pc(pc);
2730         set_bit(PC_WRITING, &pc->flags);
2731         pc->c[0] = IDETAPE_MODE_SELECT_CMD;
2732         pc->c[1] = 0x10;
2733         put_unaligned(htons(length), (unsigned short *) &pc->c[3]);
2734         pc->request_transfer = 255;
2735         pc->callback = &idetape_pc_callback;
2736 }
2737 #endif
2738
2739 static void idetape_create_erase_cmd (idetape_pc_t *pc)
2740 {
2741         idetape_init_pc(pc);
2742         pc->c[0] = IDETAPE_ERASE_CMD;
2743         pc->c[1] = 1;
2744         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2745         pc->callback = &idetape_pc_callback;
2746 }
2747
2748 static void idetape_create_space_cmd (idetape_pc_t *pc,int count, u8 cmd)
2749 {
2750         idetape_init_pc(pc);
2751         pc->c[0] = IDETAPE_SPACE_CMD;
2752         put_unaligned(htonl(count), (unsigned int *) &pc->c[1]);
2753         pc->c[1] = cmd;
2754         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2755         pc->callback = &idetape_pc_callback;
2756 }
2757
2758 static void idetape_wait_first_stage (ide_drive_t *drive)
2759 {
2760         idetape_tape_t *tape = drive->driver_data;
2761         unsigned long flags;
2762
2763         if (tape->first_stage == NULL)
2764                 return;
2765         spin_lock_irqsave(&tape->spinlock, flags);
2766         if (tape->active_stage == tape->first_stage)
2767                 idetape_wait_for_request(drive, tape->active_data_request);
2768         spin_unlock_irqrestore(&tape->spinlock, flags);
2769 }
2770
2771 /*
2772  *      idetape_add_chrdev_write_request tries to add a character device
2773  *      originated write request to our pipeline. In case we don't succeed,
2774  *      we revert to non-pipelined operation mode for this request.
2775  *
2776  *      1.      Try to allocate a new pipeline stage.
2777  *      2.      If we can't, wait for more and more requests to be serviced
2778  *              and try again each time.
2779  *      3.      If we still can't allocate a stage, fallback to
2780  *              non-pipelined operation mode for this request.
2781  */
2782 static int idetape_add_chrdev_write_request (ide_drive_t *drive, int blocks)
2783 {
2784         idetape_tape_t *tape = drive->driver_data;
2785         idetape_stage_t *new_stage;
2786         unsigned long flags;
2787         struct request *rq;
2788
2789 #if IDETAPE_DEBUG_LOG
2790         if (tape->debug_level >= 3)
2791                 printk(KERN_INFO "ide-tape: Reached idetape_add_chrdev_write_request\n");
2792 #endif /* IDETAPE_DEBUG_LOG */
2793
2794         /*
2795          *      Attempt to allocate a new stage.
2796          *      Pay special attention to possible race conditions.
2797          */
2798         while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) {
2799                 spin_lock_irqsave(&tape->spinlock, flags);
2800                 if (idetape_pipeline_active(tape)) {
2801                         idetape_wait_for_request(drive, tape->active_data_request);
2802                         spin_unlock_irqrestore(&tape->spinlock, flags);
2803                 } else {
2804                         spin_unlock_irqrestore(&tape->spinlock, flags);
2805                         idetape_insert_pipeline_into_queue(drive);
2806                         if (idetape_pipeline_active(tape))
2807                                 continue;
2808                         /*
2809                          *      Linux is short on memory. Fallback to
2810                          *      non-pipelined operation mode for this request.
2811                          */
2812                         return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
2813                 }
2814         }
2815         rq = &new_stage->rq;
2816         idetape_init_rq(rq, REQ_IDETAPE_WRITE);
2817         /* Doesn't actually matter - We always assume sequential access */
2818         rq->sector = tape->first_frame_position;
2819         rq->nr_sectors = rq->current_nr_sectors = blocks;
2820
2821         idetape_switch_buffers(tape, new_stage);
2822         idetape_add_stage_tail(drive, new_stage);
2823         tape->pipeline_head++;
2824         calculate_speeds(drive);
2825
2826         /*
2827          *      Estimate whether the tape has stopped writing by checking
2828          *      if our write pipeline is currently empty. If we are not
2829          *      writing anymore, wait for the pipeline to be full enough
2830          *      (90%) before starting to service requests, so that we will
2831          *      be able to keep up with the higher speeds of the tape.
2832          */
2833         if (!idetape_pipeline_active(tape)) {
2834                 if (tape->nr_stages >= tape->max_stages * 9 / 10 ||
2835                     tape->nr_stages >= tape->max_stages - tape->uncontrolled_pipeline_head_speed * 3 * 1024 / tape->tape_block_size) {
2836                         tape->measure_insert_time = 1;
2837                         tape->insert_time = jiffies;
2838                         tape->insert_size = 0;
2839                         tape->insert_speed = 0;
2840                         idetape_insert_pipeline_into_queue(drive);
2841                 }
2842         }
2843         if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
2844                 /* Return a deferred error */
2845                 return -EIO;
2846         return blocks;
2847 }
2848
2849 /*
2850  *      idetape_wait_for_pipeline will wait until all pending pipeline
2851  *      requests are serviced. Typically called on device close.
2852  */
2853 static void idetape_wait_for_pipeline (ide_drive_t *drive)
2854 {
2855         idetape_tape_t *tape = drive->driver_data;
2856         unsigned long flags;
2857
2858         while (tape->next_stage || idetape_pipeline_active(tape)) {
2859                 idetape_insert_pipeline_into_queue(drive);
2860                 spin_lock_irqsave(&tape->spinlock, flags);
2861                 if (idetape_pipeline_active(tape))
2862                         idetape_wait_for_request(drive, tape->active_data_request);
2863                 spin_unlock_irqrestore(&tape->spinlock, flags);
2864         }
2865 }
2866
2867 static void idetape_empty_write_pipeline (ide_drive_t *drive)
2868 {
2869         idetape_tape_t *tape = drive->driver_data;
2870         int blocks, min;
2871         struct idetape_bh *bh;
2872
2873 #if IDETAPE_DEBUG_BUGS
2874         if (tape->chrdev_direction != idetape_direction_write) {
2875                 printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline, but we are not writing.\n");
2876                 return;
2877         }
2878         if (tape->merge_stage_size > tape->stage_size) {
2879                 printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
2880                 tape->merge_stage_size = tape->stage_size;
2881         }
2882 #endif /* IDETAPE_DEBUG_BUGS */
2883         if (tape->merge_stage_size) {
2884                 blocks = tape->merge_stage_size / tape->tape_block_size;
2885                 if (tape->merge_stage_size % tape->tape_block_size) {
2886                         unsigned int i;
2887
2888                         blocks++;
2889                         i = tape->tape_block_size - tape->merge_stage_size % tape->tape_block_size;
2890                         bh = tape->bh->b_reqnext;
2891                         while (bh) {
2892                                 atomic_set(&bh->b_count, 0);
2893                                 bh = bh->b_reqnext;
2894                         }
2895                         bh = tape->bh;
2896                         while (i) {
2897                                 if (bh == NULL) {
2898
2899                                         printk(KERN_INFO "ide-tape: bug, bh NULL\n");
2900                                         break;
2901                                 }
2902                                 min = min(i, (unsigned int)(bh->b_size - atomic_read(&bh->b_count)));
2903                                 memset(bh->b_data + atomic_read(&bh->b_count), 0, min);
2904                                 atomic_add(min, &bh->b_count);
2905                                 i -= min;
2906                                 bh = bh->b_reqnext;
2907                         }
2908                 }
2909                 (void) idetape_add_chrdev_write_request(drive, blocks);
2910                 tape->merge_stage_size = 0;
2911         }
2912         idetape_wait_for_pipeline(drive);
2913         if (tape->merge_stage != NULL) {
2914                 __idetape_kfree_stage(tape->merge_stage);
2915                 tape->merge_stage = NULL;
2916         }
2917         clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
2918         tape->chrdev_direction = idetape_direction_none;
2919
2920         /*
2921          *      On the next backup, perform the feedback loop again.
2922          *      (I don't want to keep sense information between backups,
2923          *       as some systems are constantly on, and the system load
2924          *       can be totally different on the next backup).
2925          */
2926         tape->max_stages = tape->min_pipeline;
2927 #if IDETAPE_DEBUG_BUGS
2928         if (tape->first_stage != NULL ||
2929             tape->next_stage != NULL ||
2930             tape->last_stage != NULL ||
2931             tape->nr_stages != 0) {
2932                 printk(KERN_ERR "ide-tape: ide-tape pipeline bug, "
2933                         "first_stage %p, next_stage %p, "
2934                         "last_stage %p, nr_stages %d\n",
2935                         tape->first_stage, tape->next_stage,
2936                         tape->last_stage, tape->nr_stages);
2937         }
2938 #endif /* IDETAPE_DEBUG_BUGS */
2939 }
2940
2941 static void idetape_restart_speed_control (ide_drive_t *drive)
2942 {
2943         idetape_tape_t *tape = drive->driver_data;
2944
2945         tape->restart_speed_control_req = 0;
2946         tape->pipeline_head = 0;
2947         tape->controlled_last_pipeline_head = tape->uncontrolled_last_pipeline_head = 0;
2948         tape->controlled_previous_pipeline_head = tape->uncontrolled_previous_pipeline_head = 0;
2949         tape->pipeline_head_speed = tape->controlled_pipeline_head_speed = 5000;
2950         tape->uncontrolled_pipeline_head_speed = 0;
2951         tape->controlled_pipeline_head_time = tape->uncontrolled_pipeline_head_time = jiffies;
2952         tape->controlled_previous_head_time = tape->uncontrolled_previous_head_time = jiffies;
2953 }
2954
2955 static int idetape_initiate_read (ide_drive_t *drive, int max_stages)
2956 {
2957         idetape_tape_t *tape = drive->driver_data;
2958         idetape_stage_t *new_stage;
2959         struct request rq;
2960         int bytes_read;
2961         int blocks = tape->capabilities.ctl;
2962
2963         /* Initialize read operation */
2964         if (tape->chrdev_direction != idetape_direction_read) {
2965                 if (tape->chrdev_direction == idetape_direction_write) {
2966                         idetape_empty_write_pipeline(drive);
2967                         idetape_flush_tape_buffers(drive);
2968                 }
2969 #if IDETAPE_DEBUG_BUGS
2970                 if (tape->merge_stage || tape->merge_stage_size) {
2971                         printk (KERN_ERR "ide-tape: merge_stage_size should be 0 now\n");
2972                         tape->merge_stage_size = 0;
2973                 }
2974 #endif /* IDETAPE_DEBUG_BUGS */
2975                 if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
2976                         return -ENOMEM;
2977                 tape->chrdev_direction = idetape_direction_read;
2978
2979                 /*
2980                  *      Issue a read 0 command to ensure that DSC handshake
2981                  *      is switched from completion mode to buffer available
2982                  *      mode.
2983                  *      No point in issuing this if DSC overlap isn't supported,
2984                  *      some drives (Seagate STT3401A) will return an error.
2985                  */
2986                 if (drive->dsc_overlap) {
2987                         bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh);
2988                         if (bytes_read < 0) {
2989                                 __idetape_kfree_stage(tape->merge_stage);
2990                                 tape->merge_stage = NULL;
2991                                 tape->chrdev_direction = idetape_direction_none;
2992                                 return bytes_read;
2993                         }
2994                 }
2995         }
2996         if (tape->restart_speed_control_req)
2997                 idetape_restart_speed_control(drive);
2998         idetape_init_rq(&rq, REQ_IDETAPE_READ);
2999         rq.sector = tape->first_frame_position;
3000         rq.nr_sectors = rq.current_nr_sectors = blocks;
3001         if (!test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags) &&
3002             tape->nr_stages < max_stages) {
3003                 new_stage = idetape_kmalloc_stage(tape);
3004                 while (new_stage != NULL) {
3005                         new_stage->rq = rq;
3006                         idetape_add_stage_tail(drive, new_stage);
3007                         if (tape->nr_stages >= max_stages)
3008                                 break;
3009                         new_stage = idetape_kmalloc_stage(tape);
3010                 }
3011         }
3012         if (!idetape_pipeline_active(tape)) {
3013                 if (tape->nr_pending_stages >= 3 * max_stages / 4) {
3014                         tape->measure_insert_time = 1;
3015                         tape->insert_time = jiffies;
3016                         tape->insert_size = 0;
3017                         tape->insert_speed = 0;
3018                         idetape_insert_pipeline_into_queue(drive);
3019                 }
3020         }
3021         return 0;
3022 }
3023
3024 /*
3025  *      idetape_add_chrdev_read_request is called from idetape_chrdev_read
3026  *      to service a character device read request and add read-ahead
3027  *      requests to our pipeline.
3028  */
3029 static int idetape_add_chrdev_read_request (ide_drive_t *drive,int blocks)
3030 {
3031         idetape_tape_t *tape = drive->driver_data;
3032         unsigned long flags;
3033         struct request *rq_ptr;
3034         int bytes_read;
3035
3036 #if IDETAPE_DEBUG_LOG
3037         if (tape->debug_level >= 4)
3038                 printk(KERN_INFO "ide-tape: Reached idetape_add_chrdev_read_request, %d blocks\n", blocks);
3039 #endif /* IDETAPE_DEBUG_LOG */
3040
3041         /*
3042          * If we are at a filemark, return a read length of 0
3043          */
3044         if (test_bit(IDETAPE_FILEMARK, &tape->flags))
3045                 return 0;
3046
3047         /*
3048          * Wait for the next block to be available at the head
3049          * of the pipeline
3050          */
3051         idetape_initiate_read(drive, tape->max_stages);
3052         if (tape->first_stage == NULL) {
3053                 if (test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
3054                         return 0;
3055                 return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks, tape->merge_stage->bh);
3056         }
3057         idetape_wait_first_stage(drive);
3058         rq_ptr = &tape->first_stage->rq;
3059         bytes_read = tape->tape_block_size * (rq_ptr->nr_sectors - rq_ptr->current_nr_sectors);
3060         rq_ptr->nr_sectors = rq_ptr->current_nr_sectors = 0;
3061
3062
3063         if (rq_ptr->errors == IDETAPE_ERROR_EOD)
3064                 return 0;
3065         else {
3066                 idetape_switch_buffers(tape, tape->first_stage);
3067                 if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
3068                         set_bit(IDETAPE_FILEMARK, &tape->flags);
3069                 spin_lock_irqsave(&tape->spinlock, flags);
3070                 idetape_remove_stage_head(drive);
3071                 spin_unlock_irqrestore(&tape->spinlock, flags);
3072                 tape->pipeline_head++;
3073                 calculate_speeds(drive);
3074         }
3075 #if IDETAPE_DEBUG_BUGS
3076         if (bytes_read > blocks * tape->tape_block_size) {
3077                 printk(KERN_ERR "ide-tape: bug: trying to return more bytes than requested\n");
3078                 bytes_read = blocks * tape->tape_block_size;
3079         }
3080 #endif /* IDETAPE_DEBUG_BUGS */
3081         return (bytes_read);
3082 }
3083
3084 static void idetape_pad_zeros (ide_drive_t *drive, int bcount)
3085 {
3086         idetape_tape_t *tape = drive->driver_data;
3087         struct idetape_bh *bh;
3088         int blocks;
3089
3090         while (bcount) {
3091                 unsigned int count;
3092
3093                 bh = tape->merge_stage->bh;
3094                 count = min(tape->stage_size, bcount);
3095                 bcount -= count;
3096                 blocks = count / tape->tape_block_size;
3097                 while (count) {
3098                         atomic_set(&bh->b_count, min(count, (unsigned int)bh->b_size));
3099                         memset(bh->b_data, 0, atomic_read(&bh->b_count));
3100                         count -= atomic_read(&bh->b_count);
3101                         bh = bh->b_reqnext;
3102                 }
3103                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
3104         }
3105 }
3106
3107 static int idetape_pipeline_size (ide_drive_t *drive)
3108 {
3109         idetape_tape_t *tape = drive->driver_data;
3110         idetape_stage_t *stage;
3111         struct request *rq;
3112         int size = 0;
3113
3114         idetape_wait_for_pipeline(drive);
3115         stage = tape->first_stage;
3116         while (stage != NULL) {
3117                 rq = &stage->rq;
3118                 size += tape->tape_block_size * (rq->nr_sectors-rq->current_nr_sectors);
3119                 if (rq->errors == IDETAPE_ERROR_FILEMARK)
3120                         size += tape->tape_block_size;
3121                 stage = stage->next;
3122         }
3123         size += tape->merge_stage_size;
3124         return size;
3125 }
3126
3127 /*
3128  *      Rewinds the tape to the Beginning Of the current Partition (BOP).
3129  *
3130  *      We currently support only one partition.
3131  */
3132 static int idetape_rewind_tape (ide_drive_t *drive)
3133 {
3134         int retval;
3135         idetape_pc_t pc;
3136 #if IDETAPE_DEBUG_LOG
3137         idetape_tape_t *tape = drive->driver_data;
3138         if (tape->debug_level >= 2)
3139                 printk(KERN_INFO "ide-tape: Reached idetape_rewind_tape\n");
3140 #endif /* IDETAPE_DEBUG_LOG */
3141
3142         idetape_create_rewind_cmd(drive, &pc);
3143         retval = idetape_queue_pc_tail(drive, &pc);
3144         if (retval)
3145                 return retval;
3146
3147         idetape_create_read_position_cmd(&pc);
3148         retval = idetape_queue_pc_tail(drive, &pc);
3149         if (retval)
3150                 return retval;
3151         return 0;
3152 }
3153
3154 /*
3155  *      Our special ide-tape ioctl's.
3156  *
3157  *      Currently there aren't any ioctl's.
3158  *      mtio.h compatible commands should be issued to the character device
3159  *      interface.
3160  */
3161 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, unsigned long arg)
3162 {
3163         idetape_tape_t *tape = drive->driver_data;
3164         idetape_config_t config;
3165         void __user *argp = (void __user *)arg;
3166
3167 #if IDETAPE_DEBUG_LOG
3168         if (tape->debug_level >= 4)
3169                 printk(KERN_INFO "ide-tape: Reached idetape_blkdev_ioctl\n");
3170 #endif /* IDETAPE_DEBUG_LOG */
3171         switch (cmd) {
3172                 case 0x0340:
3173                         if (copy_from_user(&config, argp, sizeof (idetape_config_t)))
3174                                 return -EFAULT;
3175                         tape->best_dsc_rw_frequency = config.dsc_rw_frequency;
3176                         tape->max_stages = config.nr_stages;
3177                         break;
3178                 case 0x0350:
3179                         config.dsc_rw_frequency = (int) tape->best_dsc_rw_frequency;
3180                         config.nr_stages = tape->max_stages;
3181                         if (copy_to_user(argp, &config, sizeof (idetape_config_t)))
3182                                 return -EFAULT;
3183                         break;
3184                 default:
3185                         return -EIO;
3186         }
3187         return 0;
3188 }
3189
3190 /*
3191  *      idetape_space_over_filemarks is now a bit more complicated than just
3192  *      passing the command to the tape since we may have crossed some
3193  *      filemarks during our pipelined read-ahead mode.
3194  *
3195  *      As a minor side effect, the pipeline enables us to support MTFSFM when
3196  *      the filemark is in our internal pipeline even if the tape doesn't
3197  *      support spacing over filemarks in the reverse direction.
3198  */
3199 static int idetape_space_over_filemarks (ide_drive_t *drive,short mt_op,int mt_count)
3200 {
3201         idetape_tape_t *tape = drive->driver_data;
3202         idetape_pc_t pc;
3203         unsigned long flags;
3204         int retval,count=0;
3205
3206         if (mt_count == 0)
3207                 return 0;
3208         if (MTBSF == mt_op || MTBSFM == mt_op) {
3209                 if (!tape->capabilities.sprev)
3210                         return -EIO;
3211                 mt_count = - mt_count;
3212         }
3213
3214         if (tape->chrdev_direction == idetape_direction_read) {
3215                 /*
3216                  *      We have a read-ahead buffer. Scan it for crossed
3217                  *      filemarks.
3218                  */
3219                 tape->merge_stage_size = 0;
3220                 if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
3221                         ++count;
3222                 while (tape->first_stage != NULL) {
3223                         if (count == mt_count) {
3224                                 if (mt_op == MTFSFM)
3225                                         set_bit(IDETAPE_FILEMARK, &tape->flags);
3226                                 return 0;
3227                         }
3228                         spin_lock_irqsave(&tape->spinlock, flags);
3229                         if (tape->first_stage == tape->active_stage) {
3230                                 /*
3231                                  *      We have reached the active stage in the read pipeline.
3232                                  *      There is no point in allowing the drive to continue
3233                                  *      reading any farther, so we stop the pipeline.
3234                                  *
3235                                  *      This section should be moved to a separate subroutine,
3236                                  *      because a similar function is performed in
3237                                  *      __idetape_discard_read_pipeline(), for example.
3238                                  */
3239                                 tape->next_stage = NULL;
3240                                 spin_unlock_irqrestore(&tape->spinlock, flags);
3241                                 idetape_wait_first_stage(drive);
3242                                 tape->next_stage = tape->first_stage->next;
3243                         } else
3244                                 spin_unlock_irqrestore(&tape->spinlock, flags);
3245                         if (tape->first_stage->rq.errors == IDETAPE_ERROR_FILEMARK)
3246                                 ++count;
3247                         idetape_remove_stage_head(drive);
3248                 }
3249                 idetape_discard_read_pipeline(drive, 0);
3250         }
3251
3252         /*
3253          *      The filemark was not found in our internal pipeline.
3254          *      Now we can issue the space command.
3255          */
3256         switch (mt_op) {
3257                 case MTFSF:
3258                 case MTBSF:
3259                         idetape_create_space_cmd(&pc,mt_count-count,IDETAPE_SPACE_OVER_FILEMARK);
3260                         return (idetape_queue_pc_tail(drive, &pc));
3261                 case MTFSFM:
3262                 case MTBSFM:
3263                         if (!tape->capabilities.sprev)
3264                                 return (-EIO);
3265                         retval = idetape_space_over_filemarks(drive, MTFSF, mt_count-count);
3266                         if (retval) return (retval);
3267                         count = (MTBSFM == mt_op ? 1 : -1);
3268                         return (idetape_space_over_filemarks(drive, MTFSF, count));
3269                 default:
3270                         printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",mt_op);
3271                         return (-EIO);
3272         }
3273 }
3274
3275
3276 /*
3277  *      Our character device read / write functions.
3278  *
3279  *      The tape is optimized to maximize throughput when it is transferring
3280  *      an integral number of the "continuous transfer limit", which is
3281  *      a parameter of the specific tape (26 KB on my particular tape).
3282  *      (32 kB for Onstream)
3283  *
3284  *      As of version 1.3 of the driver, the character device provides an
3285  *      abstract continuous view of the media - any mix of block sizes (even 1
3286  *      byte) on the same backup/restore procedure is supported. The driver
3287  *      will internally convert the requests to the recommended transfer unit,
3288  *      so that an unmatch between the user's block size to the recommended
3289  *      size will only result in a (slightly) increased driver overhead, but
3290  *      will no longer hit performance.
3291  *      This is not applicable to Onstream.
3292  */
3293 static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
3294                                     size_t count, loff_t *ppos)
3295 {
3296         struct ide_tape_obj *tape = ide_tape_f(file);
3297         ide_drive_t *drive = tape->drive;
3298         ssize_t bytes_read,temp, actually_read = 0, rc;
3299         ssize_t ret = 0;
3300
3301 #if IDETAPE_DEBUG_LOG
3302         if (tape->debug_level >= 3)
3303                 printk(KERN_INFO "ide-tape: Reached idetape_chrdev_read, count %Zd\n", count);
3304 #endif /* IDETAPE_DEBUG_LOG */
3305
3306         if (tape->chrdev_direction != idetape_direction_read) {
3307                 if (test_bit(IDETAPE_DETECT_BS, &tape->flags))
3308                         if (count > tape->tape_block_size &&
3309                             (count % tape->tape_block_size) == 0)
3310                                 tape->user_bs_factor = count / tape->tape_block_size;
3311         }
3312         if ((rc = idetape_initiate_read(drive, tape->max_stages)) < 0)
3313                 return rc;
3314         if (count == 0)
3315                 return (0);
3316         if (tape->merge_stage_size) {
3317                 actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count);
3318                 if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read))
3319                         ret = -EFAULT;
3320                 buf += actually_read;
3321                 tape->merge_stage_size -= actually_read;
3322                 count -= actually_read;
3323         }
3324         while (count >= tape->stage_size) {
3325                 bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl);
3326                 if (bytes_read <= 0)
3327                         goto finish;
3328                 if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read))
3329                         ret = -EFAULT;
3330                 buf += bytes_read;
3331                 count -= bytes_read;
3332                 actually_read += bytes_read;
3333         }
3334         if (count) {
3335                 bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl);
3336                 if (bytes_read <= 0)
3337                         goto finish;
3338                 temp = min((unsigned long)count, (unsigned long)bytes_read);
3339                 if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp))
3340                         ret = -EFAULT;
3341                 actually_read += temp;
3342                 tape->merge_stage_size = bytes_read-temp;
3343         }
3344 finish:
3345         if (!actually_read && test_bit(IDETAPE_FILEMARK, &tape->flags)) {
3346 #if IDETAPE_DEBUG_LOG
3347                 if (tape->debug_level >= 2)
3348                         printk(KERN_INFO "ide-tape: %s: spacing over filemark\n", tape->name);
3349 #endif
3350                 idetape_space_over_filemarks(drive, MTFSF, 1);
3351                 return 0;
3352         }
3353
3354         return (ret) ? ret : actually_read;
3355 }
3356
3357 static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
3358                                      size_t count, loff_t *ppos)
3359 {
3360         struct ide_tape_obj *tape = ide_tape_f(file);
3361         ide_drive_t *drive = tape->drive;
3362         ssize_t actually_written = 0;
3363         ssize_t ret = 0;
3364
3365         /* The drive is write protected. */
3366         if (tape->write_prot)
3367                 return -EACCES;
3368
3369 #if IDETAPE_DEBUG_LOG
3370         if (tape->debug_level >= 3)
3371                 printk(KERN_INFO "ide-tape: Reached idetape_chrdev_write, "
3372                         "count %Zd\n", count);
3373 #endif /* IDETAPE_DEBUG_LOG */
3374
3375         /* Initialize write operation */
3376         if (tape->chrdev_direction != idetape_direction_write) {
3377                 if (tape->chrdev_direction == idetape_direction_read)
3378                         idetape_discard_read_pipeline(drive, 1);
3379 #if IDETAPE_DEBUG_BUGS
3380                 if (tape->merge_stage || tape->merge_stage_size) {
3381                         printk(KERN_ERR "ide-tape: merge_stage_size "
3382                                 "should be 0 now\n");
3383                         tape->merge_stage_size = 0;
3384                 }
3385 #endif /* IDETAPE_DEBUG_BUGS */
3386                 if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
3387                         return -ENOMEM;
3388                 tape->chrdev_direction = idetape_direction_write;
3389                 idetape_init_merge_stage(tape);
3390
3391                 /*
3392                  *      Issue a write 0 command to ensure that DSC handshake
3393                  *      is switched from completion mode to buffer available
3394                  *      mode.
3395                  *      No point in issuing this if DSC overlap isn't supported,
3396                  *      some drives (Seagate STT3401A) will return an error.
3397                  */
3398                 if (drive->dsc_overlap) {
3399                         ssize_t retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
3400                         if (retval < 0) {
3401                                 __idetape_kfree_stage(tape->merge_stage);
3402                                 tape->merge_stage = NULL;
3403                                 tape->chrdev_direction = idetape_direction_none;
3404                                 return retval;
3405                         }
3406                 }
3407         }
3408         if (count == 0)
3409                 return (0);
3410         if (tape->restart_speed_control_req)
3411                 idetape_restart_speed_control(drive);
3412         if (tape->merge_stage_size) {
3413 #if IDETAPE_DEBUG_BUGS
3414                 if (tape->merge_stage_size >= tape->stage_size) {
3415                         printk(KERN_ERR "ide-tape: bug: merge buffer too big\n");
3416                         tape->merge_stage_size = 0;
3417                 }
3418 #endif /* IDETAPE_DEBUG_BUGS */
3419                 actually_written = min((unsigned int)(tape->stage_size - tape->merge_stage_size), (unsigned int)count);
3420                 if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written))
3421                                 ret = -EFAULT;
3422                 buf += actually_written;
3423                 tape->merge_stage_size += actually_written;
3424                 count -= actually_written;
3425
3426                 if (tape->merge_stage_size == tape->stage_size) {
3427                         ssize_t retval;
3428                         tape->merge_stage_size = 0;
3429                         retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
3430                         if (retval <= 0)
3431                                 return (retval);
3432                 }
3433         }
3434         while (count >= tape->stage_size) {
3435                 ssize_t retval;
3436                 if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size))
3437                         ret = -EFAULT;
3438                 buf += tape->stage_size;
3439                 count -= tape->stage_size;
3440                 retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
3441                 actually_written += tape->stage_size;
3442                 if (retval <= 0)
3443                         return (retval);
3444         }
3445         if (count) {
3446                 actually_written += count;
3447                 if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count))
3448                         ret = -EFAULT;
3449                 tape->merge_stage_size += count;
3450         }
3451         return (ret) ? ret : actually_written;
3452 }
3453
3454 static int idetape_write_filemark (ide_drive_t *drive)
3455 {
3456         idetape_pc_t pc;
3457
3458         /* Write a filemark */
3459         idetape_create_write_filemark_cmd(drive, &pc, 1);
3460         if (idetape_queue_pc_tail(drive, &pc)) {
3461                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
3462                 return -EIO;
3463         }
3464         return 0;
3465 }
3466
3467 /*
3468  *      idetape_mtioctop is called from idetape_chrdev_ioctl when
3469  *      the general mtio MTIOCTOP ioctl is requested.
3470  *
3471  *      We currently support the following mtio.h operations:
3472  *
3473  *      MTFSF   -       Space over mt_count filemarks in the positive direction.
3474  *                      The tape is positioned after the last spaced filemark.
3475  *
3476  *      MTFSFM  -       Same as MTFSF, but the tape is positioned before the
3477  *                      last filemark.
3478  *
3479  *      MTBSF   -       Steps background over mt_count filemarks, tape is
3480  *                      positioned before the last filemark.
3481  *
3482  *      MTBSFM  -       Like MTBSF, only tape is positioned after the last filemark.
3483  *
3484  *      Note:
3485  *
3486  *              MTBSF and MTBSFM are not supported when the tape doesn't
3487  *              support spacing over filemarks in the reverse direction.
3488  *              In this case, MTFSFM is also usually not supported (it is
3489  *              supported in the rare case in which we crossed the filemark
3490  *              during our read-ahead pipelined operation mode).
3491  *
3492  *      MTWEOF  -       Writes mt_count filemarks. Tape is positioned after
3493  *                      the last written filemark.
3494  *
3495  *      MTREW   -       Rewinds tape.
3496  *
3497  *      MTLOAD  -       Loads the tape.
3498  *
3499  *      MTOFFL  -       Puts the tape drive "Offline": Rewinds the tape and
3500  *      MTUNLOAD        prevents further access until the media is replaced.
3501  *
3502  *      MTNOP   -       Flushes tape buffers.
3503  *
3504  *      MTRETEN -       Retension media. This typically consists of one end
3505  *                      to end pass on the media.
3506  *
3507  *      MTEOM   -       Moves to the end of recorded data.
3508  *
3509  *      MTERASE -       Erases tape.
3510  *
3511  *      MTSETBLK -      Sets the user block size to mt_count bytes. If
3512  *                      mt_count is 0, we will attempt to autodetect
3513  *                      the block size.
3514  *
3515  *      MTSEEK  -       Positions the tape in a specific block number, where
3516  *                      each block is assumed to contain which user_block_size
3517  *                      bytes.
3518  *
3519  *      MTSETPART -     Switches to another tape partition.
3520  *
3521  *      MTLOCK -        Locks the tape door.
3522  *
3523  *      MTUNLOCK -      Unlocks the tape door.
3524  *
3525  *      The following commands are currently not supported:
3526  *
3527  *      MTFSS, MTBSS, MTWSM, MTSETDENSITY,
3528  *      MTSETDRVBUFFER, MT_ST_BOOLEANS, MT_ST_WRITE_THRESHOLD.
3529  */
3530 static int idetape_mtioctop (ide_drive_t *drive,short mt_op,int mt_count)
3531 {
3532         idetape_tape_t *tape = drive->driver_data;
3533         idetape_pc_t pc;
3534         int i,retval;
3535
3536 #if IDETAPE_DEBUG_LOG
3537         if (tape->debug_level >= 1)
3538                 printk(KERN_INFO "ide-tape: Handling MTIOCTOP ioctl: "
3539                         "mt_op=%d, mt_count=%d\n", mt_op, mt_count);
3540 #endif /* IDETAPE_DEBUG_LOG */
3541         /*
3542          *      Commands which need our pipelined read-ahead stages.
3543          */
3544         switch (mt_op) {
3545                 case MTFSF:
3546                 case MTFSFM:
3547                 case MTBSF:
3548                 case MTBSFM:
3549                         if (!mt_count)
3550                                 return (0);
3551                         return (idetape_space_over_filemarks(drive,mt_op,mt_count));
3552                 default:
3553                         break;
3554         }
3555         switch (mt_op) {
3556                 case MTWEOF:
3557                         if (tape->write_prot)
3558                                 return -EACCES;
3559                         idetape_discard_read_pipeline(drive, 1);
3560                         for (i = 0; i < mt_count; i++) {
3561                                 retval = idetape_write_filemark(drive);
3562                                 if (retval)
3563                                         return retval;
3564                         }
3565                         return (0);
3566                 case MTREW:
3567                         idetape_discard_read_pipeline(drive, 0);
3568                         if (idetape_rewind_tape(drive))
3569                                 return -EIO;
3570                         return 0;
3571                 case MTLOAD:
3572                         idetape_discard_read_pipeline(drive, 0);
3573                         idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
3574                         return (idetape_queue_pc_tail(drive, &pc));
3575                 case MTUNLOAD:
3576                 case MTOFFL:
3577                         /*
3578                          * If door is locked, attempt to unlock before
3579                          * attempting to eject.
3580                          */
3581                         if (tape->door_locked) {
3582                                 if (idetape_create_prevent_cmd(drive, &pc, 0))
3583                                         if (!idetape_queue_pc_tail(drive, &pc))
3584                                                 tape->door_locked = DOOR_UNLOCKED;
3585                         }
3586                         idetape_discard_read_pipeline(drive, 0);
3587                         idetape_create_load_unload_cmd(drive, &pc,!IDETAPE_LU_LOAD_MASK);
3588                         retval = idetape_queue_pc_tail(drive, &pc);
3589                         if (!retval)
3590                                 clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
3591                         return retval;
3592                 case MTNOP:
3593                         idetape_discard_read_pipeline(drive, 0);
3594                         return (idetape_flush_tape_buffers(drive));
3595                 case MTRETEN:
3596                         idetape_discard_read_pipeline(drive, 0);
3597                         idetape_create_load_unload_cmd(drive, &pc,IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
3598                         return (idetape_queue_pc_tail(drive, &pc));
3599                 case MTEOM:
3600                         idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
3601                         return (idetape_queue_pc_tail(drive, &pc));
3602                 case MTERASE:
3603                         (void) idetape_rewind_tape(drive);
3604                         idetape_create_erase_cmd(&pc);
3605                         return (idetape_queue_pc_tail(drive, &pc));
3606                 case MTSETBLK:
3607                         if (mt_count) {
3608                                 if (mt_count < tape->tape_block_size || mt_count % tape->tape_block_size)
3609                                         return -EIO;
3610                                 tape->user_bs_factor = mt_count / tape->tape_block_size;
3611                                 clear_bit(IDETAPE_DETECT_BS, &tape->flags);
3612                         } else
3613                                 set_bit(IDETAPE_DETECT_BS, &tape->flags);
3614                         return 0;
3615                 case MTSEEK:
3616                         idetape_discard_read_pipeline(drive, 0);
3617                         return idetape_position_tape(drive, mt_count * tape->user_bs_factor, tape->partition, 0);
3618                 case MTSETPART:
3619                         idetape_discard_read_pipeline(drive, 0);
3620                         return (idetape_position_tape(drive, 0, mt_count, 0));
3621                 case MTFSR:
3622                 case MTBSR:
3623                 case MTLOCK:
3624                         if (!idetape_create_prevent_cmd(drive, &pc, 1))
3625                                 return 0;
3626                         retval = idetape_queue_pc_tail(drive, &pc);
3627                         if (retval) return retval;
3628                         tape->door_locked = DOOR_EXPLICITLY_LOCKED;
3629                         return 0;
3630                 case MTUNLOCK:
3631                         if (!idetape_create_prevent_cmd(drive, &pc, 0))
3632                                 return 0;
3633                         retval = idetape_queue_pc_tail(drive, &pc);
3634                         if (retval) return retval;
3635                         tape->door_locked = DOOR_UNLOCKED;
3636                         return 0;
3637                 default:
3638                         printk(KERN_ERR "ide-tape: MTIO operation %d not "
3639                                 "supported\n", mt_op);
3640                         return (-EIO);
3641         }
3642 }
3643
3644 /*
3645  *      Our character device ioctls.
3646  *
3647  *      General mtio.h magnetic io commands are supported here, and not in
3648  *      the corresponding block interface.
3649  *
3650  *      The following ioctls are supported:
3651  *
3652  *      MTIOCTOP -      Refer to idetape_mtioctop for detailed description.
3653  *
3654  *      MTIOCGET -      The mt_dsreg field in the returned mtget structure
3655  *                      will be set to (user block size in bytes <<
3656  *                      MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK.
3657  *
3658  *                      The mt_blkno is set to the current user block number.
3659  *                      The other mtget fields are not supported.
3660  *
3661  *      MTIOCPOS -      The current tape "block position" is returned. We
3662  *                      assume that each block contains user_block_size
3663  *                      bytes.
3664  *
3665  *      Our own ide-tape ioctls are supported on both interfaces.
3666  */
3667 static int idetape_chrdev_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
3668 {
3669         struct ide_tape_obj *tape = ide_tape_f(file);
3670         ide_drive_t *drive = tape->drive;
3671         struct mtop mtop;
3672         struct mtget mtget;
3673         struct mtpos mtpos;
3674         int block_offset = 0, position = tape->first_frame_position;
3675         void __user *argp = (void __user *)arg;
3676
3677 #if IDETAPE_DEBUG_LOG
3678         if (tape->debug_level >= 3)
3679                 printk(KERN_INFO "ide-tape: Reached idetape_chrdev_ioctl, "
3680                         "cmd=%u\n", cmd);
3681 #endif /* IDETAPE_DEBUG_LOG */
3682
3683         tape->restart_speed_control_req = 1;
3684         if (tape->chrdev_direction == idetape_direction_write) {
3685                 idetape_empty_write_pipeline(drive);
3686                 idetape_flush_tape_buffers(drive);
3687         }
3688         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
3689                 block_offset = idetape_pipeline_size(drive) / (tape->tape_block_size * tape->user_bs_factor);
3690                 if ((position = idetape_read_position(drive)) < 0)
3691                         return -EIO;
3692         }
3693         switch (cmd) {
3694                 case MTIOCTOP:
3695                         if (copy_from_user(&mtop, argp, sizeof (struct mtop)))
3696                                 return -EFAULT;
3697                         return (idetape_mtioctop(drive,mtop.mt_op,mtop.mt_count));
3698                 case MTIOCGET:
3699                         memset(&mtget, 0, sizeof (struct mtget));
3700                         mtget.mt_type = MT_ISSCSI2;
3701                         mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
3702                         mtget.mt_dsreg = ((tape->tape_block_size * tape->user_bs_factor) << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
3703                         if (tape->drv_write_prot) {
3704                                 mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
3705                         }
3706                         if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
3707                                 return -EFAULT;
3708                         return 0;
3709                 case MTIOCPOS:
3710                         mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
3711                         if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
3712                                 return -EFAULT;
3713                         return 0;
3714                 default:
3715                         if (tape->chrdev_direction == idetape_direction_read)
3716                                 idetape_discard_read_pipeline(drive, 1);
3717                         return idetape_blkdev_ioctl(drive, cmd, arg);
3718         }
3719 }
3720
3721 static void idetape_get_blocksize_from_block_descriptor(ide_drive_t *drive);
3722
3723 /*
3724  *      Our character device open function.
3725  */
3726 static int idetape_chrdev_open (struct inode *inode, struct file *filp)
3727 {
3728         unsigned int minor = iminor(inode), i = minor & ~0xc0;
3729         ide_drive_t *drive;
3730         idetape_tape_t *tape;
3731         idetape_pc_t pc;
3732         int retval;
3733
3734         /*
3735          * We really want to do nonseekable_open(inode, filp); here, but some
3736          * versions of tar incorrectly call lseek on tapes and bail out if that
3737          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
3738          */
3739         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
3740
3741 #if IDETAPE_DEBUG_LOG
3742         printk(KERN_INFO "ide-tape: Reached idetape_chrdev_open\n");
3743 #endif /* IDETAPE_DEBUG_LOG */
3744
3745         if (i >= MAX_HWIFS * MAX_DRIVES)
3746                 return -ENXIO;
3747
3748         if (!(tape = ide_tape_chrdev_get(i)))
3749                 return -ENXIO;
3750
3751         drive = tape->drive;
3752
3753         filp->private_data = tape;
3754
3755         if (test_and_set_bit(IDETAPE_BUSY, &tape->flags)) {
3756                 retval = -EBUSY;
3757                 goto out_put_tape;
3758         }
3759
3760         retval = idetape_wait_ready(drive, 60 * HZ);
3761         if (retval) {
3762                 clear_bit(IDETAPE_BUSY, &tape->flags);
3763                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
3764                 goto out_put_tape;
3765         }
3766
3767         idetape_read_position(drive);
3768         if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags))
3769                 (void)idetape_rewind_tape(drive);
3770
3771         if (tape->chrdev_direction != idetape_direction_read)
3772                 clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
3773
3774         /* Read block size and write protect status from drive. */
3775         idetape_get_blocksize_from_block_descriptor(drive);
3776
3777         /* Set write protect flag if device is opened as read-only. */
3778         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
3779                 tape->write_prot = 1;
3780         else
3781                 tape->write_prot = tape->drv_write_prot;
3782
3783         /* Make sure drive isn't write protected if user wants to write. */
3784         if (tape->write_prot) {
3785                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
3786                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
3787                         clear_bit(IDETAPE_BUSY, &tape->flags);
3788                         retval = -EROFS;
3789                         goto out_put_tape;
3790                 }
3791         }
3792
3793         /*
3794          * Lock the tape drive door so user can't eject.
3795          */
3796         if (tape->chrdev_direction == idetape_direction_none) {
3797                 if (idetape_create_prevent_cmd(drive, &pc, 1)) {
3798                         if (!idetape_queue_pc_tail(drive, &pc)) {
3799                                 if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
3800                                         tape->door_locked = DOOR_LOCKED;
3801                         }
3802                 }
3803         }
3804         idetape_restart_speed_control(drive);
3805         tape->restart_speed_control_req = 0;
3806         return 0;
3807
3808 out_put_tape:
3809         ide_tape_put(tape);
3810         return retval;
3811 }
3812
3813 static void idetape_write_release (ide_drive_t *drive, unsigned int minor)
3814 {
3815         idetape_tape_t *tape = drive->driver_data;
3816
3817         idetape_empty_write_pipeline(drive);
3818         tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0);
3819         if (tape->merge_stage != NULL) {
3820                 idetape_pad_zeros(drive, tape->tape_block_size * (tape->user_bs_factor - 1));
3821                 __idetape_kfree_stage(tape->merge_stage);
3822                 tape->merge_stage = NULL;
3823         }
3824         idetape_write_filemark(drive);
3825         idetape_flush_tape_buffers(drive);
3826         idetape_flush_tape_buffers(drive);
3827 }
3828
3829 /*
3830  *      Our character device release function.
3831  */
3832 static int idetape_chrdev_release (struct inode *inode, struct file *filp)
3833 {
3834         struct ide_tape_obj *tape = ide_tape_f(filp);
3835         ide_drive_t *drive = tape->drive;
3836         idetape_pc_t pc;
3837         unsigned int minor = iminor(inode);
3838
3839         lock_kernel();
3840         tape = drive->driver_data;
3841 #if IDETAPE_DEBUG_LOG
3842         if (tape->debug_level >= 3)
3843                 printk(KERN_INFO "ide-tape: Reached idetape_chrdev_release\n");
3844 #endif /* IDETAPE_DEBUG_LOG */
3845
3846         if (tape->chrdev_direction == idetape_direction_write)
3847                 idetape_write_release(drive, minor);
3848         if (tape->chrdev_direction == idetape_direction_read) {
3849                 if (minor < 128)
3850                         idetape_discard_read_pipeline(drive, 1);
3851                 else
3852                         idetape_wait_for_pipeline(drive);
3853         }
3854         if (tape->cache_stage != NULL) {
3855                 __idetape_kfree_stage(tape->cache_stage);
3856                 tape->cache_stage = NULL;
3857         }
3858         if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags))
3859                 (void) idetape_rewind_tape(drive);
3860         if (tape->chrdev_direction == idetape_direction_none) {
3861                 if (tape->door_locked == DOOR_LOCKED) {
3862                         if (idetape_create_prevent_cmd(drive, &pc, 0)) {
3863                                 if (!idetape_queue_pc_tail(drive, &pc))
3864                                         tape->door_locked = DOOR_UNLOCKED;
3865                         }
3866                 }
3867         }
3868         clear_bit(IDETAPE_BUSY, &tape->flags);
3869         ide_tape_put(tape);
3870         unlock_kernel();
3871         return 0;
3872 }
3873
3874 /*
3875  *      idetape_identify_device is called to check the contents of the
3876  *      ATAPI IDENTIFY command results. We return:
3877  *
3878  *      1       If the tape can be supported by us, based on the information
3879  *              we have so far.
3880  *
3881  *      0       If this tape driver is not currently supported by us.
3882  */
3883 static int idetape_identify_device (ide_drive_t *drive)
3884 {
3885         struct idetape_id_gcw gcw;
3886         struct hd_driveid *id = drive->id;
3887
3888         if (drive->id_read == 0)
3889                 return 1;
3890
3891         *((unsigned short *) &gcw) = id->config;
3892
3893 #if IDETAPE_DEBUG_INFO
3894         printk(KERN_INFO "ide-tape: Dumping ATAPI Identify Device tape parameters\n");
3895         printk(KERN_INFO "ide-tape: Protocol Type: ");
3896         switch (gcw.protocol) {
3897                 case 0: case 1: printk("ATA\n");break;
3898                 case 2: printk("ATAPI\n");break;
3899                 case 3: printk("Reserved (Unknown to ide-tape)\n");break;
3900         }
3901         printk(KERN_INFO "ide-tape: Device Type: %x - ",gcw.device_type);
3902         switch (gcw.device_type) {
3903                 case 0: printk("Direct-access Device\n");break;
3904                 case 1: printk("Streaming Tape Device\n");break;
3905                 case 2: case 3: case 4: printk("Reserved\n");break;
3906                 case 5: printk("CD-ROM Device\n");break;
3907                 case 6: printk("Reserved\n");
3908                 case 7: printk("Optical memory Device\n");break;
3909                 case 0x1f: printk("Unknown or no Device type\n");break;
3910                 default: printk("Reserved\n");
3911         }
3912         printk(KERN_INFO "ide-tape: Removable: %s",gcw.removable ? "Yes\n":"No\n");
3913         printk(KERN_INFO "ide-tape: Command Packet DRQ Type: ");
3914         switch (gcw.drq_type) {
3915                 case 0: printk("Microprocessor DRQ\n");break;
3916                 case 1: printk("Interrupt DRQ\n");break;
3917                 case 2: printk("Accelerated DRQ\n");break;
3918                 case 3: printk("Reserved\n");break;
3919         }
3920         printk(KERN_INFO "ide-tape: Command Packet Size: ");
3921         switch (gcw.packet_size) {
3922                 case 0: printk("12 bytes\n");break;
3923                 case 1: printk("16 bytes\n");break;
3924                 default: printk("Reserved\n");break;
3925         }
3926 #endif /* IDETAPE_DEBUG_INFO */
3927
3928         /* Check that we can support this device */
3929
3930         if (gcw.protocol !=2 )
3931                 printk(KERN_ERR "ide-tape: Protocol is not ATAPI\n");
3932         else if (gcw.device_type != 1)
3933                 printk(KERN_ERR "ide-tape: Device type is not set to tape\n");
3934         else if (!gcw.removable)
3935                 printk(KERN_ERR "ide-tape: The removable flag is not set\n");
3936         else if (gcw.packet_size != 0) {
3937                 printk(KERN_ERR "ide-tape: Packet size is not 12 bytes long\n");
3938                 if (gcw.packet_size == 1)
3939                         printk(KERN_ERR "ide-tape: Sorry, padding to 16 bytes is still not supported\n");
3940         } else
3941                 return 1;
3942         return 0;
3943 }
3944
3945 /*
3946  * Use INQUIRY to get the firmware revision
3947  */
3948 static void idetape_get_inquiry_results (ide_drive_t *drive)
3949 {
3950         char *r;
3951         idetape_tape_t *tape = drive->driver_data;
3952         idetape_pc_t pc;
3953         idetape_inquiry_result_t *inquiry;
3954
3955         idetape_create_inquiry_cmd(&pc);
3956         if (idetape_queue_pc_tail(drive, &pc)) {
3957                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n", tape->name);
3958                 return;
3959         }
3960         inquiry = (idetape_inquiry_result_t *) pc.buffer;
3961         memcpy(tape->vendor_id, inquiry->vendor_id, 8);
3962         memcpy(tape->product_id, inquiry->product_id, 16);
3963         memcpy(tape->firmware_revision, inquiry->revision_level, 4);
3964         ide_fixstring(tape->vendor_id, 10, 0);
3965         ide_fixstring(tape->product_id, 18, 0);
3966         ide_fixstring(tape->firmware_revision, 6, 0);
3967         r = tape->firmware_revision;
3968         if (*(r + 1) == '.')
3969                 tape->firmware_revision_num = (*r - '0') * 100 + (*(r + 2) - '0') * 10 + *(r + 3) - '0';
3970         printk(KERN_INFO "ide-tape: %s <-> %s: %s %s rev %s\n", drive->name, tape->name, tape->vendor_id, tape->product_id, tape->firmware_revision);
3971 }
3972
3973 /*
3974  *      idetape_get_mode_sense_results asks the tape about its various
3975  *      parameters. In particular, we will adjust our data transfer buffer
3976  *      size to the recommended value as returned by the tape.
3977  */
3978 static void idetape_get_mode_sense_results (ide_drive_t *drive)
3979 {
3980         idetape_tape_t *tape = drive->driver_data;
3981         idetape_pc_t pc;
3982         idetape_mode_parameter_header_t *header;
3983         idetape_capabilities_page_t *capabilities;
3984
3985         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
3986         if (idetape_queue_pc_tail(drive, &pc)) {
3987                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming some default values\n");
3988                 tape->tape_block_size = 512;
3989                 tape->capabilities.ctl = 52;
3990                 tape->capabilities.speed = 450;
3991                 tape->capabilities.buffer_size = 6 * 52;
3992                 return;
3993         }
3994         header = (idetape_mode_parameter_header_t *) pc.buffer;
3995         capabilities = (idetape_capabilities_page_t *) (pc.buffer + sizeof(idetape_mode_parameter_header_t) + header->bdl);
3996
3997         capabilities->max_speed = ntohs(capabilities->max_speed);
3998         capabilities->ctl = ntohs(capabilities->ctl);
3999         capabilities->speed = ntohs(capabilities->speed);
4000         capabilities->buffer_size = ntohs(capabilities->buffer_size);
4001
4002         if (!capabilities->speed) {
4003                 printk(KERN_INFO "ide-tape: %s: overriding capabilities->speed (assuming 650KB/sec)\n", drive->name);
4004                 capabilities->speed = 650;
4005         }
4006         if (!capabilities->max_speed) {
4007                 printk(KERN_INFO "ide-tape: %s: overriding capabilities->max_speed (assuming 650KB/sec)\n", drive->name);
4008                 capabilities->max_speed = 650;
4009         }
4010
4011         tape->capabilities = *capabilities;             /* Save us a copy */
4012         if (capabilities->blk512)
4013                 tape->tape_block_size = 512;
4014         else if (capabilities->blk1024)
4015                 tape->tape_block_size = 1024;
4016
4017 #if IDETAPE_DEBUG_INFO
4018         printk(KERN_INFO "ide-tape: Dumping the results of the MODE SENSE packet command\n");
4019         printk(KERN_INFO "ide-tape: Mode Parameter Header:\n");
4020         printk(KERN_INFO "ide-tape: Mode Data Length - %d\n",header->mode_data_length);
4021         printk(KERN_INFO "ide-tape: Medium Type - %d\n",header->medium_type);
4022         printk(KERN_INFO "ide-tape: Device Specific Parameter - %d\n",header->dsp);
4023         printk(KERN_INFO "ide-tape: Block Descriptor Length - %d\n",header->bdl);
4024
4025         printk(KERN_INFO "ide-tape: Capabilities and Mechanical Status Page:\n");
4026         printk(KERN_INFO "ide-tape: Page code - %d\n",capabilities->page_code);
4027         printk(KERN_INFO "ide-tape: Page length - %d\n",capabilities->page_length);
4028         printk(KERN_INFO "ide-tape: Read only - %s\n",capabilities->ro ? "Yes":"No");
4029         printk(KERN_INFO "ide-tape: Supports reverse space - %s\n",capabilities->sprev ? "Yes":"No");
4030         printk(KERN_INFO "ide-tape: Supports erase initiated formatting - %s\n",capabilities->efmt ? "Yes":"No");
4031         printk(KERN_INFO "ide-tape: Supports QFA two Partition format - %s\n",capabilities->qfa ? "Yes":"No");
4032         printk(KERN_INFO "ide-tape: Supports locking the medium - %s\n",capabilities->lock ? "Yes":"No");
4033         printk(KERN_INFO "ide-tape: The volume is currently locked - %s\n",capabilities->locked ? "Yes":"No");
4034         printk(KERN_INFO "ide-tape: The device defaults in the prevent state - %s\n",capabilities->prevent ? "Yes":"No");
4035         printk(KERN_INFO "ide-tape: Supports ejecting the medium - %s\n",capabilities->eject ? "Yes":"No");
4036         printk(KERN_INFO "ide-tape: Supports error correction - %s\n",capabilities->ecc ? "Yes":"No");
4037         printk(KERN_INFO "ide-tape: Supports data compression - %s\n",capabilities->cmprs ? "Yes":"No");
4038         printk(KERN_INFO "ide-tape: Supports 512 bytes block size - %s\n",capabilities->blk512 ? "Yes":"No");
4039         printk(KERN_INFO "ide-tape: Supports 1024 bytes block size - %s\n",capabilities->blk1024 ? "Yes":"No");
4040         printk(KERN_INFO "ide-tape: Supports 32768 bytes block size / Restricted byte count for PIO transfers - %s\n",capabilities->blk32768 ? "Yes":"No");
4041         printk(KERN_INFO "ide-tape: Maximum supported speed in KBps - %d\n",capabilities->max_speed);
4042         printk(KERN_INFO "ide-tape: Continuous transfer limits in blocks - %d\n",capabilities->ctl);
4043         printk(KERN_INFO "ide-tape: Current speed in KBps - %d\n",capabilities->speed);
4044         printk(KERN_INFO "ide-tape: Buffer size - %d\n",capabilities->buffer_size*512);
4045 #endif /* IDETAPE_DEBUG_INFO */
4046 }
4047
4048 /*
4049  *      ide_get_blocksize_from_block_descriptor does a mode sense page 0 with block descriptor
4050  *      and if it succeeds sets the tape block size with the reported value
4051  */
4052 static void idetape_get_blocksize_from_block_descriptor(ide_drive_t *drive)
4053 {
4054
4055         idetape_tape_t *tape = drive->driver_data;
4056         idetape_pc_t pc;
4057         idetape_mode_parameter_header_t *header;
4058         idetape_parameter_block_descriptor_t *block_descrp;
4059
4060         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
4061         if (idetape_queue_pc_tail(drive, &pc)) {
4062                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
4063                 if (tape->tape_block_size == 0) {
4064                         printk(KERN_WARNING "ide-tape: Cannot deal with zero block size, assume 32k\n");
4065                         tape->tape_block_size =  32768;
4066                 }
4067                 return;
4068         }
4069         header = (idetape_mode_parameter_header_t *) pc.buffer;
4070         block_descrp = (idetape_parameter_block_descriptor_t *) (pc.buffer + sizeof(idetape_mode_parameter_header_t));
4071         tape->tape_block_size =( block_descrp->length[0]<<16) + (block_descrp->length[1]<<8) + block_descrp->length[2];
4072         tape->drv_write_prot = (header->dsp & 0x80) >> 7;
4073
4074 #if IDETAPE_DEBUG_INFO
4075         printk(KERN_INFO "ide-tape: Adjusted block size - %d\n", tape->tape_block_size);
4076 #endif /* IDETAPE_DEBUG_INFO */
4077 }
4078
4079 #ifdef CONFIG_IDE_PROC_FS
4080 static void idetape_add_settings (ide_drive_t *drive)
4081 {
4082         idetape_tape_t *tape = drive->driver_data;
4083
4084 /*
4085  *                      drive   setting name            read/write      data type       min                     max                     mul_factor                      div_factor      data pointer                            set function
4086  */
4087         ide_add_setting(drive,  "buffer",               SETTING_READ,   TYPE_SHORT,     0,                      0xffff,                 1,                              2,              &tape->capabilities.buffer_size,        NULL);
4088         ide_add_setting(drive,  "pipeline_min",         SETTING_RW,     TYPE_INT,       1,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->min_pipeline,                    NULL);
4089         ide_add_setting(drive,  "pipeline",             SETTING_RW,     TYPE_INT,       1,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->max_stages,                      NULL);
4090         ide_add_setting(drive,  "pipeline_max",         SETTING_RW,     TYPE_INT,       1,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->max_pipeline,                    NULL);
4091         ide_add_setting(drive,  "pipeline_used",        SETTING_READ,   TYPE_INT,       0,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->nr_stages,                       NULL);
4092         ide_add_setting(drive,  "pipeline_pending",     SETTING_READ,   TYPE_INT,       0,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->nr_pending_stages,               NULL);
4093         ide_add_setting(drive,  "speed",                SETTING_READ,   TYPE_SHORT,     0,                      0xffff,                 1,                              1,              &tape->capabilities.speed,              NULL);
4094         ide_add_setting(drive,  "stage",                SETTING_READ,   TYPE_INT,       0,                      0xffff,                 1,                              1024,           &tape->stage_size,                      NULL);
4095         ide_add_setting(drive,  "tdsc",                 SETTING_RW,     TYPE_INT,       IDETAPE_DSC_RW_MIN,     IDETAPE_DSC_RW_MAX,     1000,                           HZ,             &tape->best_dsc_rw_frequency,           NULL);
4096         ide_add_setting(drive,  "dsc_overlap",          SETTING_RW,     TYPE_BYTE,      0,                      1,                      1,                              1,              &drive->dsc_overlap,                    NULL);
4097         ide_add_setting(drive,  "pipeline_head_speed_c",SETTING_READ,   TYPE_INT,       0,                      0xffff,                 1,                              1,              &tape->controlled_pipeline_head_speed,  NULL);
4098         ide_add_setting(drive,  "pipeline_head_speed_u",SETTING_READ,   TYPE_INT,       0,                      0xffff,                 1,                              1,              &tape->uncontrolled_pipeline_head_speed,NULL);
4099         ide_add_setting(drive,  "avg_speed",            SETTING_READ,   TYPE_INT,       0,                      0xffff,                 1,                              1,              &tape->avg_speed,                       NULL);
4100         ide_add_setting(drive,  "debug_level",          SETTING_RW,     TYPE_INT,       0,                      0xffff,                 1,                              1,              &tape->debug_level,                     NULL);
4101 }
4102 #else
4103 static inline void idetape_add_settings(ide_drive_t *drive) { ; }
4104 #endif
4105
4106 /*
4107  *      ide_setup is called to:
4108  *
4109  *              1.      Initialize our various state variables.
4110  *              2.      Ask the tape for its capabilities.
4111  *              3.      Allocate a buffer which will be used for data
4112  *                      transfer. The buffer size is chosen based on
4113  *                      the recommendation which we received in step (2).
4114  *
4115  *      Note that at this point ide.c already assigned us an irq, so that
4116  *      we can queue requests here and wait for their completion.
4117  */
4118 static void idetape_setup (ide_drive_t *drive, idetape_tape_t *tape, int minor)
4119 {
4120         unsigned long t1, tmid, tn, t;
4121         int speed;
4122         struct idetape_id_gcw gcw;
4123         int stage_size;
4124         struct sysinfo si;
4125
4126         spin_lock_init(&tape->spinlock);
4127         drive->dsc_overlap = 1;
4128         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
4129                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
4130                                  tape->name);
4131                 drive->dsc_overlap = 0;
4132         }
4133         /* Seagate Travan drives do not support DSC overlap. */
4134         if (strstr(drive->id->model, "Seagate STT3401"))
4135                 drive->dsc_overlap = 0;
4136         tape->minor = minor;
4137         tape->name[0] = 'h';
4138         tape->name[1] = 't';
4139         tape->name[2] = '0' + minor;
4140         tape->chrdev_direction = idetape_direction_none;
4141         tape->pc = tape->pc_stack;
4142         tape->max_insert_speed = 10000;
4143         tape->speed_control = 1;
4144         *((unsigned short *) &gcw) = drive->id->config;
4145         if (gcw.drq_type == 1)
4146                 set_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags);
4147
4148         tape->min_pipeline = tape->max_pipeline = tape->max_stages = 10;
4149
4150         idetape_get_inquiry_results(drive);
4151         idetape_get_mode_sense_results(drive);
4152         idetape_get_blocksize_from_block_descriptor(drive);
4153         tape->user_bs_factor = 1;
4154         tape->stage_size = tape->capabilities.ctl * tape->tape_block_size;
4155         while (tape->stage_size > 0xffff) {
4156                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
4157                 tape->capabilities.ctl /= 2;
4158                 tape->stage_size = tape->capabilities.ctl * tape->tape_block_size;
4159         }
4160         stage_size = tape->stage_size;
4161         tape->pages_per_stage = stage_size / PAGE_SIZE;
4162         if (stage_size % PAGE_SIZE) {
4163                 tape->pages_per_stage++;
4164                 tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE;
4165         }
4166
4167         /*
4168          *      Select the "best" DSC read/write polling frequency
4169          *      and pipeline size.
4170          */
4171         speed = max(tape->capabilities.speed, tape->capabilities.max_speed);
4172
4173         tape->max_stages = speed * 1000 * 10 / tape->stage_size;
4174
4175         /*
4176          *      Limit memory use for pipeline to 10% of physical memory
4177          */
4178         si_meminfo(&si);
4179         if (tape->max_stages * tape->stage_size > si.totalram * si.mem_unit / 10)
4180                 tape->max_stages = si.totalram * si.mem_unit / (10 * tape->stage_size);
4181         tape->max_stages   = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES);
4182         tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES);
4183         tape->max_pipeline = min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES);
4184         if (tape->max_stages == 0)
4185                 tape->max_stages = tape->min_pipeline = tape->max_pipeline = 1;
4186
4187         t1 = (tape->stage_size * HZ) / (speed * 1000);
4188         tmid = (tape->capabilities.buffer_size * 32 * HZ) / (speed * 125);
4189         tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000);
4190
4191         if (tape->max_stages)
4192                 t = tn;
4193         else
4194                 t = t1;
4195
4196         /*
4197          *      Ensure that the number we got makes sense; limit
4198          *      it within IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
4199          */
4200         tape->best_dsc_rw_frequency = max_t(unsigned long, min_t(unsigned long, t, IDETAPE_DSC_RW_MAX), IDETAPE_DSC_RW_MIN);
4201         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
4202                 "%dkB pipeline, %lums tDSC%s\n",
4203                 drive->name, tape->name, tape->capabilities.speed,
4204                 (tape->capabilities.buffer_size * 512) / tape->stage_size,
4205                 tape->stage_size / 1024,
4206                 tape->max_stages * tape->stage_size / 1024,
4207                 tape->best_dsc_rw_frequency * 1000 / HZ,
4208                 drive->using_dma ? ", DMA":"");
4209
4210         idetape_add_settings(drive);
4211 }
4212
4213 static void ide_tape_remove(ide_drive_t *drive)
4214 {
4215         idetape_tape_t *tape = drive->driver_data;
4216
4217         ide_proc_unregister_driver(drive, tape->driver);
4218
4219         ide_unregister_region(tape->disk);
4220
4221         ide_tape_put(tape);
4222 }
4223
4224 static void ide_tape_release(struct kref *kref)
4225 {
4226         struct ide_tape_obj *tape = to_ide_tape(kref);
4227         ide_drive_t *drive = tape->drive;
4228         struct gendisk *g = tape->disk;
4229
4230         BUG_ON(tape->first_stage != NULL || tape->merge_stage_size);
4231
4232         drive->dsc_overlap = 0;
4233         drive->driver_data = NULL;
4234         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
4235         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor + 128));
4236         idetape_devs[tape->minor] = NULL;
4237         g->private_data = NULL;
4238         put_disk(g);
4239         kfree(tape);
4240 }
4241
4242 #ifdef CONFIG_IDE_PROC_FS
4243 static int proc_idetape_read_name
4244         (char *page, char **start, off_t off, int count, int *eof, void *data)
4245 {
4246         ide_drive_t     *drive = (ide_drive_t *) data;
4247         idetape_tape_t  *tape = drive->driver_data;
4248         char            *out = page;
4249         int             len;
4250
4251         len = sprintf(out, "%s\n", tape->name);
4252         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
4253 }
4254
4255 static ide_proc_entry_t idetape_proc[] = {
4256         { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
4257         { "name",       S_IFREG|S_IRUGO,        proc_idetape_read_name, NULL },
4258         { NULL, 0, NULL, NULL }
4259 };
4260 #endif
4261
4262 static int ide_tape_probe(ide_drive_t *);
4263
4264 static ide_driver_t idetape_driver = {
4265         .gen_driver = {
4266                 .owner          = THIS_MODULE,
4267                 .name           = "ide-tape",
4268                 .bus            = &ide_bus_type,
4269         },
4270         .probe                  = ide_tape_probe,
4271         .remove                 = ide_tape_remove,
4272         .version                = IDETAPE_VERSION,
4273         .media                  = ide_tape,
4274         .supports_dsc_overlap   = 1,
4275         .do_request             = idetape_do_request,
4276         .end_request            = idetape_end_request,
4277         .error                  = __ide_error,
4278         .abort                  = __ide_abort,
4279 #ifdef CONFIG_IDE_PROC_FS
4280         .proc                   = idetape_proc,
4281 #endif
4282 };
4283
4284 /*
4285  *      Our character device supporting functions, passed to register_chrdev.
4286  */
4287 static const struct file_operations idetape_fops = {
4288         .owner          = THIS_MODULE,
4289         .read           = idetape_chrdev_read,
4290         .write          = idetape_chrdev_write,
4291         .ioctl          = idetape_chrdev_ioctl,
4292         .open           = idetape_chrdev_open,
4293         .release        = idetape_chrdev_release,
4294 };
4295
4296 static int idetape_open(struct inode *inode, struct file *filp)
4297 {
4298         struct gendisk *disk = inode->i_bdev->bd_disk;
4299         struct ide_tape_obj *tape;
4300
4301         if (!(tape = ide_tape_get(disk)))
4302                 return -ENXIO;
4303
4304         return 0;
4305 }
4306
4307 static int idetape_release(struct inode *inode, struct file *filp)
4308 {
4309         struct gendisk *disk = inode->i_bdev->bd_disk;
4310         struct ide_tape_obj *tape = ide_tape_g(disk);
4311
4312         ide_tape_put(tape);
4313
4314         return 0;
4315 }
4316
4317 static int idetape_ioctl(struct inode *inode, struct file *file,
4318                         unsigned int cmd, unsigned long arg)
4319 {
4320         struct block_device *bdev = inode->i_bdev;
4321         struct ide_tape_obj *tape = ide_tape_g(bdev->bd_disk);
4322         ide_drive_t *drive = tape->drive;
4323         int err = generic_ide_ioctl(drive, file, bdev, cmd, arg);
4324         if (err == -EINVAL)
4325                 err = idetape_blkdev_ioctl(drive, cmd, arg);
4326         return err;
4327 }
4328
4329 static struct block_device_operations idetape_block_ops = {
4330         .owner          = THIS_MODULE,
4331         .open           = idetape_open,
4332         .release        = idetape_release,
4333         .ioctl          = idetape_ioctl,
4334 };
4335
4336 static int ide_tape_probe(ide_drive_t *drive)
4337 {
4338         idetape_tape_t *tape;
4339         struct gendisk *g;
4340         int minor;
4341
4342         if (!strstr("ide-tape", drive->driver_req))
4343                 goto failed;
4344         if (!drive->present)
4345                 goto failed;
4346         if (drive->media != ide_tape)
4347                 goto failed;
4348         if (!idetape_identify_device (drive)) {
4349                 printk(KERN_ERR "ide-tape: %s: not supported by this version of ide-tape\n", drive->name);
4350                 goto failed;
4351         }
4352         if (drive->scsi) {
4353                 printk("ide-tape: passing drive %s to ide-scsi emulation.\n", drive->name);
4354                 goto failed;
4355         }
4356         if (strstr(drive->id->model, "OnStream DI-")) {
4357                 printk(KERN_WARNING "ide-tape: Use drive %s with ide-scsi emulation and osst.\n", drive->name);
4358                 printk(KERN_WARNING "ide-tape: OnStream support will be removed soon from ide-tape!\n");
4359         }
4360         tape = kzalloc(sizeof (idetape_tape_t), GFP_KERNEL);
4361         if (tape == NULL) {
4362                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape structure\n", drive->name);
4363                 goto failed;
4364         }
4365
4366         g = alloc_disk(1 << PARTN_BITS);
4367         if (!g)
4368                 goto out_free_tape;
4369
4370         ide_init_disk(g, drive);
4371
4372         ide_proc_register_driver(drive, &idetape_driver);
4373
4374         kref_init(&tape->kref);
4375
4376         tape->drive = drive;
4377         tape->driver = &idetape_driver;
4378         tape->disk = g;
4379
4380         g->private_data = &tape->driver;
4381
4382         drive->driver_data = tape;
4383
4384         mutex_lock(&idetape_ref_mutex);
4385         for (minor = 0; idetape_devs[minor]; minor++)
4386                 ;
4387         idetape_devs[minor] = tape;
4388         mutex_unlock(&idetape_ref_mutex);
4389
4390         idetape_setup(drive, tape, minor);
4391
4392         device_create(idetape_sysfs_class, &drive->gendev,
4393                       MKDEV(IDETAPE_MAJOR, minor), "%s", tape->name);
4394         device_create(idetape_sysfs_class, &drive->gendev,
4395                         MKDEV(IDETAPE_MAJOR, minor + 128), "n%s", tape->name);
4396
4397         g->fops = &idetape_block_ops;
4398         ide_register_region(g);
4399
4400         return 0;
4401
4402 out_free_tape:
4403         kfree(tape);
4404 failed:
4405         return -ENODEV;
4406 }
4407
4408 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
4409 MODULE_LICENSE("GPL");
4410
4411 static void __exit idetape_exit (void)
4412 {
4413         driver_unregister(&idetape_driver.gen_driver);
4414         class_destroy(idetape_sysfs_class);
4415         unregister_chrdev(IDETAPE_MAJOR, "ht");
4416 }
4417
4418 static int __init idetape_init(void)
4419 {
4420         int error = 1;
4421         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
4422         if (IS_ERR(idetape_sysfs_class)) {
4423                 idetape_sysfs_class = NULL;
4424                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
4425                 error = -EBUSY;
4426                 goto out;
4427         }
4428
4429         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
4430                 printk(KERN_ERR "ide-tape: Failed to register character device interface\n");
4431                 error = -EBUSY;
4432                 goto out_free_class;
4433         }
4434
4435         error = driver_register(&idetape_driver.gen_driver);
4436         if (error)
4437                 goto out_free_driver;
4438
4439         return 0;
4440
4441 out_free_driver:
4442         driver_unregister(&idetape_driver.gen_driver);
4443 out_free_class:
4444         class_destroy(idetape_sysfs_class);
4445 out:
4446         return error;
4447 }
4448
4449 MODULE_ALIAS("ide:*m-tape*");
4450 module_init(idetape_init);
4451 module_exit(idetape_exit);
4452 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);