err.no Git - linux-2.6/blob - drivers/ide/ide-tape.c

   1 /*
   2  * linux/drivers/ide/ide-tape.c         Version 1.19    Nov, 2003
   3  *
   4  * Copyright (C) 1995 - 1999 Gadi Oxman <gadio@netvision.net.il>
   5  *
   6  * $Header$
   7  *
   8  * This driver was constructed as a student project in the software laboratory
   9  * of the faculty of electrical engineering in the Technion - Israel's
  10  * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
  11  *
  12  * It is hereby placed under the terms of the GNU general public license.
  13  * (See linux/COPYING).
  14  */
  15
  16 /*
  17  * IDE ATAPI streaming tape driver.
  18  *
  19  * This driver is a part of the Linux ide driver and works in co-operation
  20  * with linux/drivers/block/ide.c.
  21  *
  22  * The driver, in co-operation with ide.c, basically traverses the
  23  * request-list for the block device interface. The character device
  24  * interface, on the other hand, creates new requests, adds them
  25  * to the request-list of the block device, and waits for their completion.
  26  *
  27  * Pipelined operation mode is now supported on both reads and writes.
  28  *
  29  * The block device major and minor numbers are determined from the
  30  * tape's relative position in the ide interfaces, as explained in ide.c.
  31  *
  32  * The character device interface consists of the following devices:
  33  *
  34  * ht0          major 37, minor 0       first  IDE tape, rewind on close.
  35  * ht1          major 37, minor 1       second IDE tape, rewind on close.
  36  * ...
  37  * nht0         major 37, minor 128     first  IDE tape, no rewind on close.
  38  * nht1         major 37, minor 129     second IDE tape, no rewind on close.
  39  * ...
  40  *
  41  * Run linux/scripts/MAKEDEV.ide to create the above entries.
  42  *
  43  * The general magnetic tape commands compatible interface, as defined by
  44  * include/linux/mtio.h, is accessible through the character device.
  45  *
  46  * General ide driver configuration options, such as the interrupt-unmask
  47  * flag, can be configured by issuing an ioctl to the block device interface,
  48  * as any other ide device.
  49  *
  50  * Our own ide-tape ioctl's can be issued to either the block device or
  51  * the character device interface.
  52  *
  53  * Maximal throughput with minimal bus load will usually be achieved in the
  54  * following scenario:
  55  *
  56  *      1.      ide-tape is operating in the pipelined operation mode.
  57  *      2.      No buffering is performed by the user backup program.
  58  *
  59  * Testing was done with a 2 GB CONNER CTMA 4000 IDE ATAPI Streaming Tape Drive.
  60  *
  61  * Ver 0.1   Nov  1 95   Pre-working code :-)
  62  * Ver 0.2   Nov 23 95   A short backup (few megabytes) and restore procedure
  63  *                        was successful ! (Using tar cvf ... on the block
  64  *                        device interface).
  65  *                       A longer backup resulted in major swapping, bad
  66  *                        overall Linux performance and eventually failed as
  67  *                        we received non serial read-ahead requests from the
  68  *                        buffer cache.
  69  * Ver 0.3   Nov 28 95   Long backups are now possible, thanks to the
  70  *                        character device interface. Linux's responsiveness
  71  *                        and performance doesn't seem to be much affected
  72  *                        from the background backup procedure.
  73  *                       Some general mtio.h magnetic tape operations are
  74  *                        now supported by our character device. As a result,
  75  *                        popular tape utilities are starting to work with
  76  *                        ide tapes :-)
  77  *                       The following configurations were tested:
  78  *                              1. An IDE ATAPI TAPE shares the same interface
  79  *                                 and irq with an IDE ATAPI CDROM.
  80  *                              2. An IDE ATAPI TAPE shares the same interface
  81  *                                 and irq with a normal IDE disk.
  82  *                        Both configurations seemed to work just fine !
  83  *                        However, to be on the safe side, it is meanwhile
  84  *                        recommended to give the IDE TAPE its own interface
  85  *                        and irq.
  86  *                       The one thing which needs to be done here is to
  87  *                        add a "request postpone" feature to ide.c,
  88  *                        so that we won't have to wait for the tape to finish
  89  *                        performing a long media access (DSC) request (such
  90  *                        as a rewind) before we can access the other device
  91  *                        on the same interface. This effect doesn't disturb
  92  *                        normal operation most of the time because read/write
  93  *                        requests are relatively fast, and once we are
  94  *                        performing one tape r/w request, a lot of requests
  95  *                        from the other device can be queued and ide.c will
  96  *                        service all of them after this single tape request.
  97  * Ver 1.0   Dec 11 95   Integrated into Linux 1.3.46 development tree.
  98  *                       On each read / write request, we now ask the drive
  99  *                        if we can transfer a constant number of bytes
 100  *                        (a parameter of the drive) only to its buffers,
 101  *                        without causing actual media access. If we can't,
 102  *                        we just wait until we can by polling the DSC bit.
 103  *                        This ensures that while we are not transferring
 104  *                        more bytes than the constant referred to above, the
 105  *                        interrupt latency will not become too high and
 106  *                        we won't cause an interrupt timeout, as happened
 107  *                        occasionally in the previous version.
 108  *                       While polling for DSC, the current request is
 109  *                        postponed and ide.c is free to handle requests from
 110  *                        the other device. This is handled transparently to
 111  *                        ide.c. The hwgroup locking method which was used
 112  *                        in the previous version was removed.
 113  *                       Use of new general features which are provided by
 114  *                        ide.c for use with atapi devices.
 115  *                        (Programming done by Mark Lord)
 116  *                       Few potential bug fixes (Again, suggested by Mark)
 117  *                       Single character device data transfers are now
 118  *                        not limited in size, as they were before.
 119  *                       We are asking the tape about its recommended
 120  *                        transfer unit and send a larger data transfer
 121  *                        as several transfers of the above size.
 122  *                        For best results, use an integral number of this
 123  *                        basic unit (which is shown during driver
 124  *                        initialization). I will soon add an ioctl to get
 125  *                        this important parameter.
 126  *                       Our data transfer buffer is allocated on startup,
 127  *                        rather than before each data transfer. This should
 128  *                        ensure that we will indeed have a data buffer.
 129  * Ver 1.1   Dec 14 95   Fixed random problems which occurred when the tape
 130  *                        shared an interface with another device.
 131  *                        (poll_for_dsc was a complete mess).
 132  *                       Removed some old (non-active) code which had
 133  *                        to do with supporting buffer cache originated
 134  *                        requests.
 135  *                       The block device interface can now be opened, so
 136  *                        that general ide driver features like the unmask
 137  *                        interrupts flag can be selected with an ioctl.
 138  *                        This is the only use of the block device interface.
 139  *                       New fast pipelined operation mode (currently only on
 140  *                        writes). When using the pipelined mode, the
 141  *                        throughput can potentially reach the maximum
 142  *                        tape supported throughput, regardless of the
 143  *                        user backup program. On my tape drive, it sometimes
 144  *                        boosted performance by a factor of 2. Pipelined
 145  *                        mode is enabled by default, but since it has a few
 146  *                        downfalls as well, you may want to disable it.
 147  *                        A short explanation of the pipelined operation mode
 148  *                        is available below.
 149  * Ver 1.2   Jan  1 96   Eliminated pipelined mode race condition.
 150  *                       Added pipeline read mode. As a result, restores
 151  *                        are now as fast as backups.
 152  *                       Optimized shared interface behavior. The new behavior
 153  *                        typically results in better IDE bus efficiency and
 154  *                        higher tape throughput.
 155  *                       Pre-calculation of the expected read/write request
 156  *                        service time, based on the tape's parameters. In
 157  *                        the pipelined operation mode, this allows us to
 158  *                        adjust our polling frequency to a much lower value,
 159  *                        and thus to dramatically reduce our load on Linux,
 160  *                        without any decrease in performance.
 161  *                       Implemented additional mtio.h operations.
 162  *                       The recommended user block size is returned by
 163  *                        the MTIOCGET ioctl.
 164  *                       Additional minor changes.
 165  * Ver 1.3   Feb  9 96   Fixed pipelined read mode bug which prevented the
 166  *                        use of some block sizes during a restore procedure.
 167  *                       The character device interface will now present a
 168  *                        continuous view of the media - any mix of block sizes
 169  *                        during a backup/restore procedure is supported. The
 170  *                        driver will buffer the requests internally and
 171  *                        convert them to the tape's recommended transfer
 172  *                        unit, making performance almost independent of the
 173  *                        chosen user block size.
 174  *                       Some improvements in error recovery.
 175  *                       By cooperating with ide-dma.c, bus mastering DMA can
 176  *                        now sometimes be used with IDE tape drives as well.
 177  *                        Bus mastering DMA has the potential to dramatically
 178  *                        reduce the CPU's overhead when accessing the device,
 179  *                        and can be enabled by using hdparm -d1 on the tape's
 180  *                        block device interface. For more info, read the
 181  *                        comments in ide-dma.c.
 182  * Ver 1.4   Mar 13 96   Fixed serialize support.
 183  * Ver 1.5   Apr 12 96   Fixed shared interface operation, broken in 1.3.85.
 184  *                       Fixed pipelined read mode inefficiency.
 185  *                       Fixed nasty null dereferencing bug.
 186  * Ver 1.6   Aug 16 96   Fixed FPU usage in the driver.
 187  *                       Fixed end of media bug.
 188  * Ver 1.7   Sep 10 96   Minor changes for the CONNER CTT8000-A model.
 189  * Ver 1.8   Sep 26 96   Attempt to find a better balance between good
 190  *                        interactive response and high system throughput.
 191  * Ver 1.9   Nov  5 96   Automatically cross encountered filemarks rather
 192  *                        than requiring an explicit FSF command.
 193  *                       Abort pending requests at end of media.
 194  *                       MTTELL was sometimes returning incorrect results.
 195  *                       Return the real block size in the MTIOCGET ioctl.
 196  *                       Some error recovery bug fixes.
 197  * Ver 1.10  Nov  5 96   Major reorganization.
 198  *                       Reduced CPU overhead a bit by eliminating internal
 199  *                        bounce buffers.
 200  *                       Added module support.
 201  *                       Added multiple tape drives support.
 202  *                       Added partition support.
 203  *                       Rewrote DSC handling.
 204  *                       Some portability fixes.
 205  *                       Removed ide-tape.h.
 206  *                       Additional minor changes.
 207  * Ver 1.11  Dec  2 96   Bug fix in previous DSC timeout handling.
 208  *                       Use ide_stall_queue() for DSC overlap.
 209  *                       Use the maximum speed rather than the current speed
 210  *                        to compute the request service time.
 211  * Ver 1.12  Dec  7 97   Fix random memory overwriting and/or last block data
 212  *                        corruption, which could occur if the total number
 213  *                        of bytes written to the tape was not an integral
 214  *                        number of tape blocks.
 215  *                       Add support for INTERRUPT DRQ devices.
 216  * Ver 1.13  Jan  2 98   Add "speed == 0" work-around for HP COLORADO 5GB
 217  * Ver 1.14  Dec 30 98   Partial fixes for the Sony/AIWA tape drives.
 218  *                       Replace cli()/sti() with hwgroup spinlocks.
 219  * Ver 1.15  Mar 25 99   Fix SMP race condition by replacing hwgroup
 220  *                        spinlock with private per-tape spinlock.
 221  * Ver 1.16  Sep  1 99   Add OnStream tape support.
 222  *                       Abort read pipeline on EOD.
 223  *                       Wait for the tape to become ready in case it returns
 224  *                        "in the process of becoming ready" on open().
 225  *                       Fix zero padding of the last written block in
 226  *                        case the tape block size is larger than PAGE_SIZE.
 227  *                       Decrease the default disconnection time to tn.
 228  * Ver 1.16e Oct  3 99   Minor fixes.
 229  * Ver 1.16e1 Oct 13 99  Patches by Arnold Niessen,
 230  *                          niessen@iae.nl / arnold.niessen@philips.com
 231  *                   GO-1)  Undefined code in idetape_read_position
 232  *                              according to Gadi's email
 233  *                   AJN-1) Minor fix asc == 11 should be asc == 0x11
 234  *                               in idetape_issue_packet_command (did effect
 235  *                               debugging output only)
 236  *                   AJN-2) Added more debugging output, and
 237  *                              added ide-tape: where missing. I would also
 238  *                              like to add tape->name where possible
 239  *                   AJN-3) Added different debug_level's
 240  *                              via /proc/ide/hdc/settings
 241  *                              "debug_level" determines amount of debugging output;
 242  *                              can be changed using /proc/ide/hdx/settings
 243  *                              0 : almost no debugging output
 244  *                              1 : 0+output errors only
 245  *                              2 : 1+output all sensekey/asc
 246  *                              3 : 2+follow all chrdev related procedures
 247  *                              4 : 3+follow all procedures
 248  *                              5 : 4+include pc_stack rq_stack info
 249  *                              6 : 5+USE_COUNT updates
 250  *                   AJN-4) Fixed timeout for retension in idetape_queue_pc_tail
 251  *                              from 5 to 10 minutes
 252  *                   AJN-5) Changed maximum number of blocks to skip when
 253  *                              reading tapes with multiple consecutive write
 254  *                              errors from 100 to 1000 in idetape_get_logical_blk
 255  *                   Proposed changes to code:
 256  *                   1) output "logical_blk_num" via /proc
 257  *                   2) output "current_operation" via /proc
 258  *                   3) Either solve or document the fact that `mt rewind' is
 259  *                      required after reading from /dev/nhtx to be
 260  *                      able to rmmod the idetape module;
 261  *                      Also, sometimes an application finishes but the
 262  *                      device remains `busy' for some time. Same cause ?
 263  *                   Proposed changes to release-notes:
 264  *                   4) write a simple `quickstart' section in the
 265  *                      release notes; I volunteer if you don't want to
 266  *                   5) include a pointer to video4linux in the doc
 267  *                      to stimulate video applications
 268  *                   6) release notes lines 331 and 362: explain what happens
 269  *                      if the application data rate is higher than 1100 KB/s;
 270  *                      similar approach to lower-than-500 kB/s ?
 271  *                   7) 6.6 Comparison; wouldn't it be better to allow different
 272  *                      strategies for read and write ?
 273  *                      Wouldn't it be better to control the tape buffer
 274  *                      contents instead of the bandwidth ?
 275  *                   8) line 536: replace will by would (if I understand
 276  *                      this section correctly, a hypothetical and unwanted situation
 277  *                       is being described)
 278  * Ver 1.16f Dec 15 99   Change place of the secondary OnStream header frames.
 279  * Ver 1.17  Nov 2000 / Jan 2001  Marcel Mol, marcel@mesa.nl
 280  *                      - Add idetape_onstream_mode_sense_tape_parameter_page
 281  *                        function to get tape capacity in frames: tape->capacity.
 282  *                      - Add support for DI-50 drives( or any DI- drive).
 283  *                      - 'workaround' for read error/blank block around block 3000.
 284  *                      - Implement Early warning for end of media for Onstream.
 285  *                      - Cosmetic code changes for readability.
 286  *                      - Idetape_position_tape should not use SKIP bit during
 287  *                        Onstream read recovery.
 288  *                      - Add capacity, logical_blk_num and first/last_frame_position
 289  *                        to /proc/ide/hd?/settings.
 290  *                      - Module use count was gone in the Linux 2.4 driver.
 291  * Ver 1.17a Apr 2001 Willem Riede osst@riede.org
 292  *                      - Get drive's actual block size from mode sense block descriptor
 293  *                      - Limit size of pipeline
 294  * Ver 1.17b Oct 2002   Alan Stern <stern@rowland.harvard.edu>
 295  *                      Changed IDETAPE_MIN_PIPELINE_STAGES to 1 and actually used
 296  *                       it in the code!
 297  *                      Actually removed aborted stages in idetape_abort_pipeline
 298  *                       instead of just changing the command code.
 299  *                      Made the transfer byte count for Request Sense equal to the
 300  *                       actual length of the data transfer.
 301  *                      Changed handling of partial data transfers: they do not
 302  *                       cause DMA errors.
 303  *                      Moved initiation of DMA transfers to the correct place.
 304  *                      Removed reference to unallocated memory.
 305  *                      Made __idetape_discard_read_pipeline return the number of
 306  *                       sectors skipped, not the number of stages.
 307  *                      Replaced errant kfree() calls with __idetape_kfree_stage().
 308  *                      Fixed off-by-one error in testing the pipeline length.
 309  *                      Fixed handling of filemarks in the read pipeline.
 310  *                      Small code optimization for MTBSF and MTBSFM ioctls.
 311  *                      Don't try to unlock the door during device close if is
 312  *                       already unlocked!
 313  *                      Cosmetic fixes to miscellaneous debugging output messages.
 314  *                      Set the minimum /proc/ide/hd?/settings values for "pipeline",
 315  *                       "pipeline_min", and "pipeline_max" to 1.
 316  *
 317  * Here are some words from the first releases of hd.c, which are quoted
 318  * in ide.c and apply here as well:
 319  *
 320  * | Special care is recommended.  Have Fun!
 321  *
 322  */
 323
 324 /*
 325  * An overview of the pipelined operation mode.
 326  *
 327  * In the pipelined write mode, we will usually just add requests to our
 328  * pipeline and return immediately, before we even start to service them. The
 329  * user program will then have enough time to prepare the next request while
 330  * we are still busy servicing previous requests. In the pipelined read mode,
 331  * the situation is similar - we add read-ahead requests into the pipeline,
 332  * before the user even requested them.
 333  *
 334  * The pipeline can be viewed as a "safety net" which will be activated when
 335  * the system load is high and prevents the user backup program from keeping up
 336  * with the current tape speed. At this point, the pipeline will get
 337  * shorter and shorter but the tape will still be streaming at the same speed.
 338  * Assuming we have enough pipeline stages, the system load will hopefully
 339  * decrease before the pipeline is completely empty, and the backup program
 340  * will be able to "catch up" and refill the pipeline again.
 341  *
 342  * When using the pipelined mode, it would be best to disable any type of
 343  * buffering done by the user program, as ide-tape already provides all the
 344  * benefits in the kernel, where it can be done in a more efficient way.
 345  * As we will usually not block the user program on a request, the most
 346  * efficient user code will then be a simple read-write-read-... cycle.
 347  * Any additional logic will usually just slow down the backup process.
 348  *
 349  * Using the pipelined mode, I get a constant over 400 KBps throughput,
 350  * which seems to be the maximum throughput supported by my tape.
 351  *
 352  * However, there are some downfalls:
 353  *
 354  *      1.      We use memory (for data buffers) in proportional to the number
 355  *              of pipeline stages (each stage is about 26 KB with my tape).
 356  *      2.      In the pipelined write mode, we cheat and postpone error codes
 357  *              to the user task. In read mode, the actual tape position
 358  *              will be a bit further than the last requested block.
 359  *
 360  * Concerning (1):
 361  *
 362  *      1.      We allocate stages dynamically only when we need them. When
 363  *              we don't need them, we don't consume additional memory. In
 364  *              case we can't allocate stages, we just manage without them
 365  *              (at the expense of decreased throughput) so when Linux is
 366  *              tight in memory, we will not pose additional difficulties.
 367  *
 368  *      2.      The maximum number of stages (which is, in fact, the maximum
 369  *              amount of memory) which we allocate is limited by the compile
 370  *              time parameter IDETAPE_MAX_PIPELINE_STAGES.
 371  *
 372  *      3.      The maximum number of stages is a controlled parameter - We
 373  *              don't start from the user defined maximum number of stages
 374  *              but from the lower IDETAPE_MIN_PIPELINE_STAGES (again, we
 375  *              will not even allocate this amount of stages if the user
 376  *              program can't handle the speed). We then implement a feedback
 377  *              loop which checks if the pipeline is empty, and if it is, we
 378  *              increase the maximum number of stages as necessary until we
 379  *              reach the optimum value which just manages to keep the tape
 380  *              busy with minimum allocated memory or until we reach
 381  *              IDETAPE_MAX_PIPELINE_STAGES.
 382  *
 383  * Concerning (2):
 384  *
 385  *      In pipelined write mode, ide-tape can not return accurate error codes
 386  *      to the user program since we usually just add the request to the
 387  *      pipeline without waiting for it to be serviced. In case an error
 388  *      occurs, I will report it on the next user request.
 389  *
 390  *      In the pipelined read mode, subsequent read requests or forward
 391  *      filemark spacing will perform correctly, as we preserve all blocks
 392  *      and filemarks which we encountered during our excess read-ahead.
 393  *
 394  *      For accurate tape positioning and error reporting, disabling
 395  *      pipelined mode might be the best option.
 396  *
 397  * You can enable/disable/tune the pipelined operation mode by adjusting
 398  * the compile time parameters below.
 399  */
 400
 401 /*
 402  *      Possible improvements.
 403  *
 404  *      1.      Support for the ATAPI overlap protocol.
 405  *
 406  *              In order to maximize bus throughput, we currently use the DSC
 407  *              overlap method which enables ide.c to service requests from the
 408  *              other device while the tape is busy executing a command. The
 409  *              DSC overlap method involves polling the tape's status register
 410  *              for the DSC bit, and servicing the other device while the tape
 411  *              isn't ready.
 412  *
 413  *              In the current QIC development standard (December 1995),
 414  *              it is recommended that new tape drives will *in addition*
 415  *              implement the ATAPI overlap protocol, which is used for the
 416  *              same purpose - efficient use of the IDE bus, but is interrupt
 417  *              driven and thus has much less CPU overhead.
 418  *
 419  *              ATAPI overlap is likely to be supported in most new ATAPI
 420  *              devices, including new ATAPI cdroms, and thus provides us
 421  *              a method by which we can achieve higher throughput when
 422  *              sharing a (fast) ATA-2 disk with any (slow) new ATAPI device.
 423  */
 424
 425 #define IDETAPE_VERSION "1.19"
 426
 427 #include <linux/config.h>
 428 #include <linux/module.h>
 429 #include <linux/types.h>
 430 #include <linux/string.h>
 431 #include <linux/kernel.h>
 432 #include <linux/delay.h>
 433 #include <linux/timer.h>
 434 #include <linux/mm.h>
 435 #include <linux/interrupt.h>
 436 #include <linux/jiffies.h>
 437 #include <linux/major.h>
 438 #include <linux/errno.h>
 439 #include <linux/genhd.h>
 440 #include <linux/slab.h>
 441 #include <linux/pci.h>
 442 #include <linux/ide.h>
 443 #include <linux/smp_lock.h>
 444 #include <linux/completion.h>
 445 #include <linux/bitops.h>
 446 #include <linux/mutex.h>
 447
 448 #include <asm/byteorder.h>
 449 #include <asm/irq.h>
 450 #include <asm/uaccess.h>
 451 #include <asm/io.h>
 452 #include <asm/unaligned.h>
 453
 454 /*
 455  * partition
 456  */
 457 typedef struct os_partition_s {
 458         __u8    partition_num;
 459         __u8    par_desc_ver;
 460         __u16   wrt_pass_cntr;
 461         __u32   first_frame_addr;
 462         __u32   last_frame_addr;
 463         __u32   eod_frame_addr;
 464 } os_partition_t;
 465
 466 /*
 467  * DAT entry
 468  */
 469 typedef struct os_dat_entry_s {
 470         __u32   blk_sz;
 471         __u16   blk_cnt;
 472         __u8    flags;
 473         __u8    reserved;
 474 } os_dat_entry_t;
 475
 476 /*
 477  * DAT
 478  */
 479 #define OS_DAT_FLAGS_DATA       (0xc)
 480 #define OS_DAT_FLAGS_MARK       (0x1)
 481
 482 typedef struct os_dat_s {
 483         __u8            dat_sz;
 484         __u8            reserved1;
 485         __u8            entry_cnt;
 486         __u8            reserved3;
 487         os_dat_entry_t  dat_list[16];
 488 } os_dat_t;
 489
 490 #include <linux/mtio.h>
 491
 492 /**************************** Tunable parameters *****************************/
 493
 494
 495 /*
 496  *      Pipelined mode parameters.
 497  *
 498  *      We try to use the minimum number of stages which is enough to
 499  *      keep the tape constantly streaming. To accomplish that, we implement
 500  *      a feedback loop around the maximum number of stages:
 501  *
 502  *      We start from MIN maximum stages (we will not even use MIN stages
 503  *      if we don't need them), increment it by RATE*(MAX-MIN)
 504  *      whenever we sense that the pipeline is empty, until we reach
 505  *      the optimum value or until we reach MAX.
 506  *
 507  *      Setting the following parameter to 0 is illegal: the pipelined mode
 508  *      cannot be disabled (calculate_speeds() divides by tape->max_stages.)
 509  */
 510 #define IDETAPE_MIN_PIPELINE_STAGES       1
 511 #define IDETAPE_MAX_PIPELINE_STAGES     400
 512 #define IDETAPE_INCREASE_STAGES_RATE     20
 513
 514 /*
 515  *      The following are used to debug the driver:
 516  *
 517  *      Setting IDETAPE_DEBUG_INFO to 1 will report device capabilities.
 518  *      Setting IDETAPE_DEBUG_LOG to 1 will log driver flow control.
 519  *      Setting IDETAPE_DEBUG_BUGS to 1 will enable self-sanity checks in
 520  *      some places.
 521  *
 522  *      Setting them to 0 will restore normal operation mode:
 523  *
 524  *              1.      Disable logging normal successful operations.
 525  *              2.      Disable self-sanity checks.
 526  *              3.      Errors will still be logged, of course.
 527  *
 528  *      All the #if DEBUG code will be removed some day, when the driver
 529  *      is verified to be stable enough. This will make it much more
 530  *      esthetic.
 531  */
 532 #define IDETAPE_DEBUG_INFO              0
 533 #define IDETAPE_DEBUG_LOG               0
 534 #define IDETAPE_DEBUG_BUGS              1
 535
 536 /*
 537  *      After each failed packet command we issue a request sense command
 538  *      and retry the packet command IDETAPE_MAX_PC_RETRIES times.
 539  *
 540  *      Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
 541  */
 542 #define IDETAPE_MAX_PC_RETRIES          3
 543
 544 /*
 545  *      With each packet command, we allocate a buffer of
 546  *      IDETAPE_PC_BUFFER_SIZE bytes. This is used for several packet
 547  *      commands (Not for READ/WRITE commands).
 548  */
 549 #define IDETAPE_PC_BUFFER_SIZE          256
 550
 551 /*
 552  *      In various places in the driver, we need to allocate storage
 553  *      for packet commands and requests, which will remain valid while
 554  *      we leave the driver to wait for an interrupt or a timeout event.
 555  */
 556 #define IDETAPE_PC_STACK                (10 + IDETAPE_MAX_PC_RETRIES)
 557
 558 /*
 559  * Some drives (for example, Seagate STT3401A Travan) require a very long
 560  * timeout, because they don't return an interrupt or clear their busy bit
 561  * until after the command completes (even retension commands).
 562  */
 563 #define IDETAPE_WAIT_CMD                (900*HZ)
 564
 565 /*
 566  *      The following parameter is used to select the point in the internal
 567  *      tape fifo in which we will start to refill the buffer. Decreasing
 568  *      the following parameter will improve the system's latency and
 569  *      interactive response, while using a high value might improve sytem
 570  *      throughput.
 571  */
 572 #define IDETAPE_FIFO_THRESHOLD          2
 573
 574 /*
 575  *      DSC polling parameters.
 576  *
 577  *      Polling for DSC (a single bit in the status register) is a very
 578  *      important function in ide-tape. There are two cases in which we
 579  *      poll for DSC:
 580  *
 581  *      1.      Before a read/write packet command, to ensure that we
 582  *              can transfer data from/to the tape's data buffers, without
 583  *              causing an actual media access. In case the tape is not
 584  *              ready yet, we take out our request from the device
 585  *              request queue, so that ide.c will service requests from
 586  *              the other device on the same interface meanwhile.
 587  *
 588  *      2.      After the successful initialization of a "media access
 589  *              packet command", which is a command which can take a long
 590  *              time to complete (it can be several seconds or even an hour).
 591  *
 592  *              Again, we postpone our request in the middle to free the bus
 593  *              for the other device. The polling frequency here should be
 594  *              lower than the read/write frequency since those media access
 595  *              commands are slow. We start from a "fast" frequency -
 596  *              IDETAPE_DSC_MA_FAST (one second), and if we don't receive DSC
 597  *              after IDETAPE_DSC_MA_THRESHOLD (5 minutes), we switch it to a
 598  *              lower frequency - IDETAPE_DSC_MA_SLOW (1 minute).
 599  *
 600  *      We also set a timeout for the timer, in case something goes wrong.
 601  *      The timeout should be longer then the maximum execution time of a
 602  *      tape operation.
 603  */
 604
 605 /*
 606  *      DSC timings.
 607  */
 608 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
 609 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
 610 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
 611 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
 612 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
 613 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
 614 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
 615
 616 /*************************** End of tunable parameters ***********************/
 617
 618 /*
 619  *      Debugging/Performance analysis
 620  *
 621  *      I/O trace support
 622  */
 623 #define USE_IOTRACE     0
 624 #if USE_IOTRACE
 625 #include <linux/io_trace.h>
 626 #define IO_IDETAPE_FIFO 500
 627 #endif
 628
 629 /*
 630  *      Read/Write error simulation
 631  */
 632 #define SIMULATE_ERRORS                 0
 633
 634 /*
 635  *      For general magnetic tape device compatibility.
 636  */
 637 typedef enum {
 638         idetape_direction_none,
 639         idetape_direction_read,
 640         idetape_direction_write
 641 } idetape_chrdev_direction_t;
 642
 643 struct idetape_bh {
 644         unsigned short b_size;
 645         atomic_t b_count;
 646         struct idetape_bh *b_reqnext;
 647         char *b_data;
 648 };
 649
 650 /*
 651  *      Our view of a packet command.
 652  */
 653 typedef struct idetape_packet_command_s {
 654         u8 c[12];                               /* Actual packet bytes */
 655         int retries;                            /* On each retry, we increment retries */
 656         int error;                              /* Error code */
 657         int request_transfer;                   /* Bytes to transfer */
 658         int actually_transferred;               /* Bytes actually transferred */
 659         int buffer_size;                        /* Size of our data buffer */
 660         struct idetape_bh *bh;
 661         char *b_data;
 662         int b_count;
 663         u8 *buffer;                             /* Data buffer */
 664         u8 *current_position;                   /* Pointer into the above buffer */
 665         ide_startstop_t (*callback) (ide_drive_t *);    /* Called when this packet command is completed */
 666         u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE];   /* Temporary buffer */
 667         unsigned long flags;                    /* Status/Action bit flags: long for set_bit */
 668 } idetape_pc_t;
 669
 670 /*
 671  *      Packet command flag bits.
 672  */
 673 /* Set when an error is considered normal - We won't retry */
 674 #define PC_ABORT                        0
 675 /* 1 When polling for DSC on a media access command */
 676 #define PC_WAIT_FOR_DSC                 1
 677 /* 1 when we prefer to use DMA if possible */
 678 #define PC_DMA_RECOMMENDED              2
 679 /* 1 while DMA in progress */
 680 #define PC_DMA_IN_PROGRESS              3
 681 /* 1 when encountered problem during DMA */
 682 #define PC_DMA_ERROR                    4
 683 /* Data direction */
 684 #define PC_WRITING                      5
 685
 686 /*
 687  *      Capabilities and Mechanical Status Page
 688  */
 689 typedef struct {
 690         unsigned        page_code       :6;     /* Page code - Should be 0x2a */
 691         __u8            reserved0_6     :1;
 692         __u8            ps              :1;     /* parameters saveable */
 693         __u8            page_length;            /* Page Length - Should be 0x12 */
 694         __u8            reserved2, reserved3;
 695         unsigned        ro              :1;     /* Read Only Mode */
 696         unsigned        reserved4_1234  :4;
 697         unsigned        sprev           :1;     /* Supports SPACE in the reverse direction */
 698         unsigned        reserved4_67    :2;
 699         unsigned        reserved5_012   :3;
 700         unsigned        efmt            :1;     /* Supports ERASE command initiated formatting */
 701         unsigned        reserved5_4     :1;
 702         unsigned        qfa             :1;     /* Supports the QFA two partition formats */
 703         unsigned        reserved5_67    :2;
 704         unsigned        lock            :1;     /* Supports locking the volume */
 705         unsigned        locked          :1;     /* The volume is locked */
 706         unsigned        prevent         :1;     /* The device defaults in the prevent state after power up */
 707         unsigned        eject           :1;     /* The device can eject the volume */
 708         __u8            disconnect      :1;     /* The device can break request > ctl */
 709         __u8            reserved6_5     :1;
 710         unsigned        ecc             :1;     /* Supports error correction */
 711         unsigned        cmprs           :1;     /* Supports data compression */
 712         unsigned        reserved7_0     :1;
 713         unsigned        blk512          :1;     /* Supports 512 bytes block size */
 714         unsigned        blk1024         :1;     /* Supports 1024 bytes block size */
 715         unsigned        reserved7_3_6   :4;
 716         unsigned        blk32768        :1;     /* slowb - the device restricts the byte count for PIO */
 717                                                 /* transfers for slow buffer memory ??? */
 718                                                 /* Also 32768 block size in some cases */
 719         __u16           max_speed;              /* Maximum speed supported in KBps */
 720         __u8            reserved10, reserved11;
 721         __u16           ctl;                    /* Continuous Transfer Limit in blocks */
 722         __u16           speed;                  /* Current Speed, in KBps */
 723         __u16           buffer_size;            /* Buffer Size, in 512 bytes */
 724         __u8            reserved18, reserved19;
 725 } idetape_capabilities_page_t;
 726
 727 /*
 728  *      Block Size Page
 729  */
 730 typedef struct {
 731         unsigned        page_code       :6;     /* Page code - Should be 0x30 */
 732         unsigned        reserved1_6     :1;
 733         unsigned        ps              :1;
 734         __u8            page_length;            /* Page Length - Should be 2 */
 735         __u8            reserved2;
 736         unsigned        play32          :1;
 737         unsigned        play32_5        :1;
 738         unsigned        reserved2_23    :2;
 739         unsigned        record32        :1;
 740         unsigned        record32_5      :1;
 741         unsigned        reserved2_6     :1;
 742         unsigned        one             :1;
 743 } idetape_block_size_page_t;
 744
 745 /*
 746  *      A pipeline stage.
 747  */
 748 typedef struct idetape_stage_s {
 749         struct request rq;                      /* The corresponding request */
 750         struct idetape_bh *bh;                  /* The data buffers */
 751         struct idetape_stage_s *next;           /* Pointer to the next stage */
 752 } idetape_stage_t;
 753
 754 /*
 755  *      REQUEST SENSE packet command result - Data Format.
 756  */
 757 typedef struct {
 758         unsigned        error_code      :7;     /* Current of deferred errors */
 759         unsigned        valid           :1;     /* The information field conforms to QIC-157C */
 760         __u8            reserved1       :8;     /* Segment Number - Reserved */
 761         unsigned        sense_key       :4;     /* Sense Key */
 762         unsigned        reserved2_4     :1;     /* Reserved */
 763         unsigned        ili             :1;     /* Incorrect Length Indicator */
 764         unsigned        eom             :1;     /* End Of Medium */
 765         unsigned        filemark        :1;     /* Filemark */
 766         __u32           information __attribute__ ((packed));
 767         __u8            asl;                    /* Additional sense length (n-7) */
 768         __u32           command_specific;       /* Additional command specific information */
 769         __u8            asc;                    /* Additional Sense Code */
 770         __u8            ascq;                   /* Additional Sense Code Qualifier */
 771         __u8            replaceable_unit_code;  /* Field Replaceable Unit Code */
 772         unsigned        sk_specific1    :7;     /* Sense Key Specific */
 773         unsigned        sksv            :1;     /* Sense Key Specific information is valid */
 774         __u8            sk_specific2;           /* Sense Key Specific */
 775         __u8            sk_specific3;           /* Sense Key Specific */
 776         __u8            pad[2];                 /* Padding to 20 bytes */
 777 } idetape_request_sense_result_t;
 778
 779
 780 /*
 781  *      Most of our global data which we need to save even as we leave the
 782  *      driver due to an interrupt or a timer event is stored in a variable
 783  *      of type idetape_tape_t, defined below.
 784  */
 785 typedef struct ide_tape_obj {
 786         ide_drive_t     *drive;
 787         ide_driver_t    *driver;
 788         struct gendisk  *disk;
 789         struct kref     kref;
 790
 791         /*
 792          *      Since a typical character device operation requires more
 793          *      than one packet command, we provide here enough memory
 794          *      for the maximum of interconnected packet commands.
 795          *      The packet commands are stored in the circular array pc_stack.
 796          *      pc_stack_index points to the last used entry, and warps around
 797          *      to the start when we get to the last array entry.
 798          *
 799          *      pc points to the current processed packet command.
 800          *
 801          *      failed_pc points to the last failed packet command, or contains
 802          *      NULL if we do not need to retry any packet command. This is
 803          *      required since an additional packet command is needed before the
 804          *      retry, to get detailed information on what went wrong.
 805          */
 806         /* Current packet command */
 807         idetape_pc_t *pc;
 808         /* Last failed packet command */
 809         idetape_pc_t *failed_pc;
 810         /* Packet command stack */
 811         idetape_pc_t pc_stack[IDETAPE_PC_STACK];
 812         /* Next free packet command storage space */
 813         int pc_stack_index;
 814         struct request rq_stack[IDETAPE_PC_STACK];
 815         /* We implement a circular array */
 816         int rq_stack_index;
 817
 818         /*
 819          *      DSC polling variables.
 820          *
 821          *      While polling for DSC we use postponed_rq to postpone the
 822          *      current request so that ide.c will be able to service
 823          *      pending requests on the other device. Note that at most
 824          *      we will have only one DSC (usually data transfer) request
 825          *      in the device request queue. Additional requests can be
 826          *      queued in our internal pipeline, but they will be visible
 827          *      to ide.c only one at a time.
 828          */
 829         struct request *postponed_rq;
 830         /* The time in which we started polling for DSC */
 831         unsigned long dsc_polling_start;
 832         /* Timer used to poll for dsc */
 833         struct timer_list dsc_timer;
 834         /* Read/Write dsc polling frequency */
 835         unsigned long best_dsc_rw_frequency;
 836         /* The current polling frequency */
 837         unsigned long dsc_polling_frequency;
 838         /* Maximum waiting time */
 839         unsigned long dsc_timeout;
 840
 841         /*
 842          *      Read position information
 843          */
 844         u8 partition;
 845         /* Current block */
 846         unsigned int first_frame_position;
 847         unsigned int last_frame_position;
 848         unsigned int blocks_in_buffer;
 849
 850         /*
 851          *      Last error information
 852          */
 853         u8 sense_key, asc, ascq;
 854
 855         /*
 856          *      Character device operation
 857          */
 858         unsigned int minor;
 859         /* device name */
 860         char name[4];
 861         /* Current character device data transfer direction */
 862         idetape_chrdev_direction_t chrdev_direction;
 863
 864         /*
 865          *      Device information
 866          */
 867         /* Usually 512 or 1024 bytes */
 868         unsigned short tape_block_size;
 869         int user_bs_factor;
 870         /* Copy of the tape's Capabilities and Mechanical Page */
 871         idetape_capabilities_page_t capabilities;
 872
 873         /*
 874          *      Active data transfer request parameters.
 875          *
 876          *      At most, there is only one ide-tape originated data transfer
 877          *      request in the device request queue. This allows ide.c to
 878          *      easily service requests from the other device when we
 879          *      postpone our active request. In the pipelined operation
 880          *      mode, we use our internal pipeline structure to hold
 881          *      more data requests.
 882          *
 883          *      The data buffer size is chosen based on the tape's
 884          *      recommendation.
 885          */
 886         /* Pointer to the request which is waiting in the device request queue */
 887         struct request *active_data_request;
 888         /* Data buffer size (chosen based on the tape's recommendation */
 889         int stage_size;
 890         idetape_stage_t *merge_stage;
 891         int merge_stage_size;
 892         struct idetape_bh *bh;
 893         char *b_data;
 894         int b_count;
 895
 896         /*
 897          *      Pipeline parameters.
 898          *
 899          *      To accomplish non-pipelined mode, we simply set the following
 900          *      variables to zero (or NULL, where appropriate).
 901          */
 902         /* Number of currently used stages */
 903         int nr_stages;
 904         /* Number of pending stages */
 905         int nr_pending_stages;
 906         /* We will not allocate more than this number of stages */
 907         int max_stages, min_pipeline, max_pipeline;
 908         /* The first stage which will be removed from the pipeline */
 909         idetape_stage_t *first_stage;
 910         /* The currently active stage */
 911         idetape_stage_t *active_stage;
 912         /* Will be serviced after the currently active request */
 913         idetape_stage_t *next_stage;
 914         /* New requests will be added to the pipeline here */
 915         idetape_stage_t *last_stage;
 916         /* Optional free stage which we can use */
 917         idetape_stage_t *cache_stage;
 918         int pages_per_stage;
 919         /* Wasted space in each stage */
 920         int excess_bh_size;
 921
 922         /* Status/Action flags: long for set_bit */
 923         unsigned long flags;
 924         /* protects the ide-tape queue */
 925         spinlock_t spinlock;
 926
 927         /*
 928          * Measures average tape speed
 929          */
 930         unsigned long avg_time;
 931         int avg_size;
 932         int avg_speed;
 933
 934         /* last sense information */
 935         idetape_request_sense_result_t sense;
 936
 937         char vendor_id[10];
 938         char product_id[18];
 939         char firmware_revision[6];
 940         int firmware_revision_num;
 941
 942         /* the door is currently locked */
 943         int door_locked;
 944         /* the tape hardware is write protected */
 945         char drv_write_prot;
 946         /* the tape is write protected (hardware or opened as read-only) */
 947         char write_prot;
 948
 949         /*
 950          * Limit the number of times a request can
 951          * be postponed, to avoid an infinite postpone
 952          * deadlock.
 953          */
 954         /* request postpone count limit */
 955         int postpone_cnt;
 956
 957         /*
 958          * Measures number of frames:
 959          *
 960          * 1. written/read to/from the driver pipeline (pipeline_head).
 961          * 2. written/read to/from the tape buffers (idetape_bh).
 962          * 3. written/read by the tape to/from the media (tape_head).
 963          */
 964         int pipeline_head;
 965         int buffer_head;
 966         int tape_head;
 967         int last_tape_head;
 968
 969         /*
 970          * Speed control at the tape buffers input/output
 971          */
 972         unsigned long insert_time;
 973         int insert_size;
 974         int insert_speed;
 975         int max_insert_speed;
 976         int measure_insert_time;
 977
 978         /*
 979          * Measure tape still time, in milliseconds
 980          */
 981         unsigned long tape_still_time_begin;
 982         int tape_still_time;
 983
 984         /*
 985          * Speed regulation negative feedback loop
 986          */
 987         int speed_control;
 988         int pipeline_head_speed;
 989         int controlled_pipeline_head_speed;
 990         int uncontrolled_pipeline_head_speed;
 991         int controlled_last_pipeline_head;
 992         int uncontrolled_last_pipeline_head;
 993         unsigned long uncontrolled_pipeline_head_time;
 994         unsigned long controlled_pipeline_head_time;
 995         int controlled_previous_pipeline_head;
 996         int uncontrolled_previous_pipeline_head;
 997         unsigned long controlled_previous_head_time;
 998         unsigned long uncontrolled_previous_head_time;
 999         int restart_speed_control_req;
1000
1001         /*
1002          * Debug_level determines amount of debugging output;
1003          * can be changed using /proc/ide/hdx/settings
1004          * 0 : almost no debugging output
1005          * 1 : 0+output errors only
1006          * 2 : 1+output all sensekey/asc
1007          * 3 : 2+follow all chrdev related procedures
1008          * 4 : 3+follow all procedures
1009          * 5 : 4+include pc_stack rq_stack info
1010          * 6 : 5+USE_COUNT updates
1011          */
1012          int debug_level;
1013 } idetape_tape_t;
1014
1015 static DEFINE_MUTEX(idetape_ref_mutex);
1016
1017 static struct class *idetape_sysfs_class;
1018
1019 #define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref)
1020
1021 #define ide_tape_g(disk) \
1022         container_of((disk)->private_data, struct ide_tape_obj, driver)
1023
1024 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
1025 {
1026         struct ide_tape_obj *tape = NULL;
1027
1028         mutex_lock(&idetape_ref_mutex);
1029         tape = ide_tape_g(disk);
1030         if (tape)
1031                 kref_get(&tape->kref);
1032         mutex_unlock(&idetape_ref_mutex);
1033         return tape;
1034 }
1035
1036 static void ide_tape_release(struct kref *);
1037
1038 static void ide_tape_put(struct ide_tape_obj *tape)
1039 {
1040         mutex_lock(&idetape_ref_mutex);
1041         kref_put(&tape->kref, ide_tape_release);
1042         mutex_unlock(&idetape_ref_mutex);
1043 }
1044
1045 /*
1046  *      Tape door status
1047  */
1048 #define DOOR_UNLOCKED                   0
1049 #define DOOR_LOCKED                     1
1050 #define DOOR_EXPLICITLY_LOCKED          2
1051
1052 /*
1053  *      Tape flag bits values.
1054  */
1055 #define IDETAPE_IGNORE_DSC              0
1056 #define IDETAPE_ADDRESS_VALID           1       /* 0 When the tape position is unknown */
1057 #define IDETAPE_BUSY                    2       /* Device already opened */
1058 #define IDETAPE_PIPELINE_ERROR          3       /* Error detected in a pipeline stage */
1059 #define IDETAPE_DETECT_BS               4       /* Attempt to auto-detect the current user block size */
1060 #define IDETAPE_FILEMARK                5       /* Currently on a filemark */
1061 #define IDETAPE_DRQ_INTERRUPT           6       /* DRQ interrupt device */
1062 #define IDETAPE_READ_ERROR              7
1063 #define IDETAPE_PIPELINE_ACTIVE         8       /* pipeline active */
1064 /* 0 = no tape is loaded, so we don't rewind after ejecting */
1065 #define IDETAPE_MEDIUM_PRESENT          9
1066
1067 /*
1068  *      Supported ATAPI tape drives packet commands
1069  */
1070 #define IDETAPE_TEST_UNIT_READY_CMD     0x00
1071 #define IDETAPE_REWIND_CMD              0x01
1072 #define IDETAPE_REQUEST_SENSE_CMD       0x03
1073 #define IDETAPE_READ_CMD                0x08
1074 #define IDETAPE_WRITE_CMD               0x0a
1075 #define IDETAPE_WRITE_FILEMARK_CMD      0x10
1076 #define IDETAPE_SPACE_CMD               0x11
1077 #define IDETAPE_INQUIRY_CMD             0x12
1078 #define IDETAPE_ERASE_CMD               0x19
1079 #define IDETAPE_MODE_SENSE_CMD          0x1a
1080 #define IDETAPE_MODE_SELECT_CMD         0x15
1081 #define IDETAPE_LOAD_UNLOAD_CMD         0x1b
1082 #define IDETAPE_PREVENT_CMD             0x1e
1083 #define IDETAPE_LOCATE_CMD              0x2b
1084 #define IDETAPE_READ_POSITION_CMD       0x34
1085 #define IDETAPE_READ_BUFFER_CMD         0x3c
1086 #define IDETAPE_SET_SPEED_CMD           0xbb
1087
1088 /*
1089  *      Some defines for the READ BUFFER command
1090  */
1091 #define IDETAPE_RETRIEVE_FAULTY_BLOCK   6
1092
1093 /*
1094  *      Some defines for the SPACE command
1095  */
1096 #define IDETAPE_SPACE_OVER_FILEMARK     1
1097 #define IDETAPE_SPACE_TO_EOD            3
1098
1099 /*
1100  *      Some defines for the LOAD UNLOAD command
1101  */
1102 #define IDETAPE_LU_LOAD_MASK            1
1103 #define IDETAPE_LU_RETENSION_MASK       2
1104 #define IDETAPE_LU_EOT_MASK             4
1105
1106 /*
1107  *      Special requests for our block device strategy routine.
1108  *
1109  *      In order to service a character device command, we add special
1110  *      requests to the tail of our block device request queue and wait
1111  *      for their completion.
1112  */
1113
1114 enum {
1115         REQ_IDETAPE_PC1         = (1 << 0), /* packet command (first stage) */
1116         REQ_IDETAPE_PC2         = (1 << 1), /* packet command (second stage) */
1117         REQ_IDETAPE_READ        = (1 << 2),
1118         REQ_IDETAPE_WRITE       = (1 << 3),
1119         REQ_IDETAPE_READ_BUFFER = (1 << 4),
1120 };
1121
1122 /*
1123  *      Error codes which are returned in rq->errors to the higher part
1124  *      of the driver.
1125  */
1126 #define IDETAPE_ERROR_GENERAL           101
1127 #define IDETAPE_ERROR_FILEMARK          102
1128 #define IDETAPE_ERROR_EOD               103
1129
1130 /*
1131  *      The following is used to format the general configuration word of
1132  *      the ATAPI IDENTIFY DEVICE command.
1133  */
1134 struct idetape_id_gcw {
1135         unsigned packet_size            :2;     /* Packet Size */
1136         unsigned reserved234            :3;     /* Reserved */
1137         unsigned drq_type               :2;     /* Command packet DRQ type */
1138         unsigned removable              :1;     /* Removable media */
1139         unsigned device_type            :5;     /* Device type */
1140         unsigned reserved13             :1;     /* Reserved */
1141         unsigned protocol               :2;     /* Protocol type */
1142 };
1143
1144 /*
1145  *      INQUIRY packet command - Data Format (From Table 6-8 of QIC-157C)
1146  */
1147 typedef struct {
1148         unsigned        device_type     :5;     /* Peripheral Device Type */
1149         unsigned        reserved0_765   :3;     /* Peripheral Qualifier - Reserved */
1150         unsigned        reserved1_6t0   :7;     /* Reserved */
1151         unsigned        rmb             :1;     /* Removable Medium Bit */
1152         unsigned        ansi_version    :3;     /* ANSI Version */
1153         unsigned        ecma_version    :3;     /* ECMA Version */
1154         unsigned        iso_version     :2;     /* ISO Version */
1155         unsigned        response_format :4;     /* Response Data Format */
1156         unsigned        reserved3_45    :2;     /* Reserved */
1157         unsigned        reserved3_6     :1;     /* TrmIOP - Reserved */
1158         unsigned        reserved3_7     :1;     /* AENC - Reserved */
1159         __u8            additional_length;      /* Additional Length (total_length-4) */
1160         __u8            rsv5, rsv6, rsv7;       /* Reserved */
1161         __u8            vendor_id[8];           /* Vendor Identification */
1162         __u8            product_id[16];         /* Product Identification */
1163         __u8            revision_level[4];      /* Revision Level */
1164         __u8            vendor_specific[20];    /* Vendor Specific - Optional */
1165         __u8            reserved56t95[40];      /* Reserved - Optional */
1166                                                 /* Additional information may be returned */
1167 } idetape_inquiry_result_t;
1168
1169 /*
1170  *      READ POSITION packet command - Data Format (From Table 6-57)
1171  */
1172 typedef struct {
1173         unsigned        reserved0_10    :2;     /* Reserved */
1174         unsigned        bpu             :1;     /* Block Position Unknown */
1175         unsigned        reserved0_543   :3;     /* Reserved */
1176         unsigned        eop             :1;     /* End Of Partition */
1177         unsigned        bop             :1;     /* Beginning Of Partition */
1178         u8              partition;              /* Partition Number */
1179         u8              reserved2, reserved3;   /* Reserved */
1180         u32             first_block;            /* First Block Location */
1181         u32             last_block;             /* Last Block Location (Optional) */
1182         u8              reserved12;             /* Reserved */
1183         u8              blocks_in_buffer[3];    /* Blocks In Buffer - (Optional) */
1184         u32             bytes_in_buffer;        /* Bytes In Buffer (Optional) */
1185 } idetape_read_position_result_t;
1186
1187 /*
1188  *      Follows structures which are related to the SELECT SENSE / MODE SENSE
1189  *      packet commands. Those packet commands are still not supported
1190  *      by ide-tape.
1191  */
1192 #define IDETAPE_BLOCK_DESCRIPTOR        0
1193 #define IDETAPE_CAPABILITIES_PAGE       0x2a
1194 #define IDETAPE_PARAMTR_PAGE            0x2b   /* Onstream DI-x0 only */
1195 #define IDETAPE_BLOCK_SIZE_PAGE         0x30
1196 #define IDETAPE_BUFFER_FILLING_PAGE     0x33
1197
1198 /*
1199  *      Mode Parameter Header for the MODE SENSE packet command
1200  */
1201 typedef struct {
1202         __u8    mode_data_length;       /* Length of the following data transfer */
1203         __u8    medium_type;            /* Medium Type */
1204         __u8    dsp;                    /* Device Specific Parameter */
1205         __u8    bdl;                    /* Block Descriptor Length */
1206 #if 0
1207         /* data transfer page */
1208         __u8    page_code       :6;
1209         __u8    reserved0_6     :1;
1210         __u8    ps              :1;     /* parameters saveable */
1211         __u8    page_length;            /* page Length == 0x02 */
1212         __u8    reserved2;
1213         __u8    read32k         :1;     /* 32k blk size (data only) */
1214         __u8    read32k5        :1;     /* 32.5k blk size (data&AUX) */
1215         __u8    reserved3_23    :2;
1216         __u8    write32k        :1;     /* 32k blk size (data only) */
1217         __u8    write32k5       :1;     /* 32.5k blk size (data&AUX) */
1218         __u8    reserved3_6     :1;
1219         __u8    streaming       :1;     /* streaming mode enable */
1220 #endif
1221 } idetape_mode_parameter_header_t;
1222
1223 /*
1224  *      Mode Parameter Block Descriptor the MODE SENSE packet command
1225  *
1226  *      Support for block descriptors is optional.
1227  */
1228 typedef struct {
1229         __u8            density_code;           /* Medium density code */
1230         __u8            blocks[3];              /* Number of blocks */
1231         __u8            reserved4;              /* Reserved */
1232         __u8            length[3];              /* Block Length */
1233 } idetape_parameter_block_descriptor_t;
1234
1235 /*
1236  *      The Data Compression Page, as returned by the MODE SENSE packet command.
1237  */
1238 typedef struct {
1239         unsigned        page_code       :6;     /* Page Code - Should be 0xf */
1240         unsigned        reserved0       :1;     /* Reserved */
1241         unsigned        ps              :1;
1242         __u8            page_length;            /* Page Length - Should be 14 */
1243         unsigned        reserved2       :6;     /* Reserved */
1244         unsigned        dcc             :1;     /* Data Compression Capable */
1245         unsigned        dce             :1;     /* Data Compression Enable */
1246         unsigned        reserved3       :5;     /* Reserved */
1247         unsigned        red             :2;     /* Report Exception on Decompression */
1248         unsigned        dde             :1;     /* Data Decompression Enable */
1249         __u32           ca;                     /* Compression Algorithm */
1250         __u32           da;                     /* Decompression Algorithm */
1251         __u8            reserved[4];            /* Reserved */
1252 } idetape_data_compression_page_t;
1253
1254 /*
1255  *      The Medium Partition Page, as returned by the MODE SENSE packet command.
1256  */
1257 typedef struct {
1258         unsigned        page_code       :6;     /* Page Code - Should be 0x11 */
1259         unsigned        reserved1_6     :1;     /* Reserved */
1260         unsigned        ps              :1;
1261         __u8            page_length;            /* Page Length - Should be 6 */
1262         __u8            map;                    /* Maximum Additional Partitions - Should be 0 */
1263         __u8            apd;                    /* Additional Partitions Defined - Should be 0 */
1264         unsigned        reserved4_012   :3;     /* Reserved */
1265         unsigned        psum            :2;     /* Should be 0 */
1266         unsigned        idp             :1;     /* Should be 0 */
1267         unsigned        sdp             :1;     /* Should be 0 */
1268         unsigned        fdp             :1;     /* Fixed Data Partitions */
1269         __u8            mfr;                    /* Medium Format Recognition */
1270         __u8            reserved[2];            /* Reserved */
1271 } idetape_medium_partition_page_t;
1272
1273 /*
1274  *      Run time configurable parameters.
1275  */
1276 typedef struct {
1277         int     dsc_rw_frequency;
1278         int     dsc_media_access_frequency;
1279         int     nr_stages;
1280 } idetape_config_t;
1281
1282 /*
1283  *      The variables below are used for the character device interface.
1284  *      Additional state variables are defined in our ide_drive_t structure.
1285  */
1286 static struct ide_tape_obj * idetape_devs[MAX_HWIFS * MAX_DRIVES];
1287
1288 #define ide_tape_f(file) ((file)->private_data)
1289
1290 static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
1291 {
1292         struct ide_tape_obj *tape = NULL;
1293
1294         mutex_lock(&idetape_ref_mutex);
1295         tape = idetape_devs[i];
1296         if (tape)
1297                 kref_get(&tape->kref);
1298         mutex_unlock(&idetape_ref_mutex);
1299         return tape;
1300 }
1301
1302 /*
1303  *      Function declarations
1304  *
1305  */
1306 static int idetape_chrdev_release (struct inode *inode, struct file *filp);
1307 static void idetape_write_release (ide_drive_t *drive, unsigned int minor);
1308
1309 /*
1310  * Too bad. The drive wants to send us data which we are not ready to accept.
1311  * Just throw it away.
1312  */
1313 static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount)
1314 {
1315         while (bcount--)
1316                 (void) HWIF(drive)->INB(IDE_DATA_REG);
1317 }
1318
1319 static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
1320 {
1321         struct idetape_bh *bh = pc->bh;
1322         int count;
1323
1324         while (bcount) {
1325 #if IDETAPE_DEBUG_BUGS
1326                 if (bh == NULL) {
1327                         printk(KERN_ERR "ide-tape: bh == NULL in "
1328                                 "idetape_input_buffers\n");
1329                         idetape_discard_data(drive, bcount);
1330                         return;
1331                 }
1332 #endif /* IDETAPE_DEBUG_BUGS */
1333                 count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount);
1334                 HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count);
1335                 bcount -= count;
1336                 atomic_add(count, &bh->b_count);
1337                 if (atomic_read(&bh->b_count) == bh->b_size) {
1338                         bh = bh->b_reqnext;
1339                         if (bh)
1340                                 atomic_set(&bh->b_count, 0);
1341                 }
1342         }
1343         pc->bh = bh;
1344 }
1345
1346 static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
1347 {
1348         struct idetape_bh *bh = pc->bh;
1349         int count;
1350
1351         while (bcount) {
1352 #if IDETAPE_DEBUG_BUGS
1353                 if (bh == NULL) {
1354                         printk(KERN_ERR "ide-tape: bh == NULL in "
1355                                 "idetape_output_buffers\n");
1356                         return;
1357                 }
1358 #endif /* IDETAPE_DEBUG_BUGS */
1359                 count = min((unsigned int)pc->b_count, (unsigned int)bcount);
1360                 HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count);
1361                 bcount -= count;
1362                 pc->b_data += count;
1363                 pc->b_count -= count;
1364                 if (!pc->b_count) {
1365                         pc->bh = bh = bh->b_reqnext;
1366                         if (bh) {
1367                                 pc->b_data = bh->b_data;
1368                                 pc->b_count = atomic_read(&bh->b_count);
1369                         }
1370                 }
1371         }
1372 }
1373
1374 static void idetape_update_buffers (idetape_pc_t *pc)
1375 {
1376         struct idetape_bh *bh = pc->bh;
1377         int count;
1378         unsigned int bcount = pc->actually_transferred;
1379
1380         if (test_bit(PC_WRITING, &pc->flags))
1381                 return;
1382         while (bcount) {
1383 #if IDETAPE_DEBUG_BUGS
1384                 if (bh == NULL) {
1385                         printk(KERN_ERR "ide-tape: bh == NULL in "
1386                                 "idetape_update_buffers\n");
1387                         return;
1388                 }
1389 #endif /* IDETAPE_DEBUG_BUGS */
1390                 count = min((unsigned int)bh->b_size, (unsigned int)bcount);
1391                 atomic_set(&bh->b_count, count);
1392                 if (atomic_read(&bh->b_count) == bh->b_size)
1393                         bh = bh->b_reqnext;
1394                 bcount -= count;
1395         }
1396         pc->bh = bh;
1397 }
1398
1399 /*
1400  *      idetape_next_pc_storage returns a pointer to a place in which we can
1401  *      safely store a packet command, even though we intend to leave the
1402  *      driver. A storage space for a maximum of IDETAPE_PC_STACK packet
1403  *      commands is allocated at initialization time.
1404  */
1405 static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive)
1406 {
1407         idetape_tape_t *tape = drive->driver_data;
1408
1409 #if IDETAPE_DEBUG_LOG
1410         if (tape->debug_level >= 5)
1411                 printk(KERN_INFO "ide-tape: pc_stack_index=%d\n",
1412                         tape->pc_stack_index);
1413 #endif /* IDETAPE_DEBUG_LOG */
1414         if (tape->pc_stack_index == IDETAPE_PC_STACK)
1415                 tape->pc_stack_index=0;
1416         return (&tape->pc_stack[tape->pc_stack_index++]);
1417 }
1418
1419 /*
1420  *      idetape_next_rq_storage is used along with idetape_next_pc_storage.
1421  *      Since we queue packet commands in the request queue, we need to
1422  *      allocate a request, along with the allocation of a packet command.
1423  */
1424
1425 /**************************************************************
1426  *                                                            *
1427  *  This should get fixed to use kmalloc(.., GFP_ATOMIC)      *
1428  *  followed later on by kfree().   -ml                       *
1429  *                                                            *
1430  **************************************************************/
1431
1432 static struct request *idetape_next_rq_storage (ide_drive_t *drive)
1433 {
1434         idetape_tape_t *tape = drive->driver_data;
1435
1436 #if IDETAPE_DEBUG_LOG
1437         if (tape->debug_level >= 5)
1438                 printk(KERN_INFO "ide-tape: rq_stack_index=%d\n",
1439                         tape->rq_stack_index);
1440 #endif /* IDETAPE_DEBUG_LOG */
1441         if (tape->rq_stack_index == IDETAPE_PC_STACK)
1442                 tape->rq_stack_index=0;
1443         return (&tape->rq_stack[tape->rq_stack_index++]);
1444 }
1445
1446 /*
1447  *      idetape_init_pc initializes a packet command.
1448  */
1449 static void idetape_init_pc (idetape_pc_t *pc)
1450 {
1451         memset(pc->c, 0, 12);
1452         pc->retries = 0;
1453         pc->flags = 0;
1454         pc->request_transfer = 0;
1455         pc->buffer = pc->pc_buffer;
1456         pc->buffer_size = IDETAPE_PC_BUFFER_SIZE;
1457         pc->bh = NULL;
1458         pc->b_data = NULL;
1459 }
1460
1461 /*
1462  *      idetape_analyze_error is called on each failed packet command retry
1463  *      to analyze the request sense. We currently do not utilize this
1464  *      information.
1465  */
1466 static void idetape_analyze_error (ide_drive_t *drive, idetape_request_sense_result_t *result)
1467 {
1468         idetape_tape_t *tape = drive->driver_data;
1469         idetape_pc_t *pc = tape->failed_pc;
1470
1471         tape->sense     = *result;
1472         tape->sense_key = result->sense_key;
1473         tape->asc       = result->asc;
1474         tape->ascq      = result->ascq;
1475 #if IDETAPE_DEBUG_LOG
1476         /*
1477          *      Without debugging, we only log an error if we decided to
1478          *      give up retrying.
1479          */
1480         if (tape->debug_level >= 1)
1481                 printk(KERN_INFO "ide-tape: pc = %x, sense key = %x, "
1482                         "asc = %x, ascq = %x\n",
1483                         pc->c[0], result->sense_key,
1484                         result->asc, result->ascq);
1485 #endif /* IDETAPE_DEBUG_LOG */
1486
1487         /*
1488          *      Correct pc->actually_transferred by asking the tape.
1489          */
1490         if (test_bit(PC_DMA_ERROR, &pc->flags)) {
1491                 pc->actually_transferred = pc->request_transfer - tape->tape_block_size * ntohl(get_unaligned(&result->information));
1492                 idetape_update_buffers(pc);
1493         }
1494
1495         /*
1496          * If error was the result of a zero-length read or write command,
1497          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
1498          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
1499          */
1500         if ((pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD)
1501             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { /* length==0 */
1502                 if (result->sense_key == 5) {
1503                         /* don't report an error, everything's ok */
1504                         pc->error = 0;
1505                         /* don't retry read/write */
1506                         set_bit(PC_ABORT, &pc->flags);
1507                 }
1508         }
1509         if (pc->c[0] == IDETAPE_READ_CMD && result->filemark) {
1510                 pc->error = IDETAPE_ERROR_FILEMARK;
1511                 set_bit(PC_ABORT, &pc->flags);
1512         }
1513         if (pc->c[0] == IDETAPE_WRITE_CMD) {
1514                 if (result->eom ||
1515                     (result->sense_key == 0xd && result->asc == 0x0 &&
1516                      result->ascq == 0x2)) {
1517                         pc->error = IDETAPE_ERROR_EOD;
1518                         set_bit(PC_ABORT, &pc->flags);
1519                 }
1520         }
1521         if (pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD) {
1522                 if (result->sense_key == 8) {
1523                         pc->error = IDETAPE_ERROR_EOD;
1524                         set_bit(PC_ABORT, &pc->flags);
1525                 }
1526                 if (!test_bit(PC_ABORT, &pc->flags) &&
1527                     pc->actually_transferred)
1528                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
1529         }
1530 }
1531
1532 /*
1533  * idetape_active_next_stage will declare the next stage as "active".
1534  */
1535 static void idetape_active_next_stage (ide_drive_t *drive)
1536 {
1537         idetape_tape_t *tape = drive->driver_data;
1538         idetape_stage_t *stage = tape->next_stage;
1539         struct request *rq = &stage->rq;
1540
1541 #if IDETAPE_DEBUG_LOG
1542         if (tape->debug_level >= 4)
1543                 printk(KERN_INFO "ide-tape: Reached idetape_active_next_stage\n");
1544 #endif /* IDETAPE_DEBUG_LOG */
1545 #if IDETAPE_DEBUG_BUGS
1546         if (stage == NULL) {
1547                 printk(KERN_ERR "ide-tape: bug: Trying to activate a non existing stage\n");
1548                 return;
1549         }
1550 #endif /* IDETAPE_DEBUG_BUGS */
1551
1552         rq->rq_disk = tape->disk;
1553         rq->buffer = NULL;
1554         rq->special = (void *)stage->bh;
1555         tape->active_data_request = rq;
1556         tape->active_stage = stage;
1557         tape->next_stage = stage->next;
1558 }
1559
1560 /*
1561  *      idetape_increase_max_pipeline_stages is a part of the feedback
1562  *      loop which tries to find the optimum number of stages. In the
1563  *      feedback loop, we are starting from a minimum maximum number of
1564  *      stages, and if we sense that the pipeline is empty, we try to
1565  *      increase it, until we reach the user compile time memory limit.
1566  */
1567 static void idetape_increase_max_pipeline_stages (ide_drive_t *drive)
1568 {
1569         idetape_tape_t *tape = drive->driver_data;
1570         int increase = (tape->max_pipeline - tape->min_pipeline) / 10;
1571
1572 #if IDETAPE_DEBUG_LOG
1573         if (tape->debug_level >= 4)
1574                 printk (KERN_INFO "ide-tape: Reached idetape_increase_max_pipeline_stages\n");
1575 #endif /* IDETAPE_DEBUG_LOG */
1576
1577         tape->max_stages += max(increase, 1);
1578         tape->max_stages = max(tape->max_stages, tape->min_pipeline);
1579         tape->max_stages = min(tape->max_stages, tape->max_pipeline);
1580 }
1581
1582 /*
1583  *      idetape_kfree_stage calls kfree to completely free a stage, along with
1584  *      its related buffers.
1585  */
1586 static void __idetape_kfree_stage (idetape_stage_t *stage)
1587 {
1588         struct idetape_bh *prev_bh, *bh = stage->bh;
1589         int size;
1590
1591         while (bh != NULL) {
1592                 if (bh->b_data != NULL) {
1593                         size = (int) bh->b_size;
1594                         while (size > 0) {
1595                                 free_page((unsigned long) bh->b_data);
1596                                 size -= PAGE_SIZE;
1597                                 bh->b_data += PAGE_SIZE;
1598                         }
1599                 }
1600                 prev_bh = bh;
1601                 bh = bh->b_reqnext;
1602                 kfree(prev_bh);
1603         }
1604         kfree(stage);
1605 }
1606
1607 static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage)
1608 {
1609         __idetape_kfree_stage(stage);
1610 }
1611
1612 /*
1613  *      idetape_remove_stage_head removes tape->first_stage from the pipeline.
1614  *      The caller should avoid race conditions.
1615  */
1616 static void idetape_remove_stage_head (ide_drive_t *drive)
1617 {
1618         idetape_tape_t *tape = drive->driver_data;
1619         idetape_stage_t *stage;
1620
1621 #if IDETAPE_DEBUG_LOG
1622         if (tape->debug_level >= 4)
1623                 printk(KERN_INFO "ide-tape: Reached idetape_remove_stage_head\n");
1624 #endif /* IDETAPE_DEBUG_LOG */
1625 #if IDETAPE_DEBUG_BUGS
1626         if (tape->first_stage == NULL) {
1627                 printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n");
1628                 return;
1629         }
1630         if (tape->active_stage == tape->first_stage) {
1631                 printk(KERN_ERR "ide-tape: bug: Trying to free our active pipeline stage\n");
1632                 return;
1633         }
1634 #endif /* IDETAPE_DEBUG_BUGS */
1635         stage = tape->first_stage;
1636         tape->first_stage = stage->next;
1637         idetape_kfree_stage(tape, stage);
1638         tape->nr_stages--;
1639         if (tape->first_stage == NULL) {
1640                 tape->last_stage = NULL;
1641 #if IDETAPE_DEBUG_BUGS
1642                 if (tape->next_stage != NULL)
1643                         printk(KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n");
1644                 if (tape->nr_stages)
1645                         printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n");
1646 #endif /* IDETAPE_DEBUG_BUGS */
1647         }
1648 }
1649
1650 /*
1651  * This will free all the pipeline stages starting from new_last_stage->next
1652  * to the end of the list, and point tape->last_stage to new_last_stage.
1653  */
1654 static void idetape_abort_pipeline(ide_drive_t *drive,
1655                                    idetape_stage_t *new_last_stage)
1656 {
1657         idetape_tape_t *tape = drive->driver_data;
1658         idetape_stage_t *stage = new_last_stage->next;
1659         idetape_stage_t *nstage;
1660
1661 #if IDETAPE_DEBUG_LOG
1662         if (tape->debug_level >= 4)
1663                 printk(KERN_INFO "ide-tape: %s: idetape_abort_pipeline called\n", tape->name);
1664 #endif
1665         while (stage) {
1666                 nstage = stage->next;
1667                 idetape_kfree_stage(tape, stage);
1668                 --tape->nr_stages;
1669                 --tape->nr_pending_stages;
1670                 stage = nstage;
1671         }
1672         if (new_last_stage)
1673                 new_last_stage->next = NULL;
1674         tape->last_stage = new_last_stage;
1675         tape->next_stage = NULL;
1676 }
1677
1678 /*
1679  *      idetape_end_request is used to finish servicing a request, and to
1680  *      insert a pending pipeline request into the main device queue.
1681  */
1682 static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
1683 {
1684         struct request *rq = HWGROUP(drive)->rq;
1685         idetape_tape_t *tape = drive->driver_data;
1686         unsigned long flags;
1687         int error;
1688         int remove_stage = 0;
1689         idetape_stage_t *active_stage;
1690
1691 #if IDETAPE_DEBUG_LOG
1692         if (tape->debug_level >= 4)
1693         printk(KERN_INFO "ide-tape: Reached idetape_end_request\n");
1694 #endif /* IDETAPE_DEBUG_LOG */
1695
1696         switch (uptodate) {
1697                 case 0: error = IDETAPE_ERROR_GENERAL; break;
1698                 case 1: error = 0; break;
1699                 default: error = uptodate;
1700         }
1701         rq->errors = error;
1702         if (error)
1703                 tape->failed_pc = NULL;
1704
1705         spin_lock_irqsave(&tape->spinlock, flags);
1706
1707         /* The request was a pipelined data transfer request */
1708         if (tape->active_data_request == rq) {
1709                 active_stage = tape->active_stage;
1710                 tape->active_stage = NULL;
1711                 tape->active_data_request = NULL;
1712                 tape->nr_pending_stages--;
1713                 if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
1714                         remove_stage = 1;
1715                         if (error) {
1716                                 set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
1717                                 if (error == IDETAPE_ERROR_EOD)
1718                                         idetape_abort_pipeline(drive, active_stage);
1719                         }
1720                 } else if (rq->cmd[0] & REQ_IDETAPE_READ) {
1721                         if (error == IDETAPE_ERROR_EOD) {
1722                                 set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
1723                                 idetape_abort_pipeline(drive, active_stage);
1724                         }
1725                 }
1726                 if (tape->next_stage != NULL) {
1727                         idetape_active_next_stage(drive);
1728
1729                         /*
1730                          * Insert the next request into the request queue.
1731                          */
1732                         (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
1733                 } else if (!error) {
1734                                 idetape_increase_max_pipeline_stages(drive);
1735                 }
1736         }
1737         ide_end_drive_cmd(drive, 0, 0);
1738 //      blkdev_dequeue_request(rq);
1739 //      drive->rq = NULL;
1740 //      end_that_request_last(rq);
1741
1742         if (remove_stage)
1743                 idetape_remove_stage_head(drive);
1744         if (tape->active_data_request == NULL)
1745                 clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
1746         spin_unlock_irqrestore(&tape->spinlock, flags);
1747         return 0;
1748 }
1749
1750 static ide_startstop_t idetape_request_sense_callback (ide_drive_t *drive)
1751 {
1752         idetape_tape_t *tape = drive->driver_data;
1753
1754 #if IDETAPE_DEBUG_LOG
1755         if (tape->debug_level >= 4)
1756                 printk(KERN_INFO "ide-tape: Reached idetape_request_sense_callback\n");
1757 #endif /* IDETAPE_DEBUG_LOG */
1758         if (!tape->pc->error) {
1759                 idetape_analyze_error(drive, (idetape_request_sense_result_t *) tape->pc->buffer);
1760                 idetape_end_request(drive, 1, 0);
1761         } else {
1762                 printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - Aborting request!\n");
1763                 idetape_end_request(drive, 0, 0);
1764         }
1765         return ide_stopped;
1766 }
1767
1768 static void idetape_create_request_sense_cmd (idetape_pc_t *pc)
1769 {
1770         idetape_init_pc(pc);
1771         pc->c[0] = IDETAPE_REQUEST_SENSE_CMD;
1772         pc->c[4] = 20;
1773         pc->request_transfer = 20;
1774         pc->callback = &idetape_request_sense_callback;
1775 }
1776
1777 static void idetape_init_rq(struct request *rq, u8 cmd)
1778 {
1779         memset(rq, 0, sizeof(*rq));
1780         rq->flags = REQ_SPECIAL;
1781         rq->cmd[0] = cmd;
1782 }
1783
1784 /*
1785  *      idetape_queue_pc_head generates a new packet command request in front
1786  *      of the request queue, before the current request, so that it will be
1787  *      processed immediately, on the next pass through the driver.
1788  *
1789  *      idetape_queue_pc_head is called from the request handling part of
1790  *      the driver (the "bottom" part). Safe storage for the request should
1791  *      be allocated with idetape_next_pc_storage and idetape_next_rq_storage
1792  *      before calling idetape_queue_pc_head.
1793  *
1794  *      Memory for those requests is pre-allocated at initialization time, and
1795  *      is limited to IDETAPE_PC_STACK requests. We assume that we have enough
1796  *      space for the maximum possible number of inter-dependent packet commands.
1797  *
1798  *      The higher level of the driver - The ioctl handler and the character
1799  *      device handling functions should queue request to the lower level part
1800  *      and wait for their completion using idetape_queue_pc_tail or
1801  *      idetape_queue_rw_tail.
1802  */
1803 static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct request *rq)
1804 {
1805         struct ide_tape_obj *tape = drive->driver_data;
1806
1807         idetape_init_rq(rq, REQ_IDETAPE_PC1);
1808         rq->buffer = (char *) pc;
1809         rq->rq_disk = tape->disk;
1810         (void) ide_do_drive_cmd(drive, rq, ide_preempt);
1811 }
1812
1813 /*
1814  *      idetape_retry_pc is called when an error was detected during the
1815  *      last packet command. We queue a request sense packet command in
1816  *      the head of the request list.
1817  */
1818 static ide_startstop_t idetape_retry_pc (ide_drive_t *drive)
1819 {
1820         idetape_tape_t *tape = drive->driver_data;
1821         idetape_pc_t *pc;
1822         struct request *rq;
1823         atapi_error_t error;
1824
1825         error.all = HWIF(drive)->INB(IDE_ERROR_REG);
1826         pc = idetape_next_pc_storage(drive);
1827         rq = idetape_next_rq_storage(drive);
1828         idetape_create_request_sense_cmd(pc);
1829         set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
1830         idetape_queue_pc_head(drive, pc, rq);
1831         return ide_stopped;
1832 }
1833
1834 /*
1835  *      idetape_postpone_request postpones the current request so that
1836  *      ide.c will be able to service requests from another device on
1837  *      the same hwgroup while we are polling for DSC.
1838  */
1839 static void idetape_postpone_request (ide_drive_t *drive)
1840 {
1841         idetape_tape_t *tape = drive->driver_data;
1842
1843 #if IDETAPE_DEBUG_LOG
1844         if (tape->debug_level >= 4)
1845                 printk(KERN_INFO "ide-tape: idetape_postpone_request\n");
1846 #endif
1847         tape->postponed_rq = HWGROUP(drive)->rq;
1848         ide_stall_queue(drive, tape->dsc_polling_frequency);
1849 }
1850
1851 /*
1852  *      idetape_pc_intr is the usual interrupt handler which will be called
1853  *      during a packet command. We will transfer some of the data (as
1854  *      requested by the drive) and will re-point interrupt handler to us.
1855  *      When data transfer is finished, we will act according to the
1856  *      algorithm described before idetape_issue_packet_command.
1857  *
1858  */
1859 static ide_startstop_t idetape_pc_intr (ide_drive_t *drive)
1860 {
1861         ide_hwif_t *hwif = drive->hwif;
1862         idetape_tape_t *tape = drive->driver_data;
1863         atapi_status_t status;
1864         atapi_bcount_t bcount;
1865         atapi_ireason_t ireason;
1866         idetape_pc_t *pc = tape->pc;
1867
1868         unsigned int temp;
1869 #if SIMULATE_ERRORS
1870         static int error_sim_count = 0;
1871 #endif
1872
1873 #if IDETAPE_DEBUG_LOG
1874         if (tape->debug_level >= 4)
1875                 printk(KERN_INFO "ide-tape: Reached idetape_pc_intr "
1876                                 "interrupt handler\n");
1877 #endif /* IDETAPE_DEBUG_LOG */
1878
1879         /* Clear the interrupt */
1880         status.all = HWIF(drive)->INB(IDE_STATUS_REG);
1881
1882         if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
1883                 if (HWIF(drive)->ide_dma_end(drive) || status.b.check) {
1884                         /*
1885                          * A DMA error is sometimes expected. For example,
1886                          * if the tape is crossing a filemark during a
1887                          * READ command, it will issue an irq and position
1888                          * itself before the filemark, so that only a partial
1889                          * data transfer will occur (which causes the DMA
1890                          * error). In that case, we will later ask the tape
1891                          * how much bytes of the original request were
1892                          * actually transferred (we can't receive that
1893                          * information from the DMA engine on most chipsets).
1894                          */
1895
1896                         /*
1897                          * On the contrary, a DMA error is never expected;
1898                          * it usually indicates a hardware error or abort.
1899                          * If the tape crosses a filemark during a READ
1900                          * command, it will issue an irq and position itself
1901                          * after the filemark (not before). Only a partial
1902                          * data transfer will occur, but no DMA error.
1903                          * (AS, 19 Apr 2001)
1904                          */
1905                         set_bit(PC_DMA_ERROR, &pc->flags);
1906                 } else {
1907                         pc->actually_transferred = pc->request_transfer;
1908                         idetape_update_buffers(pc);
1909                 }
1910 #if IDETAPE_DEBUG_LOG
1911                 if (tape->debug_level >= 4)
1912                         printk(KERN_INFO "ide-tape: DMA finished\n");
1913 #endif /* IDETAPE_DEBUG_LOG */
1914         }
1915
1916         /* No more interrupts */
1917         if (!status.b.drq) {
1918 #if IDETAPE_DEBUG_LOG
1919                 if (tape->debug_level >= 2)
1920                         printk(KERN_INFO "ide-tape: Packet command completed, %d bytes transferred\n", pc->actually_transferred);
1921 #endif /* IDETAPE_DEBUG_LOG */
1922                 clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
1923
1924                 local_irq_enable();
1925
1926 #if SIMULATE_ERRORS
1927                 if ((pc->c[0] == IDETAPE_WRITE_CMD ||
1928                      pc->c[0] == IDETAPE_READ_CMD) &&
1929                     (++error_sim_count % 100) == 0) {
1930                         printk(KERN_INFO "ide-tape: %s: simulating error\n",
1931                                 tape->name);
1932                         status.b.check = 1;
1933                 }
1934 #endif
1935                 if (status.b.check && pc->c[0] == IDETAPE_REQUEST_SENSE_CMD)
1936                         status.b.check = 0;
1937                 if (status.b.check || test_bit(PC_DMA_ERROR, &pc->flags)) {     /* Error detected */
1938 #if IDETAPE_DEBUG_LOG
1939                         if (tape->debug_level >= 1)
1940                                 printk(KERN_INFO "ide-tape: %s: I/O error\n",
1941                                         tape->name);
1942 #endif /* IDETAPE_DEBUG_LOG */
1943                         if (pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
1944                                 printk(KERN_ERR "ide-tape: I/O error in request sense command\n");
1945                                 return ide_do_reset(drive);
1946                         }
1947 #if IDETAPE_DEBUG_LOG
1948                         if (tape->debug_level >= 1)
1949                                 printk(KERN_INFO "ide-tape: [cmd %x]: check condition\n", pc->c[0]);
1950 #endif
1951                         /* Retry operation */
1952                         return idetape_retry_pc(drive);
1953                 }
1954                 pc->error = 0;
1955                 if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
1956                     !status.b.dsc) {
1957                         /* Media access command */
1958                         tape->dsc_polling_start = jiffies;
1959                         tape->dsc_polling_frequency = IDETAPE_DSC_MA_FAST;
1960                         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
1961                         /* Allow ide.c to handle other requests */
1962                         idetape_postpone_request(drive);
1963                         return ide_stopped;
1964                 }
1965                 if (tape->failed_pc == pc)
1966                         tape->failed_pc = NULL;
1967                 /* Command finished - Call the callback function */
1968                 return pc->callback(drive);
1969         }
1970         if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
1971                 printk(KERN_ERR "ide-tape: The tape wants to issue more "
1972                                 "interrupts in DMA mode\n");
1973                 printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
1974                 (void)__ide_dma_off(drive);
1975                 return ide_do_reset(drive);
1976         }
1977         /* Get the number of bytes to transfer on this interrupt. */
1978         bcount.b.high = hwif->INB(IDE_BCOUNTH_REG);
1979         bcount.b.low = hwif->INB(IDE_BCOUNTL_REG);
1980
1981         ireason.all = hwif->INB(IDE_IREASON_REG);
1982
1983         if (ireason.b.cod) {
1984                 printk(KERN_ERR "ide-tape: CoD != 0 in idetape_pc_intr\n");
1985                 return ide_do_reset(drive);
1986         }
1987         if (ireason.b.io == test_bit(PC_WRITING, &pc->flags)) {
1988                 /* Hopefully, we will never get here */
1989                 printk(KERN_ERR "ide-tape: We wanted to %s, ",
1990                         ireason.b.io ? "Write":"Read");
1991                 printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n",
1992                         ireason.b.io ? "Read":"Write");
1993                 return ide_do_reset(drive);
1994         }
1995         if (!test_bit(PC_WRITING, &pc->flags)) {
1996                 /* Reading - Check that we have enough space */
1997                 temp = pc->actually_transferred + bcount.all;
1998                 if (temp > pc->request_transfer) {
1999                         if (temp > pc->buffer_size) {
2000                                 printk(KERN_ERR "ide-tape: The tape wants to send us more data than expected - discarding data\n");
2001                                 idetape_discard_data(drive, bcount.all);
2002                                 ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
2003                                 return ide_started;
2004                         }
2005 #if IDETAPE_DEBUG_LOG
2006                         if (tape->debug_level >= 2)
2007                                 printk(KERN_NOTICE "ide-tape: The tape wants to send us more data than expected - allowing transfer\n");
2008 #endif /* IDETAPE_DEBUG_LOG */
2009                 }
2010         }
2011         if (test_bit(PC_WRITING, &pc->flags)) {
2012                 if (pc->bh != NULL)
2013                         idetape_output_buffers(drive, pc, bcount.all);
2014                 else
2015                         /* Write the current buffer */
2016                         HWIF(drive)->atapi_output_bytes(drive, pc->current_position, bcount.all);
2017         } else {
2018                 if (pc->bh != NULL)
2019                         idetape_input_buffers(drive, pc, bcount.all);
2020                 else
2021                         /* Read the current buffer */
2022                         HWIF(drive)->atapi_input_bytes(drive, pc->current_position, bcount.all);
2023         }
2024         /* Update the current position */
2025         pc->actually_transferred += bcount.all;
2026         pc->current_position += bcount.all;
2027 #if IDETAPE_DEBUG_LOG
2028         if (tape->debug_level >= 2)
2029                 printk(KERN_INFO "ide-tape: [cmd %x] transferred %d bytes on that interrupt\n", pc->c[0], bcount.all);
2030 #endif
2031         /* And set the interrupt handler again */
2032         ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
2033         return ide_started;
2034 }
2035
2036 /*
2037  *      Packet Command Interface
2038  *
2039  *      The current Packet Command is available in tape->pc, and will not
2040  *      change until we finish handling it. Each packet command is associated
2041  *      with a callback function that will be called when the command is
2042  *      finished.
2043  *
2044  *      The handling will be done in three stages:
2045  *
2046  *      1.      idetape_issue_packet_command will send the packet command to the
2047  *              drive, and will set the interrupt handler to idetape_pc_intr.
2048  *
2049  *      2.      On each interrupt, idetape_pc_intr will be called. This step
2050  *              will be repeated until the device signals us that no more
2051  *              interrupts will be issued.
2052  *
2053  *      3.      ATAPI Tape media access commands have immediate status with a
2054  *              delayed process. In case of a successful initiation of a
2055  *              media access packet command, the DSC bit will be set when the
2056  *              actual execution of the command is finished.
2057  *              Since the tape drive will not issue an interrupt, we have to
2058  *              poll for this event. In this case, we define the request as
2059  *              "low priority request" by setting rq_status to
2060  *              IDETAPE_RQ_POSTPONED,   set a timer to poll for DSC and exit
2061  *              the driver.
2062  *
2063  *              ide.c will then give higher priority to requests which
2064  *              originate from the other device, until will change rq_status
2065  *              to RQ_ACTIVE.
2066  *
2067  *      4.      When the packet command is finished, it will be checked for errors.
2068  *
2069  *      5.      In case an error was found, we queue a request sense packet
2070  *              command in front of the request queue and retry the operation
2071  *              up to IDETAPE_MAX_PC_RETRIES times.
2072  *
2073  *      6.      In case no error was found, or we decided to give up and not
2074  *              to retry again, the callback function will be called and then
2075  *              we will handle the next request.
2076  *
2077  */
2078 static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
2079 {
2080         ide_hwif_t *hwif = drive->hwif;
2081         idetape_tape_t *tape = drive->driver_data;
2082         idetape_pc_t *pc = tape->pc;
2083         atapi_ireason_t ireason;
2084         int retries = 100;
2085         ide_startstop_t startstop;
2086
2087         if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
2088                 printk(KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n");
2089                 return startstop;
2090         }
2091         ireason.all = hwif->INB(IDE_IREASON_REG);
2092         while (retries-- && (!ireason.b.cod || ireason.b.io)) {
2093                 printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing "
2094                                 "a packet command, retrying\n");
2095                 udelay(100);
2096                 ireason.all = hwif->INB(IDE_IREASON_REG);
2097                 if (retries == 0) {
2098                         printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while "
2099                                         "issuing a packet command, ignoring\n");
2100                         ireason.b.cod = 1;
2101                         ireason.b.io = 0;
2102                 }
2103         }
2104         if (!ireason.b.cod || ireason.b.io) {
2105                 printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing "
2106                                 "a packet command\n");
2107                 return ide_do_reset(drive);
2108         }
2109         /* Set the interrupt routine */
2110         ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
2111 #ifdef CONFIG_BLK_DEV_IDEDMA
2112         /* Begin DMA, if necessary */
2113         if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags))
2114                 hwif->dma_start(drive);
2115 #endif
2116         /* Send the actual packet */
2117         HWIF(drive)->atapi_output_bytes(drive, pc->c, 12);
2118         return ide_started;
2119 }
2120
2121 static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape_pc_t *pc)
2122 {
2123         ide_hwif_t *hwif = drive->hwif;
2124         idetape_tape_t *tape = drive->driver_data;
2125         atapi_bcount_t bcount;
2126         int dma_ok = 0;
2127
2128 #if IDETAPE_DEBUG_BUGS
2129         if (tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD &&
2130             pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
2131                 printk(KERN_ERR "ide-tape: possible ide-tape.c bug - "
2132                         "Two request sense in serial were issued\n");
2133         }
2134 #endif /* IDETAPE_DEBUG_BUGS */
2135
2136         if (tape->failed_pc == NULL && pc->c[0] != IDETAPE_REQUEST_SENSE_CMD)
2137                 tape->failed_pc = pc;
2138         /* Set the current packet command */
2139         tape->pc = pc;
2140
2141         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
2142             test_bit(PC_ABORT, &pc->flags)) {
2143                 /*
2144                  *      We will "abort" retrying a packet command in case
2145                  *      a legitimate error code was received (crossing a
2146                  *      filemark, or end of the media, for example).
2147                  */
2148                 if (!test_bit(PC_ABORT, &pc->flags)) {
2149                         if (!(pc->c[0] == IDETAPE_TEST_UNIT_READY_CMD &&
2150                               tape->sense_key == 2 && tape->asc == 4 &&
2151                              (tape->ascq == 1 || tape->ascq == 8))) {
2152                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
2153                                                 "pc = %2x, key = %2x, "
2154                                                 "asc = %2x, ascq = %2x\n",
2155                                                 tape->name, pc->c[0],
2156                                                 tape->sense_key, tape->asc,
2157                                                 tape->ascq);
2158                         }
2159                         /* Giving up */
2160                         pc->error = IDETAPE_ERROR_GENERAL;
2161                 }
2162                 tape->failed_pc = NULL;
2163                 return pc->callback(drive);
2164         }
2165 #if IDETAPE_DEBUG_LOG
2166         if (tape->debug_level >= 2)
2167                 printk(KERN_INFO "ide-tape: Retry number - %d, cmd = %02X\n", pc->retries, pc->c[0]);
2168 #endif /* IDETAPE_DEBUG_LOG */
2169
2170         pc->retries++;
2171         /* We haven't transferred any data yet */
2172         pc->actually_transferred = 0;
2173         pc->current_position = pc->buffer;
2174         /* Request to transfer the entire buffer at once */
2175         bcount.all = pc->request_transfer;
2176
2177         if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) {
2178                 printk(KERN_WARNING "ide-tape: DMA disabled, "
2179                                 "reverting to PIO\n");
2180                 (void)__ide_dma_off(drive);
2181         }
2182         if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma)
2183                 dma_ok = !hwif->dma_setup(drive);
2184
2185         if (IDE_CONTROL_REG)
2186                 hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
2187         hwif->OUTB(dma_ok ? 1 : 0, IDE_FEATURE_REG);    /* Use PIO/DMA */
2188         hwif->OUTB(bcount.b.high, IDE_BCOUNTH_REG);
2189         hwif->OUTB(bcount.b.low, IDE_BCOUNTL_REG);
2190         hwif->OUTB(drive->select.all, IDE_SELECT_REG);
2191         if (dma_ok)                     /* Will begin DMA later */
2192                 set_bit(PC_DMA_IN_PROGRESS, &pc->flags);
2193         if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) {
2194                 ide_set_handler(drive, &idetape_transfer_pc, IDETAPE_WAIT_CMD, NULL);
2195                 hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
2196                 return ide_started;
2197         } else {
2198                 hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
2199                 return idetape_transfer_pc(drive);
2200         }
2201 }
2202
2203 /*
2204  *      General packet command callback function.
2205  */
2206 static ide_startstop_t idetape_pc_callback (ide_drive_t *drive)
2207 {
2208         idetape_tape_t *tape = drive->driver_data;
2209
2210 #if IDETAPE_DEBUG_LOG
2211         if (tape->debug_level >= 4)
2212                 printk(KERN_INFO "ide-tape: Reached idetape_pc_callback\n");
2213 #endif /* IDETAPE_DEBUG_LOG */
2214
2215         idetape_end_request(drive, tape->pc->error ? 0 : 1, 0);
2216         return ide_stopped;
2217 }
2218
2219 /*
2220  *      A mode sense command is used to "sense" tape parameters.
2221  */
2222 static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code)
2223 {
2224         idetape_init_pc(pc);
2225         pc->c[0] = IDETAPE_MODE_SENSE_CMD;
2226         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
2227                 pc->c[1] = 8;   /* DBD = 1 - Don't return block descriptors */
2228         pc->c[2] = page_code;
2229         /*
2230          * Changed pc->c[3] to 0 (255 will at best return unused info).
2231          *
2232          * For SCSI this byte is defined as subpage instead of high byte
2233          * of length and some IDE drives seem to interpret it this way
2234          * and return an error when 255 is used.
2235          */
2236         pc->c[3] = 0;
2237         pc->c[4] = 255;         /* (We will just discard data in that case) */
2238         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
2239                 pc->request_transfer = 12;
2240         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
2241                 pc->request_transfer = 24;
2242         else
2243                 pc->request_transfer = 50;
2244         pc->callback = &idetape_pc_callback;
2245 }
2246
2247 static void calculate_speeds(ide_drive_t *drive)
2248 {
2249         idetape_tape_t *tape = drive->driver_data;
2250         int full = 125, empty = 75;
2251
2252         if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) {
2253                 tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head;
2254                 tape->controlled_previous_head_time = tape->controlled_pipeline_head_time;
2255                 tape->controlled_last_pipeline_head = tape->pipeline_head;
2256                 tape->controlled_pipeline_head_time = jiffies;
2257         }
2258         if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
2259                 tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time);
2260         else if (time_after(jiffies, tape->controlled_previous_head_time))
2261                 tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time);
2262
2263         if (tape->nr_pending_stages < tape->max_stages /*- 1 */) {
2264                 /* -1 for read mode error recovery */
2265                 if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) {
2266                         tape->uncontrolled_pipeline_head_time = jiffies;
2267                         tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time);
2268                 }
2269         } else {
2270                 tape->uncontrolled_previous_head_time = jiffies;
2271                 tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
2272                 if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) {
2273                         tape->uncontrolled_pipeline_head_time = jiffies;
2274                 }
2275         }
2276         tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed);
2277         if (tape->speed_control == 0) {
2278                 tape->max_insert_speed = 5000;
2279         } else if (tape->speed_control == 1) {
2280                 if (tape->nr_pending_stages >= tape->max_stages / 2)
2281                         tape->max_insert_speed = tape->pipeline_head_speed +
2282                                 (1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages;
2283                 else
2284                         tape->max_insert_speed = 500 +
2285                                 (tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages;
2286                 if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
2287                         tape->max_insert_speed = 5000;
2288         } else if (tape->speed_control == 2) {
2289                 tape->max_insert_speed = tape->pipeline_head_speed * empty / 100 +
2290                         (tape->pipeline_head_speed * full / 100 - tape->pipeline_head_speed * empty / 100) * tape->nr_pending_stages / tape->max_stages;
2291         } else
2292                 tape->max_insert_speed = tape->speed_control;
2293         tape->max_insert_speed = max(tape->max_insert_speed, 500);
2294 }
2295
2296 static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive)
2297 {
2298         idetape_tape_t *tape = drive->driver_data;
2299         idetape_pc_t *pc = tape->pc;
2300         atapi_status_t status;
2301
2302         status.all = HWIF(drive)->INB(IDE_STATUS_REG);
2303         if (status.b.dsc) {
2304                 if (status.b.check) {
2305                         /* Error detected */
2306                         if (pc->c[0] != IDETAPE_TEST_UNIT_READY_CMD)
2307                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
2308                                                 tape->name);
2309                         /* Retry operation */
2310                         return idetape_retry_pc(drive);
2311                 }
2312                 pc->error = 0;
2313                 if (tape->failed_pc == pc)
2314                         tape->failed_pc = NULL;
2315         } else {
2316                 pc->error = IDETAPE_ERROR_GENERAL;
2317                 tape->failed_pc = NULL;
2318         }
2319         return pc->callback(drive);
2320 }
2321
2322 static ide_startstop_t idetape_rw_callback (ide_drive_t *drive)
2323 {
2324         idetape_tape_t *tape = drive->driver_data;
2325         struct request *rq = HWGROUP(drive)->rq;
2326         int blocks = tape->pc->actually_transferred / tape->tape_block_size;
2327
2328         tape->avg_size += blocks * tape->tape_block_size;
2329         tape->insert_size += blocks * tape->tape_block_size;
2330         if (tape->insert_size > 1024 * 1024)
2331                 tape->measure_insert_time = 1;
2332         if (tape->measure_insert_time) {
2333                 tape->measure_insert_time = 0;
2334                 tape->insert_time = jiffies;
2335                 tape->insert_size = 0;
2336         }
2337         if (time_after(jiffies, tape->insert_time))
2338                 tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
2339         if (time_after_eq(jiffies, tape->avg_time + HZ)) {
2340                 tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024;
2341                 tape->avg_size = 0;
2342                 tape->avg_time = jiffies;
2343         }
2344
2345 #if IDETAPE_DEBUG_LOG
2346         if (tape->debug_level >= 4)
2347                 printk(KERN_INFO "ide-tape: Reached idetape_rw_callback\n");
2348 #endif /* IDETAPE_DEBUG_LOG */
2349
2350         tape->first_frame_position += blocks;
2351         rq->current_nr_sectors -= blocks;
2352
2353         if (!tape->pc->error)
2354                 idetape_end_request(drive, 1, 0);
2355         else
2356                 idetape_end_request(drive, tape->pc->error, 0);
2357         return ide_stopped;
2358 }
2359
2360 static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
2361 {
2362         idetape_init_pc(pc);
2363         pc->c[0] = IDETAPE_READ_CMD;
2364         put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
2365         pc->c[1] = 1;
2366         pc->callback = &idetape_rw_callback;
2367         pc->bh = bh;
2368         atomic_set(&bh->b_count, 0);
2369         pc->buffer = NULL;
2370         pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
2371         if (pc->request_transfer == tape->stage_size)
2372                 set_bit(PC_DMA_RECOMMENDED, &pc->flags);
2373 }
2374
2375 static void idetape_create_read_buffer_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
2376 {
2377         int size = 32768;
2378         struct idetape_bh *p = bh;
2379
2380         idetape_init_pc(pc);
2381         pc->c[0] = IDETAPE_READ_BUFFER_CMD;
2382         pc->c[1] = IDETAPE_RETRIEVE_FAULTY_BLOCK;
2383         pc->c[7] = size >> 8;
2384         pc->c[8] = size & 0xff;
2385         pc->callback = &idetape_pc_callback;
2386         pc->bh = bh;
2387         atomic_set(&bh->b_count, 0);
2388         pc->buffer = NULL;
2389         while (p) {
2390                 atomic_set(&p->b_count, 0);
2391                 p = p->b_reqnext;
2392         }
2393         pc->request_transfer = pc->buffer_size = size;
2394 }
2395
2396 static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
2397 {
2398         idetape_init_pc(pc);
2399         pc->c[0] = IDETAPE_WRITE_CMD;
2400         put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
2401         pc->c[1] = 1;
2402         pc->callback = &idetape_rw_callback;
2403         set_bit(PC_WRITING, &pc->flags);
2404         pc->bh = bh;
2405         pc->b_data = bh->b_data;
2406         pc->b_count = atomic_read(&bh->b_count);
2407         pc->buffer = NULL;
2408         pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
2409         if (pc->request_transfer == tape->stage_size)
2410                 set_bit(PC_DMA_RECOMMENDED, &pc->flags);
2411 }
2412
2413 /*
2414  * idetape_do_request is our request handling function.
2415  */
2416 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
2417                                           struct request *rq, sector_t block)
2418 {
2419         idetape_tape_t *tape = drive->driver_data;
2420         idetape_pc_t *pc = NULL;
2421         struct request *postponed_rq = tape->postponed_rq;
2422         atapi_status_t status;
2423
2424 #if IDETAPE_DEBUG_LOG
2425 #if 0
2426         if (tape->debug_level >= 5)
2427                 printk(KERN_INFO "ide-tape: rq_status: %d, "
2428                         "dev: %s, cmd: %ld, errors: %d\n", rq->rq_status,
2429                          rq->rq_disk->disk_name, rq->cmd[0], rq->errors);
2430 #endif
2431         if (tape->debug_level >= 2)
2432                 printk(KERN_INFO "ide-tape: sector: %ld, "
2433                         "nr_sectors: %ld, current_nr_sectors: %d\n",
2434                         rq->sector, rq->nr_sectors, rq->current_nr_sectors);
2435 #endif /* IDETAPE_DEBUG_LOG */
2436
2437         if ((rq->flags & REQ_SPECIAL) == 0) {
2438                 /*
2439                  * We do not support buffer cache originated requests.
2440                  */
2441                 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
2442                         "request queue (%ld)\n", drive->name, rq->flags);
2443                 ide_end_request(drive, 0, 0);
2444                 return ide_stopped;
2445         }
2446
2447         /*
2448          *      Retry a failed packet command
2449          */
2450         if (tape->failed_pc != NULL &&
2451             tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
2452                 return idetape_issue_packet_command(drive, tape->failed_pc);
2453         }
2454 #if IDETAPE_DEBUG_BUGS
2455         if (postponed_rq != NULL)
2456                 if (rq != postponed_rq) {
2457                         printk(KERN_ERR "ide-tape: ide-tape.c bug - "
2458                                         "Two DSC requests were queued\n");
2459                         idetape_end_request(drive, 0, 0);
2460                         return ide_stopped;
2461                 }
2462 #endif /* IDETAPE_DEBUG_BUGS */
2463
2464         tape->postponed_rq = NULL;
2465
2466         /*
2467          * If the tape is still busy, postpone our request and service
2468          * the other device meanwhile.
2469          */
2470         status.all = HWIF(drive)->INB(IDE_STATUS_REG);
2471
2472         if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2))
2473                 set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
2474
2475         if (drive->post_reset == 1) {
2476                 set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
2477                 drive->post_reset = 0;
2478         }
2479
2480         if (tape->tape_still_time > 100 && tape->tape_still_time < 200)
2481                 tape->measure_insert_time = 1;
2482         if (time_after(jiffies, tape->insert_time))
2483                 tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
2484         calculate_speeds(drive);
2485         if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) &&
2486             !status.b.dsc) {
2487                 if (postponed_rq == NULL) {
2488                         tape->dsc_polling_start = jiffies;
2489                         tape->dsc_polling_frequency = tape->best_dsc_rw_frequency;
2490                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
2491                 } else if (time_after(jiffies, tape->dsc_timeout)) {
2492                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
2493                                 tape->name);
2494                         if (rq->cmd[0] & REQ_IDETAPE_PC2) {
2495                                 idetape_media_access_finished(drive);
2496                                 return ide_stopped;
2497                         } else {
2498                                 return ide_do_reset(drive);
2499                         }
2500                 } else if (time_after(jiffies, tape->dsc_polling_start + IDETAPE_DSC_MA_THRESHOLD))
2501                         tape->dsc_polling_frequency = IDETAPE_DSC_MA_SLOW;
2502                 idetape_postpone_request(drive);
2503                 return ide_stopped;
2504         }
2505         if (rq->cmd[0] & REQ_IDETAPE_READ) {
2506                 tape->buffer_head++;
2507 #if USE_IOTRACE
2508                 IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
2509 #endif
2510                 tape->postpone_cnt = 0;
2511                 pc = idetape_next_pc_storage(drive);
2512                 idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
2513                 goto out;
2514         }
2515         if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
2516                 tape->buffer_head++;
2517 #if USE_IOTRACE
2518                 IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
2519 #endif
2520                 tape->postpone_cnt = 0;
2521                 pc = idetape_next_pc_storage(drive);
2522                 idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
2523                 goto out;
2524         }
2525         if (rq->cmd[0] & REQ_IDETAPE_READ_BUFFER) {
2526                 tape->postpone_cnt = 0;
2527                 pc = idetape_next_pc_storage(drive);
2528                 idetape_create_read_buffer_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
2529                 goto out;
2530         }
2531         if (rq->cmd[0] & REQ_IDETAPE_PC1) {
2532                 pc = (idetape_pc_t *) rq->buffer;
2533                 rq->cmd[0] &= ~(REQ_IDETAPE_PC1);
2534                 rq->cmd[0] |= REQ_IDETAPE_PC2;
2535                 goto out;
2536         }
2537         if (rq->cmd[0] & REQ_IDETAPE_PC2) {
2538                 idetape_media_access_finished(drive);
2539                 return ide_stopped;
2540         }
2541         BUG();
2542 out:
2543         return idetape_issue_packet_command(drive, pc);
2544 }
2545
2546 /*
2547  *      Pipeline related functions
2548  */
2549 static inline int idetape_pipeline_active (idetape_tape_t *tape)
2550 {
2551         int rc1, rc2;
2552
2553         rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
2554         rc2 = (tape->active_data_request != NULL);
2555         return rc1;
2556 }
2557
2558 /*
2559  *      idetape_kmalloc_stage uses __get_free_page to allocate a pipeline
2560  *      stage, along with all the necessary small buffers which together make
2561  *      a buffer of size tape->stage_size (or a bit more). We attempt to
2562  *      combine sequential pages as much as possible.
2563  *
2564  *      Returns a pointer to the new allocated stage, or NULL if we
2565  *      can't (or don't want to) allocate a stage.
2566  *
2567  *      Pipeline stages are optional and are used to increase performance.
2568  *      If we can't allocate them, we'll manage without them.
2569  */
2570 static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape, int full, int clear)
2571 {
2572         idetape_stage_t *stage;
2573         struct idetape_bh *prev_bh, *bh;
2574         int pages = tape->pages_per_stage;
2575         char *b_data = NULL;
2576
2577         if ((stage = (idetape_stage_t *) kmalloc (sizeof (idetape_stage_t),GFP_KERNEL)) == NULL)
2578                 return NULL;
2579         stage->next = NULL;
2580
2581         bh = stage->bh = (struct idetape_bh *)kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
2582         if (bh == NULL)
2583                 goto abort;
2584         bh->b_reqnext = NULL;
2585         if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
2586                 goto abort;
2587         if (clear)
2588                 memset(bh->b_data, 0, PAGE_SIZE);
2589         bh->b_size = PAGE_SIZE;
2590         atomic_set(&bh->b_count, full ? bh->b_size : 0);
2591
2592         while (--pages) {
2593                 if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
2594                         goto abort;
2595                 if (clear)
2596                         memset(b_data, 0, PAGE_SIZE);
2597                 if (bh->b_data == b_data + PAGE_SIZE) {
2598                         bh->b_size += PAGE_SIZE;
2599                         bh->b_data -= PAGE_SIZE;
2600                         if (full)
2601                                 atomic_add(PAGE_SIZE, &bh->b_count);
2602                         continue;
2603                 }
2604                 if (b_data == bh->b_data + bh->b_size) {
2605                         bh->b_size += PAGE_SIZE;
2606                         if (full)
2607                                 atomic_add(PAGE_SIZE, &bh->b_count);
2608                         continue;
2609                 }
2610                 prev_bh = bh;
2611                 if ((bh = (struct idetape_bh *)kmalloc(sizeof(struct idetape_bh), GFP_KERNEL)) == NULL) {
2612                         free_page((unsigned long) b_data);
2613                         goto abort;
2614                 }
2615                 bh->b_reqnext = NULL;
2616                 bh->b_data = b_data;
2617                 bh->b_size = PAGE_SIZE;
2618                 atomic_set(&bh->b_count, full ? bh->b_size : 0);
2619                 prev_bh->b_reqnext = bh;
2620         }
2621         bh->b_size -= tape->excess_bh_size;
2622         if (full)
2623                 atomic_sub(tape->excess_bh_size, &bh->b_count);
2624         return stage;
2625 abort:
2626         __idetape_kfree_stage(stage);
2627         return NULL;
2628 }
2629
2630 static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape)
2631 {
2632         idetape_stage_t *cache_stage = tape->cache_stage;
2633
2634 #if IDETAPE_DEBUG_LOG
2635         if (tape->debug_level >= 4)
2636                 printk(KERN_INFO "ide-tape: Reached idetape_kmalloc_stage\n");
2637 #endif /* IDETAPE_DEBUG_LOG */
2638
2639         if (tape->nr_stages >= tape->max_stages)
2640                 return NULL;
2641         if (cache_stage != NULL) {
2642                 tape->cache_stage = NULL;
2643                 return cache_stage;
2644         }
2645         return __idetape_kmalloc_stage(tape, 0, 0);
2646 }
2647
2648 static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
2649 {
2650         struct idetape_bh *bh = tape->bh;
2651         int count;
2652         int ret = 0;
2653
2654         while (n) {
2655 #if IDETAPE_DEBUG_BUGS
2656                 if (bh == NULL) {
2657                         printk(KERN_ERR "ide-tape: bh == NULL in "
2658                                 "idetape_copy_stage_from_user\n");
2659                         return 1;
2660                 }
2661 #endif /* IDETAPE_DEBUG_BUGS */
2662                 count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
2663                 if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count))
2664                         ret = 1;
2665                 n -= count;
2666                 atomic_add(count, &bh->b_count);
2667                 buf += count;
2668                 if (atomic_read(&bh->b_count) == bh->b_size) {
2669                         bh = bh->b_reqnext;
2670                         if (bh)
2671                                 atomic_set(&bh->b_count, 0);
2672                 }
2673         }
2674         tape->bh = bh;
2675         return ret;
2676 }
2677
2678 static int idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
2679 {
2680         struct idetape_bh *bh = tape->bh;
2681         int count;
2682         int ret = 0;
2683
2684         while (n) {
2685 #if IDETAPE_DEBUG_BUGS
2686                 if (bh == NULL) {
2687                         printk(KERN_ERR "ide-tape: bh == NULL in "
2688                                 "idetape_copy_stage_to_user\n");
2689                         return 1;
2690                 }
2691 #endif /* IDETAPE_DEBUG_BUGS */
2692                 count = min(tape->b_count, n);
2693                 if  (copy_to_user(buf, tape->b_data, count))
2694                         ret = 1;
2695                 n -= count;
2696                 tape->b_data += count;
2697                 tape->b_count -= count;
2698                 buf += count;
2699                 if (!tape->b_count) {
2700                         tape->bh = bh = bh->b_reqnext;
2701                         if (bh) {
2702                                 tape->b_data = bh->b_data;
2703                                 tape->b_count = atomic_read(&bh->b_count);
2704                         }
2705                 }
2706         }
2707         return ret;
2708 }
2709
2710 static void idetape_init_merge_stage (idetape_tape_t *tape)
2711 {
2712         struct idetape_bh *bh = tape->merge_stage->bh;
2713
2714         tape->bh = bh;
2715         if (tape->chrdev_direction == idetape_direction_write)
2716                 atomic_set(&bh->b_count, 0);
2717         else {
2718                 tape->b_data = bh->b_data;
2719                 tape->b_count = atomic_read(&bh->b_count);
2720         }
2721 }
2722
2723 static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage)
2724 {
2725         struct idetape_bh *tmp;
2726
2727         tmp = stage->bh;
2728         stage->bh = tape->merge_stage->bh;
2729         tape->merge_stage->bh = tmp;
2730         idetape_init_merge_stage(tape);
2731 }
2732
2733 /*
2734  *      idetape_add_stage_tail adds a new stage at the end of the pipeline.
2735  */
2736 static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage)
2737 {
2738         idetape_tape_t *tape = drive->driver_data;
2739         unsigned long flags;
2740
2741 #if IDETAPE_DEBUG_LOG
2742         if (tape->debug_level >= 4)
2743                 printk (KERN_INFO "ide-tape: Reached idetape_add_stage_tail\n");
2744 #endif /* IDETAPE_DEBUG_LOG */
2745         spin_lock_irqsave(&tape->spinlock, flags);
2746         stage->next = NULL;
2747         if (tape->last_stage != NULL)
2748                 tape->last_stage->next=stage;
2749         else
2750                 tape->first_stage = tape->next_stage=stage;
2751         tape->last_stage = stage;
2752         if (tape->next_stage == NULL)
2753                 tape->next_stage = tape->last_stage;
2754         tape->nr_stages++;
2755         tape->nr_pending_stages++;
2756         spin_unlock_irqrestore(&tape->spinlock, flags);
2757 }
2758
2759 /*
2760  *      idetape_wait_for_request installs a completion in a pending request
2761  *      and sleeps until it is serviced.
2762  *
2763  *      The caller should ensure that the request will not be serviced
2764  *      before we install the completion (usually by disabling interrupts).
2765  */
2766 static void idetape_wait_for_request (ide_drive_t *drive, struct request *rq)
2767 {
2768         DECLARE_COMPLETION(wait);
2769         idetape_tape_t *tape = drive->driver_data;
2770
2771 #if IDETAPE_DEBUG_BUGS
2772         if (rq == NULL || (rq->flags & REQ_SPECIAL) == 0) {
2773                 printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n");
2774                 return;
2775         }
2776 #endif /* IDETAPE_DEBUG_BUGS */
2777         rq->waiting = &wait;
2778         rq->end_io = blk_end_sync_rq;
2779         spin_unlock_irq(&tape->spinlock);
2780         wait_for_completion(&wait);
2781         /* The stage and its struct request have been deallocated */
2782         spin_lock_irq(&tape->spinlock);
2783 }
2784
2785 static ide_startstop_t idetape_read_position_callback (ide_drive_t *drive)
2786 {
2787         idetape_tape_t *tape = drive->driver_data;
2788         idetape_read_position_result_t *result;
2789
2790 #if IDETAPE_DEBUG_LOG
2791         if (tape->debug_level >= 4)
2792                 printk(KERN_INFO "ide-tape: Reached idetape_read_position_callback\n");
2793 #endif /* IDETAPE_DEBUG_LOG */
2794
2795         if (!tape->pc->error) {
2796                 result = (idetape_read_position_result_t *) tape->pc->buffer;
2797 #if IDETAPE_DEBUG_LOG
2798                 if (tape->debug_level >= 2)
2799                         printk(KERN_INFO "ide-tape: BOP - %s\n",result->bop ? "Yes":"No");
2800                 if (tape->debug_level >= 2)
2801                         printk(KERN_INFO "ide-tape: EOP - %s\n",result->eop ? "Yes":"No");
2802 #endif /* IDETAPE_DEBUG_LOG */
2803                 if (result->bpu) {
2804                         printk(KERN_INFO "ide-tape: Block location is unknown to the tape\n");
2805                         clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
2806                         idetape_end_request(drive, 0, 0);
2807                 } else {
2808 #if IDETAPE_DEBUG_LOG
2809                         if (tape->debug_level >= 2)
2810                                 printk(KERN_INFO "ide-tape: Block Location - %u\n", ntohl(result->first_block));
2811 #endif /* IDETAPE_DEBUG_LOG */
2812                         tape->partition = result->partition;
2813                         tape->first_frame_position = ntohl(result->first_block);
2814                         tape->last_frame_position = ntohl(result->last_block);
2815                         tape->blocks_in_buffer = result->blocks_in_buffer[2];
2816                         set_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
2817                         idetape_end_request(drive, 1, 0);
2818                 }
2819         } else {
2820                 idetape_end_request(drive, 0, 0);
2821         }
2822         return ide_stopped;
2823 }
2824
2825 /*
2826  *      idetape_create_write_filemark_cmd will:
2827  *
2828  *              1.      Write a filemark if write_filemark=1.
2829  *              2.      Flush the device buffers without writing a filemark
2830  *                      if write_filemark=0.
2831  *
2832  */
2833 static void idetape_create_write_filemark_cmd (ide_drive_t *drive, idetape_pc_t *pc,int write_filemark)
2834 {
2835         idetape_init_pc(pc);
2836         pc->c[0] = IDETAPE_WRITE_FILEMARK_CMD;
2837         pc->c[4] = write_filemark;
2838         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2839         pc->callback = &idetape_pc_callback;
2840 }
2841
2842 static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc)
2843 {
2844         idetape_init_pc(pc);
2845         pc->c[0] = IDETAPE_TEST_UNIT_READY_CMD;
2846         pc->callback = &idetape_pc_callback;
2847 }
2848
2849 /*
2850  *      idetape_queue_pc_tail is based on the following functions:
2851  *
2852  *      ide_do_drive_cmd from ide.c
2853  *      cdrom_queue_request and cdrom_queue_packet_command from ide-cd.c
2854  *
2855  *      We add a special packet command request to the tail of the request
2856  *      queue, and wait for it to be serviced.
2857  *
2858  *      This is not to be called from within the request handling part
2859  *      of the driver ! We allocate here data in the stack, and it is valid
2860  *      until the request is finished. This is not the case for the bottom
2861  *      part of the driver, where we are always leaving the functions to wait
2862  *      for an interrupt or a timer event.
2863  *
2864  *      From the bottom part of the driver, we should allocate safe memory
2865  *      using idetape_next_pc_storage and idetape_next_rq_storage, and add
2866  *      the request to the request list without waiting for it to be serviced !
2867  *      In that case, we usually use idetape_queue_pc_head.
2868  */
2869 static int __idetape_queue_pc_tail (ide_drive_t *drive, idetape_pc_t *pc)
2870 {
2871         struct ide_tape_obj *tape = drive->driver_data;
2872         struct request rq;
2873
2874         idetape_init_rq(&rq, REQ_IDETAPE_PC1);
2875         rq.buffer = (char *) pc;
2876         rq.rq_disk = tape->disk;
2877         return ide_do_drive_cmd(drive, &rq, ide_wait);
2878 }
2879
2880 static void idetape_create_load_unload_cmd (ide_drive_t *drive, idetape_pc_t *pc,int cmd)
2881 {
2882         idetape_init_pc(pc);
2883         pc->c[0] = IDETAPE_LOAD_UNLOAD_CMD;
2884         pc->c[4] = cmd;
2885         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2886         pc->callback = &idetape_pc_callback;
2887 }
2888
2889 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
2890 {
2891         idetape_tape_t *tape = drive->driver_data;
2892         idetape_pc_t pc;
2893         int load_attempted = 0;
2894
2895         /*
2896          * Wait for the tape to become ready
2897          */
2898         set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
2899         timeout += jiffies;
2900         while (time_before(jiffies, timeout)) {
2901                 idetape_create_test_unit_ready_cmd(&pc);
2902                 if (!__idetape_queue_pc_tail(drive, &pc))
2903                         return 0;
2904                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
2905                     || (tape->asc == 0x3A)) {   /* no media */
2906                         if (load_attempted)
2907                                 return -ENOMEDIUM;
2908                         idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
2909                         __idetape_queue_pc_tail(drive, &pc);
2910                         load_attempted = 1;
2911                 /* not about to be ready */
2912                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
2913                              (tape->ascq == 1 || tape->ascq == 8)))
2914                         return -EIO;
2915                 msleep(100);
2916         }
2917         return -EIO;
2918 }
2919
2920 static int idetape_queue_pc_tail (ide_drive_t *drive,idetape_pc_t *pc)
2921 {
2922         return __idetape_queue_pc_tail(drive, pc);
2923 }
2924
2925 static int idetape_flush_tape_buffers (ide_drive_t *drive)
2926 {
2927         idetape_pc_t pc;
2928         int rc;
2929
2930         idetape_create_write_filemark_cmd(drive, &pc, 0);
2931         if ((rc = idetape_queue_pc_tail(drive, &pc)))
2932                 return rc;
2933         idetape_wait_ready(drive, 60 * 5 * HZ);
2934         return 0;
2935 }
2936
2937 static void idetape_create_read_position_cmd (idetape_pc_t *pc)
2938 {
2939         idetape_init_pc(pc);
2940         pc->c[0] = IDETAPE_READ_POSITION_CMD;
2941         pc->request_transfer = 20;
2942         pc->callback = &idetape_read_position_callback;
2943 }
2944
2945 static int idetape_read_position (ide_drive_t *drive)
2946 {
2947         idetape_tape_t *tape = drive->driver_data;
2948         idetape_pc_t pc;
2949         int position;
2950
2951 #if IDETAPE_DEBUG_LOG
2952         if (tape->debug_level >= 4)
2953                 printk(KERN_INFO "ide-tape: Reached idetape_read_position\n");
2954 #endif /* IDETAPE_DEBUG_LOG */
2955
2956         idetape_create_read_position_cmd(&pc);
2957         if (idetape_queue_pc_tail(drive, &pc))
2958                 return -1;
2959         position = tape->first_frame_position;
2960         return position;
2961 }
2962
2963 static void idetape_create_locate_cmd (ide_drive_t *drive, idetape_pc_t *pc, unsigned int block, u8 partition, int skip)
2964 {
2965         idetape_init_pc(pc);
2966         pc->c[0] = IDETAPE_LOCATE_CMD;
2967         pc->c[1] = 2;
2968         put_unaligned(htonl(block), (unsigned int *) &pc->c[3]);
2969         pc->c[8] = partition;
2970         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2971         pc->callback = &idetape_pc_callback;
2972 }
2973
2974 static int idetape_create_prevent_cmd (ide_drive_t *drive, idetape_pc_t *pc, int prevent)
2975 {
2976         idetape_tape_t *tape = drive->driver_data;
2977
2978         if (!tape->capabilities.lock)
2979                 return 0;
2980
2981         idetape_init_pc(pc);
2982         pc->c[0] = IDETAPE_PREVENT_CMD;
2983         pc->c[4] = prevent;
2984         pc->callback = &idetape_pc_callback;
2985         return 1;
2986 }
2987
2988 static int __idetape_discard_read_pipeline (ide_drive_t *drive)
2989 {
2990         idetape_tape_t *tape = drive->driver_data;
2991         unsigned long flags;
2992         int cnt;
2993
2994         if (tape->chrdev_direction != idetape_direction_read)
2995                 return 0;
2996
2997         /* Remove merge stage. */
2998         cnt = tape->merge_stage_size / tape->tape_block_size;
2999         if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
3000                 ++cnt;          /* Filemarks count as 1 sector */
3001         tape->merge_stage_size = 0;
3002         if (tape->merge_stage != NULL) {
3003                 __idetape_kfree_stage(tape->merge_stage);
3004                 tape->merge_stage = NULL;
3005         }
3006
3007         /* Clear pipeline flags. */
3008         clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
3009         tape->chrdev_direction = idetape_direction_none;
3010
3011         /* Remove pipeline stages. */
3012         if (tape->first_stage == NULL)
3013                 return 0;
3014
3015         spin_lock_irqsave(&tape->spinlock, flags);
3016         tape->next_stage = NULL;
3017         if (idetape_pipeline_active(tape))
3018                 idetape_wait_for_request(drive, tape->active_data_request);
3019         spin_unlock_irqrestore(&tape->spinlock, flags);
3020
3021         while (tape->first_stage != NULL) {
3022                 struct request *rq_ptr = &tape->first_stage->rq;
3023
3024                 cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors;
3025                 if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
3026                         ++cnt;
3027                 idetape_remove_stage_head(drive);
3028         }
3029         tape->nr_pending_stages = 0;
3030         tape->max_stages = tape->min_pipeline;
3031         return cnt;
3032 }
3033
3034 /*
3035  *      idetape_position_tape positions the tape to the requested block
3036  *      using the LOCATE packet command. A READ POSITION command is then
3037  *      issued to check where we are positioned.
3038  *
3039  *      Like all higher level operations, we queue the commands at the tail
3040  *      of the request queue and wait for their completion.
3041  *
3042  */
3043 static int idetape_position_tape (ide_drive_t *drive, unsigned int block, u8 partition, int skip)
3044 {
3045         idetape_tape_t *tape = drive->driver_data;
3046         int retval;
3047         idetape_pc_t pc;
3048
3049         if (tape->chrdev_direction == idetape_direction_read)
3050                 __idetape_discard_read_pipeline(drive);
3051         idetape_wait_ready(drive, 60 * 5 * HZ);
3052         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
3053         retval = idetape_queue_pc_tail(drive, &pc);
3054         if (retval)
3055                 return (retval);
3056
3057         idetape_create_read_position_cmd(&pc);
3058         return (idetape_queue_pc_tail(drive, &pc));
3059 }
3060
3061 static void idetape_discard_read_pipeline (ide_drive_t *drive, int restore_position)
3062 {
3063         idetape_tape_t *tape = drive->driver_data;
3064         int cnt;
3065         int seek, position;
3066
3067         cnt = __idetape_discard_read_pipeline(drive);
3068         if (restore_position) {
3069                 position = idetape_read_position(drive);
3070                 seek = position > cnt ? position - cnt : 0;
3071                 if (idetape_position_tape(drive, seek, 0, 0)) {
3072                         printk(KERN_INFO "ide-tape: %s: position_tape failed in discard_pipeline()\n", tape->name);
3073                         return;
3074                 }
3075         }
3076 }
3077
3078 /*
3079  * idetape_queue_rw_tail generates a read/write request for the block
3080  * device interface and wait for it to be serviced.
3081  */
3082 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, struct idetape_bh *bh)
3083 {
3084         idetape_tape_t *tape = drive->driver_data;
3085         struct request rq;
3086
3087 #if IDETAPE_DEBUG_LOG
3088         if (tape->debug_level >= 2)
3089                 printk(KERN_INFO "ide-tape: idetape_queue_rw_tail: cmd=%d\n",cmd);
3090 #endif /* IDETAPE_DEBUG_LOG */
3091 #if IDETAPE_DEBUG_BUGS
3092         if (idetape_pipeline_active(tape)) {
3093                 printk(KERN_ERR "ide-tape: bug: the pipeline is active in idetape_queue_rw_tail\n");
3094                 return (0);
3095         }
3096 #endif /* IDETAPE_DEBUG_BUGS */
3097
3098         idetape_init_rq(&rq, cmd);
3099         rq.rq_disk = tape->disk;
3100         rq.special = (void *)bh;
3101         rq.sector = tape->first_frame_position;
3102         rq.nr_sectors = rq.current_nr_sectors = blocks;
3103         (void) ide_do_drive_cmd(drive, &rq, ide_wait);
3104
3105         if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
3106                 return 0;
3107
3108         if (tape->merge_stage)
3109                 idetape_init_merge_stage(tape);
3110         if (rq.errors == IDETAPE_ERROR_GENERAL)
3111                 return -EIO;
3112         return (tape->tape_block_size * (blocks-rq.current_nr_sectors));
3113 }
3114
3115 /*
3116  *      idetape_insert_pipeline_into_queue is used to start servicing the
3117  *      pipeline stages, starting from tape->next_stage.
3118  */
3119 static void idetape_insert_pipeline_into_queue (ide_drive_t *drive)
3120 {
3121         idetape_tape_t *tape = drive->driver_data;
3122
3123         if (tape->next_stage == NULL)
3124                 return;
3125         if (!idetape_pipeline_active(tape)) {
3126                 set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
3127                 idetape_active_next_stage(drive);
3128                 (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
3129         }
3130 }
3131
3132 static void idetape_create_inquiry_cmd (idetape_pc_t *pc)
3133 {
3134         idetape_init_pc(pc);
3135         pc->c[0] = IDETAPE_INQUIRY_CMD;
3136         pc->c[4] = pc->request_transfer = 254;
3137         pc->callback = &idetape_pc_callback;
3138 }
3139
3140 static void idetape_create_rewind_cmd (ide_drive_t *drive, idetape_pc_t *pc)
3141 {
3142         idetape_init_pc(pc);
3143         pc->c[0] = IDETAPE_REWIND_CMD;
3144         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
3145         pc->callback = &idetape_pc_callback;
3146 }
3147
3148 #if 0
3149 static void idetape_create_mode_select_cmd (idetape_pc_t *pc, int length)
3150 {
3151         idetape_init_pc(pc);
3152         set_bit(PC_WRITING, &pc->flags);
3153         pc->c[0] = IDETAPE_MODE_SELECT_CMD;
3154         pc->c[1] = 0x10;
3155         put_unaligned(htons(length), (unsigned short *) &pc->c[3]);
3156         pc->request_transfer = 255;
3157         pc->callback = &idetape_pc_callback;
3158 }
3159 #endif
3160
3161 static void idetape_create_erase_cmd (idetape_pc_t *pc)
3162 {
3163         idetape_init_pc(pc);
3164         pc->c[0] = IDETAPE_ERASE_CMD;
3165         pc->c[1] = 1;
3166         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
3167         pc->callback = &idetape_pc_callback;
3168 }
3169
3170 static void idetape_create_space_cmd (idetape_pc_t *pc,int count, u8 cmd)
3171 {
3172         idetape_init_pc(pc);
3173         pc->c[0] = IDETAPE_SPACE_CMD;
3174         put_unaligned(htonl(count), (unsigned int *) &pc->c[1]);
3175         pc->c[1] = cmd;
3176         set_bit(PC_WAIT_FOR_DSC, &pc->flags);
3177         pc->callback = &idetape_pc_callback;
3178 }
3179
3180 static void idetape_wait_first_stage (ide_drive_t *drive)
3181 {
3182         idetape_tape_t *tape = drive->driver_data;
3183         unsigned long flags;
3184
3185         if (tape->first_stage == NULL)
3186                 return;
3187         spin_lock_irqsave(&tape->spinlock, flags);
3188         if (tape->active_stage == tape->first_stage)
3189                 idetape_wait_for_request(drive, tape->active_data_request);
3190         spin_unlock_irqrestore(&tape->spinlock, flags);
3191 }
3192
3193 /*
3194  *      idetape_add_chrdev_write_request tries to add a character device
3195  *      originated write request to our pipeline. In case we don't succeed,
3196  *      we revert to non-pipelined operation mode for this request.
3197  *
3198  *      1.      Try to allocate a new pipeline stage.
3199  *      2.      If we can't, wait for more and more requests to be serviced
3200  *              and try again each time.
3201  *      3.      If we still can't allocate a stage, fallback to
3202  *              non-pipelined operation mode for this request.
3203  */
3204 static int idetape_add_chrdev_write_request (ide_drive_t *drive, int blocks)
3205 {
3206         idetape_tape_t *tape = drive->driver_data;
3207         idetape_stage_t *new_stage;
3208         unsigned long flags;
3209         struct request *rq;
3210
3211 #if IDETAPE_DEBUG_LOG
3212         if (tape->debug_level >= 3)
3213                 printk(KERN_INFO "ide-tape: Reached idetape_add_chrdev_write_request\n");
3214 #endif /* IDETAPE_DEBUG_LOG */
3215
3216         /*
3217          *      Attempt to allocate a new stage.
3218          *      Pay special attention to possible race conditions.
3219          */
3220         while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) {
3221                 spin_lock_irqsave(&tape->spinlock, flags);
3222                 if (idetape_pipeline_active(tape)) {
3223                         idetape_wait_for_request(drive, tape->active_data_request);
3224                         spin_unlock_irqrestore(&tape->spinlock, flags);
3225                 } else {
3226                         spin_unlock_irqrestore(&tape->spinlock, flags);
3227                         idetape_insert_pipeline_into_queue(drive);
3228                         if (idetape_pipeline_active(tape))
3229                                 continue;
3230                         /*
3231                          *      Linux is short on memory. Fallback to
3232                          *      non-pipelined operation mode for this request.
3233                          */
3234                         return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
3235                 }
3236         }
3237         rq = &new_stage->rq;
3238         idetape_init_rq(rq, REQ_IDETAPE_WRITE);
3239         /* Doesn't actually matter - We always assume sequential access */
3240         rq->sector = tape->first_frame_position;
3241         rq->nr_sectors = rq->current_nr_sectors = blocks;
3242
3243         idetape_switch_buffers(tape, new_stage);
3244         idetape_add_stage_tail(drive, new_stage);
3245         tape->pipeline_head++;
3246 #if USE_IOTRACE
3247         IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
3248 #endif
3249         calculate_speeds(drive);
3250
3251         /*
3252          *      Estimate whether the tape has stopped writing by checking
3253          *      if our write pipeline is currently empty. If we are not
3254          *      writing anymore, wait for the pipeline to be full enough
3255          *      (90%) before starting to service requests, so that we will
3256          *      be able to keep up with the higher speeds of the tape.
3257          */
3258         if (!idetape_pipeline_active(tape)) {
3259                 if (tape->nr_stages >= tape->max_stages * 9 / 10 ||
3260                     tape->nr_stages >= tape->max_stages - tape->uncontrolled_pipeline_head_speed * 3 * 1024 / tape->tape_block_size) {
3261                         tape->measure_insert_time = 1;
3262                         tape->insert_time = jiffies;
3263                         tape->insert_size = 0;
3264                         tape->insert_speed = 0;
3265                         idetape_insert_pipeline_into_queue(drive);
3266                 }
3267         }
3268         if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
3269                 /* Return a deferred error */
3270                 return -EIO;
3271         return blocks;
3272 }
3273
3274 /*
3275  *      idetape_wait_for_pipeline will wait until all pending pipeline
3276  *      requests are serviced. Typically called on device close.
3277  */
3278 static void idetape_wait_for_pipeline (ide_drive_t *drive)
3279 {
3280         idetape_tape_t *tape = drive->driver_data;
3281         unsigned long flags;
3282
3283         while (tape->next_stage || idetape_pipeline_active(tape)) {
3284                 idetape_insert_pipeline_into_queue(drive);
3285                 spin_lock_irqsave(&tape->spinlock, flags);
3286                 if (idetape_pipeline_active(tape))
3287                         idetape_wait_for_request(drive, tape->active_data_request);
3288                 spin_unlock_irqrestore(&tape->spinlock, flags);
3289         }
3290 }
3291
3292 static void idetape_empty_write_pipeline (ide_drive_t *drive)
3293 {
3294         idetape_tape_t *tape = drive->driver_data;
3295         int blocks, min;
3296         struct idetape_bh *bh;
3297
3298 #if IDETAPE_DEBUG_BUGS
3299         if (tape->chrdev_direction != idetape_direction_write) {
3300                 printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline, but we are not writing.\n");
3301                 return;
3302         }
3303         if (tape->merge_stage_size > tape->stage_size) {
3304                 printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
3305                 tape->merge_stage_size = tape->stage_size;
3306         }
3307 #endif /* IDETAPE_DEBUG_BUGS */
3308         if (tape->merge_stage_size) {
3309                 blocks = tape->merge_stage_size / tape->tape_block_size;
3310                 if (tape->merge_stage_size % tape->tape_block_size) {
3311                         unsigned int i;
3312
3313                         blocks++;
3314                         i = tape->tape_block_size - tape->merge_stage_size % tape->tape_block_size;
3315                         bh = tape->bh->b_reqnext;
3316                         while (bh) {
3317                                 atomic_set(&bh->b_count, 0);
3318                                 bh = bh->b_reqnext;
3319                         }
3320                         bh = tape->bh;
3321                         while (i) {
3322                                 if (bh == NULL) {
3323
3324                                         printk(KERN_INFO "ide-tape: bug, bh NULL\n");
3325                                         break;
3326                                 }
3327                                 min = min(i, (unsigned int)(bh->b_size - atomic_read(&bh->b_count)));
3328                                 memset(bh->b_data + atomic_read(&bh->b_count), 0, min);
3329                                 atomic_add(min, &bh->b_count);
3330                                 i -= min;
3331                                 bh = bh->b_reqnext;
3332                         }
3333                 }
3334                 (void) idetape_add_chrdev_write_request(drive, blocks);
3335                 tape->merge_stage_size = 0;
3336         }
3337         idetape_wait_for_pipeline(drive);
3338         if (tape->merge_stage != NULL) {
3339                 __idetape_kfree_stage(tape->merge_stage);
3340                 tape->merge_stage = NULL;
3341         }
3342         clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
3343         tape->chrdev_direction = idetape_direction_none;
3344
3345         /*
3346          *      On the next backup, perform the feedback loop again.
3347          *      (I don't want to keep sense information between backups,
3348          *       as some systems are constantly on, and the system load
3349          *       can be totally different on the next backup).
3350          */
3351         tape->max_stages = tape->min_pipeline;
3352 #if IDETAPE_DEBUG_BUGS
3353         if (tape->first_stage != NULL ||
3354             tape->next_stage != NULL ||
3355             tape->last_stage != NULL ||
3356             tape->nr_stages != 0) {
3357                 printk(KERN_ERR "ide-tape: ide-tape pipeline bug, "
3358                         "first_stage %p, next_stage %p, "
3359                         "last_stage %p, nr_stages %d\n",
3360                         tape->first_stage, tape->next_stage,
3361                         tape->last_stage, tape->nr_stages);
3362         }
3363 #endif /* IDETAPE_DEBUG_BUGS */
3364 }
3365
3366 static void idetape_restart_speed_control (ide_drive_t *drive)
3367 {
3368         idetape_tape_t *tape = drive->driver_data;
3369
3370         tape->restart_speed_control_req = 0;
3371         tape->pipeline_head = 0;
3372         tape->controlled_last_pipeline_head = tape->uncontrolled_last_pipeline_head = 0;
3373         tape->controlled_previous_pipeline_head = tape->uncontrolled_previous_pipeline_head = 0;
3374         tape->pipeline_head_speed = tape->controlled_pipeline_head_speed = 5000;
3375         tape->uncontrolled_pipeline_head_speed = 0;
3376         tape->controlled_pipeline_head_time = tape->uncontrolled_pipeline_head_time = jiffies;
3377         tape->controlled_previous_head_time = tape->uncontrolled_previous_head_time = jiffies;
3378 }
3379
3380 static int idetape_initiate_read (ide_drive_t *drive, int max_stages)
3381 {
3382         idetape_tape_t *tape = drive->driver_data;
3383         idetape_stage_t *new_stage;
3384         struct request rq;
3385         int bytes_read;
3386         int blocks = tape->capabilities.ctl;
3387
3388         /* Initialize read operation */
3389         if (tape->chrdev_direction != idetape_direction_read) {
3390                 if (tape->chrdev_direction == idetape_direction_write) {
3391                         idetape_empty_write_pipeline(drive);
3392                         idetape_flush_tape_buffers(drive);
3393                 }
3394 #if IDETAPE_DEBUG_BUGS
3395                 if (tape->merge_stage || tape->merge_stage_size) {
3396                         printk (KERN_ERR "ide-tape: merge_stage_size should be 0 now\n");
3397                         tape->merge_stage_size = 0;
3398                 }
3399 #endif /* IDETAPE_DEBUG_BUGS */
3400                 if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
3401                         return -ENOMEM;
3402                 tape->chrdev_direction = idetape_direction_read;
3403
3404                 /*
3405                  *      Issue a read 0 command to ensure that DSC handshake
3406                  *      is switched from completion mode to buffer available
3407                  *      mode.
3408                  *      No point in issuing this if DSC overlap isn't supported,
3409                  *      some drives (Seagate STT3401A) will return an error.
3410                  */
3411                 if (drive->dsc_overlap) {
3412                         bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh);
3413                         if (bytes_read < 0) {
3414                                 __idetape_kfree_stage(tape->merge_stage);
3415                                 tape->merge_stage = NULL;
3416                                 tape->chrdev_direction = idetape_direction_none;
3417                                 return bytes_read;
3418                         }
3419                 }
3420         }
3421         if (tape->restart_speed_control_req)
3422                 idetape_restart_speed_control(drive);
3423         idetape_init_rq(&rq, REQ_IDETAPE_READ);
3424         rq.sector = tape->first_frame_position;
3425         rq.nr_sectors = rq.current_nr_sectors = blocks;
3426         if (!test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags) &&
3427             tape->nr_stages < max_stages) {
3428                 new_stage = idetape_kmalloc_stage(tape);
3429                 while (new_stage != NULL) {
3430                         new_stage->rq = rq;
3431                         idetape_add_stage_tail(drive, new_stage);
3432                         if (tape->nr_stages >= max_stages)
3433                                 break;
3434                         new_stage = idetape_kmalloc_stage(tape);
3435                 }
3436         }
3437         if (!idetape_pipeline_active(tape)) {
3438                 if (tape->nr_pending_stages >= 3 * max_stages / 4) {
3439                         tape->measure_insert_time = 1;
3440                         tape->insert_time = jiffies;
3441                         tape->insert_size = 0;
3442                         tape->insert_speed = 0;
3443                         idetape_insert_pipeline_into_queue(drive);
3444                 }
3445         }
3446         return 0;
3447 }
3448
3449 /*
3450  *      idetape_add_chrdev_read_request is called from idetape_chrdev_read
3451  *      to service a character device read request and add read-ahead
3452  *      requests to our pipeline.
3453  */
3454 static int idetape_add_chrdev_read_request (ide_drive_t *drive,int blocks)
3455 {
3456         idetape_tape_t *tape = drive->driver_data;
3457         unsigned long flags;
3458         struct request *rq_ptr;
3459         int bytes_read;
3460
3461 #if IDETAPE_DEBUG_LOG
3462         if (tape->debug_level >= 4)
3463                 printk(KERN_INFO "ide-tape: Reached idetape_add_chrdev_read_request, %d blocks\n", blocks);
3464 #endif /* IDETAPE_DEBUG_LOG */
3465
3466         /*
3467          * If we are at a filemark, return a read length of 0
3468          */
3469         if (test_bit(IDETAPE_FILEMARK, &tape->flags))
3470                 return 0;
3471
3472         /*
3473          * Wait for the next block to be available at the head
3474          * of the pipeline
3475          */
3476         idetape_initiate_read(drive, tape->max_stages);
3477         if (tape->first_stage == NULL) {
3478                 if (test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
3479                         return 0;
3480                 return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks, tape->merge_stage->bh);
3481         }
3482         idetape_wait_first_stage(drive);
3483         rq_ptr = &tape->first_stage->rq;
3484         bytes_read = tape->tape_block_size * (rq_ptr->nr_sectors - rq_ptr->current_nr_sectors);
3485         rq_ptr->nr_sectors = rq_ptr->current_nr_sectors = 0;
3486
3487
3488         if (rq_ptr->errors == IDETAPE_ERROR_EOD)
3489                 return 0;
3490         else {
3491                 idetape_switch_buffers(tape, tape->first_stage);
3492                 if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
3493                         set_bit(IDETAPE_FILEMARK, &tape->flags);
3494                 spin_lock_irqsave(&tape->spinlock, flags);
3495                 idetape_remove_stage_head(drive);
3496                 spin_unlock_irqrestore(&tape->spinlock, flags);
3497                 tape->pipeline_head++;
3498 #if USE_IOTRACE
3499                 IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
3500 #endif
3501                 calculate_speeds(drive);
3502         }
3503 #if IDETAPE_DEBUG_BUGS
3504         if (bytes_read > blocks * tape->tape_block_size) {
3505                 printk(KERN_ERR "ide-tape: bug: trying to return more bytes than requested\n");
3506                 bytes_read = blocks * tape->tape_block_size;
3507         }
3508 #endif /* IDETAPE_DEBUG_BUGS */
3509         return (bytes_read);
3510 }
3511
3512 static void idetape_pad_zeros (ide_drive_t *drive, int bcount)
3513 {
3514         idetape_tape_t *tape = drive->driver_data;
3515         struct idetape_bh *bh;
3516         int blocks;
3517
3518         while (bcount) {
3519                 unsigned int count;
3520
3521                 bh = tape->merge_stage->bh;
3522                 count = min(tape->stage_size, bcount);
3523                 bcount -= count;
3524                 blocks = count / tape->tape_block_size;
3525                 while (count) {
3526                         atomic_set(&bh->b_count, min(count, (unsigned int)bh->b_size));
3527                         memset(bh->b_data, 0, atomic_read(&bh->b_count));
3528                         count -= atomic_read(&bh->b_count);
3529                         bh = bh->b_reqnext;
3530                 }
3531                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
3532         }
3533 }
3534
3535 static int idetape_pipeline_size (ide_drive_t *drive)
3536 {
3537         idetape_tape_t *tape = drive->driver_data;
3538         idetape_stage_t *stage;
3539         struct request *rq;
3540         int size = 0;
3541
3542         idetape_wait_for_pipeline(drive);
3543         stage = tape->first_stage;
3544         while (stage != NULL) {
3545                 rq = &stage->rq;
3546                 size += tape->tape_block_size * (rq->nr_sectors-rq->current_nr_sectors);
3547                 if (rq->errors == IDETAPE_ERROR_FILEMARK)
3548                         size += tape->tape_block_size;
3549                 stage = stage->next;
3550         }
3551         size += tape->merge_stage_size;
3552         return size;
3553 }
3554
3555 /*
3556  *      Rewinds the tape to the Beginning Of the current Partition (BOP).
3557  *
3558  *      We currently support only one partition.
3559  */
3560 static int idetape_rewind_tape (ide_drive_t *drive)
3561 {
3562         int retval;
3563         idetape_pc_t pc;
3564 #if IDETAPE_DEBUG_LOG
3565         idetape_tape_t *tape = drive->driver_data;
3566         if (tape->debug_level >= 2)
3567                 printk(KERN_INFO "ide-tape: Reached idetape_rewind_tape\n");
3568 #endif /* IDETAPE_DEBUG_LOG */
3569
3570         idetape_create_rewind_cmd(drive, &pc);
3571         retval = idetape_queue_pc_tail(drive, &pc);
3572         if (retval)
3573                 return retval;
3574
3575         idetape_create_read_position_cmd(&pc);
3576         retval = idetape_queue_pc_tail(drive, &pc);
3577         if (retval)
3578                 return retval;
3579         return 0;
3580 }
3581
3582 /*
3583  *      Our special ide-tape ioctl's.
3584  *
3585  *      Currently there aren't any ioctl's.
3586  *      mtio.h compatible commands should be issued to the character device
3587  *      interface.
3588  */
3589 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, unsigned long arg)
3590 {
3591         idetape_tape_t *tape = drive->driver_data;
3592         idetape_config_t config;
3593         void __user *argp = (void __user *)arg;
3594
3595 #if IDETAPE_DEBUG_LOG
3596         if (tape->debug_level >= 4)
3597                 printk(KERN_INFO "ide-tape: Reached idetape_blkdev_ioctl\n");
3598 #endif /* IDETAPE_DEBUG_LOG */
3599         switch (cmd) {
3600                 case 0x0340:
3601                         if (copy_from_user(&config, argp, sizeof (idetape_config_t)))
3602                                 return -EFAULT;
3603                         tape->best_dsc_rw_frequency = config.dsc_rw_frequency;
3604                         tape->max_stages = config.nr_stages;
3605                         break;
3606                 case 0x0350:
3607                         config.dsc_rw_frequency = (int) tape->best_dsc_rw_frequency;
3608                         config.nr_stages = tape->max_stages;
3609                         if (copy_to_user(argp, &config, sizeof (idetape_config_t)))
3610                                 return -EFAULT;
3611                         break;
3612                 default:
3613                         return -EIO;
3614         }
3615         return 0;
3616 }
3617
3618 /*
3619  *      idetape_space_over_filemarks is now a bit more complicated than just
3620  *      passing the command to the tape since we may have crossed some
3621  *      filemarks during our pipelined read-ahead mode.
3622  *
3623  *      As a minor side effect, the pipeline enables us to support MTFSFM when
3624  *      the filemark is in our internal pipeline even if the tape doesn't
3625  *      support spacing over filemarks in the reverse direction.
3626  */
3627 static int idetape_space_over_filemarks (ide_drive_t *drive,short mt_op,int mt_count)
3628 {
3629         idetape_tape_t *tape = drive->driver_data;
3630         idetape_pc_t pc;
3631         unsigned long flags;
3632         int retval,count=0;
3633
3634         if (mt_count == 0)
3635                 return 0;
3636         if (MTBSF == mt_op || MTBSFM == mt_op) {
3637                 if (!tape->capabilities.sprev)
3638                         return -EIO;
3639                 mt_count = - mt_count;
3640         }
3641
3642         if (tape->chrdev_direction == idetape_direction_read) {
3643                 /*
3644                  *      We have a read-ahead buffer. Scan it for crossed
3645                  *      filemarks.
3646                  */
3647                 tape->merge_stage_size = 0;
3648                 if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
3649                         ++count;
3650                 while (tape->first_stage != NULL) {
3651                         if (count == mt_count) {
3652                                 if (mt_op == MTFSFM)
3653                                         set_bit(IDETAPE_FILEMARK, &tape->flags);
3654                                 return 0;
3655                         }
3656                         spin_lock_irqsave(&tape->spinlock, flags);
3657                         if (tape->first_stage == tape->active_stage) {
3658                                 /*
3659                                  *      We have reached the active stage in the read pipeline.
3660                                  *      There is no point in allowing the drive to continue
3661                                  *      reading any farther, so we stop the pipeline.
3662                                  *
3663                                  *      This section should be moved to a separate subroutine,
3664                                  *      because a similar function is performed in
3665                                  *      __idetape_discard_read_pipeline(), for example.
3666                                  */
3667                                 tape->next_stage = NULL;
3668                                 spin_unlock_irqrestore(&tape->spinlock, flags);
3669                                 idetape_wait_first_stage(drive);
3670                                 tape->next_stage = tape->first_stage->next;
3671                         } else
3672                                 spin_unlock_irqrestore(&tape->spinlock, flags);
3673                         if (tape->first_stage->rq.errors == IDETAPE_ERROR_FILEMARK)
3674                                 ++count;
3675                         idetape_remove_stage_head(drive);
3676                 }
3677                 idetape_discard_read_pipeline(drive, 0);
3678         }
3679
3680         /*
3681          *      The filemark was not found in our internal pipeline.
3682          *      Now we can issue the space command.
3683          */
3684         switch (mt_op) {
3685                 case MTFSF:
3686                 case MTBSF:
3687                         idetape_create_space_cmd(&pc,mt_count-count,IDETAPE_SPACE_OVER_FILEMARK);
3688                         return (idetape_queue_pc_tail(drive, &pc));
3689                 case MTFSFM:
3690                 case MTBSFM:
3691                         if (!tape->capabilities.sprev)
3692                                 return (-EIO);
3693                         retval = idetape_space_over_filemarks(drive, MTFSF, mt_count-count);
3694                         if (retval) return (retval);
3695                         count = (MTBSFM == mt_op ? 1 : -1);
3696                         return (idetape_space_over_filemarks(drive, MTFSF, count));
3697                 default:
3698                         printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",mt_op);
3699                         return (-EIO);
3700         }
3701 }
3702
3703
3704 /*
3705  *      Our character device read / write functions.
3706  *
3707  *      The tape is optimized to maximize throughput when it is transferring
3708  *      an integral number of the "continuous transfer limit", which is
3709  *      a parameter of the specific tape (26 KB on my particular tape).
3710  *      (32 kB for Onstream)
3711  *
3712  *      As of version 1.3 of the driver, the character device provides an
3713  *      abstract continuous view of the media - any mix of block sizes (even 1
3714  *      byte) on the same backup/restore procedure is supported. The driver
3715  *      will internally convert the requests to the recommended transfer unit,
3716  *      so that an unmatch between the user's block size to the recommended
3717  *      size will only result in a (slightly) increased driver overhead, but
3718  *      will no longer hit performance.
3719  *      This is not applicable to Onstream.
3720  */
3721 static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
3722                                     size_t count, loff_t *ppos)
3723 {
3724         struct ide_tape_obj *tape = ide_tape_f(file);
3725         ide_drive_t *drive = tape->drive;
3726         ssize_t bytes_read,temp, actually_read = 0, rc;
3727         ssize_t ret = 0;
3728
3729 #if IDETAPE_DEBUG_LOG
3730         if (tape->debug_level >= 3)
3731                 printk(KERN_INFO "ide-tape: Reached idetape_chrdev_read, count %Zd\n", count);
3732 #endif /* IDETAPE_DEBUG_LOG */
3733
3734         if (tape->chrdev_direction != idetape_direction_read) {
3735                 if (test_bit(IDETAPE_DETECT_BS, &tape->flags))
3736                         if (count > tape->tape_block_size &&
3737                             (count % tape->tape_block_size) == 0)
3738                                 tape->user_bs_factor = count / tape->tape_block_size;
3739         }
3740         if ((rc = idetape_initiate_read(drive, tape->max_stages)) < 0)
3741                 return rc;
3742         if (count == 0)
3743                 return (0);
3744         if (tape->merge_stage_size) {
3745                 actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count);
3746                 if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read))
3747                         ret = -EFAULT;
3748                 buf += actually_read;
3749                 tape->merge_stage_size -= actually_read;
3750                 count -= actually_read;
3751         }
3752         while (count >= tape->stage_size) {
3753                 bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl);
3754                 if (bytes_read <= 0)
3755                         goto finish;
3756                 if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read))
3757                         ret = -EFAULT;
3758                 buf += bytes_read;
3759                 count -= bytes_read;
3760                 actually_read += bytes_read;
3761         }
3762         if (count) {
3763                 bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl);
3764                 if (bytes_read <= 0)
3765                         goto finish;
3766                 temp = min((unsigned long)count, (unsigned long)bytes_read);
3767                 if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp))
3768                         ret = -EFAULT;
3769                 actually_read += temp;
3770                 tape->merge_stage_size = bytes_read-temp;
3771         }
3772 finish:
3773         if (!actually_read && test_bit(IDETAPE_FILEMARK, &tape->flags)) {
3774 #if IDETAPE_DEBUG_LOG
3775                 if (tape->debug_level >= 2)
3776                         printk(KERN_INFO "ide-tape: %s: spacing over filemark\n", tape->name);
3777 #endif
3778                 idetape_space_over_filemarks(drive, MTFSF, 1);
3779                 return 0;
3780         }
3781
3782         return (ret) ? ret : actually_read;
3783 }
3784
3785 static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
3786                                      size_t count, loff_t *ppos)
3787 {
3788         struct ide_tape_obj *tape = ide_tape_f(file);
3789         ide_drive_t *drive = tape->drive;
3790         ssize_t actually_written = 0;
3791         ssize_t ret = 0;
3792
3793         /* The drive is write protected. */
3794         if (tape->write_prot)
3795                 return -EACCES;
3796
3797 #if IDETAPE_DEBUG_LOG
3798         if (tape->debug_level >= 3)
3799                 printk(KERN_INFO "ide-tape: Reached idetape_chrdev_write, "
3800                         "count %Zd\n", count);
3801 #endif /* IDETAPE_DEBUG_LOG */
3802
3803         /* Initialize write operation */
3804         if (tape->chrdev_direction != idetape_direction_write) {
3805                 if (tape->chrdev_direction == idetape_direction_read)
3806                         idetape_discard_read_pipeline(drive, 1);
3807 #if IDETAPE_DEBUG_BUGS
3808                 if (tape->merge_stage || tape->merge_stage_size) {
3809                         printk(KERN_ERR "ide-tape: merge_stage_size "
3810                                 "should be 0 now\n");
3811                         tape->merge_stage_size = 0;
3812                 }
3813 #endif /* IDETAPE_DEBUG_BUGS */
3814                 if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
3815                         return -ENOMEM;
3816                 tape->chrdev_direction = idetape_direction_write;
3817                 idetape_init_merge_stage(tape);
3818
3819                 /*
3820                  *      Issue a write 0 command to ensure that DSC handshake
3821                  *      is switched from completion mode to buffer available
3822                  *      mode.
3823                  *      No point in issuing this if DSC overlap isn't supported,
3824                  *      some drives (Seagate STT3401A) will return an error.
3825                  */
3826                 if (drive->dsc_overlap) {
3827                         ssize_t retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
3828                         if (retval < 0) {
3829                                 __idetape_kfree_stage(tape->merge_stage);
3830                                 tape->merge_stage = NULL;
3831                                 tape->chrdev_direction = idetape_direction_none;
3832                                 return retval;
3833                         }
3834                 }
3835         }
3836         if (count == 0)
3837                 return (0);
3838         if (tape->restart_speed_control_req)
3839                 idetape_restart_speed_control(drive);
3840         if (tape->merge_stage_size) {
3841 #if IDETAPE_DEBUG_BUGS
3842                 if (tape->merge_stage_size >= tape->stage_size) {
3843                         printk(KERN_ERR "ide-tape: bug: merge buffer too big\n");
3844                         tape->merge_stage_size = 0;
3845                 }
3846 #endif /* IDETAPE_DEBUG_BUGS */
3847                 actually_written = min((unsigned int)(tape->stage_size - tape->merge_stage_size), (unsigned int)count);
3848                 if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written))
3849                                 ret = -EFAULT;
3850                 buf += actually_written;
3851                 tape->merge_stage_size += actually_written;
3852                 count -= actually_written;
3853
3854                 if (tape->merge_stage_size == tape->stage_size) {
3855                         ssize_t retval;
3856                         tape->merge_stage_size = 0;
3857                         retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
3858                         if (retval <= 0)
3859                                 return (retval);
3860                 }
3861         }
3862         while (count >= tape->stage_size) {
3863                 ssize_t retval;
3864                 if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size))
3865                         ret = -EFAULT;
3866                 buf += tape->stage_size;
3867                 count -= tape->stage_size;
3868                 retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
3869                 actually_written += tape->stage_size;
3870                 if (retval <= 0)
3871                         return (retval);
3872         }
3873         if (count) {
3874                 actually_written += count;
3875                 if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count))
3876                         ret = -EFAULT;
3877                 tape->merge_stage_size += count;
3878         }
3879         return (ret) ? ret : actually_written;
3880 }
3881
3882 static int idetape_write_filemark (ide_drive_t *drive)
3883 {
3884         idetape_pc_t pc;
3885
3886         /* Write a filemark */
3887         idetape_create_write_filemark_cmd(drive, &pc, 1);
3888         if (idetape_queue_pc_tail(drive, &pc)) {
3889                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
3890                 return -EIO;
3891         }
3892         return 0;
3893 }
3894
3895 /*
3896  *      idetape_mtioctop is called from idetape_chrdev_ioctl when
3897  *      the general mtio MTIOCTOP ioctl is requested.
3898  *
3899  *      We currently support the following mtio.h operations:
3900  *
3901  *      MTFSF   -       Space over mt_count filemarks in the positive direction.
3902  *                      The tape is positioned after the last spaced filemark.
3903  *
3904  *      MTFSFM  -       Same as MTFSF, but the tape is positioned before the
3905  *                      last filemark.
3906  *
3907  *      MTBSF   -       Steps background over mt_count filemarks, tape is
3908  *                      positioned before the last filemark.
3909  *
3910  *      MTBSFM  -       Like MTBSF, only tape is positioned after the last filemark.
3911  *
3912  *      Note:
3913  *
3914  *              MTBSF and MTBSFM are not supported when the tape doesn't
3915  *              support spacing over filemarks in the reverse direction.
3916  *              In this case, MTFSFM is also usually not supported (it is
3917  *              supported in the rare case in which we crossed the filemark
3918  *              during our read-ahead pipelined operation mode).
3919  *
3920  *      MTWEOF  -       Writes mt_count filemarks. Tape is positioned after
3921  *                      the last written filemark.
3922  *
3923  *      MTREW   -       Rewinds tape.
3924  *
3925  *      MTLOAD  -       Loads the tape.
3926  *
3927  *      MTOFFL  -       Puts the tape drive "Offline": Rewinds the tape and
3928  *      MTUNLOAD        prevents further access until the media is replaced.
3929  *
3930  *      MTNOP   -       Flushes tape buffers.
3931  *
3932  *      MTRETEN -       Retension media. This typically consists of one end
3933  *                      to end pass on the media.
3934  *
3935  *      MTEOM   -       Moves to the end of recorded data.
3936  *
3937  *      MTERASE -       Erases tape.
3938  *
3939  *      MTSETBLK -      Sets the user block size to mt_count bytes. If
3940  *                      mt_count is 0, we will attempt to autodetect
3941  *                      the block size.
3942  *
3943  *      MTSEEK  -       Positions the tape in a specific block number, where
3944  *                      each block is assumed to contain which user_block_size
3945  *                      bytes.
3946  *
3947  *      MTSETPART -     Switches to another tape partition.
3948  *
3949  *      MTLOCK -        Locks the tape door.
3950  *
3951  *      MTUNLOCK -      Unlocks the tape door.
3952  *
3953  *      The following commands are currently not supported:
3954  *
3955  *      MTFSS, MTBSS, MTWSM, MTSETDENSITY,
3956  *      MTSETDRVBUFFER, MT_ST_BOOLEANS, MT_ST_WRITE_THRESHOLD.
3957  */
3958 static int idetape_mtioctop (ide_drive_t *drive,short mt_op,int mt_count)
3959 {
3960         idetape_tape_t *tape = drive->driver_data;
3961         idetape_pc_t pc;
3962         int i,retval;
3963
3964 #if IDETAPE_DEBUG_LOG
3965         if (tape->debug_level >= 1)
3966                 printk(KERN_INFO "ide-tape: Handling MTIOCTOP ioctl: "
3967                         "mt_op=%d, mt_count=%d\n", mt_op, mt_count);
3968 #endif /* IDETAPE_DEBUG_LOG */
3969         /*
3970          *      Commands which need our pipelined read-ahead stages.
3971          */
3972         switch (mt_op) {
3973                 case MTFSF:
3974                 case MTFSFM:
3975                 case MTBSF:
3976                 case MTBSFM:
3977                         if (!mt_count)
3978                                 return (0);
3979                         return (idetape_space_over_filemarks(drive,mt_op,mt_count));
3980                 default:
3981                         break;
3982         }
3983         switch (mt_op) {
3984                 case MTWEOF:
3985                         if (tape->write_prot)
3986                                 return -EACCES;
3987                         idetape_discard_read_pipeline(drive, 1);
3988                         for (i = 0; i < mt_count; i++) {
3989                                 retval = idetape_write_filemark(drive);
3990                                 if (retval)
3991                                         return retval;
3992                         }
3993                         return (0);
3994                 case MTREW:
3995                         idetape_discard_read_pipeline(drive, 0);
3996                         if (idetape_rewind_tape(drive))
3997                                 return -EIO;
3998                         return 0;
3999                 case MTLOAD:
4000                         idetape_discard_read_pipeline(drive, 0);
4001                         idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
4002                         return (idetape_queue_pc_tail(drive, &pc));
4003                 case MTUNLOAD:
4004                 case MTOFFL:
4005                         /*
4006                          * If door is locked, attempt to unlock before
4007                          * attempting to eject.
4008                          */
4009                         if (tape->door_locked) {
4010                                 if (idetape_create_prevent_cmd(drive, &pc, 0))
4011                                         if (!idetape_queue_pc_tail(drive, &pc))
4012                                                 tape->door_locked = DOOR_UNLOCKED;
4013                         }
4014                         idetape_discard_read_pipeline(drive, 0);
4015                         idetape_create_load_unload_cmd(drive, &pc,!IDETAPE_LU_LOAD_MASK);
4016                         retval = idetape_queue_pc_tail(drive, &pc);
4017                         if (!retval)
4018                                 clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
4019                         return retval;
4020                 case MTNOP:
4021                         idetape_discard_read_pipeline(drive, 0);
4022                         return (idetape_flush_tape_buffers(drive));
4023                 case MTRETEN:
4024                         idetape_discard_read_pipeline(drive, 0);
4025                         idetape_create_load_unload_cmd(drive, &pc,IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
4026                         return (idetape_queue_pc_tail(drive, &pc));
4027                 case MTEOM:
4028                         idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
4029                         return (idetape_queue_pc_tail(drive, &pc));
4030                 case MTERASE:
4031                         (void) idetape_rewind_tape(drive);
4032                         idetape_create_erase_cmd(&pc);
4033                         return (idetape_queue_pc_tail(drive, &pc));
4034                 case MTSETBLK:
4035                         if (mt_count) {
4036                                 if (mt_count < tape->tape_block_size || mt_count % tape->tape_block_size)
4037                                         return -EIO;
4038                                 tape->user_bs_factor = mt_count / tape->tape_block_size;
4039                                 clear_bit(IDETAPE_DETECT_BS, &tape->flags);
4040                         } else
4041                                 set_bit(IDETAPE_DETECT_BS, &tape->flags);
4042                         return 0;
4043                 case MTSEEK:
4044                         idetape_discard_read_pipeline(drive, 0);
4045                         return idetape_position_tape(drive, mt_count * tape->user_bs_factor, tape->partition, 0);
4046                 case MTSETPART:
4047                         idetape_discard_read_pipeline(drive, 0);
4048                         return (idetape_position_tape(drive, 0, mt_count, 0));
4049                 case MTFSR:
4050                 case MTBSR:
4051                 case MTLOCK:
4052                         if (!idetape_create_prevent_cmd(drive, &pc, 1))
4053                                 return 0;
4054                         retval = idetape_queue_pc_tail(drive, &pc);
4055                         if (retval) return retval;
4056                         tape->door_locked = DOOR_EXPLICITLY_LOCKED;
4057                         return 0;
4058                 case MTUNLOCK:
4059                         if (!idetape_create_prevent_cmd(drive, &pc, 0))
4060                                 return 0;
4061                         retval = idetape_queue_pc_tail(drive, &pc);
4062                         if (retval) return retval;
4063                         tape->door_locked = DOOR_UNLOCKED;
4064                         return 0;
4065                 default:
4066                         printk(KERN_ERR "ide-tape: MTIO operation %d not "
4067                                 "supported\n", mt_op);
4068                         return (-EIO);
4069         }
4070 }
4071
4072 /*
4073  *      Our character device ioctls.
4074  *
4075  *      General mtio.h magnetic io commands are supported here, and not in
4076  *      the corresponding block interface.
4077  *
4078  *      The following ioctls are supported:
4079  *
4080  *      MTIOCTOP -      Refer to idetape_mtioctop for detailed description.
4081  *
4082  *      MTIOCGET -      The mt_dsreg field in the returned mtget structure
4083  *                      will be set to (user block size in bytes <<
4084  *                      MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK.
4085  *
4086  *                      The mt_blkno is set to the current user block number.
4087  *                      The other mtget fields are not supported.
4088  *
4089  *      MTIOCPOS -      The current tape "block position" is returned. We
4090  *                      assume that each block contains user_block_size
4091  *                      bytes.
4092  *
4093  *      Our own ide-tape ioctls are supported on both interfaces.
4094  */
4095 static int idetape_chrdev_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
4096 {
4097         struct ide_tape_obj *tape = ide_tape_f(file);
4098         ide_drive_t *drive = tape->drive;
4099         struct mtop mtop;
4100         struct mtget mtget;
4101         struct mtpos mtpos;
4102         int block_offset = 0, position = tape->first_frame_position;
4103         void __user *argp = (void __user *)arg;
4104
4105 #if IDETAPE_DEBUG_LOG
4106         if (tape->debug_level >= 3)
4107                 printk(KERN_INFO "ide-tape: Reached idetape_chrdev_ioctl, "
4108                         "cmd=%u\n", cmd);
4109 #endif /* IDETAPE_DEBUG_LOG */
4110
4111         tape->restart_speed_control_req = 1;
4112         if (tape->chrdev_direction == idetape_direction_write) {
4113                 idetape_empty_write_pipeline(drive);
4114                 idetape_flush_tape_buffers(drive);
4115         }
4116         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
4117                 block_offset = idetape_pipeline_size(drive) / (tape->tape_block_size * tape->user_bs_factor);
4118                 if ((position = idetape_read_position(drive)) < 0)
4119                         return -EIO;
4120         }
4121         switch (cmd) {
4122                 case MTIOCTOP:
4123                         if (copy_from_user(&mtop, argp, sizeof (struct mtop)))
4124                                 return -EFAULT;
4125                         return (idetape_mtioctop(drive,mtop.mt_op,mtop.mt_count));
4126                 case MTIOCGET:
4127                         memset(&mtget, 0, sizeof (struct mtget));
4128                         mtget.mt_type = MT_ISSCSI2;
4129                         mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
4130                         mtget.mt_dsreg = ((tape->tape_block_size * tape->user_bs_factor) << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
4131                         if (tape->drv_write_prot) {
4132                                 mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
4133                         }
4134                         if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
4135                                 return -EFAULT;
4136                         return 0;
4137                 case MTIOCPOS:
4138                         mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
4139                         if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
4140                                 return -EFAULT;
4141                         return 0;
4142                 default:
4143                         if (tape->chrdev_direction == idetape_direction_read)
4144                                 idetape_discard_read_pipeline(drive, 1);
4145                         return idetape_blkdev_ioctl(drive, cmd, arg);
4146         }
4147 }
4148
4149 static void idetape_get_blocksize_from_block_descriptor(ide_drive_t *drive);
4150
4151 /*
4152  *      Our character device open function.
4153  */
4154 static int idetape_chrdev_open (struct inode *inode, struct file *filp)
4155 {
4156         unsigned int minor = iminor(inode), i = minor & ~0xc0;
4157         ide_drive_t *drive;
4158         idetape_tape_t *tape;
4159         idetape_pc_t pc;
4160         int retval;
4161
4162         /*
4163          * We really want to do nonseekable_open(inode, filp); here, but some
4164          * versions of tar incorrectly call lseek on tapes and bail out if that
4165          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
4166          */
4167         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
4168
4169 #if IDETAPE_DEBUG_LOG
4170         printk(KERN_INFO "ide-tape: Reached idetape_chrdev_open\n");
4171 #endif /* IDETAPE_DEBUG_LOG */
4172
4173         if (i >= MAX_HWIFS * MAX_DRIVES)
4174                 return -ENXIO;
4175
4176         if (!(tape = ide_tape_chrdev_get(i)))
4177                 return -ENXIO;
4178
4179         drive = tape->drive;
4180
4181         filp->private_data = tape;
4182
4183         if (test_and_set_bit(IDETAPE_BUSY, &tape->flags)) {
4184                 retval = -EBUSY;
4185                 goto out_put_tape;
4186         }
4187
4188         retval = idetape_wait_ready(drive, 60 * HZ);
4189         if (retval) {
4190                 clear_bit(IDETAPE_BUSY, &tape->flags);
4191                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
4192                 goto out_put_tape;
4193         }
4194
4195         idetape_read_position(drive);
4196         if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags))
4197                 (void)idetape_rewind_tape(drive);
4198
4199         if (tape->chrdev_direction != idetape_direction_read)
4200                 clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
4201
4202         /* Read block size and write protect status from drive. */
4203         idetape_get_blocksize_from_block_descriptor(drive);
4204
4205         /* Set write protect flag if device is opened as read-only. */
4206         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
4207                 tape->write_prot = 1;
4208         else
4209                 tape->write_prot = tape->drv_write_prot;
4210
4211         /* Make sure drive isn't write protected if user wants to write. */
4212         if (tape->write_prot) {
4213                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
4214                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
4215                         clear_bit(IDETAPE_BUSY, &tape->flags);
4216                         retval = -EROFS;
4217                         goto out_put_tape;
4218                 }
4219         }
4220
4221         /*
4222          * Lock the tape drive door so user can't eject.
4223          */
4224         if (tape->chrdev_direction == idetape_direction_none) {
4225                 if (idetape_create_prevent_cmd(drive, &pc, 1)) {
4226                         if (!idetape_queue_pc_tail(drive, &pc)) {
4227                                 if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
4228                                         tape->door_locked = DOOR_LOCKED;
4229                         }
4230                 }
4231         }
4232         idetape_restart_speed_control(drive);
4233         tape->restart_speed_control_req = 0;
4234         return 0;
4235
4236 out_put_tape:
4237         ide_tape_put(tape);
4238         return retval;
4239 }
4240
4241 static void idetape_write_release (ide_drive_t *drive, unsigned int minor)
4242 {
4243         idetape_tape_t *tape = drive->driver_data;
4244
4245         idetape_empty_write_pipeline(drive);
4246         tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0);
4247         if (tape->merge_stage != NULL) {
4248                 idetape_pad_zeros(drive, tape->tape_block_size * (tape->user_bs_factor - 1));
4249                 __idetape_kfree_stage(tape->merge_stage);
4250                 tape->merge_stage = NULL;
4251         }
4252         idetape_write_filemark(drive);
4253         idetape_flush_tape_buffers(drive);
4254         idetape_flush_tape_buffers(drive);
4255 }
4256
4257 /*
4258  *      Our character device release function.
4259  */
4260 static int idetape_chrdev_release (struct inode *inode, struct file *filp)
4261 {
4262         struct ide_tape_obj *tape = ide_tape_f(filp);
4263         ide_drive_t *drive = tape->drive;
4264         idetape_pc_t pc;
4265         unsigned int minor = iminor(inode);
4266
4267         lock_kernel();
4268         tape = drive->driver_data;
4269 #if IDETAPE_DEBUG_LOG
4270         if (tape->debug_level >= 3)
4271                 printk(KERN_INFO "ide-tape: Reached idetape_chrdev_release\n");
4272 #endif /* IDETAPE_DEBUG_LOG */
4273
4274         if (tape->chrdev_direction == idetape_direction_write)
4275                 idetape_write_release(drive, minor);
4276         if (tape->chrdev_direction == idetape_direction_read) {
4277                 if (minor < 128)
4278                         idetape_discard_read_pipeline(drive, 1);
4279                 else
4280                         idetape_wait_for_pipeline(drive);
4281         }
4282         if (tape->cache_stage != NULL) {
4283                 __idetape_kfree_stage(tape->cache_stage);
4284                 tape->cache_stage = NULL;
4285         }
4286         if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags))
4287                 (void) idetape_rewind_tape(drive);
4288         if (tape->chrdev_direction == idetape_direction_none) {
4289                 if (tape->door_locked == DOOR_LOCKED) {
4290                         if (idetape_create_prevent_cmd(drive, &pc, 0)) {
4291                                 if (!idetape_queue_pc_tail(drive, &pc))
4292                                         tape->door_locked = DOOR_UNLOCKED;
4293                         }
4294                 }
4295         }
4296         clear_bit(IDETAPE_BUSY, &tape->flags);
4297         ide_tape_put(tape);
4298         unlock_kernel();
4299         return 0;
4300 }
4301
4302 /*
4303  *      idetape_identify_device is called to check the contents of the
4304  *      ATAPI IDENTIFY command results. We return:
4305  *
4306  *      1       If the tape can be supported by us, based on the information
4307  *              we have so far.
4308  *
4309  *      0       If this tape driver is not currently supported by us.
4310  */
4311 static int idetape_identify_device (ide_drive_t *drive)
4312 {
4313         struct idetape_id_gcw gcw;
4314         struct hd_driveid *id = drive->id;
4315 #if IDETAPE_DEBUG_INFO
4316         unsigned short mask,i;
4317 #endif /* IDETAPE_DEBUG_INFO */
4318
4319         if (drive->id_read == 0)
4320                 return 1;
4321
4322         *((unsigned short *) &gcw) = id->config;
4323
4324 #if IDETAPE_DEBUG_INFO
4325         printk(KERN_INFO "ide-tape: Dumping ATAPI Identify Device tape parameters\n");
4326         printk(KERN_INFO "ide-tape: Protocol Type: ");
4327         switch (gcw.protocol) {
4328                 case 0: case 1: printk("ATA\n");break;
4329                 case 2: printk("ATAPI\n");break;
4330                 case 3: printk("Reserved (Unknown to ide-tape)\n");break;
4331         }
4332         printk(KERN_INFO "ide-tape: Device Type: %x - ",gcw.device_type);
4333         switch (gcw.device_type) {
4334                 case 0: printk("Direct-access Device\n");break;
4335                 case 1: printk("Streaming Tape Device\n");break;
4336                 case 2: case 3: case 4: printk("Reserved\n");break;
4337                 case 5: printk("CD-ROM Device\n");break;
4338                 case 6: printk("Reserved\n");
4339                 case 7: printk("Optical memory Device\n");break;
4340                 case 0x1f: printk("Unknown or no Device type\n");break;
4341                 default: printk("Reserved\n");
4342         }
4343         printk(KERN_INFO "ide-tape: Removable: %s",gcw.removable ? "Yes\n":"No\n");
4344         printk(KERN_INFO "ide-tape: Command Packet DRQ Type: ");
4345         switch (gcw.drq_type) {
4346                 case 0: printk("Microprocessor DRQ\n");break;
4347                 case 1: printk("Interrupt DRQ\n");break;
4348                 case 2: printk("Accelerated DRQ\n");break;
4349                 case 3: printk("Reserved\n");break;
4350         }
4351         printk(KERN_INFO "ide-tape: Command Packet Size: ");
4352         switch (gcw.packet_size) {
4353                 case 0: printk("12 bytes\n");break;
4354                 case 1: printk("16 bytes\n");break;
4355                 default: printk("Reserved\n");break;
4356         }
4357         printk(KERN_INFO "ide-tape: Model: %.40s\n",id->model);
4358         printk(KERN_INFO "ide-tape: Firmware Revision: %.8s\n",id->fw_rev);
4359         printk(KERN_INFO "ide-tape: Serial Number: %.20s\n",id->serial_no);
4360         printk(KERN_INFO "ide-tape: Write buffer size: %d bytes\n",id->buf_size*512);
4361         printk(KERN_INFO "ide-tape: DMA: %s",id->capability & 0x01 ? "Yes\n":"No\n");
4362         printk(KERN_INFO "ide-tape: LBA: %s",id->capability & 0x02 ? "Yes\n":"No\n");
4363         printk(KERN_INFO "ide-tape: IORDY can be disabled: %s",id->capability & 0x04 ? "Yes\n":"No\n");
4364         printk(KERN_INFO "ide-tape: IORDY supported: %s",id->capability & 0x08 ? "Yes\n":"Unknown\n");
4365         printk(KERN_INFO "ide-tape: ATAPI overlap supported: %s",id->capability & 0x20 ? "Yes\n":"No\n");
4366         printk(KERN_INFO "ide-tape: PIO Cycle Timing Category: %d\n",id->tPIO);
4367         printk(KERN_INFO "ide-tape: DMA Cycle Timing Category: %d\n",id->tDMA);
4368         printk(KERN_INFO "ide-tape: Single Word DMA supported modes: ");
4369         for (i=0,mask=1;i<8;i++,mask=mask << 1) {
4370                 if (id->dma_1word & mask)
4371                         printk("%d ",i);
4372                 if (id->dma_1word & (mask << 8))
4373                         printk("(active) ");
4374         }
4375         printk("\n");
4376         printk(KERN_INFO "ide-tape: Multi Word DMA supported modes: ");
4377         for (i=0,mask=1;i<8;i++,mask=mask << 1) {
4378                 if (id->dma_mword & mask)
4379                         printk("%d ",i);
4380                 if (id->dma_mword & (mask << 8))
4381                         printk("(active) ");
4382         }
4383         printk("\n");
4384         if (id->field_valid & 0x0002) {
4385                 printk(KERN_INFO "ide-tape: Enhanced PIO Modes: %s\n",
4386                         id->eide_pio_modes & 1 ? "Mode 3":"None");
4387                 printk(KERN_INFO "ide-tape: Minimum Multi-word DMA cycle per word: ");
4388                 if (id->eide_dma_min == 0)
4389                         printk("Not supported\n");
4390                 else
4391                         printk("%d ns\n",id->eide_dma_min);
4392
4393                 printk(KERN_INFO "ide-tape: Manufacturer\'s Recommended Multi-word cycle: ");
4394                 if (id->eide_dma_time == 0)
4395                         printk("Not supported\n");
4396                 else
4397                         printk("%d ns\n",id->eide_dma_time);
4398
4399                 printk(KERN_INFO "ide-tape: Minimum PIO cycle without IORDY: ");
4400                 if (id->eide_pio == 0)
4401                         printk("Not supported\n");
4402                 else
4403                         printk("%d ns\n",id->eide_pio);
4404
4405                 printk(KERN_INFO "ide-tape: Minimum PIO cycle with IORDY: ");
4406                 if (id->eide_pio_iordy == 0)
4407                         printk("Not supported\n");
4408                 else
4409                         printk("%d ns\n",id->eide_pio_iordy);
4410
4411         } else
4412                 printk(KERN_INFO "ide-tape: According to the device, fields 64-70 are not valid.\n");
4413 #endif /* IDETAPE_DEBUG_INFO */
4414
4415         /* Check that we can support this device */
4416
4417         if (gcw.protocol !=2 )
4418                 printk(KERN_ERR "ide-tape: Protocol is not ATAPI\n");
4419         else if (gcw.device_type != 1)
4420                 printk(KERN_ERR "ide-tape: Device type is not set to tape\n");
4421         else if (!gcw.removable)
4422                 printk(KERN_ERR "ide-tape: The removable flag is not set\n");
4423         else if (gcw.packet_size != 0) {
4424                 printk(KERN_ERR "ide-tape: Packet size is not 12 bytes long\n");
4425                 if (gcw.packet_size == 1)
4426                         printk(KERN_ERR "ide-tape: Sorry, padding to 16 bytes is still not supported\n");
4427         } else
4428                 return 1;
4429         return 0;
4430 }
4431
4432 /*
4433  * Use INQUIRY to get the firmware revision
4434  */
4435 static void idetape_get_inquiry_results (ide_drive_t *drive)
4436 {
4437         char *r;
4438         idetape_tape_t *tape = drive->driver_data;
4439         idetape_pc_t pc;
4440         idetape_inquiry_result_t *inquiry;
4441
4442         idetape_create_inquiry_cmd(&pc);
4443         if (idetape_queue_pc_tail(drive, &pc)) {
4444                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n", tape->name);
4445                 return;
4446         }
4447         inquiry = (idetape_inquiry_result_t *) pc.buffer;
4448         memcpy(tape->vendor_id, inquiry->vendor_id, 8);
4449         memcpy(tape->product_id, inquiry->product_id, 16);
4450         memcpy(tape->firmware_revision, inquiry->revision_level, 4);
4451         ide_fixstring(tape->vendor_id, 10, 0);
4452         ide_fixstring(tape->product_id, 18, 0);
4453         ide_fixstring(tape->firmware_revision, 6, 0);
4454         r = tape->firmware_revision;
4455         if (*(r + 1) == '.')
4456                 tape->firmware_revision_num = (*r - '0') * 100 + (*(r + 2) - '0') * 10 + *(r + 3) - '0';
4457         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);
4458 }
4459
4460 /*
4461  *      idetape_get_mode_sense_results asks the tape about its various
4462  *      parameters. In particular, we will adjust our data transfer buffer
4463  *      size to the recommended value as returned by the tape.
4464  */
4465 static void idetape_get_mode_sense_results (ide_drive_t *drive)
4466 {
4467         idetape_tape_t *tape = drive->driver_data;
4468         idetape_pc_t pc;
4469         idetape_mode_parameter_header_t *header;
4470         idetape_capabilities_page_t *capabilities;
4471
4472         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
4473         if (idetape_queue_pc_tail(drive, &pc)) {
4474                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming some default values\n");
4475                 tape->tape_block_size = 512;
4476                 tape->capabilities.ctl = 52;
4477                 tape->capabilities.speed = 450;
4478                 tape->capabilities.buffer_size = 6 * 52;
4479                 return;
4480         }
4481         header = (idetape_mode_parameter_header_t *) pc.buffer;
4482         capabilities = (idetape_capabilities_page_t *) (pc.buffer + sizeof(idetape_mode_parameter_header_t) + header->bdl);
4483
4484         capabilities->max_speed = ntohs(capabilities->max_speed);
4485         capabilities->ctl = ntohs(capabilities->ctl);
4486         capabilities->speed = ntohs(capabilities->speed);
4487         capabilities->buffer_size = ntohs(capabilities->buffer_size);
4488
4489         if (!capabilities->speed) {
4490                 printk(KERN_INFO "ide-tape: %s: overriding capabilities->speed (assuming 650KB/sec)\n", drive->name);
4491                 capabilities->speed = 650;
4492         }
4493         if (!capabilities->max_speed) {
4494                 printk(KERN_INFO "ide-tape: %s: overriding capabilities->max_speed (assuming 650KB/sec)\n", drive->name);
4495                 capabilities->max_speed = 650;
4496         }
4497
4498         tape->capabilities = *capabilities;             /* Save us a copy */
4499         if (capabilities->blk512)
4500                 tape->tape_block_size = 512;
4501         else if (capabilities->blk1024)
4502                 tape->tape_block_size = 1024;
4503
4504 #if IDETAPE_DEBUG_INFO
4505         printk(KERN_INFO "ide-tape: Dumping the results of the MODE SENSE packet command\n");
4506         printk(KERN_INFO "ide-tape: Mode Parameter Header:\n");
4507         printk(KERN_INFO "ide-tape: Mode Data Length - %d\n",header->mode_data_length);
4508         printk(KERN_INFO "ide-tape: Medium Type - %d\n",header->medium_type);
4509         printk(KERN_INFO "ide-tape: Device Specific Parameter - %d\n",header->dsp);
4510         printk(KERN_INFO "ide-tape: Block Descriptor Length - %d\n",header->bdl);
4511
4512         printk(KERN_INFO "ide-tape: Capabilities and Mechanical Status Page:\n");
4513         printk(KERN_INFO "ide-tape: Page code - %d\n",capabilities->page_code);
4514         printk(KERN_INFO "ide-tape: Page length - %d\n",capabilities->page_length);
4515         printk(KERN_INFO "ide-tape: Read only - %s\n",capabilities->ro ? "Yes":"No");
4516         printk(KERN_INFO "ide-tape: Supports reverse space - %s\n",capabilities->sprev ? "Yes":"No");
4517         printk(KERN_INFO "ide-tape: Supports erase initiated formatting - %s\n",capabilities->efmt ? "Yes":"No");
4518         printk(KERN_INFO "ide-tape: Supports QFA two Partition format - %s\n",capabilities->qfa ? "Yes":"No");
4519         printk(KERN_INFO "ide-tape: Supports locking the medium - %s\n",capabilities->lock ? "Yes":"No");
4520         printk(KERN_INFO "ide-tape: The volume is currently locked - %s\n",capabilities->locked ? "Yes":"No");
4521         printk(KERN_INFO "ide-tape: The device defaults in the prevent state - %s\n",capabilities->prevent ? "Yes":"No");
4522         printk(KERN_INFO "ide-tape: Supports ejecting the medium - %s\n",capabilities->eject ? "Yes":"No");
4523         printk(KERN_INFO "ide-tape: Supports error correction - %s\n",capabilities->ecc ? "Yes":"No");
4524         printk(KERN_INFO "ide-tape: Supports data compression - %s\n",capabilities->cmprs ? "Yes":"No");
4525         printk(KERN_INFO "ide-tape: Supports 512 bytes block size - %s\n",capabilities->blk512 ? "Yes":"No");
4526         printk(KERN_INFO "ide-tape: Supports 1024 bytes block size - %s\n",capabilities->blk1024 ? "Yes":"No");
4527         printk(KERN_INFO "ide-tape: Supports 32768 bytes block size / Restricted byte count for PIO transfers - %s\n",capabilities->blk32768 ? "Yes":"No");
4528         printk(KERN_INFO "ide-tape: Maximum supported speed in KBps - %d\n",capabilities->max_speed);
4529         printk(KERN_INFO "ide-tape: Continuous transfer limits in blocks - %d\n",capabilities->ctl);
4530         printk(KERN_INFO "ide-tape: Current speed in KBps - %d\n",capabilities->speed);
4531         printk(KERN_INFO "ide-tape: Buffer size - %d\n",capabilities->buffer_size*512);
4532 #endif /* IDETAPE_DEBUG_INFO */
4533 }
4534
4535 /*
4536  *      ide_get_blocksize_from_block_descriptor does a mode sense page 0 with block descriptor
4537  *      and if it succeeds sets the tape block size with the reported value
4538  */
4539 static void idetape_get_blocksize_from_block_descriptor(ide_drive_t *drive)
4540 {
4541
4542         idetape_tape_t *tape = drive->driver_data;
4543         idetape_pc_t pc;
4544         idetape_mode_parameter_header_t *header;
4545         idetape_parameter_block_descriptor_t *block_descrp;
4546
4547         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
4548         if (idetape_queue_pc_tail(drive, &pc)) {
4549                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
4550                 if (tape->tape_block_size == 0) {
4551                         printk(KERN_WARNING "ide-tape: Cannot deal with zero block size, assume 32k\n");
4552                         tape->tape_block_size =  32768;
4553                 }
4554                 return;
4555         }
4556         header = (idetape_mode_parameter_header_t *) pc.buffer;
4557         block_descrp = (idetape_parameter_block_descriptor_t *) (pc.buffer + sizeof(idetape_mode_parameter_header_t));
4558         tape->tape_block_size =( block_descrp->length[0]<<16) + (block_descrp->length[1]<<8) + block_descrp->length[2];
4559         tape->drv_write_prot = (header->dsp & 0x80) >> 7;
4560
4561 #if IDETAPE_DEBUG_INFO
4562         printk(KERN_INFO "ide-tape: Adjusted block size - %d\n", tape->tape_block_size);
4563 #endif /* IDETAPE_DEBUG_INFO */
4564 }
4565 static void idetape_add_settings (ide_drive_t *drive)
4566 {
4567         idetape_tape_t *tape = drive->driver_data;
4568
4569 /*
4570  *                      drive   setting name    read/write      ioctl   ioctl           data type       min                     max                     mul_factor                      div_factor                      data pointer                            set function
4571  */
4572         ide_add_setting(drive,  "buffer",       SETTING_READ,   -1,     -1,             TYPE_SHORT,     0,                      0xffff,                 1,                              2,                              &tape->capabilities.buffer_size,        NULL);
4573         ide_add_setting(drive,  "pipeline_min", SETTING_RW,     -1,     -1,             TYPE_INT,       1,                      0xffff,                 tape->stage_size / 1024,        1,                              &tape->min_pipeline,                    NULL);
4574         ide_add_setting(drive,  "pipeline",     SETTING_RW,     -1,     -1,             TYPE_INT,       1,                      0xffff,                 tape->stage_size / 1024,        1,                              &tape->max_stages,                      NULL);
4575         ide_add_setting(drive,  "pipeline_max", SETTING_RW,     -1,     -1,             TYPE_INT,       1,                      0xffff,                 tape->stage_size / 1024,        1,                              &tape->max_pipeline,                    NULL);
4576         ide_add_setting(drive,  "pipeline_used",SETTING_READ,   -1,     -1,             TYPE_INT,       0,                      0xffff,                 tape->stage_size / 1024,        1,                              &tape->nr_stages,                       NULL);
4577         ide_add_setting(drive,  "pipeline_pending",SETTING_READ,-1,     -1,             TYPE_INT,       0,                      0xffff,                 tape->stage_size / 1024,        1,                              &tape->nr_pending_stages,               NULL);
4578         ide_add_setting(drive,  "speed",        SETTING_READ,   -1,     -1,             TYPE_SHORT,     0,                      0xffff,                 1,                              1,                              &tape->capabilities.speed,              NULL);
4579         ide_add_setting(drive,  "stage",        SETTING_READ,   -1,     -1,             TYPE_INT,       0,                      0xffff,                 1,                              1024,                           &tape->stage_size,                      NULL);
4580         ide_add_setting(drive,  "tdsc",         SETTING_RW,     -1,     -1,             TYPE_INT,       IDETAPE_DSC_RW_MIN,     IDETAPE_DSC_RW_MAX,     1000,                           HZ,                             &tape->best_dsc_rw_frequency,           NULL);
4581         ide_add_setting(drive,  "dsc_overlap",  SETTING_RW,     -1,     -1,             TYPE_BYTE,      0,                      1,                      1,                              1,                              &drive->dsc_overlap,                    NULL);
4582         ide_add_setting(drive,  "pipeline_head_speed_c",SETTING_READ,   -1,     -1,     TYPE_INT,       0,                      0xffff,                 1,                              1,                              &tape->controlled_pipeline_head_speed,  NULL);
4583         ide_add_setting(drive,  "pipeline_head_speed_u",SETTING_READ,   -1,     -1,     TYPE_INT,       0,                      0xffff,                 1,                              1,                              &tape->uncontrolled_pipeline_head_speed,        NULL);
4584         ide_add_setting(drive,  "avg_speed",    SETTING_READ,   -1,     -1,             TYPE_INT,       0,                      0xffff,                 1,                              1,                              &tape->avg_speed,               NULL);
4585         ide_add_setting(drive,  "debug_level",SETTING_RW,       -1,     -1,             TYPE_INT,       0,                      0xffff,                 1,                              1,                              &tape->debug_level,             NULL);
4586 }
4587
4588 /*
4589  *      ide_setup is called to:
4590  *
4591  *              1.      Initialize our various state variables.
4592  *              2.      Ask the tape for its capabilities.
4593  *              3.      Allocate a buffer which will be used for data
4594  *                      transfer. The buffer size is chosen based on
4595  *                      the recommendation which we received in step (2).
4596  *
4597  *      Note that at this point ide.c already assigned us an irq, so that
4598  *      we can queue requests here and wait for their completion.
4599  */
4600 static void idetape_setup (ide_drive_t *drive, idetape_tape_t *tape, int minor)
4601 {
4602         unsigned long t1, tmid, tn, t;
4603         int speed;
4604         struct idetape_id_gcw gcw;
4605         int stage_size;
4606         struct sysinfo si;
4607
4608         spin_lock_init(&tape->spinlock);
4609         drive->dsc_overlap = 1;
4610 #ifdef CONFIG_BLK_DEV_IDEPCI
4611         if (HWIF(drive)->pci_dev != NULL) {
4612                 /*
4613                  * These two ide-pci host adapters appear to need DSC overlap disabled.
4614                  * This probably needs further analysis.
4615                  */
4616                 if ((HWIF(drive)->pci_dev->device == PCI_DEVICE_ID_ARTOP_ATP850UF) ||
4617                     (HWIF(drive)->pci_dev->device == PCI_DEVICE_ID_TTI_HPT343)) {
4618                         printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n", tape->name);
4619                         drive->dsc_overlap = 0;
4620                 }
4621         }
4622 #endif /* CONFIG_BLK_DEV_IDEPCI */
4623         /* Seagate Travan drives do not support DSC overlap. */
4624         if (strstr(drive->id->model, "Seagate STT3401"))
4625                 drive->dsc_overlap = 0;
4626         tape->minor = minor;
4627         tape->name[0] = 'h';
4628         tape->name[1] = 't';
4629         tape->name[2] = '0' + minor;
4630         tape->chrdev_direction = idetape_direction_none;
4631         tape->pc = tape->pc_stack;
4632         tape->max_insert_speed = 10000;
4633         tape->speed_control = 1;
4634         *((unsigned short *) &gcw) = drive->id->config;
4635         if (gcw.drq_type == 1)
4636                 set_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags);
4637
4638         tape->min_pipeline = tape->max_pipeline = tape->max_stages = 10;
4639
4640         idetape_get_inquiry_results(drive);
4641         idetape_get_mode_sense_results(drive);
4642         idetape_get_blocksize_from_block_descriptor(drive);
4643         tape->user_bs_factor = 1;
4644         tape->stage_size = tape->capabilities.ctl * tape->tape_block_size;
4645         while (tape->stage_size > 0xffff) {
4646                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
4647                 tape->capabilities.ctl /= 2;
4648                 tape->stage_size = tape->capabilities.ctl * tape->tape_block_size;
4649         }
4650         stage_size = tape->stage_size;
4651         tape->pages_per_stage = stage_size / PAGE_SIZE;
4652         if (stage_size % PAGE_SIZE) {
4653                 tape->pages_per_stage++;
4654                 tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE;
4655         }
4656
4657         /*
4658          *      Select the "best" DSC read/write polling frequency
4659          *      and pipeline size.
4660          */
4661         speed = max(tape->capabilities.speed, tape->capabilities.max_speed);
4662
4663         tape->max_stages = speed * 1000 * 10 / tape->stage_size;
4664
4665         /*
4666          *      Limit memory use for pipeline to 10% of physical memory
4667          */
4668         si_meminfo(&si);
4669         if (tape->max_stages * tape->stage_size > si.totalram * si.mem_unit / 10)
4670                 tape->max_stages = si.totalram * si.mem_unit / (10 * tape->stage_size);
4671         tape->max_stages   = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES);
4672         tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES);
4673         tape->max_pipeline = min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES);
4674         if (tape->max_stages == 0)
4675                 tape->max_stages = tape->min_pipeline = tape->max_pipeline = 1;
4676
4677         t1 = (tape->stage_size * HZ) / (speed * 1000);
4678         tmid = (tape->capabilities.buffer_size * 32 * HZ) / (speed * 125);
4679         tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000);
4680
4681         if (tape->max_stages)
4682                 t = tn;
4683         else
4684                 t = t1;
4685
4686         /*
4687          *      Ensure that the number we got makes sense; limit
4688          *      it within IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
4689          */
4690         tape->best_dsc_rw_frequency = max_t(unsigned long, min_t(unsigned long, t, IDETAPE_DSC_RW_MAX), IDETAPE_DSC_RW_MIN);
4691         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
4692                 "%dkB pipeline, %lums tDSC%s\n",
4693                 drive->name, tape->name, tape->capabilities.speed,
4694                 (tape->capabilities.buffer_size * 512) / tape->stage_size,
4695                 tape->stage_size / 1024,
4696                 tape->max_stages * tape->stage_size / 1024,
4697                 tape->best_dsc_rw_frequency * 1000 / HZ,
4698                 drive->using_dma ? ", DMA":"");
4699
4700         idetape_add_settings(drive);
4701 }
4702
4703 static void ide_tape_remove(ide_drive_t *drive)
4704 {
4705         idetape_tape_t *tape = drive->driver_data;
4706
4707         ide_unregister_subdriver(drive, tape->driver);
4708
4709         ide_unregister_region(tape->disk);
4710
4711         ide_tape_put(tape);
4712 }
4713
4714 static void ide_tape_release(struct kref *kref)
4715 {
4716         struct ide_tape_obj *tape = to_ide_tape(kref);
4717         ide_drive_t *drive = tape->drive;
4718         struct gendisk *g = tape->disk;
4719
4720         BUG_ON(tape->first_stage != NULL || tape->merge_stage_size);
4721
4722         drive->dsc_overlap = 0;
4723         drive->driver_data = NULL;
4724         class_device_destroy(idetape_sysfs_class,
4725                         MKDEV(IDETAPE_MAJOR, tape->minor));
4726         class_device_destroy(idetape_sysfs_class,
4727                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
4728         idetape_devs[tape->minor] = NULL;
4729         g->private_data = NULL;
4730         put_disk(g);
4731         kfree(tape);
4732 }
4733
4734 #ifdef CONFIG_PROC_FS
4735
4736 static int proc_idetape_read_name
4737         (char *page, char **start, off_t off, int count, int *eof, void *data)
4738 {
4739         ide_drive_t     *drive = (ide_drive_t *) data;
4740         idetape_tape_t  *tape = drive->driver_data;
4741         char            *out = page;
4742         int             len;
4743
4744         len = sprintf(out, "%s\n", tape->name);
4745         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
4746 }
4747
4748 static ide_proc_entry_t idetape_proc[] = {
4749         { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
4750         { "name",       S_IFREG|S_IRUGO,        proc_idetape_read_name, NULL },
4751         { NULL, 0, NULL, NULL }
4752 };
4753
4754 #else
4755
4756 #define idetape_proc    NULL
4757
4758 #endif
4759
4760 static int ide_tape_probe(ide_drive_t *);
4761
4762 static ide_driver_t idetape_driver = {
4763         .gen_driver = {
4764                 .owner          = THIS_MODULE,
4765                 .name           = "ide-tape",
4766                 .bus            = &ide_bus_type,
4767         },
4768         .probe                  = ide_tape_probe,
4769         .remove                 = ide_tape_remove,
4770         .version                = IDETAPE_VERSION,
4771         .media                  = ide_tape,
4772         .supports_dsc_overlap   = 1,
4773         .do_request             = idetape_do_request,
4774         .end_request            = idetape_end_request,
4775         .error                  = __ide_error,
4776         .abort                  = __ide_abort,
4777         .proc                   = idetape_proc,
4778 };
4779
4780 /*
4781  *      Our character device supporting functions, passed to register_chrdev.
4782  */
4783 static struct file_operations idetape_fops = {
4784         .owner          = THIS_MODULE,
4785         .read           = idetape_chrdev_read,
4786         .write          = idetape_chrdev_write,
4787         .ioctl          = idetape_chrdev_ioctl,
4788         .open           = idetape_chrdev_open,
4789         .release        = idetape_chrdev_release,
4790 };
4791
4792 static int idetape_open(struct inode *inode, struct file *filp)
4793 {
4794         struct gendisk *disk = inode->i_bdev->bd_disk;
4795         struct ide_tape_obj *tape;
4796         ide_drive_t *drive;
4797
4798         if (!(tape = ide_tape_get(disk)))
4799                 return -ENXIO;
4800
4801         drive = tape->drive;
4802
4803         drive->usage++;
4804
4805         return 0;
4806 }
4807
4808 static int idetape_release(struct inode *inode, struct file *filp)
4809 {
4810         struct gendisk *disk = inode->i_bdev->bd_disk;
4811         struct ide_tape_obj *tape = ide_tape_g(disk);
4812         ide_drive_t *drive = tape->drive;
4813
4814         drive->usage--;
4815
4816         ide_tape_put(tape);
4817
4818         return 0;
4819 }
4820
4821 static int idetape_ioctl(struct inode *inode, struct file *file,
4822                         unsigned int cmd, unsigned long arg)
4823 {
4824         struct block_device *bdev = inode->i_bdev;
4825         struct ide_tape_obj *tape = ide_tape_g(bdev->bd_disk);
4826         ide_drive_t *drive = tape->drive;
4827         int err = generic_ide_ioctl(drive, file, bdev, cmd, arg);
4828         if (err == -EINVAL)
4829                 err = idetape_blkdev_ioctl(drive, cmd, arg);
4830         return err;
4831 }
4832
4833 static struct block_device_operations idetape_block_ops = {
4834         .owner          = THIS_MODULE,
4835         .open           = idetape_open,
4836         .release        = idetape_release,
4837         .ioctl          = idetape_ioctl,
4838 };
4839
4840 static int ide_tape_probe(ide_drive_t *drive)
4841 {
4842         idetape_tape_t *tape;
4843         struct gendisk *g;
4844         int minor;
4845
4846         if (!strstr("ide-tape", drive->driver_req))
4847                 goto failed;
4848         if (!drive->present)
4849                 goto failed;
4850         if (drive->media != ide_tape)
4851                 goto failed;
4852         if (!idetape_identify_device (drive)) {
4853                 printk(KERN_ERR "ide-tape: %s: not supported by this version of ide-tape\n", drive->name);
4854                 goto failed;
4855         }
4856         if (drive->scsi) {
4857                 printk("ide-tape: passing drive %s to ide-scsi emulation.\n", drive->name);
4858                 goto failed;
4859         }
4860         if (strstr(drive->id->model, "OnStream DI-")) {
4861                 printk(KERN_WARNING "ide-tape: Use drive %s with ide-scsi emulation and osst.\n", drive->name);
4862                 printk(KERN_WARNING "ide-tape: OnStream support will be removed soon from ide-tape!\n");
4863         }
4864         tape = (idetape_tape_t *) kzalloc (sizeof (idetape_tape_t), GFP_KERNEL);
4865         if (tape == NULL) {
4866                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape structure\n", drive->name);
4867                 goto failed;
4868         }
4869
4870         g = alloc_disk(1 << PARTN_BITS);
4871         if (!g)
4872                 goto out_free_tape;
4873
4874         ide_init_disk(g, drive);
4875
4876         ide_register_subdriver(drive, &idetape_driver);
4877
4878         kref_init(&tape->kref);
4879
4880         tape->drive = drive;
4881         tape->driver = &idetape_driver;
4882         tape->disk = g;
4883
4884         g->private_data = &tape->driver;
4885
4886         drive->driver_data = tape;
4887
4888         mutex_lock(&idetape_ref_mutex);
4889         for (minor = 0; idetape_devs[minor]; minor++)
4890                 ;
4891         idetape_devs[minor] = tape;
4892         mutex_unlock(&idetape_ref_mutex);
4893
4894         idetape_setup(drive, tape, minor);
4895
4896         class_device_create(idetape_sysfs_class, NULL,
4897                         MKDEV(IDETAPE_MAJOR, minor), &drive->gendev, "%s", tape->name);
4898         class_device_create(idetape_sysfs_class, NULL,
4899                         MKDEV(IDETAPE_MAJOR, minor + 128), &drive->gendev, "n%s", tape->name);
4900
4901         g->fops = &idetape_block_ops;
4902         ide_register_region(g);
4903
4904         return 0;
4905
4906 out_free_tape:
4907         kfree(tape);
4908 failed:
4909         return -ENODEV;
4910 }
4911
4912 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
4913 MODULE_LICENSE("GPL");
4914
4915 static void __exit idetape_exit (void)
4916 {
4917         driver_unregister(&idetape_driver.gen_driver);
4918         class_destroy(idetape_sysfs_class);
4919         unregister_chrdev(IDETAPE_MAJOR, "ht");
4920 }
4921
4922 static int __init idetape_init(void)
4923 {
4924         int error = 1;
4925         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
4926         if (IS_ERR(idetape_sysfs_class)) {
4927                 idetape_sysfs_class = NULL;
4928                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
4929                 error = -EBUSY;
4930                 goto out;
4931         }
4932
4933         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
4934                 printk(KERN_ERR "ide-tape: Failed to register character device interface\n");
4935                 error = -EBUSY;
4936                 goto out_free_class;
4937         }
4938
4939         error = driver_register(&idetape_driver.gen_driver);
4940         if (error)
4941                 goto out_free_driver;
4942
4943         return 0;
4944
4945 out_free_driver:
4946         driver_unregister(&idetape_driver.gen_driver);
4947 out_free_class:
4948         class_destroy(idetape_sysfs_class);
4949 out:
4950         return error;
4951 }
4952
4953 MODULE_ALIAS("ide:*m-tape*");
4954 module_init(idetape_init);
4955 module_exit(idetape_exit);
4956 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);