Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

#### TSKBK

Prolog

Control Block Contents
TSKBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### TSKBK Prolog

     Name       : HCPTSKBK
     Description: Task Control Block
     DSECT      : TSKBK
     Function   : The TSKBK contains certain types of status
                  information for an active or suspended task.  At
                  present, the TSKBK is only used in a few selected
                  cases:  to record HCPSPIE traps, HCPSAC error exits,
                  claims for entries on the CP-use access list, and
                  the status of a CP task suspended to resolve a page,
                  segment, or region fault.
                  The dispatcher itself does not operate on TSKBKs.
                  In general, a task with state information in a TSKBK
                  is not permitted to lose control.  However, certain
                  losses of control -- those which "formally suspend"
                  the task -- are permitted.  The events which formally
                  suspend a task across losses of control are:
                  -- The HCPACCES ATTACH and DETACH services.
                  -- The handling of translation exceptions (region,
                  segment, and page faults) in DAT-on CP code.
                  In these special cases, the task state is preserved
                  and restored across the loss of control.  When a
                  task is formally suspended, a new TSKBK is allocated
                  and hung off the prefix page, so that it will be
                  available for use by the next task dispatched.  When
                  a task is formally resumed, its TSKBK replaces the
                  one currently hung off the prefix page, and the
                  latter is returned to free storage.
     Located by : PFXTSKBK points to the TSKBK for the currently
                  dispatched task, or one which is eligible
                  for use by the current task.
                  A routine which formally suspends its task must
                  preserve the TSKBK pointer for use on resumption.
     Created by : HCPMPSON when a processor is brought on-line.
                  HCPTKMSU when a task is formally suspended.
     Deleted by : HCPTKMRS when a task is formally resumed.
     Serialized : The TSKBK which is designated by PFXTSKBK is only
                  manipulated while running on the owning processor.
                  Any other TSKBK is owned by the single task which
                  holds its address (e.g., the task itself, about to
                  be suspended or resumed), and is inaccessible to
                  other tasks.

#### TSKBK Control Block Content

#### TSKBK DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      TSKBK          Task Control Block
         State of suspended task
         Short (32 bit) general purpose register values. Register values may be
         (but are not required to be) saved here across formal task suspension
         of ShortReg tasks. Register values are saved here during host interrupt
         processing for conditions which CP automatically resolves (region,
         segment, and page faults which occur while CP is running in AR mode) or
         which can be trapped via HCPSPIE, if the faulting task is ShortReg. If
         the task (suspended or faulting) is LongReg, TSKGGR* definition below
         is used instead.
         If the TSKGR* ShortReg register layout is used, TSKLONGR must be set to
         0 to indicate ShortReg layout.
    0000    0 Bitstring   64 TSKGRS (0)     General registers
    0000    0 Signed       4 TSKGR0         ..
    0004    4 Signed       4 TSKGR1         ..
    0008    8 Signed       4 TSKGR2         ..
    000C   12 Signed       4 TSKGR3         ..
    0010   16 Signed       4 TSKGR4         ..
    0014   20 Signed       4 TSKGR5         ..
    0018   24 Signed       4 TSKGR6         ..
    001C   28 Signed       4 TSKGR7         ..
    0020   32 Signed       4 TSKGR8         ..
    0024   36 Signed       4 TSKGR9         ..
    0028   40 Signed       4 TSKGR10        ..
    002C   44 Signed       4 TSKGR11        ..
    0030   48 Signed       4 TSKGR12        ..
    0034   52 Signed       4 TSKGR13        ..
    0038   56 Signed       4 TSKGR14        ..
    003C   60 Signed       4 TSKGR15        ..
    0040   64 Bitstring   64 TSKARS (0)     Access registers
    0040   64 Signed       4 TSKAR0         ..
    0044   68 Signed       4 TSKAR1         ..
    0048   72 Signed       4 TSKAR2         ..
    004C   76 Signed       4 TSKAR3         ..
    0050   80 Signed       4 TSKAR4         ..
    0054   84 Signed       4 TSKAR5         ..
    0058   88 Signed       4 TSKAR6         ..
    005C   92 Signed       4 TSKAR7         ..
    0060   96 Signed       4 TSKAR8         ..
    0064  100 Signed       4 TSKAR9         ..
    0068  104 Signed       4 TSKAR10        ..
    006C  108 Signed       4 TSKAR11        ..
    0070  112 Signed       4 TSKAR12        ..
    0074  116 Signed       4 TSKAR13        ..
    0078  120 Signed       4 TSKAR14        ..
    007C  124 Signed       4 TSKAR15        ..
    0080  128 Dbl-Word     8 TSKPSW (0)     PSW of suspended task
    0080  128 Signed       4 TSKPSW0F
    0084  132 Signed       4 TSKPSW4F       Addr mode and instruction addr
         Resource ownership and related conditions
    0088  136 Signed       2 TSKCPDSP       Count of the number of address
                                            spaces owned by the dispatched
                                            configuration which have been
                                            attached by this task to the
                                            CP-use access list. When this
                                            count is non-zero, the
                                            purge-request timestamp of the
                                            dispatched user must be examined
                                            when resuming a suspended task.
    008A  138 Signed       2 TSKCPOTR       Count of the number of address
                                            spaces not owned by the
                                            dispatched configuration which
                                            have been attached to the CP-use
                                            access list.
    008C  140 Address      4 TSKRNUSR       Address of VMDBK of user that was
                                            dispatched when the task was
                                            suspended.
    0090  144 Bitstring    1 TSKFLAGS       Flags describing state of task
    0091  145 Bitstring    1 * (3)          Reserved for IBM use
    0094  148 Signed       4 TSKCR0SV       Preserved bits from host CR0
         HCPSPIE trap settings
    0098  152 Address      4 TSKSPIEA       Program-interruption exit address
    009C  156 Bitstring    4 TSKSPIEM       Program-interruption exit mask
    00A0  160 Dbl-Word     8 *              reserved for IBM use
         HCPSAC error exit routines
    00A8  168 Address      4 TSKEXPIR       Expired-internal-ASIT exit
    00AC  172 Address      4 TSKSTERR       Virtual-storage-error exit
    00B0  176 Address      4 TSKINVAD       Invalid-virtual-address exit
    00B4  180 Signed       4 *              reserved for IBM use
         Error event data: Details of a particular error condition, to be passed
         to an error exit routine (defined by HCPSPIE or HCPSAC).
    00B8  184 Bitstring    1 TSKEVENT       Type of event
              00000004       TSKEPROG       4 Program check in CP
              00000008       TSKEEXPI       8 AR-mode ref to space via CP-use
                                            ALE with expired i-ASIT
              0000000C       TSKEINVA       12 AR-mode ref to invalid address
                                            (not within space)
              00000010       TSKESTER       16 Paging or storage error on
                                            AR-mode reference
    00B9  185 Bitstring    3 *              reserved for IBM use
    00BC  188 Address      4 TSKEVNTA       Address of failing instruction
    00C0  192 Dbl-Word     8 TSKTGTIA       Target i-ASIT (for event types
                                            TSKEEXPI, -INVA, and -STER)
    00C8  200 Signed       4 TSKTGTAD       Host virtual address of target
                                            page (for event types TSKESTER
                                            and -INVA)
    00CC  204 Signed       4 TSKPRGCF (0)   Program Interruption Code fields
                                            (for event type TSKEPROG)
    00CC  204 Signed       2 TSKPRGIL       Program Interruption Instruction
                                            Length Code
    00CE  206 Signed       2 TSKPRGIN (0)   Program Interruption Code
                                            (halfwd)
    00CE  206 Bitstring    1 TSKPRGEE       Exception extension code
    00CF  207 Bitstring    1 TSKPRGIC       Program Interruption Code (low
                                            byte)
              00000119       PRGICROP       X'0119' Crypto Operation
                                            Exception
              00000136       PRGIADCP       X'0136' Addressing capability
              00008000       PRGIARPC       X'8000' ARITHMETIC PARTIAL
                                            COMPLETION BIT OF THE EXCEPTION
                                            EXTENSION CODE (BIT 0 OF THE
                                            PROGRAM CHECK INTERRUPT CODE)
    00D0  208 Dbl-Word     8 *              reserved for IBM use
         Scratch area for suspended tasks: This area may be used by the routine
         which requests formal suspension of the task, to preserve task status.
    00D8  216 Bitstring   64 TSKWORKA       Work area
              00000118       TSKLEN         *-TSKBK Length in bytes of a
                                            TSKBK
              00000023       TSKSIZE        (TSKLEN+7)/8 Size in doublewords
                                            of a TSKBK

#### TSKBK Storage Layout

    *** TSKBK - Task Control Block
    *
    *     +---------------------------+---------------------------+
    *   0 |          TSKGR0           |          TSKGR1           |
    *     +---------------------------+---------------------------+
    *   8 |          TSKGR2           |          TSKGR3           |
    *     +---------------------------+---------------------------+
    *  10 |          TSKGR4           |          TSKGR5           |
    *     +---------------------------+---------------------------+
    *  18 |          TSKGR6           |          TSKGR7           |
    *     +---------------------------+---------------------------+
    *  20 |          TSKGR8           |          TSKGR9           |
    *     +---------------------------+---------------------------+
    *  28 |         TSKGR10           |         TSKGR11           |
    *     +---------------------------+---------------------------+
    *  30 |         TSKGR12           |         TSKGR13           |
    *     +---------------------------+---------------------------+
    *  38 |         TSKGR14           |         TSKGR15           |
    *     +---------------------------+---------------------------+
    *  40 |          TSKAR0           |          TSKAR1           |
    *     +---------------------------+---------------------------+
    *  48 |          TSKAR2           |          TSKAR3           |
    *     +---------------------------+---------------------------+
    *  50 |          TSKAR4           |          TSKAR5           |
    *     +---------------------------+---------------------------+
    *  58 |          TSKAR6           |          TSKAR7           |
    *     +---------------------------+---------------------------+
    *  60 |          TSKAR8           |          TSKAR9           |
    *     +---------------------------+---------------------------+
    *  68 |         TSKAR10           |         TSKAR11           |
    *     +---------------------------+---------------------------+
    *  70 |         TSKAR12           |         TSKAR13           |
    *     +---------------------------+---------------------------+
    *  78 |         TSKAR14           |         TSKAR15           |
    *     +---------------------------+---------------------------+
    *  80 |         TSKPSW0F          |         TSKPSW4F          |
    *     +-------------+-------------+---------------------------+
    *  88 |  TSKCPDSP   |  TSKCPOTR   |         TSKRNUSR          |
    *     +------+------+-------------+---------------------------+
    *  90 |:FLAGS|////////////////////|         TSKCR0SV          |
    *     +------+--------------------+---------------------------+
    *  98 |         TSKSPIEA          |         TSKSPIEM          |
    *     +---------------------------+---------------------------+
    *  A0 |///////////////////////////////////////////////////////|
    *     +---------------------------+---------------------------+
    *  A8 |         TSKEXPIR          |         TSKSTERR          |
    *     +---------------------------+---------------------------+
    *  B0 |         TSKINVAD          |///////////////////////////|
    *     +------+--------------------+---------------------------+
    *  B8 |:EVENT|////////////////////|         TSKEVNTA          |
    *     +------+--------------------+---------------------------+
    *  C0 |                       TSKTGTIA                        |
    *     +---------------------------+-------------+------+------+
    *  C8 |         TSKTGTAD          |  TSKPRGIL   |:PRGEE|:PRGIC|
    *     +---------------------------+-------------+------+------+
    *  D0 |///////////////////////////////////////////////////////|
    *     +-------------------------------------------------------+
    *  D8 |                                                       |
    *     =                       TSKWORKA                        =
    *     |                                                       |
    *     +-------------------------------------------------------+
    * 118
    *
    *** TSKBK - Task Control Block

#### TSKBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    PRGIADCP       00CF 00000136
    PRGIARPC       00CF 00008000
    PRGICROP       00CF 00000119
    TSKARS         0040
    TSKAR0         0040
    TSKAR1         0044
    TSKAR10        0068
    TSKAR11        006C
    TSKAR12        0070
    TSKAR13        0074
    TSKAR14        0078
    TSKAR15        007C
    TSKAR2         0048
    TSKAR3         004C
    TSKAR4         0050
    TSKAR5         0054
    TSKAR6         0058
    TSKAR7         005C
    TSKAR8         0060
    TSKAR9         0064
    TSKCPDSP       0088
    TSKCPOTR       008A
    TSKCR0SV       0094
    TSKEEXPI       00B8 00000008
    TSKEINVA       00B8 0000000C
    TSKEPROG       00B8 00000004
    TSKESTER       00B8 00000010
    TSKEVENT       00B8
    TSKEVNTA       00BC
    TSKEXPIR       00A8
    TSKFLAGS       0090
    TSKGRS         0000
    TSKGR0         0000
    TSKGR1         0004
    TSKGR10        0028
    TSKGR11        002C
    TSKGR12        0030
    TSKGR13        0034
    TSKGR14        0038
    TSKGR15        003C
    TSKGR2         0008
    TSKGR3         000C
    TSKGR4         0010
    TSKGR5         0014
    TSKGR6         0018
    TSKGR7         001C
    TSKGR8         0020
    TSKGR9         0024
    TSKINVAD       00B0
    TSKLEN         00D8 00000118
    TSKPRGCF       00CC
    TSKPRGEE       00CE
    TSKPRGIC       00CF
    TSKPRGIL       00CC
    TSKPRGIN       00CE
    TSKPSW         0080
    TSKPSW0F       0080
    TSKPSW4F       0084
    TSKRNUSR       008C
    TSKSIZE        00D8 00000023
    TSKSPIEA       0098
    TSKSPIEM       009C
    TSKSTERR       00AC
    TSKTGTAD       00C8
    TSKTGTIA       00C0
    TSKWORKA       00D8

This information is based on z/VM V4R3.0. Last updated on 30 Apr 2002 at 18:15:16 EDT.
Copyright IBM Corporation, 1990, 2002