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