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